JP4878299B2 - Rim assembly tire assembly state measurement method - Google Patents

Description

  The present invention relates to a method for measuring the inside of a tire using X-ray irradiation means, and in particular, a set of rim-attached tires capable of measuring a rim and a tire-attached portion in a state where the tire is attached to a rim. The present invention relates to an attached state measuring method.

  The tire is an important part that supports the vehicle body, transmits driving force, improves the riding comfort with the air accumulated inside, and the front wheels also steer. For this reason, it can be said that the safety of the car is borne by the tires. Here, the assembly part of the rim and the tire is an important part for firmly fixing the tire to the wheel.

For this reason, it is important to grasp the assembled state of the rim and the tire. However, since the assembly part of a rim and a tire is located inside the rim assembly tire, there is a problem that it cannot be visually observed directly from the outside.
Against this backdrop, a method using CT scan has been proposed as a technique for visualizing the inside of a rim-assembled tire (Patent Document 1).

However, the proposed CT scan method radiates radiation from the radiation source arranged outside the rotated rim-attached tire in the radial direction of the rim-attached tire, and arranges it at the center of rotation of the rim-attached tire. The attenuation amount of the radiation radiated by the radiation detector is detected, and a cross-sectional view of the assembled state of the rim and the tire is formed by the image forming processing unit based on the detected transmittance data. For this reason, there is a drawback that it takes a long time from the start of photographing until a cross-sectional image of the portion to be photographed can be obtained, and the assembled state of the rim assembled tire is continuously measured in a short time over the entire circumference of the tire. Not suitable for.
Japanese Patent Publication No.8-1377

  The present invention has been made to solve the above problem, and is a method for measuring an assembled state of a rim-attached tire, which can continuously measure the assembled state of a rim and a tire over a circumference of the tire in a short time. For the purpose of provision.

  According to the first aspect of the present invention, X-rays emitted from the X-ray irradiating means are irradiated to a rim-attached tire in which a tire is attached to a rim, and X-rays transmitted through the rim-attached tire are detected by the X-ray detecting means. An assembly state measurement method for a rim-attached tire that detects and forms an X-ray transmission image by an image processing unit based on detected X-ray transmission information, and measures an assembly state of the rim and the tire, The rim assembly tire is rotated in a no-load state without a pressing load, the X-ray is irradiated in a tangential direction of the rim, and the X-ray detection means causes X of the assembly portion of the rim and the tire to be radiated. The line transmission information is captured at a predetermined timing, and based on the X-ray transmission information, a tangential direction transmission image is formed by the image processing means, and the rim and the specific part of the tire are used by using the tangential direction transmission image. Get location information It is characterized in.

  In the first aspect of the present invention, X-rays are radiated from the X-ray irradiation means in the tangential direction of the rim of the rim assembly tire, and X-rays transmitted through the rim tangential direction are detected and detected by the X-ray detection means. Based on the obtained X-ray transmission information, one tangential direction transmission image can be obtained by the image processing means.

  Thus, by analyzing the obtained tangential direction transmission image, it is possible to obtain positional information of the specific portion of the rim and the tire in the unloaded state of the rim-assembled tire. Further, since only a tangential direction transmission image is obtained, complicated image processing as in a CT scan is not necessary. Therefore, it is possible to measure a specific portion of the rim and the tire continuously in a short time over one round of the tire.

  According to a second aspect of the present invention, in the assembled state measuring method for a rim assembled tire according to the first aspect, the specific portion of the rim is a first measurement point provided on the outer surface of the rim flange of the rim. The specific portion of the tire is a second measurement point provided on the inner surface of the bead core of the tire, and the first measurement point and the second measurement point on a plane parallel to the rotation axis of the rim-attached tire. It is characterized by measuring the distance.

In the invention according to claim 2, distance information between the first measurement point provided on the outer side surface of the rim flange of the rim and the second measurement point provided on the inner side surface of the bead core of the tire is obtained as a tangential direction transmission image. Is obtained at a predetermined timing.
Thereby, in the rim-assembled tire, the distance between the first measurement point and the second measurement point, which are specific parts, is continuously measured over the entire circumference of the tire to evaluate the assembled state of the rim and the tire. it can.

According to a third aspect of the present invention, in the method for measuring an assembled state of the rim assembled tire according to the first aspect, the specific part of the rim and the tire is a gap generated between the rim and the tire. , Measuring the area of the gap.
In the invention according to claim 3, the area information of the gap formed between the rim and the tire is obtained at a predetermined timing using the tangential direction transmission image.
Thereby, in the rim-assembled tire, the area of the gap formed between the rim, which is a specific portion, and the tire can be continuously measured over the entire circumference of the tire to evaluate the assembled state of the rim and the tire.

