JP2015030307A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire which can improve vehicle exterior noise performance while maintaining rolling resistance performance.SOLUTION: A high-attenuation layer 6 made of rubber of which the loss tangent at 0°C is 0.3 or more is disposed at least at one place between a carcass layer 2a and an oblique belt layer 3a adjacent to the tire diameter direction outer side of the carcass layer 2a, or between layers of a plurality of oblique belt layers 3a, 3b adjacent to the tire diameter direction. Therein, the width of the oblique belt layer having smaller tire width direction width, of the oblique belt layers adjacent to the tire diameter direction outer side or inner side of the high-attenuation layer 6 is set as W, and a tire width direction region in which the tire width direction width extended respectively to the tire width direction inner side from a pair of tire width direction outer side edges of the oblique belt layer is 0.05 W is set as an end part region E, a tire width direction outer side edge 6o of the high-attenuation layer 6 is located on the tire width direction inner side than the end part region E.

Description

  The present invention relates to a pneumatic tire with improved outside noise performance while maintaining rolling resistance performance.

Noise in pneumatic tires is classified into outside noise and inside noise, and various noise reduction techniques have been studied. For example, Patent Document 1 proposes a tire in which an on-belt damping layer made of a high damping rubber that covers the end of the belt layer from the outside in the tire radial direction is provided to reduce high-frequency road noise for the purpose of reducing vehicle interior noise. .
However, in a pneumatic tire provided with such a high attenuation layer covering the end of the belt layer, noise outside the vehicle is not necessarily improved, and rolling resistance may deteriorate due to the amount of distortion generated at the end of the belt layer. was there.

Japanese Patent No. 3616863

  In view of the above, an object of the present invention is to provide a pneumatic tire with improved outside noise performance while maintaining rolling resistance performance.

A pneumatic tire according to the present invention includes a pair of bead portions, a carcass layer connected between the bead portions, and at least one inclined belt layer provided on the outer side in the tire radial direction of the carcass layer. And at least one point between the carcass layer and the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer, or between the plurality of inclined belt layers adjacent in the tire radial direction. , A high attenuation layer made of rubber having a loss tangent at 0 ° C. of 0.3 or more is provided, and the width in the tire width direction of the inclined belt layer adjacent to the outer side or the inner side in the tire radial direction of the high attenuation layer is provided. A tire having a width in the tire width direction of 0.05 W that extends inward in the tire width direction from a pair of outer edges in the tire width direction of the inclined belt layer, where W is the width of the inclined belt layer having a small width. When the end region of the direction area, the tire width direction outside edge of the high damping layer is characterized in that located inside the tire width direction than the end regions.
According to the pneumatic tire of the present invention, the noise performance outside the vehicle can be improved while maintaining the rolling resistance performance.

In the present invention, the “inclined belt layer” refers to a cord reinforcing layer made of a rubberized layer of a cord extending in an inclined manner with respect to the tire circumferential direction.
The above-mentioned “inclined belt layer having a small width in the tire width direction among the inclined belt layers adjacent to the outer side or the inner side of the high attenuation layer” refers to a plurality of inclinations in which the high attenuation layer is adjacent to the tire radial direction. When provided between the belt layers, among the inclined belt layers adjacent to the outer side and the inner side in the tire radial direction of each of the high attenuation layers, it refers to an inclined belt layer having a small width in the tire width direction. Is provided between the carcass layer and the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer, it indicates the inclined belt layer (the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer) And
Furthermore, in the present invention, “loss tangent at 0 ° C.” uses a sample piece (vulcanized rubber piece) having a thickness of 0.5 mm, a width of 5 mm, and a length of 20 mm, and a viscoelastic spectrometer (for example, Toyo Seiki) Measured under the conditions of an initial strain of 2%, a dynamic strain of 2%, a frequency of 50 Hz, and a temperature of 0 ° C.
Further, in the present invention, the dimensions such as the width in the tire width direction of the inclined belt layer and the high attenuation layer are measured in a no-load state in which a pneumatic tire is mounted on an applied rim and filled with a predetermined internal pressure. To do. Here, “applicable rim” is an industrial standard that is effective in the area where tires are produced and used. In Japan, JATMA YEAR BOOK of JATMA (Japan Automobile Tire Association), and in Europe, ETRTO (The European Tire and RIM Technical Organization's STANDARDDS MANUAL, TRA (THE TIRE AND RIM ASSOCIATION INC.) YEAR BOOK, etc. Rim), and “predetermined internal pressure” refers to the applicable size / ply described in JATMA YEAR BOOK, etc. It refers to the air pressure corresponding to maximum load capacity in computing.

