Standardization of work performed on CNC machines. What is the process of standardizing adjustment work on CNC machines? Standardization of machining on CNC machines
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CENTRAL BUREAU OF LABOR STANDARDS OF THE USSR STATE COMMITTEE FOR LABOR AND SOCIAL ISSUES
GENERAL ENGINEERING STANDARDS FOR TIME AND CUTTING MODES for standardizing work performed on universal and multi-purpose machines with numerical control
TIME STANDARDS
MOSCOW ECONOMY 1990
Standards for cutting times and modes were approved by Decree of the USSR State Committee on Labor and Social Issues and the Secretariat of the All-Union Central Council of Trade Unions dated February 3, 1988 N9 54/3-72 and recommended for use at machine-building enterprises.
Validity of the standards until 1994.
With the introduction of this collection, the General Machine-Building Standards for time and cutting modes for work performed on metal-cutting machines with program control (MGNII Labor, 1980) are cancelled.
Standards for time and cutting modes (4.1 and L) were developed by the Central Bureau of Labor Standards, Chelyabinsk Polytechnic Institute named after. Lenin Komsomol, Ryazan and Minsk branches of the Orgstakkinprom Institute with the participation of regulatory research organizations and mechanical engineering enterprises.
The first part contains standards for auxiliary time for installation and removal of parts associated with the operation; for control measurements; for workplace maintenance; breaks for rest and personal needs; time standards for setting up equipment; to adjust the tool outside the machine; methodology for calculating service standards, time and production standards for multi-machine maintenance.
The second part contains standards for cutting modes and all data on calculating the main time and machine-auxiliary time, i.e. to calculate the cycle time of automatic operation of the machine according to the program.
Time standards and cutting modes have been developed to calculate time standards for work performed on the most common types of universal and multi-purpose computer numerical control (CNC) equipment used in mechanical engineering in medium-scale and small-scale production.
Standards for time and cutting modes cover the work of machine tool setters and manipulators with program control, operators of machine tools with program control, and toolmakers.
The publication is intended for standardization specialists and technologists, as well as other engineering and technical workers involved in the development of control programs and the calculation of technically sound standards for maintenance, time and output for CNC machines.
At the end of the collection there is a review form, which is filled out by the organization and sent to CENT. 109028, Moscow, st. Solyanka, 3, building 3.
The provision of intersectoral normative and methodological materials on labor is carried out at the request of enterprises and organizations through the local bookselling network. Information about these publications is published in the Annotated thematic plans for the publication of literature of the Economics publishing house and Book Trade Bulletins.
011(01) -90 ISBN 5 - 282 - 00697 - 9
KB - 32 - 76 - 89
© Central Bureau of Labor Standards of the USSR State Committee for Labor and Social Issues (CBNT), 1990
The piece time for assembly, adjustment and disassembly of the kit ipprumepm n.i d>* teleoperation is determined by the formula
^"Un* = S^shlr1 G ^"|i pr 2 * ^N1I|zh)* (1*1 M
where T shlzh - piece time for assembly, adjustment and disassembly of a set of tools for a detail operation, min; n - number of customizable ingtrumsn mu per distal operation, pcs.; T t ... T sh>fa - piece time for assembly, adjustment and handling of different types of tools included in the kit, min.
1.8. Tariffication of work should be carried out according to the Unified Tariff and Qualification Directory of Work and Professions of Workers (issue 2, approved by the Decree of the USSR State Committee on Labor and Social Issues and the All-Russian Central Council of Trade Unions of January 16, 1985 No. 17/2-541, taking into account subsequent additions and changes to it The discrepancy between the worker’s qualifications and the established level of work cannot serve as a basis for any changes in the time standards calculated according to the collection.
1.9. With the improvement of CNC machines and control systems, as well as in those cases, the cost in enterprises has already been achieved higher)! labor productivity with high-quality performance of work, reducing correction factors can be established to time standards.
In cases where the local time standards in force at enterprises are less than those calculated according to the standards, the current standards must be left unchanged.
1.10. Time standards are put into effect in the manner prescribed by the “Regulations on the organization of labor standardization in the national economy”, approved by Resolution of the USSR State Committee for Labor and Social Issues and the Presidium of the All-Union Central Council of Trade Unions dated June 19, 1986 No. 226/II-6.
L11. To explain the procedure for using time standards, examples of calculating preparatory-final time and piece time for setting up a tool are given below.
Examples of calculating time standards, cutting modes and the time of automatic operation of the machine according to the program are given in Part II of the collection in the relevant sections.
1.12. Examples of calculating standards for preparatory and final time and piece time for setting up a tool
1.12.1. Examples of calculating the norms of preparatory and final time
Initial data
1. The name of the operation is turning-turret.
2. Machine - CNC turret lathe.
3. Machine model - 1P426DFZ (diameter of the processed rod - 65 mm).
4. Model of the CNC device - "Electronics NTs-ZG, program carrier - memory.
5. Part name - amplifier piston.
6. Processed material - steel 45, weight - 0.5 kg.
7. The method of installing the part is in a collet chuck.
8. Labor organization conditions: centralized delivery of workpieces, tools, devices, documentation to the workplace and their delivery after processing a batch of parts; receiving instructions before starting to process the part. Group processing of parts is carried out (the collet chuck is not installed on the machine spindle).
The part processing program is compiled by a software engineer and entered into the memory of the CNC system by the lathe operator; the program contains 17 processed sizes.
9. Number of tools in setup - 5:
1. Cutter 2120-4007 T15K6 (groove).
2. Cutter 2102-0009 (through persistent).
3. Special cutter (groove).
4. Cutter 2130-0153 T15K6 (cutting).
5. Drill 2301-0028 (hole 010).
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Trial processing 6 The part is accurate (has surfaces with tolerances for diameters greater than the 11th qualifier, groove) for four tools and four measured Map 29, 8.8 according to the diameter of the surfaces (two outer surfaces: pos. 27, 0 50.3 MO and O 203 MO; one groove b = 6; ind. G; approx. single groove-undercut 0 30 parts 2, 3 |
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Map 29, 8.8+t
note 1
Total preparatory and final time for a batch of parts
1. The name of the operation is turning and rotary.
4. Device model CNC-N55-2, program carrier - punched tape.
5. Part name - flange. "l.
6. Processed material - ~ SCh20 cast iron, weight -1500 kg.
7. The method of installing the part is in four cams with boxes, each is secured with six bolts on the faceplate of the machine.
8. Working conditions: delivery of tools, devices, documentation, workpieces to the workplace and their delivery after finishing processing of a batch of parts is carried out by the operator (adjuster).
The tool on the device for setting outside the machine is not pre-set.
9. Number of tools in the setup - 4 (including one groove cutter, tools 1 and 2 - from the previous setup):
1. Cutter 2102-0031VK8 (through).
2. Cutter 2141-0059 VK8 (boring).
3. Cutter 2140-0048 VK8 (boring).
4. Cutter NZh212-5043 (groove).
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Trial* treatment The part is precise (has surfaces with tolerances for diameters greater than the 11th grade, a groove) boring of grooves - one tool, one groove (08ООН9Х07ОО) boring and turning of external and internal surfaces - three tools, three surfaces variable in diameter - 0 1150h9.0 800N9, Card 30, pos. 49, ind. a Card 30, pos. 5, inl. in, all Map 30, note 1 25,5 0,85 - 21,7 263 |
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I t o g o T
Total preparatory time for a batch of parts
T„-T i1 + T„ a + T yarv ^ 91.9
Initial data
1. Name of the operation - turning.
Z Machine - chuck lathe with CNC.
3. Machine model - 1P756DFZ (the largest diameter of the product installed above the bed is 630 mm).
4. CNC device model - 2S85, program carrier - punched tape, memory.
5. Part name - flange.
6. The material being processed is SCh25 cast iron, weight - 90 kg.
7. The method of installing the part is in a three-jaw chuck.
8. Labor organization conditions: delivery*/to the workplace of tools, fixtures, documentation, workpieces and their delivery after processing a batch of parts is carried out by the operator (adjuster). Group processing of parts is carried out (a jaw chuck is not installed on the machine spindle).
The part processing program is compiled by a software engineer and entered into the memory of the CNC system by the lathe operator. The program contains 20 processed sizes.
adjustments):
1. Cutter 2102-0005 (through persistent).
2. Cutter 2141-0604 (boring).
3. Cutter 2141-0611 (boring).
4. Cutter NZh 2126-5043 (groove).
5 Number of tools in setup - 4 (tools 1 and 2 - from previous
Map, police, index
Time, mii
*1.0
1 Organizational preparation
Map 21. to 1). 2,3,4, inl. P
tions and handing them over after processing a batch of parts; receiving instructions before starting to process parts; Tool assembly is carried out in a special tool setting area for CNC machines.
