主权项 |
1. A method of manufacturing a scroll member for a compression mechanism installed in a scroll compressor, the method comprising
a casting step including forming an iron casting including a fixed part, a spiraling part extending axially from a side of the fixed part in a spiraling formation, and a protruding part fixed to the fixed part on a side opposite to the side with the spiraling part extending therefrom, with the protruding part having an annular shape encircling a center of the spiraling part; and a cutting step including cutting the iron casting obtained in the casting step along the spiraling formation in order to obtain a final shape of the scroll member, the fixed part of the iron casting obtained in the casting step including a central portion with a first axial thickness and an external periphery portion with a second axial thickness larger than the first axial thickness, the central portion being radially closer to the center of the spiraling part than the external periphery portion, and the external periphery portion being positioned externally of the protruding part when the iron casting is viewed axially, a dimension of a specified portion along a thickness direction of the spiraling part being larger before the cutting step is performed than after the cutting step is performed, the thickness direction being transverse to a direction of the spiraling formation and an axial direction, the specified portion of the spiraling part extending along the spiraling formation from an end on an external periphery of the spiraling part to a position different from an end at the center of the spiraling part, the center of the spiraling part being a circumferential center of the scroll member as viewed along the axial direction, the end at the center of the spiraling part having a same dimension along the thickness direction before and after the cutting step, and the dimension of the specified portion along the thickness direction before the cutting step being larger than the dimension of the end at the center of the spiraling part along the thickness direction before the cutting step, wherein the dimension of the specified portion and the dimension of the end at the center being measured at a same height of the spiraling part along the axial direction. |