Busbar unit fixing method

Abstract

To provide a bus bar unit fixing method which achieves reduction of the number of components, reduction of assembly work hours, and space saving while reducing stress occurring in a connector unit.SOLUTION: In a bus bar unit fixing method, a bus bar unit 10, including a bus bar 20 and a connector unit 30 molded so as to be integrated with the bus bar 20 by insert molding, is fixed to an intermediate member 71 of a housing case 70. The bus bar unit fixing method includes: a first step in which a first bolt 41 is inserted into a first bolt insertion hole 21a of a first end 21 of the bus bar 20 to fasten the first end 21 of the bus bar 20 to a connection terminal 61 of an intelligent power module 60; and a second step in which a second bolt 42 is inserted into a second bolt insertion hole 30a of the connector unit 30 to fix the connector unit 30 to the intermediate member 71 of the housing case 70 after the first step.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a busbar unit fixing method for fixing a busbar unit to a fixed member. [Background technology]

[0002] Efforts aimed at mitigating or reducing the impact of climate change have been ongoing for some time now, and the electrification of drive sources has progressed rapidly in order to achieve this.

[0003] As driving sources become more electrically powered, busbar units are sometimes used as one means for transferring large amounts of electric power between a power storage device such as a battery and the driving source.

[0004] When a busbar unit is used to transmit large amounts of power between a power storage device such as a battery and a drive source, reducing the number of parts, reducing assembly steps, and realizing space saving have a large impact on cost reduction, so it is becoming increasingly important to reduce the number of parts, reducing assembly steps, and realizing space saving for busbar units.

[0005] For example, Patent Document 1 describes a busbar unit in which the strength of a metal plate is increased by providing a bent portion in the metal plate. The busbar unit described in Patent Document 1 makes it possible to apply the force used to fix the flat portion to a device to the sealing member without necessarily increasing the thickness of the metal plate, thereby reducing manufacturing costs and preventing a decrease in sealing performance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-143024 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 does not mention a reduction in the number of parts in the busbar unit, a reduction in assembly steps, or space saving.

[0008] The present invention provides a busbar unit fixing method that can reduce the number of parts, reduce the number of assembly steps, and save space while reducing stress generated in a connector unit. [Means for solving the problem]

[0009] The present invention relates to a bus bar having a first end and a second end and extending from the first end to the second end; a connector unit molded by insert molding so as to be integrated with the bus bar; a first bolt insertion hole through which a first bolt is inserted is formed in the first end of the bus bar; The connector unit is formed with a second bolt insertion hole through which a second bolt is inserted. The bus bar unit is fixed to a fixed member, The first end is connected to a connection terminal provided on an electronic component; A busbar unit fixing method comprising: connecting a cable to the second end portion, a first step of inserting the first bolt into the first bolt insertion hole to fasten the first end of the bus bar to the connection terminal provided on the electronic component; and a second step of, after the first step, inserting the second bolt into the second bolt insertion hole to fix the connector unit to the fixed member. death, the busbar unit and the fixed member are provided with positioning portions that position the busbar unit relative to the fixed member, The positioning portion allows the busbar unit to move relative to the fixed member in a fastening direction of the first bolt in the first step. . Effect of the Invention

