In-vehicle battery protection structure

Abstract

To solve the problem in that: in a conventional protective construction of battery cell stacks, manufacturing cost and total weight increase as number of battery cell stacks increases.SOLUTION: A protective construction 11 of an on-vehicle battery 10 mainly comprises: a frame body 14 which fixes an on-vehicle battery 10 to a vehicle body; a protective frame 15 which is connected with the frame body 14 in a cross direction; and a stationary part 16 which is fixed to the protective frame 15 and hangs and supports the battery cell stack 13. A clearance hole 22 is formed in the protective frame 15 arranged at the approximately midship part of the battery cell stack 13. Due to this construction, a bolt part 16A of the stationary part 16 is moved, when impact force is applied by vehicle collision, within the clearance hole 22, the battery cell stack 13 stays in the original fixed position, so that the battery cell 21 is prevented from being broken.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a protection structure for in-vehicle batteries, and particularly to a protection structure for in-vehicle batteries that holds a battery stack suspended from a frame fixed to a vehicle body and protects the battery stack from vibrations during vehicle travel and impacts during vehicle collisions.

Background Art

[0002] As a protection structure for a conventional vehicle battery pack, for example, the protection structure described in Patent Document 1 is known.

[0003] The protection structure for a vehicle battery pack protects a vehicle battery pack composed of a plurality of battery stacks and the like, and includes a battery pack storage container portion in which the vehicle battery pack is stored. The battery pack storage container portion is composed of a storage container that stores the battery pack and each frame that supports the peripheral portion of the storage container.

[0004] The storage container is disposed in a storage space provided in the rear floor of the vehicle, and each of the above frames is connected to the vehicle body around the storage space. For example, four battery stacks are stored in a storage container formed in a substantially box shape. Each connection terminal of the battery stack is connected to a junction box or a BCU (Battery Control Unit), which is an electronic device, via electrical wiring.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to cope with the recent electrification of vehicles, higher output and higher capacity of vehicle batteries are required. And in order to achieve higher output and higher capacity of vehicle batteries, the number of battery stacks in which a plurality of battery cells are housed increases. As a result, the number of components such as end plates and restraint plates constituting the battery stack and the electrical wiring increase, resulting in an increase in manufacturing costs and an increase in the weight of the entire vehicle battery pack. In addition, there is a problem that the internal resistance of the battery pack increases due to the increase in electrical wiring.

[0007] In addition, although a plurality of battery stacks are fixed to the storage container, the storage container requires a skeletal structure for protecting the battery stack from the impact during a vehicle collision, resulting in an increase in the manufacturing cost and weight of the storage container.

[0008] On the other hand, as described above, in order to solve the problem of the increase in the number of battery stacks, it is conceivable to increase the number of battery cells housed in one battery stack. However, when the number of battery cells is increased, the overall length of the battery stack in the stacking direction of the battery cells becomes longer, and due to the vibration of the vehicle, particularly the vibration amplitude in the middle region of the battery stack becomes larger. As a result, the battery cells in the middle region of the battery stack may collide with peripheral components and the like due to the vibration and be damaged.

[0009] The present invention has been made in view of the above circumstances, and relates to a protection structure for an in-vehicle battery that holds a battery stack in a state of being suspended from a frame fixed to a vehicle body, and protects the battery stack from vibrations during vehicle travel and impacts during vehicle collisions.

Means for Solving the Problems

[0010] In a protection structure for an in-vehicle battery according to an embodiment of the present invention, the protection structure for an in-vehicle battery that fixes and protects an in-vehicle battery having a battery stack to a vehicle body includes a first frame that is connected to an upper side of a battery case in which the battery stack is housed and fixes the battery case to the vehicle body, a second frame that is disposed above the battery case and connected to the first frame, and a fixing portion that is fixed to the second frame and suspends and supports the battery stack. A plurality of electronic devices for electronically controlling the battery stack, and a device mounting bracket that extends in the longitudinal direction of the battery stack and is disposed above the battery stack. The second frame is disposed in a direction intersecting the longitudinal direction of the battery stack and is disposed at least at a substantially central portion in the longitudinal direction of the battery stack. The electronic device is fixed to the upper surface of the device mounting bracket so as to sandwich the second frame. It is characterized by this.

