JP2018013356A - Inner gauge measurement device and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner gauge measurement technique with which it is possible to accurately measure the inner gauge of a tire over the entire inner circumference in a short time, even when the inner circumference of the tire is significantly curved.SOLUTION: Provided is an inner gauge measurement device for measuring the inner gauge of a pneumatic timer having steel cord, comprising: a roller for rotational traveling along the inner circumference of the pneumatic tire; and an eddy current sensor built into the roller, the eddy current sensor being fixed in place so that its tip is directed to a given direction independently of the rotational traveling of the roller. When measuring the inner gauge, the eddy current sensor is positioned so that its tip faces the inner surface of the pneumatic tire and the roller is made to travel along the inner surface of the tire in that state, whereby the inner gauge measurement device measures the inner gauge by the eddy current sensor.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an inner gauge measuring device for measuring the thickness of an inner liner disposed on an inner peripheral surface of a pneumatic tire, and an inner gauge measuring method using the inner gauge measuring device.

  The pneumatic tire is manufactured by laminating various materials such as an inner liner, a carcass ply, a breaker, and a tread.

  At this time, in the manufactured pneumatic tire, if the inner liner disposed on the innermost peripheral surface becomes thin, the steel cord of the carcass ply may float on the inner peripheral surface of the tire and become a defective tire. A product inspection is performed to measure the thickness (inner gauge) of the inner liner after manufacture.

  Conventionally, an eddy current sensor 20 as shown in FIG. 10A has been used for measuring the inner gauge. Specifically, the operator manually presses the eddy current sensor 20 against the measurement point A (see FIG. 10B) on the inner peripheral surface of the tire T, and then from the tip of the eddy current sensor 20 to the steel cord of the carcass ply. The distance is measured, and this value is taken as the thickness of the inner gauge.

  Conventionally, about four measurement points A have been set in the circumferential direction of the inner peripheral surface of the tire T. In recent years, as shown in FIG. It is desired to perform a more accurate inspection by measuring the entire circumference of the surface.

  However, if measurement is performed over the entire circumference of the tire T by a method of manually pressing a conventional eddy current sensor, it takes time to measure and causes work loss.

  Therefore, it has been studied to use a jig as described in Patent Documents 1 and 2 as an inner gauge measuring device. This jig is a jig used for inspecting a defect of a planar structure such as a steel floor slab. As shown in FIGS. 11 and 12, a plurality of rollers 52 connected by a frame 51 are used. The eddy current sensor 20 is disposed between the rollers. The eddy current sensor 20 performs measurement by running the roller 52 on the surface to be inspected.

JP 2008-151588 A JP 2008-249682 A

  However, since the inner peripheral surface of the tire is curved, unlike the planar measurement object (such as a steel floor slab) in Patent Documents 1 and 2, the jig shown in FIGS. When used for measuring the inner gauge of an entering tire, the large frame 51 that supports the plurality of rollers 52 may come into contact with the inner peripheral surface of the curved tire, and accurate distance measurement may not be possible.

  Further, when traveling on the inner peripheral surface of the tire, some of the plurality of rollers 52 may float from the inner peripheral surface of the tire. When the roller 52 is lifted, the distance from the tip of the eddy current sensor 20 to the inner peripheral surface of the tire is changed, resulting in variations in the measurement results of the inner gauge, making it impossible to accurately measure the distance.

  Accordingly, an object of the present invention is to provide an inner gauge measurement technique capable of accurately measuring the inner gauge of the tire over the entire circumference in a short time even if the tire has a greatly curved inner peripheral surface. To do.

  The inventor has intensively studied and found that the above-described problems can be solved by the invention described below, and has completed the present invention.

The invention described in claim 1
An inner gauge measuring device for measuring an inner gauge of a pneumatic tire having a steel cord,
A roller for rotating along the inner peripheral surface of the pneumatic tire;
An eddy current sensor built in the roller,
The eddy current sensor is fixed independently of the rotation of the roller so that the tip faces in a certain direction,
When measuring the inner gauge, the eddy current sensor is caused to run along the inner peripheral surface of the tire with the tip of the eddy current sensor facing the inner peripheral surface of the pneumatic tire. The inner gauge measuring device is characterized in that the inner gauge is measured by

The invention described in claim 2
A rotation shaft for supporting the roller;
2. The inner gauge measuring device according to claim 1, wherein the eddy current sensor is attached to a rotation shaft of the roller, and the eddy current sensor is fixed independently of the rotation of the roller. is there.

