JP5901403B2 - Manufacturing method of wire harness - Google Patents

Description

  The present invention relates to a method of manufacturing a wire harness capable of reliably joining a large number of electric wires.

  A wire harness used for an automobile or the like has a portion where a circuit (for example, a ground wire) of the same system in the branched harness is electrically connected. For this connection, a dedicated joint terminal or a method of connecting the wire conductor portions by processing without using a terminal is used. As a method of joining the wire conductor parts without using such a terminal, for example, ultrasonic joining (for example, Patent Document 1) or resistance welding (for example, Patent Document 2) is performed.

  As one of non-contact processing methods, there is a method by laser welding. Laser welding is characterized by a small heat-affected zone. As an example using such a laser welding method, for example, when laser welding is performed by overlapping the wire conductor portions, a method of pushing the wire conductor portion toward the weld portion using a drive motor, or a separate welding auxiliary material There is a method in which welding is performed while supplying to the welded part (Patent Document 3).

JP 2010-153074 A Japanese Patent Laid-Open No. 9-82375 Japanese Patent No. 3370799

  Ultrasonic bonding uses friction and heat generation between materials caused by ultrasonic vibration to remove the oxide film on the surface and bond the exposed new surfaces, but due to the nature of wire processing, the bonding area is small, etc. There is a problem. Further, since vibration is applied only from one direction, bonding directivity is generated, and the bonding strength in the axial direction different from the ultrasonic wave applying direction is weak. Furthermore, since the object to be joined is processed while being pressurized, the cross-sectional area of the joint is reduced as compared with the base material, and necking occurs. Since the necking portion causes stress concentration, there is a concern that the mechanical strength is reduced. In particular, when the number of joints increases and it is necessary to increase the pressing force, the risk of breaking the strands due to a reduction in the cross-sectional area increases.

  Resistance welding is a method of welding or pressure welding materials using Joule heat. Since resistance welding needs to be sufficiently pressurized at the time of wire processing, there is a risk of wire breakage due to a reduction in the cross-sectional area of the wire, and there is a concern of mechanical strength reduction due to stress concentration in the necking portion. For this reason, it is unsuitable for welding of many electric wires similarly to ultrasonic bonding.

  Moreover, since the method like patent document 3 needs to move an electric wire with a drive motor, an installation becomes complicated. Moreover, since it is necessary to attach an electric wire to a drive motor, there exists a problem that the installation work of an electric wire becomes complicated. In particular, when welding a large number of wires, the system itself becomes complicated. At this time, it is difficult to arrange the electric wires so that laser welding is possible.

  The present invention has been made in view of such problems, and provides a method for manufacturing a wire harness that can be reliably joined even with a large number of electric wires and has a high degree of freedom in the arrangement of electric wires. Objective.

  In order to achieve the above-mentioned object, the first invention is a method of assembling and connecting a plurality of electric wires from which insulating coatings at the end portions have been peeled so that the ends thereof are directed in substantially the same direction. The tip of the electric wire conductor part of the electric wire has a softening point temperature higher than the melting point of the electric wire conductor part or a higher melting point, and is arranged in the electric wire holding part of a jig that holds the tip from the side in the longitudinal direction of the electric wire. In a state where the wires of the wire conductor portion are in contact with each other from the side, the high energy density beam is irradiated from the extending direction of the end surface of the wire conductor portion, and the melting point is lower than the softening point temperature of the jig. The wire harness manufacturing method is characterized in that the tip of the electric wire conductor portion is melted and integrated within the inner wall surface of the electric wire holding portion at a temperature below.

  The jig is preferably made of a material having an absorptance of the high energy density beam of less than 1% with respect to the wavelength of the high energy density beam.

  It is desirable that a cross-sectional area larger than the sum of the wire cross-sectional areas of the wire conductor portions in the non-molten portion is formed in at least a part of the melted integrated portion.

  It is desirable that three or more wires are stacked and assembled without being provided on the same plane.

