Kabushiki Kaisha Riken

Honda Foundry Co., Ltd.

Kazuki Sato

Kazuyuki Fushimi

Yoshitaka Watanabe

A piston includes a piston body and a piston ring fitted into a ring groove. The piston ring has a top surface that includes: a convex portion formed between an inner edge position and a central position at which a radial direction thickness is &#xbd;, with the piston ring in a free state, and a planar portion or an inclined peripheral portion continuous with the convex portion on a radially outer side of the convex portion. In a predetermined status of the piston body and the piston ring, an angle between the top surface of the ring groove and the planar portion or the inclined peripheral portion is at least 18 arcminutes in a cross-section that is parallel to a central axis of the piston body and includes the central axis.

Growing community of inventors

Kashiwazaki, Japan

Kazuki Sato