JPH05338037A - Foam core composite molded product processing method - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a method for forming a strong screw hole or a stud for a composite molded article in which a foamed rigid foam is used as a core and the periphery of the core is covered with a resin reinforced with a fiber. To do. [Structure] A hole having a diameter larger than a bolt diameter is formed at a predetermined position of the composite molded article, and a bolt is inserted into the hole,
The void between the bolt and the inner wall of the hole is filled with the thermosetting resin composition and cured in that state. If the bolt is left as it is, it becomes a stud, and if the bolt is removed, a screw hole is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite molded article (hereinafter referred to as a foam core composite molded article) in which a foamed rigid foam is used as a core and the periphery of the core is covered with a resin layer reinforced with fibers.
The present invention relates to a method of constructing a stud bolt or a screw hole.

More specifically, a resin composition containing a thermosetting resin as a main component which is liquid at room temperature and which is easy to handle is used to easily and mechanically bond to the above composite molded article. The present invention relates to a method of constructing bolts and screw holes.

[0003]

2. Description of the Related Art In recent years, a foam core composite molded article in which a resin (FRP) layer around a core made of foamed rigid foam is coated with a fiber is excellent in lightness and toughness. It has been put to practical use in various fields such as the field of supplies.

When this foam core composite molded article is to be connected to other members, it is necessary to provide a screw hole in the molded article and insert a bolt therethrough, or to provide a stud bolt and bolt it. .. However, when performing these threaded parts on such a molded product, since the core layer is a foamed hard foam such as polyurethane with low mechanical strength, simply performing a normal tapping process will not There is a problem that mechanical strength is low and bolting cannot be effectively performed.

[0005]

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to provide a foam-core composite molded article by using a resin composition containing a thermosetting resin as a main component, which is excellent in handleability, and can be easily machined. It is intended to provide a method for processing a threaded portion excellent in dynamic strength (construction of a screw hole or construction of a stud). Other objects of the present invention will be apparent from the following description.

[0006]

Means for Solving the Problems As a result of intensive research to achieve the above-mentioned object, the present inventors have found that when an implant bolt is applied to a foam core composite molded product, the molded product has a diameter larger than the bolt size. The hole is drilled, the bolt is arranged at a predetermined position in the hole, the void between the inner wall of the hole and the outer circumference of the bolt is filled with a composition mainly composed of a thermosetting resin, and the bolt is cured by curing in that state. Can be firmly fixed, and
When constructing a screw hole, a screw hole forming bolt was used in place of the above-mentioned stud bolt, and it was found that a strong screw hole is formed by removing the bolt after hardening, and thus the present invention was reached.

That is, according to the processing method of the present invention, (1) when an implant bolt is applied to a composite molded article obtained by covering a core of foamed rigid foam with a resin reinforced with fibers and curing the core, A hole having a diameter larger than the diameter of the stud to be constructed is formed in the molded product, the stud is arranged at a predetermined position in the hole, and the void between the hole and the bolt is mainly made of a thermosetting resin. Filling with a resin composition as a component and fixing the bolt by hardening the resin composition, and (2) a foamed rigid foam as a core When a screw hole is formed in a composite molded product obtained by coating the periphery of the core with a resin layer reinforced with fibers and curing, a hole having a diameter larger than the diameter of the screw hole to be processed is formed in the molded product, Align it in place in the hole. A bolt having a size corresponding to a hole is arranged, and the void between the hole and the bolt is filled with a resin composition containing a thermosetting resin as a main component, and the resin composition is cured, and then the bolt is used. By removing
A method for processing a foam core composite molded article, which comprises forming a screw hole.

The composite molded article to which the processing method of the present invention is applied is conventionally known, and is typically a structure comprising a reinforcing fiber such as carbon fiber, glass fiber or aramid fiber around a rigid polyurethane foam. A woven or knitted product, a UD sheet, a braided product, etc. are arranged, and a matrix resin made of a thermosetting resin or a thermoplastic resin is impregnated and solidified in the foam core composite molded product. The shape of this molded product can be a plate, a bar, or any other shape,
It is desirable that at least the thickness of the portion to be processed is equal to or greater than the thickness corresponding to the bolt length.

