JP5367617B2 - CT equipment for tires - Google Patents

Description

  The present invention relates to a tire CT (Computed Tomography) apparatus that obtains a cross-sectional image of a tire under load by X-rays.

Such a tire CT apparatus transmits X while being absorbed by irradiating the X-ray emitted from the X-ray tube to the tire in a loaded state when the load plate of the load device is pressed against the tire held on the rotating shaft. A line is detected by an X-ray detector, a transmission image is acquired in all directions, image processing is performed, and a cross-sectional image of the tire is reconstructed.
As this type of tire CT apparatus, there is an example of a patent application previously applied (see Patent Document 1).

Japanese Patent Laid-Open No. 06-218844 (paragraph [0030], drawing FIG. 17)

In the tire CT apparatus disclosed in Patent Document 1, a wheel center portion of a tire to which a commercially available wheel is attached is fixed to an end surface of a support portion protruding in a conical shape of the holder, and the tire is rotatably held together with the holder. A tire holding device is provided.
Further, a tire pressure device is provided in which a rectangular pressure plate that applies a load to the tire on the side of the tire is supported on both sides so as to be able to contact and separate from the tire.

The tire holding device and the tire loading device are provided on a rotary table and rotate together.
An X-ray tube and an X-ray detector are disposed opposite to each other on the outer side of the rotating tire holding device and the tire loading device.

  The tire was positioned so that the desired cross section of the tire coincided with the horizontal plane forming the fan angle of the X-ray beam emitted from the X-ray tube, and the pressure plate was pressed against the tire outer tread by the load device to simulate the actual road. As the load state, the tire holding device and the tire load device are rotated to collect a transmission image by X-ray irradiation, and image processing is performed to reconstruct a cross-sectional image of the tire.

  In Patent Document 1, the pressure plate that presses the tire uses a thin rectangular plate as it is necessary to reduce the material thickness at the tomographic plane of the pressure plate in order to improve the transmission of X-rays. Since the power is applied to both sides of the rectangular pressure plate and the central portion presses the tire, it is considered that the pressure plate is made of a steel plate as a thin plate having strength and rigidity that is not damaged by pressing.

Furthermore, it is disclosed that the pressure plate is not only thin, but also has a groove surface, hole processing or honeycomb processing on the plate surface because it is necessary to reduce the X-ray transmission thickness without reducing the strength. Therefore, it is assumed that the pressure plate that can be processed to ensure strength and rigidity is substantially made of a steel plate.
If it is not made of a steel plate, it will be made of metal that is thicker than a certain degree.

If the pressure plate pressed against the outer circumferential tread of the tire is made of a steel plate or a metal having a thickness, the X-ray is absorbed by the pressure plate and the X-ray transmittance is reduced. The interface between the pressing surface and the tire becomes unclear, which hinders detailed consideration of tire deformation.
In addition, since the tire is held by fixing the center part of the wheel attached to the tire to the support part protruding in the conical shape of the holder, there is also a support part of the metal holder in the center part of the tire. X-ray transmittance is reduced and the sharpness of the cross-sectional image is lowered.

  The present invention has been made in view of the above points, and the object of the present invention is that the X-ray is hardly absorbed by a load member having sufficient strength and applying a load to the tire, and the tire in a loaded state is clear. The point is to provide a tire CT apparatus capable of obtaining a cross-sectional image.

  In order to achieve the above object, an invention according to claim 1 includes a tire holding device that holds a tire, a tire load device that presses a load member against an outer circumferential tread surface of the tire held by the tire holding device, and a tire. An X-ray CT apparatus including an X-ray CT apparatus that irradiates X-rays and detects transmitted X-rays to obtain a cross-sectional image of a tire. Is a CT apparatus for tires, which is configured to be fixed to a thin plate structure formed by processing a thin plate made of aluminum or a carbon composite material.

  According to a second aspect of the present invention, in the CT apparatus for a tire according to the first aspect, the thin plate structure is formed by bending the thin plate member into a rectangular C-shaped cross section, and an opening of an internal cavity of the thin plate structure. The tread plate is fixed to the outer surface of the central plate portion facing each other, and the load member is configured.

