JP7394635B2 - pneumatic tires - Google Patents

Description

The present invention relates to pneumatic tires.

Conventionally, a pneumatic tire including a carcass and a reinforcing layer disposed between a rolled up part of the carcass and a bead filler is known (for example, see Patent Document 1).

However, in the conventional pneumatic tires, noise generation due to vibration of the sidewall portion during running is not sufficiently considered.

Japanese Patent Application Publication No. 2018-177067

SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatic tire that can suppress the generation of noise due to vibration of the tire side portion during running.

A first aspect of the present invention provides, as a means for solving the above problem, a bead core arranged on both sides in the tire width direction, and a pair of bead fillers arranged outward from the bead core in the tire radial direction. , a carcass main body that spans over the bead core, a carcass having a carcass winding portion that extends from the outside in the tire width direction of the bead core to the outside in the tire radial direction beyond the bead filler, and the carcass main body and the carcass winding. a rubber layer disposed between the upper parts, and the rubber layer extends from the outer end of the bead filler in the tire radial direction to the outer end of the tire radial direction in a region where the carcass main body part and the carcass winding part overlap. occupies at least 50% of the length in the meridian direction of the area between the parts , and the outer end of the carcass winding part in the tire radial direction is located on the outer side in the tire radial direction than the tire maximum width position,
The outer end of the rubber layer in the tire radial direction has a length of 10 mm in the meridian direction from the outer end of the carcass winding part in the tire radial direction toward the outside in the tire radial direction, and a length of 30 mm in the meridian direction toward the tire radial inside. We provide pneumatic tires located in the range of

With this configuration, a gap in which the rubber layer is interposed can be formed between the carcass main body and the carcass winding upper part. This makes it difficult for vibrations to occur in this area during driving, making it possible to suppress the generation of noise.

With this configuration, generation of vibration can be sufficiently suppressed. Conversely, even if the rubber layer is formed to exceed the above range, it will not contribute much to suppressing the occurrence of vibrations. In other words, an increase in weight due to unnecessary formation of a rubber layer can be prevented.

A second aspect of the present invention includes a bead core arranged on both sides in the tire width direction, a pair of bead fillers arranged outward from the bead core in the tire radial direction, and a carcass main body part stretched over the bead core. , and a carcass having a carcass winding part extending from the outside in the tire width direction of the bead core to the outside in the tire radial direction beyond the bead filler, and a rubber layer disposed between the carcass body part and the carcass winding part. The rubber layer is arranged in a meridian direction of a region between an outer end in the tire radial direction of the bead filler and an outer end in the tire radial direction of a region where the carcass main body portion and the carcass winding portion overlap. occupies at least 50% of the length of the carcass, an outer end in the tire radial direction of the winding portion of the carcass is located on the outer side in the tire radial direction than the tire maximum width position, and an inner end in the tire radial direction of the rubber layer To provide a pneumatic tire in which the length of a bead filler in the meridian direction toward the outside in the tire radial direction is 30 mm and the length in the meridian direction toward the inside in the tire radial direction is located within a range of 10 mm from the tire radial direction outer end .

With this configuration, generation of vibration can be sufficiently suppressed. Conversely, even if the rubber layer is formed to exceed the above range, it will not contribute much to suppressing the occurrence of vibrations. In other words, an increase in weight due to unnecessary formation of a rubber layer can be prevented.

A third aspect of the present invention includes a bead core arranged on both sides in the tire width direction, a pair of bead fillers arranged outward from the bead core in the tire radial direction, and a carcass main body part stretched over the bead core. , and a carcass having a carcass winding part extending from the outside in the tire width direction of the bead core to the outside in the tire radial direction beyond the bead filler, and a rubber layer disposed between the carcass body part and the carcass winding part. The rubber layer is arranged in a meridian direction of a region between an outer end in the tire radial direction of the bead filler and an outer end in the tire radial direction of a region where the carcass main body portion and the carcass winding portion overlap. occupies at least 50% of the length, the outer end in the tire radial direction of the winding part of the carcass is located on the inner side in the tire radial direction than the tire maximum width position, and the outer end in the tire radial direction of the rubber layer To provide a pneumatic tire in which lengths in the meridian direction toward the outside and inside in the tire radial direction from the outside end in the tire radial direction of a carcass winding part are located within a range of 10 mm, respectively.

