JP3225988B2 - Gas processing equipment of gravity casting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas processing apparatus of a gravity casting machine for forcibly sucking and evolving a gas generated from a shell core during casting to decompose it.

[0002]

2. Description of the Related Art A conventional gas processing apparatus for a low-pressure casting machine (Japanese Utility Model Laid-Open No. 61-177761) provides a gas conduit C connected to a gas vent hole H of a mold K as shown in FIG. A pilot burner B is newly installed near the outlet of the gas conduit C, and gas generated by burning of the resin constituting the shell core is supplied through the vent hole H and the gas conduit C by the low pressure acting. The combustion was decomposed by the pilot burner B.

[0003]

The gas processing apparatus of the conventional low pressure casting machine described above requires a new pilot burner B to burn the gas generated by the shell core. There was a problem that maintenance was difficult due to the high cost.

Accordingly, the present inventors forcibly sucked the gas generated by the shell core in the casting mold by a suction device and supplied it to an existing combustion device or a waste heat stack of a molten metal melting and holding furnace for combustion decomposition. Focusing on the technical idea of the present invention, as a result of further research and development, it is said that with a simple, inexpensive and easy to maintain device, it is possible to reduce poor running and leaks and improve the working environment. The invention has been achieved which achieves the objectives.

[0005]

SUMMARY OF THE INVENTION A gas processing apparatus for a gravity casting machine according to the present invention is a gravity casting machine for performing casting using a shell core, which is connected to a hollow portion of a shell core placed in a casting mold. And a suction device communicating with the communication hole, forcibly sucking gas generated from the shell core during casting from the hollow portion through the communication hole, and the communication hole and the suction device. And a filtration device for filtering foreign substances generated from the gas sucked by the suction device, and communicating with the suction device, and burning the gas sucked and supplied by the suction device. A combustion device for decomposing or a waste heat stack of a molten metal melting and holding furnace.

[0006]

According to the gas processing apparatus of the gravity casting machine of the present invention having the above-mentioned structure, in a gravity casting machine using a shell core, a resin which is a substance produced by the shell core at the time of molten metal generates burning gas. The gas is sucked from the hollow portion of the shell core through the communication hole by the device, and supplied to the exhaust heat stack of the combustion device or the molten metal holding furnace, and the gas is burned in the exhaust heat stack of the combustion device or the molten metal holding furnace. It is to be decomposed. This makes it possible to reduce poor running and poor running and improve the working environment with a simple, inexpensive and easy-to-maintain device.

When a part of the gas sucked by the suction device is cooled, the gas becomes paste-like dust, and there is a possibility that the suction force is reduced due to clogging in the piping between the communication hole and the suction device and in the suction device. However, according to the gas processing apparatus of the gravity casting machine of the present invention having the above-described configuration, the filter device is disposed in the pipe between the communication hole and the suction device, and the foreign matter generated from the gas suctioned by the suction device is provided. Is filtered, foreign matter (paste-like tar) can be removed, and as a result, a decrease in suction force can be suppressed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

The gas processing apparatus of the gravity casting machine of the present embodiment
As shown in FIGS. 1 to 5, in a gravity casting machine 1 in which casting is performed using a shell core 11, a communication hole 13 communicating with a hollow portion 12 of the shell core 11 arranged in a casting mold 10.
And the gas generated from the shell core 11 at the time of casting is communicated with the communication hole 13 through the pipe 21.
A suction device 2 for forcibly sucking from the hollow portion 12 through the filter, a filtering device 6 for filtering foreign matter (paste-like dust) generated from the gas sucked by the suction device 2, and piping to the suction device 2. The exhaust gas chimney 31 of the furnace 3 for melting and holding the molten metal, which communicates via the suction line 31 and burns and decomposes the gas sucked and supplied by the suction device 2. The gravity casting machine 1 is composed of a rigid casting machine, for example, 2
The casting dies 10 are arranged side by side, and the molten metal in the molten metal melting and holding furnace 3 is poured by the automatic pouring machine 4 from the gate 10I of each casting die 10.

As shown in FIGS. 1 to 3, the casting mold 10 includes an upper mold 10U and a lower mold 10D. A hollow portion is formed between the upper mold 10U and the lower mold 10D. A child 11 is arranged, and this shell core 11
A hollow portion 12 is formed in the lower die 10 as shown in FIG.
Communication hole 13 reaching the outer wall at a part of the upper surface of D
Are formed. Opening 13 of communication hole 13 opening in the outer wall formed by the groove of lower mold 10D
In O, a block 13b for mounting the pipe 21 is provided.

The suction device 2 is composed of a pneumatic negative pressure generator 20. The other end of the pipe 2 having one end fixed to the block 13b is coaxially fixed to a central passage 22P formed in the central axial direction. A first air supply port 22I is formed in the outer peripheral wall, and the direction of air flow can be obtained by the flow direction changing portion 22C in the V-time cross section. The member 22 and the first member 22 are disposed to face each other, and a central passage 23P is formed coaxially with the central passage 22P in the central axial direction.
A second member 23 having a protrusion 23T formed at one end thereof and facing the direction changing portion 22C of the V-time cross section; the high-pressure air introduced from the air inlet 22I is supplied with the direction changing portion 22C of the V-time cross section; The direction is changed by flowing in a passage formed between the projection 23T and the center portion 23P, and flows into the central passage 23P from the annular opening 22A to form a flow to the right in FIG. By forming a negative pressure in the central passage 22 </ b> P in the member 22, the combustion gas generated by burning the resin in the hollow portion 12 of the shell core 11 in the casting mold 10 is transmitted through the communication hole 13 and the pipe 21. And can be forcibly sucked.

The central passage 2 of the second member 23 of the suction device 2
3P is configured to communicate with the exhaust heat chimney 31 of the molten metal holding furnace 3 by the pipe 3P.

The filtering device 6 is provided between the first filtering device 60 and the suction device 2 and the first filtering device 60 provided in the pipe 31 between the communication hole and the suction device 2. And a second filtering device 70. First filtration device 6
Numeral 0 is merely for filtering paste-like tar generated from the sucked gas.

[0014] As shown in FIG.
Is a tank 71 for storing paste-like dirt, a gas introduction hole 72 for introducing sucked gas, a gas discharge hole 73 for discharging gas, and a filter 71 for filtering paste-type dirt. A plurality of filters 74, a drain hole 75 for discharging the paste-like dust, and an alkaline decomposition solution (for example, a catalyst) for decomposing the paste-like dust
A decomposition solution tank 77 filled with
And a valve member 78 for communicating or shutting off between the tank and the decomposition solution tank 77. In addition, filter 7
There is no need to provide a plurality of 4 at all.

The molten metal melting and holding furnace 3 is constituted by a furnace main body 30 filled with molten metal, and a burner 32 constituting a combustion device which is appropriately burned in order to maintain a molten metal state is provided at an upper portion. The exhaust heat chimney 31 provided at the upper portion is always maintained at a high temperature by exhaust heat generated by combustion of the molten metal and the burner 32.

Accordingly, when the gas forcibly sucked from the shell core 11 by the suction device 2 is supplied into the exhaust heat chimney 31 through the pipe 3P, the gas can be immediately decomposed and decomposed.

In the gas processing apparatus of the gravity casting machine according to the present embodiment having the above-described structure, the molten aluminum contacts the phenol resin constituting the shell core 11 in the shell core 11 arranged in the casting mold 10 during casting. Methane, ethylene, acetylene, ammonia,
When a gas such as formaldehyde or acetaldehyde is generated, a negative pressure is formed by the flow formed by the high-pressure air in the suction device 2, and the gas is introduced into the suction device 2 through the communication hole 13 and the pipe 21 by the negative pressure. The gas is forcibly sucked and supplied together with the introduced high-pressure air into the exhaust heat stack 31 of the melting and holding furnace 3, and the exhaust gas is burned and decomposed to convert it into carbon dioxide, water and nitrogen. .

Incidentally, a part of the gas sucked by the suction device 2 is cooled in the pipe 3P between the communication hole and the suction device 2 to become a paste-like dust. And the suction force of the suction device 2 may be reduced. However,
In this embodiment, most of the paste-like tar is filtered and removed by the first filtration device 60, and the first filtration device 6 is removed.
The remainder of the tar after passing through zero is filtered and removed by the plurality of filters 74 of the second filtering device 70.

Here, the tar removed by the plurality of filters 74 is stored in a tank 75,
When a large amount of paste-like dirt accumulates inside, the valve member 78 is opened, and the decomposition solution 76 flows into the tank 71 to decompose and reduce the large amount of dirt. As a result, the decomposed resin is discharged to the outside through the drain hole 75 together with the decomposition solution 76.

The gas processing apparatus of the gravity casting machine according to the present embodiment having the above-described operation is configured such that the gas generated in the casting mold 10 during casting is forcibly sucked by the suction device 2 and the exhaust heat chimney 31 is provided.
Since it decomposes and burns in the inside of the casting mold, it has an effect of preventing a hot run and a leak due to gas generated in the casting mold and improving a working environment.

Further, the gas processing apparatus of the gravity casting machine of the present embodiment can be constructed by simply installing a pneumatic negative pressure generator 20 having a simple structure constituted by a cylindrical member as the suction device 2 and using the existing molten metal. Since it decomposes and burns in the exhaust heat chimney 31 of the melting and holding furnace 3, there is an effect that the structure is simple and the cost is low.

Further, in the gas processing apparatus of the gravity casting machine according to the present embodiment, since the suction device 2 is constituted by the pneumatic negative pressure device 20 having no movable member, the occurrence of trouble is small and the maintenance is easy. It works.

In the gas processing apparatus of the gravity casting machine of the present embodiment, since the filtration device 6 is provided in the pipe 3P between the communication hole and the suction device 2, the gas is generated from the gas sucked by the suction device 2. Can remove paste-like tar
As a result, a decrease in the suction force of the suction device 2 can be suppressed.

