JPH077013Y2 - Vacuum press differential pressure casting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Field of Industrial Application) The present invention mainly relates to a casting machine for dental members such as artificial teeth and crowns. More particularly, the present invention relates to a vacuum pressure differential pressure type casting machine suitable for precision casting of low specific gravity, high temperature high viscosity or low viscosity molten materials such as porcelain and crystallized glass.

(Prior Art) Conventionally, for making dental members such as artificial teeth and crowns,
It is well known that a so-called vacuum pressure casting device has been used.

An example of this type of vacuum pressure casting apparatus is the apparatus disclosed in JP-A-58-4548. This equipment injects the metal material in the crucible melted under vacuum reduced pressure into the mold which is also under vacuum reduced pressure by reversing the equipment itself, and pressurizes and injects an inert gas to generate the differential pressure and molten metal. The weight of the material will cause the molten metal material to be cast into the mold cavity.

However, in the above apparatus, since the vent hole for depressurizing and pressurizing the inside of the mold cavity is on the casting side, the effective differential pressure between depressurizing and pressurizing is small, and it has a high specific gravity and low as metal. There are few problems when casting a viscous molten material, but it is extremely difficult to cast precisely to the end of the cavity when using a material that has a low specific gravity and high viscosity compared to metals such as glass ceramics. . That is, since depressurization and pressurization are performed in the same direction with respect to the cavity, when depressurization and pressurization are performed at the same time, they are offset by plus and minus, and the differential pressure is small. Even if the pressure difference is initially large, it will decrease over time during pressurization, and after all, effective pressure pressure for casting cannot be obtained despite the large power used for pressure reduction and pressurization. This is because there is a drawback.

In order to solve the above-mentioned drawbacks of the prior art, the present inventors increase the differential pressure by performing suction decompression and pressurization along the casting direction on the cavity of the mold to reduce the low specific gravity. Moreover, we have proposed a vacuum pressure casting machine that can accurately cast even the highly viscous molten material to the end of the cavity (Japanese Utility Model Application No. 61-127323).

That is, as shown in FIG. 5, the previously proposed vacuum pressure casting machine has an airtight chamber body (1) for melting and casting, and an upper end opening of the airtight chamber body (1) which is openable and closable. A lid (2), a heating device (4) that is provided in the lower half of the airtight chamber body (1) and holds the melting crucible (3) so that it can be inserted and removed from above, and the heating device (4). ) And a mold (5) sandwiched between the upper end and the lid (2), and pressurized gas injection for pressurizing the inside of the airtight chamber body (1) and the mold (5) from the casting port (51) side. A means (6) and a decompression means (7) for sucking and decompressing the inside of the mold (5) from the upper bottom part (52) of the mold (5) through a pipe line (21) formed in the lid (2). The gist of the invention is that it comprises an inverting means (8) for inverting the airtight chamber body (1).

(Problems to be Solved by the Invention) Although the vacuum pressure casting machine proposed by the present inventor is superior to the conventional one, it is improved from the following viewpoints. I'm impatient. That is, in the casting of glass ceramics, etc., depending on the glass composition, the melting properties are wide ranging from low specific gravity and high viscosity to low specific gravity and low viscosity. It is not preferable because bubbles are mixed in with the molten metal.Therefore, it is necessary to devise to maintain the differential pressure for a long time even when the depressurizing operation is stopped.The molten metal is poured into the mold from the crucible. In order to reduce the effect of dividing the molten metal of the pressurized gas, it is preferable to drop the
From the point of view such as improvement.

An object of the present invention is to provide a vacuum pressurization differential pressure type casting machine which is improved from the above points.

[Purpose of device]

(Means for Solving the Problems) The structure of the vacuum pressurization differential pressure type casting machine of the present invention will be outlined with reference to the accompanying drawings.

FIG. 1 is a vertical sectional front view showing an example of the vacuum pressurization differential pressure type casting machine of the present invention, FIG. 2 is a sectional view of the casting machine in the direction of arrow A in FIG. 1, and FIG. 3 is an exploded view of the main parts of the casting machine. FIG. 4 and FIG. 4 are schematic circuit diagrams showing an example of a control mechanism of the casting machine.

