JPH10310009A - Energy absorbing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently make good use of energy absorbing stroke and improve safety by locating an impact point at the vehicle inside of an inflection point of a pillar garnish and an energy absorbing body recessed part corresponding to the vertex of a vehicle inside projecting part of a body inner at the vehicle outside of a head centroid advancing in an impact direction. SOLUTION: An energy absorbing body 1 has surfaces which are roughly along a body inner vehicle inside surface and a pillar garnish rear surface. A body inner 2 has body flanges 21, 22 at both the sides and a projecting part 23 projecting toward the vehicle inside is formed on the halfway from an opening trim 98 to a front window 97. An energy absorbing body recessed part 11a is formed so as to correspond to a vertex 23a of this projecting part 23. When stipulated impact direction is applied to an FMVSS 201 in which a distance L1 from the body inner 2 to a dummy 5 of a head part which is abutted on the pillar garnish becomes the shortest, energy absorbing stroke can be sufficiently made good use of and becomes useful on safety.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing structure which is incorporated in a pillar garnish such as a front pillar and a center pillar of a passenger car and can effectively absorb impact energy.

[0002]

2. Description of the Related Art In recent years, studies for protecting occupants in the event of a vehicle collision have been actively conducted. US Federal Motor Vehicle Safety Standard FMVSS201 implemented from September 1998
(Federal Motor Vehicle Safety Standards)
Attempts have been made to reduce the injury value so that the occupant's head does not collide with the interior of the vehicle during a vehicle collision and cause tissue damage to the head. As a result, the pillar garnish, which is an interior part of the car, may have an impact on the occupant's head in the event of a vehicle collision. Therefore, an energy absorbing material is provided on the back of the pillar garnish (body inner side) to reduce the injury value. Consideration to make it begin. In particular, lattice-shaped resin ribs are exclusively studied as energy absorbing materials because of their ease of assembly and mass production.

The FMVSS 201 is currently the most effective means for measuring the injury value of the occupant's head at the time of a vehicle collision. The test method consists of two dummy heads (weight 4.54 kg) with a horizontal angle of 105 ° to 165 ° and a vertical angle of 5 ° to 50 ° at the collision position determined by MVSS201.
4 km / h or more (equivalent to a vehicle collision speed of 5024 km / h)
Collide at speed. Then, the injury value is calculated as Hic (d) (He
ad injury criteriad: dummy) and FMV
According to SS201, if Hic (d)> 1000, tissue damage to the occupant's head will be caused. Where Hi
c (d) is represented by the following equation.

[0004]

[Table 1]

[0005] Under these circumstances, based on FMVSS201, the pillar garnish has the highest energy absorption stroke (the distance from the body to the FMH (Free Motion Headform) at the time of hitting the pillar garnish) in the direction of impact which is the shortest. Injury values are expected to be high.

[0006]

However, the conventional pillar garnish has a problem if it is considered from the FMVSS201. That is, the conventional pillar garnish 91 has an energy absorption stroke L as shown in FIG. 8 and has a shape in which the body inner shape is expanded toward the indoor side. When the impact force F is applied in the impact direction in which the energy absorption stroke L is shortest,
F _x acting on the receiving surface 93a of the body inner 93 of energy absorber 92 to the front Windu 97 side occurs. Therefore, the energy absorbing member 92 slid toward the front window 97 without fully utilizing the energy absorbing stroke L, and the occupant's head hit the body flange 931 at the time of a collision, and Hic (d) was increased. The above contents are described in detail with reference to FIG. 8. According to the test method of FMVSS201, a dummy 5 (FMH: Free Motio
n headform), the impact force F of the FMH acts in the direction of impact and acts as a force F 'in the direction normal to the tangent surface of the pillar garnish. Then, the force F ′ acting on the pillar garnish 91 is transmitted to the energy absorbing material 92 (for example, a lattice-shaped resin rib), and the body inner receiving surface 9 is formed.
"A. The force F" force F acting on the 3a is decomposed into a force f _x of the force f _y the plane direction of the body inner surface normal direction. The component force f _y, f _x are linked to the behavior of the energy absorbing member 92. Since the component force f _x is working inside the vehicle, the energy absorbing member 92 is deviated to the inner side of the vehicle,
The energy absorption stroke L could not be fully utilized, which eventually resulted in applying a high impact force to the occupant's head.

The present invention solves the above problems,
Provides an energy absorbing structure that can fully utilize the energy absorbing stroke when the impact direction specified in FMVSS201 is applied, which minimizes the distance from the body inner to the dummy of the head in contact with the pillar garnish The purpose is to do.

