JP7419954B2 - Fittings for cable protection tubes - Google Patents

Description

The present invention relates to a joint for a cable protection pipe.

2. Description of the Related Art Joints for cable protection pipes are known, which connect cable protection pipes for accommodating communication and power transmission cables and burying them underground. Patent Document 1 discloses a cylindrical joint main body into which a pipe material (cable protection tube) is inserted, a waterproof packing inserted into the joint main body and surrounding the pipe material, and a waterproof packing that comes into contact with the edge of the waterproof packing and is attached to the joint main body. A piping joint device (for cable protection pipes) equipped with a stopper ring with a C-shaped cross section that surrounds the pipe material, and a connection socket that is screwed to the connection part so that the stopper ring is tightened and pressed against the outer circumferential surface of the pipe material. joints) are disclosed. According to this pipe joint device, the pipe materials can be easily connected and fixed to each other by simply screwing in the connection socket after the pipe materials are inserted into the joint body provided with the waterproof packing.

Japanese Patent Application Publication No. 2000-291837

However, in the cable protection pipe joint disclosed in Patent Document 1, the connection between the cable protection pipe and the cable protection pipe joint is made through a packing, which is a press-compression member. When this happens, there is a problem in that the cable protection tube comes off from the cable protection tube joint. Furthermore, the flexibility of the cable protection pipe joint disclosed in Patent Document 1 to cope with movement and deformation of the cable protection pipe underground due to crustal deformation or earthquakes has not been sufficiently studied.

The present invention has been made in view of these problems, and aims to prevent cable protection tubes from becoming disconnected from each other due to force in the axial direction while maintaining tightness (sealing), and to protect cables. The purpose of the present invention is to provide a cable protection pipe joint that is flexible enough to handle deformation and movement of the pipe underground.

One aspect of the present invention for solving the above problems is a cable protection tube joint that connects two cable protection tubes, the two first cylindrical tubes being connected to one end of each cable protection tube. a second cylindrical member, the first cylindrical member being inserted into each end from the other end side; and two third cylindrical members that are screwed together and attached to each other to respectively restrict the first cylindrical member from coming off from the second cylindrical member, and the first cylindrical member includes a cable protection tube. A first connection part formed on one connectable end side, a protrusion part formed on the other end side, a collar formed between the first connection part and the protrusion part, and attached to the outer edge of the protrusion part. The second cylindrical member has an inner circumferential diameter smaller than the outer circumferential diameter of the collar portion, and has a protruding portion at each end so that the protruding portion can be inserted with the inner circumferential surface in contact with the inner circumferential surface. an insertion section formed on each side, an external thread section formed on the outer peripheral surface of each insertion section, and a cylindrical tube connecting the end of the insertion section opposite to the side where the protrusion is inserted. the third cylindrical member has an inner circumferential diameter larger than the outer circumferential diameter of the brim portion, an inner circumferential diameter smaller than the outer circumferential diameter of the brim portion of the first cylindrical member; An edge that is larger than the outer circumferential diameter of the area between the first connecting part and the collar of the first cylindrical member and is formed at one end and a predetermined distance away from the edge towards the other end. and an internal threaded part that can be screwed into the external threaded part, and when the protruding part of the first cylindrical member is inserted into the insertion part and the external threaded part and the internal threaded part are screwed together, The flange portion is housed between the second cylindrical member and the edge on the inner periphery of the third cylindrical member, thereby preventing the protruding portion from coming out of the insertion portion and maintaining the tightness of the close member. In the maintained state, the first cylindrical member is movable within a predetermined range in a direction along the central axis of the second cylindrical member and the third cylindrical member and in a direction inclined with respect to the central axis. , a joint for cable protection pipes.

According to the present invention, while maintaining tightness (sealing), it is possible to prevent the cable protection tubes from becoming disconnected from each other due to force in the axial direction, and to prevent the cable protection tubes from deforming or moving underground. It is possible to provide a cable protection pipe joint that is flexible enough to accommodate various applications.

