Cooling structure for vehicle battery

Abstract

To provide a cooling structure for a vehicle battery that extends a battery life by preventing deterioration due to temperature rise of a battery module, suppresses temperature variation among the plurality of battery modules to avoid output restrictions, and enables the battery to be fully used.SOLUTION: A cooling structure for a vehicle battery includes: a battery pack that houses multiple battery modules arranged along a vehicle front-rear direction; a blow-in port to which traveling wind blows; and a water spray mechanism that has multiple spray ports along the vehicle front-rear direction in a traveling wind path above the battery pack and sprays cooling water from the spray ports toward the battery pack. The water spray mechanism sprays more cooling water at the spray ports located on a rear side in the vehicle front-rear direction than at the spray ports located further forward.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, in vehicles equipped with a high-voltage battery as a power source, the temperature rise of the battery module during charging and discharging is relatively significant, so cooling means is usually provided to avoid deterioration due to temperature rise. All-solid-state batteries are relatively heat-resistant among batteries, so it is desirable to perform air cooling using the running wind, which is effective in terms of weight reduction and cost reduction, without relying on relatively strong cooling capacity such as water cooling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5494584 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional air cooling using the wind generated by traveling as described in Patent Document 1, the temperature of the wind cannot be controlled, so when the outside air temperature is high, it is not possible to ensure a low air cooling temperature, and there is a possibility that the battery modules cannot be sufficiently cooled. In addition, in many cases, the battery modules located at the front are easily cooled because they are directly hit by the wind generated by traveling, but the battery modules located at the rear are difficult to cool because they are hit by wind warmed by the battery modules further forward. As a result, the battery modules that are difficult to cool are easily deteriorated and the battery life is shortened. In addition, this causes temperature variations between multiple battery modules, making it impossible to use up the battery due to output restrictions.

[0005] The present invention has been proposed to address such circumstances, and aims to provide a cooling structure for a vehicle battery that extends the battery life by preventing deterioration due to temperature rise in the battery module, suppresses temperature variation among multiple battery modules to avoid output restrictions, and enables the battery to be fully used. [Means for solving the problem]

[0006] The present invention is a cooling structure for a vehicle battery, comprising a battery pack which houses a number of battery modules arranged along the fore-and-aft direction of the vehicle, an inlet into which wind from traveling blows, and a water spray mechanism which has a number of spray nozzles along the fore-and-aft direction of the vehicle in a traveling wind path above the battery pack and sprays cooling water from the spray nozzles toward the battery pack, wherein the water spray mechanism sprays more cooling water from the spray nozzle located rearward in the fore-and-aft direction of the vehicle than from the spray nozzle located further forward. Effect of the Invention

[0007] According to the present invention, it is possible to provide a cooling structure for a vehicle battery that extends the battery life by preventing deterioration due to temperature rise of the battery module, suppresses temperature variation among multiple battery modules to avoid output restrictions, and enables the battery to be fully used. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic side view showing a part of a vehicle equipped with a battery cooling structure of a first embodiment. [Diagram 2] FIG. 2 is a schematic side view for explaining an example of a battery cooling structure according to the first embodiment. [Diagram 3] 5 is a schematic side view for explaining another example of the battery cooling structure of the first embodiment. FIG. [Figure 4] FIG. 11 is a schematic side view for explaining an example of a battery cooling structure according to a second embodiment. [Diagram 5]FIG. 11 is a schematic side view for explaining an example of a battery cooling structure according to a third embodiment. [Figure 6] FIG. 11 is a perspective view showing a cooling fin included in the example of the battery cooling structure of the third embodiment. [Figure 7] 13 is a schematic diagram showing a control mechanism for controlling the amount of cooling water sprayed in a battery cooling structure of a fourth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In each drawing, the description of the same configuration will be omitted.

[0010] In each drawing, the direction indicated by the arrow X (hereinafter also referred to as the "X direction") is the forward direction in the vehicle fore-and-aft direction of the vehicle A (vehicle traveling direction), the direction indicated by the arrow Y (hereinafter also referred to as the "Y direction") is the rightward direction in the vehicle width direction (left-right direction) of the vehicle A, and the direction indicated by the arrow Z (hereinafter also referred to as the "Z direction") is the upward direction in the vertical direction (height direction) of the vehicle A. The opposite direction of the X direction is the backward direction in the vehicle fore-and-aft direction of the vehicle A (vehicle rearward direction), the opposite direction of the Y direction is the leftward direction in the vehicle width direction of the vehicle A, and the opposite direction of the Z direction is the downward direction in the vertical direction (height direction) of the vehicle A.

