JP2005313690A - Run-flat tire supporting element, manufacturing method thereof, and run-flat tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a run-flat tire supporting element capable of obtaining stable fitting strength with a rim, and being easily and securely installed and fixed to the rim even if the outer diameter of the supporting element installing portion of the rim and the inner diameter of the rim installation surface of the run-flat tire supporting element do not match with high precision; a manufacturing method thereof; and a run-flat tire installed and fixed with the supporting element. <P>SOLUTION: The annular run-flat supporting element 12 installed to the rim 11 comprises a base material portion 16 structured of a closed-cell resin foam element, a non-foam resin portion 17 provided on the outer peripheral side of the base material portion 16, and a reinforcing portion provided on the inner peripheral surface side of the base material portion 16. The reinforcing portion 18 is composed of a resin layer 19, and a cord layer 20 formed in the resin layer 19 and made of a cord material wound in a tire circumferential direction. On the inner peripheral surface of the resin layer 19, a recessed groove 22 extending in a direction intersecting the tire circumferential direction is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a run-flat tire support that is mounted on a rim of a pneumatic tire for an automobile, maintains a tire outer diameter necessary when the tire is punctured, and can run safely, a method for manufacturing the same, and the run The present invention relates to a run flat tire to which a flat tire support is mounted and fixed.

  A run-flat tire has a vehicle load and a load until it reaches the nearest service facility when the tire is punctured or when the tire pressure is greatly reduced or zero (run-flat state). It is a tire with durability that can withstand running. As a run-flat tire, a side-reinforcement type in which the side portion of the tire is reinforced and a core type in which a run-flat tire support body (hereinafter sometimes simply referred to as a support body) is disposed inside the tire are practical. It has become.

  As an example of the core type, Patent Document 1 below discloses a run flat tire support made of a flexible elastomer. The support body is directly fixed to the rim in the same manner as the tire because it receives the load of the vehicle directly in the run in the run-flat state (run-flat run) and receives the action of centrifugal force in the normal run. Is required. Therefore, in the vicinity of the rim contact surface of the support body, a reinforcing portion having a flat inner peripheral surface and cord reinforcement is provided.

Similarly to the above, the run-flat tire support disclosed in the following Patent Document 2 is also provided with a reinforcing portion with cord reinforcement in the vicinity of the rim contact surface. The reinforcing portion has a flat inner peripheral surface, and FIG. As shown in FIGS. 6 to 9, a plurality of cord materials are supplied to a cylindrical mandrel to form a bias cord layer and a radial cord layer. A curable resin is attached to the supplied cord material by an applicator as required, and the resin and the cord material are combined.
Japanese Patent Laid-Open No. 10-6721 US 2003/0000623 A1

  However, the support described in Patent Document 1 includes a pre-molded cord layer and a highly rigid reinforcing portion that is formed integrally with the support and has a flat inner peripheral surface. The inner surface of the rim mounting surface of the support (hereinafter simply referred to as the support inner diameter) is slightly larger than the outer diameter of the support mounting portion of the rim (hereinafter simply referred to as the rim outer diameter). There is a problem that the fixing force between the rim and the rim is reduced. On the other hand, if the inner diameter of the support is slightly smaller than the outer diameter of the rim, it is difficult to mount the support on the rim. Therefore, the inner diameter of the support and the outer diameter of the rim need to coincide with each other with high accuracy, but it is very difficult in consideration of variations due to curing shrinkage and the like during the manufacture of the support. In the technique disclosed in Patent Document 2, basically, only a support having a cylindrical surface with a flat inner surface can be obtained, which has the same problem as described above.

  The present invention has been made in view of such circumstances, and the object thereof is to obtain a stable fitting strength with a rim, an outer diameter of a rim support mounting portion, and a rim mounting of a run-flat tire support. Run-flat tire support capable of being easily mounted and fixed to the rim even if the inner diameter of the surface does not coincide with high accuracy, a method for manufacturing the same, and a run-flat tire mounted with the run-flat tire support Is to provide.

  The above object can be achieved by a run flat tire support as described below. That is, the run-flat tire support of the present invention is an annular run-flat tire support that is mounted on a rim in a run-flat tire, and includes a base material portion made of closed-cell resin foam, and the base material A non-foamed resin portion provided on the outer peripheral surface side of the portion and a reinforcing portion provided on the inner peripheral surface side of the base material portion, and the reinforcing portion is formed in the resin layer and the resin layer In addition, a cord layer made of a cord material wound in the tire circumferential direction is formed, and a concave groove extending in a direction crossing the tire circumferential direction is formed on the inner circumferential surface of the resin layer.

