Under the technical norm of time, it is customary to understand the time required to process a particular part in a certain technological process of its manufacture.

The technical norm of time is established on the basis of the most advanced production technology, the most economically expedient use of machine tools and tools, and the rational organization of labor, taking into account the experience of advanced production workers.

When determining the technical norm of time, it must be borne in mind that, firstly, the machine operator must not perform the work that is provided for auxiliary workers (for example, bring material, etc.), and secondly, losses associated with with organizational and technical problems, the time norm should be based on the conditions for uninterrupted maintenance of the workplace, and, finally, thirdly, processing allowances, grade and quality of the material must comply with the specifications.

Deviations from these normal conditions are specially taken into account by the normalizer in each individual case.

In case of deviation from normal working conditions, the worker receives a separate extra charge to compensate for the additional cost of his labor.

The production rate determines the amount of work that must be completed in a certain time (per hour or during a shift). The production rate is measured by the number of parts manufactured per hour or more often - per shift.

The rate of production depends on the rate of time; it can be determined only after it becomes known how much time must be spent on the manufacture of one part.

If we denote the norm of time through N vr in minutes, and the norm of output through N vyr, then the norm of output for a seven-hour working day will be N vyr \u003d 420 / N vr pcs.

From this it can be seen that the smaller the norm of time, the greater the norm of output, i.e., the higher the productivity of labor.

The norm of time for the performance of a particular work, as well as the norm of production, is not unchanged. These norms change with a change in the technological process, with the introduction of automation and mechanization, as well as with an increase in the technical culture of production.

It has been established that the technical norm of time determines the time required for the manufacture of one part.

This time is usually called piece time; it is denoted by T pcs.

Piece time consists of a number of elements:

T pcs \u003d T o + T in + T t.ob + T org.ob + T p min,

where T about - the main (machine) time; T in - auxiliary time; T sob - the time of maintenance of the workplace; T org.ob - time of organizational maintenance of the workplace; T p - time of breaks in work.

The main time is the time during which the cutting process is carried out.

The main time can be:

A) machine, if chip removal occurs during the mechanical feed of the table;

b) machine-manual, if chip removal occurs when manually feeding the table with the product.

Auxiliary time is spent on setting up, aligning and removing the workpiece, starting and stopping the rotation of the spindle, turning the feed on and off, approaching and retracting the table to the tool and controlling the machine, as well as setting the tool to a given size and controlling the workpiece.

The sum of the main and auxiliary time is the time of operational work.

Operational time (T op) is the time spent on work, the direct result of which is the execution of a given operation:

T op \u003d T o + T in.

The maintenance time of the workplace is the time spent on installing (shifting), adjusting (adjusting) the tool, as well as removing chips.

The time of organizational maintenance of the workplace consists of the time spent on cleaning, lubricating, inspecting and testing the machine. Often, when determining the rate of piece time, the service time of the workplace (T about) is not divided into its constituent parts:

T about \u003d T t.ob + T org.ob.

The time of breaks in work is spent on breaks for rest and natural needs of the worker. The duration of breaks for rest depends on the working conditions and is included in the working time when performing physically difficult work.

In addition to piece time, when determining the technical norm of time for a particular technological operation, it is necessary to take into account the preparatory and final time.

Preparatory and final time (T p.-h) is spent on familiarization with the drawing and the technological process; receiving instruction from the master; installation and removal of tools and fixtures, as well as registration and delivery of finished products.

Preparatory and closing time is spent by the worker once to complete a given production task, and its duration does not depend on the number of parts in the batch (on the size of the batch of parts).

The preparatory-final time (T p.-z) has to be taken into account when determining the piece time for various costing (preliminary) calculations, for example, to establish the cost of manufacturing a part. In these cases, a part of the preparatory and final time is added to the piece time, which falls on one part, i.e.

T sh.-k \u003d T pcs + T p.-z / n min,

where n is the number of parts in a given lot.

Time limit per game(T parts) is determined according to the following equation:

T part \u003d T piece * n + T p.-z min.

