JP2012148691A - Vehicle body front structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a bulkhead upper to exhibit proper shock absorbing performance in a head-on collision of a vehicle.SOLUTION: A bulkhead 29 arranged in a vehicle body front part is constituted in a frame shape with a pair of right-left bulkhead sides 28 extending in the vertical direction, the bulkhead upper 26 extending in the lateral direction and a bulkhead lower 24 extending in the lateral direction. Since first fragile parts 28d constituted of a broken bead is formed in the bulkhead sides 28 projecting upward from front side frames 11, when a collision load from the front is applied to the bulkhead upper 26 by the head-on collision with a pedestrian, a shock added to the pedestrian can be reduced by sufficiently securing a shock absorbing stroke by moving the bulkhead upper 26 backward by bringing down upper parts of the bulkhead sides 28 backward by bending of the first fragile parts 28d.

Description

  According to the present invention, a frame-shaped bulkhead disposed at the front of the vehicle body is connected between the pair of left and right bulkhead sides that are connected to the left and right front side frames and extend in the vertical direction, and the upper end of the pair of left and right bulkhead sides. The present invention relates to a vehicle body front structure including a bulkhead upper to be connected and a bulkhead lower to connect the lower ends of the pair of left and right bulkhead sides.

  The left and right lower ends of the inverted U-shaped bulkhead upper are fastened to the front ends of the left and right front side frames with bolts so that they can rotate back and forth. When input, the front of the vehicle body reduces the impact applied to pedestrians by securing a sufficient shock absorbing stroke by causing the bulkhead upper to fall backward against the rotational resistance acting on the pivot at the lower end. The structure is known from Patent Document 1 below.

JP 2010-173556 A

  However, since the rotational resistance acting on the pivotal support at the lower end of the bulkhead upper depends on the bolt tightening torque, the bolt tightening torque is too strong to prevent the bulkhead upper from falling backward. Or the bolt tightening torque was too weak, and the bulkhead upper could easily fall backward, making it impossible to exhibit appropriate shock absorption performance.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to allow a bulkhead upper to exhibit appropriate shock absorbing performance at the time of a frontal collision of a vehicle.

  To achieve the above object, according to the first aspect of the present invention, a pair of left and right frame-shaped bulkheads arranged in the front of the vehicle body are connected to the left and right front side frames and extend in the vertical direction. In a vehicle body front structure including a bulkhead side, a bulkhead upper that connects between the upper ends of the pair of left and right bulkhead sides, and a bulkhead lower that connects between the lower ends of the pair of left and right bulkhead sides, A first fragile portion is formed on the pair of left and right bulkheads protruding upward from the front side frame, and when a collision load from the front is input to the bulkhead upper, the bending of the first fragile portion causes the An automobile body front structure is proposed in which the bulkhead upper is moved rearward.

  According to the invention described in claim 2, in addition to the structure of claim 1, when a second weakened portion is formed in the bulkhead upper and a collision load from the front is input to the bulkhead upper. A vehicle body front structure is proposed in which the bulkhead upper is bent backward by bending the second fragile portion.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect, a plurality of the second weakened portions are arranged along the longitudinal direction of the bulkhead upper, The second fragile portion located at the front side of the bulkhead upper is formed on the front surface of the bulkhead upper, and the second fragile portion located on the center side in the left-right direction is formed on the rear surface of the bulkhead upper. A vehicle front structure is proposed.

  According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, the first fragile portion is a folded bead or a notch. A vehicle body front structure is proposed.

  According to a fifth aspect of the present invention, in addition to the structure of any one of the second to fourth aspects, the second fragile portion is a folded bead or a notch. A vehicle body front structure is proposed.

  According to the invention described in claim 6, in addition to the structure of claim 5, the folded bead is formed of two triangles of three triangles forming a triangular pyramid, and includes a bottom wall and two side walls. A vehicle body front structure is proposed, which is formed so as to be opposed to the two side walls of a U-shaped member having a cross section.

