Battery module

Abstract

Provided is a battery module capable of accurately detecting the entry of a liquid. 【Solution means】The battery module 1 includes an exterior case 2, a battery assembly 3 housed in the exterior case 2, an inlet 27 provided on a first end wall 21 of the exterior case 2, a fan 5 attached to the inner surface of the first end wall 21 and blowing air sucked through the inlet 27 into the interior of the exterior case 2, a vertical wall portion 6 having a facing surface 61 facing the fan 5 and a guide rib 62 protruding from the lower portion of the facing surface 61 toward the fan 5, and a liquid leakage sensor 7 extending along the facing surface 61 and at least a part of which is arranged along the guide rib 62.

Description

Technical Field

[0001] The present invention relates to a battery module.

Background Art

[0002] Patent Document 1 discloses a battery module in which a plurality of battery cells are housed in a case. The battery module has a fan to air-cool heat-generating components such as battery cells. The case is provided with an inlet and an outlet through which cooling air passes, and the inlet and the outlet are constituted by a plurality of through-holes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As an example of the usage form of a battery module, one or more battery modules may be arranged in alignment on a shelf together with a water-cooled electronic device. If the coolant leaks by any chance, there is a risk that the coolant will enter the case of the battery module through the inlet or outlet for cooling air. There is also a risk of liquid entry in other usage forms.

[0005] An object of the present invention is to provide a battery module capable of accurately detecting the entry of liquid.

Means for Solving the Problems

[0006] One aspect of the present invention provides a battery module comprising an exterior case, a battery assembly housed in the exterior case, an inlet provided in an end wall of the exterior case, a fan attached to an inner surface of the end wall for blowing air sucked through the inlet into the interior of the exterior case, a standing wall portion having a facing surface facing the fan and a guide rib protruding from a lower portion of the facing surface toward the fan, and a leakage sensor extending along the facing surface and at least a part of which is arranged along the guide rib.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a battery module capable of accurately detecting the entry of liquid.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 10

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or corresponding elements are denoted by the same reference numerals throughout the drawings, and redundant detailed descriptions are omitted.

[0010] A battery module according to an embodiment of the present invention includes an exterior case, a battery assembly housed in the exterior case, an inlet provided in an end wall of the exterior case, a fan attached to an inner surface of the end wall and blowing air sucked through the inlet into the interior of the exterior case, an opposing surface facing the fan, a vertical wall portion having a guide rib protruding from a lower portion of the opposing surface toward the fan, and a leakage sensor extending along the opposing surface and at least a part of which is disposed along the guide rib.

[0011] According to the above configuration, the air blown out from the fan can cool heat-generating components such as, for example, the battery assembly. On the other hand, there is a possibility that liquid rides on the air flow formed by the fan and enters the interior from the outside of the exterior case through the inlet. The fan faces the opposing surface of the vertical wall portion. Therefore, the liquid sucked into the fan is blown out toward the opposing surface. The leakage sensor extends along this opposing surface. For this reason, when the liquid is blown out from the fan, the leakage sensor can favorably detect the entry of the liquid.

[0012] When the amount of liquid entering is small, the liquid tends to be blown out in a mist form. When the liquid is sprayed onto the leakage sensor, the leakage sensor may not be able to accurately detect that the liquid is being sprayed. However, the opposing surface of the vertical wall portion receives the mist-like liquid, and the mist-like liquid adheres to the opposing surface as droplets. The droplets entrain the droplets adhering to the opposing surface below and increase their size while flowing downward along the opposing surface by their own weight. A guide rib is provided at the lower portion of the opposing surface. The droplets are guided by the guide rib and collected at the lower portion of the opposing surface. At least a part of the leakage sensor is disposed along such a guide rib and can favorably detect the collected droplets. That is, even when the amount of liquid entering is small, the leakage sensor can accurately detect the entry of the liquid.

[0013] In a battery module according to another embodiment of the present invention, the liquid leakage sensor may include a horizontally extending portion that extends in the width direction along the lower edge of the facing surface.

[0014] According to the above configuration, since the horizontally extending portion extends in the width direction along the lower edge of the facing surface, droplets collected at the lower part of the facing surface are likely to touch the horizontally extending portion. Therefore, the detection accuracy of liquid entry is improved.

[0015] In a battery module according to another embodiment of the present invention, the guide rib may have a curved rib that curves toward the center side in the width direction of the facing surface as it goes downward, and the horizontally extending portion may be arranged along the inner surface of the curved rib.

[0016] According to the above configuration, the droplets are guided to the central and lower portions in the width direction of the facing surface along the inner surface of the curved rib. The droplets collected in this way are likely to touch the horizontally extending portion arranged along the inner surface of the curved rib. Therefore, the detection accuracy of liquid entry is improved.

[0017] In a battery module according to another embodiment of the present invention, the guide rib may be inclined downward as it goes toward the center side in the width direction and may have an inclined rib continuous with the upper end of the curved rib.

[0018] According to the above configuration, the inclined rib can receive droplets from a wide range of the facing surface and guide the received droplets to the curved rib. As a result, the amount of droplets collected by the curved rib, that is, the amount of droplets that can touch the horizontally extending portion, increases. Therefore, the detection accuracy of liquid entry is improved.

[0019] In a battery module according to another embodiment of the present invention, the liquid leakage sensor may include a first vertically extending portion that extends upward from one end in the width direction of the horizontally extending portion and a second vertically extending portion that extends upward from the other end in the width direction of the horizontally extending portion.

