JP2011235667A - Tire noise reducing device and pneumatic tire equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire noise reducing device having reduced manufacturing cost and improved durability by preventing a sound absorbing material from separating from an inner peripheral face of a tire, while improving adaptability to various tire sizes.SOLUTION: The tire noise reducing device includes a sound absorbing material formed of a belt-like porous material and annularly mounted on the inner peripheral face of the tread part of the tire. At least at one of the ends of the belt-like sound absorbing material in the cross direction of the tire, a portion of the belt-like sound absorbing material folded to the side of a tire equator is formed at least on part of the annular periphery.

Description

  The present invention relates to a tire noise reduction device for reducing cavity resonance generated in a pneumatic tire and a pneumatic tire including the tire noise reduction device. More specifically, the present invention relates to a tire noise reduction device and a pneumatic tire including the tire noise reduction device that can achieve both reduction in manufacturing cost, improvement in durability, and adaptability to various tire sizes.

  In a pneumatic tire, one of the causes of noise generation is the generation of cavity resonance sound due to vibration of air filled in the tire. This cavity resonance sound is generated when the tread portion vibrates due to road surface irregularities when the tire rolls, and the vibration of the tread portion vibrates the air inside the tire.

  As a technique for reducing noise due to such a cavity resonance phenomenon, it has been proposed to install a sound absorbing material made of a porous material along the entire inner surface of a tread portion of a pneumatic tire (Patent Document 1,). 2).

  Here, as a method of installing the sound absorbing material made of a porous material along the inner surface of the tread portion of the pneumatic tire over the entire circumference, the restoring force of the linear spring member installed so as to penetrate the sound absorbing material is used. The elastic band member is arranged on the tire outer peripheral side of the sound absorbing material, and the locking member made of a thermoplastic resin is arranged on the tire inner peripheral side of the sound absorbing material. (Patent Document 3) and the like have been proposed in which the elastic band member and the locking member are thermally fused and urged through the sound absorbing material and fixedly installed.

  However, the method of using these linear spring members or elastic band members to fix the sound absorbing material along the inner surface of the tread portion is a sound absorbing material molded to a size suitable for each tire size. It is disadvantageous in terms of cost and productivity because it is necessary to process the material, and further, it is necessary to process the elastic band member and to assemble and process them with high accuracy.

JP 62-50203 A JP 2004-291855 A JP 2010-950 A

  In view of such a point, the present inventor does not use the linear spring member or the elastic band member described above, and the shape of both ends in the length direction of the sound absorbing material made of the band-shaped porous material is determined. By making it special, a tire noise reduction device has been proposed in which a belt-like sound absorbing material is formed in an annular shape so that the two ends intersect each other in a three-dimensional manner (Japanese Patent Application No. 2009-209976).

  The tire noise reduction device in which the belt-like sound absorbing material according to this proposal is formed in an annular shape can be installed by adjusting the degree of overlapping of the two ends in a three-dimensional manner according to each tire size. Therefore, it was excellent that it was possible to fit and fit to the inner peripheral surface of the tread portion of tires of various sizes.

  In particular, without using the above-described linear spring member or elastic band member, in addition to adjusting the degree of overlap, the repulsive force of the sound absorbing material itself allows the inner surface of the tread portion of tires of various sizes to be adjusted. It is excellent in that it can be fitted and installed.

  However, this proposal can use a sound absorbing material of the same size for tires of various sizes, but depending on the tire size, an annular sound absorbing material may be used when the tire equatorial plane is in the vertical direction. It has been found that there is a problem that the material does not support its own weight but behaves like buckling in the tire radial direction and peeling off from the inner peripheral surface of the tire, which may be inferior in durability.

  This is to form an annular shape by abutting the end of the band-shaped sound absorbing material, for example, by making the outer diameter somewhat larger than the inner diameter of the tire inner peripheral surface or the equivalent diameter, Even when a linear spring member or an elastic band member is used on the tire inner peripheral surface, it is considered that there may be a similar durability problem.

