초록 ▼

A valve operating device for an internal combustion engine that includes a valve piston having one end facing into a damper chamber and the other end operatively coupled to an intake or exhaust valve which is spring-biased in a closing direction. A cam piston has one end operatively coupled to a cam

A valve operating device for an internal combustion engine that includes a valve piston having one end facing into a damper chamber and the other end operatively coupled to an intake or exhaust valve which is spring-biased in a closing direction. A cam piston has one end operatively coupled to a cam drivable by a crankshaft and the other end disposed in a working oil chamber. A restriction mechanism uniformly restricts oil flow during final valve closing operation of the intake or exhaust valve until the valve is fully closed. The working oil chamber and damper chamber are held in communication with each other through the restriction mechanism. A bypass passage interconnects the damper chamber and the working oil chamber in bypassing relation to the restriction mechanism. A variable restriction mechanism is provided in the bypass passage capable of varying the area for oil flow according to valve closing characteristics required by the viscosity of working oil and operating conditions of the engine.

대표청구항 ▼

In a valve operating device for an internal combustion engine including a valve piston operatively coupled to an intake or exhaust valve and communicates with a working oil chamber that is pressurized for operating the valve piston, an improvement comprising a bypass passage for returning the workin

In a valve operating device for an internal combustion engine including a valve piston operatively coupled to an intake or exhaust valve and communicates with a working oil chamber that is pressurized for operating the valve piston, an improvement comprising a bypass passage for returning the working oil to the working chamber during closing of the intake or exhaust valve, and a variable restriction mechanism capable of varying a cross-sectional area for said returning oil flow through said bypass passage for selectively varying the valve closing characteristics.