KR102666180B1 - A vacuum valve block for die casting - Google Patents

Abstract

The present invention is an auxiliary equipment applied to the die casting casting method and relates to a vacuum valve block for die casting that is installed on a mold on the movable side and is used to discharge air in the mold to the outside.
The present invention relates to a vacuum valve block for die casting in which a mold side block and a movable side block are joined to form a block dividing surface, wherein a conduit for the flow of molten metal and air is recessed in the mold side block, and in the movable side block. A pipe fitting part is formed that protrudes into a shape corresponding to the pipe and is inserted into the pipe. When the mold side block and the movable side block are joined, the pipe is located inside the pipe of the mold side block at a position different from the block dividing surface. A dividing surface is formed.
According to the structure of the vacuum valve block of the present invention, the movement resistance on the external discharge path of molten metal is increased by the pipe joint provided inside the pipe, so the ejection of molten metal through the block dividing surface can be effectively prevented. have

Description

Vacuum valve block for die casting { A vacuum valve block for die casting }

The present invention is an auxiliary equipment applied to the die casting casting method and relates to a vacuum valve block for die casting that is installed on a mold on the movable side and is used to discharge air in the mold to the outside.

A variety of production-based technologies such as forging, extrusion, and casting are used in the production of parts. Among these, the casting method is widely used due to its high usability in terms of integrated moldability and mass production, and research and development to expand its utilization is continuously being conducted.

Among the methods that have improved the usability of casting, the die casting method is to inject molten metal (hereinafter referred to as 'molten metal') at high pressure into a mold with a cavity of a complex and precise shape to create a casting with high strength and a beautiful surface in a short period of time. It has the feature of being able to be produced in large quantities.

However, in the case of the die casting method, which involves molding by injecting molten raw materials into the mold at high speed and pressure, air is mixed into the casting during the injection and filling process, and products manufactured without removing this air bubbles during post-processing such as heat treatment. It has the problem of expanding and causing product defects.

Therefore, in order to increase the usability of the die casting method, entrained air is discharged using a vacuum valve.

The vacuum valve typically includes a floating piston that detects the inflow of the casting and a valve piston that controls whether air is discharged in conjunction with the floating piston, and is described in Korean Patent Publication No. 10-0306452 as “for ventilation of die casting molds.” “Valve assembly” is posted.

The valve assembly published in Registered Patent Publication No. 0306452 includes a floating piston whose movement is guided by a push pin and placed in a groove of the movable block, a valve piston and an operating piston disposed at a certain distance from the floating piston but interlocked with the floating piston. In addition, an air discharge hole is provided on the upper surface of the housing block and the flow path is opened and closed by a valve piston.

The housing block is fixedly coupled to one surface of the movable block, and when the housing block with the casting flow path formed in the coupled state is combined with the die casting mold, each end of the valve piston and the floating piston is cast through the through hole formed in the casting flow path. It is exposed inside the euro. At this time, the casting flow path and the air discharge hole are communicated with each other by the floating piston, and when the vacuum pump connected to the air discharge hole operates, the casting flow path forms a vacuum state.

In addition, the mold space of the die casting mold to which the housing block is combined is also in communication with the casting flow path to form a vacuum state, and while the vacuum is maintained, the molten metal is injected into the mold space of the die casting mold.

The molten metal injected as described above fills the mold space of the die casting mold and then flows into the housing block through the inlet, filling the lower space with casting oil and slowly moving upward.

The molten metal moving upward as described above fills the casting passage where the floating piston is located, and the floating piston presses the elastic member by the pressure of the filled casting and gradually retreats.

At this time, the valve piston and the operating piston linked to the floating piston also retreat, and as the valve piston retreats, the casting flow path and the air discharge hole that were in communication with each other are disconnected.

Accordingly, the air discharge by the vacuum pump is stopped, and then the movable block and the housing block are separated from the mold unit, and the work is completed by removing the molded product for which the molding work has been completed from the die casting mold and the housing block.

However, the following problems appear in the above-described prior art.

First, in vacuum valves according to the prior art, casting fins are frequently formed by ejection of molten metal.

