JP7275841B2 - Rear structure of electric vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear structure of an electric vehicle including a rear floor and parts to be protected against rear collisions disposed under the rear floor.

For example, among vehicle parts such as fuel tanks, high-voltage parts (charging device (battery), power supply device, etc.) and high-voltage related parts (generating engine, etc.), those installed under the rear floor may (hereinafter abbreviated as "rear collision"), there is a risk of being impacted by a collision object entering from the rear end of the vehicle body, so it is required to provide a protector behind it as a part to be protected against rear collision.

As a protector, for example, as exemplified in Patent Document 1, a configuration is known in which a protector covering at least the lower side and the rear side of a fuel tank as a part to be protected is provided with a tank frame member as a protection frame.

However, the protector using a protection plate is more effective from the viewpoint of weight reduction than using a protection frame. Here, since the protection plate tends to be inferior in strength to the protection frame, the protection plate is formed in a shape that curves from the lower part to the upper rear part of the part to be protected when viewed from the side. It is considered effective to shed the impact load by sliding downward along the rear surface of the protection plate instead of directly receiving the impact object that has collided from the rear of the protection plate.

However, since it is still necessary to increase the resistance to the rear impact load, it is possible to form a closed cross-section inside the protection plate. There is a concern that the downward sliding of the colliding object is sometimes hindered.

JP-A-2005-112271

SUMMARY OF THE INVENTION The present invention has been made in view of such problems. It is an object of the present invention to provide a rear structure of an electric vehicle capable of improving the strength of a protection plate by forming a closed cross section while suppressing the deformation.

The present invention provides a rear structure for an electric vehicle including a rear floor and a part to be protected against a rear collision disposed under the rear floor. The protection plate is formed in a curved shape or an inclined shape extending from the rear lower part to the rear upper part of the part to be protected, and the protection plate includes a front side plate member and a rear side plate member. Both of the front and rear plate members are formed in an uneven shape when viewed from the side, and due to the uneven shape of the front and rear plate members, a closed cross section is formed between the front and rear plate members when viewed from the side. is formed in an uneven shape that is smoother than the front plate member.

According to the above configuration, when the colliding object that has collided with the rear surface of the protection plate at the time of a rear-end collision is parried downward along the rear surface of the colliding object, it is possible to prevent the colliding object from being hindered from sliding while forming a closed cross-section. Formation can increase the strength of the protective plate.

As an aspect of the present invention, the outer ends of the front and rear plate members in the vehicle width direction are both joined to a protective frame, and the vehicle width direction central portion of the rear plate member projects rearward in a plan view. The center of the closed cross-section in the vehicle width direction is expanded by curving as shown in FIG.

According to the above configuration, the front and rear plate members are joined to the protective frame, and the rear plate member is curved as described above to expand the center of the closed cross section in the vehicle width direction. Without narrowing the distance between the front side plate member and the front plate member, it is possible to improve the yield strength when a load is applied to the protection plate, including the central portion in the vehicle width direction, where the yield strength of the protection plate installed between the protection frames tends to be low. .

As a mode of the present invention, the front side plate member is formed so that the unevenness change in the uneven shape in a side view of the central portion with respect to the outer portion in the vehicle width direction is larger than that of the rear side plate member, and the closed cross section The center of the vehicle width direction is expanded.

According to the above configuration, when an object that has collided with the rear surface of the protection plate at the time of a rear-end collision is flowed downward along the rear surface, the object is caught on the uneven stepped portion (ridge line) of the rear plate member. While suppressing the hindrance of the sliding by such as, by forming a large uneven change in the uneven shape of the central portion of the front side plate member in the vehicle width direction, the protective plate installed between the protective frames It is possible to increase the yield strength of the center in the vehicle width direction, which tends to be low.

As an aspect of the present invention, the front plate member forming the closed cross section together with the rear plate member is formed with a ridge line projecting toward the inside of the closed cross section.

According to the above configuration, in order to ensure the strength of the protection plate, increasing the ridgeline of the front plate member is prioritized over forming the closed cross section to increase the cross-sectional rigidity of the closed cross section. It is possible to increase the strength of the protective plate while earning a space for arranging the .

According to the present invention, when the collision object that has collided with the rear surface of the protection plate at the time of rear-end collision is parried downward along the rear surface of the protection plate, it is possible to suppress the hindrance of the sliding of the collision object, while the closed cross-section is formed. Formation can increase the strength of the protective plate.

