Scroll manufacturing method and tool

Abstract

A method and tool for manufacturing a scroll for use in a scroll type fluid displacement apparatus is disclosed. The method, which uses the tool of the present invention, comprises the steps of: (a) providing a tool formed by a mold including a first molding member having a first involute element and an end plate having a plurality of arc shaped holes; a second involute element rotatably coupled to the first molding member through a plurality of pins axially projecting from an axial end surface thereof, the first and second involute elements forming a radial gap; a rotatable member disposed along the end surface of the end plate of the first involute element and coupled to the pins of the second involute element to transmit the rotation thereof to the second involute element; and a second molding member to cover the open end of the radial gap, the second molding member having an indentation facing and in communication with the open end of the radial gap; (b) filling the radial gap between the first and second involute elements and the indentation with molten metal to form the molten metal into the shape of the spiral element and end plate of the scroll, (c) rotating the rotatable member to enlarge the radial gap after the molten metal solidifies; and (d) removing the scroll formed in the radial gap and the identation from the first molding member.