Effect of the Invention

[0011] In a protection structure for an in-vehicle battery according to an embodiment of the present invention, the fixing portion suspends and supports a substantially central portion in the longitudinal direction of the battery stack, thereby significantly reducing the vibration amplitude at the substantially central portion of the battery stack and preventing the battery cells from colliding with peripheral components or the like due to vibration and being damaged. Further, by increasing the number of battery cells in the battery stack, higher output and higher capacity of the in-vehicle battery are realized.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0013] Hereinafter, a protection structure 11 of an in-vehicle battery 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, the same reference numerals are generally used for the same members, and repeated descriptions are omitted. Also, the front-back direction of the paper indicates the front-back direction of the vehicle 12, the left-right direction of the paper indicates the vehicle width direction of the vehicle 12, and the up-down direction of the paper indicates the height direction of the vehicle 12.

[0014] FIG. 1 is a schematic diagram for explaining a vehicle 12 equipped with a protection structure 11 for an in-vehicle battery 10 according to the present embodiment. FIG. 2 is a perspective view for explaining the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIG. 3 is a top view for explaining a protection frame 15 of the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIGS. 4A to 4C are top views for explaining a fixing portion 16 of the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIG. 5 is a cross-sectional view for explaining the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIG. 6 is an enlarged cross-sectional view for explaining the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIG. 7 is a cross-sectional view for explaining the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. FIG. 8 is a schematic diagram for explaining the protection frame 15 at the time of a pole collision of the vehicle 12. FIG. 9 is a perspective view for explaining the protection structure 11 of the in-vehicle battery 10 according to the present embodiment. In FIGS. 2 to 8, for convenience of explanation, the BCU 31 and the junction box 32 are omitted from the illustration.

[0015] In vehicles 12 such as automobiles and trains, an in-vehicle battery 10 for supplying power to a motor and various electrical components is mounted. In the case of an automobile as the vehicle 12, in recent years, EV (Electrical Vehicle), HEV (Hybrid Electrical Vehicle), PHEV (Plug-in Hybrid Electrical Vehicle), etc. have become popular, and these vehicles 12 are also equipped with an in-vehicle battery 10 having a high power storage function.

[0016] First, the protection structure 11 of the in-vehicle battery 10 protects the in-vehicle battery 10 having a battery stack 13 from vibrations of the vehicle 12 and impacts at the time of a collision of the vehicle 12. As shown in FIG. 1, the in-vehicle battery 10 and its protection structure 11 are disposed, for example, in a storage space 12A below the rear floor at the rear of the vehicle 12, and the in-vehicle battery 10 is disposed such that its longitudinal direction coincides with the left-right direction of the vehicle 12. Note that the in-vehicle battery 10 and its protection structure 11 are not limited to being disposed in the storage space 12A below the rear floor, and may also be disposed in a storage space below a front floor where the driver's seat and the passenger seat of the vehicle 12 are disposed.

[0017] As shown in FIG. 2, the protection structure 11 of the in-vehicle battery 10 mainly includes a frame body frame 14 for fixing the in-vehicle battery 10 to the vehicle body, a protection frame 15 connected in an intersecting direction with the frame body frame 14, a fixing portion 16 fixed to the protection frame 15 and suspending and supporting the battery stack 13, a vibration-proof bracket 17 (see FIG. 5), an equipment mounting bracket 18, and a suspension bracket 24 (see FIG. 7). In this embodiment, the frame body frame 14 corresponds to the first frame described in the claims, and the protection frame 15 corresponds to the second frame described in the claims.

[0018] Further, the in-vehicle battery 10 mainly includes a battery stack 13 configured by stacking and serially connecting a plurality of battery cells 21 (see FIG. 5), a battery case 19 for housing the plurality of battery stacks 13, an electronic device BCU (Battery Control Unit) 31 (see FIG. 9) and a junction box 32 (see FIG. 9), and an electrical wiring (not shown) for electrically connecting the battery stack 13 and the electronic device.

[0019] As shown in the drawing, the battery case 19 is formed by molding a steel plate or a synthetic resin plate such as iron or aluminum into a substantially box shape with an open upper portion. The battery case 19 has a longitudinal direction in the vehicle width direction of the vehicle 12, a short side direction in the front-rear direction of the vehicle 12, and a space for accommodating two battery stacks 13 substantially in parallel in the front-rear direction of the vehicle 12.

[0020] The battery stack 13 is configured by serially connecting a plurality of battery cells 21 (see FIG. 5) in its housing 23 (see FIG. 5). The battery cell 21 is a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery, for example. Each battery cell 21 has, for example, a rectangular flat plate shape and is arranged at equal intervals along the longitudinal direction of the battery stack 13 (the vehicle width direction of the vehicle 12) with a small gap in front and behind it.

