JP2006181751A - Hollow rectangular parallelepiped made of frp whose one surface is opened and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an accurate and lightweight hollow rectangular parallelepiped made of FRP, whose one surface is opened, causing no liquid leak or the like by an autoclave molding method or the like using a prepreg, and to provide a manufacturing method thereof. <P>SOLUTION: In the hollow rectangular parallelepiped made of FRP, whose one surface is opened, characterized in that the prepreg is used in the mutually opposed surface and back thereof and small pieces of the prepreg cut into a short strip-like shape in the thickness direction of the rectangular parallelepiped are laminated in a desired thickness to be arranged to left and right sides and base of the rectangular parallelepiped, a fiber reinforced resin sheet is arranged at least to one sides of the laminated end surfaces of the small pieces of the prepreg so as to cover the laminated end surfaces at the time of molding. This rectangular parallelepiped is obtained by monolithic molding or by molding two members set to a mutually surface-symmetric relation and subsequently bonding the molded members by an adhesive or bolt clamping. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a hollow rectangular parallelepiped made of FRP, which is used as an FRP molded product or a part thereof, and one side of which is open, and a method for producing the same.

Fiber reinforced plastic (FRP) is a thermosetting resin such as unsaturated polyester resin, epoxy resin and polyimide resin, matrix resin of thermoplastic resin such as polyethylene, polypropylene, polyamide, PPS, PEEK, carbon fiber, glass fiber Since it is composed of reinforcing fibers such as aramid fiber and is lightweight and excellent in strength properties, it has been used in a wide range of fields from the aerospace field, transportation / transport field to general industrial field in recent years.

When molding an FRP product, a prepreg, which is a sheet-shaped molding intermediate in which a fiber reinforcing material is impregnated with a resin and is easy to handle except for fluidity and adhesiveness, is often used. And as a method for shape | molding a hollow member using a prepreg, the autoclave shaping | molding method, the hot press shaping | molding method, the vacuum bag shaping | molding method etc. are known (for example, refer patent document 1).
JP 2003-334836 A

However, when trying to obtain an FRP molded product having a complicated shape, there are cases in which a conventional method cannot always obtain a sufficient performance. For example, when trying to manufacture a hollow rectangular parallelepiped that is open on one side so as to become a container for liquid, conventionally, a prepreg having a size covering the entire surface is used on the opposite surface and back surface of the rectangular parallelepiped. First, a prepreg laminate is formed by laminating small pieces of prepreg cut into strips in the thickness direction of the rectangular parallelepiped on the left and right surfaces and the bottom surface, and then integrally molding the prepreg laminate. The method is taken. Alternatively, when integral molding is difficult, the parts forming the hollow rectangular parallelepiped are divided into two members whose horizontal cross-sections are concave with respect to each other to form two prepreg laminates, which are then molded, The members are combined in a face-to-face comparison, and the laminated portions of the laminated prepreg pieces are joined with an adhesive or a bolt to produce a hollow rectangular parallelepiped. In these cases, when a liquid is put into the hollow portion, there is a problem that liquid leakage occurs from the laminated portion of the small pieces of the prepreg depending on the type of the liquid and the operating conditions of the container.

Although not intended to solve the above-mentioned problems, when obtaining an FRP molded product by an autoclave molding method, a technique that is considered to be effective for preventing liquid leakage of the molded product is also known. For example, when a molded product having corners is molded using a prepreg, a molding method using a molding pad provided with corners having elasticity has been proposed (see Patent Document 2). Also known is a laminated member in which an inorganic foam or an inorganic mat is arranged on one side of a prepreg in order to obtain an FRP molded product excellent in fire resistance and heat insulation by an autoclave molding method using a prepreg (patent) Reference 3). However, these methods cannot completely solve the problems of the present invention.
Japanese Patent Laid-Open No. 9-226011 JP-A-11-320735

An object of the present invention is to obtain a dense and lightweight FRP molded product free from liquid leakage, etc., in particular, an FRP hollow rectangular parallelepiped having an opening on one side by an autoclave molding method using a prepreg, and the like It is to provide a method.

The present inventor has intensively studied in order to obtain a dense and lightweight FRP molded product free from liquid leakage and the like, in particular, an FRP hollow rectangular parallelepiped having an opening on one side. According to the result of the examination, in the case of the normal hot press molding method, high pressure can be applied only in one direction, but high pressure cannot be applied to the L-shaped vertical member. It was unsuitable for obtaining a dense molded product having no liquid oozing out. And since the normal autoclave molding method can press in all directions, it is suitable for molding a complex shape such as a hollow rectangular parallelepiped, but high pressurization is difficult. Therefore, it was difficult to prevent liquid leakage. The present invention has been obtained as a result of further studies.

