Abstract: A poppet valve which has a valve stem is moved up and down to open and close a valve port in an internal combustion engine of a vehicle such as an automobile. A moving coil is wound on a bobbin mounted to the valve stem, and a magnet is mounted to a yoke fixed to a cylinder head. A plurality of sensors detect working conditions of the engine to send a signal to a working condition discriminating portion of CPU. The signal is further sent to a valve timing lift pattern memory in which optimum valve timing and lift are set corresponding to the working conditions to generate an optimum valve position signal. In the meantime, an actual position of the valve is detected by a sensor on the yoke to send an actual valve position signal to a valve position detector.

Abstract: A poppet valve is provided to open and close a valve seat in an internal combustion engine. At the end of a valve stem of the valve, a cylindrical support is fixed, and on the outer circumferential surface of the support, a moving coil is wound. There is formed an annular cavity in a yoke fixed to a bracket fixed on a cylinder head, and a permanent magnet is fixed in the annular cavity of the yoke. Between the permanent magnet and the yoke in the annular cavity, the support which has the moving coil is inserted. By a control system having CPU, an electric current is applied to the moving coil, thereby providing optimum valve timing and lift to decrease seating noise and improving engine performance.

Abstract: A soldering layer is formed on a valve guide or valve seat and/or a holding bore of a cylinder head in an internal combustion engine. The solder can be melted below the highest temperature which the valve guide or valve seat reaches during operation of the internal combustion engine. The valve guide or valve seat is a press fit in the holding bore of the cylinder head, and with operation of the internal combustion engine, the soldering layer is melted to close gaps on the contacting surfaces between the holding bore and valve guide or valve seat. The soldering layer finally has a higher melting point than the highest temperature of the valve guide or valve seat as above. During operation of the engine, the soldering layer is not melted.

Abstract: A hollow valve is used as an inlet or exhaust valve in an internal combustion engine. A hollow valve has a valve head and a valve stem. A cavity extends from the valve head to the valve stem. A low melting point alloy in solid is inserted into the cavity and occupies 1/4 to 1/3 of the cavity in volume. During operation of the engine, the alloy is melted, thereby cooling the valve.

Abstract: A tappet is used in an internal combustion engine. A cam receiving plate which contacts a cam is brazed on the upper surface of a top wall of a tappet body. The whole surface of the cam receiving plate can act as a cam follower surface, thereby making the outer diameter of the cam receiving plate to the minimum size corresponding to projected length of a nose of a rotary cam and lightening the tappet.

Abstract: In a pressure fluid control valve device, the fluid exhausted from an internal combustion engine flows through a pair of paths selectively or simultaneously. Each of the paths is opened and closed by a butterfly valve fixed to a valve shaft. A coupling for connecting the valve shafts across the paths comprises a slitting recess and a projection provided at the opposing ends of the valve shafts respectively. The direction of the surface of the recess and the projection is set to within 30 degrees with respect to the direction of the surface of the valve disc fixed to the valve shaft having the recess. Thus, the corner of the recess is not engaged with the bearing surface which is loaded, thereby making axial length for connecting the valve shafts to zero to manufacture the light and compact device.

Abstract: A shim attaching/detaching tool for a tappet of an internal combustion engine includes as essential components an air supplying tube, an air blowing tube and a nozzle formed at an opening portion of the air blowing tube at the foremost end of the same. When compressed air is blown from the nozzle toward the shim while the air supplying tube is inclined at an angle of about 45 degrees and the nozzle is oriented toward the fitting portion of the shim fitted into a circular cavity, the shim is thrusted against the opposite side of the cavity and the compressed air is then introduced into the space below the shim through the gap appearing around the fitting portion of the shim, whereby the shim is floated up away from the cavity so as to enable it to be easily exchanged with another shim having a different thickness.