JP2015053787A - High voltage electrical connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high voltage electrical connection box having a novel structure capable of reducing contact resistance between a high voltage bus bar and a low voltage bus bar and advantageously attaining reduction in size and weight.SOLUTION: A plate thickness dimension of a high voltage bus bar 16 is made larger than that of a low voltage bus bar 20. A connection part 40 between the high voltage bus bar 16 and the low voltage bus bar 20 is formed of a mechanical clinch obtained by overlapping the high voltage bus bar 16 on the low voltage bus bar 20 and pressing the bus bars from the high voltage bus bar 16 side into the low voltage bus bar 20 side.

Description

  The present invention relates to an electrical junction box mounted on an automobile or the like, and more particularly to a high voltage electrical junction box having a high voltage circuit built therein.

  Conventionally, an electrical connection box such as a relay box or a junction box has been used in an electrical system of an automobile, and an efficient distribution of electric power from a battery to an in-vehicle electrical component or the like is performed through the electrical connection box. . In particular, in recent electric vehicles and the like, an increasing number of vehicles use a high voltage and large current between the battery and the inverter. For example, as described in Japanese Patent Application Laid-Open No. 2006-50768 (Patent Document 1), the vehicle is configured by a bus bar. High-voltage electrical junction boxes equipped with high-voltage circuits are also used.

  By the way, in such a high-voltage electrical junction box, as described in Patent Document 1, a low-pressure circuit that is branched from a high-voltage circuit that is configured by a relatively thick bus bar and that is configured by a bus bar that is thinner than that. Branching and distributing electric power is performed by connecting to the main circuit. Therefore, the high voltage bus bar that constitutes the high voltage circuit and the low voltage bus bar that constitutes the low voltage circuit are connected to each other by connecting the tabs protruding from the respective connection parts through electrical components such as fuses and relay terminals. The electrical connection is established by connecting or fastening the high-pressure bus bar and the low-pressure bus bar to each other and fastening them with bolts and nuts.

  However, in such a conventional structure, it is necessary to connect the high-voltage bus bar and the low-voltage bus bar via separate parts such as a relay terminal, which avoids an increase in the number of parts, assembly man-hours, and the need for dedicated equipment. There was no problem. In addition, since the high-pressure bus bar and the low-pressure bus bar are connected via separate parts, there is a problem that the contact resistance is inevitably increased.

  Furthermore, when the respective tab portions of the high-pressure bus bar and the low-pressure bus bar are connected via different parts, the height dimension of the connection portion increases. Also, when the high-pressure bus bar and the low-pressure bus bar are overlapped with each other and fastened with bolts and nuts, it is necessary to secure a mounting region for the bolts and nuts. In any case, it is inevitable to increase the size of the electrical junction box, and the use of separate parts increases the weight. Therefore, it is difficult to meet the recent demand for smaller and lighter electrical junction boxes. There was also.

JP 2006-50768 A

  The present invention has been made against the background described above, and the problem to be solved is that the contact resistance of the connection portion between the high-pressure bus bar and the low-pressure bus bar can be reduced, and further reduced in size and weight. It is an object of the present invention to provide a high-voltage electrical junction box having a novel structure that can advantageously achieve the above.

  According to a first aspect of the present invention, there is provided a high-pressure bus bar plate including a high-voltage circuit constituted by a high-pressure bus bar and a low-voltage circuit constituted by a low-pressure bus bar. While the thickness dimension is larger than the plate thickness dimension of the low-pressure bus bar, the connection portion between the low-pressure bus bar and the high-pressure bus bar overlaps the high-pressure bus bar with the low-pressure bus bar. It is formed by a mechanical clinch pushed into the low-pressure bus bar side from the bus bar side.

  In the high-voltage electrical junction box having the structure according to the present invention, the high-pressure bus bar and the low-pressure bus bar are directly connected to each other by a mechanical clinch without using another component. Thereby, the contact load in the connection part of the bus bar for high voltage | pressure and the bus bar for low voltage | pressure can be ensured effectively, and contact resistance can be reduced.

  And, since no separate parts such as relay terminals and bolts are required to connect the high-voltage bus bar and the low-voltage bus bar, the number of parts can be reduced, and the connection of the relay terminals and the bolt fastening work are unnecessary. Therefore, the manufacturing cost can be reduced. In addition, for example, after dividing the low-pressure bus bar by press processing, multiple high-pressure bus bars can be overlapped and pressed again, so that multiple locations can be connected simultaneously with mechanical clinch, further improving production efficiency You can also. In addition, since the high-pressure bus bar and the low-pressure bus bar are connected without requiring a separate member, the connecting portion can be made smaller than, for example, a bolt or the like. At the same time, the connection portion can be reduced in weight by reducing the number of parts. As a result, the high-voltage electrical junction box can be reduced in size and weight.