In the pneumatic tire of the present invention, it is preferable that the high attenuation layer is provided between the carcass layer and the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer.
With this configuration, the outside noise performance can be further improved.

Further, in the pneumatic tire of the present invention, when the tire width direction region having a tire width direction width of 0.4 W and the center region is sandwiched around the tire equator plane, the inner edge in the tire width direction of the high attenuation layer However, it is preferable that it is located on the outer side in the tire width direction than the central region.
With this configuration, vehicle exterior noise performance and rolling resistance performance can be achieved at a higher level.

Furthermore, in the pneumatic tire of the present invention, it is preferable that the width of the high attenuation layer in the tire width direction is in a range of 0.1 W to 0.3 W.
With this configuration, vehicle exterior noise performance and rolling resistance performance can be achieved at a higher level.

  ADVANTAGE OF THE INVENTION According to this invention, the pneumatic tire which improved the noise performance outside a vehicle can be provided, maintaining rolling resistance performance.

1 is a partial cross-sectional view schematically showing a cross section in the tire width direction of a pneumatic tire according to a first embodiment of the present invention, and shows the arrangement of a high attenuation layer. It is a partial cross section figure which shows typically the tire width direction cross section of the pneumatic tire concerning a 2nd embodiment of the present invention, and shows arrangement of a high attenuation layer. It is a partial cross section figure which shows typically the tire width direction cross section of the pneumatic tire which concerns on 3rd Embodiment of this invention, and shows arrangement | positioning of a high attenuation layer.

Hereinafter, the pneumatic tire of the present invention will be described in detail by exemplifying an embodiment thereof with reference to the drawings.
FIG. 1 schematically shows a partial section in the tire width direction of the pneumatic tire according to the first embodiment of the present invention in an unloaded state in which the pneumatic tire is mounted on an applied rim and filled with a predetermined internal pressure.
A pneumatic tire 1 according to the first embodiment includes a pair of bead portions (not shown), a carcass 2 composed of a single carcass layer 2a connected between the bead portions in a toroidal shape, and a crown of the carcass 2 (carcass layer 2a). Of the two inclined belt layers 3a and 3b provided on the outer side in the tire radial direction of the portion and the circumferential belt layer 4a provided on the outer side in the tire radial direction of the inclined belt layers 3a and 3b so as to cover them. And a tread 5 provided on the outer side in the tire radial direction of the belt 3 (circumferential belt layer 4a), and an interlayer between the carcass layer 2a and the inclined belt layer 3a adjacent to the outer side in the tire radial direction of the carcass layer 2a. And a high attenuation layer 6 made of rubber having a loss tangent (tan δ) at 0 ° C. of 0.3 or more. Here, the width of the inclined belt layer in the tire width direction (hereinafter also simply referred to as “width”) is such that the width of the inclined belt layer 3b on the outer side in the tire radial direction is smaller than the width of the inclined belt layer 3a on the inner side in the tire radial direction. It is said that.
The tread 5 may be provided with a groove or the like as usual, but this is omitted in FIG. The same applies to FIGS. 2 and 3 described later.

  Here, the above-mentioned “circumferential belt layer” refers to a cord reinforcing layer composed of a rubberized layer of cords extending along the tire circumferential direction. The cord "extends along the tire circumferential direction" means that when the cord is parallel to the tire circumferential direction, and as a result of forming the belt layer by spirally winding a strip coated with rubber on the cord, etc. The case where the cord is slightly inclined with respect to the tire circumferential direction (inclination angle of about 5 ° with respect to the tire circumferential direction) is included.

The carcass 2 can be, for example, a radial carcass made of a single-layer radial carcass layer 2a made of an organic fiber cord, as in a general pneumatic tire. The carcass layer 2a and thus the structure of the carcass 2 is There is no particular limitation.
In the present embodiment, the belt 3 includes two inclined belt layers 3a and 3b and one circumferential belt layer 4a. However, in the present invention, the belt 3 has at least one inclined belt layer. As long as it is a thing, it is not limited to this structure. For example, the inclined belt layer can be one layer or three or more layers, the circumferential belt layer can be two or more layers, or can be divided in the tire width direction, or no circumferential belt layer can be provided. You can also
In the present invention, when a plurality of inclined belt layers are used, the cords inclined with respect to the tire circumferential direction forming each layer should intersect with each other between layers, so that the rigidity of the entire belt 3 can be sufficiently increased. From the viewpoint of ensuring, it is preferable. Thus, when it has a some inclined belt layer where a code | cord | chord cross | intersects between layers, the angle with respect to the tire peripheral direction of the code | cord | chord which forms each layer can be 15 degrees-35 degrees, for example. Further, the material of the cord forming the inclined belt layer is preferably steel from the viewpoint of ensuring the durability of the pneumatic tire, but is not particularly limited.
In addition, as a material of the cord forming the circumferential belt layer, steel can be used in addition to organic fibers generally used for pneumatic tires.

