JP2015103383A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of raising temperature of a battery while preventing expansion of capacity of the battery pack.SOLUTION: A battery pack has: an upper stage side power accumulation part in which at least two power accumulation stacks formed by laminating electric cells in a first direction are arranged in a second direction orthogonal to the first direction; a lower stage side power accumulation part which is installed at a lower part of the upper stage side power accumulation part; a pack case which accommodates the upper stage side power accumulation part and the lower stage side power accumulation part; and a reinforcement frame which is the hollow structured reinforcement frame for reinforcing structure of the pack case, arranged at a corresponding position between the adjacent power accumulation stacks, and extends in the first direction along the power accumulation stacks, in which a heater extending in the first direction is installed at least at one of an inside bottom surface and an outer bottom surface of the reinforcement frame.

Description

  The present invention relates to a battery pack mounted on a vehicle, and more particularly to a temperature control technique for the battery pack.

  A hybrid vehicle and an electric vehicle are equipped with a battery that stores electric power supplied to a vehicle driving motor. As a battery structure, a stack structure in which a plurality of unit cells are stacked in a predetermined direction is known. When the temperature of the unit cell decreases, the internal resistance increases, and the input / output characteristics deteriorate. Therefore, various techniques for raising the temperature of the battery have been proposed.

  Patent Document 1 discloses a plurality of secondary batteries, a housing case that houses these secondary batteries and has a metal spacing portion that is spaced from the secondary battery via a gap, and at least one of the outer surfaces of the spacing portions. The temperature control structure provided with the heater provided in a part is disclosed. By providing the air gap, each secondary battery can be indirectly heated through the air in the air gap, so that the temperature variation of each secondary battery can be reduced.

JP 2008-053149 A JP 2011-108652 A

  However, in the configuration of Patent Document 1, since it is necessary to secure a gap between the secondary battery and the heater, the volume of the battery pack is increased. Therefore, an object of the present invention is to provide a battery pack capable of raising the temperature of the battery while preventing the volume of the battery pack from expanding.

In order to solve the above problems, in the battery pack according to the present invention, at least two power storage stacks in which unit cells are stacked in a first direction are arranged in a second direction orthogonal to the first direction. An upper power storage unit, a lower power storage unit installed below the upper power storage unit,
A pack case that houses the upper power storage unit and the lower power storage unit, and a reinforced frame having a hollow structure that reinforces the structure of the pack case, and is disposed at a corresponding position between the adjacent power storage stacks And a reinforcing frame extending in the first direction along these power storage stacks, and a heater extending in the first direction is installed on at least one of the inner bottom surface and the outer bottom surface of the reinforcing frame. It is characterized by that.

  According to the present invention, it is possible to provide a battery pack that can raise the temperature of the battery while preventing the volume of the battery pack from expanding.

It is sectional drawing of a battery pack. It is a schematic plan view which shows arrangement | positioning of each part of a battery pack. It is sectional drawing of the battery pack corresponding to FIG.

  An embodiment of a battery pack according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a battery pack. FIG. 2 is a schematic plan view showing the arrangement of each part of the battery pack. In these drawings, Rh indicates the right direction (that is, the vehicle width direction) toward the traveling direction of the vehicle, Upr indicates the height direction of the vehicle, and Fr indicates the traveling direction of the vehicle. Show. The battery pack 1 of this embodiment stores electric power supplied to a vehicle driving motor such as a hybrid vehicle or an electric vehicle. The battery pack 1 can be installed, for example, in a luggage room or under a seat of a vehicle.

  The battery pack 1 includes a first storage stack 11, a second storage stack 12, a third storage stack 13, a fourth storage stack 14, an upper case 15, a lower case 16, a reinforcing frame 17, a heater 18, and a first storage stack. A main frame 20 and a third main frame 30 are included.

  The first to third power storage stacks 11 to 13 (corresponding to the upper power storage unit) are disposed on the upper stage side, and the fourth power storage stack 14 (corresponding to the lower power storage unit) is disposed on the lower stage side. That is, the battery pack 1 of the present embodiment has a structure in which the power storage stack is stacked in two upper and lower stages. The first power storage stack 11 is configured by stacking unit cells 11a in the vehicle front-rear direction, and a spacer (not shown) is provided between adjacent unit cells 11a for conducting air as cooling air. ing. These unit cells 11a are connected in series. However, the single battery 11a connected in parallel may be included in part.

  In addition, an intake chamber 11b for supplying air toward the spacer is assembled on one side surface of the first power storage stack 11, and air after battery cooling is mounted on the other side surface of the first power storage stack 11. An exhaust chamber 11c for discharging the gas is assembled. The intake chamber 11b and the exhaust chamber 11c extend along the stacking direction of the unit cells 11a. Since the second to third power storage stacks 12 to 13 have the same structure as the first power storage stack 11, the description thereof will not be repeated. Note that the number of power storage stacks arranged on the upper side is not limited to three, and may be two, or four or more. Further, the number of power storage stacks arranged on the lower side is not limited to one, and may be two or more.

  The unit cell 11a is a so-called square battery, and houses a power generation element inside the case. As the unit cell 11a, a lithium ion secondary battery, a nickel hydride secondary battery, or a capacitor can be used.

