Battery unit

Abstract

To suppress damage of an electrode terminal and a bus bar in a battery module in the case of a collision.SOLUTION: A battery unit 10 is arranged to a lower side of a floor panel 9 of a vehicle 1. The battery unit comprises: a plurality of battery modules 20 that are arranged onto the lower side of the floor panel so that electrode terminals 26 and 27 are positioned to an upper surface 20a side; a bus bar 30 that connects between the electrode terminals on the upper surface side of each battery module; and a battery case 40 that houses the plurality of battery modules and the bus bar in the lower side of the floor panel. From a case inner surface 44 in an upper wall part 42a of the battery case, a head abutting rib 50 projected to a lower direction is provided. A lower end 51 of the head abutting rib does not face an electrical part A formed by the electrode terminal and the bus bar, arranged onto the upper surface side on each battery module, and faces to a non-electrical part B in which the electrode terminal and the bus bar are not arranged on the upper surface of each battery module. An interval H1 of the lower end of the head abutting rib and the non-electrical part is an interval H2 between the case inner surface and the electrical part or less.SELECTED DRAWING: Figure 8

Description

Technical Field

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[0001] The present disclosure relates to a battery unit disposed below a floor panel of a vehicle.

Background Art

[0002] In electric vehicles and hybrid vehicles, a battery unit is usually disposed below a floor panel of the vehicle. The battery unit includes a plurality of battery modules and a battery case that houses the plurality of battery modules. Each battery module is composed of a plurality of battery cells.

[0003] In order to protect the battery modules housed in the battery case from a vehicle collision, various techniques have been disclosed. For example, in the battery case fixing structure disclosed in Patent Document 1, a metal die-cast battery case (battery case) that houses a drive battery (battery module) of an electric vehicle is fixed to the lower part of a vehicle body (floor panel).

[0004] A case side wall facing the outside in the vehicle width direction of the battery case includes two fixing portions that protrude outward in the vehicle width direction and are fixed to the vehicle body, and a connecting wall that is formed in a surface shape facing the case side wall and connects the two fixing portions in the front-rear direction. The battery case also includes a rib that connects the case side wall and the connecting wall in the vehicle width direction between the two fixing portions.

[0005] According to such a configuration, when a collision load in a side collision is input to the battery case, the space surrounded by the two fixing portions, the connecting wall, and the case side wall is crushed, so that the collision energy can be effectively absorbed. Further, by reinforcing the fixing portions and the connecting wall with ribs, the side collision resistance performance can be enhanced.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Incidentally, during a head-on collision, the power unit housed in the motor compartment at the front of the vehicle pushes the dashboard panel backward, which can cause the vehicle's floor panel to be displaced downward. At this time, a downward load is applied from the floor panel to the upper wall of the battery case. Here, the area of ​​the upper wall of the battery case is usually larger than the area of ​​the side walls of the battery case.

[0008] Therefore, the upper wall of the battery case is prone to downward displacement, potentially applying a large load to the electrode terminals and busbars located on the upper side of the battery module. If a large load is applied to the electrode terminals and busbars, they may be damaged.

[0009] Furthermore, the floor panel may be displaced downwards during side or rear collisions. Therefore, the above-mentioned issues can occur not only during frontal collisions, but also during side and rear collisions.

[0010] This disclosure has been made in view of the above, and its purpose is to prevent damage to the electrode terminals and busbars located on the upper side of the battery module during a vehicle collision. [Means for solving the problem]

[0011] The battery unit according to this disclosure is a battery unit disposed on the underside of the floor panel of a vehicle, comprising: a plurality of battery modules disposed on the underside of the floor panel such that the electrode terminals are located on the upper side; bus bars connecting the electrode terminals on the upper side of the battery modules; and a battery case housing the plurality of battery modules and bus bars on the underside of the floor panel, wherein a forward-facing rib protruding downward is provided on the inner surface of the case at the upper wall of the battery case, the lower end of the forward-facing rib does not face the electrical component consisting of the electrode terminals and bus bars disposed on the upper side of the battery modules, but faces a non-electrical component on the upper surface of the battery modules where the electrode terminals and bus bars are not disposed, and the distance between the lower end of the forward-facing rib and the non-electrical component is less than or equal to the distance between the inner surface of the case and the electrical component.

[0012] With this configuration, when a vehicle is hit (especially in a head-on collision), the floor panel of the vehicle is displaced downward, and a downward load is applied from the floor panel to the upper wall of the battery case.

[0013] At this time, the lower end of the pre-contact rib that protrudes downward from the inner surface of the battery case on the upper wall of the battery case first makes contact with the non-electrical parts on the upper surface of the battery module where electrode terminals and busbars are not located.

[0014] By having the lower end of the pre-contacting rib make contact with the non-electrical components on the upper surface of the battery module first, the inner surface of the upper wall of the battery case becomes less likely to be displaced further downward, and it becomes more difficult to apply load to the electrical components, which consist of electrode terminals and busbars located on the upper side of the battery module.

[0015] This makes it possible to suppress damage to the electrode terminals and busbars located on the upper side of the battery module during a vehicle collision (especially a head-on collision).

[0016] In one embodiment, multiple pre-support ribs are provided at intervals in the vehicle width direction.

[0017] According to such a configuration, by improving the rigidity of the upper wall portion of the battery case, it is possible to suppress the displacement of the upper wall portion downward itself.

[0018] In one embodiment, rib-interconnecting reinforcing ribs are provided for connecting the abutting ribs adjacent to each other in the vehicle width direction.

[0019] According to such a configuration, by reinforcing the abutting ribs with the rib-interconnecting reinforcing ribs, the rigidity of the abutting ribs can be improved.

[0020] In one embodiment, the lower end of the rib-interconnecting reinforcing rib is located above the lower end of the abutting rib. <000**********7> According to such a configuration, the rigidity of the abutting ribs can be improved, and a space for passing a harness or the like can be formed between the lower end of the rib-interconnecting reinforcing rib and the lower ends of the abutting ribs on both sides.

[0022] In one embodiment, wall-side reinforcing ribs are provided for connecting the side wall portion of the battery case and the abutting ribs to each other.

[0023] According to such a configuration, by using the side wall portion of the battery case to reinforce the abutting ribs with the wall-side reinforcing ribs, the rigidity of the abutting ribs can be improved.

[0024] In one embodiment, the abutting rib extends in the front-rear direction.​​​​​​​In one embodiment, at least a part of the plurality of battery modules is arranged closer to the front than the rear in the front-rear direction on the lower side of the floor panel, and the lower end of the abutting rib faces the non-electrical equipment portion on the upper surface of the battery module arranged closer to the front.

[0027] During a frontal collision of the vehicle, a portion closer to the front than the rear in the front-rear direction of the floor panel is likely to be displaced downward. That is, a load from the floor panel is likely to be input to the battery module arranged closer to the front on the lower side of the floor panel via the upper wall portion of the battery case.

[0028] According to such a configuration, the abutting rib is arranged closer to the front so as to correspond to the battery module arranged closer to the front. Thereby, the electrode terminals and bus bars arranged on the upper surface side of the battery module closer to the front where the load is likely to be input can be preferentially protected.

[0029] In one embodiment, the battery module is provided with a binding bar for suppressing the expansion of the battery module, the binding bar is included in the non-electrical equipment portion, and the lower end of the abutting rib faces the binding bar.

[0030] According to such a configuration, a highly rigid binding bar for suppressing the expansion of the battery module can also function as a non-electrical equipment portion that contacts the abutting rib.

Advantages of the Invention

[0031] According to the present disclosure, it is possible to suppress damage to the electrode terminals and bus bars arranged on the upper surface side of the battery module during a collision of the vehicle.

Brief Description of the Drawings

[0032] [Figure 1] FIG. 1 shows a plan view of a vehicle equipped with a battery unit according to an embodiment of the present disclosure as viewed from below. [Figure 2]Figure 2 shows a side cross-sectional view of the vehicle on the II-II line. [Figure 3] Figure 3 shows the battery unit in a perspective view. [Figure 4] Figure 4 shows a perspective view of the battery unit with the upper case removed. [Figure 5] Figure 5 shows a perspective view of the battery module. [Figure 6] Figure 6 shows a perspective view of the upper battery case, seen from below. [Figure 7] Figure 7 shows a front cross-sectional view of the battery unit along line VII-VII. [Figure 8] Figure 8 is an enlarged view of section VIII in Figure 7. [Modes for carrying out the invention]

[0033] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended in any way to limit the present disclosure, its applications or uses.

[0034] (Vehicle configuration) Figure 1 shows a plan view of vehicle 1 seen from below. Figure 2 shows a side cross-section of vehicle 1 along line II-II. In the following explanation, the longitudinal direction (direction of travel) of vehicle 1 is simply referred to as the "longitudinal direction". The front of vehicle 1 is simply referred to as the "front side", and the rear of vehicle 1 is simply referred to as the "rear side". The left side of vehicle 1 as seen from the driver's perspective in the vehicle width direction is simply referred to as the "left side", and the right side of vehicle 1 as seen from the driver's perspective in the vehicle width direction is simply referred to as the "right side". The vertical direction (vehicle height direction) of vehicle 1 is simply referred to as the "vertical direction". The top of vehicle 1 is simply referred to as the "top side", and the bottom of vehicle 1 is simply referred to as the "bottom side".

[0035] Vehicle 1 is an electric vehicle employing a range extender. As shown in Figure 1, the motor room (engine room) 2 at the front of Vehicle 1 houses, from left to right, an engine 4, a generator 3, a reduction gear 5, and a motor 6, arranged in the width direction of the vehicle. Reference numeral 4a indicates the oil pan of engine 4. The generator 3, engine 4, reduction gear 5, and motor 6 constitute the power unit of Vehicle 1. Although not shown, an inverter may also be housed in the motor room 2.

