JP2002096156A - Molten metal pouring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove occurrence of stain and damage on a peep glass window, and to make it possible to adjust the opening state of the lower part of a crucible while recognizing the state inside the crucible, thus removing inferior casting. SOLUTION: This molten metal pouring apparatus is of a vessel form with its upper part being opened and the whole body thereof is vertically divided, and comprises a crucible with a flange provided on the outer periphery of the opening of respective divided parts, a melting chamber hermetically sealed with a chamber cover provided with a peep glass window on the upper part thereof housing the crucible with high-frequency coil encircling in a cylindrical form around it, and a casting chamber housing a cast mold into which the molten metal flowing out from the bottom part of the crucible is poured. Further, in the melting chamber are provided a fixed supporting body that hangs down the crucible while supporting the flange, and a movable supporting body and a rod-driving means that open the crucible from the bottom into the form of a wedge by supporting or releasing the support of the flange of the crucible. In this case, the crucible is so made as to open itself from the bottom by its own weight in accordance with the quantity of displacement of the movable supporting body.

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 injecting the molten metal into a mold.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of a conventional apparatus, and the conventional structure will be described with reference to FIG. FIG. 4a is a side sectional view,
FIG. 4b is a plan view. A side shows a state where a crucible to be described later is closed, and B side shows a state where the crucible is opened.
It is composed of a melting chamber 1 and a casting chamber 2 and is sealed by an O-ring 20. To reduce or pressurize these, the chamber is closed by a chamber cover (not shown). There is a window glass at the top. The molten metal in the crucible is dropped into the gate 2a and cast into the mold 7 by pressurizing with an inert gas. Generally, the amount of the alloy used for this kind of precision casting is several grams. It is a small amount of tens to tens of grams. Therefore, the crucible 10 is divided into two crucible pieces 10a and 10b, and the upper surface of the outer periphery of the flange 11 of the crucible is pressed by the tip 22 of the crucible opening / closing body 21.
Are formed together so as to accommodate the metal to be melted. With the high-frequency power applied to the high-frequency coil 19, the metal to be melted undergoes induction heating and melts, and the crucible bottom 1
When the molten metal was dropped from 2, the crucible was opened with the following structure. In order for the tip 22 of the crucible opening / closing body to release the pressing, an opening / closing arm 30 which can be slid horizontally on the crucible support 18 first as a whole has a U-shape.
The opening / closing arm is slid from the wide restraining portion 30a to the narrow opening portion 30b, and the spring 28 advances the flange fixing portion 23 inward by using the component force to push the flange outer edge. The crucible whose outer edge is pressed is opened in a wedge-shaped manner from the crucible bottom 12 with the upper end of the divided surface as a fulcrum by the action of the lever, and the molten metal instantly drops.

[0003]

When the amount of the molten metal is large, when pressurizing with an inert gas for pressure casting,
The sudden drop of the molten metal causes strong collision with the inner wall of the crucible, causing turbulence, and the molten metal also scatters upward. Crucible 10
The lower surface of the observation window glass for direct observation or sensor detection provided on the chamber cover sealed above the melting chamber 1 surrounding the high-frequency coil 19 and the high-frequency coil 19, the metal fine powder scattered at this time adheres and becomes dirty, and the crucible becomes dirty. There were drawbacks that could not be monitored. In addition, since switching between vertical rotation and reciprocation of the crucible opening / closing body is performed by the component force of the portion where the width of the arm changes, there is a disadvantage that the engagement portion is severely worn, and problems such as catching are likely to occur. Was. It is an object of the present invention to provide a molten metal injection device that eliminates these disadvantages.

[0004]

In order to achieve the above object, a crucible is provided which is vertically divided in a container shape opened upward, and which is provided with a flange outside the edge of the opening in each of the divided portions. And a high-frequency coil surrounding the crucible in a cylindrical shape. A melting chamber closed with a chamber cover provided with a sight glass on the upper surface and a mold into which the molten metal flowing out from the bottom of the crucible is injected are stored. The melting chamber comprises the crucible, two types of crucible supports for supporting the flange of the crucible, a fixed support, a movable support, and a rod driving means; and a pair of fixed supports. Is in contact with the lower surface of the flange of the crucible on the upper surface, the crucible is supported by the contact point, and a pair of movable supports are arranged at orthogonal positions on the same horizontal plane as the fixed support. When the movable support comes in contact with the lower surface of the flange on the outer periphery of the crucible with a binding force by a spring force, and when the tip of the horizontal portion of the movable support is retracted downward by the rod driving means so as to release the binding force, the movable support is retracted. The crucible's flange supporting position is lowered according to the displacement amount, and the crucible's flange is tilted, so that the crucible lowered by the fixed support can be opened in a wedge-like manner by the gravity of the built-in molten metal. The molten metal flows out of the opening at the bottom of the crucible and flows into the mold.

