US 6,745,731 B2Granted

Valve driving device of an internal combustion engine

AssigneeIsuzu Motors Limited

InventorsTsuneo Tanaka, Akihiko Minato, Yoshihiro Arakawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

A valve driving device reduces the volume of the pressure chamber and decreases the energy supplied during driving to open the main valve. As a result of this initial energy, the main valve is lifted by inertial motion. When the main valve is opened (lifted), a first actuating valve is opened, and high-pressure actuating fluid is supplied to the pressure chamber. When in this process the pressure in the pressure chamber falls below the pressure of a low-pressure chamber, a second actuating valve opens independently, and low-pressure actuating fluid is introduced into the pressure chamber. By this means negative pressure in the pressure chamber can be prevented, and the main valve can be held in a lift position equivalent to the initial energy. When the main valve is to be closed, an actuator forcibly opens the second actuating valve. Then, high-pressure actuating fluid in the pressure chamber passes through the second actuating valve, presses and opens a third actuating valve on the downstream side, and is discharged to a path.

A valve driving device of an internal combustion engine, to drive the opening and closing of a main valve serving as an intake valve or an exhaust valve of said internal combustion engine, comprising:

a pressure chamber, to which is supplied pressurized actuating fluid in order to open said main valve;
a high-pressure actuating fluid supply source, connected to said pressure chamber;
a low-pressure actuating fluid supply source, connected to said pressure chamber;
a first actuating valve, provided between said pressure chamber and said high-pressure actuating fluid supply source, which is opened for a prescribed period in an initial opening period of said main valve, and which supplies high-pressure actuating fluid from said high-pressure actuating fluid supply source to said pressure chamber;
a second actuating valve, provided between said pressure chamber and said low-pressure actuating fluid supply source, comprising a check-valve which, after said prescribed interval in the initial opening period of said main valve has elapsed, is opened based on the pressure difference when the pressure of said pressure chamber falls below the pressure of said low-pressure actuating fluid supply source, and which introduces low-pressure actuating fluid from said low-pressure actuating fluid supply source into said pressure chamber;
a third actuating valve, provided between said second actuating valve and said low-pressure actuating fluid supply source or in said low-pressure actuating fluid supply source, comprising a check-valve which is opened when an inlet-side pressure is higher than a prescribed pressure setting which is higher than the pressure of said low-pressure actuating fluid supply source and is lower than the pressure of said high-pressure actuating fluid supply source, and by which means actuating fluid of said pressure chamber is discharged;
and,
an actuator, which forcibly opens said second actuating valve in order to close said main valve.

5 more elements

Abstract

Claims4