Strain gauges and load measuring devices

Abstract

To provide a strain gauge of a structure with which productivity is improved and measurement errors are reduced, as compared with strain gauges of prior art.SOLUTION: Provided is a strain gauge 10 comprising a tabular insulation base 11 and four grids G1, G2, G3, G4 provided on one surface of the insulation base 11. The four grids G1, G2, G3, G4 are arranged and pasted on one surface of the insulation base 11 in shape of the letter X so as not to overlap each other, the two grids G1, G3 out of the four grids G1, G2, G3, G4 being provided with a first inclined stripe pattern being folded and extending in a first diagonal direction with respect to the insulation base 11, the two other grids G2, G4 out of the four grids G1, G2, G3, G4 being provided with a second inclined stripe pattern being folded and extending in a second diagonal direction with respect to the insulation base 11, the second diagonal direction crossing the first diagonal direction at right angles.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a strain gauge and a load measuring device, and more particularly to a strain gauge that can be used to measure the wheel load or lateral force acting on the wheels of a railway vehicle from the rails of a railway track, and a load measuring device that measures the wheel load or lateral force. [Background technology]

[0002] Conventionally, in order to measure the wheel load (vertical load) and lateral force (horizontal load) acting on the wheels of a railway vehicle from the rails of a railway track, strain gauges are attached to the rails and the wheel load and lateral force are measured by detecting the distortion of the rail when a railway vehicle passes. For example, Patent Document 1 discloses a wheel load / lateral force measuring device that measures the wheel load / lateral force of the wheels of a railway vehicle by attaching strain gauges to the rails.

[0003] The wheel load / lateral force measuring device disclosed in Patent Document 1 comprises a plurality of strain gauges (biaxial strain gauges) that are affixed to the rails of a railway track and detect strain caused by the wheel load and lateral force acting on the rails, a plurality of friction contact type terminals to which the lead wires of the strain gauges are each detachably connected, a circuit board to which these terminals are attached and which configures the strain gauges into a Wheatstone bridge circuit, input / output lines connected to the circuit board and which supply a power supply voltage to the strain gauges and supply output from the Wheatstone bridge circuit to a measuring instrument, a waterproof casing that can be opened and closed to house the circuit board and cover the terminals so as to expose them for connection of the lead wires, and a waterproof inlet provided in the casing to allow the lead wires and the input / output wires to be freely inserted and removed into the casing.

[0004] When the wheel load / lateral force measuring device described in Patent Document 1 measures the wheel load, as shown in FIG. 10, four biaxial strain gauges 100 are attached at regular intervals on both sides of the rail web (bottom part) of the rail R that constitutes the railway track, and a sensor circuit is formed by bridge-joining the four biaxial strain gauges 100. In addition, the above-mentioned biaxial strain gauge 100 is configured such that the grids of the two uniaxial strain gauges 201 are overlapped and arranged so as to be perpendicular to each other, and when attached to a rail R, it is capable of detecting strain in the direction in which the rail R extends and strain in the direction in which the rail R contracts. Incidentally, a device for measuring the wheel load of a railway vehicle wheel by attaching a biaxial strain gauge, in which the grids of two uniaxial strain gauges are overlapped and arranged perpendicular to each other, to a rail is also disclosed in Patent Document 2, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-20322 A [Patent Document 1] JP 2002-202182 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, as shown in Fig. 11, the "biaxial strain gauge 100)" used in the above-mentioned conventional technology is constructed by preparing two "uniaxial strain gauges 201" formed by folding the grid of a non-inductive strain gauge 200 in half, and arranging the grids of the two "uniaxial strain gauges 201" so that they overlap each other orthogonally. In this way, by folding the grid in half, induced voltages are generated in the opposite directions, and induced noises are cancelled out.

[0007] However, the structure of the above-mentioned biaxial strain gauge 100 has a problem that productivity is low because it requires time-consuming steps such as folding the grid of the non-inductive strain gauge 200 in half and overlapping the two uniaxial strain gauges 201 formed by folding in half so that they are perpendicular to each other. Furthermore, it has been pointed out that the structure in which the grids of two strain gauges are overlapped, as in the above-mentioned biaxial strain gauge 100, is prone to measurement errors.

