Production characteristics
Working hours and time funds
Working hours include the number of working days per year, excluding weekends and holidays, with two shifts per day, because An automated section is being developed. The full calendar annual fund of time shows the number of hours in a year: 24,363 = 8670 hours.
Excluding weekends and holidays, based on a five-day working week of 41 hours, we obtain a nominal time fund FN = 4320 hours.
We take into account equipment downtime for repairs; FD is the actual annual operating time of equipment during 2-shift operation.
FD = 3894 hours.
Determination of the release stroke
To justify the organization production process and determining the type of production, it is necessary to calculate the average production rate - and the average piece time - Tsh.av. manufacturing the product at the main operations.
The release stroke is determined by the formula:
(min/piece) (3.3.1)
where Fd = 3894 hours;
Ng = 20000pcs - annual parts production program;
fs = 3894 60/20000 = 11.7 min/piece
Definition of production type
The type of production can be determined by the numerical value of the operation consolidation coefficient, which is calculated according to GOST 3.11.08-74. Approximately, the type of production can be determined by the value of the coefficient - Ks
where Tsht.sr is the average piece production time of a product, determined according to the data of the current technical process.
Tsh.sr. = 71.43/17 = 4.2 min.
Kzo =11.6/4.2=2.7
1< Кс?10 - крупносерийное производство
Analysis of the manufacturability of the design of the “Drive shaft” part
Manufacturability is a property of a product, according to which the design of the part must correspond to the use of the most advanced processing or assembly methods during manufacturing.
Rational machine designs that provide the necessary operational requirements cannot be created without taking into account the labor and material intensity of their production. Compliance of the machine design with the requirements of labor intensity and material intensity determines the manufacturability of the design. When objectively assessing the manufacturability of the design of machines, their parts and assemblies, a number of positive factors that determine the manufacturability of the design are taken into account.
When objectively assessing the manufacturability of the design of machines, their parts and assemblies, a number of positive factors that determine the manufacturability of the design are taken into account. These include:
The optimal shape of the part, ensuring the production of a workpiece with the smallest allowance and the smallest number of machined surfaces;
Lightest machine weight;
The smallest amount of material used in the construction of machines;
Interchangeability of parts and assemblies with optimal tolerance ranges;
Normalization (standardization) and unification of parts, assemblies and their individual design elements.
The basic requirements for the manufacturability of the design of mechanical engineering parts are set out in the literature.
The design of the part must consist of standard and unified structural elements (CED) or be standard in general. Parts must be made from standard or standardized blanks. The dimensions of the part must have optimal accuracy. The surface roughness must be optimal. The physical, chemical and mechanical properties of the material of the part, its rigidity, shape, dimensions must comply with the requirements of the manufacturing technology (including processes of finishing and strengthening treatment, application of anti-corrosion coatings, etc.), as well as storage and transportation.
The base surface of the part must have optimal accuracy and surface roughness, which ensure the required accuracy of installation, processing and control.
Blanks for the manufacture of parts must be obtained in a rational way, taking into account the material, the specified output volume and the type of production. The method of manufacturing parts must allow the simultaneous production of several parts. The design of the part must ensure the possibility of using standard and standard technological processes for its manufacture.
We will test the manufacturability of the “Drive Shaft” part for manufacturability in accordance with the Methodological Instructions.
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
ISS 01.040.03
01.100.50
OKSTU 0003
Date of introduction 1983-07-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR State Committee for Standards
2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated 02/09/83 N 714
3. This standard corresponds to ST SEV 2521-80 in terms of paragraphs 1-3, 8-11, 13, 15, 20-24, 28-36, 40, 43, 50
4. INSTEAD GOST 14.004-74
5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS
Item number |
|
Introductory part, 35-39, 44, 45 |
|
Introductory part, 48, 49 |
|
Introductory part, 17 |
6. EDITION (February 2009) with Amendments No. 1, 2, approved in February 1987, August 1988 (IUS 5-87, 12-88)
This standard establishes mechanical engineering and instrument making products used in science, technology and production *.
________________
* Including repair.
The terms established by the standard are mandatory for use in all types of documentation, scientific, technical, educational and reference literature.
