What is the difference between manual brakes and valve brakes for large trucks?

The handbrake of large trucks used to be mechanical, there was a brake disc between the gearbox and the transmission shaft, and now it is basically a broken air brake, acting on the rear wheels, and the rear wheels are locked when the air pressure is not enough, and the air pressure can only be lifted when the brake reaches a certain level.

The handbrake is a purely mechanical brake, which only acts on the front wheels and is generally used for parking; Air brakes rely on high-pressure air to push the piston to provide power to the brakes, which has an effect on the front and rear wheels at the same time, but it must be running for a certain period of time before enough high-pressure gas can be stored.

Due to the large inertia of the truck in driving, it is more suitable for air brake.

Air brake is to use gas as the driving medium, when the air pressure of the vehicle gas storage and irrigation reaches the pressure value required for braking, step on the brake pedal brake, the braking sensitivity is high and the response is fast, the pressure generated by the brake shoe is large, and the truck is more suitable due to the inertia in driving.

The air brake used by the car is easy to make the vehicle nod when braking, causing the instability of the vehicle braking and reducing the comfort of the passengers, and there are potential safety hazards to the vehicle and passengers. It is more suitable for trucks and passenger cars with large carrying weight.

Brake tips for big trucks.

1. Long-distance braking.

The braking inertia of large trucks is relatively large, long-distance braking is a braking technology that drivers need to learn, long-distance braking needs to visually measure the distance in advance, and then release the accelerator, according to the distance on the brakes, which can make the brakes more stable, and at the same time there will be no uncomfortable feeling, safety will also be guaranteed.

2. Stop for two brakes.

If you keep stepping on the brakes until the car stops, there will be a relatively large sense of impact before the car stops, so when the vehicle is about to stop, release the brakes, and then step on the brakes, so that the vehicle will be relatively stable and relatively safe.

3. Emergency braking:

Emergency braking is also more common when driving, if there is no ABS anti-lock braking function on the car, do not step on the end of the emergency braking, step on it twice, so as to avoid the situation of tail flicking out of control when braking suddenly, if there is an ABS car, you can step on it deeper when braking suddenly, but you should also pay attention to safety to avoid causing greater accidents.

Large trucks have such a phenomenon is very common, that is, in the process of driving, suddenly there will be a big deflation sound, under normal circumstances, this is the air brake of the large truck in action, we see the big truck in life, the braking method is basically the air brake, so why do large trucks love the air brake?

The air brake system is composed of an air compressor, an air reservoir, a brake master cylinder, four brake cylinders, a front wheel quick release valve, a rear wheel relay valve, an adjustment back, an S cam, a brake shoe and a brake drum.

The role of the air compressor is to produce high-pressure gases, which are stored in gas reservoirs. The air reservoir is connected to the brake master cylinder by a gas pipe. The brake master cylinder is divided into upper and lower air chambers, the rear wheel is controlled by the upper air chamber, and the front wheel is controlled by the lower air chamber.

When it's time to brake, the driver presses the brake pedal. In order to facilitate the driver's control of the direction, the upper air chamber is opened first, and the high-pressure gas is transmitted to the relay valve, which then pushes out the piston inside to control the brakes of the two rear wheels. At the same time, another air chamber is opened, and high-pressure gas enters the quick release valve, which controls the brakes of the two front wheels.

When the gas enters the brake cylinder, the pushrod of the brake cylinder will be pushed forward, and the pusher will control the adjustment of the back rotation, and then control the S-type cam to rotate at an angle. At this time, the S-type cam will stretch the brake shoes open, and the diameter will become larger, which is the contact friction between it and the brake drum, and then make the truck brake.

When the brakes are completed, the driver releases the pedals, the air chamber closes, and the quick-release valve and relay valve return to position under the action of the spring. The gas from the brake cylinder is released, the pushrod returns, and the brake ends. That's why we hear a loud deflation sound when the big trucks brake.

