JP4341014B2 - Bumper structure for automobile - Google Patents

Description

  The present invention relates to an automobile bumper structure improved for protecting a pedestrian leg.

There has been proposed an energy absorption structure for improving the pedestrian's leg protection performance when a pedestrian inputs to the vehicle (see Patent Document 1). Further, in the structure 81 as shown in FIGS. 9 and 10, the absorbent member 83 having a U-shaped or U-shaped cross section is arranged on the front side of the bumper member 82 in the vehicle width direction.
JP 2001-088634 A

However, the conventional absorption structure 81 does not have an efficient energy absorption characteristic because the load deformation characteristic when crushed in the vehicle length direction L has a large drop after the first peak. Here, the efficient energy absorption characteristic means that more energy can be absorbed with a short stroke (deformation amount).
This invention is made | formed in view of this condition, and it aims at providing the bumper structure for motor vehicles which has an efficient energy absorption characteristic.

The present invention provides an automobile bumper structure in which an energy absorbing member is provided on an outer surface of a bumper member that extends in the vehicle width direction and is attached to a vehicle. A second energy absorbing member having a substantially U-shaped cross section is disposed between the bumper member and the first energy absorbing member so as to open to the bumper member side, and a substantially U-shaped bottom portion of the first energy absorbing member. And a substantially U-shaped bottom portion of the second energy absorbing member and the bumper member are spaced apart from each other in the vehicle front-rear direction, the first energy absorbing member is joined to the bumper member, and the bumper member is The second energy absorbing member is joined .
Also, the present invention comprises an upper Symbol substantially form a flat portion extending in the vertical direction of the vehicle in cross-section the distal end of the bumper member, said second substantially receiving surface extending in parallel with the substantially flat portion with spaced with the symbolic flat portion The second energy absorbing member is formed on an energy absorbing member, and the second energy absorbing member has fixing portions on the upper and lower portions of the bumper member, and the upper fixing portion is arranged on the base end side of the cross section of the bumper member from the lower fixing portion . .

The present invention covers the outer surface of the bumper member with a first energy absorbing member having a substantially U-shaped cross section, and a second energy absorbing member having a substantially U-shaped cross section between the bumper member and the first energy absorbing member. The bumper member has an opening on the side of the bumper member. The substantially U-shaped bottom portion of the first energy absorbing member, the substantially U-shaped bottom portion of the second energy absorbing member, and the bumper member are arranged in the vehicle longitudinal direction. Since the first energy absorbing member is bonded to the bumper member and the second energy absorbing member is bonded to the bumper member, the absorption load is prevented from falling after the peak of the input load, and the absorption characteristics Can be leveled, and efficient energy absorption characteristics can be provided .
Also, the present invention comprises an upper Symbol substantially form a flat portion extending in the vertical direction of the vehicle in cross-section the distal end of the bumper member, said second substantially receiving surface extending in parallel with the substantially flat portion with spaced with the symbolic flat portion The second energy absorbing member is formed on an energy absorbing member, and the second energy absorbing member has fixing portions on the upper and lower portions of the bumper member, and the upper fixing portion is arranged on the base end side of the cross section of the bumper member from the lower fixing portion . Therefore , it is possible to prevent the absorption load from dropping after the peak of the input load, level the absorption characteristics, and provide efficient energy absorption characteristics. Moreover, it is possible to prevent the pedestrian from moving while securing a sufficient strength against energy input by the pedestrian to the vehicle.

