JP2007062939A - Method for manufacturing belt having projection, and belt molding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form projections arranged on a conveying flat belt discontinuously in the width direction without increasing unnecessary man-hour. <P>SOLUTION: An unvulcanized rubber sheet 21', and a canvas 22 are successively attached to an outer circumferential surface 47 of a columnar inner mold 40. An outer mold 50 is arranged so as to surround the inner mold 40. The outer mold 50 consists of a plurality of outer mold pieces 51. A plurality of recesses for molding projections are arranged in the axial direction X in an inner circumferential surface 51B of each outer mold piece 51. Each outer mold piece 51 is displaced inwardly in the radial direction, and the unvulcanized rubber sheet 21' and the canvass 22 are pressed by the outer mold 50. The unvulcanized rubber sheet 21' and the canvass 22 are heated together with the pressurization. A part of the unvulcanized rubber sheet 21' is allowed to flow inside each recess, and the unvulcanized rubber sheet 21' is vulcanized to form a belt sleeve with projections formed on its outer circumferential surface. Next, the outer mold 50 is expanded to release the outer mold 50 from the belt sleeve. Then, the belt sleeve is released from the inner mold 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a belt with protrusions and a belt molding apparatus used in the manufacturing method.

  2. Description of the Related Art Conventionally, a flat belt with a protrusion is used to convey a conveyed item such as a coin in a money handling machine such as an automatic change machine. Such a flat belt with protrusions is manufactured by attaching the protrusions to the belt body with an adhesive, for example.

  Since the flat belt with protrusions conveys the conveyed object by rotating the belt while the conveyed object is locked to the protrusion, a load along the belt conveying surface acts on the protrusion from the conveyed object. Further, when the transported object is caught by an obstacle, for example, a large load may be applied to the protrusion from the transported object. However, the load that acts in this manner is concentrated on the bonding portion between the protrusion and the belt, and in the above-described belt with a protrusion, there is a problem that the protrusion easily peels off from the bonding portion with the belt body. .

  Therefore, in order to improve the durability of the joint portion between the belt main body and the protrusion, it is known that the protrusion and the belt main body are integrally formed by vulcanization molding as described in Patent Document 1. Yes.

In this method, an unvulcanized rubber sheet is wrapped around an inner mold provided with a projection forming groove, a rubber strip is attached to a position corresponding to the groove, and then the rubber is heated and pressurized from the outside. A part of the rubber is caused to flow into the groove, whereby a belt sleeve having a protrusion formed on the inner peripheral surface is obtained. Here, the belt sleeve has to be removed from the inner mold, but the projection forming groove extends from one end to the other end in the axial direction on the outer peripheral surface of the inner mold. Therefore, when the belt sleeve is released in the axial direction, the protrusions are released along the grooves, whereby the belt sleeve can be easily released from the inner die.
JP 10-156961 A

  However, according to the manufacturing method of Patent Document 1, the protrusion formed on the belt sleeve continuously extends from one end to the other end in the axial direction. On the other hand, a plurality of protrusions are usually provided discontinuously in the width direction in the conveying flat belt. In such a case, according to the manufacturing method of Patent Document 1, the protrusions once formed are cut. Thus, discontinuous protrusions must be formed, which increases the number of steps.

  Also, if the groove for forming protrusions is provided discontinuously in the axial direction to form discontinuous protrusions, when the belt sleeve is released in the axial direction, the protrusions are caught on the inner mold, and the belt sleeve is moved to the inner mold. Can not be demolded from.

  Therefore, the present invention has been made in view of such problems, and an object thereof is to provide a manufacturing method capable of providing discontinuous protrusions in the width direction of the belt without increasing the number of steps. To do.

  In the method for manufacturing a belt with protrusions according to the present invention, at least an unvulcanized rubber sheet is mounted in a cylindrical shape on the outer peripheral surface of a columnar inner mold so as to surround the inner mold on which the unvulcanized rubber sheet is mounted. A step of disposing an outer mold provided with a recessed portion for molding a protrusion on the inner peripheral surface, and reducing the diameter of the outer mold, and an unvulcanized rubber sheet by the outer peripheral surface of the inner mold and the inner peripheral surface of the outer mold By heating the unvulcanized rubber sheet, a part of the unvulcanized rubber sheet is caused to flow into the recessed portion and the unvulcanized rubber sheet is vulcanized to form protrusions on the outer peripheral surface. Forming the belt sleeve, and expanding the outer mold to release the outer mold from the belt sleeve, and releasing the belt sleeve from the inner mold. According to such a manufacturing method, when the belt sleeve is released from the outer mold, the outer mold expands in diameter, so that the belt sleeve is released without hooking a protrusion extending radially outward to the outer mold.

