To provide a connection structure for connecting pipes in a telescopically extensible state while preventing the sticking of the pipes and ensuring smooth operation.
A small diameter rod (pipe) 2 has a rod body 2a and a fitting male part 2b formed at a butt end of the rod body 2a and having a diameter larger than that of the rod body 2a. The fitting male part 2b has a tapered form increasing the outer diameter toward the butt end and has a plurality of protrusions formed on the circumference by masking treatment. A large diameter rod 1 has a rod body 1a and a fitting female part 1b formed at the tip side of the rod body 1a and fittable with a fitting male part 2b inserted into the female part. A part of the tip end of the fitting male part 2b is exposed on the tip side relatively to the fitting female part 1b in the case of extracting the small diameter rod 2 toward the tip side of the large diameter rod 1 and fitting the fitting male part 2b into the fitting female part 1b.
TANIGUCHI KAZUMA
KAWASHIMA KOICHI
Kenichi Sui
Hidetada Kato