The main (machine) and auxiliary time are of the greatest importance in the piece norm of time, since the cutting process, on which the main time is spent, and all the working methods, on which the auxiliary time is spent, are repeated when processing each part from the batch.

The cost of the main (machine) time during milling depends on the total allowance for processing, the required number of passes, the estimated length of processing and the value of the minute feed. This dependence is expressed by the equation

where L is the estimated processing length in mm;

l is the length of the treated surface (according to the drawing) in mm; l 1 is the length of the plunge path and overrun of the tool in mm (determined depending on the type of cutter and how it is installed); l 2 - additional length for taking test chips in mm; s m - minute feed in mm / min; h - machining allowance in mm; t - depth of cut in mm.

The ratio h/t determines the number of passes i.

Auxiliary time costs for each of its constituent elements are determined according to special tables 1 . According to the same tables, the norm of preparatory and final time is determined.

1 "General machine-building standards for cutting modes and time" (for technical regulation on milling machines), Mashgiz, 1960.

The service time of the workplace and the time of breaks in work are not specially calculated, but are taken in the amount of a certain percentage (usually 4-6%) of the value of the operational time.

The norm of time is the time required to complete an operation in certain organizational specifications based rational use production possibilities equipment and workplace, taking into account advanced technologies. Piece time tw for non-automated production consists of: tw = totvtttorgtp to main technological time t in auxiliary time tt technological maintenance of the workplace torg organizational maintenance tp for a break. Most of the time to is spent on...

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Lecture 3rd year.

Technical norm of time.

The complexity of operations is calculated on the basis of technical standards.

The norm of time called the time required to perform the operation in certain organizational and technical conditions, based on the rational use of production capabilities, equipment and workplace, taking into account advanced technologies.

The time limit is expressed in hours or minutes and is set separately for each operation.

The technical norm of production (Nv) is the reciprocal of the norm of time.

The production rate expresses the number (n) of products (parts) produced per unit of time

Hb=

n - number of products

Three methods of setting standards:

Based on the study of the cost of working time through observations;

according to known standards.

By comparison and calculation according to standard norms

With the 1st method: the norm is set by observing the random time spent directly in the production conditions at the workplace. This method is used to develop regulations

With the 2nd method, the duration of operations is calculated using the standards for the duration of the execution of individual elements of the operation.

With the 3rd method, the normalization of the operation is carried out approximately taking into account the standard norms.

The 1st and 2nd methods are used in mass and batch production, the 3rd method in single and small-scale production.

The norm of time for the operation of processing one workpiece or assembly of one unit is called piece time..

Piece time (t w) - for non-automated production consists of:

t w \u003d t o + t in + t t + t org + t p

t o basic (technological) time

t in - auxiliary time

t t technological maintenance of the workplace

t org organizational services

t p for a break.

Main time t o , is spent on changing the shape, dimensions of the workpiece (on the machine, welding, forge, locksmith, etc.) t o time spent on assembling the assembly, etc.

When processing on machines:

t o =

L p Estimated machining length (tool stroke in feed direction)

i number of tool strokes

sm minute tool feed (mm\min)

With manual approach

Lp = L + L in + Lcx

L processing length

L in tool insertion length

L with x Tool drop size

lp no-load path of the tool approach to the workpiece to facilitate the work of the tool at the beginning of the cut, on a multi-cutting turning tool

Values ​​l p; l in; lcx ; taken from standard tables.

l in t ctgα turning

where when drilling t depth of cut

l in \u003d 0.3 d d drill diameter

t in auxiliary time, actions that ensure the execution of work elements (compression and installation of the workpiece, starting and stopping the machine, switching processing modes, etc.)

t op sum

t op = to + t in

t op - operational time spent on the execution of each operation ( t op - the main part of the technical map)

tT maintenance time (tool change, tool dressing, machine adjustment)

t org time allocated for the care of the workplace, lubrication of the machine, cleaning of tools.

t org set according to the standards in% of the operational time

t org \u003d (0.4 ... 0.8) t op

time t n for rest and personal needs regulated by law. Also in % of t op

t p \u003d 0.25 t op

Piece time: can be expressed in terms of coordinates

T w= t op (1+α+β+γ)

α-coefficient of maintenance time

β-coefficient establishing the time of organizational service

γ- coefficient of time for rest, etc.