  In view of the above-described points, an object of the present invention is a tire noise reduction device that satisfactorily reduces cavity resonance generated in a pneumatic tire, and in particular, reduces the manufacturing cost and the tire inner periphery as described above. A tire noise reduction device that suppresses the behavior of the sound absorbing material from peeling off from the surface, improves durability, and achieves better adaptability to various tire sizes, and a pneumatic tire equipped with the tire noise reduction device It is to provide.

The tire noise reduction device of the present invention that achieves the above object has the following configuration (1).
(1) In a tire noise reduction device in which a sound absorbing material made of a band-shaped porous material is mounted in an annular shape on the inner peripheral surface of a tire tread, at least one of the end portions in the tire width direction of the band-shaped sound absorbing material Further, a tire noise reduction device characterized in that a portion where the belt-like sound absorbing material is folded back toward the tire equator is formed at least on a part of the annular circumference.

In the tire noise reduction device of the present invention, it is preferable that the tire noise reduction device has any one of the following configurations (2) to (6).
(2) The sound absorbing material made of the band-shaped porous material has the annular shape formed by abutting both end surfaces in the length direction of the sound absorbing material. Tire noise reduction device.
(3) The annular shape is configured by partially overlapping the sound absorbing material made of the band-shaped porous material so that both end portions in the length direction are arranged on the inner side of the outermost periphery. The tire noise reduction device according to (1) above, characterized in that
(4) The tire noise reduction according to any one of (1) to (3) above, wherein a tire mass adjusting portion is provided at a portion where the belt-shaped sound absorbing material is folded back toward the tire equator. apparatus.
(5) A portion where the band-shaped sound absorbing material is folded back toward the tire equator is at least partially bonded to a portion of the sound absorbing material other than the folded portion in the thickness direction of the sound absorbing material, or intermittently by a fastener. The tire noise reduction device according to any one of (1) to (4), wherein the tire noise reduction device is continuously engaged and fixed.
(6) The above-mentioned band-shaped sound absorbing material has a length in the range of 360 ° to 520 ° in the circumferential angle of the pneumatic tire as the length in the longitudinal direction (1) The tire noise reduction device according to any one of (1) to (5).

The pneumatic tire of the present invention that achieves the above-described object has the following configuration (7).
(7) A pneumatic tire, wherein the tire noise reduction device according to any one of (1) to (6) is mounted on an inner peripheral surface of a tread portion.

  According to the first aspect of the present invention, there is provided a tire noise reduction device that reduces the manufacturing cost and suppresses the behavior that the sound absorbing material peels off from the tire inner peripheral surface as described above, thereby realizing an improvement in durability. can do.

  According to the second aspect of the present invention, since the annular shape is formed by joining by butting together with the effects of the first aspect of the invention, there is less problem of weight increase and the shape of the annular sound absorbing material A tire noise reduction device that is excellent in terms of maintainability can be realized.

  According to the third aspect of the present invention, the tire noise has the effect of the first aspect of the invention and is excellent in that the applicable tire size is wide even if the sound absorbing material has the same size. A reduction device can be realized.

  According to the fourth aspect of the present invention, even when the mass balance is lost in the tire circumferential direction by configuring the sound absorbing material in an annular shape, the mass balance in the tire circumferential direction is provided particularly by providing the mass adjusting portion. Therefore, it is possible to provide a tire noise reduction device that can realize a tire excellent in ride comfort, durability, and the like.

  According to the fifth aspect of the present invention, it is possible to realize a tire noise reduction device that has good folding form maintainability and can maintain and exhibit the above-described effects of the present invention for a longer period of time.

