Valve timing control device

Abstract

A valve timing control device includes a driving side rotational member, a driven side rotational member, a retarded angle chamber, an advanced angle chamber, a first control valve, a supply passage supplying the fluid to the first control valve, a first pump pumping the fluid to a vapor liquid separating portion, a second pump pumping the fluid in the vapor liquid separating portion to the first control valve, a discharge passage discharging the fluid from the first control valve toward the operational fluid reservoir, and a second control valve provided at the discharge passage and operated to switch the discharge passage between a first discharge passage is discharging the fluid discharged from the first control valve to the operational fluid reservoir and a second discharge passage flowing the fluid to be drawn into the first pump.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is based on and claims priority under 35 U.S.C §119 with respect to Japanese Patent Application 2006-002312, filed on Jan. 10, 2006, the entire content of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention relates to a valve timing control device. More particularly, this invention relates to a valve timing control device which includes a driving side rotational member synchronously rotating relative to a crankshaft of an internal combustion engine, a driven side rotational member positioned coaxially to the driving side rotational member and rotatable relative to the driving side rotational member, the driven side rotational member synchronously rotating relative to a camshaft for opening and closing valves of the internal combustion engine, a retarded angle chamber formed by the driving side rotational member and the driven side rotational member and displacing a relative rotational phas...

AI Technical Summary

Benefits of technology

The present invention relates to a valve timing control device for an internal combustion engine. The device includes a driving side rotational member and a driven side rotational member rotatable relative to the driving side rotational member. The device also includes a retarded angle chamber and an advanced angle chamber for controlling the timing of valves in the engine. The device includes a first control valve for controlling the supply and discharge of an operational fluid, a supply passage and a discharge passage for the operational fluid, and a second control valve for selectively switching the discharge passage. The technical effect of the invention is to provide a valve timing control device that can accurately control the timing of valves in an internal combustion engine and optimize engine performance.

Problems solved by technology

Consequently, it is time-consuming to supply the operational fluid to the fluid pressure chambers via an oil passage of an oil pressure circuit.

For the reason, it is difficult to smoothly control the relative rotational position of the driven side rotational member relative to the driving side rotational member and properly control the opening and closing timing of an intake valve immediately after the start of the engine.

Consequently, the configuration of the valve timing control device becomes complicated, and weight of the vehicle is increased.

A certain amount of time has elapsed since the engine started, then the viscosity of the operational fluid becomes high and it is not possible to supply the operational fluid to a desired area promptly.

In order to lower the viscosity of the operational fluid, it is necessary to raise the temperature, however it needs a certain amount of time.

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