JP2019060613A - Tire inner surface shape measurement device and tire inner surface shape measurement method - Google Patents

Abstract

To provide a tire inner surface shape measurement technique which can automatically measure an inner surface of pneumatic tires of a wide variety of sizes with excellent accuracy.SOLUTION: A tire inner surface shape measurement device comprises: tire fixation means to fix and mount a conveyed pneumatic tire T on a measurement stage 2; tire centering means 3 to center the mounted tire by pressing it from an outer periphery side toward an inner periphery side using three or more bar rollers 34 disposed equiangularly; and tire inner surface shape measurement means 4 to measure an inner surface shape of the tire T while rotating the centered tire T. The tire inner surface shape measurement means 4 is configured to measure the tire inner surface shape by inserting an eddy-current sensor used as a tire inner surface detection sensor into an inner cavity of the tire and pressing it against the tire surface and measuring a distance from the inner surface of the tire to a steel cord while changing a vertical angle.SELECTED DRAWING: Figure 7

Description

  The present invention measures a tire inner surface shape measuring device that measures a tire inner surface shape by measuring a distance from an inner circumferential surface of a pneumatic tire to a steel cord, and a tire inner surface shape measuring method performed using the tire inner surface shape measuring device About.

  Pneumatic tires are manufactured by laminating various materials such as inner liners, carcass plies, breakers and treads, and thickness control of these is important for quality assurance.

  In particular, when the thickness of the inner liner disposed on the innermost circumferential surface is thin, not only air tightness can not be secured, but also the steel cord of the carcass ply floats on the inner circumferential surface of the tire, resulting in a defective tire. Therefore, the thickness of the inner liner (inner gauge) is confirmed by measuring the shape of the inner cavity of the tire (the shape of the inner surface of the tire) in product inspection. Specifically, the inner surface shape of the tire is measured by measuring the distance from the inner circumferential surface of the tire to the steel cord of the carcass ply, and the obtained distance is used as the inner gauge.

  An eddy current displacement sensor (hereinafter also referred to as "eddy current sensor") is generally used to measure the distance from the surface of the tire to the steel cord. A tire surface rubber thickness measuring device capable of automatically measuring the layer thickness has been developed (see, for example, Patent Document 1).

JP-A-8-304009

  However, since the tire has different outer diameter and width depending on its size and different inner surface shape, it has been difficult to measure the inner surface shape by automation according to various sized pneumatic tires.

  Therefore, in the past, the operator measured the eddy current sensor against each measurement point on the inner circumferential surface of the tire by hand, but if it was attempted to carry out the measurement over the entire circumference of the tire by this method, the measurement The problem is that it takes a lot of time and effort. Also, it can not be said that its accuracy is high enough.

  Therefore, an object of the present invention is to provide a tire inner surface shape measurement technique capable of automatically measuring the inner surface of pneumatic tires of various sizes with high accuracy.

  The inventors of the present invention conducted intensive studies and found that the above-mentioned problems could be solved by the invention described below, and completed the present invention.

The invention according to claim 1 is
A tire inner surface shape measuring device for measuring the inner surface shape of a pneumatic tire having a steel cord transported in a transversely disposed state, comprising:
Tire fixing means for fixing and mounting the pneumatic tire conveyed at a predetermined position on a measurement table;
Tire centering means for centering the pneumatic tire placed thereon by pressing it from the outer peripheral side to the inner peripheral side using three or more bar rollers arranged at equal angles;
Tire inner surface shape measuring means for measuring the inner surface shape of the pneumatic tire while rotating the centered pneumatic tire;
The tire inner surface shape measuring means uses the eddy current sensor as a tire inner surface detection sensor, inserts the tire inner surface detection sensor into the inner cavity of the pneumatic tire and presses the inner surface of the pneumatic tire. The inner surface shape of the tire is measured by measuring the distance from the inner surface of the pneumatic tire to the steel cord while changing the vertical angle with respect to the surface It is an apparatus.

The invention according to claim 2 is
The tire centering means according to claim 1, characterized in that the tire centering means has a tire support mechanism for supporting and holding the pneumatic tire mounted thereon by a free ball bearing rising from below the measurement table. The tire inner surface shape measuring device of

The invention according to claim 3 is
The tire rotation mechanism according to claim 1 or 2, characterized in that the tire inner surface shape measuring means rotates the pneumatic tire by using a conveyor roller disposed on the measurement table. It is a tire inner surface shape measuring device.

