JP2020164078A - Pedestrian leg part protection structure of vehicle - Google Patents

Abstract

To provide a new pedestrian leg part protection structure of a vehicle which can perform impact absorption with a simple structure.SOLUTION: A pedestrian leg part protection structure 10 of a vehicle according to the invention includes: a bumper beam 11 extending in a vehicle width direction W; and an impact absorption member disposed at the front side 111 of the bumper beam. The impact absorption member includes: an upper surface 12a located at the vehicle upper side; a lower surface 12b which is disposed facing the upper surface and located at the vehicle lower side; and a front surface which is connected to the upper surface and the lower surface through an upper bending part A1 and a lower bending part B1. The upper surface 12a is formed so as to incline downward to the upper bending part A1. The lower bending part B1 is formed so as to be located closer to the vehicle rear X2 than the upper bending part A1.SELECTED DRAWING: Figure 3

Description

The present invention relates to a pedestrian leg protection structure for a vehicle.

In recent years, a configuration has been proposed that reduces injuries to the legs when the vehicle comes into contact with a pedestrian while traveling. For example, a plate-shaped shock absorbing member whose upper surface is inclined downward toward the front of the vehicle is fixed to the front portion of the bumper beam, and a plate-shaped back support portion is provided in the space formed between the bumper beam and the shock absorbing member. The configuration is disclosed.

WO2011 / 099206

In the configuration of Patent Document 1, when the vehicle and the object come into contact with each other, the shock absorbing member is deformed to the rear of the vehicle and the lower side of the vehicle, and the shock absorbing member interferes with the back support portion in the middle of the process, so that the back support portion is also a vehicle. It deforms backward and absorbs shock. For this reason, there is a concern that sufficient shock absorption cannot be performed without the back support portion, and the number of parts increases by the amount of the back support portion, so there is room for improvement.
An object of the present invention is to provide a new pedestrian leg protection structure for a vehicle that can absorb shocks with a simple structure.

In order to achieve the above object, the pedestrian leg protection structure of the vehicle according to the present invention includes a bumper beam extending in the vehicle width direction and a shock absorbing member arranged on the front side of the bumper beam. It has an upper surface located above the vehicle, a lower surface located opposite the upper surface, and a front surface connected to the upper surface and the lower surface via an upper bending portion and a lower bending portion, and the upper surface is an upper bending portion. It is characterized in that it is formed so as to be inclined downward toward the vehicle, and the lower bent portion is formed so as to be located closer to the rear of the vehicle than the upper bent portion.

According to the present invention, the vehicle has an upper surface located above the vehicle, a lower surface located opposite the upper surface and located below the vehicle, and a front surface connected to the upper surface and the lower surface via an upper bending portion and a lower bending portion. Since the shock absorbing member is provided so that the upper surface is formed so as to be inclined downward toward the upper bent portion and the lower bent portion is located closer to the rear of the vehicle than the upper bent portion, the front of the vehicle is provided. When a load is applied from the vehicle, the shock absorbing member is displaced to the rear of the vehicle but is surely displaced to the lower side of the vehicle. Therefore, the pedestrian legs of a new vehicle that can absorb the shock even with a simple configuration with a reduced number of parts. A part protection structure can be provided.

