JP6566018B2 - Vehicle shock absorption structure - Google Patents

Description

  The present invention relates to a shock absorbing structure for a vehicle having a frame member made of a resin material.

  Conventionally, a pair of left and right side frames are provided at the front end side (front part or rear part) in the longitudinal direction of the vehicle, and a pair of left and right shock absorbers capable of absorbing impact energy at the time of collision at the front end parts of these side frames. A structure in which a bumper reinforcement extending in the vehicle width direction is attached via a crash can as a structure is known.

  These pair of crash cans are usually formed of a metal material, and absorb impact energy transmitted to the passenger compartment by being compressed and broken in the axial direction at the time of a vehicle collision.

  Since the crash can is a large part, it is also known to be formed of a resin material such as CFRP as exemplified in the crash box of Patent Document 1 with the aim of reducing the weight of the vehicle body.

  On the other hand, a resin-made crash can such as CFRP has an advantage that it can be made more efficient in terms of costs such as mold costs if it is made common (single) regardless of the type of vehicle.

  However, since the height of the bumper reinforcement relative to the collision object varies depending on the vehicle type, when the collision object collides with the bumper reinforcement, an oblique direction having an angle upward or downward with respect to the axial direction of the crash can depending on the vehicle type. Clash from.

  Specifically, since the vehicle type such as the sports type has a low vehicle height, the height of the bumper reinforcement is lower than the collision body. For this reason, the colliding body collides with the bumper reinforcement from diagonally upward. On the other hand, since the vehicle type such as SUV has a high vehicle height, the height of the bumper reinforcement is higher than that of the collision object. For this reason, the colliding body collides with the bumper reinforcement from diagonally below.

  Then, a load is input to the crash can from such an oblique direction having an angle upward or downward via the bumper reinforcement due to the upward oblique projection or the downward oblique projection. As a result, a bending stress that compresses in the vertical direction acts on the portion between the one end and the other end in the longitudinal direction (vehicle longitudinal direction or axial direction) of the crash can. There is concern that it will not be properly compressed and broken in the direction.

  On the other hand, the thing of the patent document 1 is about the countermeasure with respect to the subject which may bend | fold by the bending stress of the base part (a joint part with a side frame, a base part) of a crash can act by an upward slant or a downward slant. Although mentioned, the part between the root of the crush can and the tip (the joint with the bumper reinforcement) was not mentioned, and there was room for further study.

JP 2009-274663 A

  The present invention has been made in view of such problems, and suppresses bending of the shock absorbing structure against bending stress acting on a portion between the front end and the rear end of the shock absorbing structure due to the upper or lower inclined protrusion. The purpose is to do.

The present invention is formed from a resin material in a substantially U-shape extending in the vehicle longitudinal direction and having an opening extending in the vehicle longitudinal direction on the inside or outside in the vehicle width direction and extending in the vehicle longitudinal direction. in the shock absorbing structure of a vehicle equipped with the frame member, the frame member, together with the cross section perpendicular to the vehicle longitudinal direction is formed in a tapered shape that gradually becomes smaller toward the front of the vehicle, upper and lower opening ends of the opening parts and flange portion protruding in the vertical opposite directions is formed in the longitudinal direction of the vehicle, the connecting portion is provided that partially connects between the upper and lower flanges for the vehicle longitudinal direction, the connecting portion, the Provided only at the center of the frame member in the longitudinal direction of the vehicle, and at the front end of the frame member, the front end extends from the front end toward the open cross-sectional space inside the frame member A flange portion is formed at the rear end of the frame member, and a root side flange portion extending from the rear end to the side opposite to the open section space side is formed. The front end is formed over the entire length in the front-rear direction, the front end is formed continuously with the front end flange portion, and the rear end is formed with the root side flange portion, and the front end flange portion further includes a fastening member. Mounting holes for mounting on the bumper rain side extending in the vehicle width direction, and mounting holes on the front side frame side extending in the vehicle front-rear direction by a fastening member are provided in the root flange portion, respectively. It is.

