JP4612979B2 - Solid tire manufacturing method and casting mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a solid tire and a casting mold.
[0002]
[Prior art]
When producing a solid tire by filling an elastic resin material inside a normal rubber tire, a casting method is known in which a cylindrical casting mold is fitted into the tire casing and the inside of the sealed tire casing is filled. ing.
[0003]
The casting mold used at this time is provided with flanges (flange) at both ends of the cylindrical body in order to prevent the bead portion of the tire casing from being excessively swollen outward and deformed by the filling pressure or foaming pressure of the elastic resin. ) And supporting the bead portion from the outside to suppress excessive deformation. It is preferable that the cylindrical main body of the casting mold is entirely or partially formed into a conical shape to improve the demoldability.
[0004]
Further, as the elastic resin filled in the tire casing, it is considered that an elastic resin such as foamed rubbers or soft urethane foam can provide a solid tire having good cushioning properties and durability.
[0005]
[Problems to be solved by the invention]
However, when the above-described conventional solid tire manufacturing method or casting mold is adopted, the casting mold is pressed against the inner peripheral surface of the completed solid tire, and it is not easy to remove the mold. There was a problem that the product cracked.
[0006]
In order to prevent such a problem from occurring, a part or the whole of the inner peripheral surface of the casting mold main body is formed in a conical shape instead of the conventional cylindrical shape to disperse the pressure contact force in the axial direction. In this case, as shown in FIG. 5, the elastic resin P filled in the tire casing of the completed solid tire forms a tapered surface 30 and a stepped portion 31 on the inner peripheral surface. When the solid tire is mounted on the body portion 32 of the hood, there is a problem that it becomes difficult to attach the front end of the body portion 32 to the stepped portion 31 or the tapered surface 30.
[0007]
Accordingly, a first problem to be solved by the present invention is to solve the above-mentioned problems, and when casting an elastic resin into a tire casing, the solid tire can be easily removed, and the product is cracked. It is an object of the present invention to provide a method for manufacturing a solid tire that does not cause damage such as.
[0008]
In addition, the second problem to be solved by the present invention is to solve the above-mentioned problems, and to easily remove a completed solid tire by using it for casting into a tire casing, and to crack the product. It is to provide a casting mold that does not cause damage.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention relating to the method for manufacturing a solid tire according to the first invention of the present application, in the first pattern, a columnar or cylindrical casting mold is provided so as to be split in the axial direction. The tire is provided with a pair of collars spaced apart in the axial direction so that they can move away from the casting mold body, and the other is relatively movable in the axial direction of the casting mold body. After fitting the casting mold into the inner diameter hole of the casing so that the pair of bead portions fits between the pair of flange portions, the annular space formed in the tire casing is filled with an elastic resin material and cured, A part of the casting mold including the collar part is moved in a direction away from the tire casing, and then the collar part that is relatively movable in the axial direction of the remaining casting mold body is a bead part and an elastic resin material. Axle of casting mold body with cured product This is a method for manufacturing a solid tire, in which the bead portion and the cured elastic resin material cured product are moved relative to each other in the pushing direction and demolded.
[0010]
In the first pattern of the method for manufacturing a solid tire according to the first invention described above, a columnar or cylindrical casting mold is provided so as to be split in the axial direction. By separating a part of the mold from the tire casing, it is possible to first easily remove only a part of the casting mold that has no contact area with the elastic resin or has a relatively small area. The internal pressure generated by the resin filling pressure and foaming pressure can be released to some extent.
[0011]
Next, as a method for removing the remaining portion of the casting mold in the next step, the bead portion of the tire casing is moved by a flange portion that can move the bead portion of the tire casing relatively in the axial direction of the casting mold body. The method of moving the part relatively in the direction of pushing is adopted.
[0012]
Although the frictional resistance between the elastic resin material and the casting mold is not reduced sufficiently even after a part of the casting mold including the flange portion is removed, the tire casing extends along the axial direction of the casting mold. By relatively pressing the bead portion with the flange portion, it is possible to reduce the force that causes cracking or the like in the elastic resin material applied to the contact surface of the elastic resin material that is in direct contact with the casting mold. This makes it possible to remove the mold relatively easily without damaging the molded elastic resin material.
