JP2018059881A - Measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring device capable of measuring three-component force and six-component force regarding grounding force of a tire with very high accuracy.SOLUTION: A measuring unit 14 of a tire testing device 10 includes: a base 24; a plate 22 arranged away from the base 24; and a plurality of sensors 26 for measuring loads on the plate 22. A sensor 26X has an X direction as a measuring direction, and freely slides in a Y direction relative to the base 24 or the plate 22. A sensor 26Y has the Y direction as a measuring direction, and freely slides in the X direction relative to the base 24 or the plate 22.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a measuring device, and more particularly, to a measuring device that measures a multiplicity of force with respect to a ground contact force of a tire.

  In recent years, attempts have been made to accurately grasp the load (contact force) applied to the tire of a traveling vehicle. For example, in Patent Document 1, a sensor unit in which a gauge is attached to a pillar member is embedded in a road surface, and a load when a tire passes through the sensor unit can be measured three-dimensionally. A plurality of sensor units are arranged in a line in a direction orthogonal to the traveling direction of the tire, and a load applied to the tire can be measured at a plurality of locations in the width direction of the tire.

  By the way, the measuring apparatus of patent document 1 measures the ground contact force of a tire locally (namely, pinpoint). On the other hand, there is a demand to accurately measure the ground contact force of the entire tire.

  As a configuration of the device for measuring the contact force of the entire tire, for example, a plate larger than the contact area of the tire is prepared, and the plate is horizontally disposed above the base, and a plurality of loads are provided between the base and the plate. It is conceivable to provide a sensor and connect the two with the sensor. If such an apparatus is used, when the tire passes on the plate, the load exerted on the plate by the tire can be measured by the sensor.

JP 2000-162054

  However, when the test was performed using the above-described apparatus, there was a problem in that the data might vary, and it was difficult to accurately determine the ground contact force. In particular, when the plate is placed outdoors, there is a problem that the data becomes unstable and the accuracy tends to decrease.

  Conventionally, high accuracy was not required for measuring the ground contact force of the entire tire, and such a problem was not noticed. However, recently, simulations are frequently used in the design and development stages, and advanced analysis based on measurement values is required. Therefore, measurement data also requires high accuracy.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a measuring device that can measure the force of the tire contact force with very high accuracy.

  In order to achieve the above object, the invention according to claim 1 includes a base, a plate arranged apart from the base, and a plurality of sensors for measuring a load applied to the plate. At least one of the measurement devices is characterized in that the measurement direction is parallel to the plate and is slidable with respect to the base or the plate in a direction perpendicular to the measurement direction.

  In order to achieve the above object, a second aspect of the present invention includes a base, a plate that is spaced apart from the base, and a plurality of sensors that measure a load applied to the plate. Includes two types of sensors whose measurement directions are perpendicular to each other and parallel to the plate, and the two types of sensors are slidable in a direction perpendicular to their own measurement direction with respect to the base or the plate, respectively. Provided is a measuring device characterized by

  The inventor of the present invention paid attention to the temperature change of the measurement environment as a factor that makes the measurement value unstable. Then, when the plate thermally expands or contracts due to a temperature change, the sensor fixed between the plate and the base is stressed, resulting in an adverse effect on the measured value.

  The present invention has been made based on such an idea. Since the sensor is slidable in a direction perpendicular to the measurement direction with respect to one of the plate and the base, the sensor can be operated when the plate is thermally expanded or contracted. Slide to prevent sensor deformation. Further, since the sensor measures in a direction orthogonal to the sliding direction, the measurement accuracy does not decrease even if it slides, and it can be measured accurately. Therefore, according to the present invention, even when the plate is thermally expanded / contracted, stable measurement data can be obtained, and 3-component force and 6-component force can be obtained correctly.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a guide by a groove or a protrusion is formed in the plate or the base, and the sensor is slidably engaged with the guide. And

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the sensor that is slidable on the base or the plate has the same measurement direction on both sides of the center of the plate. It is characterized by being. According to the present invention, since the sensors are arranged on both sides of the central portion of the plate, the sensor is easily slid when the plate is expanded and contracted, and the sliding amount is reduced. Therefore, the influence by the slide can be suppressed as much as possible.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the plurality of sensors include sensors whose measurement direction is a direction orthogonal to the plate. According to the present invention, it is possible to measure in a direction orthogonal to the plate. For example, when the plate is arranged horizontally, the vertical load applied to the plate can be measured.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the plate is formed in a rectangular shape larger than a ground contact surface of a tire that is an object to be measured and is disposed horizontally. According to the present invention, the load exerted on the plate by the tire can be measured.

