JP4125002B2 - Mg casting method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an Mg casting method and apparatus.
[0002]
[Prior art]
Conventionally, gold materials, palladium alloys, and the like have been used for dental materials such as metal floors and abutment teeth, but these are generally expensive and have a great financial burden on patients.
[0003]
By the way, magnesium and magnesium alloys (hereinafter collectively referred to as Mg) are said to be a metal resource that exists in large quantities in nature and can be obtained at low cost. Have been used.
[0004]
As a typical example of use, Mg is castable and lightweight, and is mass-produced, for example, in parts for automobiles and portable computer cases.
[0005]
[Problems to be solved by the invention]
The inventor of the present invention provides Mg to patients at low cost by casting dental materials or medical materials such as artificial joints because Mg is an essential metal for the human body and has excellent biocompatibility. As a result, the present invention has been devised.
[0006]
Therefore, an object of the present invention is to provide an Mg casting method and apparatus suitable for casting a relatively small Mg molded product.
[0007]
Another object of the present invention is to provide an Mg casting method and apparatus suitable for producing a relatively small single product by casting.
[0008]
[Means for Solving the Problems]
Such a technical problem is, according to one aspect of the present invention,
Prepare a crucible without heating means,
When the crucible heated by an external heating means is placed on the mold placed in the Mg casting apparatus, and the Mg lump charged in the heated crucible is melted, the pouring of the bottom of the crucible This is achieved by providing an Mg casting method characterized by pouring molten metal from a hole into a mold.
[0009]
Mg has a relatively low melting point of about 650 ° C. For example, in the case of dental materials, a relatively small amount of Mg is sufficient to make one product. From this, a crucible heated by an external heating means is prepared, and the Mg lump can be dissolved in a relatively short time by introducing the Mg lump into the crucible.
[0010]
This means that the crucible at the stage of melting the Mg lump is to melt the Mg lump using the thermal energy held by itself. For example, a heating means is prepared in the Mg casting apparatus, and this heating means Therefore, it is possible to eliminate the risk of oxidative combustion during Mg dissolution, which becomes a problem when the crucible is heated or the Mg lump in the crucible is heated to melt the Mg lump.
[0011]
Therefore, as in the present invention, the problem of oxidative combustion at the time of Mg dissolution can be solved by dissolving the Mg mass using the thermal energy possessed by the crucible heated by the external heating means .
[0012]
It is known that most of the gas contained in the molten Mg is hydrogen gas. However, in order to degas this hydrogen, it is preferable to perform pouring in an inert gas atmosphere. Moreover, if necessary, it is preferable to carry out in an inert gas atmosphere when dissolving the Mg lump.
[0013]
The timing for putting the Mg lump into the heated crucible may be before the crucible is set in the Mg casting apparatus, or after that. If the Mg lump is introduced after setting the crucible in the Mg casting apparatus, it will be easy to make the inside of the Mg casting apparatus an inert gas atmosphere thereafter.
[0014]
As a preferred embodiment of the present invention, a relatively small-diameter through-hole or a pouring hole is provided at the bottom of the crucible, and an inert gas is introduced into the crucible when pouring, and molten Mg is poured. It may be sprayed into the mold through the holes.
[0015]
In order to improve the hot water in the mold, it is preferable to suck the cavity of the mold when Mg is poured into the mold.
[0016]
According to another aspect of the invention,
A bottomed body that opens upward;
An openable / closable lid that closes the opening of the body;
A gas guide cylinder hanging downward from the lid;
Elevating means arranged at the bottom of the main body for elevating the mold;
An inert gas supply means for supplying an inert gas into the gas guiding cylinder;
Suction means for sucking the cavity of the mold ;
Having a crucible without heating means ,
When the crucible heated by the external heating means is arranged on the mold at an interval and the Mg in the heated crucible can be poured, the mold is raised by the elevating means. The crucible is engaged by the inert gas supplied from the inert gas supply means into the gas guide cylinder by engaging the mold and further engaging the mold and the gas guide cylinder. Mg casting is characterized in that Mg in the mold is poured into the mold through a pouring hole at the bottom of the crucible, and the cavity of the mold is sucked by the suction means during the pouring. An apparatus is provided.
