In any mechanical assembly shop, the master performs the role of the main specialist who monitors the production. To date, this site can operate according to three principles for the production of parts. It can be mass, serial or single production.
Mass production
If the mechanical assembly shop operates as a site with mass production, this means that batches of parts and series of products will be manufactured here, which will be regularly repeated after a certain period of time. A feature of mass production in this workshop is its multi-nomenclature. A characteristic feature of this parameter is the repeated execution of the same operation at the workplace. As for the products that a workshop of this type can produce, this includes studs, caps and cylinder liners, lever pushers, and parts belonging to the connecting rod group.
All parts that are produced by a serial mechanical assembly shop can be used to assemble devices such as internal combustion engines, metal cutting machines, compressors, pumps. It is worth paying attention to such a technological feature of this section as the nomenclature, size of the parts to be produced, the complexity of manufacturing each part. Depending on all these parameters, mass production in the mechanical assembly shop is divided into small-batch, medium-batch, and large-batch.
Other types of production in the workshop
If we talk, for example, about small-scale production, then in its technological parameters it very much resembles a single production. As for the equipment, universal types are used, as well as a normal working universal measuring tool. Using this type of product manufacturing, in a mechanical assembly shop, it is possible to manufacture suspensions, crankshafts, cylinder blocks, oil-type pumps and for pumping fuel.
As for single production, it is multi-nomenclature, as well as serial. Using this method of organizing a section of a mechanical assembly shop, it is possible to manufacture parts and components for marine diesel engines. A distinctive feature of this type of production is a large product range with a small volume of production. In workshops of this type, both universal and special equipment is used. If we talk about the necessary qualifications of workers, then it must be no lower than average to work in such conditions.
The last type is the mass production of any products. Everything is quite simple here. A characteristic feature of such a scheme of work is the release of the same type of product according to the same drawings, over a long period of time. As for the performance of any operations at the workplace, one or two procedures are performed at each of them. As equipment, special and specialized machines are used. The main preference is given to high-speed machines.
Workshop composition
As for the structure or composition, the composition includes 21 sites. The mechanical assembly shop also consists of such additional workshops as the assembly-testing and procurement-press shops. As a basis for the organization of the workflow, specialization is adopted on the basis of unification of the creation of specialized workshops.
The technological process in the mechanical assembly shop includes 114 production lines and mechanized sections. Seven fully automatic lines are also used here. Among them there are lines for the automatic processing of cylinder covers, for example.
Machinery assembly equipment includes a minimum of 2469 pieces of equipment for metal cutting. To process the manufactured basic parts, up to 650 units of foreign-made equipment can also be used.
The principle of organization of the workshop
To date, there are two principles used to organize this type of workshop.
The first option is independent mechanical and assembly shops. The second version of the organization is the combined mechanical assembly sites. In addition, the organization passes on such grounds as nodal, technical, mixed.
If we talk about the first sign, then its essence lies in the fact that each section of the workshop is assigned a certain number of parts that belong to the same type or are used to create one node. In this case, the organization applies subject specialization. Depending on the design of the product, as well as on the specialization of processing in the workshop, a nodal assembly is also provided. It is important to note here that if there is more than one mechanical assembly shop at one plant, then the introduction of a general assembly into the structure of the site is mandatory. Such a principle of production organization is possible only if the volumes of work are able to fully load the available equipment.
The second option is to equip the site on a technological basis. All manufactured parts are grouped. In one group are combined those products and units that are similar in size and also have a similar manufacturing process. To apply this method of organization is relevant only if the plant is engaged in small-scale or single-piece manufacturing of parts and assemblies. In other words, in the event that it is not possible to fully load the existing equipment.
The last option is a mixed type. Everything is quite simple here. This means that part of the workshops works on a nodal basis, and the other part, for example, a blacksmith and a foundry, works on a technological basis. Most of all industrial enterprises in all sectors work on this principle.
Signs of varieties of shops
To date, there are four features that are basic to determine whether a workshop belongs to one of the types.
- The first and main one is, of course, serial production.
- An important role is played by the method of manufacturing parts and assemblies.
- The number of machines installed and in operation is also important.
- An indirect, but still very important feature is the maximum mass of the workpieces.
If we talk about serial production, then it is determined by the coefficient Kc. The seriality coefficient is a numerical characteristic of the number of operations that are performed at the same workplace. Thus, small-scale production is characterized by a Kc value of 20-40. Serial and medium series plots have a coefficient of 5-20. Large-scale ones have a coefficient of only 3-5. The most large-scale production, that is, mass production, differs Ks in 1-3.