The invention according to claim 3
The ceramic ball bearing is disposed between the roller and the rotating shaft, and the eddy current sensor is fixed independently of the rotation of the roller. This is an inner gauge measuring device.

The invention according to claim 4
The roller is composed of a pair of disk-shaped rotating parts, and the eddy current sensor is fixed between the pair of disk-shaped rotating parts independently from the rotational travel of the disk-shaped rotating part. The inner gauge measuring device according to any one of claims 1 to 3.

The invention described in claim 5
The protective tape which protects the said eddy current sensor arrange | positioned between the said pair of disk shaped rotation parts is wound around the outer peripheral part of the said pair of disk shaped rotation parts. This is an inner gauge measuring device.

The invention described in claim 6
A groove recessed toward the outer surface of the roller is provided at the center in the width direction inside the roller,
2. The inner gauge measuring device according to claim 1, wherein the eddy current sensor is housed in the groove and is built in the roller.

The invention described in claim 7
The inner gauge measuring device according to any one of claims 1 to 6, wherein the roller is provided with sensor direction adjusting means for adjusting and fixing the mounting direction of the eddy current sensor. It is.

The invention according to claim 8 provides:
The inner gauge measurement according to claim 7, wherein the sensor direction adjusting means is sensor direction adjusting means for adjusting and fixing the mounting direction of the eddy current sensor in a range of 180 ° of the lower half of the roller. Device.

The invention according to claim 9 is:
The inner roller measuring device according to any one of claims 1 to 8, wherein the roller is made of a non-metal.

The invention according to claim 10 is:
10. The inner gauge measuring device according to claim 9, wherein the roller is made of polyacetal resin, polycarbonate resin, or polyethylene resin.

The invention according to claim 11
The inner gauge measuring device according to any one of claims 1 to 10, wherein the number of rollers is two or more.

The invention according to claim 12
The inner gauge measuring device according to any one of claims 1 to 11, wherein the pneumatic tire is a TB tire.

The invention according to claim 13
An inner gauge measuring method for measuring an inner gauge of a pneumatic tire using the inner gauge measuring device according to any one of claims 1 to 12,
The inner gauge is measured by the eddy current sensor by running the roller along the inner peripheral surface of the tire with the tip of the eddy current sensor facing the inner peripheral surface of the pneumatic tire. This is an inner gauge measuring method characterized in that

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a tire with which the internal peripheral surface curved, the inner gauge measurement technique which can measure the inner gauge of a tire correctly over a perimeter over a short time can be provided.

It is a perspective view of the inner gauge measuring device concerning one embodiment of the present invention. It is a figure which shows typically the structure of the inner gauge measuring apparatus which concerns on one embodiment of this invention, (a) is a side view, (b) is a front view. It is a side expansion perspective view of the inner gauge measuring device concerning one embodiment of the present invention. It is a figure explaining the inner gauge measuring method which concerns on one embodiment of this invention. It is a perspective view explaining an Example. It is a figure which shows the output from the eddy current sensor in an Example. It is a figure which shows the relationship between the output of the eddy current sensor in an Example, and the distance from a wire. It is a figure which shows the relationship between the output of an eddy current sensor in case the end is 14, and the distance from a wire. It is a figure which shows the other example of the relationship between the output of an eddy current sensor in case the end is 32, and the distance from a wire. It is a figure explaining the measurement of the conventional inner gauge. It is a side view which shows the example of the measuring apparatus provided with the eddy current sensor. It is a side view which shows the other example of the measuring apparatus provided with the eddy current sensor.

1. Outline of Inner Gauge Measuring Device (1) FIG. 1 is a perspective view showing an appearance of an inner gauge measuring device according to the present embodiment. FIG. 2 is a diagram schematically showing the configuration of the inner gauge measuring device according to the present embodiment, in which (a) is a side view and (b) is a front view. FIG. 3 is an enlarged side perspective view of the inner gauge measuring device according to the present embodiment.

  As shown in FIGS. 1 and 2, the inner gauge measuring device according to the present embodiment includes a roller 10 and an eddy current sensor 20, and the eddy current sensor 20 is built in the roller 10.

  The roller 10 can be rotated along the inner peripheral surface of the pneumatic tire. On the other hand, the eddy current sensor 20 is fixed independently of the rotating travel of the roller 10 so that the tip is directed in a certain direction, whereby the tip of the eddy current sensor 20 that detects eddy current is connected to the pneumatic tire. It can be fixed to face the inner peripheral surface.

  Using the inner gauge measuring device having such a configuration, the tip of the eddy current sensor 10 is extended over the entire circumference of the inner circumferential surface of the tire by running the roller 10 along the inner circumferential surface of the tire. The inner gauge can be measured in a state where the is opposed to the inner peripheral surface of the tire.

