Development of a mechanism for overturning the platform of the car on three sides - diploma

Contents

Task

Summary

Introduction

Design Part

1 Justification of selected vehicle structure

1.1 Classification and scope of dump trucks

1.2 Layout of dump trucks

1.3 Platform Designs and Characteristics

2 Calculation of dump trucks

2.1 Calculation tasks and methods

2.2 Calculation of weight characteristics of dump truck

3 Justification of the selected structure of the assembly

3.1 Platform rollover mechanism

3.2 Hydraulic lifting mechanism

3.3 Telescopic lift operation

3.4 Design of lifting mechanism units

3.5 Analysis and evaluation of different lifting structures

body devices

4 Calculation of platform tilting mechanism

4.1 Determination of optimal kinematic and power parameters of lifting mechanism

4.2 Calculation of hydraulic cylinder

4.3 Determination of oil pump feed of tilting mechanism

4.4 Determination of hydraulic system oil tank capacity

5 Process Part

5.1 Part Assignment

5.2 Selection of procurement method

5.3 Workability of part design

5.4 Development of the part manufacturing process route

5.5 Calculation of allowances

5.6 Modes of cutting modes

5.7 Selection of cutting tool

6Economic part

7 Occupational safety

Conclusion

List of literature

Specifications

Summary

The diploma project contains an analysis of various overturning mechanisms of platforms, with tripartite unloading, both foreign and domestic structures that have shown themselves well in practice. There is a calculation of the technical characteristics and structures of the tilting mechanism on three sides for a car with a lifting capacity of 1 ton. The purpose of the calculation is to determine the forces and moments acting in the tilting mechanism, durability and reliability of the structure. Calculation of hydraulic system providing platform lifting, in particular power take-off box, hydraulic pump and oil tank, was carried out. The main element of the tilting mechanism of the telescopic hydraulic cylinder has been developed. Strength calculations of all elements of the hydraulic cylinder were carried out. Process of power take-off gear manufacturing is developed in process part. The initial data for the calculation of the rollover mechanism are determined in the technical assignment of the car analogue, which indicates: type of car, its purpose, condition of operation, lifting capacity, maximum speed, maximum climb to be overcome, type of engine and transmission, wheel formula.

Introduction

Road transport is widely used in all sectors of the national economy. Road transport has the following tasks: to increase the efficiency of the use of vehicles, and primarily by improving the structure of the car fleet.

The technical level of the car, the compliance of its design with the requirements of operation directly affect the productivity of transport work. Trucks carry a wide variety of goods, which differ in physical properties, in particular density, size, packaging...

With the development of road transport, stable cargo flows of homogeneous goods arose, as a result of which in many cases it turned out to be economically feasible to adapt a car for mass systematic transportation, the so-called specialized cars appeared. The use of specialized cars and road trains increases the safety of goods, makes it possible to facilitate and fully mechanize loading and unloading operations, and thereby significantly increase labor productivity and reduce the cost of road transport. The most common type of specialized trucks are dump trucks adapted for mass transportation of bulk and bulk cargo.

In this diploma project, a dump truck is being developed on the basis of a low-capacity off-road car UAZ3303. The car has a very successful chassis design, a well-combined wheel formula and layout. On the basis of UAZ3303, many specialized cars have already been created: water carriers, tow trucks, snowplows, self-loaders...

A dump truck based on UAZ3303 wakes up a number of advantages over the existing model range of dump trucks: Economy, high maneuverability, cross-country ability. This allows you to use the dump truck both in cramped urban conditions and in hard-to-reach rural areas.

The main area of ​ ​ application should be agriculture and small-scale construction facilities.

Installing a lifting device on the dump truck with the ability to roll over the platform in three directions will expand the field of application, as well as improve a number of qualities: it will increase the accuracy and speed of unloading.

Cars with such characteristics are currently absent in the market of our country.

5.2 Selection of procurement method

The blank for the cylindrical gear wheel is selected in the form of a stamping with a punched hole, obtained on stamping hammers with allowances of 3-4 mm. Accuracy of blanks obtained on punching hammers corresponds to class 9. Stamping slopes: external to 3˚, and internal to 7˚. In a stamping blank, the metal structure is more uniform, so that the part is stronger. Metal is better used in forming and its consumption is reduced. The production process of stamping is faster compared to other methods of producing blanks, requires a less skilled labor force and its cost is much lower.

Hot volumetric stamping can be carried out on hammers, horizontal forging machines (MCC), stamping presses and forging rollers. Hammer stamping is used in mass production and mass production. The preform of the desired configuration is mostly obtained by sequential processing in several streams made in the same die.

Increased efficiency of equipment and reduced labour intensity of forming process with small weight of blanks is achieved due to sequential forming. The workpiece is pre-processed on rolling machines or forging machines, and then on hammers in multi-piece dies. Accuracy for stamping blanks is determined by GOST 750555.

5.3 Workability of part design

One of the factors that significantly affects the nature of technological processes is the processability of the design of the product and its corresponding parts.

When designing a part, it is necessary to meet not only the operational requirements, but also the requirements of the most rational and economical manufacture of the product. This is the principle of processability of the design.

The less labor and cost of manufacturing the product, the more technologically it is. Thus, the main criterion for evaluating the processability of the design is the labor intensity and cost of the product.

