Research On Performance Test System Of Hydraulic Impactor Based On PXI

Hydraulic impactor is an important construction machinery,which can reliably complete the work of rock and road breaking,old city reconstruction,etc.Through the transformation of hydraulic energy and kinetic energy,so it is widely used in metallurgy and infrastructure industry.The performance test of hydraulic impactor is an important prerequisite to ensure stable operation.At present,there are no unified standards and regulations for the performance test of hydraulic impactors in China,and each manufacturer has its own test methods.Because of the diversity of testing methods,the testing equipment of hydraulic impactor can not be used in common and the cost performance is low.The traditional test equipment,which is represented by sensor-oscilloscope,has limited analysis ability on collected data and is not convenient for data exchange.For this reason,this paper proposes a performance test method based on virtual instrument technology and PXI platform,designs a virtual test system to simplify the test process and improve the versatility and cost performance of the equipment.Firstly,the structure and working principle of the hydraulic impactor are introduced,and the typical nonlinear mathematical model of the hydraulic impactor is analyzed.The motion balance equation of the piston and the valve,the system flow balance equation and the gas state balance equation are established,which provides the theoretical basis for the establishment of simulation model and the principle of the test system.Secondly,based on AMESim,the motion simulation model of the hydraulic impactor is established.Through the analysis of the model,the motion law of the piston is obtained,and the influence of the working parameters on the performance of the hydraulic impactor is demonstrated based on the control variables.At the same time,the orthogonal test scheme is designed to explore the influence of the structural parameters on the performance parameters.From the five important structural parameters,the most important conclusions of the parameters of the front and rear cavity size and the piston mass on the performance of the hydraulic impactor are obtained.The simulation model theoretically analyzes the influencing factors of the performance of the hydraulic impactor,which provides an important reference for the subsequent experimental test.Thirdly,the shortcomings of the traditional hydraulic impactor test system are analyzed,and the virtual test system based on PXI platform is proposed and designed,including the selection and connection of hardware system and the programming of software system.The hardware system is mainly built around pxi-8101 controller and pxi-6238 acquisition card;the software system is compiled by Lab VIEW,and the data acquisition module,performance analysis module and data communication module are designed through the modular idea.Among them,the data acquisition module is compiled by DAQmx function library,which has the functions of signal scale change,filtering and storage;the performance analysis module takes nitrogen pressure method as the principle,automatically generates the piston speed,displacement and impact energy curve of the hydraulic impactor by collecting signals,and finally calculates the impact frequency;the data communication module realizes the remote transmission of the analysis data through Data Socket technology.Finally,the performance test bench of the hydraulic impactor is built to verify the virtual test system.The data of hydraulic impactor in the state of no load and full load are collected in the experiment.Compared with the simulation model and theoretical value,it is proved that the system can effectively collect the working parameters of the hydraulic impactor,and then calculate the required performance parameters.Finally,the conclusion that increasing the flow rate can improve the performance of hydraulic impactor is verified by flow control.