JP3679295B2 - Branch connection structure of flat circuit body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a branch connection structure for flat circuit bodies such as a flexible flat cable (FFC) and a flexible printed circuit (FPC).
[0002]
[Prior art]
In general, when a flat circuit body such as FFC is used for electrical connection between circuits or a circuit is branched, a branch connector is attached to the terminal of the flat circuit body, and this connector is connected to the mating connector. I have to. As such a branched connection structure of a flat circuit body, a technique according to Japanese Patent Laid-Open No. 4-359875 as shown in FIGS. 5 to 7 is known.
[0003]
In this flat circuit body branch connection structure, a terminal 1 as shown in FIG. 5 is used. This terminal 1 has an electrical contact portion 2 electrically connected to the counterpart terminal on the front side, and a crimp piece 3 having a high height (H1) and a crimp piece 4 having a low height (H2) on the rear side. Is formed.
[0004]
Then, as shown in FIG. 6, the terminal portions of the two flexible flat conductor cables 5 and 6 as the flat circuit bodies are shifted from each other by a predetermined distance with respect to the plurality of terminals 1 arranged in parallel. The crimp pieces 3 and 4 are bent to connect the flexible flat conductor cables 5 and 6 and the terminal 1.
[0005]
As shown in FIGS. 6 and 7, the lower flexible flat conductor cable 5 connected to the terminal 1 is electrically connected by the lower crimp piece 4, and the upper flexible flat conductor is connected to the terminal 1. The cable 6 is electrically connected by a high crimp piece 3. As shown in FIG. 7, the flexible flat conductor cable 5 is formed by sandwiching a plurality of conductors 7, 7... Arranged in parallel with a pair of insulating coating layers 9, 9. Yes. The flexible flat conductor cable 6 is formed by sandwiching a plurality of conductors 8 arranged in parallel with each other between a pair of insulating coating layers 10 and 10.
[0006]
In manufacturing such a conventional flat circuit body branch connection structure, the crimp piece 4 of the terminal 1 is pierced into the terminal portion of the flexible flat conductor cable 5 and then a pressing jig (so-called piercing jig). 11 is used to bend the crimp piece 4 so that its tip comes into contact with the conductor 7. Thereafter, the other flexible flat conductor cable 6 is overlapped with a predetermined distance from the end of the connected flexible flat conductor cable 5, and the crimp piece 3 is pierced as shown in FIG. The crimping piece 3 is bent again using the pressing jig 11 and processed so that the tip thereof is in contact with the conductor 8. In this way, a branch connection structure of flat circuit bodies as shown in FIGS. 6 and 7 is manufactured.
[0007]
[Problems to be solved by the invention]
However, the conventional flat circuit body branch connection structure has a problem in that the number of manufacturing steps is large because the connection process is performed twice for each crimp piece 3 and 4 as described above. . In addition, since a tensile force is easily applied to the upper flexible flat conductor cable 6 when the wire harness is assembled, the crimp piece 3 that is electrically connected may be deformed and the contact resistance may increase.
[0008]
Accordingly, an object of the present invention is to provide a branch connection structure of a flat circuit body that can branch a circuit with a small number of manufacturing steps, has high durability, and can improve the reliability of electrical connection. Yes.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the conductive portions of the terminals are respectively connected to the respective conductors at a substantially intermediate position in the longitudinal direction of the flat circuit body in which a plurality of conductors are arranged at predetermined intervals and sandwiched between insulating films. And a branch circuit structure of a flat circuit body that is formed by folding substantially the middle in the longitudinal direction of the flat circuit body, and is connected to the conducting portion and the counterpart terminal of each terminal. A caulking portion is provided between the electrical contact portion and a substantially intermediate position in the longitudinal direction of the flat circuit body, and the conductors in the substantially intermediate position in the longitudinal direction of the flat circuit body are connected by the conductive portion. It is characterized in that it can be freely bent and a substantially intermediate position in the longitudinal direction of the flat circuit body can be bent by using the crimped portion as a folding fulcrum.
