Abstract: A method of die-casting a die-cast article having at least one of an inner circumferential surface and an outer circumferential surface, whose cross sectional shape is a circle, the die-casting article being formed with a die-casting apparatus having a mold cavity therein and a molding portion for forming one of the inner and outer circumferential surfaces of the die-cast article, the method comprising the steps of introducing a molten metal into the mold cavity; and separating the die-cast article and the molding portion from each other while the die-cast article and the molding portion are rotated relative to each other, after the molten metal has solidified into the die-cast article. A die-casting apparatus for practicing the method is also disclosed.

Abstract: An apparatus for casting a scroll member of a compressor has a first die and a second die. The first die includes a molding surface for molding a base plate of the scroll member. The second die includes a molding surface for molding a scroll wall of the scroll member. The first and second dies define a cavity for casting the scroll member. The first die also includes a first die-member and a second die-member. The second die-member forms a portion of the scroll member, which extends in a direction substantially perpendicular to a direction in which the first and second dies separate from each other.

Abstract: A scroll type compressor has a fixed scroll member and a movable scroll member. The fixed scroll member has a fixed scroll base plate and a fixed scroll wall extending from the fixed scroll base plate. The movable scroll member has a movable scroll base plate and a movable scroll wall extending from the movable scroll base plate. The fixed scroll member and the movable scroll member cooperatively form a compression region. The movable scroll member orbits relative to the fixed scroll member to compress refrigerant in the compression region. Each scroll wall is formed in a taper shape from each base plate toward each distal end of the scroll wall. The distal end is non-contact with the opposing scroll base plate. Clearance between the distal end and the opposing scroll base plate is less than or equal to the limit clearance value which maintains airtight performance.

Abstract: A scroll material 160 for the production of a scroll is cast, a scroll portion 54 thereof is left as cast, and the portions other than the scroll portion 54 are machine-worked. Positioning portions 168, 169, and 170 and an engagement hole 172 are cast together with the scroll portion 54 of the scroll material 160, etc., in a die-casting process. In a machine working process, an engagement portion 248 of a holding jaw 234 is engaged with the engagement hole 172 of the positioning portion 168 and at the same time the positioning portions 168, 169, and 170 are held with the holding jaws 234, 236 and 238 of a chuck 230. In this state, the outer side surface of the base 162 opposite to the scroll portion 54, etc., are cutting-worked with work tools. Using the positioning portions 168, 169, and 170 as the work basis is almost equal to using the scroll portion 54 as the work basis, and a movable scroll, having a high relative positioning accuracy between the scroll portion 54 and other portions, can be manufactured.

Abstract: A scroll type compressor has a fixed scroll, a movable scroll and a plurality of sealing members. The fixed scroll includes a fixed base plate and a fixed volute portion, which is formed on the fixed base plate. The fixed volute portion is tapered and the corners of the proximal end of the fixed volute portion are arched. The movable scroll is arranged to be engaged with the fixed scroll. The movable scroll includes a movable base plate and a movable volute portion, which is formed on the movable base plate. The movable volute portion is tapered and the corners of the proximal end of the movable volute portion are arched. One of the sealing members is located on the fixed base plate. The other of the sealing members is located on the movable base plate.