JP2008213407A - Manufacturing method of solid tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a solid tire capable of easily enhancing a productive efficiency of a solid tire having a plurality of elastic parts. <P>SOLUTION: The solid tire has a second elastic part between a wheel and a first elastic part having a running surface. The manufacturing method of the solid tire includes a first forming process of forming the first elastic part, and a second forming process of forming the second elastic part. In the first forming process a cylindrical mold 31 in which a raw material 21 of the first elastic part is cast is rotated in the circumferential direction. The mold is rotated in the first forming process so that the axis C of revolution is directed to the horizontal direction. In the second forming process the wheel is placed in the mold in which the first elastic part was formed, and the second elastic part is formed by casting a raw material of the second elastic part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a solid tire such as a transport wheel.

Solid tires are wheels for industrial vehicles such as automated guided vehicles and forklifts, wheels for transportation in automatic warehouses, multilevel parking lots, various manufacturing facilities, wheels for play equipment such as roller coasters and ferris wheels, etc. (See Patent Document 1). Such a solid tire includes a wheel and an elastic portion that covers the outer peripheral surface of the wheel, and the elastic portion is an important part that greatly contributes to performances such as durability and impact resistance of the solid tire. In order to improve the performance of such an elastic portion, a solid tire is proposed in which the elastic portion is composed of two layers of a high-hardness elastic layer and a low-hardness elastic layer (see Patent Document 2). In the solid tire of Patent Document 2, a mold in which a raw material for an elastic part is injected is fixed to a vertical centrifugal molding machine, and the elastic part is formed by a centrifugal force accompanying the rotation of the mold.
JP 2004-161042 A Japanese Unexamined Patent Publication No. 08-40008

  By the way, in patent document 2, when shape | molding the elastic part of a solid tire, the metal mold | die is rotated so that the direction of the rotating shaft line may follow a perpendicular direction. At this time, the raw material of the elastic portion flows along the inner peripheral wall of the mold after flowing along the bottom surface of the mold due to the centrifugal force accompanying the rotation of the mold. Such a flow of the raw material tends to remain on the bottom surface in the mold. And the raw material which remained on the bottom wall of a metal mold | die will produce | generate an unnecessary substance in a metal mold | die. As described above, the solid tire having a plurality of elastic portions can improve performance, but it is easy to generate unnecessary materials from the raw material. For this reason, as a result of requiring time and labor for removing unnecessary items from the mold or the like, the production efficiency of the solid tire is lowered.

  The present invention has been made in view of such conventional circumstances, and an object of the present invention is to provide a method for manufacturing a solid tire that can easily increase the production efficiency of a solid tire having a plurality of elastic portions.

  In order to achieve the above object, a method for manufacturing a solid tire according to claim 1 is a method for manufacturing a solid tire in which a second elastic portion is provided between a wheel and a first elastic portion having a running surface. In the method, a first molding step of molding the first elastic portion by rotating a cylindrical mold into which the raw material of the first elastic portion is injected in its circumferential direction, and molding the first elastic portion A second molding step in which the wheel is disposed in the mold and the second elastic portion is molded by injecting the raw material of the second elastic portion, and the mold in the first molding step includes: The gist is that the rotation axis is rotated along the horizontal direction.

  According to this method, since the mold in the first molding step is rotated so that the direction of the rotation axis is along the horizontal direction, the raw material of the first elastic portion is the inner peripheral wall of the mold having a cylindrical shape. To flow along. For this reason, it is hard for the raw material of a 1st elastic part to adhere to parts other than the inner peripheral wall in a metal mold | die. Therefore, as a result of suppressing the generation of unnecessary materials from the raw material of the first elastic portion in the mold, it is possible to reduce the labor of removing such unnecessary materials.

  According to a second aspect of the present invention, in the solid tire manufacturing method according to the first aspect, in the first molding step, the mold is brought into contact with a driving roller, and the driving roller is rotationally driven to rotate the die. The gist is that it is a step of rotating the mold.

  According to this method, since the mold is rotated by the drive roller in contact with the mold, it is possible to omit the trouble of connecting the drive shaft to the mold when the mold is driven to rotate. For this reason, a 1st shaping | molding process can be simplified.

  According to a third aspect of the present invention, in the solid tire manufacturing method according to the second aspect, in the first molding step, the mold is placed on the driving roller and a roller provided in parallel with the driving roller. Then, the gist is that it is a step of rotating the mold.

  According to this method, the mold rotated by the rotational drive of the drive roller is also supported by the rotating roller. For this reason, it becomes possible to rotate the mold in a more stable state.

