JP4657767B2 - Program, information storage medium and contact characteristic evaluation device - Google Patents

Description

  The present invention relates to a contact characteristic evaluation device for evaluating contact characteristics between a wheel and a rail.

When developing a bogie for a rail vehicle, when performing a bogie performance test on a vehicle test stand that uses rail-like rails and simulating the movement of the vehicle on the rail based on the performance test results There is. However, since the rail wheel is different from the actual rail, it is necessary to obtain information on the contact between the wheel and the rail wheel when performing the simulation. As a method for that purpose, the method of Non-Patent Document 1 is known.
Eisaku Sato, “Study on kinematics of independent wheel carriage with steering mechanism for railway vehicles, Chapter 2 Contact geometry of wheels and rail wheels”, Railway Technical Research Journal, Railway Technical Research Institute, April 2000, Special 37, p18-55

  When a railway vehicle runs on a rail, the tread surface of the wheel and the top surface of the rail wear, but this wear greatly affects the motion characteristics of the railway vehicle, so know the contact state between the wheel and the rail in the worn state. There is a need. Then, when it is going to evaluate the contact characteristic of the wheel and rail which were worn using the method currently disclosed by the nonpatent literature 1 mentioned above, the following problem will arise.

  That is, the above-described method is based on the premise that the shapes of the wheel and the rail wheel (rail) are formulated (functionalized). However, the actual worn wheels and rails have different shapes, and the shape data is given as analog data or digital data by a dedicated shape measuring device, for example. It is very difficult to formulate the shape. For this reason, it has been almost impossible to evaluate the contact characteristics of worn wheels and rails using the method described above.

  In view of the above circumstances, an object of the present invention is to enable evaluation of contact characteristics between wheels and rails using measured shape data.

In order to solve the above problem, the first invention is:
On the computer,
The tread shape data of the left and right wheels constituting the railway wheel set measured by a given shape measuring device , and the rail cross-sectional shape data measured by the shape measuring device are 0.2 mm in the wheel thickness direction. Data conversion means (for example, the data conversion unit 310 in FIG. 3; steps A1 and A5 in FIG. 13) for converting into discrete data at predetermined intervals less than
Based on the tread shape data and rail cross-sectional shape data of the left and right wheels after conversion by the data conversion means, and the left and right wheel spacing, the left and right wheels are changed to rails by changing the axial displacement of the wheel shaft and the roll angle of the wheel shaft. Contact point calculation means for calculating a contact point to be contacted (for example, contact characteristic calculation unit 330 in FIG. 3; steps A7 to A17 in FIG. 13);
Based on the contact point calculated by the contact point calculation means, contact for calculating a predetermined contact characteristic value between the wheel and the rail from the tread shape data of the left and right wheels after the conversion by the data conversion means and the rail cross-sectional shape data. Characteristic value calculating means (for example, contact characteristic calculating unit 330 in FIG. 3; steps A19 and A25 in FIG. 13),
For example, the contact characteristic evaluation program 410 in FIG.

In addition, the fourth invention is
The tread shape data of the left and right wheels constituting the railway wheel set measured by a given shape measuring device, and the rail cross-sectional shape data measured by the shape measuring device are 0.2 mm in the wheel thickness direction. Data conversion means for converting into discrete data at predetermined intervals less than,
Based on the tread shape data and rail cross-sectional shape data of the left and right wheels after conversion by the data conversion means, and the left and right wheel spacing, the left and right wheels are changed to rails by changing the axial displacement of the wheel shaft and the roll angle of the wheel shaft. Contact point calculation means for calculating a contact point to be contacted;
Based on the contact point calculated by the contact point calculation means, contact for calculating a predetermined contact characteristic value between the wheel and the rail from the tread shape data of the left and right wheels after the conversion by the data conversion means and the rail cross-sectional shape data. Characteristic value calculating means;
Is a contact characteristic evaluation apparatus (for example, the contact characteristic evaluation apparatus 20 of FIGS. 1 and 3).

