Battery unit

Abstract

To prevent a bus bar from coming into contact with a member leading to a short circuit even when a connection structure of the bus bar collapses.SOLUTION: There is provided a battery unit including a battery module 3, a bus bar 10 through which electric power input to and output from the battery module 3 flows, a first component (JB main body 20) that supports, from below, a member (junction box 1) to which the bus bar 10 is connected in the battery module 3, and a second component (bus bar support portion 30) that is attached to the first component (JB main body 20) and has a bus bar recess 35 located below the bus bar.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery unit. [Background technology]

[0002] A battery unit (also called a "battery pad") has been developed that includes a battery module with multiple battery cells and a junction box placed between the battery module and the motor. The input and output of power between the battery module and the motor is controlled by the on / off operation of a relay installed inside the junction box. In addition, bus bars are used in the power paths between each element within the battery unit and external elements such as the motor to withstand large currents.

[0003] Patent Document 1 describes a technique for stably connecting a battery module and a bus bar. Specifically, in the technique disclosed in Patent Document 1, the bus bar is attached to the battery module using a heat-resistant insulating member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Utility Model No. 220510205 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, if the busbar connection structure collapses, there is a risk that the part not supported by the heat-resistant insulating material will fall and come into contact with a material that could lead to a short circuit, so a new technology was needed.

[0006] An example of an object of the present invention is to provide a technique for preventing a bus bar from coming into contact with a member that could lead to a short circuit, even if the connection structure of the bus bar is broken. [Means for solving the problem]

[0007] The present invention provides the following techniques. 1. A battery module; a bus bar through which power flows to be input to and output from the battery module; a first component that supports, from below, a member to which the bus bar is connected in the battery module; a second component having a busbar recess located below the busbar; A battery unit having: 2. The battery unit according to claim 1, wherein the second component has higher heat resistance than the first component. 3. The battery unit according to 1. or 2., wherein the lower surface of the first component is made of a thermoplastic resin and the second component is made of a thermosetting resin. 4. The battery module has a junction box equipped with a relay circuit; the bus bar is connected to the junction box; the first component is a housing of the junction box; The battery unit according to any one of 1. to 3., wherein the second component has a support portion that is positioned below the bus bar and that includes the bus bar recess. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technique for preventing the bus bar from coming into contact with a member that may lead to a short circuit, even if the connection structure of the bus bar is broken. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a partial perspective view of a battery unit according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing a state in which a JB main body is attached to a module body of a battery module according to an embodiment. [Figure 3] FIG. 2 is a perspective view showing a state in which a bus bar support portion is attached to a JB main body according to an embodiment. [Figure 4] 1 is a plan view showing a state in which bus bar supports are attached to a JB body according to an embodiment. [Figure 5] FIG. 2 is a perspective view showing a state in which a bus bar support portion is attached to a JB main body according to an embodiment, as viewed from below. [Figure 6] FIG. 5 is a cross-sectional view taken along the line A1-A1 in FIG. 4 according to the embodiment. [Figure 7] FIG. 2 is a bottom view of the JB body according to the embodiment. [Figure 8] FIG. 2 is a perspective view of the JB body as seen from below according to the embodiment. [Figure 9] FIG. 2 is a perspective view of a bus bar support according to the embodiment. [Figure 10] FIG. 4 is a plan view of a bus bar support portion according to the embodiment. [Figure 11] FIG. 4 is a side view of a bus bar support according to the embodiment. [Figure 12] FIG. 2 is a perspective view of a bus bar according to an embodiment. [Figure 13] FIG. 2 is a plan view of a bus bar according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and the description thereof will be omitted as appropriate. In this embodiment, in the connection structure between the battery module and the bus bar, even if the component to which the bus bar is connected is deformed due to high temperature or the like, causing the connection structure to collapse, the bus bar is prevented from coming into contact with other components and causing a short circuit.

