JPH04283104A - Tire wheel structure of vehicle - Google Patents

Abstract

PURPOSE:To reduce road noise without making left, right filler shapes asymmetrical by setting the transmissibility of vibration of the tire part positions relatively remote from a disc part smaller than the tire part positions relatively close to the disc part. CONSTITUTION:In a tire 1, it is formed so that the right and left thickness of a tread part 2 is changed, the part 2a of the tread part 2 comparatively remote from a disc part 12 possesses comparatively large wall thickness T1, the part 2b of the tread part 2 comparatively close to the disc part 12 possesses comparatively small wall thickness t1. In a vehicle mounted with this tire 1, a sound pressure level inside a car room lowers in the frequency not less than 80Hz level, vibration in the vicinity of primary and secondary resonance points of the tire 1 is suppressed, and the road noise accompanies this can be reduced.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a tire and wheel structure for a vehicle, and more particularly to a tire and wheel structure for a vehicle that can reduce road noise without making the left and right filler shapes asymmetrical. be.

0002

2. Description of the Related Art Generally, vehicle tires are connected to an axle or a suspension device via a wheel. The tire includes a tread portion that grips the road surface, left and right sidewall portions that support both ends of the tread portion, and bead portions located at the inner end of each sidewall portion. , a bead wire made of high carbon steel or the like is arranged. Further, the wheel includes a substantially cylindrical rim portion that supports the inner end of the sidewall portion, and a disk portion that supports the rim portion and is connected to an axle or a knuckle portion of a suspension device.

[0003] In such a tire wheel structure,
It is known that a desired lateral rigidity of the tire is secured without increasing the longitudinal rigidity of the tire by configuring the rigidity of the left and right tire bead parts asymmetrically (Utility Model Application No. 58-112602). Publication No.). In this structure,
It is called Bead Avex, and the shape of the filler placed around the left and right bead wires is asymmetrically formed.
This increases the tire's lateral spring constant relative to the tire's longitudinal spring constant.

0004

Problems to be Solved by the Invention Here, the noise level of the noise generated during driving, that is, road noise, is greatly influenced by the vibration characteristics of the tires. In particular, the noise generated around 80 Hz and 100 Hz is
It is understood that this is caused by elastic vibrations caused by the next and second-order resonance points. In order to reduce such road noise, it is possible to form the filler asymmetrically as described above, but changing the vibration transmission characteristics of the tire by such a method only makes it difficult to adjust the lateral stiffness of the tire. Instead, it increases the processing cost of the filler, or
Not only will the strength of the bead portion become non-uniform on the left and right sides, but there is also a risk that the reliability of the strength of the filler will be impaired. This is not preferable in terms of ensuring good steering performance.

[0005] The present invention has been made in view of the above points, and its object is to provide a tire and wheel structure for a vehicle that can reduce road noise without making the left and right filler shapes asymmetrical. It is in.

[0006]

[Means and effects for solving the problem] The present inventor conducted a tire vibration test and measured the vibration of the knuckle caused by the force applied to the tire tread surface.
It has been found that the vibration at the knuckle increases as the point of excitation moves away from the disk portion of the wheel. Based on this knowledge, the present inventor has provided a tread portion that contacts the road surface, left and right sidewall portions that support both ends of the tread portion, and bead portions that are disposed at the inner ends of each of the sidewall portions. In a tire and wheel structure for a vehicle having a tire, a wheel including a substantially cylindrical rim portion supporting each inner end of the bead portion, and a disk portion supporting the rim portion, The vibration transmission rate of the tire portion located far away is set to be smaller than the vibration transmission rate of the tire portion relatively located near the disk portion.

[0007] According to the above structure of the present invention, vibrations transmitted from the tires are compensated for by changing the vibration transmissibility, and road noise is reduced. Moreover, with this configuration, road noise can be reduced while maintaining the symmetrical shapes of the left and right fillers. In an embodiment of the present invention, the thickness of the tread portion located relatively far from the disk portion is set to be thicker than the thickness of the tread portion located relatively close to the disk portion. be done.

In another embodiment of the present invention, the hardness of the tread portion located relatively far from the disk portion is set to be lower than the hardness of the tread portion relatively located near the disk portion. be done. In yet another embodiment of the present invention, the hardness of the sidewall portion located relatively far from the disk portion is set lower than the hardness of the sidewall portion relatively located near the disk portion. be done.