According to a second aspect of the present invention, there is provided a flange retainer formed so as to have a function as an automatic return device for the position of the crucible after the molten metal flows out. When a flange holder having a wedge-shaped convex portion presses the upper surface of the crucible from above, the flange slides on a flat surface and finely adjusts on a horizontal surface to guide to an appropriate position.

According to the third aspect, the pair of movable supports abut on the lower side surface of the crucible, and the crucible is closed and integrally supported by a spring so as not to open in a wedge shape from the bottom. When the rod is driven by a force opposing the spring of the movable support, the contact retreats on the lower side surface of the crucible and the restraint is released.
Since the crucible tries to return to the free position with the support portion lowered by the fixed support as a fulcrum, the flange surface is inclined to both sides to the retracted position of the movable support, and can be opened from the crucible bottom in a wedge shape.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention is shown in FIGS.
This will be described with reference to FIG. FIG. 2 is a side view obtained by rotating the side view of FIG. 1 by 90 degrees. In FIG. 1, A side shows the state where the crucible is closed, and B side shows the state of the movable support in which the crucible is opened. The side C in FIG. 2 shows the state of the movable support when the crucible is open, and the side D in FIG. 2 shows the state of the movable support when the crucible is closed. The melting chamber 1 for heating the crucible 10 is united with the casting chamber 2 and sealed with an O-ring 20. In the upper part of the melting chamber 1, a pair of convex fixed supports 3 are provided from a crucible support frame 18 having a wide opening, and a flange 1 of the crucible is provided.
The crucible 10 is hung down with the lower surface of the crucible 10 as a supporting point. Above the melting chamber 1, a chamber cover 8 having a viewing glass 9 is sealed with an O-ring 26 and hermetically closed. The lower part of the melting chamber 1 is provided in a shape in which a high-frequency coil 19 surrounds the crucible 10. When high-frequency power for heating is supplied to the high-frequency coil 19, the metal to be melted in the crucible 10 is heated and melted. As shown in FIG. 2, the crucible 10 is composed of a crucible piece 10a and a crucible piece 10b that are vertically divided into two from a division surface 15. Crucible 1
A pair of movable supports 4 that support the lower portion 13 immediately below the flange
Are provided at substantially orthogonal positions on the same plane as the pair of fixed supports 3. The movable support 4 is formed by bending a seesaw, and is composed of a horizontal part and a vertical part. When the rod 6 presses the vertical part, the horizontal part of the movable support is forced by the spring 5 indicated by an arrow. 1 and the tip is pushed down, the restraining state of the lower portion 13 immediately below the flange of the crucible 10 is released, and the crucible is moved to the B side in FIG. 1 (C in FIG. 2).
Side). When the pressing of the rod 6 is released, the force of the spring 5 overcomes and the movable support returns to the horizontal state from the inclination, and the lower portion 13 immediately below the flange of the crucible is restrained as shown in the state on the A side.

The rod driving means 61 is an electromagnet, and pushes the rod 6 directly connected to the movable iron core 62 of the electromagnet in the direction of the arrow B, but when the value of the current supplied to the coil of the electromagnet is reduced, the force of the spring is applied to the electromagnet. The rod 6 returns to its original position, as shown on the A side. Thus, the state in which the force of the spring 5 returns the horizontal portion of the movable support 4 to its original state is the crucible piece 10a and the crucible piece 1
0b is closed, but when the rod of the electromagnet of the rod driving means 61 is energized and the rod 6 is pressed to overcome the force of the spring 5, the crucible 10 tilts in the direction in which the restraint is released. . This is effective even if the rod driving means 61 is an air cylinder because the same function is exhibited.

Next, the relationship between the opening and closing of the crucible 10 and the molten metal will be described. The metal to be melted is put into the crucible 10 with the crucible piece 10a and the crucible piece 10b closed by the force of the spring 5. The chamber cover 8 is closed, the air in the melting chamber 1 and the casting chamber 2 is replaced with an inert gas, and high-frequency power is supplied to the high-frequency coil 19 to heat and melt the metal to be melted. Next, the electromagnet of the rod driving means is energized so that the rod 6 is pressed by overcoming the force of the spring 5, and the movable support 4
When the tip of the horizontal portion of the crucible is inclined downward and the pressing force on the lower portion 13 immediately below the flange of the crucible 10 is released, the crucible 10 is opened from the lower portion 12 in a wedge shape by the gravity of the molten metal and the weight of the crucible 10. The molten metal falls from the lower part 12 of the crucible, passes through the gate 2 a of the casting chamber 2, and is cast in the mold 7. At this time, the driving means 61 in a slightly weak direction balanced with the force of the spring 5 so that the opening speed of the lower portion 12 of the crucible becomes slow so that the molten metal does not fall too fast to cause turbulence in the crucible. The value of the current flowing through the electromagnet is adjusted. This allows the crucible to open and close freely.

