JP2008230359A - Vehicle body structure of electric automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body structure of an electric automobile capable of securing both of an energy absorbing structure and controllability and stability. <P>SOLUTION: This vehicle body structure of an electric automobile is provided with a center member penetrating in a forward and backward direction of a vehicle of a vehicle body floor, and a lower support member extends forward of a vehicle while the center member penetrates through a member positioned in front of the vehicle body of the vehicle body floor. A collision energy absorbing structure is formed at a position at a rear part of the vehicle from a front suspension arm on the center member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle body structure of an electric vehicle, and more particularly to a vehicle body structure that ensures vehicle strength and energy absorption at the time of a collision.

Conventionally, as disclosed in Patent Document 1, the present applicant has proposed a vehicle body structure of an electric vehicle. In this publication, a lower girder-like body floor is formed by a lower side sill, a lower front cross member, and a lower rear cross member. From the center of the lower front cross member in the vehicle width direction, a lower support member that supports a front suspension arm that supports the front wheels extends in front of the vehicle.
Japanese Patent Application Laid-Open No. 2005-225452

  However, the following problems have been found in the above prior art. In other words, if the mounting strength of the front suspension is increased to ensure operability and the strength of the lower support member is increased, the mounting portion between the wheel and the suspension may be damaged first in the event of a forward collision. Even if not, a high deceleration occurs. At this time, the collision energy is directly input to the vehicle body floor or the front pillar via the wheels, and the necessary crushing stroke and energy absorption cannot be obtained. This is because the wheel foil is very hard and cannot function as an energy absorber.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a vehicle body structure for an electric vehicle capable of ensuring both an energy absorbing structure and a maneuverability. There is.

  In order to achieve the above-mentioned object, in the present invention, a vehicle body floor composed of a plurality of members formed in a cross beam shape, a lower support member extending forward from the vehicle width direction center of the vehicle body floor, and the lower A front suspension arm attached to the left and right of the support member and supporting a front wheel, and a vehicle body structure of an electric vehicle, provided with a center member penetrating in the vehicle front-rear direction of the vehicle body floor, the lower support member, A center member is a member that extends through the member positioned in front of the vehicle on the vehicle body floor and extends forward of the vehicle, and absorbs collision energy at a position on the center member and behind the front suspension arm. A structure is formed.

  Therefore, in the present invention, the center member structure is adopted, the front suspension is attached to the extending portion of the center member, and the collision energy absorbing structure is formed at a position behind the vehicle from the front suspension arm. It is possible to ensure a crushing stroke and enhance the energy absorption effect.

  Hereinafter, the best mode for carrying out the present invention will be described based on the first embodiment.

First, the configuration will be described.
FIG. 1 is a side view of a vehicle body structure of an electric vehicle according to the present invention. The electric vehicle of Example 1 is provided with a motor (not shown).

  The left and right side sills 1 and 1 are disposed at the left and right lower portions of the vehicle body and extend in the front-rear direction. The front end portions of the left and right side sills 1 and 1 are connected by a lower front cross member 2 extending in the vehicle width direction. Further, the rear end portions of the left and right side sills 1, 1 are connected by a lower rear cross member 3 extending in the vehicle width direction. The lower front cross member 2 and the lower rear cross member 3 are disposed at a center position in the vehicle width direction and are connected by a center member 4 extending in the vehicle front-rear direction.

  The front end 4a of the center member 4 passes through the lower front cross member 2 and protrudes toward the vehicle front side. On the other hand, the rear end 4b of the center member 4 penetrates the lower rear cross member 3 and protrudes toward the vehicle rear side. A seat belt anchor 24 is formed at the rear end 4b. A seat belt buckle 22 for fixing the seat belt 23 is attached to the seat belt anchor 24.

  A space formed by the left and right side sills 1, 1, the lower front cross member 2, the lower rear cross member 3, and the center member 4 accommodates a battery carrier (not shown) that is a motor drive source. In addition, in the inner space of the left and right side sills 1, 1, a vehicle body floor is set and a driver's seat (not shown) is installed.

  Left and right front pillars 5 and 5 extending upward from the left and right side sills 1 and 1 are attached to the front end portions of the left and right side sills 1 and 1, respectively. The left and right front pillars 5 and 5 are erected on the left and right side sills 1 and 1 with the upper side inclined to the front side of the vehicle.