According to the first or fourth invention, the tread surface shape data and the rail cross-sectional shape data of the left and right wheels constituting the railway wheel shaft are discrete data at predetermined intervals of less than 0.2 mm in the wheel thickness direction. Based on the tread shape data and the rail cross-sectional shape data of the left and right wheels after the conversion, contact points where the left and right wheels are in contact with the rails are calculated, and contact characteristic values between the wheels and the rails are calculated. Therefore, by converting the wheel tread shape data and the rail cross-sectional shape data by the shape measuring device into discrete data at a predetermined interval of less than 0.2 mm, the wheel that substantially matches the actual measurement value from the unformulated measurement data. The contact characteristic value between the rail and the rail can be calculated.

The second invention is the program of the first invention, wherein
The contact characteristic value calculating means calculates at least one contact characteristic value among a contact angle, a wheel radius and an equivalent tread surface gradient at the contact point;
The computer is made to function as described above.

  According to the second aspect of the present invention, at least one of the contact angle at the contact point, the wheel radius, and the equivalent tread surface gradient is calculated as the contact characteristic value.

  A third invention is a computer-readable information storage medium (for example, the storage unit 400 in FIG. 3) storing the program of the first or second invention.

  Here, the “information storage medium” is a storage medium such as a hard disk, an MO, a CD-ROM, a DVD, a memory card, and an IC memory, which can read stored information. Therefore, according to the third aspect of the invention, it is possible to obtain the same effect as the first or second aspect by causing the computer to read the information stored in the information storage medium and executing the arithmetic processing. it can.

  According to the present invention, the contact characteristic value between the wheel and the rail (specifically, the contact angle at the contact point) that substantially matches the actual measurement value from the non-formulated wheel and rail shape data that is the measurement data. , At least one of the wheel radius and the equivalent tread surface gradient) can be calculated.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[overall structure]
FIG. 1 is an overall configuration diagram of the present embodiment. As shown in the figure, the present embodiment includes a shape measuring device 10 and a contact characteristic evaluation device 20, and both devices are connected by a predetermined cable K. Here, the cable K is a communication path through which data can be exchanged, such as a cable for parallel connection or a cable for USB (Universal Serial Bus) connection.

  The shape measuring apparatus 10 measures the tread shape (cross-sectional shape in the thickness direction) of the wheel W of the railway vehicle that is the target object and the cross-sectional shape of the rail S. The measurement data is output as two-dimensional analog data. In the figure, the shape of both the wheel W and the rail S is measured by one shape measuring device 10, but it may be measured by the respective shape measuring devices for wheels and rails. Of course.

  The contact characteristic evaluation device 20 is configured by a PC (Personal Computer) or the like, and evaluates the contact characteristic between the wheel W and the rail S based on the measurement shape data of the wheel W and the rail S measured by the shape measurement device 10. . Specifically, the measured shape data of the wheel W and the rail S by the shape measuring device 10 which is analog data is converted into digital data (discrete data), and the wheel W and the rail S are converted based on the converted shape data. The contact characteristic value is calculated.

  FIG. 2A shows an example of measured shape data of the wheel W by the shape measuring device 10. However, the X direction is the wheel thickness direction, and the Y direction is the height direction. When converting measurement shape data, which is analog data, into digital data, data sampling is required, but the data interval of the sampled digital data after conversion is the accuracy of contact characteristic values and the like calculated later. Sampling is important because it greatly affects

  Specifically, for the same wheel, when the flange angle value (calculated value) calculated based on the measured shape data is compared with the actually measured flange angle value (actual value), the wheel thickness direction When the data interval is less than 0.2 [mm], the calculated value and the actually measured value almost coincided, but when the data interval becomes 0.2 [mm] or more, the calculated value and the actually measured value become large. I found it different. Although the flange angle has been described here, the same applies to the angle (contact angle) at the contact point between the wheel and the rail, which is one of the contact characteristics described later.