[0011] In each figure, the front side is the side closer to the X direction (more forward), and the rear side is the side closer to the opposite direction of the X direction (more rearward). The right side is the side closer to the Y direction (more rightward), and the left side is the side closer to the opposite direction of the Y direction (more leftward). The upper side is the side closer to the Z direction (more upward), and the lower side is the side closer to the opposite direction of the Z direction (more downward). In addition, front / rear, left / right, and up / down refer to front / rear in the vehicle front / rear direction of vehicle A, left / right in the vehicle width direction of vehicle A, and up / down in the vertical direction (height direction) of vehicle A. In addition, the front of vehicle A in the vehicle front / rear direction is simply referred to as the "front," and the rear of vehicle A in the vehicle front / rear direction is simply referred to as the "rear."

[0012] Among the multiple battery modules 11 included in the battery pack 9 described below, the battery module 11 located at the frontmost side in the vehicle front-rear direction is also referred to as the "front battery module 11." The battery module 11 adjacent to the front battery module 11 and located at the center side in the vehicle front-rear direction is also referred to as the "center battery module 11." The battery module 11 adjacent to the center battery module 11 and located at the rearmost side in the vehicle front-rear direction is also referred to as the "rear battery module 11."

[0013] First Embodiment First, a vehicle battery cooling structure (battery cooling structure) 1 according to a first embodiment of the present invention will be described. Fig. 1 shows a part of a vehicle A equipped with the battery cooling structure 1 according to the first embodiment. The vehicle A is an electric vehicle (EV) as an example of a vehicle powered by a battery. Note that the vehicle A is not limited to this, and may be any other vehicle having a battery as a power source, such as a hybrid vehicle or a fuel cell vehicle.

[0014] As shown in Fig. 1, seats 4 including a driver's seat are provided on a floor panel 31 inside a body 2 of a vehicle A, and a steering wheel 5 for driving and the like are provided in front of the seats 4. An engine, a motor, a heat exchanger (radiator), an electronic control unit (ECU), and the like (not shown) are provided inside a front portion 6 of the body 2. The body 2 also has a front grill opening (air inlet) 7 located at the very front and into which outside air (traveling wind) blows while the vehicle is traveling. Note that "traveling" refers to the state in which the vehicle A is traveling in the forward direction (vehicle travel direction, X direction).

[0015] 1 and 2, the vehicle body 2 is provided with an underfloor 32 below a floor panel 31, and the floor panel 31 and the underfloor 32 form a floor tunnel 3. In this floor tunnel 3, the space between the floor panel 31 and the underfloor 32 serves as a travel wind path through which the travel wind blown in through the front grill opening 7 passes.

[0016] The battery cooling structure 1 of the first embodiment includes such a front grill opening (air inlet) 7, a floor tunnel 3, and a battery pack (battery storage section) 9, as well as a water spray mechanism 40 provided with a plurality of water spray sections 42 each having a spray port 42a in a water flow path 41. The battery pack 9 has a housing (case) 90 configured with an upper housing section 91 consisting of a part of the underfloor section 32 and a lower housing section 92 consisting of a part of the bottom section (undercover) 8. The housing (case) 90 is formed in a box shape whose front-to-rear length is longer than its left-to-right length.

[0017] The battery pack 9 accommodates a junction box (JB) 10 at the frontmost side in the vehicle fore-and-aft direction within its housing 90, and accommodates multiple battery modules 11 of approximately identical configuration as a battery assembly behind the junction box 10.

[0018] The multiple battery modules 11 (battery assembly) are arranged at intervals from one another in the vehicle front-rear direction inside the housing 90. In the example of Fig. 1 and Fig. 2, three battery modules 11 having substantially the same configuration are arranged at intervals from one another in the vehicle front-rear direction inside the housing 90.

[0019] The junction box (JB) 10 has a junction box (JB) main body 10b housed in a junction box (JB) case 10a. The JB main body 10b is connected to the JB case 10a via a fixing member 10c. The JB main body 10b of the junction box 10 supplies high voltage to an inverter that drives a drive motor, a DC-DC converter that converts the high voltage to 12V and supplies it to various 12V-based electric components of the vehicle, an air conditioner, a heater, and the like (none of which are shown) provided in the vehicle body 2, and supplies charging power from a charger (not shown) to the battery cells 11b of the battery module 11 during charging.

