JP2003333721A - Connecting structure of cable covered with metal tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting structure for a cable covered with a metal tube, which can stabilize the strength by enabling prevention of bad welding without needing accurate positioning of a laser beam application position at laser welding, and besides is higher in strength than a conventional one. <P>SOLUTION: Within an axially overlapping region between a sleeve and a metal tube, bead parts are made continuous or interrupted in the circumferential directions of the sleeve and the metal tube, and the above sleeve and the above metallic tube are welded together with a laser beam. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal for connecting two metal pipe ends to each other by welding a sleeve inserted into the two metal pipe ends and the respective metal pipe ends. The present invention relates to a connection structure for a pipe covered cable.

[0002]

2. Description of the Related Art A metal tube-coated cable is known in which a cable such as an optical fiber or a coated copper wire is coated with a metal tube for protection. In such a metal tube-coated cable, since the protective coating of the cable is metal, it has high mechanical strength, so it can be made thinner and lighter, and has high reliability as a cable for communication and measurement. is doing.

When such a metal tube-covered cable is used as a submarine cable, an ocean observation cable, etc., the metal tube-covered cable is laid over a long distance. Lengthening of the metal tube itself of the tube-coated cable is required.

However, when manufacturing a metal tube, it is difficult to continuously form a single metal tube to lengthen it, because of restrictions imposed by materials and manufacturing lines.

Therefore, as disclosed in Japanese Patent No. 2670382, Japanese Patent No. 2790912, Japanese Patent No. 2836033, etc., the length of the metal pipe itself has been increased by connecting the metal pipes.

In these prior arts, as shown in FIGS. 7 and 8, a metal sleeve 52 and a metal tube 51 are attached to the ends of two metal tube-coated cables C containing cables 54. Both ends of the sleeve 52 were welded to both metal pipes 51 along the circumferential direction while being externally inserted so as to straddle the other metal pipe 51.

Further, as welding for connecting the metal tubes of the metal tube-covered cable with the sleeve, laser welding,
Brazing, TIG welding, etc. are known. However, with brazing, it is difficult to weld in a small area and heat is applied over a relatively wide area.Therefore, the temperature rises up to the periphery of the welded part and damages the cable core wire such as optical fiber and coated copper wire. Probability is high. Further, in TIG welding, it is difficult to fit the thickness of the bead portion within the thickness of the metal tube for a thin and thin metal tube, and a protrusion due to the bead portion is generated in the metal tube, and the bead portion and the cable are Since the core wire is close to the core wire, the heat from the bead portion is likely to damage the cable core wire. Therefore, conventionally, laser welding, which enables highly accurate welding, has been most used.

[0008]

However, in the above-described conventional metal pipe-covered cable connection structure, since the welded portion is located at both ends of the sleeve, this portion is accurately aligned with the laser irradiation position in the axial direction. I have to keep it. However, due to factors such as the limitation of positioning accuracy of the laser irradiation position and lack of experience of the operator, the laser irradiation position deviates from the above welding position and welding failure occurs, resulting in a decrease in strength at the welding site. easy.

Further, in laser welding, since the laser beam is focused on a small spot diameter so that a high power density can be obtained, it is difficult to adjust the laser irradiation position to the welding position also in this point. The irradiation position is easily displaced from the welding position. In particular, if the end surface of the sleeve is not exactly perpendicular to the axial direction or has a wavy shape, the welding position is set to the laser irradiation position and the axis line because the spot diameter of the laser beam is small as described above. Even if the positions are accurately matched at one position in the circumferential direction, the laser irradiation position gradually shifts from the welding position during welding in the circumferential direction.

Therefore, according to the present invention, it is possible to prevent welding defects and to stabilize the strength without requiring accurate positioning of the laser irradiation position during laser welding, and a connection structure for a metal tube coated cable. For the purpose of providing. It is another object of the present invention to provide a connection structure for a metal tube covered cable having higher strength than conventional ones.

[0011]

SUMMARY OF THE INVENTION According to the present invention, the above object is a metal-tube-covered cable connection structure in which a cable is covered with a metal tube, and the connection structure is inserted into two metal tube ends. In the connection structure of the metal pipe-coated cable in which the two metal pipe ends are connected to each other by welding the sleeve and the respective metal pipe ends, in the overlapping region in the axial direction of the sleeve and the metal pipe, This is achieved by forming a bead portion continuously or intermittently along the circumferential direction of the sleeve and the metal pipe and laser-welding the sleeve and the metal pipe.

In the present invention, it is sufficient that the laser irradiation position during laser welding is within the overlapping region of the sleeve and the metal pipe in the axial direction, and since this region is wider than the width of the bead portion, it is as in the conventional case. The laser irradiation position does not have to be exactly aligned with the end of the sleeve or the metal tube in the axial direction. Therefore, it is possible to prevent welding defects and stabilize the strength without requiring accurate positioning of the laser irradiation position during laser welding.

In the present invention, the cable refers to an optical fiber or a coated copper wire, and a cable protected by a metal tube is referred to as a metal tube coated cable.

