Pneumatic tire and method of manufacturing the same

Abstract

The present technology provides a pneumatic tire provided with a mechanical fastener member for attaching an object to the inner surface of a pneumatic tire, wherein the mechanical fastener member is bonded with high bonding strength to the inner circumferential surface of the tire, and a method of manufacturing the same. The pneumatic tire of the present technology comprises a mechanical fastener member on a tire inner surface, the mechanical fastener member corresponding to a first member of a mechanical fastener separable into two members and being fixed protruding to a tire cavity side. A fixing strength of the mechanical fastener member is from 0.1 to 100 (N/mm.sup.2).

Claims

1. A pneumatic tire comprising a detachable collar member disposed around a mechanical fastener member in a space formed between a protruding tip of the mechanical fastener member and a tire inner surface around the mechanical fastener member, the mechanical fastener member being on the tire inner surface, the mechanical fastener member corresponding to a first member of a mechanical fastener separable into two members, and the mechanical fastener member being fixed protruding to a tire cavity side; wherein the mechanical fastener member has a fixing strength of from 0.1 to 100 mm .sup.2.

2. The pneumatic tire according to claim 1, wherein a bottom portion of the mechanical fastener member is embedded in the tire inner surface, and the mechanical fastener member has a protruding height from the tire inner surface of 3 mm or greater and a maximum diameter of 8 mm or greater.

3. The pneumatic tire according to claim 2, wherein a recess is formed in the tire inner surface around the mechanical fastener member.

4. The pneumatic tire according to claim 3, wherein the mechanical fastener member comprises two or more components, the two or more components forming the mechanical fastener member by being fixed together and sandwiching a tire member or a tire reinforcing member fixed to the tire; and the mechanical fastener member is fixed to the tire member or the tire reinforcing member fixed to the tire by vulcanization bonding.

5. The pneumatic tire according to claim 4, wherein the mechanical fastener member comprises the two or more components, the two or more components forming the mechanical fastener member by being fixed together and sandwiching the tire reinforcing member fixed to the tire; and the recess is formed in the tire inner surface around the mechanical fastener member, the entire recess being positioned within an outer edge line of the tire reinforcing member when the tire inner surface is viewed in plan from vertically above the tire inner surface.

6. The pneumatic tire according to claim 5, wherein the collar member is disposed prior to vulcanization molding of the pneumatic tire, and the pneumatic tire is vulcanization molded in a state in which the collar member is disposed.

7. The pneumatic tire according to claim 5, wherein an other collar member is disposed in the space prior to vulcanization molding of the pneumatic tire and removed after the vulcanization molding of the pneumatic tire, the collar member being disposed in the space formed by the removal of the other collar member.

8. The pneumatic tire according to claim 7, wherein an object comprising a second member of the mechanical fastener that engages with the first member on the tire inner surface is fixed on the tire inner surface by engagement of the first member and the second member.

9. The pneumatic tire according to claim 1, wherein a recess is formed in the tire inner surface around the mechanical fastener member.

10. The pneumatic tire according to claim 1, wherein the mechanical fastener member comprises two or more components, the two or more components forming the mechanical fastener member by being fixed together and sandwiching a tire member or a tire reinforcing member fixed to the tire; and the mechanical fastener member is fixed to the tire member or the tire reinforcing member fixed to the tire by vulcanization bonding.

11. The pneumatic tire according to claim 1, wherein the mechanical fastener member comprises the two or more components, the two or more components forming the mechanical fastener member by being fixed together and sandwiching a tire reinforcing member fixed to the tire; and the recess is formed in the tire inner surface around the mechanical fastener member, the entire recess being positioned within an outer edge line of the tire reinforcing member when the tire inner surface is viewed in plan from vertically above the tire inner surface.

12. The pneumatic tire according to claim 1, wherein the collar member is disposed prior to vulcanization molding of the pneumatic tire, and the pneumatic tire is vulcanization molded in a state in which the collar member is disposed.

