JP6094620B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire that enables run-flat running with a load support, and more specifically, even when a load support is provided in a sidewall portion, rolling resistance and riding comfort during normal running are provided. The present invention relates to a pneumatic tire that can suppress the deterioration of the tire to a minimum and can improve the reusability after run-flat running.

  Conventionally, as a pneumatic tire that enables running in a punctured state by a load support, a side-reinforced pneumatic tire in which a side reinforcing layer made of a rubber composition is disposed inside a sidewall portion (for example, Patent Documents) 1-4) have been proposed.

  However, when a side reinforcing layer made of a rubber composition is integrally formed inside the sidewall portion, the side reinforcing layer enables run-flat driving, but rolling resistance and riding comfort during normal driving deteriorate. There is a problem. In particular, in a pneumatic tire having a large flatness ratio, i.e., a pneumatic tire having a large size in the tire radial direction of the sidewall portion, it is necessary to increase the volume of the side reinforcing layer. Deterioration of comfort becomes remarkable. Therefore, in a pneumatic tire having a large flatness ratio, a side reinforcing type run flat tire is not realized at present.

  Further, the side-reinforced pneumatic tire described above cannot be reused after run-flat running if the side reinforcing layer is damaged through run-flat running. Therefore, after run-flat running, even if there is no problem in the tire casing structure and the remaining groove of the tread part is left sufficiently, it is necessary to replace the tire itself, which is a resource saving viewpoint. Is not preferable.

Japanese Patent Laid-Open No. 7-3030412 JP 2003-94912 A JP 2007-98992 A JP 2009-61866 A

  The object of the present invention is to minimize the rolling resistance and the deterioration of riding comfort during normal running, even when a load support is provided on the sidewall portion, and after run flat running. An object of the present invention is to provide a pneumatic tire that can improve reusability.

In order to achieve the above object, a pneumatic tire according to the present invention includes a tread portion that extends in the tire circumferential direction to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and the sidewall portions. In a pneumatic tire provided with a pair of bead portions arranged on the inner side in the tire radial direction of
A load support extending along the tire circumferential direction is disposed inside each sidewall portion, and the load support is detachably attached to the inner surface of the sidewall portion via a mechanical engagement tool. It is characterized by this.

  As a result of diligent research on the run-flat running of pneumatic tires, the inventor has found that the load support disposed inside the sidewall portion is encased by the sidewall portion during the run-flat running. Even when the load support is fixed to the inner surface of the sidewall portion via the joint, it has been found that run-flat running can be stably continued, and the present invention has been achieved.

  That is, in the present invention, a load support extending along the tire circumferential direction is disposed inside each sidewall portion, and the load support is disposed on the inner surface of the sidewall portion via a mechanical engagement tool. It is possible to achieve stable run-flat running, and compared with the case where a side reinforcing layer made of a rubber composition is integrally formed inside the sidewall portion as in the past, during normal running. Rolling resistance and deterioration of riding comfort can be minimized. In addition, since the load support is detachably attached to the inner surface of the sidewall portion via a mechanical engagement tool, even if the load support is damaged during run-flat running, only the load support is replaced. By doing so, the tire itself can be reused, and the reusability after run-flat running can be improved. Moreover, the configuration as described above can be applied to a pneumatic tire having a large flatness ratio (for example, a flatness ratio of 65% or more), and a run-flat tire can be easily manufactured.

  In the present invention, the mechanical engagement tool is preferably a pair of hook-and-loop fasteners. According to the pair of hook-and-loop fasteners, the load support can be easily attached and detached, and the load support can be stably held during run-flat travel.

  More specifically, the pair of hook-and-loop fasteners are composed of hook-side hooks and loop-side hook-and-loop fasteners, hook-side hook-and-loop fasteners are vulcanized and bonded to the inner surface of the sidewall portion, and loop-side hook-and-loop fasteners are attached. It is preferable to attach to the load support. According to such a form, a load support body can be stably hold | maintained in run flat driving | running | working.