  Front end portions of the left and right side pillars 6 and 6 are attached to the left and right front pillars 5 and 5. The left and right side pillars 6 and 6 are formed in a substantially U-shape, and the rear end portions thereof are supported by left and right rear pillars 7 and 7 that are erected rearward from the rear end portions of the left and right side sills 1 and 1. A vehicle interior is set in a space surrounded by the side sill 1 and the side pillar 6.

  The left and right rear pillars 7 and 7 are connected by a rear cross member 8 extending in the vehicle width direction. Brackets 10, 10 that support the upper end portions of the left and right shock absorbers 9, 9 are attached to the rear cross member 8. The lower end portions of the left and right shock absorbers 9 and 9 are connected to the rear ends of trailing arm type left and right rear suspension arms 11 and 11 attached to the lower rear cross member 3.

  Reinforcing plates (reinforcing plates) 12 and 12 are attached to the inner sides in the vehicle width direction of the left and right front pillars 5 and 5 and the left and right side pillars 6 and 6, respectively. A first upper cross member 13 extending in the vehicle width direction is installed between the reinforcing plates 12 and 12.

  The first upper cross member 13 is an upper end portion of the left and right reinforcing plates 12, 12 and is disposed in the vehicle interior, and a steering column support member 14 that supports steering (not shown) is attached.

  The left and right front pillars 5 and 5 are connected by a second upper cross member 15. The second upper cross member 15 is disposed at a general vehicle bumper height, for example, a height of about 500 to 600 mm. The joint between the second upper cross member 15 and the front pillar 5 is reinforced by the reinforcing plate 12 described above.

  The upper ends of the left and right front pillars 5 and 5 are connected by a third upper cross member 18 extending in the vehicle width direction. Near the both ends of the third upper cross member 18, a front suspension fixing portion 20 that supports the upper end portion of the shock absorber 19 is attached. The lower end of the shock absorber 19 is supported by a front suspension arm 19a attached to a bracket 21 attached to the center member front end 4a. A space between the front suspension fixing portion 20 and the bracket 21 is reinforced by a support member 22.

  FIG. 2 is a perspective view showing the configuration of the vehicle body floor portion. In this perspective view, only the left side of the front suspension arm 19a and the rear suspension arm 11 are shown, and the right side is not shown. Needless to say, the same configuration is actually provided on the left and right. The perspective view of FIG. 2 shows the same object from different viewpoints. FIG. 2A is based on the upper left front of the vehicle, and FIG. 2B is based on the upper left rear of the vehicle.

  The vehicle body floor is formed in a cross beam shape by the members 1, 2 and 3. Here, the side sill 1 is disposed at substantially the same position as the wheel in the vehicle width direction from the viewpoint of securing an area for storing the battery. A center member 4 is disposed through the lower front cross member 2 and the lower rear cross member 3 at the center of the vehicle body floor in the vehicle width direction. A plurality of batteries BAT are mounted on one or both of the left and right of the center member 4 in the vehicle body floor. The number of batteries may be one and is not particularly limited.

  The front end 4a functions as a lower support member extending from the vehicle body floor to the front of the vehicle, and a front suspension arm 19a attached to the left and right of the front end 4a so as to be rotatable around the front end 4a is attached. It has been. The front suspension arm 19a is supported by front wheels 1FR and 1FL equipped with a motor via an axle member and can be steered by a steering mechanism (not shown).

  In addition, a trailing arm type rear suspension arm 11 attached to the rear of the vehicle body floor so as to be rotatable about the lower rear cross member 3 is configured. Further, a seat belt anchor 24 is provided at the rear end 4b of the center member 4 extending through the vehicle rear from the vehicle body floor.

  FIG. 3 is a partially enlarged perspective view showing the configuration of the front end portion 4a. In this enlarged view, the structure of the joint portion between the front end portion 4a and the lower front cross member 2 will be mainly described. The lower front cross member 2 is provided with a through hole 2a through which the center member 4 passes. The through hole 2 a is formed larger than the outer shape of the center member 4. The through hole 2a is provided with an extending portion 2b extending inward, and the extending portion 2b and the center member 4 (front end portion 4a) are partially joined by welding.

