JP2011126412A - Impact absorption member for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorption member for a vehicle that has high impact absorbability and is reduced in weight, cost, and space. <P>SOLUTION: The impact absorption member for the vehicle includes a cylindrical body, a tip end flange part integrally formed at an end of the body, and a pedestal part integrally formed at the other end of the body. Circumscribed circles of the tip end flange part and the pedestal part are larger than a peripheral circumscribed circle of the body. The pedestal part has an opening portion for allowing the body to deform inside out by turning. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an impact absorbing member that absorbs an impact at the time of a vehicle collision, and is effectively attached between a front bumper member and a side member member of the vehicle.

In the field of vehicles such as automobiles, it goes without saying that high collision safety is required, but weight reduction is required from the viewpoint of improving fuel efficiency, and ease of repair in the case of a light collision accident is also required. Yes.
Therefore, in recent years, an impact absorbing member such as a crash box has been provided between the front or rear end of the side member, which is a vehicle structural member extending in the longitudinal direction of the vehicle, and a bumper member (bumper reinforcement, bumper beam). It is coming to be able to be attached.

Examples of the crash box include Patent Documents 1 to 3 and the like.
Patent Document 1 discloses a structure that can weld a flange part well even if the main body is thin, and Patent Document 2 also employs a welding process, but the welding method takes man-hours, and there is a problem of strength reduction due to thermal effects, etc. It becomes.
Patent Document 2 discloses an example in which a vertical bead that is easy to buckle and is provided in the front half of the main body and a horizontal bead that is provided in the latter half of the body is disclosed. Since the remaining length is large and the impact absorbing member has a long overall length, there is a problem that a mounting space for the vehicle is widened.
Patent Document 3 discloses an impact absorbing member in which both attachment portions and main body portions are integrally formed by forging aluminum, but only one of the attachment portions at both ends has a flange portion and the other is a cylindrical shape. Therefore, the projecting part for attachment is required for the mating member, and not only is the fastening operation using the bolt difficult, but there is a problem similar to that of Patent Document 2 in that buckling deformation is assumed.

JP 2008-18792 A JP 2009-61845 A Japanese Patent Laid-Open No. 2005-1462

  An object of the present invention is to provide a shock absorbing member for a vehicle having high shock absorbing performance, which is reduced in weight, cost and space.

A vehicle impact absorbing member according to the present invention includes a cylindrical main body, a tip flange formed integrally with one of the main bodies, and a pedestal formed integrally with the other of the main bodies. The circumscribed circle of the front flange portion and the pedestal portion is larger than the circumscribed circle around the main body portion, and the pedestal portion has an opening for turning and reversing the main body portion.
Here, when an end flange portion is provided on one side of the cylindrical main body portion and a pedestal portion is provided on the other side and an opening portion is provided on the pedestal portion, the cylindrical main body portion is turned when an impact is applied to the front end flange portion. Since it protrudes rearward from the opening of the pedestal part while bending in the deformation mode, there is little crushing residue in the case of a heavy collision, and the overall length can be shortened compared to the conventional buckling mode.

In such a turning deformation mode, it is ideal for the displacement-load curve (FS diagram) to be rectangular in order to achieve high and stable energy absorption. The cylindrical shape is preferably substantially the same cross-sectional shape standing vertically from the pedestal portion side toward the tip flange portion side.
In addition, when the main body part is deformed by turning, the connecting part between the main body part and the pedestal part has an R shape that has been changed so that the outer shape becomes larger toward the pedestal part side. preferable.

In the present invention, it is preferable that a welding process is not required and the fitting connection and the bolt fastening can be performed. The tip flange portion and the pedestal portion have a connection portion or an attachment hole, and the connection portion and the attachment hole are with respect to the central axis of the main body portion. It is preferable to be positioned outside the outer peripheral portion of the main body in the orthogonal direction.
In order to reduce the weight, the tip flange portion has a plurality of connecting portions or mounting holes around the circumference, and the outer peripheral shape of the tip flange portion is outside the plurality of connecting portions or mounting holes. It is preferable to have a lightening portion that enters the inside of the rectangular outline connected by a straight line.
Here, the expression "rectangular outline" refers to a rectangular shape in which, for example, when a pair of linear fitting connection portions are provided facing each other, the outside of the facing connection portions is surrounded by a straight line, and the mounting holes are 3 In the case where two or more are provided, it means a hollow portion that enters the inside of a rectangular outline such as a triangle, quadrangle,... Surrounding the outside of the mounting hole.

