The braking systems of a cars include:
- working brake system;
- parking brake system;
- emergency brake system.
The service brake system includes:
- brake drive;
- brake mechanisms;
- brake booster.
Hydraulic dual-circuit brake drive – front wheel contour and rear wheel contour. The brake drive includes a dual master cylinder, pipelines, a hydraulic actuator failure indicator, and wheel working brake cylinders.
The twin main cylinder consists of primary and secondary pistons, on which floating piston heads are installed using connecting rods, which act as overflow valves. In the disinhibited state of the wheels, there are gaps between the heads and pistons; therefore, the pre-piston cavities communicate with the tank. During braking, the pistons move, are pressed against the heads, which is facilitated by the springs and the sealing rings of the heads, the pre-piston cavities are disconnected from the tank, the pistons through the overpressure valves create fluid pressure in the drives of the front and rear wheels, respectively.
The overpressure valve consists of a metal disk with six holes, a rubber body and a spring. When braking, the fluid under pressure, passing through the holes and bending the edges of the rubber casing, enters the wheel brake cylinders. When braking, the pistons return to their original position, liquid, overcoming the resistance of the spring of the overpressure valve, opens the valve and returns to the cavity of the cylinders, and then, when the fluid pressure drops, the spring presses the valve against the housing, the edges of which close the openings and a slight excess pressure remains in the actuators .
In the event of a malfunction of the front wheel contour, the secondary piston idles to the stop of the connecting rod; the operation of the brake drive of the rear wheels in this case occurs in the usual manner. In case of violation of the rear wheel drive, the primary piston through the connecting rod and the stop sets the secondary piston in motion, which supplies fluid to the front wheel drive.
Brake mechanisms of front and rear wheels of drum-shoe type. The brake mechanism consists of a brake shield, two pads with friction linings and coupling springs and a brake drum. Brake booster. Cars have two hydraulic vacuum amplifiers – one front serves the contour of the front wheels, the second serves the contour of the rear wheels.
The parking brake system includes a brake drive and brake mechanisms.
The mechanical transmission has a brake drive that affects the transmission mechanisms.
Drum-shoe brakes are mounted on gearbox parts. Spare brake system – one of the circuits of the working brake system.
The hydraulic circuit of the dual-circuit brake system of the car:
1 – front brake mechanism; 2 – an inlet pipe of the engine; 3 – shutoff valve; 4 – indicator lamp; 5 – hydraulic actuator failure indicator; 6 – the main cylinder; 7 – filling tank; 8 – air filter; 9 – rear brake mechanism; 10 – rear hydro-vacuum amplifier; 11 – front hydraulic vacuum amplifier.
