Structure for lower portion of vehicle

Abstract

The present invention comprises: a door pocket part that has therein a guide rail for guiding a sliding door; a pair of side members that are disposed inward of the door pocket part in the vehicle width direction, that extend in the vehicle front-back direction, and that are disposed side-by-side in the vehicle width direction; a cross member that extends in the vehicle width direction and that connects the pair of side members; and an on-vehicle device that is disposed between the pair of side members and that overlaps with the door pocket part in the vertical direction, wherein the door pocket part, the side members, and the cross member are disposed side-by-side in the vehicle width direction so as to overlap in a side view.

Description

Vehicle undercarriage

[0001] The present invention relates to a vehicle undercarriage equipped with a door pocket for a sliding door.

[0002] In electric vehicles such as electric cars and hybrid vehicles that have a traction motor that drives the wheels, a battery that supplies power to the traction motor is mounted under the floor of the vehicle. Patent Document 1 discloses a sliding door for such an electric vehicle that slides in the fore-and-aft direction of the vehicle to open and close the entrance and exit.

[0003] Japanese Patent Application Publication No. 2019-202616

[0004] However, when a sliding door is used in an electric vehicle such as the one described above, the sliding door pocket and the battery, which are arranged side by side in the vehicle width direction, overlap in a side view, so there is a risk that the door pocket will come into contact with the battery on the inside of the vehicle width direction due to the collision load when the sliding door is hit from the outside.

[0005] In the above-mentioned Patent Document 1, the collision load when the vehicle is hit on the side is transmitted to and absorbed by the entire vehicle via the side sill stiffeners and side sills located on the outside of the door pocket in the vehicle width direction, thereby protecting the battery. However, there is a problem in that the collision load is not sufficiently distributed, and the door pocket may come into contact with the battery.

[0006] The present invention was made in consideration of the above situation, and aims to provide a vehicle undercarriage structure that can prevent the sliding door pocket from coming into contact with a battery supported under the vehicle in the event of a collision with the side of the vehicle.

[0007] The above object of the present invention is achieved by the following configuration: [1] A vehicle undercarriage structure comprising: a door pocket having a guide rail for guiding a sliding door therein, a pair of side members disposed on the inside of the door pocket in the vehicle width direction, extending in the front-rear direction of the vehicle and arranged side by side in the vehicle width direction, a cross member extending in the vehicle width direction and connecting the pair of side members, and on-board equipment disposed between the pair of side members and overlapping with the door pocket in the vertical direction, wherein the door pocket, the side members, and the cross member are arranged side by side in the vehicle width direction so as to overlap in a side view.

[0008] According to the present invention, the collision load transmitted to the door pocket due to a collision with the side of the vehicle can be absorbed by a pair of side members and a cross member that are arranged side by side in the vehicle width direction so as to overlap with the door pocket portion in a side view. This prevents the door pocket portion to which the collision load is transmitted from collapsing inward in the vehicle width direction, and prevents the pair of side members from interfering with on-board equipment.

[0009] FIG. 1 is a side view of an entire vehicle body having a vehicle undercarriage. FIG. 2 is a bottom view of the vehicle body showing the vehicle undercarriage. FIG. 3 is a bottom perspective view showing the vehicle undercarriage. FIG. 4 is an enlarged view of a main part of FIG. 3. FIG. 5 is an upper perspective view of a main part showing a lower rail. FIG. 6 is a lower perspective view of a main part showing a lower rail. FIG. 7 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 8 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 9 is a cross-sectional view taken along line C-C in FIG. 1.

[0010] Hereinafter, a vehicle undercarriage according to an embodiment of the present invention will be described with reference to the drawings. This embodiment shows only one example of the present invention, and the present invention is not limited to this embodiment. Various modifications and improvements can be made to this embodiment, and such modifications and improvements can also be included in the present invention.

[0011] In this embodiment, the direction of travel of the vehicle is referred to as "front," and the rear of the vehicle when traveling backward is referred to as "rear." The left side of the vehicle in the direction of travel is referred to as "left," and the right side of the vehicle in the direction of travel is referred to as "right." Furthermore, the left-right direction and the vehicle width direction are synonymous, and the front-rear direction and the vehicle direction are synonymous.

[0012] Fig. 1 is a side view of an entire vehicle body having a vehicle undercarriage. Fig. 2 is a bottom view of the vehicle body showing the vehicle undercarriage. As shown in Fig. 1, a vehicle 100 has a cabin 20 in which occupants ride. The cabin 20 is supported by a chassis frame 10 that forms the framework of the vehicle's underside, and a drive battery 2 that supplies power to a traction motor (not shown) is disposed as an on-board device below a floor panel 25 of the cabin 20. The drive battery 2 is supported by the chassis frame 10.

