| 摘要 |
PROBLEM TO BE SOLVED: To generate no crack at working a brittle material and easily work even in case of a work piece of small diameter by supplying air into a balloon so as to swell out, and pressing the back of a grinding tool. SOLUTION: A balloon 3 capable of being expanded and contracted is arranged in a space 2b so as to contact with the back of a wheel spindle stock 6, and the balloon 3 is adheringly fixed to the back of the stock 6. When the balloon 3 is expanded, the stock 6 is pushed on the left side and the working surface of a grinding tool 5 is projected from a supporting shaft 2, and when it is contracted, the grinding tool 5 is received in the space 2b. The fixing member 8 of the balloon 3 is fixed to the supporting shaft 2, fixed to the extreme end of a hollow conduit tube 4 inserted into an inserting hole 2a, and the interior of the balloon 3 is communicated to the interior of the conduit tube 4. An air supply device is connected to the opposite side of the conduit tube 4 against the balloon through a regulator. Hereby, because pressing pressure can be set by the air pressure supplied to the balloon 3, pressing pressure suitable for working of a brittle material can be optionally set. |
