Vehicle

Abstract

The invention provides a vehicle which suppresses torsional load transmitted to a battery pack mounted on a floor of the vehicle. A battery pack (battery case) is mounted below a floor panel of a vehicle. The battery case is fixed to the floor panel by a plurality of first fixing portions disposed along a first imaginary line extending in the front-rear direction of the vehicle at the center of the wheel base of the vehicle, and a plurality of second fixing portions disposed along a second imaginary line extending in the left-right direction of the vehicle at the center of the wheel base of the vehicle.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a vehicle. BACKGROUND

[0002] In Japanese Patent Application Publication No. 2021-123227 (Patent Literature 1), a mounting structure of a battery pack provided to a floor of a vehicle is disclosed. In this Patent Literature 1, an example in which a rim portion of an upper case of the battery pack is fixed to a floor panel by a fixing structure (fastening link bolt or the like) is disclosed. In this mounting structure, a first rim portion close to a suspension mounting portion is not fixed to the floor panel, but a second rim portion far from the suspension mounting portion is fixed to the floor panel. According to this mounting structure, at the first rim portion corresponding to the four corners of the battery pack case, a torsional load transmitted from the floor panel to the battery pack case is effectively released.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2021-123227 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the mounting structure of the battery pack disclosed in Patent Literature 1, when a large torsional load is input to the floor panel, it can be difficult to effectively release the torsional load transmitted to the battery pack case.

[0008] An object of the present disclosure is to appropriately suppress a torsional load transmitted to a battery pack mounted to a floor of a vehicle.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The vehicle of the present disclosure is a vehicle in which a battery pack is mounted to a floor, the battery pack including a battery case that houses a battery cell. The battery case is fixed to the floor by a plurality of first fixing portions arranged along a first imaginary line extending in a vehicle front-rear direction at a center of a wheel track of the vehicle, and a plurality of second fixing portions arranged along a second imaginary line extending in a vehicle left-right direction at a center of an axle track of the vehicle.

[0011] When a large torsional load is input to the floor, a displacement amount around the first imaginary line extending in the vehicle front-rear direction at the center of the wheel track of the vehicle and the second imaginary line extending in the vehicle left-right direction at the center of the axle track of the vehicle is small. According to this configuration, the battery case is fixed to the floor by the first fixing portions arranged along the first imaginary line and the second fixing portions arranged along the second imaginary line, and thus it is possible to suppress a torsional load transmitted to the battery pack.

[0012] It is preferable that the battery pack have a pair of front-and-rear direction sides extending in parallel with the front-and-rear direction of the vehicle and a pair of left-and-right direction sides extending in parallel with the left-and-right direction of the vehicle. It can be that a first imaginary line passes through the center of the battery case and extends in the front-and-rear direction of the vehicle, and a second imaginary line passes through the center of the battery case and extends in the left-and-right direction of the vehicle.

[0013] According to this configuration, the center portions in the front-and-rear direction and the left-and-right direction of the battery pack are fixed to the floor, so the battery pack can be fixed to the floor in good balance and securely.

[0014] It can be that the first fixing portion is preferably disposed at the edge portion of the battery case and the central portion of the battery case, and the second fixing portion is preferably disposed at the edge portion of the battery case and the central portion of the battery case.

[0015] According to this configuration, the vibration of the battery pack can be appropriately suppressed.

[0016] It can be that the first fixing portion and the second fixing portion are preferably configured by a fastening link member.

[0017] According to this configuration, the battery pack can be attached to and detached from the vehicle.

[0018] Effects of Invention

[0019] According to the present disclosure, the torsional load transmitted to the battery pack mounted to the floor of the vehicle can be appropriately suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a view schematically showing the overall configuration of a vehicle on which a battery pack of the present embodiment is mounted.

[0021] Figure 2 is a schematic perspective view of the battery pack of the present embodiment.

[0022] Figure 3 is a plan view of a floor of a vehicle body.