[0020] Within the housing 90 of the battery pack 9, spaces (driving wind paths) 12 through which the driving wind can pass are provided between the junction box (JB) 10 and the front battery module 11, between the front battery module 11 and the central battery module 11, and between the central battery module 11 and the rear battery module 11.

[0021] 1 and 2, an upper housing portion 91 formed as part of the underfloor portion 32 has a plurality of protruding portions 91a formed along the vehicle front-rear direction, protruding into the floor tunnel 3. Each protruding portion 91a is formed at an upper position of each space portion 12. A plurality of ventilation holes (not shown) that allow ventilation are formed in an inclined surface 91b on the front side in the vehicle front-rear direction of each protruding portion 91a.

[0022] Furthermore, a plurality of protruding parts 92a protruding downward (toward the ground) are formed along the vehicle front-rear direction in the lower housing part 92 that is formed as part of the bottom part 8. Each protruding part 92a is formed at a lower position of each space part 12. The rear side of each protruding part 92a in the vehicle front-rear direction serves as an air vent 92b that allows ventilation.

[0023] One battery module 11 is configured by accommodating, for example, five battery cells 11b in a battery case 11a (see FIG. 7 below). The five battery cells 11b in one battery case 11a are arranged in parallel in the left-right direction (Y direction) approximately perpendicular to the main flow of the running wind at approximately constant intervals (approximately constant pitch).

[0024] In the housing 90, gaps that allow ventilation are formed between the housing 90 and the top, bottom, and front, rear, left, and right sides of each battery module 11, and each battery module 11 is housed in the housing 90 in this state. The battery case 11a has a structure that allows ventilation between the inside and outside. In one battery module 11, the five battery cells 11b are connected to the battery case 11a via the fixing members 11c on the side sides and the fixing members 11d on the bottom side. However, gaps that allow ventilation are formed between the top, bottom, and front, rear, left, and right sides of each battery cell 11b and the battery case 11a. In one battery module 11, the five battery cells 11b are housed in the battery case 11a in this state.

[0025] As described above, the three battery modules 11 are arranged at intervals in the vehicle front-rear direction inside the housing 90 of the battery pack 9, resulting in a total of 15 battery cells 11b arranged at intervals from one another. Therefore, all of the battery cells 11b in the battery pack 9 are able to be exposed to the wind generated by running.

[0026] The number of battery cells 11b arranged in the left-right direction in the battery module 11 is not limited to this, and may be either one or more. Also, the number of battery modules 11 arranged in the vehicle front-rear direction is not limited to this, and may be any number as long as it is more than one.

[0027] The battery cell 11b is, for example, an all-solid-state battery cell. The all-solid-state battery cell is made by mixing and solidifying powder of active material of the positive electrode and the negative electrode with powder of solid electrolyte, and is a battery capable of adjusting the temperature within the temperature range of the running wind. Note that the battery cell 11b is not limited to this, and may be a cell of another battery, for example, a lithium-ion battery cell.

[0028] As shown by the solid arrows in Figures 1 and 2, while vehicle A is traveling, the battery cooling structure 1 causes the traveling wind taken into vehicle A through the front grill opening (air inlet) 7 to flow into the battery pack 9 through the floor tunnel 3, and exhausts the traveling wind that has flowed through the battery pack 9 to the outside of vehicle A.

[0029] For example, when a traveling wind is blown from the outside into the front part 6 of the vehicle body 2 through the front grill opening (air inlet) 7, the traveling wind flows into the space 12 through a plurality of vent holes formed in the inclined surface 91b of the protruding part 91a of the battery pack 9 while flowing in the vehicle backward direction in the floor tunnel 3, as shown by the solid line arrow in FIG. 2, flows downward in the space 12, and is then discharged to the outside of the vehicle A through the vent hole 92b of the protruding part 92a. Although not shown by such a solid line arrow, the traveling wind that flows into the housing 90 through the plurality of vent holes of the inclined surface 91b flows in the vehicle backward direction between the battery case 11a and the battery cell 11b, or through gaps between adjacent battery cells 11b, and is then discharged to the outside of the vehicle A through the vent hole 92b. Note that, as shown by the solid line arrow in FIG. 2, the traveling wind that flows in the vehicle backward direction on the underside of the vehicle A may also flow into the battery pack 9 through the vent hole 92b.