  A reinforcing member 30 is fixed between the side surface 2c of the lower front cross member 2 and the upper surface of the front end portion 4a by welding. The reinforcing member 30 includes a center member coupling portion 30a welded to the upper surface portion of the front end portion 4a, and a lower front cross member extending obliquely from both sides of the center member coupling portion 30a toward the side surface 2c of the lower front cross member 2. It is a plate-shaped member comprised from the connection part 30b.

  Since the front suspension arm 19a is attached to the front end portion 4a, a cornering force that acts on the wheel during turning or the like is input as a lateral load. At this time, a bending moment that tends to bend in the left-right direction is generated in the front end portion 4a. If the front end portion 4a is deformed by the bending moment, it becomes difficult to ensure operability. Therefore, a plate-like reinforcing member 30 capable of securing strength against the bending moment in the left-right direction is attached.

  The plate-like reinforcing member 30 has a high strength because it acts on the bending moment in the left-right direction due to the tension-compression relationship, but it can be easily deformed by bending the input in the vehicle front-rear direction. ing.

  A crush promoting bead 31 is formed on each of the upper and lower surfaces of the front end portion 4a. The crushing promotion bead 31 on the upper surface side is provided between the center member coupling portion 30a and the lower front cross member 2 and behind the vehicle from the attachment point of the front suspension arm 19a. The crush promoting bead on the lower surface side is provided at a position facing the crush promoting bead 31 on the upper surface side. In addition, you may form over the perimeter of the front-end part 4a, and it does not specifically limit.

Next, the operation based on the above configuration will be described.
(About the front side action of the center member)
FIG. 4 is a schematic view showing the action at the time of collision between the vehicle body floor and the center member. It represents a collapsed portion of the center member 4 when the vehicle collides with the collision barrier and a load is applied to the wheels.

  If the joint portion between the front suspension arm 19a and the front end portion 4a is weakly formed, the operability cannot be ensured. Moreover, if the collision input input to the wheel is transmitted directly to the lower front cross member 2 or the side sill 1 via the wheel without passing through the front suspension arm 19a, the wheel foil or the like is a very hard structure. There is no absorption effect due to crushing, so shock absorption is not possible.

  Thus, the collision strength input to the wheel is input from the front suspension arm 19a to the center member 4 (front end 4a) while securing the attachment strength between the front suspension arm 19a and the front end 4a. Here, if the front suspension arm 19a is composed of an A arm and is connected to the front end 4a at two points, it is advantageous in securing toe rigidity, and the collision input acting on the wheel from the front is efficiently received from the front end 4a. Can communicate to. However, if the A arm is employed and the two points are connected, the distance in the front-rear direction between the connection point and the vehicle body floor cannot be secured, and a sufficient crushing stroke may not be secured.

  Therefore, the center member 4 and the lower front cross member 2 are partially joined. That is, in the electric vehicle of the first embodiment, a collision input is made to the bumper 17 and the like and a large force acts on the wheels at the time of a forward collision. At this time, the collision input transmitted to the wheels is input to the front end portion 4a via the front suspension arm 19a. Then, a buckle buckle occurs toward the rear of the vehicle starting from the crush promoting bead 31.

  In the first embodiment, all the members are basically formed of an aluminum hollow material, and the through hole 2a and the center member 4 are partially joined by welding. Even inside, it is possible to buckle, and even when the A arm is employed, a crushing stroke can be secured.

  A collision energy absorbing structure is formed by the partial joint with the through hole 2 a, the crush promoting bead 31, and the reinforcing member 30. In other words, it can be said that the collision energy absorbing structure is formed on the center member 4 at a position behind the vehicle from the front suspension arm 19a.

(About the rear side action of the center member)
On the other hand, at the rear of the vehicle, the rear pillar 7 is erected from the vehicle body floor so as to incline toward the rear of the vehicle, and a rear suspension arm 11 that supports the rear wheels is attached to the lower rear cross member 3. This rear suspension arm 11 is a trailing arm type, one end is rotatably supported with respect to the lower rear cross member 3, and the other end is connected to a strut provided on the rear pillar 7 via a shock absorber 9. It is attached.

