Electric vehicle rear part structure

Abstract

To improve rigidness of a floor part on which a spare tire is installed, and improve fitting rigidity of the spare tire.SOLUTION: An electric vehicle rear part structure comprises a tire storage part 12 which is provided on a floor part positioned on a rear side of a battery pack, and can accommodate a spare tire. The tire storage part 12 has a concave shape recessed downward, and has a bottom, and outer side wall parts 18, 19 which extend upward from vehicle width both side ends of the bottom. A central bead part 16 extending in a width direction is provided on the bottom, reinforcement members 40, 50 to be joined to the bottom and the outer side wall part are joined in an outside part of the central bead part 16, and the outside part of the central bead part 16 is located between front ends and rear ends of the reinforcement members 40, 50.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a rear structure of an electric vehicle. [Background technology]

[0002] A battery pack is disposed below the floor of an electric vehicle. The battery pack is a generally rectangular parallelepiped device that has a predetermined dimension in the vehicle width direction and extends in the vehicle longitudinal direction, and supplies power to, for example, a drive motor disposed in the front of the vehicle. The rear of the electric vehicle must be rigid and strong enough to withstand impact loads such as those caused by a rear-end collision. In an electric vehicle having a battery pack, the rear of the floor must be rigid and strong enough to protect the battery pack when subjected to an impact load such as a rear-end collision.

[0003] Also, as disclosed in Patent Document 1, there is known a vehicle that is provided with a tire storage section in the rear of the vehicle that can store a spare tire. For example, the tire storage section disclosed in Patent Document 1 is configured by providing a recess in the floor of the luggage compartment that is recessed downward toward the vehicle. A bracket or the like for fixing the spare tire is attached to the bottom of the tire storage section (recess). Therefore, a certain surface rigidity is required for the bottom.

[0004] In the structure disclosed in Patent Document 1, a cross member is provided on the underside of the bottom of the tire storage compartment. The cross member is positioned to correspond to a bracket for fixing a spare tire, ensuring the surface rigidity of the bottom. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-177935 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, when a tire storage compartment is provided in the rear of an electric vehicle, the tire storage compartment is disposed behind the battery pack. However, if the tire storage compartment is disposed to avoid interference between the rear of the battery pack and the front of the tire storage compartment, the vehicle's longitudinal dimension increases. To address this, for example, the spare tire may be stored in the tire storage compartment at an angle rather than horizontally.

[0007] Furthermore, if a cross member is placed at the bottom of the tire storage section in the rear of the electric vehicle to improve its rigidity, as in the above example, there is a possibility that the rear of the battery pack may interfere with the cross member depending on its position. Therefore, the structure in the above example leaves room for improvement in terms of improving the rigidity of the tire storage section in the rear of the electric vehicle, ensuring the support rigidity for the spare tire, and preventing the spare tire from coming into contact with the battery pack.

[0008] The present invention has been made to solve the above-mentioned problems, and its object is to provide a rear structure for an electric vehicle that can improve the rigidity of the floor portion on which a spare tire is installed and can also improve the mounting rigidity of the spare tire. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a rear structure for an electric vehicle, including a battery pack disposed below a floor section of the vehicle, a storage section for storing a spare tire provided in the floor section located rearward of the battery pack, the spare tire stored in the storage section in a state inclined downward toward the rear of the vehicle, and an upper end of a front portion of an outer periphery of the spare tire located higher than an upper end of a rear portion of the battery pack in the vehicle vertical direction. In the rear structure for an electric vehicle, the storage section has a concave shape recessed downward toward the vehicle, and has a bottom and sidewalls extending upward from both lateral ends of the bottom, bead sections extending in the vehicle width direction, reinforcing members joined to the bottom and the sidewalls, the reinforcing members extending in the vehicle longitudinal direction, the outer lateral portions of the bead sections being located between the front and rear ends of the reinforcing members. [Effects of the Invention]

[0010] According to the present invention, in a rear structure of an electric vehicle, it is possible to improve the rigidity of the floor portion on which a spare tire is placed and also improve the mounting rigidity of the spare tire. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view showing an embodiment of a rear structure for an electric vehicle according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Figure 3] 2 is a perspective view of the vehicle shown in FIG. 1 with the spare tire and back panel removed, viewed from above and from the front side. FIG. [Figure 4] FIG. 4 is a top view of FIG. [Figure 5] 5 is a top view showing a state in which the holding bracket of FIG. 4 has been removed. [Figure 6] 4 is a perspective view of the rear floor panel of FIG. 3 as viewed from below the vehicle. [Figure 7] FIG. 6 is a bottom view of FIG. 5. [Figure 8]FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4. [Figure 9] FIG. 5 is a cross-sectional view taken along the line CC in FIG. 4. [Figure 10] FIG. 9 is a cross-sectional view taken along the line DD in FIG. 8. [Figure 11] 11 is an enlarged cross-sectional view showing the reinforcing member and its periphery in FIG. 10. FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along the arrow EE in FIG. [Figure 13] FIG. 12 is a cross-sectional view taken along the line FF in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, one embodiment of a rear structure for an electric vehicle according to the present invention will be described with reference to the drawings (Figs. 1 to 13). In the drawings, the direction of the arrow Fr indicates the front in the longitudinal direction of the vehicle. In the description of the embodiment, the "front (front end) and rear (rear end)" correspond to the front and rear in the longitudinal direction of the vehicle. Furthermore, the arrows R and L indicate the right and left sides when a passenger looks forward of the vehicle. Furthermore, the arrow U indicates the upward direction in the vertical direction of the vehicle.

