JP2011220835A - Fatigue testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fatigue testing device which can easily evaluate abrasion resistance and fatigue damage resistance in straight line section and curved line section of a rail to be actually laid without upsizing by reproducing the condition in which the rail to be actually laid and wheels are in contact with each other.SOLUTION: A fatigue testing device 1 has a testing machine 10 and an angle changing plate 20 which is connected facing the testing machine 10 and can rotate. While the load of a rotating and touching wheel 40 and a testing wheel 50 is constant and the angle changing plate 20 is rotated against the testing machine 10, the fatigue testing device 1 has an output means 90 which outputs over time an angle of attack between the attached wheel 40 and the testing wheel 50, a rotation frequency of the wheel 40 and the testing wheel 50, and a load detected by a load detection means 70. Thus, from these number values, abrasion resistance and fatigue damage resistance in a straight line section and a curved line section of a rail to be actually laid can easily be evaluated.

Description

  The present invention relates to a fatigue test apparatus for simulating wear and rolling fatigue damage at the time of contact between a rail and a wheel in a straight section and a curved section of a rail for a railway or the like.

Traditionally, rail transport is more efficient and environmentally friendly than other transport facilities, so it has been actively promoting higher operating speeds, increased freight load on freight cars, and congestion of diamonds. It has been.
As a result, the load on steel rails (rails) has become severe, and the wear resistance, fatigue damage resistance, or dark spot damage resistance of the rails due to rolling of wheels has been emphasized.

In recent years, before exchanging the rail due to wear, cracks have occurred in the gauge corner portion (hereinafter referred to as the GC portion), which is the contact portion of the rail with the wheel, and the frequency of rail replacement has increased. For this reason, a crack in the GC portion is regarded as a problem.
In particular, a high-strength rail has been used for the rail used in the curved track section so far, from the viewpoint of improving wear resistance and fatigue damage resistance. However, the wear resistance of the GC portion is different from that of the conventional rail. There is also a need for a rail that has characteristics equal to or better than those and that suppresses the occurrence of cracks that cause replacement.

And when evaluating the wear resistance, fatigue damage resistance, and crack crack resistance of the rail described above, it is most desirable to actually lay the rail and evaluate it, but there are the following problems.
(1) It takes a long time to complete the rail characteristic evaluation.
(2) It costs a lot of money to install and remove rails.
Therefore, in recent years, there has been a demand for development of a fatigue test apparatus that can easily evaluate and reproduce wear resistance, fatigue damage resistance, and crack resistance without actually laying rails. In response to this requirement, experiments have been conducted with several fatigue test apparatuses. Hereinafter, these fatigue test apparatuses will be briefly described.

(Nishihara type wear test equipment)
Non-Patent Document 1 discloses a Nishihara type wear test apparatus. The Nishihara-type wear test device is a test device that rotates two cylindrical test wheels at different speeds and presses the sides of each test wheel to measure wear characteristics in a sliding wear state. In other words, it is a two-cylinder contact type small test apparatus that evaluates materials for wear as well as rails.
Patent Document 1 and Patent Document 2 disclose a rail rolling fatigue test apparatus. According to these documents, a rolling fatigue test is disclosed in which a load load and a test speed can be adjusted in a fatigue test of a long object such as a rail.

  Patent Document 3 discloses a rail and wheel fatigue test apparatus. In this document, a test wheel rotatably supported, a lateral pressure load mechanism, a test wheel device unit, a wheel load mechanism, a contact angle application mechanism, an attack angle application mechanism, and a wheel device unit are provided. A rail and wheel fatigue testing apparatus is disclosed. Specifically, the lateral pressure load mechanism moves the test wheel in the axial direction and applies a lateral pressure to a wheel to be described later. The test wheel device section includes an absorbing member that is moved in the axial direction by the lateral pressure load mechanism and a rotation source of the test wheel that is directly connected via a flywheel. The wheel load mechanism moves a wheel rotatably supported at a position facing the test wheel, and moves the wheel in a radial direction on the test wheel side. The contact angle applying mechanism rotates the wheel by a required angle within the same plane around the contact point with the test wheel as in the wheel load mechanism. Moreover, the said attack angle provision mechanism makes the said wheel rotate the predetermined angle to the direction orthogonal to an axis | shaft with respect to a test wheel similarly to the said contact angle provision mechanism. The wheel device section includes a member that absorbs the displacement of the wheel by the contact angle applying mechanism and the attack angle applying mechanism, and a wheel rotation source that is directly connected via a brake mechanism. That is, the fatigue test apparatus disclosed in Patent Document 3 is a fatigue test apparatus in which the test wheel and the wheel have the same cross-sectional shape as the actual product.

