JP5277983B2 - Pneumatic tire manufacturing method and pneumatic tire - Google Patents

Description

  The present invention relates to a method for manufacturing a pneumatic tire and a pneumatic tire manufactured by the method, and more particularly to a method for manufacturing a pneumatic tire and a pneumatic tire for improving productivity.

  Conventionally, for example, a bead filler is known as a tire constituent member made of a thermoplastic elastomer or a thermoplastic elastomer composition obtained by blending a thermoplastic resin component and an elastomer component. By configuring the bead filler from a thermoplastic resin or a thermoplastic elastomer composition, it is possible to reduce the size and weight of the bead filler without deteriorating road noise in a very low frequency band in the frequency band near 40 Hz. (For example, refer to Patent Document 1).

  On the other hand, a technique (strip wind method) for forming a tire constituent member using a strip material is well known (for example, see Patent Document 2). Usually, the tire component is molded while winding the strip material on a molding machine for attaching each tire component. By adopting this strip wind method, there is an advantage that the influence of the splice portion can be eliminated and the uniformity in the circumferential direction of the tire constituent member can be improved.

  However, when this strip wind method is used for molding a tire component made of the thermoplastic resin or thermoplastic elastomer composition described above, there are the following problems. That is, since the tire constituent member is formed while winding the strip material on the molding machine, the time required for forming the tire constituent member is increased, and the productivity is lowered. In particular, when the number of windings is large, the decrease in productivity becomes significant.

Japanese Patent No. 3695840 JP 2004-9622 A

  An object of the present invention is to provide a method for manufacturing a pneumatic tire and a pneumatic tire capable of improving productivity when a tire constituent member is molded from a strip material made of a thermoplastic resin or a thermoplastic elastomer composition. There is.

The method for producing a pneumatic tire according to the present invention that achieves the above object includes a tire configuration in which a strip material made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending a thermoplastic resin component and an elastomer component is wound in the tire circumferential direction. When forming a green tire provided with a member, it has a structure in which the strip material is laminated in the tire radial direction in advance , and the tension applied to the portion located on the outer side in the tire radial direction is reduced to reduce the tension . The said tire structural member shape | molded by rotating is attached, and the said green tire is shape | molded, It is characterized by the above-mentioned.

  The pneumatic tire of the present invention is manufactured by the method for manufacturing a pneumatic tire described above.

  According to the above-described present invention, the tire component is formed by winding the strip material in advance, and it is attached at the time of forming the green tire, so the time for forming the green tire is shortened and the productivity is improved. can do.

It is a fragmentary sectional view showing one embodiment of the pneumatic tire manufactured by the manufacturing method of the pneumatic tire of the present invention. It is explanatory drawing which shows the process of attaching an unvulcanized inner liner layer and a carcass layer in one Embodiment of the manufacturing method of the pneumatic tire of this invention. In one Embodiment of the manufacturing method of the pneumatic tire of this invention, it is explanatory drawing which shows the process of attaching the bead core which has arrange | positioned the bead filler on the outer peripheral side. In one Embodiment of the manufacturing method of the pneumatic tire of this invention, it is explanatory drawing which shows notionally the process of shape | molding a bead filler. It is explanatory drawing which shows an example of the process of adjusting the shape of a bead filler. It is explanatory drawing which shows the other example of the process of adjusting the shape of a bead filler. It is sectional drawing which shows an example of the coated bead filler. In one Embodiment of the manufacturing method of the pneumatic tire of this invention, it is explanatory drawing which shows the state which shape | molded the 1st molded object on the forming drum. In one Embodiment of the manufacturing method of the pneumatic tire of this invention, it is explanatory drawing which shows the process of shape | molding a green tire by expanding a 1st molded object and crimping | bonding to a 2nd molded object. It is explanatory drawing which shows the principal part of other embodiment of the manufacturing method of the pneumatic tire of this invention. It is explanatory drawing which shows the process of shape | molding the other example of a bead filler.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows an example of a pneumatic tire manufactured by the method for manufacturing a pneumatic tire of the present invention, where 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion.