The perspective view which looked at the rear part structure of the electric vehicle of this embodiment from the bottom face side. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and showing a main part; FIG. 2 is a cross-sectional view taken along the line BB in FIG. 1 and showing the main part; The left side view which shows the principal part of the rear part structure of the electric vehicle of this embodiment. The perspective view which looked the protector from the front diagonally upper left. Front view of the protector. Rear view of the protector. FIG. 8 is a cross-sectional view showing the main part of the rear structure of the electric vehicle according to the present embodiment, taken along line CC and line DD in FIG. 7; FIG. 8 is a cross-sectional view showing the main part of the rear structure of the electric vehicle according to the present embodiment, taken along line EE and line FF in FIG. 7; FIG. 8 is a cross-sectional view showing a main part corresponding to lines GG and HH in FIG. 7;

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a perspective view of the rear structure of an electric vehicle according to the present embodiment as viewed from the bottom side, and FIG. 2 is a cross-sectional view taken along line AA in FIG. Fig. 4 is a vertical cross-sectional view showing a main part along a position corresponding to the protection frame in Fig. 3; FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1, which is a longitudinal cross-sectional view showing the main part along a position corresponding to the center in the vehicle width direction. Fig. 5 is a perspective view of the protector as seen obliquely from the front left and above; Fig. 6 is a front view of the protector; Fig. 7 is a rear view of the protector; 10(a) is a cross-sectional view showing a main portion corresponding to line C--C in FIG. 7 of the rear structure of the electric vehicle according to the present embodiment, which corresponds to line C'--C' in FIG. 10(a); FIG. 8(b) is a cross-sectional view showing the main part of the rear structure of the electric vehicle according to the present embodiment, taken along line DD in FIG. FIG. 9A is a cross-sectional view showing the main part corresponding to line -D', and FIG. 9A is a cross-sectional view showing the main part corresponding to line EE in FIG. FIG. 10(a) is a cross-sectional view showing a main part corresponding to line E'-E', and FIG. 9(b) is a main part corresponding to line FF in FIG. 7 of the rear structure of the electric vehicle according to the present embodiment. FIG. 10(a) is a cross-sectional view showing a main part corresponding to the line F'-F' of FIG. 10(a), and FIG. FIG. 10(b) is a cross-sectional view showing a main part corresponding to line HH in FIG.

In the drawings, arrow F indicates the front of the vehicle, arrow R indicates the right of the vehicle, arrow L indicates the left of the vehicle, and arrow U indicates the upper side of the vehicle.

In the electric vehicle of the present embodiment, when the electric capacity of the battery drops below a predetermined value during long-distance travel, etc., the internal combustion engine for power generation drives the generator, and the generated power is supplied to the battery for charging. It is an electric vehicle called a configured range extender.

As shown in FIG. 2, in the lower part of the vehicle, there are a front floor panel 1 that forms the floor of the passenger compartment, and a kick-up portion 2 that rises upward from the rear end of the front floor panel 1. , and a rear floor panel 3 extending rearward from the upper portion of the kick-up portion 2 .

As shown in FIGS. 1 and 2 , rear side frames 4 extending in the longitudinal direction of the vehicle are arranged along both sides of the rear floor panel 3 behind the kick-up portion 2 .

The rear side frame 4 has a rectangular cross-section perpendicular to the vehicle front-rear direction, and has a closed cross-section 4s extending in the vehicle front-rear direction.
A rear bumper 5 having a closed cross-sectional shape extending in the vehicle width direction is disposed on the rear side of the vehicle body of the rear side frame 4. The rear bumper 5 is attached to the pair of left and right rear side frames 4 from its rear end to the rear of the vehicle. are connected via a crash can 6 or the like extending to the

As shown in FIG. 2, the pair of left and right rear side frames 4 includes a front horizontal portion 4F extending horizontally from the kick-up portion 2 toward the rear of the vehicle and an inclined portion extending obliquely upward and rearward from the rear end of the front horizontal portion 4F. and a rear horizontal portion 4R extending horizontally toward the rear of the vehicle from the rear end of the inclined portion 4M.

Between the pair of left and right rear side frames 4, a front cross member 7f is joined and fixed to the rear surface of the kick-up portion 2 and extends in the vehicle width direction. An intermediate cross member 7m that is joined and fixed to sandwich the rear floor panel 3 and extends in the vehicle width direction, and a rear side that is joined and fixed from the lower surface side of the rear floor panel 3 at an intermediate position of the rear horizontal portion 4R and extends in the vehicle width direction. and a cross member 7r.
The intermediate cross member 7m is composed of an upper intermediate cross member 7mu joined and fixed to the upper surface of the rear floor panel 3 and a lower intermediate cross member 7md joined and fixed to the lower surface of the rear floor panel 3.

Here, the portion between the front side cross member 7f and the intermediate cross member 7m of the rear floor panel 3 is set at the rear floor panel front portion 3f, and the portion between the intermediate cross member 7m and the rear side cross member 7r is set at the rear floor panel. The intermediate portion 3m is set, and the rear side portion of the rear cross member 7r is set to the rear floor panel rear portion 3r.

