JPS63190512A - Joint construction of power cable submerged in high temperature water - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a connection structure for a high-temperature underwater power cable used to transmit power to equipment used in high-temperature, high-pressure water, such as a hot spring pump motor. It is.

[Background of the invention]

Equipment such as pump motors for hot spring pumping must be kept at a water temperature of 40°C.
It is often used underwater at ~130°C and a maximum water pressure of 30 kg f'/cm''.

Rubber/plastic power cables are generally used as power cables to send T-force to devices used in high-temperature, high-pressure water, and if the rubber/plastic power cables are long, connect them. May be used. And in that case the cable connection is
Since it will be exposed to high-temperature, high-pressure water, it must be of a structure that will not cause problems such as water seepage from the connection parts and deterioration of insulation. However, the conventional cable connection structure PI has not been able to withstand use in such high-temperature, high-pressure water; it has not been highly reliable.

The present invention has been made in view of the above-mentioned points, and provides a connection structure for a high-temperature underwater power cable that eliminates the above-mentioned problems and does not cause water seepage from the connection portion or deterioration of insulation even after long-term use. It's about doing.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has developed a pair of power cables in which the insulator layer and sheath at the end are peeled off in steps, and the core conductor and insulator layer are exposed to a predetermined length. A heat-shrinkable cylindrical body for core wire insulation coated with a heat-resistant adhesive on the inside is inserted into a predetermined portion of the exposed insulating layer including the contact portion, and the heat-shrinkable cylindrical body is allowed to heat-shrink and adhered, Furthermore, a heat-shrinkable cylindrical body for waterproof protection coated with a heat-resistant adhesive on the inside is inserted into a predetermined portion of the exposed sheath containing the heat-shrinkable cylindrical body for core wire insulation, and the heat-shrinkable cylindrical body is heat-shrinked and bonded to form a high-temperature underwater power cable. The connection structure was constructed.

[Effect]

By configuring the connection structure of a high-temperature underwater power cable as described above, the insulator is The layers and sheath are strongly tightened, and the heat-shrinkable cylindrical body for insulating the core wire and the insulation layer and the heat-shrinkable cylindrical body for waterproof protection and the sheath are pressure-bonded using a heat-resistant adhesive, so the connection area is extremely secure. Therefore, even if the cable connection part is exposed to high-temperature, high-pressure water for a long period of time, there will be no problem of water seepage or insulation deterioration.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing a connection structure of a high-temperature underwater power cable according to the present invention. In the same figure, 1 and 2 are rubber/plastic power cables, and the rubber/plastic power cable 1 is equipped with three core conductors 1-3,
The core wire conductors 1-3 are each covered with an insulator 1-2,
The insulator 1-2 is covered with a sheath 1-1. Rubber/
Similarly, the plastic power cable 2 has three core conductors 2.
-3, and the core conductors 2-3 each have an insulator 2-3.
2, and the insulator 2-2 is covered with a sheath 2-1.

As shown in the figure, the cable connection structure connects the end of the core conductor 1-3 of the rubber/plastic power cable 1 and the end of the core conductor 2-3 of the rubber/plastic power cable 2 electrically and mechanically. The core wires are connected to the core conductors 1-3 and 2-3, and a heat-resistant adhesive is coated on the inside of the predetermined portions of the insulators 1-2 and 2-2, including the connecting portions of the core wire conductors 1-3 and 2-3, and the core wires are inserted in advance. Heat-shrink the insulating heat-shrinkable cylindrical body 4 and press-bond it, and then apply heat-resistant adhesive on the inside to predetermined portions of the sheaths 1-1 and 2-1 containing the core wire insulating heat-shrinkable cylindrical body 4. A heat-shrinkable cylindrical body 5 for waterproof protection, which has been inserted in advance, is heat-shrinked and pressure-bonded.

The specific method for connecting the cables is as follows: First, the sheaths 1-1 of the rubber/plastic power cables 1 and 2 are connected.
2-1 and the insulators 1-2, 2-2 are peeled off to a predetermined length in steps, and the core conductor 1-3, the insulator 1-2.2-3 and the insulator 1-2.
Expose 2-2.

Next, the core conductor 1-3 and the core conductor 2-3 are electrically and mechanically connected by compression connection using a crimp sleeve, soldering, or the like.

