在仪表附件中,有许多铰链、夹子一类的零件,端部常常需要弯曲成铰链圆环。由于铰链圆环的形状和尺寸精度都有一定的要求,一般都是通过好几道工序来完成的;当圆环孔要求配合时,弯曲前在孔内要插入芯棒,弯曲后再拔出芯棒,这样不仅劳动强度大,工效低,而且模具很容易损坏。如图1所示的两种弯曲件,两个端头都要求制成铰链圆环,由于制件本身还要进行弯曲 In instrument accessories, there are many parts such as hinges and clips, and the ends often need to be bent into hinged rings. Due to the shape and dimensional accuracy of the hinge ring has certain requirements, usually through several processes to complete; when the ring hole with the requirements before bending in the hole to insert the mandrel, bending and then pull out the core Rod, so not only labor-intensive, low efficiency, and the mold is very easy to damage. As shown in Figure 1, two kinds of curved parts, both ends are required to make a hinged ring, due to the workpiece itself to be bent