  As described above, since the rear suspension arm 11 is a trailing arm type and the rear pillar 7 is tilted rearward, there is a strength member integrated with the vehicle body floor in the diagonally lower rear area from the position of the buckle 22 of the seat belt 23. No. Therefore, it is difficult to ensure the strength at the position where the seat belt anchor should be attached.

  Therefore, the seat belt anchor 24 is set at the rear end portion 4b, which is the center member 4 extending through the rear of the vehicle from the vehicle body floor. Since one center member 4 penetrating the vehicle body floor is configured, it is possible to sufficiently secure the strength, and it is possible to easily secure the strength member.

  As described above, the effects listed below can be obtained in the first embodiment.

  (1) A center member 4 that penetrates the vehicle body floor in the longitudinal direction of the vehicle is provided, and a lower front cross member 2 in which the center member 4 is positioned in front of the vehicle on the vehicle body floor is used as a lower support member that supports the suspension arm 19a. A collision energy absorbing structure is formed at the front end portion 4a penetrating and extending forward of the vehicle, on the center member 4 and at a position behind the vehicle from the front suspension arm 19a.

  As a result, even if the attachment strength between the suspension arm 19a and the center member 4 is ensured, it is possible to ensure a crushing stroke by the collision energy absorbing structure, and the suspension arm and the attachment portion of the wheel are damaged, and the vehicle body floor There is no direct impact input. Further, by ensuring the attachment strength between the suspension arm 19a and the center member 4, operability can be ensured.

  (2) It is formed in the lower front cross member 2 located on the vehicle front side of the vehicle body floor, and has a through hole 2a having a diameter larger than that of the center member 4 and extends from the inner periphery of the through hole 2a, and the center member 4 and the through hole 2a. And an extending portion 2b that partially connects the two. Thereby, the lantern buckling in the lower front cross member 2 can be achieved, and a crushing stroke can be secured.

  (3) Between the front end portion 4a which is an extended portion extending through the vehicle front from the vehicle body floor of the center member 4 and the lower front cross member 2, against the bending moment in the left-right direction of the front end portion 4a. A plate-shaped reinforcing member 30 that is strong and weak in the front-rear direction is set. Thereby, although it is strong in the bending moment of the left-right direction, the crushing stroke at the time of a front collision can be ensured. It can also function as a shock absorber.

  (4) As the collision energy absorbing structure, a crushing promotion bead 31 is provided on the center member 4 (front end 4a) and behind the front suspension arm 19a. Therefore, when the collision input transmitted to the wheels is transmitted to the center member 4 via the front suspension arm 19a, it is possible to reliably obtain an impact absorbing effect due to the lantern buckling.

  (5) The front suspension arm 19a is an A arm. By using the A arm, it is possible to support the front end portion 4a at two points, and toe rigidity can be ensured. At this time, since the crushing stroke is secured in the lower front cross member 2, there is no problem even if the distance from the vehicle body floor cannot be secured by the two-point support.

  (6) A trailing arm type rear suspension arm 11 rotatably attached to the vehicle body floor, a rear pillar 7 erected rearward from the vehicle rear of the vehicle body floor, and a rear end of the rear suspension arm 11 A shock absorber 9 provided between the rear pillar 7 and the upper part of the rear pillar 7 is provided, and a seat belt anchor 24 is set on the center member 4 that extends from the vehicle body floor to the rear of the vehicle. Therefore, since the single center member 4 that penetrates the vehicle body floor is configured, it is possible to sufficiently ensure the strength, and it is possible to easily secure the strength member.

(Other examples)
The best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to the first embodiment and does not depart from the gist of the present invention. Any change in the design of the range is included in the present invention.

  (7) The vehicle front-rear direction crushing strength of the extended portion of the center member 4 extending through the vehicle front from the vehicle body floor is determined by the vehicle front-rear direction crushing strength of the vehicle body floor portion passing through the vehicle body floor of the center member. You may set lower than intensity | strength. Thereby, a stable impact absorbing effect can be obtained.

  (8) As a method of setting the vehicle front-rear direction crushing strength, the cross-sectional area of the front end portion 4a that is the extending portion may be made smaller than the cross-sectional area of the center member 4 of the vehicle body floor portion.