[0011] FIG. 1 is a partial perspective view of a battery unit 100 according to an embodiment. FIG. 2 is a perspective view showing a state in which a JB body 20 is attached to a module cover 3a of a battery module 3, and is a view in which the JB cover 4 has been removed from the state shown in FIG. 2. FIG. 3 is a perspective view showing a state in which a busbar support portion 30 is attached to the JB body 20. FIG. 4 is a plan view showing a state in which the busbar support portion 30 is attached to the JB body 20. FIG. 5 is a perspective view showing a state in which the busbar support portion 30 is attached to the JB body 20, as viewed from below. FIG. 6 is a cross-sectional view taken along line A1-A1 of FIG. 4, showing the connection state between the JB body 20 and the busbar support portion 30. Fig. 7 is a bottom view of the JB body 20. Fig. 8 is a perspective view of the JB body 20 as seen from below. Fig. 9 is a perspective view of the busbar support portion 30. Fig. 10 is a plan view of the busbar support portion 30. Fig. 11 is a side view of the busbar support portion 30. Fig. 12 is a perspective view of the busbars 10 (first busbar 10a, second busbar 10b). Fig. 13 is a plan view of the busbars 10 (first busbar 10a, second busbar 10b).

[0012] In the drawings, an arrow indicating the X, Y, or Z direction indicates that the direction from the base end of the arrow to the tip is the positive direction of the arrow, and that the direction from the tip of the arrow to the base end is the negative direction of the arrow. Furthermore, a white circle with a black dot indicating the X, Y, or Z direction indicates that the direction from the back of the paper to the front is the positive direction of the arrow, and that the direction from the front of the paper to the back is the negative direction of the arrow. Furthermore, a white circle with an X indicating the X, Y, or Z direction indicates that the direction from the front of the paper to the back is the positive direction of the arrow, and that the direction from the back of the paper to the front is the negative direction of the arrow.

[0013] In the drawing, the X direction is a direction parallel to the horizontal direction that is perpendicular to the vertical direction. For example, the positive X direction is the direction from the rear to the front of the battery unit 100. The Y direction is a direction parallel to the horizontal direction and perpendicular to the X direction. For example, the positive Y direction is the direction from left to right when viewed from the front of the battery unit 100. The Z direction is a direction parallel to the vertical direction. The positive Z direction is the direction from bottom to top. The negative Z direction is the direction from top to bottom. Note that the relationship between the vertical or horizontal direction and the X, Y, or Z direction of the battery unit 100 is not limited to the example described above. The relationship between the vertical or horizontal direction and the X, Y, or Z direction of the battery unit 100 may differ from the example described above depending on the arrangement of the battery unit 100. For example, the X direction may be parallel to the vertical direction, and the Y and Z directions may be parallel to the horizontal direction.

[0014] <Overview of Battery Unit 100> An overview of a battery unit 100 of this embodiment will be described mainly with reference to FIGS. The battery unit 100 includes a battery module 3, a junction box 1, a bus bar 10, and a bus bar support 30. In this embodiment, the battery module 3 is shown with module bodies 3b and 3c and a module cover 3a, which are the portions (part of the housing) to which the junction box 1 is attached, and the battery cells and other components housed inside the housing are omitted. The battery unit 100 is connected to external elements such as a motor via the bus bar 10, but these external elements are omitted here.

[0015] The module bodies 3b, 3c and module cover 3a of the battery module 3 are formed from, for example, metal plates such as aluminum plates or resin plates, and house multiple battery cells inside. Furthermore, exposed portions of the housing (module bodies 3b, 3c and module cover 3a) near electrical components such as bus bars 10 are preferably insulated to prevent short circuits. In the case of aluminum plates, insulation can be ensured by, for example, anodizing the surface or providing a resin coating.

[0016] The junction box 1 is fixed with screws to a module cover 3a that forms the top surface of the battery module 3. In addition, a unit cover (not shown) is attached to the top surface of the junction box 1.

[0017] <Busbar 10> The busbars 10 are conductive, plate-shaped metal members that electrically connect the battery modules 3 together and between the battery modules 3 and external elements (not shown) such as a motor. In this embodiment, the busbars 10 are connected via the junction box 1. From the perspective of contact protection for high-voltage parts, a busbar holder (not shown) may be provided to cover the connection portion between the busbars 10 and the junction box 1 (connection end 11 of the busbars 10) from above.

[0018] The busbar 10 includes a first busbar 10a and a second busbar 10b. The first busbar 10a is connected to the positive electrode of the battery module 3, for example, via a junction box 1. The second busbar 10b is connected to the negative electrode of the battery module 3, for example, via the junction box 1.

