GF42.25-W-3002D | Brake application at rear axle, function | 28.2.07 |
MODEL 374.6, 375.4, 940, 942, 943, 944, 950.5 /6, 952.5 /6, 953.6, 954.5
with CODE (BB8) Brake control (BS) with ASR
with CODE (ZX2) EPB II
MODEL 970, 972, 974, 975, 976
with CODE (BB1) Brake control (BS)
with CODE (ZX2) EPB II
MODEL 970, 972, 974, 975, 976
with CODE (BB8) Brake control (BS) with ASR
with CODE (ZX2) EPB II
W42.25-1166-79
12.07 Brake wear sensor
12.08 Rpm sensor
13.08 Central Brake Unit (CBU)
18.07 Trailer control valve
20.02 Single-circuit diaphragm brake cylinder
22.01 Combination brake cylinder
24.04 Pressure ratio valve
31.13 Drive-axle axle modulator
A110a1 Telligent brake system (BS) control unit
CAN 6 Brakes CAN
V1 System pressure (circuit 1)
V2 System pressure (circuit 2)
a System pressure
b Brake pressure
c Redundant brake pressure
d Control pressure
AV Outlet valve
B Brake value sensor
D Pressure sensor
EV Intake valve
FB Parking brake
PV Proportioning valve
RD Redundancy valve
RE Control electronics
RV Relay valve
W Position sensor
When the brake pedal is operated, the position sensors (W) register the pedal travel and report it to the brake system (BS) control unit (A110a1).
The target deceleration calculated by the brake system (BS) control unit (A110a1) is transmitted to the control electronics (RE) in the drive-axle axle modulator (31.13). The data exchange occurs via the brakes CAN (CAN 6).
So that the electropneumatic brake circuit is not overlaid by redundant brake pressure (c), the redundancy valve (RD) at the drive-axle axle modulator (31.13) is closed electrically.
The control electronics (RE) close the exhaust valve (AV), and the intake valve (EV), in accordance with the specified deceleration as calculated by the brake control (BS) control unit (A110a1), then forwards the pending reservoir pressure (a) as control pressure (d) to the relay valves (RV) in the drive-axle axle modulator (31.13).
The relay valves (RV) in the drive-axle axle modulator (31.13) set the pending reservoir pressure (a) to match the control pressure (d) of the intake valves (EV), and then forward it as brake pressure (b) to connections 21, 22 and the rear axle's combination brake cylinder (22.01).
The pressure sensors (D) in the drive-axle axle modulator (31.13) signal the brake pressures as set by the relay valves (RV) in the drive-axle axle modulator (31.13) (b) to the control electronics (RE).
The rpm sensors (12.08) evaluate any wheel rpm change and provide the brake system (BS) control unit (A110a1) with feedback on the actual deceleration attained and the wheel slip. If the actual deceleration deviates from the target deceleration, the brake control (BS) control unit (A110a1) corrects accordingly.
When the brake pedal is released, the applied brake pressure (b) and the control pressure (d) are released via the vent,
connection 3.