JP5836165B2 - Branch joint - Google Patents

Description

  The present invention relates to a branch joint.

  In recent years, as shown in FIG. 9, embedment of cables 1 such as power cables and communication cables in the underground 2 has been promoted.

  In this way, by burying the cables 1 in the ground 2, it becomes possible to eliminate electric wires, utility poles, etc. from the ground, making the walking space barrier-free, maintaining a good living environment, and history It becomes possible to aim at the preservation of the townscape.

  The cables 1 described above are buried in the ground 2 in a state of being accommodated in the cable protection tube 3.

  Such a cable protection tube 3 is required to be divergent so that the number of connection destinations can be increased later. A branch joint 4 is used to branch the cable protection tube 3 (see, for example, Patent Document 1).

  As shown in FIG. 10, the conventional branch joint 4 is provided with a partially cylindrical mounting surface portion 5 that can come into contact with the side surface of the cable protection tube 3, and projecting obliquely outward from the mounting surface portion 5. A branch pipe portion 6 is projected on the inner surface of the attachment surface portion 5 so as to surround the edge of the attachment surface side opening 7 formed on the attachment surface portion 5 side of the branch tube portion 6, and is attached to the cable protection tube 3. It has an inward protruding edge portion 9 that can be inserted into the opening 8 for branching formed.

  The inward protruding edge 9 has a protruding height that is substantially the same as or higher than the wall thickness of the cable protection tube 3, thereby protecting the cables 1 from the edge of the branch opening 8. It is supposed to get.

  The inner projecting edge 9 has a closed loop shape that surrounds the edge of the mounting surface side opening 7 over the entire circumference, thereby opening the branch of the cable protection tube 3. There is one that improves the positioning with respect to the portion 8.

JP 2012-41954 A

  However, the above-described branch joint has the following problems.

  That is, the branch joint 4 is provided on the inner surface of the mounting surface portion 5 so that the inner projecting edge portion 9 of the closed loop shape surrounds the edge portion of the mounting surface side opening portion 7, so that the rigidity is considerably high. Therefore, when attaching the attachment surface portion 5 to the outer surface of the cable protection tube 3, it is difficult to make the attachment surface portion 5 closely contact the cable protection tube 3.

  More specifically, there is a manufacturing error in the cable protection tube 3 and the branch joint 4, and in addition, the cable protection tube 3 described above is formed at the time of extrusion molding when the branch opening 8 is cut off at the work site. The residual stress acts, so that the peripheral portion of the branch opening 8 is deformed toward the tube center direction and tends to be partially reduced in diameter.

  However, since the branch joint 4 is manufactured in a uniform shape in the axial direction according to the shape of the cable protection tube 3 before the opening 8 for branching is cut, the rigidity of the branch joint 4 is as described above. If it is excessively high, a large gap (ski) is generated between the peripheral portion of the branch opening 8 partially reduced in diameter as described above, which may cause adhesion failure or a band. Even if it is secured with a member, it may cause the cable protection tube 3 not to be in close contact.

  For this reason, in Patent Document 1 described above, the shape or the radius of curvature of each part in the axial direction of the mounting surface portion 5 of the branch joint 4 is delicately adjusted so as to match the diameter of the cable protection tube 3 after the branching opening 8 is cut. However, in this case, the manufacturing and processing becomes difficult and costly, and the diameter reduction situation of the cable protection tube 3 due to the opening of the branch opening 8 depends on the individual case. Because of the difference, there arises a problem that it is difficult to match the shape to suit each case.

  In addition, since the inward protruding edge portion 9 provided on the mounting surface portion 5 is relatively thick, the heat dissipation is not so good, so that it is difficult to form and it is difficult to improve productivity. There was a problem.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a partially cylindrical mounting surface portion capable of coming into contact with the outer surface of the cable protection tube, and projecting obliquely outward from the mounting surface portion. Into the opening for branching formed in the cable protection pipe projecting from the inner surface of the mounting surface portion so as to surround the entire circumference of the branch pipe portion and the edge of the opening on the mounting surface side of the branch pipe portion In the branch joint having an inward projecting edge portion that can be inserted and disposed, the inward projecting edge portion has a cutout portion that communicates between the inner and outer sides of the inward projecting edge portion at at least one position in the circumferential direction. It is characterized by that.

