JP2015190158A - Pipe connection joint structure and pipe connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure for connecting pipes that enhances safety and simplifies work procedures.SOLUTION: A pipe connection joint structure 1 for connecting pipes 6 includes a tubular elastic body 20 of tubular form that is made of an elastic material and is inserted into the pipe 6, and a bolt member 30 and a nut member 40 that serve as a compression part for elastically deforming the tubular elastic body 20, in such a way to have the tubular elastic body 20 swell in the direction to enlarge the diameter by compressing the tubular elastic body 20 in the direction of tube axis. The tubular elastic body 20 is pressed against the inner peripheral surface 6b of the pipe 6 as the tubular elastic body 20 is elastically deformed due to compression in the direction of tube axis by the compression part when the tubular elastic body 20 has been inserted in the pipe 6, and a fixing effect for connecting the pipes 6 arises between the pipe 6 and the tubular elastic body 20, due to frictional resistance between the outer peripheral surface 21 of the tubular elastic body 20 and the inner peripheral surface 6b of the pipe 6.

Description

  The present invention relates to a pipe connection joint structure and a pipe connection method used for connecting pipes constituting, for example, a stair railing.

  2. Description of the Related Art Conventionally, as a joint structure used for connecting pipes, for example, there is a joint structure that can arbitrarily cope with a predetermined angle formed by pipes connected to each other at a corner portion of a handrail composed of pipes. As an example of such a joint structure, there is a structure in which pipes are connected to each other via a pair of joint members that are connected and fixed so as to form an arbitrary angle with a predetermined shaft member such as a bolt as a rotation axis (for example, (See Patent Document 1).

  An example of a conventional joint structure will be specifically described with reference to FIG. As shown in FIG. 12, the joint member 110 constituting the conventional joint structure has a substantially cylindrical outer shape as a whole, and is a substantially hemispherical portion on one side in the cylinder axis direction and is a bolt as a shaft member. It has the connection part 111 connected by (head screw) 109, and has the cylindrical part 112 inserted in the edge part of the pipe 106 in the other side of a cylinder axial direction. Between the pipes 106 connected to each other, the pair of joint members 110 insert the cylindrical portion 112 into the end portion of each pipe 106 and connect the connecting portions 111 in a state of being joined from the flat surface portion 111a side in the hemispherical outer shape. A pair of pipes 106 are connected to each other by connecting and fixing the connecting portions 111 to each other by a bolt 109 screwed so as to pass through.

  In addition, each joint member 110 is configured such that a bolt (round countersunk screw) 121 penetrating the peripheral wall of the pipe 106 from the outside of the pipe 106 is screwed into a portion of the cylindrical portion 112 inserted into the end portion of the pipe 106. Fixed to. An O-ring 122 is externally fitted to the cylindrical portion 112 of the joint member 110 that is inserted into the pipe 106.

  In such a joint structure, when the joint members 110 are fixed to each other by the bolt 109, the axial direction of the bolt 109 screwed into the hemispherical connecting portion 111 can be rotated with respect to each other. For this reason, the connection angle between the joint members 110 is arbitrarily adjusted by the rotation of the bolt 109 around the axis. By adjusting the connection angle between the joint members 110, it is possible to arbitrarily correspond to a predetermined angle formed by the pipes 106 connected to each other.

JP 2007-297825 A

  According to the conventional joint structure as described above, due to the configuration for fixing the joint member 110 to the pipe 106, there are the following problems. First, the head of the bolt 121 screwed into the cylindrical portion 112 of the joint member 110 from the outside of the pipe 106 becomes a protruding portion that protrudes from the surface of the pipe 106. The presence of the protruding portion on the surface of the pipe 106 in this way is not preferable in terms of safety because there is a concern about hand contact with the protruding portion when the pipe 106 is used as a handrail. In particular, it is important to ensure the safety of handrails for children, elderly people, and people with physical disabilities who need sufficient safety considerations, because handrails are used more frequently.

  Moreover, there is a problem that it takes a lot of work. Specifically, according to the conventional joint structure as described above, depending on the arrangement direction of the pipe 106 that defines the angle formed by the pipes 106 connected to each other at the construction site where the pipe 106 is arranged. After adjusting the relative rotational position of the pipe 106 and the joint member 110 inserted into the pipe 106, drilling is performed to form a screw insertion hole for the bolt 121 in the pipe 106 and the joint member 110. May be. According to such a construction procedure, it is necessary to perform drilling processing for each connecting portion of the pipes 106 in accordance with the state of arrangement of the pipes 106 at the construction site, which makes the work complicated and laborious. It will be.

  Further, there is a possibility that rattling occurs due to poor tightening of the bolt 121 for fixing the joint member 110 to the pipe 106. Such looseness due to poor tightening of the bolt 121 is not preferable from the viewpoint of safety, particularly in a handrail.

  Furthermore, exposure of the heads of the bolts 121 to the surface of the pipe 106 may cause a decrease in appearance design.

  The present invention has been made in view of the circumstances as described above, and provides a joint structure for pipe connection and a pipe connection method capable of easily ensuring safety and simplifying construction work. The purpose is to provide.

  The joint structure for pipe connection according to the present invention is a joint structure for pipe connection used for connecting pipes, has a cylindrical outer shape, is made of an elastic material, and is inserted into the pipe. Compression that elastically deforms the cylindrical elastic body so that the cylindrical elastic body expands in a direction in which the cylindrical elastic body expands by compressing the elastic body and the cylindrical elastic body in the cylindrical axial direction of the cylindrical elastic body And the cylindrical elastic body is inserted into the pipe by the elastic deformation of the cylindrical elastic body accompanying the compression in the cylindrical axis direction by the compression section of the cylindrical elastic body in a state of being inserted into the pipe. Fixing for connecting the pipes between the pipe and the cylindrical elastic body by frictional resistance between the outer peripheral surface of the cylindrical elastic body and the inner peripheral surface by being brought into pressure contact with the inner peripheral surface The effect is obtained.

  In the joint structure for connecting pipes according to the present invention, the compression portion includes a bolt member that penetrates the cylindrical elastic body in the cylindrical axis direction, and a screw portion that protrudes from the cylindrical elastic body of the bolt member. A nut member to be joined, and the cylindrical elastic body is moved into the cylinder by relative proximity movement of the nut member and the head of the bolt member with relative rotation of the bolt member and the nut member. It compresses in the axial direction.

  Further, the joint structure for connecting pipes according to the present invention further includes a joint member that is attached to and connected to the end of the other pipe to be connected to the end of the pipe, It is fixed to the end of the pipe by a fixing action.

  Further, in the joint structure for pipe connection according to the present invention, the cylindrical elastic body has a chamfered portion at at least one corner portion among corner portions formed by the outer peripheral surface and both end surfaces in the cylindrical axis direction. Is.

