JP5609804B2 - Terminal protection structure and vehicle - Google Patents

Description

  The present invention relates to a protective structure for protecting a protruding terminal formed on a single cell.

  An electric vehicle and a hybrid vehicle include a vehicle battery that can be charged and discharged. As this type of vehicle battery, an assembled battery in which a plurality of unit cells capable of obtaining high output is stacked is known. Since the assembled battery receives various external forces in the event of a vehicle collision, the assembled battery includes a protective structure that protects the unit cells from the external force.

  Patent Document 1 discloses a battery pack in which a battery assembly in which a plurality of battery modules are stacked is covered with a battery case including an upper case and a lower case. A protruding terminal electrode is formed on the side surface of the battery assembly (the surface facing the upper case) (see FIG. 1).

JP 2006-236826 A JP 2008-269895 A JP 2001-332232 A

However, the upper case of Patent Document 1 is insufficient as a protective structure for the terminal because the shape of the region facing the terminal extends in the radial direction of the terminal. That is,
When an impact is applied to the upper case from the direction in which the terminal extends, the deformed upper case may come into contact with the terminal and a large load may be applied.

  Therefore, an object of the present invention is to reduce the load applied to the terminal in the event of a collision.

In order to solve the above problems, a terminal protection structure according to the present invention includes (1) a battery group in which a plurality of unit cells each having a protruding terminal are stacked, and a case for housing the battery group; It has, on the outer surface of the case is a protruding direction of the terminals, and the step-shaped portion which projects in a direction away from the battery group is formed, contact the projecting direction of the terminal The step shape portion has a region aligned with the terminal.

  (2) In the configuration of (1), T ≧ 3S is satisfied, where T is the width in the stacking direction of the unit cells of the stepped portion and S is the distance between the terminals adjacent in the stacking direction. It is preferable to do this. According to the configuration of (2), the shock absorbing ability of the step shape portion is increased, and the terminal can be more reliably protected.

(3) In the above configuration (1) or (2), Oite the projecting Direction of the terminals, the step-shaped section, along with more than half of the region including the central portion in the radial direction of the terminal. According to the configuration of (3), the shock absorbing ability of the step shape portion is further increased, and the terminal can be protected more reliably.

(4) In the configurations of (1) to (3), the terminals of the two unit cells adjacent to each other in the stacking direction of the unit cells are connected to each other via a bus bar. A bus bar cover that covers the bus bar is located between the terminal and the stepped portion. According to the configuration of (4), the protection effect of the terminals can be enhanced by the bus bar cover.

  (5) In the configurations of (1) to (4) above, the case may be an upper case that houses the battery group fixed to the lower case.

(6) A vehicle provided with the terminal protection structure according to any one of (1) to (5) above, wherein the battery group is a luggage room formed at the rear of the vehicle relative to the rear seat of the vehicle. Is housed in a state where the stacking direction of the unit cells is directed in the vehicle width direction, and the terminal protrudes toward the rear of the vehicle. According to the configuration of (6), the terminal can be protected when the cargo stored in the luggage room comes into contact with the case from the rear of the vehicle when the vehicle collides.

(7) A vehicle including the terminal protection structure according to (5), wherein the battery group is arranged in a stacking direction of the single cells in a luggage room formed at the rear of the vehicle relative to a rear seat of the vehicle. legs but are housed in a state oriented in a vehicle width direction, the terminal is protruded toward the rear of the vehicle, said lower case are each at both ends in the vehicle width direction, which is fixed to the fixed part of the vehicle A plurality of the step-shaped portions are formed at intervals in the vehicle width direction. The plurality of step-shaped portions include a first step-shaped portion and a vehicle that is closer to the first step-shaped portion than the first step-shaped portion. A second step shape portion formed at a position spaced apart from the center in the width direction, and the first step shape portion has a larger dimension in the vehicle width direction than the second step shape portion. According to the configuration of (7), when the load stored in the luggage room comes into contact with the case at the time of the vehicle collision, the external force is likely to increase, and the rigidity of the step shape portion on the center side in the vehicle width direction increases. Depending on the strength distribution of external force, the terminal can be protected properly

  According to the present invention, it is possible to reduce the load applied to the terminal in the event of a collision.

