JP6269156B2 - Rehabilitation tire - Google Patents

Description

  The present invention relates to a retreaded tire, and more particularly to a retreaded tire that can improve the torque crack resistance performance of the tire.

  Rehabilitated tires are tires that are reused by replacing the tread rubber of tires whose remaining grooves have reached the end of their lives, and are used, for example, for heavy duty tires such as trucks and buses. As such a conventional retread tire, a technique described in Patent Document 1 is known.

Japanese Patent Laid-Open No. 5-96911

  By the way, in the heavy duty tire, there is a problem that should prevent the occurrence of torque cracks in the buttress portion. Torque cracks are particularly caused by repeated deformation caused by stopping and starting (stop and go) of the vehicle and changes in physical properties caused by ozone.

  An object of this invention is to provide the retreaded tire which can improve the torque crack-proof performance of a tire.

In order to achieve the above object, a retread tire according to the present invention is a retread tire comprising a tread and a base tire, and the tread has a plurality of circumferential main grooves extending in the tire circumferential direction on the tread surface. And a tire radial distance A and a distance A in the tire radial direction to a measurement point P of the rim diameter on the basis of the groove bottom of the circumferential main groove closest to the tire equatorial plane among the plurality of circumferential main grooves. The distance B in the tire radial direction to the radially inner end has a relationship of 0.20 ≦ B / A ≦ 0.30.
The pneumatic tire according to the present invention is a retread tire including a tread and a base tire, and the tread has a plurality of circumferential main grooves extending in a tire circumferential direction on a tread surface, and a tire meridian Tires up to a measurement point P of the rim diameter with respect to the intersection point X when taking the intersection point X of the reference line connecting the groove bottoms of the plurality of circumferential main grooves and the tire equatorial plane in a sectional view in the direction The distance A in the radial direction and the distance B in the tire radial direction to the inner end in the tire radial direction of the tread have a relationship of B / A ≦ 0.30, and the end of the tread on the inner side in the tire radial direction The distance C between the portion and the end portion in the tire radial direction of the residual tread in the base tire is in the range of 10 [mm] ≦ C.

  In the retreaded tire according to the present invention, the ratio B / A is optimized, and the distance between the inner end of the tread in the tire radial direction and the tire maximum width position is appropriately secured. Thereby, there is an advantage that the influence of repeated deformation of the sidewall portion at the time of stopping and starting of the vehicle is reduced, and the occurrence of torque cracks is suppressed.

FIG. 1 is a cross-sectional view in the tire meridian direction showing a retread tire according to an embodiment of the present invention. FIG. 2 is an enlarged view showing the retread tire described in FIG. 1. The figure has shown the enlarged view of the buttress part of the retreaded tire. FIG. 3 is an enlarged view showing a tread end portion of the retread tire described in FIG. 1. FIG. 4 is an explanatory view showing a modified example of the retread tire described in FIG. 3. FIG. 5 is a chart showing the results of the performance test of the retreaded tire according to the embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Rehabilitated tire]
FIG. 1 is a cross-sectional view in the tire meridian direction showing a retread tire according to an embodiment of the present invention. The same figure has shown sectional drawing of the one-side area | region of a tire radial direction.

  In the figure, the cross section in the tire meridian direction means a cross section when the tire is cut along a plane including a tire rotation axis (not shown). Reference sign CL denotes a tire equator plane, which is a plane that passes through the center point of the tire in the tire rotation axis direction and is perpendicular to the tire rotation axis. Further, the tire width direction means a direction parallel to the tire rotation axis, and the tire radial direction means a direction perpendicular to the tire rotation axis.

  The retreaded tire 10 is a tire that is reused by replacing the tread rubber of a tire whose remaining groove has reached the end of its life. For example, the retread tire 10 is used for a heavy load tire such as a truck or a bus. As shown in FIG. 1, the retread tire 10 includes a tread 20 and a base tire 30. Further, the retread tire 10 is manufactured by a remolding method or a precure method.

