生产的发展和实际的需要,对制造工业提出了越来越高的要求,如今,由于使用的需要,出现了一些非圆截面零件。所谓非圆截面零件,是指零件的横截面不是圆形,而是非圆形状,如梅花形、三角形、椭圆形以及其它的不规则形状等。典型的非圆截面零件有内燃机活塞、椭圆轴、异型轴等等。由于工艺的需 The development of production and the actual needs of the manufacturing industry put forward higher and higher requirements, and now, due to the needs of use, there have been some non-circular cross-section parts. The so-called non-circular cross-section of the part, refers to the cross-section of the part is not circular, but non-circular shape, such as plum-shaped, triangular, oval and other irregular shapes. Typical non-circular cross-section of the internal combustion engine piston, oval shaft, Shaped shaft and so on. Due to the process needs