It is the schematic of the vehicle carrying a battery pack. It is a disassembled perspective view of a battery pack. It is sectional drawing which cut | disconnected the battery pack by the Rr-Up surface. It is the perspective view which looked at the battery pack from the vehicle back. It is the schematic of the vehicle by which the battery pack which concerns on a modification is mounted.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a vehicle equipped with a battery pack according to the present embodiment, and shows only the rear of the vehicle. Here, the arrow Fr indicates the traveling direction of the vehicle (vehicle forward direction), Rr indicates the direction opposite to the traveling direction of the vehicle (vehicle backward direction), and the same applies to other drawings. In FIG. 1, the battery pack is schematically illustrated. The vehicle 200 includes a rear seat 201, a luggage room 202, and a battery pack 100. The vehicle 200 is a hybrid vehicle that uses both the first drive unit that drives the motor using the electric power of the battery pack 100 and the second drive unit that is an internal combustion engine as a power source, or only the first drive unit. It may be an electric vehicle provided with as a power source.

  The luggage room 202 is formed in the Rr direction of the rear seat 201. The luggage room 202 can be opened and closed by a back door 204. The luggage room 202 includes a deck panel 202A. A cross member 205 extending in the vehicle width direction is installed on the deck panel 202A.

  The battery pack 100 is placed on the cross member 205 and fixed to the deck panel 202A. A method for fixing the battery pack 100 will be described later. Here, in order to enlarge the luggage room 202, it is necessary to arrange the battery pack 100 in a region closer to the rear seat 201.

  However, when an impact is applied from the rear of the vehicle to the battery pack 100 disposed in a region close to the rear seat 201, the battery pack 100 may move in the Fr direction and come into contact with the rear seat 201. Therefore, it is necessary to firmly fix the battery pack 100 so that the amount of movement of the battery pack 100 in the Fr direction at the time of impact becomes small. However, when the battery pack 100 is firmly fixed, a load applied to the battery pack 100 at the time of impact increases.

  When a vehicle or the like collides from the rear of the vehicle, a part of the collision energy is absorbed by the deformation of the vehicle body. However, since the load or the like located in the luggage room 202 moves in the Fr direction by the inertial force at the time of collision and directly collides with the battery pack 100, the load applied to the battery pack 100 increases. Therefore, in the present embodiment, as described below, the terminals are protected by making a part of the battery pack 100 resistant to impact.

  FIG. 2 is an exploded perspective view of the battery pack 100. RH indicates the direction on the right side in the Fr direction of the vehicle, and LH indicates the direction on the left side in the Fr direction of the vehicle. In addition, when it is not necessary to particularly distinguish the RH direction and the LH direction, they are described as a vehicle width direction. FIG. 3 is a cross-sectional view of the battery pack taken along the Rr-Up plane, with some elements omitted. With reference to these drawings, the battery pack 100 includes a battery group 1 and a pack case 3 that covers the battery group 1. The battery group 1 includes a plurality of single cells 11. These single cells 11 are stacked in the vehicle width direction via spacers 16.

  The unit cell 11 may be a nickel metal hydride battery. Further, the single battery 11 may be a battery module in which a plurality of power generation elements are connected, or a battery element including a single power generation element. The unit cell 11 includes a battery case 11A that houses a power generation element. The battery case 11A may be a resin. The unit cell 11 includes a positive electrode terminal 14 and a negative electrode terminal 15. The positive electrode terminal 14 is formed in a protruding shape on the end face in the Rr direction or the end face in the Fr direction of the unit cell 11. The negative electrode terminal 15 is formed in a protruding shape on the end surface in the Fr direction or the end surface in the Rr direction of the unit cell 11. Screw grooves are formed on the outer peripheral surfaces of the positive terminal 14 and the negative terminal 15. In the unit cells 11 adjacent to each other in the stacking direction, the positive electrode terminal 14 and the negative electrode terminal 15 are adjacent to each other.

End plates 12 are respectively provided at both ends of the battery group 1 in the stacking direction. Arm portions 12A are formed on the upper end surfaces of these end plates 12, and the end portions of the restraining members 13 formed in a columnar shape are fixed to these leg portions 12A. The restraining member 13 extends in the vehicle width direction and restrains the battery group 1. Thereby, the position shift of each cell 11 can be suppressed.
The unit cells 11 adjacent in the stacking direction are connected in series via the bus bar 22. The bus bar 22 includes a pair of insertion openings through which the positive electrode terminal 14 and the negative electrode terminal 15 adjacent in the stacking direction are inserted. When the bus bar 22 is attached, the positive terminal 14 and the negative terminal 15 protrude from the bus bar 22. These bus bars 22 are unitized by a bus bar module 21. As a result, a plurality of bus bars 22 can be simultaneously connected to the positive terminal 14 and the negative terminal 15, and the work burden can be reduced.

  A nut 23 is fastened to the positive terminal 14 and the negative terminal 15. Accordingly, the bus bar module 21 can be fixed in a state where the bus bar 22 is in contact with the positive electrode terminal 14 and the negative electrode terminal 15. However, the bus bar module 21 may be omitted and the bus bars may be individually fastened to the positive terminal 14 and the negative terminal 15.