Preparatory and closing time

In serial production, it is necessary to take into account the preparatory-final time: t pz, which is spent by the worker before starting the processing of a batch of blanks or assembly units and after the end of the task (preparatory and final)

The preparatory part includes: receiving the task, getting acquainted with the work, setting up equipment for installing fixtures.

The final part includes: delivery of work performed, removal of equipment, devices, putting things in order at the workplace

Addition:

1. Production characteristics

Mass

Serial (large k-2..5

Average k-5..10

Small k > 10)

1. Basing

Represents the establishment of technically sound norms for the consumption of production resources (GOST 3.1109-82). At the same time, production resources are understood as energy, raw materials, materials, tools, work time etc.

Technical regulation

When designing technological processes, a particularly important task is the technical regulation of technological processes, that is, the regulation of labor.

The norm of time is called the regulated time for the performance of a certain amount of work in specific production conditions by one or more performers of appropriate qualifications. Usually, a technological operation is taken as a unit of the volume of work.

Time limits can be determined by various methods.

Experimental-statistical method of normalization

The experimental-statistical method of technical rationing involves setting the time norm for the entire operation by comparing it with the norms for performing similar work in the past. The basis of this method is the qualification and personal experience rater. Scope - single and small-scale production.

Calculation and analytical method of normalization

The essence of this method lies in the fact that the elements of the technological operation are normalized: technological and auxiliary transitions, etc. Such a time norm is called technically justified.

Piece and piece-calculation time

Depending on the type of production, either piece-calculation time Tsht-k or piece Tsht can be calculated. The structure of these rules is as follows:

Tsht-k \u003d Tsht + (Tp.z. / n) (min), (4.10), where

Tsht \u003d To + Tv + Ttech.service + T org.service + T otd

Let's take a look at each of these times:

That is the main time;

TV - auxiliary time;

Ttech.service - time for maintenance;

Trade.service - time for organizational service;

Todd - time for a regulated break (for rest);

Tp.z. - preparatory closing time;

n is the number of products in the batch;

The sum To + TV - is called the operational time Top.

regular time

regular time in the case of technical standardization of machining, it is calculated for each technological transition. This part of the piece time is spent directly on changing or determining the state of the object of labor:

That \u003d Lp / Smin * i (min), (4.11), where

Lp - estimated processing length, mm (Figure 4.3);

Smin - minute feed, mm / min;

i - the number of working moves;

Lр = Ldet + lvr + Lout (mm),

where Ldet is the length of the machined surface of the part according to the drawing, mm;

Lvr - tool tie-in length, mm;

Lout - tool stroke length, mm.

Lvr is designed to ensure the safe entry of the tool into the workpiece at the working feed, and Lout - to ensure its surface exit after the end of its processing. In cases of non-pass machining, blind hole drilling, and the like, the tool may not travel. This must be taken into account when determining the effective processing length.

Figure 4.3 - Components of the estimated processing length

Auxiliary Time Tv - part of the piece time spent on the implementation of the techniques necessary to ensure the possibility of processing and further determining the state of the object of labor (installation and removal of the workpiece, machine control, measurement of dimensions).

Auxiliary time rationing

Performing technical rationing, the calculation of auxiliary time is performed using time standards with varying degrees of detail.

Service Time Tob workplace - part of the piece time spent by the contractor to support the technological equipment in working condition and care for it and the workplace.

Maintenance of the workplace is divided into organizational and technical.

Time spent on maintenance Ttech.obs provide for the implementation of tool change, which is dull, adjustment and adjustment of the machine, etc.

Time for organizational service Trade.obs provided for the maintenance of the workplace - testing and inspection of equipment, receiving instructions during the shift from the foreman or foreman, cleaning and lubricating equipment, cleaning the workplace, etc.