As shown in FIGS. 1 and 2, below the front floor panel 1 and the front portion 3f of the rear floor panel, electric power for the motor (not shown) is stored as a power source for driving the wheels. A battery device (so-called battery pack) 10 is arranged. As shown in FIG. 2, the battery device 10 comprises a battery unit 11 with a plurality of battery bodies 11a.

A plurality of battery units 11 are stored in a one-tiered structure at a position corresponding to the lower part of the front floor panel 1, and a two-tiered structure at a position corresponding to the lower front part 3f of the rear floor panel. Stored.

The above-described battery device 10 also includes a battery tray 12 that supports a plurality of battery units 11 from below, and a battery that is attached to the upper surface of an external flange of the battery tray 12 and incorporates each of the above-described battery units 11 therein. A case 13 is provided from the front floor panel 1 to the front part 3f of the rear floor panel.

The battery device 10 described above is provided with a plurality of battery frames (14, 15, etc.) that form the framework of the battery device 10 and support and reinforce the battery tray 12. As shown in FIG.

Among them, reference numeral 14 in FIG. 2 denotes a rear battery frame that extends in the vehicle width direction at the rear end of the battery tray 12 and supports the battery tray 12 from the rear, and reference numeral 15 denotes a cross-sectional hat that opens downward. It is an intermediate battery frame that is formed in a shape, extends in the vehicle width direction at an intermediate position in the vehicle front-rear direction of the battery tray 12, and is joined to the upper surface portion of the battery tray 12 so as to form a closed cross section 15s. .

As shown in FIG. 1, a rear suspension device 16 is attached to the inclined portion 4M of the rear side frame 4 described above.
The rear suspension device 16 has a trailing arm 17 extending in the longitudinal direction of the vehicle. A front end of the trailing arm 17 is connected to the inclined portion 4M of the rear side frame 4 so as to be vertically swingable, and a wheel support 18 for supporting a rear wheel (not shown) is attached to the rear end. It is

The rear suspension device 16 has a torsion beam 19 extending in the vehicle width direction so as to connect the left and right trailing arms 17. As shown in FIGS. It extends in the vehicle width direction and has an inverted U-shaped cross-sectional shape that is open at the bottom in the vehicle width direction. Further, as shown in FIG. 1 , the rear suspension device 16 is provided with a spring seat 161 at a corner portion between the torsion beam 19 and the trailing arm 17 .

Further, the rear suspension device 16 has a coil spring attached to the spring seat 161, a tube type damper attached to the rear end of the spring seat 161, etc., but these are not shown.
2 and 3 show only the torsion beam 19 provided in the rear suspension device 16, and illustration of the rear suspension device 16 is omitted except for FIGS.

As shown in FIGS. 1 to 3, a fuel tank 50 is arranged below the intermediate portion 3m of the rear floor panel. In other words, the fuel tank 50 is spaced rearward from the torsion beam 19 in a side view in the space between the left and right trailing arms 17 of the rear suspension device 16 .

The fuel tank 50 stores fuel to be supplied to the internal combustion engine for power generation, and constitutes a part of the range extender device together with the generator using high voltage. Therefore, the fuel tank 50 is a part to be protected against a rear collision, and is provided with a protector 20 (tank protector 20) at the rear and downward.

Incidentally, although not shown in the drawings, in internal combustion engine vehicles such as gasoline and diesel vehicles equipped with an internal combustion engine for driving, the battery device 10 is not mounted below the front portion 3f of the rear floor panel as well as below the front floor panel 1. Therefore, the fuel tank 50 can be mounted in front of the rear suspension device 16, that is, below the front portion 3f of the rear floor panel (not shown). In the internal combustion engine vehicle, accordingly, the rear side horizontal portion 4R (see FIG. 2) of the rear side frame 4 corresponding to the rear of the front portion 3f of the rear floor panel is set as a crushable zone CZ (crash stroke). In many cases, the entire rear horizontal portion 4R collapses together with the crash can 6 at the time of a rear collision, thereby absorbing the rear collision energy.

On the other hand, in an electric vehicle called a range extender, as shown in FIG. In many cases, a fuel tank 50 for power generation is mounted 3 m below the intermediate portion of the rear floor panel behind the mounting location of the fuel tank (not shown) in the internal combustion engine vehicle.

In this case, as shown in FIGS. 2 and 4, the portion of the rear horizontal portion 4R of the rear side frame 4 corresponding to the rear floor panel rear portion 3r behind the rear floor panel intermediate portion 3m is set as the crushable zone CZ. there is

As described above, in the electric vehicle of the present embodiment, in which the crash stroke for absorbing the rear impact energy of the rear side frames 4 is shorter than that of the internal combustion engine vehicle, the rear side frames 4 are positioned forward of the rear floor panel rear portion 3r. A corresponding portion is set as a protection zone PZ, and a protector 20 is provided from the rear to the bottom of the fuel tank 50 in order to protect the fuel tank 50 arranged in the protection zone PZ from rear collision. .

