JP5859880B2 - How to remove coating material from flat cable - Google Patents

Description

  The present invention relates to a flat cable covering material removal method called a flat cable, and more particularly to a processing method for removing a flat cable covering material to expose a strip conductor.

  A flat cable (flat cable) is a belt-like body formed by laminating a plurality of strip-like conductors arranged in parallel with a pair of insulating films (coating materials) through an adhesive layer and laminating them. When connecting a flat cable to an electric circuit, the strip conductor of the flat cable is superimposed on the connecting conductor that is connected to the electric circuit, and both conductors are electrically and mechanically welded (spot welding, etc.). It is common to connect them.

  For example, in a rotary connector incorporated in a steering apparatus of an automobile and used as an electrical connection means for an air bag system or the like, a flat cable is wound in an annular space defined between a movable side housing and a fixed side housing. It is housed in a rotating state, and the strip conductors at both ends of the flat cable are welded and joined to pin terminals (connecting conductors) of lead blocks (connector members) held in the respective housings. That is, in the rotary connector, the inner end portion of the flat cable housed in the annular space is connected to the lead block held by the movable housing that rotates integrally with the handle (steering wheel), and The outer end of the flat cable is connected to another lead block held by a stationary housing installed on a steering column or the like.

  By the way, in order to weld and bond the strip-shaped conductor of the flat cable covered with the insulating film to the connection conductor such as the pin terminal, it is necessary to expose a part of the strip-shaped conductor in advance. Therefore, a flat cable in which the strip conductor is not exposed, that is, a flat cable in which the strip conductor is covered with a pair of insulating films having no openings, is irradiated with laser light to locally cover the insulating film. There is known a covering material removing method in which a part of a strip-shaped conductor is exposed to a desired position by removing the conductive material. In this way, if the technique of locally evaporating the insulation film of the flat cable with the heat of the laser beam to expose the strip conductors, the exposure position of the strip conductors can be easily adjusted according to the number and pitch of the connecting conductors. Since it can be changed, the cost of the flat cable can be reduced. In addition, in this covering material removing method, the insulating film is locally removed by laser light irradiation, so that it is easy to expose the strip conductor at a desired position of the flat cable with high accuracy.

  As a conventional technique for removing the insulating film by laser light irradiation, laser light is irradiated from one side of the flat cable to a desired position of the strip-shaped conductor, and after the perforation is formed in the insulating film on this one side, A processing method has been proposed in which the belt-shaped conductor in the perforation is continuously irradiated with laser light and heated, whereby the insulating film on the other surface side is turned up locally by the heat, and the portion is cut and removed. (For example, refer to Patent Document 1). According to this method, an opening (turned up portion) can be formed in the insulating film covering both the front and back surfaces of the strip-shaped conductor only by irradiating one surface of the flat cable with laser light. Therefore, there is no need to irradiate the other side of the flat cable with laser light.

  As another conventional technique, first, one side of the flat cable is irradiated with a laser beam, and the insulating film on one side is locally removed, and then the corresponding area on the other side of the flat cable is applied. There has been proposed a method of locally removing the insulating film and the like on the other surface by irradiating laser light.

JP-A-8-47132

  Since the conventional covering material removal method described in Patent Document 1 only needs to irradiate the laser beam to one surface of the flat cable, the laser beam irradiation time can be shortened. Each part on both sides of the insulating film that has been turned up after irradiation must be cut. Therefore, this cutting operation is complicated, and it is difficult to shorten the processing time required for removing the covering material.

