JP2001179423A - Molten metal pouring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molten metal pouring apparatus in which a lower portion of a crucible can be opened/closed by controlling the opening thereof so that the flow-out speed can be smoothed and a window glass is not stained by solving problems that a conventional molten metal pouring apparatus has an opening/closing structure to mechanically press an upper side of the crucible, the lower portion of the crucible is instantaneously opened to drop the molten metal, the turbulence is caused thereby, a peep glass of the apparatus is stained, the inside of the apparatus cannot be monitored, and defective casting occurs. SOLUTION: The molten metal pouring apparatus comprises the crucible to be gradually opened by an electromagnet to provide the pulling-in attraction while balancing a rod to press a portion immediately below an upper flange of the crucible is balanced with the pushing force of a spring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an apparatus for melting a metal in a precision casting machine used for dental use and pouring the molten metal into a mold.

[0002]

2. Description of the Related Art FIG. 3 shows the structure of a conventional apparatus. In addition,
In FIG. 3, the A side shows a state where a crucible to be described later is closed, and the B side shows a state where the crucible is opened. Decompression chamber 1
And a casting chamber 2. The molten metal is dropped into a gate 2a, and is cast in a mold 7 by pressurizing with an inert gas. Generally, an alloy used for this type of precision casting is , The amount of which is as small as several grams to several tens grams. Therefore, the crucible 10 is divided into two parts 10a and 10b, and the upper surface of the outer periphery of the flange 11 is pressed down by the tip 22 of the crucible opening / closing body 21.
5 are aligned with each other and formed into one piece, and the metal to be melted is accommodated. When the high-frequency coil 19 melts the metal to be subjected to induction heating and drops it from the bottom, the crucible is opened with the following structure. Tip 22 of crucible opener
First, the arm is moved from the wide restraining portion 30a of the arm to the narrow opening portion 30b so that the pressure is released.
By utilizing the component force, the spring 28 advances the flange fixing portion 23 inward and presses the flange outer edge. The crucible pressed against the outer edge of the flange opens in a wedge-shaped manner from the bottom of the crucible with the upper end of the divided surface as a fulcrum by the action of the lever, and the molten metal instantly drops. When the amount of the molten metal is large and the gas is pressurized, the sudden drop of the molten metal strongly collides with the inner wall of the crucible to cause turbulence, and the molten metal scatters upward. The bottom surface of the observation window glass for direct observation or sensor detection provided on the chamber cover sealed above the decompression chamber surrounding the crucible and the furnace body, the fine metal powder scattered at this time adheres and becomes dirty, and the crucible is monitored. There was an inability to do so. In addition, since the switching between the vertical rotation and the reciprocation of the crucible opening / closing body is performed by the component force of the arm width changing part, there is a drawback that the engaging part is severely worn and defects such as catching are likely to occur. there were.

[0003]

When the molten metal falls from the bottom of the crucible into the vertically divided two-piece crucible in the shape of a container opened upward, the molten metal is melted up to the sight glass provided above. An object of the present invention is to form a molten metal pouring device that can freely open and close the bottom opening of a crucible while controlling the amount of molten metal falling, with the aim of slowing the falling speed to the extent that metal does not scatter. Furthermore, since the structure is such that the switching between up and down rotation and reciprocation is performed by the component force of the arm width changing part, such as the conventional crucible opening and closing body for opening the bottom of the crucible, wear at the engaging part SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the disadvantages such as cracking and catching and to solve the problem with a simple and clear crucible opening / closing structure.

[0004]

Means for Solving the Problems In order to achieve the above object, the whole is vertically divided in a container shape which is closed by a chamber cover provided with a sight glass on the upper surface and opened upward, and each of the divided A crucible provided with a flange outside the edge of the opening of the portion, a heat-resistant partition wall surrounding the crucible in a cylindrical shape, a decompression chamber containing a high-frequency coil, and a mold into which molten metal flowing from the bottom of the crucible is injected. A crucible, a crucible support for supporting a flange of the crucible,
Always contact the crucible directly below the crucible flange from the side,
A rod for closing the crucible dividing surface and a rod driving means for reciprocating the rod constitute a molten metal injection apparatus. A notch with a slight angle to the crucible dividing surface is provided on the crucible flange, and the crucible is fished on a wide-mouthed crucible support so that the lower part of the notch is opened by its own weight in a wedge-like manner while the lower ends are in contact with each other. As if it had been lowered. The wedge-shaped opening operation of the lower part of the crucible utilizes the angle formed by the dividing plane and the vertical plane when the crucible is suspended at the crucible supporting part. That is, the position of the center of gravity of the crucible piece lowered like a pendulum is stopped just below the crucible support position of the crucible support.

[0005] According to claim 2, as the rod driving means, a spring for pressing a portion immediately below the flange of the crucible,
It is composed of an electromagnet that is drawn in the opposite direction to the pressurization, and a movable core that is attracted to the electromagnet and fixed to a rod. When the electromagnet is energized, the rod is retracted, contacts the lower end of the notch, and the lower portion opens like a wedge. When the energization of the electromagnet is stopped, the rod presses the portion immediately below the flange by the pressing force of the spring, and the crucible closes with the divided surfaces in contact with each other. The pressing force of the spring is balanced, and fine adjustment is made electrically, such as gradually increasing the pulling force of the rod, to freely adjust the degree of opening of the crucible.

