known as the master cylinder brake master cylinder, the brake fluid is pressurized generator.
1. The master cylinder structure
by the master cylinder is generally a cylinder, a piston return spring, double valve (oil control valve), cups, and other parts of apron composition. The cylinder up and down in the reservoir chamber, the cylinder chamber, a piston loaded into the cylinder from the rear end of the cylinder, the cylinder is divided into the former, the two chambers of the cylinder hole leads to the front before the reservoir cup for the back hole, the front apron, the top of the cylinder after the piston chamber leading tuck macroporous reservoir for liquid inlet hole (aperture compensation). Master cylinder mounting position of the piston are imported after.
2. works
After
When the brake pedal is depressed, the master cylinder piston push rod is pushed forward, the shutter return hole in the cup, the piston front chamber oil pressure increases, the double valve intermediate the outlet valve is pushed open, oil after the brake fluid piping to a wheel cylinder of each cylinder. Oil cylinder pushing the piston against the brake shoe return spring force and open the brake shoes. Shoe pressed against the brake drum, a braking effect.
When the driver depresses the brake pedal and hold, the front wheel cylinder and the master cylinder chamber hydraulic cylinder does not increase, the oil valve is closed under the action of the spring return valve is closed, double double valve is closed, no longer the master cylinder to the wheel wheel cylinder oil, cylinder oil cylinder can not reflux, the entire line is isostatic, maintain a certain braking system braking intensity .
When the brake pedal is relaxed, under the action of the pedal return spring and the elastic piston return praise, master cylinder piston, before the master cylinder oil pressure chamber decreases toward the back, the high-pressure cylinder oil hydraulic cylinder an oil return valve extraoral double valve returns to master cylinder front chamber. With the brake fluid flows back, closed at its brake shoe return spring force, the brake state is released. Since the master cylinder piston return spring have a certain pre-stress in the assembled state, when the hydraulic pressure decreases to reflux fluid can not overcome the preload, and the oil return valve closed, the brake fluid flows back stop, and then the pipe cylinder higher than master cylinder hydraulic cylinder hydraulic cylinder of about 0.5 kg / cm. This is called a wheel cylinder and a residual pressure in pipes, the residual pressure can be rapidly implemented to provide the next braking conditions.
When the brake pedal is quickly relax, the master cylinder piston is retracted at a rapid return spring, the front chamber volume expansion of the contents of the master cylinder, the hydraulic pressure rapidly decreases, the oil cylinder of each cylinder by the conduit impact resistance, and the time to fill back into the piston front chamber, the front piston will be a negative pressure chamber, the piston chamber after the oil pressure is relatively high. Under this pressure difference, the reservoir chamber through the fluid inlet will be macroporous, the piston chamber, a piston top six holes, over the edge of the piston front chamber flows into the cup. At which time the brake pedal, and the brake fluid will be supplied to the respective wheel cylinders, in order to enhance braking efficiency. Feel the braking force is insufficient step one foot brake,Two feet braking takes effect.