  The pipe connection method according to the present invention is a pipe connection method used for connecting pipes, and uses a cylindrical elastic body having a cylindrical outer shape, made of an elastic material, and inserted into the pipe. The cylindrical elastic body is expanded in a direction in which the cylindrical elastic body expands by compressing the cylindrical elastic body in a state of being inserted into the pipe in a cylindrical axial direction of the cylindrical elastic body. The cylindrical elastic body is pressed against the inner peripheral surface of the pipe by elastic deformation of the cylindrical elastic body, and the frictional resistance between the outer peripheral surface of the cylindrical elastic body and the inner peripheral surface is used. The fixing action for connecting the pipes is obtained between the pipe and the cylindrical elastic body.

  In the pipe connection method according to the present invention, a bolt member is passed through the cylindrical elastic body along the cylindrical axis direction, and a nut member is screwed into a protruding portion of the bolt member from the cylindrical elastic body. The cylindrical elastic body is compressed in the cylinder axial direction by relatively rotating the bolt member and the nut member so that the nut member and the head of the bolt member are relatively close to each other. It is.

  According to the present invention, safety can be easily ensured and construction labor can be simplified.

It is a figure which shows the example of application of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is an exploded view which shows the structure of the pipe connection part containing the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a top view which shows the pipe connection part containing the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a side view which shows the pipe connection part containing the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a figure which shows the structure of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a longitudinal section showing the composition of the joint structure for pipe connection concerning one embodiment of the present invention. It is a figure of the axial view view which shows the structure of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is an exploded view showing the composition of the joint structure for pipe connection concerning one embodiment of the present invention. It is explanatory drawing about the effect | action of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is explanatory drawing about the usage method of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a figure which shows the other application example of the joint structure for pipe connection which concerns on one Embodiment of this invention. It is a figure which shows the conventional joint structure for pipe connection.

  The present invention relates to a joint structure for connecting pipes used to connect pipes to each other by pressing a cylindrical elastic body, which is an elastic body having a cylindrical outer shape, from the cylinder axis direction while being inserted into an end portion of the pipe. The cylindrical elastic body is expanded in diameter by elastic deformation and compressed, and the cylindrical elastic body is brought into pressure contact with the inner peripheral surface of the pipe by the expansion action, thereby generating friction between the cylindrical elastic body and the pipe. Resistance (frictional force) is used as a fixing action for connecting pipes together. Thus, the present invention is intended to improve safety, simplify construction work, and improve appearance design in the joint structure for connecting pipes. Embodiments of the present invention will be described below.

  First, an application example of a joint structure for connecting pipes according to the present embodiment (hereinafter simply referred to as “joint structure”) will be described with reference to FIG. As shown in FIG. 1, the joint structure 1 according to the present embodiment includes a staircase 3 provided along a predetermined wall surface 2 and a handrail 5 provided on a plane 4 such as a landing that continues to the staircase 3. It is used to connect the pipes 6 that are the main body of the handrail 5. The pipes 6 are connected to each other by a pipe connecting portion 8 configured by a pair of joint structures 1. That is, the joint structure 1 is provided for each pipe 6 that is connected to each other, and constitutes a pipe connection portion 8 together with the joint structure 1 that is provided on the partner pipe 6 to be connected. In the present embodiment, the pipe 6 is a tubular member having a circular cross-sectional shape.

  In the example shown in FIG. 1, the joint structure 1 includes an inclined pipe 6 </ b> A disposed obliquely along the inclination of the stairs 3 among the pipes 6 constituting the handrail 5, and a horizontal disposed horizontally along the plane 4. In the corner portion 5a formed by the pipe 6B, it is used to connect the inclined pipe 6A and the horizontal pipe 6B which are arranged so as to form a predetermined angle with each other. The pipe 6 is supported with respect to the wall surface 2 by a plurality of brackets 7 provided at appropriate intervals along the extending direction of the pipe 6.

  As shown in FIGS. 2 to 4, the pipe connecting portion 8 according to the present embodiment is configured by a joint structure 1 provided for each pipe 6 connected to each other. The pipe connecting portion 8 connects the pipes 6 through a pair of joint members 10 that are connected and fixed so as to form an arbitrary angle with respect to the connecting bolt 9 that functions as a shaft member. The connecting bolt 9 is a hexagon socket head cap bolt having a cylindrical head portion 9b in which a hexagonal hole portion 9a is formed on one end face. However, as the connecting bolt 9, for example, other bolt members such as a hexagon socket countersunk bolt or a bolt having a cross hole in the head are appropriately adopted.

  The joint member 10 is attached to the end of the pipe 6, and is interposed between the end of the attached pipe 6 and the end of the mating pipe 6 to be connected. The joint member 10 has a substantially cylindrical outer shape as a whole, and has a connecting portion 11 which is a substantially hemispherical portion and is connected by a connecting bolt 9 on one side in the cylindrical axis direction. On the side, there is a cylindrical portion 12 that is a portion continuous with the end of the pipe 6. Between the pipes 6 that are connected to each other, the pair of joint members 10 has a mating surface 12a formed on the side opposite to the connecting portion 11 side of the cylindrical portion 12 in contact with the end surface 6a of each pipe 6 and is substantially hemispherical. The connecting portions 11 are connected and fixed by connecting bolts 9 and nuts 9X that are screwed so as to pass through the connecting portion 11 in a state of being joined from the flat surface portion 11a side in the shape of the shape, thereby connecting the pair of pipes 6 to each other. .

  Here, a bolt through hole 11 c through which the connecting bolt 9 is passed is formed in the connecting portion 11 of the joint member 10. The bolt through hole 11c is formed in the connecting portion 11 of the joint member 10 at a position along the radial direction in the hemispherical shape along the outer shape of the connecting portion 11 in a direction perpendicular to the flat surface portion 11a. A fitting hole portion 11d into which the head portion 9b of the connecting bolt 9 or the nut 9X is fitted is formed on the opposite side of the bolt through hole 11c from the flat portion 11a side. That is, in the example shown in FIG. 2, the head 9b of the connecting bolt 9 is fitted into the fitting hole 11d of one joint member 10 (on the right side in FIG. 2), and the other (on the left side in FIG. 2). ) A nut 9X into which the connecting bolt 9 is screwed is fitted into the fitting hole 11d of the joint member 10. The fitting hole 11 d has a depth that prevents both the head 9 b and the nut 9 </ b> X of the connecting bolt 9 from protruding from the surface of the connecting part 11. For example, the fitting hole portion 11d has a hexagonal shape in accordance with the shape of the nut 9X.

