剪叉式升降平台液压缸推力与铰点力的计算
|
摘要
针对剪叉式升降平台的强度与刚度的校核问题,对升降平台中的剪叉机构进行了受力分析。运用虚位移原理计算液压缸推力,采用先整体后分离的方法计算了铰点力。虚位移原理分为几何法与坐标法两种方法,以五叉两缸式升降平台为例,采用两种方法对液压缸推力进行了推导,得到了两组液压缸推力表达式;运用先整体后分离的方法对剪叉机构进行了受力分析,建立了平衡方程。将某型号升降平台的尺寸参数代入到两组液压缸推力表达式中,用Matlab绘出了液压缸推力随升角变化曲线,并将两种方法得到的曲线与实际工程中测得的数据曲线进行了对比;将最大推力值与尺寸参数代入到铰点力计算的平衡方程中可得到铰点力值。研究结果表明,两种方法计算的结果最大偏差为2%;理论计算得到的液压缸推力值与实际工况中测得的推力值的误差在5%以内,验证了上述方法的准确性。上述方法均可推广到其他结构形式的剪叉式升降平台的液压缸推力与铰点力计算中。
Aiming at the problem that strength and stiffness of scissors lifting platform is checked,the principle of virtual work was used to obtain the driving force,and the whole model and discrete model were build to obtain the joint-force. Two ways based on principle of virtual work could be used for obtaining the driving force,they were called geometry and coordinate. The lifting platform with five scissors and two hydraulic cylinder was taken for example,whose expression of driving force was obtained with the two methods. Equilibrium equation was built to obtained the joint-force. The parameters were evaluated into the formula of driving force,driving force Fcurve along with change of lifting angleαwas drawed with Matlab,the two curves were compared with the curve obtained by testing in pratical engineering; The jointforce could be obtained by evaluating maximum of driving force and parameters into equilibrium equation. The results indicate that the error between of the two results is 2%; the error is within 5% between the theoretical value and the trial value,which verifies the correctness of method. The methods mentioned above can be applied to different scissors shifting platforms to obtain hydraulic cylinder driving and joint-force.
Aiming at the problem that strength and stiffness of scissors lifting platform is checked,the principle of virtual work was used to obtain the driving force,and the whole model and discrete model were build to obtain the joint-force. Two ways based on principle of virtual work could be used for obtaining the driving force,they were called geometry and coordinate. The lifting platform with five scissors and two hydraulic cylinder was taken for example,whose expression of driving force was obtained with the two methods. Equilibrium equation was built to obtained the joint-force. The parameters were evaluated into the formula of driving force,driving force Fcurve along with change of lifting angleαwas drawed with Matlab,the two curves were compared with the curve obtained by testing in pratical engineering; The jointforce could be obtained by evaluating maximum of driving force and parameters into equilibrium equation. The results indicate that the error between of the two results is 2%; the error is within 5% between the theoretical value and the trial value,which verifies the correctness of method. The methods mentioned above can be applied to different scissors shifting platforms to obtain hydraulic cylinder driving and joint-force.
引文
[1]TIAN Hong-yu,ZHANG Zi-yi.Design and simulation based on Pro/E for a hydraulic lift platform in scissors type[J].Procedia Engineering,2011(16):772-781.
[2]吴伟峰,张伟中,钱荣.一种新型二自由度并联机构的运动学及静力学分析[J].机电工程,2015,32(2):207-210.
[3]曾午平,卫良保.剪叉式液压升降台的设计计算[J].起重运输机械,2010(1):772-781.
[4]段慧文.剪叉机构计算与虚位移原理[J].演艺科技,2012(5):33-37.
[5]赵学龙,刘巧珍,马志刚,等.高空作业平台剪叉机构的受力计算[J].建筑机械化,2014,35(8):36-38.
[6]赵明君,刘剑雄,常安民.剪叉式升降机受力分析及有限元仿真[J].新工艺新技术,2013(3):18-20.
[7]陈立群,薛纭.理论力学[M].2版.北京:清华大学出版社,2014.
[8]张伟龙.剪叉式升降平台性能分析与优化设计[D].沈阳:东北大学机械工程与自动化学院,2015.
[9]周莎莎.剪叉式升降平台性能分析与结构优化[D].山东:山东轻工业学院机械与汽车工程学院,2012.
[10]赵艳平,马利平.基于Fluid SIM的剪叉式升降台液压系统设计[J].液压气动与密封,2014(12):17-19.
[11]史荣生,梁全.剪叉式升降平台机液压系统AMESim计算机仿真[J].机械,2016(8):33-35,54.
[12]胥军.剪叉式升降机举升机构分析与优化[J].机械科学与技术,2013,32(6):920-927.
[2]吴伟峰,张伟中,钱荣.一种新型二自由度并联机构的运动学及静力学分析[J].机电工程,2015,32(2):207-210.
[3]曾午平,卫良保.剪叉式液压升降台的设计计算[J].起重运输机械,2010(1):772-781.
[4]段慧文.剪叉机构计算与虚位移原理[J].演艺科技,2012(5):33-37.
[5]赵学龙,刘巧珍,马志刚,等.高空作业平台剪叉机构的受力计算[J].建筑机械化,2014,35(8):36-38.
[6]赵明君,刘剑雄,常安民.剪叉式升降机受力分析及有限元仿真[J].新工艺新技术,2013(3):18-20.
[7]陈立群,薛纭.理论力学[M].2版.北京:清华大学出版社,2014.
[8]张伟龙.剪叉式升降平台性能分析与优化设计[D].沈阳:东北大学机械工程与自动化学院,2015.
[9]周莎莎.剪叉式升降平台性能分析与结构优化[D].山东:山东轻工业学院机械与汽车工程学院,2012.
[10]赵艳平,马利平.基于Fluid SIM的剪叉式升降台液压系统设计[J].液压气动与密封,2014(12):17-19.
[11]史荣生,梁全.剪叉式升降平台机液压系统AMESim计算机仿真[J].机械,2016(8):33-35,54.
[12]胥军.剪叉式升降机举升机构分析与优化[J].机械科学与技术,2013,32(6):920-927.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |