Vehicle underbody structure

Abstract

To be able to suppress a collision load from being transmitted to a battery unit when the collision load is applied to a charging unit and suppress the charging unit applied with the collision load from coming off from the battery unit, in mounting the charging unit for charging in a non-contact manner on the battery unit.SOLUTION: A charging unit 10 comprises a coil casing 20 and a plurality of brackets 30A-30E. The coil casing 20 stores a charging coil 45. The plurality of brackets 30A-30E comprise the front-side bracket 30B arranged at a front side of a vehicle, a rear-side bracket 30C arranged at a rear side of the vehicle, and the center bracket 30A arranged between the front-side bracket 30B and the rear-side bracket 30C, where the front-side bracket 30B and the rear-side bracket 30C are lower in rigidity in comparison with the center bracket 30A.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a vehicle underbody structure in which a battery and a charging unit for wireless charging are mounted under a floor of the vehicle. [Background technology]

[0002] 2. Description of the Related Art Vehicles, such as electric vehicles, that use rotating electric machines as their driving sources are equipped with batteries as their power sources. For example, a battery pack is attached under the floor (vehicle compartment) of the vehicle.

[0003] In addition, in Patent Document 1, a power receiving unit for contactless charging is attached under the floor of the vehicle. In contactless charging, the power receiving unit and a power supply unit installed on the road surface face each other, and the two are electromagnetically coupled.

[0004] In Patent Document 1, the power receiving unit can be attached later. Specifically, a mounting unit, which is a framework, is fixed to a floor panel. The power receiving unit is then fixed to the mounting unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-254778 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, a charging unit for contactless charging may be attached to a battery unit in some cases. For example, the charging unit is fastened under a reinforcement that is a reinforcing member provided under the battery unit and supports the battery.

[0007] By mounting the charging unit on the underside of the vehicle, the vehicle's minimum ground clearance is reduced. For example, the height dimension between the underside of the charging unit and the road surface may be equal to or less than the height dimension of a curb or parking block (hereinafter collectively referred to as "curb, etc."). In that case, for example, there is a risk of the charging unit colliding with the curb, etc., when the vehicle is backing up. Furthermore, the collision load may be transmitted to the battery unit to which the charging unit is mounted, which may lead to damage to the battery unit.

[0008] In addition, if a charging unit collides with a curb or the like, it must be transported to a repair shop such as a dealer to check its condition or to be replaced. Therefore, it is required that the charging unit be fastened to the battery unit from the site where the charging unit was damaged to the repair shop.

[0009] Therefore, this specification discloses a vehicle undercarriage structure that, when a charging unit for contactless charging is attached to a battery unit, is capable of suppressing the transmission of a collision load to the battery unit when the collision load is applied to the charging unit, while also suppressing the charging unit to which the collision load is applied from falling off the battery unit. [Means for solving the problem]

[0010] This specification discloses a vehicle underbody structure. The structure includes a battery unit attached under a floor panel, and a charging unit for contactless charging attached to the underside of the battery unit. The battery unit includes a battery, a battery casing, and a reinforcing member. The battery casing houses the battery. The reinforcing member is provided on a bottom plate of the battery casing and supports the battery. The charging unit includes a coil casing and multiple brackets. The coil casing houses a charging coil. The multiple brackets extend from an upper plate of the coil casing in the vehicle height direction, and have upper ends fastened to the reinforcing member. The multiple brackets further include a front bracket installed relatively to the front of the vehicle, a rear bracket installed relatively to the rear of the vehicle, and a center bracket installed between the front bracket and the rear bracket along the vehicle longitudinal direction. Here, the front bracket and the rear bracket have lower axial rigidity than the center bracket.

[0011] According to the above configuration, for example, when the coil casing hits a curb while the vehicle is backing up, the rear bracket is crushed in the vehicle height axis direction and the front bracket is stretched in the vehicle height axis direction. The collision load is absorbed by the deformation of the rear bracket and the front bracket. Furthermore, since the support of the coil casing by the center bracket is maintained, the charging unit is prevented from falling off the battery unit.

