JP3302134B2 - Differential pressure casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure casting apparatus mainly used in the field of dental casting and used for casting metal crowns and the like.

[0002]

2. Description of the Related Art A crucible is disposed in a chamber supported so as to be rotatable from one of an upright position and an inverted position to the other, and a metal material is accommodated therein and melted by heating. A mold having a cavity for forming a crown or the like is placed above the chamber, the chamber is made airtight, the gas inside the chamber is suctioned out, a vacuum is created, and then the chamber is turned upside down. Move, pour the molten metal in the crucible into the gate of the mold that has been positioned below, and then introduce atmospheric pressure or a gas at or above atmospheric pressure into the chamber to pressurize the chamber, Using the pressure difference between the gas pressure and the vacuum state in the cavity,
Spreading molten metal to every corner in the cavity,
2. Description of the Related Art A casting technique using a differential pressure casting apparatus for obtaining a metal casting such as a crown having a precise shape, that is, a casting technique is widely known.

As a conventional example of such a differential pressure casting apparatus,
The one described in Japanese Utility Model Publication No. 60-15120 is known. Conventionally, as typified by the one described in this publication, the operation of rotating the chamber from one of the upright position and the inverted position to the other has been performed by manually operating a steering wheel.

[0004] The melting of the metal material in the crucible is performed by controlling a crucible heating means disposed in the chamber. When a predetermined time elapses after reaching a preset melting temperature, an alarm such as a buzzer is issued. Thus, the operator is notified that the metal material is in a molten state.

[0005]

However, according to the above conventional example, since the rotation operation of the chamber is performed manually, the control of the rotation speed is not always successful, and the chamber is moved from the upright position to the inverted position. When rotated, the molten metal (which is spherical due to surface tension) poured from the crucible into the gate of the mold has a large swinging motion and is not easily stabilized on the gate. Was.

In the metal melting step, even if the melting temperature and the melting time are set to appropriate values in accordance with the type of the metal material, and the heating is performed accordingly, the set values are not always optimal. However, there is no guarantee that the metallic material is actually completely melted since the structure of the metallic material does not always match the expected structure.

[0007] In order to confirm this, the operator shakes the chamber by hand or hits the chamber.
Vibration was applied to the molten metal in the crucible, and the flow state was visually observed to confirm whether the metal material was completely melted. However, with such a method, there is a problem that it is difficult to visually check if the shaking of the chamber is small, and it takes time to stabilize if the shaking is too large, or if the chamber is hit too much, the chamber etc. There is a problem that it is damaged, and furthermore, there is a problem that operation handling becomes complicated.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first invention of the present application includes a chamber supported to be rotatable from one of an upright position and an inverted position to the other, and an inside of the chamber. Gas suction / discharge means for changing the state from one of a vacuum state and a pressurized state to the other, a crucible support means for supporting the crucible, a crucible heating means for heating the crucible, and a mold for supporting the mold at a position above the crucible A differential pressure casting apparatus provided with a supporting means, a motor for rotating the chamber, control means for controlling the driving of the motor, and a shaking button for sending a signal to the control means, wherein the control means When an input signal is received from a button, the motor is driven and controlled so that the chamber makes a minute reciprocating rotation.

A second invention of the present application solves the above-mentioned problems and provides a differential pressure casting apparatus capable of reliably introducing a differential pressure of a molten metal into a cavity in a mold. The means is characterized in that after the chamber is turned from the upright position to the inverted position, control is performed to switch the gas suction / discharge means to the gas introduction state after a predetermined waiting time.

[0010]

According to the first aspect of the present invention, the rotation from the chamber upright position to the inverted position can be performed by driving the motor in a state controlled by the control means. Therefore, the molten metal poured from the crucible to the gate of the mold can be prevented from swinging and a stable state can be obtained quickly. Further, the rotation of the chamber can be automatically performed, and the operation becomes convenient.

[0011] By using the motor used for the above-mentioned purpose, the operator presses a shaking button to visually confirm whether or not the metal material is completely melted.
Only by performing N operations, the chamber can be minutely reciprocated at the most ideal amplitude and speed. Thereby, the flow state of the molten metal in the crucible can be visually observed, and whether or not the molten metal is completely melted can be extremely easily confirmed, and it is difficult to confirm as in the conventional example, or it takes too much time to be stabilized. Problems such as the possibility of damaging the chamber and the like can be solved.

