JP2013216207A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of improving handling stability and riding comfort performance and maintaining the improved state for a long period of time.SOLUTION: A pneumatic tire 10 includes a tread part 13, a pair of side parts 14 continuous with the tread part 13, a pair of bead parts 15 continuous with the side parts 14, having a bead core 19, a carcass layer 16 formed like a ring, striding over the pair of bead parts 15 through the tread part 13 and the pair of side parts 14, and a belt 17 provided in the tread part 13 radially outward of the carcass layer 16 in a circumferential direction of the tire. The pneumatic tire 10 includes a pair of pads 31 coming into contact with a tire inner surface 22 between an end in an axial direction of the belt 17 and an upper end of the bead core 19, and an elastically deformable supporter 32 provided between the pair of pads 31.

Description

  The present invention relates to a pneumatic tire.

  Patent Document 1 discloses a tire that lowers noise by disposing a sound absorbing layer made of a foamable rubber composition on the inner surface of the tire. The sound absorbing layer is disposed on the inner liner and vulcanized and bonded in the process of manufacturing a so-called green tire in which parts such as a carcass, a belt, a tread, a bead, and an inner liner are assembled by a molding machine. However, when the green tire is vulcanized, the inner surface of the tire is pressed together with a bladder together with a bladder, so that it is difficult to bond the sound absorbing layer while maintaining its shape. Therefore, in such an adhesive state, there is a possibility that the effect of reducing noise is not sufficiently exhibited.

  Patent Document 2 discloses a tire that reduces noise by placing an object having a hardness of 80 to 90 on the inner surface of at least one of a buttress portion and a filler portion to suppress vibrations. However, when the object is arranged on the inner surface of the tire, the riding comfort performance deteriorates. When the object is bonded and fixed, the distortion of the adhesive layer between the tire inner surface and the object increases during rolling of the tire, and the object may peel off.

  Patent Document 3 discloses a tire in which a dynamic damper having a mass body and an elastic member is disposed on the inner surface of the tire. The dynamic damper is designed to reduce noise by damping the axial deformation mode. However, when the dynamic damper is bonded and fixed, similarly to Patent Document 2, when the tire rolls, distortion of the adhesive layer between the tire inner surface and the dynamic damper increases, and the dynamic damper may be peeled off.

  Patent Document 4 discloses a tire disposed on the tire inner surface or rim in a state where two layers partitioning the internal air chamber of the tire are loosened. Each of the two layers is provided with a plurality of openings that allow air to move between one side and the other side of each layer. The plurality of openings are arranged so as not to overlap between the two layers. The two layers move in the internal air chamber of the tire in response to centrifugal force. At that time, the two layers pressurize or depressurize each space of the internal air chamber of the tire partitioned into the two layers. This attenuates the impact and converts the friction of the flow resistance element into heat to reduce noise. However, when the two layers are bonded and fixed, as in Patent Documents 2 and 3, distortion of the adhesive layer between the tire inner surface and the two layers increases during rolling of the tire, and the two layers are There is a risk of peeling.

Japanese Unexamined Patent Publication No. 01-254411 Japanese Patent Laid-Open No. 2001-1726 JP 2006-256531 A Special table 2011-518707 gazette

  An object of the present invention is to improve steering stability and riding comfort performance, and to maintain the improved state for a long period of time.

  As means for solving the problems, the tire according to the present invention includes a tread portion, a pair of side portions continuous with the tread portion, a pair of bead portions continuous with the side portion and having a bead core, and the tread portion. And a carcass layer provided in an annular shape across the pair of bead portions via the pair of side portions, and a belt provided in the tire circumferential direction on the tread portion on the radially outer side of the carcass layer A pair of pads that contact the inner surface of the tire between the axial end of the belt and the upper end of the bead core; and an elastically deformable support interposed between the pair of pads. I prepared.

