JP5958085B2 - Precure retread tire - Google Patents

Description

  The present invention relates to a precure retreaded tire, and more particularly to a precure retreaded tire and a precure tread that can improve tire uniformity and durability.

  Precured retreaded tires are tires that are reused by replacing the tread rubber of a tire whose remaining groove has reached the end of its life, and are used as tires for trucks and buses. Moreover, in a precure retread tire, a vulcanized precure tread having a tread pattern is used as a tread rubber for replacement. As such a conventional precure retread tire, a technique described in Patent Document 1 is known.

JP 2007-320044 A

  By the way, in a precure retread tire, in order to improve the uniformity of a tire, there exists a subject which should improve the positioning accuracy of a precure tread and a base tire, and should suppress meandering of a precure tread. There is also a problem that the remaining air between the precure tread and the cushion rubber should be reduced in order to improve the durability performance of the tire.

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a precure retreaded tire and a precure tread that can improve tire uniformity and durability performance.

In order to achieve the above object, a precure retread tire according to the present invention includes a precure tread, a base tire, and a cushion rubber for bonding the precure tread and the pedestal tire, and extends in the tire circumferential direction. A pre-cured retread tire having a plurality of circumferential main grooves and a plurality of land portions defined by the circumferential main grooves on a tread surface, wherein the pre-cured tread is on an adhesive surface with the base tire and a recess formed, possess a through hole penetrating the tread surface of the land portion from said recess, said platform tire, have a convex portion to be fitted into the recess through the cushion rubber, the pre-cured tread has a plurality of said recesses, and, wherein the depth of the recess in the tire equatorial plane side of the recess is greater than the depth of the recess in the shoulder portion To.
In addition, a precure retread tire according to the present invention includes a precure tread, a base tire, and a cushion rubber that bonds the precure tread and the base tire, and a plurality of circumferential directions extending in the tire circumferential direction. A pre-cured retread tire having a main groove and a plurality of land portions divided into the circumferential main grooves on a tread surface, wherein the precure tread is formed on a bonding surface with the base tire; A through hole penetrating from the concave portion to the tread surface of the land portion, the base tire has a convex portion that fits into the concave portion via the cushion rubber, and the precure tread has a plurality of The width of the concave portion on the tire equatorial plane side of the pair of concave portions adjacent to each other in the tire width direction is larger than the width of the concave portion on the shoulder side. And features.
In addition, a precure retread tire according to the present invention includes a precure tread, a base tire, and a cushion rubber that bonds the precure tread and the base tire, and a plurality of circumferential directions extending in the tire circumferential direction. A pre-cured retread tire having a main groove and a plurality of land portions divided into the circumferential main grooves on a tread surface, wherein the precure tread is formed on a bonding surface with the base tire; A through hole penetrating from the concave portion to the tread of the land portion, the base tire has a convex portion that fits into the concave portion via the cushion rubber, and the through hole is The cross-sectional area is narrowed from the recess toward the tread of the land.

  In the pre-cured retread tire and the pre-cured tread according to the present invention, in the assembly process of the precure tread, the base tire and the cushion rubber, the concave portion of the pre-cured tread and the convex portion of the base tire are fitted to each other while sandwiching the cushion rubber. Match. As a result, positioning of the precure tread and the base tire can be performed easily and accurately, and there is an advantage that the uniformity of the tire is improved. Also, in the vulcanization process, residual air between the concave portion of the precure tread and the convex portion of the base tire is sucked out of the tire through the through hole of the precure tread, and the residual air inside the tire is removed. Is done. Thereby, there exists an advantage which the durable performance of a tire improves.

FIG. 1 is a sectional view in the tire meridian direction showing a precure retreaded tire according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a tread portion of the precure retread tire described in FIG. 1. FIG. 3 is a plan view showing a tread portion of the precure retread tire described in FIG. 1. FIG. 4 is an explanatory view showing a concave portion of the precure tread of the precure retread tire described in FIG. 1. FIG. 5 is an explanatory view showing a convex portion of a base tire of the precure retread tire described in FIG. 1. FIG. 6 is an explanatory diagram illustrating a manufacturing process of the precure retread tire described in FIG. 1. FIG. 7 is an explanatory view showing a modified example of the precure retread tire described in FIG. 1. FIG. 8 is an explanatory view showing a modified example of the precure retread tire described in FIG. 1. FIG. 9 is an explanatory view showing a modified example of the precure retread tire described in FIG. 1. FIG. 10 is an explanatory view showing a modified example of the precure retread tire described in FIG. 1. FIG. 11 is an explanatory view showing a modified example of the precure retread tire described in FIG. 1. FIG. 12 is a table showing the results of the performance test of the precure 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.

[Precure Rehabilitation Tire]
FIG. 1 is a sectional view in the tire meridian direction showing a precure retreaded tire according to an embodiment of the present invention. In the figure, the cushion rubber 4 described later is hatched. Reference sign CL is a tire equator plane.

