Cooling structure for vehicle battery

Abstract

The present invention addresses the problem of providing a cooling structure for a battery for a vehicle, which can prevent deterioration caused by a temperature rise in a battery module, thereby extending the life of the battery, and can suppress a temperature deviation between a plurality of battery modules, thereby avoiding a power limit, thereby sufficiently using the battery. A cooling structure for a vehicle battery includes: a battery pack in which a plurality of battery modules are arranged in a front-rear direction of a vehicle and housed; a blowing inlet through which the traveling wind is blown in; and a water spray mechanism having a plurality of spray nozzles along the front-rear direction of the vehicle in a traveling air path above the battery pack, and spraying cooling water from the spray nozzles to the battery pack. The water spraying mechanism sprays more cooling water at the spraying ports located on the rear side in the vehicle front-rear direction than the spraying ports located on the front side.

Description

Technical Field

[0001] The present invention relates to a cooling structure for a battery for a vehicle. Background Art

[0002] Currently, in vehicles equipped with high-voltage batteries as power sources, the temperature of the battery module rises significantly during charging and discharging, so a cooling unit is usually installed to prevent degradation caused by temperature rise. All-solid-state batteries, which are relatively heat-resistant among batteries, need to be air-cooled using the wind that is effective in reducing weight and cost, even without relying on strong cooling capabilities such as water cooling.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5494584 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the existing air cooling by running wind described in Patent Document 1, since the temperature of the running wind cannot be controlled, it is impossible to ensure a low air cooling temperature when the outside air temperature is high, and the battery module may not be fully cooled. In addition, in most cases, the battery module located on the front side is easy to cool because it is directly blown by the running wind, while the battery module located on the rear side is difficult to cool because it is blown by the wind heated by the battery module on the front side. As a result, the battery module that is difficult to cool is prone to deterioration and the battery life is shortened. In addition, since temperature deviations occur between multiple battery modules, the power limitation causes the battery to be unable to be fully used.

[0008] The present invention is proposed to address this situation, and its purpose is to provide a cooling structure for a vehicle battery, which can prevent degradation caused by temperature rise of the battery module to extend the battery life, and suppress temperature deviation between multiple battery modules to avoid power limitation, thereby fully utilizing the battery.

[0009] Technical solutions for solving technical problems

[0010] The present invention is a cooling structure for a battery for a vehicle, characterized in that it comprises: a battery pack, which arranges and stores a plurality of battery modules along the front-rear direction of the vehicle; an air blowing port, into which the running wind blows; and a water spray mechanism, which has a plurality of spray ports along the front-rear direction of the vehicle in the running wind path above the battery pack, and sprays cooling water from the spray ports to the battery pack. The water spray mechanism sprays more cooling water at the spray ports located at the rear side of the front-rear direction of the vehicle than at the spray ports located at the front side.

[0011] Effects of the Invention

[0012] According to the present invention, a cooling structure for a vehicle battery can be provided which can prevent degradation due to temperature rise of a battery module to extend the battery life, and suppress temperature variation among a plurality of battery modules to avoid power limitation, thereby fully utilizing the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic side view showing a portion of a vehicle equipped with the battery cooling structure of the first embodiment;

[0014] Figure 2 is a schematic side view for explaining an example of a battery cooling structure according to the first embodiment;

[0015] Figure 3 is a schematic side view for explaining another example of the battery cooling structure of the first embodiment;

[0016] Figure 4 is a schematic side view for explaining an example of a battery cooling structure according to a second embodiment;

[0017] Figure 5 is a schematic side view for explaining an example of a battery cooling structure according to a third embodiment;

[0018] Figure 6 is a perspective view showing a cooling fin included in an example of a battery cooling structure according to a third embodiment;

[0019] Figure 7 It is a schematic diagram showing a control mechanism for controlling the spray amount of cooling water in the battery cooling structure according to the fourth embodiment.

[0020] Explanation of symbols

[0021] 1, 1A, 1B, 1C: battery cooling structure; 2: vehicle body; 3: floor tunnel; 4: seat; 5: steering wheel; 6: front part; 7: front grille opening (blowing inlet); 8: bottom (bottom cover); 9: battery pack (battery storage); 10: junction box (JB); 10a: housing for junction box (JB); 10b: main body of junction box (JB); 10c, 11c, 11d: fixing parts; 11: battery module; 11a: battery box; 11b: battery unit; 12: air Part (travel wind path); 13: cooling fins; 13a: fins; 20: control unit; 21: battery temperature sensor; 31: bottom plate; 32: underfloor; 40: water spray mechanism; 41: water flow path; 42: water spray unit; 42a: spray port; 90: frame (shell); 91: upper frame; 91a, 92a: protrusions; 91b: inclined surface; 92: lower frame; 92b: vent; 911, 921: first part; 912, 922: second part. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present invention with reference to the accompanying drawings. In each of the drawings, descriptions of the same configurations are omitted.

[0023] In each figure, the direction indicated by the arrow X (hereinafter also referred to as the "X direction") is the front direction of the vehicle A in the vehicle front-rear direction (the vehicle travel direction), the direction indicated by the arrow Y (hereinafter also referred to as the "Y direction") is the right direction of the vehicle A in the vehicle width direction (left-right direction), and the direction indicated by the arrow Z (hereinafter also referred to as the "Z direction") is the upper direction of the vehicle A in the vertical direction (height direction). The opposite direction to the X direction is the rear direction of the vehicle A in the vehicle front-rear direction (the vehicle backward direction), the opposite direction to the Y direction is the left direction of the vehicle A in the vehicle width direction, and the opposite direction to the Z direction is the lower direction of the vehicle A in the vertical direction (height direction).

[0024] In each figure, the front side is the side closer to the X direction (the side closer to the front direction), and the rear side is the side closer to the opposite direction of the X direction (the side closer to the rear direction). The right side is the side closer to the Y direction (the side closer to the right direction), and the left side is the side closer to the opposite direction of the Y direction (the side closer to the left direction). The upper side is the side closer to the Z direction (the side closer to the upper direction), and the lower side is the side closer to the opposite direction of the Z direction (the side closer to the lower direction). In addition, front and rear, left and right, and up and down refer to the front and back of the vehicle A in the vehicle front and rear direction, the left and right in the vehicle width direction of the vehicle A, and the up and down direction (height direction) of the vehicle A. In addition, the front of the vehicle front and rear direction of the vehicle A is also simply referred to as the "front", and the rear of the vehicle A in the vehicle front and rear direction is also simply referred to as the "rear".

[0025] In addition, among the plurality of battery modules 11 included in the battery pack 9 described later, the battery module 11 located at the frontmost side in the vehicle front-rear direction is also referred to as the “front side battery module 11”. In addition, the battery module 11 adjacent to the front side battery module 11 and located at the center side in the vehicle front-rear direction is also referred to as the “center side battery module 11”. In addition, the battery module 11 adjacent to the center side battery module 11 and located at the rearmost side in the vehicle front-rear direction is also referred to as the “rear side battery module 11”.

[0026] <First Embodiment>

[0027] First, a vehicle battery cooling structure (battery cooling structure) 1 according to a first embodiment of the present invention will be described. Figure 1 A portion of a vehicle A equipped with the battery cooling structure 1 of the first embodiment is shown. As an example of a vehicle using a battery as a power source, the vehicle A is an electric vehicle (EV). It should be noted that the vehicle A is not limited thereto, and may be any other vehicle having a battery as a power source, such as a hybrid vehicle or a fuel cell vehicle.

[0028] like Figure 1 As shown, in the body 2 of the vehicle A, a seat 4 including a driver's seat is provided on the floor 31, and a steering wheel 5 for driving is provided further in front of the seat. In addition, an engine, an electric motor, a heat exchanger (radiator), an electronic control unit (ECU: Electronic Control Unit), etc., which are not shown, are provided in the front portion 6 of the vehicle body 2. In addition, the vehicle body 2 has a front grille opening (blowing inlet) 7 located at the frontmost portion thereof and into which the outside air (driving wind) blows during driving. It should be noted that "driving" means that the vehicle A is driving in the direction forward thereof (the vehicle's traveling direction, the X direction).

[0029] like Figure 1 and Figure 2 As shown, the vehicle body 2 is provided with a floor lower portion 32 below the floor plate 31, and the floor lower portion 32 and the floor lower portion 31 form a floor tunnel 3. In the floor tunnel 3, the space between the floor lower portion 31 and the floor lower portion 32 becomes a running wind path through which the running wind blown in through the front grille opening 7 passes.

[0030] The battery cooling structure 1 of the first embodiment includes such a front grill opening (blow inlet) 7, a floor duct 3, a battery pack (battery storage portion) 9, and a water spray mechanism 40 provided with a plurality of water spray portions 42 having spray ports 42a in a water flow path 41. In the battery pack 9, an upper frame portion 91 composed of a portion of the lower floor portion 32 and a lower frame portion 92 composed of a portion of the bottom (bottom cover) 8 constitute a frame (casing) 90. The frame (casing) 90 is formed in a box shape, and its length in the front-to-back direction is longer than its length in the left-to-right direction.