  A carcass layer 4 embedded in a rubber layer with reinforcing cords extending in the tire radial direction between the left and right bead portions 3 arranged at predetermined intervals in the tire circumferential direction is extended, and both end portions thereof are embedded in the bead portion 3 The bead filler 6 having a substantially triangular cross section is sandwiched around the bead core 5 and folded back from the inner side to the outer side in the tire axial direction. The annular bead filler 6 disposed on the outer peripheral side of the bead core 5 is composed of a thermoplastic elastomer or a thermoplastic elastomer composition obtained by blending a thermoplastic resin component and an elastomer component.

  An inner liner layer 7 is disposed inside the carcass layer 4. A plurality of belt layers 8 are provided on the outer peripheral side of the carcass layer 4 of the tread portion 1. A tread rubber layer 9 is disposed on the outer peripheral side of the belt layer 8. A side rubber layer 10 is disposed outside the carcass layer 4 of the sidewall portion 2. A rim cushion rubber layer 11 is provided outside the folded portion of the carcass layer 4 of the bead portion 3.

  Hereinafter, a method for manufacturing the pneumatic tire of FIG. 1 by the manufacturing method of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 2, the unvulcanized inner liner layer 7 and the unvulcanized carcass layer 4 are sequentially attached (attached) on the forming drum 21. Next, as shown in FIG. 3, the bead core 5 in which the bead filler 6 is disposed on the outer peripheral side is attached.

  As shown in FIG. 4, the bead filler 6 is formed on the outer peripheral surface 5 </ b> A of the bead core 5 by winding one or a plurality of strip materials S made of a thermoplastic resin or a thermoplastic elastomer composition in a ring shape in advance. deep. While rotating the bead core 5 held by the holding means 32 having the forming auxiliary surface 31, the strip material S to which tension is applied is sequentially wound around the outer peripheral surface 5A.

  The bead filler 6 has a structure in which the strip material S is laminated in the tire radial direction. In such a laminated structure, the strip material S is applied to a portion located on the outer side in the tire radial direction (upper side in FIG. 4). Wind with reduced tension. That is, when the strip material S is wound, the winding tension is higher in the portion located on the inner side in the tire radial direction, the tension is gradually decreased, and the winding tension is gradually decreased on the outer side in the tire radial direction.

  When the bead filler 6 is molded with the strip material S using a thermoplastic resin or a thermoplastic elastomer composition, the number of windings increases. In the case of a thin and high cross-sectional shape, the number of windings is further increased. In order to stabilize the shape of such a bead filler 6, it is necessary to control the tension of the strip material S to be wound, and as described above, tension control is performed to gradually decrease the winding tension toward the outer side in the tire radial direction. It is.

Assuming that the tension of the strip material S is T (N), the elastic modulus (storage elastic modulus) is E (Pa), and the cross-sectional area is A (m ² ), from the center position of the tire cross-section height SH to the inside in the tire radial direction. T = (0.01 to 0.15) × E × A, T = (0.001 to 0.01) × E × A on the outer side in the tire radial direction from the center position of the tire cross-section height SH. Good from the point of uniformity. The storage elastic modulus referred to in the present invention is a storage elastic modulus measured using a viscoelasticity spectrometer manufactured by Toyo Seiki Seisakusho under the conditions of static strain 10%, dynamic strain ± 2%, frequency 20 Hz, and temperature 20 ° C. It is.

  As shown in FIG. 5, the bead filler 6 is preferably formed by pressing a molding die 33 for adjusting the shape of the bead filler 6 to adjust the shape of the bead filler 6. When the strip material S is wound and formed, a step is generated in adjacent portions, and air is easily trapped between the stacked portions, which may be an obstacle in the vulcanization process. Therefore, by pressing the molding die 33 and adjusting the shape, the step can be corrected and the trapped air can be dispersed or discharged to the outside. More preferably, heating the bead filler 6 during molding by the molding die 33 may improve the shape. The molding die 33 is preferably configured so that it can be molded so as to have the final member shape of the bead filler 6.