With this configuration, generation of vibration can be sufficiently suppressed. Conversely, even if the rubber layer is formed to exceed the above range, it will not contribute much to suppressing the occurrence of vibrations. In other words, an increase in weight due to unnecessary formation of a rubber layer can be prevented.

The tire radial outer end of the carcass winding upper part is located on the tire radial inner side than the tire maximum width position, and the tire radial inner end of the rubber layer is located within the tire radial direction from the tire radial outer end of the bead filler. It is preferable that the lengths in the inner direction and the meridian direction toward the inner side are each within a range of 10 mm.

With this configuration, generation of vibration can be sufficiently suppressed. Conversely, even if the rubber layer is formed to exceed the above range, it will not contribute much to suppressing the occurrence of vibrations. In other words, an increase in weight due to unnecessary formation of a rubber layer can be prevented.

The rubber layer preferably has a thickness of 0.5 mm or more and 3.0 mm or less.

With this configuration, it is possible to effectively prevent vibration from occurring while suppressing the weight of the rubber layer.

It is preferable that the thickness of the rubber layer differs depending on the position in the tire radial direction.

With this configuration, the rubber layer can be thickened at locations where vibrations are likely to occur, thereby effectively preventing vibrations while suppressing an increase in weight.

The hardness of the rubber layer is preferably lower than that of the bead filler.

According to the present invention, it is possible to suppress the generation of noise due to vibration of the tire side portion during running.

FIG. 1 is a meridian cross-sectional view of a pneumatic tire according to a first embodiment. 2 is a partially enlarged view of FIG. 1. FIG. FIG. 2 is a partially enlarged view showing the relationship between the rubber layer and the carcass winding portion shown in FIG. 1; FIG. 2 is a partially enlarged view showing the relationship between the rubber layer and the carcass winding portion shown in FIG. 1; FIG. 2 is a partially enlarged view showing the relationship between the rubber layer and the carcass winding portion shown in FIG. 1; FIG. 3 is a meridian cross-sectional view of a pneumatic tire according to a second embodiment. 7 is a partially enlarged view of FIG. 6. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the following description is essentially just an example, and is not intended to limit the present invention, its applications, or its uses.

(First embodiment)
FIG. 1 is a meridian cross-sectional view of a pneumatic tire (hereinafter simply referred to as a tire) according to a first embodiment, and FIG. 2 is a partially enlarged view thereof. The tire includes a tread portion 1, a pair of sidewall portions 2, and a pair of ring-shaped bead portions 3.

The tread portion 1 extends in the tire width direction (indicated by the symbol TW in FIG. 1). A groove 1a is provided on the surface of the tread portion 1, that is, the tread surface.

The pair of sidewall portions 2 extend inward from both ends of the tread portion 1 in the tire radial direction (indicated by symbol TR in FIG. 1).

The pair of bead portions 3 are respectively arranged at the inner end portions of the pair of sidewall portions 2 in the tire radial direction. Each bead portion 3 includes a bead core 4 and a bead filler 5. The bead core 4 includes a large number of steel wires bundled into a ring shape. The bead filler 5 has a ring shape and is made of rubber having a harder hardness than the rubber forming the tread portion 1 and the sidewall portion 2. The bead filler 5 includes a base end 5a disposed adjacent to the outside of the bead core 4 in the tire radial direction, and a tip 5b opposite to the base end 5a, and extends in the tire radial direction from the base end 5a toward the tip 5b. It extends outward in a tapered shape.

A carcass 6 is wrapped around a pair of bead cores 4. A chafer 7 is wound around the carcass 6 which is stretched around the bead core 4. An inner liner 8 is provided inside the carcass 6, that is, on the innermost circumferential surface of the tire. An endless belt layer 9 and a reinforcing layer 10 are provided between the carcass 6 and the tread portion 1. The belt layer 9 includes two belts 11A and 11B. The reinforcing layer 10 includes one reinforcing belt 12. The belts 11A, 11B and the reinforcing belt 12 are formed by coating belt cords made of steel or organic fiber with rubber. The dimension of the lower layer belt 11A in the tire width direction is larger than the dimension of the upper layer belt 11B in the tire width direction, and the end 11a of the belt 11A is located on the outer side in the tire width direction than the end 11b of the belt 11B. There is.

