JP2005276792A - Crimp style terminal for grounding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crimp style terminal for grounding not generating galvanic corrosion at jointing part of different kind of metals of a grounding cable and the crimp style terminal, which may as well not use any waterproof member. <P>SOLUTION: The terminal part for inserting and crimping an insulation covered grounding cable is composed of an almost cylindrical first terminal part having a first space part of which, inner diameter is almost same with the outer diameter of a covering body for insulation, and a second space part of which, inner diameter is almost same with the outer diameter of central conductor wire, and a second terminal part for connecting a grounding electrode extended from the first terminal part. The crimp style terminal for grounding is formed by using a metal having an ionization tendency smaller (noble) than that of central conductor wire, or a metal having a passivated surface covered by an oxide film formed by an oxidizer which is hardly corroded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a grounding crimping terminal used to connect a grounding electrode embedded in the ground and a grounding cable laid from a building or a lightning rod in the ground.

  Conventionally, when constructing a grounding device for a building or a lightning rod, a ground electrode is embedded in the ground, and a grounding cable is laid from the building or a lightning rod, etc., via a crimp terminal at a predetermined location inside the ground. Connected to the ground electrode.

  The grounding cable is mainly composed of a central conductor wire formed by twisting a copper conductor and an insulating covering made of a synthetic resin material, a rubber material, or the like that is coated on the outer periphery of the central conductor wire. On the other hand, as the ground electrode, a strip-like, rod-like or tubular electrode mainly made of a copper material is used, and is buried in the ground. The crimp terminal is generally made of a copper material, a galvanized iron material, or the like.

  Then, when connecting the ground cable to the ground electrode, the insulation coating is peeled off by a predetermined amount at one end of the ground cable to expose the center conductor wire, and a crimp terminal is attached to the exposed center conductor wire. The crimping terminal was attached with a caulking tool, and then the crimp terminal and the ground electrode were connected by various methods according to the shape of the ground electrode. For example, if the ground electrode is strip-shaped, the through hole drilled in the crimp terminal and the through hole drilled in the ground electrode are overlapped, and a bolt is inserted into this through hole and connected with a nut. It was.

  However, as described above, when a copper material is used for the ground electrode, corrosion may proceed early depending on the soil of the earth. In other words, the progress of the corrosion of the ground electrode was influenced by conditions such as soil resistivity, acidity, and salt content. In addition, a feedback current may be generated in the ground near the track circuit in the DC electrification section of the railway. For this reason, the corrosion of the ground electrode may proceed early.

  Therefore, in recent years, a titanium material or a stainless steel material is applied to the material of the ground electrode and the crimp terminal, and the ground electrode and the crimp terminal that are not easily corroded have been put into practical use.

About the grounding device comprised using the above ground electrodes etc., it describes in the following patent documents, for example.
Japanese Patent Publication No. 04-010288 No. 03-055259 No. 03-048849 Japanese Utility Model Publication No. 61-069357

  As described above, the ground electrode and the crimp terminal can be prevented from being corroded by constituting the ground electrode and the crimp terminal with a material that is unlikely to corrode such as titanium or stainless steel. Since the conductor wire is generally a copper material, the following adverse effects may occur.

  That is, in the crimp terminal that is the connection point between the ground cable and the ground electrode, the center conductor wire of the copper material of the ground cable and the crimp terminal such as titanium material or stainless steel material are connected. A joint portion between them will be formed. In this way, when the part where dissimilar metals are joined is placed in an electrolyte such as in the water, in the sea, in the soil, or in the atmosphere with moisture, the potential of the battery is lower due to the battery action due to the ionization tendency of the metal. There has been a problem of so-called galvanic corrosion that corrodes metals. If such corrosion is significant, the grounding cable is broken and the function as a grounding device is lost.

  As a means to cope with this galvanic corrosion, for example, a box-shaped waterproof member filled with a non-electrolytic gel may be wrapped around the connection portion to protect it. As the total cost increases, other improvement measures are required.