  You may melt | dissolve the front-end | tip of all the said electric wire conductor parts by irradiating to the end surface of the assembled said electric wire conductor part, moving the condensing position of the said high energy density beam relatively.

  You may melt | dissolve the front-end | tip of all the said electric wire conductor parts by irradiating the said high energy density beam to the approximate center of the end surface of the assembled said electric wire conductor parts.

  The high energy density beam may be a laser, an electron beam, or the like.

  According to the first invention, the tips of the electric wires can be melted and integrated by gathering so that the tips are directed in substantially the same direction and irradiating the high energy density beam from the tip side in the axial direction.

  Moreover, at the time of joining, it can fix so that a front-end | tip may mutually contact by hold | maintaining the front-end | tip of an electric wire with a jig. Therefore, at the time of welding, it is possible to reliably melt and integrate the wire conductor portions according to the shape of the inner surface of the wire holding portion of the jig. That is, the molten integrated part can be regulated to the shape of the electric wire holding part as if the molten metal was cast inside the electric wire holding part of the jig. For this reason, while being able to make the shape of a junction part constant in a desired shape, a junction part side can be made smooth.

  Moreover, since the softening point temperature of the jig is higher than the melting point of the electric wire conductor, the electric wire conductor and the jig are not integrated, and the jig does not melt. Here, the softening point temperature of a jig is the softening point temperature of glass, for example, and refers to a temperature at which fluidity starts to occur in a member. Moreover, it can prevent that a jig | tool fuse | melts by making it the material which has the transparency with respect to the laser wavelength of the said jig | tool.

  Moreover, the cross-sectional area of the electric wire conductor part in a cross section perpendicular | vertical to an axial direction can be made larger than the sum total of the cross-sectional area of the strand before joining by surface tension of molten metal. Therefore, it is structurally strong and reliable.

  Further, compared with the case where the high energy density beam is irradiated from the direction perpendicular to the longitudinal direction of the electric wire, the focus of the high energy density beam is not shifted due to the height variation of the electric wire conductor portion arranged at the time of joining. Therefore, even if a plurality of electric wires are arranged, it is easy to focus the high energy density beam. For example, even when electric wires having different conductor diameters are joined, they can be joined easily.

  Moreover, it becomes possible to laminate and join the electric wires. Therefore, the degree of freedom in arranging the electric wires is higher than in the case where the electric wires are arranged on the same plane.

  In addition, by irradiating the end surfaces of the assembled wire conductors while moving the high energy density beam relatively, even if the number of wires is large or the melting part is wide, the whole is surely fused and integrated. Can be For this reason, even if the number of wires increases, the number of wires to be connected is not limited in principle.

  Moreover, welding can also be performed in a state where the irradiation position of the high energy density beam is fixed by irradiating the substantially center of the end surfaces of the assembled electric wire conductor portions with the high energy density beam.

ADVANTAGE OF THE INVENTION According to this invention, even if it is many electric wires, joining is reliably possible and the manufacturing method of a wire harness with the high freedom degree of arrangement | positioning of an electric wire can be provided.

It is a figure which shows the wire harness 1, Comprising: (a) is a perspective view, (b) is a side view. It is sectional drawing of the electric wire conductor part 7 of the wire harness 1, Comprising: (a) is the sectional view on the AA line of FIG.1 (b), (b) is the sectional view on the BB line of FIG.1 (b). The figure which shows the state which irradiates the laser 15. FIG. The figure which shows the state which installs the electric wire conductor part 7 in the jig 23. FIG. The figure which shows the state which irradiates the laser 15 using the jig 23. FIG. The figure which shows the method of irradiating with the laser. The figure which shows the other method of irradiating the laser 15. FIG. The figure which shows the other method of irradiating the laser 15. FIG. The figure which shows the other method of irradiating the laser 15. FIG. The figure which shows the other method of installing the electric wire conductor part 7 in the jig 23. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are diagrams showing a wire harness 1, in which FIG. 1A is a perspective view and FIG. 1B is a side view. The wire harness 1 is configured by joining a plurality of electric wires 3.