[0008]

In order to achieve the above object,
The gist of the invention according to claim 1 is that, in an energy absorbing structure in which an energy absorber is mounted between a body inner and a pillar garnish, an impact point defined by FMVSS201 is on the vehicle inner side than an inflection point according to the pillar garnish. With respect to the impact direction defined by FMVSS201, in which the distance from the body inner to the dummy of the head in contact with the pillar garnish is the shortest, the position of the center of gravity of the head traveling in the impact direction is larger than that of the vehicle with the body inner. An energy absorbing structure is characterized in that the absorber concave portion corresponding to the top of the inner convex portion is located outside the vehicle.

According to the first aspect of the present invention, the impact point is located on the vehicle inner side with respect to the inflection point relating to the pillar garnish, and the vehicle inner convex portion of the body inner is located with respect to the position of the center of gravity of the head in the impact direction. When absorber recesses corresponding to the vertex is on the vehicle outer side, the force f _x acting on the receiving surface of the body inner energy absorber is directed toward the vehicle outer side, the energy absorber without slipping, energy absorbing The stroke can be fully utilized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the energy absorbing structure according to the present invention will be described in detail. 1 to 5 show an embodiment of the energy absorber of the present invention. FIG. 1 is a cross-sectional view of an energy absorber disposed in a space surrounded by a body inner frame and a pillar garnish.
FIG. 2 is a perspective view of a vehicle interior around a pillar garnish, and FIG.
FIG. 4 is a perspective view of the pillar garnish, FIG. 4 is a graph showing acceleration vs. time characteristics, and FIG. 5 is a graph showing the relationship between the amount of deformation and the generated load. Here, it applies to the front pillar.

In the energy absorbing structure of the present invention, an energy absorber 1 is mounted between a body inner 2 and a pillar garnish 3 as shown in FIG. FIG. 1 shows A in FIG.
-A line arrow view is shown, but in order to prevent complication, only main parts are drawn in an easily understandable manner, and other constituent parts omitted,
For example, body outer 96, opening trim 9
8, body outer plate 99 and the like conform to FIG.

The energy absorber 1 is made of an absorber having a surface substantially along the inner surface of the body inner vehicle and the back surface of the pillar garnish. The body inner 2 has body flanges 21 and 22 on both sides, and a convex portion 23 protruding toward the inside of the vehicle is formed on the way from the opening trim 98 to the front window 97 as shown in FIG. Then, the absorber concave portion 11a is formed so as to correspond to the convex vertex 23a. Further, the pillar garnish 3 has an inflection point 31 having a substantially L-shape in cross section, and the energy absorber 1 also has an inflection point 31 corresponding to the inflection point 31 in the pillar garnish side having a substantially L-shape in cross section. It has a curved point 12. In the present embodiment, a lattice-shaped resin rib is used for the energy absorber 1 (FIG. 3), but it is of course possible to use a foam or a metal energy absorber.

The inflection point 31 is the FMVSS 20
1 is located outside the vehicle with respect to the impact point 4 defined in FIG. Here, FMVSS of FMVSS201
Stands for Federal Motor Vehicle Safety Standards,
Means the United States Federal Motor Vehicle Safety Standards effective September 1998. The impact point 4 is uniquely determined by the definition of FMVSS201.

Further, the impact direction swings through the impact point 4 specified in the FMVSS 201, but the distance L ₁ from the body inner 2 to the dummy 5 of the head in contact with the pillar garnish 3 becomes the shortest. FMVSS2
With respect to the impact direction defined in 01, the absorber concave portion 11a corresponding to the apex 23a of the vehicle inner convex portion 23 of the body inner 2 is located on the vehicle outer side of the position of the center of gravity 5a of the head traveling in the impact direction. The distance L from the body inner 2 to the dummy 5 of the head in contact with the pillar garnish 3
_In the present embodiment, ₁ is the distance from the end of the body flange 21 to the head dummy 5.

In such an energy absorbing structure, FMVSS
FMH5 (Free Motion He
adform), the impact force F of the FMH 5 acts in the impact direction, and is transmitted as a force F _{X in the} direction normal to the collision point 4. The force F _X is further transmitted to the energy absorbers 1, next to the force f acting on the receiving surface of the body inner 2, the force f is decomposed into a component force f _x and f _y in the body inner surface. Then, the energy absorber 1 component force f _x is going to become a force for pressing the body in emissions donors. Collision point 4
In the conventional case, for example, 9 such that outside the inflection point 31, since the component force f _x acts in a direction to disengage the energy absorber 1 from the body-in emissions toner 2, the energy absorber 1
Has slipped inside the vehicle and escaped, but such a problem is solved. Thus, the component force f _y acts well, and the energy absorber 1 collapses and buckles, and can absorb impact energy.