Further, the gas processing apparatus of the gravity casting machine according to the present embodiment has a second filtration mechanism having a mechanism for disassembling the paste-like tar in the pipe 3P between the communication hole and the suction device 2 and discharging the paste to the outside. Since the device 6 is provided, it is possible to prevent the paste-like tar from being clogged in the tank 71.

Incidentally, a negative pressure adjusting mechanism 5 for adjusting the negative pressure in the casting mold 10 as shown in FIG. 7 may be added to the apparatus of this embodiment.

As shown in FIGS. 7 and 8, the negative pressure adjusting mechanism 5 has a negative pressure adjusting opening 51 communicating with the hollow portion 12 formed in the casting mold 10, and a rectangular shape for opening and closing the negative pressure adjusting opening 51. A plate shutter 52, an air cylinder 53 that moves the shutter 52 up and down, a switching valve 55 that controls the supply of air from an air source 54, and a negative pressure in the hollow portion 12 in the casting mold 10, Pressure sensor 56 for detecting negative pressure
And a switching valve 55 based on the pressure signal from the pressure sensor 56.
And a control circuit 57 that outputs a control signal for controlling

The gas processing device of the gravity casting machine having the negative pressure adjusting mechanism 5 is provided with a pressure sensor 56 of the negative pressure adjusting mechanism 5 to control the inside of the hollow portion 12 in the shell core 11 arranged in the casting mold 10 during casting. The negative pressure in the pipe 21 corresponding to the negative pressure state is detected, and when the negative pressure detected by the pressure sensor 56 becomes, for example, 60 mmHg or more by the control circuit, the shutter 52 that controls the switching valve 55 is opened, and conversely, 60 mmHg. When it is less than the predetermined value, the shutter 52 is controlled to be closed, and the negative pressure in the casting mold 10 is controlled to be maintained at around 60 mmHg.

As described above, since the negative pressure in the casting mold 10 is controlled within a fixed width by the negative pressure adjusting mechanism 5, the same effect as that of the first embodiment is obtained, and the hollow portion 12 of the shell core 11 is provided. The effect of preventing the sand core 11 from deteriorating due to the insertion of aluminum into the shell core 11 due to the abnormal negative pressure inside the shell and preventing the sand from remaining in the product.

The above-described embodiments have been described by way of illustration, and the present invention is not limited thereto. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the drawings. Modifications and additions are possible without departing from the technical idea of the present invention.

[0030]

The gas processing apparatus of the gravity casting machine according to the present invention has the following features.
The gas generated by burning of the resin in the hollow portion of the shell core by the suction device is sucked through the communication hole and supplied to the existing combustion device or the exhaust heat stack of the molten metal melting and holding furnace to be burned and decomposed. A simple, inexpensive, and easy-to-maintain device has the effects of reducing running-out and leaking and improving the working environment.

Since foreign substances generated from the gas sucked by the suction device are filtered by the filtration device provided in the pipe between the communication hole and the suction device, the paste-like tar can be removed and the suction force can be reduced. Reduction can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a structure inside a casting mold of the present embodiment.

FIG. 3 is a cross-sectional view showing the structure inside the casting mold of the present embodiment.

FIG. 4 is an arrangement diagram showing an arrangement relationship between a casting mold and a suction device of the present embodiment.

FIG. 5 is a longitudinal sectional view showing the internal structure of the suction device.

FIG. 6 is a longitudinal sectional view showing the internal structure of a second filtration device.

FIG. 7 is a perspective view showing a negative pressure adjusting mechanism of the present embodiment.

FIG. 8 is a circuit diagram showing an air circuit of the negative pressure adjusting mechanism of the present embodiment.

FIG. 9 is a sectional view showing a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gravity casting machine 2 Suction device 3 Molten melting and holding furnace 6 Filtration device 10 Casting mold 11 Shell core 12 Hollow part 13 Communication hole 20 Pneumatic negative pressure generator 31 Exhaust heat chimney 32 Burner 3P piping

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-96362 (JP, A) JP-A-5-161957 (JP, A) JP-A-2-241463 (JP, A) JP-A 53-96 9222 (JP, A) JP-A-53-9220 (JP, A) JP-A-49-29218 (JP, A) JP-A-61-177761 (JP, U) JP-A-4-60344 (JP, U) Japanese Utility Model Showa 63-189454 (JP, U) Japanese Utility Model Showa 63-41340 (JP, U) Japanese Utility Model Showa 62-113847 (JP, U) Japanese Utility Model Showa 48-72316 (JP, U) (58) (Int.Cl. ⁷ , DB name) B22D 27/20 B22C 9/02 103 B22D 43/00 F23G 7/06 B22D 18/04

Claims (1)

(57) [Claims] 1. A gravity casting machine for performing casting using a shell core, comprising: a communication hole communicating with a hollow portion of a shell core arranged in a casting mold; A suction device for forcibly sucking the gas generated from the shell core from the hollow portion through the communication hole; and a pipe arranged between the communication hole and the suction device, which is sucked by the suction device. A filtration device that filters foreign substances generated from the collected gas; and a combustion device that communicates with the suction device and burns and decomposes the gas sucked and supplied by the suction device or a waste heat stack of a molten metal holding furnace. A gas processing apparatus for a gravity casting machine, comprising: