JP5486251B2 - Vehicle shock absorber and vehicle bumper device - Google Patents

Description

  The present invention relates to a vehicle shock absorber and a vehicle bumper device.

  Conventionally, as an impact absorber for vehicles, what was indicated, for example in patent documents 1 is known. FIGS. 8A and 8B are a plan view and a front view showing such a conventional vehicle shock absorber 80, respectively. As shown in the figure, the shock absorber 80 for a vehicle has an end portion of a bumper inhose 16 extending in the vehicle width direction between the bumper inn hose 16 and the side member 11 extending in the vehicle front-rear direction. Intervened. The vehicle impact absorber 80 is made of an extruded material of an aluminum alloy having a substantially cross-sectional shape of a substantially square shape. For example, when the vehicle is subjected to a compression impact load (axial compression load) in the axial direction of the extrusion due to a vehicle collision. In addition, the impact energy is absorbed by suppressing the Euler buckling and performing axial compression deformation, so-called bellows deformation.

Japanese Patent No. 3520959

  By the way, as shown in FIG. 8A, for example, the vehicle is obliquely projected to the obstacle S, and the vehicle shock absorber 80 is closer to the outside in the vehicle width direction than the axial direction of the vehicle shock absorber 80. It is assumed that the load F is input from the diagonal. That is, it is assumed that the vehicle collides with an obstacle S that is inclined at an angle θ (for example, 10 °) so as to approach the vehicle shock absorber 80 side in the vehicle longitudinal direction as it goes from the inside to the outside in the vehicle width direction. At this time, as shown in FIG. 8 (b), it has been confirmed that the input load on the inner side in the vehicle width direction and the central part in the vehicle width direction increases and the input load on the outer side in the vehicle width direction decreases. In this case, the load applied to the vehicle shock absorber 80 becomes uneven in the vehicle width direction, so that a moment M of force is generated and the side member 11 may be broken.

  An object of the present invention is to provide a shock absorber for a vehicle and a bumper device for a vehicle that can suppress the bending of a side member when a load is input obliquely with respect to the axial direction.

In order to solve the above problems, the invention according to claim 1 is provided such that an end portion of a bumper inhose extending in the vehicle width direction is interposed between the bumper inn hose and a side member extending in the vehicle front-rear direction. In a vehicle impact absorber that absorbs impact energy by absorbing axial compression load by bellows deformation, a cylindrical main body portion that opens in the vehicle front-rear direction and is connected to the main body portion to define the inside of the main body portion. A first rib that forms a first hollow portion and a second hollow portion on the inner side and the outer side in the vehicle width direction, respectively, and the main body portion and the first rib, and the first hollow portion and the second hollow portion Among these, at least the second hollow portion is divided into a plurality of second ribs in the vehicle vertical direction, and the number of hollow portions defined in the first hollow portion is defined in the second hollow portion. Set less than the number of hollow parts , Respectively are formed in the vehicle width direction on both sides of the side wall of the body portion, provided with a stress concentration portion becomes a starting point of the bellows deformation, the stress concentration portion of the vehicle on the side walls of said body portion in accordance with the period of the bellows deform The gist is that they are arranged alternately in the front-rear direction .

  According to this configuration, the number of hollow parts defined in the first hollow part is set to be smaller than the number of hollow parts defined in the second hollow part, so that the axial compression load is reduced. At the time of input, the load can be concentrated on the second hollow portion having a larger number of hollow portions than the first hollow portion, that is, the second hollow portion relatively enhanced by the second rib. Therefore, for example, when a load is input from an oblique side closer to the outer side in the vehicle width direction with respect to the axial direction of the main body portion, such as a vehicle obliquely projecting on an obstacle, the load is concentrated on the second hollow portion, The unevenness between the load applied to the inner side in the vehicle width direction, which tends to increase the input load, that is, the load applied to the first hollow portion can be reduced. And it can suppress that the said side member breaks by the moment of the force which arises by the uneven load added to the said 1st hollow part and the said 2nd hollow part (vehicle width direction inner side and outer side).

