WO2009069941A2

WO2009069941A2 - Pipeline detection cable and connection method of pipeline detection cables

Info

Publication number: WO2009069941A2
Application number: PCT/KR2008/006976
Authority: WO
Inventors: Sang Woon Yoon
Original assignee: Sang Woon Yoon
Priority date: 2007-11-26
Filing date: 2008-11-26
Publication date: 2009-06-04
Also published as: WO2009069941A3; KR100838634B1

Abstract

Disclosed therein is a pipeline detection cable attached to a rigid plastic conduit buried in the ground in order to detect a route of the buried rigid plastic conduits with electromagnetic waves, including two band-shaped sheet conductors vertically piled up inside a synthetic resin covering in such a way that contact surfaces thereof are separable from each other.

Description

PIPELINE DETECTION CABLE AND CONNECTION METHOD OF PIPELINE DETECTION CABLES

Technical Field

[1] The present invention relates to a pipeline detection cable, and more particularly, to a pipeline detection cable attached to a rigid plastic conduit buried in the ground in order to detect a route of the buried rigid plastic conduits with electromagnetic waves. Background Art

[2] In general, it is difficult to recognize a route of a pipeline buried in the ground or concrete, such as a water supply pipeline, a sewerage pipeline, a gas pipeline, a boiler pipeline, and so on, with naked eyes after the pipeline is buried in the ground. However, if there is a need to carry out pipeline repairing work, pipeline exchanging work, excavation work near the pipelines, and so on, it is necessary to correctly know a buried location of the pipeline to thereby perform the excavation work without any damage to the pipeline and carry out the pipeline repairing work or the pipeline exchanging work rapidly. While the pipeline is made of cast iron, steel, copper or the like, recently, a rigid plastic conduit, which is reinforced in strength and shock resistance, is greatly used due to its non-corrosiveness. In case of a metal pipeline, a buried route of the metal pipeline can be detected to some extent by using a metal detector or sensing electromagnetic waves generated when an electric current is applied to the pipeline. However, in case of the rigid plastic conduit, it is impossible to detect the buried route of the rigid plastic conduit using the metal detector or the electromagnetic detector since it is a nonconductor.

[3]

[4] Accordingly, when the rigid plastic conduit is buried in the ground, a pipeline detection cable having a conductor is attached to the rigid plastic conduit, and the pipeline detection cables are electrically connected with each other when the rigid plastic conduits are connected with each other. However, it is not easy to electrically connect the pipeline detection cables with each other on the spot where the rigid plastic conduits are buried.

[5]

[6] A rigid plastic pipe (hereinafter, called a rigid plastic conduit ) is standardized and produced in a predetermined length. In case where the pipeline detection cables are attached to the rigid plastic conduits, since the pipeline detection cables must be separated from one another into the standardized length of the rigid plastic conduits, the adjacent pipeline detection cables, which are separated into the length of each of the rigid plastic conduits, are must be electrically connected with each other especially when a worker detects a pipeline using an electromagnetic wave detector. In this instance, in case where the pipeline detection cables are connected with each other in a general cable connection method including the steps of partially removing front coverings of the pipeline detection cables, which will be connected with each other, twisting electric conductors with each other, and adhering an insulating tape to the twisted electric conductors, it has a problem in that the connected portions of the pipeline detection cables are easily separated from each other during a process that the rigid plastic conduits are buried in the ground after soil or concrete is poured. Then, there is no meaning in constructing the pipeline detection cables. Particularly, in case where pipeline detection cables of a metal band shape are connected with each other in the above-mentioned method, it has several problems in that the connection work is very difficult and they are easily separated from each other after the connection.

[7]