  According to a third aspect of the present invention, in the tire CT apparatus according to the first or second aspect, the tire holding device is configured by fitting an annular hub plate to a cylindrical hollow shaft, The mounted rim is fixed and held on the hub plate.

  According to a fourth aspect of the present invention, in the tire CT apparatus according to any one of the first to third aspects, the X-ray CT apparatus irradiates X-rays with an X-ray energy in the vicinity of 450 KeV. To do.

According to the tire CT apparatus of claim 1, the load is configured such that the tread plate made of a wooden board in contact with the tire is fixed to a thin plate structure formed by processing a thin plate made of aluminum or a carbon composite material. Since the member is pressed against the outer peripheral tread surface of the tire held by the tire holding device, the tread plate that presses the tire in contact with the tire of the load member is difficult to absorb X-rays by the wooden board and has high X-ray transmittance. In the X-ray cross-sectional image, the interface between the pressing surface of the tread plate that presses the tire and the tread surface of the tire becomes clear, and the deformation of the tire can be considered in detail.
The thin plate structure that firmly supports and supports the tread plate has a strength that does not cause deformation or breakage even if the tread plate is processed and structurally pressed against the tire while maintaining a high X-ray transmittance by using a thin plate material. Rigidity can be ensured.

  According to the tire CT apparatus of claim 2, the load member is configured by fixing the tread plate to the outer surface of the central plate portion of the thin plate structure formed by bending a thin plate material into a rectangular C-shaped cross section. Therefore, the load member itself composed of a thin plate structure having high strength and rigidity and a wooden tread board hardly absorbs X-rays and has high X-ray transmittance, so that a clear sectional image of a tire in a loaded state is obtained. be able to.

According to the tire CT apparatus of the third aspect, the tire holding device is configured by fitting the annular hub plate to the cylindrical hollow shaft, and the tire is held by fixing the mounted rim to the hub plate. Therefore, the support shaft at the center of the tire is a hollow shaft and has a high X-ray transmittance, so that a clear sectional image of the entire tire can be obtained.
Since the tire is fixed and held on the hub with the rim mounted, a commercially available rim can be used with the hub.

  According to the tire CT apparatus of the fourth aspect, a clear cross-sectional image of a tire in a loaded state can be obtained even if the X-rays irradiated by the X-ray CT apparatus are low energy X-rays in the vicinity of 450 KeV. .

1 is a schematic overall view of a tire CT apparatus according to an embodiment of the present invention. It is a disassembled perspective view of the hollow shaft and tire hub which hold | maintain a tire. It is the side view made into the partial cross section of the state in which the hollow shaft and the hub hold | maintained the tire. It is a perspective view of a load member. It is a perspective view which shows the relative positional relationship of the tire and tread board (and load member) supported by the hollow shaft. It is a top view which shows the relative positional relationship of the X-ray tube and X-ray detector with respect to a tire and a load member. It is a figure which shows the example of the cross-sectional image obtained by the X-ray CT apparatus. It is a figure which shows the cross-sectional image which expanded the principal part of the cross-sectional image of FIG.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
A schematic overall view of a tire CT apparatus 1 according to the present embodiment is shown in FIG.
The tire holding device 10 and the tire loading device 20 are arranged in the center, and the X-ray tube 31 and the X-ray detector 35 of the X-ray CT device 30 are arranged on both the front and rear sides with the tire holding device 10 and the tire loading device 20 interposed therebetween. It is installed.

  In the present embodiment, the direction with the X-ray detector 35 viewed from the X-ray tube 31 is defined as the front, the opposite direction is defined as the rear, the right-handed direction is directed rightward, and the left-handed direction is determined leftward I will keep it.

A pair of rails 11 and 11 are laid in the left-right direction on the floor surface between the X-ray tube 31 and the X-ray detector 35, and the tire holding device 10 moves horizontally on the rails 11 and 11 horizontally. It is mounted on a turntable 13 that is rotatably mounted on a base 12 via a support base 14.
Side walls 15 and 16 are erected on the support base 14 so as to face each other.

The side walls 15 and 16 are shell bodies having a hollow inside, and the upper side and the lower side are widened and gradually become narrower toward the central parts 15c and 16c, and the central parts 15c and 16c are made narrower. Is formed.
A hollow shaft 17 is installed between the central portions 15c, 16c of the side walls 15, 16, and the rim 5 attached to the tire T is fixed to the hub 18 fitted to the hollow shaft 17, so that the tire T is held in a vertical posture. The
Since it is attached to the hub 18, a commercially available rim 5 can be used.

As shown in FIG. 2, the hollow shaft 17 is cylindrical and has small holes 17h arranged in the axial direction.
On the other hand, the hub 18 has a shape in which an inner cylindrical portion 18i and an outer cylindrical portion 18o extend from the inner peripheral edge and the outer peripheral edge of the hollow disc portion 18a, respectively, and a small hole 18h is drilled in the inner cylindrical portion 18i. Yes.
Male screws 18p and 18p project from the symmetrical positions with respect to the center of the hollow disc portion 18a.

As shown in FIG. 3, the hollow shaft 17 penetrates into the inner cylindrical portion 18i of the hub 18, and the small holes 17h and 18h are matched at a predetermined position to insert and fix a pin or the like.
The rim 5 mounted on the tire T is opposed to the hollow disc portion 18a of the hub 18, and the mounting holes of the rim 5 are brought into contact with the male screws 18p and 18p so that the nuts 19 and 19 are screwed into the male screws 18p and 18p. Thus, the tightening tire T is held.

  When the tire T is mounted, the hollow shaft 17 is cantilevered on one side wall 15 and the tire T is held on the hub 18 via the rim 5 and then moved in the axial direction to move the hollow shaft 17. Is also supported on the side wall 16 to support both ends.

  Accordingly, the tire T held in the vertical posture by the tire holding device 10 rotates with the rotation of the turntable 13 around the vertical line passing through the approximate center of the tire T as the rotation center axis L (see FIG. 3). It can be moved horizontally in the left-right direction by linear movement.

A tire load device 20 is provided on the side of the tire T between the side walls 15 and 16 to apply a load by pressing the load member 21 against the outer tread surface of the tire T.
The load member 21 is configured such that a tread plate 22 made of a wooden plate in contact with the tire T is fixed to a thin plate structure 25 formed by processing a thin plate material 26 made of aluminum (see FIG. 4). .

As shown in FIG. 4, the tread board 22 made of a wooden board is a rectangular plate, and the thin plate structure 25 is a vertically long structure obtained by bending a thin plate material 26 made of aluminum into a rectangular C-shaped section. Two rectangular reinforcing plates 27 are interposed between the upper and lower portions of the inner cavity for reinforcement.
The thin plate structure 25 may be formed by bending a thin plate material made of a carbon composite material.
The thin plate structure 25 whose cross section is bent into a rectangular C shape and is long in the vertical direction is arranged with the central plate portion 26p facing the long opening 28 in the vertical direction with the internal cavity open facing the tire T.

The tread plate 22 is fixed to the upper and lower intermediate positions of the outer surface of the central plate portion 26p facing the tire T of the thin plate structure 25.
Therefore, the tread plate 22 fixed to the central plate portion 26p of the thin plate structure 25 is opposed to the outer tread surface of the tire T held in the tire holding device 10 in a vertical posture.
The thin plate structure 25 is made of an aluminum thin plate material 26, and is a structure having a cross-section bent into a rectangular C shape. Therefore, the thin plate structure 25 is structurally high in strength and rigidity, and has strength and rigidity by the reinforcing plates 27 interposed vertically. Sufficient rigidity is secured.

The thin plate structure 25 to which the tread plate 22 is fixed can move and change its position relative to the tire T held by the tire holding device 10.
Now, referring to FIG. 5, if the center axis direction of the tire T is the X axis direction, the direction in which the tread plate 22 approaches or separates from the tire T is the Y axis direction, and the vertical direction is the Z axis direction, a thin plate structure The body 25 can move in any of the X-axis direction, the Y-axis direction, and the Z-axis direction.

By moving the thin plate structure 25 in the Y-axis direction, it is possible to simulate a state where the tread plate 22 is pressed against the tire T and the tire T supporting the vehicle body is deformed while contacting the road surface.
The state of the tire T during cornering is simulated by moving the tread plate 22 in the X-axis direction with the tread plate 22 pressing the tire T, and the Z-axis direction with the tread plate 22 pressing the tire T By moving the tread plate 22 at the same time, it is possible to simulate the state of the tire T at the time of braking or starting.

Further, the posture of the tread plate 22 with respect to the tire T can be changed by rotating the thin plate structure 25 about the Z axis.
That is, by rotating the tread plate 22 around the Z-axis, the camber angle at which the tire T contacts the tread plate 22 can be changed, and the state of the tire T at the time of various runnings at each camber angle is simulated. can do.
A driving mechanism for moving or rotating the thin plate structure 25 together with the tread plate 22 in the three axis directions of the X axis, the Y axis, and the Z axis is omitted from FIG. It has been.

At the rear of the tire holding device 10 and the tire loading device 10 described above, nut members 34n and 34n at both ends are screwed to a pair of left and right screw rods 33 and 33 which are erected freely on the left and right support columns 32 and 32, respectively. An elevating member 34 is installed, and an X-ray tube 31 is attached to the elevating member 34.
Therefore, when the screw rods 33 and 33 are rotated, the elevating member 34 is moved up and down together with the X-ray tube 31 via the nut members 34n and 34n.

On the other hand, in front of the tire holding device 10 and the tire load device 10, nut members 38n and 38n at both ends are screwed to a pair of left and right screw rods 37 and 37 that are rotatably raised on the left and right support columns 36 and 36, respectively. An elevating member 38 is installed, and an X-ray detector 35 is attached to the elevating member 38.
Accordingly, when the screw rods 37 and 37 are rotated, the elevating member 38 is moved up and down together with the X-ray detector 35 via the nut members 38n and 38n.

The X-ray tube 31 and the X-ray detector 35 are moved up and down synchronously and are always kept at the same height position, and the X-ray detector 35 can receive and detect the X-ray emitted from the X-ray tube 31. .
6 shows that the X-ray tube 31 and the X-ray detector 35 are at the same height as the center axis (hollow shaft 17) of the tire T, and the rotation center axis L passing through the approximate center of the tire T by the turntable 13 is Relative positional relationship between the X-ray tube 31 and the X-ray detector 35 with respect to the tire T and the load member 21 when the tire T is positioned at a lateral movement position that intersects with a vertical line from the X-ray tube 31 to the X-ray detector 35 Is shown in a top view.

The tire T that rotates about the rotation center axis L is substantially included in the fan angle α of the X-ray emitted from the X-ray tube 31, and the tire T and its periphery are included in the scanning area A. .
Therefore, the tread plate 22 that presses the tire T together with the tire T is also displayed as a cross-sectional image.

The X-ray CT apparatus 30 emits X-rays from the X-ray tube 31 toward the tire T rotating about the rotation center axis L with X-ray energy of 450 KeV at a fan angle α.
7 and 8 show cross-sectional images obtained by acquiring a large number of transmission image data in one rotation of the tire T and reconstructing the data by performing data processing in this way.
FIG. 8 is an enlarged view of the main part of the entire cross-sectional image of FIG.

As shown in FIGS. 7 and 8, a clear cross-sectional image in which the cross-sectional shape of the tire T is clearly understood is obtained.
In the entire cross-sectional image shown in FIG. 7, it is clear that one of the two cross-sectional images of the tire T shown at a substantially symmetrical position is pressed by the tread plate 22 and deformed flatter than the other. In the enlarged cross-sectional image of the main part shown in FIG. 8, the interface between the tread surface of the tire T and the pressing surface of the tread plate 22 is clearly shown.