A vertical cross-sectional view of a cable protection pipe joint according to the first embodiment of the present invention A partially enlarged sectional view of a cable protection pipe joint according to the first embodiment of the present invention A longitudinal sectional view illustrating the movement of the cable protection pipe joint according to the first embodiment of the present invention A longitudinal sectional view illustrating the movement of the cable protection pipe joint according to the first embodiment of the present invention A partially enlarged sectional view of a cable protection pipe joint according to a modification of the first embodiment of the present invention A vertical cross-sectional view of a cable protection pipe joint according to a second embodiment of the present invention A cross-sectional view of a cable protection pipe joint according to a second embodiment of the present invention

[First embodiment]
A cable protection pipe joint 100 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of a cable protection pipe joint 100, and FIG. 2 is a partially enlarged cross-sectional view of a section A surrounded by a dotted line in FIG.

The cable protection pipe joint 100 is used to connect two cable protection pipes 1 that accommodate communication and power transmission cables and are buried underground. The cable protection pipe joint 100 includes two first cylindrical members 10, one second cylindrical member 20, and two third cylindrical members 30.

(First cylindrical member)
The first cylindrical member 10 is a cylindrical member to which the cable protection tube 1 can be connected at one end, and has a first connecting portion 11, a protruding portion 12, a collar portion 13, and a close member 14.

The first connecting portion 11 is a cylindrical portion formed on one end side of the first cylindrical member 10 to which the cable protection tube 1 can be connected. The cable protection tube 1 is inserted into the first connecting portion 11 and joined to the inner peripheral surface of the first connecting portion 11 by adhesive, welding, or the like.

The protruding portion 12 is a portion that is inserted into each end of the second cylindrical member 20 and extends outward on the other end side of the first cylindrical member 10 . The protruding part 12 has a recess 12a formed in its outer edge, and a close member 14 provided in the recess 12a on one end side of the second cylindrical member 20 to closely (seal) between the protruding part 12 and an insertion part 22, which will be described later. is installed. The close contact member 14 tightly (seals) the insertion portion 22 and the protruding portion 12, thereby preventing moisture and dust from entering the inside of the cable protection tube 1 and contaminating the housed cable. The close member 14 is, for example, an O-ring, but is not limited thereto as long as it can bring the second cylindrical member 20 and the protrusion 12 into close contact (sealing).

The flange portion 13 is a flange-shaped portion that extends outward between the first connecting portion 11 and the protrusion 12 in order to prevent the protrusion 12 from coming off the second cylindrical member 20. It is.

(Second cylindrical member)
The second cylindrical member 20 is a cylindrical member into which one first cylindrical member 10 can be inserted from the other end side, and includes a connecting portion 21 and two insertion portions 22. , two external threaded portions 23, two first ribs 24, and an IC tag 25.

The insertion portion 22 is a cylindrical portion for inserting the protrusion 12 of the first cylindrical member 10 into each end of the second cylindrical member 20 . The inner circumferential diameter of the insertion portion 22 is smaller than the outer circumferential diameter of the collar portion 13. In addition, the inner circumferential diameter of the insertion portion 22 is set to a predetermined tightening value that allows the protrusion 12 to be inserted thereinto, and that allows for close contact (sealing) with the close member 14 by inserting the protrusion 12. It is formed to a size with a width.

The connecting portion 21 is a cylindrical portion that connects the two insertion portions 22 to each other in the axial direction. The connecting portion 21 is provided so as to connect the ends of the two insertion portions 22 opposite to the side into which the protruding portion 12 is inserted. When the connecting portion 21 connects the two insertion portions 22, as shown in FIG. 1, the ends of the two insertion portions 22 on the opposite side to the side where the protruding portion 12 is inserted communicate with each other.