Although not shown in detail, the carcass 6 is made up of a single carcass ply in which a plurality of carcass cords arranged in parallel at predetermined intervals are coated with rubber. The carcass cord is made of organic fibers such as nylon fibers. The carcass 6 includes a carcass main body portion 13 disposed on the inside in the tire radial direction, and a carcass winding portion 14 that is folded back and rolled up by the bead core 4. In this embodiment, the tire radial outer end (hereinafter simply referred to as the carcass outer end) 14a of the carcass winding portion 14 is located on the tire radial outer side than the tire maximum width position WM (so-called high turn up structure). Here, the carcass outer end 14a is located near the end 11a of the lower belt 11A.

A rubber layer 15 is arranged in the region between the carcass main body 13 and the carcass winding upper part 14. Specifically, the rubber layer 15 extends from the tip 5b of the bead filler 5 to the outer end in the tire radial direction TR of the area where the carcass main body 13 and the carcass winding upper part 14 overlap, that is, to the carcass outer end 14a. It is arranged so as to occupy at least 50% of the length L in the meridian direction of the region. This length L is the periphery length of the region, which will be described later . However, in FIG. 2, the length L is shown as a straight line distance in the tire radial direction (this point is also the same in FIG. 4 regarding a second embodiment described later). If the rubber layer 15 occupies less than 50% of the area, there is a possibility that the vibrations generated in the sidewall portion 2 during driving may not be sufficiently suppressed. In the first embodiment, the rubber layer 15 is arranged so as to occupy all of the area, that is, 100% (this point also applies to the second embodiment described later). The rubber layer 15 is made of rubber whose hardness is smaller than that of the bead filler 5. The rubber layer 15 may be formed of a single rubber sheet, or may have a structure in which a plurality of rubber sheets are stacked one on top of the other.

In the first embodiment, both ends of the rubber layer 15 are an outer end in the tire radial direction (hereinafter simply referred to as the outer end of the rubber layer) 15a and an inner end in the tire radial direction (hereinafter simply referred to as the inner end of the rubber layer). .) It is formed so that it becomes gradually thinner toward 15b.

In the first embodiment, the rubber layer outer end 15a is arranged within a first setting range A with respect to the carcass outer end 14a. The first setting range A is such that the length of the carcass cord extending from the carcass outer end 14a toward the meridian direction on the outside in the tire radial direction (hereinafter simply referred to as periphery length) is a1 (within 10 mm, preferably 5 mm). (within 30 mm, preferably within 5 mm) and the periphery length toward the inner side in the tire radial direction is within a2 range (within 30 mm, preferably within 5 mm). However, in FIG. 2, the lengths a1 and a2 are shown as straight distances in the tire radial direction. The reason why the periphery length from the carcass outer end 14a toward the tire radial direction outside is set to within 10 mm is to suppress unnecessary mass increase due to the rubber layer 15 protruding largely from the carcass outer end 14a. Furthermore, by ensuring an appropriate distance between the outer end 14a of the carcass and the outer end 15a of the rubber layer, it is also possible to prevent failures due to concentration of strain and process defects such as air intrusion during tire manufacturing. Furthermore, the reason why the periphery length from the carcass outer end 14a toward the tire radial inner side is set to within 30 mm is that by securing an appropriate distance between the carcass outer end 14a and the rubber layer outer end 15a, strain concentration can be prevented. This is to prevent malfunctions and process defects such as air intrusion during tire manufacturing.

One end portion of the rubber layer 15 (a portion that gradually becomes thinner toward the outer end 15a of the rubber layer) can be configured as follows with respect to the outer end 14a of the carcass.

In FIG. 3, the thickness of one end of the rubber layer 15 gradually becomes thinner at a portion extending outward in the tire radial direction beyond the carcass outer end 14a. According to this configuration, there is an advantage that the carcass main body portion 13 and the carcass winding portion 14 can be reliably arranged apart from each other, and that the effect of suppressing vibrations can be enhanced.

In FIG. 4, the thickness of one end of the rubber layer 15 gradually becomes thinner so that the outer end 15a of the rubber layer matches the outer end 14a of the carcass. Therefore, the outer portion of the carcass winding portion 14 in the tire radial direction gradually approaches the carcass main body portion 13. According to this configuration, there is an advantage that the weight of the rubber layer 15 can be suppressed and a vibration suppressing effect can be obtained.

