Dynamic Characteristic Analysis Of Diesel Engine Nozzle Concave Face Grinder

Concave face grinding is the key to the diesel engine nozzle precision manufacturing technology,the dynamic characteristics of the concave face grinding machine directly determine the quality and work performance of the fuel injector.Take WX₆013 diesel engine nozzle high-precision CNC concave face grinding machine as the research object.Complete the structure dynamic characteristics analysis and lightweight design of grinding machine based on the finite element method（FEM）.The specific research work can be listed as follows:1)The high-precision three-dimensional digital model and the finite element dynamic model of concave face grinding machine are set up.The finite element dynamic model of grinding machine is established combined with joint stiffness by the spring damping element method.2)A dynamic model of three-row roller slewing bearing is established based on Hertz contact theory and discrete numerical method.The theoretical calculation method of three-row roller slewing bearing dynamic parameters is deduced.The joint parameters are get through the three-row roller bearing stiffness coefficient measurement test.3)The dynamic characteristics analysis of grinding machine is done based on the modal analysis theory.The influence of the integration of joint rigidity,constraint method,structure and material of rotary table and column wall thickness on grinder dynamic characteristics is systematically studied and revealed.The lightweight design of the high-precision concave face grinder is done based on a systematic structure parameter sensitivity analysis of machines’ dynamic performance.The results are shown:1)It is found that the structure design of rotary table and column dismatches the selection of turntable bearing,based on the analysis of inherent frequency characteristics of WX₆013 diesel engine nozzle CNC concave face grinder.The rigidity and quality of rotary table and pillar are too big,compared with the turntable bearing stiffness.2)For WX₆013 concave face grinder,the rotary table structure modification,the decrease of pillar thickness and larger hole depth can lightweight the machine tool.Finally,the quality of grinding machine decreases about 2120kg with a 39.92%decline.The first three order natural frequency of grinding machine is respectively increased by 55.68%,42.83%and 55.68%.