JP2005254753A - Hollow elastic body and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a hollow elastic body which is used as an exterior object of an elastic pole, a cone type signage implement, and the like and which can give a color coding pattern easily and to provide the hollow elastic body which can assure visibility which is excellent over a long period of time. <P>SOLUTION: Unvulcanized rubbers colored in different colors are extruded in the shape of a string respectively from different extrusion molding machines. These rubber strings 9 and 14 are put in parallel and twisted around the periphery of a mandrel 10 spirally so that the hollow body of unvulcanized rubber is formed, and the vulcanizing molding of this body is carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hollow elastic body made of vulcanized rubber, and is particularly used for marking a separation line between upper and lower roadways or a boundary line between a roadway and a sidewalk, and other signs such as parking partitions for parks and streets. The present invention relates to a hollow elastic body that can be suitably used as an exterior body of an elastic column or as a cone-type marker used on the road or at a construction site.

Conventionally, as the elastic column, as shown in Patent Document 1, an elastic column including a hollow exterior body, a core body inserted into the hollow portion, and an elastic material filled in the hollow portion is known. Yes. The exterior body is constituted by an elastic body in order to keep the damage small when a pedestrian accidentally collides or a vehicle comes into contact.
JP 2000-282428 A

  The hollow exterior body can be prepared by an injection molding vulcanization method in which an unvulcanized rubber is injected between an external mold and an internal mold to heat vulcanize, or inside an extruded unvulcanized rubber tube. A method is known in which air pressure is applied to the unvulcanized rubber and pressed against an outer shape regulating die to heat vulcanize.

  However, since these methods can use only a single color of unvulcanized rubber as a raw material, the surface of the exterior body can be obtained only in a single color, resulting in a problem that the design is not interesting. It was.

  Moreover, from the viewpoint of the marker, it is preferable to apply a color-coded pattern on the surface of the exterior body using a plurality of colors in order to further improve the visibility, but in this case, a coloring process with a paint or the like is separately required, There was a problem that this led to an increase in cost.

  Further, when an exterior body having a colored layer formed on the surface by the coloring step is used as an elastic column, the elastic column is exposed to wind, rain, sunlight, exhaust gas, or the like, so that the surface is contaminated in a short time. Therefore, when the surface of the elastic column is cleaned in order to remove dirt, the colored layer is peeled off, and the base is exposed to make the appearance worse.

  Furthermore, the elastic column is constantly in contact with the vehicle, and a lot of scratches are generated on the surface. Even in such a case, the problem that the colored layer peeled off and the landscape of the elastic column was damaged occurred. The above-mentioned problems occur in the cone-type marker as well, and it has been desired to solve these problems.

  Therefore, in the present invention, a hollow elastic body used for an outer body of an elastic column, a cone-type marker, etc., and providing a method for producing a hollow elastic body that can be easily color-coded, It aims at providing the hollow elastic body which can ensure the visibility which was excellent over the long term.

  In order to solve the above-mentioned problems, in the present invention, a plurality of rubber cords made of unvulcanized rubber are colored in different colors, and the rubber cords are arranged in parallel, and spiral around the mandrel. It is characterized in that a hollow body of unvulcanized rubber is formed by wrapping it around and vulcanized.

  According to the above method, since a plurality of colored rubber cords having different colors are used, it is possible to form a color-coded pattern at the same time when forming the elastic body without coloring the elastic body surface separately. It becomes.

  The hollow elastic body may be constituted by a rubber string that is wound entirely, or a rubber string may be used for a part thereof. When the rubber string is used as a part of the elastic body, other parts may be formed in advance, joined to the rubber string, and then vulcanized and integrated.

  The hollow elastic body obtained in this way is provided with a strip pattern colored by a plurality of colors spirally on the whole or a part of its outer periphery, and exhibits excellent visibility. Further, the hollow elastic body is formed with a belt-like pattern by winding a string-shaped body made of an elastic body and fixing the adjacent string-shaped bodies.

  In other words, the hollow elastic body is not simply formed with a colored layer on its surface, but the rubber itself constituting the elastic body is colored. Even when used in the above, by cleaning the surface of the elastic body, only the dirt can be removed without peeling off or deteriorating the formed pattern, and good visibility can be ensured over a long period of time.