[0013]
In the first pattern, the parts to be removed after casting are limited to the collar portion in the first pattern. Therefore, the casting mold need not be provided so as to be separable in the axial direction, and may be provided with a structure capable of moving the collar portion in a direction away from the tire casing. Also in this case, the internal pressure of the tire casing can be released to some extent by removing the collar. In the next step, the casting mold can be removed without damaging the elastic resin material by the same method as in the first pattern.
[0014]
Next, according to a second invention of the present application, in the first pattern, a pair of eaves is provided with an interval in the axial direction of a columnar or cylindrical casting mold, and the eaves are formed of the casting mold main body. It is provided so as to be relatively movable in the axial direction, and the casting mold is fitted into the inner diameter hole of the tire casing so that the pair of bead portions fit between the pair of flange portions, and is formed in the tire casing. After the annular space is filled with an elastic resin material and cured, a pair of flanges and beads that are movable relative to the casting mold body in the axial direction and a cured elastic resin material are poured. This is a solid tire manufacturing method in which the mold body is moved relative to the axial direction of the mold body and removed, and then at least one flange portion is moved away from the tire casing and removed.
[0015]
In the second pattern, in the first pattern, the casting mold is provided so as to be split in the axial direction. When the casting mold is removed, the casting pattern is first separated from the casting mold body. The collar portion is integrated with a part of the divided casting mold.
[0016]
Accordingly, the casting mold body is moved relative to the casting mold main body in the axial direction with respect to the collar portion, the bead portion, and the cured elastic resin material, and then removed, and then the casting mold body having the collar portion is removed. Some may be in contact with the elastic resin, but there is no contact area or is relatively small and can be easily removed.
[0017]
Further, as a means for solving the same problem as described above, in the third invention of the present application, a columnar or cylindrical casting mold of a size that fits into the inner diameter hole of the tire casing is provided, and the shaft of this casting mold is provided. A pair of eaves that can be supported from the outside of the bead portion of the tire casing with a gap in the direction is provided, and one part of the casting mold including one eaves or one eaves is the rest of the casting mold The other flange is provided for casting a solid tire that is movable relative to the casting mold body in the axial direction of the casting mold body. It was a type.
[0018]
The casting mold of the third invention configured as described above is provided with a pair of flanges capable of supporting the bead portion of the tire casing from both outer sides, and further includes a flange portion or a flange portion. Part of the casting mold including the collar part or the part of the casting mold including the collar part first, the part of the casting mold is moved away from the rest of the casting mold. From the tire casing filled with the elastic resin material, the other flange is integrated with the tire casing and moved relative to the axial direction of the casting mold body. According to the first aspect of the present invention, the remaining portion is separated or the remaining portion is separated from the tire casing filled with the elastic resin after removing the flange portion or a part of the casting mold including the flange portion. The method can be adopted.
[0019]
By adopting these methods, the elastic resin in the tire casing can reduce the force that causes cracks or the like in the elastic resin material applied to the contact surface of the elastic resin material that is in direct contact with the casting mold as described above. Demolding can be performed relatively easily without damaging the elastic resin material.
[0020]
Further, as a means for solving the same problem as described above, in the fourth invention of the present application, a columnar or cylindrical casting mold having a size that fits into the inner diameter hole of the tire casing is provided. A pair of eaves that can be supported from the outside of the bead portion of the tire casing with an interval in the axial direction is provided, and a part of the casting mold including the pair of eaves or one eaves and the other eaves The casting mold is provided so as to be relatively movable in the axial direction of the casting mold main body with respect to the remaining portion of the casting mold, and at least one of the pair of flanges can be moved away from the other. It was a casting mold for a solid tire.
[0021]
The casting mold of the fourth invention configured as described above is provided with a pair of flange portions that can be supported from both outer sides on the bead portion of the tire casing. Since it is provided so as to be movable in the axial direction, and at least one of them is movable in a direction away from the other, first, the casting mold or its body is removed from the tire casing filled with the elastic resin, and then The method of the above-described second invention in which one of the collars is moved to remove the mold can be employed. By adopting this method, it is possible to remove the mold relatively easily without damaging the elastic resin material in the tire casing as in the third invention.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a method for manufacturing a solid tire according to the present invention and a casting mold used therefor will be described below with reference to the accompanying drawings.