  The precure retread tire 1 is a tire obtained by vulcanizing and molding a precure tread 2 and a base tire 3 with a cushion rubber 4. This precure retread tire 1 is used for heavy duty tires such as trucks and buses, for example.

  The precure tread 2 is a vulcanized tread rubber and constitutes a tread portion of the precure retreaded tire 1. The precure tread 2 has a plate-like structure or an annular structure, and has a tread pattern when the precure retread tire 1 is new on its outer peripheral surface.

  The base tire 3 is a member obtained by cutting out the tread rubber of a tire whose remaining groove has reached the end of its life and buffing it.

  The cushion rubber 4 is a sheet-like unvulcanized rubber and is used for bonding the precure tread 2 and the base tire 3.

  The precure retread tire 1 includes a belt layer 14 having a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, and a pair of cross belt plies 142, 143 as general components. And tread rubber 15, left and right sidewall rubbers 16, and left and right rim cushion rubbers 17 and 17. Among these components, the tread rubber 15 is mainly composed of the precure tread 2, and the other components are included in the base tire 3.

  In the configuration of FIG. 1, the belt layer 14 is formed by laminating four belt plies 141 to 144, and is arranged so as to be wound around the outer periphery of the carcass layer 13. These belt plies 141 to 144 include, for example, a high-angle belt 141, a pair of cross belts 142 and 143, and a belt cover 144. Each belt ply 141 to 144 is formed by rolling a plurality of belt cords made of steel or organic fiber material with a coating rubber and rolling the belt cords, and a predetermined belt angle (inclination of the belt cord in the fiber direction with respect to the tire circumferential direction). Corner).

  The precure retread tire 1 includes a plurality of circumferential main grooves 21 extending in the tire circumferential direction and a plurality of land portions 22 defined by the circumferential main grooves 21 on the tread surface. For example, in the configuration of FIG. 1, the precure retreaded tire 1 includes three circumferential main grooves 21 and four rows of land portions 22. Further, the circumferential main grooves 21 and the land portions 22 are arranged symmetrically with respect to the tire equatorial plane CL to form a symmetrical tread pattern. Each land portion 22 may be a rib, or may be a block row partitioned into lug grooves (not shown).

  In addition, the circumferential direction main groove means the circumferential direction groove | channel which has a groove width of 2 [mm] or more. The groove width of the circumferential main groove is measured excluding notches and chamfers formed in the groove openings.

[Precured retreaded tire manufacturing method]
In the manufacturing process (not shown) of the precure retread tire 1, the precure tread 2 and the base tire 3 are bonded via the cushion rubber 4 (see FIG. 1).

  Specifically, first, the tread rubber of the tire whose remaining groove has reached the end of its life is cut out, buffed, and the base tire 3 is acquired. Next, the cushion rubber 4 is sandwiched between the inner peripheral surface of the precure tread 2 and the outer peripheral surface of the base tire 3, and the precure tread 2 and the base tire 3 are bonded via the cushion rubber 4. Specifically, the cushion rubber 4 is affixed over the entire outer periphery of the base tire 3, and then the precure tread 2 is disposed on the outer peripheral surface of the base tire 3 and the cushion rubber 4 is interposed therebetween. The base tire 3 is bonded.

  At this time, when the precure tread 2 has a plate-like structure, the precure tread 2 is wound around the base tire 3 and is fixed by temporarily fixing both ends thereof by a fixing member (not shown). . On the other hand, in the configuration in which the precure tread 2 has an annular structure, the precure tread 2 is expanded and contracted by a dedicated expansion / contraction diameter device (not shown) and is fitted to the outer periphery of the base tire 3.

  Next, a vulcanization process is performed. In this vulcanization process, the assembly of the precure tread 2, the base tire 3 and the cushion rubber 4 is accommodated in a vulcanization can (not shown), the air in the vulcanization can is sucked in vacuum, and then heated and Pressure is applied and the cushion rubber 4 is vulcanized. Thereafter, the precure retread tire 1 (see FIG. 1) is taken out from the vulcanization can.

[Fitting structure between precure tread and base tire]
As described above, the precure retread tire 1 is configured by bonding the precure tread 2 to the base tire 3 via the cushion rubber 4. At this time, there is a request that the precure tread 2 and the base tire 3 should be accurately positioned in order to improve the tire uniformity. In particular, in a configuration in which the precure tread 2 has a plate-like structure, it is necessary to wind the precure tread 2 around the base tire 3 with high accuracy in order to suppress meandering of the precure tread 2.

  On the other hand, in the precure retreaded tire 1, the smaller the residual air between the precure tread 2 and the cushion rubber 4, the better the durability of the tire.

  Therefore, this precure retread tire 1 adopts the following configuration in order to improve the positioning accuracy between the precure tread 2 and the base tire 3 and reduce the residual air between the precure tread 2 and the cushion rubber 4. doing.