[0012] In the above configuration, the coil casing may have a bending rigidity lower than that of the reinforcing member.

[0013] According to the above configuration, the coil casing is deflected and deformed before the reinforcing member is deflected, so that the transmission of the collision load to the reinforcing member is suppressed.

[0014] In the above configuration, the front bracket and the rear bracket may include a bellows tube portion having reduced diameter portions and increased diameter portions alternately provided along the vehicle height axis, and the center bracket may include a straight tube portion having a linear ridge line along the vehicle height axis.

[0015] By making the front bracket and rear bracket shaped to be easily deformed in the vehicle height axis direction and the center bracket shaped to be difficult to deform in the vehicle height axis direction, the rear bracket and front bracket are able to absorb collision loads, and the center bracket is able to support the coil casing. Effect of the Invention

[0016] According to the present invention, when a contactless charging unit is attached to a battery unit, when a collision load is applied to the charging unit, it is possible to suppress the transmission of the load to the battery unit, while also preventing the charging unit to which the collision load is applied from falling off the battery unit. [Brief description of the drawings]

[0017] [Figure 1] 1 is an exploded perspective view illustrating a vehicle underbody structure according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view illustrating the configuration of a battery unit. [Diagram 3] 4 is a perspective view illustrating an example of a bottom structure of a battery casing. FIG. [Figure 4] 1 is a perspective view illustrating a fastening structure of a battery unit; [Diagram 5] FIG. 2 is a perspective view illustrating a charging unit. [Figure 6] 2 is a diagram illustrating an example of a cross section taken along line AA in FIG. 1 when the components in the figure are assembled. [Figure 7] 10A to 10C are diagrams illustrating an example of the behavior of the charging unit 10 when the coil casing collides with a curb. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The vehicle underbody structure according to this embodiment will be described with reference to Figures 1 to 7. In Figures 1 to 7, the vehicle front-rear direction is indicated by an axis represented by the symbol FR, the vehicle width direction (hereinafter, appropriately referred to as the vehicle width direction) is indicated by an axis represented by the symbol RW, and the vehicle height direction (hereinafter, appropriately referred to as the vehicle height direction) is indicated by an axis represented by the symbol UP. The FR axis, the RW axis, and the UP axis are perpendicular to one another.

[0019] 1 is an exploded perspective view illustrating each component of a vehicle underbody structure according to the present embodiment. The vehicle underbody structure according to the present embodiment includes a battery unit 50 and a charging unit 10. The vehicle underbody structure according to the present embodiment is applied to, for example, an electric vehicle BEV (Battery Electric Vehicle).

[0020] <Body frame> 1 shows an example of framework members for a vehicle floor. Among these framework members, front side members 100A, 100B, rear side members 110A, 110B, and rockers 150A, 150B are provided as members extending in the vehicle front-rear direction. Also, a rear cross member 130 is provided as a member extending in the vehicle width direction.

[0021] A pair of rockers 150A, 150B are provided at both ends of the vehicle floor in the vehicle width direction. Furthermore, front side members 100A, 100B are provided on the inner sides of the rockers 150A, 150B in the vehicle width direction, respectively.

[0022] The front side members 100A, 100B extend from a bumper reinforcement (not shown) at the front end of the vehicle in the longitudinal direction of the vehicle. The front side members 100A, 100B further extend onto the vehicle interior floor through a dash panel 140. The rear ends of the front side members 100A, 100B are connected to the front ends of the rear side members 110A, 110B. A rear cross 130 is stretched between the rear side members 110A, 110B.

[0023] Fig. 4 illustrates the detailed structure of the front side members 100A, 100B. Note that, although Fig. 4 illustrates only the front side member 100B on the left side in the vehicle width direction, the front side member 100A on the right side in the vehicle width direction also has a similar structure to that in Fig. 4.

[0024] The front side member 100B includes a front side member upper 101B and a front side member lower 102B that sandwich the floor panel 160 in the vehicle height direction. The front side member upper 101B and the front side member lower 102B both have a hat-shaped cross section, and a closed cross-sectional structure is formed by abutting their open ends against each other.

