JP2012162937A - Connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connector having excellent visibility.SOLUTION: A connector comprises an elastic body having a curvature shape with one end portion and another end portion which contains EPDM as a main component, and a connection member having a chain shape composed of a plurality of connected annular bodies which is embedded in the elastic body in a curved state such that the annular bodies are not fixed to the elastic body and a part of the annular body is exposed from each of the end portion and the other end portion to form a connecting part. At least one part of the connection member embedded in the elastic body is visible from at least one part of the surface of the elastic body.

Description

  The present invention relates to a connector for connecting two members such as a bridge girder and a pier (abutment).

  Conventionally, as a connecting tool for connecting two members such as a bridge girder and a pier (abutment), for example, as in Patent Document 1, the connecting member is elastic in an elastic body that is curved in a substantially U shape in a side view. There is known a connector that is embedded along the shape of the body and in which an end of the connecting member is exposed from an elastic body.

  In a connecting tool like patent document 1, it is calculated | required that the state of the connection member embedded in the elastic body can be confirmed easily by simple means, such as visual observation.

JP-A-2005-326022

  The present invention has been made in consideration of the above circumstances, and an object thereof is to provide a connector having excellent visibility.

  The connector according to claim 1 has a curved shape and has one end and another end, an elastic body containing EPDM as a main component, and a plurality of annular bodies connected to form a chain, and the elasticity A connecting portion that is embedded in the body in a curved state, the plurality of annular bodies are not fixed to the elastic body, and a part of the annular body is exposed from each of the one end and the other end. And at least a part of the connecting member embedded in the elastic body is configured to be visible from at least a part of the surface of the elastic body.

  Since the elastic body is configured to contain EPDM as a main component, excellent visibility and weather resistance are exhibited. Here, “EPDM” refers to an ethylene-propylene-conjugated diene copolymer. Details of the elastic body such as EPDM and other components that can be used in combination will be described later.

  The connector according to claim 1 is configured such that at least a part of the connecting member embedded in the elastic body is visible from at least a part of the surface of the elastic body. Here, “at least a part of the connecting member is visible” means that the presence in the elastic body and the approximate distance from the surface of the elastic body can be visually confirmed for at least a part of the connecting member. That means. In the following description, being visible is also referred to as having visibility as appropriate.

  As described above, since at least a part of the connecting member embedded in the annular body is visible from at least a part of the surface of the elastic body, the embedded state of the connecting member inside the elastic body, the surface property of the connecting member At least a part of the internal state of the elastic body that can affect the performance of the coupler, such as changes and the presence of bubbles and contaminants mixed inside the elastic body, can be easily confirmed visually.

  In addition, the application of EPDM in an elastic body can provide better weather resistance than when other components are applied as the main component of the elastic body.

  In the connecting member, the connecting portion connected to the connection object is configured such that a part of the annular body is exposed from each of the one end and the other end of the elastic body. And the some annular body which comprises the said connection part is made non-adherent with the elastic body.

  EPDM exhibits excellent visibility and weather resistance, but is a material with low adhesiveness. However, since the annular body and the elastic body in the present invention are non-adherent, the visibility is high like EPDM, and adhesion A material having low properties can be applied as a main component in the elastic body.

  Here, “non-adhesion” means that the annular body and the elastic body can be separated from each other. Both the case where the annular body and the elastic body are in close contact with each other and the case where there is a separation portion are included. Including. Therefore, the annular body constituting the connecting portion can be easily moved with respect to the elastic body, and when connecting the connecting portion to the connection object, the distance between the connecting portions is changed by moving the connecting portion. The mounting distance can be easily adjusted. By making the whole connecting member non-adhered to the elastic body, no peeling occurs between the connecting member and the elastic body, so that a stable buffer characteristic can be obtained. In addition, since the annular body and the elastic body are non-fixed, good impact resistance can be continuously obtained even when a plurality of impacts are applied to the coupler.

