JP5130878B2 - Shock absorbing structure - Google Patents

Description

  The present invention relates to an impact absorbing structure disposed between a bumper reinforcement and a front side member.

Conventionally, a shock-absorbing structure having a truncated cone-shaped hollow body made of a fiber composite material is known (see, for example, Patent Document 1). The hollow body constituting the shock absorbing structure has a configuration in which the cross-sectional shape expands from one end to the other end and the thickness increases stepwise or continuously.
JP 2003-262246 A

  Here, in the automobile, in order to absorb the impact of the bumper reinforcement, when the hollow body is disposed between the bumper reinforcement and the front side member, the connecting portion between the bumper reinforcement and the hollow body is: If the front side member and the hollow body are larger than the connecting portion, the other end side having a large thickness and a large cross-sectional shape is connected to the bumper reinforcement, and the thickness of the hollow body is increased. One end side that is thin and has a small cross-sectional shape is connected to the front side member. With such a configuration, the front side member side that is thin and has a small cross-sectional shape is likely to bend and deform. The impact absorption efficiency at the time of collision will be reduced.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an impact absorbing structure capable of improving the impact absorption efficiency.

  The shock absorbing structure according to the present invention has an annular cross section and extends in the front-rear direction, and includes a hollow body having a front end connected to a bumper reinforcement and a rear end connected to a front side member. In the absorbent structure, the cross-sectional shape of the hollow body decreases from the front end to the rear end, and the thickness of the hollow body increases from the front end to the rear end.

  According to such a shock absorbing structure, the cross-sectional shape of the hollow body is reduced from the front end on the bumper reinforcement side toward the rear end on the front side member side, while the thickness of the hollow body is Since it increases from the front end toward the rear end, it is possible to increase the cross-sectional area on the rear end side where bending deformation is likely to occur and reduce the cross-sectional area difference between the front end side and the rear end side. As described above, it is possible to prevent bending deformation on the front side member side, thereby improving impact absorption efficiency.

  Here, it is preferable to have a connecting portion that connects the rear end side of the hollow body and the front side member, and a bead having a ridge line directed to the connecting portion is provided on the peripheral surface of the hollow body. With such a structure, it is possible to transmit the impact from the bumper reinforcement on the front end side to the connecting part with the front side member along the ridge line of the bead while suppressing the out-of-plane deformation of the peripheral surface of the hollow body. The impact can be efficiently transmitted to the front side member.

  According to the shock absorbing structure according to the present invention, it is possible to improve the shock absorption efficiency.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an impact absorbing structure according to the invention will be described with reference to the accompanying drawings. In this specification, the forward direction when the vehicle is moving forward is defined as “front”, and terms such as “front”, “rear”, “left”, and “right” are used.

[First Embodiment]
1 is a perspective view showing an impact absorbing structure according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is an impact absorbing structure shown in FIG. It is a side view of a body. As shown in FIGS. 1 to 3, the shock absorbing structure 1 according to the first embodiment is disposed between the bumper reinforcement 2 and the front side member 3, and from the bumper reinforcement 2 at the time of a vehicle collision. It functions as a so-called crash box that absorbs the shock and efficiently transmits it to the front side member 3.

  The bumper reinforcement 2 is a rectangular hollow member that receives an impact from the front, and extends in the vehicle width direction on the front side of the vehicle.

  The front side member 3 constitutes a skeleton member of the vehicle body, and is a pair of rectangular hollow members disposed on both sides in the vehicle width direction with an engine (not shown) interposed therebetween and extending in the front-rear direction. The vertical width of the front side member 3 is smaller than the vertical width of the bumper reinforcement 2, and the front end of the front side member 3 is connected to the bumper reinforcement 2 via the shock absorbing structure 1. The In the figure, only one front side member is shown.

  The shock absorbing structure 1 has a hollow body 4 having a rectangular annular cross-sectional shape and extending in the front-rear direction, its front end 4a is connected to the bumper reinforcement 2, and its rear end 4b is front It is connected to the side member 3. Specifically, the hollow body 4 has a rectangular cross-sectional shape that continuously decreases from the front end to the rear end, and a thickness that continuously increases from the front end to the rear end. Constructed (excluding the front end 4a and the rear end 4b). In addition, it is also possible to comprise so that the cross-sectional shape of the front-end part 4a and the rear-end part 4b may be reduced continuously from the front side toward the rear side. Moreover, it is also possible to comprise so that the thickness of the front-end part 4a and the rear-end part 4b may increase continuously from the front side toward the rear side.

  The front end 4a of the hollow body 4 has a rectangular box-shaped bracket whose inner peripheral surface has a vertical width substantially the same as the vertical width of the bumper reinforcement 2 and is connected to the rear surface 2a of the bumper reinforcement 2 It arrange | positions so that the outer peripheral surface of 6 may be covered, and is connected with respect to the outer peripheral surface of the bracket 6 by welding.