[0030] In this way, the wind generated while traveling is taken in from the front side of the vehicle A, so that the battery module 11 located at the frontmost position in the battery pack 9 in the vehicle front-rear direction is cooled the most by the wind generated while traveling. On the other hand, the temperature of the battery modules 11 located further rearward is likely to increase due to heat transfer from the battery modules 11 in front of it. In addition, as the wind flows rearward, the temperature of the battery modules 11 also tends to increase due to heat transfer from the battery modules 11 in front of it. As a result, in the battery pack 9, the battery modules 11 located further rearward in the vehicle front-rear direction are less likely to be cooled by the wind generated while traveling.

[0031] From this viewpoint, it is necessary to suppress a further rise in the temperature of the battery modules 11 located on the rear side in the vehicle longitudinal direction and to reduce the temperature difference (temperature variation) between the battery modules 11 in the vehicle longitudinal direction. For this reason, the battery cooling structure 1 is provided with a water spray mechanism 40 having a plurality of spray nozzles 42a arranged along the vehicle longitudinal direction in the floor tunnel 3, which is a traveling wind path above the battery pack 9, and spraying cooling water from the spray nozzles 42a toward the battery pack 9. This battery cooling structure 1 is arranged so that the battery modules 11 located further rearward in the vehicle longitudinal direction are exposed to traveling wind containing a larger amount of cooling water, thereby enhancing the cooling effect of the traveling wind containing cooling water on the battery modules 11 located on the rear side.

[0032] Specifically, as shown in Figs. 1 and 2, the battery cooling structure 1 is provided with a water spray mechanism 40 on a floor panel 31 constituting an upper portion of a floor tunnel 3, which is a traveling air path. The water spray mechanism 40 has a water flow path 41 through which cooling water flows, and a plurality of water spray units 42 that spray the cooling water into the floor tunnel 3. The water flow path 41 is connected to a tank (not shown) that stores the cooling water, and a pump (not shown) that flows the cooling water in the tank into the water flow path 41. The plurality of water spray units 42 are provided along the vehicle front-rear direction of the water spray mechanism 40. One water spray unit 42 has a spray nozzle 42a that sprays the cooling water, and an opening / closing mechanism (not shown) that opens and closes the spray nozzle 42a.

[0033] When the pump (not shown) is operated, it circulates the cooling water in the tank (not shown) into the water flow path 41. The cooling water is sprayed from the spray nozzle 42a of the water spray unit 42 in the form of, for example, water droplets or mist while circulating through the water flow path 41. The pump is, for example, a water pump, but is not limited to this and may be any pump. The cooling water is, for example, a mixture of water and A / C (Air / Compressor) drainage water, but is not limited to this and may be other liquids, for example, simply water. During the period (summer) when it is particularly necessary to lower the temperature of the traveling wind, the use of the A / C increases due to the use of the vehicle air conditioner (not shown), and it is assumed that the amount of A / C drainage increases. For this reason, it is particularly preferable to use water as the cooling water.

[0034] When cooling water is sprayed in the form of droplets or mist from the spray nozzle 42a of the water spray mechanism 40 in the floor tunnel 3, a running wind containing the sprayed cooling water (moisture) flows in the floor tunnel 3. The temperature of the running wind containing the cooling water (moisture) is lower than the temperature of the simple running wind not containing the cooling water. In addition, in the portion where the running wind containing the cooling water hits (the outer surface of the housing 90 of the battery pack 9 or the portion inside the housing 90 exchanging heat with the running wind), the cooling performance for the battery pack 9 is improved by the heat of vaporization when the attached cooling water (moisture) evaporates.

[0035] In the battery cooling structure 1, the battery pack 9 is exposed to the traveling wind containing such cooling water (moisture) and having a reduced temperature, and therefore a higher cooling effect can be obtained than when the traveling wind containing no cooling water (moisture) is exposed to the battery pack 9. As a result, in the battery cooling structure 1, the battery pack 9 is cooled further than when it is cooled by the traveling wind not containing cooling water (moisture), and the temperature (battery temperature) of the battery module 11 including the battery cells 11b is further reduced.

[0036] In the battery cooling structure 1, the water spray mechanism 40 sprays more cooling water at a location on the rear side in the vehicle longitudinal direction than at a location on the front side thereof. Thereby, in the battery cooling structure 1, the battery module 11 located rearward in the vehicle longitudinal direction is cooled by the running wind containing more cooling water and having a lower temperature. The water spray mechanism 40 in the example of FIG. 2 is configured to spray more cooling water from the upper spray port 42a to the battery module 11 located on the rear side in the vehicle longitudinal direction.

