Vehicle undercarriage

Abstract

To obtain a vehicle understructure that can improve the rust prevention performance around the main body of the battery case. [Solution] The main body 22 of the battery case 20 houses the batteries, and a flange portion 24 protrudes from the outer circumference of the main body 22 of the battery case 20. Furthermore, the portion that constitutes the upper surface 20A of the battery case 20 also serves as the vehicle's floor panel. The flange portion 24 of the battery case 20 is connected to the frame portion 10 of the lower part of the vehicle. A cover member 70 is fixed to the main body 22 of the battery case 20, and the covering portion 72 of the cover member 70 is positioned on the vehicle's upper side relative to the flange portion 24 between the main body 22 of the battery case 20 and the frame portion 10.

Description

Technical Field

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[0001] The present invention relates to a vehicle underbody structure.

Background Art

[0002] A configuration in which a battery case is disposed under a vehicle is known (see, for example, Patent Document 1 and Patent Document 2). Patent Document 1 below discloses a technique related to a vehicle underbody structure in which a battery case functions as a vehicle body floor. Briefly described, in this prior art, the battery case is connected to a skeleton portion under the vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a structure in which a battery case functioning as a vehicle body floor is connected to a skeleton portion under the vehicle, a flange portion extending from the main body portion of the battery case may be coupled to the skeleton portion.

[0005] However, in such a structure, there is a risk of rust due to water droplets or the like accumulating on the flange portion around the main body portion of the battery case, and there is room for improvement in this regard.

[0006] In consideration of the above facts, an object of the present invention is to obtain a vehicle underbody structure capable of improving the rust prevention performance around the main body portion of the battery case.

Means for Solving the Problems

[0007] The vehicle understructure according to the first embodiment comprises a battery case having a main body portion for housing a battery and a flange portion protruding from the outer circumference of the main body portion, the portion of which forming the upper surface also serves as the vehicle's floor panel, a vehicle underframe portion to which the flange portion of the battery case is connected, and a cover member fixed to the main body portion of the battery case and having a covering portion positioned above the flange portion between the main body portion and the frame portion of the battery case.

[0008] According to the first embodiment of the vehicle understructure, the main body of the battery case houses the battery, a flange protrudes from the outer circumference of the main body of the battery case, and the upper part of the battery case also serves as the vehicle's floor panel. The flange of the battery case is connected to the frame of the underside of the vehicle. A cover member is fixed to the main body of the battery case, and the covering portion of the cover member is positioned above the flange portion between the main body of the battery case and the frame. As a result, the covering portion of the cover member prevents water droplets from accumulating on the flange portion around the main body of the battery case, thereby preventing rust from forming around the main body of the battery case.

[0009] The vehicle understructure according to the second embodiment has the configuration described in the first embodiment above, wherein the covering portion has a groove that extends in a direction perpendicular to the protruding direction of the flange portion directly below the covering portion when viewed from above the vehicle.

[0010] According to the vehicle understructure of the second embodiment, the cover portion has a groove portion that extends in a direction perpendicular to the protruding direction of the flange portion directly below the cover portion in a plan view of the vehicle, so that water that would otherwise flow from the outer circumference of the battery case body portion towards the frame portion can be collected in the groove portion. As a result, even if the floor portion of the vehicle is wet with a large amount of water, it is possible to suppress the occurrence of rust around the main body portion of the battery case.

[0011] The vehicle understructure according to the third embodiment has the configuration described in the second embodiment above, wherein the groove has a water slope that is inclined downward toward the vehicle toward at least one end in the direction in which the groove extends.

[0012] According to the vehicle understructure of the third embodiment, the groove has a water gradient that slopes downward toward the vehicle toward at least one end in the direction in which the groove extends, so that water that enters the groove can be drained in a predetermined direction by the water gradient.

[0013] The vehicle understructure according to the fourth embodiment is configured as described in the third embodiment, wherein the frame portion has a pair of rockers provided on both sides in the vehicle width direction of the underside of the vehicle and extending along the vehicle longitudinal direction, the flange portion of the battery case is connected to the pair of rockers, and the cover member is provided on the end side of the battery case in the vehicle width direction and has the covering portion disposed between the main body portion of the battery case and the rocker, the covering portion has the groove portion extending along the vehicle longitudinal direction.