[0017]
In the Mg casting apparatus, the pouring hole at the bottom of the crucible should have a relatively small diameter, and thereby, the inert gas introduced into the gas induction cylinder during pouring causes the inside of the crucible to The molten Mg can be vigorously filled into the mold through the pouring hole at the bottom of the crucible.
[0018]
The above object, other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention.
[0019]
【Example】
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an Mg casting apparatus according to an embodiment. The Mg casting apparatus 1 has a bottomed apparatus main body 2 having a substantially cylindrical inner space opened upward, and a lid 3 attached to the opening end of the main body 2 via a hinge 3. By closing the lid 3 and rotating the screw lock 5, the inside of the apparatus can be kept airtight.
[0020]
A base piston 6 is fitted into the lower end of the apparatus main body 2, and the base piston 6 can move up and down along the inner wall surface of the main body 2. On the inner wall surface of the main body 2, an inner peripheral ring portion 7 projecting radially inward is formed at an intermediate portion in the vertical direction, and compression is performed between the inner peripheral ring portion 7 and the base piston 6 below the inner peripheral ring portion 7. A spring 8 is interposed.
[0021]
The lid 3 has a viewing window 9 including a pressure-resistant and heat-resistant glass 8 at the center thereof. The lid 3 is also provided with a gas guiding cylinder 10 in alignment with the sighting window 9 below the sighting window 9, and a circle extending outwardly at the lower end of the gas guiding cylinder 10. A circumferential flange 11 is formed.
[0022]
The lid 3 is formed with a first internal passage 12 having an opening 12a between the viewing window 9 and the gas guiding cylinder 10, while the main body 2 has a second end opened at its upper end surface. The second internal passage 13 communicates with an Ar gas introduction port 14 opened on the upper side surface of the main body 2. When the lid 3 is sealed, the first internal passage 12 and the second internal passage 13 communicate with each other to form an Ar gas introduction passage.
[0023]
The main body 2 has a third internal passage 15 having one end opened at a position corresponding to the lower end portion thereof, that is, the base piston 6, and the third internal passage 15 is opened to the lower side surface of the main body 2. Communicating with
[0024]
The main body 2 also has a fourth internal passage 17 having one end opened at the center of the bottom, and the fourth internal passage 17 communicates with a pressurized gas introduction port 18 opened at the lower end side surface of the main body 2. is doing.
[0025]
A circumferential recess 19 is formed on the side surface of the base piston 6, and the circumferential recess 19 communicates with a discharge port 21 opened at the center of the upper surface of the base piston 6 via an internal passage 20.
[0026]
The Ar gas introduction port 14 is connected to an Ar gas source 22 via a first external pipe 23, and the first external pipe 23 includes a flow rate adjustment valve 24, a first on-off valve 25, and the like. A pressure gauge 26 is interposed. Although both the flow rate adjusting valve 24 and the on-off valve 25 may be manually operated or electrically operated, in this embodiment, the flow rate adjusting valve 24 is manually operated and the on-off valve 25 is electrically operated using, for example, a solenoid. It consists of a valve. The on-off valve 25 is opened and closed by operating the Ar filling switch 27.
[0027]
The suction port 16 is connected to a vacuum source 28 such as a suction pump via a second external pipe 29, and a second on-off valve 30 is interposed in the second external pipe 29. Yes. The second on-off valve 30 may be manually operated, but is electrically operated in this embodiment, and the second on-off valve 30 is opened and closed by operating the suction switch 31.
[0028]
The pressurized gas introduction port 18 is connected to the pressurized gas source 32 via a third external pipe 33, and a third on-off valve 34 having a check valve function is connected to the external pipe 33. Is intervening. The third on-off valve 34 may be manually operated, but is electrically operated in this embodiment and is opened and closed by operating the set switch 35. When the third on-off valve 34 is opened, the flow of gas from the pressurized gas source 32 toward the pressurized gas introduction port 18 is allowed, but the reverse flow is prohibited.
[0029]
In the Mg casting apparatus 1, a molding surrounded by a cylindrical body 50 made of a porous heat-resistant investment material (for example, gypsum-based investment material) by a lost wax method well known in the field of dental technology is formed on a base piston 6. A mold 51 is disposed, and an intermediate ring 52 is disposed thereon.
