JP6663267B2 - Method and apparatus for measuring longitudinal creep force between wheel and rail of railway vehicle - Google Patents

Description

  The present invention relates to a method for measuring a longitudinal load in a vehicle traveling direction, that is, a longitudinal creep force, of a load acting on a contact portion between a wheel and a rail of a railway vehicle, and an apparatus for implementing the measuring method. .

  In the case of a bogie equipped with an integral axle, the longitudinal creep force acting on the contact point between the rear axle wheel and the rail when passing through a curved section generates a force that rotates the bogie in the yaw direction. And acts in a direction to increase the lateral pressure on the outer side of the leading shaft (Non-Patent Document 1).

  When the lateral pressure increases, the vehicle tends to derail when passing through a curved section. Therefore, measuring the vertical creep force among the loads acting on the contact portions between the wheels and the rails of the railway vehicle is very useful for improving the curve passing performance of the railway vehicle.

  In addition, when the wheel diameter wears and the difference in wheel diameter cannot be obtained when passing through the curve, the vertical creep force changes. Therefore, by measuring the longitudinal creep force, it is also possible to evaluate the state of wear of the wheels (Non-Patent Document 2).

  Further, in the steering bogie, when the steering is properly performed, the applied vertical creep force is small, but when the steering is not properly performed, the applied vertical creep force is large. Therefore, the abnormality of the steering device in the steering bogie can be detected by measuring the vertical creep force (Non-Patent Document 3).

  Also, in the case of an ordinary bogie that does not perform steering, for example, if the support device in the front-rear direction of the axle box breaks and an abnormality occurs, the longitudinal creep force greatly changes even under the same running conditions and running speed. Therefore, even in the case of an ordinary bogie, an abnormality can be detected by measuring the vertical creep force. Especially in the straight section, when the front and rear support of the axle box is not normal, the longitudinal creep force that acts is greater than when the front and rear support of the axle box is normal, so measure the vertical creep force from the ground side in the straight section. It is effective to do.

  As a method of measuring a longitudinal creep force acting on a contact portion between a wheel and a rail of a railway vehicle, a method of measuring from a strain generated on a wheel and a monolink force on a bogie having a monolink type axle box support device is disclosed. (For example, Patent Document 1 and Non-Patent Document 4).

  As disclosed in Patent Literature 1 and Non-Patent Literature 4, measurement of longitudinal creep force acting on a contact portion between a wheel and a rail of a railway vehicle has been conventionally performed from the upper side of the vehicle. Therefore, even if the lubrication condition between the rail and the wheel is changed from the ground side, the change in longitudinal creep force must be checked on the upper side of the vehicle, and the timely check whether the changed lubrication condition is optimal is performed. I couldn't do that. Further, when trying to detect the condition of wheel wear or abnormality of a monolink that supports the axle box in the front-rear direction from the vertical creep force, it is necessary to measure the load of the monolink for each vehicle.

Japanese Patent No. 5034666

"Basic Study on Dynamic Performance of Asymmetrical Dolly with Independent Wheel on Rear Shaft", Technical Magazine Sumitomo Metal, Vol.50 No.3 (1998), p4-8 "Effects of Wheel and Rail Wear Shape on Sharp Curve Performance", Proc. 19th Symposium on Railway Technology, 2012.12, p677-680 "Development of a new steering bogie for subway", Proc. Of the 17th Symposium on Railway Technology, 2010.12, p191-194 "Friction adjustment material injection control system by wheel tangential force monitoring (feedback control using load acting on axle box support device)", Research & Development, Japan Railway Rolling Stock Machine Technology Association, 2010.6, p10-14

  The problem to be solved by the present invention is that a technique for measuring the longitudinal creep force acting on a contact portion between a wheel of a railway vehicle and a rail from the ground side has not been proposed.

  An object of the present invention is to make it possible to measure the longitudinal creep force acting on a contact portion between a wheel and a rail of a railway vehicle from the ground side.