  In addition, the cylindrical portion 12 of the joint member 10 has a shape in which a cylindrical corner portion is chamfered at the end on the connecting portion 11 side in the cylindrical axis direction, and the cylindrical portion 12 is gradually tapered. A tapered portion 12t for reducing the diameter is formed. On the other hand, a cylindrical diameter-reduced portion 12 d formed coaxially with the main body portion of the cylindrical portion 12 is provided on the side opposite to the connecting portion 11 side in the cylindrical axis direction of the cylindrical portion 12. That is, the annular step surface between the main body portion of the cylindrical portion 12 and the reduced diameter portion 12d becomes the mating surface 12a with respect to the end surface 6a of the pipe 6 as described above. Therefore, the cylindrical portion 12 is attached to the end portion of the pipe 6 in a state where the reduced diameter portion 12 d is inserted into the end portion of the pipe 6 and the mating surface 12 a is in contact with the end surface 6 a of the pipe 6. The outer diameter of the reduced diameter portion 12d is substantially the same as the inner diameter of the pipe 6.

  In the pipe connecting part 8 by such a joint member 10, when the joint members 10 are fixed by the connecting bolt 9 and the nut 9X, the position of the axial center of the connecting bolt 9 that penetrates the hemispherical connecting part 11 ( 4 (see FIG. 4, reference C1) can be rotated with respect to each other with the position of the rotation axis. For this reason, the connection angle of the joint members 10 is arbitrarily adjusted by the rotation of the connection bolt 9 about the axis. By adjusting the connection angle between the joint members 10, it is possible to arbitrarily correspond to a predetermined angle formed by the pipes 6 (6 a, 6 b) connected to each other at the corner portion 5 a of the handrail 5 as shown in FIG. 1. .

  According to the joint member 10 according to the present embodiment, as shown in FIG. 3, the pipes 6 are connected to each other from the state in which the 6s connected to each other are linear, that is, the angle between the pipes 6 is approximately 180 °. The connection angle between the joint members 10 is adjusted in a range up to a state where the angle between the two is approximately 90 ° (see the two-dot chain line). In other words, when one of the pipes 6 connected to each other and the joint member 10 attached to the pipe 6 are fixed, the other pipe 6 and the one pipe 6 are connected by the connection structure of the joint members 10. With a straight line as a reference position, the pipe 6 can be turned about 90 ° on both sides from the reference position within a total range of about 180 °. The connection angle between 10 is adjusted.

  In the joint member 10 according to the present embodiment, common parts are used regardless of which pipe 6 of the pipes 6 connected to each other is fixed to the end. That is, in the pipe connecting portion 8, the joint member 10 on the side where the connecting bolt 9 is inserted from the outside (the right side joint member 10 in FIG. 2) and the joint member 10 on the side where the nut 9X is fitted in the fitting hole portion 11d ( In FIG. 2, the left joint member 10) is a common member. According to such a structure, management of the components of the joint member 10 is facilitated, and the efficiency of the assembly work of the pipe connecting portion 8 can be improved.

  The joint structure 1 according to the present embodiment will be described with reference to FIGS. 7A is a view in the direction of arrow A in FIG. 5, and FIG. 7B is a view in the direction of arrow B in FIG. The joint structure 1 is used for attaching the joint member 10 to the end of the pipe 6. That is, the joint structure 1 according to the present embodiment plays a role of fixing the joint member 10 constituting the pipe connection portion 8 (see FIG. 4) to the end portion of the pipe 6 in the connection between the pipes 6.

  As shown in FIGS. 5 and 6, the joint structure 1 according to the present embodiment includes a cylindrical elastic body 20, a bolt member 30 and a nut member 40 that are members constituting a compression portion, and a joint member 10. . Each of these components is provided for each of the pipes 6 connected to each other.

  The cylindrical elastic body 20 has a cylindrical outer shape. In this embodiment, the cylindrical elastic body 20 has a cylindrical outer shape as a whole. Therefore, the cylindrical elastic body 20 has the outer peripheral surface 21 which makes a cylindrical surface, and the end surfaces 22 on both sides in the cylindrical axis direction (center axis direction). The cylindrical elastic body 20 has a bolt hole 23 for allowing the bolt member 30 to pass therethrough. The bolt hole 23 is formed in the central axis portion along the longitudinal direction (cylindrical axis direction) of the cylindrical elastic body 20 and opens to the end faces 22 on both sides.

  The cylindrical elastic body 20 is a member made of an elastic material. That is, the cylindrical elastic body 20 is an integral elastic part formed of a predetermined elastic material such as rubber. Examples of the elastic material constituting the cylindrical elastic body 20 include ethylene propylene rubber (Ethylene Propylene Diene rubber (EPDM), Ethylene Propylene rubber (EPM)), silicon rubber, urethane rubber, and the like. . However, these are merely examples, and the elastic material constituting the cylindrical elastic body 20 is not particularly limited.

  The cylindrical elastic body 20 is inserted into the end portion of the pipe 6. In the present embodiment, the cylindrical elastic body 20 has a circular cross section similar to the cross section of the pipe 6, and is inserted from the opening end of the pipe 6. The cylindrical elastic body 20 has an outer diameter that is substantially the same (slightly smaller) as the inner diameter of the pipe 6. That is, when the cylindrical elastic body 20 is inserted into the pipe 6, the cylindrical elastic body 20 is in contact with or substantially in contact with the inner peripheral surface 6 b of the pipe 6. Specifically, for example, the outer diameter dimension of the cylindrical elastic body 20 is such a dimension that there is a gap (clearance) of a few millimeters between the outer peripheral surface 21 and the inner peripheral surface 6b of the pipe 6. .

  The outer diameter size of the cylindrical elastic body 20 is smaller than the outer diameter size of the main body portion of the cylindrical portion 12 of the joint member 10 and is substantially the same as the outer diameter size of the reduced diameter portion 12 d of the cylindrical portion 12. In the present embodiment, the outer diameter dimension of the cylindrical portion 12 is substantially the same as the outer diameter dimension of the pipe 6, and the cylindrical elastic body 20 is located at one position concentric with the cylindrical portion 12 with respect to the joint member 10. The end surface 22 (22A) is fixed to the joint member 10 in a state where the end surface 22 (22A) is in contact with the end surface 12e of the reduced diameter portion 12d of the cylindrical portion 12. Further, as described above, the outer diameter of the cylindrical elastic body 20 is substantially the same as the inner diameter of the pipe 6. Therefore, the outer diameter of the cylindrical elastic body 20 is smaller than the outer diameter of the main body portion of the cylindrical portion 12 by the thickness of the peripheral wall of the pipe 6. In other words, in a state where the joint member 10 and the cylindrical elastic body 20 are fixed to each other, an annular mating surface having a width substantially the same as the thickness of the peripheral wall of the pipe 6 is provided on the periphery of the reduced diameter portion 12d of the cylindrical portion 12. 12a exists. A cylindrical elastic body 20 having substantially the same outer diameter and forming an integral cylindrical portion and a reduced diameter portion 12d of the cylindrical portion 12 are inserted into the pipe 6, and an end surface 6a of the pipe 6 is formed on the mating surface 12a of the cylindrical portion 12. Contact.