  The connector according to claim 2 is configured such that at least a part of the annular body coupled to the annular body constituting the coupling portion is visible from each of the one end portion and the other end portion of the elastic body.

  From each of the one end and the other end of the elastic body, at least a part of the annular body connected to the annular body constituting the connecting portion is visible, even when it is necessary to cut the elastic body, The annular body connected to the annular body constituting the connecting portion is not exposed from the inside of the elastic body.

  The connection tool according to claim 3 is configured such that the entire connection member embedded in the elastic body is visible from the surface of the elastic body.

  As described above, since the whole of the plurality of annular bodies embedded in the elastic body is configured to be visible from the surface of the elastic body, the embedded position of the connecting member in the elastic body and the change in the properties of the surface of the connecting member The details of the internal state of the elastic body that can affect the performance of the coupler, such as the presence of air bubbles and contaminants mixed in the elastic body at the time of manufacture, can be easily confirmed visually.

  In the connector according to claim 4, the entire connecting member is plated for rust prevention. In the connector of the present invention, a plurality of annular bodies constituting the connecting member are not fixed to the elastic body, and EPDM, which is a material that does not need to consider adhesiveness, is applied as a main component included in the elastic body. Therefore, the entire linking member can be subjected to rust prevention treatment without considering the adhesiveness between the linking member and the elastic body.

  In this way, the connecting member, which has been plated for rust prevention as a whole, is embedded in the elastic body, so that after the connecting member is embedded in the elastic body, the connecting portions exposed from both ends of the elastic body are rust-prevented. The troublesome work of performing the processing is eliminated, and the productivity can be improved. Moreover, since no organic solvent is used in the manufacturing process, the environmental load is small.

  As described above, according to the present invention, it is possible to provide a connector having excellent visibility.

It is a perspective view which shows the coupling tool which concerns on embodiment of this invention. (A) which shows the coupling tool which concerns on embodiment of this invention is a side view, (B) is a top view. It is a perspective view which shows the state by which the bridge girder and the bridge pier were connected with the connection tool which concerns on embodiment of this invention. It is a side view which shows the state with which the bridge girder and the bridge pier were connected with the connection tool which concerns on embodiment of this invention. It is a perspective view which shows the state which is moving the other end connection part of the connector which concerns on embodiment of this invention. It is a side view which shows the coupling tool which concerns on the modification of embodiment of this invention. It is a side view which shows the coupling tool which concerns on the other modification of embodiment of this invention.

  First, an elastic body which is one of the characteristic components in the connector of the present invention will be described, and then an embodiment of the connector of the present invention will be described with reference to the drawings.

[Elastic body]
The elastic body in the present invention is an elastic body containing EPDM as a main component.

<EPDM>
EPDM is an ethylene-propylene-conjugated diene copolymer. EPDM is contained as a rubber component in the elastic body.

  EPDM is included as a main component in the elastic body. Here, in this specification, “comprising EPDM as a main component” means that 75% by mass or more of EPDM is EPDM with respect to the rubber component contained in the elastic body.

  EPDM can be synthesized by copolymerizing a copolymer component containing ethylene, propylene, and a conjugated diene monomer by a conventional method.

  Although it does not restrict | limit especially as a conjugated diene monomer used for the synthesis | combination of EPDM, Arbitrary conjugated diene monomers represented by dicyclopentadiene, ethylidene norbornene, 1, 4-hexadiene, etc. can be used.

  EPDM may be modified with maleic acid or the like.

  As EPDM, a commercial item can also be used, for example, EP24, EP35, and EP96 (all are brand names) etc. which can be obtained from JSR Corporation.

  The rubber component contained in the elastic body may be only EPDM, or other rubber components may be used in combination as long as the effects of the present invention are not impaired. From the viewpoint of visibility and weather resistance, the rubber component contained in the elastic body is more preferably EPDM only.

<Crosslinking agent>
In the elastic body, the rubber component containing EPDM is preferably crosslinked by a crosslinking agent.