  As described above, according to the present invention, it is possible to provide a method for measuring an assembled state of a rim-attached tire that can continuously measure the assembled state of the rim and the tire over a circumference of the tire in a short time.

  Hereinafter, the assembled state measuring method of the rim assembled tire of the present invention will be described with reference to FIG.

  The tire internal structure measuring device 10 used in the method for measuring the assembled state of a rim-attached tire is a device that uses an X-ray fluoroscopic device “tire inspection system with wheels MU2000” manufactured by Exlon International Co., Ltd. for the X-ray fluoroscopic part. is there.

  The tire internal structure measuring device 10 is provided perpendicularly to the floor surface and a tire travel rotation mechanism 16 that rotates the rim assembly tire 12 in a state in which the rim assembly tire 12 as a test object is rotatably supported. X-rays including a column 21, an X-ray irradiation device support 25 attached to the column 21, an X-ray tube supported by the X-ray irradiation device support 25 and emitting X-rays in a cone shape from a point-like focus An X-ray detection device 22 that is disposed opposite to the X-ray irradiation device 20 with the irradiation device 20 and the rim assembly tire 12 interposed therebetween, is supported by a support (not shown), and detects X-rays emitted from the X-ray irradiation device 20. A tire support 27 that is attached to the support column 21 and rotatably supports the rim-attached tire 12, a load load mechanism support tool 29 that is attached to the support column 21 and supports the load load mechanism 14, and a load load mechanism support tool 29 so It is lifting and a load loading mechanism 14 to apply a load of a load to the rim assembling the tire 12.

  Further, the tire internal structure measuring device 10 includes a tire internal pressure varying mechanism 18 that varies the pressure of air in the rim assembled tire 12, a tire rotational speed detector 24 that detects the rotational speed of the rim assembled tire, and a load load. A drive control unit 26 that performs drive control of the mechanism 14, the tire running rotation mechanism 16, the tire internal pressure variable mechanism 18, and the X-ray irradiation apparatus support 25, and X-ray output control from the X-ray irradiation apparatus 20, and an X-ray detection apparatus And an image formation processing unit 28 that forms an X-ray transmission image based on the X-ray transmission information detected at 22.

A rim assembly tire 12 in which a tire 56 is assembled to the rim 30 is rotatably supported at the tip of an arm 23 extending in the horizontal direction from the tire support 27.
The tire travel rotation mechanism 16 is a mechanism for rotating the rim assembly tire 12, and the belt mechanism 34 is disposed at a position in contact with the ground contact surface of the tire 56 in the rim assembly tire 12. The belt mechanism 34 is provided between the two pulleys 36, 38 and the pulleys 36, 38, contacts the ground contact surface of the rim assembly tire 12, is wound in the contact state, and rotates the rim assembly tire 12. A belt member 40 is provided. The belt member 40 is driven by the motor 44 by driving the pulley 38 via the belt 42.

  The rim assembled tire 12 is provided with a tire rotation speed detector 24, and the traveling speed of the tire traveling rotation mechanism 16 is controlled by the tire rotation speed information detected by the tire rotation speed detector 24.

The X-ray irradiation device 20 irradiates X-rays in the tangential direction of the rim 30 of the rim assembly tire 12. The drive control unit 26 controls the X-ray irradiation output, the X-ray irradiation timing, the output timing of the X-ray transmission information detected by the X-ray detection device 22, and the like.
The X-ray detection device 22 has a flat X-ray detection surface and detects the amount of X-ray transmitted through the rim assembly tire 12. Examples of such an X-ray detection device 22 include an image intensifier and a flat panel detector. Further, an X-ray film may be used in place of the X-ray detector 22.
In the present embodiment, in order to reduce the distortion of the X-ray transmission image, the central axis of the X-ray irradiated from the X-ray irradiation device 20 is set to be perpendicular to the X-ray detection surface of the X-ray detection device 22. ing.

Since the load-load mechanism 14 that applies a pressing load to the rim assembly tire 12 is not used in the measurement method of the present invention, a detailed description thereof is omitted.
The tire internal pressure variable mechanism 18 is a mechanism for supplying air from the air nozzle 74 to the rim-attached tire 12 when the rim-attached tire 12 stops rotating, and has an air pump 76.
The drive control unit 26 includes a motor 44 for the belt mechanism 34, a motor 72 for the load / load mechanism 14, a drive controller 78 that controls the drive of the air pump 76 that injects air into the tire 12, and X-ray irradiation from the X-ray irradiation device 20. And a control unit 80 that performs output control.

