Battery pack

Abstract

A battery pack (10) according to the present disclosure is provided with a battery pack (30), a lower case (21), an upper case (22), and a bus bar module (40), the bus bar module (40) being provided with an external connection positive electrode terminal (45P) and an external connection negative electrode terminal (45N), and an external connection connector (50) being pre-attached to a side wall (22B) of the upper case (22). The external connection connector (50) is provided with an external connection positive electrode bus bar (52), one end of which is fastened to an external connection positive electrode terminal (45P), and an external connection negative electrode bus bar (53), one end of which is fastened to an external connection negative electrode terminal (45N). The upper case (22) is attached to the lower case (21) such that one end of the external connection positive electrode bus bar (52) and the external connection positive electrode terminal (45P) are arranged so as to be able to be fastened, and one end of the external connection negative electrode bus bar (53) and the external connection negative electrode terminal (45N) are arranged so as to be able to be fastened.

Description

Technical Field

[0001] The present disclosure relates to a battery pack. Background Art

[0002] As a battery pack for automobiles, a battery pack described in Japanese Patent Gazette No. 2020-87913 (hereinafter referred to as Patent Document 1) is known. The battery pack includes a shell, a cover, a battery assembly and an end assembly. The shell has a first containment chamber, the cover covers the shell, and the cover has a second containment chamber. The battery assembly is contained in a sealed space consisting of a first containment chamber and a second containment chamber. The end assembly includes a panel and two or more connectors fixed to the panel. The battery assembly is electrically connected to a device outside the enclosed space, such as other battery packs or a high-voltage box, via a connector. The panel is sealed and connected to the shell or the cover, and is connected to the shell via a bracket.

[0003] When assembling the battery pack, the battery assembly is fixed to the shell, the end assembly is installed on the shell via the bracket, the connector on the end assembly is passed through the window of the cover body, and the cover body is covered on the shell. After the two are sealed together by fasteners and sealing rings, the panel of the end assembly is sealed to the cover body, for example, a sealing ring is set between the window and the panel, and a sealing adhesive is applied.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-87913 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned battery pack, the bracket is covered by the cover body, so the cover body becomes larger accordingly, which hinders the miniaturization of the battery pack. In order to miniaturize the battery pack, it is considered to remove the bracket and directly fix the end assembly to the cover body. However, if the cover body is installed on the housing after the end assembly is fixed to the cover body, it becomes difficult to connect the end assembly to the battery assembly. The reason is that the end assembly and the battery assembly are usually connected using metal plates such as bus bars, and additional fastening operations are required to connect them.

[0009] Even if an opening for fastening work is provided in the cover body separately from the window for installing the end assembly, an assembly space is required inside the cover body in order to assemble the end assembly to the cover body in such a manner that the bus bar faces the opening from the end assembly. Furthermore, the end assembly needs to be assembled to the cover body in such a manner that one end of the bus bar can be connected to the battery assembly, etc., and various problems remain in order to enable the fastening work of one end of the bus bar and the battery assembly.

[0010] Means for solving problems

[0011] The battery pack disclosed in the present invention comprises: a battery pack, which is formed by stacking single cells with positive and negative electrode terminals; a lower shell, which is flat and carries the battery pack on its upper surface; an upper shell, which is box-shaped and opens downward and is mounted on the lower shell from above to accommodate the battery pack and the lower shell together inside; and a bus bar module, which is mounted on the upper surface of the battery pack and accommodates a plurality of internal connection bus bars that connect the positive electrode terminal to the negative electrode terminal, the bus bar module comprising: an external connection positive terminal connected to the positive electrode terminal; and an external connection negative terminal connected to the negative electrode terminal, An external connection connector is pre-installed on the side wall of the body, and the external connection connector includes: an external connection positive bus bar, one end of which is fastened to the external connection positive terminal; and an external connection negative bus bar, one end of which is fastened to the external connection negative terminal. An opening is formed on the upper wall of the upper shell to expose one end of the external connection positive bus bar and one end of the external connection negative bus bar to the outside, and the upper shell is installed on the lower shell in a manner that one end of the external connection positive bus bar and the external connection positive terminal are configured to be fastened, and one end of the external connection negative bus bar and the external connection negative terminal are configured to be fastened.

[0012] Effects of the Invention

[0013] According to the present disclosure, it is possible to reduce the size of a battery pack and improve the energy density of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a three-dimensional view of the battery pack viewed from the upper front.

[0015] Figure 2 This is a three-dimensional image of the battery pack viewed from the lower back.

[0016] Figure 3 It is a three-dimensional view of the lower shell.

[0017] Figure 4 It is a perspective view showing a state where a battery pack is placed on the upper surface of the lower case.

[0018] Figure 5 It is a perspective view showing a state where the bus bar module is mounted on the upper surface of the battery pack.