  According to the run-flat tire support body having such a configuration, the tire can be supported from the inner surface while receiving the load of the vehicle in the run-flat state, and run-flat traveling is possible. In addition, since the support has the reinforcing portion including the cord layer on the rim mounting side, deformation due to centrifugal force during normal traveling is suppressed, and stable fitting strength with the rim can be obtained. Furthermore, the inner diameter of the support is easily increased by forming a concave groove extending in a direction intersecting the tire circumferential direction on the inner circumferential surface of the resin layer of the reinforcing portion. As a result, the support body can be easily mounted and fixed to the rim even if the outer diameter of the support mounting portion of the rim and the inner diameter of the rim mounting surface of the support do not coincide with each other with high accuracy. Moreover, it can contribute to the weight reduction of a support body by forming a ditch | groove.

  In the run flat tire support described above, it is preferable that a plurality of the concave grooves are formed at a predetermined pitch in the tire circumferential direction while extending in the width direction of the reinforcing layer.

  According to the run-flat tire support body having such a configuration, the inner diameter of the support body can be easily expanded uniformly in the tire circumferential direction, and the support body can be mounted and fixed to the rim more easily.

  In the above-mentioned run flat tire support, it is preferable that the closed cell resin foam constituting the base portion is a closed cell polyurethane resin foam.

  By constituting the base material portion with a closed-cell polyurethane resin foam, a run-flat tire support that is lighter than the conventional and excellent in strength and durability can be formed.

  The run-flat tire support manufacturing method of the present invention is a method for manufacturing an annular run-flat tire support mounted on a rim in a run-flat tire, wherein the run-flat tire support is a closed cell resin foam. A base part composed of a body, a non-foamed resin part provided on the outer peripheral side of the base part, and a reinforcing part provided on the inner peripheral side of the base part The reinforcing portion forming step has a convex portion extending in a direction intersecting with the tire circumferential direction on the outer peripheral surface, and the cord material is formed on the outer peripheral surface of the middle size forming the rim mounting surface of the run-flat tire support. A cord layer forming step of winding in a circumferential direction; and a resin layer forming step of forming a resin layer by supplying a resin forming material to a cord layer constituted by the wound cord material.

  According to the method for manufacturing the run-flat tire support, the cord material constituting the cord layer is wound around the middle mold via the outer peripheral surface of the convex portion, and the resin layer is supplied to the cord layer. While forming the cord layer therein, the groove corresponding to the convex portion can be formed on the inner peripheral surface of the resin layer. This makes it possible to manufacture a support body whose inner diameter is easy to expand, and the support body even if the outer diameter of the support mounting portion of the rim and the inner diameter of the rim mounting surface of the support do not coincide with each other with high accuracy. Can be easily and firmly attached and fixed to the rim.

  Moreover, the run flat tire of the present invention is characterized in that the run flat tire support described above is mounted.

  Such a run-flat tire is suitable because the support is firmly mounted and fixed to the rim even if the outer diameter of the support mounting portion of the rim and the inner diameter of the rim mounting surface of the support do not match with high accuracy. is there.

  In the run flat tire described above, at least one of the tire inner surface and the run flat tire support outer peripheral surface, the rubber material constituting the tire inner surface and the material constituting the outer peripheral surface of the run flat tire support are both. It is preferable that a low swelling lubricant is applied.

  By applying the lubricant, the travel distance in the run-flat state can be further increased. Here, the low swelling property means that the degree of swelling is small and the degree of swelling does not cause a decrease in material strength, and it is preferable not to swell.

  In the above-described run flat tire, when the run flat tire support is fitted to the rim, the belt-shaped fixing member is interposed as a spacer between the rim and the support to cure the run flat tire support. This is a preferred embodiment because stable mounting and fixing are possible even if there is variation in the inner diameter due to shrinkage.

(Constituent material of run-flat tire support)
As described in detail later, the run-flat tire support of the present invention includes a base material portion, a non-foamed resin portion provided on the outer peripheral surface side of the base material portion, and an inner peripheral surface side of the base material portion. It is comprised by the reinforcement part provided in. Hereinafter, these constituent materials will be described.

  A base material part is comprised with the closed-cell resin foam (Hereafter, it may abbreviate as a resin foam only.), And a resin foam can be manufactured by a well-known method. Specifically, a chemical foaming agent that decomposes by heating to generate a gas or a foaming agent that vaporizes to form a foam is added to a resin or a resin forming raw material and heated to form a foam of a predetermined shape Examples thereof include a molding method in which a resin-forming raw material is made into a foam (bubble dispersion) by stirring with a foaming agent or a non-reactive gas and then cured into a predetermined shape.

  The resin foam can be used without limitation as long as it has the characteristics required as a support, but in consideration of flexibility and elasticity, all are vulcanized rubbers that are thermosetting materials. Use of a foam or a polyurethane resin foam is preferred.