As shown in FIGS. 1 to 4, the protector 20 is bridged between a pair of protective frames 21 disposed on both sides of the fuel tank 50 and the left and right protective frames 21. It has a protective plate 31 and is formed in a substantially symmetrical shape. The protector 20 has a clearance (distance) with respect to the fuel tank 50 and is provided from the front lower part to the rear upper part (see FIG. 3).

As shown in FIGS. 2 and 4, the protection frame 21 is arranged below and behind the fuel tank 50 as viewed from the side. More specifically, the protective frame 21 has a lower portion that extends gently upward, that is, generally horizontally, from the front and lower portions of the fuel tank 50 toward the rear so as to bypass the torsion beam 19 that extends in the vehicle width direction in front of the fuel tank 50 . , and a rear portion that rises from the rear side of the lower portion and extends from the lower rear portion to the upper rear portion of the fuel tank 50 .

The protective frame 21 is curved upward over the entire length in the extending direction (longitudinal direction) of the protective frame 21 (that is, from the front lower end to the rear upper end) when viewed from the side, and the curvature increases toward the rear. A portion 80 is formed (see FIG. 4). In other words, the protection frame 21 is formed with the curved portion 80 in which the inclination of the tangential line at each portion from the front lower end to the rear upper end in a side view becomes gradually steeper toward the rear.

As shown in FIGS. 4 to 9(a) and (b), the protective frame 21 includes an inner peripheral wall 21a located on the curved inner surface (in other words, the upper surface, the front surface, or the radially inner side) and a curved outer surface (in other words, the lower surface, the rear surface). or radially outward), an outer wall 21c connecting the vehicle width direction outer ends of the inner peripheral wall 21a and the outer peripheral wall 21b, and the vehicle width direction inner ends of the inner peripheral wall 21a and the outer peripheral wall 21b. Together with the connecting inner wall 21d, a closed cross section 21s is formed inside, and a hollow rectangular cross section having a rectangular cross section perpendicular to the extending direction is formed.

As shown in FIGS. 1 and 2, the rear upper end of the protective frame 21 is attached to the rear cross member 7r extending in the width direction of the vehicle as a vehicle body component above the rear upper end by way of the rear upper end bracket 24 from the lower surface side of the rear cross member 7r. It is vertically fastened and fixed, and its front lower end is substantially horizontally fastened and fixed to the rear battery frame 14 provided in front thereof via a front lower end bracket 25 .

As shown in FIGS. 1, 3, 6, 8(a)(b), and 9(a)(b), the protection plate 31 mainly covers the rear lower end of the fuel tank 50 from the rear upper end. It is provided between a pair of left and right protective frames 21, and is formed in a curved shape that curves upward from the front lower end to the rear upper end as viewed from the side.

As shown in FIGS. 3, 10(a) and 10(b), the protection plate 31 includes a front plate member 32 and a rear plate member 33. These front and rear plate members 32 and 33 allow the front and rear plate members 32 and 33 to extend the front and rear plate members 32 and 33 when viewed from the side. Closed cross-section portions 34 and 35 are formed between which closed cross-sections 34s and 35s are formed.

Two closed cross-section portions 34 and 35 are provided, a front lower closed cross-section portion 34 located on the front lower side and a rear upper closed cross-section portion 35 located on the rear upper side of the protection plate 31 in side view. there is Closed cross-sections 34s and 35s of approximately the same size are formed inside the front lower closed cross-section portion 34 and the rear upper closed cross-section portion 35, which are separated from each other in a side view.

As shown in FIGS. 10(a) and 10(b), the front plate member 32 includes a front lower flange 32a extending forward and downward from a portion corresponding to the front lower end of the front lower closed cross-section portion 34, and a front lower closed cross-section portion 34. An intermediate flange 32b provided at a portion corresponding to between the cross-sectional portion 34 and the rear upper closed cross-section portion 35, and a rear upper flange 32c extending rearward and upward from a portion corresponding to the rear upper end of the rear upper closed cross-section portion 35 are formed. It is Similarly, the rear plate member 33 includes a front lower flange 33a extending forward and downward from a portion corresponding to the front lower end of the front lower closed cross-section portion 34, a front lower closed cross-section portion 34, and a rear upper closed cross-section portion. 35, and a rear upper flange 33c extending rearward and upward from a portion corresponding to the rear upper end of the rear upper closed cross-section portion 35 are formed.

The front plate member 32 and the rear plate member 33 are joined by spot welding or the like at the front lower flanges 32a, 33a, the intermediate flanges 32b, 33b, and the rear upper flanges 32c, 33c. , 33a, intermediate joints 32b, 33b, and rear upper joints 32c, 33c.

