JP7787117B2 - Vehicle impact absorbing components - Google Patents

Description

The present invention relates to an impact absorbing member for a vehicle.

Patent Document 1 discloses an energy absorbing member made of a fiber-reinforced resin material, and the energy absorbing member disclosed in Patent Document 1 has a W-shaped cross section.
Conventionally, there is also an energy absorbing member having a U-shaped cross section.

7, the U-shaped cross section has a pair of side portions 81 and a connecting portion 82. The connecting portion 82 connects one ends of the pair of side portions 81 to each other.
As shown in Figure 8, the W-shaped cross section has a pair of inner portions 91, a connecting portion 92, a pair of extending portions 93, and a pair of outer portions 94. The connecting portion 92 connects one end of the inner portions 91 to each other. The pair of extending portions 93 extend away from each other from the other ends of the pair of inner portions 91. The pair of outer portions 94 extend by folding back at the tips of the pair of extending portions 93.

Japanese Patent Application Laid-Open No. 2008-221986

In an energy absorbing member having a U-shaped cross section, when a collision load is applied, the pair of side portions 81 tend to collapse in the direction in which the side portions 81 are aligned (left and right in Figure 7). In an energy absorbing member having a W-shaped cross section, when a collision load is applied, the pair of outer portions 94 tend to collapse in the direction in which the outer portions 94 are aligned (left and right in Figure 8). This collapse of the side portions 81 and outer portions 94 does not contribute to energy absorption, so there is room for improvement in terms of increasing energy absorption efficiency. Furthermore, an energy absorbing member having a W-shaped cross section has the problem of increased mass due to the long length of the pair of outer portions 94.

A vehicle impact absorbing component that solves the above problem is an impact absorbing component for a vehicle that includes an absorbing component main body formed by stacking and bonding multiple fiber-reinforced resin layers together, the absorbing component main body receiving a collision load in a first direction, and when a direction perpendicular to the first direction is defined as a second direction and a direction perpendicular to both the first and second directions is defined as a third direction, a cross section of the absorbing component main body perpendicular to the first direction is an open cross section, and has a pair of side portions that are spaced apart in the second direction and extend in the third direction, a connecting portion that connects one end of the pair of side portions in the third direction, a pair of extending portions that extend away from each other in the second direction from the other end of the pair of side portions in the third direction, and a pair of folded portions that are folded back at the tips of the pair of extending portions and extend toward the connecting portion in the third direction, the tips of the pair of folded portions being located closer to the extending portion than the midpoint of the side portions in the third direction.

FIG. 1 is a perspective view of an impact absorbing member for a vehicle according to an embodiment. FIG. 2 is a cross-sectional view of the impact absorbing member for a vehicle shown in FIG. FIG. 3 is a perspective view of the absorbent member main body of FIG. FIG. 4 is a perspective cross-sectional view showing the layer structure of the absorbent member main body of FIG. FIG. 5 is a cross-sectional view of the absorbent member of FIG. FIG. 6 is a cross-sectional view of the absorbent member of FIG. FIG. 7 is a cross-sectional view of an energy absorbing member having a U-shaped cross section. FIG. 8 is a cross-sectional view of an energy absorbing member having a W-shaped cross section.

Hereinafter, one embodiment of a vehicle impact absorbing member (hereinafter referred to as an impact absorbing member 20) will be described with reference to FIGS.
Hereinafter, the fore-and-aft direction of the vehicle will be referred to as the fore-and-aft direction L, the width direction of the vehicle as the vehicle width direction W, and the up-and-down direction of the vehicle when the vehicle is positioned on a horizontal plane as the up-and-down direction Z. Furthermore, the front and rear sides in the fore-and-aft direction L will be referred to simply as the "front side" and the "rear side", respectively, and the upper and lower sides in the up-and-down direction Z will be referred to simply as the "upper side" and the "lower side", respectively.

As shown in Figure 2, the front of the vehicle is provided with, in order from the front, a bumper reinforcement 10, an impact absorbing member 20, and a front side member 11. The impact absorbing member 20 is sandwiched between the bumper reinforcement 10 and the front side member 11 in the fore-and-aft direction L. Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1.

As shown in FIGS. 1 and 2 , the impact absorbing member 20 has a base portion 30 and an absorbing member main body 40 .
Next, each component of the impact absorbing member 20 will be described in detail.

<Absorbing member body 40>
As shown in FIGS. 1 to 3, the absorbing member main body 40 receives a collision load in the front-rear direction L and extends in the front-rear direction L.

In this embodiment, the longitudinal direction L corresponds to the first direction in the [Means for Solving the Problem], the vehicle width direction W corresponds to the second direction in the [Means for Solving the Problem], and the vertical direction Z corresponds to the third direction in the [Means for Solving the Problem]. In other words, the vehicle width direction W is a direction perpendicular to the longitudinal direction L, and the vertical direction Z is a direction perpendicular to both the longitudinal direction L and the vehicle width direction W.

