JP2022096982A - Lower structure of electric vehicle - Google Patents

Abstract

To provide a lower structure of an electric vehicle which can suppress vertical vibration and twisting caused by an input load from a front suspension.SOLUTION: A lower structure body 4 of an electric vehicle 1 comprises: a battery case section 41 which can internally accommodate a battery unit B; a suspension frame section 42 which is disposed in a vehicle front side of the battery case part 41 and to which a pair of left and right suspension arms are attached at both sides in the vehicle width direction; and a connection section 43 which extends from a front end section 41a of the battery case section 41 towards each of the suspension arm attachment positions 42a of the suspension frame part 42 and connects together the battery case section 41 and the suspension frame section 42. The connection section 43 extends in the vehicle width direction across the width of the suspension frame section 42 in the vehicle width direction and extends in the vehicle vertical direction across the thickness of the suspension frame section 42 in the vehicle vertical direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a substructure of an electric vehicle.

Generally, an electric vehicle such as an electric vehicle is provided with a battery unit at the lower part of the vehicle. The battery unit is configured by unitizing a plurality of battery modules, and is mounted on the lower side of the floor of the vehicle interior. The battery unit is attached to a member constituting the vehicle body.

As a lower structure of a conventional electric vehicle, for example, the structure disclosed in Patent Document 1 is known. In the structure disclosed in the document, a case body having a bottom wall and a peripheral wall is arranged on the lower side of the vehicle on the vehicle interior floor, and a battery is housed inside the case body. Further, on the vehicle front side of the case body, a front extending portion is integrally formed with the case body from the peripheral wall on the vehicle front side of the case body. A pair of left and right suspension lower arms are attached to both ends of the front extension portion in the vehicle width direction.

Japanese Unexamined Patent Publication No. 2018-158688

However, with the conventional structure as described above, the load input from the front suspension to the front extension via the suspension lower arm sufficiently suppresses vertical vibration and twisting that occur in the front extension and the case body. There was a problem that it was difficult to do.

That is, in the conventional structure, the front suspension including the suspension lower arm is supported by the front extending portion. This front extending portion is originally provided on the front side of the vehicle in order to absorb the collision energy at the time of a frontal collision. Therefore, there is a possibility that the rigidity of the front extension portion is insufficient with respect to the load input from the front suspension to the front extension portion. If such a front extension is continuously provided on the case body that accommodates a heavy battery, the load from the front suspension causes a relatively large vertical movement from the front extension to the case body. There was a risk of vibration and twisting, and there was room for improvement.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substructure of an electric vehicle capable of suppressing vertical vibration and twisting caused by an input load from a front suspension. ..

In order to achieve the above object, the present invention includes a battery case portion that is arranged in the lower part of the electric vehicle, extends in the vehicle front-rear direction and the vehicle width direction, and can accommodate the battery unit mounted on the electric vehicle inside. Provides the undercarriage of an electric vehicle. This lower structure is arranged on the vehicle front side of the battery case portion, extends in the vehicle width direction, and has a suspension frame portion to which a pair of left and right suspension arms supporting the front suspension are attached to both side portions in the vehicle width direction. It extends from the front end portion of the battery case portion toward each suspension arm mounting portion of the suspension frame portion, and includes a connecting portion that connects the battery case portion and the suspension frame portion. The connecting portion has a portion located between the front end portion of the battery case portion and the rear end portion of the suspension frame portion extending in the vehicle width direction over the width of the suspension frame portion in the vehicle width direction. The suspension frame portion extends in the vehicle vertical direction over the thickness of the vehicle in the vehicle vertical direction.

According to the lower structure of the electric vehicle according to the present invention, a connecting portion extending over the width of the suspension frame portion in the vehicle width direction and the thickness in the vehicle vertical direction is provided between the suspension frame portion and the battery case portion. As a result, the rigidity of the lower structure is increased, so that vertical vibration and twisting caused by the input load from the front suspension can be suppressed.