  The fourth power storage stack 14 is configured by stacking the unit cells 14a in the vehicle width direction, and a spacer (not shown) is provided between the adjacent unit cells 14a for conducting air as cooling air. ing. The fourth power storage stack 14 has a length that covers the entire area of the second power storage stack 12 and covers a part of the first and third power storage stacks 11 and 13 in the vehicle width direction. doing. Since the 4th electrical storage stack 14 is the same structure as the 1st-3rd electrical storage stacks 11-13 except for the arrangement direction of a unit cell, explanation is not repeated.

  These first to fourth power storage stacks 11 to 14 are accommodated in a pack case including an upper case 15 and a lower case 16. A reinforcing frame 17 extending in the front-rear direction of the vehicle is provided inside the pack case. The reinforced frame 17 is disposed between the power storage stacks adjacent in the vehicle width direction, that is, between the first power storage stack 11 and the second power storage stack 12, and between the second power storage stack 12 and the third power storage stack 13. It is installed at a corresponding position and has a length that covers at least the entire length of the first to third power storage stacks 11 to 13. By providing the reinforcing frame 17 inside the pack case, the structure of the pack case is strengthened.

  The reinforcing frame 17 is formed in a hollow shape and has a rectangular cross-sectional shape. Aluminum having high thermal conductivity can be used for the reinforcing frame 17. A heater 18 is installed on the inner bottom surface 17 a of the reinforcing frame 17. The heater 18 has a length that covers at least all of the stacked unit cells 11a. The heater 18 may be longer than the length of the reinforcing frame 17. That is, the heater 18 may protrude from both ends of the reinforcing frame 17. For example, an electric heater can be used as the heater 18. As described above, in the present embodiment, the heater 18 is arranged inside the existing frame for reinforcing the pack case, which is installed between the adjacent power storage stacks. Since it is not necessary to provide a metal separation portion for securing the size of the pack case, it is possible to suppress an increase in the size of the pack case accompanying the installation of the heater 18.

  Next, the operation of the heater 18 will be described with reference to FIGS. 1 and 2. The heater 18 can be operated when the battery temperature reaches a predetermined temperature that is extremely low. The predetermined temperature can be set to an appropriate value from the viewpoint of improving the input / output characteristics of the battery. When the heater 18 is operated, the reinforcing frame 17 in contact with the heater 18 is heated. Since the heater 18 has a length that covers all the unit cells 11a stacked in the vehicle front-rear direction, the temperature of each unit cell 11a can be increased while suppressing temperature variation.

  Further, since the heater 18 is installed on the inner bottom surface 17a of the reinforced frame 17, for example, heat can be made harder to escape from the reinforced frame 17 than when the heater 18 is installed on the inner upper surface 17b. That is, when the heater 18 is installed on the inner upper surface 17 b of the reinforcing frame 17, the heat of the heater 18 increases the temperature of the power storage stack from the gap formed between the first power storage stack 11 and the second power storage stack 12. It becomes easy to radiate heat without contributing. According to the configuration of the present embodiment, the heat of the heater 18 is easily transferred to the entire reinforcing frame 17 via the inner bottom surface 17a of the reinforcing frame 17, so that the battery can be heated more efficiently. Moreover, since the reinforced frame 17 is made of aluminum having a high thermal conductivity, the temperature of the entire reinforced frame 17 can be increased quickly, and the temperature of the plurality of unit cells 11a can be increased more evenly.

  In the above-described embodiment, the heater 18 is installed on the inner bottom surface 17a of the reinforcing frame 17, but it can also be installed on the outer bottom surface 17c of the reinforcing frame 17, as shown in FIG. Further, the heater 17 can be installed on both the inner bottom surface 17a and the outer bottom surface 17c of the reinforcing frame 17. Even if it is these structures, the effect similar to embodiment mentioned above can be acquired.

  Further, by installing the heater 18 on the inner bottom surface 17a or the outer bottom surface 17c of the reinforcing frame 17, the distance between the fourth power storage stack 14 and the heater 18 disposed on the lower side becomes shorter, so that the fourth power storage It becomes easy to raise the temperature of the stack 14. In addition, since the plurality of heaters 18 are installed directly above the fourth power storage stack 14 at a predetermined interval, it is possible to raise the temperature of the stacked unit cells 14a while suppressing temperature variations.

1: Battery pack 11: 1st electrical storage stack 11a, 14a: Cell 12: 2nd electrical storage stack 13: 3rd electrical storage stack 14: 4th electrical storage stack 17: Reinforcement frame 17a: Internal bottom 17b: Internal top 17c: External bottom surface 18: Heater

Claims (1)

An upper-stage power storage unit in which at least two storage stacks in which unit cells are stacked in a first direction are arranged in a second direction orthogonal to the first direction;
A lower-stage power storage unit installed below the upper-stage power storage unit;
A pack case that houses the upper-stage power storage unit and the lower-stage power storage unit;
A reinforced frame having a hollow structure that reinforces the structure of the pack case, the reinforced frame being disposed at a corresponding position between adjacent power storage stacks and extending in the first direction along these power storage stacks And having
A battery pack, wherein a heater extending in the first direction is installed on at least one of an inner bottom surface and an outer bottom surface of the reinforcing frame.

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