  According to the present invention, since the sensor is slidable with respect to the plate or the base, deformation of the sensor can be prevented even when the plate is thermally expanded or contracted, and accurate measurement can be performed.

The figure which shows typically the structure of the tire test apparatus to which this invention was applied. Perspective view showing the measurement unit The figure which shows the horizontal section of the measurement section Perspective view showing sensor for X direction measurement The perspective view which shows the sensor for Y direction measurement The figure which shows the state where the measurement part was embedded in the road surface Diagram explaining the measurement principle Explanatory drawing explaining the situation where trouble occurs in the measurement unit of the comparative example Explanatory drawing explaining the effect | action of this embodiment Sectional drawing which shows the measurement part of other embodiment

  Hereinafter, a preferred embodiment of a measuring device according to the present invention will be described with an example applied to a tire testing device.

  FIG. 1 schematically shows the configuration of the tire testing apparatus 10. The tire test apparatus 10 shown in the figure includes a measurement unit 14 that measures the contact force of the tire 12 and a control unit 16 that performs various arithmetic processes from the measurement values of the measurement unit 14. The control unit 16 includes an amplifier, an AD converter, an arithmetic circuit, a memory, and the like. The control unit 16 amplifies the signal from the measurement unit 14, performs AD conversion, performs various signal processing, and stores the signal. Configured. A display 18 is connected to the control unit 16, and a calculation result or the like is displayed on the display 18.

  FIG. 2 is a perspective view illustrating a schematic configuration of the measurement unit 14, and FIG. 3 is a cross-sectional view of the measurement unit 14 on a horizontal plane. In these drawings, the X direction indicates the traveling direction (horizontal direction) of the tire 12, the Y direction indicates the width direction (horizontal direction) of the tire 12, and the Z direction indicates the vertical direction.

  The measuring unit 14 is disposed at a position through which the vehicle tire 12 passes, and mainly includes a plate 22, a base 24, and a sensor 26. The plate 22 and the base 24 are formed in a rectangular shape having substantially the same size from a metal, for example, aluminum, and are arranged at intervals in the vertical direction. Between the plate 22 and the base 24, eight sensors 26 for measuring the load on the plate 22 are provided. The sensor 26 is configured to measure any one of the X direction, the Y direction, and the Z direction. Here, the sensor 26 that measures the X direction is referred to as sensor 26X, the sensor 26 that measures the Y direction is referred to as sensor 26Y, and the sensor 26 that measures the Z direction is referred to as sensor 26Z. Two sensors 26X and 26Y are provided, and four sensors 26Z are provided.

  As shown in FIG. 3, the sensor 26 </ b> X is disposed on a straight line in the Y direction that passes through the center of the base 24 (that is, the center of the plate 24). The sensor 26X is disposed on both sides of the center portion of the base 24 and on the peripheral portion of the base 24 (that is, the peripheral portion of the plate 22). As the sensor 26X, for example, a bending strain gauge type load cell shown in FIG. 4 is used. The sensor 26 </ b> X includes a strain body 28 </ b> X formed of metal or the like, the upper end of the strain body 28 </ b> X is connected to the plate 22 (see FIG. 2), and the lower end of the strain body 28 </ b> X is the groove 24 </ b> X of the base 24. Is engaged. The groove 24X of the base 24 is formed in the Y direction on the upper surface of the base 24, and the lower end of the strain generating body 28X enters the groove 24X. Further, the groove 24X is formed with such a depth that a slight gap is formed below the strain body 28X. Further, the groove 24X is formed with the same width as the lower end of the strain body 28X, and the lower portion of the strain body 28X and the base 24 move together in the X direction. A hole 32X penetrating in the Y direction is formed in the strain body 28X, thin portions are formed at four locations, and a gauge 30X is attached to the thin portion. The gauge 30X is connected so as to form a bridge circuit, and is further connected to the control unit 16 (see FIG. 1). According to the sensor 26X configured as described above, when the plate 22 receives a load in the X direction, the thin portion of the strain generating body 28X is deformed, and the electric resistance of the gauge 30X changes, so that the load in the X direction is increased. It can be measured. Further, according to the sensor 26X, the upper end is coupled to the plate 22, while the lower end is slidable in the Y direction along the groove 24X of the base 24. Therefore, when the plate 22 expands or contracts in the Y direction, the sensor 26X Can move in the Y direction with the plate 22.