  According to the size relationship in the radial direction of the pipe 6, the joint member 10, and the cylindrical elastic body 20, the joint member 10 is fixed to the cylindrical elastic body 20 inserted into the pipe 6. And the outer peripheral surface 6c of the pipe 6 and the outer periphery of the cylindrical portion 12 of the joint member 10 in a state where the reduced diameter portion 12d of the cylindrical portion 12 is inserted into the pipe 6 and the mating surface 12a is in contact with the end surface 6a of the pipe 6. The surface 12c forms a continuous (coplanar) cylindrical surface. In the following description, among the end faces 22 on both sides of the cylindrical elastic body 20, the end face 22 on the side that contacts the end face 12e of the reduced diameter portion 12d of the cylindrical portion 12 of the joint member 10 (the right side in FIG. 5) is the outer end face 22A. The end surface 22 on the opposite side (left side in the figure) is defined as an inner end surface 22B.

  The joint member 10 and the cylindrical elastic body 20 are fixed to each other by a bolt member 30 and a nut member 40 that constitute a compression portion of the joint structure 1. In the present embodiment, the bolt member 30 is a bolt having a cross hole in the head 33. The bolt member 30 includes a shaft portion 31 having a screw portion 32 in which a male screw is cut in a predetermined range on one end side, and a head portion 33 provided on the opposite side of the shaft portion 31 to the screw portion 32 side.

  The bolt member 30 penetrates through the joint member 10, penetrates through the bolt hole 23 formed in the central shaft portion of the cylindrical elastic body 20, and the portion on the distal end side of the shaft portion 31 where the screw portion 32 is formed is cylindrical. It protrudes from the inner end surface 22B of the elastic body 20. The joint member 10 that penetrates the bolt member 30 has a shape portion as follows in detail.

  In the joint member 10, the connecting portion 11 is provided so as to protrude from the end surface of the cylindrical portion 12 opposite to the reduced diameter portion 12 d side. The connecting portion 11 is provided with respect to the cylindrical portion 12 such that the cylindrical axis (center axis) of the cylindrical portion 12 is positioned on a flat surface portion 11a corresponding to a split surface in a hemispherical shape (FIG. 7A). reference).

  On the other hand, the cylindrical portion 12 has a bolt hole 12b for allowing the bolt member 30 to pass therethrough. The bolt holes 12 b are formed in the central axis portion along the cylindrical axis direction of the cylindrical portion 12, open on both sides of the cylindrical portion 12 in the cylindrical axis direction, and are arranged in a concentric manner with the cylindrical portion 12. Are formed so as to be continuous with the bolt holes 23. A diameter-enlarged hole portion 12 f that receives the head portion 33 of the bolt member 30 is formed at an end portion of the bolt portion 12 b of the cylindrical portion 12 on the connecting portion 11 side. Moreover, in the cylindrical part 12, the recessed part 12g which is a part which forms the space which the diameter expansion hole part 12f of the bolt hole 12b opens, and receives a part of the connection part 11 of the other coupling member 10 is formed. .

  On the other hand, in the connecting part 11 that positions the flat part 11 a on the central axis of the cylindrical part 12, the concave groove 11 b for securing the insertion path of the bolt member 30 with respect to the bolt hole 12 b extends along the axial direction of the bolt member 30. Is formed on the flat portion 11a. As shown in FIG. 7A, the concave groove 11b has the flat surface portion 11a in the range where at least the head 33 of the bolt member 30 inserted into the bolt hole 12b overlaps when viewed from the central axis direction of the cylindrical portion 12. It has a groove shape along such a half cylinder surface. The bolt through hole 11c has the fitting hole portion 11d side opened at the top of the hemispherical surface of the connecting portion 11, and the opposite side to the fitting hole portion 11d side opened into the concave groove 11b.

  The bolt member 30 is inserted into the joint member 10 having the shape portion as described above from the connecting portion 11 side so as to penetrate the bolt hole 12b of the cylindrical portion 12 with the screw portion 32 side as the distal end side ( (See FIG. 8, arrow D1). The nut member 40 is screwed into a protruding portion of the bolt member 30 penetrating the joint member 10 and the cylindrical elastic body 20 from the inner end surface 22B of the cylindrical elastic body 20.

  The nut member 40 includes a pressing portion 41 that forms a pressing surface 42 against the cylindrical elastic body 20 and a nut portion 43 into which the screw portion 32 of the bolt member 30 is screwed. The pressing portion 41 is a disc-shaped portion, and one plate surface thereof is a pressing surface 42. A nut portion 43 is provided on the other plate surface side of the pressing portion 41 so as to protrude from the plate surface of the pressing portion 41.

  The nut portion 43 is a hexagonal nut-like portion in which a female screw portion 43a (see FIG. 8) into which the screw portion 32 of the bolt member 30 is screwed is formed, and the screwing direction of the bolt member 30 is the plate of the pressing portion 41. It is provided at a position that is perpendicular to the surface and concentric with the pressing portion 41. The bolt member 30 is screwed into the nut member 40 from the pressing surface 42 side. Accordingly, a hole 41a that is continuous with the female screw portion 43a of the nut portion 43 is formed in the central portion of the pressing portion 41 (see FIG. 8).

  Thus, the nut member 40 having the pressing portion 41 and the nut portion 43 has a substantially hat-like outer shape as a whole. The nut member 40 is configured, for example, by fixing a hexagonal nut constituting the nut portion 43 to a disk-like member constituting the pressing portion 41 by welding or the like. The nut member 40 having the above configuration sandwiches the cylindrical elastic body 20 between the joint member 10 in a state where the pressing surface 42 is in contact with the inner end surface 22B with respect to the cylindrical elastic body 20. The cylindrical elastic body 20 is pressed in the cylinder axis direction.

  As described above, the compression portion included in the joint structure 1 of the present embodiment includes the bolt member 30 that penetrates the cylindrical elastic body 20 in the cylindrical axis direction, and the protruding portion of the bolt member 30 from the cylindrical elastic body 20. And a nut member 40 to be mated. The compression section provided in the joint structure 1 compresses the cylindrical elastic body 20 in the cylinder axis direction, thereby elastically deforming the cylindrical elastic body 20 so that the cylindrical elastic body 20 expands in the direction of expanding the diameter. It is the composition.

  That is, the cylindrical elastic body 20 made of an elastic material such as EPDM is elastically deformed so that the outer peripheral surface 21 rises radially outward as a repulsive action accompanying the contraction of the elastic body by being compressed in the cylinder axis direction. The diameter is partially enlarged at least in the cylinder axis direction. Such elastic deformation of the cylindrical elastic body 20 is, for example, that the outer diameter gradually increases from both ends of the cylindrical elastic body 20 in the cylindrical axis direction to the central portion, so that the cylindrical elastic body 20 has a gentle spindle shape as a whole. This is a modification (see FIG. 9).

