Piston, method of producing the piston, and pump having the piston

摘要

A piston 1 which is to be movably supported in a cylinder 11 of a pump 10 to be reciprocally driven is formed by a fluororesin so that it is not impaired by a corrosive liquid. A cylindrical outer peripheral portion 2 of the piston 1 has a thickness of 1 mm or less, and is flexible. The outer peripheral portion has a flange portion 7 in an open end portion via an approximately 180-degree folded-back portion 3. The flange portion 7 is attached to the cylinder 11. When the pump 10 is driven, the cylindrical outer peripheral portion 2 of the piston 1 smoothly rolls without producing deflections or bends in a gap between the outer peripheral face of a piston support member 15 and the inner peripheral face of the cylinder 11, while being in close contact with the two faces.