JPH097725A - Joining method for electric wires by explosive pressure of explosive compound - Google Patents

Abstract

PURPOSE: To provide the joining method for joining electric cables not by mechanical compression or squeezing effects but by a metallurgical junction joining not only the part exposed outside of the stranded cables but also their inner layer parts without giving any damage to the cables, when stranded cables made of aluminum or its alloys used as transmission and distribution lines, stranded cables made of copper or its alloys, aluminum cables steel reinforced (ACSR) and the like, are joined by making use of explosion pressure. CONSTITUTION: This invention is concerned with a joining method where a protective body which is made of metal identical to the material of the outer layers of stranded cables, is formed into a pipelike curved surface in advance, is covered over the outer circumference of the cables to be joined, a flying body is disposed at the outer side of the protective body which is made of metal identical to the material of the protective body, and flies in by the explosion pressure of explosives so as to be hit against the protective body, and the flying body, the protective body and the cables are thereby metallurgically and integrally joined. The explosives are set in such a way as to enclose a flying tube, let the explosives progress from one end of the explosives to the other end progressively. It is so designed that the progressing speed of explosion (explosion speed) is less than 70% of the sound speed of the metal for the outer layers of the cables to be joined, and the flying speed of the flying tube in the direction perpendicularly intersected with the progressing direction of explosion, is sufficient enough to join the stranded cable themseves in the inner layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a transmission and distribution line with an explosive pressure of explosive, and in particular, by integrally metallurgically joining a flight tube, a protective tube and an electric wire, a small amount of explosive and a high strength. It is a method of obtaining a highly reliable joint with excellent weather resistance, and can be implemented even in remote areas of the mountains where it is difficult to use power such as electric power and machinery, and since the amount of explosive used is small, a lightweight explosion-proof silencer can be used. It is a method that can be used and can be easily implemented without pollution of explosion noise even in areas with many houses.

[0002]

2. Description of the Related Art In the conventional method of joining transmission and distribution lines by the explosive pressure of explosives, the ends of the lines to be joined are butted against each other in a metal pipe, and the outside of the metal pipe is thick (about 10 mm) rubber or the like. Wrap the detonating wire over the elastic protective body of
By detonating the detonating wire, the metal tube was contracted, and the electric wire was mechanically compressed or joined by caulking. As a patent document of the prior art, Japanese Patent Publication No. 51-25592.
There are gazettes of Japanese Utility Model Publication No. 58-32865.

According to this method, the detonating speed of the detonating wire is higher than or substantially equal to the sound speed of the metal used for the electric wire, and in such a case, it is known that the metal cannot be metallurgically joined by the detoning pressure. Has been. In addition, by covering the outside of the metal tube with an elastic protective body such as thick rubber and winding a detonating wire around it, the elastic protective body attenuates the explosion pressure transmitted to the metal tube. The need to use detonators results in more explosive charge than is needed to simply join the metal tubes by compression or caulking.

Further, since the joining by mechanical compression has a lower joining strength as compared with the metallurgical joining, it is necessary to make the joining portion of the electric wire have a large length. It was one of the many factors. In addition, mechanically compressing metal pipes and joining them by tightening the stress is not reliable, and rainwater and corrosive gas are generated in the gap between the metal pipe and the electric wire and the twisted wire of the electric wire. There is a big problem that the connection part that has entered and joined by such a method contains a large residual stress because the metal is subjected to strong working due to the strong pressure of the explosion, and is corroded more easily than other parts. It was

[0005]

Problems to be Solved by the Invention In order to eliminate the drawbacks of the above-mentioned conventional method of joining electric wires due to the explosion of explosives, there were the following problems. (1) In order to prevent rainwater and gas from entering the joints, the joints should be metallurgically joined to the inside of the flight tube, the protection tube and the stranded wire without using mechanical caulking, and the gap between the stranded wires should be Need to be blocked to prevent them from entering. For this purpose, it is necessary to use explosives having an explosive velocity lower than that of the detonating fuse and thus a low explosive pressure, which may increase the amount of explosives used. (2) If a thick protective layer is not provided between the explosive and the metal tube in order to reduce the amount of the explosive used, the metal tube or the electric wire for joining may be damaged by the explosion pressure. (3) A strong explosive force is required to join even the twisted wires in the inner layer of the wire, and as a result, if the flight tube collides directly with the wire and is attempted to join, the wire may be greatly deformed or, in some cases, broken. There is. As a result of conducting many theoretical and experimental studies on these problems, the inventors have reached the following conclusions.

