Battery pack

Abstract

The utility model relates to a battery pack, which is characterized in that a battery stack formed by stacking a plurality of battery units is pressed by two side surfaces of a shell from two ends of the stacking direction of the battery units through a gasket body, the battery stack is kept between the two side surfaces of the shell, and the gasket body is provided with an opening part extending along the thickness direction of the gasket body. A protruding part protruding into the opening part of the gasket body is formed on the side face, abutting against the gasket body, of the shell. As a result, displacement of the gasket body in the surface direction of the side surface of the case can be prevented, and the cell stack can be more stably held.

Description

Technical Field

[0001] The utility model relates to a battery pack that accommodates a battery stack formed by stacking a plurality of battery cells. More specifically, it relates to a battery pack structure in which both ends of the battery stack are pressed by side surfaces of a shell to maintain the stacked state of the plurality of battery cells. Background Art

[0002] Various structures have been proposed as battery packs for accommodating a battery stack formed by stacking a plurality of battery cells. For example, Patent Document 1 describes the following structure: a battery array formed by stacking a plurality of battery cells is arranged in an installation space inside a box-shaped housing; an adjustment gasket group consisting of a plurality of adjustment gaskets is sandwiched between the end of the battery array in the stacking direction of the battery cells and the side surface of the housing; a wedge-shaped component is inserted between the end on the opposite side of the battery array and the side surface of the housing to press the battery array and the adjustment gasket group. In addition, Patent Document 2 discloses the following structure: battery cells are arranged on the surface of a flat chassis having three substantially perpendicular walls; a retaining plate is arranged on the surface of the battery cell opposite to the surface in contact with the chassis via an adjustment plate, the edge of which is connected to the wall surface of the chassis, and the retaining plate is fixed by pressing the battery cell against the surface of the chassis.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-528973

[0004] Patent Document 2: International Publication No. 2016 / 189745

[0005] As one of the structures of a battery pack in which a battery stack is housed in a frame (housing), a structure has been proposed in which the battery stack is held between two side surfaces of the frame while being pressed from both ends in the stacking direction of a plurality of battery cells. In the case of this structure, more specifically, Figure 4 As shown, multiple battery cells 2 are first stacked in the thickness direction with resin frames 2a interposed between them. Resin plates 3 and 4 are placed at both ends. In this state, the plates 3 and 4 press and hold the multiple battery cells 2 (see arrow P), tightly affixing the battery cells 2 through the resin frame 2a to form a battery stack 1a. The battery stack 1a is then assembled inside the housing 5 (see arrows S and T) along with a gasket 6 (which may be a stack of multiple gaskets). At this point, the surface of the plates 4 of the battery stack 1a abuts one side 5r of the housing 5, while the plates 3 of the battery stack 1a face the other side 5l of the housing 5 through the gasket 6. The side surfaces 5r and 5l of the housing 5 apply a compressive force to the battery stack 1a and gasket 6 in the stacking direction of the battery cells 2, thereby stably holding the battery stack 1a within the housing 5. Next, a busbar module 7 is placed to electrically connect the multiple battery cells 2, and a cushioning material 8 is placed to press and protect the battery stack 1a from above.

[0006] As described above, in the structure in which the battery stack 1a and the gasket 6 are pressed and held from both sides of the shell 5, when the gasket 6 is adhered with double-sided tape or the like so as not to deviate in the surface direction of the side surface of the shell 5 (when multiple gaskets are stacked, the gaskets are also adhered with double-sided tape), if the gasket 6 is only clamped between the side surface 51 of the shell 5 and the plate 3, then Figure 5 As schematically depicted, when the battery stack 1a is tilted and the pressing force F acting on the battery stack 1a produces a component in the surface direction, sliding occurs at the interface of the double-sided tape of the adhesive gasket 6. Therefore, as shown by the arrow z, the gasket 6 sometimes displaces from the shell 5 in the surface direction, causing the gasket 6 and the battery stack 1a to float from the shell 5. Utility Model Content

[0007] In view of the above situation, the main technical problem to be solved by the present invention is how to prevent the gasket from being displaced in the surface direction of the side surface of the shell in a battery pack in which a battery stack and a gasket formed by stacking multiple battery cells are pressed from both ends of the stacking direction of the battery cells by the two side surfaces of the shell to hold the battery stack in the shell.