  Here, coloring a plurality of rubber string-like bodies in different colors means that the rubber string-like bodies are colored so that any one of lightness, saturation or chromaticity is different, and adjacent rubber string-like bodies It is only necessary that the boundary of can be recognized by color coding.

  The rubber string-like body used in the present invention can be obtained by rolling unvulcanized rubber into a sheet shape and then cutting it into a string shape. The unvulcanized rubber is directly stringed from an extrusion molding machine. When extruded, a rubber string can be easily obtained.

  The rubber string may be extruded from a separate extruder for each color. For example, when forming a two-color strip pattern, the rubber string is extruded from two extruders, and when forming a three-color strip pattern, the rubber string is formed from three extruders. Extrude.

  That is, unvulcanized rubber colored in different colors is extruded from different extruders into a string shape, and these string-like bodies are arranged side by side in a spiral manner around the mandrel outer periphery. A hollow body may be formed and vulcanized.

  However, in this case, if the rubber string immediately after being extruded from the extruder is simply wrapped around the mandrel, the rubber string may hang down by its own weight when heated and vulcanized. There is a possibility that a so-called sagging may occur.

  Therefore, in the present invention, when a rubber string is extruded from an extruder and wound around the mandrel, the temperature of the mandrel is set lower than the extrusion temperature of the rubber string, and the tension is applied to the rubber string. The rubber string was wound spirally around the mandrel while hanging.

  Thereby, the rubber string-like body extruded from the extruder contracts by coming into contact with a mandrel having a temperature lower than that of the rubber string-like body. At this time, the rubber string is wound around the mandrel in a state where the residual stress to be contracted remains by pulling the rubber string around the mandrel.

  Therefore, even if the rubber string is heated during vulcanization, the rubber string can be kept firmly in contact with the outer periphery of the mandrel due to residual stress, and sagging can be prevented. In order to wind around the mandrel while leaving the residual stress to be contracted on the rubber string, the hardness of the rubber string (durometer A hardness defined in JIS K6253, hereinafter referred to as “durometer A hardness”) is 40. It is preferable to set it to -80 degrees.

  An unvulcanized hollow body is formed by winding a rubber string to form a spiral convex portion by a rubber string on the surface, but when vulcanizing, use a vulcanization can, The unvulcanized elastic body may be accommodated in the can together with the mandrel and vulcanized. By doing in this way, while forming uneven | corrugated shape on the surface, the hollow elastic body by which the strip | belt-shaped pattern color-coded for every rubber string-like body was helically given can be obtained. That is, it is possible to obtain a hollow elastic body having both excellent visibility due to the belt-shaped pattern formed in a spiral shape and excellent design and texture due to the uneven portion.

  In addition, the rubber string is wound around the mandrel while pressing with a roller or the like so that the surface of the elastic body becomes smooth, or the hollow body is accommodated in the mold and the surface of the hollow body is pressed with the mold. Of course, an elastic body having a flat surface can be finally obtained.

  If the manufacturing method of the hollow elastic body which concerns on this invention is used, it will become possible to shape | mold the external appearance of an elastic body into the shape corresponding to the shape of a mandrel by selecting the shape of a mandrel variously. For example, if the cross-sectional shape of the mandrel is an ellipse, a hollow elastic body having an elliptical cross-sectional shape can be obtained. If the cross-sectional shape of the mandrel is a polygonal shape such as a quadrangle, pentagon, or hexagon, the same A hollow elastic body having a cross-sectional shape can be obtained, and can be suitably used as an exterior body of an elastic column. Further, when the shape of the mandrel is conical, a cone-type elastic body can be obtained, and it can be suitably used as a marker installed on the road or construction site.

  The rubber string may have any shape such as a circular, elliptical, polygonal shape such as a triangle or a quadrangle, but in particular, the cross-sectional shape is rectangular, that is, the rubber string has a belt-like appearance. Is preferably used.