[0023]
As shown in FIGS. 1 and 2, the solid tire casting mold 1 according to the first embodiment includes a columnar (solid) mold having a size that fits into the inner diameter hole of the tire casing 2. A part 5 of a casting mold having a flange 4 sandwiched in the bead portion 3 from above, a support 34 having a flange 6 sandwiched in the bead portion 3 from below, and a casting mold body 7 are columnar shafts. It is divided into three in the direction. Then, holes 8 and 8 that penetrate the entire casting mold 1 in the axial direction are formed and bolts 9 are inserted. First, one or more springs 35 are inserted between the casting mold body 7 and the support 34. The casting mold body 7 and the support 34 are held in an appropriate positional relationship from both sides by the nuts 11 and 33, and a part 5 of the casting mold is tightened by the nut 10 and then poured. A pair of bead portions 3 are sandwiched from the outside in the vertical direction in the figure between the flange portions 4 and 6 facing each other so as to prevent the collapse of the mold during casting.
[0024]
The casting mold part 5 has an injection hole 13 for injecting an elastic resin material in at least one place, and this is connected to an injection groove 14 formed on the upper surface of the casting mold body 7. It is possible. The injection hole 13 functions satisfactorily if it is provided in one place, but it can also be provided in two or more places if necessary. Alternatively, the injection path may be branched from one injection hole 13 and injected into the cavity formed in the tire casing from two or more locations.
[0025]
In addition to the form shown in FIG. 1, for example, as shown in FIG. 2 (a), the flanges 4 and 6 are made of a disk-like flange 15 of a part 16 of the casting mold by a screw or a well-known fitting structure. You may employ | adopt what attaches to upper part so that attachment or detachment is possible.
[0026]
Further, a part 18 of the casting mold shown in FIG. 2B is obtained by attaching a ring-shaped flange portion 17 to the upper portion by a screw or a well-known fitting structure.
[0027]
Moreover, as shown in FIG.2 (c), the part 20 of a casting type | mold can also attach the cap type collar part 19 so that attachment or detachment is possible with a screw or a well-known fitting structure.
[0028]
As described above, when the casting mold parts 16, 18, 20 having the flange parts 15, 17, 19 are configured, the bead parts of various tire casings are tightened in an optimum state according to their sizes and shapes. it can. Preferably, sealing parts such as O-rings and packings are attached at important points to prevent leakage of the injected resin material.
[0029]
The casting mold main body 7 is not limited to a columnar shape as shown in FIG. 1 but may be partially or entirely cylindrical. Further, the casting mold 1 is not limited to one that can be divided into two in the axial direction as shown in FIG. 1, but may be one that can be divided into three or more. In this case, the outer peripheral surface of each of the divided short cylinders or short cylinders is inclined to form a truncated cone or cylindrical trapezoidal part, or the outer diameter of the divided short cylinders or short cylinders is used for casting. It is preferable to use a mold that gradually decreases in size toward the tip of the mold body 7. Thereby, the ease of removal (demolding) is improved.
[0030]
When the respective outer peripheral surfaces of the divided short columnar or short cylinder are inclined, the inclination angle is set to 3 ° or less, more preferably 0.5 to 2 °. This is because when the inclination is more than 3 °, the protrusion formed on the inner diameter surface of the solid tire is formed large, making it difficult to attach the rim of the wheel, and cracks are likely to occur.
[0031]
Further, the casting mold is divided into two or more and removed from the mold, and it is desirable that the dividing surface be disposed within 10 mm from the boundary between the tire casing and the elastic synthetic resin toward the center of the elastic synthetic resin. This is because if this distance is too long, the divided casting molds are difficult to come off, and cracks may occur in the filled resin.
[0032]
As shown in FIG. 1, the solid tire manufacturing method using the casting mold having such a structure has an inner diameter hole 12 of the tire casing 2, and the casting mold 1 has flange portions 4 and 6 at the tire casings. 2, the bead portion 3 is fitted between the bolts 9 and the nuts 10 and 11, and the elastic resin material P is filled into the annular space formed in the tire casing 2 from the injection hole 13. After making a hole or hardening by properly plugging and curing the air in the tire casing by other known methods, the part 5 of the casting mold is removed, and then the collar part 6 is a direction in which a part 5 of the casting mold is removed from the bead portion 3 of the tire casing by tightening the nut 11 along the axial direction (vertical direction in the figure) of the inner diameter hole 12 with the support body 34 having 6. Extrude into the casting mold body 7 (In the figure, the vertical direction) away from the manufactures solid tire filled with an elastic resin material P to the tire casing 2 by demolding is moved.
