KR20200050521A - Manufacturing method for preform and manufacturing method for composite using preform - Google Patents

Abstract

The present invention relates to manufacture of a plurality of preforms to be laminated. The plurality of preforms are manufactured in each jig, and an upper jig which molds an upper preform corresponds to a lower preform. Therefore, the preforms sequentially laminated for molding a composite material are formed in advance according to a shape of a molded product and then laminated, thereby precisely molding the shape of the composite material.

Description

Pre-form manufacturing method and composite material manufacturing method using preform {Manufacturing method for preform and manufacturing method for composite using preform}

The present invention relates to a preform manufacturing method and a composite material manufacturing method using the preform.

The composite material is simply a laminate composite in which two materials are laminated, a particle composite in which two constituent particles are mixed in a powder form, and a steel wire or fiber in a matrix material. ) Can be classified as a fiber reinforced composite planted in a specific direction. These composite materials have excellent specific strength, specific rigidity, fatigue resistance and corrosion resistance, which are differentiated from metallic materials, and are used in various fields such as aerospace, aviation, building structures, and energy.

To make a laminated composite material, first, a jig having a shape corresponding to the shape of the component to be molded is made. A plurality of fibers constituting the lower skin are stacked on the jig until a predetermined thickness, a core is stacked on the lower skin, and a plurality of fibers constituting the upper skin are stacked on the core until a predetermined thickness is obtained. In the state where the lower skin, the core, and the upper skin are stacked, the laminated composite is molded while resin is injected through a process of vacuum curing at high temperature and high pressure.

However, the shape of the lower skin is formed along the jig shape, but in the case of the upper skin, the stacked fibers are stretched or shrunk along the shape of one side of the core, thereby forming a shape corresponding to one side of the core. Accordingly, the fibers constituting the upper skin were cut in accordance with the shape of one surface of the core and the fibers were laminated on one surface of the core, but as the fibers were cut, the structural performance of the laminated composite material was deteriorated.

Registered Patent No. 10-1689569 (2016. 12. 20.) Registered Patent No. 10-1447136 (2014. 09. 26.)

The present invention provides a preform manufacturing method and a method of manufacturing a composite material using a preform, in which fibers to be laminated for molding a composite material are pre-formed and laminated according to the shape of a molded product.

A method of manufacturing a preform according to an embodiment of the present invention is to manufacture a plurality of preforms to be stacked, wherein the plurality of preforms are made of respective jigs, and the upper jig forming the upper preform corresponds to the lower preform.

Before forming the upper layer preform, the lower layer preform molded from the lower layer jig may be removed, and the upper layer jig may be disposed on the lower layer jig from which the lower layer preform is removed to form the upper layer preform.

The upper surface of the lower layer preform and the lower surface of the upper layer preform, which are molded and stacked, are in contact with each other, and the upper surface shape variable of the lower layer preform and the lower surface shape variable of the upper layer preform may have the same value.

The lower layer preform and the upper layer preform may be fibers or resins.

The lower layer preform and the upper layer preform may be molded by a vacuum bagging or press process.

The method of manufacturing a composite material according to an embodiment of the present invention comprises the steps of forming a lower layer preform by stacking fibers on a lower layer jig having a predetermined shape, and forming a upper layer preform by stacking fibers on the upper layer jig corresponding to the lower layer preform. , Sequentially stacking the lower layer preform and the upper layer preform into a mold and injecting resin into the mold.

According to an embodiment of the present invention, preforms that are sequentially stacked for forming a composite material are preformed to conform to the shape of a molded product, and then laminated, so that the shape of the composite product can be accurately implemented in the preform production step such as curved surfaces and corners. .

According to an embodiment of the present invention, since the fibers are preformed to fit the shape of a molded product in a state made of carbon fibers to form a single layer, the fibers are continuously connected, thereby maintaining structural performance. Accordingly, it is possible to prevent structural degradation that occurs when fibers are cut by fiber cutting.

According to an embodiment of the present invention, the top surface of the core on which the preform is placed is molded into a complex shape in consideration of the interface with other structures, and the preforms that are pre-formed in the same manner as the core are stacked on top of it, so that the preforms stacked with the core match As a result, damage to the core can be minimized.

