JPH1163852A - Vacuum melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum melting furnace which prevents the quality of molten metal from deteriorating by scraping out dross while holding vacuum and an inert gas atmosphere in a vacuum chamber, and which improves workability of scraping out dross by making a spatula of a dross scrape bar larger. SOLUTION: This vacuum melting furnace whose furnace body 2 is housed in a vacuum chamber 1 supported tiltably has a dross scraping device 20 mounted to a side wall 3 of the vacuum chamber 1. In this vacuum melting furnace, the dross scraping device 20 comprises a dross scrape bar 22 which divisionally connects pipes 8 to one another with pipe joints 23, a spherical part 24 through which an intermediate portion of the dross scrape bar 22 penetrates in such a manner as to freely stuck out and retracted, and which supports the dross scrape bar 22, a spherical support part 26 which slidably and rotatably supports the spherical part 24, and a guide roller 28 which guides an upper portion of the dross scrape bar 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum melting furnace in which an induction melting furnace is housed in a vacuum chamber and the furnace body is tilted together with the vacuum chamber when tapping the molten metal to discharge the molten metal. The present invention relates to improvement of a device for scraping out floating dross (slag).

[0002]

2. Description of the Related Art In general, melting of an active metal is performed in a vacuum atmosphere or an inert atmosphere such as an argon gas or a nitrogen gas in order to prevent a reaction with a refractory due to oxidation or absorption of hydrogen gas. An induction melting furnace such as a high-frequency melting furnace is used. These melting furnaces are generally housed in a fixed vacuum chamber, and when discharging molten metal, the furnace body is tilted in the vacuum chamber and the molten metal is poured into a ladle or a mold placed in the vacuum chamber. Was.

[0003] In such a melting method, however, the vacuum pipe is fixed and the evacuation is easy. On the other hand, the chamber needs to be extremely large in order to tilt the furnace inside the chamber. Is required.

[0004] For this reason, a tilting vacuum melting furnace in which a melting furnace accommodated in a vacuum chamber is tilted together with the vacuum chamber to discharge molten metal is also used. In this method, dross floating on the surface of the molten metal during melting causes defects when mixed in the product. Therefore, it is necessary to appropriately scrape the dross from the molten metal.

A conventional dross scraping device is a crucible-shaped furnace body 2 mounted in a vacuum chamber 1 as shown in FIG.
And a dross scraping device 4 is attached to the side wall 3 of the vacuum chamber 1 opposite to the gate of the furnace body 2. The dross scraping device 4 has a structure in which a cylindrical insertion port 5 is attached to the side wall 3, a gate valve 6 is provided in the middle thereof, and a lid 7 is attached to the opening of the insertion port 5.

When scraping dross floating on the surface of the molten metal during melting, a vacuum pump (not shown) is first stopped, the gate valve 6 is released, and the lid 7 of the insertion port 5 is removed. Next, a dross scraping rod 10 having a spatula 9 attached to the end of the pipe 8 is inserted into the furnace body 2 in the vacuum chamber 1 through the insertion port 5, and the dross scraping rod 10 is operated by the spatula 9 to operate the dross scraping rod. Into the dross basket 11. After the dross was scraped out, the dross scraping rod 10 was pulled out from the insertion port 5, the gate valve 6 was closed, the vacuum was again applied, and the furnace body 2 was tilted for tapping.

However, in the conventional apparatus, when the dross is scraped out, the dross is once released after the vacuum in the vacuum chamber 1 is released, so that the molten metal in the furnace body 2 comes into contact with the atmosphere and is oxidized during the dross removing operation. However, there is a problem that the quality is deteriorated. The dross scraping rod 10 is a cylindrical insertion port 5
Therefore, the size of the spatula 9 is limited, so that it is difficult to scrape out the dross over a wide range, and there is also a problem that if it is scraped out strongly, the dross scraping rod 10 enters the molten metal.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention eliminates dross while maintaining a vacuum or an inert gas atmosphere in a vacuum chamber, thereby preventing deterioration of molten metal quality. An object of the present invention is to provide a vacuum melting furnace in which the spatula of a dross scraping rod is enlarged to improve scraping workability.

[0009]

According to a first aspect of the present invention, there is provided a vacuum melting furnace in which a furnace body is housed in a tiltably supported vacuum chamber, and a dross scraping device is mounted on a side wall of the vacuum chamber. In the melting furnace, the dross scraping device includes a dross scraping rod, a spherical portion through which the intermediate portion penetrates in and out to support the scraping rod, and a spherical support portion which slidably and rotatably supports the spherical portion. It is characterized by becoming.

A vacuum melting furnace according to a second aspect of the present invention is characterized in that a guide roller for supporting an upper portion of a dross scraping bar is attached to a side wall of the vacuum chamber. Further, the vacuum melting furnace according to claim 3 is characterized in that the dross scraping bar has a divided structure.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
This will be described in detail with reference to FIG. A furnace body 2 such as a high-frequency induction melting furnace is housed inside the vacuum chamber 1 and fixed integrally therewith.
Are attached to the left and right to open and close freely. Hydraulic cylinders 14 are mounted on both sides of the vacuum chamber 1, and are tilted integrally with the furnace body 2 about a rotation shaft 15 mounted at the tip of the vacuum chamber 1. A drum type gutter device 17 is provided in the vicinity of the tap hole 16 of the melting furnace 2, and a gutter 18 is mounted in a horizontal direction inside the drum type gutter device 17. Has become.