[0036] As shown in Figure 2, a dash panel 8 is provided at the rear of the motor room 2, separating the motor room 2 from the passenger compartment 7. A battery unit 10 is located beneath the floor panel 9 that forms the floor of the passenger compartment 7. Details of the battery unit 10 will be described later.

[0037] Vehicle 1 is powered by motor 6. The input shaft of the reduction gear 5 and the output shaft of motor 6 are connected to each other. The driving force of motor 6 is reduced in rotational speed by the reduction gear 5 before being output and transmitted to the front wheels. The electricity to drive motor 6 is stored in battery unit 10.

[0038] The input shaft of the generator 3 and the output shaft of the engine 4 are connected to each other. Power is generated in the generator 3 by the drive of the engine 4. The power generated in the generator 3 is supplied to the battery unit 10 and stored in the battery unit 10, or it is supplied to the motor 6 and drives the motor 6. This extends the driving range of the vehicle 1. Note that the engine 4 is not directly used to propel the vehicle 1.

[0039] Although not shown in the diagram, engine 4 is equipped with an intake system. The intake system introduces intake air into engine 4. An air cleaner is installed in the intake system to remove foreign matter contained in the intake air.

[0040] As shown in Figures 1 and 2, the engine 4 is equipped with an exhaust system 11. The exhaust system 11 discharges exhaust gas from the engine 4 to the outside of the vehicle. The exhaust system 11 includes a first exhaust pipe 11a, a silencer 11b, and a second exhaust pipe 11c.

[0041] The first exhaust pipe 11a is connected to the front of the engine 4, bypasses the left side of the engine 4 and extends to the rear of the engine 4, then crosses the front of the dash panel 8 and extends downward. A catalytic converter or pre-silencer may be provided along the first exhaust pipe 11a.

[0042] The silencer 11b is connected downstream of the first exhaust pipe 11a. The silencer 11b reduces exhaust noise. The silencer 11b is located below the floor panel 9 and in front of the battery unit 10. The second exhaust pipe 11c is connected downstream of the silencer 11b and extends rearward, bypassing the right side of the battery unit 10.

[0043] As shown by the arrows in Figure 2, when a load is applied to vehicle 1 from the front during a head-on collision, the power units 3, 4, 5, and 6 housed in the motor room 2 may push the dash panel 8 backward. In particular, the first exhaust pipe 11a connected to the engine 4 is close to the dash panel 8 and is therefore likely to come into contact with it. As the dash panel 8 is pushed backward, the floor panel 9 is displaced downward.

[0044] As mentioned above, since the battery unit 10 is located on the underside of the floor panel 9 of vehicle 1, it is necessary to protect the battery unit 10 from downward displacement of the floor panel 9.

[0045] (Battery unit) The battery unit 10 will now be described in detail. Figure 3 shows a perspective view of the battery unit 10. Figure 4 shows a perspective view of the battery unit 10 with the upper case 42, which will be described later, removed. The battery unit 10 comprises a plurality of battery modules 20, a bus bar 30, and a battery case 40.

[0046] (Battery module) As shown in Figure 4, the battery modules 20 are arranged in a row of four in the width direction of the vehicle and two in the front-to-back direction, i.e., 4 x 2 = 8 in total. Each battery module 20 is located on the underside of the floor panel 9 (see Figure 2).

[0047] As shown in Figure 4, each battery module 20 is formed in a roughly rectangular parallelepiped shape with the length in the front-to-back direction. Each battery module 20 has a plurality of battery cells 21 (see Figure 2) arranged side by side in the front-to-back direction. Each battery cell 21 is, for example, a lithium-ion battery.

[0048] In the eight battery modules 20, the first one from the left in the front row is designated as the first battery module 20A, the first one from the left in the back row is designated as the second battery module 20B, the second one from the left in the back row is designated as the third battery module 20C, the second one from the left in the front row is designated as the fourth battery module 20D, the third one from the left in the front row is designated as the fifth battery module 20E, the third one from the left in the back row is designated as the sixth battery module 20F, the fourth one from the left in the back row is designated as the seventh battery module 20G, and the fourth one from the left in the front row is designated as the eighth battery module 20H.

[0049] As shown by the arrows in Figure 4, each battery module 20 is connected in series in the following order: 1st battery module 20A, 2nd battery module 20B, 3rd battery module 20C, 4th battery module 20D, 5th battery module 20E, 6th battery module 20F, 7th battery module 20G, and 8th battery module 20H.

[0050] Each battery module 20 is spaced apart from the others. In particular, a large gap S1 is formed between the front row of battery modules 20 (20A, 20D, 20E, 20H) and the back row of battery modules 20 (20B, 20C, 20F, 20G).

