CYLINDER SLEEVE AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a cylinder sleeve in which joining strength between a cylinder block and the cylinder sleeve is ensured and the abrasion resistance of an inner peripheral wall is excellent. SOLUTION: First, an outer cylindrical body 14 formed of an Al-Si-based alloy with a comparatively small difference in the coefficient of linear expansion from the cylinder block, for example, an ADC 12. Next, after a predetermined time elapses, and preferably, the temperature of the outer cylindrical body 14 becomes lower than a liquid phase-solid phase line in a phase diagram, an inner cylindrical body 12 is formed in a manner that molten metal L2 is introduced to the side of the inner peripheral wall of the outer cylindrical body 14 while continuously rotating a cylindrical die 22. The outer cylindrical body 14 functions as a cooling metal (a chiller) when the molten metal L2 is cooled and solidified. As the molten metal L2, for example, an Al-17 to 23% Si-based alloy is selected which is excellent in abrasion resistance in comparison with the Al-Si-based alloy forming the outer cylindrical body 14. COPYRIGHT: (C)2008,JPO&INPIT