Automobile suspension is a very important system for automobile suspension system.

It not only affects the comfort of the car (ride), but also affects other

Adoption and other attributes, as well as the stability of the attachment.

Have a significant impact on performance, each suspension is made of elasticity.

Components (buffers), facing the body (transmission and stabilization), and

As a shock absorber. However, not all.

Suspension must have three components. As long as we can play a role

Three.

Vehicle maintenance network 1, flight classification

1.

Non-independent suspension: one on both sides of the wheel.

Bus-train-bridge and train-bridge are connected by frame.

This kind of suspension has simple structure and reliable power-but it is composed of two wheels

Impact and vibration interact. But also because of its quality.

Non-serious flight suspension has poor cushioning performance and large vibration.

The greater the impact force of a moving car. Suspension is usually used for

Trucks, buses and many other ordinary vehicles. (2) independence

Suspension: each person passes through a set of wheels installed on the body or

Suspension axle, off-axis, fixed in the middle

Frame or body; In this way, the suspension on both sides of the wheel is impacted

Household image, but due to the quality of non-flight ratio; Buffer with force

Shock absorption capacity, ride comfort. Indicators are better than

Non-independent suspension, but complicated suspension structure, but it

And the drive axle, the steering system becomes complicated. Such use

Suspend the following two types of vehicles. Cars, buses and

Passenger car. The ride comfort can be improved, and when driving at high speed,

A car with improved stability.

Off-road vehicles, military vehicles and

Mining vehicle. In this case of no right to speak, we can

Ensure that all wheels are in contact on the ground to enhance stability and

Drive this attached car and have a ride.

2. Flexible

Leaf spring with meta model (1): long-range multi-core and

Curvature ranges from composite plates. After being installed at both ends

A natural upward curve. In addition to the leaf spring with buffer, there is also one

A certain degree of shock absorption, vertical layout also has guiding force,

Non-independent suspension uses most leaf springs, so it is very flexible

Assembly, saving guide device and shock absorber, simple structure. (2)

Coil spring: the only cushion for multi-vehicle independent suspension. In ...

Without damping force and mass function, it must also be equipped.

Special shock absorber and guide device. (3) Oil-gas spring: a kind of flexibility

Medium as gas and liquid as power medium, which not only has a good buffering effect.

Capacity, but also has the function of shock absorption and frame.

Height control also applies to the use of heavy vehicles.

A bus. (4), torsion bar spring; Will be manufactured under torsion bar spring.

One end is fixed on the frame, and the other end is connected by an arm.

To the wheel, and the torsion bar in the wheel is used to defeat the torsion deformation.

It plays a buffering role and is suitable for independent suspension.

3.

Using shock absorber tube shock absorber, the amount of oil used is small.

The function of reducing vibration energy consumption. Shock absorber and upper body

The lower end of the frame is connected with the axle. most

The stroke can achieve dual function and compression impact.

Absorber.

4. Device-oriented:

Flexibility in independent suspension components, most of which can only

When transmitting vertical load but not vertical and horizontal load, you must

Become an independent device-oriented As mentioned above, under the arm and vertically, horizontally

Stabilizer, wait.

5.

Non-independent suspension: The front and rear of the truck are not independent.

Suspension bridge, some vehicles, such as buses and cars, etc.

The bridge is also a dependent suspension. Each sedan chair consists of

Hoisting two independent non-vertical arrangements

Leaf spring The leaf spring is fixed in the middle of the train bridge, and

The front end is hinged with the frame or the car body, and the rear end passes through the frame or the car body.

Use a skateboard for hanging ear hinges or connections. The top of the frame has a

The shock absorber is then connected with the lower end of the next school shaft. Rear part of truck

Axles, etc. without shock absorbers.

6.

Many types of independent suspension, coil spring as a flexible use.

Component. The torsion bar spring of independent suspension is also separated.

Torque cup is divided into longitudinal torque and transverse torque. Although many

The advantages of independent suspension, but the car will turn to the system.

The structure of the traveling part and the traveling bridge is complicated.

Key words:

The quality of engine structure directly affects the performance of the engine.

Motor vehicle performance.

First, fuel is used in different ways.

According to the category of engine fuel, it can be divided into gasoline engine and engine.

There are two types of diesel engines.

1

. Network motor maintenance, gasoline engine is small in size and light in weight.

Light weight and low price; Good start, maximum power at high speed; Work in ...

Low vibration and noise; Suitable for small and medium-sized cars

Especially the use of high-speed cars. Gasoline deflagration due to restrictions

The compression ratio should not be too high, and the thermal efficiency and economy are not good.

Such as diesel. Gasoline is a mixed gas, which mainly exists in the form of pipeline.

