OilQuick OQ 70/55, Руководство по эксплуатации и инструкции по монтажу

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Version 1.1 11 2011-06-28
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3. H-cylinder – function and requirements
The H-cylinder is the key component in the quick coupler.
When working with a hydraulic attachment, the H-cylinder must ensure that the tool is securely attached and
the hydraulic couplings are properly connected.
The hydraulic circuit diagram for the H-cylinder is shown below.
1. Locking cylinder
2. Pilot-controlled check valves
3. Pressure controller
4. Control valve for the
excavator's quick coupler system
5. Hydraulic pump
6. Hydraulic tank
In today's excavators, both the pressure and the oil flow from the machine's hydraulic pump (5) change in
relation to the excavator load. Unlike many other systems, the OilQuick quick coupler system operates at the
excavator's maximum working pressure. This is necessary to ensure that the coupler part is securely locked
to the attachment frame on the tool with no play. In addition, the H-cylinder guarantees that the quick
couplers are connected properly. When the tool is attached, the pressure on the positive side of the cylinders
(1) builds up to the maximum level for the machine.
If the machine pressure changes, the two pilot-controlled check valves (2) ensure that the pressure in the
cylinders (1) remains constant. Whenever the pump pressure (5) rises, oil is supplied to the cylinders (1).
If the pressure in the cylinders (1) exceeds 45 MPa, the control valves (3) open on the tank side (6) and
reduce the pressure.
When the quick coupler unlocks for disconnecting the attachment, the control valve (4) is operated.
In this case, the H-cylinder's negative side is pressurized, the pilot-controlled check valves (2) open and the
H-cylinder releases the lock. If oil supply to the H-cylinder is stopped (e.g in case of hose rupture), it is pre-
vented to be opened as the pilot operated check valves (2) ensure that existing oil can not leave the
H-cylinder without pressure on the negative side.
The H-cylinder in the OilQuick quick
coupler system must:

be directly connected to the pump
 have an open return line to the tank
 lock at the maximum pressure for
the excavator's hydraulic system
H-cylinder