JP2016085879A - Battery pack for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a vehicle battery pack having a heater and a cooling passage compact and to efficiently heat and cool it. A cooling passage S through which cooling air for cooling the battery cells 21 is provided outside the battery case 30. A heater H for heating the battery cells 21 is embedded in a wall portion 34 provided between the cooling passage S and the battery cell accommodation space R. [Selection diagram] Figure 1

Description

  The present invention relates to a vehicle battery pack mounted on, for example, an electric vehicle, a hybrid vehicle, and the like, and particularly relates to a technical field of a structure for heating and cooling a battery cell.

  For example, since an electric vehicle or the like may travel in a cold region, a vehicle battery pack for supplying power to a traveling motor may be placed in a low temperature environment. Assuming that the vehicle battery pack is cooled to, for example, below freezing point, the discharge performance may be extremely deteriorated to affect the running of the automobile.

  Therefore, for example, as disclosed in Patent Document 1, a heater for heating the vehicle battery pack may be provided. In patent document 1, the heater is comprised by providing a heater wire on the base material which consists of a board | plate material. And a heater is arrange | positioned at the upper surface of the battery pack for vehicles, and it heat | fever-generates with the electric power supplied to the heater line | wire, and can heat a vehicle battery pack.

  In addition, since the vehicular battery pack secures a large amount of electricity stored by a battery module in which a plurality of battery cells are connected, the amount of heat generated during charging and discharging increases, and a cooling structure is required (for example, patents). Reference 2).

  In Patent Document 2, a space is defined by a battery tray and a battery cover, and a plurality of battery modules are accommodated in the space. The battery tray is composed of an upper plate and a lower plate, and a cooling passage through which cooling air flows is formed between them. Then, the cooling air and the battery cells of the battery module exchange heat through the upper plate, and the battery cells are cooled.

Japanese Patent Application Laid-Open No. 2012-221776 Japanese Patent No. 5277362

  As described above, both the heater and the cooling passage are required for the vehicle battery pack. However, the heater of Patent Document 1 is disposed on the upper surface of the vehicle battery pack, and the cooling passage of Patent Document 2 is also used for the vehicle battery. Since it is provided on the upper side outside the pack, if both the heater and the cooling passage are provided, the vehicle battery pack is enlarged.

  There is also a demand for efficient use of the heat of the heater and a demand for efficient cooling.

  The present invention has been made in view of such points, and an object of the present invention is to make a vehicle battery pack having a heater and a cooling passage compact and to efficiently heat and cool the battery pack. is there.

  In order to achieve the above object, in the present invention, a heater is embedded in a wall portion provided between the cooling passage and the battery cell accommodating space.

The first invention is
In the vehicle battery pack (1) including a battery case (30) having a battery cell housing space (R) in which a plurality of battery cells (21) are housed,
Outside the battery case (30), a cooling passage (S) through which cooling air for cooling the battery cell (21) flows is provided,
A heater (H) for heating the battery cell (21) is embedded in the walls (34, 41a) provided between the cooling passage (S) and the battery cell housing space (R). It is characterized by.

  According to this configuration, since the heater is disposed using the wall portion between the cooling passage and the battery cell housing space, the vehicle battery pack is more compact than when the heater is separately provided outside.

  When the battery cell is in a low temperature state, since the heater is embedded in the wall portion, the heat of the heater is quickly and efficiently transmitted to the battery cell accommodation space through the wall portion so that the battery cell is heated. Is done. Further, when the battery cell is in a high temperature state, the cool air of the cooling air in the cooling passage is quickly and efficiently transmitted to the battery cell accommodation space through the wall portion, thereby cooling the battery cell.

According to a second invention, in the first invention,
Wall portions (34, 41a) provided between the cooling passage (S) and the battery cell housing space (R) are made of resin,
The heater (H) is insert-molded on the wall (34, 41a).

  According to this configuration, since the heater is embedded and integrated into the wall portion when the wall portion is molded, the heater can be held at a predetermined position without providing a member or the like for fixing the heater to the wall portion. Is possible.

According to a third invention, in the first invention,
The battery case (30) accommodates a connection member (23) connected to the electrode portion of the battery cell (21),
The heater (H) is arranged on the connecting member (23) side of the wall (34, 41a).

