KR101944870B1 - Impact beam for car door - Google Patents

Abstract

The impact beam for an automotive door according to the present invention is formed by stacking at least one kind of prepreg selected from a glass fiber prepreg, a glass fiber fabric prepreg, a carbon fiber prepreg and a carbon fiber fabric prepreg, (1); And (i) a hybrid fabric prepreg comprising an aramid fiber prepreg, an aramid fabric prepreg, an aramid fiber and a carbon fiber, and a hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric on the inner layer (1) (Ii) an outer layer (2) having a laminated structure of aramid braid prepregs.
In the present invention, both the hollow inner layer (1) and the outer layer (2) are made of a prepreg material reinforced with fiber, so that the automobile can be lightened and the fuel consumption can be improved.
The present invention also relates to a method for producing an aramid fiber prepreg, wherein the outer layer (2) is composed of (i) prepregs containing aramid fibers or aramid fabrics excellent in vibration damping properties, and (ii) aramid braid prepregs and having impact resistance and bending strength Can be further improved.

Description

[0001] Impact beam for car door [0002]

The present invention relates to an impact beam for an automobile door, and more particularly, to an impact beam for an automobile door which is light in weight and which improves the automobile fuel economy, and at the same time, the outer layer is made of (i) aramid fibers or aramid fabrics And (ii) an aramid braid prepreg, which is excellent in impact resistance and bending strength against local loads at the same time.

The impact beam for a car door is supported and installed in a frame in the door of a vehicle, and absorbs and blocks impact energy when a side collision of an automobile, thereby protecting a vehicle occupant.

Hereinafter, in the present invention, a fiber reinforced resin, that is, a fiber polymer composite material is referred to as a "prepreg ".

Conventionally, a hollow metal rod has been widely used as an impact beam for an automobile door. However, the hollow metal rod has a heavy weight, resulting in a problem of low fuel efficiency of a vehicle.

As another shock absorbing rod for an automobile door (impact beam), Korean Utility Model Application No. 1996-21081 discloses a glass fiber polymer composite material (glass fiber prepreg) reinforced with glass fiber and a resin reinforced with carbon fiber Absorption reinforcing rods made of glass fiber prepregs and carbon fiber prepregs are formed on the center or right and left sides of a shock absorbing circular bar made of a carbon fiber polymer composite material (carbon fiber prepreg) .

However, since the impact beam does not include a metal material but is formed only of a prepreg material, the weight of the impact beam can be improved to improve the fuel efficiency of the automobile, but the impact resistance is lowered because the impact beam contains only glass fiber and carbon fiber having low vibration damping characteristics The inherent function of the impact beam is deteriorated.

Another conventional shock absorbing rod for an automobile door (impact beam) is disclosed in Korean Patent Laid-Open No. 10-2010-26005, wherein (i) a hollow aluminum rod and (ii) a unidirectional carbon fiber- And (iii) an external absorbing rod in which a fabric-like carbon fiber-reinforced composite material is laminated on the intermediate absorbing rod.

 However, since the impact beam includes a hollow aluminum rod, the weight of the impact beam is so low that the fuel efficiency of the vehicle is lowered, and the intermediate absorbing rod and the external absorbing rod include only carbon fibers having low vibration damping characteristics, .

As another conventional impact beam for an automobile door, Korean Patent Application No. 10-2012-83685 discloses a structure in which a hollow inner layer in which carbon fiber preforms are laminated and a prepreg including aramid fibers on the inner layer are stacked We propose an impact beam for a car door composed of layers.

The prior art is superior in impact resistance due to the outer layers including the aramid fibers having improved vibration damping characteristics and light weight, but the bending strength with respect to the local load applied to the impact beam is reduced, There is a problem in that the outer layer is in a circular shape, so that the area receiving the load due to the impact is small and the ductility is insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide an impact beam for an automobile door which is light in weight and which improves the fuel economy of an automobile and has excellent bending strength and impact resistance against local loads when the vehicle collides with a vehicle.