[0021] The frame body frame 14 is, for example, a steel long member such as a square steel pipe, is on the upper side of the battery case 19, and is fixed to the side of the battery case 19 so as to surround the opening 19A of the battery case 19. The frame body frame 14 has a pair of longitudinal frames 14A extending in the vehicle width direction of the vehicle 12, and a pair of short frames 14B extending in a direction substantially orthogonal to the longitudinal frames 14A and bridging between the longitudinal frames 14A. And when the frame body frame 14 is fixed to a vehicle body frame (not shown) around the battery case 19, the battery case 19 is fixed to the vehicle body.

[0022] The protection frame 15 is, for example, a steel long member such as a square steel pipe, and is disposed to bridge between the longitudinal frames 14A along the front-rear direction of the vehicle 12 above the opening 19A of the battery case 19. As shown in the figure, the protection frame 15 is disposed at a substantially central portion in the longitudinal direction of the battery case 19 (the vehicle width direction of the vehicle 12).

[0023] And, for example, when a pole collision occurs in which a pole collides from the central portion at the rear of the vehicle 12, a large impact is locally applied to the vehicle 12, and the rear bumper 12B (see FIG. 1) enters toward the inside of the vehicle 12. At this time, in the protection structure 11 of the in-vehicle battery 10, the protection frame 15 receives the impact to prevent damage to the battery case 19 and to prevent damage to electronic devices such as the battery stack 13 and the BCU 31 in the battery case 19.

[0024] The fixing portion 16 has, for example, a bolt portion 16A (see FIG. 5), a nut portion 16B (see FIG. 5), and a bolt fixing spacer 16C (see FIG. 5), and is fixed to the escape hole 22 (see FIG. 3) of the protection frame 15. Although details will be described later, on the lower end side of the fixing portion 16, a device mounting bracket 18 connected to the anti-vibration bracket 17 fixed to the housing 23 of the battery stack 13 is locked, and the upper end side of the fixing portion 16 is fixed to the protection frame 15. With this structure, the battery stack 13 is suspended and supported with respect to the protection frame 15 at a substantially central portion in its longitudinal direction. Incidentally, as the material of the bolt fixing spacer 16, for example, a metal material such as aluminum or iron is used.

[0025] The anti-vibration bracket 17 (see FIG. 5) is formed, for example, by bending a substantially flat metal plate. The anti-vibration bracket 17 is disposed at substantially the center in the longitudinal direction of the battery stack 13, connected to the bracket 18 for mounting equipment, and is a member for suspending and supporting the battery stack 13.

[0026] The bracket 18 for mounting equipment is formed, for example, by bending a substantially flat metal plate, and is disposed above the battery stack 13 along the longitudinal direction of the battery stack 13 (the vehicle width direction of the vehicle 12). The bracket 18 for mounting equipment is a member for disposing the BCU 31 and the junction box 32 above the battery stack 13.

[0027] The suspension bracket 24 (see FIG. 7) is formed, for example, by bending a substantially flat metal plate. The suspension bracket 24 is fixed to the casings 23 at both ends in the longitudinal direction of the battery stack 13, and is a member for suspending and supporting the battery stack 13.

[0028] As shown in FIG. 5, a cooling duct 25 formed of an insulating resin such as polyethylene or polypropylene is disposed in the battery case 19. Then, by flowing the cooling air conditioned by a vehicle air conditioner (not shown) through the cooling duct 25 in the battery case 19, the battery cells 21 in the two battery stacks 13 are cooled.

[0029] As shown in FIG. 3, two relief holes 22 penetrating in the thickness direction are formed in the protection frame 15. The relief holes 22 are elongated holes that open along the longitudinal direction of the protection frame 15 (the front-rear direction of the vehicle 12), and are substantially elliptical in top view. The width W1 in the short side direction (the vehicle width direction of the vehicle 12) of the relief holes 22 has a width that is at least substantially the same as the diameter of the bolt portion 16A, and the width W2 in the longitudinal direction (the front-rear direction of the vehicle 12) of the relief holes 22 is, for example, a width that is approximately three times the diameter of the bolt portion 16A.

[0030] As shown in Fig. 4A, the bolt fixing spacer 16C is, for example, cylindrical, and a bolt portion 16A is inserted through the central portion thereof. The bolt fixing spacer 16C is fitted into the relief hole 22 so as to contact the inner surface of the relief hole 22 in the short direction of the relief hole 22. On the other hand, in the longitudinal direction of the relief hole 22, the bolt fixing spacer 16C is positioned at approximately the center of the relief hole 22, and has a gap of about the length of one bolt portion 16A in the front-rear direction. Note that the gap may be secured to be about the length of two bolt portions, and any design change is possible.