Next, an embodiment of a bumper structure for an automobile according to the present invention will be described based on the drawings.
A bumper structure for an automobile according to an embodiment of the present invention is shown in a cross-sectional view in FIG. As shown in the figure, the front bumper member 1 has a substantially U-shaped cross section and opens on the vehicle side (right side in the figure). The front bumper member 1 is formed with flange portions 1b and 1c at each end in the vehicle vertical direction, that is, at the base end side 1a in the cross section. A first absorbent member 2 and a second absorbent member 3 are provided on the front side of the front bumper member 1 in the vehicle front-rear direction L (left side in the figure). The first absorbent member 2 has a substantially U-shaped cross section and is disposed so as to open toward the front bumper member 1 and covers the outer surface 1 d of the front bumper member 1. The second absorbent member 3 is disposed between the first absorbent member 2 and the front bumper member 1. The second absorbent member 3 also has a substantially U-shaped cross section and opens to the front bumper member 1 side.
Flange portions 2 b and 2 c are formed at each end 2 a of the first absorbent member 2 in the vehicle vertical direction, and the flange portions 2 b and 2 c are joined to the flange portions 1 b and 1 c of the front bumper member 1. That is, the first absorbing member 2 is joined to the flange portions 1 b and 1 c on the side of the cross-sectional base end 1 a of the front bumper member 1. Further, the second absorbing member 3 is joined to the front end side 1 e of the cross section of the front bumper member 1. The 1st absorption member 2 and the 2nd absorption member 3 are not mutually joined, but are mutually spaced apart.
The front bumper member 1 is attached to the front portion (not shown) of the vehicle by a known means.

In the present embodiment, as described above, the first absorbent member 2 and the second absorbent member 3 are joined to the front bumper member 1 to form a two-stage absorbent structure, thereby controlling the load-deformation characteristics. is there. As shown in FIGS. 2 and 3, when energy is input to the vehicle by a pedestrian, the first absorbing member 2 is first deformed and then the second absorbing member 3 starts to deform. When the absorption load of the first absorbing member 2 reaches the peak, there is a general tendency that the first absorbing member 2 falls greatly thereafter. However, after the peak of the first absorbing member 2, the load is absorbed by the second absorbing member 3. Compared to the conventional case indicated by the one-dot chain line 4a in FIG. 4, in the case of the present embodiment indicated by the solid line 4b, the dip after the peak can be reduced. 4 is the time of deformation shown in FIG. 2, and the section B is the time of deformation shown in FIG.
Thus, in this embodiment, because of the two-stage absorption structure, the absorption performance can be improved over the conventional one. Moreover, since the two-stage absorption structure is a simple structure, an increase in cost can be suppressed.
If the second absorbing member 3 is configured to be more easily deformed than the front bumper member 1 and the first absorbing member 2 is more easily deformed than the second absorbing member 3, load absorption can be performed smoothly. it can.

  There are several variations of this embodiment. For example, in FIG. 5, the ends 2a 'and 2a' of the first absorbing member 2 'in the vehicle vertical direction and the ends 3a' and 3a 'of the second absorbing member 3' in the vehicle vertical direction are mutually connected. The front bumper 1 is overlapped and joined to the front end 1e of the cross section. Further, in FIG. 6, the ends 2 a ″ and 2 a ″ of the first absorbing member 2 ″ in the vehicle vertical direction are joined to the cross-section base end side 1 a other than the flange portions 1 b and 1 c of the front bumper 1, and Ends 3 a ″ and 3 a ″ in the vehicle up-down direction of the 2 absorbent member 3 ″ are joined to the front end 1 e of the cross section of the front bumper 1.

Next, a bumper structure for an automobile according to a reference embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 7, the front bumper member 5 of this preferred embodiment is the same as the front bumper member 1 in the embodiment of the present invention. The front bumper member 5 has a substantially flat portion 5a extending in the vehicle vertical direction at the front end of the cross section, and an absorbent member 6 having a U-shaped cross section is formed on the front bumper member 5 so as to cover the substantially flat portion 5a. An opening is provided. The absorbing member 6 is formed with a receiving surface 6a that is separated from the substantially flat portion 5a of the front bumper member 5 and extends substantially parallel to the substantially flat portion 5a. The absorbing member 6 is joined at the upper part and the lower part of the front bumper member 5. More specifically, the upper joint position 7a and the lower joint position 7b of the front bumper member 5 are offset by a distance D in the vehicle longitudinal direction, and the upper joint position 7a of the front bumper member 5 is the lower joint position 7b. The front bumper member 5 is located closer to the proximal end side of the front bumper member 5 than the vehicle.
In this preferred embodiment, as shown in FIG. 7, one of the absorbing member 6 in the front bumper member 5 provided, is a one-step-absorbing structure, the joining position 7a in the vehicle longitudinal direction of the absorbent member 6, 7b are top and bottom In addition, since the upper side of the absorbing member 6 is stepped close to the joining position 7a, the upper side is more easily crushed than the lower side of the absorbing member as shown in FIG. In the conventional structure shown in FIG. 11, when the upper and lower parts are joined at substantially the same position without being offset, when energy is input to the vehicle by a pedestrian, the absorbing member 85 joined to the front bumper member 84 is the upper part. It deformed the same in the lower, but results in hindering the movement of the legs of the pedestrian tilting the vehicle side, according to this preferred embodiment, without interfering with the movement of the rotation direction R shown in FIG. 8, Input energy can be absorbed, and insufficient deformation at the upper portion of the absorbing member 6 can be solved.

