JPH0677950B2 - Injection molding method - Google Patents

Description

The present invention relates to an injection molding method.

[Prior Art] Injection molding is often carried out not for the purpose of producing a product, but for the purpose of, for example, an experiment, for the purpose of producing a molded flat plate having a small amount of various shapes.

In the past, even in such a case, the inserts were manufactured according to the shape of the flat plate to be formed.

[Problems to be solved by the invention]

However, it is not preferable to manufacture the inserts in order to form a small amount of the flat plate because the work efficiency is lowered and the cost per molded product is high.

Therefore, an object of the present invention is to provide an injection molding method capable of forming a small amount of various shaped flat plates by a simple operation and greatly reducing the cost per sheet.

[Means for solving problems]

In order to achieve such an object, the present invention includes a fixed insert and a movable insert that are arranged to face each other, and at least one of the fixed insert and the movable insert is connected to an injection port. In an injection molding apparatus in which a recess is formed, a step of injecting a molding material from the injection port, a step of taking out a molding plate molded by the injection port, and cutting a part of the molding plate near the injection port into a desired shape. Then, the molded plate cut out by this is arranged in the recessed portion of the insert, and this molded plate has a function of the insert, and thereafter injection molding is performed.

[Action]

By doing this, it is not necessary to manufacture a new insert, and the first formed plate is processed into an appropriate shape and placed in the insert used when forming this processed plate. Since it has a nesting function, it will be a simple task.

In addition, the work forming plate having a nesting function can be processed into any desired shape according to the shape of the forming plate to be obtained, whereby a multi-shaped forming flat plate can be obtained.

Therefore, it is possible to greatly reduce the cost per sheet of the shaped flat plates of various shapes to be obtained even if the amount is small.

〔Example〕

An embodiment of the injection molding method according to the present invention will be described below with reference to the drawings.

First, FIG. 3 shows an injection molding apparatus applied to the present invention. In the figure, the injection molding apparatus includes a fixed insert 1 and a movable insert 2 that are arranged with respect to each other. The movable insert 2 is movable with respect to the fixed insert 1 so as to be spaced and abutted in the lateral direction α in the drawing. Further, a concave portion 3 is formed on the contact surface of the movable insert 2 with respect to the fixed insert 1, and the molding material passes through the injection passage 4 formed on the fixed insert 1 side in the concave portion 3. It is supposed to be ejected.

In the injection molding apparatus configured as described above, the surface of the movable insert 1 that contacts the fixed insert 1 is as shown in FIG. 1 (a). Here, in the vicinity of the concave portion 3, the injection port 5 is brought into contact with and communicated with the injection passage 3.
Are formed. FIG. 2 (a) is IIa- of FIG. 1 (a).
A sectional view at IIa is shown.

In order to carry out the present invention, first, as shown in FIG. 1 (b), a sheet-shaped magnet plate 6 is arranged on other side portions of the concave portion 3 except for the vicinity of the ejection port 5.
The movable insert 2 is made of a magnetic material. Therefore, the magnet plate 6 is attracted to the movable insert 2 in the illustrated state. As shown in FIG. 2 (b) which is a sectional view taken along line IIb-IIb of FIG. 1 (b), it is preferable to use a magnet plate 6 having a thickness smaller than the depth of the recessed portion 6. This magnet plate 6 forms a molding plate in a later step, and when the movable insert 2 is moved so as to be separated from the fixed insert 1, the magnet plate 6 is separated from the concave portion 3 of the movable insert 2 and is moved downward (toward the ground side). ) To prevent it from falling.

Next, the movable insert 2 is brought into the state shown in FIG. 3, and the injection molding material is injected from the injection passage 4. As a result, FIG. 1 (c)
As shown in FIG. 5, a molding plate 7 having the shape of the recess 3 is obtained. Then, the movable insert 2 is moved so as to be separated from the fixed insert 1, and the molding plate 7 is taken out from the movable insert 2. In this case, since the molding plate 7 is formed in a state in which the magnet plate 6 is fixed, it is in a state of being attracted to the movable insert 2, and can be easily removed by a force that opposes the attraction force. Can be peeled off.

