JP2004330501A - Foamed core material, frp molded product using it, method for manufacturing the foamed core material and method for manufacturing the frp molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed core material excellent in strength as a three-dimensional foamed core material used as the core material of an FRP molded product. <P>SOLUTION: The foamed core material 2 is used in the FRP molded product obtained by coating the periphery of the three-dimensional foamed core material comprising a foamble resin with a fiber reinforced resin layer using a thermosetting resin as a matrix resin. Pillar-like members 4 comprising a non-foamable thermosetting resin are arranged so as to pierce a core material body 3 and almost lattice-like reinforcing members 5 comprising the same non-foamable thermosetting resin are arranged on the surface of the core material body 3 to reinforce the core material body 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a foamed core material, an FRP (Fiber Reinforced Plastics) molded product using the same, and a method for producing the same, and in particular, a foamed core material having sufficient strength when used as a core material of an FRP molded product, and a core material thereof The present invention relates to an FRP molded product using the same as a core material, a foamed core material thereof and a method for producing the FRP molded product.
[0002]
[Prior art]
When manufacturing a hollow three-dimensional FRP molded product, in addition to the construction method using a so-called balloon-shaped hollow bag as a core material, a half-split preform is molded as a so-called middle structure After that, a method of adhesively bonding the preforms to each other is often used.
[0003]
However, in the former method, it is difficult to position and maintain the shape of ribs when it is desired to set partition ribs inside to increase the rigidity and strength of the structure.In the latter method, the bonding process is difficult. The third method is to increase the density of the hollow part by increasing the time required for the production, as well as greatly reducing the productivity for securing the alignment accuracy between the preforms. As a small foam, a method of covering the periphery with a fiber reinforced resin has been attempted, for example, in Patent Documents 1 and 2.
[0004]
According to this method, by using the foam as the core material (core material), for example, the core material is divided at a portion corresponding to the rib, and the reinforcing fiber is sandwiched between the divided core materials, thereby improving the accuracy. A good rib can be integrally formed, and a product having a good outer surface can be obtained by putting the intermediate molded body into a molding die and molding.
[0005]
[Patent Document 1]
JP-A-11-254566 (FIG. 2)
[0006]
[Patent Document 2]
JP-A-2000-233364 (page 3 and FIG. 4)
[0007]
[Problems to be solved by the invention]
However, foams have bubbles as a whole because of their specialty, so when subjected to an external load, the surface is easily dented or depressed.In particular, the density of the foam is reduced to form a lighter product. The smaller the size is, the more remarkable the above tendency becomes.
[0008]
Therefore, when the foam is covered with the reinforcing fiber or when the foam covered with the reinforcing fiber is set in the mold, if the foam is depressed or depressed, the amount of the resin to be impregnated increases and the product is impregnated. In addition to locally increasing the thickness of the sheet or lowering the strength, the reinforcing fiber becomes too soft to cause wrinkles on the surface of the product.
[0009]
It is also possible to use a foam that is hard against external loads and does not easily cause depressions or depressions on the surface, but that type of foam is very expensive, and it is particularly desirable to manufacture a cheap and lightweight product. Cannot be adopted in the case.
[0010]
The present invention has been made in view of such a problem, and is premised on a foam core material used as a core material of an FRP molded product. An object of the present invention is to provide an FRP molded article using the foamed core material and a method for producing the same, in addition to providing a small structure.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 is a three-dimensional foam core material used as a core material of an FRP molded product, wherein a columnar member made of a non-foamable thermosetting resin penetrates the core material body. And a reinforcing member made of a non-foaming thermosetting resin, and the surface of the core material body is reinforced in a substantially lattice-like manner, and desirably, as described in claim 2. It is assumed that the columnar member and the reinforcing member are connected to each other and are integrally formed with the core material main body.
[0012]
According to a third aspect of the present invention, as a method of manufacturing the foamed core material according to the first aspect, a through-hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member are formed in a preformed core material body. And a step of molding the columnar member and the reinforcing member integrally with the core material body by placing the core material body in a mold and filling with a non-foamable thermosetting resin material. And
[0013]
In this case, instead of forming the through-hole corresponding to the columnar member and the concave portion corresponding to the reinforcing member in the preformed core material main body, a foamable resin material is provided in the molding die. To form a core material main body having a through hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member.