  According to the above configuration, the frame member is formed so that the cross section orthogonal to the vehicle front-rear direction is substantially U-shaped because it is difficult to form a closed cross-sectional structure for molding. Between the front end and the rear end of the frame member due to a collision (upward oblique projection or downward oblique projection) from an oblique direction having an angle upward or downward with respect to the front end side (front side or rear side) of the vehicle in the longitudinal direction Suppression of bending against bending stress acting on the portion can be realized with a simple configuration.

Further, since the connecting portion is provided only at the center of the frame member in the vehicle front-rear direction, it effectively reinforces the center of the frame member that is most likely to be broken in the vehicle front-rear direction or the vicinity thereof. The frame member can be efficiently prevented from being bent by the connecting portion partially provided in the vehicle front-rear direction.

  The center of the frame member in the vehicle front-rear direction indicates an intermediate position that bisects the length of the frame member in the vehicle front-rear direction (longitudinal direction).

As an aspect of the present invention, a concave curved portion is formed on the side wall portion of the frame member, and a stepped curved portion is formed on each of the upper and lower wall portions of the frame member over the entire length in the front-rear direction of the frame member. It is a thing.

  According to this invention, it is possible to suppress the bending of the shock absorbing structure against the bending stress acting on the portion between the front end and the rear end of the shock absorbing structure due to the upper or lower inclined protrusion.

The external view which shows the principal part of the vehicle front part provided with the impact-absorbing structure of this embodiment. The right view which shows the principal part of the vehicle front part provided with the impact-absorbing structure of this embodiment. FIG. 3 is an enlarged sectional view taken along line AA in FIG. 2. The external view seen from the front and diagonally left upper direction of a frame member. Explanatory drawing (a) which shows the arrangement position of a connection member, The analysis figure (b) which shows the deformation | transformation amount at the time of upward slanting of the crash can when a connection part is L = 0 in (a). The analysis figure which shows the deformation | transformation amount at the time of the collision load input from the front to the crash can when L = 0 in FIG. 5 (a).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the figure, arrow F indicates the front of the vehicle, arrow L indicates the left side of the vehicle (the vehicle width direction outside), arrow R indicates the vehicle right side (the vehicle width direction inside), and arrow U indicates the vehicle upper side. To do. In addition, since the principal part of the vehicle body front part provided with the impact-absorbing structure of this embodiment is a left-right symmetric shape, it demonstrates based on the structure of the vehicle left side except the case where it shows especially below.

  In this embodiment, the shock absorbing structure is provided in the front part of the vehicle body and applied to a crash can 1 made of carbon fiber reinforced resin (hereinafter abbreviated as “CFPR”).

  A pair of left and right front side frames 100 extending in the longitudinal direction of the vehicle are disposed on the left and right sides of the engine room at the front of the vehicle body, and the crash can 1 is attached to the front ends of the front side frames 100 by fastening or the like. A plate 110 is attached.

  Crash cans 1 are attached to the left and right mounting plates 110, respectively, and a bumper reinforcement 120 (hereinafter referred to as "bumper rain 120") extending in the vehicle width direction is provided between the front ends of the left and right crash cans 1. Abbreviated).

  As shown in FIG. 1, the above-described front side frame 100 has a closed cross section that extends in the front-rear direction of the vehicle by joining and fixing upper and lower joint flange portions of the front side frame inner 101 and the front side frame outer 102. It is a strength member.

  Further, as shown in FIGS. 1 and 2, bolt mounting portions 103 are provided at the corners (upper and lower parts on the outer side in the vehicle width direction and upper and lower parts on the inner side in the vehicle width direction) at the front part of the front side frame 100 in the radially outward direction. It is provided to extend to. In addition, illustration of the bolt attachment part 103 of the vehicle width direction inner side lower part is abbreviate | omitted. As shown in FIGS. 2 and 4, mounting holes 103 a are formed through these bolt mounting portions 103 in the vehicle front-rear direction.

  On the other hand, as shown in FIG. 2, a mounting hole 110 a (see FIG. 2) is formed through a portion corresponding to the mounting hole 103 a of the bolt mounting portion 103 in a front view of the mounting plate 110.

