JP2016081846A - Vehicle battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a temperature difference between portions of a battery case during heating to make temperatures of battery cells close to a uniform state.SOLUTION: A battery case 30 is provided with a battery cell housing space S and a hot air passage R. The battery case 30 includes ventilation means 37 which blows hot air in the hot air passage R to the battery cell housing space S.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle battery pack mounted on, for example, an electric vehicle or a hybrid vehicle.

  For example, an electric vehicle, a hybrid vehicle, and the like are equipped with a traveling motor for driving drive wheels and a vehicle battery for supplying electric power to the traveling motor. Since an electric vehicle or the like may travel in a cold region, the vehicle battery may be placed in a low temperature state. Assuming that the vehicle battery is cooled to, for example, below freezing point, the discharge performance may be extremely deteriorated to affect the running of the automobile.

  Thus, for example, as disclosed in Patent Document 1, a vehicle battery heating structure may be provided. In patent document 1, the heat generating body and the thermal storage material are provided in the battery case which accommodated the some battery cell. Furthermore, the battery case is provided with a shutter for opening and closing an opening formed in the battery case, and a blower unit for sending air into the battery case. Then, it can be switched between a heating mode in which the shutter is closed and the warm air is naturally convected in the battery case, and a cooling mode in which the shutter is opened and the air blowing unit is operated to introduce and discharge the cooling air into the battery case. It has become.

Japanese Patent No. 5464168

  However, in the heating mode of Patent Document 1, since the heat released from the heating element or the heat storage material is only convection naturally in the battery case, a temperature difference is likely to occur between the upper part and the lower part in the battery case, for example. As a result, the temperature of each battery cell in the battery case is different, and uniform heating cannot be performed, leading to a reduction in battery cell life.

  The present invention has been made in view of such a point, and an object of the present invention is to make the temperature difference of the battery cells close to uniform by reducing the temperature difference due to the part in the battery case in the heated state. .

In order to achieve the above object, the first invention provides:
Multiple battery cells;
A battery case containing the battery cell;
In the vehicle battery pack provided with a heating element for heating the air in the battery case,
The battery case is provided with a battery cell housing space for housing the battery cell, and a hot air passage through which the warm air heated by the heating element circulates and communicates with the battery cell housing space. The case is characterized in that it includes air blowing means for sending warm air in the warm air passage to the battery cell housing space.

  According to this configuration, since the warm air in the warm air passage is sent to the battery cell housing space by the blowing means, the warm air is forced to convect in the battery cell housing space. Thereby, since the temperature difference by the site | part of a battery cell accommodation space becomes small, the temperature of a some battery cell becomes close uniformly.

According to a second invention, in the first invention,
A partition wall for partitioning the battery cell housing space and the hot air passage is provided inside the battery case,
The heating element is provided on the partition wall.

  According to this structure, it becomes possible to arrange | position a heat generating body compactly. And since the heat of a heat generating body is transmitted to the air in a warm air path from the division wall for dividing a warm air path, warm air is efficiently generated in a warm air path.

According to a third invention, in the first or second invention,
The battery cell housing space is provided with auxiliary air blowing means for forcibly convection of air in the battery cell housing space.

  According to this configuration, since the warm air spreads to each part of the battery cell accommodation space, the temperature difference due to the portion of the battery cell accommodation space is further reduced.

According to a fourth invention, in any one of the first to third inventions,
The battery case is provided with a guide for guiding the warm air in the warm air passage to the battery cell housing space.

  According to this configuration, since the warm air in the warm air passage easily flows into the battery cell housing space, the heating performance of the battery cell is improved.

  According to the first aspect of the invention, since the air blowing means for sending the hot air in the hot air passage to the battery cell housing space is provided, the temperature difference due to the portion of the battery cell housing space can be reduced, and a plurality of battery cells The temperature can be made to be uniform.

  According to the second invention, since the heating element is provided on the partition wall for partitioning the battery cell housing space and the hot air passage, it is possible to efficiently generate the hot air while arranging the heating element in a compact manner. Can be quickly raised to a desired temperature.

  According to the third aspect of the invention, since the auxiliary air blowing means for forcibly convection of the air in the battery cell accommodation space is provided, the temperature of the battery cell can be made more uniform.

  According to the fourth invention, since the guide portion for guiding the warm air in the warm air passage to the battery cell accommodation space is provided, the heating performance of the battery cell can be improved.

1 is a perspective view of a vehicle battery pack according to Embodiment 1. FIG. It is the II-II sectional view taken on the line in FIG. 6 is a perspective view of a vehicle battery pack according to Embodiment 2. FIG. It is the IV-IV sectional view taken on the line in FIG. It is the VV sectional view taken on the line in FIG. 6 is a partial cross-sectional view of a vehicle battery pack according to a modification of Embodiment 2. FIG.