9. Number of tools in setup - 25 (four tools: 1.12, 24.25 - from the previous setup):
1. End mill 6221-106.005 (plane 800x800).
2. Semi-finish cutter (hole 0 259.0).
3. Finishing cutter (hole 0259DN9).
4. Semi-finish cutter (hole 0169.0).
5. Finishing cutter (hole 0169.5Н9).
6. Rough cutter (hole 0 89).
7. Semi-finish cutter (hole 0 89.5).
8. Finishing cutter (hole 0 90js6).
9. Rough cutter (hole 0 79).
10. Semi-finish cutter (hole 0 79.5).
1L Finishing cutter (hole 0 80js6).
12. Disc cutter 2215-0001VK8 (lowering 0 205).
13. Rough cutter (hole 0 99).
14. Semi-finish cutter (hole 0 99.5).
15. Finishing cutter (hole 0100js6).
16. Semi-finish cutter (undercut 0130).
17. Drill 23004)200 (hole 0 8.6).
18. Tap 26804Yu03 (thread K1/8").
19. Drill 2301-0046 (hole 014).
20. Drill 2301-0050 (hole 015).
21. Countersink 2320-2373 No. 1VK8 (hole 015.5).
22. Reamer 2363-0050Н9 (hole 015.95Н9).
23. Reamer 2363-00550Н7 (hole 016Н7).
24. Drill 2317-0006 (centering).
25. Drill 2301-0061 (chamfer).
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Hag, position, index |
Time, min |
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Organizational preparation Total T P11 |
Card 25, pos. 1,3,4, ind. b |
4,0 + 2,0 + 2,0 8,0 |
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Setting up the machine* devices, tools, software devices: | |||
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install the device and shine |
Card 25, pos. 13 | ||
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move the table, headstock and area convenient for adjustment |
Card 25, pos. 20 | ||
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set the initial operating modes of the machine (spindle speed) |
Card 25, pos. 21 | ||
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install tool blocks in the magazine and remove 21 tools |
Card 25, pos. 22 | ||
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install the software into the reading device and remove |
Map 25, x 24 | ||
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check the functionality of the reader and punched tape |
Map 25, x 25 | ||
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set the initial X and Y coordinates (adjust the zero position) along the cylindrical surface |
Map 25, x 29 | ||
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set the tool to the cutting length (Z axis for six tools: 1,7,12,16,24 and 25) |
Map 25, x 30 | ||
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Total T„ 2 | |||
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And |» O l O L F S II and s |
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B Trial offset work The part is accurate (has surfaces with tolerances for lmams* t *ry above the I-th quality, groove) for four tools and three measured by dipmsh ru K;irta 2.4, 8.9 surfaces - e>*2c0hl0,<3 200Е17и канавка b = 10 тч. 6, чпл г Total T p lb Ka r."2K, b.V + 1 ShShSh'Ch.<ииС 1.1 |
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Total preparation time^extreme time for a batch of parts
T "1 + T "2 + T arr.
Example 5 Initial data
1. Name of the operation - vertical milling.
2. Machine - vertical milling with CNC.
3. Machine model - 6Р13РФЗ (with table length -1600 mm).
4. CNC device model - NZZ-1M; program carrier - punched tape.
5. Part name - strip.
6. Processed material - steel 45, weight -10 kg.
7. The method of installing the part is in a reconfigurable universal assembly device (USF).
8. Labor organization conditions: centralized delivery of workpieces, tools, devices, documentation to the workplace and their delivery after processing a batch of parts; receiving instructions before starting to process parts.
9. Number of tools in setup - 6 (tools 1 and 5 - from the previous setup):
1. Drill 2317-003 (centering).
2. Drill 22-2 (hole 0
3. Special end mill (for groove b = 20).
4. Milling cutter 2234-0007 (for groove b = 8Н9).
5. Drill 6-1 (hole 0 6).
6. Countersink 2350-0106 VK6 (lowering 016).
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Trial processing Milling the groove L, AN9 and L groove * 634 Map 33, 192 |
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Total T about 60 _
Total preparation and closing time for a batch of parts
Toz 1 + T and # 2 + Tprobr
1.12.2. An example of calculating the unit time for setting up a tool
Initial data
1. Name of the operation - assembly, adjustment and disassembly of a set of tools necessary for processing parts on a drilling-milling-boring machine.
2. Name of the device - BV-2027, with digital display.
3. Characteristics of the machine - cone 7:24 No. 50.
4. Labor organization conditions: delivery of tools and technical documentation to the toolmaker’s workplace is carried out by service production workers, dismantling of used tools is carried out by a toolmaker.
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Piece time, mii | |||||
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Tool used |
Map, position, index |
kya us-groyku and gathering* ku |
for disassembly | ||
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Drill 0 83, drill chuck, sleeve |
type of connection - 1 |
2,64 ■ 0,45 - 1,19 | |||
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2 M10 marks, adjustable thread-cutting chuck, holder |
type of connection - 2 |
3,15 * 0,65 = 2,05 | |||
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3 Spade drill 0 32, mandrel, sleeve |
type of connection - 1 | ||||
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4 Cutter mandrel adjustable for Map 38, oblique fastening, cutting, holder type of connection - 3, 0 boring hole - 80 mm | |||||
2. MULTI-SITE SERVICE
2.1. To develop and improve the efficiency of multi-machine maintenance of machine tools with numerical control (CNC), the enterprise must create certain organizational and technical conditions that can significantly increase the productivity of operators and adjusters. Work on servicing CNC machines involves combining the functions of an operator and an adjuster.
2.2. The most economically feasible form of labor organization in areas of CNC machine tools is link (group). In the link (group) form, a certain service area is assigned to a link or group of workers included in the team.
The experience of enterprises testifies to the advantage of the link form of labor organization when servicing CNC machines, which ensures better use of working time and equipment.
The best division of labor when servicing workplaces of CNC machines is considered to be one in which the multi-machine operator and the setup operator have, in addition to the separated ones, some common functions. General functions include carrying out operational work, adjusting machines; The functions of setting up equipment are carried out by an adjuster. This division of labor has economic and social advantages. The ability to perform the same functions by two workers allows you to reduce equipment downtime due to the coincidence of the need to service several machines and improve the use of working time. At the same time, the mastery of adjustment functions by multi-machine operators increases the content of their work and creates opportunities for growth in qualifications.
2.3. To introduce multi-machine maintenance and rational use of working time, it is necessary to create a sufficient scope of work for each worker. Equipment and organizational supplies must be conveniently located and meet the requirements of the brigade form of labor organization. For this purpose, the design of the organization of workplaces for multi-machine operators is carried out in accordance with the diagrams presented in Section 3.5. Preference should be given to schemes that ensure full worker load with active work, the shortest length of transitions within the workplace and good visibility of all machines.
There are cyclic and non-cyclic maintenance of machines at a multi-machine workplace. During cyclic maintenance, the worker consistently performs auxiliary work techniques, moving from machine to machine. During non-cyclic maintenance, the worker approaches the machine on which automatic operation has ended, regardless of the location of the machines on the site.
2.4. Calculation of service standards
2.4.1. Service standards are set taking into account the normal level of employment - K yes. When working on CNC machines, taking into account heterogeneous technological operations with a changing range of manufactured parts, K l l - 0.75...0.85. When working on backup machines K A5 = 0.85. D95.
Z42. Calculation of the number of machines served by one worker, required to service the CNC equipment available on the site, and the number of units is carried out using the formulas:
a) when working on backup machines
П с = (-bs- + 1) К Л1; (21)
b) when working on machines that produce heterogeneous products,
"c = + 1) k, (2-2)
where is the cycle time of the automatic operation of the machine (machine-programmed time for processing a part, the operation of a manipulator or robot, not covered by the processing time of the part), min (according to formula 13); 2j - sum of processing time
rolls of parts (according to the program and operation of the manipulator or robot) at the workplace for the period of one cycle, min; T, is the time a worker is busy performing manual, machine-manual work, active monitoring of the progress of the technological process, etc., min; Jj T a - the sum of the worker’s employment time on all serviced machines for the period of one cycle, min; - normal level of employment.
The number of units is calculated using the formula
S - -b»-, (23)
where S is the number of units required to service the equipment available on site, people; Pu Ch - the number of CNC machines installed on the site; p s - the number of machines serviced by one worker.
T, - T, y + TYo, + T MM(+ T. + T n + T^, (2.4)
where T lu is the time for installing and removing the part manually or with a lift, min; Тіо„ - auxiliary time associated with the operation (not included in the control program), min; T i - time of active monitoring of the technological process, min; T p - time of transition of a multi-machine operator from one machine to another (during one cycle), min (given in Table 2.4); T m - auxiliary time for control measurements, min; - time for servicing the workplace, min.