[0008] The present invention has been made in consideration of the above problems, and its object is to provide a strain gauge having a structure which improves productivity and reduces measurement errors compared to conventional techniques, and a load measuring device which is equipped with the strain gauge and measures wheel load or lateral force. [Means for solving the problem]

[0009] The present invention, which has been made to solve the above problems, is Rectangular in plan view A strain gauge having a plate-shaped insulating base and four grids provided on one surface of the insulating base, the four grids being attached to the one surface of the insulating base in an X-shape so as not to overlap each other. and four of the grids are connected on the insulating base to form a bridge circuit on the insulating base. The four grips D Two of the grids have a first oblique stripe pattern that extends in a first oblique direction relative to the insulating base, and the four grids D The other two grids include a second inclined stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction relative to the insulating base. Further, a power supply terminal and a measurement terminal are provided only on one side of the insulating base. It is characterized by the fact that

[0010] In this way, since the strain gauge of the present invention does not have a "structure in which the grid is folded in half and then overlapped" as in the conventional technology described above (see FIG. 11), the effect of improving productivity is obtained compared to the conventional technology. Furthermore, since the strain gauge of the present invention does not have a structure in which grids are superimposed, when the strain gauge is attached to the rail of a railway track and used to measure the wheel load or lateral force acting on the wheels of a railway vehicle from the rail, the possibility of measurement errors is reduced compared to the above-mentioned conventional technology (see FIG. 10). Furthermore, the strain gauge of the present invention has grids arranged in two perpendicular directions, so that, for example, when the strain gauge is attached to a rail, it can detect strain in the direction in which the rail expands and strain in the direction in which the rail contracts.

[0011] the above This configuration allows the device to be used immediately by simply connecting a power supply and measuring instruments to the strain gauge.

[0012] The present invention also provides a load measuring device for measuring a wheel load or a lateral force acting on a wheel of a railway vehicle from a rail of a railway track, the load measuring device comprising a plurality of strain gauges attached to the rail, a voltage supply source for supplying a power supply voltage to the plurality of strain gauges, and a measuring instrument for calculating the wheel load or the lateral force from a strain detected by a bridge circuit formed by connecting the plurality of strain gauges, each of the plurality of strain gauges being: Rectangular in plan view The strain gauge has a plate-shaped insulating base and four grids provided on one surface of the insulating base, and the four grids are attached to the one surface of the insulating base in an X-shape so as not to overlap each other. and four of the grids are connected on the insulating base to form a bridge circuit on the insulating base. The four grips D Two of the grids have a first oblique stripe pattern that extends in a first oblique direction relative to the insulating base, and the four grids D The other two grids among the grids have a second inclined stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction and turns back with respect to the insulating base. And, Furthermore, a power supply terminal and a measurement terminal are provided only on one side of the insulating base. It is characterized by the fact that

[0013] The present invention also provides a load measuring device for measuring a wheel load acting on a wheel of a railway vehicle from a rail of a railway track, the device comprising: four strain gauges attached to both sides of the rail along the extending direction of the rail; a voltage supply source for supplying a power supply voltage to the four strain gauges; and a measuring instrument for calculating the wheel load from strain detected by a bridge circuit formed by connecting the strain gauges; 4 The strain gauges of Rectangular in plan view The strain gauge has a plate-shaped insulating base and four grids provided on one surface of the insulating base, and the four grids are attached to the one surface of the insulating base in an X-shape so as not to overlap each other. and four of the grids are connected on the insulating base to form a bridge circuit on the insulating base. The four grips D Two of the grids are arranged in a first diagonal direction with respect to the insulating base. Direction a first inclined stripe pattern extending in a folded manner; D The other two grids among the grids have a second inclined stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction and turns back with respect to the insulating base. Further, a power supply terminal and a measurement terminal are provided only on one side of the insulating base. It is characterized by the fact that

[0014] In this way, according to the present invention, it is possible to provide a load measuring device for measuring wheel load or lateral force that reduces the possibility of measurement errors occurring, compared to the above-mentioned conventional technology (see FIG. 10). Effect of the Invention

