KR20190018307A - Air bag housing for automobile and manufacture method of thereof - Google Patents

Abstract

And more particularly, to a vehicle air bag housing including a laminated continuous fiber reinforced composite material (L-CFT) and a method of manufacturing an air bag housing for a vehicle.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an air bag housing for a vehicle,

And more particularly, to a vehicle air bag housing including a laminated continuous fiber reinforced composite material (L-CFT) and a method of manufacturing an air bag housing for a vehicle.

The automotive industry is working to improve automobile fuel efficiency in line with global CO2 emission reduction trends. As a result, automobile parts materials are being used as plastic parts instead of steel. As a result, polypropylene, which is characterized by low specific gravity, excellent formability, heat resistance and chemical resistance, Have been widely used as materials for instrument panels and the like.

Among the automobile parts materials, the airbag housing is required to have impact resistance against high pressure when the airbag is deployed. The existing airbag housing is mainly made of steel material, which is heavy compared with other materials and may cause a bell mouth malfunction that causes the housing to open when the airbag is deployed.

In addition, by forming the airbag housing with a steel material, mold design cost and material cost are increased, and when the collision energy is not absorbed by the airbag cushion in a high-speed collision, there is a problem that the occupant's injury may be increased.

In order to solve such a problem, recently, a fiber reinforced composite material has been applied to an airbag housing. For example, a method of injection-molding a fiber-reinforced composite material by using a steel material or a weaving-type fiber-reinforced composite material as an insert material is being studied. However, when these materials are used as the insert material, the effect of weight reduction is insufficient and injection molding is difficult in a complicated shape, so that an increase in the process cost is inevitable and the degree of freedom in molding is remarkably lowered.

An object of the present invention is to provide a method of manufacturing an air bag housing for a vehicle, which can secure excellent strength and rigidity, and at the same time, can achieve molding freedom, dimensional stability, and cost reduction.

It is still another object of the present invention to provide a vehicle airbag housing manufactured by a method of manufacturing an airbag housing for a vehicle, which not only has excellent strength and rigidity, but also increases dimension stability and molding degree and minimizes cost increase.

In one embodiment of the present invention, there is provided a method of producing a laminated continuous fiber reinforced composite material (L-CFT), comprising: (a) laminating a continuous fiber reinforced composite material (CFT) comprising a thermoplastic resin and continuous fibers; (b) preheating the laminated continuous fiber reinforced composite material (L-CFT); And (c) inserting the preheated laminated continuous fiber reinforced composite material (L-CFT) into an injection mold and injection-molding a fiber reinforced composite material (FT) comprising a thermoplastic resin and fibers. A method of manufacturing a housing can be provided.

In another embodiment of the present invention, a vehicle airbag housing manufactured by the above-described method for manufacturing an airbag for a vehicle and satisfying the following formula 1 can be provided.

1.0? G? ₁ / G? ₂ ? 5.0 [Formula 1]

(G ₁ / G ₂ in the above formula 1 represents the ratio of the fiber reinforcement contained in the fiber reinforced composite material (FT) to the fiber reinforcement contained in the laminated continuous fiber reinforced composite material (L-CFT) The content of the fiber reinforcement contained in the composite material (L-CFT) is divided by the content of the fiber reinforcement contained in the fiber reinforced composite material (FT).)

The method for manufacturing an air bag housing for a vehicle according to the present invention is characterized in that injection molding is performed using a laminated continuous fiber reinforced composite material (L-CFT) as an insert material to improve moldability, dimensional stability, and cost reduction The airbag housing for a vehicle can be manufactured.

1 is a flowchart showing a method of manufacturing an air bag housing for a vehicle according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art to which the invention pertains. Only. Like reference numerals refer to like elements throughout the specification.

In one embodiment, a method of manufacturing an airbag housing for a vehicle according to the present invention comprises:

(S10) a laminated continuous fiber reinforced composite material (L-CFT) by laminating a continuous fiber reinforced composite material (CFT) comprising a thermoplastic resin and continuous fibers;

(b) preheating (S20) the laminated continuous fiber reinforced composite material (L-CFT); And

(c) inserting the preheated laminated continuous fiber reinforced composite material (L-CFT) into an injection mold and injection molding (S30) a fiber reinforced composite material (FT) comprising a thermoplastic resin and fibers A method of manufacturing an air bag housing for a vehicle can be provided.

The vehicle airbag housing can be manufactured by injecting a laminated continuous fiber reinforced composite material (L-CFT) into an insert material through a fiber reinforced composite material (FT) through the method for manufacturing the airbag housing for a vehicle.