[0006]

[Means for Solving the Problem] It is considered that the above problems can be solved by taking the following measures. Each number corresponds to the above-mentioned problem number. (1) When it becomes possible to metallurgically join the flight tube, the protection tube, and the inside of the stranded wire, the strength of the joint has the original strength of the metal forming the joint or higher than that of the conventional metal. It has much higher strength than the mechanical compression and caulking joints that do not involve metallurgical joints due to the explosive joining method. Therefore, in the conventional method, the wire length is, for example, 300 m.
While the strength was secured by providing a joint portion having a length of m or 500 mm, for example, the explosive can be joined by shortening the joint portion length while securing the strength of the conventional joining method or more by joining the joint portion with 100 mm or less. The amount is less than conventional. Also, as will be described in detail in the next section, by eliminating the thick elastic protective layer,
By preventing the decay of the explosion pressure transmitted to the joint, it is possible to reduce the amount of explosive.

(2) When the amount of explosive is reduced by eliminating the thick protective layer, the metal tube or the electric wire may be damaged by the explosive pressure. Uses powdered or plastic explosives instead of the explosives described above to prevent imprinting of the debris traces on the metal surface, and protects the flight tube that directly contacts the explosives by enclosing the wires. Preventing the electric wire from being damaged by colliding it with the electric wire through a metal tube (protective tube) and the flying tube directly colliding with the electric wire, and metallurgically joining both the flying tube and the protective tube to the electric wire. Thus, sufficient bonding strength is obtained. By these means, it is possible to obtain a metallurgical bond having a high bond strength with a small amount of explosive without scratching the electric wire.

(3) In order to prevent the electric wire from being largely deformed or broken by treating it with a strong explosive force such that the twisted wires in the inner layer of the electric wire are joined together, a thick rubber protective layer is used in (2). The protection tube that was considered to be used to eliminate it works effectively as it is.

The structure of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a typical embodiment of the present invention, 1 is explosive, 2 is explosive when explosive 1 is powdery, explosive case made of paper or plastic for storing it, 3 is flying Tube 4
A thin protective material for protecting the surface of the spacer 5, a spacer 7 for maintaining an appropriate distance between the flight tube 4 and the protection tube 7,
Is a spacer for maintaining an appropriate distance between the surface of the protective tube 6 and the surface of the electric wire 8, 9 is an electric detonator for detonating explosives,
Reference numeral 10 is a detonating wire for quickly transmitting the detonation by the electric detonator 9 to the entire circumference of the explosive 1.

To bond metals, the explosive 1 is required to explode at an explosive velocity lower than or equal to the sound velocity (hereinafter referred to as the sound velocity) of the longitudinal waves of those metals. However, in the present invention, in order to satisfactorily bond all of the parts constituting the joint, it is often necessary that the parts explode at a speed not higher than 70% of the sonic speed of those metals. It became clear as a result of the experiment. For example, in the case of pure aluminum,
The speed of sound is 6,420 m / sec, but 70% of that 4,
It is necessary to be 494 m / sec or less. 4,494
Many explosives that explode at an explosive velocity of m / sec or less are known, and many industrial explosives can be used in addition to those listed in the examples of the present invention. Can be selected easily by referring to.

The explosive case 2 for accommodating the explosive 1 is merely for holding the explosive in a predetermined shape and in a predetermined place, and may be made of any material as long as it achieves the purpose. Further, if the explosive 1 is plastic and can retain its own shape without a container, it may not be used. In the present invention, since the protective material 3 uses the powdery or plastic explosive, it does not use the detonating wire as in the conventional method.
There is no risk of linear scratches, so a thin coating film or a tape made of plastic or paper may be applied, and a thickness of 1 mm or less is sufficient. The material of the flight tube 4 is substantially the same as that of the electric wire, and the flight tube 4 needs to have a shape described in detail later.

The spacer 5 is for maintaining an appropriate distance between the flight tube 4 and the protection tube 6, which will be described later in detail together with the requirements of the explosive 1 and the flight tube 4. Since the protective tube 6 is subject to electrolytic corrosion if it is made of a material different from that of the electric wire 8, it must be made of the same material as the electric wire 8 together with the flight tube 4 and the spacer 5. That is, when the electric wire 8 is a copper wire, the flight tube 4, the spacer 5 and the protection tube 6 must be copper or a copper alloy, and when the electric wire 8 is an aluminum wire, it must be aluminum or an aluminum alloy. Further, when the electric wire 8 is an ACSR (steel core aluminum stranded wire) type electric wire in which the outer layer is an aluminum alloy and the inner layer (center layer) is steel, the flight tube 4, the spacer 5, and the protection tube are selected according to the material of the outer layer. 6 must be aluminum or an aluminum alloy.

Similarly to the spacer 5, the spacer 7 also has an electric wire 8.
It is for maintaining an appropriate distance between the protective tube 6 and the protective tube 6, and needs to be made of the same material as the electric wire 8. Electric detonator 9
Is for detonating explosive 1 and is connected to a detonating wire 10 which is provided around one end of explosive 1 in order to rapidly convey the explosion to the entire circumference of explosive 1. It is not always necessary, and the detonator 9 may be brought into contact with one point of the end of the explosive 1 to initiate the detonation, which is within the discretion of the joint planner.

