JP5395487B2 - Centrifugal casting method, centrifugal casting apparatus and casting pipe - Google Patents

Description

  The molten metal is poured into the cylindrical mold rotating around the rotation axis by a pouring device from one end of the cylindrical mold, and the molten metal is caused to follow the circumferential surface in the cylindrical mold by the centrifugal force of the cylindrical mold. A centrifugal casting method for solidifying while providing a cylindrical mold for centrifugal casting that forms a pouring space inside, and a supporting roller that supports the cylindrical mold so as to be driven and rotated around its axis. The present invention relates to a centrifugal casting apparatus and a casting pipe provided with a pouring device provided with a discharge port to be inserted into one end port of the cylindrical mold.

  Conventionally, the centrifugal casting technology has generally provided a pouring device consisting of a bowl that receives molten metal from a ladle at one end of a cylindrical mold, and the cylindrical mold is formed under the natural flow of molten metal from the pouring device. Hot water was poured into the mold (see, for example, Patent Document 1).

JP-A-6-87058

  In the above-described conventional centrifugal casting method and casting apparatus, as the cylindrical mold has a small diameter and a long length, it becomes more difficult to flow the molten metal from one end to the other end, and in the middle of the metal There is a problem that solidifies or a sufficient amount of molten metal does not reach the other end. In other words, if the cylindrical mold has a small diameter, the amount of pouring is small, the temperature of the hot water tends to decrease before reaching the tip of the hot water, and the diameter of the discharge port of the pouring device is also small. As a result, the hot water flow similarly deteriorated, and it was difficult to cast a long product with a small diameter.

  Accordingly, an object of the present invention is to provide a centrifugal force casting method and apparatus in which the above-mentioned problems are solved and a sufficient amount of molten metal is supplied to the other end even when the cylindrical mold has a small diameter and is long. is there.

In the centrifugal casting method of the present invention, the first characteristic configuration is that the molten metal is pressurized and discharged from a first end of the cylindrical mold rotating around the rotation axis by a pouring device, and the cylindrical mold is discharged. A centrifugal casting method in which the molten metal is solidified along the peripheral surface of the cylindrical mold by centrifugal force generated by inserting a discharge port of the pouring device from one end of the cylindrical mold. In the state where a gap is provided between the discharge port of the pouring device and the one end port of the cylindrical mold, the discharge port is disposed in the cylindrical mold, and the molten metal is supplied from the discharge port. Simultaneously with the discharge, the gas is caused to flow into the cylindrical mold through a gap around the discharge port and the molten metal is poured .

According to the first characteristic configuration of the present invention, the molten metal pressurized by the pouring device has a higher discharge flow rate from the discharge port and flows into the cylindrical mold vigorously.
Therefore, before the temperature of the poured molten metal decreases, the molten metal flows toward the hot metal side, and casting can be performed even if the cylindrical mold is small in diameter and long.
Further, the gas flowing in from the gap between the discharge port and the one end port increases the flow rate of the molten metal that is guided by the air flow and is discharged from the discharge port, so that it is easier to flow into the hot water side. Therefore, it is possible to cast a long tube even with a small diameter .

The second characteristic configuration of the present invention is that the gas is discharged from a gas discharge nozzle provided outside the one end of the cylindrical mold so as to cover the gap .

The third characteristic configuration of the present invention, prior SL with a difference in the flow velocity of the upper gas flow and the lower gas flow of the discharge port is to exert a lift on the discharge to the melt.

According to the third characteristic configuration of the present invention, the gas flows from the gap between the discharge port and the one end port, and acts by the difference in flow velocity between the gas flow above and below the discharge port. Due to the lift, the molten metal discharged from the discharge port floats upward and is supplied by being blown away from the one end port.
Therefore, it becomes easier for the molten metal to flow into the cylindrical mold faster to the other end and spread over the entire length.

The 4th characteristic structure of this invention exists in the place which set the gas flow path above the said discharge outlet longer than the gas flow path below the said discharge opening .

The characteristic structure in the centrifugal casting apparatus of this invention is a centrifugal casting apparatus used for the centrifugal force casting method of any one of the 1st-4th characteristic structure , Comprising: A pouring space is formed inside. a cylindrical mold for centrifugal casting, comprising a support roller for supporting freely rotated the tubular mold to its axis around the discharge port to be inserted into the tubular mold end opening of the pouring There exists an apparatus and the pressurization apparatus which pressurizes the molten metal accommodated in the said pouring apparatus, and discharges it from the said discharge outlet.