  Preferred examples of the rubber material constituting the vulcanized rubber foam include natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene propylene rubber, chloroprene rubber, and millable urethane rubber.

  In addition to foaming agents, vulcanization accelerators, and vulcanizing agents, vulcanized rubber foams include reinforcing agents such as carbon black and silica, process oils, plasticizers, processing aids, fillers, and aging as necessary. A known rubber additive such as an inhibitor is added. The vulcanized rubber foam can be processed and molded into a predetermined shape by a conventional method. That is, rubber material, carbon black, process oil, etc. are kneaded with a Banbury mixer etc. to make a master batch, and a foaming agent, a vulcanizing agent and a vulcanization accelerator are added to the master batch after cooling, and then kneaded with a kneader. A reactive rubber composition. The reactive rubber composition is supplied to a mold having a predetermined shape and heated to foam and cure to form the base portion of the run-flat tire support.

  As a foaming agent for producing a vulcanized rubber foam, a known chemical foaming agent that is a compound that decomposes by heating to generate gas is used. Specifically, inorganic foaming agents such as sodium bicarbonate and ammonium bicarbonate, nitroso compounds such as N, N′-dinitrosopentamethylenetetramine, azo compounds such as azodicarbonamide and azobisisobutyronitrile, benzene Examples include sulfonyl hydrazides such as sulfonyl hydrazide and toluenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, and the like. It is also suitable to use salicylic acid, urea and a foaming aid containing these together with these foaming agents.

  On the other hand, the polyurethane resin foam is composed of hollow spherical particles and a polyurethane elastic body, or is composed of a polyurethane elastic body foamed with a foaming agent. The polyurethane elastic body can be made into a foam by using a known polyurethane elastic body forming raw material, and all of them are known to form a polyurethane elastic body using a polyol compound, polyisocyanate compound and chain extender known in the technical field of polyurethane elastic bodies. Used as a raw material (see: Keiji Iwata, "Polyurethane Resin Handbook", Nikkan Kogyo Shimbun; issued on September 25, 1987).

Polyurethane resin foams can be manufactured by the one-shot method and the prepolymer method, and either method may be adopted, but even if the same raw material is used, an elastic body excellent in physical properties such as mechanical strength is obtained. Therefore, the prepolymer method is preferable. The following method is illustrated as a manufacturing method of a polyurethane resin foam.
(1) A prepolymer or a mixture of a prepolymer and a chain extender is stirred to entrain a non-reactive gas to obtain a meringue-like cell dispersion, and in the case of a prepolymer, a chain extender is further added and mixed. In the case of a mixture of a prepolymer and a chain extender, a method in which the mixture is directly supplied into a predetermined mold and subjected to reaction curing.
(2) A method in which a foaming agent is added to a liquid polyurethane elastic body constituting raw material composition and supplied into a mold, and the foaming agent is vaporized and cured simultaneously with the reaction.
(3) A method in which hollow spherical particles are added to and dispersed in a liquid polyurethane elastic body constituting raw material composition and supplied into a mold to be cured.

  According to the manufacturing method of (1), there is an effect that a base material portion having a uniform cell diameter and density can be obtained. As the non-reactive gas, it is preferable to use air because the shape stability is good. In forming the cell dispersion, it is preferable to add a foam stabilizer known in the technical field of polyurethane foam to 0.5 to 20% by weight, preferably 1 to 10% by weight, based on the total amount of the polyurethane resin. .

  In the production method (2), examples of the foaming agent include pentane, a fluoroalkyl compound, and water. Water itself does not vaporize, but carbon dioxide gas generated by reacting with an isocyanate group becomes a foaming agent. In the production of a polyurethane resin foam, it is preferable to use a foam stabilizer because uniform and fine bubbles are formed.

  In the production method (3), the hollow spherical particles are preferably hollow thermoplastic resin balloons. Such a hollow thermoplastic resin balloon is obtained, for example, by using a thermoplastic resin such as polyacrylonitrile or polyvinylidene chloride and heating a microcapsule containing an organic solvent such as hydrocarbon inside. Examples of commercially available products include EXPANSEL (manufactured by Nippon Philite), Micropearl (manufactured by Matsumoto Yushi Co., Ltd.), and the like.

  The polyurethane resin foam is preferably a closed-cell polyurethane resin foam having an average cell diameter of 20 to 200 μm. The polyurethane resin foam is particularly lightweight among the closed cell resin foams and is excellent in mechanical strength, elasticity, and the like.