  In addition, the increase in the width dimension of the high-pressure bus bar can be suppressed by securing the current cross-sectional area by making the plate thickness dimension of the high-pressure bus bar larger than that of the low-pressure bus bar. Space saving of the wiring space can be achieved. And by pushing in from the bus bar side for high voltage | pressure with a large board | plate thickness dimension and forming a mechanical clinch, the possibility of causing the molding defect of a mechanical clinch can be reduced.

  According to a second aspect of the present invention, in the one described in the first aspect, in the low-pressure bus bar, an overlapping portion with the high-pressure bus bar on which the connection portion is formed is formed wide. It is.

  According to this aspect, by ensuring the width dimension of the connecting portion in the low-pressure bus bar, the molding quality of the mechanical clinch can be ensured to a higher degree. Further, by ensuring a larger contact area with the high-pressure bus bar, the connection reliability with the high-pressure bus bar can be improved.

  A third aspect of the present invention is the one described in the first or second aspect, wherein a plurality of the low-pressure bus bars are connected to one high-pressure bus bar.

  As described above, according to the present invention, it is also possible to form a plurality of mechanical clinches at the same time. When a plurality of low-pressure bus bars are connected to the high-pressure bus bar as in this aspect, a plurality of mechanical clinches are used. The low pressure bus bar can be connected simultaneously.

  According to a fourth aspect of the present invention, in the apparatus according to any one of the first to third aspects, at least one of the high-pressure bus bars to which the low-pressure bus bar is connected is inserted into a current sensor. It is what.

  According to the present invention, since the low-pressure bus bar and the high-pressure bus bar are connected with a high contact load by mechanical clinching, fluctuations in the contact resistance between the low-pressure bus bar and the high-pressure bus bar can be suppressed. Therefore, the detection accuracy of the current sensor can be improved by using the high-voltage bus bar as a bus bar inserted into the current sensor.

  In the present invention, the plate thickness dimension of the high-pressure bus bar is made larger than the plate thickness dimension of the low-pressure bus bar, and the connecting portion between the high-pressure bus bar and the low-pressure bus bar is pushed from the high-pressure bus bar side to the low-pressure bus bar side. It was formed by mechanical clinch. Thereby, the contact load between the high-pressure bus bar and the low-pressure bus bar can be effectively ensured, and the contact resistance can be reduced. Furthermore, by connecting the high-pressure bus bar and the low-pressure bus bar without using separate parts, the manufacturing cost of the high-voltage electrical junction box can be reduced, and the size and weight can be reduced.

The disassembled perspective view of the high-voltage electrical junction box as one embodiment of the present invention. The top view of the bus bar for high pressures and the bus bar for low pressures. III-III sectional drawing in FIG. 2 of the bus bar for high voltage | pressure and the bus bar for low voltage | pressure connected to this. A photograph showing a cross section of a connection part. The perspective view for demonstrating the joining process of the connection part of the bus bar for high voltage | pressure and the bus bar for low voltage | pressure. The principal part enlarged view of the VI-VI cross section of FIG.

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

  First, FIG. 1 shows a high-voltage electrical junction box 10 as an embodiment of the present invention. The high-voltage electrical junction box 10 accommodates a high-voltage circuit 18 composed of a plurality of high-pressure bus bars 16 and a low-voltage circuit 22 composed of a plurality of low-pressure bus bars 20 between an upper case 12 and a lower case 14 made of synthetic resin. In addition, various electric parts such as the current sensor 24 and the relay 26 are accommodated.

  2 and 3 show the high voltage circuit 18 and the low voltage circuit 22. In the following description, the high-pressure bus bar 16 that constitutes the high-voltage circuit 18 and the low-pressure bus bar 20 that constitutes the low-voltage circuit 22 will be referred to as being specific, such as the high-pressure bus bar 16a and the low-pressure bus bar 20a. Unless otherwise specified, the high-pressure bus bar 16 and the low-pressure bus bar 20 will be described. FIG. 3 illustrates only high-pressure bus bars 16a and 16b, which will be described later, and low-pressure bus bars 20a to 20d connected thereto.

