KR101170044B1 - Injection mold having structure for treating inner undercut with circle shape and method for ejecting injection molded product thereof - Google Patents

Abstract

PURPOSE: An injection mold having a structure of treating an inner circular undercut and a molded article ejection method are provided to reduce a working time without an additional process because a plurality of molds for an undercut is not manufactured. CONSTITUTION: An injection mold having a structure of treating an inner circular undercut comprises a cavity plate(10), a core plate(20), an eject plate(30), an insert core(50), and a plurality of lift cores(60). The cavity plate comprises a cavity(11) inside. The cavity plate forms an injection mold having an under cut. The core plate closely or separately moves from the cavity plate. The eject plate moves up and down in the lower part of the core plate. The insert core is installed inside the core plate, and the cross section of the insert core is gradually reduced. A plurality of the lift cores is slid along the guide surface(21) of the core plate. The upper ends of the lift cores are extended toward the injection mold. The lower ends of the lift cores are inclined to be fixed to the eject plate.

Description

INJECTION MOLD HAVING STRUCTURE FOR TREATING INNER UNDERCUT WITH CIRCLE SHAPE AND METHOD FOR EJECTING INJECTION MOLDED PRODUCT THEREOF}

The present invention relates to an injection mold and an injection method for taking out an injection mold, and more particularly, to an injection mold and an injection method for taking out an injection mold having a structure for processing a circular undercut formed inside the cylindrical product.

In general, the injection mold is injected into a cavity provided between the stationary plate and the movable plate with a high temperature liquid resin and cooled to form a product, and then the movable plate is moved to open the mold. It refers to a metal frame from which a molded product can be obtained from the cavity.

At this time, when there is no undercut inside the injection molding, it is possible to take out by simple reciprocating motion using a blowout plate installed under the movable die, but the injection molding of a cylindrical product such as a lid has a thread undercut on the inside of the movable die. There is a problem that the ejection of the injection molding is possible only by moving inclined in the reciprocating direction or installing a special structure.

In this regard, in order to process the thread-shaped undercut formed in the inner side of the cylindrical product conventionally formed a thread on the tip of the core having a diameter corresponding to the inner diameter of the product by rotating the inner undercut of the rotating system configured to rotate the core when taking out the product Treatment methods have been used.

However, since the conventional drawing method uses a disc-shaped power member to rotate the core, the power transmission member elements assembled therein take up a lot of space in the mold, and thus, the volume of the mold is increased. Handling, assembly, installation and transport is complicated, there is a problem that the cost required for the mold production increases.

In addition, at least two stages of operation must be performed for ejection of the ejection, so that the number of processes increases so that the total cycle time for the production of the extrudate increases, and when there is a non-thread undercut inside the ejection, the rotation method There was a problem that cannot be taken out.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can easily take out an injection molded product having a circular undercut formed inside a cylindrical product, and does not need to perform an additional complicated driving step on the mold. An object of the present invention is to provide an injection mold and an ejection ejection method.

In order to solve the above problems, the present invention is an injection mold having a structure for processing the inner undercut of the injection molding machine is equipped with a cavity, the cavity plate for forming an injection molding having an inner undercut in the cavity; A core plate having a guide surface formed therein and operating and approaching the cavity plate with respect to the cavity plate; An eject plate operating up and down at the lower side of the core plate; An insert core installed inside the core plate and configured to have a cross-sectional area that decreases toward an upper side thereof, and having a four-axis surface, the four-axis surface having different angles for each of the two opposite shaft surfaces; And a plurality of lift cores slid through the guide surface, the upper end of which extends toward the injection molding, and the lower end of which is inclined to be fixed to the eject plate. Provided is an injection mold having an inner circular undercut treatment structure, characterized in that the first lift core and the second lift core are installed so as to face each other at different angles.

At this time, the eject plate is made of two layers of the upper and lower, it is characterized in that the lower end of the lift core is coupled to the upper eject plate.

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In addition, the first lift core is disposed between the second lift cores, and the second lift core is also moved toward the center as the first lift core is moved toward the center during the lift operation of the lift core. By doing so, there is also a feature in processing the inner undercut.

In addition, the present invention is a method for taking out the injection by the injection mold having a structure that is mounted on the injection molding machine to process the inner undercut of the injection, using a piston cylinder to move the core plate downward from the cavity plate fixed to the injection machine Exposing the injection molded product to the outside; Operating a mold cylinder to lift the eject plate spaced apart from the core plate; As the eject plate is lifted up, a plurality of lift cores having a lower end fixed to the eject plate and inclined upwards are formed in the core plate and have a cross-sectional area that becomes smaller toward the upper side, and is opposed to two axis surfaces. A step of actuating along the four axes of the insert cores having the four axes having different angles each time; And as the plurality of lift cores are lifted up, an upper portion of each lift core is gathered toward the center so that the cross-sectional area of the core unit is reduced, whereby the plurality of lift cores are separated from the injection molding to process the inner circular undercut of the injection molding. The lift core is disposed so that the first lift core and the second lift core are opposed to each other at two different angles along the four axis surfaces of the insert core, between the second lift cores. As the first lift core installed is moved toward the center first, the second lift core is also moved toward the center to facilitate the ejection of the injection molding. to provide.

