JP3666808B2 - Molding method for fiber reinforced plastic parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a hollow fiber reinforced plastic part in which the shape of an air spoiler (the rear stabilizer of an automobile) for stability during high-speed driving of an automobile is formed. In particular, the bag used for internal pressure molding is removed. The present invention relates to a method for molding fiber reinforced plastic parts.
[0002]
[Prior art]
Conventionally, when molding carbon fiber reinforced plastic (hereinafter also referred to as CFRP), etc., many have been molded by autoclave method, RTM method, and hand lay-up. A process is used. Further, in order to integrally mold the hollow molded part, a core is used as seen in injection molding of a thermoplastic resin.
[0003]
Moreover, in recent years, it has a cylindrical shape such as a tail cone member of a small helicopter, and an internal pressure forming method of an adhesion-less structure is seen, but this has a large area opening. Further, as a member having almost no opening, a steering wheel having a relatively simple cross-sectional structure is made by the same manufacturing method.
[0004]
Further, a technique such as Japanese Patent Application Laid-Open No. 5-213235 is known regarding an air spoiler for an automobile and a manufacturing method thereof. In this technology, the upper part and the lower part are molded with thermoplastic resin, the molding is fixed to the joint between the upper part and the lower part, and then the bonding ribs are bonded to the upper part and the lower part and combined. An air spoiler is formed.
[0005]
In addition, as a technology to mold a lighter air spoiler that can withstand wind pressure during high-speed running, upper and lower parts are molded by hot pressing from a sheet-like thermosetting resin containing glass fiber, There is also known a technique in which the upper and lower parts are bonded and combined by some means.
[0006]
[Problems to be solved by the invention]
However, there is a steering wheel, etc. that has a minimum of the opening of a hollow molded part that is integrally molded, and the nylon bag used for internal pressure molding when molding this steering wheel cannot be removed from the hollow molded part. It is used as it remains. However, if the bag remains in the part, the weight of the remaining bag is increased, and abnormal noise is generated from the wrinkled portion of the bag remaining in the interior, resulting in a problem in terms of merchantability.
[0007]
In such a steering wheel having a relatively simple cross section, the inner bag has a near net shape that is substantially the same as the inner shape of the product.
[0008]
For parts having a fine shape such as an air spoiler, it is difficult to produce a near-net-shaped bag itself, and there is a problem that the cost is greatly increased due to the production of the bag.
[0009]
The present invention has been made in order to solve the above-mentioned problems. In addition to solving problems (weight-up, abnormal noise) caused by remaining bags, a hollow molded part having a fine shape is integrally molded, and the minimum An object of the present invention is to provide a method for molding a fiber-reinforced plastic part in which an internal bag is removed from a limited opening.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention that has solved the above-mentioned problems is a hollow structure in which an uncured plastic layer is laminated on a hollow inner surface of a mold having a hollow inner surface , and is formed and cured in a heating furnace. In the method for molding a fiber reinforced plastic part, a step of laminating an uncured plastic layer having the inner surface shape formed on an inner surface of the mold, and a step of providing a bag along the surface of the uncured plastic layer in the mold And carrying out hollow molding by filling the bag with air, and the bag includes a wire having one end attached to the tip of the bag and the other end drawn out through the bag. And pulling the other end of the wire drawn out after the hollow molding, thereby removing the bag from the fiber reinforced plastic part while peeling from the tip portion. It is characterized in.
[0011]
According to the first aspect of the present invention, since the molded bag can be pulled out, it is possible to eliminate the generation of noise caused by the bag as well as the weight of the remaining bag. . Moreover, in the air spoiler, since the inside is completely hollow, it is possible to use a hollow portion as a harness passage when installing a high-mount stop lamp or the like. Furthermore, by removing the bag, the parts can be made into a single material, improving recyclability.
[0012]
According to a second aspect of the present invention, in the first aspect of the invention, the attachment of one end of the wire to the front end of the bag is performed by folding the front end of the bag inward, and the front end of the bag is connected to the wire. It is characterized by being tied at one end.
[0013]
According to the invention of claim 2, by pulling the bag from the end of the wire attached to the bag when the bag is removed, the wire attached to the tip of the bag is folded and tied inside. The bag can be prevented from being torn.
[0014]
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the mold has left and right openings, and the bag is abutted in the middle of the mold and arranged symmetrically. The wire is pulled out from the left and right openings.
[0015]
According to the third aspect of the present invention, it is possible to eliminate the variation in the way of swelling that occurs when the inside of the bag is pressurized during the internal pressure molding process, and to obtain a symmetrical shape.
[0016]
Invention according to claim 4, configured in the invention described in any one of claims 1 to 3, wherein the bag is inside is composed of nylon, the outer contacting the fiber-reinforced plastic components from polypropylene It is characterized by being.