  As shown in FIG. 3, the sensor 26 </ b> Y is disposed on a straight line in the X direction that passes through the central portion of the base 24. Further, the sensor 26 </ b> Y is disposed on both sides of the center portion of the base 24 and in the peripheral portion of the base 24. The sensor 26Y uses a bending type strain gauge type load cell similarly to the sensor 26X. As shown in FIG. 5, the sensor 26 </ b> Y includes a strain body 28 </ b> Y formed in a columnar shape, the upper end of which is connected to the plate 22 (see FIG. 2), and the lower end is engaged with the groove 24 </ b> Y of the base 24. Yes. The groove 24Y of the base 24 is formed in the X direction on the upper surface of the base 24, and the lower end of the strain generating body 28Y enters the groove 24Y. The groove 24Y is formed with such a depth that a slight gap is formed below the strain body 28Y. Further, the groove 24Y is formed with the same width as the lower end of the strain body 28Y, and the lower portion of the strain body 28Y and the base 24 move together in the Y direction. A hole 32Y penetrating in the X direction is formed in the strain body 28Y, thin portions are formed at four locations, and a gauge 30Y is attached to the thin portion. The gauge 30Y is connected so as to form a bridge circuit, and is further connected to the control unit 16 (see FIG. 1). According to the sensor 26Y configured as described above, when the plate 22 receives a load in the Y direction, the thin portion of the strain generating body 28Y is deformed, and the electric resistance of the gauge 30Y changes, thereby changing the load in the Y direction. It can be measured. According to the sensor 26Y, the upper end is coupled to the plate 22, while the lower end is slidable in the X direction along the groove 24Y of the base 24. Therefore, when the plate 22 expands or contracts in the X direction, the sensor 26Y Can move in the X direction with the plate 22.

  As shown in FIGS. 2 and 3, the sensor 26 </ b> Z is disposed at the four corners of the plate 22 (that is, the four corners of the base 24). However, since the lower end of the sensor 26Z may slightly move on the surface of the base 24 as will be described later, it is preferable to arrange the sensor 26Z so as to have a slight gap from each edge of the base 24. As the sensor 26Z, for example, a compression type strain gauge type load cell is used. Although the configuration is not shown, it is composed of a columnar strain body made of metal or the like and a plurality of gauges attached to the side surface. The upper end of the strain generating body is connected to the lower surface of the plate 22, and the lower end of the strain generating body is placed on the base 24 (not connected to the base 24). Therefore, the lower end of the sensor 26Z can freely move on the surface of the base 24. The gauge is connected so as to form a bridge circuit, and is further connected to the control unit 16 (see FIG. 1). According to the sensor 26Z configured as described above, when a load in the Z direction is applied to the plate 22, the strain generating body is compressed and the electrical resistance of the gauge changes, so that the load can be measured. Further, according to the sensor 26Z, the lower end of the strain generating body freely moves on the surface of the base 24. Therefore, when the plate 22 expands or contracts in the X direction or the Y direction, it can move with the plate 22. .

  A lubricant such as grease is preferably applied to the sliding portion between the above-described sensors 26X, 26Y, and 26Z and the base 24. Specifically, the sliding portion between the strain body 28X of the sensor 26X and the groove 24X of the base 24, the sliding portion between the strain body 28Y of the sensor 26Y and the groove 24Y of the base 24, and the strain body of the sensor 26Z. A lubricant may be applied to a sliding portion between the lower surface of 28 and the upper surface of the base 24. Thereby, both frictional resistance can be reduced.