[0020] According to the above configuration, due to the presence of the first vertically extending portion and the second vertically extending portion, the liquid leakage sensor can be laid out over a wide range of the opposing surface. Therefore, the detection accuracy of liquid entry is improved. A part of the liquid is directly sprayed onto the first vertically extending portion and the second vertically extending portion. Therefore, when the amount of liquid entering is large, without waiting for dripping, the first vertically extending portion and the second vertically extending portion can sufficiently sense the entry of the liquid, and the liquid entry can be detected promptly.

[0021] In a battery module according to another embodiment of the present invention, the guide rib may have a first vertical rib and a second vertical rib that extend in the vertical direction and are separated from each other in the width direction, the first vertically extending portion may be arranged along the inner surface of the first vertical rib, and the second vertically extending portion may be arranged along the inner surface of the second vertical rib.

[0022] According to the above configuration, the liquid droplets are collected at the lower part of the opposing surface along the inner surface of the first vertical rib or the second vertical rib. The liquid droplets thus collected are likely to come into contact with the first vertically extending portion and the second vertically extending portion arranged along the inner surface of these vertical ribs. Therefore, the detection accuracy of liquid entry is improved.

[0023] In a battery module according to another embodiment of the present invention, a cylindrical first sleeve is wound around the connection portion between the first vertically extending portion and the signal line, the upper end portion of the first vertically extending portion is bent so as to face the other side in the width direction, and the first sleeve may extend from the first vertically extending portion to the other side in the width direction along the upper edge of the opposing surface.

[0024] According to the above configuration, the first sleeve is arranged along the upper edge of the opposing surface, that is, a portion that hardly contributes to the accumulation of liquid droplets on the opposing surface. Therefore, the liquid can be received over as wide a range as possible on the opposing surface, and the amount of liquid droplets collected by the guide rib also increases accordingly. Therefore, the detection accuracy of liquid entry is improved.

[0025] In a battery module according to another embodiment of the present invention, a cylindrical second sleeve is wound around a connection portion between the second longitudinally extending portion and the signal line, an upper end portion of the second longitudinally extending portion is folded downward, and the second sleeve may extend downward from the second longitudinally extending portion adjacent to the other side in the width direction of the second longitudinally extending portion.

[0026] According to the above configuration, the second sleeve extends in the vertical direction. The downward flow of droplets passing through the opposing surface is less likely to be inhibited by the second sleeve. The amount of droplets collected by the guide ribs can be ensured, and the detection accuracy of liquid entry is improved.

[0027] In a battery module according to another embodiment of the present invention, the standing wall portion may be a component separate from the battery assembly and may be interposed between the fan and the battery assembly.

[0028] According to the above configuration, since the standing wall portion is a component separate from the battery assembly, it is easy to optimize the shape of the standing wall portion and the arrangement of the liquid leakage sensor for the purpose of liquid accumulation. Therefore, the detection accuracy of liquid entry is improved.

[0029] Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "upper", "lower", and other terms including these terms) are used as necessary, but the use of these terms is for facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meanings of these terms. Also, portions denoted by the same reference numerals in a plurality of drawings indicate the same or equivalent portions or members. Furthermore, the embodiments shown below are specific examples of the technical idea of the present invention and do not limit the present invention thereto. Also, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention thereto alone without specific description, but are intended to be illustrative. Also, the content described in one embodiment or example is applicable to other embodiments or examples. Also, the sizes and positional relationships of the members shown in the drawings may be exaggerated for clarity of explanation.

[0030] The battery module of the present invention is applied to an emergency power source such as a battery backup unit (BBU). However, the present invention does not specify the use of the battery module, and it can be used as a power source for various other electrical devices, such as the power source of a vehicle driving motor.

[0031] Referring to FIGS. 1 to 4, the battery module 1 according to the first embodiment includes an exterior case 2, a battery assembly 3, a fan 5, a vertical wall portion 6, and a leakage sensor 7. The battery module 1 further includes a circuit unit 4.

[0032] The exterior case 2 has a rectangular parallelepiped shape and is rectangular when viewed in the height direction Z (i.e., in plan view). In the following description, the extending direction of the long side of this rectangle is defined as the longitudinal direction X, and the extending direction of the short side is defined as the width direction Y. The longitudinal direction X, the width direction Y, and the height direction Z are each orthogonal to the other two directions.

[0033] The exterior case 2 has a first end wall 21 and a second end wall 22 facing each other in the longitudinal direction X, a bottom wall 23 and a top wall 24 facing each other in the height direction Z, and a first side wall 25 and a second side wall 26 facing each other in the width direction Y. The exterior case 2 defines an internal space surrounded by these walls. The first end wall 21 is on one side in the longitudinal direction X (the lower left side in FIGS. 1, 3, and 4, and the left side in FIG. 2), extends upward from the end of the bottom wall 23, and is connected to the end of the top wall 24. The second end wall 22 is on the other side in the longitudinal direction X (the upper right side in FIGS. 1 and 3), and connects the ends of the bottom wall 23 and the top wall 24 to each other. The first side wall 25 is on one side in the width direction Y (the upper left side in FIGS. 1 and 3), and connects the first end wall 21 and the second end wall 22. The second side wall 26 is on the other side in the width direction Y (the lower right side in FIGS. 1 and 3), and connects the first end wall 21 and the second end wall 22.

[0034] The exterior case 2 has an inlet 27 provided in the first end wall 21 and an outlet 28 provided in the second end wall 22. Both the inlet 27 and the outlet 28 are constituted by a plurality of through holes, communicate the inside and the outside of the exterior case 2, and allow air for air-cooling the electrical components inside the exterior case 2 to pass through.

