JP2019000896A - Casting apparatus - Google Patents

Abstract

To provide a casting apparatus capable of cooling one whose center tree is connected with castings, such as rings (finger rings), like branches nearly uniformly depending upon a region and of manufacturing precious metal products excellent in quality and appearance.SOLUTION: A casting apparatus for precious metal products comprises a housing for the casting apparatus, a permeable support table that mounts within the housing a gypsum mold arranged with a predetermined spacing from a wall surface of the housing, gates for the gypsum mold, a bottom surface of the support table, and a plurality of ejection nozzles that respectively eject compressed air toward the wall surface of the support table. The ejection nozzles arranged in the wall surface are arranged in a tangential direction of the housing inner wall to thereby cause a swirl flow along an outer periphery of the gypsum mold.SELECTED DRAWING: Figure 2

Description

The present invention relates to a casting apparatus used for manufacturing various precious metal products using the lost wax method.

The current status of the lost wax casting method in the manufacturing process of precious metal products is as follows.
The mold in the lost wax casting method is for obtaining a target shape by burying a wax reflecting a prototype in gypsum and casting a molten metal into a cavity formed by burning.
The mold shape in the precious metal industry is mainly cylindrical and has a feeder part at the center, and a casting such as a ring (ring) is connected to a center tree extending from the center tree.
At the site of casting precious metal products, after pouring with a casting machine, it is currently taken out from the casting machine and naturally cooled (slow cooling), which causes the deterioration and quality due to casting defects. Defects such as instability have occurred.

The mold, gypsum, has poor thermal conductivity, and it takes a long time to cool because it is centered on a thick center tree with a large heat capacity. Natural cooling gradually cools from the outside, but it takes time to solidify to the center of the mold. Therefore, there is a problem that the cooling rate can be different for each part in the mold, the casting quality is poor, and the quality is not stable.
Such gas defects and shrinkage cavities caused by expansion and contraction during solidification, which are casting defects, are mainly generated in the gaps of the dendrite structure. That is, in the present situation where gradual cooling is performed by natural cooling, the closer to the center of the mold, the slower the cooling rate, so that the dendrite secondary arm interval becomes wider. If the dendrite secondary arm interval is wide, the size of the nest and the compound is increased accordingly.

In order to solve the above problems, attempts have been made to forcibly cool instead of natural cooling.
For example, in the invention of Japanese Examined Patent Publication No. 3-64220 (see Patent Document 1), a method of forcibly cooling with water after natural cooling for a while is disclosed in Japanese Patent Publication No. 4-20699 (refer to Patent Document 2). A method of forcibly cooling the mold by spraying a cooling fluid from the outside until a predetermined temperature higher than the temperature at which the solid solution is generated is employed.

Japanese Examined Patent Publication No. 3-64220 Japanese Examined Patent Publication No. 4-20699

However, in the method of forcibly quenching the entire mold as described above, the cooling rate can be different for each part in the mold, and it is far from solving the problem that the quality of the casting is poor and the quality is not stable. There was a thing.
Therefore, the object of the present invention is to be able to cool the castings such as rings (rings) that are connected to the center tree like a branch almost uniformly according to the part, and is excellent in quality and appearance. An object of the present invention is to provide a casting apparatus capable of producing noble metal products and the like.

In order to solve the above-mentioned problems, a casting apparatus for precious metal products according to the present invention includes a housing for the casting apparatus and a gypsum mold installed in the housing at a predetermined interval from the wall surface of the housing. A support base, a gypsum-shaped gate, a bottom surface of the support base, and a plurality of injection nozzles for injecting compressed air toward the inner wall surface of the housing. It is installed toward the tangential direction of the inner wall, and a swirling flow is generated along the outer periphery of the gypsum mold.

In the casting apparatus for precious metal products of the present invention, the plurality of injection nozzles for injecting the compressed air inject the compressed air toward the bottom surface of the support base and the inner wall surface of the housing, respectively, It is also characterized in that an upward flow swirling along is generated.

In the casting apparatus for precious metal products of the present invention, the plurality of injection nozzles for injecting the compressed air inject each of the injection nozzles into the air supply unit so that a predetermined amount of air can be injected from the air supply unit. It is also characterized in that the start time and end time can be set individually.

According to the invention of the casting apparatus of claim 1, it is provided with a gypsum-shaped gate, a bottom surface of the support base, and a plurality of injection nozzles that respectively inject compressed air toward the wall surface of the support base. Since the installed injection nozzle is installed in the tangential direction of the inner wall of the housing, and a swirling flow is generated along the outer periphery of the gypsum mold, a casting such as a ring (ring) is formed like a branch in the center tree. What is connected can be cooled almost uniformly according to the part, and a precious metal product excellent in quality and appearance can be manufactured.
In addition, labor costs associated with manual cooling work can be suppressed, and productivity can be significantly improved.

According to the invention of the casting apparatus of claim 2, the plurality of injection nozzles for injecting the compressed air inject the compressed air toward the bottom surface of the support base and the wall surface of the support base, respectively. Since the upward flow swirling around the outer periphery of the mold is generated, the entire gypsum mold can be cooled very efficiently.

According to the invention of the casting apparatus of claim 3, each of the plurality of injection nozzles for injecting the compressed air can be supplied to the air supply unit for each injection nozzle so that a predetermined amount of air can be injected from the air supply unit. Since the injection start time and end time can be set individually, each part of the gypsum mold can be efficiently cooled.