The external threaded portion 23 is an external thread formed on the outer circumferential surface of each of the insertion portions 22 in order to screw together an internal threaded portion 32 of a third cylindrical member 30, which will be described later. For example, the external threaded portion 23 is formed on the outer circumferential surface of the end of the insertion portion 22 on the side into which the protruding portion 12 is inserted. In order to facilitate attachment of the third cylindrical member 30, the threads of the external threaded portion 23 are preferably formed so that the screwing is completed by less than one rotation of the relative rotation.

When the third cylindrical member 30 is screwed onto the outer peripheral surface of the second cylindrical member 20, the first rib 24 engages with a second rib 33 of the third cylindrical member 30, which will be described later. It constitutes a lock structure that prevents the screw from loosening. The first rib 24 is, for example, a rib formed on the outer circumferential surface of each of the insertion portions 22 at a position a predetermined distance away from the external threaded portion 23 toward the connecting portion 21 over the entire circumference in the circumferential direction. Note that the first rib 24 may be formed only in a predetermined range in the circumferential direction as long as loosening of the screw engagement can be prevented.

The IC tag 25 has predetermined information recorded on an internal IC chip (not shown), and is provided to read the information from the ground using radio waves after the cable protection tube joint 100 is buried. For example, the IC tag 25 is attached by pasting it into a groove 26 with a depth of about 1 mm formed on the outer peripheral surface of one of the insertion sections 22 in a region between the external threaded section 23 and the first rib 24. There is. The area between the external threaded part 23 and the first rib 24 is kept sealed by the threaded engagement of the external threaded part 23 with the internal threaded part 32 and the engagement of the first rib 24 with the second rib 33. . Therefore, the function of the IC tag 25 attached to the area is prevented from being impaired due to intrusion of rainwater, dust, etc. from the outside. The information recorded on the IC chip included in the IC tag 25 is not particularly limited, and, for example, geographical information on the location where the cable protection pipe joint 100 is buried can be recorded, and this information can be used in a guidance system, etc. can do. Note that the IC tag 25 may or may not be provided. Further, the IC tag 25 may be provided in both of the two insertion sections 22.

(Third cylindrical member)
The third cylindrical member 30 is attached to the outer circumferential surface of the second cylindrical member 20 from each end side by screwing, and restricts the first cylindrical member 10 from coming off from the second cylindrical member 20. This member has an edge 31, an internal thread 32, and a second rib 33. The inner circumferential diameter of the portion between the edge 31 and the internal threaded portion 32 of the third cylindrical member 30 is larger than the outer circumferential diameter of the collar portion 13 . As an example, the third cylindrical member 30 has a hexagonal cylindrical shape with a cylindrical inner peripheral surface. Thereby, the third cylindrical member 30 can be easily attached to the second cylindrical member 20 using a tool such as a spanner.

The edge portion 31 is a portion formed on one end side of the third cylindrical member 30 and extending inward. The inner circumferential diameter of the edge portion 31 is smaller than the outer circumferential diameter of the collar portion 13 of the first cylindrical member 10 and is smaller than the outer circumferential diameter of the collar portion 13 of the first cylindrical member 10 . It is formed larger than the outer circumferential diameter.

The internal threaded portion 32 is an internal thread formed for screwing the external threaded portion 23 of the second cylindrical member 20 and fixing the third cylindrical member 30 to the outer peripheral surface of the second cylindrical member 20. It is. The internal threaded portion 32 is formed at a position a predetermined distance away from the edge 31 toward the other end. Similarly to the external threaded part 23, the thread of the internal threaded part 32 is also formed so that the screwing can be completed by relative rotation of less than one revolution in order to facilitate attachment to the second cylindrical member 20. It is preferable.

The second rib 33 engages with the first rib 24 of the second cylindrical member 20 when the third cylindrical member 30 is attached to the outer peripheral surface of the second cylindrical member 20 by screwing. Constructs a lock structure that prevents loosening. The second rib 33 is, for example, a rib formed on the inner circumferential surface of the third cylindrical member 30 at a predetermined distance away from the inner threaded portion 32 toward the other end side over the entire circumference in the circumferential direction. Note that the second rib 33 may be formed only in a predetermined range in the circumferential direction, as long as loosening of the screw engagement can be prevented.

