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

为了通过传统的金属板深拉伸生产深杯，在深拉伸后的后续操作中，需要在一个或多个阶段进行重拉伸和/或熨烫。当这种多段成形应用于小批量极深杯的生产时，随着产品数量的减少，刀具成本变得相对昂贵。而且，生产的交货期也不能缩短。为了方便小批量生产深杯，本研究开发了一种新的成形与连接相结合的工艺。一个发达的空白，其外围被切割就像花瓣，被用来代替传统的圆形空白。这样就可以减少毛坯法兰部分的拉拔阻力。借助这种效果，在一次拉伸操作中很容易生产出非常深的圆柱形、方形和锥形杯。然而，在生产的杯子的侧壁存在接缝，如何连接接缝是一个问题。接缝采用镶金、折叠或卷边等机械缝法，同时对杯侧壁的接缝进行拉深和连接。重点研究了压边器形状和冲裁毛坯形状对连接件变形行为的影响，明确了合适的加工条件。同时也证实了将钣金成形工艺与连接工艺相结合，可以作为一种便于小批量生产极深杯的方法。

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.