Further, it is preferable that the shear shear force when the pair of hook-and-loop fasteners are engaged is 0.6 kg / cm ² or more and the peel strength is 200 g / cm or more. Thereby, the holding | maintenance capability of the load support body in run flat driving | running | working can fully be ensured. The shear shear force (tensile shear strength) and peel strength (peel strength) are measured according to JIS-L3416.

  In the present invention, the mechanical support is disposed in a partial region of the surface where the load support contacts the inner surface of the sidewall portion during run-flat traveling, and the mechanical support is not provided in other regions. A structure in which the load support is in direct contact with the inner surface of the sidewall portion is preferable. In this case, the contact area between the load support and the sidewall portion during normal traveling can be reduced, and rolling resistance and riding comfort during normal traveling can be effectively suppressed.

  In this case, it is preferable to provide a projection for locking the end portion of the load support body during run flat running on the inner surface of the sidewall portion. Thereby, the integrity of the load support body and the sidewall portion during the run-flat running can be enhanced.

  In addition, the load support body has an outer wall surface that contacts the inner surface of the sidewall portion and an inner wall surface facing the tire lumen, and the inner wall surface is a flat surface or a curved surface that is recessed outward in the tire width direction. preferable. By prescribing the shape of the inner wall surface of the load support as described above, the force acting to push the load support inward in the tire width direction during run-flat travel is alleviated, and the load support during run-flat travel is reduced. It can be held stably.

  The load support may have a plurality of divided pieces that are divided in the tire radial direction, and these divided pieces may be in contact with each other during run-flat travel. In this case, it is possible to secure good durability by fixing each divided piece with a mechanical engagement tool, and in addition to the case where the load support is integrated, the rolling resistance and riding comfort during normal running are increased. Can be prevented.

  The hardness of the plurality of divided pieces constituting the load support can be different from each other. By making the hardness of the plurality of divided pieces different from each other, it is possible to arbitrarily adjust the characteristics during run-flat travel. For example, when the hardness of the plurality of divided pieces is gradually reduced toward the inner side in the tire radial direction, durability during run-flat running can be improved.

  It is preferable that the load support is accommodated in a bag, and the bag is attached to the inner surface of the sidewall portion by a mechanical engagement tool. In this case, since direct contact between the load support and the sidewall portion is minimized, it is possible to effectively suppress deterioration in rolling resistance and riding comfort during normal traveling.

  The load support is preferably made of rubber or a resin having a melting point or a thermal decomposition temperature of 150 ° C. or higher. Such a material is suitable as a constituent material of the load support.

It is meridian sectional drawing which shows the pneumatic tire which consists of embodiment of this invention. FIG. 2 is a meridian cross-sectional view showing a state where a load support is removed from the pneumatic tire of FIG. 1. It is sectional drawing which shows a pair of hook-and-loop fastener used as a mechanical engagement tool in the pneumatic tire of FIG. It is a perspective sectional view showing the pneumatic tire of FIG. It is a perspective sectional view showing a pneumatic tire provided with a load supporter intermittently arranged along the tire circumferential direction. FIG. 2 is a meridian cross-sectional view showing a run-flat running state of the pneumatic tire of FIG. 1. It is meridian sectional drawing which shows the principal part of the pneumatic tire of FIG. It is meridian sectional drawing which shows the principal part of the pneumatic tire provided with the load support body from which the shape of an inner wall surface differs. It is meridian sectional drawing which shows the principal part of the pneumatic tire which provided the processus | protrusion in the inner surface of the sidewall part. FIG. 10 is a meridian cross-sectional view showing a run-flat running state of the pneumatic tire of FIG. 9. It is meridian sectional drawing which shows the pneumatic tire provided with the load support body which has the some division | segmentation piece divided | segmented into the tire radial direction. FIG. 12 is a meridian cross-sectional view showing a run-flat running state of the pneumatic tire of FIG. 11. It is sectional drawing which shows the principal part of the pneumatic tire provided with the other load support body which has the some division | segmentation piece divided | segmented into the tire radial direction. It is sectional drawing which shows the principal part of the pneumatic tire provided with the further another load support body which has a some division | segmentation piece divided | segmented into the tire radial direction. It is meridian sectional drawing which shows the principal part of the pneumatic tire provided with the load support body accommodated in the bag body. It is meridian sectional drawing which shows the principal part of the pneumatic tire provided with the other load support body accommodated in the bag body.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show a pneumatic tire according to an embodiment of the present invention. In FIG. 1, the reinforcing structure of the pneumatic tire is depicted, but the reinforcing structure is not illustrated in other drawings.

