KR100550532B1 - Transformation core type injection molding die and molding method for the same - Google Patents

Abstract

The present invention relates to an injection mold of a modified core method and an injection method thereof, which is easy to take out an undercut during injection molding and has a simple structure.

Injection mold of the modified core method of the present invention is a fixed core, a movable core detachably installed on the fixed core and forming a hollow portion of the product shape with the fixed core, and installed between the movable core and the fixed core A deformable core forming an undercut portion of the deformable part, a tip pin rotatably coupled to one side of the deformable core to move the deformable core, and a protrusion formed on one side of the movable core to move to a guide groove formed in the deformable core It can be inserted and configured to include a guide pin for guiding the movement of the deformation core so that the undercut portion is taken out by the action of the mil pin, the direction of operation of the mil pin is changed by the guide groove and the guide pin to the undercut Since it moves in the ejecting direction, the undercut is removed from the deformation core even if a separate drive device is not installed. This is possible, there is an advantage consisting of a simple structure for connecting the deformation core to the tip of the Milpin.

Injection molding, fixed core, movable core, deformation core, mil pin, guide groove, guide pin

Description

Transformation core type injection molding die and molding method for the same

1 is an internal configuration diagram showing the main part of the injection mold according to the prior art,

Figure 2 is an internal configuration showing the main part of the injection mold according to the present invention,

Figure 3a, 3b, 3c is an operating state diagram showing the shape in which the injection mold is opened according to the present invention,

4 is a perspective view showing a modified core of an injection mold according to the present invention.

<Explanation of symbols on main parts of the drawings>

52: fixed core 54: movable core

56: product 58: modified core

60: Milpin 62: Locking Block

64: guide groove 66: guide pin

68: insertion groove A, C: undercut

B, D: Parting line E: Milpin operation direction

F: Undercut ejection direction G: Safety distance

The present invention relates to an injection mold of a modified core method and an injection method thereof, and more particularly to an injection mold of a modified core method that is easy to take out an undercut during injection molding and has a simple structure.

1 is an internal configuration diagram showing an example of an injection mold according to the prior art.

The injection mold of the sliding core method according to the prior art, as shown in Figure 1, the fixing core (2) forming the upper portion of the mold, and in the vertical direction so as to be in close contact or separated on the lower surface of the fixing core (2) A movable core 4 movably installed and forming a lower part of the mold, and a sliding core disposed between the movable core 4 and the fixed core 2 to form an undercut portion A of the product 6 ( 8), a locking block 10 fixed to the fixed core 2 to set the position of the sliding core 8, and a relative movement opposite to the moving direction of the movable core 4, the product 6 The inclined pin 12 is installed to be inclined so as to penetrate the fixed core 2 and the sliding core 8 to guide the movement of the sliding core 8 when the movable core 4 moves. 14).

Here, the fixed core (2) and the movable core (4) are in close contact with each other to form a parting line (B), the inner side to form a hollow portion of the product (6) shape.

One side of the fixed core 2 is inclined to form a first pin hole 16 is formed stepped so that the inclined pin 14 is inserted through the head portion 14a is caught, one side of the sliding core 8 In the second pin hole 18 through which the inclined pin 14 penetrating the fixing core 2 is inserted is inclined.

Therefore, the inclined pin 14 is inserted into the first pin hole 16 and the second pin hole 18 so as to be inclined at a predetermined angle inside the mold, and the tip is provided with the second pin hole 18 at a predetermined length. Protruding from) is disposed inside the core groove (4a) formed in the movable core (4).

On the other hand, when the movable core 4 is moved downward, the sliding core 8 is lowered inclined at a predetermined angle along the inclined pin 14, in which the undercut (A) from the sliding core (8) It is taken out.

Looking at the operation of the injection mold of the sliding core method according to the prior art configured as described above are as follows.

First, after injection molding the molten plastic material formed in the hollow core formed by the fixed core 2 and the movable core 4 and cooling the finished product 6, the movable core 4 is moved downward. Open the mold.

At this time, as the movable core 4 is lowered, the sliding core 8 and the product 6 are also lowered, and the sliding core 8 is lowered obliquely along the inclined pin 14 to undercut the product 6. A) deviates from the site.

