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 out the air sucked through the inlet 27 into the interior of the exterior case 2, a standing wall portion 6 disposed between the battery assembly 3 and the fan 5 and having an opposing surface 61 facing the fan 5, and a liquid leakage sensor 7 disposed below the opposing surface 61.

Description

[Technical Field]

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

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

[0003] [Patent Document 1] International Publication No. 2018 / 123573 Summary of the Invention [Problem to be solved by the invention]

[0004] In one example of a battery module usage scenario, one or more battery modules are arranged on a shelf together with water-cooled electronic devices. If a coolant leak occurs, the coolant may enter the battery module case through the cooling air inlet or outlet. Liquid intrusion may also occur in other usage scenarios.

[0005] An object of the present invention is to provide a battery module that can accurately detect the intrusion of liquid. [Means for solving the problem]

[0006] One aspect of the present invention provides a battery module including 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 vertical wall portion disposed between the battery assembly and the fan and having a facing surface facing the fan, and a leakage sensor disposed below the facing surface.

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]

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Figure 12

Embodiment 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, a standing wall portion disposed between the battery assembly and the fan and having a facing surface facing the fan, and a liquid leakage sensor disposed below the facing surface.

[0011] According to the above configuration, the air blown out from the fan can cool heat-generating components such as a battery assembly, for example. 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 facing surface of the standing wall portion.

[0012] Here, when the air volume of the fan is large, the liquid sucked into the fan is strongly blown out together with the air from the fan, strongly blown against the facing surface, and adheres to the facing surface as liquid droplets. The liquid droplets entrain the liquid adhering to the facing surface below, increase in size, and flow downward along the facing surface by their own weight. The liquid leakage sensor is disposed below such a facing surface. Therefore, the liquid leakage sensor can satisfactorily detect the liquid droplets flowing down the facing surface.

[0013] When the air volume of the fan is small, the liquid sucked into the fan descends by its own weight while flying in the air flow direction. For this reason, there is a possibility that the liquid does not adhere to the facing surface as described above. However, since the liquid leakage sensor is disposed below the facing surface, the liquid blown out from the fan is directly blown against the liquid leakage sensor, and the entry of the liquid can be satisfactorily detected.

[0014] Thus, a battery module capable of accurately detecting the entry of liquid can be provided regardless of the air volume of the fan.

[0015] The liquid leakage sensor may be disposed below the fan.

[0016] According to the above configuration, when the air volume of the fan is small, it becomes easier for the liquid flying while descending from the fan to directly adhere to the liquid leakage sensor.

[0017] In an electric module according to another embodiment of the present invention, the lower end portion of the standing wall portion may be inclined so as to move away from the fan as it goes downward.

[0018] According to the above configuration, the liquid droplets on the opposing surface flow along the inclination away from the fan at the lower end portion of the standing wall portion and fall from the tip of the inclination. While ensuring the distance between the liquid leakage sensor and the fan, it becomes possible to drop the liquid collected on the opposing surface onto the liquid leakage sensor. It is possible to achieve both securing the arrangement space of the liquid leakage sensor and improving the detection accuracy of liquid entry.

[0019] In an electric module according to another embodiment of the present invention, the standing wall portion may be V-shaped and inclined so as to move away from the fan as it goes from the center in the width direction toward both outer sides in a plan view.

[0020] According to the above configuration, while enabling the standing wall portion to receive the liquid, the air can be guided in a direction away from the fan. It is possible to achieve both improvement in the detection accuracy of liquid entry and improvement in the air cooling performance.

[0021] An electric module according to another embodiment of the present invention further includes an exhaust duct that forms an exhaust passage for guiding the gas discharged from the battery assembly, and the exhaust duct may have the standing wall portion.

[0022] According to the above configuration, the exhaust duct having a function of guiding gas also has a function of receiving liquid. The number of parts of the battery module can be reduced, and the peripheral structure of the liquid leakage sensor becomes compact.

[0023] In the electric module according to another embodiment of the present invention, the exhaust passage guides the gas while meandering from the space on the battery assembly side with respect to the standing wall portion, through an outlet below the lower edge of the standing wall portion, to the space on the fan side with respect to the standing wall portion, and the liquid leakage sensor may be disposed at the outlet.

[0024] According to the above configuration, since the discharge passage has a labyrinth shape, the gas can be cooled down before being discharged outside the exterior case. The liquid leakage sensor is disposed using an opening portion for forming the labyrinth. Compared with the case of securing a dedicated space for disposing the liquid leakage sensor, the peripheral structure of the liquid leakage sensor becomes compact.