  The mounting plate 110 is inserted into the mounting holes 103a and 110a and tightened with nuts in a state in which the mounting plate 110 is in contact with the front end portion of the front side frame 100. It is attached to the front end (see FIGS. 1 and 2).

  On the other hand, as shown in FIGS. 1 and 2, the above-described bumper rain 120 is a member for giving a bumper (not shown) a predetermined strength, and both end portions in the vehicle width direction are respectively connected to the front via the crash cans 1. It is fixed to the side frame 100. The bumper rain 120 extends in the vehicle width direction while gently curving forward, and a closed cross-sectional space 11A is formed therein.

  As shown in FIGS. 1 and 2, the above-described crash can 1 extends in the vehicle front-rear direction, and as shown in FIGS. 1 to 4, the cross-section orthogonal to the vehicle front-rear direction opens to the outside in the vehicle width direction. A frame member 10 formed of CFPR in a substantially U-shape, and a connecting member 20 that connects a pair of upper and lower opening ends 15u and 15d of the frame member 10 as shown in FIGS. Consists of.

  As shown in FIG. 4, the frame member 10 is integrally formed of a frame main body portion 11, an upper flange portion 12 u, a lower flange portion 12 d, a root side flange portion 13, and a distal end side flange portion 14 by molding.

  As shown in FIG. 3, the frame main body 11 includes an upper wall portion 11 a, a lower wall portion 11 b, and a side wall portion 11 c on the inner side in the vehicle width direction connecting the inner ends in the vehicle width direction of these wall portions 11 a and 11 b. An open cross-sectional space 11A that extends in the front-rear direction and opens outward in the vehicle width direction over the entire length in the vehicle front-rear direction is formed. As shown in FIGS. 1, 2, and 4, the frame main body 11 is configured in a tapered shape in which an orthogonal cross section in the vehicle front-rear direction gradually decreases toward the front of the vehicle.

  As shown in FIG. 3, the side wall portion 11c on the inner side in the vehicle width direction is formed with a recessed portion 11c1 that is recessed toward the open section space 11A in the middle portion in the vertical direction over the entire length in the vehicle front-rear direction. On the upper and lower sides of the recessed portion 11c1, bulged portions 11c2 and 11c2 that bulge smoothly toward the opposite side (in the vehicle width direction) of the open section space 11A are formed.

  Then, at the corner portion between the upper wall portion 11a and the side wall portion 11c and at the corner portion between the lower wall portion 11b and the side wall portion 11c, a curved portion 11d curved as a part of the bulging portions 11c2 and 11c2 on the upper and lower sides, respectively. , 11d (see FIG. 3).

  Further, as shown in FIG. 3, the upper wall portion 11a is formed in a shape in which the vehicle width direction outer side protrudes upward through the stepped upper wall curved portion 11e with respect to the vehicle width direction inner side, The lower wall portion 11b is formed in a shape in which the vehicle width direction outer side protrudes downward through a step-shaped lower wall curved portion 11f with respect to the vehicle width direction inner side.

  As shown in FIGS. 1 to 4, the upper flange portion 12 u described above is formed to protrude upward from the upper opening end portion 15 u of the opening portion 15 of the frame main body portion 11, while the lower flange portion 12 d described above is The frame main body 11 is formed so as to protrude downward from the lower opening end 15 d of the opening 15 of the opening 15.

  As shown in FIGS. 2 and 4, the upper and lower flange portions 12 u and 12 d are formed over substantially the entire length of the frame main body portion 11 in the vehicle front-rear direction (longitudinal direction) and the center in the vehicle front-rear direction. In the portion (intermediate position), a rivet hole 16 (16u, 16f) for connecting the connecting member 20 described later is formed penetrating in the vehicle width direction.

  As shown in FIGS. 1, 2, and 4, the above-mentioned root side flange portion 13 (13 u, 13 d) extends from the base side end portion (rear end) of the frame main body portion 11 to the upper and lower sides. Yes.

