JP6318979B2 - Battery unit - Google Patents

Description

  The present invention relates to a battery unit mounted on a vehicle such as an automobile.

  A technology is known in which a storage battery, a circuit board, and the like are accommodated in a case so as to be integrally packed, thereby forming a battery unit. In addition, in such a battery unit, a technique has been proposed that includes a gas discharge duct for introducing a gas generated due to a failure of the battery and discharging the gas outside the vehicle or the like (for example, Patent Document 1).

JP 2009-277647 A

  However, in the thing of patent document 1, since the gas discharge duct for discharging | emitting gas to the exterior of a battery unit is required, there is a concern that a structure may become complicated, for example, when carrying on a vehicle There is a concern that the vehicle mountability is reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery unit capable of appropriately processing gas generated in a battery and simplifying the configuration. .

  The battery unit of the present invention is assembled to a battery (41) having a discharge valve (53) capable of discharging gas generated inside the battery, and to the battery so as to face the discharge valve. A battery cover (44) that forms a gas recovery space (S) by a recess (76) that opens to the side. In addition, a leakage structure is provided in a portion surrounding the gas recovery space, in which a leakage path is formed for leaking gas inside the space to the outside of the battery cover due to an increase in pressure in the gas recovery space.

  A battery cover is assembled to face the battery discharge valve, and in this state, a gas recovery space is formed by the recess of the battery cover. In addition, a gas leakage structure is provided, and a leakage path is formed in a portion surrounding the gas recovery space to leak the gas inside the space to the outside of the cover due to a pressure increase in the gas recovery space. In such a configuration, when the gas is discharged from the discharge valve, the pressure in the gas recovery space is increased by recovering the gas. And gas is gradually discharged | emitted via a leak path | route by the pressure rise in gas recovery space.

  In this case, since the gas is discharged from the gas recovery space to the outside of the cover gradually through the leakage path, it is possible to suppress the gas concentration from rapidly increasing around the battery unit. Further, gas can be discharged without providing a duct through the gas recovery space. As described above, the gas generated in the battery can be appropriately processed and the configuration can be simplified.

The perspective view which shows the whole structure of a battery unit. The exploded perspective view which decomposes | disassembles and shows the main structures of a battery unit The exploded perspective view which decomposes | disassembles and shows each part which comprises an assembled battery module The exploded perspective view which decomposes | disassembles and shows each part which comprises an assembled battery module Vertical sectional view of the position where the discharge valve is cut in the battery module The figure which shows the formation pattern of a metal conductor in a battery cover Top view of the battery cover

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In the present embodiment, it is assumed that the embodiment is embodied in a power supply system mounted on a vehicle. In this power supply system, various on-vehicle electric loads are supplied by power supply from a power supply unit configured using a lithium ion storage battery. Is to be driven. In the present embodiment, a Li battery unit (hereinafter simply referred to as a battery unit) as a power supply unit will be described in detail.

<Battery unit 10>
A specific configuration of the battery unit 10 will be described. First, the overall configuration of the battery unit 10 will be described with reference to FIGS. 1 and 2. In the following description, for the sake of convenience, the vertical direction of the battery unit 10 is defined with reference to FIG. 1 in which the battery unit 10 is installed on a horizontal plane.

  The battery unit 10 includes an assembled battery module 11 having a plurality of can-type cells, a control board 12 that controls charging / discharging in the assembled battery module 11, and a restraint that restrains the assembled battery module 11 from above. A plate 13 and a housing case 14 for housing the assembled battery module 11 and the like are provided.

<Container case 14>
The housing case 14 has a substantially rectangular parallelepiped shape, and includes a base 15 that is fixed at a place where the battery unit 10 is mounted and a cover 16 that is attached above the base 15. Each of the base 15 and the cover 16 has a substantially bottomed box shape, and is formed of, for example, a metal material such as aluminum or a synthetic resin material. The assembled battery module 11 and the control board 12 are opposed to each other vertically so that the assembled battery module 11 is on the bottom and the control board 12 is on the top, and are fixed to the base 15 with screws or the like. The assembled battery module 11 and the control board 12 are accommodated in the accommodation case 14 by assembling the cover 16 with respect to the base 15 from above.

