JP2001135157A - Shielded flat cable and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both adhesion strength between shields and easy-to-separate property at portions to be stripped. SOLUTION: Shields 20 and an outer sheath 24 are integrally formed with a plurality of coated wires 12 to form a flat cable 10. Terminal portions of the flat cable 10 are provided with slits S for parting the respective coated wires 12. The coated outer peripheries of the coated wires 12 are provided with corrugations 16a for reducing the adhesion strength to the shields 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielded flat wire and a method for manufacturing the same, and more particularly, to a shielded flat wire having a shield formed so as to integrally cover a plurality of wires and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a shielded flat electric wire as described above, for example, the one shown in FIG. 12 has been developed. The configuration is such that a plurality of covered electric wires 52 in which a conductor 54 is covered with an insulator 56 and a drain wire 58 composed of only a conductor are arranged in parallel on the same plane, and these covered electric wires 52 and the drain wire 58 are covered with a shield 60. Conduction is made only with the drain wire 58, and the outer periphery of the shield 60 is covered with an insulating outer sheath 64.

In such a shielded flat electric wire 50, the shield 60 is usually formed by a pair of metal foils 62a, 62 sandwiching each wire 52, 58 as shown in FIG.
2b are bonded together with an adhesive.

More specifically, an adhesive is applied to the entire surfaces of the metal foils 62a and 62b facing each other, and the lines 52 and 58 are sandwiched between the metal foils 62a and 62b.
The metal foils 62a, 62 between the two and 58 and on both outer sides thereof
b are bonded to each other with the adhesive.

In the shielded flat electric wire 50 described above, since the shield 60 and the outer sheath 64 are integrated, the distance D between the wires 52 and 58 cannot be changed. Therefore, depending on the wiring form, each line 52, 58
It was necessary to form a slit 61 between them so that the interval could be changed.

When connecting the crimp terminal to the terminal portion of each covered electric wire 52, a slit 61 is formed in the terminal portion of each covered electric wire 52, and the end of each covered electric wire 52 is peeled. It must be in a form that can be fed to a terminal crimping device (press device).

Therefore, as shown in FIG.
By forming a slit 61 between the lines 58, each line 5
It is required that the distance D between 2, 58 can be changed.

[0008]

However, in the shielded flat electric wire 50 as described above, each wire 52, 5
Since the interval between the eight portions is very small, when the slit 61 is formed, the overlapping area in the overlapping portion is further reduced,
As shown in FIG. 13, the adhesive strength at the portion where the slit 61 is provided is reduced. For this reason, peeling is likely to occur in the overlapping portion of the metal foils 62a and 62b, and the shielding performance is reduced,
There is a problem that a reflection phenomenon (a phenomenon in which a signal transmitted earlier becomes a noise and affects a signal transmitted later) is caused.

Therefore, it is conceivable to increase the adhesive strength between the metal foils 62a and 62b by using an adhesive having a strong adhesive force. This adhesive is applied to the entire surfaces of the metal foils 62a and 62b facing each other. Therefore, if the adhesive strength is increased, the adhesive strength between the covered electric wire 52 and the metal foils 62a and 62b is also increased. As a result, it becomes difficult to perform the above-described peeling. Further, it is extremely difficult and practical to use an adhesive to be applied to a joint portion between metal foils and another portion, or to apply an adhesive only to a joint portion.

On the other hand, it is conceivable to perform special processing such as perforation to increase the bonding strength between the metal foils 62a and 62b, but this is not preferable because the number of processing steps increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an inexpensive shielded flat wire capable of achieving both the bonding strength between shields and the ease of peeling of a portion to be peeled, and an inexpensive shielded flat wire. It is an object to provide a manufacturing method.

[0012]

In order to solve the above-mentioned problems, the present invention provides a plurality of covered electric wires arranged in parallel on the same plane and a state in which the covered electric wires are sandwiched in a direction perpendicular to the plane. In a shielded flat wire having a shield made of a pair of metal foils that are bonded to each other with an adhesive between the covered wires, an uneven surface is formed on the outer peripheral surface of the covered wire so as to reduce a contact area with the shield. It is a shielded flat electric wire characterized by the following.

