JP5112788B2 - Solid tire regeneration method - Google Patents

Description

  The present invention relates to a method for reclaiming a solid tire with a worn tread portion.

  Examples of tires used in vehicles and the like include pneumatic tires with air inside and solid tires with inside. Pneumatic tires are used in a wide range of vehicles such as automobiles with low running resistance and noise. Solid tires are used in low-speed, high-load industrial vehicles because they do not require air pressure management and have a long life. A pneumatic solid tire molded in the same outer shape as that of a pneumatic tire has been commercialized and is being developed to cope with turning and speeding up.

Such a solid tire is used and disposed of when the tread portion is largely consumed by use. However, since the solid tire can be reused if there is no problem in the wheel mounting portion, the worn tread portion is regenerated and reused. For example, Patent Document 1 describes a method for regenerating a pneumatic solid tire in which the surface of a worn tire is buffed and a reclaimed tread rubber is adhered to the tread portion. Further, in Patent Document 2, a rubber tire is removed from a baseband of a used tire, the baseband is placed in a mold, and a liquid ether-based urethane elastomer polymer is injected into the mold to cure the polymer. A method for regenerating a urethane rubber tire to be molded is described. Further, in Patent Document 3, the tread rubber on the outer periphery of the old tire is scraped off with a buff device, rubber paste is applied to the scraped outer peripheral surface, a rubber band for rehabilitation is applied, set in a mold, A method for producing a retread tire in which pressure is applied to secure a retread rubber band is described.
JP-A-5-31822 JP 2002-144442 A JP 2004-291251 A

  As described in Patent Documents 1 and 3, the reclaiming method in which the tread rubber for regeneration is attached to the outer peripheral surface of the buffed solid tire and integrated is easy. There is a problem that it is easy to peel off. As described in Patent Document 2, although the method of curing and regenerating a liquid polymer is improved with respect to peeling, the manufacturing process becomes complicated and the cost burden for the regeneration process increases.

  Accordingly, an object of the present invention is to provide a regeneration method that can easily regenerate a tread portion of a solid tire and that the regenerated tread portion is difficult to peel off.

The method for reclaiming a solid tire according to the present invention removes at least a deteriorated portion of the worn tread portion of the solid tire to form a processed surface on the outer peripheral surface, and adheres a natural rubber sheet to the entire formed processed surface. A compound rubber sheet containing a vulcanizing agent is piled on the surface of the natural rubber sheet so as to have a predetermined thickness and wound to form a processed rubber layer, and a solid tire formed with the processed rubber layer is formed into a tire groove forming mold The tire groove forming die is pressed against the processed rubber layer and heat-treated while being compressed toward the center of the tire, and the processed rubber layer is vulcanized and integrated to form a tire groove The recycled tread portion thus formed is formed. Further, the processed surface is formed by removing the deteriorated surface portion of the side portion of the solid tire, and the processed rubber layer is melted and integrally formed so as to cover the processed surface during the heat treatment. .

  By having at least the above-described configuration, a compounded rubber sheet containing a vulcanizing agent is obtained after at least a deteriorated portion of a tread portion of a worn solid tire is removed and a natural rubber sheet is bonded to a processed surface formed on an outer peripheral surface. Since the processed rubber layer formed by wrapping is vulcanized and integrally molded, a recycled tread portion that is difficult to peel can be easily molded.

  In other words, since the processed rubber layer is integrally formed on the processed surface of the solid tire via the natural rubber sheet, the combined natural rubber improves the bonding force between the processed surface and the regenerated tread portion and makes it difficult to peel off. When the tread rubber is directly bonded to the processed surface as in the past, the tread rubber is pressure-bonded to the processed surface of the solid tire that has been hardened, but the two are not in close contact with each other. When the natural rubber is used for pressure bonding, the soft natural rubber is brought into close contact with each other, and a sufficient bonding force is generated between the two and the natural rubber, which makes it difficult to peel off. And since the reproduction | regeneration tread part became difficult to peel, the product lifetime can be extended.

  Further, since the heat treatment is performed while compressing in the mold after forming the processed rubber layer via the natural rubber sheet, the regeneration process can be easily performed, and the regeneration cost can be suppressed.

  Then, if the processed surface is formed by removing the deteriorated surface portion of the side portion of the solid tire and the processed rubber layer is melted and integrally formed so as to cover the processed surface during the heat treatment, the solid tire The outer surface of the tire is covered with a processed rubber layer, which makes it more difficult to peel off and allows the appearance to be inferior to that of a new product.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  1-6 is explanatory drawing which shows the process regarding embodiment which concerns on this invention. The worn and deteriorated tread portion T1 and the deteriorated side portion T2 of the used tire T are removed by a known buffing device (FIG. 1) to form smooth processed surfaces S1 and S2 with little rubber deterioration (FIG. 2). ). The tread portion T1 may be removed by the same thickness, and the processed surface S1 may be formed in the outer peripheral direction of the base portion having the same thickness.