[0009] In another embodiment of the present invention, a vibration damping member is disposed at the bead portion located relatively far from the disk portion. According to such an embodiment, without adding a new material or changing the rubber constituting the tire to another material, such as a special rubber,
Since it is possible to partially change the vibration transmissibility of the tire, it is extremely advantageous in terms of reducing tire manufacturing costs.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic vertical sectional view showing a front wheel of a vehicle to which a tire wheel structure according to an embodiment of the present invention is applied.

In FIG. 1, a tire 1 and a wheel 10
is installed on the vehicle as the front wheel of the vehicle. Tire 1
is supported by the rim part 11 of the wheel 10, and the disc part 12 supporting the rim part 11 is connected to the brake drum 2.
1 and is connected to an axle 23 via a constant velocity joint 22. Further, a knuckle arm 25 of the strut type suspension device rotatably supports an output shaft (not shown) of the constant velocity joint 22. The knuckle arm 25 has its lower end indirectly connected to a lower arm 26 extending from the chassis, and its upper end articulated to a shock absorber 27.

Here, the disk portion 12 extends from the inner circumferential surface of the rim portion 11 to the side of the vehicle, is bent approximately radially inward, and is generally located at a position lower than the center line of the rim portion 11. It is located off to the side of the vehicle. For this reason, tire 1
It has been found that larger vibrations occur in the knuckle arm 25 as the excitation force acting on the wheel acts on the tread surface farther from the disk portion 12 of the wheel, that is, on the inner tread surface in the vehicle width direction.

FIG. 2 is an enlarged longitudinal sectional view showing a first embodiment of the tire and wheel shown in FIG. Note that in FIG. 2, internal structures of the tire such as bead wires are omitted. The tire 1 includes a tread portion 2 that forms a ground contact surface, left and right sidewall portions 3 and 4 that are continuous with the tread portion 2 via shoulder portions, and left and right beads that extend from the sidewall portions 3 and 4 to a rim portion 11. It is generally composed of parts 5 and 6.

A predetermined tread pattern is formed on the tread portion 2 to grip the road surface. Further, the sidewall portions 3 and 4 support both ends of the tread portion 2 via shoulder portions. Furthermore, the bead portions 5 and 6 are connected to the sidewall portions 3 and 4 and the rim portion 11 of the wheel 10.
are firmly connected. Bead wires (not shown) are arranged in the bead parts 5 and 6, and the bead wires are
It works to maintain the air pressure in the tire 1, increase the rigidity of the bead portions, and ensure a strict fit between the bead portions 5, 6 and the rim portion 11.

In the tire 1 of this example, the tread portion 2
The left and right wall thicknesses of the tread portion 2 are different, and the tread portion 2 is located inward in the width direction of the vehicle and relatively distant from the disk portion 12.
The portion 2a of the tread portion 2 has a relatively large wall thickness T1, while the portion 2b of the tread portion 2 located further to the side of the vehicle body and relatively close to the disc portion 12 has a relatively small wall thickness t1.

The present inventor installed a conventional tire having a tread portion of uniform thickness and the tire 1 described above in an actual vehicle, and measured the noise level inside the vehicle. The results are shown in FIG. As shown by the shaded line in FIG. 3, in a vehicle equipped with tire 1, the sound pressure level inside the vehicle is reduced in the frequency range of 80 Hz or higher. It has been found that vibrations near the secondary resonance point, that is, vibrations around frequencies of 80 Hz and 100 Hz, can be suppressed, and the accompanying road noise can be reduced.

FIG. 4 is a partially enlarged longitudinal cross-sectional view showing a second embodiment of a tire and wheel equipped with the tire-wheel structure of the present invention. In FIG. 4, the same reference numerals are attached to the same components as in the first embodiment, and illustration of the bead wire is omitted. In this example, in the tread portion 2, a portion 2a relatively far from the disk portion 12 and a portion 2b relatively close to the disk 12 have different hardnesses. That is, the material forming portion 2a has relatively low hardness, and the material forming portion 2b has relatively high hardness.