  When a wheel comes into contact with a rail during traveling of a railway vehicle, there are four types of stress generated on the rail: stress due to wheel load, stress due to lateral pressure, stress due to longitudinal creep force, and stress due to spin.

  Among the above-mentioned stresses, the influence of the stress due to the spin is originally small and can be ignored. When there is an influence of the stress due to the lateral pressure, for example, the strain gauges 4a and 4b are attached at the positions shown in FIG. 8A, and the strain gauges 4a and 4b are connected as shown in FIG. 8B. By forming the Wheatstone bridge circuit B, it can be removed. That is, by applying the strain gauges 4a and 4b to the front and back surfaces of the web 1a of the rail 1 at positions that are line-symmetric with respect to the width direction center line CL in the cross section of the rail 1, the influence of the stress due to the lateral pressure is reduced. Can be removed. Note that R in FIG. 8 is a dummy resistor.

  Therefore, if the stress caused by the wheel load and the stress caused by the vertical creep force can be separated from the stress generated on the rail when the wheel comes into contact with the rail, the longitudinal creep force can be measured from the stress generated on the rail. it can.

The present invention has been made based on the above idea.
That is, according to the present invention, a wheel load is applied to an intermediate position between adjacent sleepers that support a rail, and a main stress generated in the rail at two places at equal intervals before and after the intermediate position from the intermediate position to the rail laying direction. The stress (principal stress) in the direction is measured.

  Since the stress field generated by the loaded wheel load is symmetrical in the front and rear directions of the rail laying direction, the main stress of the rail due to the wheel load is the same. Therefore, the main stress generated on the rail due to the wheel load is measured at two measurement positions before and after the rail laying direction, and the main stress due to the wheel load is removed by taking the difference between the measured main stresses. The stress difference is due to the longitudinal creep force.

  Therefore, the difference between the main stress measured at the two measurement positions when the wheel load was applied to the middle between the adjacent sleepers (hereinafter referred to as the main stress difference before and after) and the longitudinal creep force were applied. If the relationship between the main stress difference before and after the case is determined in advance by a theoretical analysis or a finite element analysis (hereinafter, referred to as FEM analysis), the vertical stress is calculated from the relationship determined in advance and the main stress due to the measured longitudinal creep force. Creep force can be obtained. This is the longitudinal creep force measuring method of the present invention.

  In the present invention, if the measurement of the main stress is performed on the front and back surfaces of the rail web which is line-symmetric with respect to the center line in the width direction of the cross section of the rail, by forming a bridge circuit connecting these measuring elements. In addition, the influence of stress due to lateral pressure can be eliminated.

The method of the present invention,
A measuring element for measuring the main stress of the rail, which is affixed symmetrically in the longitudinal direction of the laying direction at two places at equal intervals in the longitudinal direction of the rail from an intermediate position between the adjacent ties for supporting the rail, and
Means for detecting that the wheels of the railway vehicle pass through the intermediate position,
When the wheel passes through the intermediate position, by taking the difference from the average of the main stress at two measurement positions before and after, measured by the tracing stylus, the main stress due to the wheel load, which is the average of the main stress And the principal stress due to the longitudinal creep force, which is the difference between the principal stresses, and the principal stress due to the separated longitudinal creep force, the difference before and after the principal stress when the previously determined wheel load is equally applied. And an arithmetic unit that obtains a vertical creep force by converting from a relationship between a front-back difference of a main stress when a vertical creep force is applied,
This is carried out by using the vertical creep force measuring device between the wheel and the rail of the railway vehicle of the present invention provided with the above.

  In the present invention, when the wheel passes through the intermediate position between the adjacent sleepers, the main stress of the rail is measured instead of the shear strain such as the conventional wheel load measurement and the lateral pressure measurement, because the wheel load and the longitudinal load are measured. The creep force is perpendicular to the direction of action. In this case, if the measured stress is the principal stress due to the wheel load, the stress due to the longitudinal creep force is also the principal stress, and it does not include the shear stress component that is difficult to measure. This is because the processing and the difference calculation processing can be performed as they are.

