| 摘要 |
PURPOSE:To obtain the captioned bushings with a crush relief at high performance by beforehand inscribing depressions to the intended cutting places of a strip form blank and cutting the blank thence curving the blank with the depression being positioned on the inner side. CONSTITUTION:In cutting out square blank pieces 3 at the spacing equal to the circumferential length of the bushing from a strip form blank 1, depressions 2 of a narrowest possible width are beforehand inscribed in the intended cutting places C.l. by pressing or cutting, after which it is cut. Next, when it is curved to circular cylindrical form with the depression being positioned on the inner side and the cut end edges are butted, then the bushing 5 provided with a crash relief 4 is formed. Since this method does not require accurate positioning of the cut places and the correction of the relief groove after butting, it considerably improves the working efficiency. |