  As shown in FIG. 1, the pneumatic tire of this embodiment includes a tread portion 1 that extends in the tire circumferential direction and has an annular shape, and a pair of sidewall portions 2 that are disposed on both sides of the tread portion 1. A pair of bead portions 3 are provided inside the sidewall portions 2 in the tire radial direction.

  At least one carcass layer 4 is mounted between the pair of bead portions 3 and 3. The carcass layer 4 includes a plurality of carcass cords oriented in the tire radial direction. The carcass layer 4 is folded from the tire inner side to the outer side around the bead core 5 disposed in each bead portion 3. An organic fiber cord is preferably used as the carcass cord of the carcass layer 4.

  On the other hand, a plurality of belt layers 6 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 6 include a plurality of reinforcing cords inclined with respect to the tire circumferential direction, and are arranged so that the reinforcing cords cross each other between the layers. In the belt layer 6, the inclination angle of the reinforcing cord with respect to the tire circumferential direction is set in a range of, for example, 10 ° to 40 °. A steel cord is preferably used as the reinforcing cord of the belt layer 6.

  In addition, although the tire reinforcement structure mentioned above shows the typical example in a pneumatic tire, it is not limited to this.

  In the pneumatic tire, a load support 11 extending along the tire circumferential direction is arranged inside each sidewall portion 2. Such a load support 11 needs to be arranged at least inside the side wall part 2 on one side, but is preferably arranged inside the side wall parts 2 on both sides. As shown in FIG. 4, the load support 11 is preferably continuous in the tire circumferential direction. However, it is also possible to dispose the load support 11 intermittently along the tire circumferential direction (see FIG. 5). When the load support 11 is an annular body that is continuous in the tire circumferential direction, it can be inserted into a pneumatic tire by deforming it into an elliptical shape. On the other hand, when the load support 11 is a small piece that is intermittently disposed along the tire circumferential direction, it can be easily inserted into the pneumatic tire.

  The load support 11 is made of rubber or resin. When the load support 11 is made of rubber, the JIS-A hardness is preferably in the range of 55 to 90. When the load support 11 is made of a resin, the melting point or thermal decomposition temperature of the resin is preferably 150 ° C. or higher. In other words, since the temperature of the load support 11 rises during run-flat travel, plastic deformation of the load support 11 can be prevented by using a resin having a melting point or a thermal decomposition temperature of 150 ° C. or higher. In particular, when the load support 11 is made of a resin, a thermosetting resin foam may be used.

  The load support 11 is detachably attached to the inner surface of the sidewall portion 2 via a mechanical engagement tool 12. The mechanical engagement tool 12 is a connecting means including a pair of engagement tools that enables mechanical engagement, and includes, for example, a pair of hook-and-loop fasteners and a pair of buttons. 1 to 4, a pair of hook-and-loop fasteners 13A and 13B (see FIG. 3) is used as the mechanical engagement tool 12. The hook-side hook-and-loop fastener 13A is fixed to the inner surface of the sidewall portion 2 by, for example, vulcanization bonding, and the loop-side hook-and-loop fastener 13B is fixed to the load support 11 by, for example, an adhesive. According to such a pair of hook-and-loop fasteners 13A and 13B, the load support 11 can be stably held during run-flat travel.

A pair of surface fasteners 13A, shear shearing force in the engaged state of 13B is 0.6 kg / cm ² or more, more preferably, may is ^{0.7kg / cm 2 ~2.5kg / cm 2} . The peel strength in the engaged state of the pair of hook-and-loop fasteners 13A and 13B is 200 g / cm or more, and more preferably 250 g / cm to 800 g / cm. Thereby, the holding | maintenance capability of the load support body 11 in a run flat driving | running | working can fully be ensured. When the shear shear force or peel strength is too small, the holding ability of the load support 11 in the run-flat running is lowered. In order to ensure such shear shear force or peel strength, in the loop-side hook-and-loop fastener 13B, the height of the loop material from the base material surface is preferably set in the range of 0.5 mm to 4.0 mm.

