JP2010260412A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire which further suppresses noise arising from air-column tube resonance sound while securing the durability of sound absorbing bodies. <P>SOLUTION: In this pneumatic tire 1, circumferential grooves 18, which extend along tire circumferential direction R, are formed, and the sound absorbing bodies 100, which absorb sound generated from the circumferential grooves 18, are provided in the groove bottoms 17c of the circumferential grooves 18. The sound absorbing body 100 is equipped with: a mounting part formed in an annular shape along the tire circumference R of the groove bottom 17c; and a sound absorbing body main part, which is connected to the outside of the tire radial direction of the mounting part to absorb the air-column tube resonance sound generated from an air-column tube formed by the circumferential grooves 18 and a road surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire in which a circumferential groove extending along the tire circumferential direction is formed and a sound absorber is provided in the circumferential groove.

  Tires mounted on vehicles such as automobiles generate resonance noise generated from the air column tube formed by the circumferential groove and the road surface when the tread contacts the road surface, so-called noise caused by the so-called air column tube resonance sound. To do.

  Therefore, various methods for suppressing air column resonance noise have been proposed. For example, a method of embedding a sponge-like sound absorber in the circumferential groove is known (for example, Patent Document 1).

  In a tire in which such a sound absorber is embedded in a circumferential groove, the sound absorber absorbs sound energy with a void or a thin film covering the void due to the structure of a foam or nonwoven fabric, and converts it into thermal energy. Because of the conversion, air columnar resonance is suppressed.

JP 50-125403 A (page 1-2, FIG. 2)

  However, the conventional tire described above has the following problems. That is, as the rolling speed of the tire increases due to the improvement in vehicle performance and the like, the centrifugal force generated in the sound absorber increases, and the embedded sound absorber is easily detached from the circumferential groove. That is, there is a problem that the durability of the sound absorber is low and noise due to air columnar resonance cannot be reliably suppressed.

  Therefore, the present invention has been made in view of such a situation, and an object of the present invention is to provide a tire capable of suppressing noise caused by air column resonance sound while ensuring the durability of the sound absorber.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a circumferential groove (circumferential groove 18) extending along the tire circumferential direction (tire circumferential direction R) is formed and the groove bottom (groove bottom 17c) of the circumferential groove. ) Is provided with a sound absorbing body (sound absorbing body 100) that absorbs sound generated from the circumferential groove, and the sound absorbing body extends along the tire circumferential direction at the groove bottom. A sound absorption component that absorbs the air column resonance generated from the air column tube formed by the circumferential groove and the road surface, connected to the tire radial direction outer side of the mounting portion (mounting portion 102) formed in an annular shape. The gist is to include a body main body portion (sound absorber main body portion 104).

  According to the first feature of the present invention, the sound absorber is disposed at the groove bottom of the circumferential groove, so that the sound absorber is generated by the air column resonance generated from the air column tube formed by the circumferential groove and the road surface. Sound can be suppressed. Further, the sound absorber can be easily prevented from coming off from the circumferential groove by including an attachment portion formed in an annular shape along the tire circumferential direction at the groove bottom.

  Therefore, it is possible to provide a tire that can suppress noise caused by air columnar resonance while ensuring the durability of the sound absorber.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that the attachment portion can be expanded and contracted in the tire radial direction.

  The third feature of the present invention relates to the first or second feature of the present invention, and is summarized in that the attachment portion is foamed rubber in which connected bubbles are formed.

  A fourth feature of the present invention relates to any one of the first to third features of the present invention, and is summarized in that the sound absorber main body portion is formed of a nonwoven fabric.

  According to the characteristics of the present invention, it is possible to provide a tire that can further suppress noise caused by air column resonance noise while ensuring the durability of the sound absorber.

1 is an exploded perspective view showing a part of a pneumatic tire according to an embodiment of the present invention. It is sectional drawing which shows the circumferential groove | channel of the pneumatic tire which concerns on embodiment of this invention. It is an expanded sectional view along the tread width direction of the pneumatic tire concerning the embodiment of the present invention.