According to the second aspect of the present invention, the rotation of the chamber from the upright position to the inverted position is appropriate, and the swinging movement of the molten metal on the gate of the mold can be reduced. After a waiting time, the gas suction / discharge means is switched to the gas introduction state, the gas is introduced into the chamber, and the differential pressure of the molten metal is introduced into the cavity in the mold. If the waiting time is not taken, the spherical molten metal will oscillate, creating a gap in the passage to the cavity, introducing gas into the cavity and impairing the vacuum state in the cavity, resulting in precise differential pressure casting. There was a problem that there was no such problem, but this problem can be solved by the second invention.

[0013]

FIG. 1 shows an entire embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a machine base, 2 denotes a chamber supported on the machine base 1 so as to be rotatable from one of an upright position and an inverted position to the other, and 3 denotes an operation panel provided on the machine base 1. .

The chamber 2 comprises a container part 4 and a lid part 5, and the lid part 5 is connected to the container part 4 via hinges 6, 6 so as to be openable and closable.

FIG. 2 shows the chamber 2, its internal structure,
And a structure for driving the chamber 2 to rotate forward and backward in detail. As shown in FIG. 2, the container part 4 of the chamber 2 is composed of a container body 4a and a container outer case 4b, and the lid part 5 of the chamber 2 is composed of a lid body 5a and a lid outer case 5b. As described above, the container part 4 and the lid part 5 are connected via the hinges 6, 6, but to be precise, the container outer case 4b and the lid outer case 5b are connected via the hinges 6, 6. Are combined. Lid outer case 5b
Has a handle 7 and a locking means 8 for closing the lid (see FIG. 1), and turns the lid outer case 5b around the hinges 6 and 6 using the handle 7 to close the lid on the container outer case 4b. Sometimes, it is locked automatically.

The lid main body 5a is formed of a first coil spring.
It is supported by the lid outer case 5b under the pressure of the spring 9. That is, the first spring 9 is interposed between the ceiling surface of the lid exterior case 5b and the top surface of the lid main body 5a, and the flange 10 provided on the outer periphery of the lower portion of the lid main body 5a, and the lid exterior below the corresponding position. It is configured such that a stopper 11 provided on the inner periphery of the case 5b can be locked. In the open state shown in FIG. 2, there is a gap between the flange 10 and the stopper 11, but in the closed state, the flange 10 and the stopper 11 are locked under the pressing force of the first spring 9. The lid body 5a is supported by the lid outer case 5b in a state where a certain degree of freedom of movement is given.

A guide member 12 is provided on the ceiling of the lid body 5a.
Pressing tool 13 guided and supported slidably up and down by
Are arranged. The mold pressing member 13 has a flange portion 13a at an upper end, is prevented from falling down, and has a coil spring interposed between the ceiling surface of the lid body 5a and the bottom surface of the mold pressing member 13. The second spring 14 receives a downward spring force. The spring constant of the second spring 14 is set smaller than that of the first spring 9.

The container body 4a and the container outer case 4b are integrally connected by a rotating shaft 15 arranged in a horizontal state. The rotating shaft 15 is supported by bearings 16, 16, and receives rotation driving force from a motor 17 via a transmission means such as a timing belt 18, rotates forward and backward, and moves the chamber 2 from the upright position to the inverted position, or It is caused to rotate from the inverted position to the upright position, or to perform a minute reciprocating motion described later. A gas suction / discharge passage 19 penetrating through the axis of the rotating shaft 15 and communicating with the inside of the container main body 4a is formed, and sends air into the chamber 2 or removes air inside the chamber 2. Thus, the inside of the chamber 2 can be brought into a vacuum state. Reference numeral 20 denotes a pressure sensor for detecting the pressure inside the gas suction / discharge passage 19.

In the container main body 4a of the chamber 2, a carbon crucible 21 is formed with an opening 21 having a large thickness.
A crucible support means 22 is provided to support the crucible so that it can be inserted and removed with a facing upward. The crucible supporting means 22 includes a ceramic crucible retort 22a, and a crucible retort 22a.
a bottomed support cylinder 22b made of a heat insulating material that supports a, and a base 22c that supports the bottomed support cylinder 22b.
The base 22c is fixed on the bottom surface of the container body 4a.
The crucible retort 22a is formed in a cylindrical shape with a bottom so that the crucible 21 can be stored and supported in a fitted state, and when the crucible 21 is stored, the upper part of the crucible 21 is crucible retort 22a.
It is configured to be exposed from the upper end of a.