Technical and organizational services are set according to time standards as a percentage of operational time (up to 4-8%).

Rest time and personal needs

Technical regulation implies allocation time for rest and personal needs Todd - part of the piece time spent by the worker for personal needs and (during tedious work) - for additional rest. This time is determined as a percentage of the operating time. For machine shops, it is approximately 2.5 - 4% of the operational time.

Preparatory and closing time

Tp.z. - the time interval spent on preparing equipment and technological equipment for performing a technological operation and streamlining the latter after the completion of the operation. It is assigned to the entire batch of blanks to be processed in the operation. This time is determined according to the standards, which include the adjustment of technological equipment; familiarization with the work (drawings, technological process, instructions, etc.); receipt of materials, tools, as well as for work upon completion of processing a batch of blanks - delivery of manufactured parts, removal of technological equipment from the machine, bringing the equipment into working condition.

piece time

Piece-calculation Tsht-k time is determined in single, small-scale and sometimes medium-scale production for operations for which the worker himself performs the adjustment of equipment.

piece time is calculated for such types of production, when the equipment is set up by the adjuster, and the worker only performs work on it (medium-scale, large-scale and mass production).

Operation time

The cost of performing an operation during technical regulation can be calculated using the following formula:

Sop \u003d Tsht (Tsht-k) * C g.s.,

where Sop - the price for the operation; Tsht (Tsht-k) - the corresponding norm of time for the operation (hours) Cg.s. - hourly tariff rate worker of the corresponding category (rub).

In addition to the element-by-element normalization discussed above, methods such as timekeeping and photography of the working day are sometimes used in practice to establish the norm of time.

Timing and photography of the working day

By using timing study the time spent on the performance of cyclically repeated manual and machine-manual elements of the operation. It is used in the design of the rational composition and structure of the operation, to establish the normal duration of their elements and, on this basis, the conclusion of standards for calculating technically justified time standards. Timing is also used in the study of best practices in order to disseminate them.

Work day photo - also a method of technical regulation, which consists in the study and measurement of all time costs by observing during one or more changes. At the same time, in contrast to timekeeping, costs are fixed, not only associated with the execution of the operation, but also with the organization of production (temporary downtime for various reasons: lack of blanks, tools, etc.).

A technically justified norm of time is understood as the time required to perform a given amount of work (operation) under certain organizational and technical conditions.

The norm of piece time is the norm of time to perform the amount of work equal to the unit of rationing, to perform a technological operation.

The technical norms of time in the conditions of mass and serial production are established by the calculation and analytical method.

In mass production, the norm of piece-calculation time T sh-k is determined:

in mass production, the norm of piece time T pcs is determined:

T pcs \u003d t o + t in + t about + t from, (3.54)

where T p-z - preparatory and final time for a batch of parts, min.;

n is the number of parts in the tuning batch, pcs.;

t o - main time, min.;

t in - auxiliary time, min.

Auxiliary time consists of the time spent on individual techniques:

t in \u003d t u.s + t c.o + t o + t from, (3.55)

t c.s. - time to install and remove the part, min.;

t z.o - time for fixing and detaching the part, min .;

t pack - time for control methods, min.;

t out - time to measure the part, min.;

t about - time for maintenance of the workplace, min.

The time for maintenance of the workplace t about in mass and serial production is the sum of the time for organizational maintenance t org and the time for maintenance t of those workplaces:

t about \u003d t those + t org; (3.56)

t from - time of breaks for rest and personal needs, min.

The normalization of the operation is carried out in accordance with the selected processing methods.

In the course project, give an analytical calculation of the main time t o for only one operation. For all other operations, the main time can be set according to normative reference books or according to the basic technological process.

The main (technological) time t o is determined by the calculation for all processing transitions, taking into account the combination of transitions (for machine work) according to the formula

Where l- the estimated length of the surface to be machined (the estimated stroke length of the tool or workpiece in the feed direction), mm;

i– number of working moves;

S m - minute feed of the tool, mm / min.

