JPH10258466A - Molding method for solid tire and mold used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding to manufacture a solid tire of high quality by scarcely introducing many air bubbles in synthetic resin stock solution, and a mold therefor. SOLUTION: In the method for molding a solid tire for molding the tire by integrally adhesively molding a synthetic resin molding at outside of a rim fitment 1, the mold 10 used by placing in the method comprises an upper cover 11 covering an upper surface of the mold 10 to inject synthetic resin stock solution in an annular space 5 between the mold 10 and the fitment 1 placed in the mold 10, an air bleeding cylinder provided at a position different from a resin injection port 12a to have the space 5 at its bottom. In the case of injecting the solution, a structure that the solution can be injected while bleeding the air in the space 5 from an air bleeding hole 13a is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a solid tire, in which a molded article made of a synthetic resin such as polyurethane, which is thermoset on the outside of a rim fitting, is integrally molded, and used in carrying out the molding method. Particularly, an upper cover for covering an upper surface of the mold in an annular space between a bottomed cylindrical solid tire molding mold and a rim fitting placed on the mold. A synthetic resin stock solution is injected from a resin injection cylinder having a resin injection port provided therein at a position different from the resin injection port and air is removed from an air extraction cylinder having an air vent hole provided therein, and then cured and removed. The present invention relates to a method for molding a solid tire having a feature including a molding step, and to providing a molding die to be used when the molding method is performed.

[0002]

2. Description of the Related Art As a conventional method of manufacturing a solid tire, a cylindrical mold 3 having an open top as shown in FIG.
1 and the rim fitting 32 is placed in the rim fitting 32 and the mold 31.
A method is known in which a synthetic resin stock solution is injected into an annular space 33 between the two, and the mixture is heated and hardened. After demolding, a predetermined shape is formed by mechanical cutting such as lathing.

On the other hand, in Japanese Patent Publication No. 6-49301, as shown in FIG. 6, a narrow annular resin injection opening 42 is formed on the upper surface of a molding die 41 composed of an upper die 41a and a lower die 41b. A burr formed by injecting a synthetic resin stock solution along the wall surface of the mold 41 or the rim fitting 43 from the opening portion 42, curing by heating, demolding, and curing while protruding from the annular opening portion 42. A manufacturing method is disclosed in which a part is cut to obtain a predetermined final shape.

[0004]

However, in the above method, since the upper part of the mold 31 is open, the lower half of the annular synthetic resin molded part formed integrally with the rim fitting 32 is the final part. Although it can be formed into a shape, the upper half cannot be formed into the final shape. Therefore, it is necessary to apply a mechanical cutting process such as lathing to the molded product formed by the mold 31, and the amount of resin to be cut is large. The waste of raw materials is large, and the cost of machining is also high.

In addition, since the operation of injecting the synthetic resin material into the mold 31 is performed manually, there is a problem that the working efficiency is poor.

On the other hand, as described above, the above method uses a narrow annular resin injection opening 42 provided on the upper surface of a molding die 41.
Injection of a synthetic resin stock solution, curing by heating, and removal from the mold. A predetermined final shape can be relatively easily formed by cutting off a burr portion that is cured while protruding from the annular opening 42. Although it is possible to mold a solid tire having the same, it is extremely difficult to adjust the injection speed of the synthetic resin stock solution, and when the resin stock solution is injected, many small air bubbles easily enter the synthetic resin stock solution. Since the curing is performed while the bubbles are still contained, there is a problem that if a molded body in which the bubbles remain is formed, the quality is deteriorated.

The present invention has been intensively developed in view of such circumstances, and a problem to be solved is to solve the above-mentioned problems of the conventional solid tire molding method.

[0008] The purpose is to prevent a large number of small air bubbles from entering the synthetic resin stock solution at the time of injection of the resin stock solution, and therefore, no air bubbles remain in the cured synthetic resin molded body. It is an object of the present invention to provide a molding method capable of producing a high-quality solid tire and a molding die used when performing the molding method.

[0009]

The gist of the means adopted by the present invention to solve the above-mentioned problems is as described in the above-mentioned claims.

