JP6281433B2 - Battery pack - Google Patents

Description

  The present invention relates to a battery pack having a battery module.

  As a conventional battery pack having a battery module, for example, a secondary battery device disclosed in Patent Document 1 can be cited. The secondary battery device described in Patent Literature 1 includes a plurality of battery modules, and a battery stack assembly configured by stacking a plurality of battery rows in which a plurality of battery modules are arranged in a row. The battery stack assembly includes a floor plate and a base plate fixed on the floor plate. A battery module is placed on the base plate.

JP 2011-54353 A

  By the way, in a battery pack provided with a plurality of battery modules, the plurality of battery modules are often arranged at the bottom in the case of the battery pack because the center of gravity of the battery pack is set on the bottom side. In this case, a control ECU that controls the battery module is disposed above the battery module, and a junction box that houses a relay, wiring, and the like is disposed above the control ECU. That is, in consideration of the setting of the center of gravity of the battery pack, there are cases in which the vertical arrangement conditions of the battery module, the control ECU, and the junction box cannot be changed. In the battery pack in which the battery module, the monitoring ECU, and the junction box are arranged in order from the bottom to the top, the heat generated from the battery module heats the surrounding air. The heated air moves upward in the vertical direction by convection. At this time, there is a possibility that the control ECU is overheated by supplying heated air to the control ECU. When the control ECU is overheated, problems such as damage to parts with low heat resistance included in the control ECU occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery pack capable of preventing overheating of a control ECU.

In order to solve the above-described problems, the present invention provides a battery pack including a battery module having a plurality of battery cells, a control ECU that controls the battery module, and a junction box to which wiring from the battery module is connected. The control ECU is disposed vertically above the battery module, and the pack case is interposed between the control ECU and the battery module, so that the control ECU covers the downward, have a partition plate for supporting the control ECU, the partition plate is a main body portion for covering the vertical direction below the control ECU, toward vertically upward from both ends of the main body portion extending And a pair of side plate portions facing each other, the pair of side plate portions respectively facing a side wall portion of the pack case, and the side plate portion Air between the serial side wall portion, characterized in that have a possible distribution gap.

According to the present invention, the partition plate provided between the battery module and the control ECU supports the control ECU and is heated from the battery module toward the control ECU in the vertical direction by convection when the battery module generates heat. Block the air. As a result, overheating of the control ECU due to heat generation of the battery module is suppressed.
Further, the side plate portion can easily guide the heated air upward in the vertical direction by convection, and can promote convection inside the battery pack when the battery module generates heat during charging and discharging. Further, the strength of the partition plate that supports the control ECU can be improved.

In the above battery pack, the control ECU is supported by the partition plate via a leg portion provided between the partition plate and the control ECU, and the leg portion includes the partition plate and the control unit. It is good also as a structure which forms a clearance gap between ECU. In this case, since the control ECU is supported by the partition plate via the legs, a gap is formed between the partition plate and the control ECU. The gap between the partition plate and the control ECU prevents heat transfer from the partition plate to the control ECU, and can further prevent overheating of the control ECU.

  Further, the battery pack may include a cover member that surrounds the control ECU. In this case, the cover member can prevent the heat transfer to the control ECU, thereby further preventing the control ECU from overheating.

In the above-described battery pack, the monitoring ECU that monitors the battery module in the vertical direction above the battery module is placed, the monitor ECU may be configured to face the control ECU through the partition plate . In this case, the control ECU is located above the partition plate, and the monitoring ECU is located below the partition plate. Since the control ECU and the monitoring ECU are at a lower temperature than the battery module, the periphery of the partition plate can be set at a lower temperature than the battery module as compared with the case where the monitoring ECU is not provided vertically below the partition plate. ECU overheating can be further prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the battery pack which can prevent overheating of control ECU can be provided.

It is a longitudinal cross-sectional view which shows the battery pack which concerns on embodiment of this invention. It is a perspective view which shows the battery module which concerns on embodiment of this invention. It is an arrow view of the AA line in FIG. (A) is an enlarged vertical sectional view showing an enlarged main part of the battery pack, and (b) is an exploded perspective view showing the control ECU and the partition plate in an exploded manner. It is a principal part enlarged view explaining the convection in the principal part of the battery pack which concerns on embodiment of this invention.