According to the present invention, undulations are formed in the covered electric wire, and the contact area with the shield is reduced, so that the adhesive force between the covered electric wire and the shield is weaker than the adhesive force between the metal foils constituting the shield. . As a result, in forming the shield by polymerizing the metal foils, the shield can be easily peeled off from the insulator of the coated electric wire during the terminal treatment of the coated electric wire, even if an adhesive having high adhesive strength is employed. Can be. On the other hand, the selection range of the adhesive for bonding the metal foils to each other is widened, and it is possible to select an adhesive having as strong an adhesive force as possible. In addition, even when a slit is formed between the covered electric wires, the overlapped portion of the metal foil at the portion where the slit is formed is less likely to peel. In the present invention, "metal foil" is not limited to pure metal foil,
It is also meant to include various types of coatings such as metal foils for reinforcement. The “outer sheath” may be formed by laminating films or sheets, or may be formed by molding. The “undulations” are preferably formed integrally with the insulator. However, the undulations may be formed by another member.

In particular, the undulation preferably has peaks and valleys in the radial direction of the covered electric wire and extends substantially uniformly in the longitudinal direction.

With this configuration, the covered electric wire comes into contact with the surface of the metal foil constituting the shield only by the top of the rib, so that the contact area can be further reduced. In addition, production can be easily performed by, for example, extrusion molding.

It is preferable that the undulation of the covered electric wire is formed by a plurality of ribs extending in the longitudinal direction and provided intermittently in the circumferential direction.

Even in this case, the contact area can be reduced along the longitudinal direction of the electric wire, and the adhesive strength can be reduced. Rib formation methods include extrusion molding,
It is possible to form irregular profiles using rolls.
When the rib is formed by a roll, it is not always necessary to make the height in the radial direction uniform.

Further, the height of the rib is one of the insulation thickness.
It is preferable to set the value from / 2 to 2/3.

In this way, it is possible to set an optimum height at which the adhesive strength can be reduced as much as possible without impairing the dielectric breakdown strength.

Further, it is preferable that the rib has a ridge formed on the top.

In this case, since the top of the rib is joined to the shield in a substantially line contact state, the adhesive strength can be further reduced.

It is preferable that a drain wire electrically connected to the shield is provided along with the coated electric wire between the metal foils constituting the shield.

In this case, the shield portion can be easily wired by the drain wire. In this case, it is possible to form a slit between the drain wire and the coated electric wire, and it is possible to maintain a high peeling strength of the shield (metal foils) in the slit.

Further, it is preferable that the metal foil is bonded with a vinyl chloride-based adhesive.

In this way, the bonding strength between the metal foils is increased, so that even when a slit is formed, good bonding strength can be maintained.

According to another aspect of the present invention, there are provided a plurality of insulated wires arranged in parallel on the same plane, and a pair of metal bonded by an adhesive while sandwiching the insulated wires in front and back directions orthogonal to the plane. In a method of manufacturing a shielded flat wire for manufacturing a shielded flat wire having a shield made of a foil, a relief is formed in advance on an insulator surface of the coated wire, and then the coated wires are arranged in parallel. The method includes sandwiching and covering the covered electric wire with a pair of metal foils provided with an adhesive on a surface facing the electric wire, and bonding the metal foils between the covered electric wires with the adhesive. This is a method for manufacturing a shielded flat electric wire, which is a feature.

According to the present invention, after the undulation is formed on the insulator surface of the covered electric wire in advance, the covering with the metal foil is performed. Therefore, even if the adhesive for bonding the metal foils is applied over the entire surface of the metal foil, The adhesive strength between the foil and the covered electric wire can be reduced. Therefore, it is possible to locally change the adhesive strength without performing partial application,
It is possible to reduce the manufacturing cost.