  For this reason, it is possible to measure the inner gauge in a much shorter time than in the conventional case where the operator measures the inner gauge while pressing the entire circumference of the inner peripheral surface of the tire by hand.

  And in this Embodiment, since the eddy current sensor 20 is incorporated in the roller 10 instead of providing an eddy current sensor between rollers unlike the measuring apparatus shown in FIG.11 and FIG.12, measuring apparatus Can be downsized to about φ8 mm. As a result, it is possible to accurately measure the inner gauge without the support member of the roller 10 supporting the eddy current sensor coming into contact with the inner peripheral surface of the tire that is greatly curved.

(2) Specific Configuration Hereinafter, members constituting the inner gauge measuring device according to the present embodiment will be specifically described.

(A) Roller and Eddy Current Sensor In the present embodiment, the roller 10 is composed of, for example, a pair of disk-shaped rotating parts 11 as shown in FIG. A current sensor 20 is arranged and built in. And the eddy current sensor 20 is being fixed independently of rotation driving of the roller 10 so that the front-end | tip may face a fixed direction. By adopting such a configuration, the roller 10 can run along the inner peripheral surface of the tire with the tip of the eddy current sensor 20 facing the inner peripheral surface of the pneumatic tire. The inner gauge can be measured accurately.

  That is, when the eddy current sensor 20 rotates in synchronization with the rotating roller 10, the distance between the eddy current sensor 20 and the steel cord to be measured changes, and an accurate measurement result cannot be obtained. In this embodiment, the eddy current sensor 20 is fixed independently of the rotation of the roller 10 so that the tip faces the inner peripheral surface of the pneumatic tire, as indicated by the arrow in FIG.

  In place of disposing the eddy current sensor 20 between the pair of disk-shaped rotating parts 10, a groove having a predetermined width and recessed toward the roller surface in the central part of one wide roller. An eddy current sensor may be disposed in the groove. Thereby, since the measurement can be performed in a state where the overcurrent sensor and the steel cord are closer, the measurement accuracy can be improved.

  In the present embodiment, the roller is preferably made of non-metal from the viewpoint of preventing eddy currents from being generated other than the steel cord to be measured and causing false detection, and specifically, made of polyacetal resin. It is preferably made of polycarbonate resin or polyethylene resin.

  Moreover, in this Embodiment, as the eddy current sensor 20, the eddy current which generate | occur | produces in a metal surface when a metal approaches in the magnetic field generated in the sensor coil of an internal front-end | tip part changes with distance to a metal. As long as the distance to the metal can be measured based on the above, a general eddy current sensor can be used.

(B) Protective tape In the roller 10 in which the eddy current sensor 20 is disposed between the pair of disk-shaped rotating portions 11 described above, the protective tape 12 that protects the eddy current sensor 20 has a pair of disk-like shapes. It is preferably wound around the outer periphery of the rotating unit 10.

  Since the protective tape 12 is wound, the eddy current sensor 20 is not in direct contact with the inner peripheral surface of the tire, so that the eddy current sensor 20 can be prevented from being damaged. Further, since the protective tape 12 is flexible, even when the tire inner surface has irregularities, it can be deformed according to the irregularities to suppress the roller from rising, and the inner gauge can be measured smoothly. it can.

  For this reason, it is preferable that the protective tape 12 has a characteristic that does not affect the measurement by the eddy current sensor. Examples of the protective tape having such a characteristic include a polyacetal resin, a polycarbonate resin, and a polyethylene resin. Can be mentioned.

(C) Rotating shaft As described above, in the present embodiment, the eddy current sensor 20 needs to be fixed so that the tip faces the inner peripheral surface of the tire independently of the rotation of the roller 10. .

  Therefore, for example, it is preferable that a ball bearing made of ceramic or the like is disposed between the roller 10 and the rotating shaft 13 so that the rotating shaft 13 supporting the roller does not rotate in synchronization with the rotating roller 10. The eddy current sensor 20 is fixed to the rotating shaft 13 by bolting or the like. Thereby, since the eddy current sensor 20 is fixed independently from the rotation of the roller 10, the tip of the eddy current sensor 20 can always be fixed facing the inner peripheral surface of the tire during measurement of the inner gauge, Accurate inner gauge measurement can be performed.

(D) Sensor direction adjusting means In the present embodiment, the inner gauge is measured over the entire circumference by rotating the roller 10 along the inner circumferential surface of the tire. When setting the roller 10 on the inner peripheral surface of the tire, it may be difficult to set the eddy current sensor 20 perpendicular to the inner peripheral surface of the tire.

