| 摘要 |
PURPOSE:To improve the combustion efficiency by permitting the uniform and speedy temperature rise of a surface part by forming a high thermal conductivity layer onto the surface part which is made of heat resisting material and faced to a combustion chamber in a piston body made of light alloy. CONSTITUTION:A piston is made of the light alloy containing Al and Mg as main constituents and equipped with a piston head part 10 having a combustion chamber at the center part, side surface part 20 which moves in sliding with the cylinder inner wall surface, and a hollow part 30 for holding a connecting rod. The wall of the combustion chamber is formed by fixing stainless steel plates 15 onto the top part of the piston by bolts 16, and an air gap 18 as a heat insulating layer is formed between the steel plates 15 and the piston body. With such structure, each high thermal conductivity layer made of the pure copper in the uniform thickness of 2mm is formed onto all the surfaces of the side wall part 101 and bottom wall part 102 on the combustion chamber in the piston head part 10 and the peripheral edge part 200 in the upper part of the combustion through plasma metallization. |