Production Methods
When planning a mechanical assembly shop, it is important to consider the method of manufacturing products. Currently, two methods are used - in-line and non-in-line production.
The flow method is a form of organization of production, which implies that all operations will be performed within a strictly established and agreed upon time between all workshops. In addition, all procedures must be repeated after a certain period of time with an exact time interval between them. As for jobs in this case, all of them belong to a specialized type, and they are arranged so that they correspond to the course of the technological process. Using this form of organization of production contributes to the fact that all the principles that bring the efficiency of the workshop to the maximum level are embodied. Naturally, the flow form of organization has become most widespread in large-scale and mass production. In small batch or single flow form is also used, but very rarely.
It is worth paying attention to the fact that such a structure of the mechanical assembly shop will help to simplify the work with the material flow and manage it as much as possible. This is facilitated by the fact that there is a high level of sophistication of the issue in terms of streamlining the movement of objects of labor in space and time. It is also important to add that this layout of the mechanical assembly shop is confidently following the path of full automation of the process. Automatic lines, machine tools with numerical software, lines containing software-controlled equipment, and frequent use of microprocessor technology are being introduced.
Non-flow organization
If we talk about the application of this type of organization of production, then most often it is observed in a single, small-batch and medium-sized production of parts and assemblies. It differs in that the movement of objects of labor in space is disordered, but their movement in time can be predicted. This is also the greatest difficulty in organizing a non-continuous form of production, if we compare it with a continuous one. It is necessary to put in order the chaotic movement of objects of labor in space. It is necessary to reduce all production flows into a single technological route, where the same units and parts will be manufactured.
An important role is played by the scheme of technological processes. It is a document in which the sequence of passing one part across all workshops is indicated, and inside the workshops - over all technological operations. In addition, it is necessary to indicate on the diagram all data on equipment, equipment and material standards.
Classification of workshops by machine type
The machine assembly shop of a machine-building plant, for example, like any other, can be of the small, medium or large type. This classification depends on the type of machines that are used in it.
Small or light workshop type is characterized by the weight of the equipment up to 0.2 tons. On average, the weight of machines increases to two tons. Heavy types of workshops are divided into three groups, as well as especially heavy ones. The first group is distinguished by the weight of machines up to 30 tons. The second group is 75 tons, the third group is 250 tons. A particularly heavy type of workshop contains equipment weighing up to 500 tons.
In this case, the maximum mass of the part that is being processed plays an important role. If we are talking about light engineering, for example, then the heavy weight of the part limits the use of hoisting vehicles.
When designing a mechanical assembly shop for secondary engineering, it is necessary to use devices such as overhead cranes, pneumatic hoists, conveyors. When setting up a workshop for heavy engineering, it is necessary to have bridge jib cranes with a lifting capacity of 30 to 250 tons.
Workshop areas
Any mechanical assembly department should include such areas as production and auxiliary ones. In addition, the presence of also domestic and office premises. Power supply of the mechanical assembly shop is carried out using devices installed just in the office premises.
As for the production sites, they are intended to accommodate the basic equipment for the manufacture of parts and assemblies. All sites combine jobs. In this case, jobs are understood as the primary construction unit of the plant where the technological operation is performed. PM, which are interconnected by a vehicle, for example, a conveyor, can be combined into one section. Such small sections are organized according to two criteria: an objective attribute for mass or large-scale production and a technological attribute for small, single and medium-sized production of parts and assemblies.
The workshop also has auxiliary sections. The main purpose of their existence is to ensure the operability of production sites.
Workshop Features
In order for this department of the enterprise to normally perform its main function - the production of parts and assemblies, it is necessary that the services attached to this section work in normal mode.
This workshop has a technical bureau, a planning and distribution bureau, accounting, a mechanic service, etc. The functions of the technical bureau are as follows.
Firstly, they are engaged in calculating the equipment load for the month, quarter and annual plan. Secondly, the same bureau is involved in the implementation of the production processes that are developed by the OGT and OGM. One of the important tasks of this bureau is to control the observance of technological discipline in the workshop. He is engaged in organizing all the necessary documentation for the operation of the workshop, as well as its further content. He is engaged in the organization of work on the available technical information. It performs a rather important function, which is to introduce organizational and technical measures, as well as plans for new mechanization.