Four-stroke four-cylinder engine - DBE, Drawings

Contents

Introduction

1. Thermal calculation of the engine

1.1 Fuel

1.2 Working medium parameters

1.3 Inlet parameters

1.4 Calculation of inlet process

1.5 Calculation of compression process

1.6 Calculation of combustion process

1.8 Operating cycle indicators

1.9 Effective engine parameters and parameters

1.10 Main cylinder and engine parameters

1.11 Completion of indicator diagram

2. Heat balance

3. Construction of external speed characteristic of the engine

4. Kinematic calculation of KSM

5. Dynamic engine calculation

6. Engine Balance Analysis

7. Calculation of gas distribution mechanism

7.1 Main dimensions of flow sections in the neck and in the valve

7.2 Main Intake Cam Dimensions

7.3 Flat pusher impact-free cam profiling

7.4 Time-section of valve

7.5 Calculation of valve spring

7.6 Camshaft Calculation

8. Calculation of piston group

8.1 Piston calculation

8.3 Calculation of piston pin

9. Cooling system calculation

9.1 Water Pump Calculation

9.2 Calculation of cooling surface of water radiator

9.3 Fan Calculation

Conclusion

List of literature used

Introduction

The significant growth of all sectors of the national economy requires the movement of a large number of cargo and passengers. High maneuverability, cross-country ability and adaptability to work in various conditions makes the car one of the main means of transporting goods and passengers. Road transport plays an important role in the development of the eastern and non-black-earth regions of our country. The lack of a developed railway network and the limited use of rivers for navigation make the car the main means of transportation in these areas. Road transport in Russia serves all sectors of the national economy and occupies one of the leading places in the unified transport system of the country. Road transport accounts for over 80 per cent of all combined transport modes and more than 70 per cent of passenger traffic. Road transport was created as a result of the development of a new branch of the national economy - the automotive industry, which at the present stage is one of the main links of domestic engineering. The beginning of the creation of the car was laid more than two hundred years ago (the name "car" comes from the Greek word autos - "itself" and Latin mobilis - "mobile"), when they began to make "self-propelled" carts. They first appeared in Russia. In 1752, a Russian self-taught mechanic, a peasant L. Shamshurenkov, created a rather perfect "self-legged stroller" for his time, driven by two people. Later, the Russian inventor I.P. Kulibin created a "scooter trolley" with a pedal drive. With the advent of the steam engine, the creation of self-propelled carriages quickly advanced. In 18691870 J. Quño in France, and a few years later steam cars were built in England. The widespread use of the car as a vehicle begins with the advent of a high-speed internal combustion engine. In 1885, G. Daimler (Germany) built a motorcycle with a gasoline engine, and in 1886, K. Benz - a three-wheeled carriage. Around the same time, cars with internal combustion engines were being created in industrialized countries (France, Great Britain, USA). At the end of the 19th century, the automotive industry arose in a number of countries. In tsarist Russia, attempts were repeatedly made to organize their own engineering. In 1908, car production was organized at the Russian-Baltic Car Building Plant in Riga. For six years, cars were produced here, assembled mainly from imported parts. In total, the plant built 451 cars and a small number of trucks. In 1913, the car fleet in Russia amounted to about 9,000 cars, of which most were foreign-made. After the Great October Socialist Revolution, almost again it was necessary to create the domestic automotive industry. The beginning of the development of the Russian automotive industry dates back to 1924, when the first AMOF15 trucks were built at the AMO plant in Moscow. In the period 19311941. Large-scale and mass production of cars is being created. In 1931, the AMO plant began mass production of trucks. In 1932, the GAZ plant went into operation. In 1940, the Moscow Plant of Small Cars began production of small cars. A little later, the Ural Automobile Plant was created. Over the years of the post-war five-year plans, Kutaisi, Kremenchug, Ulyanovsk, Minsk automobile plants entered into operation. Since the late 1960s, the development of the automotive industry has been characterized by a particularly rapid pace. In 1971, the Volga Automobile Plant named after 50th anniversary of the USSR. In recent years, automotive plants have mastered many examples of modernized and new automotive equipment, including for agriculture, construction, trade, oil and gas and forestry.

