Abstract: An apparatus for simultaneously measuring the thickness of a bottom wall and the inside diameter of a bottoming hole. The apparatus includes a measurement auxiliary unit; a measurement head removably mounted at a lower end portion of the measurement auxiliary unit, the measurement head having an outside diameter fittable in a bottoming hole of a workpiece such as a tappet; a nozzle, provided in the measurement head, for jetting outward a compressed air supplied from an air micrometer; and an electric micrometer, provided over the measurement auxiliary unit, for detecting a vertical displacement of the measurement auxiliary unit.

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 in an internal combustion engine comprises a cylindrical body and a cam receiving plate on the top wall of the cylindrical body. To manufacture the tappet by forging, light metal material is provided on the surface which has a groove of the cam receiving plate, and forged in a die to mold the body and to connect the body with the cam receiving plate by a single step, thereby decreasing the number of mechanical steps and cost.

Abstract: A steel for exhaust valves comprises C: 0.50-0.65 wt %, Si: 0.1-0.3 wt %, Mn: 5.0-8.0 wt %, Cr: 22.0-24.0 wt %, Ni: 5.0-7.0 wt %, Cu: 0.4-1.0 wt %, Mo: 0.4-2.0 wt %, W: 0.4-2.0 wt %, Nb: 0.4-2.0 wt %, Ti: 0.1-0.3 wt %, N: 0.35-0.50 wt %, sol. Al: 0.005-0.03 wt %, B: 0.001-0.01 wt %, provided that (Cu+Ni): 5.8-7.6 wt %, and the balance being Fe and inevitable impurities and has excellent high-temperature strength, corrosion resistance at room and higher temperatures and oxidation resistance.

Abstract: Between the end of a valve and a valve-operating cam in an internal combustion engine, a valve lifter is inserted. A filler enclosing portion is formed between a shim and the body of the valve lifter. Through an opening from an injector, a filler is introduced into the filler enclosing portion, so that valve clearance is corrected to zero. Differences in valve clearance can be easily corrected.

Abstract: A method of manufacturing a tappet which is used in an internal combustion engine of vehicles is provided. A core material of the tappet has a helical groove on the outer circumferential surface, and a wear resistant coating layer, the ends of which are chamfered. In the vicinity of the end of the core material the helical groove gradually becomes small toward the end, thereby preventing peaks of the helical groove from exposure to the outside.

Abstract: To manufacture a tappet in an internal combustion engine, a tappet rough body which comprises a cylindrical portion with an upper wall and an annular side wall is moulded by press processing of metal powder, such that the upper wall, the cylindrical portion and the annular side wall become larger than the tappet to be manufactured in the axial size. After sintering the tappet rough body, it is re-compressed to form the final tappet.

Abstract: Between the end of a valve and a valve-operating cam in an internal combustion engine, a valve lifter is inserted. A filler enclosing portion is formed between a shim and the body of the valve lifter. Through an opening from an injector, a filler is introduced into the filler enclosing portion, so that valve clearance is corrected to zero. Differences in valve clearance can be easily corrected.

Abstract: In a conductive plate of an upper electrode of an electric gathering apparatus for manufacturing a poppet valve used in an internal combustion engine, there is formed a polygonal bore in which a drive shaft is engaged. An annular cut-away portion which is larger than the engagement bore in diameter is formed, thereby preventing a burr and increasing durability of the electrode.

Abstract: An exhaust gas control device is provided in an internal combustion engine. In the device, a valve which comprises a valve head and a valve stem is provided in a body the axis of which is inclined at 45 degrees with respect to a horizontal exhaust pipe. The valve is moved up and down in the body by compressed air and a coil spring. When the valve is engaged on a valve seat in the exhaust pipe, the exhaust pipe is closed, so that exhaust gas flows through a by-pass pipe. When the exhaust pipe is opened, exhaust gas flows through the exhaust pipe, thereby improving engine performance.

Abstract: A workpiece is processed to manufacture a poppet valve comprising a larger diameter head and a stem. First, the stem is ground to correct bending and warping and to remove black skin formed by a mold releasing agent, and, then the stem of the workpiece is cut, thereby preventing variation of the total length and wear of support rollers.