  The image formation processing unit 28 generates a tangential direction transmission image based on the X-ray transmission information detected by the X-ray detection device 22, and a computer 82 constituted by a microcomputer or the like and the X-ray transmission information. A data collection unit 84 to collect, a preprocessing unit 86 for preprocessing X-ray transmission information, a reconstruction unit 88 for reconstructing preprocessed X-ray transmission information, an image memory unit 90, and a CRT for displaying a tangential direction transmission image The display device 92 includes an auxiliary storage device 94 that stores the generated image.

  Here, the data collection unit 84 collects the X-ray transmission information detected by the X-ray detection device 22 in accordance with the data collection signal supplied from the control unit 80 via the computer 82.

  The preprocessing unit 86 performs preprocessing such as correction on the X-ray transmission information supplied from the data collection unit 84 to the computer 82 under the control of the computer 82. The X-ray transmission information preprocessed by the preprocessing unit 86 is temporarily stored in the image memory unit 90.

  The reconstruction unit 88 reconstructs a tangential direction transmission image based on the preprocessed X-ray transmission information. The reconstructed image data is stored in the auxiliary storage device 94 via the computer 82, supplied to the CRT display device 92, and displayed on the CRT display device 92 as a tangential direction transmission image.

Next, a procedure for measuring the assembled state of the rim assembled tire 12 using the tire internal structure measuring apparatus 10 will be described.
First, the rim assembly tire 12 is rotatably mounted on the arm 23 of the tire support 27. After the mounting, the air pump 76 is operated to supply air from the air nozzle 74 into the rim assembly tire 12 and adjust to a desired internal pressure.

  Next, the X-ray irradiation device 20 and the X-ray detection device 22 are disposed to face each other with the rim assembly tire 12 interposed therebetween. The X-ray irradiation device 20 and the X-ray detection device 22 are adjusted to positions where a transmission image in the tangential direction of the rim 30 in the rim-attached tire 12 is obtained, and are fixed.

The motor 44 is operated to drive the belt member 40 via the belt 42, and the belt member 40 is driven to rotate the rim assembly tire 12 at a predetermined rotational speed in a no-load state.
The rotation speed of the rim-assembled tire 12 is detected by the tire rotation speed detector 24, and the detection result is output to the control unit 80 via the drive controller 78 as a pulse signal corresponding to the rotation speed. Thereby, the rotational speed of the rim assembly tire 12 can be detected, and the rotational speed is controlled to be a predetermined speed.

Next, X-rays are irradiated from the X-ray irradiation apparatus 20 at a predetermined timing toward the tangential direction of the rim 30. At the same time, X-rays transmitted through the rim built-in tire 12 are detected by the X-ray detection device 22, and X-ray transmission information is output to the image forming processing unit 28.
The X-ray transmission information captured by the image forming processing unit 28 is continuously processed at a predetermined timing according to the processing means described above, and the processing result is sequentially stored as a tangential direction transmission image of the assembled state of the rim and the tire. 94 and displayed on the CRT display device 92.

The tangential direction transmission image obtained by the above procedure shows the assembled state of the rim 30, the rim flange 52, the bead 54, and the tire 56 in the tangential direction of the rim 30 irradiated with X-rays, as shown in FIG. Therefore, the position information can be obtained.
As a result, the assembled state of the rim and the tire is recorded in a short time as a tangential direction transmission image for one turn of the rim built-in tire 12.

  Note that the X-ray transmission information capture timing from the X-ray detection device 22 to the image forming processing unit 28 is such that the rotational speed of the rim built-in tire 12 is too fast, or the X-ray transmission information capture frequency is too small. Data is dull and unfavorable. On the other hand, even if the rotational speed of the rim built-in tire 12 is too slow, it takes a long time for measurement, which is not preferable.

  For this reason, it is appropriate that the rim-incorporated tire 12 has a rotational speed of 12 seconds for one rotation and an X-ray transmission information capturing frequency of 30 frames / second. As a result, each time the rim built-in tire 12 rotates once, 360 tangential direction transmission images are created, one round.

Next, a method of measuring and evaluating the assembled state of the bead core 54 using the created tangential direction transmission image will be described.
The bead core 54 is a member that fixes the tire 56 to the rim 30 and needs to be attached at a predetermined position in a predetermined state. The attachment state of the bead core 54 is evaluated by measuring the relative position between the bead core 54 and the rim flange 52.