  On the other hand, in the case of the latter covering material removing method, in which the insulating film is removed by sequentially irradiating one side surface and the other side surface of the flat cable, the one side surface is irradiated with the laser beam. The insulating film on the other side laminated on the strip conductor is softened by the heat and easily deforms into a bowl-like shape. There is a problem that it becomes difficult to focus the laser beam on the unevenness, and it is difficult to remove the insulating film cleanly. Note that if the power of the laser beam irradiated on one side is lowered, the insulating film on the other side is less likely to be cocoon-shaped, but this will increase the laser beam irradiation time and reduce the processing efficiency. Since a large amount of residue made of carbide or the like of the adhesive layer adheres on the strip conductor, it is not preferable to connect with other conductors because the electrical connectivity deteriorates due to the influence of these residues and the reliability decreases.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to efficiently remove a desired region of an insulating film covering a strip-shaped conductor and to electrically connect with other conductors. It is an object of the present invention to provide a method for removing a covering material of a flat cable that can improve the quality of the cable.

In order to achieve the above object, according to the present invention, a surface of one side of a plurality of strip-shaped conductors arranged in parallel is covered with a first insulating film, and the other side of the plurality of strip-shaped conductors In order to expose the plurality of strip-shaped conductors in a desired region, a first cable and a second insulation film are exposed to a flat cable whose surface is covered with a second insulating film. In the flat cable covering material removing method for removing the film, first, a cooling medium is directly sprayed on the second insulating film in the desired region on the other surface of the flat cable to thereby apply the second insulating film. While cooling, the first insulating film in the desired area is irradiated with laser light on one side of the flat cable, and then the other side of the flat cable is in the desired area. The second insulation film The laser light was to be irradiated.

According to such a configuration, the portion of the first insulating film that covers the strip-shaped conductor on the surface on one side and the first and second insulating films laminated without the strip-shaped conductor interposed therebetween are heated by laser light irradiation. The portion of the second insulating film that is removed and covers the strip conductor on the other side surface has a direct cooling effect by spraying the cooling medium and a heat dissipation effect in which heat is conducted and diffused through the strip conductor. Since it is not heated excessively and the state before the laser irradiation is maintained as it is without being turned or deformed, the focal point of the laser beam can be easily concentrated on the second insulating film. Therefore, the desired area | region of the insulating film which coat | covers a strip | belt-shaped conductor can be removed efficiently, and electrical connection property with another conductor can be made favorable. Further, since the power of the laser beam can be set high, the irradiation time of the laser beam can be further shortened, and the manufacturing cost can be greatly reduced. It should be noted that the above-described effects can also be obtained with a configuration in which the first and second adhesive layers are interposed between the first and second insulating films of the flat cable and the strip conductor. That is, when irradiating laser light in a desired area on one side of the flat cable, if the second insulating film on the other side is cooled in an area corresponding to the desired area, A portion of the first insulating film and the first adhesive layer covering the band-shaped conductor, and the first insulating film, the first adhesive layer, the second insulating film, and the second adhesion laminated without the band-shaped conductor interposed therebetween. The layer is heated and removed by irradiation with laser light. On the other hand, the second insulating film and the second adhesive layer that cover the strip-shaped conductor on the other side surface are suppressed from being heated by the laser light irradiation and maintain the state before the laser irradiation, and thus are the same as described above. The effect is obtained.

In the coating material removing process, the cooling medium is a gas (e.g. air), it can be constructed at low cost cooling means. Further, depending on the laser light irradiation conditions, the configuration of the flat cable, etc., it is possible to easily select and appropriately cool the amount of gas sprayed per unit time, the speed, and the like.

  In the covering material removing method described above, it is preferable that a plurality of strip-shaped conductors are individually exposed by irradiating a plurality of spaced apart portions of the flat cable with laser light. According to this configuration, it is possible to prevent a short circuit between the strip conductors when the connecting conductor is connected to the strip conductor exposed at each perforated portion.

  Further, in the above-described covering material removal method, when the flat cable is irradiated with laser light in a direction intersecting with the direction in which the strip conductor extends, a plurality of strip conductors are exposed collectively. The number of work processes can be reduced and the manufacturing time can be further shortened.