[0031] The battery pack 9 houses a junction box (JB) 10 at the frontmost side in the vehicle front-rear direction in a housing 90 thereof, and houses a plurality of battery modules 11 having substantially the same structure as a battery assembly further rearward of the junction box 10 .

[0032] The plurality of battery modules 11 (battery assembly) are arranged in a spaced relationship from one another in the front-rear direction of the vehicle within the housing 90. Figure 1 , Figure 2 In the example of FIG. 1 , three battery modules 11 having substantially the same structure are arranged in a frame 90 at intervals from each other in the front-rear direction of the vehicle.

[0033] The junction box (JB) 10 contains a junction box (JB) body 10b in a junction box (JB) housing 10a. The JB body 10b is connected to the JB housing 10a via a fixing member 10c. The JB body 10b of the junction box 10 supplies a high voltage to an inverter that drives a driving motor, a DCDC converter that converts the high voltage into 12V and supplies it to various 12V series electric products of the vehicle, an air conditioner, a heater, etc. (not shown) installed in the vehicle body 2, and supplies charging power from a charger (not shown) to the battery cell 11b of the battery module 11 during charging.

[0034] A space portion (traveling wind path) 12 through which traveling wind can pass is provided between the junction box (JB) 10 in the frame 90 of the battery pack 9 and the battery module 11 on the front side, between the battery module 11 on the front side and the battery module 11 on the center side, and between the battery module 11 on the center side and the battery module 11 on the rear side.

[0035] like Figure 1 and 2 As shown, a plurality of protrusions 91a protruding into the floor tunnel 3 are formed along the vehicle front-rear direction in the upper frame portion 91 formed by a portion of the lower floor portion 32. Each protrusion 91a is formed at an upper position of each space portion 12. A plurality of ventilation holes (not shown) for ventilation are formed on an inclined surface 91b on the front side in the vehicle front-rear direction of each protrusion 91a.

[0036] In addition, a plurality of protrusions 92a protruding downward (toward the ground) are formed along the vehicle front-rear direction on the lower frame portion 92 formed by a portion of the bottom 8. Each protrusion 92a is formed at a lower position of each space portion 12. The rear side of each protrusion 92a in the vehicle front-rear direction is a vent 92b that allows ventilation.

[0037] As an example, one battery module 11 contains five battery cells 11b in a battery box 11a (see below). Figure 7 The five battery cells 11b in one battery box 11a are spaced apart from each other at substantially constant intervals (substantially constant pitches) and arranged in parallel in the left-right direction (Y direction) substantially orthogonal to the main flow direction of the traveling wind.

[0038] In the frame 90, a ventilated gap is formed between the upper surface, bottom surface, front, rear, left and right sides of each battery module 11 and the frame 90, and each battery module 11 is stored in the frame 90 in this state. In addition, the battery box 11a is a structure that can be ventilated to the inside and outside. In addition, in one battery module 11, five battery cells 11b are connected to the battery box 11a through the fixing parts 11c on the side and the fixing parts 11d on the bottom. However, a ventilated gap is formed between the upper surface, bottom surface, front, rear, left and right sides of each battery cell 11b and the battery box 11a. In one battery module 11, five battery cells 11b are stored in the battery box 11a in this state.

[0039] As described above, the three battery modules 11 are arranged spaced apart from each other in the vehicle front-rear direction in the frame 90 of the battery pack 9, so that a total of 15 battery cells 11b are arranged spaced apart from each other. Therefore, the traveling wind can pass around all of these battery cells 11b in the battery pack 9.

[0040] It should be noted that the number of battery cells 11b arranged in the left-right direction in the battery module 11 is not limited to this, and can be any number of single or multiple. In addition, the number of battery modules 11 arranged in the front-rear direction of the vehicle is not limited to this, and can be any number as long as it is multiple.

[0041] As an example, the battery cell 11b is an all-solid-state battery cell. An all-solid-state battery cell is formed by mixing and solidifying active material powders of the positive and negative electrodes and solid electrolyte powders, and is a battery that can adjust the temperature within the temperature range of the driving wind. It should be noted that the battery cell 11b is not limited to this, and can also be other battery cells, such as a lithium-ion battery cell.

