Battery case for vehicle

Abstract

The invention relates to a battery case for a vehicle. A battery case of a battery is provided with a lower case. A recess is formed near a corner on the rear side in the front-rear direction of the vehicle on the bottom plate of the lower case, and water can be stored in the recess in the lower case. Thus, in the battery case, the amount of water until the battery module is immersed in water can be increased, and in the battery case, immersion of the battery module in water can be suppressed compared with a case in which no recess is provided in the bottom plate.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery case for a vehicle. BACKGROUND

[0002] A battery pack provided to a floor of a vehicle is described in Japanese Patent Application Publication No. 2021-123227. A plurality of battery cells of the battery pack are arranged in a battery pack case, and the battery pack case has a lower case in which the plurality of battery cells are arranged and an upper case that insulates a space in which the battery cells are arranged in the lower case from the surroundings. In addition, the lower case of the battery pack case is fixed to the floor of the vehicle. SUMMARY

[0003] However, in a vehicle, the lower portion of the vehicle body in which the battery case is installed is sometimes splashed with or immersed in rainwater accumulated on a road. Therefore, rainwater easily adheres to the battery case, and the adhered rainwater (water) sometimes penetrates into the inside. In the battery case, since the water that penetrates into the inside is accumulated, there is a concern that the accumulated water adheres to the battery pack inside the battery case or to the battery cells inside the battery pack.

[0004] When the battery pack or the battery cells inside the battery pack are immersed in water, the battery performance is reduced. Therefore, from the viewpoint of suppressing the water in the battery case from adhering to the battery cells or the like or the battery cells or the like from being immersed in water, there is room for improvement.

[0005] The present application was completed in view of the above-described fact, and an object thereof is to provide a battery case for a vehicle that can suppress water that penetrates into the inside from adhering to battery cells or the like.

[0006] To achieve the above-described object, a battery case for a vehicle according to a first aspect includes a case main body that is an outer shape rectangular parallelepiped, that houses a battery module in which a plurality of battery cells are stacked, on an inner surface side of a floor in an internal space, and that has a recess that is open upward, formed at a corner of the inner surface side of the floor in the case main body.

[0007] In the battery case for a vehicle according to the first aspect, the battery module is housed in the internal space of the case main body that is the outer shape rectangular parallelepiped. The plurality of battery cells of the battery module are arranged on the inner surface side of the floor of the case main body by being stacked.

[0008] In the case main body, the recess that is open upward is formed at the corner of the inner surface side of the floor. Thus, in the case main body, a part of the water that penetrates into the inside and is accumulated on the floor can be stored in the recess formed in the floor, and in the case main body, when water penetrates into the inside, the battery module or the battery cells can be suppressed from being immersed in the penetrated water, as compared with a case in which the recess is not formed.

[0009] The second vehicle battery case is different from the first vehicle battery case in that the recess is formed in the vehicle rear side portion of the bottom plate.

[0010] In the second vehicle battery case, the recess is formed in the vehicle rear side portion of the bottom plate. Therefore, in the case where water accumulates on the bottom plate, the water is caused to enter the recess on the vehicle rear side of the bottom plate in the case main body, and the battery module or the battery cell can be effectively prevented from being immersed in the water.

[0011] The third vehicle battery case is different from the first or second vehicle battery case in that, in the case main body, a water amount detection portion for detecting an amount of water remaining on the bottom plate is provided on the front side in the vehicle front-rear direction.

[0012] In the third vehicle battery case, the water amount detection portion for detecting an amount of water remaining on the bottom plate is provided on the front side in the vehicle front-rear direction. Thus, it is possible to detect a case where water is immersed in the case main body, and it is possible to prevent the battery module or the battery cell from being immersed in the water.