[Rehabilitated tire by remolding method]
In the retread tire 10 manufactured by the remolding method, the tread 20 is unvulcanized rubber at the material stage, and constitutes the tread portion of the retread tire 10 at the product stage. Further, the tread 20 can be made of, for example, a strip-shaped unvulcanized rubber, a plate-shaped unvulcanized rubber, or the like.

  The base tire 30 is formed by cutting off part of the tread rubber and part of the sidewall rubber of the tire whose remaining grooves have reached the end of life, and buffing the outer peripheral surface thereof.

  Further, the retread tire 10 includes a pair of bead cores 11 and 11, a pair of bead fillers 12 and 12, a carcass layer 13, and a plurality of belt plies 141 to 144 (in FIG. 1, a high angle). Belt 141, a pair of cross belt plies 142, 143, and belt cover 144), a tread rubber 15 constituting a tread portion, and side wall rubbers 16, 16 constituting left and right side wall portions. And rim cushion rubbers 17 and 17 constituting left and right bead portions. Among these constituent elements, the tread rubber 15 is mainly composed of a newly added tread 20, and the other constituent elements are included in the base tire 30.

  In the configuration of FIG. 1, the retread tire 10 includes a plurality of circumferential main grooves 21 and 22 that extend in the tire circumferential direction, and a plurality of land portions 31 that are partitioned by the circumferential main grooves 21 and 22. , 32 are provided on the tread surface. Further, the circumferential main grooves 21 and 22 and the land portions 31 and 32 are arranged symmetrically with respect to the tire equatorial plane CL.

  The circumferential main groove refers to a circumferential groove having a groove width of 5.0 [mm] or more and a groove depth of 10.0 [mm] or more. The groove width is measured as the maximum value of the groove width on the tread surface, and is measured excluding notches and chamfers formed in the groove openings. Further, the groove depth is measured as the maximum value from the tread surface to the groove bottom, and is measured by excluding partial uneven portions formed on the groove bottom.

  The remolded tire 10 by this remolding method is manufactured by the following process (not shown).

  First, the tread rubber of the tire whose remaining groove has reached the end of its life is cut out, and the outer peripheral surface thereof is buffed to obtain the base tire 30. This buffing process is performed in a state where an internal pressure is applied to the tire.

  Next, the tread 20 is disposed on the outer peripheral surface of the base tire 30. At this time, the tread 20 may be formed by (a) strip-shaped unvulcanized rubber being spirally wound around the outer peripheral surface of the base tire 30, or (b) a plate-shaped rubber member serving as a basis. The tread 20 may be formed by being wound around the outer peripheral surface of the base tire 30 and spirally winding a strip-like unvulcanized rubber around the outer periphery. In the case of the latter (b), the time required for the installation process of the tread 20 can be shortened compared to the case of the former (a).

  Next, a vulcanization process is performed. In this vulcanization step, the assembly of the tread 20 and the base tire 30 is filled into a tire vulcanization mold (not shown) having a tire molding die. Next, the assembly of the tread 20 and the base tire 30 is expanded radially outward by the pressurizing device, and the tread 20 is pressed against the tire molding die. Further, the assembly of the tread 20 and the base tire 30 is heated, so that the tread 20 is vulcanized and the shape of the tire molding die is transferred to the tread 20. Thereafter, the vulcanized tire is taken out from the tire vulcanization mold.

[Rehabilitated tire by precure method]
On the other hand, in the retreaded tire 10 manufactured by the precure method, the tread 20 is a tread rubber (precure tread) that has been vulcanized in the material stage, and constitutes a tread portion of the retreaded tire 10. Further, the tread 20 has a plate-like structure or an annular structure, and has a tread pattern when the retread tire 10 is new on its outer peripheral surface in advance.

  The retreaded tire 10 by this precure method is manufactured by the following processes (not shown).