[0014]
According to a fifth aspect of the present invention, there is provided an FRP molded product in which the foamed core material according to the first aspect is covered with a fiber reinforced resin layer using a thermosetting resin as a matrix resin.
[0015]
Further, according to a sixth aspect of the present invention, as a method of manufacturing the FRP molded product according to the fifth aspect, a through hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member are formed in a preformed core material main body. Forming a columnar member and a reinforcing member integrally with the core material body by placing the core material body in a molding die and filling a non-foaming thermosetting resin material; and Covering the core material main body on which the member is molded with a fiber-reinforced resin layer using a thermosetting resin as a matrix resin.
[0016]
In this case, instead of the step of processing the through-hole corresponding to the columnar member and the concave portion corresponding to the reinforcing member in the preformed core material main body, a foamable resin material is provided in the molding die. To form a core material main body having a through hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member.
[0017]
Therefore, in the first and third aspects of the present invention, the foamed core material itself, which is to be the core of the FRP molded product, is reinforced by the columnar member or the surface reinforcing member of the thermosetting resin. Even when pressure is applied to the foamed core material during molding, the foamed core material is less likely to be deformed, and as a result, wrinkles and variations in the thickness of the fiber reinforced resin layer are reduced.
[0018]
According to the fifth and sixth aspects of the present invention, a columnar member or a reinforcing member made of a thermosetting resin is formed integrally with a soft foam core material by a simple method. Even when pressure is applied to the foamed core material during molding, the foamed core material is less likely to be deformed, and as a result, wrinkles and variations in the thickness of the fiber reinforced resin layer can be reduced.
[0019]
【The invention's effect】
According to the first, third and fifth and sixth aspects of the present invention, since the foamed core material itself is reinforced by the columnar member made of the thermosetting resin or the reinforcing member on the surface, it is possible to form the FRP molded product. In this case, even when an external force is applied, the foamed core material is not easily deformed, the thickness accuracy of the fiber reinforced resin layer is improved, wrinkles of the reinforcing fibers can be prevented, and the surface quality of the FRP molded article is also improved. In addition, the use of an inexpensive and lightweight foam core material suffices due to the above-described quality improvement, so that there is an effect that a lightweight FRP molded product with a small increase in cost can be formed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 4 show a first preferred embodiment of the present invention. In particular, FIG. 2 shows a closed cross-sectional structure used as a substitute for a hollow FRP molded product while focusing on weight reduction as described above. FIG. 1 shows an example of a (solid structure) FRP molded product 1, and a foam core material 2 used as a core material of the FRP molded product 1.
[0021]
The FRP molded article 1 illustrated in FIG. 2 has a cubic or rectangular parallelepiped shape, and the substantially similar foamed core material 2 shown in FIG. It is covered with a fiber reinforced resin layer 1a using a curable resin as a matrix resin.
[0022]
As shown in FIG. 1 (C), the foamed core material 2 has a core material body 3 made of a foamable resin as a base, a columnar member 4 described below, and a surface layer portion having a substantially lattice-like reinforcing member. 5, and is characterized in that the strength of the foam core material 2 as a whole against external pressure is dramatically increased as compared with the conventional one. More specifically, as shown in FIG. 1A, a cubic or rectangular parallelepiped core material body 3 is preformed with a predetermined foamable resin material, and the core material body 3 is individually penetrated through the entire six surfaces of the core material body 3. The plurality of through holes 6 are processed so as to cross each other. Further, a recess 7 is formed on the entire outer peripheral surface of the six surfaces of the core material body 3 at a portion where the lattice-like reinforcing member 5 is to be disposed, as shown in FIGS. After the core material main body 3 on which the secondary processing of the through-holes 6 and the recesses 7 has been performed is put into a predetermined mold, the non-foaming thermosetting is placed at a position corresponding to the through-holes 6 and the recesses 7. The columnar member 4 and the reinforcing member 5 are integrally formed by filling a conductive resin material. As a result, the columnar members 4 are connected to each other at the intersection of the center of the core material main body 3, and the reinforcing members 5, 5 are also connected to the columnar members 4 while being connected to each other. The foamed core material 2 shown in FIG. 1C reinforced with the columnar members 4 and the reinforcing members 5 is formed flush with the material main body 3.
[0023]
FIG. 4 shows a more specific method of forming the foamed core material 2 using the core material main body 3 on which the secondary processing of the above-described through holes 6 and concave portions 7 and the like has been performed.