[0019] In this embodiment, the first bus bar 10a extends from the connection end portion 11 in the front diagonally downward direction (the positive direction of the X direction and the negative direction of the Z direction), and further extends in the front diagonally downward direction (the positive direction of the Y direction and the negative direction of the Z direction) in a state of being spaced apart from the module body 3c which is the front housing of the battery module 3 along the plate surface, and furthermore, the plate surface is horizontal and extends in the right direction in a front view. The second bus bar 10b extends from the connection end portion 11 in the front diagonally downward direction (the positive direction of the X direction and the negative direction of the Z direction), and further extends in the downward direction (the negative direction of the Z direction) in a front view in a state of being spaced apart from the module body 3c which is the front housing of the battery module 3 along the plate surface, and furthermore, the plate surface extends in the right direction in a front view while remaining along the module body 3c. Note that the shape of the illustrated bus bar 10 (the first bus bar 10a and the second bus bar 10b) is an example, and various shapes are adopted in consideration of the position of the connection destination and the arrangement of other components in the connection path.

[0020] <Junction box 1> The junction box 1 has a generally box shape, and as described above, two bus bars 10 (here, the first bus bar 10a and the second bus bar 10b) are connected side by side on the front side in the X direction. The junction box 1 includes a JB main body 20 and a JB cover 4. The size of the junction box 1 is appropriately selected according to the specifications of the battery module 3.

[0021] <JB main body 20> JB body 20 has a resin housing in which electrical components (not shown), such as relay circuits and voltage detection circuits, and other electrical components are arranged. Bus bar 10 is connected to the electrical components. In this embodiment, the JB body 20 is shown as a resin housing, and the electrical components are not shown. Also, JB body 20 is provided with elements such as ribs, openings, and resin hollows for attaching the electrical components, but these are not shown here. In other words, the housing of JB body 20 supports from below the member to which bus bar 10 is connected. Also, the underside of JB body 20 is provided with a fitting structure (recessed or protruding portion) for attaching bus bar support 30. The manner in which JB body 20 and bus bar support 30 are attached will be described later.

[0022] The JB body 20 is formed of, for example, a thermoplastic resin. The thermoplastic resin is not particularly limited, but examples include polyethylene, polystyrene, polyacrylonitrile, acrylonitrile-styrene (AS) resin, acrylonitrile-butadiene-styrene (ABS) resin, polypropylene, methacrylic resin, polyethylene terephthalate, polyamide, polycarbonate, polyacetal, polyphenylene ether, polybutylene terephthalate, polyether ether ketone, polyetherimide, polyamideimide, polyimide, and polyphthalamide. Using a thermoplastic resin reduces the manufacturing cost of JB body 20. JB body 20 need not be entirely made of a thermoplastic resin; a portion of the body may be made of a thermosetting resin. However, it is preferable that bottom surface 21 of JB body 20 be made of a thermoplastic resin.

[0023] <Busbar support portion 30> 1 to 5, the busbar support 30 is attached to the junction box 1. More specifically, the busbar support 30 is attached to the bottom surface 21 of the JB body 20.

[0024] The busbar support portion 30 may be configured as a single component using one element, or may be configured as a single component by combining a plurality of elements.

[0025] As shown in FIGS. 9 to 11, the busbar support 30 has a support joint surface 31, a support body 32, a support erection surface 33, and a support rib .

[0026] The support joint surface 31 is a plate-shaped portion attached to the bottom surface 21 of the JB body 20. For example, as shown in FIG. 5 , the support joint surface 31 is attached so as to cover the bottom surface 21 on the front side of the JB body 20. That is, it is provided on the bottom surface 21 near the portion where the busbar 10 is connected. Generally, in the junction box 1, the connection portions of the busbar 10 and various electrical components tend to generate heat and become hotter than other areas. Therefore, by attaching the busbar support 30, which is made of a material that is more heat-resistant than the JB body 20, to such locations, it is possible to prevent the heat from affecting the connection structure of the busbar 10, i.e., to prevent the busbar 10 from falling off.

[0027] An upper surface 36 of the support joint surface 31 is provided with a mating protrusion 40 as a structure for attaching the busbar support to the JB body 20. The mating protrusion 40 fits into a mating recess 25 provided on the bottom surface 21 of the JB body 20. The manner in which the JB body 20 and the busbar support 30 are attached will be described later.

[0028] The support portion erection surface 33 is an erect portion at the front end of the support portion joint surface 31, and when attached to the JB main body 20, extends upward a predetermined length along the front side surface of the JB main body 20.

[0029] The support body 32 is a plate-like member substantially parallel to the XY plane, provided at the upper end of the support erection surface 33 so as to extend outward (in the positive X direction (frontward)) with respect to the junction box 1. The support body 32 is substantially rectangular in shape with its longitudinal direction extending in the left-right direction (Y direction) when viewed from above.