[0051] Furthermore, a large gap S2 is formed between the second battery module 20 from the left (20C, 20D) and the third battery module 20 from the left (20E, 20F). The harness 12 extends in the front-to-back direction through the gap S2.

[0052] Figure 5 shows a perspective view of the battery module 20. In Figure 5, the fourth battery module 20D is shown as an example. In this battery module 20, each battery cell 21 is covered from both the front and rear sides by end plates 22.

[0053] Two bind bars 23 are provided on both sides in the vehicle width direction of each battery cell 21 in the battery module 20. Each bind bar 23 is formed in a roughly U-shape with a cross-section that opens inward in the vehicle width direction and extends in the front-rear direction. The bind bars 23 are made of high-rigidity steel such as high-tensile steel.

[0054] The two bind bars 23 cover each battery cell 21 and end plate 22 from both sides in the vehicle width direction. Each bind bar 23 is fixed to the vehicle width direction side of the end plate 22 by bolts 24. The two bind bars 23 are there to prevent the battery module 20 from expanding as each battery cell 21 is charged and discharged.

[0055] As shown in Figure 5, in the battery module 20, each battery cell 21 is covered from above by a top plate 25. The battery module 20 is provided with a positive electrode terminal 26 and a negative electrode terminal 27 as electrode terminals. The positive electrode terminal 26 and the negative electrode terminal 27 (electrode terminals) are located on the upper surface 20a side of the battery module 20. "Upper surface 20a of the battery module 20" refers to the surface of the battery module 20 that faces upward.

[0056] In detail, the positive terminal 26 and the negative terminal 27 (electrode terminals) are fixed to the top plate 25. The positive terminal 26 and the negative terminal 27 are electrically connected to each battery cell 21.

[0057] The positive terminal 26 is located at one end of the battery module 20 in the longitudinal direction (front-to-back direction) on the upper surface 20a side. The negative terminal 27 is located at the other end of the battery module 20 in the longitudinal direction (front-to-back direction) on the upper surface 20a side.

[0058] As shown in Figure 4, in the first battery module 20 from the left (20A, 20B) and the third battery module 20 from the left (20E, 20F), the positive terminal 26 is located on the front side, while the negative terminal 27 is located on the rear side. In the second battery module 20 from the left (20C, 20D) and the fourth battery module 20 from the left (20G, 20H), the positive terminal 26 is located on the rear side, while the negative terminal 27 is located on the front side.

[0059] As shown in Figure 2, some of the battery modules 20, specifically the front row of battery modules 20 (20A, 20D, 20E, 20H), are positioned closer to the front than the rear in the front-to-back direction on the underside of the floor panel 9. More specifically, the front row of battery modules 20 (20A, 20D, 20E, 20H) are positioned in front of the center in the front-to-back direction on the underside of the floor panel 9.

[0060] Although not shown in Figure 2, the rear row of battery modules 20 (20B, 20C, 20F, 20G) is positioned towards the rear of the floor panel 9, rather than towards the front in the front-to-back direction. More specifically, the rear row of battery modules 20 (20B, 20C, 20F, 20G) is positioned behind the center of the floor panel 9 in the front-to-back direction, rather than towards the rear.

[0061] (Bus bar) As shown in Figure 4, the busbar 30 connects the electrode terminals 26 and 27 of two adjacent battery modules 20 in the series direction. The busbar 30 consists of two external busbars 31, four short busbars 32, two medium busbars 33, and two long busbars 34.

[0062] One external busbar 31 connects the positive terminal 26 of the first battery module 20A to an inverter (not shown). The other external busbar 31 connects the negative terminal 27 of the eighth battery module 20H to an inverter. In other words, the two external busbars 31 connect the positive terminal 26 of the first battery module 20A and the negative terminal 27 of the eighth battery module 20H via the inverter.

[0063] The four short busbars 32 connect the negative terminal 27 of the first battery module 20A to the positive terminal 26 of the second battery module 20B, the negative terminal 27 of the third battery module 20C to the positive terminal 26 of the fourth battery module 20D, the negative terminal 27 of the fifth battery module 20E to the positive terminal 26 of the sixth battery module 20F, and the negative terminal 27 of the seventh battery module 20G to the positive terminal 26 of the eighth battery module 20H.

[0064] Each short busbar 32 is not located on the upper surface 20a side of each battery module 20. Specifically, each short busbar 32 starts from the negative terminal 27 of the upstream battery module 20, extends downward along the front-to-back side surface, and then extends through the gap S1 in the front-to-back direction. Then, each short busbar 32 extends upward along the front-to-back side surface of the downstream battery module 20 to reach the positive terminal 26.

[0065] As an example, the short busbar 32 starts from the negative terminal 27 of the first battery module 20A, extends downward along the rear surface, then extends rearward through the gap S1, and extends upward along the front surface of the second battery module 20B to reach the positive terminal 26.