[0010] According to the present invention, it is possible to reduce the number of parts, the number of assembly steps, and space while reducing the stress generated in the connector unit. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view of a power control unit to which a bus bar unit according to an embodiment of the present invention is attached, as viewed obliquely from above. [Diagram 2] 1 is a perspective view of a busbar unit according to an embodiment of the present invention, as viewed obliquely from above. [Diagram 3] 3 is a perspective view of the busbar unit of FIG. 2 attached to the power control unit, as viewed obliquely from below. [Figure 4] 3 is a bottom view of the bus bar unit of FIG. 2 attached to the power control unit with a portion of the connector unit omitted. [Diagram 5] 3 is a cross-sectional view of a main portion of the busbar unit of FIG. 2 attached to a power control unit. [Figure 6] 3A to 3C are schematic diagrams illustrating a procedure for attaching the busbar unit in FIG. 2 to the power control unit. [Figure 7] 3 is a flowchart illustrating a procedure for attaching the busbar unit of FIG. 2 to the power control unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a power control unit to which a busbar unit according to an embodiment of the present invention is attached will be described with reference to the accompanying drawings. The drawings are to be viewed in the direction of the reference symbols. In this specification, for the sake of simplicity and clarity, the front-rear, left-right, and up-down directions are defined according to the directions of the power control unit, and in the drawings, the front is indicated as Fr, the rear as Rr, the left as L, the right as R, the upside as U, and the downside as D. Note that the front-rear, left-right, and up-down directions in this specification are merely defined for the sake of simplicity and clarity, and the power control unit may be installed such that the front-rear, left-right, and up-down directions are different from those shown in this specification.

[0013] As shown in FIG. 1, the busbar unit 10 of the present embodiment is attached to a power control unit 50.

[0014] (Busbar unit) As shown in Fig. 2, the busbar unit 10 includes three busbars 20 and a connector unit 30. The three busbars 20 are arranged side by side in the front-rear direction. The three busbars 20 are flat plates extending parallel to one another. Each of the three busbars 20 has a first end 21, a second end 22, and a connection portion 23 connecting the first end 21 and the second end 22, and extends from the first end 21 to the second end 22.

[0015] The first end 21 extends in the up-down direction. The first end 21 is in the shape of a flat plate that is substantially perpendicular to the left-right direction. The first end 21 has a first bolt insertion hole 21a that penetrates in the left-right direction and through which the first bolt 41 is inserted.

[0016] The connecting portion 23 is bent from the upper end of the first end portion 21 and extends diagonally left rearward in a substantially horizontal direction. The connecting portion 23 is in the shape of a flat plate that is substantially perpendicular to the up-down direction (see FIG. 4).

[0017] The second end portion 22 is bent and extends upward from the left rear end of the connection portion 23. The second end portion 22 has a flat plate shape that is approximately perpendicular to the left-right direction.

[0018] The connector unit 30 is molded by insert molding so as to be integrated with the three bus bars 20. More specifically, the three bus bars 20 are inserted into an injection mold, and molten resin is injected around the three bus bars 20, thereby molding the resin connector unit 30 integrated with the three inserted bus bars 20.

[0019] The connector unit 30 has a flange portion 31 extending approximately horizontally and covering at least a portion of the connection portions 23 of the three bus bars 20, and side wall portions 32 extending upward from the upper surface of the flange portion 31 and surrounding the front, rear, left and right of the lower region of the second ends 22 of the three bus bars 20.

[0020] The first end portion 21 is exposed below the flange portion 31. The upper region of the second end portion 22 is exposed above the side wall portion 32.

[0021] The connector unit 30 has a front fastening portion 311 extending forward from a front end portion of the flange portion 31, and a rear fastening portion 312 extending forward from a rear end portion of the flange portion 31. The front fastening portion 311 and the rear fastening portion 312 each have a second bolt insertion hole 30a that penetrates in the vertical direction and through which the second bolt 42 is inserted. The second bolt insertion hole 30a is a circular hole with a diameter larger than the diameter of the shaft portion of the second bolt 42, and has a predetermined play with respect to the second bolt 42.

[0022] The connector unit 30 is provided with a positioning pin 33 that extends downward from the lower surface of the flange portion 31 .

[0023] (Power Control Unit) As shown in FIG. 1 and FIGS. 3 to 5, the power control unit 50 includes an intelligent power module (IPM) 60 and a housing case 70 for housing the intelligent power module 60 therein.

[0024] The intelligent power module 60 is an electronic component equipped with power semiconductor elements incorporating drive circuits for power devices such as power MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and insulated gate bipolar transistors (IGBTs) that control power.

[0025] Near the rear end of the left side surface of the intelligent power module 60, three connection terminals 61 are formed side by side in the front-rear direction.