The invention according to claim 4 is
The tire inner surface detection sensor is disposed below the measurement table at a center position of the centered tire, and is configured to ascend above the measurement table when measuring the inner surface of the tire. The tire inner surface shape measuring device according to any one of claims 1 to 3, characterized in that

The invention according to claim 5 is
The tire inner surface shape measuring means is
A measurement head comprising the tire inner surface detection sensor;
The measuring head support mechanism which moves the said measuring head horizontally to the inner peripheral surface of the said pneumatic tire, and supports it 180 degrees up and down variably is provided. It is a tire inner surface shape measuring device given in any 1 paragraph.

The invention according to claim 6 is
The measuring head
A roller for rotationally traveling along an inner circumferential surface of the pneumatic tire;
And an eddy current sensor built into the roller,
The eddy current sensor is fixed independently of the rotational travel of the roller so that the tip of the eddy current sensor points in a certain direction,
At the time of measurement of the tire inner surface shape, the roller is caused to travel along the inner circumferential surface of the pneumatic tire in a state where the tip of the eddy current sensor is opposed to the inner circumferential surface of the pneumatic tire. The tire inner surface shape measuring apparatus according to claim 5, wherein the inner surface shape of the pneumatic tire is measured by an eddy current sensor.

The invention according to claim 7 is
The measuring head comprises a rotating shaft supporting the roller,
The tire inner surface shape measuring apparatus according to claim 6, wherein the eddy current sensor is attached to a rotation shaft of the roller, and the eddy current sensor is fixed independently of the rotational travel of the roller. It is.

The invention according to claim 8 is
The measurement head is provided with a groove recessed toward the outer surface of the roller at a central portion in the width direction inside the roller,
The tire inner surface shape measuring device according to claim 6 or 7, wherein the eddy current sensor is accommodated in the groove and built in the roller.

The invention according to claim 9 is
The tire inner surface shape measuring apparatus according to any one of claims 6 to 8, wherein the roller is made of a nonmetal.

The invention according to claim 10 is
The tire inner surface shape measuring apparatus according to claim 9, wherein the roller is made of polyacetal resin, polycarbonate resin, or polyethylene resin.

The invention according to claim 11 is
11. The tire inner surface shape measuring device according to any one of claims 1 to 10, which is a device for measuring the inner surface shape of a truck bus tire.

The invention according to claim 12 is
A tire inner surface shape measuring method for measuring the inner surface shape of a pneumatic tire having a steel cord transported in a transversely placed state by using the tire inner surface shape measuring device according to any one of claims 1 to 11. And
A tire fixing step of fixing and mounting the pneumatic tire conveyed at a predetermined position of a measurement table;
A tire centering step of centering the pneumatic tire placed thereon by pressing it from the outer peripheral side to the inner peripheral side using three or more bar rollers arranged at equal angles;
A tire inner surface shape measuring step of measuring an inner surface shape of the pneumatic tire while rotating the centered pneumatic tire;
The tire inner surface shape measuring step uses the eddy current sensor as a tire inner surface detection sensor, inserts the tire inner surface detection sensor into the inner cavity of the pneumatic tire, and presses the inner surface of the pneumatic tire. The tire inner surface shape is measured by measuring the distance from the inner surface of the pneumatic tire to the steel cord while changing the vertical angle with respect to the surface.

The invention according to claim 13 is
The tire inner surface shape measuring method according to claim 12, wherein in the tire centering step, the placed pneumatic tire is supported and held by a free ball bearing rising from the lower side of the measurement table. .

The invention according to claim 14 is
The tire inner surface shape measuring method according to claim 12 or 13, wherein in the tire inner surface shape measuring step, the pneumatic tire is rotated using a conveyor roller disposed on the measurement table.

The invention according to claim 15 is
In the tire inner surface shape measuring step, the tire inner surface detection sensor disposed under the measurement table is raised to the upper side of the measurement surface when measuring the tire inner surface shape at the center position of the centered tire. A tire inner surface shape measuring method according to any one of claims 12 to 14, characterized in that:

The invention according to claim 16 is
The tire inner surface shape measuring step
A measuring head support mechanism for moving the measuring head attached to the tip portion of the tire inner surface detection sensor horizontally to the inner circumferential surface of the pneumatic tire and supporting it variably 180 ° vertically. The tire inner surface shape measuring method according to any one of claims 12 to 15.

The invention according to claim 17 is
The tire inner surface shape measuring method according to any one of claims 12 to 16, wherein the pneumatic tire is a truck bus tire.

  According to the present invention, it is possible to provide a tire inner surface shape measurement technique capable of automatically measuring the inner surface of pneumatic tires of various sizes with high accuracy.