That is, the present invention is a hollow rectangular parallelepiped made of FRP having an opening on one side, and prepregs are used on the front and back surfaces of the rectangular parallelepiped, and the thickness of the rectangular parallelepiped on the left and right sides and the bottom of the rectangular parallelepiped In a hollow rectangular parallelepiped made of FRP in which small pieces of prepreg cut into strips are arranged in a desired direction, a fiber reinforced resin sheet is disposed on at least one side of the laminated end surface of the small pieces of prepreg. A hollow rectangular parallelepiped made of FRP having an opening on one side, which is formed so as to cover the end face of the laminate.

Further, another aspect of the present invention is a method for producing such a hollow rectangular parallelepiped, that is, a hollow rectangular parallelepiped made of FRP having an opening on one side, and prepregs are used on the front and back surfaces of the rectangular parallelepiped, In the manufacturing method of the hollow rectangular parallelepiped made of FRP in which small pieces of prepreg cut in a strip shape are stacked in a desired thickness on the left and right surfaces and bottom surface of the rectangular parallelepiped, A method of manufacturing a hollow rectangular parallelepiped made of FRP having one open surface, wherein a fiber reinforced resin sheet is disposed on at least one side of the laminated end face of the small pieces of the prepreg so as to cover the laminated end face, and then integrally molded It is.

Still another aspect of the present invention is a hollow rectangular parallelepiped made of FRP having an opening on one side, and prepregs are used on the front and back surfaces of the rectangular parallelepiped. In the manufacturing method of a hollow rectangular parallelepiped made of FRP in which small pieces of prepreg cut into strips are arranged in a desired thickness in the thickness direction, two horizontal cross-sections that are opposite to each other are concave. A member obtained by arranging and molding a fiber reinforced resin sheet so as to cover the laminated end face on at least one side of the laminated surface of the small pieces of the laminated prepreg is combined with each other in a plane contrast, and the laminated This is a method for producing a hollow rectangular parallelepiped made of FRP having one open surface, in which a laminated portion of small pieces of prepreg pieces is joined to form a hollow rectangular parallelepiped.

According to the present invention, a hollow rectangular parallelepiped made of FRP having an open surface with no liquid leakage or the like, which is an FRP molded product for various uses or a member thereof, can be obtained by a simpler method than a conventional method. It is lighter and can be manufactured at a lower cost.

A hollow rectangular parallelepiped made of FRP with one surface opened in the present invention is as shown in FIG. FIG. 2 shows one of the members divided by the cutting plane AB of FIG. In FIG. 1, 1 and 2 are the front surface and back surface which oppose, and a prepreg is used here. As the prepreg used for the front surface and the back surface, one having a size that covers the entire surface with one sheet is preferable. Usually, a plurality of such prepregs are used by being laminated. In FIG. 1, 3 and 4 are the left and right surfaces of the rectangular parallelepiped, and in FIG. 2, 5 is the bottom surface. The left and right surfaces 3 and 4 and the bottom surface 5 are formed by strips of prepreg (3a, 3b,..., 4a, 4b,... In the thickness direction of the rectangular parallelepiped (perpendicular to the front and back surfaces).・ 5a, 5b,... Are stacked in a desired thickness.

As the prepreg of the present invention, a fiber reinforced material such as glass fiber, carbon fiber, or aramid fiber for reinforcement, impregnated with a matrix resin such as a thermosetting resin or a thermoplastic resin into a sheet-like material such as a nonwoven fabric. The obtained prepreg is mentioned. Although there is no restriction | limiting in particular regarding a fiber reinforcement and matrix resin, As a fiber reinforcement, a carbon fiber is preferable and the textile fabric is preferable. Examples of the woven fabric include, for example, a plain woven fabric, a twill woven fabric, a satin weaving fabric, and the like, a uniaxial woven fabric in which fiber bundles are aligned in one direction and stitched in a perpendicular direction with stitch yarn, Examples thereof include a multi-axis woven fabric in which a plurality of sheet-like materials aligned in the direction are stacked at different angles and stitched with a stitch thread in a perpendicular direction.

In the prepreg used in the FRP molded article, the ratio of the fiber reinforcement and the matrix resin is usually 30 to 70% by weight of the whole fiber reinforcement, but in the present invention, at least the laminated end face of the small pieces of the prepreg is used. Since the fiber reinforced resin sheet is disposed on one side so as to cover the laminated end surface, and this has an action of preventing liquid leakage and the like, the content of the fiber reinforced material can be reduced as compared with a normal one. Therefore, the obtained molded product is reduced in weight.