[0066] Each intermediate bus bar 33 connects the electrode terminals 26 and 27 on the upper surface 20a side of each battery module 20. Each intermediate bus bar 33 extends in the vehicle width direction so as to straddle the upper surface 20a side of two adjacent battery modules 20 in the vehicle width direction.

[0067] Specifically, one central busbar 33 connects the negative terminal 27 of the second battery module 20B to the positive terminal 26 of the third battery module 20C. The other central busbar 33 connects the negative terminal 27 of the sixth battery module 20F to the positive terminal 26 of the seventh battery module 20G.

[0068] In detail, one of the central busbars 33 starts from the negative terminal 27 of the second battery module 20B, extends to the right in the vehicle width direction, straddling the upper surface 20a of the second battery module 20B and the upper surface 20a of the third battery module 20C, and then reaches the positive terminal 26 of the third battery module 20C.

[0069] The other central busbar 33 starts from the negative terminal 27 of the sixth battery module 20F, extends to the right in the vehicle width direction, straddling the upper surface 20a of the sixth battery module 20F and the upper surface 20a of the seventh battery module 20G, and then reaches the positive terminal 26 of the seventh battery module 20G.

[0070] Each intermediate bus bar 33 is positioned at the rear end of the upper surface 20a side of the rear row battery modules 20 (20B, 20C, 20F, 20G).

[0071] The two long busbars 34 form a set and connect the electrode terminals 26 and 27 on the upper surface 20a side of each battery module 20. Specifically, the two long busbars 34 connect the negative terminal 27 of the fourth battery module 20D and the positive terminal 26 of the fifth battery module 20E.

[0072] In detail, one long busbar 34 starts from the negative terminal 27 of the fourth battery module 20D and extends rearward, straddling the upper surface 20a of the fourth battery module 20D and the upper surface 20a of the third battery module 20C. The other long busbar 34 starts from the positive terminal 26 of the fifth battery module 20E and extends rearward, straddling the upper surface 20a of the fifth battery module 20E and the upper surface 20a of the sixth battery module 20F.

[0073] Here, a pair of connection terminals 35 are positioned at locations corresponding to the rear ends of the rear row battery modules 20 (20B, 20C, 20F, 20G) in the gap S2. The rear end of one long busbar 34 is connected to one connection terminal 35. The rear end of the other long busbar 34 is connected to the other connection terminal 35. One connection terminal 35 and the other connection terminal 35 are connected to each other.

[0074] In this way, the two long busbars 34 connect the negative terminal 27 of the fourth battery module 20D and the positive terminal 26 of the fifth battery module 20E via a pair of connection terminals 35 on the upper surface 20a side of the third battery module 20C, the upper surface 20a side of the fourth battery module 20D, the upper surface 20a side of the fifth battery module 20E, and the upper surface 20a side of the sixth battery module 20F.

[0075] (Battery case) The battery case 40 is located on the underside of the floor panel 9 (see Figure 2). The battery case 40 houses multiple battery modules 20 and busbars 30 on the underside of the floor panel 9. As shown in Figure 3, the battery case 40 has a two-part structure, consisting of a lower case 41 and an upper case 42. The battery case 40 is formed in a roughly rectangular parallelepiped shape. The battery case 40 is long in the longitudinal direction, the vehicle width direction, and the vertical direction. The lower case 41 and the upper case 42 are flange-connected via bolts 43. The lower case 41 and the upper case 42 are made of resin.

[0076] As shown in Figure 4, the lower case 41 includes a substantially rectangular lower wall portion 41a that covers the multiple battery modules 20 from below, and side wall portions 41b that extend upward from the periphery of the lower wall portion 41a and cover the multiple battery modules 20 from the front, back, left, and right. The lower case 41 is substantially box-shaped with an opening on the top. The short busbar 32 mentioned above extends along the lower wall portion 41a of the lower case 41.

[0077] As shown in Figure 3, the upper case 42 includes a substantially rectangular upper wall portion 42a that covers the multiple battery modules 20 from above, and front, rear, left, and right side wall portions 42b that extend downward from the periphery of the upper wall portion 42a. The upper case 42 is substantially box-shaped with an opening on the bottom.

[0078] The area of ​​the upper wall portion 42a of the battery case 40 is larger than the area of ​​the side walls 41b and 42b of the battery case 40. Also, the battery case 40 is made of resin. For this reason, the upper wall portion 42a of the battery case 40 is easily displaced downwards.

[0079] (Pre-applied rib) Figure 6 shows a perspective view of the upper case 42 of the battery case 40, viewed from below. Multiple front ribs 50 protruding downward are provided on the inner surface 44 of the upper wall portion 42a of the upper case 42 of the battery case 40 (the lower surface of the upper wall portion 42a).

