JP7110927B2 - Cooling system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling device that cools a storage battery mounted on a vehicle by heat exchange with coolant.

Conventionally, this type of cooling device includes a cooling plate that is installed so as to face the bottom surface of a secondary battery cell mounted in an electric vehicle such as a hybrid vehicle or an electric vehicle, and cools the secondary battery cell from the bottom surface. A proposal has been made to provide such a device (see, for example, Patent Document 1). Inside the cooling plate, there is a cooling liquid pipe through which the cooling liquid passes, and the cooling device cools the secondary battery cells by heat exchange with the cooling liquid.

JP 2013-125617 A

In the cooling system described above, if an impact is applied to the floor surface of the vehicle due to interference with the road surface or riding on a foreign object while driving, and the impact is transmitted to the cooling plate and the cooling plate is damaged, depending on the location of the damaged coolant pipe, , the coolant in the coolant pipe may splash on the secondary battery cells.

In the cooling device of the present invention, a storage battery mounted on a vehicle is cooled by heat exchange with a cooling liquid flowing through a cooling plate. A main object of the present invention is to provide a cooling device capable of appropriately preventing

The cooling device of the present invention employs the following means in order to achieve the above main object.

The cooling device of the present invention is
A cooling device that cools a storage battery mounted on a vehicle by heat exchange with a coolant,
A cooling plate disposed below the storage battery and constituting at least part of a storage battery case and having a cooling liquid pipe through which the cooling liquid flows,
A bottom surface portion of the cooling liquid pipe opposite to the storage battery has a groove extending along the extension direction of the cooling liquid pipe,
This is the gist of it.

The cooling device of the present invention includes a cooling plate that is arranged on the bottom side of the storage battery, constitutes at least a part of the storage battery case, and has a cooling liquid pipe through which the cooling liquid flows. The bottom surface portion of the cooling liquid pipe on the side opposite to the storage battery has a groove extending along the extending direction of the cooling liquid pipe. As a result, when an impact is applied to the floor of the vehicle and is transmitted to the cooling plate, the stress can be concentrated on the grooves formed on the bottom of the coolant pipe, giving priority to the bottom. can be irrevocably damaged. As a result, even if the cooling plate is damaged, it is possible to appropriately prevent the coolant from splashing onto the storage battery.

1 is a schematic diagram of an electric vehicle 1 equipped with a cooling device 20 as one embodiment of the present invention; FIG. 3 is an exploded perspective view of battery unit 10 including cooling plate 30 of cooling device 20. FIG. 3 is a cross-sectional view of battery unit 10 including cooling plate 30. FIG. 3 is a partial cross-sectional view of cooling liquid pipes 35 of the cooling plate 30. FIG. FIG. 4 is an explanatory diagram showing how a bottom wall portion 38 is damaged when an impact is applied to the coolant pipe 35 from below; FIG. 11 is a partial cross-sectional view of a coolant pipe 135 of a cooling plate of a modified example;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a schematic diagram of an electric vehicle 1 equipped with a cooling device 20 as an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a battery unit 10 including a cooling plate 30 of the cooling device 20. FIG. 3 is a cross-sectional view of battery unit 10 including cooling plate 30 .

As shown in FIG. 1, the electric vehicle 1 includes a battery unit 10 installed under the floor of the vehicle, and a motor (not shown) that uses electric power from the battery unit 10 to output power to a drive shaft connected to drive wheels. , and a cooling device 20 of this embodiment for cooling the battery unit 10 . The electric vehicle 1 may be an electric vehicle that includes only a motor as a power source for running, or a hybrid vehicle that includes an engine in addition to a motor as a power source for running. Also, the electric vehicle 1 may be a fuel cell vehicle that includes a fuel cell in addition to the battery unit 10 .