[0042] like Figure 1 and Figure 2As shown by the solid arrow, when vehicle A is traveling, the battery cooling structure 1 allows the traveling wind introduced into vehicle A through the front grille opening (blowing inlet) 7 to flow into the battery pack 9 through the floor channel 3, and the traveling wind flowing in the battery pack 9 is exhausted to the outside of vehicle A.

[0043] For example, when the running wind blows into the front portion 6 of the vehicle body 2 from the outside through the front grille opening (blowing inlet) 7, for example, Figure 2 As shown by the solid arrows, while the running wind flows in the floor duct 3 in the backward direction of the vehicle, it flows into the space portion 12 through the multiple vents formed on the inclined surface 91b of the protruding portion 91a in the battery pack 9, flows downward in the space portion 12, and is discharged to the outside of the vehicle A from the vent 92b of the protruding portion 92a. In addition, although not indicated by the solid arrows, the running wind that flows into the frame 90 through the multiple vents on the inclined surface 91b flows in the backward direction of the vehicle through the gaps between the battery box 11a and the battery cell 11b, and between adjacent battery cells 11b, and is discharged to the outside of the vehicle A from the vent 92b. Figure 2 As shown by the solid arrow in FIG. 9 , the traveling wind flowing under the vehicle A in the rearward direction of the vehicle may also flow into the battery pack 9 through the vent 92 b .

[0044] In this way, since the running wind is introduced from the front side of the vehicle A, the battery module 11 located at the frontmost position in the vehicle front-rear direction in the battery pack 9 is most easily cooled by the running wind. On the other hand, the temperature of the battery module 11 located further back is easily increased due to the heat transfer from the battery module 11 in front of it. In addition, as the running wind flows to the rear, its temperature is also easily increased due to the heat transfer from the battery module 11 on the front side. Therefore, in the battery pack 9, the battery module 11 located further back in the vehicle front-rear direction is more difficult to be cooled by the running wind.

[0045] From this point of view, it is necessary to suppress the further increase in the temperature of the battery module 11 located on the rear side in the front-rear direction of the vehicle, and reduce the temperature difference (temperature deviation) between the battery modules 11 in the front-rear direction of the vehicle. Therefore, the battery cooling structure 1 includes a water spray mechanism 40 in the floor duct 3, which is the running wind path above the battery pack 9. The water spray mechanism 40 has a plurality of spray ports 42a arranged in the front-rear direction of the vehicle, and sprays cooling water from the spray ports 42a to the battery pack 9. The battery cooling structure 1 allows the battery module 11 located further back in the front-rear direction of the vehicle to be blown by the running wind containing more cooling water, thereby further improving the cooling effect of the running wind containing cooling water on the battery module 11 located on the rear side.

[0046] Specifically, Figure 1 and Figure 2As shown, the battery cooling structure 1 is provided with a water spray mechanism 40 on the bottom plate 31 constituting the upper part of the bottom plate channel 3 which constitutes the running wind path. The water spray mechanism 40 has a water flow path 41 for cooling water to flow, and a plurality of water spray sections 42 for spraying cooling water in the bottom plate channel 3. The water flow path 41 is connected to a water tank (not shown) for storing cooling water and a pump (not shown) for directing the cooling water in the water tank to the water flow path 41. The plurality of water spray sections 42 are arranged along the front-rear direction of the vehicle of the water spray mechanism 40. A water spray section 42 includes a spray port 42a for spraying cooling water, and an opening and closing mechanism (not shown) for opening and closing the spray port 42a.

[0047] When the pump (not shown) is working, it circulates the cooling water in the water tank (not shown) into the water flow path 41. While the cooling water circulates in the water flow path 41, it is sprayed from the spray port 42a of the water spray section 42 in a state such as water droplets or mist (fog). As an example, the pump is a water pump, but is not limited to this, and can be any pump. As an example, the cooling water is obtained by mixing A / C (Air / Compressor) drainage with water, but is not limited to this, and can also be other liquids, such as pure water. In the period when the running wind temperature needs to be particularly lowered (summer), since the use of the vehicle air conditioner (not shown) increases the use of the A / C, it is estimated that the amount of A / C drainage will also increase. Therefore, as cooling water, it is particularly preferred to mix the A / C drainage with water.

[0048] In the floor duct 3, when cooling water is sprayed in the form of water drops or mist (fog) from the spray port 42a of the water spray mechanism 40, the running wind containing the sprayed cooling water (water) flows in the floor duct 3. The temperature of the running wind containing the cooling water (water) is lower than the temperature of the simple running wind that does not contain cooling water. In addition, in the part where the running wind containing cooling water blows (the outer surface of the frame 90 of the battery pack 9 or the heat exchange part with the running wind inside the frame 90), the cooling performance of the battery pack 9 is improved by the vaporization heat when the attached cooling water (water) evaporates.

