JP2017217853A - Method for repairing tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a tire achieving cost reduction and capable of enhancing operation efficiency without need for an air bag or a device matching with a shape of a tire and a mold member matching with a pattern of a tread.SOLUTION: A mold member matching with a pattern of a tread such as an air bag or a device matching with a shape of a tire or the like is made unnecessary, cost reduction is achieved and operation efficiency is enhanced by repairing a shape of a damage part 9 of a tire 1 having damaged tread part 2 with a repair material 10 consisting of at least an unvulcanized rubber and mixing at least water and a water insoluble member with a plaster to obtain a mold material 15, filling a groove part 2b of the tread part 2 around a repair part 14 where the shape is repaired by the repair material 10 with the mold material 15 at a flow condition, curing and drying the mold material 15, then arranging a heating pad 20 on a surface of the tread part 2 of the repair part 14, compressing the repair part 14, heating the repair part 14 by the heating pad 20 and vulcanizing the unvulcanized rubber.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a method for repairing a damaged portion of a tire, and particularly to a method for repairing a tire having a damaged tread portion.

  Conventionally, in the case of tires, particularly in the case of very large tires for construction vehicles, when the tread part is damaged and the damaged part is repaired, a repair patch made of unvulcanized rubber is applied to the damaged part, or the unvulcanized part is applied to the damaged part. After the repair rubber made of rubber is packed, the repaired portion and its periphery are pressurized and vulcanized to repair.

  Since the unvulcanized rubber is in a state where the shape before crosslinking is not stable, it is necessary to maintain the shape of the restoration part when performing pressure vulcanization. In the repair method disclosed in Patent Document 1, after repairing a damaged patch by filling a repair patch, an electric heating pad is applied to the inside and the outside of the repair portion, and the tire is placed inside and outside the tire outside the electric heating pad. An air bag having a shape matching the outer shape and the inner shape is applied, and air is sent into the air bag to pressurize and vulcanize while maintaining the shape of the tire.

  In such a tire repair method, it is necessary to prepare an air bag that matches the shape of each tire to be repaired, and the cost for preparing a plurality of types of air bags increases, and many air bags are managed. It takes time and effort.

  Further, in the tire repair method disclosed in Patent Document 2, after the unvulcanized rubber is filled in the damaged portion, the repaired portion is sandwiched between the pressure pad and the backup plate of the pressure pad device. It is heated under pressure and vulcanized. The pressure pad is made of a flexible member such as silicone, and when it is pressed against the repaired part, it is deformed along the shape of the repaired part. The backup plate is made of metal, and if the restoration part has different curved surfaces such as a shoulder part or a sidewall part of the tire, it is necessary to prepare a pressure pad or a backup plate that matches the curved surface of each restoration part.

  Further, particularly when the tread portion of the tire is damaged, the shape of the land portion and the groove portion of the tread portion is repaired, and when the pressure vulcanization is performed on the repaired portion, a method for maintaining those shapes is necessary. Although not disclosed in the above-mentioned patent document, in order to maintain the shape of the land portion and groove portion of the tread during pressure vulcanization, for example, it is necessary to prepare a mold member that matches the tread pattern separately, The cost of manufacturing a mold member that matches the tread pattern for each corresponding tire and the labor of managing and repairing a large number of mold members are required, resulting in low work efficiency.

JP 50-82183 A U.S. Pat. No. 4,303,380

  Therefore, the present invention eliminates the need for an air bag or a device that matches the shape of the tire and eliminates the need for a mold member that matches the tread pattern in the tire repair method. An object of the present invention is to provide a tire repair method capable of improving the tire.

The present invention has been made to solve the above-mentioned problems, and the tire repair method of the present invention uses a repair material made of at least unvulcanized rubber to shape the damaged portion of the tire whose tread portion is damaged. Repair,
Mix at least water and water-insoluble material in calcined gypsum to obtain a mold material in a fluid state,
The groove portion of the tread portion around the repaired portion whose shape has been repaired by the repair material is filled with the mold material in a fluid state,
After the mold material is cured and dried, a heating pad is disposed on the surface of the tread portion of the restoration portion, and the restoration portion is pressurized.
The restoration portion is heated by the heating pad to vulcanize the unvulcanized rubber.