[0030] The support body 32 has a busbar recess 35 that is recessed downward. The busbar recess 35 has a first recess 35a and a second recess 35b, which are spaced a certain distance apart in the left-right direction. Specifically, when the busbars 10 (first busbar 10a, second busbar 10b) are attached to the junction box 1, the busbar recess 35 is located a certain distance below the busbars 10 (more specifically, the connection end portions 11). That is, the first recess 35a is located below the first busbar 10a, and the second recess 35b is located below the second busbar 10b.

[0031] The width (left-right dimension) of the busbar recess 35 is slightly wider than the width of the busbar 10 (more specifically, the width of the connection end 11) located above it. That is, the width of the first recess 35a is wider than the width of the first busbar 10a. Also, the width of the second recess 35b is wider than the width of the second busbar 10b.

[0032] When the busbar 10 is properly connected to the junction box 1, the busbar recess 35 and the busbar 10 are spaced apart by a certain distance. Even if the connection between the busbar recess 35 and the busbar 10 is broken, causing the busbar 10 to fall and no longer have a member to directly support it, the busbar recess 35 can catch the busbar 10 and prevent it from falling any further. Furthermore, by providing a busbar recess 35 for each busbar 10, i.e., by providing a first recess 35a and a second recess 35b corresponding to the first busbar 10a and the second busbar 10b, respectively, it is possible to prevent adjacent busbars 10 (the first busbar 10a and the second busbar 10b) from coming into contact with each other.

[0033] The bus bar support portion 30 is, for example, a cured product of a resin composition. As the resin composition, for example, a thermosetting resin can be used. The thermosetting resin is not particularly limited, and examples thereof include phenolic resins such as novolak type phenolic resins and resol type phenolic resins; epoxy resins such as bisphenol type epoxy resins and novolak type epoxy resins; nitrogen-containing resins such as aniline resins, melamine resins, urea resins, and cyanate resins; ketone resins; unsaturated polyester resins; urethane resins or furan resins, etc. Further, these may be modified products modified with various components. The thermosetting resin appropriately contains an inorganic filler (such as a filler) and other materials. By using a thermoplastic resin, high heat resistance can be realized as a resin molded product. Adjustment of the heat resistance can be achieved, for example, by adjusting the type and content of an inorganic filler (such as a filler). Note that the material of the bus bar support portion 30 is not limited to the resin composition, and any material that can provide heat insulation and insulation may be used. For example, a mica board or a composite material of a mica board and a thermosetting resin can be used. As a specific heat resistance of the bus bar support portion 30, assuming that an abnormality occurs in the battery unit 100 and heat is generated, as an example, a material that does not collapse in shape and maintains a certain rigidity at 800 ° C can be used.

[0034] <BB本体20とバスバー支持部30の接続構造> Mainly referring to FIGS. 7 to 13, the connection structure (fitting structure) between the JB main body 20 and the bus bar support portion 30 will be described. In the present embodiment, the JB main body 20 and the bus bar support portion 30 are attached by the two fitting structures described below. However, the aspects (number, position, structure, etc.) of the fitting portions are examples, and aspects other than the description may be used. In addition to the above fitting structure, for the connection between the JB main body 20 and the bus bar support portion 30, for example, fixing with an adhesive member or fixing with a bolt can be used.

[0035] In the JB body 20, a fitting recess 25 is formed in the vicinity of the front side of the bottom surface 21. As the fitting recess 25, a first fitting recess 25a and a second fitting recess 25b are formed side by side in the left - right direction (Y - direction).

[0036] On the support - part joint surface 31 of the bus - bar support part 30, a fitting convex part 40 is formed in the vicinity of the support - part standing surface 33. As the fitting convex part 40, a first fitting convex part 40a and a second fitting convex part 40b are formed side by side in the left - right direction (Y - direction).

[0037] When the bus - bar support part 30 is attached to the JB body 20, the first fitting convex part 40a fits into the first fitting recess 25a, and the second fitting convex part 40b fits into the second fitting recess 25b.

[0038] In the present embodiment, as an example, the first fitting convex part 40a and the second fitting convex part 40b have the same shape. The fitting convex part 40, as an example, has convex parts 41, 42 provided at both ends in the front - rear direction and a recess 43 provided between them. The length of the fitting convex part 40 in the front - rear direction is slightly shorter than the length of the fitting recess 25 in the front - rear direction (X - direction). On the other hand, by adopting a structure in which the fitting convex part 40 has convex parts 41, 42 at both the front and rear ends, it can be fitted into the fitting recess 25 relatively easily, and the fitting state can be maintained. Also, it is relatively easy to remove the bus - bar support part 30 from the JB body 20.