Clauses 1-3, 8-11, 13, 15, 20-24, 28-36, 40, 43, 50 of this standard correspond to ST SEV 2521-80.
This standard must 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 that are synonyms of a standardized term is prohibited. Synonyms that are unacceptable for use are given as a reference and are designated “NDP”.
For individual standardized terms, the standard provides short forms for reference, which are allowed to be used in cases that exclude the possibility of their different interpretation.
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 it contains and an appendix containing terms and definitions of the scope of work and characteristics of the management of the Chamber of Commerce and Industry.
Standardized terms are in bold, their short forms are in light, and invalid synonyms are in italics.
(Changed edition, Amendment No. 2).
TERMS AND DEFINITIONS OF BASIC CONCEPTS OF TECHNOLOGICAL PREPARATION OF PRODUCTION
TERMS AND DEFINITIONS OF BASIC CONCEPTS OF TECHNOLOGICAL PREPARATION OF PRODUCTION
Term | Definition |
GENERAL CONCEPTS |
|
1. Technological preparation of production | A set of measures to 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 to implement a given volume of product output with established technical and economic indicators |
3. one system technological preparation of production | System of organization and management of technological preparation of production, regulated state standards |
4. Industry system technological preparation of production | The system of organization and management of technological preparation installed industry standards, developed in accordance with state standards of the European Union of Industrialists and Entrepreneurs |
5. | The system for organizing and managing technological preparation of production, established by the regulatory and technical documentation of the enterprise in accordance with state standards of the ECTPP and industry standards |
COMPONENTS, PROPERTIES AND CHARACTERISTICS OF TECHNOLOGICAL PREPARATION OF PRODUCTION |
|
CCI function | Set of tasks for technological training production united by the common goal of solving them |
The task of the Chamber of Commerce and Industry | The completed part of the work included specific function technological preparation of production |
Organization of the Chamber of Commerce and Industry | 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 |
Chamber of Commerce and Industry | A set of actions to ensure the functioning of technological preparation of production |
Chamber of Commerce and Industry term | Time interval from the beginning to the end of technological preparation for the production of a product |
MECHANICAL ENGINEERING PRODUCTION AND ITS CHARACTERISTICS |
|
11. Mechanical engineering production | Production with the predominant use of mechanical engineering technology methods in the production of products |
12. Production structure | The composition of the workshops and services of the enterprise, indicating the connections between them |
13. Production area | A group of jobs organized according to the following principles: subject, technological or subject-technological |
14. Shop | Set of production sites |
15. Workplace | An elementary unit of the enterprise structure, where the performers of the work are located, the service technological equipment, part of the conveyor, equipment and labor items for a limited time. Note. The definition of a workplace is given in relation to mechanical engineering production. The definition of a workplace used in other sectors of the national economy is established by GOST 19605 |
16. | The ratio of the number of all various 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. Rhythm of release | |
37. | |
38. Technological equipment | |
39. Technological equipment | |
(Changed edition, Amendment No. 1, 2). |
|
PROPERTIES AND CHARACTERISTICS OF SUBJECTS OF LABOR |
|
40. Product series | All products manufactured according to design and technological documentation without changing its designation |
41. Constructive continuity of the product Constructive continuity | The set of properties of a product characterized by the unity of repeatability in it components related to 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 producing components and their structural elements related to products of a given classification group |
PROCESSES AND OPERATIONS |
|
43. Manufacturing process | The totality of all actions of people and tools necessary at a given enterprise for the manufacture and repair of products |
44. Technological process | |
44a. Basic technological process | A technological process of the highest category, taken as the initial one when developing a specific technological process. Note. The highest category includes technological processes that, in terms of their performance, correspond to or exceed the best global and domestic achievements |
45. Technological operation | |
46. Technological route | The sequence of passage of a blank part or assembly unit through the workshops and production areas of the enterprise during the technological process of manufacturing or repair. Note. There are inter-shop and intra-shop technological routes |
47. Rastsekhovka | Development of inter-shop technological routes for all components of the product |
48. | |
49. | |
50. Technology discipline | Compliance with the exact compliance of the technological process of manufacturing or repairing the product with the requirements of technological and design documentation |
ALPHABETIC INDEX OF TERMS