  As shown in FIG. 6, the measurement unit 14 configured as described above is disposed in the recess 36 </ b> A of the road surface 36. The recess 36A of the road surface 36 is formed slightly larger than the plate 22 so that the plate 22 does not contact the wall surface of the recess 36A. Further, the depth of the recess 36 </ b> A matches the height of the measuring unit 14, and the upper surface of the plate 22 and the road surface 36 are flush with each other. Therefore, the tire 12 that has rolled on the road surface 36 moves on the plate 22 as it is, rolls on the plate 22, and then moves on the road surface 36 again. At that time, the contact force exerted on the plate 22 by the tire 12 is measured by the sensor 26. Specifically, the load in the X direction is measured by the sensor 26X, the load in the Y direction is measured by the sensor 26Y, and the load in the Z direction is measured by the sensor 26Z.

  FIG. 7 is a diagram for explaining the measurement principle. FIG. 7A shows a no-load state, and FIG. 7B exaggerates a state in which a load is applied in the X direction. These drawings schematically show a front view of the measurement unit 14, and a part of the right side shows a cross section at the position of the sensor 26Y.

  As shown in FIG. 7B, when a load in the X direction is applied to the plate 22, the plate 22 is slightly displaced in the X direction. Since the sensor 26X has an upper end coupled to the plate 22 and a lower end engaged with the groove 24X of the base 24 without any gap in the X direction, the position of the upper and lower ends of the sensor 26X when the plate 22 is displaced in the X direction. Shifts in the X direction and deforms. On the other hand, since the lower end of the sensor 26Y can freely move in the X direction along the groove 24Y, the entire sensor 26Y moves in the X direction and is not deformed. Further, since the sensor 26Z can move freely in the X direction only by placing the lower end on the base 24, the entire sensor 26Z moves in the X direction and is not deformed. Therefore, when a load in the X direction is applied to the plate 22, only the sensor 26X is deformed, and the load in the X direction can be accurately measured by the sensor 26X.

  Similarly, when a load in the Y direction is applied to the plate 22, the plate 22 is slightly displaced in the Y direction. The sensor 26Y has an upper end connected to the plate 22 and a lower end engaged with the groove 24Y of the base 24 with no gap in the Y direction. Therefore, when the plate 22 is displaced in the Y direction, the positions of the upper and lower ends of the sensor 26Y are Shifts in the Y direction and deforms. On the other hand, since the lower end of the sensor 26X can freely move in the Y direction along the groove 24X, the entire sensor 26X moves in the Y direction and is not deformed. Further, since the sensor 26Z can move freely in the Y direction only by placing the lower end on the base 24, the entire sensor 26Z moves in the Y direction and is not deformed. Therefore, when a load in the Y direction is applied to the plate 22, only the sensor 26Y is deformed, and the load in the Y direction can be accurately measured by the sensor 26Y.

  On the other hand, when a load in the Z direction is applied to the plate 22, the sensor 26Z is compressed in the Z direction and deformed. In contrast, the sensors 26X and 26Y are not compressed and do not deform because there is a slight gap below them. Therefore, when a load in the Z direction is applied to the plate 22, only the sensor 26Z is deformed, and the load in the Z direction can be accurately measured by the sensor 26Z.

  Thus, among the loads received by the plate 22, the X direction component is measured by the sensor 26X, the Y direction component is measured by the sensor 26Y, and the Z component is measured by the sensor 26Z. The sensors 26 </ b> X, 26 </ b> Y, and 26 </ b> Z are connected to the control unit 16, and measurement data is transmitted to the control unit 16. The control unit 16 calculates three component forces (X direction component, Y direction component, and Z direction component) of the ground contact force from the measurement data, and displays the result on the display 18. Moreover, the control part 16 calculates | requires the gravity center track | orbit of the tire 12 from the measurement data of four sensors 26Z as needed, and displays the result on the indicator 18. Further, the control unit 16 obtains six component forces (X direction component, Y direction component, Z direction component, moment about the X axis, moment about the Y axis, moment about the Z axis) as necessary, and results thereof. Is displayed on the display 18. At this time, the moment may be obtained with respect to the center of the plate 22 or may be corrected to a moment at other points.

  Next, the operation of the tire testing apparatus 10 configured as described above will be described. The above-described measuring unit 14 may be installed outdoors, and the plate 22 may be exposed to direct sunlight or cold air to thermally expand or contract. In the case of “a structure in which the plate 22 is connected to the base 24 at a plurality of locations” (that is, a structure different from the present invention), if the plate 22 is thermally expanded / contracted, it causes a measurement error. The situation will be described with reference to FIG.