The first cylindrical member 10, the second cylindrical member 20, and the third cylindrical member 30 can all be manufactured using a resin material. For example, in order to increase heat resistance and strength, a material obtained by mixing (copolymerizing) vinyl chloride and ABS resin can be used. Further, the close contact member 14 can be manufactured using butadiene rubber, and silicone may be mixed therein to impart heat resistance, or fluorine may be mixed therein to impart acid resistance and alkali resistance. Good too.

The cable protection pipe joint 100 can be assembled by the following procedure. First, the protruding parts 12 of the first cylindrical member 10 to which the close members 14 are attached are inserted into the two insertion parts 22 of the second cylindrical member 20, one each. Thereafter, a third cylindrical member 30 is attached to the outer peripheral surface of the two insertion portions 22 of the second cylindrical member 20, with the first connecting portion 11 of the first cylindrical member 10 passed through the inner periphery of the internal threaded portion 32, respectively. It is fitted externally. Further, by relatively rotating the second cylindrical member 20 and the third cylindrical member 30, the outer threaded part 23 and the inner threaded part 32 are screwed together, and the cable protection pipe joint 100 is assembled. state. When the outer threaded portion 23 and the inner threaded portion 32 are screwed together, the first rib 24 and the second rib 33 are engaged in the axial direction, so that the screwing is prevented from loosening.

In this way, the cable protection tube joint 100 is constructed by inserting the first cylindrical member 10 into the two insertion portions 22 of the second cylindrical member 20, and then inserting the first cylindrical member 10 into the second cylindrical member 20. Assembly is possible by a relatively simple operation of rotating the third cylindrical member 30 relatively. In particular, if the outer threaded portion 23 and the inner threaded portion 32 are formed of screws that complete their screw engagement by relative rotation of less than one revolution, assembly of the cable protection pipe joint 100 will be easier.

In this way, the protruding part 12 of the first cylindrical member 10 is inserted into the insertion part 22, and the cable protection pipe joint 100 in which the external threaded part 23 and the internal threaded part 32 are screwed together is produced as shown in FIG. Then, each collar portion 13 is housed in a space S between each end of the second cylindrical member 20 and the edge 31 on the inner circumference of the third cylindrical member 30. Thereby, the collar portion 13 housed in the space S can move within a predetermined range inside the space S, and as a result, the first cylindrical member 10 is moved between the second cylindrical member 20 and the second cylindrical member 20. It is possible to move within a predetermined range described below in a direction along the central axis of the three-cylindrical member 30 and in a direction inclined with respect to the central axis.

As described above, the inner circumferential diameter of the edge portion 31 and the insertion portion 22 of the second cylindrical member 20 is smaller than the outer circumferential diameter of the collar portion 13 . Therefore, movement of the flange portion 13 accommodated in the space S in the axial direction is restricted between the end surface on the one end side of the insertion portion 22 and the edge portion 31. As a result, the range of movement of the first cylindrical member 10 in the axial direction is restricted, and when a force in the axial direction is applied, the first cylindrical member 10 comes off from the third cylindrical member 30, and the two cable protection tubes 1 Disconnection from each other is regulated. FIG. 3 is a cross-sectional view showing a state in which the collar portion 13 is in contact with the edge portion 31.

The amount of movement of the first cylindrical member 10 in the axial direction can be adjusted by the distance D between the edge 31 and the end surface of the insertion portion 22 on the edge 31 side (see FIG. 3). The distance D can be set arbitrarily, but as an example, it can be set to about 40 mm, which is the distance at which the expansion/contraction margin is 1% when the longest 4M pipe in the standard size is used as the cable protection tube 1. can. In addition, since the cable protection tube joint 100 allows the two first cylindrical members 10 to move in the axial direction, the two cables to be connected can move in the axial direction. A large range of relative movement between the protective tubes 1 in the axial direction can be ensured.