[0026] The storage case 70 has a front wall portion 701 , a rear wall portion 702 , a left wall portion 703 , a right wall portion 704 , an upper wall portion 705 , and a lower wall portion 706 .

[0027] The housing case 70 has an intermediate member 71 forming at least a part of each of a front wall portion 701, a rear wall portion 702, a left wall portion 703, and a right wall portion 704 of the housing case 70, an upper member 72 arranged on the upper part of the intermediate member 71 and covering the upper side of the intelligent power module 60, and a lower member 73 arranged on the lower part of the intermediate member 71 and covering the lower side of the intelligent power module 60. The upper member 72 is fixed to the upper end portion of the intermediate member 71 by bolts or the like. The lower member 73 is fixed to the lower end portion of the intermediate member 71 by bolts or the like.

[0028] An upper wall portion 705 of the storage case 70 is formed by an upper member 72. A lower wall portion 706 of the storage case 70 is formed by a lower member 73. In each of the front wall portion 701, the rear wall portion 702, the left wall portion 703, and the right wall portion 704 of the storage case 70, the upper region is formed by the upper member 72, the lower region is formed by the lower member 73, and a vertical intermediate region between the upper region and the lower region is formed by the intermediate member 71.

[0029] The intermediate member 71 has a front wall portion 711 , a rear wall portion 712 , a left wall portion 713 , a right wall portion 714 , and a bottom wall portion 715 .

[0030] The intelligent power module 60 is fixed from below to the lower surface 715a of the bottom wall portion 715 of the intermediate member 71 by bolts or the like.

[0031] A bottom wall 715 of the intermediate member 71 is provided with a positioning hole 71b into which a positioning pin 33 formed on the connector unit 30 of the busbar unit 10 can be inserted. The positioning hole 71b is a recess recessed upward from a lower surface 715a of the bottom wall 715 of the intermediate member 71. The positioning hole 71b has an elongated hole shape whose left-right dimension is longer than its front-rear dimension. When inserted into the positioning hole 71b of the intermediate member 71, the positioning pin 33 formed on the connector unit 30 of the busbar unit 10 is substantially immovable in the front-rear direction but is movable a predetermined distance in the left-right direction.

[0032] The bottom wall portion 715 of the intermediate member 71 has bolt fastening holes (not shown) into which the second bolt 42 can be screwed, at positions which overlap with the second bolt insertion holes 30a formed in the front fastening portion 311 and the rear fastening portion 312 of the connector unit 30 when viewed from the top-bottom direction.

[0033] The intermediate member 71 is formed with a three-phase cable connecting portion 71a that passes through the bottom wall portion 715 in the vertical direction and to which a three-phase cable 80 (described later) is connected.

[0034] (Three-phase cable) Three-phase cable 80 includes three electric wires 81, a connector portion 82 that holds one ends of the three electric wires 81, and a connector shell 83 that houses and holds connector portion 82.

[0035] A plug-in terminal portion 81a is provided at one end of each of the three electric wires 81. The plug-in terminal portion 81a provided on each of the three electric wires 81 is formed so as to be able to be externally fitted, by insertion, into the second ends 22 of the three bus bars 20 of the bus bar unit 10. When the plug-in terminal portion 81a provided on each of the three electric wires 81 is externally fitted into the second ends 22 of the three bus bars 20 of the bus bar unit 10, the three-phase cable 80 and the three bus bars 20 of the bus bar unit 10 are electrically connected to each other.

[0036] A seal member 84 is provided on the outer peripheral surface of the connector portion 82. An annular seal groove 82a surrounding the outer peripheral surface of the connector portion 82 on the front, rear, left and right sides is formed, and the seal member 84 is an annular elastic member such as an O-ring, and is disposed in the seal groove 82a of the connector portion 82.

[0037] (Busbar unit fixing method) Next, a busbar unit fixing method for fixing the busbar unit 10 to the accommodating case 70 will be described with reference to FIGS.