  The bus bar cover 24 covers the bus bar module 21 that holds the bus bar 22. The bus bar cover 24 may be a resin. The bus bar cover 24 is located between the upper case 31 and the positive terminal 14 (negative terminal 15) in the Rr direction.

  A gap S1 is formed in the Rr direction between the bus bar cover 24 and the positive electrode terminal 14 (negative electrode terminal 15). When the pack case 3 is plastically deformed in the Fr direction due to a load collided from the rear of the vehicle, and the wall portion of the pack case 3 plastically deformed contacts the bus bar cover 24, the bus bar cover 24 is crushed. Part of the impact energy is absorbed.

  The pack case 3 includes an upper case 31 and a lower case 32. A pair of case legs 321 is formed at the end of the lower case 32 in the Rr direction. One case leg 321 is formed on the end side in the RH direction of the lower case 32, and the other case leg 321 is formed on the end side in the LH direction of the lower case 32. These case leg portions 321 are bent toward the lower side of the vehicle, and a hole portion 321A for fixing the lower case 32 to a fixing portion of the vehicle is formed at the tip thereof.

  The fixed portion of the vehicle may be the deck panel 202A. The lower case 32 can be fixed to the deck panel 202A by fastening a fastening member (not shown) to the hole 321A. A notch 321B is formed at the end of the hole 321A in the Rr direction. When an impact is applied to the battery pack 100 from the rear of the vehicle, the notch 321B is plastically deformed, so that the entire battery pack 100 moves in the Fr direction, and the impact is alleviated.

  The upper case 31 includes a case upper surface portion 313, a rear side case side surface portion 311, a front side case side surface portion 312, and a fixed piece portion 314. Here, the rear case side surface portion 311 is a side surface portion viewed from the rear of the vehicle when the back door 204 is opened, and the front side case side surface portion 312 is a side surface facing the rear seat 201. It is a part. A fastening hole portion 314A is formed in the fixed piece portion 314, and the pin portion 323 of the lower case 32 is inserted into the fastening hole portion 314A. A screw groove is formed on the outer peripheral surface of the pin portion 323, and the upper case 31 and the lower case 32 are integrated by fastening a nut (not shown) to the screw groove.

  Referring to FIG. 3, the outer surface of rear side case side surface portion 311 (the surface facing back door 204) is in the protruding direction of positive electrode terminal 14 (negative electrode terminal 15) and from battery group 1. A step-shaped portion 51 that protrudes in the separating direction, that is, the Rr direction of the vehicle is formed. The step-shaped portion 51 has a region that overlaps with the positive electrode terminal 14 (negative electrode terminal 15) when viewed in the protruding direction of the positive electrode terminal 14 (negative electrode terminal 15).

  Thus, when a load or the like in the luggage room 202 collides with the upper case 31 at the time of a vehicle collision, the impact force is absorbed in the step-shaped portion 51, so that the plastically deformed upper case 31 or the like is 15) can be suppressed. Further, even when the plastically deformed upper case 31 or the like is in contact with the positive electrode terminal 14 (negative electrode terminal 15), the impact force is sufficiently absorbed by the step-shaped portion 51, and thus the positive electrode terminal 14 (negative electrode terminal 15). ) Can be reduced.

  Further, since the outer surface of the rear case side surface portion 311 has a concavo-convex structure by the step shape portion 51, it is possible to suppress the generation of abnormal noise during the vibration of the battery pack 100. That is, the step-shaped portion 51 can be used both as a terminal protection function and a noise suppression function.

  Here, the step-shaped portion 51 preferably covers more than half of the region including the central portion in the radial direction of the positive electrode terminal 14 (negative electrode terminal 15) in the protruding direction of the positive electrode terminal 14 (negative electrode terminal 15). . Thereby, since the area | region more than half of each positive electrode terminal 14 (negative electrode terminal 15) overlaps with the level | step difference shape part 51 in Rr direction view, the positive electrode terminal 14 (negative electrode terminal 15) can be protected more reliably. More preferably, the step-shaped portion 51 covers the entire region in the radial direction of the positive electrode terminal 14 (negative electrode terminal 15) in the protruding direction of the positive electrode terminal 14 (negative electrode terminal 15). Thereby, the protective effect of the positive electrode terminal 14 (negative electrode terminal 15) can further be improved.

