To provide an air injection device for a polishing jig, which has high sealability, is not likely to come off from a body of an injection port member, and is provided with an inexpensive sealing member.
The device is provided with the injection port member 4 to be inserted into an air injection port 16 of the polishing jig 2. The injection port member 4 is provided with a cylindrical body 33 and the sealing member 34 attached to an outer peripheral part of the body 33. The outer peripheral part of the body 33 has a peripheral wall 42 parallel to an outer peripheral surface 33a of the body 33, and an annular groove 41 having a pair of side walls 43 and 44 extended radially outward from the peripheral wall 42. The sealing member 34 is formed in an annular shape which extends all over a circumferential direction of the annular groove 41 by an elastic body, and inserted into the annular groove 41. An outer diameter of the sealing member 34 is made larger than an inner diameter of the air injection port 16. A gap S to be sealed by the elastically deformed sealing member 34 is formed between the sealing member 34 and the annular groove 41.
TAJIMA MAKOTO
KATAGIRI KAZUHIKO
Shigeki Yamakawa