Tadano TR-800XXL4, Руководство по обслуживанию

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T - 3 T - 3
Brake Valve
10
W202-0013E
IW202-0010E04
Rubber spring
Piston
Upper valve
Discharge valve sheet
Upper body
Inlet valve sheet
7. In the secondary air system, relay piston lowers in
proportion to the air pressure in the primary
system to generate air pressure in the secondary
system. The generated pressure is also applied to
the underside of relay piston.
8. As this pressure on the underside of relay piston
becomes balanced with the primary system
pressure applied on the top of the relay piston, it
is no more pushed down, but moves up while
keeping contact with lower valve.
9. As lower valve comes into contact with the inlet
valve seat of lower body, the air supply through
the supply port is stopped.
10. In this state, since the discharge valve seat is in
contact with lower valve, the air pressure
stabilizes.
11. Thus, the pressure in the secondary system is
kept stable at a level equal to that of the primary
system. Spring serves to minimize the pressure
difference between the two systems.
IW202-0010E05
Relay piston
Lower valve
Lower body
Discharge valve sheet
Inlet valve sheet
2.3 Release of air pressure
1. As the pedal is released, the plunger and piston
are pushed up by the return spring and by the
primary air pressure.
2. The discharge air seat at the bottom of the piston
disengages from the upper valve, opening the
discharge passage at the center. This allows the
primary system air pressure to be discharged from
the discharge port.
3. On the other hand, as the pressure in the primary
system drops, relay piston is pushed up by the
secondary system air pressure and springs, and
the discharge valve seat at the bottom of relay
piston disengages from lower valve to open the
central discharge passage.
4. Thus the secondary system pressure discharges
into the discharge port.