13. The pneumatic tire according to claim 1, wherein an other collar member is disposed in the space prior to vulcanization molding of the pneumatic tire and removed after the vulcanization molding of the pneumatic tire, the collar member being disposed in the space formed by the removal of the other collar member.

14. The pneumatic tire according to claim 1, wherein an object comprising a second member of the mechanical fastener that engages with the first member on the tire inner surface is fixed on the tire inner surface by engagement of the first member and the second member.

15. The pneumatic tire according to claim 14, wherein the object comprising the second member is (a) an electronic circuit comprising a sensor, (b) a balance weight, (c) a run-flat core, (d) an object on which an oxygen scavenger, a drying agent, and/or an ultraviolet light detecting color fixing agent is applied or mounted, (e) a noise absorbing member, or a combination thereof.

16. The pneumatic tire according to claim 1 used for construction vehicles having a tire external diameter of 0.8 m or greater.

17. A pneumatic tire comprising: a mechanical fastener member on a tire inner surface, the mechanical fastener member corresponding to a first member of a mechanical fastener separable into two members, and the mechanical fastener member being fixed protruding to a tire cavity side; wherein the mechanical fastener member has a fixing strength of from 0.1 to 100 N/mm.sup.2; an object comprising a second member of the mechanical fastener that engages with the first member on the tire inner surface is fixed on the tire inner surface by engagement of the first member and the second member; and the recess is formed in the tire inner surface around the mechanical fastener member, an outer edge line of the object being positioned within the outer edge line of the recess at all positions when the tire inner surface is viewed in plan from vertically above the tire inner surface.

18. A method of manufacturing a pneumatic tire that comprises a mechanical fastener member on a tire inner surface, the mechanical fastener member corresponding to a first member of a mechanical fastener separable into two members, and the mechanical fastener member being fixed protruding to a tire cavity side, the method comprising the steps of: disposing the mechanical fastener member on an inner surface of an unvulcanized green tire so as to protrude to a tire cavity side; disposing a collar member in a space formed between a region approximate to a protruding tip of a protruding portion of the mechanical fastener member and the inner surface of the green tire around the mechanical fastener member to fill the space; and vulcanization molding the green tire; the collar member being removed in the time after vulcanization molding and before the pneumatic tire comes into use.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a perspective view of a partial cross section illustrating an embodiment of the pneumatic tire of the present technology.

(2) FIG. 2 is a model diagram for explaining an example of a method of manufacturing the pneumatic tire of the present technology. FIG. 2 is also a cross-sectional view illustrating the state upon vulcanization molding of the tire using a bladder in which a collar member is disposed, upon vulcanization molding, around the mechanical fastener member to be fixed to the tire inner surface in the space formed between a protruding tip of the mechanical fastener member and the tire inner surface around the mechanical fastener member.

(3) FIG. 3 is a cross-sectional view for comparison to the example of a method of manufacturing the pneumatic tire of the present technology illustrated in FIG. 2. The cross-sectional view illustrates the state around a mechanical fastener member and the relationship of a bladder thereto in a method of manufacturing a pneumatic tire provided with a conventional mechanical fastener member.

(4) FIGS. 4A and 4B are perspective external model diagrams for explaining an exemplary form of a first member of a mechanical fastener separable into two members used in the pneumatic tire of the present technology, and for explaining how the first member is constituted by two components.

(5) FIG. 5 is an enlarged view for explaining an embodiment of the pneumatic tire of the present technology and illustrates a main portion around the mechanical fastener member provided on the tire inner surface.

(6) FIGS. 6A and 6B are enlarged views illustrating a main portion for explaining an embodiment of the pneumatic tire of the present technology, and for explaining the state in which the two components illustrated in FIGS. 4A and 4B sandwich a tire member or a tire reinforcing member and fix together to compose the first member.

(7) FIG. 7 is an enlarged view for explaining an embodiment of the pneumatic tire of the present technology and illustrates a main portion around the mechanical fastener member provided on the tire inner surface.