[0035] The outer case 2 has, as its components, a base 2A and a cover 2B that are separable in the height direction Z. The base 2A constitutes at least the bottom wall 23, and in this example, also constitutes the first side wall 25 and the second side wall 26. The cover 2B constitutes at least the top wall 24. In the present embodiment, the outer case 2 further has an end plate 2C that constitutes the first end wall 21 as its component. However, the component division of the outer case 2 can be changed as appropriate. The second end wall 22 may be integrated with the base 2A, may be integrated with the cover 2B, or may be constituted by a component separate from the base 2A and the cover 2B.

[0036] Inside the outer case 2, a fan 5, a liquid leakage sensor 7, a standing wall portion 6, a battery assembly 3, and a circuit unit 4 are accommodated in this order from one side to the other side in the longitudinal direction X.

[0037] The battery assembly 3 includes a plurality of battery cells (not shown) and a cell holder 31 that holds the plurality of battery cells in fixed positions. For example, the battery cells are non-aqueous electrolyte secondary batteries such as lithium-ion batteries and have cylindrical containers. However, the battery cells may be batteries other than cylindrical ones, such as square ones, and may also be batteries other than lithium-ion batteries, such as all-solid-state batteries.

[0038] The cell holder 31 is generally rectangular parallelepiped as a whole. Although detailed illustration is omitted, the plurality of battery cells are held in a vertical posture with their axial directions facing the height direction Z. The cell holder 31 has a plurality of accommodating portions that individually accommodate the plurality of battery cells. Each accommodating portion is cylindrical to accommodate the corresponding battery cell. On both end faces in the longitudinal direction X and both side faces in the width direction Y of the cell holder 31, a plurality of accommodating portions that form the contour of the arrangement region of the battery cells can be exposed in plan view. In this case, the surface of the cell holder 31 has irregularities due to the outer peripheral surfaces of these accommodating portions.

[0039] Note that the battery assembly 3 may include a current collecting structure and a heat transfer structure (not shown). The current collecting structure may have a lead plate made of a conductive material for electrically connecting the battery cells to each other. The heat transfer structure may have a sheet or plate made of a heat conductive material for taking heat away from the battery cells. These structures are stacked on the top surface or the bottom surface of the cell holder 31.

[0040] The circuit unit 4 may include a monitoring module for monitoring the state of the battery cells, a charge / discharge control module for controlling the charging and discharging of the battery cells, a voltage conversion module for converting the DC voltage transmitted from or to the battery cells (e.g., step-down, step-up, or both), a fan control module for controlling the air volume of the fan 5 according to the state (e.g., temperature) of the battery cells, and the like. Some of the modules exemplified here may be mounted on a substrate 49 disposed at a location independent of the circuit unit 4 (e.g., the space between the battery assembly 3 and the first end wall 21, or the space between the battery assembly 3 and the first side wall 25 or the second side wall 26). When the entry of liquid is detected by the liquid leakage sensor 7, the charge / discharge control module and the voltage conversion module stop some or all of their functions.

[0041] The fan 5 is, as an example, composed of a first fan 5A and a second fan 5B arranged in the width direction Y. The first fan 5A is, for example, an axial flow fan. The first fan 5A has a fan frame 51 having a rounded square shape when viewed in the axial direction, four bolt insertion holes 52 provided at the four corners of the fan frame 51, and an impeller (detailed illustration omitted) rotatably supported at the center of the fan frame 51. When the impeller rotates, the first fan 5A sucks air from behind the fan and blows the air forward of the fan. The second fan 5B is also configured in the same manner as the first fan 5A.

[0042] The fan 5 is attached to the inner surface of the first end wall 21. More specifically, the rear surface (the end face on the suction side) of the first fan 5A is directed toward the inner surface of the first end wall 21 so as to cover the inlet 27. Four bolts 11 are inserted into the first end wall 21 from the outer surface side in the other direction of the longitudinal direction X, passed through four bolt insertion holes 52, and screwed into nuts 12 provided on the front surface (the end face on the discharge side) side of the fan 5. The second fan 5B is similarly fastened to the first end wall 21. The first fan 5A and the second fan 5B are arranged adjacent to each other in the width direction Y and cover the first end wall 21, particularly its upper half, from the inside.

[0043] The fan 5 forms an air flow directed in its axial direction. The axial direction of the fan 5 corresponds to the longitudinal direction X of the battery module 1. The upstream side in the air flow direction corresponds to one side of the longitudinal direction X, and the downstream side corresponds to the other side of the longitudinal direction X. Air is sucked into the fan 5 immediately after passing through the inlet 27 and blown out from the fan 5 into the interior of the outer case 2. The air cools the battery assembly 3 and the circuit unit 4 in the process of flowing toward the other side of the longitudinal direction X inside the outer case 2. The air flows out of the outer case 2 through the outlet 28.

[0044] Here, during the use of the battery module 1, the outer surface of the outer case 2 may be wetted with a liquid. As an example, one or more battery modules 1 may be arranged in alignment on a shelf together with an external electronic device to serve as a BBU, and water cooling may be applied to cool this electronic device. If a coolant leak occurs in the water cooling system, the coolant may drip onto the outer surface of the top wall 24 of the outer case 2. Examples of the coolant (i.e., the liquid that can adhere to the outer case 2) include pure water, an ethylene glycol aqueous solution, or a propylene glycol aqueous solution.