[0008] In order to solve the above technical problems, the present utility model adopts the following technical solutions.

[0009] The first technical solution is a battery pack, wherein a battery stack formed by stacking a plurality of battery cells is pressed from both ends of the stacking direction of the battery cells by two side surfaces of the shell through a gasket body, and the battery stack is maintained between the two side surfaces of the shell, the gasket body has an opening extending along its thickness direction, and a convex portion protruding into the opening portion of the gasket body is formed on the side surface of the shell that abuts against the gasket body.

[0010] In the above structure, "battery pack" refers to a substance that is mounted on an electric vehicle or other mechanical device and is used to drive or work, and contains batteries inside the shell. "Battery cell" can be any battery cell used in the art, typically, as described in Figure 4As described, a plurality of battery cells are stacked across a resin frame, and plates made of resin are installed at both ends of the stacking direction to form a battery stack. A "gasket body" can be a flat plate-shaped component formed of any material (resin, metal) that is sandwiched between components for position adjustment in the field. In the present invention, the gasket body can be a single flat plate-shaped component, but can be a material formed by stacking a plurality of gaskets as flat plate-shaped components as described in the embodiment column described later, thereby enabling the thickness of the gasket body to be appropriately changed by adjusting the number of stacked sheets. A "shell" can be a component in the field of the field that is used as a frame and is formed of any material (resin, metal) in a shape upright on a flat plate. The shell can be a die-cast shell (a shell formed by die-casting), but is not limited thereto.

[0011] In the above structure, the gasket body sandwiched between the battery stack and the side surface of the shell has an opening extending in the thickness direction thereof, and a convex portion protruding into the opening is formed on the side surface of the shell to limit the displacement of the gasket body along the surface direction of the side surface of the shell. Therefore, even if a force component in the surface direction of the side surface of the shell is generated on the gasket body due to the inclination of the battery stack, the displacement of the gasket body in the surface direction of the side surface of the shell can be prevented, and the battery pack can be held more stably.

[0012] The second technical solution is that in the above-mentioned first technical solution, the opening portion of the gasket body passes through the gasket body in the thickness direction of the gasket body, and the convex portion on the side of the shell abutting against the gasket body is inserted into the opening portion of the gasket body and extends to the concave portion formed on the surface of the battery stack abutting against the gasket body.

[0013] According to this structure, displacement of the battery stack in the plane direction of the side surface of the case is also restricted, and the battery stack is more stably held in the plane direction of the side surface of the case together with the spacer body.

[0014] The third technical solution is that in the above-mentioned second technical solution, the protruding length of the convex portion on the side of the shell abutting against the gasket body is greater than the thickness of the gasket body and less than the sum of the thickness of the gasket body and the depth of the concave portion of the battery stack.

[0015] According to this structure, the pressing force from the side surface of the case acts reliably on the battery stack, and the battery stack can be held more stably.

[0016] A fourth technical solution is that, in the above-mentioned first technical solution, the gasket body is a stack of a plurality of gaskets, each of the plurality of gaskets has an opening, and the openings of the plurality of gaskets are aligned to form the opening of the gasket body.

[0017] According to a fifth technical solution, in the first technical solution, the housing is a die-cast housing.

[0018] Furthermore, in the present invention, the recessed portion may not be formed on the battery stack. In this case, the convex portion on the side surface of the housing is formed to have a length less than the thickness of the gasket body.

[0019] According to the present invention, in a battery pack structured such that the battery stack, formed by stacking multiple battery cells, and gaskets are pressed against the sides of the housing from both ends of the stacking direction to retain the battery stack within the housing, the gaskets can be prevented from floating, thereby more stably retaining the battery stack within the housing. The battery pack of the present invention can be used in various electric vehicles and other mechanical devices that utilize battery power.

[0020] Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A It is a schematic cross-sectional view of a battery pack to which this embodiment is applied, viewed from the side.

[0022] Figure 1B 1 is a schematic cross-sectional view of a battery pack to which this embodiment is applied, as viewed from above.