The casting fin (burr) is a plate-shaped protrusion of uneven thickness and is generated at the dividing surface or connection part of the mold, the core print, or the cross section where two types of molds meet. In Figure 1, a vacuum according to the prior art is shown. A photo showing the casting fin formed by the valve is shown.

The shown casting fin 20 is formed by ejecting molten metal through the split surfaces of vacuum valve blocks that are joined together. As the pressure of the molten metal injected into the casting passage increases, the molten metal rises to the upper side of the casting passage. The rising pressure of the molten metal forms a gap between the divided surfaces of the vacuum valve block and is ejected to the outside.

The casting fin 20 formed as described above is formed in a plate shape with a thin thickness and forms a relatively large area, which promotes cooling and causes cracks in the product or quality deterioration such as erosion and deterioration of sealability. Shiki has a problem.

Meanwhile, Figure 2 shows a photograph showing the vacuum valve block being eroded by molten metal in a vacuum valve structure according to the prior art.

The shown erosion portion 40 is where the floating piston is located in the mold-side valve block constituting the vacuum valve block, and the high-temperature, high-pressure molten metal injected through the casting inlet forms the flow path of the piston before pushing the floating piston. It first flows into the entrance to the hall.

Therefore, the high-temperature, high-pressure molten metal first comes into contact with the lower part of the hole entrance, forming an eroded part 40 such as a dent or crack. This eroded part 40 causes an operation failure of the floating piston and causes the use of a vacuum valve. It has the problem of shortening its lifespan.

KR 10-0306452 B1 KR 10-2124618 B1

The purpose of the present invention is to provide a vacuum valve for die casting that can prevent molten metal flowing into the casting inlet pipe from being ejected through the divided surface of the vacuum valve block by forming the dividing surface of the vacuum valve block and the dividing surface of the casting inlet pipe at different positions. It provides blocks.

Another object of the present invention is to provide a vacuum valve block for die casting that can improve the service life of the vacuum valve by improving the molten metal inflow path of the vacuum valve block.

The present invention relates to a vacuum valve block for die casting in which a mold side block and a movable side block are joined to form a block dividing surface, wherein a conduit for the flow of molten metal and air is recessed in the mold side block, and in the movable side block. A pipe fitting part is formed that protrudes into a shape corresponding to the pipe and is inserted into the pipe. When the mold side block and the movable side block are joined, the pipe is located inside the pipe of the mold side block at a position different from the block dividing surface. It is characterized by the formation of a dividing surface.

A first pipe connected to the molten metal inlet, a second pipe formed in a segmented state from the first pipe and connected to the air outlet are formed in the mold side block, and one side of the first pipe is formed in the movable block. A third pipe connecting one side of the second pipe is further formed so that the molten metal flowing in through the molten metal inlet is transported via the movable block.

The pipe engagement portion formed in the movable block is characterized in that it corresponds to at least one of the first pipe and the second pipe.

The pipe engagement portion formed in the movable block is divided into a first engagement portion corresponding to the first pipe and a second engagement portion corresponding to the second pipe, and the third pipe is divided into a first engagement portion and a second engagement portion. It is characterized by a depression being formed between the engaging parts.

The protruding length of the pipe fitting portion is characterized in that it is less than 20 mm.

In the vacuum valve block for die casting according to the present invention, the pipe through which molten metal and air are transported is formed by joining the movable side block and the mold side block, and the upper side of the pipe recessed in the mold side block is formed by protruding from the movable side block. It is designed to provide additional shielding.

Therefore, as the pipe fitting part is located inside the pipe, a double-sided joint is formed on the side and plane of the pipe, and the pipe dividing surface is formed in a position different from the block dividing surface formed by the mold side molding surface and the movable side molding surface. You can.

In order for the molten metal flowing into the pipe through the pipe dividing surface formed as described above to be ejected through the block dividing surface, a gap in the vertical direction formed by the pipe engaging portion and the inner surface of the pipe and the block dividing surface must be formed. It must pass through all gaps in the horizontal direction, and as the pressure of the molten metal, which has straight-flowing properties, is weakened in the process of changing direction horizontally and vertically, the ejection of the molten metal through the block dividing surface can be effectively prevented.

