JP2006156363A - Connection structure and connecting method of shield braid portion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical connection of a braid portion and a terminal of a shielded electric wire easily and surely at low cost without a large-scale device and so on and deterioration of contact property with age. <P>SOLUTION: In a connection structure and a connecting method of shield braid portion in which terminals 1 and 2' are pressure-joined onto the braid portion 13 of a shielded electric wire 15, the terminals 1 and 2' are adhered and electrically connected to the braid portion 13 with a conductive adhesive member 5. The conductive adhesive member 5 is constructed from a conductive tape 3 and a conductive adhesive agent 4 on both surfaces of the conductive tape. A adhesive agent member 19 is constructed from a non-conductive tape 18 and the conductive adhesive agent 4 on a peripheral surface of the non-conductive tape. The conductive adhesive member 20 is constructed from a non-conductive tape 18' and the conductive adhesive agent 4 penetrating into the non-conductive tape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a connection structure and a connection method for a shield braided portion that can prevent deterioration in electrical contact over time when a terminal is crimped and connected to the braided portion of a shielded electric wire.

  Conventionally, when a conductive metal terminal is crimped and connected to a conductive metal braided portion of a shielded electric wire, the outer peripheral surface of the braided portion is a terminal because there is a relatively soft insulating resin inner skin inside the braided portion. Even if crimping is used, the crimping will loosen over time (crimping force will decrease), the electrical resistance between the braided part and the terminal will increase, and the shielding performance (electromagnetic shielding) of the core wire, which is the signal wire of the shielded wire ), And the shield grounding property of connectors and devices using shielded wires has deteriorated.

  Therefore, the present applicant has proposed a connection structure and connection method for the shield braided portion shown in FIGS. 10 (a) to 10 (c) (see Patent Document 1).

  This is because a low melting point bonding material 21 such as solder is applied to the inner surface of the crimping portion 2 of the terminal 1 for shielding (earth), and the crimping portion 2 of the terminal 1 is set on the braided portion (braided wire) 13 of the shielded electric wire 15. Then, the low-melting-point bonding material 21 is melted by pressing the pressure-bonding portion 2 with the lower mold (anvil) 23 while vibrating the pressure-bonding upper mold 22 as an ultrasonic horn. The braided portion 13 and the crimping portion 2 of the terminal 1 are welded.

  As shown in FIG. 10A, another main terminal 16 is crimped and connected to the conductive metal core wire 11 of the shielded electric wire 15. Since the core wire 11 is a metal having low contractibility, the main terminal 16 is firmly connected to each strand of the core wire 11 without loosening with time. The main terminal 16 is supplied with a main current, a signal current, or the like. An insulating endothelium 12 is provided outside the core wire 11, a braided portion 13 is provided outside the insulating endothelium 12, and an insulating outer skin 14 is provided outside the braided portion 13.

The shield terminal 1 in FIG. 10B has a substantially L-shaped tab portion 8, and the tab portion 8 is positioned in parallel with the main terminal 16, and the terminal 1 and the braided portion 13 in FIG. After the crimping connection, the terminals 1 and 16 are accommodated in a connector housing to constitute a connector (not shown), and are connected to a mating connector (not shown) such as a device or a wire harness. For example, the terminal 1 grounds an electrical noise of a connector or a device through the braided portion 13 to the outside.
JP 2000-58153 A (pages 3 to 4, FIG. 2)

  However, the above-described conventional shield braid connection structure and connection method require a device that vibrates the upper die 22 for crimping as an ultrasonic horn, which complicates, enlarges, and increases the size of the crimping device. There was a problem of cost. In addition, there is a concern that the durability of the synthetic resin-made insulating endothelium 12 is lowered due to the thermal effect associated with the melting of the low melting point bonding material 21.

  In view of the above-mentioned points, the present invention uses a large-scale device or does not give a thermal effect to the electrical connection between the braided portion of the shielded electric wire and the terminal at a low cost without a deterioration in contact with time. It is an object of the present invention to provide a shield braided portion connection structure and a connection method that can be easily and reliably performed.

To achieve the above object, the shield braided portion connection structure according to claim 1 of the present invention is a shield braided portion connecting structure in which a terminal is crimp-connected to a braided portion of a shielded electric wire. Are bonded and electrically connected by a conductive adhesive member.