  In the present embodiment, a bolt member 30 that penetrates the cylindrical elastic body 20 and a nut member 40 that is screwed into the bolt elastic member 20 are employed as members that constitute the compression portion, and the cylindrical elastic body 20 is tightened by these members. Is compressed from the cylinder axis direction. That is, the compression unit according to the present embodiment causes the cylindrical elastic body 20 to move by the relative proximity movement between the nut member 40 and the head portion 33 of the bolt member 30 accompanying the relative rotation between the bolt member 30 and the nut member 40. Compress in the cylinder axis direction.

  The joint structure 1 having the above-described configuration is a cylindrical elastic body 20 that accompanies compression in the cylinder axis direction by a compression portion (bolt member 30 and nut member 40) of the cylindrical elastic body 20 inserted into the pipe 6. Due to the elastic deformation, the cylindrical elastic body 20 is brought into pressure contact with the inner peripheral surface 6 b of the pipe 6. A fixing action for connecting the pipes 6 to each other between the pipe 6 and the cylindrical elastic body 20 by the frictional resistance between the outer peripheral surface 21 of the cylindrical elastic body 20 and the inner peripheral surface 6b of the pipe 6. Get.

  In the present embodiment, the joint structure 1 uses a fixing action for connecting the pipes 6 to fix the joint member 10 to the pipe 6. That is, the joint structure 1 includes the joint member 10 attached to the end portion of the pipe 6 in addition to the cylindrical elastic body 20 and the compression portion (the bolt member 30 and the nut member 40). The joint member 10 is fixed to the end of the pipe 6 by a fixing action for connecting the pipes 6 obtained between the pipe 6 and the cylindrical elastic body 20 by the cylindrical elastic body 20 and the compression portion. Is done.

  The effect | action of the joint structure 1 of this embodiment is demonstrated using FIG. In FIG. 9, for the sake of convenience, the clearance between the outer peripheral surface 21 of the cylindrical elastic body 20 and the inner peripheral surface 6b of the pipe 6 and the elastic deformation of the cylindrical elastic body 20 are exaggerated.

  In fixing the joint member 10 to the pipe 6 by the joint structure 1 of the present embodiment, the nut member 40 is screwed into the bolt member 30 penetrating the joint member 10 and the cylindrical elastic body 20, so that the joint member 10, the cylinder The elastic member 20, the bolt member 30, and the nut member 40 are supported and integrated with each other between the members. An integral configuration including the joint member 10 (hereinafter referred to as “joint unit”) is inserted into the pipe 6 from the open end of the pipe 6 with the nut member 40 side as a tip side. In a state where the joint unit is inserted into the pipe 6, the nut member 40, the cylindrical elastic body 20, and the reduced diameter portion 12 d of the cylindrical portion 12 are located in the pipe 6, and the end surface 6 a of the pipe 6 is the joint member 10. It contacts the mating surface 12a of the cylindrical portion 12.

  As shown in FIG. 9, the bolt member 30 that is screwed into the nut member 40 is tightened in a state where the joint unit is inserted into the pipe 6. The rotation operation of the bolt member 30 for screwing the bolt member 30 into the nut member 40, that is, the tightening operation of the bolt member 30, is performed using a tool such as a screwdriver. Here, the cylindrical elastic body 20 is in a state in which the outer peripheral surface 21 is in contact with the inner peripheral surface 6b of the pipe 6 and the outer end surface 22A is in contact with the end surface 12e of the reduced diameter portion 12d of the cylindrical portion 12, Due to the frictional force at these surface contact portions, the joint rotation of the cylindrical elastic body 20 with the rotation of the bolt member 30 is restricted. In addition, the nut member 40 is subjected to co-rotation regulation accompanying the rotation of the bolt member 30 due to the frictional force at the contact portion of the pressing surface 42 with the inner end surface 22B of the cylindrical elastic body 20. Here, for example, by providing an uneven portion on the pressing surface 42 of the nut member 40, it is possible to effectively restrict the rotation of the nut member 40 accompanying the rotation of the bolt member 30.

  Thus, according to the joint structure 1 of the present embodiment, the cylindrical elastic body 20 is moved in the cylinder axial direction only by the tightening operation of the bolt member 30 that is the operation from the opening end side of the pipe 6, that is, the joint member 10 side. The action for compressing to the above is obtained. However, if necessary, an operation for fixing the cylindrical elastic body 20 and the nut member 40 may be performed in the rotation operation of the bolt member 30.

  The bolt member 30 is tightened, that is, by the relative rotation of the bolt member 30 and the nut member 40 in the direction in which the bolt member 30 is screwed into the nut member 40, the screw portion 32 and the female screw portion 43a that are screwed together. The nut member 40 moves to the joint member 10 side, that is, the head 33 side of the bolt member 30 (see arrow E1). Here, the bolt member 30 penetrating the joint member 10 is configured to restrict the relative movement in the axial direction with respect to the joint member 10 by fitting the head portion 33 into the enlarged diameter hole portion 12f of the bolt hole 12b of the cylindrical portion 12. receive. For this reason, the proximity movement of the nut member 40 with respect to the head 33 by the turning operation of the bolt member 30 is the proximity movement of the nut member 40 with respect to the joint member 10.

  Therefore, the cylindrical elastic body 20 in a state where the outer end surface 22A is in contact with the end surface 12e of the cylindrical portion 12 and the inner end surface 22B is in contact with the pressing surface 42 of the nut member 40 is rotated in the tightening direction of the bolt member 30. Thus, the joint member 10 and the nut member 40 are compressed in the cylinder axis direction (see arrow F1). Relatively, the cylindrical elastic body 20 in a state where the outer end face 22A is in contact with the end face 12e of the cylindrical portion 12 is a nut member that approaches the head 33 side, that is, the joint member 10 side by the turning operation of the bolt member 30. By being pressed by the pressing portion 41 of 40, it is compressed in the cylinder axis direction. Thus, the bolt member 30 and the nut member 40 act on the cylindrical elastic body 20 via the joint member 10 to apply a compressive force that compresses the cylindrical elastic body 20 in the cylinder axis direction.

  By such compression of the cylindrical elastic body 20 in the cylinder axis direction, the cylindrical elastic body 20 contracts in the cylinder axis direction. The cylindrical elastic body 20 swells in the radial direction around the central portion in the cylindrical axis direction so as to form a gentle spindle shape as a whole as a repulsive action accompanying the contraction in the cylindrical axis direction (so as to expand in diameter). To) elastically deform (see arrow F2).

  Due to such elastic deformation, the cylindrical elastic body 20 is in a state in which the outer peripheral surface 21 is pressed against the inner peripheral surface 6b of the pipe 6 in the entire circumferential direction. Due to the frictional resistance (friction force) between the outer peripheral surface 21 of the cylindrical elastic body 20 and the inner peripheral surface 6b of the pipe 6 obtained in such a state (see the portion indicated by reference numeral G1), the pipe 6 and the joint member 10 and the relative movement in the axial direction (in the cylindrical axis direction of the cylindrical elastic body 20) and the relative rotation around the axis (in the circumferential direction) are restricted. That is, the joint member 10 is fixed to the pipe 6. Here, since the cylindrical elastic body 20 is sandwiched between the end surface 12e of the cylindrical portion 12 and the pressing surface 42 of the nut member 40 and compressed in the cylinder axial direction, the outer end surface 22A is in pressure contact with the end surface 12e. It becomes. The frictional resistance between the outer end face 22 </ b> A and the end face 12 e in such a state contributes to regulation of relative rotation around the axis between the pipe 6 and the joint member 10.