  The present invention is to review the structure of the conventional grounding device described above, in particular, the structure of the connection portion between the ground cable and the ground electrode, and solve the problems of the prior art. That is, an object of the present invention is to provide a grounding crimping terminal that does not cause galvanic corrosion at a joint portion between different metals of a grounding cable and a crimping terminal and that does not particularly require a waterproof member. And as a result, for the grounding cable, the central conductor wire uses a general insulation-coated lead wire made of copper, and for the grounding electrode and the crimping terminal, a material having high corrosion resistance such as titanium material or stainless steel material is applied to cause corrosion. The purpose is to make it possible to construct a grounding device that is resistant to damage.

In order to solve the above problems,
First,
In a grounding crimp terminal for electrically connecting a center conductor wire and an insulation-coated ground cable having an insulation coating on the outer periphery of the center conductor wire, and a ground electrode,
A terminal portion for inserting and crimping an insulation coated grounding cable, comprising a first space portion having an inner diameter substantially the same as the outer diameter of the insulation coating body, and an inner diameter substantially the same as the outer diameter of the central conductor wire A substantially cylindrical first terminal portion having a second space portion;
A second terminal portion for connecting a ground electrode extending from the first terminal portion, and
The material is a metal that has an ionization tendency smaller (noble) than the ionization tendency of the central conductor wire, or a metal that has a surface covered with an oxide film and is passivated and hardly corroded. It is a crimp terminal for grounding,
Secondly,
The grounding crimp terminal according to claim 1, wherein the grounding crimp terminal is formed of a titanium material or a stainless material, which is a non-corrosive metal whose surface is covered with an oxide film and is inactivated by an oxidizing agent. .

  Since the present invention is the crimp terminal for grounding as described above, the following effects can be obtained.

  The portion of the crimp terminal to which the ground cable is connected is arranged by inserting the central conductor of the ground cable into the second space of the first terminal portion of the crimp terminal, and the insulation covering of the ground cable is connected to the first terminal portion of the crimp terminal. The first terminal portion of the crimp terminal, the center conductor wire of the grounding cable, and the insulation covering are surely provided because the entire first terminal portion is pressed with a caulking tool. Crimped to.

  As a result, even if the center conductor wire of the ground cable and the crimp terminal are made of different metals, the junction between the different metals is not placed in the electrolyte (underground), and thus prevents galvanic corrosion. be able to. In the case where a titanium material is used for the ground electrode, since the ground electrode and the crimp terminal are made of the same kind of metal by using a titanium material as the crimp terminal, the galvanic corrosion does not occur.

  As a result, the ground cable is corroded by using a general insulation-coated ground cable whose center conductor wire is a copper material, and the ground electrode and the crimp terminal having a high corrosion resistance such as titanium or stainless steel. It is possible to construct a grounding device that is resistant to damage and provide a reliable grounding device in which the grounding cable is not broken.

  Further, since it is not necessary to separately prepare a waterproof member such as a member containing a non-electrolyte gel, the cost of the waterproof member is not required, and the waterproof work process is not required, so that the total cost can be suppressed. .

  The best mode for carrying out the present invention will be described below. However, the present invention is not limited to the following modes as long as the gist of the present invention is not exceeded.

  First, the grounding crimp terminal according to the present invention will be described with reference to FIGS. X is a crimp terminal for grounding, and is formed of a first terminal portion X1 for inserting and crimping an insulation-coated ground cable K, and a second terminal portion X2 for connecting a ground electrode. .

  The surface of the grounding crimp terminal X is not covered with an oxide film by a metal having an ionization tendency smaller (noble) than the central conductor wire kb made of copper of the insulation-coated ground cable K or an oxidizing agent. For example, when the central conductor line kb is a copper material, it is a metal having an ionization tendency smaller (noble) than the ionization tendency of the central conductor line kb. Lead (chemical symbol: Pb) or the like can be applied. In addition, a titanium (chemical symbol: Ti) material, a stainless steel (material symbol: SUS) material, or the like, which is covered with an oxide film and is inactivated by an oxidizing agent and hardly corroded, can be used. Titanium is a metal that has a higher ionization tendency (base) than copper in terms of elemental elements, but immediately reacts in the air in the natural environment to form an oxide film, passivated, and extremely corrosive. It becomes a difficult metal. Further, the grounding crimp terminal X to which the titanium material is applied is particularly suitable for connecting the insulation coated grounding cable K made of the center conductor wire kb of the copper material and the strip-shaped grounding electrode S made of the titanium material described later. It will be a thing.