  For this reason, in the inner gauge measuring device according to the present embodiment, the rotating shaft 13 of the roller 10 is adjusted by adjusting the mounting direction of the eddy current sensor so that the tip of the eddy current sensor 20 faces the inner peripheral surface of the tire. It is preferable that a sensor direction adjusting means for fixing the sensor is provided.

  By providing such sensor direction adjusting means, the tip of the eddy current sensor 20 is made to correspond to the curved surface of the inner peripheral surface of the tire as shown by the arrow in FIG. 3 with respect to the inner peripheral surface of the tire. Therefore, accurate inner gauge measurement can be performed.

  In addition, as a specific adjustment angle when adjusting the direction in which the tip of the eddy current sensor 20 is opposed, the roller 10 is used from the viewpoint of preventing disconnection of the wiring 14 extending from the eddy current sensor 20 to the measurement unit 15. The lower half of the roller 10 is preferably in the range of 180 ° when placed on the bottom surface of the inner peripheral surface of the pneumatic tire. Correspondingly, accurate inner gauge measurement can be performed.

  As a specific sensor direction adjusting means, for example, by loosening the bolt 16 arranged on the rotating shaft 13 and fixing the eddy current sensor 20, after rotating the eddy current sensor 20 to a desired angle, A method of fixing the eddy current sensor 20 by tightening the bolt 16 again can be mentioned.

2. Inner Gauge Measuring Method Next, an inner gauge measuring method performed using the inner gauge measuring device having the above configuration will be described with reference to FIG.

  First, after the manufactured tire is set on a rotatable jig, the outer peripheral surface of the roller according to the present embodiment is set along the inner peripheral surface of the set tire.

  Next, the tire is rotated. As a result, as shown in FIG. 4, the roller 10 travels while rotating along the inner peripheral surface of the tire T, and the eddy current sensor 20 built in the roller 10 moves to the entire inner peripheral surface of the tire T. In addition, the distance to the steel cord SC of the carcass ply CP located inside the inner liner IL can be measured.

  Here, an experiment for confirming the effectiveness of the inner gauge measuring method according to the present embodiment will be described with reference to FIGS.

  In this experiment, using the above-described inner gauge measuring device according to the present embodiment, as shown in FIG. 5, an arrow is placed on a film in which piano wires (diameter 0.7 mm) are stretched as wires 30 at intervals of 5 mm. The output of the overcurrent sensor while traveling was measured. In the inner gauge measuring device, the eddy current sensor built in the roller 10 is adjusted in advance downward so that the tip faces the wire 30.

  The measurement results are shown in FIG. In FIG. 6, the vertical axis represents the output (V) of the eddy current sensor, and the horizontal axis represents the elapsed time (ms) from the start of running of the inner gauge measuring device. From FIG. 6, it can be seen that the peak is confirmed when the eddy current sensor built in the rotating roller passes over the wire 30. By using the inner gauge measuring device according to the present embodiment, the inner gauge It was confirmed that measurement was possible.

  That is, since the measured peak value (peak output) is related to the distance from the eddy current sensor to the wire 30, the distance from the eddy current sensor to the wire 30 can be obtained from the peak value.

  Specifically, by varying the distance between the wire 30 and the eddy current sensor and measuring the peak value at each distance, the distance between the wire 30 and the eddy current sensor and the peak value that is the measured value are measured. The graph shown in FIG. 7 showing the relationship with (V) can be created. From FIG. 7, it can be seen that the peak value (V), which is a measured value, and the distance (mm) between the wire 30 and the eddy current sensor have a substantially linear relationship. Based on this measurement result, a relational expression between the distance (mm) of the eddy current sensor from the wire 30 and the peak value (V) can be calculated. And using this relational expression, the peak value (V) which is a measured value can be converted into a distance (mm) from the wire 30 of the eddy current sensor. In FIG. 7, the measurement value (●) immediately above the wire 30 and the measurement value (◯) between the wires 30 are shown.

  Note that in FIG. 7 described above, the peak value (V) and the distance (mm) showed a substantially linear relationship. However, there is a difference in the characteristic value obtained depending on the interval (ends) of the wires 30 and the type of the wires 30. Therefore, it is necessary to obtain an expression for obtaining the distance from the eddy current sensor to the wire 30 from the peak value according to the end and the type of the wire 30.