A plurality of the bead portions may be formed at intervals in the axial direction. As a result, the strength (tensileness) is improved, and in this case, if the distance between the beads is increased, the torsional strength is particularly improved.

The bead portion may include at least one circumferential bead portion extending in the circumferential direction and an axial bead portion extending in the axial direction. As a result, the strength is improved, and the longer the axial bead portion, the more the twist strength is improved. Also, in this case,
A plurality of the circumferential bead portions may be formed. Thereby, the strength (tensile strength) is improved. Further, in this case, a plurality of the axial bead portions may be formed for one circumferential bead portion. Thereby, the strength is improved.

Further, the bead portion may be formed as one bead portion having a circumferential component and an axial component. This makes it possible to improve the strength in a simplified connecting process. For example, in this case, the bead portion is formed in a wavy shape or a zigzag shape in the circumferential direction.

Further, a sealing material for sealing between the sleeve and the metal pipe may be applied to an end portion of the sleeve or the metal pipe in the axial direction. This eliminates the need for a bead between the sleeve and the metal tube to be hermetically sealed so that there is no need to form a bead over the entire circumferential direction during laser welding, so the process for laser welding is It can be simplified.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, referring to FIGS. 1 and 2, a schematic structure of a metal pipe-covered cable connection structure according to this embodiment will be described. FIG. 1 is a diagram showing a schematic configuration of a connection structure of such a metal tube covered cable, and FIG. 2 is an enlarged perspective view of a connection structure portion of the metal tube covered cable of FIG.

The metal tube-coated cable of this embodiment is shown in FIG.
As shown in FIG. 1, a cable (not shown) is covered with the metal tube 1. The metal tube covered cable has a structure in which the sleeve 2 inserted into the ends of the two metal tubes 1 and the ends of the respective metal tubes 1 are welded to each other so that the two metal tubes 1 are connected to each other. Is doing.

In this embodiment, within the overlapping region L of the ends of the sleeve 2 and the metal pipe 1 in the axial direction, the width a is continuously provided over the entire circumferential direction of the sleeve 2 and the metal pipe 1.
Sleeve 2 and metal tube 1 so that the bead portion 3 of
And are laser welded. Incidentally, the sleeve 2 and the metal tube 1
The bead portion may be a part of the circumferential direction or may be intermittent as long as it is within the overlapping region L in the axial direction of
It is preferable that the bead portion 3 is continuously formed over the entire area in the circumferential direction as in the present embodiment because the strength is increased.

Next, the connecting process of the metal tube covered cable in this embodiment will be described with reference to FIG.

FIG. 3 is a diagram showing a process of connecting the metal tube-coated cable in this embodiment.

First, as shown in FIG. 3A, the cable 4 is exposed by removing the metal pipe 1 of a predetermined length at the end portions of the two metal pipe-covered cables C, and one of The sleeve 2 to the metal tube 1 (on the right). In this state, the cable 4 is connected.

Next, as shown in FIG. 3B, the sleeve 2 is moved in the axial direction to a position where the sleeve 2 straddles the end of one metal pipe 1 and the end of the other metal pipe 1.

Then, as shown in FIG. 3C,
The laser irradiation position in the axial direction is determined so that the laser irradiation position in the axial direction is within the overlapping region in the axial direction of the sleeve 2 and the metallic pipe 1 at the end of the one metal-tube covered cable C.
In this state, by irradiating the laser while rotating the sleeve 2 and the metal tube 1 relative to the laser welding device about the axis, the bead portion 3 is formed in the circumferential direction of the sleeve 2 and the metal tube 1. The sleeve 2 and the metal tube 1 are laser-welded as described above.

Further, as shown in FIG. 3D, also at the end portion of the other metal tube-coated cable C,
The sleeve 2 and the metal tube 1 are laser-welded to complete the cable connecting step.

As described above, according to this embodiment, the laser irradiation position during laser welding is set to the sleeve 2 and the metal pipe 1.
It suffices that the area be wider than the width of the bead portion 3 because the area is wider than the width of the bead portion 3, so that the laser irradiation position is axially in the axial direction in the end portion of the sleeve 2 or the metal tube 1. Does not have to match exactly.
Therefore, it is possible to prevent welding defects and stabilize the strength without requiring accurate positioning of the laser irradiation position during laser welding.

As described above, since the area for forming the bead portion is wide, the number and shape of the bead portion can be various, and the strength is improved by the number and shape of the bead portion. be able to. Here, the shape of the bead portion will be described with an example.

For example, as shown in FIG. 4A, a plurality of bead portions 13 may be formed at intervals in the axial direction.
By doing so, the strength (tensileness) is improved, and if the distance between the beads is increased, the torsional strength is also improved.

Further, as shown in FIG. 4B, at least one circumferential bead portion 23a extending in the circumferential direction is formed.
And an axial bead portion 23 formed to extend in the axial direction.
The bead portion 23 formed by b may be used. In this case, as shown in FIG. 4B, the axial bead portion 23b is preferably formed at a plurality of circumferential positions with respect to one circumferential bead portion 23a. Also, the circumferential bead portion 23
A plurality of a's may be formed, which is desirable for improving the strength.