The electric wire 3 is configured by covering the outer periphery of the inner wire conductor portion 7 with an insulating coating 5. A predetermined range of the insulating coating 5 is removed from the end portion of the electric wire 3, and the electric wire conductor portion 7 is exposed. In addition, the electric wire conductor part 7 is a stranded wire in which a single wire or a plurality of strands made of copper or aluminum, for example, are combined, and generally has a size of about 0.13 to 5.0 cm ² .

  The electric wires 3 are assembled with their ends directed in substantially the same direction. The number of wires 3 to be joined is not limited to the illustrated example. The number and arrangement form of the electric wires 3 are appropriately set.

  At the tip end portion of the electric wire 3 (electric wire conductor portion 7), a fusion integrated portion 9 in which all the electric wire conductor portions 7 are fused and integrated is formed. An unmelted portion 11 in which the wire conductor portions 7 are not completely melted and integrated is formed on the insulating coating 5 side of the melted integrated portion 9. That is, in the non-melting part 11, the shape of the electric wire conductor part 7 before joining (or the strand which comprises this) is maintained.

  2 is a cross section perpendicular to the axial direction of the wire conductor portion 7 of the wire harness 1, and FIG. 2 (a) is a cross-sectional view taken along line AA of FIG. 1 (b), and FIG. 2 (b) is FIG. It is BB sectional drawing of (b). As shown in FIG. 2 (a), in the non-melting portion 11, the strands 13 constituting the respective wire conductor portions 7 are not melted, and the cross-sectional shape before joining is maintained. Although details will be described later, in the non-melting portion 11, all the strands of the wire 13 for each electric wire 3 are unwound so as to approach the cross-sectional shape of the electric wire holding portion of the jig described later. The wires 13 are randomly arranged without distinguishing the electric wires 3.

  On the other hand, in the fusion integrated part 9, all the electric wire conductor parts 7 (element wires 13) are fused and integrated with a predetermined cross-sectional shape. Here, in a cross section perpendicular to the axial direction, a cross-sectional area larger than the sum of the cross-sectional areas of the strands 13 of the non-melting part 11 is formed in at least a part of the fusion integrated part 9. That is, the joint portion has a joint cross-sectional area larger than the cross-sectional area of each strand 13.

  Next, a method for manufacturing the wire harness 1 will be described. First, the insulation coating 5 at the end of the electric wire 3 is removed by a predetermined length, and the internal electric wire conductor portion 7 is exposed. A plurality of electric wires 3 obtained in this way are assembled in the same direction. Normally, when the insulating coating 5 is removed, the inner strand 13 is untwisted and the strand 13 is in a separated state. Accordingly, the strands 13 are movable in the cross section. In addition, when the strand of the strand 13 is not returned as shown in FIG. 3A, for example, when the strand 13 has a large diameter, the strand 13 of the strand 13 is separately untwisted. You can spread it.

Next, as shown in FIG. 3B, the separated strands 13 are collected in the electric wire holding portion 24 of the jig 23. At this time, the position of the tip of the strand 13 is aligned with the position of the end face of the jig 23. As described above, the strands 13 can be easily moved with respect to the position in the cross section. For this reason, the strand 13 gathers so that it may become the electric wire holding part shape of the jig 23. FIG. By gathering in the electric wire holding part 24, it arrange | positions so that the adjacent strand 13 may contact in the inside of the electric wire holding part 24. FIG. Note that the jig 23 is formed by being divided into a plurality of pieces. For example, it is desirable to form the through-hole-shaped electric wire holding part 24 which can hold the strand 13 by combining a plurality of divided pieces. Further, when assembling the split pieces, it is desirable that the wire 13 in the electric wire holding portion 24 can be pressed into the shape of the electric wire holding portion 24 from the outer periphery. As such a structure, for example, when the electric wire holding part 24 has a rectangular cross section, the same structure as that of a sonotrode, a gliding jaw, an anvil plate, or an anvil used in known ultrasonic bonding (for example, Japanese Patent Application Laid-Open No. 2011-2011). 198506).
In the following description and drawings, for the sake of simplicity, an example in which a circular electric wire holding part 24 is formed by using two divided jigs 23 and combining the divided pieces is shown. It is not limited to the example.

