| 摘要 |
PURPOSE:To prevent entrance of combustion gas to a boundary part and to enable reduction of the manufacturing cost of a piston by a method wherein an annular member is situated to an outer peripheral part between a piston body and a top plate, and a top ring groove is formed in the outer periphery of the annular member. CONSTITUTION:A crown 1 made of ceramics is internally chilled by using an aluminum alloy by which a piston body 2 is formed. An annular member 3 is located at the outer peripheral part of a boundary between the crown 1 made of ceramics and the piston body 2 and in a position in the vicinity of a top land 5. A substance having a high length in the direction of the axis of a piston is used for the annular member 3, and a top ring groove 10 is formed in the outer periphery of the annular member 3. This constitution prevents entrance of combustion gas to a boundary part between the piston body and a top plate and enables reduction of a manufacturing cost. |
