Frame structure of a vehicle

Abstract

To provide a frame structure of a vehicle capable of avoiding making a constitution complicated and highly heavy and inhibiting deformation and breakage of upper and lower kick parts due to a front collision.SOLUTION: A frame structure 1 of a vehicle includes a pair of left and right side rails 2 extending in a vehicular fore-and-aft direction. The side rail 2 includes a front side rail 11 that is located on a forward side in the vehicle and supports a front wheel 6 and cab 7, a rear side rail 12 that is located behind the front side rail 11 and supports a rear wheel and cargo bed 8, and upper and lower kick parts 13 that connect the rear side rail 12 to the front side rail 11 in such a manner that the rear side rail lies a step lower than the front side rail. A front part 11a of the front side rail 11 has a notch 30 in a width direction of the vehicle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a frame structure of a vehicle.

Background Art

[0002] As a technology related to a frame structure of a vehicle that runs by power supplied from a battery, for example, there is a frame structure described in Patent Document 1. This conventional frame structure includes a ladder frame in which a pair of side rails are provided so as to face each other in the vehicle width direction, and a power supply unit disposed between the pair of side rails and connected to each of the pair of side rails. Each of the pair of side rails is provided with flanges of a predetermined width at both ends of the web. The flange is provided with a constricted portion at a position corresponding to at least one corner of the power supply unit in the vehicle width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional frame structure, the side rails are substantially linear. For this reason, at the time of a frontal collision of the vehicle, an input in the axial compression direction is applied to the side rails, and the structure is advantageous for deformation. On the other hand, in recent years, from the viewpoint of securing the loading capacity of the vehicle, etc., a lower floor of the vehicle has been demanded. In response to such a demand, it has been considered to adopt a frame configuration in which the rear part of the frame located below the loading platform is made one step lower than the front part of the frame located below the cab by providing upper and lower kick portions on the side rails.

[0005] However, in a configuration where the upper and lower kick portions are provided on the frame, the rigidity of the upper and lower kick portions is likely to be insufficient, and there is a problem that the upper and lower kick portions are likely to be deformed or damaged during a frontal collision of the vehicle. Although it is possible to reinforce the upper and lower kick portions by adding separate members such as reinforcing parts, in this case, it will lead to complication of the configuration and increase in the weight of the vehicle due to an increase in the number of parts.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a vehicle frame structure that can suppress deformation and breakage of the upper and lower kick portions against a frontal collision while avoiding complication of the configuration and increase in weight.

Means for Solving the Problems

[0007] A vehicle frame structure according to one aspect of the present disclosure is a vehicle frame structure including a pair of left and right side rails extending in the front-rear direction of the vehicle, wherein the side rails include a front side rail positioned on the front side of the vehicle and supporting the front wheels and the cab, a rear side rail positioned on the rear side of the front side rail and supporting the rear wheels and the cargo bed, and an upper and lower kick portion connecting the rear side rail to the front side rail at a lower level, and a notch is provided in the front portion of the front side rail in the vehicle width direction.

[0008] In this vehicle frame structure, a notch is provided in the front portion of the front side rail in the vehicle width direction. Due to this notch, during a frontal collision of the vehicle, the portion of the front side rail in front of the notch is more likely to be actively crushed, and the efficiency of shock absorption can be improved. Therefore, it is possible to suppress deformation and breakage of the upper and lower kick portions against a frontal collision while avoiding complication of the configuration and increase in weight due to the addition of separate members such as reinforcing parts.

[0009] The front side rail is a hollow member with a rectangular cross-section formed by the connection of an outer rail located on the outer side in the vehicle width direction and an inner rail located on the inner side in the vehicle width direction. The notch may be formed at the corner of the inner rail. By forming the notch at the corner of the inner rail, it is possible to achieve both ensuring the rigidity of the front side rail and ease of crushing during a frontal collision. In addition, it is possible to suppress the spread of the crushed portion due to a frontal collision to the outer side in the vehicle width direction. Thereby, a decrease in the efficiency of shock absorption can be suppressed.