  According to the above configuration, the shape of the tire having a damaged tread portion is repaired by a repair material made of at least unvulcanized rubber, and at least water and a water-insoluble member are mixed with calcined gypsum to obtain a flowable mold material for repair. The groove part of the tread part around the repaired part repaired by the material is filled with the mold material in a fluid state, and after the mold material is cured and dried, the repaired part is pressurized and heated with a heating pad to vulcanize. At the time, it is possible to keep the tread portion of the unvulcanized rubber in the repaired portion in a desired shape without requiring an air bag or a device adapted to the shape of the tire and without preparing a mold for each shape of the tread. As a result, work efficiency can be improved and costs can be reduced. Furthermore, since the mold material that fills the groove is a mixture of calcined gypsum and at least water and a water-insoluble member, the proportion of gypsum slurry (gypsum slurry) made of calcined gypsum and water other than the water-insoluble member is insoluble in water. Since it can be lowered by the member, it is possible to shorten the time until the mold material is cured and dried, shorten the time required for repairing the tire, improve workability, and reduce the cost. be able to.

In the above configuration, the damaged part is a tire width direction end of the tread part,
The groove portion around the repair portion is filled with the mold material, and the repair portion side surface in the tire width direction side of the repair portion is covered with the mold material,
After the mold material is cured and dried, the unvulcanized rubber can be vulcanized by pressurizing and heating the restoration part.

  According to the above configuration, even when the tire width direction end portion of the tire tread portion is damaged and needs repair, the shape of the shoulder portion at the tire width direction end portion is repaired by the repair material, The groove part is filled with the mold material, and the restoration part side surface in the tire width direction of the restoration part is covered with the mold material. After the mold material is cured and dried, the restoration part can be vulcanized and heated. Even if the end in the width direction is damaged or the mold for each tire type and tread shape is not prepared, the shape of the restoration part at the end of the tread in the tire width direction is maintained and vulcanized and pressurized. This makes it possible to repair the product, improving workability and reducing costs.

  In the above-described configuration, at least one of rubber, wood, and metal can be used as the water-insoluble member.

  According to the said structure, it becomes possible by using rubber | gum and wood as a water-insoluble member, and it becomes possible to use the rubber | gum waste and cheap wood which are discarded by repair work, and can aim at cost reduction. Furthermore, by using a metal as the water-insoluble member of the mold material used in the restoration part and its surroundings, the heat conductivity from the heating pad to the restoration part and its surroundings through the mold material is increased, and it is necessary to promote vulcanization. A certain location can be effectively vulcanized.

In the above configuration, after placing a heating pad on the surface of the tread portion of the repair portion,
The stuffing member is stuffed inside the tire in the tire circumferential direction section divided in the tire circumferential direction where the restoration part exists,
Tighten and pressurize the tire circumferential direction part from the surroundings,
The unvulcanized rubber can be vulcanized by heating the repaired portion with the heating pad.

  According to the above-described configuration, the restoration portion can be pressurized from the inside of the tire by the stuffing member, so that there is no need for an air bag or a device that fits the inside of the tire, further improving work efficiency and further reducing costs. be able to.

  The present invention eliminates the need for an air bag or a device that matches the shape of the tire in the tire repair method, eliminates the need for a mold member that matches the pattern of the tread, reduces costs in tire repair, and improves work efficiency. Can be made.

