KR20140006145A - Cold chamber die-casting apparatus - Google Patents

Abstract

Disclosed is a low temperature chamber die-casting apparatus. The low temperature chamber die-casting apparatus of the present invention includes: a mold including a cavity for responding to the shape of a product, a die formed with a runner which pours molten metal into the cavity, and a die plate formed with a molten metal pouring flow path and fixes the die; a sleeve formed with a molten metal outlet in which a space is formed for receiving the molten metal flowed in through the molten metal pouring flow path and which is in connection the runner; and a plunger arranged inside the sleeve for pressurizing the molten metal received inside the said space.

Description

[0001] The present invention relates to a cold chamber die-casting apparatus,

The present invention relates to a low temperature chamber die casting apparatus, and more particularly, to a low temperature chamber die casting apparatus in which molten metal is injected into a cavity by pressurizing the molten metal with a plunger.

Die casting is performed by injecting a molten metal into a cavity of a mold through a sleeve or a nozzle and injecting the piston at a low speed and at a high speed by using the force of a hydraulic cylinder connected to the injection machine and maintaining the inside of the cavity at a high pressure until solidification is completed Means a casting method in which the quality of a product can be improved by minimizing shrinkage bubbles inside the casting.

In recent years, electronic products such as mobile phones with a metal case have been spotlighted. Therefore, attempts have been made to manufacture the metallic case as a final product, and a die casting method has been widely used for manufacturing such metallic cases.

In the case of producing a product using such a die casting, since the dimensions of the final product are accurate, it is not necessary to finely polish it, and besides, the product has excellent mechanical properties and mass production.

The products using diecasting have many automobile parts and they are widely used for mass production of elaborate products such as electric devices, optical instruments, vehicles, textile machines, construction and measuring instrument parts.

FIG. 1 is a view showing a state where a molten metal is injected into a conventional low temperature chamber die casting apparatus, and FIG. 2 is a view showing a state where a molten metal is injected into a conventional low temperature chamber die casting apparatus.

1 and 2, the conventional low-temperature chamber die casting apparatus has a sleeve 23 protruding outside the die plate 12, and a molten metal injection path 24 is formed in the protruding portion of the sleeve 23 .

3 is a view showing a state where the molten metal is pressurized by a plunger of a conventional low temperature chamber die casting apparatus.

3, since the distance between the molten metal injection channel 24 and the runner 22 is long, the plunger 25 pushes the molten metal 1 at a low speed, The plunger 25 presses the molten metal 1 at a high speed to cause the molten metal 1 to reach the cavity 21. [ Therefore, as the time for the molten metal 1 to be positioned in the sleeve 23 is prolonged, the time for which the molten metal 1 is in contact with the atmosphere can also be prolonged.

4 is a simulation result showing a temperature drop of the molten metal with time in which the molten metal of the conventional low temperature chamber die casting apparatus stays in the sleeve.

4, according to the conventional low-temperature chamber die casting apparatus, the time for the melt 1 to be positioned in the sleeve 23 is prolonged, and the abrupt temperature drop of the melt 1 contained in the sleeve 23 can occur .

Generally, low temperature chamber die casting is widely used for injection of thin and lightweight articles such as special mobile phone cases. Temperature management is particularly important when die-casting such thin and lightweight articles.

However, in the case of the conventional low-temperature chamber die casting apparatus, since the time for the molten metal 1 to be positioned in the sleeve 23 is long, the oxide generated by the molten metal 1 in contact with the atmosphere and the molten metal 1 by the plunger 25, The impurities due to inclusion of the gas inside the sleeve 23 are directly introduced into the cavity 21 while moving inside the sleeve 23. Therefore, the possibility of a defect in the surface of a thin and lightweight product can be very high, and accordingly, the failure rate of the product can also be increased.

In addition, magnesium alloy die casting can not be performed due to a rapid temperature drop of the molten metal 1, and there is a problem that material loss is very large.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned problems, and an object of the present invention is as follows.

First, the present invention provides a low-temperature chamber die casting apparatus capable of preventing the temperature of the molten metal from being drastically lowered.

