| 摘要 |
PROBLEM TO BE SOLVED: To facilitate stage replacement when a work-piece diameter changes while alleviating damage of the outer peripheral surface of a work-piece and the inner peripheral surface of a through hole.SOLUTION: Seven endless movement members 4 are arranged at seven points excluding the arrangement position of a welding torch 6 out of a work-piece the periphery equally divided in eight. After being transmitted from a drive gear 942 to the lowermost transmission gear 931, the rotation of a drive shaft 941 of a motor 94 is transmitted to another transmission gear 931 via a ring gear 95, and seven transmission gears 931 rotate in the same direction at the same speed. The rotation of each transmission gear 931 is transmitted to a ball screw 92 the rotation axis of which is in a radial direction of the work-piece 100 by a driving side bevel gear 93 and a driven side bevel gear 91. The seven endless movement members 4 move in a direction where they are separated from or close to one another, thereby enabling a chain 41 to come in the peripheral surface of the work-piece 100 in response to changes in the diameter of the work-piece 100.SELECTED DRAWING: Figure 1 |