  As shown in the figure, a plurality of mounting holes 13a are formed through the root flange portions 13u and 13d on the upper and lower sides. On the other hand, as shown in FIG. 2, the mounting plate 110 is located at a portion corresponding to the mounting hole 13a when viewed from the front (rear view of the vehicle) in a state where the upper and lower root flange portions 13u and 13d are in contact with the front surface. A mounting hole 110b is formed through.

  As shown in FIGS. 1 and 2, the frame member 10 provided in the crash can 1 is mounted with bolts in a state where the root side flange portions 13 u and 13 d on the upper and lower sides are in contact with the front surface of the mounting plate 110. By being inserted into the holes 13a and 110b and tightened with nuts, the bolts and nuts are attached from the fastening members Tb.

  As a result, when a bending stress is input to the crash can 1 due to a collision from the front of the vehicle having an angle upward or downward with respect to the vehicle longitudinal direction (hereinafter referred to as “upward oblique projection or downward oblique projection”). In addition, at the root portion of the crash can 1 where the bending stress is maximized, a strength that does not cause bending against the bending stress is secured.

  As shown in FIGS. 1, 2, and 4, the above-described front end flange portion 14 extends outward from the front end (front end) of the frame main body portion 11 in the vehicle width direction.

  As shown in FIGS. 2 and 4, the front end side flange portion 14 is formed with mounting holes 14 a penetratingly on the upper and lower sides thereof. On the other hand, as shown in FIG. 2, the rear wall 121 of the bumper rain 120 has a mounting hole 120 a at a portion corresponding to the mounting hole 14 a in a front view (vehicle rear view) at a contact portion with the front end flange portion 14. It is formed through.

  As shown in FIG. 2, the bumper rain 120 is formed by inserting bolts into the mounting holes 14a and 120a and tightening them with nuts in a state where the front end flange portion 14 of the crash can 1 is in contact with the rear surface 121a. And it is attached to the front-end | tip part of the crash can 1 (frame member 10) with the fastening member Tc which consists of nuts.

  Moreover, as shown in FIGS. 1-3, the connection member 20 mentioned above is a strip-shaped steel plate, The upper end of the upper flange part 12u and the lower end of the lower flange part 12d in the said center part of the flame | frame main-body part 11 and And having a length in the longitudinal direction corresponding to the interval. As shown in FIGS. 2 and 3, the connecting member 20 is arranged in such a manner that the upper and lower flange portions 12u and 12d are connected to each other at the central portion of the frame body portion 11 in the vehicle front-rear direction (longitudinal direction). A rivet hole 21u is formed through the portion corresponding to the rivet hole 16u of the upper flange portion 12u on one end (upper end) side in the longitudinal direction (vertical direction) of the connecting member 20, and in the longitudinal direction (vertical direction). A rivet hole 21d is formed through the portion corresponding to the rivet hole 16d of the lower flange portion 12d on the other end (lower end) side.

  The rivet holes 16u and 21u in the upper portion of the connecting member 20 and the upper flange portion 12u are fastened and joined using rivets R, and the rivet holes 16d and 21d in the lower portion of the connecting member 20 and the lower flange portion 12d are connected to each other. 2 and 3, the connecting member 20 connects the upper and lower flange portions 12u and 12d at the intermediate portion of the frame member 10 in the vehicle front-rear direction. It is arranged.

  That is, the connecting member 20 is substantially in the middle between the front end of the crash can 1 in the vehicle front-rear direction (joint location with the rear surface 121a of the bumper rain 120) and the rear end (joint location with the front surface of the mounting plate 110 of the crash can 1). (Intermediate position).

  As a result, as shown in FIG. 3, the connecting member 20 is disposed in the vertical direction so as to close the opening 15 at the center of the frame member 10 in the vehicle front-rear direction, and is closed by the connecting member 20 and the frame main body 11. By configuring the cross-sectional space 11A, the upper and lower open end portions 15u and 15d are reinforced so as not to be close to each other at the time of upward oblique projection or downward oblique projection.

(simulation)
Here, as shown in FIG. 5 (a), the front and rear of each of the crash cans 1 of the embodiment products 1 to 5 of the present invention prepared according to the difference in the arrangement position of the connecting member 20 in the vehicle longitudinal direction of the frame member 10 Based on the amount of deformation of the frame member 10 and the concentration of stress acting on the frame member 10 when the collision load F is input from the front side while restraining both ends, the connecting member 20 is brought to an intermediate position in the vehicle longitudinal direction of the frame member 10. The effectiveness of the above-described embodiment provided was verified by simulation.