Japanese Examined Patent Publication No. 05-35818 Japanese Patent Publication No.58-16464 Japanese Patent Publication No. 6-12323

Lubricating wear of metal and its countermeasures, Kiyoichi Ogawa, Yokendo, 1977

However, when performing tests for wear resistance, fatigue damage resistance, and crack resistance using the test devices disclosed in Non-Patent Document 1, Patent Document 1 and Patent Document 2, there are the following problems. .
Since the test device of Non-Patent Document 1 uses a test wheel having a diameter of 30 mm, it is possible to collect the test wheel from the actually manufactured rail. However, the attack angle cannot be given and the contact between the rail and the wheel in the straight section can be simulated, but the simulation cannot be performed in the curved section which is a severe use environment. For this reason, rail wear and fatigue damage in the straight section can be simulated, but rail wear, fatigue damage, and cracking in the curved section cannot be simulated. Here, the attack angle is an angle formed by the tangential direction of the rail having a curvature and the peripheral speed vector of the wheel. In addition, since the load is applied by the spring method, the test wheel vibrates during the test, and the load fluctuation always occurs. Further, if the test is performed for a long time, the test wheel may crack and the test wheel may be damaged, so that it is impossible to investigate the accurate rolling fatigue characteristics.
The attack angle cannot be given in the same manner with the test devices of Patent Document 1 and Patent Document 2, and these test devices simulate the contact between the rail and the wheel in the straight section using the actual rail. Can evaluate fatigue damage resistance, but it cannot simulate a curved section, which is a severe use environment.

On the other hand, since the test apparatus of Patent Document 3 can also give an attack angle, it is possible to simulate the contact between the rail and the wheel in a straight section and a curved section which is a severe use environment. In addition, since a full-size wheel is used, an evaluation test similar to the actually laid rail is possible. However, there are problems (a) and (b) below.
(A) The shape of the wheel is full-scale, the rigidity of the test wheel needs to be the same size as the wheel, and the test wheel cannot be sampled from the actual rail. Therefore, forging and heat treatment are performed to produce a simulated test wheel or wheel, the structure and characteristics of the actual rail and the test wheel for testing are different. In addition, since the test wheels and wheels are large, forging and heat treatment processing and the like are very expensive and time consuming, a large cost is required for each test.

(B) Since the test wheel and the wheel become large, it is necessary to introduce a hydraulic device in order to control the load and the attack angle. By controlling with a hydraulic device, the structure of the test device can be simplified. However, since the piping is required, the test device is enlarged. Further, when hydraulic pressure is used, the following problems (b-1) to (b-3) occur.
(B-1) Pressure and speed fluctuate due to fluctuations in oil temperature. That is, the load load and the attack angle fluctuate during the test, and the test wheel and the rotation speed of the wheel and the test conditions fluctuate during the test.

(B-2) When the test wheel and the wheel are made small so that the test wheel can be collected from the actual rail, it is necessary to reduce the diameter of the shaft to be attached. Since the load device uses hydraulic pressure, a large force is applied to the test wheel and the attached shaft, which may cause damage. Therefore, when using a hydraulic apparatus, the diameter of a test wheel, a wheel, and the shaft to attach cannot be made small.
(B-3) When the test is performed with the wheel shape being the actual size and the load load being reduced, the load control becomes difficult, and the load load fluctuations and vibrations increase during the test.
Therefore, the present invention has been made in view of the above-mentioned problems, and the purpose thereof is to increase the wear resistance and fatigue damage resistance in the straight section and the curved section of the actually laid rail without increasing the size. An object of the present invention is to provide a fatigue test apparatus that can easily evaluate the above.

  In order to solve the above-mentioned problems, the present inventors have made extensive studies, and as a result, wear and fatigue damage due to contact between the rail and the wheel in the straight section and the curved section with the same composition and mechanical characteristics as the actually laid rail. It is possible to evaluate the wear resistance and fatigue damage resistance of the rail by reproducing the cracks and applying the Hertz contact stress at the time of contact between the rail and the wheel at the time of contact between the actual rail and the wheel. I found out. In other words, a test wheel with a size that can be taken from the head (evaluation part) of the actual rail is arranged so that its rotating shaft can rotate with respect to the rotating shaft of the wheel, and an attack angle is easily given. I tried to do it. By doing in this way, load load was made small and the contact stress of Hertz at the time of contact with a rail (test wheel) and a wheel was reproduced.