[0080] The front support rib 50 is positioned on the inner surface 44 of the upper wall 42a of the battery case 40, closer to the front than the rear in the front-to-back direction, so as to correspond to the front row of battery modules 20 (20A, 20D, 20E, 20H). More specifically, the front support rib 50 is positioned on the inner surface 44 of the upper wall 42a of the battery case 40, closer to the front than the center in the front-to-back direction.

[0081] The front support rib 50 does not correspond to the rear row of battery modules 20 (20B, 20C, 20F, 20G), and is not positioned further back than the front in the front-to-back direction on the inner surface 44 of the case of the upper wall portion 42a of the battery case 40. More specifically, the front support rib 50 is not positioned further back than the center in the front-to-back direction on the inner surface 44 of the case of the upper wall portion 42a of the battery case 40.

[0082] As shown in Figure 6, multiple front ribs 50 are provided at intervals in the vehicle width direction. Specifically, eight front ribs 50 are arranged in the vehicle width direction. Each front rib 50 extends in the front-rear direction. As will be described in detail later, the lower end 51 of the front rib 50 faces the upper surface 20a of the battery module 20.

[0083] Figure 7 shows a front cross-sectional view of the battery unit 10 along line VII-VII. The first front rib 50A, the first from the left, corresponds to the left end of the first battery module 20A. The second front rib 50B, the second from the left, corresponds to the right end of the first battery module 20A. The third front rib 50C, the third from the left, corresponds to the left end of the fourth battery module 20D. The fourth front rib 50D, the fourth from the left, corresponds to the right end of the fourth battery module 20D.

[0084] The fifth rib from the left, the fifth anti-point rib 50E, corresponds to the left end of the fifth battery module 20E. The sixth rib from the left, the sixth anti-point rib 50F, corresponds to the right end of the fifth battery module 20E. The seventh rib from the left, the seventh anti-point rib 50G, corresponds to the left end of the eighth battery module 20H. The eighth rib from the left, the eighth anti-point rib 50H, corresponds to the right end of the eighth battery module 20H.

[0085] As shown in Figures 6 and 7, between the second and third front ribs 50B and 50C that are adjacent to each other in the vehicle width direction, there are multiple first rib reinforcing ribs 61 that connect the second and third front ribs 50B and 50C to each other.

[0086] Similarly, between the sixth and seventh front ribs 50F and 50G, which are adjacent to each other in the vehicle width direction, a plurality of first inter-rib reinforcing ribs 61 are provided, connecting the sixth and seventh front ribs 50F and 50G to each other. The plurality of first inter-rib reinforcing ribs 61 are arranged in the front-rear direction.

[0087] As shown in Figures 6 and 7, the distance between the fourth pre-support rib 50D and the fifth pre-support rib 50E is greater than the distance between the second pre-support rib 50B and the third pre-support rib 50C, and the distance between the sixth pre-support rib 50F and the seventh pre-support rib 50G.

[0088] Between the fourth and fifth front ribs 50D and 50E, which are adjacent to each other in the vehicle width direction, there are multiple second inter-rib reinforcing ribs 62 that connect the fourth and fifth front ribs 50D and 50E to each other. The multiple second inter-rib reinforcing ribs 62 are arranged in the front-to-back direction.

[0089] Figure 8 is an enlarged view of section VIII in Figure 7. As shown in Figure 8, the lower end 62a of the second inter-rib reinforcing rib 62 is located above the lower end 51 of the fourth pre-support rib 50D. Similarly, the lower end 62a of the second inter-rib reinforcing rib 62 is located above the lower end 51 of the fifth pre-support rib 50E.

[0090] As shown in Figure 6, multiple auxiliary ribs 63 are provided in the front-to-rear direction on the inner surface of the fourth front rib 50D and the inner surface of the fifth front rib 50E in the vehicle width direction. In addition, the fourth front rib 50D and the fifth front rib 50E are partially missing in the front-to-rear direction.

[0091] As shown in Figure 7, a plurality of wall-side reinforcing ribs 64 are provided between the side wall portion 42b and the first front rib 50A in the upper case 42 of the battery case 40, connecting the side wall portion 42b and the first front rib 50A to each other.

[0092] Similarly, between the side wall portion 42b and the eighth front rib 50H in the upper case 42 of the battery case 40, a plurality of wall-side reinforcing ribs 64 are provided, connecting the side wall portion 42b and the eighth front rib 50H to each other. As shown in Figure 6, the plurality of wall-side reinforcing ribs 64 are arranged in the front-rear direction.

[0093] As shown in Figure 8, the lower end 51 of the front rib 50 does not face the electrical component A, which consists of electrode terminals 26, 27 and busbar 30 located on the upper surface 20a side of the battery module 20. The lower end 51 of the front rib 50 faces the non-electrical component B on the upper surface 20a of the battery module 20, where the electrode terminals 26, 27 and busbar 30 are not located.

[0094] Here, the upper end of the bind bar 23 constitutes the upper surface 20a of the battery module 20. The bind bar 23 is included in the non-electrical section B. More specifically, the lower end 51 of the front rib 50 faces the bind bar 23 as part of the non-electrical section B.