FIG. 2 is an enlarged sectional view of the vicinity of the explosive portion in the process in which the explosive 1 is detonated by the detonator 9 through the detonating wire 10 and explodes in FIG. 1'in the figure
Is the explosive in the process of exploding, and DF is the detonation wave front at the boundary of the process where explosive explodes into gas. The arrow D indicates the explosion speed, the arrow Vp indicates the speed perpendicular to the traveling direction of the explosion in which the flight tube 4'is blown to the side opposite to the explosive by the explosion pressure, and the arrow Vg indicates the protection tube 6'colliding with the flight tube 4 '. The speed at which the electric wire 8'is blown in the direction perpendicular to the explosion progressing direction by the impact, the arrow Vh indicates the speed at which the flight tube 4'progresses the protection tube 6'in the explosion direction, and the arrow Vh.
u is the speed at which the point where the protective tube 6'collides with the electric wire 8'progresses in the explosion direction.

What is important here is that the explosive 1, the flight tube 4, the protection tube 6 and the electric wire 8 are all arranged in parallel with each other in FIG. 1 and that they are arranged concentrically. Therefore, the speed D of the explosion, the speed Vh of the flight tube 4 ′ traveling in the explosion direction at the point of collision with the protection tube 6 ′, and the speed Vh of the point of the protection tube 6 ′ colliding with the electric wire 8 ′ in the explosion direction. All of Vu are equal. Further, as a requirement of the present invention, all of these velocities must be 70% or less of the sound velocity of the metal to be joined. That is, assuming that the speed of sound of metal is C, it can be expressed as 0.7C> D = Vh = Vu ... 1).

Further, in order to satisfy the achievement requirement that the inner layer portion of the electric wire 8'consisting of the stranded wire of the present invention is joined,
The velocity Vp of the flight tube 4'in the direction perpendicular to the explosion traveling direction is an extremely important factor. If Vp is too low, the inner layer of the wire is stupid, and the flight tube 4'and the protection tube 6'cannot be joined, and even if it is achieved, even the surfaces of the protection tube 6'and the wire 8'cannot be joined. possible. Further, even if the surfaces of the flying tube 4'and the protective tube 6'and the surface of the protective tube 6'and the electric wire 8'can be joined, the object of the present invention cannot be achieved unless the stranded wires in the inner layer portion of the electric wire 8'are joined. .

The inventors arrived at the following conclusion as a result of repeating many experiments and theoretical studies. That is, in order to join even the stranded wires in the inner layer portion of the electric wire 8, an energy of a certain amount or more per volume of the electric wire 8 which is determined for each material type of the electric wire 8 is input to the electric wire 8 as kinetic energy due to the flight of the flight tube 4. It is necessary to do so. For example, in the case of the electric wire 8 made of a stranded aluminum wire, it has been found that it is necessary to input energy of 400 Mj or more per 1 m ^{3 of the} volume including the void inside the electric wire 8. In the case of a stranded copper wire, it is necessary to input energy of 900 Mj or more. The reason why the material of the electric wire 8 is different between aluminum and copper is that copper has higher deformation resistance and melting point than aluminum.
It is considered that good bonding cannot be achieved unless larger energy is applied.

The method of giving the required velocity Vp to the flight tube 4 can be determined as follows. An appropriate amount of explosive is attached to the flight tube 4 with reference to the embodiment of the present invention, and the process of exploding the explosive and causing the flight tube 4 to fly toward the inside of the tube is photographed by flash X-rays. There is a method of judging from the inclination angle of 4. Further, by arranging pins which are electrical contacts inside the flight tube 4 at different distances and electrically shorting one after another in the process of deformation of the flight tube 4, an electrical recording means such as an oscilloscope is used. A method of recording and judging from the distance-time relationship is also effective. Many of these methods are described in reference books, textbooks, and the like regarding the measurement of the explosion phenomenon, and those skilled in the art can easily implement them by referring to them.

As a means for determining an effective dose without using these measuring means, each value is set with reference to the embodiment of the present invention, actual bonding is performed, and the bonded electric wire 8 is used.
There is a method of cutting and inspecting and inspecting conditions under which good bonding can be obtained by gradually increasing the amount of explosive if the inner layer of the electric wire 8 is not bonded. On the contrary, the wire 8 is broken,
When a large flaw occurs at the joint, the amount of explosive may be too large, so the dose should be gradually reduced to set an amount that can obtain an appropriate joint.

