| 摘要 |
A system is described for controlling operation of a hydraulically operated transfer clutch for transmitting power to auxiliary wheels of a four-wheel drive vehicle from an engine of the vehicle. The system has a hydraulic circuit (70-72) for supplying oil to the hydraulically operated clutch (43), including a hydraulically operated control valve (72) for controlling fluid flow to the hydraulically operated clutch (43). A hydraulic control circuit (74-77) includes a solenoid operated valve (77) for controlling operation of the hydraulically operated control valve (72). The load on the engine is detected and a load signal dependent on the load produced. An electric circuit (48) controls solenoid operated valve, and is responsive to the load signal for producing a clutch engaging control signal the magnitude of which is dependent on the load. The clutch engaging control signal is applied to the solenoid operated valve (77), so that the clutch torque decreases with a decrease of the load. |