Moreover, the stress concentration portions arranged alternately in the vehicle front-rear direction in accordance with the period of the bellows deformation are formed on the both side walls of the main body portion, thereby further stabilizing the load during the bellows deformation. As a result, the impact energy can be absorbed more efficiently.
According to a second aspect of the present invention, in the vehicle impact absorber according to the first aspect, the thickness of the side wall of the main body on the side of the second hollow portion is greater than the thickness of the side wall of the side of the first hollow portion. The gist of this is that it is set larger.

  According to the same configuration, the thickness of the side wall on the second hollow portion side of the main body portion is set to be larger than the thickness of the side wall on the first hollow portion side, so that the second strength is relatively increased. The load can be further concentrated on the hollow portion side.

According to a third aspect of the present invention, in the vehicle impact absorber according to the first or second aspect , the second rib is not connected to a side wall of the main body portion on the first hollow portion side, The number of hollow parts defined in the first hollow part is one, and the stress concentration part formed on the side wall of the main body part on the first hollow part side is the height of the second rib. The main point is that the vehicle extends in the vertical direction of the vehicle without being divided in the vertical direction of the vehicle.

According to this configuration, for example, the structure can be further simplified as compared to a case where a plurality of the stress concentration portions are divided by the height of the second rib in the vehicle vertical direction.
According to a fourth aspect of the present invention, a pair of bumper in hoses extending in the width direction of the vehicle is interposed between the bumper in hoses and the pair of side members extending in the front-rear direction of the vehicle. The vehicle bumper apparatus provided with the crash box WHEREIN: It makes it a summary to provide the shock absorber for vehicles as described in any one of Claims 1-3 as said crash box.

  According to this configuration, it is possible to provide a vehicle bumper device including the crash box that can suppress the side member from being bent when a load is input obliquely with respect to the axial direction.

  According to the present invention, it is possible to provide a vehicle impact absorber and a vehicle bumper device capable of suppressing the bending of the side member when a load is input obliquely with respect to the axial direction.

The top view which shows one Embodiment of this invention. The perspective view which shows the same embodiment. (A) and (b) are front views showing the embodiment and the conventional embodiment, respectively. (A) and (b) are graphs showing the relationship between the amount of deformation and the load that are simulated separately for the inside and outside of the vehicle in each of the embodiment and the conventional embodiment. (A) and (b) are graphs showing the relationship between the amount of deformation and the load that are simulated in the vehicle width direction and the vehicle vertical direction in each of the embodiment and the conventional embodiment. The side view which shows the same embodiment. (A)-(d) is a front view which shows the modification of this invention. (A) and (b) are the top view and front view which show a conventional form.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a vehicle bumper device according to this embodiment applied to a front portion of a vehicle such as an automobile. As shown in the figure, on both sides in the vehicle width direction, a pair of side members 11 made of, for example, a metal plate and having a hollow structure with a substantially square cross section and extending in the vehicle front-rear direction are disposed. These side members 11 constitute a part of the body. Note that a substantially rectangular bracket 12 made of, for example, a metal plate is fixed to the front end of each side member 11 by welding in such a manner as to close the opening of the side member 11.

  The vehicle bumper device includes a crash box 13 as a vehicle shock absorber that is made of, for example, an aluminum alloy extruded material and extends in the vehicle front-rear direction and is attached to the front surface of each bracket 12. The pair of crash boxes 13 absorbs impact energy by absorbing, for example, an axial compression load accompanying a vehicle collision by bellows deformation. And each edge part 16a of the bumper-in hose 16 which consists of a metal plate etc. extended in the vehicle width direction is attached to the front end of each crash box 13. As shown in FIG. Each end 16a of the bumper inhose 16 is inclined so as to go to the rear of the vehicle as it goes outward in the vehicle width direction according to the design of the vehicle, and the front end of each crash box 13 protrudes forward. It is molded into a chevron. More specifically, the front end of the crash box 13 is inclined along the facing surface 16b of the end portion 16a of the bumper inhose 16 from the outside in the vehicle width direction to the inside, and the facing portion 14 that approaches or abuts against the facing surface 16b. The inclined portion 15 is inclined from the inner end of the facing portion 14 so as to be separated from the facing surface 16b of the end portion 16a of the bumper-in hose 16. And the mountain shape is exhibited so that the connection part of the opposing part 14 and the inclination part 15 may become a vertex. Each crush box 13 is fastened to the bumper inn hose 16 in a manner of approaching or abutting against the opposing surface of each inclined end of the bumper inn hose 16 on the outer side in the vehicle width direction of the mountain portion at the front end. .