In general, the estimated length of the machined surface

l = l o + l vr + l P + l cx , (3.58)

Where l o is the length of the treated surface in the feed direction, mm;

l vr – tool insertion length, mm;

l P – length of the tool approach to the workpiece, mm;

lсх - length of overrun (descent) of the tool, mm.

Length l o taken from the drawing of the processed surface of the workpiece; l vr, l P, l cx is determined according to the standards ( l n = l cx  1…2 mm). Meaning l vp can be determined by calculation according to the processing scheme.

Auxiliary time is set according to the standards for each transition.

The sum of main and auxiliary time is called operational time.

t op = t o + t in (3.59)

The auxiliary time can be overlapped main time, partially overlapped and non-overlapped.

Overlapped time - the time for the worker to perform those techniques that are carried out during the period of automatic operation of the equipment. This time is not included in the standard time. Non-overlapping time - the norm of the time for the worker to perform techniques with the equipment stopped and the time spent on machine-manual techniques.

When transitions are performed sequentially, to determine the operational time, it is necessary to sum up all the main and auxiliary times for all transitions of this operation and only after that determine the remaining components of the unit time norm. When transitions are performed in parallel, the main and auxiliary time for the operation is taken according to the long processing transition.

Time Maintenance t of those is set as a percentage (up to 4-6%) of the main or operational time.

Organizational service time t org is set (up to 4-8%) of the operational time.

The time of breaks in work for rest t from is set as a percentage ( 2.5%) of the operational time.

Preparatory-preparatory t p-z - the time interval spent on preparing the performers and means of technological equipment for the performance of the technological operation and putting them in order after the end of the shift or the performance of this operation. This time is determined according to the time standards, which include the adjustment of technological equipment; familiarization with the work (drawing, process map, instructions); obtaining materials, tools, etc.; after the processing of a batch of blanks is completed - the delivery of manufactured parts, the removal of technological equipment from the machine, bringing the equipment into working condition, etc. The preparatory and final time is determined according to the standards, depending on the equipment and the nature of the work.

With multi-tool parallel, parallel-sequential or sequential processing (see Appendix 15), the main time is calculated by the formula (3.57) for each support. The total main time t o.gen is determined depending on the processing scheme.

For sequential processing

where h is the number of calipers or the number of sequentially working tools;

t o.s.last - the main time for each caliper or each tool.

With parallel processing

t o.total = t o.s.par. max , (3.61)

where t o.s.par. max is the longest main time of one of the calipers or one of the tools.

With parallel-sequential processing

(3.62)

Other components of the piece time for multi-tool processing are the same as for processing with one tool.

There are special standards according to which cutting conditions are set and individual elements of the piece time rate are determined when working on CNC machines. The use of CNC machines opens up opportunities for multi-machine work, the regulation of which is considered in the special literature.

The results of calculations of technical time standards are summarized in table 3.28.

Table 3.28

Summary table of technical time standards for operations

Labor intensity of operations

(3.63)

where m is the number of operations.

The category of work performed is determined by the tariff-qualification guide. For enlarged calculations, you can use the data below (Table 3.29).

Table 3.29

Average categories of work of machine operators

Enter all calculated values ​​of technical time standards into the route and operational charts of technological documentation.

The technical norm of time for processing a workpiece is one of the main parameters for calculating the cost of manufacturing a part, the number of production equipment, wages workers and planning
production.

Rationing - the establishment of technically justified norms of time.

The technical norm of time is the time required to perform a technological operation in certain organizational and technical conditions of production.

The norm of piece time is the norm for the execution of one piece.

The main technological time is the time directly spent for each technological transition.

Auxiliary time - time to install the part, install
instrument, measurement.

There are three normalization methods:

Method of technical calculation according to standards;

Comparison and calculation method according to enlarged standard standards;

The method of setting standards based on the study of the cost of working time.

In the first method, the duration of the operation is set by calculation on the basis of an analysis of the sequence and content of the actions of the worker and the machine.

With the second method, the time norm is determined approximately, according to enlarged standard standards. It is used in single and small-scale production.