In this invention, in FIG. 1 and FIG. 2, 6, 7, and 8 are fiber reinforced resin sheets. The fiber reinforced resin sheets 6, 7, and 8 are disposed so as to cover the laminated end surfaces on at least one side of the laminated end surfaces of the prepreg pieces on the left and right surfaces and the bottom surface, respectively. 1 and 2 show examples in which the fiber reinforced resin sheets 6, 7, and 8 are arranged on the laminated end faces of the small pieces of the prepreg inside the rectangular parallelepiped, the fiber reinforced resin sheets are on the outside or on both sides. It may be arranged.

The fiber reinforced resin sheet of the present invention means a prepreg obtained by impregnating a sheet-like material such as a woven fabric or nonwoven fabric of glass fiber, carbon fiber, aramid fiber or the like with a thermosetting resin or a thermoplastic resin. . Preferred is a glass fiber prepreg. The fiber-reinforced resin sheet is used by cutting into a size that covers the left and right surfaces and the bottom surface according to the shape of the rectangular parallelepiped. The basis weight of the fiber reinforced resin sheet is not particularly limited. For example, in the case of a prepreg using a glass fiber cloth, 100 to 300 g / m ² is preferable.

In the rectangular parallelepiped in FIG. 1, the upper surface is an open portion, and various processes can be performed depending on the application, and various parts such as flanges and other insert parts can be installed. Moreover, a bolt hole can also be provided in the wall surface of a rectangular parallelepiped as needed, for example. And installation of a flange and other insert parts, drilling of a baltic hole, etc. may be performed after shape | molding a rectangular parallelepiped, or may be performed simultaneously with shaping | molding.

A preferred method for manufacturing a hollow rectangular parallelepiped made of FRP having one surface of the present invention opened will be described. In one method, as shown in FIG. 1, prepregs are used on the front and back surfaces of a rectangular parallelepiped, and the rectangular parallelepiped is cut into strips in the thickness direction of the rectangular parallelepiped. In the manufacturing method of a hollow rectangular parallelepiped made of FRP in which small pieces of prepreg are arranged in a desired thickness, a fiber reinforced resin sheet is covered on at least one of the laminated end faces of the prepreg small pieces. It is the manufacturing method which arrange | positions like this and is integrally molded after that. As the integral molding method, an autoclave molding method or a vacuum bag molding method can be adopted, but the autoclave molding method is preferable. The heating temperature for autoclave molding is suitably from 80 to 200 ° C., and the pressing pressure is suitably from 0.05 to 4 MPa.

Another preferred manufacturing method is as shown in FIG. 2 which is a member formed by dividing the rectangular parallelepiped of FIG. 1 by a cutting plane AB and having two concave parts with horizontal cross-sections facing each other. The members obtained by placing and molding the fiber reinforced resin sheet so as to cover the laminated end surface are laminated on at least one side of the laminated surface of the small pieces of the prepreg laminated on the three ends of the prepreg to be formed. This is a manufacturing method in which the laminated portions of the laminated prepreg pieces are joined to form a hollow rectangular parallelepiped. This will be explained with reference to the drawings. The two members having a concave horizontal cross section contrasting to each other are two members obtained by dividing the rectangular parallelepiped in FIG. 1 by a cross section AB (one of which is shown in FIG. 2). Of a shape like that). The two members are obtained by molding in the same manner as in the case of the integral molding. The two members as shown in FIG. 2 are combined with each other in a face-to-face comparison, and the laminated portions of the laminated prepreg pieces are bolted using an adhesive or using a bolt hole provided in advance. To form a hollow rectangular parallelepiped as shown in FIG.

Hereinafter, the present invention will be described in detail by way of examples.
[Example 1]
The example which manufactured the rectangular parallelepiped as shown in FIG. 1 is shown. Eleven unidirectionally-arranged carbon fiber prepregs (high elastic prepreg, fiber content = 60%, manufactured by Toho Tenax Co., Ltd.) having a length and width of 170 × 1065 cm were laminated and used on the front and back surfaces. On the left and right surfaces, 33 sheets of the same prepreg were cut into strips of 160 × 10.5 cm in length and width. On the bottom surface, 33 sheets of the same prepreg cut into strips of 10.5 × 1065 cm in length and width were stacked. Stack 33 strips of 160 × 10.5cm strips across the short side of a 170 × 1065cm prepreg, and stack 33 strips of 10.5 × 1065cm strips across one end of the long side. The horizontal cross section is a concave member.