A conventional tire with a tread portion having uniform hardness and the tire 1 of this example were each mounted on an actual vehicle, and the noise level inside the vehicle was measured. The test results are shown in Figure 5.
Shown below. As is clear from FIG. 5, the tire 1 of this embodiment, in which the tread portion 2 is composed of portions with different hardness, has a hardness of 80H.
The tire 1 has the effect of reducing the sound pressure level in the frequency range of z or higher, and the tire 1 has the effect of reducing the sound pressure level in the
It has been found that vibration near the next resonance point can be suppressed and the associated road noise can be effectively reduced.

FIG. 6 is a partially enlarged vertical cross-sectional view showing a third embodiment of a tire and wheel equipped with the tire-wheel structure of the present invention. In FIG. 6, the same reference numerals are attached to the same components as in the first and second embodiments, and illustration of the bead wire is omitted. In the tire 1 of this example, the left and right sidewall portions 3 and 4 have different hardnesses. The sidewall portion 4 relatively close to the disk portion 12 is made of a material with relatively high hardness, and the sidewall portion 3 relatively distant from the disk portion 12 is made of a material with relatively high hardness.
is made of a material with relatively low hardness.

A conventional tire whose left and right sidewall portions have the same hardness and the tire 1 of this example were mounted on an actual vehicle, and the noise level inside the vehicle was measured. The test results are shown in FIG. As is clear from FIG. 7, the tire 1 of this example also has the effect of reducing the sound pressure level in the frequency range of 80 Hz or higher, as shown in FIG. It has been found that vibrations near the primary and secondary resonance points can be suppressed, and the associated road noise can be effectively reduced.

FIG. 8 is a partially enlarged longitudinal cross-sectional view showing a fourth embodiment of a tire and wheel equipped with the tire and wheel structure of the present invention, and FIG. 9 is an enlarged view of the area around the wire bead disposed in the bead portion. It is. FIG. 8 shows fillers 8L and 8R disposed in the bead portions 5 and 6. The fillers 8L and 8R are mainly used to increase the lateral rigidity of the tire, and are arranged adjacent to the wire beads 7L and 7R. The tire 1 includes the wire bead 7 that is relatively far away from the disk portion 12 among the wire beads 7L and 7R.
A vibration damping member 9 made of a sheet-like rubber having a thickness of about 1 mm is attached to L, for example. As shown in FIG. 9, the vibration damping member 9 is located on the opposite side of the filler 8L, that is,
Located below the wire bead 7L, the wire bead 7L
covers the lower half of the

A conventional tire without the vibration damping member 9 and the tire 1 of this embodiment were each mounted on an actual vehicle, and the noise level inside the vehicle was measured. The test results are shown in FIG. In the tire 1 of this embodiment, as a result of the vibration damping member 9 being inserted between the rubber and cord constituting the bead portions 5 and 6 and the wire bead 7L, the sound pressure level is particularly low in the frequency range of 200 Hz or higher. It was found that it has the effect of reducing Here, since the secondary resonance point in the deformation mode of the cut shape of the tire 1 longitudinally cut, that is, the cross-sectional deformation mode of the tire 1, is around a frequency of 300 to 350 Hz, the structure of the tire 1 is This is advantageous in suppressing nearby vibrations and reducing accompanying road noise.

As described above, in each of the above-mentioned embodiments, the tire wheel structure includes the tread portion 2 that is in contact with the road surface, the left and right sidewall portions 3 and 4 that support both ends of the tread portion, and the sidewall portions. A tire 1 includes bead portions 5 and 6 disposed at the inner ends of the sidewall portions 3 and 4, a substantially cylindrical rim portion 11 supporting the inner ends of the sidewall portions 3 and 4, and a rim portion 11. The wheel 10 includes a supporting disk portion 12. The portion 2b of the tread portion 2 located relatively close to the disk portion 12 has a relatively thin wall thickness t1 or has relatively high hardness, while the portion 2b located relatively far from the disk portion 12 has a relatively thin wall thickness t1 or has a relatively high hardness. The portion 2a of the tread portion 2 has a relatively thick wall thickness T1.
or is configured to have relatively low hardness. Alternatively, the sidewall portion 4 located relatively close to the disk portion 12 has a relatively high hardness, while the sidewall portion 3 located relatively far from the disk portion 12 has a relatively low hardness. Constructed to have hardness. As still another means, the rubber and cord forming the bead portion 5 on the side relatively distant from the disk 12;
A vibration damping member 9 is inserted between the wire bead 7L disposed on the bead portion 5.

