6.2. Appointment and short description of elements of hydraulic system of a working brake
Fig. 6.1. Components of the brake system and their arrangement on the car: 1 — a brake pedal; 2 — the stoplight switch; 3 — the hydrovacuum amplifier of brakes; 4 — the main brake cylinder; 5 — the ABS block (anti-blocking system); 6 — the regulator of pressure of back brakes; 7 — the lever of the parking brake; 8 — a support of a back wheel; 9 — a support of a forward wheel; 10 — the sensor of speed of a back wheel; 11 — the sensor of speed of a forward wheel; 12 — a tank for brake fluid
Fig. 6.2. Scheme of hydraulic system of a working brake: 1 — backpressure valves; 2 — the valve of the plunger pump; 3 — the hydroaccumulator; 4 — the camera of suppression of a pulsation in system; 5 — the electric motor with the eccentric plunger pump; 6 — a tank for brake fluid; 7 — a pedal of a working brake; 8 — the amplifier; 9 — the main brake cylinder; 10 — the ABS block; 11 — the final operated valves; 12 — the inlet operated valves; 13 — the drosseliruyushchy valve; 14 — 17 — brake mechanisms
The pedal 7 working brakes is the instrument of actuating of the brake system and the regulator of intensity of braking. Before it the stoplight switch is installed. It lights fires of signals of braking and sends a signal of the beginning of braking to the control unit.
The amplifier 8 of a brake is located between a pedal of a brake and the main cylinder 9.
The amplifier increases force attached by the driver to a pedal when braking concerning 4:1. Necessary depression is created at the expense of the message with an inlet collector of the engine and installation of the unilateral valve preventing return of air to a cavity of the amplifier in the absence of depression in an inlet collector. The main brake cylinder has two pistons. Each piston works only for the contour: one cylinder on right forward and left back, the second — on left forward and right back wheels.
The tank 6 for brake fluid is divided into three capacities, two of which are intended for brake contours, and the third — for the coupling drive in cars with the mechanical transmission. Capacities are separated one from another. At emergence of a leak in one of contours full overall performance of other contours remains.
On a tank there are tags of "min" and "max", honey which there has to be level of brake fluid. On a cover of a tank the sensor lighting the warning frame at the provision of level below admissible is installed. Brand of the DOT4+ brake fluid.
The block 10 ABS Bosch of version 5.0 concerns to new generation of the ABS systems, representing the closed hydraulic system which does not have the channel for return of brake fluid to the tank feeding the main brake cylinder.
Electronic and hydraulic components are mounted as uniform knot. Enter their number, except specified in the scheme: the relay for turning on of the electric motor of the plunger pump 5 and the relay of turning on of inlet 12 and final 11 valves. All block is mounted under the right wing, just before McPherson's rack. External components are: an alarm lamp of work of ABS in the dashboard 1 which lights up in case of malfunction in system, and also at inclusion of ignition within four seconds; switch of a stoplight and sensors of speed of rotation of wheels. The block has a conclusion to the diagnostic socket.
The Drosseliruyushchy valve is installed for decrease in brake effort on back wheels for the purpose of avoidance of their blocking. It is located directly in tubes and fixed on a back board (Torpedo) of a motor compartment. Because the brake system
has control on "weaker" back wheel (it means that pressure of brakes of back wheels identical, and its size is established on the wheel, closest to blocking), the drosseliruyushchy valve is installed one on a contour.
Brake mechanisms 14 — 17 include brake disks and one-piston supports with the floating bracket and brake shoes equipped with brackets of control of wear of frictional slips. Brake mechanisms of back wheels are similar to lobbies, but have continuous brake disks (on lobbies — ventilated) and the executive mechanism of the parking brake which is built in in a support.