According to the covering material removing method of the present invention, when laser light is irradiated in a desired region on one side of the flat cable , the cooling medium is directly sprayed on the second insulating film on the other side. Since the 2nd insulating film is cooled in the area | region corresponding to the said desired area | region, it can suppress that the 2nd insulating film of the part which covers the strip | belt-shaped conductor in the surface of the other side is heated too much. Therefore, the portion of the first insulating film that covers the strip conductor on the one surface and the first and second insulating films laminated without the strip conductor are heated and removed by laser light irradiation. The second insulating film that covers the strip-shaped conductor on the other side surface remains without being removed, and is not turned up or deformed into a bowl shape, and is in a state before laser irradiation. Is maintained and the thickness is kept uniform. Therefore, after that, the second insulating film on the other side remaining without being removed can be cleanly removed by laser light irradiation, so that the insulating film in the desired region of the insulating film covering the strip conductor is formed. It can be removed efficiently, and electrical connectivity with other conductors can be improved. Further, since the power of the laser beam to be irradiated can be set high, the irradiation time of the laser beam can be further shortened, and the manufacturing cost can be greatly reduced.

It is sectional drawing of the flat cable which concerns on the example of embodiment of this invention. It is explanatory drawing which shows the specific example of the coating material removal method of this flat cable. It is a perspective view which shows the connection end part of the flat cable which exposed the strip | belt-shaped conductor by the coating | covering material removal method shown in FIG. It is a perspective view which shows the connector member connected with the connection end part of the flat cable shown in FIG. It is a top view which shows the connection end part of the flat cable which exposed the strip | belt-shaped conductor with the method similar to the coating | covering material removal method shown in FIG. It is a typical expanded sectional view of the perforated part shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1A, a flat cable (flat cable) 1 according to the present embodiment has a first insulating film on one side of each strip-like conductor 2 via a first adhesive layer 5. 3, and the other surface of each strip conductor 2 is covered with a second insulating film 4 via a second adhesive layer 6. Further, in the flat cable 1, as shown in FIG. 1 (b), the portions without the respective strip-shaped conductors 2 are arranged without the strip-shaped conductor 2, the first insulating film 3, the first adhesive layer 5, the second The adhesive layer 6 and the second insulating film 4 are directly laminated. Each strip-like conductor 2 is made of a copper foil having a thickness of about 30 μm, and the first and second insulating films 3 and 4 are both made of PET (polyethylene terephthalate) having a thickness of about 50 μm. The first and second adhesive layers 5 and 6 are both made of a thermoplastic polyester having a thickness of about 30 μm. However, the strip conductor 2, the first and second insulating films 3 and 4, and the first and second adhesive layers 5 and 6 may be formed of a material different from that of the present embodiment, and the thickness of each may be appropriately determined. Selectable.

  This flat cable 1 is used by welding and joining a strip-shaped conductor 2 exposed at both ends in a longitudinal direction to a pin terminal 12 which is a connecting conductor of a connector member 10 (see FIG. 4). . That is, as shown in FIG. 3, a plurality of perforations 7 for individually exposing the respective strip conductors 2 are provided at the end of the flat cable 1. As will be described later, these perforated portions 7 sequentially irradiate laser light L on one side and the other side of the end portion of the flat cable 1, so that the first and second insulating films 3 that are covering materials are used. , 4 and the first and second adhesive layers 5 and 6 are removed. Further, the end portion of the flat cable 1 is provided with positioning holes 8 at a plurality of locations that do not overlap with the strip conductor 2.

