JP7799459B2 - Tire Testing Equipment - Google Patents

Description

The present invention relates to a tire testing device.

Patent Document 1 discloses a tire testing device for measuring the running performance of a tire to be evaluated. The tire testing device has a running platform with which the tire to be evaluated comes into contact, and a tire support unit that supports the tire to be evaluated. The tire support unit rotatably supports a wheel on which the tire to be evaluated is mounted on a rim. Generally, in such testing devices, a hub rotatably attached to one end of a rotating shaft is fitted into a hub hole provided in the radial center of the wheel. A stud bolt provided in the hub extends in the direction of the rotation axis and protrudes toward the rim, and is inserted into a bolt insertion hole provided in the wheel and a nut is screwed into the hub to fasten the wheel to the wheel.

Japanese Patent Application Laid-Open No. 2019-163978

The tire support structure disclosed in Patent Document 1 has the risk of damaging the bolts used as fastening means if the wheel shifts in the rotational direction relative to the hub during sudden braking, but there is no disclosure of how to prevent rotational shift of the wheel relative to the hub.

The objective of the present invention is to provide a tire testing device that can easily resist misalignment of the wheel relative to the hub in the rotational direction under braking and driving conditions in the tire testing device, and that prevents damage to the fastening means that secures the wheel and hub.

One aspect of the present invention is
a running platform on which the test tire is brought into contact;
a wheel on which the tire to be evaluated is mounted on a rim;
a tire support unit having a hub to which the wheel is attached and rotatably supporting the tire to be evaluated via the wheel and the hub;
a plurality of fastening members that fasten the wheel to the hub at a plurality of positions in the tire circumferential direction,
the wheel has a wheel-side uneven portion that extends in the tire radial direction and has a predetermined cross-sectional shape that is uneven in the tire axial direction at one or more positions in the tire circumferential direction on a mounting surface that is attached to the hub,
the hub has a hub-side uneven portion that extends in the tire radial direction and has a predetermined cross-sectional shape that is uneven in the tire axial direction at one or more positions in the tire circumferential direction on a mounting surface to which the wheel is mounted,
The tire testing device provides a tire testing device in which the wheel-side concave-convex portion and the hub-side concave-convex portion form a complementary abutting concave-convex pair that abuts against each other in the tire axial direction.

This invention increases the contact area between the hub and wheel compared to when no unevenness is provided between the mounting surface of the hub and the mounting surface of the wheel. This increases the frictional force between the hub and wheel, making it easier to resist misalignment in the rotational direction of the hub and wheel under braking and driving conditions in a tire testing device, and preventing damage to the bolts securing them together.

The abutting concave-convex pair is
In the cross-sectional shape,
a first inclined side inclined toward one side in the tire circumferential direction;
and a second inclined side inclined toward one side in the tire axial direction toward the other side in the tire circumferential direction.

With this configuration, the first and second inclined edges provide radially extending inclined surfaces on both sides of the circumference, thereby increasing the frictional force between the hub and wheel regardless of the direction of tire rotation.

Furthermore, when the hub and wheel misalign in the rotational direction, for example, when the inclined surface formed by the first inclined edge of the hub and the inclined surface formed by the first inclined edge of the wheel move in the circumferential direction of the tire, a misalignment occurs between the hub and wheel, with one inclined surface climbing up the other inclined surface. At this time, the thickness between the hub and wheel increases by the amount that one inclined surface climbs up the other inclined surface, stretching the bolt by the amount of the increased thickness, and the elastic force generated at the same time increases the axial force. As a result, the axial force increases as the hub and wheel tend to misalign in the rotational direction, preventing misalignment between the hub and wheel in the rotational direction. This provides the so-called self-locking effect of the Nord-Lock washer.

In the cross-sectional shape,
the first inclined side is inclined at a first inclination angle with respect to a plane perpendicular to the tire axial direction,
the second inclined side is inclined at a second inclination angle with respect to a plane perpendicular to the tire axial direction,
The first tilt angle and the second tilt angle may be greater than or equal to 5° and less than or equal to 45°.

This configuration ensures the self-locking effect described above. If the first and second tilt angles are less than the bolt's lead angle, e.g., 5°, the bolt will loosen and an increase in axial tension will be impossible. If the first and second tilt angles are greater than 45°, the contact area between the hub-side uneven portion and the wheel-side uneven portion will decrease, making it difficult for the frictional force between the hub and wheel to increase.

In the cross-sectional shape,
the first inclined side is inclined at a first inclination angle with respect to a plane perpendicular to the tire axial direction,
the second inclined side is inclined at a second inclination angle with respect to a plane perpendicular to the tire axial direction,
The second tilt angle may be set to be larger than the first tilt angle.

The abutting concave-convex pair may extend spirally when viewed axially of the tire, with the inner side in the tire radial direction positioned to one side of the outer side in the tire rotation direction.

With this configuration, the distance from the radial inside to the radial outside is increased compared to when the contact concave-convex pair is arranged in a linear fashion, thereby increasing the contact area.

