PURPOSE: To reduce calculation load on a microcomputer and prevent a valve lift amount and a lift interval from becoming short by surge pressure in high speed range.
CONSTITUTION: An intake valve 1 provided with a valve spring 2 is interconnected to a valve side plunger 3, and lifted by the pressure of hydraulic oil pressurized by a cam side plunger 6. Also a release valve 21 to control the lift amount is provide with a main valve element 25 and a pilot valve element 35, and the pilot valve element 35 is pressed by the hydraulic oil inside a back pressure chamber 29 in the direction of lifting and also pressed by a pilot spring 37 and the magnetic force of a solenoid 38 in the seating direction. When the pressure of hydraulic oil increases and it lifts the valve by a specified amount, pressing pressure from the back pressure chamber 29 exceeds that by the solenoid 38 and the like. Therefore the pilot valve element 35 lifts and, at the same time, the main valve element 25 opens. In addition, lubricating oil pressure is introduced into an auxiliary hydraulic pressure chamber 41 so as to resist surge pressure in high speed range.
KAMEGAYA SHIGERU
INOKUCHI IWANE
TOKUMASU HIROSHI
TAGAMI MASAFUMI
NISSAN MOTOR
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