  FIG. 2 is a perspective view showing the crash box 13, and FIG. 3A is a front view showing the crash box 13. FIG. 3B shows a conventional vehicle shock absorber (crash box) 80 for convenience. As shown in FIG. 2 and FIG. 3A, the crush box 13 has a substantially square cylindrical main body 21 forming its outer shape. That is, the main body 21 includes a pair of side walls 21a and 21b disposed on the inner side and the outer side in the vehicle width direction, and a lid wall 21c and a bottom wall 21d that communicate between the upper and lower edges of the side walls 21a and 21b, respectively. And opens in the vehicle front-rear direction.

  The crash box 13 is connected to the inner wall surface of the lid wall 21c and the bottom wall 21d at the center in the vehicle width direction, defines the inside of the main body portion 21, and the first hollow portion C1 and the second hollow portion respectively on the inner side and the outer side in the vehicle width direction. It has the 1st rib 22 which forms the hollow part C2. Further, the crash box 13 is connected to the inner wall surface of the side wall 21b and the opposing surface of the first rib 22 at the center in the vehicle height direction, and the second hollow portion C2 is divided into a plurality (two) in the vehicle vertical direction. It has the 2nd rib 23 which forms hollow part C3, C4 at the width direction upper side and lower side, respectively. Accordingly, the second hollow portion C2 is composed of both the hollow portions C3 and C4. And the number (one) of the hollow parts (C1) partitioned and formed in the first hollow part C1 is larger than the number (two) of the hollow parts (C3 and C4) partitioned and formed in the second hollow part C2. It is set less. As a result, when an axial compression load is input, the load is concentrated on the second hollow portion C2 having a larger number of hollow portions than the first hollow portion C1, that is, the second hollow portion C2 relatively strengthened by the second ribs 23. Is done.

  The opening area S1 of the first hollow part C1 and the opening area S2 of the second hollow part C2 (opening area (= S3 + S4) obtained by adding the opening areas S3 and S4 of both hollow parts C3 and C4) are substantially the same. Equivalent (S1 = S2) is set. Further, the opening areas S3 and S4 of the hollow portions C3 and C4 are set to be substantially equal to each other (S1 = S2). The plate thicknesses of the one side wall 21a, the lid wall 21c and the bottom wall 21d of the main body 21 are set to be equal to each other, and are set smaller than the plate thickness of the other side wall 21b, and It is set to be larger than the plate thickness of the first and second ribs 22 and 23. Further, the part where the first and second ribs 22 and 23 are connected to the main body part 21, the part where the both ribs 22 and 23 are connected, and the part which forms the corner of the main body part 21 are each formed into a curved shape. Yes. The crash box 13 is integrally formed with the main body 21, the first rib 22, and the second rib 23, and is formed with a substantially constant cross section.

  Next, when a load is input from an oblique side closer to the outside in the vehicle width direction with respect to the axial direction of the crash box 13 (main body portion 21), such as the vehicle obliquely projecting on the obstacle S (see FIG. 8A). The simulation results regarding the relationship between the absorption load and the deformation amount will be described based on FIGS. 4 and 5 in comparison with the conventional vehicle shock absorber 80. In this simulation, the FEM (finite element method) shows the transition when the load is input from the oblique direction nearer the outside in the vehicle width direction with respect to the axial direction of the crash box 13 (or the vehicle shock absorber 80) at the angle θ described above. The numerical value of the corresponding part related to the comparison is obtained as an average value of the entire range.