The distance between the flight tube 4 and the protection tube 6, or the size of the spacer 5 which determines the distance, is important for determining the velocity Vp in the direction perpendicular to the explosion in which the flight tube 4 collides with the protection tube 6. Play a role. That is, the explosion speed is 70% of the speed of sound of metal
When accelerating a metal plate or tube with the following explosives, its speed increases with the flight distance, and when the thickness of the metal tube as the flight tube used in the present invention is about 5 mm or less, the flight distance is about 10 mm. Until the flight speed increases. Therefore, in order to effectively join with a small amount, it is advantageous that the distance between the flight tube 4 and the protection tube 6 is large up to about 10 mm. Since it is prevented from being deformed by flight, it sometimes causes breakage of the flight tube 4 in the course of flight or interferes with the role of protecting the electric wire 8 by biting into the protection tube 6 too much. Things are often at a disadvantage. Again, those skilled in the art can easily set an appropriate value with reference to the present specification. The spacer 5 may be installed around the tubes of the flight tube 4 and the protection tube 6 around the entire circumference thereof, or several metal pieces may be arranged on the circumference at equal distances. The flight tube 4 and the protection tube 6 may be arranged as concentric circles.

The thicknesses of the flight tube 4 and the protection tube 6 are determined in consideration of the following factors. After the joining is performed, the flight tube 4 and the protection tube 6 take charge of the mechanical strength of the electric wire at the joining portion and also serve as an electric path when a current flows from one electric wire to the other electric wire. First, in order to guarantee the mechanical strength of the electric wire, the following requirements must be met. All electric wires are specified by standards, and a certain level of breaking strength must be guaranteed for each type. Assuming that the allowable strength is F, the cross-sectional area of the flying tube 4 is Sf, the cross-sectional area of the protective tube 6 is Su, and the flying tube 4 and the protective tube 6 are made of the same material, the breaking strength per unit cross-sectional area is f. Then, Sf and Su may be set so as to satisfy f (Sf + Su)> F ....

Next, regarding the cross-sectional area or the thickness distribution of the flight tube 4 and the protection tube 6, the thickness of the flight tube 4 is determined by the flight speed and the resulting energy input for joining. Involved in the decision. From the above, if the flight speed of the flight tube 4 is known, how much energy is input to the joint can be obtained by the following equation. ^{E = mVp 2/2 ············· 3} ) where, E is the kinetic energy of the flying tube 4, m is the mass of the flight tube 4. If this E reaches the energy required for the above-mentioned joining, the requirement for joining is satisfied.

The thickness of the protective tube 6 differs from that of the flying tube 4 in that the thickness of the flying tube 4 is related to the input energy E.
When it collides with the electric wire 8
It must be thick enough to prevent scratches and breakage, and must be determined empirically. However, it is possible to avoid setting the thickness of the protective tube 6 to be 50% or more thicker than the thickness of the flight tube. However, this can also be easily determined by those skilled in the art with reference to the present specification.

The distance between the protective tube 6 and the electric wire 8 or the dimension of the spacer 7 which determines the distance does not have to be as strict as in the case of the spacer 5. The reason is that the vertical velocity Vg at which the flight tube 4 collides with the protection tube 6 and is blown toward the electric wire 8 when the thickness of the protection tube 6 is equal to or less than the thickness of the flight tube 4. If so, it may be considered to be almost equal to Vp at a level slightly lower than the vertical velocity Vp of the flight tube 4, and it is a problem if the required input energy requirement described above is achieved. Because it is not so good.
Generally, the distance between the protective tube 6 and the electric wire 8 or the dimension of the spacer 7 for determining the distance may be set between 0.1 mm and 1 mm, but may be shorter or longer if necessary. . The shape of the spacer 7 may be similar to that of the spacer 5.

As a matter of course, it is preferable that the flight tube 4, the protection tube 6 and the electric wire 8 are placed symmetrically with each other in the arrangement shown in FIG. 1. Especially, the electric wire 8 has its joint end abutted at the center of the flight tube 4. However, it is possible to shift them appropriately depending on the joining requirements, which may be considered to be within the designer's discretion. Further, the length of the flight tube 4 is joined to the electric wire 8 via the protective tube 6 over the entire length as a requirement for achieving good electrical connection, and the electric wire 8 is butted at the center of the flight tube 4. Considering this, assuming that the radius of the electric wire 8 is L and the length of the flight tube 4 is L, it is necessary that πrL ≧ πr ² ... 4). This means that the joint surface area on one side of the electric wire 8 must be equal to or larger than the cross-sectional area of the electric wire. However, with an aluminum wire,
An electric wire (ACS) with a steel wire for reinforcement arranged in the center
(R, etc.), the right side may be directed to the effective area as a conductor. Further, in the equation 4), the cross-sectional area is calculated on the assumption that the electric wire is not a stranded wire but an integral one, but if the effective cross-sectional area of the stranded wire is known, that value may be entered in the right side.

For example, an electric wire made of a stranded aluminum wire, which is called an ACSR160, is formed by twisting 30 aluminum wires having an outer diameter of 18.2 mm and a diameter of 2.6 mm around 7 steel wires having a diameter of 2.6 mm. The effective cross-sectional area of the electric wire is 159.3 mm ² , and when the required length L of the flight tube 4 is obtained by substituting this for the right side, it becomes 5.6 mm. In reality, it is not possible to accelerate the flight tube 4 having a length of less than 6 mm at a high speed with explosives and join it to the electric wire 8 through the protection tube 6, so that the flight tube 4 having a total length of about 40 mm or more, for example.
From the above, it can be seen from the above that if the flight tube 4 having a practically connectable length is used, the electrical connection requirement can be achieved at any length.

