JP2016122543A - Battery cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variations in temperature of battery cells in a battery module in which a plurality of battery cells are stacked. A battery module (20) includes a plurality of stacked battery cells (22). The lower case 40 and the upper case 60 constitute a housing case, and the battery module 20 is arranged inside the housing case. On the inner surface of the lower case 40, a plurality of protrusions 46 and recesses 48 are provided on the upstream side of the flow of the cooling air, and a plurality of protrusions 50 and recesses 52 are provided on the downstream side. The plurality of protrusions 50 and the recesses 52 are arranged more densely than the plurality of protrusions 46 and the recesses 48. In the width direction orthogonal to the stacking direction, the protrusions 46 and 50 are arranged at the center of the inner surface, and the recesses 48 and 52 are provided at both ends of the inner surface. [Selection diagram] Figure 1

Description

  The present invention relates to a battery cooling device that cools battery cells.

  A hybrid vehicle, an electric vehicle, or the like is equipped with a power storage device that stores electric power supplied to a vehicle driving motor. As this type of power storage device, a battery pack is known that includes a battery module in which a plurality of battery cells are stacked and a housing case that houses the battery module. Generally, an air flow path for introducing cooling air is formed inside the housing case.

  Patent Document 1 discloses a cooling structure for cooling a battery module in which a plurality of battery cells are stacked. In this cooling structure, spacers are arranged between the plurality of battery cells. A passage through which a cooling medium flows is formed on the surface of the spacer. On the surface of the spacer, on the upstream side of the flow of the cooling medium, there are provided a plurality of ribs extending linearly at intervals. A plurality of dot-like bosses are provided on the downstream side.

Japanese Patent Laid-Open No. 2007-200778

  By the way, there may be a portion where the cooling air easily flows and a portion where the cooling air hardly flows inside the housing case. In this case, a difference occurs in the cooling efficiency between those portions, and the temperature of the battery cell varies. For example, in the cooling structure described in Patent Document 1, a plurality of linearly extending ribs are provided on the upstream side, and the air flow path per unit area is more upstream than the downstream side. The area of becomes smaller. Therefore, there may be a problem that the resistance of the flow of cooling air increases on the upstream side and the cooling efficiency on the upstream side decreases. In order to cope with this problem, it is conceivable to increase the width of the opening of the blower or the duct for blowing cooling air into the housing case. However, there arises a problem that the cooling mechanism is increased in size. Although it is desirable that the cooling mechanism be as small as possible, in this respect, the above countermeasures are not suitable.

  The objective of this invention is suppressing the dispersion | variation in the temperature of a battery cell in the battery module in which the some battery cell was laminated | stacked.

  The present invention provides a battery cooling device that cools a battery module in which a plurality of battery cells are stacked, a storage case in which the battery module is stored and cooling air is introduced therein, and at least an inner surface of the storage case A plurality of convex portions provided in part on the cooling air flow path, and a plurality of concave portions provided on the cooling air flow path in at least a part of the inner surface of the housing case, The plurality of convex portions and the plurality of concave portions are provided more densely on the downstream side than the upstream side of the flow of cooling air introduced into the housing case, and are orthogonal to the stacking direction of the plurality of battery cells. The plurality of convex portions are provided at a central portion of the inner surface of the storage case, and the plurality of concave portions are provided at an end portion of the inner surface of the storage case. A pond cooling system.

  According to the present invention, in a battery module in which a plurality of battery cells are stacked, it is possible to suppress variations in temperature of the battery cells.

It is a disassembled perspective view which shows an example of the battery pack which concerns on embodiment of this invention. It is sectional drawing which looked at the battery pack from the side. It is a top view of a lower case. It is IV-IV sectional drawing of FIG. It is VV sectional drawing of FIG.

  FIG. 1 shows an example of a battery pack according to an embodiment of the present invention. The battery pack 10 is used, for example, as a power storage device that stores electric power supplied to a vehicle travel motor.

