JPS6364262B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology provides a method for casting a metal product by drawing molten metal into a mold, and a stable metal product by means of an apparatus directly used in the method. It belongs to a technical field that is designed to create

<Summary of the gist> The invention of this application stops relative movement between the mold and the crucible while the tip of the mold set in the mold provided in the suction casting device is immersed in the molten metal of the crucible. This invention relates to a suction casting control method in which the molten metal is solidified by suction, and then the mold and the crucible are separated from each other, and an apparatus directly used in the method. When the tip of the mold formed by this is immersed to a predetermined depth into the molten metal, the airtight frame inside the mold is depressurized by the negative pressure of the pressure reducing device via an insulating flexible hose, and the cavity inside the mold is immersed. The molten metal is aspirated and the mold is sensed by an electrical short detection device through the molten metal by an electrode immersed in the molten metal and a conductive flask of the mold, and then an actuation device incorporating a timer relay detects the short circuit. A suction casting control method in which the relative movement between the mold and the crucible is stopped, the suction and solidification time of the molten metal is measured, and the mold and the crucible are relatively separated after a set time, and a device directly used in the method This invention relates to.

<Prior art> As is well known to those skilled in the art, the conventional suction casting technology uses a decompression device to suck the molten metal in the crucible into the cavity of the mold to perform predetermined casting molding, and is not suitable for mass production. Accordingly, when casting was to be automated, the manner was as follows.

That is, the mold was immersed into the molten metal to a predetermined depth by a suction casting control device in which one of a pair of electrodes was attached near the tip of the mold, and the other electrode faced into the molten metal in the crucible. At times, one electrode contacts the liquid surface of the molten metal and short-circuits with the other electrode through the molten metal to electrically detect entry of the mold into the molten metal,
Therefore, the relative movement between the mold and the crucible is stopped, and then the pressure reducing device is activated to suck the molten metal into the cavity of the mold.

Next, after the molten metal is sucked, the molten metal in the cavity is cooled and solidified, and then the mold and the crucible are separated from each other.

<Problem to be solved by the invention> However, the tip of one of the electrodes attached near the mold is gradually melted and damaged during repeated use for casting, so the depth of the mold relative to the molten metal is unique. As a result, the amount of coagulation changes within a predetermined period of time, making it impossible to stabilize the product.

In addition, in the worst case scenario, the mold is immersed too much into the molten metal, resulting in melting damage to the casting equipment.

On the other hand, the same problem as mentioned above occurs when the molten metal adheres to the tip of the electrode, and in the worst case, the mold stops without coming into contact with the molten metal, making it impossible to cast.

To deal with this, the electrodes have to be replaced or cleaned in a short period of time, making maintenance, inspection, etc. cumbersome, and has the disadvantage of increasing maintenance costs.

<Object of the Invention> The object of the invention of this application is to solve the problems of suction casting control based on the above-mentioned prior art as a technical problem, and to uniquely create a stable product suitable for mass production. It is an object of the present invention to provide an excellent suction casting control method and apparatus that will benefit the application of casting technology in the machine manufacturing industry by reducing equipment maintenance costs.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the invention of this application, which is based on the above-mentioned claims, provides a suction casting method that is electrically connected to a mold and a crucible. a control device, wherein an electrode facing into the molten metal of the crucible is connected to a conductive flask of the mold via an electrical short detection device; It is connected to an actuating device containing a timer relay, which is connected to one lifting device between the mold and the crucible, and the mold is connected to a pressure reducing device via an insulating flexible hose. It consists of an airtight frame with an insulating flexible hose facing it, and a conductive casting mold that has the airtight frame on top and is set inside a breathable mold made of binder sand and whose upper surface of the cavity is closed with a cold metal. This is a suction casting control device consisting of a frame and a compression spring interposed between the chiller and the mold.

<Function> The mold and the crucible are moved relative to each other by the lifting device, and the mold formed by the binder sand set in the conductive flask provided at the bottom of the mold is brought into contact with the molten metal in the crucible. When the contact is made, an electrical short circuit detecting device detects contact intrusion into the molten metal of the mold by causing a short circuit through the molten metal using the conductive flask of the mold and an electrode inserted into the molten metal, and detects the electrical short circuit. The detection device sends a signal to an actuation device that has a built-in timer relay, and the actuation device temporally measures the depth of immersion of the mold into the molten metal, and after a predetermined period of time has passed, stops the lifting device and removes the molten metal. Measure the immersion time, during which time the mold cavity is depressurized by the negative pressure of the pressure reducing device through a flexible hose inserted into the closed frame provided in the flask, and the molten metal is sucked into the cavity, and a predetermined period of time elapses. After that, the lifting device is operated in reverse to separate the mold and crucible from each other, and the mold on the upper surface of the cavity is sealed by a cooling metal pressed by a compression spring, allowing the molten metal to solidify without waste. This study included the following.