  Next, a processing procedure for forming the perforated part 7 in the flat cable 1 will be described. First, as shown in FIG. 2, laser is generated at a plurality of locations (a plurality of small regions 21 spaced apart from each other) corresponding to the perforated portion 7 as a desired region on one side of the end portion of the flat cable 1. When irradiating the laser beam L of the vessel 22, air is blown onto the second insulating film 4 in the region corresponding to the small region 21 to cool the other surface of the end portion. By carrying out like this, in the small area | region 21 irradiated with the laser beam L, the 1st insulating film 3 and 1st contact bonding layer of the part which covers the upper surface of the strip | belt-shaped conductor 2 in the surface of the one side shown to Fig.1 (a). 5 and the first insulating film 3, the first adhesive layer 5, the second adhesive layer 6, and the second insulating film 4 laminated without the strip-shaped conductor 2 shown in FIG. It is heated and removed by irradiation with the laser beam L. At that time, the second insulating film 4 and the second adhesive layer 6 that cover the lower surface of the strip-shaped conductor 2 on the other surface shown in FIG. 1A irradiate one surface of the flat cable 1. Even if heated by the heat of the laser beam L, it is not removed, and the state before irradiation of the laser beam L is maintained. That is, on the other surface, the second adhesive layer 6 and the second insulating film 4 are formed by the direct cooling effect by the cooling and the heat dissipation effect in which heat is conducted and diffused through the strip conductor 2. It is not heated excessively and remains without being removed, of course, without being turned over or deformed into a bowl shape, the state before irradiation with the laser light L is maintained and the thickness is kept uniform. .

In this embodiment, when irradiating the laser light L to the surface on one side of the connection end of the flat cable 1, the laser light L is moved while irradiating a predetermined region narrower than the small region 21. Thus, the positioning hole 8 is opened in the first insulating film 3. In this embodiment, a cooling device (air cooling device) that discharges air A from the nozzle 23 is used. However, a gas other than air (for example, a gas containing nitrogen or water vapor) or a liquid such as water is used. The cooling medium may be sprayed onto the second insulating film 4 to cool it.

  After that, by irradiating the laser beam L from the laser generator 24 to the region corresponding to the small region 21 on the other surface of the end portion of the flat cable 1, it remains without being removed in the small region 21. The portions of the second insulating film 4 and the second adhesive layer 6 that cover the strip conductor 2 are removed. In this case, the second insulating film 4 and the second adhesive layer 6 are not turned over or deformed in a bowl shape, and the focal point of the laser light L can be easily concentrated on the second insulating film 4. The first insulating film and the second insulating film can be efficiently removed, and electrical connection with other conductors can be improved. Further, since the power of the laser beam can be set high, the irradiation time of the laser beam can be further shortened, and the manufacturing cost can be greatly reduced. As shown in FIG. 6, the perforated portion 7 formed by such a method is inclined so that the inner wall 7a of the perforated portion 7 gradually expands outward from the bottom (band-like conductor 2) of the perforated portion 7. It forms a surface, and a boundary portion between the inclined surface and the surface of each of the insulating films 3 and 4 forms a protruding portion 7b that protrudes outward. Here, the inclined surface 7a has a slightly curved cross-sectional shape. In FIG. 6, the first and second insulating films 3 and 4 and the first and second adhesive layers 5 and 6 are not distinguished from each other, and reference numeral 3 denotes an insulating layer on one side (upper side in the drawing) of the strip-shaped conductor 3. The other side (the lower side in the figure) is indicated with a reference numeral 4 and is shown in a simplified manner. In addition, the perforated part formed in the flat cable manufactured by the heat seal method to be described later also has a form as shown in FIG.

  Processing conditions such as the type, power, and number of irradiations of the laser beam L can be selected as appropriate. In this embodiment, for example, a CO2 laser (output 20 W) having a wavelength of 9.3 μm is moved at a moving speed of 350˜ The perforated part 7 is formed by irradiating a plurality of times at 2000 (mm / second). It is also possible to perform laser processing on one side and the other side of the flat cable 1 using separate laser generators.

  The end portion of the flat cable 1 in which the perforated portion 7 is formed in this manner is disposed in the recess 11a of the support member 11 of the connector member 10 shown in FIG. The connector member 10 is electrically and mechanically connected by welding the exposed portion 2a to the pin terminal 12.

