Production cycle. Types of machine-building production and their characteristics according to technological, organizational and economic features. Alphabetical index of terms
Release cycle calculation. Determining the type of production. Characteristics of a given type of production
The dependence of the type of production on the volume of production of parts is shown in Table 1.1.
With a part weight of 1.5 kg and N=10,000 parts, medium-scale production is selected.
Table 1.1 - Characteristics of the type of production
|
details, kg |
Type of production |
||||
|
single |
Small-scale |
Medium series |
large-scale |
Mass |
|
Serial production is characterized by a limited range of manufactured parts manufactured in periodically repeating batches and a relatively small volume of output than in a single production.
The main technological features of mass production:
1. Assigning several operations to each workplace;
2. The use of universal equipment, special machines for individual operations;
3. Arrangement of equipment by technological process, type of part or groups of machines.
4. Wide application specialist. Fixtures and tools.
5. Compliance with the principle of interchangeability.
6. Average qualification of workers.
The value of the release cycle is calculated by the formula:
where F d - the actual annual fund of the operating time of the equipment, h / cm;
N - annual program for the production of parts, N=10,000 pcs
Next, you need to determine the actual fund of time. When determining the fund of operating time of equipment and workers, the following initial data for 2014 were adopted at a 40-hour working week, Fd = 1962 h / cm.
Then by formula (1.1)
The type of production depends on two factors, namely: on a given program and on the complexity of manufacturing a product. On the basis of a given program, the cycle of product release t B is calculated, and the labor intensity is determined by the average piece (piece-calculation) time T pcs for operations operating in production or similar technological process.
In mass production, the number of parts in a batch is determined by the following formula:
where a is the number of days for which it is necessary to have a stock of parts, for = 1;
F - number of working days in a year, F=253 days.
Analysis of the requirements for the accuracy and roughness of the machined surfaces of the part and a description of the accepted methods for ensuring them
The part "Intermediate shaft" has low requirements for the accuracy and roughness of the machined surfaces. Many surfaces are machined to the fourteenth grade of accuracy.
The part is technological, because:
1. Free tool access is provided to all surfaces.
2. The part has a small number of precise dimensions.
3. The workpiece is as close as possible to the shape and dimensions of the finished part.
4. The use of high-performance processing modes is allowed.
5. There are no very exact sizes, except: 6P9, 35k6, 30k6, 25k6, 20k6.
The part can be obtained by stamping, so the configuration of the outer contour does not cause difficulties in obtaining the workpiece.
In terms of machining, the part can be described as follows. The design of the part allows it to be processed for a pass, nothing interferes this species processing. There is free access of the tool to the processed surfaces. The part provides for the possibility of processing on CNC machines, as well as on universal machines, it does not present difficulties in basing, which is due to the presence of planes and cylindrical surfaces.
It is concluded that, from the point of view of the accuracy and cleanliness of the machined surfaces, this part generally does not present significant technological difficulties.
Also, to determine the manufacturability of a part,
1. Accuracy factor, CT
where K PM - accuracy factor;
T SR - the average quality of the accuracy of the surfaces of the part.
where T i - quality of accuracy;
n i - the number of surfaces of the part with a given quality (table 1.2)
Table 1.2 - The number of surfaces of the part "Intermediate shaft" with a given quality
In this way
2. Coefficient of roughness, KSh
where K W - roughness coefficient,
Ra SR - average roughness.
where Ra i is the surface roughness parameter of the part;
m i - the number of surfaces of the part with the same roughness parameter (table 1.3).
Table 1.3 - The number of surfaces of the part "Intermediate shaft" with a given roughness class
In this way
The coefficients are compared with one. The closer the values of the coefficients are to one, the more manufacturable the part is. From the above, we can conclude that the part is quite technologically advanced.
Engineering technology- a science that studies and establishes the patterns of the flow of processing processes and parameters, the impact on which most effectively affects the intensification of processing processes and increasing their accuracy. The subject of study in engineering technology is the manufacture of products of a given quality in the quantity established by the production program, at the lowest cost of materials and the minimum cost.
Detail- this is an integral part of the product, made of a homogeneous material without the use of assembly operations. A characteristic feature of the part is the absence of detachable and one-piece connections in it. A part is the primary assembly element of every machine.
assembly unit is a product made up of constituent parts collected separately from other elements of the product. As components of an assembly unit, both individual parts and components of lower orders can act.