An adhesive having heat resistance on the inside is inserted in advance over the circumference of either the insulator 1-2 or the insulator 2-2 prior to the connection of the core conductors 1-3 and 2-3. The heat-shrinkable cylindrical body 4 for core wire insulation coated with the agent is moved so that both ends thereof overlap the insulators 1-2 and 2-2 by a predetermined length, and the heat-shrinkable cylindrical body 4 for core wire insulation is heated. The inner surface of the heat-shrinkable cylindrical body 4 for insulating the core wire is pressed into close contact with the outer periphery of the insulator 1-2 and the insulator 2-2 due to the shrinkage force and the adhesive applied inside.

Next, in the same way, prior to connecting the core conductors 1-3 and 2-3, a heat-shrinkable cylindrical body for waterproof protection is inserted over the circumference of either the sheath 1-1 or the sheath 2-1. 5 and sheaths 1-1 and 2-1 with both ends thereof having a predetermined length.
The heat-shrinkable cylindrical body 5 for water protection is heated and contracted, and the inner surface of the heat-shrinkable cylindrical body 5 for waterproof protection becomes the same as the sheath 1 due to the shrinking force and the adhesive applied to the inside. -1 and the outer periphery of the sheath 2-1.

After connecting the ends of the rubber/plastic power cable 1 and the rubber/plastic power cable 2 as described above, as shown in FIG. 5 and the sheath 1-1 and the sheath 2-1, and then a heat-resistant protective tape is wrapped thereon to form taping portions 1-8 and 2-8, thereby completing the cable connection.

FIG. 2 is a diagram showing a connection structure of rubber/plastic power cables having different outer diameters. As shown in the figure, a sheath 1-1 and an insulator 1- of a rubber/plastic power cable 1 are shown.
2 is smaller than the outer diameters of the sheath 2-1 and the insulator 2-2 of the rubber-plastic power cable 2. As shown in the figure, a preheated shrinkable cylindrical body 7 for waterproof protection is bonded in advance to the sheath 1-1 with a small outer diameter by heat shrinkage, and a core wire is also bonded to the insulator 1-2, which also has a small outer diameter. The preheat-shrinkable cylindrical body 6 for insulation is bonded by heat-shrinking. As a result, the outer diameter of the preheat-shrinkable cylindrical body 7 for waterproof protection and the sheath 2-1 of the rubber/plastic power cable 2 are
The outer diameter of the preheat-shrinkable cylindrical body 6 for core wire insulation and the outer diameter of the insulator 2-2 of the rubber/plastic power cable 2 are substantially equal. Note that a heat-resistant adhesive is applied in advance to the inner surfaces of the preheat-shrinkable cylindrical body 7 for waterproof protection and the preheat-shrinkable cylindrical body 6 for core wire insulation, and the heat-resistant shrinkage force and this adhesive are used to pressure-bond them. .

After press-bonding the preheated shrinkable cylinder 7 for waterproof protection and the preheated shrinkable cylinder 6 for core wire insulation to the outer peripheries of the sheath 1-1 and insulator 1-2, respectively, as described above, the cable shown in FIG. In almost the same way as for the connection structure, connect the core conductor 1.
-3 and 2-3 are electrically and mechanically connected, and the heat-shrinkable cylindrical body 4 for core wire insulation, which has been coated with a heat-resistant adhesive on the inside in advance, and the insulators 1-2 and 2-2 are heated. Heat-shrinkable cylindrical body 5 for waterproof protection and sheaths 1-1 and 1-2 bonded together under shrinkage pressure and coated with a heat-resistant adhesive on the inside in advance
Perform heat shrinkage pressure bonding with.

Further, as shown in No. 3150, a highly heat-resistant self-fusion tape is wrapped around the ends of the heat-shrinkable cylindrical body 5 for waterproof protection and the pre-heat-shrinkable cylindrical body 7 for waterproof protection and the outer periphery of the sheath 1-1. A heat-resistant protective tape is wrapped on top to form the taping part 1-8, and a highly heat-resistant self-adhesive tape and heat-resistant protection are also applied to the other end of the heat-shrinkable cylindrical body 5 for waterproof protection and the outer periphery of the sheath 2-1. The tape is wound to form the taping portion 2-8, and the cable connection is completed. When using the power cable connection structure shown in Figures 1 to 3 above in warm water with a water temperature of 40°C to 130''C and a maximum water pressure of 3oCgr, the heat-shrinkable cylindrical body 4 for insulating the core wire
The heat-shrinkable cylindrical body 5 for waterproof protection has high heat resistance, and the adhesive applied on the inside has high heat resistance and has a high adhesion strength after melting by heating and high water pressure resistance. is necessary.