[0038] As shown in (a) of FIG. 6, first, with the intelligent power module 60 fixed to the underside 715a of the bottom wall portion 715 of the intermediate member 71 constituting the housing case 70 of the power control unit 50, the intermediate member 71 to which the intelligent power module 60 is fixed is placed so that the underside 715a of the bottom wall portion 715 of the intermediate member 71 faces upward (step S1).

[0039] Next, the busbar unit 10 is placed on the underside 715a of the bottom wall portion 715 so that the positioning pin 33 formed on the connector unit 30 of the busbar unit 10 is inserted into the positioning hole 71b provided in the bottom wall portion 715 of the intermediate member 71 constituting the housing case 70 of the power control unit 50 (step S2).

[0040] Next, the first bolts 41 are inserted from the left into the first bolt insertion holes 21a of the three bus bars 20, and each of the first bolts 41 is screwed into three connection terminals 61 provided on the intelligent power module 60. This fastens the first ends 21 of the three bus bars 20 to the connection terminals 61 provided on the intelligent power module 60 (step S3).

[0041] At this time, the busbar unit 10 is placed on the lower surface 715a of the bottom wall portion 715 with the positioning pins 33 of the busbar unit 10 inserted into the positioning holes 71b provided in the bottom wall portion 715 of the intermediate member 71, and as described above, the positioning pins 33 of the busbar unit 10, when inserted into the positioning holes 71b of the intermediate member 71, are substantially immovable in the front-rear direction but can move a predetermined distance in the left-right direction. Therefore, when fastening the first ends 21 of the three busbars 20 to the connection terminals 61 provided in the intelligent power module 60 in step S3, the connector unit 30 molded by insert molding to be integrated with the three busbars 20 is movable together with the three busbars 20 in the left-right direction, which is the fastening direction of the first bolts 41.

[0042] 6(b), after step S3, second bolts 42 are inserted into the second bolt insertion holes 30a formed in the front fastening portion 311 and the rear fastening portion 312 of the connector unit 30, and each second bolt 42 is screwed into each of the bolt fastening holes (not shown) formed in the bottom wall portion 715 of the intermediate member 71. This fixes the connector unit 30 to the lower surface 715a of the bottom wall portion 715 of the intermediate member 71 that constitutes the housing case 70 of the power control unit 50 (step S4).

[0043] At this time, as described above, the second bolt insertion holes 30a formed in the front fastening portion 311 and the rear fastening portion 312 of the connector unit 30 are circular holes having a diameter larger than the diameter of the shaft portion of the second bolt 42, and have a predetermined play with respect to the second bolt 42. This makes it possible to fix the connector unit 30 to the lower surface 715a of the bottom wall portion 715 of the intermediate member 71 that constitutes the housing case 70 of the power control unit 50, while reducing stress generated in the connector unit 30 and absorbing lateral dimensional variations that occur during the manufacture of the connector unit 30 and the bus bar 20.

[0044] In this manner, with the first ends 21 of the three bus bars 20 fastened to the respective connection terminals 61 provided on the intelligent power module 60 and the connector unit 30 fixed to the underside 715a of the bottom wall portion 715 of the intermediate member 71 constituting the accommodating case 70 of the power control unit 50, it is possible to fix the connector unit 30 to the underside 715a of the bottom wall portion 715 of the intermediate member 71 constituting the accommodating case 70 of the power control unit 50 while reducing stress generated in the connector unit 30 and absorbing variations in the left and right dimensions that occur during the manufacture of the connector unit 30 and the bus bars 20.