  According to the present invention, it is easy to increase the production efficiency of a solid tire having a plurality of elastic portions.

Hereinafter, an embodiment embodying a method for producing a solid tire of the present invention will be described with reference to the drawings.
As shown in FIGS. 1A and 1B, the solid tire includes a cylindrical wheel 11 and a tread portion 12 provided on the outer periphery of the wheel 11. The tread portion 12 is formed between the wheel 11 and the first elastic portion 13 while forming an annular shape and having a traveling surface, and forming an annular shape with a diameter smaller than that of the first elastic portion 13. The second elastic portion 14 is provided. In this solid tire, the tread portion 12 is composed of the first elastic portion 13 and the second elastic portion 14 and exhibits different physical properties, so that various performances are improved as compared with the solid tire composed of a single elastic portion. It has been. The second elastic part 14 of the present embodiment is formed to be harder than the first elastic part 13. In such a 1st elastic part 13 and the 2nd elastic part 14, according to the degree of hardness, it becomes easy to exhibit different performance. That is, the first elastic portion 13 enhances the performance of the tread portion 12 such as buffering properties and grip properties, while the second elastic portion 14 enhances the performance of the tread portion 12 such as durability and load resistance. It is configured.

  The 1st elastic part 13 and the 2nd elastic part 14 can be comprised from various elastomers. Examples of the elastomer include urethane elastomer, olefin elastomer, styrene elastomer, silicone rubber, ethylene-propylene rubber, chloroprene rubber, butyl rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, acrylic rubber, natural rubber, and the like. Various elastomers may be used alone or in combination. Among various elastomers, urethane-based elastomers are preferable from the viewpoint that the physical properties of the first elastic portion 13 and the second elastic portion 14 can be easily adjusted and the performance of the tread portion 12 can be easily improved.

  Next, a method for manufacturing a solid tire will be described in detail. The method for manufacturing a solid tire includes a first molding step for molding the first elastic portion 13 and a second molding step for molding the second elastic portion 14.

  As the raw material of the first elastic part 13 and the second elastic part 14, a raw material that changes from a fluid state to an elastomer can be appropriately selected. Specific examples include curable resins and curable rubbers, and for the reasons described above, it is preferable to include a polyurethane prepolymer which is a raw material for urethane elastomers. The polyurethane prepolymer is a polymer obtained by allowing a polymerization reaction of a polyol and an isocyanate to proceed to a predetermined stage. Such a polyurethane prepolymer is cured as the polymerization reaction proceeds, whereby a polyurethane elastomer molded product can be obtained.

  Examples of the polyol constituting the polyurethane prepolymer include ether polyols such as polypropylene glycol (PPG) and polytetramethylene glycol (PTMG), ester polyols such as adipate polyols, polycaprolactone polyols and polycarbonate polyols. . Examples of the isocyanate constituting the polyurethane prepolymer include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), and the like. The polyurethane prepolymer composed of these polyols and isocyanates may be used alone or in a blend of a plurality of types of polyurethane prepolymers.

  In order to accelerate the curing reaction and control the physical properties of the first elastic portion 13 and the second elastic portion 14, the polyurethane prepolymer is preferably blended with a chain extender (curing agent). Examples of chain extenders include diamines such as 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA), 1,4-butanediol (1,4BD), hydroquinone dioxyethyl ether (HQEE), and the like. Diols and the like.

  In the first molding step, the first elastic portion 13 is molded using the cylindrical mold 31 shown in FIGS. 2 (a) and 2 (b). The mold 31 of the present embodiment includes a cylindrical main body 32 and a pair of closing portions 33 that are disk-shaped and close the opening of the main body 32, and the main body 32 and the pair of closing portions. A region surrounded by the portion 33 is configured as a cavity. As shown in FIG. 2B, the raw material 21 of the first elastic portion 13 is injected into the cavity. The mold 31 is configured such that the closing portion 33 is fixed to the main body portion 32 using a fastening member (not shown). Specifically, a through hole is provided in the approximate center of the closing portion 33, and a bolt (not shown) inserted into the through hole is screwed into the nut, whereby the closing portion 33 is fastened to the main body portion 32. ing. When injecting the raw material 21 of the first elastic portion 13, it is preferable to prevent the raw material 21 from adhering to a portion other than the inner peripheral wall of the main body portion 32 as much as possible. The raw material 21 may be injected, for example, from the through hole, or may be injected from the injection hole provided in the vicinity of the center of the main body portion 32.