It is a bottom view which looked at the front side part of the electric vehicle to which the lower structure which concerns on one Embodiment of this invention was applied seen from the lower side of the vehicle. FIG. 3 is a cross-sectional view taken along the line AA in FIG. It is an exploded perspective view which shows the specific example of the lower structure of FIG. FIG. 3 is an enlarged perspective view showing a main part of a lower member and an internal component group in the lower structure of FIG. It is an exploded perspective view which shows the other specific example of the substructure of FIG. FIG. 5 is an enlarged perspective view showing the internal structure of the connecting portion in FIG. 5.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 6 show a lower structure of an electric vehicle according to an embodiment of the present invention. In the figure, the arrow Fr direction indicates the vehicle front in the vehicle front-rear direction, the arrow U direction indicates the vehicle upper direction in the vehicle vertical direction, the arrow L direction indicates the vehicle width direction to the left, and the arrow R direction indicates the vehicle width. It shows the right side in the direction. Further, the "left and right" in the description of the embodiment correspond to the left and right when the front is viewed from the vehicle interior.

The electric vehicle 1 to which the lower structure according to the present embodiment is applied is a drive device mounted on the power unit room P at the front of the vehicle, as shown in the bottom view of FIG. 1 when the front side portion of the vehicle 1 is viewed from below. It has 2 (for example, an electric motor or the like). The drive device 2 provides power for driving the front wheels of the vehicle, for example. In the power unit room P, a pair of left and right front side members 3 which are vehicle skeleton members extend in the front-rear direction of the vehicle. At the lower part of the electric vehicle 1, as shown by a thick line in FIG. 1, a lower structure 4 including a battery case portion 41, a suspension frame portion 42, and a connecting portion 43 is provided.

The battery case portion 41 forming a part of the lower structure 4 is arranged on the vehicle rear side portion of the lower structure 4 and extends in the vehicle front-rear direction and the vehicle width direction. As shown in FIG. 2 (cross-sectional view taken along the line AA in FIG. 1), the battery case portion 41 can accommodate the battery unit B mounted on the electric vehicle 1 inside. The battery unit B is, for example, a power supply device for operating the drive device 2. Although not shown, the battery unit B has a large weight because a plurality of battery modules are unitized. The battery case portion 41 accommodating the battery unit B is arranged on the lower side of the vehicle on a floor panel (not shown) constituting the floor portion of the vehicle compartment.

The suspension frame portion 42 is arranged on the vehicle front side of the battery case portion 41, and constitutes the vehicle front side portion of the lower structure 4. The suspension frame portion 42 extends in the vehicle width direction and is located at the lower part of the power unit room P. A pair of left and right suspension arms that support a front suspension (not shown) are attached to both sides of the suspension frame portion 42 in the vehicle width direction. That is, the suspension arm mounting portion 42a (FIG. 1) of the suspension frame portion 42 is located on the left side portion and the right side portion of the vehicle front side portion in the lower structure 4. The suspension frame portion 42 is attached to the lower part of the left and right front side members 3.

The connecting portion 43 extends from the front end portion 41a of the battery case portion 41 toward each suspension arm mounting portion 42a of the suspension frame portion 42, and connects the battery case portion 41 and the suspension frame portion 42. The portion of the connecting portion 43 located between the front end portion 41a of the battery case portion 41 and the rear end portion 42b of the suspension frame portion 42 extends in the vehicle width direction over the width of the suspension frame portion 42 in the vehicle width direction. (FIG. 1), the suspension frame portion 42 extends in the vehicle vertical direction over the thickness of the vehicle vertical direction (FIG. 2).

Hereinafter, a specific example of the lower structure 4 according to the present embodiment will be described in detail.
FIG. 3 is a perspective view showing the components in the specific example of the lower structure 4 in an exploded manner. Further, FIG. 4 is an enlarged perspective view showing the main parts of the lower member 6 and the internal component group 7 in the lower structure 4 of FIG.

