KR20030081692A - Cooling device of low pressure type mold - Google Patents

Abstract

PURPOSE: A cooling apparatus for low pressure casting is provided to prevent high steam pressure from being applied to the pipe before cooling water reaches a metal mold to be cooled by preventing temperature increase of pipe. CONSTITUTION: In a cooling apparatus for low pressure casting for circulating cooling water to cool a metal mold(300) overheated during low pressure casting, the cooling apparatus for low pressure casting comprises a cooling water circulation path for forming metal mold cooling path and supply pipe cooling path according to internal pressure difference inside supply pipe(305); a cooling pump(310) mounted on the cooling water circulation path to vary pressure of cooling water circulated inside the supply pipe; and a water tank mounted on the cooling water circulation path so that cooling water circulated through the cooling water circulation path returns, wherein the water tank comprises first water tank(320) mounted on the metal mold cooling path; and second water tank(322) mounted on the supply pipe cooling path, wherein the cooling apparatus further comprises control valves mounted on the cooling water circulation path to form the metal mold cooling path and supply pipe cooling path as opening and closing of the control valves are being controlled, and wherein the control valves comprise first check valve(330), second check valve(332) and switch valve(334).

Description

Cooling device for low pressure casting {COOLING DEVICE OF LOW PRESSURE TYPE MOLD}

The present invention relates to low pressure casting, and more particularly, to a low pressure casting cooling device.

Typically, the workflow for making cylinder head material of a vehicle is as shown in FIG.

Referring to FIG. 1, aluminum (Al) is melted in a melting furnace to make a molten metal, and a molten metal is poured into a mold to take out a product after cooling.

At this time, the temperature of the molten metal is high at 650 ° C to 700 ° C.

At the time of casting, the temperature of the surface of the mold reaches 350 ° C to 500 ° C.

Actually, the inside of direct contact with the cooling water is calculated from 300 ℃ ~ 400 ℃ (calculated by the thermal conductivity of the mold and mold material).

Cooling is used to inject the molten metal and to shorten the molding time after pressurization.

In particular, the lower die die (low die), which is in close contact with the molten metal, has the highest temperature.

Cooling efficiency is an important part of productivity.

Effective cooling is essential to shortening the cycle time.

Water cooling aims to reduce overall production cycle time by achieving excellent cooling in a short time.

In addition, water cooling is also advantageous to the aluminum (Al) structure is excellent in quality, it is essential to produce a good quality casting by minimizing the thermal deformation of the mold.

However, water cooling is dangerous because of the explosive nature of contact with the molten metal when leaking.

Water cooling when the mold temperature is 300 ℃ instantaneously generates a water vapor pressure of 87Kg, which causes the cooling water not to flow, but rather flows backward and gives a heavy load to the pump, causing damage.

High pressure inside the pipe increases the risk of water leakage.

If water cooling is performed continuously, no steam pressure is generated.

However, continuous water cooling during low pressure casting hardens the mold before it is solidified and is not formed.

Must have constant cycle and cool down.

If the cycle time is 6 minutes, the water must be cooled in 30 seconds.

According to the prior art, as shown in Figure 2, the conventional method, when pumping in the pump 210 (Pump) the temperature of the pipe 220 (Pipe) reaches 200 ℃ and the instantaneous steam pressure at this time reaches 15Kg .

Reference numeral 230 is a water tank.

In this state, a high pressure steam pressure is applied before reaching the mold 200 to be cooled, so that the coolant does not flow properly.

In other words, the coolant does not reach the mold 200 in 30 seconds.

Use a high pressure pump to overcome this.

However, it has a fatal problem of leakage and pipe rupture.

An object of the present invention is to provide a cooling apparatus for low pressure casting that can prevent the temperature of the pipe to become high temperature and prevent the high pressure steam pressure to be applied before reaching the mold to be cooled.

1 illustrates a workflow for making a cylinder head material of a vehicle.

2 is a view showing the configuration of a low pressure casting cooling apparatus according to the prior art.

3 and 4 are views showing the configuration of a low pressure casting cooling apparatus according to an embodiment of the present invention.