  Next, embodiments according to the present invention and other embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Embodiment]
In the present embodiment, (1) the configuration of the tire, (2) the detailed configuration of the circumferential groove, (3) the detailed configuration of the sound absorber, (4) comparative evaluation, and (5) the action and effect will be described.

(1) Configuration of Tire FIG. 1 is an exploded perspective view showing a part of a circumferential groove 18 according to an embodiment of the present invention.

  As shown in FIG. 1, the pneumatic tire 1 has a carcass layer 12 that is a skeleton of the pneumatic tire 1. An inner liner 13 that is a highly airtight rubber layer corresponding to a tube is provided on the inner side in the tire radial direction of the carcass layer 12. Both ends of the carcass layer 12 are supported by a pair of bead portions 14.

  A belt layer 15 is disposed outside the carcass layer 12 in the tire radial direction. The belt layer 15 includes a first belt layer 15a and a second belt layer 15b obtained by rubberizing a steel cord. The steel cords constituting the first belt layer 15a and the second belt layer 15b are arranged with a predetermined angle (for example, ± 25 degrees) with respect to the tire equator line CL.

  A tread portion 16 having a tread surface 16a that contacts the road surface is formed on the outer side in the tire radial direction of the belt layer 15 (the first belt layer 15a and the second belt layer 15b).

  A rubber block 17 and a circumferential groove 18 that extends along the tire circumferential direction R are formed in the tread portion 16. A plurality of circumferential grooves 18 are formed along the tire circumferential direction R. A sound absorbing body 100 is provided in the circumferential groove 18. The sound absorber 100 has a function of absorbing air columnar resonance generated from an air column tube formed between the circumferential groove 18 and the road surface. The sound absorber 100 will be described later.

(2) Detailed Configuration of Circumferential Groove Next, a detailed configuration of the circumferential groove in the present embodiment will be described with reference to FIGS.

  FIG. 2 is an enlarged cross-sectional perspective view of the circumferential groove 18. FIG. 3 is an enlarged view in which the circumferential groove 18 is enlarged in the cross-sectional view along the tread width direction W of the pneumatic tire 1.

  As shown in FIG. 1, the circumferential groove 18 is formed between adjacent rubber blocks 17 along the tread width direction W.

  As shown in FIG. 3, in the cross section of the pneumatic tire 1 along the tread width direction W and the tire radial direction, the circumferential groove 18 is formed by a side wall 17a, a side wall 17b, and a groove bottom 17c.

  The groove bottom 17 c is located between the side wall 17 a of one rubber block 17 and the side wall 17 b of the other rubber block 17. The groove bottom 17c continues to the side wall 17a and the side wall 17b.

  The length in the tire radial direction of the circumferential groove 18 is defined as a circumferential groove depth H. Specifically, the circumferential groove depth H indicates the length from the tread surface 16a to the groove bottom 17c along the tire radial direction.

  The maximum width of the groove width along the tread width direction W of the circumferential groove 18 is defined as a maximum width W1. Specifically, the maximum width W1 indicates the maximum width of the groove width along the tread width direction W from the side wall 17a of one rubber block 17 to the side wall 17b of the other rubber block 17 on the tread surface 16a.

(3) Detailed Configuration of Sound Absorbing Body Next, a detailed configuration of the sound absorbing body in the present embodiment will be described with reference to FIGS.

  As shown in FIG. 3, the sound absorber 100 includes an attachment portion 102 and a sound absorber main body portion 104. The attachment portion 102 is formed in an annular shape along the tire circumferential direction R on the groove bottom 17c. The attachment portion 102 can be expanded and contracted along the tire radial direction. Before the mounting portion 102 is attached to the pneumatic tire 1, the length of the inner surface along the groove bottom 17c of the mounting portion 102 is shorter than the length of the outer surface of the groove bottom 17c along the tire radial direction. Also good. Specifically, the attachment portion 102 is formed of foamed rubber in which connected bubbles are formed.