Further, the cutout portion is provided at a portion on the acute angle side where the attachment surface portion and the branch pipe portion branch at an acute angle in the inwardly protruding edge portion.

  According to invention of Claim 1, the following effects can be acquired by the said structure. That is, since the inward protruding edge portion has a notch portion that communicates between the inside and outside of the inward protruding edge portion at at least one position in the circumferential direction, the mounting surface portion can be easily elastically deformed. The adhesion of the mounting surface portion to the outer surface of the cable protection tube can be enhanced. In addition, since the surface area of the inwardly protruding edge portion is increased by the notch portion, the heat dissipation when forming the branch joint is improved, so that the molding time can be shortened and the productivity can be improved.

In addition , since the notch portion is provided at the acute angle side portion where the mounting surface portion and the branch pipe portion branch at an acute angle at the inwardly protruding edge portion, the mounting surface portion becomes relatively rigid and elastically deforms. Since the notch is provided in the vicinity of the part where it is difficult to form the gap between the cable protection tube and the cable protection tube, the adhesion of the mounting surface part to the outer surface of the cable protection tube is improved. Can be effectively increased. In addition, since the above-mentioned acute angle portion is a place where the cables are difficult to be contacted when the cables are passed through the branch pipe portion, it is possible to prevent the cables from being damaged even if the cutout portion is provided. .

It is a side view of the branch joint concerning the Example of this invention. It is a top view of FIG. It is a front view of FIG. It is a bottom view of FIG. FIG. 5 is a perspective view of FIG. 4. It is a longitudinal cross-sectional view of FIG. FIG. 7 is a partially enlarged view of the acute angle side of the cross-sectional view of FIG. 6. It is a bottom view similar to FIG. 4 showing a modification. It is a figure which shows the state which embeds cables in the ground. It is sectional drawing which looked at the conventional branch joint from the side.

  Hereinafter, examples embodying the present embodiment will be described in detail with reference to the drawings.

  <Configuration> The configuration will be described below.

    1 to 8 show this embodiment and its modifications.

  In recent years, it has been promoted to embed cables such as power cables and communication cables in the ground.

  In this way, by burying cables in the ground, it becomes possible to eliminate electric wires and utility poles from the ground, making the walking space barrier-free, creating a good living environment, and historical streets It becomes possible to aim at the maintenance of.

  And the above-mentioned cables will be embed | buried in the ground in the state accommodated in the inside of a cable protection pipe (refer FIG. 9, FIG. 10).

  Such a cable protection tube is required to be divergent so that the number of connection destinations can be increased later. A branch joint 21 as shown in FIGS. 1 to 7 is used for branching the cable protection tube.

  The branch joint 21 includes a partially cylindrical mounting surface portion 22 that can be in contact with the outer surface of the cable protection tube, a branch pipe portion 23 that projects obliquely outward from the mounting surface portion 22, and the branch A branching opening formed on the inner surface of the mounting surface portion 22 so as to surround the entire edge of the mounting surface side opening 24, which is an opening on the mounting surface portion 22 side of the tube portion 23, and is formed in the cable protection tube. It has an inward projecting edge 25 (see FIG. 4 and the like) that can be inserted and arranged in the part.

  The inward protruding edge 25 has a protruding height that is substantially the same as or slightly higher than the wall thickness of the cable protection tube, so that the cables can be protected from the edge of the branch opening. And so on Further, it is used for guiding the cables when the cables are drawn into the cable protection tube.

  In this case, the aforementioned branch joint 21 is made of a hard resin such as vinyl chloride. The above-described “mounting surface portion 22” has an inner diameter substantially equal to the outer diameter of the cable protection tube and has a substantially uniform thickness.

  A branch pipe of a cable protection pipe is connected to the above-mentioned “branch pipe part 23” at the opening on the tip side. The branching angle between the attachment surface portion 22 and the branch pipe portion 23 is an angle at which the cables are easily drawn. More specifically, the angle is 25 ° to 50 °. Further, the obtuse angle side 33 of the branch pipe portion 23 is curved with a radius of curvature that is the same as or slightly larger than the allowable radius of curvature of the cables.