  FIG. 4 compares the transitions of the vehicle width direction inner side range A1 and the vehicle width direction outer side range A2 when such a load is input. FIG. 4 (a) shows the crash box of the present embodiment. 13 shows the simulation results, and FIG. 4B shows the simulation results of the conventional vehicle impact absorber 80. As shown in FIG. 4B, in the conventional vehicle shock absorber 80, the load at the time of deformation is basically larger in the vehicle inner range A1 than in the vehicle outer range A2. The load difference ΔF between them at the initial stage of deformation is large. On the other hand, in the crash box 13 of the present embodiment, as shown in FIG. 4A, the range A1 on the vehicle inner side is reversed so that the load during deformation becomes smaller than the range A2 on the vehicle outer side. In particular, the load difference ΔF between them at the initial stage of deformation is reduced. That is, in the crash box 13, the unevenness between the loads applied to the first hollow portion C1 and the second hollow portion C2 is alleviated. Therefore, the side member 11 is prevented from being broken by a moment of force generated by an uneven load applied to the first hollow portion C1 and the second hollow portion C2 (inner side and outer side in the vehicle width direction).

  On the other hand, FIG. 5 shows that the crush box 13 and the vehicle shock absorber 80 are divided into nine parts in each of three in the vehicle width direction and in the vehicle height direction. Hereinafter, transition of each of the range A3 of the middle-to-medium range and the range A4 of the adjacent portion (hereinafter also referred to as the inner-middle) of the central portion in the vehicle width direction is compared, and FIG. FIG. 5B shows a simulation result of the crash box 13 of the present embodiment, and FIG. 5B shows a simulation result of the vehicle impact absorber 80 of the conventional form. Since the ranges other than the nine divided ranges A3 and A4 of the crash box 13 and the vehicle shock absorber 80 are changed according to the range A4, the description thereof is omitted. As shown in FIG. 5 (b), in the vehicle impact absorber 80 of the conventional form, the load during deformation is basically larger in the middle-medium range A3 than in the middle-middle range A4. Yes. On the other hand, even in the crash box 13 of the present embodiment, the load at the time of deformation is basically larger in the middle-medium range A3 than in the middle-middle range A4, but compared with the shock absorber 80 for the vehicle. Therefore, the load difference between them is naturally reduced. That is, particularly in the middle-medium range A3, the load and concentration during the deformation of the crash box 13 are suppressed as compared with the conventional shock absorber 80 for vehicles.

  Here, if the input load in the middle-medium range A3 is large, the bracket 12 may be depressed as shown in FIG. 8A. However, as described above, the load at this time can be suppressed. As a result, such depressions are suppressed.

  In FIG. 6, the side view which looked at the crash box 13 from the vehicle outer side is shown. 2 and 6, the side wall 21b of the main body 21 has a plurality of (six) stress-concentrating portions in the shape of grooves extending in the vehicle height direction and projecting into the second hollow portion C2. 26 is formed. These stress concentrating portions 26 are arranged at six locations in three rows of two rows up and down, avoiding the second rib 23, and set so that both the front and rear widths and the inward protruding lengths become smaller as the bracket 12 is approached. Has been.

  On the other hand, on the side wall 21a of the main body 21, a plurality of groove-shaped (disposed to the stress concentration portion 26 in the vehicle front-rear direction, extending in the vehicle height direction and projecting into the first hollow portion C1 ( Two) stress concentration portions 27 are formed. Unlike the stress concentration portion 26, these stress concentration portions 27 are not subject to interference by the second ribs 23, and are thus arranged at two locations in two rows before and after one column. It is to be noted that the stress concentration portion 27 is set so that both the front and rear widths and the protruding length to the outside become smaller as it approaches the bracket 12, similar to the stress concentration portion 26.