Regarding claim 2, as shown in FIG.
A flange retainer 31 formed to have a function as an automatic device for automatically returning the position of the crucible after the molten metal flows out is provided. The flange holder 31 having a wedge-shaped convex portion corresponding to the wedge-shaped notch of the flange is pulled up above the upper surface of the crucible when dropping the molten metal, but the molten metal is put into the crucible and set. When pressing, press down from above the crucible flange as shown by the arrow in FIG. At this time, the wedge-shaped projection serves as a guide, and the flange slides on a plane, finely adjusts on a horizontal plane, fits into the notch, and guides the crucible 10 to an appropriate position. In the above description, as shown in FIGS.
Is set at a position just above the movable support 4.

According to a third aspect of the present invention, the contact portion of the movable support to the crucible is disposed so as to be on the lower side surface of the crucible. The crucible pieces 10a, 10b are closed and integrally supported by being sandwiched between the pair of opposing positions on the lower side of the crucible, and the non-restrained state in which the crucible is opened from the lower part into a wedge shape by releasing the support at the contact retreat position. This is realized by the position of the rod 6.

[0012]

The bottom of the crucible can be freely opened and closed while controlling the amount of fall of the molten metal, so that the molten metal is placed in a vertically divided two-part crucible in a container shape that opens upward. When falling from the bottom of the crucible, the falling speed could be made slow enough to prevent the molten metal from scattering up to the sight glass provided above. Furthermore, in the conventional crucible opening / closing body for opening the bottom of the crucible, the switching between vertical rotation and reciprocation is performed by the component force of the portion where the width of the arm is changed. Defects such as cracks and catches were eliminated, but the problem was solved with a simple and clear crucible opening and closing structure. According to the present invention, since the electric control can be performed as described above, it is possible to eliminate the occurrence of stains on the sight glass as in the past, and it is possible to adjust the opening degree while recognizing the inside of the crucible and eliminate casting defects. In conjunction with the recognition inside the crucible, heating power can be controlled, contributing to energy saving. In addition, the conventional crucible opening / closing body is eliminated from the cause of abrasion and catching, and the reliability and maintenance during operation are greatly improved, so that the apparatus is economical, so that the industrial value is great.

[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 a side view of FIG.

FIG. 3 is a longitudinal sectional view of a molten metal injection apparatus showing another embodiment of the present invention.

FIG. 4 shows the structure of a conventional molten metal injecting apparatus, wherein FIG. 4A is a longitudinal sectional view and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Melting room 2 Casting room 2a Gate 3 Fixed support 4 Movable support 5 Spring 6 Rod 61 Rod drive means 7 Mold 8 Chamber cover 9 Viewing glass 10 Crucible 10a Crucible piece 10b Crucible piece 11 Flange 12 Crucible bottom 13 Just below flange 14 Notch 15 Splitting surface 18 Crucible support frame 19 High frequency coil 20 O-ring 26 O-ring 31 Flange holder 62 Movable iron core

Claims (3)

[Claims] 1. A crucible which is vertically divided in a container shape opened upward and which is provided with a flange outside the edge of the opening of each divided portion, and a high-frequency coil which surrounds the crucible in a cylindrical shape. A melting chamber closed and sealed by a chamber cover provided with a sight glass on the upper surface, and a casting chamber containing a mold into which molten metal flowing out of the bottom of the crucible is injected, wherein the crucible is placed in the melting chamber. A movable support having a fixed support for hanging the crucible by supporting the flange of the crucible, a movable support for supporting and releasing the flange of the crucible to open the crucible from the bottom in a wedge shape, and a rod driving means The molten metal pouring apparatus according to claim 1, wherein the crucible is opened from its bottom by its own weight according to the displacement of the support. 2. The molten metal pouring apparatus according to claim 1, further comprising a flange presser having a wedge-shaped projection corresponding to a notch formed in the crucible so as to have a slight angle with the crucible dividing surface. 3. The movable support contacts the lower side of the crucible,
2. The molten metal pouring apparatus according to claim 1, wherein the crucible is a movable support that is integrally closed so as not to open in a wedge shape, or is a movable support that retreats from contact and releases the support to open the crucible in a wedge shape from the bottom.