The present invention is based on the above knowledge obtained by the present inventor, and the fatigue test apparatus according to claim 1 of the present invention for solving the above-described problems is a cylindrical wheel on a plurality of drive shafts that are independently driven to rotate. In addition, a fatigue test apparatus that wears and rolls fatigue damage to the test wheel by attaching a cylindrical test wheel and pressing the wheel and the test wheel while rotating each other,
A test machine table, and an angle changing plate coupled rotatably along the upper surface of the test machine table,
A first drive shaft having the wheel mounted thereon, and a first drive generating means for rotating the first drive shaft around its axial direction is provided in the test machine base;
A second drive shaft on which the test wheel is mounted, and a second drive generating means for rotating the second drive shaft around the axial direction is provided on the angle change plate;
Of the wheels and the test wheels that are rotated by the first drive shaft and the second drive shaft, a load load that contacts the peripheral surface of the test wheel with the peripheral surface of the wheel and applies a load to the test wheel Means are provided on the angle changing plate;
Attack angle detection means for detecting an attack angle formed by the axial direction of the second drive shaft with respect to the axial direction of the first drive shaft by rotating the angle changing plate along the upper surface of the test machine base; ,
A load detecting means for detecting a load of the test wheel with respect to the wheel;
Control means for controlling the load load means such that the load load detected by the load load detection means is constant;
Output that correlates with time the respective rotation speeds of the first drive shaft and the second drive shaft, the load load detected by the load load detection means, and the attack angle detected by the attack angle detection means Means.

  According to the first aspect of the present invention, the rotational speed of the first drive shaft 11 obtained from the first drive generation means 12 with time, the second drive shaft obtained from the second drive generation means 22. 21, the temporal load load detected by the load detection means 70, and the attack angle θ detected by the attack angle detection means 60 are obtained, and these information are correlated over time. It is possible to evaluate the wear resistance and fatigue damage resistance of the rail in the curved section.

A fatigue test apparatus according to claim 2 of the present invention is the fatigue test apparatus according to claim 1, further comprising lubricant supply means for supplying a lubricant to at least one of the wheel and the test wheel. It is a feature.
A fatigue test apparatus according to claim 3 of the present invention is the fatigue test apparatus according to claim 1 or 2, wherein the diameter of the wheel and the test wheel is 50 mm or less.

Moreover, the fatigue test apparatus according to claim 4 of the present invention is the fatigue test apparatus according to any one of claims 1 to 3, wherein the attack angle is greater than 0 (rad) and less than ± 3 (rad). It is characterized by that.
A fatigue test apparatus according to a fifth aspect of the present invention is the fatigue test apparatus according to any one of the first to fourth aspects, wherein the test wheel is rail steel.

  According to the fatigue test apparatus according to the present invention, since the test wheel is taken from the actual rail, the characteristics of the rail to be laid can be evaluated without increasing the size, and when the rail is actually laid. It is possible to provide a fatigue test device that can easily evaluate the wear resistance and fatigue damage resistance of a rail laid in a straight section and a curved section by reproducing the state at the time of contact between the rail and the wheel. it can.

It is a top view which shows the structure in one Embodiment of the fatigue test apparatus which concerns on this invention. It is a front view which shows the structure in one Embodiment of the fatigue test apparatus which concerns on this invention. It is a right view which shows the structure in one Embodiment of the fatigue test apparatus which concerns on this invention. It is an arrow view of the direction of A of FIG. It is a figure which shows the structure of the wheel in one Embodiment of the fatigue test apparatus which concerns on this invention, and a test wheel. It is a block diagram which shows the structure in one Embodiment of the fatigue test apparatus which concerns on this invention.

Hereinafter, an embodiment of a fatigue test apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a configuration in an embodiment of a fatigue test apparatus according to the present invention. FIG. 2 is a front view showing a configuration in an embodiment of the fatigue test apparatus according to the present invention. FIG. 3 is a side view showing a configuration in an embodiment of the fatigue test apparatus according to the present invention. FIG. 4 is a view in the direction of arrow A in FIG. FIG. 5 is a front view and a side view showing the configuration of the wheel and the test wheel in one embodiment of the fatigue test apparatus according to the present invention, and (a) is a front view and a side view showing the configuration of the wheel. (B) is the front view and side view which show the structure of a test wheel (arc shape whose evaluation surface is R15). FIG. 6 is a block diagram showing a configuration in an embodiment of the fatigue test apparatus according to the present invention. In addition, in FIG. 1, each member provided in the angle change plate 20 and the angle change plate 20 when the attack angle mentioned later is provided is shown with the broken line. Moreover, in FIG. 3, the arm part 25 when driving the load load generation means 23 and unloading is shown with the broken line.
As shown in FIGS. 1 to 6, the fatigue test apparatus 1 according to the present invention includes a test machine base 10, an angle changing plate 20, a load load generating means 23, an attack angle detecting means 60, and a load load detecting means. 70, control means 80, and output means 90.