[0025] As illustrated in FIG. 4, the battery unit 50 is attached under the floor panel 160. More specifically, a fastening hole 102B1 is formed in the bottom wall of the front side member lower 102B, penetrating in the vehicle height direction. Furthermore, a weld nut 103 (welded nut) is provided so that the central axis of the fastening hole 102B1 and the screw axis are coaxial. A plurality of the fastening holes 102B1 and weld nuts 103 are provided along the longitudinal direction (vehicle front-rear direction) of the front side member 100B. Specifically, the number of fastening holes 102B1 and weld nuts 103 corresponding to the number of reinforcement cross members 70 provided in the battery unit 50 are provided in the bottom wall of the front side member lower 102B at an equal pitch to the reinforcement cross members 70.

[0026] 4, a bolt 104 is screwed into the weld nut 103. The bolt 104 is also inserted into fastening holes 71 formed at both ends of the reinforcement cross member 70 in the vehicle width direction. Thus, both ends of the multiple reinforcement cross members 70 in the vehicle width direction are fastened to the front side members 100A, 100B via the weld nut 103 and the bolt 104. In addition, the distance in the vehicle height direction between the front side members 100A, 100B and the reinforcement cross member 70 is managed by a collar 105 into which the bolt 104 is inserted.

[0027] 1, the lower ends of a pair of battery brackets 52, 52 are fastened to the rear end of the battery unit 50. The upper ends of the battery brackets 52, 52 are fastened to the rear cross 130.

[0028] <Battery unit> Fig. 2 illustrates an exploded perspective view of the battery unit 50. As illustrated in Fig. 4, the battery unit 50 is disposed under the floor and is attached under a floor panel 160. The battery unit 50 includes a battery 55, a battery casing 60, and reinforcement members 70 and 75A-75C (see Fig. 3) which are reinforcing members.

[0029] A plurality of batteries 55 are housed in a battery casing 60. A plurality of battery cells are stacked in one battery 55. The battery cells are formed of, for example, a nickel-metal hydride secondary battery, a lithium-ion secondary battery, an all-solid-state battery, or the like.

[0030] The battery casing 60 is a housing that houses a plurality of batteries 55, and includes a cover 61 that is an upper member and a tray 62 that is a lower member. Both the cover 61 and the tray 62 are made of a thin metal plate material such as an aluminum panel.

[0031] The cover 61 includes a top plate 61A extending substantially horizontally and a side plate 61B connected to the periphery of the top plate 61A and extending downward. A flange 61C for connection to the tray 62 is provided at the lower end of the side plate 61B.

[0032] The tray 62 is formed in a substantially boat-like shape. The tray 62 includes a bottom plate 62A extending substantially horizontally and a side plate 62B connected to the periphery of the bottom plate 62A and extending upward. Furthermore, a flange 62C that is connected to a flange 61C of the cover 61 is provided on the upper end of the side plate 62B.

[0033] A plurality of intra-tray crosses 57 are provided at intervals along the vehicle front-rear direction on the inner surface (upper surface) of the bottom plate 62A of the tray 62. The intra-tray crosses 57 are reinforcing members that support the battery 55 together with the reinforcement crosses 70 and the reinforcement members 75A-75C (see FIG. 3), and extend in the vehicle width direction.

[0034] Fig. 3 illustrates the tray 62, the reinforcement cross 70, and the reinforcement members 75A-75C at an angle when the tray 62 in Fig. 2 is turned upside down. The reinforcement cross 70 is provided on the outer surface (lower surface or exposed surface) of the bottom plate 62A of the tray 62.

[0035] The reinforcement cross 70 is a reinforcing member that supports the multiple batteries 55 together with the reinforcement members 75A-75C. A plurality of the reinforcement crosses 70 are provided at intervals along the vehicle front-rear direction on the outer surface (lower surface) of the bottom plate 62A of the tray 62.

[0036] For example, both ends of the reinforcement cross 70 in the vehicle width direction protrude outward from both ends of the battery casing 60 in the vehicle width direction. With this structure, the reinforcement cross 70 can receive an obstacle (barrier) that approaches the battery unit 50 from the side in front of the battery casing 60 during a side collision (side impact) of the vehicle.