According to the present invention, it is possible to easily take out the injection molding having a circular undercut formed on the inside of the cylindrical product, there is no need for a separate driving device for the rotation of the core, eliminating the problem of shape deletion occurring in the general undercut structure There is a significant reduction in the original design constraints.

In addition, it is not necessary to manufacture a plurality of molds for solving the undercut, and there is no need to perform additional process steps such as a process of forming and combining two injection moldings (fusion process), so that no process defects occur due to additional processes. Along with the reduction of working time, there is the effect of productivity improvement and cost reduction.

1 is a view showing a part of the injection mold having an inner circular undercut treatment structure before taking out according to an embodiment of the present invention.
Figure 2 is a view showing a part of the injection mold having an inner circular undercut treatment structure after taking out according to an embodiment of the present invention.
3 is a plan view of a lift core according to an embodiment of the present invention, (a) before drawing, (b) during drawing, and (c) after drawing.
4 is a perspective view of a lift core according to an embodiment of the present invention, (a) is a drawing before taking out, (b) is a drawing during taking out, (c) is a drawing after taking out;

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is described in detail with reference to drawings, centering on an Example.

The injection mold and the ejection ejection method having an inner circular undercut treatment structure according to the present invention can easily eject the ejection having a circular undercut formed inside the cylindrical product, there is no need for a separate driving device for rotation of the core, Accordingly, the manufacturing cost is reduced, and the overall working time for the production of the injection molded product is greatly improved.

The present invention is largely fixed by the injection molding machine to be fixed to the injection molding machine, the movable side template is installed on the lower side of the fixed side template to move up and down and the opening of the movable side template to process the inner undercut of the injection molding It consists of a core unit (core unit).

At this time, as shown in Figure 1, the fixed side template is a cavity (cavity) plate (10), having a cavity (11) on the inside, a high temperature liquid resin is injected into the cavity (11) inside The injection molding 100 having the undercut is molded.

In addition, the movable side template is disposed below the fixed side template, and a hydraulic or pneumatic cylinder is embedded therein, a core plate 20, an eject plate 30, and a fixed plate , 40).

The core plate 20 is formed with a guide surface 21 for guiding the up and down movement of the lift core 60 therein, and the hydraulic or pneumatic cylinder is built into the core plate 20 to be described later. The injection-molding material 100 is easily taken out by moving the plate 30 up and down.

The core plate 20 is approached and spaced apart from the cavity plate 10 integrally with the eject plate 30 and the fixed plate 40 by a piston cylinder installed under the fixed plate 40, and When spaced apart from the cavity plate 10, the outside of the injection molding 100 is separated from the cavity 11 to be exposed to the outside.

The eject plate 30 is spaced apart from the core plate 20, and consists of two layers of an upper eject plate 31 and a lower eject plate 32, and a lower end of the lift core 60 is an upper eject plate ( 31 is movable in the horizontal direction while being coupled to the pin, and moves up and down from the lower side of the core plate 20 by a cylinder embedded in the movable side template, thereby processing the inner undercut of the injection molding 100 Make it possible.

The fixing plate 40 is disposed on the lower side of the eject plate 30 to support it and to fix the injection mold to the injection machine.

The core unit includes an insert core 50 disposed inside the core plate 20 and a lift core 60 that is a deformation core.

In addition, as shown in FIG. 4, the insert core 50 is formed in the core plate 20 and has a shape in which the cross-sectional area thereof becomes smaller toward the upper side, and has an inclined outer surface of the four shaft surface 51. The four axis surfaces 51 are formed to face each other by two axis surfaces, and any one of the two axis surfaces facing each other is manufactured to have a different inclination angle from the other two axis surfaces facing each other, and a deformation core outside the four axis surfaces 51. The in lift core 60 is disposed.

The plurality of lift cores 60 are formed to form the appearance of the core unit, the upper end is formed to extend toward the injection molding 100, the lower end is fixed to the eject plate 30 is formed to be inclined, the guide surface ( 21 and the slide core can be slid along the four axis surfaces 51 of the insert core 50.

In this case, as shown in FIG. 3, the lift core 60 includes two first lift cores 61 and two second lift cores 62 along the four axial surfaces 51 of the insert core 50, respectively. Exposed to face each other with different angles, which is not demolded smoothly even if the lift core 60 is moved upward when the first lift core 61 and the second lift core 62 have the same angle. Therefore, since the first lift core 61 and the second lift core 62 are manufactured to have different angles, demolding can be performed easily and smoothly.