More specifically, by forming a laminated continuous fiber reinforced composite material (L-CFT) by laminating a plurality of continuous fiber reinforced composite materials (CFT), injection-molding a fiber reinforced composite material (FT) It is possible to manufacture a vehicle air bag housing which not only has excellent strength and rigidity but also contributes to mold freedom degree, dimensional stability, and cost reduction.

1 is a flowchart showing a method of manufacturing an air bag housing for a vehicle according to an embodiment of the present invention. Referring to FIG. 1, the step (a) includes a step (S10) of producing a laminated continuous fiber reinforced composite material (L-CFT) by laminating a continuous fiber reinforced composite material (CFT) comprising a thermoplastic resin and continuous fibers, to be.

The continuous fiber reinforced composite material (CFT) may include a thermoplastic resin and a fiber reinforcement in the form of a continuous fiber.

The thermoplastic resin may be selected from at least one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile butadiene styrene copolymer . More preferably, at least one of PP (polypropylene), PA (polyamide), and combinations thereof is selected, and it is easy to impregnate the fiber reinforcing material, and strength and rigidity can be improved.

The continuous fibers include at least one fiber reinforcement selected from the group consisting of glass fibers, carbon fibers, and combinations thereof. The continuous fibers include at least one fiber reinforcing material selected from the group consisting of glass fibers, carbon fibers, and combinations thereof, to improve the strength and rigidity of the air bag housing for a vehicle, .

At this time, the continuous fiber means that the continuous fiber is present in a continuous form within the interior of the air bag housing, depending on the final size of the manufactured air bag housing. For example, the continuous fibers can be produced in a continuous process, such as continuous fibers in a UD sheet, and by continuously supplying the continuous fibers to the continuous process, a continuous fiber reinforced composite material (CFT). ≪ / RTI >

Accordingly, the continuous fiber reinforced composite material (CFT) may be made of a product having a specific shape such as a sheet. In such a product such as a sheet, the continuous fiber has a certain range of length depending on the shape of the product. However, the length of such a specific range should be regarded as having 'continuity' in that it can be arbitrarily adjusted in the manufacturing process in which continuous fibers are continuously fed, and most of the continuous fibers such as UD sheets or continuous fibers in the fabric , It has continuity without breaking inside the product.

The continuous fiber reinforced composite material (CFT) may include 40 to 50% by weight of the thermoplastic resin and 50 to 60% by weight of continuous fibers. When the continuous fibers are contained in the range below the above range, it is difficult to secure the strength and rigidity required in the airbag housing for a vehicle. If the continuous fibers are beyond the above range, the thermoplastic resin is not sufficiently impregnated, The manufacture of the air bag housing for a vehicle may cause a problem that is impossible in itself.

The cross-section of the continuous fibers may have an average diameter of from about 15 占 퐉 to about 20 占 퐉, for example, from about 16 占 퐉 to about 19 占 퐉. By maintaining the average diameter of the continuous fibers in the above range, excellent strength and rigidity can be achieved even in the above range, and the continuous fiber reinforced composite material (CFT) produced therefrom can exhibit appropriate thickness and physical properties.

Although the number of laminated continuous fiber reinforced composite materials (L-CFT) in the step (a) is not limited, it is preferable to laminate at least three continuous fiber reinforced composite materials (CFT) Composite material (L-CFT) can be manufactured. Preferably from 3 to 15 sheets, more preferably from 5 to 10 sheets, because it is possible to realize excellent strength and rigidity as an insert material. When stacking less than three sheets, sufficient strength and rigidity can not be realized, and if more than 15 sheets are stacked, a problem of increased process cost due to cost increase may occur.

The laminated continuous fiber reinforced composite material (L-CFT) may form a pattern in which a single continuous fiber reinforced composite material (CFT) is laminated at at least one angle selected from the range of 0 to 90 degrees. The stacked patterns may be laminated by the same or different stacked sheets of continuous fiber reinforced composite materials (CFT). For example, when 10 continuous fiber reinforced composite materials (CFT) are laminated, five sheets may be stacked at 0 degree (degrees), and the remaining five sheets may be stacked at 90 degrees (orthogonal). In addition, they may be laminated so as to cross each other at 0 degree (degrees), +45 degrees (degrees), 90 degrees (degrees), -45 degrees (degrees), and 0 degrees (degrees).

The step (b) is a step (S20) of preheating the laminated continuous fiber reinforced composite material (L-CFT).

