JPH07132363A - Differential pressure casting apparatus - Google Patents

Abstract

PURPOSE:To secure a gap between the opening part of a crucible and the sprue of a mold even at the time of directing a chamber in the reverse standing state, to quickly act gas pressure at the time of introducing the gas to molten metal positioned in the space, to quickly and precisely cast a metal cast product and to smoothly execute inserting/removing operation of the crucible to/form a crucible supporting means. CONSTITUTION:An opening part 28 for inserting the opening part 21a of the crucible 21 is arranged in a mold supporting plate 27 and also, a stopper 29 for securing the gap between the opening part 21a of the crucible 21 and the sprue 26a of the mold 26 by engaging with the opening part of the crucible 21 is arranged in the condition of being possible to engage/disengage. Further, the gas flowing passage 30 communicating the gap with a space at the outer periphery of the mold is formed in the mold supporting plate 27.

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 placed in a chamber rotatably supported from one of an upright position and an upright position to the other, and a metal material is housed therein and melted by heating. Place a mold with a cavity for forming a crown in the upper part of the chamber, make the chamber airtight, and remove the gas inside to create a vacuum state, then turn the chamber to the upside-down position. The molten metal in the crucible is moved to the gate of the mold which is to be positioned below the crucible, and then atmospheric pressure or a gas at atmospheric pressure or higher is introduced into the chamber to pressurize the chamber. Utilizing the pressure difference between the gas pressure and the vacuum state in the cavity,
Spread the molten metal to every corner of the cavity,
BACKGROUND ART Obtaining a metal casting such as a crown having a precise shape, that is, a casting technique using a differential pressure casting device is widely known.

As a conventional example of such a differential pressure casting apparatus,
The one described in Japanese Utility Model Publication No. 3-8256 is known.
In this conventional example, the crucible is fixed by sandwiching the collar portion formed at the opening edge of the crucible between the crucible support plate and the mold support plate, and even when the chamber is in the inverted position, the crucible opening portion It is configured such that a gap is secured between the mold and the sprue. Further, a gas flow passage is provided in the mold support plate, the void and the outer peripheral space of the mold are communicated with each other, and when the gas is introduced, the gas pressure promptly acts on the molten metal located in the gate, and the molten metal reaches the details in the cavity. Are trying to spread.

[0004]

However, in the above-mentioned conventional example, since the crucible has a fixed structure, it is difficult to remove the crucible, and there is a problem that it takes time even if it can be removed.

A carbon crucible generally used as a crucible, when exposed to a high temperature condition, oxidizes carbon and accelerates the reduction of the wall thickness. Therefore, in order to prevent this, it is necessary to remove the crucible from the chamber at each casting. It is difficult to use the above conventional example.

A first object of the present invention is to ensure a space between the opening of the crucible and the sprue of the mold even when the chamber is in the inverted position, and the gas pressure at the time of introducing gas is located at the sprue. In order to provide a differential pressure casting device that acts quickly on the molten metal to be cast, can cast a metal casting quickly and precisely, and can smoothly perform the operation of inserting and removing the crucible into and from the crucible supporting means. is there.

A second object of the present invention is to provide a structure in which the stopper for securing the gap can be automatically moved in association with the rotation of the chamber without using any actuator. is there.

A third object of the present invention is that in the above-mentioned differential pressure casting apparatus, the lid portion and the container portion of the chamber can be opened and closed smoothly and the inside can be surely kept airtight. Is in the place of providing.

A fourth object of the present invention is to provide a differential pressure casting apparatus capable of accurately and easily centering any of the molds having different outer diameters in the differential pressure casting apparatus. .

[0010]

In order to achieve the first object, the first invention of the present application is a chamber supported so as to be rotatable from one of an upright position and an inverted position to the other, and a chamber. Gas suction / exhaust means for changing the inside of the crucible from a vacuum state or a pressurized state to the other, crucible support means for supporting the crucible so that its opening part is upward and detachable, and crucible heating for heating the crucible. In the differential pressure casting device comprising means and a mold support plate that supports the mold in a pressure-bonded state between the mold and the lid of the chamber, an opening for inserting the opening of the crucible in the mold support plate. A stopper that locks the opening of the crucible and secures a gap between the opening of the crucible and the sprue of the mold is provided in a disengageable state.
Further, the mold supporting plate is characterized in that a gas flow passage is formed which connects the void and the mold outer peripheral space.

