JPS59209827A - Manufacture of fiber reinforced plastic structural member - Google Patents

Abstract

PURPOSE:To make a corner of a structural member have a precise angle, by making the corners of molding surfaces of molds a little larger than 90 deg. so that the corner of a structural member placed in combined molds has an angle that allows the deformation after the molding. CONSTITUTION:The corner angles beta of molding surfaces of a top force 10 and side forces 20 are 90 deg. or more, and the opposite molding surfaces of the molds are parallel so that beta -90 deg. is an angle that allows the deformation of the intended structural member. The allowance angle beta -90 deg. of the molds is determined in accordance with the thermal stress that will depend on the thickness and the size of the intended structural member, the rigidity of the reinforcing fiber, etc., and is most preferably on the order of 0.5 deg..

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a fiber reinforced plastic (FRP) structural material that is lightweight and has excellent impact resistance, particularly a fiber reinforced plastic (FRP) structural material that is reinforced with continuous fibers and that is perpendicular to the longitudinal direction. The present invention relates to a method for producing a fiber-reinforced plastic structural material having a right-angled intersection or a right-angled bend in a part of its cross section.

(b) Conventional technology F with a part of the cross section at right angles and bends
Manufacturing methods for RP structural materials, such as structural materials having a T-shaped cross section, a ■ or H-shaped cross section, an equilateral or scalene chevron (L-shaped) cross section, and a groove-shaped cross section such as a U-shape, include pultrusion molding, press molding, etc. method, vacuum injection molding method, etc. The present invention is effective for press molding and vacuum injection molding.

First, to explain the conventional method that is the object of improvement of the present invention based on FIGS. 1 to 4, in the molding of T-shaped material A as shown in FIG. For the ■ or H-shaped material A′ shown in FIG. 2, the upper mold 1 (square molds 2, 2 and lower mold 3) In the molding of the channel-shaped material A''' shown, the mold 1 and the lower mold 3 are combined,
In the case of press molding, a laminated product such as prepreg (resin-impregnated cloth) is placed between these combination molds and pressurized and heated to obtain a structural material with a desired cross-sectional shape. On the other hand, when performing vacuum injection molding, first, only reinforcing fibers are stacked in the direction required for design and manufacturing between the same molds as above, and then the whole is vacuum sealed and resin is placed between the stacked fibers. The laminate is then heated and cured.

(C) Problems to be Solved by the Invention However, in the above-mentioned method, although the corner angle of the molding surface of the mold for forming the right-angled portion of the structural material is set to 90°, the intersection of the structural material and the It is not possible to make the bent part exactly 90 degrees (α in Figure 1 is about 89 degrees), which may cause problems such as problems in assembling other parts or creating gaps after assembling. Something is happening.

2) Means for Solving the Problems The present inventors believe that the reason why the angle of the intersection or bend of the structural material, which was kept at 90° during molding, becomes smaller after molding is due to FRP.
The present invention was developed after discovering that structural materials undergo slight deformation due to thermal residual stress during heat curing.The purpose of the present invention is to accurately square structural materials. The goal is to do the following. In addition, the feature is that the corner angle of the molding surface is made slightly larger than 90°, and the right angle part of the structural material placed between the combined molds is molded at an angle that takes into account the amount of deformation after molding. It's there.

That is, as shown in FIGS. 5 to 8, the molds used in the present invention have corner angles β of the molding surfaces used for molding the right-angled portions of the upper mold 1o, the horizontal mold 20, and the lower mold 30. 90° or more,
And the opposing molding surfaces of each mold are parallel, β-9
0° is the expected angle that absorbs the deformation of the structural material.

Note that the expected angle to be attached to the mold is determined in consideration of the fact that the amount of thermal stress deformation may change depending on the thickness and size of the structural material, the rigidity of the reinforcing fibers, etc. The results of trial production of CFRP (carbon fiber reinforced plastic) structural materials with different thicknesses show that when β is set to 90.5°, the angle of the intersection or bend is 90°, and when β is set to 91°, the angle is 90°. , the right angle part of the structural member is 90.5°. Therefore, it is considered most desirable that the angle of view is about 0.5°, but it is not limited thereto.

[Example 1] The corner angle β of the molding surface of the mold shown in Fig. 7 was set to 90.5°±
5', 30 sheets of carbon fiber cloth impregnated with epoxy resin (Toshi Trading Card #6341) are stacked and placed between the upper and lower molds 10 and 30, and then pressurized at commonly used pressures and temperatures.・Heat to 10mm thick, side length 200mm
A chevron-shaped structural member having a width of 200 mm and a length of 300 mm was obtained. When the angle of the bent portion of this structural material was measured, it was found to be exactly 90°.

[Example 2] The corner angle β of the molding surface of the mold shown in Fig. 8 was set to 90.5° ±
As 5', nine sheets of the same resin-impregnated cloth as above were stacked between the upper and lower molds 10 and 30, and they were pressed and heated to produce a groove-shaped structural material with a wall thickness of 3 mm. When measured, the angle was 90°.

(Effects) As explained above, according to the present invention, the angles of the intersections and bends of the FRP structural material can be accurately set to 90 degrees, and therefore, the angles of the intersections and bends of the FRP structural material can be accurately set to 90 degrees. Materials can be combined and bonded easily, eliminating the need for liner adjustment, etc.

[Brief explanation of the drawing]

Figures 1 to 4 are all based on the conventional method 1; RP
5 to 8 are cross-sectional views showing the state of molding of the structural material, and are schematic front views of the mold used in the method of the present invention. 10...Upper mold, 20...Horizontal mold, 30...Lower mold Patent applicant Sumitomo Electric Industries, Ltd. Agent Kama 1) Text 210 10 Figure 3 1 Measure 4 Figure 7 Figure 8 0 133

Claims (1)

[Claims] The corner angle of the molding surface used for press molding of fiber-reinforced plastic structural materials having a right-angled intersection or right-angled bend in a part of the cross section or right-angled instant molding of a vacuum injection molding mold is 90' or more. A method for manufacturing a fiber-reinforced plastic structural material, characterized in that the right angle part of the structural material placed between the combined molds is formed at an angle that takes into account the amount of deformation due to thermal residual stress after molding.