  According to this configuration, since the pair of pads can be supported by the elastically deformable support body, the pads can be brought into contact with the tire inner surface while being urged. At this time, both ends of the support support the inner surface of the tire between the end portion in the axial direction of the belt and the upper end of the bead core via the pair of pads, so that the rigidity in the lateral direction of the tire can be increased. That is, steering stability can be improved. Moreover, vibration absorptivity can be improved by bringing the pad into contact with the tire inner surface. That is, riding comfort performance can be improved. Even when a force is applied to the pad from the tire inner surface and the pad is separated from the tire inner surface, the pad can be immediately brought into contact with the tire inner surface by elastic recovery of the support. Therefore, it is possible to improve the steering stability and the riding comfort performance and maintain the improved state for a long time. In particular, it is possible to eliminate the necessity of bonding and fixing the pad to the tire inner surface, and to allow the pad to move relative to the tire inner surface. Therefore, when the pad is bonded to the tire inner surface, strain is concentrated on the adhesive layer due to the movement of the tire, which is advantageous in that it is possible to avoid troubles in which the pad peels from the tire inner surface.

  It is preferable that the support has a length that allows the pad to be pressed against the inner surface of the tire. According to this configuration, the pad can be reliably brought into contact with the tire inner surface in a state where the pad is urged.

  It is preferable that the pad has a convex curved surface at least on a contact surface with the tire inner surface. According to this configuration, the contact surface of the pad with the tire inner surface can be ensured to the maximum, and the mounting stability of the pad on the tire inner surface can be improved.

  Preferably, the pad is made of flexible urethane foam, the support is made of a thermoplastic resin, and is fixed so that the end of the support is embedded in the pad. According to this configuration, the lateral rigidity and vibration absorbability of the tire can be reliably increased, and the pad and the support can be reliably connected.

  The support body is composed of one or more first support bodies and one or more second support bodies arranged so as not to interfere with each other, and at least a central portion of the first support body is curved convexly toward the outer peripheral side. And arranged so as not to interfere with the tread portion at the time of non-deformation, the second support body is arranged on the inner peripheral side of the first support body, and at least the central part is curved convexly toward the inner peripheral side, It is preferable that the bead portion and the rim for fixing the bead portion are arranged so as not to interfere with each other when not deformed. According to this configuration, the first support can be disposed so as not to interfere with the tread portion when not deformed, and the second support can be disposed so as not to interfere with the rim. At that time, the central portion of the first support is curved convexly toward the outer peripheral side, and the central portion of the second support is curved convexly toward the inner peripheral side. Therefore, the first support and the second support are curved. Can be reliably avoided.

  The support body is composed of one or more first support bodies and one or more second support bodies arranged so as not to interfere with each other, and the first support body is formed from the outer peripheral side of one pad. It arrange | positions so that it may bridge | crosslink to an inner peripheral side, and the said 2nd support body bridge | crosslinks from the inner peripheral side of said one pad to the outer peripheral side of said other pad so that it may cross | intersect said 1st support body. It is preferable that the first support body and the second support body are alternately arranged in the tire circumferential direction. According to this configuration, it is possible to reliably avoid interference between the first support and the second support.

  In the maximum deformation, it is preferable that the first support is disposed on the tread portion, and the first and second supports are disposed so that the second support does not interfere with the rim.

  According to the present invention, since the pair of pads can be supported by the elastically deformable support body, the pads can be brought into contact with the inner surface of the tire while being urged. At this time, both ends of the support support the inner surface of the tire between the end portion in the axial direction of the belt and the upper end of the bead core via the pair of pads, so that the rigidity in the lateral direction of the tire can be increased. That is, steering stability can be improved. Moreover, vibration absorptivity can be improved by bringing the pad into contact with the tire inner surface. That is, riding comfort performance can be improved. Even when a force is applied to the pad from the tire inner surface and the pad is separated from the tire inner surface, the pad can be immediately brought into contact with the tire inner surface by elastic recovery of the support. Therefore, it is possible to improve the steering stability and the riding comfort performance and maintain the improved state for a long time. In particular, it is possible to eliminate the necessity of bonding and fixing the pad to the tire inner surface, and to allow the pad to move relative to the tire inner surface. Therefore, when the pad is bonded to the tire inner surface, strain is concentrated on the adhesive layer due to the movement of the tire, which is advantageous in that it is possible to avoid troubles in which the pad peels from the tire inner surface.