[0045] Due to the action of the fan 5, a liquid (e.g., water) that wets the outer surface of the outer case 2 can be drawn toward the first end wall 21 and enter the interior of the outer case 2 through the inlet 27. The entered liquid passes through the inlet 27, the rear surface of the fan, and the fan frame 51 in sequence and is blown out riding on the air flow from the front surface of the fan.

[0046] The liquid leakage sensor 7 is, for example, of a cord type or a rope type. The liquid leakage sensor 7 includes a long and flexible string-shaped, rope-shaped, or strip-shaped detection cord 70. When a liquid (e.g., water) touches the detection cord 70, the liquid penetrates into the detection cord 70, and two electrode lines (not shown) inside the detection cord 70 are short-circuited through the liquid. The liquid leakage sensor 7 detects this short circuit electrically to detect the presence of a liquid around itself. When the liquid leakage sensor 7 is housed inside the exterior case 2 where there is essentially no liquid, the detection of the presence of a liquid means the detection of the entry of a liquid into the exterior case 2.

[0047] The rear surface of the fan 5 contacts the inner surface of the first end wall 21 or faces it with a slight clearance. The space behind the fan can be compressed, contributing to an improvement in the volumetric energy density of the battery module 1. On the other hand, when the clearance between the rear surface of the fan and the first end wall 21 is clogged, there is no room to dispose the liquid leakage sensor 7 on the liquid entry path (e.g., between the inlet 27 and the rear surface of the fan). In order for the liquid leakage sensor 7 to detect the entry of a liquid, it is required to dispose the liquid leakage sensor 7 in front of the fan inside the exterior case 2 so that as much liquid blown out riding on the air flow touches the liquid leakage sensor 7 as possible.

[0048] Depending on the amount of liquid entry (particularly, the entry flow rate per unit time), the particle size of the liquid blown out from the fan 5 can vary. When the amount of liquid entry is small, the particle size becomes small, and the liquid is sprayed from the fan 5 in a mist form. Therefore, the amount of liquid actually adhering to the liquid leakage sensor 7 becomes even less with respect to the originally small amount of liquid entry. Even if a part of the mist is directly sprayed onto the liquid leakage sensor 7, the amount of liquid adhesion per unit area is very small. A sufficient short circuit cannot occur at any part of the detection cord 70, making it difficult to detect the entry of a liquid.

[0049] Therefore, even when the liquid leakage sensor 7 is disposed in front of the fan, the battery module 1 is provided with a standing wall portion 6 in order to maintain or improve the detection accuracy of liquid entry. In the present embodiment, the standing wall portion 6 is composed of a component separate from the battery assembly 3, and more specifically, a component separate from the cell holder 31.

[0050] Hereinafter, with reference to FIGS. 5 to 7, the structure and arrangement of the standing wall portion 6 and the liquid leakage sensor 7 will be further described.

[0051] The standing wall portion 6 has a base plate 60 extending in the width direction Y and the height direction Z. Of the pair of surfaces of the base plate 60, the surface on one side in the longitudinal direction X (the lower left side in FIG. 5, the lower right side in FIG. 6) is an opposing surface 61 that faces the fan 5 in the longitudinal direction X (in other words, the air flow direction, the fan axis direction). The opposing surface 61 is a flat surface. The normal line of the opposing surface 61 is directed in the longitudinal direction X.

[0052] The base plate 60 includes a central portion 60c in the width direction Y, a first overhanging portion 60a protruding from the central portion 60c to one side in the width direction Y (the upper left side in FIG. 5, the lower left side in FIG. 6, the left side in FIG. 7), and a second overhanging portion 60b protruding from the central portion 60c to the other side in the width direction Y (the lower right side in FIG. 5, the upper right side in FIG. 6, the right side in FIG. 7).

[0053] The central portion 60c protrudes downward with respect to the first overhanging portion 60a and the second overhanging portion 60b. The lower edge of the first overhanging portion 60a and the lower edge of the second overhanging portion 60b extend linearly in the width direction Y. The lower edge of the second overhanging portion 60b is located slightly above the lower edge of the first overhanging portion 60a.

[0054] A through hole 60d is provided in the central portion 60c. As an example, the through hole 60d is rectangular, and a pair of long side edges extend parallel to each other in the height direction Z while being separated from each other in the width direction Y, and a pair of short side edges extend parallel to each other in the width direction Y while being separated from each other in the height direction Z. Electronic components such as fuses may be arranged in the through hole 60d.

[0055] Note that a through hole 60e is also provided in the first overhanging portion 60a. Further, the standing wall portion 6 integrally has side walls 69 that project from both edges in the width direction Y of the base plate 60 toward the other side in the longitudinal direction X (the upper right side in FIG. 5 and the upper left side in FIG. 6). The through hole 60e is in a shape provided for forming the side walls 69. The side walls 69 are used for fixing to the cell holder 31 by means such as snap fit or the like.

[0056] The standing wall portion 6 has guide ribs 62 that project from the lower part of the opposing surface 61 toward the fan 5. The guide ribs 62 mainly serve to guide and accumulate droplets adhering to the opposing surface 61.

[0057] The guide ribs 62 have curved ribs 62a that curve toward the center side in the width direction Y of the opposing surface 61 as they go downward.

[0058] The curved rib 62a is in a semi-circular shape that is convex downward when viewed in the longitudinal direction X, and has a lower end located at the center in the width direction Y and a pair of upper ends located on opposite sides of the lower end in the width direction Y. The curved rib 62a is in a shape obtained by stretching a semi-circle in the width direction Y. In other words, the height (the distance in the height direction Z between the upper end and the lower end) of the curved rib 62a is shorter than the width (the distance in the width direction Y between the pair of upper ends) of the curved rib 62a.