[0023] Figure 4 is a IV-IV sectional view of Figure 3

[0024] Figure 5 is a view schematically showing a fastening link portion of the battery pack in the present embodiment.

[0025] Figure 6 is a view schematically showing a deformation mode of torsion of a floor panel.

[0026] EXPLANATION OF REFERENCE NUMERALS

[0027] ​1 vehicle, 2 control device (ECU), 3 travel drive unit, 10 vehicle body, 20 battery pack, 22 battery case, 221 lower case, 222 upper case, 25 mounting bracket, 27 mounting bolt, 30 front side member, 40 side member, 45 rear floor side member,

[0028] 50 cross member, 55 reinforcement plate, 60 floor panel, 65 suspension tower, 100 bolt, 101 welded nut, 200 nut, M battery module. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same or equivalent portions in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. The dimensional relationship (length, width, thickness, etc.) in each drawing does not reflect the actual dimensional relationship.

[0030] Figure 1 is a view schematically showing the overall configuration of a vehicle 1 on which a battery pack 20 of the present embodiment is mounted. The vehicle 1 is provided with the battery pack 20 that accumulates electric power for travel. The vehicle 1 is configured to be able to travel using the electric power accumulated in the battery pack 20. In the present embodiment, the vehicle 1 is a battery electric vehicle (BEV) that does not have an engine (internal combustion engine), but can also be a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) that has an engine. In addition, in each drawing of the present embodiment, Fr indicates the front of the vehicle, Rr indicates the rear of the vehicle, R indicates the right of the vehicle, L indicates the left of the vehicle, U indicates the upper side, and D indicates the lower side.

[0031] The vehicle 1 is provided with a control device (ECU: Electronic Control Unit) 2. The ECU 2 is configured to perform charge control and discharge control of the battery pack 20. The ECU 2 is configured to include a processor, a RAM (Random Access Memory), and a storage device (none of which is shown). The ECU 2 can be a computer. The processor can be a CPU (Central Processing Unit).

[0032] The vehicle 1 also has a running drive unit 3 and drive wheels W. The running drive unit 3 includes a PCU (Power Control Unit) and an MG (Motor Generator) that are not shown in the drawings, and is configured to cause the vehicle 1 to run using electric power accumulated in the battery pack 20. The PCU is configured to include, for example, an inverter, a converter, and a relay (hereinafter, referred to as "SMR (System Main Relay)"). The PCU is controlled by the ECU 2. The MG is, for example, a three-phase alternating-current motor generator. The MG is driven by the PCU, and is configured to rotate the drive wheels W. The PCU drives the MG using electric power supplied from the battery pack 20. In addition, the MG is configured to generate electric power by regeneration and supply the generated electric power to the battery pack 20. The SMR is configured to switch connection / cut-off of a power path from the battery pack 20 to the PCU. The SMR is in a closed state (connected state) when the vehicle 1 is running.

[0033] The battery pack 20 is mounted on a floor of the vehicle body 10 of the vehicle 1, on the outside of the passenger compartment (under the floor) of the vehicle 1. Figure 2 is a schematic perspective view of the battery pack 20 of the present embodiment. The battery pack 20 includes a battery case 22. The battery case 22 is configured by fixing a flange of an upper case 222 to a flange of a lower case 221 via a sealing member. Inside the battery case 22, a battery module M (refer to Figure 4 ) and a battery monitoring module (not shown), and the like are housed.