  Next, an adhesive such as rubber paste is applied to the formed processed surface S1, and a belt-like natural rubber sheet G1 is adhered to the entire processed surface S1. The natural rubber sheet G1 has a thickness of 1 mm to 1.5 mm and is formed to have substantially the same width as the processed surface S1, and is stuck so as to cover the entire periphery of the processed surface S1 (FIG. 3). As a material for the natural rubber sheet, RSS (sheet rubber) is preferably obtained by adding an acid (formic acid, acetic acid, etc.) to a latex solution and solidifying it, and then smoking a sheet that has been stretched by a roller.

  A compounded rubber sheet G2 containing a vulcanizing agent is wound around the outer surface of the adhered natural rubber sheet G1 (FIG. 4 (a)), and it is wrapped and wound so as to have a predetermined thickness. A layer is formed (FIG. 4B). The compounded rubber sheet G2 is formed in a belt shape and the same width as the natural rubber sheet G1, and is obtained by extruding a rubber material having the same composition as the compounded rubber used for the tread portion of the tire into a sheet shape. The compounded rubber material is obtained by kneading a compounding agent such as a vulcanization accelerator and a reinforcing material in addition to a vulcanizing agent in a raw rubber and can be produced by a known compounding method. Normally, black is used because carbon black is used as a reinforcing material. However, a colored compounded rubber material such as white or green may be used by adding various colorants. For example, when used in a vehicle used in a factory, if a white compounded rubber material is used, it can be regenerated as a white tire.

  The amount of the compounded rubber sheet G2 to be wound and laminated is set so as to be thicker than the thickness of the finished reproduction trad portion in consideration of compression by a mold described later to form a tire groove. In addition, an amount necessary for covering the tire side portion T2 with the compounded rubber material at the time of compression molding is also taken into consideration.

  Next, the tire T, in which the compounded rubber sheet G2 is wound and the processed rubber layer is formed on the processed surface S1, is set in a mold, compressed and heated to vulcanize the compounded rubber material, and the processed rubber layer is applied to the tire T. One-piece molding.

  FIG. 7 is an external perspective view showing an example of a processing apparatus for performing compression and heating. The processing apparatus 10 includes a base 11, and a bottom mold 13 having a cylindrical mounting shaft 12 on which a tire is mounted is installed on the base 11. Around the bottom mold 13, six divided molds 14 having tire groove forming molds are arranged. The divided mold 14 has a circle centered on the central axis of the mounting shaft 12. It is formed in a divided arc shape. The divided molds 14 are arranged on the upper surface of the base 11, and are attached so as to be movable toward or away from the mounting shaft 12.

  A tire groove forming die 20 is attached to the inner surface of the divided mold frame 14, and the tire groove forming die 20 has six pieces corresponding to groove shapes obtained by dividing the tire groove formed on the entire circumference of the tire into six. Are set in each divided mold 14. As shown in FIG. 8, the tire groove forming mold 20 has linear protrusions 20a corresponding to the tire grooves formed on the inner surface, and a rubber material melted in a recess region 20b surrounded by the protrusions 20a. Filled to form a tread portion. As a tire groove, for example, a tire groove corresponding to a studless can be formed in addition to a normal tire groove, and various shapes of tire grooves can be formed depending on applications.

  A ring-shaped clamping frame 16 is disposed so as to surround the outer peripheral surface of the divided molds 14 arranged in a circle, and a plurality of support rods 17 that support the clamping frame 16 are formed at the bottom of the base 11. The raised flange portion 15 is erected. The support rod 17 is configured such that the shaft portion is inserted into the outer cylindrical portion and is advanced and retracted by a hydraulic device (not shown), and the entire length of the support rod 17 is expanded and contracted by the advance and retract operation of the shaft portion. The fastening frame 16 moves up and down.

  As shown in FIGS. 9 and 10, tapered sliding protrusions are formed on the outer peripheral surface of each divided mold 14 in the vertical direction, and the protruding width of the sliding protrusions increases as it goes downward. Is set to The tightening frame 16 moves up and down while sliding the inner peripheral surface thereof in sliding contact with the sliding projections of the respective divided molds 14 so that the divided molds 14 are gathered and separated toward the mounting shaft 12. It is supposed to let you. When the tightening frame 16 moves upward, the projecting width of the sliding projection becomes smaller, so that each divided mold 14 spreads apart from each other and a gap is left between them (see FIG. 9). ). Further, when the tightening frame 16 moves downward, the protruding width of the sliding projection portion increases, so that each divided mold frame 14 is pushed toward the mounting shaft 12 and tightened so as to be in close contact with each other. It is set so as to form a circular formwork (see FIG. 10).

  Above the processing apparatus 10, a lid body 18 to which an upper mold frame is attached is provided so as to move up and down. When setting a tire, the lid body 18 is retracted upward to open the inside of the processing apparatus 10. When the compression process is performed, the lid 18 is lowered and positioned in an area surrounded by the upper part of the divided mold 14.