  By assembling the cover 16 to the base 15, a closed space is formed as an in-case space, and the assembled battery module 11, the control board 12, and the like are accommodated in the space. The base 15 has a bottom portion 31 and a standing wall portion 32 extending from the bottom portion 31. The cover 16 includes a top plate portion 35 and a hanging wall portion 36 extending from the top plate portion 35. The cover 16 is assembled to the base 15 in a state where they are stacked on the inside and outside so that the standing wall portion 32 of the base 15 is inside the case and the hanging wall portion 36 of the cover 16 is outside the case. There is a gap between the standing wall portion 32 and the drooping wall portion 36 as a peripheral wall portion, and ventilation is possible inside and outside the case through the gap. The base 15 and the cover 16 correspond to a first member and a second member, respectively, and the gap between the wall portions 32 and 36 corresponds to a ventilation portion.

<Battery module 11>
A specific configuration of the assembled battery module 11 will be described. 3 and 4 are exploded perspective views showing the respective parts constituting the assembled battery module 11 in an exploded manner.

  As shown in FIG. 3, the assembled battery module 11 is roughly divided into a plurality of (in the present embodiment, five) unit cells 41, a battery case 42 that houses these unit cells 41, and a battery case 42. An insulating member 43 and a battery cover 44 provided to overlap the insulating member 43 are provided on the side opposite to the battery of the insulating member 43.

<Single cell 41>
Each of the five unit cells 41 is a lithium ion storage battery having a thin rectangular parallelepiped shape. As shown in FIG. 3, each cell 41 is provided with a positive electrode terminal 51 and a negative electrode terminal 52 on one side surface thereof. Each of these terminals 51 and 52 is constituted by an electrode terminal slightly protruding from the battery side surface. In each unit cell 41, a discharge valve 53 is provided between the positive terminal 51 and the negative terminal 52.

  The discharge valve 53 is a safety valve that is broken and opened when the internal pressure of the unit cell 41 becomes an abnormal pressure. For example, the discharge valve 53 is configured by closing a hole opened in the end surface of the outer case of the unit cell 41 with a thin metal film. Has been. When the internal pressure of the unit cell 41 becomes an abnormal pressure, the metal film of the discharge valve 53 is broken, so that gas generated inside the battery is released to the outside of the battery. Thereby, cell internal pressure falls and the burst of the cell itself is suppressed.

<Battery case 42>
The battery case 42 is a battery housing member for arranging five unit cells 41 in a predetermined stacked state, and is made of, for example, a synthetic resin material having insulation properties. As shown in FIGS. 3 and 5 (a longitudinal sectional view of the position where the discharge valve 53 is cut in the assembled battery module 11), the battery case 42 includes an outer peripheral plate portion 55 serving as an outer peripheral portion, and unit cells stacked vertically. And a partition plate portion 56 provided between the two. In the battery case 42, a plurality of battery housing spaces partitioned in the vertical direction are formed for each unit cell 41 by the partition plate portion 56. The outer peripheral plate portion 55 includes a lower plate portion 55 a that becomes the lower surface portion of the assembled battery module 11 and faces the bottom portion 31 of the base 15, and an upper plate portion 55 b that becomes the upper surface portion of the assembled battery module 11. In the present embodiment, the five unit cells 41 are arranged separately in a three-tier battery group and a two-tier battery group, and the upper surface portion (upper plate portion 55b) of the outer peripheral plate portion 55. Is formed with a step corresponding to the thickness of one unit cell 41.

  As shown in FIG. 3, each single cell 41 has a pair of maximum surfaces having the maximum area on the outer peripheral surface of the battery. In the battery case 42, each unit cell 41 is configured such that one of the pair of maximum surfaces (the lower side in the figure) is on the lower plate part 55 a side and the other (the upper side in the figure) is on the upper plate part 55 b side. It is accommodated in a stacked manner.