[0037] Specifically, the water spray mechanism 40 shown in FIG. 2 is provided with a water spray portion 42 having a spray port 42a, respectively, on the upper side of the junction box 10 located at the most front side in the battery pack 9, on the upper side of the front-side battery module 11, on the upper side of the center-side battery module 11, and on the upper side of the rear-side battery module 11 among the plurality of battery modules 11 arranged in the vehicle longitudinal direction. Here, let the spray amount of the cooling water per unit time at the spray port 42a of the water spray portion 42 located on the upper side of the junction box 10 be n0, and the spray amounts of the cooling water per unit time at the spray ports 42a of the water spray portions 42 located on the upper sides of the front-side, center-side, and rear-side battery modules 11 be n1, n2, and n3, respectively. At this time, the water spray mechanism 40 sets the spray amounts of the cooling water from the spray ports 42a of the respective water spray portions 42 so that, for example, the spray amount n0 and the spray amount n1 are the same value, and the spray amount increases as it becomes n1, n2, n3 (n0 = n1 < n2 < n3).

[0038] According to the battery cooling structure 1 of the first embodiment, the battery modules 11 located at the rear, which are less likely to be cooled by the traveling wind, are exposed to more traveling wind containing cooling water, thereby improving the cooling effect of the traveling wind containing cooling water on the battery modules 11 located at the rear, and therefore deterioration due to temperature rise of the battery modules 11 included in the battery pack 9 can be prevented. As a result, according to the battery cooling structure 1, the battery life of the battery pack 9 can be extended, and temperature variations between the battery modules 11 included in the battery pack 9 can be suppressed to avoid output restrictions, so that the battery can be used up in the battery pack 9.

[0039] In the battery cooling structure 1, the water spray mechanism 40 may have the configuration of the example of Fig. 3 instead of the example of Fig. 2. In the example of Fig. 3, the cooling water is sprayed from more spray ports 42a of the water spray unit 42 toward the battery module 11 located further rearward in the vehicle longitudinal direction. As a result, even in the example of Fig. 3, the battery module 11 located further rearward in the vehicle longitudinal direction is cooled by the traveling wind containing more cooling water, thereby enhancing the cooling effect of the traveling wind containing cooling water on the battery module 11 located at the rear.

[0040] In the example of Figure 3, the water spray mechanism 40 has one water spray section 42 on the upper side of the junction box 10 located at the frontmost position in the battery pack 9 and one on the upper side of the front battery module 11, two water spray sections 42 on the upper side of the central battery module 11, and four water spray sections 42 on the upper side of the rear battery module 11.

[0041] In this example, the spray amount n0 of the cooling water per unit time at the spray port 42a of the water spray part 42 located above the junction box 10, the spray amount n1 of the cooling water per unit time at the spray port 42a of one water spray part 42 located above the front battery module 11, the spray amount n2 of the cooling water per unit time at the spray port 42a of each water spray part 42 located above the central battery module 11, and the spray amount n3 of the cooling water per unit time at the spray port 42a of each water spray part 42 located above the rear battery module 11 are set to be the same as each other (n0 = n1 = n2 = n3). However, the present invention is not limited to this, and for example, n0 = n1 < n2 < n3 may be set as described above. The battery cooling structure 1 can obtain the same effects as those described above for the example of FIG. 2 even in such an example of FIG. 3.

[0042] <Second Embodiment> Next, a second embodiment of the present invention will be described. As shown in FIG. 4, the battery cooling structure 1A of the second embodiment is such that the materials of the upper housing part 91 and the lower housing part 92 constituting the housing 90 of the battery pack 9 are made different at a first location 911, 921 including the front side in the vehicle front-rear direction and a second location 912, 922 including the rear side in the vehicle front-rear direction, and the materials of the second location 912 of the upper housing part 91 and the second location 922 of the lower housing part 92 are made of materials having significantly higher thermal conductivity than the materials of the first location 911 of the upper housing part 91 and the first location 921 of the lower housing part 92.