[0023] Figure 2A It is a schematic front view of the side surface of the case of the battery pack to which this embodiment is applied, which is in contact with the gasket.

[0024] Figure 2B Schematic diagram of the top view of the gasket.

[0025] Figure 3A This is a schematic cross-sectional view from above of a state before the case, the gasket, and the battery stack are connected in one form of the present embodiment.

[0026] Figure 3B is with Figure 3A Schematic cross-sectional view from above of the corresponding housing, gasket and battery stack after connection.

[0027] Figure 3C This is a schematic cross-sectional view from above of another form of the present embodiment showing a state in which the housing, the gasket, and the battery stack are connected.

[0028] Figure 4 This is a diagram of a battery pack for illustrating a structure in which a battery stack is held between two side surfaces of a frame by pressing and clamping the battery stack from both ends in the stacking direction of the multiple battery cells. The diagram respectively shows a state in which multiple battery cells are arranged in the thickness direction for stacking the multiple battery cells, a battery stack formed by stacking the multiple battery cells, a gasket and a shell, and a state in which the battery pack and the gasket are arranged in the shell.

[0029] Figure 5 It is a schematic cross-sectional view from the side, illustrating a state in which a gasket in the prior art floats from a state in which a housing, a gasket, and a battery pack are connected. DETAILED DESCRIPTION

[0030] Hereinafter, some preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same parts.

[0031] First, the configuration of the battery pack will be described.

[0032] Reference Figure 1A 、 Figure 1B In the battery pack 1 of this embodiment, Figure 4 Similarly to the battery pack of the form illustrated in the figure, a plurality of battery cells 2 are stacked in the thickness direction with a resin frame 2a therebetween to form a battery stack 1a. The battery stack 1a, together with a gasket 6 arranged at at least one end, is arranged in a state pressed by the two side surfaces 51 and 5r of the shell 5 and is held between the two side surfaces 51 and 5r of the shell 5. The battery cell 2 can be any battery cell used in the art, and the resin frame 2a can be a component commonly used as a resin component between the battery cells 2. In addition, plates 3 and 4 made of insulating resin material are usually installed at both ends of the battery stack. The shell 5 can typically be a metal shell cast using die-casting technology. Specifically, as shown in the figure, it can be a frame formed by uprightly forming side surfaces around a flat plate-shaped component. As shown in the figure, the gasket 6 can typically be a plurality of resin or metal flat plate-shaped components stacked together, and the number of sheets can be adjusted according to the size of the interval between the gaskets 6 (the gasket 6 can be single, in which case it also falls within the scope of this embodiment). In addition, when the spacer 6 is formed by laminating a plurality of flat plate-shaped members, they can be bonded to each other using double-sided tape.

[0033] Next, a configuration for restricting displacement of the gasket in the surface direction of the side surface of the housing will be described.

[0034] In the structure of the battery pack 1 described above, in the case of this embodiment, as shown in FIG. Figure 2A 、 Figure 2B As can be understood, an opening 6a is formed in the gasket 6 along its thickness, and a protrusion 5a is formed on the side surface 51 of the housing. When the gasket 6 is positioned between the side surface 51 of the housing and the plate 3 of the battery stack 1a, the protrusion 5a is aligned with and inserted into the opening 6a of the gasket 6. This restricts displacement of the gasket 6 along the side surface 51 of the housing. Thus, even if the battery stack 1a tilts slightly, generating a force component along the side surface 51 of the housing, the gasket maintains its position, maintaining a more stable retention of the battery stack within the housing.

