JP2022176614A - Manufacturing method of solid tire and molding jig of the same - Google Patents

Abstract

To obtain a solid tire which enables an elastic foam material to be injected into a tire casing smoothly and has good quality.SOLUTION: A molding jig 10 has: a jig body 11 including a fitting part 13 in which a side surface 15 of an outer periphery is fitted in an inner diameter hole 43 of a tire casing 41 and having an inclined surface 16 which inclines from the fitting part 13 to a center of its diameter; and a jig lid body 31 including a closing part 34 which overlaps on the inclined surface 16. In a manufacturing method of a solid tire, the molding jig 10 is used, the fitting part 13 of the jig body 11 is fitted in the inner diameter hole 43 of the tire casing 41, and an elastic foam material 55 is injected into the tire casing 41 from a gap 51 between the inclined surface 16 and a peripheral edge 44b of the inner diameter hole 43 of the tire casing 41. Then, the jig lid body 31 is overlapped on the jig body 11 to close the gap 51 with the closing part 34 and the elastic foam material 55 is foamed.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for manufacturing a solid tire and a jig for molding the same.

As a puncture-proof tire, there is a solid tire 60 in which an elastic foam 66 is filled in a tire casing 61 shown in FIG. The tire casing 61 is an annular one made of rubber or the like. The elastic foam 66 is made of a foam having appropriate hardness and elasticity, such as rigid urethane foam.

As a conventional method for manufacturing a solid tire 60, there is the following method using a molding jig 70 composed of a lower mold 71 and an upper mold 81 shown in FIG. 8 (Patent Document 1).

The lower mold 71 has a cylindrical portion 73 that fits in the inner diameter hole 63 of the tire casing 61 , and an injection hole 76 is formed in the cylindrical portion 73 . The injection hole 76 consists of a vertical groove-shaped recess formed in the edge of the upper surface 74 of the cylindrical portion 73 .
The upper die 81 is configured to cover the injection hole 76 when placed on the upper surface 74 of the cylindrical portion 73 .
The lower mold 71 and the upper mold 81 are joined together by bolts 91 and nuts 93 in an overlapping state.

In a solid tire manufacturing method using a lower die 71 and an upper die 81, as shown in FIG. The foam raw material 65 is injected into the tire casing 61 , and the upper mold 81 is placed on the lower mold 71 and joined with bolts 91 and nuts 93 . After foaming the elastic foam raw material 65 in the tire casing 61 in this state, the lower mold 71 and the upper mold 81 are removed from the tire casing 61 to obtain a solid tire.

JP 2004-174844 A

However, in the conventional method of manufacturing a solid tire using a molding jig 70 consisting of a lower die 71 and an upper die 81, the injection hole 76 of the lower die 71 is formed vertically at the edge of the upper surface 74 of the columnar portion 73. , the flow of the elastic foam raw material 65 injected from the injection hole 76 is poor, and it is difficult to smoothly inject the elastic foam raw material 65 into the tire casing 61 . As a result, the elastic foam material 65 may overflow outside the tire. Even if the elastic foam raw material 65 does not overflow from the injection hole 76 and enters the tire casing 61, it does not enter smoothly. It becomes a thing with variation in hardness.

The present invention has been devised in view of the above points, and is capable of smoothly injecting elastic foam raw material into a tire casing so that the elastic foam formed in the tire casing can be in a foamed state. To provide a method for manufacturing a solid tire having good quality with less variation and a jig for molding the same.

A first aspect of the present invention provides a method for manufacturing a solid tire in which an elastic foam material is injected into the tire casing and foamed to thereby fill the tire casing with the elastic foam material, wherein a jig main body having a fitting portion in which the side surface of the outer circumference fits into the inner diameter hole, the jig main body having a slope inclined from the fitting portion toward the center of the diameter, and a jig cover provided with a closing portion overlapping the slope; The fitting portion of the jig body is fitted into the inner diameter hole of the tire casing, and the elastic foam raw material is introduced from the gap between the inclined surface and the peripheral edge of the inner diameter hole of the tire casing. is injected into the tire casing, the jig lid is placed on the jig body, the gap is closed with the closing portion, and after the elastic foam raw material is foamed, the jig body and the jig lid is removed from the tire casing.

A second aspect of the present invention is a jig for molding a solid tire, comprising a fitting portion for fitting the side surface of the outer periphery into an inner diameter hole of a tire casing, and tilting from the fitting portion toward the center of the diameter. and a jig lid having a closing portion overlapping the slope, wherein when the fitting portion of the jig body is fitted into the inner diameter hole of the tire casing, the A gap for injecting the elastic foam material is formed between the slope and the periphery of the inner diameter hole of the tire casing.

According to the present invention, the fitting portion of the jig body is fitted into the inner diameter hole of the tire casing, and the clearance between the slope inclined from the fitting portion toward the center of the diameter and the peripheral edge of the inner diameter hole of the tire casing. Therefore, since the elastic foam raw material is injected into the tire casing, the elastic foam raw material can smoothly flow into the tire casing, and the elastic foam formed in the tire casing has little variation in foaming state. and a solid tire of good quality can be obtained.