The figure which shows the pneumatic tire concerning this invention. (A)-(d) is a figure which shows the example of the shape of a pad. (A) And (b) is a circumferential direction expansion | deployment figure of a core. The figure which shows the modification of the pneumatic tire concerning this invention. The figure which shows the structure of the core in which the support body which cross | intersects alternately is arrange | positioned. The figure which shows the modification of the pneumatic tire concerning this invention. FIG. The figure which shows the modification of the pneumatic tire concerning this invention. The figure which shows the modification of the pneumatic tire concerning this invention. The figure which shows the tire of the comparative example 1. FIG. The figure which shows the tire of the comparative example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a pneumatic tire (hereinafter referred to as a tire) 10 according to a first embodiment of the present invention. The tire 10 includes a tire body 11 and a core 12.

  The tire body 11 includes a tread portion 13, a pair of side portions 14 that are continuous with the tread portion 13, a pair of bead portions 15 that are continuous with the side portion 14, a tread portion 13, and a pair of side portions 14. And a carcass layer 16 provided in an annular shape across the bead portion 15.

  Two belts 17 having a constant width are provided on the tread portion 13 on the outer side in the tire radial direction of the carcass layer 16 so as to be arranged in the tire circumferential direction. The side portion 14 has a maximum width portion 18 that maximizes the tire width W. The bead portion 15 has a ring-shaped bead core 19. The bead core 19 is wound from the inner side to the outer side in the width direction of the tire 10 by the carcass layer 16 so as to be disposed in the bead portion 15 on the inner side in the tire radial direction. A bead filler 20 is disposed in the bead portion 15 on the outer side in the tire radial direction. The bead portion 15 is fixed to the rim 21. The carcass layer 16 is folded back so as to wind the bead core 19 and is terminated in the vicinity of the side portion 14.

  The core 12 includes a pad 31 and a support body 32.

  The pad 31 is in contact with the tire inner surface 22 between the axial end portion of the belt 17 and the upper end of the bead core 19 to absorb vibration. The pads 31 are connected to both ends of the support 32 and are provided as a pair. The pad 31 is formed in a ring shape in the circumferential direction of the tire 10. As shown in FIG. 2A, the cross-sectional shape of the pad 31 in the tire axial direction is a substantially rectangular shape in which the side in contact with the tire inner surface 22 is defined by a convex curve. The cross-sectional shape of the pad 31 is not limited to the shape, and may be any shape as long as it is along the tire inner surface 22, that is, a shape having a convex curved surface on the contact surface with the tire inner surface 22. For example, as shown in FIG. 2B, the cross-sectional shape of the pad 31 may be an ellipse. The cross-sectional shape of the pad 31 may be a crescent shape (FIG. 2 (c)), a semicircle, or a semi-ellipse (not shown) defined by a convex curve on the side in contact with the tire inner surface 22. As shown in FIG. 2D, the cross-sectional shape of the pad 31 may be a C-shape in which both tip portions are arranged on the tire inner surface 22 side. Although the maximum thickness T of the pad 31 is not specifically limited, 5-30 mm is desirable and 10-20 mm is especially desirable. The pad 31 is not particularly limited as long as it is a known material that can achieve the above-described effects, but a soft foam material is desirable, and a flexible urethane foam is particularly desirable.

