Influence of Processing Parameters on the Thread and Spline Synchronous Rolling Process: An Experimental Study

The thread and spline synchronous rolling (TSSR) process is a new developed rolling process, which can form the different profiles simultaneously in the process and can ensure the consistency of the relative position of different profiles of parts. However, the multi-meshing motions are intercoupling and the multi-deformation characteristics are intercoupling during the forming process. It can easily result in dimension overshoot, and even does not make the synchronous rolling process go smoothly. Exploring the influence of controllable processing parameters on the synchronous rolling process, especially the geometric parameters of rolled parts, is helpful to determine the parameters and control the size error for a smooth rolling process. Thus, in this paper, the effects of controllable geometric parameters and motion parameters such as billet diameter, radial feed-in speed, and rotational speed of synchronous rolling die on the TSSR process have been studied. The synchronous rolling experimental scheme was determined using an orthogonal experimental design method, and the geometric parameters of different tooth profiles of rolled parts were measured and analyzed. The experimental results indicated that: the uncoordinated meshing movement between different tooth profiles is more likely to cause tooth error of the splined section of the part; variations of the processing parameters are more likely to cause fluctuations in the size of the splined section of the part, and change of the billet diameter mainly affects the outside diameter of the threaded and splined sections, and the threaded and splined pitches are mainly affected by the motion parameters of the synchronous rolling die; the motion parameters of the rolling die should be matched and the lower rotational speed needs to match the lower radial feed-in amount per revolution; the ideal dimensional accuracy can be obtained by using an appropriate processing parameter combination, for example, the pitch error of the splined section of the part is less than 0.5 μm under one set of experimental conditions in this paper.