  In the pneumatic tire described above, the load support 11 extending along the tire circumferential direction is disposed inside each sidewall portion 2, and the load support 11 is mechanically engaged with the inner surface of the sidewall portion 2. Since the pneumatic tire is punctured since it is mounted via the joint 12, the load support 11 is enveloped by the bent sidewall portion 2 as shown in FIG. Run flat running becomes possible. In particular, by performing vulcanization without applying a release agent to the tire inner surface during tire vulcanization, the frictional force of the load support 11 on the tire inner surface increases, and the stability of run-flat running can be improved.

  On the other hand, since the load support 11 is not integrally formed with the sidewall portion 2, a side reinforcing layer made of a rubber composition is integrally formed inside the sidewall portion 2 as in the prior art. Compared to the case, it is possible to minimize the deterioration of rolling resistance and riding comfort during normal driving. That is, since the load support 11 mounted via the mechanical engagement tool 12 has little influence on the bending characteristics of the sidewall portion 2, the rolling resistance and riding comfort are not substantially deteriorated.

  Further, since the load support 11 is detachably attached to the inner surface of the sidewall portion 2 via the mechanical engagement tool 12, even if the load support 11 is damaged during the run flat running, the load support 11 The tire itself can be reused by exchanging only the body 11. Therefore, the pneumatic tire provided with the detachable load support 11 as described above is excellent in reusability after run-flat running.

  In addition, the configuration as described above can be applied to a pneumatic tire having a large flatness ratio, and there is an advantage that it is easy to manufacture a run-flat tire. Of course, it is also possible to optimize the physical properties of the load support 11 according to the load conditions and the like.

  As shown in FIGS. 1 and 6, in the pneumatic tire, the mechanical engagement tool 12 is disposed in a partial region of the surface where the load support 11 comes into contact with the inner surface of the sidewall portion 2 during run flat running. In other regions, a structure in which the load support 11 directly contacts the inner surface of the sidewall portion 2 without using the mechanical engagement tool 12 is employed. More specifically, the mechanical engagement tool 12 is selectively disposed only in a region outside the load support 11 in the tire radial direction. In this case, the contact area between the load support 11 and the sidewall portion 2 during normal traveling is reduced, and it is possible to effectively suppress deterioration in rolling resistance and riding comfort during normal traveling. However, even when the mechanical support 12 is disposed over the entire area where the load support 11 contacts the inner surface of the sidewall portion 2 during run-flat travel, rolling resistance and riding comfort during normal travel are improved. Is possible.

  The load support 11 includes an outer wall surface 11a (a wall surface on the outer side in the tire width direction) that contacts the inner surface of the sidewall portion 2 and an inner wall surface 11b (a wall surface on the inner side in the tire radial direction) that faces the tire lumen side. However, the inner wall surface 11b is preferably a flat surface (see FIG. 7) or a curved surface (see FIG. 8) that is recessed outward in the tire width direction. As shown in FIG. 6, a force F that pushes the load support 11 toward the inner side in the tire width acts during run-flat travel, but by defining the shape of the inner wall surface 11b of the load support 11 as described above. In addition, the force F acting to push the load support 11 inward in the tire width direction during run-flat travel can be relaxed, and the load support 11 can be stably held during run-flat travel. In particular, when the inner wall surface 11b is a curved surface that is recessed toward the outer side in the tire width direction, the load support 11 can be more stably held when the sidewall portion 2 is bent during run-flat travel.

  9 and 10 show a pneumatic tire having protrusions on the inner surface of the sidewall portion. In FIG. 9, a projection 14 is formed on the inner surface of the side wall portion 2 to lock the end portion of the load support 11 during run flat running. Thus, when the protrusion 14 which latches the edge part of the load support body 11 is provided in the inner surface of the sidewall part 2, as shown in FIG. 10, the edge part of the load support body 11 protrudes at the time of run-flat driving | running | working. Since it is latched by 14, the integrity of the load support body 11 and the sidewall part 2 can be improved. As a result, it is possible to improve the stability during run-flat running.