A space is formed between the side peripheral surface of the crucible retort 22a and the inner peripheral surface of the bottomed support cylinder 22b. A crucible heating made of a coil-shaped heating wire for heating the crucible 21 is provided in this space. Means 23 are provided. The crucible heating means 23 heats the crucible retort 22a, thereby heating the crucible 21 inside the crucible 21 and melting the metal 24 in the crucible 21. Reference numeral 25 denotes a temperature sensor including a thermocouple for detecting the temperature of the crucible 21.

On the crucible support means 22, a mold 26 is provided.
Is fixed to a mold supporting plate (mold supporting means) 27 which supports the mold with its gate 26a facing down. This mold support plate 27
Has an opening 28 through which the opening 21a of the crucible 21 is inserted, as shown in detail in FIGS.
The first opening 21a of the crucible 21 is engaged with the first opening 21a.
A gap P between the mold and the gate 26a of the mold 26 (see FIG. 10)
Is provided.

The mold support plate 27 has a circular metal plate portion 27a.
And a heat insulating plate portion 27b formed of a thick circular heat insulating material integrally formed thereon, and the circular opening 28 is opened at the center thereof. Then, a part of the heat insulating plate portion 27b is removed into a shape as shown in FIG.
The gas flow passage 30 is formed, and the stopper 29 is attached to the removed portion Q.

The portion Q includes a wide portion on the outer peripheral side and a narrow portion on the inner peripheral side, and the narrow portion reaches the opening 28. A cover plate 29b having a window 29a is fixed to the metal plate portion 27a with a gap provided in a wide portion. Stopper piece 2 in the gap
9c is slidably inserted, and a rear upright portion 29d of the rear portion protrudes outside from the window 29a. The window 29a is formed so as to match the width of the rear upright portion 29d of the stopper piece 29c, determines the sliding direction of the stopper piece 29c, and determines the sliding amount of the stopper piece 29c. The front upright portion 29e at the front of the stopper piece 29c is upright to the level of the upper surface of the heat insulating plate portion 27b, and has a hook portion 2 which is bent inward at the tip thereof.
9f.

As shown in FIG. 1, when the chamber 2 rotates from the upright position to the inverted position, the stopper 29 automatically moves to the locked position by its own weight, as shown in FIG. Is configured.
Of course, the stopper piece 29c is manually moved by gripping the rear upright portion 29d with tweezers or the like from one of a locking position (a position shown by a solid line in FIG. 4) and an open position (a position shown by a virtual line in FIG. 4). It can also be done. When the chamber 2 is turned to the inverted position as shown in FIG. 10, the stopper 29 is locked in the opening 21 a of the crucible 21 and the opening 21 a of the crucible 21 and the gate 26 of the mold 26.
This serves to secure a gap P between the gap P and a.

The gas flow passage 30 formed by using the point Q communicates the space P with the outer peripheral space of the mold 26, and smoothly introduces the air introduced into the chamber 2 to the gate 26a. Acts as a guide.

As shown in FIG. 2, the mold 26 includes a metal ring 26b and a cavity 26c and a gate 26a formed by a lost wax method.
The illustrated example forms a crown, and the cavity 26c
Is formed in a shape conforming thereto. This mold 26
Is centered by a centering means 31 whose restriction diameter can be adjusted.

As shown in detail in FIGS. 5 and 6, the centering means 31 includes an upper rotating ring 31a, four restraining levers 31b, 31b..., A lower fixing ring 31c, and four support pieces 31d, 31d. have. Four support pieces 31
are fixed to the upper end of the inner peripheral wall of the container body 4a of the chamber 2 at equal intervals by welding or the like. The lower fixing ring 31c is fixed on the support pieces 31d, 31d, and the four restraining levers 31b, 31b are pivotally supported at their base ends by a pivot 31e. The lower fixing ring 31c has guide arc holes 31f, 31f.
Are formed, and each of the restraining levers 31b is formed with an elongate cam hole 31g obliquely inclined in the circumferential direction. An upper rotation ring 31a is mounted on the restraining levers 31b, 31b,.
1a is an operation knob 31h, 31h having a screwing function.
, And four cam pins 31i, 31i, which are fitted and inserted into the cam holes 31g, 31g, and the guide arc holes 31f, 31f, respectively.

According to the centering means 31 constructed as described above, as shown in FIG.
h, the upper rotation ring 31a is rotated as shown by the arrow R, so that each of the restraining levers 31b, 31b... can be rocked as shown by the arrow S. The centering of the mold 26 can be performed by contacting the inverted surface.

