JP5657975B2 - Rehabilitation tire manufacturing method - Google Patents

Description

  The present invention relates to a retread tire manufacturing method, and more particularly to an aircraft retread tire manufacturing method used for aircraft.

  An increase in the temperature of the tire is not preferable from the viewpoint of durability because it promotes a change over time such as a change in physical properties of the material or causes damage to the tread when traveling at high speed. In particular, durability is improved for aircraft tires, off-the-road radial (ORR) tires, truck bus radial (TBR) tires that are used under heavy loads, and run-flat tires during puncture travel (running at an internal pressure of 0 kPa). Therefore, reducing the tire temperature is a major issue.

  As a technique for promoting the heat radiation of a tire, Patent Document 1 describes a tire having a turbulent flow generation uneven portion including a groove portion and a protrusion portion on at least a part of a tire side. According to this tire, the turbulent flow can be generated by the turbulent flow generating uneven portion, and the heat radiation of the tire side can be promoted.

  Moreover, tires generally used in aircraft may be rehabilitated in consideration of economy. Specifically, the tread portion of the used aircraft tire returned from the market run is subjected to buffing (shaving) processing, and the pre-formed tread portion is attached to form a regenerated green tire. And the retreaded tire is completed by being vulcanized using a mold (hereinafter referred to as a retreading mold) covering the entire retreaded green tire.

International Publication No. 2007/032405

  However, when manufacturing a retreaded tire, vulcanization pressure is applied to the retreaded green tire in the retreading mold, so in a conventional tire having a turbulent flow generating uneven part, the tire side turbulent generating uneven part has There is a risk of deformation or crushed by the vulcanization pressure.

  The present invention has been made in view of such a situation, and a retreaded green tire having a turbulent flow generating uneven portion on a tire side is rehabilitated while suppressing deformation of the turbulent flow generating uneven portion. It aims at providing the retreaded tire manufacturing method to manufacture.

In order to solve the above problems, a method for manufacturing a retread tire according to an exemplary aspect of the present invention has a turbulent flow generation uneven portion including a groove portion and a protrusion on at least a part of a tire side, and The relationship of 1.0 ≦ Pa / Ha ≦ 50.0 and 1.0 ≦ (Pa−Wa) /Wa≦100.0, where Ha is the height of the protrusion, Pa is the pitch, and Wa is the width. A retreaded tire manufacturing method for manufacturing a retreaded tire using a retreading mold having a recess into which the protrusion is inserted, wherein the depth of the dent in the mold for retreading is satisfied. Including a vulcanization step using the mold for rehabilitation satisfying the relationship of Hb ≧ 1.3Ha, Wb ≧ 1.3Wa, and Pb = Pa when the thickness is Hb, the pitch is Pb, and the width is Wb. Features.

  By using a mold for rehabilitation having such characteristics and vulcanizing by matching the positions of the recesses of the rehabilitation mold and the protrusions of the rehabilitation green tire, this protrusion can be obtained without crushing the protrusion of the rehabilitation green tire. A retread tire comprising the following can be manufactured.

  Specifically, since the depth of the dent is 1.3 times or more the height of the protrusion, it is possible to suppress the protrusion from being crushed by pressure during vulcanization. Moreover, since the width | variety of a dent part is 1.3 times or more of the width | variety of a protrusion, it can suppress that the edge part of a protrusion deform | transforms and becomes round by the pressure at the time of vulcanization | cure. For example, when the edge portion of the protrusion is deformed and rounded, it becomes impossible to generate a turbulent flow effective for the tire side flow during tire rotation. However, it is possible to generate turbulence even in the retreaded tire by suppressing the edge portion of the protrusion from being deformed and rounded. Furthermore, the pitch of the dents is configured to be the same as the pitch of the protrusions. Therefore, it becomes possible to match the position of the recess of the rehabilitation mold with the protrusion of the rehabilitation green tire.