[0025] The electric module according to another embodiment of the present invention may be disposed between the battery assembly and the fan, and may further include a sensor holder that holds the liquid leakage sensor.

[0026] According to the above configuration, by providing a dedicated component for holding the sensor, the positioning and assembly of the liquid leakage sensor become easy.

[0027] 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 those terms) are used as necessary, but the use of those 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 those terms. Also, parts denoted by the same reference numerals in a plurality of drawings indicate the same or equivalent parts 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 below. Also, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention only thereto 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.

[0028] The battery module of the present invention is applied to an emergency power source such as a battery backup unit (BBU), for example. 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.

[0029] Referring to FIGS. 1 to 3, the battery module 1 according to this 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 first circuit unit 4A, a second circuit unit 4B, an exhaust duct 8, and a sensor holder 9.

[0030] The exterior case 2 has a rectangular parallelepiped shape and is rectangular when viewed in the height direction Z (that is, 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.

[0031] 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 extends upward from an end of the bottom wall 23 on one side in the longitudinal direction X (the lower left side in FIGS. 1 and 3, the left side in FIG. 2) and is connected to an end of the top wall 24. The second end wall 22 connects the ends of the bottom wall 23 and the top wall 24 on the other side in the longitudinal direction X (the upper right side in FIGS. 1 and 3). The first side wall 25 connects the first end wall 21 and the second end wall 22 on one side in the width direction Y (the upper left side in FIGS. 1 and 3). The second side wall 26 connects the first end wall 21 and the second end wall 22 on the other side in the width direction Y (the lower right side in FIGS. 1 and 3).

[0032] 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 composed of 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 in the exterior case 2 to pass through.

[0033] The exterior 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 also constitutes the first side wall 25 and the second side wall 26 in this example. The cover 2B constitutes at least the top wall 24. In the present embodiment, the exterior case 2 further has an end plate 2C that constitutes the first end wall 21 as its component. However, the component division of the exterior 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.

[0034] Inside the outer case 2, a fan 5, a liquid leakage sensor 7, an exhaust duct 8, a battery assembly 3, and a first circuit unit 4A are accommodated in this order from one side to the other side in the longitudinal direction X. The liquid leakage sensor 7 is held by a sensor holder 9 and is located below the standing wall portion 6. The standing wall portion 6 is disposed between the fan 5 and the battery assembly 3 and also forms a part of the exhaust duct 8.

[0035] The battery assembly 3 includes a plurality of battery cells 30 (only one is shown in FIG. 2) and a cell holder 31 that holds the plurality of battery cells 30 in fixed positions. For example, the battery cell 30 is a non-aqueous electrolyte secondary battery such as a lithium-ion battery and has a cylindrical container. However, the battery cell 30 may be a battery other than a cylindrical one such as a rectangular shape, or may be a battery other than a lithium-ion battery such as an all-solid-state battery.

[0036] The cell holder 31 is generally rectangular parallelepiped as a whole. Although detailed illustration is omitted, the plurality of battery cells 30 are held in a vertically placed posture with their axial directions facing the height direction Z. The cell holder 31 has a plurality of accommodating portions 31a that individually accommodate the plurality of battery cells 30. Each accommodating portion 31a is cylindrical to accommodate the corresponding battery cell.

[0037] The battery assembly 3 includes 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 to electrically connect the battery cells 30 to each other. The heat transfer structure may have a sheet or plate made of a heat-conductive material to take heat away from the battery cells 30. These structures are stacked on the top surface or the bottom surface of the cell holder 31 and form a block body together with the cell holder �1.

[0038] The battery assembly 3 has a support plate 32 that supports such a block body from below. The support plate 32 is flat and is fixed to the bottom wall 23 of the outer case 2. The support plate 32 has a folded-back piece 32a that is folded upward from one end in the longitudinal direction X. The block body is located on the other side in the longitudinal direction X with respect to the folded-back piece 32a.

[0039] The first circuit unit 4A is disposed between the battery assembly 3 and the second end wall 22. The second circuit unit 4B is housed in a space surrounded by the inner surface of the first end wall 21, the inner surface of the bottom wall 23, and the lower surface of the fan 5.