  The present invention is applicable, for example, even when the recessed portion is discontinuously provided in the axial direction of the outer mold on the inner peripheral surface of the outer mold. Preferably, when the unvulcanized rubber sheet is narrowed by the inner mold and the outer mold, a plurality of recessed portions are arranged in at least one of the axial direction and the circumferential direction of the outer mold.

  The outer mold is, for example, divided in the circumferential direction by a gap extending from one end to the other end in the axial direction of the outer mold, displaced toward the inside, and reduced in diameter and narrowed toward the outside by narrowing the gap. By doing so, the gap is widened and the diameter is expanded. The gap extends parallel to the axial direction of the outer mold.

  The outer mold is divided into, for example, two or more outer mold pieces by a gap, and each outer mold piece is an arc piece whose inner peripheral surface exhibits an arc, and the center of curvature of the inner peripheral surface is an inner mold axis. Preferably, the curvatures of the inner peripheral surfaces of the outer mold pieces are the same.

  The inner mold may be provided with a canvas in a cylindrical shape inside or outside the unvulcanized rubber sheet.

  The belt molding apparatus according to the present invention is arranged so as to surround a columnar inner mold in which at least an unvulcanized rubber sheet is mounted in a cylindrical shape on an outer peripheral surface, and an inner mold in which an unvulcanized rubber sheet is mounted, An outer mold provided with a recessed portion for molding a protrusion on its inner peripheral surface, a heating means for heating an unvulcanized rubber sheet attached to the inner mold, and reducing or expanding the outer mold Displacement means. In the present invention, the outer mold is reduced in diameter by the displacement means, the unvulcanized rubber sheet is narrowed by the outer peripheral surface of the inner mold and the inner peripheral surface of the outer mold, and the unvulcanized rubber sheet is heated by the heating means. Thus, a part of the unvulcanized rubber sheet is allowed to flow into the recessed portion, and the unvulcanized rubber sheet is vulcanized to form a belt sleeve having protrusions on the outer peripheral surface. Then, after the belt sleeve is molded, the outer mold is expanded by the displacing means so that the belt sleeve is released from the outer mold and the belt sleeve is also released from the inner mold.

  As described above, in the present invention, the protrusions provided discontinuously in the width direction can be formed without increasing the number of man-hours as compared with the normal belt manufacturing. Moreover, since the protrusion in the manufactured belt is formed integrally with the belt main body, it has high durability.

  FIG. 1 is a perspective view showing a usage state of the conveying flat belt according to the present embodiment. FIG. 2 is a longitudinal sectional view of the conveying flat belt on the line II-II in FIG. The transport flat belt 10 according to the present embodiment includes a belt main body 20, and the belt main body 20 includes a rubber layer 21, a canvas 22 serving as a core body of the transport flat belt 10 on the outer peripheral side of the rubber layer 21. Are stacked.

  The belt body 20 is formed in an endless shape, and is provided with a protrusion 11 that protrudes perpendicularly from the outer peripheral surface 20A. The protrusion 11 is provided at a part of the outer peripheral surface 20A in the width direction and at a part of the outer peripheral surface 20A in the longitudinal direction. That is, the protrusion 11 is formed discontinuously in the belt width direction and the longitudinal direction. . Specifically, in the present embodiment, a plurality of protrusions 11 are arranged at equal intervals in the width direction, and a plurality (for example, eight) of protrusions 11 are also arranged at equal intervals in the longitudinal direction. The cross-sectional shape of the protrusion 11 (cross section along the outer peripheral surface 20A) is a rectangle that is long in the width direction.

  The canvas 22 is made of nylon fiber, aramid fiber, polyester fiber, glass fiber, cotton yarn, or a mixed fiber of two or more of these. The canvas 22 is a woven fabric formed by weaving the above fibers, for example, in an endless manner, or a knitted fabric formed by knitting.

  The rubber layer 21 and each protrusion 11 are formed from an elastomer which is an elastic material. For example, as an elastomer component, ethylene-propylene-diene terpolymer blend (EPDM), ethylene-propylene rubber (EPR), hydrogen Nitrile rubber, hydrogenated nitrile rubber added with unsaturated carboxylic acid metal salt, chlorosulfonated polyethylene, chlorinated polyethylene, chloroprene, urethane rubber, epichlorohydrin rubber, acrylic rubber, fluorine rubber, silicone rubber, or A mixture of two or more of these is used.