It is a schematic perspective view which shows embodiment of the casting apparatus for manufacturing the noble metal product of this invention. It is the schematic sectional drawing. It is a schematic sectional drawing which shows a modification. It is a schematic sectional drawing which shows that compressed air turns into the upward flow which turns. It is a schematic sectional drawing which shows the state by which the gypsum type | mold is arrange | positioned in the compressed air used as the ascending upward flow. It is a central perspective schematic sectional view of the state before the assembly showing the relationship between the gypsum mold and the casting apparatus. It is a center perspective schematic sectional drawing of the state which assembled both. It is for demonstrating a gypsum type | mold, (a) is a schematic perspective view before the assembly | attachment of a gypsum type | mold and a perforated holding cylinder (perforated stainless ring), (b) is the schematic perspective sectional view. (A) is a schematic perspective view of a state where a gypsum mold and a perforated holding cylinder (perforated stainless ring) are assembled, (b) is a schematic perspective cross-sectional view thereof, and (c) is a schematic perspective cross-sectional view of a state further filled with molten metal. FIG.

Embodiments of the casting apparatus of the present invention will be described below with reference to the drawings.
1 to 7 show an embodiment of the casting apparatus of the present invention, and FIGS. 8 and 9 show a gypsum type example.
1 to 7, a noble metal product casting apparatus 11 according to this embodiment includes a container-shaped housing 12 having an inner wall 12a and an outer wall 12b, and a predetermined distance from the wall surface of the housing 12 in the housing 12. A support base 13 having air permeability, mounted with a gypsum mold 21 installed at a distance, a gate 21a of the gypsum mold 21, a bottom surface 13a of the support base 13, and an inner periphery of the inner wall 12a of the housing 12 And a plurality of injection nozzles 14 for injecting compressed air toward the surface.
And since the injection nozzle 14 installed on the wall surface of the inner wall 12 a is installed toward the tangential direction of the inner wall 12 a of the housing 12, a swirling flow is generated along the outer periphery of the gypsum mold 21.

In this way, the spray nozzle 14 installed on the wall surface is installed in the tangential direction of the inner wall 12a of the housing 12 so that a swirl flow is generated along the outer periphery of the gypsum mold 21. Since a cast such as a ring (ring) like a branch is connected to the center tree, it can be cooled almost uniformly according to the part, so we manufacture precious metal products with excellent quality and appearance. be able to.

The plurality of injection nozzles 14 for injecting the compressed air are preferably configured to inject compressed air toward the bottom surface 13a of the support base 13 and the inner wall 12a of the housing 12, respectively. An airflow such as a spiral swirling and rising along the outer periphery of the mold 21 is generated.
Therefore, the entire gypsum mold 21 can be cooled very efficiently.

In the casting apparatus of the embodiment shown in FIG. 2, each of the plurality of injection nozzles 14 for injecting the compressed air is injected into the air supply unit 14a so that the air of a predetermined wind pressure can be injected from the air supply unit 14a. A pressure regulator 14b for each nozzle 14 is provided.

In the casting apparatus for precious metal products according to the present invention, each of the plurality of injection nozzles 14 for injecting the compressed air can respectively inject a predetermined amount of air from the air supply unit 14a to the air supply unit 14a. An injection time setting means 14c that can set an injection start time and an end time for each injection nozzle 14 is provided.
As shown in FIG. 3, the injection time setting means 14c converts the predicted value of the temperature change into the injection time, and controls the open / close valve to inject the compressed air from the injection start time to the end time.
Therefore, each part of the gypsum mold 21 can be efficiently cooled to a predetermined temperature with a suitable cooling balance.

FIG. 8 is for explaining the gypsum mold 21, and FIGS. 8A and 8B show the gypsum mold 21 and the perforated holding cylinder (perforated stainless ring) 22 before assembly.
FIGS. 9A to 9C show a state where a gypsum mold and a perforated holding cylinder (perforated stainless ring) are assembled.
Thus, the gypsum mold 21 is housed and held in the perforated holding cylinder 22, and the gypsum mold 21 is very easy to handle by being housed and held in the perforated holding cylinder 22 in this way.

According to the casting apparatus of the present invention, it is possible to manufacture rings (rings), pendants, necklaces, brooches and other precious metal products having excellent quality and appearance.
Of course, it goes without saying that the casting apparatus of the present invention can be applied to the casting of metal products other than noble metal products.

DESCRIPTION OF SYMBOLS 11 Casting apparatus 12 Housing 12a Inner wall 12b Outer wall 13 Support base 13a Bottom surface 14 Injection nozzle 14a Air supply part 14b Pressure regulator 14c Injection time setting means 21 Gypsum type 21a Tight hole 22 Perforated holding cylinder (perforated stainless ring)

Claims (3)

A housing of the casting apparatus, a support base having air permeability, mounted with a gypsum mold installed at a predetermined interval from the wall surface of the housing in the housing, the gypsum mold gate, and a bottom surface of the support base And a plurality of injection nozzles for injecting compressed air toward the inner wall surface of the housing, the injection nozzles installed on the wall surface being installed in a tangential direction of the inner wall of the housing, and along the outer periphery of the gypsum mold A casting apparatus for precious metal products characterized in that a swirling flow is generated. The plurality of injection nozzles for injecting the compressed air injects the compressed air toward the bottom surface of the support base and the inner wall surface of the housing, thereby generating an upward flow swirling along the outer periphery of the gypsum mold. The casting apparatus for precious metal products according to claim 1, wherein The plurality of injection nozzles for injecting the compressed air can respectively set an injection start time and an end time for each of the injection nozzles in the air supply unit so that a predetermined amount of air can be injected from the air supply unit. The casting apparatus for precious metal products according to claim 1, wherein the casting apparatus is a precious metal product.

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