Study On Static And Dynamic Characteristics Of LHDV Counterbanlance Valve

As a traditional load control valve,the balance valve can also be described as a safety valve,which has been widely used in hydraulic balance circuits.At present,the balance valve has developed into a motion control component that is integrated with anti-shock,load controllable,shock absorption and decompression,and lock load.In the hydraulic system,the balance valve can effectively protect the system mechanism,ensure the smooth operation of the machine,and can effectively meet the operational requirements of all aspects of the construction machinery.Therefore,analyzing the dynamic performance of the balance valve plays an extremely important guiding role in the practical engineering application of the balance valve in social production.This paper takes HAWE-LHDV 33P-15-B 6-300/230 type balance valve as the research object.Using theoretical analysis combined with mathematical modeling and numerical simulation,the research on the influence of the dynamic characteristics of the balance valve was carried out from three aspects:de sign structure parameters in asymmetric damping network structure;pilot piston seal sealing problem;pilot cavity and bypass cavity size.The main contents of this paper are as follows:Chapter one:Mainly introduces the application of balance valve in engineering machinery production equipment,and gives a brief overview of the research direction and background significance.Chapter Two:This chapter mainly analyzes the working principle of Hawe's LHDV balance valve,analyzes the structural characteristics of the 3D model and studies the layout characteristics to understand the advantages and disadvantages of the LHDV balance valve.Chapter Three:Through the application of the LHDV balance valve in the hydraulic circuit system,the mathematical model of the balance loop system with the balance valve is theoretically established.And a linear mathematical transfer function model is established by using the orifice flow in the system and the flow equation of each control chamber and the force balance equation of each part.Finally,the mathematical model is simplified,and the key parameters affecting the dynamic performance of the balance valve are analyzed from the model.Chapter four:Firstly,the opening ratio of the balance valve is calculated,and the influence of the opening ratio on the movement of the balance valve spool is analyzed.Then the relationship between structural parameters of the balance valve and system fluctuations is found by simulation,and the influence of key internal structural parameters on the dynamic performance of the balance valve in the asymmetric damping network of the balance valve is analyzed.Chapter Five:It mainly discusses the influence of the pilot valve pilot cavity and the bypass cavity on the dynamic performance of the balance valve under different cavity sizes,which provides a reference for the structural design of the balance valve.Chapter Six:Mainly discusses the problem of seal friction caused by the pilot piston seal and the influence on the dynamic performance of the balance valve.The influence of the friction caused by different materials and the same material under different compression margins on the dynamic performance of the balance valve is discussed.