  The battery module 20 includes a plurality of battery cells 22 stacked in the stacking direction (W direction). The plurality of battery cells 22 are electrically connected to each other by a bus bar (not shown). The battery cell 22 is a rechargeable secondary battery, for example, and is a lithium ion battery as an example. A spacer 24 is disposed between two battery cells 22 adjacent in the stacking direction. The spacer 24 is made of, for example, a resin material. The spacer 24 is formed with an air flow path through which cooling air passes. Thereby, cooling air enters between two battery cells 22 adjacent to each other. Note that a gap may be formed between the two adjacent battery cells 22 instead of the spacer 24. In this case, cooling air enters the gap. End plates 26 and 28 are disposed at both ends of the set of the plurality of stacked battery cells 22. The end plates 26 and 28 are coupled to each other by a restraining band 30 with a plurality of battery cells 22 sandwiched therebetween. Thereby, the some battery cell 22 is hold | maintained integrally.

  The lower case 40 and the upper case 60 constitute a storage case for storing the battery module 20. The battery module 20 is disposed on the lower case 40. The lower case 40 is formed with a channel 42 for a lower air flow path extending in the stacking direction (W direction). A plurality of mounting holes 54 for fixing the battery module 20 with bolts (not shown) are formed on both sides of the channel 42 (both ends in the width direction L). The battery module 20 is disposed on the lower case 40 across the channel 42 and is fixed by the above-described bolts from the lower side of the lower case 40. Thereby, a lower air flow path through which cooling air passes is formed between the battery module 20 and the lower case 40. The lower case 40 is formed with an attachment hole 44 for attaching the upper case 60 to the lower case 40. A screw groove is formed in the attachment hole 44.

  The upper case 60 is formed with an upper air flow channel 62 extending in the stacking direction of the battery cells 22. An attachment hole 64 corresponding to the attachment hole 44 of the lower case 40 is formed in the upper case 60. The upper case 60 is fixed to the lower case 40 by passing the bolts through the mounting holes 44 and 64. An upper air flow path through which cooling air passes is formed between the battery module 20 and the upper case 60. The shapes of the lower case 40 and the upper case 60 are not limited to the shapes shown in FIG. For example, the lower case 40 may have a box shape, and the upper case 60 may have a lid shape.

  On the surface of the channel 42, a plurality of convex portions 46, 50 and concave portions 48, 52 are provided separately in a sparse region 42a and a dense region 42b. Details of the convex portions 46 and 50 and the concave portions 48 and 52 will be described later.

  FIG. 2 shows the internal space of the battery pack 10 as viewed from the side surface (L direction) of the battery pack 10. In FIG. 2, the convex portions 46 and 50 and the concave portions 48 and 52 are not shown. A lower air flow path 56 is formed by the channel 42 between the battery module 20 and the lower case 40. An upper air flow channel 66 is formed by a channel 62 between the battery module 20 and the upper case 60. A cooling blower 70 that supplies cooling air to the inside of the housing case is connected to the battery pack 10. The cooling blower 70 sends cooling air to the inside of the housing case via the intake duct 72. In the example shown in FIG. 2, an intake duct 72 is connected to one end portion (left end portion in the W direction) of the lower air flow path 56, and cooling air is sent from the portion to the inside of the housing case. Reference numeral 100 indicates the flow of cooling air. A part of the cooling air sent to the lower air flow path 56 is sent to the upper air flow path 66 through an air flow path or a gap formed in the spacer 24. The cooling air is sent from the upstream side (left side in the W direction) to the downstream side (right side in the W direction) in the lower air channel 56 and the upper air channel 66. An exhaust duct is provided on the downstream side of the housing case. For example, an exhaust duct is provided at the downstream end of the upper air flow channel 66, and cooling air is discharged from the exhaust duct to the outside of the battery pack 10. Thus, the battery module 20 is cooled.

