Vehicle cross member reinforcement member

Abstract

To increase an absorption amount of impact energy at the time of a side collision and suppress deformation of a vehicle body at the center in a vehicle width direction.SOLUTION: A reinforcement member 40 attached to the inside of a fourth cross member 30 connecting left and right rockers 11L, 11R in a vehicle width direction includes: a center portion 41 disposed at the center in the vehicle width direction at which a battery back 60 is mounted; a left end portion 43L; and a left connection portion 42L. The upper surface of the left end portion 43L is offset upward from the upper surface of the center portion 41 in a height direction. The left connection portion 42L is inclined upward from the center portion 41 toward the left end portion 43L. The center portion 41 and the left connection portion 42L constitute a high proof strength portion 48 with high rigidity. The left end portion 43L constitutes a left low proof strength portion 49L with rigidity lower than the high proof strength portion 48.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a structure of a vehicle cross member reinforcing member that is attached to the inside of a cross member that connects left and right rockers of a vehicle in the vehicle width direction. [Background technology]

[0002] Patent Document 1 discloses a structure in which a battery pack is mounted on the upper side of a cross member that connects the left and right rockers in the vehicle width direction, in which a bent portion that bends toward the rear of the vehicle is provided on the outer side of the cross member in the vehicle width direction from the battery pack, and a reinforcing member is provided on the center side of the bent portion in the vehicle width direction. In this configuration, the bent portion bends and deforms toward the rear of the vehicle in the event of a side collision of the vehicle, absorbing collision energy and preventing damage to the battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 054076 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, even in hybrid vehicles that are driven by an engine and a motor, there is a demand for an increased cruising distance for EV driving that runs only on the motor, and the battery pack is becoming larger. In hybrid vehicles, the battery pack is mounted under the floor, and high-voltage components such as a charger are mounted on the floor under the rear seat. For this reason, when the battery pack becomes larger, the height of the cross member is limited under the rear seat, so the rigidity of the cross member cannot be made sufficiently high, and there is a possibility that deformation of the vehicle body will interfere with the battery in the event of a side collision of the vehicle. In addition, the larger size of the battery pack reduces the distance between the left and right side ends of the vehicle and the side ends of the battery pack, and there is a risk that the amount of impact energy absorbed in the event of a side collision will be insufficient.

[0005] Therefore, the vehicle cross member reinforcement member disclosed herein aims to increase the amount of impact energy absorbed by the end of the cross member during a side collision, while also suppressing deformation of the vehicle body in the center of the vehicle's width direction during a side collision. [Means for solving the problem]

[0006] The vehicle cross member reinforcement member disclosed herein is a vehicle cross member reinforcement member that is attached inside a cross member that has a closed cross section and is arranged on each of the left and right sides of the vehicle and connects left and right rockers extending in the fore-and-aft direction of the vehicle in the vehicle width direction, and is characterized in that it extends in the vehicle width direction and has a central portion in the center of the vehicle width direction, left and right end portions, and connecting portions that respectively connect the central portion to each of the end portions, the upper surface of each of the end portions is offset upward in the height direction from the upper surface of the central portion, and each of the connecting portions is inclined diagonally upward from the central portion toward each of the end portions, the central portion and each of the connecting portions constitute a high-strength portion with high rigidity, and each of the end portions constitutes a low-strength portion with lower rigidity than the high-strength portion.

[0007] With this structure, in the event of a side collision, the end portion is crushed in the vehicle width direction, and the tip of the end portion is bent and deformed so as to rotate downward around the boundary area with the connection portion. This increases the amount of impact energy absorbed. In addition, the high strength portion can suppress deformation of the vehicle body in the center of the vehicle width direction in the event of a side collision.

[0008] In the vehicle cross member reinforcement member of the present disclosure, the central portion and each of the connection portions have a groove-shaped cross section that is open toward the bottom of the vehicle, and each of the end portions may have an L-shaped cross section composed of a vertical flange extending toward the bottom of the vehicle and a horizontal flange extending toward the rear of the vehicle.

[0009] In this way, by changing the cross-sectional shape, it is possible to form a high-strength portion with high rigidity and a low-strength portion with lower rigidity than the high-strength portion, thereby simplifying the structure.

[0010] In the vehicle cross member reinforcement member of the present disclosure, a reduced-strength portion may be provided in each boundary region between each of the end portions and each of the connection portions.

[0011] This makes it possible to stabilize the deformation mode of the end portion during a side collision.

[0012] In the vehicle cross member reinforcement member of the present disclosure, a notch may be provided in each boundary region between each of the lateral flanges and each of the connection portions.

[0013] This makes it possible to stabilize the deformation mode of the end portion during a side collision with a simple configuration.