  According to the invention described in claim 7, in addition to the configuration of claim 6, both ends of the bracket formed by bending the plate material into a square shape are formed on the two side walls so as to straddle the two folded beads. A vehicle body front structure characterized in that it is joined to the edge is proposed.

  According to an eighth aspect of the present invention, in addition to the configuration of any one of the fifth to seventh aspects, the folded bead is provided at a portion where a compressive force acts by a collision load. A car body front structure that characterizes the vehicle is proposed.

  According to the ninth aspect of the present invention, in addition to the configuration of any one of the fifth to seventh aspects, the notch is provided in a portion where a tensile force acts by a collision load. A car body front structure that characterizes the vehicle is proposed.

  According to the configuration of the first aspect, the frame-shaped bulkhead disposed in the front portion of the vehicle body includes a pair of left and right bulkhead sides that are connected to the left and right front side frames and extend in the vertical direction, and a pair of left and right bulkhead sides. And a bulkhead lower for connecting the lower ends of the pair of left and right bulkhead sides. Since the first fragile portion is formed on the pair of left and right bulkheads protruding upward from the front side frame, when a collision load from the front is applied to the bulkhead upper due to a frontal collision with a pedestrian, By bending the upper part of the bulkhead side backward by bending and moving the bulkhead upper backward, it is possible to secure a sufficient shock absorbing stroke and reduce the impact applied to the pedestrian.

  According to the second aspect of the present invention, since the second fragile portion is formed in the bulkhead upper, when the collision load from the front is input to the bulkhead upper, the bulkhead upper is bent due to the bending of the second fragile portion. The amount of backward movement of the bulkhead upper can be further increased by bending backward.

  According to the configuration of the third aspect, among the plurality of second fragile portions arranged along the longitudinal direction of the bulkhead upper, the second fragile portion positioned on the left and right end side is on the front surface of the bulkhead upper. Since the second weakened portion formed and located on the center side in the left-right direction is formed on the rear surface of the bulkhead upper, when a collision load is input to the bulkhead upper from the front, the bulkhead upper is the second on the end side. It is possible to secure the maximum amount of movement of the bulkhead upper in the rearward direction by deforming the fragile part so as to project forward and deforming the second fragile part on the central part side so as to project rearward.

  Moreover, according to the structure of Claim 4, since a 1st weak part is a bending bead or a notch, a 1st weak part can be reliably bent by a collision load.

  According to the fifth aspect of the present invention, since the second fragile portion is a bent bead or a notch, the second fragile portion can be reliably bent by a collision load.

  According to the configuration of claim 6, the folded bead is formed of two of the three triangles forming the triangular pyramid, and is formed on the two side walls of the U-shaped member having a bottom wall and two side walls. Since they are formed so as to be opposed to each other, when a bending moment acts on the member due to a collision load, it is possible to concentrate the stress on the folding bead and bend it reliably.

  Further, according to the configuration of claim 7, the two side walls of the bracket having the plate material bent in a square shape are formed at the two side walls at the edges of the two side walls of the U-shaped member having the bottom wall and the two side walls. Since it is connected so as to straddle two bent beads formed so as to face each other, the bracket can not only increase the amount of shock absorption due to deformation of the member, but also change the bracket-shaped bending angle This makes it possible to easily adjust the amount of shock absorption.

  According to the configuration of the eighth aspect, since the folding bead is provided at a portion where the compressive force acts due to the collision load, the folding bead is buckled by the compressive force and the member provided with the folding bead is reliably deformed. be able to.

  Further, according to the configuration of claim 9, since the notch is provided in the portion where the tensile force acts by the collision load, the notch can be opened by the tensile force to surely deform the member provided with the notch. it can.

The perspective view of the vehicle body front part of a motor vehicle. (First embodiment) FIG. 2 is a two-direction arrow view of FIG. 1. (First embodiment) FIG. 3 is a three-direction arrow view of FIG. 1. (First embodiment) FIG. 4 is a four-direction arrow view of FIG. 1. (First embodiment) FIG. (First embodiment) The graph explaining the effect of a weak part. (First embodiment) The figure corresponding to the said FIG. (Second Embodiment) The graph explaining the effect of a bracket. (Second Embodiment) The figure which shows other embodiment of a bulkhead upper. (Third embodiment)

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction and the left-right direction are defined with reference to an occupant seated in the driver's seat.