FIG. 1 is a side view of a tire inner surface shape measuring apparatus according to an embodiment of the present invention. It is a front view of a tire inner surface shape measuring device concerning a 1 embodiment of the present invention. It is a top view of the measurement stand of the tire inner surface shape measuring device concerning the 1 embodiment of the present invention. It is a top view of the centering mechanism of the tire inner surface shape measuring device concerning the 1 embodiment of the present invention. It is a top view of a tire support mechanism. It is a front view of a tire support mechanism. It is a side view of a tire support mechanism. It is a front view which shows the structure of tire inner surface shape measurement means. (1) It is a side view of a measuring head of a tire inner surface shape measuring device concerning an embodiment of the invention. (2) It is a front view of the measuring head of the tire inner surface shape measuring apparatus based on one embodiment of this invention. (1) It is a top view of the centering mechanism of a diameter-expanding state. (2) It is an AA arrow line view of the centering mechanism of a diameter-expanding state. (1) It is a top view of the centering mechanism in a diameter-reduced state. (2) It is an AA arrow line view of the centering mechanism in a diameter-reduced state. It is a schematic diagram explaining position adjustment of tire inner surface shape measurement head. It is a schematic diagram which shows the tire inner surface shape measuring method.

[1] Outline of the Present Invention The tire inner surface shape measuring device according to the present invention is a device for measuring the inner surface shape of a pneumatic tire having a steel cord transported in a transversely placed state, which comprises conveying means such as a belt conveyor. The tire conveyed by the above is placed on the measurement stand and centered on the center of the device by the tire centering means, and then the tire inner surface detection sensor (eddy current sensor) is inserted into the inner cavity of the tire, The tire inner surface shape is automatically measured by repeating the measurement of the distance to the steel cord while changing the vertical angle while rotating.

  And since the tire inner surface shape measuring apparatus according to the present invention is configured to be centered by pressing from the outer peripheral side to the inner peripheral side using three or more bar rollers arranged at equal angles, which Even with a tire of such a size, centering can be reliably performed, and the inner surface shape of the tire can be measured with high accuracy.

[2] Embodiments of the Present Invention Hereinafter, the present invention will be specifically described based on the embodiments of the present invention with reference to the drawings.

A. Tire inner surface shape measuring apparatus 1. Basic Configuration of Device FIG. 1A is a side view of a tire inner surface shape measuring device, and FIG. 1B is a front view. In the figure, 1 is a tire inner surface shape measuring device, 2 is a measurement stand, 3a is a centering mechanism, 3b is a tire support mechanism, and 4 is a tire inner surface shape measuring means. The white thick arrows in FIG. 1A indicate the transport direction of the tire. A conveyor roller 21 is provided on the upper surface of the measurement stand 2, and a tire support mechanism 3 b is provided below the measurement stand 2. Further, a centering mechanism 3 a is provided above the measuring table 2.

  The centering mechanism 3a includes frames 32, 33 mounted on the ceiling, three or more (four in the figure) bar rollers 34 disposed equiangularly from the frames 32, 33 and suspended, and the frames 32, 33. The expansion / contraction diameter drive device 35 provided at the upper part of The tire inner surface shape measurement means 4 is installed below the central portion of the measurement stand 2 so as to be capable of vertical movement and horizontal movement. The operation of these is controlled by control means (not shown). Hereinafter, each configuration of the tire inner surface shape measuring device will be described in detail.

2. Measuring stand FIG. 1C is a plan view of a measuring stand of the tire inner surface shape measuring apparatus according to the present embodiment. As shown in FIG. 1C, the measurement table 2 is configured to have a horizontal mounting surface by a plurality of conveyor rollers 21 arranged in parallel with a predetermined gap horizontally and vertically to the tire conveyance direction indicated by the arrow. doing. The center in the width direction and the longitudinal direction of the mounting surface coincides with the center (measurement center) C when the centered tire is measured.

  The mounting surface is partitioned at the center in the width direction and at the center in the longitudinal direction, and a space in which the conveyor roller 21 does not exist is provided at each center. This space is used as a passage for raising and lowering the measuring head of the tire inner surface shape measuring means 4 as described later.

  The measurement table 2 has a space in the longitudinal direction and the mounting surface is divided into two in the width direction, and is configured such that two sets of conveyor rollers 21 disposed on both sides can be rotated in opposite directions. This configuration functions as a tire rotation mechanism when measuring the inner surface of the tire. Specifically, when measuring the inner surface of the tire, following the centering, the tire rotates around the measurement center C on the measurement table by rotating the two conveyor rollers 21 in opposite directions. . The tire rotation mechanism is driven by the motor 22 of FIG. 1A. It is also possible to use a conveyor belt instead of the conveyor roller 21 for the tire rotation mechanism.

  A tire support mechanism 3b extending in the width direction is provided below both sides of the gap at the central portion in the longitudinal direction of the measurement stand 2. The tire support mechanism 3b functions as a member constituting the tire centering means 3 described later.