[0031] Details will be described later with reference to Fig. 8. Due to this structure, when a pole collision occurs where the pole collides from the central portion at the rear of the vehicle 12 and the relief hole 22 moves forward of the vehicle 12 together with the protection frame 15, the bolt fixing spacer 16C uses the above gap in the relief hole 22 and shifts to the position on the rear side of the vehicle 12 of the relief hole 22. Then, the bolt portion 16A inserted into the bolt fixing spacer 16C can maintain the initial fixing position with respect to the battery case 19 (see Fig. 2), and the battery stack 13 supported by the bolt portion 16A is also maintained at the initial mounting position in the battery case 19.

[0032] As a result, inside the battery case 19, it is possible to prevent the battery stack 13 from colliding with the other battery stack 13 and peripheral components, and to prevent the battery cells 21 in the battery stack 13 from being damaged.

[0033] Also, as shown in Fig. 4B, the bolt fixing spacer 16D may have substantially the same shape as the shape of the relief hole 22. A relief hole 16E is formed in the central portion of the bolt fixing spacer 16D. As shown in the drawing, the bolt fixing spacer 16D is fitted inside the relief hole 22 in the short direction of the relief hole 22, and is disposed with a slight gap in the longitudinal direction of the relief hole 22.

[0034] In this structure, when a pole collision occurs in the vehicle 12, the escape hole 22 and the bolt fixing spacer 16D move forward with the protective frame 15 in the vehicle 12. Then, the bolt portion 16A is displaced to the rear side of the vehicle 12 of the escape hole 16E, so that the battery stack 13 is maintained at the initial mounting position in the battery case 19 and the same effect is obtained as in the case of the bolt fixing spacer 16C described above.

[0035] Also, as shown in FIG. 4C, as the fixing portion 16, the bolt portion 16A may be directly inserted into the escape hole 22 without using the bolt fixing spacers 16C and 16D and tightened with the nut portion 16B to suspend and support the battery stack 13.

[0036] In this structure, when a pole collision occurs in the vehicle 12, the escape hole 22 moves forward with the protective frame 15 in the vehicle 12. Then, the bolt portion 16A is displaced to the rear side of the vehicle 12 of the escape hole 22, so that the battery stack 13 is maintained at the initial mounting position in the battery case 19 and the same effect is obtained as in the case of the bolt fixing spacer 16C described above.

[0037] FIG. 5 is a cross-sectional view taken along the line A-A shown in FIG. 2, showing a cross-section of a substantially central portion of the battery case 19 in which the protective frame 15 is disposed. FIG. 6 is an enlarged cross-sectional view of the upper rear side of the in-vehicle battery 10 and its protective structure 11 shown in FIG. 5. FIG. 7 is a cross-sectional view taken along the line B-B shown in FIG. 2, showing a cross-section of a suspension support structure at both longitudinal ends of the battery stack 13.

[0038] As shown in FIGS. 5 to 7, in the battery case 19, the two battery stacks 13 are disposed substantially in parallel in the front-rear direction of the vehicle 12, and the battery stack 13 is suspended and supported by the protective frame 15 by supporting both ends and the central portion thereof. With this structure, in the battery case 19, a skeleton structure for protecting the battery stack 13 from the impact during a vehicle collision is unnecessary or minimal, so that an increase in the manufacturing cost and weight of the battery case 19 can be prevented.

[0039] Specifically, as shown in FIGS. 5 and 6, at approximately the center of the battery stack 13, one end side of the anti-vibration bracket 17 is fixed to the housing 23 that fixes both ends of the battery cell 21 in the longitudinal direction of the vehicle 12 by welding or the like. The other end side of the anti-vibration bracket 17 is fixed to the equipment mounting bracket 18 via bolts or the like. And, a locking hole (not shown) is formed in the equipment mounting bracket 18 at approximately the center in the longitudinal direction of the vehicle 12. By inserting the bolt portion 16A into the locking hole, the approximate center portion of the battery stack 13 is suspended and supported by the protection frame 15 via the fixing portion 16.

