JPH08229668A - Casting chute - Google Patents

Abstract

PURPOSE: To eliminate adverse effect on quality by dispensing with an operation for applying coat on the surface of a chute which comes into contact with a molten metal, eliminating sticking of the molten metal on the chute and also preventing the molten metal from being mixed with the coat. CONSTITUTION: The device is a casting chute 11 which guides to a horizontal trough 13 a molten metal flowing down from a foundry ladle, which has a chute surface structured with a porous formed product 12 using a heat resistant material durable against the temperature of a molten metal, and which has a means for blowing gaseous nitrogen into the porous formed product 12. The porous formed product 12 is cooled with its chute surface simultaneously formed with a nitrogen gas film, so that the molten metal supplied from the foundry ladle does not come into contact directly with the chute surface, preventing the molten metal from sticking to the chute surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting chute used when centrifugally casting a cast iron pipe, for example.

[0002]

2. Description of the Related Art When centrifugally casting a cast iron pipe, as shown in FIG. 2, a horizontal metal frame 1 which rotates around a horizontal axis is provided on a casting carriage 2 and the metal frame 1 is horizontal. The trough 3 of the direction can be inserted. A chute 4 is integrally provided at the base end of the trough 3, and the molten metal 6 from the triangular ladle 5 can be supplied to the chute 4 by tilting the triangular ladle 5. That is, the molten metal 6 flowing down due to the tilt of the triangular ladle 5 is guided by the chute 4,
The potential energy is converted into kinetic energy in the horizontal direction, flows to the tip side of the trough 3, and is poured into the metal frame 1 from there. Therefore, by moving the casting carriage 2 in the axial direction of the metal frame 1 while rotating the metal frame 1, the molten metal 6 is supplied over the entire circumference and the entire length of the metal frame 1 by the action of centrifugal force. , A predetermined pipe will be centrifugally cast.

[0003]

The trough 3 and the chute 4 are made of cast steel, and in particular, when the hot melt 6 supplied from the triangular ladle 5 directly hits the chute 4, the melt 6 may be seized on the chute 4. In order to prevent this, conventionally, a coating mold is manually applied to the molten metal contact surface of the chute 4 before performing centrifugal casting.

However, if the coating state of the coating type on the chute 4 is poor, the molten metal 6 may be seized on the chute 4, requiring subsequent maintenance. Further, the coating mold applied to the molten metal contact surface of the chute 4 may adhere to the side of the molten metal supplied from the triangular ladle 5 and may be peeled off from the molten metal contact surface of the chute 4, and the peeled coating mold is the molten metal. There is a problem that the quality is adversely affected by being mixed with.

The present invention solves such a problem and does not require the work of applying the above-mentioned conventional coating mold to the molten metal contact surface of the chute, and prevents the molten metal from sticking to the chute and coating the molten metal. The purpose is to eliminate the mixture of molds and to prevent the quality from being adversely affected.

[0006]

In order to solve this problem, the present invention is a casting chute for guiding the molten metal flowing down from a ladle to a trough in a horizontal direction, which is heat resistant to withstand the temperature of the molten metal. A chute surface is formed by a porous molded product formed of a material, means for blowing nitrogen gas into the porous molded product is provided, and a nitrogen gas film is formed on the chute surface of the porous molded product. Is the gist.

[0007]

With this configuration, by blowing nitrogen gas into the porous molded article, the porous molded article is cooled and a nitrogen gas film is formed on the surface (shoot surface) of the porous molded article.
As a result, the melt supplied to the chute does not directly touch the chute surface, and the melt does not burn onto the chute surface. By covering the chute surface with a nitrogen gas film in this way, there is no need to apply a conventional coating mold to the molten metal contact surface of the chute, no labor is required, and the coating mold is mixed into the molten metal. Moreover, it does not adversely affect the quality of the centrifugally cast product.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a triangular ladle (not shown)
The chute 11 that receives the high-temperature molten metal supplied from is made of a material that can sufficiently withstand the temperature of the molten metal (for example, silicon carbide containing C or SiC as the main component), and the surface serving as the chute surface is formed into a circular arc shape. A quality molded product (12) is formed by setting it in a frame body (14) integrally provided at the upper end portion of a horizontal cast steel trough (13). A large number of holes 15 are formed in the bottom of the frame body 14, and the nitrogen gas supplied from the nitrogen gas supply hole 17 provided in the cover 16 made of a heat-resistant material that covers the bottom of the frame body 14 forms the holes 15. Is blown into the porous molded article 12 through
A nitrogen gas film is formed on the surface (chute surface) of the porous molded product 12 by discharging from the surface of the porous molded product 12.

In the above structure, the molten metal that flows down by tilting the triangular ladle is a porous molded product 12 that forms a chute surface.
By being guided to the surface of, the potential energy is converted into horizontal kinetic energy and flows to the tip side of the trough 13, and from there is poured into the metal frame as in the conventional example. Therefore, by moving the casting carriage in the axial direction of the metal frame while rotating the metal frame, the molten metal is supplied over the entire circumference and the entire length of the metal frame by the action of centrifugal force, and the predetermined pipe is formed. The centrifugal casting is the same as in the conventional example. By the way, in the present embodiment, since nitrogen gas is blown into the porous molded article 12,
Since the porous molded article 12 is cooled by the nitrogen gas and a nitrogen gas film is formed on the surface (chute surface) of the porous molded article 12, the molten metal supplied from the triangular ladle does not directly touch the chute surface, and The molten metal does not burn onto the chute surface.

If nitrogen gas is not supplied to the porous molded product 12 made of silicon carbide containing C and SiC as the main components, the porous molded product 12 will be consumed by oxidation. Is blown to form a nitrogen gas film on the surface of the porous molded article 12, whereby the porous molded article 12 can be prevented from being consumed by oxidation and the durability can be improved.

[0011]

As described above, according to the present invention, the nitrogen gas is blown into the porous molded article to cool the porous molded article and form a nitrogen gas film on the surface (shoot surface) of the porous molded article. However, as a result, the melt supplied to the chute does not directly touch the chute surface, and the melt does not seize on the chute surface. By covering the chute surface with a nitrogen gas film in this way, there is no need to apply a conventional coating mold to the molten metal contact surface of the chute, no labor is required, and the coating mold is mixed into the molten metal. Moreover, it does not adversely affect the quality of the centrifugally cast product.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a main part of a casting chute according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional centrifugal casting equipment for pipes using a casting chute.

[Explanation of symbols]

 11 Chute 12 Porous molded product 13 Trough 14 Frame 15 hole 16 Cover 17 Nitrogen gas supply hole

Claims (1)

[Claims] 1. A casting chute for guiding molten metal flowing down from a ladle to a trough in a horizontal direction, the chute surface being formed by a porous molded product formed of a heat-resistant material capable of withstanding the temperature of the molten metal. A casting chute characterized in that a means for blowing nitrogen gas into the porous molded product is provided, and a nitrogen gas film is formed on the chute surface of the porous molded product.