[0024]
As shown in FIG. 3A, the core material body 2 previously processed is inserted into the product shape space 11 of the lower die 8 of the molding die 10 composed of the lower die 8 and the upper die 9, and Is filled with a non-foamable thermosetting resin material so as to sufficiently fill the through holes 6 and the concave portions 7. Then, the upper mold 9 is closed and the thermosetting resin material is cured. If the mold is opened after a predetermined time has passed and the mold is released, the foamed core material 2 reinforced by the columnar members 4 and the lattice-like reinforcing members 5 is formed as shown in FIG.
[0025]
When the foam core material 2 is formed in this manner, the periphery thereof is covered with, for example, a sheet-like reinforcing fiber. Even if the foamed core material 2 is covered with the reinforcing fibers, the foamed core material 2 itself is reinforced in advance by the columnar members 6 and the reinforcing members 7 made of a thermosetting resin, so that it is lightweight but has sufficient pressure resistance. And does not dent or collapse due to deformation as in the prior art.
[0026]
Next, the foamed core material 2 covered with the reinforcing fibers is placed in a molding die (not shown) and sealed, and a thermosetting resin material as a matrix resin is injected and filled into the mold, and the resin material is converted into reinforcing fibers. Cure while impregnating. Then, if the mold is removed after a predetermined time has elapsed, the above-described FRP as shown in FIG. The molded article 1 is obtained.
[0027]
In this case, when the foamed core material 2 covered with the reinforcing fibers is set in a molding die, even if there is a gap between the reinforcing fibers and, for example, a partially sparse and dense state occurs, the foamed core material 2 Since itself is sufficiently reinforced by the columnar members 6 and the reinforcing members 7 as described above, the reinforcing fibers are not dented or depressed by the influence of the density of the reinforcing fibers as described above. It plays a role of pushing the mold surface of the mold in such a way that it is actively extended. As a result, the FRP molded product 1 having a small variation in the thickness of the fiber reinforced resin layer 1a and a good surface accuracy is molded.
[0028]
Here, instead of setting the foamed core material 2 covered with the reinforcing fiber in the mold, the reinforcing fiber is set in the mold in advance, and then the foamed core material 2 alone is placed in the mold. You may make it set.
[0029]
5 and 6 show a second embodiment of the present invention, and show another example of a molding procedure of the foamed core material 2.
[0030]
That is, in the first embodiment, the preformed core material main body 3 is subjected to the secondary processing of the through holes 6 and the concave portions 7 at positions where the columnar members 4 and the reinforcing members 5 are to be formed. On the other hand, in the second embodiment, as shown in FIG. 6, the core material body 23 itself is formed and the through holes 16 and the recesses 17 equivalent to the through holes 6 and the recesses 7 are formed at a stroke in the second embodiment. It is to be molded.
[0031]
As shown in FIG. 5, a molding die 12 for molding a core material main body 23 is composed of a lower die 13 and an upper die 14. The lower die 13 has a prismatic shape which can be moved forward and backward by driving a cylinder 15. The plurality of core pins 18, 19 are provided so as to face the product shape part space 20. These core pins 18 and 19 are for forming the through-hole 6 to be the columnar portion 4 as described above when the rectangular or cubic core material body 23 is formed from the foamable resin material. If one core pin 18 serving as the center is disposed so as to penetrate the product shape space 20, the other core pins 19, 19 abut against the center core pin 18 so as to intersect each other. It has been set. In addition, it is desirable that a buffer material is appropriately provided in a portion where the core pins 18 and 19 are in direct contact with each other to suppress direct interference between the core pins 18 and 19.
[0032]
Also, in the inner surfaces of the upper and lower dies 13 and 14 which are to be the product shape space 20 of the molding die 12, concave portions 7 and 7 which are to be the reinforcing members 5 are formed in the same manner as in FIGS. A convex portion 21 having a shape inverted from the concave shape is formed.