[0040] The first circuit unit 4A and the second circuit unit 4B may include a monitoring module for monitoring the state of the battery cell 30, a charge / discharge control module for controlling the charging and discharging of the battery cell 30, a voltage conversion module for converting (e.g., stepping down, stepping up, or both) the DC voltage transmitted from or to the battery cell 30, a fan control module for controlling the air volume of the fan 5 according to the state (e.g., temperature) of the battery cell 30, and the like. Note that some of the modules exemplified here may be mounted on a substrate (not shown) disposed in another location (e.g., a 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, for example, an axial flow fan. The fan 5 has a fan frame 51 that is square with rounded corners when viewed in the axial direction, four bolt insertion holes 52 provided at the four corners of the fan frame 51, and an impeller 53 rotatably supported at the center of the fan frame 51. When the impeller 53 rotates, the fan 5 sucks air from behind the fan and blows the air forward of the fan.

[0042] The fan 5 is attached to the inner surface of the first end wall 21 and covers the first end wall 21 (especially its upper half from the inside). More specifically, the rear surface (the end face on the suction side) of the fan 5 is directed toward the inner surface of the first end wall 21 so as to cover the inlet 27. Four bolts 59 are inserted into the first end wall 21 from the outer surface side toward the other side in the longitudinal direction X, inserted through the four bolt insertion holes 52, and screwed into the fan frame 51.

[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. The 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 first circuit unit 4A as it flows 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 get wet 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 this coolant (i.e., the liquid that can adhere to the outer case 2) include water, an ethylene glycol aqueous solution, or a propylene glycol aqueous solution.

[0045] Due to the action of the fan 5, the 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 of the fan, and the fan frame 51 in sequence and is blown out riding on the air flow from the front 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 cord-shaped, rope-shaped, or strip-shaped detection cord 70. When a liquid (for example, 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 the 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 arrange the liquid leakage sensor 7 on the liquid entry path (for example, 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 arrange the liquid leakage sensor 7 in front of the fan inside the exterior case 2 so that as much of the liquid blown out riding on the air flow touches the liquid leakage sensor 7 as possible.

[0048] In order to maintain or improve the detection accuracy of liquid entry when the liquid leakage sensor 7 is arranged in front of the fan, the battery module 1 is provided with a standing wall portion 6. Hereinafter, with reference to FIGS. 4 to 10, the structure and arrangement of the standing wall portion 6, the liquid leakage sensor 7, the exhaust duct 8, and the sensor holder 9 will be further described. In FIGS. 4 to 10, the illustration of the cover 2B of the exterior case 2 is omitted.

[0049] The exhaust duct 8 is arranged close to one side in the longitudinal direction X of the battery assembly 3. The exhaust duct 8 forms an exhaust path 80 for guiding the gas discharged from the battery assembly 3.

[0050] In this regard, the battery cell 30 is provided with an exhaust valve (not shown) that opens in response to an increase in internal pressure. When the exhaust valve opens, gas is released from the inside of the battery cell 30 to the outside, optionally accompanied by a spark. The battery assembly 3 includes a gas guiding structure (not shown) that guides the gas released from the battery cell 30 along the top or bottom surface of the cell holder 31 in the longitudinal direction X. Similar to the current collecting structure and the heat transfer structure described above, the gas guiding structure is also overlaid on the top or bottom surface of the cell holder 31. A part of the gas is released from the battery assembly 3 to one side in the longitudinal direction X, passes through the exhaust passage 80, and is discharged to the outside of the outer case 2 through the inlet 27.

[0051] The exhaust duct 8 has a standing wall portion 6. The exhaust duct 8 further has a back plate 81 that is located between the standing wall portion 6 and the battery assembly 3 in the longitudinal direction. The standing wall portion 6 and the back plate 81 are manufactured by pressing sheet metal such as stainless steel, for example.

[0052] The back plate 81 is U-shaped when viewed in the longitudinal direction X. The back plate 81 has a lower portion 81a that extends in the width direction Y on the lower side, and a pair of side portions 81b that extend upward from both sides of the lower portion 81a in the width direction Y. The lower portion 81a and the pair of side portions 81b define a rectangular notch. The cover 2B of the outer case 2 covers this notch from above, thereby defining the inlet 80a of the exhaust passage 80.

[0053] The back plate 81 has a pair of inner ribs 81c that protrude from the inner edges of each of the pair of side portions 81b (that is, both edges of the inlet 80a in the width direction Y) toward one side in the longitudinal direction X. The back plate 81 has a pair of outer ribs 81d that are folded back from the outer edges of each of the pair of side portions 81b toward one side in the longitudinal direction X. Both the inner ribs 81c and the outer ribs 81d are rectangular in shape, long in the height direction Z and short in the longitudinal direction X when viewed in the width direction Y, and the outer ribs 81d are longer than the inner ribs 81c both in the height direction Z and in the longitudinal direction X.