[0014] In the vehicle cross member reinforcement member of the present disclosure, each of the lateral flanges on the rocker side of each of the cutouts may be provided with at least one concave seating surface, and at least one of the concave seating surfaces may be provided with a through hole.

[0015] This reduces the strength of the lateral flange on the rocker side relative to the notch, allowing this portion to easily collapse in the vehicle width direction in the event of a side collision, thereby increasing the amount of impact energy absorbed. Effect of the Invention

[0016] The vehicle cross member reinforcement member disclosed herein increases the amount of impact energy absorbed by the end of the cross member during a side collision, and can suppress deformation of the vehicle body at the center of the vehicle's width during a side collision. [Brief description of the drawings]

[0017] [Figure 1] 1 is a plan view showing a vehicle underbody structure including a fourth cross member to which a reinforcing member according to an embodiment is attached. FIG. [Diagram 2] 2 is a cross-sectional view taken along the line AA of FIG. 1, showing an elevational view of a reinforcing member attached inside from the rear side of the front plate of a fourth cross member. [Diagram 3]2 is a detailed view of part B shown in FIG. 1, and is a plan view of the reinforcing member viewed from above with the upper plate of the fourth cross member removed. FIG. [Figure 4] 4 is a cross section CC shown in FIG. 3, showing the cross-sectional shape of the central portion of the reinforcing member. FIG. [Diagram 5] 4 is a cross section taken along line DD in FIG. 3, showing a cross section of the left end portion of the reinforcing member. FIG. [Figure 6] 11 is an explanatory diagram showing deformation of a fourth cross member and a reinforcing member during a side collision. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a vehicle cross member reinforcing member 40 (hereinafter referred to as reinforcing member 40) will be described with reference to the drawings. First, with reference to FIG. 1, a description will be given of the undercarriage of a vehicle 100 including a fourth cross member 30 with a reinforcing member 40 attached thereto. The arrows FR, UP, and RH shown in each drawing indicate the front, upper, and right side of the vehicle 100, respectively. The opposite directions of the arrows FR, UP, and RH indicate the rear, lower, and left side. Hereinafter, when the directions of front-rear, left-right, and up-down are used in the description, they refer to front-rear in the front-rear direction, left-right in the left-right direction, and up-down in the up-down direction of the vehicle 100, unless otherwise specified.

[0019] As shown in Figure 1, the undercarriage of the vehicle 100 includes left and right rockers 11L, 11R, left and right side members 12L, 12R, left and right rear side members 13L, 13R, left and right first cross members 15L, 15R, left and right second cross members 16L, 16R, a third cross member 17, a fourth cross member 30, fifth and sixth cross members 18, 19, a floor panel 20, a rear floor panel 21, and a floor tunnel 22.

[0020] The left rocker 11L and the right rocker 11R are skeletal members with a rectangular closed cross section, disposed on the left and right sides of the vehicle 100, and extending in the vehicle longitudinal direction. The left side member 12L and the right side member 12R are skeletal members that connect the left and right front side members (not shown) at the front of the vehicle and the left and right rear side members 13L and 13R in the vehicle longitudinal direction. The third cross member 17 and the fourth cross member 30 are skeletal members that connect the left rocker 11L and the right rocker 11R in the vehicle width direction. The fifth and sixth cross members 18 and 19 are skeletal members that connect the left and right rear side members 13L and 13R in the vehicle width direction. The floor panel 20 is a plate-shaped member that is attached between the left rocker 11L and the right rocker 11R, and constitutes the floor of the vehicle compartment. The rear floor panel 21 is a plate member that is attached between the left rear side member 13L and the right rear side member 13R, and constitutes the floor of the luggage compartment. The floor tunnel 22 is a groove-shaped cross-section member that protrudes upward from the floor panel 20 and is open on the lower side, and is a skeletal member that connects a dash panel (not shown) at the front of the vehicle and the third cross member 17 in the vehicle longitudinal direction. The left first cross member 15L and the left second cross member 16L are skeletal members that connect the left rocker 11L and the floor tunnel 22, and the right first cross member 15R and the right second cross member 16R are skeletal members that connect the right rocker 11R and the floor tunnel 22. In addition, a battery pack 60 is mounted below the floor panel 20. The battery pack 60 contains a battery that supplies power to a motor for driving the vehicle.

[0021] The fourth cross member 30 is a rectangular closed section member extending in the vehicle width direction. A reinforcing member 40 is attached inside the fourth cross member 30. The reinforcing member 40 is composed of a central portion 41, a left end portion 43L, a right end portion 43R, a left connection portion 42L, and a right connection portion 42R. The central portion 41 is a portion disposed in the center of the vehicle width direction where the battery pack 60 is mounted. The left end portion 43L and the right end portion 43R are end portions on the left rocker 11L and right rocker 11R sides, respectively. The left connection portion 42L connects the central portion 41 and the left end portion 43L, and the right connection portion 42R connects the central portion 41 and the right end portion 43R.