[0017]
According to the invention described in claim 4, in addition to the effect of the invention described in any one of claims 1 to 3, a nylon bag having high strength is used to prevent tearing when the bag is taken out. Since a two-layer structure is used using a bag covered with a PP film, the peelability can be improved and the bag after molding can be removed more easily.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment
An embodiment of a method for molding a fiber-reinforced plastic part according to the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a method for molding a fiber-reinforced plastic part according to the present invention, FIG. 1 (a) is a cross-sectional view showing the fiber-reinforced plastic part being heated in a furnace, and FIG. 1 (b) is FIG. It is the A section enlarged view in a). 1 (a) and 1 (b), an air spoiler 20, which is a hollow fiber reinforced plastic part, has a prepreg 11 formed by impregnating carbon fiber with an epoxy resin on the inner surface of a mold 10 for molding the air spoiler 20. After the lamination, the bag 12 covered with the PP film 14 is provided in the mold 10 along the surface of the prepreg 11 having the inner surface shape, and is located on the side opposite to the pressurizing hole 13 of the bag 12. The front end of the bag 12 is folded inward, and the wire 15 is fixed to the folded portion. The bag 12 is filled with air, internal pressure is applied from the inside, and the bag 12 is pressed against the mold 10 to transfer the shape. At this time, the heating furnace 1 is heated at a temperature of 120 to 130 ° C. for about 2 hours, and the hollow molding is completed. Then, after allowing to cool in the heating furnace 1 for about 4 hours, the bag 12 can be taken out and removed by pulling the wire 15 outward from the pressure hole 13 of the mold 10. The air is pressurized air generated by the compressor 3 and is guided to the mold 10 by the pipe 2.
[0019]
Here, the prepreg will be described. The prepreg is an intermediate molding material, which is made by knitting fibers into a sheet shape, impregnating a resin to make a semi-cured state, and is not completely cured.
[0020]
At the time of molding, a prepreg or SMC is placed on the surface of the mold 10, and then the bag is inflated by applying internal pressure and pressed against the mold 10. Heat in that state, mold and cure with epoxy resin.
[0021]
Since these epoxy resins and prepregs are fluidized by heating, there is little pressure loss and pressure is easily transmitted. When the shape is complete, it is heated in the heating furnace 1 while leaving the bag. The temperature in the heating furnace 1 is 120 to 130 ° C., and the bag 12 does not change quality when heated because it uses nylon. Nylon has a heat-resistant temperature of about 200 ° C., and nylon does not deteriorate at the temperature when the epoxy resin is baked and hardened.
[0022]
Incidentally, when molding is performed using a molding method in which internal pressure is applied by air, whether or not molding is possible is determined by the followability of the bag 12 inserted into the molding die 10. In addition, the hollow integrated molding can eliminate the joints and can improve the design of the design. In addition, since the air spoiler 20 requires a desired shape in order to obtain aerodynamic characteristics, a fine shape molding technique is important.
[0023]
At this time, it is preferable to form the bag 12 in a near net shape which is molded with high accuracy in advance. However, in order to form the bag 12 with high accuracy in advance, the cost for parts is increased at the same time. For this reason, the use of a relatively simple bag-shaped bag results in a follow-up problem.
[0024]
As described above, when a near-net-shaped bag is used to avoid an increase in cost and a bag-like bag is used, a portion where the bag does not follow, such as an extremely acute-angled portion, is generated. For this reason, when using an inexpensive bag-shaped bag, it is necessary to provide the bag with sufficient slack as shown in FIG. 1 (b) and place it in the mold. It is expected that the contained epoxy resin will enter and hold the bag, making it difficult to remove the bag 12. That is, when the resin holds the bag, the bag 12 is often torn and cannot be removed simply by pulling from the end.
[0025]
For this reason, the nylon bag 12 covered with the PP film 14 having good releasability is disposed in contact with the surface of the material with sufficient slack so that the epoxy resin can be held when the bag 12 is removed. Can be prevented. However, the bag 12 may be broken only by pulling and pulling the bag 12 from the end.
[0026]
Therefore, as shown in FIG. 1 (b), the PP (polypropylene) film and nylon bag tip are folded back inward, the inside is tied with a wire, and the wire is sufficient so that the bag is not restrained during molding. The bag is passed through the bag in a slack shape and pulled out from the pressure hole 13. Since the bag 12 is inflated when the inside is pressurized and varies in how it swells, in order to obtain a symmetrical shape, the bag 12 is arranged on the left and right so that air can be filled from the left and right directions. . And it can be made bilaterally symmetrical by butting in the middle of the shaping | molding die 10. FIG.
[0027]
After the molding is completed, the bags 12 and 12 can be easily removed by pulling the bags 12 and 12 from the pressure holes 13 and 13 that are openings. Even if the PP film is partially broken, there is no problem unless the nylon bag is broken.
[0028]
FIG. 2 is an enlarged view of part A from which the bag in FIG. 1A is removed. As shown in FIG. 2, since the bag 12 is covered with a PP film having good releasability, it is peeled off from the interface of the prepreg 11. Therefore, the noise generated from the air spoiler 20 can be eliminated together with the weight reduction of the air spoiler 20.
