KR20220069601A - Separable Core Type Die Casting Mold And Die Casting Method Using Thereof - Google Patents

Abstract

The present invention comprises: a fixed core; a moving core which includes an ejector pin and moves back and forth to form a cavity of a shape of a product by being closely attached to the fixed core; a slide core which is closely attached to the fixed core and the moving core, respectively, and which moves back and forth to form a cavity of an undercut shape of the product; and a shape core of which one end is fixed to the slide core and the other end is closely attached to the moving core. A shape core removal type die casting mold can mold an inner undercut part without separate machining.

Description

Separable Core Type Die Casting Mold And Die Casting Method Using Thereof

The present invention relates to a shape core removable die casting mold and a die casting method using the same, and more particularly, to a shape core removable die casting mold capable of realizing an inner undercut shape, and a die casting method using the same.

In general, die casting is to manufacture the same casting molded product as the mold by injecting molten metal into a steel mold machined to match the shape to be molded.

Such die casting is widely used in various fields because it has high dimensional accuracy and can easily manufacture precision products with complex shapes, and in particular, is commonly used in the production of automobile parts.

However, when molding relatively complex products in such die casting, the mold core's withdrawal direction. That is, the undercut shape, which is a shape formed in the reverse direction to the backward direction, cannot be implemented.

On the other hand, Figure 1 is a side cross-sectional view showing an example of a product including an inner undercut.

Referring to FIG. 1 , the product (P) is a differential carrier product (P) among automobile parts. As the part IUC cannot be molded, the inner undercut part ICU is formed through machining such as cutting after separating the product from the mold.

Therefore, when a product including an inner undercut part is produced by die casting, there is a problem in that the manufacturing time due to the molding of the inner undercut part increases, as well as the bubble isolation and the occurrence rate of the shrinkage hole in the inner undercut part are significantly high.

Meanwhile, Korean Patent Laid-Open Publication No. 10-2015-0135563 discloses an injection mold having an undercut molding structure using an undercut molding ring.

In this conventional injection mold, the undercut part is molded by assembling a mold in a state in which the molding ring is coupled to the undercut part, and injecting the molding liquid to prevent injection of the molding liquid into the position of the molding ring.

However, this conventional injection mold is for molding a product made of synthetic resin material, not aluminum, and in the case of aluminum die casting, aluminum is melted at a temperature of at least 650 ° C. Since this melted and the undercut part is not formed, it cannot be applied to aluminum die casting.

Republic of Korea Patent Publication No. 10-2015-0135563 (published on December 3, 2015)

It is an object of the present invention to solve the above problems, and to provide a shape core removable die casting mold capable of forming an inner undercut without performing separate machining in high temperature and high pressure aluminum die casting, and a die casting method using the same will do

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the embodiments of the present invention.

It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

In order to solve the above problems, the shape core removable die casting mold according to the present invention has a fixed core, a movable core that is in close contact with the fixed core and moves forward and backward to form a product-shaped cavity, and the fixed core and the movable core are in close contact with each other. and a slide core that moves forward and backward in a direction perpendicular to the moving direction of the movable core to form a cavity on the undercut shape side of the product, and a shape core having one end fixed to the slide core and the other end in close contact with the movable core do.

In this case, it is preferable that the moving direction of the movable core is horizontal to the ground, and the moving direction of the slide core is perpendicular to the ground or at an angle that can be stably fixed in the shape of the core according to it.

In addition, an outer undercut forming part including a shape core fastening part to which one end side of the shape core is coupled is formed on the slide core, and a shape core contact part to which the other end side of the shape core is in close contact is formed on the movable core. have.

Moreover, it is preferable that the material of the said shape core is steel.

On the other hand, the shape core removal type die casting method according to the present invention includes a shape core fastening step of coupling one end of a shape core to a shape core fastening part formed on a slide core, and the slide core advances so that the other end of the shape core is attached to the movable core. A slide core advancing step in close contact with the formed shape core adhesion portion, a moving core advancing step advancing the movable core and adhering to the fixed core, pressing the molten metal into a cavity formed by the fixed core and the movable core and the slide core, Cooling the product forming step, the movable core reversing step in which the movable core moves backward, the slide core reversing step in which the slide core retracts, the product separation step in which the product is separated from the movable core by an eject pin, and slide the shape core into the slide and a shape core separation step of separating the shape core from the product (P) by striking in the forward direction of the core.

In this case, it is preferable that the molten metal is aluminum or an aluminum alloy, and the material of the shape core is steel.

As described above, in the shape core removable die casting mold and the die casting method using the same according to the present invention, there is no need to perform separate machining by means of a shape core in which one end is coupled to the sliding core and the other end is in close contact with the movable core. Since the undercut part can be molded, the productivity of various aluminum products including the inner undercut part can be improved.