  In a state where each unit cell 41 is accommodated in the battery case 42, a part of the unit cell 41 (a part on the electrode side) protrudes from the battery case 42 and is insulated so as to cover the protruding part of the unit cell 41. The member 43 is assembled.

<Insulating member 43>
As shown in FIGS. 3 and 4, the insulating member 43 is provided with a plurality of (in this embodiment, ten) openings 67 in accordance with the positions of the positive terminal 51 and the negative terminal 52 of each unit cell 41. Yes. By assembling the insulating member 43 to the battery case 42, the terminals 51 and 52 of each unit cell 41 are inserted into the plurality of openings 67, respectively. In this state, a plurality of bus bars 61 to 66 are attached to the insulating member 43 so as to close the openings 67. The bus bars 61 to 66 are electrode connection terminals that are connected to the electrodes of the plurality of single cells 41 arranged in the vertical and horizontal directions and connect the single cells 41 in series. The state where the bus bars 61 to 66 are attached to the insulating member 43 is the state shown in FIG.

  Of the six bus bars 61 to 66, four bus bars 62 to 65 are connection terminals for electrically connecting the cells 41 to each other. Regarding the unit cell 41, the positive electrode terminal 51 of one unit cell 41 and the negative electrode terminal 52 of the other unit cell 41 are electrically connected. Specifically, the positive and negative terminals 51 and 52 are connected to the two unit cells 41 adjacent to each other vertically by the bus bars 62 and 64, and the two unit cells 41 adjacent to the left and right by the bus bars 63 and 65. Both the positive and negative terminals 51 and 52 are connected.

  The bus bar 61 is a connection terminal for connecting a positive terminal of a battery pack in which five unit cells 41 are connected in series to the control board 12, and a bus bar 66 is a negative terminal of the battery pack. This is a connection terminal for connecting to the ground. The bus bar 61 is connected to the positive terminal 51 of the single battery 41 that is one end side of the series battery circuit among the five single batteries 41, and protrudes from the electrode connection portion connected to the positive terminal 51 to the anti-battery side. A terminal portion 61x connected to the control board 12 is provided at the protruding portion. Specifically, the terminal portion 61 x is provided so as to extend upward of the assembled battery module 11. The bus bar 66 is connected to the negative electrode terminal 52 of the unit cell 41 which is the other end side of the series battery circuit, and the ground portion is connected to the protruding portion protruding from the electrode connecting portion connected to the negative electrode terminal 52 to the anti-battery side. A ground terminal portion 66x connected to (for example, a vehicle body) is provided.

  Each of the bus bars 61 to 66 is integrally provided with voltage detection terminals 61a to 66a protruding to the anti-battery side.

  In addition to the electrode openings 67 described above, the insulating member 43 is provided with a plurality of (in this embodiment, five) openings 68 in accordance with the position of the discharge valve 53 of each unit cell 41. Yes. In the insulating member 43, a recess 69 is formed for each of the left and right battery groups on the opposite battery side on the periphery of each opening 68, and packings 71 and 72 are assembled to the recess 69, respectively. The packings 71 and 72 are seal members having a plurality of annular portions. When the packings 71 and 72 are assembled to the insulating member 43, the opening 68 of the insulating member 43 and the opening 73 of the packings 71 and 72 communicate with each other. It has come to be.

  The insulating member 43 is formed of an insulating material, and is formed of, for example, a synthetic resin such as polypropylene (PP resin), PP resin containing filler and talc. The insulating member 43 is preferably formed of a synthetic resin having heat resistance and heat insulation. The packings 71 and 72 are made of a material having heat resistance and elasticity, and may be made of rubber such as ethylene propylene diene rubber (EPDM).

  The assembly of the battery case 42 and the insulating member 43 is performed using a plurality of assembly fittings 75. Specifically, protrusions are respectively formed at the coupling end portions of the battery case 42 and the insulating member 43, and the battery case 42 and the insulating member 43 are sandwiched by the assembly fittings 75. Assembling with is done.

