| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a gear in which outer teeth are formed at an external peripheral wall, and inner teeth are formed at an internal peripheral wall, and which is excellent in dimension accuracy.SOLUTION: An upper end of a spline punch 50 is made to penetrate a penetration hole of a work 24. Next, a cope 28 is descended, a pressing sleeve 94 is made to abut on the work 24, and finish processing is applied to dog teeth 20 by a dog tooth processing punch 82 while keeping a position of the pressing sleeve 94, and prohibiting the descending of a die sleeve 62 under the action of a gas spring. After that, the cope 28 is further descended, the work 24 is pressed by the pressing sleeve 94 in a state that the work 24 is constrained by the dog tooth processing punch 82, and a load exceeding a set load of the gas spring is imparted. As a result, a buffer rod of the gas spring is descended and the die sleeve 62 is descended, and furthermore, the work 24 is descended along the spline punch 50. At this time, a spline is formed at an internal peripheral wall of the work 24.</p> |