  Next, the convex portions 46 and 50 and the concave portions 48 and 52 will be described with reference to FIG. FIG. 3 is a top view of the lower case 40. FIG. 3 shows the surface of the channel 42 (the inner surface of the lower case 40). The sparse region 42 a is a region on the upstream side of the lower air flow path 56. The dense area 42 b is an area on the downstream side of the lower air flow path 56. A plurality of convex portions 46 and a plurality of concave portions 48 are provided in the sparse region 42a. A plurality of convex portions 50 and a plurality of concave portions 52 are provided in the dense region 42b. In FIG. 3, the hatched portions indicate the convex portions 46 and 50.

  In the width direction (L direction) orthogonal to the stacking direction (W direction) of the battery cells 22, the plurality of convex portions 46 and 50 are provided at the center of the channel 42, while the plurality of concave portions 48 and 52 are provided in the channel. 42 at both ends.

  The convex portions 46 and 50 have, for example, a cylindrical shape with a rounded upper portion, and project from the surface of the channel 42 in the height direction (H direction). The recesses 48 and 52 have, for example, a cylindrical shape with a round bottom.

  The plurality of convex portions 46 and the plurality of concave portions 48 of the sparse region 42a are arranged at equal intervals, and the plurality of convex portions 50 and the plurality of concave portions 52 of the dense region 42b are spaced apart from the sparse region 42a. Thus, they are arranged at equal intervals. In the example shown in FIG. 3, the convex portions 46 and 50 and the concave portions 48 and 52 are arranged in a staggered manner. As another example, the convex portions 46 and 50 and the concave portions 48 and 52 may be arranged in a lattice shape.

  In both the sparse region 42a and the dense region 42b, an air flow path is formed between the plurality of adjacent convex portions 46 and between the plurality of convex portions 50.

  The plurality of convex portions 50 and the plurality of concave portions 52 provided in the dense region 42b are arranged more densely than the plurality of convex portions 46 and the plurality of concave portions 48 provided in the sparse region 42a. That is, the number of the plurality of convex portions 50 and the plurality of concave portions 52 arranged per unit area in the dense region 42b is larger than that in the sparse region 42a. Thereby, the area of the air flow path formed per unit area in the sparse region 42a becomes larger than the area of the air flow path formed per unit area in the dense region 42b.

  In the example illustrated in FIG. 3, as an example, the convex portion 46 and the concave portion 48 of the sparse region 42 a have the same diameter. Moreover, the convex part 50 and the recessed part 52 of the dense area 42b have the same diameter. The diameters of the convex portions 50 and the concave portions 52 of the dense region 42b are smaller than the diameters of the convex portions 46 and the concave portions 48 of the sparse region 42a.

  4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 4 shows the convex portion 46 and the concave portion 48 of the sparse region 42a. In the width direction (L direction), the convex portion 46 is provided at the center of the channel 42, while the concave portion 48 is provided at both ends of the channel 42. Similarly, the convex part 50 of the dense region 42b is provided at the center in the width direction, and the concave part 52 of the dense region 42b is provided at both ends in the width direction.

  5 is a cross-sectional view taken along the line VV in FIG. FIG. 5 shows the recess 48 and the battery cell 22 in the sparse region 42a. In FIG. 5, the illustration of the spacer 24 is omitted. The surface 22 a of the battery cell 22 is a surface facing the stacking direction (W direction), which is a surface on the downstream side of the battery cell 22 and is a surface facing the adjacent battery cell 22. The end 48a of the recess 48 is disposed at a position on the extended line of the surface 22a. That is, the recess 48 is formed on the inner surface of the lower case 40 so that the position of the end 48 a of the recess 48 matches the position on the extension line of the downstream end of the battery cell 22. The concave portion 52 of the dense region 42 b is also arranged in the same manner as the concave portion 48. By adopting this configuration, it becomes easier for cooling air to enter between two battery cells 22 adjacent to each other, and the battery cells 22 can be efficiently cooled.