1 is a perspective view showing an embodiment of a molding jig of the present invention; FIG. 1 is a cross-sectional view of a molding jig and a tire casing used in one embodiment of the manufacturing method of the present invention; FIG. FIG. 4 is a cross-sectional view showing a jig main body setting step and an elastic foam raw material injection step in one embodiment of the manufacturing method of the present invention. It is sectional drawing which shows the foaming process in one Embodiment of the manufacturing method of this invention. FIG. 4 is a cross-sectional view of one embodiment in the case of heating in the manufacturing method of the present invention; FIG. 4 is a perspective view showing another embodiment of the molding jig of the present invention; 1 is a cross-sectional view of a solid tire; FIG. FIG. 11 is a perspective view showing a conventional molding jig; FIG. 10 is a cross-sectional view showing the manufacturing of a conventional solid tire;

An embodiment of a molding jig of the present invention and a solid tire manufacturing method using the molding jig will be described.
A molding jig 10 according to an embodiment of the present invention shown in the perspective view of FIG. 1 and the cross-sectional view of FIG. 2 is used when manufacturing a solid tire having the same configuration as the solid tire 60 shown in FIG. It has a jig main body 11 and a jig lid 31 . The jig body 11 and the jig lid 31 are made of metal or resin.

The jig body 11 has a fitting portion 13 formed on one side of a disc-shaped portion 12 having a diameter larger than the inner diameter hole 43 of the tire casing 41 . The fitting portion 13 has an outer peripheral side surface 15 that fits into the inner diameter hole 43 of the tire casing 41 . On the distal end side of the jig body 11 , a slope 16 inclined from the fitting portion 13 toward the center of the diameter of the fitting portion 13 continues from the side surface 15 of the fitting portion 13 and extends along the entire circumference of the jig body 11 . is formed in

As shown in FIG. 3A, the height of the side surface 15 of the fitting portion 11 is determined when the fitting portion 13 is fitted from one side into the inner diameter hole 43 of the tire casing 41 during manufacturing of the solid tire. , a gap 51 is formed between the peripheral edge 44b on the other side of the inner diameter hole 43 of the tire casing 41 and the slope 16. As shown in FIG.

The outer diameter of the side surface 15 of the fitting portion 11 is equal to or larger than the inner diameter hole 43 of the tire casing 41 by a predetermined amount. It is preferable that the side surface 15 of the fitting portion 11 is in close contact with the peripheral edge 44 a on one side of the inner diameter hole 43 .

In the illustrated embodiment, the fitting portion 13 has tapered corners (inclined surfaces 16) on the tip side of the cylindrical shape, but is not limited to this, and fits into the inner diameter hole 43 of the tire casing 41. What is necessary is just to have the side 15 and the slope 16 of the outer periphery.

The jig lid 31 has a closing portion 34 that overlaps the inclined surface 16 of the jig body 11 when it overlaps the distal end side of the jig body 11 . The jig lid body 31 of the embodiment has a cylindrical portion 33 having an outer diameter substantially equal to the outer peripheral side surface 15 of the fitting portion 13 on one side of a disk-shaped portion 32 having a diameter larger than the inner diameter hole 43 of the tire casing 41 . The center side of the tip of the columnar portion 33 is recessed in a truncated cone shape to form a closed portion 34 whose edge overlaps the slope 16 of the jig body 11 .

At the center of the jig main body 11 and the jig lid 31, bolt insertion holes 17 and 37 are formed to communicate with each other when the jig lid 31 is placed on the jig main body 11, so that a bolt 38 can be inserted. ing. The bolt 38 connects the jig main body 11 and the jig lid 31 when manufacturing a solid tire, which will be described later.

An embodiment of a solid tire manufacturing method using the molding jig 10 will be described.
A solid tire manufacturing method includes a jig body setting step, an elastic foam raw material injection step, a foaming step, and a molding jig removing step.

In the process of setting the jig main body, as shown in FIG. 43 to form a gap 51 between the inclined surface 16 on the tip side of the jig body 11 and the peripheral edge 44 b on the other side of the inner diameter hole 43 of the tire casing 41 .

In the step of injecting the elastic foam raw material, as shown in FIG. A predetermined amount of elastic foam raw material 55 is injected into the tire casing 41 . At this time, the elastic foam raw material 55 is guided into the tire casing 41 along the slope 16 of the jig body 11 , so that it can smoothly flow into the tire casing 41 . The elastic foam raw material 55 is a liquid foam raw material that forms an elastic foam suitable as an elastic foam for a solid tire, and examples thereof include rigid polyurethane foam raw materials. Reference numeral 54 designates the nozzle of the injection device for the elastic foam raw material 55 .

Injection of the elastic foam raw material 55 into the tire casing 41 is preferably performed along the peripheral edge 44b of the inner diameter hole 43 of the tire casing 41 and is preferably performed over the entire circumference of the inner diameter hole 43 . Thereby, unevenness of the elastic foam material 55 injected into the tire casing 41 can be prevented, and uneven foaming of the elastic foam material 55 within the tire casing 41 can be prevented.