Process automation | |
Type of production | |
Technological production readiness | |
Technological readiness | |
Technological discipline | |
The task of technological preparation of production | |
The task of the Chamber of Commerce and Industry | |
Transaction consolidation rate | |
Material utilization rate | |
Technological route | |
Production scale | |
Work place | |
Mechanization of the technological process | |
Production capacity | |
Technological equipment | |
Issue volume | |
Product output volume | |
Technological operation | |
Organization of technological preparation of production | |
Organization of the Chamber of Commerce and Industry | |
Technological equipment | |
Production batch | |
Technological preparation of production | |
Continuity of the product is constructive | |
Continuity is constructive | |
Technological continuity of the product | |
Technological continuity | |
Release program | |
Product release program | |
Auxiliary production | |
Group production | |
Single production | |
Individual production | |
Tool production | |
Mass production | |
Mechanical engineering production | |
Experimental production | |
Main production | |
In-line production | |
Serial production | |
Production is steady | |
Production process | |
Technological process | |
Basic technological process | |
Rastsekhovka | |
Rhythm of release | |
Product series | |
The system of technological preparation of production is unified | |
Industrial technological preparation system for production | |
System of technological preparation of enterprise production | |
Technological equipment | |
Technological preparation period for production | |
Chamber of Commerce and Industry term | |
Production structure | |
Release stroke | |
Type of production | |
Management of technological preparation of production | |
Chamber of Commerce and Industry | |
Production area | |
Function of technological preparation of production | |
CCI function | |
Shop | |
Production cycle |
(Changed edition, Amendment No. 1).
APPENDIX (reference). TERMS AND DEFINITIONS OF WORK AND CHARACTERISTICS OF CCI MANAGEMENT
APPLICATION
Information
Term | Definition |
1. Planning of technological preparation of production CCI planning | Establishment of the nomenclature and values of indicators of technological preparation of production, characterizing the quality of performance of its functions |
2. Accounting for technological preparation of production CCI accounting | Collection and processing of information about the state of technological preparation for the production of a product at a certain point in time |
3. Control of technological preparation of production Control of Chamber of Commerce and Industry | Identification of deviations of the actual values of indicators of technological preparation of product production from the planned values of indicators |
4. Regulation of technological preparation of production Regulation of the Chamber of Commerce and Industry | Making decisions to eliminate deviations in the values of indicators of technological preparation of product production 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 performing technological preparation of production from receiving initial documents for the development and production of a product until the technological readiness of the enterprise |
Electronic document text
prepared by Kodeks JSC and verified against:
official publication
Technological preparation system
production:
Collection of national standards. -
M.: Standartinform, 2009
Mechanical engineering production is characterized by output volume, product release program, and production cycle.
Product output volume- this is the number of products of certain names, standard sizes and designs manufactured or repaired by an enterprise or its division during a planned period of time (month, quarter, year). The volume of output largely determines the principles of constructing the technological process.
The list of manufactured or repaired products established for a given enterprise, indicating the volume of production and deadlines for each item for the planned period of time, is called production program .
Release stroke is the time interval through which products or blanks of a certain name, standard size and design are periodically produced.
Release stroke t, min/piece, is determined by the formula:
t = 60 F d / N,
where F d – actual time fund in the planned period (month, day, shift), h; N – manufacturing program for the same period, pcs.
The actual operating time fund of equipment differs from the nominal (calendar) time fund, since it takes into account the loss of time for equipment repairs.
The actual operating capacity of equipment depending on its complexity and the number of weekends and holidays with a 40-hour work week and when working in two shifts in engineering production ranges from 3911 to 4029...4070 hours. The worker's time fund is about 1820 hours.
Depending on the production capacity and sales opportunities, products at the enterprise are manufactured in various quantities - from single copies to hundreds and thousands of pieces. In this case, all products manufactured according to design and technological documentation without changing it are called product series .
Depending on the breadth of the range, regularity, stability and volume of product output, three main types of production are distinguished: single, serial and mass. Each of these types has its own characteristic features in the organization of labor and in the structure of production and technological processes.