[0054] The lower part 81a is fastened to the folded-back piece 32a of the battery assembly 3 with bolts 11. A pair of outer ribs 81d are respectively fastened to the first side wall 25 and the second side wall 26 with bolts 12.

[0055] The standing wall part 6 is fastened to the cover 2B with rivets 15 (see FIGS. 1 and 3), and extends downward from the inner surface of the top wall 24. For convenience, FIG. 3 shows the state in which the standing wall part 6 is disassembled from the cover 2B, and shows the arrangement relationship between the standing wall part 6, the back plate 81, and the sensor holder 9 in the assembled state of the battery module 1.

[0056] The standing wall part 6 is in a flat plate shape extending in the width direction Y and the height direction Z. One of the surfaces of the standing wall part 6 is the opposing surface 61 facing the fan 5, and the other of the surfaces is the back surface facing the battery assembly 3 and covering the back plate 81. A flange 62 into which the rivet 15 (see FIG. 3) is inserted is provided at the upper edge of the standing wall part 6. When viewed from one side in the longitudinal direction X, the opposing surface 61 is rectangular.

[0057] The standing wall part 6 is in a V shape inclined so as to move away from the fan 5 as it extends from the center in the width direction Y toward both outer sides in a plan view. The inner rib 81c is close to and faces the back surface of the standing wall part 6 with a slight clearance in the longitudinal direction X. Both side edges of the standing wall part 6 in the width direction Y are located inside the outer rib 81d in the width direction Y and on the other side of the edge of the outer rib 81d in the longitudinal direction X. The clearance between both side edges of the standing wall part 6 and the outer rib 81d serves as the lateral outlet 80b of the exhaust passage 80.

[0058] When viewed from one side in the longitudinal direction X, the standing wall part 6 completely covers the inlet 80a. In other words, the lower edge of the opposing surface 61 extends in the width direction Y below the lower edge of the inlet 80a. The lower edge of the opposing surface 61 is located above the bottom wall 23. The clearance between the lower edge of the opposing surface 61 and the bottom wall 23 serves as the lower outlet 80c of the exhaust passage 80. The lower outlet 80c is provided below the opposing surface 61, and the upper edge of the lower outlet 80c (the lower edge of the opposing surface 61) is located below the lower edge of the inlet 80a.

[0059] The gas flows into the exhaust passage 80 through the inlet 80a from the other side to the one side in the longitudinal direction X. The gas is guided to the inner rib 81c and collides with the back surface of the standing wall portion 6. A part of the gas changes its direction in the width direction Y, changes its direction again to the one side in the longitudinal direction X at the lateral outlet 80b, and flows out from the exhaust passage 80 (the space on the battery assembly 3 side with respect to the standing wall portion 6). That is, the gas flows in a shape like an S as viewed from the height direction Z. Also, a part of the gas changes its direction downward, changes its direction again to the one side in the longitudinal direction X at the lower outlet 80c, and flows out from the exhaust passage 80. That is, the gas flows in a shape like an S as viewed from the width direction Y.

[0060] In this way, the exhaust passage 80 is labyrinthine and guides the gas while making it meander. The gas and the spark collide with the exhaust duct 8 in the process of passing through the exhaust passage 80, and their kinetic energy and thermal energy are absorbed by the exhaust duct 8. Before the gas is discharged, a decrease in the gas temperature and the extinction of the spark are achieved.

[0061] The liquid leakage sensor 7 is disposed below the facing surface 61. In other words, the liquid leakage sensor 7 is disposed at the lower outlet 80c of the exhaust passage 80.

[0062] The liquid leakage sensor 7 includes a long detection cord 70 having flexibility. 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 and polyethylene, for example, and 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 adhesion of the liquid based on the change in resistance between the electrode wires.

[0063] Both ends of the detection code 70 are respectively 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. The liquid leakage sensor 7 includes a first sleeve 77 that protects the connection part between one end of the detection code 70 and the signal line 79a, and a second sleeve 78 that protects the connection part between the other end of the detection code 70 and the signal line 79a. 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 parts.

[0064] The detection code 70 includes a pair of horizontally extending parts 70a, a turn part 70b that connects the pair of horizontally extending parts 70a to each other, a first bending part 70c that connects one of the horizontally extending parts 70a to the first sleeve 77, and a second bending part 70d that connects the other horizontally extending part 70a to the second sleeve 78.