  Examples of the crosslinking agent include sulfur, organic peroxides, resin crosslinking agents, and the like. From the viewpoint of visibility, the crosslinking agent is preferably an organic peroxide.

  When the rubber component containing EPDM is crosslinked using sulfur, 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass of sulfur is used with respect to 100 parts by mass of the rubber component. .

As the organic peroxide that can be used as a crosslinking agent, those normally used in this field can be blended. Specific examples of the organic peroxide include, for example, dicumyl peroxide, benzoyl peroxide, 1,1-bis (t-butylperoxy) -3,5,5-trimethylcyclohexane, diisobutyryl peroxide, cumylper Oxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, Di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylper Oxyneoheptanoate, t-hexylperoxy Valate, t-butyl peroxypivalate, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate , Disuccinic acid peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide , T-butylperoxy-2-ethylhexanoate, di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, dibenzoyl peroxide, 1,1-di (t-butylperoxy) ) -2-Methylcyclohexane, 1,1-di (t-hexylperoxy) -3,3 -Trimethylcyclohexane, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) ) Cyclohexyl) propane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t -Butyl peroxyisopropyl monocarbonate, t-butyl peroxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-di-methyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxy Oxyacetate, 2,2-di- (t-butylperoxy) butane, t- Tilperoxybenzoate, n-butyl 4,4-di- (t-butylperoxy) valerate, di (2-t-butylperoxyisopropyl) benzene, di-t-hexyl peroxide, 2,5-dimethyl- 2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, etc., among these, In the invention, di (2-t-butylperoxyisopropyl) benzene, dicumyl par Kisaido, 2,5-dimethyl-2,5-di (2-ethyl hexanoyl peroxy) hexane can be suitably used.
These organic peroxides can be used individually by 1 type or in mixture of 2 or more types.

  When the rubber component containing EPDM is crosslinked using an organic peroxide, the organic peroxide is preferably used in an amount of 1 to 10 parts by weight, and 2 to 8 parts by weight, based on 100 parts by weight of the rubber component. Is more preferable.

<Other ingredients>
The elastic body in the present invention may contain other components other than EPDM, other rubber components that can be used in combination, and a crosslinking agent as long as the effects of the present invention are not impaired. It is more preferable that the elastic body in the present invention does not contain other components. Examples of the other components include contaminating anti-aging agents (amine-based and imidazole-based), colored plasticizers (aromatic oil, naphthenic oil) and the like.

<Preparation of elastic body forming composition>
The elastic body-forming composition can be suitably prepared by weighing a predetermined amount of a rubber component containing EPDM, a crosslinking agent, and other components and kneading them with a closed mixer.
A commercial item can also be used as a composition for elastic body formation. As this commercial item, TUEP-901 (brand name) etc. which can be obtained from ESC Kasei Co., Ltd. are mentioned, for example.

  Below, the connector of embodiment of this invention is demonstrated according to drawing.

  The connection tool 10 of this embodiment is used as a bridge fall prevention tool, and connects a bridge girder and a bridge pier as a connection object.

  As shown in FIGS. 1-3, the coupling tool 10 of this embodiment is provided with the rubber body 12 which contains EPDM as a main component as an elastic body with a circular cross section and curved in a substantially U shape in a side view. . The cross-sectional shape of the rubber body 12 is not limited to a circle, and may be an ellipse or a polygon. The rubber body 12 has a U-shaped intermediate portion 12A, an inclined portion 12B extending in a direction away from both ends of the intermediate portion 12A, and one end portion 12C that is bent so as to be parallel to each other from the inclined portion 12B. And the other end 12D. A connecting member 14 is embedded in the rubber body 12.

  The connecting member 14 has a chain shape in which five annular bodies 13 are crossed and connected to each other, and is embedded along the U-shape of the rubber body 12. Each of the annular bodies 13 is formed in an annular shape having a circular cross section with a long hole formed in the center. A central annular body 13A arranged at the center of the five annular bodies 13 is embedded in the central portion 12A of the rubber body 12, and a side annular body embedded in the inclined portion 12B of the rubber body 12 is embedded in the central annular body 13A. 13B are linked with an angle θ.