[0010] Claims 1 and 2 adopting such a configuration.
According to the solid tire molding method described above, in the annular space between the bottomed cylindrical solid tire molding die and the rim fitting placed on the die, the upper lid covering the upper surface of the die is provided. From the resin injection cylinder that is provided and has a resin injection port on the bottom surface,
Injecting a synthetic resin stock solution while bleeding air from an air vent having an air vent hole on the bottom surface provided at a position different from the resin injection port, injecting, curing and removing the mold, the annular space is configured. When injecting the synthetic resin stock solution into the synthetic resin stock solution, it is difficult for air bubbles to enter into the synthetic resin stock solution, and the synthetic resin molded body can be cured in a state where no air bubbles remain, and the synthetic resin is hardened outside the rim fitting. The molded article can be integrally bonded and molded, and a high-quality solid tire can be manufactured reliably and inexpensively.

[0011] Claims 3 and 4 adopting such a configuration.
According to the molding die described above, a mold for molding a solid tire, and an upper surface of the mold to inject a synthetic resin stock solution into an annular space between a rim fitting placed on the mold. A resin injection cylinder having a resin injection port is provided on the bottom surface of the upper lid to be covered, and an air release cylinder having an air release hole is provided at a position different from the resin injection port on the bottom surface to discharge air in the annular space. Therefore, when injecting the synthetic resin stock solution, the synthetic resin stock solution can be injected while removing the air in the annular space from the air vent hole, and the synthetic resin molded body is cured in a state where no air bubbles remain. A synthetic resin molded body can be integrally formed on the outside of the rim fitting by adhesive bonding. That is, a high-quality solid tire can be formed reliably at low cost.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a solid tire molding method according to the present invention, in which a synthetic resin molded body is integrally bonded to the outside of a rim, and a solid tire molding die used in this method. A detailed description will be given based on this.

In carrying out the method according to the present invention, as a synthetic resin raw material to be used, polyurethane resin is preferable because it is excellent in terms of handleability, friction resistance, weather resistance, etc., but gold is used as a liquid. There is no particular limitation as long as it can be filled into the mold and can be cured as it is. Instead of the polyurethane resin, a thermosetting resin represented by a urea resin, an epoxy resin, an unsaturated polyester resin, or the like is used. It may be a known room-temperature-curable resin instead of a thermosetting resin.

Further, reinforcing fibers typified by glass fiber, aramid fiber, carbon fiber, ceramic fiber and the like can be added to the synthetic resin raw material as a filler, and further, a lubricant or plasticizer, carbon, ceramic, Powders or chips of talc, fluorinated resin, polyethylene, natural or synthetic rubber, etc. may be added.

[0015] In addition to the above-mentioned synthetic resin raw material, a material obtained by appropriately blending pigments such as carbon black and titanium white, and additives such as a foaming agent and a flame retardant, in addition to the reinforcing fibers and the lubricant, is used as a starting material. You can also.

FIG. 1 is a schematic perspective view of a solid tire molding die 10 used in carrying out the solid tire molding method of the present invention, and FIG. 2 is a perspective view of the solid tire molding die 10 shown in FIG. FIG. 3 is a sectional view, and FIG. 3 is a molding die 10 shown in FIG.
It is a schematic plan view of. 2 and 3, both the resin injection cylinder 12 and the air extraction cylinder 13 that are detachably fitted to the upper lid 11 that covers the upper surface of the mold 10 are omitted.

In the figure, a molding die 1 for a solid tire is shown.
Reference numeral 0 denotes a lower mold 2 having a circular concave portion on the upper surface and having a cylindrical rim fitting 1 placed in the center of the concave portion, fitted under the upper mold 3 and attached and detached on the upper mold 3. A disc-shaped upper lid 11 having a resin injection cylinder 12 and an air vent cylinder 13 which are freely fitted and locked is fitted. An annular step is provided on the outer periphery of the lower surface of the upper lid 11, and the step is provided. The part is fitted into the cylinder of the rim fitting 1, and the synthetic resin stock solution is placed in an annular space 5 surrounded by the outside of the rim fitting 1 and the inner surfaces of the lower mold 2 and the upper mold 3. The resin is injected from the resin injection port 12a along the outer surface of the rim fitting 1 and then cured.

The resin injection port 12a is connected to the resin injection tube 12
And a substantially arc-shaped gap provided between the outside of the rim fitting 1 and the upper inner diameter of the upper mold 3. That is, the resin injection cylinder 12 is a pseudo-bottomed cylinder that stores the synthetic resin stock solution so as to supply the synthetic resin stock solution through a substantially arc-shaped gap communicating with the annular space 5.

The air vent 13 is provided with the resin injection port 1.
It is arranged at the edge of the upper lid 11 on the side opposite to 2a, and includes a substantially arc-shaped gap provided between the outside of the rim fitting 1 and the upper inner diameter of the upper mold 3. That is, this air extraction cylinder 13
Is a pseudo-bottomed cylinder provided for adjusting the air discharge speed in the annular space 5 so as to adjust the injection speed of the synthetic resin stock solution when the synthetic resin stock solution is injected into the annular space 5. .