  In this state, as shown in FIG. 4, the laser 15, which is a high energy density beam, is irradiated from the end face direction of the assembled electric wire conductor portions 7 in the substantially axial direction of the electric wires 3. At this time, the focal point of the laser 15 is adjusted to be the tip position of the electric wire conductor portion 7.

  FIG. 5 is a cross-sectional view showing the irradiation state of the laser 15. The jig 23 includes a laser transmitting portion 25, a laser reflecting portion 27, and the like.

  The laser transmitting portion 25 is made of a material having a softening point temperature higher than the melting point of the wire conductor portion 7. By doing in this way, when the electric wire conductor part 7 fuse | melts, it can prevent that the jig 23 melt | dissolves or softens simultaneously. When the laser 15 is irradiated, the temperature of the wire conductor portion 7 becomes equal to or higher than the melting point, but the laser output is adjusted so as to be lower than the softening point temperature of the laser transmitting portion 25 or lower than the melting point. Moreover, in order to prevent the fusion | melting of the laser transmission part 25 and the fuse | melted electric wire conductor part 7, as a material of the laser transmission part 25, there is no compatibility with the electric wire conductor part 7, but the compatibility of a chemical bond is bad. It is desirable to choose.

  In some cases, the laser 15 is irradiated to the laser transmitting portion 25. In this case, it is desirable that the laser transmitting portion 25 be made of a material having transparency with respect to the laser wavelength of the laser 15 to be irradiated. More preferably, the energy absorption rate is less than 1% with respect to the laser wavelength of the laser 15 to be irradiated. This is because when the energy absorption rate of the laser 15 is high, the laser transmitting portion 25 itself is melted by the laser 15.

For example, if the energy absorption rate of the irradiated material is less than 1%, even if the irradiated material is irradiated with a laser having an average power density of 430 MW / cm ^{2 at} a laser sweep speed of 30 to 50 mm / sec, The irradiated material is not processed. If the average power density is larger, the same effect can be obtained by increasing the laser sweep speed. On the other hand, an irradiated material (for example, copper material) having an energy absorption rate of about 7 to 9% is melted by the laser. Therefore, it is desirable for the laser transmitting unit 25 to transmit the laser 15 to be irradiated, and it is more preferable that the energy absorption rate is particularly less than 1%.

  As a material having an energy absorption rate of less than 1%, for example, quartz glass can be used. The laser transmitting portion 25 may be, for example, 1 mm to 5 mm. Note that when the laser 15 is fixed and only the center of the wire conductor portion 7 is irradiated, the laser transmitting rate of the laser transmitting portion 25 is high. May be.

  A laser reflection unit 27 is provided on the rear surface of the laser transmission unit 25 (the side opposite to the irradiation side of the laser 15) as necessary. This is to prevent the laser 15 from irradiating the insulating coating 5 or the like. As such a laser reflecting portion 27, for example, a metal film or a metal plate such as oxygen-free copper, tough pitch copper, or aluminum can be used, and in particular, the reflectance of the laser 15 to be irradiated is 90% or more. Is desirable.

  By using such a jig 23, it is possible to reliably hold the state in which the tip of the wire conductor portion 7 is in contact and irradiate the laser 15. Further, the jig 23 is not melted or softened by the laser 15 and is not melted and integrated with the electric wire conductor portion 7.

  FIG. 6 is a diagram showing a method of irradiating the wire conductor portion 7 with the laser 15. As a method of irradiating the laser 15, for example, as shown in FIG. 6A, the laser optical axis 17 (FIGS. 4 and 5) may be positioned substantially at the center of the assembled wire conductor portions 7. . That is, the irradiation part 19 of the laser 15 is set at the approximate center of the assembled electric wire conductor parts 7. In this case, the laser 15 is irradiated with the positions of both being fixed without moving the laser 15 or the electric wire 3 relatively.