When the chamber 2 is closed, as shown in FIG. 2, the mold 26 is placed on the mold support plate 27 while being elastically pressed by the mold pressing tool 13 with the gate 26a facing down. Is placed. At the same time, the lid main body 5a and the container main body 4a are joined, and the O-ring 3 disposed between the joining surfaces of the two.
2, the airtightness of the inside of the chamber 2 is maintained.
Since the spring constant of the first spring 9 is set to be larger than that of the second spring 14, the joining between the lid body 5a and the container body 4a is stable. Also, since the lid body 5a is supported by the lid outer case 5b with a certain degree of freedom of movement, that is, is supported in a floating state, the joining position with respect to the container body 4a when the chamber 2 is closed is set to a position suitable for joining. As a result, the airtight state of the chamber 2 can be improved.

FIG. 7 is a block diagram showing the relationship between driving, gas suction / discharge, and control of the apparatus. In FIG. 7, 33 is a controller (control means), 34 is a vacuum pump, 35 is an atmosphere introduction valve, 36 is a power plug, 37 is a power switch, 38
Is a heater current sensor, 39 is a heater transformer, 40 is a lid switch, 41 is a chamber position sensor, and 42 is a buzzer. In FIG. 7, a solid line indicates an electric system, and a broken line indicates a piping system.

As shown in FIG. 7, the internal space of the chamber 2 communicates with a vacuum pump 34 and an atmosphere introduction valve 35 through a gas suction / discharge passage 19 and a pipe provided in the rotating shaft 15. These operations are controlled by the controller 33. The pressure in the gas suction / discharge passage 19 is detected by the pressure sensor 20, and a signal thereof is sent to the controller 33. Opening and closing of the lid 5 of the chamber 2 is detected by the lid switch 40, and a signal thereof is sent to the controller 33. The rotation of the chamber 2 is performed by forward and reverse rotation of the motor 17 that operates based on a command from the controller 33.
The rotation position of the chamber 2 is detected by the chamber position sensor 41, and a signal thereof is sent to the controller 33. When the power switch 37 is turned on, the controller 33 is supplied with power from a power supply via a power plug 36.
The heater (crucible heating means) 23 is controlled by a controller 33 and is heated by a current supplied from a heater transformer 39. The controller 33 controls the current of the heater 23 based on information from the heater current sensor 38 and the temperature sensor 25. Data is transmitted and received between the controller 33 and the operation panel 3.

The operation panel 3 is configured as shown in FIG. Reference numeral 3a denotes a preheating indicator lamp, which blinks during preheating and turns on after completion of preheating. Reference numeral 3b denotes a state display unit for notifying a start temperature, a melting temperature, a melting time, and a state of casting by flashing a lamp in the middle, and lighting a lamp when achieved or completed, respectively. When a numerical value is selected, the corresponding portion is notified by lighting. Numeral 3c denotes a numerical display for numerically displaying the temperature or the time. Reference numeral 3d denotes a course display section, which displays the number of the selected course (program mode). A program data input button 3e is used to set a numerical value in a mode other than the existing program mode. Numeral 3f is a numerical value increase / decrease button, which can increase or decrease the numerical value shown on the numerical display portion 3c or the course display portion 3d.

Reference numeral 3g denotes a set button for setting a selected numerical value. Reference numeral 3h denotes a melting start button which is turned on when melting is started. Reference numeral 3i denotes a plus heating button for setting the melting temperature to a temperature higher by 10 ° C. every one ON operation than the initially set temperature. Reference numeral 3j denotes a shaking button for swinging the chamber 2 as required. 3k
Is a casting start button, which is turned ON when casting is started.

Next, a casting method of the present apparatus will be described with reference to FIG.

The chamber 2 is in the upright position, the lid 5 is opened, and the crucible 21 and the mold 26 are outside. The casting conditions are set by operating the operation panel 3.
Normally, casting conditions are set by selecting one of the courses (program modes) shown in the course display section 3d. The controller 33 stores several types of data maps about the start temperature after the preheating, the melting temperature, the melting time, and the casting processing time so as to be optimal for the type of the metal material, and the operator operates the numerical value increase / decrease button 3f. Thus, the optimum course is determined by visually checking the numerical value on the course display section 3d, and is determined by turning on the set button 3g. If there is no optimal course among the existing courses, the program data input button 3e is turned on to change the numerical value of the existing course. First, the start temperature is displayed on the numerical display section 3c, and this is displayed on the numerical value increase / decrease button 3
The value is increased / decreased with f, and the set button 3g is turned ON to fix the value.