In order to achieve the second object, the second invention of the present application is such that the stopper is slidably formed, and the stopper is slidable by its own weight when the chamber rotates from the upright position to the inverted position. It is configured to move to the stop position.

In order to achieve the third object of the third invention of the present application, the lid portion of the chamber is composed of a lid body and a lid outer case, and the container portion of the chamber is composed of a container body and a container outer case. The lid outer case is openably and closably coupled to the container outer case via a hinge, the lid main body is supported by the lid outer case under the pressing force of the first spring, and the mold pressing tool is supported by the second spring. It is supported by the lid main body in a suspended state, the spring constant of the first spring is larger than the spring constant of the second spring, the lid main body and the container main body are in a crimped state when the lid of the chamber is closed, and the mold is Is configured to be supported in a pressure-bonded state between the lid body and the mold support plate.

Further, in order to achieve the above-mentioned fourth object, the fourth invention of the present application is constituted so that the centering means for restraining the side circumference of the mold is capable of adjusting the restraining diameter.

[0014]

According to the first invention of the present application, the stopper provided on the mold supporting plate can secure a gap between the opening of the crucible and the gate of the mold when the chamber is inverted, and the gas provided on the mold supporting plate. The gap and the mold outer peripheral space can be brought into communication with each other by the flow passage. Therefore, for the molten metal transferred from the crucible to the gate of the mold when the chamber is inverted, the gas introduced into the chamber in a vacuum state is quickly guided to the upper surface of the molten metal, and the gas pressure causes the molten metal to flow into the mold cavity. It can spread every corner and can cast metal castings quickly and precisely. Since the stopper is provided so as to be engageable and disengageable, the crucible can be smoothly inserted and removed by opening the stopper.

According to the second invention of the present application, when the chamber is rotated from the upright position to the inverted position, the stopper is automatically moved to the locking position, which is convenient for use.

According to the third invention of the present application, since the lid body is elastically supported by the lid outer case with a certain degree of freedom, the opening / closing operation can be made smooth and the lid body is placed in the container body with good airtightness when the lid is closed. It can be crimped.

According to the fourth invention of the present application, centering can be accurately and easily performed on any of the molds having different outer diameters.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the entire embodiment of the present invention.
In FIG. 1, 1 is a machine base, 2 is a chamber supported by the machine base 1 so as to be rotatable from one of an upright position and an inverted position to the other, and 3 is an operation panel provided on the machine base 1. .

The chamber 2 comprises a container portion 4 and a lid portion 5, and the lid portion 5 is openably and closably coupled to the container portion 4 via hinges 6, 6.

FIG. 2 shows the chamber 2, its internal structure,
The structure for driving the chamber 2 in the forward and reverse directions is shown 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 exterior case 4b, and the lid part 5 of the chamber 2 is composed of a lid body 5a and a lid exterior case 5b. As described above, the container portion 4 and the lid portion 5 are joined together via the hinges 6 and 6. To be precise, the container outer case 4b and the lid outer case 5b are connected via the hinges 6 and 6. Are combined. Lid outer case 5b
Has a handle 7 and a locking means 8 for closing the lid (see FIG. 1), and the lid exterior case 5b is rotated around the hinges 6, 6 using the handle 7 to close the container exterior case 4b. At that time, it is automatically locked.

The lid body 5a is a first coil spring.
It is supported by the lid exterior case 5b in a state of receiving the pressing force 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 body 5a, and the collar portion 10 provided on the lower outer periphery of the lid body 5a and the lid exterior below the corresponding position. The stopper 11 provided on the inner circumference 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 portion 10 and the stopper 11 are locked while receiving the pressing force of the first spring 9. The lid main body 5a is supported by the lid exterior case 5b in a state where the lid main body 5a is provided with some degree of freedom of movement.