  The support body 32 is interposed between the pair of pads 31 and 31 and is made of an elastically deformable material such as a thermoplastic resin. The material of the support 32 is polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS, SBS, polycarbonate (PC), fiber reinforced plastic (FRP), preferably carbon fiber (CFRP) or glass fiber. (GFRP) and the like. The support 32 has such a length that the pad 31 can be pressed against the tire inner surface 22. As shown to Fig.3 (a), the support body 32 is a circumferential direction continuous body. Moreover, the support body 32 may be a circumferential discontinuous body. Here, as shown in FIG. 3B, the circumferentially discontinuous support body 32 is a support body 32 having a gap between the support body 32 and the support body 32 adjacent to the support body 32. I mean. The support body 32 includes a first support body 33 and a second support body 34. Each of the first support 33 and the second support 34 may be composed of a plurality of supports. Desirably, the number of the support bodies 32 in the width direction is 2 to 4. The thickness of the support bodies 32 to 34 is 0.2 mm or more, and preferably 0.5 to 1 mm. The Young's modulus of the support 32 is preferably 500 MPa or more, and particularly preferably 1 to 3 GPa. The first support 33 and the second support 34 are arranged so as not to interfere with each other. The first support 33 is disposed so that the central portion 35 is curved in a convex shape toward the outer peripheral side and does not interfere with the tread portion 13 when not deformed. The second support 34 is disposed on the inner peripheral side of the first support 33, the central portion 36 is curved in a convex shape toward the inner peripheral side, and the rim that fixes the bead portion 15 and the bead portion 15 when not deformed. 21 is arranged so as not to interfere with 21. Further, the first support 33 and the second support 34 are disposed so that the first support 33 does not interfere with the tread portion 13 and the second support 34 does not interfere with the rim 21 during maximum deformation. As shown in FIGS. 2A to 2D, the end portion of the support 32 is fixed so as to be embedded in the pad 31. In the present embodiment, the end portion of the support body 32 is heat-sealed to the pad 31. You may fix the edge part of the support body 32 to the pad 31 by adhesion | attachment.

  Next, a method for attaching the core 12 to the tire 10 will be described. The core 12 is attached before the tire 10 is attached to the rim 21 of the wheel. The tire 12 is inserted into the tire 10 while applying a force to the core 12 so as to reduce the distance between the pair of pads 31 and 31. The pad 31 is arranged so that the center in the tire radial direction is located between the maximum width portions 18 and 18 of the tire inner surface 22. Since the first support 33 of the tire 10 is curved toward the tread portion 13 of the tire 10 and the second support 34 is curved toward the rim 21, the distance between the pair of pads 31 and 31 can be easily reduced. The core 12 can be smoothly mounted inside the tire 10. The pad 31 may contain a lubricant.

  According to the present invention, since the pair of pads 31 and 31 can be supported by the elastically deformable support body 32, the pad 31 can be brought into contact with the tire inner surface 22 in a biased state. At this time, both ends of the support body 32 support the tire inner surface 22 between the end portion in the axial direction of the belt 17 and the upper end of the bead core 19 via the pair of pads 31, 31. Stiffness can be increased. That is, steering stability can be improved. Further, by making the pad 31 contact the tire inner surface 22, vibration absorbability can be enhanced. That is, riding comfort performance can be improved. Even when a force is applied to the pad 31 from the tire inner surface 22 and the pad 31 is separated from the tire inner surface 22, the pad 31 can be brought into contact with the tire inner surface 22 immediately by the elastic recovery of the support 32. it can. Therefore, it is possible to improve the steering stability and the riding comfort performance and maintain the improved state for a long time. In particular, the necessity of bonding and fixing the pad 31 to the tire inner surface 22 can be eliminated, and the movement of the pad 31 with respect to the tire inner surface 22 can be allowed. Therefore, when the pad is bonded to the tire inner surface, strain is concentrated on the adhesive layer due to the movement of the tire, which is advantageous in that it is possible to avoid troubles in which the pad peels from the tire inner surface.

  In addition, the tire concerning this invention is not limited to the said embodiment, A various change is possible so that it may illustrate below.

  As shown in FIG. 4, the number of support bodies 32 may be three.

  As shown in FIG. 5, the core 12 may have a structure in which supports 33 and 34 that alternately intersect are arranged. The support body 32 is a circumferential discontinuous body (see FIG. 3B). In the structure, as shown in FIG. 6, the first support 33 is disposed so as to bridge from the outer peripheral side of one pad 31 to the inner peripheral side of the other pad 31, and the second support 34 It is arranged so as to cross-link from the inner peripheral side of one pad 31 to the outer peripheral side of the other pad so as to cross the one support 33. The first support 33 and the second support 34 are alternately arranged in the tire circumferential direction. The support body 32 includes one or more first support bodies 33 and one or more second support bodies 34 arranged so as not to interfere with each other.