  With the above configuration, even when the braided portion is pressed against the inner insulating endothelium by the crimping force of the terminal and the insulating endothelium shrinks with time, and the contact pressure between the braided portion and the terminal decreases, the braided portion and the terminal Is bonded by the conductive adhesive member, the electrical resistance between the braided portion and the terminal does not increase, and the braided portion and the terminal are maintained in a good electrical connection state for a long period of time.

  The shield braided portion connection structure according to claim 2 is the shield braided portion connection structure according to claim 1, wherein the conductive adhesive member includes a conductive tape, and a conductive adhesive on both sides of the conductive tape. It is characterized by comprising.

  With the above configuration, the conductive adhesive (conductive adhesive) on the outer surface side of the conductive tape adheres to the inner surface of the terminal, and the conductive adhesive (conductive adhesive) on the inner surface side of the conductive tape becomes the braided portion. Adhering to the outer surface, the outer surface side of the conductive tape is electrically connected to the terminal, the inner surface side of the conductive tape is electrically connected to the braided portion, and the terminal and the braided portion are electrically connected via the conductive tape Is done. The conductive adhesive only needs to be attached to at least the front and back surfaces (internal and external surfaces) of the conductive tape, and may be attached to the outer peripheral surfaces (front and back surfaces and side surfaces) of the conductive tape.

  The shield braided portion connection structure according to claim 3 is the shield braided portion connection structure according to claim 1, wherein the conductive adhesive member includes a non-conductive tape and a conductive bond between an outer peripheral surface of the non-conductive tape. It is characterized by comprising an agent.

  With the above configuration, the conductive adhesive (conductive adhesive) on the outer surface side of the nonconductive tape adheres to the inner surface of the terminal, and the conductive adhesive (conductive adhesive) on the inner surface side of the nonconductive tape is braided. The conductive adhesive on the inner and outer surfaces (front and back surfaces) of the nonconductive tape is electrically connected with the conductive adhesive on the side surface (one side surface or both side surfaces) of the nonconductive tape. The terminal and the braided portion are electrically connected via the conductive adhesive on the outer peripheral surface of the nonconductive tape.

  The shield braided portion connecting structure according to claim 4 is the shield braided portion connecting structure according to claim 1, wherein the conductive adhesive member includes a non-conductive tape and a conductive adhesive penetrating the non-conductive tape. It is characterized by comprising.

  With the above configuration, the conductive adhesive on the outer surface side of the nonconductive tape adheres to the inner surface of the terminal, the conductive adhesive on the inner surface side of the nonconductive tape adheres to the outer surface of the braided portion, The conductive adhesive on the outer surface side and the inner surface side are electrically connected by the conductive adhesive on the inner side of the nonconductive tape. The terminal and the braided portion are electrically connected via the outer surface side, the inner surface side, and the inner conductive adhesive of the non-conductive tape. As the non-conductive tape, for example, a porous (porous) material such as a nonwoven fabric is preferably used. As the conductive adhesive, it is preferable to use an adhesive that has low viscosity and good permeability and exhibits tackiness after penetration.

  According to a fifth aspect of the present invention, there is provided a method for connecting a shield braided portion, wherein a conductive adhesive member is provided on an inner surface of a crimped portion of a terminal or an outer surface of a braided portion of a shielded electric wire, and the conductive adhesive member is provided between the terminal and the braided portion. The terminal and the braided portion are crimped and connected in a positioned state.

  With the above configuration, even when the braided portion is pressed against the inner insulating endothelium by the crimping force of the terminal and the insulating endothelium shrinks with time, and the contact pressure between the braided portion and the terminal decreases, the braided portion and the terminal Is bonded by the conductive adhesive member, the electrical resistance between the braided portion and the terminal does not increase, and the braided portion and the terminal are maintained in a good electrical connection state for a long period of time. The conductive adhesive member is composed of, for example, a conductive tape and a conductive adhesive on both sides of the conductive tape, or a non-conductive tape and a conductive adhesive on the outer peripheral surface of the non-conductive tape. Or a non-conductive tape and a conductive adhesive that has penetrated the non-conductive tape.