[0010] A flange portion extending in the longitudinal direction of the vehicle across the notch may be provided on the upper surface side of the inner rail. Thereby, it is possible to suppress the spread of the crushed portion due to a frontal collision upward of the vehicle. Therefore, the influence of the collision on the cab located above the front side rail can be mitigated.

[0011] The front side rail may further include a first cross member provided in the vehicle width direction so as to connect the portions on the rear side of the notch in the front side rail. By the arrangement of this first cross member, it is possible to suppress the spread of the front side rail in the vehicle width direction due to a frontal collision. Thereby, since the portion in front of the notch in the front side rail crushes more efficiently during a frontal collision, the efficiency of shock absorption can be further enhanced.

[0012] The front side rail may further include a suspension member that connects the portion on the rear side of the notch in the front side rail and the front portion of the rear side rail. In this case, the collision energy applied to the front side rail during a frontal collision can be dispersed to the rear side rail via the suspension member. Therefore, deformation and breakage of the upper and lower kick portions can be more reliably suppressed. In addition, since it is possible to suppress the spread of the front side rail upward of the vehicle during a frontal collision, the influence of the collision on the cab located above the front side rail can be more reliably mitigated.

[0013] The rear side rails are provided with a widened portion adjacent to the upper and lower kick portions, where the frame width is widened by making the rail interval larger than that of the front side rails. The widened portion includes a front portion of the rear side rail and a second cross member provided in the vehicle width direction so as to connect the tips of the front portions of the rear side rails. The suspension member may be connected to the front portion of the rear side rail via the second cross member.

[0014] Such a widened portion contributes to both securing the arrangement space for components such as batteries when the vehicle is an electric vehicle and securing the loading capacity due to the low floor of the vehicle. On the other hand, by connecting the suspension member to the front portion of the rear side rail via the second cross member that constitutes the widened portion, deformation or breakage of the second cross member during a frontal collision can be suppressed. Thereby, the protection of the on-vehicle load within the arrangement space is achieved.

Advantages of the Invention

[0015] According to the present disclosure, it is possible to suppress deformation and breakage of the upper and lower kick portions against a frontal collision while avoiding complication and weight increase of the structure.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0017] Hereinafter, with reference to the drawings, a preferred embodiment of the frame structure of a vehicle according to one aspect of the present disclosure will be described in detail.

[0018] FIG. 1 is a plan view showing a main part of a frame structure of a vehicle according to an embodiment of the present disclosure. Further, FIG. 2 is a side view of FIG. 1. The vehicle frame structure 1 shown in FIGS. 1 and 2 is a structure applied to a large vehicle such as a truck, for example, and has a ladder frame structure. The vehicle may be an electric vehicle that travels by driving a motor with electric power from a battery, for example.

[0019] The vehicle frame structure 1 includes a pair of left and right side rails 2, 2 extending in the front-rear direction of the vehicle, and a plurality of cross members 3, 4, 5 extending in the width direction of the vehicle and connecting the side rails 2, 2 to each other. The side rails 2, 2 and the cross members 3, 4, 5 are all composed of long metal members.

[0020] The side rails 2, 2 have a substantially symmetric shape and arrangement on the left and right. The side rail 2 includes a front side rail 11 located on the front side of the vehicle and supporting the front wheels 6 and the cab 7, a rear side rail 12 located on the rear side of the front side rail 11 and supporting the rear wheels (not shown) and the cargo bed 8, and an upper and lower kick portion 13 that connects the rear side rail 12 to the front side rail 11 at a lower level. Further, a suspension member 9 for supporting the front wheels 6 is provided on the side rail 2 by a suspension device such as a leaf spring.

[0021] The tips of the front portions 11a, 11a of the front side rails 11 are connected by a cross member 3. Further, the front portions 11a, 11a of the front side rails 11 are connected by a cross member (first cross member) 4 on the rear side of the cross member 3. Various components such as a motor, an inverter, and a gear of the vehicle are arranged in the space between the left and right front side rails 11, 11.