  As shown in FIG. 4, the connector member 10 is obtained by press-fitting and fixing a plurality of pin terminals 12 to an insulating support member 11. However, the connector member 10 may have a structure in which each pin terminal 12 is integrated with the support member 11 by insert molding or the like. On the bottom plate portion of the support member 11, positioning protrusions 13 protrude from a plurality of locations, and exposure holes 14 are opened at locations corresponding to the perforated portions 7 of the flat cable 1. By inserting and crimping each positioning protrusion 13 into the corresponding positioning hole 8 of the flat cable 1, the end portion of the flat cable 1 is positioned and fixed in the recess 11a of the support member 11, and each perforated portion is fixed. 7 is arranged directly above the corresponding exposed hole 14. The pin terminal 12 extends right above the exposed hole portion 14, and an electrode (not shown) is exposed when the strip-shaped conductor 2 (exposed portion 2 a) in the perforated portion 7 and the pin terminal 12 are spot welded. Arranged in the hole 14. The positioning protrusion 13 of the support member 11 inserted into the positioning hole 8 of the flat cable 1 prevents the external force from directly acting on the welded portion, stabilizes the electrical connection with other conductors, and is reliable. It also fulfills the function of enhancing

  In this embodiment, the flat cable 1 is housed in a wound state in an annular space defined between a movable housing and a fixed housing of a rotary connector (not shown). Is a lead block attached to the movable housing or the stationary housing. This rotary connector is incorporated in a steering device of an automobile and used as an electrical connection means such as an air bag system. One end (inner end) of the flat cable 1 is a handle (steering wheel). The other end (outer end) of the flat cable 1 is connected to a lead block held in a movable side housing that rotates integrally with the other side, and is held in a fixed side housing installed in a steering column or the like. Connected to the lead block.

  As described above, in the present embodiment, when the first insulating film 3 is removed by irradiating the surface of one side of the flat cable 1 with the laser beam, the second insulating surface of the other side is removed. Since the film 4 is cooled in the region corresponding to the irradiation region, the first insulating film 3 covering the strip-shaped conductor 2 on the one side surface, and the first and first layers laminated without the strip-shaped conductor 2 interposed therebetween. 2 is heated and removed by irradiation with the laser beam L, and the second insulating film 4 in a portion covering the strip-shaped conductor 2 on the other surface has a direct cooling effect and the strip-shaped conductor. The heat is not excessively heated by the heat dissipation effect that heat is conducted through 2 and diffused, and the state before the laser irradiation is maintained as it is without turning or wrinkle-like deformation. Therefore, the focal point of the laser light L can be easily concentrated on the second insulating film 4 after that, so that it remains without being removed by irradiating the other surface of the flat cable 1 with the laser light. The second insulating film 4 to be removed can be removed. Thus, according to the covering material removal method of the flat cable 1 according to the present embodiment, the perforated portion 7 having the cross-sectional shape as shown in FIG. 6 can be formed, and the insulating film covering the strip conductor 2 can be efficiently used. It can be removed well and electrical connection with other conductors can be improved. Further, since the power of the laser beam can be set high, the irradiation time of the laser beam can be further shortened, and the manufacturing cost can be greatly reduced.

  Note that it is desirable to apply a flat cable manufactured by a heat sealing method as the flat cable 1 because the power of the laser beam L and the number of irradiations can be reduced and the perforated part 7 can be formed in a shorter time. For example, each strip-shaped conductor 2 is a copper foil having a thickness of about 35 μm, the first and second insulating films 3 and 4 are PET (polyethylene terephthalate) having a thickness of 50 μm, and the first and second adhesive layers 5 and 6 are formed. Since the amorphous PET layer having a thickness of about 30 μm is made of amorphous PET, the melting temperature of the amorphous PET layer is lower than the melting temperature of the adhesive layer made of thermoplastic polyester, so the perforated portion 7 is formed in a shorter time. it can. In addition, the flat cable 1 according to the present embodiment has been described with the configuration in which the both sides of the strip conductor 2 are covered with the insulating films 3 and 4 via the adhesive layers 5 and 6. The film 3 and 4 may be configured to cover the strip conductor 2.