  2 and 3 are an enlarged cross-sectional view (FIG. 2) and a plan view (FIG. 3) showing the tread portion of the precure retread tire described in FIG. In these drawings, FIG. 2 shows one side region of the tread portion with the tire equatorial plane CL as a boundary. In FIG. 2, the cushion rubber 4 is hatched.

  In this precure retread tire 1, the precure tread 2 has the recessed part 23 in the adhesive surface with the base tire 3 (refer FIGS. 1-3). Further, the base tire 3 has a convex portion 31 on the adhesive surface with the precure tread 2. Moreover, the recessed part 23 of the precure tread 2 and the convex part 31 of the base tire 3 have a shape which mutually fits.

  For example, in the configuration of FIGS. 1 to 3, the precure tread 2 has two recesses 23, 23 on its inner peripheral surface. Moreover, these recessed parts 23 are arrange | positioned left-right symmetrically for the tire equator surface CL as a boundary. Moreover, each recessed part 23 is arrange | positioned in the tire width direction inner side rather than the circumferential main groove (outermost peripheral direction main groove) 22 in the outermost side of a tire width direction. Moreover, the recessed part 23 is an annular groove continuous in the tire circumferential direction, and extends over the entire circumference of the tire. Further, the base tire 3 has a pair of left and right convex portions 31, 31, and these convex portions 31, 31 are arranged at positions corresponding to the respective concave portions 23 of the precure tread 2. Moreover, the convex part 31 is an annular rib continuous in the tire circumferential direction, and extends over the entire tire circumference. Thereby, two sets of crevice 23 and convex part 31 are arranged in the tire width direction. In addition, the concave portions 23 and the convex portions 31 of each set have the same shape (arc shape in FIG. 2) so that they can be fitted to each other.

  Moreover, in this precure retread tire 1, the precure tread 2 has the through-hole 24 which penetrates from the recessed part 23 to a tread surface (refer FIGS. 1-3). Moreover, it is preferable that at least one through hole 24 is disposed in each region obtained by dividing the precure tread 2 into eight equal parts in the tire circumferential direction.

  For example, in the configuration of FIGS. 1 to 3, the through hole 24 penetrates the precure tread 2 in the thickness direction of the precure tread 2 and opens to the tread surface of the land portion 22 and the deepest portion of the recess 23. Yes. Further, a plurality of through holes 24 are provided for each recess 23, and these through holes 24 are arranged at predetermined intervals in the tire circumferential direction.

  FIG. 4 is an explanatory view showing a concave portion of the precure tread of the precure retread tire described in FIG. 1. FIG. 5 is an explanatory view showing a convex portion of a base tire of the precure retread tire described in FIG. 1. In these drawings, FIG. 4 shows the concave portion 23 and the through hole 24 of the precure tread 2 at the time of components, and FIG. 5 shows the convex portion 31 of the base tire 3 at the time of components.

  In the configuration of FIGS. 1 to 3, as shown in FIG. 4, the concave portion 23 and the through hole 24 of the precure tread 2 are arranged so as to be shifted from each other in the tire width direction with respect to the circumferential main groove 21. Yes. Specifically, when a perpendicular to the tread surface of the land portion 22 is drawn from the edge portion of the land portion 22, the recess 23 and the through hole 24 are disposed on the inner side of the land portion 22 than the perpendicular. For this reason, the through hole 24 is opened in the tread surface of the land portion 22.

  The opening width W and depth D of the recess 23 are preferably in the ranges of 3 [mm] ≦ W ≦ 25 [mm] and 1 [mm] ≦ D ≦ 5 [mm], and 5 [mm]. More preferably, they are within the ranges of ≦ W ≦ 15 [mm] and 2 [mm] ≦ D ≦ 4 [mm] (see FIG. 4). Moreover, it is preferable that the opening width W and the depth D of the recessed part 23 have a relationship of 0.1 ≦ D / W ≦ 0.8. The opening width W of the recess 23 is measured by a cross-sectional view in the tire meridian direction.

  Moreover, it is preferable that the cross-sectional area becomes narrow as the recessed part 23 goes to the tread surface from the inner peripheral surface of the precure tread 2 (refer FIG. 4). For example, in the configuration of FIG. 4, the recess 23 has an arc shape in a cross-sectional view in the tire meridian direction, so that the width is narrowed from the opening toward the bottom.

  The opening width Ri of the through-hole 24 with respect to the recess 23 is preferably in the range of 1 [mm] ≦ Ri ≦ 8 [mm], and preferably in the range of 2 [mm] ≦ Ri ≦ 4 [mm]. More preferably (see FIG. 4). Further, it is preferable that the opening width Ro of the through hole 24 with respect to the tread surface has a relationship of 0 [mm] ≦ Ri−Ro ≦ 4 [mm] with respect to the opening width Ri of the through hole 24 with respect to the recess 23. The opening widths Ri and Ro of the through holes 24 are measured in a sectional view in the tire meridian direction.