[0013] As shown in Figures 1 and 2, in the rear structure of the electric vehicle of this embodiment, a battery pack 1 is disposed below the floor of the vehicle (Figure 2), and a tire storage section 12 capable of storing a spare tire 5 is provided in the floor located on the vehicle rear side of the battery pack 1. The spare tire 5 is stored in the tire storage section 12 in a state in which it is inclined downward toward the rear of the vehicle. In addition, the upper end of the front part of the outer peripheral surface (tread portion 5a) of the spare tire 5 is disposed above the upper end of the rear part of the battery pack 1 in the vehicle up-down direction. The rear structure will be described in detail below.

[0014] The electric vehicle of this embodiment is a type of vehicle in which a passenger compartment for passengers and a luggage compartment located behind the passenger compartment constitute a single vehicle compartment. The vehicle rear structure of this embodiment is provided with a tire storage compartment 12 capable of storing a spare tire 5 on the floor of the luggage compartment. The rear structure of this embodiment has rear side members 2, a back panel 3, a rear floor panel 10 in which the tire storage compartment 12 is provided, reinforcing members 40, 50, and a retaining bracket 20. The members will be described below.

[0015] As shown in Fig. 2, the battery pack 1 of this embodiment is disposed on the underside of the floor portion. Although detailed illustration of the battery pack 1 is omitted, it is a substantially rectangular parallelepiped device that has a predetermined dimension in the vehicle width direction and extends in the vehicle front-rear direction. The rear end of the battery pack 1 is disposed below a cross member 4 (described later) that is joined to the front portion of the rear floor panel 10, and slightly forward of the cross member 4. Note that the battery pack 1 is shown imaginarily in Fig. 2.

[0016] As shown in Figures 3 to 5, the rear side members 2 are disposed on both outer sides in the vehicle width direction at the rear of the vehicle and extend in the vehicle longitudinal direction. The rear side members 2 are highly rigid members that constitute the vehicle body frame and are made of a metal material. The rear side member 2 of this embodiment has a main body portion 2a (Figure 8) that has a substantially U-shaped cross section with an opening at the top, and a lid portion 2b that covers the opening of the main body portion 2a.

[0017] A flange (not shown) is formed at the upper end of the main body portion 2a, and the outer portion of the rear floor panel 10 in the vehicle width direction is joined to the flange by spot welding or the like. As shown in Figures 3 to 5, the lid portion 2b and the outer portion of the rear floor panel 10 in the vehicle width direction are preferably arranged so as to be continuous.

[0018] As shown in Figures 1 and 2, the back panel 3 is disposed at the rear end of the vehicle body and has a front surface 3a facing the front of the vehicle and a rear surface 3b facing the rear of the vehicle. In this example, the rear ends of the rear side members 2 are joined to the outer portions of the front surface 3a of the back panel 3 in the vehicle width direction, and the rear end of the rear floor panel 10 is joined to the middle portion of the back panel 3 in the vehicle width direction. The upper portion of the back panel 3 forms, for example, the lower portion of a back door opening (not shown). In addition, a plastic rear bumper (not shown) or the like is attached to the rear side of the back panel 3.

[0019] As shown in Figures 1 and 2, the rear floor panel 10 is one of the components constituting the floor portion located at the rear of the vehicle, and is disposed, for example, behind a rear seat (not shown). The rear floor panel 10 of this embodiment is disposed on the floor portion of a luggage compartment in the vehicle cabin. The rear floor panel 10 has an outer peripheral surface portion 11 and a tire storage portion 12. Each portion will be described below.

[0020] 3 to 5, the outer peripheral surface portion 11 of this embodiment is located at the front and outer sides of the rear floor panel 10 in the vehicle width direction, and has a U-shape with an open rear when viewed from above. The outer peripheral surface portion 11 of this example has a front outer peripheral surface portion 11a located at the front of the rear floor panel 10, and outer outer peripheral surface portions 11b, 11c located at the outer sides of the rear floor panel 10 in the vehicle width direction. The front outer peripheral surface portion 11a and the left and right outer outer peripheral surface portions 11b, 11c form the U-shape as described above.

[0021] The front outer peripheral surface portion 11a extends in the vehicle width direction. The front end of the front outer peripheral surface portion 11a may be joined to, for example, the rear portion of the front floor panel. The outer portion of the front outer peripheral surface portion 11a in the vehicle width direction is joined to the inner end of the rear side member 2 in the vehicle width direction. As shown in FIG. 4, a cross member 4 extending in the vehicle width direction is joined to the underside of the front outer peripheral surface portion 11a. The cross member 4 is a highly rigid member that constitutes the vehicle body frame, similar to the rear side member 2, and is made of a metal material. The outer portion of the cross member 4 in the vehicle width direction is joined to the inner portion of the rear side member 2 in the vehicle width direction by spot welding.

