JP2020125051A - Body skeleton reinforcement member - Google Patents

Abstract

To provide a body skeleton reinforcement member which prevents or suppresses destroy of a body skeleton member from a sewing part in bending deformation.SOLUTION: In a body skeleton reinforcement member 10, three carbon fiber fabrics 24, 26 and 28 are sewn in a laminate direction to obtain a carbon fiber fabric structure 32 having a closed cross-sectional structure, the carbon fiber fabric structure 32 is impregnated with a resin to obtain CFRP, and a predetermined strength is secured. However, the CFRP has a lower strength against a compressive stress than a tensile stress. The body skeleton member is provides with all sewing parts 30A to 30C on a side where a bending stress of tension acts rather than a neutral surface NS of bending deformation, and accordingly the bending stress of compression acts on the sewing parts 30A to 30C in lateral collision of the vehicle to become a starting point of destroy, and it can prevent or suppress disabling securing of the predetermined strength of the body skeleton member 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a body frame reinforcing member.

Composite materials such as fiber reinforced plastics are being adopted for the body frame reinforcing members of automobiles. For example, in Patent Document 1, a roof side rail in which a carbon fiber woven fabric having a rhombic closed cross section connected from one joint to the other joint by a first branch portion and a second branch portion is included in a plastic material is disclosed. The body is proposed.

This carbon fiber woven fabric has a higher weaving density on the side of the branched portion at the joint than that on the side separated from the branched portion, so that the joint is prevented from being broken as a fracture starting point. is there.

JP, 2017-7571, A

However, when the vehicle collides with an obstacle, the body skeleton member is bent and deformed in the extending direction, and when the body skeleton member is uniaxially bent and deformed, the joint portion is located on the side where the compressive bending stress acts rather than the neutral surface. When it is located, the joint portion is broken by the action of bending stress, and it is difficult for the body skeleton reinforcing member made of CFRP (carbon fiber reinforced plastic) to secure a predetermined bending strength.

That is, in the above-mentioned prior art, there is room for improvement from the viewpoint of preventing or suppressing breakage from the joint portion during bending deformation of the body frame member.

In view of the above facts, an object of the present invention is to provide a body skeleton reinforcing member that prevents or suppresses breakage of a sewn portion during bending deformation of the body skeleton member.

The body skeleton reinforcing member according to the invention according to claim 1 is a carbon fiber woven structure having a closed cross-section structure by a plurality of carbon fiber woven fabrics being laminated and a stitching portion obtained by stitching a plurality of carbon fiber woven fabrics in a laminating direction. A body skeleton reinforcing member which is obtained by impregnating a body with a resin and is integrated, wherein the sewn portion is provided only on a side where a tensile bending stress acts from a neutral surface of the body skeleton reinforcing member during bending deformation. ing.

In the body skeleton reinforcing member configured as described above, a carbon fiber woven fabric structure having a closed cross section structure is impregnated with a resin by sewing a plurality of carbon layer fiber woven fabrics in the stacking direction to form CFRP to ensure a predetermined strength. ing.

By the way, CFRP has lower strength against compressive stress than tensile stress. When the body skeleton member is bent and deformed due to a collision of a vehicle or the like, since the body skeletal member is provided with the sewn portion only on the side where tensile bending stress acts from the neutral surface of the bending deformation, the sewn portion It is possible to prevent or suppress that the body skeleton member cannot secure a predetermined strength because the suture portion becomes a starting point of fracture due to the action of compressive bending stress on the.

In other words, the body skeleton member can secure a predetermined strength by providing the sewn portion only on the side where the tensile bending stress acts from the neutral surface of the bending deformation.

Since the body skeleton reinforcing member according to the first aspect of the present invention is configured as described above, it is possible to prevent or suppress the destruction of the sewn portion during bending deformation of the body skeleton member.

It is the sectional view on the AA line of FIG. It is a perspective view showing a roof frame shape to which a body frame reinforcing member according to an embodiment is applied. It is sectional drawing equivalent to FIG. 1 of the body frame reinforcement member which concerns on the other example of 1st Embodiment. It is sectional drawing equivalent to FIG. 1 of the body frame reinforcement member which concerns on the other example of 1st Embodiment. It is sectional drawing equivalent to FIG. 1 of the body frame reinforcement member which concerns on the other example of 1st Embodiment. It is sectional drawing equivalent to FIG. 1 of the body frame reinforcement member which concerns on the other example of 1st Embodiment. It is sectional drawing equivalent to FIG. 1 of the body frame reinforcement member which concerns on the other example of 1st Embodiment.

A body frame reinforcing member according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. In each drawing, the arrow FR indicates the front of the vehicle, the arrow UP indicates the upper side of the vehicle, and the arrow LH indicates the left side in the vehicle width direction.

(Constitution)
In this embodiment, an example applied to a roof center reinforcement (hereinafter referred to as "roof center RF") as a body skeleton reinforcing member 10 of an automobile is shown.