[0019] Figure 6 This is a perspective view showing a state in which an upper housing to which an external connection connector is preliminarily mounted is mounted on a lower housing from above.

[0020] Figure 7 Yes Figure 6A partial enlarged top view of a portion of the image viewed from above.

[0021] Figure 8 It is a three-dimensional view of the upper shell.

[0022] Fig. 9 This is a perspective view of an upper housing with an external connection connector pre-installed, as viewed from obliquely above.

[0023] Fig.10 This is a perspective view of an upper housing with an external connection connector pre-installed, viewed from obliquely below.

[0024] Fig.11 Yes Fig. 9 A partial enlarged top view of a portion of an external connection connector enlarged and viewed from above.

[0025] Fig.12 Yes Fig. 9 A partial enlarged front view of a portion of an external connection connector enlarged and viewed from the front.

[0026] Fig.13 Yes Fig. 9 A partial enlarged rear view of a portion of an external connection connector enlarged and viewed from the rear.

[0027] Fig.14 It is a plan view showing a state where the bus bar module is mounted on the upper surface of the battery pack.

[0028] Fig.15 Yes means Fig.14 A top view of the internal structure of the busbar module.

[0029] Fig.16 is a cross-sectional view showing the internal structure of the battery pack.

[0030] Fig.17 It is a cross-sectional view showing a fastening structure between a second connection portion of the external connection positive electrode bus bar and an external connection positive electrode terminal. DETAILED DESCRIPTION

[0031] [Description of Embodiments of the Present Disclosure]

[0032] First, embodiments of the present disclosure will be described below.

[0033] (1) The battery pack disclosed herein comprises: a battery pack formed by stacking single cells having positive and negative electrode terminals; a lower case in a planar shape on the upper surface of which the battery pack is placed; an upper case in a box shape that opens downward and is mounted on the lower case from above to accommodate the battery pack and the lower case together; and a bus bar module mounted on the upper surface of the battery pack and accommodating a plurality of internal connection bus bars that connect the positive electrode terminal to the negative electrode terminal, the bus bar module comprising: an external connection positive terminal connected to the positive electrode terminal; and an external connection negative terminal connected to the negative electrode terminal, wherein the upper case is in a box shape that opens downward and is mounted on the lower case from above to accommodate the battery pack and the lower case together; An external connection connector is pre-installed on the side wall of the upper shell, and the external connection connector includes: an external connection positive bus bar, one end of which is fastened to the external connection positive terminal; and an external connection negative bus bar, one end of which is fastened to the external connection negative terminal. An opening is formed on the upper wall of the upper shell to expose one end of the external connection positive bus bar and one end of the external connection negative bus bar to the outside, and the upper shell is installed on the lower shell in a manner that one end of the external connection positive bus bar and the external connection positive terminal are configured to be fastened, and one end of the external connection negative bus bar and the external connection negative terminal are configured to be fastened.

[0034] According to the battery pack, the external connection connector is not mounted on the upper case via a bracket, but is directly fixed to the upper case, so the battery pack can be miniaturized and the amount of bracket can be increased, and the energy density of the battery pack can be increased. In addition, the external connection connector is pre-mounted on the upper case, and the upper case is mounted on the lower case in a manner that one end of the external connection positive bus bar is configured to be fastened to the external connection positive terminal, and one end of the external connection negative bus bar is configured to be fastened to the external connection negative terminal, so no assembly space is required inside the upper case, and the battery pack can be further miniaturized.

[0035] (2) Preferably, the busbar module includes a protector for holding the plurality of internal connection busbars, the protector includes a positive terminal insulating wall formed around the external connection positive terminal and a negative terminal insulating wall formed around the external connection negative terminal, and when the upper shell is mounted on the lower shell, one end of the external connection positive busbar is suitably accommodated in the positive terminal insulating wall, and one end of the external connection negative busbar is suitably accommodated in the negative terminal insulating wall.

[0036] When the upper shell is installed on the lower shell, one end of the externally connected positive bus bar is suitably received in the insulating wall of the positive terminal, so that one end of the externally connected positive bus bar and the externally connected positive terminal can be firmly positioned, and one end of the externally connected negative bus bar is suitably received in the insulating wall of the negative terminal, so that one end of the externally connected negative bus bar and the externally connected negative terminal can be firmly positioned.

[0037] (3) Preferably, the bus bar module includes a control substrate and a plurality of voltage detection lines connecting the plurality of internal connection bus bars to the control substrate.

[0038] Since the signals related to the voltage input to the control substrate can be collected through the plurality of voltage detection lines, the collected signals related to the voltage can be output to the outside of the battery pack through one wire.

[0039] (4) Preferably, a gas flow path for discharging gas generated inside the single cell to the outside is formed between the protector and the battery pack.

[0040] Since the gas flow path is formed by attaching the bus bar module to the upper surface of the battery pack, the gas flow path may be formed without being separated from the bus bar module.