[0022] The outer outer peripheral surface portions 11b, 11c extend rearward from the outer side in the vehicle width direction at the rear of the front outer peripheral surface portion 11a and are joined to the front surface 3a of the back panel 3. The outer end portions in the vehicle width direction of the outer outer peripheral surface portions 11b, 11c are joined to the inner end of the rear side member 2. The inner end portion in the vehicle width direction of the outer outer peripheral surface portion 11b has a curved shape that is recessed toward the outside of the vehicle. This curved shape corresponds to the curved shapes of the upper ends of a left side wall portion 18 and a right side wall portion 19 of the tire storage portion 12, which will be described later.

[0023] Next, the tire storage section 12 will be described. As shown in Fig. 3, the tire storage section 12 is located in the middle of the rear floor panel 10 in the vehicle width direction, and is a portion recessed downward from the upper surface of the outer peripheral surface section 11. The tire storage section 12 is located rearward of the front outer peripheral surface section 11a and between the left and right outer outer peripheral surface sections 11b, 11c.

[0024] 2, when the spare tire 5 is stored in the tire storage section 12, the front portion of the tread portion 5a of the spare tire 5 is inclined so as to be positioned higher than the rear portion. That is, the spare tire 5 is disposed so as to be inclined downward toward the rear of the vehicle when viewed in the vehicle width direction.

[0025] The tire storage section 12 of this embodiment has a bottom 14, a left side wall 18, and a right side wall 19. Each section will be described below.

[0026] As shown in FIGS. 3 and 9 , the bottom portions 14, 17 of the tire storage compartment 12 have an inclined portion 14 and a flat portion 17. The inclined portion 14 is a portion that extends from the rear end of the front outer peripheral surface portion 11a toward the rear of the vehicle, sloping downward. The flat portion 17 is a substantially flat portion that extends horizontally toward the rear of the vehicle from the rear end of the inclined portion 14. As shown in FIG. 3 , a flange 17a is provided at the rear end of the flat portion 17, protruding upward from the rear end. The flange 17a is joined to the lower part of the front surface 3a of the back panel 3 by spot welding or the like. A retaining bracket 20 for holding the spare tire 5 is joined to the inclined portion 14 of the bottom. Details of the retaining bracket 20 will be described later.

[0027] The left side wall 18 is a wall extending downward from the inner end of the left outer peripheral surface 11b in the vehicle width direction toward the bottom. The left side wall 18 has a left curved portion 18a and a left vertical wall portion 18b. The inner wall of the left curved portion 18a is curved so as to be recessed outward in the vehicle width direction. As shown in FIG. 1, the left curved portion 18a corresponds to the curved shape of the tread portion 5a of the spare tire 5. In other words, when the spare tire 5 is stored in the tire storage portion 12, the left curved portion 18a is configured to cover the tread portion 5a of the spare tire 5 from the radially outer side of the spare tire 5.

[0028] The left vertical wall portion 18b extends rearward from the rear end of the left curved portion 18a. The rear end of the left vertical wall portion 18b is joined to the back panel 3. For example, the rear end of the left vertical wall portion 18b extends in the vertical direction of the vehicle, and as shown in Fig. 3, a flange 18c is formed at the rear end so as to protrude outward in the vehicle width direction, and the flange 18c is joined to the front surface 3a of the back panel 3 by spot welding or the like.

[0029] The right side wall 19 is a wall that extends downward from the inner end of the right outer peripheral surface 11c in the vehicle width direction toward the bottom. Similar to the left side wall 18, the right side wall 19 has a right curved portion 19a and a right vertical wall portion 19b. The right curved portion 19a is a wall that is formed symmetrically with the left curved portion 18a.

[0030] That is, the inner wall of the right curved portion 19a is curved so as to be recessed outward in the vehicle width direction. The right curved portion 19a corresponds to the curved surface shape of the tread portion 5a of the spare tire 5. When the spare tire 5 is stored in the tire storage portion 12, the right curved portion 19a is configured to cover the tread portion 5a of the spare tire 5 from the radially outer side of the spare tire 5.

[0031] The right vertical wall portion 19b extends rearward from the rear end of the right curved portion 19a. Similar to the left vertical wall portion 18b, the rear end of the right vertical wall portion 19b is joined to the back panel 3. The rear end of the right vertical wall portion 19b extends in the vertical direction of the vehicle, and a flange 19c that protrudes outward in the vehicle width direction is formed at the rear end, and the flange 19c is joined to the front surface 3a of the back panel 3 by spot welding or the like.

[0032] A central bead portion 16 (bead portion) extending in the vehicle width direction is provided at the bottom of the tire storage portion 12, and reinforcing members 40, 50 that are joined to the bottom and left and right outer wall portions 18, 19 ((side wall portions)) are joined to the outer portions of the central bead portion 16 in the vehicle width direction. The reinforcing members 40, 50 extend in the fore-and-aft direction of the vehicle, and the outer portions of the central bead portion 16 in the vehicle width direction are located between the front and rear ends of the reinforcing members 40, 50.

[0033] The central bead portion 16 is located in the middle of the inclined portion 14 at the bottom of the tire storage compartment 12 in the vehicle longitudinal direction. The central bead portion 16 extends linearly in the vehicle width direction. The left side of the central bead portion 16 is connected to the outermost lower part of the left curved portion 18a, and the right side is connected to the outermost lower part of the right curved portion 19a. Here, "outermost" refers to the curved portions 18a, 19a located at the outermost positions in the vehicle width direction.