Manufacturing process is a set of interrelated actions, as a result of which raw materials and semi-finished products are converted into finished products. In concept manufacturing process includes:
In engineering, there are three type of production: massive, serial and singular.
AT mass production, products are manufactured continuously, in large quantities and for a long time (up to several years). AT serial- batches (series) of products that are regularly repeated at certain intervals. AT single- products are made in small quantities and, often, individually.
criterion, which determines the type of production, is not the number of manufactured products, but the assignment to the workplace of one or more technological operations (the so-called. coefficient of fixing technological operations k ).
This is the ratio of the number of all technological operations performed or to be performed to the number of jobs.
So, for mass production, it is characteristic that most jobs are assigned only one constantly recurring operation, for serial production - several periodically repetitive operations, for a single one - a wide variety of non-repeating operations.
Another distinguishing feature of production types is the release cycle.
, - the time interval through which the release of products is periodically produced.The release cycle is determined by the formula:
where F E- annual, efficient fund time of the workplace, section or workshop, h
P- annual production program for the release of a workplace, section or workshop, pcs.
AT- the number of days off in a year;
P p - quantity public holidays per year;
t p days - the duration of the working day, hour;
n cm - the number of shifts.
Plant production program- this is the annual number of manufactured products expressed in labor intensity:
where P 1 ,P 2 and P n- production programs for products, man-hour.
Production program of the shipyard (SRZ)
| Labor intensity of work by quarters, person · hour. | |||||
| Name | I | II | III | IV | TOTAL: |
| Ship repair: | |||||
| - navigational | XXX | XXX | XXX | XXX | P 1 |
| - current | XXX | XXX | XXX | XXX | P 2 |
| - average | XXX | XXX | XXX | XXX | P 3 |
| - capital | XXX | XXX | XXX | XXX | ... |
| Shipbuilding | XXX | XXX | XXX | XXX | ... |
| mechanical engineering | XXX | XXX | XXX | XXX | ... |
| Other works | XXX | XXX | XXX | XXX | P n |
| TOTAL: | XXXX | XXXX | XXXX | XXXX | 320000 |
NOTE: The symbol XXXX or XXXX in the table refers to any number of man-hours. Nomenclature - the annual number of manufactured products, expressed in items.
Shipyard nomenclature
| Name | Quantity, pcs. |
| Ship repair: | |
| Passenger ship (PT) pr. 544 | 4 |
| PT pr. R - 51 | 8 |
| Cargo-passenger ship (GPT) pr. 305 | 2 |
| Dredger pr. 324 A | 4 |
| Towing ship (BT) pr. 911 V | 8 |
| ................... | ............ |
| Shipbuilding: | |
| barge project 942 A | 5 |
| barge pr. R - 14 A | 4 |
| BT pr. 1741 A | 1 |
| Engineering: | |
| winch LRS - 500 | 25 |
| etc. | ... |
For serial and small-scale production the annual product release program is not carried out all at once, but is divided into batches. Lot of details- this is the number of parts that are simultaneously launched into production. The breakdown into batches is explained by the fact that the customer often does not need the entire annual program at once, but needs a uniform flow of ordered products. Another factor is the reduction of work in progress: if it is necessary to assemble, for example, 1000 gearboxes, then the production of 1000 shafts No. 1 will not allow to assemble a single gearbox until at least one set is available.
The batch size of parts affects:
1. On process performance and his cost price due to the share of preparatory and final work time (T p.z.) for one product
t piece-to. = t pcs + T p.z. / n , (8.1)
where t piece-to. - piece-calculation time for a technological operation; t pcs - piece time for a technological operation; n- lot size of parts. The larger the batch size, the less piece-calculation time for the technological operation.
Preparatory-final time (T p.z.) - this is the time to perform work to prepare for the processing of parts at the workplace. This time includes:
1. time to receive a task from the foreman of the site (operational map with a sketch of the part and a description of the processing sequence);
2. time to get acquainted with the task;
3. time to get the necessary cutting and measuring tools, technological equipment (for example, a three-jaw self-centering or four-jaw non-self-centering chuck, a drilling chuck, a rigid or rotating center, a fixed or movable steady rest, a collet chuck with a set of collets, etc.) in the tool room pantry;
4. time for the delivery of the required blanks to the workplace (with non-centralized delivery of blanks);
5. time to install the required devices on the machine and align them;
6. time to install the required cutting tools on the machine, adjust to the required dimensions when processing two to three test parts (when processing a batch of parts);
7. time for the delivery of processed parts;
8. time for cleaning the machine from chips;
9. time to remove attachments and cutting tools from the machine (if not used in the next work shift);
10. time to check in fixtures, cutting and measuring tools (which will not be used on the next work shift) in the tool pantry.