  First, the tread rubber of the tire whose remaining groove has reached the end of its life is cut out, and the outer peripheral surface thereof is buffed to obtain the base tire 30. This buffing process is performed in a state where an internal pressure is applied to the tire.

  Next, cushion rubber (not shown) is affixed over the entire circumference of the outer peripheral surface of the base tire 30. The cushion rubber is a sheet-like unvulcanized rubber at the material stage. Thereafter, the tread 20 is disposed on the outer peripheral surface of the base tire 30 and bonded to the base tire 30 via cushion rubber.

  At this time, when the tread 20 has a plate-like structure, the tread 20 is wound around the base tire 30 and is fixed by temporarily fixing both ends by a fixing member (not shown). On the other hand, in the configuration in which the tread 20 has an annular structure, the tread 20 is expanded and contracted by a dedicated expansion / contraction diameter device (not shown) and is fitted to the outer periphery of the base tire 30.

  Next, a vulcanization process is performed. In this vulcanization process, the assembly of the tread 20 and the base tire 30 is housed in a vulcanization can (not shown), the air in the vulcanization can is sucked in vacuum, and then heated and pressurized. The cushion rubber is vulcanized. Thereafter, the vulcanized tire is taken out from the vulcanization can.

[Torque crack suppression structure]
In recent pneumatic tires for trucks and buses, the tire size tends to be flattened. For this reason, even in retreaded tires, the tire size is becoming flat.

  Here, according to the inventor's research, there is a problem that torque cracks are likely to occur in the buttress portion, particularly in a retread tire having a low flatness ratio. Torque cracks are particularly caused by repeated deformation caused by stopping and starting (stop and go) of the vehicle and changes in physical properties caused by ozone.

  Therefore, this retread tire 10 employs the following retread in order to suppress the occurrence of such torque cracks.

  FIG. 2 is an enlarged view showing the retread tire described in FIG. 1. The figure shows an enlarged view of the buttress portion of the retreaded tire 10.

  First, in a cross-sectional view in the tire meridian direction, a reference line that connects the groove bottoms of the plurality of circumferential main grooves 21 and 22 (broken line in FIG. 1. Generally, a configuration including three or more circumferential main grooves 21 and 22. Then, the groove bottom of each circumferential main groove is on a single arc.) And the intersection point X of the tire equatorial plane CL. Then, with reference to the intersection point X, a distance A in the tire radial direction to the measurement point P of the rim diameter and a distance B in the tire radial direction to the inner end in the tire radial direction of the tread 20 are respectively defined.

  As shown in FIG. 2, the end of the tread 20 on the inner side in the tire radial direction is an end on the outer side in the tire width direction and on the inner side in the tire radial direction of the tread 20 that extends inward in the tire radial direction along the sidewall. is there.

  The distances A and B are measured as a no-load condition while applying a specified internal pressure by mounting the tire on a specified rim.

  Here, the prescribed rim refers to “applied rim” prescribed in JATMA, “Design Rim” prescribed in TRA, or “Measuring Rim” prescribed in ETRTO. The specified internal pressure means “maximum air pressure” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The specified load means the “maximum load capacity” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “LOAD CAPACITY” defined by ETRTO. However, in JATMA, in the case of tires for passenger cars, the specified internal pressure is air pressure 180 [kPa], and the specified load is 88 [%] of the maximum load capacity.

  At this time, the distances A and B preferably have a relationship of B / A ≦ 0.30, and more preferably have a relationship of B / A ≦ 0.28. Therefore, the distance B is set to be small, and the end portion on the inner side in the tire radial direction of the tread 20 is the outer side in the tire radial direction from the end portion of the tread of the general pneumatic tire (the end portion of the residual tread 301 of the base tire 30). (See FIG. 2). In such a configuration, the distance between the tire radial inner end of the tread 20 and the tire maximum width position is appropriately secured, so that the influence of repeated deformation of the sidewall portion when the vehicle is stopped and started is reduced. . Thereby, generation | occurrence | production of a torque crack is suppressed.