[0049] In the battery cooling structure 1, since the running wind containing such cooling water (moisture) and having a lowered temperature blows toward the battery pack 9, a higher cooling effect can be obtained than when the running wind not containing cooling water (moisture) blows toward the battery pack 9. Thus, in the battery cooling structure 1, the battery pack 9 is cooled more sufficiently and the temperature of the battery module 11 including the battery cell 11b (battery temperature) is lower than when it is cooled by the running wind not containing cooling water (moisture).

[0050] In the battery cooling structure 1, the water spray mechanism 40 sprays more cooling water at the rear side of the vehicle in the longitudinal direction than at the front side. Therefore, in the battery cooling structure 1, the battery modules 11 located further back in the longitudinal direction of the vehicle are cooled more by the running wind containing more cooling water and at a lower temperature. Figure 2 The water spray mechanism 40 in the example is arranged so that the water spray mechanism 40 a sprays more cooling water from the spray port 42 a on the upper side thereof toward the battery module 11 located further rearward in the vehicle front-rear direction.

[0051] Specifically, Figure 2 The water spray mechanism 40 shown is provided with a water spray section 42, and the water spray section 42 has a spray port 42a on the upper side of the junction box 10 located on the frontmost side of the battery pack 9, and on the upper side of the battery module 11 on the front side, the upper side of the battery module 11 on the center side, and the upper side of the battery module 11 on the rear side among the plurality of battery modules 11 arranged in the front-rear direction of the vehicle. Here, the spray amount of cooling water per unit time of the spray port 42a of the water spray section 42 located on the upper side of the junction box 10 is set to n0, and the spray amount of cooling water per unit time of the spray port 42a of the water spray section 42 located on the upper side of the battery module 11 on the front side, the center side, and the rear side is set to n1, n2, and n3, respectively. At this time, the water spray mechanism 40 sets the spray amount of cooling water from the spray port 42a of each water spray section 42 so that, for example, the spray amount n0 and the spray amount n1 are equal, and the spray amount increases as the spray amount changes to n1, n2, and n3 (n0=n1 <n2<n3)。

[0052] According to the battery cooling structure 1 of the first embodiment, the battery modules 11 located further back in the front-rear direction of the vehicle can be blown with more running wind containing cooling water, thereby further improving the cooling effect of the running wind containing cooling water on the battery modules 11 located on the rear side, thereby preventing the battery modules 11 included in the battery pack 9 from being deteriorated due to the temperature rise. Therefore, according to the battery cooling structure 1, the battery life of the battery pack 9 can be extended, and the temperature deviation between the battery modules 11 included in the battery pack 9 can be suppressed, and output limitation can be avoided, so that the batteries in the battery pack 9 can be fully used.

[0053] It should be noted that in the battery cooling structure 1, the water spray mechanism 40 may include Figure 3 The example is composed of Figure 2 Example. Figure 3 In the example of FIG. 1 , cooling water is sprayed from more spray ports 42a of the water spray section 42 toward the battery module 11 located further rearward in the vehicle front-rear direction. Figure 3In the example, the battery module 11 located on the rear side in the vehicle front-rear direction can be cooled by the traveling wind containing more cooling water, thereby further improving the cooling effect of the traveling wind containing cooling water on the battery module 11 located on the rear side.

[0054] In Figure 3 In the example, the water spray mechanism 40 is provided with one water spray part 42 on the upper side and the front side of the junction box 10 located on the frontmost side in the battery pack 9, two water spray parts 42 on the upper side of the battery module 11 on the central side, and four water spray parts 42 on the upper side of the battery module 11 on the rear side.

[0055] It should be noted that in this example, the spray amount n0 of the cooling water per unit time in the spray port 42a of the water spray part 42 located on the upper side of the junction box 10, the spray amount n1 of the cooling water per unit time in the spray port 42a of one water spray part 42 located on the upper side of the battery module 11 on the front side, the spray amount n2 of the cooling water per unit time in the spray port 42a of each water spray part 42 located on the upper side of the battery module 11 on the central side, and the spray amount n3 of the cooling water per unit time in the spray port 42a of each water spray part 42 located on the upper side of the battery module 11 on the rear side are set to be equal to each other (n0 = n1 = n2 = n3), but it is not limited thereto. For example, as described above, it can also be set to n0 = n1 < n2 < n3. In Figure 3 In the example, the battery cooling structure 1 can also obtain the same effect as Figure 2 the above effect of the example.