  The sound absorber main body portion 104 is connected to the outer side in the tire radial direction of the attachment portion 102 and absorbs air columnar resonance generated from the air column tube formed by the circumferential groove 18 and the road surface. Specifically, the sound absorber body portion 104 absorbs sound energy by a void or a thin film covering the void due to the structure of a foam or non-woven fabric, and converts noise generated by converting it into thermal energy. To reduce. As an optimal material for the sound absorber main body portion 104, a thin film of urethane can be cited. Other suitable materials for the sound absorber main body 104 include a nonwoven fabric, a synthetic sponge such as a natural sponge, and foamed rubber. For the nonwoven fabric, organic fibers such as polyamide synthetic fiber, aramid, and polyester can be used.

  When thin-film urethane is used as the sound absorber main body portion 104, the sound absorber thickness t, which is the thickness of the sound absorber 100 in the cross section along the tread width direction and the tire radial direction, is formed to be 0.1 mm to 1 mm. In order to obtain a more effective sound absorbing effect, the sound absorber thickness t is preferably 0.3 mm to 0.5 mm.

  The sound absorber width W2 of the sound absorber 100 along the tread width direction W is narrower than the maximum width W1. The sound absorber 100 is provided on the groove bottom 17 c of the circumferential groove 18. The length of the sound absorber 100 in the tire radial direction is defined as a sound absorber length h1. The sound absorber length h1 is shorter than the circumferential groove depth H.

(4) Comparative Evaluation Next, in order to further clarify the effect of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (4.1) Evaluation method and (4.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(4.1) Evaluation method As shown in Table 1, the amount of reduction in sound pressure level and durability were evaluated using three types of pneumatic tires having different sound absorber shapes. The amount of reduction in sound pressure level was evaluated using a bench noise measurement drum. In addition, the durability was evaluated as the degree of dropout of the sound absorber by running 200 km at a high speed. The evaluation result is displayed as an index with the reduction amount of the sound pressure level in the tire of Comparative Example 1 being 100. The numerical value means that the amount of reduction in the sound pressure level increases as the value exceeds 100. Specifically, 110 corresponds to 1 dB reduction.

  Data on the tire was measured under the following conditions.

・ Tire size: 175 / 70R13
-Vehicle type: Domestic car sedan-Internal pressure: Standard internal pressure described in ETRTO The tire of Comparative Example 1 is different from the pneumatic tire 1 described in the embodiment of the present invention in that the circumferential groove does not include a sound absorber.

  The tire of Comparative Example 2 differs from the pneumatic tire 1 described in the embodiment of the present invention in that a long sound absorber is bonded to the groove bottom of the circumferential groove with an adhesive.

  The tire of Example 1 is the same as the pneumatic tire 1 described in the embodiment of the present invention.

(4.2) Evaluation results Table 1 shows the results.

  According to the measurement results, as shown in Table 1, the tires of the example and the comparative example 2 were superior in the amount of reduction in the sound pressure level as compared with the tire of the comparative example 1. Further, in the tire of Comparative Example 2, a part of the sound absorber was dropped, but in the tire of the example, no drop of the sound absorber was confirmed.

(5) Action / Effect As described above, according to the present embodiment, the sound absorber 100 is disposed on the groove bottom 17c of the circumferential groove 18 by the circumferential groove 18 and the road surface. The air column resonance sound generated from the formed air column can be suppressed.

  Conventionally, when such a sound absorber 100 is disposed in the circumferential groove 18, the sound absorber 100 is firmly fixed to the circumferential groove 18 in order to resist the centrifugal force generated with the rolling of the pneumatic tire 1. There was a need to be done. For example, a method of adhering the sound absorber 100 to the circumferential groove 18 using an adhesive can be applied, but selection of a material suitable for adhesion of the sound absorber 100 and the circumferential groove 18 and a high adhesive force are required. That is, many conditions have been demanded to firmly fix the sound absorber 100 capable of suppressing the air column resonance sound to the circumferential groove 18.