In addition, the wall thickness of the cylinder after heat shrinkage and the degree of penetration of the adhesive applied to the inside are determined by heating for core wire insulation with respect to the outer diameter dimensions of insulators 1-2, 2-2 and sheath 1-1, 2-1. It varies depending on the inner diameter dimensions of the shrinkable cylindrical body 4 and the heat-shrinkable cylindrical body 5 for waterproof protection.

In addition, the adhesion force of the heat-shrinkable cylindrical body 4 for core wire insulation and the heat-shrinkable cylindrical body 5 for waterproof protection to the insulator 1-2.2-2 and the sheath 1-1.2-1 after heat-shrinking is as follows: -2
．． It varies depending on the overlapping length of the heat-shrinkable cylindrical body 4 for core wire insulation and the heat-shrinkable cylindrical body 5 for waterproof protection with respect to the outer diameter dimensions of 2-2 and the sheath 1-1.2-1.

The wall thickness, adhesive penetration rate, and length of the heat-shrinkable cylindrical body 4 for core wire insulation and the heat-shrinkable cylindrical body 5 for waterproof protection will affect the electrical and mechanical strength of the cable connection if they are not appropriate. This is an extremely important matter.

FIG. 4 is a diagram showing the degree of shrinkage of the heat-shrinkable cylindrical body 5 for waterproof protection with respect to the diameter of the sheaths 1-1 and 2-1, and the vertical axis represents the inner diameter of the heat-shrinkable cylindrical body for waterproof protection and the outer diameter of the sheath ( ff
In the figure, the heat-shrinkable cylindrical body 5 for waterproof protection has an inner diameter of A-3811111 with a shrinkage of zero and a shrinkage of 100% (complete shrinkage after heating). (in the case of
-19m is used.

The heat-shrinkable cylindrical body 5 for waterproof protection has an inner diameter shrinkage degree of 6.
It has been confirmed from experience that it is best to select a material that has an outer diameter of 0% to 90% of the sheath 1-1.2-1.

FIG. 5 is a diagram showing the degree of shrinkage of the heat-shrinkable cylindrical body 4 for core wire insulation with respect to the diameter of the insulators 1-2 and 2-2. Diameter (1+
1111, and the horizontal axis shows the degree of shrinkage [%]. In the same figure, the heat-shrinkable cylindrical body 4 for core wire insulation has an inner diameter of A-13 mm at zero shrinkage and an inner diameter of B-51Tf at 100% shrinkage.
Il. The rubber/plastic power cable to be connected uses an insulator with an outer diameter of C-7.

The inner diameter of the heat-shrinkable cylindrical body 4 for core wire insulation has a shrinkage degree of 60.
It has been confirmed from experience that it is best to select a material that has the outer diameter of the insulator 1-2.2-2 within a range of 90% to 90%.

FIG. 6 shows the sheath 1-1 of the heat-shrinkable cylindrical body 5 for waterproof protection.
2-1 is a diagram showing the relationship between the overlap length and the outer diameter, where the vertical axis shows the overlap length (m1l) between the heat-shrinkable cylindrical body for waterproof protection and the sheath, and the horizontal axis shows the overlap length with respect to the sheath outer diameter d. In the same figure, the rubber/plastic power cable to be connected has a sheath outer diameter d.
-16.7mm1 is used.

It has been confirmed from experience that the overlapping length of the heat-shrinkable cylindrical body 5 for waterproof protection with respect to the outer diameter d of the sheath 1-1.2-i is preferably selected to be 2.5 or more.

FIG. 7 shows the insulator 1-2 of the heat-shrinkable cylindrical body 4 for core wire insulation.
2-2 is a diagram showing the relationship between the overlap length and the vertical axis is the overlap length between the heat-shrinkable cylinder for core wire insulation and the insulator [
], and the horizontal axis is the overlap length f with respect to the insulator outer diameter d.
(1/d).

In the figure, a rubber/plastic power cable to be connected has an insulator outer diameter of d-5, 911ffil.

It has been confirmed from experience that the overlapping length of the heat-shrinkable cylindrical body 4 for insulating the core wire should be selected to be at least 2.5 times the outer diameter d of the insulator 1-2.2-2.