[8] Accordingly, in general, during a manufacturing process of the rigid plastic conduits, pipeline detection cables are mounted in a method including the steps of attaching a pipeline detection cable, which is nearly similar to the length of each of the rigid plastic conduits, to each of the rigid plastic conduits, combining connectors or plugs, which are previously produced, to both ends of the pipeline detection cable, carrying the rigid plastic conduits, to which the pipeline detection cables are respectively attached, to the burying field of the rigid plastic conduits, and connecting the adjacent pipeline detection cables with each other in the field. However, since arrangement and required length of the rigid plastic conduits are different every burying field of the rigid plastic conduits, it is impossible to perform construction using only the rigid plastic conduits of a predetermined length, and hence, the rigid plastic conduits are cut to a necessary length according to situations of the burying field. In this instance, since it is difficult to connect the pipeline detection cables without the connectors or plugs due to the above-mentioned reason and it takes much time and requires additional harness equipments, such as terminal crimping tools, to separate the connectors or plugs from the pipeline detection cables in the field, remove a part of the pipeline detection cable according to the length of the rigid plastic conduit and reconnect the connectors or plugs to the pipeline detection cable, the pipeline detection cables are left as they are and only the rigid plastic conduits are cut. Accordingly, after the rigid plastic conduits are buried in the ground, a surplus pipeline detection cable remains around the connected portion, and hence, the pipeline detection cables are separated from the rigid plastic conduits at a predetermined distance every connected portion of the pipeline detection cables. It causes an unnecessary waste of the pipeline detection cables and a disconnection of the connected portions of the pipeline detection cables. That is, since a part of the pipeline detection cables and the connectors are separated from the rigid plastic conduits, it causes a separation of the connectors when soil or concrete is poured to bury the rigid plastic conduits in the ground. Moreover, if the pipeline detection cables are separated from the rigid plastic conduits, it is difficult to correctly detect the pipeline and it is easy to damage the pipeline by an excavator when an excavation work is performed to repair the rigid plastic conduits.

[9]

[10] To connect the pipeline detection cables using the connectors or plugs has the above- mentioned problems and a problem in that it is very difficult to seal connection terminals of the connectors or plugs.

[H]

[12] Accordingly, preferable pipeline detection cables must have a structure that the worker can easily connect the adjacent pipeline detection cables with each other only by a simple manipulation after they are cut in the field according to the length of the rigid plastic conduits, which will be buried in the ground, and attached to the rigid plastic conduits, that they are not damaged by pouring of soil or concrete and by the excavator after the connection thereof, and that they can prevent penetration of moisture or foreign matters into the electric conductors.

[13]

Disclosure of Invention

Technical Problem

[14] Accordingly, the present invention has been made in an effort to solve the above- mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a pipeline detection cable and a connection method of the pipeline detection cable, which can allow a worker to easily connect the adjacent pipeline detection cables with each other only by a simple manipulation after cutting them in the burying field of the rigid plastic conduits according to the length of the rigid plastic conduits and attaching them to the rigid plastic conduits.

[15]

[16] It is another object of the present invention to provide a pipeline detection cable and a connection method of the pipeline detection cable, which are not easily separated from each other once they are connected even when soil or concrete is poured to bury the rigid plastic conduits in the ground.

[17]

[18] It is a further object of the present invention to provide a pipeline detection cable and a connection method of the pipeline detection cable, which can surely prevent penetration of moisture into the pipeline detection cables after burying. [19]

Technical Solution

[20] To achieve the above objects, the present invention provides a pipeline detection cable comprising two band-shaped sheet conductors vertically piled up inside a synthetic resin covering in such a way that contact surfaces thereof are separable from each other.

[21]

[22] When the pipeline detection cables are connected with each other, the contact surfaces of the piled-up sheet conductors are separated from each other, and then, a electric conducting bar is inserted between the sheet conductors.

[23]

[24] The two sheet conductors are disposed inside the synthetic resin covering in such a way as to be separated from each other. In order to connect the pipeline detection cables with each other, cut the pipeline detection cables, which will be connected with each other, according to the length of the rigid plastic conduits, separate the contact surfaces of the sheet conductors from each other after lying ends of the pipeline detection cables adjacent to each other, and then, partly insert the electric conducting bar between the contact surfaces of the two pipeline detection cables with the hand. After the insertion of the electric conducting bar, the outside of the connected portion of the pipeline detection cables is sealed with a thermal contraction tube. As described above, when the pipeline detection cables according to the present invention are used, the two pipeline detection cables can be rapidly, securely, electrically and physically connected with each other by a simple manipulation and provide watertightness and sealability.

[25]

[26] When a release sheet, which is wider than the sheet conductors, is mounted on the back of the sheet conductors, a hollow is formed around the piled-up sheet conductors only by a little covering compression, whereby the electric conducting bar can be more easily inserted between the sheet conductors.

[27]

[28] Also, when a release film wraps the entire piled-up sheet conductors, a hollow is formed around the piled-up sheet conductors, whereby the electric conducting bar can be more easily inserted between the sheet conductors.

