JP2011113675A - Connection method of terminal to flexible flat cable and terminal - Google Patents

Abstract

Provided is a method capable of electrically connecting a conductor and a terminal of a flexible flat cable (FFC) with a simple facility and process without peeling off an insulating coating.
In a method of electrically connecting a terminal to an FFC 10 in which flat conductors 11 are arranged and covered with a resin insulating coating 12, a terminal 1 having a pair of clamping pieces 5 on the base end side is used as the terminal. A step of inserting an FFC between the pair of holding pieces and positioning the holding piece at a position overlapping with the conductor; and after the step, the holding pieces are brought into contact with each holding piece outside (upper and lower). In this state, two electrodes 21 and 22 are arranged, and while pressing the sandwiching piece with the two electrodes, an electric current is passed through the terminal to generate heat by Joule heat, and thereby an insulating coating of a portion where the sandwiching piece comes into contact is formed. The step of dissolving and bringing the holding piece into contact with both sides of the conductor, and subsequently passing the current through the conductor between the pair of holding pieces by two electrodes following the step, the contact point between the holding piece and the conductor is determined. A resistance welding process; To Bei.
[Selection] Figure 2

Description

  The present invention relates to a method for connecting a terminal to a flexible flat cable, and a terminal used for carrying out the method.

  As a method of connecting terminals such as connectors to a flexible flat cable (hereinafter sometimes referred to as “FFC” for short) in which a plurality of flat conductors are lined up and covered with a resin insulation coating, the insulation coating of the necessary part is removed. There is a method of connecting the terminal directly to the exposed conductor by soldering or welding. For example, resistance welding (spot welding or the like) is mainly used as a welding method.

  Thus, the method of connecting the terminal to the conductor after removing the insulating coating requires two steps, that is, a step of removing the insulating coating and a step of connecting the terminal to the conductor by welding or the like, which is troublesome. Thus, a method has been developed in which the terminal is electrically connected to the FFC conductor without removing the FFC insulation coating.

  As one example of this method, there is a method called piercing in which a needle-like or nail-like piercing protrusion is provided on a terminal and the terminal is pierced into a conductor from above the insulating coating to connect the terminals.

  As another example, as described in Patent Document 1, a terminal is arranged on one surface of an FFC, the FFC and the terminal are sheared simultaneously to form a cut and raised portion, and the cut and raised portion is crushed. There is a method of connecting a terminal and a conductor.

  As another example, as described in Patent Document 2, the FFC and the terminal are overlapped and sandwiched between the horn and the anvil of the ultrasonic welding apparatus, and the ultrasonic wave is pressed while pressing the FFC and the terminal with the horn and the anvil. There is a method in which the insulating coating of the FFC is heated and melted by applying vibration, the terminal is brought into direct contact with the conductor of the FFC, and the terminal and the conductor are welded by further ultrasonic vibration.

JP 2007-265720 A JP 2009-87831 A

  However, the method of electrically connecting the terminal to the FFC conductor without removing the above-described conventional FFC insulation coating has the following problems.

  First, the connection method called piercing needs to be provided with a piercing protrusion on the terminal in advance, so that the shape of the terminal is complicated, which tends to increase the cost, and the FFC conductor and the terminal are simply in contact with each other in the connected state. However, there was a problem that the connection was likely to become unstable. Moreover, since the connection method described in Patent Document 1 requires that the FFC and the terminal be sheared at the same time and the cut and raised pieces formed by the shearing be crushed, the work process and work equipment are likely to be complicated. there were. Moreover, since the connection method described in Patent Document 2 requires the use of an ultrasonic welding apparatus, there is a problem that the equipment tends to be complicated.

  The present invention has been made in view of the above-described circumstances, and the object thereof is to electrically connect the conductor and the terminal of the flexible flat cable at a low cost with simple equipment and process without removing the insulating coating. It is in providing the method which can be connected, and the terminal used for the method.