  Hereinafter, a battery pack according to an embodiment of the present invention will be described with reference to the drawings. A battery pack 10 shown in FIG. 1 includes a case 11 as a pack case and a plurality of battery modules 20 accommodated in the case 11. As shown in FIG. 1, the case 11 includes a case body 17 having a rectangular plate-shaped bottom portion 12, rectangular plate-shaped side wall portions 13 to 15 and a top plate portion 16 erected from three sides of the bottom portion 12. doing. The opening 18 surrounded by the bottom 12, the top plate 16, and the side walls 13, 14 in the case body 17 is closed by a lid member (not shown). The vertical direction in FIG. 1 coincides with the vertical direction. The upper side in the vertical direction in FIG. 1 is the top plate 16 side, and the lower side in the vertical direction in FIG. 1 is the bottom 12 side.

  In this embodiment, five battery modules 20 are accommodated in the case 11. The five battery modules 20 are accommodated in the case 11 by being divided into a first battery group G1 in which the three battery modules 20 are stacked and a second battery group G2 in which the two battery modules 20 are stacked. ing. The lowermost battery module 20 of the first battery group G1 and the lower battery module 20 of the second battery group G2 are disposed on the bottom 12 of the case 11. The battery module 20 is disposed on the bottom 12 in order to increase the stability of the battery pack 10 by setting the center of gravity of the battery pack 10 as close to the bottom 12 as possible. In the case 11, a space is formed between the first battery group G1 and the second battery group G2 so as to communicate from the bottom 12 to the top plate 16. Similarly, spaces are formed between the first battery group G1 and the side wall part 14 and between the second battery group G2 and the side wall part 13 so as to communicate from the bottom 12 to the top plate part 16. These spaces function as passages that facilitate the flow of air in the case 11 in addition to spaces for arranging various harnesses.

A space corresponding to one of the battery modules 20 exists above the second battery group G2 in the case 11 in the vertical direction. In this space, a control ECU 21 and a junction box 22 are arranged. The control ECU 21 is arranged vertically above the upper battery module 20 of the second battery group G2, and the control ECU 21 controls each battery module 20. As shown in FIGS. 4A and 4B, the control ECU 21 includes a board portion 23 on which electronic components are mounted, and the board portion 23 is disposed horizontally. In the present embodiment, the control ECU 21 includes a cover member 24 that surrounds the board portion 23. As shown in FIG. 1 and FIG. 4A, the control ECU 21 has a harness 25 provided toward the junction box 22 and a harness 26 connected to the battery module 20 . The harnesses 25 and 26 are wirings that connect from the battery module 20 to the junction box 22. A junction box 22 disposed above the control ECU 21 in the vertical direction is a part that collects electric power of each battery module 20. The junction box 22 is provided with a relay, various wirings, a bus bar and the like (not shown). In the junction box 22 of this embodiment, elements such as relays, various wirings, and bus bars included in the junction box 22 are exposed in the case 11.

  As shown in FIGS. 2 and 3, the battery module 20 includes a plurality of battery cells 30 arranged in parallel and a battery holder 31 that holds the plurality of battery cells 30 arranged in parallel. The battery cell 30 is, for example, a square secondary battery such as a lithium ion secondary battery or a nickel hydride secondary battery. The battery cell 30 has a terminal installation surface 34 provided with a positive electrode terminal 32 and a negative electrode terminal 33, and when the plurality of battery cells 30 are held by the battery holder 31, the terminal installation surface 34 is on the upper side. The battery module 20 in the present embodiment has an odd number of battery cells 30 arranged in parallel, and each battery cell 30 is connected so that the positive electrode terminal 32 and the negative electrode terminal 33 are adjacent to each other. For this reason, the battery cell 30 provided at one end of the battery cell 30 in the juxtaposed direction and the battery cell 30 provided at the other end of the juxtaposed direction have terminals of the same polarity on the side wall 15 side of the case 11. Are provided respectively. The battery cells 30 arranged in parallel are electrically connected by a bus bar 35. In the present embodiment, a plurality of battery cells 30 are connected in series.