  For this reason, in the present embodiment, as shown in FIG. 2B, the measured shape data obtained by the shape measuring device 10 is such that the data interval in the X direction, which is the wheel thickness direction, is less than 0.2 [mm]. Convert to digital data at intervals. Then, the contact characteristics are evaluated using the equidistant data after the conversion. FIG. 7B shows a case where the data interval is converted into equidistant data of 0.15 [mm] for a part of the measured shape data of the wheel W shown in FIG.

  The same applies to the case where the measurement data obtained by the shape measuring apparatus 10 is given as digital data. That is, when the data interval in the X direction of the digital data is 0.2 [mm] or more, the contact characteristic evaluation device 20 performs a predetermined interpolation process on the data to set the data interval to 0.2 [ mm], and the contact characteristics between the wheel and the rail are evaluated on the basis of the converted equal interval data.

[Contact characteristic evaluation equipment]
FIG. 3 is a block configuration diagram of the contact characteristic evaluation device 20 of the present embodiment. According to the figure, the contact characteristic evaluation device 20 includes a communication unit 100, an input unit 200, a processing unit 300, a storage unit 400, and an output unit 500.

  The communication unit 100 performs data communication with an external device such as the shape measuring device 10 via the cable K. In particular, in this embodiment, the tread shape data of the left and right wheels and the cross-sectional shape data of the rails constituting one wheel shaft are fetched from the shape measuring device 10. The captured tread shape data of the left and right wheels is stored in the storage unit 400 as measured wheel shape data 421, and the cross-sectional shape data of the rail is stored as measured rail shape data 422, respectively. The communication unit 100 is realized by an interface board for external connection.

  The input unit 200 receives a user (user) operation input to the contact characteristic evaluation device 20 and outputs operation data to the processing unit 300. The input unit 200 is realized by, for example, a keyboard, a mouse, a button switch, a touch panel, various sensors, a microphone, and the like.

  The processing unit 300 performs overall control of the contact characteristic evaluation device 20. The processing unit 300 is realized by an arithmetic device such as a CPU or a storage device such as an IC memory. The processing unit 300 includes a data conversion unit 310, a wheel characteristic calculation unit 320, and a contact characteristic calculation unit 330, and evaluates the contact characteristics between the wheels and the rails according to the program and data read from the storage unit 400. The contact characteristic evaluation process is executed.

  The data conversion unit 310 converts the measurement wheel shape data 421 into discrete value data in which the data interval in the X direction is a predetermined interval (specifically, less than 0.2 [mm]). The converted data is stored in the storage unit 400 as equidistant wheel shape data 423. Similarly, the measurement rail shape data 422 is converted into discrete value data in which the data interval in the X direction is a predetermined interval (specifically, less than 0.2 [mm]). The converted data is stored in the storage unit 400 as equally spaced rail shape data 424.

The wheel characteristic calculation unit 320 calculates the flange angle, the flange thickness, and the wear amount as the wheel characteristics based on the equidistant wheel shape data 423. Specifically, as shown in FIG. 4, the position of the back surface of the wheel is x = 0, and the position in the Y direction of x = 65 [mm] is y = 0. The flange angle is obtained, for example, by calculating an approximate straight line of the tread between two points at positions y = −12 [mm] and y = −18 [ mm ] by the least square method. And Specifically, the data between y = −12 and −18 is interpolated into equally spaced data in 0.1 [mm] increments in the Y direction, and based on the obtained coordinate data of each point, the minimum two By using the multiplication method, an approximate straight line of the tread surface of y = -12 to -18 [mm] is obtained, and the angle of the approximate straight line is set as the flange angle. The flange thickness is an x value at y = −10 [mm]. The amount of wear is the difference between the y value at x = 65 [mm] and the y value at x = 65 [mm] in the value (standard value) of a new wheel indicated by the alternate long and short dash line in FIG. The wheel characteristic calculation unit 320 calculates these wheel characteristics (flange angle, flange thickness, and wear amount) for each of the left and right wheels. Each calculated characteristic value is stored in the storage unit 400 as wheel characteristic data 425.