  According to this configuration, the heat of the heater can be easily transmitted to the battery cell via the connecting member, so that the battery cell can be heated more efficiently.

  According to the first aspect, since the heater is embedded in the wall portion between the cooling passage and the battery cell housing space, the vehicle battery pack having the heater and the cooling passage can be made compact. Furthermore, since the heat of the heater and the cooling air of the cooling passage can be transmitted to the battery cell quickly and efficiently, the battery cell can be efficiently heated and cooled.

  According to the second invention, since the heater is insert-molded on the wall portion, the heater can be held at a predetermined position on the wall portion without increasing the number of parts.

  According to the third invention, since the heater is arranged on the side of the connecting member connected to the electrode portion of the battery cell, the battery cell can be heated more efficiently.

1 is a cross-sectional view of a vehicle battery pack according to Embodiment 1. FIG. FIG. 3 is a view corresponding to FIG. 1 according to a second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.
(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a vehicle battery pack 1 according to Embodiment 1 of the present invention, showing a cross section cut in the flow direction of cooling air.

  The battery pack 1 includes a plurality of battery modules 20 and a battery case 30 that houses these battery modules 20. The battery pack 1 is mounted on, for example, an electric vehicle, a hybrid vehicle, or the like and supplies electric power to a traveling motor. A hybrid vehicle includes a plug-in type.

  The battery case 30 is configured, for example, in a box shape that is long in a predetermined direction. The battery modules 20 are arranged in the battery case 30 so as to line up in the longitudinal direction of the battery case 30 and also arranged in the width direction of the battery case 30.

  The battery module 20 includes a plurality of battery cells 21 and a cell case 22 that houses the battery cells 21. The battery cell 21 is a secondary battery formed in a cylindrical shape, for example, and is accommodated in the cell case 22 in a posture extending in the vertical direction. The cell case 22 can be configured by combining, for example, resin members divided in the vertical direction. In the cell case 22, the battery cells 21 are arranged so as to be aligned in the longitudinal direction of the battery case 30, and are also aligned in the width direction of the battery case 30. An attachment portion 22a attached to the battery case 30 is provided on the side surface of the cell case 22 so as to protrude.

  The battery case 30 includes an upper wall portion 31 extending in the longitudinal direction of the battery case 30, a side wall portion 32 extending downward from a peripheral edge portion of the upper wall portion 31, and a bottom wall portion 34. It is a resin molded product consisting of A space defined by the upper wall portion 31, the side wall portion 32, and the bottom wall portion 34 is a battery cell housing space R for housing the battery cell 21. It is difficult for outside air to enter and leave the battery cell housing space R. The attachment portion 22 a of the cell case 22 is fixed to the side wall portion 32 of the battery case 30.

  The upper wall part 31, the side wall part 32, and the bottom wall part 34 of the battery case 30 can be integrally formed. The battery case 30 houses a bus bar 23 (connecting member) connected to the electrode portion (negative electrode portion) of the battery cell 21. The bus bar 23 is a member constituting a part of the battery module 20, and is made of a metal plate material such as a copper plate that easily conducts electricity and has thermal conductivity. The bus bar 23 is disposed on the lower surface of the battery module 20, and extends along the bottom wall portion 34 between the lower surface of the battery module 20 and the inner surface of the bottom wall portion 34 of the battery case 30.

  A cooling passage S is provided outside the battery case 30. In this embodiment, the cooling passage S is located below the battery case 30. The cooling passage S is a passage through which cooling air for cooling the battery cells 21 flows, and extends in the left-right direction in FIG. Although not shown, cooling air is blown into the cooling passage S by a blower or the like. The blower is controlled by a control device (not shown), and is configured to operate when the temperature of the battery cell 21 reaches a predetermined high temperature state, for example.

  The cooling passage S is provided inside a resin passage constituent member 41. The passage member 41 is a duct-like member disposed so as to be adjacent to the lower surface of the bottom wall portion 34 of the battery case 30, and is separated downward from the upper wall portion 41a and the upper wall portion 41a by a predetermined dimension. The lower wall portion 41b and the side wall portion 41c are arranged. The upper wall portion 41a of the passage constituting member 41 and the bottom wall portion 34 of the battery case 30 overlap each other. A plurality of cooling passages S may be provided inside the passage constituting member 41. Further, the upper wall portion 41 a of the passage constituting member 41 may be integrally formed with the bottom wall portion 34 of the battery case 30.