2.43. The number of machines at multi-machine workplaces is determined on the basis of a comparative calculation of labor productivity and processing costs, especially when installing expensive equipment such as multi-purpose CNC machines.
The cost-effective number of machines serviced by a multi-machine operator can be determined by comparing the costs associated with the operation of a multi-machine operator and equipment when operating the machines and various options for the equipment being serviced.
When calculating the number of serviced machines corresponding to the lowest total costs of performing operations, take into account the costs of performing operations, the costs of materialized labor required to produce the same volume of products, which include depreciation costs, expenses for routine repairs and maintenance, electricity, through 0
ratio and employment coefficient K/. 3
1. GENERAL PART
1.1. Standards for time and cutting modes are intended for technical regulation of work performed on universal and multi-purpose machines. numerical program control in conditions of small-scale and medium-scale production types. One of the main characteristics of the type of production is the coefficient of consolidation of operations (K^), calculated by the formula
where O is the number of different operations; P is the number of jobs performing various operations.
The coefficient of consolidation of operations in accordance with GOST 3.1121-84 is taken equal to:
10 < К м £ 20 - для среднесерийного типа производства;
20 < 3 40 - для мелкосерийного типа производства.
The value of the operation consolidation coefficient is taken for a planning period equal to one month.
The collection is based on the medium-batch type of production. For small-scale production enterprises or for individual sections in a medium-scale production type operating in small-scale production conditions, correction factors for auxiliary time are applied.
1.2. When introducing a brigade (team, group) form of labor organization, standards can be used to calculate service standards, complex time standards, production and number standards.
13. The use of machine tools with numerical control is one of the main directions of automation of metal cutting, provides a significant economic effect and makes it possible to free up a large number of universal equipment, as well as improve the quality of products and working conditions of machine operators. The greatest economic effect from the introduction of numerical control machines is achieved when processing parts with a complex profile, which is associated with constantly changing cutting parameters (speed, feed direction, etc.).
The use of numerically controlled machines instead of universal equipment allows:
use multi-machine service and brigade (team, group) form of labor organization;
increase labor productivity by reducing auxiliary and machine processing time on the machine;
eliminate marking operations and interoperational control; thanks to abundant cooling and favorable conditions for chip formation, increase processing speed and eliminate the need for visual monitoring of markings;
automate auxiliary work techniques (approach and removal of a tool or part, setting a tool to size, changing a tool), use optimal tool trajectories;
Expenses* associated with one minute of work of the main worker-multi-machine operator based on the average percentage of compliance with standards, taking into account the accrual of wages, the cost of maintaining auxiliary and maintenance personnel -
Job category
w
2.4.4. Calculation of occupancy rate
t+t
still - operational time, min.
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Table 2.2 Cost of operating CNC machines for one minute |
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reduce the labor intensity of metalwork finishing due to obtaining high accuracy and lower roughness of curved sections of contours and surfaces of parts;
reduce the labor intensity of product assembly, which is due to the stability of the dimensions of parts (increased accuracy) and the elimination of fitting operations; reduce costs for design and manufacturing of equipment.
L4. The collection is developed in two parts. Part I contains standards for preparatory and final time, time for installing and removing parts, auxiliary time associated with the operation, for servicing the workplace, breaks for rest and personal needs, for control measurements, for setting up tools outside the machine; Part P contains standards for cutting conditions, allowing you to select the standard size of the tool, its geometric parameters, the brand of the cutting part of the tool, the required allowance, the number of feed strokes, cutting speeds, and the power required for cutting.
Standards for time and cutting conditions are given both in tabular and analytical form, thereby allowing the use of a computer when drawing up a program and calculating time standards that correspond to the lowest cost of the operation and the highest productivity of the machine while ensuring increased reliability of the tool. Operation of tools in the modes recommended by the standards is possible only if technological production discipline is observed (equipment, tools, workpieces, accessories must meet the required standards).
The time standards given in the collection are designed to standardize work when servicing one machine by a worker. When rationing multi-machine work, to calculate the time standard, it is necessary to use the guidelines and time standards for multi-machine work given in maps 17,18,19.
15. When developing standards for time and cutting modes, the following materials were used as initial data:
primary materials of production observations on labor organization, technology, time spent and cutting modes of mechanical engineering enterprises;
industry standards for time and cutting modes developed by GSPKTB "Orgariminstrument" (Moscow), Ryazan, Minsk and Novosibirsk branches of the Orgstankinprom Institute, the Center for the Scientific Organization of Labor of the Ministry of Heavy Machinery (Kramatorsk), etc.;
Determination of time standards for rest and personal needs. Intersectoral methodological recommendations (Moscow: Research Institute of Labor, 1982);
Development of multi-machine service and expansion of service areas in industry. Intersectoral methodological recommendations and scientifically based regulatory materials (Moscow: Research Institute of Labor, 1983);
General machine-building standards for auxiliary time, for servicing the workplace and preparatory and final time on metal-cutting machines. Small-scale and individual production (Moscow: Research Institute of Labor, 1982);
General machine-building standards for auxiliary time, for servicing the workplace and preparatory and final time for work performed on metal-cutting machines. Medium-scale and large-scale production (M.: Research Institute of Labor, 1984);
passport data of metal-cutting CNC and multi-purpose machines; technical literature.
1.6. Standard time and its components
1.6.1. The standard time for performing operations on CNC machines when working on one machine (H^ consists of the standard preparatory and final time (G in J and the standard piece time (T^)
a tta ^ a org a exc \
T D1 = Cr u . + T.-Kj(i +
where T n is the cycle time of automatic operation of the machine according to the program” min;
T.-T. + T., (13)
where T s is the main (technological) time for processing one part, min;
Т„ = £ (1.4)
where C is the length of the path traversed by a tool or part in the feed direction when processing a technological section (taking into account plunge-in and overtravel), mm; S* - minute feed in a given technological section, mm/min; T m - machine-auxiliary time according to the program (for supplying a part or tool from the starting points to the processing zones and removal; setting the tool to size, changing the tool, changing the value and direction of feed, time of technological pauses (stops), etc.), min. ;
t. = Т„ + + Т„„, (1.5)
ede T m - time to install and remove the part manually or with a lift, min; T w - auxiliary time associated with the operation (not included in the control program), min; T may - auxiliary non-overlapping time for measurements, min; K TV - correction factor for the time of performing manual auxiliary work, depending on the batch of parts being processed; a^, a^, a ex - time for technical and organizational maintenance of the workplace, for rest and personal needs during single-machine maintenance, % of operational time.
1.6.1.1. With a collective form of labor organization, complex standards of labor costs are calculated (N vrl, man-hour), which can be obtained by applying correction factors to the sum of operating standards calculated for the conditions of the individual form of labor organization. It is possible to use correction factors to the sum of individual components of the complex norm, reflecting the total value of time spent by categories of these costs.
Complex norm Determined by the formula
n,p,= £n.„-k*, (1.6)
where N (is the time standard for manufacturing the i-th part of the brigade kit, man-hours; i = 1,2,3,..., l - the number of parts included in the brigade kit;
N.R, = S n* (1.7)
more H Bpj - standard time for performing the jth operation, person-hour; j = 1, 2,3,..., w - the number of operations required to manufacture the j-th part; - coefficient
effect of team work (K^< 1).
The coefficient of the effect of team work (K^) takes into account the average increase in labor productivity expected during the transition from an individual to a team form of labor organization, which should be included in complex standards.
As a result of the redistribution of functions between team members, mutual assistance or interchangeability, the required time to complete the amount of work assigned to the team is reduced, therefore, the corresponding time standard should be reduced. This occurs due to a decrease
For more complete and detailed data, see Methodological recommendations for standardizing the work of workers in conditions of collective forms of its organization and stimulation. M.: Economics, 1987.
the values of individual components of the time standard: auxiliary time, time for servicing the workplace, regulated breaks, preparatory and final time, and also due to the overlap of individual components of the time standard with computer time (in the latter case, the value of each component of the time standard may remain unchanged).
In end-to-end teams, the labor intensity of manufacturing a team set can be reduced by eliminating individual elements of preparatory and final time and time for servicing the workplace when handing over a shift “on the fly.”
Team work effect coefficients (K^) are established: at the industry level;
at the enterprise level, if there are no industry coefficients or they do not fully reflect the specifics of the team organization of labor at a particular enterprise.
are introduced as a Standard for the entire industry for a certain period (at least 1 year).
In order to expand the possibility of using the teamwork effect coefficient, in addition to the general value of the coefficient, the values of each of its components are calculated.
The effect of team work can be achieved through the following components:
expansion of the combination of professions (K^; expansion of multi-station service (IQ; mutual assistance and interchangeability of team members (K); transfer of shifts "on the fly" in cross-cutting teams (K 4); redistribution of functions between team members (K 3), etc.