The abutting concave-convex pair is
It may be conical in shape with the tire rotation axis as its center.

With this configuration, the mounting surface of the hub and the mounting surface of the wheel are formed as inclined surfaces, which increases the contact area between the hub and the wheel compared to when the mounting surface and mounting surface are formed as flat surfaces. This further increases the frictional force between the hub and the wheel.

Another aspect of the present invention is
a running platform on which the test tire is brought into contact;
a wheel on which the tire to be evaluated is mounted on a rim;
a tire support unit having a hub to which the wheel is attached and rotatably supporting the tire to be evaluated via the wheel and the hub;
a plurality of fastening members that fasten the wheel to the hub at a plurality of positions in the tire circumferential direction,
the wheel has a wheel-side uneven portion on a mounting surface attached to the hub, the wheel having a predetermined cross-sectional shape that is uneven in the tire axial direction;
the hub has a hub-side uneven portion on a mounting surface to which the wheel is mounted, the hub having a predetermined cross-sectional shape that is uneven in the tire axial direction,
The wheel-side concave-convex portion and the hub-side concave-convex portion form a mating concave-convex pair that are complementary to each other so as to mate with each other in the tire axial direction.

According to the present invention, by fitting the hub and wheel in the tire axial direction, it is easier to resist rotational misalignment (shear force) between the two in the tire rotation direction. More specifically, the shear force caused by rotational misalignment between the hub and wheel in the rotation direction can be applied to the bolts and also borne by the mating concave-convex pair. Therefore, under braking and driving conditions in a tire testing device, it is easier to resist misalignment between the two in the rotation direction, and damage to the bolts securing the two is prevented.

It is preferable that the mating recess-projection pair is located at a position in the tire circumferential direction between the multiple fastening members.

This configuration makes it easier for the mating recess and protrusion pair to withstand the shear force acting on the bolt.

The fitting concave-convex pair is
In the cross-sectional shape,
a first inclined side inclined toward one side in the tire circumferential direction;
and a second inclined side inclined toward one side in the tire axial direction toward the other side in the tire circumferential direction.

This configuration prevents damage to the bolts that secure the hub and wheel with a simple structure that simply provides complementary mating recesses and protrusions on the hub and wheel. Furthermore, during assembly, the wheel can be guided by the V-shape formed by the first and second inclined edges, making it easy to assemble the wheel to the hub.

The mating recess-protrusion pair may have a rectangular cross-sectional shape.

This configuration achieves the same effects as those described above.

This invention makes it easier to resist misalignment of the wheel relative to the hub in the rotational direction under braking and driving conditions in a tire testing device, preventing damage to the fastening means that secures the wheel and hub.

1 is a schematic view of a tire testing device according to a first embodiment of the present invention. 2 is a schematic view of the tire testing device of FIG. 1 as viewed from the tire axial direction. FIG. FIG. 3 is an enlarged cross-sectional view of a main part taken along line III-III in FIG. FIG. 4 is an enlarged view of a main part as seen from the direction of arrow IV in FIG. 3 . FIG. 5 is a developed cross-sectional view taken along line VV in FIG. 4. FIG. 5 is a developed cross-sectional view taken along line VV in FIG. 4 according to a first modified example. FIG. 5 is a developed cross-sectional view taken along line VV in FIG. 4 according to a second modified example. FIG. 4 is an enlarged view of a main part according to a third modified example, as viewed from the direction of arrow IV in FIG. 3 . FIG. 10 is an enlarged cross-sectional view of a main part taken along line III-III in FIG. 1 according to a fourth modified example. FIG. 10 is an enlarged view of a main part of a tire testing device according to a second embodiment, as viewed from the tire axial direction. FIG. 11 is a developed cross-sectional view taken along line XI-XI in FIG. FIG. 11 is a developed cross-sectional view taken along line XI-XI in FIG. 10 according to a fifth modified example. FIG. 11 is an enlarged view of a main part of a tire testing device according to a third embodiment, as viewed from the tire axial direction. FIG. 14 is an enlarged cross-sectional view of a main part taken along line XIV-XIV in FIG. 13 . FIG. 14 is an enlarged view of a main part in FIG. 13 according to another modified example. FIG. 5 is a developed cross-sectional view taken along line VV in FIG. 4 according to another modified example.

Embodiments of the present invention will now be described with reference to the accompanying drawings. Note that the following description is essentially merely exemplary and is not intended to limit the present invention, its applications, or its uses. The drawings are schematic, and the proportions of the various dimensions may differ from those of the actual product.

[First embodiment]
1 and 2 show a schematic configuration of a tire testing apparatus 1 according to a first embodiment of the present invention. As shown in Fig. 1 and 2, the tire testing apparatus 1 includes a rolling unit 10 that rolls a tire X to be evaluated under predetermined conditions, and a control unit (not shown) that controls the operation of the rolling unit 10.