The schematic view which shows the front body structure of the vehicle to which the pedestrian leg protection structure of the vehicle which concerns on this invention is applied. The side view explaining the pedestrian leg protection structure of the vehicle which concerns on this invention. An enlarged view showing the state of the bumper and the shock absorbing member before and after the collision with the object. The figure explaining the relationship between the approach angle of a vehicle and a shock absorbing member. The side view which shows the state before the collision of the shock absorbing member which concerns on this embodiment and the shock absorbing member which concerns on a comparative example. The figure which shows the state after the collision of the shock absorbing member which concerns on this embodiment and the shock absorbing member which concerns on a comparative example. The figure which shows the characteristic of the injury value by the pedestrian leg protection structure of the vehicle which concerns on this embodiment, and the pedestrian leg protection structure of the vehicle which concerns on a comparative example. (A) to (c) are diagrams showing the difference in the shape of the shock absorbing member. The figure which compared the difference of the cross-sectional shape of a shock absorbing member. The figure which shows the characteristic of the injury value by the difference of the cross-sectional shape shown in FIG. (A) to (c) are diagrams in which the state of shock absorption characteristics and the load characteristics at the time of initial load and maximum deformation are plotted at the same time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, the same members and members having the same functions are designated by the same reference numerals, and duplicate description will be omitted. The drawings may be partially omitted or simplified to help the understanding of some configurations.
FIG. 1 shows a front vehicle body structure of a vehicle 1 to which the pedestrian leg protection structure 10 according to the present invention is applied. In FIG. 1, the vehicle 1 is provided with metal side members 2 and 3 extending in the vehicle front-rear direction X in the vehicle width direction W. A radiator 20 is provided between the side members 2 and 3.
A metal bumper beam 11 extending in the vehicle width direction W is fixed to the front ends 2a and 3a of the side members 2 and 3 located in front of the vehicle X1 with respect to the radiator 20. The portions of the side members 2 and 3 between the bumper beam 11 and the radiator 20 are formed to function as crash boxes 7 and 8. The structure may be such that the crash boxes 7 and 8 are not provided and the bumper beam 11 and the side members 2 and 3 are attached. As shown in FIG. 2, a bumper 4 is arranged in front of the bumper beam 11 in front of the vehicle X1. A space portion 5 is formed between the bumper 4 and the bumper beam 11. A plate-shaped shock absorbing member 12 is arranged in the space portion 5. In the present embodiment, the pedestrian leg protection structure 10 includes a bumper beam 11 and a shock absorbing member 12, and the shock absorbing member 12 is arranged on the front side of the bumper beam 11. In the present embodiment, the bumper 4 is provided with a bumper facer flange 40.

The bumper beam 11 is formed in a closed cross-sectional structure by joining the inner panel 110 and the outer panel 111. The front portion of the bumper beam 11 is composed of an outer panel 111. The bumper beam 11 is formed by press-molding an inner panel 110 and an outer panel 111. The outer panel 111 is arranged so as to face the upper surface 111a that is inclined downward toward the front X1 of the vehicle and the lower surface 111b that is inclined up and inclined toward the front X1 of the vehicle, and is arranged between the upper surface 111a and the lower surface 111b. It includes a front surface 111c connected to the lower surface 111a and the lower surface 111b, an upper flange 111d, and a lower flange 111e.
The front surface 111c is formed as a substantially vertical plane, and an upper bending portion A is formed between the front surface 111c and the lower surface 111a, and a lower bending portion B is formed between the front surface 111c and the lower surface 111b. The upper flange 111d is formed as a substantially vertical surface. The lower flange 111e is bent 90 degrees to the rear X2 of the vehicle so as to be orthogonal to the front surface 111c. The plate thickness and cross-sectional structure of the bumper beam 11 are set so that the rigidity of the bumper beam 11 is at least higher than that of the shock absorbing member 12.

The shock absorbing member 12 is fixed to the upper flange 111d and the lower flange 111e of the bumper beam 11. The shock absorbing member 12 has an upper surface 12a located above the vehicle Z1 and a lower surface 12b located opposite the upper surface 12a and located below the vehicle Z2, and an upper bending portion A1 and a lower bending portion B1 on the upper surface 12a and the lower surface 12b. It has a front surface 12c connected via the front surface 12c. The shock absorbing member 12 includes an upper flange portion 12d and a lower flange portion 12e. The upper flange portion 12d is connected to the upper surface 12a. The lower flange portion 12e is connected to the lower surface 12b. The upper flange portion 12d and the lower flange portion 12e are formed as substantially vertical planes, and together with the upper flange 111d and the lower flange 111e of the bumper beam 11, the inner panel 110 is provided with various fastening members such as bolts 13 and nuts 140, respectively. It is fixed to the bumper beam 11 by being fastened together. Further, the lower bent portion B1 is formed so as to be located closer to the rear of the vehicle than the upper bent portion A1.