[0041] [Details of the embodiments of the present disclosure]

[0042] Hereinafter, specific examples of the connector of the present disclosure will be described with reference to the drawings. In addition, the present disclosure is not limited to these examples, but is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

[0043] <Implementation Method>

[0044] Reference Figures 1 to 17 The embodiments of the present disclosure are described. In the following description, the direction indicated by the arrow X is described as the front-back direction, the direction indicated by the arrow Y is described as the left-right direction, and the direction indicated by the arrow Z is described as the up-down direction. In addition, for a plurality of identical components, sometimes only some of the components are marked with reference numerals, and the reference numerals of the other components are omitted.

[0045] [Battery Pack]

[0046] The battery pack 10 of this embodiment is mounted on a hybrid vehicle that uses an internal combustion engine such as a gasoline engine or a diesel engine and an electric motor that is powered by a rechargeable battery, a plug-in hybrid vehicle that can be externally charged, or an electric vehicle, etc. The battery pack 10 is provided as a driving power source for these vehicles.

[0047] [case]

[0048] like Figure 1 and Figure 2 As shown in FIG. 1 , the battery pack 10 includes a housing 20 composed of a planar lower housing 21 and a box-shaped upper housing 22 opened downward. The housing 20 has a substantially rectangular block shape. Figure 4 The battery pack 30 and Figure 5 The bus bar module 40 is shown.

[0049] like Figure 2 As shown, a safety valve 23 is mounted on the rear surface of the upper case 22. The safety valve 23 is connected to a gas flow path 49A described later and is configured to release gas in the battery pack 30 to the outside of the case 20 when the internal pressure of the battery pack 30 reaches a predetermined pressure.

[0050] like Figure 3 and Figure 4 As shown, the lower case 21 has: an upper surface 21A on which the battery pack 30 is placed; a square tube portion 21B protruding upward from the upper surface 21A; a plurality of mounting holes 21C formed around the square tube portion 21B of the upper surface 21A; and a pair of positioning protrusions 21D.

[0051] like Figure 3 As shown, a pair of positioning protrusions 21D are formed at a pair of corners constituting diagonal corners among the four corners of the lower housing 21. On the other hand, a pair of positioning holes 22D are formed through the upper housing 22 at positions corresponding to the pair of positioning protrusions 21D. By inserting the pair of positioning protrusions 21D into the pair of positioning holes 22D, the lower housing 21 and the upper housing 22 are assembled in a correctly positioned state.

[0052] A square annular seal ring 24 is installed between the square tube portion 21B and each mounting hole 21C on the upper surface 21A of the lower housing 21. Insertion holes 22C (see FIG. 2 ) for inserting mounting bolts B1 are formed at positions corresponding to the mounting holes 21C in the upper housing 22. Figure 6 ).

[0053] The upper case 22 is mounted on the lower case 21 from above, and the mounting bolts B1 are inserted through the insertion holes 22C and tightened in the mounting holes 21C, thereby clamping the sealing ring 24 between the lower case 21 and the upper case 22. Thus, the lower case 21 and the upper case 22 are fixed in a state where the space between the lower case 21 and the upper case 22 is sealed.

[0054] [Battery Pack]

[0055] The battery pack 10 further includes a battery group 30. Figure 4 As shown in FIG. 1 , the battery pack 30 is formed by stacking a plurality of cells 31. The cells 31 are composed of storage batteries (secondary batteries) such as lithium-ion batteries or nickel-metal hydride batteries. The plurality of cells 31 are arranged in the front-to-back direction ( Figure 4 The layers are stacked in the direction indicated by the arrow X in FIG.

[0056] The single cell 31 has a substantially rectangular thin plate shape. The plurality of single cells 31 are stacked in such a manner that the side surfaces having the largest area among the plurality of side surfaces constituting the appearance of the single cell 31 face each other between the adjacent single cells 31 in the stacking direction. The plurality of single cells 31 are stacked in such a manner that the thickness direction of each single cell 31 is parallel to the stacking direction of the single cells 31.

[0057] The battery pack 30 has a rectangular shape. When the battery pack 30 is viewed from above, the direction in which the long sides of the battery pack 30 extend is parallel to the stacking direction of the cells 31, and the left-right direction in which the short sides of the battery pack 30 extend is parallel to the stacking direction of the cells 31. Figure 4 The direction indicated by the arrow Y in FIG. 1 is orthogonal to the stacking direction of the single cells 31.

[0058] The battery pack 30 has an upper surface 32 and a plurality of electrode terminals 33. The upper surface 32 is a plane constituting the upper portion of the battery pack 30. The plurality of electrode terminals 33 protrude from the upper surface 32. The plurality of electrode terminals 33 are arranged in two rows in the stacking direction of the single cells 31.

