Fuji Kihan Co. Ltd.

Art Metal Mfg. Co., Ltd.

Hiroshi Narusawa

Yoshio Miyasaka

Tsutomu Sakai

Nobuyuki Fujiwara

A piston allowing a lubrication layer of a resin coating with a low friction coefficient to be tightly adhered to a skirt portion of a piston for an internal combustion engine, with low friction, superior wear resistance, and superior anti-seizing properties and that can reduce wear of a cylinder inner wall even if the lubrication layer is peeled off or abraded, is provided. Metal or ceramic fine particles having an average particle diameter of 20 &#x3bc;m to 400 &#x3bc;m are injected with compressed air or compressed nitrogen as a mixture fluid onto the skirt portion of the piston, made of an aluminum alloy and produced by a method such as casting or forging, at an injection speed of 80 m/s or more or an injection pressure of 0.2 MPa or more to be collided with the skirt portion, thereby uniformly making a microstructure of a piston base material fine-grained in a depth range of 1 &#x3bc;m to 15 &#x3bc;m from a surface of the skirt portion and forming a modified layer with an activated surface. A lubrication layer is formed on the modified layer, for example, by applying a resin with a low friction coefficient, while a surface of the modified layer is being activated.

Growing community of inventors

Ueda, Japan

Hiroshi Narusawa