METHOD FOR FORMING SCROLL MEMBER

PURPOSE:To obtain a member having high dimension accuracy by providing a spiral groove having a taper on an end plate and fitting a spiral body into the groove, aligning the surface of the end plate of the opposite side of a projecting part with a pedestal, fitting a pressure punch having a recessed part corresponding to a shape of the spiral body to the projecting part, and pressing and forging the spiral body. CONSTITUTION:On the lower end side of a spiral body 1, a pedestal 4 provided with a spiral receiving groove 4 having a tapered part which expands upward, and an end plate 2 provided with a spiral groove 2a having a tapered part which expands downward are provided. The lower end side of the spiral body 1 is fitted into both grooves of an assembly formed by joining together wide sides of both grooves 2a, 4a, and a projecting part 1a of the upper side of the spiral body is fitted externally to a pressure punch 3 having a spiral recessed part 3a of high dimension accuracy. Subsequently, the spiral body 1 formed by winding a band-like plate material is fitted into the spiral groove 2a provided on the end plate and after heating them in a heating furnace, the end plate 2 and the pedestal 4 are allowed to abut on each other. Next, the pressure punch 3 to engaged to the projecting part 1a of the upper side and it is pressed, and the spiral body 1 is pressed against the spiral groove of the end plate. Thereafter, the pressure punch and the pedestal are removed and the projecting part of the lower part of the end plate is eliminated by machining, and a supporting axis 5 is attached.