[0037] Fastening holes 71 penetrating in the thickness direction are provided at both ends of the reinforcement cross 70 in the vehicle width direction. Bolts 104 shown in FIG. 4 are inserted into the fastening holes 71. The bolts 104 are also inserted into a collar 105 and a fastening hole 102B1 of the front side member lower 102B (as well as the front side member lower 102A, not shown). The bolts 104 are further screwed into weld nuts 103 provided on the front side member lowers 102A, 102B. In this way, the battery unit 50 is fastened to the front side members 100A, 100B via the reinforcement cross 70.

[0038] Reinforcement members 75A-75C, which are reinforcing members, are provided on the bottom plate 62A of the tray 62 so as to intersect with the multiple reinforcement crosses 70. The reinforcement members 75A-75C extend in the front-rear direction of the vehicle and are provided at intervals in the vehicle width direction. For example, the reinforcement member 75A is provided in the center of the tray 62 in the vehicle width direction. In addition, the reinforcement members 75B and 75C are provided on both sides of the reinforcement member 75A in the vehicle width direction.

[0039] The reinforcement members 75A-75C are provided so as to cover the reinforcement cross 70, that is, below the reinforcement cross 70. For example, the reinforcement members 75A-75C are fixed to the multiple reinforcement crosses 70 by welding. The reinforcement members 75A-75C are provided with multiple fastening holes 73 in their thickness direction. These fastening holes 73 are provided in pairs in the front-rear direction of the vehicle, for example, at intersections with the reinforcement crosses 70.

[0040] For example, three sets of fastening holes 73 are provided in the reinforcement member 75A in the vehicle front-rear direction. Specifically, among the multiple reinforcement cross sections 70, one set of fastening holes 73, 73 is drilled at each of the intersections of the rear end reinforcement cross section 70A, the reinforcement cross section 70B in front of it, and the reinforcement cross section 70C further in front of it.

[0041] Further, a pair of fastening holes 73 are provided in each of the reinforcement members 75B and 75C. Specifically, a pair of fastening holes 73, 73 are drilled at the intersections of the reinforcement cross members 70B one position forward from the rear end of each of the multiple reinforcement cross members 70.

[0042] The fastening holes 73 are used for fastening the charging unit 10. When the charging unit 10 is a so-called add-on unit and is not attached to the vehicle, the fastening holes 73 are blocked with a seal clip, a waterproof seal, or the like (not shown).

[0043] <Charging unit> 5 illustrates an example of a perspective view of the charging unit 10. The charging unit 10 is attached to the underside of the battery unit 50. The charging unit 10 is a charging-side (power-receiving) unit for contactless charging. For example, when a power supply unit (not shown) is installed on the road surface, the charging unit 10 and the power supply unit are electromagnetically coupled to each other by facing each other.

[0044] For example, charging unit 10 is provided with charging coil 45 (see FIG. 6), and the power supply unit is also provided with a power supply coil. Furthermore, magnetic field resonance is used to transmit power from the power supply coil to charging coil 45. Note that such wireless power transmission technology using magnetic field resonance is known, and therefore will not be described below.

[0045] 5 and 6, charging coil 45 is housed in coil casing 20. Fig. 6 illustrates an FR-UP cross section of the center portion in the vehicle width direction when the body frame, battery unit 50, and charging unit 10 in Fig. 1 are assembled.

[0046] The coil casing 20 is a housing having a substantially rectangular parallelepiped shape, and is made of a metal panel material such as an aluminum panel. For example, the coil casing 20 is configured to have lower bending rigidity than the reinforcement members 75A-75C, which are reinforcing members. For example, the coil casing 20 is made of an aluminum panel, which is a thin plate, and the reinforcement members 75A-75C are made of high tensile steel that is thicker than the coil casing 20.

[0047] A plurality of brackets are provided on the upper plate 22 of the coil casing 20. Specifically, a center bracket 30A, a front bracket 30B, a rear bracket 30C, a right bracket 30D, and a left bracket 30E are provided on the upper plate 22. All of these brackets 30A-30E extend in the vehicle height direction from the exposed surface of the upper plate 22, and flanges 34A-34E at their upper ends are fastened to reinforcement members 75A-75C, which are reinforcing members.