In addition, the shape core removable die casting mold and the die casting method using the same according to the present invention can prevent an increase in the defect rate of the product due to machining for forming the inner undercut part.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is a side cross-sectional view showing an example of a product including an inner undercut.
Figure 2 is a cross-sectional view showing a state in which the shape core removable die-casting mold according to an embodiment of the present invention is coupled.
3 is a cross-sectional view illustrating a state in which the shape core removable die casting mold according to an embodiment of the present invention is separated.
4 is a flowchart of a shape core removable die casting method according to an embodiment of the present invention.
5 is a cross-sectional view showing each step of the shape core removable die casting method according to an embodiment of the present invention.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention.

In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

In the following, that an arbitrary component is disposed on the "upper (or lower)" of a component or "upper (or below)" of a component means that any component is disposed in contact with the upper surface (or lower surface) of the component. Furthermore, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

In addition, when it is described that a component is “connected”, “coupled” or “connected” to another component, the components may be directly connected or connected to each other, but other components are “interposed” between each component. It should be understood that “or, each component may be “connected,” “coupled,” or “connected” through another component.

As used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

Throughout the specification, when “A and/or B” is used, it means A, B or A and B, unless specifically stated to the contrary, and when “C to D” is used, it means that there is no specific contrary description. Unless otherwise specified, it means that it is greater than or equal to C and less than or equal to D.

Hereinafter, a shape core removable die casting mold and a die casting method using the same according to some embodiments of the present invention will be described.

2 and 3 are cross-sectional views each showing a state in which the shape core removable die-casting mold is coupled and separated according to an embodiment of the present invention.

Referring to FIGS. 2 and 3 , the shape core removable die casting mold according to the present invention includes a fixed core 100 , a movable core 200 , a slide core 300 , and a shape core 400 .

More specifically, the fixed core 100 includes a fixed core holder 110 , and is combined with the movable core 200 and the slide core 300 to form a cavity C in the shape of a product P.

In addition, the movable core 200, including the movable core holder 210 and the eject pin 220, can be moved forward/backward toward the fixed core 100 by a press device or a hydraulic/pneumatic cylinder.

At this time, the eject pin 220 may be a hydraulic or pneumatic cylinder installed on the outside of the movable core holder 210 , and the movable core 200 moves so as to protrude or sink toward the fixed core 100 . You can move forward/backward in any direction.

In addition, the movable core 200 includes a shape core contact part 201 formed in a straight section so that the end of the shape core 400 can be closely attached.

In addition, the slide core 300 includes an outer undercut forming part 301 including a shape core fastening part 301a to which one side of the shape core 400 is coupled, and a slide core holder 310 including a press device or It can move forward/backward in a direction orthogonal to the moving direction of the movable core 200 by a hydraulic cylinder or the like.

At this time, the outer undercut forming part 301 has a shape of a portion formed in the backward direction of the slide core 300 among the undercut shapes of the product P.

More preferably, in the shape core removable die casting mold according to the present invention, the moving direction of the movable core 200 is horizontal to the ground, and the moving direction of the slide core 300 is perpendicular to the ground or corresponding to the shape core 400 ) may be an angle that can be stable for fixing.

For example, the angle of the movement direction of the slide core 300 may be any one of straight lines within 0 to 70° on both sides based on an imaginary straight line perpendicular to the ground.

At this time, it is preferable that the surface on which the shape core contact part 201 is formed is formed to be perpendicular to the moving direction of the slide core 300 .

In addition, the shape core 400 is made of a steel material and is formed in the shape of the inner undercut part of the product P, and one end is coupled to the shape core fastening part 301a and other according to the advancement of the slide core 300 . The end may be in close contact with the shape core contact portion 201 .

In this case, the shape of the inner undercut part is the shape of the part formed in the reverse direction to the reverse direction of the undercut shape of the slide core 300 of the product P.

That is, in the shape core detachable die casting mold according to the present invention, when molten metal is injected into the cavity (C) at high speed and high pressure, the shape core 400 having an inner undercut shape blocks the molten metal, so that the product ( It is to implement the inner undercut shape of P).

On the other hand, as described above, when the angle of the movement direction of the slide core 300 is inclined to one side based on a virtual straight line perpendicular to the ground, the shape core is in close contact with the shape core contact part 201 . The surface on which the other end of the 400 is formed is preferably formed to be perpendicular to the moving direction of the slide core 300 .

In addition, the product molded by the shape core removable die-casting mold according to the present invention may be various metal parts including the differential carrier of the automobile as shown in FIG. 1 .

On the other hand, Figure 4 is a flow chart of the shape core removable die casting method according to an embodiment of the present invention, Figure 5 is a cross-sectional view showing each step of the shape core removable die casting method according to an embodiment of the present invention.

A die casting method using a shape core removable die casting mold according to the present invention configured as described above with reference to FIGS. 4 and 5 is as follows.

The shape core removal type die casting method according to the present invention includes a shape core fastening step (S100), a slide core advancing step (S200), a movable core advancing step (S300), a product forming step (S400), a slide core reversing step (S500), a moving core backward step (S600), a product separation step (S700) and a shape core separation step (S800).