  The distances A and B are preferably in the range of 0.20 ≦ B / A, and preferably in the range of 0.24 ≦ B / A. Thereby, the width | variety of the edge part of the tread 20 is ensured, and the adhesiveness of the tread 20 and the base tire 30 is ensured. Further, the appearance of the tread 20 is ensured, and an arrangement area for a side brand (not shown) attached to the tread 20 is ensured. The side brand of the retread tire 10 is attached to the buttress portion of the new tread 20.

  Further, the distance C between the tire radial inner end of the tread 20 and the tire radial inner end of the residual tread 301 in the base tire 30 is preferably in the range of 10 [mm] ≦ C. [Mm] ≦ C is more preferable. Thereby, the distance C between the tire radial inner end of the tread 20 and the tire radial inner end of the residual tread 301 in the base tire 30 is appropriately secured. The upper limit of the distance C is not particularly limited, but is limited by the relationship with the distance B described above.

  The residual tread 301 of the base tire 30 is a residual portion of the tread rubber after the tread of the tire whose remaining groove has reached the end of its life and buffed, and extends over the entire circumference of the radially outer surface of the base tire 30. Remains. An end portion of the residual tread 301 on the inner side in the tire radial direction serves as a boundary portion between the residual tread 301 and the sidewall rubber 16 on the tire side surface.

  The distance C is measured as a no-load state while applying a specified internal pressure by mounting the tire on a specified rim.

[Throttle end stop]
FIG. 3 is an enlarged view showing a tread end portion of the retread tire described in FIG. 1. FIG. 4 is an explanatory view showing a modified example of the retread tire described in FIG. 3.

  As shown in FIGS. 3 and 4, in the retread tire 10, the tread 20 has a throttle portion 40 that restricts the gauge G of the tread 20. The throttle portion 40 is formed in the tire circumferential direction along an end portion of the tread 20 on the outer side in the tire width direction and on the inner side in the tire radial direction. At this time, the throttle portion 40 may be formed in a region including the inner end portion of the tread 20 in the tire radial direction (see FIGS. 3 and 4), or the tire diameter from the inner end portion of the tread 20 in the tire radial direction. It may be formed at a position outside the direction (not shown).

  In the remolded retreaded tire 10, the throttle portion 40 functions as a tread rubber flow stopper during tire vulcanization molding. On the other hand, in the precure type retreaded tire 10, the squeezing portion 40 squeezes the gauge of the tread 20 along the end portion of the tread 20, thereby improving the adhesion between the tread 20 and the base tire 30.

  Moreover, it is preferable that the gauge G and width W (refer FIG. 3 and FIG. 4) of the tread 20 in the aperture | diaphragm | squeeze part 40 exist in the range of G <= 2.0 [mm] and 5.0 [mm] <= W. That is, the gauge G of the tread 20 in the throttle unit 40 is set to 2.0 [mm] or less in a predetermined region having a width W of 5.0 [mm] or more. Thereby, the area | region which narrowed the gauge G of the tread 20 is formed appropriately, and the function of the aperture | diaphragm | squeeze part 40 is ensured appropriately.

  The lower limit of the gauge G of the throttle unit 40 is not particularly limited, but is preferably in the range of 0.5 [mm] ≦ G. Thereby, the gauge G of the edge part of the tread 20 is ensured, and an external appearance property improves. Further, the upper limit of the width W of the throttle unit 40 is not particularly limited, but is more preferably in the range of W ≦ 20 [mm]. Thereby, the appearance is improved.

  The gauge G of the throttle unit 40 is the thickness of the tread 20 and is measured as the distance from the outer surface of the tread 20 to the buffed surface of the base tire 30 in a sectional view in the tire meridian direction.

