Fuji Oozx Inc.

Nobuo Hara

Tatsuo Kanzaki

Makoto Abe

Akiyoshi Mori

Satoshi Fukuoka

Makoto Nagaya

A valve spring is used in a valve operating mechanism for moving a poppet valve up and down in an internal combustion engine of an automobile. The terminal end of the uppermost portion of the valve spring extends in a tangential direction to go away from an axis of the valve spring, thereby avoiding contact with a retainer to prevent wear.

Valve spring in an internal combustion engine

A tappet made of Al alloy is used in a valve operating mechanism of an internal combustion engine of a vehicle. On the whole outer circumferential surface of the tappet, a helical projection and a helical groove are formed alternately to form an uneven surface. A plurality of uneven surfaces are formed on a ridge of the projection at regular intervals. The outer circumferential surface is coated with a wear resistant Fe film by thermal spraying. The uneven surfaces on the projection provide high adhesion strength of the film to the outer circumferential surface of the tappet to improve peel resistance, thereby increasing durability and reliability of the Al alloy tappet.

Method of manufacturing a wear resistant cylinder

The lower surface of a valve spring retainer is engaged on a valve spring in a valve operating mechanism of an internal combustion engine. The valve spring retainer is subjected to T6 treatment under JIS (Japanese Industrial Standard), and machined as finishing. The lower surface of the valve spring retainer is not machined, and remains as subjected to T6 treatment, thereby improving fatigue strength and wear resistance.

Aluminum alloy valve spring retainer and method of making same

Wear resistant tappet

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.

Method of manufacturing a tappet in an internal combustion engine

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.

Light metal tappets have been widely used in an internal combustion engine instead of conventional steel tappets. On the upper surface of a top wall of a body, a wear resistant cam receiving plate is put, and a projection of the cam receiving plate is engaged in a groove of the top wall, so that the cam receiving plate is integrally connected with the body, thereby making the tappet smaller and lighter.

Tappet in an internal combustion engine and a method of manufacturing

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.

Tappet in an internal combustion engine and a method of manufacturing it

In a tappet for use in an internal combustion engine, a tip is fitted in an engage bore between the top wall of the tappet and an engine valve shaft. The tip has a chamfered portion over which a circumferential projection is pressed by a punch so as to fix the tip in the engage bore firmly. A caulking groove is formed by the punch around the engage bore on the top wall. Owing to the chamfered portion of the tip, a cracking is prevented at the bottom of the groove.

Method of securing a tip in a tappet

To manufacture an Al alloy tappet in an internal combustion engine, an intermediate which has a circular upper wall and a cylindrical skirt is formed in the first forging step. In the second forging step, a recess is formed on the lower surface of the upper wall. Relatively large-sized metallic structure in the first forging step is finally collapsed, thereby increasing strength and rigidity of the upper wall around the recess.

Method of forming a tappet body in an internal combustion engine

A method of manufacturing a tappet used in a valve operating mechanism of a direct acting type in an internal combustion engine. A tip engaged with a center bore of an inner upper surface of a tappet body includes upper and lower convex surfaces and a rounded upper circumferential corner having a certain curvature. thereby preventing concentration of stress even if the tip is subject to high compression load. Thus, durability and reliablity of the tappet are increased.

Method of manufacturing a tappet for an internal combustion engine

A tappet is used in a valve operating mechanism of a direct acting type in an internal combustion engine. A tip engaged with a center bore of an inner upper surface of a tappet body comprises upper and lower convex surfaces and a rounded upper circumferential corner having a certain curvature, thereby preventing concentration of stress even if the tip is subject to high compression load. Thus, durability and reliablity of the tappet are increased.

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Fujisawa, Japan

Nobuo Hara