[0022] The rear side rails 12 are provided with a widened portion K where the frame width is widened by making the rail interval larger than the rail interval between the front side rails 11, 11. In the present embodiment, the widened portion K includes front portions 12a, 12a on the left and right rear side rails 12, a cross member 5 (second cross member) connecting the tips of the front portions 12a, 12a of the rear side rails 12, and a cross member (not shown) connecting the tips of the rear portions of the rear side rails 12, 12 on the rear side of the cross member 5. The widened portion K is provided adjacent to the vertical kick portion 13. The widened portion K forms a rectangle in plan view. In the space inside the widened portion K, for example, a high-voltage battery serving as a power source of the vehicle is arranged.

[0023] The vertical kick portion 13 continuously slopes gently downward and is connected to the cross member 5 of the widened portion K continuously with the rear portion 11b of the front side rail 11. That is, the vertical kick portion 13 is connected to the front portion 12a of the rear side rail 12 via the cross member 5 of the widened portion K. Due to the vertical kick portion 13, the rear side rail 12 is made one step lower than the front side rail 11, and thus the position of the loading platform 8 can be lowered. Thereby, ensuring the loading capacity of the vehicle is achieved.

[0024] The suspension member 9 is arranged at the height of the rear side rail 12 and extends in the longitudinal direction of the vehicle slightly inside the vehicle width direction from the front side rail 11. The front portion 9a of the suspension member 9 extends outward in the vehicle width direction toward the front side rail 11, and the tip of the front portion 9a is connected to the front portion 11a of the front side rail 11 by an anchor. The rear portion 9b of the suspension member 9 is suspended from the rear portion 11b of the front side rail 11 and is connected to the cross member 5 of the widened portion K. That is, the rear portion 9b of the suspension member 9 is connected to the front portion 12a of the rear side rail 12 via the cross member 5 of the widened portion K.

[0025] Next, the configuration of the front side rail 11 described above will be described in more detail. FIG. 3 is a perspective view showing the configuration of the front portion of the front side rail. As shown in the figure, the front side rail 11 is configured by connecting an outer rail 21 located on the outer side in the vehicle width direction and an inner rail 22 located on the inner side in the vehicle width direction.

[0026] The outer rail 21 has side plates 23 and flange portions 24 and 25 provided at the upper and lower ends of the side plates 23, respectively, and has a C-shaped cross section. Similar to the outer rail 21, the inner rail 22 has side plates 26 and flange portions 27 and 28 provided at the upper and lower ends of the side plates 26, respectively, and has a C-shaped cross section. The front side rail 11 is formed into a hollow member with a rectangular cross section by connecting the flange portions 27 and 28 of the inner rail 22 in a state where they are overlapped on the flange portions 24 and 25 of the outer rail 21.

[0027] A notch 30 is provided in the front portion 11a of the front side rail 11 in the vehicle width direction. The notch 30 is formed at a corner of the inner rail 22 at a certain interval from the tip of the front side rail 11. In the example of FIG. 3, rectangular notches 30 and 30 are provided at both the corner 22a formed by the side plate 26 and the upper flange portion 27 and the corner 22b formed by the side plate 26 and the lower flange portion 28. At the position of the notch 30, the internal space of the front side rail 11 is exposed from the inner rail 22 side. The positions of the two notches 30 and 30 with respect to the vehicle front-rear direction are equal to each other. Also, the widths of the two notches 30 and 30 with respect to the vehicle front-rear direction are equal to each other.

[0028] The flange portion 27 on the upper surface side of the inner rail 22 extends in the longitudinal direction of the vehicle straddling the notch portion 30. More specifically, this flange portion 27 extends from the tip of the front side rail 11 beyond the notch portion 30. On the rear side of the notch portion 30, the width of the flange portion 27 gradually decreases. In the rear portion where there is no flange portion 27, the inner rail 22 is composed of only the side plate 26 and the flange portion 28 on the lower surface side. Therefore, on the rear side of the notch portion 30, the upper surface of the front side rail 11 is formed only by the flange portion 24 on the upper surface side of the outer rail 21.

[0029] Also, as shown in FIGS. 1 and 2, the above-described cross member 4 is provided in the vehicle width direction so as to connect the portions behind the notch portion 30 in the front side rail 11. Further, in the present embodiment, the connection position P1 between the front portion 9a of the above-described suspension member 9 and the front portion 11a of the front side rail 11 coincides with the connection position P2 between the front side rail 11 and the cross member 4. The notch portion 30 and the connection positions P1 and P2 may be adjacent to each other or may be separated at a certain interval.