Since the resin foam which comprises a base material part can achieve weight reduction as the whole run flat tire, it is preferable that a density is 0.3-0.9 g / cm < ³ >. When this density is less than 0.3 g / cm ³ , the mechanical strength may be lowered, and when it exceeds 0.9 g / cm ³ , the lightening effect is not sufficient. In the above, it is more preferable that the density of the resin foam is 0.4 to 0.7 g / cm ³ in terms of an excellent balance between strength and weight reduction. Moreover, it is preferable that the resin foam which comprises a base material part is a foaming elastic body whose 5% offset stress is 0.3-3 Mpa. If the 5% offset stress of the resin foam is less than 0.3 MPa, the durability during run-flat running is not sufficient, and if it exceeds 3 MPa, it becomes too hard and difficult to attach to the rim. This causes a problem that vibration during driving increases. The offset stress is obtained by a compression test (refer to pages 71 to 72 of “Plastic Test Handbook” (Nikkan Kogyo Shimbun Co., Ltd.) edited by Plastic Standard Test Method Research Group).

  Next, the non-foamed resin portion provided on the outer peripheral surface side of the base material portion will be described. The non-foamed resin forming the non-foamed resin part can be used without limitation as long as the material having the necessary flexibility, strength, etc., may be a resin material different from the base material part, and may be the same resin material. Also good. Specific examples include polyester resins such as polyethylene terephthalate and polybutylene naphthalate, polyamide resins such as nylon 6 and nylon 66, polyurethane resins, fluorine resins such as PFA and ETFA, polycarbonate resins, and polyacetal resins. In addition, use of the same reaction-curable polyurethane resin as the reinforcement part mentioned later is preferable.

Examples of the method of laminating the non-foamed resin portion on the outer peripheral side of the base material portion include the following methods.
(1) A method in which a non-foamed resin part member is molded with a non-foamed resin, and the non-foamed resin part member and a preformed base material part are bonded with an adhesive.
(2) A method in which a non-foamed resin part member is formed using a non-foamed resin as a cylindrical heat-shrinkable film, and an adhesive is applied to the outer peripheral surface of a preformed base material part, followed by heat shrinkage and adhesive lamination.
(3) A method in which a pre-molded non-foamed resin part member is disposed in a mold, and a resin foam-forming raw material is injected and cured to form a base part and simultaneously adhere to the non-foamed resin part member.
(4) A non-foamed resin part molding cavity is formed by a molding die on the outer peripheral surface side of the preformed base part, and a non-foamed resin part constituting material is injected into the cavity to form a non-foamed resin part. Method.

  In the above, when the non-foamed resin part member is molded in advance, the inner surface (adhesion surface) of the corona discharge treatment, plasma treatment, blast treatment or the like according to the constituent resin is used to increase the adhesion strength. Processing is a preferred embodiment.

  Next, the reinforcement part provided in the inner peripheral surface side of a base material part is demonstrated. The reinforcing portion according to the present invention includes a resin layer and a cord layer formed in the resin layer and made of a cord material wound in the tire circumferential direction.

  As the cord material constituting the cord layer, known cords can be used without limitation. Examples include rayon cords, polyamide cords such as nylon-6,6, polyester cords such as polyethylene terephthalate, aramid cords, glass fiber cords, Kevlar fiber cords, carbon fibers, steel cords, etc. One or two of these Used in combinations of more than one species.

  The resin layer may be composed of a foamed resin or may be composed of a non-foamed resin. When the resin layer is composed of a foamed resin, the foamed resin is preferably a foamed resin material (resin foam) that constitutes the base material portion. Thereby, a resin layer and a base material part can be manufactured efficiently. The resin foam is as described above.

  When the resin layer is composed of a non-foamed resin, the non-foamed resin preferably has a 100% elongation modulus of 2 to 20 MPa. When the 100% elongation modulus of the non-foamed resin is less than 2 MPa, the resin (elastic body) may be too soft and the fixing force with the rim may not be sufficient. On the other hand, if it exceeds 20 MPa, it is too hard, and when the support inner diameter is smaller than the rim outer diameter due to manufacturing variations including shrinkage and the like, it may be difficult to fit the rim as the reinforcing portion according to the present invention. is there.

  Moreover, it is preferable that the non-foamed resin constituting the resin layer is a non-foamed body of a resin material constituting the base portion. Thereby, the adhesive strength of a base material part and a reinforcement part improves. As the non-foamed resin, it is preferable to use an elastic epoxy resin or a curable polyurethane resin, and the use of a polyurethane resin is more preferable in terms of excellent durability against dynamic deformation and mechanical strength. The polyurethane resin can be produced by a one-shot method and a prepolymer method, and the prepolymer method is preferred for the reasons described above. The polyurethane resin is formed, for example, by mixing an isocyanate component such as an isocyanate prepolymer and an active hydrogen group-containing component into a curable composition and curing it. In addition, it is preferable that a bubble is not contained in the reinforcement part.