  As described above, the joint structure 1 of the present embodiment has the friction resistance between the pipe 6 and the cylindrical elastic body 20 and the friction resistance between the joint member 10 and the cylindrical elastic body 20 with respect to the joint member 10. Is used as a force for fixing to the pipe 6.

  As described above, the joint structure 1 that obtains a frictional force as a fixing force for fixing the joint member 10 to the pipe 6 by compressing the cylindrical elastic body 20 in the cylindrical axis direction is preferably a cylindrical elastic body. 20 has a chamfered portion 25 at a corner portion at the end thereof. In the present embodiment, the cylindrical elastic body 20 has a chamfered portion 25 at the corner portion of the end portion on the inner end surface 22B side that contacts the nut member 40. That is, the cylindrical elastic body 20 has the chamfered portion 25 at the corner portion formed by the outer peripheral surface 21 and the inner end surface 22B that is one end surface in the cylinder axis direction.

  The chamfered portion 25 has a tapered surface 25a that gradually reduces the diameter of the end portion of the cylindrical elastic body 20 in the cylinder axis direction toward the inner end surface 22B side (left side in FIG. 5) with respect to the portion forming the outer peripheral surface 21. This is the part to be formed. The tapered surface 25a is formed at an inclination angle of 45 ° with respect to the central axis of the cylindrical elastic body 20 in a longitudinal sectional view passing through the central axis of the cylindrical elastic body 20, for example. However, the inclination angle of the tapered surface 25a is not particularly limited.

  The disc-shaped pressing portion 41 constituting the nut member 40 is a portion where the chamfered portion 25 forms the outer peripheral surface 21 with respect to the end of the cylindrical elastic body 20 in which the chamfered portion 25 is thus formed. The inner end face 22B is reduced in diameter with respect to the inner end face 22B. That is, the pressing portion 41 has an outer diameter that is slightly smaller than the outer diameter of the portion forming the outer peripheral surface 21 in the cylindrical elastic body 20 by the reduced diameter due to the tapered surface 25a.

  By forming the chamfered portion 25 in the cylindrical elastic body 20 in this way, the inner end face that receives the pressing force (compression force) in the cylinder axis direction by the bolt member 30 and the nut member 40 in the cylindrical elastic body 20. 22B will approach the center side (center axis side) with respect to the part which forms the outer peripheral surface 21 of the cylindrical elastic body 20. FIG. For this reason, it becomes possible to transmit efficiently the compressive force of the cylinder axial direction which acts on the cylindrical elastic body 20 as stress for producing the elastic deformation which the cylindrical elastic body 20 swells to radial direction. . Thereby, the cylindrical elastic body 20 can be efficiently elastically deformed by the tightening operation of the bolt member 30, and the friction between the pipe 6 and the cylindrical elastic body 20 caused by the elastic deformation of the cylindrical elastic body 20. Power can be obtained efficiently. Therefore, workability can be improved for the work for fixing the joint member 10 to the pipe 6 by the frictional force between the pipe 6 and the cylindrical elastic body 20.

  In the present embodiment, the chamfered portion 25 is formed only at the corner portion of the cylindrical elastic body 20 on the inner end surface 22B side. However, the chamfered portion 25 is not limited to this, and the chamfered portion 25 is on the outer end surface 22A side. May be formed only at the corner portions of the inner end face 22B, or may be formed at both corner portions on the inner end face 22B side and the outer end face 22A side. In other words, the configuration in which the cylindrical elastic body 20 has the chamfered portion 25 is a surface at least at one corner portion of the corner portions formed by the outer peripheral surface 21 of the cylindrical elastic body 20 and the end surfaces 22 on both sides in the cylinder axis direction. The taking part 25 should just be provided.

  The usage method of the joint structure 1 which concerns on this embodiment provided with the above structures is demonstrated using FIG. 10, the clearance between the outer peripheral surface 21 of the cylindrical elastic body 20 and the inner peripheral surface 6b of the pipe 6 and the elastic deformation of the cylindrical elastic body 20 are exaggerated similarly to FIG. Yes.

  As shown in FIG. 10A, first, the bolt member 30 is passed through the joint member 10 and the cylindrical elastic body 20, and the nut member 40 is screwed into the protruding portion of the bolt member 30 from the cylindrical elastic body 20. Thus, the joint unit is configured. The joint unit is inserted into the pipe 6 from the opening end of the pipe 6 with the nut member 40 side as the front end side.

  As shown in FIG. 10B, the joint unit is inserted until the end surface 6 a of the pipe 6 contacts the mating surface 12 a of the cylindrical portion 12 constituting the joint member 10. After the joint unit is inserted into the pipe 6, the bolt member 30 is tightened.

  As shown in FIG. 10C, by performing the tightening operation of the bolt member 30, the nut member 40 screwed to the bolt member 30 moves so as to approach the joint member 10 side. By the relative proximity movement of the nut member 40 relative to the joint member 10, the cylindrical elastic body 20 sandwiched between the joint member 10 and the nut member 40 is compressed in the cylinder axis direction. Thereby, the cylindrical elastic body 20 is elastically deformed so as to expand its diameter around the central portion in the cylinder axis direction, and the outer peripheral surface 21 is brought into pressure contact with the inner peripheral surface 6b of the pipe 6. The joint member 10 is fixed to the pipe 6 by the frictional resistance (frictional force) with the inner peripheral surface 6b.

  The fixing of the joint member 10 using the cylindrical elastic body 20 to the pipe 6 is performed in the same manner for the mating pipe 6 and the joint member 10 to be connected. Then, the joint members 10 fixed to each of the pipes 6 that are connected to each other are angled to each other in accordance with the angle formed by the pipes 6 by the connecting bolt 9 (see FIG. 2) constituting the pipe connecting portion 8. Is adjusted and connected and fixed. In this manner, the pipes 6 are connected to each other at a predetermined angle via the pair of joint members 10.

  According to the joint structure 1 which concerns on this embodiment as mentioned above, the following pipe connection methods are realizable. That is, the pipe connection method according to the present embodiment is a pipe connection method used for connecting the pipes 6 to each other, and has a cylindrical outer shape, is made of an elastic material, and is inserted into the pipe 6. An elastic body 20 is used. Then, by compressing the cylindrical elastic body 20 inserted in the pipe 6 in the direction of the cylinder axis, the cylindrical elastic body 20 is elastically deformed so as to expand in the direction of expanding the diameter. By this elastic deformation, the cylindrical elastic body 20 is brought into pressure contact with the inner peripheral surface 6b of the pipe 6, and the frictional resistance between the outer peripheral surface 21 of the cylindrical elastic body 20 and the inner peripheral surface 6b of the pipe 6 A fixing action for connecting the pipes 6 to each other with the cylindrical elastic body 20 is obtained.