As shown in FIG. 3, first, a first specific portion L1 is provided on the outer surface (in the direction of arrow B) of the rim flange 52, and a second specific portion is provided on the inner surface (in the direction of arrow A) of the bead core 54. L2 is provided.
Next, the distance L between the first specific part L1 and the second specific part L2 on the plane (P1 or P2) parallel to the rotation axis of the rim built-in tire 12 displayed on the screen is obtained from the coordinates. .

  Finally, a reference sample with known dimensions is measured under the same conditions, and the distance L on the tangential transmission image actually obtained by using the reference data of the tangential transmission image obtained in advance is measured. The value of is converted into the actual size value. By this conversion work, not the distance on the image, but the distance L between the actual first specific part L1 and the second specific part L2 of the rim built-in tire 12 can be obtained.

  Here, a method of automatically extracting the positions of the first specific portion L1 and the second specific portion L2 on 360 tangential direction transmission images obtained over the entire circumference of the tire includes a tangential direction transmission image. The pattern recognition using shading (brightness difference) on the screen is used.

  That is, the rim flange 52 is made of an aluminum alloy and hardly transmits X-rays, so that the rim flange 52 is expressed in black on the tangential direction transmission image. On the other hand, the outside of the rim flange 52 is a space and transmits X-rays well, so that it is expressed in white on the tangential direction transmission image. Using this difference in shading, an intersection of a surface P1 formed on the image parallel to the rotation axis of the rim-incorporating tire 12 and a boundary where the left side is black and the right side is white is defined as a first specific portion L1.

Similarly, since the bead core 54 is made of steel wire and hardly transmits X-rays, the bead core 54 is photographed black on the tangential direction transmission image, and the surrounding tire 56 is photographed lightly black because it transmits X-rays. Using the shading on the screen, a plane P2 is formed parallel to the rotation axis of the rim-incorporating tire 12 in which the bead core 54 is present, and an intersection with the boundary where the left side is dark and the right side is black is defined as the second specific portion L2. It is said.
By performing the same process continuously for one round of the tire, an image between the specific parts of the rim and the tire assembly portion can be acquired for one round of the tire.

  FIG. 4 shows a tangential direction transmission image obtained by irradiating X-rays with a reference sample having a known size described above, and measuring the displacement amount of the bead core 54 using the obtained tangential direction transmission image. An example of measurement is shown.

  The horizontal axis in FIG. 4 indicates the position of the entire tire circumference in terms of an angle (deg) from the starting position, and the vertical axis indicates the amount of displacement of the distance between the specific position of the rim flange 52 and the specific position of the bead core 54. (Mm) is shown. In the vertical axis, the plus side indicates a state where the bead core 54 is displaced toward the inside of the tire (in the direction of arrow A), and the minus side indicates a state where the bead core 54 is displaced toward the outside of the tire (in the direction of arrow B).

  The measurement results shown in FIG. 4 were obtained by inserting a reference sample (metal plate, thickness 2 mm, 3 mm) into a part of the inside of the bead core 54 and measuring the displacement amount of the bead core 54 over the entire circumference of the tire by the above procedure. It is the result in the condition. A solid line 96 is a characteristic of a 3 mm metal plate, and a broken line 98 is a characteristic of a 2 mm metal plate.

  As shown in FIG. 4, the solid line 96 and the broken line 98 both show the maximum amount of displacement inside the bead core 54 at the position where the metal plate is inserted (position of 225 (deg) on the horizontal axis). In addition, in the range of 180 to 270 (deg) on the horizontal axis, the influence of inserting the metal plate appears, but in the range excluding this range, the displacement amount of the bead core 54 has changed around zero, and the large displacement is can not see. From this, it can be said that when a deviation occurs in the bead core 54, a displacement occurs at the deviation position, and the position where the displacement occurs can be measured accurately.

  Further, the displacement amount of the bead core 54 obtained from the tangential direction transmission image at this time is about 1.9 mm at the solid line 96 when the inserted metal plate is 3 mm thick, and when the inserted metal plate is 2 mm thick. Indicates about 1.2 mm in a broken line 98.

  When this measurement result is compared with the actual size of the reference sample, as shown in FIG. 5, there is a strong correlation between the actual size of the reference sample and the displacement amount of the bead core 54 obtained from the measurement result (contribution rate 95. 8%). From this, it can be said that the bead core displacement can be accurately measured by appropriately correcting the measurement value obtained from the tangential direction transmission image.