<Embodiments> Next, embodiments of the invention of this application will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, reference numeral 1 denotes a suction casting device in which a mold 4 is connected to a piston 3' of a hydraulic cylinder 3 as an elevating device vertically installed below a frame 2 via an insulating spacer 5. , a pressure reducing device 6 is connected to the mold 4;
Below the crucible 7, a predetermined amount of molten metal 7' is stored and installed on a frame (not shown).

The mold 4 is constructed by attaching a conductive flask 9 to hooks 8', 8' at both lower ends of a conductive clamp arm 8 connected to the piston 3'. It is supported through portions 9', 9', and its tip 9'' is directed downward;
A short cylindrical airtight frame 11 is pressed onto the upper surface of the flange portion 9' via an O-ring 10 by another hydraulic cylinder 12 that connects the airtight frame 11 and the clamp arm 8.

On the other hand, an air permeable mold 13 made of binder sand is set in the conductive flask 9, with a predetermined cavity 14 and a sprue 15 below it formed as usual. Cavity 14
The cold metal 16 that closes the upper surface of the compression spring 1
It is attached to the airtight frame 11 on the side opposite to the hydraulic cylinder 12 via the cylinder 7 .

Further, in the pressure reducing device 6, an insulating flexible hose 18, which is integrally inserted into the airtight frame 11, has a valve 19 and is connected to a suction blower 21 via a pressure reducing chamber 20.

Reference numeral 22 denotes a suction casting control device which constitutes one of the main points of the invention of this application, and an electrical short circuit detection device 23 has a power source, a prescribed relay, etc., and has one of its lead wires facing into the molten metal 7'. A circuit connected to the electrode 24 and the other end connected to the conductive clamp arm 8 of the mold 4 is electrically connected via an actuating device 25.

The clamp arm 8 and the conductive flask 9 of the mold 4 are conductive as described above, and when the conductive flask 9 comes into contact with the molten metal 7', the electrical short circuit detection device 23 is activated. are arranged to form a closed circuit.

The actuating device 25 is provided with an appropriate timer relay 25' connected to the electrical short circuit detection device 23, and a solenoid is connected to a hydraulic switching valve (not shown) via the timer relay. The hydraulic switching valve is connected to the hydraulic cylinder 3 via a feed/discharge pipe 26.

In the above configuration, the embodiment shown in FIG. 1 is a state in which a conductive flask 9 is set in a predetermined position, and a mold 13 is previously attached to the conductive flask 9 with a cavity 14 and a sprue outside the system. 15 is formed and set inside, and then the flange portion 9' of the conductive casting flask 9 is interposed between the hook 8' of the conductive clamp arm 8 and the airtight frame 11 via the hydraulic cylinder 12. The flange portion 9' is pressed against the hook 8' via the O-ring 10 provided on the airtight frame 11 by the hydraulic cylinder 12.

Then, the joint surface between the airtight frame 11 and the flange portion 9' is sealed by the O-ring 10, and the flange portion 9' is pressed against the hook 8', so that the electrically conductive clamp arm 8 and the molded The frame 9 becomes electrically conductive.

On the other hand, the cold metal 16 in the airtight frame 11 is pressed against the mold 13 from above by the compression spring 17, thereby closing the cavity 14.

After setting the conductive casting flask 9, the actuating device 25 is turned on to operate the internal solenoid for casting work, and the piston 3' of the hydraulic cylinder 3 is caused to protrude by hydraulic pressure using the hydraulic switching valve. Then, a mold 4 consisting of a conductive clamp arm 8, a conductive flask 9, etc. is lowered relative to the crucible 7.

Then, the tip 9'' of the conductive flask 9, that is,
When the sprue 15 of the mold 13 comes into contact with the molten metal 7' of the crucible 7, the electrode 24 facing into the molten metal 7'
and the conductive casting flask 9 and the clamp arm 8
are connected via the molten metal 7', forming a closed circuit, and an output signal is transmitted from the electrical short circuit detection device 23 to the actuating device 25.

Then, the timer relay 25' of the actuating device 25 connected to the electrical short circuit detection device 23 is activated to measure the time, and after the set time has elapsed, the solenoid is activated to shut off the hydraulic switching valve, and the hydraulic cylinder 3 is lowered. to stop.

Therefore, the tip 9'' of the conductive casting flask 9 is inserted into the molten metal 7' to a preset depth (for example, the depth reduced by being sucked into the cavity 14 plus α, approximately α).
(approximately 5 to 10 mm).