  Further, in the present embodiment example, since the second insulating film 4 is cooled by blowing a gas such as air, a desired portion of the second insulating film 4 can be efficiently cooled by an inexpensive cooling means.

  Further, in the present embodiment example, laser light is irradiated to a plurality of spaced apart portions of the flat cable 1, and the first and second insulating films 3, 4 and the first and second insulating films 3 and 4 existing at the plurality of locations are irradiated. By removing the adhesive layers 5 and 6, a plurality of perforated portions 7 for individually exposing the respective strip-shaped conductors 2 are formed. Therefore, pin terminals (for connection) are respectively connected to the strip-shaped conductors 2 exposed to the respective perforated portions 7. When the conductors 12 are connected, it is easy to prevent a short circuit between the strip conductors 2.

  However, as shown in FIG. 5, even if the transverse exposure portion 9 that exposes the group of the strip-shaped conductors 2 at a time is formed by continuously irradiating the laser beam L in the direction orthogonal to the extending direction of the strip-shaped conductor 2. good. 5 is basically the same as the processing procedure for forming the perforated portion 7 in the flat cable 1. In the transverse exposed portion 9, the first and second insulating films 3 and 4 and the first and second adhesive layers 5 and 6 as the covering material are separated along the longitudinal direction of the flat cable 1. Since the strip-shaped conductors 2 are exposed, connecting conductors such as a plurality of pin terminals 12 provided on the support member 11 of the connector member 10 are connected to arbitrary portions of the strip-shaped conductor 2 in the laterally exposed portion 9. It is possible to make it. The cross-exposed portion 9 may be formed orthogonal to the direction in which the strip conductor 2 extends as shown in FIG. 5, but is formed so as to be inclined with respect to the direction in which the strip conductor 2 extends. Also good.

1 Flat cable (flat cable)
2 Strip conductor 3 First insulation film (covering material)
4 Second insulation film (covering material)
DESCRIPTION OF SYMBOLS 5 1st contact bonding layer 6 2nd contact bonding layer 7 Perforated part 8 Positioning hole 9 Cross exposure part 10 Connector member 12 Pin terminal (conductor for connection)
22, 24 Laser generator 23 Nozzle A Air L Laser light

Claims (5)

One side surface of the plurality of strip-shaped conductors arranged in parallel is covered with a first insulating film, and the other side surface of the plurality of strip-shaped conductors is covered with a second insulating film. In a flat cable covering material removing method, the first and second insulating films are removed by irradiating a laser beam to expose the plurality of strip conductors in a desired region with respect to the flat cable. There,
First, while cooling the second insulating film by directly spraying a cooling medium on the second insulating film in the desired area on the other side surface of the flat cable, the one side surface of the flat cable The first insulating film in the desired area is irradiated with laser light, and then the second insulating film in the desired area is irradiated with laser light on the other surface of the flat cable. A method of removing a covering material of a flat cable, characterized in that   2. The covering removal of a flat cable according to claim 1, wherein an adhesive layer is interposed between the first and second insulating films and the plurality of strip-shaped conductors. Method. 3. The flat cable covering removal method according to claim 1, wherein the cooling medium is a gas .   4. The method according to claim 1, wherein the plurality of strip-shaped conductors are individually exposed by irradiating a plurality of spaced apart portions of the flat cable with laser light. How to remove flat cable sheathing. 4. The flat cable according to claim 1, wherein the flat cable is irradiated with a laser beam in a direction intersecting with a direction in which the strip conductor extends, and the plurality of strip conductors are collectively collected. A method for removing a covering material from a flat cable, wherein the covering material is exposed.

Images