| Backhoe loader is a kind of construction machinery with two functions of excavating and loading.Different from general construction machinery which has only one working end in its structure.It has one working end in front and one working end in the back,so it is also called “two ends busy”.The outstanding features of the Backhoe loader are high flexibility and strong function integration.It can realize multi-purpose of one machine.Although Backhoe loaders have unique advantages in use,their usage rate in China is relatively low due to various reasons.With the construction of public infrastructure in our country entering a stage dominated by small and medium-sized projects,the use advantages of Backhoe loaders are increasingly prominent and the application prospect is unprecedented.Therefore,in order to meet the requirements of the market,a task of the top priority is to increase scientific research investment in Backhoe loaders,and improving the performance of working devices is an important part.Research on the working device of Backhoe loader can not only improve the structural rationality of the working device itself,increase the service life of the working device and even the whole machine,but also help to promote energy conservation and consumption reduction,improve the use efficiency of Backhoe loader,and finally achieve the purpose of maximizing economic benefits and ecological benefits.In this paper,the loading device of WZ30-25 Backhoe loader is taken as the research object,so as to clarify the interaction relationship between the loading device and external load,analyze the overall motion characteristics of the loading device and the stress-strain characteristics of its components,and explore the dynamic external load change law and its influence on the loading device during the loading operation of the Backhoe loader.Firstly,according to the existing theory and practical application,on the basis of studying the structural form and motion principle of the reverse six-link loading device of Backhoe loader,the working stage of the loader and its action posture in different stages are defined,and different types of external loads acting on the bucket are analyzed.The stress analysis is made on the main components of the loading device according to the specific external load,and the stress transfer model between the external load and the bucket is established as the theoretical basis for later research.Secondly,the virtual prototype of the loading device is established by using a variety of software and the dynamic analysis and static analysis related to it are completed.The simulation software ADAMS / View2016 is used to test the kinematics and dynamics of the virtual prototype of the loading device,to verify the motion track characteristics of the loading device and to obtain the maximum stress value of the key points of the loading device,that is,the work hazard value.The simulation software Ansys2019R3 is used to carry out finite element analysis on each component model,and the dangerous position of each component under load is found through checking the maximum values of stress and strain.Thirdly,the prototype experiment method is used to analyze the dynamic external load variation law of Backhoe loader in actual loading operation.According to the simulation and stress analysis of loader loading device of Backhoe loader,a dynamic external load real-time induction system is designed and assembled,and the periodicity and periodic law of dynamic external load data change are analyzed,so as to determine the dangerous working state of loading device.Finally,the key points for attention in the structural design of the loading device are obtained by summarizing the research topics,and the influence of external load on the fatigue strength of the loading device and its components is clarified.Looking forward to the research trend of applying standard load spectrum to the loading device of Backhoe loader. |
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