The protection plate 31 is configured such that portions of the front plate member 32 and the rear plate member 33 corresponding to the front lower closed cross-section portion 34 and the rear upper closed cross-section portion 35 are formed in an uneven shape when viewed from the side. Further, the rear plate member 33 is formed to have an uneven shape that is smoother than the front plate member 32 .

Specifically, as shown in FIGS. 10A and 10B, the front walls of the front lower closed cross-section portion 34 and the rear upper closed cross-section portion 35 are formed by part of the front plate member 32. .
The front plate member 32 has a front lower front wall portion 340 corresponding to the front wall of the front lower closed cross-section portion 34 and a rear upper front wall portion 350 corresponding to the front wall of the rear upper closed cross-section portion 35 . The front lower front wall portion 340 is positioned above the front lower flange 32a and the intermediate flange 32b, and the rear upper front wall portion 350 is positioned between the intermediate flange 32b and the rear upper flange 32c. It is arranged so as to be positioned in the front direction.

The front lower front wall portion 340 has a front lower rear bulging portion 341 bulging toward the rear plate member 33 (in the rear lower direction) at the intermediate portion thereof in a side view. It is formed to have a protruding portion 341, a first front lower front wall portion 342 located under the protruding portion 341, and a second front lower front wall portion 343 located above it.

Similarly, the rear upper front wall portion 350 is formed with a rear upper rear bulging portion 351 bulging toward the rear plate member 33 (rearward) at its intermediate portion in a side view. It is formed to have a bulging portion 351, a first rear upper front wall portion 352 located on the front and lower side of the bulging portion 351, and a second rear upper front wall portion 353 located on the upper side thereof.

As shown in FIG. 9( a ), the front plate member 32 extends substantially linearly in parallel with the vehicle width direction over the entire width direction of the first rear upper front wall portion 352 in a plan view. ing.
Similarly, although not shown, the front plate member 32 also includes the first front lower front wall portion 342, the second front lower front wall portion 343, and the second rear upper front wall portion 353 in a plan view, and the entire vehicle width direction is extending substantially linearly in parallel with the vehicle width direction.

The front side plate member 32 bulges forward and upward from the peripheral portions in a side view. By forming the substantially linear shape, for example, compared to a shape (not shown) in which the center in the vehicle width direction bulges forward from the outside in a plan view, the clearance for the fuel tank 50 is ensured, and the shape is, for example, planar. As seen, the size of the closed cross sections 34s and 35s is ensured compared to a shape (not shown) in which the center in the vehicle width direction bulges rearward from the outside.

The front plate member 32 has an intermediate flange 32b as shown in FIG. 9(b), a rear upper rear bulging portion 351 as shown in FIG. It is curved so as to protrude rearward from the outside in the vehicle width direction.
A virtual line LL in FIGS. 8B and 9B indicates a virtual straight line extending parallel to the vehicle width direction.

Similarly, although not shown, the front plate member 32 has the front lower flange 32a, the rear upper flange 32c, and the front and lower rear bulging portions 341, and the central portions thereof in the vehicle width direction are positioned further rearward than the outer sides in the vehicle width direction in plan view. It is curved to form a protruding shape.

In this manner, the front plate member 32 is formed by curving the center portions in the vehicle width direction of the portions 32a, 32b, 32c, 341, and 351 rearward in a plan view, so that the center portions in the vehicle width direction are outwardly curved. The clearance with the fuel tank 50 is ensured as compared with the shape that bulges forward.

Further, as shown in FIG. 10(a), the front plate member 32 is formed to have an uneven shape when viewed from the side as described above, thereby forming a plurality of ridge lines R extending in the vehicle width direction. 32 itself has increased resistance.

As shown in FIG. 10(a), among these ridgelines R formed on the front plate member 32, there are ridgelines R1 projecting toward the inside of the closed cross-sections 34s and 35s, that is, front and rear bulging portions 341. and a ridge line R1 formed on each of the rear upper rear bulging portion 351 .

Further, as shown in FIGS. 10A and 10B, the rear plate member 33 includes a front lower rear wall 380 corresponding to the rear wall of the front lower closed cross-section portion 34 and a rear wall of the rear upper closed cross-section portion 35. The front lower rear wall 380 is arranged so as to be positioned in the rear lower direction with respect to the front lower flange 33a and the intermediate flange 33b, and the rear upper rear wall 390 corresponds to the rear upper rear wall 390. 390 is positioned rearwardly with respect to the intermediate flange 33b and the rear upper flange 33c.

The front-lower-rear wall 380 has a front-lower front bulging portion 381 bulging toward the front-side plate member 32 (upward) at its intermediate portion in a side view. Similarly, the rear upper rear wall 390 is formed with a rear upper front bulging portion 391 that bulges toward the front plate member 32 (forward direction) at its intermediate portion in a side view.

