JP2011055624A - Circuit structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit structure that is made of a metal wire having an excellent yield and also capable of coping with a complicated circuit configuration, and has a new structure. <P>SOLUTION: A plurality of cut wires 14a, 14b, 16a, 16b obtained by cutting the metal wire are partially subjected to press forging to form a junction section 22 including a wide and flat cross section, and the plurality of cut wires 14a, 14b, 16a, 16b are overlapped in a board thickness direction, namely a press forging direction for joining at each junction section 22, thus forming the circuit structure 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a circuit structure that is housed in an electric junction box of an automobile and constitutes an internal circuit.

  Conventionally, in an electric junction box of an automobile, an internal circuit is configured by a bus bar which is a conductive metal plate, and an efficient distribution of electric power from a battery to an in-vehicle electrical component or the like is performed. Since this bus bar is obtained by pressing a metal flat plate material, a terminal portion (tab portion) and a branch circuit can be easily formed by pressing the metal plate into an arbitrary shape.

  By the way, since the internal circuit of the electric junction box differs depending on the vehicle type and specifications, a large number of bus bars having various shapes are required. In this case, it is necessary to prepare a mold in accordance with various shapes of the bus bar, which leads to an increase in cost. Further, since it is formed by pressing a flat metal material, there are many waste materials, and there is a problem of poor yield.

  Therefore, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-32960), it has been proposed that an internal circuit structure is formed by cutting a metal wire into a predetermined length and bending it into a predetermined shape. According to this, since the internal circuit constituting body can be obtained only by bending the metal wire cut to a predetermined length, there is almost no waste material and the yield can be improved. Further, it is not necessary to prepare a special mold according to the shape of the circuit structure, and the cost can be reduced.

  However, in such a circuit structure made of a metal wire, one-to-one serial connection at both ends of the metal wire is possible, but there is a problem that it cannot cope with a complicated circuit structure. In other words, since the metal wire has a small cross-sectional area and a shape extending long, the metal wire does not have a sufficient area for projecting a plurality of terminal portions or connecting branch circuits. It was difficult to realize other than one connection.

JP 2004-32960 A

  The present invention has been made in the background of the above-mentioned circumstances, and the solution to the problem is to provide a circuit structure having a novel structure made of a metal wire that has a high yield and can cope with a complicated circuit structure. There is to do.

  According to a first aspect of the present invention, there is provided a circuit structure formed by a plurality of cutting wires obtained by cutting a metal wire and housed in an electric junction box of an automobile to constitute an internal circuit. Is formed by partially forging and forming a flat cross-sectional joint that is wider than the metal wire, and the plurality of cut wires are overlapped in the plate thickness direction that is the forging direction in each joint. It is characterized by being joined.

  According to the present invention, a joining portion having a larger area than other portions can be provided by partially plastically deforming the cutting wire to form a flat portion. Thereby, the joining of the wire rod which is stable in a wide area is realizable by overlapping and joining the junction parts of a cutting wire rod. Therefore, it becomes possible to reliably bond the cutting wires, and it is possible to realize a complicated circuit configuration by combining a plurality of cutting wires while taking advantage of a thin wire with good yield.

  According to a second aspect of the present invention, in the one described in the first aspect, the plurality of cutting wires are provided with the joint portion at an intermediate portion and bent at both ends to form a terminal portion. And a second cutting wire in which the joint portion is provided at one end and a terminal portion is provided at the other end.

  According to this aspect, it is possible to form a branch circuit by combining the first cutting wire. In addition, by joining the joining portion of the second cutting wire to the joining portion of the first cutting wire, a large number of terminal portions can be formed on one conductive path.

  According to a third aspect of the present invention, in the one described in the first or second aspect, a thickness dimension in a superposition direction of a portion where the joint portions of the plurality of cutting wire materials are superposed is the superposition direction. The thickness is not more than the thickness of the cutting wire in the mating direction.

  According to this aspect, the protrusion of the overlapping portion at the joint portion is suppressed, and the problem that the plate thickness of the joint portion is doubled due to the overlapping can be avoided, for example, like a bus bar. Thereby, for example, when a multilayer circuit board is formed by stacking a plurality of insulating plates, the board thickness can be reduced.

  In addition, since the joint portion of the cutting wire is formed by forging processing, for example, compared to the case of cutting the cutting wire to reduce the plate thickness of the joint portion, the material is not particularly wasted. A junction having a small thickness can be formed.

  According to the present invention, by forming the joining portion of the flat cross section by the forging process on the cutting wire, it is possible to reliably join the cutting wires with an effective area. Thereby, a more complicated circuit configuration can be realized by combining a plurality of cutting wires while utilizing the good yield of the cutting wires.