<Test machine stand>
As shown in FIGS. 1 to 4, the test machine base 10 includes a first drive shaft 11 that can be driven to rotate, a first drive generation means 12 that drives the first drive shaft 11 to rotate, and an attack. Corner detection means 60 (61, 62) is provided.
The first drive generating means 12 is, for example, an electric motor having a stator and a rotor, and the first drive shaft 11 may be integrally formed with the rotor or connected via a coupling. 1-4, illustration of the power supply of the 1st drive generation means 12 is abbreviate | omitted.

  The test machine base 10 has a flat plate shape, and the first drive generating means 12 is fixed to the upper surface of the test machine base 10. The first drive generating means 12 is installed on the test machine base 10 so that the axial direction of the first drive shaft 11 and the upper surface of the test machine base 10 are parallel to each other. A cylindrical wheel 40 is attached to the end of the first drive shaft 11 with the axial direction of the first drive shaft 11 and the thickness direction of the wheel 40 parallel to each other. Therefore, as the first drive shaft 11 is rotated about its axial direction by the first drive generating means 12, the wheel 40 rotates about its thickness direction as an axis.

[Wheel]
As shown in FIG. 5A, the shape of the wheel 40 is a cylindrical shape, and the end of the first drive shaft 11 is fitted to the inner peripheral surface of the wheel 40 so that the first drive shaft 11 is fitted. Wheels 40 are attached. The diameter of the annular plane portion of the wheel 40 is 50 mm or less. Specific dimensions of the wheel 40 are a diameter of 30 mm, a thickness of 8 mm, and an inner diameter of 16 mm (same as the diameter of the first drive shaft 11).

<Angle change plate>
The angle changing plate 20 has a flat plate shape like the test machine base 10 and is formed smaller than the test machine base 10.
Here, the angle changing plate 20 is installed on the upper surface of the test machine table 10 via the support shaft 30 so that the lower surface of the angle change plate 20 faces the upper surface of the test machine table 10 and rotates along the upper surface. That is, the support shaft 30 provided on the lower surface of the angle changing plate 20 is rotatably inserted into the support hole 13 formed on the upper surface of the test machine base 10 via the bearing. Thus, since the support shaft 30 is rotatable with respect to the support hole 13, the angle changing plate 20 is installed so as to be rotatable with respect to the test machine base 10. It is preferable that the rotation center of the angle changing plate 20 with respect to the test machine base 10 (installation position of the support hole 13 in the test machine base 10) is formed below a contact position between the wheel 40 and the test wheel 50 described later.
Accordingly, the size of the angle change plate 20 is the same as that of the first change in which the angle change plate 20 is fixed to the upper surface of the test machine table 10 when the angle change plate 20 is rotated along the upper surface of the test machine table 10. The size is set so as not to interfere with the drive generating means 12.

The angle changing plate 20 is provided with a second drive shaft 21 that can be rotationally driven, a second drive generating means 22 that rotationally drives the second drive shaft 21, and a load load generating means 23. .
A rectangular parallelepiped support block 24 is erected on the upper surface of the angle changing plate 20 perpendicularly to the upper surface. On the upper end portion of the support block 24, an arm portion 25 that is rotatable on a plane perpendicular to the upper surface of the angle changing plate 20 is supported. A second drive generating means 22 extending in a direction perpendicular to the rotation direction of the arm portion 25 is connected to one end of the arm portion 25, and a load load generating means 23 is connected to the other end of the arm portion 25. Yes.

The second drive generating means 22 is, for example, an electric motor having a stator and a rotor, like the first drive generating means 12, and the second drive shaft 21 may be integrally formed with the rotor, and the cup It may be connected via a ring. Note that the second drive generation unit 22 projects the second drive shaft 21 so as to face the first drive shaft 11 projected from the first drive generation unit 12. In addition, the rotation direction of the second drive shaft 21 that is driven to rotate by the second drive generation unit 22 is opposite to the rotation direction of the first drive shaft 11 that faces the second drive shaft 21. 1-4, illustration of the power supply of the 2nd drive generation means 22 is abbreviate | omitted.
The second drive generating means 22 is installed so that the axial direction of the second drive shaft 21 and the upper surface of the angle changing plate 20 are parallel to each other. A cylindrical test wheel 50 is attached to the end of the second drive shaft 21.

[Test wheel]
As shown in FIG. 5B, the test wheel 50 has a cylindrical shape, and the second drive shaft 21 is fitted to the inner peripheral surface of the test wheel 50 by fitting the end of the second drive shaft 21. A test wheel 50 is attached to the shaft 21. The material of the test wheel 50 is preferably rail steel, and is taken from an actual rail. The diameter of the annular plane portion of the test wheel 50 is 50 mm or less. Specific dimensions of the test wheel 50 are a diameter of 30 mm, a thickness of 8 mm, and an inner diameter of 16 mm (same as the diameter of the second drive shaft 21). As the shape of the test wheel 50 used in the fatigue test apparatus 1, the contact surface (the peripheral surface of the test wheel 50 to be brought into contact with the peripheral surface 31 of the wheel 40 in the friction test) 41 is a contact surface with a curved surface of R15. You may have.

