KR810001069B1 - Method of outsert injection molding - Google Patents

Abstract

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Description

Out sert molding method

1 is a perspective view showing an example of an undercut functional part.

2 is a cross-sectional view showing a conventional mold structure for molding a resin functional part having the same shape as that in FIG.

3 and 4 are front and side views showing, in cross section, a relationship between a mold and a substrate before molding in the present invention.

5 and 6 show the clamping end positions of the mold corresponding to FIGS. 3 and 4, respectively.

7 is a perspective view of a molded article according to the method of the present invention obtained by filling a mold shown in FIGS. 5 and 6 with resin.

8 is a perspective view of the forming wind according to the method of the present invention in which the resin layer around the cutout portion of the substrate is deformed.

9 is a partially enlarged cross-sectional view thereof.

The present invention relates to an out sert molding method using a core mold.

Background Art [0002] Parts having a large number of functional parts on a substrate, such as a tape recorder chassis, have been manufactured by attaching a component on a substrate by a complicated sheet metal processing or assembly process. In recent years, due to advances in the application technology of so-called engineering plastics, which have characteristics required for various functional material such as strength and friction resistance, such functional parts are made of resin on a substrate made of hard materials such as metal. It became possible to manufacture by the special insert molding method provided by one molding operation.

In this molding method, since resin is inserted into the metal as opposed to conventional insert molding, it is called an outer insert molding method. Since the outer assist method has a small number of processing steps, the effect is very large, such as a low processing cost and a low generation of defective products. However, since there is a special thing called a substrate, various special ideas are required to apply conventional molding techniques. in need.

The present invention relates to a new technique for applying a molding method using a core mold to an outer seat system.

Core molds are particularly useful for undercut shaped articles. For example, when forming the functional part 2 on the board | substrate 1 like FIG. 1, since the molding is impossible with the simplest 2 sheet metal mold | die, a transverse sliding core is generally used. Therefore, if this technique is applied in the outer assist method, the mold for the resin functional part 2 of FIG. 1 will have a structure like FIG. That is, in FIG. 2, (A) is a slide core and moves in the direction of an arrow. (B) (C) is a mold of a mold, (D) is a substrate, and (E) is a cavity filled with resin. However, this method is not preferable for the reason described below. First of all, this method is not applicable when there is a function to prevent movement in that direction because the nose A moves in the direction of the cavity E. In many cases, however, many functional parts are molded on the substrate. So this constraint is significant.

Moreover, since the precision of the board normally used is not so high, there is also a risk of damaging the core in the slide.

The present invention relates to a novel molding method for imparting a functional part to the substrate by an outer-assert method using a core mold which can be easily applied to undercart-shaped parts and the like without such a difficult drawback.

The method of the present invention uses a substrate having a hole cut out at a position of a functional part, the mold having the hole having both functions of a passage and a cavity of the core, that is, a mold formed by a core penetrating the cut hole. By using, it is characterized in that the molding of the functional part of the synthetic resin to the hard substrate.

Referring to the drawings, functional parts are obtained as shown in FIG. 7 by the method of the present invention as shown in FIG.

3 and 4 show the relationship between the substrate and the mold before molding, and FIG. 3 is a front view and FIG. 4 is a side view thereof.

(A＇)내로 이동한다. 형체종료 위치를 제5도 및 제6도에 표시하지만, 제5도는 제3도에, 제6도는 제4도에 대응된 그림이다.That is, the middle core A is installed in the lower die plate 6, and penetrates the notch B of the substrate by the mold, and the upper die plate 5 side.

Go to (A '). Although the end position is shown in Figs. 5 and 6, Fig. 5 corresponds to Fig. 3 and Fig. 6 corresponds to Fig. 4. Figs.

Although a cavity is formed between the upper plate 5 and the lower plate 6, the middle part is a cavity which characterizes this invention, and (b) is a cavity of a normal functional part.