In the third method, the time limit is set on the basis of
timing.

The most reasonable is the first method, according to which the norm of time, regardless of the type of machine and processing method, is determined
according to the formula:

T piece \u003d T o + T B + T TECH + T ORG + T P,

where T pcs - piece time to perform one operation, min;

T about - the main (technological) time, min, is determined;

T B - auxiliary time, min;

T TECH \u003d 6% × T O - time for maintenance of the workplace, min;

T OGR \u003d 8% × T O - the time of organizational maintenance of the worker
places, min;

T P \u003d 2.5% × T O - time of work breaks, min.

In conditions serial production additionally calculated piece-calculation time (T shk):

where - preparatory - final time, min;

- the number of parts in the batch, pcs.

Time limits are determined in the following sequence:

Ø for each transition calculate the main time T O

Ø determine auxiliary time:

T VSP= T CHECK + T SET INTR. + T CLOSE ,

where T CONTR - time to control the dimensions of the part;

T SET INTR. - time to install the tool;

T CLOSE - time to fix the workpiece.

Ø Calculate operational time:

T OP \u003d T O + T VSP;

Ø according to the standards, depending on the type of operations and equipment, time is set for servicing the workplace, rest and personal needs - T OGRN and T P (in% of the main time);

Ø determine the rate of piece time T pcs;

Ø For serial production, set the composition of the preparatory - final time. After that, the piece is calculated - the calculation time T sc. .

The necessary data for the calculation are indicated in.

After finding the norms of time, the obtained data are entered
to the table.

Table 7 - Norms of time for machining, min.

Making an explanatory note

An explanatory note (PZ) to the course project is drawn up in accordance with general requirements to text documents
GOST 2.105 - 95 and GOST 7.32 - 2001. The text part must be drawn up on A4 forms with frames and the main inscription.

In the explanatory note, the material must be presented in a logical sequence, convincingly and reasonably enough, with the necessary illustrations (diagrams, tables, graphs) and calculations.

Thus, the explanatory note should contain all of the above
indicated stages of the course work.

The text of the PP is divided into sections, subsections and paragraphs with the corresponding numbering.

Page numbering should be continuous: on the first page is the title page, on the second - the task for course work, on the third - the content, etc. Pagination starts from the third page.

In the PP, a "List of references" is required, which should include all the sources used in the order of references in the text; it is issued in compliance with the requirements of GOST 7.1 - 2003.

Registration of technological documentation

Technical documentation(TD) is detailed description production process, which includes the main characteristics, manufacturing method, control points and control methods. Technical documentation helps organizations visually demonstrate and track the correctness of the process, identify deviations or failures in a timely manner and prevent
production of poor quality products.

Technological documentation must comply with the requirements of the ESTD on the forms of the relevant forms in the form of an album, including:

Title page GOST 3.1105 - 84 (form 2);

Route map GOST 3.1118 - 82 (form 1, 1 b);

Operational cards for machining GOST 3.1404 - 86
(forms 2, 2a);

Sketch cards GOST 3.1105 - 84 (forms 7, 7a);

Form forms are given in Appendix E.

Route map - a document containing a description of the technological process of manufacturing the product, including control and movement through all operations in the technological sequence, indicating data on equipment, tooling, material and labor standards.

Operating card - description of the technological operation with indication of transitions, processing modes and data on the means of technological equipment. Operational cards are filled in for all machining operations.

Operational sketches are executed on the sketch map. On the operational sketch, the workpiece is shown in the state that it acquires as a result of performing a given operation.

The sketch indicates the necessary data for performing operations and for technical control:

Dimensions

Limit deviations

Surface finish symbols

Technological requirements

Technological bases.

Technological requirements are indicated in the free sketch field to the right of the image or above it. Required number of images
(views, cuts, sections) should be minimally sufficient for a visual and clear representation of the treated surfaces, setting
dimensions, technological bases and clamping forces.

All sizes of processed surfaces are numbered Arabic numerals in the clockwise direction.

The operating sketch should show all cutting
tools.