  Since the second drive generating means 22 is installed at one end of an arm portion 25 that is rotatably connected to a support block 24 that is erected vertically on the upper surface of the angle changing plate 20, the arm portion 25. The height from the upper surface of the angle change plate 20 can be changed by rotating the lens (inclination with respect to the upper surface of the angle change plate 20). However, in the reference state in which the arm portion 25 is parallel to the upper surface of the angle change plate 20. The second drive shaft 21 directly connected to the second drive generation means 22 is positioned higher than the first drive shaft 11 of the first drive generation means 12 provided on the test machine base 10. Further, the connection position of the arm portion 25 with respect to the support block 24 is determined. When the arm portion 25 is in the reference state, the test wheel 50 attached to the end portion of the second drive shaft 21 directly connected to the second drive generation means 22 is connected to the end portion of the first drive shaft 11. It is set to contact above the wheel 40 attached to the wheel. The arm portion 25 is installed to be rotatable with respect to the support block 24 from the reference state, for example, about 15 rad (see FIG. 3).

  In the test machine base 10 and the angle changing plate 20 of the fatigue test apparatus 1 provided in this way, the first drive shaft 11 and the second drive shaft 21 are positioned so that the wheels 40 and the test wheels 50 are positioned in the vertical direction. Are arranged to be. That is, the wheel 40 and the test wheel 50 mounted on each of the plurality of first drive shafts 11 and second drive shafts 21 that are independently rotated are arranged so as to be positioned in the vertical direction. That is, in the reference state, the first drive shaft 11 and the second drive shaft 21 are parallel with the peripheral surface of the wheel 40 and the peripheral surface of the test wheel 50 in contact (the attack angle θ = described later). 0 (rad)).

  When the first drive shaft 11 and the second drive shaft 21 are rotated while applying a load load from the load load generating means 23 to the test wheel 50 in this reference state, a test simulating a straight section can be performed. In addition, when the operator rotates the angle changing plate 20 with respect to the test machine base 10 from the reference state by a predetermined angle, the attack angle θ can be given to the wheel 40 and the test wheel 50, Thus, when the first drive shaft 11 and the second drive shaft 21 are rotated while a load is applied to the test wheel 50 by the load load generating means 23, a test simulating a curved section can be performed. The attack angle θ is an angle formed between the test wheel 50 and the wheel 40 with the wheel 40 as a reference. The attack angle θ is preferably greater than 0 (rad) and not greater than ± 3 (rad).

The angle change plate 20 may be provided with a hand lever 27 that presses and fixes the angle change plate 20 against the test machine base 10 (see FIG. 1). By loosening the hand lever 27, the angle changing plate 20 can be rotated with respect to the test machine base 10, and by tightening the hand lever 27, the angle changing plate can be moved before and after giving the attack angle θ to the wheel 40 and the test wheel 50. It is comprised so that it can fix to the testing machine base 10. FIG. Thereby, since the attack angle θ does not fluctuate during the test, a good evaluation result can be obtained.
Further, since the drive generators 12 and 22 are connected to the wheel 40 and the test wheel 50, the fatigue test apparatus 1 can be tested by generating slip by changing the number of revolutions. It is.

<Lubricant supply means>
Here, the fatigue test apparatus 1 includes a first lubricant supply unit 14 that supplies water as a lubricant to the test wheel 50 and a second lubricant supply unit 26 that supplies oil as a lubricant to the test wheel 50. Is preferably provided.
The lubricant supply means 14 has a tank for storing water, a nozzle for injecting water to the test wheel 50, and a water supply pipe for sending water from the tank to the nozzle, and is injected from the nozzle to the rotating test wheel 50. The The control of the injection may be performed by the control device 80 by connecting the first lubricant supply unit 14 to the control device 80.

The second lubricant supply means 26 has a tank for storing oil, a nozzle for injecting oil onto the test wheel 50, and an oil feed pipe for sending oil from the tank to the nozzle, and a test rotating from the nozzle. It is injected into the wheel 50. The control of the injection may be performed by the control device 80 by connecting the second lubricant supply means 26 to the control device 80.
In FIG. 2, the first lubricant supply means 14 is provided on the test machine base 10 and the second lubricant supply means 26 is provided on the angle changing plate 20. The installation of the agent supply means may be reversed, and both the first lubricant supply means 14 and the second lubricant supply means 26 may be installed in either the test machine 10 or the angle changing plate 20.