  According to the sixth aspect of the present invention, the sound absorbing material has a length in the range of 360 ° to 520 ° (about 1 to 1.4 laps) in the circumferential angle of the pneumatic tire as the length in the longitudinal direction. By being present, it is possible to realize a tire noise reduction device that is not too long, has good workability, and can be manufactured at a relatively low manufacturing cost. In particular, when the mass adjustment unit is positively provided as in the tire noise reduction device of the present invention according to claim 4, the length of the sound absorbing material in the longitudinal direction of the pneumatic tire is set as in the configuration of claim 6. It is preferable that the entire mass balance can be easily achieved while keeping the circumferential angle in the range of 360 ° to 520 ° (about 1 to 1.4 laps).

  According to the pneumatic tire of this invention concerning Claim 7, the pneumatic tire which has the effect of the tire noise reduction apparatus of Claim 1 to 6 mentioned above is realizable.

(A), (b) is the external appearance perspective view which showed one Embodiment of the tire noise reduction apparatus of this invention. It is the partial cross section perspective view which showed one Embodiment of this invention pneumatic tire. (A)-(d) is a partial cross-sectional perspective view which showed the form which turned back the strip | belt-shaped sound absorption material used for the tire noise reduction apparatus of this invention to the tire equator side. (A)-(d) is the expanded view which showed embodiment of the strip | belt-shaped sound-absorbing material used for the tire noise reduction apparatus of this invention altogether. It is the external appearance perspective view which looked at the both-ends overlap part of the aspect of FIG.1 (b) from the tire inner peripheral surface side. The partial cross-sectional perspective view which showed the example which the part which folded the strip | belt-shaped sound-absorbing material engaged intermittently or continuously with the part of the sound-absorbing material other than this folded-back part in the thickness direction of a sound-absorbing material, or a fastener It is.

  Hereinafter, the tire noise reduction device of the present invention and a pneumatic tire including the same will be described in more detail with reference to the drawings.

  The tire noise reduction device of the present invention is a tire noise reduction device in which a sound absorbing material made of a band-shaped porous material is mounted in an annular shape on the inner peripheral surface of a tread portion of the tire, and the tire width of the band-shaped sound absorbing material A portion where the belt-like sound absorbing material is folded back toward the tire equator side is formed at least at a part of the annular circumference on at least one of the end portions in the direction.

  1 (a) and 1 (b) are external perspective views showing an embodiment of a tire noise reduction device 1 of the present invention, in which a sound absorbing material 2 made of a band-shaped porous material has an annular shape. In addition, at least one of the end portions of the band-shaped sound absorbing material 2 viewed in the tire width direction has a portion (folded portion) 2a where the band-shaped sound absorbing material 2 is folded back toward the tire equator, at least a part on the circumference of the ring Is formed.

  As shown in FIG. 2, the tire noise reduction device 1 is mounted on the inner peripheral surface of a tread portion 5 of a pneumatic tire. In FIG. 2, 6 is a bead part and 7 is a sidewall part.

  Since the sound absorbing material 2 is formed with the folded portion 2a, the bending rigidity is greatly improved, and even when the tire equatorial plane direction is in the vertical direction, the sound absorbing material 2 has a strong force to support its own weight as an annular body. Therefore, the tire noise reduction device 1 as a whole is excellent in durability because it does not buckle in the tire radial direction due to its own weight and peels off from the inner circumferential surface of the tire.

In the present invention, the sound absorbing material 2 has a porous structure and has a sound absorbing effect. The sound absorbing material has a porous structure having a large number of open cells, and can exhibit a predetermined sound absorbing performance based on the porous structure. As the porous material constituting the sound absorbing material, it is preferable to use polyurethane foam, and it is particularly preferable to use a material having a density of 12 to 30 kg / m ³ . The thickness of the sound absorbing material is preferably 5 to 50 mm, more preferably 5 to 20 mm, from the viewpoint of the sound absorbing effect and ease of work.

  The folded portion 2a is provided at the left end portion in the width direction of the sound absorbing material in FIG. 2, but may be on either side of the width direction end portion or on both end sides.

  Alternatively, depending on the position in the tire circumferential direction, it may be formed so that they are alternately located on one part and the other part of both ends in the width direction.