A guide member 12 is provided on the ceiling of the lid body 5a.
Mold pressing tool 13 guided and supported slidably up and down by
Is provided. The mold pressing tool 13 has a flange portion 13a at the upper end to prevent the mold pressing tool 13 from falling downward, and to prevent the coil spring from being interposed between the ceiling surface of the lid body 5a and the bottom surface of the mold pressing tool 13. The downward spring force is received by the second spring 14 that is formed. 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 horizontally. The rotating shaft 15 is supported by bearings 16 and 16 and receives a rotational driving force from a motor 17 via a transmission means such as a timing belt 18 to rotate forward and backward to move the chamber 2 from an upright position to an upright position, or It is rotated from the inverted position to the upright position, or a small reciprocating motion described later is performed. Further, a gas intake / exhaust passage 19 is formed in the axis center of the rotary shaft 15 so as to penetrate therethrough and communicate with the inside of the container body 4a to send air into the chamber 2 or remove air inside the chamber 2. Then, the inside of the chamber 2 can be evacuated. Reference numeral 20 is a pressure sensor for detecting the pressure inside the gas intake / exhaust passage 19.

A crucible 21 made of carbon is formed in the container body 4a of the chamber 2 with an opening 21 formed in a thick wall.
A crucible supporting means 22 is provided which supports the crucible so that it can be inserted and removed with a facing upward. The crucible supporting means 22 includes a crucible retort 22a made of ceramic, and the crucible retort 22.
a bottomed support cylinder 22b made of a heat insulating material for supporting a, and a base 22c supporting 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 housed and supported in a fitted state. When the crucible 21 is housed, the upper part of the crucible 21 is the 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 tube 22b. The crucible heating is a coil-shaped heating wire for heating the crucible 21. Means 23 are provided. The crucible heating means 23 heats the crucible retort 22 a, which in turn heats the crucible 21 therein to melt the metal 24 in the crucible 21. A temperature sensor 25 is a thermocouple that detects the temperature of the crucible 21.

A mold 26 is placed on the crucible supporting means 22.
A mold support plate 27 for supporting the mold with its gate 26a facing downward is fixed. As shown in detail in FIGS. 3 and 4, the mold support plate 27 has an opening 28 for inserting the opening 21 a of the crucible 21 and is locked in the opening 21 a of the crucible 21 to open the opening of the crucible 21. 21a and sprue 2 of mold 26
It has a stopper 29 that secures a gap P (see FIG. 10) between it and 6a.

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

The portion Q is composed of 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 wide portion with a gap provided in the metal plate portion 27a. Stopper piece 2 in the gap
9c is slidably inserted, and the rear rising portion 29d at the rear portion thereof projects to the outside from the window 29a. The window 29a is formed so as to fit the width of the rear rising portion 29d of the stopper piece 29c, determines the sliding direction of the stopper piece 29c, and also determines the sliding amount of the stopper piece 29c. The front standing portion 29e at the front part of the stopper piece 29c stands up to the height position of the upper surface of the heat insulating plate portion 27b, and the hook portion 2 which is bent inward at the tip thereof.
It has 9f.

As shown in FIG. 1, the stopper 29 is arranged so that the sliding direction of the stopper piece 29c automatically moves to the locking position by its own weight when the chamber 2 rotates from the upright position to the upright position. Is configured.
Of course, the stopper piece 29c is moved manually from one of the locking position (the position shown by the solid line in FIG. 4) and the open position (the position shown by the virtual line in FIG. 4) to the other by pinching the rear rising portion 29d with tweezers or the like. You can also let it. Then, the stopper 29 is locked to the opening 21a of the crucible 21 and the spout 26 of the mold 26 when the chamber 2 is rotated to the inverted position as shown in FIG.
It serves to secure a void P between the a and the a. Moreover, the point Q
The gas flow passage 30 formed by utilizing the above-mentioned structure serves to connect the void P and the outer peripheral space of the mold 26, and smoothly guide the air introduced into the chamber 2 to the sprue 26a.

As shown in FIG. 2, the mold 26 is provided with a metal ring 26b and a cavity 26c and a sprue 26a formed by the lost wax method.
The example shown is for forming a crown and has a cavity 26c.
Is formed in a shape suitable for it. This mold 26
Is centered by the centering means 31 whose restraint 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, four supporting pieces 31d, 31d. have. 4 support pieces 31
are fixed to the upper end of the inner peripheral wall of the container body 4a of the chamber 2 at regular intervals by welding or the like. A lower fixing ring 31c is fixed on the support pieces 31d, 31d ... And four restraining levers 31b, 31b ... Are pivotally supported at their base ends by pivots 31e. The lower fixed ring 31c has guide circular arc holes 31f, 31f ...
4 are formed, and each restraining lever 31b is formed with a long hole-shaped cam hole 31g oblique to the circumferential direction. An upper turning ring 31a is assembled on the restraining levers 31b, 31b ...
1a is an operation knob 31h, 31h with 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.

