JPH0740023A - Centrifugal casting method - Google Patents

Abstract

PURPOSE:To restrain the occurrence of casting defect such as the entrapment of impurity and air, by alternately and repeatedly executing the casting work of molten metal into a mold from both sides of the opening parts at both ends so as not to cast the molten metal against the stream at the tip surface part of the cast molten metal. CONSTITUTION:Annular members 5, 6 functioning as wires of the cast molten metal through troughs 4A, 4B for centrifugal force casting are fitted to the opening parts at both ends of the mold 1. The molten metal pouring work is alternately and repeatedly executed from both sides of the opening parts at both ends so as not to cast the molten metal against the stream at the tip surface part of the cast molten metal. Then, the molten metal cast into the mold 1 from the one side of the opening part side and the molten metal cast from the other side of the opening part side are avoided to collide against the stream at the tip surface part of the already cast molten metal. Therefore, the occurrence of the disturbed molten metal stream caused by the collision of the molten metal and the scattering of the molten metal as drips are restrained. By this method, the occurrence of the casting defect is restrained and the formation of unsound casting layer in the inner peripheral part of the centrifugal force casting tube is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal casting method, and more specifically, while rotating a horizontal centrifugal casting mold in which an annular member having a damming function for molten metal is attached to both openings. The present invention relates to a centrifugal casting method in which a molten metal is cast into at least one of the openings at both ends to cast a tubular body by centrifugal force.

[0002]

2. Description of the Related Art In such a centrifugal casting method,
Conventionally, the casting work of the molten metal into the mold has been continuously performed without interruption from only one of the both end openings to perform centrifugal casting of the tubular body.

[0003]

In such a conventional centrifugal casting method, a very disturbed flow of the molten metal occurs at the molten metal pouring position after a certain time has passed since the molten metal was cast. And the phenomenon that the molten metal becomes droplets and scatters, and these phenomena cause a problem that a casting unhealthy layer is formed on the inner peripheral portion of the centrifugal casting pipe. there were. That is, as shown in FIG. 2, annular members 5 and 6 (so-called bands 5 and 6) having a damming function of the molten metal are introduced into a mold 1 for horizontal centrifugal casting, which is attached to openings at both ends. When the molten metal is continuously cast only from the opening of the mold, the cast molten metal rotates from the casting position to the tip side in the axial direction of the mold 1 (Fig. )), The molten metal has an annular member 6 on the tip side.
When the molten metal layer reaches a sufficient thickness, the surface portion of the molten metal is reflected by the annular member 6 and faces the flow of the molten metal that is subsequently cast from the one opening. It will come back to the casting side. Then, when the front surface portion of the molten metal returns to the casting position (see FIG. 2B), the molten metal A that has returned to that position becomes the molten metal B that is subsequently cast from the one opening. The collision causes a very disturbed flow of the molten metal, or the molten metal is scattered as droplets. Then, due to the turbulent flow and the molten metal scattering, casting defects such as inclusion of impurities such as slag and a coating agent and air, etc. at the casting position will occur, and the centrifugal casting pipe There was a problem that a casting unhealthy layer would be formed on the inner peripheral part of the. The present invention has been made in view of such an actual situation, and an object thereof is to provide means capable of solving the above-mentioned problems.

[0004]

The centrifugal casting method according to the present invention (hereinafter referred to as the present invention method) is intended for horizontal centrifugal casting in which an annular member having a molten metal damming function is attached to both end openings. While rotating the mold, casting a molten metal into the mold from at least one of the both end openings, a centrifugal casting method for centrifugally casting a cylindrical body, the operation of casting the molten metal into the mold Is alternately repeated so as not to oppose the flow of the front surface portion of the molten metal cast into the mold from both of the both end openings.

[0005]

According to the method of the present invention, the molten metal pouring work is alternately repeated from both of the opening portions at both ends so as not to oppose the flow of the front end surface portion of the molten metal to be cast. The molten metal cast into the mold, the molten metal cast into the mold from the other opening side, any of the molten metal, the tip surface portion of the molten metal already cast into the mold at the time of casting The collision with the flow of will be avoided. Therefore, it is possible to prevent a very disturbed flow of the molten metal or the molten metal from being scattered as droplets due to the collision of the molten metal.

