Waterproof structure of the battery pack

Abstract

To provide a waterproof structure of a battery pack that can prevent the bottom of a battery module from becoming wet by water.SOLUTION: A waterproof structure 100 of a battery pack 200 includes: a waterproof tray 101 in which a battery module included in the battery pack 200 is set; and a waterproof cover 102 for covering the battery pack 200. The waterproof tray 101 includes: a bottom part 111 having an edge part 111a, a battery module being set in the edge part thereof; and a side wall part 112 extending from the edge part 111a. The waterproof cover 102 has an edge part 121. The edge part 121 is located outside the side wall part 112 in a bottom view of the waterproof structure 100 of the battery back 200.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a waterproof structure for a battery pack. [Background technology]

[0002] Conventionally, battery packs mounted on vehicles are known. For example, Japanese Patent Application Laid-Open No. 2020-35711 (Patent Document 1) discloses a battery pack that houses a plurality of battery modules inside a battery case that includes a case body and a cover.

[0003] In this battery pack, a dome-shaped inner cover that bulges upward and has an open lower edge is placed on the upper part of the case body to cover the battery module from above, and the lower edge of the inner cover is positioned below the output terminal of the battery module. More specifically, in this battery module, the battery cells are stacked horizontally. The output terminal is provided on the upper surface of the battery cell. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-35711 A Summary of the Invention [Problem to be solved by the invention]

[0005] When attempting to apply the waterproof structure using the inner cover disclosed in JP 2020-35711 A to a battery module in which battery cells are stacked vertically, the following problems arise.

[0006] In a battery module in which battery cells are stacked vertically, the output terminals of each battery cell are located on the side of the battery module. Therefore, if the battery module becomes wet and water accumulates on the bottom of the case body, the output terminals of the bottommost battery cell will be submerged in water, causing the battery module to short out.

[0007] The present disclosure has been made in consideration of the above problems, and has an object to provide a waterproof structure for a battery pack that can prevent water from getting onto the bottom of a battery module. [Means for solving the problem]

[0008] According to an aspect of the present disclosure, a waterproof structure for a battery pack includes a waterproof tray on which a battery module included in the battery pack is installed, and a waterproof cover that covers the battery pack. The waterproof tray has a first edge and includes a bottom on which the battery module is installed and a sidewall extending from the first edge. The waterproof cover has a second edge. The second edge is located outside the sidewall when viewed from below the waterproof structure for the battery pack.

[0009] With this configuration, even if the waterproof cover is wetted from above, the waterproof cover can prevent water from entering the waterproof tray, and therefore the waterproof structure can prevent water from getting onto the bottom of the battery module.

[0010] Preferably, the battery module includes a plurality of battery cells each having an output terminal, and the battery cells are stacked in a direction from the waterproof tray toward the waterproof cover.

[0011] With this configuration, it is possible to prevent the output terminal of the bottommost battery cell of the plurality of battery cells from becoming wet, thereby preventing a short circuit in the battery module.

[0012] Preferably, the second edge portion has a water return portion extending downward in a side view of the waterproof structure of the battery pack.

[0013] According to this configuration, the water returning portion can guide the water that reaches the second edge of the waterproof cover downward, thereby preventing water from flowing into the waterproof tray from the second edge of the waterproof cover.

[0014] Preferably, a gap is formed between the second edge portion and the side wall portion, the gap functioning as an exhaust port for cooling air that cools the battery module.

[0015] According to this configuration, the gaps ensure a path for cooling air for the battery modules. In addition, because the cooling air is exhausted through the gaps, it is possible to prevent water from flowing into the waterproof tray from outside the waterproof structure due to the cooling air. Effect of the Invention

[0016] According to the present disclosure, it is possible to prevent water from getting onto the bottom of the battery module. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view of an equipment unit mounted on a vehicle. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] 3 is a cross-sectional view taken along line VV in FIG. 2. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 2. [Figure 7] FIG. 2 is a cross-sectional view taken along line VII-VII of FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 2 is a cross-sectional view taken along line IX-IX in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same members are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0019] The battery according to this embodiment is a secondary battery (storage battery). The battery is mounted on a vehicle such as a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0020] Fig. 1 is a perspective view of an equipment unit mounted on a vehicle, Fig. 2 is a top view of the equipment unit, Fig. 3 is a side view of the equipment unit, and Fig. 4 is a bottom view of the equipment unit.