[0034] The battery case 22 is a substantially rectangular shape, and has a pair of front-and-rear direction edges 20c, 20d that extend substantially in parallel in the vehicle front-and-rear direction, and a pair of left-and-right direction edges 20a, 20b that extend substantially in parallel in the vehicle left-and-right direction. The front-and-rear direction edges 20c, 20d and the left-and-right direction edges 20a, 20b form the periphery of the battery case 22 (the lower case 221 and the upper case 222). A first imaginary line L1 shown by a single-dot chain line extends in the vehicle front-and-rear direction. A second imaginary line L2 shown by a single-dot chain line extends in the vehicle left-and-right direction. The first imaginary line L1 is positioned at the center of the front-and-rear direction edges 20c, 20d. The second imaginary line L2 is positioned at the center of the left-and-right direction edges 20a, 20b. In the present disclosure, a point at which the first imaginary line L1 and the second imaginary line L2 intersect is also referred to as the center of the battery case 22. The first imaginary line L1 passes through the center of the battery case 22 and extends in the vehicle front-and-rear direction. The second imaginary line L2 passes through the center of the battery case 22 and extends in the vehicle left-and-right direction.

[0035] Four mounting brackets 25 (25a, 25b, 25c, 25d) are provided in the upper case 222. The mounting brackets 25 are fixed to the upper case 222, for example, by welding. The mounting bracket 25a is fixed to a position where the left-right direction edge 20a intersects the first imaginary line L1. The mounting bracket 25b is fixed to a position where the right-left direction edge 20b intersects the first imaginary line L1. The mounting bracket 25c is fixed to a position where the front-rear direction edge 20c intersects the second imaginary line L2. The mounting bracket 25d is fixed to a position where the front-rear direction edge 20d intersects the second imaginary line L2. A bolt insertion hole 251 is formed in the mounting bracket 25. Two bolt insertion holes 251 are formed in the mounting bracket 25, and are arranged on both sides of the first imaginary line L1 or the second imaginary line L2.

[0036] A plurality of mounting bolts 27 are provided in the upper case 222. The base of the mounting bolt 27 is fixed to the upper case 222, for example, by welding, and the mounting bolt 27 has an externally threaded portion 271 protruding from the base. In the present embodiment, seven mounting bolts 27 (27a to 27g) are fixed to the upper case 222. The mounting bolt 27a is fixed at the center of the battery case 22 (the upper case 222), and the mounting bolts 27b, 27c, 27d, 27e are fixed on both sides of the first imaginary line L1 direction of the mounting bolt 27a. The mounting brackets 25a, 25b, the mounting bolts 27a, 27b, 27c, 27d, 27e are arranged along (on) the first imaginary line L1. The mounting bolts 27f, 27g are fixed on both sides of the second imaginary line L2 direction of the mounting bolt 27. The mounting brackets 25c, 25d, the mounting bolts 27a, 27f, 27g are arranged along (on) the second imaginary line L2.

[0037] Figure 3 is a plan view of the floor of the vehicle body 10. In the present embodiment, the vehicle body 10 is a single-shell structure. The floor of the vehicle body 10 includes a pair of front side members 30, a pair of side members (rockers) 40, a pair of rear floor side members 45, a plurality of cross members 50 connecting the left and right side members 40, and a floor panel 60, which are arranged in the vehicle front-rear direction. The battery pack 20 is mounted on the lower surface (under the floor) of the floor panel 60. The battery pack 20 is arranged on the outside of the passenger compartment of the vehicle 1.

[0038] Vehicle 1 has a right front wheel FRw, a left front wheel FLw, a right rear wheel RRw, and a left rear wheel RLw. Vehicle 1 is front-wheel drive, and the right front wheel FRw and left front wheel FLw are equivalent to the drive wheels W. The suspension struts (assemblies of shock absorbers and coil springs (not shown)) of each wheel are fixed to suspension support covers 65. Suspension support covers 65 are directly or indirectly fixed to the front longitudinal beam 30 and the rear floor longitudinal beam 45. Road surface input (load) from the wheels is input through the suspension support covers 65 and from approximately the four corners of the floor panel 60. The suspension support covers 65 are schematically illustrated.