That is, the vacuum pressurization differential pressure type casting machine of the present invention comprises: (i) an airtight chamber body (1) for melt casting, and a lid body (2) for opening and closing the upper end opening of the airtight chamber body (1). ), A heating device (4) equipped in the lower half of the airtight chamber body (1) and holding the melting crucible (3) so that the melting crucible can be inserted and removed from above, and an upper end and a lid of the heating device (4). A mold (5) sandwiched between the body (2) and a pressurized gas injection means (6) for pressurizing the inside of the airtight chamber body (1) and the mold (5) from the casting port (51) side. A depressurizing means (7) for sucking and depressurizing the inside of the mold (5) from the upper bottom part (52) of the mold (5) through a conduit (21) formed in the lid (2), and the above depressurizing means ( The exhaust means (8) for exhausting the pressurized gas at the time of stopping 7) and the reversing means (9) for reversing the airtight chamber body (1), (ii) or In the above (i), the partition wall which inserts the mold (5) between the upper end of the heating device (4) and the lid (2) and partitions the upper end of the heating device (4) and the lid (2). Board (57)
(Iii) Further, in the above (i) or (ii), a connecting plate (41) having a communication hole (411) in the center is placed on the upper end of the heating device (4), On the other hand, at the lower end of the mold (5), a mold receiving plate (53) having a communication hole (531) and a pressurizing ventilation slot (532) connected to the communication hole (531) in the centrifugal direction is disposed in the center. The upper end locking collar (31) of the melting crucible (3) is locked to the periphery of the communication hole (411), and the connecting plate (41) and the mold receiving plate (53) are united and bonded to each other to form an airtight chamber. The heating device (4) and the mold (5) are vertically connected and held in the main body (1), and the crucible (3) and the mold (5) are aligned with the center line of the crucible (3) and the center line of the mold (5). Keep it in coaxial alignment or
Alternatively, the gist is to maintain the crucible (3) and the mold (5) in an eccentric positional relationship between the center line of the crucible (3) and the center line of the mold (5).

The vacuum pressurizing differential pressure type casting machine of the present invention will be described in more detail with reference to the drawings. As shown in FIG. 1, the mold (5) has a desired shape (in FIG. 1, an artificial crown is shown). ) Of the air-permeable porous embedding material (50) including a cavity (cast molding part) (54) and a funnel-shaped casting opening (51) connected to the cavity (54), and the embedding material (50). It is composed of a mold ring (55) surrounding the side peripheral portion.

The mold (5) is sandwiched between the heating device (4) and the lid (2), and the cavity (54) has a casting port (51).
Through the melting crucible (3), while the upper bottom (5
The embedding material (50) of 2) directly contacts with the asbestos (22) as a heat-resistant sealing material arranged on the inner surface of the lid (2) including the suction port of the suction pipe line (21), Decompression means (7)
The suction and decompression inside the cavity (54) by the investment material (50)
It is mainly made only from the upper bottom part (52).

The mold (5) includes a heating device (4) and a lid (2).
A partition plate (57) provided at an intermediate position between the partition plate (57) and the partition plate (57) is mounted on the flange (571) of the inner wall of the airtight chamber body (1) and the reversing means (9). It is supported by a partition plate drop stopper (572) such as a spring provided on the lid body (2) so as not to fall when being inverted by an operation.
The partition plate (57) is well shown in FIG.

In the vacuum processing differential pressure type casting machine of the present invention, in order to pressurize the inside of the airtight chamber body (1) and the mold (5) from the casting port (51) side, the pressurized gas injection means (6), the mold (5) Of the suction pipe line (2) formed in the lid (2) from the upper bottom (52)
Pressurized gas may be passed through 1).

Further, in order to suck and depressurize the inside of the mold (5), the depressurizing means (7) may be operated.

Furthermore, in particular, when the casting material is one having a low specific gravity and a low viscosity among the glass ceramics, as will be described later, the cavitating gas injection means (6) and the decompression means (7) are simultaneously operated to cause the cavitation. Since the pressure difference between the pressurization and the depressurization in the tee (54) becomes large, air bubbles are easily generated in the cast product. Therefore, when casting such a casting material, when the depressurizing means (7) is deactivated, the exhausting means (8) for exhausting the pressurized gas is operated to adjust the differential pressure to an appropriate degree. Good.

In the vacuum pressurization differential pressure type casting machine of the present invention, as shown in FIG. 1, the heating device (4) and the mold (5) are connected vertically with the center line of the crucible (3) and the center of the mold (5). In addition to the manner in which the wires are connected in coaxial alignment, the embodiment also includes an embodiment in which the center line of the crucible (3) and the center line of the mold (5) are eccentrically connected as shown in FIG. .