In order to achieve the above-described object, the connection method according to the present invention is characterized by the following (1) to (2).
(1) In a method for connecting a terminal to a flexible flat cable, the terminals are electrically connected to a flexible flat cable in which flat conductors are arranged and covered with a resin insulation coating.
As the terminal, a terminal having a pair of holding pieces on the base end side is used, and the flexible flat cable is inserted between the pair of holding pieces of the terminal so as to overlap the conductor of the flexible flat cable. Positioning the pair of clamping pieces;
After the step, two electrodes are arranged outside the pair of sandwiching pieces in contact with the sandwiching pieces, respectively, and the pair of sandwiching pieces are pressed by the two electrodes, and current is applied to the terminals. To cause the terminals to generate heat by Joule heat, thereby dissolving the insulating coating of the flexible flat cable at the portion where the pair of sandwiching pieces contact, and the pair of sandwiching pieces on both sides of the conductor of the flexible flat cable Contacting with
Subsequent to the step, by the two electrodes, a current is passed through the conductor between the pair of sandwiching pieces, whereby the contact point between the sandwiching piece and the conductor is resistance-welded,
Comprising.
(2) In the connection method having the configuration (1) above,
The entire terminal is formed by punching a flat metal plate with a certain thickness,
On the base end side of the terminal, a U-shaped connecting portion having a connecting plate portion and the pair of sandwiching pieces extending substantially parallel to each other from the connecting plate portion is provided,
On the tip side of the terminal, an electrical connection portion with a mating terminal extending from the connecting plate portion is provided,
Protrusions projecting inwardly between the sandwiching pieces from the proximal end portions of the respective sandwiching pieces are provided on the side edges facing each other on the distal end sides of the pair of sandwiching pieces, and the flexible flat is interposed between the projecting parts. There must be enough clearance for the cable to be inserted.

According to the connection method of the above configuration (1), a flexible flat cable is inserted between a pair of holding pieces formed on the base end side of the terminal, and the holding pieces are held by the electrodes arranged outside the holding pieces in this state. The terminal can be welded to the conductor after the insulation coating has been melted by Joule heat by simply passing an electric current between the electrodes while applying pressure, which simplifies the process and equipment and lowers costs compared to the conventional example. At the same time, the connection state can be stabilized. In addition, since only the current flows while applying pressure with the electrodes, by using the electrodes having a size over a plurality of arranged terminals, a plurality of conductors and a plurality of terminals of the multi-core flexible flat cable are connected together. It is also possible to improve productivity.
According to the connection method of the above configuration (2), since the flexible flat cable is inserted between the holding pieces of the terminals formed by punching the flat plate, even between the flexible flat cables having a small inter-conductor pitch, The terminals can be connected to the respective conductors while arranging the terminals at a small pitch according to the pitch. Moreover, since the convex part is provided in the side edge part which a pair of clamping piece mutually opposes, and the convex part contacts the plate | board surface of a flexible flat cable, the load by pressurization and the heat | fever of a terminal contact | win a convex part. It can concentrate on a part and can melt | dissolve insulation coating and can weld with a conductor efficiently. Moreover, since the convex part protrudes from the base end part of the sandwiching piece, deformation can be suppressed even when a springback acts on the sandwiching piece after pressurizing and welding.

In order to achieve the above-described object, a terminal according to the present invention is characterized by the following (3).
(3) A terminal having a pair of clamping pieces on the base end side, which is used in a method of connecting a terminal to the flexible flat cable having the configuration of (1),
The whole is formed by punching a flat metal plate with a certain thickness,
A U-shaped connecting portion having a connecting plate portion and the pair of sandwiching pieces extending substantially parallel to each other from the connecting plate portion is provided on the proximal end side, and forward from the connecting plate portion to the distal end side. An electrical connection with the mating terminal is provided,
Protrusions projecting inwardly between the sandwiching pieces from the proximal end portions of the respective sandwiching pieces are provided on the side edges facing each other on the distal end sides of the pair of sandwiching pieces, and the flexible flat is interposed between the projecting parts. A gap for cable insertion is secured.

  According to the terminal having the configuration of (3) above, a flexible flat cable is inserted into the gap between the convex portions of the sandwiching piece, and the current between the electrodes is pressed while pressing the sandwiching piece with the electrode disposed outside the sandwiching piece. , The insulation coating is melted by Joule heat and can be welded to the conductor. Therefore, it can contribute to facilitation of connection with a flexible flat cable. In addition, since a pair of sandwiching pieces are formed by punching a flat plate, even a flexible flat cable with a small inter-conductor pitch can be connected to each conductor while being arranged at a small pitch that matches the pitch between the conductors. Can do. Moreover, since the convex part provided in the side edge part of the clamping piece comes into contact with the plate surface of the flexible flat cable, the load due to pressure and the heat of the terminal can be concentrated on the part where the convex part hits. The melting of the coating and the welding with the conductor can proceed efficiently. Moreover, since the convex part protrudes from the base end part of a clamping piece, even when a springback acts on a clamping piece after pressurizing and welding, a deformation | transformation can be suppressed.