Further, as described above, the inner circumferential diameter of the edge portion 31 is formed larger than the outer circumferential diameter of the first cylindrical member 10 in the region R. Therefore, the outer peripheral surface of the collar 13 accommodated in the space S contacts the inner peripheral surface of the third cylindrical member 30, or the outer peripheral surface of the region R of the first cylindrical member 10 contacts the edge 31. It can be tilted until it abuts the inner circumferential surface. FIG. 4 is a cross-sectional view showing a state in which the outer circumferential surface of the collar portion 13 is in contact with the inner circumferential surface of the third cylindrical member 30. As shown in FIG.

The inclination angle of the first cylindrical member 10 with respect to the central axis of the second cylindrical member 20 and the third cylindrical member 30 is determined by the difference between the outer circumferential diameter of the collar portion 13 and the inner circumferential diameter of the third cylindrical member 30, and can be adjusted by the difference between the outer circumferential diameter of the first cylindrical member 10 and the inner circumferential diameter of the edge 31 in the region R. The inclination angle θ (see FIG. 4) of the first cylindrical member 10 with respect to the central axis of the second cylindrical member 20 and the third cylindrical member 30 can be, for example, about 6°. In particular, in the cable protection pipe joint 100, the two first cylindrical members 10 can be inclined with respect to the central axes of the second cylindrical member 20 and the third cylindrical member 30, respectively. Compared to the case where only the member 10 is provided, a larger range of relative inclination between the two connected cable protection tubes 1 can be ensured.

Furthermore, the distance in the axial direction between the protruding part 12 and the collar part 13 is such that the collar part 13 is in contact with the surface on the other end side of the edge part 31, and the outer circumferential surface of the collar part 13 is in a third cylindrical shape. When the close contact member 14 is in contact with the inner peripheral surface of the member 30 or in the inclined state until the outer peripheral surface of the first cylindrical member 10 in the region R contacts the inner peripheral surface of the edge 31, the close contact member 14 contacts the insertion portion 22. It is formed so as to be in contact with the inner circumferential surface of the tube to ensure close contact (sealing). As a result, in the cable protection pipe joint 100, the first cylindrical member 10 is aligned with respect to the direction along the central axis of the second cylindrical member 20 and the third cylindrical member 30, and in the direction inclined with respect to the central axis. Even when moving within a predetermined range, the close contact (sealing) of the close contact member 14 can be maintained.

Note that when the first cylindrical member 10 is inclined with respect to the central axis, as shown in FIG. Although a gap CL is generated, even in such a state, since the close contact member 14 is in contact with the inner peripheral surface of the insertion portion 22, close contact (sealing) is ensured. The angular range of the gap CL in the circumferential direction when viewed from the extending direction of the central axis is preferably 180° or less when viewed from the central axis so as to prevent the collar 13 from coming off from the edge 31. In order to reliably prevent the first cylindrical member 10 and the third cylindrical member 30 from coming off even if they are deformed, it is more preferable that the angle is 140° or less when viewed from the central axis.

As explained above, the cable protection tube joint 100 is designed to prevent the protruding part from coming out of the insertion part 22 while maintaining the close contact (sealing) of the close member 14. 10 is movable within a predetermined range in a direction along the central axis of the second cylindrical member 20 and the third cylindrical member 30 and in a direction inclined with respect to the central axis. Therefore, even if a crustal movement or an earthquake occurs, the connection between the two cable protection pipes 1 is prevented from coming apart while maintaining closeness (sealing), and the cable protection pipe 1 is kept underground. It is possible to flexibly respond to the deformation and movement of the cables, and suitably protect the accommodated cables.

In addition, since the two first cylindrical members 10 of the cable protection pipe joint 100 are movable within a predetermined range, the cable protection pipe joint 100 is more flexible than the case where only one first cylindrical member 10 is provided. A large relative movement range between the tubes 1 can be ensured. Therefore, the bent shape that was conventionally achieved by connecting a plurality of cable protection pipe joints having a predetermined curvature can be achieved with one or a small number of cable protection pipe joints 100.