[0040] Also, in the fixing portion 16, by tightening the nut portion 16B against the bolt portion 16A so that the upper surface of the equipment mounting bracket 18 and the bottom surface of the protection frame 15 are in contact, the equipment mounting bracket 18 is fixed to the protection frame 15. With this structure, the battery stack 13 is in a three-point support state at both ends and the central portion in its longitudinal direction, and the amplitude amount at the approximate center portion of the battery stack 13 is significantly reduced.

[0041] On the other hand, as shown in FIG. 7, one end side of the suspension bracket 24 is fixed to the housing 23 of the battery stack 13 by welding or the like at both ends in the longitudinal direction of the housing 23. Also, the other end side of the suspension bracket 24 is fixed to the short-side frame 14B of the frame body frame 14 via bolts or the like.

[0042] With this structure, the battery stack 13 is suspended in the battery case 19. However, even when the total length in the longitudinal direction of the battery stack 13 becomes long, the amplitude at the approximate center portion thereof is regulated, resulting in a structure in which the amplitude in the longitudinal direction of the battery stack 13 is suppressed. As a result, it becomes difficult for the battery stack 13 to collide with peripheral components such as the battery case 19 and the cooling duct 25 due to the vibration during the running of the vehicle 12. And, while increasing the number of battery cells 21 accommodated in one battery stack 13 and realizing higher output and higher capacity of the in-vehicle battery 10, breakage of each battery cell 21 due to vibration is prevented.

[0043] As shown in FIG. 8, for example, when a pole collision occurs where a pole collides with the central part behind the vehicle 12, a large impact force is locally applied to the vehicle 12, and the rear bumper 12B (see FIG. 1) enters toward the inside of the vehicle 12. Then, by receiving the impact force with the protection frame 15 and the frame body frame 14 fixed to the vehicle body, it is possible to prevent the battery case 19 from being greatly deformed and damaged.

[0044] However, depending on the magnitude of the impact force, the longitudinal frame 14A of the frame body frame 14 may bend toward the front side of the vehicle 12, and the protection frame 15 may be pushed out toward the front side of the vehicle 12 or may bend in the vehicle width direction. Then, when the protection frame 15 moves toward the front side of the vehicle 12 due to the impact force, the escape hole 22 formed in the protection frame 15 also moves toward the front side of the vehicle 12 together. At this time, the bolt fixing spacer 16C shown in FIG. 4A slides against the inner surface of the escape hole 22, so that the bolt fixing spacer 16C is displaced toward the rear side of the vehicle 12 of the escape hole 22. As a result, the bolt portion 16A and the nut portion 16B inserted into the bolt fixing spacer 16C are also displaced toward the rear side of the vehicle 12 of the escape hole 22.

[0045] That is, when the escape hole 22 moves toward the front side of the vehicle 12 together with the protection frame 15 due to the impact force, the bolt portion 16A and the bolt fixing spacer 16C remain at the initial attachment position with respect to the battery case 19 (see FIG. 2). Then, as shown in the drawing, the bolt portion 16A and the bolt fixing spacer 16C move from the central part of the escape hole 22 toward the rear end side.

[0046] As described above, when using the bolt fixing spacer 16D shown in FIG. 4B, the bolt fixing spacer 16D moves forward with the protection frame 15 to the front side of the vehicle 12. However, the bolt portion 16A is displaced rearward with respect to the escape hole 16E of the bolt fixing spacer 16D, so that the bolt portion 16A remains at the original attachment position with respect to the battery case 19. On the other hand, when the bolt portion 16A is directly inserted into the escape hole 22 as shown in FIG. 4C, the bolt portion 16A is displaced rearward with respect to the escape hole 22, so that the bolt portion 16A remains at the original attachment position with respect to the battery case 19.

[0047] With this structure, the battery stack 13 supported by the bolt portion 16A can remain at substantially the same position as the original fixed position with respect to the battery case 19 without moving forward with the protection frame 15 to the front side of the vehicle 12. As a result, when the pole collision occurs, inside the battery case 19, it is possible to prevent the battery stack 13 from colliding with the side surface of the battery case 19 and also from colliding with each other. And it is possible to prevent the individual battery cells 21 inside the battery stack 13 from being damaged by the collision.

[0048] As shown in FIG. 9, in the in-vehicle battery 10, above the battery stack 13 of the battery case 19, the electronic devices BCU 31 and junction box 32 are arranged on the upper surface of the equipment mounting bracket 18. As described above, the BCU 31 is arranged between the short-side frame 14B on the right side of the paper and the protection frame 15, and the junction box 32 is arranged between the short-side frame 14B on the left side of the paper and the protection frame 15. And the BCU 31 and the junction box 32 are arranged in the vicinity of the protection frame 15 so as to sandwich the protection frame 15 therebetween.