[0043] Thereby, in the battery cooling structure 1A of the second embodiment, the cooling effect on the rear battery module 11 when the cooling water is sprayed by the water spray mechanism 40 is further enhanced. The battery cooling structure 1A of the second embodiment has the same configuration as the example of FIG. 2 of the first embodiment for other configurations. Note that the battery cooling structure 1A of the second embodiment may have the same configuration as the example of FIG. 3 of the first embodiment for other configurations.

[0044] In this battery cooling structure 1A, the material of the first location 911 including the front side of the upper housing part 91 in the vehicle front-rear direction is a non-thermally conductive material having a relatively low thermal conductivity, and the material of the second location 912 including the rear side of the upper housing part 91 in the vehicle front-rear direction is a thermally conductive material having a significantly higher thermal conductivity than the non-thermally conductive material. Similarly, the material of the first location 921 including the front side of the lower housing part 92 in the vehicle front-rear direction is a non-thermally conductive material having a relatively low thermal conductivity, and the material of the second location 922 including the rear side of the lower housing part 92 in the vehicle front-rear direction is a thermally conductive material having a significantly higher thermal conductivity than the non-thermally conductive material.

[0045] The non-thermally conductive material is not particularly limited, and may be, for example, a resin material such as ABS resin, etc. The thermally conductive material is not particularly limited as long as it has a thermal conductivity significantly higher than that of the non-thermally conductive material, and may be, for example, a metal material such as aluminum, an aluminum alloy, copper, a copper alloy, etc.

[0046] In the battery cooling structure 1A, the first locations 911, 921 in the housing 90 are made of such a non-thermal conductive material, and the second locations 912, 922 on the rear side are made of such a thermal conductive material. As a result, when cooling water is sprayed from the spray port 42a of the water spray mechanism 40 and the running wind containing the sprayed cooling water (moisture) and having a reduced temperature hits the battery pack 9, the second locations 912, 922 made of the thermal conductive material are cooled more quickly and to a lower temperature than the first locations 911, 921 made of the non-thermal conductive material by the running wind with a reduced temperature and by the heat of vaporization when the cooling water (moisture) attached to the battery pack 9 evaporates. As a result, the cooling effect on the rear battery module 11 in the second locations 912, 922 is further enhanced.

[0047] Thus, in the battery cooling structure 1A of the second embodiment, the water spray mechanism 40 cools the battery module 11 located on the rear side with the traveling wind containing a larger amount of sprayed cooling water, and the rear side of the housing 90 is made of a thermally conductive material, thereby further enhancing the cooling effect on the rear battery module 11. With such a battery cooling structure 1A, it is possible to more effectively prevent deterioration of the battery module 11 due to temperature rise, and to more effectively extend the battery life of the battery pack 9. At the same time, the battery cooling structure 1A can more effectively suppress temperature variations between the multiple battery modules 11. As a result, the battery cooling structure 1A can more reliably avoid output restrictions and use up the battery.

[0048] <Third embodiment> Next, a third embodiment of the present invention will be described. As shown in FIG. 5, the battery cooling structure 1B of the third embodiment is provided with cooling fins 13 made of a thermally conductive material in the space 12 (traveling wind path) between the battery modules 11 in the battery pack 9. Such cooling fins 13 can take in heat generated by the battery modules 11 (especially the battery cells 11b), and can prevent the battery modules 11 from becoming excessively hot. The battery cooling structure 1B of the third embodiment has the same configuration as the example of FIG. 2 of the first embodiment except for this. Note that the battery cooling structure 1B of the third embodiment may have the same configuration as the example of FIG. 3 of the first embodiment except for this.

[0049] 6, the cooling fin 13 includes a plurality of elongated fins 13a arranged in parallel at substantially regular intervals (at substantially regular pitches). The thermally conductive material constituting the cooling fin 13 (particularly the plurality of fins 13a) is not particularly limited, but may be, for example, a metal material such as aluminum, copper, iron, or an alloy containing these.

[0050] As shown in Fig. 5 and Fig. 6, in the battery cooling structure 1B, the cooling fins 13 are provided in the space 12 in the battery pack 9 so that the longitudinal direction of the multiple fins 13a coincides with the Z direction (the up-down direction (height direction) of the vehicle A) and the parallel direction of the multiple fins 13a coincides with the Y direction (the vehicle width direction (left-right direction) of the vehicle A). In the example of Fig. 5, the space 12 located further rearward in the vehicle longitudinal direction has cooling fins 13 with larger surface areas (heat transfer areas) provided therein. Specifically, the cooling fins 13 located further rearward in the vehicle longitudinal direction have larger areas of the fins 13a, thereby making the overall surface area (heat transfer area) larger, thereby improving the heat transfer performance.