Subsequently, the melting temperature is set in the same manner, and subsequently, the melting time and the casting processing time are similarly set.

When the power is turned on in the state where the casting conditions are set as described above, a preheating step is started as shown in FIG. 9, and the crucible heating means 23 generates heat to heat the crucible retort 22a. The temperature of the crucible installation part is once 1200
° C, and then start temperature (eg 900
(° C.) and maintain that temperature. The crucible retort 22a has a substantially uniform temperature as a whole in this preheating step.

A crucible 21 containing a metal material 24 is placed in a standby chamber 2 maintained at a start temperature.
Is inserted. The upper end of the opening 21 a of the crucible 21 is arranged substantially flush with the upper surface of the mold support plate 27. Then
When the melting start button 3h is turned on, the melting process starts, the heat generated by the crucible heating means 23 increases, the temperature rises, and the crucible 21 is heated to a predetermined melting temperature (for example, 1400 ° C.). When a predetermined time (melting time) has elapsed from ON, the buzzer 42 sounds.

As a result, the metal material 24 in the crucible 21 is generally completely melted, but the state can be confirmed by visual inspection of the operator.

This apparatus has a shaking button 3j so that the molten state of the metal material 24 in the crucible 21 can be easily checked visually. When the shaking button 3j is turned on, the controller 33 issues a command to the motor 17 to perform minute forward / reverse rotation based on the signal, and the forward / reverse rotation of the motor 17 causes the chamber 2 to have an amplitude 2c.
One reciprocating rotation of about m is performed (indicated by T in FIG. 9). As a result, the molten metal material 24 in the crucible 21 flows.
The operator can easily determine whether or not the metal material 24 inside has completely melted.

The melting temperature is set optimally in accordance with the kind of metal of the metal material 24 in the crucible 21.
In some cases, the prediction is not as expected, and it may be found that the metal material 24 in the crucible is not completely melted. In this case, by turning on the plus heating button 3i, the set value of the melting temperature can be set higher in units of 10 ° C. If the plus heating button 3i is turned on twice, the melting temperature will be 20 ° C to the original set value.
Can be enhanced. Of course, the temperature value that rises with one ON is not limited to 10 ° C., and can be arbitrarily determined.

As described above, when it is confirmed that the metal material 24 in the crucible 21 is completely melted, the mold 26 is set on the mold support plate 27 next. After being centered by the centering means 31, the lid 5 is closed. The mold 26 is supported between the mold pressing tool 13 and the mold support plate 27 in a compressed state by receiving the spring force of the second spring 14, and the gate 26 a of the mold 26 faces the opening 21 a of the crucible 21 of the crucible 21. It will be in the state of having done. The closure of the lid 5 is confirmed by the lid switch 40, and then the casting process button is started by turning on the casting start button 3k.

Then, based on ON of the casting start button 3k,
Simultaneously with the closing of the air introduction valve 35, the vacuum pump 34 is operated, and the air in the chamber 2 is suctioned and eliminated through the gas suction / discharge passage 19 and the piping for a predetermined time (for example, 23 seconds), and the chamber 2 is evacuated. Even during this vacuum suction, the temperature of the crucible 21 is kept at the melting temperature.

When it is confirmed by the pressure sensor 20 that the pressure in the chamber 2 reaches a predetermined degree of vacuum (for example, 10 Torr) during the vacuum suction, the motor 17 rotates to rotate the chamber 2 from the upright position to the inverted position. Move. With this rotation, the stopper piece 29c of the stopper 29 slides by its own weight, and its hook 2
9f locks the opening 21a of the crucible 21, thereby preventing the crucible 21 from dropping out of the crucible retort 22a. When the chamber 2 reaches the inverted position, the metal material 24 in the crucible 21 has been poured into the gate 26a of the mold 26 as shown in FIG.