According to the centering means 31 constructed as described above, as shown in FIG. 5, the operating knob 31 is used.
By holding the h and turning the upper turning ring 31a as shown by the arrow R, the restraint levers 31b, 31b ... Can be swung as shown by the arrow S, and the tips of them can be moved to the mold 26. The centering of the mold 26 can be performed by contacting the inclining peripheral surface.

When the chamber 2 is closed, as shown in FIG. 2, the mold 26 is placed on the mold support plate 27 in a state of being elastically pressed by the mold pressing tool 13 with the gate 26a facing downward. Placed. At the same time, the lid body 5a and the container body 4a are joined to each other, and the O-ring 3 is arranged between the joining surfaces of the two.
The airtightness of the inside of the chamber 2 is maintained by 2.
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. 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. Since it can be determined naturally, and the two can be joined together without difficulty, the airtight state of the chamber 2 can be improved.

FIG. 7 is a block diagram showing the drive, gas intake / exhaust, and control relationship of this apparatus. In FIG. 7, 33 is a controller, 34 is a vacuum pump, 35 is an air 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, 4
Reference numeral 1 is a chamber position sensor, and 42 is a buzzer. Further, in FIG. 7, the solid line shows the electric system and the broken line shows the piping system.

As shown in FIG. 7, the inner space of the chamber 2 communicates with a vacuum pump 34 and an atmosphere introduction valve 35 via a gas suction / discharge passage 19 provided in the rotary shaft 15 and a pipe. These operations are controlled by the controller 33. The pressure in the gas intake / exhaust passage 19 is detected by the pressure sensor 20, and the signal is sent to the controller 33. The opening / closing of the lid 5 of the chamber 2 is detected by the lid switch 40, and the signal is sent to the controller 33. The rotation of the chamber 2 is performed by the forward / reverse rotation of the motor 17 which operates based on a command from the controller 33.
The rotational position of the chamber 2 is detected by the chamber position sensor 41, and its signal is sent to the controller 33. When the power switch 37 is turned on, the controller 33 is supplied with electric power from the power source via the power plug 36.
The heater (crucible heating means) 23 is controlled by the controller 33 and is heated by the electric current supplied from the heater transformer 39. The controller 33 controls the current of the heater 23 based on the 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 constructed as shown in FIG. 3a is a preheat indicator light, which flashes during preheating and lights up after preheating is completed. Reference numeral 3b is a status display section for notifying the start temperature, the melting temperature, the melting time, and the status of casting by blinking the lamp in the middle of the process, and turning on the lamp at the time of completion or completion, respectively. When a numerical value is selected, the corresponding part is informed by lighting. Reference numeral 3c is a numeral display portion for numerically displaying temperature or time. Reference numeral 3d is a course display portion, which displays the number of the selected course (program mode). 3e is a program data input button, which is used when setting a numerical value in a mode other than the existing program mode. A numeral 3f is a numerical value increase / decrease button, which can increase / decrease the numerical value shown in the numeral display portion 3c or the course display portion 3d.

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

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

The chamber 2 is in an 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,
Usually, the casting condition is set by selecting one of the courses (program mode) shown in the course display portion 3d. The controller 33 stores several kinds of data maps regarding the start temperature, the melting temperature, the melting time, and the casting processing time after preheating so as to be optimal for the kind of the metal material, and the operator operates the numerical value increase / decrease button 3f. Thus, the optimum course is determined by visually observing the numerical values on the course display portion 3d, and the set button 3g is turned on to confirm the optimum course. If there is no optimum one in the existing courses, the program data input button 3e is turned on to change the numerical values of the existing courses. First, the start temperature is displayed on the numerical display part 3c, and this is changed to the numerical value increase / decrease button 3
Increase / decrease with f and confirm this by turning on the set button 3g.

Subsequently, the melting temperature is similarly set, and subsequently, the melting time and the casting treatment time are also set similarly.