  However, when measuring the main stress of the rail, only the intermediate position can be separated into the proportional stress of the wheel load if the average is taken and the proportional stress of the longitudinal creep force if the difference is taken.

  In the present invention, the detection that the wheel of the railway vehicle passes through the intermediate position between the adjacent sleepers is performed, for example, by attaching a uniaxial strain gauge to the bottom of the rail at the intermediate position in the laying direction of the rail and passing the wheel. The determination may be made based on the peak value of the stress at the time, or the passing wheel may be detected by the laser displacement meter.

  To obtain the actual value of the principal stress due to the longitudinal creep force at the measurement site, it is necessary to apply a shear load to the contact position between the wheel and the rail for calibration. It is difficult to load.

  In the present invention, the relationship between the main stress generated in the rail due to the wheel load and the main stress generated in the rail due to the longitudinal creep force is calculated in advance by theoretical analysis or FEM analysis. Thus, by calibrating the wheel weight at the site, a calibration value of the longitudinal creep force can be obtained at the site based on the relationship calculated in advance.

  For example, by using a known wheel load calibration method described on pages 102 to 112 of “Conventional Railway Operation Speed Improvement Test Manual / Explanation (edited by the Railway Technical Research Institute, supervised by the Ministry of Transport), Calibration of the longitudinal creep force acting on the contact portion can be performed, and the longitudinal creep force can be measured.

  In the present invention, in the measurement of the longitudinal creep force acting on the contact portion between the wheel and the rail, by applying a load in the wheel load direction to the rail, a calibration result of the longitudinal creep force can be obtained. It becomes possible to measure the longitudinal creep force acting on the contact portion of the rail.

  Therefore, when applying oil or lubricant to the rail tread from the ground side, the vertical creep force can be measured on the ground side, and the measurement results are fed back in a timely manner to apply the oil or lubricant. Can be optimally controlled. In addition, the state of the monolink that supports the axle box in the front-rear direction in all vehicles passing over the point where the vertical creep force is measured can be monitored from the ground side.

  In addition, by using it integrally with a vehicle identification device such as an RFID (Radio Frequency Identification) tag, it is possible to more efficiently monitor the tread state of all vehicles traveling on the rails and the front and rear support of the axle box. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the 1st example of the longitudinal creep force measuring method and its apparatus of this invention, (a) is the figure seen from the side of the rail, (b) is the figure seen from diagonally upward. (A) is a diagram showing a Wheatstone bridge circuit when measuring longitudinal creep force in the present invention, and (b) is a diagram when measuring a vertical load on a rail applied for calibration of longitudinal creep force in the present invention. FIG. 3 is a diagram showing an example of a Wheatstone bridge circuit. It is the figure which showed an example of the maximum principal stress by the wheel load in the position 0.2m ahead of the rail installation direction from the intermediate position between adjacent sleepers. It is the figure which showed an example of the maximum principal stress by the wheel load in the position 0.2m behind the rail laying direction from the intermediate position between adjacent sleepers. It is the figure which showed an example of the maximum principal stress by the longitudinal creep force in the position 0.2m ahead of the rail installation direction from the intermediate position between adjacent sleepers. It is the figure which showed an example of the maximum principal stress by the longitudinal creep force in the position 0.2m behind in the rail installation direction from the intermediate position between adjacent sleepers. (A), (b) is the figure seen from the side of the rail explaining other examples of the detection means of the detection of having passed the wheel in the intermediate position between the adjacent sleepers in this invention. (A) is a diagram showing an example of a position where a strain gauge is attached to remove the influence of stress due to lateral pressure generated on a rail, and (b) is an example of a Wheatstone bridge circuit connecting the strain gauge of (a). FIG.

  An object of the present invention is to make it possible to measure a vertical creep force acting on a contact portion between a wheel and a rail of a railway vehicle from a ground side. The purpose is to measure the main stress generated on the rail by a measuring element installed on the ground side, and convert it from the relationship between the wheel load and the main stress difference before and after due to the longitudinal creep force, which is calculated in advance, and calculate the longitudinal creep force. It was realized by obtaining.