[0059] More specifically, the single cell 31 has a positive terminal 33P and a negative terminal 33N constituting the electrode terminal 33. In each single cell 31, the positive terminal 33P and the negative terminal 33N are arranged separately in the left-right direction. In the battery pack 30, the positive terminal 33P and the negative terminal 33N are arranged alternately in the stacking direction of the single cells 31. The positive terminal 33P and the negative terminal 33N adjacent to each other in the stacking direction of the single cells 31 are connected by an internal connection bus bar 41 described later. The plurality of single cells 31 are electrically connected in series.

[0060] The cell 31 further includes an open valve 34. The open valve 34 is provided between the positive terminal 33P and the negative terminal 33N on the upper surface 32 of the cell 31. The open valve 34 opens when the pressure of the gas generated inside the cell 31 rises, thereby releasing the pressure inside the cell 31. Each open valve 34 is connected to a gas flow path 49A described later. Thus, the gas generated inside the cell 31 is discharged to the gas flow path 49A, and is discharged from the gas flow path 49A to the outside of the housing 20 via the safety valve 23.

[0061] [Bus bar module]

[0062] The battery pack 10 further includes a bus bar module 40. Figure 5 As shown, the bus bar module 40 is mounted on the upper surface 32 of the battery pack 30. Fig.15As shown, the busbar module 40 has a plurality of internal connection busbars 41 . The plurality of internal connection busbars 41 are arranged in two rows in the front-rear direction indicated by arrow X. The arrangement direction of the plurality of internal connection busbars 41 is parallel to the stacking direction of the cells 31 .

[0063] The internal connecting busbars 41 are connected to the positive electrode terminals 33P and the negative electrode terminals 33N adjacent to each other in the stacking direction of the cells 31. The internal connecting busbars 41 on the left side of the figure and the internal connecting busbars 41 on the right side of the figure are arranged in a staggered pattern in the stacking direction of the cells 31.

[0064] The bus bar module 40 further includes a plurality of voltage detection lines 42. The voltage detection lines 42 are electric wires for detecting the state of the battery pack 30. The voltage detection lines 42 detect the voltage of the battery pack 30. One ends of the plurality of voltage detection lines 42 are connected to the plurality of internal connection bus bars 41, respectively.

[0065] The bus bar module 40 further includes a resin protector 43. The protector 43 includes a box-shaped protector body 43A opened upward and a pair of covers 43B covering the protector body 43A from above. The pair of covers 43B are connected to the left and right sides of the protector body 43A via hinges.

[0066] The protector body 43A holds a plurality of internal connection bus bars 41 and a control substrate 44. Each internal connection bus bar 41 is held at a position that allows connection with each electrode terminal 33. Thus, when the bus bar module 40 is mounted on the upper surface 32 of the battery pack 30, each internal connection bus bar 41 is disposed at a position corresponding to each electrode terminal 33.

[0067] The other ends of the plurality of voltage detection lines 42 are connected to a control substrate 44. A plurality of relays 44A, FRAM 44B, an output connector 44C, etc. are mounted on the control substrate 44. Voltage-related signals input from the voltage detection lines 42 to the control substrate 44 are collected and output from the output connector 44C to an external device through one wire.

[0068] exist Fig.15 In the figure, the electrode terminal 33 located at the uppermost side among the electrode terminals 33 on the left side is a positive terminal 33P, which is a total positive terminal 33P1 not connected to the internal connection bus bar 41. In addition, the electrode terminal 33 located at the lowermost side among the electrode terminals 33 on the right side is a negative terminal 33N, which is a total negative terminal 33N1 not connected to the internal connection bus bar 41.

[0069] An external connection positive terminal 45P and an external connection negative terminal 45N are arranged at the lower end of the protector body 43A as shown in the figure. The external connection positive terminal 45P is arranged on the left side of the external connection negative terminal 45N. The external connection positive terminal 45P is composed of the right end of the positive terminal third relay bus 46P3. The external connection negative terminal 45N is composed of the left end of the negative terminal relay bus 46N. The external connection positive terminal 45P is connected to one end of the external connection positive bus 52 described later, and the external connection negative terminal 45N is connected to one end of the external connection negative bus 53 described later.

[0070] The total positive terminal 33P1 is connected to one end of the external connection positive bus bar 52 via the positive terminal first relay bus bar 46P1, the control substrate 44, the positive terminal second relay bus bar 46P2, the fuse 47, and the positive terminal third relay bus bar 46P3. The total negative terminal 33N is connected to one end of the external connection negative bus bar 53 via the negative terminal relay bus bar 46N.

[0071] A gas flow path forming portion 49 extending in the front-rear direction is provided at the center portion in the left-right direction of the protector body 43A. Fig.16 As shown, a gas flow path 49A for discharging the gas generated inside the single cell 31 to the outside is formed between the gas flow path forming portion 49 and the upper surface 32 of the battery pack 30. The open valve 34 of each single cell 31 is connected to the gas flow path 49A. The gas flow path 49A is in a form extending in the front-rear direction, and the downstream end of the gas flow path 49A is connected to the safety valve 23.

