The Design Of Loader Multiple Valve And Research Of Valve Spool Open Characteristics

Engineering machinery hydraulic system operation reliability, safety, comfort, energy saving and environmental comfort and depends largely on the performance of the hydraulic control valves.This thesis in some type of wheel loader flow corundum (multiple directional control valves for background, analyzed and summarized the main control hydraulic engineering machinery by deep into the hydraulic control valves internal flow field and the dynamic behavior of the level, design method to improve the design efficiency. Loader working device for hydraulic system is established using AMESim, the model of multiple valve of the main valve spool open process is analyzed through numerical calculation, the various factors on the main valve spool open process. Provide the theory basis for analysing the main valve spool open process, also for similar structure design and calculation of rotary provides a certain reference. Based on this,analysis of the opening of cylinder movement characteristics, the results showed that pilot pressure is the main factor of velocity and acceleration of cylinder piston,the characteristic of main valve spool and cylinder movement has good uniformity.The main content of this thesis:In chapter 1,the background and significance of this thesis is presented. Overview of domestic and foreign construction machinery hydraulic research status, the main research subjects are presented.In chapter 2, analysis of the wheel loader hydraulic system works and the basic parameters, obtained matching the main structure of multiple parameters of valve, valve orifice area and so on, for the follow-up multi-way valve to provide a basis for specific design.In chapter 3, many of the typical structure of relief road is introduced, using UG software to make the body shape,realizing the calculation method of the sequencing of the valve through Mathcad, the valve road area, the numerical analysis of valve with the change of heart valve displacement curve.In chapter 4, Introduced a major supporting multi-valve device, including the main relief valve, overload relief valve, overload fill valve, fill valve and check valves and other valve components.For the auxiliary valve structure, working principle is analyzed.In chapter 5, the model of multiple valve is made by AMESim, and the main valve spool open process is analyzed through numerical calculation, the various factors on the main valve spool open process. Numerical results show that:the pilot pressure is the main factor when open, and open to guide the size of the stress rate sensitive reaction, combined with spring stiffness springs and compression carries on the reasonable configuration.At the end, some conclusions in this thesis are summarized and the future research proposals are suggested. Based on this,analysis of the opening of cylinder movement characteristics, the results showed that pilot pressure is the main factor of velocity and acceleration of cylinder piston,the characteristic of main valve spool and cylinder movement has good uniformity.