  That is, when a belt-shaped body, which is a rubber string, is wound around a mandrel, one side surface (narrow surface) of the belt-shaped body abuts on the mandrel to form the inner peripheral surface of the elastic body, and the other side surface is elastic. When wound so as to constitute the outer peripheral surface of the body, the surface of the wide band (wide surface) is superimposed on the surface of the adjacent band, ensuring a sufficient bonding area between the adjacent band This makes it possible to obtain an elastic body with excellent strength. Furthermore, the width of the belt-like pattern can be widened, and visibility can be improved.

  In the present invention, as a method for producing an elastic body, a plurality of rubber string-like bodies made of unvulcanized rubber are colored in different colors, and these rubber string-like bodies are arranged side by side in a spiral manner around the mandrel. A hollow body of unvulcanized rubber is formed by wrapping, and this is vulcanized, so it is possible to spirally apply a band-like pattern colored by multiple colors on the outer peripheral surface, and hollow elasticity with excellent visibility You can get a body.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In this embodiment, the case where the exterior body 2 of the elastic column 1 is manufactured as a hollow elastic body will be described. FIG. 1 is a cross-sectional view showing an elastic column 1 using an exterior body 2 according to the present invention. The elastic column 1 includes a cylindrical bag-shaped exterior body 2, a core body 3 that is internally provided in a central portion of the exterior body 2, and a cushioning material 4 that is filled in the internal space of the exterior body 2.

  The core 3 is a long rod-shaped or tubular synthetic resin. In the present embodiment, a tubular object is used, its tip is opened, and the inside is filled with the buffer material 3. The material of the core body 3 is selected according to the required strength and resilience, but in the present embodiment, a polyethylene pipe having an outer diameter of 60 mm and a length of 1000 mm is used, and is embedded in the exterior body 2. The length is set to 700 mm, and the length of the portion buried in the ground is set to 300 mm.

  The buffer material 4 is composed of an elastic body, and for example, a non-foamed elastic body such as polyurethane rubber or polyurethane elastomer, or a foamed elastic body such as foamed polyurethane can be used.

  The exterior body 2 has an overall length of 850 mm, and is composed of a dome-shaped tip portion 2a and a cylindrical body portion 2b connected to the tip portion 2a. An uneven portion 7 is formed which includes a spiral convex portion 5 continuous in the axial direction and a spiral concave portion 6 formed between the convex portions 5. The thickness of the exterior body 2 is about 4.5 mm from the inner surface to the concave portion 6, and the thickness from the inner surface to the convex portion 5 is about 6 mm. The height difference between the convex portion 5 and the concave portion 6 is about 1 .5 mm, and the pitch between the protrusions is about 4 mm.

  Next, the manufacturing method of the exterior body 2 as a hollow elastic body is demonstrated. FIG. 2 is a schematic view showing a method for manufacturing the exterior body 2. First, an unvulcanized rubber compounded with a colorant is put into an extrusion molding machine, and from a slit 8a provided in an extrusion die 8 of the extrusion molding machine, a strip-shaped rubber string 9 (hereinafter referred to as the first color) The first rubber string is extruded with a width of 8.5 mm and a thickness of 3 mm.

  Similarly, from a slit 8a provided in an extrusion die 8 of another extrusion molding machine, a belt-like rubber string body 14 (hereinafter referred to as a second rubber string body) colored in the second color is 8.5 mm wide. Extrude at a thickness of 3 mm. In the present embodiment, natural rubber having a durometer A hardness of 55 degrees is used as a raw material for the rubber strings 9 and 14.

  Next, the first rubber string-like body 9 and the second rubber string-like body 9b are pulled out from the extrusion die 8 in a state where they are arranged in parallel, and one side surface (narrow surface) of each string-like body is drawn out. 9a and 14a are in contact with the mandrel 10 to form the inner peripheral surface of the outer package 2, and the other side surfaces 9a and 14a form the outer peripheral surface of the outer package 2 and are wound around the outer periphery of the mandrel 10.