[0072] like Fig.14 As shown, a positive terminal insulating wall 48P and a negative terminal insulating wall 48N are formed on a pair of covers 43B of the protector 43. Each insulating wall 48P, 48N is arranged at the lower end of the pair of covers 43B shown in the figure. The positive terminal insulating wall 48P is formed around the externally connected positive terminal 45P, and the negative terminal insulating wall 48N is formed around the externally connected negative terminal 45N. Each insulating wall 48P, 48N is formed by opening a part of the pair of covers 43B, and is formed in a door shape that opens downward in the figure.

[0073] [External connection connector]

[0074] like Figure 8 and Fig. 9 As shown, a through hole 25 is formed in the side wall 22B of the upper case 22, through which the external connection connector 50 is arranged. In the side wall 22B of the upper case 22, a plurality of insertion holes 25A are formed around the through hole 25. The external connection connector 50 includes a resin case 51, an external connection positive bus bar 52, and an external connection negative bus bar 53.

[0075] like Fig.17 As shown, the housing 51 includes: a cylindrical housing body 51A that passes through the through hole 25 and protrudes to the outside of the upper housing 22; and a flange 51B that extends from the end of the housing body 51A along the inner surface of the upper housing 22. A nut not shown is accommodated in the flange 51B, and a sealing screw S is inserted through the through hole 25A from the outside of the upper housing 22 and fastened to the nut, thereby fixing the external connection connector 50 to the upper housing 22.

[0076] An annular seal ring 54 is sandwiched between the inner surface of the upper case 22 and the flange 51B. The seal ring 54 is arranged around the through hole 25. Therefore, water is prevented from entering the interior of the upper case 22 from the through hole 25, and water is stopped.

[0077] The external connection positive bus bar 52 and the external connection negative bus bar 53 have the same shape, so the following description will be based on the external connection positive bus bar 52. In addition, for the structure of the external connection negative bus bar 53 that is the same as the external connection positive bus bar 52, the reference numeral portion of the reference numeral is changed from 52 to 53.

[0078] The external connection positive electrode bus bar 52 is formed by punching and bending a plate-shaped metal plate. Fig.17 As shown, the external connection positive electrode bus bar 52 includes: a first connection portion 52A housed in the housing body 51A; a relay connection portion 52B extending upward from the end of the first connection portion 52A; and a second connection portion 52C extending from the end of the relay connection portion 52B to the side opposite to the first connection portion 52A. A bend portion is formed between the first connection portion 52A and the relay connection portion 52B, and a bend portion is formed between the relay connection portion 52B and the second connection portion 52C.

[0079] The first connection portion 52A has a locking hole 52A1. On the other hand, the housing body 51A has a lance 51A1 that fits into and locks the locking hole 52A1. The external connection positive bus bar 52 is held by the housing 51 by the lance 51A1 being locked to the inner wall of the locking hole 52A1.

[0080] The housing body 51A has a receiving hole 51A2 for receiving the first connection part 52A. A small gap is set between the first connection part 52A and the inner wall of the receiving hole 51A2. Therefore, when the second connection part 52C is connected to the external connection positive terminal 45P, the dimensional tolerance and assembly tolerance of each part can be absorbed.

[0081] The separation dimension between the intermediate connection portion 52B and the flange 51B is the same as or slightly larger than the plate thickness of the intermediate connection portion 52B. In addition, the separation dimension between the intermediate connection portion 52B and the protector 43 of the bus bar module 40 is set to be smaller than the plate thickness of the intermediate connection portion 52B. As a result, the space for accommodating the intermediate connection portion 52B is a relatively narrow area, and the side wall 22B of the upper case 22 is arranged close to the battery pack 30 and the bus bar module 40, and the battery pack 10 is miniaturized.

[0082] like Fig.10 and Fig.11 As shown, the second connection portion 52C of the externally connected positive bus bar 52 and the second connection portion 53C of the externally connected negative bus bar 53 are both exposed to the outside of the upper housing 22 from the opening 26. The externally connected positive bus bar 52 and the externally connected negative bus bar 53 are both guided by the receiving hole 51A2 of the housing 51 so as to be mainly movable in the front-to-back direction, and the movement in the front-to-back direction is suppressed by the lance 51A1, so that they are maintained at a constant position relative to the housing 51. Therefore, the positions where the second connection portions 52C and 53C are exposed to the outside of the upper housing 22 from the opening 26 are approximately constant.

[0083] When the upper housing 22 is mounted to the lower housing 21 in a state where the external connection connector 50 is pre-installed on the side wall 22B of the upper housing 22, as shown in FIG. Figure 7 As shown, the second connection portion 52C of the external connection positive bus bar 52 is configured to be fastened to the external connection positive terminal 45P, and the second connection portion 53C of the external connection negative bus bar 53 is configured to be fastened to the external connection negative terminal 45N.

