笔头加工机床端面凸轮驱动系统特性分析与极限转速确定
|
摘要
针对现有多工位圆珠笔头加工机床主驱动机构—圆柱端面凸轮-从动件-摇臂-动力头系统动力学及力封闭弹簧展开研究。首先研究了在理想运动状态下摇臂-动力头间非分离条件,对已知预压缩的力封闭弹簧进行刚度校核,得到了在现预压缩量下力封闭弹簧刚度最小值;然后考虑圆柱端面凸轮-滚子和摇臂-动力头两高副处接触变形属性,建立对应等效非线性弹簧阻尼连续接触模型,导出该系统等效集中质量的动力学方程并予以求解,得到了接近实际运动状态下力封闭弹簧刚度及预压缩量下摇臂-动力头间非分离条件并对现机床端面凸轮的工作转速进行校核;最后在不改变力封闭弹簧刚度情况下通过调增力封闭弹簧的最大可预压缩量,得出了该机床端面凸轮的极限工作转速。
In this paper,the dynamic performance and the force closed spring of thecylindrical end cam-followerrocker-spindle unitsystem foracurrent ball pen point machine is investigated. The first and foremost,the force closedspring with the current pre-compression is verified according to the non-separation condition between the rocker arm and the spindle unit by the ideal motion,and the minimum value of the spring is obtained. Then the equivalent nonlinear spring-damper model is established at the contact areas of higher pairs,the non-separation condition under pre-compression closed spring is presented considering the local deformation at the contact areasby the dynamic equation of the equivalent mass of the system. In addition,the ball pen point machine is given to analyze the cam mechanism system 's dynamic characteristic, and the obtained results show that the separation and jumping phenomenon occurs between the rocker arm and the spindle unit of the cam-follower system in the dynamic process. At last,the limiting speed of the cylindrical end cam of the machine is obtained without changing the locking spring stiffness and changing the pre-compression of the force closed spring.
In this paper,the dynamic performance and the force closed spring of thecylindrical end cam-followerrocker-spindle unitsystem foracurrent ball pen point machine is investigated. The first and foremost,the force closedspring with the current pre-compression is verified according to the non-separation condition between the rocker arm and the spindle unit by the ideal motion,and the minimum value of the spring is obtained. Then the equivalent nonlinear spring-damper model is established at the contact areas of higher pairs,the non-separation condition under pre-compression closed spring is presented considering the local deformation at the contact areasby the dynamic equation of the equivalent mass of the system. In addition,the ball pen point machine is given to analyze the cam mechanism system 's dynamic characteristic, and the obtained results show that the separation and jumping phenomenon occurs between the rocker arm and the spindle unit of the cam-follower system in the dynamic process. At last,the limiting speed of the cylindrical end cam of the machine is obtained without changing the locking spring stiffness and changing the pre-compression of the force closed spring.
引文
[1]石永刚,吴央芳.凸轮机构设计与应用创新[M].北京:机械工业出版社,2007.
[2]苏利亚,王占胜.凸轮机构锁合弹簧刚度分析[J].现代机械,2011(6):58-9.
[3]田永利,罗振军,邹慧君.基于RecurDyn的凸轮剪线机构仿真与分析[J].机械设计与研究,2012,28(3):13-6.
[4]张青,邹慧君,郭为忠.多圆弧凸轮接触点位置的计算机辅助求解[J].机械设计与研究,2005,21(1):17-9.
[5]张策.机械动力学[M].第二版.北京:高等教育出版社,2008.
[6]HUNT K H,CROSSLEY F R E.Coefficient of restitution interpreted as damping in vibroimpact[J].Journal of Applied Mechanics,1975,42(2):440-445.
[7]WERNERGOLDSMITH.Impact:the theory and physical behaviour of colliding solids[M].Edward Arnold,2001.
[8]余涛.多运动副间隙对机构动力学特性的影响[D].郑州:郑州大学.
[9]LANKARANI H M,NIKRAVESH P E.Continuous contact force models for impact analysis in multibody systems[J].Nonlinear Dynam,1994,5(2):193-207.
[2]苏利亚,王占胜.凸轮机构锁合弹簧刚度分析[J].现代机械,2011(6):58-9.
[3]田永利,罗振军,邹慧君.基于RecurDyn的凸轮剪线机构仿真与分析[J].机械设计与研究,2012,28(3):13-6.
[4]张青,邹慧君,郭为忠.多圆弧凸轮接触点位置的计算机辅助求解[J].机械设计与研究,2005,21(1):17-9.
[5]张策.机械动力学[M].第二版.北京:高等教育出版社,2008.
[6]HUNT K H,CROSSLEY F R E.Coefficient of restitution interpreted as damping in vibroimpact[J].Journal of Applied Mechanics,1975,42(2):440-445.
[7]WERNERGOLDSMITH.Impact:the theory and physical behaviour of colliding solids[M].Edward Arnold,2001.
[8]余涛.多运动副间隙对机构动力学特性的影响[D].郑州:郑州大学.
[9]LANKARANI H M,NIKRAVESH P E.Continuous contact force models for impact analysis in multibody systems[J].Nonlinear Dynam,1994,5(2):193-207.