[0013] A front door opening 21 and a rear door opening 22 are arranged side by side in the front-to-rear direction on the side of the cabin 20. The front door opening 21 and the rear door opening 22 are separated by a center pillar 23 extending in the vertical direction, and the rear door opening 22 is opened and closed by a sliding door 24 that slides in the front-to-rear direction.

[0014] The lower end of the sliding door 24 is slidably supported by a lower rail 33 disposed below the rear door opening 22. The upper end of the sliding door 24 is supported by an upper rail 26 disposed above the rear door opening 22. The vertical midpoint of the rear end of the sliding door 24 is supported by an intermediate rail 27 extending rearward from the rear end of the rear door opening 22.

[0015] (Vehicle Underbody Structure) The vehicle underbody structure will now be described with reference to Figures 2 to 9. Figure 3 is a bottom perspective view showing the vehicle underbody structure. Figure 4 is an enlarged view of the main parts of Figure 3. Figure 5 is an upper perspective view of the main parts of the lower rail. Figure 6 is a lower perspective view of the main parts of the lower rail. Figure 7 is a cross-sectional view taken along line A-A in Figure 1. Figure 8 is a cross-sectional view taken along line B-B in Figure 1. Figure 9 is a cross-sectional view taken along line C-C in Figure 1.

[0016] The vehicle undercarriage structure on the underside of the vehicle 100 includes a door pocket (door pocket portion) 30 in which a lower rail 33 is provided, a chassis frame 10, a driving battery 2, and a side sill 28 which is a skeletal member arranged on the lower end side of the side of the cabin 20 and supports the door pocket 30.

[0017] The door pocket 30 is a box-shaped member that houses the sliding door arm 24A provided at the lower end of the sliding door 24. The door pocket 30 has a generally U-shaped cross section that is open on the outer side in the vehicle width direction. The door pocket 30 has a door pocket upper 31 that forms the top surface, and a door pocket lower 32 that has a generally L-shaped cross section and forms the bottom surface and the inner side in the vehicle width direction.

[0018] The door pocket upper 31 is a plate-like member disposed between the side members 11 (described later) and the side sills 28 disposed on the left and right outer sides of the side members 11, and constitutes the upper surface of the door pocket 30. The upper surface of the door pocket upper 31 also functions as a side step used by occupants when getting into the cabin through the rear door opening 22. The upper surface of the door pocket upper 31 has a concave-convex surface formed by arranging a plurality of convex portions 31a extending in the vehicle width direction in the front-rear direction, thereby increasing strength. This configuration can be seen in FIG. 5, etc.

[0019] A lower rail 33 is attached and fixed to the underside of the door pocket upper 31. As shown in FIG. 6 , the lower rail 33 is a rail member extending in the front-rear direction and has a generally U-shaped cross section that opens downward. The front end of the lower rail 33 is curved inward in the vehicle width direction. As shown in FIG. 8 , a lateral roller 24B that rotates about a vertical axis is assembled inside the lower rail 33, and the lateral roller 24B rolls along the lower rail 33. A sliding door arm 24A is attached to the lateral roller 24B via a connecting member (not shown). The sliding door arm 24A is connected to the sliding door 24 via a connecting member (not shown).

[0020] The door pocket lower 32 extends in the front-rear direction along the lower rail 33, has a generally L-shaped cross section, and covers the lower side of the lower rail 33 and the inner side in the vehicle width direction. A door pocket lower protrusion 32A is formed at the front end of the door pocket lower 32, protruding inward in the vehicle width direction along the front end of the lower rail 33. This configuration can be seen in FIGS. 3 and 4 . The door pocket lower 32 is formed shorter in the vehicle width direction than the door pocket upper 31 and is positioned closer to the outer side of the door pocket upper 31 in the vehicle width direction. This configuration can be seen in FIG. 9 . The door pocket lower protrusion 32A at the front end of the door pocket lower 32 is formed to be approximately the same length as the door pocket upper 31 in the vehicle width direction, and its inner side in the vehicle width direction is attached and fixed to the side surface of the side member 11 together with the door pocket upper 31. This configuration can be seen in FIGS. 7 and 8 . The door pocket lower 32 has a lower support portion 32B that extends downward from the outer side in the vehicle width direction and is fixed to the side sill 28. This configuration can be seen in FIG.