  The total length L of the folded portion in the tire width direction is preferably 5 to 100%, more preferably 10 to 90%, of the total width W of the sound absorbing material after the tire is assembled.

Examples of various aspects of the folded portions 2a of the sound absorbing material 2 are shown in FIGS.
FIG. 3A shows an example in which the folded portion 2a is provided at one end in the width direction, and L is about 45% of W.
FIG. 3B shows an example in which the folded portion 2a is provided at one end in the width direction, and L is about 100% of W.
In FIG. 3 (c), the folded portions 2a are provided at both ends in the width direction, the lengths L1 and L2 of the folded portions at both ends are substantially equal, and their sum L (= L1 + L2) is W An example of about 50% is shown.
In FIG. 3D, the folded portion 2a is provided at both ends in the width direction, and the length L1 of the folded portion at both ends is set to be greater than L2, and L (= L1 + L2) is the sum of them. ) Shows an example of about 50% of W.

  Among these embodiments, the embodiment shown in FIG. 3A is preferable in terms of ease of manufacture.

  Moreover, the sum total of the tire circumferential direction length of a folding | turning part has the inside of the range of 50-100% of the sound absorption material circumferential direction length after a tire assembly, More preferably, it is 75-100%.

  The direction of turning back at the turn-back portion may be either inside or outside in the tire radial direction. However, as shown in FIGS. 1 (a), 1 (b), and 2, it is on the inside in the tire radial direction. It is preferable to fold back. In this way, it is preferable that the folded portion is directly recognized by the wearer's vision because the folded portion can be mounted without making a mistake in the front and back of the sound absorbing material.

  In the present invention, it is preferable that the sound absorbing material made of a porous material in a stage before being mounted in an annular shape on the inner peripheral surface of the tread portion has a continuous belt-like form, The books may be connected in the longitudinal direction to be continuous, or may be continuously cut out from the continuous foam in the longitudinal direction.

  When the sound absorbing material made of a band-shaped porous material is formed in an annular shape, one preferable embodiment is that both end surfaces in the length direction of the sound absorbing material are abutted and joined. This form is an example shown in FIG. 1A, and the annular outermost diameter is equal to or smaller than the inner diameter of the inner surface of the tire tread so that the tire is deformed in the ground contact portion. Bending fatigue due to repeated deformation of the accompanying sound absorbing material is alleviated, and durability can be secured. The thing of this aspect is excellent in the point of the form maintenance property of a cyclic | annular sound-absorbing material with few problems that a mass balance collapses by the weight increase and installation of a sound-absorbing material. The developed view is as shown in FIG. 4A, in which 3 is a butt portion and the broken line is a fold line. The abutment may have a form in which the end portions overlap slightly.

  Further, the outermost diameter of the ring that forms the sound absorbing material in a ring shape is preferably 90% to the same degree (about 100%), more preferably about 92 to 99.8%, which is larger than the inner diameter of the inner surface of the tire tread. It is better to make it smaller. The annular body stays on the inner surface of the tire tread by being in contact with and supported by the inner surface of the tire, but if the maximum diameter is too small, the effect cannot be obtained, and vibration will occur because the inside of the tire will violate when rolling the tire. Moreover, if the diameter is too large, the sound absorbing material is damaged early due to repeated bending deformation caused by tire deformation at the ground contact portion, which is not preferable.

  Alternatively, when the sound absorbing material made of a band-shaped porous material is formed in an annular shape, both end portions in the length direction of the sound absorbing material made of a band-shaped porous material are arranged inside the outermost periphery. It is one preferable embodiment that the ring is formed by overlapping a part thereof. This form is an example shown in FIG. 1 (b), and the annular outermost diameter is adjusted by adjusting the degree of overlap of the overlapping portions in accordance with the size of the tire to be mounted. By forming an annular shape that is equal to or smaller than the inner diameter of the tread inner surface, bending fatigue due to repeated deformation of the sound absorbing material due to tire deformation at the ground contact part is mitigated, and durability is secured while being attached to the tire tread inner surface ing. The thing of this aspect is excellent at the point which can be mounted | worn with the tire of various sizes. The developed view is as shown in FIG. 4 (c) as an example, 4 is a double-sided overlapping portion, and the broken line is a folding line.