  Furthermore, it is preferable that the cross-sectional area of the through hole 24 is narrowed as it goes from the recess 23 toward the tread surface. For example, in the configuration of FIG. 4, the opening width of the through hole 24 monotonously decreases from the recess 23 toward the tread surface.

  Moreover, it is preferable that the cross-sectional area Sd of the recess 23 in the cross-sectional view in the tire meridian direction and the cross-sectional area Sp of the through hole 24 have a relationship of 0.1 ≦ Sd / Sp ≦ 1.0, and 0.3 ≦ It is more preferable to have a relationship of Sd / Sp ≦ 0.7. The cross-sectional area Sd of the recess 23 and the cross-sectional area Sp of the through hole 24 are measured in a cross-sectional view in the tire meridian direction. Further, the recess 23 and the through hole 24 are partitioned with an extended surface of the bottom surface of the recess 23 as a boundary.

  The gauge Ga (not shown) of the cushion rubber 4 is preferably in the range of 0.8 [mm] ≦ Ga ≦ 2.0 [mm]. However, the gauge Ga of the cushion rubber 4 does not have to be uniform in the tire width direction. For example, the cushion rubber 4 may have unevenness due to the cushion rubber 4 partially having a multilayer structure (not shown). ).

  Moreover, it is preferable that the recessed part 23 of the precure tread 2 and the convex part 31 of the base tire 3 have a shape which can be mutually fitted. The fitting means that the concave portion 23 and the convex portion 31 are engaged with each other via the cushion rubber 4 when the precure tread 2 and the base tire 3 are assembled with the cushion rubber 4 interposed therebetween. Thereby, the precure tread 2 and the base tire 3 can be positioned appropriately.

  For example, in the configurations of FIGS. 4 and 5, the concave portion 23 and the convex portion 31 have a similar and arcuate cross-sectional shape in a cross-sectional view in the tire meridian direction. The opening width W and depth D of the recess 23, the opening width W ′ and depth D ′ of the protrusion 31, and the gauge Ga of the cushion rubber 4 are 0 [mm] ≦ W−W′−Ga ≦. The relationship is set to 1.0 [mm] and 0 [mm] ≦ DD′−Ga ≦ 1.0 [mm].

  The opening width W, depth D and cross-sectional area Sd of the recess 23, the opening width Ri and Ro and cross-sectional area Sp of the through hole 24, and the gauge Ga of the cushion rubber 4 attach the tire to the specified rim. The specified internal pressure is applied and the load is measured as no load.

  The specified rim refers to “applied rim” defined in JATMA, “Design Rim” defined in TRA, or “Measuring Rim” defined 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.

  FIG. 6 is an explanatory diagram illustrating a manufacturing process of the precure retread tire described in FIG. 1. The figure conceptually shows the assembly process of the precure tread 2, the base tire 3, and the cushion rubber 4.

  In the manufacturing process of the precure retread tire 1, as described above, the cushion rubber 4 is sandwiched between the inner peripheral surface of the precure tread 2 and the outer peripheral surface of the base tire 3, and the precure is passed through the cushion rubber 4. The tread 2 and the base tire 3 are bonded (see FIG. 6). At this time, the concave portion 23 of the precure tread 2 and the convex portion 31 of the base tire 3 are fitted to each other via the cushion rubber 4 (see FIGS. 1 and 2). Thereby, positioning with the precure tread 2 and the base tire 3 is performed with sufficient precision.

  Further, in the vulcanization process, as described above, the assembly of the precure tread 2, the base tire 3 and the cushion rubber 4 is accommodated in the vulcanization can, and the air in the vulcanization can is sucked in vacuum (not shown). ). For this reason, residual air between the concave portion 23 of the precure tread 2 and the convex portion 31 of the base tire 3 is sucked out of the tire through the through hole 24 of the precure tread 2. Further, the cushion rubber 4 flows into the through hole 24 and closes the through hole 24 (see FIG. 2). As a result, residual air inside the tire is removed, and the through hole 24 is sealed by the cushion rubber 4 to block the water ingress path into the tire.

  7-11 is explanatory drawing which shows the modification of the precure retreaded tire described in FIG. These drawings show enlarged cross-sectional views of the main part of the precure tread 2.

  In the configuration of FIG. 1, as described above, the recess 23 of the precure tread 2 has an arc shape in a sectional view in the tire meridian direction (see FIG. 4).

  However, the present invention is not limited to this, and the recess 23 may have, for example, a triangular shape, a trapezoidal shape, an elliptical shape, a rectangular shape, or a combination thereof in a sectional view in the tire meridian direction. At this time, as shown in FIG. 7, it is preferable that the recessed part 23 has a shape which narrows a cross-sectional area as it goes to the depth direction. Furthermore, as shown in FIG. 8, it is preferable that the recessed part 23 has R shape in an opening edge part and a bottom edge part. Moreover, it is preferable that the convex part 31 of the base tire 3 also has a shape corresponding to the concave part 23 of the precure tread 2. As a result, in the assembled state of the precure tread 2 and the base tire 3, the cushion rubber 4 can be in close contact with the inner peripheral surface of the concave portion 23 and the outer peripheral surface of the convex portion 31, so that residual air inside the tire is reduced.