Into the cylinder, compressed to near the end of spark plug ignition. this

The driver enters the cylinder by controlling the accelerator pedal.

Gas mixture to control the load on the engine, called volume.

Supervision. The fuel supply system and ignition system of a gasoline engine are gasoline engines.

The rate of failure is higher. Emissions from gasoline engines

Harmful substances of carbon monoxide, carbon compounds and nitrogen.

Oxides are better than diesel, and so on, but with current electronic control.

Fuel injection system and other exhaust gas purification devices, which have

Greatly improved. In addition, the gasoline engine

The torque characteristic is very suitable for automobile use, and can be remarkable.

Reduce the labor intensity of drivers.

2.

Diesel and gasoline engines, diesel engines are bulky, heavy, expensive and poor in starting.

Especially at low temperature; The vibration and noise during work are relatively large; be easy to

Black smoke comes out when overloaded. The characteristics of diesel oil are:

1)

There is no deflagration, and there is no need for restriction.

Diesel oil spontaneously ignites and the compression ratio of diesel engine is high. hot

Efficiency and economy are definitely better than gasoline engines.

2)

The same power, the torque of the diesel engine, the maximum power at low speed, suitable for

The use of trucks.

3)

It is a mixed form inside the cylinder of diesel engine, and there is no intake throttle, which

The air intake resistance is small. Drivers have accelerated the adoption of fuel.

The injection control panel changes the engine load, which is called regulation.

Quality, because there is no lack of oxygen, hydrocarbon emissions and

Carbon monoxide content is lower than gasoline.

4)

In the absence of an ignition system and the failure of the fuel supply device.

Low interest rates. Therefore, gasoline engines have fewer failures than diesel engines.

5)

The torque characteristic of diesel engine is not suitable for automobile driving cycle.

Yes, mobile booths are frequently used, which increases the labor force of pilots.

Strength. Main diesel engines used in medium and heavy vehicles.

Second, the number of engine cylinders and

Arrangement of engine cylinder displacement equal to working volume

And ...

raise

The number of cylinders in the engine will not only increase the capacity, but also improve

The output power of the engine can make the engine run smoothly.

Reduce noise and vibration. Modern cars have adopted multi-cylinder engines.

Minicars, small trucks, buses and cars with engines of more than 3 cylinders

Engines with more than 4 cylinders but less than medium size; Medium-sized trucks,

Large cars and buses have engines of more than 6 cylinders; Heavy truck universal

6-8 cylinders. Single-row multi-cylinder inline 6-cylinder engine

Mode; 8-cylinder V engine for calibration; Some cars are trying to

Reduce the engine height and shorten the length, and adopt V6 and V8 layout. mini-car

Use a three-cylinder engine, the most inclined way. The in-line engine has a simple structure.

And cheap. The disadvantage is that the higher the engine height, the longer the time.

Length. More of a way. V-type engine has low height and short length, but

The structure is complex, the price is expensive, and it is suitable for large scale.

Engine. The cylinder block of water-cooled engine adopts integral casting. Use a small engine

Aluminum alloy material, large multi-engine for cast iron. cylinder

The head bolt is used to fix the cushion block on the plane, and also constitutes a

Close the cylinder combustion chamber, intake and exhaust, install the valve, and

Spark plug valve and so on.

Third,

petrolic

Fuel supply 1, fuel supply system Fuel supply for carburetor gasoline engine

Carburetors are mainly divided into direct injection type and fuel injection type.

The working principle of the oil device is:

Engine operation when outside air enters.

The cylinder under the suction air filter enters the cylinder through filtration.

When the air flows through the pipe section, the resistance increases slightly

Speed and pressure caused the vacuum to drop. Floating in

Gasoline enters the car from the main air inlet under the action of vacuum.

Nozzle, the gas sprayed by high-speed airflow is dispersed into fog,

It is called fogging. Then evaporate the space in the form of oil and oil film.

Evaporation, and the air duct has been mixed with the air mixture entering the cylinder.

In order to achieve economy, air braking is also used for main oil loading.

The main nozzle is aimed at the indoor air, and is opened along with several schedules.

Around the through hole and the air in the same room. When the throttle valve is opened

The air hole is gradually enlarged and gradually connected with the air. not only

The vacuum is reduced to dilute the mixture, and the main air nozzle also

It is beneficial to the atomization of gasoline. 2. Electronic fuel control

The carburetor oil supply device of that injection oil supply system has a simple structure,

Reliable, cheap and easy to maintain. But the biggest drawback is that it can't

The concentration of the mixture is precisely controlled, resulting in incompleteness

Combustion, discharge of harmful components, does not meet the strict requirements.