  In the first molding step, the first elastic portion 13 is molded by rotating the mold 31 into which the raw material 21 of the first elastic portion 13 is injected in the circumferential direction. The rotation of the mold 31 is performed so that the direction of the rotation axis C shown in FIGS. 2A and 2B is along the horizontal direction. With the rotation of the mold 31, the raw material 21 of the first elastic portion 13 flows along the inner peripheral wall of the main body portion 32. For this reason, it is difficult for the raw material 21 of the first elastic portion 13 to adhere to the mold 31 other than the inner peripheral wall of the main body portion 32. And the 1st elastic part 13 is shape | molded because a raw material makes an annular | circular shape with the centrifugal force accompanying rotation of the metal mold | die 31. FIG. In the present embodiment, the mold 31 is rotated with the rotation axis C aligned in the horizontal direction. The angle of the rotation axis with respect to the horizontal plane orthogonal to the direction of gravity is preferably set within 10 degrees, for example.

  When the first elastic portion 13 is molded, the raw material 21 of the first elastic portion 13 may be heated or cooled in the mold 31 as necessary. Such heating or cooling can be performed using heat conduction of the mold 31. For example, when a thermosetting raw material is used as the raw material 21 of the first elastic portion 13, the hardening reaction is started and accelerated by heating the mold 31 using a heating means such as a heater (not shown). Can be made.

  As shown in FIG. 2A, the mold 31 in the first molding step is in contact with a driving roller 34 that is rotationally driven, and is rotated by the rotational driving of the driving roller 34. The drive roller 34 of the present embodiment has a long shape extending along the direction of the rotation axis C of the mold 31 and is configured to contact the outer peripheral walls of the pair of closing portions 33. The drive roller 34 is configured by covering a shaft portion made of a metal material with an outer peripheral portion made of an elastic material (not shown). The outer peripheral portion made of such an elastic material suppresses the slip of the mold 31 that is in contact with the drive roller 34. The driving roller 34 configured in this way is easy to transmit its driving force to the mold 31 and to easily increase the rotational speed of the mold 31. Therefore, the centrifugal force acting by the rotation of the mold 31 can be increased. As a result, uneven thickness of the first elastic portion 13 can be suppressed. The drive roller 34 is connected to a motor (not shown) and is configured to be rotationally driven by the motor.

  A driven roller 35 is juxtaposed on the side of the drive roller 34 of the present embodiment. And the metal mold | die 31 is mounted in the drive roller 34 and the driven roller 35, and the metal mold | die 31 is rotated. By rotating the mold 31 using the driven roller 35 in this way, for example, the resistance associated with the rotation of the mold 31 is reduced as compared with the case where the mold 31 is supported by a support tool other than the driven roller 35. It is rotated in a more stable state. The driven roller 35 of the present embodiment has a long shape extending along the direction of the rotation axis C of the mold 31 and is covered with an outer peripheral portion made of an elastic material, like the drive roller 34.

  As shown in FIG. 3, according to the method of rotating the mold 31 using the rotational drive of the driving roller 34, a plurality of the molds 31 are arranged along the length direction of the driving roller 34. The mold 31 can be rotated simultaneously. In general, since a plurality of solid tires are used as a set, it is very effective from the viewpoint of quality stabilization that the plurality of first elastic portions 13 can be simultaneously performed in the first molding step.

  As shown in FIG. 4A, the first elastic portion 13 is molded in the mold 31 in which the first molding step is completed, in close contact with the inner peripheral wall. In the first molding step of the present embodiment, the first elastic portion 13 is not completely cured but is completed in a semi-cured state.

  In the second molding step, as shown in FIG. 4 (b), the mold 31 in which the first elastic portion 13 is molded is allowed to stand so that the rotation axis C in the first molding step is along the vertical direction. The wheel 11 is arranged at the central part in the mold 31. It is preferable to apply an adhesive to the outer peripheral surface of the wheel 11 from the viewpoint of securing a bonding force with the second elastic portion 14. Next, the raw material of the second elastic portion 14 is injected between the first elastic portion 13 and the wheel 11 in the mold 31 to form the second elastic portion 14. That is, the second elastic portion 14 is formed by filling the raw material of the second elastic portion 14 in a region surrounded by the first elastic portion 13, the wheel 11, and the closing portion 33. Note that when the second elastic portion 14 is formed, the raw material of the second elastic portion 14 may be heated or cooled as necessary, as in the first forming step described above. Further, when the second elastic portion 14 is formed, the mold 31 may be rotated in the same manner as in the first forming step from the viewpoint that the raw material of the second elastic portion 14 is uniformly filled in the region. When the mold 31 is rotated, in order to keep the distance between the wheel 11 and the first elastic portion 13 constant, the mold 31 is moved to the center of the cavity by using, for example, a fastening member that fixes the closing portion 33. Fix to the site.