  As shown in FIG. 2A, a gap a is provided at the intersection between the central annular body 13A and each side annular body 13B, and between the end portions of the side annular body 13B, A gap b is formed. Here, for the convenience of explanation, the expression “gap” is used. However, even in these gaps, a rubber composition (a composition for forming an elastic body) containing EPDM as a main component is filled and integrated with the rubber body 12. It has become. Here, by embedding a reinforcing layer (for example, a fiber layer) in the rubber body of the gap, or changing the material such as making the rubber body of the gap different from the elastic modulus of other rubber bodies, The buffer function can be increased or decreased.

  One end annular body 13C is linked to the side annular body 13B on one end side of the connecting member 14, and the other end annular body 13D is linked to the side annular body 13B on the other end side. The one-end annular body 13C and the other-end annular body 13D are erected in parallel with each other from the one-end portion 12C and the other-end portion 12D, and substantially half of the longitudinal direction is exposed, and the one-end connection portion 13E and the other-end connection portion 13F. Are each configured. The one end connecting portion 13E and the other end connecting portion 13F are connected to the bracket 22 of the bridge girder 16 that is to be connected.

  The connecting member 14 is plated for rust prevention on the entire outer surface. As plating for rust prevention, plating of zinc, an alloy of zinc and aluminum, an alloy of zinc, aluminum and magnesium, or the like can be used. In this embodiment, the entire outer surface of the connecting member 14 is plated for rust prevention. However, a configuration in which a part of the connecting member 14 is plated or a structure in which the connecting member 14 is not plated may be used. Good.

  Here, the connecting member 14 is not coated with an adhesive for fixing to the rubber body 12. For this reason, the connecting member 14 is not fixed to the rubber body 12 and is embedded in the rubber body 12. As a result, the tensile force from the rubber body 12 is not applied to the one-end annular body 13C and the other-end annular body 13D that are partially exposed from the rubber body 12 when a force for moving the rubber body 12 is applied. The rubber body 12 can be separated. Therefore, it can be easily moved relative to the rubber body 12 as compared with the case where the rubber body 12 is fixed.

  FIG. 3 shows a state where the bridge girder 16 and the bridge pier 17 are connected by the connector 10 of the present embodiment. Note that the bridge girders 16 may be coupled to each other by the coupling tool 10 of the present embodiment.

  As shown in FIG. 4, the connector 10 according to the present embodiment is configured to be connected by a pin 24 to a bracket 22 attached to the side surfaces of the bridge girder 16 and the bridge pier 17. The bracket 22 includes an attachment portion 22A in which two triangular plates are arranged in parallel, and a base portion 22B on which the attachment portion 22A is erected. The bracket 22 has a base portion 22 </ b> B fixed to the bridge girder 16 and the bridge pier 17. In the connector 10, the one end connecting portion 13E and the other end connecting portion 13F are inserted between the plates of the attaching portion 22A, the pin hole 22H and the attaching hole 13H of the one end connecting portion 13E, and the pin hole 22H and the other end connecting portion 13F. The pin 24 is passed through and fixed to the mounting hole 13H.

(Manufacturing method of coupling tool)
Next, the manufacturing method of the coupler 10 which concerns on this form is demonstrated.

  First, a connecting member 14 in which five annular bodies 13 are linked is manufactured, and in the plating step, the entire connecting member 14 is rust-proofed by any one of zinc, an alloy of zinc and aluminum, and an alloy of zinc, aluminum and magnesium. Plating for.

