Bus bar assembly structure

Abstract

To absorb an assembly error of a bus bar and thermal deformation of the bus bar even when the bus bar has high rigidity.SOLUTION: In a bus bar assembly structure, a bus bar for electrically connecting an electrical device and a connector is assembled to a terminal of the electrical device and a connector side bus bar of the connector, the housing that houses the bus bar is fixed to a separate device from the electrical device with the connector assembled, the direction in which the connector is assembled into the housing and the direction in which the bus bar is assembled into the electrical device are the same, the connection part of the bus bar with the connector side bus bar is fastened with a floating nut, a part to be fastened to the terminal of the electrical device is supported by the housing in a movable manner in the assembly direction with respect to the housing, and is bent in the thickness direction of the bus bar.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an assembly structure for a bus bar. [Background technology]

[0002] Patent Document 1 discloses a resin-molded bus bar in which a portion of the bus bar is covered with resin. In this bus bar, the elastic deformation of the bracket absorbs misalignment of the connection portion where the tip of the bracket protruding from the resin mold is connected to the terminal of the electrical device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-158359 Summary of the Invention [Problem to be solved by the invention]

[0004] As the cross-sectional area of a bus bar increases with the increase in the current of electrical devices, the rigidity of the bus bar also increases. However, if the rigidity is increased while the cross-sectional area is sufficient to accommodate the increase in current, there is a risk that the elastic deformation of the bus bar alone will not be able to absorb assembly errors or thermal deformation of the bus bar.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a bus bar assembly structure that can absorb bus bar assembly errors and thermal deformation of the bus bar even when the bus bar has high rigidity. [Means for solving the problem]

[0006] The present invention provides a bus bar assembly structure in which a bus bar that electrically connects an electrical device and a connector is assembled to a terminal of the electrical device and a connector-side bus bar of the connector, wherein a housing that accommodates the bus bar is fixed to a device separate from the electrical device with the connector assembled thereto, the assembly direction of the connector to the housing and the assembly direction of the bus bar to the electrical device are the same, the bus bar has a connection portion with the connector-side bus bar fastened with a floating nut, the portion that is fastened to the terminal of the electrical device is supported by the housing in a state where it can move in the assembly direction relative to the housing, and the bus bar has a structure that bends in the thickness direction of the bus bar. [Effects of the Invention]

[0007] According to the present invention, even when the bus bar has high rigidity, it is possible to absorb assembly errors of the bus bar and thermal deformation of the bus bar. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically illustrating an assembly structure of a bus bar according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a support structure for supporting the bus bars within the housing of the branch box. [Figure 3] FIG. 3 is a diagram schematically showing the support structure including a cross section taken along line AA in FIG. [Figure 4] FIG. 4 is a diagram showing a state before the connector-side bus bar and the branch box-side bus bar are fastened to each other. [Figure 5] FIG. 5 is a diagram showing a fastened state in which the connector-side bus bar and the branch box-side bus bar are fastened together. [Figure 6] FIG. 6 is a diagram illustrating a bus bar structure according to a modified example. [Figure 7] FIG. 7 is a diagram schematically showing the support structure including a cross section taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a bus bar assembly structure according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiment described below.

[0010] 1 is a diagram illustrating a bus bar assembly structure according to an embodiment. The bus bar assembly structure relates to a structure for assembling a bus bar 1 provided in a branch box 10 to a converter 20 and a connector 30.

[0011] The busbar 1 electrically connects the converter 20 and the connector 30, and is also electrically connected to the fuel cell stack 40. The converter 20 is an electrical device on the input side (power source side) of the branching box 10, and is a boost converter that boosts and outputs the power of the fuel cell stack 40. The connector 30 is an electrical device on the output side (supply destination side) of the branching box 10, and is attached to the branching box 10 to connect the supply destination device to the fuel cell stack 40. The branching box 10 is a device that electrically connects multiple devices to the fuel cell stack 40. The power output from the fuel cell stack 40 is supplied to the branching box 10 via the converter 20, and is then supplied from the branching box 10 to the multiple devices via the connector 30. In this way, the branching box 10 outputs the power supplied from the fuel cell stack 40 via the converter 20 to the multiple devices.

[0012] The branch box 10 includes a bus bar 1 and a housing 11.

[0013] The housing 11, with the bus bar 1 housed inside, is fixed to the fuel cell stack 40 by fixing members 50. The housing 11 is integrated with the fuel cell stack 40 by the fixing members 50. The fixing members 50 are formed of, for example, fastening members. The points at which the branch box 10 and the fuel cell stack 40 are fastened by the fixing members 50 become housing fastening points P1.