[0014] According to the fourth embodiment of the vehicle understructure, the flange portion of the battery case is connected to a pair of rockers. The cover member is provided on the end side of the battery case in the vehicle width direction and has a covering portion that is positioned between the main body portion of the battery case and the rockers, and the covering portion has a groove portion that extends along the longitudinal direction of the vehicle. By providing the groove portion along the longitudinal direction of the vehicle in this way, it is possible to secure a sufficient capacity that can be stored in the groove portion.

[0015] The vehicle understructure according to the fifth embodiment is configured in the configuration described in the fourth embodiment, wherein the frame has a cross member spanning between the pair of rockers, the flange portion of the battery case is connected to the cross member, the battery case has an upper case constituting the upper part of the battery case and a lower case constituting the lower part of the battery case, the flange portion is formed by joining the upper flange portion of the upper case and the lower flange portion of the lower case, and the upper flange portion and the lower flange A first sealing portion is provided to seal the gap between the flange portion and the cross member, and a second sealing portion is provided to seal the gap between the portion of the flange portion of the battery case that is closer to the tip in the direction of extension than the first sealing portion and the cross member, and the upper flange portion of the upper case has a stepped portion between the first sealing portion and the second sealing portion, and the portion closer to the tip of the stepped portion is set lower in the vehicle vertical direction than the portion closer to the base of the stepped portion, and the groove portion has a water gradient so that the water it receives is directed toward the stepped portion.

[0016] According to the fifth embodiment of the vehicle understructure, the flange portion of the battery case is connected to the cross member. The first seal portion seals the space between the upper flange portion and the lower flange portion, while the second seal portion seals the space between the cross member and the portion of the flange portion of the battery case that is further forward in the direction of the protrusion of the first seal portion. Furthermore, the upper flange portion of the upper case has a stepped portion between the first seal portion and the second seal portion, and the portion on the tip side of the stepped portion is set lower in the vehicle vertical direction compared to the portion on the base side of the stepped portion. Here, the groove portion has a water gradient so that the water it receives flows toward the stepped portion, so that water that flows into the groove portion on the vehicle width side of the battery case can flow toward the stepped portion, and water that falls onto the upper flange portion can be prevented from flowing toward the main body portion. [Effects of the Invention]

[0017] As described above, the vehicle understructure according to the present invention has the excellent effect of improving the rust prevention performance around the main body of the battery case.

Brief Description of the Drawings

[0018] [Figure 1] It is a plan view showing a simplified vehicle underbody structure according to an embodiment. [Figure 2] It is a cross-sectional view showing a simplified state cut along the line 2-2 of FIG. 1. [Figure 3] It is a cross-sectional view showing a simplified state cut along the line 3-3 of FIG. 1. [Figure 4] It is a perspective view showing a simplified front-end side portion of the cover member.

Modes for Carrying Out the Invention

[0019] Hereinafter, the vehicle underbody structure according to an embodiment will be described with reference to FIGS. 1 to 4. The arrows FR, UP, and LH appropriately shown in each figure indicate the front direction (travel direction), the upward direction, and the left side of the vehicle, respectively. Hereinafter, when simply using the front-rear, up-down, and left-right directions for description, unless otherwise specified, it shall indicate the front-rear in the vehicle front-rear direction, the up-down in the vehicle up-down direction, and the left-right in the vehicle left-right direction. Also, in each figure, some reference numerals may be omitted for the sake of clarity of the drawing.

[0020] (Configuration of the Embodiment) FIG. 1 shows a simplified plan view of the underbody structure of an electric vehicle. As shown in FIG. 1, the skeleton portion 10 of the underbody includes a pair of rockers 12 provided on both sides in the vehicle width direction of the underbody and extending along the vehicle front-rear direction, and a pair of cross members 14, 16 spanned between the pair of rockers 12 and spaced apart from each other in the vehicle front-rear direction. In FIG. 1, for the sake of convenience, the illustration of the intermediate portion in the vehicle front-rear direction such as the skeleton portion 10 is omitted. Also, in the figure, the cross member (front cross member) arranged on the front side of the pair of cross members 14, 16 is denoted by reference numeral 14, and the cross member (rear cross member) arranged on the rear side of the pair of cross members 14, 16 is denoted by reference numeral 16. The front cross member 14 connects the front end portions of the left and right rockers 12 in the vehicle width direction, and the rear cross member 16 connects the rear end portions of the left and right rockers 12 in the vehicle width direction.