[0013] According to the present application, by providing the recess in the rear side portion in the vehicle front-rear direction of the bottom plate, it is possible to accommodate a part of the water that is immersed in the recess, and thus the vehicle battery case has an effect of being able to prevent the water that is immersed from adhering to the battery module or the battery cell, or the battery module or the battery cell from being immersed in the water, as compared with a case where the recess is not provided. BRIEF DESCRIPTION OF DRAWINGS

[0014] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, wherein the same reference numerals in different drawings denote the same element, and wherein:

[0015] Figure 1 is a schematic configuration view of a battery according to the present embodiment.

[0016] Figure 2 is a plan view of a main portion of the rear side in the vehicle front-rear direction of the lower case.

[0017] Figure 3 is a perspective view of a main portion of the rear side in the vehicle front-rear direction of the lower case.

[0018] Figure 4 is a perspective view of a main portion of the front side in the vehicle front-rear direction of the lower case.

[0019] Figure 5 is a perspective view of a main portion of the front side in the vehicle front-rear direction of the lower case, as viewed from a different direction from Figure 4 . DETAILED DESCRIPTION

[0020] Hereinafter, a vehicle battery housing according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the vehicle battery housing is mounted on and used in a vehicle.

[0021] exist Figure 1 The schematic structure of the battery (battery pack) 10 of this embodiment is shown in a perspective view. It should be noted that in the figure, the arrow FR indicates the forward direction in the vehicle's longitudinal direction, the arrow RH indicates the right direction in the vehicle's width direction, and the arrow UP indicates the upward direction.

[0022] Battery 10 is used, for example, in vehicles equipped with an electric motor (electric motor) as a drive source for driving (illustration omitted), and outputs direct current that can be used to drive the electric motor. Examples of vehicles equipped with battery 10 include hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and battery electric vehicles (BEV).

[0023] like Figure 1 As shown, the battery 10 includes a battery housing 12, which serves as the battery casing and casing body for a vehicle in this embodiment, and a battery pack 14 housed within the battery housing 12. The battery housing 12 is generally rectangular in shape and is disposed on the lower side of the floor panel, which serves as the floor of the vehicle, and on the upper side of the bottom cover, and is mounted on the vehicle body (all figures omitted).

[0024] The battery housing 12 has an upper housing 20 and a lower housing 22, which face each other with the upper housing 20 on the top and the lower housing 22 on the bottom.

[0025] The lower housing 22 has a base plate 24 that is generally rectangular when viewed from above. Furthermore, a peripheral wall 26 is erected around the base plate 24, and a flange 28, whose upper part bends outward from the lower housing 22, is formed on the peripheral wall 26 approximately around its circumference. The lower housing 22 integrally forms the base plate 24, the peripheral wall 26, and the flange 28, and is formed in a generally rectangular tray shape (or basin shape).

[0026] Furthermore, the upper housing 20 includes a top plate 30 that is generally rectangular when viewed from above. Additionally, a peripheral wall 32 protrudes downwards around the top plate 30 in the upper housing 20, and a flange 34 is formed on the peripheral wall 32 at its front (lower) end, folding outwards approximately around its entire circumference. The upper housing 20 integrally comprises the top plate 30, the peripheral wall 32, and the flange 34.

[0027] The battery housing 12 is constructed such that the flange 34 of the upper housing 20 and the flange 28 of the lower housing 22 overlap facing each other. Furthermore, the battery housing 12 is assembled by fastening the flange 34 of the upper housing 20 and the flange 28 of the lower housing 22 with fastening members such as bolts and nuts, thereby sealing the internal space from the outside (figures omitted).

[0028] It should be noted that in the battery casing 12, the boundary between the top plate 30 and the peripheral wall 32 in the upper casing 20, and the boundary between the bottom plate 24 and the peripheral wall 26 in the lower casing 22 are chamfered, thereby bending the outer surface side.

[0029] In battery 10, a battery pack 14 is housed within the internal space of battery casing 12. At this time, the battery pack 14 is covered top and bottom by a bottom plate 24 and a top plate 30, and surrounded by peripheral walls 26 and 32. Battery casing 12 functions as the battery pack housing for housing the battery pack 14.

