KR101868512B1

KR101868512B1 - Press forming method of fiber reinforced composite

Info

Publication number: KR101868512B1
Application number: KR1020160167190A
Authority: KR
Inventors: 이찬주; 이정민; 김동언; 김형익; 최호준
Original assignee: 한국생산기술연구원
Priority date: 2016-12-09
Filing date: 2016-12-09
Publication date: 2018-06-19

Abstract

According to the present invention, provided is a press forming method of a fiber reinforced composite, which comprises the following steps: a prepreg laminate preparation step for preparing a prepreg laminate by laminating a plurality of prepregs; a clip insert fixing step for fixing the prepreg laminate using a clip insert; and a press forming step for press-forming the prepreg laminate to which the clip insert is fixed, wherein the clip insert fixed to the prepreg laminate comprises a cover part covering one surface of the prepreg laminate, and a plurality of leg parts extending from the cover part to pass through the prepreg laminate and bent at the ends thereof. It is an object of the present invention to provide the press forming method of the fiber-reinforced composite material capable of preventing interlayer separation during press forming of a carbon fiber-reinforced composite and minimizing distortion of carbon fibers.

Description

TECHNICAL FIELD [0001] The present invention relates to a press forming method of a fiber reinforced composite material,

The present invention relates to a press forming method, and more particularly, to a press forming method of a fiber reinforced composite material.

Generally, press-molding of a carbon fiber-reinforced composite material is performed by laminating a plurality of carbon fiber prepregs, pressing them to produce a prepreg laminate, placing the heated prepreg laminate on a mold, and press molding. An important problem encountered in such conventional press forming processes is that delamination occurs in the press forming process. In addition, the properties of the carbon fiber reinforced composite material vary greatly depending on the direction of the carbon fiber, and there is also a problem that the properties of the carbon fiber are distorted due to the distortion of the carbon fiber arrangement during the press molding.

An object of the present invention is to provide a press molding method of a fiber-reinforced composite material capable of preventing interlayer separation during press forming of a carbon fiber-reinforced composite material and minimizing distortion of carbon fibers.

According to an aspect of the present invention,

A prepreg laminate preparing step of preparing a prepreg laminate by laminating a plurality of prepregs; A clip insert fixing step of fixing the prepreg laminate using a clip insert; And a press forming step of press-molding the prepreg laminate to which the clip insert is fixed, wherein the clip insert fixed to the prepreg laminate comprises a lid portion covering one surface of the prepreg laminate, And a plurality of legs extending from the prepreg laminate through the prepreg laminate and bent at ends thereof.

The clip insert fixing step may include positioning the prepreg laminate prepared in the preparation step of the prepreg laminate on the support die and disposing the clip insert so that the leg portion of the clip insert faces the upper surface of the prepreg laminate, And pressing the insert toward the prepreg laminate using a punch.

The support die may have a plurality of deformation inducing grooves formed corresponding to the plurality of leg portions.

The lid part may be in the form of a line segment or a single closed curve.

The prepreg may be a prepreg containing carbon fibers.

According to the present invention, all of the objects of the present invention described above can be achieved. Specifically, press-molding is performed in a state in which the carbon fiber prepreg laminate is fixed by a clip insert, so that delamination that may occur during the press molding process is prevented and distortion of the carbon fiber arrangement is minimized, have.

1 is a flowchart showing a press molding method of a fiber-reinforced composite material according to an embodiment of the present invention.
FIG. 2 is a view showing a prepreg laminate prepared through the preparation step of the prepreg laminate of FIG. 1. FIG.
Figs. 3 and 4 are process drawings illustrating the clip insert fixing step shown in Fig.
5 is a perspective view showing the clip insert shown in Figs. 3 and 4. Fig.

Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing a press molding method of a fiber-reinforced composite material according to an embodiment of the present invention. Referring to FIG. 1, a press-forming method of a fiber-reinforced composite material according to an embodiment of the present invention includes a prepreg laminate preparing step (S10) and a prepreg laminate preparing step (S10) A clip insert step (S20) of fixing the clip insert to the clip insert, and a press forming step (S30) of press-forming the prepreg laminate to which the clip insert is fixed through the fixing step.