1 is a perspective view of a typical tire that has been repaired by the tire repair method of the present invention. It is sectional drawing of the tire width direction of the tire of FIG. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the damaged state of the tire. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which removed the damage part of the tread side outside a ply. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which removed the damage part inside a ply. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which stuck the unvulcanized patch member from the inner side to the ply. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which filled the unvulcanized tread rubber and repaired the shape. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which poured the mold material into the restoration part and the groove part of the periphery among the groove parts of the tread part of a tire. It is explanatory drawing of the repair process of 1st Embodiment of this invention, arrange | positions an electrical heating pad in the outer side and inner side of the tire restoration part and its periphery, and stuffs a stuffing member around the tire restoration part inside a tire, It is the figure which showed the state fastened with the belt. It is the perspective view which showed the patch member used for the repair method of the 1st Embodiment of this invention. It is explanatory drawing of the repair process of the 1st Embodiment of this invention, and is the figure which showed the state which poured the mold material into the restoration part and the groove part of the periphery among the groove parts of a tread part. It is the side view which showed the lower half of the tire which showed the tire circumferential direction site | part divided into the tire circumferential direction in the area | region where the restoration part of a tire exists. FIG. 10 is a side view showing the lower half of the tire in the state of FIG. 9. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, and is the figure which showed the damage state of the tire. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, and is the figure which showed the state which removed the damage part. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, and is the figure which showed the state which filled the unvulcanized tread rubber and repaired the shape. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, and fills a restoration part and the groove part of the periphery of a groove part of a tread part with a mold material, and covers the side surface of the restoration part located in a tire width direction side surface It is the figure which showed the state which piled up the mold material in predetermined thickness in this way. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, attaches an electrothermal pad to the restoration part of a tire, and its circumference | surroundings, stuffs the filling member inside the tire around the restoration part of a tire, and tightened with the belt It is the figure which showed the state. It is explanatory drawing of the repair process of the 2nd Embodiment of this invention, The state which covered the restoration part and the groove part of the circumference | surroundings with the mold material among the groove parts of a tread part, and covered the side surface of the repaired shoulder part with the mold material FIG.

  A tire 1 shown in FIG. 1 is a typical tire subjected to the tire repair method of the present invention, and is an ultra-large radial tire such as a construction vehicle tire. A tire width direction cross-sectional view of the tire 1 is shown in FIG.

  The tire 1 includes a bead portion 5 in which a pair of left and right ring-shaped bead rings 5 a are embedded, a carcass ply 6 laid between the pair of bead portions 5 in a toroidal shape, and a circumferential contact with the radially outer side of the carcass ply 6. A belt layer 7, a tread portion 2 that is in contact with the outer peripheral surface of the belt layer 7, and a sidewall portion 4 that covers a side portion of the tire 1.

  The tread portion 2 is formed with a groove portion 2b in order to increase friction with the ground and increase traction force, and is surrounded by the groove portion 2b or surrounded by the groove portion 2b and the side edge 2c of the tread portion 2. The surface area is the land portion 2a.

  A first embodiment of a tire repair method according to the present invention will be described with reference to [Step 1] to [Step 11] and FIGS. 3 to 13. In the tire repair method of the present embodiment, the tread portion 2 as shown in FIG. 3 is cut and damaged, reaches the carcass ply 6 and the belt layer 7 inside the tire 1, and these are cut. Repair.

[Step 1]
The damaged portion 9 of the tread portion 2 is examined, and as shown in FIGS. 4 and 5, the tread rubber and the inner liner rubber around the damaged portion 9 are removed using a re-groover not shown. At this time, in order not to leave the damaged portion 9 of the tread portion 2 and the inner liner portion 8, the tread rubber and the inner rubber are carefully taken so as to leave only the carcass ply 6 radially larger than the predetermined range around the damaged portion 9. Remove the liner rubber and finish the surface.

[Step 2]
As shown in FIG. 6, a patch member 11 as a repair material 10 is attached to the inside of the exposed carcass ply 6 so as to cover the entire damaged portion 9 of the carcass ply 6. An adhesive or the like may be used when the patch member 11 is attached to the carcass ply 6. In the present embodiment, the patch member 11 is attached from the inside of the tire 1, but may be attached to both the inside and the outside depending on the degree of damage.

  As shown in FIG. 10, the patch member 11 used in the tire repair method of the present embodiment is a cross-shaped unvulcanized rubber laminate, and a reinforcement cord is provided inside. A laminated body 11A and an inner liner repair rubber part 11B attached integrally to the reinforced laminated body 11A are provided.

The reinforcing laminate 11A includes two lower laminates 11a and 11b, and two cross-shaped upper laminates 11c and 11d that are stacked on the lower laminate 11b and are smaller than the lower laminates 11a and 11b. ing. In these laminates 11a, 11b, 11c, and 11d, reinforcing cords 11a ₂ , 11b ₂ , 11c ₂ , and 11d ₂ arranged in parallel are formed by unvulcanized rubber portions 11a ₁ , 11b ₁ , 11c ₁ , 11d _1. The reinforcing cords 11a ₂ , 11b ₂ , 11c ₂ , 11d ₂ are covered and arranged so as to be perpendicular to each other when viewed from above. In this embodiment, each of the upper laminate and the lower laminate is stacked in two layers, but the number of stacked laminates may be an even number or an odd number. The number of stacked sheets may be different.