  And the branch pipe part 23 is made into the thing of the substantially uniform thickness etc. of the thickness substantially equal to the attachment surface part 22. FIG. However, as shown in FIG. 7, the branch portion on the acute angle side 32 of the mounting surface portion 22 and the branch pipe portion 23 is thicker than the other portions in order to make the structure strong against external force and stress concentration. It is said that. Moreover, as shown in FIG. 6, the attachment surface part 22 and the branch pipe part 23 are continued so that it may be in a smooth flush state on both the inner and outer surfaces. The attachment surface portion 22 and the branch pipe portion 23 are integrally formed by injection molding or the like.

  As shown in FIG. 4, the above-described “mounting surface side opening 24” has a substantially oval shape that extends in the axial direction of the cable protection tube as viewed from the inner surface side of the mounting surface portion 22.

  The above-mentioned “inwardly projecting edge portion 25” is provided along the oval mounting surface side opening 24, and thus has a flat surface having arcuate portions 25a and 25b and linear portions 25c and 25d. It is assumed that the shape is almost elliptical. However, the planar shape of the inward protruding edge 25 is not limited to this.

  In this case, as shown in FIG. 6, the inwardly projecting edge portion 25 can be easily or easily removed from the outer peripheral surface of the arc-shaped portion 25a and the inner peripheral surface of the arc-shaped portion 25b. In each case, inclined surfaces having substantially the same or smaller angle than the branching direction of the branch pipe portion 23 are formed.

  Further, on the inner peripheral surface of the arc-shaped portion 25a and the outer peripheral surface of the arc-shaped portion 25b, there are formed standing surfaces that extend in the vertical direction of FIG. Further, the arc-shaped portion 25a has a narrow width having a substantially triangular cross-sectional shape, and the arc-shaped portion 25b has a narrow and substantially trapezoidal cross-section close to the triangular cross-section. It is supposed to be of width.

  The above-described branch joint 21 is usually fixed to the cable protective tube by adhesion and a band member (not shown) (that is, both adhesion fixation and band fixation are performed).

  In order to fix the band, as shown in FIG. 1 or FIG. 2, a band groove 34 extending in the circumferential direction is formed on the outer surface of at least one end portion of the mounting surface portion 22 in the axial direction. The band groove 34 is formed to have a width dimension and a depth dimension that are the same as or slightly larger than those according to the width dimension and thickness dimension of a band member (not shown). In addition to the above, the band groove 34 is provided in the vicinity of both ends in the axial direction of the mounting surface portion 22 as shown in FIG. Can be provided.

  In addition to the basic configuration as described above, the present embodiment has the following configuration.

(Configuration 1)
As shown in FIG. 4 and the like, the above-mentioned inwardly projecting edge 25 communicates between the inside and outside of the inwardly projecting edge 25 (or between the inner and outer periphery) at at least one position in the circumferential direction. A portion 31 is provided.

(Supplementary explanation 1)
Here, it is preferable that the above-described notch portion 31 has a depth just reaching the surface of the mounting surface portion 22. That is, it is most preferable that the notch portion 31 has a depth equal to the inner surface level of the mounting surface portion 22. This is because if the notch 31 is deeper than the inner surface level of the mounting surface portion 22, the rigidity of the mounting surface portion 22 may be unnecessarily lowered, and conversely, the notch portion 31 is lower than the inner surface level of the mounting surface portion 22. When the depth is shallow, the inward protruding edge 25 is not completely divided, and thus the effect of this embodiment cannot be sufficiently obtained. However, a slight variation in the depth of the notch 31 is allowed.

  Moreover, it is preferable that the notch part 31 is provided with respect to the inward protruding edge part 25 of the closed loop shape which surrounds the circumference | surroundings of the attachment surface side opening part 24 continuously. In other words, the means for manufacturing the branch joint 21 includes, for example, those by blow molding and those by injection molding. In this case, the inward protruding edge portion of the branch joint 21 manufactured by injection molding is used. It is preferable to provide a notch 31 with respect to 25.

  That is, in the case of injection molding, a relatively free shape can be obtained as long as the die can be removed. Therefore, a cylindrical mounting surface portion 22 having no depression as in the case of blow molding described later, and a narrow width The branch joint 21 having the inner projecting edge 25 having a closed loop shape can be obtained. The branch joint 21 by such injection molding is optimal for providing the notch portion 31 because the inwardly protruding edge portion 25 may be excessively increased in the shape of a complete closed loop. It becomes.