  Incidentally, the retread tire obtained by such a manufacturing method has a turbulent flow generating uneven portion formed by a groove and a protrusion on at least a part of the tire side, and thus generated in the turbulent flow generating uneven portion. The heat dissipation on the tire side can be promoted by the turbulent flow. Since the rubber that makes up tires is a material with poor thermal conductivity, the effect of heat dissipation by accelerating the generation of turbulent flow and directly hitting the tire side rather than expanding the heat dissipation area and promoting heat dissipation large.

  ADVANTAGE OF THE INVENTION According to this invention, the retreaded green tire which has the uneven | corrugated part for turbulent flow generation on the tire side can be renovated, suppressing the deformation | transformation of the uneven | corrugated part for turbulent flow generation, and a retreaded tire can be manufactured. Moreover, since the manufactured retread tire has the uneven part for turbulent flow generation on the tire side, it can exhibit a heat dissipation effect due to the turbulent flow during tire rotation.

1 is a side view of an aircraft tire according to the present embodiment. It is a principal part perspective view of the uneven | corrugated part for turbulent flow generation | occurrence | production of the aircraft tire shown in FIG. It is sectional drawing of the uneven | corrugated part for turbulent flow generation shown in FIG. It is a principal part perspective view of the recessed part of the mold for rehabilitation. It is sectional drawing of the uneven | corrugated part for turbulent flow generation | occurrence | production of a rehabilitation green tire, and the recessed part of the mold for rehabilitation.

  Next, the retreaded tire manufacturing method according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Configuration of aircraft tires)
First, the configuration of the aircraft tire according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a cross-sectional view in the tread width direction showing an aircraft tire according to the present embodiment. FIG. 2 is a perspective view of a main part of the turbulent flow generating uneven portion 5 of the aircraft tire shown in FIG. 3 is a cross-sectional view of the turbulent flow generation uneven portion 5 shown in FIG.

  Aircraft tires are pre-molded with new aircraft tires when new, aircraft used tires returned from running on the market, and treads of used aircraft tires. The retreaded green tire to which the tread portion is attached and the retreaded tire for aircraft manufactured by vulcanizing the retreaded green tire with a mold for retreading are included.

  In the following, this aircraft tire is referred to as “aircraft tire 1”, the new aircraft tire is referred to as “new tire 1A”, the aircraft used tire is referred to as “used tire 1B”, and the regenerated green tire is referred to as “regenerated green tire”. 1C ", and the aircraft retreaded tire is referred to as" retreaded tire 1D ".

  The aircraft tire 1 includes a tread portion 2 that comes into contact with a road surface, tire side 3 on both sides of the tire, and a bead portion 4 provided along an opening edge of each tire side 3. A plurality of turbulent flow generating irregularities 5 are intermittently provided on the tire side 3 along the tire circumferential direction. In addition, as the range (processing range) of the tire side 3 forming the uneven portion 5 for generating turbulent flow, 10 to 90% of the cross-sectional height from the base line of the rim (not shown) to the outer end of the tread portion. It is a range.

  The turbulent flow generation uneven portion 5 formed on the tire side includes a plurality of protrusions 12 arranged on the outer surface of the tire side 3 so as to extend along substantially the same direction as the tire radial direction trd. The groove part 13 between the parts 12 is provided. The protrusions 12 are set to a predetermined pitch Pa, and the height Ha of the protrusions 12 is also set to the same height between the adjacent protrusions 12 in the tire circumferential direction. As shown in FIG. 3, the pitch Pa is a distance between points obtained by dividing the width at the center in the extending direction of the protrusion 12 into two equal parts.

  As described above, the uneven portion 5 for generating turbulent flow is provided intermittently along the tire circumferential direction tcd of the tire side 3. Here, there is a relationship of 1.0 ≦ Pa / Ha ≦ 50.0 between the height Ha, the pitch Pa, and the width Wa of the protrusions 12 of the turbulent flow generation uneven portion 5 and 1.0 ≦ It is set so as to satisfy the relationship Pa−Wa / Wa ≦ 100.0.

  In the present embodiment, the turbulent flow generation uneven portion 5 is provided on the tire side 3 where deterioration is likely to occur compared to other portions, so that the turbulent flow generated in the turbulent flow uneven portion 5 Heat dissipation of the tire side 3 can be promoted. Since the rubber that makes up tires is a material with poor thermal conductivity, the effect of heat dissipation by accelerating the generation of turbulent flow and directly hitting the tire side rather than expanding the heat dissipation area and promoting heat dissipation large.