[0039] The battery pack 20 is mounted with a first imaginary line L1 located at the center of the wheelbase Tr of the vehicle 1 and a second imaginary line L2 located at the center of the wheelbase Wb. In this embodiment, the wheelbase Tr is the wheelbase of the front wheels (right front wheel FRw, left front wheel FLw). The first imaginary line L1 also corresponds to the "first imaginary line extending in the longitudinal direction of the vehicle at the center of the wheelbase" of this disclosure. The second imaginary line L2 also corresponds to the "second imaginary line extending in the left-right direction of the vehicle at the center of the wheelbase" of this disclosure. A reinforcing plate 55 is fixed on the floor panel 60 at a position opposite to the mounting bolts 27 arranged along the first imaginary line L1. Through holes 61 are formed in the floor panel 60 and the reinforcing plate 55 for the external threaded portions 271 of the mounting bolts 27 (27a to 27g) to be inserted.

[0040] Figure 4 yes Figure 3 Sectional view IV-IV. The battery module M is housed inside the battery housing 22. The battery module M is, for example, a battery pack composed of battery cells such as lithium-ion batteries and nickel-metal hydride batteries. The battery pack 20 (battery housing 22) is fixed to the lower surface of the floor panel 60. Welded nuts 101 are fixed inside the crossbeam 50 at the front of the vehicle. Bolt through holes 251 of the mounting bracket 25a (see reference) Figure 2 A bolt 100 is inserted into the through hole 251 of the mounting bracket 25b, and the bolt 100 is screwed into the welding nut 101, thereby fixing (fastening) the mounting bracket 25a to the floor panel 60. A welding nut 101 is fixed inside the crossbeam 50 at the rear of the vehicle. A bolt 100 is inserted into the through hole 251 of the mounting bracket 25b, and the bolt 100 is screwed into the welding nut 101, thereby fastening the mounting bracket 25b to the floor panel 60.

[0041] The external thread 271 of the mounting bolt 27 is inserted into the through hole 61 of the floor panel 60 and the reinforcing plate 55. The mounting bolt 27 is fastened to the floor panel 60 by screwing the nut 200 into the external thread 271. An opening 51 is formed in the crossbeam 50 located in the center of the vehicle in the longitudinal direction. The nut 200 is screwed into the external thread 271 using this opening 51.

[0042] existFigure 4 Figure 3 The mounting brackets 25c, 25d, the mounting bolts 27c, 27e, 27f, 27g that do not appear in FIG. 8 are also similarly fixed (fastened and coupled) to the floor panel 60. The mounting brackets 25a to 25d, the mounting bolts 27a to 27g are fastened and coupled to the floor panel 60, whereby the battery case 22 (the battery pack 20) is fixed to the floor of the vehicle 1.

[0043] Figure 5 is a view schematically showing the fastening and coupling positions of the battery pack 20 in the embodiment. In Figure 5 , the black circles show the fastening and coupling positions of the battery pack 20 (the battery case 22) to the floor panel 60, corresponding to the mounting brackets 25a to 25d and the mounting bolts 27a to 27g. The mounting brackets 25a, 25b, the mounting bolts 27a to 27e are arranged along the first imaginary line L1, corresponding to an example of the "first fixing portion" of the present disclosure. The mounting brackets 25c, 25d, the mounting bolts 27a, 27f, 27g are arranged along the second imaginary line L2, corresponding to the "second fixing portion" of the present disclosure. The first imaginary line L1 is located at the center of the wheel track Tr of the vehicle 1, and the second imaginary line L2 is located at the center of the wheel base Wb.

[0044] In Figure 5 , the white circles are positions at which road inputs (loads) from the wheels are input (corresponding to the suspension support cover 65), and the road inputs (loads) are input from the approximately four corners of the floor panel 60. The floor panel 60 is deformed due to this road input (load).

[0045] Figure 6 is a view schematically showing a deformation mode of torsion of the floor panel 60. If a torsional load is applied to the floor panel 60 due to the road inputs (loads) input from the four corners of the floor panel 60, a torsional deformation that has nodes at the first imaginary line L1 and the second imaginary line L2 is generated as shown by the dotted line. At the nodes of the torsion, the displacement amount (deformation amount) is small. As Figure 5 shown in FIG. 8, the fastening and coupling positions of the battery pack 20 are arranged along (on) the first imaginary line L1 and the second imaginary line L2. Therefore, it is possible to suppress the transmission of the torsional load from the first fixing portion (the mounting brackets 25a, 25b, the mounting bolts 27a to 27e) and the second fixing portion (the mounting brackets 25c, 25d, the mounting bolts 27a, 27f, 27g) to the battery pack 20 (the battery case 22).