As shown in FIG. 4, the absorbing member main body 40 is formed by pressing a laminate in which a plurality of fiber reinforced resin layers 41 are stacked and joined together.
The fiber reinforced resin layer 41 is formed by impregnating a plurality of reinforcing fibers 42 arranged in a sheet shape with a thermoplastic resin 43. The plurality of reinforcing fibers 42 constituting the fiber reinforced resin layer 41 are preferably long fibers and extend in a single direction.

The reinforcing fibers 42 are preferably glass fibers, and the resin 43 is preferably polypropylene or nylon.
The plurality of fiber reinforced resin layers 41 are joined to one another by welding. It is preferable that the reinforcing fibers 42 of adjacent fiber reinforced resin layers 41 extend perpendicular to one another.

As shown in FIGS. 1, 3, 5 and 6, the cross section of the absorbing member main body 40 perpendicular to the front-rear direction L is an open cross section.
The cross section of this embodiment has a symmetrical shape in the vehicle width direction W.

As shown in FIGS. 5 and 6, the cross section has a pair of side portions 51, a connecting portion 52, a pair of extending portions 53, and a pair of folded portions .
The pair of side portions 51 are spaced apart in the vehicle width direction W and extend in the up-down direction Z. In this embodiment, the pair of side portions 51 are inclined with respect to an imaginary line VL3 extending in the up-down direction Z so that the upper sides of the side portions 51 approach each other in the vehicle width direction W. The angle β formed between the imaginary line VL3 and the side portions 51 is preferably greater than 0 degrees and equal to or less than 30 degrees. More preferably, the angle β is equal to or greater than 3 degrees and equal to or less than 15 degrees.

The connecting portion 52 connects the upper ends of the pair of side portions 51. In this embodiment, the connecting portion 52 extends along an imaginary straight line VL2 extending in the vehicle width direction W. The upper ends of the pair of side portions 51 correspond to one end in the [Means for Solving the Problem].

The pair of extension portions 53 extend from the lower ends of the pair of side portions 51 so as to be separated from each other in the vehicle width direction W. The lower ends of the pair of side portions 51 correspond to the other ends in the "Means for Solving the Problems." In this embodiment, the extension portions 53 extend along the imaginary straight line VL2.

The pair of folded portions 54 are folded back at the tips of the pair of extending portions 53 and extend toward the connecting portion 52 in the vertical direction Z.
The tips of the pair of folded portions 54 are located closer to the extending portion 53 than the middle position of the side portion 51 in the vertical direction Z.

In this embodiment, the folded portion 54 extends at an angle so that the closer it is to the connecting portion 52 in the vertical direction Z, i.e., the higher it is, the further it is from the extending portion 53 in the vehicle width direction W. The angle α between the imaginary line VL3 and the folded portion 54 is preferably greater than 0 degrees and less than or equal to 30 degrees. It is more preferable that the angle α be greater than or equal to 3 degrees and less than or equal to 15 degrees.

It is preferable that the length L3 of the extension portion 53 in the vehicle width direction W is equal to or less than the length L2 of the connection portion 52 in the vehicle width direction W.
It is preferable that the shape and size of the cross section be the same throughout the entire front-rear direction L.

<Base portion 30>
As shown in FIGS. 1 and 2 , the base portion 30 is fixed to the rear end portion of the absorbent member main body 40 .

The pedestal portion 30 has a base portion 31 , a support protrusion 32 , and a collar 34 .
The base portion 31 has a substantially rectangular plate shape.
The support protrusion 32 protrudes forward from the front surface of the base portion 31. The support protrusion 32 has a groove portion 33 that receives and fixes the rear end portion of the absorbing member main body 40 (see FIG. 1).

Cylindrical collars 34 are integrally formed at the four corners of the base portion 31. Bolts (not shown) are inserted into the collars 34 to secure the base portion 30 to the front end of the front side member 11.

The pedestal portion 30 is formed by inserting the collar 34 into a molding die and then injecting molten resin into the cavity to form the base portion 31 and the support protrusions 32 .
Next, the operation of this embodiment will be described.

In the impact absorbing member 20 of this embodiment, the absorbing member main body 40 has a pair of extension portions 53 and a folded portion 54 on the outside of a pair of side portions 51 in the vehicle width direction W. This makes it less likely for the side portions 51 to collapse outward in the vehicle width direction W when the absorbing member main body 40 is subjected to a collision load. Furthermore, compared to when the tips of the pair of folded portions 54 are located closer to the connecting portion 52 than the midpoint of the side portions 51 in the vertical direction Z, the folded portions 54 are less likely to collapse outward in the vehicle width direction W when they are destroyed. Therefore, when the absorbing member main body 40 is compressed by a collision load, the load rises earlier than the displacement of the absorbing member main body 40, allowing the compressive collapse of the absorbing member main body 40 to proceed smoothly. This improves the energy absorption efficiency of the absorbing member main body 40. Furthermore, shortening the length of the folded portions 54 in the vertical direction Z reduces the mass of the absorbing member main body 40.