  As shown in FIGS. 1 to 4, a pair of left and right front side frames 11 and 11 extending in the front-rear direction are provided at the front of the vehicle body, and a pair of left and right middle side frames 12 and 12 are connected to the rear thereof. Is done. A dashboard 13 extending in the left-right direction stands between the front side frames 11 and 11 and the middle side frames 12 and 12, and the front engine room 14 and the rear vehicle compartment 15 are partitioned by the dashboard 13. . The pair of left and right front pillars 16 and 16 extend from the front edge of the roof panel 17 to the front lower side and the pillar uppers 18 and 18 from the front lower end of the pillar uppers 18 and 18 to the lower side along the side edge of the dashboard 13. And pillar lowers 19 and 19 connected to the front ends of the side sills 20 and 20.

  A pair of left and right front upper members 21, 21 extending forward and downward from the front lower ends of the pillar uppers 18, 18 are configured by rear upper members 22, 22 and front hanging parts 23, 23. The lower ends of the left and right hanging parts 23, 23 are connected by a bulkhead lower 24 extending in the left-right direction, and the left and right hanging parts 23, 23 are connected by a bumper beam 25 extending in the left-right direction above the connecting part. Between the front and rear intermediate portions of the left and right upper members 22, 22 are connected by a bulkhead upper 26 extending in the left-right direction, and the connecting portions are reinforced by gussets 27, 27. The middle part in the vertical direction of the pair of left and right bulkhead sides 28 and 28 is fixed to the inner surface in the left and right direction of the front side frames 11 and 11, and the upper end thereof is fixed to the lower surface in the vicinity of the left and right end of the bulkhead upper 26. The lower end is fixed to the upper surface of the bulkhead lower 24 in the vicinity of the left and right end portions.

  A bulkhead lower 24 made of a pipe material, a bulkhead upper 26 made of a pipe material, and a pair of left and right bulkhead sides 28, 28 made of a plate material having a U-shaped cross section constitute a square frame-shaped bulkhead 29 inside. A radiator or a condenser of an air conditioner (not shown) is supported.

  In the space surrounded by the front side frames 11, 11, the front upper members 21, 21 and the dashboard 13, the wheel houses 31, 31 of the front wheels 30, 30 and the front damper housings 32, 32 are arranged. Further, the front side frames 11 and 11 and the hanging parts 23 and 23 are connected by connecting members 33 and 33 for reinforcement made of pipe material.

  As shown in FIG. 5, the bulkhead side 28 is a member obtained by press-molding a metal plate into a U-shaped cross section, and includes a front bottom wall 28a and left and right side walls 28b extending rearward from both left and right ends of the bottom wall 28a. 28b, and the left and right side walls 28b, 28b are open rearward. The left and right side walls 28 b, 28 b have concave portions 28 c, 28 c bent in a crank shape, and one concave portion 28 c is coupled so as to fit into the front side frame 11.

  The left and right first fragile portions 28d, 28d made of bent beads are formed slightly above the recesses 28c, 28c of the left and right side walls 28b, 28b of the bulkhead side 28 so as to face each other. Each folded bead is composed of surfaces a and b made of two triangles of three triangles forming a triangular pyramid that tapers from the rear edge to the front edge of the side wall 28b.

  As shown in FIGS. 3 and 4, the bulkhead upper 26 is connected to the front upper members 21, 21 extending in the left-right direction from both ends of the first portion 26 a located at the center in the left-right direction and the first portion 26 a. The left and right second portions 26b and 26b are inclined obliquely upward toward the first portion 26a in the front view, and the first portion 26a is disposed horizontally. Each of the left and right second portions 26b, 26b close to the connecting portion with the front upper members 21, 21 is formed with one second weakened portion 26c made of a notch, and on the rear surface of the central first portion 26a. Are formed with three second fragile portions 26d formed of notches.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When an automobile collides with an obstacle such as a pedestrian in front, the pedestrian whose leg is pushed by the front bumper falls backward, so that the bulkhead upper 26 passes through the front hood from the thigh or waist of the pedestrian. The collision load is input to. When a collision load from the front is input to the bulkhead upper 26, as shown in FIG. 5, a backward load is applied from the second portions 26b, 26b on the left and right sides of the bulkhead upper 26 to the upper ends of the left and right bulkhead sides 28. In addition, a bending moment is applied to the upper part of the bulkhead side 28 around the recess 28c coupled to the front side frame 11.