  The mandrel 10 is provided so as to be rotatable and movable in the axial direction. By moving the mandrel 10 at a constant speed, the first rubber string body 9 and the second rubber string body 14 are gradually moved in the axial direction. While being shifted to each other, the surfaces (wide surfaces) 9b and 14b are sequentially spirally wound around the outer periphery of the mandrel 10 so as to partially overlap each other, so that the two colors of the first color and the second color are separated. The exterior body 2 having the spiral band pattern 15 thus formed is formed. In the present embodiment, two types of the first and second colors are used for the rubber string, but the present invention is not limited to this, and three or more (three colors) or more rubber string can be used. is there.

  When the first rubber string 9 and the second rubber string 14 are wound around the mandrel 10, the temperature of the mandrel 10 is set to be lower than the extrusion temperature of the rubber strings 9 and 14, and the rubber When the string-like bodies 9 and 14 are wound around the outer periphery of the mandrel 10, both the rubber string-like bodies 9 and 14 are tensioned. As a result, the rubber cords 9 and 14 are cooled on the mandrel 10, and an internal stress that tightens the mandrel 10 is generated inside the rubber cords 9 and 14. Accordingly, the rubber cords 9 and 14 are firmly held in close contact with the mandrel 10, and there is no risk of sagging even if heat is applied during vulcanization.

  The shape of the mandrel 10 can be selected in various ways, whereby the exterior body 2 having a shape corresponding to the shape of the mandrel 10 can be obtained. In the present embodiment, as the mandrel 10, as shown in FIG. 3, a body 10a having a cylindrical shape and a tip 10b having a rounded shape is used. A protrusion 10 c is formed on the rotation shaft at the tip of the mandrel 10.

  This protrusion 10c is provided on the surface of the mandrel 10 so as to be able to protrude and retract. When the first rubber string 9 and the second rubber string 14 are wound around the mandrel 10, the protrusion 10c is set in a protruding posture. It is used as a starting point for winding the rubber strings 9 and 14.

FIG. 4 is a partially enlarged view showing cross sections of the first rubber string 9 and the second rubber string 14 wound around the mandrel. When the rubber cords 9 and 14 are wound around the mandrel 10, first, the first rubber cord 9 and the second rubber cord 14 are wound in parallel around the protrusion 10c. Then, the mandrel 10 is moved in the direction of arrow A while rotating.
The thickness of the outer package 2 is determined by the rotational speed of the mandrel 10 and the moving speed in the direction of arrow A. That is, when the rubber cord-like bodies 9 and 14 are wound around the mandrel body 10a, the rubber cord-like bodies 9 and 14 are reduced when the mandrel moving speed in the direction of arrow A is slowed while the rotation speed of the mandrel 10 is kept constant. Rises, that is, in the state where one side surface 9a and 14a of the rubber cords 9 and 14 is in contact with the mandrel 10, the inclination angle between the width direction of the rubber cords 9 and 14 and the mandrel axial direction is growing. And the thickness of the exterior body 2 obtained in this way becomes thick, and the strip | belt-shaped pattern 15 becomes a thing with a narrow width | variety of a strip | belt.

  Conversely, when the moving speed in the direction of the arrow A is increased, the rubber straps 9 and 14 are in the sleeping state, that is, the one side surfaces 9a and 14a of the rubber straps 9 and 14 are in contact with the mandrel 10. Thus, the angle of inclination between the width direction of the rubber cords 9 and 14 and the mandrel axial direction becomes small. And the thickness of the exterior body 2 obtained in this way becomes thin, and the strip | belt-shaped pattern 15 becomes a thing with a wide width | variety of a strip | belt.

  In this embodiment, by setting the moving speed of the mandrel slightly faster, the string-like bodies 9 and 14 are wound around the mandrel 10 in a standing state, the thickness of the exterior body 2 is about 6 mm, and the first color And the width B of the spiral belt-like pattern 15 color-coded by the two colors of the second color is set to be about 4 mm.

  At this time, the first rubber string 9 and the second rubber string 14 are formed on the outer periphery of the mandrel 10 from the spiral convex portion 5 and the spiral concave portion 6 formed between the convex portions 5. An uneven portion 7 is formed. That is, it is possible to obtain the exterior body 2 (hollow elastic body) having both excellent visibility due to the strip-shaped pattern 15 formed in a spiral shape, and excellent design and texture due to the uneven portion 7.

