楔横轧梯形螺纹轴成形机理

通过分析螺纹轴齿形成形过程,并结合金属流动特点,获得楔横轧梯形螺纹轴的成形机理.考虑到轧制过程轧件螺旋升角瞬时变化特点和成形段齿形截面变化等因素设计了楔横轧模具,采用有限元分析软件Deform-3D对楔横轧梯形螺纹轴齿形成形过程进行模拟,得到精度较高的梯形螺纹轴轧件.利用有限元点跟踪功能,对轧件多个点进行跟踪,详细分析了轧件螺纹不同位置各点的径向、轴向位移变化情况,从中获得螺纹段各处金属流动规律.采用软件模拟参数进行了相应的楔横轧实验,得到的梯形螺纹轴实验轧件与有限元模拟结果相同.模拟和实验结果表明,模具螺旋升角采用轧件瞬时半径对应螺旋升角时,能够轧制出形状精确的螺纹轴.

Forming mechanism of trapezoidal thread shafts in cross wedge rolling

The forming mechanism of trapezoidal thread shafts was proposed by analyzing the forming process of teeth shape and the characteristic of metal flow. A die of cross wedge rolling was designed in consideration of the instantaneous variation of helix angle and the variation of teeth cross-section. The rolling process of trapezoidal thread shafts in cross wedge rolling was simulated with the finite element software Deform- 3D, and trapezoidal thread shafts with high precision were obtained. Radial and axial displacement variations in different sections of the rolled pieces were analyzed in detail by tracking multiple points on the rolled pieces using the tracking function of the finite element method. The metal flow law at different positions on the rolled piece was found out. The trapezoidal teeth profile rolled in rolling experiments performed by using the simulating parameters is similar to that calculated by the simulation software. Simulation and experiment results show that trapezoidal thread shafts with precise shape can be rolled by using the corresponding helix angle of the die to the instantaneous rolling radius.