JPH1178966A - Frame structure of forward vehicle body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently absorb the collision energy during the offset collision. SOLUTION: Extensions 9 having recessed beads 10 are provided in forward end parts of right the left side members 5, 6, and a front cross member 13 is inserted in insertion holes in inner side surface 11 of extensions 9. The front cross member 13 is welded to opening edges of the insertion hole, and right and left stopper are provided on right and left ends accommodated in the extension 9, 9. A second cross member 25 is pierced through a through hole opened at a part retracted from the tip of the right and left side members 5, 6. Right and left frame front side members 31, 32 inclined rearward R of a vehicle body are provided on a front end of the extensions 9, 9, and supported by right and left end parts 26, 27 of the second cross member 25 rearward R of the vehicle body through right and left stay brackets 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front frame structure of a vehicle body having an impact energy absorbing structure.

[0002]

2. Description of the Related Art FIG. 4 is a view showing a conventional frame 81 in which front end portions of left and right side members 82 and 83 are formed in a Y-shape so that collision energy at the time of a frontal collision can be stably absorbed. The configuration is shown (see JP-A-8-164869).

The frame 81 includes left and right side members 82 and 83, main members 84 and 84 provided on extensions of the side members 82 and 83, and extends diagonally forward from the side members 82 and 83. Of the main members 8
The distal ends of the reinforcement members 4 and 84 and the reinforcing members 85 and 85 are fixed to the front cross member 86. In addition, the left and right side members 82 and 83 are connected at their distal ends by a second cross member 87 at the base end of the joint between the main member 84 and the reinforcing member 85.

[0004]

However, in the frame 81, as shown in FIG. 5, at the time of an offset collision in which an impact is input from a portion shifted leftward from the center of the vehicle body, the collision energy E is reduced. The main member 84 to be absorbed by the axial crush is a reinforcing member 85.
Will be reinforced. As a result, the collision energy E concentrates on the connecting portion 91 between the main member 84 and the reinforcing member 85, so that the connecting portion 91 may be broken and the amount of energy absorption may be reduced.

In order to prevent this, the connecting portion 91
It is also possible to reliably absorb the collision energy E by the main member 84, the reinforcing member 85, and the axial crush, but in this case, the front cross member 86 has a left end located at the rear of the vehicle body. Force acts in the direction of tilting displacement. However, the right end of the front cross member 86 is firmly fixed by the main member 84 at the tip of the right side member 83 and the reinforcing member 85. Therefore, the front cross member 86 may be broken at the central portion 92 by the force in the tilting direction, and there is a concern that the energy absorption amount may be reduced.

The present invention has been made in view of such conventional problems, and has as its object to provide a frame structure at a front portion of a vehicle body that can efficiently absorb collision energy at the time of an offset collision. Is what you do.

[0007]

In order to solve the above-mentioned problems, in the frame structure of the front part of the vehicle body according to the present invention, a front cross member connecting both side members is provided at the tip of the left and right side members. A frame front side member extending to the side of the vehicle body is provided at the tip of each side member, and a second cross member is penetrated through a portion retracted from the tip of the left and right side members, and the two sides of the second cross member are provided. A stay bracket for supporting the frame front side member from the rear side of the vehicle body is provided at a portion protruding from the member.

That is, at the time of an offset collision in which an external force applied from the front of the vehicle body is input to a portion shifted to the left from the center line of the frame, the external force is input to the left side member of the frame in the length direction. And a second cross member extending in the vehicle width direction through the left and right side members via a frame front side member provided on the left side member and a stay bracket supporting the frame front side member. Input in the width direction.

In addition, each of the frame front side members extending to the vehicle body side from the front ends of the both side members is inclined toward the rear of the vehicle body, and the second cross member penetrates from the front ends of the side members. Within the range up to the site, a deformation accelerating portion that promotes deformation of the side member by input from the tip of each side member was set.