The total value is determined as the product of its components (for a given type of brigade), i.e.
K*-K, -K, -K, ...K, (1.8)
At the enterprise level, as a rule, general values of K^ are established, accepted during the period for which they are designed, but not less than a year, if production conditions do not change.
If the team, in addition to deal workers, includes time workers and engineering and technical workers, then the complex time standard (person-hours) cl "is the sum of the time standards of piece workers, time workers and engineering technical workers for the production of one brigade set, adjusted for the teamwork effect coefficient.
L6.2 Standards for auxiliary time for installation and removal of parts. The time standards for installing and removing parts are given by type of fixture, depending on the type of machine tool, and provide for the most common methods of installing, aligning and fastening parts in universal and special clamps and fixtures. The main factors influencing the installation and removal time of a part are the weight of the part, the method of installing and fastening the part, the nature and accuracy of the alignment. In addition to these factors, the size of the installation surface, the number of simultaneously installed parts, the number of clamps, etc. are taken into account.
The standard time for installing and removing a part involves performing the following work:
when installing and removing manually
take and install the part, align and secure; turn the machine on and off; unfasten, remove the part and place it in a container; clean the device from shavings, wipe the base surfaces with a napkin;
when installing and removing a part with an overhead crane
call the tap; rig the part; transport the part to the machine; install the part, rig the part, align and secure; turn the machine on and off; unpin part; call the tap; rig the part; remove from the machine and transport it to a storage location; strap the part, clean the fixture or table surface from shavings, wipe the base surfaces with a napkin.
When installing and removing a part with a lift at a machine (or group of machines), they perform the same work as when installing and removing a part with an overhead crane, with the exception of calling the crane.
When installed in special devices, auxiliary time is defined as the sum of time: for installation and removal of one part; for installation and removal of each subsequent part more than one in multi-place devices; to secure the part, taking into account the number of clamps; to clean the device from chips, to wipe the base surfaces with a napkin.
At enterprises, in addition to universal and special devices on CNC machines, robots, manipulators and satellite tables are also used to install and remove parts.
Due to the wide variety of types and technical characteristics of robots and manipulators, it is not possible to develop time standards for installing and removing parts with their help; Each enterprise needs to draw up maps for the use of robots. Appendix 15 is given as an example. For cases of working on multi-purpose machines using satellite tables, it is necessary to use map 20, which shows the satellite loading scheme and the time for changing satellites.
In some cases, when the program provides for a special technological pause for refastening a part, the standard time should be reduced by an amount covered by the automatic operation of the machine. The standards provide for the installation and removal of parts weighing up to 20 kg manually and over 20 kg using lifting mechanisms.
The time for manual installation of parts weighing over 20 kg is given in the standards for use in certain cases when processing in areas where there are no lifting vehicles. Manual installation of parts weighing over 15 kg is not allowed for men under 18 years of age or women.
It is taken into account that parts installed manually are located at a distance of 2 m from the machine, and parts installed by crane are up to 5 m.
1.6.3. Standards of auxiliary epeuienu associated with the operation. Auxiliary time associated with the operation is divided into:
auxiliary time associated with an operation that is not included during the cycle of automatic operation of the machine according to the program and provides for the following work:
turn the tape drive mechanism on and off; set the specified relative position of the part and the tool along the coordinates X, Y, 2 and, if necessary, make adjustments; open and close the cover of the tape drive mechanism, rewind, insert the tape into the reading device; check the arrival of a part or tool at a given point after processing; advance the punched paper tape to its original position; install the shield against splashing with emulsion and remove;
machine-auxiliary time associated with the transition, included in the program and related to the automatic auxiliary operation of the machine, providing for: supply of a part or tool from the starting point to the processing zone and removal; setting the tool to the processing size; automatic tool change; turning the feed on and off; idling when switching from processing one surface to another; technological breaks provided
when suddenly changing the feed direction, checking dimensions, inspecting the tool and reinstalling or re-fastening the part.
Machine-auxiliary time associated with the transition, included in the program for the listed techniques, is determined from the passport data of the machines or other regulatory documents, is included as constituent elements during the automatic operation of the machine and is not taken into account separately (see appendices 27-30, part II ).
1.6.4. Standards for auxiliary time for control measurements. The required dimensions of parts processed on numerically controlled machines are ensured by the design of the machine or cutting tool and the accuracy of their adjustment.
In this regard, the time for control measurements (after completion of work according to the program) should be included in the standard piece time only if it is provided for by the technological process and taking into account the necessary frequency of such measurements during the work process, and only in cases where it cannot be covered by the cycle time of the automatic operation of the machine according to the program.
1.6.5. Time standards for servicing a workplace. The time for servicing a workplace is given by type and size of equipment, taking into account single-machine and multi-machine maintenance as a percentage of operational time. Maintenance of the workplace involves performing the following work:
changing a tool (or a block with a tool) due to its dullness; adjustment and adjustment of the machine during operation (changing the tool correction value);
sweeping and periodic removal of chips during work (except for sweeping chips from the base surfaces of installation devices, the time for which is taken into account in the auxiliary time for installing and removing the part).
Organizational maintenance of the workplace includes work to care for the workplace (main and auxiliary equipment, technological and organizational equipment, containers), related to the work shift as a whole: inspection and testing of equipment during work;
laying out tools at the beginning and cleaning them up at the end of the shift (except for multi-purpose machines);
lubrication and cleaning of the machine during the shift;
receiving instructions from the foreman and foreman during the shift;
cleaning the machine and workplace at the end of the shift.
1.66. Time standards for rest and personal needs. Time for rest and personal needs for the conditions of servicing one machine by one worker is not separately allocated and is taken into account in the time for servicing the workplace.
For cases of multi-machine service, a map of the time of rest breaks and personal needs is provided, depending on the characteristics of the work and with recommendations for the content of rest.
1.6.7. Standards for preparatory and final time. The standards are designed for setting up CNC machines for processing parts using implemented control programs and do not include actions for additional programming directly at the workplace (except for machines equipped with operational program control systems).
The standard time for setting up a machine is presented as the time for preparatory and final work to process a batch of identical parts, regardless of the batch, and is determined by the formula
T p, = T pz1 + T pz2 + T prlbr, (1.9.
where T pz is the standard time for setting up and setting up the machine, min; T pz (- standard time for organizational preparation, min; T pe 2 - standard time for setting up sgaikg
devices, tools, software devices, min; - time limit for trial processing.
The time for preparatory and final work is set depending on the type and size of the equipment, as well as taking into account the features of the program control system and is divided into time for organizational preparation; for setting up the machine, devices, tools, software devices; for a test run according to the program or trial processing of a part.
The scope of work for organizational training is common for all CNC machines, regardless of their group and model. Time for organizational preparation includes:
receiving work orders, drawings, technological documentation, software, cutting, auxiliary and control tools, fixtures, workpieces before the start and handing them over after finishing processing a batch of parts at the workplace or in the tool storeroom;
familiarization with the work, drawing, technological documentation, inspection of the workpiece;
master's instructions.
In a brigade form of labor organization, when workpieces are transferred between shifts, organizational preparation takes into account only the time for familiarization with the work, drawing, technological documentation, inspection of workpieces and instructing the foreman.
The work for setting up a machine, tools and devices includes adjustment work methods, depending on the purpose of the machine and its design features:
installation and removal of fastening devices;
installation and removal of a block or individual cutting tools;
setting the initial operating modes of the machine;
installing the software into the reading device and removing it; zero position adjustment, etc.
The time for trial processing of parts on lathe machines (up to 630 mm) and turret groups includes the time spent processing the part according to the program (cycle time) plus auxiliary time for performing additional techniques related to measuring the part, calculating corrections, and entering correction values into the CNC system , and auxiliary time for techniques for controlling the machine and the CNC system.
The time for trial processing of parts on turning (over 630 mm) rotary, milling, boring groups, and other machines includes time spent on processing parts using the test chip method with cutting tools, end mills, plus auxiliary time for performing additional techniques related to measuring the part, calculation of correction values, introduction of correction values into the CNC system, and auxiliary time for techniques for controlling the machine and the CNC system.
1.7. Norms of piece time for dimensional adjustment of cutting tools outside the machine
1.7.1. Piece time standards are intended to standardize work on setting up cutting tools for CNC machines, which is carried out by toolmakers (to set up tools) outside the machine in a specially equipped room using special instruments.
Piece time standards are set depending on:
type of devices used;
type and size of the tool being adjusted;
number of customizable coordinates;
the nature of the setting (by actual size or at a given coordinate).
To set up tools at enterprises in the mechanical engineering and metalworking industries, the following devices are used:
for machines of the drilling-milling-boring group - optical with digital indication type BV-2027, without digital indication type BV-2015 and contact type devices;
for turning machines - optical with digital display type BV-2026, without digital display type BV-2010, BV-2012M and contact type devices.
