在自行车的零件中,原料并带有小孔的零件是比较多的。如衣架支撑,单支杆等。这些零件加工工艺是在棒料压扁后再加工小孔,故材料表面强度大大提高,对加工小孔增加困难。特别是单支杆原φ11棒料压扁厚度为6毫米,加工φ6.5孔,如采用普通结构冲孔模,凸模容易折断。所以在自行车行 In the bicycle parts, raw materials and parts with small holes is more. Such as hanger support, single pole and so on. These parts processing technology is processed in the bar after the flattening of small holes, so the material surface strength is greatly increased, the processing holes increase difficulty. In particular, the original single pole rod thickness of 11 bar crushed to 6 mm, φ6.5 hole processing, such as the use of ordinary structure punching die, punch easily broken. So in the bike line