[0048] The rear bracket 30C is provided at the center in the vehicle width direction and at the rear in the vehicle front-rear direction of the upper plate 22 of the coil casing 20. The rear bracket 30C is installed relatively further rearward than the other brackets 30A, 30B, 30D, and 30E.

[0049] The rear bracket 30C has a flange 36C at its lower end. The flange 36C is provided to protrude in the vehicle front-rear direction from the lower end of the bellows tube portion 32C, for example. Referring to the enlarged view surrounded by the dashed-dotted circle in Fig. 6, fastening holes are drilled in the flange 36C in the thickness direction. Fastening holes are also drilled in the upper plate 22 of the coil casing 20, and both holes are aligned and fastened with bolts and nuts.

[0050] Alternatively, flange 36C and upper plate 22 may be joined by welding. For example, charging unit 10 may be supplied as a so-called add-on part with coil casing 20 and brackets 30A-30E integrated together. In such a case, since there is no particular need to remove brackets 30A-30E from coil casing 20, coil casing 20 and brackets 30A-30E are welded together. Also, coil casing 20 and brackets 30A-30E are welded together when a gap as shown in FIG. 6 cannot be secured between upper plate 22 of coil casing 20 and charging coil 45.

[0051] The rear bracket 30C also has a flange 34C at its upper end. The flange 34C protrudes in the vehicle front-rear direction from the upper end of the bellows tube portion 32C, for example. A pair of fastening holes 38C, 38C are drilled in the flange 34C in the thickness direction. The pitch of the fastening holes 38C, 38C is equal to the pitch of the pair of fastening holes 73, 73 of the reinforcement members 75A-75C.

[0052] Note that equal pitch does not only mean exact agreement, but also includes a state including design tolerances.

[0053] A gap is provided between the reinforcement member 75A and the reinforcement cross 70, and a weld nut 21 is provided in the gap. The weld nut 21 is aligned with the fastening hole 73 of the reinforcement cross 70.

[0054] Furthermore, the fastening holes 38C of the flange 34C of the rear bracket 30C and the fastening holes 73 of the reinforcement cross 70 are aligned, and the bolts 23 are screwed into the fastening holes 38C, 73 and the weld nuts 21. As a result, the coil casing 20 is fastened to the reinforcement member 75A via the rear bracket 30C.

[0055] The bellows tube portion 32C is erected in the vehicle height direction so as to connect the flanges 34C and 36C. The bellows tube portion 32C has reduced diameter portions and expanded diameter portions alternately provided along the vehicle height axis. For example, in the example of Fig. 5, the bellows tube portion 32C has a rectangular tube shape, but may have a cylindrical shape.

[0056] The front bracket 30B is provided at the center in the vehicle width direction and at the front in the vehicle front-rear direction of the upper plate 22 of the coil casing 20. The front bracket 30B is installed relatively further forward than the other brackets 30A, 30C-30E.

[0057] The front bracket 30B includes flanges 34B, 36B and a bellows tube portion 32B, the structures of which are similar to the flanges 34C, 36C and the bellows tube portion 32C of the rear bracket 30C.

[0058] The right bracket 30D is provided on the right side in the vehicle width direction and in the center in the vehicle front-rear direction of the upper plate 22 of the coil casing 20. The right bracket 30D is installed relatively to the right in the vehicle width direction compared to the other brackets 30A-30C, 30E.

[0059] The left bracket 30E is provided on the left side in the vehicle width direction and in the center in the vehicle front-rear direction of the upper plate 22 of the coil casing 20. The left bracket 30E is installed relatively to the left in the vehicle width direction compared to the other brackets 30A-30D.

[0060] The right bracket 30D includes a bellows tube portion 32D and flanges 34D and 36D, and the left bracket 30E includes a bellows tube portion 32E and flanges 34E and 36E. The bellows tube portions 32D and 32E, the flanges 34D and 34E, and the flanges 36D and 36E have the same structures as the bellows tube portion 32C, the flange 34C, and the flange 36C of the rear bracket 30C.