[0022] As shown in Figs. 2 and 4, the fourth cross member 30 is a rectangular closed cross section member composed of an upper plate 31, a lower plate 32, a front plate 33, and a rear plate 34. The upper plate 31 is inclined obliquely upward from the center in the vehicle width direction where the battery pack 60 is mounted toward the left rocker 11L, then extends horizontally to the left, and is connected to the upper surface of the left rocker 11L. The lower plate 32 is inclined obliquely downward from the center in the vehicle width direction toward the left rocker 11L, then extends horizontally to the left, and is connected to the lower surface of the left rocker 11L. As shown in Fig. 3, the front plate 33 and the rear plate 34 are slightly curved toward the rear of the vehicle from the center in the vehicle width direction toward the left rocker 11L, then extend leftward, and are connected to the inner side surface of the left rocker 11L in the vehicle width direction. The right side configuration of the fourth cross member 30 is symmetrical to the left side configuration, so illustration and description are omitted.

[0023] As shown in FIG. 4, the central portion 41 of the reinforcing member 40 has a groove-shaped cross section that is open toward the bottom of the vehicle. Although not shown, the left connecting portion 42L also has a groove-shaped cross section that is open toward the bottom of the vehicle, like the central portion 41. As shown in FIG. 5, the left end portion 43L has an L-shaped cross section that is composed of a vertical flange 431L extending toward the bottom of the vehicle and a horizontal flange 432L extending toward the rear of the vehicle. The right connecting portion 42R has a groove-shaped cross section similar to the left connecting portion 42L, and the right end portion 43R has an L-shaped cross section similar to the left end portion 43L. The central portion 41, the left connecting portion 42L, and the right connecting portion 42R form a high-strength portion 48 (see FIG. 2) with high rigidity in a groove-shaped cross section. The left end portion 43L and the right end portion 43R form a left low-strength portion 49L and a right low-strength portion with lower rigidity than the high-strength portion 48 in an L-shaped cross section.

[0024] Returning to FIG. 2, the upper surface of the left end portion 43L is offset upward in the height direction from the upper surface of the central portion 41, and extends horizontally to the left. The left connecting portion 42L is inclined obliquely upward from the central portion 41 toward the left end portion 43L. As shown in FIG. 2 and FIG. 3, a rectangular base 51 protruding upward is provided on the upper surfaces of the central portion 41 and the left connecting portion 42L of the reinforcing member 40. In addition, a semicircular base 52 protruding forward of the vehicle is provided on the front surfaces of the central portion 41, the left connecting portion 42L, and the left end portion 43L.

[0025] As shown in Fig. 2, the upper surfaces of the plurality of pedestals 51 provided on the upper surface of the central portion 41 and the left connecting portion 42L contact the lower surface of the upper plate 31 of the fourth cross member 30 and are fastened to the upper plate 31 by spot welding. Also, as shown in Fig. 3, the front surfaces of the plurality of pedestals 52 provided on the front surface of the central portion 41, the left connecting portion 42L and the left end portion 43L contact the rear surface of the front plate 33 and are fastened to the front plate 33 by spot welding. In this manner, the central portion 41 of the reinforcing member 40 is fastened to the central portion of the upper plate 31 of the fourth cross member 30, the left connecting portion 42L and the right connecting portion 42R are connected to the inclined portion of the upper plate 31, and the left end portion 43L and the right end portion 43R are fastened to the horizontal portion where the upper plate 31 is connected to the upper surfaces of the left and right rockers 11L and 11R.

[0026] As shown in FIG. 3, a notch 52L is provided in the horizontal flange 432L in the boundary region between the left end 43L and the left connecting portion 42L. The portion of the horizontal flange 432L where the notch 52L is provided constitutes the left strength reduced portion 46L. Two square concave seating surfaces 55 are provided in the horizontal flange 432L to the left of the notch 52L. Each concave seating surface 55 is provided with a through hole 56 penetrating the horizontal flange 432L. The region where the two concave seating surfaces 55 and the through holes 56 are provided constitutes a buckling deformation region 47L that buckles and absorbs impact energy during a side collision. The configuration of the right end 43R is symmetrical to that of the left end 43L, so a description thereof will be omitted.