  Hereinafter, the process from the idea of the present invention to the solution of the problem will be described, and then the first embodiment of the present invention will be described with reference to FIGS.

  Techniques for measuring the axial force generated on a long rail have conventionally existed. Since this axial force is not generated by the passage of a railway vehicle, the measurement is performed from the ground side.

  On the other hand, the stress generated in the rail when a load is applied to the contact position between the wheel and the rail due to the passage of the railroad vehicle can also be measured from the ground side, for example, by attaching a strain gauge to the rail.

  However, when a strain gauge is attached to the rail and the load applied to the contact point between the wheel and the rail from the ground side is measured, an accurate load must be applied at the site using an actual hydraulic jack, etc. I don't know the value.

  The wheel load (load) acting on the rail in the vertical direction is determined by applying a load at the site, as described on page 105 of the "Manual Explanation of Conventional Railroad Speed Improvement Test" described earlier. Can be calibrated. On the other hand, since the action direction of the vertical creep force is in the shear direction with respect to the rail, a load cannot be applied using a hydraulic jack or the like, and calibration cannot be performed on site.

  However, the relationship between the main stress generated in the rail due to the wheel load and the main stress generated in the rail due to the longitudinal creep force can be obtained by theoretical analysis or FEM analysis. Therefore, if the above relationship is determined in advance by theoretical analysis or FEM analysis, the main stress generated in the rail due to the longitudinal creep force can be calculated on site using a hydraulic jack or the like from the vertical direction of the rail, as in the calibration of the wheel load. It can be loaded and calibrated.

The present invention has been made based on the above ideas of the inventors.
For example, as shown in FIG. 1, the sleeper 2 supporting the rail 1 is equally spaced, for example, 0.2 m away from an intermediate position Pc between the adjacent sleepers 2 toward the front and rear in the laying direction of the rail 1. At the positions P1 and P2, the main stress of the rail when the wheel 3 of the railway vehicle passes the intermediate position Pc is measured.

  The measurement of the main stress at the positions P1 and P2 is performed, for example, as shown in FIG. 1B, in a longitudinally symmetrical manner in the laying direction and in a center line in a width direction of the rail 1 when the rail 1 is cross-sectioned. This is performed by attaching uniaxial strain gauges 4A1, 4B1 and 4A2, 4B2 to the front and back surfaces of the web 1a that is line-symmetric with respect to CL.

  FIG. 1 shows an example in which the strain gauges 4A1, 4B1 and 4A2, 4B2 are attached in the direction of the main stress during the load action to measure the main stress generated in the rail 1. At this time, the strain gauges 4A1, 4B1 and 4A2, 4B2 are respectively stuck obliquely upward in the direction of the intermediate position Pc, for example, at 45 °. This is because, in actual work, workability is good in the case of a 45 ° obliquely upward direction.

  In FIG. 1, the strain gauges 4A1, 4B1 and 4A2, 4B2 are attached near the center of the rail 1 in the height direction of the web 1a. This is because the bending stress acting on the rail 1 due to the vertical load is small, and the influence of noise due to the bending stress can be reduced.

  FIG. 1 shows an example in which the laser displacement meter 5 detects that the wheel 3 of the railway vehicle has passed the intermediate position Pc. When the passage of the wheel 3 is detected, the main stresses of the rails at the respective positions P1 and P2 are measured by the strain gauges 4A1 and 4B1 and 4A2 and 4B2. I do.

  The main stress input to the calculator 6 is a difference between the main stress measured at the position P1 and the main stress measured at the position P2, and can be obtained by assembling a Wheatstone bridge circuit B shown in FIG. By taking the difference between the main stresses measured at the position P1 and the position P2 in this way, the main stress due to the wheel load is removed, and the remaining main stress difference is due to the longitudinal creep force.

  The reason is that, at the positions P1 and P2 which are equally spaced apart from each other before and after the intermediate position Pc in the direction in which the rail 1 is laid, the wheel loads P when the wheels 3 of the railway vehicle pass through the intermediate position Pc are the same. On the other hand, the rail strain due to the vertical creep force T has a different direction, that is, a different sign at the position P1 and the position P2.