Type of production is a classification category of production, distinguished on the basis of breadth of product range, regularity, stability and volume of production. In contrast to the type of production, the type of production is distinguished based on the method used to manufacture the product. Examples of types of production are foundry, welding, mechanical assembly, etc.
One of the main characteristics of the type of production is transaction consolidation ratio K z.o., which is the ratio of the number of all different technological operations O, performed or to be performed during the month, to the number of jobs P:
With the expansion of the range of manufactured products and a decrease in their quantity, the value of this coefficient increases.
Single production characterized by a small volume of production of identical products, the re-production and repair of which, as a rule, is not provided for. In this case, the technological process of manufacturing products is either not repeated at all, or is repeated at indefinite intervals. Unit production includes, for example, large hydraulic turbines, rolling mills, equipment for chemical and metallurgical plants, unique metal cutting machines, prototypes of machines in various branches of mechanical engineering, etc.
Unit production technology is characterized by the use of universal metal-cutting equipment, which is usually located in workshops according to a group basis, i.e. broken down into sections of turning, milling, grinding machines, etc. Processing is carried out with a standard cutting tool, and control is carried out with a universal measuring tool. A characteristic feature unit production is the concentration of a variety of operations at workplaces. At the same time, one machine often performs complete processing of workpieces of various designs and from various materials. Due to the need for frequent reconfiguration and adjustment of the machine to perform a new operation, the share of the main (technological) time in general structure The standard processing time is relatively small.
The distinctive features of unit production determine relatively low labor productivity and high cost of manufactured products.
Mass production characterized by the manufacture or repair of products in periodically repeating batches. In mass production, products of the same name or the same type in design are manufactured according to drawings that have been tested for manufacturability. Series production products are machines of an established type, produced in significant quantities. These products include, for example, metal-cutting machines, internal combustion engines, pumps, compressors, equipment for the food industry, etc.
Serial production is the most common in general and medium-sized mechanical engineering. In serial production, along with universal equipment, special equipment, automatic and semi-automatic machines, special cutting tools, special measuring instruments and devices are widely used.
In mass production, the average qualification of workers is usually lower than in individual production.
Depending on the number of products in a batch or series and the value of the consolidation coefficient, operations are distinguished small-scale, medium-scale and large-scale production . Such a division is quite conditional for various industries mechanical engineering, since with the same number of machines in a series, but different sizes, complexity and labor intensity, production can be classified as different types. The conventional boundary between the varieties of serial production according to GOST 3.1108-74 is the value of the coefficient of consolidation of operations K z.o. : for small-scale production 20< К з.о < 40, для среднесерийного – 10 < К з.о < 20, а для крупносерийного – 1 < К з.о < 10.
In small-scale production, close to a single unit, the equipment is located mainly by type of machine - a section of lathes, a section of milling machines, etc. Machines can also be located along the technological process if processing is carried out according to a group technological process. Mainly universal means of technological equipment are used. The production batch size is usually several units. In this case, a production batch is usually called objects of labor of the same name and standard size, launched into processing within a certain time interval, with the same preparatory and final time for the operation.
At the initial stage of development of the machining technological process, the batch size of parts can be determined using the following simplified formula:
where N is the number of parts of the same name and size according to the annual product production program;
t – required stock of parts in the warehouse in days; for large parts t=2...3 days; for average t=5 days; for small parts and tools t=10...30 days;
F – the number of working days in a year, is taken to be 305 days with one day off and a working day of 7 hours. and 253 days with two days of rest and a working day of 8 hours.
Conventionally, parts weighing up to 2 kg can be classified as small (or light), parts weighing up to 2 kg can be classified as medium, parts weighing from 2 to 8 kg can be classified as large (or heavy), over 8 kg.
In medium-scale production, usually called serial production, equipment is located in accordance with the sequence of workpiece processing stages. Each piece of equipment is usually assigned several technological operations, which makes it necessary to re-adjust the equipment. The production batch size ranges from several tens to hundreds of parts.