  In this embodiment, a heater H for heating the battery cell 21 is provided. The heater H is disposed on the upper side of the bottom wall portion 34 of the battery case 30, that is, on the bus bar 23 side of the battery module 20, and is embedded in the bottom wall portion 34, and extends along the bottom wall portion 34. . The bottom wall portion 34 of the battery case 30 and the upper wall portion 41a of the passage constituting member 41 are wall portions provided between the cooling passage S and the battery cell accommodating space R.

  The heater H is composed of a plate-shaped metal conductive member made of, for example, aluminum alloy, stainless steel, copper, or the like. Although not shown, the heater H is provided with a positive electrode portion and a negative electrode portion. A portion of the heater H between the positive electrode portion and the negative electrode portion extends while being bent in a plan view, and is configured to uniformly heat a wide range. The heater H can be integrally formed by etching a thin plate material. The positive electrode part, the negative electrode part and the bent part may be formed by punching a thin plate material. The thickness of the thin plate material can be set, for example, in a range of 0.3 mm to 1.0 mm. The heater H is controlled by a control device (not shown), and is configured to be energized when it is detected that the battery cell 21 is in a predetermined low temperature state. The heater H can also be comprised, for example with a heating wire.

  The heater H can be insert-molded in the bottom wall portion 34 of the battery case 30. That is, after the heater H is set in a molding die (not shown) for molding the bottom wall portion 34, the molten resin material is injected into the molding die, molded, and then solidified so that the heater H is embedded. A wall 34 is obtained.

  The heater H may be attached to the bottom wall portion 34 of the battery case 30. In this case, a recess is formed in the bottom wall portion 34 of the battery case 30 to accommodate the heater H, the heater H is disposed in the recess, and is attached to the inner surface of the recess using an adhesive or the like.

  An insulating member B is arranged on the upper surface of the heater H. The insulating member B is formed in a sheet shape that covers the upper surface of the heater H, and has thermal conductivity. Between the insulating member B and the bus bar 23, a heat conductive gel A for increasing the heat conductivity is provided. Since this heat conductive gel A is conventionally well-known, detailed description is abbreviate | omitted. Instead of the heat conductive gel A, a heat conductive sheet may be provided.

  Next, the case where the battery pack 1 for vehicles comprised as mentioned above is used is demonstrated. When the battery cell 21 is detected by a temperature sensor or the like to be in a predetermined low temperature state, the heater H is energized. At this time, the blower that blows air to the cooling passage S is stopped to prevent the heat of the heater H from escaping to the outside.

  When the heater H generates heat, the heat of the heater H is transmitted to the bottom wall portion 34 of the battery case 30. The heat of the bottom wall portion 34 is transmitted to the bus bar 23 via the heat conductive gel A, and is transmitted to the battery cell 21 via the bus bar 23 to heat the battery cell 21. Since the bus bar 23 is a metal plate and is directly connected to all the battery cells 21 constituting the battery module 20, the heat of the heater H is efficiently transmitted to all the battery cells 21.

  Further, since the heater H is embedded in the bottom wall portion 34 of the battery case 30, the heat of the heater H is quickly and efficiently transmitted to the battery cell accommodation space R via the bottom wall portion 34 to be transferred to the battery cell 21. Is warmed. When the temperature of the battery cell 21 rises to a temperature at which there is no problem with charging / discharging, energization to the heater H is stopped.

  On the other hand, when it is detected that the battery cell 21 is in a predetermined high temperature state, the blower is activated. When the cooling air is supplied to the cooling passage S by the blower, the cooling heat of the cooling air is quickly and efficiently transmitted to the battery cell housing space R via the bottom wall portion 34 of the battery case 30 so that the battery cell 21 is To be cooled. At this time, since the heater H is stopped, the cooling air is transmitted to the battery cell 21 through the bottom wall portion 34 of the battery case 30, the heat conductive gel A, and the bus bar 23 in this order. To be cooled. This also cools the battery cell 21 efficiently.