3. Tire Centering Means The tire centering means 3 includes a centering mechanism 3a and a tire support mechanism 3b. The cooperation of the centering mechanism 3a and the tire support mechanism 3b enables centering of the placed tire quickly.

(1) Centering Mechanism FIG. 1D is a plan view of the centering mechanism of the tire inner surface shape measuring apparatus according to the present embodiment. As described above, the centering mechanism 3a is installed above the measurement stand 2 and attached to the ceiling of the housing 36 (see FIGS. 1A and 1B). As shown in FIG. 1D, the centering mechanism 3a includes a frame 32 extending in a cross shape in the horizontal direction. At this time, the center of the cross is located immediately above the measurement center C, and the tips of the cross extend to form an angle of 45 ° with the tire conveyance direction. A total of four bar rollers 34 are slidably and rotatably attached along the respective tips, one at each end of the cross. Each bar roller 34 is suspended downwardly from the frame 32.

  Also, on the lower side of the frame 32, a small size cruciform frame 33 is horizontally mounted. The center of the cross of the frame 33 is located directly above the measurement center C, and is supported by a rotation axis provided vertically to the measurement center C.

  Under the frame 33, four arms 31 having the same shape and the same size are installed, and one end (tip end) 31a of each arm 31 is provided at each end of the cross of the frame 32. The other end (rear end) 31 b is connected to the tip of the cross of the frame 33 so that it can slide along the elongated hole and the other end (rear end) 31 b is connected to the base of each of the four bar rollers 34. Being fixed. The four front end portions 31a and the rear end portions 31b are located at equal intervals on the circumference of a circle centered on the measurement center C, respectively.

  An expansion / contraction diameter drive unit 35 is mounted on the upper side of the housing 36, and the expansion / contraction diameter drive unit 35 is connected to the rotation shaft so as to rotate the frame 33 by a predetermined angle around the rotation shaft. There is. Along with this rotation, the bar roller 34 to which the tip end 31a of the arm 31 is connected slides in synchronization along the frame 32, and expands and contracts inward and outward around the measurement center C. At this time, the diameter of the circle formed by the four bar rollers 34 is adjusted by adjusting the size of the rotation angle of the frame 33. When the bar roller 34 is contracted, the tire is pressed from the outer peripheral side to the inner diameter side, and when all the four bar rollers 34 are in contact with the outer peripheral surface of the tire, the tire is disposed centered on the measurement center C , Centering is complete.

  As described above, the centering mechanism 3a according to the present embodiment is configured to press the tire from the outer peripheral side to the inner peripheral side and center it by reducing the diameter of the four bar rollers 34 arranged at equal angles. Because of this, tires of any size can be reliably centered.

(2) Tire support mechanism The tire support mechanism 3b is provided to hold the tire to be centered from below, and as shown in FIG. 1C, each of the mounting surfaces of the measurement table 2 divided into four pieces. In the section of (1), there are provided free ball bearings in which a large number of ball bearings installed parallel to the conveyor roller 21 are arranged in a straight line.

  FIG. 2 is a view showing the structure of the tire support mechanism 3b, and FIGS. 2A, 2B and 2C are a plan view, a front view and a side view, respectively. In the figure, 37 is a free ball bearing, 38 is a lifting device, and 39 is a support bar. The free ball bearing 37 is horizontally supported by the support bar 39, and is lifted and lowered by the lifting device 38. When not in operation, it is stored under the mounting surface of the measurement table 2. During operation, the four free ball bearings 37 synchronously rise through the gap of the conveyor roller 21 onto the mounting surface, and the tire The base is supported movably and rotatably in all horizontal directions.

  As described above, the tire support mechanism 3b supports the tire by supporting the tire with the raised free ball bearing so that the tire can be moved in all horizontal directions and rotatably supported, so that the centering of the tire can be performed more smoothly. It will be.

4. Tire Inner Surface Shape Measuring Means The tire inner surface shape measuring means of this embodiment inserts the tire inner surface detection sensor into the inner cavity of the tire and aligns it with the inner peripheral surface of the tire, and then rotates the tire to The measurement of the distance from the inner surface to the steel cord is repeated while changing the vertical angle to measure the tire inner surface shape.

  FIG. 3 is a front view showing the configuration of the tire inner surface shape measuring means. The tire inner surface shape measurement means 4 is installed below the mounting surface of the measurement stand 2. By thus installing the tire inner surface shape measuring means 4 below the mounting surface, the tire inner surface shape measuring means 4 can be installed on the measurement center C without interfering with the centering mechanism 3a.

  As shown in FIG. 3, the tire inner surface shape measurement means 4 includes a measurement head 43 and a measurement head support mechanism. The measurement head support mechanism includes a lift member 41 having a measurement head 43 mounted at its upper end, a horizontal bar 42, and a measurement head support arm 44 for supporting the measurement head.