The battery unit 10 includes, as shown in FIG. 2, a plurality of battery packs 11 each including a plurality of battery cells 12 (for example, lithium ion battery cells), and a battery case housing the plurality of battery packs 11 . The battery pack 11 is constructed by restraining a plurality of stacked battery cells 12 in the stacking direction using restraints 13 . The battery case has sidewalls 15 covering the side surfaces of the plurality of battery packs 11, and a bottom wall covering the bottom surface of the battery packs 11 via the heat conductive sheet 40. The battery case is also provided with a cooling device for cooling the battery packs 11 from the bottom surface. and a cooling plate 30 . In addition, the side wall 15 is formed by, for example, extrusion molding of an aluminum alloy. The cooling plate 30 is fixed to the side wall 15 with bolts or the like. The thermally conductive sheet 40 is configured as a sheet body having excellent thermal conductivity made of acrylic resin, silicone resin, or the like, for example.

The cooling device 20 of the embodiment cools each battery cell 12 from the bottom side by heat exchange with a coolant (for example, water or LLC) flowing inside the cooling plate 30 . In this embodiment, as shown in FIG. 1, the cooling device 20 is a liquid cooling system in which a pump 22, a radiator 24, and a cooling plate 30 are provided in a cooling liquid circulation path 21 filled with cooling liquid. Configured as a device. The cooling plate 30 cools each battery cell 12 by heat exchange with the cooling liquid flowing through the cooling plate 30 when the cooling liquid in the cooling liquid circulation path 21 is circulated by driving the pump 22 .

The cooling plate 30 has, as shown in FIG. The plate body 31 is formed, for example, by extrusion molding of an aluminum alloy. The plate body 31 has a plurality of cooling liquid lines extending in the longitudinal direction of the battery pack 11 (the stacking direction of the battery cells 12), one end communicating with the inflow pipe 32, and the other end communicating with the outflow pipe 33. It has piping 35 .

As shown in FIG. 4, each cooling liquid pipe 35 has a top wall portion 36 and a bottom wall portion 38 of approximately the same thickness which are provided in parallel with each other at a vertical interval, and a top wall portion 36 and a bottom wall portion 38. and a partition wall portion 37 that divides the space between the The upper wall portion 36, the bottom wall portion 38 and the partition wall portion 37 are integrally formed by, for example, extrusion molding of an aluminum alloy. As a result, a plurality of coolant flow paths 39 extending parallel to the longitudinal direction of the battery pack 11 (the stacking direction of the battery cells 12 ) are formed in each coolant pipe 35 . At both corners of the bottom surface of each cooling liquid channel 39 , that is, the upper surface of the bottom wall portion 38 , grooves 38 a extending along the extending direction of the cooling liquid channel 39 are formed. Therefore, the portion of the bottom wall portion 38 where the groove 38a is formed is a thin portion.

Now, let us consider the case where the floor surface of the vehicle is subjected to an impact due to interference with the road surface, running over a foreign object, or the like while the vehicle is running. When the impact applied to the floor surface is transmitted to the bottom wall portion 38 of the coolant pipe 35 (cooling plate 30) and the bottom wall portion 38 is deformed as indicated by the broken line in FIG. , in the figure, the stress concentrates on the grooves 38a on the left and right ends. Then, the bottom wall portion 38 of the cooling liquid pipe 35 is broken at the portion of the groove 38a, and the cooling liquid flowing through the cooling liquid flow path 39 leaks downward from the vehicle. As a result, breakage of the upper wall portion 36 of the coolant pipe 35 can be suppressed, the coolant can be prevented from splashing onto the battery cell 12, and the occurrence of electric leakage or the like in the battery cell 12 can be prevented. . In the electric vehicle 1 of the embodiment, as shown in FIG. 3, the impact absorbing member 5 is arranged below the cooling plate 30, and when an impact is applied from under the floor of the vehicle, the impact absorbing member 5 By deforming, the shock is absorbed. Therefore, even if an impact is applied from under the floor of the vehicle, the impact is normally absorbed by the impact absorbing member 5 and is not transmitted to the cooling plate 30. may be transmitted to the cooling plate 30 without being completely absorbed by the shock absorbing member 5 . In this embodiment, even if an impact is transmitted to the cooling plate 30, the bottom wall portion 38 of the coolant pipe 35 is preferentially destroyed, thereby preventing damage to the top wall portion 36 of the coolant pipe 35. can be suppressed.