First, the skeleton of the roof including the roof center RF will be described.

As shown in FIG. 2, the roof-side framework of the vehicle body 12 includes a pair of roof side rails 14A and 14B extending in the vehicle front-rear direction. The roof side rails 14A and 14B are integrally formed with the front pillars 16A and 16B.

A front header 18, a roof center RF 20, and a rear header 22 extending in the vehicle width direction are sequentially arranged between the roof side rails 14A and 14B from the vehicle front side.

The body skeleton reinforcing member 10 is applied to the roof center RF 20. Hereinafter, the body frame reinforcing member 10 will be described as the roof center RF 20.

The roof center RF20 is a member extending in the vehicle width direction, and its cross section in the vehicle front-rear direction (a cross section taken along line AA in FIG. 2) is shown in FIG. As shown in FIG. 1, the roof center RF 20 is formed by laminating three carbon fiber woven fabrics 24, 26 and 28.

The carbon fiber fabric 24 is a plain fabric of carbon fibers. In addition, the carbon fiber woven fabric 24 includes a bottom portion 24A extending in the vehicle front-rear direction, vertical wall portions 24B and 24C extending from both ends of the bottom portion to the vehicle upper side, and vehicle tops from the upper ends of the vertical wall portions 24B and 24C. It is formed in a hat-shaped cross section having flange portions 24D and 24E extending toward the rear of the vehicle.

The carbon fiber woven fabric 26 arranged on the carbon fiber woven fabric 24 is a multi-layer woven fabric. Further, the carbon fiber woven fabric 26 has a shape substantially following the carbon fiber woven fabric 24, and has a bottom portion 26A, vertical wall portions 26B and 26C, and flange portions 26D and 26E, similarly to the carbon fiber woven fabric 24. However, at the center of the bottom portion 26A in the vehicle front-rear direction, a folded-back portion 26F that is bent and folded back toward the vehicle is formed. The height of the folded-back portion 26F in the vehicle vertical direction is set to be the same as the height of the flange portions 26D and 26E.

The carbon fiber woven fabric 28 arranged on the carbon fiber woven fabric 26 is a multi-layer weave. The carbon fiber woven fabric 28 has a flat plate shape, and both end portions 28A, 28B and the central portion 28C in the vehicle front-rear direction are located on the flange portions 26D, 26E and the folded-back portion 26F of the carbon fiber woven fabric 26, respectively. It is laminated on the fiber fabric 26.

The carbon fiber woven fabrics 24, 26 and 28 thus laminated have the flange portions 24D and 26D and the end portion 28A sewn together. Similarly, the flange portions 24E and 26E and the end portion 28B are sewn together. Further, the carbon fiber woven fabrics 26 and 28 are sewn together at the folded portion 26F and the central portion 28C. The sewn portions are referred to as stitched portions 30A, 30B and 30C, respectively.

When it is assumed that the roof center RF20 is bent and deformed (flexed) toward the vehicle upper side along the vehicle width direction (axial direction) at the time of a side collision of the vehicle (see FIG. 2, moment M). All the sutured portions 30A to 30C are located on the vehicle upper side with respect to the neutral plane NS (neutral axis) of the bend passing through the centroid C.

In the roof center RF 20 (body frame reinforcing member 10), the carbon fiber woven structures 24, 26, 28 are laminated and sewn together to form the carbon fiber woven structure 32, and then the carbon fiber woven structure 32 is impregnated with resin. It is manufactured by being.

(Action)
The operation of the roof center RF 20 configured as above will be described.

Due to a side collision of the vehicle on which the roof center RF20 is arranged, the roof center RF20 is bent and deformed so as to bend upward in the vehicle along the vehicle width direction (see the moment M in FIG. 2). Therefore, the neutral plane NS (neutral axis). The tensile bending stress acts on the vehicle upper side and the compressive bending stress acts on the vehicle lower side.

Here, in the roof center RF20, since all the sewn portions 30A to 30C are arranged on the vehicle upper side of the neutral plane NS, tensile bending stress acts on all the sewn portions 30A to 30C. Therefore, as compared with the case where compressive bending stress acts on the sewn portions 30A to 30C, it is prevented or suppressed that any of the sewn portions 30A to 30C becomes the starting point of the breakage, and the roof center RF20 has a predetermined bending strength. It can be avoided that the

That is, even when a plurality of carbon fiber woven fabrics 24, 26, 28 are sewn together in the stacking direction and impregnated with a resin, the body frame reinforcing member 10 having a closed cross-section structure is manufactured and applied to the roof center RF 20. The roof center RF 20 can ensure a predetermined bending strength.

(variation)
The cross-sectional shape of the roof center RF 20 (body frame reinforcing member 10) is not limited to this embodiment. Hereinafter, a body skeleton reinforcing member according to another example will be shown. In these body skeleton reinforcing members, the same components as those of the body skeleton reinforcing member 10 are designated by the same reference numerals, and detailed description thereof will be omitted.