  Here, as a method of protecting the positive electrode terminal 14 (negative electrode terminal 15), a method of arranging an impact absorbing member such as hard urethane on the outer surface of the upper case 31 (hereinafter referred to as a comparative example) is also conceivable. However, in this method, since the size of the battery pack increases in the Rr direction by the size of the shock absorbing member, the luggage room may be narrowed. On the other hand, in this embodiment, since the positive electrode terminal 14 (negative electrode terminal 15) is protected by forming a part of upper case 31 in a step shape, it is possible to suppress the luggage room 202 from being narrowed. Further, the step-shaped portion 51 can be formed at the same time when the upper case 31 is press-formed. Therefore, the manufacturing process is simplified and the cost can be reduced as compared with the comparative example in which the impact absorbing member needs to be attached.

  Next, the structure of the step-shaped portion 51 will be described in more detail with reference to FIG. FIG. 4 is a perspective view of the battery pack as viewed from the rear of the vehicle, and illustrates the positive electrode terminal (negative electrode terminal) as seen through. However, in order to simplify the drawing, the positive electrode terminal 14 (negative electrode terminal 15) located on the end side in the stacking direction of the battery group 1 is omitted and illustrated.

  Referring to the figure, a plurality of step shape portions 51 are formed at predetermined intervals in the vehicle width direction. Of these step shape portions 51, the first step shape portion 51A formed at a position including the center in the vehicle width direction is the second step shape located outside the first step shape portion 51A in the vehicle width direction. The dimension in the vehicle width direction is set larger than that of the portion 51B.

  As described above, the battery pack 100 is fixed by fastening the case legs 321 formed at both ends in the Rr direction of the lower case 32 to the deck panel 202A. When the battery pack 100 collides with the battery pack 100, the moment acting on the center side in the vehicle width direction of the battery pack 100 becomes relatively large. According to the above-described configuration, the first step shape portion 51A is set to have a larger dimension in the vehicle width direction than the second step shape portion 51B, and is more robust against a collision from the vehicle rear side. It has become. Thereby, the positive terminal 14 (negative terminal 15) located in the more center side of the vehicle width direction can be effectively protected from a collision.

  Further, it is preferable that the condition T ≧ 3S is satisfied, where T is the dimension in the vehicle width direction of the stepped portion 51 and S is the distance between the positive electrode terminal 14 and the negative electrode terminal 15 adjacent in the vehicle width direction. As a result, the shock absorbing power of the stepped portion 51 is increased, so that the positive electrode terminal 14 (negative electrode terminal 15) can be more reliably protected. That is, when the dimension of the step shape portion 51 in the vehicle width direction is, for example, only the distance S, the load at the time of collision concentrates on the small step shape portion 51. On the other hand, by forming the shape of the step-shaped portion 51 so as to satisfy the conditional expression, the rigidity of the step-shaped portion 51 (the rigidity in the Rr direction) can be increased.

  Here, the interval S between the positive electrode terminal 14 and the negative electrode terminal 15 is the total size of the unit cell 11 and the spacer 16 in the vehicle width direction in the configuration in which the spacer 16 is interposed between the adjacent unit cells 11, and the spacer 16 is omitted. In the configuration, the size of the unit cell 11 is in the vehicle width direction.

  In the present embodiment, the dimension in the vehicle width direction of the first step shape portion 51A is 5S, but may be other sizes of 3S or more. Further, although the dimension in the vehicle width direction of the second step shape portion 51B is 2S, it may be other sizes of 3S or more. That is, in this embodiment, in consideration of the particularly large impact force applied to the center side in the vehicle width direction of the battery pack 100, the size in the vehicle width direction of the first step shape portion 51A is set large. In order to increase the rigidity of the pack 100 as a whole, all the step-shaped portions 51 can be configured to satisfy the conditional expression.

  Next, the behavior of the battery pack 100 at the time of a vehicle collision will be described. With reference to FIG. 1, when the vehicle collides with an obstacle, the load mounted in the luggage room 202 moves in the Fr direction by the inertial force and collides with the upper case 31. When the upper case 31 is further pushed in the Fr direction by the impacted load, the upper case 31 is plastically deformed, and a part of the energy at the time of the collision is absorbed. Here, since the step-shaped portion 51 has a structure that is stronger against external force in the Fr direction than the other parts of the upper case 31, more energy is absorbed when the step-shaped portion 51 is plastically deformed. Is done. Thereby, it can suppress that the upper case 31 plastically deformed contact | abuts to the positive electrode terminal 14 (negative electrode terminal 15).

  Even when the energy at the time of collision is large, a large amount of energy is absorbed when the step shape portion 51 is plastically deformed, and further, when the step shape portion 51 plastically deformed contacts the bus bar cover 24, the bus bar cover 24. Most of the remaining energy is absorbed by damage. Therefore, the load when the plastically deformed upper case 31 contacts the positive electrode terminal 14 (negative electrode terminal 15) can be greatly reduced.