Typically, the preparatory and final time is from 10 to 40 minutes, depending on the accuracy and complexity of processing, the complexity of aligning fixtures and adjusting to dimensions.
2. For the area of the workshop: The larger the batch, the more storage space is required.
3. On product cost through unfinished production: the larger the batch, the larger the work in progress, the higher the cost of production. The greater the cost of materials and semi-finished products, the greater the impact of work in progress on the cost of production.
The batch size of parts is calculated by the formula
n = N´ f/F , (8.2)
where n– batch size of parts, pcs.; N- the annual program for the manufacture of all parts of all groups, pieces; F- the number of working days in a year; f- the number of days of stock to store parts before assembly.
In this way, N/F– daily release program, pcs. Number of days of stock to hold parts before assembly f= 2…12. The larger the size of the part (more space required for storage), the more expensive the material and manufacturing (more money required, more to give back on loans), the less the number of days of stock to store parts before assembly is set ( f= 2..5). On practice f= 0.5…60 days.
For mass production characteristic is the start stroke and exhaust stroke
t h =F d m/N zap, (8.3)
where t h - start cycle, F d m- the actual fund of equipment time for the corresponding shift work m, N zap - a program for launching blanks.
The release cycle is defined in the same way.
t in =F d m/N vyp, (8.4)
where N issue - program for the release of parts.
Due to the inevitable appearance of marriage (from 0.05% to 3%), the launch program should be more program issue for the corresponding share.
GOST 14.004-83
Group T00
INTERSTATE STANDARD
TECHNOLOGICAL PREPARATION OF PRODUCTION
Terms and definitions of basic concepts
Technological preparation of production. Terms and definitions of basic concepts
MKS 01.040.03
01.100.50
OKSTU 0003
Introduction date 1983-07-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR State Committee for Standards
2. APPROVED AND INTRODUCED BY Decree of the USSR State Committee for Standards of 09.02.83 N 714
3. This standard complies with ST SEV 2521-80 in terms of paragraphs 1-3, 8-11, 13, 15, 20-24, 28-36, 40, 43, 50
4. REPLACE GOST 14.004-74
5. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
Item number |
|
Introduction, 35-39, 44, 45 |
|
Introduction, 48, 49 |
|
Introduction, 17 |
6. EDITION (February 2009) with Amendments No. 1, 2, approved in February 1987, August 1988 (IUS 5-87, 12-88)
This standard establishes applied in science, technology and production * products of mechanical engineering and instrumentation.
________________
* Including repair.
The terms established by the standard are mandatory for use in all types of documentation, scientific and technical, educational and reference literature.
Items 1-3, 8-11, 13, 15, 20-24, 28-36, 40, 43, 50 of this standard correspond to ST SEV 2521-80.
This standard should be used in conjunction with GOST 3.1109, GOST 23004 and GOST 27782.
There is one standardized term for each concept. The use of terms - synonyms of the standardized term is prohibited. Synonyms that are not allowed for use are given as reference and are designated "Ndp".
For individual standardized terms in the standard, short forms are given as reference, which are allowed to be used in cases that exclude the possibility of their different interpretation.
The established definitions can, if necessary, be changed in the form of presentation, without violating the boundaries of concepts.
The standard contains an alphabetical index of the terms contained in it and an appendix containing the terms and definitions of the scope of work and characteristics of the management of the CCI.
Standardized terms are in bold, their short form is in light, and invalid synonyms are in italics.
(Changed edition, Rev. N 2).
