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| Illustration 1 | g03729973 |
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Quick coupler components (1) Port - UNLOCK (2) Port - LOCK (3) Quick coupler hydraulic cylinder (4) Check valve (5) Wedge | |
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| Illustration 2 | g03779459 |
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Switch panel (6) Quick coupler electrical switch | |
- Quick coupler hydraulic cylinder (3) is a double acting hydraulic cylinder. The cylinder rod is extended to LOCK the coupler by extending wedge (5). The cylinder rod is retracted to UNLOCK the coupler by retracting wedge (5). A solenoid valve is used to control cylinder (3).
- Check valve (4) is used to hold cylinder (3) in the LOCKED position when oil pressure is not supplied to the head end of cylinder (3).
- Quick coupler electrical switch (6) is the operator input that is used to control the flow of oil to coupler cylinder (3). Switch (6) is either in the LOCKED or UNLOCKED position.
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| Illustration 3 | g03779067 |
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| Illustration 4 | g03778872 |
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Hydraulic schematic - LOCK (1) Port - UNLOCK (2) Port - LOCK (3) Quick coupler hydraulic cylinder (4) Check valve (6) Quick coupler control switch (7) Quick coupler (8) Quick coupler control valve (9) Solenoid valve (10) Hydraulic oil tank (11) Pump (12) Bucket control lever (13) Bucket hydraulic cylinder | |
When quick coupler electrical switch (6) is in the LOCK position, the machine ECM does not send an electrical signal to solenoid valve (9). Solenoid valve (9) is de-energized.
When solenoid valve (9) is de-energized, oil from pump (11) is directed to quick coupler control valve (8). Main pump oil flows through the check valve in quick coupler control valve (8) to the head end of coupler cylinder (3). Return oil flow from the rod end of coupler cylinder (3) flows through solenoid valve (9) and to hydraulic oil tank (10). The coupler cylinder rod extends wedge (5). Coupler hydraulic cylinder (3) is in the LOCKED position.
Note: Check valve (4) prevents oil in the head end coupler cylinder (3) from flowing to the return hydraulic circuit. Coupler cylinder (3) remains in the LOCKED position.
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| Illustration 5 | g03779060 |
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| Illustration 6 | g03779043 |
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Hydraulic schematic - UNLOCK (1) Port - UNLOCK (2) Port - LOCK (3) Quick coupler hydraulic cylinder (4) Check valve (6) Quick coupler control switch (7) Quick coupler (8) Quick coupler control valve (9) Solenoid valve (10) Hydraulic oil tank (11) Pump (12) Bucket control lever (13) Bucket hydraulic cylinder (14) Relief valve (15) Check valve (16) Relief valve | |
Quick coupler hydraulic cylinder (3) can retract only when a BUCKET CLOSE operation is being performed.
When quick coupler electrical switch (6) is in the UNLOCK position, the machine ECM sends an electrical signal to solenoid valve (9). Solenoid valve (9) is energized. Solenoid valve (9) shifts.
Oil from pump (11) flows through solenoid valve (9) and port (1) to the rod end of coupler cylinder (3). Oil from this circuit will also flow to open check valve (4). This action will allow oil to flow from the head end of coupler cylinder (3).
During a BUCKET CLOSE operation, oil flow from pump (11) flows to the head end of bucket cylinder (13). Oil from the head end of bucket cylinder (13) will overcome the setting of relief valve (14). Simultaneously, oil from bucket control lever (12) will overcome the setting of relief valve (16). Oil can now flow from quick coupler (7).
Return oil flow from the head end of coupler cylinder (3) through check valve (4) and port (2). Oil will then flow pass relief valve (14) and relief valve (16). The return oil then flows through solenoid valve (9) to hydraulic oil tank (10). The coupler cylinder rod retracts and wedge (5). Coupler hydraulic cylinder (3) is in the UNLOCKED position.
When the BUCKET CLOSE operation is stopped, relief valve (14) closes. The quick coupler remains in the UNLOCKED position.