(Configuration of run-flat tire support and run-flat tire)
Next, the configuration of the run flat tire support and the run flat tire will be described. FIG. 1 is a cross-sectional perspective view illustrating the structure of a run-flat tire of the present invention. FIG. 2 is a perspective view illustrating a run-flat tire support. 3 is a cross-sectional view taken along line YY of FIG. FIG. 4 is a side view of the run-flat tire support.

  The run flat tire 10 includes a tire 9 attached and fixed to a rim 11 and an annular run flat tire support 12. In this embodiment, the rim 11 is an integrated rim in which the bead 13 side on the right side in FIG. 1 is formed to be equal to or smaller than the inner diameter of the support 12 in consideration of the mounting of the support 12, and the tire 9 has an asymmetric cross-sectional shape. Have. The run flat tire support 12 has a rectangular cross section, and is externally fitted to the central flat portion 14 of the rim 11. The cross-sectional shape of the support 12 is not particularly limited, but it is preferably a flat shape with a longer tire width direction in consideration of stability during run-flat running.

  The support 12 is provided on the base 16 made of closed cell resin foam, the non-foamed resin 17 provided on the outer peripheral surface of the base 16, and the inner peripheral side of the base 16. The reinforcement part 18 is comprised. Further, the reinforcing portion 18 includes a non-foamed resin layer 19 (corresponding to the resin layer) and a cord layer 20 formed in the non-foamed resin layer 19. The cord layer 20 is made of a cord material 21 wound in the tire circumferential direction, and prevents the support 12 from being lifted from the rim 11 by a centrifugal force acting during normal running.

  The thickness of the non-foamed resin portion 17 is not particularly limited as long as the necessary travel distance in the run-flat state is ensured, but is preferably 0.01 to 3 mm. If the thickness of the non-foamed resin portion 17 is less than 0.01 mm, the base material portion 16 slides on the tire inner surface 15 with slight wear, which is not preferable. Moreover, when the said thickness exceeds 3 mm, the weight reduction of the support body 12 will be inhibited. The non-foamed resin portion 17 is provided on a surface that contacts the tire inner surface 15 during run-flat travel, but may be formed to extend to the side portion of the base material portion 16 for safety. Moreover, you may provide a thin groove in the outer peripheral surface of the non-foaming resin part 17 for weight reduction.

  Concave grooves 22 extending in the width direction of the reinforcing portion 18 are formed on the inner peripheral surface of the non-foamed resin layer 19, and in the present embodiment, eight concave grooves 22 are formed at a predetermined pitch in the tire circumferential direction. Has been. As a result, the inner diameter of the support 12 can be easily increased and can be easily mounted on the rim 11. The groove 22 only needs to extend in a direction intersecting the tire circumferential direction. For example, the groove 22 may extend in a direction inclined with respect to the width direction of the reinforcing portion 18 or may extend in a V shape in plan view. .

  The shape of the concave groove 22 is not particularly limited, but it is preferable that the upper side and the lower side as shown in FIG. 4 are substantially trapezoidal in a side view along the circumferential direction. Thereby, durability at the time of run-flat traveling is suitably secured. Furthermore, it is preferable that the corner portion 25 formed on the inner surface and the opening edge of the concave groove 22 is subjected to R processing or chamfering processing. For example, it is preferable that each corner portion 25 is R0.1 to R0.5 with respect to the concave groove 22 having a depth of 1 mm. Thereby, it is possible to prevent stress concentration when the support 12 is subjected to compressive deformation during run-flat travel, and to suppress the occurrence of cracks in the corner portion 25.

  The dimensions (depth, circumferential length L) and the number of formed grooves 22 are such that the effect of expanding the inner diameter of the support 12 can be suitably obtained, and the durability during run-flat running can be ensured. If it is, it will not specifically limit, but the depth of the ditch | groove 22 is what is 0.5-3 mm. When the depth is less than 0.5 mm, the weight of the support 12 becomes relatively heavy, the effect of expanding the inner diameter of the support 12 is small, and the effect of improving the wearability is small. On the other hand, if it exceeds 3 mm, the durability of the support 12 during run-flat running may be impaired.

  The run-flat tire support 12 of the present invention preferably has a plurality of concave portions 23 and 24 formed on the side surface portion of the base material portion 16. Thereby, the run flat tire 10 can be further reduced in weight while ensuring the strength necessary for the run flat tire support 12.