[29]

[30] A method of connecting the pipeline detection cables includes the steps of: preparing an electric conducting bar, which can be inserted into gaps formed between contact surfaces of sheet conductors of the pipeline detection cables; lying the pipeline detection cables, which will be connected with each other, adjacent to each other; partly inserting the electric conducting bar into the gaps formed between the contact surfaces of the sheet conductors of the two adjacent pipeline detection cables; and sealing the outside of the connected portion of the pipeline detection cables using a thermal contraction tube.

[31]

[32] The electric conducting bar may be a flat type conducting bar or a bent type conducting bar having terminals of a round-shaped front end form formed every bent portion in such a way as to repeatedly bend the central portion of a linear conductor.

[33]

Advantageous Effects

[34] According to the present invention, the pipeline detection cables can allow the worker to easily connect the adjacent pipeline detection cables with each other only by a simple manipulation after cutting the pipeline detection cables in the burying field of the rigid plastic conduits according to the length of the rigid plastic conduits and attaching them to the surfaces of the rigid plastic conduits, are not easily separated from each other even when soil or concrete is poured to bury the rigid plastic conduits in the ground since the pipeline detection cables are in close contact with the rigid plastic conduits once they are connected, and can surely prevent penetration of moisture, foreign matters, and so on into the pipeline detection cables after burying.

[35]

Brief Description of the Drawings

[36] FIG. 1 is an exploded perspective view showing pipeline detection cables and double-sided adhesive tapes mounted on the back of the pipeline detection cables according to a first preferred embodiment of the present invention.

[37] FIG. 2 is an exploded perspective view showing an electric conducting bar and a thermal contraction tube used for a simply electrical connection of the pipeline detection cables of FIG. 1.

[38] FIGS. 3 and 4 are perspective views showing a method of previously assembling the electric conducting bar and the thermal contraction tube before they are used for connection of the pipeline detection cables.

[39] FIGS. 5 to 8 are working flow charts showing a method of electrically connecting the pipeline detection cables of FIG. 1 using the electric conducting bar and the thermal contraction tube of FIG. 4.

[40] FIGS. 9 and 10 are application diagrams showing a state where the pipeline detection cables are electrically connected with each other using the electric conducting bar and the thermal contraction tube of FIG. 4 after the pipeline detection cables of FIG. 1 are attached on outer faces of rigid plastic conduits.

[41] FIG. 11 is a perspective view, in a partial section, of a pipeline detection cable according to a second preferred embodiment of the present invention.

[42] FIG. 12 is an application diagram showing a method of connecting the pipeline detection cables of FIG. 11.

[43] FIG. 13 is a perspective view showing piled-up sheet conductors and a release film wrapping the sheet conductors used in a pipeline detection cable according to a third preferred embodiment of the present invention.

[44] FIG. 14 is a partially sectional perspective view of the pipeline detection cable according to the third preferred embodiment.

[45] FIG. 15 is an application diagram showing a method of connecting the pipeline detection cables of FIG. 14.

[46] FIG. 16 is a perspective view of a bent- type electric conducting bar used for electrically connecting the pipeline detection cables according to the present invention.

[47] FIG. 17 is a perspective view of the bent-type electric conducting bar having a handgrip formed at the center thereof.

[48] <Explanation of essential reference numerals in drawings>

[49] la,lb,lc,ld: electric conducting bar 3: notch

[50] 5: stop jaw 7: thermal contraction tube

[51] 9: contractably joined portion

[52] 11: hand-grip

[53] 13: covering 15: groove

[54] 17a, 17b: sheet conductor 19: gap

[55] 21: double-sided adhesive tape

[56] 23a,23b: rigid plastic conduit

[57] 25: release sheet 27: release film

[58] PLD1,PLD2,PLD3: pipe line detection cable

[59]

Best Mode for Carrying Out the Invention

[60] Reference will be now made in detail to the preferred embodiments of the present invention with reference to the attached drawings.

[61]

[62] <First Embodiment

[63] Referring to FIG. 1, a pipeline detection cable (PLDl) according to a first preferred embodiment of the present invention is manufactured in such a way that a synthetic resin covering is formed around two separably piled-up sheet conductors by extrusion. Due to an expansion and contraction force of the synthetic resin covering and smoothness of the surfaces of the sheet conductors, it is very easy to insert an electric conducting bar between the sheet conductors.