(8) FIGS. 8A to 8D are longitudinal cross-sectional views illustrating each example configuration of the collar member that can be used in the method of manufacturing the pneumatic tire of the present technology.

(9) FIGS. 9A and 9B are drawings illustrating each example configuration of the collar member that can be used in the method of manufacturing the pneumatic tire of the present technology. In FIGS. 9A and 9B, the top drawing is a plan view and the bottom drawing is a longitudinal cross-sectional view.

(10) FIGS. 10A and 10B are enlarged side views for explaining an embodiment of the pneumatic tire of the present technology and illustrate a main portion around the mechanical fastener member provided on the tire inner surface, in particular a configuration in which a recessed portion is formed around the mechanical fastener member.

(11) FIG. 11 is a cross-sectional view for explaining, using a model, about a preferable form of the collar member that can be used in the method of manufacturing the pneumatic tire of the present technology.

(12) FIGS. 12A and 12B are perspective views for explaining the method of measuring fixing strength of the mechanical fastener member employed in the present technology.

(13) FIGS. 13A and 13B are schematic views for explaining the method of measuring fixing strength of the mechanical fastener member employed in the present technology. A method in which a shaft shaped jig for a tensile test is engaged with the mechanical fastener member is illustrated.

(14) FIG. 14 is a schematic view for explaining the method of measuring fixing strength of the mechanical fastener member employed in the present technology. An example configuration of the shaft shaped jig for a tensile test engaged with the mechanical fastener member is illustrated using a model.

(15) FIG. 15 is a tire meridian direction cross-sectional view illustrating, using a model, the fixing position of the mechanical fastener member employed in the examples.

DETAILED DESCRIPTION

(16) A detailed explanation of the pneumatic tire of the present technology will be given below.

(17) As illustrated in FIG. 1, the pneumatic tire 1 of the present technology comprises a mechanical fastener member 3 that is a first member of a mechanical fastener separable into two members. The mechanical fastener member 3 is disposed on the tire inner surface 2 and fixed protruding to the tire cavity side. The fixing strength of the mechanical fastener member 3 is from 0.1 to 100 (N/mm.sup.2). In FIG. 1, 4 denotes a tread portion; 5 denotes a sidewall portion; and 6 denotes a bead portion.

(18) In the present technology, mechanical fastener refers to a pair of fastener members configured so that the pair of fastener members can be separated into two fastener members and can be physically re-engaged, and so that this engaging and separating can be freely repeated. This configuration may be basically similar to those of Japanese Unexamined Patent Application Publication Nos. 2012-25318A, 2012-25319A and 2012-240465A described above.

(19) Exemplary types of such a mechanical fastener are those known as hooks or snaps. Specific examples of products in the clothing industry that are generally included as mechanical fasteners are snap buttons, ring snaps, ring hooks, American snaps, American hooks, eyelet hooks, spring hooks, and jumper hooks. Such mechanical fasteners differ from surface fasteners in that while an area of the engaging part of a surface fastener is unlimited in the entire area, the area of the engaging part of a mechanical fastener is small (for example, preferably from about 1 to 115 mm.sup.2 and more preferably from about 4 to 90 mm.sup.2). In other words, mechanical fasteners are point fasteners. In other words, even when engaged at a small area of from about 1 to 115 mm.sup.2 for example, due to a mechanical male-female structure or the like, strong engaging is achieved. Thus, a conventional structure for the mechanical fastener may be used. The mechanical fastener can be formed from materials such as metals, as well as synthetic resins, hard rubbers, and the like.

(20) The advantages of using such mechanical fasteners are basically the same as that described in the explanation of the conventional art.