[0045] After step S4, the three-phase cable 80 is connected to the second end 22 of each of the three busbars 20 (step S5). In step S5, as shown in FIG. 6(c), the intermediate member 71 to which the intelligent power module 60 and the connector unit 30 of the busbar unit 10 are fixed is turned upside down and placed so that the lower surface 715a of the bottom wall portion 715 of the intermediate member 71 faces downward. Then, the connector portion 82 of the three-phase cable 80 is fitted from above downward into the three-phase cable connecting portion 71a so that the seal member 84 provided on the connector portion 82 of the three-phase cable 80 is in close contact with the inner circumferential surface of the three-phase cable connecting portion 71a formed on the intermediate member 71 of the accommodating case 70. Then, while fitting the connector portion 82 of the three-phase cable 80 into the three-phase cable connecting portion 71a, the plug-in terminal portions 81a formed on one end of each of the three electric wires 81 constituting the three-phase cable 80 are externally fitted into the second ends 22 of the three bus bars 20 from above by insertion. As a result, the plug-in terminal portions 81a formed on one end of each of the three electric wires 81 constituting the three-phase cable 80 are connected to the second ends 22 of the three bus bars 20 (see FIG. 5).

[0046] As described above, according to the busbar unit fixing method of the present embodiment, when electrically connecting the connection terminal 61 of the intelligent power module 60 and the three-phase cable 80, it is not necessary to prepare separate bus bars to be connected to the connection terminal 61 of the intelligent power module 60 and the three-phase cable 80, and the connection terminal 61 of the intelligent power module 60 and the three-phase cable 80 can be electrically connected by one bus bar 20. This makes it possible to reduce the number of parts required when electrically connecting the connection terminal 61 of the intelligent power module 60 and the three-phase cable 80. In addition, since the process of connecting the bus bar to be connected to the connection terminal 61 of the intelligent power module 60 and the bus bar to be connected to the three-phase cable 80 can be omitted, the number of assembly steps can be reduced, and since it is not necessary to secure a tool line when connecting the bus bar to be connected to the connection terminal 61 of the intelligent power module 60 and the bus bar to be connected to the three-phase cable 80, the design freedom of the bus bar is improved and space can be saved.

[0047] In this manner, according to the busbar unit fixing method of the present embodiment, it is possible to reduce the stress generated in the connector unit 30, while reducing the number of parts, the number of assembly steps, and space.

[0048] Furthermore, the connector portion 82 of the three-phase cable 80 is fitted to the three-phase cable connecting portion 71a such that the seal member 84 provided on the connector portion 82 of the three-phase cable 80 is in close contact with the inner circumferential surface of the three-phase cable connecting portion 71a formed on the intermediate member 71 of the housing case 70, so that water or the like can enter the space where the plug-in terminal portion 81a formed on one end of each of the three electric wires 81 constituting the three-phase cable 80 is connected to the second end portion 22 of the busbar 20. In addition, since the seal member 84 is provided on the connector portion 82 of the three-phase cable 80, the seal member 84 is compressed when the connector portion 82 of the three-phase cable 80 is fitted to the three-phase cable connecting portion 71a, so that dimensional variations occurring during the manufacture of the connector unit 30 and the busbar 20 can be absorbed. As a result, the three-phase cable 80 can absorb dimensional variations occurring during the manufacture of the connector unit 30 and the busbar 20, so that stress occurring in the connector unit 30 can be reduced.

[0049] After step S5, the connector shell 83 is fixed to the intermediate member 71 of the accommodating case 70 with bolts or the like (step S6). This completes a series of steps of fixing the busbar unit 10 to the intermediate member 71 of the accommodating case 70, connecting the three-phase cable 80 to the busbar unit 10, and fixing the three-phase cable 80 to the intermediate member 71 of the accommodating case 70.

[0050] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiment may be arbitrarily combined within the scope of the invention.

[0051] This specification describes at least the following items. In parentheses, components corresponding to the above-described embodiment are shown as examples, but the present invention is not limited to these.