[0059] The curved rib 62a projects from the edge of the downward protruding portion of the central portion 60c of the base plate 60 toward one side in the longitudinal direction X. The downward protruding portion is a portion that protrudes downward with respect to the first overhanging portion 60a and the second overhanging portion 60b as described above. The lower end of the curved rib 62a is located at the lower end of the standing wall portion 6 as a whole and at the center in the width direction Y of the standing wall portion 6 as a whole.

[0060] In this embodiment, a notch 62b is provided at the lower end of the curved rib 62a, and the curved rib 62a is composed of a pair of split ribs that are divided in the width direction Y through the notch 62b. Each split rib is in a shape obtained by stretching a 1 / 4 arc in the width direction Y when viewed in the longitudinal direction X, and curves toward the center side in the width direction Y as it goes downward.

[0061] The guide rib 62 is inclined downward as it goes toward the center side in the width direction Y, and further has an inclined rib 62c that is continuous with the upper end of the curved rib 62a.

[0062] In this embodiment, one inclined rib 62c is continuous with the upper end on one side in the width direction Y of the curved rib 62a (that is, the upper end of the split rib on one side in the width direction Y). On the other side in the width direction Y, the guide rib 62 terminates at the upper end on the other side in the width direction Y of the curved rib 62a, and on one side in the width direction Y, it terminates at the upper end of the inclined rib 62c.

[0063] The inclined rib 62c extends from the lower corner on the center side and lower side in the width direction Y of the first overhanging portion 60a to one side and upper side in the width direction Y. The inclined rib 62c is provided at the lower end portion of the first overhanging portion 60a. The inclined rib 62c extends linearly. The upper end of the inclined rib 62c reaches near the edge or corner of the through hole 60e.

[0064] The liquid leakage sensor 7 extends along the opposing surface 61 of the standing wall portion 6, and at least a part of it is arranged along the guide rib 62. The liquid leakage sensor 7 includes a long detection cord 70 having flexibility.

[0065] Although detailed illustration is omitted, the detection cord 70 includes two electrode wires, an internal braid surrounding each electrode wire, and an external braid surrounding the two electrode wires wound by the internal braid together. The external braid and the internal braid are made of chemical fibers such as polyester or polyethylene, etc. When liquid adheres to the outer surface of the detection cord 70, the liquid can reach the electrode wires. When the liquid shorts the two electrode wires, the liquid leakage sensor 7 detects the liquid based on the resistance change between the electrode wires.

[0066] In a state where the liquid leakage sensor 7 is assembled to the vertical wall portion 6, the detection code 70 forms a U shape when viewed in the longitudinal direction X and includes a horizontally extending portion 71, a first vertically extending portion 72, and a second vertically extending portion 73. The horizontally extending portion 71 extends in the width direction Y along the lower edge of the opposing surface 61. The first vertically extending portion 72 extends upward from one side in the width direction Y of the horizontally extending portion 71. The second vertically extending portion 73 extends upward from the other side in the width direction Y of the horizontally extending portion 71.

[0067] Both end portions of the detection code 70 are connected to the signal lines 79a and 79b. The signal line 79a is electrically and mechanically connected to two electrode lines in the detection code 70 by welding. The same applies to the signal line 79b.

[0068] The battery module 1 includes a first sleeve 77 that protects the connection portion between the end portion of the first vertically extending portion 72 (i.e., one end portion of the detection code 70) and the signal line 79a, and a second sleeve 78 that protects the connection portion between the end portion of the second vertically extending portion 73 (i.e., the other end portion of the detection code 70) and the signal line 79b. Both the first sleeve 77 and the second sleeve 78 are cylindrical with a larger diameter than the detection code 70 and are wound around the corresponding connection portions.

[0069] The horizontally extending portion 71 is arranged along the inner surface of the curved rib 62a. The horizontally extending portion 71 is semicircular with a downward convex shape when viewed in the longitudinal direction X, following the shape of the curved rib 62a.

[0070] The first vertically extending portion 72 extends in the vertical direction along the long side edge of the through hole 60d near the boundary between the central portion 60c and the first overhanging portion 60a. The upper end portion of the first vertically extending portion 72 is bent at a right angle near the upper edge of the opposing surface 61 so as to face the other side in the width direction Y.

[0071] The first sleeve 77 extends linearly from the end of the first longitudinally extending portion 72 toward the other side in the width direction Y along the upper edge of the facing surface 61 and the upper edge of the through hole 60d. The first sleeve 77 reaches the second protruding portion 60b. The signal line 79a extends downward along the facing surface 61 of the second protruding portion 60b from the end on the other side in the width direction Y of the first sleeve 77, and then extends toward the other side in the longitudinal direction X through the wiring slot 63. The wiring slot 63 is provided in the side wall 69 on the other side in the width direction Y.

[0072] The second longitudinally extending portion 73 extends in the vertical direction along the long side edge of the through hole 60d near the boundary between the central portion 60c and the second protruding portion 60b. The upper end portion of the second longitudinally extending portion 73 is folded back downward in a hairpin shape. This folded-back portion is located directly below the first sleeve 77.

[0073] The second sleeve 78 extends linearly downward from the end of the second longitudinally extending portion 73 adjacent to the other side in the width direction Y of the second longitudinally extending portion 73. The second sleeve 78 is disposed along the facing surface of the second protruding portion 60b, and the lower end of the second sleeve 78 is located below the lower edge of the second protruding portion 60b. The signal line 79b extends toward the other side in the longitudinal direction X from the lower end of the second sleeve 78.