  Instead of the molding die 33, as shown in FIG. 6, a rotatable molding roller 34 may be used and pressed against one surface of the bead filler 6 while rotating it to adjust the shape.

Bead filler 6 that adjust the shape is preferably as shown in FIG. 7, be coated with unvulcanized rubber layer 12, good in terms of adhesion to the carcass layer 4 of unvulcanized adjacent. The unvulcanized rubber layer 12 preferably covers the entire outer surface of the bead filler 6 exposed to the outside, but the outer surface may be partially covered. The bead filler 6 and the unvulcanized rubber layer 12 are preferably bonded via an adhesive. The unvulcanized rubber layer 12 may be the same kind of rubber as the uncured carcass layer 4 that is an adjacent tire constituent member, and is an intermediate physical between the constituent material of the bead filler 6 and the rubber of the carcass layer 4. It may have a characteristic and can be suitably selected as needed.

  After the bead filler 6 molded in advance as described above is attached together with the bead core 5, the unvulcanized rim cushion rubber layer 11 and the unvulcanized side rubber layer 10 are attached in the same manner as in the prior art, so The 1st molded object 14 is shape | molded (refer FIG. 8).

  The first molded body 14 is removed from the molding drum 21 and attached to the shaping drum 22 as shown in FIG. 9 to apply an internal pressure, whereby the first molded body 14 is expanded in a toroidal shape. The green tire is molded by pressure bonding to the inner peripheral side of the annular second molded body 15 in which the unvulcanized tread rubber layer 9 is bonded to the outer peripheral side of the unvulcanized belt layer 8 disposed on the outer peripheral side of the belt. . This green tire is pressurized and heated in a mold and vulcanized to obtain the pneumatic tire of FIG.

  As described above, in the present invention, a green tire including the bead filler 6 in which the strip material S made of the thermoplastic elastomer composition obtained by blending the thermoplastic resin or the thermoplastic resin component and the elastomer component is wound in the tire circumferential direction is molded. In doing so, the strip material S is wound on the forming drum 21 and the bead filler 6 is not formed, but the strip material S is wound in advance to form the bead filler 6 and is attached when the green tire is formed. The green tire molding time can be shortened and the productivity can be improved.

  FIG. 10 shows another embodiment of the method for manufacturing a pneumatic tire of the present invention. In this manufacturing method, instead of the forming drum 21, a separable rigid core 23 having an inner shape of a tire is used, and each tire constituent member is attached on the rigid core 23 to form a green tire. It is a thing. Also in such a manufacturing method, without stripping the strip material S on the rigid core 23 to form the bead filler 6, the strip material S is wound in advance as shown in FIG. It may be formed on the top and attached at the time of forming the green tire as shown in FIG.

  In the present invention, when the bead filler 6 having a substantially triangular cross section as described above is formed using the strip material S, preferably, the bead filler 6 is made of a thermoplastic resin or a thermoplastic elastomer composition as shown in FIG. A main body 6A having a structure in which a strip material S made of the above is laminated in the tire radial direction and a rubber portion 6B arranged on the outer peripheral side of the main body 6A, and the main body 6A is wound by winding the strip material S as described above. After molding, it is preferable that the rubber portion 6B is molded by winding an unvulcanized rubber strip material (unvulcanized rubber material) R around the outer peripheral side of the main body portion 6A. Thereby, the rigidity change at the boundary surface between the outer peripheral end of the bead filler 6 where the stress concentration is likely to occur and the adjacent tire constituent member can be smoothed, and the durability can be enhanced.