The perspective view which shows the insulating board and printed circuit board provided with the circuit structure as one Embodiment of this invention. The disassembled perspective view of the circuit structure shown in FIG. The side view of the circuit structure shown in FIG. The perspective view which shows the circuit structure as a different aspect of this invention.

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

  First, FIG. 1 shows an insulating plate 12 provided with a circuit structure 10 as an embodiment of the present invention. The insulating plate 12 provided with the circuit structure 10 is housed together with the printed circuit board 13 in an upper case and a lower case (not shown) that constitute an electric junction box of an automobile. Thereby, the circuit structure 10 comprises the internal circuit of an electrical-connection box.

  As shown in FIG. 2, the circuit structure 10 according to the present embodiment is formed by joining four cutting wires, ie, a pair of first cutting wires 14 a and 14 b and a pair of second cutting wires 16 a and 16 b. Has been. These cutting wires 14a, 14b, 16a, and 16b are all formed from a metal material having conductivity such as gold, copper, or a copper alloy, or a metal material such as iron plated on the surface with the conductive metal material. The formed metal wire is cut by a predetermined length. The cross-sectional shape of the cutting wire 14a, 14b, 16a, 16b is not particularly limited, and a rectangular shape such as a square or a rectangle, a circular shape including an ellipse, or any other shape can be appropriately employed. The cutting wire rods 14a, 14b, 16a, and 16b in the present embodiment are all square sections having the same size, have no direction during bending, and can be bent in any direction. In this way, more flexible circuit routing is possible.

  Terminal portions 18a and 18b that are bent substantially vertically in the same direction using a suitable jig or the like are integrally formed at both ends in the length direction of the first cutting wire 14a. Thereby, the circuit part 20 is formed between the terminal parts 18a and 18b. The circuit unit 20 is bent into a desired circuit routing shape using an appropriate jig or the like, but the circuit unit 20 of the first cutting wire 14a has a linear shape.

  Furthermore, the joint part 22 is integrally formed in the center part of the length direction of the 1st cutting wire 14a. The joint portion 22 has a substantially rectangular flat cross-sectional shape, the length of the long side of the rectangular cross section is longer than one side of the square cross section of the first cutting wire 14a, and the length of the short side is the first. The cutting wire 14a is shorter than one side of the square cross section. Thereby, the joining part 22 is made wider than the circuit part 20, and both longitudinal ends of the rectangular cross section protrude outwardly in the direction perpendicular to the axis from the non-formed part of the joining part 22 in the circuit part 20. .

  Then, the overlapping surface 24 (see FIG. 3) in which the surface constituting one long side portion of the rectangular cross section in the bonding portion 22 is recessed from the non-formed portion of the bonding portion 22 in the thickness direction of the circuit portion 20. It is said that. In addition, the length dimension of the short side of the rectangular cross section of the junction part 22 is made into about half of one side of the square cross section of the 1st cutting wire 14a. As a result, the overlapping surface 24 is positioned approximately at the center of the square cross section of the first cutting wire 14a, while the surface of the bonding portion 22 that is opposite to the overlapping surface 24 is the side surface of the circuit portion 20. The wide surface 26 is formed on the same plane and partially widens the side surface of the circuit unit 20 to both sides in the direction perpendicular to the axis.

  In addition, the junction part 22 is integrally formed by forging the center part of the length direction of the 1st cutting wire 14a. For example, in a state where the first cutting wire 14a is placed on one flat mold, the other die corresponding to the length of the joint portion 22 is inserted from the opposite side across the first cutting wire 14a. It is preferably formed by pressing with a press machine or the like. Thereby, the junction part 22 of the rectangular cross section which makes a forge pressure direction a plate | board thickness direction is formed.

  On the other hand, the first cutting wire 14b has substantially the same shape as the first cutting wire 14a, and has terminal portions 18c and 18d at both ends of the circuit portion 20. As described above, the circuit unit 20 is bent into a desired circuit arrangement shape, and the circuit unit 20 of the cutting wire 14b has an L shape with a bent portion 28 formed therein.

  In the first cutting wire 14b, a joint 22a is formed at a substantially central portion in the length direction, and joints 22b and 22c are formed on both sides of the circuit part 20 with the joint 22a interposed therebetween. ing. The joining part 22a is formed in the size substantially equal to the joining part 22 formed in the 1st cutting wire 14a. On the other hand, the length dimension of the joining parts 22b and 22c is made larger than the joining part 22a. In addition, while the junction part 22b is made into the concave shape opened to the opposite side (in FIG. 2, upper direction) equal to the junction part 22a, the junction part 22c is opposite to the junction part 22b, and the insulation board 12 is used. It is made into the concave shape which opens toward.