[0027]

The present invention is directed to a stranded wire of aluminum or its alloy, a stranded wire of copper or a copper alloy, a steel-core aluminum stranded wire for a transmission / distribution line or the like.
When joining electric wires such as (ACSR) by utilizing explosive pressure, metallurgically join not only to the part shown on the surface of the stranded wire but also to the inner layer part without relying on mechanical compression or caulking effect. In comparison with the conventional method of simply joining by mechanical compression, it requires less joining and has a longer length, thus enabling highly reliable joining with a small amount of explosive used. Since there is no space between them, it provides a method in which rainwater or corrosive gas does not enter and is not easily corroded.

[0028]

Example 1 The present invention will be described below with reference to examples. An industrial pure aluminum tube having an outer diameter of 32 mm, an inner diameter of 26 mm, and a length of 80 mm was prepared as the flight tube 4 in FIG. 1, and a vinyl chloride-based paint layer was spray-coated on the outer surface of the tube as a protective material 3. The explosive case 2 is formed by covering the entire circumference of the flight tube 4 and surrounding the periphery and the end with a drawing paper having a thickness of 0.2 mm to form the explosive case 1.
A black curlit explosive having a thickness of 10 mm was arranged as As a result, the dimensions of explosive 1 were 52 mm in outer diameter, 32 mm in inner diameter, and 80 mm in length. The amount of explosive was 119 g, and the loading density was 1.13 g / cm ³ . One end of the explosive wire 10 having a length of 300 mm has a diameter of 40 m at one end of the explosive 1.
The m-shaped ring was attached so that the ring was located approximately in the center of the thickness of the explosive 1.

The electric wire 8 to be joined is a power transmission line called ACSR 160, which has an outer diameter of 18.2 mm and a diameter of 2.6 m.
One of the two ends of 30 mm long aluminum wire having a length of 300 mm twisted around 7 steel wires of 2.6 mm in diameter has an outer diameter of 22 mm, an inner diameter of 19 mm, and a length of 1
A 20 mm pure aluminum tube for industrial use was inserted as a protective tube 6 from both ends thereof and abutted at the center. At that time, as a spacer 7, an aluminum wire having a diameter of 0.3 mm is inserted at a position 5 mm from the end of the electric wire 8 on the side where the protective tube 6 is inserted,
The wire 8 was wound once at a position of 5 mm so that the electric wire 8 was positioned substantially at the center of the protective tube 6. Both ends of the protective tube 6 and the portion of the electric wire 8 projecting from the protective tube 6 are fixed with an adhesive tape of vinyl chloride, and the flight tube 4 on which the explosive 1 or the like is mounted is centered in the length direction of the protective tube 6. 26 mm outside diameter and 22 inside diameter at both ends of the flight tube 4 so as to coincide with the center in the vertical direction.
mm, width 1mm, industrial pure aluminum tube spacer 5
Then, the protective tube 6 was attached so that the protective tube 6 was positioned concentrically with the flying tube 4, and both ends were fixed with an adhesive tape of vinyl chloride.

The thus-combined product is placed on sand with a thickness of about 300 mm and a diameter of about 2,000 mm, and the end of the string-like portion protruding from the annular portion of the detonating wire 10. Then, the electric detonator 9 was fixed with an adhesive tape made of paper, and the electric detonator 10 was energized from a remote position with a parallel electric wire coated with vinyl chloride to detonate the explosive 1. as a result,
Explosive 1 exploded at an explosive velocity of 2,030 m / sec.

Due to the explosion of the explosive 1, the flying tube 4 collided with the protective tube 6 at high speed, and was joined to the electric wire 8 while being joined to the protective tube 6. The joined body collected after the explosion was cut parallel to the axis with the longitudinal axis of the electric wire 8 as the center and the joint surface was inspected with an optical microscope. As a result, the flight tube 4 and the protective tube 6, the protective tube 6 and the electric wire 8 were observed. The surface of the wire and the stranded wires in the inner layer portion of the wire 8 were metallurgically bonded at the corrugated boundary.

A tensile strength test was conducted on the other bonded body produced in the same manner as described above using a tensile tester.
Is 7,110 kgf above the specified strength except for the joint
However, no fracture was observed at the joint and it was confirmed that the joint was achieved with sufficient strength.

In order to find out how much energy was applied at the time of joining, a combination obtained by removing the spacer 5, the protective tube 6, the spacer 7 and the electric wire 8 from the combination for joining was prepared and placed in the flight tube 4. , 6 pins which are electrical contact points for measuring the flight speed of the flight tube 4, the flight tube 4
It was installed by changing the distance from the inner surface of explosive, explosive 1 was exploded, and the contact time at each position of the pin was recorded on the oscilloscope. As a result, the velocity of the flight tube at a position 2 mm from the inner surface of the flight tube 4 where the flight tube 4 and the protection tube 6 collide is 66.
It was 8 m / sec. From the obtained flight speed, the amount of explosive 1 and the mass of the flight tube 4, the energy input to the joint is calculated by the equation 3), and 631 M per unit volume of the electric wire is calculated.
It was found that j / m ³ was input.