[0006]

As described above, according to the method of the present invention, the occurrence of turbulence of the molten metal, scattering of the molten metal, etc. is suppressed, so that impurities, air, etc. caused by the disorder of the molten metal, scattering of the molten metal, etc. Therefore, the conventional problem that the casting unhealthy layer is formed in the inner peripheral portion of the centrifugal casting pipe is eliminated by suppressing the occurrence of casting defects such as the above, and thus the object of the present invention is achieved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a horizontal centrifugal casting mold (specifically, a cylindrical metal frame), and the mold 1 is
The engaging recesses 1a and 1b are carried while being locked by the supporting rollers 2 and 3 which are rotationally driven by a driving device (not shown),
It is adapted to rotate following the rotation of the support rollers 2 and 3.

A first centrifugal force for receiving the molten metal from a ladle (not shown) and casting the molten metal into the mold 1 is provided at the one end opening (the left side opening in FIG. 1) of the mold 1. A casting trough 4A is provided with its tip facing the inside of the mold 1. The first centrifugal casting trough 4A is equipped with a stopper 4a that can be opened and closed.

On the other hand, a second opening for receiving the molten metal from a ladle (not shown) and casting the molten metal into the mold 1 is provided in the other end opening (the right side opening in FIG. 1) of the mold 1. A centrifugal casting trough 4B is provided with its tip facing the inside of the mold 1. The second centrifugal casting trough 4B is equipped with a stopper 4b that can be freely opened and closed.

Further, annular members 5 and 6 (so-called band 5, which functions as a dam for the molten metal to be cast through the centrifugal casting troughs 4A and 4B, are provided in the openings of both ends of the mold 1. 6) is installed.

When carrying out the method of the present invention in such a casting apparatus, first, as shown in FIG. 1 (a), the molten metal is cast through the first centrifugal casting trough 4A in which the stopper 4a is opened. . At the time of this casting, the stopper 4b of the second centrifugal casting trough 4B is closed. After the casting is performed, the tip surface part a of the molten metal that advances in the axial direction of the mold 1 while rotating, hits the band 6 attached to the opening on the side opposite to the casting position of the molten metal and changes the traveling direction. At the time of reversing and starting to return to the casting position, as shown in FIG. 1B, the stopper 4a of the first centrifugal casting trough 4A.
Closed to interrupt the molten metal pouring operation via the first centrifugal casting trough 4A, and open the stopper 4b of the second centrifugal casting trough 4B to stop the molten metal pouring operation via the second centrifugal casting trough 4B. , The tip surface portion a of the molten metal already cast into the mold 1
Start not to go against the flow of. After the casting operation via the second centrifugal casting trough 4B is started, the tip surface portion a hits the band 5 attached to the opening portion on the casting position side, the traveling direction is reversed, and the opening on the opposite side is formed. As shown in Fig. 1 (c), the second
Closing the stopper 4b of the centrifugal casting trough 4B to interrupt the molten metal casting operation via the second centrifugal casting trough 4B, and
Open the stopper 4a of the first centrifugal casting trough 4A
The molten metal casting operation via the centrifugal casting trough 4A is restarted so as not to oppose the flow of the tip surface portion a of the molten metal already cast into the mold 1. Further, these series of operations are repeated as many times as necessary.

According to the method of the present invention as described above, the molten metal pouring work is alternately repeated from both of the openings at both ends so as not to oppose the flow of the front end surface portion a of the molten metal to be poured, so that one opening Both the molten metal cast into the mold 1 from the side of the mold, the molten metal cast into the mold 1 from the side of the other opening, and any of the molten metals at the time of casting
It becomes possible to avoid collision with the flow of the front end surface portion a of the molten metal which has already been cast into the inside. Therefore, due to the collision of the molten metal, a very disturbed flow of the molten metal occurs, or the molten metal scatters as droplets.
That will be suppressed.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an implementation state of a method of the present invention.

FIG. 2 is an explanatory diagram showing an implementation state of a conventional method.

[Explanation of symbols]

 1 Mold 5, 6 Annular member

Claims (1)

[Claims] 1. At least one of the openings at both ends of the mold is rotated while rotating a mold (1) for horizontal centrifugal casting in which annular members (5), (6) having a function of blocking molten metal are attached to the openings at both ends. A centrifugal force casting method in which a molten metal is cast into the mold (1) from one side to centrifugally cast a tubular body, and the operation of casting the molten metal into the mold (1) is performed at the both end openings. The centrifugal casting method in which the molten metal cast into the mold (1) is alternately and repeatedly performed so as not to oppose the flow of the front surface portion of the molten metal.