  As shown in FIG. 2, the battery module 20 is provided with a positive harness 36 and a negative harness 37 for transmitting the power of the battery module 20. And the harness is connected to either one of the positive electrode terminal 32 and the negative electrode terminal 33 in the battery cell 30 provided in the both ends of the juxtaposition direction, respectively. In this embodiment, the battery module 20 is disposed such that the negative terminals 33 of the battery cells 30 provided at both ends of the battery cells 30 in the juxtaposed direction are provided on the side wall 15 side of the case 11. 32 is provided apart from the side wall 15. A positive electrode harness 36 is connected to the positive electrode terminal 32 of the battery cell 30, and a negative electrode harness 37 is connected to the negative electrode terminal 33 of the battery cell 30. That is, the negative electrode harness 37 is closer to the side wall portion 15 of the case 11 than the positive electrode harness 36. In FIG. 1, the positive electrode harness 36 and the negative electrode harness 37 are not shown.

  The positive harness 36 of the battery module 20 of the first battery group G1 is provided on the battery module 20 side of the second battery group G2. The negative harness 37 of the battery module 20 of the second battery group G2 is provided on the battery module 20 side of the first battery group G1. The negative electrode harness 37 of the battery module 20 of the first battery group G1 and the positive electrode harness 36 of the battery module 20 of the second battery group G2 are provided apart from the side wall part 15 in the thickness direction of the side wall part 15.

  As shown in FIG. 2, end plates 38 are provided at both ends of the battery module 20 in the juxtaposition direction of the battery cells 30. A bracket 39 is provided on the end plate 38. The battery module 20 is fixed to the side wall 15 of the case 11 by attaching the bracket 39 to the side wall 15 of the case 11 via a bolt (not shown). The battery holder 31 supports a mounting plate 40 that is disposed to face the battery cell 30. The mounting plate 40 is provided with a monitoring ECU 41 that monitors each battery module 20. That is, the monitoring ECU 41 is placed above each battery module 20 in the vertical direction.

  As shown in FIGS. 1 and 2, a harness 26 is connected to the monitoring ECU 41. The harness 26 of this embodiment is a collection of a plurality of signal lines. Connectors (not shown) are provided at both ends of each harness 26. One harness 26 is connected to the monitoring ECU 41 provided in the battery module 20 on the bottom 12 side of the first battery group G1. Two harnesses 26 are connected to the battery modules 20 other than the battery module 20 on the bottom 12 side of the first battery group G1. Of the two harnesses 26 of the battery module 20 on the upper side of the second battery group G2, one harness 26 is connected to the control ECU 21, and the remaining harness 26 is monitored by the battery module 20 on the lower side of the second battery group G2. The ECU 41 is connected. In the battery modules 20 other than the battery module 20 on the upper side of the second battery group G2, the monitoring ECUs 41 are connected to each other by the harness 26.

  The monitoring ECU 41 provided in each battery module 20 is provided with a connection portion (not shown) to which the connector of the harness 26 is connected. The monitoring ECU 41 and the harness 26 are connected by connecting the connector to the monitoring ECU 41. In the battery pack 10 of the present embodiment, the state of the battery module 20 such as the temperature of the battery cell 30 and the voltage between the battery cells 30 is monitored by the monitoring ECU 41 provided in each battery module 20. The state of the battery module 20 detected by the monitoring ECU 41 is transmitted to the control ECU 21 via the harness 26. The control ECU 21 controls the battery module 20 based on monitoring information regarding the state of the battery module 20 of the monitoring ECU 41.

  By the way, in the battery pack 10 in this embodiment, as shown in FIG. 4A and FIG. 4B, a partition plate that partitions the control ECU 21 and the battery module 20 of the second battery group G2 up and down. 42 is fixed to the side wall 15 of the case 11. The partition plate 42 is a member that supports the control ECU 21 and performs a heat shielding function that blocks air that is heated by heat generated by the battery module 20 provided below the control ECU 21 and rises due to convection. The partition plate 42 includes a flat plate-shaped main body portion 43 made of iron, and side plate portions 44 that are bent from both ends of the main body portion 43 and extend in a direction perpendicular to the longitudinal direction of the main body portion 43. A bent portion 45 is formed between the main body portion 43 and the side plate portion 44 by bending. One surface of the main body 43 is an upper surface 46 when the partition plate 42 is fixed to the side wall 15 of the case 11, and the other surface of the main body 43 is fixed to the side wall 15 of the case 11. In this state, the lower surface 47 is formed. A plurality of cylindrical leg portions 48 are provided on the upper surface 46, and the leg portions 48 support the lower surface of the substrate portion 23 of the control ECU 21. The board part 23 of the control ECU 21 is fixed to the leg part 48 via a bolt 49. By providing the leg portion 48 between the partition plate 42 and the control ECU 21, a gap T is formed between the control ECU 21 and the partition plate 42. The length in the longitudinal direction of the partition plate 42 is set larger than the length in the longitudinal direction of the control ECU 21.