[0010]
In this flat circuit body branch connection structure, when electrically connecting the conductive portion of the terminal to each conductor of the flat circuit body, a substantially intermediate position in the longitudinal direction of the flat circuit body is held by the crimped portion of the terminal. Therefore, even if an external force due to pulling acts on the folded flat circuit body or the like, the external force is transmitted to the electrical connection portion between each conductor of the flat circuit body and the conductive portion of the terminal by the holding action of the caulking portion. Is prevented. As described above, the caulking portion of the terminal that is the folding fulcrum of the flat circuit body holds the substantially intermediate position in the longitudinal direction of the flat circuit body, so that the electrical contact portion between each conductor of the flat circuit body and the conducting portion of the terminal Therefore, it is possible to prevent the influence of external force from being exerted on the circuit and to branch the circuit with high reliability.
[0011]
In addition, since a branch circuit is formed by connecting one flat circuit body to the conducting portion of the terminal, the flat circuit body and the terminal can be connected by bending the conducting portion and the crimping portion of the terminal at the same time. Connection is complete. This reduces the number of manufacturing steps. Furthermore, even if the connection strength between each conductor of the flat circuit body and the conductive portion of the terminal is low, the flat circuit body is firmly held by the crimped portion, which causes inconveniences such as poor connection and disconnection of the terminal. Is prevented.
[0012]
The invention according to claim 2 is the flat circuit body branch connection structure according to claim 1, wherein slits are respectively formed between the adjacent conductors of the flat circuit body, and the conducting portion of the terminal. The caulking portions are arranged on the front and rear sides of the slits so that the front and rear caulking portions can be inserted into the slits.
[0013]
In this flat circuit body branch connection structure, the slit formed between adjacent conductors of the flat circuit body makes it easy for the crimped portion of the terminal to securely hold the flat circuit body, and the insertion of the crimped portion is facilitated. Work becomes easy. Further, the flat circuit body is effectively held by the crimping portion of the terminal without contact between the crimping portion of the terminal and the conductor of the flat circuit body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the details of the branch connection structure of a flat circuit body according to the present invention will be described based on embodiments shown in the drawings. In this embodiment, an FFC (flexible flat cable) is applied as the flat circuit body.
[0015]
As shown in FIGS. 1 to 4, the flat circuit body branch connection structure of the present embodiment includes an FFC 21 and a plurality of terminals 22 connected to the FFC 21, and each terminal 22 is not shown in the connector housing 40. It is accommodated in each terminal accommodating chamber.
[0016]
As shown in FIGS. 1 and 2, the FFC 21 has a plurality of conductors 23 made of, for example, rolled copper foil arranged in parallel, and sandwiched between a pair of base films (insulating films) 24 and 24 using an adhesive. Is. In order to attach each terminal 22 at a substantially intermediate position in the longitudinal direction of the FFC 21, slits 25 are respectively formed between adjacent conductors 23, 23 of this portion, and notches 26 are formed on both sides in the width direction of the FFC 21. Each is formed. The slits 25 and the notches 26 are formed in the pair of base films 24 and 24 that are overlaid, and do not reach the conductor 23.
[0017]
As described above, the slits 25 and the notches 26 are formed at substantially intermediate positions in the longitudinal direction of the FFC 21, so that separation portions 27 each having one conductor 23 separated from each other are formed. The width dimension of each separation portion 27 is set to be substantially the same as the width dimension of the connection substrate portion 28 of the terminal 22.
[0018]
As shown in FIGS. 1 and 2, the terminal 22 is accommodated in each terminal accommodating chamber of the connector housing 40, and includes a square cylindrical electric contact portion 29 connected to the mating terminal on the front side. . On the rear side of the electrical contact portion 29, a connection substrate portion 28 is extended by integral molding.