  FIG. 5 is a cross-sectional view showing a state in which the unvulcanized exterior body 2 is formed on the outer periphery of the mandrel 10. As described above, by adjusting the rotation speed and the movement speed of the mandrel 10, it is possible to form the exterior body 2 having a predetermined thickness on the outer periphery of the mandrel having various shapes. The exterior body 2 thus formed on the mandrel 10 is then vulcanized and molded together with the mandrel 10 in a vulcanizing can. Vulcanization conditions may be determined as appropriate. In this embodiment, vulcanization was performed under conditions of 140 ° C. × 35 minutes.

  After the vulcanization molding, the protrusion 10c of the mandrel 10 is immersed in the mandrel 10, and the outer package 2 is removed from the mandrel 10. At this time, an air hole (not shown) is formed at the tip of the exterior body 2 by immersing the protrusion 10c into the mandrel 10, whereby the exterior body 2 can be smoothly demolded.

  After removing the mold, the outer package 2 is closed by filling the air hole formed at the tip with rubber or resin, and then the core 3 is mounted on the outer package 2 to a predetermined position with the tip facing downward. By filling the exterior body 2 with the buffer material 4 and solidifying it, the elastic column 1 shown in FIG. 6 can be obtained.

[Second Embodiment]
FIG. 7 is a perspective view of an elastic column showing a second embodiment of the present invention. In this embodiment, only the body 2b of the exterior body 2 is formed by winding the rubber string 9, and separately from this, a dome-shaped cap 11 that has been pre-cured and molded is joined to the body 2b, and then added. It is characterized by being integrated by sulfuration, and the other configuration is the same as that of the first embodiment.

  When the cap 11 is separately formed as in the present embodiment, for example, the smooth surface portion 13 for sticking the reflective sheet 12 to the cap 11 can be formed in advance, and the reflective sheet is securely attached to the exterior body 2. It becomes possible to stick.

[Third Embodiment]
FIGS. 8 and 9 are views showing a third embodiment of the present invention, and FIG. 8 is a partially enlarged view showing cross sections of the first rubber string body 9 and the second rubber string body 14 wound around the mandrel. FIG. 9 is a perspective view of the outer package after molding.

  In the present embodiment, the size of the first rubber string 9 and the second rubber string 14 to be used is larger than the string of the first embodiment (15 mm in width and 4 mm in thickness, respectively), and When the rubber cords 9 and 14 are wound around the mandrel 10, the width of the band 15 is increased by increasing the moving speed of the mandrel 10, and the surface of the unvulcanized exterior body is smoothed with a roller. The other features are the same as those of the first embodiment.

  That is, in the present embodiment, when the rubber cord-like bodies 9 and 14 are wound around the mandrel body 10a, the mandrel moving speed is set to be higher than that in the first embodiment with the rotation speed of the mandrel 10 being constant. The rubber straps 9 and 14 are in a sleeping state, that is, the inclination angle between the width direction of the rubber straps 9 and 14 and the axial direction of the mandrel 10 is small. The rubber string-like bodies are alternately stacked spirally along the mandrel 10 in a state where the pitch between the rubber string-like bodies is widened.

  When the pitch between the rubber string-like bodies is widened while the rubber string-like bodies 9 and 14 are lying, the thickness of the exterior body 2 becomes thinner than when the rubber string-like bodies are standing up. , Because the rubber straps 9 and 14 used in the first embodiment are larger in size than the rubber straps 9 and 14 used in the first embodiment, as a result, the thickness of the exterior body 2 is 6 mm, the same as that produced in the first embodiment. However, as shown in FIG. 9, it is possible to obtain the outer package 2 having a band-shaped pattern width C of about 11 cm, which is larger than the width B (see FIGS. 4 and 8) of the band-shaped pattern 15 in the first embodiment. .

  As described above, by appropriately adjusting the size of the rubber string wound around the mandrel 10 and the rotation speed and movement speed of the mandrel 10, the thickness of the obtained hollow elastic body and the width of the belt-like pattern are arbitrarily changed. It becomes possible.