[0049] As shown in the figure, in the BCU 31 and the junction box 32, the back side is fixed to the equipment mounting bracket 18 by bolts or the like, and the front side is fixed to the protection frame 15 and the short-side frame 14B by bolts or the like via the fixing bracket 33.

[0050] Here, as described above with reference to FIG. 8, when the pole collision occurs, the protection frame 15 absorbs the impact and may bend in the vehicle width direction of the vehicle 12. In this case, both side surfaces of the protection frame 15 in the vehicle width direction come into contact with the BCU 31 and the junction box 32, thereby significantly reducing the amount of bending. And, in combination with the structure of the relief hole 22, it becomes difficult for the battery stack 13 to collide with peripheral components and the like, and individual battery cells 21 in the battery stack 13 are prevented from being damaged by the collision.

[0051] Finally, with the protection structure 11 of the in-vehicle battery 10, the total length of the battery stack 13 in the longitudinal direction can be increased, and the number of battery cells 21 to be mounted can be increased. And, it becomes possible to reduce the number of battery stacks 13 housed in the battery case 19, and the electrical wiring (not shown) for electrically connecting the battery stack 13 and the BCU 31 etc. is reduced. As a result, the manufacturing cost is reduced and the weight of the entire in-vehicle battery 10 is reduced. Also, by reducing the electrical wiring, the internal resistance of the in-vehicle battery 10 is reduced, and the power consumption and heat generation amount of the in-vehicle battery 10 are reduced.

[0052] In addition, in this embodiment, a pair of anti-vibration brackets 17 are bolted to both ends of the equipment mounting bracket 18 in the front-rear direction of the vehicle 12, and the equipment mounting bracket 18 is suspended and supported by the protection frame 15 via the fixing portion 16. However, the present invention is not limited to this case. For example, the anti-vibration bracket 17 may be cross-fixed to the housing 23 of the battery stack 13, and the anti-vibration bracket 17 may be directly suspended and supported by the protection frame 15 via the fixing portion 16. Alternatively, the anti-vibration bracket 17 may be omitted, and the equipment mounting bracket 18 may be directly fixed to the housing 23 of the battery stack 13 by welding or the like.

[0053] Further, a relief hole 22 is formed in the protective frame 15. When the pole collision occurs, the relief hole 22 moves to the front side of the vehicle 11 together with the protective frame 15, and the fixing portion 16 stays at the first fixing position within the relief hole 22, thereby preventing the battery cell 21 from being damaged. This has been described, but the present invention is not limited to this case. For example, by providing a relief hole 22 also at the location where the suspension bracket 24 of the short side frame 14B of the frame body frame 14 is fixed, even when an impact force is applied to the short side frame 14B due to a vehicle collision, the movement of the battery stack 13 within the battery case 19 is prevented, and damage to the battery cell 21 is prevented. In addition, various modifications are possible without departing from the gist of the present invention.

[0054] Next, a protection structure 51 for an in-vehicle battery 50 according to another embodiment of the present invention will be described in detail with reference to the drawings. In the description of the present embodiment, the same reference numerals are generally used for the same members, and repeated descriptions will be omitted. Further, when describing the protection structure 51 of the in-vehicle battery 50, the description will focus on the structure different from the protection structure 11 of the in-vehicle battery 10 described above with reference to FIGS. 1 to 9, and the same reference numerals are generally used for the same members, and repeated descriptions will be omitted.

[0055] FIG. 10 is a perspective view for explaining the protection structure 51 of the in-vehicle battery 50 of the present embodiment. FIG. 11 is a front view for explaining the end plate 56 of the protection structure 51 of the in-vehicle battery 50 of the present embodiment. FIG. 12 is a front view for explaining the center plate 55 of the protection structure 51 of the in-vehicle battery 50 of the present embodiment. Note that the front-back direction of the paper surface indicates the front-back direction of the vehicle 12, the left-right direction of the paper surface indicates the vehicle width direction of the vehicle 12, and the up-down direction of the paper surface indicates the height direction of the vehicle 12.