  As described above, in this embodiment, the sparse region 42a is formed on the upstream side of the flow of the cooling air, and the dense region 42b is formed on the downstream side. Cooling air is sent from the cooling blower 70 to the sparse area 42a. In the sparse region 42a, the cooling air repeatedly collides with the plurality of convex portions 46. As a result, the cooling air flows downstream while diffusing. In the dense region 42b, the cooling air repeatedly collides with the plurality of convex portions 50. As a result, the cooling air flows downstream while diffusing.

  On the upstream side close to the cooling blower 70, the flow velocity of the cooling air is too high (the wind is too strong), so that the cooling air that is cold flows before the upstream side is sufficiently cooled. Therefore, generally, the downstream side tends to be cooled, and the upstream side tends to be difficult to cool. In the present embodiment, the area of the air flow path formed per unit area in the sparse region 42a (upstream side) is larger than the area of the air flow path formed per unit area in the dense region 42b (downstream side). . Therefore, the resistance of the air flow on the upstream side is reduced, and the resistance of the air flow on the downstream side is increased. As a result, the cooling air easily flows on the upstream side, and the upstream side is easily cooled in the same manner as the downstream side. As a result, it is possible to eliminate the temperature variation of the battery cell 22 between the upstream side and the downstream side. According to the present embodiment, it is possible to eliminate variations in the temperature of the battery cells 22 without increasing the size of the cooling blower 70 and the intake duct 72.

  Further, the cooling air easily collides with the convex portions 46 and 50 and diffuses in the width direction (L direction). Thereby, it is possible to sufficiently cool the end portion in the width direction of the battery cell 22.

  FIG. 5 shows an example of the flow of cooling air. Reference numeral 100 in FIG. 5 indicates the flow of cooling air. The cooling air easily flows upward (H direction) along the shape of the recess 48. Thereby, cooling air is blown against the battery cells 22 from below. As a result, the battery cell 22 can be efficiently cooled. Further, the end portions of the recesses 48 and 52 are arranged at positions on the extension line of the end portion of the battery cell 22. Thereby, it becomes easy for cooling air to enter between two battery cells 22 adjacent to each other, and the battery cells 22 can be efficiently cooled.

  In addition, it becomes possible by using the cylindrical convex parts 46 and 50 to suppress the increase in the resistance of the air flow by the individual convex parts 46 and 50.

  Further, by providing the convex portion and the concave portion in the lower case 40, the strength of the lower case 40 is improved.

  The upper case 60 may be provided with a plurality of convex portions and a plurality of concave portions. Also in this case, the plurality of convex portions and the plurality of concave portions are densely arranged downstream from the upstream side. Of course, both the lower case 40 and the upper case 60 may be provided with a plurality of convex portions and a plurality of concave portions.

  10 battery pack, 20 battery module, 22 battery cell, 24 spacer, 26, 28 end plate, 30 restraint band, 40 lower case, 42, 62 channel, 42a sparse area, 42b dense area, 46, 50 convex part, 48, 52 Recess, 56 Lower air flow path, 60 Upper case, 66 Upper air flow path, 70 Cooling blower, 72 Intake duct.

Claims (1)

In a battery cooling device for cooling a battery module in which a plurality of battery cells are stacked,
A housing case that houses the battery module and into which cooling air is introduced;
A plurality of convex portions provided on the cooling air flow path in at least a part of the inner surface of the housing case;
A plurality of recesses provided on the cooling air flow path in at least a part of the inner surface of the housing case;
Have
The plurality of convex portions and the plurality of concave portions are provided more densely on the downstream side than the upstream side of the flow of the cooling air introduced into the housing case,
In a direction orthogonal to the stacking direction of the plurality of battery cells, the plurality of convex portions are provided at a central portion of the inner surface of the housing case, and the plurality of concave portions are formed at end portions of the inner surface of the housing case. Provided,
A battery cooling device.

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