As shown in FIG. 1, the rolling unit 10 includes a running platform 11, a wheel 16 on the outer periphery of which the tire X to be evaluated is mounted on a rim, a tire support unit 12 having a hub 13 to which the wheel 16 is attached and rotatably supporting the tire X to be evaluated via the wheel 16 and hub 13, and multiple fastening members 17, 18 that fasten the wheel 16 to the hub 13 at multiple positions around the tire circumference.

The running platform 11 has a strip-shaped endless body 11a wound between a pair of rollers 14, and the tire X to be evaluated rolls on the outer surface of the endless body 11a. The endless body 11a rotates between the pair of rollers 14 by driving at least one of the pair of rollers 14. The tire X to be evaluated is provided with a driving force from the rotating endless body 11a and rotates together with it, rolling on the running platform 11 at the desired moving speed V (relative speed with respect to the endless body 11a).

Referring to Figures 2 and 3, the tire support portion 12 rotatably supports the tire X to be evaluated via the tire rotation axis 12a. More specifically, a hub 13 rotatably attached to one end of the rotation axis 12a is fitted into a hub hole 16a provided in the radial center of the wheel 16, and a hub bolt 17 extending in the direction of the rotation axis 12a and protruding outside the vehicle body is inserted into a bolt insertion hole 16b provided in the wheel 16 and threaded with a nut 18, thereby fastening the hub 13 to the wheel 16.

The hub 13 and wheel 16 use a spigot-fit structure to facilitate their alignment. The spigot-fit structure is designed so that the outer surface of a cylindrical protrusion 13a, which protrudes coaxially from the outside of the hub 13 toward the outside of the vehicle body, abuts against the inner surface of a hub hole 16a formed in the center of the wheel 16.

Figure 4 shows the mounting surface 16c that is attached to the hub of the wheel 16, viewed from the tire axial direction (the direction of arrow IV in Figure 3). As shown in Figure 5, the mounting surface 16c is provided with wheel-side uneven portions 30a that are uneven in the tire axial direction at multiple positions around the tire circumferential direction. The mounting surface 13c of the hub 13, to which the wheel 16 is attached, is provided with hub-side uneven portions 30b that correspond to the wheel-side uneven portions 30a and are uneven in the tire axial direction at multiple positions around the tire circumferential direction.

The wheel-side concave-convex portion 30a and the hub-side concave-convex portion 30b form a complementary abutment concave-convex pair 30 that abuts against each other in the tire axial direction. The abutment concave-convex pair 30 extends in the tire radial direction and is provided around the entire circumference of the mounting surface 13c and the mounted surface 16c.

Referring to Figure 5, the abutting concave-convex pair 30 has a V-shaped cross-sectional groove 31 formed in the mounting surface 16c, and a protrusion 32 formed in the mounting surface 13c of the hub 13 that protrudes complementarily relative to the groove 31. In its cross-sectional shape, the abutting concave-convex pair 30 has a first inclined edge 33 that inclines toward one side in the tire circumferential direction and toward one side in the tire axial direction, and a second inclined edge 34 that inclines toward the other side in the tire circumferential direction and toward the other side in the tire axial direction.

The groove 31 is formed by a groove bottom 31a extending radially from the tire and a pair of inclined surfaces 31b, 31c that slope from the groove bottom 31a toward both sides in the tire circumferential direction, forming an overall V-shaped cross section that continues circumferentially. In this embodiment, the pair of inclined surfaces 31b, 31c are inclined so that both sides in the tire circumferential direction are located closer to the vehicle body inner side (hub 13 side) than the groove bottom 31a side.

The first inclined edge 33 and the second inclined edge 34 form part of the cross section of the pair of inclined surfaces 31b, 31c when viewed radially. Of the pair of inclined surfaces 31b, 31c, the inclined surface on one side formed by the first inclined edge 33 is sometimes referred to as the first inclined surface 31b, and the inclined surface on the other side formed by the second inclined edge 34 is sometimes referred to as the second inclined surface 31c.

The grooves 31 are continuous in the circumferential direction, and between adjacent grooves 31, a protrusion 31d is formed by the first inclined surface 31b on one circumferential side and the second inclined surface 31c on the other circumferential side. In other words, the wheel-side uneven portion 30a is formed by the grooves 31 and the protrusions 31d continuing in the circumferential direction.

The protrusion 32 is formed by a peak 32a extending radially from the tire and a pair of inclined surfaces 32b, 32c that slope from the peak 32a toward both sides in the tire circumferential direction, forming an inverted V-shaped cross section that continues circumferentially. In this embodiment, the pair of inclined surfaces 32b, 32c are inclined so that both sides in the tire circumferential direction are located closer to the vehicle body outer side (wheel 16 side) than the peak 32a.

The first inclined edge 33 and the second inclined edge 34 form part of the cross section of the pair of inclined surfaces 31b, 31c when viewed radially. Of the pair of inclined surfaces 32b, 32c, the inclined surface on one side formed by the first inclined edge 33 is sometimes referred to as the first inclined surface 32b, and the inclined surface on the other side formed by the second inclined edge 34 is sometimes referred to as the second inclined surface 32c.

