Research On Impact Suppression Method Of Two-Way Cartridge Valve Hydraulic System Of Concrete Pump

Concrete pump is widely used in building construction,bridge construction,tunnel construction and other projects,which greatly improves the quality and efficiency of construction.With the development towards high pressure,large displacement and energy saving of concrete pump,the flow rate of hydraulic system is increasing,which requires larger diameter of directional valve and smaller pressure loss.Two-way cartridge valve has the advantages of large flow capacity and small pressure loss,which is suitable for large displacement concrete pump system.Some domestic enterprises have carried out engineering application,but found that there are problems of large reversing impact and short service life of components.This paper is aimed at solving the problem of this troubled industry research,expect two-way cartridge valve system can replace the existing sliding valve system with excellent performance,the main work of this paper is as follows :(1)The commutation impact and load characteristics of the main pump system and the swing system were analyzed.Firstly,the hydraulic principle of concrete pump composed of traditional slide valve is analyzed.On this basis,a new hydraulic system of concrete pump composed of twoway cartridge valve is designed,which is the basis of researching the impact problem of the new hydraulic system.By analyzing the hydraulic impact of the concrete pump during reversing,it is concluded that the flow characteristics of the two-way cartridge valve should be improved to reduce the hydraulic impact during reversing.Then,based on the rheological principle,the flow state and pressure loss of concrete in the conveying pipe were analyzed,and the load model of the main pump system was established.Finally,according to the working principle of the swing system,the swing mechanism is simplified,and the swing load is calculated,which provides the basis for the subsequent establishment of the system model.(2)According to the flow formula of two-way cartridge valve,the flow characteristics of two-way cartridge valve are improved by reasonably setting throttle hole and reducing valve core cone angle.The simulation model of two-way cartridge valve is established based on AMEsim simulation software.The improvement effect of throttle hole and valve cone angle on the flow characteristics of cartridge valve is simulated and analyzed,and the influence of other factors on the flow characteristics of two-way cartridge valve is analyzed.(3)The simulation models of the main pump system and the swing system were established.Through simulation,the influence of the flow characteristics of the two-way cartridge valve on the reversing impact of the main pump system and the swing system was verified.The hydraulic impact in the main pump system and the swing system during the reversing of the two-way cartridge valve can be effectively suppressed by reasonably setting the throttle orifice size,selecting smaller spool cone angle,and appropriately reducing the spool area ratio.(4)The experimental platform of the two-way cartridge valve pump system was built,and the hydraulic impact of the main pump system before and after the improvement was compared to verify the correctness of the theoretical analysis and the effectiveness of the suppression method.