Further, as shown in FIGS. 4 (c) and 4 (d),
The bead portion may be formed as one bead portion having both a circumferential component and an axial component. That is, as shown in FIG. 4C, the bead portion 33 having a zigzag shape is formed.
Alternatively, as shown in FIG. 4D, the corrugated bead portion 43 may be formed in the circumferential direction. In this case, it is possible to continuously irradiate the laser, so that FIG.
It is possible to obtain the same strength as that of the bead portion 23 shown in (1) in a simplified connecting step.

Further, in this embodiment, an example in which the sleeve 2 is externally inserted and connected to the metal tube 1 has been described.
The sleeve 12 may be inserted into the metal tube 11 as shown in FIG. This is useful when it is necessary to reduce the outer diameter of the metal tube-coated cable.

Further, as shown in FIG. 6, a seal material 5 for sealing between the sleeve 2 and the metal tube 1 may be applied to the axial end portion of the sleeve 2 or the metal tube 1. in this case,
The bead 23b between the sleeve 2 and the metal tube 1 does not need to be hermetically sealed so that it is not necessary to form a bead over the entire circumferential direction at the time of laser welding. It can be simplified. Further, the application of the sealing material 5 to the end portion of the sleeve 2 or the metal tube 1 in the axial direction does not have a harmful effect due to heat unlike welding.
Moreover, the positioning is simple and a reliable seal can be made.

[0035]

As described above, according to the present invention,
In the overlapping region of the sleeve and the metal pipe in the axial direction, the bead portion is continuously or intermittently formed over the circumferential direction of the sleeve or the metal pipe to laser-weld the sleeve and the metal pipe, Since the welding position in the axial direction is wider than the width of the bead, it is possible to prevent welding defects and stabilize strength without requiring accurate positioning of the laser irradiation position during laser welding. You can Further, by forming a plurality of bead portions within the above-mentioned region or forming axial bead portions, it becomes possible to obtain a metal tube covered cable having higher strength than conventional cables.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a metal tube-coated cable according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a connection structure portion of the metal tube covered cable shown in FIG.

FIG. 3 is a diagram for explaining a connecting step of the connecting structure for the metal tube-covered cable according to the embodiment of the present invention.

FIG. 4 is a diagram showing an example of a metal pipe-covered cable connection structure according to another embodiment of the present invention.

FIG. 5 is a diagram showing an example of a connection structure for a metal tube covered cable according to another embodiment of the present invention.

FIG. 6 is a diagram showing an example of a connection structure for a metal tube covered cable according to another embodiment of the present invention.

FIG. 7 is a front view showing a schematic configuration of a conventional metal tube-coated cable.

FIG. 8 is a diagram for explaining a connecting step in the connecting structure for the metal tube-covered cable of FIG. 7.

[Explanation of symbols]

1 Metal Tube 2 Sleeve 3 Bead Part 4 Cable 5 Sealing Material 13 Bead Part 23 (23a, 23b) Bead Part (Circumferential Bead Part,
Axial direction bead portion) 33 bead portion 43 bead portion 3 bead portion C metal tube covered cable L area

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4E068 BG02 DA09                 5G355 AA10 BA04 BA14 CA15 CA26                 5G375 AA14 BA26 BB72 BB74 CA02                       CA14 CD07 DB11 DB35 EA17

Claims (8)

[Claims] 1. A connection structure for a metal tube-covered cable, which is obtained by coating a cable with a metal tube, wherein a sleeve inserted into two metal tube ends and each metal tube end are welded. In the connection structure of the metal tube covered cable in which the ends of the two metal tubes are connected to each other by the above, in the overlapping region in the axial direction of the sleeve and the metal tube, the sleeve and the metal tube are continuously provided in the circumferential direction. Alternatively, a connection structure for a metal-tube-covered cable is characterized in that a bead portion is intermittently formed and the sleeve and the metal tube are laser-welded. 2. The connection structure for a metal tube covered cable according to claim 1, wherein a plurality of bead portions are formed at intervals in the axial direction. 3. The bead portion includes at least one circumferential bead portion formed to extend in the circumferential direction and an axial bead portion formed to extend in the axial direction. Connection structure for metal tube coated cables. 4. The connection structure for a metal tube covered cable according to claim 3, wherein a plurality of circumferential bead portions are formed. 5. The connection structure for a metal tube covered cable according to claim 3, wherein a plurality of axial bead portions are formed for one circumferential bead portion. 6. The connection structure for a metal tube covered cable according to claim 1, wherein the bead portion is formed as one bead portion having a circumferential component and an axial component. 7. The bead portion is formed in a wavy or zigzag shape and is formed in the circumferential direction.
The connection structure for a metal tube-covered cable as described in. 8. A sealing material for sealing between the sleeve and the metal pipe is applied to an end portion of the sleeve or the metal pipe in the axial direction, as described in any one of claims 1 to 7. Connection structure for metal tube coated cables.