[0015] According to the present invention, it is possible to provide a strain gauge having a structure that improves productivity and reduces measurement errors compared to the prior art. Also, according to the present invention, it is possible to provide a load measuring device that measures wheel load or lateral force, including the strain gauge. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing a configuration of a strain gauge according to an embodiment of the present invention; [Diagram 2] 1 is a schematic diagram for explaining a state in which a strain gauge is attached to a rail when a wheel load acting on a wheel of a railway vehicle is measured using a load measuring device according to an embodiment of the present invention; FIG. [Diagram 3] 1 is a schematic diagram showing an overall configuration of a load measuring device according to an embodiment of the present invention; [Figure 4] 1 is a schematic diagram showing a bridge circuit formed by four strain gauges of a load measuring device according to an embodiment of the present invention. [Diagram 5]1 is a schematic diagram for explaining a state in which a strain gauge is attached to a rail when a lateral force acting on a wheel of a railway vehicle is measured using a load measuring device according to an embodiment of the present invention; FIG. [Figure 6] FIG. 2 is a schematic diagram showing a configuration of a first modified example of a strain gauge according to an embodiment of the present invention. [Figure 7] FIG. 13 is a schematic diagram showing a configuration of a second modified example of the strain gauge according to the embodiment of the present invention. [Figure 8] FIG. 13 is a schematic diagram showing a configuration of a third modified example of the strain gauge according to the embodiment of the present invention. [Figure 9] FIG. 13 is a schematic diagram showing a configuration of a fourth modified example of the strain gauge according to the embodiment of the present invention. [Figure 10] FIG. 1 is a schematic diagram showing a strain gauge of a conventional railway vehicle wheel load / lateral force measuring device, in which the strain gauge is attached to a rail that constitutes a railway track. [Figure 11] FIG. 1 is a schematic diagram for explaining the structure of a strain gauge used in a conventional railway vehicle wheel load / lateral force measuring device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] <<Embodiment>> DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A strain gauge according to an embodiment of the present invention and a load measuring device for measuring a wheel load or a lateral force acting on a wheel of a railway vehicle from a rail of a railway track will be described below with reference to the drawings.

[0018] <Strain gauge 10> First, the configuration of a strain gauge 10 of this embodiment will be described with reference to FIG. Here, FIG. 1 is a schematic diagram showing the configuration of the strain gauge of this embodiment.

[0019] As shown in FIG. 1, the strain gauge 10 of this embodiment has a structure in which conductors (conductors such as grids G1, G2, G3, G4, etc.) are sandwiched between an insulating base (hereinafter simply referred to as "base") 11 made of synthetic resin or the like and an insulating cover (not shown) made of synthetic resin or the like.

[0020] Specifically, the strain gauge 10 has a base 11 that is rectangular (square in the illustrated example) in plan view, and four grids G1, G2, G3, and G4 provided on one surface of the base 11. The four grids G1, G2, G3, and G4 are attached to one surface of the base 11, arranged close to each other in an X shape so as not to overlap each other on the diagonal line of the base 11. A power supply terminal 12a, a measurement terminal 13a, a power supply terminal 12b, and a measurement terminal 13b are provided on one side of the one surface of the base 11 (the right side in the figure) in this order from the upper side (top side) to the lower side (bottom side).

[0021] The power supply terminal 12a is electrically connected to the grids G1 and G2, and the power supply terminal 12b is electrically connected to the grids G3 and G4. The measurement terminal 13a is electrically connected to the grids G2 and G3, and the measurement terminal 13b is electrically connected to the grids G1 and G4. Furthermore, alignment marks 15 are provided at the center of each of the four sides (upper side, lower side, right side, and left side) of the rectangular plate-like base 11.

[0022] The four grids G1, G2, G3, and G4 are resistors formed from metal foil such as a copper-nickel alloy, and each is formed in a rectangular shape (square in the illustrated example) in plan view. Furthermore, two of the four grids, G1 and G3, have an inclined stripe pattern that extends in a diagonal direction (for convenience of explanation, referred to as a "first diagonal direction") relative to the base 11 within a rectangular shape in a plan view. That is, the grid G1 and grid G3 form an inclined stripe pattern (first diagonal stripe pattern) in the same direction. In the illustrated example, the "first diagonal direction" is at the same angle (45 degrees) as the diagonal line L1 of the base 11. Furthermore, two of the four grids, G2 and G4, have an inclined stripe pattern (second inclined stripe pattern) that extends in a direction perpendicular to the "first inclined direction" (for convenience of explanation, "second inclined direction") relative to the base 11 within the rectangular shape in a plan view. That is, the grid G2 and the grid G4 form an inclined stripe pattern in the same direction. In this way, by configuring the strain gauge 10 with grids arranged in two perpendicular directions ("grids G1, G3" and "grids G2, 4"), for example, when the strain gauge 10 is attached to a rail R, it is possible to detect strain in the direction in which the rail R expands and strain in the direction in which the rail R contracts.

[0023] The grid G1 is disposed on the lower side of one surface of the base 11, at a position on one diagonal L1 of the base 11 such that its own diagonal coincides with the diagonal L1. The grid G2 is disposed on the upper side of one surface of the base 11 so that its diagonal line coincides with the other diagonal line L2 of the base 11. The grid G2 is disposed at a position spaced a predetermined distance above the grid G1. The grid G2 is also disposed at the same position in the left-right direction (X direction) as the grid G1.

