JPH09155883A - Mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a plurality of molded products due to the difference of the presence of a hole without interrupting molding such as injection molding by making the leading end surface of the core provided to a template movable between a position becoming flush with a core surface and a position protruding from the core surface. SOLUTION: A mold is closed and a molten resin is injected into a cavity 11 from a molding machine through a sprue 6. A core 3 protrudes into the cavity 11 and, since the leading end thereof is set to the position almost coming into contact with the mold surface of an opposed template 1, the molten resin is not injected into this part and the resin free part becomes the hole part of a molded product. The injected resin is cooled and cured by the cooling fluid flowing through the fluid passages provided to a fixed template 1 and a movable template 2. Thereafter, the movable template 2 is allowed to retreat along with the molded product and an ejector pin 9 is allowed to protrude to take out the molded product. Hereinafter, this procedure is repeated to mold the molded product having a hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for synthetic resin, and more particularly to a molding die capable of forming holes in a molded product as required.

[0002]

2. Description of the Related Art Among molded products formed by injection molding or the like, it is desired to mold a plurality of molded products having the same shape, one having holes and one having no holes. Sometimes. For example, as in the case of molded products A and B shown in FIGS. 3 (a) and 3 (b), the two have the same basic shape except that they have a hole C, but they are the same in injection molding or the like. In the case of molding by, the two molding dies suitable for the respective molded products are prepared and molded, or the molding dies in which the portion of the molding die corresponding to the portion of the hole C is nested. Was prepared, the nest was exchanged, and molding was performed.

[0003]

However, in the case of using two molding dies, one extra molding die is required, which increases the manufacturing cost of the molding die. Further, it is troublesome to remove or attach the molding die from the molding machine at the time of molding. In addition, even when using a mold for replacing the insert, the inserter is replaced by opening the mold once to stop the forming machine and replacing the insert. I had to do it.

It is an object of the present invention to provide a molding die capable of molding a plurality of molded products depending on the presence or absence of holes without interrupting molding such as injection molding.

[0005]

In order to achieve the above object, in the molding die of the present invention, a core provided on a mold plate is provided with a nest, and the tip end surface of the nest is flush with the core surface. It is characterized in that it can be moved to a position where it becomes one and a position where it projects from the core surface.

The molding die of the present invention is preferably used as a molding die used in injection molding, compression molding, Tohsan Suffer molding, etc., and the nest is moved automatically by a fluid pressure cylinder. Be seen.

Further, in the present invention, when the tip surface of the insert is at a position projecting from the core surface, the insert projects into the cavity formed when the molding die is closed,
The tip is positioned so as to almost contact the mold surface of the facing mold plate. Since the mold surface of the template may be damaged if it is projected to the position where it directly contacts, the mold surface of the template is 3/100 to 5
It is preferable to have a gap of about / 100 mm. In the gap of this degree, the through hole is formed in the molded product without the molten resin entering. In this way, holes are formed in the molded product by nesting.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a molding die according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a molding die of the present invention used for injection molding a molded product having holes.
(A) is sectional drawing which shows the state before closing a mold, (b) is sectional drawing which shows the state when closing a mold.

In FIG. 1, 1 is a fixed-side mold plate, 2 is a movable-side mold plate, 3 is a nest, 4 is a fixed-side mounting plate, 5 is a movable-side mounting plate, 6 is a sprue, 7 is a guide pin, and 8 is Spacer blocks, 9 are ejector pins, and 10 are ejector plates. The sprue lock pin is not shown.

The insert 3 is slidably inserted in the core 21 of the movable side mold plate 2 and is provided with a hole in the molded product.
If there is no hole, its position can be changed.

In FIG. 1, the insert 3 is placed at a position projecting from the upper surface of the core 21 of the movable side mold plate 2. That is, the base of the insert 3 is housed in the fluid pressure cylinder 31, and the insert 3 is advanced to a predetermined position by the fluid pressure from the fluid passages 32, 32 and is placed at the position where the tip of the insert 3 projects. In this way, the molding die is in a state where holes are formed in the molded product.

The protruding portion of the insert 3 protrudes into the cavity formed when the molding die is closed, and the tip thereof is positioned so as to be substantially in contact with the mold surface of the facing mold plate 1 (see FIG. 1 ( See b)).

FIG. 1 (a) shows a state immediately after the mold is opened and a molded product (not shown) is pushed out by the ejector pin 9, and when the mold is clamped, the ejector pin 9 is retracted and its tip end surface is made into a core. It is flush with the surface of No. 21. Of course, this molding die is used by being attached to a molding machine (injection molding machine). The molding die is mounted by mounting the fixed side mounting plate 4 and the movable side mounting plate 5 at predetermined positions of the molding machine.

Next, the procedure for molding a molded product having holes by injection molding using the molding die in the state shown in FIG. 1 will be described. First, as shown in FIG. 1B, a molding die (injection molding die) is closed, and a molten resin is injected into a cavity 11 through a sprue 6 from a molding machine (injection molding machine) not shown. .

As described above, the nest 3 has the cavity 1
Since it is projected into the inside of the mold 1 and the tip of the mold is in contact with the mold surface of the facing mold plate 1, the molten resin is not injected into this part and becomes a hole of the molded product. The injected resin,
It is cooled and hardened by the cooling fluid flowing through the fluid passages (not shown) provided in the fixed-side mold plate 1 and the movable-side mold plate 2.

After that, the movable template 2 is retracted together with the molded product (not shown) and the ejector pins 9 are projected to take out the molded product. Hereinafter, this procedure is repeated to mold a molded product having holes.

Although only one nest 3 is shown in the drawing, a plurality of nests can be similarly set. For example, if the number is two, a molded product having two holes as shown in FIG. 3B can be obtained.

2A and 2B are cross-sectional views of a molded product having no holes, in which FIG. 2A is a cross-sectional view showing a state before the mold is closed, and FIG. It is sectional drawing which shows the state when it is made.

In FIG. 2, the insert 3 is connected to the fluid passage 32,
With the fluid pressure from 32, it is retracted from the position shown in FIG.
The description is omitted because it is the same as that of FIG. 1 except that the front end surface thereof is flush with the core 21. The molding procedure is also the same as in FIG. 1, but since the insert 3 is flush with the surface of the core 21 and does not project into the cavity 11, there is no hole as shown in FIG. The product is molded.

[0021]

As described above, in the molding die of the present invention, since the tip end surface of the insert is movable to the position flush with the core surface and the position projecting from the core surface, It is possible to easily change the position of the nest while the molding die is attached to the molding or the like, and it is possible to mold both a molded product with holes and a molded product without holes without stopping the formation for a long time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a molding die of the present invention used for injection-molding a molded product having holes, (a) is a cross-sectional view showing a state before the mold is closed, and (b) is a mold. It is sectional drawing which shows the state when closing.

FIG. 2 is a cross-sectional view showing a state in which the tip surface of the insert is flush with the core surface in the molding die of FIG.
(A) is a sectional view showing a state before the mold is closed, and (B) is a sectional view showing a state when the mold is closed.

FIG. 3 is a perspective view showing an example of a molded product, (a) is a perspective view of a molded product without holes, and (b) is a perspective view of a molded product with holes.

[Explanation of symbols]

 1 Fixed-side mold plate 2 Movable-side mold plate 21 Core 3 Nesting 4 Fixed-side mounting plate 5 Movable-side mounting plate 6 Sprue 7 Guide pin 9 Ejector pin 11 Cavity

Claims (1)

[Claims] 1. A core provided on a template is provided with a nest, and the tip end surface of the nest is movable to a position flush with the core surface and a position protruding from the core surface. Mold for molding.