[0027] Next, referring to FIG. 6, the deformation of each part when the pole 80 enters from the left side of the vehicle 100 will be described. As shown by the outline arrow 91 in FIG. 6, when the pole 80 enters, the rocker 11L is crushed, and then the buckling deformation area 47L where the concave seat surface 55 and the through hole 56 are provided is buckled and crushed in the vehicle width direction. Furthermore, when the pole 80 enters, as shown by the arrow 92 in the figure, the tip of the left end 43L is bent and deformed so as to rotate downward around the left strength reduction part 46L where the notch 52L is provided. At this time, the upper plate 31, the lower plate 32, the front plate 33, and the rear plate 34 of the part of the fourth cross member 30 connected to the left rocker 11L are crushed in the vehicle width direction, similar to the buckling deformation area 47L of the reinforcing member 40. The buckling deformation of the reinforcing member 40 and the fourth cross member 30 and the bending deformation of the left end 43L of the reinforcing member 40 can increase the amount of impact energy absorbed in a side collision.

[0028] In addition, the center portion 41 and the left connecting portion 42L constituting the high strength portion 48 of the reinforcing member 40 receive the impact load during a side collision, so that deformation of the vehicle body at the center in the vehicle width direction during a side collision can be suppressed. This makes it possible to suppress deformation of the vehicle body at the center in the vehicle width direction on which the battery pack 60 is mounted, and interference with the battery pack 60.

[0029] As described above, the reinforcing member 40 of the embodiment increases the amount of impact energy absorbed by the end of the fourth cross member 30 during a side collision, and suppresses deformation of the vehicle body at the center of the vehicle width during a side collision, thereby suppressing interference between the battery pack 60 and the vehicle body.

[0030] In the above description, the vehicle 100 has been described as having the battery pack 60 mounted below the floor panel 20, but the battery pack 60 may be mounted, for example, above the rear floor panel 21. The vehicle 100 may also be an engine-driven vehicle that does not have the battery pack 60 mounted thereon. In this way, when the battery pack 60 is not mounted below the floor panel 20, the center portion 41 of the reinforcing member 40 may be disposed between the left side member 12L and the right side member 12R, the left connection portion 42L and the left end portion 43L may be disposed between the left side member 12L and the left rocker 11L, and the right connection portion 42R and the right end portion 43R may be disposed between the right side member 12R and the right rocker 11R. [Explanation of symbols]

[0031] 11L left rocker, 11R right rocker, 12L left side member, 12R right side member, 13L left rear side member, 13R right rear side member, 15L first left cross member, 15R first right cross member, 16L second left cross member, 16R second right cross member, 18 fifth cross member, 19 sixth cross member, 20 floor panel, 21 rear floor panel, 22 floor tunnel, 30 fourth cross member, 31 upper plate, 32 lower plate, 33 front plate, 34 rear plate, 40 reinforcement member (vehicle cross member reinforcement member), 41 center portion, 42L left connection portion, 42R right connection portion, 43L left end portion, 43R right end portion, 46L left strength reduced portion, 47L buckling deformation area, 48 high strength portion, 49L left low strength portion, 51, 52 Base, 52L cutout, 55 concave seat, 56 through hole, 60 battery pack, 80 pole, 100 vehicle, 431L vertical flange, 432L horizontal flange.

Claims

1. A vehicle cross member reinforcing member that is attached to the inside of a cross member that connects left and right rockers in a vehicle width direction and that are arranged on each of the left and right sides of a vehicle and extend in the vehicle front-rear direction with a closed cross section, The vehicle width direction extends, and the vehicle width direction includes a central portion, left and right end portions, and connection portions that connect the central portion and each of the end portions, An upper surface of each of the end portions is offset upward in the height direction from an upper surface of the central portion, Each of the connection portions is inclined obliquely upward from the central portion toward each of the end portions, the central portion and each of the connection portions constitute a high-strength portion having high rigidity, and each of the end portions constitutes a low-strength portion having a lower rigidity than the high-strength portion; A reinforcing member for a vehicle cross member comprising:

2. 2. The vehicle cross member reinforcing member according to claim 1, The central portion and each of the connection portions have a groove-shaped cross section that is open toward the bottom of the vehicle, Each of the ends has an L-shaped cross section formed of a vertical flange extending downwardly of the vehicle and a horizontal flange extending rearwardly of the vehicle; A reinforcing member for a vehicle cross member comprising:

3. 3. A vehicle cross member reinforcing member according to claim 1 or 2, a strength-reduced portion is provided at each boundary region between each of the end portions and each of the connection portions; A reinforcing member for a vehicle cross member comprising:

4. 3. The vehicle cross member reinforcing member according to claim 2, A notch is provided in each boundary area between each of the horizontal flanges and each of the connection portions; A reinforcing member for a vehicle cross member comprising:

5. 5. The vehicle cross member reinforcing member according to claim 4, At least one concave seat is provided on each of the lateral flanges on the side of each of the rockers relative to each of the cutouts; At least one of the concave seating surfaces is provided with a through hole; A reinforcing member for a vehicle cross member comprising:

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