  The high voltage circuit 18 includes high voltage bus bars 16a and 16b. The high-pressure bus bars 16a and 16b are formed by stamping and bending a metal plate made of copper, copper alloy, or the like, and are set in any shape in consideration of the circuit wiring shape of the high-voltage circuit 18 and the like. Can be done. The high-pressure bus bars 16a and 16b of the present embodiment have a strip shape extending substantially in a straight line. A bolt insertion hole 28 is provided through one end portion, and a relay 26 is provided at the other end portion. A tab-shaped relay connecting portion 30 connected to (see FIG. 1) is formed by being raised.

  On the other hand, the low-pressure circuit 22 includes a plurality of low-pressure bus bars 20. Each low-pressure bus bar 20 is formed by stamping and bending a metal plate made of copper, copper alloy, or the like, and is set in an arbitrary shape in consideration of the circuit arrangement shape of the low-voltage circuit 22. obtain. Among these low-pressure bus bars 20, the low-pressure bus bar 20a is connected to the high-pressure bus bar 16a, while the low-pressure bus bars 20b to 20d are connected to the high-pressure bus bar 16b. Each of the low-pressure bus bars 20a to 20d has an overlapping portion 34 that is overlapped with the high-pressure bus bar 16a or the high-pressure bus bar 16b on one end edge of the circuit portion 32 formed in a desired wiring shape. The terminal portion 36 is formed at the other end portion. Each of the overlapping portions 34 of the low-pressure bus bars 20a to 20d has a side length substantially equal to the width dimension (the vertical dimension in FIG. 2) of the high-pressure bus bar 16a or the high-pressure bus bar 16b to be superimposed. The plate has a substantially square plate shape, and is formed with a larger width dimension (dimension in the left-right direction in FIG. 2) than the circuit portion 32. Further, the terminal portion 36 of the low-pressure bus bar 20a, 20b, 20c has a tab shape that is vertically raised from the circuit portion 32, while the terminal portion 36 of the low-pressure bus bar 20d is the end portion of the circuit portion 32. It is made into the shape by which the screw hole was penetrated by.

As is clear from FIG. 3, the plate thickness dimension: t _h of the high-pressure bus bar 16 is made larger than the plate thickness dimension: t _l of the low-pressure bus bar 20. The plate thickness dimension: t _h of the high-pressure bus bar 16 and the plate thickness dimension: t _l of the low-pressure bus bar 20 can be arbitrarily set in consideration of the required energization capacity and the like. In the present embodiment, the plate thickness dimension: t _h of the high-pressure bus bar 16 is set to 2.0 mm or 2.5 mm, and the plate thickness dimension: t _l of the low-pressure bus bar 20 is set to 0.8 mm.

  The low-pressure bus bar 20a is connected to the high-pressure bus bar 16a, and the low-pressure bus bars 20b to 20d are connected to the high-pressure bus bar 16b. The low-pressure bus bar 20a and the high-pressure bus bar 16a, and the low-pressure bus bars 20b to 20d and the high-pressure bus bar 16b are all connected in the same structure. FIG. 4 illustrates the cross section of the connecting portion 40 between the low-pressure bus bar 20a and the high-pressure bus bar 16a.

  The connection part 40 is formed by mechanical clinch. In the connecting portion 40, the high-pressure bus bar 16a is overlapped with the overlapping portion 34 of the low-pressure bus bar 20a. The high-pressure bus bar 16a is overlapped in a direction orthogonal to the extending direction of the circuit portion 32 from the overlap portion 34 (upward in FIG. 2).

  The connecting portion 40 is composed of bottomed cylindrical portions 42a and 42b having a bottomed cylindrical shape in which a high-pressure bus bar 16a and a low-pressure bus bar 20a protrude from the high-pressure bus bar 16a side to the low-pressure bus bar 20a side in substantially the same shape. ing. On the bottom portions 44a and 44b of the bottomed tube portions 42a and 42b, annular protrusions 46a and 46b are formed with outer peripheral edge portions projecting in an annular shape obliquely outward. By these annular protrusions 46a and 46b, the outer diameter of the bottomed cylindrical portion 42a of the high-pressure bus bar 16a is expanded on the bottom 44a side to form an annular engagement convex portion 48, while the low-pressure bus bar 20a The inner diameter of the bottomed cylindrical portion 42b is expanded on the bottom portion 44b side to form an annular engagement recess 50. Then, the bottomed cylindrical portion 42a of the high-pressure bus bar 16a is pushed into the bottomed cylindrical portion 42b of the low-pressure bus bar 20a, and the engaging convex portion 48 and the engaging concave portion 50 are fitted, whereby the high-pressure bus bar. 16a and the low-pressure bus bar 20a are joined.