The vibration transmissibility of the tire 1 constructed in this manner, that is, the ratio of the vibration output at the knuckle arm 25 to the vibration input from the ground contact surface of the tire 1 is large in a portion relatively close to the disk portion 12; On the contrary, the disk part 12
It is small in the part relatively far from. As a result, the tire 1 has a knuckle arm 25 due to the change in vibration transmission rate.
Compensates for vibrations in the frequency range of 80 Hz or higher or 200 Hz or higher that occur in the vehicle, lowers the noise level in the vehicle interior, and reduces road noise, as shown in the test results mentioned above. Moreover, with this configuration, substantially uniform strength of the left and right bead portions 5 and 6 is ensured without changing the shapes of the left and right fillers 8L and 8R.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various changes and modifications are possible, and these are also included in the claims. It goes without saying that these inventions are included in the present invention within the scope of the invention. For example, the third
In the embodiment, instead of changing the hardness of the sidewall portion, or in addition thereto, the thickness of the sidewall portion 3 may be set small and the thickness of the sidewall portion 4 may be set large.

Furthermore, in the fourth embodiment described above, vibrations in the frequency range of 200 Hz or higher are reduced by attaching the vibration damping member 9 made of sheet-like rubber to the wire bead 7L, but the material of the rubber may be changed. By doing so, it is also possible to change the frequency range in which vibration should be suppressed. Furthermore,
The sheet-like rubber may be inserted between the bead portion 5 and the rim portion 11.

[0027]

According to the above configuration of the present invention, it is possible to provide a tire wheel structure for a vehicle that can reduce road noise without making the left and right filler shapes asymmetrical.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view showing a front wheel of a vehicle to which a tire wheel structure according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged longitudinal sectional view showing a first embodiment of the tire and wheel shown in FIG. 1;

FIG. 3 is a diagram showing test results of actual vehicle tests of a conventional tire and the tire shown in FIG. 2;

FIG. 4 is a partially enlarged longitudinal cross-sectional view showing a second embodiment of a tire and wheel equipped with the tire-wheel structure of the present invention.

FIG. 5 is a diagram showing test results of actual vehicle tests of a conventional tire and the tire shown in FIG. 4;

FIG. 6 is a partially enlarged vertical cross-sectional view showing a third embodiment of a tire and wheel equipped with the tire-wheel structure of the present invention.

7 is a diagram showing test results of actual vehicle tests of a conventional tire and the tire shown in FIG. 6. FIG.

FIG. 8 is a partially enlarged vertical cross-sectional view showing a fourth embodiment of a tire and wheel equipped with the tire-wheel structure of the present invention.

FIG. 9 is an enlarged view of the area around the wire bead disposed in the bead portion.

10 is a diagram showing test results of actual vehicle tests of a conventional tire and the tire shown in FIG. 8; FIG.

[Explanation of symbols]

1 Tires 2 Tread part 3 Sidewall part 4 Sidewall part 5 Bead part 6 Bead part 7L Bead wire 7R Bead wire 8L filler 8R filler 9 Vibration damping member 10 Wheel 11 Rim part 12 Disc part

Claims (5)

[Claims] 1. A tire comprising a tread portion that contacts a road surface, left and right sidewall portions that support both ends of the tread portion, and bead portions disposed at inner ends of each of the sidewall portions; In a tire wheel structure for a vehicle, the wheel includes a generally cylindrical rim portion supporting each inner end of the rim portion, and a wheel including a disk portion supporting the rim portion, the wheel being located relatively far from the disk portion. A tire wheel structure for a vehicle, characterized in that a vibration transmission rate of a tire portion is set to be smaller than a vibration transmission rate of the tire portion located relatively near the disk portion. 2. The tread portion located relatively far from the disk portion is thicker than the tread portion relatively located near the disk portion. The tire wheel structure for a vehicle according to claim 1. 3. The hardness of the tread portion located relatively far from the disk portion is set to be lower than the hardness of the tread portion relatively located near the disk portion. Item 1. Tire and wheel structure for the vehicle according to item 1. 4. The hardness of the sidewall portion located relatively far from the disk portion is set lower than the hardness of the sidewall portion relatively located near the disk portion. The tire wheel structure for a vehicle according to claim 1. 5. The tire wheel structure for a vehicle according to claim 1, wherein a vibration damping member is provided in the bead portion located relatively far from the disk portion.