[0034] 8 and 9, the central bead portion 16 has a concave cross section that is recessed downward from the bottom of the vehicle. The outer side of the central bead portion 16 in the vehicle width direction is covered by the outer side of a retaining bracket 20, which will be described later. The relationship between the retaining bracket 20 and the central bead portion 16 will be described later.

[0035] In this embodiment, the concave bottom surface 16a of the central bead portion 16 is formed to be substantially flat. A front surface 16b is formed at the front portion of the bottom surface 16a, and the upper end of the front surface 16b is connected to the main surface of the inclined portion 14 at the bottom of the tire storage portion 12. Similarly, a rear surface 16c is formed at the rear portion of the bottom surface 16a, and the upper end of the rear surface 16c is connected to the main surface of the inclined portion 14 at the bottom of the tire storage portion 12. The front surface 16b slopes upward toward the front of the vehicle. The rear surface 16c slopes upward toward the rear of the vehicle. Here, the main surface refers to the portion of the inclined portion 14 where the front bead portion 15 and the central bead portion 16 are not formed.

[0036] In addition, a front bead portion 15 is provided at the bottom of the tire storage portion 12 of this embodiment. The front bead portion 15 is disposed forward of and spaced from the center bead portion 16. In this example, the front bead portion 15 is disposed forward of the center of the inclined portion 14 in the vehicle longitudinal direction.

[0037] Furthermore, the vehicle width directional middle portion of the front bead portion 15 extends substantially linearly in the vehicle width direction. The vehicle width directional outer portion of the front bead portion 15 curves forward as it moves outward in the vehicle width direction. The left outer portion of the front bead portion 15 is connected to the lower part of the left curved portion 18a of the left side wall portion 18, and the right outer portion of the front bead portion 15 is connected to the lower part of the right curved portion 19a of the right side wall portion 19.

[0038] 5, the front bead portion 15 includes a front wall 15b that protrudes upward from the bottom of the tire storage compartment 12, a rear wall 15c that protrudes upward from the bottom and is spaced apart from the front wall 15b, and an upper surface 15a that connects the upper end of the front wall 15b to the upper end of the rear wall 15c. The upper surface 15a and the front wall 15b or the rear wall 15c form a ridge line 15d. Furthermore, the front bead portion 15 has a convex shape in which a middle portion in the vehicle width direction protrudes toward the rear of the vehicle. That is, the middle portion in the vehicle width direction of the front wall 15b is recessed rearward compared to the outer portions, and the middle portion in the vehicle width direction of the rear wall 15c protrudes rearward compared to the outer portions.

[0039] Next, the reinforcing members 40, 50 will be described. As shown in Figures 6 and 7, the reinforcing members 40, 50 are arranged on the vehicle width direction outer sides of the central bead portion 16, and are joined to the bottom and the left and right outer wall portions 18, 19 of the tire storage compartment 12. The reinforcing members 40, 50 extend in the vehicle front-rear direction, and the vehicle width direction outer sides of the central bead portion 16 are arranged between the front and rear ends of the reinforcing members 40, 50. The reinforcing members 40, 50 will be described below.

[0040] The reinforcing members 40, 50 are members made of a metal material and are arranged on both sides (left and right sides) in the vehicle width direction on the underside (outside the vehicle compartment) of the bottom of the tire storage section 12. The left reinforcing member 40 is joined to the left outer side in the vehicle width direction of the inclined portion 14 of the bottom of the tire storage section and to the lower part of the left side wall 18, and the right reinforcing member 50 is joined to the right outer side of the inclined portion 14 and the lower part of the right side wall 19.

[0041] The left reinforcing member 40 is a member that extends in the vehicle longitudinal direction as a whole, and has a lower surface portion 41, a protruding portion 42, and an outer portion 43. As shown in Figures 7 and 12, the lower surface portion 41 straddles the central bead portion 16 in the vehicle direction, and is formed to correspond to the shape of the lower surface side of the central bead portion 16.

[0042] As described above, the central bead portion 16 has a bottom surface 16a, a front surface 16b, and a rear surface 16c. As a result, when viewed from inside the vehicle, a concave shape recessed downward is formed. That is, when the central bead portion 16 is viewed from outside the vehicle, the bottom surface 16a, the front surface 16b, and the rear surface 16c form a convex shape that protrudes downward. That is, the lower surface portion 41 of the left reinforcing member 40 has a convex shape that protrudes downward, and is joined to the left side of the bottom of the tire storage portion 12.

[0043] 6, 7, and 12, the front end of the underside 41 of the left reinforcing member 40 is located forward of the front surface 16b of the central bead portion 16, and this front end is joined by, for example, spot welding, to the underside of the inclined portion 14 located forward of the front surface 16b. The rear end of the underside of the left reinforcing member 40 is located rearward of the rear surface 16c of the central bead portion 16, and this rear end is joined by, for example, spot welding, to the underside of the inclined portion 14 located rearward of the rear surface 16c. An intermediate portion of the underside 41 of the left reinforcing member 40 in the vehicle longitudinal direction is located lower than the front and rear ends, and is joined by, for example, spot welding, to the underside of the bottom surface 16a of the central bead portion 16.

[0044] 6 and 7, the protrusion 42 is disposed so as to intersect with the end of the central bead portion 16 in the vehicle width direction, and is disposed at the corner formed by the bottom of the tire storage portion 12 and the left and right outer wall portions 18, 19. The protrusion will be described in detail below.

