Design and dynamic optimization of an ultra-precision micro grinding machine tool for flexible joint blade machining

Ultra-precision micro machine tool (UPMMT) has always been a high-precision machine tool for microscale/mesoscale mechanical components. It has demonstrated many advantages in small footprint, low cost of energy, low operational cost, high machining precision, etc. However, developing UPMMT is always a complicated, labor-consuming work and lacks scientific approach and guidelines. This paper is devoted to introduce a detailed design method of a micro grinding machine tool used for flexible joint blade machining. The micro grinding machine tool was built up with a combined support structure of both advantages of gantry column and single column structure, allowing more work zone and better static stability. In order to improve the dynamic performance of the machine tool, an optimization design method based on sensitivity analysis was proposed. The weakest link of the machine tool structure was identified and selected as the optimization target, and an optimization equation was established with the nature frequency as the optimization goal, mass and size as the constraint condition. The results showed that the first six nature frequencies of the machine tool were increased with different degrees and the first nature frequency was increased by about 10%. The biggest resonance peak of the machine tool was reduced in the x direction by 8.6%, in the y direction by 6.4%, and in the z direction by 10.1%. Based on the optimization results, a prototype was built, and machining tests were carried out on flexible joint blade machining to evaluate the machining performance of this machine tool.