  The above-described strip material S is formed in a quadrangular shape such as a rectangular cross section. In the case of a thermoplastic resin, a strip material having a width of 5 to 30 mm and a thickness of 0.1 to 0.4 mm can be preferably used. . In the case of a thermoplastic elastomer composition, those having a width of 5 to 30 mm and a thickness of 1.0 to 5.0 mm can be preferably used. If the width and thickness are smaller than the above ranges, the degree of freedom of shape is reduced (it is difficult to obtain a desired shape). Conversely, if the above ranges are exceeded, dimensional stability is deteriorated.

  The elastic modulus (storage elastic modulus) of the thermoplastic resin or thermoplastic elastomer composition used for the strip material S is preferably 50 to 500 MPa from the viewpoint of reduction in size and weight. If the elastic modulus is less than 50 MPa, the hardness of the bead filler 6 becomes too low, and it becomes difficult to obtain circumferential rigidity equivalent to that of a bead filler made of conventional rubber with a smaller cross-sectional area. On the other hand, when it exceeds 500 MPa, the hardness of the bead filler 6 becomes too high, so that the bead filler 6 is easily broken and causes a tire failure.

  In the present invention, the thermoplastic resin used for the strip material S is, for example, a polyamide resin [for example, nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6/66 copolymer (N6 / 66), nylon 6/66/610 copolymer (N6 / 66/610), nylon MXD6 (MXD6 ), Nylon 6T, nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymer] and their N-alkoxyalkylated products, for example, methoxymethylated products of nylon 6, nylon 6 / 610 copolymer methoxymethylated product, nylon 612 methoxymethylated product, polyester Resins [eg, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, polyoxy Aromatic polyesters such as alkylenediimide diacid / polybutylene terephthalate copolymer], polynitrile resins [for example, polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile / styrene copolymer (AS), (meth) acrylonitrile / Styrene copolymer, (meth) acrylonitrile / styrene / butadiene copolymer], polymethacrylate resin [eg, polymethyl methacrylate (PMMA), polyethyl methacrylate], polyvinyl Resins [eg, vinyl acetate, polyvinyl alcohol (PVA), vinyl alcohol / ethylene copolymer (EVOH), polyvinylidene chloride (PDVC), polyvinyl chloride (PVC), vinyl chloride / vinylidene chloride copolymer, vinylidene chloride / Methyl acrylate copolymer, vinylidene chloride / acrylonitrile copolymer], cellulose resin [for example, cellulose acetate, cellulose acetate butyrate], fluorine resin [for example, polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), poly Chlorfluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer], imide resin [for example, aromatic polyimide (PI)] and the like can be preferably used.

  The thermoplastic elastomer composition can be constituted by mixing an elastomer component with the above-described thermoplastic resin component. Examples of the elastomer used include diene rubbers and hydrogenated products thereof [for example, natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene bradiene rubber (SBR), bradiene rubber (BR, high Cis BR and low cis BR), nitrile rubber (NBR), hydrogenated NBR, hydrogenated SBR], olefin rubber [for example, ethylene propylene rubber (EPDM, EPM), maleic acid modified ethylene propylene rubber (M-EPM), Butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), ionomer], halogen-containing rubber [for example, Br-IIR, CI-IIR, bromine of isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (CR), hydride Rubber (CHR), chlorosulfonated polyethylene rubber (CSM), chlorinated polyethylene rubber (CM), maleic acid-modified chlorinated polyethylene rubber (M-CM)], silicone rubber [eg, methyl vinyl silicone rubber, dimethyl silicone rubber, Methyl phenyl vinyl silicon rubber], sulfur-containing rubber (for example, polysulfide rubber), fluorine rubber (for example, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicon rubber, fluorine-containing phosphazene) Rubbers], thermoplastic elastomers [for example, styrene elastomers, olefin elastomers, ester elastomers, urethane elastomers, polyamide elastomers] and the like can be preferably used.

