Power Matching Analysis Of Wheel Loader Based On Typical Working Condition Test

Wheel loaders are widely used in shovelling and transiting soil operations due to its good mobility,high engineering efficiency and convenient operation.V-type operating conditions are typical conditions for the shoveling of the loader and the study of it is of great significance in understanding the performance requirements of the loader,improving the product,optimizing the design method,shortening the development cycle and so on.In order to analyze and study the specific working course,regular characteristics and to predict and simulate the dynamic performance of the loader in this typical working condition.Based on the test of shovelling fine gravel,according to the wheel loader test standard,of some domestic 50-type wheel loader in V-type operating cycle,the performance characteristics of the loader in V-type operating conditions is analyzed and studied in this paper.The engine,hydraulic torque converter,variable speed pump,working pump,steering pump,working device and other components in the V-type operation cycle show a cyclical law on basis of the test results,and they also show different performance characteristic at different stages in a single V-type operation.In this paper,the V-type operation is divided into 7 stages: G1 ~ G5 according to the working condition of the working device besides the division of it into five stages: V1 ~ V5 according to the traditional dividing method based on the driving state of the loader,which makes the regular characteristics of the working process more detailed.A dynamic matching method for loaders in the V-type operating condition is proposed in this paper on the basis of the rules of test data.According to the different characteristics of each stage of V1 ~ V5,this method proposes that the loader should be dynamically matched in each stage of V1 ~ V5.The dynamic matching method is suitable for different types of loader to shovel different materials in V-type operating condition.Based on the characteristic curve and Map of the engine,the original characteristic curve of the torque converter and the dynamic matching result of the test loader,the loader powertrain model is established by Amesim software.Based on the simulation model,not only the performance of the loader of static matching,such as the maximum speed,power shift points,can be simulated and analyzed,but also the rules of the dynamic characteristics of the loader at all stages of the V-type operation can be simulated and analyzed.In this paper,the dynamic characteristics of the torque converter are studied directed against the phenomen that the local difference between simulation value and experimental value of dynamic matching is slightly big.It is found that the greater the turbo angular acceleration,the greater the difference between the dynamic characteristics and the original characteristics of the torque converter,and the different range of the turbo angular acceleration will cause the deviation of the original characteristic torque ratio from the dynamic characteristic torque ratio different.According to the turbo angular acceleration curve calculated by the whole process test data of the loader in V-type operation,the use of the original characteristic curve of the torque converter for dynamic matching meets the requirement when the simulation accuracy requirement is not very high.However,when the overall research precision is high,it is necessary to consider the influence of the dynamic characteristics of the torque converter.