  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 perspective view of a vehicle battery pack 1 according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view of the vehicle battery pack 1.

  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 module 20 is arranged in the battery case 30 so as to be aligned in the longitudinal direction of the battery case 30.

  As shown in FIG. 2, the battery module 20 has a plurality of battery cells 21. The battery cell 21 is a secondary battery formed in a cylindrical shape, for example, and is accommodated in a posture state extending in the vertical direction. The battery module 20 has an electrode plate (not shown). Battery cells 21 are connected in series by electrode plates. Further, the battery modules 20 can be connected in series or in parallel.

  The battery case 30 is divided into an upper member 31 and a lower member 32 at an intermediate portion in the vertical direction. A bulging portion 31b that bulges upward is formed on one side in the longitudinal direction of the upper wall portion 31a of the upper member 31. The battery module 20 is housed inside the bulging portion 31b. That is, the battery module 20 is accommodated so as to be vertically stacked on one side in the longitudinal direction of the battery case 30. In addition, a peripheral wall portion 31c extending downward is integrally formed on the peripheral edge portion of the upper wall portion 31a of the upper member 31. An upper flange 31d is formed at the lower end of the peripheral wall portion 31c.

  A peripheral wall portion 32 b extending upward is integrally formed on the peripheral edge portion of the bottom wall portion 32 a of the lower member 32. A lower flange 32c is formed at the upper end of the peripheral wall portion 32b. The lower flange 32c overlaps the upper flange 31d, and the upper member 31 and the lower member 32 are integrated by fastening the lower flange 32c and the upper flange 31d with a fastening member or the like. It has become. Air is prevented from entering and exiting between the upper member 31 and the lower member 32.

  As shown in FIG. 2, the battery modules 20 housed in the battery case 30 are arranged such that a gap is formed between adjacent ones. The gap between the battery modules 20 is set to be sufficiently wide so that warm air described later can be easily circulated. A gap through which warm air can flow is also provided between the battery module 20 and the bottom wall portion 32a.

  The battery case 30 is provided with a battery cell housing space S for housing the battery cells 21 and a hot air passage R. That is, a partition wall 34 for partitioning the battery cell accommodation space S and the hot air passage R is provided in the battery case 30 in the vicinity of the upper portion inside the battery case 30. The partition wall 34 can be made of, for example, a resin material having thermal conductivity, and is disposed below the inner surface of the upper wall portion 31a of the upper member 31 and is warmed by a space above the partition wall 34. An air passage R is formed, and a battery cell housing space S is formed by a space below the partition wall 34. The partition wall 34 is formed so as to follow the shape of the upper wall portion 31a of the upper member 31 as a whole, and a first wall portion 34a along the upper surface of the bulging portion 31b of the upper wall portion 31a, and a first wall portion It has the 2nd wall part 34b extended in the downward direction following 34a, and the 3rd wall part 34c extended in the longitudinal direction other side of the battery case 30 following the lower end part of the 2nd wall part 34b. Therefore, the warm air passage R has a shape that extends from one end in the longitudinal direction of the battery case 30 to the other end, and is bent upward at a portion where the bulging portion 32b is formed. Further, the hot air passage R extends to both ends of the battery case 30 in the width direction.

  The partition wall 34 is provided with a heating element 35 for heating the air in the battery case 30. Although the heat generating body 35 can be comprised by the plate-shaped metal electrically-conductive member which heat | fever-generates by supplying electric power, such as aluminum alloy, stainless steel, copper, etc., for example, it is not restricted to these. The heating element 35 is fixed to a surface of the partition wall 34 that faces the battery cell accommodation space S. Although not shown, the heating element 35 is provided with a positive electrode portion and a negative electrode portion, and a wiring extending from a battery, a control device or the like is connected to the positive electrode portion and the negative electrode portion. It has become. When the control device detects that the battery cell 21 is below a predetermined low temperature, power is supplied to the heating element 35. The heating element 35 may be fixed to the surface of the partition wall 34 facing the warm air passage R, may be fixed to both surfaces of the partition wall 34, or may be embedded in the partition wall 34. . The heating element 35 may be provided on the upper surface or side surface of the warm air passage R.

  A plurality of through holes 34d are formed in the first wall portion 34a, the second wall portion 34b, and the third wall portion 34c of the partition wall 34, respectively. The through hole 34d communicates with the battery cell housing space S and the hot air passage R, and a plurality of locations of the hot air passage R communicate with the battery cell housing space S by forming the through hole 34d.

