| 摘要 |
PURPOSE:To improve the heat resistance of a piston by separating the crown of the piston into an inward part and an outward part made of the metal having the less thermal expansion coefficient than that of the inward part, in the radial direction, and by taper-fitting the both parts in the axial direction. CONSTITUTION:A bottomed cylindrical piston 1 is constituted by connecting an upper part crown 2 and a lower part skirt 3 which are formed as each single body, in the axial direction, and the crown 2 is constituted of an axial direction inward part 5 having a cavity 4 recessed in the axis center direction and a radial direction outward part 7 which is tapered-fitted in the axial direction for the outer peripheral surface 6 of the inward part 5. The inward part 5 is made of the casted iron which possesses the smaller thermal expansion coefficient and the superior heat resistance and the outward part 7 is made of the fiber-reinforced metal consisting of the reinforcing fiber and aluminum. The outward part 7 is integrally fixed onto the skirt 3 through the electronic beam welding, etc., in the state fitted with the inward part 5. |