[0030]
The intermediate ring 52 has a size to be seated on a circumferential ring portion 7 formed at an intermediate portion in the height direction of the main body 2. The intermediate ring 52 has a central opening 53 having a relatively large diameter at the center thereof and a plurality of communication holes 54 having a relatively small diameter outward in the radial direction from the central opening 53. The plurality of small diameter communication holes 54 are preferably arranged at equal intervals in the circumferential direction.
[0031]
The intermediate ring 52 is also a member that provides a seat for the Mg melting crucible 55, and a circular recess 56 is formed around the central opening 53 in the central portion of the upper surface of the intermediate ring 52. The side wall is composed of an inclined surface that gradually increases in diameter toward the upper side.
[0032]
The crucible 55 is made of a bottomed cylindrical body opened upward, and is made of a material or metal excellent in heat resistance, such as stainless steel. The outer diameter of the crucible 55 is substantially equal to the diameter of the bottom portion of the circular recess 56 of the intermediate ring 52.
[0033]
The crucible 55 has an injection pouring hole 57 having a relatively small diameter extending in the vertical direction at the center of the bottom wall, and the inner bottom surface 58 is configured by a tapered surface inclined in a funnel shape toward the central injection pouring hole 57. Has been.
[0034]
Next, the Mg casting method including the operation method of the Mg casting apparatus 1 will be described. The exemplary Mg castings are aimed at casting dental materials such as inlays, crowns, abutment teeth, front crowns, metal floors, cast bars, cast clasps, but relatively small precision similar to these dental materials The present invention can also be applied to castings, dental implants such as artificial tooth roots, surgical implants such as artificial joints, bone fixation devices (plates, pins, screws, wires, etc.), internal nails, and stents.
[0035]
FIG. 2 shows a state in which the mold 51 and the intermediate ring 52 are installed in the Mg casting apparatus 1. In this state, the base piston 6 is located at the lower end position, and therefore, the upper surface of the mold 51 and the lower surface of the intermediate ring 52 are in a separated state.
[0036]
During this preparation step or after this preparation step, the crucible 55 is heated using an external heating means such as a microwave oven 59, for example. The heating of the crucible 55 is continued until the crucible 55 reaches about 1100 ° C., for example. This temperature is not particularly limited. As will be described later, the temperature may be any temperature that is convenient for dissolving Mg in the heated crucible 55 within an appropriate time. This is the size of the crucible 55 (heat capacity) and the size of the target Mg lump. What is necessary is just to determine an optimal value by it.
[0037]
Next, as shown in FIG. 3, the heated crucible 55 is inserted into the Mg casting apparatus 1 and placed on the intermediate ring 52.
[0038]
Next, as shown in FIG. 4, the Mg lump 60 is put into the crucible 55 in the Mg casting apparatus 1. Next, the lid 3 is closed, and the main body 3 is sealed with the lid 3 using the screw lock 5.
[0039]
Next, the Ar gas filling switch 27 and the suction switch 31 are operated to open the first and second on-off valves 25 and 30, and the Ar gas that is an inert gas is filled while suctioning from below the Mg casting apparatus 1. . The Ar gas introduced from the upper part of the Mg casting apparatus 1 passes through the space above the intermediate ring 52 where the crucible 55 is located, through the small-diameter through hole 54 of the intermediate ring 52, as indicated by the arrow in FIG. After entering the lower space where the mold 51 exists and entering the cavity C of the mold 51, it passes through the mold 51 and is sucked to the outside through the internal passage 20 of the base piston 6 from its lower end surface.
[0040]
During this time, the operator observes the state of the Mg lump 60 in the crucible 55 through the observation window 9. When the Mg mass 60 is completely dissolved, the set switch 35 is operated to open the third on-off valve 34 and introduce the pressurized gas from the pressurized gas source 32 into the lower space of the base piston 6 as shown in FIG. To do. As a result, the base piston 6 is biased upward, and the base piston 6 rises against the spring force of the compression spring 8.
[0041]
The ascending base piston 6 pushes up the mold 51, pushes the upper end surface of the mold 51 against the intermediate ring 52, further pushes up the intermediate ring 52, and finally, over the crucible 55. The end surface comes into pressure contact with the lower end flange 11 of the gas guiding cylinder 10 of the lid 3.
