大型正铲液压挖掘机工作装置动力学及能耗研究

发布时间：2018-01-09 09:30

本文关键词：大型正铲液压挖掘机工作装置动力学及能耗研究　出处：《太原科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来随着不断发展的国民经济和基础设施建设的需要,以及目前国家倡导的“一带一路”沿线建设,使得对液压挖掘机的需求量越来越大,极大地刺激了我国液压挖掘机生产制造业的发展。但我国液压挖掘机的发展受到西方各国技术壁垒的限制,在技术水平、生产工艺、产品产量和质量、使用可靠性等方面还存在诸多问题。尤其是我国的大型正铲液压挖掘机虽然已取得长足发展,但若要与西方强国争夺市场,还需要付出更加艰辛的努力。大型矿用正铲液压挖掘机工作装置的质量一般都比较大,在动臂下降过程中将会产生相当大的惯性力,如果能在该过程中进行能量回收的话,对挖掘机的节能将起到十分重要的作用。同时,由于工作装置质量较大,水平推压作业过程中铲斗运动速度的不均匀变化和物料阻力的不确定性变化会对主机及液压系统产生较大的冲击振动,造成工作装置的疲劳破坏。因此,对于大型正铲液压挖掘机而言,有必要回收工作装置下降过程中所产生的能量,以达到节能的目的;再者探究工作液压缸的流量特性与铲斗齿尖运行速度的关系,力求降低因铲斗运行速度不均而对整机产生的冲击振动,提高挖掘机的可靠性。本论文以某在动臂与斗杆间加装辅助液压缸的大型正铲液压挖掘机工作装置为研究对象,借助MATLAB平面连杆机构运动分析法对工作装置进行运动学逆解计算,求出了水平推压工况下铲斗匀速运动时各工作液压缸的速度及流量特性,并以液压缸的速度为控制信号在Adams软件中对三维模型进行运动学及动力学仿真分析,验证水平推压效果;确定了水平推压厚度及推压阻力,在Adams中通过对铲斗齿尖添加阻力进行仿真,确定了工作液压缸的受力及能耗,计算出了工作装置下降过程中所产生的重力势能以及负载所消耗的能量。结果显示铲斗齿尖的运行速度较为平稳,可降低水平推压工况下因铲斗运行速度不均而对工作装置造成的振动破坏;对比分析了工作液压缸输出的能量与负载力所消耗的能量之间的关系,该结果表明加装辅助液压缸后既回收利用了工作装置的重力势能,同时工作效率也比较理想。本研究结果可为大型正铲液压挖掘机实现匀速水平推压及回收利用工作装置重力势能提供理论参考。
[Abstract]:In recent years, with the continuous development of the national economy and infrastructure construction needs, as well as the current national advocacy of "Belt and Road" along the construction, making the hydraulic excavator demand more and more. The development of hydraulic excavators in China has been greatly stimulated by the development of the manufacturing industry of hydraulic excavators. However, the development of hydraulic excavators in China is limited by the technical barriers in western countries, in terms of technical level, production technology, product output and quality. There are still many problems in using reliability, especially the large hydraulic excavators in our country have made great progress, but they want to compete for the market with the western countries. The quality of the working device of the large mine forward shovel hydraulic excavator is generally relatively large, which will produce a considerable inertia force in the process of moving arm descent. If the energy recovery can be carried out in this process, it will play a very important role in the energy saving of excavator. The uneven change of bucket motion speed and the uncertainty change of material resistance during horizontal pushing and pressing operation will produce larger shock vibration to the main engine and hydraulic system, and cause fatigue damage of the working device. For the large hydraulic excavator, it is necessary to recover the energy generated in the process of working device descent, in order to achieve the purpose of energy saving. Furthermore, the relationship between the flow characteristics of the working hydraulic cylinder and the running speed of the bucket tooth tip is explored, in order to reduce the impact vibration caused by the uneven running speed of the bucket. To improve the reliability of the excavator. This paper takes the working device of a large forward shovel hydraulic excavator with auxiliary hydraulic cylinder between the arm and the bucket rod as the research object. The inverse kinematics analysis method of MATLAB planar linkage mechanism is used to calculate the kinematics inverse solution of the working device, and the velocity and flow characteristics of each working hydraulic cylinder under the condition of horizontal pushing and pressing are obtained. Taking the speed of hydraulic cylinder as the control signal, the kinematics and dynamics simulation analysis of the 3D model is carried out in Adams software to verify the horizontal push effect. The horizontal pressure thickness and push pressure resistance are determined. The force and energy consumption of the working hydraulic cylinder are determined by the simulation of adding resistance to the bucket tooth tip in Adams. The potential energy of gravity and the energy consumed by the load are calculated. The results show that the speed of the tip of the bucket tooth is relatively stable. It can reduce the vibration damage caused by the uneven running speed of the bucket under the horizontal pushing and pressing condition. The relationship between the output energy of the working cylinder and the energy consumed by the load force is compared and analyzed. The results show that the gravity potential energy of the working device is recovered after the auxiliary hydraulic cylinder is installed. At the same time, the working efficiency is also ideal. The results of this study can provide a theoretical reference for the realization of uniform horizontal push pressure and recovery of gravity potential energy of large forward shovel hydraulic excavators.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU621

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