Nature provides man a negligible number of objects that can be used directly, without the application of human labor. Therefore, a person has almost always to labor costs, so that, by a qualitative transformation, to adapt natural objects to meet their needs.
A qualitative change in the objects of nature performed by man, is called the technological process (TP). The word "technology" is derived from two Greek words: techne – art, science, craft and logos – the doctrine, thus the doctrine of the craft. Currently, the concept is given the value of knowledge about the means, the ways, the patterns and scientific principles of manufacturing processes (machining, stamping, Assembly, etc.) that is the subject of the study course.
Mechanical engineering is the branch of science dealing with the study of the laws operating in the process of manufacturing the machines, with the aim of using these patterns to ensure the required quality and the lowest cost production them in a timely manner.
From the total set of technologies owned by the state, depends on the efficiency of production in the country as a whole, labor productivity in all sectors of the economy.
The manufacturing of cars starts from the moment when raw materials start to give geometrical parameters and physical-mechanical properties required for the machine, i.e. with the production of blanks of details and concludes with a test machine. In such broad areas as mechanical engineering finds application in many different physical entities and the necessary equipment of processing, processing and combination of materials and semi-finished products: different types of casting, processing pressure, explosion, cutting, electrochemical machining, chemical and heat treatment, welding, brazing, Assembly, surface coatings, etc. All of these processes are studied in the academic subjects in relation to engineering technology are basic.
The aircraft engine (ADS) is a sub sector of the aviation industry, providing aircraft and helicopters of the traction means from the weight, resource, and economic characteristics that affect the efficiency and profitability of operation of the fleet of civil aviation and performance of military aviation.
ADS refers to the average of exact mechanical engineering, which features:
- Medium-size and overall dimensions of the product.
for small engines the most diameter is 500mm.;
for medium-sized engines up to 1000 mm diameter.;
for larger engines transport aircraft – 3000mm.;
- High precision parts and products.
The requirement of high reliability of aircraft engines and assemblies primarily associated with trouble-free operation. (Out of the total number of failures of aircraft and helicopters and 70% the fault of the engines, and 40% of them the fault of the aggregates.) Therefore, the requirements to accuracy and quality of processing involve not only the surfaces of the pairing, but also of available surfaces.
The mating surface of the engine are at the level of 6th class and in assemblies 5,6-og quality. The accuracy of the main parts of the turbines and shafts 8,9 are not lower on quality.
The roughness of the engine parts in the joint areas of reaches Ra0,01мкм, and the average roughness Ra2,5um. Some details of the aggregates have a surface roughness Ra0,008.
- The complexity of the forms and concoctent details.
The specific gravity of a gas turbine engine in 30, 40 times less than that of a car engine.
- Extensive use of expensive materials difficult to machine.
- A large variety of applied methods of treatment.
- Relatively frequent change of production facilities.
Typical terms of sustainable production engines:
for military aircraft...4 to 8 years.
for use in civil aircraft 10...15 years.
Each aircraft factory produced simultaneously from 3-5 to 15-20 types of engines.
All of these requirements are provided with the appropriate level of organization of the production process and quality development and debugging of technological process (TP).
The production process is a set of actions performed to transform materials and supplies into the product. The production process comprises:
the preparation of the means of production;
the organization of maintenance jobs;
receipt and storage of materials and supplies;
all stages of manufacturing, Assembly and testing of products;
transport, technical control and sales.
TP is part of the production process, ensuring production of parts.