When the heating device (4) and the mold (5) are connected in an eccentric positional relationship like the latter, operation of the reversing means (9) for inverting the positional relationship between the heating device (4) and the mold (5) described later. As a result, when the vertical positional relationship between the crucible (3) and the mold (5) is gradually replaced, the molten raw material in the crucible connects the wall surface of the crucible and is exactly on the center part of the casting port (51) of the mold (5). It will fall. The significance of this is important, and as a result, the molten raw material that has fallen to the center of the casting hole (51)
The pressurized gas is pressed into the cavity (54) to enable precise casting.

As described above, when the heating device (4) and the mold (5) are not in an eccentric positional relationship and the molten raw material falls outside the center portion of the casting port (51), the highly viscous molten raw material is pressurized gas. As a result, it is disrupted, preventing smooth press-fitting into the cavity.

Next, a procedure for casting a dental member using the vacuum pressure differential pressure type casting machine having the above-described configuration will be described.

First, the melting crucible (3) is set in the heating device (4), and a casting material such as crystallized glass is put in the crucible (3). The lid (2) covers the upper end opening of the airtight chamber body (1), and the heating device (4) melts the casting material such as crystallized glass in the crucible (3), and at the same time, the depressurizing means (7). In (), the inside of the airtight chamber body (1) is sucked and decompressed to prevent air bubbles from being mixed into the casting material. After confirming that the casting material has melted, the decompression means (7) is stopped, then the lid (2) is opened, the partition plate (57) is set, and the heating device (4) is set.
The mold (5) is placed on the upper end of the mold with its mouth (51) facing downward and through the through hole (573) of the partition plate (57) as shown in FIGS. At this time, for example, the heating device (4) is installed eccentrically with respect to the airtight chamber main body (1), while the through hole (573) of the partition plate (57) is coaxial with the central axis of the airtight chamber. If so, the melting crucible (3) and the center axis of the mold (5) are automatically eccentric by setting the mold (5). Then, the lid (2) is closed again and the lid (2) is closed.
The mold (5) is sandwiched between the heating device (4) and the heating device (4), and the partition plate (57) is fixed. The casting material is corrected and heated by the heating device (4) (because it is slightly cooled by opening the lid body (2)), and then the depressurizing means (7) is operated again, and the pipe line (21) of the lid body (2) is activated. And suction decompression inside the cavity (54) through the investment material (50) of the mold (5) (atmospheric pressure -600 to 700).
mmHg). The airtight chamber body (1) is inverted by 180 ° by the inversion means (9) while continuing to reduce the pressure by suction, and the molten casting material in the crucible (3) is injected into the mold (5). After this reversal, the pressurized gas injection means (6) is operated with a certain interval for a while, and pressurized gas such as air or an inert gas (for example, argon gas) is introduced into the mold (5) from the side of the casting port (51). Is injected (gas pressure, about 2 kg / cm ² ), while in the pipe line (21) of the lid (2) connected to the upper bottom part (52) of the mold (5), the pressure reducing means (7) is also used. The suction is continuously performed by and the molten casting material is cast into the cavity (54) due to the pressure difference between the pressure reduction and the pressure and the weight of the casting material itself. That is, since the pressure is reduced from the upper bottom portion (52) of the mold (5) and the pressurized gas is injected from the casting mouth (51) side, in the cavity (54), the pressure reduction and the pressure application are in the same direction. Acting along the casting direction, the differential pressure becomes synergistically large, and the casting material, together with its own weight, creates a cavity (54).
It is precisely cast into the terminal void (details). As a result, such a cast casting can be carried out very smoothly even with a low-specific gravity and high-viscosity molten casting material such as glass ceramics.