In addition, in the present invention, the pipe through which molten metal and air are transported is divided into a first pipe and a second pipe formed on the mold side block, and a third pipe formed on the movable side block, and the first pipe and the second pipe are separated from each other. In this state, it is communicated through the third pipe.

In other words, the present invention forms a pipe so that the molten metal injected into the molten metal inlet passes from the mold side block to the movable side block and then flows into the center of the molten metal detection area, thereby preventing erosion of the mold side block due to high temperature and high pressure molten metal. You can.

In addition, as a cooling channel is formed in the movable side block to intersect the third pipe, the erosion prevention effect of the mold side block can be further improved.

Figure 1 is a photograph showing a casting fin formed by a vacuum valve according to the prior art.
Figure 2 is a photograph showing the vacuum valve being eroded by molten metal in a vacuum valve structure according to the prior art.
Figure 3 is a view showing an example of a mold side block constituting a vacuum valve block for die casting according to the present invention.
Figure 4 is a view showing an example of a movable side block constituting a vacuum valve block for die casting according to the present invention.
5 to 7 are diagrams for explaining the pipe formation structure of the vacuum valve block for die casting according to the present invention.
Figure 8 is a diagram showing the movement path of molten metal by the vacuum valve block for die casting according to the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. In adding reference numerals to components in each drawing, identical components are given the same reference numerals as much as possible even if they are shown in different drawings. In addition, in the description of the embodiment, if it is determined that specific descriptions of related known configurations or functions, such as floating piston or valve piston, interfere with the understanding of the embodiment of the present invention, the description is simplified or omitted, and any components are omitted. When a component is described as being “provided” on one side of another component or as being “formed” with another component, that component may be provided or formed directly on one side of the other component, but each component It should be understood that another component may be “equipped” between elements, or may be “formed” together with another component.

Figure 3 shows an example of a mold side block constituting a vacuum valve block for die casting according to the present invention, and Figure 4 shows an embodiment of a movable side block constituting a vacuum valve block for die casting according to the present invention. A drawing showing an example is shown.

In addition, Figures 5 to 7 show drawings to explain the pipe formation structure of the vacuum valve block for die casting according to the present invention, and Figure 8 shows the movement path of molten metal by the vacuum valve block for die casting according to the present invention. A drawing for is shown.

First, referring to FIG. 3, the mold side block 200 according to the present invention has a mold side molding surface 212, which is one side of the square-shaped mold side block body 210, for forming a movement path for molten metal and air. A pipe is formed, and the pipe is divided into a first pipe 240 and a second pipe 260 that are segmented from each other.

In this embodiment, the first pipe 240 is in communication with the molten metal inlet 220 and provides a movement path so that the incoming molten metal meets at the center after branching to the left and right, but there is no other discharge path in the horizontal direction. It forms a closed pathway.

Meanwhile, the second pipe 260 is formed at a position spaced apart from the first pipe 240 and communicates with the air discharge hole to provide an discharge path for the inflowing air, and reduces the fluidity of the molten metal while forming the air discharge hole. It can be selectively shielded to prevent discharge of molten metal through the air discharge hole.

For this purpose, in this embodiment, the second pipe 260 includes a molten metal detection area 250 for detecting the load of the incoming molten metal, a flow stabilization area 230 for reducing the fluidity of the incoming molten metal, and the molten metal. It includes an intake blocking area 270 that discharges incoming air and prevents discharge of molten metal.

The molten metal detection area 250 is a place where molten metal is first received in the second pipe 260, and the molten metal flows in through the third pipe 440, which will be explained below.

Although not shown, the molten metal detection area 250 is provided with a floating piston that moves by pressing force according to the volume of incoming molten metal.

The floating piston maintains a stationary position within the molten metal detection area 250 by an elastic support force greater than a certain level by an elastic member, and moves in one direction when a pressing force greater than the elastic support force is applied.