1 is a block diagram showing a preform manufacturing method according to an embodiment of the present invention.
Figure 2 is a process diagram of Figure 1;
Figure 3 is a block diagram showing a preform manufacturing method according to another embodiment of the present invention.
4 is a process diagram of FIG. 3;
5 is a block diagram showing a method of manufacturing a composite material as a preform according to the embodiment of FIGS. 1 to 4.
6 is a process diagram of FIG. 5;
7 is a schematic view showing a state of manufacturing a molded article as a preform according to the embodiment of FIGS.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. The same reference numerals are used for similar parts throughout the specification.

Then, a method for manufacturing a preform according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1 is a process diagram showing a preform manufacturing method according to an embodiment of the present invention, Figure 2 is a block diagram of Figure 1;

Referring to Figures 1 and 2, the preform manufacturing method according to the present embodiment is to pre-process the fibers to be stacked for molding the composite material according to the shape of the molded product, the lower layer preform molding step (S10) and the upper layer preform molding step (S20) ). The lower layer preform and the upper layer preform are molded through each jig. The fiber has a predetermined thickness and width and can be a carbon fiber and can be molded into a preform through a vacuum bagging process. The lower layer preform and the upper layer preform may be laminated to a mold for molding a composite material. The fiber is not limited to carbon fiber and may be variously changed depending on the molded article.

For forming the lower layer preform 11, fibers are disposed on the lower layer jig 1 having a predetermined shape. The shape of the lower layer jig 1 corresponds to the surface shape of the mold for molding the molded article. Through the vacuum bagging process, the fibers are brought into close contact with the surface of the lower fixture 1 to form the lower preform 11 corresponding to the lower fixture 1.

For forming the upper layer preform 21, fibers are disposed on the upper layer jig 2 having a thickness and shape corresponding to the lower layer preform 11. Through the vacuum bagging process, the fibers are brought into close contact with the surface of the upper jig 2 to form the upper preform 21 corresponding to the upper jig 2. When the upper layer jig 2 has a thickness and shape corresponding to the lower layer preform 11, when the upper layer preform 21 molded through the upper layer jig 2 is formed, the shape variable value and the upper surface shape variable value of the lower layer preform 11 are same. Accordingly, if the lower surface of the upper layer preform 21 is disposed so as to contact the upper surface of the lower layer preform 11, the upper surface of the lower layer preform 11 and the lower surface of the upper layer preform 21 may coincide and be in close contact.

On the other hand, the lower layer preform 11 and the upper layer preform 11 so that the shape is not distorted and the upper layer preform 12 can be stacked smoothly when the upper layer preform 12 is stacked on the lower layer preform 11. ), Pinholes 11a and 21a are formed. Pinholes (11a, 21a) are formed through each jig (1, 2). That is, pin members 1a and 2a for forming the pinholes 11a and 21a are formed at the same positions of the lower layer jig 1 and the upper layer jig 2.

Accordingly, a reference member 31 inserted into the pinholes 11a and 21a is formed in the mold 3 (see FIG. 6) in which the molded preforms are stacked. Since the pinholes 11a and 21a of the preforms 11 and 21 to be stacked are located on the reference member 31 and located at the same place, the stacked preforms are not twisted and are stacked neatly and can be stacked at the correct position without being twisted. .

3 and 4, the preform manufacturing method may further include a lower layer preform removal step (S30) and an upper layer jig placement step (S40).

When the lower layer preform 11 is molded through the lower layer fixture 1, the lower layer preform 11 is removed from the lower layer fixture 1. The lower member 1 is formed with a pin member 1a for forming a pinhole in a preform.

The upper fixture 2 for forming the upper preform 21 is disposed on the lower fixture 1. At this time, a through hole 2b through which the pin member 1a passes is formed in the upper jig 2. The pin member 1a is exposed above the upper fixture 2.

Fibers are placed on the upper fixture (2) to mold the upper preform (21) through a vacuum bagging process. At this time, a pinhole 21a is formed in the upper layer preform 21 formed by the pin member 1a.

Since the upper layer jig 2 forming the upper layer preform 21 corresponds to the lower layer preform 11 on which the upper layer preform 21 is stacked and its thickness and shape, the lower layer preform 11 and upper layer preform 21 are mutually compatible. The value of the shape variable on the upper surface of the lower preform 11 and the value of the shape variable on the lower surface of the upper layer 21 are the same. Accordingly, the lower layer preform 11 and the upper layer preform 21 may be in close contact as a whole.