Requirements of environmental protection today. In addition, due to

The existence of pipes increases the air resistance. morever

The gasoline in the cylinder is unevenly distributed, which is easy to produce ice accumulation and bubbles.

And so on. In order to solve these problems, 80 electronically controlled fuel.

The application of injection system in automobile engines is more and more extensive.

More.

Electronically

Advantages of controlled fuel injection system: electronically controlled fuel.

Injection system (EFI) has the following advantages:

1.

No matter what conditions, the engine can

Accurately control the concentration of mixed gas to make gasoline burn.

I'm completely full. This greatly reduces the emission of harmful components.

Material, but also has excellent economy of internal combustion engine.

2.

Centralized control of supply, ignition temperature, etc. can be carried out to facilitate work.

The engine performance is improved, the engine power output is increased, and the fuel is reduced.

Consumption.

3.

The engine can always run stably under various conditions.

Let all car drivers pass according to normal requirements.

4. In the absence of pipes, a small stream of air

Resist. At the same time, it is difficult to produce relatives and distribute them.

Uniform cylinders, and so on. Disadvantages of fuel injection system

It is a complex and high-cost structure and difficult to repair.

Classification of electronically controlled fuel injection system;

1) is divided into two categories: road traffic density and road speed by detecting air quality.

2) By means of fuel injection, the following two methods are adopted.

Category. According to the position of injection, enter the intake manifold connection.

The intake manifold part (SPI) and the air injection part (MPI) are two air injection parts,

Also known as single-point and multi-point jet.

MPI is

The widely used way at present. MPI is currently at

Way. Gasoline ignition system The ignition system of gasoline engine includes

Generally divided into three categories: contact ignition system and electronic ignition system.

Computer controlled ignition system.

Automobile suspension system is a very important system in automobile suspension system. It not only affects the comfort of riding, but also has a significant impact on the stability and other performance of accessories. The elastic element (spring) of each suspension consists of the frame (for stabilizing) and the shock absorber (for damping). However, not all suspensions have to have three parts. As long as we can play three roles. Automobile maintenance and suspension classification:

Non-independent suspension: the wheels on both sides are installed on an integral axle, and the wheels and the axle are connected to the car body through the frame. However, this suspension is simple, reliable and easy to manufacture, but it is affected by the impact of two wheels and vibrating wheels. It is widely used in trucks. However, the performance of the shock absorber is not good. The greater the vibration of the car, the more serious the impact, so this suspension is usually used in ordinary vehicles such as trucks and buses.

Independent suspension: all components are installed or suspended on the frame through wheels on both sides, and disconnected axles are adopted. The wheels installed with this damping system are not easy to fly in weightlessness, and the bumper with strong damping ability provides a comfortable ride. If the position of one wheel relative to the frame (or body) changes, the other wheel will not be affected. This kind of suspension is widely used in cars and passenger cars because of its complex structure, good body stability and high-speed driving. The above indicators are better than dependent suspension, but the more complicated the suspension structure, the more complicated the drive axle and steering system. There are two types of traffic workers who use this suspension:

1 passenger cars, such as cars and buses, can improve ride comfort and stability when driving at high speed.

Mining vehicle. Off-road vehicle, military vehicle, mining vehicle. When the road conditions are bad, it can ensure that all the wheels touch the ground, improve the stability, avoid the ups and downs of the car and give full play to the speed of the car.

Elastic element type: 1 leaf spring: it is a composite plate composed of several rectangular steel plates, which is arc-shaped. Installed at both ends of the natural upward curve. In addition, the leaf spring plays a role in damping and transmitting vertical load through the shock absorber to a certain extent. In dependent suspension and guide mechanisms, leaf springs are also used as elastic elements and as simple structures of shock absorbers.

② spiral spring; It only buffers the independent suspension of multiple vehicles. In the absence of damping force and mass function, there must also be special shock absorbers and guiding devices.

Oil-gas spring: oil and high-pressure gas are used as elastic materials, which not only has good shock absorption ability, but also absorbs impact. It can provide better adjustment function under the same conditions and is suitable for heavy vehicles and buses.

Torsion bar spring: a torsion bar spring used for automobile frames and wheels, one end of which is fixed on the frame and the other end is connected with the wheel. When the wheel jumps up and down, the torsion bar distorts and the vibration energy is absorbed by torsional elasticity, which is suitable for independent suspension system.

3. Use the shock absorber cylinder, and use engine oil to cut off the energy loss caused by vibration. The upper end of the shock absorber is connected with the underframe and the lower end is connected with the axle. The shock absorber can play a dual role of compression in most strokes.

4. Guiding mechanism: Most elastic elements of independent suspension can only transmit vertical load, but not horizontal load. They must be independent guiding mechanisms. As mentioned above, in the moment arm and vertical and horizontal stabilizers and so on.