[0024] The grid G3 is disposed on the upper side of one surface of the base 11 so that its diagonal line coincides with one diagonal line L1 of the base 11. The grid G3 is disposed at a position spaced a predetermined distance to the right of the grid G2. The grid G3 is also positioned in the same vertical direction (Y direction) as the grid G2. Grid G4 is disposed on the lower side of one surface of base 11 such that its diagonal line coincides with the other diagonal line L2 of base 11. Grid G4 is disposed at a position spaced a predetermined distance to the right of grid G1. Grid G4 coincides with grid G1 in the up-down direction (Y direction). Grid G4 coincides with grid G3 in the left-right direction (X direction).

[0025] Moreover, the four grids G1, G2, G3, and G4 are all electrically connected to each other, forming a bridge circuit on the base 11 of the strain gauge 10. Specifically, the grid G1 is connected to the grid G2 and also to the grid G4. Furthermore, the grid G3 is connected to the grid G2 and also to the grid G4. In this way, in the strain gauge 10, the four grids G1, G2, G3, and G4 are connected in an annular manner to form a circle.

[0026] With this configuration, the strain gauge 10 of this embodiment can be used immediately by connecting a power source or a measuring instrument to each terminal (power supply terminal 12a, measurement terminal 13a, power supply terminal 12b, measurement terminal 13b).

[0027] In addition, the strain gauge 10 of this embodiment does not have a "configuration in which the grid is folded in half and then overlapped" as in the conventional technology described above (see FIG. 11), so the advantageous effect of improving productivity is obtained compared to the conventional technology. Furthermore, since the strain gauge 10 of this embodiment is not configured to have overlapping grids, when used to measure, for example, the wheel load or lateral force acting on the wheels of a railway vehicle from the rails of a railway track, the possibility of measurement errors occurring is reduced compared to the above-mentioned conventional technology (see FIG. 10).

[0028] <Load measuring device W for measuring wheel load or lateral pressure> Next, a load measuring device W having the strain gauge 10 of this embodiment and for measuring a wheel load or a lateral force will be described with reference to FIG. 1 and FIGS. Here, Fig. 2 is a schematic diagram for explaining a state in which strain gauges are attached to a rail when the load acting on the wheels of a railway vehicle is measured using the load measuring device of this embodiment. Fig. 3 is a schematic diagram showing the overall configuration of the load measuring device of this embodiment. Fig. 4 is a schematic diagram showing a bridge circuit formed by four strain gauges of the load measuring device of this embodiment. In the example shown in Figs. 2 to 4, the load measuring device measures the wheel load acting on the wheels of a railway vehicle from the rail R of a railway track.

[0029] When using the load measuring device W of this embodiment to measure the wheel load acting on the wheels of a railway vehicle from the rail R of a railway track, four strain gauges 10 (10a, 10b, 10c, 10d) are affixed to both side surfaces of the web Ra of the rail R that constitutes the railway track and along the rail R, as shown in FIG. 2.

[0030] Specifically, strain gauge 10a is attached to position A on one surface of the upper portion Ra of rail R, and strain gauge 10b is attached to position B on one surface of the upper portion Ra of rail R, a predetermined distance L away from strain gauge 10a along the extension direction of rail R. Strain gauge 10b is attached in a position rotated 180 degrees with respect to strain gauge 10a. Also, a strain gauge 10d is attached to the other surface of the rail R at position D behind position A, and a strain gauge 10c is attached to the other surface of the rail R at position C (position C behind position B) a predetermined distance L away from the strain gauge 10d along the extension direction of the rail R. The strain gauge 10c is attached in a position rotated 180 degrees with respect to the strain gauge 10d.

[0031] That is, the strain gauge 10a and the strain gauge 10d are attached to the abdominal portion Ra of the rail R so as to face each other with the abdominal portion Ra of the rail R in between. Also, the strain gauge 10b and the strain gauge 10c are attached to the abdominal portion Ra of the rail R so as to face each other with the abdominal portion Ra of the rail R in between. The predetermined distance L is, for example, 50 to 100 cm.

[0032] Then, by connecting a control device 20 having a measuring instrument 21 and a voltage supply source 22 to each terminal (power supply terminal 12a, measurement terminal 13a, power supply terminal 12b, measurement terminal 13b) of four strain gauges 10 (10a, 10b, 10c, 10d) attached to the rail R, a load measuring device W that measures the wheel load of the railway vehicle of this embodiment is constructed.

