KR100534729B1 - Compression type apparatus of casting equipment - Google Patents

Abstract

The present invention relates to a pressurized tap apparatus for a sand casting method, which can improve shrinkage-related defects in a product part during a sand casting method and to reduce the size of the pressurizer. In the pressurized tap apparatus for a sand casting method, a pressurized chamber of a pressurized pressurizer When a certain amount of pressure medium (water, air) is put into a mold, and the molten metal is injected into the mold, the molten metal is sequentially filled into the lower chamber, the product part, and is introduced into the pressurized pressure bath in the upper portion.

Description

PRESSURE PRESSURE EQUIPMENT FOR SAND CASTING PROCESSING {COMPRESSION TYPE APPARATUS OF CASTING EQUIPMENT}

The present invention relates to a pressurized hot water supply device for sand casting method.

Referring to FIG. 1, in the present sand casting process, especially aluminum sand casting, the main casting method (mold filling method is located at the bottom of the product) is mainly used for solid filling of the molten metal, and solidification occurs during solidification of the filled molten metal. In order to prevent the occurrence of shrinkage holes (shrinkage failure) inside the product part due to shrinkage (phase transformation from liquid phase to solid phase, shrinkage due to temperature decrease), a hot water is installed at the top of the product.

When the product is solidified (non-uniform) from the liquid phase to the solid phase during solidification, the space is generated inside the solidified area by a decrease in volume, and the pressure is momentarily reduced to this area. Due to the difference in the potential energy (weight) of the molten metal is not yet solidified is moved to the shrinkage of the product portion, and serves to prevent shrinkage defects that may occur during solidification of the product portion.

Looking at the principle and operation of preventing shrinkage of the pressure with reference to Figure 2 as follows.

1) Cavity side molten metal filling ⇒ 2) Filling start solidification start ⇒ 3) Solidification shrinkage hole generation ⇒ 4) Hot water melt movement ⇒ 5) Product shrinkage hole removal ⇒ 6) Melt solidification completed

On the other hand, the technique applied practically to prevent shrinkage failure in the conventional sand casting method, as shown in Figure 3 optimization of the product part temperature distribution [temperature gradient for unidirectional solidification] by cold metal installation and product part shrinkage There are methods, such as a pressurization method, to supply the molten metal.

These two approaches are limited by the range and efficiency that can be applied by the structure of the product.

In particular, in the case of the hot water solution, the force enabling the movement of the hot water from the hot water product to the product part depends only on the atmospheric pressure and the weight of the hot water itself.

Therefore, in the case of disconnection of the path from which the molten metal can be introduced into the product part, if the flow path is long, there is a limitation in the size of the molten metal (especially the height) that can be installed due to the mold structure.

For this reason, in the sand casting method, especially in the aluminum sand casting method with a large volume change during phase transformation, shrinkage defects frequently occur, which is a problem in product quality.

For example, as shown in FIG. 4, when the flow path is disconnected, the flow path is solidified and hot water is impossible. When the flow path is long, the hot water path is long and thus the hot water is impossible due to pressure loss caused by the flow resistance. .

In addition, when the pressure of the hot water is small, its own weight pressure is low, and there is a problem of insufficient hot water pressure.

An object of the present invention to improve the shrinkage-related defects in the product portion during the sand casting method, and to provide a pressure casting apparatus for the sand casting method that can be miniaturized the hot water.

In order to achieve the above object, the present invention provides a pressurized tapping device for a sand casting method, a predetermined amount of pressurizing medium (water, air) is put into a pressurizing chamber of a pressurizing tapping machine, a mold is prepared, and a molten metal is injected into a mold. When the molten metal is sequentially filled in the lower chamber, the product portion, it is characterized in that it is introduced into the pressurized pressure in the upper.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. While many specific details, such as the following description and the annexed drawings, are shown to provide a more general understanding of the invention, these specific details are illustrated for the purpose of explanation of the invention and are not meant to limit the invention thereto. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

Referring to Figures 5 and 6 will be described the configuration of the pressure-type pressure heater 500 for the sand casting method according to an embodiment of the present invention.

6 is a view illustrating a state in which the sand pressure casting pressurizer 500 is mounted on a mold according to an embodiment of the present invention.

Embodiment of the present invention is a method for increasing the efficiency of the hot water in the method for preventing shrinkage failure of the sand casting method, the vaporization pressure of the medium (increase the volume of about 2400 times when the volume of the liquid water of the water vapor) and It is a technology for a pressurized hot water device using the principle of pressure increase according to the temperature rise of gas (PV = NRT).

In the embodiment of the present invention, in the pressure casting device for sand casting method, as shown in FIG. 6, a predetermined amount of pressure medium (water, air) is put into a pressure chamber 520 of the pressure type pressure bath 500, and a mold is formed. After manufacturing, and injecting the molten metal into the mold, the molten metal is sequentially configured to fill the lower room, the product portion and flow into the pressurized pressure bath 500 in the upper portion.