  Next, in the embedding step, the rubber body 12 is formed outside the plated connecting member 14. In the embedding process, an upper and lower mold having a shape corresponding to the rubber body 12 forming a parting line in the longitudinal direction of the rubber body 12 is used. First, an uncrosslinked rubber composition half of the rubber body 12 is set in the lower mold, and the connecting member 14 is in a curved state thereon, and the one end connecting portion 13E and the other end connecting portion 13F are removed from the rubber body 12. Set in the lower mold so that it is exposed to the outside. Note that an adhesive for adhering to the rubber body 12 is not applied to the connecting member 14.

Next, an uncrosslinked rubber composition of the remaining half of the rubber body 12 is set on the connecting member 14 and an upper mold is set and crosslinked while pressing to obtain the connector 10.
In addition, the preparation method of a rubber composition can apply the matter mentioned above as a preparation method of the composition for elastic body formation. Thereby, the rubber body 12 is formed outside the connecting member 14 without the connecting member 14 and the rubber body 12 being fixed.

(Function and effect)
Next, the operation of the connector 10 according to this embodiment will be described.

  In the connector 10 according to the present embodiment, a connecting member 14 is embedded in a rubber body 12 having excellent visibility containing EPDM as a main component, and at least a part of the embedded connecting member 14 is made of the elastic body. It is configured to be visible from at least a part of the surface. For this reason, the embedding position and state of the connecting member 14 inside the rubber body 12, changes in the surface properties of the connecting member 14, bubbles and foreign matters mixed in the rubber body 12 during manufacturing, etc. are affected. The state of the inside of the body 12 that can be given can be easily confirmed visually. The entire connecting member 14 is preferably visible from the surface of the rubber body 12.

  Moreover, since the connection tool 10 is used for connection of outdoor structures such as a bridge girder and a pier (abutment), weather resistance is also required. The application of EPDM to the rubber body 12 can provide better weather resistance as compared with a rubber body applied with other rubber components as a main component, thereby further extending the life of the connector 10.

  It is desirable that at least a part of the side annular body 13B is visible from the one end connecting portion 13E and the other end connecting portion 13F of the rubber body 12 in the connector 10. When the connecting tool 10 is connected to the bridge girder 16 and the bridge pier 17 by the one end connecting portion 13E and the other end connecting portion 13F, it may be necessary to scrape the rubber body 12. In this case, the exposure of the side annular body 13B from the inside of the rubber body 12 may impair the performance of the connector 10, but at least one of the side annular body 13B from each of the one end portion 12C and the other end portion 12D. Since the portion is visible, even when the rubber body 12 needs to be cut, the side annular body 13B is not exposed from the inside of the rubber body 12.

  When connecting the bridge girder 16 and the pier 17 with the connector 10, the operator fixes the one end connecting portion 13 </ b> E to the bracket 22 of the bridge girder 16 using the pin 24 and the other end connecting portion 13 </ b> F to the bracket of the pier 17. It fixes to 22 using the pin 24. FIG. At this time, when the distance between the pin hole 22H of the bracket 22 of the bridge pier 17 and the bridge girder 16 does not coincide with the distance between the attachment hole 13H of the one end connecting portion 13E and the other end connecting portion 13F, the one end connecting portion 13E and the other end A force is applied to the connecting portion 13F to move it relative to the rubber body 12, and the mounting distance is adjusted. As shown in FIG. 5A, a force F1 is applied to the other end connecting portion 13F (the other end annular body 13D) so as to approach the one end connecting portion 13E, and the position with respect to the rubber body 12 is shifted (embedding). By rotating in the hole, the distance between the other end connecting portion 13F and the one end connecting portion 13E can be shortened. Similarly, the one end connecting portion 13E can be moved by applying a force to shorten the distance between the other end connecting portion 13F and the one end connecting portion 13E. Further, as shown in FIG. 5B, a force F2 is applied to the other end connecting portion 13F (the other end annular body 13D) so as to be separated from the one end connecting portion 13E, and the position with respect to the rubber body 12 is shifted. By (rotating in the embedding hole), the distance between the other end connecting portion 13F and the one end connecting portion 13E can be increased. Similarly, the one end connecting portion 13E can be moved by applying a force to increase the distance between the other end connecting portion 13F and the one end connecting portion 13E.