The floating piston moved as described above is connected to a valve piston (not shown) provided in the intake blocking area 270 and a connector (not shown).

The valve piston is provided in the intake blocking area 270 connected to the air discharge hole to open and close the air discharge hole. The air discharge hole is kept open while molten metal is flowing in to maintain the vacuum state of the connected pipe. do.

And, while the above-mentioned vacuum state is maintained, when the inflow amount of molten metal increases and the floating piston moves, the valve piston moves together with the floating piston to shield the air discharge hole.

The flow stabilization area 230 is formed between the molten metal detection area 250 and the inlet blocking area 270 with the same function as above, so that the molten metal flowing into the molten metal detection area 250 moves to the inlet blocking area 270. This is to reduce the speed of molten metal in the process, and is formed to have a predetermined volume on both left and right sides of the molten metal detection area 250.

That is, the flow stabilization area 230 accommodates a certain amount of molten metal flowing into the molten metal detection area 250 after it diverges to the left and right, thereby reducing the flow speed by reducing the straightness of the molten metal.

Meanwhile, the second pipe 260 including the flow stabilization area 230, the melt detection area 250, and the inlet blocking area 270 is segmented from the first pipe 240 as described above. It is connected by 3 pipes (440).

Referring to FIG. 4, in the movable side block 400 according to the present invention, a pipe engaging portion 420 is formed protruding from the movable side engaging surface 412, which is one surface of the square-shaped movable side block body 410, and The third pipe 440 is recessed between the pipe engaging portions 420.

The third pipe 440 is formed when the mold side molding surface 212 and the movable side molding surface 412 correspond and the mold side block 200 and the movable side block 400 are molded, the first pipe 240 and the second pipe 260 are connected to form a movement path for the molten metal.

That is, the present invention connects the first pipe 240 and the second pipe 260, which are closed paths in the horizontal direction in the mold side block 200, to the third pipe 440 formed in the movable side block 400. By using a bridge, the movement path of the molten metal continues in the horizontal and vertical directions and communicates. Therefore, the direction of movement of the molten metal may be changed while passing through the third pipe 440, thereby reducing the speed of the molten metal.

Additionally, the end of the third pipe 440 that communicates with the second pipe 260 is positioned toward the central portion of the floating piston accommodated in the molten metal detection area 250. Accordingly, the molten metal with a reduced transfer speed does not directly contact the molten metal detection area 250, but is filled after contacting the floating piston, thereby preventing the molten metal detection area 250 from being eroded by high-temperature, high-pressure molten metal.

Meanwhile, the pipe engaging portion 420 is formed to protrude into a shape corresponding to the pipe formed in the mold side block 200 and is inserted into the pipe to improve the sealing force of the pipe.

Referring to FIGS. 5 to 7 for detailed description, the pipe engaging portion 420 is formed to protrude into a shape corresponding to one or more of the first pipe 240 and the second pipe 260 and forms a mold-side block 200. ) and the movable side block 400 are inserted into the corresponding pipe to form a pipe dividing surface 340 in a different position from the block dividing surface 320.

That is, the block dividing surface 320 is a dividing surface formed by the mold side block body 210 and the movable side block body 410, and the mold side molding surface 212 and the movable side molding surface 412 are contact surfaces. It can be defined as:

In addition, the pipe dividing surface 340 is a dividing surface formed inside the pipe at a lower position than the block dividing surface 320, and can prevent molten metal inside the pipe from being ejected into the block dividing surface 320.

Referring to FIG. 7 for a more detailed description, in a state where the pipes 240 and 260 are formed in a negative manner in the mold side block 200, a pipe engaging portion 420 is formed in a positive way in the movable side block 400. When inserted, the upper side of the pipe is shielded by the pipe engaging portion 420, so that the sealing force of the pipe (240, 260) can be further improved.

That is, when molten metal is discharged through the block dividing surface 320 as the pipe engaging portion 420 protrudes into the inside of the pipes 240 and 260 by a predetermined depth, the molten metal is on the inner surface of the pipes 240 and 260. After passing through the gap between the sides of the pipe fitting portion 420, it can be discharged along the block dividing surface 320.