[0056] <Second Embodiment>

[0057] The following describes the second embodiment of the present invention. As Figure 4 shown, in the battery cooling structure 1A of the second embodiment, the materials of the upper frame part 91 and the lower frame part 92 of the frame 90 constituting the battery pack 9 are different at the first parts 911, 921 including the front side in the vehicle front-rear direction and the second parts 912, 922 including the rear side in the vehicle front-rear direction, and the materials of the second parts 912 of the upper frame part 91 and the second parts 922 of the lower frame part 92 are set to have a significantly higher thermal conductivity than the materials of the first parts 911 of the upper frame part 91 and the first parts 921 of the lower frame part 92.

[0058] Thereby, in the battery cooling structure 1A of the second embodiment, when the cooling water is sprayed by the water spray mechanism 40, the cooling effect on the battery module 11 on the rear side is further improved. The battery cooling structure 1A of the second embodiment has the same structure as that of the first embodiment Figure 2It should be noted that the battery cooling structure 1A of the second embodiment may also be configured to be the same as that of the first embodiment except for the above configuration. Figure 3 The same composition as the example.

[0059] In the battery cooling structure 1A, the material of the first portion 911 on the front side in the vehicle front-rear direction including the upper frame portion 91 is a non-thermal conductive material having a relatively low thermal conductivity, and the material of the second portion 912 on the rear side in the vehicle front-rear direction including the upper frame portion 91 is a thermal conductive material having a thermal conductivity significantly higher than that of the non-thermal conductive material. Similarly, the material of the first portion 921 on the front side in the vehicle front-rear direction including the lower frame portion 92 is a non-thermal conductive material having a relatively low thermal conductivity, and the material of the second portion 922 on the rear side in the vehicle front-rear direction including the lower frame portion 92 is a thermal conductive material having a thermal conductivity significantly higher than that of the non-thermal conductive material.

[0060] The non-thermally conductive material is not particularly limited, and may be, for example, a resin material such as ABS resin. The thermally conductive material is not particularly limited as long as its thermal conductivity is significantly higher than that of the non-thermally conductive material, and may be, for example, a metal material such as aluminum, aluminum alloy, copper, or copper alloy.

[0061] In the battery cooling structure 1A, the first portions 911 and 921 in the frame 90 are made of the above-mentioned non-thermal conductive material, and the second portions 912 and 922 located further behind the non-thermal conductive material are made of the above-mentioned thermal conductive material. Thus, cooling water is sprayed from the spray port 42a of the water spray mechanism 40, and when the running wind containing the sprayed cooling water (water) and having a lowered temperature blows to the battery pack 9, the second portions 912 and 922 of the thermal conductive material are cooled more quickly and at a lower temperature than the first portions 911 and 921 of the non-thermal conductive material by the running wind with a lowered temperature and the heat of vaporization when the cooling water (water) attached to the battery pack 9 evaporates. As a result, the cooling effect on the battery module 11 located on the rear side in the second portions 912 and 922 is further improved.

[0062] Thus, in the battery cooling structure 1A of the second embodiment, the battery module 11 located on the rear side is cooled by the running wind containing a larger amount of cooling water sprayed by the water spray mechanism 40, and the cooling effect on the battery module 11 on the rear side is further improved by setting the rear side of the frame 90 as a thermally conductive material. According to this battery cooling structure 1A, the degradation caused by the temperature increase of the battery module 11 can be better prevented, and the battery life of the battery pack 9 can be better extended. At the same time, in the battery cooling structure 1A, the temperature deviation between the plurality of battery modules 11 can be further suppressed. As a result, according to the battery cooling structure 1A, the output limitation can be more reliably avoided and the battery can be fully used.

[0063] <Third Embodiment>

[0064] The third embodiment of the present invention is described below. Figure 5 As shown in FIG. 1 , in the battery cooling structure 1B of the third embodiment, cooling fins 13 made of a thermally conductive material are provided in the space 12 (travel wind path) between the battery modules 11 in the battery pack 9. Such cooling fins 13 can absorb the heat generated by the battery modules 11 (particularly the battery cells 11b), thereby preventing the battery modules 11 from overheating. The battery cooling structure 1B of the third embodiment has the same configuration as the first embodiment except for the above configuration. Figure 2 It should be noted that the battery cooling structure 1B of the third embodiment may also be configured to be the same as that of the first embodiment except for the above configuration. Figure 3 The same composition as the example.

