Extrusion Process with Control of Bend and Twist for Producing Shaped Tubes and Bars without Additional Processes for Cancel of Distortion and Second Forming

将作者开发的动模柔性挤压工艺应用于汽车车架和发电机涡轮叶片的成形。研究结果如下：建立了挤压过程中模具连续恒速旋转的柔性挤压系统。利用该系统进行了模具倾角两级变化的挤压试验。在合适的冲头速度和模具转速下挤压毛坯，得到了没有弯曲缺陷的曲面产品。证实了该挤压系统可以有效地用于制造细长复杂曲面产品。新工艺是通过由两个固定角度倾斜的交叉模具组成的孔口挤压钢坯，建议供应具有不对称截面的扭曲产品，如涡轮叶片。利用该工艺进行了矩形和梯形截面的挤压试验。结果表明，随着模孔标准倾角的增大，挤压件的弯曲度减小。针对挤压过程中截面、曲率和扭转角度的变化，设计了一种具有较高柔性的新型挤压系统，利用该系统对对称和非对称H型钢进行了挤压试验，并对系统的性能进行了详细的检验，应用该系统可以在不更换模具的情况下快速生产出各种尺寸的H型曲杆。

The flexible extrusion process with moving dies, which has been developed by the author, is applied to forming of space frames for automobiles and turbine blades for generators. The results are summarized as follows :The flexible extrusion system, in which the die could be continuously rotated at a fixed speed during extrusion, is constructed.The extrusion tests with two-step change in the inclination angle of the die are carried out using the system.The curved products without defects in shape curved are obtained as the billets are extruded at the appropriate punch speed and rotating speed of the dies.It is confirmed that the extrusion system is effectively utilized for manufacturing elongated and complicatedly curved products.The new process, in which the billets are extruded through an aperture composed of two crossed dies inclined at a fixed angle, is proposed to supply twisted products with asymmetric cross sections such as turbine blades. The extrusion tests for rectangular and trapezoidal cross sections are carried out by use of the process. It is clarified that the bend of the extruded product decreases with increasing the standard inclination angle of the die aperture. The validity of the process is confirmed.For varying the cross section, the curvature and the angle of twist during extrusion, the new system with high flexibility is designed.The extrusion tests for symmetric and asymmetric H-type bars are executed using the system.The performance of the system is examined in detail.The H-type curved bars with various dimensions can be promptly produced without changing the dies by applying the system.