[0019]
A pair of bent holding pieces (clamping portions) 30A, 30A, 30B, and 30B are bent and formed upward from both side edges of the connection substrate portion 28 on the front and rear sides of the connection substrate portion 28 of the terminal 22, respectively. ing. Further, at a position between the pair of bent holding pieces 30A, 30A and the pair of bent holding pieces 30B, 30B of the connection board portion 28 of the terminal 22, a pair of front and rear conductive projections (conductive portions) from both side edges. ) 31 and 31 are bent upward.
[0020]
It should be noted that the distance between each pair of conductive protrusions 31, 31 erected on both sides of the substantially central portion of the connection substrate portion 28 of the terminal 22 is the pair of front and rear bent holding pieces 30 </ b> A, 30 </ b> A, 30 </ b> B. , 30B and the width dimension between the conductors 23 of the FFC 21 are set narrower.
[0021]
Next, a procedure for assembling the FFC 21 and the terminal 22 will be described. First, as shown in FIG. 1, each separation portion 27 of the FFC 21 is pressed against the connection board portion 28 of the corresponding terminal 22, and the pair of bending holding pieces 30 </ b> A, 30 </ b> A, 30 </ b> B, front and rear of the connection board portion 28. It arrange | positions between 30B. At the same time, the portion of the conductor 23 included in each separation portion 27 is pierced by the pair of front and rear conductive protrusions 31, 31 so that the respective conductive protrusions 31 protrude from the upper surface of the FFC 21.
[0022]
In such a state, each bending holding piece 30A, 30B of the terminal 22 and each conduction protrusion 31 are caulked simultaneously using a pressing jig (so-called piercing jig) not shown. Then, each pair of the bending holding pieces 30A and 30B and each of the conduction protrusions 31 are rounded inward to be bent, resulting in a structure as shown in FIGS.
[0023]
Here, each bending holding piece 30 </ b> A, 30 </ b> B of the terminal 22 functions to hold each separation portion 27 of the FFC 21. In addition, each conduction protrusion 31 has a function of electrically connecting the conductor 23 and the terminal 22 in each separation portion 27. Each bent holding piece 30 </ b> A, 30 </ b> B holds the upper surface bent from the side of each separated portion 27.
[0024]
Further, each conductive protrusion 31 passes through the lower base film 24, the conductor 23, and the upper base film 24 of each separation portion 27, and is bent to the upper surface of each separation portion 27. The tip of the common protrusion 31 penetrates the upper layer base film 24 from the upper surface and comes into contact with the conductor 23 again.
[0025]
Next, after the FFC 21 and each terminal 22 are assembled, as shown in FIG. 4, the substantially intermediate position of each separation portion 27 held by the pair of bending holding pieces 30A, 30A is held by the pair of bending holdings. The pieces 30 </ b> A and 30 </ b> A are folded back 180 ° with the folding fulcrum as a fulcrum, and the FFC 21 is overlaid on the connection board portion 28 of the terminal 22. In this way, a branch connection circuit is formed by branching substantially in the middle in the longitudinal direction of the FFC 21. Each terminal 22 to which the FFC 21 is assembled in this way is housed in each terminal housing chamber of the connector housing 40 and connected to the mating terminal in the mating connector. Further, branching connectors (not shown) are connected to both terminals of the branched FFC 21.
[0026]
In such a branch circuit structure of the flat circuit body of the present embodiment, each separation portion 27 of the FFC 21 is folded in a pair of front and rear at positions before and after the conduction protrusion 31 that electrically connects the terminal 22 and the FFC 21. Since the song holding pieces 30A, 30A, 30B, and 30B are respectively held, for example, the upper FFC 21 branched when a tensile force is applied in the direction indicated by the arrow F1 in FIG. It is held by the pieces 30A, 30A. For this reason, it can prevent reliably that the said tensile force F1 affects the contact part of each protrusion 31 for conduction | electrical_connection which is an electrical connection part, and each conductor 23 of upper FFC21.