That is, the left side member to which the external force from the front is input in the longitudinal direction is axially crushed by the deformation promoting portion set within a range from the tip to the portion where the second cross member is penetrated. Is promoted. For this reason, at the time of the external force input, since the length dimension from the tip of the left side member to the portion through which the second cross member has penetrated is shortened, the tip is inclined toward the rear of the vehicle body from the tip of the left side member. The extending frame front side member is tilted in a direction along the vehicle width direction, that is, in a direction extending perpendicular to the input.

Further, both ends of the front cross member are fixed while penetrating the inner surfaces of the side members, and stoppers are provided at both ends of the front cross member to prevent the front cross member from coming off from the penetrated inner surface. Provided.

That is, with the axial crush of the left side member due to the input to the left side member, a stress is generated in the front cross member in a direction of pulling the right side member toward the left side member. At this time, the front cross member is fixed with both ends penetrating the inner side surfaces of the side members.
In the energy absorption step, the input energy is absorbed when the fixed state between the front cross member and each side member is released. Further, stoppers are provided at both ends of the front cross member, which have been released from the fixed state with the side members, to prevent the front cross member from coming off from the penetrated inner surface. The energy is absorbed when the front cross member pulls the right side member toward the left side member and bends the right side member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a frame 1 of a vehicle body according to the present embodiment, in which a front end portion of the frame 1 is illustrated.

That is, at the front end of the left and right side members 5 and 6 constituting the frame 1, an extension 9 formed in a closed cross section from the extension lower 7 and the extension upper 8 is provided. In 9, concave beads 10, 10 are formed as deformation promoting portions bulging inward along the outer peripheral surface. As shown in FIG. 2, insertion holes 12, 12 are formed in the inner side surface 11 of the extensions 9, 9, and the left side member 5 and the right side member are provided in both the insertion holes 12, 12. 6, a front cross member 13 made of a pipe material is inserted. Both ends of the front cross member 13 are fitted with the insertion holes 1
It is fixed in a state of being welded to the opening edges of 2, 12,
Side surface of the front cross member 13 and the insertion hole 1
Welding portions 14 and 14 are formed at the portions with the opening edges 2 and 12, respectively. Further, left and right stoppers 15, 16 having a diameter larger than the inner diameter of the insertion holes 12, 12 are provided at the left and right ends of the front cross member 13 accommodated in the extensions 9, 9, respectively. The front cross member 13 is prevented from coming out of the insertion holes 12, 12 even when the welded portions 14, 14 fixing the opening 13 of the insertion holes 12, 12 to the insertion holes 12, 12 are peeled off. Is configured.

At the part retreated from the front ends of the left and right side members 5 and 6, through holes 21 and 21 penetrating left and right are provided. , 6 are reinforced by reinforcing plates 24,... Provided on the inner side surface 22 and the outer side surface 23. In each of the through holes 21 and 21 provided in the left and right side members 5 and 6, a second cross member 25 made of a pipe material is held in a penetrating state. The left end 26 and the right end 27 of the second cross member 25 protrude.

At the front ends of the extensions 9, 9, right and left frame front side members 31, 32 extending to the side of the vehicle body are provided in a state inclined toward the rear R of the vehicle body. The members 31 and 32 are left and right pipe stay brackets 3.
3, 34 and support stay sides 35, 36 for reinforcing the stay brackets 33, 34, at the left end 26 and the right end 27 of the second cross member 25 projecting from the left and right side members 5, 6. It is supported from the rear R side of the vehicle body.

The left and right side members 5 and 6 are attached to the left and right frame front side members 31 and 3, respectively.
2, body mounts 42, 42 having circular holes 41, 41 are provided at intermediate portions between the left end 26 and the right end 27 of the second cross member 25 so as to protrude to the side. A bumper stay 4 for supporting a bumper (not shown) while being bolted to bumper mount brackets 43, 43 welded to the left and right side members 5, 6, between the front side member 31 and the left and right frame members 32.
4, 44 are provided.