In FIG. 5, at one end of the rubber layer 15, the rubber layer outer end 15a is located on the inner side in the tire radial direction than the carcass outer end 14a. Therefore, the outer portion of the carcass winding portion 14 in the tire radial direction comes into contact with the carcass main body portion 13. This configuration has the advantage that the weight of the rubber layer 15 can be further reduced compared to the configuration shown in FIG.

In the first embodiment, the rubber layer inner end 15b is arranged within the second setting range B with respect to the tip 5b of the bead filler 5. In the second setting range B, the periphery length from the tip 5b of the bead filler 5 toward the outside in the tire radial direction is b1 (within 30 mm, preferably within 10 mm), and the periphery length toward the inside in the tire radial direction is b2 (10 mm). (preferably within 5 mm). However, in FIG. 2, the lengths b1 and b2 are shown as straight distances in the tire radial direction. The distance from the tip 5b of the bead filler 5 to the outside in the tire radial direction is within 30 mm by ensuring an appropriate distance between the tip 5b of the bead filler 5 and the inner end 15b of the rubber layer. This is to prevent excessive increase in rigidity and deterioration of ride comfort performance. In addition, the reason why the distance is within 10 mm from the tip 5b of the bead filler 5 toward the inner side in the tire radial direction is to ensure an appropriate distance between the tip 5b of the bead filler 5 and the inner edge 15b of the rubber layer to prevent concentration of strain. This is to prevent malfunctions caused by this and process defects such as air intrusion during tire manufacturing.

In the first embodiment, the thickness of the rubber layer 15 is set to 0.5 mm or more and 3.0 mm or less. Moreover, the average value of the thickness dimension of the rubber layer 15 is set to 0.5 mm or more and 1.5 mm or less. The reason why the minimum value of the thickness dimension of the rubber layer 15 is set to 0.5 mm is because it is the minimum value that can be processed at present. The reason why the maximum thickness of the rubber layer 15 is set to 3.0 mm is because if it becomes thicker than this, the negative side of increased weight becomes greater than the vibration suppressing effect.

The tire according to the first embodiment has the following characteristics.

A rubber layer 15 is provided between the carcass main body part 13 and the carcass winding upper part 14, and the two are configured so that they do not come into contact with each other or hardly come into contact with each other. Therefore, even when the tire having the above configuration is run on a road surface, the vibration of the sidewall portion 2 is suppressed by the rubber layer 15, and noise is hardly generated.

A carcass winding upper part 14 is arranged over almost the entire sidewall part 2. In other words, two layers of carcass 6 are provided in the sidewall portion 2. Therefore, the cut resistance and rigidity necessary for the sidewall portion 2 are ensured.

The rubber layer 15 is formed to become gradually thinner toward the outside in the tire radial direction from a position beyond the carcass outer end 14a. Further, the rubber layer 15 is formed to become gradually thinner from the tip 5b of the bead filler 5 toward the inner side in the tire radial direction. In other words, the thickness of the rubber layer 15 gradually becomes thinner at both end portions in the tire radial direction, and there is no extreme change in shape. Therefore, problems such as peeling due to stress concentration during running are less likely to occur.

The outer end 15a of the rubber layer is located within the first setting range A. That is, the rubber layer 15 is arranged so that the periphery length does not increase beyond the upper limit of the first setting range A to the outside in the tire radial direction. Therefore, the weight of the rubber layer 15 on the rubber layer outer end 15a side does not increase more than necessary. Further, the rubber layer 15 is arranged so that the periphery length does not become smaller than the lower limit of the first setting range A. Therefore, on the carcass outer end 15a side, the minimum necessary distance can be secured between the carcass main body part 13 and the carcass winding upper part 14 by the rubber layer 15. In other words, it is possible to suppress the occurrence of vibration in the sidewall portion 2 while suppressing the weight of the rubber layer 15 on the carcass outer end 15a side.