  According to the present invention, the terminal can be welded to the conductor after the insulating coating of the flexible flat cable is melted only by passing an electric current between the electrodes. Therefore, the process and equipment can be simplified and the cost can be reduced as compared with the conventional example, and the connection state can be stabilized.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

It is a perspective view of the terminal used for the connection method of the embodiment of the present invention. (A)-(c) is process explanatory drawing of the connection method of the embodiment. It is a perspective view which shows the example in the case of connecting a some terminal collectively to a multicore flexible flat cable.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of a terminal used in the connection method of the embodiment, and FIGS. 2A to 2C are process explanatory diagrams of the connection method of the embodiment.

  The terminal connection method of this embodiment is a method of electrically connecting a terminal to a flexible flat cable (FFC) 10 in which a plurality of flat conductors 11 are arranged and covered with a resin insulation coating 12, as shown in FIG. A terminal 1 having the structure as shown is used.

  The terminal 1 has a pair of sandwiching pieces 5 on the base end side, and is formed by punching a thick metal flat plate as a whole. A U-shaped connecting portion 3 having a connecting plate portion 4 and a pair of sandwiching pieces 5 extending from the connecting plate portion 4 substantially in parallel to each other is provided on the base end side of the terminal 1. Further, a pin-shaped electrical connection portion 2 extending forward from the connecting plate portion 4 is provided on the distal end side. This pin-shaped electrical connection part 2 is a part which fits with the other party female terminal, and is formed in cross-sectional substantially square shape. Therefore, the thickness of the terminal 1 is set to a size necessary for making the electrical connection portion 2 having a substantially square cross section.

  Further, convex portions 5 a that protrude inward between the sandwiching pieces 5 from the base end portions of the respective sandwiching pieces 5 are provided on the side edge portions facing each other on the distal end side in the extending direction of the pair of sandwiching pieces 5. A gap into which the flexible flat cable 10 is inserted is secured between the convex portions 5a. The gap is slightly larger than the thickness of the flexible flat cable 10 in order to improve the insertion property of the flexible flat cable 10, but it is not necessarily so, and the gap is slightly smaller than the thickness of the flexible flat cable 10. It may be set to a small value so that when the flexible flat cable 10 is inserted, the holding piece 5 can be inserted in a slightly opened state. Further, a semicircular cutout portion 7 for absorbing a spring back of the sandwiching piece 5 is provided at a portion where the pair of sandwiching pieces 5 of the terminal 1 are connected to the connecting plate portion 4.

  When connecting the terminal 1 to the flexible flat cable 10, first, as shown in FIG. 2A, the longitudinal end portion of the flexible flat cable 10 is inserted between the pair of sandwiching pieces 5 of the terminal 1. Thus, the pair of sandwiching pieces 5 are positioned at positions overlapping the conductor 11 of the flexible flat cable 10.

  Next, as shown in FIG. 2 (b), two electrodes 21 and 22 are disposed outside the pair of sandwiching pieces 5 (upper and lower in the drawing) in contact with the respective sandwiching pieces 5, respectively. While energizing between the electrodes 21 and 22 while pressing the pair of sandwiching pieces 5 with the two electrodes 21 and 22, a current is passed through the terminal 1 in the path as indicated by the arrow A, and the terminal 1 is heated by Joule heat. Thereby, as shown in FIG. 2 (c), the insulating coating 12 of the flexible flat cable 10 of the portion P in contact with the convex portion 5a of the pair of sandwiching pieces 5 is dissolved, and the convex portion 5a of the pair of sandwiching pieces 5 is obtained. Are brought into contact with both surfaces of the conductor 11 of the flexible flat cable 10.

  Next, a current is caused to flow between the pair of sandwiching pieces 5 through the conductor 11 through the path of the arrow B by the two electrodes 21 and 22, thereby causing a contact point (range indicated by P) between the sandwiching piece 5 and the conductor 11. ) Resistance welding. Through the above steps, the terminal 1 can be electrically connected to the flexible flat cable 10.

  As described above, the flexible flat cable 10 is inserted between the pair of holding pieces 5 formed on the base end side of the terminal 1, and the holding pieces 5 are added by the electrodes 21 and 22 arranged outside the holding pieces 5 in this state. The terminal 1 can be welded to the conductor 11 after the insulation coating 12 is melted by Joule heat only by passing an electric current between the electrodes 21 and 22, thus simplifying the process and equipment compared to the conventional example. The cost can be reduced and the connection state can be stabilized.

  Further, since the current only flows while being pressed by the electrodes 21 and 22, the multi-core flexible flat cable 10 can be obtained by using the electrodes 21 having a size extending over a plurality of terminals 1 arranged as shown in FIG. 3. The plurality of conductors 11 and the plurality of terminals 1 can be collectively connected, and productivity can be improved.