[0030] As described above, in the vehicle frame structure 1, a notch portion 30 is provided in the vehicle width direction at the front portion 11a of the front side rail 11. Due to this notch portion 30, when a frontal collision of the vehicle occurs, the portion in front of the notch portion 30 in the front side rail 11 is more likely to be crushed actively, and the efficiency of shock absorption can be improved. Therefore, it is possible to suppress the deformation and breakage of the upper and lower kick portions 13 against a frontal collision while avoiding the complication and weight increase of the configuration due to the addition of separate members such as reinforcing parts.

[0031] In this embodiment, the front side rail 11 is a hollow member with a rectangular cross-section formed by the coupling of an outer rail 21 located on the outer side in the vehicle width direction and an inner rail 22 located on the inner side in the vehicle width direction. And the notch 30 is formed at the corner portions 22a, 22a of the inner rail 22. By forming the notch 30 at the corner portions 22a, 22a of the inner rail 22 in this way, it is possible to achieve both ensuring the rigidity of the front side rail 11 and the ease of crushing during a frontal collision. Also, it is possible to suppress the spread of the crushed portion due to a frontal collision to the outer side in the vehicle width direction. Thereby, a decrease in the efficiency of shock absorption can be suppressed.

[0032] In this embodiment, a flange portion 27 extending in the longitudinal direction of the vehicle is provided so as to straddle the notch 30 on the upper surface side of the inner rail 22. Thereby, it is possible to suppress the spread of the crushed portion due to a frontal collision upward of the vehicle. Therefore, the influence of the collision on the cab 7 located above the front side rail 11 can be mitigated.

[0033] In this embodiment, a cross member 4 is provided in the vehicle width direction so as to connect the portions of the front side rail 11 behind the notch 30. By this arrangement of the cross member 4, it is possible to suppress the spread of the front side rails 11, 11 in the vehicle width direction due to a frontal collision. Thereby, since the portion of the front side rail 11 in front of the notch 30 is crushed more efficiently during a frontal collision, the efficiency of shock absorption can be further enhanced.

[0034] In the present embodiment, a suspension member 9 is provided to connect a portion of the front side rail 11 behind the notch 30 and the front portion 12a of the rear side rail 12. Thereby, the collision energy applied to the front side rail 11 during a frontal collision can be dispersed to the rear side rail 12 via the suspension member 9. Therefore, deformation and breakage of the upper and lower kick portions 13 can be more reliably suppressed. Further, since the front side rail 11 can be suppressed from spreading above the vehicle during a frontal collision, the influence of the collision on the cab 7 located above the front side rail 11 can be more reliably mitigated.

[0035] In the present embodiment, in the rear side rail 12, a widened portion K with a wider frame width is provided adjacent to the upper and lower kick portions 13 by making the rail interval larger than the rail interval between the front side rails 11, 11. And the suspension member 9 is connected to the front portion 12a of the rear side rail 12 via the cross member 5 of the widened portion K. The widened portion K contributes to both securing the arrangement space for, for example, a battery or the like when the vehicle is an electric vehicle and securing the loading capacity due to the low floor of the vehicle. On the other hand, by connecting the suspension member 9 to the front portion 12a of the rear side rail 12 via the cross member 5 constituting the widened portion K, deformation or breakage of the cross member 5 during a frontal collision can be suppressed. Thereby, protection of the in-vehicle cargo in the arrangement space can be achieved.

[0036] The present disclosure is not limited to the above embodiment. For example, in the above embodiment, in the front portion 11a of the front side rail 11, the notch 30 is provided on the inner rail 22 side, but the notch 30 may be provided on the outer rail 21 side. The notch 30 does not necessarily have to be provided at both of the corner portions 22a, 22b, and may be provided at only one of the corner portions 22a, 22b. The notch 30 may be provided not at the corner portions 22a, 22b but on the side plate 26. The front side rail 11 does not necessarily have to be constituted by the outer rail 21 and the inner rail 22, and may be constituted by a single hollow member.