<Battery cover 44>
A specific configuration of the battery cover 44 will be described. 6 is a perspective plan view of the battery cover 44 viewed from the side opposite to the battery with respect to the insulating member 43 side, and FIG. 7 is a plan view of the battery cover 44 viewed from the battery side.

  As shown in FIG. 4, the battery cover 44 covers all the bus bars 61 to 66 attached to the insulating member 43 from the anti-battery side and protects the bus bars 61 to 66. For example, in the assembling process of the battery unit 10, it is possible to suppress the inconvenience that tools, other parts, and the like come into contact with the bus bars 61 to 66 when the assembled battery module 11 is assembled.

  As a structure for assembling the battery cover 44 to the insulating member 43, the insulating member 43 is provided with connecting bars 91 extending to the anti-battery side at a plurality of locations (four locations in the present embodiment). A plurality of insertion portions 92 having insertion holes for inserting 91 are provided. A male screw is formed at the tip of the connecting bar 91, and the nut 93 is screwed onto the male screw at the tip of the bar while the connecting bar 91 is inserted into the insertion hole of the insertion part 92, thereby insulating member. A battery cover 44 is assembled to 43.

  Further, the battery cover 44 has a main body portion 100 made of an insulating synthetic resin, and the main body portion 100 has a terminal of each unit cell 41 with respect to an assembled battery in which five unit cells 41 are connected in series. A voltage output path for outputting a voltage to the control board 12 is provided. Specifically, as shown in FIG. 6, six metal conductors 101 as conductive members are insert-molded (embedded) in the body 100 so as not to contact each other, and voltage is generated by the metal conductors 101. An output path is formed. One end side and the other end side of the metal conductor 101 protrude from the main body 100. In this case, the connection terminal 101 a on one end side of the metal conductor 101 is a bus bar connection terminal connected to the voltage detection terminals 61 a to 66 a of each bus bar 61 to 66, and the connection terminal 101 b on the other end side is connected to the control board 12. A board connection terminal electrically connected to the board.

  Each of the metal conductors 101 is a rectangular conductor having a rectangular cross section and is formed by punching, for example, a copper plate having excellent conductivity, and has a positioning hole 102 for positioning with a jig during insert molding. A plurality of metal conductors 101 are provided. A positioning pin of a jig is inserted into the positioning hole 102, and the metal conductor 101 is insert-molded in the main body 100. Accordingly, as shown in FIG. 7, a through hole 103 is formed by a positioning pin on the battery side resin surface of the battery cover 44 in the insert molding stage, and the positioning hole 102 of the metal conductor 101 communicates with the through hole 103. The battery cover 44 is exposed on the side opposite to the battery.

  The six connection terminals 101a on the bus bar side are arranged at positions corresponding to the bus bars 61 to 66, respectively, and the voltage detection terminals 61a to 66a are inserted into the through holes provided in the respective bus bars 61 to 66, thereby being electrically connected. Has been made.

  Further, the six connection terminals 101 b on the board side are collectively arranged in a terminal holding portion 88 provided at a position directly below the control board 12. Each connection terminal 101b extends vertically upward, and its tip is connected to the control board 12.

  As shown in FIG. 7, the battery cover 44 is formed with recesses 76 at positions on the battery side that match the discharge valves 53 of the five unit cells 41. In this case, the five concave portions 76 are provided corresponding to the three-stage battery group and the two-stage battery group, and open to the battery side respectively (see FIG. 5).

  As shown in FIG. 5, in the state where the battery cover 44 is assembled to the insulating member 43, the peripheral portion of each recess 76 on the battery side end surface of the battery cover 44 faces the peripheral portion of the opening 68 of the insulating member 43. And packings 71 and 72 are attached in a compressed state between them. In this case, by assembling the battery cover 44 to the insulating member 43, the gas recovery space S is formed by the recess 76, and the gas recovery space S is sealed by the packings 71 and 72.