A dross basket 11 is provided on the side of the furnace body 2 opposite to the tap hole 16, as shown in FIG.
0 and 20 are installed in two places. This dross scraping device 20 is, as shown in FIG.
A cylindrical insertion port 21 is provided in the
Is inserted. The dross scraping rod 22 is formed by connecting three pipes 8 by pipe joints 23, 23 so as to be freely splittable, and attaching a spatula 9 to a tip end.

An intermediate portion of the dross scraping rod 22 penetrates a central portion of the spherical portion 24 so as to be able to move in and out, and an O-ring therebetween.
Sealed with 25 to make it airtight. Further, the outer periphery of the spherical portion 24 is slidably and rotatably supported by a spherical support portion 26 attached so as to close the insertion opening 21, and an O-ring 25
Is also sealed. Reference numeral 27 denotes a grease cup attached to the spherical portion 24. A guide roller 28 for guiding the dross scraping bar 22 back and forth is provided above the spherical support 26, and a bracket 29 is laterally protruded below the spherical support 26. Is protruding.

When the dross floating on the surface of the molten metal is scraped out during melting in the vacuum melting furnace having the above configuration, the end of the dross scraping rod 22 is held in a hand while operating the vacuum pump.
The dross scraping rod 22 is moved back and forth to scrape the dross. In this case, the dross scraping rod 22 freely penetrates through the spherical portion 24 so that it can move in and out freely.
Since the is supported slidably and rotatably by the spherical support portion 26, the insertion angle can be freely selected, and the dross scraping rod 22 can be freely operated while maintaining the vacuum. In addition, since the upper part of the dross scraping bar 22 is guided by the guide rollers 28, it can be smoothly taken in and out, and the holding force is reduced, and the guide roller 28 regulates the descent angle of the tip of the dross scraping bar 22. The lower end of the spatula 9 does not enter the molten metal.

Further, since the dross scraping rod 22 is not configured to be taken out to the outside as it is conventionally attached to the vacuum chamber 1, the spatula 9 can be formed large and the dross scraping operation can be efficiently performed over a wide range. The dross scraping rod 22 connects the pipe 8 to the pipe joint.
Since it is a split type joined at 23, when the furnace body 2 is tilted, removing the pipe 8 on the rear end side does not hinder tilting.

In the above description, the case where the inside of the vacuum chamber 1 is evacuated and dissolved is shown, but the same applies to the case where an inert gas such as an argon gas or a nitrogen gas is sealed and dissolved. Further, in the above description, the case where the dross scraping bar 22 is of a split type is shown, but it may be formed by one pipe 8.

[0017]

As described above, according to the vacuum melting furnace of the present invention, the dross can be scraped out by freely inserting and removing the dross scraping rod at an arbitrary angle while maintaining the vacuum or inert atmosphere in the vacuum chamber. Therefore, the molten metal does not come into contact with the atmosphere, thereby preventing a decrease in quality. Further, since the dross scraping rod is held in the vacuum chamber, the size of the spatula can be increased, and the scraping operation can be efficiently performed over a wide range.

Further, the one provided with the guide roller can easily hold the dross scraping bar, and the one in which the dross scraping bar is divided can be removed at the time of tilting, so that various effects such as not hindering tilting can be obtained. Have

[Brief description of the drawings]

FIG. 1 is a side view of a vacuum melting furnace according to an embodiment of the present invention.

FIG. 2 is a plan view of the vacuum melting furnace shown in FIG.

FIG. 3 is a sectional view showing a dross scraping device attached to a vacuum melting furnace.

FIG. 4 is a sectional view showing a conventional dross scraping device attached to a vacuum melting furnace.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Furnace body 3 Side wall 4 Dross scraping device 8 Pipe 9 Spatula 11 Dross basket 16 Tap hole 21 Cylindrical insertion port 22 Dross scraping rod 23 Pipe joint 24 Spherical part 25 O-ring 26 Spherical support part 28 Guide roller

Claims (3)

[Claims] 1. A vacuum melting furnace in which a furnace body is housed in a tiltably supported vacuum chamber, and a dross scraping device is attached to a side wall of the vacuum chamber, wherein the dross scraping device includes a dross scraping rod and an intermediate member. A vacuum melting furnace, comprising: a spherical portion that penetrates a portion so as to be able to freely enter and exit and supports a scraping rod; and a spherical support portion that supports the spherical portion so as to be slidable and rotatable. 2. The vacuum melting furnace according to claim 1, wherein a guide roller for supporting an upper portion of the dross scraping bar is attached to a side wall of the vacuum chamber. 3. The vacuum melting furnace according to claim 1, wherein the dross scraping bar has a divided structure.