  As shown in FIG. 4B, in the mold 31 in which the second elastic portion 14 is molded, the wheel 11 and the first elastic portion 13 are integrated via the second elastic portion 14, thereby A solid tire is manufactured. In the second molding step, the semi-cured first elastic portion 13 in the first molding step is also completely cured. At this time, the raw material of the second elastic portion 14 and the raw material 21 of the first elastic portion 13 react with each other at the interface portion thereof, thereby securing the bonding force between the second elastic portion 14 and the first elastic portion 13. Can do.

  Next, the solid tire is removed from the mold 31 to obtain a solid tire, while the mold 31 is used for manufacturing a new solid tire. Moreover, when the unnecessary thing produced | generated from the raw material in each shaping | molding process has adhered to the outer surface of the solid tire and the inside of the metal mold | die 31, the operation | work which removes the unnecessary thing is implemented. At this time, in the first molding step, since the adhesion of the raw material 21 of the first elastic portion 13 to the inside of the mold 31 other than the inner peripheral wall of the main body portion 32 is suppressed, generation of unnecessary materials from the raw material 21 is generated. As a result, for example, the labor of removing such unnecessary materials from the blocking portion 33 is reduced.

  The obtained solid tire is provided in a wheel of an industrial vehicle such as an automatic guided vehicle or a forklift, an automatic warehouse, a multistory parking lot, a transport wheel provided in various manufacturing facilities, a game machine such as a roller coaster or a ferris wheel, and the like. Used as a wheel. Since the solid tire manufactured in this way can easily exhibit different performances based on the second elastic portion 14 and the first elastic portion 13, the degree of freedom in design can be increased. Therefore, it is easy to provide performance suitable for the use of the solid tire, the usage environment, and the like.

The effects exhibited by this embodiment will be described below.
(1) For example, when the mold 31 is rotated so that the direction of the rotation axis C is along the vertical direction, after the raw material existing on the inner wall of the closing portion 33 flows along the inner wall, It flows to the inner peripheral wall of the main body 32 against gravity. In such a flow of the raw material, the raw material tends to adhere and remain on the inner wall of the closed portion 33. Since the mold 31 in the first molding step of the present embodiment is rotated so that the direction of the rotation axis C is along the horizontal direction, the raw material 21 of the first elastic portion 13 is along the inner peripheral wall of the main body portion 32. Fluid. For this reason, it is difficult for the raw material 21 of the first elastic portion 13 to adhere to portions other than the inner peripheral wall of the main body portion 32 in the mold 31. Therefore, it can suppress that an unnecessary material is produced | generated from the raw material 21 of the 1st elastic part 13 in the metal mold | die 31. FIG. As a result, it is possible to reduce the trouble of removing such unnecessary items from the mold 31 or the solid tire. Therefore, it becomes easy to increase the production efficiency of the solid tire having the second elastic portion 14 and the first elastic portion 13. Moreover, since the production | generation of an unnecessary thing is suppressed, it is possible to reduce the loss of a raw material as much as possible, Therefore A yield can be improved.

  (2) The mold 31 of the present embodiment is rotated by a driving roller 34 that contacts the mold 31. For this reason, when the mold 31 is rotationally driven, the trouble of connecting the drive shaft to the mold 31 can be omitted. For this reason, as a result of being able to simplify a 1st shaping | molding process, it is still easier to manufacture the solid tire mentioned above. Further, for example, when the drive shaft is connected to the mold 31 and rotated, it is necessary to provide a connection structure for connecting the drive shaft to the mold 31. According to this method, since the drive shaft connection structure can be omitted, the structure of the mold 31 itself can be simplified. Moreover, as shown in FIG. 3, according to the method of rotating the mold 31 by using the rotational drive of the drive roller 34, it is easy to rotate the plurality of molds 31 at the same time. As a result, the first molding step Can be implemented efficiently and quality can be stabilized.

  (3) In the first molding step, the mold 31 is placed and rotated on the driving roller 34 and the driven roller 35 provided in parallel with the driving roller 34. According to this method, the mold 31 rotated by the rotation of the drive roller 34 is rotated in a stable state by the driven roller 35 that rotates. For this reason, as a result of being able to raise the rotation speed of the metal mold | die 31, the uneven thickness of the 1st elastic part 13 can be suppressed. Therefore, the quality of the solid tire can be improved.