The cooling device 20 of the present embodiment described above includes the cooling plate 30 that is arranged on the bottom surface side of the battery cell 12 and constitutes a part of the battery case, and that has a cooling liquid pipe 35 inside which the cooling liquid flows. . A bottom wall portion 38 of the coolant pipe 35 opposite to the battery cell 12 has a groove 38a extending along the extension direction of the coolant pipe 35 . As a result, when an impact applied to the floor surface of the vehicle is transmitted to the cooling plate 30, the stress is concentrated on the recessed line 38a of the bottom wall portion 38 of the coolant pipe 35, so the bottom wall portion 38 is given priority. can be damaged. As a result, even if the cooling plate 30 is damaged, it is possible to appropriately prevent the coolant from splashing onto the battery cells 12 .

In the embodiment, grooves 38 a are formed at both corners of the bottom surface (upper surface of bottom wall portion 38 ) of all coolant flow paths 39 of coolant pipe 35 . However, the bottom surface of some of the cooling liquid flow paths 39 (the upper surface of the bottom wall portion 38), for example, only the bottom surfaces of the two cooling liquid flow paths 39 at both ends in the width direction of the plurality of cooling liquid flow paths 39 are recessed. It is good also as what forms a line|row.

In the embodiment, the upper wall portion 36 and the bottom wall portion 38 of the coolant pipe 35 are formed with substantially the same thickness. However, as shown in the coolant pipe 135 of the modified example in FIG. As a result, the upper wall portion 136 of the cooling liquid pipe 135 can be made more difficult to break, and the cooling liquid can be more reliably prevented from splashing onto the battery cells 12 when the cooling plate breaks.

In the embodiment, the upper wall portion 36, the bottom wall portion 38 and the partition wall portion 37 of the coolant pipe 35 are integrally formed by extrusion molding. However, the upper wall portion 36, the bottom wall portion 38, and the partition wall portion 37 may be partially formed separately and joined using a joining method such as brazing.

In the embodiment, the cooling device 20 is configured as a liquid type cooling device in which a pump 22 , a radiator 24 and a cooling plate 30 are provided in a cooling liquid circulation path 21 . However, the cooling device is provided with a compressor, a condenser, an expansion valve, and an evaporator in a circulation path filled with a refrigerant, and cools the battery cells using the cooling liquid cooled by heat exchange with the evaporator. It may be configured as a refrigeration cycle device.

The correspondence relationship between the main elements of the embodiment and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the plurality of battery cells 12 correspond to the "storage battery", the cooling plate 30 corresponds to the "cooling plate", the coolant pipe 35 corresponds to the "coolant pipe", and the grooved line 38a corresponds to the "grooved line". Equivalent to

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the form for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the cooling device manufacturing industry.

Reference Signs List 1 electric vehicle 5 impact absorbing member 10 battery unit 11 battery pack 12 battery cell 13 restraint 15 side wall 16 fastening member 20 cooling device 21 coolant circulation path 22 pump 24 radiator 30 cooling plate 31 plate main body 32 inflow pipe 33 outflow pipe 35,135 coolant pipe 36,136 upper wall portion 37 partition wall portion 38 bottom wall portion 38a groove 39 coolant channel 40 Thermally conductive sheet.

Claims (1)

A cooling device that cools a storage battery mounted on a vehicle by heat exchange with a coolant,
A cooling plate disposed below the storage battery and constituting at least part of a storage battery case and having a cooling liquid pipe through which the cooling liquid flows,
The bottom surface of the cooling liquid pipe on the side opposite to the storage battery has a groove extending along the extending direction of the cooling liquid pipe ,
The cooling liquid pipe extends in parallel by a top wall portion and a bottom wall portion which are vertically spaced apart from each other, and a partition wall portion which partitions the space between the top wall portion and the bottom wall portion into a plurality of sections. having a plurality of coolant channels,
The grooves are formed at both corners of the upper surface of the bottom wall portion in each of the plurality of coolant flow paths,
Cooling system.

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