| In the current industrial development process of the country,CNC mechanical processing equipment has replaced the traditional mechanical processing equipment because of its unique technical properties.In order to make the performance of CNC processing equipment more excellent,to achieve high speed,high precision,high stability of the world-class level,this paper studies the stability of CNC machine tool feed system.For the numerical control machine feed system with linear motor and liquid static pressure guide as the main component,the simulation experiment of external load change is carried out to explore its stability.The main research contents and results are as follows:(1)To analyze the factors affecting the stability of the numerical control machine feed system,set the feed system by the linear motor as the research object.Finally,it is true that the linear motor and the liquid static pressure guide are the main research objects.(2)To study the application of different load mass m on the linear motor,the thrust F and the speed v of the linear motor.Finally,a short-term oscillation occurs at the linear motor speed when different load mass is applied,and as the load mass m is larger,the greater the oscillation amplitude of speed v can be restored to the initial speed 1m/s within 0.16 s,and the amplitude calculation of the oscillating amplitude of the velocity is calculated,and the results show that the oscillating overshoot ? of the velocity is within the permissible range.The thrust F of the linear motor will also change over time with the increase of the load mass m,it can be calculated that when the load mass m is 240 kg,the license range of overshoot alpha is exceeded,and the maximum mass m value of the load is calculated according to the range requirements of overshoot not more than 185 kg,and the maximum thrust F of the linear motor is 1025 N.(3)To study the change of the thickness of the oil film h and the stiffness of the oil film when applying different load mass m on the liquid static pressure guide.The oil film thickness h under different m is obtained by the oil film thickness formula,and then the oil film stiffness S is obtained,and the oil cavity pressure in the static pressure guide rail of different mass m is simulated by simulation software.The results show that when the load mass m is 120 kg,the inner pressure P of the oil cavity is 4.51 e + 06 MPa,and when the load mass m is 160 kg,the maximum ? value of the oil film thickness overshoot is 14.3%,the maximum is 6.3% and the maximum value is not more than 30%.It is shown that the liquid static pressure-guided rail oil film can carry the load quality set by the experiment.(4)The factors and parameters affecting the stability of the machine tool are determined,the mechanical structure and temperature field of the machine feed system are coupled to analyze the results,and the stability of the machine feed system driven by a linear motor under variable load conditions can meet certain working requirements,and finally some views are put forward for the design of machine tool stability. |
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