PURPOSE: To improve the abrasion withstandability at the ring groove section without sacrifice of the heat transmission performance, by constructing a portion for defining the wall of a ring groove which receives an engine piston ring with complex material.
CONSTITUTION: Two ring grooves 3, 4 for receiving a compression ring and a ring groove 5 for receiving an oil ring are formed in the outercircumferential face 2 at the side section of a piston 1 constructed of light metal such as aluminum alloy. A top ring groove 3 nearest to a piston head 6 has a wall face defined by a complex material where metal particle, metal fiber, non-metallic inorganic particle, inorganic fiber, etc. is employed as a reinforcing material while a light metal for consturcting a piston is employed as a matrix metal. Upper and lower width (a), (b) and the depth (c) of said complex material 7 is set shorter than approximately 5mm, to transmit the heat efficiently to a cylinder bore through a compression ring.
TOKUI MASAAKI
KATAYAMA HISAO
SUZUKI KOUJI
YOSHIDA HISATOSHI