[0033]
Incidentally, the rubber tire casing 2 has an annular outer shape and a cross-sectional groove shape, and a bead portion 3 in close contact with the rim of the wheel has a bead filler 3a made of a piano wire embedded therein in the circumferential direction.
[0034]
The elastic resin material P is preferably thermoplastic or thermosetting and soft foamable. When polyurethane is used as such an elastic resin material P, dehydrated polyols, isocyanates, chain extenders, crosslinking agents, catalysts, foaming agents, bubble size regulators, curing agents, etc. are mixed. Foam and harden. Examples of the polyol include polyether and polyester. Examples of the isocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate. The chain extender may be glycol, diamine, etc., and the foaming agent may be carbon dioxide by reaction of water and isocyanate, mixed carbon dioxide (liquid carbon dioxide), chlorofluorocarbons, air, etc. Examples of the bubble size regulator include silicone oil and emulsifier, and examples of the catalyst include amines, organic tin compounds, organic lead compounds, and organic potassium compounds.
[0035]
In addition to the above-mentioned polyurethane, EVA synthetic resin (ethylene vinyl acetate copolymer resin), polyethylene, polystyrene, phenol resin, urea resin, etc. can be used as elastic synthetic resins that can be used in the present invention with foaming properties. Can be mentioned. Furthermore, a thermoplastic elastomer can also be used in the present invention by imparting foamability as described above. As such a thermoplastic elastomer, a styrene-butadiene type, a polyester type, a polyethylene type, a polyurethane type, or a vinyl chloride type can be appropriately selected and used.
[0036]
In addition, the favorable result was obtained using the Nisshinbo Co., Ltd. air light foam as a commercially available foaming polyurethane. When this is used, a main agent composed of an isocyanate and a polyol and an auxiliary agent composed of a foaming agent, a catalyst and the like are mixed and filled into a tire. In this way, it is possible to provide cushioning like an air tire.
[0037]
As shown in FIG. 3, the solid tire manufacturing method according to the second embodiment and the casting mold used in the method are divided into two casting molds 25, and the casting mold body 26a on the upper part thereof. The bead portion 3b is formed by forming a bead portion support ring 27 on the outer periphery of the lower casting mold body 26b and slidably in the axial direction (vertical direction in the figure) of the casting mold 25. Further, a ring 28 for supporting the bead portion supporting ring 27 is screwed to the outer periphery of the casting mold body 26b, and an injection hole 13 is formed on the upper surface of the casting mold body 26a. The mold body 25 is integrated by being clamped from above and below by a clamp (not shown).
[0038]
In the method for manufacturing a solid tire according to the second embodiment, the casting mold main body 26a is removed by removing a clamp (not shown), the ring 28 is loosened and removed, and the bead portion supporting ring 27 is removed from the casting mold main body 26b. On the other hand, the bead portion 3b is pushed up by the bead portion support ring 27 by pushing it up from the bottom in the figure with a hydraulic device or the like, and demolded. As the hydraulic equipment, one that operates by a fluid pressure mechanism such as an air cylinder or a hydraulic cylinder can be adopted.
[0039]
The clearance between the bead portion supporting ring 27 and the casting mold 25 is preferably 5 mm or less in order to improve the demoldability and roundness of the solid tire and prevent the occurrence of cracks during demolding. .
[0040]
As shown in FIG. 4, in the third embodiment, a pair of bead portion supporting rings (removable collar portions) 27, 27 are provided at intervals in the axial direction of a columnar or cylindrical casting mold main body 29. This is a method of manufacturing a solid tire using a casting mold provided so as to be slidable in the axial direction of the casting mold body 29 and removed. In this method, a casting mold main body 29 is fitted into the inner diameter hole of the tire casing 2 so that the pair of bead portions 3 are accommodated between the pair of bead portion supporting rings 27, 27, and The bead support rings 27 and 27 are supported from the outside by a pair of rings 28 and 28. The pair of rings 28 and 28 are fixed to the casting mold main body 29 by a pressing device or the like not shown in the figure, and the annular space of the tire casing 2 is filled with the elastic resin material P, along with a reaction such as foaming. After curing, the casting mold main body with a press device or the like (not shown) with the pair of rings 28, 28 and the bead portion supporting rings 27, 27 along the tire casing 2 29 is a method for manufacturing a solid tire in which 29 is removed from the bead portion supporting ring (rib portion) 27 and the tire casing 2, and then the pair of rings 28, 28 are removed and removed.
