CN111288922A - On-machine measurement method for rail vehicle wheel and tread profile - Google Patents

Abstract

An on-machine measurement method for rail vehicle wheel and tread profile, which adopts a decentralized measurement modular structure, and is connected in parallel according to data interface rules. Each decentralized measurement module includes two one-dimensional laser displacement sensors, and the two one-dimensional laser displacement sensors pass through The moving axis moves axially at the same time, and the measurement is realized by using the Z-axis position signal on the machine tool or by adding a secondary Z-axis, and the X-axis is directly used on the measuring machine to realize the measurement; the on-machine measurement method includes the measurement of the radial profile of the wheel and the measurement of the wheel Measurement of the axial profile of the tread; the invention simplifies the measurement structure, improves the measurement accuracy, and effectively improves the measurement accuracy and work efficiency.

Description

On-machine measurement method for rail vehicle wheel and tread profile

technical field

The invention belongs to the technical field of rail vehicle wheel measurement, and in particular relates to an on-machine measurement method for rail vehicle wheels and tread profiles.

Background technique

As a key component of the running part, the wheel of a rail vehicle has a crucial impact on the running stability of the vehicle. During operation, the wheel and tread profile will be deformed due to uneven wear of the wheel, which is commonly found in subway, light rail, ordinary and high-speed trains. The deformation of the wheel and tread profile not only increases the vibration of the vehicle and increases the running noise, but also increases the mutual impact between the wheel and the rail, causing serious damage to the rail and vehicle components, posing a serious threat to the safe operation of the vehicle. At present, the restoration of the geometric profile of the wheel and tread profile is mainly guaranteed by the repairing process. Therefore, the topography measurement of the wheel and tread profile is the key to ensure the accurate restoration of the wheel profile. At present, the measurement equipment of wheel and tread profile is mainly offline and portable measurement instruments, which are inconvenient to operate and have low measurement efficiency. In addition, the measurement accuracy is difficult to improve due to the non-uniform measurement standards.

In view of the on-machine measurement requirements of wheelset online repair and wheel tread profile, combined with wheelset processing machine tools (drop-wheel machining center, non-drop-wheel processing machine tool), wheelset measuring machine (on-orbit measuring machine, wheel shape measuring center) The processing method of special equipment such as wheelset needs to realize the integration of wheelset processing and measuring machine, and the key to integrated measurement lies in the combination of measurement scheme and measurement equipment. Optimizing the measurement structure and measurement method is the basis for the realization of wheel shape on-machine measurement. At the same time, it can also improve the measurement accuracy and precision of the wheel and tread profile.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an on-machine measurement method for the wheel and tread profile of a rail vehicle, which can not only measure the axial profile of a single wheel by using dual laser displacement sensors, but also Measurement of radial topography; simplify the measurement structure and improve the measurement accuracy, and effectively improve the measurement accuracy and work efficiency.

In order to achieve the above object, the technical scheme adopted in the present invention is:

An on-machine measurement method for the wheel and tread profile of a rail vehicle, which adopts a decentralized measurement modular structure, and is connected in parallel according to data interface rules. Each decentralized measurement module includes two one-dimensional laser displacement sensors, and the two one-dimensional laser displacement sensors pass through The movement axis moves axially at the same time, and the measurement is realized by using the Z-axis position signal on the machine tool or by adding a secondary Z-axis, and the X-axis is directly used on the measuring machine to realize the measurement;

The on-machine measurement method includes the measurement of the radial profile of the wheel and the measurement of the axial profile of the wheel tread;

The measurement of the radial profile of the wheel includes the following steps:

The laser displacement sensor S1 and the laser displacement sensor S2 form a single wheel measurement unit, in which the measurement position of the laser displacement sensor S1 is consistent with the vertical centerline of the wheel to be measured, and the linear distance between the fixed laser displacement sensor S1 and the laser displacement sensor S2 is L. The displacement measurement difference of the person is d2-d1, and the radial radius of the wheel is obtained as:

When the wheel rotates, collect i measuring points on the circumference of the wheel, obtain the radial offset of the wheel as R _i , and rotate the wheel according to the set angle to obtain the function R _j about the radial movement of the wheel, and its expression is:

R _j =R _j (θ _j )

Then the wheel radial R _i or R _j is denoised and smoothed, and the output data is used to evaluate and analyze the out-of-roundness and noise intensity of the radial profile of the wheel tread contact line.

