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(1)
Purpose
The purpose of the brake valve is to sensitively increase and decrease the braking pressure when
the brake pedal is actuated.
(2)
Ready position
A connection is established between ports(BR) and ports(T) so that the wheel brakes ports(BR)
are pressureless via the returns ports(T).
(3)
Partial braking
When the brake valve is actuated, an amount of hydraulic pressure is output as a ratio of the foot
force applied.
The main spring(6) beneath pedal plate(12) is designed in such a way that the braking pressure
changes depending on the angle. In the lower braking pressure range, the machine can be
slowed sensitively.
When the braking process is commenced, the spool(2) is mechanically actuated via main spring
(6). As spool(2) move downward, they will first close returns(T) via the control edges, thus
establishing a connection between accumulator ports(P) and ports(BR) for the wheel brake
cylinders. The foot force applied now determines the output braking pressure. The control
spool(2) is held in the control position by the force applied(Spring assembly above the spool).
After output of the braking pressure, spool(2) is in a partial braking position, causing ports(P) and
ports(T) to close and holding the pressure in ports(BR).
(4)
Full braking position
When pedal is fully actuated, end position of the brakes is reached and a connection established
between accumulator ports(P) and brake cylinder ports(BR). Returns(T) are closed at this point.
When the braking process is ended, a connection is once again established between brake
cylinder ports(BR) and return ports(T), closing accumulator ports(P).
(5)
Limiting the braking pressure
Pedal restriction bolt(19) on base plate below pedal is used to limit the braking pressure.
(6)
Installation requirements
Return lines(T) must be connected directly to the tank.
The connecting lines must be installed is such a way as to permit proper bleeding.
(7)
Maintenance of the brake valve
No special maintenance beyond the legal requirements is necessary.
When using high-pressure cleaners on the machine, please make sure that the water jet is not
aimed directly at the brake valve(To prevent damaging the bellows).
For safety reasons the whole of the brake valve must be replaced if parts other than those
listed above are damaged.
4-14
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