That is, by the shaping | molding operation, resin is filled in these cavities and the molded article 2 which has the resin frame 4 of width t around the notch B of the board | substrate 1 is obtained like FIG. . Thus, in the method of this invention, since the hole provided in the board | substrate is used in the channel | path of a core different from the slide core system normally used, especially when giving an under-cart-shaped functional part on a board | substrate like FIG. 1, As described above, the mold structure is simplified and the operation becomes very easy as compared with the conventional method.

In addition, the design cost is much reduced compared to the conventional method. Another feature of the present invention is to use a substrate cut into a shape in which a space in which resin can be filled is provided between the core and the cutout portion, whereby a resin layer is provided around the cutout portion. The lower limit of the width of the resin layer (t in FIG. 3) is determined from whether the degree of the substrate should be taken into account, and whether or not the width is sufficient to sufficiently fill the resin, and whether the shape is stable after molding.

In the case of outer assist molding, functional parts such as acetal resins are often given to a substrate having a thickness of about 0.5 mm to 5 mm (usually about 1 mm), but in this case, the width t is 0.2 mm or more, preferably 0.5 mm to 1 About mm is suitable. Although the upper limit of the width | variety t is not specifically limited, 5 mm or more is unpreferable because large diameter reduces the board | substrate intensity | strength, and therefore requires expensive resin. In addition, the width t does not need to be recognized over the entire periphery of the resin layer.

Preferably, as shown in FIG. 8, the resin portion is provided such that the resin layer filled around the cutout portion covers all or part of both surfaces or one side of the substrate.

9 is an enlarged view showing a portion P of FIG. 8 in cross section. (Figs. 8 and 9 are examples in which resin parts are installed around the entire surface.)

As for the thickness t2 of the part which overlapped on this board | substrate, 0.2-5 mm is suitable for the width W on a board | substrate surface, except for the thickness of a board | substrate.

As described above, in the method of the present invention, the core is inserted into the cut-out hole in the substrate. However, since the cutting of the substrate is performed by pressing, the surface is rough. Therefore, although it is mentioned as the 2nd characteristic of this invention, moving a core which contacts this through this superb view without providing a resin part in the periphery, will severely damage a core by the contact of a core and a board | substrate.

In addition, due to the problem of the precision of the fures, there is a concern that the burr may be irregularly caused in the periphery, thereby significantly impairing the function of the product.

Therefore, in order to prevent these accidents, the board | substrate suitable for sheet metal pressing and metal mold | die with a very high precision is required.

However, when the method of the present invention is used, even if a substrate processed by a conventional method is used by providing a resin layer around the core, there is no risk of damage to the core and irregular burring.

Moreover, when there is a cutout of a board | substrate in contact with a functional part like this invention, since there is no support in that surface, it becomes easy to become unstable, but the resin layer of this invention has the effect which has an effect which supports a functional part to a board | substrate. do.

This effect is more remarkable than in the case where there is a resin part on the substrate surface as in the preferred shapes shown in FIGS. 8 and 9.

As described above, the method of the present invention is particularly useful when forming an undercut shape, which is useful when forming the undercut type by using the core without being limited to the undercut.

In the method of the present invention, as in the conventional outer insert molding, it is necessary to use a leveler for correcting the flipping of the substrate due to the press operation or to eliminate the occurrence of burrs, or to pre-treat the substrate such as cleaning the substrate. To attach the protruding pins onto the substrate (preferably near set pins), or to prevent deformation due to shrinkage of the functional part, the large functional part may be divided into small blocks by a slit, or a suitable balance for the opposite axis of the substrate. Various means, such as installing a branch or preheating a substrate, are effective and appropriately applicable means to obtain a stable product.

Claims (1)

Synthetic resin functional part made of an under-cart part when the functional part is molded on the substrate and molded by a molding core passing through a cut-out provided to the substrate. It is molded on a substrate using a structural mold, which is one of the components, and the substrate is made of synthetic resin on the substrate by forming a cavity between the cutout and the molding core so that the resin can be filled in the cavity. How to mold a functional unit.

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