  On the other hand, in the case of blow molding, since the inner projecting edge 25 is formed by recessing the outer surface side of the mounting surface portion 22 and projecting it toward the inner surface side, the inner projecting edge 25 is formed around the entire circumference. Further, the inward protruding edge 25 is, for example, a wide U-shape when viewed from the inner surface side. That is, in the case of blow molding, the branch joint 21 has a mounting surface portion 22 having a depression and an inward protruding edge portion 25 having a wide U shape. In this case, the shape and rigidity of the inward protruding edge portion 25 and the mounting surface portion 22 are different from those in the case of injection molding. In addition, it is difficult to provide the notch 31. However, you may make it provide the notch part 31 in the case of blow molding.

(Configuration 2)
And the above-mentioned notch part 31 is provided in the part of the acute angle side 32 in which the attachment surface part 22 and the branch pipe part 23 branch in acute angle shape in the inward protrusion edge part 25. FIG.

(Supplementary explanation 2)
Here, the above-described notch portion 31 is provided with respect to the arc-shaped portion 25 a on the acute angle side 32 of the inward protruding edge portion 25. In this case, the cutout portion 31 is provided at a position on the width center line of the mounting surface portion 22 so as to extend in the axial direction of the cable protection tube.

  As a modification, a plurality of the above-described notches 31 can be provided. For example, as shown in phantom lines in FIG. 8, the notch portion 31 is formed on the obtuse angle side 33 where the mounting surface portion 22 and the branch pipe portion 23 branch at an acute angle in the inwardly projecting edge portion 25 in addition to the above. At least one or more of the portions (arc-shaped portion 25a, linear portion 25c, linear portion 25d) excluding the portion (arc-shaped portion 25b) can be provided.

  For example, by providing the notch 31 with respect to the linear portion 25c and the linear portion 25d described above, the portion with the largest deformation amount of the cable protection tube whose diameter has been reduced by residual stress by cutting the opening for branching. It is possible to intentionally improve the elastic deformation ability with respect to.

  At this time, by providing the notch 31 at the center in the axial direction of the linear portion 25c and the linear portion 25d, it is possible to improve the elastic deformation capability for the portion with the largest amount of deformation.

  Further, by providing the cutout portion 31 at a position closer to the arc-shaped portion 25a than the central portion in the axial direction of the linear portions 25c and 25d, it is possible to improve the elastic deformation capability around the arc-shaped portion 25a. Become.

  On the other hand, the arc-shaped portion 25b is difficult to directly provide the notch 31 in the arc-shaped portion 25b because the cables may be damaged due to rubbing against the notch 31 during the pull-in operation. By providing the cutout portion 31 at a position closer to the arc-shaped portion 25b than the central portion in the axial direction of the linear portion 25d, it is possible to improve the elastic deformation capability around the arc-shaped portion 25b. That is, instead of the arcuate part 25b where the notch 31 cannot be provided, the arcuate part 25b is provided by providing the notch 31 near the arcuate part 25b of the linear part 25c and the linear part 25d. It is possible to improve the elastic deformation capability with respect to the periphery of the arc-shaped portion 25b in substantially the same manner as provided.

  In these cases, it is preferable to provide the notch 31 so as to form a pair (one or a plurality of pairs) in both the linear portion 25c and the linear portion 25d.

  Further, by providing one or more notches 31 to the arc-shaped portion 25a, it is possible to optimally set or adjust the elastic deformation capability around the arc-shaped portion 25a.

  <Operation> The operation of this embodiment will be described below.

  When attaching the branch joint 21 to the cable protection tube, first, a branch opening is formed in the cable protection tube. This branching opening is processed manually on site.

  More specifically, on the outer surface of the cable protection tube, a planned opening portion having a shape that is the same as or slightly larger than the inward protruding edge portion 25 of the branch joint 21 is drawn with a marking line, and the inside of the marking line is dedicated to the inside. The opening for branching is formed by cutting using a tool or a general tool such as a hole saw (cutting process). The branch opening processed in the field has fine uneven burrs at the edges, so that deburring or other processing is necessary to prevent damage to cables due to such burrs. To do.

  Next, an adhesive is applied by hand coating around the inner surface of the attachment surface 22 of the branch joint 21 and the branch opening of the cable protection tube. As the adhesive, a vinyl chloride type or an epoxy resin type can be used.