  In this embodiment, the high damping layer 6 made of rubber having a loss tangent of 0.3 or more at 0 ° C. is provided between the carcass layer 2a and the inclined belt layer 3a adjacent to the outer side in the tire radial direction of the carcass layer 2a. However, the high attenuation layer 6 includes the carcass layer 2a and the inclined belt layer 3a adjacent to the outer side in the tire radial direction of the carcass layer 2a, or a plurality of the inclined belt layers 3a adjacent in the tire radial direction. 3b may be provided in at least one place between the layers, for example, as shown in the second and third embodiments to be described later, divided into two places between one set of layers, or a plurality of sets It is also possible to place them between each of the layers.

In the pneumatic tire of the present invention, as shown in FIG. 1, the high attenuation layer 6 made of rubber having a loss tangent at 0 ° C. of 0.3 or more is adjacent to the outer side or the inner side of the high attenuation layer 6 in the tire radial direction. Among the inclined belt layers, the width of the inclined belt layer having a small width in the tire width direction (in the example of FIG. 1, the inclined belt layer 3a) is defined as W, and the (small width) inclined belt layer (in the example of FIG. 1, When the tire width direction region having a tire width direction width of 0.05 W and extending from the pair of tire width direction outer edges of the inclined belt layer 3a) to the inner side in the tire width direction is defined as the end region E, the high attenuation layer 6 The outer edge 6o in the tire width direction is located on the inner side in the tire width direction from the end region E, that is, the high attenuation layer 6 provided between the carcass layer and the inclined belt layer or between the inclined belt layers. But as a whole, the end region E It is necessary to be provided inside the tire width direction.
FIG. 1 also shows a central region C, which will be described later with respect to the second and third embodiments.

  The inventor analyzed the distribution of strain energy in the primary and secondary vibration modes of the tire cross section with respect to the pneumatic tire. On the other hand, the region of the outer end portion in the width direction is larger than the region on the inner side in the tire width direction. On the other hand, the strain energy in the secondary vibration mode having a strong correlation with the outside noise is on the inner side of the end region. It was found to be large in the area. Therefore, in order to achieve a high level of both rolling resistance performance and vehicle exterior noise performance, it is effective to devise the configuration of the rubber member in the tire width direction outer end region and the tire width direction inner region. It is conceivable that the inventor has made the present invention.

Specifically, in the present invention, as described above, the entire high attenuation layer 6 made of rubber having a loss tangent at 0 ° C. of 0.3 or more is interposed between the end region E and the inner layer in the tire width direction. According to this, rolling resistance performance is maintained by disposing a high attenuation layer having an effect of suppressing vehicle exterior noise only in a region having a strong correlation with vehicle exterior noise between layers such as an inclined belt layer. The outside noise performance can be improved.
In addition, according to said structure, the following secondary effects can also be acquired. That is, when the high damping layer 6 is provided in the end region of the inclined belt layer, separation due to shear deformation at the end of the inclined belt layer is likely to occur, and durability may be deteriorated. By providing the high attenuation layer 6 on the inner side in the tire width direction of the end region E, an effect of preventing deterioration in durability can be obtained.

In the present embodiment, the high attenuation layer 6 is also provided between the carcass layer 2a and the inclined belt layer 3a adjacent to the outer side in the tire radial direction of the carcass layer 2a.
Even if the high attenuation layer 6 is provided between the plurality of inclined belt layers, the outside noise performance can be improved while maintaining the rolling resistance performance. However, since the distortion energy in the secondary vibration mode of the cross section having a strong correlation with the outside noise is larger on the inner side in the tire radial direction, the high attenuation layer 6 is formed on the outer side in the tire radial direction of the carcass layer and the carcass layer as in the present embodiment. By providing between the inclined belt layers adjacent to each other, the effect of improving the outside-vehicle noise performance is greater than when the high attenuation layer 6 is provided between the plurality of inclined belt layers.