The upper surface 12a is formed so as not to be parallel to the lower surface 12b and to be inclined downward toward the upper bending portion A1, and the upper bending portion A1 is formed between the upper surface 12a and the front surface 12c. The lower surface 12b is formed substantially horizontally, is provided so that the lower surface 12b is less inclined than the upper surface 12a with respect to the horizontal plane, and a lower bent portion B1 is formed between the lower surface 12b and the front surface 12c. In the present embodiment, the lower bent portion B1 is formed so as to be located closer to the rear X2 of the vehicle than the upper bent portion A1. That is, the lower surface 12b of the shock absorbing member is arranged so as to be located above the bumper facer flange 400.

On the upper surface 12a, a plurality of upper bead portions 14 extending from the upper flange portion 12d side toward the upper bending portion A1 as reinforcing members are formed so as to be arranged in parallel in the vehicle width direction W. On the lower surface 12b, a plurality of lower bead portions 15 extending from the lower flange portion 12e toward the lower bending portion B1 as reinforcing members are formed so as to be arranged in parallel in the vehicle width direction W. The upper bead portion 14 is formed so as to be located between the upper bent portion A and the upper bent portion A1. The lower bead portion 15 is formed so as to be located between the lower bent portion B and the lower bent portion B1. The lower surface 12b of the shock absorbing member 12 is arranged so as to be located above the bumper facer flange 40. That is, the bumper facer flange 40 is arranged below the lower surface 12b of the shock absorbing member 12. Further, at least one of the upper surface 12a and the lower surface 12b is provided with upper bead portions 14 and 15 as reinforcing members. The lower surface 12b of the shock absorbing member 12 is arranged so as to be located above the bumper facer flange 40.

According to the pedestrian leg protection structure 10 having such a configuration, as shown in FIG. 3, when a load F from the vehicle front X1 side toward the vehicle rear X2 is applied to the bumper 4, as shown by a broken line in the figure. , The bumper 4 retracts and comes into contact with the shock absorbing member 12. Then, as shown by the white broken line, the shock absorbing member 12 is surely displaced to the lower Z2 of the vehicle while being displaced to the rear X2 of the vehicle, so that shock absorption can be performed even with a simple configuration in which the number of parts is reduced. ..
That is, in the pedestrian leg protection structure 10 according to the present embodiment, the upper surface 12a and the lower surface 12b of the shock absorbing member 12 are not parallel to each other, the upper surface 12a is inclined downward toward the vehicle front X1, and the lower surface 12b is substantially horizontal. By forming the upper surface 12a, the upper surface 12a is laid down more than the angle of the lower surface 12b. Further, the lower bent portion B1 is formed so as to be located closer to the rear X2 of the vehicle than the upper bent portion A1. Therefore, when a load F is applied from the vehicle front X1 and a load is received from the retracted bumper 4, the upper surface 12a is displaced so as to be folded downward by the upper bending portion A, and the lower bending portion B1 is directed toward the vehicle lower Z2. To move. Therefore, the lower surface 12b also moves to the lower side of the vehicle Z2 and the rear side of the vehicle X2, and the angle of the upper bent portion A1 is opened, so that the shock absorbing member 12 is deformed into a substantially rhombus shape and its length is extended to the lower side of the vehicle Z2. ..
Further, since the bumper facer flange 40 is arranged below the lower surface 12b of the shock absorbing member 12, the bumper facer flange 40 is pushed toward the vehicle lower Z2 by the shock absorbing member 12 deformed to the vehicle lower Z2, and the bumper 4 Is pushed down toward Z2 below the vehicle.