Next, the effects of this embodiment will be described.
(1) The impact absorbing member 20 includes an absorbing member main body 40 formed by stacking and bonding a plurality of fiber-reinforced resin layers 41 together. A cross section of the absorbing member main body 40 perpendicular to the front-rear direction L is an open cross section, and has a pair of side portions 51, a connecting portion 52, a pair of extending portions 53, and a pair of folded-back portions 54. The tips of the pair of folded-back portions 54 are located closer to the extending portions 53 than the middle positions of the side portions 51 in the up-down direction Z.

According to this configuration, the above-mentioned effect is achieved, and therefore the energy absorption efficiency per mass can be increased.
(2) The folded portion 54 extends at an angle such that the closer it is to the connecting portion 52 in the vertical direction Z, the further it is from the extending portion 53 in the vehicle width direction W. The angle α between the imaginary line VL3 and the folded portion 54 is greater than 0 degrees and is equal to or less than 30 degrees.

With this configuration, the absorbent member body 40 can be easily removed from the press die, and therefore the absorbent member body 40 can be easily manufactured.
(3) The connecting portion 52 and the pair of extending portions 53 extend along the imaginary straight line VL2 that extends in the vehicle width direction W. The length L3 of the extending portion 53 in the vehicle width direction W is equal to or less than the length L2 of the connecting portion 52 in the vehicle width direction W.

With this configuration, the pair of side portions 51 and the connecting portion 52 account for a larger proportion of the cross section. Here, the pair of side portions 51 and the connecting portion 52 contribute more to improving energy absorption efficiency than other portions. Therefore, energy efficiency can be effectively improved.

(4) The shape and size of the cross section are uniform throughout the entire length in the front-rear direction L.
With this configuration, compared to a configuration in which the cross-sectional size increases toward the rear in the front-rear direction L, the collision load rises at an earlier timing relative to the displacement of the absorbing member main body 40. This makes it easier for the absorbing member main body 40 to undergo compressive failure, thereby further improving the energy absorption efficiency.

<Example of change>
The above embodiment can be modified as follows: The present embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

For example, the cross-sectional size may be slightly larger toward the rear. Also, the cross-sectional shape may be slightly different depending on the position in the front-rear direction L.
The length L3 of the extension portion 53 in the vehicle width direction W may be longer than the length L2 of the connection portion 52 in the vehicle width direction W.

The connecting portion 52 and the pair of extending portions 53 do not have to extend along the virtual straight line VL2, and may be curved.
The angle α formed between the imaginary straight line VL3 and the folded-back portion 54 can be set to 0 degrees. Also, the angle β formed between the imaginary straight line VL3 and the side portion 51 can be set to 0 degrees.

- The absorbing member main body 40 illustrated in the above embodiment can also be positioned, for example, rotated 90 degrees around an axis extending in the longitudinal direction L. In this case, the vehicle width direction W corresponds to the third direction in the [Means for Solving the Problem], and the vertical direction Z corresponds to the second direction in the [Means for Solving the Problem].

DESCRIPTION OF SYMBOLS 10... Bumper reinforcement 11... Front side member 20... Impact absorbing member 30... Pedestal portion 31... Base portion 32... Support protrusion portion 33... Groove portion 34... Collar 40... Absorbing member main body 41... Fiber reinforced resin layer 42... Reinforced fiber 43... Resin 51... Side portion 52... Connecting portion 53... Extension portion 54... Folded portion 81... Side portion 82... Connecting portion 91... Inner portion 92... Connecting portion 93... Extension portion 94... Outer portion

Claims (4)

A vehicle impact absorbing member including an absorbing member main body formed by stacking and joining a plurality of fiber reinforced resin layers together,
the absorbing member main body receives a collision load in a first direction,
When a direction perpendicular to the first direction is defined as a second direction, and a direction perpendicular to both the first direction and the second direction is defined as a third direction,
A cross section of the absorbing member main body perpendicular to the first direction is
It is an open section,
a pair of side portions spaced apart from each other in the second direction and extending in the third direction;
a connecting portion connecting one ends of the pair of side portions in the third direction to each other;
a pair of extending portions extending from other ends of the pair of side portions in the third direction so as to be apart from each other in the second direction;
a pair of folded-back portions that are folded back at the tips of the pair of extending portions and extend toward the connecting portion in the third direction,
The tip ends of the pair of folded portions are located closer to the extending portion than intermediate positions of the side portions in the third direction.
Impact absorbing components for vehicles. the folded portion extends at an incline such that the folded portion approaches the connecting portion in the third direction and moves away from the extending portion in the second direction,
an angle formed between the virtual line extending in the third direction and the folded portion is greater than 0 degrees and less than or equal to 30 degrees;
The impact absorbing member for a vehicle according to claim 1 . the connecting portion and the pair of extending portions extend along an imaginary straight line extending in the second direction,
The length of the extending portion in the second direction is equal to or less than the length of the connecting portion in the second direction.
The impact absorbing member for a vehicle according to claim 1 or 2. The shape and size of the cross section are uniform throughout the first direction.
The impact absorbing member for a vehicle according to claim 1 .