  FIG. 5 (a) shows the arrangement positions (L = 0, 50, 100, −50, −) of the connecting member 20 in the vehicle front-rear direction of the frame member 10 corresponding to the crash cans 1 of the products 1 to 5 of the present invention. 100) indicates [mm]. Note that L = 0 in FIG. 5A indicates an intermediate position between the front end and the rear end of the frame member 10, and the vehicle front from the intermediate position is a positive direction and the vehicle rear is a negative direction. To do.

  5 (a), 6 (a), 6 (b), 6 (c), and 6 (d), each frame member 10 is displayed with a dot in a region where a tensile load or a stress concentration of the compressive load is applied, and the tensile load. Alternatively, dots are displayed densely (darkly) according to the magnitude of the absolute value of the stress concentration of the compressive load. Further, in FIGS. 5A, 6A, 6B, 6C, and 6D, the amount of deformation of the frame member 10 in the vertical direction is emphasized more than the actual amount.

  As is clear from FIGS. 6 (a), (b), (c), and (d), the implementation product 2 (see FIG. 6 (a)) or the implementation product 5 (see FIG. 6 (b)) rather than the implementation product 3 (see FIG. 6 (b)). 6 (see FIG. 6 (d)), the actual product 4 (see FIG. 6 (c)) has an absolute value of the amount of deformation in the vertical direction of the frame member 10 with respect to the front impact load F and the concentration of stress acting on the frame member 10. Overall is suppressed.

  Further, as is clear from FIGS. 5 (a), 6 (a) and 6 (c), the implementation product 1 (see FIG. 5 (a)) or the implementation product 4 rather than the implementation product 2 (see FIG. 6 (b)). The implementation product 1 (see FIG. 5 (a)) has an absolute amount of deformation in the vertical direction of the frame member 10 with respect to the front impact load F and the concentration of stress acting on the frame member 10 rather than (see FIG. 6 (c)). The value is further suppressed.

  As described above, the rigidity of the frame member 10 is efficiently increased by disposing the connecting member 20 at a more intermediate position in the longitudinal direction of the frame member 10 at the time of the front collision. The frame member 10 can be prevented from being bent in the middle, and the frame member 10 can be reliably and sequentially broken from the front end to the rear by suppressing the amount of deformation in the vertical direction, resulting in stable load absorption performance. It was confirmed by simulation that

  On the other hand, since the vertical bending stress is applied to the frame member 10 at the time of the upward oblique projection or the downward oblique projection, the frame member 10 is subjected to the above-described forward collision load F along the longitudinal direction. The absolute value of the stress concentration of the frame member 10 is assumed to be larger, but by adopting the above-described embodiment in which the connecting member 20 is disposed at a more intermediate position in the longitudinal direction of the frame member 10, Since the rigidity of the frame member 10 can be increased efficiently, it is considered that the frame member 10 is also effective against bending stress that acts on the frame member 10 at the time of upward oblique projection or downward oblique projection.

  Thus, the crash can 1 as the vehicle impact absorbing structure of the present embodiment extends substantially in the vehicle front-rear direction, and the cross section perpendicular to the vehicle front-rear direction has the opening 15 that opens to the outside in the vehicle width direction. It consists of a frame member 10 formed of CFPR as a resin material in a letter shape (see FIGS. 1 to 4), and the frame member 10 is an upper flange portion that protrudes upward at an upper opening end portion 15u of the opening portion 15 thereof. 12u and a lower flange portion 12d projecting downward from the lower opening end portion 15d are formed in the vehicle front-rear direction (see the figure), and the upper and lower flange portions 12u, 12d are connected to each other in the vehicle front-rear direction. Is provided with a connecting member 20 as a connecting part to be partially connected (see FIGS. 1 to 3).