In order to achieve the above object, in the present invention, an impact beam for an automotive door is laminated with at least one selected from a glass fiber prepreg, a glass fiber fabric prepreg, a carbon fiber prepreg and a carbon fiber fabric prepreg, An inner layer (1) having a rectangular hollow structure; And (i) a hybrid fabric prepreg comprising an aramid fiber prepreg, an aramid fabric prepreg, an aramid fiber and a carbon fiber, and a hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric on the inner layer (1) (Ii) aramid braid prepregs, and (2) an outer layer (2) having a laminated structure.

In other words, in the present invention, the inner layer 1 is composed of the prepreg laminate as the above-described fiber polymer composite material, and satisfies the strength characteristics of the impact beam, which is a conventional steel material, while (i) A prepreg laminate comprising aramid fibers or aramid fabrics having excellent damping properties and (ii) an aramid braid prepreg to improve impact resistance and bending strength against local loads.

In the present invention, both the hollow inner layer (1) and the outer layer (2) are made of a prepreg material which is reinforced with fibers, fabrics and / or braids,

Further, the present invention is characterized in that the outer layer (2) is composed of (i) a prepreg including aramid fibers or aramid fabrics excellent in vibration damping characteristics, and (ii) an aramid braid prepreg so that the bending strength for impact resistance and local load Can be further improved.

1 is a perspective view of an impact beam for an automotive door according to the present invention;
2 is a schematic cross-sectional view of an impact beam for an automotive door according to the present invention.
3 is a schematic plan view of a hybrid fiber prepreg optionally included in the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the impact beam for an automobile door according to the present invention may include at least one prepreg selected from a glass fiber prepreg, a glass fiber fabric prepreg, a carbon fiber prepreg and a carbon fiber fabric prepreg, as shown in FIGS. 1 and 2 An inner layer (1) laminated and having a rectangular structure with a hollow interior; And (i) a hybrid fabric prepreg comprising an aramid fiber prepreg, an aramid fabric prepreg, an aramid fiber and a carbon fiber, and a hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric on the inner layer (1) (Ii) an outer layer (2) having a laminated structure of aramid braid prepregs.

Fig. 1 is a schematic perspective view of the present invention, and Fig. 2 is a schematic cross-sectional view of the present invention.

Both the inner layer 1 and the outer layer 2 can increase the area where the loads are concentrated in a quadrangular vehicle side collision.

Preferably, the aramid braid comprises 20 to 80% by weight of an aramid braid in which aramid fibers are braided, and 80 to 20% by weight of a thermosetting resin.

The aramid fiber prepreg preferably comprises 20 to 80% by weight of aramid fibers arranged in one direction and 80 to 20% by weight of the thermosetting resin.

The aramid fiber fabric prepreg preferably comprises 20 to 80% by weight of an aramid fabric and 80 to 20% by weight of a thermosetting resin.

It is preferable that the carbon fiber prepreg is composed of 20 to 80% by weight of the carbon fibers arranged in one direction and 80 to 20% by weight of the thermosetting resin.

The carbon fiber fabric prepreg is preferably composed of 20 to 80% by weight of the carbon fiber fabric and 80 to 20% by weight of the thermosetting resin.

The glass fiber prepreg preferably comprises 20 to 80% by weight of glass fibers arranged in one direction and 80 to 20% by weight of a thermosetting resin.

As shown in FIG. 3, the hybrid fiber prepreg H comprising aramid fibers and carbon fibers is composed of 20 to 80% by weight of aramid fibers and carbon fibers alternately arranged in one direction, 80 to 20% by weight of thermosetting resin %.

3 is a schematic plan view of the hybrid fiber prepreg (H).

Preferably, the hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric comprises 20 to 80 wt% of an aramid fabric and a carbon fiber fabric (based on the total amount) and 80 to 20 wt% of a thermosetting resin.

It is preferable that one direction of the aramid fibers constituting the aramid fiber prepreg coincides with the longitudinal direction of the impact beam for the automotive door.

It is preferable that one direction of the carbon fibers constituting the carbon fiber prepreg coincides with the longitudinal direction of the impact beam for the automotive door.