[0051] Alternatively, instead of the example of Figure 5, for example, the cooling fins 13 located toward the rear in the vehicle's fore-and-aft direction may be configured so that the spacing (pitch) between adjacent fins 13a is smaller and the number of parallel fins 13a is greater, thereby increasing the overall surface area (heat transfer area) and further improving the heat transfer performance.

[0052] Normally, battery modules 11 located further rearward in the vehicle's longitudinal direction are less likely to be cooled by the wind while the vehicle is running, and therefore generate more heat. In the battery cooling structure 1B, the surface area (heat transfer area) of the cooling fins 13 provided in the space 12 located further rearward in the vehicle's longitudinal direction in the battery pack 9 is made larger, so that more heat generated from the battery modules 11 located further rearward can be taken into the cooling fins 13 and dissipated into the air. This makes it possible to prevent an excessive temperature rise in the battery modules 11 located rearward.

[0053] Thus, in the battery cooling structure 1B of the third embodiment, the cooling fins 13 are provided to further enhance the effect of suppressing the temperature rise of the battery module 11 located on the rear side, and the water spray mechanism 40 cools the battery module 11 located on the rear side with the traveling wind containing more cooling water. According to such a battery cooling structure 1B, it is possible to further prevent deterioration due to the temperature rise of the battery module 11 included in the battery pack 9, and the battery life of the battery pack 9 can be further extended. At the same time, the battery cooling structure 1B can further suppress the temperature variation among the multiple battery modules 11. As a result, according to the battery cooling structure 1B, it is possible to more reliably avoid the output limit and use up the battery.

[0054] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. In addition to the configurations of the battery cooling structures 1, 1A, and 1B of the first to third embodiments, the battery cooling structure 1C of the fourth embodiment includes a control unit 20 configured with the above-mentioned electronic control unit (ECU) and a battery temperature sensor 21, as shown in Fig. 7, for example, and controls the amount of spray from the spray nozzle 42a of each water sprayer 42.

[0055] 7, in the battery cooling structure 1C, a battery temperature sensor 21 is provided for each of the five battery cells 11b included in one battery module 11. Thus, a total of 15 battery temperature sensors 21 provided in the three battery modules 11 included in the battery pack 9 are shown in Fig. 7. The temperatures (°C) of the five battery cells 11b included in one battery module 11 are detected by the battery temperature sensors 21 provided in each battery cell 11b.

[0056] In the battery cooling structure 1C, the control unit 20 is connected via a bus to five battery temperature sensors 21 (i.e., a total of 15 battery temperature sensors 21) provided in each of the front, center, and rear battery modules 11 provided in the battery pack 9. The control unit 20 is also connected to each water spray unit 42 of the water spray mechanism 40 via a bus.

[0057] Data on the temperature of the battery cells 11b detected by the battery temperature sensor 21 (temperature data) is supplied to the control unit 20. The control unit 20 identifies the temperature of each of the three battery modules 11 included in the battery pack 9 based on the supplied temperature data. For example, when the control unit 20 receives temperature data of each battery cell 11b from the battery temperature sensors 21 installed in each of the five battery cells 11b included in one battery module 11, it identifies, for example, the average value of the temperature data as the temperature of that battery module 11.

[0058] The control unit 20 may specify the temperature of one battery module 11 by another value other than the average value of the five battery cells 11b. For example, when temperature data of each battery cell 11b is supplied from the battery temperature sensors 21 installed in each of the five battery cells 11b included in one battery module 11, the control unit 20 may specify the average value of the highest temperature of the battery cell 11b (maximum battery temperature) and the lowest temperature of the battery cell 11b (minimum battery temperature) as the temperature of the battery module 11.

[0059] Alternatively, for example, the temperatures of three arbitrarily selected battery cells 11b among the five battery cells 11b included in one battery module 11 may be detected by the battery temperature sensors 21 installed respectively. In this case, when the temperature data of the three battery cells 11b are supplied from the corresponding battery temperature sensors 21, the control unit 20 may specify the average value of the three temperature data as the temperature of the battery module 11.

[0060] Based on the (specified) temperatures of the front, center, and rear battery modules 11 included in the battery pack 9, the control unit 20 controls the spray amount per unit time of the cooling water from the spray port 42a provided in the water spray section 42 of the water spray mechanism 40.