More specifically, in the shape core fastening step (S100), the movable core 200 and the slide core 300 are respectively reversed and the shape core 400 is connected to the shape core fastening part while the mold is maintained in a separated state. Bind to (301a).

In this case, the shape-core fastening part 301a may be formed as a protrusion or a groove, and may have various shapes depending on the shape of the product to be molded.

In addition, the outer undercut forming part 301 in which the shape core fastening part 301a is formed is an outer undercut shape of the product P, and the shape core 400 is an inner undercut shape of the product P desirable.

Meanwhile, in the slide core advancing step (S200), as the slide core 300 advances toward the movable core 200 by a press device or a hydraulic cylinder, the other end of the shape core 400 is in contact with the shape core. (201) is attached.

In addition, in the moving core advancing step (S300), the movable core 200 to which the sliding core 300 is coupled is advanced toward the fixed core 100 by a press device or a pneumatic cylinder, and the fixed core 100 and The coupling of the movable core 200 and the slide core 300 is completed.

Accordingly, a cavity C having the same shape as that of the product P is formed between the fixed core 100 and the movable core 200 and the slide core 300 .

On the other hand, in the product forming step (S400), the molten metal of aluminum or aluminum alloy is injected into the cavity (C) at high speed and high pressure and then cooled.

That is, the product P made of aluminum or aluminum alloy is positioned in the cavity C.

At this time, when the shape core 400 is made of the same aluminum or aluminum alloy material as the product P, deformation and fusion may occur depending on the shape, so that the shape core 400 is preferably made of steel.

In addition, the material of the shape core 400 is not limited to steel, and may be a metal or a non-metal having rigidity and heat resistance corresponding thereto.

Thereafter, the movable core reversing step (S500) and the slide core reversing step (S600) in which the movable core 200 and the slide core 300 are sequentially moved backward by a press device or a hydraulic cylinder, etc. are performed, so that the fixed core Separation of 100 and the movable core 200 and the slide core 300 is completed.

Meanwhile, in the product separation step (S700), as shown in FIG. 5 , the ejector pin 220 is in a state where the separation of the fixed core 100 , the movable core 200 , and the slide core 300 is completed. As it advances toward the fixed core 100 , the product P is separated from the movable core 200 together with the shape core 400 .

Thereafter, the shape core separation step (S800) of separating the shape core 400 from the product P by striking the shape core 400 in the forward direction of the slide core 300 is performed, so that the product ( Forming of P) is completed.

In this case, a tool such as a hammer or a press device may be used to strike the shape core 400 .

Accordingly, the shape core removable die casting mold and the die casting method using the same according to the present invention can mold the inner undercut without the need to perform separate machining, so the quality and productivity of various aluminum products including the inner undercut can be improved. have.

As described above, the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed in the present specification. It is obvious that variations can be made.

In addition, although the effects according to the configuration of the present invention have not been explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

C. cavity
P. product
S100. Shape core fastening step
S200. Slide core forward step
S300. Moving core forward stage
S400. product forming stage
S500. slide core backward step
S600. moving core backward step
S700. Product separation stage
S800. Shape core separation step
100. Fixed core
110. Fixed core holder
200. Movable core
201. Shaped core adhesion part
210. Movable core holder
220. Eject pin
300. Slide Core
301. Outer undercut forming part
301a. shape core fastening part
310. Slide Core Holder
400. shape core

Claims (5)

fixed core;
a movable core that is in close contact with the fixed core, including an ejector pin, and moves forward and backward to form a product-shaped cavity;
a slide core which is in close contact with the fixed core and the movable core, respectively, and moves forward and backward to form a cavity on the undercut portion-shaped side of the product; and
A shape core removable die-casting mold comprising a; a shape core having one end fixed to the slide core and the other end in close contact with the movable core.
The method of claim 1,
The moving direction of the movable core is horizontal to the ground,
The moving direction of the slide core is any one of straight lines within 0 to 70° on both sides based on an imaginary straight line perpendicular to the ground.
The method of claim 1,
An outer undercut forming part including a shape core fastening part to which one end side of the shape core is coupled is formed on the slide core;
A shape core contact portion to which the other end side of the shape core is in close contact is formed on the movable core,
The shape core is a shape core removable die casting mold made of steel.
a shape core fastening step of coupling one end of a shape core to a shape core fastening part formed on the slide core;
a slide core advancing step in which the slide core is advanced and the other end of the shape core is in close contact with a shape core contact portion formed on the movable core;
a moving core advancing step of advancing the moving core and adhering to the fixed core;
a product forming step of pressing and cooling molten metal into a cavity formed by the fixed core, the movable core, and the slide core;
a moving core reversing step in which the movable core retracts;
a slide core reversing step in which the slide core retracts;
a product separation step in which the product is separated from the movable core by an eject pin; and
A shape core removal type die casting method comprising a; a shape core separation step of separating the shape core from the product (P) by striking the shape core in the forward direction of the slide core.
5. The method of claim 4,
The molten metal is aluminum or an aluminum alloy,
The shape core is a shape core removable die casting method of a steel material.

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