  The computing unit 6 converts the principal stress due to the longitudinal creep force from the relationship between the principal stress generated in the rail due to the wheel load P and the principal stress generated in the rail due to the longitudinal creep force T, which is obtained in advance, and calculates the longitudinal stress. Find the creep force.

  The relationship between the main stress generated on the rail by the wheel load P and the main stress generated on the rail by the vertical creep force T can be calculated by theoretical analysis or FEM analysis.

For example, the angle on the rear side in the laying direction between the strain gauges 4A1 and 4B1 at the position P1 and the horizontal line is θ ₁ , and the wheel on the top surface of the rail 1 at the intermediate position Pc between the strain gauges 4A1 and 4B1 at the position P1 and the adjacent sleeper 2 The distance to the contact position with _No. 3 is r ₁ . The angle at the rear side in the laying direction between the strain gauges 4A2 and 4B2 at the position P2 and the horizontal line is θ ₂ , and the distance from the strain gauges 4A2 and 4B2 at the position P2 to the contact position is r ₂ . In this case, the expression of the stress field at the positions P1 and P2 can be expressed as follows.

(Principal stress due to wheel load P)
σr = (2P / π) × (sin θ / r) = ε _P · E
(Principal stress due to longitudinal creep force T)
σr = (2T / π) × (cos θ / r) = ε _Q · E

That is, at the position P1, the strain due to the wheel load P and the strain due to the longitudinal creep force T are as follows.
ε _1P = (2P / πE) × (sin θ ₁ / r ₁ ) = K ₁ · P · sin θ ₁
ε _1Q = (2T / πE) × (cos θ ₁ / r ₁ ) = K ₁ · Q · cos θ ₁
However, K ₁ = 2 / πr ₁ E

At the position P2, the strain due to the wheel load and the strain due to the vertical creep force are as follows.
ε _2P = (2P / πE) × (sin θ ₂ / r ₂ ) = K ₂ · P · sin θ ₂
ε _2Q = (2T / πE) × (cos θ ₂ / r ₂ ) = K ₂ · T · cos θ ₂
However, K ₂ = 2 / πr ₂ E

Therefore, the respective measured values (main stress) when the strain gauges are attached to the positions P1 and P2 can be expressed by the following equations.
ε ₁ = K ₁ · P · sin θ ₁ + K ₁ · T · cos θ ₁
ε ₂ = K ₂ · P · sin θ ₂ + K ₂ · T · cos θ ₂

When r ₁ = r ₂ = r, θ ₁ = θ, θ ₂ = π−θ in the equations for obtaining the measured values at the positions P1 and P2, the wheel load P and the vertical creep force T are obtained by the following equations. Can be.
P = (1 / K sin θ) × (ε ₁ + ε ₂ )
T = (1 / Kcosθ) × (ε ₁ −ε ₂ )

  Therefore, the relationship between the main stress due to the wheel load P and the main stress due to the longitudinal creep force T can be determined in advance by the above equation.

  The relationship between the wheel load P and the principal stress due to the longitudinal creep force T is obtained by not only converting the principal stress due to the longitudinal creep force into a longitudinal creep force, but also changing to a Wheatstone bridge circuit B shown in FIG. It is also possible to calibrate the wheel load on site to calibrate the longitudinal creep force on site.

  FIGS. 3 to 6 are diagrams showing the results of FEM analysis of the main stress generated in the rail when a wheel load of 30 kN is applied. The rail used for this FEM analysis was a 50 kgN rail, and the Young's modulus of the roadbed was 19600 MPa assuming a concrete directly connected roadbed, and the Young's modulus of the rail was 206 GPa.

  According to the FEM analysis performed under the above conditions, the main stress was in the direction of 45 ° at a point 90 mm in the front-rear direction from the load point, as shown in FIGS.