  The horizontal bar 42 is disposed immediately below the space provided along the width direction at the center of the measurement stand 2 in the longitudinal direction. The elevating member 41 is supported by the horizontal bar 42 so as to be movable along the horizontal bar 42 by the horizontal movement mechanism and to be vertically movable by the elevation mechanism. At the time of measurement, the elevating member 41 ascends, the measuring head 43 passes through the space and ascends to a height necessary for the measurement, descends after the measurement is completed, and stands by below the mounting surface. Note that, for example, a linear actuator is used for the horizontal movement mechanism, and a known mechanism such as a cylinder is used for the elevation mechanism.

  The measurement head support arm 44 is attached to the upper end portion of the elevating member 41 in a direction parallel to the space directly above the horizontal bar 42, that is, immediately below the space. The measuring head support arm 44 can be expanded and contracted by an expansion and contraction mechanism, and the measuring head 43 is attached to the tip portion. In addition, a known mechanism such as an air cylinder is used as the extension mechanism. The tip portion is provided with a swing mechanism, and the measuring head 43 can freely change its angle over approximately 180 ° between upward and downward. In addition, well-known mechanisms, such as a rotary actuator, are used for a swing mechanism.

  As described above, the tire inner surface shape measuring means according to the present embodiment includes the horizontal movement mechanism, the elevating mechanism, the extension mechanism, and the swing mechanism, so that the inner surface shape is measured corresponding to tires of various sizes. can do.

  FIG. 4 is a view showing the configuration of the measurement head 43, and FIGS. 4 (1) and 4 (2) are a side view and a front view, respectively. As shown in FIG. 4, the measuring head 43 of the present embodiment includes a roller 43b and an eddy current sensor 43a, and the eddy current sensor 43a is built in the roller 43b. Specifically, the roller 43b is constituted of, for example, a pair of disk-shaped rotating portions 43c, and the eddy current sensor 43a is disposed and incorporated between the pair of disk-shaped rotating portions 43c.

  The eddy current sensor 43a is fixed independently of the rotational travel of the roller 43b so that the tip is directed in a certain direction. In the measurement head 43, a rotation shaft 43d is provided inside the roller 43b. The rotation shaft 43d itself does not rotate, and rotatably supports the disk-like rotation portion 43c. On the other hand, the eddy current sensor 43a is supported by a support member 43e attached at the center of the rotating shaft 43d in a fixed direction with the rotating shaft as a fulcrum, for example, toward the tip side of the measuring head 43 It is. The disc-like rotation portion 43c is rotatably supported on the rotation shaft 43d via a bearing or the like using a ball bearing made of, for example, a ceramic material that does not inhibit the measurement. Further, 45 is a wiring, and 46 is a measuring unit.

  Thus, by making the roller 43b into one, the contact point between the measurement head 43 and the inner surface of the tire is limited to one, and by making the outer peripheral surface of the roller 43b a curved surface with the central portion protruding, the inner surface of the tire The measuring head can also be scanned with a minimal contact area on the curved surface of. Further, the direction of the eddy current sensor 43a is constant. For this reason, the variation in the distance between the eddy current sensor 43a and the inner surface of the tire during measurement can be minimized, and as a result, the inner surface of the tire can be measured accurately. In addition, since the shape of the outer peripheral surface of the roller 43b is a shape suitable for rotational travel on a curved surface, it is possible to automatically travel on the inner surface of the rotating tire without vibration.

  Further, it is preferable that the eddy current sensor 43a is fixed so that the tip thereof faces the tire surface, and for that purpose, it is preferable that the eddy current sensor 43a can be attached to the rotating shaft 43d so that its direction can be adjusted as needed. .

  Incidentally, instead of the configuration shown in FIG. 4 in which the eddy current sensor 43a is disposed between the pair of disk-shaped rotating portions 43c, a predetermined width at the center part inside one wide roller faces the roller surface. An eddy current sensor may be disposed in the groove by forming a recessed groove. As a result, measurement can be performed in a state where the overcurrent sensor and the steel cord are brought closer to each other, so that measurement accuracy can be improved.

  In the present embodiment, the roller is preferably made of non-metal from the viewpoint of preventing erroneous detection due to generation of eddy current from other than the steel cord to be measured, and specifically, polyacetal resin Preferably, it is made of polycarbonate resin or polyethylene resin.

  Further, in the present embodiment, as the eddy current sensor 43a, the eddy current generated on the metal surface when the metal approaches the magnetic field generated in the sensor coil at the inner end changes with the distance to the metal. It is sufficient if the distance to the metal can be measured based on it, and a general eddy current sensor can be used.