[0030] The battery pack 14 consists of one or more battery modules 16, in which multiple battery cells (not shown) are stacked. The battery housing 12 houses the multiple battery modules 16. It should be noted that the battery housing 12 is not limited to housing multiple battery modules; it can also be configured to house a single battery module 16.

[0031] In the battery 10 (battery pack 14), for example, multiple battery modules 16 are connected in series or parallel. Additionally, in the battery pack 14, an auxiliary device class 36 is configured together with the multiple battery modules 16. The auxiliary device class 36 includes various sensors and a controller (not shown) that controls the operation of the battery modules 16 and the battery cells contained within them based on information detected by the sensors. Thus, in the battery 10 (battery pack 14), a DC current of the required voltage is output during discharge, and the multiple battery cells of the battery modules 16 are charged individually by inputting the required DC current.

[0032] In the battery housing 12, a plurality of platform portions 18 are formed on the base plate 24 of the lower housing 22. The platform portions 18 are, for example, rectangular blocks (or plates), with their long sides pointing in the vehicle width direction, and are arranged at predetermined intervals in the vehicle's longitudinal direction.

[0033] Furthermore, in the lower housing 22, the portion of the base plate 24 between the platform portion 18 and the peripheral wall 26 (the periphery of the base plate 24) is a lower portion (deep bottom) 24B that is lower than the central portion, i.e., the upper surface 24A, of the base plate 24. The battery module 16 is placed on the platform portion 18 and arranged on the base plate 24 of the lower housing 22 within the battery housing 12.

[0034] Therefore, in the battery housing 12, the battery module 16 is arranged such that the platform portion 18 is raised relative to the upper surface 24A of the base plate 24. In addition, in the base plate 24 of the battery housing 12, the peripheral portion is a lower portion 24B relative to the upper surface 24A of the battery pack 14, thereby further lowering the peripheral portion relative to the lower surface of the battery pack 14.

[0035] On the other hand, the battery casing 12 is formed into a generally rectangular box shape, with corner portions 44 provided at the four corners. Of the four corner portions 44, the front side in the vehicle longitudinal direction and the right side in the vehicle width direction is corner portion 44RF, the front side in the vehicle longitudinal direction and the left side in the vehicle width direction is corner portion 44LF, the rear side in the vehicle longitudinal direction and the right side in the vehicle width direction is corner portion 44RB, and the rear side in the vehicle longitudinal direction and the left side in the vehicle width direction is corner portion 44LB.

[0036] On the lower housing 22 of the battery housing 12, a recess 40 is provided at a corner 44 of a portion of the base plate 24 as a volume-increasing portion. In addition, in the lower housing 22, a bead portion is provided at a portion of the corner 44 of the base plate 24 where the recess 40 is not provided, serving as a protrusion and a convex portion.

[0037] exist Figure 2 In the top view, the main part of the rear side of the lower housing 22 in the vehicle longitudinal direction is shown. Figure 3 In the diagram, a three-dimensional view is used to represent the main rear portion of the lower housing 22 in the vehicle's longitudinal direction. Additionally, in... Figure 4 In the diagram, the main front part of the lower housing 22 in the vehicle's longitudinal direction is shown in a three-dimensional view. Figure 5 In the middle, use from and Figure 4 The three-dimensional views, viewed from different angles, show the main front portion of the lower housing 22 in the vehicle's longitudinal direction. It should be noted that... Figure 3 This indicates that the corner 44RB is viewed from the upper right front side. Figure 4 This indicates that the corner 44RF is viewed from the upper left rear side. Figure 5 This indicates that the area around corner 44RF is viewed from the upper right front side.

