JP2020011693A - Vehicle body frame structure - Google Patents

Abstract

To improve energy absorption performance in a vehicle body frame structure of an electric vehicle.SOLUTION: A vehicle body frame structure is a vehicle body frame structure of an electric vehicle and includes: a front bumper beam 1 disposed at a front end part of a vehicle body and extending in a vehicle width direction; two front crash boxes 2 being members which are attached to the front bumper beam 1, extend in a vehicle body fore and aft direction, and crush to absorb impact during a collision; two front side members 3, each of which supports a rear end part 2a of the front crash box 2 and extends in the vehicle body fore and aft direction; and at least one front bridge member 4 which extends in the vehicle width direction and connects the two front side members 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a frame structure of a vehicle body.

  High safety is required for the frame structure of the vehicle body. In particular, at the front and rear portions of the vehicle body, a frame structure having high collision safety performance is provided to protect the interior of the vehicle interior in the event of a collision. For example, a front bumper beam is attached to a front portion of the vehicle body, and the front bumper beam is connected to the vehicle body via a front crash box and a front side member. In the event of a forward collision, these members are crushed and absorb the impact, thereby protecting the interior of the vehicle interior. For example, Patent Document 1 discloses such a general frame structure of a vehicle body.

JP 2010-184706 A

  The frame structure of the vehicle body of Patent Document 1 is intended for an engine vehicle. In particular, when an engine is mounted on the front part of the vehicle body, it is necessary to provide an engine room between two front side members. In that case, the two front side members are provided independently with the engine room interposed therebetween. However, it is difficult for two independent front side members to exhibit high energy absorption performance. For example, in a front offset collision, only one of the two front side members must absorb the collision energy. Therefore, the collision energy may not be sufficiently absorbed, and there is room for improvement from the viewpoint of safety.

  An object of the present invention is to improve energy absorption performance in a frame structure of a vehicle body of an electric vehicle.

  A first aspect of the present invention is a frame structure of a vehicle body of an electric vehicle, comprising: a front bumper beam disposed at a front end of the vehicle body and extending in a vehicle width direction; A front crush box that is a member that absorbs shock by crushing at the time of collision, two front side members that support the rear end of the front crush box and extend in the front-rear direction of the vehicle body, A vehicle body frame structure comprising: at least one front bridge member extending to connect the two front side members.

  According to this configuration, since the electric vehicle is targeted, it is not necessary to provide an engine room between the two front side members at the front of the vehicle body. Therefore, the two front side members can be connected by the front bridge member. Thereby, the two front side members and the front bridge member are integrated, and the rigidity can be improved. Also, at the time of an offset collision, the collision load can be transmitted from one front side member to the other front side member via the front bridge member. Thereby, the collision load can be dispersed, and the performance of absorbing collision energy can be improved. With the improvement of the performance, the length of the front side member in the front-rear direction may be shorter than that of the conventional engine vehicle. The front side member and the front bridge member may be separate members, or may be an integral member.

  As viewed from the front of the vehicle body, the front bridge member and the front bumper beam may at least partially overlap in the vehicle height direction.

  According to this configuration, at the time of a forward collision, the front crash box and the front side member are crushed, and the front bumper beam and the front bridge member may come into contact. Therefore, the front bridge member also receives the collision load from the front bumper beam and is crushed, and can further absorb the collision energy.

  The front bridge member may be arranged so as to be hidden by the front bumper beam when viewed from the front of the vehicle body.

  According to this configuration, it is possible to receive a collision load from the front bumper beam on all but not a part of the front bridge member. Therefore, since the entire front bridge member can be crushed, more collision energy can be absorbed.

  The front bridge member and the front side member may be separate members, and the entire periphery of the end of the front bridge member may be joined to the front side member when viewed from the side of the vehicle body.

  According to this configuration, since the joining between the front side member and the front bridge member can be strengthened, their rigidity can be improved. Therefore, the energy absorption performance can be further improved.