TERMS AND DEFINITIONS OF THE BASIC CONCEPTS OF TECHNOLOGICAL PREPARATION OF PRODUCTION
TERMS AND DEFINITIONS OF THE BASIC CONCEPTS OF TECHNOLOGICAL PREPARATION OF PRODUCTION
Term | Definition |
GENERAL CONCEPTS |
|
1. Technological preparation of production | A set of measures that ensure the technological readiness of production |
2. Technological readiness of production Technological readiness | Availability at the enterprise of complete sets of design and technological documentation and technological equipment necessary for the implementation of a given volume of output with established technical and economic indicators |
3. one system technological preparation production | The system of organization and management of technological preparation of production, regulated state standards |
4. Branch system of technological preparation of production | The system of organization and management of technological preparation, established by industry standards, developed in accordance with state standards ESTPP |
5. | The system for organizing and managing the technological preparation of production, established by the regulatory and technical documentation of the enterprise in accordance with state standards ESTPP and industry standards |
COMPONENTS, PROPERTIES AND CHARACTERISTICS OF TECHNOLOGICAL PREPARATION OF PRODUCTION |
|
CCI function | A set of tasks for the technological preparation of production, united by a common goal of their solution |
The task of the CCI | Completed part of the work as part of a specific function of technological preparation of production |
Organization of the CCI | Formation of the structure of technological preparation of production and preparation of information, mathematical and technical support necessary to perform the functions of technological preparation of production |
Office of the Chamber of Commerce and Industry | A set of actions to ensure the functioning of the technological preparation of production |
CCI term | The time interval from the beginning to the end of the technological preparation of the production of the product |
ENGINEERING PRODUCTION AND ITS CHARACTERISTICS |
|
11. Machine-building production | Production with the predominant use of mechanical engineering technology methods in the production of products |
12. Production structure | The composition of the shops and services of the enterprise, indicating the links between them |
13. Production area | A group of jobs organized according to the principles: subject, technological or subject-technological |
14. Shop | Set of production sites |
15. Workplace | The elementary unit of the structure of the enterprise, where the performers of the work are located, serviced technological equipment, part of the conveyor, for a limited time tooling and objects of labor. Note. The definition of the workplace is given in relation to engineering production. Job definition applied in other industries National economy, established by GOST 19605 |
16. | The ratio of the number of all different technological operations performed or to be performed during the month to the number of jobs |
17. | |
18. Type of production | Notes: 1. There are types of production: single, serial, mass |
36. release rhythm | |
37. | |
38. Technological equipment | |
39. Technological equipment | |
(Changed edition, Rev. N 1, 2). |
|
PROPERTIES AND CHARACTERISTICS OF OBJECTS OF LABOR |
|
40. Product series | All products manufactured according to design and technological documentation without changing its designation |
41. Product design continuity constructive continuity | The set of properties of the product, characterized by the unity of the repeatability in it of the components related to the products of this classification group, and the applicability of new components, due to its functional purpose |
42. Technological continuity of the product Technological continuity | The set of product properties that characterize the unity of applicability and repeatability of technological methods for the implementation of component parts and their structural elements relating to products of this classification group |
PROCESSES AND OPERATIONS |
|
43. Manufacturing process | The totality of all the actions of people and tools necessary for this enterprise for the manufacture and repair of products |
44. Technological process | |
44a. Basic technological process | Technological process the highest category, taken as the initial one in the development of a specific technological process. Note. The highest category includes technological processes that, in terms of their performance, correspond to the best world and domestic achievements or surpass them. |
45. Technological operation | |
46. Technological route | The sequence of passage of the workpiece of a part or assembly unit through the shops and production sites enterprises during the technological process of manufacturing or repair. Note. There are intershop and intrashop technological routes |
47. rassehovka | Development of intershop technological routes for all components of the product |
48. | |
49. | |
50. technological discipline | Compliance with the exact compliance of the technological process of manufacturing or repairing the product with the requirements of technological and design documentation |
INDEX OF TERMS
Process automation | |
Type of production | |
Readiness of production technological | |
Technological readiness | |
Discipline technological | |
The task of technological preparation of production | |
The task of the CCI | |
Transaction consolidation ratio | |
Material utilization rate | |
Technological route | |
Production scale | |
Place of work | |
Mechanization of the technological process | |
Production capacity | |
Technological equipment | |
Issue volume | |
Output volume | |
Technological operation | |
Organization of technological preparation of production | |
Organization of the CCI | |
Technological equipment | |
production batch | |
Technological production preparation | |
Continuity of the product is constructive | |
Constructive continuity | |
Product continuity technological | |
Technological continuity | |
Release program | |
Product release program | |
Auxiliary production | |
Group production | |
Single production | |
Individual production | |
Tool production | |
Mass production | |
Engineering production | |
Pilot production | |
Main production | |
Line production | |
Serial production | |
Production steady | |
Manufacturing process | |
Technological process | |
Basic technological process | |
rassehovka | |
release rhythm | |
Product series | |
The system of technological preparation of production is unified | |
Industrial production preparation system | |
The system of technological preparation of production of the enterprise | |
Technological equipment | |
Term of technological preparation of production | |
CCI term | |
Production structure | |
Release stroke | |
Type of production | |
Management of technological preparation of production | |
Office of the Chamber of Commerce and Industry | |
Production area | |
Function of technological preparation of production | |
CCI function | |
Shop | |
Production cycle |
(Changed edition, Rev. N 1).
