图1为我厂生产的BJ212车身中的门锁固定板,在加工螺纹底孔时,过去采用先制翻边的预制孔(用钻孔),然后再翻边(模具见图2)。这样,操作困难,工效较低,钻孔时钻头损耗严重。同时,难以保证六孔间的孔距,翻边后口部变薄,且不平齐。翻边高度虽已达到3.5mm,但因翻边后跟部R的影响,攻丝后有效螺纹还不足3扣,装配时会产生滑丝现象。 Figure 1 shows the BJ212 car door lock plate in our factory. In the process of machining the screw bottom hole, a prefabricated hole with a flanged flange (using a drill hole) was used in the past, and then the flanged flange (see Fig. 2). In this way, the operation is difficult, the work efficiency is low, the drill bit loss when drilling is serious. At the same time, it is difficult to ensure the hole spacing between the six holes, flanging the mouth after the thinning, and not flush. Although the flange height has reached 3.5mm, but due to the impact of flanging heel R, tapping the effective thread less than 3 buckle, the assembly will have slip wire phenomenon.