  The conveying flat belt 10 is used by being wound around two pulleys P so that the conveying surface of the outer peripheral surface 20A is inclined to the upper left in FIG. On the outer peripheral surface 20A of the conveying flat belt 10, a conveyed product C (for example, a coin) is locked to the left side in FIG. Placed. The transporting flat belt 10 is rotated counterclockwise in FIG. 1, and the transported object C is transported while being locked to the protrusions 11 with the rotation.

  The manufacturing method of the flat belt 10 for conveyance which concerns on this embodiment is demonstrated using FIGS. FIG. 3 shows a vulcanization molding apparatus for manufacturing the conveying flat belt 10. FIG. 4 shows the inner mold of the vulcanization molding apparatus.

  As shown in FIG. 3, the vulcanization molding apparatus 30 according to this embodiment includes an inner mold 40 and an outer mold 50 that is disposed so as to surround the inner mold 40 so as to surround a radially outer side while keeping a predetermined distance. Is provided.

  The inner mold 40 is formed of a metal in a substantially cylindrical shape with the axis X as the center, and a passage (not shown) through which the heat medium passes is provided in the inner mold 40, and the heat medium passes through the inner mold 40. The outer peripheral surface 47 of the inner mold 40 is heated. On the upper surface and the lower surface of the inner mold 40, pipes 44 and 45 for sending and receiving the heat medium into and from the inner mold 40 are provided. As the heat medium, for example, warm water, water vapor, oil, or the like is used. As shown in FIG. 4, an unvulcanized rubber sheet 21 ′ is wound around the outer peripheral surface 47 of the inner mold 40, and after being mounted in a cylindrical shape, an endless cylindrical canvas 22 is provided outside thereof. Covered.

  As shown in FIG. 3, the outer mold 50 includes a plurality (eight in this embodiment) of outer mold pieces 51 that are arranged with a predetermined gap 54 therebetween in the circumferential direction thereof. Each of the outer mold pieces 51 is an arc piece that is curved, and the inner peripheral surface 51B is an arc having the same curvature, and the center of curvature coincides with the axis X. That is, the outer mold 50 is configured such that the same cylinder centered on the axis X is equally divided into eight outer mold pieces 41 in the circumferential direction by a gap 54 extending parallel to the axis X direction from the upper end to the lower end. Is done.

  A cylinder 52 is attached to the outer side of each outer mold piece 51 in the radial direction. Each cylinder 52 can displace the entire outer mold piece 51 in the radial direction by fluid pressure that is hydraulic pressure, water pressure, air pressure, steam pressure, or a combination of two or more thereof. As the outer mold piece 51 is displaced in the radial direction, the entire outer diameter of the outer mold 50 is reduced or increased. Since each outer mold piece 51 is a rigid metal, it is displaced in the radial direction by each cylinder 52 without substantially deforming its shape.

  A schematic perspective view of each outer mold piece 51 is shown in FIG. As shown in FIG. 5, the inner peripheral surface 51B of each outer mold piece 51 is provided with a plurality of recessed portions 53 arranged in a line in a direction along the axis X (see FIG. 3). That is, the recessed portion 53 is provided only partially in the direction of the axis X on the inner peripheral surface 51B, in other words, is provided discontinuously in the direction of the axis X. The recessed portions 53 provided at the uppermost and lowermost positions are not connected to the upper end portion 51C and the lower end portion 51D of the inner peripheral surface 51B of the outer mold 50. Each recessed portion 53 is a recessed portion for forming a protrusion and has substantially the same shape as the protrusion 11, and the sectional shape of each recessed portion 53 is a rectangle that is long in the direction of the axis X.

  The recessed portions 53 are arranged in the same manner in any of the outer mold pieces 51. In the state of FIG. 3 and FIG. 6 described later, each outer mold piece 51 includes each recessed portion of one outer mold piece 51. A recessed portion 53 is provided that is disposed on the same circumference as the position where 53 is disposed. Each recessed portion 53 is provided with an air vent hole extending from the bottom surface to the outer peripheral surface of the outer mold piece 51 in order to prevent air from being accumulated in each recessed portion 53 and avoiding molding defects of the protrusions 11. good.