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: An intake valve in an internal combustion engine comprises a valve stem and a valve head and moves up and down. On either of contact surfaces between the valve stem and a valve guide, annular and elongate grooves are formed to communicate with an intake port at the lower end. Lubricating oil invaded into a gap between the valve stem and the valve guide goes down through the grooves, gets out of the valve guide and adhere onto the valve head in the intake port. The oil on the valve head is washed down by fuel injected from a fuel injector.

Abstract: There is provided a coil retainer for an engine valve to be mounted therewithin, said retainer prepared by forging of an aluminum-based alloy of the following composition; followed by special combined heat treatments to convert into an alloy material having a dendrite arm spacing value less than 15 micrometer; and the composition being composed ofSilicon: 8 to 17 weight percent;Copper: 2 to 5 weight percent;Magnesium: 0.2 to 10 weight percent;Manganese: 0.1 to 1.5 weight percent;the balance of the composition being aluminum and inevitable amount of impurities.

Abstract: There is provided an internal combustion engine valve having a body, a head, and a contact surface disposed on a head surface to be adapted to periodically enter into gas-sealing engagement with a valve seat, said contact surface being formed in alloy deposit welded to said valve head, by a high density energy beam such as a plasma beam or a laser beam, on said head surface, a cobalt based composition of said alloy deposit, measured at said contact surface, consisting essentially ofcarbon: 2.2 to 2.6 weight percent;silicon: 1.1 to 1.3 weight percent;manganese: 2.6 to 3.1 weight percent;nickel: not more than 1.5 weight percent;chromium: 28 to 31 weight percent;iron: 10 to 11 weight percent;tungsten: 13.5 to 15.5 weight percent;balancing cobalt and inevitable amount of impurities.

Abstract: A tappet in a direct acting type valve operating mechanism of an internal combustion engine comprises a top wall and a cylindrical portion. The upper and lower surfaces of the top wall contacts a rotary cam and the end of a stem of an engine valve respectively. A hard metal layer is formed at the upper and lower surfaces of the top wall to increase strength thereof, thereby increasing wear resistance and durability of the tappet.

Abstract: A tappet is used in an internal combustion engine of vehicles. A core material of the tappet has a helical groove on the outer circumferential surface, and a wear resistant coating layer the ends of which are chamfered. In the vicinity of the end of the core material, the helical groove gradually becomes smaller toward the end, thereby preventing peaks of the helical groove from exposure to the outside.

Abstract: A shim for a tappet is used in a valve operating mechanism in an internal combustion engine. On the surface of the shim which a cam slidably contacts, there are provided a number of bores in which lubricating oil is put. When an oil film disappears on the surface by slidable contact with the cam, oil overflows from the bores onto the surface. By increasing oil-keeping capability on the surface of the shim, frictional resistance is reduced, thereby preventing wear in the shim and the cam. The bores may be filled with a lubricating solid such as molybdenum disulfide or plastics, such as polyethylene, silicone and Teflon.RTM.. The diameter of the bores may become larger as the bores extend away from the surface of the shim, thereby preventing the solid material from being displaced from the bores. The density of the bores on the shim surface can also be varied. The density of the bores in the central area of the shim surface can be greater than in the surrounding area.

Abstract: With vertical movement of a valve in an engine, a suspending member which suspends from a retainer engaged in the valve goes up and down with respect to a standing member on a cylinder head. A projection provided on the suspending member slides on inclined guide surfaces of the standing member, thereby attaining relative rotation of the suspending member forcibly with respect to the standing member, so that the valve is rotated on its axis.

Abstract: A stem and a valve face of an engine valve are ground by first and second grinding wheels respectively. A motor for driving the second grinding wheel is mounted on a first plate movable by a servomotor in a direction perpendicular to the axis of the wheel, and under the first plate, a second plate is disposed to be movable in a direction parallel with the axis of the wheel. The valve face is ground obliquely by the second grinding wheel by moving the two plates. The first grinding wheel is trued by a first dresser movable in directions parallel with and perpendicular to the axis of the first grinding wheel. The second grinding wheel is trued by a second dresser provided at the end of a support strut.