[0095] More specifically, the lower end 51 of the front rib 50 faces the bind bar 23, which is a non-electrical component B, on the upper surface 20a of the battery modules 20 located towards the front, i.e., the front row of battery modules 20 (20A, 20D, 20E, 20H).

[0096] The distance H1 between the lower end 51 of the pre-applied rib 50 and the non-electrical component B (specifically, the upper surface of the bind bar 23) on the upper surface 20a of the battery module 20 is smaller than the distance H2 between the inner surface 44 of the case on the upper wall portion 42a of the battery case 40 and the electrical component A (specifically, the upper surfaces of the electrode terminals 26, 27 and the upper surface of the bus bar 30) located on the upper surface 20a side of the battery module 20.

[0097] (Effects and Benefits) According to this embodiment, when the vehicle 1 is involved in a collision (especially a head-on collision), the floor panel 9 of the vehicle 1 is displaced downward, and a downward load is applied from the floor panel 9 to the upper wall portion 42a of the battery case 40.

[0098] At this time, the lower end 51 of the pre-contact rib 50 that protrudes downward from the inner surface 44 of the case on the upper wall portion 42a of the battery case 40 first makes contact with the non-electrical portion B on the upper surface 20a of the battery module 20 where the electrode terminals 26, 27 and busbar 30 are not located.

[0099] The lower end 51 of the pre-contact rib 50 makes contact first with the non-electrical part B on the upper surface 20a of the battery module 20, which makes it difficult for the inner surface 44 of the case on the upper wall 42a of the battery case 40 to be displaced further downward, and also makes it difficult to apply load to the electrical part A, which consists of electrode terminals 26, 27 and busbar 30 located on the upper surface 20a side of the battery module 20.

[0100] This makes it possible to suppress damage to the electrode terminals 26, 27 and busbar 30 located on the upper surface 20a side of the battery module 20 when the vehicle 1 collides (especially in a head-on collision).

[0101] In particular, this is advantageous in suppressing fires and short circuits caused by damage to the electrode terminals 26, 27 and the busbar 30.

[0102] Since multiple pre-supporting ribs 50 are provided at intervals in the vehicle width direction, the rigidity of the upper wall portion 42a of the battery case 40 can be improved. This makes it possible to suppress the downward displacement of the upper wall portion 42a of the battery case 40.

[0103] By reinforcing the pre-support rib 50 with the first inter-rib reinforcing rib 61 and the second inter-rib reinforcing rib 62, the rigidity of the pre-support rib 50 can be improved.

[0104] In this embodiment, the lower end 62a of the second inter-rib reinforcing rib 62 is located above the lower end 51 of the fourth pre-support rib 50D and the lower end 51 of the fifth pre-support rib 50E.

[0105] This allows the rigidity of the fourth and fifth pre-support ribs 50D and 50E to be improved by the second inter-rib reinforcing rib 62, and also creates a space U for passing the harness 12 between the lower end 62a of the second inter-rib reinforcing rib 62 and the lower ends 51 of the fourth and fifth pre-support ribs 50D and 50E on both sides.

[0106] By utilizing the side wall portion 42b of the upper case 42 of the battery case 40 and reinforcing the first front rib 50A and the eighth front rib 50H with the wall-side reinforcing rib 64, the rigidity of the first front rib 50A and the eighth front rib 50H can be improved.

[0107] Since the front rib 50 extends in the front-rear direction, the rigidity of the upper wall portion 42a of the battery case 40 can be uniformly improved in the front-rear direction. This makes it possible to suppress localized downward displacement of the upper wall portion 42a of the battery case 40.

[0108] During a head-on collision involving vehicle 1, the portion of the floor panel 9 closer to the front than the rear in the longitudinal direction is more likely to be displaced downwards. In other words, the battery modules 20 located towards the front on the underside of the floor panel 9, specifically the front row of battery modules 20 (20A, 20D, 20E, 20H), are more likely to receive loads from the floor panel 9 via the upper wall portion 42a of the battery case 40.

[0109] Therefore, the front rib 50 is positioned towards the front on the inner surface 44 of the upper wall 42a of the battery case 40, corresponding to the battery modules 20 (20A, 20D, 20E, 20H) located towards the front (front row).

[0110] This allows for preferential protection of the electrode terminals 26, 27 and busbars 30 located on the upper surface 20a side of the battery modules 20 (20A, 20D, 20E, 20H) that are closer to the front (front row) and are more susceptible to load input.

[0111] Furthermore, since the middle busbar 33 is located at the rear end of the upper surface 20a side of the rear row battery modules 20 (20B, 20C, 20F, 20G) (corresponding to the rear of the floor panel 9), it is unlikely to be subjected to load input from the floor panel 9. For this reason, no special measures are required to suppress the input of load from the floor panel 9 to the middle busbar 33.