  Note that the gas discharged from the unit cell 41 is generated due to an abnormality inside the unit cell 41 and is at a high temperature, so that the synthetic resin forming the battery cover 44 is not melted by the gas. In addition, for example, polyphenylene sulfide resin (PPS), polybutylene terephthalate resin (PBT), and various resins to which a flame retardant is added may be used.

  When using the battery unit 10 having the above configuration, when gas is generated inside the unit cell 41, the gas is introduced into the gas recovery space S through the discharge valve 53. Thereby, the pressure in the gas recovery space S increases. In this case, a gas leakage path is formed by a pressure increase in the gas recovery space in a portion surrounding the gas recovery space S, and gas in the space is leaked to the outside of the battery cover 44 through the gas leakage path. In the present embodiment, the gas leakage path from the gas recovery space S is formed in a leakage path formed along the outer surfaces of the packings 71 and 72 and a minute gap portion between the main body 100 and the metal conductor 101. It is assumed that the gas is leaked to the outside of the cover through these leakage paths.

  Specifically, the gas recovery space S is sealed by the packings 71 and 72, but when the pressure in the gas recovery space S rises due to gas generation in the unit cell 41, it follows the outer surfaces of the packings 71 and 72. Thus, a leakage path is formed, and gas is leaked through the leakage path. In this case, according to the sealing action of the packings 71 and 72, a minute gap is formed outside the packings 71 and 72, and this serves as a leakage path, and the gas in the gas recovery space S is gradually discharged to the outside. .

  Moreover, in the structure by which the metal conductor 101 was insert-molded in the main-body part 100, although the metal conductor 101 is surrounded by the main-body part 100, it is thought that the micro clearance gap exists in the surface. In this case, since both ends of the metal conductor 101 protrude from the main body 100 as connection terminals 101 a and 101 b and a part of the metal conductor 101 is exposed in the recess 76, a gas recovery space is formed by a minute gap existing along the metal conductor 101. S and the outside of the cover are connected. Therefore, the gas in the gas recovery space S is gradually discharged to the outside by the leakage path formed along the metal conductor 101.

  Further, the gas leaked to the outside from the battery cover 44 is discharged out of the battery unit through a gap portion (ventilation portion) between the base 15 and the cover 16 in the housing case 14. In this case, the gas in the housing case 14 is discharged little by little through the gap portion (ventilation portion) between the base 15 and the cover 16, and even with this, the gas concentration in the peripheral portion of the unit is reduced. The rise is slowed down.

  As mentioned above, according to this embodiment explained in full detail, the following outstanding effects are acquired.

  The battery cover 44 is assembled to face the discharge valve 53 of the unit cell 41, and the gas recovery space S is formed by the recess 76 of the battery cover 44 in that state. In addition, a gas leakage structure is provided, and a leakage path for leaking gas inside the space to the outside of the cover due to a pressure increase in the gas recovery space S is formed in a portion surrounding the gas recovery space S. In this case, since the gas is discharged from the gas recovery space S to the outside of the cover gradually through the leakage path, the gas concentration around the battery unit is prevented from rising all at once. For example, even if the exhaust gas from the unit cell 41 has a strange odor, it is possible to suppress inconveniences such as the user in the vehicle being uncomfortable due to the bad odor. Further, gas can be discharged without providing a duct through the gas recovery space S. As described above, the gas generated in the unit cell 41 can be appropriately processed, and the configuration can be simplified.

  The configuration in which gas is leaked through the seal portions of the packings 71 and 72 surrounding the gas recovery space S and the minute gap around the metal conductor 101 embedded in the battery cover 44 is suitable for simplifying the configuration.

  The compression state of the packings 71 and 72 can be easily adjusted by changing the cross-sectional dimensions of the packings 71 and 72 or by changing the dimensions of the packing accommodating portion (the opposing dimension between the insulating member 43 and the battery cover 44). it can. Therefore, the degree of gas leakage from the gas recovery space S can be easily set.