Second, the present invention provides a low-temperature chamber die casting apparatus capable of minimizing the generation of oxides generated by contact of the molten metal with the atmosphere and the inclusion of air in the molten metal.

Third, the present invention provides a low temperature chamber die casting apparatus capable of reducing the size and weight of the apparatus itself.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the low temperature chamber die casting apparatus according to an embodiment of the present invention may include a mold part, a sleeve, and a plunger.

The mold part may include a die and a die plate.

A cavity corresponding to the shape of the product and a runner into which the molten metal is injected may be formed inside the die.

A molten metal injection path may be formed in the die plate.

The sleeve may have a space formed therein to receive the molten metal flowing through the molten metal injection path, and a molten metal outlet connected to the runner.

The plunger may be disposed inside the sleeve to press the molten metal contained in the space.

The sleeve may include a first part and a second part.

The first part may be located inside the die. In the first part, a molten metal outlet communicating with the runner may be formed.

The second part may be located inside the die plate. In addition, a molten metal injection hole communicating with the molten metal injection channel may be formed in the second part.

The inlet of the molten metal injection path may be provided with a molten metal injection guide for guiding the molten metal into the molten metal injection path.

In addition, a heat insulating member may be further provided on the outer side of the portion of the sleeve where the molten metal is located to prevent the temperature of the molten metal from rapidly dropping.

The effects of the present invention will be described below.

First, according to the low-temperature chamber die casting apparatus of the present invention, the outlet of the molten metal injection path and the entrance of the runner are disposed so as to be adjacent to each other as much as possible, and the time for the molten metal to be positioned in the sleeve is shortened.

Second, according to the low temperature chamber die casting apparatus of the present invention, the time for the molten metal to contact with the atmosphere is shortened, and the generation of the oxides generated by the contact of the molten metal with the atmosphere and the inclusion of air in the molten metal can be minimized.

Thirdly, according to the low-temperature chamber die casting apparatus of the present invention, the exit of the molten metal injection path and the entrance of the runner are arranged so as to be as close as possible to shorten the travel distance of the plunger, so that the length of the sleeve can be shortened. Thus, the size and weight of the low-temperature chamber die casting apparatus itself can be reduced.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

The foregoing summary, as well as the detailed description of the preferred embodiments of the present application set forth below, may be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown preferred embodiments in the figures. It should be understood, however, that this application is not limited to the precise arrangements and instrumentalities shown.
1 is a view showing a state where a molten metal is injected into a conventional low temperature chamber die casting apparatus;
FIG. 2 is a view showing a state where a molten metal is injected into a conventional low temperature chamber die casting apparatus; FIG.
3 is a view showing a state where the molten metal is pressurized by a plunger of a conventional low-temperature chamber die casting apparatus;
FIG. 4 is a simulation result showing the temperature drop of the molten metal with time in the conventional low temperature chamber die casting apparatus staying in the sleeve;
5 is a view illustrating a state where a molten metal is injected into a low temperature chamber die casting apparatus according to an embodiment of the present invention;
6 is an enlarged view of a sleeve of a low temperature chamber die casting apparatus according to an embodiment of the present invention;
FIG. 7 is a view showing a state where the molten metal is pressurized by a plunger of a low temperature chamber die casting apparatus according to an embodiment of the present invention; FIG.
Figure 8 shows a casting (a) cast by a low temperature chamber die casting apparatus and a casting (b) cast by a conventional die casting apparatus according to an embodiment of the present invention for sample collection;
Fig. 9 shows the results of ultrasonic treatment of specimen a; And
Fig. 10 shows the ultrasonic treated specimen (b).

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the appended drawings illustrate the present invention in order to more easily explain the present invention, and the scope of the present invention is not limited thereto. You will know.

In describing the embodiments of the present invention, it is to be noted that elements having the same function are denoted by the same names and numerals, but are substantially not identical to elements of the prior art.