The preheating temperature is preferably 200 to 230 占 폚, more preferably 220 to 230 占 폚, which is effective in improving workability. When the preheating temperature is less than 200 ° C, the preheating is not sufficiently performed, and the bonding strength between the laminated continuous fiber reinforced composite material (L-CFT) and the fiber reinforced composite material (FT) may be lowered. The reinforced composite material (L-CFT) is deteriorated, and the strength and rigidity of the reinforced composite material (L-CFT) may be deteriorated when manufacturing the air bag housing for a vehicle.

The thickness of the laminated continuous fiber reinforced composite material (L-CFT) may be 0.9 to 4.5 mm, and more preferably 1.5 to 3.0 mm. It is preferable to have a thickness range of the above range in order to have sufficient strength and rigidity in utilizing the insert as an insert material for a vehicle airbag housing.

When the thickness of the laminated continuous fiber reinforced composite material (L-CFT) is less than 0.9 mm, the strength and stiffness of the insert material may be lowered and the durability of the final vehicle air bag housing may be deteriorated. There is a fear that the property may deteriorate.

The step (c) is a step (S30) of inserting the preheated laminated continuous fiber reinforced composite material (L-CFT) into an injection mold and injection molding a fiber reinforced composite material (FT) comprising a thermoplastic resin and fibers .

(L-CFT) by injecting a fiber-reinforced composite material (FT) in a composition state into an injection mold having a laminated continuous fiber reinforced composite material (L-CFT) preheated through an extruder or the like. It is possible to realize excellent strength and rigidity with excellent bonding force, excellent dimensional stability, and various appearance can be expressed, thereby improving the degree of molding freedom.

The fiber reinforced composite material (FT) may include a thermoplastic resin and a fibrous reinforcement in the form of fiber.

The thermoplastic resin may be selected from at least one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile butadiene styrene copolymer . More preferably, at least one of PP (polypropylene), PA (polyamide), and combinations thereof is selected, and it is easy to impregnate the fiber reinforcing material, and strength and rigidity can be improved.

The fibers included in the fiber reinforced composite material (FT) are included in order to improve the strength and rigidity of the airbag housing for a vehicle, And combinations thereof. The term " fiber reinforcing material "

The fiber reinforced composite material (FT) may include 60 to 80% by weight of the thermoplastic resin and 20 to 40% by weight of the fibers. When the fiber is included in the range below the above range, it is difficult to secure the strength and rigidity required in the airbag housing for a vehicle, and in the case of exceeding the above range, the fluidity is lowered and the degree of freedom of molding may decrease.

The average length of the fibers is not limited, but is preferably 5 to 50 mm, and more preferably 10 to 40 mm, which is effective in improving the strength and rigidity without decreasing the fluidity during injection molding. When the length of the average fiber is less than 5 mm, the viscosity of the fiber-reinforced composite material (FT) composition to be injected is too high to lower the formability. When the average fiber length is more than 50 mm, the mechanical properties of strength and stiffness may deteriorate.

The injection temperature is preferably 200 to 230 占 폚, more preferably 220 to 230 占 폚, which is advantageous in that it is easy to mold the air bag housing for a vehicle because of excellent processability. If the injection temperature is less than 200 ° C, the bonding strength between the laminated continuous fiber reinforced composite material (L-CFT) and the fiber-reinforced composite material (FT) to be injected is insufficient, and the strength and rigidity of the vehicle air bag housing may be deteriorated. If the temperature is higher than 230 ° C, the fiber reinforced composite material (FT) may be deteriorated and the durability of the vehicle air bag housing may be deteriorated.

Another embodiment of the present invention is to provide a vehicle airbag housing which is manufactured according to the above-described manufacturing method and satisfies the following formula (1).

1.0? G? ₁ / G? ₂ ? 5.0 [Formula 1]

(G ₁ / G ₂ in the above formula 1 represents the ratio of the fiber reinforcing material contained in the fiber reinforced composite material (FT) to the fiber reinforcing material contained in the laminated continuous fiber reinforced composite material (L-CFT) The content of fiber reinforcement contained in reinforced composite material (L-CFT) is divided by the content of fiber reinforcement contained in fiber reinforced composites (FT).)