[0065] The pair of horizontally extending parts 70a extend in the width direction Y in a state of being in contact and adjacent to each other in the longitudinal direction X. The turn part 70b is bent in a hairpin shape and connects the other ends in the width direction of the pair of horizontally extending parts 70a. The turn part 70b corresponds to the central part of the entire long detection code 70. Among the liquid leakage sensors 7, in particular, the pair of horizontally extending parts 70a and the turn part 70b are arranged below the facing surface 61. The first sleeve 77 extends in the width direction Y above the pair of horizontally extending parts 70a. The second sleeve 78 extends in the width direction Y above the first sleeve 77.

[0066] The first bending part 70c extends upward from the end of the horizontally extending part 70a and is folded back to the other side in the width direction Y. The first bending part 70c connects the ends in the width direction Y of the horizontally extending part 70a and the first sleeve 77. The second bending part 70d extends upward from the end of the horizontally extending part 70a and is folded back to the other side in the width direction Y. The second bending part 70d connects the ends in the width direction Y of the horizontally extending part 70a and the second sleeve 78.

[0067] The sensor holder 9 is disposed between the battery assembly 3 and the fan 5, and holds the liquid leakage sensor 7 in the position and posture as described above. The sensor holder 9 is, for example, a resin molded product, thereby realizing a component having the following complex structure integrally.

[0068] The sensor holder 9 is generally plate-shaped. With the surface on the other side in the longitudinal direction X of the sensor holder 9 being overlapped with the surface on one side in the longitudinal direction X of the back plate 81, the sensor holder 9 is fastened to the back plate 81 with bolts 13. The liquid leakage sensor 7 is disposed on the surface on one side in the longitudinal direction X of the sensor holder 9.

[0069] When viewed from one side in the longitudinal direction X, the sensor holder 9 is, for example, L-shaped. The sensor holder 9 has a cord holding portion 91 extending in the width direction Y on the lower side, and a wiring holding portion 92 extending upward from the other side in the width direction Y of the cord holding portion 91. The cord holding portion 91 is located below the inlet 80a and is overlapped with the lower portion 81a of the back plate 81. The wiring holding portion 92 is located on the other side in the width direction Y with respect to the inlet 80a and is overlapped with the side portion 81b of the back plate 81.

[0070] The cord holding portion 91 holds the detection cord 70, the first sleeve 77, and the second sleeve 78 in fixed positions. The cord holding portion 91 is provided with a seating portion 91a, a positioning rib 91b, an outer peripheral portion 91c, a first clamp 91d, a second clamp 91e, and a pressing portion 91f.

[0071] The seating portion 91a protrudes from the lower edge of the cord holding portion 91 in the longitudinal direction X and extends in the width direction Y. The pair of laterally extending portions 70a are placed on the upper surface of the seating portion 91a. The positioning rib 91b is plate-shaped and protrudes upward from the other end in the width direction Y of the seating portion 91a, has a length in the width direction Y, and has a thickness in the longitudinal direction X. The detection cord 70 is assembled to the cord holding portion 91 such that the pair of laterally extending portions 70a sandwich the positioning rib 91b and the inner peripheral edge of the turning portion 70b abuts against the positioning rib 91b. Thereby, the detection cord 70 is widely arranged over the entire width direction Y on the seating portion 91a. Also, the liquid leakage sensor 7 can be easily assembled so as to have such an arrangement.

[0072] The outer peripheral portion 91c protrudes from the cord holding portion 91 to one side in the longitudinal direction X, is then bent downward, and is connected to the leading edge of the seating portion 91a. The outer peripheral portion 91c is reverse L-shaped when viewed in the width direction Y, and the pair of laterally extending portions 70a are inserted therethrough. However, the width of the outer peripheral portion 91c is very narrow. Therefore, while the position and posture of the pair of laterally extending portions 70a are well constrained by the outer peripheral portion 91c, most of the pair of laterally extending portions 70a are exposed upward without being hidden by the outer peripheral portion 91c. In the present embodiment, the two outer peripheral portions 91c are arranged apart from each other in the width direction Y.

[0073] Both the first clamp 91d and the second clamp 91e are composed of a pair of upper and lower locking pieces that protrude from the cord holding portion 91 to one side in the longitudinal direction X. The first sleeve 77 is sandwiched between the locking pieces of the first clamp 91d. The second sleeve 78 is sandwiched between the locking pieces of the second clamp 91e. In order to prevent the sleeves from falling off, claws that protrude so as to approach each other are provided at the tips of the pair of locking pieces.

