PURPOSE: To speedily carry out seating and moving of a suction and exhaust valve by providing an escape passage communicating a back pressure chamber and a low pressure side to each other at the time of lifting a main valve between the back pressure chamber to pressurize the main valve of a release valve in the seating direction and the low pressure side.
CONSTITUTION: Operating oil is pressurized by outward movement of a cam side plunger 2, and when its pressure reaches specified pressure, a suchtion and exhaust valve lifts against a valve spring 5 in a state where a pilot valve 89 of a release valve 8 is seated on a valve seat 91 and a main valve 83 is seated on a valve seat 84. When pressurizing force against the pilot valve 89 by operating oil overcomes magnetic force of a solenoid 90 in the middle of outward movement of the plunger 2, the pilot valve 89 and the main valve 83 sequentially lift. Consequently, operating oil of a main cylinder 1 and a cylinder 3 is released through the release valve 8, and the suction and exhaust valve 6 is seated by a valve spring 5. Additionally, at this time, a back pressure chamber 86 is communicated to an accumulator 7 through an escape passage 13, and the suction and exhaust valve 6 is speedily seated on the seat valve.
TOKUMASU HIROSHI
SATO YUJI
INOKUCHI IWANE
SAKAMOTO ATSUHIRO
NISSAN MOTOR