  Next, the vulcanization molding method according to this embodiment will be described with reference to FIGS. In the vulcanization molding apparatus according to this embodiment, after the unvulcanized rubber sheet 21 ′ and the canvas 22 are mounted on the inner mold 40, a heat medium is supplied into the inner mold 40, and the outer peripheral surface 47 of the inner mold 40. Is heated, and heating of the rubber sheet 21 ′ and the canvas 22 is started. Simultaneously with the heating, each cylinder 52 is driven, each outer mold piece 51 is displaced radially inward, and the inner peripheral surface of the outer mold 50 is reduced in diameter. When the outer mold pieces 51 are displaced inward, the inner peripheral surfaces 51 </ b> B are brought into close contact with the canvas 22. Each outer mold piece 51 is further displaced inward in the radial direction after being in close contact with the canvas 22, and the rubber sheet 21 ′ and the canvas 22 are arranged on the inner peripheral surface 51 </ b> B of each outer mold piece 51 and the outer peripheral surface 47 of the inner mold 40. It is pinched by.

  When each outer mold piece 51 is displaced radially inward, the entire outer mold 50 is reduced in diameter, and the gap 54 provided between each outer mold piece 51 is narrowed. As a result, the outer mold pieces 51 gradually approach, but when the outer mold pieces 51 are in close contact with and pressed against the canvas 22, the outer mold pieces 51 may be in contact with each other or may be separated from each other. .

  When the rubber sheet 21 ′ and the canvas 22 are sandwiched and heated by the heat medium, the viscosity of the rubber sheet 21 ′ decreases and the rubber sheet 21 ′ is fluidized. By this fluidization, the rubber sheet 21 ′ is impregnated in the gaps between the fibers of the canvas 22, flows radially outward from the gaps, and flows into the recesses 53. The rubber sheet 21 ′ that has flowed into the recessed portion 53 forms the protrusion 11 in the transporting flat belt 10. The pressing and heating to the rubber sheet 21 ′ and the canvas 22 are continued even after the rubber sheet 21 ′ flows into the recessed portion 53, the rubber sheet 21 ′ is vulcanized and molded, and the rubber sheet 21 ′ is used as the canvas 22. Is vulcanized and bonded. Thereby, a cylindrical belt sleeve 31 having a belt body 20 (see FIG. 2) configured by laminating a canvas 22 on a rubber layer 21 (see FIG. 2) formed by the rubber sheet 21 ′ is obtained. On one surface 31 </ b> A (the outer peripheral surface in FIG. 6) of the belt sleeve 31, a protrusion 11 that protrudes radially outward and is integrally formed with the belt body 20 is formed.

  After the belt sleeve 31 is formed, supply of the heat medium is stopped, supply of a cooling medium (for example, cooling water) is started inside the inner mold 40, and vulcanization is completed. When vulcanization is completed, each outer mold piece 51 is displaced radially outward by each cylinder 52, the inner peripheral surface of the outer mold 50 is expanded, and the belt sleeve 31 is released from each outer mold piece 51. The When the belt sleeve 31 is released from each outer mold piece 51, each outer mold piece 51 is displaced in the direction in which the protrusion 11 protrudes, so that each protrusion 11 of the belt sleeve 31 is caught by each outer mold piece 51. It can be released.

  When the belt sleeve 31 is released from the outer mold piece 51, next, a force in the direction of the axis X is applied to the belt sleeve 31, and the belt sleeve 31 is released from the inner mold 40. Here, since no protrusion or the like is provided on the inner peripheral surface of the belt sleeve 31, the belt sleeve 31 can be easily released from the inner mold 40. The belt sleeve 31 is cut to a predetermined width after being released from the mold, so that a conveying flat belt 10 as shown in FIGS.

  As described above, in the present embodiment, the protrusions provided discontinuously in the width direction can be formed without increasing the number of man-hours as compared with normal belt manufacturing. Further, since the protrusions formed in this way are formed integrally with the belt body, the protrusions have higher durability than when the protrusions are attached to the belt body with an adhesive, for example.

  In the present embodiment, the cross-sectional shape of the recessed portion 53 is rectangular, but can be appropriately changed according to the shape of the protrusion 11 such as an elliptical shape or a circular shape.

  Moreover, although the inner peripheral surface 51B of the outer mold 50 provided with the recessed portion is formed of a rigid metal, it may be formed of, for example, resin or rubber. In addition, the outer mold 50 is formed by a plurality of outer mold pieces 51, in which the same cylinder is divided by the gap 54. However, the outer mold 50 surrounds the inner mold 40, and the inner peripheral surface 51B can be reduced in diameter and expanded. For example, the configuration is not particularly limited, and may be configured by an integral outer mold or a combination of rubber and a mold.