A plurality of ridgelines R are formed on the rear plate member 33 as well by forming the uneven shape in a side view in this manner, and the plurality of ridgelines R increase the strength of the rear plate member 33 itself (Fig. 10(a)).

However, as described above, the rear plate member 33 is formed in a smoother concave-convex shape than the front plate member 32 .

Specifically, the front lower front bulging portion 381 is close to the front lower rear bulging portion 341 in the closed cross section 34s of the front lower closed cross section 34 in side view, but faces each other with a gap therebetween. , and the amount of swelling is formed to be smaller than that of the front-to-bottom-rear swelling portion 341 .

Similarly, the rear upper front bulging portion 391 is close to the rear upper rear bulging portion 351 in the closed cross section 35s of the rear upper closed cross section 35 in a side view, but faces each other with a gap therebetween. The bulging amount is formed to be smaller than that of the bulging portion 351 .

As a result, a ridgeline R is formed also at the intermediate positions of the rear walls of the closed cross-section portions 34 and 35 to increase the cross-sectional rigidity, and at the time of a rear-end collision, an object that collides with the rear surface of the protection plate 31 (rear side plate member 33) can be prevented. It is possible to prevent obstruction of the sliding of the colliding object when parrying it downward along the rear surface.

Further, the rear plate member 33 has a front lower flange 33a, an intermediate flange 33b, and a rear upper flange 33c which bulge forward and upward with respect to the periphery when viewed from the side. The amount of swelling is kept to a small amount compared to the lower rear swelling portion 341 and the rear upper rear swelling portion 351 .

As a result, the protection plate 31 does not form the closed cross-sectional portions 34 and 35, so that the joint portions (the front lower joint portions 32a and 33a, the intermediate joint portions 32b and 33b, and the rear upper joint portion 32c) which may be weakened , 33c) are also formed with a ridge line R to reinforce the joint portion, and at the time of a rear-end collision, an object that collides with the rear surface of the protection plate 31 (rear side plate member 33) is deflected downward along the rear surface. In this case, it is possible to suppress the hindrance of the sliding of the collision object.

As shown in FIGS. 7, 8(a), 8(b), and 9(a)(b), the front plate member 32 and the rear plate member 33 extend outward in the vehicle width direction from their respective outer ends in the vehicle width direction. It forms outer flanges 41, 42 which extend into.

As shown in FIG. 7 , the outer flange 42 of the rear plate member 33 has a rear upper end outer flange 43 extending outward in the vehicle width direction from the rear upper end of the rear plate member 33 and a rear upper end outer flange 43 . and a main outer flange 44 extending outward in the vehicle width direction from a position spaced apart in the forward and downward direction.

The rear upper outer flange 43 extends outward in the vehicle width direction with a length that allows the end extending outward in the vehicle width direction to abut against the inner wall 21 d of the protection frame 21 .

The main outer flange 44 is integrally formed with a main outer flange rear upper portion 441 , a main outer flange intermediate portion 442 , and a main outer flange front lower portion 443 , the main outer flange intermediate portion 442 extending from the front plate member 32 . is formed to extend at substantially the same position as the outer flange 41 in the side view. However, the outer flange 41 of the front plate member 32 is formed to extend further outward in the vehicle width direction than the intermediate portion 442 of the main outer flange (Figs. 7, 8(b), 9(a) and (b). )reference).

As a result, the outer flange 41 of the front plate member 32 and the main outer flange intermediate portion 442 of the rear plate member 33 are attached to the outer peripheral wall 21b of the protective frame 21 by the main outer flange intermediate portion 442. In the state where it is arranged so as to be covered from the rear, the front end portion 41a of the outer flange 41 of the front plate member 32 on the outer side in the vehicle width direction is positioned further in the vehicle width direction than the outer end of the main outer flange intermediate portion 442 in the vehicle width direction. It will be in a state of being extended to the outside.

7, in the main outer flange 44 of the rear plate member 33, the main outer flange rear upper portion 441 adjacent to the main outer flange intermediate portion 442 on the rear upper side, and the main outer flange rear upper portion 441 adjacent on the front lower side to the main outer flange intermediate portion 442 Both of the flange front lower portions 443 are formed to extend outward in the vehicle width direction from the main outer flange intermediate portion 442 .

In the protection plate 31 described above, the front and rear plate members 32 and 33 are joined to each other and integrated, and the respective plate members 32 and 33 are joined to the left and right protection frames 21 .

Specifically, the front plate member 32 and the rear plate member 33 are joined by spot welding at the front lower flanges 32a and 33a, the intermediate flanges 32b and 33b, and the rear upper flanges 32c and 33c, respectively, as described above ( 10 (a) and (b)), and furthermore, the outer flange 41 of the front plate member 32 and the main outer flange intermediate portion 442 of the rear plate member 33 are joined by spot welding (see FIG. 7 (see x mark) are integrated so as to overlap each other.