The protrusions 32 are continuous in the circumferential direction, and between adjacent protrusions 32, a groove 32d is formed by the first inclined surface 32b on one circumferential side and the second inclined surface 32c on the other circumferential side. In other words, the hub-side uneven portion 30b is formed by the protrusions 32 and grooves 32d continuing in the circumferential direction.

The wheel-side uneven portion 30a and the hub-side uneven portion 30b are formed complementarily, so that the groove 31 on the wheel 16 corresponds to the protrusion 32 on the hub 13, and the protrusion 31d on the wheel 16 corresponds to the groove 32d on the hub 13.

As shown in FIG. 5, the inclination angle α1 of the first and second inclined surfaces 31b, 31c, 32b, and 32c relative to a plane perpendicular to the axial direction of the tire is set to be larger than the lead angle β of the bolt 17. More specifically, the inclination angle α1 of the first and second inclined surfaces 31b, 31c, 32b, and 32c is set to be greater than or equal to 5° and less than or equal to 45°.

As shown in FIG. 4, the areas of the first and second inclined surfaces 31b, 31c, 32b, and 32c increase from the inner side toward the outer side in the tire radial direction. The angle γ1 between the first and second inclined surfaces 31b, 31c, 32b, and 32c is set to be greater than or equal to 10° and less than or equal to 20°.

As shown in the enlarged view of Figure 5, when the hub 13 and wheel 16 are misaligned in the rotational direction due to braking or other reasons, the first inclined surfaces 31b, 32b of the hub 13 and wheel 16 move circumferentially. At this time, because the angle α1 of the first inclined surfaces 31b, 32b of the hub 13 and wheel 16 is designed to be larger than the lead angle β of the bolt 17, a relative misalignment occurs between the hub 13 and wheel 16, with the first inclined surface 31b of the wheel 16 climbing up the first inclined surface 32b of the hub 13. However, because the angle α1 of the first inclined surfaces 31b, 32b exceeds the lead angle β, before the bolt 17 loosens, the thickness H11 between the hub 13 and wheel 16 where the bolt 17 is seated increases by the amount that the first inclined surface 31b of the wheel 16 climbs up the first inclined surface 32b of the hub 13. The bolt 17 is stretched by the amount of this increase in thickness H11, and the axial force increases due to the elastic force generated at the same time. This increases the axial force as the hub 13 and wheel 16 attempt to misalign in the rotational direction, preventing misalignment between the hub 13 and wheel 16. This provides a self-locking effect using a Nord-Lock washer.

Furthermore, when the bolt 17 rotates backward due to vibration or other factors, the first inclined surfaces 31b, 32b of the hub 13 and wheel 16 move circumferentially. Because the angle α1 between the first inclined surfaces 31b, 32b of the hub 13 and wheel 16 is designed to be larger than the lead angle β of the bolt 17, a relative misalignment occurs between the hub 13 and wheel 16, with the first inclined surface 31b of the wheel 16 climbing up the first inclined surface 32b of the hub 13. However, because the angle α1 between the first inclined surfaces 31b, 32b of the wheel 16 and hub 13 exceeds the lead angle β, before the bolt 17 loosens, the thickness H11 between the hub 13 and wheel 16 where the bolt 17 rests increases by the amount of the first inclined surface 31b of the wheel 16 climbing up the first inclined surface 32b of the hub 13. The bolt 17 is stretched by the amount of this increase in thickness H11, and the axial force increases due to the elastic force generated at the same time. This increases the axial force as the hub 13 and wheel 16 attempt to misalign in the rotational direction, preventing the hub 13 and wheel 16 from misaligning in the rotational direction due to the return rotation of the bolt 17. This provides a self-locking effect using a Nord-Lock washer.

The width W1 of the protrusion 31d of the wheel 16 at the tire radial position overlapping the bolt 17 is set to be larger than the diameter D of the bolt 17. If the width W1 is smaller than the diameter D of the bolt 17, damage to the bolt 17 due to misalignment between the hub 13 and the wheel 16 in the rotational direction cannot be prevented.

The above configuration increases the contact area between the hub 13 and the wheel 16 compared to when the contact concave-convex pair 30 is not provided. This increases the frictional force between the hub 13 and the wheel 16, making it easier to resist misalignment in the rotational direction of the hub 13 and the wheel 16 under braking and driving conditions in the tire testing device 1, and preventing damage to the bolts 17 that secure them together.

Furthermore, by providing the contact concave-convex pairs 30 that extend radially and are continuous circumferentially, the contact area between the hub 13 and the wheel 16 can be increased compared to when the contact concave-convex pairs 30 are provided only on a portion of the mounting surface 13c and the mounted surface 16c. This further increases the frictional force between the hub 13 and the wheel 16. Because the first and second inclined surfaces 31b, 31c, 32b, 32c are provided on both sides in the circumferential direction, the frictional force between the hub 13 and the wheel 16 can be increased regardless of the direction of tire rotation.