The process design of the part shall include:

a) the widest possible use of the part;

b) creating a part of the most rational shape with easily accessible surfaces for processing and sufficient rigidity in order to reduce the labor intensity and cost of machining the part (the necessary rigidity of the part allows it to be processed on machines with the most productive cutting modes);

c) the presence of convenient basing surfaces on the part or the ability to create auxiliary (technological) bases in the form of bosses, belts, etc.

d) the most rational method of obtaining a workpiece for a part (forging) with dimensions and shapes as close as possible to the finished part, i.e. providing the highest material utilization factor and the least labor input for machining;

The processability of the workpiece design should not only take into account the maximum rationalization of machining, but also the simplification of the manufacturing processes of the workpiece itself.

Since gears are very common parts in the automobile and tractor industry, we develop a mass type of production in which, with a sufficiently large number of identical products, they are manufactured by continuously performing the same constantly repeating operations at workplaces. We need to reduce production costs as much as possible and harmonize operations to increase production speed and efficiency.

6 Economic part

At the present stage of economic development, the role of transport is growing, on the activities of which the efficiency of all sectors of the national economy depends. An integral part of the unified transport system is motor transport, which takes part in production, carrying out the transportation of labor and labor, plays an important role in the socio-economic and cultural relationship of the country. The main production unit is a road transport company.

6.1 Development and shifts in the location of the automotive industry in the 20th century

As in many other countries, in Russia the automotive industry was developed in developed engineering centers (Yaroslavl, Nizhny Novgorod, Moscow), where mainly small-scale production of cars for the "top" was established. After the revolution, a ZIL plant was built in Moscow, which was originally conceived as a plant specializing in the production of trucks, since it was they that the country needed, in particular, to raise agriculture and motorize the army. But one ZIL could not provide the whole country with trucks. Therefore, to provide the country with trucks more fully, under the able leadership of Stalin and Ford, the GAZ plant was erected in record time. The country is more or less emerging from the crisis, the city needs vehicles, the production of cars at the KIM plant begins.

The main role in the shift in the placement of the automotive industry was played by the Great Patriotic War. Since the Germans bombed, it is decided to partially transfer automobile plants to the eastern part of Russia, in order to ensure the uninterrupted production of cars, in particular, ZIL was transferred part to MIASS (Now UralAZ), and part to Ulyanovsk (UAZ). At that time, spare parts, in particular forged and stamped, were also made by the Chelyabinsk Forge and Press Equipment Plant. He carried out the production of carburetors, radiators and other units of power, cooling and lubrication systems at the Shadrinsky Auto Unit Plant.

Throughout the post-war years, the automotive industry of the Russian Federation has increased both its output and its scientific and technical potential, constantly reducing the gap in the technical level between domestic machines and the best foreign analogues.

However, the general unstable economic and political situation that has developed in the country in recent years has led first to a slowdown in growth, and in 1991-1994 - to a significant decrease in the production of automotive equipment, the volume of research and development work. This problem has become especially acute in the research institutes of the industry: they have almost completely stopped research and development of promising conceptual machines, their nodes and systems, which, of course, will affect the technical level of our cars in the near future.

The main reasons for this situation are a significant reduction in state funding for scientific research, as well as the disinterest of enterprises to invest in long-term projects. There was a third reason: a certain confusion of the leadership of research and development organizations, their inability to look for new forms of work and organization of their activities. True, recently, many scientific and production organizations, institutes and factory design units, together with newly created state and commercial structures, have begun to adapt to new, market conditions. Proof of this is the resumption in 1993 of work on the creation of programs for the development of the automotive industry in the Russian Federation and several other CIS states, the development of bus construction, etc.

6.2 Place and importance of the automotive industry in the economy of the Republic of Kazakhstan

The state of affairs in the domestic automotive industry is currently unstable in all spheres of public life, especially in industrial production in the whole country. According to the report, it is not yet possible to slow down the decline in production this year. Overall, industrial production declined by 17.6% in the first nine months of 1995.

The rapid increase in prices due to their liberalisation in 1992 caused the insolvency of enterprises, led to a lack of working capital, restraining the production process and destabilizing their financial situation. There is a sharp decline in investment activity, the curtailment of long-term construction programs. The deep decline in business activity is evidenced, for example, by the fact that out of 393 launch facilities of the automotive industry funded by the federal budget, only three were put into operation and partial commissioning of capacities was carried out at three facilities.

In the automotive industry, as in all engineering, centrifugal trends in relations between traditional partners are increasing, and cooperative ties between enterprises, which have been divided by the borders of newly formed independent states, are collapsing.

The following groups of factors are distinguished: natural - quantitative reserves and qualitative composition of natural resources, mining and geological and other conditions for their extraction and use, climatic, hydrogeological, orographic conditions, etc.; environmental - conservation and constructive measures for lean use of natural resources and ensuring healthy living and working conditions for the population; Technical advances and possible state of the art and technology; socio-demographic - the availability of labor resources, the state of social infrastructure; economic - economic, geographical and transport position, cost, capital and operating costs, construction time, production efficiency, purpose and quality of products, territorial economic ties, etc.

The location of the automotive industry is not affected by raw materials and fuel and energy resources, poorly affected by areas of consumption of finished products, and labor resources have a decisive influence.

Conclusion

The diploma project developed a mechanism for tipping the platform to three sides, for the creation of which the best designs of foreign and domestic analogues were analyzed.

By calculating and analyzing the selected design of the lifting device with a telescopic hydraulic cylinder, it can be concluded that this design and its parameters fully meet the requirements for lifting devices of a truck with a lifting capacity of 1 ton. This design allows you to expand the scope of application of this car and increase competitiveness in the market in the field of low-tonnage cars.

When designing a dump truck, modern mechanical engineering technologies were used, which made it possible to increase the technical characteristics of the car and reduce the cost of production.