Therefore, by opening the valve 19 of the pressure reducing device 6 in which the suction blower 21 is activated in advance,
The pressure inside the airtight frame 11 and the conductive flask 9 is reduced through the flexible hose 18, and the molten metal 7' is sucked into the cavity 14 from the sprue 15 by the negative pressure.

Then, a predetermined amount of the molten metal 7' is sucked, and further,
After the solidification, the timer relay 25' of the actuating device 25 measures the stop time of the hydraulic cylinder 3 and reversely operates the hydraulic switching valve, raising the mold 4 to the switching position. Bring it back.

Since the cooling metal 16 is in contact with the upper surface of the cavity 14, the molten metal 7' is solidified while preventing so-called sink marks.

In another embodiment shown in FIG. 2, a conductive sprue nozzle 27 is removably attached to the tip of the conductive flask 9 of the embodiment shown in FIG. 1 through a bolt 28. .

Therefore, in this embodiment, when the mold 4' is used repeatedly, it is only necessary to replace the sprue nozzle 27, which facilitates maintenance.

Furthermore, as shown in the embodiment of FIG. 3, the inner diameter 27'' of the sprue nozzle 27' may be made the same diameter as the runner to simplify the shaping of the sprue 15 of the mold 3.

Furthermore, in another embodiment shown in FIG. 4, the mold 4 is suspended from the upper frame 2 via an insulating spacer 5, and the crucible 7 is placed on a hydraulic cylinder 3'. The actuating device 25
Accordingly, the crucible 7 is raised to immerse the conductive flask 9 of the mold 4 into the molten metal.

It should be noted that the embodiments of the invention of this application are, of course, not limited to the above-mentioned embodiments. For example, the lifting device may be a motor or a step motor, or
The suction blower may be activated when the electrical short-circuit detection device detects molten metal, or may be activated when the flask is attached to the conductive clamp arm, or when the valve 19 is opened. Various aspects can be adopted, such as the timing of the valves may also be the same.

<Effects of the Invention> As described above, according to the invention of this application, in the suction casting control method and the apparatus directly used in the method,
Since the electrical short circuit detection device electrically detects the mold that has come into contact with the molten metal, it has the effect of directly and accurately measuring the depth of immersion of the mold into the molten metal. This has the excellent effect of uniquely guaranteeing quality stability.

In addition, since the electrical short circuit detection device uses the conductive part of the mold as one electrode, it has the excellent effect of reducing erosion of the electrode, making maintenance easier, and providing stable detection accuracy over time. be done.

Therefore, even if the mold is changed, the contact position between the mold and the molten metal is unique, and there is an advantage in terms of maintenance that there is no need to adjust the detection position.

The mold is detected by an electrical short-circuit detection device through the molten metal, which sends a signal to the operating device to control the lifting device, making it possible to fully automate the suction casting process. Excellent effects are produced.

[Brief explanation of drawings]

The drawings are explanatory diagrams of embodiments of the invention of this application. FIG. 1 is a partially sectional side view of one embodiment, FIG. 2 is a partially sectional side view of another embodiment, and FIG. 3 is a partial sectional side view of another embodiment. A sectional view of the sprue nozzle, FIG. 4 is a partially sectional side view of another embodiment. 7... Crucible, 7'... Molten metal, 4, 4'... Mold, 1, 1'... Suction casting device, 22, 22'...
Suction casting control device, 24... electrode, 8... conductive clamp arm, 23... electrical short circuit detection device, 3, 3'... lifting device, 25... actuating device, 13... breathable type , 11... Airtight frame, 9...
Conductive flask, 18...Flexible hose, 6
...Pressure reducing device, 16...Cold metal, 17...Compression spring, 25'...Timer relay.

Claims (1)

[Claims] 1. Detecting the immersion of the mold into the molten metal in the crucible,
In a suction casting control method in which the relative movement of the mold and the crucible is stopped, the molten metal is sucked and solidified, and the mold and the crucible are relatively separated, An electrical short-circuit detection device detects the immersion of an air-permeable mold molded with binder sand into the molten metal through the molten metal. A suction casting control method, characterized in that the mold is depressurized by a pressure reducing device via an insulating flexible hose to suck molten metal into a cavity, and the mold is immersed in the molten metal to a predetermined depth. 2. In a suction casting control device that is electrically connected to a mold and a crucible, an electrode facing into the molten metal of the crucible is connected to a conductive flask of the mold via an electrical short circuit detection device, and and the electrical short circuit detection device is connected to an actuation device containing a timer relay connected to one lifting device between the mold and the crucible, and the mold is connected to an insulating flexible hose. an airtight frame with the insulating flexible hose facing the airtight frame, which is connected to the decompression device through the airtight frame; 1. A suction casting control device comprising: the above-mentioned conductive flask in which a mold having a mold is set; and a compression spring interposed between the chiller and the mold.