  Then, the branch joint 21 to which the adhesive is applied is connected to the cable protection tube so that the inner projecting edge 25 is inserted into the branch opening and the inner surface of the mounting surface portion 22 is brought into contact with the outer surface of the cable protection tube. Attach to the tube (adhesion process). At this time, the inner projecting edge 25 is formed in an open loop shape surrounding the mounting surface side opening 24 so that the inner projecting edge 25 is formed with respect to the branch opening of the cable protection tube. Accurate positioning is possible.

  Finally, the branch joint 21 is secured to the outer periphery of the cable protection tube using a band member (not shown) (band fixing step).

  As described above, the branch joint 21 is attached to the cable protection tube.

  <Effect> According to this embodiment, the following effects can be obtained.

(Operation effect 1)
The above-described inwardly projecting edge portion 25 has the notch portion 31 that communicates between the inside and outside of the inwardly projecting edge portion 25 at at least one position in the circumferential direction, so that the mounting surface portion 22 is easily elastically deformed. Therefore, the adhesion of the mounting surface portion 22 to the outer surface of the cable protection tube can be enhanced. Moreover, since the surface area of the inward protruding edge portion 25 is increased by the cutout portion 31, heat dissipation when the branch joint 21 is formed is improved, so that the molding time can be shortened and the productivity can be improved.

  Thereby, even when there is a manufacturing error or the like in the cable protection tube or the branch joint 21, or even when the cable protection tube is partially reduced in diameter by residual stress by cutting the opening for branching. The branch joint 21 can be most effectively attached to the cable protection tube with the simplest and least costly structure. As a result, the branch joint 21 is tightly fixed to the cable protection tube without causing poor adhesion, and without causing a gap between the cable protection tube and the cable protection tube when the band joint member is secured. The

(Operation effect 2)
The above-described notch 31 is provided at the acute angle side 32 where the mounting surface portion 22 and the branch pipe portion 23 branch at an acute angle in the inwardly projecting edge portion 25, so that the mounting surface portion 22 is relatively rigid. Since the cutout 31 is provided around the portion which is difficult to be elastically deformed due to its height, and the portion where the gap is most likely to be formed between the cable protection pipe and the cable protection pipe, The adhesion of the mounting surface portion 22 to the outer surface of the cable protection tube of the surface portion 22 can be effectively increased. Further, since the portion on the acute angle side 32 described above is a place where the cables are difficult to be contacted when the cables are passed through the branch pipe portion 23, the cables may be damaged even if the notch 31 is provided. Is prevented.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the embodiments are only examples of the present invention, and the present invention is not limited to the configurations of the embodiments. Needless to say, design changes and the like within a range not departing from the gist of the invention are included in the present invention. Further, for example, when each embodiment includes a plurality of configurations, it is a matter of course that possible combinations of these configurations are included even if not specifically described. Further, when a plurality of embodiments and modifications are shown, it is needless to say that possible combinations of configurations extending over these are included even if not specifically described. Further, the configuration depicted in the drawings is of course included even if not particularly described. Further, when there is a term of “etc.”, it is used in the sense that the equivalent is included. In addition, when there are terms such as “almost”, “about”, “degree”, etc., they are used in the sense that they include those in the range and accuracy recognized by common sense.

21 Branch joint 22 Mounting surface portion 23 Branch pipe portion 24 Mounting surface side opening 25 Inwardly projecting edge portion 31 Notch portion 32 Acute angle side

Claims (1)

A mounting surface portion of a partial cylindrical surface that can come into contact with the outer surface of the cable protection tube, a branch tube portion projecting obliquely outward from the mounting surface portion, and an opening portion on the mounting surface side of the branch tube portion In the branch joint having an inward projecting edge portion projecting on the inner surface of the mounting surface portion so as to surround the entire edge portion and insertable into the branch opening formed in the cable protection tube,
The inwardly projecting edge, the position in the circumferential direction of the at least one location, and have a cutout portion communicating between the inner external inwardly protruding edge,
2. The branch joint according to claim 1, wherein the cutout portion is provided at a portion on the acute angle side where the attachment surface portion and the branch pipe portion branch at an acute angle in the inwardly protruding edge portion .