[0021] The chassis frame 10 includes a pair of left and right side members 11 extending in the vehicle longitudinal direction, and multiple cross members 12, 13, 14 extending in the vehicle width direction and connecting the pair of left and right side members 11. The multiple cross members 12, 13, 14 include a front cross member 12 that spans the front portions of the pair of side members 11, a rear cross member 13 that spans the rear portions of the pair of side members 11, and an intermediate cross member 14 that spans the pair of side members 11 and is located near a center pillar 23 (the front end of the door pocket 30) in the longitudinal direction. This configuration can be seen in Figure 2. Note that multiple cross members 12, 13, 14 may be arranged side by side in the longitudinal direction.

[0022] The side members 11 are disposed along the vehicle widthwise inner side of the door pocket 30 (and the side sill 28) extending in the front-rear direction. This configuration can be seen in FIGS. 2 to 4 . More specifically, as shown in FIG. 9 and other figures, there is a gap between the vehicle widthwise outer surface of the side member 11 and the vehicle widthwise inner surface of the door pocket 30 (door pocket lower 32). Meanwhile, as shown in FIGS. 7 and 8 , the vehicle widthwise outer surface of the side member 11 is in close proximity to or in contact with the door pocket lower projection 32A, which is the front end of the door pocket 30. The side members 11 are disposed so that at least the lower ends of the side members 11 overlap the door pocket 30 in the vertical direction. More specifically, the side members 11 are disposed so that they overlap the lower rails 33 disposed in the door pocket 30 and the sliding door arms 24A that slide along the lower rails 33 in the vertical direction. This configuration can be seen in FIG. 8 .

[0023] Support brackets 15 are fixed at predetermined intervals to the underside of the side members 11 to attach the driving battery 2 to the chassis frame 10. In this embodiment, five support brackets 15 are provided at predetermined intervals in the center of the front-to-rear direction of each side member 11. The number and spacing of the support brackets 15 are set appropriately depending on the shape and length of the driving battery 2.

[0024] The intermediate cross member 14 has a pair of intermediate cross end portions 14A fixed to the vehicle widthwise inner surfaces of the side members 11 by welding or the like, and an intermediate cross central portion 14B connecting the pair of intermediate cross end portions 14A. The bottom surfaces of the intermediate cross end portions 14A slope upward from the vehicle widthwise ends toward the vehicle widthwise central portion. As a result, the lower ends of the intermediate cross end portions 14A are positioned to overlap the door pocket 30 in the vertical direction. This configuration can be seen in Figure 9 and other figures. The intermediate cross central portion 14B has a uniform thickness in the vertical direction. As a result, both ends of the intermediate cross member 14 are firmly connected to the side members 11 while ensuring as much space as possible for arranging the driving battery 2.

[0025] The intermediate cross member 14 is positioned in the front-to-rear direction so that the intermediate cross member 14 overlaps at least a portion of the door pocket lower projection 32A at the front end of the door pocket 30 in a side view. In other words, the intermediate cross member 14 and the door pocket lower projection 32A are arranged side by side in the vehicle width direction so as to overlap in a side view. This configuration can be seen in Figures 4 and 8. The intermediate cross member 14 overlaps at least a portion of the door pocket 30 in the up-down direction. In this embodiment, the lower portion of the intermediate cross member end 14A, which is formed to be wide in the up-down direction, overlaps with the upper portion of the door pocket 30 in the up-down direction.

[0026] The driving battery 2 is located below the floor panel 25 of the cabin 20, between a pair of side members 11. This configuration can be seen in Figure 2. The driving battery 2 is configured as a battery pack, with multiple batteries housed in a container and an inverter and other electrical equipment installed. In this embodiment, this battery pack is referred to as the driving battery 2.

[0027] The driving battery 2 is attached and fixed to support brackets 15 attached to the undersides of the side members 11 via mounting brackets 3 attached to the sides of the battery pack. This allows the driving battery 2 to be attached and fixed so that it spans between the pair of left and right side members 11. This configuration can be seen in Figure 2.

[0028] 7 to 9, the driving battery 2 is disposed between a pair of side members 11 arranged side by side in the left-right direction, and is disposed in a position where at least a portion of the driving battery 2 overlaps vertically with the door pocket 30. In this embodiment, the driving battery 2 is disposed so that the upper surface of the battery pack is higher than the lower end of the side members 11, and is disposed below the floor panel 25 in a space-efficient manner.

