JP2007172982A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack having a cooling structure enabled to shorten the height of and downsize a battery pack for an electric automobile or the like, and capable of uniformly cooling a whole battery module. <P>SOLUTION: The battery pack is provided with a battery module 10 structured by laminating a plurality of cells 11 in a case, an inner air intake duct 8 supplying the battery module with a coolant guided into the case through a coolant guide port 8a, and an inner drainage duct 9 draining the coolant guided out of the battery module outside the case through the coolant drainage port 9a. The coolant guide-in port and the coolant drainage port are fitted to the same side of the case, and the coolant guide-in port induces the coolant passing through it in a first direction, while, the inner air intake duct is provided with a uniformalizing means for deflecting the coolant guided out of an outlet of the inner air intake duct in a second direction practically crossing the first direction to uniformalize flow velocity of the coolant guided out of an outlet of the inner air intake duct toward the first direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery pack mounted on an electric vehicle or the like.

  In recent years, an electric vehicle using an electric motor as a drive source and a so-called hybrid electric vehicle combining an electric motor and another drive source have been put into practical use. In such a vehicle, a battery for supplying electric energy to the electric motor is mounted. As this battery, for example, a secondary battery such as a nickel cadmium battery, a nickel hydride battery, or a lithium ion battery that can be repeatedly charged and discharged is used.

  Usually, the secondary battery is configured as a battery module in which battery cells are stacked, and is mounted on a vehicle or the like in a state where the battery module is accommodated in a casing. This casing, the battery module and other components housed in the casing are referred to as a battery pack.

  The battery module generates heat due to an internal electrochemical reaction, and its temperature rises. Since the power generation efficiency of the battery module decreases when the temperature rises, for example, cooling air or the like is introduced into the housing from the outside to cool the battery module.

  Various types of battery pack cooling structures using this cooling air have been proposed. For example, the battery module is accommodated in the housing in an inclined state in the longitudinal direction so that the refrigerant is uniformly supplied in the longitudinal direction of the battery module, and the cross-sectional area of the cooling air supply path to the battery cell is set upstream. A method has been proposed in which the pressure is lowered toward the downstream side (Patent Document 1).

In addition, the battery pack is required to have a low profile due to the mounting space when the battery pack is mounted on the vehicle. Therefore, normally, the intake fan and the exhaust fan of the battery pack are arranged so as to protrude from both side surfaces sandwiching the longitudinal direction of the battery module.
Japanese Unexamined Patent Publication No. 7-320794

  However, when the height of the battery pack is reduced by the above-described arrangement, the battery module intake fan and exhaust fan are arranged on the opposite side of the battery pack, so that the battery pack cannot be sufficiently downsized. There is a problem that it cannot be installed.

  As a countermeasure for this problem, it is conceivable to configure the cooling flow path of the battery pack so that the intake fan and the exhaust fan can be installed on the same side of the battery pack. It is necessary to deflect the flow of cooling air, and it is difficult to maintain a uniform flow of cooling air supplied to the battery module. Therefore, there exists a problem that temperature distribution arises in a battery module and favorable performance cannot be obtained.

  The present invention has been made in view of such problems, and it is possible to reduce the height and size of the battery pack and to provide a battery pack having a cooling structure capable of uniformly cooling the entire battery module. The issue is to provide.

  In order to solve the above-described problems, in the present invention, a battery module configured by stacking a plurality of cells in a casing, and an interior for supplying the refrigerant introduced into the casing through the refrigerant inlet to the battery module. A battery pack having an intake duct and an internal exhaust duct for discharging the refrigerant derived from the battery module to the outside of the housing via the refrigerant discharge port, wherein the refrigerant introduction port and the refrigerant discharge port are Installed on the same surface side of the body, the refrigerant introduction port guides the refrigerant passing through the refrigerant introduction port in the first direction, the internal intake duct, the refrigerant derived from the outlet of the internal intake duct, Uniform to deflect in a second direction substantially perpendicular to the first direction and to make the flow rate of the refrigerant derived from the outlet of the internal intake duct uniform with respect to the first direction Battery pack, characterized in that Provided.

  By defining the structure of the battery pack in this way, the battery pack can be reduced in height and size. In addition, since a means for equalizing the flow rate of the refrigerant is provided in the internal intake duct, turbulent flow is not easily generated even if the flow of the refrigerant is deflected in the internal intake duct, and the refrigerant can be supplied uniformly to the battery module. It becomes.