Then, a glass fiber cloth (weight per unit area: 200 g / m ² ) was placed on each of the laminated surfaces (three places on the left and right surfaces and the bottom surface) of the laminated prepreg pieces so as to cover the laminated end surfaces. Prepare the same one another, and these two horizontal cross-sections are two members with a glass fiber cloth (fiber reinforced resin sheet) placed on the laminated surface of the small pieces of the laminated prepreg Was autoclaved at 120 ° C. for 2 hours under a pressure of 0.5 MPa. The two members thus obtained were combined for surface control, and the laminated portions of the laminated prepreg pieces were joined by bolting to form a hollow rectangular parallelepiped.

[Comparative Example 1]
A hollow rectangular parallelepiped was formed in the same manner as in Example 1 without using a glass fiber cloth. When water was poured into a rectangular parallelepiped and a water pressure of ² kgf / cm ² was applied, there was no water leakage in Example 1, but water leakage was seen from the left and right surfaces and the bottom surface in Comparative Example 1.

[Example 2]
Using the unidirectionally arranged carbon fiber prepreg of Example 1, a rectangular parallelepiped was made from the beginning in accordance with the method of Example 1, and a glass fiber cloth was placed on the inner surface of both the left and right sides. Were integrally molded under the same conditions as above to obtain a hollow cuboid. This hollow square was also free from water leakage.

The hollow rectangular parallelepiped made of FRP in which one surface of the present invention is opened is a hollow rectangular parallelepiped that does not leak liquid, and can be used for a motor cover of a linear motor, for example, by forming a flange on the opening surface.

It is a figure for demonstrating the hollow rectangular parallelepiped which one surface of this invention opened. It is a figure which shows the member which divided | segmented the rectangular parallelepiped of FIG. 1 by the cross section AB.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front surface of a rectangular parallelepiped 2 Back surface of a rectangular parallelepiped 3 Right side of a rectangular parallelepiped (3a, 3b, ... prepreg strip-shaped piece)
4 The left side of the rectangular parallelepiped (4a, 4b, ... prepreg strips)
5 rectangular parallelepiped bottom (5a, 5b, ... prepreg strips)
6, 7, 8 Fiber reinforced resin sheet

Claims (5)

A hollow rectangular parallelepiped made of FRP having an opening on one side, prepregs are used for the front and back surfaces of the rectangular parallelepiped, and the rectangular parallelepiped is formed on the left and right sides and the bottom of the rectangular parallelepiped in the thickness direction of the rectangular parallelepiped. In a hollow rectangular parallelepiped made of FRP in which small pieces of cut prepreg are arranged in a desired thickness, a fiber-reinforced resin sheet covers the laminated end surface on at least one side of the laminated end surface of the small piece of prepreg A hollow rectangular parallelepiped made of FRP having an opening on one side, which is characterized by being arranged and molded in the same manner. The hollow rectangular parallelepiped made of FRP having one surface opened, wherein the fiber reinforced resin sheet is a glass fiber reinforced resin sheet. A hollow rectangular parallelepiped made of FRP having an opening on one side, prepregs are used for the front and back surfaces of the rectangular parallelepiped, and the rectangular parallelepiped is formed on the left and right sides and the bottom of the rectangular parallelepiped in the thickness direction of the rectangular parallelepiped. In the method of manufacturing a hollow rectangular parallelepiped made of FRP in which cut prepreg pieces are arranged in a desired thickness, a fiber reinforced resin sheet is provided on at least one of the laminated end faces of the prepreg pieces. A method for producing a hollow rectangular parallelepiped made of FRP having an opening on one side, which is arranged so as to cover and thereafter integrally molded. A hollow rectangular parallelepiped made of FRP having an opening on one side, prepregs are used for the front and back surfaces of the rectangular parallelepiped, and the rectangular parallelepiped is formed on the left and right sides and the bottom of the rectangular parallelepiped in the thickness direction of the rectangular parallelepiped. In a method of manufacturing a hollow rectangular parallelepiped made of FRP in which small pieces of cut prepreg are laminated to have a desired thickness, two horizontal members that have a concave horizontal cross section that are face to face with each other, A member obtained by arranging and molding a fiber reinforced resin sheet so as to cover the laminated end face on at least one of the laminated surfaces of the small pieces of the pieces is combined in a face-to-face comparison, and the laminated portion of the laminated small pieces of the prepreg is formed. A method for producing a hollow rectangular parallelepiped made of FRP having an opening on one side, which is formed by bonding to form a hollow rectangular parallelepiped. The method for producing a hollow rectangular parallelepiped made of FRP having one side opened, wherein the molding method is an autoclave molding method.

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