[0034]

Comparative Example 1 The same experiment as in Example 1 was conducted. However,
Other conditions were the same, and only the outer diameter of the explosive was set to 40 mm. As a result, the amount of explosive was 41 g and the loading density was 1.12 g /
cm ³ . As a result of detonating explosive 1, explosive 1 exploded at an explosion speed of 1,920 m / sec. When the cross section of the recovered bonded body was inspected in the same manner as in Example 1, the flight tube 4
The surface of the protective tube 6 and the surface of the protective tube 6 and the electric wire 8 were metallurgically joined, but the stranded wires in the inner layer of the electric wire 8 were not joined. When a tensile test was carried out, the aluminum wire on the surface was broken at one end of the protective tube, and the steel wire of the inner layer was pulled out to the joint end of the electric wire 8 without being broken.

When the flight speed of the flight tube 4 was measured in the same manner as in Example 1, the speed at the position where the flight tube 4 and the protection tube 6 collide was 522 m / sec. It was found that 385 Mj / m ³ had been injected. This value is less than the energy required to be input per unit volume of the electric wire, 400 Mj / m ³ , and it has been found that a larger amount of energy needs to be input in order to obtain good joining.

[0036]

Comparative Example 2 The same experiment as in Example 1 was conducted. However,
The flight tube 4 has an outer diameter of 28 mm, an inner diameter of 22 mm, and a length of 8
A 0 mm industrial pure aluminum tube was prepared, and a vinyl chloride-based paint layer was spray-coated as the protective material 3 on the outer surface thereof. As the explosive 1 covering the entire circumference of the flight tube 4, a black curlit explosive having a thickness of 10 mm was arranged, and the dimensions of the explosive 1 were an outer diameter of 48 mm, an inner diameter of 28 mm, and a length of 80 mm. Also, the amount of explosive is 108g, and the loading density is 1.13.
It became g / cm ³ . Explosive wire 10 was attached to explosive 1 in the same manner as in Example 1.

The difference from the first embodiment is that the flight tube 4 is provided with a spacer 5 having a width of 1 mm, the inner and outer diameters of which are adjusted so that the electric wire 8 is located at the concentric circle position of the flight tube 4 without the protection tube 6.
It was placed on both ends of and fixed. The combination thus obtained was placed on the sand, and the explosive 1 was detonated in the same manner as in Example 1. As a result, the flight tube 4 collides with the electric wire 8 and the flight tube 4
And the electric wire 8 were strongly metallurgically joined together, including the stranded wires of the inner layer of the electric wire 8, but the portion of the electric wire 8 protruding from the end of the flight tube 4 was a stranded wire of aluminum leaving the core of the steel wire. Were all disconnected. It is considered that this is because the aluminum wire was cut by the shearing stress generated at the end of the flying tube 4 because there was no protective tube 6.

Considering together with the results of Comparative Example 1, when the protective tube 6 is not provided, when trying to join even the stranded wires of the inner layer of the electric wire 8, the electric wire 8 protruding from both ends of the flying tube 4 is cut by shearing, It is obvious that the stranded wires in the inner layer of the electric wire 8 cannot be joined when trying to join them with a weak impact in order to prevent it.

[0039]

Example 2 A copper tube having an outer diameter of 32 mm, an inner diameter of 26 mm, and a length of 80 mm was prepared as the flight tube 4 in FIG. 1, and one layer of a vinyl chloride paint was spray-coated as a protective material 3 on the outer surface thereof. The explosive 1 has a thickness of 15 m by covering the entire circumference of the flight tube 4 and surrounding the end and the end with a drawing paper having a thickness of 0.2 mm.
m black curlit explosive was placed. As a result, the dimensions of the explosive 1 were 62 mm in outer diameter, 32 mm in inner diameter, and 80 mm in length. The amount of explosive is 200g and the loading density is 1.13.
It became g / cm ³ . One end of explosive 1 has a length of 30
A 0 mm detonator wire 10 having a ring with a diameter of 40 mm at one end was attached so that the ring was located at approximately the center of the thickness of the explosive 1.