  In addition, a plurality of projecting portions 34 e that project toward the hot air passage R are provided on the surface of the partition wall 34 that faces the hot air passage R. The protruding portion 34 e extends in the width direction of the battery case 30. The formation of the protrusion 34e increases the heat transfer area, and can also cause turbulent flow in the hot air flowing through the hot air passage R. Efficiently transmits the flowing warm air. The protruding portion 34e may extend in the longitudinal direction of the battery case 30 or may be a columnar protrusion. Moreover, you may provide a groove | channel (not shown) in the partition wall 34 with the protrusion part 34e instead of the protrusion part 34e. Further, the protruding portion 34e may be omitted.

  Further, the battery case 30 includes a fan 37 as a blowing means for sending the warm air in the warm air passage R to the battery cell accommodation space S. The configuration of the blowing means is not particularly limited, and a blower that can send air can be used. In this embodiment, the fan 37 is provided on the third wall portion 34c of the partition wall 34, but may be provided on the first wall portion 34a or the second wall portion 34b. The fan 37 of this embodiment is used for a conventionally known blower or the like, and is supplied with electric power when it is detected by a control device (not shown) that the battery cell 21 is below a predetermined low temperature. It is configured. The intake port of the fan 37 faces the battery cell housing space S, and the exhaust port faces the warm air passage R. Therefore, when the fan 37 operates, the air in the battery cell housing space S is sucked and discharged into the hot air passage R.

  A cooling air passage (not shown) through which the cooling air flows may be formed on the outer surface of the battery case 30. Thereby, when the battery cell 21 is in a high temperature state, the operation of the heating element 35 is stopped, and the battery cell 21 can be cooled by flowing the cooling air through the cooling air passage. Further, when the temperature of the battery cell 21 rises, only the fan 37 may be operated while the operation of the heating element 35 is stopped.

  Next, the case where the battery cell 21 of the vehicle battery pack 1 configured as described above is heated will be described. When the control device detects that the battery cell 21 is in a predetermined low temperature state, power is supplied to the heating element 35 and the fan 37. When power is supplied to the heating element 35, the heating element 35 generates heat. The heat of the heating element 35 is transmitted to the partition wall 34, and the air in the warm air passage R is heated by the heat transmitted to the partition wall 34. At this time, since the protrusion 34e is provided, a wide heat transfer area is ensured, and heating of the air in the hot air passage R is promoted.

  When the fan 37 is activated to suck the air in the battery cell housing space S and discharge it to the hot air passage R, the air in the hot air passage R is heated as described above to become hot air, and the hot air passes through the through-holes. 34d to the battery cell housing space S. Since the through holes 34d are formed in the respective portions of the partition wall 34, the hot air is simultaneously sent to a plurality of locations in the battery cell accommodation space S. The warm air sent to the battery cell housing space S gathers toward the air inlet of the fan 37 while flowing downward from above, and is discharged to the warm air passage R and heated again. Thus, by circulating the air in the battery case 30, the battery cell 21 can be efficiently heated. Further, since the hot air can be forcedly convected in the battery cell housing space S, it becomes possible to supply hot air to every corner of the battery cell housing space S, and each battery cell 21 is similarly heated. be able to. Further, since the heat of the heating element 35 is also radiated to the battery cell housing space S, the air in the battery cell housing space S is also heated.

  As described above, the vehicle battery pack 1 according to the first embodiment includes the fan 37 that sends the warm air in the warm air passage R to the battery cell housing space S. Thus, the temperature difference between the two parts can be reduced, and the temperature of the battery cell 21 can be made close to uniform.

  Further, since the heating element 35 is provided on the partition wall 34 for partitioning the battery cell housing space S and the hot air passage R, it is possible to efficiently generate hot air while arranging the heating element 35 in a compact manner. Can be quickly raised to the desired temperature.

(Embodiment 2)
3 to 5 show a vehicle battery pack 1 according to Embodiment 2 of the present invention. The vehicle battery pack 1 of the second embodiment is different from that of the first embodiment only in the heating structure of the battery cell 21. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different parts will be described.

  In the second embodiment, a plurality of fans 37 are provided in the first wall portion 34 a of the partition wall 34 at intervals in the width direction of the battery case 30, and the battery case 30 of the third wall portion 34 c of the partition wall 34 is provided. A plurality are provided at intervals in the width direction and the longitudinal direction. As a result, the amount of hot air supplied to the battery cell housing space S per unit time can be increased, and a sufficient amount of hot air can be supplied to a wide range of the battery cell housing space S.

  Further, the upper wall portion 31 a of the upper member 31 of the battery case 30 is provided with an upper protruding portion 39 that protrudes downward toward the warm air passage R. The upper protrusion 39 is disposed so as to face the opening of the through hole 34d of the partition wall 34, and guides the warm air in the warm air passage R toward the through hole 34d, that is, into the battery cell housing space S. It is a guide for guiding. Thereby, the warm air in the warm air passage R smoothly flows into the battery cell housing space S. A plurality of upper protrusions 39 are preferably provided, but may be one.

  Further, the bottom wall portion 32 a of the lower member 32 of the battery case 30 is provided with a lower protrusion 40 that protrudes upward toward the battery cell accommodation space S. The lower protrusion 40 is for guiding the warm air flowing through the battery cell housing space S so as to flow through the side of the battery module 20. A plurality of lower protrusions 40 are preferably provided, but may be one.

  In the battery cell housing space S, an auxiliary fan (auxiliary air blowing means) 38 for forcibly convection of the air in the battery cell housing space S is provided. The auxiliary fan 38 can be configured in the same manner as the fan 37. Similarly to the fan 37, the auxiliary fan 38 is provided on the first wall portion 34 a and the third wall portion 34 c of the partition wall 34. The fans 37 and the auxiliary fans 38 are alternately arranged in the width direction of the battery case 30. The auxiliary fan 38 sucks air in the battery cell housing space S from below and discharges it in the width direction and the longitudinal direction of the battery case 30 along the lower surface of the partition wall 34. Thereby, the flow of the warm air in the battery cell housing space S is sufficiently formed.

  The embodiment 2 also includes the fan 37 that sends the warm air in the warm air passage R to the battery cell housing space S, so that the temperature difference due to the site of the battery cell housing space S is reduced as in the first embodiment. The temperature of the battery cell 21 can be made close to uniform.

  Further, the auxiliary fan 38 can be omitted as in the modification shown in FIG. In this case, a fan 37 is provided above the partition wall 34. The partition wall 34 can be provided with an inclined plate portion 41 so as to protrude upward at the peripheral edge portion of the through hole 34d. The inclined plate portion 41 is inclined so that the side close to the fan 37 is located at the uppermost position and is located downward as it is away from the fan 37. Thereby, after the air discharged from the fan 37 to the warm air passage R is heated, it flows along the lower surface of the inclined plate portion 41 and is guided to the through hole 34d and easily flows into the battery cell housing space S. .

  Although not shown, a fan or the like as a blowing unit is provided in the battery cell housing space S, and the air discharged from the blowing unit is supplied to the hot air passage R and heated in the hot air passage R. The hot air may flow into the battery cell housing space S.

  In the first and second embodiments, the case where the battery modules 20 are arranged so as to be stacked in two stages in the vertical direction has been described. However, the present invention is not limited to this, and the present invention is applied to a case where the battery module 20 has only one stage. be able to.

  Further, the warm air passage R may be provided on the side portion of the battery case 30.

  In addition, a layer having good thermal conductivity such as nickel plating may be provided on the partition wall 34, so that the heat of the heating element 35 is more easily transmitted to the air flowing through the hot air passage R.

  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.

The vehicle battery pack cooling structure 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 Partition wall 35 Heat generating body 37 Fan (blowing means)
38 Auxiliary fan (auxiliary ventilation means)
39 Upper protrusion (upper protrusion)
R Hot air passage S Battery cell accommodation space

Claims (4)

A plurality of battery cells (21);
A battery case (30) for accommodating the battery cell (21);
In the vehicle battery pack (1) comprising a heating element (35) for heating the air in the battery case (30),
In the battery case (30), the battery cell accommodating space (S) for accommodating the battery cell (21) and the warm air heated by the heating element (35) circulate and the battery cell accommodating space ( A warm air passage (R) communicating with the battery case (30), and the battery case (30) is provided with a blowing means (37) for sending the warm air in the warm air passage (R) to the battery cell housing space (S). A battery pack (1) for a vehicle. In the vehicle battery pack (1) according to claim 1,
A partition wall (34) for partitioning the battery cell accommodation space (S) and the hot air passage (R) is provided inside the battery case (30),
The vehicle battery pack (1), wherein the heating element (35) is provided on the partition wall (34). In the vehicle battery pack (1) according to claim 1 or 2,
The battery cell storage space (S) is provided with auxiliary air blowing means (38) for forcibly convection of air in the battery cell storage space (S). ). In the vehicle battery pack (1) according to any one of claims 1 to 3,
The battery case (30) is provided with a guide (39) for guiding the warm air in the warm air passage (R) to the battery cell housing space (S). Vehicle battery pack (1).

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