It is preferable that one direction of the glass fiber constituting the glass fiber prepreg coincides with the longitudinal direction of the impact beam for the automotive door.

It is preferable that one direction of the aramid fiber and the carbon fiber constituting the hybrid fiber prepreg H coincide with the longitudinal direction of the impact beam for the automotive door.

The fineness of the aramid fibers constituting the aramid fiber prepreg or the hybrid fiber prepreg H is 500 to 3,000 denier and the fineness of the carbon fibers constituting the carbon fiber prepreg or the hybrid fiber prepreg H is 300 ~ 30,000 denier is preferable.

The outer layer 2 may be formed only in the central portion of the inner layer 1 and may extend over the entire axial length of the reinforcing layer 2.

Next, a method for manufacturing an impact beam for an automotive door according to the present invention will be described in detail through embodiments and the like.

However, the scope of protection of the present invention is not limited to the following embodiments.

Example  One

A carbon fiber prepreg of 2,000 deniers arranged in one direction along the axial length of the quadrangular mandrel in one direction and consisting of 40% by weight of the carbon fibers and 60% by weight of epoxy resin, One step was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the carbon fibers in the carbon fiber prepreg coincided with the axial direction of the mandrel.

Next, 1,500 denier aramid fibers and 2,000 denier carbon fibers are alternately arranged in one direction on the central portion of the inner layer 1 formed on the mandrel by the first step, and the aramid fibers / carbon fibers (based on the total amount) The second step of winding the hybrid fiber prepreg (H) composed of 35% by weight and the epoxy resin 65% by weight and once with a thickness of 200 占 퐉 was repeated seven times and then 1,500 denier aramid fibers were wound on the braid The outer layer 2 was formed by repeating the step of winding the aramid braid prepreg, which is composed of 40% by weight of the aramid braid and 60% by weight of the thermosetting resin, in a Braid shape and having a thickness of 150 탆 once.

At this time, the arrangement direction of the carbon fibers and the aramid fibers in the hybrid fiber prepreg (H) coincided with the axial direction of the mandrel.

Next, the carbon fiber prepreg, the hybrid fiber prepreg (H) and the epoxy resin in the aramid braid prepreg are cured in a hot air oven, and then the prepreg laminated layer formed on the mandrel and the mandrel is separated to form an impact beam .

The average impact force (impact energy absorbing performance) for the impact beam manufactured as described above was measured by the side impact test method of the Federal Motor Vehicle Safety Standard (19.5 kN).

Example  2

A glass fiber prepreg of 2,000 deniers arranged in one direction along the axial length of the quadrangular mandrel in one direction and consisting of 40% by weight of the glass fiber and 60% by weight of epoxy resin, One step was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the glass fibers in the glass fiber prepreg coincided with the axial direction of the mandrel.

Next, 1,500 denier aramid fibers are arranged alternately in one direction on the central portion of the inner layer 1 formed on the mandrel by the first step, and the aramid fibers are composed of 35 wt% of the aramid fibers and 65 wt% of the epoxy resin, A second step of once winding the aramid fiber prepreg at 200 占 퐉 once was repeated seven times, and then 40% by weight of the aramid braid having 1,500 denier aramid fibers woven in a braid form and 60% by weight of the thermosetting resin, And the step of winding the aramid blade prepreg having a thickness of 150 탆 once was repeated three times to form the outer layer 2.

At this time, the alignment direction of the aramid fibers in the aramid fiber prepreg was made to coincide with the axial direction of the mandrel.

Next, the glass fiber prepreg, the aramid fiber prepreg and the epoxy resin in the aramid braid prepreg were cured in a hot air oven, and then the mandrel and the prepreg laminated layer formed on the mandrel were separated to produce an impact beam for an automobile door .

The average impact force (impact energy absorbing performance) of the impact beam thus manufactured was measured by the side impact test method of the Federal Motor Vehicle Safety Standard (18.8 kN).

Example  3

A carbon fiber prepreg of 2,000 deniers arranged in one direction along the axial length of the quadrangular mandrel in one direction and consisting of 40% by weight of the carbon fibers and 60% by weight of epoxy resin, One step was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the carbon fibers in the carbon fiber prepreg coincided with the axial direction of the mandrel.