In FIGS. 3 and 4, the lower structure 4 according to the above specific example is the upper member 5 arranged on the upper side of the vehicle, the lower member 6 arranged on the lower side of the vehicle, and the upper member 5 and the lower member 6. It includes an internal component group 7 arranged between them. The space formed between the upper member 5 and the lower member 6 is divided into a plurality of regions by the combination of the uneven shape of each of the upper member 5 and the lower member 6 and the internal component group 7. As a result, the lower structure 4 is integrally formed with the battery case portion 41, the suspension frame portion 42, and the connecting portion 43 described above. In other words, in the lower structure 4 of the present embodiment, a box structure including a battery case portion 41, a suspension frame portion 42, and a connecting portion 43 is provided by combining the upper member 5, the lower member 6, and the internal component group 7. Is formed.

Specifically, as shown in FIGS. 2 and 3, the upper member 5 is formed by joining a plurality of plate-shaped parts 5a, and extends in the vehicle front-rear direction and the vehicle width direction as a whole. The rear portion 51 of the upper member 5 forms the upper portion of the battery case portion 41 described above. The rear portion 51 (upper portion of the battery case portion 41) of the upper member 5 is substantially rectangular in a plan view and is formed in a box shape open to the lower side of the vehicle. The rear portion 51 is provided with a flange portion 51a protruding outward from the opening (FIG. 3). The front end portion 51b of the rear portion 51 has an intermediate portion in the vehicle width direction protruding toward the front side of the vehicle from both end portions. On the lower surface side of the rear portion 51, irregularities corresponding to the arrangement of the internal component group 7 may be formed.

The front portion 52 of the upper member 5 forms the upper portion of the suspension frame portion 42 described above. The front portion 52 (upper part of the suspension frame portion 42) of the upper member 5 extends in the vehicle width direction, and both ends in the vehicle width direction protrude in the vehicle front-rear direction, respectively, and is formed in a substantially H shape in a plan view. Has been done. The upper portions of the pair of left and right suspension arms are attached to the left and right side portions 52a of the front portion 52, respectively. Recesses 52b for attaching the vehicle body connecting parts 72a, which will be described later, of the internal parts group 7 are provided near the center of the left and right side portions 52a of the front portion 52 in the vehicle front-rear direction.

The intermediate portion 53 located between the rear portion 51 and the front portion 52 of the upper member 5 forms the upper portion of the above-mentioned connecting portion 43. The intermediate portion 53 (upper part of the connecting portion 43) of the upper member 5 extends from the front end portion 51b of the rear portion 51 to the rear end portion 52c of the front portion 52, and the intermediate portion in the vehicle width direction protrudes toward the front of the vehicle from both end portions. ing. Further, as shown in FIG. 2, the intermediate portion 53 has an inclined surface 53a inclined upward in the vehicle toward the rear of the vehicle.

As shown in FIGS. 1 to 4, the lower member 6 is formed by joining a plurality of plate-shaped parts 6a, and extends in the vehicle front-rear direction and the vehicle width direction as a whole. The rear portion 61 of the lower member 6 forms the lower portion of the battery case portion 41 described above. The rear portion 61 (lower portion of the battery case portion 41) of the lower member 6 is substantially rectangular in a plan view and is formed in a box shape open above the vehicle. As shown in FIGS. 3 and 4, the rear portion 61 is provided with a flange portion 61a protruding outward from the opening. The flange portion 61a is joined to the flange portion 51a of the rear portion 51 of the upper member 5 described above by using a bolt or the like. The front end portion 61b of the rear portion 61 has an intermediate portion in the vehicle width direction protruding toward the front side of the vehicle from both end portions. A reinforcing member 61c extending in the front-rear direction of the vehicle is joined to the lower outer side of the left and right side walls in the box shape of the rear portion 61 of the lower member 6 (FIG. 3). The reinforcing member 61c is attached to a vehicle skeleton member such as a side sill (not shown).