The present embodiment according to the above configuration is shown in FIG.
This will be described with reference to FIG. That is, when an external force G applied from the front of the vehicle body F is offset from a portion shifted to the left from the center line of the frame 1, the external force G
Are divided into two members: a left side member 5 and a second cross member 25 extending in the vehicle width direction through the left and right side members 5 and 6 via the left frame front side member 31 and the left stay bracket 33. As a result, the tip of the left side member 5 is formed in a Y shape by the main member and the reinforcing member, and the external force G
Is dispersed in both members, and then recombined at the binding portion of both members, which breaks the binding portion and lowers the energy absorption compared to the conventional method, which could reduce the energy absorption. It is possible to reliably prevent the absorption amount from decreasing.

The external force G is input to the left side member 5 in the length direction and is input to the second cross member 25 in the width direction. In the main body and the reinforcing member formed in a shape, the input is performed in the length direction, and the axial crushing of one member is strengthened by the other member. Axial crush can be promoted. Further, the left and right side members 5, 5 in the present embodiment.
In 6, the concave beads 10, 10 are formed along the outer peripheral surfaces of the extensions 9, 9 provided at the front end, so that axial crushing of the left side member 5 can be further promoted. Thereby, the collision energy at the time of the offset collision can be efficiently absorbed.

The concave beads 10, 10 are set within a range from the tip of each of the side members 5, 6 to a portion through which the second cross member 25 penetrates. The length of the left side member 5 within the range can be reduced. For this reason, the inclination angle of the left frame front side member 31, which is provided to be inclined toward the vehicle rear R from the tip of the left side member 5, extends perpendicularly to the input of the external force G from the front F. The external force G can be tilted in the direction in which the external force G is input, so that the length dimension facing the front F side can be changed from L1 to L2 as shown in FIG. Therefore, the pressure receiving area of the external force G in the left frame front side member 31 can be increased.

Further, since the left side member 5 is axially crushed and its length is shortened, a stress F1 is generated in the front cross member 13 to be pulled toward the left side member 5. At this time, since the front cross member 13 is welded in a state where both ends thereof penetrate the inner side surfaces 11, 11 of the extensions 9, 9 provided at the distal end portions of the side members 5, 6, the first cross member 13 is welded. In the energy absorption step, the input energy of the external force G is applied to the front cross member 1.
Welding portion 14 for fixing 3 and each side member 5, 6;
It is absorbed when the fixed state between the front cross member 13 and the side members 5 and 6 is released by peeling off the front cross member 14. In addition, at both ends of the front cross member 13 where the fixed state with the side members 5 and 6 is released,
Since the right and left stoppers 15 and 16 for preventing the insertion from the insertion holes 12 and 12 are provided, in the second energy absorption stage, the input energy of the external force G is applied to the front cross member 13 by the front cross member 13. The right side member 6 is pulled toward the left side member 5 and is absorbed when the right side member 6 is bent toward the left side member 5 as shown in FIG.

As described above, since the energy of the external force G can be absorbed through two energy absorption stages, when the left side member 5 is axially crushed and the front cross member 13 tilts, the front cross member 13 is tilted. 13 is firmly fixed to the tip of the right side member 6 by a Y-shaped main member and a reinforcing member, and a reaction force is generated in a direction that hinders the tilting. The right side member 6 can be surely bent while preventing the front cross member 13 from being broken, as compared with the related art in which the center cross section may be broken. Therefore, it is possible to prevent a decrease in the amount of energy absorption due to the bending of the front cross member 13.

In the present embodiment, the front and rear ends of the left and right side members 5 and 6 are provided with extensions 9 and 9 on the outer peripheral surface of the extension 9 as a deformation promoting portion which swells inward. Although the example in which the concave beads 10 and 10 are formed has been described as an example, in order to promote the deformation of the side members 5 and 6 due to the input from the tip of each side member 5 and 6, that is, the axial crush, the protrusion is outward. A convex bead may be formed, or a plurality of holes may be provided in the outer peripheral surface.