[0084] Each second connection portion 52C, 53C is appropriately accommodated in each insulating wall 48P, 48N. Fig.17 As shown in the figure, the bolt holes of the second connection parts 52C and 53C, the bolt holes of the terminals 45P and 45N, and the nuts N arranged on the lower sides of the terminals 45P and 45N are arranged coaxially. Therefore, the connection bolts B2 can be fastened to the nuts N from above the second connection parts 52C and 53C. That is, the second connection parts 52C and 53C can be fastened to the terminals 45P and 45N only by mounting the upper case 22 on the lower case 21.

[0085] The opening 26 is closed by the auxiliary cover 27. A sealing ring 28 is installed around the opening 26. The auxiliary cover 27 has an insertion hole formed at a position corresponding to the mounting hole 26A of the opening 26. The auxiliary cover 27 is fixed to the upper wall 22A of the upper housing 22 by inserting the closing bolt B3 through the insertion hole of the auxiliary cover 27 and fastening it to the mounting hole 26A of the opening 26, so that the opening 26 is closed by the auxiliary cover 27. As a result, the sealing ring 28 is clamped between the upper wall 22A of the upper housing 22 and the auxiliary cover 27, so that water does not penetrate into the interior of the housing 20 from the opening 26.

[0086] [How to assemble the battery pack]

[0087] First, as a preliminary preparation before starting to assemble the battery pack 10, the external connection connector 50 is mounted on the upper case 22 using the connection bolts B2. In addition, the internal connection bus bar 41, the control substrate 44, the relay bus bars 46P1, 46P2, 46P3, 46N, and the fuse 47 are assembled inside the protector 43, and the internal connection bus bars 41 are connected to the control substrate 44 using the voltage detection lines 42, thereby assembling the bus bar module 40.

[0088] After the preliminary preparations are completed, the battery pack 10 is assembled. Figure 4 As shown, the battery pack 30 is accommodated in the square tube portion 21B of the lower case 21 from above, and the battery pack 30 is placed on the upper surface 21A. The battery pack 30 is positioned in the front-back direction and the left-right direction by the square tube portion 21B, and is accommodated in a certain position in the vertical direction by being placed on the upper surface 21A.

[0089] Then, if Figure 5 As shown, the bus bar module 40 is mounted on the upper surface 32 of the battery pack 30. When the pair of covers 43B are opened, each internal connection bus bar 41 is arranged on the corresponding electrode terminal 33, so that the internal connection bus bar 41 is connected to the electrode terminal 33. This connection can be performed by laser welding or by bolt fastening.

[0090] After all the fastening connections are completed, the pair of covers 43B are closed. In this state, only the externally connected positive terminal 45P of the positive terminal third relay busbar 46P3 is exposed to the outside from the positive terminal insulating wall 48P, and only the externally connected negative terminal 45N of the negative terminal relay busbar 46N is exposed to the outside from the negative terminal insulating wall 48N. Fig.11 As shown, it is confirmed that the pair of second connection parts 52C and 53C are located at the opening 26.

[0091] Next, the upper case 22 with the external connection connector 50 pre-installed is mounted on the lower case 21 from above. At this time, the upper case 22 is placed on the upper surface 21A of the lower case 21 in a state of being positioned relative to the lower case 21 by inserting the positioning protrusions 21D into the positioning holes 22D. Figure 7 As shown, the upper case 22 is mounted on the lower case 21 in such a manner that the pair of second connection portions 52C and 53C are accommodated inside the pair of insulating walls 48P and 48N. In this way, the upper case 22 is mounted on the lower case 21 in such a manner that the second connection portion 52C of the externally connected positive bus bar 52 and the externally connected positive terminal 45P are configured to be fastened, and the second connection portion 53C of the externally connected negative bus bar 53 and the externally connected negative terminal 45N are configured to be fastened.

[0092] Next, in Figure 6 In the state shown, the mounting bolt B1 is inserted through the insertion hole 22C of the upper case 22 and fastened to the mounting hole 21C of the lower case 21. Thus, the seal ring 24 is sandwiched between the lower case 21 and the upper case 22, and the space between the lower case 21 and the upper case 22 is sealed.

[0093] After all the fastening operations are completed, the external connection positive electrode bus bar 52 is connected to the external connection positive electrode terminal 45P. Figure 7 As shown, by observing the interior of the upper case 22 from the opening 26, it is confirmed that the second connection portion 52C of the externally connected positive bus bar 52 is properly accommodated in the interior of the positive terminal insulating wall 48P. Similarly, it is confirmed that the second connection portion 53C of the externally connected negative bus bar 53 is properly accommodated in the interior of the negative terminal insulating wall 48N.