According to the third aspect, the inside of the coil bobbin of the electromagnet, which is a component of the rod driving means, constitutes a part of the inside of the decompression chamber, and the operating mechanism in the hermetically maintained decompression chamber is electrically connected from the outside. It was configured as an activated molten metal injector.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIG. In FIG. 1, A side shows a state where the crucible is closed, and B side shows a state where the crucible is opened. 1
Is a decompression chamber for heating the crucible 10 and is integrated with the casting chamber 2 and sealed with an O-ring 20. At the upper part of the decompression chamber 1, a crucible support 6 having a wide opening is provided, and the crucible 10 is hung with the lower surface of the flange 11 as a support point. Above the crucible, a chamber cover 8 having a viewing window glass 9 is sealed with an O-ring 26 and hermetically closed. The lower part of the decompression chamber 1 is formed so that a high-frequency coil 19 is provided around the heat-resistant partition wall 18, and when a high-frequency power for heating is supplied thereto, the metal to be melted in the crucible 10 is heated and melted. Have been. The crucible 10 is vertically divided into two parts from a division surface 15 and is composed of a crucible piece 10a and a crucible piece 10b. The lower end of the notch 14 provided in the upper flange 11 is used as a contact point, and the lower part is wedge-shaped. It is hung down in an open shape and becomes a rest position. This rest position is a position where the center of gravity of the crucible piece is directly below the crucible support point, the crucible dividing surface 15 forms an angle with the vertical surface, and the bottom portion 12 is open.

When the rod 5 receives the pressing force of the spring 4 and presses the lower portion 13 immediately below the flange from both sides, the metal to be melted is put into the crucible 10 in a state where the crucible pieces are closed, and the chamber of the decompression chamber 1 is set. After the cover 8 is closed and the inside of the chamber is decompressed, the metal is melted by high-frequency heating by replacing with an inert gas or the like. Then, the rod 5 is drawn in by an electromagnet and the bottom 12 of the crucible is opened. It is cast in the mold 7 in the chamber 2. At this time, the crucible pieces 10a are so arranged that the falling speed is not too high to cause turbulence in the crucible.
The crucible piece 10b pulls in the rod 5 pressing the flange 13 directly below the upper part of the crucible, and opens the lower part of the crucible by its own weight with the notch of the crucible 10 as a fulcrum. As a result, it was possible to eliminate the conventional impact of opening and closing the crucible purely mechanically.

The interior of the coil bobbin 32 surrounding the movable core 34 fixed to the rod 5 is formed in the same space as the decompression chamber 1 to facilitate sliding of the movable core, and the rod 5 is hermetically sealed with an O-ring or the like. To prevent the sliding resistance from increasing. The electromagnet 3
A bobbin partition 35 was provided on the bobbin 32 of the coil 33 at the end of the iron core 31 to shield the decompression chamber space from the external space.

[0010]

According to the present invention, since the electric control can be performed as described above, it is possible to eliminate the contamination of the viewing window glass when the molten metal falls when the crucible is opened and closed as in the prior art, and to recognize the inside of the crucible. While adjusting the degree of opening, it was possible to eliminate casting defects and to control the heating power in conjunction with recognition inside the crucible, contributing to energy savings. In addition, the cause of wear and catch of the conventional pure mechanical crucible opening / closing body is eliminated, and the reliability and maintenance during operation are greatly improved, and the apparatus is economical.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a molten metal injection apparatus showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a longitudinal sectional view showing the structure of a conventional molten metal injection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decompression chamber 2 Casting room 3 Electromagnet 4 Spring 5 Rod 6 Crucible support 7 Mold 8 Chamber cover 9 Viewing glass 10 Crucible 10a Crucible piece 10b Crucible piece 11 Flange 12 Bottom part 13 Immediately below flange 14 Notch part 15 Splitting surface 18 Heat-resistant partition wall 19 High frequency coil 20 O-ring 26 O-ring 31 Iron core 32 Coil bobbin 33 Coil 34 Movable iron core 35 Bobbin partition

Claims (3)

[Claims] 1. A container which is hermetically sealed by a chamber cover provided with a sight glass on the upper surface, is vertically divided in a container shape opened upward, and a flange is provided on an outer side of an edge of the opening in each of the divided portions. A vacuum chamber containing a crucible, a heat-resistant partition wall surrounding the crucible in a cylindrical shape, and a high-frequency coil;
A casting chamber containing a mold into which the molten metal flowing out of the bottom of the crucible is injected;
A crucible, a crucible support that supports the flange of the crucible, a rod that is always in contact with a portion directly below the flange of the crucible from the side to close the crucible dividing surface, and a rod driving unit that reciprocates the rod. Molten metal injection device composed of: 2. The rod driving means includes a spring for pressing a portion immediately below a flange of the crucible, an electromagnet drawn in a direction opposite to the pressing, and a movable core attracted to the electromagnet and fixed to a rod. 2. The molten metal injection apparatus according to claim 1, wherein the size of the opening of the crucible is freely adjusted by balancing the pressing force of the spring to gradually increase the retraction force. 3. A molten metal injection apparatus in which the inside of a coil bobbin of an electromagnet, which is a component of a rod driving means, forms a part of the inside of a decompression chamber.