In the above description, only the lower layer preform and the upper layer preform are described, but the number of stacks of preforms may vary depending on the structure, thickness, and shape of the parts molded using the preform. Thus, the preform is molded through each jig corresponding to the number of stacks. Here, when the thickness of the fiber is less than 0.5 mm, a plurality of fibers may be stacked to form a plurality of fibers into one preform using one jig.

In addition, although it has been described as forming the preform through a vacuum bagging process, the preform can be formed by a press process according to the material of the fiber. The fibers used in the press process may be resins that require predetermined heat during molding. The resin can be thermoplastic.

Next, a method for manufacturing a composite material will be described with reference to FIGS. 5 and 6.

5 and 6, the composite material manufacturing method includes a lower layer preform forming step (S110), an upper layer preform forming step (S120), a preform laminating step (S130), and a resin injection step (S140).

Since the lower layer preform forming step (S110) and the upper layer preform forming step (S120) of the composite material manufacturing method according to the present embodiment are the same as the lower layer preform forming step and upper layer preform forming step of the preform manufacturing method according to the FIGS. Duplicate description will be omitted.

Each preform 11 and 21 molded through the lower layer preform molding step S110 and the upper layer preform molding step S120 are sequentially stacked on the mold 3 (S130). At this time, the preform is laminated in a plurality of layers according to the specifications of the molded parts. The preform of each layer is molded using each jig, and pinholes are formed in each preform.

The lower layer preform 11 is placed in the mold 3, and the upper layer preform 21 is disposed on the lower layer preform 11. At this time, since the shape of the upper surface of the lower layer preform and the shape of the lower surface of the upper layer preform correspond to each other, the contacting portions of the lower layer preform and the upper layer preform may be tightly coupled to each other. When the preforms are stacked according to the specifications of the parts to be molded, the resin 3 is injected into a mold in which the preforms are stacked through a vacuum bagging process to mold the composite material 3 (S140).

On the other hand, when laminating the preforms 11 and 12 to the mold 3, the pinholes 11a and 21a are positioned on the reference member 31 of the mold 3 to stack the preforms 11 and 12. The preforms 11 and 12 to be stacked may be stacked on the basis of the reference member 31 so that their shapes are not distorted and are stacked neatly.

On the other hand, the fibers forming the lower skin 41 are stacked on the mold 4 according to the molded parts using the composite material, and the core 42 in the form of foam or honeycomb is disposed on the fibers. In order to form the upper skin 43 on the core, the lower layer preform 11 and the upper layer preform 21 sequentially formed in the same shape as the core through the lower layer preform molding step S10 and the upper layer preform molding step S20 are sequentially formed. Stacked. At this time, as the lower pre-rom 11 and the upper pre-form 21 are sequentially stacked based on the pin member 4a coupled to the mold 4, the pre-forms can be stacked at the correct position without being distorted. Thereafter, the resin is injected through a vacuum bagging process to mold a component using a composite material (see FIG. 7).

The upper surfaces of the core 311 on which the lower layer preform 11 and the upper layer preform 21 are placed are molded into a predetermined shape, and the preforms formed in the same manner as the cores are stacked thereon, so that the cores and the preforms that are stacked coincide. Damage to (311) can be minimized.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1: Lower floor fixture 11: Lower floor preform
2: Upper fixture 21: Upper preform
3: Mold 31: Composite
41: lower skin 42: core
43: upper skin

Claims (6)

By manufacturing a plurality of preforms to be laminated,
The plurality of preforms are made of each jig, and the upper layer jig for forming the upper layer preform is a preform manufacturing method corresponding to the lower layer preform. In claim 1,
A method of manufacturing a preform for molding the upper layer preform by removing the lower layer preform molded from the lower layer jig before forming the upper layer preform, and placing the upper layer jig on the lower layer jig from which the lower layer preform was removed. In claim 1,
The upper surface of the lower layer preform and the lower surface of the upper layer preform that are molded and stacked are in contact with each other, and the upper surface shape variable of the lower layer preform and the lower surface shape variable of the upper layer preform have the same preform manufacturing method. In claim 1,
The lower layer preform and the upper layer preform is a fiber or resin preform manufacturing method. In claim 1,
The lower layer preform and the upper layer preform are pre-formed by a vacuum bagging or a press process. Forming a lower layer preform by laminating fibers on a lower layer jig having a predetermined shape,
Forming an upper layer preform by laminating fibers on the upper layer jig corresponding to the lower layer preform;
Sequentially stacking the lower layer preform and the upper layer preform in a mold, and
Injecting resin into the mold
Composite material manufacturing method comprising a.

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