【作者】 赵鑫；

【导师】 金淼；

【作者基本信息】 燕山大学 ， 材料加工工程， 2012， 硕士

【摘要】 柱塞式液压缸是大型液压机本体结构中应用最多的执行元件。其中，双球铰结构是工作缸柱塞与活动横梁的主要连接形式。当液压机受偏心载荷作用时，柱塞偏转与导套及密封处接触产生侧向推力，侧推力的作用加速了导套及密封的磨损。因此，侧推力成为评价双球铰结构优劣的关键性问题。双球铰结构主要由上下球铰和中间杆三部分构成，在传统液压机设计理论中，认为增长中间杆长度并减小球铰的球面半径能够更好的减小侧推力。然而，在当今液压机的设计制造中，尤其是在大型液压机柱塞缸设计中，对双球铰结构的设计与传统理论不尽相同，尤其是该结构主要尺寸的确定依据尚不明晰。本文从侧推力产生的机理展开研究，对偏心载荷下，双球铰式柱塞结构进行了受力分析，讨论在不同接触条件下，柱塞侧壁处侧推力的产生机理及作用方式。并以大型非线性有限元软件MSC.Marc为平台，建立了该结构的三维有限元仿真模型，系统的研究了中间杆长度及直径、上下球铰半径和导套间隙等对侧推力产生的影响规律。研究表明:相同双球铰结构下，柱塞与导套在不同位置发生接触后，侧推力的作用方式及效果各不相同。相同接触条件下，不同结构柱塞与导套发生接触后，随着中间杆长度的增长，侧推力呈减小趋势；随着中间杆直径的增大，侧推力呈减小趋势；随着球铰球面半径的增大，侧推力呈增大趋势；随着导套间隙的增大，侧推力呈减小趋势；以某厂125 MN锻造液压机为原型，按照1:10的尺寸比例设计制备了双球铰柱塞式液压缸侧推力实验装置，配备了五组不同规格尺寸的中间杆和球铰，进行了在偏心载荷下，不同双球铰结构柱塞所受侧推力大小的实验。实验结果表明：中间杆长度、上下球铰半径和导套接触位置对侧推力的影响规律与计算结果基本吻合。通过对大型柱塞缸双球铰结构的研究后得出：在工程设计中，中间杆长度系数取0.64~0.83；中间杆直径系数取：0.59~0.63；球铰球面半径系数取：1~1.15；更多还原

【Abstract】 As an actuator, the plunger type cylinder has been widespread used on the structureof large-scale hydraulic press. The double spherical structure is the major joint formbetween the plunger and the moving beam. When the hydraulic press received theoff-center load, the plunger deflected, contacted with the guide and seals, then producedthe side thrust which may speed up the wear and tear. So that, the effect of side thrustbecame a core evaluation criteria when the double spherical structure was discussed.Including the two spherical hinges and a connecting rod between them, there are threemain parts in the double spherical structure. In the traditional hydraulic design theory, it isthe most important ways to reduce the side thrust by increasing the length of connectingrod and decreasing the radius of spherical hinges. However, the reality is not that.Contrasted with the previous theory, there are some differences in the designs hydraulicpress nowadays, especially on the large-scale plunger cylinder, even have not a clearevaluation for the major sizes on the structure of double spherical joint .First, the research on the mechanism of side thrust as a beginning, on the off-centerload condition, do the force analysis about the structure above, then discussed the differenteffects on the side thrust of plunger when changing the contact conditions. Based on largenon-linear finite element software MSC.Marc as the platform, the three-dimensional finiteelement simulation model was established. Through a lot of numerical simulations, theinfluencing rule of spherical hinge radius, the rod length and guide clearance on the sidethrust were summarized systematically. The research shows that: With the same sphericalstructure, the different contact positions may lead the different ways and effects on theside thrust. Under the same contact condition, the thrust decreases with the increase of therod length and the rod diameter. The thrust increases with the increase of the sphericalhinge radius. The thrust decreases with the increase of the guide clearance.In this paper, a experimental plunger cylinder and a test device was produced as theprototype of 125 MN forging hydraulic press according to the proportion of 1:10, whichequipped with five groups of different sizes of rods and hinges. Experiments on the test ofthe side thrust were done in the work conditions of off -center loads. Through the data getting from transducers, The comparison between the result of experiments and thetheoretical analysis can be done as a proving. The experimental result shows that the rulesgot by theoretical analysis are basically true.Through the whole research on the double spherical structure: In the engineeringdesign, the rod length factor: 0.64~0.83. the rod diameter factor: 0.59~0.63. the sphericalhinge radius factor: 1~1.15.更多还原