Research On Profiling Measurement Technology Of Wheel Tread Wear

The wear of the wheel tread will affect the interaction between the wheel and the rail,resulting in the impact of the wheel on the rail,the adhesion between the wheel and rail,the easy slippage of the wheel and the reduction of the braking performance,which affects the safety of the train operation.Therefore,the wheel tread needs to be tested regularly or regularly to determine if it needs to be repaired or replaced,so as to reduce potential safety hazards and ensure vehicle safety.In this paper,based on the comprehensive analysis of the existing wheel tread detection methods and instruments,a portable wheel tread wear detection device based on a laser displacement sensor is studied.The main contents are as follows:Firstly,through the analysis and comparison of the measurement characteristics of the direct-type and oblique-type laser displacement sensors,combined with the characteristics of the wheel tread contour and the detection technology requirements,a profiling measurement scheme using a direct-type displacement sensor is proposed.The trajectory of the scanning measurement of the sensor is changed from a straight line to a standard profile curve of the wheel tread,which reduces the requirement for the entire measuring range of the sensor to effectively measure the range of the sensor,and is beneficial to improving the measurement accuracy and resolution.Secondly,according to the profiling measurement scheme,a profiling movement mechanism composed of a standard tread contour profile guide rail,a bearing,a spindle nut pair,and a V-ball guide rail are designed.The physical model of the profiling movement mechanism was established using the three-dimensional modeling software Solid Works.The physical model was imported into ADAMS for dynamic analysis.The displacement,velocity and force of the profiling movement in all directions were given.On this basis,the boundary conditions of the finite element analysis were determined,and ABQUS was used to perform finite element analysis on the key parts of the profiling mechanism—profile guides,which verified the rationality of the guide rail design and material selection.Third,designing a prototyping measurement experimental device prototype.The profiling measurement movement is driven by a stepper motor and the nut moves linearly.Under the action of the profiling movement mechanism,the sensor can move in the direction perpendicular to the movement of the nut while moving with the nut to achieve a two-dimensional profilometry measurement.For the characteristic of large changes in the slope of the wheel profile curve,the sensor is installed obliquely so that the measuring beam of the sensor is installed relative to the Y axis inclination of the profile coordinate system of the tread,and the relationship between the incident angle of the measuring beam of the sensor and the measurement error is obtained through experiments.Tilt installation provides the basis.Fourth,based on Lab VIEW design stepper motor control program and sensor measurement data acquisition program,the signal transmission by NI ELVES ?~+.A prototype of a tread wear profiling measurement device independently developed by the company was used to perform a real wheel tread measurement experiment.In the case of sensor installation angles of 30°,35° and 40° respectively,the profile measurement experiment results agree well with the actual tread profile curve of the tested wheel,which verifies the feasibility and effectiveness of the profiling detection device.The establishment of the product of the measuring device has laid the foundation.