[64]

[65] It is preferable that the synthetic resin covering 13 is formed in a band shape so as to be easily adhered on the outer surfaces of cylindrical rigid plastic conduits 23a and 23b. Furthermore, it is preferable that a double-sided adhesive tape 21 is previously adhered on the lower surface of the synthetic resin covering 13 in order to rapidly attach the pipeline detection cables (PLDl) to the rigid plastic conduits in the burying field of the rigid plastic conduits 23 a and 23b in the ground.

[66]

[67] The sheet conductors may be thin band-shaped steel sheet conductors, copper sheet conductors, aluminum sheet conductors, or copper alloy sheet conductors. The piled- up sheet conductors 17a and 17b have a merit in that they can send an electric current even though one of the conductors is in contact with the electric conducting bar Ia since they are two band-shaped sheet conductors. In this instance, the piled-up sheets may be sheets of the same quality or sheets of different qualities. That is, one steel sheet and one copper sheet may be piled up or one copper sheet and one copper alloy sheet may be piled up. In case where a tensile strength and an electric conductivity are needed simultaneously, the pipeline detection cable can obtain the satisfactory tensile strength and electric conductivity when the sheets of the different qualities are piled up. Moreover, in the drawings, it is illustrated that the piled-up sheet conductors 17a and 17b are accommodated in one covering 13 in one row as an example, but if necessary, it is possible that the piled-up sheet conductors 17a and 17b are accommodated in one widened covering 13 in at least two rows in parallel (See FIGS. 11 to 15).

[68]

[69] The covering 13 is a thermoplastic covering having the expansion and contraction force, such as PC, urethane, PE, and so on. Since the covering 13 has the expansion and contraction force, the electric conducting bar Ia can be easily inserted into a gap 19 formed between contact surfaces of the piled-up sheet conductors 17a and 17b. The double-sided adhesive tape 21 is formed in such a way that release sheets are adhered on both sides of an adhesive film, and hence, the upper release sheet is removed when the double- sided adhesive tape 21 is adhered on the lower surface of the covering and the lower release sheet is removed when the pipeline detection cables (PLDl) according to the present invention are attached to the rigid plastic conduits 23a and 23b.

[70]

[71] Referring to FIGS. 1 to 9, it is preferable that inwardly formed grooves 15 are formed on an upper face and/or a lower face of the band-shaped covering 13 along a length direction of the covering to prevent an edge of the covering 13 is separated due to elasticity when the pipeline detection cables (PLDl) are attached to the outer faces of the rigid plastic conduits 23a and 23b. The grooves 15 can be very usefully used also when the covering of a front end portion of the pipeline detection cable to be connected is partially removed. A general electric wire stripper has a structure that it is difficult to simultaneously remove the band-shaped covering, but in case where the grooves 15 are formed, the stripper can easily remove the covering around the piled-up sheet conductors 17a and 17b remaining after the covering is cut to a wanted length along the grooves 15 and both side wings are first removed.

[72]

[73] If the electric conducting bar Ia and a thermal contraction tube 7 shown in FIGS. 2 and 4 are used, the pipeline detection cables can be very rapidly and easily connected with each other in the connection field of the rigid plastic conduits 23 a and 23b and it provides perfect watertightness and sealability. Referring to FIG. 2, both ends of the electric conducting bar Ia have a structure that they can be inserted into the gaps 19 (See FIG. 6) formed between the piled-up sheet conductors 17a and 17b of the pipeline detection cables, and the electric conducting bar Ia includes a stop jaw 5 formed at the center thereof to adjust an insertion length. The thermal contraction tube 7 is a tube of a known poly olefin group. When heat is applied, the thermal contraction tube 7 is contracted and hardened. When the thermal contraction tube 7, in which hot melt is coated on an inner face thereof, is used, it can provide more improved watertightness and sealability.

[74]

[75] As shown in FIG. 2, if notches 3 are formed on the surface of the electric conducting bar Ia, it prevents that the electric conducting bar Ia is separated from the gap since jaws formed between the notches 3 are caught to the covering after the electric conducting bar Ia is inserted into the gaps 19 formed between the piled-up sheet conductors 17a and 17b. It would be appreciated that those skilled can change the notches 3 into various forms.

