JP6520068B2 - Battery pack cooling system - Google Patents

Description

  The present invention relates to a battery pack cooling device.

  A high voltage and large capacity battery pack, which is a power supply unit of an electric motor, is mounted on a vehicle having an electric motor as an electric drive source or a vehicle having both an electric motor and an internal combustion engine. The battery pack has a plurality of cells arranged adjacent to one another, and each cell generates heat due to charging and discharging. The vehicle is equipped with a cooling device that suppresses the temperature rise of the battery pack by cooling each cell. As a cooling device, there are an air cooling type and a water cooling type. As a water cooling type cooling device, a cooling passage in which a cooling fluid flows is disposed between the cells, and a pump serving as a driving source is operated to circulate the cooling fluid in the cooling passage (for example, Patent Document 1) ).

JP, 2013-62207, A

In the case of a water cooling type cooling device, the heat of the battery pack (cell) is transmitted to the cooling water through the cooling passage, but when the cooling water is at a temperature higher than the boiling point and is vaporized, bubbles are generated and the inside of the cooling passage is generated. The pressure in the pipe increases, and an excessive pressure resistance is required for the cooling path. Further, even if the pump becomes unusable, it is desirable from the viewpoint of safety to suppress the increase in the pressure in the cooling passage.
An object of the present invention is to suppress an increase in pressure in a cooling passage of a cooling device.

In order to achieve the above object, in the battery pack cooling device according to the present invention, a cooling passage in which the cooling water flows, a pump for circulating the cooling water in the cooling passage, a cooling passage, and a plurality of cells in side by side arranged a battery pack, a ramp which is inclined upward toward the top from the bottom of each other in contact with the respective surfaces facing each other, and the cells of the cell between adjacent cells, the pressure in the cold却路a valve for discharging outside the cooling passage, have a cooling puddle portion communicating with the cooling passage, the cooling passage includes a first path for supplying cooling water to the inclined path through the lower end and communicating ramp, inclined A second channel is provided in communication with the upper end of the channel to recover the cooling water passing through the ramp, and the cooling water reservoir portion is between the first channel and the second channel on the upstream side of the first channel. Are connected to the first path and the second path and Is disposed on the upper side than the substantially central portion located between the bottom and top of the cell, the valve is characterized that you have been placed on the upper surface of the second path or cooling puddle unit.

  According to the present invention, the inside is in communication with the cooling path through which the cooling water flows, and in the battery pack in which the plurality of cells are arranged side by side, the mutually facing surfaces of the cells are in contact with each other. The pump has a stop because it has a ramp that inclines from the bottom to the top of the cell and a cooling path that communicates with the upper side of the ramp and that discharges the pressure in the cooling path out of the cooling path. Even in this case, air bubbles generated in the cooling passage rise by natural convection of the cooling water generated along the inclined passage and are discharged from the valve, so that the increase in pressure in the cooling passage can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the vehicle provided with the cooling device of the battery pack which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The top view explaining the schematic structure of the cooling device of the battery pack which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The side view explaining the principal part structure of the 1st Embodiment of this invention. The enlarged view explaining the composition and arrangement of a ramp. The enlarged view which planarly viewed the structure and arrangement | positioning of a ramp. The enlarged view which carried out the side view of the structure and arrangement | positioning of a ramp. The enlarged view explaining the composition and arrangement of a slope provided with the fin which becomes the important section of a 2nd embodiment of the present invention. The enlarged view which carried out the side view of the structure and arrangement | positioning of the inclined path provided with the fin which becomes the principal part of the 2nd Embodiment of this invention. The schematic block diagram which shows the modification of the cooling device of the battery pack which changed arrangement | positioning of the valve. The schematic block diagram which shows the modification of the cooling device of the battery pack connected with another cooling device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, a modification, etc., the same numerals are given to the member which has the same member and the same function, and the overlapping explanation is omitted.
In FIG. 1, a vehicle indicated by reference numeral 1 supplies electric power from a battery pack 2 serving as a power supply unit to an electric motor 4 serving as a drive unit via an inverter 3, and rotates the electric motor 4 to rotationally drive a wheel 5. To drive. The vehicle 1 may be either an electric vehicle equipped with the electric motor 4 or a hybrid type vehicle equipped with both the electric motor 4 and the internal combustion engine. In the present embodiment, the vehicle 1 rotationally drives the rear wheel 5B (wheel 5) to be a driving wheel by the electric motor 4, but may be a vehicle rotationally driving the front wheel 5A (wheel 5).