  The rear end portion 4b of the hollow body 4 is inserted into the front end portion of the front side member 3, and is connected to the front side member 3 via connecting portions 7A and 7B such as bolts.

  A plurality of beads 8 extending toward the connecting portions 7A and 7B are provided on the peripheral surface 4c of the hollow body 4. And these beads 8 are arrange | positioned so that the ridgeline 8a of the longitudinal direction may face the connection part 7A, 7B. Specifically, the upper bead 8 shown in FIG. 1 is arranged such that its ridge line 8a is directed to the connecting portion 7A, and the lower bead 8 is shown so that its ridge line 8a is directed to the connecting portion 7B. .

  According to the shock absorbing structure 1 configured as described above, the cross-sectional shape of the hollow body 4 is continuously reduced from the bumper reinforcement 2 side toward the front side member 3 side. Since the wall thickness continuously increases from the bumper reinforcement 2 side toward the front side member 3 side, the cross-sectional area at the rear end side where bending deformation easily occurs is increased, and the front end side and the rear end are increased. The cross-sectional area difference on the end side is reduced. As a result, as shown in FIG. 4A, when an impact is applied to the bumper reinforcement 2 from the front due to a vehicle collision, the hollow body 4 is stably buckled as shown in FIG. 4B. Can be deformed, and bending deformation on the side of the front side member 3 can be prevented, whereby the impact absorption efficiency can be improved.

  Further, since the peripheral surface 4c of the hollow body 4 is provided with a bead 8 having a ridge line 8a directed to the connecting portions 7A and 7B, as shown in FIG. 3, the outer surface of the peripheral surface 4c of the hollow body 4 is out of plane. While suppressing deformation, the impact from the bumper reinforcement 2 on the front end side can be transmitted to the connecting portions 7A and 7B along the ridge line 8a of the bead 8, and the impact can be efficiently transmitted to the front side member 3. be able to.

[Second Embodiment]
FIG. 5 is a cross-sectional view of the shock absorbing structure according to the second embodiment of the present invention. The shock absorbing structure 11 of the second embodiment is different from the shock absorbing structure 1 of the first embodiment in that its cross-sectional shape gradually decreases from the front end to the rear end, This is a point using a hollow body 14 whose thickness increases stepwise as the cross-sectional shape changes from the front end to the rear end.

  Specifically, the hollow body 14 is formed by connecting a plurality of rectangular cross-sectional shapes having a predetermined length in the front-rear direction and different outer diameters and thicknesses in the front-rear direction.

  Needless to say, even if configured in this manner, the same operations and effects as those of the first embodiment can be obtained.

[Third Embodiment]
FIG. 6 is a cross-sectional view of the shock absorbing structure according to the third embodiment of the present invention. The shock absorbing structure 21 of the third embodiment is different from the shock absorbing structure 1 of the first embodiment in that the outer diameter change is the same as that of the shock absorbing structure 1, but the thickness is the same. This is a point using a hollow body 24 that increases stepwise from the front end to the rear end.

  Needless to say, even if configured in this manner, the same operations and effects as those of the first embodiment can be obtained.

  As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the rear end side of the hollow body, the front side member, However, the connection may be performed by spot welding or the like.

It is a perspective view which shows the impact-absorbing structure which concerns on the 1st Embodiment of this invention. It is sectional drawing which follows the II-II line of FIG. It is a side view of the impact-absorbing structure shown in FIG. It is sectional drawing which shows the impact-absorbing structure when an impact is applied from the front, (a) is a figure which shows the mode before a deformation | transformation, (b) is a figure which shows the mode after a deformation | transformation. It is sectional drawing which shows the impact-absorbing structure which concerns on the 2nd Embodiment of this invention, (a) is a figure which shows the mode before a deformation | transformation, (b) is a figure which shows the state after a deformation | transformation. It is sectional drawing which shows the impact-absorbing structure which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11,21 ... Shock absorption structure, 2 ... Bumper reinforcement, 3 ... Front side member, 4, 14, 24 ... Hollow body, 4c ... Circumferential surface, 7 ... Connection part, 8 ... Bead, 8a ... Ridge line .

Claims (2)

In the shock absorbing structure having a hollow body having an annular cross section and extending in the front-rear direction, the front end side being connected to the bumper reinforcement and the rear end side being connected to the front side member,
The cross-sectional shape of the hollow body is reduced from the front end toward the rear end,
The shock absorbing structure according to claim 1, wherein the thickness of the hollow body increases from the front end toward the rear end so as to reduce a difference in cross-sectional area between the front end side and the rear end side . A connecting portion that connects the rear end side of the hollow body and the front side member;
The shock absorbing structure according to claim 1, wherein a bead having a ridge line directed to the connecting portion is provided on a peripheral surface of the hollow body.

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