The contact characteristic calculation unit 330 calculates the values of the contact angle, the contact radius, and the equivalent tread surface gradient as the contact characteristics between the wheels and the rails based on the equidistant wheel shape data 423 and the equidistant rail shape data 424. Specifically, based on the equally spaced wheel shape data 423 and equally spaced rails shape data 424, first, placed in each of the left and right wheels W _L, the right and left wheels interval wheelsets defined the W _R, left and right rails S _L and S _R are also arranged at specified intervals. Then, placing each of the wheels _W L, a _{W R} lateral rails _S L, the neutral position on the _{S R.} Then, the left and right wheels _W L, respectively _{W R,} a predetermined distance (e.g., 10 [mm]) is moved upward. FIG. 5 is a diagram illustrating an arrangement example of the wheel W and the rail S at this time, in which the X direction is a direction along the wheel axis (the thickness direction of the wheel W), and the Y direction is the height direction.

Then, by moving by a displacement X _w along the wheel axis in the axial direction, the left and right wheels W _L, W and _R, respectively are moved along the X direction, each of the left and right wheels when moving only the displacement X _w A point (contact point) at which the distances in the Y direction between W _L and W _R and the rails S _L and S _R become equal is calculated. If the wheel _W L, _{W R} tread and rail _S L, top surface of the _{S R} is worn, left and right wheels _W L, _{W R} the rail _S L, and _{S R,} wheel axis with respect to the horizontal plane Touch in a tilted state. For this reason, the wheel shaft is appropriately rolled (rotated). That is, the left and right wheels W _L, while maintaining the relative positional relationship of the W _R, the left and right wheels W _L, about the center point between W _R is rotated clockwise or counterclockwise direction. Thus, left and right wheels _W L, _{W R} the rail _S L, to calculate the point of contact with _{S R.}

Specifically, as shown in FIG. 6, to rotate the wheel axis by the roll angle phi _w. Then, the left and right wheels _W L, the _{W R} each rail _S L, to calculate the distance _H L, _{H R} between _{S R.} The distance H between the wheels and the rail is given as the minimum value of the height difference between the tread surface of the wheel W and the top surface of the rail S, as shown in FIG.

Subsequently, a difference F between the calculated distances H _R and H _L is obtained. Then, the value of the F is, for example, if 1/10000 [mm] or less, each of the left and right wheels _W L, _{W R} the rail _S L, the distance between the _{S R} equal, i.e. rolls at this time determining at the corner phi _w, left and right wheels _W L, _{W R} the rail _S L, and is the _{S R} may contact.

On the other hand, if the distance _H L, the value of the difference F in _{H R} is greater than 1/10000 [mm], left and right wheels _W L, _{W R} the rail _S L, unequal distances between the _{S R,} i.e. It is determined that contact cannot be made. If it is determined that not be contacted, the roll angle phi _w is changed by the bisection method or the Newton's method, again, left and right wheels W _L, W _R the rail S _L, the distance H _L between the S _R, H _R is determined and it is determined whether or not contact is possible. That is, left and right wheels _W L, _{W R} the rail _S L, the distance _H L between the _{S R,} until _{H R} matches, changing the roll angle phi _w. Note this time, the roll angle phi _w is, -φ _wm ~ + φ _wm, I vary in the range.

Left and right wheels _W L, _{W R} the rail _S L, when it is determined that the and _{S R} may contact, the wheels _W L which defines a rail wheel distance H in this case, the tread of _{W R y} wL, y The position of _{wR is} the position of the contact point with the rails S _L and S _R. Then, as shown in FIG. 8, the left and right wheels W _L, the W _R each of which calculates the value of the wheel radius and the contact angle at the contact point. The contact angle is given as the angle of the tangent at the contact point.

