装载机双泵轮液力变矩器性能及变能容匹配研究

发布时间：2018-06-06 14:22

本文选题：装载机 + 双泵轮液力变矩器　；参考：《吉林大学》2015年硕士论文

【摘要】：装载机是工程建设中广泛应用的铲土运输机械之一。装载机既有行驶工况又有铲装工况，发动机的输出功率需要在传动系统和液压系统之间进行动态合理分配才能满足使用要求。为了适应装载机复杂多变的工况，，通常在发动机与变速箱之间都装有液力变矩器，它与发动机之间的匹配决定了整机的动力性和燃油经济性。目前广泛使用的装载机液力变矩器的能容特性都是固定的。采用全功率匹配、部分功率匹配或折中优化匹配法设计的液力变矩器与发动机匹配时，行驶工况和铲装工况下装载机的匹配性能不能同时达到理想的效果。而双泵轮液力变矩器具有能容特性可变的特点，可将其用于解决装载机匹配问题。为了提升装载机整机性能，本文基于某7t装载机从双泵轮液力变矩器设计、特性预测、匹配性能等方面对装载机变能容匹配技术进行了研究，主要内容和结论如下。（1）通过分析装载机的工况，设计了带有滑差离合器的双泵轮液力变矩器以代替原装三元件液力变矩器。采用相似法设计了双泵轮液力变矩器的基准型，其有效直径为425mm。对基准型的泵轮叶片进行分割得到了双泵轮液力变矩器主泵轮叶片和辅助泵轮叶片。设计了滑差离合器的结构和液压控制系统，分析了双泵轮液力变矩器变能容控制方法。（2）采用CFD数值仿真方法计算了不同滑差率和转速比下双泵轮液力变矩器各工作轮的转矩，分析了双泵轮状态、单泵轮状态、滑差状态下双泵轮液力变矩器的性能。通过建立滑差离合器受力平衡方程、计算双泵轮液力变矩器侧腔压力，得到了滑差离合器的转矩特性。结合双泵轮液力变矩器的转矩特性和滑差离合器的转矩特性，求解出不同压力控制规律下双泵轮液力变矩器的原始特性，为装载机变能容匹配特性分析奠定了基础。（3）建立了发动机和双泵轮液力变矩器的数学模型，分析了换装双泵轮液力变矩器对共同工作输入特性、输出特性的影响。建立了发动机与双泵轮液力变矩器动态变能容匹配仿真模型，对装载机变能容匹配过程进行了仿真，分析了一个作业循环内换装双泵轮液力变矩器对匹配性能参数的影响。静态和动态变能容匹配特性分析结果表明，与原机相比，换装双泵轮液力变矩器后，铲装工况下装载机的匹配性能无明显变化，行驶工况下装载机的匹配性能得到了显著改善。动力性和燃油经济性计算结果表明，与原机相比，换装双泵轮液力变矩器后整机的动力性和燃油经济性均得到了显著提高。研究表明，双泵轮液力变矩器与发动机之间的变能容匹配能够同时满足两种典型工况下装载机的使用要求，有效地提升装载机整机性能。
[Abstract]:Loader is one of the widely used shoveling and transportation machinery in engineering construction. The loader has both driving and shoveling conditions. The output power of the engine needs to be distributed dynamically and reasonably between the transmission system and the hydraulic system in order to meet the operational requirements. In order to adapt to the complex and changeable working conditions of the loader, a hydraulic torque converter is usually installed between the engine and the gearbox. The matching between the engine and the engine determines the power performance and fuel economy of the whole engine. At present, the energy capacity characteristics of load loader torque converter are fixed. When the hydraulic torque converter designed by full power matching, partial power matching or eclectic optimization matching is matched with the engine, the matching performance of the loader under both driving and shovel conditions can not achieve the ideal effect simultaneously. The dual pump wheel torque converter has the characteristics of variable energy capacity and can be used to solve the load matching problem. In order to improve the performance of the loader, based on the design, characteristic prediction and matching performance of a 7t loader, the variable energy capacity matching technology of the loader is studied in this paper. The main contents and conclusions are as follows. 1) by analyzing the working conditions of the loader, a hydraulic torque converter with two pump wheels with slip clutch is designed to replace the original three-component hydraulic torque converter. The reference type of double pump wheel hydraulic torque converter is designed by using similarity method. Its effective diameter is 425 mm. The vane of the main pump wheel and the auxiliary pump wheel of the double pump wheel hydraulic torque converter are obtained by dividing the reference type pump wheel vane. The structure and hydraulic control system of slip clutch are designed, and the energy capacity control method of hydraulic torque converter with double pump wheel is analyzed. CFD numerical simulation method is used to calculate the torque of each working wheel of double pump hydraulic torque converter under different slip rate and speed ratio. The performance of double pump wheel hydraulic torque converter is analyzed under the condition of double pump wheel state, single pump wheel state and slip state. By establishing the force balance equation of slip clutch, the side cavity pressure of hydraulic torque converter with double pump wheel is calculated, and the torque characteristic of slip clutch is obtained. Combined with the torque characteristics of hydraulic torque converter with double pump wheels and the torque characteristics of slip clutch, the original characteristics of hydraulic torque converter with double pump wheels under different pressure control laws are solved, which lays a foundation for the analysis of load loader variable energy capacity matching characteristics. The mathematical model of hydraulic torque converter for engine and double pump wheel is established, and the influence of replacing double pump wheel hydraulic torque converter on the input and output characteristics of the joint operation is analyzed. The simulation model of dynamic energy capacity matching between engine and double pump wheel hydraulic torque converter is established. The process of energy change matching of loader is simulated, and the effect of changing hydraulic torque converter with double pump wheel on matching performance parameters is analyzed. The analysis results of static and dynamic variable energy capacity matching characteristics show that the matching performance of loaders under shovel loading condition has no obvious change, and the matching performance of loaders under driving conditions has been significantly improved compared with that of the original one. After the replacement of hydraulic torque converter with double pump wheels, the matching performance of loaders under shovel loading condition has no obvious change. The results of power performance and fuel economy calculation show that the power performance and fuel economy of the whole machine after the replacement of double pump wheel hydraulic torque converter have been significantly improved compared with the original engine. The research shows that the variable energy capacity matching between the hydraulic torque converter and the engine can meet the requirements of the loader under two typical working conditions and effectively improve the performance of the loader.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH137.332;TH243

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