5. Non-independent suspension: Non-independent suspension is located at the front and rear of trucks, and the rear axle of some vehicles such as buses and automobiles is also non-independent suspension. Each car consists of two independent non-vertical leaf springs. The leaf spring is fixed in the middle of the axle, and the front and rear end frames or car bodies are connected by ear-hanging hinges or skateboards. The upper frame is connected to the shaft through the lower end of the shock absorber. The rear axle generally has no shock absorber.

6. As an elastic element, coil spring is used in many types of independent suspension. Torsion bar spring

Torque cup two times. For independent suspension, it is divided into longitudinal and transverse torque cups. Although independent suspension has many advantages, cars will improve their systems, drive and pass through more complicated bridge structures.

Key words: the structure and performance of the engine have a direct impact on the performance of the car.

First of all, according to the different fuels used by engines, they are divided into gasoline engines and diesel engines.

1 network car maintenance, gasoline engine is small in size, light in weight and low in price; When running at maximum speed, start it well; Low vibration and noise during operation, suitable for small and medium-sized cars, especially high-speed cars. Due to the limitation of deflagration, gasoline engines cannot have too high compression ratio and thermal efficiency, and are not as economical as diesel engines. Gasoline is a mixture that enters the main gas pipe in the cylinder and ignites when it is compressed to the spark plug near the bottom. Traditionally, when the driver steps on the accelerator, the mixed gas enters the cylinder to control the load of the engine. The fuel supply system and ignition system of gasoline engine account for a high proportion of gasoline engine failures. Although gasoline engines emit more harmful substances such as carbon monoxide, carbon compounds and nitrogen oxides than diesel, the current electronically controlled fuel injection system and other tail gas purification devices have been greatly improved. But compared with the current electronically controlled fuel injection system and other exhaust gas purification devices, it has been greatly improved. In addition, the torque characteristics of gasoline engines are very suitable for automobiles, which can greatly reduce the labor intensity of drivers.

2. Diesel engines and gasoline engines. Diesel engines are large in size, heavy in weight, high in price, poor in starting (especially at low temperature), and have great vibration and noise during operation; There is black smoke and it is easy to overload. The diesel engine is characterized in that:

1) has no deflagration limit, but diesel needs spontaneous combustion, so the compression ratio of diesel engine is very high. Thermal efficiency and economy are better than gasoline engines.

2) The diesel engine has the same power, large torque and high maximum power, and is suitable for trucks.

3) The cylinder of diesel engine is mixed gas, and there is no intake throttle and small resistance intake pipe. Driver. Drivers speed up the use of fuel injection control panel, and by changing the engine load, as a quality adjustment, because there is no lack of oxygen, hydrocarbon and carbon monoxide emissions are lower than gasoline.

4) Because there is no ignition system, the failure rate of oil supply equipment is low. So it is not lower than gasoline engine.

5) The torque characteristic of diesel engine is not suitable for the demand of automobile driving cycle, and the frequently used mobile booth is suitable for the increase of pilot's labor intensity. Mainly suitable for medium and heavy vehicles.

Second, the displacement of the engine block and the engine block are the same.

Therefore, increasing the number of cylinders of the engine can not only increase the capacity and improve the output power of the engine, but also make the engine run smoothly and reduce noise and vibration. Hyundai Motor Company adopted a multi-cylinder engine. Minicars have more than 3-cylinder engines, minivans, buses and medium-sized engines have more than 4-cylinder engines; Medium-sized trucks, large cars, buses and engines with more than 6 cylinders; Heavy trucks generally have 6-8 cylinders. 6-cylinder single-row multi-cylinder mode, 8-cylinder V-type inline engine, some cars, in order to reduce the engine height and shorten the length, install V6 engine and V8 engine type. Minicars use three-cylinder engines, most of which are inclined. In-line engines are simple and cheap. The disadvantage is that the height and length of the engine are high. This is a method.

V-type engine is low in height and short in length, but complex in structure and expensive, so it is suitable for large engines.

The cylinder block of water-cooled engine adopts integral casting. Small engines are made of aluminum alloy, while large engines are made of cast iron.

Cylinder head bolt is a fixed block used in aircraft, which not only forms a closed cylinder combustion chamber, but also enters the exhaust pipe, valve and spark plug.

Third, the fuel supply of the gasoline engine is 1, and the carburetor of the fuel supply system.

The working principle of gasoline engine fuel entering carburetor and injector;

When the engine is working, outside air is sucked into the air filter and enters the cylinder through the filter. When air flows through the pipeline, the pressure decreases due to the small growth rate, resulting in vacuum.