  As described above, according to the first and fifth aspects of the present invention, the shield contact property between the braided portion and the terminal does not deteriorate even when the shielded wire changes with time, and a good shield with the shielded wire can be obtained over a long period of time. Performance is maintained. In addition, the existing crimping machine can be used to crimp and bond the braided portion and the terminal easily and at low cost, and the cost and productivity of the shielded electric wire with terminal can be reduced. In addition, since the braided portion and the terminal can be bonded without being affected by heat, the durability of the insulating endothelium of the shielded wire is improved.

  According to the invention described in claim 2, the shield connection structure is reduced in weight and diameter by using the conductive tape, and the conductive tape with the conductive adhesive is cut or peeled off like a normal double-sided tape. The tape can be peeled off and handled easily, and the workability of bonding the conductive tape to the terminal and the braided portion is improved.

  According to the invention described in claim 3, the shield connection structure is reduced in weight and diameter by using a non-conductive tape with a conductive adhesive, and the non-conductive tape with a conductive adhesive is used on a normal double-sided surface. It can be easily handled by cutting like a tape or peeling off the release tape, and the workability of bonding the conductive tape to the terminal and the braided portion is improved.

  According to the invention of claim 4, the shield connection structure is reduced in weight and diameter by using a non-conductive tape infiltrated with a conductive adhesive, and the non-conductive tape in which the conductive adhesive has penetrated is usually used. It can be easily handled by cutting it like a double-sided tape or peeling off the peeling tape, and the workability of bonding the conductive tape to the terminal and the braided portion is improved.

1 to 5 show an embodiment of a connection structure and connection method for a shield braided portion according to the present invention.

  In FIG. 1, a conductive tape 3 is bonded to the inner surface of a crimping portion 2 of a conductive metal shield (ground) terminal 1, and a conductive adhesive (conductive The adhesive tape 4 is applied, and the conductive tape 3 is adhesively fixed and electrically connected to the inner surface of the crimping portion 2 with the conductive adhesive 4 on the back surface of the tape.

  As shown in FIG. 4, a conductive metal braided portion (braided wire) 13 of the shielded electric wire 15 is adhesively fixed and electrically connected to the surface of the conductive tape 3 by the conductive adhesive 4 on the tape surface at the same time as pressing.

  As shown in FIG. 2, the surface of the conductive tape 3 is covered with a peelable insulating tape (release paper) 6 when not in use, and in this state, like a normal double-sided tape (not shown), it is spirally wound. The back side of the conductive tape 3 is covered with a lower insulating tape (not shown). When the conductive tape 3 is formed flat in a sheet shape, both surfaces of the conductive tape 3 are covered with a peelable insulating tape 6.

  As the conductive tape 3, it is preferable to use a conductive metal foil such as a copper foil or an aluminum foil. A net-like metal such as a braided portion may be used instead of the metal foil.

  The conductive adhesive 4 on both sides of the conductive tape 3 includes an adhesive such as an epoxy resin adhesive, a hot melt adhesive, a rubber based adhesive, an elastic adhesive, a phenol resin adhesive, conductive metal, What mixed fiber (fiber), such as carbon, and powder is preferred.

  Alternatively, it is also possible to directly use the conductive tape 3 in which a fiber such as a conductive metal or carbon is mixed as a base material inside the adhesive without using a metal foil or the like. Also in this case, the conductive tape 3 is covered with the release paper 6 to prevent unexpected adhesion with the outside. Alternatively, a conductive non-conductive tape (tape body) such as non-woven fabric in which a conductive adhesive (conductive adhesive) 4 is impregnated (permeated) may be used as the conductive tape 3. Is possible. In these cases, the conductive tape 3 itself is called a conductive adhesive member.

  The conductive tape 3 is appropriately cut into a length and shape at the time of use, and the insulating tape 6 is peeled off and adhered and fixed to the inner surface of the crimping portion 2 of the shielding terminal 1 as shown in FIG.

  As an example, as shown in FIG. 3, with the insulating tape 6 attached to the surface, the conductive tape 3 is sucked from the insulating tape 6 side by the suction jig 7 while the conductive tape 3 is applied to the crimping portion 2 of the terminal 1. The back surface (the exposed side of the conductive adhesive 4) is pressed and pasted. Thereafter, the insulating tape 6 on the surface side is peeled off by hand or suction of the suction jig 7, and the pressure bonding shown in FIG. 4 is performed.

