JPS6147221A - Manufacture of molded body - Google Patents

Abstract

PURPOSE:To manufacture a FRP molded product having through holes and the like only by means of a course of molding processes with no development of weld-mark by a method wherein the forming of the through holes and the like are done by additional holding jigs within a short period of time lasting from the molding of a main body to the gelation of molding material. CONSTITUTION:The molding material 4 charged in a bottom force 2 is filled by flowing in a cavity 3 by means of the pressure applied with a top force 1. Holding or insert molding is done by pushing holding or insert jigs into the mold within a short period of time after the completion of the filling of the molding material. The holding jigs 6 and 7 are finally pulled back to their initial positions with auxiliary pressing mechanisms. After the mold is open by a main pressing mechanism, a molded body 5 is taken out of the mold by pushing up knockout jigs 8. Thus, the molded body 5 having through holes 16 and 17 can be manufactured only by molding operation.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for reducing the penetration rate required when molding a thermosetting resin molding material or a thermoplastic resin molding material (hereinafter collectively referred to as FRP) reinforced with glass fiber or the like. Molding holes, blind holes or inserts at the same time. The present invention relates to a method for manufacturing a molded article.

[Technical background of the invention and its problems]

Recently, FRP reinforced with glass fiber or the like has been widely used as a structural material that also serves as electrical insulation, especially in fields related to heavy electrical machinery, due to its excellent mechanical and electrical properties.

However, since FRP contains fibers, its moldability is generally inferior to that of forming materials that do not contain fibers.

In particular, when the molded product includes through holes, blind holes, inserts, etc., the flow of the molding material is branched by the molding pin set in the mold or the hardware inserted, resulting in fiber orientation (FR fibers are flat). A phenomenon in which the fibers flow in the opposite direction and the fibers become less intertwined) occurs, and linear so-called weld marks are generated, which often leads to deterioration in appearance, mechanical and electrical lζ performance.

Weld mark countermeasures include consideration of the mold structure including the position and size of the gate, consideration of the position when charging the molding material into the mold, flow rate of the molding material within the mold, curing reaction speed, etc. Studies have been conducted on molding conditions such as molding temperature, molding pressure, die cutting, transfer, and injection speed in order to make the molding process appropriate. It is difficult to implement it perfectly due to the conditions, and in many cases the result is only a slight improvement in appearance and properties.

4! ! Measures against the case where the molding hole is located at the end of the flow of the molding material in i- are almost impossible due to factors such as curing reactions.

On the other hand, molding holes and inserts often serve as stress concentration points that support loads due to the structure of the molded product, and therefore a manufacturing method that does not deteriorate properties during molding is required.

Another measure against weld marks is post-processing, which involves machining after molding.

In this case, the weld mark itself can be prevented, but the additional processing steps pose problems in terms of equipment, working time, and cost.Furthermore, there are problems such as deterioration during processing and a decrease in strength due to the ant cutout effect.

[Purpose of the invention]

The present invention molds through holes, blind holes, inserts, etc., and thereby welds an FRP molded body including through holes, blind holes, inserts, etc. with only a series of molding steps. It is an object of the present invention to provide a method for producing a molded article that can be molded without producing marks.

[Summary of the invention]

The present invention provides a method for producing a molded body having a through hole, a blind hole, or an insert using a thermosetting resin molding material or a thermoplastic resin molding material containing reinforcing fibers. The main molding process involves filling and pressurizing a metal molding material that corresponds to the shape, and then pressing a hole-drilling or insert jig into the metal molding to perform hole-drilling or insert molding within a short time after the filling is completed. This makes it possible to manufacture a molded body including through holes, blind holes, inserts, etc. without producing weld marks by only a series of molding steps.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG.

Fig. 1 (gradient indicates the process of forming only the main body, Figure j11 CB) shows the process of forming the through hole following the main body forming.

In FIGS. 1(f) and (b), the molding material 4 charged in the lower mold 2 is pressurized by the upper mold 1 connected to the main press mechanism of the molding machine (not shown) and flows inside the cavity 3. When it is filled and the plate spacing is completed, it will be in the state M shown in Figure 1 (6).
lζ is formed.

In this case, the through-hole molding jigs 6 and 7 are pulled back, so the molding material 4 can be applied in the gap between the upper mold 1 and the lower mold 2 without being abraded during the process. Since it is molded, there are no weld marks.

Next, in the state shown in FIG. 1 (4) above, using the auxiliary press mechanisms 11 and 12, the vertical hole is made using the jig 6, and the horizontal hole is made using the jig 7.
When pressed into the molding material 4, the vertical holes 16 and the horizontal holes 17 are formed, and the desired molded body 5 is completed by continuing pressurization and heating for a predetermined molding time.

For drilling, the jigs 6 and 7 are the final auxiliary press mechanism U.

The molded body 5 is taken out.

As a result, the FRP molded body 5 including the through holes 16 and 17 can be manufactured only by a molding operation without producing weld marks.

C Effects of the Invention] An example of the effects of the invention will be described with respect to the case of manufacturing the molded body 5 shown in FIG. 2.

For the comparative test, the test piece was the horizontal hole 1 of the molded body 5 shown in Fig. 2.
It was taken out from the part 21 adjacent to 7.

In the comparative test, a molding material of unsaturated polyester BMC was closed with the molds 1 and 2 shown in FIG. 1 (6) above, pressurized, heated,
A test piece from the cured and released molded body is used as a first test piece,
Similarly, the molding material of unsaturated polyester BMC was
As shown in Figure CB), the test piece from the molded body was filled with the metal parts 1 and 2 with the jig 6.7 pushed in, pressed, heated, hardened, and exfoliated. JI5K 6 as a test piece
The bending strength was compared using the standard test method of 911.

The test results showed that the bending strength of the first test piece was 8.9 to 11.0KF.
/
It was confirmed that the bending strength was approximately three times greater when the method of the present invention was used.

Further, while weld marks were observed in the second test piece, no weld marks were observed in the I test piece.

Note that to drive the jigs 6 and 7, an auxiliary press in any direction including the same direction, opposite direction, and right angle direction as the main press mechanism is used separately from the press mechanism of the knockout jig 8 for taking out the compact. can be used, increasing the degree of freedom in work.

As explained above, according to the present invention, a through hole, a blind hole, an insert, etc. are formed using another hole shaping jig immediately after the main body is formed, within a short time until the molding material gels.
This eliminates weld marks and allows molding of parts including through holes, blind holes, inserts, etc. with just a series of molding steps.
y molded products can be manufactured.

Note that the present invention can also be effectively applied to ordinary molded bodies that do not contain reinforcing fibers.

[Brief explanation of the drawing]

FIG. 1 (-, (B) is a work process diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing a method of cutting out a test piece to demonstrate the effects of the present invention. 1 Upper mold 2 Lower mold 3 Cavity 4 Molding material 5 Molded object 6.7 Hole marking jig 8 Knockout jig 10.11.12 Press mechanism 16.17 Through hole 21 Test piece (8733) Representative patent attorney Yoshiaki Inomata (et al.) 1
Name) Part 2 Figure 1 Mu? /

Claims (1)

[Claims] In a method for manufacturing a molded body, the method comprises manufacturing a molded body having a through hole, a blind hole, or an insert using a thermosetting resin molding material or a thermoplastic resin molding material containing reinforcing fibers,
The main molding process involves filling and pressurizing a molding material into a mold corresponding to the body shape of the molded object, and then pressing a hole-drilling or inserting jig into the mold within a short time after the filling is completed. A method for producing a molded article comprising an auxiliary molding step of molding or insert molding.