  The first terminal portion X1 of the grounding crimping terminal X is formed in a substantially cylindrical shape, and includes a cylindrical cable crimping portion 3 and a disk-shaped connecting portion 7. Further, the internal space of the cable crimping portion 3 is outside the first space portion 5 having an inner diameter substantially the same as the outer diameter of the insulation coating body ka of the insulation-coated ground cable K and the center conductor wire kb of the insulation-coated ground cable K. A second space 6 having an inner diameter substantially the same as the diameter is formed.

  On the other hand, the second terminal portion X2 of the grounding crimping terminal X is formed in a substantially plate shape, and has a plate-like electrode connecting portion 1, a bowl-like connecting portion 2, and a disc-like connecting portion 8. . In addition, a through hole 4 is formed near the center of the electrode connecting portion 1 to be used when connecting to a ground electrode S described later. And the 1st terminal part X1 and the 2nd terminal part X2 are joined by the disk-shaped connection parts 7 and 8, and the crimp terminal X for grounding is formed.

  Next, a grounding device constructed by connecting the insulation-coated grounding cable K and the grounding electrode S using the grounding crimp terminal X of the present invention described above will be described with reference to FIGS.

  K is an insulation-coated ground cable, and is formed of a central conductor wire made of a copper material and an insulation coating made of a synthetic resin material, a rubber material, or the like. Then, one end of the insulation-coated grounding cable K has the insulation covering peeled off to expose the center conductor wire kb, and is inserted into the internal space of the cable crimping part 3 of the grounding crimping terminal X. The cable crimping portion 3 is pressurized by the hexagonal caulking tool that is not, and the insulation-coated grounding cable K and the grounding crimping terminal X are crimped and connected.

  As a result, the second space 6 and the central conductor line kb and the first space 5 and the insulation covering body ka are firmly attached, so that the waterproofing at the boundary between the insulation covering body ka and the cable crimping portion 3 is achieved. Sex is secured. Therefore, the dissimilar metal joint portion between the cable crimping portion 3 and the center conductor wire kb does not come into contact with the soil as the electrolyte, and galvanic corrosion does not occur. In the drawing, the state in which the ratio in the length direction of the first space portion 5 and the second space portion 6 is about 1: 2 is described, but the present invention is not limited to this and is waterproof. Can be appropriately changed within a range satisfying the above.

  S is a belt-like ground electrode made of the same titanium material as that of the grounding crimp terminal X, for example. This strip-shaped ground electrode S has a structure that can be connected and connected in a shape of, for example, a width of 5 cm, a thickness of 2 mm, and a length of about 1.5 m, and can be formed to an appropriate length if necessary. is there. A through hole sa is formed at one end of the ground electrode S, and overlaps with the through hole 4 of the grounding crimp terminal X, and a bolt B is inserted into these through holes to the nut N. Are screwed together. In addition, since the ground electrode S and the grounding crimp terminal X are joints of the same kind of metal, galvanic corrosion does not occur.

  Next, another grounding crimp terminal of the present invention will be described with reference to FIGS. Y is a crimp terminal for grounding, and is formed of a first terminal portion Y1 for crimping and connecting the insulation-grounded ground cable K, and a second terminal portion Y2 for connecting the ground electrode. .

  The surface of the grounding crimp terminal Y is not covered with an oxide film by a metal having an ionization tendency smaller (noble) than the central conductor wire kb made of a copper material of the insulation-coated ground cable K or an oxidizing agent. For example, when the central conductor line kb is a copper material, it is a metal having an ionization tendency smaller (noble) than the ionization tendency of the central conductor line kb. Lead (chemical symbol: Pb) or the like can be applied. In addition, a titanium (chemical symbol: Ti) material, a stainless steel (material symbol: SUS) material, or the like, which is covered with an oxide film and is inactivated by an oxidizing agent and hardly corroded, can be used. Titanium is a metal that has a higher ionization tendency (base) than copper in terms of elemental elements, but immediately reacts in the air in the natural environment to form an oxide film, passivated, and extremely corrosive. It becomes a difficult metal. Further, the grounding crimp terminal Y to which the titanium material is applied is particularly suitable for connecting the insulation coated grounding cable K made of the central conductor wire kb of the copper material and the tubular grounding electrode S1 made of the titanium material described later. It will be a thing.