[0021] Between the pair of cross members 14, 16 and between the pair of rockers 12, the main body portion 22 of the battery case 20 is arranged. The battery case 20 has a portion on the upper surface 20A side that also serves as the floor panel of the vehicle, and the main body portion 22 of the battery case 20 is formed in a flat box shape in the vehicle up-down direction with the vehicle front-rear direction as the longitudinal direction.

[0022] FIG. 2 shows a simplified cross-sectional view of the state cut along the line 2-2 of FIG. 1. As shown in FIG. 2, the main body portion 22 of the battery case 20 houses the battery 50. The battery 50 is a secondary battery. FIG. 3 shows a simplified cross-sectional view of the state cut along the line 3-3 of FIG. 1. As shown in FIGS. 1 to 3, the battery case 20 has a flange portion 24 that projects from the outer peripheral side of the main body portion 22.

[0023] As shown in Figure 1, the flange portion 24 is formed around the entire circumference of the battery case 20, for example. For convenience, in the following description, the portion of the flange portion 24 that constitutes the front end of the battery case 20 may be referred to as the front flange portion 24F, the portion of the flange portion 24 that constitutes the rear end of the battery case 20 may be referred to as the rear flange portion 24R, and the portion of the flange portion 24 that constitutes the end of the battery case 20 in the vehicle width direction may be referred to as the side flange portion 24S.

[0024] As shown in Figures 2 and 3, the battery case 20 has an upper case 30 that constitutes the upper part of the battery case 20 and a lower case 40 that constitutes the lower part of the battery case 20. The upper case 30 is the part that constitutes the upper surface 20A side of the battery case 20 and comprises a box-shaped upper case body 32 that is arranged so as to be open on the lower side of the vehicle and an upper flange 34 that protrudes from the open end of the upper case body 32. The upper case body 32 has a top plate 32A that is substantially rectangular in plan view and an upper peripheral wall 32B that is formed continuously with the peripheral end of the top plate 32A. The lower case 40 has a box-shaped lower case body 42 that is arranged so as to be open on the upper side of the vehicle and a lower flange 44 that protrudes from the open end of the lower case body 42. The lower case body portion 42 comprises a bottom plate portion 42A that is substantially rectangular in plan view, and a lower peripheral wall portion 42B that is formed continuously with the peripheral end of the bottom plate portion 42A.

[0025] The upper flange portion 34 of the upper case 30 and the lower flange portion 44 of the lower case 40 are joined together to form the flange portion 24 of the battery case 20. In addition, the upper case body portion 32 of the upper case 30 and the lower case body portion 42 of the lower case 40 constitute the main body portion 22 of the battery case 20.

[0026] The flange portion 24 of the battery case 20 is connected to a pair of rockers 12 and a pair of cross members 14 and 16 that constitute the frame 10 of the lower part of the vehicle shown in Figure 1. The side flange portion 24S of the battery case 20 shown in Figure 2 is fixed to the rocker 12 by bolt fastening (indicated by a dashed-dotted line 60 in the figure) at a position offset in the longitudinal direction of the vehicle relative to the cross section of Figure 2. The front flange portion 24F of the battery case 20 shown in Figure 3 is connected to the front cross member 14 by bolt fastening (indicated by a dashed-dotted line 62 in the figure) at a position offset in the width direction of the vehicle relative to the cross section of Figure 3. The rear flange portion 24R of the battery case 20 shown in Figure 1 is connected to the rear cross member 16 by bolt fastening (fasteners are not shown). The connection structure between the battery case 20 and the rear cross member 16 is, for example, substantially the same as the connection structure between the battery case 20 and the front cross member 14.

[0027] On the other hand, a cover member 70 is provided on the vehicle width side of the battery case 20, extending along the vehicle's longitudinal direction. The cover member 70 is provided in a pair, left and right, and is fixed to the main body 22 of the battery case 20. The cover member 70 is made of resin or metal (for example, steel) and consists of a long plate material. The pair of left and right cover members 70 are formed symmetrically, as an example. Figure 4 shows a simplified perspective view of the front end portion of the cover member 70 attached to the left side of the battery case 20. In Figure 4, the direction of the cover member 70 when it is fixed to the battery case 20 (see Figure 2) is indicated by arrows FR, UP, and LH.