  The width W of the throttle unit 40 is measured as the width of the outer surface of the tread 20 in a sectional view in the tire meridian direction.

  For example, in the configuration of FIGS. 3 and 4, the throttle portion 40 is formed in a region including the end portion of the tread 20 on the inner side in the tire radial direction. For this reason, the gauge G of the tread 20 is set in the range of G ≦ 2.0 [mm] in the region of the width W (5.0 [mm] ≦ W) from the end portion in the tire radial direction of the tread 20. ing.

  Further, in the configuration of FIG. 3, the throttle portion 40 includes a concave portion 201 formed on the outer surface of the tread 20. Specifically, the tread 20 has a recess 201 that extends in the tire circumferential direction along an end of the tread 20 on the inner side in the tire radial direction. Further, the radius of curvature of the recess 201 is set to about 10 [mm]. And the gauge G of the tread 20 in the area | region of the width W from the edge part of the tread 20 is restrict | squeezed by a part of this recessed part 201, and it is set to the range of G <= 2.0 [mm].

  In the remolded retread tire 10, the recess 201 of the tread 20 is formed by a tire molding die (not shown) having convex portions (not shown) on the molding surface of the sidewall portion. In the precure type retreaded tire 10, the concave portion 201 is formed at the end of the tread 20 during the vulcanization molding of the tread 20 (precure tread) as a component, so that the gauge G of the tread 20 is set to G in advance. ≦ 2.0 [mm] is set.

  In the remolded retreaded tire 10, as described above, the tire molding die has a convex portion for forming the concave portion 201 of the tread 20, thereby narrowing the distance between the base tire 30 and the tire molding die. The gauge G of the tread 20 becomes thin. Thereby, the throttle part 40 is formed and the outflow of the tread rubber is suppressed. Further, the adhesion between the tread 20 and the base tire 30 is improved.

  In the precure type retreaded tire 10, the tire molding die has a convex portion for forming the concave portion 201 of the tread 20, and the gauge G of the tread 20 (precure tread) is G ≦ 2.0 [mm in advance. ], The convex part of the tire molding die presses the tread 20 against the base tire 30 in the cushion rubber vulcanization process. Thereby, the adhesiveness of the tread 20 and the base tire 30 improves.

  On the other hand, in the configuration of FIG. 4, the throttle portion 40 includes a convex portion 302 formed on the outer surface of the base tire 30. Specifically, the base tire 30 has a convex portion 302 that extends in the tire circumferential direction along the outer edge of the buffed surface of the base tire 30 in the tire width direction. And by this convex part 302, the gauge G of the tread 20 in the area | region of the width W from the edge part of the tread 20 is restrict | squeezed, and it is set to the range of G <= 2.0 [mm].

  The convex portion 302 of the base tire 30 is formed by leaving off the residual tread 301 of the base tire 30 in the buffing process of the base tire 30.

  In the remolded retread tire 10, since the base tire 30 has the convex portion 302, the distance between the base tire 30 and the tire molding die is narrowed, and the gauge G of the tread 20 becomes thin. Thereby, the throttle part 40 is formed and the outflow of the tread rubber is suppressed. Further, the adhesion between the tread 20 and the base tire 30 is improved.

  In the precure type retreaded tire 10, the base tire 30 has a convex portion 302, and the gauge G of the tread 20 (precure tread) is set in a range of G ≦ 2.0 [mm] in advance. In the cushion rubber vulcanization process, the convex portion 302 of the base tire 30 presses the tread 20 against the tire mold. Thereby, the adhesiveness of the tread 20 and the base tire 30 improves.

  3 and 4, the throttle portion 40 of the tread 20 is formed by one of the concave portion 201 (FIG. 3) of the tread 20 and the convex portion 302 (FIG. 4) of the base tire 30. However, the invention is not limited thereto, and the throttle portion 40 of the tread 20 may be formed by a combination of both the concave portion 201 of the tread 20 and the convex portion 302 of the base tire 30 (not shown).