  For example, the relationship between the peak value (V) and the distance (mm) may be obtained as shown in FIG. 8 (measurement example of end 14) and FIG. 9 (measurement example of end 32). In this case, it divides | segments into the area | region (3 area | region in FIG. 8) which can be caught as a linear tendency, and correction | amendment formulas 1-3 as a relational expression of the peak value (V) and distance (mm) in each area | region. Create

3. As described above, in the present embodiment, the measurement is performed while rotating the roller along the inner peripheral surface of the tire, instead of performing the measurement and the inspection while the operator holds the hand. Since the inspection is performed, the inner gauge measurement over the entire inner peripheral surface of the tire can be performed in a short time, and work loss does not occur.

  And since an eddy current sensor is built in a roller and a compact inner gauge measuring device can be provided, there is no fear that a support member etc. will contact a tire inner peripheral surface.

  In addition, since only one roller with an eddy current sensor is sufficient for measuring the inner gauge, unlike when a sensor is provided between the two rollers, the roller floats and the measurement results vary. There is no fear.

  In the above description, the number of rollers is one, but two or more rollers may be used as necessary, for example, when suppressing angular displacement. Also in this case, a space for providing a sensor between the rollers is unnecessary, and the rollers can be arranged close to each other, so that the occurrence of the roller floating can be suppressed.

  And since all the fibers of the ply (case) are steel cords in the TB tire, the inner gauge measuring device and the inner gauge measuring method according to the present embodiment that can measure the distance to the steel cord with an overcurrent sensor are applied. If it does, especially remarkable effect is demonstrated.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above-described embodiments within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 10, 52 Roller 11 Disk-shaped rotation part 12 Protection tape 13 Rotating shaft 14 Wiring 15 Measurement part 16 Bolt 20 Eddy current sensor 30 Wire 51 Frame A Measurement point CP Carcass ply IL Inner liner SC Steel cord T Tire

Claims (13)

An inner gauge measuring device for measuring an inner gauge of a pneumatic tire having a steel cord,
A roller for rotating along the inner peripheral surface of the pneumatic tire;
An eddy current sensor built in the roller,
The eddy current sensor is fixed independently of the rotation of the roller so that the tip faces in a certain direction,
When measuring the inner gauge, the eddy current sensor is caused to run along the inner peripheral surface of the tire with the tip of the eddy current sensor facing the inner peripheral surface of the pneumatic tire. An inner gauge measuring device which measures the inner gauge by A rotation shaft for supporting the roller;
2. The inner gauge measurement device according to claim 1, wherein the eddy current sensor is attached to a rotation shaft of the roller, and the eddy current sensor is fixed independently of the rotation of the roller.   The ceramic ball bearing is disposed between the roller and the rotating shaft, and the eddy current sensor is fixed independently of the rotation of the roller. Inner gauge measuring device.   The roller is composed of a pair of disk-shaped rotating parts, and the eddy current sensor is fixed between the pair of disk-shaped rotating parts independently from the rotational travel of the disk-shaped rotating part. The inner gauge measuring device according to any one of claims 1 to 3.   The protective tape which protects the said eddy current sensor arrange | positioned between the said pair of disk shaped rotation parts is wound around the outer peripheral part of the said pair of disk shaped rotation parts. Inner gauge measuring device. A groove recessed toward the outer surface of the roller is provided at the center in the width direction inside the roller,
The inner gauge measuring device according to claim 1, wherein the eddy current sensor is housed in the groove and is built in the roller.   The inner gauge measuring device according to any one of claims 1 to 6, wherein the roller is provided with sensor direction adjusting means for adjusting and fixing the mounting direction of the eddy current sensor. .   The inner gauge measurement according to claim 7, wherein the sensor direction adjusting means is sensor direction adjusting means for adjusting and fixing the mounting direction of the eddy current sensor in a range of 180 ° of the lower half of the roller. apparatus.   The inner gauge measuring device according to any one of claims 1 to 8, wherein the roller is made of non-metal.   The inner gauge measuring device according to claim 9, wherein the roller is made of polyacetal resin, polycarbonate resin, or polyethylene resin.   The inner gauge measuring device according to any one of claims 1 to 10, wherein the number of the rollers is two or more.   The inner gauge measuring device according to any one of claims 1 to 11, wherein the pneumatic tire is a TB tire. An inner gauge measuring method for measuring an inner gauge of a pneumatic tire using the inner gauge measuring device according to any one of claims 1 to 12,
The inner gauge is measured by the eddy current sensor by running the roller along the inner peripheral surface of the tire with the tip of the eddy current sensor facing the inner peripheral surface of the pneumatic tire. An inner gauge measuring method characterized in that:

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