[0074] The standing wall portion 6 further includes a sensor clamp 64, a sensor hook 65, and a sensor guide 66. The sensor clamp 64, the sensor hook 65, and the sensor guide 66 also protrude from the facing surface 61 toward the fan 5, similar to the guide rib 62. The sensor clamp 64, the sensor hook 65, and the sensor guide 66 mainly serve to hold the liquid leakage sensor 7 in a fixed position along the facing surface 61.

[0075] The sensor clamp 64 is composed of a pair of locking pieces protruding from the facing surface 61, and claws protruding so as to approach each other are provided at the tips of the pair of locking pieces. The sensor clamp 64 includes a bottom clamp 64a, a first side clamp 64b, a second side clamp 64c, a first sleeve clamp 64d, and a second sleeve clamp 64e.

[0076] The bottom clamp 64a is disposed in the notch 62b and sandwiches the central portion of the lateral extension portion 71 in the width direction Y. The first side clamp 64b is provided near the boundary between the central portion 60c and the first overhanging portion 60a and sandwiches the central portion of the first longitudinal extension portion 72 in the height direction Z. The second side clamp 64c is provided near the boundary between the central portion 60c and the second overhanging portion 60b and sandwiches the root of the hairpin portion of the second longitudinal extension portion 73. The first sleeve clamp 64d is disposed between the upper edge of the through hole 60d and the upper edge of the facing surface 61 and sandwiches the first sleeve 77. The second sleeve clamp 64e is disposed at the central portions in both the height direction Z and the width direction Y of the second overhanging portion 60b and sandwiches the second sleeve 78.

[0077] The sensor hook 65 consists of one locking piece protruding from the facing surface 61. The sensor hooks 65 are disposed on both sides of the bottom clamp 64a in the width direction Y and lock the lateral extension portion 71 from above. The lateral extension portion 71 is restricted in its posture and position so as to pass through the narrow space between the sensor hook 65 and the curved rib 62a.

[0078] The sensor guide 66 consists of a ridge or rib protruding from the facing surface 61. The sensor guide 66 includes a first side guide 66a, a second side guide 66b, a third side guide 66c, a first top guide 66d, and a second top guide 66e.

[0079] The first side guide 66a extends in the height direction Z along one side edge of the through hole 60d in the width direction Y. The first longitudinal extension portion 72 is disposed along the first side guide 66a and is thereby held in a posture extending in the height direction Z and at a position close to the through hole 60d. The second side guide 66b extends in the height direction Z along the other side edge of the through hole 60d in the width direction Y. The second longitudinal extension portion 73 is disposed along the second side guide 66b and is thereby held in a posture extending in the height direction Z and at a position close to the through hole 60d.

[0080] The first top guide 66d and the second top guide 66e extend in the width direction Y along the upper edge of the facing surface 61. The first top guide 66d is disposed on one side in the width direction Y with respect to the first sleeve clamp 64d, and guides the right-angle bending of the upper end portion of the first longitudinally extending portion 72. The second top guide 66e is provided on the second overhanging portion 60b, and guides the downward extension of the tip end portion of the first sleeve 77 and the signal line 79a.

[0081] The third side guide 66c extends in the height direction Z at the center in the width direction Y of the second overhanging portion 60b. The upper portion of the third side guide 66c guides the hairpin bending of the second longitudinally extending portion 73, and the lower portion of the third side guide 66c guides the downward extension of the second sleeve 78.

[0082] Referring to FIG. 7, the axis of the first fan 5A passes through the first overhanging portion 60a. The axis of the second fan 5B passes through the second overhanging portion 60b. The liquid blown out from the first fan 5A is received by the facing surface 61 of the first overhanging portion 60a. The liquid blown out from the second fan 5B is received by the facing surface 61 of the second overhanging portion 60b.

[0083] When the liquid inflow rate (inflow rate per unit time) is large, the liquid is blown onto the facing surface 61 as droplets having a certain particle size. When the air volume of the fan 5 is large, the droplets fly in the longitudinal direction X. A sufficient amount of liquid adheres to the first longitudinally extending portion 72 and the second longitudinally extending portion 73 to short-circuit the electrode wires in the detection code 70. Therefore, when the liquid inflow rate is large, particularly when the air volume of the fan 5 is large, the liquid inflow can be detected early and accurately.

[0084] When the liquid inflow rate is large and the air volume of the fan 5 is small, the droplets fly in the longitudinal direction X while falling. Therefore, the droplets are received at the lower portions of the first overhanging portion 60a and the second overhanging portion 60b. The liquid received by the facing surface 61 becomes droplets on the facing surface 61. The droplets flow downward along the facing surface 61 under their own weight while entraining the droplets adhering to the facing surface 61 below.

[0085] In this embodiment, the vertical wall portion 6 is constituted by a separate component separated from the battery assembly 3. Therefore, it is easy to form the opposing surface 61 flat. Compared with the case where the opposing surface 61 has irregularities, it is easier to control the direction in which the droplets flow down.