When the undercut A is taken out from the sliding core 8 as described above, the mill pin 12 is operated upward, and the product 6 is taken out from the movable core 4.

However, the injection mold of the sliding core method according to the prior art, such as the inclined pin 14, the first pin hole 16, the second pin hole 18, the core groove 4a, etc. so that the undercut (A) can be taken out. There is a problem that the number of parts is increased, as well as the additional machining is increased, the cost is increased.

In addition, when the number of parts increases as described above, the structure of the mold becomes complicated, making fabrication difficult, and the interaction between the parts increases, causing the mold to fail.

The present invention was created in order to solve the above problems, an object of the present invention is easy to take out the undercut, the structure is simple, injection mold of a modified core method that can prevent breakage and failure of the mold during injection molding and The injection method is provided.

Injection mold of the modified core method of the present invention for realizing the above object is a fixed core, a movable core which is detachably installed on the fixed core and forms a hollow portion of the product shape with the fixed core, and the movable core and A deformation core installed between the fixed cores to form an undercut portion of the product, a tip pin rotatably coupled to one side of the deformation core and actuating the deformation core, and a protrusion formed on one side of the movable core to deform the deformation core. The guide pin is movably inserted into the guide groove formed in the core and comprises a guide pin for guiding the movement of the deformation core so that the undercut portion is taken out by the action of the mill pin.
In addition, the injection molding method of the injection mold according to the present invention is a product forming step in which the injection liquid is injected into the hollow portion formed by the fixed core and the movable core and the deformation core to form a product, and the movable core and the deformation core together with the product The movable core stripping step removed from the fixed core, and the mill pin is operated in the opposite direction to the stripping direction of the movable core so that the deformation core is moved between the operation direction of the pin and the undercut ejection direction along the guide pin of the movable core by the force of the mill pin. A step of moving the deformed core to be inclined and moving the deformed core more than a predetermined distance in the direction of operation of the mill pin to take out the product from the movable core; And an undercut takeout step in which the undercut portion of the product is withdrawn from the deformation core. The features.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 2 is an internal configuration showing the main part of the injection mold according to the present invention, Figures 3a, 3b, 3c is an operating state diagram showing the shape in which the injection mold according to the invention is opened, Figure 4 is in accordance with the present invention A modified core of an injection mold is shown in perspective view.

Injection mold of the modified core method according to the present invention, as shown in Figures 2 to 4, the fixed core 52 that forms the upper portion of the mold, and is movable to be in close contact with and separated from the lower surface of the fixed core 52 The movable core 54 is installed to form a lower portion of the mold, and the deformation core 58 is installed between the movable core 54 and the fixed core 52 to form an undercut (C) portion of the product 56. And, the lower end of the deformable core 58 is rotatably connected to the pin and the pin 60 to operate the deformable core 58 to take out the product and the undercut, and the upper end is fixed to the fixed core 52 The locking block 62 for setting the position of the deformable core 58 and protruded on one side of the movable core 54 is inserted into the guide groove 64 formed in the deformable core 58 and the deformable core 58 To change the operation direction of the mil pin 60 so that the undercut (C) portion can be withdrawn from And a guide pin 66.

Here, the fixed core 52 and the movable core 54 are in close contact with each other to form a parting line D, and a hollow part in the shape of a product 6 for injecting molten plastic material is formed therein.

In this movable core 54, a plurality of mil pins 60 for discharging the product 6 upward when the mold is opened are arranged to be movable upward and downward, and any one of the plural mil pins 60a and 60b. 60a is rotatably connected to the lower end of the deformable core 58 to operate the deformable core 58 when the movable core 54 moves.

That is, the mill pin 60 is lowered with the movable core 54 when the movable core 54 is lowered, but after the predetermined distance is lowered by the movable core 54, the upper side is separated by a separate operating device. It is either moved to or kept stopped. Accordingly, the milp pin 60 relatively moves the deformable core 58 and the product 56 opposite to the moving direction of the movable core 54.

In addition, the deformable core 58 has an inclined guide groove 64 in which the guide pin 66 is inserted at one side thereof, and an insertion groove 68 in which a tip of the mill pin 60a is rotatably inserted in a lower portion thereof. Is formed.