Also, the terms used in the present application are used only to describe certain embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

FIG. 5 is a view illustrating a state where a molten metal is injected into a low temperature chamber die casting apparatus according to an embodiment of the present invention.

The configuration and structure of the low temperature chamber die casting apparatus according to one embodiment of the present invention will be described with reference to FIG.

4, the low temperature chamber die casting apparatus according to an embodiment of the present invention may include a mold part, a sleeve 230, and a plunger 240. As shown in FIG.

The mold part may include a die 110 and a die plate 120.

A cavity 210 corresponding to the product shape and a runner 220 into which the molten metal is injected into the cavity 210 may be formed in the die 110.

The die plate 120 can secure the die 110. The die plate 120 may be provided with a molten metal injection flow path 122.

At this time, a molten metal injection guide 124 for guiding the molten metal 1 to the molten metal injection flow path 122 may be provided at the entrance of the molten metal injection path 122.

The sleeve 230 may be provided with a space for receiving the molten metal 1 flowing through the molten metal injection path 122 and forming a molten metal outlet 231a communicating with the runner 220.

The plunger 240 is disposed inside the sleeve 230 to press the molten metal 1 contained in the space. At this time, the plunger 240 can press the melt 1 in the direction in which the runner 220 is positioned after the melt 1 is injected into the sleeve 230. Therefore, the molten metal 1 can reach the cavity 210 through the runner 220.

In general, the sleeve 230 may be cylindrical with a hollow, and the surface of the plunger 240 in contact with the melt 1 may conform to the shape of the longitudinal section of the sleeve 230. However, the shapes of the sleeve 230 and the plunger 240 are not limited thereto.

6 is an enlarged view of a sleeve of a low temperature chamber die casting apparatus according to an embodiment of the present invention.

As shown in FIG. 6, the sleeve 230 may include a first part 231 and a second part 232.

The first part 231 may be located inside the die 110. In the first part 231, a molten metal outlet 231a communicating with the runner 220 may be formed. The molten metal outlet 231a may be located at a portion where the runner 220 and the first part 231 are in contact with each other.

The second part 232 may be located inside the die plate 120. The second part 232 may be formed with a molten metal inlet 232a communicating with the molten metal inlet flow path 122. The molten metal injection port 232a may be located at a portion where the second part 232 and the molten metal injection path 122 are in contact with each other.

At this time, the molten metal outlet 231a and the molten metal inlet 232a may be formed as close as possible to each other.

Therefore, the time for the molten metal 1 to stay in the sleeve 230 is shortened, and the temperature of the molten metal 1 can be prevented from dropping rapidly. Further, since the time for which the molten metal 1 comes into contact with the atmosphere until reaching the cavity 210 is also shortened, the generation of oxides due to contact with the atmosphere of the molten metal 1 can be minimized.

The second part 232 of the sleeve 230 may be located inside the die plate 120 without a portion protruding outward of the die plate 120. According to an embodiment of the present invention, since the outlet of the molten metal inflow passage 122 is formed as close as possible to the entrance of the runner 220, the travel distance of the molten metal 1 is shortened, The distance traveled can also be shortened.

The length of the guide passage 230 and the movement path of the plunger 240 is also shortened so that the sleeve 230 is completely positioned inside the die plate 120 without being protruded to the outside of the die plate 120 can do. Therefore, it is possible to reduce the size and weight of the low-temperature chamber die casting apparatus itself.

However, it is only one example of the present invention that the sleeve 230 is located inside the die plate 120, and the length and shape of the sleeve 230 can be varied in any way as long as the plunger 240 is movable. Lt; / RTI >

7 is a view showing a state where the molten metal is pressurized by a plunger of a low temperature chamber die casting apparatus according to an embodiment of the present invention.

7, the plunger 240 can press the molten metal 1 accommodated in the sleeve 230 at a high speed in the direction in which the runner 220 is positioned.

At this time, the plunger 240 can be actuated by the hydraulic pressure. However, the operation of the plunger 240 is not limited thereto, and may be variously performed in a manner that allows the plunger 240 to reciprocate at an appropriate speed.