[0045] The protruding portion 42 of the left reinforcement member 40 is a portion disposed on the outer side of the lower surface portion 41 in the vehicle width direction and protrudes further downward than the lower surface portion 41. As shown in FIG. 7 , the protruding portion 42 has an inner wall 42a, an outer wall 42b, a front wall 42c, a rear wall 42d, and a bottom portion 42e. The inner wall 42a extends downward from the inner end of the lower surface portion 41 in the vehicle width direction. The outer wall 42b is a vertical wall disposed on the outer side of the inner wall 42a in the vehicle width direction with a gap therebetween and faces outward in the vehicle width direction. The front wall 42c connects the front end of the inner wall 42a to the front end of the outer wall 42b and has a curved shape that convexly faces forward. The rear wall 42d connects the rear end of the inner wall 42a to the rear end of the outer wall 42b and has a curved shape that convexly faces rearward.

[0046] 7, the front portion of the inner wall 42a is located in front of the lower surface portion 41 and below the front wall 16b of the central bead portion 16, and bulges inward in the vehicle width direction. The rear portion of the inner wall 42a is located behind the lower surface portion 41 and below the rear wall 16c of the central bead portion 16, and bulges inward in the vehicle width direction. The middle portion of the inner wall 42a in the vehicle front-rear direction is located below the bottom surface 16a of the central bead portion 16, and is recessed outward in the vehicle width direction.

[0047] The bottom 42e is a plate-shaped portion disposed at the lower end of the protruding portion 42 and is connected to the lower ends of the inner wall 42a, outer wall 42b, front wall 42c, and rear wall 42d. The protruding portion 42 of this embodiment has a hollow structure formed by the inner wall 42a, outer wall 42b, front wall 42c, rear wall 42d, and bottom 42e. The outer wall 42b is disposed on the lower side of the left side wall 18, outside the outer end of the inclined portion 14 of the tire storage portion 12 in the vehicle width direction. The lower part of the left side wall 18 is curved and connected to the outer end of the inclined portion 14. In other words, the corner formed by the left side wall 18 and the bottom has a curved shape. The outer wall 42b of the protruding portion 42 is disposed on the lower side of the curved shape.

[0048] The outer portion 43 of the left reinforcing member 40 is a portion that is located outward in the vehicle width direction from the protruding portion 42 and is curved along the curved shape that constitutes the corner. The outer portion 43 is joined to the corner by spot welding.

[0049] 6 and 7, the right-side reinforcing member 50, like the left-side reinforcing member 40, is a member that extends in the longitudinal direction of the vehicle as a whole, and has a lower surface portion 51, a protruding portion 52, and an outer portion 53. In this embodiment, the left-side reinforcing member 40 and the right-side reinforcing member 50 are preferably configured symmetrically.

[0050] As described above, by providing the central bead portion 16 and the left and right reinforcing members 40, 50, it is possible to improve the strength of the spare tire storage compartment 12. By providing the central bead portion 16 in the downwardly recessed tire storage compartment 12, stress tends to concentrate in the central bead portion 16. Furthermore, by providing the left and right reinforcing members 40, 50, it is possible to pinpoint and reinforce the locations where stress tends to concentrate. With the above configuration, for example, it is possible to suppress unnecessary weight increase by not providing a framework member such as a cross member to support the bottom of the tire storage compartment 12. This makes it possible to configure a compact reinforcing structure.

[0051] Therefore, according to this embodiment, in the rear structure of the electric vehicle, it is possible to improve the rigidity of the floor portion on which the spare tire 5 is placed and also improve the mounting rigidity of the spare tire 5.

[0052] This improves the rigidity of the bottom of the tire storage area 12, to which the retaining bracket 20 for retaining the spare tire 5 is joined. The relationship between the left and right reinforcing members 40, 50 and the retaining bracket 20 will be described later.

[0053] Furthermore, in this embodiment, as described above, by providing the protrusions 42, 52 on the left and right reinforcing members 40, 50, the protrusions 42, 52 function as rib structures, thereby ensuring the rigidity and strength of the left and right reinforcing members 40, 50. Furthermore, by increasing the rigidity and strength of the left and right reinforcing members 40, 50, it is possible to improve the rigidity and strength of the tire storage section 12. As a result, it is possible to improve the rigidity of the floor portion on which the spare tire 5 is placed, and also improve the mounting rigidity of the spare tire 5.

[0054] Next, the retaining bracket 20 for installing the spare tire 5 in the tire storage section 12 will be described. The retaining bracket 20 is a bracket for holding the inclined spare tire 5 as described above, and is a highly rigid member made of a metal material. The retaining bracket 20 is joined to the inclined portion 14 at the bottom of the tire storage section 12, and has a retaining portion 21, a front wall portion 22, outer wall portions 23 and 24, and reinforcing wall portions 25 and 26, as shown in FIGS. 3 and 4 .

[0055] The retaining portion 21 is disposed above the floor portion with a gap therebetween and retains the radial center portion of the spare tire 5. The front wall portion 22 extends from the retaining portion 21 toward the front of the vehicle, and its front end is joined to the floor portion. The outer wall portions 23, 24 extend from the retaining portion 21 to both outer sides in the vehicle width direction, and their side ends are joined to the floor portion. The reinforcing wall portions 25, 26 connect the front wall portion 22 to the outer wall portions 23, 24 on both sides.

