Kalmar ContChamp DRD S Series, Technical Handbook

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ContChamp DRD-S
Technical Handbook
Brake system
Description
27 S. Grupp 70
9407
04-10
Accumulator charging valve
The function of the accumulator charging valve is to divert the
pump flow to the accumulator whenever the latter needs charg-
ing. This ensures that the brake system is given priority and is
first to receive oil.
When the accumulators are fully charged, the entire flow from
pump 5 is fed to the brake cooling circuit
During charging, the pump delivers oil through a check valve to
the accumulator. A restriction limits the flow to a maximum of ap-
prox. 17 l/min. At the same time, pilot oil pressure is supplied
across the pilot valve to the main valve, where it is added to the
spring force and keeps the main valve closed.
When the accumulator has been charged, the oil pressure from
the accumulator overcomes the spring force in the pilot valve
which changes over and relieves the pilot pressure to the tank.
The main valve changes over and opens the connection to the
cooling circuit motor.
The difference between the pressures at which charging is start-
ed and stopped is determined by the difference in area between
the pressure and tank connections of the valve, and amounts to
about 18% of the pressure at which charging is stopped, i.e.
about 27 bar at a pressure of 150 bar and about 30 bar at 165 bar.
1. To brake system
2. Accumulator
3. Charging pressure adjusting
screw
4. Pilot valve
5. Main valve
6. Check valve
7. To cooling circuit
8. Tank connection
9. Accumulator connection
10. Pump connection
Accumulator charging valve
KL1420