Abstract: A joint structure of a steel pipe and a metal pipe includes a socket; and a thermosetting resin, the steel pipe including a first joining end having a flat portion of the outer surface of the first joining end adjacent to the base, and an uneven portion of the outer surface of the first joining end adjacent to the front end, the socket covering the first joining end, the metal pipe including a second joining end, the second joining end being interposed between the socket and the first joining end, the first joining end being joined to the second joining end by crimping while the thermosetting resin is present in the gap between the inner surface of the socket and the outer surface of the second joining end and between the outer surface of the first joining end and the inner surface of the second joining end.

Abstract: A structure connecting dissimilar metal tubes is a bellows tube and a metal tube made of stainless steel and aluminum respectively. The bellows tube has a reinforcement portion on its outer surface. The structure includes a nipple, the reinforcement portion, and a crimp collar fitted in that order to the outside of a straight tube portion of the bellows tube. The nipple is joined to the reinforcement portion and the metal tube. A sleeve is joined to the metal tube and the crimp collar. The nipple is bonded to the inner surface of the metal tube with a resin. End faces of the reinforcement portion and the crimp collar are in contact with or located close to an end face of the metal tube.

Abstract: A connection structure for connecting dissimilar metal tubes includes a metal bellows tube (A) having a reinforcement portion (3) disposed on the outer surface of the bellows (5), and a metal tube (B) composed of a material different from that of the bellows tube, the metal bellows tube (A) being integrally connected to the metal tube (B). A connection section on the bellows tube side includes a straight tube portion (1) of the bellows tube (A), a nipple (2), the reinforcement portion (3), and a crimp collar (4), being fitted and secured to each other in that order from the inside of the tube. The nipple (2) has a base (2-1) joined to the reinforcement portion (3) and a connection end (2-2) extending to the metal tube (B) side farther than an end face of the crimp collar (4).

Abstract: A joint structure of a steel pipe and a light metal pipe includes a socket; and a thermosetting resin, the steel pipe including a first joining end having a flat portion of the outer surface of the first joining end adjacent to the base, and an uneven portion of the outer surface of the first joining end adjacent to the front end, the socket covering the first joining end, the light metal pipe including a second joining end, the second joining end being interposed between the socket and the first joining end, the first joining end being joined to the second joining end by crimping while the thermosetting resin is present in the gap between the inner surface of the socket and the outer surface of the second joining end and between the outer surface of the first joining end and the inner surface of the second joining end.