To provide a low-cost cast connection part for a water passage member providing low risk of water leakage.
This connection structure of a water passage member has a first water passage member having a first connection part to a second water passage member having a second connection part. By water-tightly connecting the first connection part and the second connection part, at least one water passage is formed by the first water passage member and the second water passage member. The first connection part is cylindrical and has a first collar portion and a seal member on the outer periphery. The second connection part is cylindrical and has a contact part cut for contacting with the seal member and sealing for water in the inner surface and a second collar part and a cut portion on the outer periphery. When connecting, the structure has a pinching member for pinching and fixing the first and second collar parts. The second water passage member is cast, and an as-cast portion is provided to a position opposing to a cylindrical part outside surface of the contact part.
NISHIYAMA TOSHIYUKI
ENOKI MASATOSHI
YAMAURA TOMOAKI
OTANI SACHIKO