The first and second inclination angles α1 are set to between 5° and 45°, which more reliably achieves the self-locking effect described above. If the first and second inclination angles α1 are less than the 5° (lower limit) lead angle of the bolt 17, the bolt 17 will loosen, making it impossible to increase the axial tension. If the first and second inclination angles α1 are greater than 45°, the hub-side uneven portion 30b and the wheel-side uneven portion 30a will fit together, preventing the frictional effect from being achieved.

In the first embodiment, the abutting concave-convex pair 30 is described as being provided around the entire circumference of the mounting surface 13c of the hub 13 and the mounted surface 16c of the wheel 16, but this is not limited to this. The abutting concave-convex pair 30 may also be provided intermittently between adjacent pairs of bolts 17 among the multiple bolts 17.

In the first embodiment, it was described that the inclination angles α1 of the first inclined edge 33 and the second inclined edge 34 are the same, but this is not limited to this. As in the first modified example shown in Figure 6, in the cross-sectional shape of the abutting concave-convex pair 40, the second inclination angle α2 of the second inclined edge 44, which inclines toward the other side in the tire axial direction toward the other side in the tire circumferential direction, relative to a plane perpendicular to the tire axial direction may be set to be greater than the first inclination angle α1 of the first inclined edge 43, which inclines toward one side in the tire axial direction toward one side in the tire circumferential direction.

As shown in the second modified example in FIG. 7, the contacting concave-convex pairs 50 may be formed in a radial spiral shape so that the radially inner side is located further forward in the tire rotation direction than the outer side, as indicated by arrow R in FIG. 7, when viewed from the tire axial direction. Alternatively, the contacting concave-convex pairs 50 may be formed in a radial spiral shape so that the radially inner side is located further rearward in the tire rotation direction than the outer side, as indicated by arrow R in FIG. 7, when viewed from the tire axial direction. With this configuration, the distance from the radially inner side to the outer side of the contacting concave-convex pairs 50 is increased compared to when the concave-convex portions are arranged linearly, thereby increasing the contact area.

In the first embodiment, multiple abutment concave-convex pairs 30 are formed in the circumferential direction, but this is not limited to this. As in the third modified example shown in Figure 8, the abutment concave-convex pairs 60 (wheel-side concave-convex portion 60a, hub-side concave-convex portion 60b) may be conical with their center at the tire rotational axis. More specifically, the mounting surface 16c of the wheel 16 may be formed with a groove portion 61 that is conically formed so that its depth deepens from the outer side toward the inner side in the tire radial direction, and a protrusion 62 that is conically formed so that its protrusion amount increases from the outer side toward the inner side in the tire radial direction on the mounting surface 13c of the hub 13.

Also, as in the fourth modified example shown in Figure 9, the abutting concave-convex pair 70 (wheel-side concave-convex portion 70a, hub-side concave-convex portion 70b) may be formed by a groove portion 71 formed on the mounting surface 13c of the hub 13 in a conical shape that becomes shallower from the outside toward the inside in the tire radial direction, and a protrusion 72 formed on the mounting surface 16c of the wheel 16 in a conical shape that protrudes more toward the inside from the outside toward the tire radial direction.

The depth H2 of the grooves 61, 71 is set, for example, between 8 mm and 50 mm. If the depth H2 is less than 8 mm, the increase in contact area is small, making it difficult to prevent misalignment of the hub 13 and wheel 16 in the rotational direction. If the depth H2 is greater than 50 mm, the rigidity of the grooved side of the hub 13 or wheel 16 decreases. With this configuration, the mounting surface 13c of the hub 13 and the mounted surface 16c of the wheel 16 are sloped, which increases the contact area between the hub 13 and wheel 16 compared to when the mounting surface 13c of the hub 13 and the mounted surface 16c of the wheel 16 are flat. This further increases the frictional force between the hub 13 and wheel 16.

Second Embodiment
10 shows the configuration of the tire support unit 12 of the tire testing apparatus according to the second embodiment. The tire testing apparatus differs from the tire testing apparatus 1 according to the first embodiment in the mounting surface 13c of the hub 13 and the mounted surface 16c of the wheel 16. Hereinafter, the same reference numerals will be used for the components common to the tire testing apparatus 1, and the description thereof will be omitted.

Figure 10 is a view of the mounting surface 16c that is attached to the hub of the wheel 16, viewed from the tire axial direction (the direction of arrow IV in Figure 3). Referring to Figure 11 in addition to Figure 10, the mounting surface 16c is provided with wheel-side uneven portions 80a that are uneven in the tire axial direction at multiple positions around the tire. The mounting surface 13c of the hub 13, to which the wheel 16 is attached, is provided with hub-side uneven portions 80b that correspond to the wheel-side uneven portions 80a and are uneven in the tire axial direction at multiple positions around the tire.

The wheel-side concave-convex portion 80a and the hub-side concave-convex portion 80b form a complementary mating concave-convex pair 80 that mates with each other in the tire axial direction. The mating concave-convex pairs 80 extend in the tire radial direction and are each provided between adjacent pairs of bolts 17 among the multiple bolts 17.