  The connection portion 40 is formed as shown in FIGS. 5 and 6, for example. First, a punch 52 and a die 54 are prepared. The punch 52 has a cylindrical shape, and the distal end portion 56 has a smaller diameter than the proximal end portion 58. The front end surface 60 of the punch 52 is a circular and substantially flat surface. On the other hand, the die 54 has a cylindrical shape, and a recess 64 is formed in the distal end surface 62. The recess 64 has a substantially bottomed cylindrical shape that opens upward (upward in FIG. 6), and the center portion of the bottom surface 66 has a circular and substantially flat shape. An annular groove 68 is formed. The inner diameter of the recess 64 is formed to a predetermined size that is slightly larger than the outer diameter of the front end portion 56 of the punch 52 in consideration of the thicknesses of the high-pressure bus bar 16a and the low-pressure bus bar 20a.

  The overlapping portion 34 of the low-pressure bus bar 20a is placed on the die 54, and the high-pressure bus bar 16a is overlapped on the overlapping portion 34 and fixed in position. In this state, by moving the front end portion 56 of the punch 52 toward the recess 64 of the die 54, the high-pressure bus bar 16a is pushed into the low-pressure bus bar 20a, and the high-pressure bus bar 16a and the low-pressure bus bar 20a are overlapped. Bottomed cylindrical portions 42a and 42b are formed by locally projecting into the recess 64 of the die 54 at the mating portion. The bottomed cylindrical portions 42a and 42b maintain the bottomed cylindrical shape until reaching the bottom surface 66 of the recess 64 of the die 54, and thereafter, when the punch 52 further advances, the bottomed cylindrical portions 42a and 42b spread laterally within the recess 64. It is done. Then, by filling the recess 64 including the annular groove 68 with the material, the engagement convex portion 48 is formed on the bottomed cylindrical portion 42a of the high-pressure bus bar 16a, and the bottomed cylindrical portion of the low-pressure bus bar 20a. An engaging recess 50 is formed in 42b. The high-pressure bus bar 16a and the low-pressure bus bar 20a are joined by fitting the engaging convex portion 48 and the engaging concave portion 50 together.

  Similarly, the low-pressure bus bars 20b, 20c, and 20d are joined to the high-pressure bus bar 16b. Note that three low-pressure bus bars 20b, 20c, and 20d are joined to the high-pressure bus bar 16b. Preferably, a punch 52 and a die 54 are prepared for each of the low-pressure bus bars 20b, 20c, and 20d. Be joined.

  In this way, the high voltage circuit 18 constituted by the high voltage bus bars 16a and 16b and the low voltage circuit 22 constituted by including the low voltage bus bars 20a to 20d and the other low voltage bus bars 20 are mutually connected. Is done. As shown in FIG. 1, the high-pressure bus bar 16 and the low-pressure bus bar 20 are placed on the lower case 14. The lower case 14 is formed with recess-shaped bus bar receiving grooves 70 corresponding to the bus bars 16 and 20, and the bus bars 16 and 20 are placed in the corresponding bus bar receiving grooves 70 in a stored state. In the bus bar housing grooves 70a and 70b in which the high-pressure bus bars 16a and 16b are housed, a retreat for allowing the bottomed cylindrical portions 42a and 42b protruding from the connection portion 40 to escape at positions corresponding to the connection portion 40. A recess 72 is formed. When the high-pressure bus bars 16a and 16b and the low-pressure bus bars 20a to 20d are accommodated in the bus bar accommodating grooves 70, respectively, the high-pressure bus bars 16a and 16b and the low-pressure bus bars 20a to 20d may rotate relative to each other around the connection portion 40. It is prevented. The high-pressure bus bars 16 a and 16 b are set in the lower case 14 with the relay connection portions 30 and 30 bolted to the relay 26 and the stud bolts 74 inserted into the bolt insertion holes 28 and 28. The high-voltage bus bar 16 a is inserted into the current sensor 24 and set in the lower case 14.

  Then, the upper case 12 is covered with the lower case 14, and the lock claws 76 formed at a plurality of locations on the outer peripheral surface of the lower case 14 and the lock pieces 78 formed on the outer wall of the corresponding upper case 12 are engaged with each other. As a result, the lower case 14 and the upper case 12 are assembled to each other. On the upper surface of the upper case 12, a fuse mounting portion 82 to which a fuse 80 is mounted, a resistance mounting portion 86 to which a resistor 84 is mounted, a relay mounting portion 90 to which a relay 88 is mounted, and a connector mounting portion to which a connector is mounted ( Etc.) are provided. Then, by covering the upper case 12 on the lower case 14, the terminal portions 36 provided on the low-pressure bus bars 20 are disposed on the mounting portions 82, 86, 90, etc., and the relay terminals 92 are provided as necessary. And the fuse 80, the resistor 84, the relay 88, the connector, and the like. Note that the terminal portion 36 of the low-pressure bus bar 20 a is disposed in the relay mounting portion 90 and connected to the relay 88. The terminal portion 36 of the low-pressure bus bar 20b is disposed in the connector mounting portion and connected to the connector. The terminal portion 36 of the low-pressure bus bar 20 c is disposed in the resistor mounting portion 86 and connected to the resistor 84. The terminal portion 36 of the low-voltage bus bar 20 d is disposed in the fuse mounting portion 82 and connected to the fuse 80.