[0014] The bus bar 1 is fastened to the terminal of the converter 20 while housed inside the housing 11, and is also fastened to the connector side bus bar 31 of the connector 30. This bus bar 1 is configured to include an input side bus bar 2 and an output side bus bar 3. The input side bus bar 2 and the output side bus bar 3 are electrically connected to the bus bar 1. The input side bus bar 2 is a bus bar that is fastened to the terminal of the converter 20. The output side bus bar 3 is a bus bar that is fastened to the connector side bus bar 31 of the connector 30, and is held by a holding portion 12.

[0015] In this bus bar assembly structure, the fastening point of the housing 11 (housing fastening point P1) is the fuel cell stack 40, and the fastening point of the bus bar 1 (electrical wiring fastening point P2) is the terminal of the converter 20. In other words, for the branch box 10, the fastening object of the housing 11 and the fastening object of the bus bar 1 are different. Therefore, the housing fastening point P1 and the electrical wiring fastening point P2 are in different positions. As shown in FIG. 1 , in a structure in which the converter 20 is disposed below the fuel cell stack 40, the fastening point between the housing 11 and the fuel cell stack 40 (housing fastening point P1) is located above the fastening point between the bus bar 1 and the converter 20 (electrical wiring fastening point P2).

[0016] The connector 30 is electrically connected to the busbar 1 when it is attached to the housing 11 of the branching box 10. Although FIG. 1 shows one connector 30 attached to the branching box 10, it is possible to attach a plurality of connectors 30 to the housing 11. For example, a total of three connectors 30 are attached to the branching box 10. In this case, the three connectors 30 are attached to the housing 11 from the same direction.

[0017] The assembly direction of the connector 30 to the housing 11 is the same as the assembly direction of the bus bar 1 to the terminal of the converter 20. For example, when the bus bar 1 is mounted on a vehicle, the assembly direction of the connector 30 to the branch box 10 is the width direction of the vehicle. This is common to all of the multiple connectors 30. The assembly direction of the bus bar 1 to the terminal of the converter 20 is also the width direction of the vehicle. The assembly direction of each connector 30 to the branch box 10 and the assembly direction of the bus bar 1 to the converter 20 are the same direction.

[0018] Furthermore, the input side bus bar 2 of the bus bar 1 is fastened to a terminal of the converter 20 and supported by the housing 11 in a state in which it can move in the assembly direction relative to the housing 11. Furthermore, the output side bus bar 3 of the bus bar 1 is fastened to a connector side bus bar 31 of the connector 30 and is configured to be movable in the assembly direction relative to the connector 30. This movement in the assembly direction includes reciprocating motion. The movable range of the bus bar 1 in the assembly direction is limited to a predetermined range.

[0019] 2 and 3, a support structure for the input bus bar 2 will be described. In this description, the input bus bar 2 can be read as the bus bar 1.

[0020] As shown in Fig. 2, the input bus bar 2 is bolted to the housing 11 via the resin mold 4. The input bus bar 2 is arranged so that the assembly direction is the board width direction, the vertical direction is the extension direction, and the front-to-rear direction is the thickness direction. This input bus bar 2 includes a portion that extends vertically inside the housing 11, and a portion of this portion is covered by the resin mold 4.

[0021] The resin mold 4 is formed to have a thickness in the assembly direction that is greater than the plate width of the input bus bar 2. As shown in Fig. 3, the resin mold 4 is formed to have a width in the front-rear direction that is greater than the thickness of the input bus bar 2. The resin mold 4 is provided with an insertion hole that passes through along the assembly direction (thickness direction), and the fastening boss 61 is loosely fitted into this insertion hole.

[0022] The fastening bosses 61 are fixed to the wall portion 11a of the housing 11 and extend along the assembly direction. Two fastening bosses 61 are provided, one on each side in the thickness direction of the input side bus bar 2 and at different positions in the extension direction of the input side bus bar 2. Two fastening bosses 61 are provided, one on each side of the position of the input side bus bar 2 in the thickness direction of the input side bus bar 2 and at different positions in the extension direction of the input side bus bar 2. A bus bar fixing bolt 62 is screwed into each fastening boss 61.

[0023] The height of the fastening boss 61 is formed to be greater than the thickness of the resin mold 4 in the assembly direction. Furthermore, the resin mold 4 is spaced apart from the wall 11a in the assembly direction and is loosely fitted into the fastening boss 61. The resin mold 4 is supported by the housing 11 via the fastening boss 61 at a position spaced apart from the wall 11a in the assembly direction. In this state, a busbar fixing bolt 62 is fastened to the fastening boss 61. The head 62a of the busbar fixing bolt 62 is located at a position spaced apart from the resin mold 4 in the assembly direction. When the input side busbar 2 reciprocates in a direction parallel to the assembly direction, the resin mold 4 can move integrally with the input side busbar 2.

[0024] Next, the fastening structure of the output side bus bar 3 will be described with reference to Figures 4 and 5. In this description, the output side bus bar 3 can be read as the bus bar 1.

