JP2017181061A - Measuring method and device for vertical creep force between wheel of railway vehicle and rail - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to measure vertical creep force working on a contact portion between a wheel of a railway vehicle and a rail from a ground side.SOLUTION: Strain gauges 4A1, 4B1, 4A2, and 4B2 are pasted symmetrically forth and aft in a laid direction of a rail 1 on front and back surfaces of a web 1a in two positions P1, P2 which are each equally separated in the front and aft in a laid direction of a rail from an intermediate position Pc between adjacent sleepers 2 in a central position in height direction of the rail 1. A main stress or a main strain is measured by strain gauges 4A1, 4B1, 4A2, and 4B2 when a wheel 3 of the railway vehicle passes an intermediate position Pc. A difference of the measured main stress or the main strain is converted based on a relationship between weight of the wheel and the vertical creep force previously obtained and then the vertical creep force is obtained.EFFECT: Measured result is capable of timely feedback.SELECTED DRAWING: Figure 1

Description

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

  In the case of a truck with an integrated wheel and wheel axle, the vertical creep force acting on the contact part between the rear wheel and the rail when passing through the curved section generates a force that rotates the carriage in the yaw direction. Thus, it acts in the direction of increasing the lateral pressure on the front shaft outer gauge side (Non-Patent Document 1).

  When the lateral pressure increases, derailment easily occurs when passing through the curved section. Therefore, it is very useful to measure the longitudinal creep force among loads acting on the contact portion between the wheel and rail of the railway vehicle in order to improve the curve passing performance of the railway vehicle.

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

  Further, in the steering cart, the vertical creep force that acts when steering is properly performed is small, but when the steering is not performed appropriately, the vertical creep force that acts is large. Therefore, the abnormality of the steering device in the steering cart can be detected by measuring the longitudinal creep force (Non-patent Document 3).

  Also, in the case of a normal carriage 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 vertical creep force changes greatly even if the running conditions and the running speed are the same. Therefore, even in the case of a normal carriage, an abnormality can be detected by measuring the longitudinal creep force. Especially in the straight section, when the longitudinal support of the axle box is not normal, the vertical creep force acting is larger than when the longitudinal support of the axle box is normal, so the longitudinal creep force is measured from the ground side in the straight section. It is effective to do.

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

  As disclosed in Patent Document 1 and Non-Patent Document 4, the measurement of the longitudinal creep force acting on the contact portion between the wheel of the railway vehicle and the rail has been conventionally performed from the upper side of the vehicle. Therefore, even when the lubrication condition between the rail and the wheel is changed from the ground side, the change in the longitudinal creep force must be confirmed on the vehicle upper side, and it is timely confirmed whether the changed lubrication condition is optimal. I couldn't. In addition, when attempting to detect the state of wheel wear and the abnormality of the monolink that supports the axle box in the longitudinal direction from the longitudinal creep force, it is necessary to measure the load of the monolink for each vehicle.

Japanese Patent No. 5033466

"Basic research on kinematic performance of asymmetric trucks with independent wheels on the rear axle", Technical Journal Sumitomo Metals, Vol.50 No.3 (1998), p4-8 "Effect of wheel and rail wear shape on sharp curve passing performance," Proceedings of the 19th Railway Technology Union Symposium, 2012.12, p677-680 "Development of a new submersible for a subway", Proceedings of the 17th Railway Technology Union Symposium, 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 Vehicle Machinery Technology Association, 2010.6, p10-14

  The problem to be solved by the present invention is that, conventionally, no technique has been proposed for measuring the longitudinal creep force acting on the contact portion between the wheel and rail of a railway vehicle from the ground side.

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

  When the wheel contacts the rail during traveling of the railway vehicle, there are four stresses 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 stresses, the influence of the stress due to the spin is originally small and can be ignored. Further, when there is an influence of stress due to the lateral pressure, for example, the strain gauges 4a and 4b are attached to the positions shown in FIG. 8A, and the strain gauges 4a and 4b are connected as shown in FIG. 8B. Therefore, it can be removed by assembling the Wheatstone bridge circuit B. That is, by applying the strain gauges 4a and 4b on the front and back surfaces of the web 1a of the rail 1 at positions that are line symmetric with respect to the center line CL in the width direction in the cross section of the rail 1, the influence of stress due to the lateral pressure is exerted. 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 longitudinal creep force can be separated from the stresses produced on the rail when the wheel contacts 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, the present invention loads the wheel load at an intermediate position between adjacent sleepers that support the rail, and the main stress generated in the rail at two locations that are equally spaced from the intermediate position in the rail installation direction. Measure the direction stress (principal stress).