(21) In the present technology, the mechanical fastener member 3 may, for example, be attached approximate to the tire equator of the tire inner surface as illustrated in FIG. 1, but is not particularly limited thereto. The mechanical fastener member 3 may also be disposed on the tire inner surface approximate to the bead portion 6 or the sidewall portion 5, where centrifugal forces due to tire rotation and repeated deformation of the tire inner surface accompanying tire rolling motion have less of an impact than the impact on such a tread portion 4. The present inventors believe that a fixing strength of from 0.1 to 100 (N/mm.sup.2) is sufficient for a mechanical fastener member 3 to be applied to the majority of cases of attachment-fixing of an object to be attached in a tire cavity. A mechanical fastener member 3 with a fixing strength of less than 0.1 cannot be applied to the attachment of a heavy object. Also, a mechanical fastener member 3 with a fixing strength greater than 100 would require the portion of the tire structure where it is fixed to have localized increased rigidity. As a result of this configuration, rigidity in the circumferential direction of the tire and consequently uniformity would decrease. Alternatively, if the rigidity all around the tire was increased, manufacturing costs would increase unnecessarily. Both cases are not preferable. To further ensure the effects of the technology described above are obtained, the fixing strength is preferably in a range of 0.2 to 50 (N/mm.sup.2).

(22) The method of obtaining the main characteristic of the pneumatic tire of the present technology, in other words the mechanical fastener member 3 with a fixing strength of from 0.1 to 100 (N/mm.sup.2) described above, is not particularly limited. However, the main characteristic can be achieved by the special method of vulcanization molding the pneumatic tire described in detail below. An outline of the method is described below.

(23) Specifically, by providing the mechanical fastener member 3 on a green tire and simply performing vulcanization molding of a pneumatic tire using a bladder in a conventional manner, a high fixing strength cannot be obtained. This is considered to be due to the protruding portion of the mechanical fastener member 3 causing the actions of the bladder (pressure, temperature) to be insufficient at some portions (the portion around the base of the mechanical fastener member 3), and as a result, causing vulcanization bonding at that region is insufficient. This phenomenon is explained with reference to FIG. 3. When space X, which suppresses the actions of a bladder 8, is formed at region Y around the base of the mechanical fastener member 3, and the vulcanization molding at this region of the tire inner surface is insufficient. This causes high fixing strength to be unobtainable. In particular, when the protruding height H of the mechanical fastener member 3 is large, this phenomenon is significant. Also, the bladder may be damaged where the mechanical fastener member 3 is located, which may also lead to problems in the vulcanization molding.

(24) In light of the above, the present inventors discovered that by disposing a collar member 10 in the above-described space X, as illustrated in FIG. 2, and performing vulcanization molding, pressure and heat can be sufficiently transmitted from the bladder to the region around the base of the mechanical fastener member 3, and formation of a mechanical fastener member 3 with high fixing strength can be achieved. In FIGS. 2 and 3, 7 denotes a tire structural member or a tire reinforcing member, 8 denotes a bladder, 9 denotes an innerliner, and 10 denotes a collar member. It is important that the collar member 10 is formed from a material that can sufficiently transmit the pressure and heat from the bladder to the green tire to be vulcanization molded (details described below).

(25) The effects of the present technology are particularly significant when the bottom portion of the mechanical fastener member 3 is embedded in the tire inner surface, and the mechanical fastener member 3 has a protruding height H from the tire inner surface of 3 mm or greater and a maximum diameter D of 8 mm or greater. A mechanical fastener member 3 with a protruding height H of 3 mm or greater significantly achieves the effects of using the collar member 10. However, when the maximum diameter D is less than 8 mm, the mechanical fastener member 3 lacks the stability required to support a high protruding height. As a result, a mechanical fastener member 3 with high fixing strength tends to be difficult to obtain and is thus not preferable.

(26) In the present technology, the mechanical fastener member 3 is preferably made of two or more components 3a, 3b, as illustrated by the exemplary configurations of FIGS. 4A to 6B. Also, the two or more components 3a, 3b preferably form the mechanical fastener member 3 by being fixed together and sandwiching the tire member or the tire reinforcing member 7 fixed on the tire, and the mechanical fastener member 3 is preferably fixed to the tire member or tire reinforcing member 7 fixed to the tire by vulcanization bonding. This is because the mechanical bonding strength between the components 3a, 3b enhances the fixing strength of the mechanical fastener member 3 to the tire member or tire reinforcing member 7 fixed to the tire. The two components 3a and 3b are fixed together integrally and form the first member of the pair of mechanical fastener members 3. As illustrated in FIG. 5, the component 3a is mainly exposed on the tire inner surface 2.