  In the above description, the object to which the first lubricant supply means 14 and the second lubricant supply means 26 supply water or oil is the test wheel 50, but this is because the test wheel 50 is more than the wheel 40. The water or oil supplied to the test wheel 50 is also supplied to the wheel 40 located below the test wheel 50. Therefore, in the fatigue test apparatus 1 configured such that the wheel 40 is positioned above the test wheel 50, the first lubricant supply means 14 and the second lubricant supply means 26 supply water or oil. The object is the wheel 40 located above.

<Load load generating means>
The load load generating unit 23 causes the test wheel 50 attached to the second drive shaft 21 and the wheel 40 attached to the first drive shaft 11 to press the test wheel 50 against the wheel 40 to test the wheel. 50 is a means for generating wear and rolling fatigue damage. Specifically, the load load generating means 23 includes a support portion 23a fixed to the angle changing plate 20, a hinge portion 23b rotatably connected to the end portion of the arm portion 25, a ball screw 23c, a ball A motor 23e that rotationally drives the screw shaft 23d of the screw 23c. The ball screw 23c includes a screw shaft 23d, a nut portion 23f, and a large number of rolling elements interposed in rolling grooves formed in a spiral shape on each of the outer peripheral surface of the screw shaft 23d and the inner peripheral surface of the nut portion 23f. (Not shown). The outer peripheral surface of the nut portion 23 f is fixed so as to be sandwiched between two support portions 23 a fixed to the lower surface of the angle changing plate 20. One end portion of the screw shaft 23d is connected to a motor 23e fixed to the lower surface of the angle changing plate 20 through a pulley 23g, like the support portion 23a. The other end of the screw shaft 23d is connected to the lower surface of the hinge 23b via a load 70.

With such a configuration, the rotation of the motor 23e causes the nut portion 23f to move relative to the screw shaft 23d, thereby changing the height of the end portion of the arm portion 25 with respect to the angle changing plate 20. As a result, The pressing force of the test wheel 50 against the wheel 40 can be changed.
Here, the motor 23 e is connected to the control means 80 and is driven to rotate based on the load load transmitted from the control means 80.

<Attack angle detection means>
The attack angle detection means 60 is a means for detecting an angle obtained by rotating the angle changing plate 20 with respect to the test machine base 10. The angle sensor 61 is a sensor that is installed on the test machine base 10 and converts a mechanical displacement amount of the rotation of the support shaft 30 relative to the test machine base 10 into an electrical signal, and can process this signal to detect the rotation. For example, a rotary encoder is used.
The attack angle θ for rotating the angle changing plate 20 with respect to the test machine base 10 is as small as 0.1 °. Therefore, if the angle sensor 61 cannot detect the rotation angle with the corresponding accuracy, the attack angle detection is performed. As the means 60, an angle sensor 61 and a distance measuring sensor 62 may be used.

The distance measuring sensor 62 is, for example, a laser-type sensor that is provided at the upper surface edge of the test machine base 10 and measures the distance between the distance measuring sensor 62 itself and the side surface of the angle changing plate 20. The distance to the angle changing plate 20 changed by the movement is measured, the distance of the reference state measured in advance is calculated, and the result is output to the control means 80.
The attack angle detection unit 60 calculates the attack angle θ with high accuracy based on the angle sensor 61 or the angular displacement and the distance displacement obtained by the angle sensor 61 and the distance measuring sensor 62, and sends the attack angle θ to the control unit 80. Output.

<Load load detection means>
The load load detection means 70 is means for detecting the load load of the test wheel 50 with respect to the wheel 40. The load load detecting means 70 is provided in the load load generating means 23. The load detection means 70 is interposed between the hinge portion 23b and the ball screw 23c. The load detection means 70 is, for example, a compression type load cell (load cell) having a main body 72 and a load button 73. Specific examples thereof include “compression type load cell TCLN-500NA (Tokyo Sokki Research Co., Ltd.). Manufactured)) ”. In such a load detection means 70, a lower pedestal 71 is installed at the upper end of the screw shaft 23 d of the ball screw 23 c, the main body 72 is fixed on the upper surface of the lower pedestal 71, and the upper pedestal slides The load button 73 provided so as to be in contact with the upper base 74 installed on the lower surface of the hinge portion 23b. The lower pedestal 71 and the upper pedestal 74 have a flat plate shape having a larger planar area than the main body 72. By installing the load load detecting means 70 in this way, the load load of the test wheel 50 on the wheel 40 can be detected via the arm portion 25.