  The front bridge member may be disposed substantially in the same plane as the front side member.

  According to this configuration, since the propagation of the collision load occurs in the same plane, the collision load can be prevented from being concentrated on any part, and the collision load can be widely dispersed. Here, being substantially arranged in the same plane means that the front bridge member and the front side member are arranged so that the same plane can be shared over the entire length.

  The front bridge member may be joined to a front half of the front side member.

  According to this configuration, at the time of a front collision, the front half of the front side member is likely to receive the collision load, and the front bridge member can be joined to the portion to disperse the collision load, so that the energy absorption performance can be further improved. .

  A second aspect of the present invention is a frame structure of a vehicle body of an electric vehicle, comprising: a rear bumper beam disposed at a rear end of the vehicle body and extending in a vehicle width direction; Rear crush box that is a member that extends in the front direction and is crushed in the event of a collision and absorbs an impact; two rear side members that support the front end of the rear crush box and extend in the front-rear direction of the vehicle body; And at least one rear bridge member that connects the two rear side members to each other.

  According to this configuration, since the electric vehicle is targeted, there is no need to provide an engine room between the two rear side members at the rear of the vehicle body. Therefore, the two rear side members can be connected by the rear bridge member. Thereby, the two rear side members and the rear bridge member are integrated, and the rigidity can be improved. Further, at the time of an offset collision, the collision load can be transmitted from one rear side member to the other rear side member via the rear bridge member. Thereby, the collision load can be dispersed, and the performance of absorbing collision energy can be improved. With the improvement of the performance, the length of the rear side member in the front-rear direction may be shorter than that of the conventional engine vehicle. The rear side member and the rear bridge member may be separate members or may be an integral member.

  When viewed from the rear of the vehicle body, the rear bridge member and the rear bumper beam may at least partially overlap in the vehicle height direction.

  According to this configuration, at the time of a rear collision, the rear crash box and the rear side member may be crushed, and the rear bumper beam and the rear bridge member may come into contact. Therefore, the rear bridge member also receives the collision load from the rear bumper beam and is crushed, so that the collision energy can be further absorbed.

  The rear bridge member may be arranged so as to be hidden by the rear bumper beam when viewed from the rear of the vehicle body.

  According to this configuration, it is possible to receive the collision load from the rear bumper beam in all but not a part of the rear bridge member. Therefore, since the entire rear bridge member can be crushed, more collision energy can be absorbed.

The rear bridge member and the rear side member are separate members,
When viewed from the side of the vehicle body, the entire periphery of the end of the rear bridge member may be joined to the rear side member.

  According to this configuration, since the joining between the rear side member and the rear bridge member can be strengthened, their rigidity can be improved. Therefore, the energy absorption performance can be further improved.

  The rear bridge member may be disposed substantially in the same plane as the rear side member.

  According to this configuration, since the propagation of the collision load occurs in the same plane, the collision load can be prevented from being concentrated on any part, and the collision load can be widely dispersed. Here, being substantially arranged in the same plane means that the rear bridge member and the rear side member are arranged so that the same plane can be shared over the entire length.

  The rear bridge member may be joined to a front half of the rear side member.

  According to this configuration, at the time of a rear collision, the rear half of the rear side member is likely to receive a collision load, and the rear bridge member can be joined to the portion to disperse the collision load, so that the energy absorption performance can be further improved.

  According to the present invention, in the frame structure of the body of an electric vehicle, the collision load can be dispersed by the front bridge member or the rear bridge member, so that the energy absorbing performance can be improved.