  In the irradiation part 19 irradiated with the laser 15, the fusion integrated part 9 is formed while the strand 13 is melted. Further, in the non-irradiated portion of the electric wire conductor portion 7, the fusion integrated portion 9 spreads to the periphery by the heat conduction from the irradiation portion 19 and the flow of molten metal (in the direction of arrow C in the figure). When the fusion integrated part 9 spreads in the entire inside of the electric wire holding part 24, the whole is integrated and the joining is completed (FIG. 6 (b)).

  By doing so, there is no need to move the laser 15 or the like. Note that the average output density and irradiation time of the laser 15 need to be set in consideration of the melting range and the like so that all the assembled wire conductors 7 are melted. Moreover, the irradiation part 19 may irradiate not only the center of the electric wire holding part 24 but several places.

  Further, as shown in FIG. 7, the laser optical axis 17 may be relatively moved while irradiating the laser 15. That is, the laser moving shaft 21 is set so that the laser 15 is irradiated on substantially the entire assembled wire conductor portion 7. At this time, as shown in FIG. 7A, the laser moving shaft 21 is swept back and forth so that the weld beads formed by the laser irradiation overlap. In other words, the laser movement axis 21 may be set so as to have a movement locus in which the beads overlap.

  Such a sweep may be performed by moving a stage or the like to which the electric wire 3 is fixed in a state where the laser 15 is irradiated, or by using a galvano scanner to irradiate a line with a laser beam by a remote device. By irradiating the laser 15 so that all the wires 13 inside the electric wire holding part 24 are melted at least once, the whole of the wires 13 is integrated and the joining is completed (FIG. 7B). .

  By doing in this way, the output of the laser 15 can be made substantially constant, and the entire melting range can be reliably fused and integrated. The moving method of the laser moving shaft 21 is not limited to the illustrated example, and is appropriately set in consideration of the number of electric wires arranged, the melting range, and the like. In order to fuse and integrate the wire conductor portion 7 more reliably, it is desirable to move the entire laser moving shaft 21 within a range slightly wider than the region of the wire conductor portion 7.

  Here, in any of the above-described irradiation methods, when the end portion of the wire conductor portion 7 (elementary wire 13) is melted, the tip position of the wire conductor portion 7 is caused by wetness of the molten metal or surface tension. The molten metal flows rearward in the axial direction (on the insulating coating 5 side and leftward in FIG. 1B). That is, at the time of joining, the wire conductor portion 7 exposed from the insulating coating 5 is melted and integrated while the length is shortened.

  As described above, the molten integrated portion 9 is formed such that the molten metal aggregates due to surface tension or the like, and as described above, the cross-sectional area of the molten integrated portion 9 is changed to each strand in the non-molten portion 11. It can be made larger than the sum of 13 cross-sectional areas. Therefore, the bonding area is large, and strength reduction due to necking or the like can be prevented.

  As mentioned above, according to this invention, many electric wires 3 can be integrated reliably. Moreover, it is not necessary to arrange the electric wire conductor part 7 flatly on a plane. Therefore, the focus position of the laser 15 is shifted due to variations in the height of the wire conductor portion 7 provided, and there is no fear of poor welding or the like. Further, the shape of the joint portion can be the shape (cross-sectional shape and side surface shape) of the electric wire holding portion 24 of the jig 23. Accordingly, the shape of the joint can be made constant.

  If the laser 15 is swept and irradiated, the number of wires 3 to be joined is theoretically unlimited. Moreover, the cross-sectional area of the fusion integrated part 9 can be made larger than the sum of the cross-sectional areas of the strands 13 before joining. Therefore, strength reduction due to necking or the like can be prevented.

  Moreover, the multiple electric wire conductor part 7 can be laminated | stacked and arranged in multiple layers. Therefore, the degree of freedom of arrangement of the wire conductor portion 7 is greater than in the case where the wire conductor portion 7 is provided flat on a plane.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, as the high energy density beam, not only a laser but also an electron beam can be applied.