Taking into account the peculiarities of the tool setting processes, time standards have been developed separately for machines of the drilling-milling-boring group and machines of the turning group.
The most advanced devices with digital display are taken as the basis, but taking into account the correction factors given in the maps for changed operating conditions, these standards are used when rationing work on devices without digital display (type BV-2015, BV-2010, BV-2012M, etc.) and contact type devices.
When setting up a tool without instruments (using universal measuring instruments), the time standards must be calculated according to the standards for contact-type devices.
Piece time standards for assembling and setting up cutting tools on imported devices with digital display must be calculated according to the time standards for domestically produced devices such as BV-2027 and BB-2026 with a coefficient of 0.85; for devices without digital display - but for devices gopa BV-2015 and BV-2010 with a coefficient of 0.9.
The regulatory materials in this section cover the most typical connections for the mechanical engineering and metalworking industries, standard/cutting and auxiliary tools and are presented in the form of enlarged piece-time standards.
When calculating the time standards for assembling and adjusting the snow profile cutting tool, take a multiplying factor of 1.2.
In addition to the time for the main work, assembling and setting up the tool, the piece time schedule includes additional time spent on organizational and technical maintenance of the workplace, preparatory and final time and time for rest and personal needs in the amount of 14% of operational time.
The advisability of including additional costs in the general time standard is due to the difficulty of separating them from the total time associated with preparing the workplace for setup, and the time of assembling and setting up the tool itself.
To determine the norms of piece time for disassembling a used tool, the cards for assembling and setting up tools contain correction factors calculated differentially for each type of work.
Piece time standards for individual methods of assembling and setting up tools that are not included in the complexes are reflected in cards 50 and 51.
1.7.2. The standard piece time for assembling, setting and disassembling one tool is determined by the formula
T ShLR = T shk + t^, 0.10)
food T - piece time for assembling, setting up and disassembling one instrument, min; T shi - piece time for assembling and setting up one tool, min; T shr - piece time for tool disassembly, min.
V * «b* T «p = T - K ’ 0-11)
where K is the correction factor for piece time depending on the device used.
T ShLR = T sh. + = t shn + t shn K = T shi (3 + K).
The most efficient operations are cheese-liquor-frostrao-restoration.
2.2 Labor standards for the organization’s key personnel
Let's look at the standardization of labor for key personnel using specific examples.
1. Organization, standardization and payment of labor for machine tools.
Multi-machine service- this is a type of service in which several machines are serviced by one worker. Multi-machine service can be individual or team. The division of labor in multi-machine teams can be qualification or functional; in some cases, so-called paired service is used, when, for example, two workers of the same profession and qualifications service several machines. Multi-machine maintenance is most profitable if the non-overlapping machine time is greater than the time of manual operations, active monitoring and transitions. However, multi-machine maintenance is often economically feasible even when this time balance is disrupted, in particular when there is a labor shortage, when there is free equipment.
To establish time standards for each element of a production operation, regardless of the form of labor organization, analytical and calculation work is carried out separately. In this case, they are guided by the provision that the standard time for an operation must satisfy the following basic conditions:
1) the technological process provides for the rational and complete use of technical means: equipment, devices, tools and mechanisms involved in the work;
2) the processing mode is established on the basis of best practices;
3) the working day is fully loaded with productive work.
Let's consider the procedure for rationing main and auxiliary time.
Processing modes on the machine are selected by the technologist depending on the material, tool and equipment. The main time is determined by formulas depending on the type of work (turning, milling) for each transition separately.
When working on metalworking machines, the rate of expenditure of basic machine time can be determined by formula (9):
to = li/n * S, (9)
where to is the norm of the main time, min; l is the estimated processing length, mm; i is the number of passes; n is the number of revolutions or double moves available on the machine in one minute; S is the feed rate of the cutting tool per one revolution or double move , mm.
Rationing of auxiliary time is carried out using standards that are established depending on the type of production: more differential - in mass production, the most integrated - in individual production. In this case, complexes of labor auxiliary techniques are first determined. Thus, in mass production, auxiliary time for an operation is normalized according to the following sets of techniques:
1) Time to install and remove the part. Time standards for installing and removing a part in general machine-building standards for auxiliary time are given for typical installation and fastening methods, taking into account their location when installed manually at a distance of 0.5-1 m from the machine.
2) The time associated with the transition consists of the time for bringing the tool to the workpiece or machined surface, setting the tool to size, turning on the feed and rotating the spindle to take test chips, measuring when taking test chips, turning on spindle rotation and feed, retracting the tool and etc.
3) The time associated with changing the operating mode of the machine and changing the tool consists of the time of techniques for changing the spindle speed or table strokes, the feed rate, changing the tool, moving parts of the machine and devices.
4) Time for control operations includes the time spent on control measurements, which are carried out after completion of surface treatment.
The specifics of remuneration for a multi-machine operator are determined, first of all, by the need to take into account the degree of his employment during a work shift and establish appropriate additional payments to tariff rates. They are established depending on the relationship between the standard and project employment of the worker. The maximum level of additional payments, as a rule, should not exceed 30% of the tariff rate. This level corresponds to the equality of the project and standard levels of employment, that is, additional payments increase as the project employment increases, but only as long as the worker has time to rest during the shift.
2. Organization, rationing of stamping and foundry work.
When rationing forging and stamping work, which includes hot stamping under hammers and presses, upsetting on horizontal forging machines and free forging, the following features of this type of metal processing should be taken into account:
1) The presence of two parallel processes - heating of workpieces, deformation of the metal and the need to separately determine the time for heating the workpieces, stamping (forging) and cutting parts.
2) The team nature of the work and the need to ensure an even load on each team member.
3) Insignificant specific weight of metal deformation time in the normal piece time.
4) The need to determine auxiliary time for individual operations and techniques.
5) The need to use a differentiated standardization method for calculating manual and machine time.
6) Establishing a standard time for forging and stamping work based on the longest operational time of all team members, since when the process of heating blanks is carried out in parallel with the process of metal deformation, the work is organized in such a way that the heating time of the blanks overlaps with the forging time and partially with the time of servicing the workplace, Therefore, heating time is usually not included in the standards.
The rate of piece time for forging on hammers and presses, depending on the scale of production of blanks, is calculated by formula (10):
tsht = (∑(to * Ky+ tv) * (1 + (αobs + αotl) / 100) * Km + tnshtv) * Kn, (10)
where to is the main time of one hammer blow; Ky is the number of blows required to deform the metal; Km is the correction factor for forging different grades of steel; tнштв is the auxiliary time for free forging associated with the product; Kn is the correction factor taking into account changes in the pace of work depending on the batch size.
The correction factor values are given in Table 28.
Table 28
Correction factor K valuesn
In the “General Mechanical Engineering Time Standards for forging on hammers and presses,” auxiliary time is given taking into account the time of breaks for rest and personal needs and the time of breaks associated with the organization of the technological process.
3. Organization, standardization of metalwork, assembly and welding work.
Metalworking work on processing workpieces is the cold processing of metals by cutting, performed with hand or mechanized tools. This processing aims to give the part the required shape, size and surface roughness by cutting with a hacksaw, chopping, filing, scraping, drilling, threading and chamfering, deburring
and so on.
The technological features of the listed processes are characterized by the tools and equipment used for this work. In assembly work, operations can be carried out directly at assembly points without installing the product in a vice or on a workbench.
Rationing of plumbing and assembly work is carried out in the following sequence:
1) establishing the object, purpose and method of standardization;
2) analysis of actual metalwork processing and assembly operations, identification of compliance of the organization of work in the workplace with the requirements of labor regulations, selection of a rational option for its technological content, ensuring the least amount of working time while complying with the technical requirements for processing;
3) selection of standards for rationing in accordance with the type of production, nature of the work;
4) designing the content of work according to work methods and identifying the compliance of actual working conditions with normative ones;
5) calculation of operational time for an operation based on determining the duration of individual elements of work according to regulatory materials. Operating time is determined by formula (11):
Top = ∑topi * k, (11)
where topi is the operational time for performing the i-th calculation complex of work, min; k is the total correction factor for changes in working conditions when performing the i-th calculation complex.
In the conditions of small-scale and individual production, operational time is not allocated when rationing metalwork and assembly work, and the calculation is carried out in aggregate by piece time for each i-th calculation complex.
6) Calculation of time for workplace maintenance, rest and personal needs.
Plumbing and assembly work is mainly manual, so it is difficult to allocate auxiliary time. In the collections of standards for metalwork and assembly work (when rationing by operational time) there are two types of tables.