[0028] As shown in Figure 4, the cover member 70 is formed in a bent plate shape. Specifically, the cover member 70 comprises a flat upper plate portion 70A, a hanging portion 70B bent downward from the outer end of the upper plate portion 70A in the vehicle width direction, a bottom plate portion 70C bent outward in the vehicle width direction from the lower end of the hanging portion 70B, and an upright portion 70D bent upward from the outer end of the bottom plate portion 70C in the vehicle width direction.

[0029] As shown in Figure 2, the cover member 70 is positioned such that the corner portion 70K, which is the boundary between the upper plate portion 70A and the hanging portion 70B, is located on the outer surface side of the corner portion 32K, which is the boundary between the top plate portion 32A and the upper peripheral wall portion 32B of the upper case 30. The upper plate portion 70A of the cover member 70 is fixed to the outer portion of the top plate portion 32A of the upper case 30 in the vehicle width direction by welding or the like, in a state where it is overlapped from the vehicle's upper side.

[0030] Furthermore, the cover member 70 has a covering portion 72 positioned on the vehicle-upward side relative to the flange portion 24 (side flange portion 24S) between the main body portion 22 of the battery case 20 and the rocker 12 of the frame portion 10. Also, as shown in Figure 1, the covering portion 72 has a groove portion 74 that extends in a direction perpendicular to the protruding direction of the flange portion 24 (side flange portion 24S) directly below the covering portion 72 in a plan view of the vehicle. That is, the groove portion 74 extends in the longitudinal direction of the vehicle. The groove portion 74 is an element that can be grasped as a water receiving portion.

[0031] Furthermore, in this embodiment, as shown in Figure 3, a first seal portion 80 is provided to seal the space between the upper flange portion 34 and the lower flange portion 44. The first seal portion 80 is located on the side of the main body portion 22 that is closer to the center position between the base end and the tip end of the flange portion 24 of the battery case 20. In addition, a second seal portion 82 is provided between the flange portion 24 of the battery case 20 and the front cross member 14, sealing the space between the portion of the flange portion 24 of the battery case 20 that is closer to the tip end in the direction of extension of the first seal portion 80 and the front cross member 14. Moreover, the upper flange portion 34 of the upper case 30 has a stepped portion 34B between the first seal portion 80 and the second seal portion 82, and the portion 34C closer to the tip end than the stepped portion 34B is set lower in the vehicle's vertical direction compared to the portion 34A closer to the base end than the stepped portion 34B.

[0032] Although not shown in the illustration, the configuration of the part of the battery case 20 including the rear flange portion 24R and the rear cross member 16 shown in Figure 1 is substantially the same as the configuration of the part of the battery case 20 including the front flange portion 24F and the front cross member 14 shown in Figure 3, but with the front and rear reversed.

[0033] As shown in Figure 4, the groove 74 has a water gradient that slopes downward toward the vehicle towards one end in the direction in which the groove 74 extends (in this embodiment, for example, the front end 74A side (the front end in the vehicle's longitudinal direction)), and the water gradient is such that the water that enters it flows toward the stepped portion 34B (see Figures 1 and 3). In Figure 4, the dashed arrow fw conceptually shows the direction in which liquid such as water would flow if it entered the groove 74.

[0034] (Effects and mechanisms of the embodiment) Next, the operation and effects of the above embodiment will be described.

[0035] In this embodiment, the main body 22 of the battery case 20 shown in Figure 1 houses the battery 50 (see Figure 2), a flange portion 24 protrudes from the outer circumference of the main body 22 of the battery case 20, and the portion that constitutes the upper surface 20A of the battery case 20 also serves as the vehicle's floor panel. The flange portion 24 of the battery case 20 is connected to the frame portion 10 of the lower part of the vehicle. Here, a cover member 70 is fixed to the main body 22 of the battery case 20, and the covering portion 72 of the cover member 70 is positioned above the flange portion 24 between the main body 22 of the battery case 20 and the frame portion 10. Therefore, the covering portion 72 of the cover member 70 can prevent water droplets and the like from accumulating on the flange portion 24 around the main body 22 of the battery case 20, and can suppress the occurrence of rust around the main body 22 of the battery case 20.