Referring to Figure 11, the mating concave-convex pair 80 has a V-shaped cross-sectional groove 81 formed on the mounting surface 16c, and a protrusion 82 formed on the mounting surface 13c of the hub 13 that protrudes complementarily relative to the groove 81. In its cross-sectional shape, the mating concave-convex pair 80 has a first inclined edge 83 that inclines toward one side in the tire circumferential direction and toward one side in the tire axial direction, and a second inclined edge 84 that inclines toward the other side in the tire circumferential direction and toward the other side in the tire axial direction.

The groove 81 is formed by a groove bottom 81a extending radially from the tire and a pair of inclined surfaces 81b, 81c that slope from the groove bottom 81a toward both sides in the tire circumferential direction, forming an overall V-shaped cross section that continues circumferentially. In this embodiment, the pair of inclined surfaces 81b, 81c are inclined so that both sides in the tire circumferential direction are located closer to the vehicle body inner side (hub 13 side) than the groove bottom 81a.

The first inclined edge 83 and the second inclined edge 84 form part of the cross section of the pair of inclined surfaces 81b, 81c when viewed radially. Of the pair of inclined surfaces 81b, 81c, the inclined surface on one side formed by the first inclined edge 83 is sometimes referred to as the first inclined surface 81b, and the inclined surface on the other side formed by the second inclined edge 84 is sometimes referred to as the second inclined surface 81c.

The protrusion 82 is formed by a peak 82a extending radially from the tire and a pair of inclined surfaces 82b, 82c that slope from the peak 82a toward both sides in the tire circumferential direction, forming an inverted V-shaped cross section that continues circumferentially. In this embodiment, the pair of inclined surfaces 82b, 82c are inclined so that both sides in the tire circumferential direction are located closer to the vehicle body outer side (wheel 16 side) than the peak 82a.

The first inclined edge 83 and the second inclined edge 84 form part of the cross section of the pair of inclined surfaces 81b, 81c when viewed radially, and of the pair of inclined surfaces 82b, 82c, the inclined surface on one side formed by the first oblique edge 83 is sometimes referred to as the first inclined surface 82b, and the inclined surface on the other side formed by the second oblique edge 84 is sometimes referred to as the second inclined surface 82c.
It is being done.

The wheel-side uneven portion 80a and the hub-side uneven portion 80b are formed complementarily, so that the grooves 81 on the wheel 16 correspond to the protrusions 82 on the hub 13.

As shown in FIG. 11, the inclination angle α3 of the first and second inclined surfaces 81b, 81c, 82b, and 82c relative to a plane perpendicular to the axial direction of the tire is set to be greater than or equal to 30° and less than or equal to 75°.

As shown in FIG. 10, the areas of the first and second inclined surfaces 81b, 81c, 82b, and 82c increase from the inner side toward the outer side in the tire radial direction. The angle γ2 between the first and second inclined surfaces 81b, 81c, 82b, and 82c is set to be greater than or equal to 20° and less than or equal to 45°.

The width W2 of the protrusion 82 (the distance between the lower ends of the pair of inclined surfaces 81b, 81c) at the tire radial position overlapping the bolt 17 is set to be equal to or greater than the diameter D of the bolt 17 and equal to or less than half the distance L between adjacent bolts 17. If the width W2 is equal to or less than the stud bolt diameter D, damage to the bolt 17 due to misalignment between the hub 13 and wheel 16 in the rotational direction cannot be prevented. If the width W2 is greater than half the distance L between the bolts 17, the rigidity of the attached portion 16c of the wheel 16 decreases.

The height H3 of the protrusion 82 at the tire radial position overlapping the bolt 17 is preferably set to 3 mm or more and 40 mm or less. If it is less than 3 mm, it is difficult to resist misalignment of the hub 13 and wheel 16 in the rotational direction due to the engagement of the abutting concave-convex pair 80. If it is greater than 40 mm, assembly is hindered. The height H3 of the protrusion 82 is the distance in the tire axial direction from the apex 81a to the lower ends of the inclined surfaces 82b and 82c.

With the above configuration, by fitting the hub 13 and wheel 16 in the tire axial direction, it is easier to resist rotational misalignment (shear force) between them in the tire rotation direction. More specifically, the shear force caused by rotational misalignment between the hub 13 and wheel 16 in the rotation direction can be applied to the bolt 17 and also borne by the fitting recess-projection pair 80. Therefore, under braking and driving conditions in the tire testing device 200, it is easier to resist misalignment between them in the rotation direction, and damage to the bolt 17 that secures them is prevented.

Furthermore, the simple structure of simply providing complementary mating recess-protrusion pairs 80 on the hub 13 and wheel 16 prevents damage to the bolts 17 that secure the two together. Furthermore, the V-shape allows the wheel 16 to be guided during assembly, making it easy to assemble the wheel 16 to the hub 13.

In the second embodiment, the mating concave-convex pair 80 is described as having a protrusion 82 on the hub 13 side, but this is not limited to this. The wheel 16 side may be formed with a protrusion that protrudes toward the hub 13 side. In this case, the groove portion of the hub 13 should be formed to complementarily fit with the protrusion portion of the wheel 16.