[0065] For example, Figure 6 As shown, the plurality of elongated fins 13a of the cooling fin 13 are arranged at substantially constant intervals (substantially constant pitch). The thermally conductive material constituting the cooling fin 13 (particularly the plurality of fins 13a) is not particularly limited, and may be, for example, metal materials such as aluminum, copper, iron, or alloys thereof.

[0066] like Figure 5 and Figure 6 As shown, in the battery cooling structure 1B, in the battery pack 9, the cooling fins 13 are arranged in the space 12 so that the length direction of the plurality of fins 13a is consistent with the Z direction [the vertical direction (height direction) of the vehicle A], and the parallel direction of the plurality of fins 13a is consistent with the Y direction [the vehicle width direction (left-right direction) of the vehicle A]. Figure 5 In the example of FIG. 1 , a cooling fin 13 having a larger surface area (heat transfer area) is provided inside the space portion 12 located at the rear side in the front-rear direction of the vehicle. Specifically, the area of ​​each fin 13a is made larger as the cooling fin 13 is located at the rear side in the front-rear direction of the vehicle, thereby making the overall surface area (heat transfer area) larger, thereby further improving the heat transfer performance.

[0067] Or, instead of Figure 5 As an example, for example, the cooling fins 13 that are located further to the rear in the front-to-rear direction of the vehicle may have smaller intervals (pitch) between adjacent fins 13a, and a greater number of fins 13a arranged in parallel may be used, so that the overall surface area (heat transfer area) is larger, thereby further improving the heat transfer performance.

[0068] Generally, the battery modules 11 located further back in the vehicle front-to-back direction are more difficult to be cooled by the running wind, and thus generate more heat. In the battery cooling structure 1B, in the battery pack 9, the cooling fins 13 are arranged in the space portion 12 located further back in the vehicle front-to-back direction, and the surface area (heat transfer area) thereof is made larger, so that more heat generated from the battery modules 11 located further back can also enter the cooling fins 13 and be dissipated into the air. Thus, the temperature of the battery modules 11 located at the rear side can be prevented from excessively rising.

[0069] Thus, in the battery cooling structure 1B of the third embodiment, the cooling fins 13 are provided in order to further improve the effect of suppressing the temperature rise of the battery module 11 located on the rear side, and on this basis, the battery module 11 located on the rear side is cooled by the running wind containing more cooling water through the water spray mechanism 40. According to this battery cooling structure 1B, the degradation caused by the temperature rise of the battery module 11 possessed by the battery pack 9 can be better prevented, and the battery life of the battery pack 9 can be better extended. At the same time, in the battery cooling structure 1B, the temperature deviation between the plurality of battery modules 11 can be further suppressed. As a result, according to the battery cooling structure 1B, the output limitation can be more reliably avoided and the battery can be fully used.

[0070] <Fourth Embodiment>

[0071] The fourth embodiment of the present invention is described below. The battery cooling structure 1C of the fourth embodiment has the following features in addition to the configurations of the battery cooling structures 1, 1A and 1B of the first to third embodiments. Figure 7 As shown, the control unit 20 composed of the above-mentioned electronic control unit (ECU) and the battery temperature sensor 21 are further included to control the spray amount of the spray port 42a in each water spray unit 42.

[0072] like Figure 7 As shown, in the battery cooling structure 1C, a battery temperature sensor 21 is provided for each of the five battery cells 11b of one battery module 11. Figure 7 A total of 15 battery temperature sensors 21 are shown, which are provided in three battery modules 11 included in the battery pack 9. The temperatures (° C.) of the five battery cells 11 b included in one battery module 11 are detected by the battery temperature sensors 21 provided in the respective battery cells 11 b.

[0073] In the battery cooling structure 1C, the control unit 20 is connected to five battery temperature sensors 21 (i.e., a total of 15 battery temperature sensors 21) respectively provided in the battery modules 11 on the front side, the center side, and the rear side of the battery pack 9 through a bus. In addition, the control unit 20 is connected to each water spray unit 42 of the water spray mechanism 40 through a bus.

[0074] The data (temperature data) of the temperature of the battery cell 11b detected by the battery temperature sensor 21 is supplied to the control unit 20. The control unit 20 determines the respective temperatures of the three battery modules 11 included in the battery pack 9 based on the supplied temperature data. For example, when the temperature data of each battery cell 11b is supplied from the battery temperature sensor 21 provided in each of the five battery cells 11b included in one battery module 11, the control unit 20 determines the average value of each temperature data as the temperature of the battery module 11, for example.