The front portion 62 of the lower member 6 forms the lower portion of the suspension frame portion 42 described above. The front portion 62 (lower portion of the suspension frame portion 42) of the lower member 6 extends in the vehicle width direction, and both ends in the vehicle width direction protrude in the vehicle front-rear direction, respectively, and is substantially H-shaped in a plan view. It is formed. Side walls extending in the front-rear direction of the vehicle and projecting to the upper side of the vehicle are formed on the left and right side portions 62a of the front portion 62, respectively. A recess 62b for attaching the vehicle body connecting component 72a of the internal component group 7 is provided in a portion extending outward from the lower end of the side wall in the vehicle width direction. The rear end portion 62c of the front portion 62 projects upward from the vehicle. Further, the front end portion 62d of the front portion 62 also has a wall shape protruding upward from the vehicle. The lower portions of the pair of left and right suspension arms are attached to the left and right side portions 62a of the front portion 62, respectively. That is, the suspension arm mounting portion 42a (FIG. 1) of the suspension frame portion 42 described above corresponds to the left and right side portions 52a of the front portion 52 of the upper member 5 and the left and right side portions 62a of the front portion 62 of the lower member 6. ing.

The intermediate portion 63 located between the rear portion 61 and the front portion 62 of the lower member 6 forms the lower portion of the above-mentioned connecting portion 43. The intermediate portion 63 (lower portion of the connecting portion 43) of the lower member 6 extends from the front end portion 61b (front wall) of the rear portion 61 to the rear end portion 62c (rear wall) of the front portion 62, and the intermediate portion in the vehicle width direction is formed. It protrudes toward the front of the vehicle from both ends.

In the connecting portion 43 of the present embodiment, the intermediate portion 53 of the upper member 5, the intermediate portion 63 of the lower member 6, the front end portion 61b of the rear portion 61 of the lower member 6, and the front portion 62 of the lower member 6 A closed cross section extending in the vehicle width direction is formed by the rear end portion 62c.

That is, the connecting portion 43 is suspended from the upper wall portion (intermediate portion 53 of the upper member 5) extending from the upper front end of the battery case portion 41 to the upper rear end of the suspension frame portion 42 and the lower front end of the battery case portion 41. A front wall portion (lower side) connecting a lower wall portion (intermediate portion 63 of the lower member 6) extending to the lower part of the rear end of the frame portion 42, a front end of the upper wall portion, and a front end of the lower wall portion. The rear end portion 62c) of the front portion 62 of the member 6 and the rear wall portion connecting the rear end of the upper wall portion and the rear end of the lower wall portion (front end portion 61b of the rear portion 61 of the lower member 6). To form a closed cross section extending in the vehicle width direction.

In the present embodiment, the front end portion 61b of the rear portion 61 of the lower member 6 and / or the rear end portion 62c of the front portion 62 of the lower member 6 also correspond to the "standing wall portion" of the connecting portion of the present invention. ing.

As shown in FIGS. 2 to 4, the internal component group 7 includes a plurality of case frames 71a to 71d arranged between the rear portion 51 of the upper member 5 and the rear portion 61 of the lower member 6 (battery case portion 41). And a plurality of vehicle body connecting parts 72a to 72c arranged between the front portion 52 of the upper member 5 and the front portion 62 of the lower member 6 (suspension frame portion 42), and the intermediate portion 53 and the lower portion of the upper member 5. It has a plurality of partition wall parts 73a to 73e arranged between the intermediate portion 63 of the side member 6 (connecting portion 43).

Of the plurality of case frames 71a to 71d, the case frames 71a arranged on the left and right side portions inside the battery case portion 41 extend in the front-rear direction of the vehicle, respectively. Between the left and right case frames 71a, a plurality of case frames 71b extending in the vehicle width direction (here, four) are provided at intervals in the vehicle front-rear direction. Further, a case frame 71c extending in the front-rear direction of the vehicle is provided at the center in the vehicle width direction between the left and right case frames 71a.

Further, the case frame 71b located on the frontmost side of the four case frames 71b in the lateral direction is provided with three short case frames 71d extending to the front side of the vehicle (FIG. 4). These case frames 71a to 71d are used to dispose the battery unit B at a predetermined position in the battery case portion 41, and enhance the strength and rigidity of the battery case portion 41.