In the second embodiment, the mating concave-convex pair 80 is described as having a V-shaped cross section, but this is not limited to this. As shown by the phantom lines in Figure 11, the mating concave-convex pair 80 may also have a rectangular cross section formed on the mounting surface 16c of the wheel 16.

In the second embodiment, the mating concave-convex pair 80 is described as having one groove 81 and one protrusion 82 between each pair of circumferentially adjacent bolts 17. However, this is not limited to this. As in the fifth modified example shown in FIG. 12, the mating concave-convex pair 90 (wheel-side mating concave-convex pair 90a and hub-side mating concave-convex pair 90b) may have multiple grooves 91 and multiple protrusions 92 between each pair of circumferentially adjacent bolts 17. In this case, the height H4 of the protrusion 92 is set to be equal to or greater than 3 mm and equal to or less than 15 mm, and the width W3 of the protrusion 92 is set to be equal to or greater than 3 mm and equal to or less than 30 mm.

[Third embodiment]
13 shows the configuration of the tire support unit 12 of a tire testing apparatus according to the third embodiment. The tire testing apparatus differs from the tire testing apparatus 1 according to the first embodiment in the mounting surface 13c of the hub 13 and the mounted surface 16c of the wheel 16. Hereinafter, the same reference numerals will be used for the components common to the tire testing apparatus 1, and descriptions thereof will be omitted.

Figure 13 is a view of the mounting surface 16c that is attached to the hub of the wheel 16, viewed from the tire axial direction (the direction of arrow IV in Figure 3). Referring to Figure 14 in addition to Figure 13, the mounting surface 16c is provided with wheel-side uneven portions 100a that are uneven in the tire axial direction at multiple positions around the tire. The mounting surface 13c of the hub 13, to which the wheel 16 is attached, is provided with hub-side uneven portions 100b that correspond to the wheel-side uneven portions 100a and are uneven in the tire axial direction at multiple positions around the tire.

The wheel-side concave-convex portion 100a and the hub-side concave-convex portion 100b form a mating concave-convex pair 100 that are complementary to each other and fit together in the tire axial direction. The mating concave-convex pair 100 has a groove 101 provided on the wheel 16 and extending in the tire axial direction, and a protrusion 102 provided on the hub 13 that fits into the groove 101. The mating concave-convex pair 100 is provided between each pair of circumferentially adjacent bolts 17 among the multiple bolts 17.

It is preferable that at least a portion of the mating concave-convex pair 100 is positioned radially so as to overlap with the bolt 17. In this embodiment, as shown in Figure 13, the mating concave-convex pair 100 is positioned so that the radial direction of the bolt 17 coincides with that of the mating concave-convex pair 100.

As shown in FIG. 13 , the mating recess-projection pair 100 has an elliptical shape when viewed in the tire axial direction. The radial dimension D1 of the protrusion 101 at the tire radial position overlapping the bolt 17 is set to be larger than the bolt diameter D. More specifically, the radial dimension D1 is set to be 16 mm or greater and 42 mm or less. The circumferential dimension D2 of the protrusion 101 is set to be 0.8 times or greater and 1 time or less the radial dimension D1 of the protrusion 101. More specifically, the circumferential dimension D2 is set to be 14 mm or greater and 42 mm or less.

The height H5 of the protrusion 102 at the tire radial position where it overlaps with the bolt 17 is preferably set to be equal to or greater than 3 mm and equal to or less than 40 mm.

With the above configuration, similar to the second embodiment, the hub 13 and wheel 16 are fitted together in the tire axial direction, making it easier to resist rotational misalignment (shear force) between them in the tire rotation direction. More specifically, the shear force caused by rotational misalignment between the hub 13 and wheel 16 in the rotation direction can be applied to the bolt 17 and also borne by the fitting recess-projection pair 90. Therefore, under braking and driving conditions in the tire testing device 300, it is easier to resist misalignment between them in the rotation direction, preventing damage to the bolt 17 that secures them together.

A simple structure that simply provides complementary mating concave-convex pairs 100 on the hub 13 and wheel 16 prevents damage to the bolts 17 that secure them together. Because the mating concave-convex pairs 100 are positioned radially so as to overlap the bolts 17, the mating concave-convex pairs 100 are more likely to withstand the shear force acting on the bolts 17.

In the third embodiment, the mating concave-convex pair 100 is described as having a protrusion 102 on the hub 13 side, but this is not limited to this. The wheel 16 side may be formed with a protrusion that protrudes toward the hub 13 side. In this case, the groove portion of the hub 13 should be formed to complementarily fit with the protrusion portion of the wheel 16.

In the third embodiment, the cross-sectional shape of the mating concave-convex pair 100 is described as being rectangular, but this is not limited to this. The cross-sectional shape of the mating concave-convex pair 100 may be arc-shaped as shown in FIG. 15(a), spherical as shown in FIG. 15(b), triangular in cross section with an apex on the radially outer side as shown in FIG. 15(c), triangular in cross section with an apex on the radially inner side as shown in FIG. 15(d), or trapezoidal as shown in FIG. 15(e).