[effect]
As described above, the retread tire 10 includes the tread 20 and the base tire 30 (see FIG. 1). Further, the tread 20 has a plurality of circumferential main grooves 21 and 22 extending in the tire circumferential direction on the tread surface. Moreover, when taking the crossing point X of the tire equatorial plane CL and the reference line connecting the groove bottoms of the plurality of circumferential main grooves 21 and 22 in a cross-sectional view in the tire meridian direction, the rim diameter based on the crossing point X The distance A in the tire radial direction to the measurement point P and the distance B in the tire radial direction to the inner end in the tire radial direction of the tread 20 have a relationship of B / A ≦ 0.30.

  In such a configuration, the ratio B / A is optimized, and the distance between the end portion on the inner side in the tire radial direction of the tread 20 and the tire maximum width position is appropriately secured. Thereby, there is an advantage that the influence of repeated deformation of the sidewall portion at the time of stopping and starting of the vehicle is reduced, and the occurrence of torque cracks is suppressed.

  Moreover, in this retreaded tire 10, distance A and B exist in the range of 0.20 <= B / A (refer FIG. 1). Thereby, there exists an advantage by which the width | variety of the edge part of the tread 20 is ensured and the adhesiveness of the tread 20 and the base tire 30 is ensured. In addition, there is an advantage that the appearance of the tread is ensured and the arrangement area of the side brand attached to the tread 20 is secured.

  Moreover, in this retreaded tire 10, the tread 20 has a throttle part 40 that is formed in the tire circumferential direction along the tire width direction outer side of the tread 20 and the tire radial direction inner side of the tread 20 and restricts the gauge G of the tread 20 ( 3 and 4). In the remolded retreaded tire 10, the position of the end portion of the tread 20 after vulcanization can be appropriately controlled by the throttle portion 40 functioning as a flow stopper for the tread rubber during tire vulcanization molding. Thereby, there exists an advantage which can suppress generation | occurrence | production of a torque crack appropriately. The precured tread type retread tire 10 has an advantage that the adhesiveness between the tread 20 and the base tire 30 is improved by the throttle portion 40 reducing the gauge of the tread 20 along the end portion of the tread 20.

  Further, in this retread tire 10, the gauge G and the width W of the tread 20 in the throttle portion 40 are in the ranges of G ≦ 2.0 [mm] and 5.0 [mm] ≦ W (see FIGS. 3 and 4). ). Thereby, there exists an advantage by which the gauge G and width | variety W of the aperture part 40 are optimized, and the function of the aperture part 40 is ensured appropriately.

  Moreover, in this retreaded tire 10, the narrowing part 40 consists of the recessed part 201 formed in the outer surface of the tread 20 (refer FIG. 3). In such a configuration, the throttle portion 40 having a predetermined gauge G and width W is formed by part or all of the recess 201. Thereby, there exists an advantage which can shape | mold the aperture part 40 appropriately.

  Moreover, in this retreaded tire 10, the throttle part 40 consists of the convex part 302 formed in the outer surface of the base tire 30 (refer FIG. 4). In such a configuration, the throttle part 40 having a predetermined gauge G and width W is formed by a part or all of the convex part 302. Thereby, there exists an advantage which can shape | mold the aperture part 40 appropriately.

  In this retreaded tire 10, the distance C between the end portion in the tire radial direction of the tread 20 and the end portion in the tire radial direction of the residual tread 301 in the base tire 30 is in the range of 10 [mm] ≦ C. Yes (see FIG. 2). Thereby, there exists an advantage by which the distance C of the edge part of the tread 20 and the edge part of the residual tread 301 is ensured appropriately. For example, if the distance C is C <10 [mm], the end of the tread 20 and the end of the residual tread 301 are close to each other and cracks are likely to occur, which is not preferable.