As shown in FIGS. 1 to 4, the vehicle body connecting parts 72a among the plurality of vehicle body connecting parts 72a to 72c have recesses 52b provided in the left and right side portions 52a of the front portion 52 of the upper member 5 and the lower side. It is attached to each of the recesses 62b provided in the left and right side portions 62a of the front portion 62 of the member 6. The left and right vehicle body connecting parts 72a extend above the vehicle and outward in the vehicle width direction from the upper surface portion (front portion 52 of the upper member 5) of the suspension frame portion 42. The upper end portions of the left and right vehicle body connecting parts 72a are attached to the lower surface portions of the left and right front side members 3 (FIG. 1).

The vehicle body connecting parts 72b are joined to the left and right of the front end portion 62d of the front portion 62 of the lower member 6, and extend in front of the vehicle and outward in the vehicle width direction, respectively. The front end portion of the vehicle body connecting component 72b is attached to the lower surface portion of the front side member 3 via the vehicle body connecting arm 8 (FIG. 1). As shown in FIG. 4, the vehicle body connecting parts 72c are fixed to the inside of the left and right side portions 62a of the front portion 62 of the lower member 6 in the vehicle width direction. The left and right vehicle body connecting parts 72c are used for attaching the left and right suspension arms.

As shown in FIGS. 3 and 4, the plurality of partition wall parts 73a to 73e have a plate-like shape extending in the front-rear direction of the vehicle, and are rear of the front end portion 61b and the front portion 62 of the rear portion 61 of the lower member 6. It is erected at a distance from the end 62c in the vehicle width direction. In other words, the partition wall parts 73a to 73e are vertical wall portions extending in the vehicle width direction of the connecting portion 43 (front end portion 61b of the rear portion 61 of the lower member 6 and / or rear end portion 62c of the front portion 62 of the lower member 6). It is provided at intervals in the vehicle width direction along the road. The upper end portions of the partition wall parts 73a to 73e are inclined upward in the vehicle toward the rear of the vehicle in accordance with the inclined surface 53a of the intermediate portion 53 of the upper member 5.

Of the partition wall parts 73a to 73e, the left and right partition wall parts 73a arranged on the outermost side in the vehicle width direction are from the front end portions of the case frames 71a arranged on the left and right in the battery case portion 41 to the suspension frame portion 42. It extends toward each suspension arm mounting location 42a. That is, the left and right partition wall parts 73a constitute the left and right outer wall portions of the connecting portion 43, each rear end portion is connected to the front end portion of the case frame 71a, and each front end portion is a suspension frame. It is connected to the left and right ends of the rear end portion 42b of the portion 42.

Further, among the partition wall parts 73a to 73e, the three partition wall parts 73b located near the center in the vehicle width direction are provided in the intermediate portion in the vehicle width direction protruding toward the front side of the vehicle in the connecting portion 43. Specifically, as shown in FIG. 4, the three partition wall parts 73b extend toward the front of the vehicle from the portion of the rear portion 61 of the lower member 6 that protrudes toward the front of the vehicle, and the respective tip portions thereof. Is in contact with a portion of the front portion 62 of the lower member 6 that protrudes toward the front of the vehicle from both ends of the rear end portion 62c in the vehicle width direction. One of the three partition wall parts 73b is arranged at the center of the connecting portion 43 in the vehicle width direction.

The left and right partition wall parts 73c located on the outer side in the vehicle width direction with respect to the three partition wall parts 73b are directed diagonally outward from the portion of the rear portion 61 of the lower member 6 on the front end portion 61b toward the vehicle front side. Each of the extended end portions is in contact with curved portions located on the left and right sides of the rear end portion 62c in the front portion 62 of the lower member 6.

Further, the left and right partition wall parts 73d located on the outer side in the vehicle width direction with respect to the partition wall component 73c extend toward the front side of the vehicle from the curved portions located on the left and right sides of the front end portion 61b in the rear portion 61 of the lower member 6. Each tip portion is in contact with straight portions located on the left and right sides of the rear end portion 62c in the front portion 62 of the lower member 6.

