Among all the configurations of the vehicle, the braking system is the most basic safety guarantee. Once the braking system fails, other high-end configurations can only become empty talk. As a saying goes, judging a car's performance is not how fast it can run, but whether it can stop smoothly and safely no matter how fast it runs.

There are many kinds of vehicle braking methods. In addition to the air brake and oil brake, which are commonly seen, there are also wire brake, cut-off air brake, exhaust brake and electromagnetic brake. Today, Darong axle will take stock with you of the common braking methods and their main characteristics on those vehicles.

1. Air brake

Air brake refers to the brake system with compressed air as the medium, which is generally composed of air compressor, brake valve, brake air chamber, air reservoir, air pressure gauge, air pump, pressure spring, safety valve, brake pipeline and other components.

Principle:

Pneumatic drive is used to realize dynamic braking.

When the vehicle stops, the push rod of the brake chamber controls the brake in the braking state under the action of the spring force;

After the vehicle is started, the air pump operates. When the pressure reaches a certain level, the push rod of the brake chamber overcomes the spring force under the action of the air pressure and releases the brake state of the brake, and the vehicle can run;

When braking is required, the brake pedal controls the brake valve to release the pressure of the brake chamber, and the push rod brakes under the action of the spring force.

To put it simply, you can walk with gas, but you can't walk without gas.

advantage:

The air brake has fast reaction speed and strong braking force. The output of braking force is only related to the air pressure in the air reservoir and the valve opening, and has nothing to do with the stepping force. It is not easy to slide in the uphill and downhill road conditions, can stop at high speed with full load, and is not easy to roll over in case of emergency braking.

Disadvantages:

The structure of the air brake is relatively complex, and the installation space is relatively large. In addition, the maintenance and use in the later stage are relatively complex, and the brake wear is obvious. Frequent stepping on the brake pedal during downhill will also lead to insufficient air pressure and brake failure. Some old cars need to idle for a period of time after parking, which is also difficult to solve.

Applicable models:

It is generally used on medium and large vehicles such as trucks and buses.

2. Oil brake

Oil brake refers to the mode of braking through the power of the engine oil pump. The braking force is transmitted through the brake oil to realize the deceleration or stop of the vehicle. It is generally composed of master cylinder, slave cylinder, oil cup and connecting pipeline.

Principle:

Oil brake uses high-density brake oil instead of steel wire. When the owner steps on the brake, the piston and seal cup in the brake master cylinder will be pushed by the brake pedal, and the push rod will act to transfer the brake oil to the piston of each brake cylinder through the oil pipe, and then push the friction plate to rub with the brake drum to achieve the braking effect.

advantage:

The structure is simple, the volume is small, the requirements for installation space are relatively small, the braking force output is relatively soft, the output is as much as the number of steps, it is not easy to lock, the driving comfort is high, the components are small, and the maintenance is convenient.

Disadvantages:

The reaction speed is slightly slow, the braking force is weak, and the oil brake system is designed with an oil circuit. If the oil circuit is blocked or leaks oil, the maintenance cost will increase accordingly.

Applicable models:

It is generally used in small and medium-sized vehicles. In recent years, there has been a trend towards medium-sized vehicles. For example, oil brakes are generally used for trucks with a load of less than 10t or medium-sized buses with a load of less than 19 seats.

3. Hydraulic brake

The braking force is transmitted through the brake fluid to promote the friction between the friction plate and the brake drum and play a braking role.

In principle, the hydraulic brake is the same as the oil brake. Many car owners also refer to the hydraulic brake as the oil brake. To be exact, the oil brake belongs to the hydraulic brake, but the brake oil is only one kind of brake fluid.

4. Exhaust brake

Exhaust brake is also called exhaust brake, and it is also a braking method frequently consulted by users.

Principle:

In general, the exhaust brake valve is installed at the middle and upper section of the engine exhaust pipe. When the driver turns on the exhaust brake switch on a long downhill, the exhaust valve will be closed to a certain extent, but not completely closed. The opening will be adjusted according to the pressure in the exhaust manifold, so that the engine piston will be subjected to the reverse pressure of gas during the exhaust stroke, slowing down the engine speed and generating braking effect. Therefore, the exhaust brake is also a kind of engine brake.

characteristic:

Unlike the air brake and oil brake, the exhaust brake is a kind of auxiliary brake. Its function is to slow down or maintain the speed of the vehicle under the condition that the service brake device is not used or less used, and cannot achieve emergency braking.