[0021] 1 and 2, the equipment unit 1 includes a waterproof structure 100, a battery pack 200, blowers 300R, 300L, and air intake ducts 400R, 400L. The waterproof structure 100 has a waterproof tray 101 and a waterproof cover 102. Note that the direction indicated by the arrow UPR in Figs. 1 and 2 indicates the ceiling direction (upward) of the vehicle, the direction indicated by the arrow FR indicates the front direction (traveling direction) of the vehicle, and the direction indicated by the arrow LH indicates the left side direction of the vehicle (left side direction).

[0022] As the blower 300R is rotated, air is sucked into the equipment unit 1 from the intake duct 400R as shown by arrow 901. The air is supplied to the battery pack 200 through a chamber. As the blower 300L is rotated, air is sucked into the equipment unit 1 from the intake duct 400L as shown by arrow 902. The air is supplied to the battery pack 200 through a chamber. This cools the battery pack 200.

[0023] The waterproof cover 102 is located above the waterproof tray 101. The waterproof cover 102 covers the battery pack 200 and the blowers 300R, 300L. The waterproof cover 102 protrudes upward and has an open lower edge.

[0024] 3 and 4, the battery pack 200 is placed on a waterproof tray 101. In detail, the battery pack 200 includes a high-voltage device 201 and a battery module 202 (also referred to as a "stack"). In this example, of the high-voltage device 201 and the battery module 202, only the battery module 202 is placed on the waterproof tray 101.

[0025] In the equipment unit 1, the battery pack 200 (more specifically, the battery module 202) is sandwiched from above and below by the waterproof tray 101 and the waterproof cover 102. The waterproof cover 102 covers the high-voltage equipment 201 and the battery module 202 from above, and the waterproof tray 101 covers the battery module 202 from below. The battery module 202 is fixed to the waterproof tray 101 by bolts or the like. The waterproof cover 102 is fixed to the waterproof tray 101 by bolts or the like.

[0026] Specifically, the waterproof tray 101 includes a bottom portion 111 and a side wall portion 112. The bottom portion 111 has an edge portion 111a. In this example, the bottom portion 111 has a rectangular shape as shown in Fig. 4. Therefore, the edge portion 111a becomes the outer periphery of the rectangle.

[0027] The side walls 112 extend from an edge 111a of the bottom 111. The side walls 112 extend upward from the edge 111a. In this example, since the bottom 111 is rectangular, the waterproof tray 101 has four side walls 112.

[0028] The waterproof cover 102 has an edge portion 121. As shown in Fig. 4, the edge portion 121 is located outside the side wall portion 112 when viewed from below the equipment unit 1 (in other words, when viewed from below the waterproof structure 100). In this example, when viewed from below (or from above) the waterproof structure 100, the waterproof cover 102 is larger than the waterproof tray 101. When viewed from below (or from above), the waterproof cover 102 overlaps with the waterproof tray 101 and extends outward beyond the periphery of the waterproof tray 101.

[0029] As described above, the waterproof tray 101 includes the bottom 111 on which the battery module 202 is placed, and the side wall 112 extending from the edge 111a of the bottom 111. The edge 121 of the waterproof cover 102 is located outside the side wall 112 when the waterproof structure 100 is viewed from below.

[0030] Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 2.

[0031] As shown in Fig. 5, the battery pack 200 includes a high-voltage device 201 and a battery module 202. The high-voltage device 201 is located on the front side (FR side) of the battery module 202. As shown in Figs. 5 and 6, the waterproof cover 102 covers the high-voltage device 201 and the battery module 202 from above. The battery module 202 is placed on the waterproof tray 101. More specifically, the battery module 202 is placed on the bottom 111 of the waterproof tray 101. The waterproof tray 101 covers the battery module 202 from below.