[0038] like Figure 2 as well as Figure 3 As shown, a recess 40 is formed on the lower plate 24 of the lower housing 22 at a low position 24B on the rear side in the vehicle longitudinal direction. In the lower housing 22, the recess 40 is formed near corner 44RB and corner 44LB. It should be noted that the recess 40 near corner 44RB and the recess 40 near corner 44LB have the same structure. Hereinafter, the recess 40 near corner 44RB will be mainly described, and the description of the recess 40 near corner 44LB will be omitted.

[0039] The recess 40 is formed in the lower portion 24B of the base plate 24 as a groove (with a bottom) that opens upwards. The recess 40 extends from the corner 44RB side towards the front side in the vehicle's longitudinal direction and extends from the corner 44RB side towards the left side in the vehicle width direction. Thus, the recess 40 appears approximately L-shaped when viewed from above. In the lower housing 22, by forming the recess 40 on the base plate 24, the volume of the recess 40 is increased accordingly.

[0040] It should be noted that in the lower housing 22, a rib (not shown) is formed protruding from the lower surface of the base plate 24 by forming a recess 40. The rib corresponding to the recess 40 is formed in a roughly L-shape and protrudes from the lower surface. Therefore, the portion of the rib corresponding to the recess 40 extending in the vehicle width direction and the portion extending in the vehicle front-rear direction are formed as one piece. Thus, even with the recess 40 formed in the lower housing 22, it is possible to prevent the plate thickness from becoming thinner in the recess 40 portion, thereby preventing a decrease in strength.

[0041] like Figure 4 As shown, on the bottom plate 24 of the lower housing 22, a rib 60 is formed at the lower front portion 24B in the vehicle longitudinal direction, serving as a protrusion and a convex shape. In the lower housing 22, the rib 60 is formed near corner 44RF and corner 44LF. It should be noted that the basic structure of the rib 60 near corner 44RF and the rib 60 near corner 44LF is the same; therefore, the description of the rib 60 near corner 44RF will be mainly provided below, while the description of the rib 60 near corner 44LF will be omitted.

[0042] Rib 60 protrudes upward from the lower portion 24B of the base plate 24. Furthermore, rib 60 is formed such that it is positioned inside the vehicle width direction (left side in the vehicle width direction) from the corner 44RF side towards the rear side in the vehicle's longitudinal direction, and rib 60 is inclined relative to both the vehicle's longitudinal direction and the vehicle width direction. Therefore, in the lower housing 22, near the lower portion 24B of the base plate 24 on the front side in the vehicle's longitudinal direction, the volume corresponding to the volume of rib 60 is reduced.

[0043] On the other hand, within the lower housing 22 of the battery housing 12, a water detection sensor (water level detection sensor) 50, serving as a water quantity detection unit and a water detection unit, is disposed. For example... Figure 5 As shown, the water detection sensor 50 is disposed in the lower housing 22 on the front side in the vehicle's longitudinal direction. For example, the water detection sensor 50 is disposed near the rib 60 near the corner 44RF.

[0044] The water detection sensor 50 is disposed in the auxiliary equipment category 36 as one of the sensors disposed within the battery housing 12. The water detection sensor 50 has a pair of electrodes 54 protruding downward from the sensor body 52, and the pair of electrodes 54 are respectively disposed protruding from the sensor body 52 toward the lower part 24B of the base plate 24.

[0045] In the water detection sensor 50, the lengths of the two electrodes 54 are the same or one is longer than the other. For example, electrode 54A is longer than electrode 54B. Thus, in the water detection sensor 50, by immersing the front ends of electrodes 54A and 54B in water W, it is possible to detect the presence of water in the lower part 24B of the bottom plate 24 of the lower housing 22.

[0046] Next, the function of this embodiment will be explained.

[0047] The battery 10 includes a battery housing 12, which is composed of an upper housing 20 and a lower housing 22. Within the battery housing 12, a battery module 16, on which multiple battery cells are stacked, is disposed (fixed) on the lower housing 22 and covered by the upper housing 20. Thus, the battery 10 houses the battery module 16 (battery pack 14) within the battery housing 12.

