KR20130105018A

KR20130105018A - Light-resin transfer molding apparatus for fiber-reinforced plastic having mold arrange unit

Info

Publication number: KR20130105018A
Application number: KR1020120027085A
Authority: KR
Inventors: 이상철; 홍순팔; 최원석
Original assignee: (주)선진오토텍
Priority date: 2012-03-16
Filing date: 2012-03-16
Publication date: 2013-09-25

Abstract

The resin transfer molding apparatus of the fiber-reinforced plastic using the upper and lower molds according to the present invention comprises: a lower mold having at least two vacuum grooves; An upper mold coupled to the lower mold upper side to form a complementary shape to form the vacuum groove; A resin injection valve for injecting resin into a space formed by engagement of the lower and upper molds; And at least one vacuum suction valve installed to remove air in the vacuum groove and the space; And an alignment unit protruding to a position complementary to the lower and upper molds, and having at least four paired pairs to guide the coupling positions of the lower and upper molds.

Description

Light-Resin Transfer Molding apparatus for Fiber-Reinforced Plastic having mold arrange unit

The present invention relates to an apparatus for conveying and molding a fiber-reinforced plastic, and more particularly, to a resin-transfer of a fiber-reinforced plastic using an upper and a lower mold capable of producing a product with minimal post-processing by using a pair of upper and lower molds. It relates to a molding apparatus.

Due to the continuous increase in oil prices and environmental pollution, research on high fuel consumption vehicles has been continuously conducted in recent years. In particular, electric vehicles, which have a significantly lower pollutant emission rate than gasoline or diesel engines, are in the spotlight as the next generation vehicle.

As well as the development of such an electric vehicle, the most important part in improving the fuel efficiency of the existing vehicle is to minimize the power consumption of the drive source due to the weight of the vehicle body by forming the vehicle body appearance with a light weight material while maintaining the rigidity to the maximum.

In particular, since steel-based body materials currently in use have limitations in weight reduction, a method for producing various parts for automobile bodies and automobiles using fiber-reinforced plastic resins (FRP) that are light, durable and excellent in recent years. Research is ongoing.

As described above, a fiber reinforced plastic (FRP) is typically proposed as a composite material as a steel substitute, and a hand ray using polyester, vinyl ester, epoxy resin, or the like is used to manufacture vehicle parts using such composite material. The HAND LAY UP method is generally used. This is a method of placing dry chopped strand mats one by one on the outer mold of the outer shape of the product, pouring a liquid resin on it, and then impregnating the resin in the fiber mat using a roller, followed by hardening, and molding. . This method is a manual process, which implies quality problems such as durability of the product and surface defects, and raises the cost of parts due to difficulty in mass production. In addition, since the quality of the product depends on the skill of the operator, there is a problem that it is difficult to ensure uniform quality, there is a limit in the amount of production.

A method developed to solve this problem is a resin transfer molding method. The RTM method places the preform of the product shape made of reinforcing fibers in the space between the molds having the outer shape of the product, and then closes the upper and lower molds and injects the resin at a high pressure using a resin injector. It is a method for producing a fiber-reinforced plastic of a desired shape by curing in the injected state.

This RTM method has the advantage of being able to produce a uniform product compared to the manual hand lay-up method.However, since the upper and lower shape forming materials are made of hard metal or wood, the part caught by the mold during the demoulding is damaged or deformed. It will have an undercut phenomenon. Therefore, it is difficult to produce a molded product that is deeply embedded or protrudes in either direction.

In addition, there is a need for a step of heating and drying the mold after the resin is injected into the heating furnace. During this process, no other work can be performed, and thus there is a problem in that productivity may decrease.

The present invention was conceived in view of the above, the productivity can be improved compared to the existing RTM method, the fiber using the upper and lower molds that can form a fiber-reinforced plastic products of various thicknesses using a single mold It is an object of the present invention to provide a resin transfer molding apparatus for reinforced plastics.

Another object of the present invention, when the upper and lower molds, the upper and lower molds can be combined at the correct position, and during the resin injection process, the shape of the space is changed while the mold is pushed out by the injection pressure of the resin is completed An object of the present invention is to provide a mold structure that can prevent a molded article from becoming defective.

The alignment unit may include: a guide protrusion having four of the lower molds protruding from each corner; And a guide groove recessed in a position corresponding to the guide protrusion of the upper mold.

In addition, the guide protrusion and the guide groove may be formed integrally with each of the lower and upper molds.

According to the present invention as described above, since the fiber-reinforced plastic is molded by using the upper and lower molds, the surface facing the mold can be formed smoothly, compared to the conventional hand layup process, the time required for post-processing products Can be reduced.

In addition, compared with the conventional RTM method, the upper and lower molds can be kept in close contact with each other through vacuum adsorption. And since only the lower mold can be put into the heating and drying process, it is possible to increase the production speed and production compared to the process using only one mold.

1 is a perspective view showing an example of a product molded by a fiber-reinforced plastic resin transfer molding method using the upper and lower molds according to the present invention,
2 is a cross-sectional view of the upper and lower molds for forming the product of FIG. 1, and
3 is a schematic perspective view of FIG. 2.