[0094] Next, the connecting bolt B2 is inserted through the bolt hole of the second connecting portion 52C of the external connection positive bus bar 52 and the bolt hole of the external connection positive terminal 45P, and is fastened to the nut N, thereby connecting the external connection positive bus bar 52 and the external connection positive terminal 45P to be conductive (see Fig.17 ). Similarly, by inserting the connection bolt B2 through the bolt hole of the second connection portion 53C of the external connection negative electrode bus bar 53 and the bolt hole of the external connection negative electrode terminal 45N and fastening it to the nut N, the external connection negative electrode bus bar 53 and the external connection negative electrode terminal 45N are conductively connected.

[0095] Next, the opening 26 is closed by the auxiliary cover 27. The closing bolts B3 are inserted through the insertion holes of the auxiliary cover 27 and fastened to the mounting holes 26A arranged around the opening 26. As a result, the sealing ring 28 is sandwiched between the auxiliary cover 27 and the upper wall 22A of the upper case 22, and the space between the auxiliary cover 27 and the upper wall 22A of the upper case 22 is sealed. After all the fastening operations are completed, the sealing ring 28 is clamped between the auxiliary cover 27 and the upper wall 22A of the upper case 22. Figure 1The battery pack 10 is shown.

[0096] [Effects of the Embodiments]

[0097] The battery pack 10 disclosed in the present invention comprises: a battery pack 30, which is formed by stacking single cells 31 having positive and negative electrode terminals 33; a lower shell 21, which is in a planar shape, and the battery pack 30 is placed on the upper surface 21A; an upper shell 22, which is in a box shape opening downward, and is installed on the lower shell 21 from above, and the battery pack 30 and the lower shell 21 are accommodated inside together; and a bus bar module 40, which is installed on the upper surface 32 of the battery pack 30, and accommodates a plurality of internal connection bus bars 41 connecting the positive electrode terminal 33 with the negative electrode terminal 33, and the bus bar module 40 has an external connection positive terminal 45P connected to the positive electrode terminal 33 and an external connection negative terminal 45N connected to the negative electrode terminal 33, and an external connection bus bar module 40 is pre-installed on the side wall 22B of the upper shell 22. The external connection connector 50 includes an external connection positive bus bar 52 whose second connection portion 52C is fastened to the external connection positive terminal 45P and an external connection negative bus bar 53 whose second connection portion 53C is fastened to the external connection negative terminal 45N. An opening 26 is formed on the upper wall 22A of the upper shell 22 to expose the second connection portion 52C of the external connection positive bus bar 52 and the second connection portion 53C of the external connection negative bus bar 53 to the outside. The upper shell 22 is installed on the lower shell 21 in a manner that the second connection portion 52C of the external connection positive bus bar 52 and the external connection positive terminal 45P are configured to be fastened, and the second connection portion 53C of the external connection negative bus bar 53 and the external connection negative terminal 45N are configured to be fastened.

[0098] According to the battery pack 10 described above, the external connection connector 50 is not mounted on the upper case 22 via a bracket, but is directly fixed to the upper case 22, so that the amount of the bracket can be reduced in size, and the energy density of the battery pack 10 can be increased. In addition, the external connection connector 50 is pre-mounted on the upper case 22, and the upper case 22 is mounted on the lower case 21 in a manner such that the second connection portion 52C of the external connection positive bus bar 52 and the external connection positive terminal 45P are configured to be fastened, and the second connection portion 53C of the external connection negative bus bar 53 and the external connection negative terminal 45N are configured to be fastened, so that no assembly space is required inside the upper case 22, and the battery pack 10 can be further miniaturized.

[0099] Preferably, the busbar module 40 has a protector 43 for retaining a plurality of internally connected busbars 41, the protector 43 having a positive terminal insulating wall 48P formed around an externally connected positive terminal 45P and a negative terminal insulating wall 48N formed around an externally connected negative terminal 45N, and when the upper shell 22 is installed on the lower shell 21, the second connection portion 52C of the externally connected positive busbar 52 is suitably accommodated in the positive terminal insulating wall 48P, and the second connection portion 53C of the externally connected negative busbar 53 is suitably accommodated in the negative terminal insulating wall 48N.

[0100] When the upper shell 22 is installed on the lower shell 21, the second connection portion 52C of the externally connected positive bus bar 52 is suitably accommodated in the positive terminal insulating wall 48P, thereby the second connection portion 52C of the externally connected positive bus bar 52 is positioned in a manner that can be fastened to the externally connected positive terminal 45P, and the second connection portion 53C of the externally connected negative bus bar 53 is suitably accommodated in the negative terminal insulating wall 48N, thereby the second connection portion 53C of the externally connected negative bus bar 53 is positioned in a manner that can be fastened to the externally connected negative terminal 45N.

[0101] The bus bar module 40 preferably includes a control substrate 44 and a plurality of voltage detection lines 42 that connect the plurality of internal connection bus bars 41 to the control substrate 44 .