[0048] In battery 10, multiple battery cells of battery module 16 are charged individually by inputting DC power of the required voltage. Additionally, battery 10 outputs DC power of the required voltage by charging the battery cells.

[0049] In such a battery 10, battery performance degrades when water W adheres to the battery cells or the battery module 16 with stacked battery cells, or when the battery cells or the battery module 16 with stacked battery cells are immersed in water W. Therefore, in order to suppress the degradation of battery performance, it is necessary to prevent water W from adhering to the battery module 16 or the battery module 16 from being immersed in water W.

[0050] The battery casing 12 of the battery 10 is mounted on the lower part of the vehicle body. During vehicle operation, rainwater accumulated on the road surface may splash onto the battery casing 12, or the battery casing 12 may be submerged in rainwater. When water W seeps into the battery casing 12, it accumulates on the bottom plate 24 of the lower casing 22.

[0051] In the lower housing 22, the periphery of the base plate 24 is a low-lying portion 24B, which is lower than the upper surface 24A on which the battery module 16 is mounted. Additionally, in the lower housing 22, a platform portion 18 is disposed on the upper surface 24A, and the battery module 16 is disposed on the platform portion 18.

[0052] Therefore, even if water W is immersed in the battery casing 12 in the battery 10, the water W will accumulate in the lower part 24B of the bottom plate 24, thus preventing water W from adhering to the battery module 16 or the battery module 16 from being immersed in water W.

[0053] On the other hand, such as Figure 2 as well as Figure 3 As shown, in the lower housing 22, a recess 40 is formed in the low portion 24B of the bottom plate 24, which increases the volume near the low portion 24B within the lower housing 22. Therefore, in the battery housing 12, compared to the case where the recess 40 is not formed in the low portion 24B, the amount of water up to the battery module 16 can be increased. Thus, even if water W enters the battery housing 12, it is possible to effectively prevent the water W from adhering to the battery module 16 or the battery module 16 from being immersed in water W.

[0054] Furthermore, in a vehicle, depending on the passengers' seating and luggage load, the rear side of the vehicle in the longitudinal direction is often lower than the front side. In the lower housing 22, by forming a recess 40 on the rear side in the longitudinal direction, it is possible to more effectively prevent water W from adhering to the battery module 16 or the battery module 16 from being immersed in water W.

[0055] Furthermore, in a vehicle, inertial forces are generated in the width direction due to steering. Therefore, in the lower housing 22, the amount of water near the left and right corners 44LB and 44RB tends to increase (varies greatly), but recesses 40 are formed near these corners 44LB and 44RB. As a result, in the battery housing 12, it is possible to more effectively prevent water W from adhering to the battery module 16 or the battery module 16 from being immersed in water W.

[0056] Furthermore, in a vehicle, during an emergency, the vehicle may be subjected to loads on its rear side in the longitudinal direction or its inner side in the vehicle width direction. In the lower housing 22, a rib corresponding to the approximately L-shaped recess 40 is formed. Therefore, in a vehicle emergency, even if the lower housing 22 is subjected to loads on its rear side in the longitudinal direction or its inner side in the vehicle width direction, deformation can be suppressed. Thus, the battery housing 12 can protect the battery module 16 during a vehicle emergency.

[0057] On the other hand, a water detection sensor 50 is disposed in the lower housing 22, facing the lower part 24B of the bottom plate 24 on the front side in the vehicle's longitudinal direction. In the water detection sensor 50, a pair of electrodes 54A and 54B are in contact with or immersed in water W, enabling the detection of water W entering the bottom plate 24. Therefore, even if water W seeps into the battery housing 12, detection by the water detection sensor 50 can prevent the battery 10 from being used while water W is attached to the battery module 16.

[0058] In a vehicle, deceleration generates an inertial force towards the front, acceleration generates an inertial force towards the rear, and steering generates an inertial force in the vehicle width direction. In the lower housing 22, if water W adheres to the lower part 24B, the water W flows (moves) according to the inertial force.