In addition, although embodiment and reference form were demonstrated about this invention, it can comprise by combining both as other embodiment.
In the embodiment and the reference embodiment described above, the front bumper members 1 and 5 and the absorbing members 2, 2 ′, 2 ″, 3, 3 ′, 3 ″ and 6 are formed in a substantially U-shaped cross section. The term “substantially U-shaped” includes a substantially U-shaped cross section. Further, the present invention can be applied not only to the front bumper members 1 and 5 but also to the rear bumper members (not shown).

1 is a cross-sectional view of a bumper structure for an automobile according to an embodiment of the present invention. It is a cross-sectional view which shows the mode of a deformation | transformation when there exists input in the bumper structure for motor vehicles of FIG. It is a cross-sectional view which shows the mode of a deformation | transformation when there exists further input in the bumper structure for motor vehicles of FIG. FIG. 2 is a graph showing load-deformation characteristics in the automobile bumper structure of FIG. 1, where the vertical axis represents the load and the horizontal axis represents the deformation amount. It is a cross-sectional view corresponding to FIG. 1 which shows the modification in embodiment of this invention. It is a cross-sectional view corresponding to FIG. 1 which shows another modification in embodiment of this invention. It is a cross-sectional view of the bumper structure for automobiles according to the reference embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state of deformation when there is an input to the automobile bumper structure of FIG. 5. It is a perspective view of the bumper structure for conventional vehicles. It is sectional drawing by line XX of FIG. FIG. 10 is a transverse cross-sectional view showing a state of deformation when there is an input to the automobile bumper structure of FIG. 9.

Explanation of symbols

1, 5 Front bumper member 1a Cross-section base end side 1b, 1c, 2b, 2c Flange 1d Outer surface 1e Cross-section tip side 2, 2 ', 2 "First absorbing member 2a, 2a', 2a", 3a ', 3a ″ end 3, 3 ′, 3 ″ second absorbing member 5a substantially flat portion 6 absorbing member 6a receiving surface 7a, 7b joining position A, B section D distance L vehicle longitudinal direction R rotational direction

Claims (2)

In a bumper structure for an automobile in which an energy absorbing member is provided on the outer surface of a bumper member that extends in the vehicle width direction and is attached to the vehicle,
A first energy absorbing member having a substantially U-shaped cross section covers the outer surface of the bumper member, and a second energy absorbing member having a substantially U-shaped cross section is disposed on the bumper member side between the bumper member and the first energy absorbing member. An opening is provided, and a substantially U-shaped bottom portion of the first energy absorbing member, a substantially U-shaped bottom portion of the second energy absorbing member, and the bumper member are spaced apart from each other in the vehicle longitudinal direction. and bumper structure for a motor vehicle, characterized in that it is joined to the first energy-absorbing member to the bumper member, and bonding the second energy absorbing member in the bumper member. A substantially flat portion extending in the vehicle vertical direction is formed at the front end of the cross section of the bumper member, and a receiving surface that is spaced apart from the substantially flat portion and extends substantially parallel to the substantially flat portion is formed on the second energy absorbing member, 2. The second energy absorbing member has a fixing portion at an upper portion and a lower portion of the bumper member, and the upper fixing portion is disposed closer to the proximal end side of the bumper member than the lower fixing portion. The bumper structure for cars described in 1.

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