  In the pipe connection method according to the present embodiment, the bolt member 30 is passed through the cylindrical elastic body 20 along the cylinder axis direction, and the nut member 40 is screwed into the protruding portion of the bolt member 30 from the cylindrical elastic body 20. The cylindrical elastic body 20 is compressed in the cylinder axial direction by relatively rotating the bolt member 30 and the nut member 40 so that the nut member 40 and the head of the bolt member 30 are relatively close to each other. .

  According to the joint structure 1 and the pipe connection method of the present embodiment described above, safety can be easily ensured and construction labor can be simplified as described below.

  For example, when a conventional joint structure as shown in FIG. 12 is adopted in the handrail, the head of the bolt 121 screwed into the cylindrical portion 112 of the joint member 110 from the outside of the pipe 106 is against the surface of the pipe 106. Thus, there is a concern about contact of the hand with the protruding portion, which is not preferable in terms of safety. In this regard, according to the joint structure 1 and the pipe connection method of the present embodiment, the cylindrical elastic body 20, the bolt member 30, and the nut member 40, which are configurations for fixing the joint member 10 to the pipe 6, Or since it is the structure located in the inside of the coupling member 10, a protrusion part does not protrude outside the pipe 6. FIG. For this reason, in the handrail 5 as shown in FIG. 1, it is possible to avoid danger and discomfort due to the presence of the protruding portion on the surface of the pipe 6, and to easily ensure safety and a comfortable feeling of use. it can.

  Further, according to the conventional joint structure as shown in FIG. 12, at the construction site where the pipe 106 is disposed, according to the disposition direction of the pipe 106 that defines the angle formed between the pipes 106 connected to each other, After adjusting the position of the relative rotation direction of the pipe 106 and the joint member 110 inserted therein (rotation direction around the axis of the pipe 106), holes for screwing the bolts 121 are formed in the pipe 106 and the joint member. A hole forming process for forming the hole 110 is performed. According to such a construction procedure, it is necessary to perform drilling processing for each connecting portion of the pipes 106 in accordance with the state of arrangement of the pipes 106 at the construction site, which makes the work complicated and laborious. It will be. In this regard, according to the joint structure 1 and the pipe connection method of the present embodiment, when the joint unit including the joint member 10 is inserted into the pipe 6, the pipe 6 and the joint member 10 are relatively rotated by rotating the joint unit. The pipe 6 and the joint member 10 can be fixed to each other in a desired positional relationship with respect to the rotational direction simply by adjusting the position in the general rotational direction and performing the tightening operation of the bolt member 30. For this reason, since the labor of the drilling process in the conventional joint structure as described above can be saved, the fixing operation of the joint member 10 to the pipe 6 can be easily performed, and good workability can be obtained. . As a result, it is possible to easily face the arrangement situation of the pipe 6 at the construction site.

  Further, according to the conventional joint structure as shown in FIG. 12, the bolt 121 for fixing the joint member 110 to the pipe 106 may be loose due to poor tightening. Such looseness due to poor tightening of bolts is not preferable in terms of safety in handrails and the like. In this regard, according to the joint structure 1 and the pipe connection method of the present embodiment, sufficient frictional resistance is generated between the cylindrical elastic body 20 and the pipe 6, that is, the joint member 10 is fixed to the pipe 106. As a result, it can be confirmed that the bolt member 30 is securely tightened, so that it is possible to avoid a poor tightening of the bolt member 30 for fixing the joint member 10 to the pipe 6.

  Furthermore, the exposure of the heads of the bolts 121 on the surface of the pipe 106 as in the conventional joint structure as shown in FIG. 12 may cause the appearance design to deteriorate. In this regard, according to the joint structure 1 and the pipe connection method of the present embodiment, the structure for fixing the joint member 10 to the pipe 6 is located inside the pipe 6 or the joint member 10 as described above. No bolts or the like are exposed on the surface of 6. For this reason, appearance design nature can be improved.

  Moreover, the following can be said about appearance design property. That is, in the joint structure 1 of this embodiment, as described above, the outer peripheral surface 6c of the pipe 6 and the outer peripheral surface 12c of the cylindrical portion 12 of the joint member 10 form a cylindrical surface that is continuous with each other. According to such a configuration, the joint portion between the pipe 6 and the joint member 10 can be made inconspicuous, a sense of unity between the pipe 6 and the joint member 10 is produced, the appearance is clean, and the appearance design is improved. Figured.

  In the joint structure 1 and the pipe connection method of the present embodiment described above, the bolt member 30 and the nut member 40 are employed as the compression portion that compresses and elastically deforms the cylindrical elastic body 20. However, it is not limited to this. In other words, the compression unit may be configured to elastically deform the cylindrical elastic body 20 so that the cylindrical elastic body 20 expands in the direction of expanding the diameter by compressing the cylindrical elastic body 20 in the cylinder axis direction. For example, various modifications can be applied.

  As the compression unit, for example, a structure that generates a pressing force for compressing the cylindrical elastic body 20 by using an elastic force by an elastic body such as a spring or a cylinder mechanism, an engagement action between members, and a fitting operation. The structure etc. which press the cylindrical elastic body 20 in a cylinder axial direction and compress it by using can be considered. However, the following advantages can be obtained by adopting the bolt member 30 and the nut member 40 as members constituting the compression portion as in the joint structure 1 and the pipe connecting method of the present embodiment. That is, a desired pressing force can be applied to the cylindrical elastic body 20 with a simple configuration. In addition, since the bolt member 30 can be tightened from one side (open end side) of the pipe 6, good workability can be obtained when the cylindrical elastic body 20 is compressed. Further, since the cylindrical elastic body 20 can be easily attached and removed by operating the bolt member 30, the assembly work of the cylindrical elastic body 20 and the maintenance work for the cylindrical elastic body 20 can be easily performed. Can do. There may be a plurality of combinations of the bolt member 30 and the nut member 40, but from the viewpoint of tightening workability of the bolt member 30, balance of elastic deformation of the cylindrical elastic body 20, and the like, the cylinder as in the present embodiment. It is preferable that one bolt member 30 and one nut member 40 (one set of bolt member 30 and nut member 40) located at the central axis portion of the elastic body 20 are used. In the present embodiment, the bolt member 30 is a bolt having a cross hole in the head 33, but is not limited thereto. As bolt member 30, other bolt members, such as a hexagon socket head bolt which has a cylindrical head in which a hexagon hole was formed, and a countersunk bolt with a hexagon socket, are adopted suitably, for example.

