| 摘要 |
PURPOSE: To promote lightweight and improve the frictional characteristic of a contact surface with a piston by forming a sleeve constituting a partial cylinder inner surface with a thin metal plate provided with holes by means of punching, and covering the punching part with a layer being thermally formed by means of thermal spraying. CONSTITUTION: A perforated sleeve 16 to be inserted into respective cylinders of a cylinder block 10 of a multicylindered internal, combustion engine is manufactured by a steel plate of about 1 mm in thickness. The sleeve 16 is equipped with a punched part or thin piece 18 which is punched outward at an angleαof 45 deg. in the radial direction. Punching depth (t) of the thin piece 18 is made into about 3 mm, and the height (h) into 10 mm respectively, and further the thin piece 18 is formed into being shifted (angleβ) aslant in direction of a cylinder axis 22. Then, the sleeve 16 is made into being roughened of its surface by means of sandblasting, and after thermal spraying, a porous coated film consisting of cast iron solidified as a ledeburite (eutectic mixture between austenite and cementite) is applied to it. |