  In the connector 10 of this embodiment, the rubber body 12 and the connecting member 14 are not fixed, so that the operator applies force to the one end connecting portion 13E and the other end connecting portion 13F, so that the rubber body 12 It can be easily moved and the mounting distance can be adjusted.

  When the pier 17 is shaken and the force in the direction of arrow A in FIG. 2 acts on the linking tool 10 in the event of an earthquake or the like, the linking tool 10 attached as described above has the one end annular body 13C and the other end annular body 13D. Force is applied in the direction away from each other. For this reason, the angle θ of the rubber body 12 is reduced, a bending resistance force is generated, and the buffer function works so that the bridge girder 16 and the bridge pier 17 are pulled by the elastic force and shape characteristics of the rubber body 12. At this time, since the rubber in the gap a is compressed, the cushioning function is also exerted by the rubber filled between the annular bodies 13.

  On the other hand, when the girder 16 approaches and a force in the direction opposite to the arrow A acts on the connector 10, the one end annular body 13C and the other end annular body 13D try to approach each other. For this reason, the angle θ of the rubber body 12 is increased and a bending resistance force is generated, and a buffering function for separating the bridge girder 16 and the pier 17 by the elastic force and shape characteristics of the rubber body 12 works.

  At this time, in this embodiment, the portion embedded in the rubber body 12 of the connecting member 14 is not bonded to the rubber body 12. Therefore, due to the displacement shown in the direction of arrow A in FIG. 2, the first load acting on the connector 10 does not cause the bond between the connecting member 14 and the rubber body 12 to be peeled off, thereby obtaining a stable buffer characteristic. Can do.

  In the present embodiment, since the entire connecting member 14 is plated for rust prevention in the plating step of the manufacturing process of the connector 10, to the one end connecting portion 13 </ b> E and the other end connecting portion 13 </ b> F that are exposed portions. Rust of the exposed part can be easily prevented without performing the complicated work of performing anticorrosion coating.

  Moreover, in the connection tool 10 of this embodiment, since the connection member 14 and the rubber body 12 are not fixed, separation of the connection member 14 and the rubber body 12 is facilitated and recycling is facilitated.

  Moreover, in this embodiment, in order to make the connection member 14 and the rubber body 12 non-fixed, the connection member 14 is plated, but the connection member 14 and the rubber body 12 may be non-fixed by other methods. Good

  Moreover, although this embodiment demonstrated the coupling tool 10 using the connection member 14 comprised by the five annular bodies 13, you may use the connection member of another structure. For example, as shown in FIG. 6, it is good also as a structure of the coupling tool 20 which embedded the connection member 24 comprised by the seven annular bodies 13 in the rubber body 12, and was able to respond | correspond to a big displacement amount. Moreover, as shown in FIG. 7, it is good also as a structure of the connection tool 30 which embedded the connection member 34 comprised of the three annular bodies 13 in the block-shaped rubber body 12 with a small curvature.

  Moreover, the connection tool of this invention is not limited to the bridge | bridging fall prevention tool which connects the bridge girder 16 and the bridge girder 16 or the bridge girder 16 and the bridge pier 17, It is applicable also to the connection tool which connects another connection object.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to this embodiment. Moreover, in the following Examples or Comparative Examples, “phr” refers to parts by mass of each compounding component with respect to 100 mass of the rubber component.

[Example 1]
The connector of Example 1 having the shape shown in FIG. 1 was produced as follows.

-Composition for forming an elastic body The composition 1 for forming an elastic body for forming a rubber body was prepared by kneading the components shown in the following composition 1 according to a conventional method.
<Composition 1>
・ EPDM (Product name: EP24, manufactured by JSR Corporation) 100 phr
・ Crosslinking agent: 2,5-dimethyl-2,5-di (t-butylperoxy) hexane 7 phr

-Connection member The chain | strand used as a connection member in a connector was prepared, and the galvanization process was performed with respect to this chain | strand.