[0075] It should be noted that the control unit 20 may not use the average value of the five battery cells 11b, but may use other values ​​to determine the temperature of one battery module 11. For example, when the temperature data of each battery cell 11b is provided from the battery temperature sensor 21 provided in each of the five battery cells 11b of one battery module 11, the control unit 20 may determine the average value of the temperature of the highest battery cell 11b (the highest battery temperature) and the temperature of the lowest battery cell 11b (the lowest battery temperature) as the temperature of the battery module 11.

[0076] Alternatively, for example, the temperatures of three battery cells 11b arbitrarily selected from the five battery cells 11b of one battery module 11 may be detected by the respectively provided battery temperature sensors 21. In this case, if the temperature data of the three battery cells 11b are provided from the corresponding battery temperature sensors 21, the control unit 20 may determine the average value of the three temperature data as the temperature of the battery module 11.

[0077] The control unit 20 controls the spray amount per unit time of the cooling water from the spray ports 42a of the water spray unit 42 in the water spray mechanism 40 according to the (determined) temperatures of the battery modules 11 at the front, center, and rear sides of the battery pack 9 .

[0078] In the battery cooling structure 1C, the water spray mechanism 40 sprays cooling water with a larger spray amount per unit time at a position on the rear side in the vehicle front-rear direction than at a position on the more front side. On this basis, in the battery cooling structure 1C, the control unit 20 sets the spray amount per unit time of the cooling water in the spray ports 42a of the water spray parts 42 provided on the upper sides of the front-side, center-side, and rear-side battery modules 11 of the battery pack 9 according to the temperatures of the front-side, center-side, and rear-side battery modules 11, and controls each water spray part 42 to spray the cooling water according to the set spray amount per unit time.

[0079] For example, the control unit 20 controls the spray amount of the water spray part 42 so that when the temperature of a certain battery module 11 is a second temperature t2 (t1 < t2) compared to the case of an arbitrary first temperature t1, the spray amount per unit time from the spray port 42a provided on the upper side of the battery module 11 is larger. In this case, for example, the temperature of the battery module 11 may be in a proportional relationship or approximately in a proportional relationship with the spray amount per unit time of the spray port 42a above it.

[0080] In addition, for example, when there is a battery module 11 having a temperature higher than a preset temperature among the front-side, center-side, and rear-side battery modules 11 of the battery pack 9, the control unit 20 may also perform a process of further increasing the spray amount per unit time from the spray port 42a provided on the upper side of the battery module 11. In this case, the control unit 20 may stop the process of further increasing the spray amount at the moment when the temperature of the battery module 11 becomes lower than the set temperature due to the traveling wind containing the sprayed cooling water.

[0081] In this way, in the battery cooling structure 1C of the fourth embodiment, the spray amount of the cooling water in the spray port 42a of the water spray part 42 provided on its upper side is set according to the temperature of the battery module 11, so that the amount of cooling water (spray amount) used in the water spray mechanism 40 can be made a more appropriate amount. As a result, wasteful use of the cooling water in the battery cooling structure 1C can be suppressed.

[0082] The first to fourth embodiments of the present invention have been described in detail above with reference to the drawings, but the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. In addition, in the above examples, as long as there is no particular contradiction or problem in terms of purpose and configuration, etc., the technologies of each other can be combined.

Claims

1. A cooling structure for a vehicle battery, characterized in that: include: A battery pack that arranges and houses multiple battery modules in the front-to-rear direction of the vehicle; A blowing port for the running wind to blow in; as well as, a water spray mechanism having a plurality of spray ports along the front-rear direction of the vehicle in a traveling wind path above the battery pack, and spraying cooling water toward the battery pack from the spray ports; The water spray mechanism sprays more cooling water at the spray port located at the rear side in the front-rear direction of the vehicle than at the spray port located at the front side.

2. The cooling structure of a vehicle battery according to claim 1, characterized in that: The battery pack frame is formed of a thermally conductive material at a rear portion thereof in the vehicle front-rear direction.

3. The cooling structure of a vehicle battery according to claim 1, characterized in that: Cooling fins are provided in the wind path between the battery modules in the battery pack. The cooling fins have a larger surface area as they are positioned more rearward in the vehicle front-rear direction.

4. The cooling structure for a vehicle battery according to any one of claims 1 to 3, characterized in that: include: A battery temperature sensor, which detects the temperature of a battery cell of the battery module; as well as, A control unit controls a spray amount of the cooling water sprayed from the spray port in the water spray mechanism according to the temperature detected by the battery temperature sensor.

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