However, if the casting operation is continued in such a state, the differential pressure is large, and the glass-ceramic having a lower viscosity may generate air bubbles in the cast product. In this respect, the vacuum pressurization differential pressure type casting machine of the present invention has the exhaust means (8) branched to the depressurization means (7) in addition to the pressurized gas injection means (6) and the depressurization means (7) as described above. Since the glass-ceramics are provided, it is possible to accurately cast even a melt-cast material having a low specific gravity and a low viscosity among the glass ceramics without generating bubbles in the cast product. That is, in the case of a molten material having a low specific gravity and a low viscosity, the pressure difference between the pressurized gas injecting means (6) and the depressurizing means (7) is large, so that air is often entrained in the cavity (54). However, in such a case, the pressure reducing means (7) is stopped and the exhaust means (8) is switched to, so that the differential pressure can be appropriately adjusted. Further, since the vacuum pressurization differential pressure type casting machine of the present invention is provided with the partition plate (57) as described above, even if the depressurizing means (7) is stopped and the exhausting means (8) is operated, the pressurized gas is not generated. Leakage from the asbestos (22), which is a heat-resistant sealing material at the contact portion between the lid (2) and the mold (5), is reduced, and the pressure difference of the pressurized gas is maintained for a relatively long time. 51) It is possible to effectively act on the molten material. That is, even if the depressurizing means (7) is stopped, it is possible to prevent the inclusion of air bubbles and manufacture a cast product having excellent transferability of details.

(Example) Next, an example will be described.

In FIG. 1, a horizontal rotary shaft (91) is fixedly installed on the outer side of the airtight chamber body (1), and gears (92), (that mesh with each other are provided at the base end of the rotary shaft (91). The operation handle (94) is connected via 93), and these constitute the reversing means (9). The gear ratio of the gear (92) on the rotating shaft (91) side to the gear (93) on the operating handle (94) side is 1: 2, so that if the operating handle (94) is rotated 90 °, The rotating shaft (91) rotates 180 °, and the airtight chamber body (1) is inverted 180 °.

A pressurized gas injection conduit (61) and a suction suction decompression conduit (71) are dug in the rotary shaft (91), and the pressurized gas injection conduit (61) remains as it is. 1) while the suction decompression pipe (71) is connected to the pipe (21) of the lid (2) via the connecting pipe (72) attached along the outer wall of the airtight chamber body (1). It is designed to communicate. Further, the exhaust pipe line of the exhaust means (8) may be provided by branching to the pipe line of the pressure reducing means (7). And these pressurized gas injection lines (6
1), the suction and decompression pipeline (71) and the exhaust pipeline (81) communicate with a pressurized gas cylinder, a vacuum pump, and the atmosphere via a control valve (not shown) on the way. The heating device (4) is supported by several brackets (42) fixed to the inner wall of the airtight chamber body (1), and has a built-in heater bobbin (43) and a heater (44) surrounding the heater bobbin (43). There is. A connecting plate (41) having a communication hole (411) in the center is placed on the upper end of the heating device (4), and the connecting plate (41) has substantially the same shape as the communication hole (441). Communication hole (531) and the communication hole (53
1) Stacked mold receiving plates (53) each having a slot (532) extending in the centrifugal direction, the connecting plate (41) and the mold receiving plate (53) are part of the bracket (42) (at least 2). Bolts and nuts (56). The connecting plate (41) and the mold receiving plate (53) are made of an airtight material such as heat-resistant asbestos. As shown in FIG. 3, the connecting plate (41) is provided with a melting crucible at the periphery of the communication hole (411). The upper end locking collar (31) of (3) is locked and the crucible (3) is inserted into the heater bobbin (43), and then the mold receiving plate (53) is stacked and fixed as described above. Mold support plate (53)
The mold (5) is placed on top, and the mold (5) is sandwiched between the cover (2) and the heating device (4) by the cover of the cover (2). In this way, as shown in FIG. 2, the cavity (54) of the mold (5) and the melting crucible (3) are joined in an eccentric positional relationship, and the lower end of the mold (5) is connected. The slot (532) projects from the peripheral edge, and the inside of the cavity (54) of the mold (5) is pressurized through the slot (532). The melting crucible (3)
As the residue of the dissolved material adheres to the inner wall of the mold after repeated use, it must be pickled. In such a case, remove the mold (5) and loosen the bolts and nuts (56). It can be easily carried out by removing the mold receiving plate (53). The locking brim (31) of the crucible (3) is connected to the connecting plate (4
Since the slot (532) is locked to the peripheral edge of the communication hole (411) of 1), the slot (532) effectively functions as a pressurizing air passage.

FIG. 4 shows an example of the control circuit of the casting machine, and reference numerals (62), (73) and (83) in the figure respectively denote a pressurized gas supply solenoid valve, a suction solenoid valve and an exhaust solenoid valve. Show. The pressurized gas supply solenoid valve (62), the suction solenoid valve (73), and the exhaust solenoid valve (83) are the pressurized gas injection means (6), the pressure reduction means (7), It becomes a component of the exhaust means (8). And these solenoid valves (62), (73), (83)
Thus, pressurization, suction decompression, and exhaust in the airtight chamber body (1) are performed.