According to the processing method of the present invention, when the stud bolt or the screw hole is formed in the foam core composite molded article, first, the composite molded article has a predetermined position (that is, a position to be processed). Then, a hole (prepared hole) having a diameter larger than the diameter of the stud bolt or the screw hole is bored. It is preferable that the depth of the prepared hole is approximately the same as the threaded hole to be constructed in the case of threaded hole processing, and is approximately the same as the length of the implanted portion of the bolt in the case of stud bolting.

In the present invention, the bolt is arranged in this pilot hole. The bolt is usually inserted into the prepared hole so as to be perpendicular to the surface of the molded product, but the insertion angle may be changed depending on the installation direction of the screw hole or the stud. And
Before and / or after the insertion of the bolt, the thermosetting resin composition is put in the pilot hole, and the void between the inner wall of the pilot hole and the outer circumference of the bolt is filled with this composition.

The thermosetting resin composition used in the present invention is mainly composed of an unsaturated polyester resin, a vinyl ester (epoxy acrylate) resin, an epoxy resin and the like which are liquid at room temperature from the viewpoints of handleability and cost. Is used.

Further, while adjusting the viscosity of the resin liquid,
In order to improve the mechanical strength of the threaded portion to be applied, it is preferable to add glass beads or inorganic particles such as calcium carbonate to the resin. In this case, the compounding ratio of the resin and the inorganic particles may be in the range of 1/10 to 10/1 by weight, and particularly preferably 1/5 to 2/1.

In the present invention, as the thermosetting resin composition, for example, a resin capsule type anchor bolt fixing material having a two-chamber structure known by a registered trademark of "Bolt Mate" (manufactured by Teijin Ltd.) can be preferably used. That is, this anchor bolt fixing material is disclosed in JP-B-56-18444, JP-B-56-20439 and JP-A-1-13.
As described in Japanese Patent No. 7100, etc., a resin capsule anchor having a double structure in which an unsaturated polyester resin, a curing agent, and glass beads are housed in a thermoplastic resin tube, and the package is further enclosed in a glass tube. Is.

When such an anchor bolt fixing material is used in the present invention, the anchor bolt fixing material is first inserted into the prepared hole, and then the tip portion thereof is 10 ° to 80 ° with respect to the bolt rotating shaft from above. , Preferably 20-60 °
Using a stud bolt having a shape notched at an angle of, insert the bolt into the prepared hole containing the anchor bolt fixing material in advance while rotating the bolt. By doing so, the glass tube of the anchor bolt fixing material is broken by the bolt, and the resin, the curing agent, and the beads are mixed, and the void between the outer circumference of the bolt and the inner wall of the prepared hole is filled with this resin composition and cured. ..

When applying a stud, the object of the present invention can be achieved by removing excess resin protruding from the pilot hole and then hardening it. However, when drilling a screw hole, the resin is hardened. After that, when the bolt is pulled out while being rotated counterclockwise, a thread groove of the bolt is formed on the inner peripheral surface of the hole, and a screw hole corresponding to the dimension of the bolt is formed.

In the present invention, one bolt is usually inserted into one prepared hole, but in some cases, a plurality of bolts may be inserted into a prepared hole having a large diameter.

[0017]

As described above, according to the present invention, it is possible to easily install a stud bolt or make a screw hole in a foam core composite molded article, and the obtained screw portion has dimensional stability and mechanical strength. And is useful as a method for constructing a connection between a foam core composite molded article and another member.

[0018]

The present invention will be described in detail below with reference to examples.
The examples are for purposes of illustration and the invention is not limited thereto.

[0019]

Example 1 A unidirectionally aligned carbon fiber (C-250 manufactured by Ankarev, USA, fiber weight: 250 g / m ² ) was added to a rigid urethane foam having a rectangular cross section of 52 mm × 42 mm.
After winding the layers, a preform whose outer periphery was covered with one layer of a braided body of carbon fibers was put in a mold, and a liquid molding resin (“Epiclon” manufactured by Dainippon Ink and Co., Ltd. 8
30, "Epicure" 113) made of oiled shell epoxy was injected, and heated at 150 ° C. for 1 hour to cure. The cross-sectional shape of the obtained composite molded product is a rectangle of 60 mm x 50 mm,
The fiber volume content (Vf) of the skin layer (FRP layer) is 55.
%Met.

Next, a prepared hole having an inner diameter of 10 mm and a depth of 40 mm was bored in the foam core composite molded article.