As a method of injecting the elastic foam raw material 55 along the peripheral edge 44b of the inner diameter hole 43 of the tire casing 41, the center of the jig body 11 is set as the axis, and the tire casing 41 and the jig body 11 are moved in the circumferential direction. Alternatively, the elastic foam raw material 55 may be injected while moving the nozzle 54 of the injection device along the peripheral edge 44b of the inner diameter hole 43. Either method may be used.

In the foaming step, as shown in FIG. 4, the jig lid 31 is placed on the jig body 11, and the closing portion 34 of the jig lid 31 overlapping the inclined surface 16 of the jig body 11 is used as shown in FIG. closes the gap 51 shown in . In this state, the elastic foam raw material 55 inside the tire casing 41 is foamed. The foaming of the elastic foam raw material 55 forms and fills the elastic foam 56 within the tire casing 14 .

Further, in the foaming process, when the elastic foam raw material 55 expands and fills the tire casing 41, the closing portion 34 of the jig lid 31 overlaps the inclined surface 16 of the jig body 11. The contact area of the boundary surface (overlapping surface) between 11 and jig lid 31 is increased, and the sealing performance of the boundary surface (overlapping surface) between jig main body 11 and jig lid 31 is enhanced. As a result, the elastic foam raw material 55 filling the tire casing 41 is prevented from leaking out from the interface (overlapping surface) between the jig body 11 and the jig lid 31 .

In the foaming step, the tire casing 41 may be heated to accelerate the foaming reaction of the elastic foam raw material 55 inside the tire casing 14 . For example, as shown in FIG. 5, the tire casing 41 may be housed in a heating container 59 fitted with an electric heater, a hot water pipe, etc., and the foaming process (or the injection/foaming process) may be performed. The heating container 59 may be capped after the elastic foam raw material 55 is injected. Alternatively, the injection of the elastic foam raw material 55 and the subsequent foaming may be performed using a mold integrated with a heating container.

In the molding jig removal process, after the elastic foam raw material 55 is foamed (after the elastic foam 56 is formed), the jig main body 11 and the jig lid 31 are separated and removed from the inner diameter hole 43 of the tire casing 41 . to get a solid tire. The manufactured solid tire is mounted on a bicycle, a wheelchair, a golf cart or the like with a wheel attached to the inner diameter hole 43 of the tire casing 41 .

It should be noted that the present invention is not limited to the embodiments, and can be modified along the gist of the invention.
For example, in the molding jig 10 of the above-described embodiment, the inclined surface 16 is formed on the entire periphery of the jig main body 11 on the distal end side. As in the molding jig 10A, a slope 16A may be provided on a portion of the tip side of the jig body 11A. Reference numeral 13A is a fitting portion, 15A is an outer peripheral side surface, 31A is a jig cover, and 34A is a closing portion.
Also, the method of connecting the jig body and the jig lid when foaming the elastic foam is not limited to bolts and nuts. can be a method.

According to the present invention, the elastic foam raw material can be smoothly injected into the tire casing, the elastic foam raw material can be foamed in the tire casing with little variation, and a solid tire having good quality can be obtained. be able to.

REFERENCE SIGNS LIST 10 molding jig 11 jig body 13 fitting portion 15 side surface 16 slope 31 jig lid 34 closing portion 41 tire casing 43 inner diameter hole 44a, 44b inner diameter hole rim 51 gap 55 elastic foam raw material 56 elastic foam

Claims (4)

In a method for manufacturing a solid tire in which an elastic foam material is filled in the tire casing by injecting an elastic foam raw material into the tire casing and foaming the tire casing,
A jig body having a fitting portion in which a side surface of the outer periphery fits into the inner diameter hole of the tire casing, a jig body having a slope inclined from the fitting portion toward the center of the diameter, and a closing portion overlapping the slope. Using a molding jig having a lid,
fitting the fitting portion of the jig body into the inner diameter hole of the tire casing, and injecting the elastic foam raw material into the tire casing from a gap between the inclined surface and the peripheral edge of the inner diameter hole of the tire casing;
The jig cover is placed on the jig main body to close the gap with the closing portion, and after the elastic foam raw material is foamed, the jig main body and the jig cover are removed from the tire casing. A method for manufacturing a solid tire. 2. The method of manufacturing a solid tire according to claim 1, wherein the slope is formed on the entire circumference of the jig body. 3. The method of manufacturing a solid tire according to claim 1, wherein the elastic foam raw material is injected along the periphery of the inner diameter hole of the tire casing. a jig body having a fitting portion in which the side surface of the outer periphery fits into an inner diameter hole of a tire casing, and having a slope inclined from the fitting portion toward the center of the diameter;
a jig lid including a closing portion that overlaps with the slope;
When the fitting portion of the jig body is fitted into the inner diameter hole of the tire casing, a gap for injecting the elastic foam raw material is formed between the inclined surface and the periphery of the inner diameter hole of the tire casing. A jig for molding a solid tire.

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