In high-volume, near-volume production, equipment is typically arranged in a process sequence for one or more parts that require the same machining process. If the product production program is not large enough, it is advisable to process workpieces in batches, with sequential operations, i.e. After processing all the blanks of a batch in one operation, this batch is processed in the next operation. After finishing processing on one machine, the workpieces are transported as a whole batch or in parts to another, while Vehicle use roller tables, overhead chain conveyors or robots. Processing of workpieces is carried out on pre-configured machines, within the technological capabilities of which readjustment to perform other operations is permissible.
In large-scale production, as a rule, special devices and special cutting tools are used. Limit gauges (staples, plugs, threaded rings and threaded plugs) and templates are widely used as measuring tools, which make it possible to determine the suitability of processed parts and break them down into size groups depending on the size of the tolerance zone.
Serial production is much more economical than individual production, since equipment is used better, allowances are lower, cutting conditions are higher, jobs are highly specialized, the production cycle, interoperational backlogs and work in progress are significantly reduced, a higher level of production automation, labor productivity increases, sharply decreases labor intensity and cost of products, simplifies production management and labor organization. In this case, the reserve is understood as a production stock of blanks or component parts of the product to ensure the uninterrupted execution of the technological process. This type of production is the most common in general and medium-sized engineering. About 80% of mechanical engineering products are mass-produced.
Mass production characterized by large volumes of production of products that are continuously manufactured or repaired over a long period of time, during which one work operation is performed at most workplaces. Parts are usually made from blanks, the production of which is carried out centrally. The production of non-standard equipment and technological equipment is carried out in a centralized manner. The workshops, which are an independent structural unit, supply them to their consumers.
Mass production is economically feasible when producing a sufficiently large number of products, when all material and labor costs associated with the transition to mass production pay off quickly enough and the cost of the product is lower than in mass production.
Mass production products are products of a narrow range, unified or standard type, produced for wide distribution to consumers. These products include, for example, many brands passenger cars, motorcycles, sewing machines, bicycles, etc.
In mass production, high-performance technological equipment is used - special, specialized and modular machines, multi-spindle automatic and semi-automatic machines, automatic lines. Multi-bladed and stacked special cutting tools, extreme gauges, high-speed control devices and instruments are widely used. Mass production is also characterized by a steady production volume, which, with a significant production program, provides the opportunity to assign operations to specific equipment. At the same time, the production of products is carried out according to the final design and technological documentation.
The most advanced form of organizing mass production is in-line production, characterized by the arrangement of technological equipment in the sequence of operations of the technological process and a certain cycle of product release. The flow form of organizing the technological process requires the same or multiple productivity in all operations. This makes it possible to process workpieces or assemble units without backlogs at strictly defined time intervals equal to the release cycle. Bringing the duration of operations to a specified condition is called synchronization, which in some cases involves the use of additional (duplicate) equipment. For mass production, the coefficient of consolidation of operations K z.o. = 1.
The main element continuous production is the production line on which the workplaces are located.
To transfer the subject of labor from one workplace to another, special vehicles are used.
In a production line, which is the main form of labor organization in continuous production, one technological operation is performed at each workplace, and the equipment is placed along the technological process (along the flow). If the duration of the operation at all workplaces is the same, then work on the line is performed with the continuous transfer of the production object from one workplace to another (continuous flow). It is usually not possible to achieve equality of piece time in all operations. This causes a technologically inevitable difference in equipment loading at work stations on the production line.
With significant output volumes during the synchronization process, the need most often arises to reduce the duration of operations. This is achieved through differentiation and time combination of transitions that are part of technological operations. In mass and large-scale production, if necessary, each of the technological transitions can be separated into a separate operation if the synchronization condition is met.
In a time equal to the production cycle, a unit of product leaves the production line. Labor productivity corresponding to the allocated production site(line, section, workshop), is determined by the rhythm of production. Rhythm of release – This is the number of products or blanks of certain names, standard sizes and designs produced per unit of time. Ensuring a given rhythm of production is the most important task when developing a technological process for mass and large-scale production.
The flow method of work provides a significant reduction (tens of times) in the production cycle, interoperational backlogs and work in progress, the possibility of using high-performance equipment, reducing the labor intensity of manufacturing products, and ease of production management.
Further improvement of flow production led to the creation of automatic lines, on which all operations are carried out at a set pace at workstations equipped with automatic equipment. Transportation of the subject of labor to positions is also carried out automatically.
