| 摘要 |
PURPOSE:To produce a composite rough material for cylinder liners having different distributions in the abrasion resistance of the inside surface by putting a blank material of a concentrical composite disc wherein a blank material having high abrasion resistance in a metallic cylinder having plastic deformability into a die and pressurizing the same with a punch. CONSTITUTION:A hollow cylindrical body B is formed of a blank material having plastic deformability and abrasion resistance with some extent. A blank material A having excellent abrasion resistance is packed in the hollow part 4 of said cylindrical body to make a blank material M of a concentrical composite disc. The material M is put into a die 2 and the top end Ma of the material M is pressurized with a punch 1 in the upper part. The material M is extruded upward through the clearance 2a between the punch 1 and the die 2. In the initial period of the extrusion, the constituting materials A and B of the material M are extruded simultaneously. In the middle and late periods of the extrusion, the material having high plastic deformability deforms like Figure 6 in the section of a rough material P for a cylinder liner vessel, whereby the rough material for cylinder liners having particularly high abrasion resistance near the top dead point of the piston and having ordinary abrasion resistance in the other parts is obtained. |