Then, the molding plate 7 removed from the movable insert 2 is cut into a predetermined shape. As a cutting means, an electric saw, etc.
Other means may be used. In this case, as shown in FIG. 1 (b), it is important to cut a part of the molding plate near the injection port into a desired shape. Further, the cut end at the time of cutting can be provided with the taper portion 7A as shown in FIG.

Next, the molding plate 7 cut into a desired shape is placed in the recess 3 of the movable insert 2, as shown in FIG. 1 (e). The magnet plate 6 is fixed to the back surface of the molding plate 7, so that the molding plate 7 can be arranged in a state of being attracted to the concave portion 3. With such arrangement of the molding plate 7, as shown in FIG. 1 (e), the movable insert 2 is formed with a recessed portion 3'having a predetermined shape which is continuous with the injection port 5. That is, the molding plate 7 cut into a desired shape is used so as to have a nesting function.

Then, the movable insert 2 is brought into the state shown in FIG.
Injection molding material through. As a result, as shown in FIG. 1 (f), the concave portion 3'is filled with the material, and the molding plate 8 is formed. The material may be the same as or different from the material of the molding plate 7. Even if they are made of the same material, there is no concern that the molding plates 7 and 8 will stick to each other after molding because the molding plates 7 and 8 have a large temperature difference during molding.

After that, the movable insert 2 is separated from the fixed insert 1, the forming plates 7 and 8 are taken out from the movable insert 2, and the forming plate 8 is separated from the forming plate 7. In this case, since the boundary between the forming plates 7 and 8 is tapered as shown in FIG. 4, the separation can be easily performed.

As described above, according to the present embodiment, the molding plate 7 is cut into a desired shape, and the molding plate 7 is arranged in the concave portion 3 of the movable insert 2 so as to have a new insert function. You can Moreover, cutting the forming plate 7 into a desired shape can be performed by a simple operation, and the cost is not required.

For this reason, it is possible to form a small number of various shaped flat plates by a simple operation and greatly reducing the cost per one.

In the above-mentioned embodiment, the magnet plate 6 is simply formed into a sheet shape. However, as shown in FIG. 5, the notch 6A is formed so that the molding material can enter a part of the sheet shape. By providing it, it becomes possible to firmly fix the molded plate 7 and the magnet plate 6 to each other. That is, FIG. 5 is a view showing the back surface of the molding plate 7 shown in FIG. 1 (d), and the cutout portion 6A is shown in an enlarged view of the circular portion.

The magnet plate 6 described above is a fixed insert 1 as an injection molding device.
It is applied when the movable insert 2 and the movable insert 2 are arranged on the right and left. Therefore, the fixed insert 1 and the movable insert 2
Needless to say, it does not have to be applied to the case in which and are arranged in the vertical direction and the concave portion 3 is formed on the lower nesting side.

〔The invention's effect〕

As is clear from the above description, according to the injection molding method of the present invention, it is possible to form a small amount of various shaped flat plates by a simple operation and greatly reducing the cost per sheet. it can.

[Brief description of drawings]

1 (a) to (g) and 2 (a) to (c).
Is a configuration diagram showing an embodiment of an injection molding method according to the present invention,
FIG. 3 is a block diagram showing an embodiment of an injection molding apparatus to which the present invention is applied, and FIGS. 4 and 5 are explanatory views showing other embodiments of the injection molding method according to the present invention. 1 ... Fixed insert, 2 ... Movable insert, 3,3 '... Recessed part, 5 ... Injection port, 6 ... Magnet plate, 7,8 ... Molded plate.

Claims (1)

[Claims] 1. An injection molding method, comprising: a fixed insert and a movable insert, which are arranged to face each other, wherein at least one of the fixed insert and the movable insert is provided with a recessed portion continuous with an injection port. In the apparatus, a step of injecting a molding material from the injection port, a step of taking out a molding plate molded by this, cutting a part of the molding plate in the vicinity of the injection port into a desired shape, and a molding plate cut by this Is placed in the recessed portion of the insert, the molding plate is made to have the function of the insert, and then injection molding is performed.