In the first type of tables, the time standard includes basic and auxiliary time, in addition to preparatory and final time, time for servicing the workplace and time for rest and personal needs. The time standard is set per unit of measurement.
In the second type of tables, operational time is given with the inclusion of auxiliary time related only to the tool or material being processed, but the time associated with the entire part or assembly is not included.
As for the standardization of welding work, we can say that in mechanical engineering electric welding, gas, contact and electron beam welding are used.
Here, the main time is the time during which the weld is formed by melting the base and filler material (electrode, electrode or filler wire).
The main time for welding 1 m of seam is determined by formula (12):
to1I = (60 * F * Þ) / (J * αн), (12)
where F is the cross-sectional area of the seam, mm2; Þ - specific gravity of the deposited metal, g/cm3; J - welding current, a; αн - deposition coefficient, g/a * h.
The most common elements of auxiliary time, depending on the product and type of equipment for all types of arc welding, include time for installation, rotation, removal of the product, fastening and detaching parts, and moving the welder. For all types of arc welding it is installed according to standards.
In automatic and semi-automatic (cassette) welding, the time spent on refilling one cassette is separately allocated. The list of costs is given in Table 29.
Table 29
Time for one cassette refill
Refilling method |
Cassette characteristics |
Time for one |
|
weight, kg |
|||
Closed |
|||
Mechanized |
Open |
||
Closed |
|||
4. Features of standardization of automated production operations.
The automated production process shows that when organizing labor, its forms are influenced by the presence of automatic systems and devices.
The main way to automate the processes of mechanical processing of parts for small-scale and individual production is the use of machines with computer numerical control (CNC). CNC machines are semi-automatic or automatic, all moving parts of which perform working and auxiliary movements automatically according to a pre-set program. Such a program includes technological commands and numerical values of the movements of the working parts of the machine. Resetting a CNC machine, including changing the program, requires little time, so these machines are most suitable for automating small-scale production.
A peculiarity of the standardization of operations of mechanical processing of parts on CNC machines is that the main time (machine) and the time associated with the transition constitute a single value Ta - the time of automatic operation of the machine according to the program compiled by the technologist-programmer, which consists of the main time of automatic operation of the machine Toa and the auxiliary time of operation of the machine according to the Tva program, that is (13), (14), (15):
Ta = Toa + Twa, (13)
Toa = ∑ (Li / sмi), (14)
Tva = Tvha + Toast, (15)
where Li is the length of the path traversed by the tool or part in the feed direction when processing the i-th technological section (taking into account plunge-in and overtravel); smi- minute feed in a given section; i = 1, 2, ..., n- number of technological processing sections; Twha -
time to perform automatic auxiliary moves (moving a part or tools from the starting points to the processing zones and retraction, setting the tool to size, changing the numerical value and direction of feed); Toast is the time of technological pauses and stops of feed and rotation of the spindle to check dimensions, inspect or change tools.
Flexible automated system(GPS) is a system of machines and mechanisms designed for processing various structurally and technologically similar parts in small batches one at a time without direct human intervention. The components of the GPS are the following subsystems: technological, transport, storage, instrumental maintenance and automated control using a computer.
The central element of the GPS is the flexible technological system (GTS), which is a set of multi-operational CNC machines (such as a machining center) that directly process objects.
Depending on the number of machines in the GPS, they are distinguished: flexible production module (FPM); flexible production line (GPL); flexible production site (GPU); flexible production workshop (GPC) and plant (GPP).
A flexible production module is a technological unit of equipment (CNC machine) equipped with manipulators or robots for loading and unloading parts and a tool magazine. The main feature of the GPM is the ability to work without human participation and the ability to integrate into a higher-ranking system. The flexible line consists of several modules equipped with transport and instrumental systems and controlled by a microcomputer. Flexible section - a type of GPL; it differs in the composition and interchangeability of technological equipment and mode of transport.
Transport and storage subsystem is a set of automated warehouses for blanks and parts, storage facilities at machines with automatic loading and unloading, and automatic vehicles used to move processed items from the warehouse to the machines and back (robot carts, conveyors, roller tables, etc. ).
The tool maintenance subsystem includes warehouses for tools and accessories, a department for preparing tools for work (sharpening, assembly, completing magazines, etc.) and a flexible automated system for installing, removing and moving tools from warehouses and back.
The automated control subsystem is a complex of technological tools with a computer capable of receiving information from automated systems of the enterprise: automated control systems (schedules), CAD (part drawing), ASTPP (technological process of processing and control of parts), converting it with using control programs, transmit commands directly to the executive bodies of the equipment of all GPS subsystems.
Thus, there are two resource flows in the GPS: material and information. The material flow ensures the implementation of all main and auxiliary operations of the process of processing objects: supply of workpieces, tools and their installation on machines; mechanical processing of parts; removing finished parts and moving them to the warehouse; tool replacement and relocation; control of processing and tool condition; removal of chips and supply of cutting fluid. The information flow ensures: the sequence, timing and number of processed items provided for by the work plans of the State Post Service; transfer of processing programs directly to the executive bodies of machine tools, work programs for robots, installation and transfer mechanisms, programs for providing workpieces, tools, auxiliary materials, programs for managing the entire complex and accounting for its operation, as well as group control of machines, transport and storage mechanisms, tool maintenance system.
The main features of flexible manufacturing systems are as follows:
1) State Fire Service employees are not directly involved in influencing the subject of labor. Their main task is to ensure efficient operation of the equipment. As the functions of workers change, the structure of their working time costs changes. The bulk of it is spent on setup, preventive maintenance and repair of equipment.
2) The number of units of State Fire Service technological equipment exceeds the number of workers in each group: adjusters, repairmen, electronics engineers, etc. Therefore, it is necessary to establish optimal ratios between the number of units of equipment and the number of workers of each group, and normalize the time spent in two aspects : in relation to equipment and workers.
3) In order to increase the level of reliability of the functioning of the GPS, complex end-to-end teams should be created with wages based on the final product. It should be taken into account that equipment downtime during and while waiting for maintenance is less, the wider the profile of each employee in relation to the functions performed and equipment service areas.
Theory and operating experience of existing gas stations show that at present, the norms of duration of operations in relation to equipment (norms of machine-tool intensity of operations), norms of labor intensity, norms of manpower and maintenance have the greatest practical importance.
For practical calculations of duration standards, it is necessary to proceed from the division of normalized time costs into direct and indirect. The former can be calculated quite accurately directly per unit of product of a given type. The latter relate to all products manufactured at a given workplace or site, and therefore are included in the standardized duration of the operation in proportion to the amount of direct costs.
The procedure for calculating labor standards in the State Border Service is as follows:
1) the coefficient of equipment utilization based on the automatic operation time required to complete the production program is determined;
2) standards for the employment rate of workers in each group are determined;
3) based on the relevant standards, a preliminary version of the labor intensity of work of each type and the number of staff for each group of workers is calculated;
4) the load factors of workers of each group are determined, corresponding to the adopted version of the staffing standards;
5) the time coefficient for automatic operation is established, corresponding to the adopted version of the staffing standards;
6) the load factors of workers of each group and the automatic work time are compared with their specified values;
7) the amount of costs for employees of all groups is determined;
8) for the variant of manpower standards recognized as optimal, the values of the norms for the duration of technological operations for each part are found;
9) based on the norms of number and duration, norms of labor intensity (time) are established for each part, each group of workers and for the team as a whole.
In the conditions of automated production, including flexible production systems, direct costs, as a rule, only include the time spent on automatic operation of equipment. It is advisable to include indirect time costs in the norm for the duration of operations, based on the following formula (16):
Nd = tа * (Tmel / (Tmel - Tnp)), (16)
where tа is the operating time of the machine in automatic mode when manufacturing a unit of product for a given operation; Tpl is the planned daily operating time of the GPS; Tnp is the duration of normalized breaks in the operation of technological equipment associated with maintenance and waiting for service by workers of all groups during Tpl.
The value of Tnp should include only those real interruptions in the operation of equipment that are objectively inevitable in the conditions of a particular gas station, based on the optimal equipment maintenance regulations, the established work and rest schedule for workers. The composition of consumer goods is determined by the design features of the analyzed system and operating conditions. As a rule, the Tnp value includes the duration of setup, adjustment, and testing work not covered by machine time, equipment downtime associated with regulated maintenance of mechanical, electrical, electronic and other subsystems, time for manufacturing and testing test parts, etc. etc. When establishing the composition of the Type, one should strive to overlap some works with others as much as possible, perform them in parallel, combine the functions of State Fire Service employees, and take advantage of the advantages of a team organization of labor and collective contracting.
In all GPS stations, the equipment is not turned off during workers’ rest, which must be installed on a sliding schedule. Therefore, time for rest and personal needs is not included in the TnP. It is taken into account when calculating the optimal standards of service and number, which are set at a level that allows for the implementation of standard rest time through mutual substitution of workers.
