No abstract

Large-width Cam has been widely used in high-power marine diesel engines, due to its well strength, wear-resisting, and service life. Unlike the traditional cam, the large-width Cam must be ground by swing grinding process to avoid grinding defects caused by high machining temperature. As the in uence of swing grinding parameters on machining surface quality has not been clearly clari ed, experimental study was discussed in the paper. The orthogonal experiment was designed and based on which the residual stress, surface roughness and hardness were analyzed. The results showed that, the grinding depth and the cam speed, have a relatively great in uence on the residual stress compared with grinding wheel swing frequency and swing amplitude. The grinding wheel frequency has the greatest in uence on the hardness of the cam surface and the increment of it will increase the hardness of the Cam.

Large-width Cam has been widely used in high-power marine diesel engines, due to its well strength, wear-resisting, and service life. Unlike the traditional cam, the large-width Cam must be ground by swing grinding process to avoid grinding defects caused by high machining temperature. As the influence of swing grinding parameters on machining surface quality has not been clearly clarified, experimental study was discussed in the paper. The orthogonal experiment was designed and based on which the residual stress, surface roughness and hardness were analyzed. The results showed that, the grinding depth and the cam speed, have a relatively great influence on the residual stress compared with grinding wheel swing frequency and swing amplitude. The grinding wheel frequency has the greatest influence on the hardness of the cam surface and the increment of it will increase the hardness of the Cam.

In conventional grinding (CG), camshafts with wide profiles suffer from poor quality and low efficiency because the large contact area between the grinding wheel and camshaft profile limits the diffusion of grinding temperature, leading to burn defects. Swing grinding (SG) can mitigate these problems as it involves a reciprocating motion along the axis of the grinding wheel; however, the lack of understanding of machined surface topography has restricted its application. Therefore, in this study, a surface topography prediction model was proposed based on the distribution, shape, and trajectory of grains. The model was verified through experiments, and the mean error was 10.2% for Rax and 3.8% for Ray; the roughness along the grinding direction was Rax, and the roughness along the vertical grinding direction was Ray. Compared to CG, SG has a 8% lower Rax. The influence of the wheel speed and feed rate in SG is consistent with that in CG. Rax exhibited a periodic trend with an increase in the swing amplitude and a monotonically decreasing trend with an increase in the swing frequency. The variation trend of Ray with the swing amplitude was the same as that of Rax. Furthermore, Ray exhibited a nonlinear increasing trend with an increase in swing frequency. Considering the processing and practical application of camshafts, the swing amplitude should be within 4 mm, the swing frequency should be within 3 Hz, the grinding wheel speed should be large, and the feed rate should be small.

In conventional grinding (CG), camshafts with wide profiles suffer from poor quality and low efficiency because the large contact area between the grinding wheel and camshaft profile limits the diffusion of grinding temperature, leading to burn defects. Swing grinding (SG) can mitigate these problems as it involves a reciprocating motion along the axis of the grinding wheel; however, the lack of understanding of machined surface topography has restricted its application. Therefore, in this study, a surface topography prediction model was proposed based on the distribution, shape, and trajectory of grains. The model was verified through experiments, and the mean error was 10.2% for Rax and 3.8% for Ray ; the roughness along the grinding direction was Rax , and the roughness along the vertical grinding direction was Ray . Compared to CG, SG has a 8% lower Rax . The influence of the wheel speed and feed rate in SG is consistent with that in CG. Rax exhibited a periodic trend with an increase in the swing amplitude and a monotonically decreasing trend with an increase in the swing frequency. The variation trend of Ray with the swing amplitude was the same as that of Rax . Furthermore, Ray exhibited a nonlinear increasing trend with an increase in swing frequency. Considering the processing and practical application of camshafts, the swing amplitude should be within 4 mm, the swing frequency should be within 3 Hz, the grinding wheel speed should be large, and the feed rate should be small.