On the other hand, a heat insulating member (not shown) for preventing the temperature of the molten metal 1 from abruptly lowering can be further provided on the outer side of the portion of the sleeve 230 where the molten metal 1 is located.

In the conventional low temperature chamber die casting apparatus, the sleeve 23 protrudes outside the die plate 12, and the molten metal injection flow passage 24 is formed in the protruding portion of the sleeve 23. The plunger 25 pushes the molten metal 1 at a low speed and moves the molten metal 1 to the high speed injection position after the distance between the molten metal inflow passage 24 and the runner 22 is long, The molten metal 1 is pressurized at a high speed so that the molten metal 1 reaches the cavity 21 (see FIGS. 1 to 3). Therefore, the time for the molten metal 1 to be positioned in the sleeve 23 can be prolonged. Further, since the time for which the molten metal 1 is in contact with the atmosphere is also prolonged, a rapid temperature drop of the molten metal 1 may occur (see Fig. 4).

Generally, low temperature chamber die casting is widely used for injection of thin and lightweight articles such as special mobile phone cases. At this time, the impurities caused by the inclusion of the gas inside the sleeve 23 while the molten metal 1 moves inside the sleeve 23 by the platinum 25 and the oxide generated by the contact of the molten metal 1 with the atmosphere, And flows into the cavity 21. Therefore, there is a high possibility that a defect occurs on the surface of a thin and lightweight product.

In addition, magnesium alloy die casting can not be performed due to a rapid temperature drop of the molten metal 1, and there is a problem that material loss is very large.

However, according to the low-temperature chamber die casting apparatus according to the embodiment of the present invention, the exit of the molten metal injection path 122 and the entrance of the runner 220 are located as close as possible to each other, so that the travel distance of the molten metal 1 can be shortened . Therefore, since the movement distance of the plunger 240 is also shortened, the length of the sleeve 230 can be shortened. Thus, it is possible to reduce the size and weight of the low temperature chamber die casting apparatus itself.

In addition, a heat insulating member (not shown) may be provided on the outer side of the portion of the sleeve 230 where the molten metal 1 is located. Then, the plunger 240 can press the melt 1 at a high speed without a low speed section. As a result, the time for the molten metal 1 to be positioned in the sleeve 230 is shortened, and the temperature of the molten metal 1 can be prevented from dropping rapidly. Further, the molten metal 1 at a high temperature can reach the cavity 210 before the temperature is lowered.

It is also possible to minimize the generation of oxides and the inclusion of air in the molten metal 1 due to the contact time of the molten metal 1 with the atmosphere being shortened. Therefore, even in the case of a thin and lightweight product, excellent surface quality of the product can be expected.

Further, the present invention can be widely applied to magnesium diecasting in which the solidification rate of the molten metal 1 is important.

8 is a view showing a casting a cast by a low temperature chamber die casting apparatus according to an embodiment of the present invention for sample collection and a casting cast b by a conventional die casting apparatus.

Hereinafter, the porosity and the oxide test of the aluminum specimen will be described with reference to FIG.

, 현수무게

, 포수무게

을 측정하고, 물질의 이론밀도

를 구하여 다공성 물질의 비중

, 전체 기공의 양

, 개기공의 양

, 폐기공의 양

를 측정하였다.The porosity of the porous material can be measured by the Archimedes method. Dry weight

, Suspension weight

, Catcher weight

And the theoretical density of the material

And the specific gravity of the porous material

, The amount of total pore

, Amount of dog pores

, Amount of waste ball

Were measured.

As shown in FIG. 8, specimen (a) was cast by a low temperature chamber die casting apparatus according to an embodiment of the present invention, and specimen (b) was cast by a conventional die casting apparatus.

First, the weight of each specimen was measured. At this time, the weight of the catcher was added to the boiling water and the surface active agent was added to the water for 2 hours. Weighed in water and then weighed.

은 4.3953, 현수무게

는 2.7841, 포수무게

은 4.3964이며, 이론밀도

는 2.76이다.As a result of weighing, the dry weight of the specimen (a)

4.3953, Suspension Weight

2.7841, catcher weight

Is 4.3964, and theoretical density

Is 2.76.