5. Control means The control means previously stores, for each tire size, each parameter necessary for measurement of the inner surface shape, such as position data in the height direction of the inner surface, distance from the measurement center C, and angle with the horizontal surface. The parameters corresponding to the tire size are selected to control the operation of the tire inner surface shape measuring means.

  Specifically, when the size of the tire to be measured is input to the control means, the control means obtains data of the tire of the corresponding size out of all the stored data, and based on the data, the horizontal movement mechanism The elevation mechanism and the swing mechanism are driven to adjust the position in the height direction of the measurement head 43, the horizontal position, and the angle with the horizontal surface so that the measurement head 43 is pressed against the inner surface of the tire.

B. Tire Inner Surface Shape Measurement Method A measurement method using the tire inner surface shape measurement apparatus of the present embodiment is performed in two steps of a tire centering process of a tire carried in and a tire inner surface shape measurement process following it. In the following description, the tire inner surface shape measuring device is described as being incorporated in a tire manufacturing line. Each process is described in detail below.

1. Tire centering process Figure 5, Figure 6 is a diagram showing the operation of the centering mechanism, Figure 5 (1) is a plan view of the centering mechanism in the state of diameter expansion, Figure 5 (2) is an arrow AA of (1) FIG. On the other hand, FIG. 6 (1) is a plan view of the centering mechanism in the diameter-reduced state, and FIG. 6 (2) is a view taken along the line AA in (1). The size of the maximum diameter and the minimum diameter is set to a size that enables centering with any size tire, in consideration of the size of the outer diameter of various types of tires.

  Before the tire is carried into the measuring stand 2, the centering mechanism 3 a stands by above the measuring stand 2 and expands in diameter. The state shown in FIG. 5 shows a state in which the diameter is expanded to the maximum. The slidable range of the front end portion 31a is set according to the maximum diameter and the minimum diameter, and the rotation movable range of the rear end portion 31b is determined correspondingly. In FIG. 5, the tip end 31a of each arm 31 is located at the outer end farthest from the measurement center C of the slidable range. Further, the rear end portion 31 b is located at a position closest to the outer end of the rotation movable range. At this time, the distance between the adjacent bar rollers 34 is larger than the outer diameter of the tire, and the tire carried into the measuring stand 2 is carried inside the circle inscribed in the four bar rollers 34.

  The tire is carried in by the conveyor connected to the upstream of the measurement stand 2 in a horizontally placed state, and carried in to the inside of the circle inscribed in the four bar rollers 34. When the sensor detects the loading of the tire, the conveyor stops, and the tire is fixed and placed on the measurement table 2. Thereafter, the centering mechanism 3a is lowered, and the four bar rollers 34 are positioned outward of the tire. Thereafter, the expanding / contracting diameter driving device 35 is driven to rotate the frame 33, and the rear end portions 31b of the arms 31 are synchronously moved away from the outer end. Along with this, the tip end 31a moves synchronously along the frame 32 toward the measurement center C, and the diameter of the circle formed by the four bar rollers 34 decreases. At this time, the bar roller 34 pushes the outer peripheral surface of the tire from the outside to the inner diameter side, and the tire is moved so that the radial center of the tire is positioned directly above the measurement center C.

  When the radial center of the tire approaches directly above the measurement center C, specifically, when the sidewall of the tire comes to a position where it is hung on the four free ball bearings 37, the lifting device 38 is driven. The free ball bearing 37 is raised above the mounting surface of the measurement stand 2, and the tire is supported by the four free ball bearings 37. After this, the circle on which the four bar rollers 34 hang down is further gradually reduced in diameter to finely adjust the position of the tire. Finally, centering is ended when the diameter of the circle inscribed in the four bar rollers 34 becomes equal to the outer diameter of the tire. As a result, the radial center of the tire can be accurately positioned immediately above the measurement center C.

  FIG. 6 shows a state where the diameter is reduced to the minimum, and the tip end 31a of each arm 31 is located at the inner end closest to the center C of the slidable range. Further, the rear end portion 31 b is located at a position closest to the inner end of the rotation movable range. The maximum diameter shown in FIG. 5 and the size of the minimum diameter shown in FIG. 6 are set to a size that allows centering with any size tire, taking into consideration the outer diameters of various types of tires. There is.

  Also, with the operation of the centering mechanism, the tire support mechanism 3b stored under the mounting surface of the measurement table 2 when not in operation passes the gap of the conveyor roller 21 and the four free ball bearings 37 Synchronously, it rises above the mounting surface, and supports the tire so as to be movable in all horizontal directions and rotatably.