Hereinafter, the resin transfer molding method of the fiber-reinforced plastic using the upper and lower molds according to the present invention will be described with reference to the drawings.

1 is a perspective view showing an example of a product molded by a fiber-reinforced plastic resin transfer molding method using the upper and lower molds according to the present invention according to the present invention, Figure 2 is a top and bottom of the mold for forming the product of Figure 1 3 is a schematic perspective view of FIG. 2.

FIG. 1 is a view illustrating a side mirror generally used in a vehicle, and a vehicle part such as the side mirror is produced by injection molding using plastic, and the like. However, the general plastic injection molding is frequently exposed to direct sunlight and high temperature environment, the deformation of the material is concerned, the strength is also not high, and products using fiber-reinforced plastics (FRP) has recently been in the spotlight. Such fiber-reinforced plastics can be applied to various vehicle parts such as spoilers, bumpers, moldings, as well as the side mirrors, and in recent years, also used as a material for forming the exterior of small-sized vehicles such as single-seater electric vehicles. Is gradually widening.

FIG. 2 is a view showing a schematic configuration diagram of a device for a method of transport molding a fiber-reinforced plastic using upper and lower molds for forming a product using such fiber-reinforced plastic.

As shown, the fiber-reinforced plastic molding apparatus according to the present invention provides a lower mold 10, the upper mold 20 to flow the fiber-reinforced plastic resin (FRP) in the gap therebetween to mold the product.

The material of the upper and lower molds 20 and 10 may be variously configured, but in general, after the model of the product to be molded is manually worked with a material having excellent processability such as clay or gypsum, the mold may be formed using silicon or the like. It is common to form a mold and to mold a mold using this mold. However, the present invention is not limited thereto and may be configured by performing machining using an NC machine or the like as necessary.

Meanwhile, a first release layer 101 is stacked on a surface on which a product shape of the lower mold 10 is formed, and a second release layer 102 is laminated on a surface on which a product shape of the upper mold 20 is formed. Can be. The first and second release layers 101 and 102 may be laminated with a film or the like, and may be a liquid-soluble release liquid such as PVA (polyvinyl alcohol) or a semi-solid state such as wax using a spray or a brush. It is also possible to apply and form a mold release agent. The first and second release layers 101 and 102 are made of fiber-reinforced plastic filled in the space 100 formed by the combination of the upper and lower molds 20 and 10, and the upper and lower molds 20 ( It is designed to be easily separated from 10).

In addition, as shown in Figure 2, the lower mold 10 is preferably provided with a first vacuum groove (V1) and the second vacuum groove (V2) for at least two or more vacuum adsorption. At this time, the width of the first vacuum groove (V1) is preferably formed to be narrower than the width of the second vacuum groove (V2).

In addition, a first sealing member S1 may be interposed between the first vacuum groove V1 and the second vacuum groove V2, and a second sealing member may be disposed outside the second vacuum groove V2. S2) can be installed.

The first and second sealing members S1 and S2 may be formed of different materials. According to a preferred embodiment of the present invention, the first sealing member S1 may be formed of a silicon material. The second sealing member S2 is preferably formed of a foamable resin material.

The reason why the materials of the first and second sealing members S1 and S2 are made of different materials as described above is due to the difference in their roles and the material properties of the fiber-reinforced plastics used for product molding.

That is, since the raw material of the fiber-reinforced plastic material is in a swelled state before pressing, the space 100 (see FIG. 2) is maintained at a constant volume by pressing and adhering the upper and lower molds 20 and 10. It is important to do. However, when forming a vacuum groove of about one line for vacuum adsorption as in the conventional Light RTM process, it is difficult for the upper and lower molds 20 and 10 to be sufficiently in close contact, and in some cases, There is a problem that the fiber-reinforced plastic may overflow. In particular, when the first and second release layers 101 and 102 are formed of a film-like material, the upper and lower molds 20 and 10 may be formed due to the configuration of the film layers 101 and 102. In this case, it may be difficult to sufficiently maintain the degree of vacuum of the first and second vacuum grooves V1 and V2 because this may not be in close contact.

However, as described above, when the first and second vacuum grooves V1 and V2 are configured by forming the first and second sealing members S1 and S2 of different materials, the upper and lower molds ( It is possible to maintain the adhesiveness of 20) (10) without problems.

Meanwhile, the first valve 31 is connected to the first vacuum groove V1 through the first flow path 21, and the second valve 32 is connected to the second vacuum groove V2 through the second flow path 22. Can be connected. The first and second valves 31 and 32 are connected to a vacuum suction device, which is not shown, to suck air in the first and second vacuum grooves V1 and V2, and thus, the first and second valves 31 and 32. The molds 20 and 10 can be brought into close contact with each other. As shown in FIG. 3, the first valve 31 and the second valve 32 may be connected to an unshown vacuum suction device and first and second hoses 41 and 42.