[0056] As shown in FIG. 10, the protection structure 51 of the in-vehicle battery 50 mainly includes a frame body frame 52 that fixes the in-vehicle battery 50 to the vehicle body, a protection frame 53 that is connected in a direction intersecting the frame body frame 52, a fixing portion 54 that suspends and supports the battery stack 13, a center plate 55 that is fixed to a substantially central portion of the battery stack 13, and a pair of end plates 56 that are fixed to both ends of the battery stack 13. In this embodiment, the frame body frame 52 corresponds to the first frame described in the claims, and the protection frame 53 corresponds to the second frame described in the claims.

[0057] Also, as shown in the figure, the in-vehicle battery 50 mainly includes two battery stacks 13, and without having a battery case 19 of the in-vehicle battery 10, the battery stack 13 is suspended and supported with respect to the frame body frame 52 and the protection frame 53 via the center plate 55 and the end plates 56. In FIG. 10, for convenience of explanation, the BCU 31 and the junction box 32 are omitted from the illustration, but as shown in FIG. 9, they may be disposed above the battery stack 13 via the equipment mounting bracket 18.

[0058] The frame body frame 52 is, for example, a steel long member such as a square steel pipe, and includes a pair of longitudinal frames 52A extending in the vehicle width direction of the vehicle 12, and a pair of transverse frames 52B extending in a direction substantially orthogonal to the longitudinal frames 52A and bridging between the longitudinal frames 52A. And the protection frame 53 is, for example, a steel long member such as a square steel pipe, and is disposed to bridge between the longitudinal frames 52A along the front-rear direction of the vehicle 12.

[0059] As shown in the figure, the frame body frame 52 and the protection frame 53 are formed in a ladder shape, and the pair of transverse frames 52B are respectively disposed above both ends in the longitudinal direction (vehicle width direction of the vehicle 12) of the battery stack 13. On the other hand, the protection frame 53 is disposed above a substantially central portion in the longitudinal direction of the battery stack 13. And the pair of transverse frames 52B and the protection frame 53 are arranged in parallel in a direction substantially orthogonal to the longitudinal frames 52A.

[0060] The fixing part 54 has, for example, a bolt part 54A and a bolt fixing spacer 54B. The bolt part 54A is inserted through the relief holes 22 of the frame body frame 52 and the protection frame 53, and the tip 54C side thereof is fitted to the support shaft parts 62 of the center plate 55 and the end plate 56. Incidentally, the bolt fixing spacer 54B is fitted into the relief hole 22, similarly to the bolt fixing spacers 16C and 16D.

[0061] As shown in FIG. 11, the end plate 56 is made of, for example, a resin or a steel plate formed in a plate shape, and is a member that covers the front and rear side surfaces of the battery cells 21 located at both ends. The end plate 56 has a plate-shaped base portion 61, a pair of support shaft portions 62 integrally formed at both ends of the base portion 61, and a reinforcing rib portion 63 integrally formed with the base portion 61 and the support shaft portions 62.

[0062] As shown in the drawing, a threaded hole portion 62A for inserting and fitting the bolt portion 54A is formed in the support shaft portion 62. The threaded hole portion 62A extends below the reinforcing rib portion 63. When the battery stack 13 is suspended and supported by the frame body frame 52, the tip 54C of the bolt portion 54A is disposed below the reinforcing rib portion 63.

[0063] With this structure, as described above with reference to FIG. 8, when a large impact force is applied from the rear of the vehicle 12 due to a pole collision, the reinforcing rib portion 63 and the bolt portion 54A inserted through the threaded hole portion 62A receive the impact force, preventing the end plate 56 from being damaged. Then, the position where the battery stack 13 was first attached to the vehicle body is maintained.

[0064] As shown in FIG. 12, the center plate 55 is made of, for example, resin or steel plate formed in a plate shape, and is a member disposed inside the housing 23 of the battery stack 13 and at substantially the center of the battery stack 13. The center plate 55 has a plate-shaped base portion 61 and a pair of support shaft portions 62 integrally formed at both ends of the base portion 61. Different from the end plate 56, the center plate 55 has a structure without a reinforcing rib portion 63.

[0065] As shown in the drawing, a bolt portion 54A is inserted into the support shaft portion 62, and a threaded hole portion 62A for fitting is formed. On the other hand, in the center plate 55, the threaded hole portion 62A has a structure that does not reach the base portion 61. That is, the threaded hole portion 62A is formed as the minimum length that can stably suspend and support the center plate 55, and the tip 54C of the bolt portion 54A is not disposed up to the formation region of the base portion 61.