Next, 35% by weight of an aramid fabric woven with aramid fibers of 1,500 denier and 65% by weight of an epoxy resin are formed on the entire longitudinal direction of the inner layer 1 formed on the mandrel by the first step, A second step of winding the aramid fabric prepreg once was repeated seven times. Then, aramid fibers of 1,500 denier were braided in a braid form and 40% by weight of the aramid braid and 60% by weight of the thermosetting resin And the step of winding the aramid braid prepreg having a thickness of 150 탆 once is repeated three times to form the outer layer 2.

Next, the carbon fiber prepreg, the aramid fabric prepreg, and the epoxy resin in the aramid braid prepreg were cured in a hot air oven, and then the mandrel and the prepreg laminated layer formed on the mandrel were separated to produce an impact beam for an automobile door .

The result of measuring the average reaction force (impact energy absorbing performance) for the impact beam thus manufactured by the side impact test method of the Federal Motor Vehicle Safety Standard was 20.2 kN.

Example  4

A carbon fiber prepreg of 2,000 deniers arranged in one direction along the axial length of the quadrangular mandrel in one direction and consisting of 40% by weight of the carbon fibers and 60% by weight of epoxy resin, One step was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the carbon fibers in the carbon fiber prepreg coincided with the axial direction of the mandrel.

Next, on the central portion of the inner layer 1 formed on the mandrel by the first step, 35 weight parts of aramid / carbon fiber fabric (based on the total amount) woven with 1,500 denier aramid fibers and 2,000 denier carbon fibers And a second step of winding the hybrid fabric prepreg having a thickness of 200 占 퐉 consisting of 65% by weight of an epoxy resin and 65% by weight of the epoxy resin once, was repeated seven times. Thereafter, 1,500 denier aramid fibers were woven in a braid form The step of winding the aramid braid prepreg, which consists of 40% by weight of the gin-aramid braid and 60% by weight of the thermosetting resin, once was repeated three times to form the outer layer 2.

Next, the carbon fiber prepreg, the hybrid fabric prepreg, and the epoxy resin in the aramid braid prepreg were cured in a hot air oven, and then the prepreg laminated layer formed on the mandrel and the mandrel was separated to produce an impact beam for an automobile door .

The average impact force (impact energy absorbing performance) of the impact beam manufactured as described above was measured by the side impact test method of the Federal Motor Vehicle Safety Standard (20.5 kN).

Comparative Example  One

A carbon fiber prepreg of 2,000 deniers arranged in one direction along the length of the mandrel in one direction and consisting of 40% by weight of the carbon fibers and 60% by weight of epoxy resin, The process was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the carbon fibers in the carbon fiber prepreg coincided with the axial direction of the mandrel.

Next, 3,000 denier glass fibers are arranged in one direction on the carbon fiber prepreg wound on the mandrel by the first step, and the thickness of the carbon fiber prepreg, which is composed of 35% by weight of the glass fiber and 65% by weight of the epoxy resin, The second step of winding the glass fiber prepreg once was repeated ten times to form the outer layer (2).

At this time, the arrangement direction of the glass fibers in the glass fiber prepreg coincided with the axial direction of the mandrel.

Next, the carbon fiber prepreg and the epoxy resin in the glass fiber prepreg were cured in a hot air oven, and then the prepreg laminated layer formed on the mandrel and the mandrel was separated to produce an impact beam for an automobile door.

The average reaction force (impact energy absorbing performance) of the impact beam thus manufactured was measured by the side impact test method of the Federal Motor Vehicle Safety Standard (11.9 kN).

Comparative Example  2

A carbon fiber prepreg of 2,000 deniers arranged in one direction along the axial length of the quadrangular mandrel in one direction and consisting of 40% by weight of the carbon fibers and 60% by weight of epoxy resin, One step was repeated ten times to form an inner layer (1). At this time, the arrangement direction of the carbon fibers in the carbon fiber prepreg coincided with the axial direction of the mandrel.

