A basic study on sheet metal forming method combined with joining process

为了通过板材的常规拉深来生产深杯形件，在拉深后的后续操作中需要在一个或多个阶段进行重新拉深和/或拉深。当这种多工步成形应用于超深杯形件的小批量生产时，随着产品数量的减少，工具成本变得相对昂贵。为了便于超深杯形件的小批量生产，本研究开发了一种与连接工艺相结合的成形新工艺。使用已开发的毛坯，其外围像花瓣一样被切割，而不是传统的圆形毛坯。这使得有可能降低毛坯的凸缘部分的拉拔阻力。借助于这一效应，很容易在一次拉深工序中生产出非常深的圆柱形、方形和锥形杯。然而，生产的杯子侧壁存在接缝，如何接合接缝是一个问题。接缝采用镶嵌金属、折叠或卷曲等机械接缝方法，同时进行杯侧壁接缝拉深和接缝。重点考察了压边机形状和展开毛坯形状对连接部变形行为的影响，明确了合适的工作条件。同时也证实了板料成形工艺与连接工艺相结合可以作为一种小批量生产超深杯形件的方法。

In order to produce a deep cup by conventional deep drawing of sheet metal, redrawing and/or ironing in one or more stages are necessary as the subsequent operation after the deep drawing. When such multi-stage forming is applied to the small lot production of very deep cups, tool cost becomes relatively expensive as the number of product decreases. And also, the lead time to the production can not be shortened.To facilitate the small lot production of very deep cups, in this study, a new forming process combined with joining process has been developed. A developed blank, the periphery of which is cut just like petals, was used instead of a conventional circular blank. This makes it possible to reduce the drawing resistance at the flange portion of the blank. By the aid of this effect, very deep cylindrical, square and tapered cups were easily produced in one drawing operation. However, there exist seams at the side wall of the cup produced and how to join the seams is a problem. To join the seams, mechanical seaming methods such as inlaid metalwork and folding or curling were adopted, and deep drawing and joining of seams at the side wall of the cup was carried out simultaneously. The effect of shapes of blank holder and developed blank on deformation behavior of joining portions was mainly examined and suitable working conditions were clarified. It is also confirmed that the sheet metal forming process combined with joining process can be used as a method to facilitate small lot production of very deep cups.