Therefore, when the synthetic resin stock solution is filled into the resin injection cylinder 12, the synthetic resin stock solution is discharged through the resin injection port 12a and the air in the annular space 5 is discharged through the air vent hole 13a. The injection can be performed into the annular space 5 at the injection speed. That is, at the time of injecting the resin stock solution, the synthetic resin stock solution does not become air bubbles by being entrained in air and mixed.

Next, the manufacturing method of the present invention carried out by using the mold 10 is as follows.

As shown in FIG. 4, the mold 10 filled with the rim fitting 1 is heated to about 100 ° C. in a preheating furnace while being moved by a conveyor system, and is moved to a predetermined position below the casting apparatus 20. When stopped, the synthetic resin stock solution discharged from the discharge port of the casting head 21 of the casting device 20 falls into the resin injection cylinder 12 and starts to flow into the annular space 5.

As described above, a resin injection port 12 a communicating with the annular space 5 is provided on the substantially bottom surface (upper lid 11) of the resin injection tube 12 so that the resin injection tube 12 can flow along the outer surface of the rim fitting 1. In the position on the opposite side, an air vent hole 1 is formed in the substantially bottom surface (top lid 11).
An air vent cylinder 13 having an air vent 3a is provided, and the air equivalent to the volume of the synthetic resin stock solution filled in the annular space 5 through the air vent 13a can be discharged at a constant discharge speed. Therefore, the synthetic resin stock solution can be injected into the annular space 5 at a constant injection speed, and the synthetic resin stock solution does not become air bubbles due to entrainment of air during the injection. The amount of the synthetic resin stock solution to be injected substantially corresponds to the amount that the annular space 5 is completely filled and slightly overflows from the air vent hole 13a.

Then, the synthetic resin stock solution is heat-cured as it is by heat treatment, demolded, and then cured at the position of the resin inlet 12a and the position of the air vent 13a, respectively, to cure the shapes of the resin inlet 12a and the air vent 13a. When all of the parts are cut and formed, a solid tire as a final product can be formed.

The position of the resin inlet 12a and the air vent 13a and the size and shape of the gap communicating with the annular space 5 are not limited, and the design may be changed as appropriate without departing from the gist of the present invention. Although possible, in the present invention, the dimensions of each part of the upper lid 11 of the mold 10 and the positional relationship between the upper lid 11 and the air vent 13a are extremely important.

At the same time as the synthetic resin stock solution is filled into the resin injection cylinder 12, it flows into the annular space 5 from the resin injection port 12a, but at this time, the dimensions, shape, arrangement position, etc. of the resin injection port 12a and the air vent hole 13a are not appropriate. In this case, the synthetic resin stock solution cannot be smoothly injected. In order for the synthetic resin stock solution to be smoothly supplied from the resin injection port 12a without entraining bubbles, the relationship between the viscosity of the resin stock solution, the injection speed, the width and length of the resin injection port 12a, and the width and length of the air vent hole 13a is required. Because they are intricately entangled, they cannot be determined in a straightforward manner.

In short, in order for the synthetic resin stock solution to be smoothly supplied from the resin injection port 12a without entrapping air bubbles, the viscosity of the resin stock solution, the injection speed, the width and length of the resin injection port 12a, and the width and width of the air vent hole 13a. Since the relationship with the length is complicatedly intertwined, it is necessary to appropriately determine the final condition.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The solid tire molding method of the present invention will be described below in more detail with reference to embodiments. The solid tire of the present embodiment is obtained by integrally forming a synthetic resin molded body having a thickness of 26 mm outside the rim fitting 1 having an outer diameter of 126 mm. It is a thermosetting polyurethane molding composition that is thermoset in a so-called mold frame.

Mold 10 for solid tire of the embodiment
Has a circular recess with an inner diameter of 178.5 mm on the upper surface and a lower mold 2 on which a cylindrical rim fitting 1 with an outer diameter of 126 mm can be placed at the center of the recess. An upper mold 3 having a circular concave portion on the lower surface and an opening having an inner diameter of 131 mm is detachably fitted, and
An annular step is provided on the lower surface, and the step is fitted into the cylindrical shape of the rim fitting 1 so that a disc-shaped upper lid 11 is detachably provided in the opening of the upper mold 3.