The second factor can be expressed through the coefficient of equipment utilization in terms of automatic operation time (17):
Tpl / (Tpl - Tnp) = Tpl / Ta = 1 / Ka, (17)
where Ta is the time of automatic operation of the equipment for the planned period of its operation Tpl.
The average standardized production time (standard duration) is determined by formula (18):
Нд = ta / Cap, (18)
where Cap is the planned equipment utilization rate based on automatic operation time.
Formula (18) is most convenient for practical rationing of the duration of operations, since it includes two parameters used in all basic technological and organizational planning calculations of the GPS.
For practical calculations, the following formula for the complexity of operations (19) is convenient:
Nt = (Nch / N * C * Ki) * Nd, (19)
where N is the total number of GPS modules; C is the number of equipment shifts; Ki is the planned equipment utilization rate.
When calculating the total employment of State Fire Service employees, it is advisable to separately take into account their employment with the main functions - performing production work and additional ones - performing supporting work (20):
Kz (X) = Kp (X) + Ko (X), (20)
where Kp(X) and Ko(X) is the coefficient of employment of workers of this group performing relevant production and support work.
The optimal number of State Fire Service personnel is established based on relations (21), (22):
Kz (X) ≤ Kzn, (21)
Ka (X) ≥ Kan, (22)
The coefficient Ka(X) is determined for each variant of the number of employees according to formula (23):
Ka (Nch) = Tpl - Tnp (Nch), (23)
where Tnp (Nch) is the duration of standardized breaks in equipment operation, depending on the adopted version of the number of workers, the form of division and cooperation of labor, equipment maintenance regulations, work and rest regime.
In automatic lines (including rotary and rotary-conveyor lines), the following are used to standardize labor: personnel standards; standards for the duration of production operations; time standards (labor-intensity of operations) for individual groups of workers and as a whole for the team servicing the line; production standards; standardized tasks.
The main role is played by the standards for the number of personnel (adjusters, repairmen, electricians, electronics workers) servicing the line in accordance with the established regulations and ensuring the implementation of the production program.
The basis for calculating the rate of time and production in the conditions of automatic lines is the technical (certified) productivity of the line rm, which determines the number of units of product that can be obtained from this equipment per hour or in another unit of time when operating in automatic mode.
The production rate is set based on the technical performance of the unit and the line utilization factor based on the automatic operation time (24):
Нв = rm * Kan, (24)
After determining the production rate, the labor intensity (time) rate for the i-th group (profession) of workers is found (25):
Nti = Tpl * (Nchi / Nv), (25)
Based on the norm of numbers, time and output, a standardized task is established. It indicates the scope of work for regulated maintenance of the line in the planned period, the time to complete these works, the standard number of workers, the planned volume of production of the line.
If several types of products are manufactured on an automatic line, then calculations of time and production standards can be carried out based on sets of products. Along with this, for multi-subject lines, it may be more expedient to calculate the norms of duration Nd and labor intensity Nt according to the methodology for GPS. In this case, calculations are performed using formulas (26), (27):
Ndk = tak / Kan, (26)
Ntk = Nch * (Ndk / No), (27)
where tak is the time of automatic operation of equipment in the manufacture of parts of the kth type.
Lecture 6. Standardization of work performed on machines with numerical control
Standardization of work performed on numerically controlled machines
The use of computer numerical control (CNC) machines is one of the main directions in the automation of metal cutting, which makes it possible to free up a large number of universal equipment, as well as improve the quality of products and the working conditions of machine operators. The fundamental difference between these machines and conventional ones is that the processing program is specified in mathematical form on a special program medium.
The standard time for operations performed on CNC machines when working on one machine consists of the standard preparatory and final time and the standard piece time:
Preparatory and final time is determined by the formula:
where T pz - time for setting up and setting up the machine, min.;
T pz1 - time for organizational preparation, min.;
T pz2 - time for setting up a machine, device, tool, software devices, min.;
T pr.obr - time for trial processing.
The rate of piece time is calculated using the formula:
T c.a - cycle time of automatic operation of the machine according to the program, min.;
K t in correction factor for the time of performing manual auxiliary work, depending on the batch of processed parts.
where T o is the main (technological) time for processing one part, min.;
T mv - machine-auxiliary time according to the program (for supplying a part or tool from the starting points to the processing zones and removal; setting the part to size, changing tools, changing the magnitude and direction of feed, time of technological pauses, etc.), min.
L i is the length of the path traversed by the tool or part in the feed direction when processing the i-ro technological section (taking into account the time of cutting in and overtravel), mm;
S mi - minute feed in a given technological section, mm/min.;
i=1,2…n - number of technological processing sections.
The main (technological) time is calculated based on cutting modes, which are determined according to General Machine-Building Standards for time and cutting modes for standardizing work performed on universal and multi-purpose machines with numerical control. According to these standards, the design and material of the cutting part of the tool is selected depending on the configuration of the workpiece, the stage of processing, the nature of the allowance being removed, the material being processed, etc. It is preferable to use a tool equipped with hard alloy plates (if there are no technological or other restrictions on their use). Such limitations include, for example, intermittent processing of heat-resistant steels, processing of small-diameter holes, insufficient rotation speed of the part, etc.
The cutting depth for each processing stage is selected in such a way as to ensure the elimination of processing errors and surface defects that appeared at previous processing stages, as well as to compensate for errors arising at the current processing stage.
The feed rate for each processing stage is assigned taking into account the dimensions of the surface being processed, the specified accuracy and roughness of the material being processed, and the cutting depth selected at the previous stage. The feed rate selected for the roughing and semi-finishing stages of processing is checked based on the strength of the machine mechanism. If it does not satisfy these conditions, it is reduced to a value acceptable by the strength of the machine mechanism. The feed selected for the finishing and finishing stages of processing is checked to ensure that the required roughness is obtained. The smaller of the innings is finally selected.
Cutting speed and power are selected in accordance with previously determined tool parameters, cutting depth and feed.
The cutting mode at the roughing and semi-finishing stages is checked by the power and torque of the machine, taking into account its design features. The selected cutting mode must satisfy the following conditions:
where N is the power required for cutting, kW;
N e - effective power of the machine, kW;
2M - double cutting torque, Nm;
2M st - double torque on the machine spindle, permissible by the machine according to the strength of the mechanism or the power of the electric motor, Nm.
Double cutting torque is determined by the formula:
P z is the main component of the cutting force, N;
D - diameter of the treated surface, mm.
If the selected mode does not meet the specified conditions, it is necessary to reduce the set cutting speed according to the value, permissible power or torque of the machine.
Auxiliary time associated with performing an operation on CNC machines involves performing a set of works:
a) related to the installation and removal of a part: “take and install the part”, “align and secure”; “turn on and off the machine”; “unfasten, remove the part and put it in a container”; “clean the device from shavings”, “wipe the base surfaces with a napkin”;
b) related to the performance of operations that were not included during the automatic operation cycle of the machine according to the program: “turn on and off the tape drive mechanism”; “establish the specified relative position of the part and the tool along the coordinates X, Y, Z, if necessary, make adjustments”; “check the arrival of the tool or part at the specified point after processing”; “move the punched tape to its original position.”
In general, auxiliary time is determined by the formula:
where Tv.u is the time for installing and removing the part manually or with a lift, min.;
T v.op - auxiliary time associated with the operation (not included in the control program), min.;
T v.meas - auxiliary non-overlapping time for measurements, min.
Auxiliary time for control measurements is included in the standard piece time only if it is provided for by the technological process, and only when it cannot be covered by the cycle time of the automatic operation of the machine.
Correction factor (K t in) for the duration of manual auxiliary work, depending on the batch of parts being processed, is determined from the table. 4.7.
Table 4.7
Correction factors for auxiliary time depending on the size of the batch of processed parts in mass production
Correction factors for auxiliary time depending on Map No. 1
on the batch size and processed parts in mass production
| Item no. | Operating time (Tsa+TV), min., up to | Type of production | |||||||||
| Small-scale | Medium production | ||||||||||
| Number of parts in the batch, pcs. | |||||||||||
| 1,52 | 1,40 | 1,32 | 1,23 | 1,15 | 1,07 | 1,00 | 0,93 | 0,87 | |||
| 1,40 | 1,32 | 1,23 | 1,15 | 1,07 | 1,00 | 0,93 | 0,87 | 0,81 | |||
| 30 or more | 1,32 | 1,23 | 1,15 | 1,07 | 1,00 | 0,93 | 0,87 | 0,81 | 0,76 | ||
| Index | A | b | V | G | d | e | and | h | And | ||
Maintenance of the workplace involves performing the following work:
· changing a tool (or a block with a tool) due to its dullness;
Let's consider what the process of standardizing adjustment work on CNC machines is and why it is needed.