(27) Here, tire reinforcing member 7 refers to a component of the tire made of rubber, resin, or the like, and specifically refers to an innerliner, a carcass, or the like. Alternatively, a rubber layer exclusively for being sandwiched between the component 3a and the component 3b of the fastener, a rubberized reinforcing fiber layer or resin layer, or a plurality of laminated layers thereof forming a reinforcing layer may be additionally provided on the tire inner surface as the tire reinforcing member 7. Such a configuration is preferable because, generally, air shutoff performance in the tire is enhanced.

(28) In the present technology, the tire inner surface 2 preferably has a recessed portion 11 formed around the mechanical fastener member 3, as illustrated in FIG. 7. In FIG. 7, 12 denotes the outer edge line of the recessed portion 11. The recessed portion 11 can be formed by using the collar member 10 and applying higher pressure to the desired region than to the surrounding area, as illustrated in FIG. 10A. As the tire inner surface is curved, when an object to be attached has a flat bottom surface, the two surfaces can interfere with each other. By forming the recessed portion 11 around the mechanical fastener member 3, this interference is effectively avoided. The recess preferably has a recess depth G of from 0.2 mm to 3 mm, as illustrated in FIG. 10B. Also, the recess preferably has a flat surface without curves to prevent interference.

(29) When the tire inner surface is viewed in plan from vertically above the tire inner surface, the entire of the recessed portion 11 is preferably located within the outer edge line of the tire reinforcing member 7 (see FIGS. 6A and 6B) so as to maintain a high fixing strength.

(30) The above-described collar member 10 used in the vulcanization molding of the pneumatic tire of the present technology is removed from the tire after the vulcanization molding is completed. In other words, the collar member is not a constituent member of the tire when the tire is in use. However, in order to physically protect a protruding tip of the mechanical fastener member and/or the entire mechanical fastener member, a removable collar member may be disposed in the space formed between the protruding tip of the mechanical fastener member and the tire inner surface around the mechanical fastener member for the distribution or storage of the tire.

(31) When a collar member is used for distribution or storage, the same collar member used for vulcanization molding of the pneumatic tire may be used, or a different collar member ideal for protection during distribution or storage may be used.

(32) To achieve a high performance pneumatic tire, the pneumatic tire of the present technology preferably comprises an object with a specific function provided with a second member of a mechanical fastener that engages with the first member 3 of a mechanical fastener located on the tire inner surface, the two fastener members engaging to fix the object to the tire inner surface.

(33) The object may be selected to correspond with desired characteristics, and the object is not particularly limited. Preferable examples of such an object include any one or a combination of (a) an electronic circuit including a sensor, (b) a balance weight, (c) a run-flat core, (d) an object on which an oxygen scavenger, a drying agent, and/or an ultraviolet light detecting color fixing agent is applied or mounted, and (e) a noise absorbing member.

(34) When the tire inner surface is viewed in plan from vertically above the tire inner surface, the object and the recess of the tire inner surface around the mechanical fastener member described above preferably have a relationship in which the outer edge line of the object is positioned within the outer edge line 12 of the recess (see FIG. 10B) at all positions. This is to prevent any interference between the attached object and the tire inner surface, even if the object is rotated about the fastener member. Here, outer edge line of the object refers to the outermost edge line of, for example, a pedestal, case, or housing if the object is housed therein and then attached. The distance between the outermost edge line of the object and the outer edge line of the recess is at a minimum preferably not less than 2 mm.

(35) The pneumatic tire of the present technology is in practice preferably a tire for construction vehicles with a tire external diameter of 0.8 m or greater. This is because, although air pressure meters are often mounted onto wheels to monitor and check air pressure in the tire cavity and the like, the wheels used therefor have a shape that is difficult to attach air pressure meters to.