FIG. 1 is a perspective view of a frame structure of a vehicle body front portion according to a first embodiment of the present invention. FIG. 2 is a plan view of a frame structure of a front portion of the vehicle body according to the first embodiment. FIG. 2 is a front view of a frame structure at a front portion of the vehicle body according to the first embodiment. FIG. 3 is a side view of the frame structure of the front part of the vehicle body according to the first embodiment. FIG. 4 is a side view showing a joining state of the front side member according to the first embodiment. Bar graphs showing energy absorption for various structures. FIG. 5 is a plan view showing a modification of the frame structure of the front part of the vehicle body according to the first embodiment. FIG. 9 is a plan view of a frame structure of a rear portion of a vehicle body according to a second embodiment. The rear view of the frame structure of the rear part of the vehicle body concerning a 2nd embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 9 described below are all schematic.

(1st Embodiment)
FIG. 1 shows a frame structure of a vehicle body according to the first embodiment. The frame structure is a vehicle body front part for an electric vehicle.

  The frame structure of the vehicle body according to the present embodiment has an impact absorbing structure for protecting the interior of the vehicle compartment in the event of a forward collision. FIG. 2 is a plan view of the shock absorbing structure. In the shock absorbing structure, a front bumper beam 1, two front crash boxes 2, two front side members 3, a front bridge member 4, and two front suspension towers 5 are provided.

  The front bumper beam 1 is a member that is arranged at the front end of the vehicle body and extends in the vehicle width direction X. The central portion 1a of the front bumper beam 1 is a straight line extending in the vehicle width direction X, and both end portions 1b are slightly inclined toward the rear Y2. The shape of the cross section perpendicular to the longitudinal direction of the front bumper beam 1 is rectangular. However, the shape of the front bumper beam 1 is not particularly limited, and may be any shape.

  The front crash box 2 extends in the front-rear direction Y of the vehicle body, enters the front bumper beam 1, and is attached to the front bumper beam 1. The front crash box 2 has a lower rigidity than other members, and is a member that is crushed at the time of a collision and absorbs an impact.

  Referring also to the side view of FIG. 3, the front side members 3 extend in the front-rear direction Y of the vehicle body on both sides of the vehicle body. One end of the front side member 3 is connected to the rear end 2a of the front crash box 2 and supports the front crash box 2. The other end of the front side member 3 is connected to the front suspension tower 5. The front side member 3 is also a member that, together with the front crash box 2, is crushed at the time of collision and absorbs impact. The front side member 3 has a rectangular cross section perpendicular to the longitudinal direction. The central portion 3f of the front side member 3 is inclined from the horizontal so that the front portion 3d is located higher than the rear portion 3e. In the vehicle width direction X, two opposing inner side surfaces of the two front side members 3 are both flat surfaces, and the front bridge member 4 is connected thereto as described later.

  The front suspension tower 5 is a member that connects the front side member 3 and the main body 16 of the vehicle body. The front suspension tower 5 is a member made of steel or an aluminum alloy or the like, and has high rigidity.

  The front bridge member 4 is a separate member from the front side member 3. The front bridge member 4 is disposed between the two front side members 3 and orthogonal to them, and connects the two front side members 3. The front bridge member 4 is joined to the front half 3a of the front side member 3 (see FIG. 2). The front bridge member 4 has a rectangular cross section perpendicular to the longitudinal direction (see FIG. 3).

  FIG. 4 is a front view of the frame structure as viewed from the front of the vehicle body. Preferably, the front bridge member 4 and the front bumper beam 1 at least partially overlap in the vehicle height direction Z. More preferably, as in the present embodiment shown in FIG. 4, the front bridge member 4 is disposed so as to be hidden by the front bumper beam 1. Further, in this embodiment, the front bridge member 4 is disposed substantially in the same plane as the front side member 3. Here, "substantially arranged in the same plane" means that the front bridge member 4 and the front side member 3 are arranged so as to share the same plane S1 (see FIG. 3) over the entire length. Say.