  The suction jig 7 is formed in a substantially U shape that matches the shape of the crimping portion 2 of the terminal 1 and has a plurality (at least one each on the left and right) holes (not shown) for sucking the conductive tape 3. The hole is connected to a vacuum machine (not shown).

  The suction operation described above corresponds to an automatic crimping machine (not shown). In the case of various kinds of small-scale production, the conductive tape 3 can be manually attached to the crimping portion 2 of the terminal 1.

  The conductive tape 3 is cut with a punch and die or a cutter blade (not shown) corresponding to an automatic crimping machine, or in the case of manual work, a scissor, a tape cutter for cutting a wound tape, etc. (not shown) Can also be performed.

  The terminal 1 of FIG. 1 has a substantially L-shaped or U-shaped plate-like tab portion 8 at the base end of the crimping portion 2 bent in a substantially U shape. The crimping part 2 is composed of a pair of left and right crimping pieces 9 and a curved bottom part 10 for raising the crimping piece 9, and the bottom part 10 continues to the tab part 8 as a substrate part.

  The terminal 1 in FIG. 1 is merely an example, and other terminals (not shown) having a substrate portion following the crimping portion and an outer contact portion such as a cylindrical or rectangular tube shape following the substrate portion are used. It is also possible to do. This type of terminal has been proposed by the present applicant in, for example, Japanese Patent Laid-Open No. 2003-151694, and the core wire of the shielded wire (coaxial cable) is connected to another main terminal, and the main terminal is insulated inside the outer contact portion. It is accommodated in a resin connector housing, and the outer contact portion is positioned so as to cover the outer periphery of the connector housing.

  Further, as the other terminal (not shown), a terminal having a hook-shaped electric contact portion following the crimping portion and having the hook-shaped electric contact portion in contact with the conductive portion for grounding of the connector housing is used. It is also possible.

  Further, the crimping portion 2 is not limited to the one having the pair of crimping pieces 9, and a cylindrical one may be used and connected to the braided portion 13 of the shielded electric wire 15 by caulking all around such as swaging. Is possible.

  After bonding the conductive tape 3 to the inner surface of the crimping part 2 of the terminal 1 of FIG. 1, the braided part 13 of the shielded electric wire 15 is set inside the crimping part 2, and the existing crimping machine similar to the conventional example of FIG. The crimping portion 2 is crimped into a cylindrical shape as shown in FIG. 4 between the upper die (the conventional ultrasonic vibration mechanism is unnecessary) and the lower die.

  Alternatively, the conductive tape 3 is not provided on the crimping portion 2 of the terminal 1 in FIG. 1, and the same conductive tape 3 is adhered to the outer peripheral surface of the braided portion 13 of the shielded electric wire 15 in FIG. The braided portion 13 is set inside, and the crimping portion 2 is added in a cylindrical shape as shown in FIG. 4 between the upper die of a similar existing crimping machine (the conventional ultrasonic vibration mechanism is unnecessary) and the lower die. Tighten.

  As a result, as shown in FIG. 5 (AA sectional view of FIG. 4), the conductive tape 3 is closely attached between the crimping portion 2 and the braided portion 13 without a gap, and the outer periphery of the conductive tape 3 is located. The surface is bonded and fixed to the inner peripheral surface of the crimping portion 2 with the conductive adhesive 4, and the inner peripheral surface of the conductive tape 3 is bonded and fixed to the outer peripheral surface of the braided portion 13 with the conductive adhesive 4, The braided portion 13 is firmly fixed via the conductive tape 3 and the conductive adhesive 4 on both sides thereof, and is reliably electrically connected.

  An insulating endothelium 12 made of synthetic resin is located inside the braided portion 13, and a core wire 11 made of conductive metal is located inside the insulating endothelium 12. The core wire 11 is connected in advance or after connection of the shielding terminal 1. As shown in FIG. 1, the main terminal 16 is crimped and connected, the synthetic resin insulating sheath 14 is located outside the braided portion 13, and the cylindrical crimping portion 2 of the terminal 1 and the insulating sheath 14 have substantially the same outer diameter. It is located coaxially in the front-back direction.

