Multi-state Steady State Simulation And Experimental Study Of Multi-way Valve For Excavator

Excavator has many functions,wide application.It is the most valuable variety among all kinds of construction machinery,occupying a large market share.The hydraulic system of the excavator determines the performance of the excavator,and the core component of the whole hydraulic system,multi-way valve,plays a key role.With the increase of the flow and pressure required by the main engine of the excavator,the sensitivity,stability and reliability of the multi-way valve are required to be higher and higher.Aiming at the problems of heat,vibration and noise during the operation of the multi-way valve of the excavator,the purpose of the project is carry out flow field simulation analysis,fluid-solid coupling analysis and experimental research on a multi-way valve of excavator,summarize the rules of parameter change,and verify the rationality of the scheme in advance.It has a certain guiding role in improving the design theory of multi-way valve of excavator,this method is very important to improve the performance of hydraulic excavator.Firstly,this paper analyzes the research status of multi way valve,throttling groove theory and multi-way valve hydraulic comprehensive test-bed.The current research lacks the flow characteristic research under the single throttling groove and coupling action of throttling groove of valve port.It does not involve the fluid-solid coupling analysis in the process of valve spool opening and the comparative analysis of test and simulation for different valve spool schemes.In this paper,the above problems will be carried out targeted research.Secondly,the pressure loss of multi-way valve and the stress of valve spool are calculated.This paper analyzes the structure and flow characteristics of the typical throttle groove at the valve port of the slide valve,sums up and summarizes the change rule of the valve port area of the typical throttle groove,and through the Matlab software,the change rule of the flow area at the bucket spool valve port of the multi-way valve is presented in the form of curve.Using Fluent software to simulate the flow field of the multi-way valve bucket under the working condition,it is found that the vortex phenomenon often exists around the corner of the high velocity region and the fluid region,which will cause the oil energy loss and cavitation phenomenon.It can be seen from the curve of velocity,pressure of the throttling groove and flow force that the sudden increase and drop often occur during the opening process of the valve spool,which makes the multi-way valve produce vibration and noise,and affect the working performance and service life of multi-way valve.This method can predict possible risks and deficiencies in advance,thereby improving optimization work efficiency and reducing improvement costs.Using Workbench software,the fluid-solid coupling analysis of single action and complex action of multi-way valve is carried out.It is found that the deformation of valve body and valve spool mainly exists in the position of oil delivery section,and there is stress concentration at the edge of valve body and valve spool.As the working condition becomes more and more complex,the stress of P1 valve block decreases,P2 valve block increases,and the stress of bucket valve spool increases.The trend of P2 valve block and bucket valve spool shows a positive correlation.The static analysis of the valve body and valve spool of the multi-way valve is performed through the equivalent stress,strain,and deformation parameters and their cloud diagrams.It can be verified in advance whether the materials and structures used are reasonable,and whether the stress concentration and deformation prominent areas exist.Design a multi-way valve comprehensive test bench,which can test related working performance and leakage.Through the test bench,the dynamic performance of the four schemes of the multi-way valve bucket spool was tested,and it was found that the four schemes have different flow adjustment characteristics and will be suitable for excavators with different functions.Through the comparative analysis of experiment and simulation,the accuracy of the simulation results is verified.This paper has carried out a comprehensive analysis of the multi-way valve from the perspective of theoretical analysis,mathematical model,flow field analysis,fluid-solid coupling analysis,and test verification.It provides theoretical support and reference for improving the research of the multi-way valve of the hydraulic excavator.