JPS6141528A - Manufacture of erp part - Google Patents

Abstract

PURPOSE:To prevent glass filaments liable to form uneven sections from being locally present thereby making it possible to improve the strength of a product, by placing spacers between sheet materials to be laminated adjacent to tops of uneven parts, and press molding them under heating to integrate the sheet materials and the spacers. CONSTITUTION:After SMC sheets 3...3 are set on a bottom force 2, with the top force and the bottom force 2 heated the top force 1 is moved down, so that the SMC sheets 3...3 and spacers 4, 5 are hot-pressed by the forces 1, 2. Thus, the synthetic resin constituting the SMC sheets 3...3 is softened by the heat and pressure due to the pressing and becomes fluid between the forces, and as a result, the space between the forces is filled with the synthetic resin. Since the spacers 4, 5 are present near the tops of the uneven parts, the movement of filaments 7...7 in the direction of the thickness thereof is prevented. Accordingly, near the parts near the tops of the projections 2a, 2b, that is, projected parts X1, X2 of a product X, the glass filaments 7...7 sandwich the spacers 4, 5 and can be present evenly in the direction of the thickness.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method of manufacturing FRP parts having uneven parts using a laminated material of SMC sheets containing long fibers, such as an engine mount in an automobile. It is used for manufacturing members, etc.

(Prior Art) In recent years, automobile bodies have been required to be lighter and stronger, and attempts have been made to use FRP (glass fiber reinforced plastic) for various parts. The production of this FRP part requires gas!
Generally, a method is adopted in which a molding material called SMC, which is made by integrating fibers and synthetic resin (mainly unsaturated polyester) and molded into a sheet shape, is used and the material is hot press molded. First, a laminate of SMC sheets cut to an appropriate length according to the product is set on a lower mold, and then the SMC sheet is pressed while being heated by an upper mold and a lower mold. Softens the resin in the sheet,
In this way, the above-mentioned laminated materials are integrated to obtain a product having a desired shape.

On the other hand, in order to improve product strength, some SMCs contain long glass 1 (continuous glass cap 1).
When manufacturing FRP parts having uneven parts, such as engine mount members, using this type of SMC, the following problems arise according to the conventional method as described above. That is, as shown in FIG. 9, the upper die A and the lower die B for molding have concave portions A1. A2 and convex portion B1. B2 is formed, but in the vicinity of the protrusions Bt and B2, the SMC sheet C...C has not yet softened when it is set on the lower mold B, so the lower mold B 1. There is a gap Ra between the sheet C...C and the lower mold B without being in close contact with the sheet C. A2 will occur. Therefore, if the molds are matched in this state, the above S
Both ends of the MC sheet C...C are the uneven portions At in the upper mold A and the lower mold B.

A2. B1. B2, and the gap a1. Since it is pressed along the lower mold B so that a2 disappears, the sheet C...C or the sheet C...
Tension is applied to the long glass fibers in C in the longitudinal direction of the product (in the horizontal direction in the drawing). With the glass length 11M stretched in this way, the resin in the 13-8MC sheet C...C gradually softens and becomes fluid by heating and pressurizing both molds A and B. When this happens, the restraint of the resin on the long glass fibers is released, and the long fibers move through the shortest distance in the longitudinal direction of the product due to their own contraction force, and as a result, as shown in FIG. Convex portion B1 of lower mold B (
In the vicinity of the top of Bz), glass length m miscellaneous particles are gathered on the lower mold B side, and a resin-rich portion E where no common sense ND is present is generated in the upper part in the thickness direction of the product. If such a resin-rich portion E exists in the product,
The strength of that part will be weakened and cracks will occur, or in the worst case, the product will be damaged.

As will be described later, in the method of the present invention, other members are sandwiched between SMC sheets and integrated, but a similar method in this respect is disclosed in Japanese Patent Application Laid-Open No. 56-25417.
There is a method published in the publication. However, what is published in this publication is a method in which a porous material such as a fiber knitted fabric is integrated by interposing a resin felt between reinforcing sheets impregnated with a synthetic resin (e.g., niacryl resin). This method does not prevent the uneven distribution of the composition, that is, the generation of resin-rich portions, which occurs during press molding of SMC sheets, and therefore, the purpose is completely different from the present invention.

(Object of the Invention) The present invention addresses the above-mentioned problems during press processing of SMC mixed with long glass fibers, and is intended to solve the above-mentioned problems during press processing of SMC mixed with long glass fibers. The purpose of the present invention is to prevent uneven distribution of long glass fibers, which tends to occur in the uneven portions, when molding, thereby improving the strength of the product.

(Structure of the Invention) In order to achieve the above object, the method for manufacturing an FRP component according to the present invention is characterized by having the following structure.

That is, in a method of hot press molding a part having uneven parts using a laminated material of SMC sheets containing long fibers,
□A spacer is interposed between the sheet laminate near the top of the uneven portion, and then hot press molded to integrate the sheet laminate and the spacer. The above-mentioned spacer is made of, for example, a steel plate material having a large number of communication holes, and synthetic resin and glass aim softened during press molding are passed through the communication holes, but long glass fibers are passed through the spacer. This acts to prevent the upper and lower layers from moving between the sheets. Therefore, even if the long glass fibers are stretched in the longitudinal direction of the product during press molding, the spacer prevents the long fibers from moving in the thickness direction when the synthetic resin releases the restraint on the long fibers. It will be blocked. This prevents uneven distribution of the glass length IIm and the occurrence of resin-rich portions, making it possible to obtain a product with a uniform composition.