[Applicable to]
In particular, a retread tire having a low flatness ratio has a problem that torque cracks are likely to occur in the buttress portion. Therefore, by applying a low flat tire having a flatness ratio of 70 [%] or less, there is an advantage that the effect of improving the torque crack resistance of the tire can be remarkably obtained.

  FIG. 5 is a chart showing the results of the performance test of the retreaded tire according to the embodiment of the present invention.

  In this performance test, an evaluation regarding torque crack resistance was performed for a plurality of types of test tires. In addition, a test tire having a tire size of 275 / 70R22.5 is assembled to an applicable rim specified by JATMA, and the highest air pressure and a multi-wheel load specified by JATMA are applied to the test tire. In addition, a drum durability test was performed while irradiating the tire side surface with ozone, and the occurrence of torque cracks in the buttress portion was observed.

  The test tires of Examples 1 to 5 are retreaded tires 10 by the remolding method, and have the configurations described in FIGS. The diaphragm 40 is measured as the width W [mm] (see FIG. 2) of the region where the gauge G at the end of the tread 20 is G ≦ 2.0 [mm].

  The test tire of the conventional example is a retreaded tire by a remolding method, and has the same structure as the test tire of Example 1, but the tread 20 does not have the throttle portion 40.

  As the test results show, it can be seen that in the test tires of Examples 1 to 5, torque cracks in the buttress portion are suppressed.

  10: retread tire, 11: bead core, 12: bead filler, 13: carcass layer, 14: belt layer, 141-144: belt ply, 15: tread rubber, 16: sidewall rubber, 17: rim cushion rubber, 20: Tread, 201: concave portion, 21, 22: circumferential main groove, 30: tire, 31, 32: land portion, 301: residual tread, 302: convex portion, 40: throttle portion

Claims (8)

A retread tire comprising a tread and a base tire,
The tread has a plurality of circumferential main grooves extending in the tire circumferential direction on the tread surface, and
When a cross-sectional view in the tire meridian direction shows an intersection X between a reference line connecting the bottoms of the plurality of circumferential main grooves and the tire equator plane, up to a measurement point P of the rim diameter based on the intersection X Tire radial direction distance A and tire radial direction distance B to the inner end of the tread in the tire radial direction have a relationship of 0.20 ≦ B / A ≦ 0.30. . The retread tire according to claim 1 , wherein the tread has a throttle portion that is formed in a tire circumferential direction along an end portion in the tire width direction outer side and the tire radial direction inner side of the tread to restrict a gauge of the tread. The retreaded tire according to claim 2 , wherein a gauge G and a width W of the tread in the throttle portion are in a range of G≤2.0 [mm] and 5.0 [mm] ≤W. The rehabilitated tire according to claim 2 or 3 , wherein the narrowed portion comprises a recess formed on an outer surface of the tread. The rehabilitated tire according to any one of claims 2 to 4 , wherein the throttle portion includes a convex portion formed on an outer surface of the base tire. The tire radial direction inner end portion of the tread, the distance C between the base tire radial direction inner end portion of the residual tread in tires, claim 1-5 in the range of 10 [mm] ≦ C Rehabilitation tire as described in one. The retreaded tire according to any one of claims 1 to 6 , which has a flatness ratio of 70% or less.   A retread tire comprising a tread and a base tire,
  The tread has a plurality of circumferential main grooves extending in the tire circumferential direction on the tread surface,
  When a cross-sectional view in the tire meridian direction shows an intersection X between a reference line connecting the bottoms of the plurality of circumferential main grooves and the tire equator plane, up to a measurement point P of the rim diameter based on the intersection X The tire radial distance A and the tire radial distance B to the inner end of the tread in the tire radial direction have a relationship of B / A ≦ 0.30, and
  A rehabilitated tire, wherein a distance C between a tire radial inner end of the tread and a tire tread inner radial end of the base tire is in a range of 10 [mm] ≦ C.

Images