2. Tire Inner Surface Shape Measurement Step After the centering of the tire is completed, a tire inner surface shape measurement step is subsequently performed. FIG. 7 is a schematic view for explaining the position adjustment of the tire inner surface shape measuring head. The tire T is centered and rotatably supported by a bar roller 34. First, the conveyor rollers on one side and the other side on the measurement stand 2 which is a tire rotation mechanism start rotating in reverse rotation, and the tire T rotates at a predetermined speed. At the same time, the measuring head 43 rises to a predetermined height.

  Next, the elevating mechanism of the elevating member 41 and the horizontal movement mechanism are operated by the command from the control means to adjust the position of the measuring head 43 in the height direction and the horizontal position, and further the neck of the measuring head support arm 44 The swing mechanism operates to adjust the orientation of the measuring head 43, and the tip of the measuring head 43 is pressed against the inner surface of the tire. In the tire inner surface shape measurement, for example, the direction (angle) of the measuring head 43 is changed up and down in the order of the upper sidewall, upper shoulder, tread, lower shoulder and lower sidewall. It is done automatically.

  In addition, when measuring a portion having a width in the height direction, such as the tread portion, the elevation mechanism changes the height of the measurement head 43 while scanning the measurement head 43, and the radial direction as in the sidewall portion In the measurement of the portion where there is a width, the horizontal position change is performed by the telescopic mechanism of the measurement head support arm 44. Further, when measuring a curved surface such as a sidewall portion or a shoulder portion, the swing mechanism changes the vertical direction of the measuring head 43.

  FIG. 8 is a schematic view showing a method of measuring the inner surface of the tire. In FIG. 8, IL is an inner liner, CP is a carcass ply, and SC is a steel cord. The inner surface of the tire can be measured by scanning the inner surface of the tire while pressing the measuring head 43 against the inner surface of the tire so that the eddy current sensor 43a always faces the inner liner IL as shown in FIG. 8 by the above adjustment. . For this reason, the tire inner surface shape can be measured with high accuracy.

  When the tire inner surface shape measurement is finished, the conveyor roller 21 stops its rotation, and the centering mechanism 3a expands and separates from the tire. The lower support mechanism 3b is also housed in the lower part of the measurement stand. The tire after measurement is usually sent downstream of the conveyor. In addition, a tire that has been found to be defective by tire inner surface shape measurement is removed from the production line.

  As described above, according to the tire inner surface shape measuring apparatus and method of the present embodiment, the tire centering means is constituted by a plurality of bar rollers and the tire centering is performed by pushing from the outer peripheral side to the inner peripheral side. Since the inner surface shape measuring means can move up and down, move horizontally, and can rotate up and down by the swing mechanism, it can cope with measurement of various parts of various sized tires having different outer diameter, width and inner surface shape. it can. In addition, it can be incorporated into the process of a tire manufacturing line to automatically measure the tire conveyed by the conveyor in the state of being placed horizontally. It is very efficient without setting the tire from horizontal orientation to vertical orientation and returning it to horizontal orientation again at the time of measurement, and equipment and the like.

  As mentioned above, although the present invention was explained based on an embodiment, the present invention is not limited to the above-mentioned embodiment. Various modifications can be made to the above embodiment within the same and equivalent scope of the present invention.

DESCRIPTION OF SYMBOLS 1 tire inner surface shape measuring apparatus 2 measuring stand 3 tire centering means 3a centering mechanism 3b tire support mechanism 4 tire inner surface shape measuring means 21 conveyor roller 22 motor 31 arm 31a tip end 31b rear end 32 33 frame 34 bar roller 35 Expanded and reduced diameter drive device 36 Housing 37 Free ball bearing 38 Lifting device 39 Support bar 41 Lifting member 42 Horizontal bar 43 Measurement head 43a Eddy current sensor 43b Roller 43c Disc-like rotation part 43d Rotation shaft 43e Support member 44 Measurement head support arm 45 Wiring 46 Measurement part C Measurement center CP Carcass ply IL Inner liner SC Steel cord T Tire

Claims (17)