  The inner liner repair rubber portion 11B attached to the lower surface of the reinforcing laminate 11A is a sheet-like member made of unvulcanized inner liner rubber, and is formed in the same cross shape as the lowermost surface of the reinforcing laminate 11A. The patch member 11 is integrated with the reinforcing laminate 11A.

  The patch member 11 used in the present embodiment was a laminated body, but may be composed of a single layer instead of a laminated body, and the upper laminated body and the lower laminated body have different sizes, but all The laminates may have the same size, and the laminate may have a square or rectangular shape, not a cross shape.

[Step 3]
As shown in FIG. 7, the uncured tread rubber as the repair material 10 in a state of being heated and fluidized outside the carcass ply 6 (see FIG. 6) exposed by removing the tread rubber. 12 is filled with the missing part while being crushed with a spatula or the like, and the shape of the land part 2a and the groove part 2b of the missing tread part 2 is the shape before the failure of the tire 1 and is almost unused. The tire 1 is repaired to have the same shape as the tire 1. The new tread rubber 12 used for the restoration may be a tread rubber made of the same material as the tread rubber before the restoration or a tread rubber made of a different material. As described above, the shape of the damaged portion of the tire whose tread portion is damaged is repaired by the unvulcanized rubber patch member 11 and the unvulcanized tread rubber 12 as the repair material 10.

[Step 4]
When the restoration part 14 restored by the unvulcanized rubber as described above is vulcanized by pressurization and heating, a mold material 15 for maintaining the shape of the restoration part 14 is prepared. The work of preparing the mold material 15 may be performed after the above-described repair work is completed, or may be performed simultaneously with the repair work.

  The mold material 15 is obtained by mixing water with a powdered calcined gypsum as a base material to obtain a gypsum slurry (gypsum slurry), and mixing water-insoluble members such as wood, rubber scraps, and metals. Calcined gypsum is also called calcium sulfate 1/2 hydrate, and when it reacts with water, it becomes dihydrate gypsum (calcium sulfate dihydrate) and hardens.

  When the gypsum slurry is produced, the ratio of water added to the calcined gypsum is not particularly limited, and can be selected according to the required fluidity. Furthermore, various additives, such as an adhesive improvement material, can also be added as needed.

  The water-insoluble member is made of wood, rubber scrap, metal or the like, and may be powdery, granular, or larger, and may have a non-constant shape. Since the water-insoluble member is mixed in the gypsum slurry, the required ratio of the gypsum slurry in the mold material 15 can be reduced, and the time for the mold material 15 to cure and dry can be shortened.

  The larger the ratio of the water-insoluble member to the gypsum slurry, the shorter the time for the mold 15 to cure and dry, so it is necessary to vulcanize the desired time to cure and unvulcanized rubber. The strength can be appropriately changed in consideration of the strength of the mold material 15 after curing. When the water-insoluble member is a small particle such as powder or granules, the mold material 15 may be obtained by mixing the water-insoluble member with powdered calcined gypsum and then kneading with water.

[Step 5]
As shown in FIGS. 8 and 11, the mold material 15 having a fluidity before curing obtained as described above is poured so as to fill the groove 2 b around the repaired part 14 whose shape has been repaired. Is formed so as to be substantially flush with the surface of the land portion 2a.

[Step 6]
In this way, excess fluid contained in the mold material 15 is removed while allowing the fluid mold material 15 poured into the groove 2b to stand and be cured and dried. Since the mold material 15 includes a water-insoluble member, the amount of gypsum slurry in the mold material 15 poured into the same groove 2b can be reduced compared to the mold material 15 that does not include a water-insoluble member. The time until the mold material 15 is cured and dried can be shortened.