In order to achieve the above object, the present invention is a low pressure casting cooling apparatus for circulating a cooling water to cool the overheated mold during low pressure casting, the mold cooling path and the supply pipe cooling path according to the internal pressure difference in the supply pipe. A circulation path of cooling water to form; A cooling pump mounted on a circulation path of the cooling water to vary a pressure of the cooling water circulating in the supply pipe; And a water tank mounted on the circulation path of the cooling water and returning the cooling water circulated through the circulation path of the cooling water.

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.

3 and 4 will be described the configuration of a low pressure casting cooling apparatus according to an embodiment of the present invention.

Embodiment of the present invention is a low pressure casting cooling apparatus for circulating the cooling water to cool the mold 300 that is overheated during low pressure casting, the circulation path of the cooling water, the cooling pump 310 (Cooling Pump), the water tank 320 322) (Water Tank).

The circulation path of the cooling water forms the mold cooling path and the supply pipe cooling path according to the internal pressure difference in the supply pipe 305 of the cooling water.

The cooling pump 310 is mounted in the circulation path of the cooling water to vary the pressure of the cooling water circulating in the supply pipe 305.

The water tanks 320 and 322 are mounted in the circulation path of the cooling water and the cooling water circulated through the circulation path of the cooling water is returned.

The water tanks 320 and 322 include a first water tank 320 mounted to the mold cooling path as shown in FIGS. 3 and 4; And a second water tank 322 mounted to the supply pipe cooling path.

Meanwhile, the embodiment of the present invention further includes control valves 330 to 334 that form a mold cooling path and a supply pipe cooling path as the opening and closing control of the cooling water is performed.

Here, the control valves 330 to 334 include a first check valve 330, a second check valve 332, and an open / close valve 334 as shown in FIGS. 3 and 4.

The first check valve 330 is mounted in a line flowing into the cooling pump 310 in the circulation path of the cooling water and opened and closed according to the pressure inside the supply pipe 305.

The second check valve 332 is mounted in a line flowing into the mold 300 in the circulation path of the coolant and opened and closed according to the pressure inside the supply pipe 305.

That is, the first and second check valves 330 and 332 maintain the closed state when the valve operating pressure is greater than the pressure output from the cooling pump 310.

On the contrary, the first and second check valves 330 and 332 remain open when the pressure output from the cooling pump 310 is greater than the valve operating pressure.

For example, when the operating pressures of the first and second check valves 330 and 332 are set to 5 kg / cm 2, the pressure of the cooling water circulating inside the supply pipe 305 is driven by the driving of the cooling pump 310. When it is 3 kg / cm 2, the first and second check valves 330 and 332 maintain the closed state.

Meanwhile, the pressure of the cooling water circulating in the supply pipe 305 is 5 kg according to the driving of the cooling pump 310 while the operating pressures of the first and second check valves 330 and 332 are set to 5 kg / cm 2. If it is more than / cm 2, the first and second check valves 330 and 332 maintain the open state.

The on / off valve 334 is mounted on a line flowing into the second water tank 322 and is opened and closed according to an on / off state.

In the state where the first and second check valves 330 and 332 are closed, the open / close valve 334 maintains the open state to form a supply pipe cooling path.

Here, the supply pipe cooling path is as follows.

Cooling pump 310 ⇒ supply pipe 305 ⇒ opening and closing valve 334 ⇒ second water tank 322

In the state in which the first and second check valves 330 and 332 are closed, the open / close valve 334 maintains the closed state to form a mold cooling path.

Here, the mold cooling path is as follows.

Cooling pump (310) ⇒ supply pipe (305) ⇒ mold (300) ⇒ first water tank (320)

As described above, the embodiment of the present invention prevents the temperature of the supply pipe 305 from becoming high by setting the pressure of the cooling water circulating through the supply pipe 305 to 3 kg / cm 2, as shown in FIG. 3. The high pressure steam pressure may be prevented from reaching the mold 300 to be cooled.

In other words, it is possible to shorten the time to reach the mold 300 to overcome the water vapor pressure to cool.