  After the crimping portion 2 of the terminal 1 is crimped to the braided portion 13, the insulating endothelium 12 inside the braided portion 13 is gradually reduced in diameter by the crimping force, and loosening occurs between the braided portion 13 and the crimped portion 2. Even so, since the braided portion 13 and the crimping portion 2 are firmly joined so as not to be separated by the conductive tape 3 with the conductive adhesive 4, a gap is formed between the braided portion 13 and the insulating endothelium 12. Even if it occurs, the electrical connection performance between the braided portion 13 and the crimping portion 2 does not deteriorate at all, and the electrical resistance between the braided portion 13 and the crimped portion 2 does not increase. 2 ensures a good conductive performance with a low electrical resistance for a long period of time, and exhibits a good shielding (electromagnetic shielding) performance of the shielded electric wire 15 for a long period of time.

  In the above embodiment, the conductive tape 3 with the conductive adhesive 4 is used as the conductive adhesive member. Instead, the conductive tape 3 is composed of an adhesive conductive paste itself or a conductive adhesive itself. It is also effective to use a conductive adhesive member (not shown).

  The conductive adhesive member composed of the conductive paste itself or the conductive adhesive itself is applied or adhered to the inner surface of the crimping portion 2 of the terminal 1 in FIG. 1, or the outer periphery of the braided portion 13 of the shielded electric wire 15 in FIG. It is made to apply | coat or adhere to a surface, and the crimping | compression-bonding part 2 of the terminal 1 is crimped | bonded to the braided part 13 in the state. The conductive paste and the conductive adhesive are preferably softened at the time of application or adhesion and hardened when left standing.

  In addition, a conductive foil (not shown) such as a copper foil can be used as the braided portion 13 of the shielded electric wire 15, and the conductive adhesive is attached to the connection between the conductive foil and the crimping portion 2 of the terminal 1. It is also effective to use a conductive adhesive member such as the conductive tape 3 or the conductive adhesive itself. The conductive foil may be referred to as a braided portion, or the braided portion 13 and the conductive foil may be collectively referred to as a shield portion.

  The conductive adhesive member 5 made of the conductive tape 3 with the conductive adhesive 4 described above is obtained by attaching the conductive adhesive 4 to the front and back surfaces of the conductive tape 3 as shown in the image diagram of FIG. The conductive adhesive 4 may not be attached to the side surface in the width direction of the conductive tape 3.

  As shown in FIG. 7, when the non-conductive tape 18 is used in place of the conductive tape 3, both the front and back surfaces of the non-conductive tape 18 and the side surfaces in the width direction (only one side may be used, but preferably both side surfaces). A conductive adhesive member 19 is formed by attaching a conductive adhesive (conductive adhesive) 4 to the substrate. The conductive adhesive 4 on the front and back surfaces is electrically connected through the conductive adhesive 4 on the side surface.

  Also, as shown in FIGS. 8A and 8B, when a non-conductive tape such as a non-conductive tape is used as a non-conductive tape, a porous shape as shown in FIG. 8A is used. After the non-conductive tape 18 'is cut to a required length or before being cut, the conductive adhesive 4 is applied to the non-conductive tape 18' as shown in FIG. 8 (b). Or by immersing the non-conductive tape 18 'in a container containing the conductive adhesive 4 and allowing the conductive adhesive 4 to penetrate into the non-conductive tape 18'. The conductive adhesive 4 on the front and back surfaces of 18 ′ is electrically connected by the internal conductive adhesive 4 to form the conductive adhesive member 20.

  FIG. 9 shows a modification of the shield braided portion connection structure and connection method of the present invention. In this example, for convenience of explanation, a conductive adhesive member having the conductive adhesive 4 attached to the front and back surfaces of the conductive tape 3 is used. , 20 etc.) can be used.

  The shield braided portion connecting structure and connecting method uses a terminal code 2 'formed of a crimping portion instead of the shielding terminal 1 (FIG. 1), and a thin wire 17 instead of the tab portion 8 of the terminal 1. Is sandwiched between the terminal 2 'and the braided portion 13 of the shielded electric wire 15, and is connected.