The measurement of the wheel axial tread profile includes the following steps:

Two laser displacement sensors measure the wheel tread profile along the Z-direction guide rail. The measurement of the wheel axial tread profile requires two position signals, one of which is derived from the output signal d _i of the laser displacement sensor S1, where i is the sampling point The other position signal comes from the Z-direction guide rail linear grating output signal is e _i , 0≤e _i ≤H; the two sets of position signals constitute the measuring point coordinates of tread and wheel rim contour Q _i (e _i , h _i );

Taking the contact line of the tread as the coordinate origin, the measurement data is preprocessed, and then the equivalent taper of the tread is calculated according to the Kingel formula,

In the formula, λ is the wavelength of the motion track of the wheelset; e is the distance between the left and right wheel-rail contact spots, that is, the span _; R0 is the wheel rolling circle radius when the wheelset is in the center position; γ _e is the wheel The taper angle of the tread; tanγ _e is the equivalent taper of the wheel tread;

At the same time, the QR value of the wheel rim is calculated using the converted data to obtain the deviation between the measured contour and the standard contour, and the wear amount of the wheel rim is obtained.

The two laser displacement sensors of the decentralized measurement module are mounted on a sensor bracket, and the sensor bracket is connected with the machine tool Z-axis, or constitutes a measurement axis independently.

The beneficial effects of the present invention are:

1. The present invention uses two laser displacement sensors to measure a single wheel, and has the advantages of simple and reliable measurement structure and high measurement accuracy;

2. The present invention can obtain the axial profile signal of the entire circumference of the wheel through the wheel rotation measurement, and this measurement method can be directly applied to machine tools, wheel shape measuring machines and other on-line equipment under the requirement of physical space;

3. The present invention can not only be used for the measurement of the profile of the rail vehicle wheel, but also can be applied to the performance evaluation of the profile of the vehicle wheel.

Description of drawings

FIG. 1 is a schematic diagram of a decentralized measurement module of the present invention.

Fig. 2 is a schematic diagram of the present invention for measuring the radial profile of a wheel.

Fig. 3 is a schematic diagram of the present invention for measuring the profile of the axial tread of a wheel.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments. Specifically, the present invention will be described with reference to the non-drop wheel repairing machine tool. Each wheel is measured by two laser displacement sensors, and the radial profile of the wheel can be obtained, which can effectively reduce the difficulty of realizing the structure of the measuring device on the machine tool, and improve the measurement accuracy and the processing efficiency of the machine tool.

An on-machine measurement method for rail vehicle wheel and tread profile, which adopts a decentralized measurement modular structure, and performs parallel splicing according to data interface rules, which reduces the complexity of multi-unit measurement and facilitates expansion; each decentralized measurement module includes two one-dimensional measurement modules. Laser displacement sensor, two one-dimensional laser displacement sensors move axially through the motion axis at the same time, use the Z-axis position signal on the machine tool or add the auxiliary Z-axis to achieve measurement, and directly use the X-axis on the measuring machine to achieve measurement; due to the rotation of the wheel. Realize the acquisition of signals, so it meets the requirements of traditional on-machine measurement;

As shown in FIG. 1 and FIG. 2 , two laser displacement sensors in this embodiment are mounted on a sensor bracket, and the sensor bracket can be connected to the Z-axis of the machine tool, and can also form a measuring axis independently. The measurement resolution of the selected laser displacement sensor should be lower than the measurement accuracy specified in the UIC-519 standard, and the resolution of the Z-axis moving linear grating ruler should also be lower than the accuracy required for the measurement of the axial tread profile. Located at the lowest point of the wheel arc under test, the installation position of the laser displacement sensor S2 should be at the same level as the installation position of the laser displacement sensor S1, with a certain distance from each other; according to the actual application, the resolution of the laser displacement sensor is 5μm, and the frequency response is 500Hz, the linearity is less than 0.05%, and the maximum data sampling frequency is 2kHz.

The on-machine method for measuring the wheel and tread profile of a rail vehicle includes the following steps;

1) Install the laser displacement sensor on the sensor bracket and calibrate the sensor position;

2) Calibrate the position of the laser displacement sensor and determine the sensor position coefficient;

3) Adjust the measurement position to ensure that the measurement position of the laser displacement sensor is at the lowest point of the measured arc of the wheel;

4) Connect the controller and signal acquisition system;

5) The controller drives the sensor bracket to move, and moves the laser displacement sensor to the position of the wheel tread contact line for contour measurement;

6) As shown in Figure 2, the laser displacement sensor S1 and the laser displacement sensor S2 form a single wheel measurement unit, in which the measurement position of the laser displacement sensor S1 is consistent with the vertical centerline of the measured wheel, and the laser displacement sensor S1 and the laser displacement sensor S2 are fixed. The straight-line distance between them is L, the displacement measurement difference between the two is d2-d1, and the radial radius of the wheel is obtained as:

When the wheel rotates, collect i measuring points on the circumference of the wheel, obtain the radial offset of the wheel as R _i , and rotate the wheel according to the set angle to obtain the function R _j about the radial movement of the wheel, and its expression is:

R _j =R _j (θ _j )