[0059] Therefore, by arranging a water detection sensor 50 on the front side of the battery housing 12 in the vehicle longitudinal direction where the recess 40 is not provided, water W can be efficiently detected by the water detection sensor 50 while the vehicle is in motion.

[0060] Furthermore, a rib 60 is formed on the lower housing 22 near the front corners 44RF and 44LF in the vehicle's longitudinal direction. A water detection sensor 50 is disposed near the corner 44RF where the rib 60 is formed. Thus, even if the amount of water W reaching the lower portion 24B near the corner 44RF in the battery housing 12 is small, the water detection sensor 50 can efficiently detect water intrusion.

[0061] Furthermore, in the lower housing 22, a rib 60 is provided near the corners 44RF and 44LF of the base plate 24. This rib 60 is inclined relative to the vehicle's longitudinal direction and the vehicle width direction. Thus, even if loads are input from the front or the outside in the vehicle width direction during an emergency, the battery housing 12 can protect the battery module 16 from these loads.

[0062] Thus, in the battery housing 12, a recess 40 is formed on the lower housing 22 near the rear corners 44LB and 44RB in the vehicle's longitudinal direction. As a result, compared to the case where the recess 40 is not formed, the immersion of the battery module 16 in water W can be suppressed in the battery housing 12.

[0063] Furthermore, in the battery housing 12, a rib 60 is formed on the lower housing 22 near the front corners 44LF and 44RF in the vehicle's longitudinal direction, and a water detection sensor 50 is disposed near the corner 44RF. Thus, the battery housing 12 can effectively detect the infiltration of water W, and can effectively suppress the charging and discharging of the battery module 16 while it is submerged in water.

[0064] Furthermore, in the battery housing 12, a rib is formed on the rear side of the lower housing 22 in the vehicle longitudinal direction, corresponding to the recess 40, and a rib 60 is formed on the front side in the vehicle longitudinal direction. Thus, the battery housing 12 can protect the battery module 16 from loads input from the surroundings during vehicle emergencies.

[0065] It should be noted that in the embodiment described above, a recess 40 is formed near the rear corners 44LB and 44RB in the vehicle's longitudinal direction. However, in addition to being formed near the corners 44LB and 44RB, the recess may also be formed in a generally straight line shape in the lower portion 24B between the corners 44LB and 44RB. Furthermore, in addition to being formed near the corners 44LB and 44RB, the recess may also be formed in a generally straight line shape from the corners 44LB and 44RB toward the front side in the vehicle's longitudinal direction in the lower portion 24B. This increases the amount of water until the battery module 16 is immersed in water, thus preventing the battery module 16 from being immersed in water W.

[0066] Furthermore, in the water detection sensor 50, the amount of water W that can be detected varies depending on the distance between the tip of the shorter electrode 54B and the upper surface of the lower portion 24B. Therefore, the length of the electrode 54B can also be set according to the amount of water W detected in the water detection sensor 50. Thus, in the battery housing 12, the water detection sensor 50 can be used as a water level detection sensor to detect whether the amount of water W has reached a preset amount.

[0067] In this embodiment, a water detection sensor 50 is disposed near corner 44RF. However, the water detection sensor 50 may also be disposed near corner 44LF, or between corner 44LF and corner 44RF (the middle part in the vehicle width direction).

Claims

1. A battery case for a vehicle, wherein the battery case for the vehicle includes a case main body that is an outer shape of a rectangular parallelepiped, and that houses a battery module in which a plurality of battery cells are laminated, placed on an inner surface side of a floor, in the case main body, a recess that is open upward is formed at a corner portion on the inner surface side of the floor.

2. The battery case for the vehicle according to claim 1, wherein the recess is formed at a portion on a rear side of the vehicle of the floor.

3. The battery case for the vehicle according to claim 1, wherein in the case main body, a water amount detection portion for detecting an amount of water remaining on the floor is provided at a front side in a vehicle front-rear direction.

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