Next, a method for measuring the area of the gap generated between the rim and the tire using a tangential direction transmission image will be described.
As shown in FIG. 6, a gap S is generated between the corner portion formed by the rising portions of the rim 30 and the rim flange 52 and the corner portion of the tire 56 due to deformation caused by the tire 56 being subjected to air pressure. The gap S is desirably small, and the area needs to be measured and evaluated.

  In the tangential direction transmission image, the gap S is photographed white because X-rays are transmitted, and the rim flange 52 and the tire 56 around the gap S are photographed black because they are difficult to transmit X-rays. Using the shading (luminance difference) on the tangential direction transmission image, the gap S and the surroundings can be easily distinguished.

  First, a measurement range is defined on the tangential direction transmission image. Specifically, as shown in FIG. 6, a region 60 centering on a corner where the rim flange 52 rises from the rim 30 is defined. As shown in FIG. 7A, on the tangential direction transmission image, a region with high brightness (shaded portion) is generated in addition to the region indicated by the broken line 60. Therefore, such a region is analyzed. This is because it is excluded from the target.

Next, as shown in FIG. 7B, the gap S is set as a target using an appropriate threshold value from luminance information in the photographed broken line 60 using the fact that the image is white in the tangential direction transmission image. The gap S and other portions are binarized and divided.
Next, as shown in FIG. 7C, the number of dots in the white part constituting the divided gap S is obtained. The area of the actual gap S can be calculated by calibrating the measurement result by comparing the number of dots of the gap S obtained from the actual measurement result with the number of dots constituting the reference area obtained in advance.
The same process is continuously performed for one round of the tire. Thus, the gap S between the rim and the tire mounting portion can be continuously measured and evaluated over the entire circumference of the tire.

  In this embodiment, the displacement amount of the position of the bead core 54 in the rim-assembled tire 12 and the area of the gap S generated between the rising portion of the rim flange 52 and the tire 56 were measured and evaluated. However, the present invention is not limited to these, and if there is a difference in the transmittance of X-rays, other portions can be measured and evaluated.

It is a lineblock diagram of a tire internal structure measuring device concerning one embodiment of the present invention. It is a figure which shows the tangential direction transmission image of a rim | limb assembly | attachment tire. It is a figure which shows the method of measuring the distance of a bead core position and a rim flange from a tangential direction transmission image. It is a figure which shows the example of a measurement of the distance between a bead core position and a rim flange from a tangential direction transmission image. It is a figure which shows the relationship between a metal plate thickness and a bead core displacement amount. It is a figure which shows the method of measuring the clearance gap formed by the standup | rising corner | angular part of a rim flange, and a tire from a tangential direction transmission image. It is a figure which shows the method of calculating | requiring the area of the clearance gap which can be made by the standup | rising angle part of a rim flange, and a tire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tire internal structure measuring device 12 Rim | attachment tire 20 X-ray irradiation means (X-ray irradiation apparatus)
22 X-ray detection means (X-ray detection device)
28 Image processing means (image formation processing section)
30 rim 52 rim flange 54 bead core 56 tire L1 first measurement point L2 second measurement point
S Clearance created between the rim flange riser and the tire

Claims (3)

The X-ray irradiating means irradiates X-rays from the X-ray irradiating means to the rim-attached tire in which the tire is assembled to the rim, and the X-ray detecting means detects the X-rays transmitted through the rim-attached tire. An assembled state measuring method for a rim-attached tire, wherein an X-ray transmission image is formed by an image processing means, and an assembled state of the rim and the tire is measured,
The rim assembly tire is rotated in a no-load state without a pressing load,
Irradiating the X-ray in the tangential direction of the rim;
By the X-ray detection means, X-ray transmission information of the assembly part of the rim and the tire is captured at a predetermined timing,
Based on the X-ray transmission information, the image processing means forms a tangential direction transmission image,
Using the tangential direction transmission image, position information of a specific part of the rim and the tire is obtained. The specific part of the rim is a first measurement point provided on the outer surface of the rim flange of the rim,
The specific part of the tire is a second measurement point provided on the inner surface of the bead core of the tire,
2. The assembly of a rim assembly tire according to claim 1, wherein a distance between the first measurement point and the second measurement point on a plane parallel to the rotation axis of the rim assembly tire is measured. State measurement method. The specific part of the rim and the tire is a gap generated between the rim and the tire,
The method for measuring an assembled state of a rim-attached tire according to claim 1, wherein an area of the gap is measured.

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