| 摘要 |
PURPOSE:To improve drag preventive effect and minimize the clutch fitting time by making the gap between friction plates adjustable from the outside. CONSTITUTION:Besides a main hydraulic piston 7, an auxiliary hydraulic piston 10 is provided in an operating cylinder 8, and operating oil supply passages 11 and 12 which operate these pistons while pressing a return spring 9, are provided therein. A hydraulic changeover valve 15 which communicates or closes these passages, is also interposed therein. When the operating oil has a high temperature, the operating oil communicates with the operating oil supply passage 12 by the expansion. Hence, the auxiliary hydraulic piston 10 operates up to the position of a stopper 10A, and the main hydraulic piston 7 is also pushed out. Therefore, when a hydraulic changeover valve is operated, the operating oil supply passage 11 communicates with the hydraulic pump side, and main and auxiliary hydraulic pistons 7 and 10 operate together. Hence, the interval between the main piston 7 and the friction plate 6 becomes small. At the time when the operating oil has a low temperature, only the main piston operates and the interval between the main piston 7 and the friction plate 6 becomes great. Drag at the time when the operating oil has a low temperature, can be prevented and the clutch fitting time at the time when the operating oil has a low temperature, can be minimized. |