The rubber layer inner end 15b is arranged within the second setting range B. That is, the rubber layer 15 is arranged so that the periphery length does not increase beyond the upper limit of the second setting range B to the inner side in the tire radial direction. Therefore, the weight of the rubber layer 15 on the rubber layer inner end 15b side does not increase more than necessary. Further, the inner end 15b of the rubber layer is arranged so that the periphery length does not become smaller than the lower limit of the second setting range B. Therefore, the minimum necessary distance can be secured by the rubber layer 15 between the carcass main body part 13 and the carcass winding upper part 14 on the rubber layer inner side end 15b side. In other words, it is possible to suppress the occurrence of vibration in the sidewall portion 2 while suppressing the weight of the rubber layer 15 on the outside in the tire radial direction. In particular, in the case of a high turn-up structure, the carcass winding upper part 14 has a long peripheral length from a position corresponding to the tip 5b of the bead filler 5 to the carcass outer end 14a. Therefore, vibration can be sufficiently suppressed without necessarily arranging the rubber layer 15 in all the regions. Therefore, by setting the peripheral lengths a2 and b1 of the rubber layer 15 to be relatively long, vibrations can be suppressed more efficiently.

(Second embodiment)
FIG. 6 is a meridian cross-sectional view of a tire according to a second embodiment, and FIG. 7 is a partially enlarged view thereof. The basic structure of this tire is the same as that of the tire according to the first embodiment, and the same parts are given corresponding symbols and the explanation thereof will be omitted, and only the different structures will be explained below.

The carcass outer end 14a is located inward in the tire radial direction from the tire maximum width position WM (so-called low turn-up structure). Here, the carcass outer end 14a is located near the tire maximum width position WM.

The rubber layer outer end 15a is arranged within a third setting range C with respect to the carcass outer end 14a. In the third setting range C, the periphery length from the carcass outer end 14a toward the outside in the tire radial direction is c1 (within 10 mm, preferably within 5 mm), and the periphery length toward the inside in the tire radial direction is c2 (within 10 mm, It may be within a range of (preferably within 5 mm). However, in FIG. 7, the lengths c1 and c2 are shown as straight-line distances in the tire radial direction, but they are actually distances along the tire circumferential direction. The reason why the periphery length from the carcass outer end 14a toward the tire radial direction outside is set to within 10 mm is to suppress unnecessary mass increase due to the rubber layer 15 protruding largely from the carcass outer end 14a. Furthermore, by ensuring an appropriate distance between the outer end 14a of the carcass and the outer end 15a of the rubber layer, it is also possible to prevent failures due to concentration of strain and process defects such as air intrusion during tire manufacturing. Furthermore, the reason why the periphery length from the carcass outer end 14a toward the inner side in the tire radial direction is set to within 10 mm is that by ensuring an appropriate distance between the carcass outer end 14a and the rubber layer outer end 15b, strain concentration can be prevented. This is to prevent malfunctions and process defects such as air intrusion during tire manufacturing. In FIG. 7, the rubber layer outer end 15a is located slightly outside the maximum width position WM in the tire radial direction.

The inner end 15b of the rubber layer is arranged within the fourth setting range D with respect to the tip 5b of the bead filler 5. The fourth setting range D is such that the periphery length from the tip 5b of the bead filler 5 toward the outside in the tire radial direction is d1 (within 10 mm, preferably within 5 mm), and the periphery length toward the inside in the tire radial direction is d2 (10 mm). (preferably within 5 mm). However, although the lengths d1 and d2 are shown as straight-line distances in the tire radial direction in FIG. 7, they are actually distances along the tire circumferential direction. The periphery length from the tip 5b of the bead filler 5 toward the outside in the tire radial direction is set to within 10 mm by ensuring an appropriate distance between the tip 5b of the bead filler 5 and the inner end 15b of the rubber layer. This is to prevent an excessive increase in the longitudinal rigidity of the tire and to prevent deterioration of ride comfort performance. In addition, the reason why the periphery length from the tip 5b of the bead filler 5 toward the inner side in the tire radial direction is set to within 10 mm is to ensure an appropriate distance between the tip 5b of the bead filler 5 and the inner end 15b of the rubber layer. This is to prevent failures due to concentration of strain and process defects such as air intrusion during tire manufacturing. In FIG. 7, the inner end 15b of the rubber layer is arranged in a range of a peripheral length d2 from the tip 5b of the bead filler 5 on the inner side in the tire radial direction.

The tire according to the second embodiment has the following characteristics.

Since the rubber layer 15 is provided between the carcass main body part 13 and the carcass winding upper part 14, the vibration of the sidewall part 2 is suppressed and noise is less likely to occur, similarly to the first embodiment.

