Research On The Model Of Grinding Process And The Technology Of Point Grinding

Grinding is an important machining process with removing the materials using random distributed grains on the grinding wheel. It is a widest and efficient approach to achieve precision and ultra-precision machingingin manufacturing business, which accounts for30%-40%in the mechanical process. Point grinding is a rising technology to machining cylindrical parts. Due to the changed contact area resulting by swivel angle, grinding meachanism has been modified.Computer simulation is an assistant method to predict the parameters of grinding process, especially in the limited conditions. By the research objects on surface grinding and point grinding, the following details are numerical and experimeatally discussed:workpiece surface topology, grinding wheel characteristics, fatigue life of ground parts and the ground ceramics. The specific introductions are:(1) Workpiece surface topology is generated by modeling the grain trajectory to discuss the effects of the swivel angle a on the ground surface topology. Based on the cutting speed and swivel angle, the numerical results are experimentally validated to show the relationship of swivel angle with surface roughness. Several estimated factors are compared to provide the refernce for surface topology in point grinding.(2) Grinding temperature has an indirected effect on workpiece surface quality. The temperature field and maximum can be simulated using the finite element method, and the sensitive grinding parameter can be explored by the moving heat source. The heat distribution caused by interferce between the wheel and the workpiece can display the relationship of temperature with swivel angle, and the grinding temperature was also measured by thermal imager.(3) The there-dimensional wheel model was developed by randomizing the arrangement of the spherical grains, and these grains are replaced by the hexahedrons to generate a new wheel surface. A dressing model of single point diamond was used to condition the grinding wheel. The dressed wheel characteristics were numerically and eperimentlly stated with the help of measured results by the laser sensor. Wheel wear was simulated by the finite element method as well.(4) Three-dimensional workpiece surface topology was generated by selecting the effective grain trajectories with the virtual wheel. The relationship between the single point dresser and workpiece topology was expeiemntally-measured and numerical-simulated. The effect of grain distribution on contact arc and uncut chip thickness was also numerically discussed.(5) Based on point grinding and experiments of fatigue life, workpiece samples of45steel and Q235were ground first, and then they were tested to get their liminted cycle life. It was found that surface quality of45steel is more sensitive than that of Q235, and resonable machining parameters can improve the fatigue life of45steel parts.(6) The machinability of Zirconia and Silicon Nitride is investigated in point grinding to conclude the ’ductile’ and ’brittle’ grinding mode. The difference between the thoeritical and real grinding depth was measured. At last, the conclusions and suggestions were given using the experimental and numerical results.