  FIG. 5 is an explanatory diagram showing a tire compression / heating process performed by the processing apparatus 10. First, the tire T on which the processed rubber layer is formed is set in the processing apparatus 10 that is opened by removing the lid 18. When the tire T is set, the center hole portion of the tire T is fitted into the mounting shaft 12 and set on the bottom mold 13 (FIG. 5A). At that time, the fastening frame 16 moves upward, and the tapered sliding projection 14a projecting from the outer peripheral surface of each divided mold frame 14 has a small protruding width on the upper side. The frame 14 is spread so as to be discrete from each other, and an opening portion into which the tire T can be easily inserted is formed.

  After the tire T is set, the lid 18 is lowered and positioned in the opening surrounded by each divided mold 14. At that time, the insertion shaft 19a of the upper mold 19 attached to the lower surface of the lid 18 is inserted into the mounting shaft 12 and positioned (FIG. 5B). In the state where the lid 18 is positioned, the joints projecting up and down of each divided mold 14 are set to face the outer peripheral surfaces of the upper mold 19 and the bottom mold 13, respectively.

  After the lid 18 is positioned, a hydraulic device (not shown) is operated to move the fastening frame 16 downward. When the fastening frame 16 moves downward, the divided molds 14 are pushed toward the mounting shaft 12 so as to gather together to form a circular continuous mold, and the upper and lower joints are respectively connected to each other. A tightly sealed space is formed on the outer peripheral surfaces of the upper mold 19 and the bottom mold 13 (FIG. 5C). At that time, the tire groove forming mold 20 attached to the inner surface of each divided mold 14 is pressed against the rubber processing layer of the tire T and acts to compress the rubber processing layer toward the center of the tire.

  In this state, the mold is heated with steam or the like while being compressed by the mold, and is set to 120 ° C. to 150 ° C., and heat treatment is performed for 2 to 3 hours.

  After such compression and heat treatment, the fastening frame 16 is moved upward to expand and separate the divided molds 14, and the lid 18 is moved upward to be removed, and the regenerated tire T 'is taken out. As shown in FIG. 6, by performing the above-described compression / heating treatment, the reclaimed portion having a sufficient adhesive force by the natural rubber sheet is obtained by vulcanizing the compound rubber material in the tread portion T1 ′ of the regenerated tire T ′. A single tire groove is formed by the tire groove forming mold 20 to form a continuous tire groove. Further, the side portion T2 'is thinly covered with a molten compounded rubber material and molded by the mold surfaces of the upper mold frame 19 and the bottom mold frame 13. For this reason, the entire recycled tire T ′ is covered with recycled rubber, and has an appearance that is inferior to a new one.

  The regeneration processing shown in FIGS. 1 to 5 was performed using a used forklift tire (Pneumatic solid tire manufactured by Dunlop Falken Tires; tire size 6.00-9). A natural rubber sheet manufactured by AMAX Co. (thickness 1 mm) was used, and a compounded rubber material manufactured by INB Planning Co., Ltd. was molded into a sheet shape having a thickness of 12 mm. The processed rubber layer was formed to a thickness of 45 mm, and the compression force of the processing apparatus 10 was 6000 kg, the heating temperature was 140 ° C., and the heating time was 2.5 hours.

  The recycled tire was formed with a recycled tread portion having a thickness of 40 mm and had sufficient adhesive strength.

It is process drawing regarding embodiment which concerns on this invention. It is process drawing regarding embodiment which concerns on this invention. It is process drawing regarding embodiment which concerns on this invention. It is process drawing regarding embodiment which concerns on this invention. It is process drawing regarding embodiment which concerns on this invention. It is the external view and sectional drawing regarding the reproduced tire. It is an external appearance perspective view regarding a processing apparatus. It is a front view regarding a tire groove forming mold. It is explanatory drawing regarding operation | movement of a processing apparatus. It is explanatory drawing regarding operation | movement of a processing apparatus.

Explanation of symbols

10 Processing equipment
11 base
12 Mounting shaft
13 Bottom formwork
14 Split formwork
15 Flange
16 Tightening frame
17 Support rod
18 Lid
19 Upper formwork
20 Tire groove forming mold

Claims (3)

At least the deteriorated part of the worn tread part of the solid tire is removed to form a processed surface on the outer peripheral surface, a natural rubber sheet is bonded to the entire processed surface, and a vulcanizing agent is applied to the surface of the bonded natural rubber sheet tire compounded rubber sheet is wound repeatedly to a predetermined thickness to form a processed rubber layer, the solid tire of processing rubber layer is formed is set in the mold within which includes a tire groove forming mold comprising The groove forming mold is pressed against the processed rubber layer and heated while being compressed toward the center of the tire, and the processed rubber layer is vulcanized and integrated to form a recycled tread portion in which a tire groove is formed. A method for recycling solid tires.   The processed surface is formed by removing the deteriorated surface portion of the side portion of the solid tire, and the processed rubber layer is integrally formed so as to melt and cover the processed surface during the heat treatment. 2. The reproduction method according to 1.   A solid tire regenerated by the regeneration method according to claim 1.

Images