Chassis: The role of the chassis is to support and install the automobile engine and its various components and assemblies to form the overall shape of the automobile, and to receive the power of the engine to make the automobile move and ensure normal driving. The chassis is composed of four parts: drive train, driving train, steering train and brake train.
Introduction
The drive train is generally composed of clutches, transmissions, universal drives, final reducers, differentials and half shafts.
1. The function of the drive train
The power from the car engine is transmitted to the drive wheels by the drive train. The transmission system has functions such as deceleration, speed change, reverse, power interruption, inter-wheel differential and inter-axle differential. It works in conjunction with the engine to ensure the normal driving of the car under various operating conditions and has good power and Economical.
2. The type and composition of the drive train
The transmission system can be divided into mechanical transmission, hydraulic transmission, hydraulic transmission, electric transmission, etc. according to different energy transmission methods.
Driving Department
The driving system consists of the car's frame, axle, wheels (note) and suspension.
The frame, axles, wheels and suspension of the car form the driving system. The functions of the driving system are:
Accept the power of the drive train and generate traction through the action of the drive wheels and the road surface to make the car run normally;
bear the total weight of the car and the ground reaction force;
Reduces the impact of uneven roads on the body, attenuates the vibration of the car during driving, and maintains the smoothness of driving;
Cooperates with the steering system to ensure the stability of the car's handling.
Introduction to steering system
The special mechanism on the car to change or restore its driving direction is called the car steering system.
Basic composition of steering system
(1) Steering control mechanism It is mainly composed of steering wheel, steering shaft, steering column and so on.
(2) Steering device A mechanism that changes 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 operating force. The steering gear is generally fixed on the car frame or body, and the steering control force generally changes the transmission direction after passing through the steering gear.
(3) Steering transmission mechanism A mechanism that transmits the force and motion output by the steering gear to the wheels (knuckles), and deflects the left and right wheels according to a certain relationship.
Steering system type and working principle
According to different steering energy sources, the steering system can be divided into two categories: mechanical steering system and power steering system.
Brake system introduction
A series of special devices on the car to make the outside world (mainly the road surface) exert a certain force on some parts of the car (mainly the wheels), so as to perform a certain degree of forced braking, are collectively called the braking system. Its function is to make the driving car decelerate or even stop according to the driver's requirements; to make the parked car stable under various road conditions (including on the slope); to maintain the speed of the car driving downhill stable.
Only the external forces acting on the car in the direction opposite to the driving direction of the car can brake the car, and the magnitude of these external forces are random and uncontrollable, so a series of special devices must be installed on the car to achieve The above function.
Category:
(1) According to the function of the braking system
Brake systems can be divided into service brake systems, parking brake systems, emergency brake systems and auxiliary brake systems. The brake system used to reduce the speed of a running car or even stop is called a service brake system; the brake system used to make a parked car stay in place is called a parking brake system; When the service brake system fails, the brake system that ensures that the car can still decelerate or stop is called an emergency brake system; during the driving process, the auxiliary service brake system reduces the speed or maintains the speed stable, but the vehicle cannot be emergency The braking system for braking is called the auxiliary braking system. Among the above brake systems, the service brake system and the parking brake system are required for every car.
(2) Press brake to operate energy
The braking system can be divided into human braking system, dynamic braking system and servo braking system. A braking system that uses the driver’s body as the sole braking energy source is called a human brake system; a system that completely relies on potential energy in the form of air pressure or hydraulic pressure converted from the power of the engine is called a dynamic brake system; both The braking system for braking by human power and engine power is called the servo braking system or power-assisted braking system.
(3) According to the transmission method of braking energy
Brake systems can be divided into mechanical, hydraulic, pneumatic, electromagnetic, etc. At the same time, the two braking systems that adopt the energy upload method are called combined braking systems.
The moving system is generally composed of two main parts: brake control mechanism and brake.
(1) Brake control mechanism
Generate braking action, control braking effect and transfer braking energy to various parts of the brake, such as 2, 3, 4, 6 in the figure, 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 tendency of the vehicle. The brakes commonly used in automobiles use friction between the fixed element and the working surface of the rotating element to generate a braking torque, which is called a friction brake. It has two structural types: drum brake and disc brake.