  FIG. 8 schematically shows a measurement unit of a comparative example. In the measuring unit, a plurality of sensors 27 are provided between the plate 22 and the base 24, and the upper end of the sensor 27 is fixed to the plate 22 and the lower end is fixed to the base 24.

  FIG. 8A shows a state before expansion, and FIG. 8B exaggerates the state where the plate 22 has expanded in the X direction. As shown in these drawings, when the plate 22 is thermally expanded in the X direction, the upper end of the sensor 27 is pulled by the plate 22 and displaced outward. On the other hand, since the lower end of the sensor 27 is fixed to the base 24 and is not displaced, the sensor 27 is deformed. As a result, the resistance of the gauge of the sensor 27 changes, resulting in a measurement error.

  On the other hand, in the measurement unit 14 according to the present embodiment, the sensors 26X, 26Y, and 26Z are fixed only to the plate 22 and are not fixed to the base 24. It is possible to prevent the sensors 26X, 26Y, and 26Z from being deformed. The situation will be described with reference to FIG.

  FIG. 9 schematically shows the situation of the present embodiment. FIG. 9A shows a state before expansion, and FIG. 9B exaggerates the state where the plate 22 has expanded in the X direction. These drawings schematically show a front view of the measuring unit 14, and a part of the right side shows a cross section at the position of the sensor 26Y.

  When the plate 22 expands in the X direction, the upper ends of the sensors 26Y and 26Z are connected to the plate 22 and thus move outward (in the X direction) together with the plate 22. At that time, since the lower end of the sensor 26Y can move in the X direction along the groove 24Y of the base 24, it moves outward together with the upper end. Accordingly, since the entire sensor 26Y moves in the X direction, the sensor 26Y is not deformed. Further, since the lower end of the sensor 26Z can freely move on the XY plane with respect to the base 24, it moves outward together with the upper end. Therefore, the entire sensor 26Z moves in the X direction, and the sensor 26Z is not deformed. Thus, even when the plate 22 is expanded in the X direction, the sensors 26Y and 26Z are not deformed, and the occurrence of measurement errors can be suppressed. Similarly, when the plate 22 contracts, the sensors 26Y and 26Z are not deformed, so that generation of measurement errors can be suppressed.

  When the plate 22 expands or contracts in the Y direction, the upper ends of the sensors 26X and 26Z move together with the plate 22 in the Y direction. At that time, the lower end of the sensor 26X moves in the Y direction along the groove 24X of the base 24, and the lower end of the sensor 26Z slides on the upper surface of the base 24 and moves in the Y direction. Therefore, even if the plate 22 expands or contracts in the Y direction, the sensors 26X and 26Z are not deformed, and the occurrence of measurement errors can be suppressed.

  As described above, according to the present embodiment, since the sensors 26X, 26Y, and 26Z are not fixed to the base 24, even if the plate 22 expands and contracts on the XY plane, the sensors 26X and 26Y. , 26Z can be prevented from being deformed. Therefore, the occurrence of errors due to thermal expansion and contraction of the plate 22 can be prevented, so that the three-component force of the grounding force can be accurately measured. Furthermore, it is possible to accurately determine 6 component forces that are more affected by errors than 3 component forces.

  Further, according to the present embodiment, the sensors 26X and 26Y are arranged one on each side with the central portion of the plate 22 in between. Thus, by arranging the sensor 26X and the sensor 26Y evenly with respect to the center portion of the plate 22, when the plate 22 is thermally expanded or contracted, the plate 22 is likely to expand evenly on both sides. The influence of heat shrinkage can be reduced as much as possible.

  In the above-described embodiment, the grooves 24X and 24Y are formed in the base 24 to engage the sensors 26X and 26Y. However, the present invention is not limited to the grooves 24X and 24Y, and the sensors 26X and 26Y are arranged in a predetermined direction. Any means may be used as long as it guides. Therefore, for example, a guide may be formed by providing a protrusion on the upper surface of the base 24, or a linear guide using a roller, a bearing, or the like may be used.