  Moreover, since the 2nd cutting wire 16a, 16b is made into the mutually same shape, the 2nd cutting wire 16a is demonstrated. The second cutting wire 16a is formed by forging one end portion so that the joining portion 22 is integrally formed at one end portion and the terminal portion 18e (18f) is integrally formed at the other end portion. Has been. In addition, although the terminal part 18e may be formed by vertically bending the position deviated from the flat cross-sectional shape of the joint part 22 in the cutting wire 16a, in this embodiment, the terminal part 18e is formed at the time of forging of the joint part 22. The flat cross section is bent. Thereby, rolling at the time of bending at the time of forming the terminal portion 18e can be prevented, and stable bending can be performed. Further, the second cutting wire 16a has an overlapping surface 24 formed on the surface opposite to the protruding direction of the terminal portion 18e in the joint portion 22.

  And the overlapping surface 24 of the joining part 22 in the first cutting wire 14a is superposed in the plate thickness direction of the joining parts 22 and 22a on the overlapping surface 24 of the joining part 22a in the first cutting wire 14b. Are joined together. In addition, the overlapping surface 24 of the joint portion 22 in the second cutting wire 16a is overlapped with the overlapping surface 24 of the joint portion 22b in the first cutting wire 14b in the thickness direction of the joint portions 22 and 22b. Are joined together. Furthermore, the overlapping surface 24 of the joint portion 22 in the second cutting wire 16b is overlapped with the overlapping surface 24 of the joint portion 22c in the first cutting wire 14b in the thickness direction of the joint portions 22 and 22c. Are joined together. In addition, as a joining method of the joining parts 22, for example, a joining method using a conductive adhesive such as soldering can be adopted. However, resistance welding, ultrasonic welding, and the like do not require an adhesive and are thick. Since an increase in the size is also suppressed, it is preferably employed.

  Thereby, the circuit structure 10 is formed. As shown in FIG. 3, the thickness dimension t in the overlapping direction (vertical direction in FIG. 3) of the portion where the pair of bonding portions 22 and 22 are overlapped is t in the overlapping direction of the bonding portions 22 and 22. The thickness dimension of one cutting wire 14a, 14b is set to T or less. In the present embodiment, since the thickness dimension of the joint portion 22 is substantially half of the thickness dimension T of the first cutting wire rods 14a and 14b, the thickness at the overlapping portion of the joint portions 22 and 22 is as follows. The dimension t is substantially equal to the thickness dimension T of the first cutting wire rods 14a and 14b.

  The circuit structure 10 having such a structure is disposed on the insulating plate 12 as shown in FIG. The insulating plate 12 is a plate-like member formed of a synthetic resin having electrical insulation. The insulating plate 12 is formed with a concave groove-shaped accommodation recess 30 corresponding to the wiring shape of the circuit component 10. And the circuit structure 10 is arrange | positioned on the insulating board 12 by the circuit part 20 of the circuit structure 10 being accommodated in the accommodation recess 30. FIG. The terminal portion 18f protruding from the circuit portion 20 toward the insulating plate 12 opens from the bottom surface of the housing recess 30 and protrudes from the insulating plate 12 through an insertion hole (not shown) penetrating the insulating plate 12. It has become.

  Then, the insulating plate 12 provided with the circuit structure 10 is housed in an upper case and a lower case (not shown) together with the printed circuit board 13 and the like, so that an electrical connection box is configured. The insulating plate 12 provided with the circuit structure 10 is accommodated in an electrical junction box as a multilayer circuit board in which a plurality of layers are stacked as necessary. The terminal portions 18a to 18f of the circuit structure 10 are exposed to the outside of the electrical connection box through insertion holes that pass through the upper case and the lower case, and can be connected to external wiring, for example, the terminal portions 18f shown in FIG. As described above, the insulating plate 12 is inserted into the through hole 32 of the printed circuit board 13 accommodated in the electrical connection box, and is connected to a printed wiring (not shown) formed on the printed circuit board 13.

  According to the circuit structure 10 in the present embodiment, since it is formed using the cutting wire rods 14a, 14b, 16a, and 16b, it is a waste material as compared with a conventional bus bar formed by punching a flat metal material. The manufacturing cost can be reduced because the molding die is not necessary. In addition, since a long and thin wire is used, a heat generation suppressing effect can be achieved as compared with a conventional flat bus bar, and a high density of circuits can be achieved by arranging a plurality of cutting wires close to each other. You can also. A branch circuit can be formed by joining the first cutting wire members 14a and 14b, and by connecting the second cutting wire members 16a and 16b to the first cutting wire member 14b, the number of terminals can be increased. The terminal can be provided at an optimum position on the circuit wiring. Thereby, one-to-many connection can be realized while using the cutting wire, and more complicated circuit wiring can be performed using the cutting wire.

