1. Automobile engine: An engine is a machine that can convert other forms of energy into mechanical energy, including internal combustion engines (gasoline engines, etc. ), external combustion engine (Stirling engine, steam engine, etc. ), motor, etc. For example, internal combustion engines usually convert chemical energy into mechanical energy. The engine is suitable for both power generation devices and complete machines including power devices. The engine is mainly composed of cylinder block, cylinder liner, cylinder head and cylinder gasket.
2. Automobile chassis: The role of the chassis is to support and install the automobile engine, its parts and assemblies, form the overall shape of the automobile, accept the power of the engine to make the automobile move, and ensure normal driving. The chassis consists of four parts: transmission system, running system, steering system and braking system.
The transmission system is generally composed of clutch, transmission, universal transmission, main reducer, differential and half shaft.
The driving system consists of a frame, axles, wheels and suspension. The frame, axle, wheel and suspension of an automobile form a drive system, and its functions are:
A, receiving the power of the transmission shaft, and generating traction through the action of the driving wheel and the road surface, so that the automobile can run normally;
B, bear the total weight of the car and the ground reaction force;
C, alleviate the impact of uneven road surface on the car body, attenuate the vibration when the car is driving, and maintain the ride comfort;
D, cooperate with the steering system to ensure vehicle handling stability.
The steering system consists of steering control mechanism, steering gear and steering transmission mechanism.
First, the steering control mechanism is mainly composed of steering wheel, steering shaft and steering column.
B. The steering gear converts the rotation of the steering wheel into the swing of the steering rocker arm or the linear reciprocating motion of the rack shaft, and amplifies the steering control force. The steering gear is generally fixed on the frame or car body, and the steering control force will generally change the transmission direction after passing through the steering gear.
C. The steering transmission mechanism is a mechanism that transmits the force and motion output by the steering gear to the wheels (steering knuckles) and deflects the left and right wheels according to a certain relationship.
According to the different sources of steering energy, automobile steering system can be divided into mechanical steering system and power steering system.
The braking system is generally composed of two main parts: the brake operating mechanism and the brake.
(1) Brake control mechanism
Generate braking effect, control braking effect, and transfer braking energy to all parts of the brake, as well as the brake wheel cylinder and brake pipeline.
(2) Brake
A component that generates a force (braking force) that hinders the movement or movement tendency of a vehicle. The commonly used brake in automobile is called friction brake, which generates braking torque by using the friction between the working surface of fixed element and rotating element. It has two structural forms: drum brake and disc brake.
3. Car body: The car body is installed on the frame of the chassis for drivers and passengers to ride or load goods. The body of a car or bus is generally an integral structure, and the body of a truck is generally composed of a cab and a cargo box. The main function of automobile body is to protect the driver and form a good aerodynamic environment. A good body can not only bring better performance, but also reflect the personality of the owner. Formally speaking, automobile body structure is mainly divided into non-load-bearing type and load-bearing type.
Non-bearing type
Cars with non-load-bearing bodies have rigid frames, which are also called chassis girders. The car body is suspended on the frame and connected by elastic elements. The vibration of the frame is transmitted to the car body through the elastic elements, and most of the vibration is weakened or eliminated. When a collision occurs, the frame can absorb most of the impact force and protect the body when driving on bad roads. Therefore, the car has small deformation, good stability and safety, and low noise inside the car. However, this kind of non-load-bearing car body has large volume, heavy weight, high center of mass and poor stability at high speed.
Load-bearing: A load-bearing car has no rigid frame, but only the front, side wall, rear and floor are strengthened. The body and underframe together form a rigid spatial structure of the body. In addition to the inherent load-bearing function, this kind of load-bearing body also directly bears various loads. This kind of car body has the advantages of large bending and torsion stiffness, small mass, low height, low center of mass, simple assembly and good high-speed driving stability. However, because the road load will be directly transmitted to the car body through the suspension device, the noise and vibration are large.
Semi-load-bearing: There is another body structure between non-load-bearing body and load-bearing body, which is called semi-load-bearing body. Its body and underframe are rigidly connected by welding or bolts, which strengthens a part of underframe and plays a part of frame. For example, the engine and suspension are installed on the reinforced underframe, and the body and underframe become a whole and bear the load together. This form is essentially a load-bearing body structure without a frame. So people usually only divide the automobile body structure into non-load-bearing body and load-bearing body.
4. Electrical equipment: Electrical equipment consists of power supply and electrical equipment. The power supply includes storage battery and generator; Electrical equipment includes the starting system of engine, the ignition system of gasoline engine and other electrical equipment.
Battery is an indispensable part of automobile, which can be divided into traditional lead-acid battery and maintenance-free battery. Because lead-calcium alloy is used as the grid frame of storage battery, the amount of water decomposition and evaporation during charging are low. In addition, the shell adopts a sealed structure, and little sulfuric acid gas is released. Therefore, compared with the traditional battery, it has the advantages of no need to add any liquid and long storage time of the wiring pile.
The automobile generator is the main power supply of the automobile, and its function is to supply power to all electrical equipment (except the starter) and charge the battery when the engine is running normally (above idle speed).
The automobile starting system consists of battery, ignition switch, starting relay and starter.
Ignition system is an important part of gasoline engine, and its performance has great influence on engine power, fuel consumption and exhaust pollution. All devices that can generate electric spark between two electrodes of a spark plug are called engine "ignition system". It usually consists of storage battery, generator, distributor, ignition coil and spark plug.