A notch having a width of 3 mm in an arc shape corresponding to 60 degrees (radian) from the center portion is formed in the peripheral portion of the disk-shaped upper cover 11, and the center portion is formed in the opposite peripheral portion. 30 degree (radian) equivalent arc from the part, width 3mm
Is formed.

Therefore, when the upper mold 3 is fitted on the lower mold 2 on which the cylindrical rim 1 is placed, and the upper lid 11 is provided in the cylinder of the rim 1, the upper mold 3 Between the upper inner diameter and the outside of the rim fitting 1, an arc-shaped gap having a width of 3 mm and equivalent to 60 degrees (radian) is formed, thereby forming the resin injection port 12a and a width of 3 mm and 60 degrees ( An arc-shaped gap corresponding to (radian) is formed, and the air vent hole 13a is constructed. Furthermore, an annular space 5 surrounded by the outside of the rim fitting 1 and the inner surfaces of the lower mold 2 and the upper mold 3 is formed, and a place for thermally curing the synthetic resin stock solution is constructed.

At the position where each of the cuts is arranged, there is provided a pseudo bottom surface in which a region extending between the upper surface of the upper lid 11 and the upper surface of the upper mold 3 is substantially a bottom surface by detachably fitting a cylindrical body. A bottom resin injection cylinder 12 and an air vent cylinder 13 are formed, and all of the cuts are provided on this pseudo bottom surface.

That is, as described above, the resin injection cylinder 12
Is a pseudo-bottomed cylinder body including substantially all of the gap communicating with the annular space 5 on its substantially bottom surface (upper lid 11), and the air bleeding cylinder 13 is formed in the annular space through the gap communicating with the annular space 5. 5 is a pseudo-bottomed cylindrical body which is arranged on the side opposite to the position where the resin injection cylinder 12 is arranged so as to release the air, and includes all the gaps. Therefore, when the synthetic resin stock solution is filled into the resin injection cylinder 12, the synthetic resin stock solution is filled with the resin injection port 1.
The air in the annular space 5 can be injected into the annular space 5 at a constant injection speed while discharging the air in the annular space 5 through the air vent hole 13a through 2a. In other words, when injecting the resin stock solution,
The synthetic resin stock solution does not become air bubbles due to entrained air and mixed.

Next, the method for molding a solid tire, which is carried out using the present mold 10, will be described in more detail as follows.

The casting apparatus 20 has a storage / deaeration tank 22 for storing the liquid A, a storage tank 23 for storing the liquid B, and a casting head 21.
It is connected to a vacuum device 24 and degassed under reduced pressure. The solution A and the solution B are supplied to the respective storage tanks 22 and 23 via a supply line (not shown) having a check valve at an intermediate portion. In addition,
In order to improve the degassing efficiency of the liquid A, the liquid is constantly stirred gently.

The degassed liquids A and B are supplied to pipes 22a, 23 connected to the respective storage tanks 22, 23.
a to the casting head 21 and the casting head 2
1 is uniformly mixed.

Below the casting head 21, there is provided a conveyor system which is held horizontally, and the mold 10 filled with the rim fitting 1 is moved by the conveyor system to 100 ° C. in the preheating furnace. When the mixture is heated back and forth and stopped at a predetermined position below the casting apparatus 20, a predetermined amount of the mixed liquid (synthetic resin stock solution) discharged from the discharge port of the casting head 21 of the casting apparatus 20 is injected into the resin. It falls into the cylinder 12.
At the same time, the synthetic resin stock solution starts to flow into the annular space 5 via the resin injection port 12a. The mold 10 filled with the rim fitting 1 and assembled may be manually conveyed on a support table horizontally held below the casting head 20.

Then, 1 is maintained while being held in parallel.
The synthetic resin stock solution was thermally cured as it was by a heat treatment at 10 ° C., and after demolding, it was cured at the position of the resin injection port 12a and the position of the air vent hole 13a, respectively.
When all the hardened portions having the shape a and the air vent holes 13a are cut and formed, a solid tire as a final product can be formed.

In the practice of the method according to the present invention, as a synthetic resin raw material to be used, polyurethane resin is preferable because it is excellent in handling properties, friction resistance, weather resistance, etc. There is no particular limitation as long as it can be filled in the mold 10 and can be cured as it is. Instead of the polyurethane resin, thermosetting represented by urea resin, epoxy resin, unsaturated polyester resin, etc. It may be a resin, or may be a known room temperature-curable resin instead of a thermosetting resin.