  Since the field of stress generated by the loaded wheel load is symmetrical before and after the rail installation direction, the main stress of the rail by the wheel load is the same. Therefore, the main stress generated in 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 is applied in the middle between the adjacent sleepers (hereinafter referred to as the main stress difference between the front and rear) and the longitudinal creep force are applied. If the relationship between the main stress difference before and after the case is obtained in advance by theoretical analysis or finite element analysis (hereinafter referred to as FEM analysis), the longitudinal stress is calculated from the relationship obtained in advance and the principal 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 that is line-symmetric with respect to the center line in the width direction of the cross section of the rail, a bridge circuit in which these measuring elements are connected is assembled. The influence of stress due to lateral pressure can be removed.

The method of the present invention described above
A measuring element for measuring the main stress of the rail symmetrically in the longitudinal direction of the laying direction at two locations spaced equidistantly in the longitudinal direction of the rail from an intermediate position between adjacent sleepers that support the rail;
Means for detecting that a wheel of the railway vehicle passes through the intermediate position;
The main stress due to the wheel load, which is the average of the main stresses, is obtained by taking the difference from the average of the main stresses at the two measurement positions before and after the measurement by the probe when the wheel passes the intermediate position. And the main stress due to the longitudinal creep force, which is the difference between the principal stresses, and the main stress due to the separated longitudinal creep force is the difference between before and after the principal stress when the previously determined wheel load is equally applied. And an arithmetic unit that obtains the longitudinal creep force by converting from the relationship between the front and back differences of the main stress when the longitudinal creep force is applied,
It implements using the longitudinal creep force measuring apparatus between the wheel of the rail vehicle of this invention provided with rails, and a rail.

  In the present invention, when the wheel passes through an intermediate position between adjacent sleepers, the main stress of the rail is measured, not the shear strain as in the conventional wheel load measurement or lateral pressure measurement. 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 the shear stress component that is difficult to measure is not included. 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, it is only the intermediate position that can be separated into the proportional stress of the wheel load when the average is taken and the proportional stress of the longitudinal creep force when the difference is taken.

  In the present invention, the detection that the wheels of the railway vehicle pass through an intermediate position between adjacent sleepers is performed, for example, by attaching a single-axis strain gauge to the rail bottom of the intermediate position in the rail laying direction and passing through the wheels. What is necessary is just to judge with the peak value of the stress of time, or to detect the passing wheel with a laser displacement meter.

  In order 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. Thereby, the calibration value of the longitudinal creep force can be obtained at the site based on the relationship calculated in advance by calibrating the wheel load at the site.

  For example, using the known wheel weight calibration method described on pages 102 to 112 of the “Regular Railway Driving Speed Improvement Test Manual / Comment (Supervised by the Railway Bureau, Ministry of Transport)”, wheels and rails are used. It is possible to calibrate the longitudinal creep force acting on the contact portion of the contact, and to measure the longitudinal creep force.

  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. The longitudinal creep force acting on the contact portion of the rail can be measured.

  Therefore, when applying oil or lubricant to the tread of the rail from the ground side, the longitudinal creep force can be measured on the ground side, so the amount of oil and lubricant applied can be fed back in a timely manner. Can be optimally controlled. In addition, it is possible to monitor from the ground side the state of the monolink that supports the axle box in the front-rear direction of all vehicles that pass over the point where the longitudinal creep force is measured.

  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 and the front / rear support state of all vehicles traveling on the rail. .