[0052] (1) a bus bar (bus bar 20) having a first end (first end 21) and a second end (second end 22) and extending from the first end to the second end; a connector unit (connector unit 30) molded by insert molding so as to be integrated with the bus bar, a first bolt insertion hole (first bolt insertion hole 21a) through which a first bolt (first bolt 41) is inserted is formed at the first end of the bus bar, The connector unit is formed with a second bolt insertion hole (second bolt insertion hole 30a) through which a second bolt (second bolt 42) is inserted. The bus bar unit (bus bar unit 10) is fixed to a fixed member (intermediate member 71 of the accommodating case 70), The first end is connected to a connection terminal (connection terminal 61) provided on an electronic component (intelligent power module 60), A busbar unit fixing method for connecting a cable (three-phase cable 80) to the second end, a first step (step S3) of inserting the first bolt into the first bolt insertion hole to fasten the first end of the bus bar to the connection terminal provided on the electronic component; the busbar unit fixing method further comprising: a second step (step S4) after the first step of inserting the second bolt into the second bolt insertion hole to fix the connector unit to the fixed member.

[0053] According to (1), when the busbar unit is fixed to a fixed member, the stress generated in the connector unit can be reduced, while the number of parts and the number of assembly steps can be reduced, and space can be saved.

[0054] (2) A method for fixing a busbar unit according to (1), comprising the steps of: After the second step, The method further includes a third step (step S5) of connecting the cable to the second end, the cable including an electric wire (electric wire 81), a plug-in terminal portion (plug-in terminal portion 81a) provided at one end of the electric wire, and a connector portion (connector portion 82) that receives the plug-in terminal portion and holds the one end of the electric wire, The connector portion of the cable is provided with a seal member (seal member 84), In the third step, A method for fixing a busbar unit, comprising: fitting the connector portion to the fixed member so that the sealing member of the connector portion is in close contact with the fixed member; and connecting the plug-in terminal portion of the cable to the second end by inserting it into the connector portion.

[0055] According to (2), the dimensional variations that occur during the manufacture of the connector unit and the bus bar can be absorbed by the sealing material of the cable, so that the stress generated in the connector unit can be reduced. [Explanation of symbols]

[0056] 10 Busbar unit 20 Busbar 21 First end 21a First bolt hole 22 Second end 30 Connector unit 30a Second bolt hole 41 First Bolt 42 Second Bolt 60 Intelligent Power Module (electronic component) 61 Connection terminal 70 Storage Case 71 Intermediate member (fixed member) 80 Three-phase cable (cable) 81 Electric wire 81a Plug-in terminal section 82 Connector part 84 Sealing material S1 Step S2 Step S3 Step (1st Step) S4 Step (2nd Step) S5 Step (3rd Step) S6 Step

Claims

1. a bus bar having a first end and a second end and extending from the first end to the second end; a connector unit molded by insert molding so as to be integrated with the bus bar; a first bolt insertion hole through which a first bolt is inserted is formed in the first end of the bus bar; The connector unit has a second bolt insertion hole through which a second bolt is inserted. The bus bar unit is fixed to a fixed member, The first end is connected to a connection terminal provided on an electronic component; A busbar unit fixing method comprising: connecting a cable to the second end, a first step of inserting the first bolt into the first bolt insertion hole to fasten the first end of the bus bar to the connection terminal provided on the electronic component; a second step of, after the first step, inserting the second bolt into the second bolt insertion hole to fix the connector unit to the fixed member, the busbar unit and the fixed member are provided with positioning portions that position the busbar unit relative to the fixed member, The positioning portion allows the busbar unit to move relative to the fixed member in a fastening direction of the first bolt in the first step.

2. The busbar unit fixing method according to claim 1, After the second step, a third step of connecting the cable, the cable including an electric wire, a plug-in terminal portion provided at one end of the electric wire, and a connector portion that receives the plug-in terminal portion and holds the one end of the electric wire, to the second end portion; The connector portion of the cable is provided with a seal member, In the third step, A method for fixing a busbar unit, comprising: engaging the connector portion with the fixed member so that the sealing member of the connector portion is in close contact with the fixed member; and connecting the plug-in terminal portion of the cable to the second end by inserting it into the plug-in terminal portion.

3. The busbar unit fixing method according to claim 1 or 2, The second bolt insertion hole formed in the connector unit is a circular hole having a diameter larger than a diameter of a shaft portion of the second bolt. How to fix the busbar unit.

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