  Due to this bending moment, stress concentrates on the first fragile portions 28d, 28d made of bent beads formed on the left and right side walls 28b, 28b of the bulkhead side 28, and the upper surface a, a and the lower surface b, b is compressed so as to approach each other, and the left and right side walls 28b, 28b are buckled so as to open outward. As a result, the upper part of the bulkhead side 28 falls backward with the first fragile portions 28d and 28d as the center, so that the bulkhead upper 26 connecting the upper ends of the left and right bulkhead sides 28 and 28 moves backward with a large stroke. Moving.

  At the same time, the bulkhead upper 26 to which a collision load from the front is input is deformed so that the second fragile portions 26c and 26c formed by notches formed on the front surfaces of the left and right second portions 26b and 26b are opened. The left and right second portions 26b and 26b are convexly curved forward. Further, the central first portion 26a of the bulkhead upper 26 is deformed so that the second fragile portions 26d formed by three notches formed on the rear surface thereof are opened, and the central first portion 26a is rearward. Curves convexly. In this way, the first portion 26a and the second portions 26b, 26b of the bulkhead upper 26 are curved, so that the bulkhead upper 26 moves further rearward, and the first fragile portions 28d, Coupled with the backward movement due to the bending of 28d, the shock absorbing stroke of the bulkhead upper 26 can be increased to ensure sufficient shock absorbing performance.

  FIG. 6A shows the time change of the load applied to the pedestrian from the bulkhead upper 26 at the time of a collision, the solid line is the present invention, the broken line is the first fragile portion 28d, 28d and the second fragile portion 26c, 26c, The comparative example which does not have 26d ... is shown. As is apparent from the figure, the load of the present invention is significantly reduced compared to the comparative example.

  FIG. 6B shows the change over time of the rearward movement amount (shock absorbing stroke) of the bulkhead upper 26 due to a collision. The solid line indicates the present invention, and the broken lines indicate the first fragile portions 28d and 28d and the second fragile portion 26c. , 26c, 26d,... As is apparent from the figure, the amount of backward movement of the present invention is significantly increased compared to the comparative example.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 7, in the second embodiment, a bracket 34 is provided so as to cover the rear of the left and right first weakened portions 28 d and 28 d of the bulkhead side 28. The bracket 34 includes a main body portion 34a obtained by bending a metal plate into a square shape at a bent portion, and an attachment portion formed on both upper and lower ends of the main body portion 34a and welded to the outer surfaces of the left and right side walls 28b and 28b of the bulkhead side 28. 34b...

  By adding the bracket 34 to the bulkhead side 28, when the bulkhead side 28 bends backward at the first weakened portions 28d and 28d due to a frontal collision, an arbitrary load is applied to the pedestrian from the bulkhead upper 26. Can be adjusted.

  FIG. 8A shows the time change of the load applied to the pedestrian when the offset amount O (see FIG. 7) of the bracket 34 is changed, and the load decreases as the offset amount O increases. I understand that

  FIG. 8B shows the load applied to the pedestrian when the bracket 34 having a small offset amount O (see the solid line in FIG. 7) is provided alone (see the solid line) and the bracket 34 having a large offset amount O (see FIG. 7). The load (see the chain line) when a single unit is provided (see the chain line) and the load (see the broken line) when the two brackets 34, 34 are provided in an overlapping manner are shown. Thus, by using a plurality of brackets 34 in combination, the characteristics of the load applied to the pedestrian from the bulkhead upper 26 can be adjusted more finely.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the bulkhead upper 26 is made of a pipe material, but the bulkhead upper 26 of the third embodiment is made of a metal plate bent into a hat-shaped cross section with the bottom surface open. The

  In the example of FIG. 9A, the second fragile portion 26c where the compressive load is applied by the collision load, that is, the second fragile portion 26c of the second portion 26b of the bulkhead upper 26 is configured by a folded bead. .