The third embodiment may also be combined with the first and second embodiments. That is, as shown in FIG. 16, a contact concave-convex pair 30 that increases the contact area may be combined with a mating concave-convex pair 100 that axially mates the hub 13 and wheel 16.

The present invention is not limited to the configuration described in the above embodiment, and various modifications are possible.

REFERENCE SIGNS LIST 1 Tire testing device 11 Running platform 12 Tire support portion 13 Hub 16 Wheel 17 Bolt 18 Nut 30 Contact concave-convex pair 30a Wheel side concave-convex portion 30b Hub side concave-convex portion 40 Contact concave-convex pair 40a Wheel side concave-convex portion 40b Hub side concave-convex portion 50 Contact concave-convex pair 50a Wheel side concave-convex portion 50b Hub side concave-convex portion 60 Contact concave-convex pair 70 Contact concave-convex pair 80 Fitting concave-convex pair 80a Wheel side concave-convex portion 80b Hub side concave-convex portion 90 Fitting concave-convex pair 90a Wheel side concave-convex portion 90b Hub side concave-convex portion 100 Fitting concave-convex pair 100a Wheel side concave-convex portion 100b Hub side concave-convex portion X Tire to be evaluated

Claims (10)

a running platform on which the test tire is brought into contact;
a wheel on which the tire to be evaluated is mounted on a rim;
a tire support unit having a hub to which the wheel is attached and rotatably supporting the tire to be evaluated via the wheel and the hub;
a plurality of fastening members that fasten the wheel to the hub at a plurality of positions in the tire circumferential direction,
the wheel has a wheel-side uneven portion that extends in the tire radial direction and has a predetermined cross-sectional shape that is uneven in the tire axial direction at one or more positions in the tire circumferential direction on a mounting surface that is attached to the hub,
the hub has a hub-side uneven portion that extends in the tire radial direction and has a predetermined cross-sectional shape that is uneven in the tire axial direction at one or more positions in the tire circumferential direction on a mounting surface to which the wheel is mounted,
A tire testing device, wherein the wheel-side concave-convex portion and the hub-side concave-convex portion form a complementary abutting concave-convex pair that abuts against each other in the tire axial direction. The abutting concave-convex pair is
In the cross-sectional shape,
a first inclined side inclined toward one side in the tire circumferential direction;
a second inclined side inclined toward one side in the tire axial direction toward the other side in the tire circumferential direction,
2. The tire testing apparatus according to claim 1. In the cross-sectional shape,
the first inclined side is inclined at a first inclination angle with respect to a plane perpendicular to the tire axial direction,
the second inclined side is inclined at a second inclination angle with respect to a plane perpendicular to the tire axial direction,
the first tilt angle and the second tilt angle are greater than or equal to 5° and less than or equal to 45°;
3. The tire testing apparatus according to claim 2. In the cross-sectional shape,
the first inclined side is inclined at a first inclination angle with respect to a plane perpendicular to the tire axial direction,
the second inclined side is inclined at a second inclination angle with respect to a plane perpendicular to the tire axial direction,
The tire testing apparatus according to claim 2 , wherein the second tilt angle is set to be larger than the first tilt angle. The contact concave-convex pair extends spirally so that the inner side in the tire radial direction is located on one side of the outer side in the tire rotation direction when viewed from the tire axial direction.
The tire testing device according to any one of claims 1 to 4. The abutting concave-convex pair is
It is a cone shape centered on the tire rotation axis,
2. The tire testing apparatus according to claim 1. a running platform on which the test tire is brought into contact;
a wheel on which the tire to be evaluated is mounted on a rim;
a tire support unit having a hub to which the wheel is attached and rotatably supporting the tire to be evaluated via the wheel and the hub;
a plurality of fastening members that fasten the wheel to the hub at a plurality of positions in the tire circumferential direction,
the wheel has a wheel-side uneven portion on a mounting surface attached to the hub, the wheel having a predetermined cross-sectional shape that is uneven in the tire axial direction;
the hub has a hub-side uneven portion on a mounting surface to which the wheel is mounted, the hub having a predetermined cross-sectional shape that is uneven in the tire axial direction,
A tire testing device, wherein the wheel-side concave-convex portion and the hub-side concave-convex portion form a complementary mating concave-convex pair that mate with each other in the tire axial direction. The fitting recess-projection pair is located between the plurality of fastening members in the tire circumferential direction.
8. The tire testing apparatus according to claim 7. The fitting concave-convex pair is
In the cross-sectional shape,
a first inclined side inclined toward one side in the tire circumferential direction;
a second inclined side inclined toward one side in the tire axial direction toward the other side in the tire circumferential direction,
9. The tire testing device according to claim 7 or 8. The fitting concave-convex pair has a rectangular cross-sectional shape.
9. The tire testing device according to claim 7 or 8.