  Moreover, in this embodiment, since the flexible flat cable 10 is inserted between a pair of clamping pieces 5 of the terminal 1 formed by punching a flat plate, the conductor 11 can be applied to the flexible flat cable 10 having a small pitch between the conductors 11. The terminals 1 can be connected to the respective conductors 11 while arranging the terminals 1 at a small pitch in accordance with the pitch between them. Moreover, since the convex part 5a is provided in the side edge part which a pair of clamping piece 5 mutually opposes, and the convex part 5a contacts the plate | board surface of the flexible flat cable 10, the load by pressurization and the heat | fever of the terminal 1 are carried out. Can be concentrated on the contacted portion of the convex portion 5a, and the melting of the insulating coating 12 and the welding with the conductor 11 can be efficiently advanced. Moreover, since the convex part 5a protrudes rather than the base end part of the clamping piece 5, even when a spring back acts on the clamping piece 5 after pressurizing and welding, a deformation | transformation can be suppressed. In particular, since the terminal 1 used here is provided with a notch portion 7 at the base end portion of the sandwiching piece 5, the welded sandwiching piece 5 is spring-backed so that the original indicated by the dotted line in FIG. An attempt to return to the position can be more effectively suppressed, and a stable connection state can be easily maintained.

  In order to make it easy to transfer heat from the terminal 1 to the insulating coating 12, it is desirable to secure a reasonably wide area of the surface where the convex portion 5a of the sandwiching piece 5 contacts the insulating coating 12, but in this case Since the terminal 1 is formed by punching a thick metal flat plate, the thickness of the terminal 1 is effective in widening the area of contact with the insulating coating 12. Further, it is useful that the thickness of the terminal 1 is large in order to prevent the terminal 1 from being melted by a large current at the stage of melting the insulating coating 12.

  The present invention is not limited to the above-described embodiments, and modifications, improvements, etc. can be made as appropriate. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

DESCRIPTION OF SYMBOLS 1 Terminal 2 Electrical connection part 3 U-shaped connection part 4 Connecting plate part 5 Clamping piece 5a Convex part 7 Notch part 10 Flexible flat cable 11 Conductor 12 Insulation coating 21, 22 Electrode

Claims (3)

In the terminal connection method for the flexible flat cable, the terminals are electrically connected to the flexible flat cable in which flat conductors are arranged and covered with a resin insulation coating.
As the terminal, a terminal having a pair of holding pieces on the base end side is used, and the flexible flat cable is inserted between the pair of holding pieces of the terminal so as to overlap the conductor of the flexible flat cable. Positioning the pair of clamping pieces;
After the step, two electrodes are arranged outside the pair of sandwiching pieces in contact with the sandwiching pieces, respectively, and the pair of sandwiching pieces are pressed by the two electrodes, and current is applied to the terminals. To cause the terminals to generate heat by Joule heat, thereby dissolving the insulating coating of the flexible flat cable at the portion where the pair of sandwiching pieces contact, and the pair of sandwiching pieces on both sides of the conductor of the flexible flat cable Contacting with
Subsequent to the step, by the two electrodes, a current is passed through the conductor between the pair of sandwiching pieces, whereby the contact point between the sandwiching piece and the conductor is resistance-welded,
A method for connecting terminals to a flexible flat cable. The entire terminal is formed by punching a flat metal plate with a certain thickness,
On the base end side of the terminal, a U-shaped connecting portion having a connecting plate portion and the pair of sandwiching pieces extending substantially parallel to each other from the connecting plate portion is provided,
On the tip side of the terminal, an electrical connection portion with a mating terminal extending from the connecting plate portion is provided,
Protrusions projecting inwardly between the sandwiching pieces from the proximal end portions of the respective sandwiching pieces are provided on the side edges facing each other on the distal end sides of the pair of sandwiching pieces, and the flexible flat is interposed between the projecting parts. The method for connecting terminals to a flexible flat cable according to claim 1, wherein a gap for inserting the cable is secured. A terminal having a pair of clamping pieces on the base end side, which is used in the method for connecting a terminal to the flexible flat cable according to claim 1,
The whole is formed by punching a flat metal plate with a certain thickness,
A U-shaped connecting portion having a connecting plate portion and the pair of sandwiching pieces extending substantially parallel to each other from the connecting plate portion is provided on the proximal end side, and forward from the connecting plate portion to the distal end side. An electrical connection with the mating terminal is provided,
Protrusions projecting inwardly between the sandwiching pieces from the proximal end portions of the respective sandwiching pieces are provided on the side edges facing each other on the distal end sides of the pair of sandwiching pieces, and the flexible flat is interposed between the projecting parts. A terminal for connecting to a flexible flat cable characterized in that a gap for inserting the cable is secured.

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