  As described above, according to the vehicle battery pack 1 according to the first embodiment, the heater H is embedded in the bottom wall portion 34 of the battery case 30 located between the cooling passage S and the battery cell housing space R. Therefore, the vehicle battery pack 1 having the heater H and the cooling passage S can be made compact compared to the case where the heater H is separately provided outside the cooling passage S. Furthermore, since the heat of the heater H and the cooling air of the cooling passage S can be quickly and efficiently transmitted to the battery cell 21, the battery cell 21 can be efficiently heated and cooled.

  Further, since the heater H can be embedded and integrated into the bottom wall portion 34 when the bottom wall portion 34 of the battery case 30 is molded, the heater H can be provided without providing a member or the like for fixing the heater H to the bottom wall portion 34. Can be held at a predetermined position, and the number of parts can be reduced.

(Embodiment 2)
FIG. 2 shows a vehicle battery pack 1 according to a second embodiment of the present invention. The vehicle battery pack 1 according to the second embodiment has a heater H arrangement position relative to that of the first embodiment. Since the other parts are configured in the same manner as in the first embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted, and the different parts will be described in detail. .

  In the second embodiment, the heater H is embedded in both the bottom wall portion 34 of the battery case 30 and the upper wall portion 41 a of the passage constituting member 41. The outer surface of the heater H is covered with an insulating member C.

  Also in the case of the second embodiment, the heater H is embedded in the bottom wall portion 34 of the battery case 30 and the upper wall portion 41a of the passage component member 41 located between the cooling passage S and the battery cell housing space R. Compared with the case where H is separately provided outside the cooling passage S, the vehicle battery pack 1 having the heater H and the cooling passage S can be made compact.

  Further, similarly to the first embodiment, the heat of the heater H is transmitted to the battery cell 21 and the battery cell 21 is heated. Further, the cooling air of the cooling air in the cooling passage S is also transmitted to the battery cell 21 to cool the battery cell 21. Therefore, the battery cell 21 can be efficiently heated and cooled.

  The heater H may be embedded only in the upper wall portion 41a of the passage constituting member 41. In this case, the heater H can be insert-molded on the upper wall portion 41a of the passage constituting member 41.

  Further, a convex portion or a concave portion may be formed on the inner surface of the passage constituting member 41. Thereby, since the flow of the cooling air flowing through the passage constituting member 41 is disturbed, the cooling effect can be further enhanced.

  In the first and second embodiments, the cooling passage S is provided on the lower side of the battery module 20. However, the present invention is not limited to this, and the cooling passage S may be provided on the upper side or the side portion of the battery module 20. In this case, the heater H can be embedded in the side wall portion or the upper wall portion of the battery module 20.

  Further, the passage constituting member 41 can be integrally formed with the battery module 20 and the battery case 30. Further, the passage constituting member 41 may be provided inside the battery case 30.

  The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the vehicle battery pack according to the present invention can be used in, for example, an electric vehicle or a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 Battery pack 20 Battery module 21 Battery cell 30 Battery case 34 Bottom wall part 41 Path | route component 41a Upper wall part R Battery cell accommodation space S Cooling path

Claims (3)

In the vehicle battery pack (1) including a battery case (30) having a battery cell housing space (R) in which a plurality of battery cells (21) are housed,
Outside the battery case (30), a cooling passage (S) through which cooling air for cooling the battery cell (21) flows is provided,
A heater (H) for heating the battery cell (21) is embedded in the walls (34, 41a) provided between the cooling passage (S) and the battery cell housing space (R). A battery pack (1) for a vehicle. In the vehicle battery pack (1) according to claim 1,
Wall portions (34, 41a) provided between the cooling passage (S) and the battery cell housing space (R) are made of resin,
The vehicle battery pack (1), wherein the heater (H) is insert-molded on the wall (34, 41a). In the vehicle battery pack (1) according to claim 1,
The battery case (30) accommodates a connection member (23) connected to the electrode portion of the battery cell (21),
The vehicle battery pack (1), wherein the heater (H) is disposed on the connection member (23) side of the wall (34, 41a).

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