KR102468948B1 - Separable Core Type Die Casting Mold And Die Casting Method Using Thereof - Google Patents

Abstract

The present invention includes a fixed core, an ejector pin, and a movable core that moves forward and backward to form a cavity in the shape of a product in close contact with the fixed core, and a cavity on the side of the undercut portion shape of the product that is in close contact with the fixed core and the movable core. It includes a slide core that moves forward and backward to form and a shaped core whose one end is fixed to the slide core and whose other end is in close contact with the movable core.

Description

Shape Core Type Die Casting Mold and Die Casting Method Using The Same {Separable Core Type Die Casting Mold And Die Casting Method Using Thereof}

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

In general, die casting refers to manufacturing a cast molded product identical to the mold by injecting molten metal into a mold of steel machined to match a shape to be molded.

Since such die casting has high dimensional accuracy and can easily manufacture precision products having complex shapes, it is widely used in various fields, and is particularly commonly used in the production of automobile parts.

However, in the case of molding relatively complex products in such die casting, the direction of subtraction of the mold core. That is, the undercut shape, which is a shape formed in the reverse direction in 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. When it is manufactured using a die-casting mold, the outer undercut portion (OUC) can be molded using a sliding core, but the inner undercut portion (OUC) can be molded. 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 the inner undercut is produced by die casting, there are problems in that the manufacturing time is increased due to the molding of the inner undercut and the air bubble isolation and the occurrence rate of shrinkage cavity in the inner undercut are remarkably high.

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

Such a conventional injection mold molds the undercut portion by assembling the mold in a state in which the molding ring is coupled to the undercut portion and injecting the molding liquid to prevent injection of the molding liquid into the position of the molding ring.

However, these conventional injection molds are for molding products made of synthetic resin rather than aluminum, and in the case of aluminum die casting, aluminum is melted at a temperature of at least 650 ° C. and injected into the mold at high pressure and high speed to form a rubber or elastic molding ring. Since this melts and the forming of the undercut part is not performed, it cannot be applied to aluminum die casting.

Republic of Korea Patent Publication No. 10-2015-0135563 (published on 2015.12.03.)

An object of the present invention has been made to solve the above-mentioned problems, and to provide a shape core removal type 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. is to do

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned above can 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 means of the instrumentalities and combinations indicated in the claims.

In order to solve the above problems, the shape core removal type die casting mold according to the present invention is a fixed core, a movable core that is in close contact with the fixed core and moves forward and backward to form a cavity of a product shape, and is in close contact with the fixed core and the movable core, respectively. 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 side of the undercut portion of the product, and a shaped core having one end fixed to the slide core and the other end in close contact with the movable core do.

At this time, 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 an angle similar to that at which the shape core can be stably fixed.

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

In addition, it is preferable that the material of the shape core is steel.

On the other hand, in the shape core removal type die casting method according to the present invention, the shape core fastening step of coupling one end of the shape core to the shape core fastening part formed on the slide core, the slide core moves forward, and the other end of the shape core attaches to the movable core. The step of advancing the slide core in close contact with the formed shape core, the step of advancing the movable core in which the movable core advances and adheres to the fixed core, presses the molten metal into the cavity formed by the fixed core, the movable core, and the slide core, A product forming step of cooling, a movable core retracting step of retracting the movable core, a slide core retracting step of retracting the slide core, a product separating step of separating the product from the movable core by an eject pin, and the slide core and a shape core separating step of separating the shape core from the product (P) by striking the core in the forward direction.

At this time, 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, the core-removable die-casting mold and the die-casting method using the same according to the present invention have one end coupled to the sliding core and the other end in close contact with the movable core, without the need for separate machining. Since the undercut portion can be molded, the productivity of various aluminum products including the inner undercut portion can be improved.

In addition, the core removal type die-casting mold and the die-casting method using the mold according to the present invention can prevent an increase in the defect rate of a product due to machining for forming an inner undercut portion.

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

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

The above objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention belongs will be able to easily implement the technical spirit of the present invention.

In describing the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter 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.

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

In addition, when a component is described as "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but other components may be "interposed" between each component. ", or each component may be "connected", "coupled" or "connected" through other components.

Singular expressions used herein include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or some of the steps It should be construed that it may not be included, or may further include additional components or steps.

Throughout the specification, when "A and/or B" is used, this means A, B or A and B unless otherwise specified, and when used as "C to D", this means unless otherwise specified As long as there is no, it means C or more and D or less.

Hereinafter, a core removal type die-casting mold and a die-casting method using the mold according to some embodiments of the present invention will be described.

2 and 3 are cross-sectional views showing a combined state and a separated state of the core removal type die-casting mold according to an embodiment of the present invention, respectively.

Referring to FIGS. 2 and 3 , the shape core removal type 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 stationary core 100 includes a stationary core holder 110, and is combined with the movable core 200 and the slide core 300 to form a cavity C having a shape of a product P.

In addition, the movable core 200 includes the movable core holder 210 and the eject pin 220 and can move forward/reverse toward the fixed core 100 by means of a press device or hydraulic/pneumatic cylinder.

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

In addition, the movable core 200 includes a shape core contact portion 201 formed in a straight section so that the end portion of the shape core 400 can come into close contact with each other.