  As shown in FIG. 7, the pad 31 may be a circumferential discontinuity.

  As shown in FIG. 8, the fixing positions of the pad 31 and the first support 33 and the second support 34 may be shifted outward in the tire radial direction, or as shown in FIG. It may be shifted.

(Example)
A pneumatic radial tire (195 / 65R15), a pad with a height of 25 mm (range: 20 to 80% of a cross-sectional height of 125 mm) is used as an evaluation tire, and the conventional example and comparative examples 1 to 3 are used under the following conditions. And about Examples 1-8, steering stability, riding comfort performance, and durability performance of the core were evaluated, and the results are shown in Table 1.

As a conventional example, a tire in which nothing is arranged on the tire inner surface was used.
As Comparative Example 1, a tire (FIG. 10) in which only the supports 33 and 34 were fixed inside the tire 10 was used. Both ends of the supports 33 and 34 are bonded to the tire inner surface 22 with an adhesive. The supports 33 and 34 are circumferential continuous bodies having no gap in the circumferential direction.
As Comparative Example 2, a tire (FIG. 11) in which only the pads 31 and 31 were bonded to the tire inner surface 22 with an adhesive was used.
As Comparative Example 3, the tire 10 of FIG. 1 was used. The pad 31 is bonded to the tire inner surface 22 with an adhesive.
As Example 1, the tire 10 of FIG. 1 was used.
As Example 2, the tire 10 of FIG. 4 was used.
As Example 3, a tire in which the support body 32 of the tire 10 of FIG. 1 was a circumferential discontinuity (see FIG. 3B) was used.
As Example 4, the tire 10 of FIG. 6 was used.
As Example 5, a tire in which the pad 31 of the tire 10 in FIG. 1 was a circumferential discontinuity (see FIG. 7) was used.
As Example 6, the tire 10 of FIG. 8 was used. The fixed position between the pad 31 and the first support 33 and the second support 34 is 10% from the outer periphery with respect to the height h of the pad 31.
As Example 7, the tire 10 of FIG. 1 was used. The fixed position between the pad 31 and the first support 33 and the second support 34 is 50% from the inner circumference with respect to the height h of the pad 31.
As Example 8, the tire 10 of FIG. 9 was used. The fixed position between the pad 31 and the first support 33 and the second support 34 is 10% from the inner periphery with respect to the height h of the pad 31.

Steering stability was comprehensively evaluated by two test drivers for starting, turning and braking on the test course.
Ride comfort was evaluated by two test drivers on the test course.
In the evaluation, the steering stability and riding comfort of the conventional example were set to 100, respectively. A value larger than 100 indicates that the performance is better than the conventional example, and a value smaller than 100 indicates that the performance is poor.
The durability performance of the core was evaluated using a high-speed durability test. In the high-speed durability test, an internal pressure of 280 kPa (maximum load load specified by JATMA) is applied to the evaluation tire (195 / 65R15), a drum test is performed in accordance with the conditions defined in ECE-R30, and the speed is increased every 10 minutes. Was increased by 10 km / h, and the drum running was continued until the pad failed (peeled from the inner surface of the tire), and the speed and distance traveled when the pad failed occurred. The value of the durability performance of the core was indexed with the value of Comparative Example 1 as 100. A value larger than 100 indicates that the performance is better than that of Comparative Example 1, and a value smaller than 100 indicates that the performance is poor.

  According to Table 1, the steering stability of the tire of Comparative Example 1 is 112, and the performance is improved compared to the conventional tire. However, the riding comfort is 98, which is lower than the conventional tire.

  In the tire of Comparative Example 2, the steering stability is 100, and the performance is not changed from that of the conventional tire. However, the riding comfort is 105, which is an improvement over the conventional tire. The durability of the core is 110, which is an improvement over the conventional tire.

