Study On Interaction Vibration Characteristics Of Hydraulic Hose Of 20T Type Excavator Main Pump

Fluid-structure interaction of pipelines has always been a concerned issue of scholars all over the world.In previous studies,fluid-structure interaction of metal pipes,such as aeronautical hydraulic pipes,was more addressed.However,in some construction machinery,such as excavators,hoses are mostly used to transfer energy oil media,especially the hydraulic hoses connected to the main pump outlet,will be dynamically excited.Long-term exposure to vibration environment will lead to a series of problems such as hose micro-crack or oil leakage.Therefore,the fluid-structure interaction vibration of such pipelines is also worthy of attention,which is not only conducive to the improvement of pipeline stability and reliability,but also of great significance in ensuring the working safety of excavators,In this paper,the hydraulic hose of the main pump of a 20 T type excavator is taken as the research object.The vibration law of the pipeline is determined by combining numerical simulation and test and the vibration reduction measures are proposed.The main research contents are as follows:(1)This paper summarize the background and significance of hydraulic pipeline system of construction machinery,and explains the harm of fluid-structure interaction vibration of pipeline.Firstly,The research results of pipeline fluid-structure interaction at home and abroad are deeply introduced from the aspects of vibration mechanism and dynamic model.Secondly,the industrial application and research status of hydraulic hose are introduced.(2)The superelastic constitutive model and viscoelastic constitutive model of hydraulic hose single rubber material are described,and the theory of hydraulic hose cord-rubber composite material is summarized.Based on the simple straight pipe fluidstructure interaction model,the fluid-structure interaction model of hydraulic hose considering the mechanics of composite material is established.(3)Using ACP module to design the composite laminated hydraulic hose of 20 T type excavator main pump,the solid model was obtained and the model analysis was carried out.The internal flow field characteristics and external structure field characteristics of the hydraulic hose under different working conditions were analyzed by building a two-way fluid-structure interaction simulation process.(4)On the whole machine of the excavator,the base vibration of the non-load pipeline,the vibration of the action performance in the flat ground mode and the vibration of the fixed pressure pipeline in the flat ground mode are tested respectively,and the time domain and harmonic curves of the pressure pulsation of the front and rear main pump and the acceleration of each vibration measuring point are obtained.The distribution characteristics of pipe vibration energy are analyzed and compared with numerical simulation to verify the rationality of the fluid-structure interaction model of composite hydraulic hose.(5)The fluid-structure interaction simulation process of composite hydraulic hose constrained by double pipe clamp was established.The influence of double pipe clamp on the dynamic characteristics of pipeline was obtained,and the comparison with the original pipeline was made to prove the role of reasonable arrangement of pipe clamp in suppressing the vibration of pipeline.