[Step 7]
Next, after the mold material 15 is cured and dried, as shown in FIG. 9, the mold material 15 is positioned so as to cover the periphery of the repair portion 14 of the tire 1, and is used as a heating pad from both the inside and the outside of the tire 1. An electric heating pad 20 is arranged. On the outer side of the tire 1, there is an electrothermal pad 20 along the outer surface of the restoration portion 14 restored by the repair material 10 of the tread portion 2 and the land portion 2 a in the vicinity thereof and the outer surface of the mold member 15 filling the groove portion 2 b. Be placed. Inside the tire 1, the electrothermal pad 20 is disposed on the restoration part 14 in which the inner liner part 8 is restored by the unvulcanized patch member 11 and the inner wall surface around the restoration part 14. In the present embodiment, the electric heating pad 20 is arranged on both the inner side and the outer side of the tire 1. However, the electric heating pad 20 may be arranged only on the inner side or the outer side depending on the state and position of the restoration part 14. .

[Step 8]
As shown in FIG. 9 and FIG. 13, the stuffing member 22 is stuffed inside the restoration portion 14 of the tire 1 and its periphery, and toward the center of the tire 1 until it exceeds the opening between the bead portions 5 of the tire 1. I will repeat. The stuffing member 22 is packed inside the tire in the tire circumferential direction portion 1a in which at least the tire having the restoration portion 14 is partitioned in the circumferential direction. The tire circumferential direction portion 1a is indicated by a dotted pattern in FIG. 12, and refers to a portion in which a portion where the repair portion 14 is present in the tire 1 is partitioned in the tire circumferential direction.

  The stuffing member 22 has a rod-like substantially cylindrical shape, and a piece of wood is used in the present embodiment, but may be made of metal, heat-resistant plastic, or the like. In the present embodiment, the cross-sectional shape of the stuffing member 22b is substantially circular. However, the cross-sectional shape of the stuffing member 22b is not limited to a circular shape. For example, the stuffing member 22b may have many shapes such as an elliptical shape, a semicircular shape, a triangular shape, and a rectangular shape. It may be a square shape or a combination of a polygon and an arc. When the electric heating pad 20 is disposed inside the repair portion 14 and the periphery thereof, the electric heating pad 20 is packed so as to be pressed by the padding member 22. The stuffing member 22 thus stuffed and raised from the opening between the bead portions 5 is covered with a plate-like pressing member 23 from above, and the electric heating pad 20 arranged outside the tire 1 is covered with the cover sheet 21 to the periphery thereof. Cover with.

[Step 9]
Thereafter, a portion of the tire 1 including at least the tire circumferential portion 1a in which the stuffing member 22 is packed is wound around the belt 24a of the fastening member 24 from the outer side of the pressing member 23 and the cover sheet 21, and repaired. The portion 14 is tightened to a predetermined pressure, and is fixed to the buckle 24b fixed to one end of the belt 24a through the other end of the belt 24a. In the present embodiment, four belts 24 a are used as the fastening member 24, but the number of belts and the width of the belts can be changed as appropriate depending on the size and position of the restoration portion 14. Further, as the tightening member 24, a wide band may be used instead of a belt.

[Step 10]
After the restoration part 14 of the tire 1 is pressurized to a predetermined pressure, an electric current is passed through the electrothermal pad 20 to generate heat. The temperature of the electric heating pad 20 is controlled to a temperature suitable for vulcanizing the unvulcanized rubber used for repairing the tire 1, and the restoration unit 14 is subjected to pressure heating for a predetermined time to be vulcanized, and the restoration unit 14 is joined to the surrounding part.

[Step 11]
In this way, after the pressure vulcanization is performed on the restoration portion 14 for a predetermined time, the fastening member 24 and the holding member 23 are removed from the tire 1, the filling member 22 is taken out from the inside of the tire 1, and the cover is covered. The sheet 21 and the electric heating pad 20 are removed from the restoration part 14. Thereafter, the mold material 15 buried in the groove 2b around the repairing part 14 is crushed and removed from the tread part 2, and the repair work of the tire 1 is completed.