<Control means>
The control means 80 is means for controlling the load load means 23 so that the load load detected by the load load detection means 70 is constant. Specifically, the wheel 40 and the test wheel 50 that are in contact with each other with a predetermined load are sometimes in contact with each other because the load may be reduced due to wear that occurs in each of the wheels 40 and the test wheel 50. The control means 80 controls the motor 23e of the load load means 23 in accordance with the load load detected by the load load detection means 70 so as to keep a predetermined load load.
The control unit 80 may control the rotational speeds of the first drive shaft 11 and the second drive shaft 21 with respect to the first drive generation unit 12 and the second drive generation unit 22.

<Output means>
The output unit 90 is connected to the first drive generation unit 12, the second drive generation unit 22, the attack angle detection unit 60, and the load load detection unit 70, and can obtain information obtained by each unit. Has been. Then, the output means 90 includes the rotational speed of the first drive shaft 11 obtained from the first drive generating means 12 with time, and the time of the second drive shaft 21 obtained from the second drive generating means 22. The rotational speed, the attack angle θ detected by the attack angle detection means 60, and the load load over time detected by the load load detection means 70 are correlated and output over time. The output destination is, for example, a control operation panel of a testing machine, a terminal having an evaluation information storage function, or an analysis function. The acquisition and output of the information may be performed by the control unit 80.
As described above, the output unit 90 verifies the temporal relationship among the first drive shaft 11, the second drive shaft 21, the attack angle θ, and the load load together with the surface inspection of the test wheel 50. In addition, the wear resistance and fatigue damage resistance of the rail in the curved section can be evaluated at the same time or one of the characteristics.

<Fatigue test method>
Next, a method of performing a rail wear resistance and fatigue damage resistance test in a straight section and a curved section using the fatigue test apparatus 1 configured as described above will be described below with reference to the drawings.
First, the wheel 40 is attached to the end of the first drive shaft 11, and the test wheel 50 to be tested is attached to the end of the second drive shaft 21. At this time, the axial direction of the first drive shaft 11 and the axial direction of the second drive shaft 21 are the same direction (reference state of the attack angle θ (= 0)). Further, the load load generating means 23 can be used in the state where the wheel 40 and the test wheel 50 are attached to the end portion of the first drive shaft 11 and the end portion of the second drive shaft 21 as the “reference state”. The arm portion 25 is adjusted to a position inclined with respect to the support block 24 so that the peripheral surface of the test wheel 50 has a gap with respect to the peripheral surface of 40. Thereby, the wheel 40 and the test wheel 50 are easily attached to the end portion of the first drive shaft 11 and the end portion of the second drive shaft 21, respectively. When the load load generating means 23 is in the “reference state”, the load load detecting means 70 shows a value smaller than the load load when the test wheel 50 is brought into contact with the wheel 40 during rotational driving. ing.

  Next, the operator uses the input terminal connected to the control means 80 to test the rotational speed of the first drive shaft 11, the rotational speed of the second drive shaft 21, and the wheel 40 during rotational drive. By inputting a load load that is constant when the wheel 50 is brought into contact, the control means 80 drives the load load generating means 23 based on the inputted information, so that the wheel 40 and the test wheel 50 are predetermined. Contact with the applied load. Thereafter, the first drive generator 12 and the second drive generator 22 are driven. As a result, the peripheral surface of the rotating wheel 40 is brought into contact with the peripheral surface of the test wheel 50 rotating in the opposite direction to the wheel 40 with a predetermined load and rotation speed, and the fatigue test is started. In this state, the rotational speed of the first drive shaft 11 obtained from the first drive generating means 12 with time and the rotational speed of the second drive shaft 21 obtained from the second drive generating means 22 with time. The load load over time detected by the number and the load load detection means 70 is correlated with time by the output means 90 by the control means 80, and the control operation panel of the test machine connected to the output means 90 and the evaluation By outputting the information to a terminal having an information storage function, an analysis function, or the like, the wear resistance and fatigue damage resistance of the rail in the straight section can be evaluated.

Next, in a state where the hand lever 27 is released and the angle changing plate 20 can be rotated with respect to the test machine base 10, the operator holds the angle change plate 20 with respect to the test machine base 10 at a predetermined angle. It is rotated by (for example, 0.1 rad unit) to give an attack angle θ.
The control means 80 receives information on the attack angle θ given by the operator by rotating the angle changing plate 20 with respect to the test machine base 10 from the attack angle detecting means 60.