[0036] Furthermore, in this embodiment, the cover portion 72 has a groove portion 74 that extends in a direction perpendicular to the protruding direction of the flange portion 24 directly below the cover portion 72 in a plan view of the vehicle. As a result, as shown in Figure 2, water 100 that would otherwise flow from the outer circumference of the main body portion 22 of the battery case 20 towards the frame portion 10 can be collected in the groove portion 74. This makes it possible to suppress the occurrence of rust around the main body portion 22 of the battery case 20 even if the floor portion of the vehicle gets wet with a large amount of water.

[0037] Furthermore, in this embodiment, as shown in Figure 4, the groove 74 has a water gradient that slopes downward toward the vehicle toward one end (front end 74A) in the direction in which the groove 74 extends. Therefore, the water gradient makes it possible to drain the water that enters the groove 74 in a predetermined direction (see arrow fw).

[0038] Furthermore, in this embodiment, as shown in Figure 1, the side flange portion 24S of the flange portion 24 of the battery case 20 is connected to a pair of rockers 12 that constitute part of the frame portion 10. The cover member 70 is provided on the end side of the battery case 20 in the vehicle width direction, and the covering portion 72 of the cover member 70 is positioned between the main body portion 22 of the battery case 20 and the rockers 12, and the groove portion 74 of the covering portion 72 extends along the longitudinal direction of the vehicle. By providing the groove portion 74 along the longitudinal direction of the vehicle in this way, it is possible to secure a sufficient capacity that can be stored in the groove portion 74.

[0039] Furthermore, in this embodiment, as shown in Figure 3, the space between the upper flange portion 34 and the lower flange portion 44 of the battery case 20 is sealed by the first seal portion 80. In addition, the space between the front flange portion 24F of the battery case 20 that is closer to the tip in the direction of extension from the first seal portion 80 and the front cross member 14 is sealed by the second seal portion 82. Moreover, the upper flange portion 34 of the upper case 30 has a stepped portion 34B between the first seal portion 80 and the second seal portion 82, and the portion 34C closer to the tip of the stepped portion 34B is set lower in the vehicle's vertical direction compared to the portion 34A closer to the base of the stepped portion 34B. Here, the groove portion 74 shown in Figure 4 has a water gradient so that the water it receives flows toward the stepped portion 34B (see Figures 1 and 3). Therefore, water that flows into the groove 74 on the side of the battery case 20 in the vehicle width direction shown in Figure 1 can be guided and flowed toward the stepped portion 34B shown in Figure 3, and water 100 that falls onto the upper flange portion 34 can be prevented from flowing toward the main body portion 22 of the battery case 20.

[0040] As described above, the vehicle understructure according to this embodiment makes it possible to improve the rust prevention performance around the main body portion 22 of the battery case 20.

[0041] (Supplementary explanation of the embodiment) In the embodiments shown in Figures 1 to 4, the groove 74 has a water slope that inclines downward toward the vehicle toward the front end 74A, which is one end in the direction in which the groove 74 extends. However, as a modification of the above embodiments, for example, a groove provided in the same position as the groove 74 in the above embodiments when viewed from above may have a water slope that inclines downward toward the vehicle toward the rear end, which is one end in the direction in which the groove extends, or it may have two water slopes that incline downward toward the vehicle toward the front end and rear end in the direction in which the groove extends.

[0042] Furthermore, as another modification of the above embodiment, for example, a configuration can be adopted in which a groove provided in the same position as the groove 74 of the above embodiment in a plan view of the vehicle does not have a water slope that is inclined downward toward the vehicle toward one end in the direction in which the groove extends.

[0043] Furthermore, in the above embodiment, the cover portion 72 has a groove portion 74 that extends in a direction perpendicular to the protruding direction of the flange portion 24 (side flange portion 24S) directly below the cover portion 72 in a plan view of the vehicle, and such a configuration is preferred. However, as a modification of the above embodiment, a configuration can also be adopted in which the cover portion does not have a groove portion that extends in a direction perpendicular to the protruding direction of the flange portion (24) directly below the cover portion in a plan view of the vehicle.