[0029]
FIG. 3: shows the outline of the air spoiler made with the fiber reinforced plastic component which concerns on this invention, (a) is a perspective view which shows the outline of the whole air spoiler, (b) is BB sectional drawing in (a). is there. The air spoiler 20 for automobiles shown in FIG. 3A has a hollow portion 21 as shown in FIG. The hollow portion 21 has an opening (not shown) communicating with the outside, and a high mount lamp (not shown) is embedded in the opening, and a hole or the like for passing a wiring connected to the high mount lamp is provided. It has been.
[0030]
According to the present invention, the bag remains inside the air spoiler and hinders weight reduction, and noise generated from the remaining bag can be eliminated. Further, it is possible to prevent an increase in cost due to the production of a near net-shaped bag.
[0031]
The embodiment described above is an example for explaining the present invention, and the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the invention. For example, in this embodiment, as a means for improving the releasability, not only the PP film but also a nylon bag may be coated with Teflon (R), and other materials may be used as long as they have no affinity. I do not care. Further, the wire providing the removal method may be any material such as metal or resin as long as it can withstand the molding temperature. Further, although the pressure applied to the bag is pressurized air, it is sufficient that the pressure does not cause the bag to swell and break. In addition to pressurized air, a high-pressure liquid may be used.
[0032]
【The invention's effect】
According to the first aspect of the present invention, the front end of the bag is folded inward so that the inside of the bag can be passed through and pulled out from the pressure hole. As a result, it is possible not only to reduce the weight of the remaining bag, but also to eliminate abnormal noise caused by the bag. Further, since the interior is completely hollow, it is possible to use the hollow portion as a harness line when installing a high-mount stop lamp or the like. Furthermore, by removing the bag, the parts can be made into a single material, improving recyclability.
[0033]
According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the wire attached to the front end of the bag is folded back and tied, so that the end of the bag can be removed when the bag is removed. The bag can be prevented from being torn by pulling.
[0034]
According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, it eliminates the variation in the swelling method that occurs when the inside of the bag is pressurized during the process of internal pressure molding. Thus, a symmetrical shape can be obtained.
[0035]
According to the invention described in claim 4, in addition to the effect of the invention described in any one of claims 1 to 3, the bag made of high strength nylon is used to prevent tearing when the bag is taken out. Since the bag is covered with a PP film to form a two-layer structure, the peelability can be improved and the bag after molding can be removed more easily.
[0036]
As described above, the fiber-reinforced plastic molding method of the present invention is manufactured without heat treatment of a semi-cured fiber-reinforced plastic member to produce an integrally molded product, and thus is obtained without requiring an adhesive, bolts, rivets, etc. Molded articles have high reliability with respect to mechanical strength.
[Brief description of the drawings]
FIG. 1 shows an outline of a method for molding a fiber-reinforced plastic part according to an embodiment of the present invention, (a) is a cross-sectional view showing a fiber-reinforced plastic part being heated in a furnace, and (b) is (a). FIG.
FIG. 2 is an enlarged view of part A showing a state in which the bag in FIG. 1 (a) has been removed.
FIG. 3 shows an outline of an air spoiler made of fiber-reinforced plastic parts according to an embodiment of the present invention, and (a) is a perspective view showing an outline of the entire air spoiler. (B) is BB sectional drawing in (a).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Pressurized air piping 3 Compressor 10 Mold 11 Prepreg 12 Bag 13 Pressurization hole 14 PP film 15 Wire 20 Air spoiler 21 Hollow part

Claims (4)

In a molding method of a hollow fiber reinforced plastic part having a hollow inner surface and laminating and curing an uncured plastic layer on the inner surface of the mold,
Laminating the uncured plastic layer on the inner surface of the mold to form an inner surface shape ;
Providing a bag along the surface of the uncured plastic layer in which the inner surface shape is formed in the mold;
Filling the bag with air and performing hollow molding;
Including
The bag includes a wire having one end attached to the tip of the bag and the other end drawn outside through the bag,
A method for molding a fiber reinforced plastic part , wherein after pulling out the other end of the wire drawn out after the hollow molding, the bag is taken out from the fiber reinforced plastic part while being peeled off from the tip part . The attachment of the one end of the wire to the tip of the bag is made by folding the tip of the bag inward and binding the tip of the bag with one end of the wire. Molding method for fiber reinforced plastic parts. The mold has openings on the left and right sides,
3. The method for molding a fiber-reinforced plastic part according to claim 1, wherein the bag is abutted in the middle of the mold and arranged symmetrically, and the wire is pulled out from the left and right openings. The bag inside is composed of nylon, fiber-reinforced plastic component according to any one of claims 1 to 3, the outer contacting the fiber-reinforced plastic part is characterized by being composed of polypropylene Molding method.

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