Then the wheel radial R _i or R _j is denoised and smoothed, and the output data is used to evaluate and analyze the out-of-roundness and noise intensity of the radial profile of the wheel tread contact line;

7) As shown in Figure 3, the laser sensor takes the tread contact line as the zero point, and the laser displacement sensor measures the wheel tread profile along the Z-direction guide rail. The measurement of the wheel axial tread profile requires two position signals, one of which is derived from the The output signal d _i of the laser displacement sensor S1, where i is the number of sampling points; the other position signal comes from the Z-direction guide rail linear grating output signal is e _i , 0≤e _i ≤H; the two sets of position signals constitute the tread and The coordinates of the measuring point Q _i ( _ei , _hi ) of the rim profile;

Taking the contact line of the tread as the coordinate origin, the measurement data is preprocessed, and then the equivalent taper of the tread is calculated according to the Kingel formula,

In the formula, λ is the wavelength of the track of the wheelset; e is the distance between the left and right wheel-rail contact spots, that is, the span; R ₀ is the wheel rolling circle radius when the wheelset is in the center position; γ _e is the wheel The taper angle of the tread; tanγ _e is the equivalent taper of the wheel tread;

At the same time, use the converted data to calculate the QR value of the wheel rim, obtain the deviation between the measured contour and the standard contour, and obtain the wear amount of the wheel rim;

8) After the two directions are measured, the controller controls the laser displacement sensor to return to the zero position;

9) Analyze and process the acquired measurement signals, store the wheel position signals in the axial and radial directions, and output the measurement and analysis results.

Claims (3)

1. An on-machine measurement method for wheel and tread profiles of a railway vehicle is characterized by comprising the following steps of: the method comprises the following steps that a distributed measurement modular structure is adopted, parallel splicing is carried out according to a data interface rule, each distributed measurement module comprises two one-dimensional laser displacement sensors, the two one-dimensional laser displacement sensors axially move simultaneously through a motion shaft, measurement is achieved on a machine tool by means of Z-axis position signals or by means of adding auxiliary Z-axis, and measurement is achieved on a measuring machine by means of an X-axis directly;

the on-machine measuring method comprises the steps of measuring the radial profile of the wheel and the axial profile of the wheel tread;

the measurement of the wheel radial profile comprises the following steps:

the laser displacement sensor S1 and the laser displacement sensor S2 form a single wheel measuring unit, wherein the measuring position of the laser displacement sensor S1 is consistent with the vertical central line of the wheel to be measured, the linear distance between the laser displacement sensor S1 and the laser displacement sensor S2 is fixed to be L, the displacement measuring difference between the laser displacement sensor S1 and the laser displacement sensor S2 is d2-d1, and the radial radius of the obtained wheel is as follows:

when the wheel rotates, i measuring points are collected on one circle of the wheel, and the radial offset R of the wheel is obtained_iRotating the wheel by a set angle to obtain a function R related to the radial movement of the wheel_jThe expression is as follows:

R_j＝R_j(θ_j)

then to the wheel radial direction R_iOr R_jAnd performing noise elimination and smooth filtering processing, and outputting data to perform out-of-roundness and noise intensity evaluation analysis on the radial profile of the contact line of the wheel tread.

2. The on-machine measurement method of a rail vehicle wheel and tread profile of claim 1, wherein: the measurement of the wheel axial tread profile comprises the following steps:

two laser displacement sensors measure the tread profile of the wheel along a Z-direction guide rail, two position signals are required for measuring the axial tread profile of the wheel, and one position signal is derived from an output signal d of the laser displacement sensor S1_iWherein i is the number of sampling points; the other position signal is derived from the signal output by the Z-direction guide rail linear grating and is e_i，0≤e_iH is less than or equal to H; measuring point coordinate Q of tread and rim contour formed by two groups of position signals_i(e_i，h_i)；

The tread contact line is taken as the origin of coordinates, the measured data is preprocessed, then the equivalent taper of the tread is calculated according to the Kingel formula,

in the formula, lambda is the wavelength of the motion trail of the wheel set; e is the distance between the contact spots of the left wheel track and the right wheel track, namely the span; r₀The rolling circle radius of the wheel when the wheel set is in the centering position; gamma ray_eThe angle of the taper of the wheel tread is; tan gamma_eThe equivalent taper of the wheel tread;

and meanwhile, calculating a QR value of the wheel rim by using the converted data, obtaining the deviation of the measured profile and the standard profile, and obtaining the abrasion loss of the wheel rim.

3. The on-machine measurement method of a rail vehicle wheel and tread profile of claim 1, wherein: two laser displacement sensors of the dispersion measurement module are arranged on a sensor bracket, and the sensor bracket is axially connected with a Z-axis of the machine tool or independently forms a measurement shaft.

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