The alternate arrangement of the stress concentration portions 26 and 27 in the vehicle front-rear direction is set in accordance with the period of bellows deformation of the crash box 13.
Next, the operation of this embodiment will be described. As shown in FIG. 8, when a load F is input from the oblique side closer to the outer side in the vehicle width direction with respect to the axial direction of the crash box 13 via the bumper-in hose 16, such as a vehicle obliquely projecting on the obstacle S, The crash box 13 receives a compressive load in the axial direction. At this time, as described above, the load at the time of deformation is smaller in the range A1 on the vehicle inner side of the crash box 13 than the range A2 on the outer side of the vehicle, and the load difference ΔF between them is reduced particularly in the initial deformation. Is done. And the nonuniformity between the load added to the 1st hollow part C1 and the 2nd hollow part C2 is relieve | moderated, and it is suppressed that the side member 11 breaks with the moment of the force based on this. In addition, the load and concentration during deformation in the middle-middle range A3 of the crash box 13 are suppressed, and the depression of the bracket 12 is suppressed.

  Further, the crash box 13 that has received the axial compression load concentrates the axial compression load on the stress concentration portions 26 and 27 to induce bellows deformation. At this time, the stress concentrating parts 26 and 27 start bellows deformation from the front side where the front and rear width and the protruding length are large. Since the stress concentration portions 26 and 27 are alternately arranged in the vehicle longitudinal direction in accordance with the period of the bellows deformation, the load at the time of bellows deformation of the crash box 13 can be further stabilized, and more efficiently. Can absorb impact energy.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the number of hollow portions (C1) partitioned and formed in the first hollow portion C1 is set to be smaller than the number of hollow portions (C3 and C4) partitioned and formed in the second hollow portion C2. Therefore, when the axial compression load is input, the second hollow portion C2 having a larger number of hollow portions than the first hollow portion C1, that is, the second hollow portion C2 relatively strengthened by the second rib 23 is formed. The load can be concentrated. Therefore, for example, when a load is input from an oblique side closer to the outer side in the vehicle width direction with respect to the axial direction of the main body portion 21 such as a vehicle obliquely projecting an obstacle, the load is concentrated on the second hollow portion C2, Unevenness between the load applied to the inner side in the vehicle width direction, which tends to increase the input load, that is, the load applied to the first hollow portion C1 can be reduced. And it can suppress that the side member 11 breaks by the moment of the force which arises by the non-uniform load added to the 1st hollow part C1 and the 2nd hollow part C2 (vehicle width direction inner side and outer side).

  (2) In the present embodiment, the plate thickness of the side wall 21b on the second hollow portion C2 side of the main body portion 21 is set larger than the plate thickness of the side wall 21a on the first hollow portion C1 side, which is relatively enhanced. Further, the load can be further concentrated on the second hollow portion C2 side.

  (3) In the present embodiment, the stress concentration portions 27 and 26 that are alternately arranged in the vehicle front-rear direction in accordance with the period of the bellows deformation are formed on the side walls 21 a and 21 b of the main body portion 21. The load at the time of bellows deformation can be further stabilized, and as a result, impact energy can be absorbed more efficiently. Since the first hollow portion is not divided by the second rib 23, the stress concentration portion 27 that protrudes outward from the vehicle inner wall can be disposed vertically. As a result, compared with the case where the stress concentration portion 27 is divided into two, the load can be concentrated by the stress concentration portion 27 and the crash box 13 can be easily shifted to bellows deformation, so that the absorption of impact energy is promoted. Can do.

  (4) In this embodiment, the stress concentration portion 27 formed on the side wall 21a on the first hollow portion C1 side of the main body portion 21 is not vertically divided by the height of the second rib 23 in the vehicle vertical direction. By extending in the direction, for example, the structure can be further simplified as compared to the case where a plurality of stress concentration portions 27 are formed by dividing the stress concentration portion 27 in the vehicle vertical direction at the height of the second rib 23.

  (5) In this embodiment, the load and concentration during deformation of the middle-middle range A3 (intersection of the first and second ribs 22 and 23) of the crash box 13 are suppressed, and the depression of the bracket 12 is suppressed. can do.

  (6) In the present embodiment, it is possible to provide a vehicle bumper device including a crash box 13 that can suppress the bending of the side member 11 when a load is input obliquely with respect to the axial direction.