That is, the first lift core 61 is disposed between the second lift cores 62, and the first lift core 61 first moves toward the center during the lifting operation of the lift core 60. Accordingly, the second lift core 62 is also moved toward the center to easily process the inner undercut.

On the other hand, in the injection molding method of the injection mold having an inner circular undercut treatment structure according to the present invention, as shown in Figure 2, the movable side is operated, the cavity plate 10 fixed to the core plate 20 to the injection machine A spaced apart operation from below to expose the injection molding 100 to the outside.

Then, the mold opening operation is started and during the opening operation, the eject plate 30 is raised by operating the cylinder built in the injection mold by pneumatic or hydraulic pressure.

As the eject plate 30 is raised, a plurality of lift cores 60 fixed to the eject plate 30 are raised along the guide surface 21 provided in the core plate 20. Accordingly, the upper portion of each lift core 60 is gathered toward the center to reduce the cross-sectional area of the core unit, whereby a plurality of lift cores 60 are separated from the injection molding to process the inner undercut of the injection molding.

Here, in the lift operation of the lift core 60, as the first lift core 61 having a small size disposed between the second lift cores 62 first moves toward the center, the second lift core ( 62) can also be moved toward the center to facilitate the demoulding of the product and take out smoothly.

As a result, the injection mold having the inner circular undercut treatment structure according to the present invention can easily take out the injection molded product having the circular undercut formed on the inner side of the cylindrical product, and there is no need for a separate driving device for the rotation of the core, and the deformation core By taking the injection at the same time as the operation, there is no need to perform an additional complicated driving step, and the overall working time for the production of the injection is reduced, which greatly improves the productivity.

In the present invention, the above embodiment is only one example, and the present invention is not limited thereto. Anything that has substantially the same configuration as the technical idea described in the claims of the present invention and achieves the same effect is included in the technical scope of the present invention.

10.cavity plate 11.cavity
20. Core plate 21. Guide face
30. Eject Plate 31. Upper Eject Plate
32. Lower eject plate 33. Pin
40. Retaining Plate 50. Insert Core
51. Axial surface 60. Lift core
61. First lift core 62. Second lift core
100. Injection

Claims (5)

In the injection mold having a structure mounted on the injection machine to process the inner undercut of the injection molding,
A cavity plate having a cavity therein and forming an injection molded product having an inner undercut in the cavity;
A core plate having a guide surface formed therein and operating and approaching the cavity plate with respect to the cavity plate;
An eject plate operating up and down at the lower side of the core plate;
An insert core installed inside the core plate and configured to have a cross-sectional area that decreases toward an upper side thereof, and having a four-axis surface, the four-axis surface having different angles for each of the two opposite shaft surfaces; And
And a plurality of lift cores slid through the guide surface, the top of which extends toward the injection molding, and the bottom of which is inclined to be fixed to the eject plate.
The lift core is an injection mold having an inner circular undercut treatment structure, wherein the first lift core and the second lift core are installed to face each other at two different angles along the four axis surfaces of the insert core.
The method of claim 1,
The eject plate is composed of two layers of upper and lower, the injection mold having an inner circular undercut treatment structure is coupled to the lower end of the lift core to the upper eject plate.
delete The method of claim 1,
The first lift core is disposed between the second lift cores, and during the lift operation of the lift cores, the second lift cores are also moved toward the center as the first lift core is moved toward the center, thereby making an inner undercut. Injection mold having an inner circular undercut treatment structure, characterized in that for processing.
In the method of taking out the injection-molded product by the injection mold mounted on the injection molding machine having a structure for processing the inner undercut of the injection molding,
Exposing the injection molding to the outside by operating the core plate spaced downward from the cavity plate fixed to the injection molding machine using a piston cylinder;
Operating a mold cylinder to lift the eject plate spaced apart from the core plate;
As the eject plate is lifted up, a plurality of lift cores having a lower end fixed to the eject plate and inclined upwards are formed in the core plate and have a cross-sectional area that becomes smaller toward the upper side, and is opposed to two axis surfaces. A step of actuating along the four axes of the insert cores having the four axes having different angles each time; And
As the plurality of lift cores are lifted up, an upper portion of each lift core is gathered toward the center so that the cross-sectional area of the core unit is reduced, whereby the plurality of lift cores are separated from the injection molding to process the inner circular undercut of the injection molding. Including;
The lift core is disposed such that the first lift core and the second lift core face each other at two different angles along the four axis surfaces of the insert core, so that the first lift core disposed between the second lift cores The first ejection method of the injection mold having an inner circular undercut treatment structure, characterized in that the second lift core is also moved toward the center as the first move toward the center to facilitate the ejection of the injection.

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