  Assuming that the ballast is a ballast ballast, the same FEM analysis was performed with a Young's modulus of 27.9 to 47.9 MPa, and the main stress was approximately 45 ° in the range of 85 to 120 mm in the longitudinal direction from the load point. Was.

  From the results of the FEM analysis, it is understood that the positions P1 and P2 are desirably set within a range of 85 to 120 mm before and after the intermediate position Pc in the rail laying direction.

  In addition, as shown in FIG. 1, as shown in FIG. 1, a strain gauge is attached in a 45 ° upward direction toward the intermediate position Pc in a longitudinally symmetric manner at the positions P1 and P2, and the following load is applied to the intermediate position Pc. It shows the main stress in the 45 ° direction when applied.

(Load applied)
・ 30kN wheel load ・ 10kN longitudinal creep force ・ A combined load of 30kN wheel load and 10kN longitudinal creep force

  From Table 1 above, when a combined load of a wheel load of 30 kN and a vertical creep force of 10 kN is applied, the average of the position P1 and the position P2 is −10.75 MPa, and the difference between the position P1 and the position P2 is 3.5 MPa. It is. It can be seen that these values correspond to the main stress when a wheel load of 30 kN is applied and when the longitudinal creep force of 10 kN is applied, respectively.

  The present invention is not limited to the above examples, and it goes without saying that the embodiments may be appropriately changed within the scope of the technical idea described in each claim.

  In the above embodiment, the principal stress is measured using a uniaxial strain gauge, but the principal stress may be measured using a biaxial strain gauge or a triaxial strain gauge. When a biaxial strain gauge or a triaxial strain gauge is employed, the main stress may be obtained from the measured output, or the positions of the strain gauges attached to the positions P1 and P2 may be adjusted so as to be oriented to the main stress. It may be used as a uniaxial strain gauge.

  Further, the detection that the wheel 3 of the railway vehicle has passed the intermediate position Pc is not limited to the laser displacement meter 5, and a strain gauge 4C is attached to the rail 1 at an intermediate position between the adjacent sleepers as shown in FIG. Alternatively, the passage of the wheel may be detected based on the peak value of the measured stress. In this case, even if the strain gauge 4C is attached in the height direction to the center of the rail 1 in the height direction of the web 1a as shown in FIG. 7A, as shown in FIG. 1 may be attached to the bottom surface of the rail 1 in the direction in which the rail 1 is laid.

  Further, in the above embodiment, the longitudinal creep force is obtained by measuring the principal stress, but the longitudinal creep force may be obtained from the principal strain.

  In the above embodiment, the main stress is measured using the strain gauge. However, if the main stress or the main strain can be measured, a measuring element other than the strain gauge, such as an optical fiber sensor or a surface acoustic wave sensor, may be used. May be used.

  Also, by measuring the vertical creep force during traveling on a curved section from the ground using the present invention, it is also possible to monitor the tread wear of the wheels of the vehicle traveling on the rail.

  In addition, by using the present invention to measure the longitudinal creep force during traveling in a straight section from the ground, it is also possible to monitor the front and rear instruction state of the axle box of the traveling vehicle.

DESCRIPTION OF SYMBOLS 1 Rail 2 Sleeper 3 Wheel 4A1, 4B1, 4A2, 4B2 Strain gauge 4C Strain gauge 5 Laser displacement meter 6 Computing device Pc Intermediate position P1 Position in front of laying direction P2 Position in rear of laying direction B Wheatstone bridge circuit P Wheel weight T Vertical creep Force CL rail center line in width direction

Claims (14)