  In particular, in the present embodiment, the overlapped area is effectively ensured by forming the joining section 22 having a flat cross section. Thereby, even if it is elongate cutting wire 14a, 14b, 16a, 16b, it can join reliably. Furthermore, in the joining parts 22 and 22a of the first cutting wire rods 14a and 14b, more stable joining is possible by fitting each other.

  Further, since the joining portions 22 and 22 are formed on the cutting wire rods 14a, 14b, 16a, and 16b having a predetermined thickness dimension: T, the thickness dimension t in the overlapping portion of the joining portions 22 and 22 is set to The thickness dimension of one cutting wire 14a, 14b can be set to T or less. As a result, the joining portions 22 and 22 can be overlapped without increasing the thickness dimension of the circuit portion 20, and in particular, a multilayer circuit board is formed by overlapping a plurality of insulating plates 12 including the circuit structure 10. In such a case, the substrate thickness can be reduced. Further, since the joint portion 22 is formed by forging, a thin joint portion 22 can be formed without generating waste material as in cutting.

  In addition, by using the cutting wires 14a, 14b, 16a, and 16b, the circuit shape can be maintained without using special fixing means such as a single core wire. Therefore, it can be easily mounted on the insulating plate 12, and the stability of electrical connection is ensured while maintaining the circuit shape. In particular, since the circuit portion 20 is partially widened by the wide surface 26 of the joint portion 22, more excellent mounting stability can be achieved while maintaining the current cross-sectional area substantially the same.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the terminal portions 18a, 18b, 18c, and 18d formed on the first cutting wire rods 14a and 14b in the above embodiment all protrude from the circuit portion 20 in the same direction, but the present invention shown in FIG. Of course, each of the first cutting wire members 14a and 14b can be protruded in opposite directions as in the circuit configuration body 40 as a different aspect of the above. In this aspect, the through-hole 42 is formed in the position away from the accommodation recess 30 in the insulating plate 12, and the terminal portion 18a of the first cutting wire 14a and the terminal portion 18d of the first cutting wire 14b are provided. The through hole 42 protrudes toward the printed circuit board 13 and is inserted into the through hole 32 of the printed circuit board 13.

  In addition, the cutting wire that forms the circuit structure is not limited to the one in which the terminal portion is formed at the end, for example, at both ends in order to connect a pair of cutting wires having the terminal portion to each other. You may use the cutting wire which has a junction part. Further, in the first cutting wire members 14a and 14b, the terminal portions 18 are formed at both ends of the circuit portion 20. For example, a terminal portion is provided at one end of the circuit portion, and a joint portion is provided at the other end. It is also possible to employ a cutting wire or the like that has been formed.

  In addition, the specific shape of the joint portion is not limited to the rectangular plate shape as in the above embodiment, and the joint portion may be formed in a disk shape or an arbitrary polygonal plate shape, for example. Further, the number of cut wire rods is not limited to two layers as in the above-described embodiment. For example, three or more cut wire rods may be overlapped.

  In addition, the circuit structure illustrated in this specification is shown in a simplified manner for easy understanding, and the number and specific shape of the cutting wire are not limited at all, and the required circuit Of course, it is set appropriately in consideration of the routing shape and the like.

10, 40: circuit structure, 12: insulating plate, 13: printed circuit board, 14a, b: first cutting wire, 16a, b: second cutting wire, 18a-f: terminal portion, 22: bonding portion, 24: Superposition surface

Claims (3)

In a circuit structure that is formed by a plurality of cutting wires obtained by cutting a metal wire and is housed in an electric junction box of an automobile to constitute an internal circuit,
The plurality of cutting wires are partially forged and formed into joint portions having a flat cross section that is wider than the metal wires, and the plurality of cutting wires are in the forging direction at the respective joint portions. A circuit structure characterized by being overlapped and joined in the thickness direction.   The plurality of cutting wire rods are provided with a first cutting wire rod in which the joint portion is provided at an intermediate portion and both end portions are bent to be terminal portions, and the joint portion is provided at one end portion. The circuit structure according to claim 1, comprising a second cutting wire having a terminal portion at the other end.   The thickness dimension in the superimposition direction of the part which overlap | superposed each said junction part of these some cutting wire materials is below the thickness dimension of the said cutting wire material in this superposition direction. Circuit construct.

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