Further, between the left and right protective frames 21, a protective plate 31 is arranged so as to bridge between them, in which the front and rear plate members 32 and 33 are integrated with each other. At this time, as shown in FIGS. 7 and 8(a), the left and right rear upper end outer flanges 43 of the rear plate member 33 are attached to the protection frame 21 whose extending ends to the outside in the vehicle width direction correspond to the left and right sides, respectively. Since they abut against the inner wall 21d, they are joined together by arc welding at this abutting portion.

Further, as shown in FIG. 7, on both left and right sides, the rear plate member 33 includes a main outer flange rear upper portion 441, a main outer flange front lower portion 443, and an outer peripheral wall 21b of the protective frame 21 with the rear surface abutting thereon. are joined by arc welding (see M1 and M2 in FIG. 7).

In addition, on the left and right sides of the front plate member 32, a tip portion 41a extending outward in the vehicle width direction from the main outer flange intermediate portion 442 of the outer flange 41, and a protective frame whose rear surface abuts on the tip portion 41a. 21 are joined by arc welding (see M3 in FIGS. 7, 8(b), 9(a) and 9(b)).

That is, the protective plate 31 is configured such that the front and rear plate members 32 and 33 are spot-welded together, and the rear upper end outer flange 43, the main outer flange rear upper portion 441, and the main outer flange front lower portion 443 of the rear plate member 33 are attached. are directly joined to the protective frame 21 , and the tip portion 41 a of the outer flange 41 of the front plate member 32 is directly joined to the protective frame 21 .

As shown in FIGS. 1 to 4, the rear structure of the electric vehicle of the present embodiment described above includes a rear floor panel 3 (rear floor) and a rear floor panel 3 disposed below the rear floor panel 3 to protect against rear collision. As shown in FIG. 3, a protection plate 31 arranged from the rear lower part to the rear part of the fuel tank 50 in side view as shown in FIG. The protection plate 31 is formed in a curved shape extending from the rear lower part of the fuel tank 50 to the rear upper part, and the protection plate 31 includes a front side plate member 32 and a rear side plate member 33, and is shown in FIGS. 3 and 10 ( As shown in a) and (b), the front and rear plate members 32 and 33 are both formed in an uneven shape when viewed from the side. Closed sections 34 s and 35 s are formed between them in a side view, and the rear plate member 33 is formed to have a smoother uneven shape than the front plate member 32 .

According to the above configuration, when the colliding object that has collided with the rear surface of the protection plate 31 at the time of a rear collision is parried downward along the rear surface, the cross section is closed while suppressing the hindrance of the sliding of the colliding object. The strength of the protective plate 31 can be improved by forming 34s and 35s.

As shown in FIGS. 7, 8(a), 8(b), and 9(a), (b), as a mode of the present invention, the outer ends of the front and rear plate members 32, 33 in the vehicle width direction, that is, the front The outer flange 41 of the plate member 32, the rear upper end outer flange 43 of the rear plate member 33, the main outer flange rear upper portion 441 and the main outer flange front lower portion 443 are all joined to the protective frame 21, as shown in FIGS. As shown in (a), in plan view, the rear plate member 33 is curved so that its center portion in the vehicle width direction protrudes rearward, thereby expanding the vehicle width direction center of the closed cross-sections 34s and 35s. It is.

According to the above configuration, by joining the front and rear plate members 32 and 33 to the protective frame 21 , it is possible to improve the resistance when a load acts on the protective plate 31 .

Further, by curving the rear plate member 33 as described above to expand the central portions of the closed cross-sections 34s and 35s in the vehicle width direction, the protection plate 31 can be formed without narrowing the distance between the fuel tank 50 and the front plate member 32. It is possible to increase the cross-sectional rigidity of the central portion in the vehicle width direction.

More specifically, in this example, the front plate member 32 is formed substantially linearly in parallel with the vehicle width direction over the entire vehicle width direction (see FIG. 9A). That is, the protective plate 31 is formed such that the rear plate member 33 protrudes rearward at the center in the vehicle width direction and has a more curved shape in plan view than the front plate member 32 . It is.

Therefore, the front side plate member 32 can be arranged without narrowing the distance from the fuel tank 50, and by curving the rear side plate member 33 rearward, the central portions of the closed sections 34s and 35s in the vehicle width direction can be expanded. As a result, in the protection plate 31 installed between the protection frames 21, the yield strength at the center in the vehicle width direction, which tends to be low, can be increased.