  In the portion 2a where the belt-like sound absorbing material is folded back on the tire equator side, a tire mass adjusting portion can be provided, particularly when the entire mass balance is lost when the sound absorbing material is formed in an annular shape. It is preferable to provide a tire mass adjusting portion in the sound absorbing material itself. FIG. 4B and FIG. 4D are developed views showing an example in which the tire mass adjusting portion 8 is provided on the sound absorbing material itself. In these examples, the example in which the tire mass adjusting portion 8 is formed in a convex shape is shown, but it may be formed and adjusted in a concave shape according to the balance situation. In particular, in the case of the form of FIG. 1B, when the mass at the both end overlapping portion 4 is reduced, it is desirable to form and adjust the concave shape.

  Further, the portion 2a of the belt-like sound absorbing material 2 folded back toward the tire equator is at least partially bonded to the portion of the sound absorbing material 2 other than the folded portion in the thickness direction of the sound absorbing material, or intermittently by a fastener. Or it is preferable that it is engaged and fixed continuously. This is because it is effective to stably maintain the structure provided with the folded portion for a longer time. Specifically, for example, it is preferable to engage and fix with a fastener such as eyelet 9 or / and adhesive layer 10 that penetrates the two layers of the sound absorbing material as shown in FIG. The adhesive is preferably thermally bonded using a hot-melt adhesive.

  The band-shaped sound absorbing material is installed so as to have a length in the range of 360 ° to 520 ° in the circumferential angle of the pneumatic tire as the length in the longitudinal direction installed in the pneumatic tire. It is preferable in terms of effects and mass balance. An angle larger than 360 ° means that the belt-like sound absorbing material is installed so as to overlap more than one turn. In the case of FIG. 1B, this angle is a central angle from one front end position of the band-shaped sound absorbing material to the other front end position.

  As shown in FIG. 2, the tire noise reduction device 2 described above is installed on the inner peripheral surface of the tread portion of the pneumatic tire and exhibits excellent sound absorption performance. FIG. 5 is an external perspective view of the both end overlapped portion of the aspect of FIG. 1B as viewed from the tire inner peripheral surface side.

  The tire noise reduction device 2 is a device in which the manufacturing cost is reduced, and the behavior that the sound absorbing material itself is peeled off by its own weight from the tire inner peripheral surface is suppressed, and the running durability is excellent. It has adaptability to.

Examples 1, 2, 3 and Comparative Example 1
As tire noise reduction devices, a total of four types of Examples 1, 2, and 3 and Comparative Example 1 were manufactured.

  As the sound absorbing material, foamed polyurethane (thickness 10 mm) is prepared as a belt-like porous material, and each tire size is 245 / 40R18 pneumatic tire, rim assembled at an air pressure of 220 kPa, and mounted on the inner peripheral surface of the tread. The test was performed in a stationary state (tire radial buckling test) and running durability test, and durability was evaluated.

  In Examples 1 to 3, one end in the width direction of a band-shaped sound absorbing material having a width of 260 mm was folded as shown in FIG. 3A to have a sound absorbing material width of 200 mm at the time of assembly. In the folded part, 24 eyelets as shown in FIG. 6 were used at equal intervals and used over the entire circumference.

  In Comparative Example 1, a sound absorbing material having a width of 200 mm was manufactured in one layer (no folded portion).

  The detail of the form of the tire noise reduction device formed in each annular shape is as follows.

  Comparative Example 1 is composed of a single-layered annular body in which both end portions are joined by butting without forming the folded portion.

