What is the working principle of automobile wheel brake?



The automobile wheel brake is composed of brake wheel cylinder, brake caliper, brake disc and brake pad.

The automobile wheel brake is composed of brake wheel cylinder, brake caliper, brake disc and brake pad.

Brake slave cylinder: the brake wheel cylinder is used to convert the hydraulic energy input from the brake master cylinder into mechanical energy, so that the brake can enter the working state.

Brake caliper: during braking, the brake fluid enters the brake caliper through the brake oil pipe from the brake master cylinder, and the brake fluid pushes the caliper to move and press the brake pad, thus stopping the vehicle.

Brake disc: It also rotates when the car is moving. The brake caliper clamps the brake disc to generate braking force. When you step on the brake, it clamps the brake disc to decelerate or stop.

Automatic lining: the working principle of the brake is mainly from friction. The friction between the brake lining and the brake disc (drum) and between the tire and the ground is used to convert the kinetic energy of the vehicle moving into the heat energy after friction, so as to stop the vehicle

How to give first aid if the wheel brake breaks down on the way?

1. Brake failure

First, open the exhaust brake, use the diesel engine brake to slow down, and use greater force for emergency parking brake. If the above methods are still invalid, and the diesel vehicle is in danger of collision or sliding, the last first aid method can be used, that is, turn off the engine and put the transmission into the lowest gear. For diesel vehicles without synchronizer, the "empty oil" will explode quickly when turning into the low gear, and the transmission should be operated quickly, accurately and forcefully, which can help to stop the vehicle in an emergency. At this time, if the diesel vehicle slides on the ramp, it can also use the roadside natural environment or facilities, such as mounds, railings, tree trunks and other things that can help the diesel vehicle decelerate to rub the vehicle body to stop.

2. Excessive brake shoe clearance

Excessive clearance caused by worn wheel brake shoe will lead to brake failure or brake seizure. If it cannot be eliminated after the brake is fully adjusted, the brake shoe "wearing" method can be used for emergency treatment. The specific method is to first make a rectangular iron box with iron sheet, and then put a number of shims of appropriate thickness in it. The iron box is sleeved on the upper end of the brake shoe. After reassembly, the gap between the brake shoe and the drum can be reduced to achieve the braking effect.

3. Brake chamber diaphragm damaged

Damage to the brake chamber diaphragm will cause brake deviation or brake failure. In case of such a situation on the road, a new diaphragm shall be replaced in time. If there is no spare part, the inner tube of the diesel vehicle can be cut into a circle of the same size as the original diaphragm and covered on the back of the original diaphragm. As there are many diaphragm fixing holes, it is not easy to accurately locate the holes made on the substitute rubber. First, cut the rubber into circular fixing holes every 90 ° with scissors, and then use four bolts to pass through the four fixing holes to fix the rubber on the air chamber. Then, punch the rubber according to the position of the connecting holes of the original air chamber housing. Each hole is fastened with bolts, punched one by one, and tightened one by one. After all the bolts are tightened, check whether there is air leakage. If there is no air leakage, Is ready to use.

4. The brake shoe friction plate is greasy

During driving, if there is oil stain on the brake shoe friction plate and brake drum, scorch and carbonization on the surface, it should be eliminated in time, otherwise it will lead to brake performance degradation, brake inflexibility, brake deviation and other faults. The specific method for elimination is to repair the oil seal first, because the oil stain, burning and carbonization may be caused by the lubricating grease entering the brake due to the oil leakage of the hub oil seal. The oil stain on the brake shoe friction plate can be cleaned with gasoline. If the oil stain is serious, the dirt on the brake shoe friction plate can be removed with coarse sandpaper, or the brake shoe friction plate can be heated with gentle fire to make the oil stain seeping into the friction plate seep out, and then the brake shoe friction plate can be cleaned and repaired with gasoline before use. This urgent method should pay attention to fire prevention.

5. Water ingress into wheel brake

During driving, when the diesel vehicle wades into the water, sometimes the wheel brake water will enter, and the braking effect will be reduced accordingly. In this case, the method of braking while driving shall be adopted to recover the braking performance as soon as possible. The method of braking while driving is to step on the accelerator platen with your right foot, step on the brake pedal with your left foot, and drive at medium speed on a wide and straight road with good road conditions, so as to increase the friction between the friction lining of the wheel brake and the brake drum as much as possible, and quickly evaporate the moisture by using the friction heat, which can restore the original braking performance, so as to improve the braking performance.

6. Broken brake hose

Brake hose rupture will lead to brake failure. In case of this situation during driving, stop the vehicle immediately. The specific method is to take a piece of suitable inner tube rubber and wrap it at the crack, then use a metal clip to clamp it at the inner tube rubber, tighten the locking bolt, or use thin iron sheet or copper sheet to replace the metal clip, and then use iron wire to wrap it tightly. After it is checked that there is no air leakage, it can be used in an emergency. If there is an adhesive such as quick drying adhesive, the air pipe can be polished and then the thin iron sheet, copper sheet, rubber sheet, etc. can be bonded.