  According to the above configuration, the frame member 10 is formed so that the orthogonal cross section in the vehicle front-rear direction is substantially U-shaped because it is difficult to form a closed cross-sectional structure on the molding, but the upper oblique projection Alternatively, the bending of the bending force acting on the portion between the front end and the rear end of the frame member 10 due to the downward oblique projection can be easily suppressed as compared with, for example, a case where the entire vehicle longitudinal direction is formed into a closed cross-sectional structure. It can be realized with a configuration.

  Further, according to the above configuration, since the upper and lower flange portions 12u and 12d are partially connected in the vehicle front-rear direction (longitudinal direction) by the connecting member 20, the opening 15 is completely closed by the connecting member 20 in the vehicle front-rear direction. It will not be done. Therefore, since the fragments of the frame member 10 that are sequentially destroyed at the time of a vehicle collision can be discharged to the outside through the opening 15 without being obstructed by the connecting member 20, they can be accumulated inside the frame member 10. The crush can 1 can be crushed.

  As an aspect of the present invention, the connecting member 20 is provided at the center in the vehicle longitudinal direction of the frame member 10, that is, at an intermediate position (see FIGS. 1 to 3).

  The front and rear end portions of the frame member 10 in the vehicle front-rear direction are firmly joined to the bumper train 120 and the front side frame 100 either directly or indirectly by fastening or the like. On the other hand, the intermediate position of the frame member 10 in the vehicle front-rear direction or the vicinity thereof corresponds to a portion where bending stress is particularly easily applied by the upper or lower oblique projection in the vehicle longitudinal direction of the frame member 10.

  In this respect, since the connecting member 20 is provided at the center (intermediate position) of the frame member 10 in the vehicle front-rear direction in this embodiment, the middle or the vicinity thereof where the frame member 10 is likely to be broken is effective. Thus, the fold can be efficiently suppressed by the connecting member 20 partially provided in the vehicle longitudinal direction of the frame member 10 as described above.

The present invention is not limited to the configuration of the above-described embodiment, and can be formed in various embodiments.
For example, consolidated member 20 is formed of sheet metal, not limited thereto, and may be formed of CFPR-made member.

1 ... Crash can (shock absorbing structure)
10 ... Frame member 12u ... Upper flange part (flange part)
12d ... Lower flange (flange)
15 ... Opening portion 15u ... Upper opening end portion 15d ... Lower opening end portion 20 ... Connection member (connection portion)

Claims (2)

A frame member formed of a resin material in a substantially U-shape extending in the vehicle longitudinal direction and having an opening that extends in the vehicle width direction and having an orthogonal cross section in the vehicle longitudinal direction extending inward or outward in the vehicle width direction. in the shock absorbing structure of a vehicle equipped,
The frame member is formed in a tapered shape in which an orthogonal cross section in the vehicle front-rear direction gradually decreases toward the front of the vehicle , and a flange portion that protrudes in a direction opposite to the upper and lower opening ends of the opening portion is provided in the vehicle. It is formed in the front-rear direction,
A connecting portion that partially connects the upper and lower flange portions with respect to the vehicle longitudinal direction is provided ,
The connecting portion is provided only at the center of the frame member in the vehicle longitudinal direction,
At the front end of the frame member, a front-end flange portion extending from the front end to the open cross-section space side inside the frame member is provided at the rear end of the frame member and from the rear end to the open cross-section space side. Root side flanges extending to the opposite side are respectively formed,
Both the upper and lower flange portions are formed over the entire length of the frame member in the front-rear direction, the front end is formed continuously with the front end side flange portion, and the rear end is formed with the root side flange portion, respectively.
Further, the front end side flange portion has a mounting hole for attachment to the bumper rain side extending in the vehicle width direction by a fastening member in the front end side flange portion, and the front side frame extending in the vehicle front-rear direction by the fastening member in the root side flange portion. A shock absorbing structure for a vehicle provided with a mounting hole on each side . A concave curved portion is formed on the side wall portion of the frame member, and a stepped curved portion is formed on each of the upper and lower wall portions of the frame member over the entire length in the front-rear direction of the frame member. Item 2. The vehicle impact absorbing structure according to Item 1.

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