[76]

[77] The electric conducting bar Ia and the thermal contraction tube 7 can be used for the electric connection of the pipeline detection cables after they are supplied to the burying field of the rigid plastic conduits in a separated state, but for rapidity and simplification, it is preferable to supply them to the burying field of the rigid plastic conduits in a previously assembled state as shown in FIGS. 3 and 4 in the connection work of the pipeline detection cables. As shown in FIGS. 3 and 4, in order to assemble the electric conducting bar Ia and the thermal contraction tube 7, the electric conducting bar Ia is put into the thermal contraction tube 7 and heat is applied to the central portion of the thermal contraction tube 7, so that the central portion is contracted around the stop jaw 5 of the electric conducting bar Ia. The reference numeral 9 in FIG. 4 designates a contractably joined portion formed through the above method.

[78]

[79] Hereinafter, referring to FIGS. 5 to 10, a method of rapidly and simply connecting the pipeline detection cables of the present invention in the burying field of the rigid plastic conduits will be described.

[80]

[81] First, as shown in FIG. 5, remove the covering 21 of the front end of the pipeline detection cable (PLDl) as long as a predetermined length to thereby expose parts of the piled-up sheet conductors 17a and 17b. In this state, insert the electric conducting bar Ia into the gaps 19 formed between the piled-up sheet conductors 17a and 17b of two pipeline detection cables, or upwardly and downwardly bend the exposed and piled-up sheet conductors 17a and 17b and closely contact the bent portions of the sheet conductors with the upper and lower faces of the covering as shown in FIG. 6. It is necessary to easily insert the electric conducting bar Ia into the gap 19 between the piled-up sheet conductors 17a and 17b and to strengthen the tensile force of the connected portion after contraction of the thermal contraction tube 7 to thereby prevent a separation of the connected pipeline detection cables (PLDl) from each other. Next, as shown in FIGS. 7 and 8, insert both sides of the electric conducting bar Ia into the gaps 19 formed between the piled-up sheet conductors of the pipeline detection cables (PLDl) to be connected with each other, and apply heat to the thermal contraction tube 7 to thereby closely contract the thermal contraction tube 7 to the electric conducting bar Ia and the coverings 13 of the pipeline detection cables (PLDl). When the thermal contraction tube 7 is thermally contracted after the electric conducting bar Ia is inserted into the gap 19 between the piled-up sheet conductors 17a and 17b, the inner face of the thermal contraction tube 7, the electric conducting bar Ia and the coverings 13 are sealed closely. The connection work of the pipeline detection cables can be very rapidly and easily carried out by the worker in the installation field of the rigid plastic conduits 23 a and 23b.

[82]

[83] FIG. 9 illustrates a state where only the coverings 13 of connected portions of the pipeline detection cables (PLDl) are partially removed after the worker cuts the pipeline detection cables (PLDl) according to the length of the rigid plastic conduits to be installed and attaches them to the outer surfaces of the rigid plastic conduits 23a and 23b, and FIG. 10 illustrates a state where the pipeline detection cables (PLDl) are connected with each other according to the above-mentioned process.

[84]

[85] As shown in FIGS. 5 to 10, if the worker uses the pipeline detection cables using the piled-up sheet conductors and the connection method of the pipeline detection cables according to the present invention, the worker can connect the adjacent pipeline detection cables (PLDl) with each other only by a simple manipulation after cutting the pipeline detection cables (PLDl) according to the length of the rigid plastic conduits to be installed in the field and closely attaching them to the rigid plastic conduits 23 a and 23b. Once the pipeline detection cables (PLDl) are connected with each other, since the entire pipeline detection cables are in close contact with the rigid plastic conduits, it can prevent the easy separation of the connected portions of the pipeline detection cables from each other even when soil or concrete is poured to bury the rigid plastic conduits in the ground, and surely prevent penetration of moisture into the pipeline detection cables after burying.

[86]

Mode for the Invention

[87] <Second Embodiment

[88] Referring to FIG. 11, a pipeline detection cable (PLD2) according to the present invention may be manufactured through the steps of mounting a release sheet 25, which is wider than sheet conductors 17a and 17b, on the back of the piled-up sheet conductors 17a and 17b and forming a covering 13 in such a way as to extrude or laminate synthetic resin outside. For the extrusion-molding of the covering 13, thermoplastic resin having an expansion and contraction force to some extent, such as PVC, urethane, PE, and so on, is used, but for the laminating-molding of the covering 13, a thermosetting adhesive film is used.