  The battery pack 2 is disposed on a shielding plate 8 disposed below a floor 7 provided in a cabin 6 of the vehicle 1. As shown in FIG. 2, the battery pack 2 has a plurality of cells 20 arranged in the vehicle width direction indicated by the arrow Y inside the casing 2A as one module, and the vehicle width direction Y and the arrow It is configured as a power supply unit including a plurality of modules arranged side by side in the vehicle front-rear direction indicated by X. The battery pack 2 is configured to be able to output a high voltage by connecting the same terminals of the positive terminal and the negative terminal of each module in series. Each cell is a secondary battery such as a lithium ion battery, for example, and generates heat during charging and discharging. When this heat generation ends the allowable limit of the cell 20, it may generate heat to a high temperature, for example, 300 degrees or more.

First Embodiment
The vehicle 1 is provided with a cooling device 10 in order to maintain the temperature of such a battery pack 2 (cell 20) in an appropriate range. As shown in FIGS. 2 and 3, the cooling device 10 is provided in a cooling passage 12 through which the cooling water 11 flows, a pump 13 for circulating the cooling water 11 in the cooling passage 12, and the cooling passage 12 A valve 14 for discharging the pressure in the passage 13 out of the cooling passage and a cooling water reservoir 15 communicating with the cooling passage 12 are provided. The cooling path 12 has a ramp 121 disposed between adjacent cells in the battery pack 2 in which the plurality of cells 20 are arranged side by side. Since the configuration of the ramp 121 disposed between the cells is the same, the configurations of the ramp 121 and the cooling passage 12 corresponding to one module will be described below.

  The cooling path 12 is formed of a metal and a square hollow pipe member. For this reason, the surface of the pipe member is subjected to insulation treatment. The cooling path 12 may not be a metal pipe member but may be a resin pipe member. The cooling path 12 includes a supply path 122 which is a first path for supplying the cooling water 11 to the slope 121, and a recovery path 123 which is a second path for recovering the cooling water which has passed the slope 121. ing. The supply path 122 is disposed below the lower portion 20c of the cell 20 as shown in FIGS. 3, 4 and 6, and the recovery path 123 is below the upper portion 20d of the cell 20 and the central portion 20e of the cell 20. It is located higher than that. The supply path 122 is connected to the lower end 121 c which is one end of the inclined path 121, and the recovery path 123 is connected to the upper end 121 d which is the other end of the inclined path 121. That is, the cooling device 10 includes the supply path 122 which is a first path communicating with the lower end 121c of the inclined path 121, and the recovery path 123 which is a second path communicating with the upper end 121d of the inclined path 121. .

  As shown to FIG. 2, FIG. 3, the pump 13 is a fluid pump, Comprising: It arrange | positions in the supply path 122 in the outer side of casing 2A (battery pack 2). The cooling device 10 includes a temperature sensor 17 as a temperature detection unit that detects the temperature of the cooling water 11 in the cooling passage 12. The temperature sensor 17 is connected to the control unit 60 via a signal line. The control unit 60 is a computer, and receives temperature information detected by the temperature sensor 17. The control unit 60 controls the drive of the pump 17 based on the temperature information from the temperature sensor 17. The control unit 60 drives the pump 13 so that the cooling water 11 circulates in the cooling passage 12 when the temperature of the cooling water 11 in the cooling passage 12 becomes equal to or higher than the predetermined temperature. The driving of the pump 13 is stopped.

As shown in FIG. 4 and FIG. 5, the inclined path 121 penetrates the case 70 of the module having the plurality of cells 20 inside, ascends from the lower side to the upper side, and penetrates the outside of the case 70. The lower end 121c and the upper end 121d are protruded. As shown in FIG. 5, the opposing surfaces 121a and 121b of the inclined path 121 with the cells 20 are bonded to the surfaces 20a and 20b of the cells 20 facing each other by a highly thermally conductive adhesive. It is in contact (close contact). The ramps 121 are inclined upward from the lower portion 20c to the upper portion 20d of each cell 20 so as to pass through the central portion 20e located between the lower portion 20c and the upper portion 20d of each cell 20, as shown in FIG. It is arranged between each cell 20.
The cooling water reservoir portion 15 is constituted by a tank having a capacity larger than at least the total volume of the cooling water 11 flowing in the cooling passage 12, and the cooling water 11 is stored. The cooling water reservoir 15 is disposed between the supply passage 122 and the recovery passage 123 on the upstream side of the pump 13 and connected to the supply passage 122 and the recovery passage 123.