[0029] The side sills 28 are skeletal members disposed at the lower end of the side surfaces of the cabin 20 and extending in the front-to-rear direction. The side sills 28 are disposed below the pair of side members 11 and outboard in the vehicle width direction. Each side sill 28 has an inner sill 28A constituting the left and right inner sides and an outer sill 28B constituting the left and right outer sides. The side sills 28 are disposed immediately below the door pockets 30, to which the door pockets 30 are attached. Specifically, the lower support portion 32B of the door pockets 30 is fixed so as to be sandwiched between the inner sill 28A and the outer sill 28B. This configuration can be seen in FIG. 8 .

[0030] The side sill 28 extends in the front-to-rear direction from near the front end of the front door opening 21 to near the rear end of the rear door opening 22. The door pocket 30 is provided on the top surface of the side sill 28 from the midpoint in the front-to-rear direction to the rear. The front end of the side sill 28 is provided with a reinforcing portion 29 whose cross-sectional shape is enlarged in the vertical direction. This further improves the strength of the front portion of the side sill 28.

[0031] (Effects) With the above vehicle undercarriage structure, the door pocket 30 is disposed on the left and right outer sides of the side members 11, which are disposed on both the left and right sides of the driving battery 2. Therefore, when a collision load is applied from the side of the vehicle, the entire door pocket 30 comes into contact with the outer side of the side member 11 on the inner side in the vehicle direction. This prevents the door pocket 30 from coming into contact with the driving battery 2.

[0032] As shown in FIG. 9 , the door pocket lower projection 32A at the front end of the door pocket 30, the side member 11, and the intermediate cross member 14 are aligned in the vehicle width direction so as to overlap in a side view, and the lower end of the side member 11 overlaps the door pocket 30 in the vertical direction. This allows the collision load transmitted from the door pocket lower projection 32A to the side member 11 to be smoothly transmitted to the intermediate cross member 14. This allows the intermediate cross member 14 to function as a tension rod, preventing the door pocket lower projection 32A from moving inward toward the side member 11 when a collision load is input from the side of the vehicle, or preventing the lower portion of the side member 11, to which the collision load is transmitted, from being pushed inward toward the vehicle width direction and collapsing. In other words, this more reliably prevents the door pocket lower projection 32A and the side member 11 from coming into contact with the driving battery 2 when a collision load is applied from the side of the vehicle. Furthermore, by installing the driving battery 2 across the pair of side members 11, the pair of side members 11 are less likely to collapse inward toward the vehicle width direction.

[0033] Furthermore, because the lower end of the intermediate cross end portion 14A is configured to be lower than the center position of the side member 11 in the up-down direction, the collision load transmitted from the door pocket lower projection 32A to the side member 11 can be transmitted smoothly and reliably to the intermediate cross member 14. This more reliably prevents the side member 11 from collapsing inward in the vehicle width direction due to the collision load. This configuration can be seen in FIG. 9.

[0034] The door pocket 30 is firmly fixed to the side sill 28 via the lower support portion 32B. The door pocket 30 is provided above and along the side sill 28, positioned slightly offset inward in the vehicle width direction. In other words, the outer sill 28B of the side sill 28 protrudes outward in the vehicle width direction beyond the door pocket 30. With this configuration, in this embodiment, a collision load from the side of the vehicle can be borne by the side sill 28, which is a strong framework member. Therefore, the collision load input to the side sill 28 can be distributed to the frame members that constitute the cabin 20. In other words, it is possible to more efficiently prevent the door pocket 30 and the side member 11 from interfering with the drive battery 2 located inward in the vehicle width direction.

[0035] The present invention is not limited to the above-described embodiment, and modifications and improvements can be made as appropriate.

[0036] As described above, this specification discloses the following: (1) A vehicle undercarriage comprising: a door pocket having a guide rail therein for guiding a sliding door; a pair of side members disposed on the inside of the door pocket in the vehicle width direction, extending in the fore-and-aft direction of the vehicle and arranged side by side in the vehicle width direction; a cross member extending in the vehicle width direction and connecting the pair of side members; and on-board equipment disposed between the pair of side members and overlapping the door pocket in the vertical direction, wherein the door pocket, the side members, and the cross member are arranged side by side in the vehicle width direction so as to overlap in a side view. With this configuration, in the event of a collision with the side of the vehicle, the collision load transmitted to the door pocket can be absorbed by the pair of side members arranged side by side in the vehicle width direction of the door pocket and the cross member connecting the pair of side members. This prevents the pair of side members from falling inward in the vehicle width direction due to the door pocket to which the collision load is transmitted and contacting the on-board equipment.