[0112] The highly rigid bind bar 23, which suppresses the expansion of the battery module 20, can also function as a non-electrical component B that contacts the pre-applied rib 50.

[0113] (Other embodiments) Although this disclosure has been described above with reference to preferred embodiments, this description is not limiting, and various modifications are, of course, possible.

[0114] The distance H1 between the lower end 51 of the pre-support rib 50 and the non-electrical component B on the upper surface 20a of the battery module 20 may be the same as the distance H2 between the inner surface 44 of the upper wall 42a of the battery case 40 and the electrical component A located on the upper surface 20a side of the battery module 20. In other words, the distance H1 between the lower end 51 of the pre-support rib 50 and the non-electrical component B should be less than or equal to the distance H2 between the inner surface 44 of the case and the electrical component A.

[0115] The lower end 51 of the pre-applied rib 50 may face the upper surface of the top plate 25, which is a non-electrical component B, rather than facing the bind bar 23, which is a non-electrical component B.

[0116] The non-electrical portion B on the upper surface 20a of the battery module 20 may be provided with a protrusion that projects upward and faces the lower end 51 of the front rib 50 in order to reduce the distance H1 between it and the lower end 51 of the front rib 50. Furthermore, the distance H1 between at least a part of the non-electrical portion B (for example, the above-mentioned protrusion) and the lower end 51 of the front rib 50 should be less than or equal to the distance H2 between the electrical portion A and the inner surface 44 of the case.

[0117] The front support rib 50 may extend in the vehicle width direction rather than in the front-to-back direction. Also, the front support rib 50 may be a long, rod-shaped structure extending downwards.

[0118] All battery modules 20 may be positioned closer to the front than the rear in the front-to-back direction on the underside of the floor panel 9.

[0119] Vehicle 1 does not need to be equipped with a generator 3 and an engine 4.

[0120] Furthermore, the floor panel 9 may also be displaced downwards during side or rear collisions. Therefore, the battery unit 10 according to this embodiment may be effective not only during frontal collisions, but also during side and rear collisions. [Industrial applicability]

[0121] This disclosure is extremely useful and has high industrial applicability because it can be applied to battery units. [Explanation of symbols]

[0122] A. Electrical section B Non-electrical parts H1 interval H2 interval U space 1 vehicle 2 Motor Room 4 engines 6 motors 7 Cabin 8. Dashboard 9 Floor Panels 10 Battery Units 11 Exhaust system 12 Harnesses 20 Battery Modules 20a top surface 21 battery cells 23 Bind Bar 25 Top Plate 26 Positive terminal (electrode terminal) 27 Negative terminal (electrode terminal) 30 Bus Bar 33 Middle Bus Bar 34 Long bus bar 40 Battery Case 41 Lower case 42 Upper case 42a Upper wall 42b Side wall part 44 Inside of the case 50 Pre-applied ribs 51 Bottom end 61 Reinforcement ribs between the first ribs 62 Reinforcement ribs between the second ribs 62a bottom end 64 Wall-side reinforcing ribs

Claims

1. A battery unit located on the underside of the vehicle's floor panel, Multiple battery modules are arranged on the underside of the floor panel such that the electrode terminals are located on the upper side, On the upper side of the battery module, a busbar connects the electrode terminals, The floor panel is located below the aforementioned floor panel and includes a battery case that houses the plurality of battery modules and busbars, A front rib protruding downward is provided on the inner surface of the upper wall portion of the battery case. The lower end of the aforementioned pre-applying rib does not face the electrical component consisting of the electrode terminals and busbars located on the upper surface side of the battery module, but faces the non-electrical component on the upper surface of the battery module where the electrode terminals and busbars are not located. A battery unit in which the distance between the lower end of the pre-applied rib and the non-electrical component is less than or equal to the distance between the inner surface of the case and the electrical component.

2. The battery unit according to claim 1, The aforementioned pre-applied ribs are arranged in multiples at intervals in the vehicle width direction, forming a battery unit.

3. The battery unit according to claim 2, A battery unit is provided with inter-rib reinforcing ribs that connect to each other the aforementioned pre-applied ribs that are adjacent to each other in the vehicle width direction.

4. The battery unit according to claim 3, The lower end of the inter-rib reinforcing rib is located above the lower end of the pre-applied rib, in the battery unit.

5. A battery unit according to any one of claims 1 to 4, A battery unit is provided with wall-side reinforcing ribs that connect the side wall portion of the battery case and the pre-applied rib to each other.

6. A battery unit according to any one of claims 1 to 5, The aforementioned pre-applied rib extends in the front-to-back direction, forming a battery unit.

7. A battery unit according to any one of claims 1 to 6, The battery module is provided with a binding bar to suppress the expansion of the battery module. The aforementioned bind bar is included in the non-electrical section, The lower end of the aforementioned pre-applied rib faces the bind bar, and is a battery unit.

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