[0024]

As described above, in the frame structure of the front part of the vehicle body according to the present invention, the external force input from the front left side at the time of an offset collision passes through the left side member and the left and right side members, and Since the input is distributed to two members, the second cross member extending in the width direction, the tip of the side member is formed in a Y shape by the main member and the reinforcing member, and the external force is distributed to both members. After that, by being re-synthesized at the binding portion of both members, this binding portion is broken, and compared with the conventional case where the energy absorption amount may be reduced.
A reduction in the amount of energy absorption can be reliably prevented. Further, the external force is input in the length direction to the left side member, and is input in the width direction to the second cross member.
The left side member is input in the length direction in both the main member and the reinforcing member formed in a Y-shape and compared with the conventional case in which the axial crush in one member is reinforced by the other member. Can be promoted. Thereby, the collision energy at the time of the offset collision can be efficiently absorbed.

[0025] Further, a deformation accelerating portion for promoting deformation of the side member by an input from the tip of each side member is set within a range from a tip of each side member to a portion through which the second cross member penetrates. By the way, when the external force is input, within a range from the tip to the portion where the second cross member has penetrated,
The axial crush of the left side member can be promoted. Then, when the external force is input, the length dimension of the left side member in this range can be shortened. Therefore, at the time of the offset collision in which the external force is input from the front on the left side, the vehicle body is positioned rearward of the tip of the left side member. The frame front side member inclined and extended toward can be tilted in a direction extending perpendicularly to an input from the front. Thereby, the pressure receiving area of the external force in the frame front side member can be increased.

Further, both ends of the front cross member are fixed while penetrating the inner surface of each side member, and stoppers are provided at both ends of the front cross member to prevent the front cross member from coming off from the penetrated inner surface. By providing, when stress is applied to the front cross member to pull the right side member toward the left side member due to the axial crush of the left side member due to the external force, the fixed state of the front cross member and each side member is changed. A first energy absorbing step of absorbing the external force when releasing, and a front cross member, which is prevented from coming off from each side member by a stopper, when bending the right side member toward the left side member. A second energy absorption step for absorbing the external force It can absorb energy through the two stages. Therefore, when the left side member is axially crushed and the front cross member tilts, the right end of the front cross member is firmly fixed by the Y-shaped main member and the reinforcing member at the tip of the right side member. The front cross member is fixed, and a reaction force is generated in a direction that hinders the tilting. The member can be reliably bent. Thus, it is possible to prevent a reduction in the amount of energy absorption due to the bending of the front cross member.

[0027]

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of the present invention.

FIG. 2 is a schematic plan view showing the embodiment.

FIG. 3 is an explanatory diagram showing a deformation at the time of an offset collision of the embodiment.

FIG. 4 is a plan view showing a conventional frame.

FIG. 5 is an explanatory diagram showing a deformation at the time of an offset collision of the conventional example.

[Explanation of symbols]

 1 frame 5 left side member 6 right side member 10 concave bead 11 inner surface 13 front cross member 15 left stopper 16 right stopper 25 second cross member 31 left frame side member 32 right frame side member 33 left stay bracket 34 right stay bracket

Claims (3)

[Claims] 1. A front cross member for connecting both side members is provided at a distal end portion of each of the left and right side members, and a frame front side member extending to a vehicle body side is provided at a distal end of each of the side members. The second cross member is made to penetrate a portion retreated from the tip of the left and right side members, and a stay bracket for supporting the frame front side member from the rear side of the vehicle body is provided at a portion of the second cross member projecting from the both side members. A frame structure at the front of the vehicle body. 2. Each of the frame front side members extending to the vehicle body side from the front end of each of the side members is inclined toward the rear of the vehicle body, and the second cross member is penetrated from the front end of each of the side members. 2. A frame structure for a front part of a vehicle body according to claim 1, wherein a deformation accelerating portion for encouraging deformation of said side member by an input from a tip of each side member is set within a range up to the part. 3. Both ends of the front cross member,
While fixing with the inner side surface of each of the side members penetrated, at both ends of the front cross member,
3. A frame structure for a front part of a vehicle body according to claim 1, wherein a stopper is provided for preventing the inner surface from penetrating.