[0033] Specifically, as shown in FIG. 3, the load measuring device W for measuring the wheel load of this embodiment includes four strain gauges 10a, 10b, 10c, and 10d affixed to both sides of the web portion Ra of a rail R constituting a railway track and along the rail R, and a control device 20 having a measuring instrument 21 and a voltage supply source 22.

[0034] 4, the four strain gauges 10 (10a, 10b, 10c, 10d) attached to the rail R are connected to form a bridge circuit. That is, in this embodiment, the 16-element grids G1, G2, G3, G4 of the four strain gauges 10 (10a, 10b, 10c, 10d) are connected in groups of four for each strain gauge 10 to form a bridge circuit, and the bridge circuits are connected in parallel.

[0035] The strain gauges 10a, 10b, 10c, and 10d in Fig. 3 are connected to form a bridge circuit in Fig. 4. Specifically, the grids G1, G2, G3, and G4 of the strain gauge 10a in Fig. 3 are connected to correspond to the symbols A1, A2, A3, and A4 in Fig. 4, the grids G1, G2, G3, and G4 of the strain gauge 10b in Fig. 3 are connected to correspond to the symbols B4, B3, B2, and B1 in Fig. 4, the grids G1, G2, G3, and G4 of the strain gauge 10c in Fig. 3 are connected to correspond to the symbols C1, C2, C3, and C4 in Fig. 4, and the grids G1, G2, G3, and G4 of the strain gauge 10d in Fig. 3 are connected to correspond to the symbols D4, D3, D2, and D1 in Fig. 4.

[0036] The measuring instrument 21 is also connected to the measurement terminals 13a and 13b of each strain gauge 10 (10a, 10b, 10c, and 10d) via signal lines s1 and s2. The measuring instrument 21 detects strain from a potential difference detected from a bridge circuit (see FIG. 4) consisting of grids G1, G2, G3, and G4 of 16 elements of the four strain gauges 10, and calculates the wheel load from the detected strain. Furthermore, the voltage supply source 22 is connected to the power supply terminals 12a, 12b of each strain gauge 10 (10a, 10b, 10c, 10d) via voltage supply lines s3, s4, and supplies a power supply voltage to each strain gauge 10 (10a, 10b, 10c, 10d).

[0037] The reason for this configuration is that the induced noises are cancelled out in the bridge circuit, and the same effect as the conventional technology can be obtained, without "folding the grid in two" as in the conventional technology (see FIG. 10). Therefore, according to this embodiment, the wheel load of a railway vehicle can be measured. In addition, the strain gauge 10 of this embodiment does not have a configuration in which the grid is folded in half and then overlapped, as in the conventional technology described above (see FIG. 11), and therefore the problems of low productivity and measurement errors associated with the conventional technology are eliminated.

[0038] <Example of measuring lateral pressure using load device W> Next, the installation position of the strain gauge 10 when measuring the lateral force acting on the wheels of a railway vehicle from the rail R of a railway track using the loading device W of this embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram for explaining a state in which a strain gauge is attached to a rail when the load measuring device of this embodiment is used to measure a lateral force acting on a wheel of a railway vehicle from a rail R of a railway track.

[0039] As shown in FIG. 5, four strain gauges 10 (10a, 10b, 10c, 10d) are affixed to the upper surface on both sides of the bottom portion Rb of the rail R that constitutes the railway track, and along the rail R (only strain gauges 10a and 10d are shown in the figure). Specifically, a strain gauge 10a is attached to a position on the upper surface of one side of the bottom part Ra of the rail R. In addition, a strain gauge 10b (not shown) is attached to a position on the upper surface of one side of the web part Ra of the rail R, at a predetermined distance L away from the strain gauge 10a along the extension direction of the rail R. A strain gauge 10d is attached to the other side of the top surface of the bottom portion Ra of the rail R at a position that is symmetrical to the attachment position of the strain gauge 10a with respect to the center line C of the rail cross section. A strain gauge 10c (not shown) is attached to the other side of the top surface of the bottom portion Ra of the rail R at a predetermined distance L away from the strain gauge 10d.