[0027]
Further, when a pulling force is applied in the direction indicated by the arrow F2 in FIG. 4, the lower FFC 21 that is the source of the branch is held by the pair of bent holding pieces 30B and 30B on the rear side. For this reason, it can prevent reliably that the said tensile force F2 affects the contact part of each conductor protrusion 31 and each conductor 23 of lower FFC21.
[0028]
Furthermore, in this embodiment, since each bending holding piece 30A, 30B of the terminal 22 and each conduction protrusion 31 can be bent simultaneously, the number of manufacturing steps can be reduced.
[0029]
Although the embodiment has been described above, the present invention is not limited to this, and various modifications accompanying the gist of the configuration are possible. For example, in the above-described embodiment, the FFC 21 is applied as the flat circuit body. However, it is of course possible to apply the FPC.
[0030]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the folded portion of the flat circuit body is held by the crimping portion of the terminal, even if an external force such as a pulling force acts on the branched flat circuit body, the flat circuit body The external force is not applied to the electrical connection portion between the conductor of the body and the conducting portion of the terminal, and the electrical connection portion of the conductor of the flat circuit body and the conducting portion of the terminal is not affected. Thereby, the reliability of the electrical connection of a flat circuit body and a terminal can be improved further. In addition, since a branch circuit can be formed by connecting one flat circuit body to the terminal, the branch circuit of the flat circuit body can be reduced with a small number of processes such as bending the conductive portion and the crimping portion of the terminal at the same time. It can be reliably formed at a cost.
[0031]
According to invention of Claim 2, this flat circuit body can be reliably hold | maintained by the crimping part of a terminal through the slit between each conductor which the flat circuit body adjoins. Moreover, since the insertion operation | work to the slit of a crimping part can be simplified, manufacturing cost can be reduced. Furthermore, the flat circuit body can be reliably held without contact between the crimped portion of the terminal and the conductor of the flat circuit body.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a branch connection structure of a flat circuit body according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a branch connection structure of a flat circuit body according to an embodiment of the present invention.
FIG. 3 is a side view showing a branch connection structure of a flat circuit body according to an embodiment of the present invention.
FIG. 4 is a side view showing an assembled state of the flat circuit body branch connection structure according to the embodiment of the present invention;
FIG. 5 is a perspective view of a connection terminal used in a branch connection structure of a conventional flat circuit body.
FIG. 6 is a perspective view showing a branch connection structure of a conventional flat circuit body.
FIG. 7 is a partial cross-sectional view showing a branch connection structure of a conventional flat circuit body.
FIG. 8 is a side view showing a state in the middle of assembling a conventional flat circuit body branch connection structure;
[Explanation of symbols]
21 FFC (Flat Circuit Body)
22 Terminal 23 Conductor 24 Base film (insulating film)
25 Slit 29 Electric contact part 30A, 30B Bending holding piece (caulking part)
31 Protrusion for conduction (conduction part)

Claims (2)

A conductive portion of a terminal is connected to each conductor at a substantially intermediate position in the longitudinal direction of the flat circuit body formed by arranging a plurality of conductors at predetermined intervals and sandwiched by insulating films, and the flat circuit body A flat circuit body branch connection structure in which a branch circuit is formed by folding back substantially the middle in the longitudinal direction,
A caulking portion that holds a substantially intermediate position in the longitudinal direction of the flat circuit body is disposed between the conducting portion of each terminal and the electrical contact portion connected to the counterpart terminal, and the length of the flat circuit body Each of the conductors at a substantially intermediate position in the direction can be connected by the conducting portion, and a substantially intermediate position in the longitudinal direction of the flat circuit body can be bent at the crimping portion as a folding fulcrum. Branch connection structure of circuit body. A flat circuit body branch connection structure according to claim 1,
A slit is formed between the conductors adjacent to each other in the flat circuit body, and caulking portions are disposed on the front and rear sides of the conductive portion of the terminal, respectively. A flat circuit body branch connection structure characterized by being freely inserted into each slit.

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