  The first terminal portion Y1 of the grounding crimping terminal Y is formed in a substantially cylindrical shape, and has a cylindrical cable crimping portion 11. In addition, the inner space of the cable crimping portion 11 is outside the first space portion 14 having an inner diameter substantially the same as the outer diameter of the insulation covering body ka of the insulation-coated ground cable K, and the center conductor line ka of the insulation-coated ground cable K. A second space 15 having an inner diameter substantially the same as the diameter is formed.

  On the other hand, the second terminal portion Y2 of the grounding crimping terminal Y is formed in a substantially cylindrical shape having an outer peripheral radius larger than the outer peripheral radius of the first terminal portion Y1, and a screw having a thread threaded on the outer periphery. A landing part 13 is provided. In addition, a disk-shaped connecting portion 12 is provided between the first terminal portion Y1 and the second terminal portion Y2. In this way, the grounding crimp terminal Y is formed.

  Next, a grounding device constructed by connecting the insulation-coated grounding cable K and the grounding electrode S1 using the grounding crimp terminal Y of the present invention described above will be described with reference to FIGS.

  K is an insulation coated grounding cable, and is formed of a central conductor wire made of a copper material and an insulation coating made of a synthetic resin material, a rubber material or the like. The insulation coating body is peeled off at one end of the insulation coated ground cable K to expose the central conductor wire kb, and is inserted into the internal space of the cable crimping portion 11 of the ground crimp terminal Y. The cable crimping portion 11 is pressurized by the hexagonal caulking tool that is not, and the insulation-coated grounding cable K and the grounding crimping terminal Y are crimped and connected.

  As a result, the second space portion 15 and the central conductor line kb and the first space portion 14 and the insulation coating body ka are firmly attached, so that the waterproofing at the boundary between the insulation coating body ka and the cable crimping portion 11 is achieved. Sex is secured. Therefore, the dissimilar metal joint portion between the cable crimping portion 11 and the center conductor wire kb does not come into contact with the soil as the electrolyte, and galvanic corrosion does not occur. In the drawing, although the ratio of the length direction of the first space portion 14 and the second space portion 15 is about 1: 2, it is not limited to this and is waterproof. Can be appropriately changed within a range satisfying the above.

  S1 is a tubular ground electrode made of, for example, the same titanium material as the grounding crimp terminal Y. The tubular ground electrode S1 has, for example, a hollow pipe shape with an outer diameter of 3 cm, a wall thickness of 2 mm, and a length of about 1.5 m. One end of the tubular ground electrode S1 is similar to the second terminal portion Y2 of the ground terminal member Y. Has a cylindrical threaded portion s1a in which a thread is threaded. Also, the other end is a pan-like screwed portion having a thread threaded on the inner periphery so that the screwed portion s1a of the other ground electrode S1 or the second terminal portion Y2 of the grounding crimping member Y can be screwed together. s1b.

  The grounding crimp terminal Y and the ground electrode S1 are connected so that the screwing portion 13 of the second terminal portion Y2 of the grounding crimping terminal Y is screwed into the screwing portion S1b of the ground electrode S1. The ground electrode S1, like the ground electrode S, can be connected and connected, and can be formed to an appropriate length as required. Note that since the ground electrode S1 and the grounding crimp terminal Y are joints of the same metal, galvanic corrosion does not occur.

  Finally, the experimental results regarding corrosion when a grounding device is constructed using the grounding crimp terminal of the present invention will be described.

  A grounding device is constructed by connecting an insulation-coated grounding cable K having a central conductor wire made of copper and a strip-shaped grounding electrode S made of titanium to the crimping terminal X for grounding of the present invention made of titanium. In the meantime, it was immersed in 3% concentration salt water as an electrolyte. However, no corrosion was observed in the insulation coated grounding cable K, the grounding crimping terminal X, and the grounding electrode S. In addition, the cable crimping part 3 where the insulation-coated ground cable K and the grounding crimping terminal X are connected is cut with an electric cutter, and the junction boundary between the center conductor wire kb and the cable crimping part 3 is confirmed. No galvanic corrosion was observed.