[0039] Also, in a resin - molded product such as the JB body 20, by hollowing out the resin material, a balance between strength and weight reduction is achieved. That is, there may be a recess formed by hollowing out on the bottom surface 21 of the JB body 20. Therefore, by using the recess formed by hollowing out in the connection structure (fitting structure) with the bus - bar support part 30, it is not necessary to make a design change even when using the existing JB body 20. <(Heat resistance of the JB body 20 and the bus - bar support part 30)> ​When comparing the heat resistance of the JB body 20 and the busbar support 30, the busbar support 30 has higher heat resistance. High heat resistance means that the temperature at which the shapes of the JB body 20 and the busbar support 30, which are resin molded products, change is high. For example, the temperature at which the busbar support 30 changes shape is 20°C or more higher, preferably 30°C or more higher, and more preferably 50°C or more higher. The heat resistance can be evaluated, for example, by the melting point, glass transition temperature Tg, and heat distortion temperature (HDT) of the resin material. The heat distortion temperature (HDT) is measured, for example, in accordance with ASTM D648.

[0041] By making busbar support portion 30 more heat resistant than JB body 20, even if the connection between JB body 20 and busbar 10 breaks down due to high temperature, busbar support portion 30 maintains its shape and can catch busbar 10, preventing it from falling further. This prevents busbar 10 from coming into contact with another component and causing a short circuit.

[0042] <Modification> The present invention has been described above based on the above-described embodiment, but the present invention is not limited to the above-described embodiment and various modifications can be adopted. For example, the component to which the bus bar is connected may be a component other than a junction box. Specifically, the bus bar may be used as a connection terminal that connects battery modules 3 together. Even in this case, by providing a bus bar support portion below the bus bar, even if the bus bar connection state is broken, the bus bar support portion can receive the bus bar, preventing the bus bar 10 from falling further and preventing a short circuit. Furthermore, busbar support 30 may be attached to a separate component rather than JB body 20. Even in this case, busbar support 30 has busbar recess 35 formed therein so as to be positioned below busbar 10. In this case, however, a heat-resistant sheet having a structure similar to that of fitting protrusion 40 is attached to the underside of JB body 20.

[0043] Below, examples of reference forms are added. 1. A battery module 3; a bus bar 10 through which power flows to be input to and output from the battery module 3; a first component (JB body 20) that supports from below a component (junction box 1) to which the bus bar 10 is connected in the battery module 3; a second component (busbar support portion 30) having a busbar recess 35 located below the busbar 10; A battery unit 100 having the same. 2. The battery unit 100 according to 1, wherein the second component (busbar support 30) has higher heat resistance than the first component (JB body 20). 3. The battery unit 100 according to 1. or 2., wherein the first component (JB body 20) is made of a thermoplastic resin, and the second component (bus bar support portion 30) is made of a thermosetting resin. 4. The battery module has a junction box equipped with a relay circuit; the bus bar is connected to the junction box; the first component is a housing of the junction box; The battery unit according to any one of 1. to 3., wherein the second component has a support portion that is positioned below the bus bar 10 and that includes the bus bar recess. [Explanation of symbols]

[0044] 1 junction box 3 Battery Module 4 JB Cover 5 Busbar holder 10 Busbar 10a 1st bus bar 10b Second bus bar 20 JB body 21 Bottom 25. Mating recess 30 Busbar support 31 Support joint surface 32 Support body 33 Support part standing surface 34 Support rib 35 Busbar recess 35a First recess 35b Second recess 40 mating protrusion 41, 42 Convex parts 43 Recess

Claims

1. A battery module; a bus bar through which power flows to be input to and output from the battery module; a first component that supports, from below, a member to which the bus bar is connected in the battery module; a second component having a bus bar recess located below the bus bar; A battery unit having:

2. The battery unit according to claim 1 , wherein the second component has a higher heat resistance than the first component.

3. The battery unit according to claim 1 or 2, wherein the first component is made of a thermoplastic resin and the second component is made of a thermosetting resin.

4. the battery module has a junction box equipped with a relay circuit; the bus bar is connected to the junction box; the first component is a housing of the junction box, The battery unit according to claim 1 or 2, wherein the second component has a support portion that is positioned below the bus bar and that includes the bus bar recess.

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