  In the example of FIG. 9B, the second weakened portion 26d where the tensile load is applied by the collision load, that is, the second weakened portion 26d of the first portion 26a of the bulkhead upper 26 is notched (opened). ).

  Also according to the third embodiment, it is possible to achieve the same operational effects as those of the first embodiment.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the first fragile portions 28d and 28d of the bulkhead side 28 can be configured with notches instead of bent beads.

  Moreover, the number of the 1st weak parts 28d and the 2nd weak parts 26c and 26d is not limited to embodiment, It can change suitably.

  In the embodiment, both the left and right ends of the bulkhead upper 26 are connected to the upper members 21 and 21, but when they are not connected to the upper members 21 and 21, the second portions 26b and 26b of the bulkhead upper 26 are connected. The second fragile portions 26c, 26c are not necessary, and only the second fragile portions 26d of the first portion 26a are required.

  In the embodiment, the bulk head 29 is constituted by four members, that is, the bulk head lower 24, the bulk head upper 26, and the left and right bulk head sides 28, 29. However, the bulk head 29 is divided and constituted. Is optional.

11 Front side frame 24 Bulk head lower 26 Bulk head upper 26c Second fragile portion 26d Second fragile portion 28 Bulk head side 28a Bottom wall 28b Side wall 28d First fragile portion 29 Bulk head 34 Bracket

Claims (9)

A pair of left and right bulkhead sides (28) extending in the vertical direction by a frame-shaped bulkhead (29) disposed at the front of the vehicle body connected to the left and right front side frames (11), and the pair of left and right bulkheads In a vehicle body front structure including a bulkhead upper (26) for connecting the upper ends of the sides (28) and a bulkhead lower (24) for connecting the lower ends of the pair of left and right bulkhead sides (28). ,
A first fragile portion (28d) is formed on the pair of left and right bulkhead sides (28) protruding upward from the front side frame (11), and a collision load from the front is input to the bulkhead upper (26). Sometimes, the front body structure of a vehicle body moves the bulkhead upper (26) backward by bending the first fragile portion (28d).   A second weakened portion (26c, 26d) is formed in the bulkhead upper (26), and when a collision load from the front is input to the bulkhead upper (26), the second weakened portion (26c, 26d) The vehicle body front structure according to claim 1, wherein the bulkhead upper (26) is bent backward by bending of the vehicle body.   A plurality of the second fragile portions (26c, 26d) are arranged along the longitudinal direction of the bulkhead upper (26), and the second fragile portions (26c) located on the side in the left-right direction are the bulk. The said 2nd weak part (26d) formed in the front surface of a head upper (26) and located in the left-right direction center part side is formed in the rear surface of the said bulkhead upper (26), It is characterized by the above-mentioned. The vehicle body front structure described in 1.   The vehicle body front structure according to any one of claims 1 to 3, wherein the first fragile portion (28d) is a bent bead or a notch.   The vehicle body front structure according to any one of claims 2 to 4, wherein the second fragile portion (26c, 26d) is a bent bead or a notch.   The folded bead is composed of two of three triangles forming a triangular pyramid, and the two side walls (28b) of the U-shaped member having a bottom wall (28a) and two side walls (28b). The vehicle body front structure according to claim 5, wherein the vehicle body front structure is formed so as to face each other.   The both ends of the bracket (34) which bent the board | plate material in the shape of a character are couple | bonded with the edge part of the said 2 side wall (28b) so that said 2 folding beads may be straddled. Car body front structure.   The vehicle body front structure according to any one of claims 5 to 7, wherein the bent bead is provided at a portion where a compressive force is applied by a collision load.   The vehicle body front part structure according to any one of claims 5 to 7, wherein the notch is provided in a portion where a tensile force is applied by a collision load.

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