[0074] The first clamp 91d is disposed above the outer peripheral portion 91c. The second clamp 91e is disposed above the first clamp 91d. The first clamp 91d and the second clamp 91e are spaced apart in the width direction Y, and the outer surface of the lower locking piece of the second clamp 91e is located below the outer surface of the upper locking piece of the first clamp 91d. With this arrangement, the vertical distance between the first sleeve 77 and the second sleeve 78 can be minimized as much as possible, and the liquid leakage sensor 7 can be handled in a compact manner.

[0075] The first sleeve 77 is supported not only by the restraint of the first clamp 91d but also by the outer surfaces of the pair of outer peripheral portions 91c and the outer surface of the lower locking piece of the second clamp 91e, and is stably held in a posture extending in the width direction Y. The second sleeve 78 is held not only by the second clamp 91e but also is placed on the outer surface of the upper locking piece of the first clamp 91d, and is stably held in a posture extending in the width direction Y. The pressing portion 91f protrudes in the longitudinal direction X from one end edge in the width direction Y of the cord holding portion 91. The pressing portion 91f is in an inverted L shape and holds the second curved portion 70d in a bent state. The pressing portion 91f contributes to the horizontal holding of the second sleeve 78.

[0076] The wiring holding portion 92 holds the signal lines 79a, 79b in a fixed position. The signal lines 79a, 79b extend together in the height direction Z on the wiring holding portion 92. The signal lines 79a, 79b are connected to the first sleeve 77 and the second sleeve 78 at the lower end portion of the wiring holding portion 92, and extend from above the upper end of the wiring holding portion 92 to the other side in the longitudinal direction X.

[0077] The wiring holding portion 92 is provided with a plurality of wiring hooks 92a spaced apart in the height direction Z. The wiring hook 92a protrudes from the wiring holding portion 92 to one side in the longitudinal direction X and is then bent in the width direction Y. The signal lines 79a, 79b are locked to such hook-shaped wiring hooks 92a, and thereby are stably held in a posture extending linearly in the height direction Z.

[0078] Note that in the battery module 1, a cable 19 for connecting the battery assembly 3 and the second circuit unit 4B may be provided. A cable tunnel 93 for passing such a cable 19 may be provided at the end and the lower end in the width direction of the sensor holder 9. Since the cable 19 does not have to pass through the labyrinthine exhaust passage 80, the cable laying work becomes easier.

[0079] The seating portion 91a is supported by the inner surface of the bottom wall 23. The detection code 70, the first sleeve 77, and the second sleeve 78 are disposed below the standing wall portion 6. The detection code 70 is located below the lower end of the fan 5.

[0080] The pair of laterally extending portions 70a face the second circuit unit 4B in the longitudinal direction X. One edge in the longitudinal direction of the pair of laterally extending portions 70a is located on one side in the longitudinal direction X with respect to both the first sleeve 77 and the second sleeve 78. In the present embodiment, one edge in the longitudinal direction of the pair of laterally extending portions 70a is recessed on the other side in the longitudinal direction X with respect to the fan 5.

[0081] The lower end portion of the standing wall portion 6 is inclined so as to move away from the fan 5 downward (that is, toward the other side in the longitudinal direction X). The opposing surface 61 may be inclined in this way. In the present embodiment, the opposing surface 61 is not inclined in the longitudinal direction X, and the standing wall portion 6 has a pair of tabs 63 protruding from the lower edge of the opposing surface 61. These tabs 63 are inclined in the longitudinal direction X.

[0082] In the present embodiment, the opposing surface 61 is V-shaped in plan view, the central portion in the width direction Y is closer to the fan 5, and both end portions in the width direction Y are farther from the fan 5. On the other hand, the laterally extending portion 70a extends linearly in the width direction Y and is not inclined in the height direction Z or the longitudinal direction X. Both end portions of the opposing surface 61 are located directly above the pair of laterally extending portions 70a, while the central portion of the opposing surface 61 is located on one side in the longitudinal direction X with respect to the pair of laterally extending portions 70a. Therefore, the pair of tabs 63 are provided at the central portion of the opposing surface 61, and the lower end of the tab 63 is located directly above the pair of laterally extending portions 70a. Thereby, the laterally extending portion 70a overlaps with the lower edge of the opposing surface 61 or the lower edge of the tab 63 in the vertical direction over the entire width direction Y.