For example, like the body skeleton reinforcing member 10A shown in FIG. 3, two folded portions 26F and 26G are provided on the bottom portion 26A of the carbon fiber woven fabric 26, and both ends 28A and 28B of the carbon fiber woven fabric 28 and the flange of the carbon fiber woven fabric 26 are provided. The parts 26D and 26E are sewn together (sewn parts 30A and 30B), and the central part 28C of the carbon fiber woven fabric 28 and the folded parts 26F and 26G of the carbon fiber woven fabric 26 are sewn together (sewn parts 30C and 30D). Is also good.

Alternatively, as in the body skeleton reinforcing member 10B shown in FIG. 4, the flange portions 26D and 26E of the carbon fiber woven fabric 26 are bent to the folded-back portion 26F side (inside), and the flange portions 26D and 26E and the carbon fiber woven fabric 28 are Both ends 28A and 28B may be sewn together (sewn portions 30A and 30B).

Further, as in the body skeleton reinforcing member 10C shown in FIG. 5, the carbon fiber woven fabric 28 has the same shape as the carbon fiber woven fabric 26, and the carbon fiber woven fabrics 26, 28 are opposite to each other so that the folded portion 28I faces the folded portion 26F. A shape in which the layers are stacked in the direction is considered.

In this case, the flange portions 26D and 26E of the carbon fiber woven fabric 26 and the flange portions 28G and 28H of the carbon fiber woven fabric 28 are sewn together (sewn portions 30A and 30B), and the folded portion 26F and the carbon fiber of the carbon fiber woven fabric 26 are sewn together. The folded portion 28I of the fabric 28 has a structure in which the folded portions 28I are sewn together (sewn portion 30C).

Further, as in the body skeleton reinforcing member 10D shown in FIG. 6, the carbon fiber woven fabric 26 is configured such that the flange portions 26D and 26E are bent toward the folded-back portion 26F side (inside), and the carbon fiber woven fabric 28 is also changed to the carbon fiber woven fabric 26. Substantially similarly, it is configured to have a bottom portion 28D, vertical wall portions 28E and 28F, and flange portions 28G and 28H folded back inward. However, in the body skeleton reinforcing member 10D, the folded-back portion 26F of the carbon fiber woven fabric 26 extends to the bottom portion 28D of the carbon fiber woven fabric 28, and the folded-back portion 26F and the bottom portion 28D are sewn together to form a sewn portion 30C. A closed cross-section structure is formed.

Further, like the body skeleton reinforcing member 10E shown in FIG. 7, it is composed of a carbon fiber woven fabric 26 having a hat-shaped cross section and a flat carbon fiber woven fabric 28, and the flange portions 26D and 26E of the carbon fiber woven fabric 26 and the carbon fiber Both ends 28A and 28B of the fabric 28 are sewn together to form stitched portions 30A and 30B. As described above, the body skeleton reinforcing member 10E may have a closed cross-section structure with no folded portion.

(Other)
In the present embodiment, an example in which the body frame reinforcing member is applied to the roof center RF has been described, but the present invention is not limited to this. The body frame reinforcing member may be a body frame component other than the roof center RF. For example, a door impact beam, a door belt line reinforcement, a floor cross member, a bumper reinforcement, an A pillar, and the like can be considered.

Further, in the present embodiment, the case where the roof center RF20 is bent and deformed (flexed) toward the vehicle upper side at the time of a side collision of the vehicle has been described. Therefore, the stitching portion 30A is provided on the vehicle upper side from the neutral surface NS of the roof center RF20. Although all 30C are arranged, when the bending (deflection) direction is, for example, the vehicle lower side, all the stitched portions are located on the vehicle lower side than the neutral plane NS.

Similarly, when the body skeleton reinforcing member is applied to another body skeleton component and the bending (deflection) direction is, for example, the vehicle rear side, only on the vehicle rear side with respect to the neutral surface of the body skeleton reinforcing member. The sutured portion is located.

Furthermore, in the present embodiment, the reinforced woven fabric used for the body skeleton reinforcing member is a carbon fiber woven fabric, but a reinforced woven fabric other than carbon fiber may be used.

Further, the reinforcing fabric may be a non-woven fabric or a UD tape.

10, 10A, 10B, 10C, 10D, 10E Body frame reinforcing member 20 Roof center RF (body frame reinforcing member)
24 carbon fiber woven fabric 26 carbon fiber woven fabric 28 carbon fiber woven fabric 30A to 30C stitched portion NS neutral surface

Claims (1)

A carbon fiber woven structure having a closed cross-section structure that is formed by laminating a plurality of carbon fiber woven fabrics and stitching the plurality of carbon fiber woven fabrics together in the laminating direction by impregnating a resin into an integrated body skeleton reinforcement A member,
The sewn portion is provided only on the side where a tensile bending stress acts from the neutral surface of the body skeleton reinforcing member during bending deformation.