Since the rubber layer 15 is not formed on the outside in the tire radial direction from the tire maximum width dimension position of the sidewall portion 2, the weight of the rubber layer 15 can be suppressed and the weight of the tire can be reduced, contributing to improved fuel efficiency. .

The rubber layer outer end 15a is arranged within the third setting range C. In other words, the rubber layer 15 is arranged so that the periphery length on the outside in the tire radial direction does not increase beyond the upper limit of the third setting range C. Therefore, the weight of the rubber layer 15 on the rubber layer outer end 15a side does not increase more than necessary. Further, the rubber layer 15 is arranged so that the periphery length does not become smaller than the lower limit of the third setting range C. Therefore, the rubber layer 15 can ensure the minimum necessary distance between the carcass main body 13 and the carcass winding upper part 14 on the rubber layer outer end 15a side. In other words, it is possible to suppress the occurrence of vibration in the sidewall portion 2 while suppressing the weight of the rubber layer 15 on the outside in the tire radial direction.

The inner end 15b of the rubber layer is arranged within the fourth setting range D. That is, the rubber layer 15 is arranged so that the periphery length inward in the tire radial direction does not increase beyond the upper limit of the fourth setting range D. Therefore, the weight of the rubber layer 15 does not increase more than necessary on the rubber layer inner end 15b side. Furthermore, the rubber layer 15 is arranged so that the periphery length does not become smaller than the lower limit of the fourth setting range D. Therefore, the rubber layer 15 can ensure the minimum necessary distance between the carcass body part 13 and the carcass winding upper part 14 on the inner side in the tire radial direction. In other words, it is possible to suppress the occurrence of vibration in the sidewall portion 2 while suppressing the weight of the rubber layer 15 on the outside in the tire radial direction. In particular, in the case of the low turn-up structure, the carcass winding upper part 14 has a short peripheral length from the position corresponding to the tip 5b of the bead filler 5 to the carcass outer end 14a. Therefore, it is preferable to arrange the rubber layer 15 in all the regions in order to suppress vibrations. Therefore, by setting the periphery length of the rubber layer 15 to a relatively small value, vibrations can be suppressed more efficiently.

Note that the present invention is not limited to the configuration described in the above embodiments, and various changes are possible.

In the embodiment described above, the thickness of the rubber layer 15 was made to gradually become thinner at both ends, but it may be formed into a flat plate shape that is uniform throughout, or the thickness may change at an intermediate portion other than both ends. It may also be formed non-uniformly. If the thickness of the rubber layer 15 is to be made non-uniform, machining may be performed, but the following configuration may also be used. That is, the rubber layer 15 may be formed by stacking a plurality of rubber sheets, and the number of stacked rubber sheets may be increased in areas where the thickness is desired, and the number may be reduced in areas where the thickness is desired. According to this, it is only necessary to prepare rubber sheets of the same thickness, and by adjusting the number of overlapping sheets, the desired thickness can be easily obtained.

In particular, when the thickness of the rubber layer 15 is made non-uniform, it is preferable to change the thickness based on the difference in the magnitude of vibrations generated at each part of the sidewall portion 2 during running. For example, while a tire is set in a testing machine and rotated on a test stand under a load, a laser is irradiated to the sidewall portion 2 from the side, and the vibration frequency at the irradiation position is determined based on the reflected light. Measure. Then, based on the obtained results, the thickness of the rubber layer 15 may be increased in the region of the sidewall portion 2 where the vibration in the tire radial direction is large.

Although the sidewall rubber constituting the sidewall portion 2 is not particularly mentioned in the embodiment, the sidewall rubber is not particularly thick in the region of the sidewall portion 2 where the rubber layer 15 is provided. It is preferable to adjust the thickness of the rubber. According to this, desired rigidity can be obtained while suppressing the occurrence of vibration in the sidewall portion 2 and keeping the weight of the sidewall portion 2 within an appropriate range.

In the embodiment described above, the rubber layer 15 is composed of one member connected in the tire radial direction, but it may be composed of two or more members separated in the tire radial direction. In this case, the region where the rubber layer 15 is provided and the region where it is not provided may be determined based on the difference in vibration at each portion of the sidewall portion 2, as described above. That is, the rubber layer 15 may be provided in a region where the vibration frequency is higher than a preset threshold value. In this case, the threshold value may be set in multiple stages, and the thickness of the rubber layer 15 may be changed according to each stage.