  FIG. 5 is a diagram illustrating the arrangement of the recesses 23 and 24 formed on the side portion of the support 12 in a top view and a side view, respectively. FIG. 5A is an example in which the recesses 23 and 24 are alternately arranged so as not to overlap in a side view, and corresponds to FIGS. FIG. 5B shows an example in which the recesses 23 and 24 are arranged at the same circumferential position. The support 12 in FIG. 5B has a larger volume ratio of the recesses 23 and 24 than that in FIG. In the example of FIG. 5, the recesses 23 and 24 have a rectangular cross-sectional shape in the radial direction, but the shape and number of the recesses 23 and 24 are particularly limited as long as the support 12 satisfies a predetermined mechanical strength requirement. For example, a half-oval shape may be used.

  The run-flat tire of the present invention is configured on at least one of the tire inner surface 15 and the outer peripheral surface of the run-flat tire support 12 (the outer peripheral surface of the non-foamed resin portion 17) that contacts the tire inner surface 15 during run-flat travel. Any of the materials is preferably coated with a lubricant having low swellability. Examples of such lubricants include glycerin and polyglycerin as suitable materials.

  As another form of the run flat tire support of the present invention, the reinforcing portion 18 includes a resin layer, a fiber layer formed in the resin layer, and a cord wound around the outer periphery of the fiber layer in the tire circumferential direction. What comprises the cord layer 20 made of the material 21 is preferable.

  The fiber layer is preferably composed of a woven fabric or a net. As a material constituting the fiber layer, a known fiber material can be used without limitation. Examples include rayon, polyamide fibers such as nylon-6, 6, polyester fibers such as polyethylene terephthalate, aramid fibers, glass fibers, and the like. The fiber layer may be wound by cutting the base fabric into a necessary width and length, or may be wound in a tape shape narrower than the width of the support 12. It is preferable that the fiber layer is wound without applying a large tension, such as simply by hand. These fiber materials are preferably used after being subjected to an adhesion treatment for improving the adhesion to the resin layer.

  When the run-flat tire support has a different diameter portion at the rim mounting portion, when the cord material 21 is wound around the middle mold having an outer peripheral surface along the different diameter portion in the manufacture of the support, There is a problem that the cord material 21 slips, the cord interval does not become as set, and the fitting strength with the rim 11 varies. However, according to the configuration including the fiber layer, the cord material 21 is wound after the fiber is wound around the middle mold, so that the fiber layer exhibits an anti-slip action. That is, as compared with the case where the cord material 21 is directly wound around the middle mold, the movement of the cord material 21 due to the slip of the mold surface is suppressed, and the cord spacing is as set and the fitting strength with the rim 11 is stabilized. Is played.

(Method for producing run-flat tire support)
Next, an example of a method for manufacturing a run-flat tire support will be described. FIG. 6 is a diagram illustrating an example of an apparatus for forming the reinforcing portion. FIG. 7 is an enlarged side view of the code layer immediately after formation.

  First, an intermediate mold 30 (mold part) that forms the rim mounting surface of the run-flat tire support 12, that is, the inner peripheral surface of the reinforcing part 18 is prepared. The middle mold 30 shown in FIG. 6 includes a rotation shaft 31 and a mold holding member 32 and is configured to be rotatable about the rotation shaft 31. Convex portions 33 are formed on the outer peripheral surface of the middle mold 30, and in the present embodiment, eight convex portions 33 extend in the width direction of the reinforcing portion 18. The convex portion 33 has a substantially trapezoidal shape in a side view in which each corner portion is R-processed, and is provided so as to correspond to the concave groove 22 formed on the inner peripheral surface of the reinforcing portion 18.

  A cord material 21 constituting the cord layer 20 is wound around the original fabric bobbin 34. The cord material 21 is supplied through a tension load device 35 so as to have a predetermined tension. It is wound around the outer peripheral surface (corresponding to the code layer forming step). Here, the predetermined tension is preferably 5 to 50 N (about 0.5 to 5 kgf). If the tension is less than 5N, the uniformity of the code arrangement may be reduced, or the fixing force for fitting with the rim 11 may not be sufficiently exhibited. On the other hand, when the tension exceeds 50 N, the rim 11 may not be mounted depending on the variation in the inner diameter of the support 12. However, when the cord material 21 is a steel cord, the tension may be less than 5N.

  As shown in FIG. 7, the cord material 21 is stretched over the convex portion 33, and a space 36 is formed between the convex portions 33 on the inner peripheral side of the cord layer 20. An outer die (not shown) for forming the reinforcing portion is disposed on the outer peripheral side of the middle die 30, and a raw material for forming the non-foamed resin layer 19 is injected into the outer die and cured by reaction (in the resin layer forming step). Equivalent to.). The raw material for forming the non-foamed resin layer 19 is also injected into a space 36 provided on the inner peripheral side of the arranged cord material 21 (code layer 20), and substantially encloses the code layer 20 to form the non-foamed resin layer 19. The concave groove 22 is formed along the convex portion 33 while being formed.