[0028]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective sectional view showing a shielded flat wire 10 according to the present invention, and FIG. 2 is a partial sectional view of FIG. 1 for explaining a shield structure of the shielded flat wire. The shielded flat electric wire 10 shown in these figures includes a plurality of covered electric wires 12 in which a conductor 14 is covered with an insulator 16 and a drain wire 18 composed of only a conductor, and the covered electric wire 12 and the drain wire 18 are identical to each other. In this configuration, the shield 20 and the outer sheath 24 are arranged in parallel on a plane, and are integrally formed therearound. In the illustrated example, a slit S is formed between each of the wires 12 and 18 in order to connect the shielded flat electric wire 10 to a crimp terminal accommodated in a pole of a crimp connector (not shown). The end portion of each covered electric wire 12 is subjected to a skinning process, and a part of the outer sheath 24 and the shield 20 is cut off, so that the covered electric wire 1 is cut off.
The second insulator 16 is exposed. Further, the terminal portions of the insulators 16 are subjected to a peeling process, so that the conductors 14 are exposed.

The shield 20 is formed by bonding a pair of conductive metal foils 22a and 22b with an adhesive between the wires 12 and 18. As the metal foils 22a and 22b, pure metal foils such as copper foils or those obtained by forming a reinforcing layer such as a resin on these metal foils are used. Further, as the above-mentioned adhesive, a vinyl acetate-based adhesive is preferably used.

Further, an outer sheath 24 covering the outer periphery of the shield 20 is fixed with a polyethylene terephthalate-based adhesive via a reinforcing layer (not shown) made of polyethylene terephthalate.

Referring to FIG. 2, the insulator 16 of the covered electric wire 12 according to the present embodiment has a large number of ribs 16a on the outer peripheral surface. The rib 16a forms an undulation capable of reducing the contact area with the shield 20 in the illustrated embodiment, and its height (a radial dimension from the deepest part of the valley to the top of the mountain) H is: It is preferable that the thickness is 1/2 to 2/3 of the insulation thickness T. For example, if the insulation thickness T is 0.2 mm to 0.3
In the case of mm, the height H is set from 0.1 mm to 0.2 mm. As a result, the height of the rib 16a is set to an optimum height that can reduce the bonding strength as much as possible without impairing the dielectric breakdown strength.

According to the shielded flat electric wire 10 as described above, the insulator 16 of the covered electric wire 12 has undulations (ribs 16).
Since a) is provided, the adhesive force between the covered electric wire 12 and the metal foils 22a and 22b forming the shield 20 is weaker than the adhesive force between the metal foils 22a and 22b forming the shield 20.

Therefore, in the illustrated embodiment,
When the outer sheath 24 and the terminal portion of the shield 20 are cut off, the work of peeling the metal foil forming the shield 20 becomes easy. On the other hand, a metal foil 22a constituting the shield 20;
Since the adhesive force between the 22b is set strong, it is possible to suitably form the slit S for branching the terminal,
Strong peel resistance can be obtained. As a result, it is possible to effectively prevent a decrease in shielding performance due to peeling of the metal foils 22a and 22b.

Next, a method of manufacturing the shield flat electric wire 10 will be described with reference to FIGS. FIG.
FIG. 4 is a perspective view schematically showing an extrusion molding die when manufacturing a covered electric wire, and FIG. 4 is a schematic sectional view showing a use state of the molding die of FIG. 3. FIG. 5 is a perspective view showing a manufacturing process of a laminate to be a material of the shield flat electric wire.