  FIG.11 and FIG.12 shows the pneumatic tire provided with the load support body which has the some division | segmentation piece divided | segmented into the tire radial direction. In FIG. 11, the load support 11 has a plurality of divided pieces 15a, 15b, and 15c divided in the tire radial direction, and the divided pieces 15a to 15c are in contact with each other during run-flat travel. In FIG. 11, the divided pieces 15a to 15c are completely independent. Each of the divided pieces 15 a to 15 c is detachably attached to the inner surface of the sidewall portion 2 via the mechanical engagement tool 12.

  As shown in FIG. 12, when the pneumatic tire is punctured, the load supporting body 11 composed of the divided pieces 15 a to 15 c is encased by the bent sidewall portion 2, and stable run-flat traveling is performed. Is possible. In such a configuration, it is possible to ensure good durability by fixing the divided pieces 15a to 15c with the mechanical engagement tool 12, and moreover, as compared with the case where the load support 11 is integrated. Deterioration of rolling resistance and riding comfort during traveling can be suppressed.

  Moreover, although the hardness of the some division | segmentation piece 15a-15c which comprises the load support body 11 is good also as constant, you may make it mutually differ as needed. By making the hardness of the plurality of divided pieces 15a to 15c different from each other, it is possible to arbitrarily adjust the characteristics during run-flat travel. For example, when the hardness of the plurality of divided pieces 15a to 15c is gradually reduced toward the inner side in the tire radial direction, durability during run-flat traveling can be improved.

  FIGS. 13 and 14 show a pneumatic tire provided with another load support having a plurality of divided pieces divided in the tire radial direction. The divided pieces 15a to 15c constituting the load support 11 may be completely independent, but as shown in FIGS. 13 and 14, some of them may be connected to each other. Moreover, as shown in FIG. 14, it is preferable that the divided pieces 15 a to 15 c are connected to each other via the bending portion 16. Providing such a curved portion 16 makes it difficult for cracks to occur between the divided pieces 15a to 15c.

  FIG.15 and FIG.16 shows the pneumatic tire provided with the load support body accommodated in the bag body, respectively. In FIG. 15, the load support 11 is accommodated in a bag 17, and the bag 17 is detachably attached to the inner surface of the sidewall portion 2 by a mechanical engagement tool 12. On the other hand, in FIG. 16, a load support 11 having a plurality of divided pieces 15 a to 15 c is accommodated in a bag 17, and the bag 17 is mechanically engaged with the inner surface of the sidewall portion 2 by the engagement tool 12. And is detachably mounted. Only a part of the load support body 11 (for example, an inner wall surface facing the tire lumen) is fixed to the bag body 17, and other parts are freely displaced with respect to the bag body 17. It is in a state that can be. Further, at least a part of the bag body 17 is constituted by a loop-side surface fastener, and the bag body 17 itself constitutes a part of the mechanical engagement tool. When the load support 11 is mounted on the inner surface of the sidewall portion 2 using such a bag body 17, direct contact between the load support 11 and the sidewall portion 2 is minimized. The deterioration of rolling resistance and riding comfort can be effectively suppressed.

In a pneumatic tire having a tire size of 265 / 60R18, a load support extending along the tire circumferential direction is disposed inside each sidewall portion, and the load support is machined against the inner surface of the sidewall portion. Tires of Examples 1 to 7 that were detachably mounted via a mechanical engagement tool were produced. As the mechanical engagement tool, a pair of hook-and-loop fasteners having a shear shear force of 0.8 kg / cm ² and a peel strength of 400 g / cm was used.

  For comparison, a conventional tire in which a side reinforcing layer made of a rubber composition was integrally formed inside each sidewall portion was prepared. Further, a load support body extending along the tire circumferential direction was arranged inside each sidewall portion, and a tire of a comparative example in which the load support body was fixed to the inner surface of the sidewall portion with an adhesive was manufactured. .