  As described above, the size and the number of grooves 22 formed are not particularly limited, but can be set as appropriate in consideration of the formation process of the code layer 20, the workability of the middle mold 30, and the like. That is, if the height of the convex portion 33 is too high or the number is too large, the processing of the middle mold 30 becomes complicated, which is not preferable. On the other hand, if the height of the convex portion 33 is too low or the number is too small, the cord material 21 wound around the middle mold 30 comes into contact with the outer peripheral surface of the middle mold 30 between the convex portions 33, and the space 36 is appropriate. It is not preferable because it is not formed. The circumferential length L of the concave groove 22 can be appropriately set according to the number of formed grooves, and examples thereof are those that are 1/32 to 1/8 of the inner circumference of the support 12. Examples of the number of the concave grooves 22 include 4 to 16.

  The base portion 16 and the non-foamed resin portion 17 are bonded to the formed reinforcing portion 18 to constitute the run flat tire support 12. The adhesive between the reinforcing portion 18 and the base material portion 16 is a resin foam that forms the base material portion 16 by arranging the formed reinforcing portion 18 in a molding die for forming the base material portion without removing from the intermediate mold 30. By injecting the forming raw material and curing the resin foam, the base portion 16 can be molded and bonded to the reinforcing portion 18 at the same time. Or the member used as the base material part 16 is shape | molded previously, the code | cord layer 20 formed in the member and the middle mold | type 30 is arrange | positioned in the said shaping | molding die, the formation raw material of the non-foamed resin layer 19 is inject | poured, and it is made to cure. The method may be used. Alternatively, a method of forming the base member 16 by separately forming a member to be the reinforcing portion 18 and disposing the member on the mold.

(Example)
<1> Production of Reinforcing Section A medium mold (outer diameter 420 mm, width 110 mm) of a support molding die was prepared. Eight convex portions extending in the width direction of the reinforcing portion are provided at equal intervals in the tire circumferential direction on the outer peripheral surface of the middle size, and the side view shape of the convex portion is a width dimension (lower side) of 82.4 mm, an upper side of 83.2 mm, a high It was a substantially trapezoid with a thickness of 2.0 mm. A net (corresponding to the fiber layer) part number KS5431 (manufactured by Kanebo) formed of glass fiber is wrapped around the outer periphery of the medium mold twice, and then an aramid cord (KEVLAR: Toray) with 3300 dtex and fiber diameter of 0.6 mm is used. -Corresponding to the cord material made by DuPont) was wound in one layer at a tension of 30 N spirally along the tire circumferential direction so that the number of ends was 10 / inch. Both ends were fixed to notches formed in the middle mold.

  60.5 g of MOCA (Ihara Chemical Co.) dissolved at 120 ° C. was added to 500 g of adiprene L-100 (Uni Royal Co.), which is an isocyanate group-terminated prepolymer heated to 80 ° C., and mixed and stirred, followed by vacuum desorption. It foamed and it was set as the non-foaming resin layer forming raw material.

  The middle mold on which the code layer was formed was placed in a mold constituting a reinforcing part mold using a plurality of outer molds (inner diameter 426 mm, width 110 mm) and heated to 100 ° C. And the said non-foamed resin layer forming raw material was inject | poured into the cylindrical cavity which a reinforcement part shaping | molding die has, and it hardened at 100 degreeC for 1 hour, and produced the reinforcement part.

<2> Production of base material part The reinforcing part produced in the above <1> is attached to the inner cylinder of the base material part molding die having a cylindrical cavity having an outer diameter of 510 mm and a depth of 110 mm, together with the middle mold, Heated.

  5000 g of adiprene L-100 is heated to 80 ° C., 150 g of silicon foam stabilizer SH-192 (Toray Dow Corning Silicone) is added, and the mixture is stirred in air using a biaxial stirrer in a 20 L container, The mixture was stirred until the volume of the liquid became twice the original volume to obtain a meringue bubble dispersion. After adjusting the temperature of this bubble dispersion to 50 ° C., 605 g of MOCA dissolved at 120 ° C. was added and mixed uniformly to obtain a resin foam forming raw material.

The obtained resin foam-forming raw material is poured into a cylindrical cavity of a base part mold (outer diameter 510 mm, height 110 mm) and cured by heating at 100 ° C. for 1 hour to have a reinforcing part. Was made. The density of the closed cell polyurethane resin foam constituting the base material portion was 0.6 g / cm ³ , and the 5% offset stress was 2.0 MPa.

