JP2902527B2 - Method of manufacturing cable for laying in pipeline - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cable for laying in a pipeline .
Regarding the manufacturing method, in particular, cable sheath, cushioning jacket,
And the formation of the hollow part and the placement of the inundation detection line in the same process.
The method of manufacturing a cable for laying in pipelines
I do.

[0002]

2. Description of the Related Art Conventionally, when moisture is frozen in a conduit in which a cable is laid, there is a problem in that the cable expands and compresses the cable, thereby deteriorating the characteristics of the cable and eventually causing the cable to be damaged. For this reason, as shown in FIG. 6, a cable provided with a buffer jacket 5 having a plurality of hollow portions 4 separated by protrusions 3 on the outer periphery of a cable sheath 2 is used for laying in a pipeline.

According to the above-mentioned cable, the plurality of hollow portions 4 between the outer periphery of the cable sheath 2 and the buffer jacket 5 are deformed when an external force is applied due to an increase in the volume of water due to freezing, and absorb pressure. It prevents the cable core 1 from being affected by external force.

In manufacturing such a cable for laying in a pipeline, a cable sheath 2 covering the cable core 1 and a buffer jacket 5 are manufactured in separate steps, and the projections of the cable sheath 2 and the buffer jacket 5 are formed. 3 are bonded to each other to integrate them.

[0005]

However, according to the conventional cable for laying in a pipeline, when the buffer jacket is damaged and water is immersed in the hollow portion, the function of absorbing the volume increase due to the freezing of the water is absorbed. However, there is a problem that the cable core is damaged or crushed.

In addition, since the cable sheath and the cushioning jacket are integrated by bonding, the degree of adhesion of the projection is weak, and when an external force is applied by bending of the cable or the like, separation occurs at the portion B of the projection 3 shown in FIG. . In this state, if the buffer jacket is damaged and water is immersed, there is a problem that all the hollow portions are immersed and frozen. In order to solve this problem, the flood detection line
Is provided, for example, in Japanese Utility Model Laid-Open No. 62-34712.
No., or proposed in Japanese Utility Model Laid-Open No. 1-155614.
Have been. According to the cable with the inundation detection wire,
Water can be detected early, minimizing damage
It can be suppressed and the damage spreads to other cables
Can be prevented. However, the conventional inundation detection line
According to the cable, the inundation detection wire is placed under the cable sheath.
Flood detection line is provided on the cable core
A process is required, and the manufacturing process is complicated. Accordingly, an object of the present invention is to provide a cable sheath, cushioning jacket, and hollow
The formation of the part and the placement of the inundation detection line in the same process
In-pipe laying that can simplify the manufacturing process
It is an object of the present invention to provide a method for manufacturing a cable for use in a vehicle .

[0007]

SUMMARY OF THE INVENTION The present invention is directed to the above-mentioned object.
A nipple for guiding the cable core and
First and second resin passages located on the outer periphery of the nipple
Around the cable core by a two-stage die with
Cable sheath provided and buffer outside located outside
In the method of manufacturing a cable for forming a sheath, the two-stage
An empty space is provided between the opening of the first and second resin passages of the chair.
Air holes and detection line insertion holes are provided, and air is sent from the air holes.
The cable sheath and the cushioning jacket.
To form a hollow portion in which the air is enclosed.
The water intrusion detection line from the detection line insertion hole
The water intrusion detection at least partially exposed in the hollow portion
Manufacture of cable for laying in pipeline characterized by providing wires
Provide a fabrication method.

[0008]

[0009]

When the cable core is guided by the nipple, the first
And the sheath material is cabled through the opening of the second resin passage.
Supplied on the core to form a cable sheath and cushioning jacket
Is done. At the same time, air is injected from the air hole and the detection line is inserted.
When the water detection line is supplied from the hole, the cable sheath
The outer jacket and hollow part are formed at the same time.
At least a part of the exposed water detection line is loose with the cable sheath.
It is located between the outer jackets. Naturally, air holes and detection wire insertion holes
Can be combined.

Hereinafter, a cable for laying in a pipeline according to the present invention will be described .
The fabrication method will be described in detail.

[0011] Figure 1 of the present invention conduit of laying cable
The cable for laying in a pipeline manufactured by the manufacturing method is shown, and a cable sheath 2 covering the outer periphery of the cable core 1 is shown.
And a buffer jacket 5 in which a plurality of hollow portions 4 are formed by the projections 3 on the outer periphery of the cable sheath 2.

The hollow portion 4 is provided with an immersion detecting circuit for forming an immersion detecting circuit.
A water detection line 6 is provided. The inundation detection line 6 detects an abnormality in the hollow portion 4 due to a decrease in insulation resistance when inundation occurs. For example, a configuration in which a coating on a conductor such as a copper wire is stripped at a certain interval, or And a tape made of plastic or the like wound on a conductor.

Next, a method for manufacturing a cable for laying in a pipeline according to the present invention will be described below with reference to FIG.
FIG. 2 shows an embodiment of a method for manufacturing a cable for laying in a pipeline according to the present invention, in which a nipple 7 for guiding a cable core 1 inserted from the direction of arrow A and a die 8 located on the outer peripheral portion of the nipple 7. It is composed of

The cross section of the die 8 includes a cable sheath 2
And a resin inlet 11 for forming the buffer jacket 5.
A passage 12 for the resin to be injected is provided.