[0040] Then, as shown in FIG. 5, a measuring instrument 21 and a voltage supply 22 are connected to each terminal (power supply terminal 12a, measurement terminal 13a, power supply terminal 12b, measurement terminal 13b) of four strain gauges 10 (10a, 10b, 10c, 10d) attached to the rail R, thereby forming the load measuring device W shown in FIGS. 3 and 4. This enables the load measuring device W to measure the lateral force acting on the wheels of the railway vehicle from the rail R of the railway track. That is, the measuring instrument 21 detects strain from the potential difference detected from a bridge circuit (see FIG. 4) formed by the 16-element grids G1, G2, G3, G4 of the four strain gauges 10, and calculates the lateral force from the detected strain.

[0041] As described above, according to this embodiment, it is possible to provide a strain gauge 10 having a structure that improves productivity and reduces measurement errors compared to the conventional technology. Also, according to this embodiment, it is possible to provide a wheel load / lateral force measuring device W for railway vehicle wheels that reduces measurement errors compared to the conventional technology.

[0042] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention.

[0043] <Modification of strain gauge> For example, even if the above-described strain gauge 10 has the configurations of the modified examples shown in Figs. 6 to 9, the same effects as those of the above-described embodiment can be obtained. Here, Fig. 6 is a schematic diagram showing the configuration of a first modified strain gauge of this embodiment. Fig. 7 is a schematic diagram showing the configuration of a second modified strain gauge of this embodiment. Fig. 8 is a schematic diagram showing the configuration of a third modified strain gauge of this embodiment. Fig. 9 is a schematic diagram showing the configuration of a fourth modified strain gauge of this embodiment. 6 to 9, the strain gauges 110, 120, 130, and 140 are different from the strain gauge 10 of the above-mentioned embodiment in the arrangement of the grids or the shape of the grids, and the rest of the configuration is the same, so only the configuration necessary for the explanation is shown. Also, the same reference numerals are used for the same configuration as the strain gauge 10 of the above-mentioned embodiment.

[0044] In the first modified strain gauge 110 shown in FIG. 6, similarly to the embodiment described above, four grids G11, G12, G13, and G14 are attached to one side of a base 11 that is square in plan view, and are arranged closely to each other in an X shape on the diagonal of the base 11 so that they do not overlap each other. The grids G11, G12, G13, and G14 of this first modified example are formed in a square shape in a plan view, as in the above-described embodiment, and an inclined stripe pattern that extends obliquely relative to the base 11 is formed within the square.

[0045] However, in the strain gauge 110 of the first modified example, grids of inclined stripe patterns are arranged side by side in the same direction. Specifically, the grids G11 and 14 form an inclined stripe pattern that extends and turns back in the "first oblique direction" relative to the base 11, similar to the grids G1 and G3 of the strain gauge 10 of the above-described embodiment. Furthermore, like the grids G2 and G4 of the strain gauge 10 in the above-described embodiment, the grids G12 and 13 are formed in an inclined stripe pattern that extends in a "second diagonal direction" perpendicular to the "first diagonal direction" relative to the base 11.

[0046] The grid G11 is disposed on the lower side of one surface of the base 11 such that its diagonal coincides with one diagonal of the base 11. The grid G12 is disposed on the upper side of one surface of the base 11 such that its diagonal coincides with the other diagonal of the base 11. The grid G13 is disposed on the upper side of one surface of the base 11 such that its diagonal coincides with one diagonal of the base 11. The grid G14 is disposed on the lower side of one surface of the base 11 such that its diagonal coincides with the other diagonal of the base 11.

[0047] Similarly to the above-described embodiment, the strain gauge 110 of the first modified example is configured with grids arranged in two perpendicular directions ("grids G11, G14" and "grids G12, G13"). By attaching this strain gauge 110 to the rail R, it is possible to detect strain in the direction in which the rail R extends and strain in the direction in which the rail R contracts.

[0048] In addition, in the second modified example of strain gauge 120 shown in FIG. 7, similarly to the above-described embodiment, four grids G21, G22, G23, and G24 are attached to one side of base 11 which is square in plan view, and are arranged closely in an X shape on the diagonal of base 11 so as not to overlap each other. The grids G21, G22, G23, and G24 of this second modified example are formed in a square shape in a plan view, as in the above-described embodiment, and an inclined stripe pattern that extends obliquely relative to the base 11 is formed within the square.

[0049] However, the strain gauge 120 of the second modified example has a grid of inclined stripe patterns arranged vertically in the same direction. Specifically, the grids G21 and G22 form an inclined stripe pattern that extends in a "second oblique direction" relative to the base 11, similar to the grids G2 and G4 of the strain gauge 10 of the above-described embodiment. Furthermore, like the grids G1 and G3 of the strain gauge 10 in the above-described embodiment, the grids G23 and G24 are formed in an inclined stripe pattern that extends and folds back in a "first diagonal direction" perpendicular to the "second diagonal direction" relative to the base 11.