[Fourth Embodiment]
FIG. 10 is a diagram showing a fourth embodiment of the present invention. The present embodiment is characterized in that the mandrel 10 has a conical shape, and a cone-shaped marker is manufactured as a hollow elastic body, and the other configuration is the same as that of the third embodiment.

  That is, in the present embodiment, as shown in FIG. 10, a hollow body obtained by alternately spirally winding the outer peripheral first rubber string-like body 9 and the second rubber string-like body 14 of the conical mandrel 10. The cone-shaped marker (hollow elastic body) 16 can be obtained by vulcanization forming.

  In the above embodiment, the color combination of the first rubber string body 9 and the second rubber string body 14 is not particularly limited. A black combination is preferred.

  Moreover, the elastic column obtained in the said embodiment is equipped with the outstanding bending resistance. That is, in the case of forming a color-coded pattern in a conventional elastic column, it is necessary to form a colored layer on the surface of the exterior body with a paint or the like. When an external force is applied to the elastic column, the exterior body is added. Since the stretch rate of the vulcanized rubber is different from that of the colored layer, there is a problem that the colored layer is cracked or peeled off.

  On the other hand, since the elastic column using the exterior body according to the present invention does not need to form a foreign material layer such as a colored layer on the surface of the exterior body, the above problem does not occur. Specifically, after applying an external force to the elastic column to bend 45 degrees, it was restored to its original state after the external force was removed, and the bending test was repeated. In the case of the coated column), the surface layer crack occurred when it was repeatedly bent 10 times, whereas in the elastic column using the exterior body according to the present invention, there was no problem even if the bending was repeated 1000 times, It was confirmed that it was excellent in performance.

Sectional drawing which shows the elastic column using the exterior body of 1st Embodiment of this invention Schematic which shows the manufacturing method of the exterior body which concerns on this invention The figure which shows the external appearance of the mandrel used in 1st Embodiment. The elements on larger scale which show the cross section of the rubber string wound around the mandrel in 1st Embodiment Sectional drawing which shows the state in which the unvulcanized exterior body (hollow body) in 1st Embodiment was formed The perspective view which shows the elastic pillar using the exterior body in 1st Embodiment The perspective view which shows the elastic pillar using the exterior body of 2nd Embodiment. The elements on larger scale which show the cross section of the rubber string wound around the mandrel in 3rd Embodiment The perspective view which shows the elastic pillar using the exterior body of 3rd Embodiment The perspective view which shows the cone-type marker of 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic pillar 2 Exterior body 2a Tip part 2b Body part 3 Core body 4 Buffer material 5 Spiral convex part 6 Spiral concave part 7 Concave part 8 Extrusion die 9 1st rubber string-like body 10 Mandrel 11 Cap 12 Reflective sheet 13 Smooth surface part 14 Second rubber string 15 Strip pattern 16 Cone-type marker

Claims (7)

A plurality of rubber cords made of unvulcanized rubber are colored in different colors, and in a state where these rubber cords are arranged in parallel, the hollow body of unvulcanized rubber is wound around the mandrel in a spiral shape. A method for producing a hollow elastic body, which is formed and vulcanized. Unvulcanized rubber colored in different colors is extruded from different extruders into a string, and these rubber strings are arranged in parallel, spirally wound around the mandrel, and unvulcanized rubber hollow A method for producing a hollow elastic body, comprising forming a body and vulcanizing and molding the body. The method for producing a hollow elastic body according to claim 1 or 2, wherein the vulcanization molding method uses a vulcanization can. 4. The method for producing a hollow elastic body according to claim 1, wherein the hollow elastic body is an outer body of an elastic column or a cone-shaped marker. An elastic body made of vulcanized rubber having a hollow inside, wherein a belt-like pattern colored by a plurality of colors is spirally applied to the whole or a part of the outer periphery thereof. . The hollow elastic body according to claim 5, wherein the belt-like pattern is formed by winding a string-shaped body made of an elastic body and fixing an adjacent string-shaped body. The hollow elastic body according to claim 5 or 6, wherein the hollow elastic body is used as an outer body of an elastic column or a cone-type marker.

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