It is a perspective view of the flat belt in the use condition concerning this embodiment. It is a longitudinal cross-sectional view of the flat belt on the II-II line of FIG. It is a top view of a vulcanization molding device. It is a perspective view of the inner mold | type equipped with the rubber sheet and canvas. It is a perspective view of each outer mold piece. It is a top view of a vulcanization molding device for showing a process in which a rubber sheet and a canvas are compressed by an outer mold and an inner mold and a belt sleeve is molded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Conveyance flat belt 11 Protrusion 21 'Unvulcanized rubber sheet 21 Rubber layer 22 Canvas 31 Belt sleeve 40 Inner mold 47 Outer surface 50 Outer mold 51 Outer mold piece 51B Inner surface 52 Cylinder 53 Recessed part

Claims (9)

At least an unvulcanized rubber sheet is mounted in a cylindrical shape on the outer peripheral surface of a columnar inner mold, and a protrusion is molded on the inner peripheral surface so as to surround the inner mold on which the unvulcanized rubber sheet is mounted. A step of arranging an outer mold provided with a recessed portion of
The diameter of the outer mold is reduced, the unvulcanized rubber sheet is narrowed by the outer peripheral surface of the inner mold and the inner peripheral surface of the outer mold, and the unvulcanized rubber sheet is heated to heat the unvulcanized rubber sheet. A step of allowing a part of the rubber sheet to flow into the recessed portion, vulcanizing the unvulcanized rubber sheet, and forming a belt sleeve having protrusions formed on an outer peripheral surface;
And a step of releasing the outer mold from the belt sleeve to release the outer mold and releasing the belt sleeve from the inner mold.   The method for manufacturing a belt with protrusions according to claim 1, wherein the recessed portion is provided discontinuously in the axial direction of the outer mold on the inner peripheral surface of the outer mold.   2. The belt with protrusions according to claim 1, wherein when the unvulcanized rubber sheet is narrowed by the inner mold and the outer mold, a plurality of the recessed portions are arranged in at least one of an axial direction and a circumferential direction of the outer mold. Manufacturing method.   The outer mold is divided in the circumferential direction by a gap extending from one end to the other end in the axial direction of the outer mold, displaced toward the inside, and the gap is narrowed to reduce the diameter, and toward the outside. The method for manufacturing a belt with protrusions according to claim 1, wherein the gap is expanded and the diameter is expanded by being displaced.   The method of manufacturing a belt with protrusions according to claim 4, wherein the gap extends in parallel to the axial direction.   The method for manufacturing a belt with protrusions according to claim 4, wherein the outer mold is divided into two or more outer mold pieces by the gap.   Each of the outer mold pieces is an arc piece whose inner peripheral surface forms an arc, and the center of curvature of the inner peripheral surface coincides with the axis of the inner mold, and the curvature of the inner peripheral surface of each of the outer mold pieces. The method for manufacturing a belt with protrusions according to claim 6, wherein the two are identical to each other.   The method for manufacturing a belt with protrusions according to claim 1, wherein a canvas is attached to the inner mold in a cylindrical shape inside or outside the unvulcanized rubber sheet. A columnar inner mold in which at least an unvulcanized rubber sheet is mounted in a cylindrical shape on the outer peripheral surface;
An outer mold which is arranged so as to surround the inner mold on which the unvulcanized rubber sheet is mounted, and which is provided with a recessed portion for molding a protrusion on the inner peripheral surface thereof;
Heating means for heating the unvulcanized rubber sheet attached to the inner mold;
Displacement means for reducing or expanding the outer mold;
The outer mold is reduced in diameter by the displacement means, the unvulcanized rubber sheet is narrowed by the outer peripheral surface of the inner mold and the inner peripheral surface of the outer mold, and the unvulcanized rubber sheet is heated by the heating means. Thus, a part of the unvulcanized rubber sheet is allowed to flow into the recessed portion, the unvulcanized rubber sheet is vulcanized, and a belt sleeve having protrusions formed on the outer peripheral surface is formed, and the belt After the sleeve is molded, a belt molding apparatus characterized in that the outer mold is expanded in diameter by the displacing means to release the belt sleeve from the outer mold and to release the belt sleeve from the inner mold.

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