In the present invention, the width in the tire width direction of the high attenuation layer 6 is not particularly limited, but is preferably in the range of 0.1 W to 0.3 W on the basis of the width W. According to this configuration, It is possible to sufficiently improve the outside noise performance while more reliably maintaining the rolling resistance performance, and to make the outside noise performance and the rolling resistance performance compatible at a higher level.
When the high attenuation layer 6 is divided and disposed in the tire width direction between the same pair of carcass layers and / or inclined belt layers as in the second and third embodiments of the present invention described later, The width of the high attenuation layer 6 refers to the width of each of the high attenuation layers 6 arranged in a divided manner.

  In the present invention, the loss tangent at 0 ° C. of the rubber forming the high attenuation layer 6 is not particularly limited as long as it is 0.3 or more. However, from the viewpoint of suppressing rolling resistance, 0.7 or less is preferable. From the viewpoint of achieving both high performance and rolling resistance performance at a high level, it is particularly preferably from 0.3 to 0.5.

  In the embodiment shown in FIG. 1, as long as the high attenuation layer 6 having the above-described configuration is disposed between each of the one or more layers of the carcass layer, the inclined belt layer, and / or the circumferential belt layer, For example, an interlayer rubber layer other than the above-described high-attenuation layer, which is different from or the same type as the cord coating rubber usually provided in each layer, may be appropriately interposed, and this point is the same in other embodiments.

Next, other embodiments of the present invention will be described.
FIG. 2 shows a partial section in the tire width direction similar to FIG. 1 of a pneumatic tire according to a second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Also, the configuration and operational effects that are different from those of the first embodiment will be mainly described, and description of points that are basically the same as those of the first embodiment will be omitted.
In the pneumatic tire 1 according to the second embodiment, as illustrated in FIG. 2, the outer edge 6o in the tire width direction of the high attenuation layer 6 is located on the inner side in the tire width direction with respect to the end region E. When the tire width direction region with the tire width direction width of 0.4 W sandwiched between the tire equatorial plane CL is defined as the central region C, the tire width direction inner edge 6i of the high attenuation layer 6 is more than the central region C. Is also located on the outer side in the tire width direction. That is, in the present embodiment, the high attenuation layer 6 is provided only in the region between the central region C and the end region E.
Compared with the region between the central region C and the end region E, the central region C has less distortion energy in the cross-sectional secondary vibration mode having a strong correlation with the outside noise, but has a strong correlation with the rolling resistance. The strain energy in the primary vibration mode of the cross section does not change greatly. As a result of this distribution of strain energy, the central region C is less effective in improving the outside noise performance by providing the high attenuation layer 6 as compared with the region between the central region C and the end region E. By providing the high attenuation layer 6, the rolling resistance performance deteriorates to the same extent. For this reason, by providing the high attenuation layer 6 only in the region between the central region C and the end region E, it is possible to achieve both higher rolling resistance performance and vehicle exterior noise performance.

  In the second embodiment shown in FIG. 2, the high attenuation layer 6 is provided at two symmetrical positions in the tire width direction around the tire equatorial plane CL with the same width, depending on the purpose. As appropriate, it may be provided at an asymmetrical position and / or at a different width, or may be provided only at one place on one side across the tire equatorial plane CL.

FIG. 3 shows a partial section in the tire width direction similar to FIG. 1 of a pneumatic tire according to a third embodiment of the present invention. In the third embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted. In addition, the configuration and operational effects that are different from those of the above-described embodiment will be mainly described, and description of points that are basically similar to those of the above-described embodiment will be omitted.
In the pneumatic tire 1 according to the third embodiment, as shown in FIG. 3, the high damping layer 6 is provided between the two inclined belt layers 3 a and 3 b adjacent to each other in the tire radial direction. Further, as in the second embodiment, the outer edge 6o in the tire width direction of the high attenuation layer 6 is on the inner side in the tire width direction from the end region E, and the inner edge 6i in the tire width direction is the tire width from the center region C. It is located on the outside in the direction. That is, the high attenuation layer 6 is provided only in the region between the central region C and the end region E.
Even with the arrangement of the high attenuation layer 6 in this manner, both the rolling resistance and the vehicle exterior noise performance can be achieved by the same mechanism as in the first and second embodiments.

  In the present embodiment shown in FIG. 3, “the inclined belt layer having a small width in the tire width direction among the inclined belt layers adjacent to the outer side or the inner side in the tire radial direction of the high attenuation layer 6” is the inclined belt layers 3a and 3b. Therefore, the width W is the width of the inclined belt layer 3b, and the end region E is also a region extending from the pair of outer edges in the tire width direction of the inclined belt layer 3b. .