Meanwhile, a space 100 is formed in the space portion formed between the upper and lower molds 20 and 10 so that the molded product 1 shown in FIG. 1 can be formed. The space 100 may be injected with fiber-reinforced plastic from the outside through the third flow path 23. A third valve 33 is installed at the inlet end of the third flow path 23, and may be connected to a fiber reinforced plastic injection device not shown and a third pipe. In addition, although not shown, an additional flow path is further formed like the third flow path 23, and connected to the fourth valve 34, as shown in FIG. 3, to be injected through the third flow path 23. The reinforced fiber reinforced plastic may be configured to be partially discharged to the fourth hose 44 connected to the fourth valve 34. At this time, the fourth hose 44 is preferably formed of a transparent or translucent material, which is to facilitate the operator to check whether the fiber-reinforced plastic is withdrawn through the fourth hose (44).

When the fourth valve 34 is connected to the vacuum suction device such as the first and second valves 31 and 32, the fourth valve 34 is opened to discharge air in the inner space of the upper and lower molds 20 and 10. It may be configured to be able to, and closed after the air is released, to maintain the vacuum state inside the space 100, the first and second vacuum groove (V1) (V2).

According to such a configuration, in the state in which the first to fourth valves 41 to 44 are all closed, the internal vacuum state of the upper and lower molds 20 and 10 can be maintained as it is, and a separate fixed unit It is possible to maintain the close contact of the upper and lower molds 20 and 10 without.

However, in the present invention, in order to ensure the stability of the mold apparatus, as shown in Figures 2 and 3, a plurality of separate fixing member 50 to the outside of the upper and lower molds 20, 10 It is preferable to maintain the close contact state of the upper and lower molds 20 and 10 through the fixing thereof.

On the other hand, although not shown, the first valve 31, the second valve 32 and the fourth valve 34 are all connected to the same vacuum suction device, which is the amount of air discharged through the same control panel This can be adjusted more easily.

The alignment unit 60 is configured such that the lower mold 10 and the upper mold 20 are always coupled at the correct position, and according to a preferred embodiment of the present invention, as shown in FIG. At least four guide protrusions 61 may protrude from the mold 10, and the upper mold 20 may be configured to recess the guide grooves 62 at positions corresponding to the guide protrusions 61.

Positions of the guide protrusion 61 and the guide groove 62 may be formed opposite to each other.

The guide protrusion 61 and the guide groove 62 may have a size corresponding to each other so as to be snap fit. When the tolerance is too small, the lower mold 10 and the upper mold 20 are completely in close contact with each other. Since it may not be possible, it is preferably formed to have a tolerance of about 0.1 to 0.5mm, so that when the external force is applied, the lower and upper molds 10 and 20 can be easily separated.

The guide protrusion 61 and the guide groove 62 may be integrally formed while forming the lower mold 10 and the upper mold 20, and each installation position is at a position close to the four corners of the mold. It is preferable to install.

In addition, the alignment unit 60 for the guide is preferably installed at a position spaced apart as far as possible from the space 100 in which the product is formed, and is configured so as not to affect the molding of the product.

On the other hand, although not shown, the alignment unit 60 is installed in any one of the lower or upper mold 10, 20, the guide projection 61 formed of a separate member, such as a metal pin, and in the corresponding position It is also possible to form a through hole that can pass through the guide protrusion 61.

When the alignment unit 60 is provided, the mold is pushed by the pressure of the fiber-reinforced plastic injected at a high pressure, and the coupling of the upper and lower molds 20 and 10 is twisted to deform the shape of the space 100. Can be prevented, and product defects can be reduced.

Although embodiments according to the present invention have been described above, these are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent ranges of the embodiments are possible. Accordingly, the true scope of the present invention should be determined by the following claims.

One; Molded product 10; Lower mold
20; Upper mold 21; The first euros
22; Second flow path 23; 3rd Euro
31; First valve 32; Second valve
33; Third valve 34; Fourth valve
41; First hose 42; 2nd hose
43; Third hose 44; 4th hose
V1; First vacuum groove V2; 2nd vacuum groove
S1; First sealing member S2; Second sealing member
50; Fixing member 60; Alignment unit
61; Guide protrusion 62; Guide groove

Claims

A lower mold having at least two vacuum grooves;
An upper mold coupled to the lower mold upper side to form a complementary shape to form the vacuum groove;
A resin injection valve for injecting resin into a space formed by engagement of the lower and upper molds; And
At least one vacuum suction valve installed to remove air in the vacuum groove and the space; And
A resin transfer molding apparatus for fiber-reinforced plastics using upper and lower molds, comprising: an alignment unit which protrudes at a position complementary to the lower and upper molds, and includes at least four paired pairs to guide coupling positions of the lower and upper molds.

The method of claim 1, wherein the alignment unit,
A guide protrusion having four of the lower molds protruding from each corner; And
And a guide groove recessed in a position corresponding to the guide protrusion of the upper mold.

The method of claim 1,
The guide projection and the guide groove is a resin transfer molding apparatus of fiber-reinforced plastic using the upper and lower molds are formed integrally to each of the lower and upper molds.