Further, the left and right partition wall parts 73e located on the outer side in the vehicle width direction with respect to the partition wall component 73d extend diagonally outward in front of the vehicle from the inclined portions located on the left and right sides of the front end portion 61b in the rear portion 61 of the lower member 6. , Each tip portion is in contact with the left and right ends (front ends of the left and right partition wall parts 73a) of the rear end portion 62c in the front portion 62 of the lower member 6.

Next, the operation of the substructure according to the present embodiment will be described.
In the lower structure 4 of the present embodiment as described above, the load from the left and right front suspensions of the electric vehicle 1 is applied to both sides of the suspension frame portion 42 in the vehicle width direction (each suspension arm mounting portion 42a) via the suspension arm. Each is entered. The input load to the suspension frame portion 42 is transmitted to the battery case portion 41 via the connecting portion 43, and also via the vehicle body connecting parts 72a and 72b and the vehicle body connecting arm 8 provided on the left and right sides of the suspension frame portion 42. It is transmitted to the left and right front side members 3.

At this time, the above-mentioned conventional connection portion 43 is provided between the suspension frame portion 42 and the battery case portion 41 so as to extend the width of the suspension frame portion 42 in the vehicle width direction and the thickness in the vehicle vertical direction. The rigidity of the lower structure 4 is higher than that of the structure. Further, the connecting portion 43 of the present embodiment includes an upper wall portion (intermediate portion 53 of the upper member 5), a lower wall portion (intermediate portion 63 of the lower member 6), and a front wall portion (front portion 62 of the lower member 6). The rear end portion 62c) and the rear wall portion (front end portion 61b of the rear portion 61 of the lower member 6) form a closed cross section extending in the vehicle width direction. That is, the connecting portion 43 connecting the suspension frame portion 42 and the battery case portion 41 has an integrated structure (box structure) having a closed cross section. Therefore, the connecting portion 43 has higher rigidity. As a result, the connecting portion 43 can bear a large load with respect to the input load to the suspension frame portion 42. Further, since the connecting portion 43 can transmit the load by bending, axial force, and shearing, a larger load can be transmitted to the battery case portion 41.

The battery case portion 41 is reinforced by a plurality of case frames 71a to 71d so as to be able to accommodate a heavy battery unit B, and has high rigidity. Therefore, the load transmitted from the suspension frame portion 42 to the battery case portion 41 via the connecting portion 43 is distributed by the battery case portion 41, and the vehicle frame such as a side sill is distributed via the reinforcing members 61c provided on the left and right side walls. It will be escaped to the member.

Therefore, according to the lower structure 4 of the present embodiment, vertical vibration that may occur from the suspension frame portion 42 to the battery case portion 41 when the left and right front suspensions are displaced in the same direction up and down the vehicle, and the left and right front suspensions. Can suppress the twist that may occur from the suspension frame portion 42 to the battery case portion 41 when the vehicle is displaced in different directions in the vertical direction (or the front and rear of the vehicle).

Further, in the lower structure 4 of the present embodiment, the front end portions of the case frame 71a arranged on the left and right in the battery case portion 41 and the rear ends of the outer wall portions (bulkhead parts 73a) located on the left and right of the connecting portion 43. The part is connected. As a result, when the width of the battery case portion 41 in the vehicle width direction is larger than the width of the suspension frame portion 42 in the vehicle width direction, twisting around the axis in the vehicle front-rear direction can be effectively suppressed. In particular, in the present embodiment, the connecting portion 43 forms a closed cross section extending in the vehicle width direction, and the upper wall portion (intermediate portion 53 of the upper member 5) is inclined upward in the vehicle toward the rear of the vehicle. Therefore, even when the thickness of the battery case portion 41 and the suspension frame portion 42 are different, the twist around the shaft can be suppressed more effectively.