In the cooling device 10 having such a configuration, as shown in FIG. 3, when the temperature of the cooling water 11 reaches a predetermined temperature or higher, the pump 13 is driven to supply the cooling water 11 to the discharge port side of the pump 13. It flows from 122 to the recovery passage 123 connected to the suction port of the pump 13 via the cooling water reservoir 15 through the inclined passage 121 and circulates in the cooling passage 12.
The heat generated in the cells 20 is transferred from the surfaces 20a and 20b of the cells 20 to the cooling water 11 through the facing surfaces 121a and 121b of the inclined path 121, as shown in FIGS. As a result, the cells 20 are cooled, and as a result, the battery pack 2 is cooled, and the temperature rise is suppressed. For this reason, the temperature of the cooling water 11 in the recovery path 123 is higher than the temperature of the cooling water 11 in the supply path 122, and natural convection occurs in the cooling path 12 due to the temperature difference between the two. The cooling water 11 is heated by the heat from the cell 20 and may exceed the boiling point depending on the calorific value. When the cooling water 11 exceeds the boiling point, it is vaporized and turns into steam, and bubbles 16 are generated in the cooling water 11.
The valve 14 is a relief valve (pressure regulating valve) that opens when the pressure reaches a predetermined pressure, and is a recovery passage 123 (cooling passage 12) that communicates with the inclined upper side of the inclined passage 121 outside the casing 2A (battery pack 2). ) Is placed. The valve 14 is set to open when the pressure in the cooling passage 12 reaches a predetermined pressure of atmospheric pressure + α. The valve 14 is provided on the upper surface 123 a of the recovery passage 123 which is the highest position of the cooling passage 12.

  The air bubbles 16 generated in the cooling passage 12 are accumulated on the upper surface 123 a side of the collecting passage 123 through the inclined passage 121 due to the difference in height between the supply passage 122 and the collecting passage 123 and the temperature difference of the cooling water 11. When the pressure in the pipe reaches a predetermined pressure, the valve 14 discharges the inside of the cooling passage 12 (recovery passage 123). At this time, since the valve 14 is disposed outside the casing 2A of the battery pack 2, the air bubbles 16 (vapor) discharged from the valve 14 do not accumulate in the casing 2A. Therefore, it is possible to prevent the inside of the battery pack 2 from being heated by the air bubbles 16 (steam) discharged from the valve 14.

According to the configuration of the cooling device 10 according to the present embodiment, an increase in pressure in the cooling passage 12 of the cooling device 10 can be suppressed, and excessive pressure resistance against the cooling passage 12 and the pump 13 can be obtained. You do not have to set it. Further, the supply path 122 for the cooling water 11 and the recovery path 123 for the cooling water 11 are in a positional relationship in which the recovery path 123 is located above the vehicle with respect to the supply path 122. The lower end 121 a of the inclined path 121 is connected to the supply path 122, and the upper end 121 b is connected to the recovery path 123. Therefore, even when the pump 13 is not driven due to a failure or the like, an excessive pressure is discharged from the recovery passage 123 through the valve 14 when the pressure in the cooling passage 12 becomes a predetermined pressure. When an excessive pressure is discharged from the valve 14, a pressure difference further occurs in the cooling passage 12 on the side of the supply passage 122 and the collecting passage 123, and natural convection occurs more strongly in the cooling passage 12. Therefore, the air bubbles 16 generated in the supply passage 12 are conveyed to the recovery passage 123 by natural convection of the cooling water 11 and are discharged from the valve 14. Therefore, even when the pump 13 does not operate, the increase in the pressure in the cooling passage 12 can be suppressed more stably.
Since the slopes 121 are disposed between the cells 20 and 20 facing each other, they also function as inter-cell spacers. Therefore, even when one cell 20 generates heat excessively, temperature rise of the other cell 20 adjacent to it can be suppressed. Since the inclined path 121 is installed so as to pass through the central portion 20e of each adjacent cell 20, the cooling water 11 is guided to a portion where the heat generation temperature of the cell 20 is high, and a large amount of heat is transmitted to the cooling water 11, Cooling efficiency can be improved.

  In the present embodiment, the cooling water reservoir portion 15 is disposed on the vehicle upper side with respect to the substantially central portion 20e located between the lower portion 20c and the upper portion 20d of the cell 20. Therefore, when the pressure in the pipe reaches a predetermined pressure while the pump 13 is stopped, air bubbles 16 and steam are discharged from the valve 14 to the outside of the cooling passage 12 and the amount of the cooling water 11 in the cooling passage 12 decreases. The cooling water 11 in the water reservoir 15 falls into the supply passage 122 by its own weight. Therefore, even while the pump 13 is stopped, the cooling water 11 can be supplied to the supply path 122 side, so that the cooling failure of each cell 20 due to the lack of the cooling water can be suppressed. As a result, the pressure in the pipe increases. It leads to curbing.