Moreover, since the two first cylindrical members 10 are provided symmetrically across the connecting portion 21, the cable protection pipe joint 100 has no directionality in the axial direction. For this reason, the operation of inserting the cable protection tube 1 into the first cylindrical member 10 is simple, since there is no need to consider the orientation of the cable protection tube joint 100.

(Modified example)
The cable protection pipe joint 100 has a locking structure that prevents the screwing state between the outer threaded part 23 and the inner threaded part 32 from loosening by engaging the first rib 24 and the second rib 33. is not limited to this form. For example, in the lock structure, a protrusion (not shown) provided between the threads of at least one of the first rib 24 and the second rib 33 passes over the protrusion and engages the other thread. It may be configured to prevent rotation in the uncoupling direction.

The cable protection tube joint 100 also includes a positioning mark (not shown) on the surface of the region R of the first cylindrical member 10 for determining the position of the first cylindrical member 10 when the cable protection tube joint 100 is assembled. ) may be provided. The positioning mark is located near the edge 31 in the region R with the collar 13 located approximately midway in the axial direction between the end of the insertion portion 22 on one end side and the surface on the other end of the edge 31. It is formed at a location located at . The first cylindrical member 10, which has been positioned using the positioning mark, can be moved within a predetermined range to both one end and the other end. Therefore, if the cable protection pipe joint 100 is buried with the first cylindrical member 10 biased toward one end or the other end, the first cylindrical member 10 may move in one direction underground. can be prevented from becoming impossible. Note that the positioning mark may be a linear mark drawn so that the position can be visually confirmed, or may be a convex portion or a concave portion that allows the position to be confirmed by touching.

Further, the position where the IC tag 25 is provided is not limited to the above-mentioned position as long as the sealing property can be maintained inside the cable protection tube joint 100. Specifically, in the IC tag 25, the external threaded part 23 and the internal threaded part 32 are screwed together, and the third cylindrical member 30 covers the connecting part 21 side of the external threaded part 23 of the second cylindrical member 20. In this state, it may be provided between the connecting portion 21 side of the external threaded portion 23 of the second cylindrical member 20 and the third cylindrical member 30 covering the second cylindrical member 20 . Further, the method of sealing the position where the IC tag 25 is provided is not limited to the above embodiment. (a) to (c) of FIG. 5 are partially enlarged cross-sectional views showing the position where the IC tag 25 is provided and the sealing method of the joint for a cable protection tube according to a modified example.

In FIG. 5A, the IC tag 25 is provided in the groove 26 provided on the outer peripheral surface of the second cylindrical member 20, and the IC tag 25 protrudes from the outer peripheral surface of the second cylindrical member 20 at one end side and at the other end. A configuration in which a pair of first sealing ribs 27 are provided to seal the end side is shown.

In FIG. 5B, the IC tag 25 is provided in the groove 26, and in addition to the first sealing rib 27, the IC tag 25 is protruded from the inner peripheral surface of the third cylindrical member 30 on one end side and the other end side. A configuration in which a pair of second sealing ribs 34 are provided for sealing is shown. According to the form shown in FIG. 5(b), the first sealing rib 27 and the second sealing rib 34 seal one end side and the other end side of the IC tag 25, so that the configuration shown in FIG. 5(a) A higher sealing performance can be achieved compared to the embodiment shown. In this case, the first rib 24 and the second rib 33 that constitute the lock structure may be used as the first sealing rib 27 and the second sealing rib 34 on the other end side.

FIG. 5(c) shows that the IC tag 25 is provided in a groove 35 with a depth of about 1 mm provided on the inner circumferential surface of the third cylindrical member 30 without providing the groove 26, and A configuration is shown in which a pair of close members 28 are attached to recesses formed on the surface to seal one end and the other end of the IC tag 25. According to the form shown in FIG. 5(c), one end side and the other end side of the IC tag 25 are sealed with the close contact member 28, so that the form shown in FIGS. Comparatively, higher sealing performance can be achieved.