Next, the performance of the energy absorbing structure according to the present invention was examined, and the test results will be described. An impact test of the energy absorbing structure product of FIG. 1 was performed, and from the acceleration vs. time characteristic graph (FIG. 4), the speed (calculation) was 24 km / h,
Maximum displacement 31.6 mm, maximum acceleration 117.1 G, maximum load 5.21 kN, Hic 534.7, Hic (d) 56
9.5 was obtained. Hic (d) (Head injury criteria d:
dummy) values are well below 1000. Also,
A graph of the relationship between the amount of deformation and the generated load (FIG. 5) was obtained, which shows that the initial load rises from the beginning and that the energy absorbing body 1 is effectively absorbing energy without slipping. On the other hand, the conventional structure shown in FIG. 8 has a velocity (calculated) of 24.27 km / h, a maximum displacement of 27.5 mm, a maximum acceleration of 245.2 G, and a maximum load of 10 in the acceleration vs. time characteristic graph (FIG. 6). .92kN, Hi
c 1411.0, Hic (d) 1230.3, Hi
The c (d) value has increased. In the graph of the relationship between the amount of deformation and the generated load (FIG. 7), it is ideal to keep the generated load at a low value even if the amount of deformation increases, as shown by the broken line. 10
While the initial load at the time of deformation by mm was as low as 3.0 kN, the maximum load was 10.92 kN at a deformation of 24.5 mm, which was a large value.

In the energy absorbing structure configured as described above, the energy absorber 1 is utilized without waste, as is apparent from the performance test, so that the injury value Hic (d) of the occupant head at the time of a vehicle collision can be reduced. Energy absorbing stroke is utilized to fully when the distance L ₁ from the body inner 2 to dummy 5 of abutting head on the pillar garnish 3 is the direction of impact defined in FMVSS201 having the shortest added. And since the energy absorber 1 can be utilized without waste, the energy absorption stroke can be shortened accordingly. Conventionally, the energy absorption stroke required to be 20 mm or more can be set to about 15 mm. On the other hand, since the energy absorption stroke can be shortened, a space is created on the vehicle interior side, and it is also possible to secure the visibility and improve the occupant's elevating and lowering properties.

In the present invention, the present invention is not limited to those shown in the above embodiments, but can be variously changed within the scope of the present invention depending on the purpose and application. The shape, size, material, and the like of the body inner 2, the pillar garnish 3, and the energy absorber 1 can be appropriately selected according to the application. The applicable range of the pillar garnish 3 includes a center pillar 7 and a rear pillar 8 in addition to the front pillar.

[0019]

As described above, the energy absorbing structure of the present invention provides the FMVSS2 having the shortest distance from the body inner to the dummy of the head in contact with the pillar garnish.
When an impact direction specified in 01 is applied, the energy absorption stroke can be fully utilized, which is extremely useful for improving safety.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an energy absorber disposed in a space surrounded by a body inner frame and a pillar garnish according to one embodiment of the present invention.

FIG. 2 is a perspective view of a vehicle interior around a pillar garnish.

FIG. 3 is a perspective view of a pillar garnish.

FIG. 4 is an acceleration vs. time characteristic graph.

FIG. 5 is a graph showing a relationship between a deformation amount and a generated load.

FIG. 6 is a graph showing acceleration vs. time characteristics in a conventional structure.

FIG. 7 is a graph showing a relationship between an amount of deformation and a generated load in a conventional structural product.

FIG. 8 is a cross-sectional view of an energy absorber disposed in a space surrounded by a body inner frame and a pillar garnish according to the related art.

FIG. 9 is an explanatory cross-sectional view of the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Energy absorber 11a Absorber concave part 2 Body inner 23a Top of convex part 3 Pillar garnish 31 Inflection point 4 Impact point 5 Dummy of head 5a Center of gravity of head L ₁ distance

Claims (1)

[Claims] 1. An energy absorbing structure in which an energy absorbing body is mounted between a body inner and a pillar garnish, wherein an impact point defined by FMVSS201 is located on a vehicle inner side than an inflection point relating to the pillar garnish, and For the impact direction specified by FMVSS201, in which the distance from the inner to the dummy of the head in contact with the pillar garnish is the shortest, the apex of the vehicle inner convex portion of the body inner is more than the position of the center of gravity of the head that advances in the impact direction An energy absorbing structure characterized in that an absorber concave portion corresponding to (1) is located outside the vehicle.