Study on Determination Method of Load Measurement Sample Length of the Loader Working Device

In order to determine the sample size in the load spectrum measure of the loader working device, the methods of the sample length determining were studied. The load test system of the loader working device was constructed and the original load time history data were collected. Considering the load characteristics and the confidence level of the population and the sample data, a new method was proposed and the minimum sample size required for the load test of the loader working device on ZL50 loader was 70 based on the measured load. The results of sample length of different methods were compared and analyzed. The new method presented in this paper was more reliable and credible than other methods. Methods and results to determine the test data is obtained, which provides a reference for the load test and life cycle spectrum compiling

STRUCTURAL STRENGTH ANALYSIS AND EXPERIMENTAL RESEARCH FOR WORKING DEVICE OF LOADER

In order to obtain the positions of load spectrum measuring points of the loader working device,the structural strength and fatigue strength of the working device were evaluated. The bucket force model was set up and the working device finite element model was builted. The method with typical operating conditions was used in simulation and experimental research on the structure strength analysis. The results showed that the simulation results agree well with the measured values,and the error of them between the 1. 6% 7. 3%,so as to effectively determine the load measuring point location area. Goodman fatigue limit diagram method was used to evaluate the fatigue strength of the measuring point. The results showed that the structure satisfied the requirements of fatigue strength. The static strength and fatigue strength evaluation were combined to obtain a more complete structural strength analysis method. Structural strength analysis and test results provide bases for the load spectrum test and fatigue life analysis of the loader working device

STUDY ON LOAD MEASURING METHOD AND TEST OF THE PIN-SHAFT IN LOADER WORKING DEVICE

Based on the mechanical force model of the bucket on the working device of loader,the problem of the dynamic loading test was analyzed. The testing method considering pin-shaft lateral dynamic force was put forward,and the 3D forces in horizontal,vertical and lateral direction of the loader working device were accurately measured. Without changing the loading characteristics of the working device,the pin-shaft dynamic force test system was established with the pin-shaft sensor design and the bucket structure modification. Primary soil containing granular iron ore was chosen as the shovel loading operation case,and the dynamic forces in three directions of the pin-shaft linking the arm and the bucket were acquired through the shovel loading test. The results show that: the dynamic testing method and the system could accurately obtain the dynamic loads of three directions of the pin-shaft; the dynamic loads of the three directions measured by the pin-shaft sensors are closely related to the loading process; the dynamic loads of the lateral force of the loader working device with the change of loading process were obtained firstly. It has important guiding roles for the study on the mechanical characteristics of the loader working device,the acquisition of the load spectrum and the prediction of fatigue life