Weld structure for refrigerant circuit component and welding method for refrigerant circuit component

A joining method for use with a refrigerant circuit component, the refrigerant circuit component including a connecting member and a casing part, which are joined to each other by projection welding, the connecting member having an inner hole connected to a pipe of a refrigerant circuit, and the casing part having an inner hole that communicates with the pipe via the inner hole of the connecting member, the joining method comprising:

• joining the casing part with the connecting member by projection welding such that a welded portion extends around an entire outer periphery of the inner hole of the casing part with a first gap being left between the welded portion and the inner hole of the casing part, and such that the welded portion extends around an entire outer periphery of the inner hole of the connecting member with a second gap being left between the welded portion and the inner hole of the connecting member;
• and
• crimping an opening end of one of the casing part and the connecting member around the inner hole thereof toward an opening end of the other of the casing part and the connecting member around the inner hole thereof to pressure-join the opening ends of the casing part and the connecting member and seal a spatter generation space inside the welded portion.