[0044] Furthermore, as a modification of the above embodiment, a water-absorbing material may be provided on the outer surface side of the stepped portion (34B) in the upper flange portion (34) of the upper case (30).

[0045] Furthermore, in the above embodiment, the battery case 20 is configured to include an upper case 30 having a box-shaped upper case body 32 that is arranged so as to be open on the lower side of the vehicle. However, as a modification of the above embodiment, the battery case may also be configured to have an upper member that does not have a box-shaped portion and is used in conjunction with the floor panel instead of the upper case 30 of the above embodiment, and a lower case that has a depth capable of housing the entire battery inside instead of the lower case 40 of the above embodiment.

[0046] Furthermore, in the above embodiment, a cover member extending along the vehicle width direction is not provided on the vehicle front-rear end of the battery case 20, but a cover member extending along the vehicle width direction may be provided on the vehicle front-rear end of the battery case 20. That is, the vehicle understructure may include a configuration in which a cover member is fixed to the vehicle front-rear end of the main body portion (22) of the battery case (20), and the cover member extends along the vehicle width direction and has a covering portion positioned on the vehicle upper side relative to the flange portion (24) of the battery case (20) between the main body portion (22) of the battery case (20) and the cross members (14, 16). In such a configuration, the covering portion may have a groove portion extending along a direction perpendicular to the protruding direction of the flange portion (24) directly below the covering portion in a plan view of the vehicle (i.e., the vehicle width direction).

[0047] Furthermore, the above embodiments and the various modifications described above can be combined as appropriate.

[0048] Although an example of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement it in various ways without departing from its spirit. [Explanation of Symbols]

[0049] 10 Skeletal parts 12 Rocka 14 Cross Member 16 Crossmember 20 Battery Cases 20A top 22 Main body 24 Flange section 30 Upper Case 34 Upper flange section 34A The portion closer to the base end than the stepped portion 34B Stepped section 34C The part closer to the tip than the stepped section 40 Lower Cases 44 Lower flange section 50 batteries 70 Cover component 72 Covering part 74 Groove 74A Front end (one end in the direction in which the groove extends) 80 First seal section 82 Second seal section

Claims

1. A battery case having a main body for housing a battery and a flange portion protruding from the outer circumference of the main body, the portion of which constitutes the upper surface also serves as the floor panel of the vehicle, The flange portion of the battery case is connected to the lower frame portion of the vehicle, A cover member having a covering portion fixed to the main body portion of the battery case and positioned between the main body portion and the frame portion of the battery case on the vehicle-upward side relative to the flange portion, A vehicle understructure equipped with the following features.

2. The vehicle understructure according to claim 1, wherein the covering portion has a groove that extends in a direction perpendicular to the protruding direction of the flange portion directly below the covering portion when viewed from above the vehicle.

3. The vehicle understructure according to claim 2, wherein the groove has a water slope that is inclined downward toward the vehicle toward at least one end in the direction in which the groove extends.

4. The frame portion has a pair of rockers provided on both sides in the vehicle width direction of the lower part of the vehicle and extending along the vehicle longitudinal direction. The flange portion of the battery case is connected to the pair of rockers. The vehicle understructure according to claim 3, wherein the cover member is provided on the end side of the battery case in the vehicle width direction and has the covering portion disposed between the main body portion of the battery case and the rocker, and the covering portion has the groove portion extending along the vehicle longitudinal direction.

5. The frame has a cross member spanning between the pair of rockers, The flange portion of the battery case is connected to the cross member. The battery case comprises an upper case that constitutes the upper part of the battery case and a lower case that constitutes the lower part of the battery case, and the flange portion is formed by joining the upper flange portion of the upper case and the lower flange portion of the lower case. A first sealing portion is provided to seal the space between the upper flange portion and the lower flange portion, and a second sealing portion is provided to seal the space between the portion of the flange portion of the battery case that is closer to the tip in the direction of extension than the first sealing portion and the cross member. The upper flange portion of the upper case has a stepped portion between the first seal portion and the second seal portion, and the portion closer to the tip of the stepped portion is set lower in the vehicle's vertical direction compared to the portion closer to the base of the stepped portion. The vehicle understructure according to claim 4, wherein the groove has a water gradient such that the received water flows toward the stepped portion.

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