When the pedestrian leg protection structure 10 according to the present embodiment is adopted in a vehicle having a high vehicle height such as an SUV vehicle, it can contribute to reducing the injury value of the pedestrian leg to the lower part of the vehicle.
By adopting the pedestrian leg protection structure 10 according to the present embodiment, as shown in FIG. 4, it is possible to improve the collision performance while ensuring the ground clearance S and the approach angle θ during normal driving. For this reason, the bumper 4 and the shock absorbing member 12 are deformed toward the vehicle lower Z2 at the time of contact with a pedestrian or the like, and the shock absorbing member 12 is deformed toward the vehicle lower Z2 after the collision, so that the pedestrian's legs It can support the lower side. Further, this deformation is pushed down by pushing the lower surface of the bumper facer flange 40, and as a result, the entire surface of the bumper 4 is lowered, so that the lower side of the leg can be further supported. Further, even if the bumper facer flange 40 is not set low, it is pushed down only in the event of a collision. Therefore, since the space between the vehicle 1 and the road surface R can be secured, it becomes easy to introduce the traveling wind during traveling to the radiator 20, and improvement in cooling performance during normal operation can be expected.
In the present embodiment, reinforcing members are provided on at least one of the upper surface 12a and the lower surface 12b, and in particular, in this embodiment, the upper bead portion 14 and the lower bead portion 15 are formed, and thus these are reinforced. Depending on the member, the upper surface 12a and the lower surface 12b of the shock absorbing member 12 are pushed down while being maintained, and as a result, it also contributes to pushing down the bumper 4, and the bead depends on the applicable vehicle type, the shape of the front part of the vehicle, and the like. By increasing or decreasing the number of portions, the rigidity of the upper surface 12a and the lower surface 12b and the vertical balance can be adjusted, and the impact absorption characteristics due to the deformation of the impact absorbing member 12 can be easily controlled, which is also advantageous in terms of versatility. is there.

Next, a collision test and a result of a test body (impactor) K imitating a pedestrian's leg and a vehicle provided with the pedestrian's leg protection structure 10 will be described. The test body K imitates the vicinity of the knee, and the lower portion is provided so as to be swingable in the vehicle front-rear direction X around the fulcrum portion K1.
FIG. 5 shows the state before the collision, and FIG. 6 shows the state after the collision in an enlarged manner. In FIGS. 5 and 6, the member shown by the broken line shows a comparative example of a shock absorbing member having a shape different from that of the present embodiment. FIG. 7 shows the characteristics of the injury value according to the configuration of the present embodiment and the comparative example. The injury value is an index showing the bending moment associated with the fracture. The vertical axis shows the bending moment (Nm), and the horizontal axis shows the time.
The test conditions are the same except for the shape of the shock absorbing member, and the test body (impactor) K is tested by the shock device in accordance with the standards set by the National Agency for Automotive Safety and Victims, etc. It was fired at a predetermined speed toward the bumper 4 and collided. According to the test results, it was obtained that the injury value due to the configuration of the present embodiment was reduced as compared with the configuration of the comparative example.

FIG. 8 is a diagram showing a difference in the shapes of the shock absorbing members, and here, the three shapes are referred to as cases 1 to 3, respectively. 8 (a) shows a front view of each case, FIG. 8 (b) shows a side view of each case, and FIG. 8 (c) shows a perspective view of each case. FIG. 9 is a diagram comparing the cross-sectional shapes of the cases 1 to 3. In Cases 1 to 3, the shape of the upper surface 12a of the shock absorbing member 12 is the same, and the degree of inclination (angle) of the lower surface 12b is changed. In the case 1, the lower surface 12b is inclined upward toward the vehicle front X1, in the case 2 the lower surface 12b is horizontal, and in the case 3, the lower surface 12b is inclined downward toward the vehicle front X1.