  Also, if the air flow (turbulent flow) is too finely divided, that is, if the pitch Pa is narrowed, the air flow does not enter the bottom of the groove, and if the pitch Pa is too wide, the shape of the uneven portion for generating turbulent flow Since it becomes equivalent to the case where there is no processing, it is preferable to set the above numerical range.

  Further, (Pa−Wa) / Wa indicates the ratio of the width Wa of the protrusion to the pitch Pa, and if this is too small, the surface area of the protrusion 12 with respect to the area (groove 13) of the surface on which heat dissipation is desired to be improved. It is the same as that the ratio of becomes equal. Since the protrusion 12 is made of rubber and cannot be expected to improve heat dissipation due to an increase in surface area, the minimum value of (Pa−Wa) / Wa is defined as 1.0.

  Specifically, as shown in FIG. 3, with the rotation of the aircraft tire 1, the air flow S <b> 1 that has been in contact with the tire side 3 on which the turbulent flow generation uneven portion 5 is not formed It peels from the side 3 and gets over the protrusion 12. At this time, a portion (region) S <b> 2 in which the air flow stays is generated on the back side of the protrusion 12. Then, the air flow S <b> 1 reattaches to the bottom between the next protrusion 12 and is peeled off again at the next protrusion 12. At this time, a portion (region) S3 in which the air flow stays is generated between the air flow S1 and the separation at the next protrusion 12 again. Here, it is considered that increasing the velocity gradient (velocity) on the region in contact with the turbulent flow S1 is advantageous for increasing the heat dissipation rate.

(Structure of rehabilitation mold)
Next, the structure of the mold for retreading which manufactures the retreaded tire 1D mentioned above is demonstrated, referring FIG.4 and FIG.5. FIG. 4 is a perspective view of the main part of the recess 21 of the rehabilitation mold 10 according to the present embodiment, and FIG. 5 shows the recess 5 of the rehabilitation green tire and the recess 21 of the rehabilitation mold 10. FIG.

  The rehabilitation mold 10 (mold) is used when rehabilitating (molding) the rehabilitated green tire 1C into the rehabilitated tire 1D. Specifically, first, the tread portion of the used tire 1B returned from the market run is subjected to a buffing (shaving) process, and a pre-formed tread portion is pasted on the used tire 1B to manufacture a retreaded green tire 1C. To do. Next, retreaded tire 1D is manufactured by vulcanizing retreaded green tire 1C with mold 10 for retreading.

  FIG. 4 is a partial perspective view of the rehabilitation mold 10 and shows a portion corresponding to the turbulent flow generation uneven portion 5. The rehabilitation mold 10 is formed with a plurality of engaging portions 20 that engage with the turbulent flow generating uneven portion 5.

  The engaging portions 20 are arranged so as to extend along substantially the same direction as the tire radial direction trd, and a plurality of recessed portions 21 into which the protruding portions 12 of the turbulent flow generating uneven portion 5 are inserted, and these recessed portions. And a protrusion 22 between the portions 21. The recesses 21 are set to a predetermined pitch Pb, and the depth Hb of the recesses 21 is also set to the same depth in the tire circumferential direction. As shown in FIG. 5, the pitch Pb is a distance between points obtained by dividing the width at the center in the extending direction of the recessed portion 21 into two equal parts.

Here, when the recess 21 of the rehabilitation mold 10 is related to the turbulent flow unevenness 5, the depth of the recess 21 of the rehabilitation mold 10 is Hb, the pitch is Pb, and the width is Wb. , Hb ≧ 1.3Ha, Wb ≧ 1.3Wa, and Pb = Pa.

  By aligning the positions of the recesses 21 of the rehabilitation mold 10 satisfying such a relationship with the protrusions 12 of the retread green tire 1C and vulcanizing the protrusions 12 without crushing the protrusions 12 of the retread green tire. A retread tire 1D having 12 can be manufactured.