  Referring to FIG. 2, in the present embodiment, both ends 4 a of front bridge member 4 are joined to side surfaces 3 b of front side member 3. When viewed from the side of the vehicle body with reference to FIG. 3, the entire rectangular periphery of both ends 4a of front bridge member 4 is welded to side surface 3b of front side member 3 (see a thick broken line in FIG. 3). It is preferable that the bonding be strong. Therefore, it is preferable that the entire circumference is welded as in the present embodiment, but the mode of joining is not limited to the entire circumference. For example, as shown in FIG. 5, a plurality of points may be spot-welded as welded portions 3c.

  FIG. 6 is a comparison graph of the amount of collision energy absorbed when a front offset collision occurs. The horizontal axis of the graph shows the test structures T1, T2, and T3, and the vertical axis shows the energy absorption (J). The test structure T1 is a conventional frame structure in which the front bridge member 4 is not provided. The test structure T2 is a frame structure formed by joining the front bridge member 4 to the front side member 3 by spot welding as shown in FIG. The test structure T3 is a frame structure in which the entire periphery of the front bridge member 4 is welded to the front side member 3 as in the present embodiment. FIG. 6 shows an analysis result when a forward offset collision was applied to these test structures T1, T2, and T3 under the same conditions. When the test structures T1, T2, and T3 were compared, the result was that the test structure T3 had the largest amount of energy absorption, the test structure T2 had the largest amount of energy absorption, and the test structure T1 had the smallest amount of energy absorption. Therefore, as the collision safety performance, the test structure T3 was the best, the test structure T2 was the next best, and the test structure T1 was the most unfavorable result.

  According to the vehicle body frame structure of the present embodiment, there are the following advantages.

  Since the frame structure of the vehicle body of the present embodiment is intended for an electric vehicle, there is no need to provide an engine room between the two front side members 3 at the front of the vehicle body. Therefore, the two front side members 3 can be connected by the front bridge member 4. Thereby, the two front side members 3 and the front bridge member 4 are integrated, and the rigidity can be improved. Also, at the time of an offset collision, the collision load can be transmitted from one front side member 3 to the other front side member 3 via the front bridge member 4. Thereby, the collision load can be dispersed, and the performance of absorbing collision energy can be improved. With the improvement of the performance, the length of the front side member 3 in the front-rear direction may be shorter than that of the conventional engine vehicle.

  Since the front bridge member 4 is arranged so as to be hidden by the front bumper beam 1, the front crash box 2 and the front side member 3 may be crushed at the time of a forward collision, and the front bumper beam 1 and the front bridge member 4 may come into contact. In particular, the entire front bridge member 4 can receive a collision load from the front bumper beam 1 instead of a part. Therefore, the front bridge member 4 also receives the collision load from the front bumper beam 1 and is crushed, and can further absorb the collision energy.

  Since the entire rectangular periphery (see the thick broken line in FIG. 3) of both ends 4a of the front bridge member 4 is welded to the side surface 3b of the front side member 3, the joining between the front side member 3 and the front bridge member 4 is firmly performed. Can be. Therefore, the integral rigidity of the front side member 3 and the front bridge member 4 can be improved. Therefore, the energy absorption performance can be further improved.

  Since the front bridge member 4 is disposed substantially in the same plane as the front side member 3, propagation of the collision load occurs in the same plane. Therefore, it is possible to suppress the collision load from being concentrated on any part, and to widely disperse the collision load.

  The front bridge member 4 is joined to a front half portion 3 a of the front side member 3. In the case of a forward collision, the front half of the front side member 3 is likely to receive a collision load, and the front bridge member 4 can be joined to this portion to disperse the collision load, so that the energy absorption performance can be further improved.

(Modification)
FIG. 7 shows a modification of the frame structure of the vehicle body of the first embodiment corresponding to FIG. In this modification, a U-shaped member 7 in which the front side member 3 and the front bridge member 4 are integrated is used.