  The side plate portion 44 of the partition plate 42 is provided with a mounting portion 50 formed by bending. The attachment portion 50 is a portion that contacts the side wall portion 15 of the case 11 and is fixed to the side wall portion 15 by the bolt 51 when the partition plate 42 is fixed to the case 11. In a state where the partition plate 42 is fixed to the side wall 15, the upper surface 46 of the main body 43 is horizontal, and the side plate 44 extends from the main body 43 upward in the vertical direction. The partition plate 42 covers the lower part of the control ECU 21 in the vertical direction. In addition, the strength of the partition plate 42 as a support member that supports the control ECU 21 is ensured by providing the side plate portion 44. In the present embodiment, the monitoring ECU 41 placed above the battery module 20 in the vertical direction faces the control ECU 21 via the partition plate 42.

  Next, the operation of the battery pack 10 of this embodiment will be described. During charging / discharging of the battery pack 10, the battery module 20 and the junction box 22 generate heat. In the sealed case 11, the air that has become hot due to heat generated by the battery module 20 and the junction box 22 moves upward in the case 11, and air convection occurs in the case 11. A broken-line arrow shown in FIG. 5 schematically shows air convection in the case 11.

  The heat generation of the battery module 20 on the upper side of the second battery group G2 heats the surrounding air. Therefore, the air in the space between the battery module 20 and the control ECU 21 is also hot. However, as shown in FIG. 5, the partition plate 42 interposed between the battery module 20 on the upper side of the second battery group G2 and the control ECU 21 blocks the direct flow of high-temperature air to the control ECU 21. The high-temperature air heated above the second battery group G2 in the vertical direction of the battery module 20 circulates upward in the vertical direction from the side plate portion 44 by the convection in the case 11 and moves upward in the vertical direction. Merge with air. The side plate portion 44 guides high-temperature air upward in the vertical direction and prevents the high-temperature air from entering the control ECU 21. For this reason, the temperature of the control ECU 21 does not rise excessively due to the heat generated by the battery module 20. Further, the side plate portion 44 of the partition plate 42 functions to promote the flow of rising air and contributes to the promotion of convection in the case 11.

  In the present embodiment, since the length in the longitudinal direction of the partition plate 42 is set to be sufficiently larger than the length in the longitudinal direction of the control ECU 21, the vertical direction of the battery module 20 positioned above the second battery group G2 is set. The high-temperature air heading from above to the control ECU 21 is reliably blocked. In addition, since a gap T is set between the partition plate 42 and the control ECU 21, a space corresponding to the gap T functions as a heat insulating layer and prevents heat transfer from the partition plate 42 to the control ECU 21. In the battery module 20 located on the upper side of the second battery group G2, the monitoring ECU 41 provided on the top of the mounting plate 40 faces the control ECU 21 via the partition plate. Since the control ECU 21 and the monitoring ECU 41 are cooler than the battery module 20, the periphery of the partition plate 42 is cooler than the battery module 20 as compared with the case where the monitoring ECU 41 is not provided on the lower side in the vertical direction of the partition plate 42. For this reason, it becomes difficult for the temperature of the air above the monitoring ECU 41 to rise in the vertical direction, which contributes to preventing the control ECU 21 from excessively increasing the temperature.

  At the time of charging / discharging, the control ECU 21 is at a lower temperature than the temperature of the junction box 22 and the battery module 20. The low-temperature air around the control ECU 21 is agitated with the air directed upward in the vertical direction by convection, and thereby the temperature of the hot air directed upward in the vertical direction is lowered. The junction box 22 is prevented from overheating because the junction box 22 is exposed to air with a lowered temperature.

According to the battery pack 10 of this embodiment, there exist the following effects.
(1) The partition plate 42 provided between the battery module 20 and the control ECU 21 supports the control ECU 21 and is heated from the battery module 20 toward the control ECU 21 in the vertical direction by convection when the battery module 20 generates heat. Block the air. As a result, overheating of the control ECU 21 due to heat generation of the battery module 20 is suppressed.