On the other hand, 100 parts by weight of an unsaturated polyester resin (manufactured by Nippon Yupica) as a resin composition, 400 parts by weight of glass beads (GB-S01MC manufactured by Toshiba Ballotin Co., Ltd.) having a particle size range of 840 to 1190 μm as an aggregate, fine calcium carbonate. 10 parts by weight were mixed. This was mixed with 2 parts by weight of benzoyl peroxide and 0.1 part by weight of dimethylaniline, and immediately filled in the prepared hole provided in the foam core composite molded article, and subsequently, M8 bolt was inserted to the bottom of the prepared hole, The excess resin composition was removed. After the resin composition filled in the prepared hole was cured, the bolt was extracted while rotating counterclockwise, and a strong screw hole portion was obtained in the composite molded product.

Further, when the pulling load was measured one day after the bolt was fixed to the foam core composite molded article,
The maximum drawing load was 198 kg / f.

[0023]

[Example 2] "Epicoat" 828 which is an epoxy resin
100 parts by weight of (oiled shell epoxy) and 20 parts by weight of "Epicure" T (made of oiled shell epoxy) were mixed to prepare a thermosetting resin composition.

M8 bolts were previously placed in the pilot holes of the foam core composite molded article having the pilot holes shown in Example 1, and the resin composition was filled in the voids between the pilot holes and the bolts. , Cured. After curing, the bolt was removed in the same manner as in Example 1, and a good threaded portion was obtained.

Further, when the pulling load was measured one day after the bolt was fixed to the foam core molded product, it was found to be 142.
The maximum drawing load of kg / f was shown.

[0026]

[Example 3] A commercially available resin capsule anchor "Bolt Mate" (manufactured by Teijin Ltd.) was inserted into the prepared hole of the foam core composite molded article having the prepared hole shown in Example 1.
Then, an M8 stud bolt, the tip of which was cut out at an angle of 30 degrees with respect to the rotation axis of the bolt, was attached to an electric hammer drill, and was inserted to the bottom of the prepared hole while giving a rotational impact. The "bolt mate" hardened in about 10 minutes, and the stud was firmly fixed to the composite molded product.

The pulling load of the bolt after one day was measured. As a result, the maximum drawing load of 195 kg / f was shown.

[0028]

COMPARATIVE EXAMPLE The foam core composite molded article shown in Example 1 was directly tapped with a depth of 60 mm to form a bolt hole, and a bolt was inserted into the hole, and then the pulling load was measured. As a result, the maximum drawing load was only 47 kg / f, which was insufficient for connecting the composite molded article to other members.

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Claims (4)

[Claims] 1. When applying an implant bolt to a composite molded article in which a foamed rigid foam is used as a core, and the periphery of the core is covered with a resin layer reinforced with fibers, the diameter of the implant bolt to be applied to the molded article is A large-diameter hole is bored, an implant bolt is arranged at a predetermined position in the hole, and a void portion between the hole and the bolt is filled with a resin composition containing a thermosetting resin as a main component. A method of processing a foam core composite molded article, comprising fixing the bolt by curing a resin composition. 2. When a screw hole is formed in a composite molded article in which a foamed rigid foam is used as a core and the periphery of the core is covered with a resin layer reinforced with fibers, the diameter of the threaded hole to be formed is determined in the molded article. A large-diameter hole is bored, a bolt having a size corresponding to a screw hole is arranged at a predetermined position in the hole, and a void portion between the hole and the bolt has a resin composition containing a thermosetting resin as a main component. Then, the resin composition is cured, and thereafter,
A method for processing a foam core composite molded article, which comprises forming a screw hole by removing the bolt. 3. The method for processing a foam core composite molded article according to claim 1, wherein the resin composition containing a thermosetting resin as a main component is a mixture of a liquid thermosetting resin and inorganic particles. 4. A resin composition comprising a thermosetting resin and inorganic particles contained in a thermoplastic resin tube,
In addition, the one whose package is enclosed in a glass tube is used, and as the bolt, the tip end on the side embedded in the resin mixture is 10 to 80 with respect to the rotation axis of the stud.
A bolt having a shape notched at an angle of ° is used, the resin composition containing the glass tube is inserted into a hole formed in a molded product, and then the bolt is inserted into the hole while rotating. The method for processing a composite molded article according to 2 or 3.