  In the tire repair method according to the first embodiment of the present invention, as described above, the shape of the damaged portion 9 of the tire 1 where the tread portion 2 is damaged is changed to the tread rubber 12 as the repair material 10 made of at least unvulcanized rubber. And the patch member 11, and using the powdered calcined gypsum as a base material, at least water and a water-insoluble material are mixed into the calcined gypsum to obtain a flowable mold material 15, and the tread portion 2 around the repaired portion 14 is obtained. After filling the groove portion 2b with the mold material 15 in a fluid state and the mold material 15 is cured and dried, the electrothermal pad 20 is disposed around the repair portion 14 and the repair portion 14, and the periphery of the repair portion 14 is pressurized to be heated. Since the repaired portion 14 is heated by the pad 20 to vulcanize the unvulcanized rubber, the unvulcanized portion of the repaired portion 14 is not vulcanized without preparing a mold for each tire type and tread shape. The tread rubber 12 can be kept in a predetermined shape, improving work efficiency Cost reduction can be achieved while achieving.

  Furthermore, since the mold material 15 filling the groove 2b of the tread portion 2 is a mixture of calcined gypsum and at least water and a water-insoluble member, a gypsum slurry (gypsum slurry) made of calcined gypsum and water other than the water-insoluble member is used. Since the ratio can be lowered with a water-insoluble member, it is possible to shorten the time until the mold material 15 is cured and dried, and the work time is improved by reducing the time required for repairing the tire 1. At the same time, the cost can be reduced.

  Moreover, since at least one of rubber, wood, and metal is used as the water-insoluble member, it is possible to use rubber scraps and inexpensive wood that are discarded during repair work, thereby reducing costs. it can. Furthermore, by using a metal as the water-insoluble member of the mold material 15 used for the restoration part 14, the thermal conductivity from the electric heating pad 20 to the restoration part 14 through the mold material 15 is increased, and it is necessary to promote vulcanization. The portion can be effectively vulcanized.

  Furthermore, the electric heating pad 20 is disposed inside the tire circumferential direction portion 1a partitioned in the tire circumferential direction where the repairing portion 14 exists, and the stuffing member 22 is stuffed. The repairing portion 14 is heated by the electric heating pad 20 arranged inside the restoration portion 14 together with the electric heating pad 20 arranged outside the restoration portion 14 of the tire 1 by being tightened and pressurized by the fastening member 24, so that the restoration is performed. Since the portion 14 can be heated from the outside and the inside of the tire 1, the unvulcanized rubber of the restoration portion 14 can be sufficiently vulcanized.

  In the present embodiment, the tire 1 whose damaged portion 9 has reached the carcass ply 6 and the belt layer 7 is repaired. However, in the tire repair method of the present invention, the damaged portion does not reach the carcass ply 6 and the belt layer 7. It is also possible to repair a tire that is in a damaged state, or it is possible to repair a tire whose shape has been repaired by filling the unvulcanized tread rubber 12 without using the patch member 11 because the damaged portion is shallow.

  Next, a tire repair method according to a second embodiment will be described based on [Step 1] to [Step 10] and FIGS. 14 to 19. In the tire repair method of the present embodiment, the vicinity of the tire width direction end portion of the tread portion 2 as shown in FIG. 14 is damaged, and a part of the land portion 2a of the tread portion 2 and one shoulder portion 3 are damaged. Repair tire 30 with missing part. The tire 30 used in the present embodiment is different from the damaged site 9 of the tire 1 used in the first embodiment, but the other configuration is the same, and therefore the same configuration is the same. This will be described using reference numerals.

[Step 1]
The damaged part 31 of the tread part 2 and the shoulder part 3 of the tire 30 is examined, and as shown in FIG. remove. At this time, the tread portion 2 is removed with care so that the damaged portion 31 does not remain.

[Step 2]
As shown in FIGS. 16 and 19, the unvulcanized tread rubber 12 as the repair material 10 in a state of being heated and fluidized on the tread portion 2 and the shoulder portion 3 side of the tire 30 is damaged. The shape of the land portion 2a and the groove portion 2b of the missing tread portion 2 is shaped so as to be the shape of the tire 30 before the failure of the tire 30 and in an almost unused state. To repair. The new tread rubber 12 may be a tread rubber made of the same material as the tread rubber before restoration, or a tread rubber made of a different material.