[0086] The droplets adhering to the opposing surface 61 of the first protruding portion 60a reach the inner surface of the inclined rib 62c. Since the tip of the inclined rib 62c approaches the edge or corner of the through hole 60e, the inclined rib 62c can capture almost all of the droplets adhering to the first protruding portion 60a. The droplets are guided along the inclination of the inclined rib 62c toward the center side and downward in the width direction Y and reach the inner surface of the curved rib 62a. The curved rib 62a is semi-circular, and at the connection point between the curved rib 62a and the inclined rib 62c, the tangent line is substantially vertically downward. When the droplets reach the curved rib 62a, they quickly flow downward. At the lower part of the curved rib 62a, the droplets quickly flow toward the center side in the width direction Y by the conversion from potential energy to kinetic energy. In this way, the droplets adhering to the first protruding portion 60a are collected at the lower end of the curved rib 62a.

[0087] Around the lower end of this curved rib 62a, the central portion in the width direction Y of the horizontally extending portion 71 is held by the bottom clamp 64a and the sensor hook 65. The droplets collected at the lower end of the curved rib 62a penetrate into the central portion in the width direction Y of the horizontally extending portion 71. Due to the liquid accumulation effect by the guide rib 62, a liquid volume sufficient to cause a short circuit of the electrode line adheres to the horizontally extending portion 71. Therefore, even when the air volume of the fan 5 is small, the liquid entry can be accurately detected.

[0088] The same applies when the amount of liquid entering is small. When the amount of liquid entering is small, the particle size of the liquid becomes small and the liquid becomes misty. The misty liquid can directly adhere to the first longitudinally extending portion 72 and the second longitudinally extending portion 73, but there is a possibility that a sufficient amount of liquid cannot be ensured for the short circuit of the electrode wire. However, the opposing surface 61 can also receive the misty liquid. The received liquid becomes droplets in the same manner as described above. The behavior of the droplets thereafter is also the same as described above. The liquid is collected at the lower end of the curved rib 62a, and a sufficient amount of liquid for short-circuiting the electrode wire can be adhered to the laterally extending portion 71. Therefore, although it may take time for detection compared to the case where the amount of liquid entering is large and the air volume of the fan 5 is large, even when the amount of liquid entering is small, the liquid entry can be accurately detected.

[0089] Next, with reference to FIGS. 8 to 10, the battery module 1 according to the second embodiment will be described focusing on the differences from the first embodiment.

[0090] In the present embodiment, the curved rib 62a and the notch 62b (see FIGS. 5 to 7) of the first embodiment are omitted. Along with the omission of the curved rib 62a, the downward protruding portion of the central portion 60c of the base plate 60 has a rectangular shape when viewed in the longitudinal direction X. Further, instead of the omission of the curved rib 62a, the guide rib 62 has a first longitudinal rib 62d and a second longitudinal rib 62e that extend in the height direction Z apart from each other in the width direction Y.

[0091] The first longitudinal rib 62d protrudes from the edge on one side in the width direction Y (the upper left side in FIG. 8, the lower left side in FIG. 9, the left side in FIG. 10) of the downward protruding portion of the central portion 60c of the base plate 60 to one side in the longitudinal direction X (the lower left side in FIG. 8, the lower right side in FIG. 9). The second longitudinal rib 62e protrudes from the edge on the other side in the width direction Y (the lower right side in FIG. 8, the upper right side in FIG. 9, the right side in FIG. 10) of the downward protruding portion of the central portion 60c of the base plate 60 to one side in the longitudinal direction X.

[0092] In the first embodiment (refer to FIGS. 5 to 7), the horizontally extending portion 71 is arranged along the curved rib 62a. In this embodiment, with the omission of the curved rib 62a, the horizontally extending portion 71 linearly extends in the width direction Y along the lower edge of the central portion 60c. Instead, the lower ends of the first vertically extending portion 72 and the second vertically extending portion 73 reach the lower end of the central portion 60c and are continuous with the horizontally extending portion 71. The first vertically extending portion 72 is arranged along the inner surface of the first vertical rib 62d. The second vertically extending portion 73 is arranged along the inner surface of the second vertical rib 62e.

[0093] In this embodiment, the battery module 1 includes an elastic support 67 instead of the bottom clamp 64a (refer to FIGS. 5 to 7) of the first embodiment. The elastic support 67 is provided at the lower end of the central portion 60c and elastically supports the horizontally extending portion 71 from above. The pair of sensor hooks 65 further includes a hanging piece that hangs downward from the tip of the locking piece. The horizontally extending portion 71 is held in the space surrounded by the locking piece and the hanging piece of the sensor hook 65.

[0094] In this embodiment, with the omission of the curved rib 62a, the lower end of the inclined rib 62c is continuous with the upper end of the first vertical rib 62d.

[0095] In this embodiment, the first side clamps are paired vertically, and the second side clamps are paired vertically. The sensor clamp 64 includes an upper first side clamp 64p, a lower first side clamp 64q, an upper second side clamp 64r, and a lower second side clamp 64s.

[0096] The upper first side clamp 64p sandwiches the base of the right-angled bent portion of the first vertically extending portion 72. The upper second side clamp 64r is arranged and configured in the same manner as the second side clamp 64c of the first embodiment, and sandwiches the base of the hairpin portion of the second vertically extending portion 73.

[0097] The lower first side clamp 64q and the lower second side clamp 64s are provided at the downward protruding portion of the central portion 60c. The lower first side clamp 64q sandwiches the lower end portion of the first longitudinally extending portion 72. The lower second side clamp 64s sandwiches the lower end portion of the second longitudinally extending portion 73.