  In the tire of Comparative Example 3, the steering stability is 112, and the performance is improved compared to the conventional tire. Moreover, the riding comfort is 105, which is an improvement over the conventional tire. The durability of the core is 105, which is an improvement over the conventional tire.

  In the tires of Examples 1 to 8, the handling stability, the riding comfort, and the durability of the core are all improved compared to the conventional tire.

  From the above, it can be seen that the tire of Comparative Example 1 cannot improve riding comfort performance compared to the conventional tire, and the tire of Comparative Example 2 cannot improve steering stability. Further, the tire of Comparative Example 3 can improve the handling stability, the riding comfort, and the durability of the core with respect to the conventional tire, but requires the pad adhesion.

  On the other hand, in the tires of Examples 1 to 8 of the present invention, the steering stability, the riding comfort, and the durability performance of the core are all compared to the conventional tire without bonding the pad 31 to the tire inner surface 22. Can be improved. Therefore, when the pad is bonded to the inner surface of the tire, it is possible to avoid the trouble that the strain concentrates on the adhesive layer due to the movement of the tire and the pad is peeled off from the inner surface of the tire. Then, when a force is applied to the pad 31 from the tire inner surface 22 and the pad 31 is separated from the tire inner surface 22, the pad 31 can be immediately brought into contact with the tire inner surface 22 by the elastic return of the support body 32. Steering stability and riding comfort performance can be improved, and the improved state can be maintained for a long time.

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 11 Tire main body 12 Core 13 Tread part 14 Side part 15 Bead part 16 Carcass layer 17 Belt 18 Maximum width part 19 Bead core 20 Bead filler 21 Rim 22 Tire inner surface 31 Pad 32 Support body 33 1st support body 34 1st 2 support body 35 center part 36 center part W tire width

Claims (7)

A tread portion, a pair of side portions continuous with the tread portion, a pair of bead portions continuous with the side portion and having a bead core, and straddling the pair of bead portions via the tread portion and the pair of side portions In a pneumatic tire comprising a carcass layer provided in an annular shape, and a belt provided in the tire circumferential direction on the tread portion on the radially outer side of the carcass layer,
A pair of pads that contact the inner surface of the tire between the axial end of the belt and the upper end of the bead core;
A pneumatic tire comprising: an elastically deformable support interposed between the pair of pads.   The pneumatic tire according to claim 1, wherein the support has a length that allows the pad to be pressed against the inner surface of the tire.   The pneumatic tire according to claim 1, wherein the pad has a convex curved surface at least on a contact surface with the tire inner surface.   The material of the said pad is a flexible urethane foam, The material of the said support body is a thermoplastic resin, The edge part of the said support body was fixed so that it might be embedded inside the said pad, The Claim 1 thru | or 3 characterized by the above-mentioned. The pneumatic tire according to any one of the above. The support body includes one or more first support bodies and one or more second support bodies arranged so as not to interfere with each other.
The first support is arranged so that at least the central portion is curved in a convex shape on the outer peripheral side and does not interfere with the tread portion when not deformed,
The second support body is disposed on the inner peripheral side of the first support body, and at least a central portion thereof is curved convexly toward the inner peripheral side, and the rim that secures the bead portion and the bead portion when not deformed. The pneumatic tire according to any one of claims 1 to 4, wherein the pneumatic tire is arranged so as not to interfere with the tire. The support body includes one or more first support bodies and one or more second support bodies arranged so as not to interfere with each other.
The first support is disposed so as to bridge from the outer peripheral side of one pad to the inner peripheral side of the other pad,
The second support is arranged so as to cross-link from the inner peripheral side of the one pad to the outer peripheral side of the other pad so as to intersect the first support.
The pneumatic tire according to any one of claims 1 to 4, wherein the first support body and the second support body are alternately arranged in the tire circumferential direction.   The said 1st support body is arrange | positioned at the time of maximum deformation | transformation, The said 1st and 2nd support body is arrange | positioned so that the said 2nd support body may not interfere with the said rim | limb. Pneumatic tires.

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