  In the high voltage electrical junction box 10 structured according to the present embodiment, the high voltage bus bars 16a and 16b constituting the high voltage circuit 18 and the low voltage bus bars 20a to 20d constituting the low voltage circuit 22 are mechanical clinch. It is connected by the formed connection part 40. Accordingly, the high-pressure bus bars 16a and 16b and the low-pressure bus bars 20a to 20d can be connected with a high contact load without using another component such as a relay terminal. As a result, the contact resistance at the connecting portion 40 can be reduced. Further, since the contact load between the high-pressure bus bar 16 and the low-pressure bus bar 20 can be stably secured and fluctuations in contact resistance can be suppressed, it can be used as a detection bus bar for the current sensor 24 like the high-pressure bus bar 16a. In this case, detection accuracy can be improved.

  Since no separate parts are required for connection between the high-pressure bus bars 16a and 16b and the low-pressure bus bars 20a to 20d, the number of parts can be reduced and the size of the connecting portion 40 can be reduced. As a result, the manufacturing cost of the high-voltage electrical junction box 10 can be reduced, and the weight and size can be reduced. In addition, the high-pressure bus bars 16a and 16b and the low-pressure bus bars 20a to 20d can be efficiently connected as compared to bolting or the like, and a plurality of locations can be connected simultaneously. For example, the high-pressure bus bar 16b By performing mechanical clinching simultaneously on the plurality of low-pressure bus bars 20b, 20c, and 20d to be connected, the manufacturing efficiency can be further improved.

Further, the plate thickness dimension: t _h of the high-pressure bus bar 16 is made larger than the plate thickness dimension: t _l of the low-pressure bus bar 20. As a result, it is possible to secure a current cross-sectional area while suppressing an increase in the width of the high-pressure bus bars 16a and 16b, and to improve the arrangement space efficiency of the high-pressure bus bars 16a and 16b. Then, by pushing from the high-pressure bus bar 16 side having a large plate thickness toward the low-pressure bus bar 20 side having a small plate thickness to form a mechanical clinch, there is a risk that the low-pressure bus bar 20 having a particularly small plate thickness will be broken. This can reduce the risk of molding defects. Further, by forming the overlapping portion 34 of the low-pressure bus bar 20 with the high-pressure bus bar 16 so as to have a wide width, the risk of breakage is further reduced.

  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 number and specific shape of the high-pressure bus bar and the low-pressure bus bar can be appropriately set according to the required circuit wiring shape and the like.

10: High voltage electrical connection box, 16: High voltage bus bar, 18: High voltage circuit, 20: Low voltage bus bar, 22: Low voltage circuit, 24: Current sensor, 26: Relay, 32: Circuit part, 34: Superposition Part, 36: terminal part, 40: connection part, 52: punch, 54: die, 80: fuse, 84: resistance, 88: relay, 92: relay terminal

Claims (4)

In the high-voltage electrical junction box configured to include the high-voltage circuit constituted by the high-pressure bus bar and the low-voltage circuit constituted by the low-pressure bus bar,
While the plate thickness dimension of the high-pressure bus bar is larger than the plate thickness dimension of the low-pressure bus bar,
The connecting portion between the low-pressure bus bar and the high-pressure bus bar is formed by a mechanical clinch that is overlapped with the low-pressure bus bar and pushed from the high-pressure bus bar side to the low-pressure bus bar side. An electrical junction box for high voltage. 2. The high-voltage electrical connection box according to claim 1, wherein the low-pressure bus bar has a wide overlapping portion with the high-pressure bus bar on which the connection portion is formed. The high-voltage electrical connection box according to claim 1 or 2, wherein a plurality of the low-pressure bus bars are connected to one high-pressure bus bar. 4. The high-voltage electrical junction box according to claim 1, wherein at least one of the high-voltage bus bars to which the low-voltage bus bar is connected is inserted into a current sensor.