[0098] The lower first side clamp 64q is positioned slightly closer to the center in the width direction Y than the upper first side clamp 64p. Therefore, the first longitudinally extending portion 72 extends so as to gently form an S shape at the lower end portion. The first longitudinally extending portion 72 bulges outward in the width direction Y at the continuous portion with the horizontally extending portion 71 (that is, the lower end of the first longitudinally extending portion 72), and is in contact with or close to the inner surface of the first longitudinal rib 62d. Note that the lower end portion of the first longitudinal rib 62d is inclined so as to face the center in the width direction Y as it goes downward. This inclination also contributes to shortening the distance between the inner surface of the first longitudinal rib 62d and the detection code 70.

[0099] The relationship between the lower second side clamp 64s and the upper second side clamp 64r is the same as described above. The second longitudinally extending portion 73 extends so as to gently form an S shape at the lower end portion. The lower end portion of the second longitudinal rib 62e is inclined so as to face the center in the width direction Y as it goes downward. The lower end of the second longitudinally extending portion 73 is in contact with or close to the inner surface of the second longitudinal rib 62e.

[0100] Also in this embodiment, when the liquid is sprayed onto the facing surface 61, it becomes droplets on the facing surface 61. The droplets fall downward along the facing surface 61. The droplets are guided by the guide rib 62 and flow downward along the lower surface of the first longitudinal rib 62d or the second longitudinal rib 62e. When the droplets reach the lower ends of the first longitudinal rib 62d and the second longitudinal rib 62e, they adhere to the detection code 70. Thereby, the liquid leakage sensor 7 can accurately detect the entry of the liquid.

[0101] Although the embodiments have been described so far, the above configuration is merely an example and can be appropriately changed within the scope of the present invention.

[0102] A pair of inclined ribs 62c may be continuous with both ends of the curved rib 62a (refer to the first embodiment) or the upper ends of the pair of first vertical ribs 62d, 62e (refer to the second embodiment), respectively.

[0103] The vertical wall portion 6 does not have to be a dedicated part. For example, the vertical wall portion 6 may be integrated with the cell holder 31.

Explanation of Reference Numerals

[0104] 1 Battery module 2 Exterior case 2A Base 2B Cover 2C End plate 3 Battery assembly 4 Circuit unit 5 Fan 5A First fan 5B Second fan 6 Vertical wall portion 7 Leakage sensor 11 Bolt 12 Nut 21 First end wall 22 Second end wall 23 Bottom wall 24 Top wall 25 First side wall 26 Second side wall 27 Inlet 28 Outlet 31 Cell holder 49 Substrate 51 Fan frame 52 Bolt insertion hole 60 Base plate 60a First overhanging portion 60b Second overhanging portion 60c Central portion 60d, 60e Through hole 61 Opposing surface 62 Guide rib 62a Curved rib 62b Notch 62c Inclined rib 62d First vertical rib 62e Second longitudinal rib 63 Wiring slot 64 Sensor clamp 64a Bottom clamp 64b First side clamp 64c Second side clamp 64d First sleeve clamp 64e Second sleeve clamp 64p Upper first side clamp 64q Lower first side clamp 64r Upper second side clamp 64s Lower second side clamp 65 Sensor hook 66 Sensor guide 66a First side guide 66b Second side guide 66c Third side guide 66d First top guide 66e Second top guide 67 Elastic support 69 Side wall 70 Detection code 71 Lateral extension 72 First longitudinal extension 73 Second longitudinal extension 77 First sleeve 78 Second sleeve 79a, 79b Signal wires X Longitudinal direction Y Width direction Z Height direction

Claims

1. An outer case, a battery assembly housed in the outer case, an inlet provided in an end wall of the outer case, a fan attached to an inner surface of the end wall and blowing air sucked through the inlet into the interior of the outer case, a standing wall portion having a facing surface facing the fan and a guide rib protruding from a lower portion of the facing surface toward the fan, a liquid leakage sensor extending along the facing surface and at least a part of which is disposed along the guide rib, A battery module comprising:

2. The battery module according to claim 1, wherein the liquid leakage sensor includes a horizontally extending portion extending in a width direction along a lower edge of the facing surface.

3. The battery module according to claim 2, wherein the guide rib has a curved rib that curves toward a center side in the width direction of the facing surface as it goes downward, and the horizontally extending portion is disposed along an inner surface of the curved rib.

4. The battery module according to claim 3, wherein the guide rib has an inclined rib that inclines downward as it goes toward the center side in the width direction and is continuous with an upper end of the curved rib.

5. The battery module according to claim 2, wherein the liquid leakage sensor includes a first vertically extending portion extending upward from an end on one side in the width direction of the horizontally extending portion and a second vertically extending portion extending upward from an end on the other side in the width direction of the horizontally extending portion.

6. The battery module according to claim 5, wherein the guide rib has a first vertical rib and a second vertical rib that extend in the vertical direction while being separated from each other in the width direction, the first vertically extending portion is disposed along an inner surface of the first vertical rib, and the second vertically extending portion is disposed along an inner surface of the second vertical rib.

7. A cylindrical first sleeve is wound around a connection portion between the first vertically extending portion and a signal line, an upper end portion of the first vertically extending portion is bent so as to face the other side in the width direction, and the first sleeve extends from the first vertically extending portion along an upper edge of the facing surface to the other side in the width direction. The battery module according to claim 5.

8. A cylindrical second sleeve is wound around a connection portion between the second vertically extending portion and a signal line, an upper end portion of the second vertically extending portion is folded back downward, and the second sleeve extends downward from the second vertically extending portion adjacent to the other side in the width direction of the second vertically extending portion. The battery module according to claim 7.

9. The vertical wall portion is a component separate from the battery assembly and is interposed between the fan and the battery assembly. The battery module according to any one of claims 1 to 8.

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