The suction solenoid valve (73) is turned on and off by operating the manual switch (74).
The power of all circuits is turned on and off by the operation of 4). Reference numerals (63) and (64) denote first and second delay relays on the solenoid valve side, which receive a signal from the reversing switch (switch ON when the operating handle (94) is rotated) (65). The solenoid valve (62) for supplying pressurized gas is opened and closed according to the properties of the molten material. That is, the signal from the inversion switch (65) is input to the first delay relay (63) with a delay of the time set by the midway timer (66),
The first delay relay (63) operates to open the electromagnetic valve (62), and pressurized gas is supplied into the airtight chamber body (1).
The reason why the pressurized gas is supplied with a delay after reversing the airtight chamber body (1) in this way is that the gas is still completely cast (5) immediately after reversal depending on the properties (particularly viscosity) of the molten casting material. This is because there is a case where the molten casting material is not transferred to the casting port (51) in this state, and when a pressurized gas is supplied in this state, a force for pushing the molten casting material back into the crucible (3) acts, and particularly, the metal material. Compared with the above, in the case of a low specific gravity and high viscosity material such as gas ceramics, such variable delay means is extremely effective. Also, the pressurizing operation signal of the first delay relay (63) passes through the intermediate timer (67) and then the second delay relay (64).
Is input to the delay relay (6
4) operates to turn off the pressurized gas supply solenoid valve (62), and the supply of the pressurized gas into the airtight chamber body (1) is stopped. It is natural that the pressurizing operation time by the timer (67) should be set to a time sufficient for the casting material to be cast into the cavity (54) of the mold (5). Since the pressurized gas supply causes supercooling of the casting material, an appropriate time lag is set in consideration of them.
On the other hand, depending on the composition of the ceramics, there is a material having a low specific gravity and a low viscosity as compared with the above-mentioned low specific gravity and a high viscosity material. When such a melt-cast material is cast, the pressure difference between the pressurization and the depressurization increases, and bubbles often become involved in the cast product, resulting in product defects. In the present invention, the following control is performed to improve such a drawback. That is, after the solenoid valve (62) starts to operate, the timer (7
Solenoid valve for suction (73) by delay relay (76) via 5)
To turn off. In this state, the molten casting material in the vicinity of the casting hole (51) is compressed only by the pressure of the pressurized gas and the cavity (5
4) It is cast inside. Next, when the pouring is completed, the exhaust solenoid valve (83) is turned on by the delay relay (82) via the timer (81). As a result, the pressurized gas after completion of the casting is released into the atmosphere through the exhaust pipe line which is connected to the exhaust electromagnetic valve (83). After that, the solenoid valve (62) is turned off by the delay relay (64) via the timer (67), and finally the timer (8
The exhaust solenoid valve (83) is turned off by 1), and one cycle of casting work is completed.

Although the configuration and the embodiment of the vacuum pressurizing differential pressure type casting machine of the present invention have been described above with reference to the drawings, the present invention is not limited to this, and it is needless to say that various modifications and changes can be made by those skilled in the art. Yes.

[Effect of device]

In the vacuum pressurization differential pressure type casting machine of the present invention, since the pressure is reduced from the upper bottom of the mold and the pressurized gas is injected from the casting side, the pressure reduction and the pressure increase in the same direction in the mold cavity. Since it acts along the casting direction, the differential pressure between the pressurization and the depressurization in the cavity becomes synergistically large, and the casting material, together with the weight of the casting material itself, causes the cavity at the end of the cavity. It is accurately cast into.

Further, in the present invention, since the adjustment of the above-mentioned differential pressure is performed by the exhaust means, a wide range of casting materials from low specific gravity and high viscosity based on the composition of ceramics to low specific gravity and low viscosity molten casting materials can be used. It is possible to perform precise casting without mixing air bubbles in the product.

In addition, in the present invention, by partitioning the mold side in the airtight chamber body with the partition plate, the differential pressure of the pressurized gas can be sufficiently utilized as the casting compression force even when the pressure reducing means is stopped.

Further, in the present invention, when the heating device and the mold are inverted, the molten casting material in the melting crucible of the heating device is configured so as to be suitable for the central portion of the casting port, that is, just above the runner. Casting can be performed extremely smoothly without being affected by the dividing action of the pressurized gas.