[0041]
In this way, the casting mold body 29 can be removed without applying a force that generates cracks in the elastic resin material P.
[0042]
【The invention's effect】
In the solid tire manufacturing method of the present application, as described above, the tire casing is formed by relatively moving the collar portion which is a part of the casting mold and the main body portion of the casting mold in the axial direction of the inner diameter hole. By pushing the bead part of the mold, it is possible to easily remove the finished solid tire by casting it into the tire casing without causing cracks in the elastic resin, and the product is damaged such as cracks. There is an advantage not to let it.
[0043]
In addition, the invention relating to the casting mold for solid tires of the present application adopts a structure in which the collar portion moves relative to the casting mold main body in the axial direction, so that the product has cracks and the like. The casting mold does not cause breakage.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a solid tire for explaining a manufacturing process using a casting mold according to a first embodiment. FIG. 2 is a cross-sectional view of a main part of a casting mold showing examples of flanges of the casting mold. FIG. 3 is a cross-sectional view of a solid tire illustrating a manufacturing process using the casting mold of the second embodiment. FIG. 4 is a solid tire illustrating a manufacturing process using the casting mold of the third embodiment. [Fig. 5] Cross-sectional view of a solid tire explaining a conventional manufacturing process [Explanation of symbols]
1,25 Casting mold 2 Tire casing 3, 3b Bead part 3a Bead filler 4, 6, 15, 17, 19 Saddle part 5, 16, 18, 20 Part of casting mold 7, 26a, 26b, 29 Casting Mold body 8 Hole 9 Bolt 10, 11, 33 Nut 12 Inner diameter hole 13 Injection hole 14 Injection groove 27 Bead part support ring 28 Ring 30 Tapered surface 31 Step part 32 Body part 34 Bead part support part 35 Spring P Elastic resin material

Claims (4)

A pair of eaves are provided at intervals in the axial direction of the columnar or cylindrical casting mold, and one casting part or a part of the casting mold provided integrally with one erecting part is used as the casting mold. Provided in such a manner that it can be divided from the main body in the axial direction, and provided so that the other flange part and the casting mold main body can move relatively in the axial direction,
Fit the casting mold into the inner diameter hole of the tire casing so that the pair of bead portions fits between the pair of flange portions,
After filling and curing the elastic resin in the annular space formed in the tire casing, the part of the casting mold including the one collar part or the one collar part is moved away from the tire casing,
Next, the remaining collar part is demolded by moving the axial bead part of the casting mold main body and the cured elastic resin material together with the bead part and the cured elastic resin material in the pushing direction. Tire manufacturing method. A casting mold that is provided with a pair of collars spaced apart in the axial direction of a columnar or cylindrical casting mold, and can be divided in the axial direction integrally with the pair of collars or one of the collars. And a part of the other flange are provided to be movable with respect to the axial direction of the casting mold body,
Fit the casting mold into the inner diameter hole of the tire casing and store a pair of bead portions between the pair of flange portions,
After filling and curing the elastic resin in the annular space in the tire casing,
A pair of flanges movable in the axial direction of the casting mold body are moved in the axial direction of the casting mold body together with the tire casing and the elastic resin, and are removed from the casting mold body.
Next, a solid tire manufacturing method comprising removing any mold by moving any part of the casting mold including the collar or the mold part away from the tire casing. A pair of eaves that can support a bead portion of the tire casing from the outside by providing a column-shaped or cylindrical casting mold that fits into the inner diameter hole of the tire casing, with an interval in the axial direction of the casting mold And one part of the casting mold including one collar part is provided so as to be movable away from the rest of the casting mold, and the other collar part is , Solid tire casting mold that can move relative to the casting mold body in the axial direction of the casting mold body. A pair of eaves that can support a bead portion of the tire casing from the outside by providing a column-shaped or cylindrical casting mold that fits into the inner diameter hole of the tire casing, with an interval in the axial direction of the casting mold A part of the casting mold including the pair of collars or one collar part and the other collar part in the axial direction of the casting mold body with respect to the remaining part of the casting mold. A mold for casting a solid tire that is relatively movable and further movable in a direction in which at least one of the pair of flanges is separated from the other.

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