  The impact absorbing member according to the present invention is effectively attached to a part that is easily subjected to an impact at the time of a vehicle collision, and the tip flange portion is fastened to the bumper member and the pedestal portion is used as a crash box when fastened to the side member member side. it can.

In the present invention, it has a tip flange part and a pedestal on both sides of the main body part, and since the opening part is provided in the pedestal part, it is possible to adopt shock absorption characteristics by the turning deformation mode, and the overall length is shorter and higher than the conventional one. Energy absorption can be obtained.
In addition, the mounting parts on both sides of the main body have a flange shape that protrudes outward around the periphery of the main body, making it easier to prevent the main body from falling sideways. Also, the size of the side member of the vehicle and the bumper member This can be done simply by changing the shape of the pedestal part and the tip flange part and the pitch of the mounting holes in accordance with the shape and size.

The external view of the impact-absorbing member 10 for vehicles which concerns on this invention is shown, (a) is the perspective view seen from the front-end | tip flange part side, (b) is the perspective view seen from the base part side. The impact absorbing member 10 is shown, (a) is a plan view, (b) is a front view, (c) is a bottom view, (d) is a side view, and (e) is a cross-sectional view taken along line AA. The deformation | transformation when an impact is added to an impact-absorbing member is shown typically. The example of the FS diagram of an impact-absorbing member is shown. The manufacture example of an impact-absorbing member is shown. The external appearance perspective view of the impact-absorbing member 20 which concerns on another Example is shown. The top view (b), the side view (a), the front view (c), and the BB line sectional view (d) of the shock absorbing member 20 are shown.

Hereinafter, an example in which the vehicle impact absorbing member 10 according to the present invention is applied to a crash box will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the impact absorbing member 10 includes a cylindrical main body portion 11, a tip flange portion 13 as a bumper member attachment portion, and a pedestal portion 12 as an attachment portion to the tip portion of the side member member. The main body part 11, the tip flange part 13 and the pedestal part 12 are integrally formed by forging aluminum or the like.

The main body 11 has a cylindrical shape having a hollow portion 11a as shown in the cross-sectional view along line AA in FIG. 2 (e), and has substantially the same cross-sectional shape standing vertically from the pedestal portion 12. .
In the present embodiment, the main body 11 has a cylindrical shape, but is not limited thereto, and may be, for example, an elliptical shape.
Here, the expression “substantially the same cross-sectional shape” means that there is substantially no change in thickness along the direction of the central axis of the main body, and it is uniform.

The tip flange portion 13 has an attachment hole 13a for attachment to a bumper reinforcement (bumper beam) or the like of a bumper member.
In this embodiment, an example with four mounting holes is shown, but the number is not limited.
Further, as shown in FIG. 2D, the front end flange portion 13 is also inclined according to the shape of the mounting portion of the bumper member.
Although the center part of the front-end | tip flange part 13 may be opened, it is good to close from a viewpoint of the attachment strength improvement, and in that case, as shown in FIG. It is better to reduce the weight.
The outer shape of the main body 11 is not only provided with a mounting hole 13a at a portion located outside the outer peripheral portion, but also enters the inner side of a rectangular outer shape line connecting the outer sides of the four mounting holes 13a with a straight line (indentation) That is, the lightening portion 13c is formed and the so-called starfish shape is adopted to reduce the weight.

The pedestal portion 12 has a flange-like outer shape protruding in a plate shape on the outside of the main body portion 11 and has an attachment hole 12a with a side member member.
Similarly to the tip flange portion 13, the pedestal portion 12 has a substantially elliptical shape in plan view that is net-shaped in consideration of attachment strength.
As shown in FIG. 2E, the pedestal portion 12 has an opening 12 b whose inner diameter is larger than the outer shape of the main body 11 so that the main body 11 can be deformed while turning.
Further, the connecting portion 14 between the main body portion 11 and the pedestal portion 12 has an R shape with an outer shape spreading toward the pedestal portion 12 side.
By making this part into an R shape, the main body is prevented from falling sideways in the initial stage of shock absorption.
Here, with respect to the thickness t = 1.5 to 4.5 mm of the main body portion 11, the thickness from the connecting portion 14 to the pedestal portion may be constant or changed so as to gradually increase.
In this case, the connecting portion 14 preferably has a range of R = 1.5 to 12 mm.