As shown in FIGS. 3, 10(a) and 10(b), as a mode of the present invention, the front side plate member 32 is configured such that the center portion of the front side plate member 32 is uneven in a side view with respect to the outer side portion of the rear side plate member 33 in the vehicle width direction. It is formed so that the unevenness of the shape is increased, and the center of the closed cross sections 34s and 35s in the vehicle width direction is expanded.

According to the above configuration, in the protection plate 31 installed between the protection frames 21, the center of the closed sections 34s and 35s in the vehicle width direction is expanded in order to increase the yield strength of the vehicle width direction center where the yield strength tends to be low. In this regard, the rear plate member 33 is formed so that the front plate member 32 has a greater unevenness change in the side view of the central portion than the rear plate member 33 with respect to the outer portion in the vehicle width direction. It is possible to reduce as much as possible the uneven stepped portion (ridge line R) formed in the side view.

As a result, when a collision object collided with the rear surface of the protection plate 31, that is, the rear surface of the rear plate member 33 at the time of a rear collision, is flowed downward along the rear surface, the uneven step portion of the rear plate member 33 is formed. While suppressing obstruction of sliding due to colliding objects being caught on (ridge line R), the yield strength of the center of the vehicle width direction where the yield strength of the protection plate 31 constructed between the protection frames 21 tends to be low is reduced. can be enhanced.

As shown in FIG. 10(a), as a mode of the present invention, a front plate member 32 forming closed cross sections 34s and 35s together with a rear plate member 33 has ridge lines protruding toward the inside of the closed cross sections 34s and 35s. R1 was formed.

According to the above configuration, in order to ensure the strength of the protection plate 31, for example, the front plate member 32 forming the closed cross sections 34s and 35s together with the rear plate member 33 bulges forward (to the side where the fuel tank 50 is provided). Rather than forming the closed cross-sections 34s and 35s larger by forming the closed cross-sections 34s and 35s, the front walls of the closed cross-sections 34s and 35s, that is, the front lower front wall portions 340 of the front plate member 32 are formed with the front lower rear bulging portions 341, By forming the rear upper rear swelling portion 351 in the rear upper front wall portion 350, priority is given to increasing the ridgeline R1.

As a result, the strength of the protection plate 31 can be increased by increasing the cross-sectional rigidity of the closed cross-sections 34s and 35s while securing a space for arranging the fuel tank 50 .

The present invention is not limited to only the configurations of the examples described above, but can be formed in various embodiments.
Although the protection plate 31 of the present embodiment is formed in a curved shape extending from the rear lower part to the rear upper part of the fuel tank 50 in a side view, it is not limited to this and is omitted from the drawing, but is directed from the rear lower part to the rear upper part of the fuel tank 50 . A configuration formed in a linearly inclined shape may be adopted.

In this example, joints using arc welding as a welding means may be joined by laser welding instead of arc welding.

3 … Rear floor panel (rear floor)
21 Protective frame 31 Protective plate 32 Front plate member 33 Rear plate members 34s, 35s Closed section 41 Outer flange (outer end of the front plate member in the vehicle width direction)
43 ... rear upper end outer flange (outer end of the rear plate member in the vehicle width direction)
50...Fuel tank (Parts to be protected)
441 ... Rear upper part of the main outer flange (outer end of the rear plate member in the vehicle width direction)
443 ... Lower front portion of main outer flange (outer end of rear plate member in vehicle width direction)
R1...Ridge line (Ridge line protruding toward the inside of the closed cross section of the front plate member)

Claims (4)

A rear structure for an electric vehicle comprising a rear floor and a part to be protected against a rear collision disposed under the rear floor,
Equipped with a protection plate routed from the rear lower part of the part to be protected in a side view to the rear,
The protective plate is formed in a curved shape or an inclined shape extending from the rear lower part to the rear upper part of the part to be protected,
The protection plate includes a front plate member and a rear plate member,
Both the front and rear plate members are formed in an uneven shape when viewed from the side,
A rear portion of an electric vehicle in which a closed cross section is formed between the front and rear plate members in a side view due to the uneven shapes of the front and rear plate members, and the rear plate member is formed in a smoother uneven shape than the front plate member. structure. Outer ends of the front and rear plate members in the vehicle width direction are joined together to a protective frame,
2. The rear portion of the electric vehicle according to claim 1, wherein the rear plate member is curved so that the vehicle width direction central portion of the rear plate member protrudes rearward in a plan view, thereby expanding the vehicle width direction center of the closed cross section. structure. The front plate member is formed so that the uneven shape in a side view of the central portion with respect to the outer portion in the vehicle width direction has a larger uneven change than the rear plate member, and the center of the closed cross section in the vehicle width direction is formed. The rear structure of an electric vehicle according to claim 2, which is expanded. The electric vehicle according to any one of claims 1 to 3, wherein the front plate member that forms the closed cross section together with the rear plate member has a ridge line that protrudes toward the inside of the closed cross section. rear structure.

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