By controlling the above formula 1 in the above-described range, the strength and rigidity of the vehicle airbag housing can be improved more effectively. Particularly, when the value of G ₁ / G ₂ is less than 1.0, the content of the fiber reinforcing material contained in the fiber reinforced composite material (FT) becomes excessively high, so that it is difficult to reduce the weight of the product and the flowability thereof may be deteriorated. There is a possibility of decrease. When the value of G ₁ / G ₂ is more than 5.0, the content of the fiber reinforcing material contained in the fiber reinforced composite material (FT) is too small, so that sufficient strength and rigidity required for the vehicle air bag housing can not be achieved have.

In one embodiment, the impact strength of the automotive airbag housing according to the present invention may be from about 10 J / mm to about 100 J / mm. Specifically, the impact strength of the automotive airbag housing may be about 10 J / mm to about 50 J / mm, and more specifically about 10 J / mm to about 30 J / mm. The 'peak impact strength' is a 'surface impact strength' measured by an arbitrary object that is resistant to an instantaneous concentrated external force and is further measured on the surface of the object, and can be measured by the method of measuring an impact resistance according to ASTM D3763 have. If the fall impact strength is less than the above range, it is difficult to ensure sufficient impact performance, so that durability may deteriorate when the airbag is deployed. Therefore, such a structure is difficult to apply to parts requiring excellent impact performance, such as a vehicle airbag housing.

In one embodiment, the flexural strength of the automotive airbag housing according to the present invention can be from about 200 MPa to about 600 MPa, and in particular, from about 210 MPa to about 500 MPa. The flexural strength is the maximum strength generated from the specimen when the specimen is pressed at a constant speed and can be measured by the ASTM D790 method at room temperature 23 ° C.

In one embodiment, the flexural modulus of the vehicle airbag housing according to the present invention may be from about 10 GPa to about 50 GPa, and in particular, from about 10 GPa to about 40 GPa. Flexural modulus can be measured by the ASTM D790 method at room temperature 23 ° C as a measure of how much the material can be rolled without permanent deformation and fracture.

Therefore, the airbag housing for a vehicle of the present invention is manufactured by injection-molding a fiber reinforced composite material (FT) using the laminated continuous fiber reinforced composite material (L-CFT) as an insert material and has excellent strength and rigidity, Can also show improvement in dimensional stability.

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

< Example  And Comparative Example >

Example  One

Six continuous fiber reinforced composite materials (CFT) containing 40% by weight of a polypropylene homopolymer resin and 60% by weight of continuous fibers were laminated at 0 degree and pressed to form a 1.8 mm laminated continuous fiber reinforced composite material (L- CFT).

The laminated continuous fiber reinforced composite material (L-CFT) was preheated at 230 DEG C for 60 seconds and fixed to an injection mold. Into the injection mold, 70 wt% of polypropylene homopolymer resin and 30 wt% (L-CFT) was manufactured by injecting a fiber-reinforced composite material (FT) containing carbon fibers and carbon fibers in an amount of 0.1 to 5 wt.% And under pressure conditions of 230 DEG C and 350 tons. The properties were measured according to the evaluation method and are shown in Table 2.

Example  2

6 sheets of continuous fiber reinforced composite materials (CFT) were rotated at 0 degrees and 90 degrees (0 degrees) to form a cross lamination layer (0/90/0/0/90/0 or 90 / 0/90/90/0/90) to prepare a laminated continuous fiber reinforced composite material (L-CFT), the air bag housing for a vehicle was manufactured in the same manner as in Example 1, and the properties The results are shown in Table 2.

Example  3

As shown in the following Table 1, four sheets of continuous fiber reinforced composite materials (CFT) containing 40% by weight of a polyamide homopolymer resin and 60% by weight of continuous fibers were crossed at 0 degree and 90 degrees Laminated continuous fiber reinforced composite material (L-CFT) of 1.2 mm was prepared by lamination (0/90/90/0 or 90/0/0/90).

The laminated continuous fiber reinforced composite material (L-CFT) was preheated at 280 캜 for 60 seconds and then fixed in an injection mold. Into the injection mold, 60 wt% of a polyamide homopolymer resin and 40 wt% (L-CFT) was manufactured by injecting a fiber-reinforced composite material (FT) containing a polyolefin-based continuous fiber reinforced composite material (L-CFT) at a temperature of 280 DEG C and a pressure of 350 tons. The properties were measured according to the evaluation method and are shown in Table 2.

Comparative Example  One

As shown in the following Table 1, in the same manner as in Example 1 except that a weft-type continuous fiber reinforced composite material having a thickness of 1.8 mm was used as the insert material in place of the laminated continuous fiber reinforced composite material (L-CFT) The airbag housing was manufactured and physical properties were measured according to the following evaluation method, and it is shown in Table 2.