[0056] The retaining bracket 20 of this embodiment has a generally semiconical shape with the retaining portion 21 at its apex, and has a generally semicircular outline when viewed from above. In other words, the retaining bracket 20 has a shape like a cone with the rear portion cut off. The rear end of the retaining bracket 20 extends substantially vertically.

[0057] As shown in FIG. 2 , the holding portion 21 is a plate-shaped portion that is disposed above the vehicle with a gap between it and the intermediate portion of the inclined portion 14 at the bottom of the tire storage portion 12 in the vehicle longitudinal direction. In this example, the holding portion 21 is plate-shaped and parallel to the inclined portion 14. Furthermore, a protruding portion that protrudes upward is provided at the rear of the holding portion 21, at the center in the vehicle width direction, and the tip of the protruding portion forms a flat surface that is parallel to the inclined portion 14. A through-hole 21a is formed in the center of the protruding portion, and a cylindrical metal holding member 28 is detachably attached to the through-hole 21a. The holding member 28 is attached to the protruding portion so that the longitudinal direction of the holding member 28 is perpendicular to the flat surface of the protruding portion. The center of the wheel 5d of the spare tire 5 is detachably attached to the holding member 28.

[0058] As described above, the front wall portion 22 extends from the retaining portion 21 toward the front of the vehicle, and its front end is joined to the floor portion. As shown in Figures 3 and 4, a front welded portion 22c is provided at the front end.

[0059] The front wall portion 22 of this embodiment extends from the front of the retaining portion 21 toward the inclined portion 14 of the tire storage portion 12, and is inclined downward toward the front of the vehicle. The front wall portion 22 is formed with a longitudinal bead 22a and sub-beads 22b arranged on both sides of the longitudinal bead 22a in the vehicle width direction. The longitudinal bead 22a is a long bead formed over the entire longitudinal area of ​​the front wall portion 22, and extends from the front of the retaining portion 21 to the front end of the retaining bracket 20. The sub-beads 22b are shorter than the longitudinal bead 22a, and the front ends of the sub-beads 22b are arranged on both sides of the front end of the longitudinal bead 22a in the vehicle width direction.

[0060] The front welds 22c are provided at the front end of the longitudinal bead 22a and at the front ends of the sub-beads 22b on both sides. That is, in this example, three front welds 22c are arranged at intervals from one another in the vehicle width direction. The front welds 22c are spot welded to the inclined portion 14 of the bottom of the tire storage area 12. The three front welds 22c are also spot welded to the front end of a front bead portion 15 (described later) provided on the inclined portion 14 of the bottom.

[0061] Furthermore, the front wall portion 22 of the retaining bracket 20 is joined to the upper surface portion 15a adjacent to a ridge line 15d that corresponds to the convex shape of the front bead portion 15. In this embodiment, as shown in Figures 3 and 4, front welds 22c of the front wall portion 22 are spot-welded to the upper surface portion 15a adjacent to the ridge line 15d formed by the front wall 15b and the upper surface portion 15a. That is, three front welds 22c are spot-welded to the upper surface portion 15a along the ridge line 15d.

[0062] Next, we will explain the outer wall portions 23, 24. As described above, the outer wall portions 23, 24 extend outward in both vehicle width directions from the retaining portion 21, and their side ends are joined to the floor portion, with outer welded portions 23c, 24c provided at the side ends.

[0063] The left outer wall 23 extends from the left side of the retaining portion 21 in the vehicle width direction toward the inclined portion 14 of the tire storage portion 12, and extends at an angle downward on the vehicle as it extends outward in the vehicle width direction. A widthwise bead 23a is formed on the left outer wall 23. The widthwise bead 23a is an elongated bead formed over the entire longitudinal area of ​​the outer wall 23, and extends from the left side of the retaining portion 21 in the vehicle width direction to the left end of the retaining bracket 20.

[0064] The left outer welded portion 23c is provided at the left end of the widthwise bead 23a and on the front and rear sides of the widthwise bead 23a. The left outer welded portion 23c is spot welded to the left end of the inclined portion 14 at the bottom of the tire storage area 12.

[0065] The right outer wall 24 extends from the right side of the retaining portion 21 in the vehicle width direction toward the inclined portion 14 of the tire storage portion 12, and extends at an angle downward toward the vehicle width direction. Similar to the left outer wall 24, the right outer wall 24 has a widthwise bead 24a formed thereon. The left and right outer walls 23, 24 may be configured symmetrically. Similar to the left outer weld 23c, the right outer weld 24c is provided at the right end of the widthwise bead 24a and on the front and rear sides of the widthwise bead 24a, and is spot-welded to the right end of the inclined portion 14 at the bottom of the tire storage portion 12. Note that the left and right outer walls 23, 24 are not limited to being symmetrical, and various modifications are possible to accommodate the shape of the rear floor panel 10, etc.

[0066] 9, as described above, outer welds 23c are arranged side by side in the vehicle front-to-rear direction on the outer end of the left outer wall 23 of the retaining bracket 20. Of the outer welds 23c on the left outer wall 23, the foremost outer weld 23c is spot welded to the main surface of the inclined portion 14 located forward of the front surface 16b of the central bead 16. The last outer weld 23c is spot welded to the main surface of the inclined portion 14 located rearward of the rear surface 16c of the central bead 16.