[0061] In the battery cooling structure 1C, the water spray mechanism 40 sprays a larger amount of cooling water per unit time at a location on the rear side in the vehicle longitudinal direction than at a location on the front side. Moreover, in the battery cooling structure 1C, the control unit 20 sets the spray amount per unit time of the cooling water at the spray port 42a of the water spray section 42 provided above each of the front, center, and rear battery modules 11 based on the respective temperatures of the front, center, and rear battery modules 11 included in the battery pack 9, and controls each water spray section 42 to spray the cooling water at the set spray amount per unit time.

[0062] For example, when the temperature of a certain battery module 11 is at an arbitrary second temperature t2 (t1 < t2) rather than at an arbitrary first temperature t1, the control unit 20 controls the spray amount in the water spray section 42 to increase the spray amount per unit time from the spray port 42a provided above the battery module 11. In this case, for example, the temperature of the battery module 11 and the spray amount per unit time at the spray port 42a above it may be in a proportional relationship or a substantially proportional relationship.

[0063] Also, for example, when there is a battery module 11 having a temperature higher than a predetermined set temperature among the front, center, and rear battery modules 11 included in the battery pack 9, the control unit 20 may perform a process of further increasing the spray amount per unit time from the spray port 42a provided above the battery module 11. In this case, the control unit 20 may stop the process of further increasing this spray amount when the temperature of the battery module 11 becomes equal to or lower than this set temperature by the traveling wind including the sprayed cooling water.

[0064] In this way, in the battery cooling structure 1C of the fourth embodiment, the amount of cooling water sprayed from the spray nozzle 42a of the water spray unit 42 provided on the upper side of the battery module 11 is set based on the temperature of the battery module 11, so that the amount of cooling water used (spray amount) by the water spray mechanism 40 can be made more appropriate. As a result, in the battery cooling structure 1C, it is possible to suppress wasteful use of cooling water.

[0065] Although the first to fourth embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention includes design changes and the like that do not deviate from the gist of the present invention. In addition, the above-mentioned examples can be combined by utilizing each other's technologies as long as there are no particular contradictions or problems in the purpose, configuration, etc. [Explanation of symbols]

[0066] 1, 1A, 1B, 1C: battery cooling structure, 2: vehicle body, 3: floor tunnel, 4: seat, 5: handle, 6: front part, 7: front grill opening (air inlet), 8: bottom part (under cover), 9: battery pack (battery storage part), 10: junction box (JB), 10a: junction box (JB) case, 10b: junction box (JB) main body, 10c, 11c, 11d: fixing member, 11: battery module, 11 a: battery case, 11b: battery cell, 12: space (air path when traveling), 13: cooling fin, 13a: fin, 20: control unit, 21: battery temperature sensor, 31: floor panel, 32: underfloor, 40: water spray mechanism, 41: water flow path, 42: water spray unit, 42a: spray nozzle, 90: housing (case), 91: upper housing unit, 91a, 92a: protrusion, 91b: inclined surface, 92: lower housing unit, 92b: ventilation hole, 911, 921: first location, 912, 922: second location

Claims

1. A vehicle battery cooling structure, A battery pack that accommodates a plurality of battery modules arranged along a front-rear direction of the vehicle; An inlet through which the wind blows in while driving, a water spray mechanism that has a plurality of spray nozzles along a vehicle front-rear direction in a traveling wind path above the battery pack and sprays cooling water from the spray nozzles toward the battery pack; The water spray mechanism sprays more cooling water at the spray nozzle located on the rear side in the vehicle front-rear direction than at the spray nozzle located further forward. A vehicle battery cooling structure comprising:

2. The housing of the battery pack is formed of a thermally conductive material at a rear portion in the vehicle front-rear direction.

2. The vehicle battery cooling structure according to claim 1,

3. A cooling fin is provided in a traveling air path between the battery modules in the battery pack, The cooling fins located toward the rear in the vehicle front-rear direction have a larger surface area.

2. The vehicle battery cooling structure according to claim 1,

4. a battery temperature sensor that detects a temperature of a battery cell included in the battery module; a control unit that controls the amount of cooling water sprayed from the spray nozzle of the water spray mechanism based on the temperature detected by the battery temperature sensor.

4. The vehicle battery cooling structure according to claim 1, wherein the vehicle battery cooling structure is a cooling structure for a vehicle battery.

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