A deformation mode when a load is applied to the shock absorbing member 10 according to the present invention is schematically shown in FIG.
When the load F is applied to the distal end flange portion 13, the side wall of the main body portion 11 is deformed while turning so that the bent portion 11b proceeds in the direction of the arrow S.
An example of the FS diagram evaluated by the test is shown in FIG.
In this sample, the thickness t of the main body is t = 3.4 mm.
In the present embodiment, the side wall of the main body 11 has a constant thickness in the central axis direction and has substantially the same cross-sectional shape, and thus has a rectangular FS diagram.
Further, since the bent portion 11b enters the inside of the side member member, the bent portion 11b is deformed until the leading end flange portion 13 abuts against the pedestal portion 12, so that the main body portion 11 hardly crushes.

Next, a manufacturing example of the impact absorbing member 10 according to the present invention will be described with reference to FIG.
As shown in FIG. 5A, the molds 32a and 32b are brought into contact with each other, an aluminum material is put into the cavity, and the punch 31 is pressed to perform forging.
Next, the punch 31 is pulled out, and the mold is opened as shown in FIG.
When a draft for extracting the punch 31 is required, the cutting allowance a is cut so that the thickness of the side wall 11b of the main body 11 is constant as shown in FIG.
The manufacturing method is not limited to this.

6 and 7 show another embodiment.
The shock absorbing member 20 in this embodiment has a pedestal portion 22 via an R-shaped connecting portion 24 on one side of a main body portion 21 having a deformed cross section whose side portion has entered inside, and a distal end flange portion 23 on the other side.
The pedestal portion 22 has a mounting hole 22a, but the distal end flange portion 23 has a pair of fitting connection portions 23a protruding outward, and the fitting connection portions 23a are provided in the rail groove in the longitudinal direction of the bumper reinforcement. This is an example of fitting and connecting.
Also in this case, it has the hollow part 23c which entered inside rather than the rectangular outline (square) which enclosed the outer side of a pair of connection part 23a.
In the case of the present embodiment, the center portion of the tip flange portion 23 has an open hole portion 23b.

DESCRIPTION OF SYMBOLS 10 Shock absorption member 11 Main-body part 12 Base part 12b Opening part 13 Tip flange part 14 Joint part 31 Punch 32a, 32b Die a Cutting allowance

Claims (6)

A cylindrical main body, a tip flange formed integrally with one of the main bodies, and a pedestal formed integrally with the other of the main bodies,
The circumscribed circle of the tip flange and pedestal is larger than the circumscribed circle around the body,
The shock absorber for a vehicle, wherein the pedestal portion has an opening for turning the main body portion by turning deformation.   The impact absorbing member for a vehicle according to claim 1, wherein the cylindrical shape of the main body portion is substantially the same cross-sectional shape standing vertically from the pedestal portion side toward the tip flange portion side.   3. The impact absorbing member for a vehicle according to claim 1, wherein a connecting portion between the main body portion and the pedestal portion has an R shape that is modified so that the outer shape becomes larger toward the pedestal portion side. The front flange part and the pedestal part have a connecting part or a mounting hole,
The vehicular impact absorbing member according to any one of claims 1 to 3, wherein the connecting portion or the mounting hole is located outside the outer peripheral portion of the main body portion in a direction orthogonal to the central axis of the main body portion.   The front end flange portion has a plurality of connecting portions or mounting holes around the periphery, and the outer peripheral shape of the front end flange portion is inside the rectangular outer shape line connecting the outsides of the plurality of connecting portions or mounting holes with straight lines. The impact absorbing member for a vehicle according to claim 4, further comprising a hollow portion that has entered.   The crash box using the shock absorbing member for a vehicle according to any one of claims 1 to 5, wherein the front end flange portion is fastened to the bumper member and the pedestal portion is fastened to the side member member side.

Images