  Next, the operator uses the input terminal connected to the control means 80 to test the rotational speed of the first drive shaft 11, the rotational speed of the second drive shaft 21, and the wheel 40 during rotational drive. By inputting a load load that is constant when the wheel 50 is brought into contact, the control means 80 drives the load load generating means 23 based on the inputted information, so that the wheel 40 and the test wheel 50 are predetermined. Contact with the applied load. Thereafter, the first drive generator 12 and the second drive generator 22 are driven. As a result, the peripheral surface of the rotating wheel 40 is brought into contact with the peripheral surface of the test wheel 50 rotating in the opposite direction to the wheel 40 with a predetermined load and rotation speed, and the fatigue test is started.

  In this state, the rotational speed of the first drive shaft 11 obtained from the first drive generating means 12 with time and the rotational speed of the second drive shaft 21 obtained from the second drive generating means 22 with time. The load load with time detected by the load load detection means 70 and the attack angle θ detected by the attack angle detection means 60 are related by the output means 90 by the control means 80 and connected to the output means 90. By being output to a terminal having a function for accumulating evaluation information and an analysis function, the wear resistance and fatigue damage resistance of the rail in the curved section can be evaluated.

  The control means 80, which has obtained information indicating a load load value different from the predetermined load load value from the load load detection means 70, tests the wheel 40 with respect to the load load generation means 23 based on the information. A command for adjusting the load applied to the wheel 50 is transmitted. Specifically, the load load generating means 23 that has received a command to adjust the load load of the test wheel 50 with respect to the wheel 40, the ball screw 23c based on the information regarding the load obtained from the load load detecting means 70 by the control means 80. Is driven. Then, the control means 80 performs feedback control on the load load generating means 23 based on the information on the load obtained from the load load detecting means 70. Specifically, while the control unit 80 receives the actual load load value from the load load detection unit 70 as needed, the load load until the load load value matches the predetermined load load value. Continue to issue commands to cause means 23 to adjust the load.

As described above, according to the present invention, the rail wear resistance and fatigue damage resistance tests in the straight section and the curved section are performed using test wheels having the same characteristics as the actually laid rail. The fatigue test apparatus can be provided without increasing the size.
In addition, the present invention is based on information obtained by reproducing the state of contact between the rail and the wheel when the rail is actually laid by applying an attack angle, and the rail laid in the straight section and the curved section. Wear resistance and fatigue damage resistance can be easily evaluated.
As mentioned above, although embodiment of this invention has been described, this invention is not limited to this, A various change and improvement can be performed.

DESCRIPTION OF SYMBOLS 1 Fatigue test apparatus 10 Test machine stand 11 1st drive shaft (for wheels)
12 1st drive generation means (for wheels)
13 Support hole 14 First lubricant supply means 20 Angle change plate 21 Second drive shaft (for test wheel)
22 Second drive generating means (for test wheels)
23 Load load generating means 24 Support block 25 Arm part 26 Second lubricant supply means 30 Support shaft 40 Wheel 50 Test wheel 60 Attack angle detecting means 61 Angle sensor 62 Distance sensor 70 Load load detecting means 80 Control means

Claims (5)

By attaching a cylindrical wheel and a cylindrical test wheel to a plurality of drive shafts that are independently driven to rotate, and pressing the wheel and the test wheel while rotating, the test wheel is worn and worn. A fatigue testing device for generating rolling fatigue damage,
A test machine table, and an angle changing plate coupled rotatably along the upper surface of the test machine table,
A first drive shaft having the wheel mounted thereon, and a first drive generating means for rotating the first drive shaft around its axial direction is provided in the test machine base;
A second drive shaft on which the test wheel is mounted, and a second drive generating means for rotating the second drive shaft around the axial direction is provided on the angle change plate;
Of the wheels and the test wheels that are rotated by the first drive shaft and the second drive shaft, a load load that contacts the peripheral surface of the test wheel with the peripheral surface of the wheel and applies a load to the test wheel Means are provided on the angle changing plate;
Attack angle detection means for detecting an attack angle formed by the axial direction of the second drive shaft with respect to the axial direction of the first drive shaft by rotating the angle changing plate along the upper surface of the test machine base; ,
A load detecting means for detecting a load of the test wheel with respect to the wheel;
Control means for controlling the load load means such that the load load detected by the load load detection means is constant;
Output that correlates with time the respective rotation speeds of the first drive shaft and the second drive shaft, the load load detected by the load load detection means, and the attack angle detected by the attack angle detection means And a fatigue testing apparatus.   The fatigue test apparatus according to claim 1, further comprising a lubricant supply unit configured to supply a lubricant to at least one of the wheel and the test wheel.   The fatigue test apparatus according to claim 1 or 2, wherein the diameter of the wheel and the test wheel is 50 mm or less.   The fatigue test apparatus according to claim 1, wherein the attack angle is greater than 0 (rad) and less than or equal to ± 3 (rad).   The fatigue test apparatus according to claim 1, wherein the test wheel is rail steel.

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