Contact characteristic calculation unit 330, a displacement _{X w,} varied in a range of -X _wm ~ _{+ X} wm at a predetermined displacement width [Delta] X _w increments, for each displacement _{X w,} as described above, the position of the contact point, the contact Calculate radius and contact angle.

Position of the calculated contact point for each displacement X _w is stored in the storage unit 400 as the contact data 426. In FIG. 9, an example of the contact state of the wheel W and the rail S based on the contact state data 426 is shown. In the figure, the arrangement position of the rail S is fixed, and the displacement X _w = 0, 5, 10, 15 [mm], and in each case, the wheel W is arranged so as to contact the rail S at the calculated contact point. This shows the state (contact state). FIG (a) shows the state of contact between the right wheel W _R and the right rail S _R, FIG. (B) shows the state of contact between the left wheel W _L and the left rail S _L.

Further, as the wheel radius wheel radius data 427a of each displacement _{X w,} the contact angle as the contact angle data 427b, stored in the respective storage unit 400. FIG. 10 shows an example of the wheel radius based on the wheel radius data 427a. In this figure, the horizontal axis is the displacement _Xw , and the vertical axis is the increment for the wheel radius of the new wheel (the wheel radius at the tread surface of 65 [mm] from the back surface; standard value). each X _w, and calculates the wheel radius of the increment for the new wheel, shows a graph obtained by plotting the incremental value.

FIG. 11 shows an example of a contact angle based on the contact angle data 427b. In the figure, the horizontal axis is the displacement _Xw , and the vertical axis is the contact angle [rad], and the graph obtained by plotting the value of the contact angle for each displacement _{Xw for} each of the left and right wheels W is shown. .

Further, the contact characteristic calculation unit 330, based on the contact radius and the contact angle of each calculated displacement X _w, to calculate a net rolling wavelength wheelset when the slip ratio as "0". And based on this calculation result, the equivalent tread surface gradient of the wheel W and the rail S is calculated. The equivalent tread slope is defined as a linear constant when the wheel and rail are in contact near the neutral point and each cross-sectional shape is a circular arc with a constant curvature and the tread slope is very small. It is the contact gradient between the approximated wheel rails.

The calculated equivalent tread gradient is stored in the storage unit 400 as equivalent tread gradient data 427c. FIG. 12 shows an example of the equivalent tread surface gradient data 427c. In the figure, the horizontal axis represents the displacement X _w, the vertical axis as the equivalent tread gradient shows a graph obtained by plotting the values of the equivalent tread gradient of each displacement X _w.

The storage unit 400 stores various programs and data for causing the processing unit 300 to control the contact characteristic evaluation device 20 in an integrated manner. Specifically, a contact characteristic evaluation program 410 is stored as a program, and as data, measurement wheel shape data 421, measurement rail shape data 422, equidistant wheel shape data 423, equidistant rail shape data 424, Wheel characteristic data 425, contact state data 426 , and contact characteristic data 427 are stored. The contact characteristic data 427 includes wheel radius data 427a, contact angle data 427b, and equivalent tread gradient data 427c. The storage unit 400 is realized by, for example, a hard disk, ROM, RAM, MO, or the like.

  The output unit 500 outputs the processing result of the processing unit 300, and is realized by a display device such as a CRT, LCD, or ELD, a sound output device such as a speaker, a printing device such as a printer, or the like.

[Process flow]
FIG. 13 is a flowchart for explaining the flow of the contact characteristic evaluation process in the contact characteristic evaluation apparatus 20. This process is realized by the processing unit 300 executing a process according to the contact characteristic evaluation program 410.