  Example 1 has the butt structure shown in FIG. 1A, and the sound absorbing material has a circumferential length of 360 °.

  Example 2 has a partially overlapping structure shown in FIG. 1B, and the sound absorbing material has a circumferential length of 420 °.

  Example 3 has a partially overlapping structure shown in FIG. 1B, and the sound absorbing material has a circumferential length of 440 °, and the overlapping part is symmetric as shown in FIG. 4D. A convex portion-shaped (length 300 mm × width 25 mm) mass adjusting portion 8 is provided at a position.

  In each case, the annular outer diameter was 5 to 6% smaller than the inner diameter of the inner surface of the tire tread.

(1) Tire radial direction buckling test With the tire noise reduction device mounted on a pneumatic tire, the tire is stood with its equatorial plane in the vertical direction, and the tire noise reduction device buckled and peeled off by its own weight. It was determined by visual observation. The results are shown in Table 1 as “x” when buckling and peeling occurred, and “◯” when buckling and peeling did not occur.

(2) Running durability test Using a running test drum with a diameter of 1707 mm, each test tire equipped with a tire noise reduction device is continuously run at a load of 120 kPa and a speed of 81 km / h, and tire noise is reduced every 1000 km. It was determined whether or not the device was damaged (occurrence of peeling at the butting portion or cross-joint portion of the sound absorbing material or occurrence of peeling of the sound absorbing material from the inner surface of the tire tread). And about each test tire, the mileage until damage was confirmed was calculated | required, and relative superiority was evaluated. This test is a so-called acceleration test that is performed under severe conditions that forcibly cause damage and is evaluated by the total distance traveled until the damage occurs.

  The evaluation is performed by index evaluation in which the travel distance of Comparative Example 1 is set to 100, and the larger the value, the better the travel durability.

  The evaluation results are shown in Table 1. As can be seen from Table 1, the tire noise reduction device according to the present invention has no radial buckling, and is far superior to that of Comparative Example 1 in running durability.

1: Tire noise reduction device 2: Sound absorbing material 2a: Folded portion of sound absorbing material 3: Butting portion 4: Overlapping portion 5: Tread portion 6: Bead portion 7: Side wall portion 8: Mass adjusting portion 9: Eyelet 10: Adhesive layer L: Total length of the folded portion in the tire width direction W: Total width of the sound absorbing material after assembling the tire

Claims (7)

  In a tire noise reduction device configured such that a sound absorbing material made of a band-shaped porous material is mounted on the inner peripheral surface of a tread portion of the tire in a ring shape, at least one of the end portions in the tire width direction of the band-shaped sound absorbing material, A tire noise reduction device characterized in that a belt-like sound absorbing material is formed at least at a part on the circumference of the ring.   2. The tire noise reduction device according to claim 1, wherein the sound absorbing material made of the band-shaped porous material has the annular shape formed by abutting both end surfaces of the sound absorbing material in the length direction. .   The sound absorbing material made of the band-shaped porous material is characterized in that the ring is configured by overlapping a part so that both end portions in the lengthwise direction are arranged inside the outermost periphery. The tire noise reduction device according to claim 1.   The tire noise reduction device according to any one of claims 1 to 3, wherein a tire mass adjusting portion is provided at a portion where the belt-shaped sound absorbing material is folded back toward the tire equator.   A portion where the band-shaped sound absorbing material is folded back toward the tire equator is at least partially bonded to a portion of the sound absorbing material other than the folded portion and the thickness direction of the sound absorbing material, or intermittently or continuously by a fastener. The tire noise reduction device according to any one of claims 1 to 4, wherein the tire noise reduction device is engaged and fixed.   The band-shaped sound absorbing material has a length in a range of 360 ° to 520 ° in a circumferential angle of a pneumatic tire as a length in a longitudinal direction. The tire noise reduction device according to any one of the above.   A pneumatic tire, wherein the tire noise reduction device according to any one of claims 1 to 6 is mounted on an inner peripheral surface of a tread portion.

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