According to a second characteristic configuration of the centrifugal casting apparatus of the present invention, a suction device for sucking the gas in the pouring space from the other end of the cylindrical mold is provided on the other end. is there.

The characteristic configuration of the cast pipe of the present invention is a cast pipe cast by the centrifugal casting method according to any one of the first to fourth characteristic configurations, and has an inner diameter of 30 mm or less and a length of 500 mm or more. It is to be.

According to the onset bright, it can be manufactured having no small diameter seamless tubes.

It is a partial longitudinal cross-sectional view of the centrifugal casting apparatus of embodiment. It is a principal part longitudinal cross-sectional view. It is a principal part longitudinal cross-sectional view of another embodiment. It is a principal part longitudinal cross-sectional view of another embodiment. It is a principal part longitudinal cross-sectional view of another embodiment. It is a principal part longitudinal cross-sectional view of another embodiment.

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

  For example, when casting a small diameter pipe having an inner diameter of 30 mm or less and a length of 500 mm or more, as shown in FIGS. 1 and 2, a cylindrical metal for centrifugal casting that forms a pouring space 2 on the inner side. A pouring device provided with a mold 1, provided with a plurality of support rollers 3 for supporting the cylindrical mold 1 so as to be driven to rotate about its axis, and having a discharge port 4 inserted into one end 6 of the cylindrical mold 1. 5 is provided to constitute a centrifugal casting apparatus.

The pouring device 5 is provided with a hopper 8 that receives the molten metal and a discharge port 4 that discharges the molten metal into the pouring space 2, and pressurizing the molten metal accommodated in the pouring device 5 to discharge it from the discharge port 4. A device 9 is provided.
The pressurizing device 9 is provided with a hopper lid 10 for allowing the hopper portion 8 to be fitted in an airtight state in a detachable manner, and an inert gas supply portion 11 for injecting an inert gas into the hopper portion 8. A press-fitting part 12 for gas from the active gas supply part 11 is provided in the hopper lid 10.

A suction device 13 for sucking the gas in the pouring space 2 from the other end port 7 of the cylindrical mold 1 is provided in the other end port 7 so as to be freely mounted.
The suction device 13 includes a vacuum pump 14, a vacuum chamber 15, an opening / closing valve 16, a filter 17, and a suction port 18, which are connected in communication, and the vacuum pump 14 is operated to open the opening / closing valve 16. By sucking the gas in the pouring space 2 from the suction port 18 through the filter 17, the sucked gas enters the vacuum chamber 15 through the filter 17 and the opening / closing valve 16, and is discharged outward from the vacuum pump 14. Is exhausted.
As a result, the inside of the pouring space 2 of the cylindrical mold 1 is in a depressurized state, and gas flows from a gap between the discharge port 4 and the one end port 6 of the cylindrical mold 1.

About the method of casting with the said centrifugal force casting apparatus, it carries out in the following order.
1. The support roller 3 is driven and rotated to rotate the cylindrical mold 1 at high speed, the suction port portion 18 of the suction device 13 is attached to the other end port 7 of the cylindrical mold 1, and the discharge port 4 of the pouring device 5 is connected to the cylinder. 1. Insert into one end 6 of the mold 1. The vacuum pump 14 of the suction device 13 is operated, and the molten metal is poured into the hopper portion 8 of the pouring device 5.
3. The hopper lid 10 is fitted to the hopper 8 and an inert gas is press-fitted into the hopper 8 from the gas supply unit to discharge the molten metal from the discharge port 4 and open the opening / closing valve 16. 4). When a predetermined amount of molten metal is cast into the pouring space 2, the cylindrical mold 1 is continuously driven and rotated until the molten metal in the cylindrical mold 1 is solidified.
5. After the metal in the pouring space 2 is solidified, the rotation of the cylindrical mold 1 is stopped and the molded metal is taken out from the cylindrical mold 1.

[Another embodiment]
Other embodiments will be described below.