Applicable models:

The exhaust brake is generally used on freight vehicles and is a supplement to the service brake.

5. Air brake

Although the air break brake sounds like the exhaust brake, they are completely different. Air brake is also called energy storage spring brake, which is a kind of parking brake, that is, a kind of hand brake system.

Principle:

As we all know, the parking brake can only be used when the vehicle is stationary, because its braking torque acts on the transmission shaft. If it is used during driving, it is easy to cause serious overload of the transmission shaft and rear axle. It may also cause the rotation direction of the left and right wheels to be opposite due to the locking of the differential case, which may cause the vehicle to deviate or turn around during braking.

But the air brake is different. Because the parking brake stroke of the energy storage spring is greater than the service brake stroke, in the case of insufficient service brake force, the energy storage spring can be used to assist in emergency braking.

characteristic:

The cut-off air brake system can not only be used for parking brake, but also for emergency brake. However, it is essentially a parking brake and cannot replace the service brake device.

Applicable models:

Air break brake is generally used on medium and large trucks. At present, air break brake is mostly used for rear brake cylinder.

6. Electromagnetic brake

On large tonnage freight cars or large buses, electromagnetic brake can appear as an auxiliary brake device, also known as eddy current retarder. Its principle is to use the resistance generated by electromagnetic field to slow down the vehicle running and slow down the wear of the brake system.

On trailers such as caravans, the electromagnetic brake mainly controls the brake signal and braking force through current, and connects the brake controller with the brake system of the front vehicle to synchronize the brake signals of the front and rear vehicles.

However, the effect of the electromagnetic brake is closely related to the controller. It is difficult for the poor controller to accurately adjust the braking force. Even after adjustment, it cannot be maintained and needs to be adjusted frequently.

advantage:

The braking effect is stable and the braking force can be adjusted at any time to adapt to the braking capacity of different vehicles in front and the braking habits of different drivers. High specification electric brakes can even automatically increase or decrease the braking force according to the road slope based on the adjusted braking force to improve safety. In addition, an emergency switch will be set on the brake synchronizer to help the front vehicle stop in case of brake failure.

Disadvantages:

The structure is complex, and the brake synchronizer needs to be installed on the front vehicle. The line connection is long, which is easy to cause problems.

7. Wire brake

Wire brake is a braking mode with relatively simple principle and structure.

Principle:

Use the force of metal brake wire to pull the piston and push the brake pad to achieve braking.

advantage:

Simple structure, easy installation and maintenance, low price.

Disadvantages:

Insufficient braking force.

Applicable models:

It is mainly used for small cars.

8. Bump brake

As the name implies, it refers to a way of braking through the collision between the trailer and the front vehicle.

Principle:

When the front vehicle is in the braking state, the trailer will generate a forward force due to inertia. At this time, the collapse mechanism at the connection of the trailer and the front vehicle is compressed, the brake line is tightened and the trailer wheels are braked.

Since the front car and the trailer are hard links, there is no need to worry that the trailer will hit the front car. Some collision braking devices can take effect when the speed of the rear vehicle is faster than that of the front vehicle, some can only take effect when the wheels are turning forward, and others can only take effect when the vehicle reaches a certain speed.

advantage:

Simple and reliable, pure mechanical structure. As long as you pay attention to maintenance, the probability of problems in the system itself is very small.

Disadvantages:

The collision brake belongs to the passive brake. The vehicle owner cannot control the force and cannot brake when climbing a slope. In some extreme cases, such as the driving speed is too fast, braking in a curve or reversing from a slope to a slope, there is certain danger.

Applicable models:

It is mainly used for light trailers, generally below 1.5T.

These braking methods have different characteristics. As for which one is the safest, it depends on how well it matches the vehicle model. For example, for ordinary vehicles, the oil brake is better, but for medium and large transport vehicles, the air brake is better. When choosing the braking mode, vehicle owners should start with the vehicle model and comprehensively consider the vehicle's transportation conditions and use needs. After all, what is suitable for them is the best.