[Step 3]
As described above, when the restoration part 32 whose shape has been restored by the unvulcanized tread rubber 12 is vulcanized by pressurization and heating, a mold material 15 for maintaining the shape of the unvulcanized rubber is prepared. The mold material 15 is obtained by the same operation as in the first embodiment. The work of preparing the mold material 15 may be performed after the above-described repair work is completed, or may be performed simultaneously with the repair work.

[Step 4]
As shown in FIG. 17 and FIG. 19, the mold material 15 having the fluidity before curing thus obtained is filled in the groove 2 b around the repaired portion 32 whose shape has been repaired. Further, the mold material 15 is stacked so as to have a predetermined thickness from the side direction of the tire so as to cover the restoration portion side surface 32a located on the side surface in the tire width direction of the restoration portion 32. A surface 15a in the tire radial direction of the mold member 15 covering the restoration portion side surface 32a is formed so as to be continuous with the tread surface of the tread portion 2. Of the repaired portion 32 whose shape has been repaired, the land portion 2a located at the end in the tire width direction includes a mold material 15 poured into the groove portion 2b and a mold material stacked on the side surface in the tire width direction, as shown in FIG. 15, the periphery of the restored land portion 2a on the tread surface is surrounded, and the shape of the land portion 2a is maintained.

[Step 5]
In this way, the fluid mold material 15 that fills the groove 2b and is piled on the outer edge in the tire width direction is left, and the excess moisture contained in the mold material 15 is removed while the mold material 15 is cured and dried.

[Step 6]
Next, after the mold member 15 is cured and dried, as shown in FIG. 18, the electrothermal pad 20 is disposed from the outside of the tire 30 so as to be positioned in the repair portion 32 of the tire 30 and its periphery. The electric heating pad 20 includes a restoration part 32 restored by the repair material 10 of the tread part 2, the outer surface of the tread part 2, the shoulder part 3 and the sidewall part 4 in the vicinity thereof, a mold member 15 filling the groove part 2b, and a tire. It arrange | positions along with the outer surface of the type | mold material piled up on the outer edge of the width direction. In the present embodiment, the electric heating pad 20 is disposed only on the outer side of the tire, but may be disposed on both the inner side and the outer side depending on the state and position of the repair portion 32.

[Step 7]
As shown in FIG. 18, the filling member 22 is packed inside the repaired portion 32 and the periphery of the tire 30, and the tire 30 is passed until the opening between the bead portions 5 of the tire 30 is exceeded, as in the first embodiment. Overlapping on the center side. The stuffing member 22 has a rod-like substantially cylindrical shape, and a piece of wood is used in the present embodiment, but may be made of metal, heat-resistant plastic, or the like. When the electric heating pad 20 is arranged inside the restoration portion 32 and its periphery, the padding member 22 is packed so that the electric heating pad 20 can be pressed. The stuffing member 22 thus stuffed and raised from the opening between the bead portions 5 is covered with a plate-like pressing member 23 from above, and the electric heating pad 20 arranged outside the tire 30 is covered with the cover sheet 21 to the periphery thereof. Cover with.

[Step 8]
Thereafter, as in the first embodiment (see FIG. 13), the portion of the tire 30 where the stuffing member 22 is packed is moved from the outside of the pressing member 23 and the cover sheet 21 to the long belt 24a of the tightening member 24. Is tightened so that the restoration portion 32 of the tire 30 has a predetermined pressure, and is fixed to the buckle 24b fixed to one end of the belt 24a through the other end of the belt 24a. In the present embodiment, four belts 24a are used as the fastening member 24. However, the number of belts and the width of the belts can be appropriately changed depending on the size and position of the restoration portion. Further, as the tightening member 24, a wide band may be used instead of a belt.

[Step 9]
After the restoration part 32 of the tire 30 is pressurized to a predetermined pressure, an electric current is passed through the electrothermal pad 20 to generate heat. The temperature of the electric heating pad 20 is controlled to a temperature suitable for vulcanizing the unvulcanized rubber used for repairing the tire, and the repairing part 32 is pressurized and heated for a predetermined time and vulcanized, 32 is joined to the surrounding part.