Hereinafter, the present invention will be described in more detail with reference to examples.
Pneumatic tires (test tires) of the examples and comparative examples having the configurations shown in Tables 1 and 2 were manufactured at a tire size of 155 / 65R14. The carcass was a radial carcass composed of one carcass layer, and polyethylene terephthalate was used as the material for the carcass layer cord. Further, on the outer side in the tire radial direction of the carcass (carcass layer), two inclined belt layers made of steel cords were arranged with the cords crossing each other. The inclination angle of the steel cord constituting the inclined belt layer with respect to the tire circumferential direction was 30 °. A circumferential belt layer made of a single nylon cord was disposed on the outer side in the tire radial direction of the inclined belt layer.
In Tables 1 and 2, the tire width direction region between the “central region” and the “end region” is described as the “intermediate region”.

(Evaluation of rolling resistance performance)
Each test tire was assembled to an applied rim, and after applying an internal pressure of 180 kPa, the rolling resistance of the axle was determined using a drum testing machine (speed: 80 km / h) having a steel plate surface with a diameter of 1.7 m. The rolling resistance was measured according to ISO18164, using a smooth drum and force type. The results are shown in Tables 1 and 2 as indices with the value of Comparative Example Tire 1 being 100. In any case, the smaller the value, the better. Examples where the index did not exceed 110 were judged to have relatively little deterioration in rolling resistance.

(Evaluation of external noise performance)
After assembling each test tire to the applicable rim, applying an internal pressure of 180 kPa, applying a load of 4.52 N on the running test drum, rotating at a speed of 40 km, 60 km, 80 km, and 100 km per hour, moving the microphone with noise (noise) ) Level was measured and the average of these measurements was calculated. The results are shown in Tables 1 and 2 in terms of noise reduction (dB) based on Comparative Example Tire 1. In any case, the larger the value, the better. An example in which the amount of noise reduction was 0.5 dB or more was judged to be particularly effective.

From Tables 1 and 2, the tires 1 to 4 can suppress the deterioration of the rolling resistance while effectively reducing the noise outside the vehicle as compared with the comparative tire 1 having no high attenuation layer. You can see that
In addition, the comparative tire 2 having the high attenuation layer also in the end region is excessively deteriorated in rolling resistance, and is similarly provided with an interlayer rubber layer having a loss tangent smaller than 0.3 in place of the high attenuation layer. It can be seen that the comparative tire 3 does not have a sufficient noise reduction effect.
From the results of Tables 1 and 2, it can be seen that according to the pneumatic tire of the present invention, the outside noise performance can be improved while maintaining the rolling resistance performance.

1: pneumatic tire, 2: carcass, 2a: carcass layer, 3: belt, 3a, 3b: inclined belt layer, 4a: circumferential belt layer, 5: tread, 6: high attenuation layer, 6i: high attenuation layer Inner edge in the tire width direction, 6o: Outer edge in the tire width direction of the high attenuation layer, C: Central region, E: End region, CL: Tire equatorial plane

Claims (4)

A pneumatic tire having a pair of bead portions, a carcass layer connected between the bead portions, and at least one inclined belt layer provided on the outer side in the tire radial direction of the carcass layer,
0 ° C. at least at one position between the carcass layer and the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer, or between the plurality of inclined belt layers adjacent in the tire radial direction. A high attenuation layer made of rubber having a loss tangent at 0.3 or more is provided,
Among the inclined belt layers adjacent to the outer side or the inner side of the high attenuation layer in the tire radial direction, the width of the inclined belt layer having a small width in the tire width direction is defined as W, and from the pair of tire width direction outer edges of the inclined belt layer When the tire width direction region having a tire width direction width of 0.05 W that extends inward in the tire width direction is an end region, the outer edge in the tire width direction of the high attenuation layer is more tire than the end region. Located inside in the width direction,
A pneumatic tire characterized by that.   2. The pneumatic tire according to claim 1, wherein the high damping layer is provided between the carcass layer and the inclined belt layer adjacent to the outer side in the tire radial direction of the carcass layer.   When a tire width direction region having a tire width direction width of 0.4 W sandwiched between the tire equator plane and the center region is a tire width direction inner edge of the high attenuation layer, the tire width direction is greater than the center region. The pneumatic tire according to claim 1 or 2, which is located outside. The pneumatic tire according to any one of claims 1 to 3, wherein a width in a tire width direction of the high attenuation layer is in a range of 0.1W to 0.3W.

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