In addition, you may change the said embodiment as follows.
-As shown in Fig.7 (a), even if it has the rib 30 which protrudes in the 1st hollow part C1, following the surface which the 2nd rib 23 spreads in the range which does not reach the side wall 21a of the main-body part 21 Good.

  -As shown in FIG.7 (b), the rib 31 which partitions and forms the 1st hollow part C1 divided and formed by the 1st rib 22 into two hollow parts C11 and C12, and the 2nd hollow part C2 are three hollow It may be a crush box 35 having ribs 32 and 33 which are partitioned into portions C13, C14 and C15. In short, what is necessary is just to set so that the number of the hollow parts which divide and form the 2nd hollow part C2 may be larger than the number of the hollow parts which divide and form the 1st hollow part C1.

  -As shown in FIG.7 (c), the crash box 40 which has the main-body part 41 which chamfered the corner | angular part of the vehicle width direction outer side so that hollow part C21, C22 which forms a 2nd hollow part may become a pentagon. It may be. Thus, by diversifying the second hollow portion side, the axial compression load can be applied to the second hollow portion larger than the first hollow portion.

-As shown in Drawing 7 (d), even if it has rib 30 which protrudes in the 1st hollow part C1 following the field which the 2nd rib 23 spreads in the range which does not reach side wall 21a of main part 41 Good.
-In the said embodiment, the stress concentration part penetrated in the plate | board thickness direction of side wall 21a, 21b may be sufficient.

The shock absorber according to the present invention may be applied to other shock absorbing frames such as the side member 11.
The present invention may be applied to the rear portion of the vehicle.

C1 ... 1st hollow part, C2 ... 2nd hollow part, C3, C4, C11, C12, C13, C14, C15, C21, C22 ... Hollow part, 11 ... Side member, 13, 35, 40 ... Crash box, 16 ... Bumper Inn Hose, 21, 41 ... Main Body, 21a, 21b ... Side Wall, 22 ... First Rib, 23 ... Second Rib, 26, 27 ... Stress Concentration Part.

Claims (4)

A vehicle that is interposed between the bumper-in hose and a side member extending in the vehicle front-rear direction at the end of the bumper-in hose extending in the vehicle width direction and absorbs impact energy by absorbing the axial compression load by bellows deformation. For shock absorbers,
A cylindrical main body that opens in the longitudinal direction of the vehicle;
A first rib connected to the main body and defining a first hollow portion and a second hollow portion on the inner side and the outer side in the vehicle width direction by dividing the main body portion;
A second rib that is connected to the main body portion and the first rib and divides at least the second hollow portion into a plurality in the vehicle vertical direction among the first hollow portion and the second hollow portion;
The number of hollow parts defined in the first hollow part is set to be smaller than the number of hollow parts defined in the second hollow part,
Formed on each side wall of the main body in the vehicle width direction, each having a stress concentration portion serving as a starting point for bellows deformation;
The said impact concentration part is arrange | positioned by turns in the vehicle front-back direction at the said both side walls of the said main body part according to the period of a bellows deformation, The impact absorber for vehicles characterized by the above-mentioned. The vehicle impact absorber according to claim 1,
A vehicle impact absorber, wherein a thickness of a side wall of the main body on the side of the second hollow portion is set to be larger than a thickness of a side wall of the side of the first hollow portion. The vehicle impact absorber according to claim 1 or 2 ,
The second rib is not connected to the side wall of the main body portion on the first hollow portion side, and the number of hollow portions defined and formed in the first hollow portion is one,
The stress concentration portion formed on the side wall on the first hollow portion side of the main body portion extends in the vehicle vertical direction without being divided in the vehicle vertical direction at the height of the second rib. A shock absorber for vehicles. Bumper device for vehicle comprising a pair of crash boxes respectively interposed between the bumper inhose and a pair of side members extending in the front-rear direction of the vehicle at both ends of the bumper inhose extending in the width direction of the vehicle In
A vehicular bumper device comprising the vehicular shock absorber according to any one of claims 1 to 3 as the crash box.

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