  Further, in the configuration of FIG. 1, the through hole 24 has a shape (Ri → Ro) whose diameter decreases from the recess 23 of the precure tread 2 toward the tread surface (see FIG. 4). At this time, the through hole 24 has a wall surface shape that is a straight line in a sectional view in the tire meridian direction.

  However, the present invention is not limited to this, and as shown in FIG. 9, when the through hole 24 has a shape whose diameter decreases from the concave portion 23 of the precure tread 2 toward the tread surface, the amount of reduction in the cross-sectional area of the through hole 24 is on the concave portion 23 side. It may be configured to be small and large on the tread surface side. As described above, the through hole 24 abruptly narrows the cross-sectional area on the tread tread surface side (the exit side of the cushion rubber 4), so that the cushion rubber 4 can block the through hole 24 without a gap in the vulcanization process.

  Further, as shown in FIG. 10, when the through hole 24 has a shape in which the diameter narrows from the concave portion 23 of the precure tread 2 toward the tread surface, the amount of reduction in the cross-sectional area of the through hole 24 greatly increases on the concave portion 23 side. You may comprise so that it may become small on the side. As described above, the through-hole 24 increases the cross-sectional area on the recess 23 side (the entrance side of the cushion rubber 4), so that the cushion rubber 4 easily flows into the through-hole 24 in the vulcanization process.

  In the configuration of FIG. 1, the through hole 24 has a circular shape in a cross-sectional view (tread plan view) perpendicular to the axial direction (see FIG. 3). Moreover, the through holes 24 and 32 adjacent to each other in the tire circumferential direction are separated from each other.

  However, the present invention is not limited to this, and the through hole 24 may have, for example, an elliptical shape in a cross-sectional view perpendicular to the axial direction, or may have a long slit shape (not shown). Further, the adjacent through holes 24 and 32 may be connected to each other through a slit or the like (not shown). Moreover, in these structures, since the opening part of the through-hole 24 has an R-shaped corner part, the residual air in this corner part is reduced.

  Moreover, in the structure of FIG. 1, as mentioned above, the recessed part 23 of the precure tread 2 is an annular groove extended in a tire circumferential direction, and makes one round in a tire circumferential direction (refer FIG. 2). Further, the convex portion 31 of the base tire 3 is an annular rib extending in the tire circumferential direction, and makes a round in the tire circumferential direction (not shown). And the recessed part 23 of the precure tread 2 and the convex part 31 of the base tire 3 are fitted in the tire perimeter. Such a configuration facilitates the processing and molding of the concave portion 23 with respect to the precure tread 2 and the processing and molding of the convex portion 31 with respect to the base tire 3, and the concave portion 23 and the convex portion when the precure tread 2 is attached to the base tire 3. 31 is preferable in that it can be easily fitted.

  However, the present invention is not limited to this, and the concave portion 23 and the convex portion 31 may have a structure divided in the tire circumferential direction (not shown). For example, a plurality of sets of concave portions 23 and convex portions 31 having a hemispherical shape or a block shape that mesh with each other may be arranged at predetermined intervals in the tire circumferential direction (not shown).

  In the configuration of FIG. 1, as described above, the precure tread 2 has two recesses 23, 23, and these recesses 23 are arranged symmetrically with respect to the tire equatorial plane CL (see FIG. 1). 1 and FIG. 3).

  However, the present invention is not limited to this, and the precure tread 2 may have a single recess 23 or may have three or more recesses 23. For example, the single recessed part 23 may be arrange | positioned on the tire equator surface CL, and the several recessed part 23 may be arrange | positioned in the predetermined position of a tire width direction (illustration omitted). At this time, it is preferable that the number of the recessed parts 23 arrange | positioned at a tire width direction is five or less. Further, in the above configuration, the base tire 3 has the convex portions 31 corresponding to the respective concave portions 23 of the precure tread 2.

  In the configuration of FIG. 1, the precure tread 2 and the base tire 3 have a pair of left and right concave portions 23 and convex portions 31.

  However, the present invention is not limited to this, and the precure tread 2 and the base tire 3 may have three or more sets of concave portions 23 and convex portions 31. At this time, as shown in FIG. 11, the depth D_ce and the width W_ce of the recess 23 on the tire equatorial plane CL side among the recesses 23 and 23 adjacent in the tire width direction, and the depth of the recess 23 on the shoulder side. D_sh and width W_ce have a relationship of D_sh ≦ D_ce and W_sh ≦ W_ce. At this time, it is preferable to have a relationship of 0.9 ≦ D_ce / D_sh and 0.9 ≦ W_ce / W_sh. That is, it is preferable that the recess 23 having a size equal to or greater than (preferably larger) is disposed on the tire equatorial plane CL side.