Despite the X-ray CT apparatus 30 irradiating X-rays with an X-ray energy as low as 450 KeV, the sharpness of the cross-sectional image is high because of the tread plate 22 of the load member 21 that presses the tire T. Is made of wood, and the thin plate structure 25 is formed by bending an aluminum thin plate material 26 into a rectangular C-shaped cross section, so that the load member 21 hardly absorbs X-rays and has high X-ray transmittance. .
In addition, since the reinforcing plate 27 that reinforces the thin plate structure 25 is located above and below the height position of the tire T irradiated with X-rays, the X-ray transmittance is not reduced.

Furthermore, the fact that the central support shaft that supports the tire T is a cylindrical hollow shaft 17 also increases the X-ray transmittance.
Note that the narrow side walls 15 and 16 and the central portions 15c and 16c that support the hollow shaft 17 with the hollow shells also contribute to increasing the X-ray transmittance.

In particular, since the tread plate 22 that is pressed against the tire T is made of wood having an extremely high X-ray transmittance, the tread surface of the tire T and the pressing surface of the tread plate 22 are shown in the enlarged cross-sectional image of the main part in FIG. The interface with is clear and the deformation of the tire can be clearly seen.
Therefore, the shape of the tire T when simulating various traveling times can be considered in detail.

  In the present CT apparatus for tire 1, the X-ray energy capable of obtaining a clear cross-sectional image in which the cross-sectional shape of the tire T can be clearly obtained is about 450 KeV, and for a tire on which a tire load device is mounted on a conventional tire holding device. The CT apparatus can significantly reduce the X-ray energy and reduce the cost as compared with a CT apparatus that requires a high X-ray energy of 3 MeV or more.

  The thin plate structure 25 that firmly supports the tread plate 22 has a strength that does not cause deformation or breakage even if it is processed and structurally pressed against the tire T while maintaining a high X-ray transmittance by using a thin plate material 26. And ensure the rigidity.

T ... tyre, A ... scanning area,
1 ... CT device for tire, 5 ... rim,
10 ... Tire holding device, 11 ... rail, 12 ... moving table, 13 ... turntable, 14 ... support table, 15, 16 ... side wall, 17 ... hollow shaft, 18 ... hub, 19 ... nut,
20 ... Tire load device, 21 ... Load member, 22 ... Tread plate, 25 ... Thin plate structure, 26 ... Thin plate material, 26p ... Central plate part, 27 ... Reinforcement plate, 28 ... Opening,
30 ... X-ray CT apparatus, 31 ... X-ray tube, 32 ... support, 33 ... screw rod, 34 ... elevating member, 35 ... X-ray detector, 36 ... support, 37 ... screw rod, 38 ... elevating member.

Claims (4)

A tire holding device that holds a tire, a tire load device that presses a load member against an outer peripheral tread surface of the tire held by the tire holding device, and a cross-sectional image of the tire by detecting transmitted X-rays by irradiating the tire with X-rays In a tire CT apparatus comprising an X-ray CT apparatus for obtaining
The load member is configured such that a tread plate made of a wooden board that is in contact with an outer peripheral tread surface of a tire is fixed to a thin plate structure formed by processing a thin plate material made of aluminum or a carbon composite material. CT equipment for tires. The thin plate structure is formed by bending the thin plate material into a rectangular C-shaped cross section,
2. The tire CT apparatus according to claim 1, wherein the load member is configured by fixing the tread plate to an outer surface of a central plate portion facing an opening of an internal cavity of the thin plate structure. The tire holding device is configured by fitting an annular hub plate to a cylindrical hollow shaft,
The tire CT apparatus according to claim 1, wherein a rim on which the tire is mounted is fixed and held on the hub plate.   The tire X-ray CT apparatus according to any one of claims 1 to 3, wherein the X-ray CT apparatus irradiates X-rays with X-ray energy in the vicinity of 450 KeV.

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