[Step 10]
In this manner, after the pressure vulcanization is performed on the repair portion 32 for a predetermined time, the fastening member 24 and the presser member 23 are removed from the tire 30, and the stuffing member 22 is taken out from the inside of the tire 30 and covered. The sheet 21 and the electric heating pad 20 are removed from the restoration part 32. Thereafter, the mold material 15 buried in the groove 2b around the repair portion 32 and the mold material 15 covering the repair portion side surface 32a are crushed and removed from the tread portion 2, and the repair work of the tire 30 is completed.

  In the second embodiment, after the shape of the shoulder portion 3 is repaired with the tread rubber 12 before vulcanization, the repair portion 32 and the surrounding groove portion 2b are filled with the mold material, and the repair portion side surface 32a is in the fluidized mold material. 15 and the uncured rubber is vulcanized after the mold 15 is cured, so even if the shoulder 3 on the side of the tread 2 of the tire 30 in the tire width direction is damaged and repair is required, the tire Repair is possible without preparing a mold or an air bag for each type and shape of the tread portion, thereby improving the workability and further reducing the cost.

In the first embodiment and the second embodiment described above, an air bag having a low thermal conductivity may be provided outside the repair material 10 such as the patch member 11 and the electric heating pad 20 disposed on the peripheral surface thereof. . Pressurization by the air bag is further applied to the unvulcanized rubber at the repair location, and there is also a heat insulation effect of the air bag, so that vulcanization of the unvulcanized rubber at the repair location can be promoted.
Further, a heat insulating material such as a rubber sheet for protection may be provided outside the air bag to further enhance the heat insulating effect.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made to the above-described embodiments without departing from the scope of the present invention. Variations and substitutions can be added. The tire repair method of the present invention is not limited to a tire for a large construction vehicle, and can be applied to a medium-to-small tire as long as it is a pneumatic tire.

DESCRIPTION OF SYMBOLS 1 ... Tire, 1a ... Tire peripheral part, 2 ... Tread part, 2a ... Land part, 2b ... Groove part, 2c ... Side edge, 3 ... Shoulder part, 4 ... Side wall part, 5 ... Bead part, 5a ... Bead ring , 6 ... carcass ply, 7 ... belt layer, 8 ... inner liner part, 9 ... damaged part, 10 ... repair material, 11 ... patch member, 11A ... reinforcing laminate, 11B ... inner liner repair rubber part, 11a ... lower laminate, 11b ... Lower laminate, 11c ... Upper laminate, 11d ... Upper laminate, 12 ... Tread rubber, 13 ... Inner liner rubber, 14 ... Restoration part, 15 ... Mold material,
20 ... electric heating pad, 21 ... cover sheet, 22 ... stuffing member, 23 ... holding member, 24 ... fastening member, 24a ... belt, 24b ... buckle,
30 ... Tire, 30a ... Tire circumferential direction part, 31 ... Damaged part, 32 ... Repair part, 32a ... Repair part side surface.

Claims (4)

Repair the shape of the damaged part of the tire with damaged tread with a repair material made of at least unvulcanized rubber,
Mix at least water and water-insoluble material in calcined gypsum to obtain a mold material in a fluid state,
The groove portion of the tread portion around the repaired portion whose shape has been repaired by the repair material is filled with the mold material in a fluid state,
After the mold material is cured and dried, a heating pad is disposed on the surface of the tread portion of the restoration portion, and the restoration portion is pressurized.
A method for repairing a tire, wherein the repaired portion is heated by the heating pad to vulcanize the unvulcanized rubber. The damaged portion is an end portion in the tire width direction of the tread portion,
The groove portion around the repair portion is filled with the mold material, and the repair portion side surface in the tire width direction side of the repair portion is covered with the mold material,
2. The tire repair method according to claim 1, wherein after the mold material is cured and dried, the unvulcanized rubber is vulcanized by pressurizing and heating the restoration portion.   The tire repair method according to claim 1 or 2, wherein at least one of rubber, wood, and metal is used as the water-insoluble member. After placing a heating pad on the surface of the tread portion of the repair portion,
The stuffing member is stuffed inside the tire in the tire circumferential direction section divided in the tire circumferential direction where the restoration part exists,
Tighten and pressurize the tire circumferential direction part from the surroundings,
The tire repair method according to any one of claims 1 to 3, wherein the repair portion is heated by the heating pad to vulcanize the unvulcanized rubber.

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