[effect]
As described above, the precure retread tire 1 includes the precure tread 2, the base tire 3, and the cushion rubber 4 that bonds the precure tread 2 and the base tire 3 (see FIGS. 1 and 2). The precure retread tire 1 includes a plurality of circumferential main grooves 21 extending in the tire circumferential direction and a plurality of land portions 22 defined by the circumferential main grooves 21 on the tread surface. Further, the precure tread 2 has a recess 23 formed on the adhesion surface with the base tire 3 and a through hole 24 penetrating from the recess 23 to the tread surface of the land portion 22. Further, the base tire 3 has a convex portion 31 that fits into the concave portion 23 via the cushion rubber 4.

  In this configuration, in the assembly process of the precure tread 2, the base tire 3 and the cushion rubber 4, the concave portion 23 of the precure tread 2 and the convex portion 31 of the base tire 3 are fitted together while sandwiching the cushion rubber 4. (See FIGS. 1 and 2). Thereby, since the positioning of the precure tread 2 and the base tire 3 can be performed easily and accurately, there is an advantage that the uniformity of the tire is improved. Further, in the vulcanization process, residual air between the concave portion 23 of the precure tread 2 and the convex portion 31 of the base tire 3 is sucked out of the tire through the through hole 24 of the precure tread 2, and the tire Internal residual air is removed. Further, the cushion rubber 4 flows into the through-hole 24 and closes the through-hole 24, whereby the through-hole 24 is sealed by the cushion rubber 4 and the water intrusion path into the tire is blocked (FIG. 2). reference). By these, there exists an advantage which the durable performance of a tire improves.

  Further, in the precure retread tire 1, the recess 23 of the precure tread 2 is an annular groove continuous in the tire circumferential direction (see FIG. 3), and the convex portion 31 is a rib continuous in the tire circumferential direction. In such a configuration, the concave and convex portions 23 and the convex portions 31 can be easily processed and formed, and the precure tread 2 is installed meandering with respect to the base tire 3 in the assembly process of the base tire 3 and the cushion rubber 4. There is an advantage that the situation can be effectively suppressed.

  Moreover, in this precure retread tire 1, the through-hole 24 of the precure tread 2 opens in the deepest part of the recessed part 23 (refer FIG. 4). Thereby, in the vulcanization process, there is an advantage that the residual air in the recess 23 is easily discharged through the through hole 24, and the cushion rubber 4 easily flows into the through hole 24 from the recess 23.

  Moreover, in this precure retreaded tire 1, the recessed part 23 narrows a cross-sectional area as it goes to the depth direction of the recessed part 23 (refer FIG. 4). Accordingly, there is an advantage that residual air in the recess 23 is easily discharged through the through hole 24 in the vulcanization process.

  Moreover, in this precure retreaded tire 1, the through-hole 24 narrows a cross-sectional area as it goes to the tread of the land part 22 from the recessed part 23 (refer FIG. 4). Accordingly, there is an advantage that the cushion rubber 4 appropriately closes and seals the through hole 24 in the vulcanization process.

  Moreover, in this precure retread tire 1, the opening width W and depth D of the recessed part 23 exist in the range of 3 [mm] <= W <= 25 [mm] and 1 [mm] <= D <= 5 [mm] ( (See FIG. 4). Thereby, there exists an advantage by which the opening width W and the depth D of the recessed part 23 are optimized. That is, by satisfying 3 [mm] ≦ W and 1 [mm] ≦ D, the concave portion 23 and the convex portion 31 can be easily fitted in the assembly process of the precure tread 2 and the base tire 3. Further, since W ≦ 25 [mm] and D ≦ 5 [mm], residual air in the recess 23 is easily discharged through the through hole 24 in the vulcanization step.

  Further, in this precure retread tire 1, the precure tread 2 has a plurality of recesses 23, and the depth D_ce of the recesses 23 on the tire equatorial plane CL side of the pair of recesses 23 adjacent in the tire width direction. And the depth D_sh of the recess 23 on the shoulder side has a relationship of D_sh ≦ D_ce (see FIG. 11). Thereby, there exists an advantage which can fit the recessed part 23 and the convex part 31 in the assembly process of the precure tread 2 and the base tire 3 easily.

  Further, in the precure retread tire 1, the precure tread 2 has a plurality of recesses 23, and the width W_ce of the recesses 23 on the tire equatorial plane CL side of the pair of recesses 23 adjacent in the tire width direction. The width W_sh of the recess 23 on the shoulder portion side has a relationship of W_sh ≦ W_ce (see FIG. 11). Thereby, there exists an advantage which can fit the recessed part 23 and the convex part 31 in the assembly process of the precure tread 2 and the base tire 3 easily.