5 and 6 will be described the configuration of the pressurized pressure in accordance with an embodiment of the present invention.

The pressurized pressurizer 500 includes a case 510 which forms an outer wall, a pressurizing chamber 520, a gas outlet 530, an anti-floating plate 540, and a molten metal storage chamber 550.

The case 510 is made of a casting and generally has a thickness of 3 mm.

The pressurizing chamber 520 is formed on the upper side of the case 510 and is a portion in which the internal pressurizing medium is filled.

The medium filled in the pressure chamber 520 changes its type according to the required pressure.

The gas outlet 530 is vertically formed at the inner center of the case 510 to connect the inside of the case 510 and the outside of the case 510, and the gas generated during the filling of the melt in the case 510 is external to the case 510. To discharge.

The anti-floating plate 540 is formed to protrude in the circumferential direction from the outer wall of the case 510 and is coupled to the mold, and prevents the device from being injured by the pressure repulsive force.

The molten metal storage room 550 is formed under the case 510 to store the molten metal for supplying the product part.

Figure 7 is a view showing the operating state of the pressure type pressure in accordance with an embodiment of the present invention, the operation principle and sequence of the pressure type pressure casting for sand casting method according to an embodiment of the present invention are as follows.

① Filling molten metal and discharging internal gas ⇒ ② Filling hole molten metal ⇒ ③ Molding hole molten metal ⇒ ④ Pressurization chamber 520 pressure generation ⇒ ⑤ Pressurizing molten metal and moving shrinkage part ⇒ ⑥ Completed solidification of product

Referring to Figure 7 will be described the operation sequence and principle of the pressurized pressure device according to an embodiment of the present invention.

First, a predetermined amount of the pressurizing medium (water, air) is put into the pressurizing chamber 520 of the pressurized pressurizer 500 to produce a mold.

Then, when the molten metal is injected into the mold, the molten metal is sequentially introduced into the pressurized pressurizer 500 according to the embodiment of the present invention, which fills the lower room and the product unit.

The molten metal introduced into the pressurized pressurizer 500 sequentially fills the space inside the case 510.

At this time, the gas inside the case 510 is discharged into the atmosphere through the gas outlet 530 to remove the back pressure inside the pressurizing device, thereby smoothly filling the molten metal.

When the molten metal reaches the gas outlet 530, the molten metal of this portion solidifies rapidly to block the gas outlet 530 to prevent a loss of pressure for future pressurization.

The gas outlet 530 is blocked and the filling of the molten metal is stopped, and the pressurizing medium (water, gas) in the pressurizing chamber 520 is vaporized or expanded due to internal heat conduction.

Since the gas outlet 530 is already blocked, the pressure of the increased pressure chamber 520 acts on the molten surface inside the case 510, and the molten metal inside the case 510 is strongly moved to the contracted portion inside the product by this pressure. This prevents defective shrinkage of the product.

As described above, the pressurized tap apparatus for the sand casting method according to the present invention may improve shrinkage-related defects in the product portion and enable miniaturization of the tap.

In addition, it is possible to apply a high-efficiency small pressure can reduce the injection weight, there is an effect that can improve the degree of freedom of casting design.

1 is a view showing a configuration for a casting method for a sand casting method according to the prior art.

Figure 2 is a view showing the principle of the shrinkage prevention principle and the operating state of the prior art.

3 is a view schematically showing a configuration regarding a shrinkage failure prevention method in the sand casting method according to the prior art.

4 is a view showing a problem of the prior art pressure applicator.

5 is a view showing the configuration of a pressure-type tapping machine for the sand casting method according to an embodiment of the present invention.

Figure 6 is a view showing a state in which a pressure injector for sand casting method according to an embodiment of the present invention is mounted on the mold.

Figure 7 is a view showing the operating state of the pressure type pressure in accordance with an embodiment of the present invention.

Claims (2)

delete In the pressure type hot water device for sand casting method, A case forming an outer wall; A pressure chamber formed at an upper side of the case to fill an internal pressure medium; A gas outlet formed perpendicular to the inner center of the case and connecting the inside of the case to the outside of the case and discharging gas generated during the filling of the melt to the outside of the case; An injury prevention plate which protrudes from an outer wall of the case and is coupled to a mold and prevents device injury due to pressure repulsion; It is formed on the lower side inside the case constitutes a pressurized hot water press including a molten metal storage room for storing the molten metal for supplying the product portion, Put a certain amount of pressure medium (water, air) into the pressurizing chamber of the pressurized pressure injector to produce a mold, and injecting the molten metal into the mold, the molten metal is sequentially filled in the lower room, the product part and flowed into the pressurized pressure in the upper Pressurized hot water device for sand casting process.