Compared to oil brakes, air brakes respond faster because they don't require a circuit like oil brakes, just vent the gas directly to the outside. As long as the cylinder is big enough, the exhaust speed is fast enough. In addition, the air pressure generated by the air brake is very high, which can output a large amount of braking force, which can brake the truck faster.

Secondly, for large trucks, the hydraulic brake is often unstable, and there is a danger of oil blockage.

Hello. The principle of eight-wheel air brake is that the air brake is composed of: air compressor, at least two air reservoirs, a brake master cylinder, a quick release valve of the front wheel, and a relay valve of the rear wheel. It is composed of four brake cylinders, four adjustment backs, four cams, eight brake shoes and four brake ancient brakes.

Working principle: The air pump is driven by the engine to compress the air into high-pressure gas and store it in the gas cylinder. One of the reservoirs can be connected to the brake master cylinder through the line.

The brake master cylinder is divided into two air chambers, the upper air chamber controls the rear wheels, and the lower air chamber controls the front wheels. When the driver presses the brake pedal, the upper gas is first turned on and the high-pressure gas from the reservoir is transmitted to the relay valve. The control piston of the relay valve is pushed out, and the gas from the other reservoir can be connected through the relay valve and the two rear brake cylinders.

The push rod of the brake cylinder is pushed forward, and the cam is eccentric by adjusting the back cam to rotate at an angle, and the brake shoe is propped up and the brake is turned at the same time to achieve the effect of braking.

When the upper chamber of the brake master cylinder is opened, the lower chamber is also opened, and the high-pressure gas enters the quick-release valve, which is then distributed to the brake cylinders of the two front wheels. The latter is the same. When the driver releases the brake pedal, the upper and lower air chambers close.

The pistons of the quick-entry valve of the front wheel and the relay valve of the rear wheel return to position under the action of the spring. The front and rear brake cylinders are connected with the air chamber and the atmosphere, the push rod is returned, and the brake is ended.

The braking system of the large truck is composed of air compressor, air reservoir, brake pump, quick release valve, relay valve, brake cylinder, adjusting back, cam, brake shoe and other components, when braking, the air pump will compress the air into high-pressure gas through the transmission of engine power, and finally stored in the air reservoir, one of the air reservoirs is connected to the master cylinder, and the brake master cylinder is divided into two air chambers, the upper air chamber controls the rear wheel, and the lower air chamber controls the front wheel.

When the driver steps on the brake, the upper air chamber will be opened first, and the high-pressure gas of the gas reservoir will be transmitted to the relay valve, and the control piston of the relay valve will be pushed out, and the gas in the air reservoir can be connected with the brake cylinder, and the push rod of the brake cylinder will be pushed forward, and then the car can achieve the effect of braking.

The upper chamber of the brake master cylinder will be opened at the same time, the lower chamber will also be opened, the high-pressure gas enters the quick release valve, and then the brake cylinder of the two front wheels is distributed, generally the rear wheels brake first, the front wheels brake again, in general, the air brake of the truck is very complex, and the internal structure is also very complex.

Hello 1, there are two possibilities for truck brakes, one is not good with foot brakes, hand brakes are not good, that is, the brake clearance is too large or the friction coefficient between the brake pads and the brake pot is not enough, adjust the brakes to replace the brake pads. The second foot brake can be hand brake, but not. Kelingbu pretended to be that the spring in the brake cylinder was broken; 2. In addition, the difference between the special car oil brake, air brake and ruler stove air brake is as follows

The characteristics of oil brakes: long braking stop distance, slow response, but simple structure, easy maintenance, cheap oil brakes are mainly used in small trucks and motorcycles. Above; 3. However, now there is a trend of popularization of air brakes, and some small trucks have also begun to be equipped with air brakes.

The main reason is the customer's demand for truck driving brake safety: short braking distance, fast response, complex structure, high maintenance cost, high purchase cost, air brake and air brake are used in medium and large trucks, buses, semi-trailers and concrete mixer trucks and other heavy-duty vehicles.

Essentially, it is a kind of assistance.