[0037] The connection position P1 between the front portion 9a of the suspension member 9 and the front portion 11a of the front side rail 11 does not necessarily have to coincide with the connection position P2 between the front side rail 11 and the cross member 4. For example, the connection position P1 between the front portion 9a of the suspension member 9 and the front portion 9a of the front side rail 11 may be located on the rear side of the connection position P2 between the front side rail 11 and the cross member 4.

Explanation of reference numerals

[0038] 1... Frame structure of the vehicle, 2... Side rail, 4... Cross member (first cross member), 5... Cross member (second cross member), 6... Front wheel, 7... Cab, 8... Loading platform, 9... Suspension member, 11... Front side rail, 11a... Front portion, 12... Rear side rail, 12a... Front portion, 13... Upper and lower kick portions, 21... Outer rail, 22... Inner rail, 22a, 22b... Corner portions, 27... Flange portion, 30... Notch portion, K... Wide portion.

Claims

1. A vehicle frame structure comprising a pair of left and right side rails extending in the longitudinal direction of the vehicle, wherein the side rails include a front side rail positioned on the front side of the vehicle to support the front wheels and the cab, a rear side rail positioned on the rear side of the front side rail to support the rear wheels and the cargo bed, an up-and-down kick portion that connects the rear side rail to the front side rail at a lower level, and a notch is provided in a front portion of the front side rail in the vehicle width direction, the front side rail is a hollow member having a rectangular cross-section formed by the connection of an outer rail positioned on the outer side in the vehicle width direction and an inner rail positioned on the inner side in the vehicle width direction, the notch is formed at a corner of the inner rail, a flange portion extending in the longitudinal direction of the vehicle across the notch is provided on the upper surface side of the inner rail. A vehicle frame structure

2. The vehicle frame structure according to claim 1, further comprising a first cross member provided in the vehicle width direction so as to connect portions of the front side rail behind the notch

3. The vehicle frame structure according to claim 1 or 2, further comprising a suspension member that connects a portion of the front side rail behind the notch and a front portion of the rear side rail

4. On the rear side rail, a widened portion having a wider frame width by making the rail interval larger than that of the front side rail is provided adjacent to the up-and-down kick portion, the widened portion includes a front portion of the rear side rail and a second cross member provided in the vehicle width direction so as to connect the tips of the front portions of the rear side rail, The vehicle frame structure according to claim 3, wherein the suspension member is connected to the front portion of the rear side rail via the second cross member

5. A vehicle frame structure comprising a pair of left and right side rails extending in the longitudinal direction of the vehicle, wherein the side rails include a front side rail positioned on the front side of the vehicle to support the front wheels and the cab, a rear side rail positioned on the rear side of the front side rail to support the rear wheels and the cargo bed, It has an up-and-down kick portion that connects the rear side rail to the front side rail at a position one step lower. A notch is provided in the front portion of the front side rail in the vehicle width direction. A vehicle frame structure further includes a suspension member that connects a portion of the front side rail behind the notch and a front portion of the rear side rail.

6. On the rear side rail, a widened portion with a frame width widened by making the rail interval larger than that of the front side rail is provided adjacent to the up-and-down kick portion. The widened portion includes a front portion of the rear side rail and a second cross member provided in the vehicle width direction so as to connect the tips of the front portions of the rear side rail. The vehicle frame structure according to claim 5, wherein the suspension member is connected to the front portion of the rear side rail via the second cross member.

7. The front side rail is a hollow member with a rectangular cross section formed by the combination of an outer rail located on the outer side in the vehicle width direction and an inner rail located on the inner side in the vehicle width direction. The notch is formed at a corner of the inner rail. The vehicle frame structure according to claim 5 or 6.

8. A flange portion extending in the vehicle front-rear direction across the notch is provided on the upper surface side of the inner rail. The vehicle frame structure according to claim 7.

9. The vehicle frame structure according to any one of claims 5 to 7, further comprising a first cross member provided in the vehicle width direction so as to connect portions of the front side rail behind the notch. ​

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