  (9) Further, the plate thickness of the front end portion 4a which is the extending portion may be made thinner than the plate thickness of the center member 4 of the vehicle body floor portion. Further, the above (8) and (9) may be appropriately combined.

It is a side view to which the vehicle body structure of the electric vehicle of Example 1 is applied. It is a perspective view showing the structure of the vehicle body floor part to which the vehicle body structure of the electric vehicle of Example 1 is applied. It is a partial expansion perspective view showing the composition of the front end part to which the body structure of the electric vehicle of Example 1 is applied. It is the schematic showing the effect | action at the time of the collision with the vehicle body floor and center member in Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side sill 2 Lower front cross member 2a Through-hole 2b Extension part 2c Side surface 3 Lower rear cross member 4 Center member 4a Front end part 4b Rear end part 5 Front pillar 6 Side pillar 7 Rear pillar 8 Rear cross member 9 Shock absorber 11 Rear suspension arm 12 Reinforcing plate 13 First upper cross member 14 Steering column support member 15 Second upper cross member 18 Third upper cross member 19 Shock absorber 19a Front suspension arm 20 Front suspension fixing portion 21 Bracket 22 Seat belt buckle 22 Support member 22 Buckle 23 Seat Belt 24 Seat belt anchor 30 Reinforcing member 30a Center member coupling portion 30b Lower front cross member coupling portion 31 Promotion bead

Claims (9)

A vehicle body floor composed of a plurality of members formed in a cross beam shape,
A lower support member extending forward of the vehicle from the vehicle width direction center of the vehicle body floor;
A front suspension arm attached to the left and right of the lower support member and supporting the front wheel;
In the body structure of an electric vehicle equipped with
Providing a center member penetrating in the vehicle longitudinal direction of the vehicle body floor;
The lower support member is a member in which the center member extends through the member positioned in front of the vehicle on the vehicle body floor and extends in front of the vehicle,
A vehicle body structure for an electric vehicle, wherein a collision energy absorbing structure is formed on the center member and at a position behind the vehicle from the front suspension arm. In the vehicle body structure of the electric vehicle according to claim 1,
A through hole having a diameter larger than that of the center member;
A connecting portion extending from the inner periphery of the through hole and partially connecting the center member and the through hole;
A vehicle body structure for an electric vehicle, characterized by comprising: The electric vehicle body structure according to claim 1 or 2,
A plate that is strong against a bending moment in the lateral direction of the extending portion and weak in the front-rear direction between the extending portion of the center member that extends through the vehicle front from the vehicle body floor and the vehicle body floor. A vehicle body structure for an electric vehicle, characterized in that a reinforcing member having a shape is set. In the vehicle body structure of the electric vehicle according to any one of claims 1 to 3,
The electric vehicle body structure according to claim 1, wherein the collision energy absorbing structure is a crush-promoting bead formed on the center member and behind the front suspension arm. In the vehicle body structure of the electric vehicle according to any one of claims 1 to 4,
An electric vehicle body structure, wherein the front suspension arm is an A arm. The vehicle body structure of an electric vehicle according to any one of claims 1 to 5,
The vehicle front-rear direction crushing strength of the extended portion of the center member extending through the vehicle front from the vehicle body floor is greater than the vehicle front-rear direction crushing strength of the vehicle body floor portion passing through the vehicle body floor of the center member. The body structure of an electric vehicle, which is characterized by being set low. In the vehicle body structure of the electric vehicle according to claim 6,
A vehicle body structure for an electric vehicle, wherein the extending portion has a smaller cross-sectional area than the vehicle body floor portion. In the vehicle body structure of the electric vehicle according to claim 6 or 7,
A vehicle body structure for an electric vehicle, wherein the extension portion is thinner than the vehicle body floor portion. The vehicle body structure of an electric vehicle according to any one of claims 1 to 8,
A trailing arm type rear suspension arm rotatably attached to the vehicle body floor;
A rear pillar erected from the vehicle rear side of the vehicle body floor,
A rear suspension installed between a rear end of the rear suspension arm and an upper portion of the rear pillar;
Provided,
A vehicle body structure for an electric vehicle, wherein a seat belt anchor is set on the center member extending through the vehicle body floor from the vehicle rear side.

Images