As mentioned above, rubber/plastic power cables 1 and 2
The heat-shrinkable cylindrical body 4 for core wire insulation and the heat-shrinkable cylindrical body 5 for waterproof protection that are suitable for the outer diameter dimensions of the sheath 1-1.2-1 and the insulator 1-2.2-2 are limitedly applied. According to
These cylindrical bodies after being heated and shrunk will have an appropriate wall thickness, and will be able to withstand a certain degree of external impact, and will also be suitable for rubber/plastic power cables 1 and 2 when subjected to rapid heat cycles. This means that the cable can reasonably follow the movement of the cable due to expansion/contraction and bending of each part of 2.

By configuring the power cable connection structure as described above, the heat-shrinkable cylindrical body for core wire insulation and the heat-shrinkable cylindrical body for waterproof protection, which are limited to the dimensions of the power cable to be connected, are combined, and the set of materials is used as a connection kit. By doing so, not only high reliability can be maintained, but also cable connection work can be performed without requiring any advanced technology, and the work time can be significantly shortened.

It should be noted that the above embodiment is just an example of the present invention, and it goes without saying that the present invention is not limited to the above embodiment.

[Effects of the Invention] As explained above, according to the present invention, the heat-shrinkable cylindrical body for core wire insulation and the heat-shrinkable cylindrical body for waterproof protection are more insulating than heat-shrinkable and heat-resistant adhesive coated on the inside thereof. Since it is strongly pressure-bonded to the layer and sheath, its airtightness is extremely excellent, and even if the cable connection part is used for a long period of time in high-temperature, high-pressure water, it has the extremely excellent effect that there is almost no water intrusion or insulation deterioration.

In addition, an excellent effect can be obtained in that the cable connection work can be easily performed without requiring any special skills.

3 is a diagram showing the connection structure of the cable, and FIG. 3 is a diagram showing the appearance of the connection structure of the high-temperature underwater power cable according to the present invention.
The figure shows the degree of shrinkage of the heat-shrinkable cylinder for waterproof protection with respect to the sheath diameter. Figure 5 shows the degree of shrinkage of the heat-shrinkable cylinder for core wire insulation with respect to the insulator diameter. Figure 6 shows the degree of shrinkage of the heat-shrinkable cylinder for waterproof protection with respect to the diameter of the insulator. FIG. 7 is a diagram showing the relationship between the overlapping length of the shrinkable cylindrical body and the outer diameter of the sheath, and FIG. 7 is a diagram showing the relationship between the overlapping length of the heat-shrinkable cylindrical body for core wire insulation and the insulator.

In the figure, 1, 2...Rubber/plastic power cable, 1-1.2-1...Sheath, 1-2.2-2...
・・Insulator, 1-3.2-3・・・・Core conductor, 4・・
... Heat-shrinkable cylinder for core wire insulation, 5... Heat-shrinkable cylinder for waterproof protection, 6... Preheat-shrinkable cylinder for core wire insulation, 7... Preheat-shrinkable cylinder for waterproof protection. , 1-
8.2-8...Taping part.

Claims (4)

[Claims] (1) A pair of power cables in which the insulator layer and sheath at the end are peeled off in steps to expose the core conductor and insulator layer to a predetermined length, and the exposed core conductor is electrically and mechanically removed. A heat-shrinkable cylindrical body for insulating the core wire coated with a heat-resistant adhesive on the inside is inserted into a predetermined portion of the exposed insulating layer including the connection portion, and the core wire is heated and shrunk to be bonded. A heat-shrinkable cylindrical body for waterproof protection coated with a heat-resistant adhesive on the inside is inserted into a predetermined portion of the exposed sheath containing a heat-shrinkable cylindrical body for insulation, and is bonded by heat-shrinking. Connection structure of underwater power cable. (2) The heat-shrinkable cylindrical body for insulating the core wire and the heat-shrinkable cylindrical body for waterproof protection are pressure-bonded to the outer surfaces of the insulator layer and the sheath at a shrinkage degree of 60% to 90%. A connection structure for a high-temperature underwater power cable described in scope item (1). (3) The length of the overlapping portion of the heat-shrinkable cylindrical body for core wire insulation and the heat-shrinkable cylindrical body for waterproof protection, and the insulating layer and sheath is 2.5 times or more the outer diameter of the insulating layer and sheath. Claims (1) or (2) characterized in that:
) Connection structure of power cable for high-temperature underwater use as described in section 2. (4) A heat-resistant self-adhesive tape is wrapped around the stepped portion of the power cable sheath and the heat-shrinkable cylindrical body for waterproof protection to eliminate the step, and a heat-resistant protective tape is further wrapped on top of that. A connection structure for a high-temperature underwater power cable according to claim (1), (2), or (3).