However, it is difficult for molten metal, which has a straight path, to pass through the gap of a relatively small area, and even if the molten metal moves upward through the gap, the direction is changed back to the horizontal direction, thereby reducing the mobility of the molten metal. As this rapidly decreases, discharge of molten metal through the block dividing surface 320 can be prevented.

Meanwhile, for the above function, the protrusion length “L” of the pipe engaging portion 420 has a range of less than 20 mm.

As described above, the pipe engaging portion 420 is inserted into the pipes 240 and 260 of the mold-side block body 210. When the protrusion length “L” exceeds 20 mm, the pipe 240 , 260) creates difficulties in design.

That is, the limited internal space of the mold-side block body 210 includes design elements such as a floating piston, a valve piston, and a cooling channel, and stable operation and cooling efficiency are achieved without interference with such design elements. Since it must be reflected in the design, the range of the protrusion length “L” may be limited to the above range.

The pipe engaging portion 420 having the same function as described above includes a first engaging portion 422 corresponding to the first pipe 240 formed in the mold side block 200, and a second engaging portion corresponding to the second pipe 260. It can function in a form that includes all of the engaging portions 424, or in a form in which only one of the first engaging portion 422 and the second engaging portion 424 is formed, but has improved sealing performance. For this purpose, it would be desirable for both the first engaging portion 422 and the second engaging portion 424 to be formed.

Meanwhile, according to the vacuum valve block for die casting according to the present invention, as shown in FIG. 8, the movement path of molten metal from the first pipe 240 to the second pipe 260 via the third pipe 440 (H) is formed.

In addition, as described above, the molten metal moving along the movement path (H) moves from the first pipe 240 to the third pipe 440, causing a decrease in speed and temperature, as well as guiding the movement position of the molten metal. Erosion of the molten metal detection area 250 can be prevented, and in addition, a cooling channel passing around the third pipe 440 may be further provided inside the movable side block 400.

Therefore, by lowering the temperature of the molten metal transported along the third pipe 440 by the cooling channel, the effect of preventing erosion of the molten metal detection area 250 can be further improved, and the vacuum valve block with this structure can be further improved. This applied vacuum valve can be expected to have an improved service life.

200.......... Mold side block 210............ Mold side block body
212............. Mold side joint surface 220............. Molten metal inlet
230......... Flow stabilization area 240............ First conduit
250............. Molten metal detection area 260............. Second pipe
270......... Inlet blocking area 320............ Block dividing surface
340......... Pipe dividing surface 400............ Movable side block
410.......... Movable side block body 412............ Movable side mating surface
420......... Pipe connection part 422............. First connection part
424.........2nd joint 440.........3rd conduit
H............ Molten metal movement path

Claims (5)

In the vacuum valve block for die casting, where the mold side block and the movable side block are joined to form a block dividing surface where the two blocks are in contact,
A pipe for the flow of molten metal and air is recessed in the mold side block,
The movable side block is formed with a pipe engaging portion that protrudes into a shape corresponding to the pipe and is inserted into the pipe,
When the mold side block and the movable side block are joined, a pipe dividing surface is formed inside the pipe of the mold side block at a position different from the block dividing surface,
The mold side block is formed with a first pipe connected to the molten metal inlet, a second pipe formed in a segmented state from the first pipe and connected to the air outlet,
A third pipe connecting one side of the first pipe and one side of the second pipe is further formed in the movable side block, so that the molten metal flowing in through the molten metal inlet is transported via the movable side block. Vacuum valve block.
According to claim 1,
A vacuum valve block for die casting, characterized in that the pipe engagement portion formed in the movable block corresponds to at least one of the first pipe and the second pipe.
According to clause 2,
The pipe connection part formed in the movable block,
A first engagement portion corresponding to the first pipe,
It is divided into a second connection section corresponding to the second pipe,
A vacuum valve block for die casting, wherein the third pipe is recessed between the first engaging portion and the second engaging portion.
According to claim 1,
Vacuum valve block for die casting, characterized in that the protruding length of the pipe fitting portion is less than 20 mm.
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