(Example) Examples of the present invention will be described below.

This embodiment has convex portions XI on both ends as shown in FIG.
This relates to the case of manufacturing a product (engine mount member) And the lower mold 2 has the above-mentioned convex portion X1. Four parts la to mold X2.

1b and convex portions 2a and 2b are formed, respectively.

Then, the product X is press-molded using the upper mold 1 and the lower mold 2.
First, the C sheets 3...3 are cut to an appropriate length according to the product, and then set on the lower mold 2. At this time, the above-mentioned convex portion X1. The part that becomes X2 (the convex part 2a of the lower mold 2,
2b), the SMC sheet 3...3
Spacers 4 and 5 are interposed between them. As shown in Fig. 3.4, this spacer 4 (the same applies to the spacer 5) has a large number of communicating holes 4a...4a (5a ...
5a), and is formed in a shape that follows the convex portion 2a of the lower die 2. The number of SMC sheets 3...30 may be increased or decreased depending on the thickness of the product, but in this embodiment, two sheets are stacked one above the other with the spacer 4 in between.

However, after setting the SMC sheets 3...3 on the lower mold 2 as described above, the upper mold 1 is moved downward while the upper mold 1 and the lower mold 2 are heated. 3...3 and the spacer 4.5 are hot pressed using both dies 1 and 2. As a result, each of the above SMC sheets 3...
- The synthetic resin composing 3 is softened by the heat and pressure associated with pressing and flows within the mold, and as a result, the space within the mold is filled with the synthetic resin 6, as shown in Figure 5. be. At this time, the long glass fibers 7...7 contained in the SMC sheets 3...3 are released from the restraint by the synthetic resin 6, but tension is applied to the long fibers 7...7 during mold clamping. Therefore, when the restraint is released, the product tries to pass the shortest distance in the longitudinal direction, and the convex part 2a (2
b) It tries to move towards the lower mold 2 side in the thickness direction near the top. However, since the spacer 4 (5) is interposed near the top, the movement of the common sense 1i7...7 in the thickness direction is prevented. Therefore, the convex portion 2a (
2b), that is, the convex portion XI (X2
), the long glass fibers 7...7 sandwich the spacers 4 (5) and are evenly distributed above and below.

As a result, the convex portion X1 of the product X. Uneven distribution of resin in X2, that is, generation of a resin-rich portion, is prevented.

Here, the synthetic resin 6.6 that exists above and below the spacer 4.5 is the communication hole 4a...4a of the spacer 4,5,
By being continuous by 5a...5a, product X
Convex portion X1. X2 prevents peeling on both the front and back sides.

In the above embodiment, the spacer 4.5 made of steel plate is
However, as shown in Fig. 6, a spacer 4' made of an SMC sheet with a high content of short glass fibers was used.
This may prevent the long glass fibers contained in the upper and lower SMC sheets 3'...3' from moving in the thickness direction.

Next, an experiment conducted to confirm the effects of the present invention will be briefly described.

As shown in Fig. 7, with both ends of product was measured.

As a result, as shown in the graph of FIG. 8, the product X according to the present invention has a greater displacement under the same load than the product In other words, the rigidity was significantly increased, and the maximum load that could be applied was also increased by approximately 150 times, which confirmed that the strength was significantly improved. Product X uses a spacer made of a steel plate.In addition, both Product X according to the method of the present invention and Product X' according to the conventional method also contain 5 awt% of glass long fibers and 10wt% of short glass fibers. It includes each.

(Effects of the Invention) As described above, according to the present invention, when a part or product having an uneven portion is molded using SMG containing long glass IIM, long glass fibers that are likely to be formed in the uneven portion can be removed. As a result, the strength of the product is improved and cracks in resin-rich areas are prevented.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a product manufactured by the method of the present invention, Fig. 2 is a schematic view showing the state in which the SMC sheet is set on the lower die in the embodiment, and Fig. 3 is A schematic sectional view showing an enlarged view of a steel plate spacer interposed between SMC sheets, Fig. 4 is a perspective view of the spacer in Fig. 3, and Fig. 5 shows the area around the convex part of the lower die during hot pressing. Figure 6 is an enlarged schematic cross-sectional view of the main part showing the state in which an SMC sheet with a high content of short glass fibers is used as a spacer, and Figure 7 is about an experiment conducted to confirm product strength. 8 is a graph showing the product strength characteristics obtained by the experiment in comparison with the conventional example, and FIG. 9 is a schematic cross-sectional view used to explain the conventional method of manufacturing FRP parts. FIG. 10 is an enlarged sectional view of the main part used to similarly explain the problem. 3.3'...SMC, 4,4', 5...Spacer, 7...Long fiber, X...Parts (product), Xl, X2
...Uneven parts (convex parts).

Claims (2)

[Claims] (1) A method of hot press molding a part having uneven parts using a laminated material of SMC sheets containing long fibers, the method comprising:
A spacer that prevents the movement of long fibers between the upper and lower sheets is interposed between the sheet laminate near the top of the uneven portion, and then hot press molded to integrate the sheet laminate and the spacer. A method for manufacturing FRP parts, characterized by: (2) The method for manufacturing an FRP component according to claim 1, wherein the spacer is a steel plate material having a large number of communicating holes.