First, referring to FIG. 3 to FIG.
At the time of manufacturing 2, the covered wire 12 is extruded using a forming die 30 for forming undulations on the outer peripheral surface. The forming die 30 includes a sleeve 32 having a discharge port 31 corresponding to the outer shape of the insulator 16 of the covered electric wire 12, and a large-diameter sleeve 33 formed concentrically on the sleeve 32. The inner peripheral surface of the large-diameter sleeve 33 forms a tapered surface 33 a having a smaller diameter as approaching the sleeve 32 and a cylindrical surface 33 b that communicates with the outside and the discharge port 31 of the sleeve 32 continuously. This forming die 30
Is used together with the cylindrical point 34.
This point 34 is a cylindrical body having a tapered guide surface 35 whose tip becomes thinner. At the time of molding, the guide surface 35 is concentric with the large-diameter sleeve 33 in the large-diameter sleeve 32 of the molding die 30. Fixed in the installed state,
At the time of molding, the guide surface 35 plays a role of guiding the molten resin as a material of the insulator 16 to the discharge port 31. On the other hand, the inner peripheral surface 36 of the point 34 is opened concentrically with respect to the discharge port 31, and is configured to play a role of guiding the conductor 14 fed by a guide roller (not shown) to the discharge port 31. .

By performing extrusion molding using these molding dies 30 and points 34, FIG.
The coated electric wire 12 shown in (a) can be manufactured.

Next, referring to FIGS. 5 (a) and 5 (b), the plurality of manufactured covered electric wires 12 and the drain wire 18 are fed out by a roller in a parallel state, and the parallel body is made of a metal foil 22.
a, 22b, and both metal foils 22a, 22b are adhered with vinyl chloride vinyl acetate resin. As a result, FIG.
As shown in (a), each of the lines 12, 18 is introduced between a pair of pressure rollers (not shown) in a state of being arranged in parallel on the same plane, and the metal foils 22a, 22b are perpendicular to the plane by the metal foils 22a, 22b. It is sandwiched in the direction and covered. By this step, as shown in FIG.
A flat laminate S1 in which the components 2 and 18 are integrated is formed.

In the above coating step, each of the metal foils 22a,
It is preferable that a vinyl chloride-based resin be applied to the entire bonding surface of 22b in advance. Even if each of the wires 12 and 18 is covered with the metal foils 22a and 22b in this manner, the ribs 16a
Since the undulations are formed, the adhesive strength between the insulator 16 and the metal foils 22a and 22b is reduced by the metal foils 22a and 22b.
b becomes weaker than the adhesive strength between them.

Next, in an outer sheath forming step, an insulating sheet is laminated using the apparatus shown in FIG. FIG.
It is the schematic which shows the example of a manufacturing process of the outer sheath 24.

The laminator 80 shown in FIG. 6 includes supply reels 83 and 84 for supplying insulating tapes 81 and 82 attached to both surfaces of the above-mentioned laminated body S1, and peeling off on the back of the supplied insulating tapes 81 and 82. Peeling tape reels 87 and 88 for supplying tapes 85 and 86, and the insulating tapes 81 and 8
2 and the release tapes 85 and 86 are sandwiched in this order on both the front and back sides of the laminate S1 to heat three heating roller pairs 88.
A winding machine 89 that winds the release tapes 85 and 86 after heating; a slitter 90 that trims both sides of the stacked body S2 formed by the heating roller pair 88;
And a product winding machine 91 that winds the shielded flat electric wire 10 having the outer sheath 24 formed thereon as a product. In FIG. 6, a guide roller pair 92 is provided at an appropriate position on the transport path on which the laminate S1 and the shield flat electric wire 10 are transported. Further, a winding section 93 for winding the cut chips is provided downstream of the slitter 90, and the product winding machine 9 is provided.
A take-off capstan 94 is disposed between the slit cap 1 and the slitter 90. Further, 95 is a start waste pinch roller, 96 is a traverse, and 97 is a pinch roller.

According to this apparatus, the insulating tape 8 is provided on both sides of the laminate S1 in which the shields 20 cover the respective wires 12, 18.
After the sheets 1 and 82 are laminated and laminated by the heating roller pair 88, they are cut into a fixed width by the slitter 90. Thus, the shield flat electric wire 10 is formed and wound around the product winding machine 91.

Next, in the slit forming step and the peeling step, the apparatus 100 shown in FIG. 7 is used. FIG. 7 is a schematic side view of a processing apparatus that can be employed in the present invention. 8 and 9 are perspective views of the laminate processed by the manufacturing process shown in FIG.