  According to the figure, first, the data conversion unit 310 performs a predetermined interpolation process on the measured wheel shape data 421 to obtain the equidistant wheel shape data 423 whose X-direction discrete width is less than 0.2 [mm]. Conversion is performed (step A1). Next, the wheel characteristic calculation unit 320 calculates the flange angle, the flange thickness, and the wear amount as the wheel characteristics based on the equidistant wheel shape data 423 (step A3). Further, the data conversion unit 310 performs a predetermined interpolation process on the measurement rail shape data 422, and converts the measurement rail shape data 422 into equally spaced rail shape data 424 having a discrete width in the X direction of less than 0.2 [mm] (step A5). .

Thereafter, the contact characteristic calculation unit 330 calculates the contact characteristic between the wheel and the rail. That is, on the basis of the equidistant wheel shape data 423 and the equidistant rail shape data 424, the left and right wheels are arranged at a neutral position on the rail, and a predetermined distance (for example, 10 [mm] from this position in the height direction (Y direction). ]) Is moved (step A7). Then, set the displacement X _w in a direction along the wheel axis (step A9). Here, the displacement X _w, at the time of initial setting, set to the minimum value of the displacement X _w can take "-X _wm".

Then, set the roll angle phi _w, changes the positions of the left and right wheels according to the roll angle phi _w set (step A11). Here, the roll angle φ _w, at the time of initial setting, is set to "0" corresponds to a case that does not roll. Then, for each of the left and right wheels, to calculate the minimum value of the difference in the height direction of the rail distance between the wheel-rail H _L, as H _R (step A13), the calculated distance H _L, whether H _R equals Judging. Specifically, calculates the difference F between the distance _{H L} and _{H R,} the magnitude of the value of the difference F is, for example, 1/10000 if it is [mm] or less, and the distance _{H L} and _{H R} Judge that they are equal.

As a result, in the case where the distance _{H L} and _{H R} is determined not equal (step A15: NO), the process returns to step A11, to reset the roll angle phi _w (step A11).

On the other hand, the distance when it is determined that H _L and H and _R are equal (step A15: YES), the contact characteristic calculating unit 330, for each of the left and right wheels, the position of the tread surface determining the distance H to the contact point ( Step A17). Then, for each of the left and right wheels, the wheel radius and the contact angle at this contact point are calculated (step A19).

Then, the current value of the displacement X _w is based on whether or not the maximum value "+ X _wm" or more, it is determined whether the processing has been completed for all of the displacement X _w. As a result of the determination, if not completed (step A21: NO), the process returns to step A9, and the displacement _Xw is reset (step A9). At this time, the displacement X _w is set to a value obtained by adding the value of the current displacement X _w a predetermined displacement width [Delta] X _w.

On the other hand, if completed for all the displacement X _w (step A21: YES), the contact characteristic calculation unit 330, based on the contact properties between the calculated wheel and rail, calculates a rolling wave wheel sets (step A23) Based on the calculated value, the equivalent tread surface gradient is calculated (step A25 ).
When the above process is performed, the contact characteristic evaluation process ends.

[Action / Effect]
As described above, according to the present embodiment, the contact characteristic evaluation device 20 uses the tread surface shape data of the wheel W measured by the shape measurement device 10 as digital data with a data interval in the wheel thickness direction of less than 0.2 [mm]. The contact characteristic value between the wheel W and the rail S is calculated using the converted shape data and the cross-sectional shape data of the rail S measured by the shape measuring device 10. Specifically, the contact point between the wheel W and the rail is calculated by changing the axial displacement Xw of the wheel shaft and the roll angle φw of the wheel shaft, and the wheel radius and the contact angle at this contact point are calculated as contact characteristic values. And an equivalent tread gradient is calculated.

  That is, the contact characteristic values of the wheel W and the rail S that are almost identical to the actual measurement values (specifically, the contact angle at the contact point, the wheel radius, and the Equivalent tread slope) can be calculated.

