Unisia Jecs Corporation

Hitachi, Ltd.

Akinobu Maeyama

Masanori Koda

Tomoya Tsukada

Yoshihiko Yamada

Hiroaki Imai

Hideyuki Miyasaka

In a variable valve system for an internal combustion engine and its driving mechanism, the variable valve system comprises: a variable mechanism that revolves a control axle to change an operation characteristic of an engine valve; a projection section projected at an outer peripheral predetermined position in an axial direction of the control axle and on a tip of which a fixture section is formed; a fixture member fixed in a grasped state for the projection member via an engagement member engaged on the fixture section; a driving mechanism configured to provide a rotating force for the control axle via the fixture member; and control means (a control section) for controlling the driving mechanism in accordance with a driving state of the engine.

Variable valve system for internal combustion engine and its driving mechanism

An oil pressure control apparatus which includes a source of hydraulic pressure introducing the hydraulic pressure to a hydraulic actuator which is actuated by hydraulic pressure, a fluid passage which is connected between the source of hydraulic pressure and the hydraulic actuator for introducing and discharging hydraulic pressure from the source of hydraulic pressure to the actuator, a control valve which is disposed in the fluid passages for controlling the hydraulic pressure and a filter is disposed in a position that is between the actuator and the control valve. Thereby, the control valve is capable to be operated smoothly.

Oil pressure control apparatus for an internal combustion engine

A valve timing control system has a tubular housing; a cam shaft having an external periphery formed with a drive cam; a phase variation mechanism disposed in the tubular housing, and varying a rotational phase of the sprocket portion relative to the cam shaft in accordance with oil pressure supplied to the phase variation mechanism; and an oil pressure control measures for controlling the oil pressure supplied to the phase variation mechanism. The tubular housing has a housing body having a density, and a sprocket portion for receiving a drive force transmitted from a crank shaft of an engine by way of a chain. The sprocket portion is disposed integrally to the tubular housing, and has a density higher than the density of the housing body. The tubular housing is so mounted to the cam shaft as to make a rotation relative to the cam shaft when so required.

Valve timing control system and method of producing valve timing control system

An oil pressure control apparatus for an internal combustion engine that has a source of hydraulic pressure and a hydraulic actuator which is actuated by hydraulic pressure provided via a fluid passage which is in communication with the source of hydraulic pressure. A control valve is disposed in the fluid passage for controlling the hydraulic pressure introduced to the actuator. A damper, which is disposed in a fluid communication between the hydraulic actuator and the control valve, is operative to attenuate the force of a pulsing stream of a working fluid in the fluid passage.

An internal combustion engine has a sprocket driven by a timing chain in synchronization with the engine rotation and a camshaft for driving intake or exhaust valves. A valve timing control device of the engine comprises a first rotating member on which the sprocket is integrally formed; a second rotating member capable of making a relative rotation to the first rotating member and rotated together with the camshaft; a plurality of working fluid chambers defined between the first and second rotating members; and a charging/discharging means for charging and discharging a working fluid to and from the working fluid chambers to induce the relative rotation between the first and second rotating members. The sprocket and at least a base part of the first rotating member on which the sprocket is integrally formed are constructed of a porous metal member. Thus, the working fluid led into the working fluid chambers is allowed to penetrate into the sprocket through the base part thereby to bring about a sufficient lubrication of a portion where the sprocket and the timing chain are meshed. The porous metal member may be a sintered metal.

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Zama, Japan

Akinobu Maeyama