[0025] As shown in Figures 4 and 5, the output side bus bar 3 is formed in a structure extending from the holding portion 12 in a direction parallel to the assembly direction. The holding portion 12 is a member arranged inside the housing 11. The output side bus bar 3 protrudes from the holding portion 12 in a direction parallel to the assembly direction. The output side bus bar 3 is provided with a through hole 3a that opens in an elliptical shape with its elongated direction in the extension direction (direction parallel to the assembly direction). The through hole 3a is an elongated hole that widens in the assembly direction. The connector 30 that is attached to the branch box 10 is of a bolt-fastened type. The connector side bus bar 31 of the connector 30 is provided with a through hole 31a that opens in a perfect circle shape.

[0026] 5, the connector-side bus bar 31 and the bus bar 1 are fastened together by a fixing bolt 71 and a floating nut 72. The fixing bolt 71 is inserted through the through hole 31a of the connector-side bus bar 31 and the through hole 3a of the output-side bus bar 3, and in this state, the floating nut 72 is screwed onto the fixing bolt 71. As a result, the output-side bus bar 3 is fastened to the connector-side bus bar 31 by the floating nut 72. This makes it possible to absorb movement in a direction parallel to the assembly direction of the connector 30 at the connection between the output-side bus bar 3 and the connector-side bus bar 31. In other words, it is possible to achieve a structure that absorbs bus bar deformation due to assembly tolerances of the branch box 10.

[0027] As a modified example of the busbar assembly structure, as shown in Figs. 6 and 7, the portion of the input busbar 2 that is not covered with the resin mold 4 can be folded. As shown in Fig. 7, the input busbar 2 has a structure that is bent in the extension direction. For example, one or more folds 2a are provided in the portion of the busbar 1 that is bent in the extension direction. The folds 2a are formed on the thinner side so that the input busbar 2 can be easily bent in the thickness direction.

[0028] As shown in Fig. 7, the input bus bar 2 has two folds 2a bent in the extension direction (vertical direction) on both sides of the resin mold 4. When the input bus bar 2 expands and deforms due to heat when current is applied, the two folds 2a can absorb the amount of deformation. This allows for a structure that absorbs the deformation force caused by thermal deformation of the input bus bar 2 when current is applied.

[0029] The object to which the housing 11 is fastened may be any device other than the electrical device to which the bus bar 1 is fastened, and is not limited to the fuel cell stack 40. Similarly, the object to which the bus bar 1 is fastened may be any device other than the electrical device to which the housing 11 is fastened, and is not limited to the converter 20.

[0030] Furthermore, the combination of the power supply device and the electrical equipment has been described as including a fuel cell stack 40 and a converter 20, but is not limited to this. The power supply device is not limited to the fuel cell stack 40, and may be other power supply devices. The electrical equipment is not limited to the converter 20 as a converter for a fuel cell system, and may be other power conversion devices. [Explanation of symbols]

[0031] 1 Bus bar 2 Input bus bar 2a crease 3 Output bus bar 3a Through hole 4 Resin mold 10 Branch box 11. Housing 12 Holding part 20 Converter 30 connectors 31 Connector side bus bar 40 Fuel Cell Stack 50 Fixing member 61 Fastening boss 62 Busbar fixing bolt 71 Fixing bolt 72 Floating nut P1 Housing fastening point P2 Electrical wiring connection point

Claims

[Claim 1] A bus bar assembly structure in which a bus bar that electrically connects an electrical device and a connector is assembled to a terminal of the electrical device and a connector-side bus bar of the connector, a branch box provided with the bus bar; a device separate from the electrical device; Equipped with the electrical device is an input-side electrical device with respect to the branch box, the branch box has a housing that houses the bus bar therein, the connector is an output-side electrical device relative to the branch box, and is electrically connected to the bus bar in a state where the connector is assembled to the housing, the housing is fixed to the other device by a fixing member in a state in which the connector is assembled; an assembly direction in which the connector is assembled to the housing is the same as an assembly direction in which the bus bar is assembled to the input-side electrical device; The bus bar is an input side bus bar fastened to the terminal; an output side bus bar fastened to the connector side bus bar and electrically connected to the input side bus bar, The input side bus bar is a first portion fastened to the terminal; a second portion extending in the vertical direction inside the housing and partly covered by a resin mold; the resin mold is gap-fitted into a fastening boss fixed to a wall portion of the housing, and is supported by the housing via the fastening boss at a position spaced from the wall portion, The fastening boss extends along the assembly direction, a connection portion of the output bus bar to the connector bus bar is fastened with a floating nut; Furthermore, the input side bus bar is arranged so that the assembly direction is a plate width direction, the up-down direction is an extension direction, and the front-rear direction is a thickness direction, The second portion has a structure that is supported by the housing via the resin mold and the fastening boss in a state in which the first portion is movable in the assembly direction relative to the housing, and is flexible in the thickness direction. A bus bar assembly structure characterized by the above.

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