Further, an air hole 13 is provided between the open ports of the passages 10 and 12, and a gas such as air is sent from the outside between the resin extruded from the die 8.

When the cable core 1 is guided by the nipple 7 and passes through the die 8, the cable core 1 is covered with resin that is simultaneously extruded from the passages 10 and 12. At this time, the hollow portion 4 is formed by the gas being sent from the air holes 13 between the resins to be extruded.
It is integrated around the cable core 1 as shown in FIG.
The cable sheath 2 having the hollow portion 4 and the buffer jacket 5 are formed.

At the time of the extrusion, a detection line for forming a water infiltration detection circuit is inserted through the air hole 13 together with the air, or an insertion hole is provided adjacent to the air hole 13, and the detection line is inserted from the insertion hole. By inserting the cable , the above-mentioned inundation detection line 6 can be built-in, and it is possible to provide an in-pipe laying cable having a function of detecting inundation due to damage to the buffer jacket 5 and peeling of the projection 3. Become.

According to the above-described apparatus for manufacturing a cable for laying in a pipeline, since the cable sheath 2 and the buffer jacket 5 are integrated, peeling of this portion is prevented.

Further, by simultaneously extruding the cable sheath 2 and the buffer jacket 5, the manufacturing process of the cable is simplified, so that the manufacturing of the cable can be performed efficiently and the cost is reduced. be able to.

FIG. 4 shows a cable for laying in a pipeline according to the present invention.
FIG. 1 shows another cable manufactured by the manufacturing method, and FIG.
A duplicate description of the same configuration as that described above will be omitted. FIG.
, The inundation detection line 6 has a hollow part 4
And has a configuration embedded in the inside of the projection 3 so as to be exposed to the outside.

FIG. 5 shows a cable for laying in a pipeline according to the present invention.
FIG. 1 shows another cable manufactured by the manufacturing method, and FIG.
A duplicate description of the same configuration as that of FIG. 4 is omitted. In FIG. 5, the inundation detection line 6 is a cable sheath 2
And the buffer jacket 5 is supported by the immersion detection line 6 .

[0022]

As described in the foregoing, according to the conduit manufacturing method of laying cable of the present invention, a first envelope that is performed in close contact with the cable core at its outer periphery by the two-stage die through the cable cores in the nipple A second casing integrated with the first casing via the hollow portion is formed, and the first and second casings are formed.
At the time of forming the outer cover, air flows into the hollow part through a two-stage die to form the hollow part, and water is detected through the insertion hole.
Supply of wires to simplify the manufacturing process.
Can be.

[Brief description of the drawings]

FIG. 1 shows a method for manufacturing a cable for laying in a pipeline according to the present invention .
FIG. 2 is a cross-sectional view showing a cable manufactured according to the first embodiment.

FIG. 2 shows one example of a method for manufacturing a cable for laying in a pipeline according to the present invention.
It is sectional drawing which shows an Example .

FIG. 3 shows a method for manufacturing a cable for laying in a pipeline according to the present invention .
FIG. 5 is a cross-sectional view showing a cable (water infiltration detection wire not shown) manufactured by the method described above.

FIG. 4 shows a method for manufacturing a cable for laying in a pipeline according to the present invention .
FIG. 2 is a cross-sectional view showing a cable manufactured according to the first embodiment.

FIG. 5 shows a method for manufacturing a cable for laying in a pipeline according to the present invention .
FIG. 2 is a cross-sectional view showing a cable manufactured according to the first embodiment.

FIG. 6 is a sectional view showing a conventional cable for laying in a pipeline.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cable core 2 Cable sheath 3 Protrusion 4 Hollow part 5 Buffer jacket 6 Water detection line 7 Nipple 8 Die 9 Resin inlet 10 Passage 11 Resin inlet 12 Passage 13 Air hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoyuki Otani 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Works, Hitachi Cable Co., Ltd. (72) Katsumi Hiruda, Inventor Hidaka-cho, Hitachi City, Ibaraki Prefecture 5-1-1, Hidaka Works, Hitachi, Ltd. (56) References JP-A-57-210509 (JP, A) JP-A 4-116315 (JP, U) JP-A 62-34712 (JP) , U) Hikaru 1-155614 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01B 7/32 H01B 13/24 H01B 13/14

Claims (1)

(57) [Claims] A nipple for guiding a cable core;
First and second resin passages located on the outer periphery of the nipple
Around the cable core by a two-stage die with
Cable sheath provided and buffer outside located outside
In the method of manufacturing a cable for forming a sheath, the first and second resin passages of the two-stage die are opened.
An air hole and a detection line insertion hole are provided between the
The cable sheath and the front
Forming a hollow portion in which the air is sealed between the buffer jackets.
And a flood detection line is sent from the detection line insertion hole.
By this, at least a part was exposed in the hollow portion
A cable for laying in a pipeline characterized by providing a flood detection line
Bull manufacturing method.