[0035] Regarding the structure in which the opening 6a is formed on the gasket 6 and the convex portion 5a is formed on the side surface 51 of the housing so as to be inserted into the opening 6a, in one embodiment, it can be as follows. Figure 1A 、 Figure 1B It is formed as follows: the opening 6a of the gasket 6 passes through the gasket 6 in the thickness direction, and on the other hand, a recess 3a is formed on the plate 3 of the battery stack in alignment with the opening 6a, and the convex portion 5a of the side surface 51 of the shell passes through the opening 6a of the gasket 6 and extends to the recess 3a of the plate 3 of the battery stack. As a result, the recess 3a of the plate 3 also limits the displacement of the gasket 6 in the surface direction of the side surface 51 of the shell, and the plate 3 and the gasket 6 are in contact and tightly attached to each other, so that the gasket 6 can be more stably maintained on the side surface 51 of the shell. In addition, in this case, as Figure 3A As shown schematically, when the gasket 6 is arranged on the side surface 51 of the housing and the plate 3 is arranged thereon (see arrow x), the top of the convex portion 5a of the side surface 51 of the housing passes through the opening 6a of the gasket 6 and reaches the concave portion 3a of the plate 3 (see arrow y). At this time, it is preferred that Figure 3B As shown, the protrusion 5a is formed so that its protruding length a is smaller than the sum of the thickness c×N (N: number of gaskets) of the gasket 6 and the depth b of the recess (a <c×N+b)。

[0036] According to this structure, the pressing force from the side 51 of the shell toward the plate 3 is transmitted through the gasket 6, and the gasket 6 is also reliably subjected to the pressing force from both sides thereof. In this way, the battery stack and the gasket 6 can be more stably kept from being displaced relative to the side 51 of the shell.

[0037] In another embodiment, when no recess is formed in the plate 3, the protrusion 5a of the side surface 51 of the housing is formed so that its protruding length a is less than or equal to the thickness c×N of the gasket 6. In this case, displacement of the gasket 6 in the surface direction of the side surface 51 of the housing is also prevented, and the gasket 6 can be prevented from floating from between the side surface 51 of the housing and the plate 3.

[0038] Thus, in the configuration of the present embodiment described above, in the case of a battery pack in which a battery stack formed by stacking a plurality of battery cells and a gasket is pressed from both ends of the stacking direction of the battery cells by the two side surfaces of the housing, and the battery stack is retained within the housing, the gasket is prevented from floating, and the battery stack can be retained in the housing more stably. In this regard, in the case of the battery pack that is the subject of the present embodiment, in order to ensure the performance of retaining the wound body of the battery cells and preventing the increase in resistance, a certain load needs to be applied to the battery cells. This load is determined by the spring constant of the housing and the distance between the side surfaces. Since there is a certain degree of deviation in the size of the battery stack sandwiched between the side surfaces of the housing, in order to compensate for this, a gasket is sandwiched between the side surfaces of the housing and the battery stack to adjust the load applied to the battery cells. According to the present embodiment, it is advantageous in that the function of the gasket is not impaired and the gasket is prevented from shifting. The battery pack of the present embodiment is advantageously used for driving or operating the drive device of an electric vehicle or other mechanical equipment.

[0039] The above is an explanation of the embodiments of the present invention, but many modifications and changes can be easily made by those skilled in the art. It is obvious that the present invention is not limited to the embodiments illustrated above, but can be applied to various devices without departing from the concept of the present invention.

Claims

1. A battery pack, characterized in that: The battery stack formed by stacking a plurality of battery cells is pressed by the two side surfaces of the shell from both ends of the stacking direction of the battery cells through the gasket body, and the battery stack is held between the two side surfaces of the shell. The gasket body has an opening extending in a thickness direction thereof, and a convex portion protruding into the opening of the gasket body is formed on a side surface of the housing that contacts the gasket body.

2. The battery pack according to claim 1, wherein: The opening of the gasket body penetrates the gasket body in the thickness direction of the gasket body. The convex portion on the side surface of the housing that contacts the gasket body is inserted through the opening of the gasket body and extends to a concave portion formed on the surface of the battery stack that contacts the gasket body.

3. The battery pack according to claim 2, wherein: The protruding length of the convex portion on the side surface of the housing abutting against the gasket body is greater than the thickness of the gasket body and less than the sum of the thickness of the gasket body and the depth of the concave portion of the battery stack.

4. The battery pack according to claim 1, wherein: The gasket body is a stack of a plurality of gaskets. Each of the plurality of gaskets has an opening. The openings of the plurality of gaskets are aligned to form the opening of the gasket body.

5. The battery pack according to claim 1, wherein: The housing is a die-cast housing.

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