The specific gravity of specimen (a) can be calculated by Equation (1) as follows.

<Formula 1>

은 다음과 같이 <식 2>에 의해 계산될 수 있다.
Then, the amount of total pores of the specimen (a)

Can be calculated by Equation (2) as follows.

<Formula 2>

와 폐기공의 양

는 다음과 같이 <식 3> 및 <식 4>에 의해 계산될 수 있다.
The amount of open pores of the specimen (a)

And the amount of waste ball

Can be calculated by Equation (3) and Equation (4) as follows.

<Formula 3>

<Equation 4>

은 6.1212, 현수무게

는 3.8534, 포수무게

은 6.1225이며, 이론밀도

는 시편(a)와 같이 2.76이다.On the other hand, the dry weight of the specimen (b)

6.1212, Suspension Weight

3.8534, catcher weight

Is 6.1225, and the theoretical density

Is 2.76 as for the sample (a).

The specific gravity of the specimen (b) is shown in Equation (5).

&Lt; EMI ID =

는 다음의 <식 6>과 같다.
The amount of total pores of specimen (b)

Is expressed by Equation (6) below.

&Lt; EMI ID =

와 폐기공의 양

는 다음과 같이 <식 7> 및 <식 8>에 의해 계산될 수 있다.
The amount of open pores in the specimen (b)

And the amount of waste ball

Can be calculated by Equation (7) and Equation (8) as follows.

<Equation 7>

<Equation 8>

Accordingly, it can be seen that the porosity of the specimen (a) cast by the low temperature chamber die casting apparatus according to an embodiment of the present invention is smaller than that of the specimen (b) cast by the conventional die casting apparatus.

The specimens (a) and (b) were ultrasonically cleaned in tap water for 5 minutes, and then the specimens were observed.

Fig. 9 is a specimen (a) subjected to ultrasonication.

As can be seen from Fig. 9, pores were hardly observed on the polishing surface of the specimen (a), and no apparent change was observed after the ultrasonic treatment.

Fig. 10 shows the ultrasonic treated specimen (b).

As shown in Fig. 10, a considerable amount of pores can be observed on the polishing surface of the test piece (b). After the ultrasonic treatment, a white patterned oxide film was observed on the surface of the test piece (b).

As with the above-described experimental results, the casting cast by the low-temperature chamber die casting apparatus according to an embodiment of the present invention has less air content and less oxide generation than the casting cast by the conventional die casting apparatus, .

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. It is obvious to them. Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

1: molten metal 11: die
12: die plate 21: cavity
22: Runner 23: Sleeve
24: molten metal injection flow path 25: plunger
110: die 120: die plate
122: Molten metal injection flow path 124: Molten metal injection guide
210: cavity 220: runner
230: Sleeve 231: Part 1
232: Second Part 231a: Melting Outlet
232a: molten metal inlet port 240: plunger

Claims (4)

A die having a cavity in which a cavity corresponding to a product shape is formed and a runner in which a molten metal is injected into the cavity, and a die plate holding the die and including a die plate on which a molten metal injection path is formed;
A sleeve having a space in which a molten metal flowing through the molten metal injection path is received and a molten metal outlet portion communicating with the runner; And
A plunger disposed inside the sleeve and pressing the molten metal accommodated in the space;
Low temperature chamber die casting apparatus comprising a. The method of claim 1,
The sleeve
A first part located inside the die and having a molten metal outlet communicating with the runner; And
A second part disposed inside the die plate and having a molten metal injection hole communicating with the molten metal injection channel;
Low temperature chamber die casting apparatus comprising a. The method of claim 1,
At the inlet of the molten metal injection path,
A low temperature chamber die casting apparatus comprising a molten metal injection guide guided by a molten metal injection flow path. The method of claim 1,
And a heat insulating member for preventing the temperature of the molten metal from being drastically lowered is formed outside the portion of the sleeve where the molten metal is located.

Images