Comparative Example  2

As shown in the following Table 1, a fiber-reinforced composite material (FT) containing 60% by weight of a polypropylene homopolymer resin and 40% by weight of glass fibers (average length 30 mm) was injected as an injection resin without employing a separate insert material The air bag housing for a vehicle was manufactured in the same manner as in Example 1, and physical properties of the air bag housing were measured according to the following evaluation methods.

<Evaluation>

The properties of the airbag housing for a vehicle were evaluated according to the following experimental examples.

Experimental Example  1: Measurement of flexural strength and flexural modulus

The bending strength and flexural modulus of the airbag housing were measured at a room temperature of 23 DEG C according to the flexural property measurement method (ASTM D790 method). The results are shown in Table 2 below.

Experimental Example  2: Measurement of impact strength

The impact resistance of the automobile airbag housing was measured at a room temperature of 23 캜 according to the method of measuring the impact strength of the impact resistance (ASTM D3763 method). The results are shown in Table 2 below.

[Table 1]

[Table 2]

As shown in Table 2, in particular, Examples 2 to 3 were produced by injection molding a laminated continuous fiber reinforced composite material (L-CFT) into an insert material by a fiber reinforced composite material (FT) in a specific pattern to manufacture a vehicle air bag housing The mechanical strength and rigidity such as flexural strength, bending elastic modulus, and impact strength at the time of impact were improved, and at the same time, the degree of freedom of molding was improved, which proved to be effective for realizing a complicated shape.

In addition, it can be seen that the flexural characteristics and the impact strength are similar or superior to those of Comparative Example 1 in which a seamless continuous fiber-reinforced composite material is used as an insert material, and it can be seen that dimensional stability is similar in manufacturing the air bag housing for a vehicle I could.

As shown in Comparative Example 2, when the air bag housing for a vehicle was manufactured using only the fiber reinforced composite material (FT) without a separate insert material, it was found that the mechanical properties and the dimensional stability were remarkably deteriorated.

Claims (11)

(a) preparing a laminated continuous fiber reinforced composite material (L-CFT) by laminating a continuous fiber reinforced composite material (CFT) comprising a thermoplastic resin and continuous fibers;
(b) preheating the laminated continuous fiber reinforced composite material (L-CFT); And
(c) inserting the preheated laminated continuous fiber reinforced composite material (L-CFT) into an injection mold, and injection-molding a fiber reinforced composite material (FT) comprising a thermoplastic resin and fibers; Containing
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
The thermoplastic resin is selected from at least one of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), acrylonitrile butadiene styrene copolymer (ABS), and polycarbonate
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
Wherein the continuous fibers and the fibers comprise at least one member selected from the group consisting of glass fibers, carbon fibers, and combinations thereof
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
Wherein the continuous fiber reinforced composite material (CFT) comprises 40 to 50% by weight of the thermoplastic resin and 50 to 60%
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
Wherein the fiber reinforced composite material (FT) comprises 60 to 80% by weight of the thermoplastic resin and 20 to 40%
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
The preheating temperature of step (b) and the injection temperature of step (c)
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
The lamination of step (a) forms a pattern in which at least one angle selected from the range of 0 to 90 degrees (°) is laminated
A method of manufacturing an air bag housing for a vehicle.
The method according to claim 1,
The thickness of the laminated continuous fiber reinforced composite material (L-CFT) in the step (b) is 0.9 to 4.5 mm,
In the step (c), the length of the fibers is 5 to 50 mm
A method of manufacturing an air bag housing for a vehicle.
A process for producing a compound represented by the following formula 1, which is produced by a process according to any one of claims 1 to 8,
Automotive airbag housing.
1.0? G? ₁ / G? ₂ ? 5.0 [Formula 1]
(G ₁ / G ₂ in the above formula 1 represents the ratio of the fiber reinforcement contained in the fiber reinforced composite material (FT) to the fiber reinforcement contained in the laminated continuous fiber reinforced composite material (L-CFT) The content of the fiber reinforcement contained in the composite material (L-CFT) is divided by the content of the fiber reinforcement contained in the fiber reinforced composite material (FT).)
10. The method of claim 9,
Wherein the automotive airbag housing has an impact resistance as measured by ASTM D3763 of 10 J / mm to 100 J / mm.
10. The method of claim 9,
Wherein the vehicle airbag housing has a flexural modulus of 10 GPa to 50 GPa as measured according to ASTM D790 standard at a room temperature of 23 占 폚.

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