The main components of Toyota's brake master cylinder are the housing, piston, return spring, sealed leather cup, and fluid 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 Toyota 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 increases, and the brake fluid is discharged to the wheel. The pump pushes the brake pads into action.
When the brake pedal is released, the master cylinder piston returns to its position under the force of the return spring, the oil pressure in the working chamber drops, and the cylinder and pipeline return oil. But if you quickly release the brake pedal, the brake fluid at the rear of the piston will overturn the cup through the compensation hole on the piston and enter the working chamber in front of the piston. Then, when the brake is depressed again, the brake fluid in the working chamber is discharged to the oil circuit and the cylinder again. Such rapid and repeated release and braking of the brakes, because the brake fluid at the rear of the piston compensates into the working chamber, so that the working chamber produces more oil every time and less oil returns. This function is called the compensation function of the Toyota master cylinder. .
In order to improve the safety of the car, the modern vehicle's service brake system uses a dual-circuit brake system. Dual circuit refers to the use of independent dual-chamber brake master cylinders to control the two-axle or three-axle wheel brakes through two independent pipelines. The characteristic is that if one of the pipelines fails and the other brake fails, the other The set of pipelines can still continue to play the role of braking, thereby improving the reliability and driving safety of automobile braking.