[0061] The center bracket 30A is provided at the center in the vehicle width direction and in the vehicle front-rear direction of the upper plate 22 of the coil casing 20. That is, the center bracket 30A is provided between the front bracket 30B and the rear bracket 30C along the vehicle front-rear direction. The center bracket 30A is also provided between the right bracket 30D and the left bracket 30E along the vehicle width direction.

[0062] The center bracket 30A includes flanges 34A and 36A, which are similar in structure to the flanges 34C and 36C of the rear bracket 30C.

[0063] On the other hand, the center bracket 30A has a straight tube portion 32A instead of the bellows tube portion 32C of the rear bracket 30C. The straight tube portion 32A is erected in the vehicle height direction so as to connect between the flanges 34A and 36A. Furthermore, the straight tube portion 32A has a linear ridge line along the vehicle height axis (UP axis). For example, the straight tube portion 32A is formed of a square tube or a cylinder.

[0064] The straight cylinder portion 32A of the center bracket 30A and the bellows cylinder portions 32B-32E of the front bracket 30B, rear bracket 30C, right bracket 30D, and left bracket 30E are configured to have the same thickness. Furthermore, these brackets 30A-32E are configured from the same material (for example, aluminum).

[0065] Therefore, the front bracket 30B, rear bracket 30C, right bracket 30D and left bracket 30E have lower axial rigidity than the center bracket 30A due to the difference in shape between the bellows cylinder portions 32B-32E and the straight cylinder portion 32A.

[0066] The axial rigidity indicates the resistance to deformation due to a load (tensile load and compressive load) applied in the central axial direction of the cylindrical portion. For example, the front bracket 30B, the rear bracket 30C, the right bracket 30D, and the left bracket 30E have a lower modulus of elasticity (lower axial rigidity) than the center bracket 30A.

[0067] <Charging unit behavior when colliding with a curb> 7 illustrates the behavior of the charging unit 10 when the coil casing 20 collides with a curbstone 200. In this example, the curbstone 200 collides with the rear end of the coil casing 20 while the vehicle is backing up. Note that the same behavior as that shown in FIG. 7 is also shown when the coil casing 20 collides with a parking block used as a car stopper instead of the curbstone 200.

[0068] As will be described in detail below, when the vehicle collides with the curbstone 200, the collision load is received solely by the colliding charging unit 10, and the transmission of the collision load to the fastened battery unit 50 is suppressed. In other words, by sacrificing the charging unit 10, damage to the battery unit 50 is suppressed.

[0069] Furthermore, the central bracket 30A maintains the fastening of the charging unit 10 to the battery unit 50. Therefore, the charging unit 10 is prevented from falling off the battery unit 50 while the vehicle to which the (damaged) charging unit 10 is attached is traveling to a repair site such as a dealer.

[0070] 7, when the rear end of the coil casing 20 collides with the front end of the curbstone 200, the rear end of the coil casing 20 rides up on the curbstone 200. In response to this riding up, the bellows tube portion 32C of the rear bracket 30C is crushed and deformed in the axial direction.

[0071] At this time, if the axial rigidity of the rear bracket 30C is high, this may lead to deformation of the reinforcement member 75A; however, the bellows tubular portion 32C is crushed and deformed, so that deformation of the reinforcement member 75A is avoided.

[0072] Furthermore, when the coil casing 20 runs over the reinforcement members 75A-75C, the coil casing 20 is bent and deformed with the central bracket 30A as a fulcrum. As described above, the coil casing 20, which has a relatively low bending rigidity compared to the reinforcement members 75A-75C, is bent and deformed before the reinforcement members 75A-75C, thereby preventing damage to the reinforcement members 75A-75C.

[0073] Furthermore, the bellows tube portion 32B of the front bracket 30B expands and deforms in response to the bending deformation of the coil casing 20. In this manner, during a collision with a curb, the collision load is absorbed by the deformation of the front bracket 30B, the rear bracket 30C, and the coil casing 20.