  Since the gas leaked from the gas recovery space S to the internal space of the housing case 14 is discharged outside the battery unit through the ventilation portion of the housing case 14, the increase in the gas concentration in the peripheral portion of the unit is slowed down. be able to. Also by this, the effect that a bad smell can be eliminated is obtained.

(Other embodiments)
You may change the said embodiment as follows, for example.

  In the above embodiment, the gas leakage path from the gas recovery space S is formed in the leakage path formed along the outer surfaces of the packings 71 and 72 and in the minute gap portion between the main body 100 and the metal conductor 101. However, any one of these leakage paths only needs to exist.

  In the packings 71 and 72, a configuration in which a through hole communicating with the adjacent opening 73 may be provided. According to this configuration, the gas recovered in the gas recovery space S is discharged to the adjacent gas recovery space S through the minute gaps outside the packings 71 and 72 and the through holes. Thereby, when gas is discharged only from a specific discharge valve 53, the gas recovery space S that has not been discharged from the other discharge valves 53 can be used effectively.

  -In the recessed part 76 of the battery cover 44, the structure by which the through-hole which connects the gas recovery space S to the wall part which separates the adjacent gas recovery space S may be provided. According to such a configuration, the gas recovered in the gas recovery space S is discharged to the adjacent gas recovery space S through this through hole.

  -In this embodiment, although the unit cell 41 was made into the lithium ion storage battery, other livestock batteries (for example, nickel metal hydride battery) may be sufficient.

  DESCRIPTION OF SYMBOLS 10 ... Battery unit, 41 ... Single cell (battery), 44 ... Battery cover, 53 ... Discharge valve, 76 ... Recessed part

Claims (6)

A battery (41) having a discharge valve (53) capable of discharging gas generated inside the battery;
A battery cover (44) that is assembled to the battery so as to face the discharge valve and forms a gas recovery space (S) by a recess (76) that opens to the discharge valve side;
A housing case (14) having a first member (15) and a second member (16) and housing the battery and the battery cover;
With
A portion surrounding the gas recovery space is provided with a leakage structure in which a leakage path for leaking gas inside the space to the outside of the battery cover due to an increase in pressure in the gas recovery space is formed ,
The battery unit is configured such that the gas leaked to the outside of the battery cover is discharged to the outside of the battery unit through a gap portion between the first member and the second member . A seal member (71, 72) provided on the battery side end surface of the battery cover, and compressed by assembling the battery cover to the battery to seal the periphery of the gas recovery space;
The battery unit according to claim 1, wherein the leakage path is formed along an outer surface of the seal member due to an increase in pressure in the gas recovery space. The battery cover is assembled to an assembled battery composed of a plurality of the batteries, and a plurality of the recesses are formed in accordance with the position of the discharge valve of each battery,
The battery unit according to claim 2, wherein the seal member individually seals a plurality of gas recovery spaces formed by the plurality of recesses. The battery cover has a main body (100) formed of an insulating material, and a conductive member (101) embedded in the main body,
The conductive member has at least one end protruding from the main body portion, and a part of the conductive member is exposed in the recess,
The battery unit according to any one of claims 1 to 3, wherein the leakage path is formed in a minute gap portion between the main body portion and the conductive member due to an increase in pressure in the gas recovery space. . A circuit board (12) having an electric circuit for controlling charging and discharging of the battery;
The conductive member electrically connects the electrode terminals (51, 52) of the battery and the circuit board,
5. The battery unit according to claim 4, wherein the protruding portion protruding from the main body portion of the conductive member is a connection terminal portion connected to the circuit board and the electrode terminal. Wherein comprising a housing case (14) for housing a battery module (11) comprising a said battery and said battery cover,
The accommodating case has substantially the first member (15) and said second member having a bottomed box shape (16), respectively, so as to face the peripheral wall of each of these members (32, 36) and out of one another Assembling, and forming the space portion for accommodating the battery module by the assembly,
6. The battery unit according to claim 1, wherein the peripheral wall portions of the first member and the second member face each other with a predetermined distance therebetween, and the gap portion serves as a ventilation portion.