FIG. 10 shows the result of the injury value when the load F is applied from the vehicle front X1 to the configuration of each case, and FIG. 11A shows the load (kN) characteristic in the configuration of each case. In FIG. 11A, the vertical axis represents the load on the shock absorbing member, and the horizontal axis represents time. FIG. 11B schematically shows the state of the shock absorbing member of each case at the time of initial load, and FIG. 11C schematically shows the state at the time of maximum deformation.
As a result of comparing each case, when the lower surface 12b of the shock absorbing member 12 is horizontal as in case 2, the maximum value of the injury value can be suppressed as compared with other cases as shown in FIG. Further, as shown in FIG. 11A, in the case of the case 2 in which the lower surface 12b is horizontal, the result was obtained that the load rises quickly and the peak value of the load at the time of maximum deformation is also reduced.
As a result, the shape of the lower surface 12b of the shock absorbing member 12 does not have to be parallel to the upper surface 12a, and is preferably ascending with respect to the vehicle front X1 as in case 1 or horizontal as in case 2. It can be said that the horizontal lower surface 12b at which the load rises quickly is preferable when the shock absorbing effect is obtained at an early stage.
That is, in the present embodiment, the lower surface 12b is formed as a horizontal surface, but the shape is not limited to this, and at least the lower surface 12b does not have to be parallel to the upper surface 12a and ascends toward the vehicle front X1. It may be an inclined surface that is inclined or a downward inclination toward the vehicle front X1.

According to such a configuration, the injury value and the load can be reduced even if the back support portion that assists the shock absorption is not provided between the bumper beam 11 and the shock absorbing member 12 as in the conventional case, so that the structure is simple. It is possible to provide a new vehicle pedestrian leg protection structure capable of shock absorption in the configuration.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such a specific embodiment, and unless otherwise specified in the above description, the present invention described in the claims. Various modifications and changes are possible within the scope of the invention.

The effects described in the embodiments of the present invention merely list the most preferable effects arising from the present invention, and the effects according to the present invention are limited to those described in the embodiments of the present invention. is not.

1 ... Vehicle, 2, 3 ... Side member, 2a, 3a ... Front part of side member, 4 ... Bumper, 10 ... Pedestrian leg protection structure, 11 ... Bumper beam, 12 ... Shock absorbing member, 12a ... Upper surface, 12b ... Lower surface, 12c ... Front surface, 14 ... Upper bead portion (reinforcing member), 15 ... Lower bead portion (reinforcing member), 40 ... Bumper facer flange, 111 ... Front part of bumper beam, A1 ... Upper bending part, B1 ... Lower bending part, W ... Vehicle width direction, X ... Vehicle front / rear direction, X1 ... -Vehicle front, X2 ... Vehicle rear, Z ... Vehicle vertical direction, Z1 ... Vehicle upper, Z2 ... Vehicle lower

Claims (5)

The bumper beam extending in the width direction of the vehicle and
A shock absorbing member arranged on the front side of the bumper beam is provided.
The shock absorbing member is
The upper surface located above the vehicle and
The lower surface, which is arranged to face the upper surface and is located below the vehicle,
The upper surface and the lower surface are provided with a front surface connected via an upper bending portion and a lower bending portion.
The upper surface is formed so as to be inclined downward toward the upper bent portion.
A pedestrian leg protection structure for a vehicle, wherein the lower bent portion is formed so as to be located closer to the rear of the vehicle than the upper bent portion. The pedestrian leg protection structure for a vehicle according to claim 1, wherein a reinforcing member is provided on at least one of the upper surface and the lower surface. The walking of a vehicle according to claim 2, wherein a plurality of the reinforcing members extending toward the upper bent portion are formed on the upper surface so as to be arranged in parallel in the vehicle width direction. Person leg protection structure. The vehicle according to claim 2 or 3, wherein a plurality of the reinforcing members extending toward the bent portion of the front lower portion are formed on the lower surface so as to be arranged in parallel in the vehicle width direction. Pedestrian leg protection structure. A bumper provided in front of the vehicle with the bumper beam and having a bumper facer flange is provided.
The pedestrian leg protection of a vehicle according to any one of claims 1 to 4, wherein the lower surface of the shock absorbing member is arranged so as to be located above the bumper facer flange. Construction.

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