[0050] The grid G21 is disposed on the lower side of one surface of the base 11 such that its diagonal coincides with one diagonal of the base 11. The grid G22 is disposed on the upper side of one surface of the base 11 such that its diagonal coincides with the other diagonal of the base 11. The grid G23 is disposed on the upper side of one surface of the base 11 such that its diagonal coincides with one diagonal of the base 11. The grid G24 is disposed on the lower side of one surface of the base 11 such that its diagonal coincides with the other diagonal of the base 11.

[0051] And, in the strain gauge 210 of the second modified example, similarly to the above-described embodiment, grids are arranged in two perpendicular directions ("grids G21, G22" and "grids G23, G24"), and by attaching this strain gauge 210 to the rail R, it is possible to detect strain in the direction in which the rail R extends and strain in the direction in which the rail R contracts.

[0052] In addition, in the third modified example of the strain gauge 130 shown in FIG. 8, similarly to the above-described embodiment, four grids G31, G32, G33, and G34 are attached to one side of the base 11 which is square in plan view, and are arranged closely to each other in an X shape on the diagonal of the base 11 so as not to overlap each other. The grids G31, G32, G33, and G34 of this third modified example are formed into a rectangular shape in a plan view, rather than a square shape as in the above-described embodiment, and one of the short sides is disposed toward the center of the base 11.

[0053] Furthermore, two of the four grids, G31 and G33, are formed with an inclined stripe pattern that extends in a "first oblique direction" relative to the base 11 within a rectangle in a plan view. That is, the grids G31 and G33 form an inclined stripe pattern in the same direction. Furthermore, two of the four grids, G32 and G34, are formed with an inclined stripe pattern that extends in a "second diagonal direction" perpendicular to the "first diagonal direction" and turns back with respect to the base 11 within a rectangle in a plan view. That is, the grids G32 and G34 form an inclined stripe pattern in the same direction.

[0054] The grid G31 is disposed below one surface of the base 11 such that its center line in the short side direction coincides with one diagonal position of the base 11. The grid G32 is disposed above one surface of the base 11 such that its center line in the short side direction coincides with the other diagonal position of the base 11. The grid G33 is disposed above one surface of the base 11 such that its center line in the short side direction coincides with one diagonal position of the base 11. The grid G34 is disposed below one surface of the base 11 such that its center line in the short side direction coincides with the other diagonal position of the base 11.

[0055] And, in the third modified strain gauge 140, as in the above-described embodiment, grids are arranged in two perpendicular directions ("grids G31, G33" and "grids G32, G34"), and by attaching this strain gauge 310 to the rail R, it is possible to detect strain in the direction in which the rail R extends and strain in the direction in which the rail R contracts.

[0056] In addition, in the fourth modified example of strain gauge 140 shown in FIG. 9, similarly to the above-described embodiment, four grids G41, G42, G43, and G44 are attached to one side of a base 11 that is square in plan view, and are arranged closely to each other in an X shape on the diagonal of the base 11 so that they do not overlap each other. The grids G41, G42, G43, and G44 of this fourth modified example are formed as elongated hexagons in a planar view, rather than squares as in the above-described embodiment, and one of the longitudinal vertices is positioned toward the center of the base 11.

[0057] In the strain gauge 140 of the fourth modification, two of the four grids, G41 and G43, are formed in an oblique stripe pattern that extends in a "first oblique direction" relative to the base 11 within an elongated hexagon in a plan view. That is, the grids G41 and G43 form an oblique stripe pattern in the same direction. Furthermore, two of the four grids, G42 and G44, are formed in an oblique stripe pattern that extends in a "second oblique direction" perpendicular to the "first oblique direction" and turns back with respect to the base 11 within an elongated hexagon in a plan view. That is, the grids G42 and G44 form oblique stripe patterns in the same direction.

[0058] The grid G41 is disposed on the lower side of one surface of the base 11 such that its diagonal in the longitudinal direction coincides with one diagonal of the base 11. The grid G42 is disposed on the upper side of one surface of the base 11 such that its diagonal in the longitudinal direction coincides with the other diagonal of the base 11. The grid G43 is disposed on the upper side of one surface of the base 11 such that its diagonal in the longitudinal direction coincides with one diagonal of the base 11. The grid G44 is disposed on the lower side of one surface of the base 11 such that its diagonal in the longitudinal direction coincides with the other diagonal of the base 11.

