PISTON FOR FLUID MACHINE AND MANUFACTURE THEREOF

PURPOSE:To hold a slide gap between a cylinder bore and a piston with high precision by providing a piston comprising a connecting part made of a metal with which a piston rod is engaged and a piston body part made of resin of which a connecting part is insert-casted. CONSTITUTION:A fluid mechanism, such as a swing swash type compressor, used in an air-conditioning device, is formed such that a piston 12 is engaged internally of a cylinder bore 11 formed in a cylinder block 10 and the piston 12 is connected to a swing plate, not shown, through a piston rod 13. In this case, the piston 12 comprises a connecting part 20 made of a metal, such as an aluminum alloy, and a piston body part 30 made of resin, such as fluororesin. A spherical part 13a of the piston rod 13 is engaged with a caulking part 22, protruded axially from a disc part 21 of the connecting part 20, by caulking, and the piston body part 30 made of resin is formed such that the connecting part 20, except a caulked part 22, is insert-casted thereof.