  The U-shaped member 7 is formed by bending a straight columnar member into a U-shape by bending. One end of the U-shaped member 7 is connected to the rear end 2 a of the front crash box 2, and the other end is connected to the suspension bar 8. The suspension bar 8 is a member that connects the front suspension tower 5 and the U-shaped member. The U-shaped member 7 and the front suspension tower 5 may be directly connected without the suspension bar 8.

  According to this modification, since the U-shaped member 7 in which the front side member 3 and the front bridge member 4 are integrated is used, compared to the case where the front side member 3 and the front bridge member 4 are welded together, It can have a strong structure as an object.

(2nd Embodiment)
The frame structure of the vehicle body according to the second embodiment shown in FIG. This structure is substantially the same as the first embodiment shown in FIG. 2 in which the front and rear frame structure of the vehicle body front part is reversed. Therefore, a detailed description may be omitted.

  The frame structure of the vehicle body according to the present embodiment has an impact absorbing structure for protecting the interior of the vehicle cabin during a rear collision. FIG. 8 is a plan view of the shock absorbing structure. In the shock absorbing structure, a rear bumper beam 11, two rear crash boxes 12, two rear side members 13, a rear bridge member 14, and two rear suspension towers 15 are provided.

  The rear bumper beam 11 is a member disposed at the rear end of the vehicle body and extending in the vehicle width direction X. The central portion 11a of the rear bumper beam 11 has a linear shape extending in the vehicle width direction X, and both end portions 11b are slightly inclined toward the front Y1. The shape of the cross section perpendicular to the longitudinal direction of the rear bumper beam 11 is rectangular. However, the shape of the rear bumper beam 11 is not particularly limited, and may be any shape.

  The rear crash box 12 extends in the front-rear direction Y of the vehicle body and is attached to the rear bumper beam 11. The rear crash box 12 is a member having a lower rigidity than other members, and is crushed at the time of a collision to absorb an impact.

  The rear side members 13 extend in the front-rear direction Y of the vehicle body on both sides of the vehicle body. One end of the rear side member 13 is connected to the front end 12a of the rear crash box 12, and supports the rear crash box 12. The other end of the rear side member 13 is connected to a rear suspension tower 15. The rear side member 13 is also a member that, together with the rear crash box 12, is crushed at the time of collision and absorbs an impact. The rear side member 13 has a rectangular cross section perpendicular to the longitudinal direction. In the vehicle width direction X, two opposing inner surfaces of the two rear side members 13 are both flat surfaces, and the rear bridge member 14 is connected thereto as described later.

  The rear suspension tower 15 is a member that connects the rear side member 13 and the main body 16 of the vehicle body. The rear suspension tower 15 is a member made of steel or aluminum alloy or the like, and has high rigidity.

  The rear bridge member 14 is a separate member from the rear side member 13. The rear bridge member 14 is disposed between the two rear side members 13 so as to be orthogonal thereto, and connects the two rear side members 13. The rear bridge member 14 is joined to a rear half 13 a of the rear side member 13. The rear bridge member 14 has a rectangular cross section perpendicular to the longitudinal direction.

  FIG. 9 is a view corresponding to FIG. 4 of the first embodiment, and is a view in which the frame structure is viewed from behind the vehicle body. Referring to FIG. 9, preferably, rear bridge member 14 and rear bumper beam 11 at least partially overlap in the vehicle height direction Z. More preferably, as in the present embodiment shown in FIG. 9, the rear bridge member 14 is arranged so as to be hidden by the rear bumper beam 11. In the present embodiment, the rear bridge member 14 is disposed substantially in the same plane as the rear side member 13. Here, "substantially arranged in the same plane" means that the rear bridge member 14 and the rear side member 13 are arranged so as to share the same plane S2 over the entire length.

  In the present embodiment, both ends 14 a of the rear bridge member 14 are joined to the side surface 13 b of the rear side member 13. When viewed from the side of the vehicle body, the entire rectangular periphery of both ends 14a of the rear bridge member 14 is welded to the side surface 13b of the rear side member 13 similarly to the front bridge member 4 of the first embodiment. It is preferable that the bonding be strong. Therefore, it is preferable that the entire circumference is welded as in the present embodiment, but the mode of joining is not limited to the entire circumference.