The guide pin 64 is inserted into the guide pin 66 so as to be movable, and the deformation pin 58 so that the deformation core 58 can be moved in the operating direction (E) of the mill pin and in the undercut ejection direction (F) at the same time. It is formed to be inclined in the undercut ejection direction (F) with respect to the operating direction (E) of.

That is, the guide grooves 64 and the guide pins 66 are formed by the mill pins 70 so that the undercut C portion of the product 56 can be taken out from the deformation cores 58. The moving direction is changed from the operation direction E of the mill pin to the ejection direction F of the undercut.

The guide groove 64 is formed to be inclined at a critical angle or more at which the distance f1 of the deformation core moved in the undercut ejection direction F becomes equal to the minimum distance f2 for the undercut C to be taken out.

In addition, when the movable core 54 is lowered to open the mold, the deformation core 58 is moved in the working direction E of the mill pin so that the product 56 can be taken out together with the mill pin 60b. The guide groove 64 is formed such that the length e1 of the mil pin in the operating direction E is longer than the minimum distance e2 for the product 56 to be taken out.

Therefore, the deformation core 58 also pushes the product 56 upward with the mil pin 60b in the process of taking out the undercut C, thereby simultaneously leaving the product 56 from the movable core 54. Will be performed.

Guide groove 64 formed as described above is to apply a safety distance (G) to prevent the damage and deformation that may occur if the operating distance of the mill pin (60) is wrong.

This safety distance (G) is formed in the lower direction of the guide groove 64 in the operating direction (E) of the pin, and is formed in a predetermined length to sufficiently compensate for the operating error of the pin (60).

On the other hand, the insertion groove 68 is formed in the lower portion of the deformation core 58 in the 'T' shape is formed long in the undercut ejection direction (F), the tip of the mill pin (60a) is rotatably inserted. .

A locking jaw 70 is formed along the outer circumference of the tip of the mill pin 60a to be engaged in the operation direction E of the mill pin in the insertion groove 68, and to slide in the undercut ejection direction F. Is inserted.

The locking block 62 prevents the deformation core 58 from being pushed during the injection molding, and when the mold is opened, the locking block 62 escapes from the deformation core 58 to move the deformation core 58 in the undercut ejection direction (F). To help.

In particular, unlike the prior art, the deformable core 58 and the mill pin 60a may be installed on both the outer side and the inner side of the hollow part of the product shape formed by the fixed core 52 and the movable core 54, and the outer side of the hollow part. When installed in the outer undercut of the product can be molded, when installed inside the hollow portion the inner undercut of the product can be molded.

Looking at the bent axis method by the injection mold of the modified core method according to the present invention configured as described above are as follows.

First, when the molten plastic material is injected into the hollow formed by the fixed core 52 and the movable core 54 and then cooled, and the product 56 is molded, the movable core 54 is removed from the fixed core 52. The movable core 54 is moved downward so that the mold is opened by being removed.

At this time, the product 56, the deformation core 58, the mill pin 60, etc. are lowered downward with the movable core 54, as shown in Figure 3a, the locking block 62 is the deformation core Departure from (58).

When the movable core 54 is lowered by a predetermined distance or more, as shown in FIG. 3B, the plurality of mil pins 60a and 60b operate upwards to release the product 56 from the movable core 54. At the same time, the deformation core 58 is moved upward.

That is, the deformation core 58 is raised in the operation direction E of the mill pin by the operation of the mill pin 60a, and at the same time in the ejection direction F of the undercut by the guide pin 66 and the guide groove 64. Is moved.

The deformable core 58 serves to take out the product 56 together with the mil pin 60 until it is completely separated from the undercut (C).

Therefore, the deformation core 58 is sufficiently moved in the undercut takeout direction F and the product takeout direction E by the guide pin 66 and the guide groove 64 to move the undercut C and the product 56. Will be taken out.

On the other hand, as shown in Figure 3c, even after the undercut (C) and the product 56 is completely taken out, if the deformation core 58 is moved by the mill pin 60, the guide pin 66 is a guide The safety distance (G) of the groove 64 is moved to the portion to which the operation error of the mil pin 60 is absorbed.