  About these test tires, riding comfort and run-flat running distance were evaluated by the following evaluation methods, and the results are shown in Table 1.

Ride comfort:
Each test tire was assembled on a wheel with a rim size of 18 × 8 J and mounted on a test vehicle, the air pressure was set to 230 kPa, the test course consisting of an asphalt road surface was run at an average speed of 80 km / h, and the sensory evaluation was performed by the driver. The evaluation results are indicated by an index with the conventional example being 100. The larger the index value, the better the riding comfort.

Run-flat mileage:
Each test tire is assembled to a wheel with a rim size of 18 × 8J and mounted on the test vehicle. The valve core of the right drive wheel is removed while the air pressure of the other tire is 230 kPa, and the test course consisting of asphalt road surface has an average speed of 80 km / h. The vehicle was run until the tire failed and the vehicle became unable to run, or the driver felt the vibration due to the tire failure, and the running distance was measured. It means that run flat durability is excellent, so that this mileage is large.

  As can be seen from Table 1, in comparison with the conventional example, the tires of Examples 1 to 7 were able to achieve good run-flat running performance and good riding comfort during normal running. On the other hand, the tire of the comparative example had insufficient run-flat running performance because the load support was fixed to the inner surface of the sidewall portion with an adhesive, and the riding comfort during normal running was poor. .

DESCRIPTION OF SYMBOLS 1 Tread part 2 Side wall part 3 Bead part 4 Carcass layer 5 Bead core 6 Belt layer 11 Load support 11a Outer wall surface 11b Inner wall surface 12 Mechanical engaging tool 13A, 13B Surface fastener 14 Protrusion 15a, 15b, 15c Divided piece 16 Curve Part 17 Bag

Claims (11)

An annular tread portion extending in the tire circumferential direction, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the inner side in the tire radial direction of the sidewall portions. In the provided pneumatic tire,
A load support extending along the tire circumferential direction is disposed inside each sidewall portion, and the load support is detachably attached to the inner surface of the sidewall portion via a mechanical engagement tool. A pneumatic tire characterized by that.   The pneumatic tire according to claim 1, wherein the mechanical engagement tool is a pair of hook-and-loop fasteners.   The pair of hook-and-loop fasteners includes a hook-side hook-and-loop fastener and a loop-side hook-and-loop fastener, the hook-side hook-and-loop fastener is vulcanized and bonded to the inner surface of the sidewall portion, and the loop-side hook-and-loop fastener is attached to the load. The pneumatic tire according to claim 2, wherein the pneumatic tire is attached to a support. The pneumatic tire according to claim 2 or 3 , wherein a shear shear force in an engaged state of the pair of hook-and-loop fasteners is 0.6 kg / cm ² or more and a peel strength is 200 g / cm or more. .   The mechanical support is disposed in a part of the surface where the load support is in contact with the inner surface of the sidewall portion during run-flat travel, and the mechanical support is not provided in other regions. The pneumatic tire according to any one of claims 1 to 4, wherein the load support is configured to be in direct contact with an inner surface of the sidewall portion.   The pneumatic tire according to claim 5, wherein a protrusion that locks an end portion of the load support during run flat traveling is provided on an inner surface of the sidewall portion.   The load support has an outer wall surface that contacts the inner surface of the sidewall portion and an inner wall surface facing the tire lumen, and the inner wall surface is a flat surface or a curved surface that is recessed outward in the tire width direction. The pneumatic tire according to any one of claims 1 to 6, characterized in that   The load support body has a plurality of divided pieces divided in the tire radial direction, and the divided pieces are in contact with each other during run-flat travel. Pneumatic tires.   The pneumatic tire according to claim 8, wherein hardness of the plurality of divided pieces constituting the load support body is different from each other.   The air according to any one of claims 1 to 9, wherein the load support body is accommodated in a bag body, and the bag body is mounted on an inner surface of the sidewall portion by the mechanical engagement tool. Enter tire.   The pneumatic tire according to any one of claims 1 to 10, wherein the load support is made of rubber or a resin having a melting point or a thermal decomposition temperature of 150 ° C or higher.

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