(36) The method of manufacturing the pneumatic tire of the present technology, as described above, uses a collar member when setting the mechanical fastener member and vulcanization molding the tire.

(37) Specifically, the method of manufacturing comprises the steps of disposing the mechanical fastener member 3 on the inner surface of an unvulcanized green tire so as to protrude to the tire cavity side, disposing a collar member 10 in a space formed between a region approximate to the protruding tip of the protruding portion of the mechanical fastener member 3 and the inner surface of the green tire around the mechanical fastener member 3 to fill the space, and vulcanization molding the green tire. Furthermore, the collar member 10 is removed in the time after vulcanization molding and before the pneumatic tire comes into use. FIGS. 8A to 8D are model diagrams illustrating disposed collar member 10 of each configuration. FIG. 8A illustrates a configuration in which the collar member is disposed with the mechanical fastener member 3 located on the tire structural member or tire reinforcing member 7. FIG. 8B illustrates a configuration in which the mechanical fastener member 3 made of two components is formed sandwiching the tire structural member or the tire reinforcing member 7, and the innerliner 9 is also vulcanization bonded. FIG. 8C illustrates a configuration in which the collar member 10 covers the apex of the mechanical fastener member 3 of the configuration illustrated in FIG. 8B. FIG. 8D illustrates a configuration in which the collar member 10 is used formed integrally with the second member 13 of the mechanical fastener that engages with the first member 3 of the mechanical fastener on the tire inner surface side. The configurations of FIGS. 8C and 8D have advantages such as of stopping foreign material from entering the engaging recessed portion of the mechanical fastener member 3.

(38) The collar member 10 preferably has a low conical shape with gentle slopes that taper to the center (apex) of the mechanical fastener member 3. The collar member 10 illustrated is FIG. 8A preferably has an angle of inclination of about from 3 to 20 degrees, but is not particularly limited thereto. Note that the angle of inclination of the collar member 10 is an angle obtained at a relatively central position that does not include the shape of the tip, as illustrated in FIG. 11. In order to transmit the pressure of the bladder to the tire, the material of the collar member 10 is preferably made of metal, synthetic resin, laminated release paper, or the like. From the perspective of handleability including ease of removal, the present inventors believe that material made of fluororesin (for example, Teflon (registered trademark)) is preferable. Also, the material preferably has a thermal conductivity of from 0.1 to 300 W/mK to ensure heat from the bladder transmits to the tire.

(39) The mechanical fastener member 3 preferably has the base portion thereof embedded in the tire inner surface, as illustrated in FIG. 2, FIGS. 10A and 10B, and the like. This configuration is preferable because an increased fixing strength can be obtained by vulcanization bonding, and durability is dramatically increased. The protruding height H of the mechanical fastener member 3 from the tire inner surface is preferably from 3 mm to 15 mm, as described above, and the maximum diameter D is preferably 8 mm or greater. This preferable configuration allows the effects of the technology to be significant.

(40) FIGS. 9A and 9B are plan views for explaining each configuration of the collar member 10 which can be used in the method of manufacturing the pneumatic tire of the present technology. In FIGS. 9A and 9B, the top drawing is a plan view and the bottom drawing is a longitudinal cross-sectional view. In a plan view, FIG. 9A is a view illustrating the circular collar member and FIG. 9B is a view illustrating a rounded-square collar member. Also, a collar member with shape such as a regular polygon may be used.

EXAMPLES

(41) Below, the pneumatic tire and the method of manufacturing a pneumatic tire of the present technology based on working examples are explained.

(42) Note that in the present technology, the fixing strength of the mechanical fastener member is measured by the following method.