When the power is turned on with the casting conditions set as described above, the preheating step starts and the crucible heating means 23 generates heat to heat the crucible retort 22a, as shown in FIG. The temperature of the crucible installation section is once 1200
℃, then start temperature (eg 900
℃) to maintain the temperature. The entire temperature of the crucible retort 22a becomes substantially uniform in this preheating process.

The crucible 21 in which the metal material 24 is housed is placed in the chamber 2 which is maintained at the start temperature and is on standby.
Is inserted. The upper end of the opening 21a 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 step starts, the heat generation of the crucible heating means 23 intensifies, the temperature rises, and the crucible 21 is heated to a predetermined melting temperature (for example, 1400 ° C.). The buzzer 42 sounds when a predetermined time (melting time) has elapsed since the power was turned on.

Although the metal material 24 in the crucible 21 is generally completely melted by this, the state can be confirmed by the operator's visual observation or the like.

The present apparatus has a shaking button 3j so that the molten state of the metal material 24 in the crucible 21 can be easily visually confirmed. When the shaking button 3j is turned on, the controller 33 issues a command to the motor 17 to perform a 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.
Performs one reciprocating rotation of about m. As a result, the melted metal material 24 in the crucible 21 flows. By visually observing the flow state, the operator can easily determine whether or not the metal material 24 in the crucible 21 has completely melted.

The melting temperature is optimally set according to the metal type of the metal material 24 in the crucible 21.
In some cases, this does not work 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 you turn on the 2 degree plus heating button 3i, the melting temperature will be 20 ℃ against the original set value.
Can be increased. Of course, the temperature value raised by one ON is not limited to 10 ° C., and can be set arbitrarily.

When it is confirmed that the metal material 24 in the crucible 21 is completely melted as described above, the mold 26 is set on the mold support plate 27. After being centered by the centering means 31, the lid 5 is closed. The mold 26 is supported in a pressure-bonded state by receiving the spring force of the second spring 14 between the mold pressing tool 13 and the mold support plate 27, and the sprue 26a of the mold 26 and the opening 21a of the crucible 21 of the crucible 21 face each other. It will be in the state of doing. It is confirmed by the lid switch 40 that the lid 5 is closed, and then the casting start button 3k is turned on to start the casting process.

Then, based on the turning on of the casting start button 3k,
Simultaneously with the closing of the atmosphere introduction valve 35, the vacuum pump 34 is activated to suck and remove the air in the chamber 2 through the gas suction / exhaust passage 19 and the pipes for a predetermined time (for example, 23 seconds) to bring the chamber 2 into a vacuum state. The temperature of the crucible 21 is kept at the melting temperature during the vacuum suction period.

When it is confirmed by the pressure sensor 20 that the pressure in the chamber 2 has reached a predetermined vacuum degree (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 the hook 2
9f locks the opening 21a of the crucible 21 and prevents the crucible 21 from falling out of the crucible retort 22a. When the chamber 2 reaches the inverted position, the metal material 24 in the crucible 21 is poured into the sprue 26a of the casting mold 26 as shown in FIG.

In the conventional device, when the chamber 2 reaches the inverted position, the vacuum pump 34 is immediately stopped and the atmosphere introduction valve 35 is opened, but in that case, it becomes spherical. There is a risk that the metal material 24 sways, a gap is created in the passage to the cavity 26c, the atmosphere is introduced into the cavity 26c, and the vacuum state of the cavity 26c is impaired. 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 and the atmosphere introduction valve 35 is opened after a waiting time (for example, 1.5 seconds). Are controlled. By providing the waiting time in this way, the metal material 24 in the crucible 21 is in a stable state, and the passage to the cavity 26c can be surely blocked. The air (atmosphere) introduced from the atmosphere introduction valve 35 is introduced into the chamber 2 through the pipe and the gas intake / exhaust passage 19, and the air introduced into the chamber 2 is the gas flow passage 30 provided in the mold support plate 27. The crucible 2 by the stopper 29
1 smoothly reaches the upper surface of the metal material 24 on the sprue 26a through a gap P secured between the mold 1 and the mold 26, and the metal material 24 is moved to the corner of the cavity 26c by the pressure difference between the air pressure and the vacuum state of the cavity 26c. Push it to each other,
Precision casting is done. The pressure in the chamber 2 is returned to the atmospheric pressure in about 0.2 seconds by the introduction of the atmosphere, but since the air is smoothly introduced into the gate 26a of the mold 26, the precision casting is also the same. It is done smoothly in a short time.