Further, reinforcing fibers typified by glass fiber, aramid fiber, carbon fiber, ceramic fiber and the like can be added to the synthetic resin raw material as a filler, and further, a lubricant or plasticizer, carbon, ceramic, Powders or chips of talc, fluorinated resin, polyethylene, natural or synthetic rubber, etc. may be added.

As a starting material, a material obtained by appropriately blending the synthetic resin material with pigments such as carbon black and titanium white, and additives such as a foaming agent and a flame retardant, in addition to the reinforcing fibers and the lubricant, is used. You can also.

[0042]

As described above, the method for molding a solid tire according to claims 1 and 2 provides a method for forming a solid tire in an annular space between a molding die for a solid tire and a rim fitting placed on the molding die. Since the synthetic resin stock solution is injected at a predetermined constant speed while bleeding the air in the annular space, when the synthetic resin stock solution is injected into the annular space, it is difficult for air bubbles to enter the synthetic resin stock solution and bubbles remain. It is possible to cure the synthetic resin molded body in a state where it is not performed, it is possible to integrally bond the synthetic resin molded body to the outside of the rim fitting, and it is possible to reliably manufacture a high quality solid tire at low cost. An exceptionally remarkable effect can be obtained.

In the molding die for a solid tire according to the third and fourth aspects, no air bubbles remain in the annular space between the molding die for the solid tire and the rim fitting placed on the molding die. Since the synthetic resin stock solution can be injected in the state, a particularly remarkable effect can be obtained that a high-quality solid tire can be molded at low cost and reliably.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a molding die used when performing a method for molding a solid tire of the present invention.

FIG. 2 is a schematic vertical sectional view of a molding die shown in FIG. 1, in which both a resin injection cylinder and an air vent cylinder are omitted.

3 is a schematic plan view of the molding die shown in FIG. 1,
Both the resin injection cylinder and the air extraction cylinder are omitted.

FIG. 4 is a schematic view of a main part of a solid tire casting apparatus.

FIG. 5 is a schematic longitudinal sectional view of a bottomed cylindrical mold used in a conventional method of manufacturing a solid tire.

FIG. 6 is a schematic longitudinal sectional view of a bottomed cylindrical mold used in the manufacturing method disclosed in Japanese Patent Publication No. 6-49301.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rim metal fitting 2 ... Lower mold 3 ... Upper mold 5 ... Annular space 10 ... Molding die 11 ... Upper lid 12 ... Resin injection cylinder 12a ... Resin injection port 13 ... Air extraction cylinder 13a Air extraction hole 20 ... Casting device 21 ... Casting head 22 ... Storage / deaeration tank 22a ... Pipe 23 ... Storage tank 23a ... Pipe 24 ... Vacuum device 30 ... Conventional molding die 31 ... Bottomed cylindrical die 32 ... Rim fitting 33 ... Annular space 40 ... Molding mold 41 described in Japanese Patent Publication No. 6-49301 41 Molding mold 41a Upper mold 41b Lower mold 42 Resin injection opening 43 ... Rim fitting

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 22 B29L 30:00

Claims (4)

[Claims] 1. A solid tire molding method for molding a solid tire by integrally bonding a synthetic resin molded body to the outside of a rim fitting, wherein the rim fitting is mounted on a bottomed cylindrical solid tire molding die. In the annular space between the rim fitting and the mold, a different position from the resin injection port is provided from a resin injection cylinder provided on an upper lid for covering the upper surface of the mold and having a resin injection port on its bottom surface. It is characterized in that it comprises a step of injecting, curing, and demolding a synthetic resin stock solution while bleeding air in the annular space through an air bleeding cylinder having an air bleed hole on the bottom surface thereof. Solid tire molding method. 2. The method for molding a solid tire according to claim 1, wherein both the resin injection port and the air vent hole are arc-shaped slit holes. 3. A mold for forming a solid tire having a bottomed cylindrical shape, which is used for integrally molding a synthetic resin molded body outside a rim fitting to form a solid tire. In order to inject the synthetic resin stock solution into the annular space between the mold and the rim fitting mounted on the mold, a resin injection cylinder having a resin injection port on the bottom surface of an upper lid covering the upper surface of the mold is provided. An air vent cylinder having an air vent hole is provided at a position different from the resin injection port on the bottom surface to discharge air in the annular space, and when injecting the synthetic resin stock solution, the air vent hole is used. A molding die capable of injecting the synthetic resin stock solution while bleeding air from the annular space. 4. The molding die according to claim 3, wherein both the resin injection port and the air vent hole are arc-shaped slit holes.