-Upper and lower molds As molds used for the production of the coupler, upper and lower molds having a shape corresponding to the rubber bodies that form parting lines in the longitudinal direction of the rubber bodies were used.

<Manufacture of connecting tool>
First, an uncrosslinked elastic body forming composition for forming a half of a rubber body is filled in a lower mold.
Next, on the elastic body forming composition filled in the lower mold, the connecting member (chain subjected to galvanization treatment) is in a curved state, and one end connecting portion and the other end connecting portion are Set so that it is exposed to the outside from the rubber body.
Next, an uncrosslinked elastic body-forming composition for forming the remaining half of the rubber body is set on the connecting member, and an upper mold is set and crosslinked while pressing.

  By burying the galvanized chain in the rubber body so that the connecting portions connected to the brackets of the girders to be connected are exposed from both ends of the curved rubber body as described above. The connector of Example 1 was produced.

[Example 2]
Example 1 except that the elastic body forming essential composition 1 used in Example 1 was changed to the elastic body forming essential composition 2 prepared by kneading each component shown in the following composition 2 in accordance with a conventional method. Similarly, the connector of Example 2 was obtained.
<Composition 2>
・ EPDM (Product name: EP24, manufactured by JSR Corporation) 100 phr
・ Crosslinking agent: Sulfur 1phr
・ Vulcanization accelerator: Tetramethylthiuram monosulfide 1phr
・ Vulcanization accelerator: Tetramethylthiuram disulfide 2phr

[Comparative Example 1]
The elastic body forming composition “TUEP-901” used in Example 1 was changed to a silicon rubber composition (product name: SR-6326, manufactured by Takehara Rubber Co., Ltd.). Thus, a connector of Comparative Example 1 was obtained.

[Evaluation]
About the couplers of Examples 1 and 2 and Comparative Example 1 obtained above, the inside was visually observed from the surface of the rubber body, and the visibility was evaluated. As a result, an organic peroxide was used as EPDM and a crosslinking agent. In the coupler of Example 1 using the elastic body-forming composition, the inside can be confirmed up to about 5 cm from any part of the rubber body surface, and the entire chain embedded in the rubber body It was possible to visually grasp both the existence and the approximate distance from the rubber body surface to the chain.
Moreover, in the coupler of Example 2 using the elastic body-forming composition containing EPDM and sulfur as a crosslinking agent, the inside can be confirmed up to about 3 cm from any part of the rubber body surface. The presence of the entire chain embedded in the film could be grasped visually.
On the other hand, in the coupling tool of Comparative Example 1 using the silicon rubber composition, the coupling member could not be visually confirmed from the rubber body surface.

DESCRIPTION OF SYMBOLS 10 Connection tool 12 Rubber body 12C One end part 13C One end annular body 13E One end connection part 13 Ring body 13D Other end annular body 13F Other end connection part 14 Connection member 16 Bridge girder 17 Bridge pier 20 Connection tool 24 Connection member 30 Connection tool 34 Connection member

Claims (4)

An elastic body that is curved and has one end and the other end, and contains EPDM as a main component;
A plurality of annular bodies are connected to form a chain shape, embedded in a curved state in the elastic body, the plurality of annular bodies are not fixed to the elastic body, and from each of the one end and the other end A connecting member having a connecting part formed by exposing a part of the annular body;
And a connection tool in which at least a part of the connection member embedded in the elastic body is visible from at least a part of the surface of the elastic body.   The connection tool according to claim 1, wherein at least a part of the annular body connected to the annular body constituting the connection portion is visible from each of one end and the other end of the elastic body.   The coupling tool according to claim 1 or 2, wherein the whole of the coupling member embedded in the elastic body is visible from the surface of the elastic body.   The connector according to any one of claims 1 to 3, wherein the entire connecting member is plated for rust prevention.