Brake master cylinders, also known as "brake master cylinders" and "brake master cylinders", are the main cooperating parts of the vehicle's brake system. They are also divided into air brake master cylinders and oil brake master cylinders according to different vehicles. In general, most brake master cylinders of passenger cars (such as cars, micro passengers, etc.) use oil brake master cylinders, while commercial vehicle (such as trucks, tractors, etc.) generally use air brake master cylinders. Brake master cylinder.
The brake master cylinder using an oil brake has a tank for storing brake oil on the top, and a piston and an oil inlet and outlet in the cylinder below. When the brake is stepped on, the piston is pushed by the brake pedal in the cylinder, and then acts through the push rod to transmit the brake oil pressure in the cylinder to the brake cylinders of each wheel to produce a braking function. When the brake pedal is released, the oil outlet in the brake master cylinder will be closed and the oil inlet will be opened, so that the brake oil will return from the brake cylinder to the brake master cylinder and return to the original state.
The working principle of the brake master cylinder using air brakes and the brake master cylinder using oil brakes are basically the same. They both function as valves. The difference is that the oil brake master cylinder controls the return of brake oil to the storage after the end of the braking action. In the oil tank, vehicles with air brakes usually have several large air reservoirs suspended on the frame. After the braking action, the gas will be directly discharged, so we often hear loud exhaust sounds when large trucks brake. .
The structure and working principle of the hydraulic brake master cylinder is the foundation of the entire hydraulic brake. The fault diagnosis of the hydraulic brake system is based on a deep understanding of the master cylinder structure and working principle.
The main components of the brake master cylinder are the housing, the piston, the return spring, the sealed leather cup, and the reservoir, which are similar to our common needle tubes. During braking, the pedal pushes the piston to move, and the pressure in the working chamber composed of the piston, the sealed leather cup and the housing increases, and the brake fluid is discharged to the wheel cylinder.
The basic structure of the master pump: the piston, the cup, the return spring, the oil outlet valve, the oil return valve, and the liquid storage pot. There are two small holes in the part of the casing that contact the liquid storage pot: hole A and hole B, and a compensation hole is provided on the piston.
In the free state, that is, when the brake is not depressed, the piston returns under the force of the return spring, and the front cup of the piston is between the hole A and the hole B. The working chamber in front of the piston communicates with the reservoir through the hole A, and the oil pressure in the working chamber is balanced with the brake fluid of the reservoir.
When the brake is depressed, the pedal pushes the master cylinder piston and the sealed leather cup forward. When the piston and the sealed leather cup cross the hole A, the working chamber is closed, the oil pressure rises, and the brake fluid is discharged to the wheel cylinder , To push the brake pad action.