  Moreover, the joint structure 1 of this embodiment is provided with the joint member 10 interposed between the ends of the mating pipe 6 to be coupled, and as a fixing action obtained between the cylindrical elastic body 20 and the pipe 6. Although the joint member 10 is fixed to the pipe 6 by the frictional resistance, the joint structure 1 can also be applied when the pipes 6 are directly connected to each other without the joint member 10 interposed therebetween. An application example in this case will be described with reference to FIG. For convenience, the same reference numerals are used as appropriate for the configurations already described.

  As shown in FIG. 11, in this application example, in the state where pipes 6 of the same diameter that are connected to each other face each other, the cylindrical elastic body 20 and the bolt member are connected to the joint portion between the pipes 6. The structure including 30 and the nut member 40 is inserted. Here, the cylindrical elastic body 20 is disposed so that the position of the joint surface between the pipes 6 is positioned in the intermediate portion in the cylinder axis direction. Further, in this application example, a disk support plate for supporting the head 33 against the outer end surface 22 </ b> A of the cylindrical elastic body 20 between the head 33 of the bolt member 30 and the cylindrical elastic body 20. 51 is interposed.

  In such a configuration, when the bolt member 30 is tightened, the cylindrical elastic body 20 sandwiched between the joint member 10 and the nut member 40 is compressed in the cylinder axis direction. Thereby, the cylindrical elastic body 20 is elastically deformed so as to expand its diameter around the central portion in the cylinder axis direction, and the inner peripheral surface 6b at the end portion on the opening side of the pipes 6 connected to each other. The pipes 6 are directly fixed to each other by the frictional resistance (friction force) between the outer peripheral surface 21 and the inner peripheral surface 6b.

  As in this application example, the joint structure 1 of the present embodiment can also be applied to a case where the pipes 6 are directly connected (joined) without using the joint member 10. That is, in this application example, the joint structure 1 directly performs the frictional resistance obtained by elastically deforming the cylindrical elastic body 20 by the compression portion, that is, the fixing action for connecting the pipes 6 to each other. It is used to connect to.

  Further, regarding the cylindrical elastic body 20 provided in the joint structure 1, the length in the cylinder axis direction is such that the pipes 6 are in contact with each other by pressing the outer peripheral surface 21 against the inner peripheral surface 6 b of the pipe 6 with the elastic deformation of the cylindrical elastic body 20. The frictional resistance is set as appropriate so that a sufficient frictional resistance can be obtained as a fixing action for connecting the two. Further, as the material of the cylindrical elastic body 20, in consideration of heat resistance, cold resistance, weather resistance, etc., EPDM, silicon rubber, urethane rubber and the like as described above are appropriately employed.

  Further, regarding the cylindrical elastic body 20, in the present embodiment, the cylindrical elastic body 20 having a cylindrical outer shape having a circular cross-sectional shape in accordance with the cross-sectional shape of the pipe 6 is employed, but the present invention is not limited thereto. Not. The cylindrical elastic body 20 has a wide cylindrical shape depending on the cross-sectional shape of the pipe 6 or regardless of the cross-sectional shape of the pipe 6, for example, an elliptical or polygonal cross-sectional shape. Any device having an outer shape may be used. Therefore, also about the pipe 6 connected using the joint structure 1, the cross-sectional shape is not restricted circularly, It may have an elliptical or polygonal cross-sectional shape.

  The joint structure according to the present invention can be widely applied in indirect connection between pipes via a predetermined joint member and direct connection between pipes. Therefore, the joint structure according to the present invention is not limited to the case where the joint structure is used for connecting a pair of pipes. For example, a pipe as a support column supporting the connecting portion is provided for the connecting portion of the pipes constituting the handrail. As in the configuration described above, the present invention can also be applied to a configuration in which three pipes are connected to each other at a predetermined connecting portion so as to form a substantially T shape.

1 Joint structure (joint structure for pipe connection)
6 Pipe 6b Inner peripheral surface 10 Joint member 20 Cylindrical elastic body 21 Outer peripheral surface 25 Chamfered portion 30 Bolt member 33 Head 40 Nut member 42 Pressing surface 43 Nut portion

Claims (6)

A joint structure for connecting pipes used for connecting pipes,
A cylindrical elastic body having a cylindrical outer shape, made of an elastic material, and inserted into the pipe;
A compression unit that elastically deforms the cylindrical elastic body so that the cylindrical elastic body expands in a direction in which the cylindrical elastic body expands by compressing the cylindrical elastic body in a cylindrical axis direction of the cylindrical elastic body; Prepared,
The cylindrical elastic body is pressed against the inner peripheral surface of the pipe by the elastic deformation of the cylindrical elastic body accompanying the compression of the cylindrical elastic body in the cylinder axial direction by the compression portion of the cylindrical elastic body in a state of being inserted into the pipe. The fixing action for connecting the pipes between the pipe and the cylindrical elastic body is obtained by the frictional resistance between the outer peripheral surface of the cylindrical elastic body and the inner peripheral surface.
Pipe connection joint structure. The compression unit is
A bolt member penetrating the cylindrical elastic body in the cylindrical axis direction;
A nut member screwed into a protruding portion of the bolt member from the cylindrical elastic body,
Compressing the cylindrical elastic body in the cylindrical axis direction by relative proximity movement of the nut member and the head of the bolt member with relative rotation of the bolt member and the nut member;
The joint structure for pipe connection according to claim 1. It further includes a joint member that is attached to and connected to the end of the pipe to be connected to the end of the pipe,
The joint member is fixed to an end of the pipe by the fixing action.
The joint structure for pipe connection according to claim 1 or 2. The cylindrical elastic body has a chamfered portion in at least one corner portion among corner portions formed by the outer peripheral surface and end surfaces on both sides in the cylindrical axis direction.
The joint structure for pipe connection according to any one of claims 1 to 3. A pipe connection method used for connecting pipes,
It has a cylindrical outer shape, is made of an elastic material, and uses a cylindrical elastic body inserted into the pipe,
By compressing the cylindrical elastic body inserted into the pipe in the cylindrical axis direction of the cylindrical elastic body, the cylindrical elastic body is expanded so as to expand in the direction in which the cylindrical elastic body expands in diameter. By elastically deforming, the cylindrical elastic body is pressed against the inner peripheral surface of the pipe by elastic deformation of the cylindrical elastic body, and by the frictional resistance between the outer peripheral surface of the cylindrical elastic body and the inner peripheral surface, Between the pipe and the cylindrical elastic body, a fixing action for connecting the pipes is obtained.
Pipe connection method. Let the bolt elastic member penetrate the bolt member along the cylinder axis direction,
A nut member is screwed into a protruding portion of the bolt member from the cylindrical elastic body,
By relatively rotating the bolt member and the nut member, the nut elastic member and the head of the bolt member are brought relatively close to each other, thereby compressing the cylindrical elastic body in the cylindrical axis direction.
The pipe connection method according to claim 5.

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