  The advantages of the vehicle body frame structure of the present embodiment are substantially the same as those of the first embodiment except that the front-rear relationship is reversed.

  As described above, the specific embodiments of the present invention and the modifications thereof have been described. However, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, an embodiment of the present invention may be appropriately combined with the contents of the individual embodiments.

  Further, for example, the front bridge member 4 and the rear bridge member 14 are exemplified as one in each of the above embodiments, but two or more may be provided.

DESCRIPTION OF SYMBOLS 1 Front bumper beam 1a Center part 1b End part 2 Front crash box 2a Rear end part 3 Front side member 3a Front half part 3b Side surface 3c Welded part 3d Front part 3e Rear part 3f Center part 4 Front bridge member 4a End part 5 Front suspension tower Reference Signs List 6 Main body 7 U-shaped member 8 Suspension bar 11 Rear bumper beam 11a Center 11b End 12 Rear crash box 12a Front end 13 Rear side member 13a Half rear side 13b Side 14 Rear bridge member 14a End 15 Rear suspension tower

Claims (12)

A frame structure of a body of an electric vehicle,
A front bumper beam extending in the vehicle width direction arranged at a front end of the vehicle body;
Two front crash boxes that are attached to the front bumper beam, extend in the front-rear direction of the vehicle body, and are members that are crushed during a collision and absorb shock;
Two front side members that support the rear end of the front crash box and extend in the front-rear direction of the vehicle body;
A frame structure for a vehicle body, comprising: at least one front bridge member extending in a vehicle width direction and connecting the two front side members.   The vehicle body frame structure according to claim 1, wherein the front bridge member and the front bumper beam at least partially overlap in a vehicle height direction when viewed from the front of the vehicle body.   The vehicle body frame structure according to claim 2, wherein the front bridge member is arranged so as to be hidden by the front bumper beam when viewed from the front of the vehicle body. The front bridge member and the front side member are separate members,
The frame structure of a vehicle body according to any one of claims 1 to 3, wherein an entire periphery of an end of the front bridge member is joined to the front side member when viewed from a side of the vehicle body.   The vehicle body frame structure according to any one of claims 1 to 4, wherein the front bridge member is disposed substantially in the same plane as the front side member.   The vehicle body frame structure according to any one of claims 1 to 5, wherein the front bridge member is joined to a front half of the front side member. A frame structure of a body of an electric vehicle,
A rear bumper beam that is arranged at the rear end of the vehicle body and extends in the vehicle width direction;
Two rear crash boxes that are attached to the rear bumper beam, extend in the front-rear direction of the vehicle body, and are members that are crushed during a collision and absorb impact;
Two rear side members that support the front end of the rear crash box and extend in the front-rear direction of the vehicle body;
A frame structure for a vehicle body, comprising: at least one rear bridge member extending in a vehicle width direction and connecting the two rear side members.   The vehicle body frame structure according to claim 7, wherein the rear bridge member and the rear bumper beam at least partially overlap in the vehicle height direction when viewed from the rear of the vehicle body.   The frame structure of a vehicle body according to claim 8, wherein the rear bridge member is arranged so as to be hidden by the rear bumper beam when viewed from the rear of the vehicle body. The rear bridge member and the rear side member are separate members,
The frame structure of a vehicle body according to any one of claims 7 to 9, wherein an entire periphery of an end of the rear bridge member is joined to the rear side member when viewed from a side of the vehicle body.   The vehicle body frame structure according to any one of claims 7 to 10, wherein the rear bridge member is disposed substantially in the same plane as the rear side member.   The frame structure of a vehicle body according to any one of claims 7 to 11, wherein the rear bridge member is joined to a front half of the rear side member.

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