[0083] The standing wall portion 6 can be manufactured by press working of sheet metal. The opposing surface 61 is bent into a V shape. By arranging the pair of tabs 63 at intervals at the width center of the opposing surface 61, the tabs 63 inclined with respect to the opposing surface 61 can be easily formed. Note that the tips of the pair of tabs 63 are brought closer to each other in the width direction Y by bending. Therefore, even if the pair of tabs 63 are arranged at intervals, there is almost no region where the laterally extending portion 70a does not overlap with the lower edge of the opposing surface 61 or the lower edge of the tab 63 in the vertical direction.

[0084] In the battery module 1 configured as described above, when the fan 5 operates, air is blown out from the fan 5 and blown against the opposing surface 61 of the standing wall portion 6. The opposing surface 61 is V-shaped and inclined so as to be farther from the fan 5 from the center in the width direction toward both outer sides in plan view. For this reason, the air smoothly flows along the opposing surface 61 to the other side in the longitudinal direction X, and heat generating components such as the battery assembly 3 and the first circuit unit 4A can be cooled.

[0085] At this time, there is a possibility that the liquid rides on the air flow formed by the fan 5 and enters the interior from the outside of the exterior case 2 through the inlet 27.

[0086] When the air volume of the fan 5 is large, the liquid sucked into the fan 5 is strongly blown out together with the air from the fan 5, strongly blown against the opposing surface 61, and adheres to the opposing surface 61 as droplets. The droplets entrain the liquid adhering to the opposing surface 61 below, increase their size, and flow downward along the opposing surface 61 under their own weight. The liquid leakage sensor 7 is disposed below such an opposing surface 61. Therefore, the liquid leakage sensor 7 can favorably detect the droplets flowing down the opposing surface 61.

[0087] The pair of laterally extending portions 70a, the first sleeve 77, and the second sleeve 78 are arranged so as to be aligned in the height direction Z. The pair of laterally extending portions 70a protrude to one side in the longitudinal direction X with respect to the first sleeve 77 and the second sleeve 78. Therefore, even when the pair of laterally extending portions 70a are disposed below the first sleeve 77 and the second sleeve 78, it is easy to attach the droplets falling from the opposing surface 61 to the pair of laterally extending portions 70a.

[0088] The lower end portion of the standing wall portion 6 is inclined so as to move away from the fan 5 downward. For this reason, the droplets on the opposing surface 61 flow along the inclination away from the fan 5 at the lower end portion of the standing wall portion 6 and fall from the tip of the inclination. Even if there is a distance between the liquid leakage sensor 7 and the fan 5, it is possible to drop the liquid collected on the opposing surface 61 onto the liquid leakage sensor 7. Even when it is difficult to bring the liquid leakage sensor 7 close to the fan 5 due to the presence of the second circuit unit 4B or the like, the detection accuracy of liquid entry can be improved.

[0089] In the present embodiment, for guiding air, the opposing surface 61 is V-shaped, and at the central portion in the width direction Y, the opposing surface 61 is offset to one side in the longitudinal direction X from the liquid leakage sensor 7. In such a case, by providing the above-described inclination, it is beneficial because it is possible to achieve both an improvement in air-cooling performance and an improvement in the detection accuracy of liquid entry. Further, by providing a tab 63 at the central portion in the width direction Y and inclining the tab 63, this compatible effect is achieved by a simple structure.

[0090] On the one hand, when the air volume of the fan 5 is small, the liquid sucked into the fan 5 descends due to its own weight while flying in the air flow direction. Therefore, there is a possibility that the liquid does not adhere to the facing surface 61 as described above. However, the liquid leakage sensor 7 is disposed below the facing surface 61. Further, the liquid leakage sensor 7 is disposed below the fan 5. Therefore, the liquid blown out from the fan 5 can be directly blown onto the liquid leakage sensor 7, and the entry of the liquid can be detected well.

[0091] Thus, according to the battery module 1 according to this embodiment, regardless of the air volume of the fan, the entry of the liquid can be accurately detected.

[0092] The exhaust duct 8 has the above-mentioned vertical wall portion 6. The exhaust duct 8 is a member for forming an exhaust passage 80 that guides the gas discharged from the battery assembly 3. The exhaust duct 8 has not only the function of guiding the gas but also the function of receiving the liquid. The number of components of the battery module 1 can be reduced, and the peripheral structure of the liquid leakage sensor 7 becomes compact. In particular, the liquid leakage sensor 7 is disposed using the lower outlet 80c of the exhaust passage 80, in other words, the opening portion forming the labyrinth-shaped exhaust passage 80. Compared with the case of securing a dedicated space for disposing the liquid leakage sensor 7, the peripheral structure of the liquid leakage sensor 7 becomes compact.