Note that the grooves 26 and 35 may or may not be provided. Further, the first sealing rib 27 and the second sealing rib 34 may be formed over the entire circumference in the circumferential direction as long as they can seal the IC tag 25, or may be formed only in a predetermined range in the circumferential direction. Good too.

[Second embodiment]
The cable protection pipe joint 101 according to the present embodiment is different from the cable protection pipe joint 100 according to the first embodiment in that the position of the first cylindrical member 10 is placed on the inner circumferential surface of the third cylindrical member 30 during assembly. It is provided with protrusions 36a and 36b for determining. FIG. 6 is a longitudinal cross-sectional view of the cable protection tube joint 101 provided with the projections 36a and 36b, and FIG. 7 is a cross-sectional view of the cable protection tube joint 101 taken along the line BB'.

The protrusions 36a and 36b are provided for positioning the first cylindrical member 10 at a predetermined position of the cable protection pipe joint 101. As shown in FIG. 6, the protrusions 36a and 36b are in contact with surfaces of one end (protrusion 36a) and the other end (protrusion 36b) of the collar 13 of the first cylindrical member 10, respectively. It is formed to protrude from the inner peripheral surface between the edge 31 and the internal threaded part 32 of the third cylindrical member 30 . As shown in FIG. 7, as an example, three protrusions 36a and 36b are formed at one end and the other end of the collar 13, for a total of six protrusions. However, the number of protrusions 36a and 36b is not limited to this as long as positioning in the direction along the central axis of the first cylindrical member 10 is possible; One or more, and two or more in total is sufficient.

Typically, the protrusions 36a and 36b are provided at positions such that when the cable protection tube joint 101 is assembled, the collar 13 is placed between the end of the insertion portion 22 on one end side and the surface of the other end of the edge 31. The position can be set approximately midway in the axial direction between the two. As a result, the cable protection pipe joint 101 is buried with the first cylindrical member 10 biased toward one end or the other end, making it impossible to move the first cylindrical member 10 in one direction underground. can be prevented from becoming

For example, the protrusion height of the protrusions 36a and 36b from the inner circumferential surface of the third cylindrical member 30 is such that when a predetermined force is applied to the first cylindrical member 10 in the axial direction, the height of the protrusion from the flange 13 designed to a height that can be climbed over. Thereby, after being buried, the first cylindrical member 10, on which a predetermined force is applied due to crustal deformation or an earthquake, can move in the axial direction as the collar portion 13 climbs over the protrusions 36a and 36b. Further, the protrusions 36a and 36b may be formed so as to be broken by a force acting on the first cylindrical member 10, thereby allowing the first cylindrical member 10 to move in the axial direction. .

Since the cable protection pipe joint 101 includes the protrusion 36b, like the cable protection pipe joint 100, the third cylindrical member 30 is attached to the outer peripheral surface of the second cylindrical member 20 into which the first cylindrical member 10 is inserted. It is difficult to move it to the side and fit it on. For this reason, in the cable protection pipe joint 101, for example, when the third cylindrical member 30 is externally fitted onto the outer peripheral surface of the second cylindrical member 20, the first cylindrical member 10 is attached to the collar portion 13 so that the protrusion 36b The first cylindrical member 10 may be tilted to an angle at which it can overcome the protrusion 36b, and then the first cylindrical member 10 may be returned to its original position after the flange 13 has climbed over the protrusion 36b. Thereby, the third cylindrical member 30 can be externally fitted onto the flange portion 13 without the flange portion 13 butting against the protrusion portion 36b.