The apparatus 100 shown in FIG. 1 includes an electric wire feeding reel 101, an accumulator 102, a straightener 103, and a slitter 10 in order from the upstream side of a predetermined transport path ph.
4. The measuring cutter 105 is provided in this order. And
The shield flat electric wire 10 wound around the electric wire feeding reel 101 is supplied to the straightener 103 via the accumulator 102, and a slit S is formed at a terminal portion by the slitter 104 in a state where the winding habit is removed ( FIG. 8B). Further, the entire length is measured by the measuring cutter 105, and the terminal portion of the outer sheath 24 is cut to a desired length in a state where the covered wire 12 is partially removed, and the shield flat shown in FIG. Electric wire 1
0 is completed.

A bundler 106 is arranged downstream of the scale cutter 105, and the shielded flat electric wire 10 cut and scaled is conveyed and collected by a conveyor (not shown) of the bundler 106. Can be

Next, referring to FIG. 9, the terminal portion of the shielded flat electric wire 10 manufactured as described above has the terminal portion of the outer sheath 24 intact as shown in FIG. Move to the pressure welding process or FIG. 9 (b)
As shown in (5), the process proceeds to the crimping step through the stripping of the covered electric wire 12 and the stripping of the terminal portion of the outer sheath 24 of the drain wire 18. In the peeling step, as described above, the covered electric wire 12 and the metal foil 22
Since the adhesive strength between the metal foils 22a and 22b constituting the shield 20 is weaker than the adhesive strength between the metal foils 22a and 22b constituting the shield 20, the skinning can be performed very smoothly. In addition, it is possible to maintain a relatively firm adhesive force at the portion where the slit S is formed.

As described above, in this embodiment, since the adhesive force between the covered electric wire 12 and the shield 20 is weaker than the adhesive force between the metal foils 22a and 22b constituting the shield 20, the shield 20 can be easily covered. Insulator 1 for electric wire 12
6, while the adhesive strength between the metal foils 22a and 22b constituting the shield 20 can be strongly maintained, so that the overlapped portions of the metal foils 22a and 22b at the slit S forming portions are less likely to be peeled off. Become. In addition, a step for reinforcing the adhesive force between the metal foils 22a and 22b is not required, so that an increase in cost can be suppressed.

In addition, in the above-described manufacturing method, after the ribs 16a are formed on the surface of the insulator 16 of the covered electric wire 12 in advance, the covering with the metal foils 22a and 22b is performed, so that the metal foils 22a and 22b are bonded to each other. Adhesive to the metal foil 22a,
22b, the metal foil 22
a, 22b and the coated wire 12 can be weakened in adhesive strength. Therefore, it is possible to locally change the adhesive strength without performing partial application, and it is possible to reduce the manufacturing cost.

Therefore, according to the present embodiment, both the adhesive strength of the shield and the easiness of peeling of the part to be peeled can be achieved at low cost.

The above embodiments are merely preferred specific examples of the present invention, and the present invention is not limited to the above embodiments.

For example, as an example of undulation, as shown in FIG. 10, the number of ribs 16a can be appropriately changed. In addition, as shown in FIG.
A ridge may be formed on 6b so that the top 16b of the rib 16a is joined to the shield in a substantially line contact state. In this case, since the contact area is as small as possible, the shield is more easily peeled off from the covered electric wire 12.

Further, the laminate S1 (see FIG. 5 (b)) is passed through a cavity (a mold passage for forming an outer sheath) formed in an extruder (not shown), and the above-described cavity is formed in the cavity, for example. Supply sheath material made of thermoplastic resin such as polyethylene terephthalate,
By pulling out the sheath material while adhering it around the laminate S1, an outer sheath 2 is formed around the laminate S1.
4 can also be formed.

It goes without saying that various modifications can be made within the scope of the claims of the present invention.