The embodiment may be modified as follows.
The mold 31 may be rotated by bringing the driving roller 34 into contact with the main body 32 in addition to the closing portion 33. Further, the mold 31 may be rotated by bringing the drive roller 34 into contact with only the main body 32.

A plurality of the driving rollers 34 may be arranged side by side, and the mold 31 may be rotated by the plurality of driving rollers 34.
A plurality of the driven rollers 35 may be provided, and the mold 31 may be supported by the plurality of driven rollers 35.

  A support tool that contacts and supports the mold 31 may be used without using the driven roller 35. In this case, for example, by bringing a cylindrical or triangular prism-shaped support tool into contact with the mold 31, even when the mold 31 is supported, the mold 31 can be rotated by driving the drive roll. .

  The outer periphery of the driving roller 34 or the driven roller 35 is not made of an elastic material, and an elastic member is provided around the outer peripheral surface of the mold 31 so that the mold 31 with respect to the driving roller 34 or the driven roller 35 Slip may be suppressed.

Instead of using the driving roller 34, the mold 31 may be rotated by connecting a rotationally driven drive shaft to the center of the closing portion 33, for example.
In the first molding step, the semi-cured first elastic portion 13 is molded, but in the first molding step, the first elastic portion 13 in a completely cured state may be molded. In this case, after performing the application | coating process which apply | coats an adhesive agent to the internal peripheral surface of the 1st elastic part 13, it joins the 1st elastic part 13 and the 2nd elastic part 14 by implementing the said 2nd shaping | molding process. Power can be secured.

  -A 3rd elastic part can also be further provided between the 2nd elastic part 14 and the 1st elastic part 13 by implementing a forming process between the 1st forming process and the 2nd forming process. . In addition, it is preferable to implement the shaping | molding process which shape | molds a 3rd elastic part similarly to the said 1st shaping | molding process.

  -The first elastic part 13 in the solid tire according to the embodiment is formed to be harder than the second elastic part 14, thereby improving the durability of the first elastic part 13 and the buffering property of the second elastic part 14. You may comprise so that it may raise. In addition, as a reference | standard of hardness, the hardness measured with a durometer is mentioned.

-About the 1st elastic part 13 and the 2nd elastic part 14, you may comprise so that physical properties other than hardness may differ. Examples of physical properties other than hardness include dynamic viscoelasticity and surface friction coefficient.
Next, the technical idea that can be grasped from the above embodiment will be described below.

The method of manufacturing a solid tire, wherein the driving roller is covered with an outer peripheral portion made of an elastic material, and the outer peripheral portion is brought into contact with the mold to rotate the mold.
The solid tire is a method for manufacturing a solid tire in which the hardness of the first elastic portion is different from the hardness of the second elastic portion.

  The raw material for the second elastic part and the raw material for the first elastic part include a polyurethane prepolymer, and the second elastic part and the first elastic part in the solid tire are made of a polyurethane elastomer. .

(A) is a side view which shows the solid tire of this embodiment, (b) is the 1b-1b sectional view taken on the line of (a). (A) is a schematic perspective view for demonstrating a 1st shaping | molding process, (b) is the 2b-2b sectional view taken on the line of (a). The schematic perspective view for demonstrating a 1st shaping | molding process. (A) is sectional drawing for demonstrating a 1st shaping | molding process, (b) is sectional drawing for demonstrating a 2nd shaping | molding process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Wheel, 13 ... 1st elastic part, 14 ... 2nd elastic part, 21 ... Raw material, 31 ... Mold, 34 ... Drive roller, 35 ... Driven roller

Claims (3)

In the method for manufacturing a solid tire in which the second elastic portion is provided between the wheel and the first elastic portion having the running surface,
A first molding step of molding the first elastic portion by rotating a cylindrical mold into which the raw material of the first elastic portion is injected in the circumferential direction;
And a second molding step of molding the second elastic part by injecting the raw material of the second elastic part while placing the wheel in a mold in which the first elastic part is molded,
The method of manufacturing a solid tire, wherein the mold in the first molding step is rotated so that a direction of a rotation axis thereof is along a horizontal direction. The first molding step includes
2. The method for manufacturing a solid tire according to claim 1, wherein the mold is brought into contact with a driving roller and the mold is rotated by rotational driving of the driving roller. The first molding step includes
3. The method of manufacturing a solid tire according to claim 2, which is a step of placing the mold on the drive roller and a roller provided in parallel with the drive roller and rotating the mold.

Images