  Here, the uniformizing means includes a plurality of slits installed on the bottom or top surface of the internal intake duct, and a baffle plate that covers a part of the plurality of slits, and each of the plurality of slits is Each of the outlets of the internal air intake duct has an opening, and is installed so as to partition the bottom surface or the upper surface of the internal air intake duct substantially without being cut along the second direction. Installed in contact with the upper end surface or the lower end surface of the slit, and in the first direction, extends from one side end surface of the internal intake duct substantially perpendicular to the first direction to the other side end surface. In the second direction, the most upstream side end surface among the side end surfaces substantially perpendicular to the second direction of the internal intake duct so that the refrigerant is supplied to the upstream side of each slit. Gap between It may be.

  By configuring the uniformizing means installed in the internal intake duct in this way, the above-described effects can be easily obtained.

  The width of the baffle plate in the second direction is preferably about 1/2 of the width of the internal intake duct in the same direction. Thereby, the time which passes the slit of a refrigerant | coolant becomes long, and the flow velocity dispersion | variation in the refrigerant | coolant derived | led-out from the outlet of an internal intake duct is further suppressed.

  In addition, it is preferable that the slit width and the installation interval in the first direction of the plurality of slits are constant. As a result, a suitable refrigerant supply structure for the internal intake duct can be obtained without increasing the design parameters so much.

  Further, the first direction may be a direction substantially parallel to the cell stacking direction. Thereby, it becomes possible to cool each laminated battery cell more uniformly.

  In the battery pack of the present invention, since the introduction part of the refrigerant into the housing and the exhaust part are installed on the same side surface of the housing, the battery pack can be reduced in height and size. Further, since the refrigerant is uniformly supplied to the battery module by the flow velocity equalizing means provided in the internal intake duct, the entire battery module can be uniformly cooled.

  Embodiments based on the present invention will be described below.

  FIG. 1 shows an example of a mounting state of a battery pack in a vehicle according to the present embodiment.

  In FIG. 1, the battery pack 1 is mounted on the rear side of the rear seat 500 of the vehicle. However, it should be noted that the mounting location of the battery pack 1 is not particularly limited. As the refrigerant introduced into the battery pack 1, for example, cooling air by air in the vehicle compartment is used. The same side surface of the battery pack 1 includes an external intake duct 80 for guiding the air in the vehicle interior to the battery pack 1 and an external exhaust duct 90 for exhausting the cooling air introduced into the battery pack 1 to the outside. It is connected to.

  FIG. 2 is a block diagram when the vehicle 100 is driven by a battery system having a battery pack according to the present invention. The vehicle 100 includes a control unit 101, a battery unit 102 including a battery pack, and a drive unit 103. The control unit 101 is installed in a device box 30 (see FIG. 3) arranged inside the battery pack 1, and controls the battery 102 and the drive unit 103. The drive unit 103 may include an internal combustion engine such as a gasoline engine or a diesel engine in addition to an electric motor such as a motor driven by a current supplied from the battery unit 102. That is, the vehicle 100 includes not only an electric vehicle but also a hybrid car provided with a driving means other than an electric motor such as a gasoline engine.

  FIG. 3 is a perspective view of the battery pack of the present invention, and FIG. 4 is a schematic cross-sectional view taken along the line III-III of the battery pack shown in FIG. Note that the cooling structure of the battery pack 1 of this embodiment is a so-called upflow type in which the refrigerant flows from the bottom to the top in the battery module. In each figure, the white arrow indicates the flow of the refrigerant. In the following description, the case where this refrigerant is cooling air will be described as an example. However, it will be apparent to those skilled in the art that the refrigerant is not limited to this in the present invention.

  As shown in FIG. 3 and FIG. 4, the battery pack 1 includes a housing 2 composed of an upper case 3 and a lower case 4, a battery module 10 disposed inside the housing 2, an internal intake duct 8, and an internal An exhaust duct 9 and an equipment box 30 are provided.

  The housing 2 is configured by combining the upper case 3 and the lower case 4 and fastening the ends with bolts 33, and has a space inside.

  The battery module 10 is configured by stacking a plurality of battery cells 11 as shown in FIG. As the battery cell, for example, a secondary battery such as a nickel cadmium battery, a nickel hydrogen battery, or a lithium ion battery can be used. The battery cell 11 has a so-called square plate-like outer shape.

