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钣金加工零件有哪些成型方法?

钣金加工除了采用机械制造也中普遍采用的冷冲压工艺之外，还有一些其他的特别的方式，橡皮液压成形、拉弯成形、喷丸成形：

1、橡皮液压成形：向装于容框中的橡皮胎内充高压液体，使之膨胀，从而推动毛料按照模胎的形状形成零件。这样形成的零件准确度高，表面无压痕。橡皮胎是一种通用的柔性凹模，所以在工作台上可以安放多个不同形状的模胎。这种方法成本更低，生产效率高，一次循环之后就能够同时产出多个零件。

2、拉弯成形：先将型材毛料沿长度方向拉伸至屈服极限，然后保持拉力并使毛料按拉弯模的型面弯曲成形。预先的拉伸可以有效地改变弯曲时毛料内部的应力分布，从而提高零件的成形准确度。

3、喷丸成形：利用压缩空气(或高速叶轮)使直径为0.3～2.5毫米的许多钢丸从喷嘴喷出。高速弹流打击毛料的一侧表面，使表面层金属因受挤而面积加大，产生压应力，使毛料向未受弹丸打击的一面弯曲，成为曲面形状。

以上三种成形方法为企业很大程度上节约了成本，不仅有利于增强零件的疲劳强度，对实现高效率的生产也具有重要意义，极大推动了生产力的提升。

In addition to the cold stamping process, which is commonly used in mechanical manufacturing, there are some other special ways, such as rubber hydroforming, bending forming and shot peening.

1, rubber hydroforming: filling high pressure liquid in the rubber tyre installed in the frame so that it expands, thus pushing the wool to form parts according to the shape of the mold. The parts formed in this way are of high accuracy and no indentation on the surface. Rubber tyre is a versatile flexible die, so multiple moulds with different shapes can be placed on the worktable. This method is lower in cost and more efficient in production. After one cycle, multiple parts can be produced simultaneously.

2, stretch bending forming: first stretch the profile wool along the length direction to the yield limit, then maintain the tensile force and make the wool bending and forming according to the stretch bending die surface. Pre stretching can effectively change the stress distribution inside the wool when bending, thereby improving the forming accuracy of the parts.

3. Shot Peening: using compressed air (or high speed impeller), many steel balls with diameters of 0.3 to 2.5 mm are ejected from the nozzle. The high velocity elastoflow strikes one side of the surface of the wool material, which causes the surface metal to be squeezed and increase the area, producing pressure stress, so that the material will bend to the side of the shot not hit by the projectile and become a curved surface.

The above three kinds of forming methods have saved the cost to a large extent, which not only helps to enhance the fatigue strength of the parts, but also is of great significance to the realization of high efficiency production, which greatly promotes the promotion of productivity.

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