Since the pressure in the supply pipe 305 is 3 kg / cm 2, the first and second check valves 330 and 332 whose operating pressure is set to 5 kg / cm 2 are not operated.

In this case, a supply pipe cooling path for cooling the supply pipe 305 is formed.

In addition, since the cooling water is not supplied to the mold 300, the mold 300 becomes a high temperature.

As the mold 300 becomes hot, the flow of the molten metal becomes good.

When the mold 300 is cooled in this state, the opening / closing valve 334 is turned off and the pumping pressure of the cooling pump 310 is set to 5 kg / cm 2 or more.

In this case, the first and second check valves 330 and 332 are operated to open, and a mold cooling path as shown in FIG. 4 is formed.

Referring to FIG. 4, the coolant is introduced into the mold 300 through two supply pipes 305 to cool the hot mold 300.

As the cooling water comes into contact with the high-temperature mold 300, the instantaneous steam pressure is 100 kg / cm 2 or more, and the cooling water flows back.

This can be prevented by the function of the second check valve 332.

If only the instantaneous vapor pressure is overcome, the flow of cooling water is not a problem.

As described above, the embodiment of the present invention can significantly shorten the time of overcoming the high pressure steam vapor pressure.

On the other hand, the detailed description of the present invention has been described with reference to specific embodiments, of course, various modifications are possible without departing from the scope of the invention.

In the above-described embodiment, the on / off operation of the on / off valve 334 is schematically described. However, those skilled in the art may operate the on / off valve 334 on / off. OFF) switch can be designed to be operated manually, and further includes a pressure sensor for measuring the internal pressure of the supply pipe 305, automatically opening and closing valve 334 in accordance with the measured internal pressure of the supply pipe 305 Note that it is possible to automate the ON / OFF operation of the on-off valve 334 by further comprising a control unit for controlling the ON / OFF operation of the ().

Therefore, it should be noted that the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

As described above, the low pressure casting cooling apparatus according to the present invention can prevent the temperature of the pipe from becoming high temperature through the coolant circulating inside the pipe at a set pressure, and the high pressure steam pressure is reached before reaching the mold to be cooled. You can prevent getting caught.

In addition, there is an effect that the cooling water can overcome the water vapor pressure and shorten the time to reach the mold to be cooled as much as possible.

Claims (8)

In the low pressure casting cooling device for circulating the cooling water to cool the overheated mold during low pressure casting, A circulation path of the coolant forming the mold cooling path and the supply pipe cooling path according to the internal pressure difference in the supply pipe; A cooling pump mounted on a circulation path of the cooling water to vary a pressure of the cooling water circulating in the supply pipe; And a water tank mounted on the circulation path of the cooling water and returning the cooling water circulated through the circulation path of the cooling water. The method of claim 1, wherein the water tank A first water tank mounted to the mold cooling path; And a second water tank mounted on the supply pipe cooling path. The low pressure according to any one of claims 1 to 2, further comprising control valves mounted on the circulation path of the cooling water to form a mold cooling path and a supply pipe cooling path as they are controlled to open and close. Casting chiller. The method of claim 3, wherein the control valves A first check valve mounted on a line flowing into the cooling pump in the circulation path of the cooling water and opened and closed according to a pressure inside the supply pipe; A second check valve mounted on a line flowing into the mold in a circulation path of cooling water and opened and closed according to a pressure inside a supply pipe; Cooling device for low pressure casting characterized in that it comprises a switch valve mounted on the line flowing into the second water tank to open and close according to the on / off (ON / OFF) state. The low pressure casting cooling device according to claim 4, wherein the first and second check valves are kept closed when the supply pipe internal pressure is lower than or equal to the set pressure. 6. The low pressure casting cooling apparatus according to claim 5, wherein the open / close valve maintains an open state while the first and second check valves are closed to form a supply pipe cooling path. The low pressure casting cooling apparatus according to claim 4, wherein the first and second check valves are kept open when the pressure inside the supply pipe is equal to or higher than the set pressure. The low pressure casting cooling device of claim 7, wherein the opening and closing valve maintains the closed state while the first and second check valves are closed to form a mold cooling path.