[0067] The middle outer weld portion 23c is spot welded to the outer side in the vehicle width direction of the bottom surface 16a of the central bead portion 16. That is, the outer weld portion 23c provided on the widthwise bead 23a is spot welded to the bottom surface 16a of the central bead portion 16. The outer weld portion 23c of the outer wall portion 23 is joined to the central bead portion 16, the front side of the central bead portion 16, and the rear side of the central bead portion 16, while covering the second bead from above, that is, while straddling the central bead portion 16 in the front-to-rear direction. The outer weld portion 24c of the right outer wall portion 24 is arranged in a similar manner.

[0068] As described above, the reinforcing walls 25, 26 are walls that connect the front wall 22 to the outer wall portions 23, 24 on both sides. In this example, the reinforcing walls 25, 26 include a left reinforcing wall 25 that connects the front wall 22 to the left outer wall portion 23, and a right reinforcing wall 26 that connects the front wall 22 to the right outer wall portion 24.

[0069] The front end of the left reinforcing wall portion 25 curves toward the rear of the vehicle as it moves toward the left outer side in the vehicle width direction. The front end of the left reinforcing wall portion 25 may be provided with a weld portion 25a that is welded to the front bead portion 15. Similarly, the front end of the right reinforcing wall portion 26 curves toward the rear of the vehicle as it moves toward the right outer side in the vehicle width direction. In addition, the front end of the right reinforcing wall portion 26 may also be provided with a weld portion 26a that is welded to the front bead portion 15.

[0070] Here, the relationship between the central bead portion 16 and the outer wall portions 23, 24 of the retaining bracket 20 will be described. The length in the front-to-rear direction of the outer wall portions 23, 24 of the retaining bracket 20 is set to be longer than the length in the front-to-rear direction of the central bead portion 16. In addition, it is preferable that the outer wall portions 23, 24 are joined by spot welding to the front and rear portions of the central bead portion 16 while covering the central bead portion 16 from above.

[0071] 11 to 13, in this embodiment, the left and right reinforcing members 40, 50 are joined to the underside of the central bead portion 16 to which the outer welded portions 23c, 24c of the retaining bracket 20 are spot-welded. In this example, as shown in Fig. 12, the outer welded portions 23c, 24c of the retaining bracket 20 and the left and right reinforcing members 40, 50 are joined in a state in which they sandwich the bottom surface 16a of the central bead portion 16 located at the bottom of the tire storage section 12. By providing the reinforcing members 40, 50 in this manner, it is possible to further enhance the effect of improving the rigidity of the inclined portion 14 by the central bead portion 16.

[0072] 4, the retaining bracket 20 of this embodiment may have a rear wall 30 that extends downward from the rear of the retaining portion 21 and is joined to the floor portion. For example, the rear wall 30 may have a vertical wall 31 that extends downward from the rear of the retaining portion 21 and a joint surface 35 that extends rearward from the lower end of the vertical wall 31. The joint surface 35 may extend along the inclination direction of the inclined portion 14 at the bottom of the tire storage portion 12 and be spot-welded to the inclined portion 14. This further improves the rigidity of the retaining bracket 20, and the provision of the joint surface 35 may also improve the rigidity of the bottom of the tire storage portion 12.

[0073] When the spare tire 5 is stored in the tire storage section 12, the holding member 28 is inserted into the center of the wheel 5d of the spare tire 5. In addition, in the stored spare tire 5, the lower end of the tread portion 5a located at the front is positioned slightly above the front outer peripheral surface portion 11a, and the lower end of the tread portion 5a located at the rear is positioned above the flat portion 17 at the bottom of the tire storage section 12 with a gap therebetween.

[0074] The spare tire 5 has corners (shoulders 5c) connecting the tread 5a and the side surfaces (sidewalls 5b). The shoulders 5c, which are located at the rear of the spare tire 5, are placed on the rear end of the inclined portions 14 of the tire storage compartment 12. This allows the spare tire 5 to be stored in the tire storage compartment 12 while maintaining an inclined posture.

[0075] For example, a load acting downward due to the weight of the spare tire 5 is transmitted from the retaining portion 21 to the bottom of the tire storage portion 12 via, for example, the outer wall portions 23, 24. Therefore, in this embodiment, stress is concentrated at the outer welded portions 23c, 24c of the left and right outer wall portions 23, 24. In response to this, by providing the central bead portion 16 at the bottom where the outer welded portions 23c, 24c are welded, and further by providing the left and right reinforcing members 40, 50, it is possible to improve the strength of the areas where stress is concentrated. As a result, it is possible to improve the rigidity of the floor portion on which the spare tire 5 is placed, and also to improve the mounting rigidity of the spare tire 5.

[0076] Furthermore, according to this embodiment, in the rear structure of the electric vehicle, it is possible to improve the rigidity of the floor portion on which the spare tire 5 is placed and to improve the mounting rigidity of the spare tire 5. Furthermore, by improving the rigidity of the floor portion, when an impact load such as a rear-end collision is received, the battery pack 1 disposed in front of the spare tire 5 stored in the tire storage section 12 can be effectively protected from the impact load.

[0077] In addition, in this embodiment, as shown in Figures 3, 4 and 10, the longitudinal bead 22a and the widthwise beads 23a, 24a have a concave cross-sectional shape, and the depth of these concave shapes is configured to become deeper as they approach the bottom from the retaining portion 21.