As the electric wires 8 to be joined, one end of each of two wires of 300 mm in length obtained by twisting 37 hard copper power transmission wires having an outer diameter of 18.2 mm and φ2.6 mm of hard copper wires is used. A copper tube having a diameter of 22 mm, an inner diameter of 19 mm, and a length of 120 mm was inserted as both ends of the protective tube 6 and abutted at the center. At that time, the spacer 7 has a diameter of 0.3 mm.
5mm from the end where the copper wire of is inserted into the protective tube 6 of the electric wire 8.
And the position of 55 mm were wound once so that the electric wire 8 was positioned substantially at the center of the protective tube 6. Both ends of the protective tube 6 and the portion of the electric wire 8 projecting from the protective tube 6 are fixed with an adhesive tape of vinyl chloride, and the flight tube 4 on which the explosive 1 or the like is mounted is centered in the length direction of the protective tube 6. 26m outside diameter at both ends of the flight tube 4 so as to coincide with the center in the vertical direction.
A copper tube having a diameter of m, an inner diameter of 22 mm, and a width of 1 mm was attached as a spacer 5, the protective tube 6 was attached so as to be in a concentric position with the flying tube 4, and both ends were fixed with an adhesive tape of vinyl chloride.

The above-mentioned combination is placed on sand with a thickness of about 300 mm and a diameter of about 2,000 mm, and the end of the string-like portion protruding from the annular portion of the detonating wire 10. Then, the electric detonator 9 was fixed with an adhesive tape made of paper, and the electric detonator 9 was energized from a remote position by a parallel electric wire coated with vinyl chloride to detonate the explosive 1. As a result, explosive 1 exploded at an explosion speed of 2,270 m / sec.

Due to the explosion of the explosive 1, the flying tube 4 collided with the protective tube 6 at high speed, and was joined to the electric wire 8 while being joined to the protective tube 6. The joined body collected after the explosion was cut parallel to the axis with the longitudinal axis of the electric wire 8 as the center and the joint surface was inspected with an optical microscope. As a result, the flight tube 4 and the protective tube 6, the protective tube 6 and the electric wire 8 were observed. The surface of the wire and the stranded wires in the inner layer portion of the wire 8 were metallurgically bonded at the corrugated boundary.

A tensile strength test was conducted on the other bonded body produced in the same manner as described above using a tensile tester.
Is 7,930 kgf above the specified strength except for the joint
However, no fracture was observed at the joint and it was confirmed that the joint was achieved with sufficient strength.

In order to find out how much energy was applied at the time of joining, a combination obtained by removing the spacer 5, the protection tube 6, the spacer 7 and the electric wire 8 from the combination for joining was prepared and placed inside the flight tube 4. , 6 pins which are electrical contact points for measuring the flight speed of the flight tube 4, the flight tube 4
It was installed by changing the distance from the inner surface of explosive, explosive 1 was exploded, and the contact time at each position of the pin was recorded on the oscilloscope. As a result, the velocity of the flight tube at the position 2 mm from the inner surface of the flight tube 4 where the flight tube 4 and the protection tube 6 collide is 89.
It was 5 m / sec. From the obtained flight speed, the amount of explosive 1 and the mass of the flight tube 4, the energy input to the joint was calculated according to the formula 3), and it was 1,08 per unit volume of the electric wire.
It turns out that 7 Mj / m3 ^{is being} input. This value is the minimum value required to join stranded copper wire 900
It exceeds Mj / m ³ .

[0045]

Comparative Example 3 The experiment of Example 2 was repeated. However, only the outer diameter of the explosive 1 was changed to 52 mm. As a result, explosive 1
Had a thickness of 10 mm, a weight of 120 g and a loading density of 1.14 g / cm ³ . As a result of detonating explosive 1, explosive 1 exploded at an explosion speed of 2,060 m / sec.
When the cross section of the recovered bonded body was inspected in the same manner as in Example 1, the flight tube 4 and the protection tube 6 showed good metallurgical bonding, and the surfaces of the protection tube 6 and the electric wire 8 were partially metallurgically bonded. However, the stranded wires in the inner layer of the electric wire 8 were not joined.

When the flight speed of the flight tube 4 was measured in the same manner as in Example 1, the speed at the position where the flight tube 4 and the protection tube 6 collide was 351 m / sec, and the unit volume of the electric wire 8 was calculated from the equation 3). It was found that 576 Mj / m ³ was input per hit.
This value is less than the energy required to be applied per unit volume of the copper stranded wire, 900 Mj / m ³ , and it has been found that a larger amount of energy needs to be applied to obtain good bonding.

[0047]

Comparative Example 4 The experiment of Example 2 was repeated. However, the protection tube 6 is removed, and the flight tube 4 has an outer diameter of 30 mm and an inner diameter of 24
A copper tube having a length of 80 mm and a length of 80 mm was used. Also, the explosive 1 has an inner diameter of 0.2 mm so that the outer diameter is 60 mm and the inner diameter is 30 mm in contact with the flying tube 4 which is spray-coated with one layer of vinyl chloride paint as the protective material 3. The enclosure explosive 1 was loaded. As a result, 190 g of explosive 1 was loaded, and the loading density was 1.12 g / cm ³ . . The flying tube 4 was fixed without the protection tube 6 by placing spacers 5 having a width of 1 mm, the inner and outer diameters of which were adjusted so that the electric wires 8 were located at the concentric circles of the flying tube 4. When you explode explosive 1, explosive explodes at an explosive velocity of 2,080 m / sec,
The flight tube 4 and the electric wire 8 were joined, but the portion of the electric wire 8 that protruded from the end of the flight tube 4 was sheared by the collision of the flight tube 4 except for 5 to 7 stranded wires at each end of the flight tube. Was broken at.