When developing complex processes for processing workpieces for CNC machines and the programs that control them, the main criterion is the standard time for manufacturing parts. Without it, it is impossible to calculate the salary for machine operators, to calculate such indicators as labor productivity and equipment load factor.
Start of the process
Typically, workers need to spend additional time on the procedure for approaching and retracting, changing modes, and changing tools. Therefore, the duration of the setup period is also taken into account as part of the time costs for processing parts. Labor standardization begins with timing in the operating conditions of the machine. Using a stopwatch, the time required to install one part on the machine and then remove it is recorded.
Minutes are spent on maintenance of the place of work, the immediate needs of the operator. When working on a rotary lathe (single-column), it takes 14 minutes, and on a two-column machine - 16 minutes.
What is included in workplace maintenance?
The machine maintenance process includes:
- organizational measures - inspection of the machine, warming it up, testing of equipment: running in the hydraulic system and CNC. It takes some time to complete the task (work order, drawing, software) and receive instructions and tools from the master; present the first sample of the part received to the quality control department, lubricate and clean the machine during the shift, clean the work area after its completion. The constant time costs for performing a set of organizational works on rotary turning equipment, in accordance with the standards, are 12 minutes. When additional maintenance efforts are required, an appropriate amendment is introduced;
- technical measures - replacing a tool that has become dull; adjustment of machines throughout the shift and setup. There are other mandatory tasks: during the working process, chips must be constantly removed from the cutting or turning zones.
Time spent setting up the machine
The documents reflecting labor standards define the time for setting up equipment, depending on its design. If processing is performed on, the standards for installing and removing cutting tools are taken as the basis for the calculation.
When it is necessary to correct the positions of tools processing test parts, the period of processing the part is included in the duration of the preparatory stage.
Standards for setting up and maintaining automatic lathes are an important standard standard. They are included in the total time for the production of one part and, accordingly, they form the economic indicators of the employee and production as a whole.
Collections of normative documents
Standardizers of plants and factories where numerically and program controlled machines are used use the standards laid down in the documents when calculating working time:
- Unified Tariff and Qualification Directory of Works;
- All-Russian classifier of workers' professions;
- Unified qualification directory for positions of managers and specialists;
- Collections of labor standards for work performed to set up programmable equipment.
IMPORTANT! All this normative literature is basic for managers of all levels and personnel structures.
Without it, it is impossible to determine the time to complete certain amounts of work, the number of specialists that need to be involved, and the time standards used in the development of maps for technological processes.
Setup cards
For a machine of a certain type, a strictly standardized duration of production adjustment operations is developed and an adjustment map is assigned to it. When developing, many factors are taken into account in order to obtain the final picture.
The time limit allocated to the machine operator provides for:
- specifics of the procedure for diagnosing the machine fleet;
- availability of several setup mode options;
- compliance with service requirements.
In order to determine the labor intensity rate (unit of measurement - man-hours or man-minutes) of any work, the time during which one part is processed on a given machine is taken into account. The standardizer also operates with the concept of a piece time standard, which determines the total time in accordance with the types of work.
Accordingly, the total time is divided into main and auxiliary segments, office maintenance activities; transitions between machines during multi-machine maintenance; monitoring the work process; pauses caused by equipment operation.
The Institute of Labor has the results of standardization for equipment of milling and drilling-boring groups; lathes and automatic lines are provided with standards.
IMPORTANT! Knowing the standards, managers determine the worker’s degree of employment (his work intensity is calculated), distribute work zones and set the optimal work pace.
Multi-machine maintenance - approaches to timing
In factories with a high degree of automation, multi-machine maintenance of CNC machines is practiced (forms of labor organization - in teams, units and individually). Accordingly, service areas are assigned.
Multi-machine maintenance includes time spent on:
- preheating of equipment at idle speed, if this is provided for in the operating instructions for turning equipment;
- work according to the machine control program with workplace maintenance;
- installation of workpieces, removal of parts and quality control;
- meeting the personal needs of the operator;
- loss of the planned plan;
- performing the preparatory and final stage of work;
Multi-machine labor is classified according to work; zones, types and systems; functions performed by a multi-machine operator.
Machine maintenance systems and methods
Enterprises practice a cyclic maintenance system - at workplaces and production lines for machines that have an equal or similar length of time during which the part is processed. She is characterized by a constant flow of demands. Non-cyclical is that the operator immediately goes to service the machine where the automatic operation mode has ended. It is characterized by occasional service requirements.
Other methods are also possible:
- sentry - a worker monitors the entire machine park assigned to him, simultaneously determining the need for maintenance. With priority, the priority in service is determined by the operator, based on the cost of the parts being processed.
- route, it involves walking around a group of machines along a predetermined route.
Servicing several machines with the same or different duration of workpiece processing operations has its own nuances. However, all of them are subject to standardization during the careful development of the production process.
Conclusion
On CNC machines, to standardize adjustment work, you need to take into account many nuances when calculating the duration of various operations.
When determining the final processing time of a part on one machine (we are talking about turning or), the standards are calculated for the entire machine park.
For an operation performed on a CNC machine (015), we calculate the time norms according to the method given in the literature, Part 1, and for the remaining operations according to an enlarged method given in the literature.
Piece time is determined by the formula:
where T c.a. - cycle time of automatic operation of the machine according to the program, min. Includes the main time T about the operation of the machine according to a given program and T m.v. machine-auxiliary time.
T ca = VT mv + VT o (1.68)
Auxiliary time is defined as the sum of the time for installing and removing the part, the time for securing and unfastening the part, the time for measuring the part and the time for operating the machine.
T in =T us +T v.op. +T v.meas (1.69)
where T ac is the time for installing and removing the part, min;
T v.op. - auxiliary time associated with the operation. Includes time for control, installation and removal of the shield that protects against splashing of the emulsion during processing, checking the return of the tool to a given point after processing, min;
T from - time to measure the part. This time is excluded from the calculation, since it is covered by machine processing according to the program for CNC machines, min.
Time for servicing a workplace consists of time for rest, time for organizational maintenance and time for maintenance of the workplace.
T technical - time for workplace maintenance.
Consists of: time for adjustment and adjustment of the machine during operation; time to change a dull tool; time to remove chips during operation. It is expressed as a percentage of operational time.
Torg - organizational maintenance of workplaces.
Consists of: time for laying out tools at the beginning of work and cleaning them at the end of the shift; time to inspect and test the machine at the beginning of the shift; time to clean and lubricate the machine.
T department - time for rest and personal needs.
Piece-calculation time is determined by the formula:
where N is the program for launching parts per year, pcs.; N=2400 pcs.,
S - number of launches per year;
T p.z. - preparatory and final time;
T p.z. =T p.z.1 +T p.z.2 +T p.z.3, (1.72)
where T p.z.1 - time for organizational preparation, min;
T p.z.2 - time for setting up the machine, device, CNC, min;
T p.z.3 - time for trial processing, min:
T p.z.3 =T p.obra. +T c.a. (1.73)
Figure 1.10 - Cyclogram for determining the operating time of the machine according to the program for a turning operation with CNC 015
Machine 16K20T1:
Revolver head fixation time Tif =0.017 min;
Time to rotate the turret one position T ip =0.017 min
To determine the time of automatic operation of the machine according to the program, we will draw up table 1.9.
Table 1.9 - Time of automatic operation of the machine according to the program. Operation 015
|
Trajectory section or position numbers of the previous and working positions |
Increments along the Z axis Z, mm |
Increments along the X axis X, mm |
Length of the i-th section of the trajectory |
Minute feed on the i-th section of the trajectory, mm/min |
The main time of automatic operation of the machine T o, min |
Machine-auxiliary time T mv, min |
The total cycle time of the automatic operation of the machine according to the program when processing a part in operation 015:
T c.a. =5.16+0.71=5.87 min.
Time to install and remove the part, T ac =0.24 min
Auxiliary time associated with the operation, T v.op =0.15+0.03+0.05=0.23 min;
Time to measure a part, T in measurements =0 ? the time is covered by processing the part on the machine according to the program.
Auxiliary time:
T in =0.24+0.23+0=0.47 min;
Operating time:
T op =5.06+0.47=5.53min;
a tech +a org +a dept =8%
We determine the piece time for operation 015:
We determine the piece-calculation time:
Time for organizational preparation:
T p.z.1 =13 min;
Time to set up a machine, fixture, tool, CNC:
T p.z.2 =19.4 min;
Time for trial processing:
Tp.z.3=3.54+5.06=8.6 min;
Total preparatory and final time:
T p.z. =13+19.4+8.6=41 min;
Parts lot size:
S=12 ? (vol. 1 p. 604)
Table 1.10 - Results of calculations of time standards
