DIRECT-COUPLED CLUTCH CONTROLLER FOR HYDRAULIC TRANSMISSION DEVICE

摘要

PURPOSE:To achieve smooth engagement/disengagement of direct-coupled clutch by inputting the solenoid pressure produced from a solenoid valve to be duty controlled as the control pressure of spool valve. CONSTITUTION:The spool 422 is lockup relay valve 420 is communicated through a resistor r10 to an oil path 2A while receives the solenoid pressure Ps of oil path 2D provided with a solenoid valve S3 and subjected to the load of spring 426 from underside. The spool 432 is set upward if the solenoid pressure Ps is lower than a setting level Ps1 to communicate between a drain oil path 6c and the engaging side oil path 6B of direct-coupled clutch. Consequently, the direct- coupled clutch 80 is disengaged. Since the solenoid valve S3 is duty controlled, the direct-coupled clutch can be engaged/disengaged smoothly.