装载机液力变速器换挡品质仿真与试验研究

发布时间：2018-01-12 02:24

本文关键词：装载机液力变速器换挡品质仿真与试验研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：装载机是世界上应用范围较广的工程机械之一,在公路、矿山、港口等建设工程中都发挥着重要作用。装载机作业环境恶劣、作业工况复杂,驾驶员需要通过频繁的换挡操作来完成铲装作业,对驾驶员的驾驶水平是一种严峻的考验。液力变速器的应用不仅增强了装载机的自适应性,而且极大的改善了驾驶员的驾驶操作。因此,液力变矩器在装载机上的应用已成为主流趋势。随着技术的发展,对装载机性能提出了更高的要求。目前,国内装载机普遍存在换挡品质问题,较差的换挡品质不仅会引起换挡冲击,还会增加传动系统的动载荷,加速零件的磨损,降低零件的使用寿命。因此,提高装载机液力变速器换挡品质具有重要的意义。以某型液力变速器为研究对象,对其换挡品质进行仿真并进行了试验验证,本文主要研究内容和结论如下。(1)确定了换挡品质的评价指标为冲击度、滑磨功和换挡时间,并对换挡品质影响因素进行了分析。对液力变速器结构、换挡传动路线和电液控制系统进行了分析,对平稳结合阀的工作原理进行了研究,并重点分析了液力变速器前进挡与后退挡换挡品质控制策略;建立液力变速器换挡过程等效力学模型,对换挡过程扭矩相与惯性相进行了研究,并分析了换挡各阶段离合器油压对于换挡品质的影响,为换挡品质研究奠定了基础。(2)根据液力变速器电液控制系统原理,利用液压系统仿真软件AMESim建立其电液控制系统模型,便于分析离合器换挡油压与换挡时间;基于液力变速器试验台模型,建立了液力变速器机械传动系统仿真模型,便于分析离合器主、从动片转速及滑磨转矩,计算换挡滑磨功;为保证仿真模型的正确性,对传动效率、转动惯量、摩擦系数等影响参数进行了分析。在此基础上,建立液力变速器机电液系统联合仿真模型,为换挡品质仿真做好准备工作。(3)对液力变速器机电液系统联合模型进行换挡品质仿真,分析了离合器换挡油压、换挡时间和动态换挡过程,并计算变速器换挡滑磨功。针对前进挡换挡过程中由于离合器充、泄油重叠时间太短而出现的动力中断问题,提出对电液控制系统进行改进,并对待分离离合器采取延迟换挡动作时刻和延长泄油时间的换挡品质控制策略。仿真结果表明,通过改进电液控制系统并采取一定的换挡品质控制策略可以避免换挡过程中产生动力中断,并减小换挡滑磨功,改善其换挡品质。(4)为了对液力变速器换挡品质进行试验,搭建了液力变速器试验台架,并对试验系统与试验方法进行了研究。在试验台上对变速器换挡油压、换挡时间及换挡滑磨功进行了试验,并与仿真进行对比,发现误差较小,验证了换挡品质仿真的正确性与可靠性,为进一步改善换挡品质提供了试验依据。由于在试验台上无法测试整机换挡冲击度,为了测试换挡冲击,在试验台上利用动态信号测试分析系统对液力变速器进行了换挡振动试验。分析了换挡过程中变速器三个方向的振动加速度,并以加速度均方根衡量换挡冲击。试验结果验证了换挡品质分析的正确性,同时为换挡品质改善提供了方法。
[Abstract]:The loader is one of the widely used construction machinery in the world road, mines, ports and other construction projects have played an important role. The loader working environment, working condition is complex, the driver needs to frequently shift operation to complete the loading operation, the driver's driving level is a severe test application of hydraulic transmission not only enhances the adaptability of the loader, and greatly improve the driver's driving operation. Therefore, the torque converter used in loader has become a mainstream trend. With the development of technology, put forward higher requirements on the loader performance. At present, the domestic loaders generally there are problems of shift quality, the shift of poor quality will not only cause the shift shock, but also increase the dynamic load of the transmission system, accelerate the wear of parts, reduce the service life of the parts. Therefore, to improve the loader Has the important significance of hydraulic transmission shift quality. Based on a certain type of hydraulic transmission as the research object, carries on the simulation of shift quality and the experiments are carried out. The main research contents and conclusions are as follows. (1) to determine the evaluation index for the shift quality of the degree of impact and the friction work and time shifting, and the factors shift quality are analyzed. The hydraulic transmission structure, shifting transmission route and electro-hydraulic control system is analyzed, combining with the working principle of stationary valve are studied, and focuses on the analysis of the hydraulic transmission of forward gear and reverse gear shift quality control strategy; establish the transmission shift process of the equivalent mechanical models of heat exchanger a process and torque inertia phase is studied, and analyzes each stage of the shifting clutch pressure to influence the shift quality, lays the foundation for the study of shift quality. (2) according to the hydraulic transmission The principle of electric hydraulic control system, the electro-hydraulic control system of hydraulic system simulation model using AMESim software for analysis of hydraulic clutch shift and shift time; hydraulic transmission test bench model based on a hydraulic transmission mechanical transmission system simulation model for analysis of clutch driven plate, rotational speed and friction torque, calculate the shift friction work; to ensure the correctness of the simulation model, the moment of inertia of the transmission efficiency, and effects of parameters of friction coefficient are analyzed. On this basis, the establishment of hydraulic transmission hydraulic system combined with simulation model, prepare for shift quality simulation. (3) for shift quality simulation of the joint model of hydraulic transmission for the mechanical and hydraulic system, analyzes the hydraulic clutch shift, shift time and dynamic shift process, and calculate the gear friction work. Aiming at the forward gear shifting process for clutch For filling, drain overlap and the emergence of the power interruption time is too short, the electro-hydraulic control system is improved, and the treatment of the separation of the clutch to delay and prolong the time shift action and shift quality control strategy of oil discharge time. The simulation results show that by improving the electro-hydraulic control system and adopt certain strategies can shift quality control to avoid the shift during power interruption, and reduce shift slipping power and improve the shift quality. (4) in order to test the transmission shift quality, build a hydraulic transmission test bench, and the test system and test method are studied. The test rig with hydraulic transmission, the test of friction power slide shift time and shift, and compared with the simulation, it is found that error is small, to verify the correctness and reliability of shift quality simulation, in order to further improve the shift quality provided The experimental basis. Due to the testing of the shift shock on the test bench, in order to test the impact of gear shifting, using dynamic signal test on the test bench analysis system for a shift of vibration test of hydraulic transmission. The analysis of vibration transmission in three directions during acceleration, and the acceleration RMS measure shift shock. The test results verify the correctness of shift quality analysis, and provides a method for improving the shift quality.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH243

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