Internal combustion engines

Currently, there are a large number of devices using thermal expansion of gases. Such devices include carburetor engines, diesel engines, turbojet engines, etc. Heat engines can be divided into two main groups: 1. External combustion engines - steam engines, steam turbines, Stirling engines, etc. 2. Internal combustion engines. As automotive power plants, internal combustion engines have become most widespread, in which the process of combustion of fuel with the release of heat and its transformation into mechanical work occurs directly in cylinders. Most modern cars have internal combustion engines. The most economical are piston and combined internal combustion engines. They have a fairly long service life, relatively small overall dimensions and weight. The main disadvantage of these engines should be considered the reciprocating movement of the piston, due to the presence of a crank mechanism that complicates the design and limits the possibility of increasing the speed, especially with significant engine sizes. And now a little about the first ICE. The first internal combustion engine (ICE) was created in 1860 by the French engineer Etwen Lenoir, but this machine was still very imperfect. In 1862, the French inventor Bo de Rocha proposed using a four-stroke cycle: 1 in an internal combustion engine. suction; 2. compression; 3. burning and expansion; 4. exhaust. This idea was used by the German inventor N. Otto, who built the first four-stroke internal combustion engine in 1878. The efficiency of such an engine reached 22%, which exceeded the values ​ ​ obtained using all previous types of engines. The rapid spread of ICE in industry, transport, agriculture and stationary energy was due to a number of their positive features. The operation of the internal combustion engine in one cylinder with low losses and a significant temperature difference between the heat source and the refrigerator ensures a high economy of these engines. High efficiency is one of the positive qualities of ICE. Among ICE, diesel is currently such an engine that converts the chemical energy of fuel into mechanical work with the highest efficiency in a wide range of power changes. This quality of diesel engines is especially important, given that the reserves of oil fuels are limited. The positive features of ICE are also that they can be connected to almost any energy consumer. This is due to the wide possibilities of obtaining the corresponding characteristics of the change in power and torque of these engines. The engines in question are successfully used on cars, tractors, agricultural machines, diesel locomotives, ships, power plants, etc., i.e. ICE are well adapted to the consumer. The relatively low initial cost, compactness and small mass of ICE allowed them to be widely used on power plants that are widely used and have small dimensions of the engine compartment. Installations with ICE have great autonomy. Even aircraft with ICE can fly for tens of hours without replenishing fuel. An important positive quality of ICE is the ability to quickly start them in normal conditions. Engines operating at low temperatures are equipped with special devices to facilitate and accelerate start-up. After start-up, the engines can take full load relatively quickly. ICE has a significant braking moment, which is very important when using them in transport installations. The positive quality of diesel engines is the ability of one engine to work on many fuels. So known are the designs of automotive multi-fuel engines, as well as high-power ship engines that operate on various fuels - from diesel to boiler fuel oil.But along with the positive qualities of ICE, they have a number of drawbacks. Among them, limited in comparison with, for example, steam and gas turbines, aggregate power, high noise level, relatively high speed of crankshaft rotation at start-up and impossibility of its direct connection with driving wheels of consumer, toxicity of exhaust gases, reciprocating movement of piston, limiting rotation speed and causing unbalanced inertia forces and moments from them. But it would be impossible to create internal combustion engines, their development and use, if not for the effect of thermal expansion. After all, in the process of thermal expansion, gases heated to a high temperature perform useful work. Due to the rapid combustion of the mixture in the cylinder of the internal combustion engine, the pressure increases sharply, under the influence of which the piston moves in the cylinder. And this is the very necessary technological function, that is, force, the creation of high pressures, which is performed by thermal expansion, and for the sake of which this phenomenon is used in various technologies and in particular in ICE.

Calculation of gas distribution mechanism

For gas exchange in existing automobile and tractor engines, valve mechanisms are used, made mainly according to two design schemes: with an upper and lower arrangement of valves. Currently, most engines have an upper valve arrangement.

When designing a valve mechanism, it is necessary to strive to meet two opposing requirements as much as possible:

1) obtaining maximum flow sections ensuring good filling and cleaning of the cylinder,

and 2) minimizing the weight of the moving valve parts to reduce inertial loads.

From thermal calculation we have :

Cylinder diameter D = 92 mm;

Piston area F = 66 cm2;

Speed at rated power nN=6100 rpm;

Crankshaft angular speed = 638.5 rad/s;

Angular rotation speed of camshaft, which is, = 0.5 * [omega] = 319.25 rad/s

The average piston speed is sa = 15.66 m/s;

Mixture velocity in the seat flow section at maximum lifting of inlet valve vp = 95 m/s;

Pre-opening angle of inlet valve pr = 340;

Lag angle of inlet valve closing pr = 740;

Valve distribution mechanism is upper valve with upper location of camshaft.

Conclusion

The course design presents a designed in-line, four-stroke, four-cylinder automobile piston ICE with a nominal power of 88 kW, a compression ratio of 11, an excess air coefficient of 1, at a crankshaft speed of 6100 rpm.

The following main engine parameters are obtained:

1. Cylinder diameter D = 92 mm.

2. Piston stroke S = 77 mm.

3. Engine displacement V = 2.05 l.

4. Ne Effective Power = 87.5 kW

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