In the prepreg laminate preparation step (S10), a prepreg laminate is prepared. The prepreg laminate preparing step (S10) is carried out by pressing a plurality of stacked prepregs in a heated state. Fig. 2 shows the prepreg laminate prepared by the preparation step (S10) of the prepreg laminate. Referring to FIG. 2, the prepreg laminate 100 includes a plurality of prepregs 110 stacked. In this embodiment, the prepreg 110 is a prepreg containing carbon fibers. After the prepreg laminate is prepared through the prepreg laminate preparation step (S10), the clip insert fixing step is performed.

In the clip insert fixing step S20, the clip insert is fixed to the prepreg laminate (100 in Fig. 2). FIGS. 3 and 4 illustrate in sequence the process of fixing the clip insert (S20). FIG. 5 shows a clip insert 130 secured to the prepreg laminate (100 of FIG. 2) have. The process of fixing the clip insert (S20) is as follows.

3, the prepreg laminate 100 is placed on a support die 120 having a flat top surface, and the clip insert 130 is placed on the prepreg laminate 100. As shown in Fig. The clip insert 130 is made of a metal and has a lid portion 131 and a plurality of leg portions 132 extending downward from the lid portion 131. The lid portion 131 has a shape in which the wire rod forms a square. However, the present invention is not limited to the shape of the cover portion 131, but may be in the form of a single closed curve other than a square or in the form of a line segment. The plurality of leg portions 132 extend in one direction perpendicular to the lid portion 131 at the corner of the lid portion 131 of the square shape. The plurality of leg portions 132 may be appropriately spaced from the lid portion 131 and the position thereof may be variously changed according to the shape of the lid portion 131. [ 3, the clip insert 130 is disposed such that an end of the leg portion 132 comes into contact with the upper surface of the prepreg laminated body 100. As shown in FIG. On the upper surface of the support die 120, a plurality of deformation inducing grooves 121 for deformation of the leg portions 132 of the clip insert 130 are formed. The plurality of deformation inducing grooves 121 are formed in correspondence with the plurality of leg portions 132 of the clip insert 130 in a one-to-one correspondence to induce deformation of the leg portions 132. 3, when the clip insert 130 is pressed toward the prepreg laminate 130 by using the punch 140, each of the plurality of leg portions 132 penetrates and passes through the prepreg laminate 100 The tip portion of the leg portion 132 is bent by the deformation inducing groove 121 formed in the support die 120 so that the clip insert 130 is fixed to the prepreg laminate 100 do. After the clip insert fixing step S20 is completed, a press forming step is performed.

In the press forming step S30, press forming is performed on the prepreg laminate to which the clip insert is fixed through the clip insert fixing step S20. The press forming performed in the press forming step S30 is a method commonly used in the press forming of the fiber reinforced composite material, so that detailed description thereof will be omitted. Since the prepreg laminate 100 is fixed by the clip insert 130, delamination is prevented in the press forming step, and distortion of the carbon fiber arrangement in the press forming process can be minimized.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

100: prepreg laminate
110: prepreg
120: support die
121:
130: Clip insert
131:
132: leg
140: punch

Claims

A prepreg laminate preparation step of preparing a prepreg laminate by laminating a plurality of prepregs including carbon fibers;
A clip insert fixing step of fixing the prepreg laminate using a clip insert; And
And a press forming step of press-molding the prepreg laminate to which the clip insert is fixed,
The clip insert fixed to the prepreg laminate includes a lid portion covering an upper surface of the prepreg laminate and a plurality of leg portions extending from a lower edge of the lid portion and passing through the prepreg laminate, Respectively,
The prepreg laminate preparation step is performed by pressing the stacked prepregs in a heated state,
The clip insert securing step comprises:
The clip insert is disposed such that the leg portion of the clip insert faces the upper surface of the prepreg laminate in a state where the prepreg laminate is placed on a support die formed on the upper surface of the plurality of deformation inducing grooves, The end of the leg is bent by the deformation inducing groove in the process of pressing the insert toward the prepreg laminate,
Wherein the interlaminar separation is prevented during the press forming step and warping of the carbon fiber arrangement is minimized during the press forming process.

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The method according to claim 1,
Wherein the lid portion is a line segment made of a wire material or a single closed curve shape.

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