  Specifically, by setting the depth Hb of the recess 21 to 1.3 times or more the height Ha of the protrusion 12, it is possible to suppress the protrusion 12 from being crushed by the pressure during vulcanization. . Moreover, the width Wb of the dent part 21 is 1.3 times or more the width Wa of the protrusion 12, thereby suppressing the edge part of the protrusion 12 from being deformed and rounded by the pressure during vulcanization. Can do. For example, when the edge portion of the protrusion 12 is deformed and rounded, an effective degree of turbulence cannot be generated during tire rotation. However, it is possible to generate turbulence even in the retreaded tire by suppressing the edge portion of the protrusion from being deformed and rounded. Further, the pitch Pb of the recesses 21 is configured to be the same interval as the pitch Pa of the protrusions 12. Therefore, the positions of the plurality of recesses 21 and the protrusions 12 can be matched.

(Rehabilitated tire manufacturing method)
Next, a retread tire manufacturing method for manufacturing the retread tire 1D described above will be described. The retreaded tire manufacturing method includes at least a (I) buffing treatment step, (II) a tread application step, and (III) a vulcanization step.

(I) Buffing treatment step First, in the buffing treatment step, the tread portion of the used tire 1B returned from the market travel is subjected to a buffing (shaving) treatment.

(II) Tread Pasting Step Next, in the tread pasting step, a pre-formed tread portion is pasted on the used tire 1B that has been subjected to the buffing process to manufacture a regenerated green tire 1C.

(III) Vulcanization Step Next, in the vulcanization step, the retreaded green tire 1C is vulcanized by a retreading mold 10 (see FIG. 4 and FIG. 5) to produce a retreaded tire 1D. Specifically, the positions of the protrusions 12 of the rehabilitation green tire 1C and the recesses 21 of the rehabilitation mold 10 are aligned and vulcanized.

(Action / Effect)
According to the retreaded tire manufacturing method according to the present embodiment described above, it is possible to manufacture a retreaded tire including the protruding portion 12 without crushing the protruding portion 12 of the retreaded green tire 1C. Therefore, also in the manufactured retreaded tire, the turbulent flow can be generated by the turbulent flow generating uneven portion 5 formed on the tire side 3, and the heat radiation of the tire side 3 can be promoted.

  Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention.

  Specifically, in the aircraft tire 1 according to the present embodiment, the turbulent flow generation uneven portion 5 is intermittently provided along the tire circumferential direction, but is not limited to this configuration, and the entire circumference of the tire side 3 The uneven | corrugated | grooved part 5 for turbulent flow generation may be provided over.

  Further, the shape of the turbulent flow generation uneven portion 5 is not limited to the shape according to the embodiment. For example, in the embodiment, the shape of the protrusions of the turbulent flow generation uneven part 5 is the same, but the protrusions have different shapes such as a plurality of protrusions having different heights. You may comprise. Furthermore, the cross-sectional shape of the protrusion is not limited to a substantially rectangular shape, and may be a trapezoid.

  From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  DESCRIPTION OF SYMBOLS 1 ... Run flat tire, 2 ... Tread part, 3 ... Tire side, 5 ... Uneven part for turbulent flow generation, 12 ... Projection part, 13 ... Groove part, 20 ... Engagement part, 21 ... Depression part, 22 ... Protrusion part

Claims (1)

When at least a portion of the tire side has an uneven portion for generating turbulent flow composed of a groove and a protrusion, and the height of the protrusion is Ha, the pitch is Pa, and the width is Wa, 1.0 ≦ Rehabilitation green tire satisfying the relationship of Pa / Ha ≦ 50.0 and 1.0 ≦ (Pa−Wa) /Wa≦100.0 is used for the rehabilitation mold provided with the recessed portion into which the protrusion is inserted. A retread tire manufacturing method for manufacturing a retread tire,
When the depth of the recessed portion of the mold for rehabilitation is Hb, the pitch is Pb, and the width is Wb,
The retreaded tire manufacturing method characterized by including the vulcanization | cure process using the said mold for retreading satisfy | filling the relationship of Hb > = 1.3Ha, Wb > = 1.3Wa, and Pb = Pa.

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