  Moreover, in this precure retreaded tire 1, the opening width Ri of the through-hole 24 with respect to the recessed part 23 exists in the range of 1 [mm] <= Ri <= 8 [mm] (refer FIG. 4). Thereby, there exists an advantage by which the opening width Ri of the through-hole 24 is optimized. That is, when 1 [mm] ≦ Ri, residual air in the recess 23 is easily discharged through the through hole 24 in the vulcanization process. Further, when Ri ≦ 8 [mm], the cushion rubber 4 appropriately closes and seals the through hole 24 in the vulcanization process.

  Further, in the precure retread tire 1, the precure tread 2 has a plurality of through holes 24, and at least one through hole 24 is provided in each region obtained by dividing the precure tread 2 into eight equal parts in the tire circumferential direction. Is arranged (see FIG. 3). Thereby, there exists an advantage by which the residual air in the recessed part 23 is reduced appropriately in a vulcanization | cure process.

  In the precure retread tire 1, the cross-sectional area Sd of the recess 23 and the cross-sectional area Sp of the through-hole 24 in a cross-sectional view in the tire meridian direction have a relationship of 0.1 ≦ Sd / Sp ≦ 1.0 ( (Not shown). Thereby, there exists an advantage by which the relationship between the cross-sectional area Sd of the recessed part 23 and the cross-sectional area Sp of the through-hole 24 is optimized. That is, 0.1 ≦ Sd / Sp makes it easy for residual air in the recess 23 to be discharged through the through hole 24 in the vulcanization step. Further, when Sd / Sp ≦ 1.0, the cushion rubber 4 appropriately closes and seals the through hole 24 in the vulcanization process.

  Moreover, in this precure retreaded tire 1, the recessed part 23 and the circumferential main groove | channel 21 are arrange | positioned mutually shifted in a tire width direction (refer FIGS. 2-4). Thereby, compared with the structure (illustration omitted) in which a recessed part is arrange | positioned on the circumferential direction main groove, there exists an advantage by which the rigidity of a tread part is ensured appropriately.

  Moreover, in this precure retreaded tire 1, the gauge Ga of the cushion rubber 4 is in the range of 0.8 [mm] ≦ Ga ≦ 2.0 [mm] (not shown). Thereby, there exists an advantage by which gauge Ga of the cushion rubber 4 is optimized. That is, when 0.8 [mm] ≦ Ga, adhesion between the precure tread 2 and the base tire 3 (particularly, adhesion under the groove of the circumferential main groove 21) is appropriately ensured. Further, when Ga ≦ 2.0 [mm], the vulcanization time in the vulcanization step can be shortened.

  FIG. 12 is a table showing the results of the performance test of the precure retreaded tire according to the embodiment of the present invention.

  In this performance test, (1) durability performance and (2) uniformity were evaluated for a plurality of different pre-cured retread tires (see FIG. 12). In this performance test, a pre-cured retread tire having a tire size of 11R22.5 is assembled to an applicable rim specified by JATMA, and the highest pressure and maximum load specified by JATMA are applied to the pre-cured retread tire.

  (1) The durability performance is evaluated by a low-pressure durability test using an indoor drum tester. Then, the travel speed is increased by 1 [km / h] every 12 hours from the initial speed of 5 [km / h], and the travel time until the tire breaks down is measured. Then, based on this measurement result, index evaluation using the conventional example as a reference (100) is performed. This evaluation is preferable as the numerical value increases.

  (2) For evaluation of uniformity, tire uniformity (lateral force variation) is measured in advance according to JASO C607 “Testing method for uniformity of automobile tires”. Next, the indoor drum tester is used, and a preliminary run for 30 minutes at 150 [km / h] is performed. After that, the drum is stopped for 1 hour with the load applied. Thereafter, the tire uniformity is measured again, and the index evaluation based on the conventional example as the standard (100) is performed. This evaluation is preferable as the numerical value increases.

  The precure retread tire 1 of Examples 1-10 has the structure described in FIGS. Further, the recess 23 of the precure tread 2 is an annular groove having a circular arc shape that is continuous in the tire circumferential direction, and the convex portion 31 of the base tire 3 is an annular rib that is continuous in the circumferential direction. The through hole 24 of the precure tread 2 is a circular pin hole and has a diameter Ri of 2.0 [mm] on the tread surface side. A plurality of through holes 24 are arranged at equal intervals in the tire circumferential direction. Further, the cushion rubber 4 has a uniform gauge Ga. Moreover, the opening width W and depth D of the recessed part 23 of the precure tread 2, the opening width W 'and depth D' of the convex part 31 of the base tire 3, and the gauge Ga of the cushion rubber 4 are W-W. The relationship is set to '-Ga = 0.8 [mm] and DD'-Ga0.8 [mm].

  In the precure retread tire of Conventional Example 1, in the configuration of FIGS. 1 to 3, the precure tread 2 does not have the concave portion 23 and the through hole 24, and the base tire 3 does not have the convex portion 31. In the configuration of FIGS. 1 to 3, the precure retread tire of Conventional Example 2 has the concave portion 23 and the through hole 24, but the base tire 3 does not have the convex portion 31. Further, the cushion rubber 4 is not filled in the recess 23 and the through hole 24.