It should be noted that at one enterprise and even in one workshop one can find a combination of different types of production. Consequently, the type of production of an enterprise or workshop as a whole is determined by the predominant nature of technological processes. Production can be called mass production if most workplaces perform one constantly repeating operation. If the majority of workplaces perform several periodically repeating operations, then such production should be considered serial production. The absence of frequency of repetition of operations at workplaces characterizes unit production.
In addition, each type of production is also characterized by the corresponding accuracy of the initial workpieces, the level of refinement of the design of parts for manufacturability, the level of automation of the process, the degree of detail in the description of the technological process, etc. All this affects the productivity of the process and the cost of manufactured products.
The systematic unification and standardization of mechanical engineering products contributes to the specialization of production. Standardization leads to a narrowing of the range of products with a significant increase in their production program. This allows for the wider use of in-line work methods and production automation.
Production characteristics are reflected in decisions made during technological preparation of production.
For conditions of serial and small-scale production, the annual product production program is not carried out all at once, but is divided into batches. Lot of parts– this is the number of parts 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 requires a uniform supply of ordered products. Another factor is the reduction of work in progress: if, for example, 1000 gearboxes need to be assembled, then the production of 1000 No. 1 shafts will not allow the assembly of a single gearbox until at least one set is available.
The lot size of the parts affects:
1. On process performance and him cost price due to the share of time of preparatory and final work (T p.z.) per product
t pcs. = t pcs + T p.z. / n , (8.1)
Where t pcs. - piece-calculation time for a technological operation; t pcs – piece time for a technological operation; n– batch size of parts. The larger the batch size, the shorter the unit costing time for the technological operation.
Preparatory-final time (T p.z.) is the time for performing work to prepare for the processing of parts at the workplace. This time includes:
1. time to receive the task from the site foreman (operational card with a sketch of the part and a description of the processing sequence);
2. time to familiarize yourself with the task;
3. time to obtain the necessary cutting and measuring tools, technological equipment (for example, a three-jaw self-centering or four-jaw non-self-centering chuck, a drill chuck, a rigid or rotating center, a fixed or movable rest, a collet chuck with a set of collets, etc.) in the tool room pantry;
4. time to deliver the required workpieces to the workplace (in case of non-centralized delivery of workpieces);
5. time to install the required devices on the machine and align them;
6. time to install the required cutting tools on the machine, adjusting to the required dimensions when processing two to three test parts (when processing a batch of parts);
7. time for delivery of processed parts;
8. time to clean the machine from chips;
9. time to remove fixtures and cutting tools from the machine (if they will not be used in the next work shift);
10. time to hand over fixtures, cutting and measuring tools (which will not be used in the next work shift) to the tool storeroom.
Typically, the preparatory and final time ranges 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 size of the workshop: The larger the batch, the more space required for storage.
3. To the cost of production through unfinished production: The larger the batch, the larger the work in progress, the higher the cost of production. The higher the cost of materials and semi-finished products, the greater the impact of work in progress on production costs.
The batch size of parts is calculated using the formula
n = N´ f/f , (8.2)
Where n– batch size of parts, pcs.; N– annual production program for all parts of all groups, pcs.; F– number of working days in a year; f– the number of days of stock for storing parts before assembly.
Thus, N/F– daily graduation program, pcs. Number of days of stock to store parts before assembly f = 2…12. The larger the size of the part (more storage space is required), the more expensive the material and manufacturing (more money is required, more loans are required), the lower the number of days of stock for storing parts before assembly is set ( f = 2..5). On practice f = 0.5...60 days.
For continuous production, the starting cycle and release cycle are characteristic.
t h =F d m/N zap, (8.3)
Where t z – start stroke, F d m– actual equipment time fund for the corresponding work shift m, N zap – program for launching blanks.
The release cycle is determined similarly
t V =F d m/N issue, (8.4)
Where N vyp – part production program.
Due to the inevitable occurrence of defects (from 0.05% to 3%), the launch program must be larger than the release program by the corresponding proportion.
The qualification requirements for workers are low.
Control can be active or passive.
Passive control is carried out after completion of work, and its purpose is to register a marriage.