(43) (a) Method of Measuring the Fixing Strength of the Mechanical Fastener Member

(44) A green tire in which the mechanical fastener member 3 is disposed is vulcanized to manufacture a tire according to the present technology. Then, a portion of the tire around the mechanical fastener member 3 is cut out, which is a test sample S (see FIG. 12A). A pair of holes 14 (see FIG. 13A) is opened in the mechanical fastener member 3 in the test sample and a rod shaped piercing jig 15 is passed through the pair of holes 14. A shaft shaped jig for a tensile test 16 is attached to the test sample via the piercing jig 15 (see FIG. 13B). The shaft shaped jig for a tensile test 16 has the configuration illustrated in the model diagram of FIG. 14 and includes the pair of holes 14 located approximate to the cylindrical end portion of the shaft shaped jig for a tensile test 16.

(45) When pulling out of the mechanical fastener member 3 via the shaft shaped jig for a tensile test 16 is performed, a fixing board 17 is disposed on the tire inner surface 2 around the mechanical fastener member 3, as illustrated in FIG. 12B, and the strength at break is obtained when the mechanical fastener member 3 is pulled out in the vertical direction in respect to the fixing board 17. The pulling speed is 50050 mm/min.

(46) Note that the fixing board 17 thus used has a hole with a diameter DE of from 1.30 to 1.35 times the diameter d of the protruding portion of the mechanical fastener 3. When pulling out of the mechanical fastener member 3 described above is performed, the fixing board 17 is firmly fixed so as to not rise. In such a manner, the shaft shaped jig for a tensile test 16 is pulled vertically, and the tensile force at the time the mechanical fastener member 3 separates from the tire structure is taken as the strength at break.

(47) The obtained value of the strength at break is divided by the maximum cross-sectional area of the mechanical fastener member 3 (component 3a or 3b) to give the value per unit cross-sectional area (N/mm.sup.2). The same test is performed on three test samples, with the average value taken as the fixing strength (N/mm.sup.2).

(48) Note that the method of measuring described above is merely a detailed example of a method of measuring. As long as the above-described tensile testing method is used as a base, the method may be made more suitable by changing the shape of the mechanical fastener and the like.

(49) Working Examples 1 to 3 and Comparative Examples 1 and 2

(50) Using a mechanical fastener member with a configuration illustrated in FIG. 8A or 8B, one mechanical fastener member 3 was disposed on the equator portion of the inner circumferential surface of the tread portion of each pneumatic tire for construction vehicles, as illustrated in the model diagram of FIG. 15, and vulcanization bonded by vulcanization molding of the tires.

(51) In Working Examples 1 to 3, a collar member (made of fluororesin (Teflon)) having the configuration illustrated in FIG. 9A was used. In Comparative Examples 1 and 2, no collar member was used, and the other components were vulcanization bonded in the vulcanization molding of the tires in a manner similar to that of Working Examples.

(52) The protruding height H (mm) from the tire inner surface and maximum diameter D (mm) of the mechanical fastener member of each test tire is shown in Table 1.

(53) The results of the measurement of the fixing strength of the mechanical fastener member for each obtained test tire is also shown in Table 1.

(54) TABLE-US-00001 TABLE 1 Comparative Comparative Working Working Working Example 1 Example 2 Example 1 Example 2 Example 3 Mechanical FIG. 8A FIG. 8A FIG. 8A FIG. 8A FIG. 8B fastener member Reinforcing No No No No Yes member used? Collar member No No Yes Yes Yes used? Protruding height 2.5 5.0 5.0 5.0 5.0 H of mechanical fastener member (mm) Maximum 5.0 8.5 8.5 14.0 14.0 diameter D of mechanical fastener member (mm) Fixing strength of 0.07 0.08 0.16 0.22 2.8 mechanical fastener member (N/mm.sup.2)

(55) The present inventors believe that a fixing strength of 0.1 N/mm.sup.2 or greater is sufficient for application to the majority of cases of attachment-fixing of an object to be attached in the tire cavity, and furthermore that a fixing strength of 0.2 N/mm.sup.2 or greater is sufficient for application to almost all cases of attachment-fixing of an object to be attached in the tire cavity.

(56) As can be seen from the results shown in Table 1, the pneumatic tires according to the present technology having such a fixing strength are superior tires.