Second Embodiment
The cooling device 10A according to the present embodiment, as shown in FIG. 7, is connected to the ramps 121 and the surfaces 20a and 20b of the cells 20, and the facing surfaces 121a and 121b of the ramps 121 shown by broken lines and the cells It has the fin 127 arrange | positioned in the site | part different from the contact area | region Z with each surface 20a, 20b. As shown in FIG. 8, the fins 127 are formed of a metal member having a U-shaped cross section. As shown in FIG. 7, the fins 127 are adhered and bonded to the upper surface 121e and the respective surfaces 20a and 20b of the inclined path 121 and the lower surface 121f and the respective surfaces 20a and 20b of the inclined path 121 respectively. It is done.
As described above, when the fins 127 are provided, the heat receiving area from each cell 20 to the slope 121 is larger than that in the configuration without the fins 127. Therefore, heat can be efficiently transmitted to the cooling water 11 in the inclined path 121, and the temperature rise of the cell 20 can be more stably suppressed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and the present invention described in the appended claims unless otherwise specified in the above description. Various modifications and changes are possible within the scope of the present invention.
For example, in the first and second embodiments, the valve 14 is provided on the upper surface 123a of the recovery passage 123 disposed at the top of the cooling passage 12, but as shown in FIG. Alternatively, the space portion 28 may be formed to project above the upper surface 123a and the valve 14 may be provided on the upper portion 28a of the space portion 28. In this case, the air bubbles 16 in the cooling passage 12 are carried into the cooling water reservoir 15 by the flow of the cooling water 11 and accumulated in the space 28, so that the accumulated air bubbles 16 are discharged from the valve 14. An increase in pressure in the pipe can be suppressed.

As shown in FIG. 10, the vehicle 1 is provided with a water cooling drive cooling device 100 for cooling a drive system 104 such as the inverter 3 or the electric motor 4 separately from the cooling device 10 of the battery pack 2 is there. The drive cooling device 100 includes a supply path 101 for supplying cooling water to the drive system 104, a recovery path 102 for recovering the cooling water heat-exchanged by the drive system 104, a supply path 101 for the cooling water, the drive system 104, and recovery. A drive cooling pump 103 is provided to circulate and move in the passage 102. When such a drive cooling device 100 is provided, cooling water on the drive cooling device 100 side is cooled by the cooling device 10 of the battery pack 2 by connecting the supply passage 101 and the recovery passage 102 to the cooling water reservoir portion 15. It is preferable because it can be used as water and can compensate for the shortage of cooling water on the cooling device 10 side.
The effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects by the present invention are limited to those described in the embodiments of the present invention. It is not a thing.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle 2, 2 ... Battery pack, 4 ... Drive part, 10, 10A ... Cooling device, 11 ... Cooling water, 12 ... Cooling path, 13 ... Pump, 14 ································································· Valves 15 ··· Cooling water reservoir, 20 ··· Multiple cells, 20 a, 20 b ··· Surface of cells, 20 c ··· Lower part of cells, 20 d ··· Upper part of cells · Substantially central part of the cell, 121 · · · · · · · · · · · · · · · · · · · · · · · · · approximately the center of the cell, 121 · · · · · · · · · · · the upper end of the ramp (the upper end of the ramp) ... Second path, Z ... Contact area

Claims (3)

A cooling passage through which cooling water flows,
A pump for circulating cooling water in the cooling passage;
The battery pack is in communication with the cooling path, and in the battery pack in which a plurality of cells are arranged side by side, contacts adjacent surfaces of the cells between adjacent cells and inclines upward from the bottom to the top of the cells And the ramp,
A valve for discharging the pressure before Symbol cooling passage out of the cooling passage,
Have a cooling puddle portion communicating with the cooling passage,
The cooling passage is in communication with the lower end of the inclined passage and supplies the first passage for supplying cooling water to the inclined passage, and the upper end of the inclined passage is communicated with the upper end of the inclined passage to recover the cooling water passing through the inclined passage. Have a second path to
The cooling water reservoir portion is disposed connected to the first path and the second path between the first path and the second path on the upstream side of the first path. And disposed above the substantially central portion located between the lower and upper portions of the cell,
The valve, the second path or the cooling puddle portion cooling unit of a battery pack that is disposed on the upper surface of the. In the battery pack cooling device according to claim 1,
The valve includes a cooling device for a battery pack that is disposed outside the side of the battery pack. In the battery pack cooling device according to claim 1 or 2,
The ramp and are connected to each surface of the cell, the ramp and the cooling device of the battery pack that having a fin located in different sites and the contact area between the surface of the cell.

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