[0054]

As described above, according to the present invention, since the adhesive force between the covered electric wire and the shield is weaker than the adhesive force between the metal foils constituting the shield, the shield can be easily insulated from the covered electric wire. While it can be peeled off from the body, the adhesive force between the metal foils constituting the shield can be kept strong, so that the overlapped portion of the metal foil at the slit forming portion is less likely to be peeled off. In addition, a step for reinforcing the adhesive force between the metal foils is not required, so that an increase in cost can be suppressed.

Therefore, according to the present invention, it is possible to obtain an inexpensive shielded flat wire that can achieve both the bonding strength between shields and the ease of peeling of a portion to be peeled.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a shielded flat electric wire according to the present invention.

FIG. 2 is a partial cross-sectional view of FIG. 1 illustrating a shield structure of the shielded flat electric wire.

FIG. 3 is a perspective view schematically showing an extrusion die for producing a covered electric wire.

FIG. 4 is a schematic sectional view showing a use state of the molding die of FIG. 3;

FIG. 5 is a perspective view showing a manufacturing process of a laminated body to be a material of the shielded flat electric wire.

FIG. 6 is a schematic view showing an example of a manufacturing process of an outer sheath.

FIG. 7 is a schematic side view of a processing apparatus that can be employed in the present invention.

FIG. 8 is a perspective view of a laminate processed by the manufacturing process shown in FIG. 7;

FIG. 9 is a perspective view of a laminate processed by the manufacturing process shown in FIG. 7;

FIG. 10 is a schematic cross-sectional view of a covered electric wire according to another embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view of a covered electric wire according to still another embodiment of the present invention.

FIG. 12 is a sectional perspective view showing the structure of a conventional shielded flat electric wire.

13 is a perspective view showing a state where a branch slit is formed in the shielded flat electric wire of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shield flat electric wire 12 Insulated electric wire 14 Conductor 16 Insulator 16a Rib 18 Drain wire 24 Outer sheath S Slit

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Atsushi Tanaka 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Harness Research Institute, Inc. (reference) 5G309 JA01 LA17 LA24 5G311 CB02 CC02 CD03 CD07 CE04 5G313 AB05 AC03 AC11 AD02 AE08

Claims (8)

[Claims] 1. A plurality of covered electric wires arranged in parallel on the same plane, and a pair of covered electric wires bonded to each other by an adhesive while sandwiching the covered electric wires in front and back directions orthogonal to the plane. A shielded flat electric wire comprising: a shield made of a metal foil according to any one of claims 1 to 3, wherein an undulation capable of reducing a contact area with the shield is formed on an outer peripheral surface of the covered electric wire. 2. The shielded flat electric wire according to claim 1, wherein said undulations have peaks and valleys in a radial direction of the covered electric wire and extend substantially uniformly in a longitudinal direction. Flat wires. 3. The shielded flat wire according to claim 1, wherein the undulation of the covered wire is formed by a plurality of ribs extending along a longitudinal direction and provided intermittently in a circumferential direction. A shielded flat electric wire, characterized in that: 4. The shielded flat electric wire according to claim 3, wherein the height of the rib is か ら to 2 of the insulation thickness.
Shielded flat electric wire, characterized in that it is set to / 3. 5. The shielded flat electric wire according to claim 3, wherein the rib has a ridge line formed at a top portion. 6. The shielded flat electric wire according to claim 1, wherein a drain wire electrically connected to the shield is arranged along with the coated electric wire between metal foils constituting the shield. A shielded flat electric wire characterized by being provided. 7. The shielded flat electric wire according to claim 1, wherein the metal foil is bonded with a vinyl chloride-based adhesive. 8. A plurality of insulated wires arranged in parallel on the same plane, and a shield made of a pair of metal foils bonded by an adhesive while sandwiching the insulated wires in front and back directions orthogonal to the plane. In the method for manufacturing a shielded flat wire provided with a shielded flat wire, in the form of undulations in advance on the insulator surface of the coated wire, and then arrange the coated wires in parallel, on the surface facing these coated wires A shielded flat wire comprising a step of sandwiching and covering the covered wire with a pair of metal foils provided with an adhesive, and bonding the metal foils between the covered wires with the adhesive. Manufacturing method.