  Further, a grounding device is constructed by connecting an insulation-coated grounding cable K having a central conductor wire made of a copper material and a strip-shaped grounding electrode S1 made of a titanium material to the crimping terminal Y for grounding of the present invention made of titanium material, Although it was immersed in 3% concentration salt water as an electrolyte for 6 months, no corrosion was observed in the appearance of the insulation coated grounding cable K, the grounding crimp terminal Y, and the grounding electrode S1. Also, the cable crimping part 11 where the insulation-coated ground cable K and the grounding crimping terminal Y are connected is cut with an electric cutter, and the junction boundary between the center conductor wire kb and the cable crimping part 11 is confirmed. No galvanic corrosion was observed.

  FIG. 1 is a left side view of a grounding crimp terminal of the present invention.   FIG. 2 is a front view of the grounding crimp terminal of the present invention.   FIG. 3 is a right side view of the grounding crimp terminal of the present invention.   FIG. 4 is a top view of the grounding crimp terminal of the present invention.   FIG. 5 is a front view showing a partial cross section of the grounding crimp terminal of the present invention.   FIG. 6 is a partially enlarged front view of the grounding device in which the grounding cable and the ground electrode are connected using the grounding crimping terminal of the present invention, in which the vicinity of the grounding crimping terminal is enlarged.   FIG. 7 is a partially enlarged top view of the grounding device in which the grounding cable and the grounding electrode are connected using the grounding crimping terminal of the present invention, in which the vicinity of the grounding crimping terminal is enlarged.   FIG. 8 relates to a grounding device in which a grounding cable and a grounding electrode are connected by using the grounding crimping terminal of the present invention, and shows a part of the grounding crimping terminal in a partially enlarged view while showing the vicinity of the grounding crimping terminal. It is an enlarged front view.   FIG. 9 is a front view of another grounding crimp terminal of the present invention.   FIG. 10 is a top view of another grounding crimp terminal of the present invention.   FIG. 11 is a bottom view of another grounding crimp terminal of the present invention.   FIG. 12 is a front view showing a partial cross section of another grounding crimp terminal of the present invention.   FIG. 13 is a partially enlarged front view of the grounding device in which the grounding cable and the grounding electrode are connected using another grounding crimping terminal of the present invention, in which the vicinity of the grounding crimping terminal is enlarged.   FIG. 14 relates to a grounding device in which a grounding cable and a grounding electrode are connected using another grounding crimping terminal of the present invention, and an enlarged view of the vicinity of the grounding crimping terminal and a partial cross section of the grounding crimping terminal are represented. FIG.

Explanation of symbols

X ... Grounding crimp terminal X1 ... First terminal part X2 ... Second terminal part 1 ... Electrode connection part 2 ... Connection part 3 ... Cable crimping part 4 ... Through hole 5 ... First space part 6 ... 2nd space part 7 ... Connection part 8 ... Connection part Y ... Crimp terminal for grounding Y1 ... 1st terminal part Y2 ... 2nd terminal part 11 ... Cable crimping part 12 ... Connection part 13 ...... Screwed portion 14 ...... First space portion 15 ...... Second space portion K ...... Insulation coated ground cable S, S1 ...... Ground electrode sa ...... Through hole s1a ...... Screwed portion s1b ...... Screwed portion B ... Bolt N ... Nut

Claims (2)

In a grounding crimp terminal for electrically connecting a center conductor wire and an insulation-coated ground cable having an insulation coating on the outer periphery of the center conductor wire, and a ground electrode,
A terminal portion for inserting and crimping an insulation coated grounding cable, comprising a first space portion having an inner diameter substantially the same as the outer diameter of the insulation coating body, and an inner diameter substantially the same as the outer diameter of the central conductor wire A substantially cylindrical first terminal portion having a second space portion;
A second terminal portion for connecting a ground electrode extending from the first terminal portion, and
The material is a metal that has an ionization tendency smaller (noble) than the ionization tendency of the central conductor wire, or a metal that has a surface covered with an oxide film and is passivated and hardly corroded. Crimp terminal for grounding.   The grounding crimp terminal according to claim 1, wherein the grounding crimp terminal is formed of a titanium material or a stainless material, which is a non-corrosive metal whose surface is covered with an oxide film and is inactivated by an oxidizing agent.

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