The main stress or the main stress generated on the rail when the wheel of the railway vehicle passes through the intermediate position at two places at equal intervals before and after the intermediate position between the adjacent crossties supporting the rail at the front and rear in the laying direction of the rail. Measure the main strain,
The difference between the principal stress or principal strain at these two measured locations was determined in advance by theoretical analysis or finite element analysis, and the principal stress or principal strain generated by wheel load and the principal stress generated by longitudinal creep force were determined. A method for measuring longitudinal creep force between a wheel and a rail of a railway vehicle, wherein the method is converted into a longitudinal creep force based on a relationship between stress and principal strain.   The measurement of principal stress or principal strain at the two locations is performed at front and back positions of a rail web that is line-symmetric with respect to a center line in a width direction when the rail is cross-sectioned. 4. A method for measuring longitudinal creep force between a wheel of a railway vehicle and a rail according to the above.   By calibrating the wheel weight, the longitudinal creep force is calibrated based on the relation obtained in advance, between the wheel and the rail of the railway vehicle according to claim 1 or 2. Vertical creep force measurement method.   The wheel and rail of a railcar according to any one of claims 1 to 3, wherein the two positions are separated from the intermediate position by 85 to 120 mm before and after the rail laying direction. Vertical creep force measurement method.   The measurement of the main stress or the main strain is performed at a center in the height direction of the rail at the two positions, using a strain gauge attached in a 45 ° obliquely upward direction toward the top surface of the rail at the intermediate position. The method for measuring longitudinal creep force between a wheel and a rail of a railway vehicle according to claim 1.   The method according to claim 5, wherein the strain gauge is one of a single axis, a two axis, and a three axis.   The detection that the wheel of the railway vehicle has passed the intermediate position between the adjacent sleepers is performed by a laser displacement meter, and the vertical distance between the wheel of the railway vehicle and the rail according to any one of claims 1 to 6, wherein Creep force measurement method.   The detection that the wheel of the railway vehicle has passed through the intermediate position between the adjacent sleepers is detected using a strain gauge attached to the rail web in the height direction or the rail laying direction on the bottom surface of the rail at the intermediate position. The method for measuring the vertical creep force between a wheel and a rail of a railway vehicle according to any one of claims 1 to 6, wherein the measurement is performed at the peak value of the stress at the time of passing the wheel. Measurement of measuring the principal stress or principal strain of the rail, which is affixed symmetrically in the longitudinal direction of the rail at two places at equal intervals before and after the rail laying direction from the intermediate position between the adjacent ties supporting the rail. With the child,
Means for detecting that the wheels of the railway vehicle pass through the intermediate position,
When the wheel passes through the intermediate position, measured by the tracing stylus, by taking the difference between the average of the principal stress or principal strain at two measurement positions before and after, the average of the principal stress or principal strain The main stress or principal strain due to a certain wheel load and the principal stress or principal strain due to the longitudinal creep force, which is the difference between the principal stress or principal strain, are separated, and the principal stress or principal strain due to the separated longitudinal creep force is determined in advance. A principal stress or principal strain generated by the wheel load, and a computing unit that obtains a longitudinal creep force by converting from a relationship between the principal stress or principal strain generated by the longitudinal creep force,
A vertical creep force measuring device between a wheel of a railway vehicle and a rail, comprising:   The longitudinal creep force measurement between a wheel and a rail of a railway vehicle according to claim 9, wherein the two positions are separated from the intermediate position by 85 to 120 mm before and after the rail laying direction. apparatus.   The vertical creep force measuring device between a wheel and a rail of a railway vehicle according to claim 9, wherein the tracing stylus is any one of a single-axis, a two-axis, and a three-axis strain gauge.   The railcar according to claim 11, wherein the tracing stylus is affixed to the front and back positions of the rail web that is line-symmetric with respect to the center line in the width direction when the rail is cross-sectioned. A device for measuring vertical creep force between wheels and rails.   The said measuring element is stuck in the 45-degree diagonally upward direction which goes to the top face of the rail in the said intermediate position from the rail height center position in the said two positions. The vertical creep force measuring device between a wheel of a railway vehicle and a rail according to claim 1.   Means for detecting that the wheel of the railway vehicle has passed through an intermediate position between adjacent sleepers includes a laser displacement meter, a strain gauge attached to a rail web in the height direction at the intermediate position, and a bottom surface of the rail at the intermediate position. The vertical creep force measuring device between a wheel and a rail of a railway vehicle according to any one of claims 9 to 13, wherein the vertical creep force measuring device is any one of a strain gauge attached to a rail in a direction in which the rail is laid.

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