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

At this time, the outer undercut forming part 301 has a shape of a part 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 similarly to the shape core 400 ) can be an angle that can be stable for fixing.

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

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

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

At this time, the shape of the inner undercut portion is the shape of a portion formed opposite to the undercut shape of the product P in the backward direction of the slide core 300 .

That is, in the shape core removal type 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 in the moving direction of the slide core 300 is formed inclined to one side based on a virtual straight line perpendicular to the ground, the shape core adhered to the shape core contact portion 201 It is preferable that the surface on which the other end of 400 is formed is orthogonal to the moving direction of the slide core 300.

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

On the other hand, Figure 4 is a flow chart of a shape core removal type 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 removal type die casting method according to an embodiment of the present invention.

A die-casting method using the shape core removal type 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 sequentially proceeds a shape core fastening step (S100), a slide core advancement step (S200), a movable core advancement step (S300), a product forming step (S400), and a slide core backward step. (S500), moving core backward step (S600), product separation step (S700), and shape core separation step (S800).

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

At this time, the shape core fastening portion 301a may be formed as a protrusion or groove, and may have various shapes depending on the shape of a product to be molded.

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

On the other hand, in the slide core advancing step (S200), as the slide core 300 advances toward the movable core 200 by means of a press device or a hydraulic/pneumatic cylinder, the other end of the shaped core 400 is in close contact with the shaped core 400. Adhere to (201).

In the step of advancing the movable core (S300), the movable core 200 to which the sliding core 300 is coupled is advanced toward the stationary core 100 by a press device or a hydraulic/pneumatic cylinder to move the stationary 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 the product P is formed between the stationary core 100, the movable core 200, and the slide core 300.

Meanwhile, in the product forming step (S400), 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.

In this case, if the shape core 400 is made of the same aluminum or aluminum alloy material as the product P, deformation or fusion may occur depending on the shape, so 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 non-metal having similar rigidity and heat resistance.

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

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

Thereafter, a shape core separation step (S800) of separating the shape core 400 from the product P by hitting the shape core 400 in the forward direction of the slide core 300 is performed, and the product ( The molding of P) is completed.

At this time, a tool such as a hammer or a press device may be used to strike the shaped core 400 .

Accordingly, since the core-removable die-casting mold and the die-casting method using the die-casting mold according to the present invention can mold the inner undercut without the need for additional machining, 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 drawings illustrated, but the present invention is not limited by the embodiments and drawings disclosed in this specification, and various modifications are made by those skilled in the art within the scope of the technical idea of the present invention. It is obvious that variations can be made.

In addition, although the operational 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 corresponding configuration should also be recognized.

C. Cavity
P. Product
S100. Form core fastening step
S200. slide core progress
S300. movable core advance stage
S400. Product molding stage
S500. slide core backward step
S600. movable core backward step
S700. Product Separation Stage
S800. Form core separation step
100. Fixed core
110. Fixed core holder
200. Moving core
201. Form core contact part
210. Movable core holder
220. Eject pin
300. Slide core
301. Outer undercut molding
301a. shape core fastening part
310. Slide core holder
400. Form core

Claims (5)

fixed core;
A movable core including an ejector pin that moves forward and backward to form a cavity in the shape of a product in close contact with the fixed core;
a slide core that comes into close contact with the stationary core and the movable core and moves forward and backward to form a cavity in the shape of the undercut portion of the product; and
It is formed in the shape of an inner undercut of the product, one end is fixed to the slide core, and the other end is in close contact with the movable core; includes,
The slide core includes an outer undercut forming part formed in the backward direction of the slide core and a shaped core fastening part formed on the outer undercut forming part and coupled to one end side of the shaped core,
The movable core is formed with a shape core contact portion to which the other end side of the shape core adheres.
The shape core is a shape core removal type die casting mold made of steel.
According to 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 the straight lines within 0 to 70 ° on both sides based on a virtual straight line perpendicular to the ground.
delete fixed core;
A movable core including an ejector pin that moves forward and backward to form a cavity in the shape of a product in close contact with the fixed core;
a slide core that comes into close contact with the stationary core and the movable core and moves forward and backward to form a cavity in the shape of the undercut portion of the product; and
It is formed in the shape of an inner undercut of the product, one end is fixed to the slide core, and the other end is in close contact with the movable core; includes,
The slide core includes an outer undercut forming part formed in the backward direction of the slide core and a shaped core fastening part formed on the outer undercut forming part and coupled to one end side of the shaped core,
In the shape core removal type die casting method using a shape core removal type die casting mold in which a shape core contact portion to which the other end side of the shape core is in close contact with the movable core is formed,
a shape core fastening step of coupling one end of the shape core to the shape core fastening unit;
a slide core advancing step in which the slide core advances and the other end of the shape core is brought into close contact with the shape core contact portion;
advancing the movable core so that the movable core moves forward and adheres 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 movable core retracting step of retracting the movable core;
a slide core backward step in which the slide core moves backward;
A product separation step of separating a product from the movable core by the eject pin; and
and a shape core separation step of separating the shape core from the product by hitting the shape core in a forward direction of the slide core.
According to claim 4,
The molten metal is aluminum or an aluminum alloy,
The shape core is a shape core removal type die casting method made of steel.

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