[0078] By forming the longitudinal beads 22a and the widthwise beads 23a, 24a in this manner, the longitudinal rigidity of the longitudinal beads 22a and the widthwise beads 23a, 24a is improved, and the rigidity against loads acting in the longitudinal direction and the widthwise direction of the vehicle is improved. In other words, the longitudinal beads 22a and the widthwise beads 23a, 24a can effectively improve the rigidity of the retainer bracket 20.

[0079] For example, the depth of the concave shape of the widthwise beads 23a, 24a located on the outer side in the vehicle width direction is deeper than that of the widthwise beads 23a, 24a located on the inner side in the vehicle width direction. As described above, the outer welded portions 23a, 24c provided at the ends of the widthwise beads 23a, 24a are welded to the bottom surface 16a of the central bead portion 16, so the concave shape of the widthwise beads 23a, 24a located on the outer side in the vehicle width direction is deeper than the concave shape of the central bead portion 16. By forming the widthwise beads 23a, 24a in this manner, the rigidity of the retaining bracket 20 and the central bead portion 16 in the vehicle width direction is improved. Furthermore, because the reinforcing members 40, 50 are joined to the lower surface side of the inclined portion 14 as described above, the rigidity of the inclined portion 14 is further improved.

[0080] Furthermore, it is preferable that a sub-bead 22b extending in the vehicle longitudinal direction is provided in a portion of the front wall portion 22 of the retaining bracket 20 that is joined to the front bead portion 15. In this embodiment, as shown in Figures 3, 4, and 10, front welds 22c where the front wall portion 22 is welded to the front bead portion 15 are provided in front of the longitudinal bead 22a and in front of the sub-beads 22b that are arranged on both sides thereof. This improves the rigidity of the front welds 22c, and also improves the retention rigidity of the spare tire 5.

[0081] According to this embodiment, the rear of the vehicle is effectively reinforced, so that when an impact load is applied due to a rear-end collision or the like, deformation of the floor portion due to the inertia of the spare tire 5 can be effectively suppressed. As a result, the battery pack 1 located in front of the spare tire 5 can be effectively protected.

[0082] The description of the present embodiment is merely an example for explaining the present invention, and does not limit the invention described in the claims. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

[0083] For example, the bottom of the tire storage section 12 in this embodiment has the inclined portion 14 and the flat portion 17, but is not limited to this. For example, the bottom may be configured as a flat surface. [Explanation of symbols]

[0084] 1 Battery pack 2 Rear side members 2a Main body 2b Lid 2c flange 3 Back Panel 4 cross members 5 spare tires 5a Tread area 5b Sidewall 5c Shoulder 5d wheels 10 Rear floor panel 11 Outer peripheral surface 11a Front outer peripheral surface 11b Left outer peripheral surface 11c Right outer peripheral surface 12 Tire storage area 14 Slope 15 Front bead 15a Top part 15b Front wall 15c back wall 15d Ridgeline 16 Center bead 16a Bottom 16b Front 16c rear 17 Plane part 17a flange 18 Left side wall 18a Left curved section 18b Left vertical wall section 18c flange 19 Right side wall 19a Right curved section 19b Right vertical wall section 19c flange 20 Retaining bracket 21 Holding part 21a Through hole 22 Front wall 22a Front and rear bead 22b Subbead 22c Front weld 23 Left outer wall 23a Width direction bead 23c Outside weld 24 Right outer wall 24a Width direction bead 24c Outside weld 25 Left side reinforced wall 25a Welded section 26 Right side reinforcement wall 26a Welded section 28 Retaining member 30 Rear side wall 31 Vertical Wall 35 Joint surface part 40 Left side reinforcement member 41 Bottom part 42 Protrusion 42a Internal wall 42b outer wall 42c front wall 42d back wall 42e bottom 43 Outer part 50 Right side reinforcement member 51 Bottom part 52 Protrusion 53 Outer part

Claims

1. The battery pack is located below the floor of the vehicle. a storage space capable of storing a spare tire is provided in the floor portion located on the vehicle rear side of the battery pack; a rear structure for an electric vehicle, wherein the spare tire is stored in the storage section in a state inclined downward toward the rear of the vehicle, and an upper end of a front portion of an outer circumferential portion of the spare tire is disposed higher than an upper end of a rear portion of the battery pack in a vehicle up-down direction, The storage compartment has a recessed shape recessed downwardly of the vehicle and includes a bottom and sidewalls extending upward from both vehicle width ends of the bottom, The bottom portion is provided with a bead portion extending in the vehicle width direction, a reinforcing member joined to the bottom portion and the side wall portion is joined to an outer portion of the bead portion in the vehicle width direction, a reinforcing member extending in a longitudinal direction of the vehicle, and a vehicle width direction outer portion of the bead portion being disposed between a front end and a rear end of the reinforcing member;

2. the reinforcing member has a protruding portion that protrudes downward and extends in the vehicle front-rear direction, 2. The rear structure of an electric vehicle according to claim 1, wherein the protrusion is arranged so as to intersect with an end of the bead portion in the vehicle width direction, and is arranged at a corner formed by the bottom and the side wall of the storage portion.

3. a holding bracket for holding the spare tire is attached to the bottom of the storage section; 3. The rear structure of an electric vehicle according to claim 1, wherein the reinforcing member and the retaining bracket are joined to the floor portion with the bead portion sandwiched between them.

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