In the prior art, when the chamber 2 reached the inverted position, the vacuum pump 34 was immediately stopped and the air introduction valve 35 was opened, but in this case, it became spherical. When the metal material 24 swings, a gap is formed in the passage to the cavity 26c, and there is a risk that the air is introduced into the cavity 26c and the vacuum state of the cavity 26c is damaged. Therefore, in this apparatus, after the chamber position sensor 41 detects that the chamber 2 has reached the inverted position, the vacuum pump 34 is stopped after a waiting time (for example, 1.5 seconds), and the air introduction valve 35 is opened. Control. By providing such a waiting time, the metal material 24 in the crucible 21 is in a stable state, and the passage to the cavity 26c can be reliably closed. The air (atmosphere) introduced from the atmosphere introduction valve 35 is introduced into the chamber 2 through the pipe and the gas suction / discharge passage 19, and the air introduced into the chamber 2 is supplied to the gas flow passage 30 provided in the mold support plate 27 and Crucible 2 by the stopper 29
1 smoothly reaches the upper surface of the metal material 24 on the gate 26a through the gap P secured between the mold 26 and the metal material 24 by the pressure difference between the air pressure and the vacuum state of the cavity 26c. Squeeze into each other,
Precision casting is performed. The pressure in the chamber 2 returns to the atmospheric pressure in about 0.2 seconds by the introduction of the atmosphere. However, since the air is smoothly introduced into the gate 26a of the mold 26, the same applies to the precision casting. It is performed smoothly in a short time.

From the operation of the vacuum pump 34 to the atmosphere introduction valve 35
When the operation is switched to the operation, the energization to the crucible heating means 23 is stopped at the same time, and the cooling process starts. The inside of the chamber 2 is naturally cooled, and the metal material 24 filled in the cavity 26c starts to solidify. When a predetermined casting time (for example, 10 seconds) has elapsed from the switching point, the motor 17 is driven based on a command from the controller 33, and the chamber 2 is rotated from the inverted position to the upright position by rotation in the reverse direction. When the chamber position sensor 41 detects that the chamber 2 has reached the upright position, a buzzer 42 sounds,
Notifies the end of work. The operator opens the lid 5 and opens the mold 2.
6 is taken out, the stopper piece 29c is moved to the open position, and the crucible 21 is taken out, so that the next operation is started. When the temperature in the chamber 2 drops to the start temperature, the crucible heating means 23 is energized again, and the temperature in the chamber 2 is controlled so as to maintain the start temperature.

The present invention can be configured in various modes in addition to the embodiments described above. For example, in the above embodiment, atmospheric pressure is introduced into the chamber 2 and the inside of the chamber 2 is pressurized.
It may be introduced inside. Also, the minute reciprocating rotation of the chamber 2 by turning on the shaking button 3j can optimally set the amplitude, the number of reciprocations, and the like.

[0048]

According to the first aspect of the present invention, the chamber swinging operation required for visually confirming whether or not the metal material in the crucible has completely melted in the metal melting step is ideally and automatically performed. Can be performed, which contributes to accurate casting, makes the operation convenient, and requires the swinging motion of the molten metal poured into the mold gate when the chamber is inverted. It can be minimized and can contribute to performing differential pressure casting quickly and accurately.

According to the second aspect of the present invention, in addition to the above-described effects, the differential pressure casting process is started by stabilizing the swinging motion of the molten metal on the gate of the mold, so that more accurate casting is performed. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire embodiment of the present invention.

FIG. 2 is a vertical sectional front view of the main part.

FIG. 3 is a plan view showing a mold supporting plate.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a plan view showing a centering means.

FIG. 6 is an exploded perspective view showing a centering means.

FIG. 7 is a block diagram showing a control / drive system.

FIG. 8 is a diagram showing an operation panel.

FIG. 9 is a timing chart of a control / drive system.

FIG. 10 is a sectional view showing the chamber in an inverted position.

[Explanation of symbols]

 2 Chamber 3j Shaking button 17 Motor 19, 34, 35 Gas suction / discharge means 21 Crucible 22 Crucible support means 23 Crucible heating means 26 Mold 27 Mold support means 33 Control means

Claims (2)

(57) [Claims] 1. A chamber supported to be rotatable from one of an upright position and an inverted position to the other, and a gas for changing the inside of the chamber from one of a vacuum state and a pressurized state to the other. A motor for rotating a chamber in a differential pressure casting apparatus comprising suction / discharge means, crucible support means for supporting a crucible, crucible heating means for heating a crucible, and mold support means for supporting a mold at a position above the crucible. And a control means for controlling the driving of the motor, and a shaking button for sending a signal to the control means, wherein the control means receives an input signal from the shaking button,
A differential pressure casting apparatus characterized in that the motor is driven and controlled so that the chamber makes a minute reciprocating rotation. 2. The control device according to claim 1, wherein after the chamber is turned from the upright position to the inverted position, the control unit switches the gas suction / discharge unit to a gas introduction state after a predetermined waiting time. The described differential pressure casting apparatus.