[89]

[90] For the release sheet 25, sheets of various kinds, such as aluminum sheets, aluminum coating sheets, paper, synthetic resin impregnated paper, synthetic resin sheets, and so on may be used. In this instance, a melting point of the release sheet 25 must be always higher than a melting point of synthetic resin used in the covering. The reason is that it is necessary to prevent melting and bonding between the release sheet 25 and the covering 13 or between the release sheet 25 and the sheet conductors 17a and 17b by heat of the melted synthetic resin during the extrusion-molding of the covering.

[91]

[92] Referring to FIG. 12, as described above, when the release sheet 25 is mounted on the back of the piled-up sheet conductors 17a and 17b, the worker extrudes the covering from a lateral direction to thereby easily form a hollow around the sheet conductors, so that the electric conducting bar can be easily inserted between contact surfaces of the sheet conductors due to the hollow. As described in the second preferred embodiment, in case where the piled sheet conductors 17a and 17b are arranged in two rows in parallel inside the covering 13, in a state where two electric conducting bars Ib are separated from each other as long as a separation distance of the piled-up sheet conductors, the electric conducting bars Ib can be more easily inserted between the sheet conductors when a connector having an insulated hand-grip 11 formed at the center thereof is used.

[93]

[94] FIG. 12 illustrates an example that the electric conducting bars Ib are flat bars.

However, in order to easily insert the electric conducting bars into gaps formed between the contact surfaces of the piled-up sheet conductors 17a and 17b, as shown in FIGS. 16 and 17, electric conducting bars Ic and Id may be formed in such a way that central portions of linear conductors are repeatedly bent to thereby form terminals tl and t2 of a round-shaped front end form formed every bent portion, and the insulated hand-grip 11 is disposed at the center of the electric conducting bars Ic and Id.

[95]

[96] <Third Embodiment

[97] Referring to FIGS. 13 and 14, a pipeline detection cable (PLD3) according to the present invention may be manufactured through the steps of wrapping piled-up sheet conductors 17a and 17b with a release film 27 and forming a covering 13 in such a way as to extrude or laminate synthetic resin outside. It is preferable that a material of the release film 27 is the same as the release sheet 25 or thinner than the material of the release sheet 25. Also, in this instance, due to the above reason, a melting point of the release film 27 must be always higher than the melting point of synthetic resin used in the covering.

[98]

[99] Referring to FIG. 15, also in case where the covering 13 is molded in such a way as to wrap the entire of the piled-up sheet conductors 17a and 17b with the release film 27, the worker extrudes the covering from a lateral direction to thereby easily form a hollow around the sheet conductors, so that the electric conducting bar can be easily inserted between contact surfaces of the sheet conductors due to the hollow.

[100]

[101] Also, in this instance, as shown in FIGS. 16 and 17, electric conducting bars Ic can be easily inserted into gaps formed between contact surfaces of the sheet conductors when the electric conducting bars Ic having terminals tl and t2 of a round-bent front end form and a connector having the insulated hand-grip 11 are used.

[102] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

[1] A pipeline detection cable comprising: two band-shaped sheet conductors vertically piled up inside a synthetic resin covering in such a way that contact surfaces thereof are separable from each other. [2] The pipeline detection cable according to claim 1, wherein a release sheet, which is wider than the sheet conductors, is mounted on the back of the piled-up sheet conductors in such a way as to form a hollow around the piled-up sheet conductors inside the covering. [3] The pipeline detection cable according to claim 1, wherein a release film wraps the entire piled-up sheet conductors in such a way as to form a hollow around the piled-up sheet conductors inside the covering. [4] A method of connecting the pipeline detection cables according to one of claims

1 to 3 comprising the steps of: preparing an electric conducting bar, which can be inserted into gaps formed between contact surfaces of sheet conductors of the pipeline detection cables; lying the pipeline detection cables, which will be connected with each other, adjacent to each other; partly inserting the electric conducting bar into the gaps formed between the contact surfaces of the sheet conductors of the two adjacent pipeline detection cables; and sealing the outside of the connected portion of the pipeline detection cables using a thermal contraction tube. [5] The method of connecting the pipeline detection cables according to claim 4, wherein the electric conducting bar comprises terminals of a round-shaped front end form formed every bent portion in such a way as to repeatedly bend the central portion of a linear conductor, and an insulated hand-grip is disposed at the center of the electric conducting bar.