介绍了一种新型的锥形方管无模拉伸成形方法,该方法解决了锥形方管难于塑性成形的问题。通过对锥形方管无模拉伸变形机制的研究,建立了锥形方管无模拉伸的速度模型,制定了无模拉伸加工工艺,给出了主要工艺参数的确定方法。实验研究证明,所建立的速度模型较好地表达了无模拉伸速度变化规律,采用无模拉伸加工方法所获得的加工件,理论尺寸与实际尺寸相对误差小于7.6%。 A new type of tapered square tube without die tensile forming method is introduced, which solves the problem of difficult plastic forming of the tapered square tube. Through the research on the mechanism of the tapered square tube without die tensile deformation, the velocity model of the tapered square tube without die is set up, the dieless drawing process is established, and the method of determining the main process parameters is given. Experimental results show that the established velocity model expresses the rule of no-mold tensile velocity and the relative error between the theoretical size and the actual size is less than 7.6%.