<1> In the centrifugal casting apparatus, the example in which both the pressurizing device 9 of the pouring device 5 and the suction device 13 are provided is shown, but at least one of them may be provided.
<2> If the discharge port 4 of the pouring device 5 is connected to the one end port 6 of the cylindrical mold 1 in an airtight manner so that there is no gap, the inside of the pouring space 2 is a suction device. 13 is further reduced in pressure, and the pressure difference between the discharge port 4 and the internal space of the hopper 8 is increased, the discharge flow rate of the molten metal from the discharge port 4 is increased, and it is advantageous that the cylindrical mold 1 is elongated. It is.
<3> To discharge the internal gas outward from the other end 7 of the cylindrical mold 1 and allow the external gas to flow into the internal space from the one end 6, as shown in FIG. Instead of providing, the exhaust vane 19 that discharges the gas in the pouring space 2 to the outside from the other end 7 of the cylindrical mold 1 as the cylindrical mold 1 rotates is attached to the other end 7. There may be.
<4> Further, in order to increase the flow rate of the discharged molten metal by flowing gas between the discharge port 4 of the pouring device 5 and the one end port 6 of the cylindrical mold 1, as shown in FIG. A gas discharge nozzle 20 that actively flows out a gas such as an inert gas may be mounted around the discharge port 4.
<5> In order to apply a lift to the molten metal discharged from the discharge port 4 of the pouring device 5 and pour the molten metal from the one end port 6 toward the hot water side, the air is blown from the gap between the discharge port 4 and the one end port 6. The gas may have a difference in flow rate between the gas flow on the upper side of the discharge port 4 and the gas flow on the lower side. In this case, for example, as shown in FIG. 5, the external shape of the discharge port 4 may be devised.
<6> As shown in FIG. 6, the discharge port 4 of the pouring device 5 is formed obliquely upward so that the molten metal can fly to the other end 7 side farther from the one end 6 of the cylindrical mold 1. It may be.
<7> The example in which the discharge port 4 of the pouring device 5 is inserted into the cylindrical mold 1 from the one end port 6 at the time of pouring is shown, but in some cases, the discharge port 4 may be inserted into the one end port 6. Instead, the hot water may be poured from the outside.

  As described above, reference numerals are used for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

  The centrifugal casting technique of the present invention can be used not only for casting small diameter metal tubes but also for casting large diameter metal tubes.

DESCRIPTION OF SYMBOLS 1 Cylindrical metal mold | die 2 Pouring space 3 Support roller 4 Discharge port 5 Pouring device 6 One end port 7 Other end port 9 Pressurizing device 13 Suction device 19 Exhaust blade

Claims (7)

The molten metal is pressurized and discharged from one end of the cylindrical mold rotating around the rotation axis by a pouring device, and the molten metal is surrounded by the centrifugal force by the cylindrical mold. It is a centrifugal casting method that solidifies along the surface,
The discharge port of the pouring device is inserted from one end port of the cylindrical mold, and the discharge port is provided with a gap provided between the discharge port of the pouring device and the one end port of the cylindrical mold. A centrifugal casting method in which an outlet is disposed in the cylindrical mold, and at the same time as the molten metal is discharged from the discharge port, gas is caused to flow into the cylindrical mold through a gap around the discharge port and the molten metal is poured. . The centrifugal casting method according to claim 1, wherein the gas is discharged from a gas discharge nozzle provided outside one end of the cylindrical mold so as to cover the gap . With a difference in flow rate before Symbol discharge opening above the gas flow and the lower side of the gas flow, centrifugal casting method according to claim 1 or 2 exerts a lift on the discharge to the melt. The centrifugal force casting method according to claim 3, wherein a gas flow path above the discharge port is set longer than a gas flow path below the discharge port . A centrifugal casting apparatus used in the centrifugal casting method according to any one of claims 1 to 4 ,
A cylindrical mold for centrifugal casting for forming a pouring space inside,
A supporting roller which drives rotatably supporting the cylindrical mold to the axis around
A pouring device provided with a discharge port for insertion into the tubular mold end opening of
Centrifugal casting apparatus and a pressurizing apparatus for discharging from the discharge port by pressurizing the molten metal accommodated in the pouring device. Centrifugal casting device according to the other end opening of the front Symbol cylindrical mold a suction device for sucking gas in the pouring space to claim 5 is provided to be freely mounted on the other end opening. 5. A cast pipe cast by the centrifugal casting method according to claim 1, wherein the cast pipe has an inner diameter of 30 mm or less and a length of 500 mm or more .

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