A tire inner surface shape measuring device for measuring the inner surface shape of a pneumatic tire having a steel cord transported in a transversely disposed state, comprising:
Tire fixing means for fixing and mounting the pneumatic tire conveyed at a predetermined position on a measurement table;
Tire centering means for centering the pneumatic tire placed thereon by pressing it from the outer peripheral side to the inner peripheral side using three or more bar rollers arranged at equal angles;
Tire inner surface shape measuring means for measuring the inner surface shape of the pneumatic tire while rotating the centered pneumatic tire;
The tire inner surface shape measuring means uses the eddy current sensor as a tire inner surface detection sensor, inserts the tire inner surface detection sensor into the inner cavity of the pneumatic tire and presses the inner surface of the pneumatic tire. The inner surface shape of the tire is measured by measuring the distance from the inner surface of the pneumatic tire to the steel cord while changing the vertical angle with respect to the surface apparatus.   The tire centering means according to claim 1, characterized in that the tire centering means has a tire support mechanism for supporting and holding the pneumatic tire mounted thereon by a free ball bearing rising from below the measurement table. Tire inner surface shape measuring device.   The tire rotation mechanism according to claim 1 or 2, characterized in that the tire inner surface shape measuring means rotates the pneumatic tire by using a conveyor roller disposed on the measurement table. Tire inner surface shape measuring device.   The tire inner surface detection sensor is disposed below the measurement table at a center position of the centered tire, and is configured to ascend above the measurement table when measuring the inner surface of the tire. The tire inner surface shape measuring apparatus according to any one of claims 1 to 3, characterized in that The tire inner surface shape measuring means is
A measurement head comprising the tire inner surface detection sensor;
The measuring head support mechanism which moves the said measuring head horizontally to the inner peripheral surface of the said pneumatic tire, and supports it 180 degrees up and down variably is provided. The tire inner surface shape measuring device according to 1 or 2. The measuring head
A roller for rotationally traveling along an inner circumferential surface of the pneumatic tire;
And an eddy current sensor built into the roller,
The eddy current sensor is fixed independently of the rotational travel of the roller so that the tip of the eddy current sensor points in a certain direction,
At the time of measurement of the tire inner surface shape, the roller is caused to travel along the inner circumferential surface of the pneumatic tire in a state where the tip of the eddy current sensor is opposed to the inner circumferential surface of the pneumatic tire. The tire inner surface shape measuring apparatus according to claim 5, wherein the inner surface shape of the pneumatic tire is measured by an eddy current sensor. The measuring head comprises a rotating shaft supporting the roller,
The tire inner surface shape measuring apparatus according to claim 6, wherein the eddy current sensor is attached to a rotation shaft of the roller, and the eddy current sensor is fixed independently of the rotational travel of the roller. . The measurement head is provided with a groove recessed toward the outer surface of the roller at a central portion in the width direction inside the roller,
The tire inner surface shape measuring apparatus according to claim 6 or 7, wherein the eddy current sensor is accommodated in the groove and built in the roller.   The tire inner surface shape measuring apparatus according to any one of claims 6 to 8, wherein the roller is made of non-metal.   10. The tire inner surface shape measuring device according to claim 9, wherein the roller is made of polyacetal resin, polycarbonate resin, or polyethylene resin.   11. The tire inner surface shape measuring device according to any one of claims 1 to 10, which is a device for measuring the inner surface shape of a truck bus tire. A tire inner surface shape measuring method for measuring the inner surface shape of a pneumatic tire having a steel cord transported in a transversely placed state by using the tire inner surface shape measuring device according to any one of claims 1 to 11. And
A tire fixing step of fixing and mounting the pneumatic tire conveyed at a predetermined position of a measurement table;
A tire centering step of centering the pneumatic tire placed thereon by pressing it from the outer peripheral side to the inner peripheral side using three or more bar rollers arranged at equal angles;
A tire inner surface shape measuring step of measuring an inner surface shape of the pneumatic tire while rotating the centered pneumatic tire;
The tire inner surface shape measuring step uses the eddy current sensor as a tire inner surface detection sensor, inserts the tire inner surface detection sensor into the inner cavity of the pneumatic tire, and presses the inner surface of the pneumatic tire. A tire inner surface shape measuring method comprising measuring a tire inner surface shape by measuring a distance from an inner surface of the pneumatic tire to the steel cord while changing an upper and lower angle with respect to a surface.   13. The tire inner surface shape measuring method according to claim 12, wherein in the tire centering step, the placed pneumatic tire is supported and held by a free ball bearing rising from the lower side of the measurement table.   The tire inner surface shape measuring method according to claim 12 or 13, wherein in the tire inner surface shape measuring step, the pneumatic tire is rotated using a conveyor roller disposed on the measurement table.   In the tire inner surface shape measuring step, the tire inner surface detection sensor disposed under the measurement table is raised to the upper side of the measurement surface when measuring the tire inner surface shape at the center position of the centered tire. The tire inner surface shape measuring method according to any one of claims 12 to 14, characterized in that: The tire inner surface shape measuring step
A measuring head support mechanism for moving the measuring head attached to the tip portion of the tire inner surface detection sensor horizontally to the inner circumferential surface of the pneumatic tire and supporting it variably 180 ° vertically. The tire inner surface shape measuring method according to any one of claims 12 to 15.   The tire inner surface shape measuring method according to any one of claims 12 to 16, wherein the pneumatic tire is a truck bus tire.

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