[0042]
In FIG. 5, the mold 51, the intermediate ring 52, the crucible 55, and the gas guide cylinder 10 are integrated by the upward movement of the base piston 6, and the mold 51 is passed through the injection hole 57 of the crucible 55 from the gas guide cylinder 10. This shows a state in which one sealed passage reaching the cavity C is formed. In the state of FIG. 5, Ar gas passes through the gas guiding cylinder 10 and enters the crucible 55 to push down the molten metal. The molten metal in the crucible 55 is injected into the cavity C of the mold 51 through the injection pouring hole 57 of the crucible 55. The cavity C is in a state of being sucked by the vacuum source 28, so that the molten metal that has entered the cavity C is quickly filled to the details of the cavity C.
[0043]
When the above steps are completed, all the switches 27, 31, and 35 are turned OFF to close all the on-off valves, and then the lid 3 is opened, and the crucible 55, the intermediate ring 52, and the mold 51 are taken out.
[0044]
As can be understood from the above description, the Mg casting apparatus 1 forms two modes depending on whether the base piston 6 is in the lowered position or the raised position. That is, when the base piston 6 is in the lowered position, as shown in FIG. 4, the Ar gas introduced from the upper end in the apparatus, that is, from the vicinity of the central viewing window 9 of the lid 3 passes through the gas guiding cylinder 10, The gas guide tube 10 enters the upper space of the intermediate ring 52 through a gap between the lower end of the gas guiding cylinder 10 and the upper end of the crucible 55, and further flows into the lower space of the intermediate ring 52 through the communication hole 54 of the intermediate ring 52. Thus, the first mode of entering the cavity C of the mold 51 is taken.
[0045]
As can be understood by those skilled in the art, the base piston 6 substantially constitutes a gas-type jack, that is, an elevating means. However, a liquid-type jack is formed by filling a liquid under the base piston 6. You may do it. That is, the base piston 6 constitutes a gas type or liquid type or fluid type jack. As a modification, instead of the base piston 6, a mechanical lifting means such as a pantograph jack or a screw screw jack may be used.
[0046]
On the other hand, when the base piston 6 is in the raised position, as shown in FIG. 5, the Ar gas introduced into the upper end of the apparatus increases the pressure in the crucible 55 through the gas guiding cylinder 10, and the crucible 55 A second mode is adopted in which the molten metal inside is pushed down and injected into the cavity C from the ejection hole 57.
[0047]
In the above embodiment, after the heated crucible 55 is set in the apparatus, the Mg lump is charged into the crucible 55. However, the Mg lump is charged into the heated crucible 55 before being set in the apparatus. Thereafter, the crucible 55 containing the Mg block may be set in the apparatus (FIG. 6).
[0048]
In addition, as shown in FIG. 7, the inert gas may be blown into the cavity C at any time prior to pouring. For example, as soon as the mold 51 and the intermediate ring 52 are set in the apparatus, the lid 3 is closed, and Ar gas is introduced into the apparatus while being sucked by the vacuum source 28 (first and second on-off valves). 25 and 30 may be opened), and Ar gas may be blown into the cavity C.
[0049]
Thus, if Ar gas is blown into the cavity C in advance, the base piston 6 is raised, and the device from the Ar gas source 22 immediately before the Mg casting device 1 changes from the first mode to the second mode. The introduction of gas into the inside may be started.
[0050]
The Ar gas flow rate when Ar gas is blown into the cavity C may be different from the Ar gas flow rate when molten metal is poured into the cavity C. This can be done by operating the flow regulating valve 24. For example, in order to promote hot water in the cavity C, the amount of Ar gas introduced during pouring may be increased (when the apparatus 1 is in the second mode).
[0051]
Conversely, when it is not necessary to consider the amount of hot water flowing into the cavity C, the suction may be stopped by closing the second on-off valve 30 during pouring or while the Mg lump is being dissolved.
[0052]
The above-described Mg casting apparatus 1 is not provided with any heating means such as a heater in the apparatus. For example, in order to improve the hot water performance of the cavity C, a heating source (for example, around the mold 55) , An electric heater) may be provided to control the temperature of the mold 55.
[0053]
A crucible is formed by making a pouring hole in which the diameter of the injection pouring hole 57 at the bottom of the crucible 55 described above is relatively large and a shutter (not shown) is disposed between the crucible 55 and the mold 50. When the Mg lump in 55 is melted, Mg may be filled into the mold 50 from the pouring hole of the crucible 55 that opens the shutter.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of an Mg casting apparatus according to an embodiment.