  When the above-mentioned specific thermoplastic resin component and the elastomer component are different in compatibility, they can be made compatible by using a suitable compatibilizer as the third component. By mixing the compatibilizer with the blend system, the interfacial tension between the thermoplastic resin and the elastomer component is reduced, and as a result, the particle size of the rubber forming the dispersion layer becomes fine. It will be expressed more effectively. As such a compatibilizing agent, generally a copolymer having a structure of both or one of the thermoplastic resin and the elastomer component, or an epoxy group, a carbonyl group, a halogen group, which can react with the thermoplastic resin or the elastomer component, The structure of a copolymer having an amino group, an oxazoline group, a hydroxyl group and the like can be taken. These may be selected according to the kind of the thermoplastic resin and the elastomer component to be mixed, but those usually used include styrene / ethylene butylene block copolymer (SEBS) and its maleic acid modified product, EPDM, EPM. EPDM / styrene or EPDM / acrylonitrile graft copolymer and its maleic acid modified product, styrene / maleic acid copolymer, reactive phenoxin and the like. The amount of the compatibilizing agent is not particularly limited, but is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymer component (the total of the thermoplastic resin and the elastomer component).

  The composition ratio between the specific thermoplastic resin component (A) and the elastomer component (B) in the case of blending the thermoplastic resin and the elastomer is not particularly limited, and may be appropriately determined depending on the elastic modulus and the cross-sectional area of the strip material. However, the preferred range is 90/10 to 30/70 by weight.

  In addition to the essential polymer component, the thermoplastic elastomer composition according to the present invention includes other polymers such as the above-described compatibilizer polymer as long as the necessary characteristics of the thermoplastic elastomer composition for tires of the present invention are not impaired. Can be mixed. The purpose of mixing other polymers is to improve the compatibility between the thermoplastic resin and the elastomer component, to improve the molding processability of the material, to improve heat resistance, to reduce costs, etc. Examples of the material used include polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS, SBS, and polycarbonate (PC). The thermoplastic elastomer composition according to the present invention further includes a filler (calcium carbonate, titanium oxide, alumina, etc.), a reinforcing agent such as carbon black and white carbon, a softener, a plasticizer, etc. Agents, processing aids, pigments, dyes, anti-aging agents, and the like can be arbitrarily added as long as the above elastic modulus requirements are not impaired.

  The elastomer component can also be dynamically vulcanized when mixed with a thermoplastic resin. The vulcanizing agent, vulcanization aid, vulcanization conditions (temperature, time), etc. when dynamically vulcanizing may be appropriately determined according to the composition of the elastomer component to be added, and are not particularly limited. .

  A general rubber vulcanizing agent (crosslinking agent) can be used as the vulcanizing agent. Specific examples of the sulfur vulcanizing agent include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, alkylphenol disulfide, and the like. About 4 phr [phr: parts by weight per 100 parts by weight of a rubber component (elastomer)] can be used.

  Organic peroxide vulcanizing agents include benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di (t-butyl peroxide). Oxy) hexane, 2,5-dimethylhexane-2,5-di (peroxylbenzoate), etc. are exemplified, and for example, about 1 to 20 phr can be used.

  Furthermore, examples of the phenol resin-based vulcanizing agent include bromides of alkyl phenol resins, mixed crosslinking systems containing halogen donors such as tin chloride and chloroprene, and alkyl phenol resins. For example, about 1 to 20 phr is used. Can do. In addition, zinc white (about 5 phr), magnesium oxide (about 4 phr), risurge (about 10-20 phr), p-quinonedioxime, p-dibenzoylquinonedioxime, tetrachloro-p-benzoquinone, poly-p- Examples thereof include dinitrosobenzene (about 2 to 10 phr) and methylenedianiline (about 0.2 to 10 phr).