<3> Production of non-foamed resin part After the base part produced in the above <2> is hardened so as to be removable, the mold part forming the outer peripheral surface is removed, and the width of the base part is 2 mm on the outer circumference. An outer mold capable of forming a cavity was disposed. The same non-foamed resin-forming raw material as used in <1> above was injected into this cavity and cured at 100 ° C. for 1 hour. The support made of the obtained reinforcing part, base material part, and non-foamed resin layer was post-cured at 120 ° C. for 8 hours to obtain a run-flat tire support. The inner diameter of the run-flat tire support after cooling was 417.5 mm. Ten evaluation samples were prepared for evaluation of rim mounting properties and mounting stability.

(Comparative example)
A run-flat tire support was produced in the same manner as in the example except that a medium-sized mold having no protrusions on the outer peripheral surface was used. That is, a support body having no groove on the inner peripheral surface was prepared, and ten evaluation samples were prepared in the same manner as in the examples.

(Assembly of run-flat tires)
Using a split rim having an outer diameter of the support mounting portion of 418 mm, a run flat tire was assembled using the mounting device shown in FIG. First, the run-flat tire support 12 is pushed into the inside of the tire 9, and the first rim member 60 on which the support 12 is fitted is placed on the fixed base 64. Next, the mounting jig 62 having a protrusion 61 that moves into the upper surface side of the tire 9 and presses the support 12 is pushed in the direction of the fixed base 64 by the air cylinder 63. As a result, the support 12 is attached to the first rim member 60. Furthermore, the assembly of the run-flat tire is completed by fixing the second rim member (not shown) of the split rim to the first rim member 60 with bolts.

(Evaluation)
1) Ease of assembly The wearability when a run-flat tire was assembled according to the above procedure was evaluated. As a result, the 10 samples of the example had a larger inner diameter of the support when mounted on the rim, and could be mounted smoothly and easily. Compared to the sample of the example, it was difficult to attach to the rim.

2) Rim mounting stability The run flat tires obtained in the examples and comparative examples were rotated for 30 minutes at a rotation speed corresponding to 100 km / h. After the rotation test, it was visually evaluated whether or not the run-flat tire support was displaced from the initial position. No displacement of the rim in the axial direction was observed in any of the samples. That is, it was found that in the example, even if the concave groove is formed on the inner peripheral surface of the support, it is stably fixed.

Sectional perspective view illustrating the structure of the run-flat tire of the present invention A perspective view illustrating a run-flat tire support YY sectional view in FIG. Side view illustrating run-flat tire support The figure which illustrated arrangement | positioning of the recessed part formed in the side part of a run flat tire support body The perspective view which illustrates the device for forming a reinforcement part Enlarged side view of the code layer immediately after formation Schematic sectional view illustrating the assembly process of run-flat tires

Explanation of symbols

9 Tire 10 Run-flat tire 11 Rim 12 Run-flat tire support 16 Base part 17 Non-foamed resin part 18 Reinforced part 19 Non-foamed resin layer 20 Cord layer 21 Cord material 22 Concave groove 25 Corner part 30 Medium size 33 Convex part 36 Space

Claims (6)

An annular run flat tire support attached to a rim in a run flat tire,
A base part composed of closed cell resin foam, a non-foamed resin part provided on the outer peripheral surface side of the base part, and a reinforcing part provided on the inner peripheral surface side of the base part Have
The reinforcing portion is composed of a resin layer and a cord layer formed in the resin layer and made of a cord material wound in the tire circumferential direction,
A run-flat tire support, wherein a concave groove extending in a direction crossing the tire circumferential direction is formed on an inner circumferential surface of the resin layer.   The run-flat tire support according to claim 1, wherein a plurality of the concave grooves extend in the width direction of the reinforcing layer and are formed at a predetermined pitch in the tire circumferential direction.   The run-flat tire support according to claim 1 or 2, wherein the closed-cell resin foam constituting the base portion is a closed-cell polyurethane resin foam. A method of manufacturing an annular run flat tire support to be mounted on a rim in a run flat tire,
The run-flat tire support includes a base material portion formed of a closed cell resin foam, a non-foamed resin portion provided on the outer peripheral surface side of the base material portion, and an inner peripheral surface side of the base material portion. And a reinforcing portion provided in
The step of forming the reinforcing part includes
A cord layer formed by winding a cord material in the tire circumferential direction on the outer circumferential surface of a middle size having a convex portion extending in a direction intersecting with the tire circumferential direction on the outer circumferential surface and forming a rim mounting surface of the run flat tire support Process,
A method for producing a run-flat tire support, comprising: a resin layer forming step of supplying a resin forming material to a cord layer constituted by the wound cord material to form a resin layer.   A run flat tire equipped with the run flat tire support according to claim 1.   At least one of the tire inner surface and the outer peripheral surface of the run-flat tire support is provided with a low-swelling lubricant for both the rubber material constituting the tire inner surface and the material constituting the outer surface of the run-flat tire support. The run-flat tire according to claim 5, which is applied.

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