Abstract: In a valve operating apparatus, torque is transmitted from an eccentric drive cam attached to a drive shaft through a multinodular-link motion-transmission mechanism including a link arm, a rocker arm, and a link rod to a rockable cam to cause an engine valve to open and close. Also provided is a control cam whose geometric center is displaced from a control shaft. By way of eccentric rotary motion of the control cam, a valve lift of the engine valve is variably controlled. Lubricating oil supplied from an oil passage formed in the drive shaft via a first communicating passage formed in the drive cam into a clearance between the link arm and the drive cam, is forcibly fed via a second communicating passage into a pivotally linked portion between the link arm and the rocker arm by oscillatory pumping action created by eccentric rotary motion of the drive cam.

Abstract: A valve timing control system for an internal combustion engine has: a drive force transmitter or a chain sprocket; a cam shaft; a housing, a vane rotor; an advanced angle chamber and a delayed angle chamber; an oil pressure conveyer; a protrusion shaft; a target plate; and a sensor. The protrusion shaft is formed on at least one of the vane rotor and the housing, and protrudes forward. The target plate is mounted on at least one of the vane rotor and the housing. The target plate is formed substantially flat through a press molding, and is press fitted to the protrusion shaft. The target plate has a plurality of detector protrusions and one index protrusion. The detector protrusion and the index protrusion are equal in width.

Abstract: In a valve operating apparatus, torque is transmitted from an eccentric drive cam attached to a drive shaft through a multinodular-link motion-transmission mechanism including a link arm, a rocker arm, and a link rod to a rockable cam to cause an engine valve to open and close. Also provided is a control cam whose geometric center is displaced from a control shaft. By way of eccentric rotary motion of the control cam, a valve lift of the engine valve is variably controlled. Lubricating oil supplied from an oil passage formed in the drive shaft via a first communicating passage formed in the drive cam into a clearance between the link arm and the drive cam, is forcibly fed via a second communicating passage into a pivotally linked portion between the link arm and the rocker arm by oscillatory pumping action created by eccentric rotary motion of the drive cam.

Abstract: A valve timing control system for an internal combustion engine has: a drive force transmitter or a chain sprocket; a cam shaft; a housing, a vane rotor; an advanced angle chamber and a delayed angle chamber; an oil pressure conveyer; a protrusion shaft; a target plate; and a sensor. The protrusion shaft is formed on at least one of the vane rotor and the housing, and protrudes forward. The target plate is mounted on at least one of the vane rotor and the housing. The target plate is formed substantially flat through a press molding, and is press fitted to the protrusion shaft. The target plate has a plurality of detector protrusions and one index protrusion. The detector protrusion and the index protrusion are equal in width.

Abstract: A camshaft phase changing device has a pair of axially-spaced annular front and rear gears disposed and engaged between co-axial drive and driven members. An annular piston is mounted to the annular rear gear by a plurality of piston pins. The piston pins pass through openings of the rear gear toward the front gear. Each of the openings is dimensioned to provide a clearance around the corresponding one of the piston pins and keep the rear gear out of contact with outer surface of the corresponding piston pin.

Abstract: A variable intake- and/or exhaust-valve timing control system for an internal combustion engine comprises a cam sprocket having a driven connection with an engine crankshaft, a camshaft, a ring gear provided between the camshaft and the cam sprocket for adjusting a relative phase angle between the cam sprocket and the camshaft, and a ring gear drive mechanism for drivingly controlling the ring gear via fluid pressure created by an engine oil pump, depending upon the operating state of the engine. The drive mechanism includes a subsidiary oil pump for supplying a fluid pressure greater than a designated pressure level to the ring gear, during low engine speed and high engine load.

Abstract: An intake- and/or exhaust-valve timing control system for an internal combustion engine comprises a timing belt pulley having a driven connection with an engine crankshaft, a camshaft journaled by a bearing member mounted on a cylinder head and receiving torque transmitted from the timing belt pulley, a ring gear mechanism for adjusting a relative phase angle between the timing belt pulley and the camshaft. The valve timing control system includes a first hydraulic circuit provided for drivingly controlling the ring gear mechanism via fluid pressure depending upon the operating state of the engine and a second hydraulic circuit provided for lubricating frictional surfaces between the bearing member and the camshaft. The first and second hydraulic circuits are separated from each other. The valve timing control system includes a directional control valve connected to the first hydraulic circuit for switching the direction of working fluid flowing through the first hydraulic circuit.

Abstract: A valve timing adjusting system includes mutually parallel axial fluid paths both formed about a fastening bolt which engages with an axial bore formed at the end of a camshaft. One of the axial paths if formed through the fastening bolt and the other axial path is formed between the outer periphery of the fastening bolt and the inner periphery of the axial bore of the camshaft. This avoids necessity of formation of axial fluid path through the camshaft and thus redudes mashing step in production line to lead lower cost.