In the embodiment, the rubber layer 15 is arranged symmetrically with respect to the tire equatorial plane E, but it may be arranged asymmetrically. Further, the rubber layer 15 may be arranged only on one sidewall portion 2. In this case, the rubber layer 15 may be placed on a portion located on the outside in the width direction of the vehicle when the tire is mounted on the vehicle. According to this, the rubber layer 15 can exhibit a function of improving cornering performance under conditions where a force acts on the tire in the tire width direction, such as when the vehicle turns.

1... Tread part 2... Sidewall part 3... Bead part 4... Bead core 5... Bead filler 6... Carcass 7... Chafer 8... Inner liner 9... Belt layer 10... Reinforcement layer 11A, 11B... Belt 12... Reinforcement belt 13... Carcass body part 14...Carcass winding upper part 15...Rubber layer

Claims (7)

Bead cores are placed on both sides of the tire width,
a pair of bead fillers arranged outward in the tire radial direction from the bead core;
a carcass main body portion that spans the bead core; and a carcass winding portion that extends from the outside of the bead core in the tire width direction beyond the bead filler to the outside in the tire radial direction;
a rubber layer disposed between the carcass main body and the carcass winding upper part,
The rubber layer has a length in the meridian direction of a region between the tire radial outer end of the bead filler and the tire radial outer end of the region where the carcass main body portion and the carcass winding portion overlap. Occupying at least 50% of the
The tire radial outer end of the carcass winding upper part is located on the tire radial outer side than the tire maximum width position,
The outer end of the rubber layer in the tire radial direction has a length of 10 mm in the meridian direction from the outer end of the carcass winding part in the tire radial direction toward the outside in the tire radial direction, and a length of 30 mm in the meridian direction toward the tire radial inside. Pneumatic tires located in the range of . Bead cores are placed on both sides of the tire width,
a pair of bead fillers arranged outward in the tire radial direction from the bead core;
a carcass main body portion that spans the bead core; and a carcass winding portion that extends from the outside of the bead core in the tire width direction beyond the bead filler to the outside in the tire radial direction;
a rubber layer disposed between the carcass main body and the carcass winding upper part;
Equipped with
The rubber layer has a length in the meridian direction of a region between the tire radial outer end of the bead filler and the tire radial outer end of the region where the carcass main body portion and the carcass winding portion overlap. Occupying at least 50% of the
The tire radial outer end of the carcass winding upper part is located on the tire radial outer side than the tire maximum width position,
The inner end of the rubber layer in the tire radial direction has a length of 30 mm in the meridian direction from the outer end of the bead filler in the tire radial direction toward the outside in the tire radial direction, and a length of 10 mm in the meridian direction toward the tire radial direction inside. Pneumatic tires located within the range. Bead cores are placed on both sides of the tire width,
a pair of bead fillers arranged outward in the tire radial direction from the bead core;
a carcass main body portion that spans the bead core; and a carcass winding portion that extends from the outside of the bead core in the tire width direction beyond the bead filler to the outside in the tire radial direction;
a rubber layer disposed between the carcass main body and the carcass winding upper part;
Equipped with
The rubber layer has a length in the meridian direction of a region between the tire radial outer end of the bead filler and the tire radial outer end of the region where the carcass main body portion and the carcass winding portion overlap. Occupying at least 50% of the
The tire radial outer end of the carcass winding upper part is located on the tire radial inner side than the tire maximum width position,
A pneumatic tire, wherein the outer end of the rubber layer in the tire radial direction is located within a range of 10 mm in length in the meridian direction toward the outer and inner sides of the tire radially from the outer end of the tire radial direction of the carcass winding portion. . According to claim 3 , the inner end of the rubber layer in the tire radial direction is located within a range of 10 mm in length in the meridian direction from the outer end of the bead filler toward the outer and inner sides of the tire radial direction. Pneumatic tires listed. The pneumatic tire according to any one of claims 1 to 4 , wherein the rubber layer has a thickness of 0.5 mm or more and 3.0 mm or less. The pneumatic tire according to any one of claims 1 to 5 , wherein the rubber layer has a thickness that differs depending on the position in the tire radial direction. The pneumatic tire according to any one of claims 1 to 6 , wherein the rubber layer has a lower hardness than the bead filler.

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