[0033]
Therefore, the foamed resin material is filled in the product shape space 20 in a mold-clamped state as shown in FIG. 5C and with the core pins 18 and 19 protruding, and the core material body 23 is formed. At this time, since a plurality of core pins 18 and 19 are arranged in the core material body 23 to be formed, the square through hole 16 is formed in the same form as that of FIG. By transferring the protrusions 21 formed on the upper and lower dies 13 and 14, the recesses 17 to be the reinforcing members 5 are formed on the surface of the core material main body 23 as in FIGS. 1B and 3. . Note that the through holes 16 do not necessarily have to be square. Then, when the mold is opened as shown in FIG. 5A, the core pins 18 and 19 are moved backward and then removed from the mold, whereby the core material body 23 as shown in FIG. 6 can be obtained.
[0034]
Thereafter, the core member main body 23 is inserted into the molding die 10 similar to that of FIG. 4, and the columnar member 4 and the reinforcing member 5 are integrally molded using a non-foaming thermosetting resin material, respectively. A foam core material 2 similar to that shown in FIG. 1C can be obtained.
[0035]
According to this embodiment, since the through hole 16 and the concave portion 17 are formed simultaneously with the molding of the core material body 23, the through hole 6 and the concave portion 7 are formed after the core material body 3 is formed as shown in FIG. Need not be subjected to secondary processing, and the number of processing steps can be reduced.
[Brief description of the drawings]
1A and 1B are diagrams showing a first preferred embodiment of the present invention, wherein FIG. 1A is a schematic explanatory view of a core material main body to be a foamed core material, and FIG. (C) is a schematic explanatory view of a foamed core material formed with the core material body of FIGS. (A) and (B).
2A is a schematic explanatory view showing an example of an FRP molded product using the foamed core material shown in FIG. 1 as a core material, and FIG. 2B is a cross-sectional view taken along the line aa in FIG. .
FIG. 3 is an enlarged sectional view taken along line bb of FIG. 1 (B).
4A is an explanatory view of a configuration of a molding die for molding the foamed core material shown in FIG. 1C, and FIG. 4B is an explanatory plan view of a lower mold of FIG. 1A.
FIG. 5 is a view showing a second embodiment of the present invention, and is a configuration explanatory view of a mold for molding a core material main body in a single-open state, and FIG. 5B is a lower mold of FIG. (C) is an explanatory view of the configuration in the mold-clamped state of FIG. (A).
FIG. 6 is a structural explanatory view of a core material main body formed by using the forming die of FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... FRP molded article 1a ... Fiber reinforced resin layer 2 ... Foam core material 3 ... Core material main body 4 ... Columnar part 5 ... Reinforcement member 6 ... Through hole 7 ... Depression 10 ... Mold 12 ... Mold 16 ... Through hole 17 ... Recess 23: Core material body

Claims (7)

A three-dimensional foam core material used as a core material of an FRP molded product,
While the columnar member made of a non-foamable thermosetting resin is arranged to penetrate the core material main body,
A foamed core material, wherein a surface of the core material body is reinforced in a substantially lattice shape by a reinforcing member also made of a non-foamable thermosetting resin. The foamed core material according to claim 1, wherein the columnar member and the reinforcing member are connected to each other and are integrally formed with the core material main body. A method for producing a foamed core material according to claim 1,
A step of processing a preformed core material body with a through hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member,
A step of forming the columnar member and the reinforcing member integrally with the core material body by placing the core material body in a molding die and filling the foaming thermosetting resin material,
A method for producing a foamed core material, comprising: Instead of processing the through-hole corresponding to the columnar member and the concave portion corresponding to the reinforcing member in the preformed core material main body,
A step of forming a core material body having a through-hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member by filling a foaming resin material in a molding die. 4. The method for producing a foamed core material according to item 3. An FRP molded product, wherein the foamed core material according to claim 1 is coated with a fiber-reinforced resin layer containing a thermosetting resin as a matrix resin. A method for producing an FRP molded article according to claim 5,
A step of processing a preformed core material body with a through hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member,
A step of forming the columnar member and the reinforcing member integrally with the core material body by placing the core material body in a molding die and filling the foaming thermosetting resin material,
A step of coating the core material body formed with the columnar member and the reinforcing member with a fiber-reinforced resin layer using a thermosetting resin as a matrix resin,
A method for producing an FRP molded product, comprising: Instead of processing the through-hole corresponding to the columnar member and the concave portion corresponding to the reinforcing member in the preformed core material main body,
A step of forming a core material body having a through-hole corresponding to a columnar member and a concave portion corresponding to a reinforcing member by filling a foaming resin material in a molding die. 7. The method for producing an FRP molded product according to item 6.

Images