[0059] And, in the fourth modified strain gauge 140, as in the above-described embodiment, grids are arranged in two perpendicular directions ("grids G41, G43" and "grids G42, G44"), and by attaching this strain gauge 410 to the rail R, it is possible to detect strain in the direction in which the rail R extends and strain in the direction in which the rail R contracts.

[0060] In this way, the first to fourth modified examples shown in Figures 6 to 9 do not have a configuration in which the grid is folded in half and then overlapped as in the conventional technology, so the problems with productivity and measurement errors that are present in the conventional technology are resolved.

[0061] In the above-described embodiment and modified examples, the strain gauges 10, 110, 120, 130, and 140 are used to detect the wheel load and lateral force of a railway vehicle, but the present invention is not limited to this. The strain gauges can also be used for purposes other than detecting the wheel load and lateral force of a railway vehicle.

[0062] In addition, in the above-described embodiment and modified examples, the base 11 is formed in a square shape, but this is merely an example. The shape of the base 11 can be designed as appropriate. In addition, in the above-described embodiment and modified examples, the grids (G1 to 4, G11 to 14, G21 to 24, G31 to 34, G41 to 44) are all formed in a polygonal shape, but this is merely one example, and the shape of the grid can be designed as appropriate. [Explanation of symbols]

[0063] 10 (10a, 10b, 10c, 10d)...Strain gauge G1, G2, G3, G4...Grid 11...Base (insulating base) 12a, 12b…power terminal 13a, 13b...Measurement terminals 15…Alignment mark 20...Control device 21...Measuring instrument 22...Voltage supply source s1, s2...signal line s3, s4...Voltage supply lines R…Rail Ra…Abdomen Rb…bottom 110...Strain gauge G11, G12, G13, G14...Grid 120...Strain gauge G21, G22, G23, G24...Grid 130...Strain gauge G31, G32, G33, G34...Grid 140...Strain gauge G41, G42, G43, G44…Grid

Claims

1. A strain gauge having an insulating base having a rectangular plate shape in a plan view and four grids provided on one side of the insulating base, the four grids are attached to one surface of the insulating base in an X-shape so as not to overlap one another, and the four grids are connected on the insulating base to form a bridge circuit on the insulating base; Two of the four grids include a first oblique stripe pattern extending in a first oblique direction relative to the insulating base; the other two grids of the four grids have a second inclined stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction relative to the insulating base, The strain gauge further comprises a power supply terminal and a measurement terminal provided on only one side of the insulating base.

2. A load measuring device for measuring wheel load or lateral force acting on a wheel of a railway vehicle from a rail of a railway track, A plurality of strain gauges attached to the rail; a voltage supply source that supplies a power supply voltage to the plurality of strain gauges; a measuring instrument for calculating a wheel load or a lateral force from a strain detected by a bridge circuit formed by connecting a plurality of the strain gauges; Each of the plurality of strain gauges has an insulating base having a rectangular plate shape in a plan view and four grids provided on one surface of the insulating base, The strain gauge has four grids attached to one surface of the insulating base in an X-shape so as not to overlap one another, and the four grids are connected on the insulating base to form a bridge circuit on the insulating base, two of the four grids have a first oblique stripe pattern that extends in a first oblique direction relative to the insulating base, and the other two of the four grids have a second oblique stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction relative to the insulating base, The load measuring device is further characterized in that a power supply terminal and a measurement terminal are provided on only one side of the insulating base.

3. A load measuring device for measuring a wheel load acting on a wheel of a railway vehicle from a rail of a railway track, Four strain gauges are attached to both side surfaces of the rail along the extending direction of the rail; A voltage supply source that supplies a power supply voltage to the four strain gauges; a measuring instrument for calculating a wheel load from a strain detected by a bridge circuit formed by connecting the strain gauges; Each of the four strain gauges has an insulating base having a rectangular plate shape in a plan view and four grids provided on one surface of the insulating base, The strain gauge has four grids attached to one surface of the insulating base in an X-shape so as not to overlap one another, and the four grids are connected on the insulating base to form a bridge circuit on the insulating base, two of the four grids have a first oblique stripe pattern that extends in a first oblique direction relative to the insulating base, and the other two of the four grids have a second oblique stripe pattern that extends in a second oblique direction perpendicular to the first oblique direction relative to the insulating base, The load measuring device is further characterized in that a power supply terminal and a measurement terminal are provided on only one side of the insulating base.

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