  According to the present embodiment, the sound absorber 100 can be easily prevented from coming off the circumferential groove 18 by including the attachment portion 102 formed in an annular shape along the tire circumferential direction R on the groove bottom 17c. Therefore, it is possible to provide the pneumatic tire 1 that can suppress noise caused by air column resonance noise while ensuring the durability of the sound absorber.

  According to the present embodiment, the attachment portion 102 can be expanded and contracted in the tire radial direction. For this reason, the sound absorbing body 100 attached to the pneumatic tire 1 only by forming the circumferential groove 18 without providing a specially shaped locking portion or the like on the tread 16 is formed by the expansion and contraction of the sound absorbing body 100 to the groove bottom 17c. Fixed to. Therefore, the pneumatic tire 1 can easily prevent the sound absorber 100 from falling out of the circumferential groove 18. Further, since no adhesive or the like is used, the sound absorber 100 can be easily removed and replaced.

  According to this embodiment, the attachment portion 102 is a foamed rubber in which connected bubbles are formed. For this reason, the attachment part 102 can also absorb the air column resonance sound generated from the air column tube. Moreover, the elasticity with the tread 16 which forms the circumferential groove | channel 18 is also near, and it can deform | transform according to deformation | transformation of the tread of the pneumatic tire 1. FIG. For this reason, it is possible to more easily prevent the sound absorber 100 from falling out of the circumferential groove 18.

  According to this embodiment, since the sound absorber main body portion 104 is formed of a nonwoven fabric, the pneumatic tire 1 can reliably absorb sound by the sound absorber main body portion 104, and noise caused by air columnar resonance noise. Can be further suppressed.

  In the present embodiment, when the sound absorber 100 is configured by foamed rubber, sponge, or nonwoven fabric, when the pneumatic tire 1 rolls on a road surface on which a liquid exists, the sound absorber 100 is formed in the circumferential groove 18. Due to the pressure of the liquid that has entered, the circumferential groove 18 is compressed toward the groove bottom 17c. That is, when the pneumatic tire 1 rolls on the road surface where the liquid exists, the volume can be further increased and the drainage can be further improved.

(7) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows.

  In the embodiment described above, the sound absorber main body portion 104 of the sound absorber 100 is not limited to a non-woven fabric, a natural sponge, a synthetic sponge such as polyurethane, and a foamed rubber. For example, a synthetic resin such as expanded polystyrene may be used.

  In the embodiment described above, the sound absorber 100 may be attached only to the circumferential groove 18 from the tire equator line rather than the outer side in the tread width direction when the vehicle is attached. Further, the sound absorber 100 may be mounted in all the circumferential grooves 18.

  In the above-described embodiment, when high speed traveling is assumed, the attachment portion 102 may be further fixed to the groove bottom 17c with an adhesive or a double-sided tape. According to this, the sound absorber 100 is more firmly fixed.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Pneumatic tire, 12 ... Carcass layer, 13 ... Inner liner 14 ... Bead part 15 ... Belt layer, 15a ... 1st belt layer, 15b ... 2nd belt layer, 16 ... Tread part, 16a ... Tread surface, DESCRIPTION OF SYMBOLS 17 ... Rubber block 17a, 17b ... Side wall 17c ... Groove bottom 18 ... Circumferential groove | channel, 100 ... Sound absorber, 102 ... Attachment part, 104 ... Sound absorber main-body part

Claims (4)

A tire in which a circumferential groove extending along a tire circumferential direction is formed, and a sound absorbing body that absorbs sound generated from the circumferential groove is provided at a groove bottom of the circumferential groove,
The sound absorber is
An attachment part formed in an annular shape along the tire circumferential direction at the groove bottom,
A tire including a sound absorber main body portion that is connected to an outer side in a tire radial direction of the mounting portion and absorbs air column resonance sound generated from an air column tube formed by the circumferential groove and a road surface.   The tire according to claim 1, wherein the attachment portion can be expanded and contracted in a tire radial direction.   The tire according to claim 1 or 2, wherein the attachment portion is foamed rubber in which connected bubbles are formed.   The tire according to any one of claims 1 to 3, wherein the sound absorbing body main body portion is formed of a nonwoven fabric.

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