  As shown in the test results, in the precure retreaded tire 1 of Examples 1 to 10, it can be seen that the durability performance and uniformity of the tire are improved.

  DESCRIPTION OF SYMBOLS 1 Precure retread tire, 2 Precure tread, 21 Circumferential main groove, 22 Land part, 23 Recessed part, 24 Through hole, 3 tires, 31 Convex part, 4 Cushion rubber, 11 Bead core, 12 Bead filler, 13 Carcass layer, 14 belt layers, 15 tread rubber, 16 sidewall rubber, 17 rim cushion rubber, 141-144 belt ply

Claims (14)

A pre-cured tread, a base tire, and a cushion rubber that bonds the pre-cured tread and the base tire, and a plurality of circumferential main grooves extending in the tire circumferential direction, and partitioned into the circumferential main grooves It is a precure rehabilitation tire comprising a plurality of land portions formed on the tread surface,
The precured tread, possess a recess formed in the bonding surface between the base tire, and a through hole penetrating the tread surface of the land portion from the recess,
Said platform tire, have a convex portion to be fitted into the recess through the cushion rubber,
The precure tread has a plurality of the recesses, and
The precure retreaded tire characterized by the depth of the said recessed part in the tire equatorial plane side among the said recessed parts being larger than the depth of the said recessed part in the shoulder part side .   The precure retreaded tire according to claim 1, wherein the concave portion is an annular groove continuous in the tire circumferential direction, and the convex portion is a rib continuous in the tire circumferential direction.   The pre-cured retread tire according to claim 1 or 2, wherein the through hole opens at a deepest portion of the recess.   The pre-cured retread tire according to any one of claims 1 to 3, wherein the concave portion narrows a cross-sectional area as it goes in a depth direction of the concave portion.   The precure retreaded tire according to any one of claims 1 to 4, wherein the through-hole narrows a cross-sectional area as it goes from the concave portion toward the tread surface of the land portion.   The opening width W and depth D of the recess are in the range of 3 [mm] ≦ W ≦ 25 [mm] and 1 [mm] ≦ D ≦ 5 [mm]. Precure retreaded tire described in 1. The precure tread has a plurality of the recesses, and of the pair of recesses adjacent in the tire width direction, the width W_ce of the recess on the tire equatorial plane side and the width of the recess on the shoulder side. The precured retreaded tire according to any one of claims 1 to 6 , wherein W_sh has a relationship of W_sh ≦ W_ce. The precured retreaded tire according to any one of claims 1 to 7 , wherein an opening width Ri of the through hole with respect to the recess is in a range of 1 [mm] ≤ Ri ≤ 8 [mm]. The precured tread has a plurality of the through-hole, and, at least one of said through holes, said precured tread claims are arranged in each area which is divided into eight equal parts in the circumferential direction of the tire section 1-8 Precure retreaded tire as described in any one of these. Claim 1-9 having a cross-sectional area Sd of the recess in the tire meridian direction of cross section, the cross-sectional area Sp of the through holes, the relationship 0.1 ≦ Sd / Sp ≦ 1.0 Precure retreaded tire described in 1. The precure retreaded tire according to any one of claims 1 to 10 , wherein the concave portion and the circumferential main groove are disposed so as to be shifted from each other in the tire width direction. The precure retreaded tire according to any one of claims 1 to 11 , wherein a gauge Ga of the cushion rubber is in a range of 0.8 [mm]? Ga? 2.0 [mm].   A pre-cured tread, a base tire, and a cushion rubber that bonds the pre-cured tread and the base tire, and a plurality of circumferential main grooves extending in the tire circumferential direction, and partitioned into the circumferential main grooves It is a precure rehabilitation tire comprising a plurality of land portions formed on the tread surface,
  The precure tread has a recess formed in an adhesive surface with the base tire, and a through-hole penetrating from the recess to the tread surface of the land portion,
  The base tire has a convex portion that fits into the concave portion via the cushion rubber,
  The precure tread has a plurality of the recesses, and
  The pre-cured retread tire characterized in that the width of the concave portion on the tire equatorial plane side is larger than the width of the concave portion on the shoulder portion side among the pair of concave portions adjacent in the tire width direction.   A pre-cured tread, a base tire, and a cushion rubber that bonds the pre-cured tread and the base tire, and a plurality of circumferential main grooves extending in the tire circumferential direction, and partitioned into the circumferential main grooves It is a precure rehabilitation tire comprising a plurality of land portions formed on the tread surface,
  The precure tread has a recess formed in an adhesive surface with the base tire, and a through-hole penetrating from the recess to the tread surface of the land portion,
  The pedestal tire has a convex part that fits into the concave part via the cushion rubber; and
  The pre-cured retread tire, wherein the through-hole narrows the cross-sectional area from the concave portion toward the tread surface of the land portion.

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