[0066] With this structure, when a large impact force is applied to the vehicle 12 due to a pole collision, the frame frame 52 bends toward the front side of the vehicle 12, and the protection frame 53 is also pushed out toward the front side of the vehicle 12. As shown by the dotted line 64, above the base portion 61 and in the region where the bolt portion 54A is not disposed, the support shaft portion 62 is damaged and cut. Then, substantially the center portion of the battery stack 13 is detached from the protection frame 53.

[0067] That is, the end plate 56 maintains the state of being suspended and supported by the frame frame 52, and the center plate 55 is detached from the protection frame 53, so that the battery stack 13 remains at substantially the same position as the initial fixed position. As a result, when the above-mentioned pole collision occurs, it is possible to prevent the battery stack 13 from colliding with the peripheral components of the vehicle 12 and also prevent the battery stacks 13 from colliding with each other. And it is possible to prevent the individual battery cells 21 in the battery stack 13 from being destroyed by the collision.

[0068] Furthermore, in the present embodiment, when a vehicle collision such as a pole collision of the vehicle 12 occurs, the case where the support shaft portion 62 of the center plate 55 is cut by the impact force and the battery stack 13 remains at the first fixed position has been described, but the present invention is not limited to this case. For example, due to the impact force, as described above with reference to FIG. 8, the escape hole 22 may move forward of the vehicle 12 together with the protection frame 53, the bolt portion 54A may remain at the first position within the escape hole 22, and the battery stack 13 may remain at the first fixed position. Alternatively, a combination of a structure in which the support shaft portion 62 of the center plate 55 is cut and the bolt portion 54A remains at the first position within the escape hole 22 may cause the battery stack 13 to remain at the first fixed position.

[0069] In addition, regarding the in-vehicle battery 50, the case where the battery stack 13 is exposed without having the battery case 19 has been described, but the present invention is not limited to this case. For example, similar to the in-vehicle battery 10, the battery stack 13 may be housed within the battery case 19, and the frame body frame 52 may be fixed to the upper side of the battery case 19. Additionally, various modifications can be made without departing from the scope of the present invention.

Explanation of Reference Numerals

[0070] 10, 50 In-vehicle battery 11, 51 Protection structure 12 Vehicle 13 Battery stack 14, 52 Frame body frame 14A, 52A Longitudinal frame 14B, 52B Transverse frame 15, 53 Protection frame 16, 54 Fixing portion 16A, 54A Bolt portion 17 Anti-sway bracket 18 Equipment mounting bracket 19 Battery case 21 Battery cell 22 Escape hole 23 Housing 31 BCU 32 Junction box 55 Center plate 56 End plate 61 Base 62 Support shaft part 62A Threaded hole part 63 Reinforcing rib part

Claims

1. A protection structure for an in-vehicle battery that fixes and protects an in-vehicle battery having a battery stack to a vehicle body, comprising: a first frame connected to an upper side of a battery case in which the battery stack is housed and fixing the battery case to the vehicle body; a second frame disposed above the battery case and connected to the first frame; a fixing portion fixed to the second frame and suspending and supporting the battery stack; a plurality of electronic devices for electronically controlling the battery stack; a bracket for mounting devices extending in the longitudinal direction of the battery stack and disposed above the battery stack; and the second frame is disposed in a direction intersecting the longitudinal direction of the battery stack and is disposed at least at a substantially central portion in the longitudinal direction of the battery stack; the electronic devices are fixed to an upper surface of the bracket for mounting devices so as to sandwich the second frame. A protection structure for an in-vehicle battery, characterized in that.

2. The second frame is formed with a relief hole that is long in the extending direction of the second frame while fixing the fixing portion, The bolt portion of the fixing portion is fixed at a position spaced apart from an end portion on the rear side of the vehicle body of the relief hole at least within the relief hole. The protection structure for an in-vehicle battery according to claim 1, characterized in that.

3. further comprising a vibration-proof bracket having a first end side fixed to the battery stack and a second end side fixed to the bracket for mounting devices; The fixing portion suspends and supports the battery stack in a state where a part of the bracket for mounting devices is in contact with the second frame. The protection structure for an in-vehicle battery according to claim 1 or claim 2, characterized in that.

4. a pair of end plates respectively disposed at both ends in the longitudinal direction of the battery stack; a center plate disposed at a substantially central portion in the longitudinal direction of the battery stack; and the center plate has a base portion disposed between battery cells in the battery stack and a pair of support shaft portions formed at both end portions of the base portion; The fixing portion suspends and supports the battery stack by being fixed to the support shaft portion above the base portion. The protection structure for an in-vehicle battery according to claim 1, characterized in that.

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