[0037] (2) The vehicle undercarriage structure according to (1), wherein a lower end of the side member is disposed so as to overlap with the door pocket portion in the vertical direction. With this configuration, the side member can efficiently receive a collision load from the door pocket portion and can prevent the door pocket portion from intruding into an on-vehicle device.

[0038] (3) The vehicle undercarriage structure according to (1) or (2), wherein the lower ends of the cross members in the vehicle width direction are positioned lower than the centers of the side members in the up-down direction. With this configuration, the cross members can support the side members, so that the side members can be more reliably prevented from collapsing inward in the vehicle width direction due to a collision load transmitted from the door pocket.

[0039] (4) The vehicle undercarriage structure according to any one of (1) to (3), wherein the cross member has cross end portions whose bottom surfaces slope upward from the vehicle width direction end portions toward the vehicle width direction center portion, and a cross central portion whose width in the up-down direction is approximately uniform. With this configuration, the cross member can be firmly fixed to the side members, while making it possible to maximize the space between the pair of side members where on-vehicle equipment is arranged.

[0040] (5) The vehicle understructure according to any one of (1) to (4), wherein the pair of side members are provided with mounting brackets to which the on-board equipment is attached, and the on-board equipment is attached so as to bridge the space between the pair of side members via the mounting brackets. With this configuration, the on-board equipment itself also acts as a member that reinforces the space between the pair of side members, making the side members less susceptible to deformation.

[0041] (6) The vehicle undercarriage structure according to any one of (1) to (5), wherein the door pocket portion is disposed along an upper surface side of a side sill extending along the vehicle longitudinal direction, the door pocket portion is fixed to the side sill, and the side sill protrudes outward in the vehicle width direction beyond the door pocket portion. With this configuration, the side sill can withstand a collision load from the side of the vehicle, and the collision load can also be distributed to frame members constituting the cabin.

[0042] (7) The vehicle underbody structure according to any one of (1) to (6), wherein the on-board device is a battery. This configuration ensures a large space for arranging the battery and protects the battery from a collision load from the side of the vehicle.

[0043] DESCRIPTION OF SYMBOLS 2 Drive battery (battery, on-board equipment) 3 Mounting bracket 10 Chassis frame 11 Side member 12 Front cross member (cross member) 13 Rear cross member (cross member) 14 Intermediate cross member (cross member) 14A Intermediate cross end (cross end) 14B Intermediate cross center (cross center) 15 Support bracket 20 Cabin 21 Front door opening 22 Rear door opening 23 Center pillar 24 Sliding door 24A Sliding door arm 24B Horizontal roller 25 Floor panel 26 Upper rail 27 Intermediate rail 28 Side sill 28A Inner sill 28B Outer sill 29 Reinforcement part 30 Door pocket (door pocket part) 31 Door pocket upper 32 Door pocket lower 32A Door pocket lower protrusion 32B Lower support part 33 Lower rail 100 Vehicle

Claims

1. A vehicle undercarriage structure comprising: a door pocket section having a guide rail for guiding a sliding door inside; a pair of side members arranged inside the door pocket section in the vehicle width direction, extending in the fore-and-aft direction of the vehicle and arranged side by side in the vehicle width direction; a cross member extending in the vehicle width direction and connecting the pair of side members; and on-board equipment arranged between the pair of side members and overlapping the door pocket section in the vertical direction, wherein the door pocket section, the side members, and the cross members are arranged side by side in the vehicle width direction so as to overlap in a side view.

2. The vehicle undercarriage structure according to claim 1, wherein the lower ends of the side members are positioned so as to overlap the door pocket portion in the vertical direction.

3. A vehicle underbody structure according to claim 1 or 2, wherein the lower ends of the vehicle width direction ends of the cross members are positioned lower than the vertical centers of the side members.

4. A vehicle undercarriage structure as set forth in any one of claims 1 to 3, wherein the cross member has cross end portions whose bottom surfaces slope upward from the vehicle width direction end portions to the vehicle width direction center portion, and a cross center portion whose width in the up-down direction is approximately uniform.

5. A vehicle undercarriage structure according to any one of claims 1 to 4, wherein the pair of side members are provided with mounting brackets to which the on-board equipment is attached, and the on-board equipment is attached so as to bridge between the pair of side members via the mounting brackets.

6. A vehicle undercarriage structure as claimed in any one of claims 1 to 5, wherein the door pocket section is disposed along the upper surface of a side sill extending in the longitudinal direction of the vehicle, the door pocket section is fixed to the side sill, and the side sill protrudes outward in the vehicle width direction beyond the door pocket section.

7. The vehicle underbody structure according to any one of claims 1 to 6, wherein the on-board device is a battery.

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