  Moreover, you may add a vulcanization accelerator as needed. Examples of the vulcanization accelerator include general vulcanization accelerators such as aldehyde / ammonia, guanidine, thiazole, sulfenamide, thiuram, dithioate, thiourea, etc. About 2 phr can be used. Specifically, as the aldehyde / ammonia vulcanization accelerator, hexamethylenetetramine and the like, as the guanidinium vulcanization accelerator, diphenyl guanidine, etc., as the thiazole vulcanization accelerator, dibenzothiazyl disulfide ( DM), 2-mercaptobenzothiazole and its Zn salt, cyclohexylamine salt and the like, sulfenamide vulcanization accelerators include cyclohexylbenzothiazylsulfenamide (CBS), N-oxydiethylenebenzothiazyl-2- As thiuram vulcanization accelerators such as sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, 2- (thymolpolynyldithio) benzothiazole, tetramethylthiuram disulfide (TMTD), tetraethyl Thiuram disulfide, tetrame Examples of dithioate-based vulcanization accelerators such as lutiuram monosulfide (TMTM) and dipentamethylene thiuram tetrasulfide include Zn-dimethyldithiocarbamate, Zn-diethyldithiocarbamate, Zn-di-n-butyldithiocarbamate, Zn -Ethylphenyldithiocarbamate, Te-diethyldithiocarbamate, Cu-dimethyldithiocarbamate, Fe-dimethyldithiocarbamate, pipecoline pipecolyldithiocarbamate, etc. Examples of thiourea vulcanization accelerators include ethylenethiourea, diethylthiourea, etc. be able to.

Moreover, as a vulcanization | cure acceleration | stimulation adjuvant, the general rubber adjuvant can be used together, for example, zinc white (about 5 phr), stearic acid, oleic acid, and these Zn salts (about 2-4 phr) Etc. can be used. A method for producing a thermoplastic elastomer composition is a method in which a thermoplastic resin component and an elastomer component (unvulcanized product in the case of rubber) are previously melt-kneaded with a twin-screw kneading extruder or the like to form a continuous phase (matrix). By dispersing the elastomer component as a dispersed phase (domain) in the plastic resin. When vulcanizing the elastomer component, a vulcanizing agent may be added under kneading to dynamically vulcanize the elastomer component. Further, various compounding agents (excluding the vulcanizing agent) to the thermoplastic resin or the elastomer component may be added during the kneading, but are preferably mixed in advance before kneading. The kneading machine used for kneading the thermoplastic resin and the elastomer component is not particularly limited, and a screw extruder, a kneader, a Banbury mixer, a biaxial kneading extruder, or the like can be used. Among them, it is preferable to use a twin-screw kneading extruder for kneading the thermoplastic resin and the elastomer component and for dynamic vulcanization of the elastomer component. Further, two or more types of kneaders may be used and kneaded sequentially. As conditions for melt kneading, the temperature may be higher than the temperature at which the thermoplastic resin melts. Moreover, it is preferable that the shear rate at the time of kneading | mixing is 1000-7500Sec < ^-1 >. The entire kneading time is from 30 seconds to 10 minutes, and when a vulcanizing agent is added, the vulcanization time after addition is preferably from 15 seconds to 5 minutes. The thermoplastic elastomer composition produced by the above method may be formed into a desired strip shape by an ordinary thermoplastic resin molding method such as injection molding or extrusion molding.

  The strip material S thus obtained has a structure in which the elastomer component (B) is dispersed as a discontinuous phase in the matrix of the thermoplastic resin (A). By adopting such a structure, the bead filler 6 can be provided with sufficient flexibility and sufficient rigidity due to the effect of the resin layer as a continuous phase, and thermoplasticity during molding regardless of the amount of the elastomer component. Molding processability equivalent to resin can be obtained.

  Adhesion with the tire constituent member adjacent to the bead filler 6 is performed by applying an adhesive in which a usual rubber-based, phenolic resin-based, acrylic copolymer-based, isocyanate-based polymer and a crosslinking agent are dissolved in a solvent to the bead filler, Adhesive resin such as styrene butadiene styrene copolymer (SBS), ethylene ethyl acrylate (EEA), styrene ethylene butylene block copolymer (SEBS), etc. In addition, there is a method in which a multilayer laminate is prepared by co-extrusion or lamination together and adhered to an adjacent tire constituent member during vulcanization. Examples of the solvent-based adhesive include phenol resin (Chemlock 220, Rhode), chlorinated rubber (Chemlock 205, Chemlock 234B), isocyanate (Chemlock 402), and the like.