Further, in the present invention, since the melting crucible can be freely inserted and removed, even if the residue of the casting material adheres to the wall surface or the like during repeated use, it can be taken out and easily pickled. I can.

As described above, the vacuum pressurization differential pressure type casting machine of the present invention has excellent effects that cannot be achieved by the conventional apparatus, and its practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an example of the casting machine of the present invention, FIG. 2 is a sectional view of the casting machine in the direction of arrow A in FIG. 1, and FIG. 3 is an exploded perspective view of a main part of the casting machine. FIG. 4 is a schematic circuit diagram showing an example of a control mechanism of the casting machine, and FIG. 5 is a vertical sectional front view of the casting machine proposed by the present inventors. (Description of symbols) 1 ... Airtight chamber body, 2 ... Lid, 21 ... Pipe line, 3 ... Melting crucible, 31 ... Locking collar, 4 ... Heating device, 41 ... Connecting plate, 411 ... communication hole, 5 ... mold, 51 ... casting hole, 52 ...
... Upper bottom part, 53 ... Mold receiving plate, 531 ... Communication hole, 532 ... Slot, 57 ... Partition plate, 6 ... Pressurized gas injection means, 7 ...
... decompression means, 8 ... exhaust means, 9 ... inversion means.

Claims (5)

[Scope of utility model registration request] 1. An airtight chamber main body (1) for melt casting, a lid (2) for opening and closing an upper end opening of the airtight chamber main body (1), and an inside of the airtight chamber main body (1). A mold sandwiched between a heating device (4) equipped in the lower half of the heating crucible (3) that holds the melting crucible (3) so that the melting crucible (3) can be inserted and removed from above, and the upper end of the heating device (4) and a lid (2) (5), a pressurized gas injecting means (6) for pressurizing the inside of the airtight chamber body (1) and the mold (5) from the casting port (51) side, and the upper bottom part (52) of the mold (5). ), The pipe line (21) formed in the lid (2)
Depressurizing means (7) for sucking and depressurizing the inside of the mold (5) via
A vacuum pressurization differential pressure type casting machine comprising an exhaust means (8) for exhausting a pressurized gas when the decompression means (7) is stopped and an inversion means (9) for inverting the airtight chamber body (1). 2. A partition plate for inserting a mold (5) between the upper end of the heating device (4) and the lid (2) and partitioning the upper end of the heating device (4) and the lid (2). The vacuum pressurization differential pressure type casting machine according to claim 1, which is provided with (57). 3. The airtight chamber body (1), wherein the reversing means (9) is
A horizontal rotary shaft (91) fixed to the outer side of the horizontal rotary shaft (91), and an operation handle (94) connected to the base end of the horizontal rotary shaft (91) via gears (92) (93), The operation handle (94)
The airtight chamber body (1) is rotated 180 degrees by rotating the
The vacuum pressure differential pressure type casting machine according to claim 1 or 2, wherein the vacuum pressure differential pressure type casting machine is inverted. 4. A connecting plate (41) having a communication hole (411) in the center is placed at the upper end of the heating device (4), while a communication hole (531) is provided in the center at the lower end of the mold (5). ) And a ventilation slot (532) for pressurizing in the centrifugal direction which is continuous with the communication hole (531)
Is provided with a mold receiving plate (53), and the communication hole (41
Around the periphery of 1), the upper end locking collar (3) of the melting crucible (3)
1) is locked, and the connecting plate (41) and the mold receiving plate (53) are united and combined to hold the heating device (4) and the mold (5) vertically in the airtight chamber body (1). The crucible (3) and the mold (5) are maintained in coaxial alignment between the center line of the crucible (3) and the center line of the mold (5). The vacuum pressurization differential pressure type casting machine described. 5. A connecting plate (41) having a communication hole (411) in the center is placed at the upper end of the heating device (4), while a communication hole (531) is provided in the center at the lower end of the mold (5). ) And a ventilation slot (532) for pressurizing in the centrifugal direction which is continuous with the communication hole (531)
Is provided with a mold receiving plate (53), and the communication hole (41
Around the periphery of 1), the upper end locking collar (3) of the melting crucible (3)
1) is locked, and the connecting plate (41) and the mold receiving plate (53) are united and combined to hold the heating device (4) and the mold (5) vertically in the airtight chamber body (1). The crucible (3) and the mold (5) are maintained in an eccentric positional relationship between the center line of the crucible (3) and the center line of the mold (5). The vacuum pressurization differential pressure type casting machine described in 1.