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 surface of a rail, (b) is the figure seen from diagonally upward. (A) is the figure which showed the Wheatstone bridge circuit at the time of measuring longitudinal creep force in this invention, (b) is the time in this invention, when measuring the vertical load to the rail loaded for calibration of longitudinal creep force It is the figure which showed an example of the 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 away from the intermediate position between adjacent sleepers in the rail installation direction front. It is the figure which showed an example of the maximum principal stress by the wheel load in the position 0.2 m away from the intermediate position between adjacent sleepers in the rail installation direction back. It is the figure which showed an example of the maximum principal stress by the longitudinal creep force in the position 0.2m away from the intermediate position between adjacent sleepers in the rail installation direction front. It is the figure which showed an example of the maximum principal stress by the longitudinal creep force in the position 0.2 m away from the intermediate position between adjacent sleepers in the rail installation direction back. (A) (b) is the figure seen from the side of the rail explaining the other example of the detection means that the wheel passed the intermediate position between adjacent sleepers in this invention. (A) is the figure which showed an example of the sticking position of the strain gauge for removing the influence of the stress by the lateral pressure which generate | occur | produces in a rail, (b) is an example of the Wheatstone bridge circuit which connected the strain gauge of (a). FIG.

  An object of the present invention is to make it possible to measure a longitudinal creep force acting on a contact portion between a wheel and a rail of a railway vehicle from the ground side. The purpose of this is to measure the principal stress generated in the rail by a probe installed on the ground side, and convert it from the relationship between the pre-determined relationship between the wheel load and the principal stress difference between the longitudinal creep force and the longitudinal creep force. Realized by obtaining.

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

  Conventionally, there is a technique for measuring an axial force generated in a long rail. 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 railway vehicle can also be measured from the ground side by attaching a strain gauge to the rail, for example.

  However, when a strain gauge is attached to the rail and the load applied to the contact position between the wheel and the rail is measured from the ground side, the load is actually applied using a hydraulic jack etc. on the site, and accurate calibration is not performed. I don't know the value.

  The wheel load (load) acting in the direction perpendicular to the rail is applied on-site as described on page 105 of the “Regular Railway Driving Speed Improvement Test Manual / Explanation” explained earlier. Can be calibrated. On the other hand, since the action direction of the longitudinal creep force is a 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 relationship is obtained in advance by theoretical analysis or FEM analysis, the main stress generated in the rail due to the longitudinal creep force can be calculated in the field using a hydraulic jack or the like from the vertical direction of the rail in the same manner as the calibration of the wheel load. Can be calibrated on load.

The present invention has been made based on the above idea of the inventors.
For example, as shown in FIG. 1, the sleepers 2 that support the rails 1 are equally spaced from the intermediate position Pc between the adjacent sleepers 2 toward the front and rear in the laying direction of the rails 1, for example, 0.2 m. 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.

  For example, as shown in FIG. 1B, the measurement of the main stress at the positions P1 and P2 is symmetrical in the longitudinal direction of the laying direction and the center line in the width direction of the rail 1 when the rail 1 is cross-sectionalized. Uniaxial strain gauges 4A1, 4B1 and 4A2, 4B2 are attached 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 principal stress direction during the wheel load action and the principal stress generated in the rail 1 is measured. At that time, the strain gauges 4A1, 4B1 and 4A2, 4B2 are attached to the intermediate position Pc in a diagonally upward direction of 45 °, for example. This is because, in actual work, workability is good in the case of 45 ° obliquely upward.

  Moreover, in FIG. 1, these strain gauges 4A1, 4B1 and 4A2, 4B2 are affixed in the vicinity of the center position in the height direction of the web 1a of the rail 1. 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.

  Further, FIG. 1 shows that 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, 4B1, 4A2, and 4B2, and the measured main stress is input to the calculator 6. To do.

  The main stress input to the calculator 6 is the difference between the main stresses measured at the positions P1 and P2, and can be obtained by assembling the Wheatstone bridge circuit B shown in FIG. Thus, by taking the difference between the main stresses measured at the positions P1 and P2, 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 that are equally spaced from the intermediate position Pc in the longitudinal direction of the rail 1, the wheel load P when the wheels 3 of the railway vehicle pass the intermediate position Pc is the same. On the other hand, the rail strain due to the longitudinal creep force T has different directions, that is, signs at the positions P1 and P2.

  The computing unit 6 converts the principal stress caused by the longitudinal creep force from the relationship between the principal stress generated in the rail by the wheel load P and the principal stress generated in the rail by the longitudinal creep force T, which has been obtained in advance. Find the creep force.

  The relationship between the main stress generated in the rail by the wheel load P and the main stress generated in the rail by the longitudinal 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 sleepers 2 The distance to the contact position with 3 is r ₁ . Further, an angle on the rear side in the laying direction formed by the strain gauges 4A2 and 4B2 at the position P2 and the horizontal line is θ ₂ , and a distance from the strain gauges 4A2 and 4B2 to the contact position at the position P2 is r ₂ . In this case, the expression of the stress field at the positions P1 and P2 can be expressed as follows.

(Main stress due to wheel load P)
σr = (2P / π) × (sinθ / r) = ε _P · E
(Main stress due to longitudinal creep force T)
σr = (2T / π) × (cosθ / 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

Further, at the position P2, the strain due to the wheel load and the strain due to the longitudinal 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, each measured value (principal stress) when a strain gauge is attached to the positions P1 and P2 can be expressed by the following formula.
ε ₁ = K ₁ · P · sin θ ₁ + K ₁ · T · cos θ ₁
ε ₂ = K ₂ · P · sinθ ₂ + K ₂ · T · cos θ ₂

In the equation for obtaining the measured values at the positions P1 and P2, when r ₁ = r ₂ = r, θ ₁ = θ, θ ₂ = π−θ, the wheel load P and the longitudinal creep force T are obtained by the following equations. Can do.
P = (1 / Ksinθ) × (ε ₁ + ε ₂ )
T = (1 / Kcosθ) × (ε ₁ −ε ₂ )

  Therefore, the relationship between the main stress caused by the wheel load P and the main stress caused by the longitudinal creep force T can be obtained in advance by the above formula.

  The relationship between the main stress caused by the wheel load P and the longitudinal creep force T is not only converted from the principal stress caused by the longitudinal creep force into the longitudinal creep force, but also changed to the Wheatstone bridge circuit B shown in FIG. It is also possible to calibrate the wheel load on site and calibrate the longitudinal creep force on site.

  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 principal stress is in the direction of 45 °, as shown in FIGS. 3 to 6, at a point 90 mm in the front-rear direction from the load point.

  Assuming that the roadbed is a ballast roadbed, the same FEM analysis was performed with a Young's modulus of 27.9-47.9 MPa, and the principal stress was in the direction of 45 ° in the range of 85-120 mm from the load point to the front-back direction. It was.

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

  Further, as shown in FIG. 1, the following Table 1 shows that a strain gauge is attached in a 45 ° upward direction toward the intermediate position Pc symmetrically in the longitudinal direction at the positions P1 and P2, and the following loads are applied to the intermediate position Pc. The principal stress in the 45 ° direction when applied is shown.

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

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

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate 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 adopted, the main stress may be obtained from the measurement output, or the position of the strain gauge applied to the positions P1 and P2 is adjusted so as to be directed to the principal 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, but a strain gauge 4C is attached to the rail 1 at the intermediate position between adjacent sleepers as shown in FIG. The passing of the wheel may be detected by the peak value of the measured stress. In this case, as shown in FIG. 7 (a), even if the strain gauge 4C is attached in the height direction to the center position of the web 1a of the rail 1 in the height direction 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.

  In the above embodiment, the main stress is measured to obtain the longitudinal creep force. However, the longitudinal creep force may be obtained from the main strain.

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

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

  Further, by measuring the longitudinal creep force during traveling in a straight section from the ground using the present invention, it is possible to monitor the front-rear instruction state of the axle box of the traveling vehicle.

1 rail 2 sleeper 3 wheel 4A1, 4B1, 4A2, 4B2 strain gauge 4C strain gauge 5 laser displacement meter 6 computing unit Pc intermediate position P1 position in front of installation direction P2 position in rear of installation direction B Wheatstone bridge circuit P wheel load T vertical creep Force CL rail width center line

Claims (14)

The main stress generated in the rail when the wheel of the railroad vehicle passes through the intermediate position at two locations that are equidistant from each other in the longitudinal direction of the rail, from the intermediate position between adjacent sleepers that support the rail, or Measure the main strain,
The difference between the principal stress or the principal strain at these two measured locations is determined in advance by theoretical analysis or finite element analysis, and the principal stress or principal strain generated by the wheel load and the principal stress generated by the longitudinal creep force. A method of measuring a longitudinal creep force between a wheel and a rail of a railway vehicle, wherein the longitudinal creep force is converted based on a relationship between stress or principal strain.   2. The measurement of principal stress or principal strain at the two locations is performed at the positions of the front and back surfaces of the rail web that are line-symmetric with respect to the center line in the width direction when the rail is cross-sectionalized. A method for measuring a longitudinal creep force between a wheel and a rail of a railway vehicle according to claim 1.   The rail creeper wheel according to claim 1 or 2, wherein the longitudinal creep force is calibrated based on the relationship obtained in advance by calibrating the wheel load. Longitudinal creep force measurement method.   The position of the two places is a position separated by 85 to 120 mm from the intermediate position in the front and rear of the rail laying direction, respectively. Of measuring the vertical creep force.   The principal stress or principal strain is measured with a strain gauge affixed in a 45 ° obliquely upward direction toward the top surface of the rail at the intermediate position at the center position in the height direction of the rail at the two positions. The method for measuring a longitudinal creep force between a wheel and a rail of a railway vehicle according to any one of claims 1 to 4.   6. The method of measuring a longitudinal creep force between a wheel and a rail of a railway vehicle according to claim 5, wherein the strain gauge is one of a single axis, a biaxial axis, and a triaxial axis.   The detection that a wheel of a railway vehicle has passed an intermediate position between adjacent sleepers is performed by a laser displacement meter, and the longitudinal distance between the wheel and the rail of the railway vehicle according to any one of claims 1 to 6 is characterized. Creep force measurement method.   Detecting that the wheel of a railway vehicle has passed through an intermediate position between adjacent sleepers is detected using a strain gauge attached to the rail web in the height direction or on the rail bottom surface in the rail laying direction at the intermediate position. 7. The method for measuring a longitudinal creep force between a wheel and a rail of a railway vehicle according to any one of claims 1 to 6, wherein the peak value of the stress when the wheel passes is performed. A measuring element that measures the main stress or main strain of the rail symmetrically in the longitudinal direction of the rail in two locations that are equally spaced in the longitudinal direction of the rail from the intermediate position between adjacent sleepers that support the rail; and
Means for detecting that a wheel of the railway vehicle passes through the intermediate position;
When the wheel passes the intermediate position, the average of the principal stress or principal strain is obtained by taking the difference from the mean principal stress or principal strain at the two measurement positions before and after the measurement by the probe. The main stress or main strain due to a certain wheel load is separated into the main stress or main strain due to the longitudinal creep force that is the difference between the main stress or main strain, and the main stress or main strain due to the separated vertical creep force is obtained in advance. An arithmetic unit that obtains a longitudinal creep force in terms of the relationship between the principal stress or principal strain generated by the wheel load and the principal stress or principal strain generated by the longitudinal creep force;
A device for measuring a longitudinal creep force between a wheel and a rail of a railway vehicle.   The longitudinal creep force measurement between a wheel and a rail of the railway vehicle according to claim 9, wherein the two positions are positions separated from the intermediate position by 85 to 120 mm in front and rear of the rail laying direction. apparatus.   The apparatus for measuring a vertical creep force between a wheel and a rail of a railway vehicle according to claim 9 or 10, wherein the measuring element is a strain gauge of any one of a single axis, a biaxial axis, and a triaxial axis.   12. The railway vehicle according to claim 11, wherein the measuring element is affixed to the front and back surfaces of the rail web that is line-symmetric with respect to the center line in the width direction when the rail is cross-sectionalized. Vertical creep force measuring device between wheels and rails.   The said measuring element is affixed in the 45 degree diagonally upward direction which goes to the top face of the rail in the said intermediate position from the height direction center position of the rail in the said two places. An apparatus for measuring a longitudinal creep force between a wheel and a rail of a railway vehicle as described in 1.   Means for detecting that the wheel of the railway vehicle has passed through an intermediate position between adjacent sleepers is a laser displacement meter, a strain gauge attached to the rail web in the height direction at the intermediate position, and the bottom surface of the rail at the intermediate position. The apparatus for measuring a vertical creep force between a wheel and a rail of a railway vehicle according to any one of claims 9 to 13, wherein the strain gauge is any one of strain gauges attached to a rail laying direction.

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