[0102] Since the signals related to the voltage input to the control substrate 44 can be collected through the plurality of voltage detection lines 42 , the collected signals related to the voltage can be output to the outside of the battery pack 10 through one wire.

[0103] Preferably, a gas flow path 49A for discharging the gas generated inside the single cell 31 to the outside is formed between the protector 43 and the battery pack 30 .

[0104] Since the gas flow path 49A is formed by attaching the bus bar module 40 to the upper surface 32 of the battery pack 30 , the gas flow path 49A may not be formed separately from the bus bar module 40 .

[0105] <Other Implementation Methods>

[0106] (1) In the above embodiment, the bus bar module 40 is exemplified as including the protector 43 , but a bus bar module not including the protector may also be used.

[0107] (2) In the above embodiment, the voltage detection line 42 is constituted by an electric wire, but the voltage detection line may be constituted by a flexible printed circuit board.

[0108] (3) In the above embodiment, the case where the gas flow path 49A is formed between the protector 43 and the battery pack 30 is exemplified. However, the gas flow path may be formed by a member different from the protector.

[0109] Description of Reference Numerals

[0110] 10: Battery Pack

[0111] 20: Housing 21: Lower housing 21A: Upper surface 21B: Square cylinder 21C: Mounting hole 21D: Positioning protrusion 22: Upper housing 22A: Upper wall 22B: Side wall 22C: Insertion hole 22D: Positioning hole 23: Safety valve 24: Sealing ring 25: Through hole 25A: Insertion hole 26: Opening 26A: Mounting hole 27: Auxiliary cover 28: Sealing ring

[0112] 30: Battery pack 31: Cell 32: Upper surface 33: Electrode terminal 33P: Positive terminal 33P1: Total positive terminal 33N: Negative terminal 33N1: Total negative terminal 34: Open valve

[0113] 40: Busbar module 41: Internal connection busbar 42: Voltage detection line 43: Protector 43A: Protector body 43B: Cover 44: Control board 44A: Relay 44B: FRAM 44C: Output connector 45P: External connection positive terminal 45N: External connection negative terminal 46P1: Positive terminal first relay busbar 46P2: Positive terminal second relay busbar 46P3: Positive terminal third relay busbar 46N: Negative terminal relay busbar 47: Fuse 48P: Positive terminal insulating wall 48N: Negative terminal insulating wall 49: Gas flow path component 49A: Gas flow path

[0114] 50: External connection connector 51: Housing 51A: Housing body 51A1: Lance 51A2: Accommodation hole 51B: Flange 52: External connection positive bus bar 52A: First connection part 52A1: Locking hole 52B: Relay connection part 52C: Second connection part (one end) 53: External connection negative bus bar 53A: First connection part 53B: Relay connection part 53C: Second connection part (one end) 54: Sealing ring

[0115] B1: Mounting bolt B2: Connecting bolt B3: Closing bolt N: Nut S: Sealing thread

Claims

1. A battery pack comprising: A battery pack is formed by stacking single cells having positive and negative electrode terminals; The lower housing is planar and has the battery pack mounted on its upper surface; The upper housing is in the shape of a box opened downward, and is mounted on the lower housing from above to accommodate the battery pack together with the lower housing; and A bus bar module is mounted on the upper surface of the battery pack and contains a plurality of internal connection bus bars for connecting the positive electrode terminal with the negative electrode terminal. The bus bar module includes: an externally connected positive terminal connected to the positive electrode terminal; and an externally connected negative terminal connected to the negative electrode terminal. An external connection connector is pre-installed on the side wall of the upper housing. The external connection connector includes: an external connection positive bus bar, one end of which is fastened to the external connection positive terminal; and an external connection negative bus bar, one end of which is fastened to the external connection negative terminal. An opening is formed on the upper wall of the upper case to expose one end of the externally connected positive electrode bus bar and one end of the externally connected negative electrode bus bar to the outside. The upper case is attached to the lower case in such a manner that one end of the external connection positive bus bar is fastened to the external connection positive terminal, and one end of the external connection negative bus bar is fastened to the external connection negative terminal.

2. The battery pack according to claim 1, wherein: The bus bar module includes a protector for holding the plurality of internal connection bus bars. The protector comprises: a positive terminal insulating wall formed around the externally connected positive terminal; and a negative terminal insulating wall formed around the externally connected negative terminal. When the upper shell is mounted on the lower shell, one end of the externally connected positive bus bar is suitably received in the positive terminal insulating wall, and one end of the externally connected negative bus bar is suitably received in the negative terminal insulating wall.

3. The battery pack according to claim 1 or 2, wherein: The bus bar module includes a control substrate and a plurality of voltage detection lines connecting the plurality of internal connection bus bars to the control substrate.

4. The battery pack according to claim 1 or 2, wherein: A gas flow path for discharging gas generated inside the single cell to the outside is formed between the protector and the battery pack.

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