  The shape of the terminal 2 'is the same as the shape of the crimping portion 2 of the terminal 1 in FIG. 1, and the initial shape is substantially U-shaped, and the shape after crimping is annular (cylindrical). As in the previous example, the conductive tape 3 with the conductive adhesive 4 attached to both the front and back surfaces is attached to the inner surface of the terminal 2 ′, and the exposed conductor portion (core wire) 17 b of the electric wire 17 is connected to the conductive tape 3 and the braided portion 13. And is electrically connected to both the terminal 2 ′ and the braided portion 13.

  The conductor portion 17b of the electric wire 17 is brought into close contact with the braided portion 13 by crimping, and is firmly bonded and fixed to the conductive tape 3 and the braided portion 13 on the inner surface side of the terminal 2 'by the conductive adhesive 4. As a result, the electric wire 17 is reliably prevented from coming out over time, and the electric wire 17 and the braided portion 13 maintain a good electrical connection state over a long period of time without loosening over time.

  For example, the conductor portion 17a on the distal end side of the electric wire 17 is connected to a ground portion or the like (not shown) on the device side by screwing or soldering, or a small terminal (not shown) is crimped to the conductor portion 17a. The small terminal is accommodated in the connector housing together with the main terminal 16 and connected to a mating connector (not shown) such as a device or a wire harness. The electric wire 17 is used as a shield earth wire. The conductor portions 17a and 17b at both ends of the electric wire 17 are exposed by peeling the insulating coating 17c.

  As described above, also in the embodiment of FIG. 9, it is possible to use the conductive paste itself, the conductive adhesive itself, or the like instead of the conductive tape 3 and the conductive adhesive 4 as the conductive adhesive member. Further, the conductor portion 17b of the electric wire 17 is temporarily fixed by being sandwiched between the terminal 2 'and the conductive tape 3, and in this state, the braided portion 13 of the shielded electric wire 15 is set in the terminal 2' and the crimping shown in FIG. (Fixed) can also be performed. Further, the shape of the terminal including the terminal 2 ′ and the shape of the main terminal 16 can be appropriately changed as necessary. Moreover, it is also possible to employ swaging as a crimping method.

It is a perspective view which shows one Embodiment of the terminal for shielding in the connection structure and connection method of the shield braid part which concern on this invention. It is a perspective view which shows one Embodiment of the conductive tape similarly affixed on a terminal. It is a perspective view which shows an example of the method of sticking a conductive tape on a terminal. It is a perspective view which shows the shielded electric wire with a terminal which crimped-connected the terminal to the braided part of the shielded electric wire. FIG. 5 is a cross-sectional view taken along the line AA in FIG. It is sectional drawing (description drawing) which shows the conductive adhesive member using a conductive tape. It is sectional drawing (descriptive drawing) which shows one form example of the electrically conductive adhesive member using a nonelectroconductive tape. It is sectional drawing (descriptive drawing) which shows the other example of a conductive adhesive member using a nonelectroconductive tape. It is a perspective view which shows the modification of the connection structure and connection method of the shield braid part of this invention. (A)-(c) is a perspective view which shows the connection structure and connection method of the conventional shield braid part in order of a process.

Explanation of symbols

1, 2 'terminal 2 crimping part 3 conductive tape 4 conductive adhesive 5, 19, 20 conductive adhesive member 13 braided part 15 shielded wire 18, 18' non-conductive tape

Claims (5)

  In a shield braided portion connection structure in which a terminal is crimped and connected to a braided portion of a shielded electric wire, the terminal and the braided portion are bonded and electrically connected by a conductive adhesive member. Connection structure.   The connection structure of the shield braided part according to claim 1, wherein the conductive adhesive member is composed of a conductive tape and a conductive adhesive on both sides of the conductive tape.   The connection structure of the shield braided part according to claim 1, wherein the conductive adhesive member is composed of a non-conductive tape and a conductive adhesive on the outer peripheral surface of the non-conductive tape.   The connection structure of the shield braided part according to claim 1, wherein the conductive adhesive member is composed of a non-conductive tape and a conductive adhesive that has penetrated the non-conductive tape.   A conductive adhesive member is provided on the inner surface of the crimping portion of the terminal or the outer surface of the braided portion of the shielded electric wire, and the terminal and the braided portion are disposed with the conductive adhesive member positioned between the terminal and the braided portion. A method of connecting the shield braided portion, characterized by crimping and connecting.

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