[0032] As described above, the waterproof cover 102 includes the edge portion 121. In this example, the edge portion 121 is the outer periphery of the waterproof cover 102. The edge portion 121 has a water return portion 121a that extends downward in a side view of the waterproof structure 100. The water return portion is also called a "return structure."

[0033] The water returning portion 121a is an incline (gradient) given to the portion onto which water is poured. The water returning portion 121a is inclined obliquely downward. More specifically, the water returning portion 121a extends in a direction away from the battery pack 200 as it extends downward. Note that the water returning portion 121a may extend vertically downward.

[0034] The battery module 202 has a plurality of battery cells 221. In the battery module 202, the battery cells 221 are stacked vertically upward from the waterproof tray 101 to the waterproof cover 102. Each battery cell 221 has an output terminal 221a. Since the battery cells 221 are stacked vertically, the output terminals 221a are also lined up vertically.

[0035] The battery module 202 is equipped with restraint plates 251, 252 for restraining the battery cell 221 in the up-down direction. The restraint plate 251 is located above the battery cell 221, and the restraint plate 252 is located below the battery cell 221. The restraint plate 252 contacts the bottom 111 of the waterproof tray 101. The restraint plates 251 and 252 also function as a housing cover for the battery module 202.

[0036] A gap 190 is formed between the waterproof tray 101 and the waterproof cover 102. More specifically, the gap 190 is formed between the side wall portion 112 of the waterproof tray 101 and the edge portion 121 of the waterproof cover 102. As will be described in more detail later, the gap 190 functions as an exhaust port for cooling air that cools the battery module 202.

[0037] Next, the flow of air sucked through the intake ducts 400R and 400L will be described.

[0038] Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 1. For convenience, the waterproof cover 102 is not shown in Fig. 7. As shown in Fig. 7, the equipment unit 1 further includes air intakes 500R and 500L, chambers 250A and 250B, and a separator 600.

[0039] Two chambers 250A and 250B are formed by separating one space by a separator 600. An intake port 500R is connected to the chamber 250A. An intake port 500L is connected to the chamber 250B.

[0040] The air sucked in through the intake duct 400R by the blower 300R flows toward the intake port 500R. As shown by arrow 903, the air is sent from the intake port 500R to the chamber 250A. The air sent to the chamber 250A flows sequentially toward the battery modules 202.

[0041] Similarly, air drawn in from the intake duct 400L by the blower 300L flows toward the intake port 500L. As shown by arrow 904, air is sent from the intake port 500L to the chamber 250B. The air sent to the chamber 250B flows sequentially toward the battery module 202.

[0042] Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 1. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 1. The cross section of Fig. 8 and the cross section of Fig. 9 are separated by a predetermined distance (for example, about 10 cm to 20 cm).

[0043] 8 and 9, air (cooling air) from the chambers 250A, 250B passes through the inside of the battery module 202 as indicated by arrows 905, 906. Specifically, the air flows from the front to the rear through the gaps between the adjacent battery cells 221. The air that has passed through the battery cells 221 heads toward the gaps 190 as indicated by arrow 907. The air is then discharged from the gaps 190 to the outside of the equipment unit 1.

[0044] As described above, a gap 190 is formed between the edge 121 of the waterproof cover 102 and the side wall 112 of the waterproof tray 101. The gap 190 functions as an exhaust port for cooling air that cools the battery module 202. Thus, the waterproof structure 100 has a function of exhausting the air sucked in from the intake ducts 400R, 400L to the outside, in addition to the waterproof function of the battery pack 200.

[0045] The unique configuration of the waterproof structure 100 and the advantages of this configuration will be described below.

[0046] (1) As described above, the waterproof structure 100 includes the waterproof tray 101 on which the battery module 202 included in the battery pack 200 is placed, and the waterproof cover 102 that covers the battery pack 200. The waterproof tray 101 has an edge portion 111a and includes a bottom portion 111 on which the battery module 202 is placed, and a side wall portion 112 extending from the edge portion 111a. The waterproof cover 102 has an edge portion 121. The edge portion 121 is located outside the side wall portion 112 when the waterproof structure 100 is viewed from below.

