Unisia Jecs Corporation

Hitachi Unisia Automotive, Ltd.

Hirokazu Uehara

Seiji Tsuruta

Noriomi Hosaka

Noboru Egashira

Tamotsu Todo

Akira Hidaka

Akio Akasaka

Shin Koizumi

Nobutaka Hayashi

Akira Torii

A valve-lash adjuster equipped valve operating device for an internal combustion engine includes a biasing device biasing an engine valve in a valve-closing direction, and a valve drive mechanism opening the engine valve against the spring bias of the biasing device. A hydraulic zero lash adjuster is disposed between the engine valve and the valve drive mechanism to provide zero valve lash. A restriction device is provided to restrict a compressive force applied from each of the engine valve and the valve drive mechanism to the zero lash adjuster, when the engine is stopped.

Valve-lash adjuster equipped valve operating device for internal combustion engine

A relative angular phase between a timing sprocket,and a camshaft,is changed by rotating a vane rotor,in a normal-rotation direction or in a reverse-rotation direction by way of relative application of hydraulic pressure to one of a timing-advance phase hydraulic pressure chamber,and a timing-retard phase hydraulic pressure chamber,both defined in a housing,and relative release of hydraulic pressure from the other of the hydraulic pressure chambers, in order to vary the opening and closing timing of an intake valve. A restricting mechanism,is also provided for reverse rotation of the vane rotor, which may occur during rotating from the timing-retard phase to the timing advance phase owing to a positive fluctuating torque of the camshaft. In the restricting mechanism, a plunger,is projected outward by way of a hydraulic pressure supplied to a high-pressure chamber,, so that the plunger is constantly in abutted-contact with one side wall,, and whereby the plunger,produces a pushing a force or thrust by virtue of a check valve,, so as to counteract the positive fluctuating torque. A turning-back phenomenon of the vane rotor can be restricted in presence of torque fluctuations of the camshaft during rotation of the vane rotor, thus enhancing the responsiveness of valve timing control.

Valve timing control device of internal combustion engine

A decompression brake device comprises a valve drive mechanism for driving an exhaust valve of an internal combustion engine. The valve drive mechanism has first, second and third conditions, the first condition being a condition wherein the exhaust valve assumes a fully closed rest position during intake, compression and expansion strokes of the engine and a full open position during an exhaust stroke of the engine, the second condition being a condition wherein the exhaust valve assumes the fully closed rest position during the intake stroke of the engine, a slightly open rest position during the compression and expansion strokes of the engine and the full open position during the exhaust stroke of the engine, and the third condition being a condition wherein the exhaust valve assumes the fully closed rest position during the intake stroke of the engine, a largely open rest position during the compression and expansion strokes of the engine and the full open position during the exhaust stroke of the engine. An actuator is used, which has a hydraulically actuated rod which has first, second and third positions to cause the valve drive mechanism to assume the first, second and third conditions respectively. A hydraulic circuit is used for feeding or drawing a pressurized oil to or from the actuator to move the rod to one of the first, second and third positions.

Decompression brake device of automotive internal combustion engine

A valve lifter and processing method therefor include a valve lifter surface to be installed in a recess of a cylinder head of an internal combustion engine. The method includes a grinding step for beveling, or tapering, the circumferential end of a cylindrical wall portion of the valve lifter which slidingly contacts the recess. Excess material resulting from the beveling process is then removed for smoothing the beveled circumferential end. The smoothed surface is then coated with a hardening layer for abrasion protection and smoother operational movement. As a final step, the hardening layer may be polished for further enhancement of operating performance.

Valve lifter surface and processing method thereof

In a decompression braking apparatus which is applicable to a Diesel engine and is capable of switching an engine braking condition so as to achieve an engine revolution speed area when a decompression braking request is issued, a sleeve portion of an eccentric bushing member is pivotally interposed between an inner periphery of a rocker arm and an outer periphery of a rocker shaft fitted into the rocker arm so as to be enabled to displace a swing center of the rocker arm toward a downward direction aligned with an open direction of an exhaust valve whose degree of openings in a closure stroke thereof is varied, a first actuator is so constructed and arranged as to actuate the eccentric bushing member to be pivoted so that the swing center of the rocker arm is displaced to a second position at which the degree of openings of the exhaust valve in the closure stroke is relatively large and a second actuator is so constructed and arranged as to limit the pivotal movement of the eccentric bushing member according to the actuation by means of the first actuator so that the swing center of the rocker arm is displaced to a first position at which the degree of openings of the exhaust valve during the closure stroke is relatively small.

Decompression braking apparatus for diesel engine

In a decompression braking apparatus which is applicable to a Diesel engine and is capable of switching an engine braking condition so as to achieve an appropriate braking force depending upon an engine revolution speed area when a decompression braking request is issued, an eccentric bushing member is pivotally interposed between an inner periphery of a rocker arm and an outer periphery of a rocker shaft fitted into the rocker arm so as to be enabled to displace a swing center of the rocker arm to a first position at which a degree of openings in a closure stroke of an exhaust valve whose valve stem is linked to the rocker arm is relatively small and to a second position at which the degree of openings in the closure stroke thereof is relatively large and an actuator having a plunger linked to the eccentric bushing member hydraulically actuates the eccentric bushing member to pivot so that the swing center of the rocker arm is displaced to either of the first or second position depending on an engine revolution speed when a decompression braking request is issued.

A valve lifter of a valve mechanism for an internal combustion engine is provided with a crown-shaped valve lifter body which has a center plate with a recess. A fixing projection is integrally formed with the center plate and is formed along a side wall which defines the recess. An inner shim of a disc shape has a plurality of grooves to which the fixing projection is filled by caulking the fixing projection for fixedly connecting the inner shim with the valve lifter body. Therefore, the inner shim is easily and securely assembled in the recess of the valve lifter body so as not to generate the looseness between the inner shim and the valve lifter body while the assemble performance is improved.

Growing community of inventors

Atsugi, Japan

Hirokazu Uehara