  In the above-described embodiment, one sensor 26X, 26Y is arranged on each side of the central portion of the plate 22. However, the number and arrangement of the sensors 26X, 26Y are not limited to this, and the sensor 26X or sensor 26Y is not limited thereto. Only one plate may be provided at the center of the plate 22 or three or more may be provided in total.

  In the above-described embodiment, the lower end of the sensor 26Z is placed on the base 24. However, the present invention is not limited to this, and the lower end of the sensor 26Z is movable on the XY plane and engages in the Z direction. Various configurations may be applied.

  Moreover, although embodiment mentioned above used three types of sensors 26X, 26Y, and 26Z whose measurement direction is only one direction, it is not limited to this and various aspects are possible. For example, FIG. 10 shows an example using two types of sensors 26XZ and 26YZ that measure in two directions. The sensor 26XZ is a sensor that performs measurement in the X direction and the Z direction. The configuration and arrangement of the sensor 26XZ are substantially the same as those of the sensor 26X described above, but the lower surface of the sensor 26XZ is in contact with the bottom surface of the groove 24X. It has a gauge to measure the compression of the. The sensor 26YZ is a sensor that performs measurement in the Y direction and the Z direction. The configuration and arrangement of the sensor 26YZ are substantially the same as those of the sensor 26Y described above, but the lower surface of the sensor 26YZ is in contact with the bottom surface of the groove 24Y. It has a gauge to measure the compression of the. Even in such a configuration, since the sensor 26XZ is slidable in the Y direction and the sensor 26YZ is slidable in the X direction, the sensors 26XZ and 26YZ are deformed when the plate 22 is expanded or contracted. Can be prevented. In the present invention, it is sufficient that at least one of the plurality of sensors 26 is slidable in the direction orthogonal to the measurement direction with respect to the plate 22 or the base 24, thereby measuring errors due to expansion and contraction of the plate 22. Can be suppressed.

  In the above-described embodiment, the sensors 26X, 26Y, and 26Z are fixed to the plate 22 to be movable with respect to the base 24. Conversely, the sensors 26X, 26Y, and 26Z may be movable with respect to the plate 22 by being fixed to the base 24. .

  Furthermore, although embodiment mentioned above is an example of the apparatus which measures the contact force in the whole tire 12, you may make it measure simultaneously by incorporating the sensor which measures the local contact force of the tire 12 in the plate 22. FIG. .

  In addition, although embodiment mentioned above is an example which applied this invention to the tire test apparatus 10, this invention is not limited to this, It can use for various uses. For example, the present invention can be applied as a device that measures the surface pressure of a foot when a person walks or runs, or can be applied as a device that measures 3 or 6 component forces at a connecting portion of an industrial machine. Moreover, it is not limited to the use which arrange | positions the plate 22 horizontally, It can apply also to the use arrange | positioned vertically or diagonally.

  DESCRIPTION OF SYMBOLS 10 ... Tire test apparatus, 12 ... Tire, 14 ... Measurement part, 16 ... Control part, 18 ... Display, 22 ... Plate, 24 ... Base, 26 ... Sensor, 28 ... Strain body, 30 ... Gauge, 32 ... Hole , 36 ... road surface

Claims (6)

A base, a plate disposed apart from the base, and a plurality of sensors for measuring a load applied to the plate;
At least one of the plurality of sensors has a measurement direction parallel to the plate and is slidable with respect to the base or the plate in a direction perpendicular to the measurement direction. A base, a plate disposed apart from the base, and a plurality of sensors for measuring a load applied to the plate;
The plurality of sensors includes two types of sensors whose measurement directions are orthogonal to each other and parallel to the plate,
The two types of sensors are slidable in a direction perpendicular to their own measuring direction with respect to the base or the plate, respectively.   The measuring device according to claim 1, wherein a guide by a groove or a protrusion is formed on the plate or the base, and the sensor is slidably engaged with the guide.   4. The sensor according to claim 1, wherein sensors that are slidable on the base or the plate have the same measurement direction on both sides of the center of the plate. 5. Measuring device.   The measuring device according to claim 1, wherein the plurality of sensors include sensors whose measuring directions are perpendicular to the plate.   The measuring apparatus according to claim 1, wherein the plate is formed in a rectangular shape larger than a ground contact surface of a tire that is an object to be measured and is disposed horizontally.

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