Next, 1,500 denier aramid fibers and 2,000 denier carbon fibers are alternately arranged in one direction on the central portion of the inner layer 1 formed on the mandrel by the first process, and the aramid fibers / carbon fibers (based on the total amount) And the second step of winding the hybrid fiber prepreg (H) composed of 35% by weight and epoxy resin 65% by weight once with a thickness of 200 占 퐉 was repeated 10 times to form an outer layer (2).

At this time, the arrangement direction of the carbon fibers and the aramid fibers in the hybrid fiber prepreg (H) coincided with the axial direction of the mandrel.

Next, the carbon fiber prepreg and the epoxy resin in the hybrid fiber prepreg (H) were cured in a hot air oven, and then the mandrel and the prepreg laminated layer formed on the mandrel were separated to produce an impact beam for an automobile door.

The average impact force (impact energy absorbing performance) of the impact beam thus manufactured was measured by the side impact test method of the Federal Motor Vehicle Safety Standard of the vehicle, which was 15.5 kN.

XX: Improve section
1: inner layer
2: Outer layer
H: Hybrid fiber prepreg
H1: a portion where the aramid fiber is arranged
H2: The part where the carbon fibers are arranged.

Claims (13)

An inner layer (1) having a rectangular structure in which one or more prepregs selected from a glass fiber prepreg, a glass fiber fabric prepreg, a carbon fiber prepreg and a carbon fiber fabric prepreg are laminated and hollow inside; And
(I) an aramid fiber prepreg, an aramid fabric prepreg, a hybrid fiber prepreg comprising an aramid fiber and a carbon fiber, and a hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric on the inner layer (1) (Ii) an outer layer (2) having a laminated structure of aramid braid prepregs (2). The automotive door according to claim 1, wherein the aramid braid prepreg comprises 20 to 80% by weight of aramid braid (aramid fibers) braided in a braid form and 80 to 20% of a thermosetting resin. Impact beam. The impact beam according to claim 1, wherein the aramid fiber prepreg comprises 20 to 80% by weight of aramid fibers arranged in one direction and 80 to 20% by weight of a thermosetting resin. The impact beam according to claim 1, wherein the aramid fabric prepreg comprises 20 to 80% by weight of an aramid fabric and 80 to 20% by weight of a thermosetting resin. The impact beam according to claim 1, wherein the carbon fiber prepreg comprises 20 to 80% by weight of carbon fibers arranged in one direction and 80 to 20% by weight of a thermosetting resin. The impact beam according to claim 1, wherein the carbon fiber fabric prepreg comprises 20 to 80% by weight of a carbon fiber fabric and 80 to 20% by weight of a thermosetting resin. The hybrid fiber preform according to claim 1, wherein the hybrid fiber prepreg comprising aramid fibers and carbon fibers is composed of 20 to 80% by weight of aramid fibers and carbon fibers (based on the total amount) alternately arranged in one direction and 80 to 20% by weight of thermosetting resins Features an impact beam for a car door. The hybrid textile prepreg according to claim 1, wherein the hybrid fabric prepreg comprising an aramid fabric and a carbon fiber fabric comprises 20 to 80% by weight of an aramid fabric and a carbon fiber fabric (based on the total amount) and 80 to 20% by weight of a thermosetting resin. Impact beam for door. The impact beam according to claim 2, wherein one direction of the aramid fibers constituting the aramid fiber prepreg coincides with the longitudinal direction of the impact beam for the automotive door. The impact beam according to claim 4, wherein one direction of the carbon fibers constituting the carbon fiber prepreg coincides with the longitudinal direction of the impact beam for the automotive door. The impact beam according to claim 6, wherein one direction of the aramid fiber and the carbon fiber constituting the hybrid fiber prepreg coincide with the longitudinal direction of the impact beam for the automotive door. The impact beam according to claim 1, characterized in that the outer layer (2) is formed only in the central portion of the inner layer (2). 2. Impact beam according to claim 1, characterized in that the outer layer (2) coincides with the longitudinal direction of the impact beam for the car door over the entire axial length of the inner layer (2).

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