[Modification]
It should be noted that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention. For example, in the above-described embodiment, the entire measurement wheel shape data 421 that is measurement shape data of the left and right wheels by the shape measurement device 10 is converted into discrete value data in which the data interval in the X direction is less than 0.2 [mm]. However, it is also possible to convert only the portion of data that has a large influence on the calculation of wheel characteristics and contact characteristics into discrete value data in which the data interval in the X direction is less than 0.2 [mm]. Specifically, the data interval in the X direction is a predetermined position (for example, y = 70 [mm]) exceeding the reference position (y = 65 [mm]) for calculating the wear amount from the back surface (x = 0) of the wheel. The data in the range up to is less than 0.2 [mm], and the data in other ranges (for example, x = 70 [mm] or more) is a relatively wide data interval of about 1.0 [mm], for example. It is also good.

1 is an overall configuration diagram of an embodiment. An example of data conversion about measurement wheel shape data. The block block diagram of a contact characteristic evaluation apparatus. Calculation example of flange angle, flange thickness and wear amount. Arrangement example of wheel and rail. Setting an example of the roll angle φ _w to be supplied to the wheel axis. Calculation example of distance between wheels and rails. Calculation example of wheel radius and contact angle. An example of the contact state of a wheel and a rail based on contact state data. An example of a wheel radius increment based on wheel radius data. An example of a contact angle based on contact angle data. An example of an equivalent tread gradient based on equivalent tread gradient data. The flowchart of a contact characteristic evaluation process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shape measuring device 20 Contact characteristic evaluation apparatus 100 Communication part 200 Input part 300 Processing part 310 Data conversion part 320 Wheel characteristic calculation part 330 Contact characteristic calculation part 400 Memory | storage part 410 Contact characteristic evaluation program 421 Measurement wheel shape data 422 Measurement rail shape data 423 equidistant wheel shape data 424 equidistant rail shape data 425 wheel characteristic data
426 Contact state data
427 contact characteristic data
427a wheel radius data
427b contact angle data
427c equivalent tread gradient data 500 Output section W (W _L , W _R ) Wheel (left and right)
_{S (S L,} S R) rails (left-right)

Claims (4)

On the computer,
The tread shape data of the left and right wheels constituting the railway wheel set measured by a given shape measuring device, and the rail cross-sectional shape data measured by the shape measuring device are 0.2 mm in the wheel thickness direction. Data conversion means for converting into discrete data at predetermined intervals less than
Based on the tread shape data and rail cross-sectional shape data of the left and right wheels after conversion by the data conversion means, and the left and right wheel spacing, the left and right wheels are changed to rails by changing the axial displacement of the wheel shaft and the roll angle of the wheel shaft. Contact point calculation means for calculating a contact point to be contacted;
Based on the contact point calculated by the contact point calculation means, contact for calculating a predetermined contact characteristic value between the wheel and the rail from the tread shape data of the left and right wheels after the conversion by the data conversion means and the rail cross-sectional shape data. Characteristic value calculation means,
Program to function as. The contact characteristic value calculating means calculates at least one contact characteristic value among a contact angle, a wheel radius and an equivalent tread surface gradient at the contact point;
The program according to claim 1 for causing said computer to function.   A computer-readable information storage medium storing the program according to claim 1. The tread shape data of the left and right wheels constituting the railway wheel set measured by a given shape measuring device, and the rail cross-sectional shape data measured by the shape measuring device are 0.2 mm in the wheel thickness direction. Data conversion means for converting into discrete data at predetermined intervals less than,
Based on the tread shape data and rail cross-sectional shape data of the left and right wheels after conversion by the data conversion means, and the left and right wheel spacing, the left and right wheels are changed to rails by changing the axial displacement of the wheel shaft and the roll angle of the wheel shaft. Contact point calculation means for calculating a contact point to be contacted;
Based on the contact point calculated by the contact point calculation means, contact for calculating a predetermined contact characteristic value between the wheel and the rail from the tread shape data of the left and right wheels after the conversion by the data conversion means and the rail cross-sectional shape data. Characteristic value calculating means;
A contact characteristic evaluation apparatus comprising:

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