Further, in the lower structure 4 of the present embodiment, the vertical wall portion (the front end portion 61b of the rear portion 61 of the lower member 6 and / /) in which the connecting portion 43 extends in the vehicle width direction over the width in the vehicle width direction of the suspension frame portion 42. Alternatively, it has a rear end portion 62c) of the front portion 62 of the lower member 6. As a result, the vertical wall portion of the connecting portion 43 effectively acts on the load input from diagonally forward of each suspension arm mounting portion 42a in the suspension frame portion 42, and the twist around the axis in the vertical direction of the vehicle is effective. Can be suppressed. Further, since the vertical wall portion of the connecting portion 43 protrudes forward from both end portions in the vehicle width direction in the vehicle top view, the load from the suspension frame portion 42 is transferred to the battery case portion 41 via the connecting portion 43. It can be escaped in the entire width direction of the vehicle.

Further, in the lower structure 4 of the present embodiment, a plurality of partition wall portions (bulkhead components 73b to 73e) extending in the vehicle front-rear direction inside the left and right outer wall portions (bulkhead components 73a) of the connecting portion 43 in the vehicle width direction. ) Is provided, so that the rigidity of the connecting portion 43 can be further increased. In addition, since the plurality of partition walls in the connecting portion 43 are provided at intervals along the standing wall portion extending in the vehicle width direction, the standing wall portion can be reinforced, so that the axis in the vehicle vertical direction can be reinforced. It is possible to suppress the twist around it more effectively.

Next, another specific example of the lower structure 4 according to this embodiment will be described.
In the specific example of the lower structure 4 shown in FIGS. 3 and 4 described above, a case where the lower structure 4 is integrally formed by combining the upper member 5, the lower member 6, and the internal component group 7 will be described. did. On the other hand, in another specific example shown in the exploded perspective view of FIG. 5, the battery case portion 41, the suspension frame portion 42, and the connecting portion 43'are separately configured, and they are arranged side by side in the front-rear direction of the vehicle and are arranged with each other. By joining, the substructure 4'is integrally formed.

The battery case portion 41 and the suspension frame portion 42 in the lower structure 4'are the same as in the case of the lower structure 4 described above. As shown in FIGS. 5 and 6, the connecting portion 43'of the lower structure 4'has a rear wall portion 43a that matches the shape of the front end portion 41a of the battery case portion 41 and a rear end portion 42b of the suspension frame portion 42. It has a front wall portion 43b that matches the shape of the above. The outer wall portions on the left and right sides of the connecting portion 43'and the plurality of partition walls inside the connecting portion 43'are the same as the plurality of partition wall parts 73a to 73e in the above-mentioned lower structure 4.

The front end portion 41a of the battery case portion 41 in the lower structure 4'is connected to the rear wall portion 43a of the connecting portion 43'by welding or bolts or the like. Further, the rear end portion 42b of the suspension frame portion 42 in the lower structure 4'is also connected to the front wall portion 43b of the connecting portion 43'by welding or bolts or the like. Even with such a lower structure 4', the same action and effect as in the case of the above-mentioned lower structure 4 can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and modifications can be made based on the technical idea of the present invention. For example, in the above-described embodiment, an example is shown in which the upper wall portion of the connecting portion 43 has an inclined surface 53a, but depending on the thickness of each of the battery case portion 41 and the suspension frame portion 42 in the vertical direction. , The shape of the upper wall portion or the lower wall portion of the connecting portion 43 may be appropriately changed.

Further, in the above-described embodiment, a configuration example in which a plurality of partition walls are arranged inside the connecting portion 43 is shown, but it is also possible to apply the connecting portion 43 in which the partition wall portion is not provided. However, if at least one partition wall portion is provided inside the connecting portion 43, the rigidity of the connecting portion 43 can be improved, and vertical vibration and twisting of the lower structure can be more effectively suppressed. be. In particular, if the partition wall portion is provided at the center of the connecting portion 43 in the vehicle width direction or at the curved portion of the standing wall portion, the rigidity of the connecting portion 43 can be effectively increased.