FIG. 2 is a view for explaining an aspect of a previous stage in which a crucible heated externally is set in the Mg casting apparatus of FIG. 1;
FIG. 3 is a flowchart for explaining an operation procedure from a step of heating the crucible to the pouring process.
FIG. 4 First, a heated crucible is set in the Mg casting apparatus, and then the Mg mass is put into the crucible and then the lid is closed to supply Ar gas into the Mg casting apparatus. It is a figure for demonstrating the state which Ar gas is blown into the cavity of a shaping | molding die while making the inside of an apparatus into Ar gas atmosphere in the process in which Mg lump melt | dissolves.
FIG. 5 is a view for explaining a state in which molten Mg is poured into a mold.
FIG. 6 is a flowchart related to FIG. 3 for explaining another operation procedure from the step of heating the crucible to the pouring process.
FIG. 7 is a view for explaining the timing of blowing Ar gas into the cavity of the mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mg casting apparatus 2 Apparatus main body 3 Cover body 6 Base piston 10 Gas induction cylinder 22 Ar gas source 51 Mold D C Mold cavity 52 Intermediate ring 55 Crucible 57 Pouring hole 59 Microwave oven 60 Mg lump

Claims (11)

Prepare a crucible without heating means,
When the crucible heated by an external heating means is placed on the mold placed in the Mg casting apparatus, and the Mg lump charged in the heated crucible is melted, the pouring at the bottom of the crucible An Mg casting method characterized by pouring molten metal from a hole into a mold. The pouring hole at the bottom of the crucible has a small diameter, and when pouring Mg melted in the crucible into the mold, gas is introduced into the crucible and Mg in the crucible is introduced. The Mg casting method according to claim 1, wherein the molten metal is poured into the mold from the small-diameter pouring hole. The Mg casting method according to claim 1 or 2, wherein the step of introducing the Mg mass into the heated crucible is performed after the heated crucible is placed in the Mg casting apparatus. The Mg casting method according to claim 1 or 2, wherein the step of introducing the Mg mass into the heated crucible is performed before the heated crucible is put into the Mg casting apparatus. The Mg casting method according to claim 1, wherein the pouring is performed in an inert gas atmosphere. The Mg casting method according to claim 5, wherein when the Mg is poured into the mold, the cavity of the mold is sucked. The Mg casting method according to claim 1, wherein the casting mold is made of a heat-resistant investment material by a lost wax method. A bottomed body that opens upward;
An openable / closable lid that closes the opening of the body;
A gas guide cylinder hanging downward from the lid;
An Mg casting apparatus is provided that is disposed at the lower end of the main body and includes lifting means for lifting the mold.
Prepare a crucible with a relatively small diameter pouring hole at the bottom and no heating means,
Placing the crucible heated by an external heating means on the mold at an interval;
Before or after disposing the crucible heated by the external heating means on the mold at an interval, and putting Mg mass into the crucible;
When Mg in the crucible can be poured into the mold, the mold is raised by the lifting means to engage the crucible, and the crucible and the gas guide cylinder are further engaged. Process,
And a step of introducing a gas into the gas guide cylinder and filling the mold with the Mg in the crucible through the pouring hole. The Mg casting method according to claim 8, further comprising a step of sucking the mold when Mg in the crucible is poured into the mold. The Mg casting method according to claim 8 or 9, further comprising a step of introducing an inert gas into the mold before pouring Mg in the crucible into the mold. A bottomed body that opens upward;
An openable / closable lid that closes the opening of the body;
A gas guide cylinder hanging downward from the lid;
Elevating means disposed at the bottom of the main body for elevating the mold;
An inert gas supply means for supplying an inert gas into the gas guiding cylinder;
Suction means for sucking the cavity of the mold ;
Having a crucible without heating means ,
When the crucible heated by the external heating means is arranged on the mold at an interval and the Mg in the heated crucible can be poured, the mold is raised by the elevating means. The crucible is engaged by the inert gas supplied from the inert gas supply means into the gas guide cylinder by engaging the mold and further engaging the mold and the gas guide cylinder. Mg casting is characterized in that Mg in the mold is poured into the mold through a pouring hole at the bottom of the crucible, and the cavity of the mold is sucked by the suction means during the pouring. apparatus.

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