  Projections 11a are provided on the side surfaces of the individual battery cells 11 (both ends in the Y direction in FIG. 4), and the projections 11a extend to the side surfaces of the battery module 10 after the battery cells 11 are stacked. Parts. End plates 15 that maintain the stacked state of the battery modules 10 are disposed at both ends in the stacking direction (X direction) of the battery modules 10 (see FIG. 5). They are connected by a blanket 26 and a restraining belt 16 (see FIG. 4) that engage with protrusions formed on the side surfaces.

  Convex portions (not shown) are provided on the main surface (both end surfaces in the X direction) of each battery cell 11, and cooling air is circulated between the stacked battery cells 11 by this convex portion. A part of the passage (hereinafter referred to as “cooling passage”) is formed. In the present embodiment, the battery module 10 is installed so as to have a predetermined angle of inclination with respect to the bottom surface of the lower case 4 (inclination in the Y direction in FIG. 4). This is because the cooling air discharged from the internal intake duct 8 is uniformly supplied to the lower surface side of the battery module 10.

  The internal space of the housing 2 is partitioned by the battery module 10. An upper space is formed between the upper surface of the battery module 10 and the upper case 3, and the upper cooling flow path 5 is shaped by this upper space. Further, a lower space is formed between the lower surface of the battery module 10 and the lower case 4, and the lower cooling flow path 6 is shaped by this lower space. Therefore, the cooling channel is constituted by the space in which the upper cooling channel 5, the lower cooling channel 6 and the battery module 10 are installed (the cooling channel formed by the above-described convex portions). Between one of the side end surfaces (side end surfaces orthogonal to the Y direction) of the battery module 10 parallel to the stacking (X) direction of the cells 11 and the side surfaces of the upper case 3 and the bottom case 4 facing this, the first Side space 7a is formed. Further, between the other of the side end faces (side end faces orthogonal to the Y direction) of the battery module 10 parallel to the stacking (X) direction of the cells 11 and the side surfaces of the upper case 3 and the bottom case 4 facing each other, Two side spaces 7b are formed.

  A gasket 23 is installed between the upper cooling flow path 5, the first side space 7a, and the second side space 7b, and airtightness between these spaces is ensured. Further, a gasket 23 is installed between the lower cooling flow path 6 and the first side space 7a and the second side space 7b, and the confidentiality between these spaces is ensured. For this gasket 23, for example, an independent foamed EPDM rubber or the like is used.

  An internal intake duct 8 and an internal exhaust duct 9 are installed in the first side space 7a and the second side space 7b located on the side surface side of the battery module 10, respectively. As shown in FIG. 3, an intake port 8a is provided on one surface of the housing so that the cooling air is supplied in the longitudinal direction (X direction) of the internal intake duct 8, and the internal intake duct 8 It communicates with the mouth 8a. Further, an exhaust port 9a is provided on the same housing surface as the surface on which the intake port 8a is provided so that the cooling air is discharged in the longitudinal direction (X direction) of the internal exhaust duct 9, and the internal exhaust duct 9 Communicates with the exhaust port 9a. The internal intake duct 8 corresponds to a communication portion that connects the intake port 8a corresponding to the cooling air introduction port and the lower cooling channel 6 that is a part of the cooling channel. Similarly, the internal exhaust duct 9 corresponds to a communication portion that connects the exhaust port 9a corresponding to the cooling air outlet and the upper cooling channel 5 that is a part of the cooling channel.

  As described above, according to the battery pack 1 of the present invention, the introduction portion of the cooling air to the housing and the exhaust portion are installed on the same side surface of the housing, so that the battery pack can be reduced in height and size. .

  However, in the battery pack cooling structure of the present invention, after the cooling air is introduced into the internal intake duct 8, it is necessary to deflect the cooling air toward the battery module 10 (more precisely, the lower cooling flow path 6). In general, the deflection of the cooling air causes turbulence and eddy currents. In such a situation where the turbulent flow or vortex of the cooling air is generated, the cooling air introduced from the internal intake duct 8 through the lower cooling flow path 6 is not uniformly supplied to the battery module 10 side, and is locally supplied to the battery module. Temperature rise may occur. Such a local temperature rise of the battery module may deteriorate the battery performance and impair the reliability of the battery. On the other hand, the present invention is characterized in that a flow velocity equalizing means is provided in the internal intake duct 8 for the purpose of suppressing such uneven distribution of cooling air on the battery module 10 side. That is, even if the cooling air is deflected in the internal intake duct 8, not only the generation of turbulence and vortex is effectively suppressed by the flow velocity equalizing means of the present invention, but also the deflected cooling air is It is possible to keep the flow velocity when introduced from the internal intake duct 8 into the lower cooling flow path 6 constant in the stacking (X) direction of the cells 11. Therefore, uniform cooling air can be supplied to the entire battery module, and local temperature rise of the battery module can be suppressed.

  Hereinafter, the flow velocity equalizing means provided in the internal intake duct 8 will be described with a specific example. Note that the structure of the internal exhaust duct 9 is not particularly limited when the effects of the present invention are manifested. Therefore, the internal exhaust duct 9 may have a conventional structure.

  FIG. 5 shows the positional relationship between the internal intake duct 8, the internal exhaust duct 9, and the battery module 10. FIG. 6 shows an enlarged perspective view of a portion surrounded by VI in FIG. Further, FIG. 7 shows a VV cross-sectional view of the internal intake duct 8 of FIG. The internal intake duct 8 has three surfaces perpendicular to the Y direction (first surface 8d1, second surface 8d2, and third surface 8d3 in order from the upstream side in the direction of cooling air flow along the Y direction, respectively). Have The internal intake duct 8 has two surfaces, 8c1 and 8c2, which are perpendicular to the X direction. On the third surface 8d3 of the internal intake duct 8, openings corresponding to each of the plurality of slits 55 provided in the internal intake duct 8 are provided in a row. The plurality of slits 55 extend along the Y direction on the bottom surface of the internal intake duct 8, and extend from the third surface 8d3 to the first surface 8d1 of the internal intake duct 8 on the bottom surface of the internal intake duct 8. It is installed to partition. 5 and 6, the intervals between the slits 55 are shown at equal intervals, but the embodiment of the present invention is not limited to this, and the intervals between the slits 55 gradually decrease as the distance from the intake port increases. It may be set to. However, in order to avoid an increase in design parameters, it is preferable that the slit intervals are equal.

  Further, a baffle plate 50 is installed immediately above each slit 55 so as to be in contact with the upper end surface of the slit 55. In the X direction, the baffle plate 50 extends from one surface 8c1 perpendicular to the X direction of the internal intake duct 8 to the other surface 8c2. One end in the Y direction of the baffle plate 50 is in contact with the second surface 8d2 (or the third surface 8d3) of the internal intake duct 8, but the other end in the Y direction is in contact with the first surface 8d1. Not. Therefore, the cooling air introduced into the internal intake duct 8 flows into each slit 55 through the gap formed between the baffle plate 50 and the first surface 8d1 of the internal intake duct 8 in the internal intake duct 8. Is done.

  By configuring the internal structure of the internal intake duct 8 in this way, the following effects are produced. First, since the slit 55 is provided inside the internal intake duct 8, it becomes possible to significantly prevent the cooling air from being disturbed when the flow of the cooling air is deflected. In addition, since the baffle plate 50 is provided, it is possible to secure a sufficient flow velocity stabilization distance before the cooling air passing through the slit is introduced into the lower cooling flow path 6, so that the air is discharged from each slit 55. It becomes possible to maintain the flow rate of the cooling air to be constant.

  Here, the dimension W2 in the Y direction of the baffle plate 50 is about 1/2 of the dimension W1 between the first surface 8d1 and the second surface 8d2 of the internal intake duct 8, as shown in FIG. It is preferable. If the dimension W2 of the baffle plate 50 is extremely shorter than this, a sufficient stabilization distance of the cooling air passing through the slits cannot be secured, and the cooling air flow velocity discharged from each slit 55 is likely to vary. Because it becomes. In addition, if W2 is significantly longer than 1/2 of W1, the pressure loss in the internal intake duct 8 becomes high, and there is a possibility that sufficient cooling air cannot be introduced into the battery module 10. .

  As described above, in the battery pack 1 of the present invention, the cooling that occurs when the cooling air is deflected in the internal intake duct 8 even when the introduction portion of the cooling air to the housing and the exhaust portion are installed on the same side surface of the housing. Wind turbulence and uneven flow velocity can be suppressed. Further, the flow velocity of the cooling air derived from the outlet of the internal intake duct 8 can be made uniform in the X direction. Accordingly, the cooling air can be supplied uniformly from the internal intake duct 8 to the entire battery module 11. As a result, the battery pack 1 can be lowered in height, and the battery module 10 can be uniformly cooled, thereby suppressing a local temperature rise.

  In the above description, the case where a baffle plate and a slit are provided as an example of the flow velocity equalizing means of the internal intake duct 8 has been described as an example, but if the same effect is obtained, the flow velocity equalizing means of the present invention is applied to this. It should be noted that it is not limited.

  In each of the above embodiments, the case where air in the vehicle compartment is used as the refrigerant of the battery pack 1 has been described as an example, but other refrigerant gas or liquid may be used. These refrigerants may be circulated through a heat exchanger or the like.

  In the above description, the configuration in which the battery module 10 is inclined at a predetermined angle with respect to the bottom surface of the bottom case 4 in the upflow type cooling structure is shown as an example. However, the present invention is not limited to the cooling structure of such a structure. For example, the downflow type cooling structure or the battery module 10 can be changed by simply changing the positional relationship of the flow velocity equalizing means with respect to the internal intake duct 8. The present invention can also be applied to a structure arranged in parallel with the bottom surface of the bottom case 4 (for example, the above-described slit 55 is installed on the upper surface of the internal intake duct 8 and the baffle plate is installed so as to be in contact with the lower end surface of the slit, etc. Can be applied to battery packs with a down-flow type cooling structure). Furthermore, in the present invention, it should be noted that the internal intake duct, the battery module, and the internal exhaust duct may be configured in any arrangement relationship as long as the same effect can be obtained.

It is a figure which shows the mounting state to the vehicle of a battery pack. It is a block diagram in the case of driving a vehicle with a battery system having a battery pack according to the present invention. 1 is a schematic perspective view of a battery pack according to the present invention. FIG. 4 is a schematic cross-sectional view taken along line III-III in FIG. FIG. 3 is an exploded perspective view showing a positional relationship between an internal intake duct, an internal exhaust duct, and a battery module of the battery pack according to the present invention. FIG. 6 is an enlarged view of a portion surrounded by VI in FIG. FIG. 7 is a VV cross-sectional view of the internal intake duct of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery pack 2 Case 3 Upper case 4 Lower case 5 Upper cooling flow path 6 Lower cooling flow path 7a 1st side space 7b 2nd side space 8 Internal intake duct 8a Intake port 8c1, 8c2 Surface perpendicular to X direction 8d1 First surface perpendicular to Y direction of internal intake duct 8d2 Second surface perpendicular to Y direction of internal intake duct 8d3 Third surface perpendicular to Y direction of internal intake duct 9 Internal Exhaust duct 9a Exhaust port 10 Battery module 11 Cell 11a Protruding portion 15 End plate 30 Equipment box 33 Bolt 50 Baffle plate 55 Slit 80 External intake duct 90 External exhaust duct 100 Vehicle 101 Control unit 102 Battery unit 103 Drive unit 500 Rear seat.

Claims (5)

A battery module configured by stacking a plurality of cells in the housing, an internal intake duct for supplying the refrigerant introduced into the housing through the refrigerant inlet in the direction of the battery module, and from the direction of the battery module An internal exhaust duct that discharges the derived refrigerant to the outside of the housing through the refrigerant discharge port, and a battery pack,
The refrigerant introduction port and the refrigerant discharge port are installed on the same surface side of the housing, the refrigerant introduction port guides the refrigerant passing through the refrigerant introduction port in a first direction,
The internal intake duct deflects the refrigerant derived from the outlet of the internal intake duct in a second direction substantially perpendicular to the first direction and is extracted from the outlet of the internal intake duct A battery pack comprising a flow rate uniformizing means for making the flow rate of the battery uniform in the first direction. The flow velocity equalizing means is composed of a plurality of slits installed on the bottom surface or top surface of the internal intake duct, and a baffle plate covering a part of the plurality of slits,
Each of the plurality of slits has a respective opening at the outlet of the internal air intake duct, and is installed so as to partition the bottom surface or the upper surface of the internal air intake duct substantially without being cut along the second direction. ,
The baffle plate is installed so as to be in contact with an upper end surface or a lower end surface of the plurality of slits, and in the first direction, from one side end surface of the internal intake duct substantially perpendicular to the first direction. Out of the side end surfaces of the internal intake duct that are substantially perpendicular to the second direction so as to extend seamlessly to the other side end surface and in the second direction, the refrigerant is supplied to the upstream side of each slit. 2. The battery pack according to claim 1, wherein a gap is provided between the side end surface on the most upstream side.   3. The battery pack according to claim 2, wherein the width of the baffle plate in the second direction is about ½ of the width of the internal intake duct in the same direction.   4. The battery pack according to claim 2, wherein a slit width and an installation interval in the first direction of the plurality of slits are constant. The battery pack according to any one of the preceding claims, wherein the first direction is a direction substantially parallel to a cell stacking direction.

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