[0093] Also, the battery module 1 is disposed between the battery assembly 3 and the fan 5 and includes a sensor holder 9 that holds the liquid leakage sensor 7. By providing a dedicated component for holding, the positioning and assembly of the liquid leakage sensor 7 become easy. When the exhaust duct 8 has the vertical wall portion 6 and the liquid leakage sensor 7 is disposed at the lower outlet 80c, at least a part of the member that holds the liquid leakage sensor 7 is accommodated in the exhaust passage 80. The exhaust duct 8 can be manufactured with materials and structures necessary for heat resistance and gas induction, and the sensor holder 9 can be manufactured with materials and structures necessary for holding the liquid leakage sensor 7.

[0094] Next, with reference to FIG. 11, the battery module 1 according to the second embodiment will be described centering on the differences from the first embodiment.

[0095] As shown in FIG. 11 , in this embodiment, the edge of the laterally extending portion of the liquid leakage sensor 7 is located on one side in the longitudinal direction X of the front face of the fan (the end face of the fan 5 on the other side in the longitudinal direction X). When the airflow rate of the fan 5 is small, some of the liquid may not fly from the fan 5 but may fall downward from the lower edge of the front face of the fan. In this embodiment, liquid droplets that fall directly from the fan 5 can be made to adhere to the liquid leakage sensor 7. This improves the accuracy of detecting liquid intrusion.

[0096] The laterally extending portion on the other side in the longitudinal direction X of the pair is set back from the front surface of the fan to the other side in the longitudinal direction X. In this case, droplets flying while falling from the fan 5 due to their own weight can be captured by the laterally extending portion on the other side.

[0097] Next, with reference to FIG. 12, a battery module 1 according to a third embodiment will be described, focusing on the differences from the first embodiment.

[0098] 12, in this embodiment, the battery module 1 includes a guide plate 10 that extends from the lower edge of the front face of the fan toward the leading edge of the seating portion. In this case, liquid droplets that have accumulated on the lower edge of the front face of the fan can be guided along the guide plate 10 and deposited on the laterally extending portion. As in the second embodiment, this improves the accuracy of detecting liquid intrusion when the airflow rate of the fan 5 is low.

[0099] Although the embodiment has been described above, the above configuration is merely an example and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0100] 1 Battery Module 2 outer case 2A base 2B Cover 2C End Plate 3 Battery Assembly 4A 1st circuit unit 4B Second circuit unit 5 Fans 6 Vertical wall 7 Leakage liquid sensor 8 Exhaust duct 9 Sensor holder 10 Guide plate 11 - 13 Bolts 15 Rivet 19 Cable 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 30 Battery cell 31 Cell holder 31a Accommodation part 32 Support plate 32a Folded-back piece 51 Fan frame 52 Bolt insertion hole 53 Impeller 59 Bolt 61 Opposite surface 62 Flange 63 Tab 70 Detection code 70a Horizontally extending part 70b Turning part 70c First bending part 70d Second bending part 77 First sleeve 78 Second sleeve 79a, 79b Signal lines 80 Exhaust passage 80a Inlet 80b Horizontal outlet 80c Lower outlet 81 Back plate 81a Lower part 81b Side part 81c Inner rib 81d Outer rib 91 Code holding part 91a Seating part 91b Positioning rib 91c Outer surrounding part 91d First clamp 91e Second clamp 91f Pressing part 92 Wiring holding part 92a Wiring hook 93 Cable tunnel 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 disposed between the battery assembly and the fan and having a facing surface facing the fan, a liquid leakage sensor disposed below the facing surface, A battery module comprising:

2. The liquid leakage sensor is disposed below the fan. The battery module according to Claim 1.

3. A lower end portion of the standing wall portion is inclined so as to move away from the fan as it goes downward. The battery module according to Claim 1 or 2.

4. The standing wall portion has a V-shape inclined so as to move away from the fan toward both outer sides from the center in the width direction in plan view. The battery module according to Claim 1 or 2.

5. Further comprising an exhaust duct forming an exhaust passage for guiding gas discharged from the battery assembly, The exhaust duct has the standing wall portion. The battery module according to Claim 1 or 2.

6. The exhaust passage guides the gas while meandering from a space on the battery assembly side with respect to the standing wall portion, through an outlet below a lower edge of the standing wall portion, to a space on the fan side with respect to the standing wall portion. The liquid leakage sensor is disposed at the outlet. The battery module according to Claim 5.

7. Further comprising a sensor holder disposed between the battery assembly and the fan and holding the liquid leakage sensor. The battery module according to Claim 1 or 2.

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