1 ... Electric vehicle 2 ... Drive device 3 ... Front side member 4, 4'... Substructure 41 ... Battery case 41a ... Front end 42 ... Suspension frame 42a ... Suspension arm mounting point 42b ... Rear end 43, 43' ... Connecting part 43a ... Rear wall part 43b ... Front wall part 5 ... Upper member 5a ... Plate-shaped part 51 ... Rear part 51a ... Flange part 51b ... Front end part 52 ... Front part 52a ... Left and right side parts 52b ... Recessed part 52c ... Rear end part 53 ... Intermediate part 53a ... Inclined surface 6 ... Lower member 6a ... Plate-shaped part 61 ... Rear part 61a ... Flange part 61b ... Front end part 61c ... Reinforcing member 62 ... Front part 62a ... Left and right side parts 62b ... Recessed part 62c ... Rear end part 62d ... Front end 63 ... Intermediate 7 ... Internal parts 71a-71d ... Case frame 72a-72c ... Body connection parts 73a-73e ... Bulk partition parts B ... Battery unit P ... Power unit room

Claims (6)

In the lower structure of an electric vehicle, which is arranged in the lower part of the electric vehicle and extends in the front-rear direction and the vehicle width direction of the electric vehicle and has a battery case portion capable of accommodating a battery unit mounted on the electric vehicle inside.
A suspension frame portion that is arranged on the vehicle front side of the battery case portion and extends in the vehicle width direction, and a pair of left and right suspension arms that support the front suspension are attached to both sides in the vehicle width direction.
A connecting portion extending from the front end portion of the battery case portion toward each suspension arm mounting portion of the suspension frame portion and connecting the battery case portion and the suspension frame portion is provided.
The connecting portion has a portion located between the front end portion of the battery case portion and the rear end portion of the suspension frame portion extending in the vehicle width direction over the width of the suspension frame portion in the vehicle width direction. A lower structure of an electric vehicle, characterized in that the suspension frame portion extends in the vehicle vertical direction over the thickness of the vehicle in the vehicle vertical direction. The battery case portions are arranged on both sides in the vehicle width direction, and have left and right case frames extending in the vehicle front-rear direction.
The connecting portion has left and right outer wall portions extending from the front end portion of the battery case portion toward the suspension arm mounting portions of the suspension frame portion.
The lower structure of an electric vehicle according to claim 1, wherein the front end portion of the case frame and the rear end portion of the outer wall portion are connected to each other. The connecting portion extends from the upper part of the front end of the battery case portion to the upper part of the rear end of the suspension frame portion, and extends from the lower part of the front end of the battery case portion to the lower part of the rear end of the suspension frame portion. The lower wall portion, the front wall portion connecting the front end of the upper wall portion and the front end of the lower wall portion, and the rear wall connecting the rear end of the upper wall portion and the rear end of the lower wall portion. A closed cross section extending in the vehicle width direction is formed by the suspension.
The lower structure of an electric vehicle according to claim 1 or 2, wherein the upper wall portion of the connecting portion has an inclined surface inclined upward in the vehicle toward the rear of the vehicle. The connecting portion has a vertical wall portion extending in the vehicle width direction over the width of the suspension frame portion in the vehicle width direction, and the vertical wall portion has an intermediate portion in the vehicle width direction more than both end portions in a vehicle top view. The lower structure of an electric vehicle according to any one of claims 1 to 3, wherein the vehicle is projected forward. The lower structure of an electric vehicle according to claim 2, wherein the connecting portion is located inside the left and right outer wall portions in the vehicle width direction and has at least one partition wall portion extending in the vehicle front-rear direction. .. The connecting portion is located inside the left and right outer wall portions in the vehicle width direction, and extends in the vehicle width direction over a plurality of partition wall portions extending in the vehicle front-rear direction and the width of the suspension frame portion in the vehicle width direction. The lower structure of the electric vehicle according to claim 2, further comprising a standing wall portion and having the plurality of partition wall portions provided at intervals along the standing wall portion.

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