From the operation of the vacuum pump 34 to the air introduction valve 35
At the time when the operation is switched to, the energization of 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 with which the cavity 26c is filled begins to solidify. When a predetermined casting time (for example, 10 seconds) has elapsed from the switching time 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 opposite direction. When the chamber position sensor 41 detects that the chamber 2 has reached the upright position, the buzzer 42 sounds,
Notify 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 work is started. When the temperature in the chamber 2 drops to the start temperature, the crucible heating means 23 is again energized, and the temperature in the chamber 2 is controlled to be maintained at the start temperature.

The present invention can be constructed in various modes other than those shown in the above embodiments. For example, in the above embodiment, the atmospheric pressure was introduced into the chamber 2 to make the inside of the chamber 2 a pressurized state.
It may be introduced inside. Further, as the stopper 29, a rotating type may be used instead of the sliding type.

[0052]

According to the first invention of the present application, even when the chamber is in the inverted position, a gap can be secured between the opening of the crucible and the gate of the mold, and the gas pressure at the time of introducing gas is the gate. Provided is a differential pressure casting device capable of promptly acting on a molten metal located at a position, capable of quickly and precisely casting a metal casting, and smoothly inserting / removing a crucible into / from a crucible supporting means. be able to.

According to the second invention of the present application, in addition to the effect of the first invention, the movement of the stopper for securing the gap is automatically linked with the rotation of the chamber without using any actuator. Can be configured to do so.

According to the third invention of the present application, in addition to the effects of the first invention or the second invention, it is possible to smoothly open and close the lid portion and the container portion of the chamber and to reliably keep the inside airtight. It is possible to provide a differential pressure casting device that can be used.

According to the fourth invention of the present application, in addition to the effects of the first invention or the second invention, there is provided a differential pressure casting apparatus which can accurately and easily perform centering of any of molds having different outer diameters. Can be provided.

[Brief description of drawings]

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

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

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

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

FIG. 5 is a plan view showing centering means.

FIG. 6 is an exploded perspective view of the 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 4 container part 4a container body 4b container exterior case 5 lid part 5a lid body 5b lid exterior case 6 hinge 9 first spring 13 mold pressing tool 14 second spring 19, 34, 35 gas suction and discharge means 21 crucible 21a crucible opening Part 22 Crucible support means 23 Crucible heating means 26 Mold 26a Mold gate 27 Mold support plate 28 Opening of mold support plate 29 Stopper 30 Gas flow passage 31 Centering means P Void

Claims (4)

[Claims] 1. A chamber supported so as 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 suction / exhaust means, a crucible support means for supporting the crucible so that the opening part thereof can be inserted and removed, a crucible heating means for heating the crucible, and a mold with its gate down, and a lid part of the chamber. In a differential pressure casting apparatus including a mold support plate that supports the crucible in a state, an opening for inserting the opening of the crucible is provided in the mold support plate, and the opening of the crucible is locked by the opening of the crucible and the gate of the mold. A differential pressure casting apparatus characterized in that a stopper for securing a gap is provided between the mold and the mold in a detachable manner, and a gas flow passage that connects the gap and the outer peripheral space of the mold is formed in the mold supporting plate. 2. The stopper is slidably formed,
2. The differential pressure casting apparatus according to claim 1, wherein the stopper slides in a sliding direction so that when the chamber rotates from an upright position to an inverted position, the stopper moves by its own weight to a locking position. 3. The lid portion of the chamber is composed of a lid body and a lid outer case, the container portion of the chamber is constituted of a container body and a container outer case, and the lid outer case is opened and closed via a hinge to the container outer case. And the mold pressing tool is supported by the lid main body in a state of being suspended by the second spring. The spring constant is larger than the spring constant of the second spring, and the lid body and the container body are in a crimped state when the lid portion of the chamber is closed, and the mold is supported in a crimped state between the lid body and the die support plate. The differential pressure casting apparatus according to claim 1, which is configured as described above. 4. The centering means for restraining the side circumference of the mold is capable of adjusting the restraining diameter.
The differential pressure casting device described.