APPENDIX (reference). TERMS AND DEFINITIONS OF THE COMPOSITION OF WORK AND CHARACTERISTICS OF THE MANAGEMENT OF THE CCI
APPENDIX
Reference
Term | Definition |
1. Planning of technological preparation of production Chamber of Commerce Planning | Establishment of the nomenclature and values of indicators of technological preparation of production, characterizing the quality of the performance of its functions |
2. Accounting for technological preparation of production Accounting for Chamber of Commerce and Industry | Collection and processing of information on the state of technological preparation for the production of a product at a certain point in time |
3. Control of technological preparation of production CCI control | Identification of deviations of actual values of indicators of technological preparation of production of a product from planned values of indicators |
4. Regulation of technological preparation of production CCI regulation | Making decisions to eliminate deviations in the values of indicators of technological preparation for the production of a product from the planned values of indicators and their implementation |
5. Labor intensity of technological preparation of production Labor intensity of the Chamber of Commerce and Industry | Labor costs for the implementation of technological preparation of production from the receipt of initial documents for the development and production of the product until the technological readiness of the enterprise |
Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
Technological preparation system
production:
Collection of national standards. -
M.: Standartinform, 2009
Production is called in-line, in which, in the steady state, all operations are simultaneously performed on an orderly moving set of similar products, except perhaps for a small number of them with incompletely loaded jobs.
In-line production in its most perfect form has a set of properties that correspond to the maximum extent to the principles of rational organization of production. These main properties are as follows.
Strict rhythmic production of products. Rhythm release- is the number of products produced per unit of time. Rhythm is the production of products with a constant rhythm over time.
Release stroke- This is the period of time after which the release of one or the same number of products of a certain type is periodically produced.
There are options for in-line production, in which, in principle, there is no rhythmic release at the level of individual items. Strict regularity of repetition of all flow operations - this property consists in the fact that all operations of mass production of a certain type of products are repeated at strictly fixed intervals, creating the prerequisites for the rhythmic release of these products.
Specialization of each workplace in the performance of one operation for the manufacture of products of a certain type.
Strict proportionality in the duration of the execution of all operations in-line production.
Strict continuity of the movement of each product through all operations of mass production.
Straightness of production. The location of all jobs in a strict sequence of technological operations in-line production. However, in a number of cases, for certain reasons, it is not possible to achieve complete straightness in the arrangement of workplaces, and returns and loops occur in the movement of products.
Types of production lines.
production line - This is a separate set of functionally interconnected workplaces, where the in-line production of products of one or several types is carried out.
According to the nomenclature of products assigned to submarines, there are:
One-subject submarines, each of which is specialized in the production of products of the same type
Multi-subject submarines, on each of which products of several types are simultaneously or sequentially manufactured, similar in design or technology for their processing or assembly.
According to the nature of the passage of products through all operations of the production process, there are:
Continuous production lines, on which the products are continuous, i.e. without interoperative decubitions, go through all operations of their processing or assembly
Discontinuous production lines, which have interoperative beds, i.e. discontinuity in processing or assembly of products.
By the nature of the tact, they distinguish:
Production lines with a regulated cycle, in which the cycle is set forcibly with the help of conveyors, light or sound signaling.
Production lines with free tact, on which the performance of operations and the transfer of products from one operation to another can be performed with slight deviations from the established settlement cycle.
Depending on the order of processing on them, products of various types are divided into:
Multi-subject production lines with sequential-batch alternation of batches of products of various types, in which each type of product is processed exclusively for a certain period, and the processing of various types of products is carried out in successive alternating batches. On lines of this type, it is necessary to rationally organize the transition from the production of products of one type to the production of another:
at the same time, assembly of new types of products is stopped at all workplaces of the production line. The advantage is the absence of loss of working time, however, this requires the creation of a backlog of products of each type at each workplace, which are in the stage of readiness that corresponds to the operation performed at this workplace.
products of a new type are launched on the production line until the assembly of a batch of products of the previous type is completed, and the maximum of two possible cycles for the old and new types of products is set on the production line during the transition period. However, during the transitional period, downtime of workers is possible at those workplaces where products are assembled with a lower required tact than that currently set.
group production lines, which are characterized by simultaneous processing on the production line of batches of products of several types.
