Forming method for small-radius bent pipes

Abstract

The invention provides a forming method for small-radius bent pipes. A one-mold multi-piece mode is adopted. The forming method comprises the steps that the one-mold multi-piece number is analyzed and determined through a computer aided engineering tool; raw material pipes are provided and placed in a forming mold, pre-forming is conducted on the pipes, the round cross section of each pipe is made to become an oval cross section with flat upper and lower portions and wide left and right portions, and oval pipes are formed; the oval pipes are bent in a perfusion bending mode to be in a shape similar to the shape of a product; and the bent pipes are formed to be in a required shape by applying internal high pressure. According to the forming method for the small-radius bent pipes, the small-radius bent pipes with the pipe diameter being smaller than 1 D can be formed stably and reliably, and in addition, the defects that the inner side of each bent pipe is crumpled, sunken and the like due to the fact that the radius of each small-radius bent pipe is too small can be effectively overcome.

Description

technical field [0001] The invention relates to the technical fields of pouring bending, CAE (computer-aided engineering) analysis technology, and internal high-pressure forming. Specifically, the invention relates to a forming method of a small-radius elbow. Background technique [0002] figure 1 It is a three-dimensional schematic diagram of the mold part of a common elbow forming equipment in the prior art. Such as figure 1 As shown, the mold part includes many parts such as clamping die 101, guide die 102, wheel die 103, anti-wrinkle plate 104 and core ball 105, and it presses the elbow (not shown) by clamp die 101, guide die 102, etc. Into the profiling cavity of the wheel mold 103, then the elbow is bent by the rotation of the wheel mold 103. The process of this method is simple and practical, but it also has certain limitations. The main reason is that when the bending radius of the product is less than 1D pipe diameter, for example, when the bending radius is only...

AI Technical Summary

Problems solved by technology

Although this method can effectively solve the difficulties in the above-mentioned conventional methods and the disadvantage that the bending pipe needs a section of straight arm to clamp, and can bend several products at the same time, which improves the material utilization rate, but when performing perfusion bending, if the bending pipe If the inner radius is too small, defects such as wrinkles and dents will still inevitably appear

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