When the joint portion was cut parallel to the longitudinal axis of the electric wire and inspected by an optical microscope, the flying tube 4 and the surface of the electric wire 8 and the twisted wires in the inner layer of the electric wire 8 were metallurgically bonded. It was In another experiment, the velocity of the flight tube 4 at the position where the flight tube 4 collides with the electric wire 8 was measured to be 454 m /
Seconds. From this speed, it was found from the equation 3) that 897 Mj / m ³ was input per unit volume of the electric wire 8. This value is almost equal to 900 Mj / m ^{3 which} is the energy required to be input per unit volume of the copper stranded wire, and can be said to be the lower limit of the condition for obtaining good joining. Was achieved, but the protection tube 6
Since the electric wire 8 is broken at both ends of the flight tube 4 due to the shear stress due to the lack of the above, it is shown that the existence of the protective tube 6 is an important requirement for achieving good joining together with the input energy amount.

[0049]

According to the present invention, in the case of joining electric wires using a metal pipe as a joint under explosive pressure, a protective material such as thick rubber is used to prevent damage to the metal pipe or electric wire due to explosive pressure. Since it covered the pipe and the electric wire, it was necessary to use a large amount of explosive, and between the metal pipe and the electric wire, the stranded wire of the inner layer of the electric wire was simply joined by mechanical compression or caulking, By removing the extremely thick protective material, incorporating a metal protection tube for protecting the electric wire, and constructing with appropriate input energy, a metal tube that is accelerated by explosive pressure and flies at high speed In the method of joining the wires by colliding with each other, metallurgically joins even the stranded wires in the inner layer of the wire to prevent rainwater and corrosive gas from entering the voids of the stranded wire joint and corroding the wire. Together with the metal pipe at both ends of the metal pipe Good joints are obtained conveniently by effectively preventing the electric wire at a shear stress at the time of colliding with the electric wire is broken, it is effective invention industrially.

Further, as compared with the explosive type electric wire joint which has been often used for electric wire connection, the amount of explosive is reduced and the auxiliary devices such as a protective tube are also reduced, which enables a compact design as a whole. . Further, since this kind of joint has a very large noise level at the time of explosion, it was mainly used for power transmission lines in mountainous areas far from the house. Even if a device is installed, a compact soundproofing device is sufficient, and it has become possible to clear environmental problems during construction even with transmission and distribution lines near urban areas that could not be applied until now, so the performance and workability are satisfactory. It is now possible to provide a pressure type wire connection device. In the specification of the present invention,
Although the method of joining two electric wires by butting, that is, the joining method using a linear sleeve has been described, the present invention is not limited to this and can be applied to one continuous electric wire. Those skilled in the art can easily think that it can be used as a repair sleeve used when the wire of the electric wire is damaged or cut.

[Brief description of drawings]

FIG. 1 is a diagram showing how to combine members for implementing the present invention.

FIG. 2 is a diagram showing a situation at the time of explosion of explosives when carrying out the present invention.

[Explanation of symbols]

1 Explosive 2 Explosive case 3 Protective material 4 Flight tube 5 Spacer between flight tube and protection tube 6 Protective tube (protective body) 7 Spacer between protection tube and electric wire 8 Electric wire 9 Detonator 10 Explosive wire 1 ' Explosive on the way DF Boundary of the process where explosive explodes into gas D Explosion direction and velocity Vp Velocity perpendicular to the direction of explosion of the flight tube 4 Vg Flying in the direction perpendicular to the direction of explosion of the protective tube 6 ' Speed Vh the speed at which the flight tube 4 ′ collides with the protection tube 6 ′ in the explosion direction Vu the speed at which the protection tube 6 ′ collides with the electric wire 8 ′ travels in the explosion direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Nishida 1-8-1, Hisamoto, Takatsu-ku, Kawasaki-shi, Kanagawa Asahi Electric Co., Ltd.

Claims (1)

[Claims] 1. An outer circumference of an electric wire to be joined is covered with a protective body (protective tube) made of a metal of the same system as that of the outer layer of the twisted wire and formed into a tubular curved surface in advance, and a protective body is provided on the outside thereof. This is a method in which a flight tube that is made of the same material and flies by the explosive pressure of explosives and collides with the protective body is placed, and the flight tube, the protective body, and the electric wire are integrally metallurgically joined, and the explosive surrounds the flight tube. The explosive is progressively advanced from one end of the explosive to the other end, and the explosion speed (explosion speed) is about 70
% Or less, and the flight speed of the flight tube in a direction perpendicular to the direction in which the explosion progresses is sufficient to join the stranded wires in the inner layer together.