[0047] According to this configuration, even if the waterproof cover 102 is wetted from above, the waterproof cover 102 can prevent water from entering the waterproof tray 101. Therefore, the waterproof structure 100 can prevent water from getting onto the bottom of the battery module 202.

[0048] Specifically, when viewed from above the waterproof structure 100, the waterproof tray 101 is hidden by the waterproof cover 102. When viewed from below the waterproof structure 100, the waterproof cover 102 is larger than the waterproof tray 101. Therefore, the waterproof structure 100 can prevent the bottom of the battery module 202 from being wetted with water.

[0049] (2) The battery module 202 includes a plurality of battery cells 221 each having an output terminal 221a. The battery cells 221 are stacked in a direction from the waterproof tray 101 toward the waterproof cover 102.

[0050] 5 and 6, when the battery cells 221 are stacked in the direction from the waterproof tray 101 toward the waterproof cover 102 (vertically upward), the battery cells 221 are lined up in that direction. In other words, the output terminal 221a of the bottommost battery cell 221 is located near the waterproof tray 101.

[0051] According to the waterproof structure 100, even if the stacking direction of the battery modules 202 is vertical, it is possible to prevent the output terminal 221a of the bottommost battery cell 221 among the multiple battery cells 221 from becoming wet with water. This makes it possible to prevent a short circuit of the battery module 202.

[0052] (3) The edge 121 of the waterproof cover 102 has a water-reflecting portion 121a that extends downward when the waterproof structure 100 is viewed from the side.

[0053] According to this configuration, the water returning portion 121a can guide the water that has reached the edge portion 121 of the waterproof cover 102 downward. 1 This can prevent water from entering the tank.

[0054] (4) A gap 190 is formed between the edge 121 of the waterproof cover 102 and the side wall 112 of the waterproof tray 101. The gap 190 functions as an exhaust port for the cooling air that cools the battery module 202.

[0055] According to this configuration, the gap 190 can secure a path for cooling air for the battery module 202. In addition, since the cooling air is exhausted from the gap 190, it is possible to prevent water from flowing into the waterproof tray 101 from the outside of the waterproof structure 100 due to the cooling air.

[0056] (5) The waterproof structure 100 is composed of a waterproof tray 101 and a waterproof cover 102. Therefore, according to the waterproof structure 100, the number of parts used for waterproofing the battery pack 200 can be reduced.

[0057] (6) Waterproof Cover 102 is required to have a size that covers at least the battery pack 200, and Waterproof Tray 101 The size of the waterproof structure 100 may be reduced so long as the battery module 202 can be installed therein.

[0058] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. [Explanation of symbols]

[0059] 1 equipment unit, 100 waterproof structure, 101 waterproof tray, 102 waterproof cover, 111 bottom, 111a, 121 edge, 112 side wall, 121a water return section, 190 gap, 200 battery pack, 201 high voltage equipment, 202 battery module, 221 battery cell, 221a output terminal, 250A, 250B chamber, 251, 252 restraining plate, 300L, 300R blower, 400L, 400R intake duct, 500L, 500R intake port, 600 separator.

Claims

1. a waterproof tray on which a battery module included in the battery pack is placed; a waterproof cover for covering the battery pack; the waterproof tray has a first edge and includes a bottom on which the battery module is placed and a sidewall extending from the first edge; The waterproof cover has a second edge, the second edge portion is located outside the side wall portion in a bottom view of the waterproof structure of the battery pack, A gap is formed between the second edge portion and the side wall portion, The gap functions as an exhaust port for cooling air that cools the battery module.

2. the battery module includes a plurality of battery cells each having an output terminal; The waterproof structure of a battery pack according to claim 1 , wherein the battery cells are stacked in a direction from the waterproof tray toward the waterproof cover.

3. 3. The waterproof structure for a battery pack according to claim 1, wherein the second edge portion has a water return portion extending downward in a side view of the waterproof structure for a battery pack.

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