GF42.25-W-2010D | Trailer control, function | 20.1.10 |
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
W42.25-1234-79
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
35.02 Coupling head for supply
35.03 Coupling head for brake
A110a1 Electronic brake system (EBS) control unit
CAN 6 Brakes CAN
V1 System pressure (circuit 1)
V2 System pressure (circuit 2)
V3 System pressure (circuit 3)
a System pressure
b Brake pressure
c Redundant brake pressure
d Control pressure
AS Breakaway coupling
AV Outlet valve
B Brake value sensor
D Pressure sensor
EV Inlet 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 via the brakes CAN (CAN 6) to the control electronics (RE) of the drive-axle axle modulator (31.13).
The proportional valve (PV) in the trailer control valve (18.07) is actuated by the control electronics (RE) of the drive-axle axle modulator (31.13) to match the specified deceleration, and forwards the pending reservoir pressure (a) as control pressure (d) to the relay valve (RV) in the trailer control valve (18.07).
Applied at the same time to this relay valve (RV) via connection 42 is the redundant brake pressure (c) and the control pressure (d) set by the proportional valve (PV) in the trailer control valve (18.07). The control pressure (d) set by the proportioning valve (PV) is preferred, and the available system pressure (a) flows to the coupling head for brake (35.03) as a brake pressure (b) proportional to the control pressure (d).
The pressure sensor (D) in the trailer control valve (18.07) signals the brake pressure (b) set by the relay valve (RV) in the trailer control valve (18.07) to the control electronics (RE) of the drive-axle axle modulator (31.13).
The rpm sensors (12.08) evaluate any wheel rpm change and provide the control electronics (RE) of the drive-axle axle modulator (31.13) with feedback on the actual deceleration attained and the wheel slip. If the actual deceleration deviates from the target deceleration, the drive-axle axle modulator (31.13) 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).