[0046] ​In the present embodiment, the battery case 22 is substantially rectangular in shape, the first imaginary line L1 is located at the center of the front-and-rear direction edges 20c and 20d, and the second imaginary line L2 is located at the center of the left-and-right direction edges 20a and 20b. Therefore, the first fixing portion (mounting brackets 25a and 25b, mounting bolts 27a to 27e) and the second fixing portion (mounting brackets 25c and 25d, mounting bolts 27a, 27f, and 27g) fix the battery pack 20 to the floor panel 60 along the center line in the front-and-rear direction and the center line in the left-and-right direction of the battery pack 20. Thus, the battery pack 20 can be firmly fixed to the floor panel 60 with good balance.

[0047] In the present embodiment, the mounting brackets 25a and 25b of the first fixing portion are located at the periphery of the battery pack 20, and the mounting bolts 27a to 27e are located at the central portion of the battery pack 20. The mounting brackets 25c and 25d of the second fixing portion are located at the periphery of the battery pack 20, and the mounting bolts 27a, 27f, and 27g are located at the central portion of the battery pack 20. Since the periphery and the central portion of the battery pack 20 are fixed to the floor panel 60, the vibration of the battery pack 20 can be appropriately suppressed.

[0048] In the present embodiment, the mounting brackets 25 are fastened and coupled to the floor panel 60 by the bolts 100. In addition, the mounting bolts 27 are fastened and coupled to the floor panel 60 by the nuts 200. Thus, the battery pack 20 can be attached to and detached from the vehicle 1.

[0049] In the above-described embodiment, the case where the vehicle body 10 of the vehicle 1 on which the battery pack 20 is mounted is a single-shell structure is described. However, the vehicle body can also be a frame structure using a ladder-shaped frame or the like.

[0050] In the above-described embodiment, the mounting bolts 27 provided with the external thread portion 271 protruding from the base fixed to the upper shell 222 are used to fasten and couple the battery pack 20 (battery case 22) to the floor panel 60. Instead of the mounting bolts 27, a double-headed bolt having a head portion arranged inside the upper shell 222 can also be used.

[0051] It should be understood that the embodiments disclosed herein are illustrative and not restrictive in all aspects. The scope of the disclosure is not represented by the description of the above-described embodiments, but by the claims, and is intended to include all modifications equivalent in meaning and scope to the claims.

Claims

1. A vehicle that mounts a battery pack on a floor, wherein the battery pack includes a battery case that houses battery cells, the battery case is fixed to the floor by a plurality of first fixing portions that are arranged along a first imaginary line that extends in a vehicle front-rear direction at a center of a wheel track of the vehicle, and a plurality of second fixing portions that are arranged along a second imaginary line that extends in a vehicle left-right direction at a center of an axle track of the vehicle.

2. The vehicle according to claim 1, wherein the battery pack has a pair of front-rear direction sides that extend in parallel in the vehicle front-rear direction, and a pair of left-right direction sides that extend in parallel in the vehicle left-right direction, the first imaginary line passes through a center of the battery case and extends in the vehicle front-rear direction, the second imaginary line passes through the center of the battery case and extends in the vehicle left-right direction.

3. The vehicle according to claim 1 or 2, wherein the first fixing portions are arranged at a peripheral edge of the battery case and a central portion of the battery case, and the second fixing portions are arranged at the peripheral edge of the battery case and the central portion of the battery case.

4. The vehicle according to claim 3, wherein the first fixing portions and the second fixing portions are composed of fastening link members. ​ ​ ​ ​

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