Furthermore, in order to facilitate assembly, the collar portion 13 may include a notch through which the protrusion 36b of the third cylindrical member 30 that moves in the axial direction can pass. As a result, even if the third cylindrical member 30 is moved toward the other end and fitted onto the outer peripheral surface of the second cylindrical member 20 into which the first cylindrical member 10 has been inserted, the protrusion 36b is Since it can pass through the notch, there is no need to tilt the first cylindrical member 10 during assembly. After the third cylindrical member 30 is fitted onto the outer peripheral surface of the second cylindrical member 20, the first cylindrical member 10 is rotated by a predetermined angle around the central axis to open the notch in the flange portion 13. It is possible to prevent the first cylindrical member 10 from coming off in one end direction due to the passage of the protrusion 36b.

INDUSTRIAL APPLICABILITY The present invention can be used for burying cables underground for communication and power transmission.

1 Cable protection tube 10 First cylindrical member 11 First connection portion 12 Projection portion 13 Flange portion 14 Close contact member 20 Second cylindrical member 21 Connecting portion 22 Insertion portion 23 External thread portion 24 First rib 25 IC tag 26 Groove 27 First sealing rib 28 Close member 30 Third cylindrical member 31 Edge 32 Internal thread 33 Second rib 34 Second sealing rib 35 Groove 36a, 36b Projection 100, 101 Cable protection tube joint

Claims (4)

A cable protection pipe joint for connecting two cable protection pipes,
two first cylindrical members to which each of the cable protection tubes can be connected at one end;
a second cylindrical member in which one of the first cylindrical members is inserted into each end from the other end side;
two third cylinders that are screwed and attached to the outer circumferential surface of the second cylindrical member from each end side, and respectively restrict the first cylindrical member from coming off from the second cylindrical member; and a shaped member;
The first cylindrical member is
a first connection portion formed on the one end side to which the cable protection tube can be connected;
a protrusion formed on the other end side;
a collar formed between the first connection part and the protrusion;
and a close contact member attached to the outer edge of the protrusion,
The second cylindrical member is
an insertion portion having an inner circumferential diameter smaller than an outer circumferential diameter of the flange portion and formed on each end side so that the protruding portion can be inserted with the close contact member in contact with the inner circumferential surface;
an external threaded portion formed on the outer peripheral surface of each of the insertion portions;
a cylindrical connecting part that connects ends of the insertion part opposite to the side where the protruding part is inserted;
The third cylindrical member is
The inner circumferential diameter of the brim portion is larger than the outer circumferential diameter,
an inner circumferential diameter is smaller than an outer circumferential diameter of the brim portion of the first cylindrical member and larger than an outer circumferential diameter of a region between the first connecting portion and the brim portion of the first cylindrical member; , an edge formed on one end side;
an internally threaded portion that is formed at a predetermined distance from the edge toward the other end and that can be screwed into the externally threaded portion;
In a state in which the protruding part of the first cylindrical member is inserted into the insertion part and the external threaded part and the internal threaded part are screwed together, the collar part is connected to the inner periphery of the third cylindrical member. by being accommodated between the second cylindrical member and the edge,
In a state where the protruding part is restricted from coming out of the insertion part and the closeness of the close contact member is maintained,
The first cylindrical member is movable within a predetermined range in a direction along a central axis of the second cylindrical member and the third cylindrical member and in a direction inclined with respect to the central axis.
Fitting for cable protection tube. comprising a lock structure that restricts the screwing state between the external threaded portion and the internal threaded portion from being released;
The cable protection pipe joint according to claim 1. In a state where the external threaded part and the internal threaded part are screwed together, and the third cylindrical member covers the connecting part side of the external threaded part of the second cylindrical member,
an IC tag is provided between the connecting portion side of the external threaded portion of the second cylindrical member and the third cylindrical member covering the second cylindrical member;
The cable protection pipe joint according to claim 1 or 2. The IC tag is
A first rib formed on the outer circumferential surface between the externally threaded portion and the connecting portion of the second cylindrical member, and the third cylindrical member more than the internally threaded portion of the third cylindrical member. hermetically sealed by at least one of the second ribs formed on the inner circumferential surface of the other end;
The cable protection pipe joint according to claim 3.

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