Design Principle And Analysis Of 20-Ton Excavator Multi-Way Valve Travel And Rotary Oil Path

Multiway valve is one of the key parts of excavator hydraulic transmission system,whose performance determines the stability of excavator whole machine.The internal layout of the valve body and the design of the main spool orifice form determine the operating performance of the multiway valve to a large extent.Applying CAE computer to solve complex engineering,the flow characteristics of the internal oil circuit and throttle orifice of the multi-way valve are analyzed,and the flow state,velocity,pressure loss and other parameters of the liquid can be known,which is helpful to the structure design and analysis of the multi-way valve oil circuit and the main spool valve orifice.In this paper,a 20 ton excavator electronic control multiway valve as the research object,using the method of combining theoretical calculation and computer simulation,firstly from the whole aspect of the multiway valve structure,working principle and function characteristics are explained,the excavator walking and rotary oil circuit working principle is analyzed,and extract the internal oil circuit diagram;Secondly,the main structural parameters of the valve body are calculated and designed theoretically,including the diameter of the oil inlet and outlet,the maximum and minimum diameters of the valve core,the force analysis of the valve core,the calculation of the flow area inside the valve body and pressure loss,and the key position of the oil circuit inside the valve body size and shape transformation are analyzed and explained.Finally,the orifice forms of the moving spool and the rotating spool are analyzed in detail,and the formula is derived and calculated.The mathematical models of the displacement of the spool and the equivalent flow area are established,and the curves of the displacement and equivalent flow area are drawn.According to the changing rules of the curves,the walking process and the rotating process of the excavator are described in detail.Three-dimensional drawing software Solidworks was used to extract the traveling oil path and rotating oil path inside the multiway valve,and the computational fluid dynamics analysis software Fluent was used to simulate the oil path,and the pressure field,velocity field,turbulent kinetic energy and other parameters inside the traveling oil path and rotating oil path were obtained.Intuitively observe the flow rate,pressure and other parameters in the valve body oil circuit and the position of drastic changes.Through the calculation of Fluent fluid dynamics analysis software,the oil pressure distribution in the travelling oil circuit and the rotating oil circuit was obtained.Using the fluid-structure coupling function provided by the finite element software Workbench,the oil circuit pressure was applied to the oil circuit surface of the multichannel valve body.After the valve body was divided into grids,the equivalent stress and strain of the valve body was obtained through computer calculation.And the position of the valve body with the greatest stress and deformation.Finally,according to the mechanics of materials,elasticity and finite element basis,the strength value and deformation value of the multiplex valve body are compared and judged with the standard value of the material.