When the product 56 is completely taken out from the mold as described above, the mill pin 60 is returned to its original position, and the movable core 54 is raised again to be in close contact with the fixed core 52.

At this time, the mill pin 60 is moved to the initial position by a separate operating device to transfer the action force to the deformation core 58, the deformation core 58 to the initial position by the action of the mill pin (60a). Is regressed.

Therefore, since the mold is in an initial state capable of injection molding again, the injection molding operation is repeated.

The injection mold and the injection method of the modified core method according to the present invention configured as described above is changed by the guide groove and the guide pin of the mill pin, so that the deformation core is moved in the direction in which the undercut is taken out, so that a separate driving device Even if it is not installed, it is possible to take out the undercut from the deformation core, there is an advantage consisting of a simple structure that connects the deformation core to the tip of the Milpin.

In addition, the deformation core has the advantage of improving the releasability of the product by acting to remove the product from the movable core with the milpin while moving in the direction in which the undercut is taken out.

In addition, the guide groove is formed to have a clearance in the take-out direction and the product take-out direction to ensure the take-out of the undercut and removal of the product, and a separate safety distance is further formed at the bottom of the guide to the There is an advantage that the damage of the mold due to the operation error is prevented.

In addition, unlike the prior art, the deformation core and the pin can be installed both inside and outside the hollow portion of the product shape, and thus can be applied to not only the outer undercut of the product but also the inner undercut, which is advantageous in the injection molding of various products.

In addition, since the injection mold configured as described above has a simple structure in which the number of parts and the interoperability between parts is reduced, it is easy to manufacture and thus the manufacturing cost is reduced, and the durability is improved, so that mold management and parts maintenance are unnecessary. have.

Claims (8)

A fixed core; A movable core detachably mounted to the fixed core and forming a hollow portion of a product shape together with the fixed core; A deformable core installed between the movable core and the fixed core and forming an undercut portion of the product; A tip pin coupled to one side of the deformable core to be rotatable and operating the deformable core; And a guide pin formed to protrude on one side of the movable core so as to be movably inserted into the guide groove formed in the deformation core and to guide the movement of the deformation core so that the undercut portion is taken out by the action of the mill pin. Injection mold of modified core method. The method of claim 1, The guide groove is a modified core type injection mold, characterized in that formed in the inclined in the undercut ejection direction with respect to the operation direction of the milpin so that the deformation core is moved in the direction of operation of the mill pin and at the same time in the undercut ejection direction. The method of claim 2, The guide groove is a modified core injection mold, characterized in that formed in the inclined more than the critical angle that the distance moved in the undercut ejection direction is equal to the minimum distance for taking out the undercut. The method of claim 3, wherein The guide groove is a modified core type injection mold, characterized in that the deformation core is formed longer than the minimum distance for the product to be taken out in the direction of operation of the mill pin so that the product withdraws from the movable core with the pin. The method of claim 4, wherein The guide groove is a modified core type injection mold, characterized in that to apply an extra safety distance in the direction of operation of the mill pin to compensate for the error of the working distance of the pin. The method according to any one of claims 1 to 5, An insertion groove is formed in one side of the deformable core in an undercut discharging direction, and an end of the mill pin is inserted into the insertion groove so as to be movable in an undercut dispensing direction, and the locking jaw is caught in the operation direction of the mill pin in the insertion groove. Injection mold of the modified core method, characterized in that formed. The method according to any one of claims 1 to 5, The deformation core and the mold pin is a modified core injection mold, characterized in that installed on at least one side of the inside and the outside of the hollow portion of the movable core to selectively take out the inner undercut and the outer undercut of the product. A product forming step of injecting and cooling the injection liquid into the hollow formed by the fixed core, the movable core, and the deformation core to form a product; A movable core removing step of removing the movable core and the deformation core from the fixed core together with the product; A deforming core moving step in which a mil pin is operated opposite to a detachment direction of the movable core so that the deformable core is inclinedly moved between the operative direction of the mil pin and the undercut ejection direction by the action force of the mil pin; A product taking-out step in which the deformation core is moved over a predetermined distance in the operation direction of the mill pin to take out products from the movable core; And an undercut taking-out step of moving the deformable core in the undercut taking out direction by a predetermined distance and taking out an undercut portion of the product from the deforming core.

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