Active control is carried out during the processing of the workpiece and its purpose is to prevent defects, for example, when a given size is reached, the machine turns off.
In large-scale and mass production, production lines are organized: machines are installed as the technological process progresses, the workpiece moves from machine to machine, either synchronously with the production cycle (direct-flow production), or without following the principle of operation synchronization.
Release stroke
F d – actual annual operating equipment of equipment in 1 shift (F d »2015).
n – number of job changes.
N – annual production volume of products.
60 – conversion factor, hours per minute.
The release cycle is the time between the release or launch into production of two adjacent units of product.
In KS and MS production, synchronization of operations is often used, i.e. their distance is equal to or a multiple of the beat.
A production line with non-synchronized operations is called variable-flow; in this case, a separate operation is provided using the backlog method.
In CC production, the most appropriate is the group form of organizing the technological process.
Its essence lies in the fact that subject-closed areas are created for the production of a group of technologically and structurally similar products. For example, a section of shafts and pulleys.
 |
Structure of technical preparation of production.
Figure 4 - Structure of the Chamber of Commerce and Industry
aimed at developing, preparing for release and releasing a new type of product.
Scientific software aims to conduct research into the possibility of using advanced achievements of natural and applied sciences in a new product.
The design software aims to prepare design documentation for a new product (assembly, installation, instructions). The checkpoint is implemented in the department of the chief designer.
CCI is a set of activities aimed at preparing for the release of a new product.
Initial information – design documentation and production volume.
The first function is testing for manufacturability; its goal is to ensure the technologist is confident in the possibility of manufacturing a product under given production conditions.
Design and manufacture of service stations: the design bureau of equipment and tool production are under the influence of the chief technologist.
Chamber of Commerce and Industry Management. Its functions.
Organization of PP – preparation of materials, components.
4 Production and technological processes and their structure.
To manufacture a machine capable of fulfilling its intended purpose, it is necessary to perform a set of works to transform the source material into parts, Assembly units and products in general.
The entire range of these activities constitutes a complex process.
According to GOST 14003-83, the production process is a set of actions of people and tools necessary at a given enterprise for the manufacture or repair of products.
The production process consists of technological processes: procurement (casting, forging, etc.); mechanical processing, heat treatment, transportation, etc.
A technological process is a part of the production process that contains targeted actions to change or determine the state of the subject of labor.
Definition is a control operation.
 |
Figure 5 – Structure of the technological process.
Technological operations are a complete part of the technological process performed at one workplace.
IN technological process operations are numbered through 5.
For example: 5.10... or 05.10...
Installation is a part of a technological operation performed with constant fastening of the workpiece being processed or the assembly unit being assembled.
In the technological documentation, installations are designated by the letters A, B, etc.
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Figure 6 – Installation designation diagram.
Position - a fixed position occupied by a permanently fixed workpiece together with a device relative to a cutting tool or a stationary piece of equipment to perform a certain part of the operation. Positions in technological documentation are indicated by Roman numerals.
The concept of position is present in operations performed on multi-spindle machines, as well as on machines such as machining centers.
For example, positions for a multi-spindle vertical machine.
Figure 8 – Scheme of workpiece transfer by position
This use of equipment is called dual-index operation.
The operation consists of two settings and 8 positions.
Machines such as machining centers often process body workpieces using rotary tables. This makes it possible to process the workpiece from different sides with one constant fixation. Each side's processing will represent a separate item.
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Figure 9 – Processing 3 faces on the machine.
Technological transition– this is a completed part of a technological operation, characterized by the constancy of the tools and surfaces used under constant technological conditions.
Auxiliary transition- this is a completed part of a technological operation, consisting of human (or equipment) actions not accompanied by a change in shape, size or surface roughness, but necessary to complete a technological transition. For example, install a workpiece, remove it.
Working stroke– a completed part of a technological transition, consisting of a single movement of the tool relative to the surface being processed, accompanied by a change in the shape, size, roughness and other properties of the workpiece.
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Auxiliary move– a completed part of a technological transition, consisting of a single movement of the tool relative to the surface being processed, not accompanied by a change in the shape, size, roughness or properties of the workpiece, but necessary to complete the working stroke.
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