Structure Design And Optimization Of Grinding Carriage For High-speed And High-precision Grinder

As the key component of an automobile engine valve train, camshaft controls the entireintake and exhaust system. The sophisticated working environment and dynamic load requireshigh processing precision and surface roughness of a camshaft. The CNC camshaft grinderwith high speed and high precision is the core machine tools of camshaft, whose structure andcharacteristics will directly determine the quality of the camshafts it produces. While, as thekey component of the camshaft grinder, the grinding carriage’s dynamic characteristics andstructural form will directly affect the processing performance of the machine, both thequality and the accuracy of the parts. Therefore, it’s very important to apply static state anddynamic analysis of key components and optimize the structure for the overall performance ofthe camshaft grinder if one wants to develop the grinding carriage. This approach will havereferential value for independent research and development of camshaft grinder.So in my research, firstly, the mathematical model of camshaft grinding process wasestablished based on the features of camshaft grinding. The camshaft profile with rollerfollower and the trajectories of grinding wheel central point was derived to get the universalformula of displacement model of grinding wheel center. After that, the CAM mechanism andthe dynamic simulation was analyzed to get the follower motion program intuitively.Secondly, the grinding process of single abrasive was analyzed to establish grindingforce model. Based on that, the external cylindrical grinding simulation of a single abrasive isestablished in order to explore the grinding force changes with different grinding speed andgrinding depth.Thirdly, the overall scheme of grinding carriage was designed according to the specialrequirements of camshaft grinding. During the process, the key components of grindingcarriage were designed, such as ceramic bond CBN grinding wheel, electric spindle withhydrodynamic-hydrostatic bearing, linear motor and hydrostatic guideway, on-line grindingwheel dresser and on-line dynamic balancing device.Finally, the statics and dynamics analysis of the spindle and carriage was conducted tocheck the strength of the key components by ANSYS software. Then the natural frequency andvibration model of the spindle and carriage were analyzed to verify the feasibility of the design, which effectively avoids the resonance region. Furthermore, structure optimizationdesign of the grinding carriage was carried on to improve the rigidity, reduce the vibration andimprove the quality.