| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve processing accuracy by restricting the pipe decentering corresponding to the size of the pipe diameter so as to support the pipe center at a constant position. SOLUTION: Since a pushing up working shaft 33 being axially supported by a center supporting plate 31 on a work table is normal/reverse rotated, a right screw 35 and a left screw 37 are normal/reverse rotated. Thus, the first push up moving block 53 screwed with the right screw 35 and the second push up moving block 55 screwed with the left screw 37 are symmetrically synchronized and moved in a manner that they are approaching or separating each other. The first push up arm 57 and the second push up arm 59 being axially supported by the center supporting plate 31 are pushed up by each top end of the first push up moving block 53 and the second push up moving block 55, and the first supporting part and the second supporting part of the tip of each arm are rotated with a supporting point 61 of the center supporting plate 31 as a center in a manner that they are symmetrically approaching or separating each other. The pipe center arranged on the first supporting part and the second supporting part is always at the constant position.</p> |