(2) The side plate portion 44 provided in the partition plate 42 can easily guide the heated air upward in the vertical direction by convection, and can promote convection inside the battery pack 10 when the battery module 20 generates heat during charging and discharging. it can. The overheating of the junction box 22 can be prevented by promoting the air convection in the case 11. Further, the strength of the partition plate 42 that supports the control ECU 21 by the side plate portion 44 can be improved.

(3) Since the control ECU 21 is supported by the partition plate 42 via the legs 48, a gap T between the partition plate 42 and the control ECU 21 is formed. The space corresponding to the gap T between the partition plate 42 and the control ECU 21 prevents heat transfer from the partition plate 42 to the control ECU 21 as a heat insulating layer, and can further prevent the control ECU 21 from overheating.

(4) The cover member 24 surrounding the control ECU 21 can prevent the heat transfer from the upper part in the vertical direction (junction box 22) of the control ECU 21 to the control ECU 21, and can further reliably prevent the control ECU 21 from overheating. . Further, by providing the cover member 24, it is possible to prevent foreign matter in the case 11 from being deposited on or attached to the substrate portion 23 of the control ECU 21.

(5) The control ECU 21 is positioned above the partition plate 42 in the vertical direction, and the monitoring ECU 41 is positioned below the partition plate 42 in the vertical direction. The control ECU 21 and the monitoring ECU 41 are at a lower temperature than the battery module 20. For this reason, as compared with the case where the monitoring ECU 41 is not provided below the partition plate 42 in the vertical direction, the periphery of the partition plate 42 can be set to a temperature lower than that of the battery module 20, and the control ECU 21 can be further prevented from overheating. .

(6) In the second battery group G2, the battery module 20 is located at the bottom 12 of the case 11, the control ECU 21 is located above the battery module 20 in the vertical direction, and the junction box is located above the control ECU 21 in the vertical direction. 22 is located. For this reason, the center of gravity of the battery pack 10 can be set on the bottom 12 side, and the battery pack 10 having excellent stability that is difficult to fall can be realized.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.

In the above embodiment, the leg portion is provided on the partition plate, and the gap is provided between the partition plate and the control ECU. For example, the leg portion may not be provided, and the upper surface of the partition plate may be brought into contact with the lower surface of the control ECU. Moreover, you may form a leg part in the surface which becomes the partition plate side of control ECU instead of a partition plate. Furthermore, the number and shape of the leg portions are free without any particular limitation.
In the above embodiment, the battery pack including five battery modules is illustrated, but the number of battery modules is not particularly limited. The number of battery modules may be one or more, and even a single battery module may be a battery pack including a junction box .
In the above embodiment, the partition plate is positioned vertically above the battery module, the control ECU is positioned vertically above the partition plate, and the junction box is positioned vertically above the control ECU. It may be diagonally above the control ECU, not just above the control ECU.

DESCRIPTION OF SYMBOLS 10 Battery pack 11 Case 12 Bottom part 15 Side wall part 20 Battery module 21 Control ECU
22 Junction box 23 Substrate part 24 Cover member 25, 26 Harness 30 Battery cell 31 Battery holder 36 Positive electrode harness 37 Negative electrode harness 38 End plate 39 Bracket 40 Mounting plate 41 Monitoring ECU
42 Partition Plate 43 Main Body 44 Side Plate 48 Leg 50 Mounting Portion G1 First Battery Group G2 Second Battery Group T Gap

Claims (4)

A battery module having a plurality of battery cells;
A control ECU for controlling the battery module;
A battery pack provided in a pack case with a junction box to which wiring from the battery module is connected,
The control ECU is arranged vertically above the battery module,
The pack case covers the vertical direction below the control ECU interposed between the battery module and the control ECU, have a partition plate for supporting the control ECU,
The partition plate includes a main body portion that covers a lower portion in the vertical direction of the control ECU, and a pair of side plate portions that extend vertically upward from both ends of the main body portion and face each other.
The pair of side plate portions are respectively opposed to side wall portions of the pack case,
Between the side plate portion and the side wall portion, the battery pack characterized that you have a gap is provided to allow circulation of air. The control ECU is supported by the partition plate via legs provided between the partition plate and the control ECU,
The battery pack according to claim 1 , wherein the leg portion forms a gap between the partition plate and the control ECU . The battery pack according to claim 1, further comprising a cover member surrounding the control ECU . A monitoring ECU that monitors the battery module is placed vertically above the battery module,
The battery pack according to claim 1 , wherein the monitoring ECU faces the control ECU via the partition plate .

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