[0074] On the other hand, center bracket 30A, which has higher axial rigidity than brackets 30B-30E, is prevented from being significantly deformed and maintains a fastened support state at the center portion of coil casing 20. This prevents charging unit 10 (particularly coil casing 20) from falling off battery unit 50.

[0075] 7 illustrates the behavior of the charging unit 10 when the vehicle moves backward, but in short, the bracket at the front of the vehicle's travel direction is crushed and deformed, and the bracket at the rear of the vehicle's travel direction is expanded and deformed, thereby absorbing the collision load. For example, if the vehicle moves forward with a curbstone 200 under the vehicle floor, the front end of the coil casing 20 will collide with the rear end of the curbstone 200. In such a case, the front bracket 30B is crushed and deformed, and the rear bracket 30C is expanded and deformed.

[0076] In addition, for example, when the vehicle is turned around in a parking lot or the like where the road surface is frozen, the vehicle may slip (slide) in the vehicle width direction. In such a case, one of the right bracket 30D and the left bracket 30E is crushed and deformed, and the other is stretched and deformed.

[0077] In any of the above collision modes, the central bracket 30A, which has a relatively higher axial rigidity than the other brackets 30B-30E, is prevented from being deformed or broken, thereby preventing the charging unit 10 from falling off the battery unit 50.

[0078] Furthermore, by making each of the tubular portions of the front bracket 30B, the rear bracket 30C, the right bracket 30D, and the left bracket 30E into a bellows tubular shape, even if these tubular portions are subjected to crushing or stretching deformation, breakage is avoided and the fastening function is maintained if the collision is minor.

[0079] In addition, when reducing the axial rigidity of each of the cylindrical portions of the front bracket 30B, the rear bracket 30C, the right bracket 30D, and the left bracket 30E compared to the straight cylindrical portion 32A of the center bracket 30A, a method other than a bellows tube may be used.

[0080] For example, each of the cylindrical portions of the front bracket 30B, the rear bracket 30C, the right bracket 30D, and the left bracket 30E may be a straight cylindrical portion that is thinner than the straight cylindrical portion 32A.

[0081] Alternatively, each of the cylindrical portions of the front bracket 30B, the rear bracket 30C, the right bracket 30D, and the left bracket 30E may be a straight cylindrical portion having the same thickness as the straight cylindrical portion 32A but made of a material having a lower modulus of longitudinal elasticity than the straight cylindrical portion 32A. [Explanation of symbols]

[0082] 10 charging unit, 20 coil casing, 22 upper plate, 30A center bracket, 30B front bracket, 30C rear bracket, 30D right bracket, 30E left bracket, 32A straight tube portion, 32B-32E bellows tube portion, 45 charging coil, 50 battery unit, 52 battery bracket, 55 battery, 60 battery casing, 70 reinforcement cross, 75A-75C reinforcement member (reinforcement member), 200 curb.

Claims

1. A battery unit that is attached under the floor panel; a charging unit for non-contact charging attached to a lower surface of the battery unit; A vehicle underbody structure comprising: The battery unit includes: A battery; a battery casing that houses the battery; a reinforcing member provided on a bottom plate of the battery casing to support the battery; Equipped with The charging unit includes: a coil casing that houses a charging coil; a plurality of brackets extending in a vehicle height direction from an upper plate of the coil casing and having upper ends fastened to the reinforcing member; Equipped with The plurality of brackets include A front bracket installed relatively to the front of the vehicle; A rear bracket installed relatively to the rear of the vehicle; a center bracket provided between the front bracket and the rear bracket along a vehicle front-rear direction; Equipped with The front bracket and the rear bracket have a lower axial stiffness than the center bracket.

2. 2. The vehicle underbody structure according to claim 1, The coil casing has a bending rigidity lower than that of the reinforcing member.

3. The vehicle underbody structure according to claim 1 or 2, the front bracket and the rear bracket each include a bellows tube portion in which reduced diameter portions and expanded diameter portions are alternately provided along a vehicle height direction axis, The central bracket includes a straight cylindrical portion having a linear ridge line along a vehicle height axis. Vehicle undercarriage.

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