(Modification 1)
In the above-described embodiment, the step-shaped portion 51 is provided at a position facing all the positive electrode terminals 14 (negative electrode terminals 15) located on the rear side, but the present invention is not limited to this, and some of the positive electrodes The step-shaped portion 51 may be provided at a position facing the terminal 14 (negative electrode terminal 15). The step-shaped portion 51 facing the part of the positive terminals 14 (negative terminals 15) has a configuration in which a load distribution at the time of collision applied to the battery pack 100 is specified by experiment or simulation, and is provided in a region where the load is particularly large. May be.

(Modification 2)
The first step shape portion 51A may have a longer dimension in the Rr direction than the second step shape portion 51B. Thereby, since the energy absorbed in the first step shape portion 51A at the time of a load collision is increased, the load applied to the positive electrode terminal 14 (negative electrode terminal 15) can be more effectively reduced. Further, as described in the first modification, the load distribution at the time of the collision applied to the battery pack 100 is specified by experiment or simulation, and the Rr direction dimension of the step shape portion formed in the region where the load is particularly large is relatively determined. The structure which enlarges automatically may be sufficient.

(Modification 3)
In the above-described embodiment, the battery pack 100 is disposed in the luggage room 202. However, the present invention is not limited to this, and the battery pack 100 can be mounted at other in-vehicle positions. FIG. 5 is a cross-sectional view of the vehicle according to this modification, and corresponds to FIG. With reference to the figure, the vehicle-mounted position may be a spare tire storage unit 210 provided in the lower portion of the luggage room 202. Also in the configuration of this modification, the positive electrode terminal 14 (negative electrode terminal 15) can be protected from the impact force applied from the rear of the vehicle.

DESCRIPTION OF SYMBOLS 1 Battery group 3 Pack case 11 Single cell 12 End plate 13 Restraining member 14 Positive electrode terminal 15 Negative electrode terminal 16 Spacer 21 Bus bar module 22 Bus bar 24 Bus bar case 31 Upper case 32 Lower case 201 Rear sheet
202 Luggage room 202A Deck panel 204 Back door 205 Cross member 311 Rear side case side
312 Front side case side part 313 Case upper surface part 314 Fixed piece part 321 Case leg part 321A Hole part 321B Notch part

Claims (7)

A battery group in which a plurality of single cells each having a protruding terminal are stacked;
A case for housing the battery group ,
On the outer surface of the case, there is formed a step-shaped portion that protrudes in the protruding direction of the terminal and away from the battery group,
Oite the projecting Direction of the terminals, the step-shaped section, the protective structure of the terminal, characterized in that it has an area aligned with said terminals. The following conditional expression (1) is satisfied, where T is a width in the stacking direction of the unit cells of the stepped portion and S is an interval between the terminals adjacent to each other in the stacking direction. Item 2. A protective structure for a terminal according to Item 1.
T ≧ 3S (1) Oite the projecting Direction of the terminals, the step-shaped section, the protective structure of the terminal according to claim 1 or 2, characterized in that, along with more than half of the region including the central portion in the radial direction of the terminal.
The terminals of the two unit cells adjacent to each other in the stacking direction of the unit cells are connected to each other via a bus bar,
4. The terminal according to claim 1, wherein a bus bar cover that covers the bus bar is located between the terminal and the stepped portion in the protruding direction of the terminal. 5. Protective structure.   5. The terminal protection structure according to claim 1, wherein the case is an upper case that accommodates the battery group fixed to the lower case. 6. A vehicle comprising the terminal protection structure according to any one of claims 1 to 5,
The battery group is housed in a luggage room formed at the rear of the vehicle with respect to the rear seat of the vehicle with the unit cell stacking direction facing the vehicle width direction, and the terminals face the rear of the vehicle. A vehicle characterized by protruding. A vehicle comprising the terminal protection structure according to claim 5,
The battery group is housed in a luggage room formed at the rear of the vehicle with respect to the rear seat of the vehicle in a state where the stacking direction of the single cells faces the vehicle width direction,
The terminal protrudes toward the rear of the vehicle,
The lower case are each at both ends in the vehicle width direction, includes a leg portion which is fixed to the fixed part of the vehicle,
The plurality of step shape portions are formed at intervals in the vehicle width direction, and the plurality of step shape portions are a first step shape portion and a center in the vehicle width direction than the first step shape portion. A vehicle having a second step shape portion formed at a spaced position, wherein the first step shape portion has a dimension in the vehicle width direction larger than that of the second step shape portion. .

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