  In the above-described embodiment, the present invention shows an example in which the bead filler 6 is molded using the strip material S made of a thermoplastic elastomer composition obtained by blending a thermoplastic resin or a thermoplastic resin component and an elastomer component. Can be used for molding a reinforcing layer made of a thermoplastic resin or a thermoplastic elastomer composition, for example, disposed on a sidewall portion, and the bead filler 6 that is a tire constituent member described above. It is not limited.

  The tire size is common to 195 × 65R15, and a strip material (width 10 mm, thickness 3 mm) made of a thermoplastic elastomer composition (elastic modulus 60 MPa) shown in Table 1 is used as a bead filler. A green tire having the configuration shown in FIG. 1 was molded by attaching the molded bead filler (located on the inner side in the tire radial direction from the center position of the tire cross-section height SH) (Example). Moreover, the same green tire was shape | molded by winding a strip material on a molding machine and shape | molding a bead filler (comparative example). In both cases, the tension and the winding speed for winding the strip material are constant.

  When the molding time until the molding of each green tire was completed was measured, the results shown in Table 2 were obtained. The molding time in Table 2 is an index value with the measurement result of the comparative example as 100. The larger the index value, the shorter the molding time and the better the productivity.

表２から、本発明は、成形時間を短縮し、生産性を改善できることがわかる。

From Table 2, it can be seen that the present invention can shorten the molding time and improve the productivity.

  The tire size and the strip material to be used are the same as those in Example 1, and in the manufacturing method of the present invention, the test tire 1 having the structure shown in FIG. Example 1) and 100 test tires 2 (Test Example 2) each having a structure shown in FIG. 1 in which bead fillers were formed by gradually reducing the winding tension in the tire radial direction within the range of 1N to 20N were manufactured.

  Each of these test tires was mounted on a rim with a rim size of 15 × 6J, the air pressure was set to 200 kPa, and the uniformity yield was measured when measuring RFV (radial force variation) with a uniformity machine. The results shown in Table 3 were obtained. It was.

表３から、ストリップ材の巻き付け張力を径方向外側ほど漸減させてビードフィラーを成形することにより、ユニフォミティを改善できることがわかる。

From Table 3, it can be seen that the uniformity can be improved by forming the bead filler by gradually decreasing the winding tension of the strip material toward the radially outer side.

5 Bead core 6 Bead filler (tire component)
6A Body part 6B Rubber part 13 Unvulcanized rubber layer 33 Mold R Rubber strip material (unvulcanized rubber material)
S Strip material

Claims (6)

When forming a green tire having a tire constituent member in which a strip material made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending a thermoplastic resin component and an elastomer component is wound in the tire circumferential direction, the strip is preliminarily formed. The green tire is formed by attaching the tire component formed by winding the strip material while reducing the tension applied to the portion positioned on the outer side in the tire radial direction. A method of manufacturing a pneumatic tire , characterized by : The tire constituent member includes a main body portion having a structure in which the strip material is laminated in a tire radial direction and a rubber portion disposed on an outer peripheral side of the main body portion, and the rubber portion is not added after the main body portion is molded. The method for producing a pneumatic tire according to claim 1 , wherein the pneumatic tire is molded from a vulcanized rubber material. The method for manufacturing a pneumatic tire according to claim 1 or 2 , wherein the shape of the tire constituent member is adjusted before the tire constituent member is attached. The method for manufacturing a pneumatic tire according to claim 3 , wherein the tire constituent member is heated while adjusting the shape of the tire constituent member. Before mounting the tire component, the manufacturing method of the pneumatic tire according to any one of claims 1 to 4, characterized in that covering the tire component member in the unvulcanized rubber layer. A pneumatic tire characterized by being manufactured by the manufacturing method of the pneumatic tire according to any one of claims 1 to 5.

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