Abstract: A grinding technology about discrete type (circular, elliptical, saddle-shaped, etc) spatial welding seam is proposed—the cubic boron nitride(CBN) belt grinding method with traveling equivalence. On one hand, the method is based on the measurement technology and the prediction model of grinding depth, with the four-axes coordinated movement and constant pressure floating-type belt grinding, it can ensure the equal-margin control; on the other hand, aiming at the difficult machining of the welding seam’s material, using of CBN belt can realize the high efficiency and accuracy. The processing principle of the belt grinding method with traveling equivalence and positive-stop is illustrated, the processing model of traveling grinding is built and the influence of grinding depth and swing angle is analyzed. Based on the measurement technology and the prediction model of grinding depth, governing equation of equivalent grinding is obtained. In the end, the grinding test aiming at the typical part of elliptical welding seam—the combustor casing—can make sure the error of grinding margin’s depth in ±0.005 mm, which proves the method’s feasibility, and obtains the optimum processing parameters on grinding the welding seam(grinding belt liner speed: 24 m/s, grinding force: 170 N, workpiece rotating speed: 1 r/min). Furthermore, the most influential processing parameter on material removal rate is the workpiece rotating speed.

Key words: cubic boron nitride belt, discrete spatial welding, equal-margin control, equivalent follow grinding