  Further, when the laser 15 is swept, the laser moving shaft 21 is not limited to the example of FIG. 7 described above. For example, as shown in FIG. 8, the laser moving shaft 21 may be formed in a spiral shape from the center of the assembled wire conductor portions 7. Even in this case, as shown in FIG. 8A, the trajectory of the laser moving shaft 21 is set at such a pitch that the beads overlap. By irradiating the whole inside of the electric wire holding part 24, the whole strand 13 is integrated and joining is completed (FIG.8 (b)).

  Similarly, as shown in FIG. 9, the laser moving shaft 21 may be formed over the whole while moving finely in an arc shape so that the entire wire conductor portion 7 can be irradiated. Even in this case, as shown in FIG. 9A, the trajectory of the laser moving shaft 21 is set at a pitch such that the beads overlap. By irradiating the whole inside of the electric wire holding part 24, the whole strand 13 is integrated and joining is completed (FIG.9 (b)).

  Moreover, in this invention, as shown to Fig.10 (a), the electric wire conductor parts 7 from which a diameter differs can also be joined. In this case, the arrangement of the wire conductor portion 7 is arbitrary. Even if the wire conductor portions 7 have different diameters, as shown in FIG. 10B, if the strands 13 can be assembled in the jig 23, for example, by sweeping the laser 15 and irradiating the whole with the laser 15, It can be fused and integrated in the same manner as described above. In addition, when the strand of the strand 13 does not return even if the insulation coating 5 is removed, such as when the diameter of the strand 13 is large, the strand 13 is untwisted and then the strand 13 is connected to the electric wire of the jig 23. What is necessary is just to gather in a holding | maintenance part.

  In the above description, the shape of the electric wire holding part 24 of the jig 23 is circular, but the present invention is not limited to this. For example, the shape of the electric wire holding part 24 can be a desired shape such as a rectangle or a triangle.

DESCRIPTION OF SYMBOLS 1 ......... Wire harness 3 ......... Electric wire 5 ......... Insulation coating 7 ......... Wire conductor part 9 ......... Melting integrated part 11 ...... Non-melting part 13 ...... Wire 15 ......... Laser 17... Laser beam axis 19... Irradiation section 21... Laser movement axis 23... Jig 24.

Claims (7)

A method of combining a plurality of electric wires from which end insulation coating has been peeled off and joining so that the tips are oriented in substantially the same direction,
Electric wire holding of a jig having a tip of the wire conductor portion of the plurality of wires having a softening point temperature or a melting point higher than the melting point of the wire conductor portion and holding the tip from the side in the longitudinal direction of the wire. Place and gather in the department,
In a state where the strands of the wire conductor part are in contact with each other from the side, irradiate a high energy density beam from the extending direction of the end face of the wire conductor part, and at a temperature below the softening point temperature or below the melting point of the jig, A method of manufacturing a wire harness, comprising melting and integrating a tip of the wire conductor portion within an inner wall surface of the wire holding portion.   2. The method of manufacturing a wire harness according to claim 1, wherein the jig is made of a material having an absorptance of the high energy density beam of less than 1% with respect to the wavelength of the high energy density beam.   3. The wire harness according to claim 1, wherein a cross-sectional area larger than the sum of the cross-sectional areas of the wire conductors of the electric wire conductor in the non-melting part is formed in at least a part of the fusion integrated part. Production method.   The method of manufacturing a wire harness according to any one of claims 1 to 3, wherein the three or more electric wires are stacked and assembled without being provided on the same plane.   By irradiating the gathering position of the high energy density beam relative to the end surfaces of the assembled wire conductor portions, the tips of all the wire conductor portions are melted. The manufacturing method of the wire harness in any one of Claim 1 to 4.   The tip of all the said electric wire conductor parts is fuse | melted by irradiating the said high energy density beam to the approximate center of the end surface of the assembled said electric wire conductor parts. The manufacturing method of the wire harness of crab.   The method of manufacturing a wire harness according to any one of claims 1 to 6, wherein the high energy density beam is one of a laser and an electron beam.

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