JP3021675B2 - Method and apparatus for manufacturing continuous cast rod having helical shape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a spiral groove,
The present invention relates to a method and an apparatus for producing a sound continuous cast rod having few defects on the inner and outer surfaces.

[0002]

2. Description of the Related Art As a method for obtaining a long rod having a spiral groove, for example, a thick rod is obtained by casting or the like, and a square rod or a rod having a linear groove is obtained from an extruder or the like. A method of adding a twist at both ends later, a method of continuously cutting a spiral on the surface of a rod by rolling or the like, and the like are known.

[0003]

Even THE INVENTION to be solved INVENTION These methods, to obtain a long rod with a continuous helical groove by continuously feeding the raw material rod during extrusion is a possible, in connection surface It is difficult to avoid contamination by extrusion lubricants and to avoid organizational changes.

Although it is possible to join the respective end faces by welding or the like after the extrusion, it takes time and effort to detect the presence or absence of a defect in the joint, and the deformation of the spiral groove in the joint is required. The rework was a complicated and difficult task.

[0005]

In view of such circumstances, the present inventors have conducted intensive studies on an efficient method of manufacturing a long rod having a spiral groove, and as a result, have found that a special mold is used for casting. The present inventors have found that a long rod having a spiral groove can be obtained by casting while rotating a body or a mold portion, thereby completing the present invention.

That is, the present invention relates to a casting method in which the cross section of a mold is polygonal.
Mold wall is spiral, or the mold cross-section with a continuous casting mold having a groove or projection carved spirally in the mold wall surface is circular, casting while rotating and pulling tailored to its helical slope Thereby, the continuous casting method characterized by continuously obtaining a casting rod having a spiral groove, and the inner wall surface or the whole of the continuous metal mold on the side of the molten metal supply section of the casting mold for continuous casting is at least the solidification temperature of the metal to be cast. to be heated by the heating element attached to the mold inside or outside, the method continuous casting which is characterized by using a mold made of unitary construction or a combination structure continuously cast bar extraction side is cooled below the solidification temperature, and its continuous casting Method
The present invention provides a continuous casting apparatus.

Hereinafter, the present invention will be described in detail. The present invention can be applied to all metals and their alloys, but the casting immediately after solidification needs to withstand the shearing force due to the rotation of the mold part or the rotation of the casting itself, and the pure metal or a small amount of alloy Systems containing elements are more suitable.

[0008] The rotation for obtaining the spiral casting rod is obtained by pulling out the casting while rotating it in accordance with the spiral gradient. If the casting rod becomes longer, the winding jig may be rotated together with the jig such as a spool or a bobbin.

[0009] Instead of rotating the casting rod, the casting rod is pulled out while rotating the mold part in accordance with the helical gradient, whereby a casting rod having a spiral groove can be continuously obtained.

As the rotating mechanism in the present invention, a mechanism for rotating the mold section, a mechanism for rotating the winding jig, a mechanism for integrally rotating the molten metal holding section for supplying the molten metal and the mold section, and the like are possible. .

When a long rod having a spiral groove has a small diameter, or when a spiral has a fine notch, a continuous casting mold can unidirectionally solidify in a direction opposite to a casting direction. It is preferable that the solidification interface shape is such that the solidification on the surface side of the cast rod tends to lag behind the solidification at the center.

[0012] For this purpose, it is effective that the casting mold is composed of a cooling portion below the solidification temperature of the metal to be cast and a heating portion above the solidification temperature. It is also effective to increase the temperature difference by strengthening the cooling by spraying water directly on the outlet side of the cooling section.

In order to ensure the unidirectional solidification, it is preferable that the temperature difference between the heating part and the cooling part is large. For this purpose, it is necessary to provide a heat insulating layer between the two parts.

The heating section can maintain the temperature of the molten metal at or above the solidification temperature by heat transfer from the molten metal holding section. However, even if a heat insulating layer is provided between the heating section and the cooling section, it is not always sufficient to achieve complete unidirectional solidification. Therefore, it is preferable to provide a heating element inside or outside the mold. As such a heating element, a heating element based on electric resistance, a heating element based on a dielectric coil, or the like can be used.

By continuously casting while rotating according to a helical gradient using a mold having such a heating section, a heat insulating section and a cooling section, a continuous casting rod having a spiral groove can be easily formed by a simple process. It became possible to manufacture.

Although the basic shape of the cross section of the mold in the present invention is a circle, any shape can be selected from triangles to polygons. For example, if the cross section is rectangular and the inner wall surface of the mold is helical, one having a helical appearance can be obtained. If the cross section is a circle, a continuous cast rod having a spiral groove can be obtained by using a mold having grooves or projections spirally formed on the inner wall surface of the mold.

Regarding the shape of the spiral groove of the continuous cast rod obtained in the present invention, any shape can be selected as long as it can be drawn.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0019]

FIG. 1 shows an example of a casting apparatus for carrying out the method of the present invention, showing a situation at the start of casting. The melting and holding furnace 1 has a heating element 2 and a molten metal holding crucible 3, and the molten aluminum 4 is melted and held. A combination of a graphite heating section 5 having a built-in mold heater 8, a copper mold cooling section 6 having a water-cooled interior, and a 1 mm thick asbestos cloth heat insulating section 7 which hinders heat transfer therebetween is provided on the side wall of the melting crucible. A mold is attached.

In this embodiment, the mold is mounted horizontally, but the same operation can be performed in the same manner even if the same mold is mounted directly downward on the bottom of the crucible. The inner diameter of the mold is 30mm
The inner wall is 5mm high, 10mm bottom, 60mm pitch
One triangular linear projection is engraved.

At the start of casting, it is necessary to plug the dummy block 9 so that the molten aluminum does not leak from the mold. The molten aluminum filling the mold solidifies in the cooling section and is strongly bonded to the dummy block. Coagulation Suruga progress to heat insulation section, coagulation more to the heating unit has been set the number ℃ higher than the solidification temperature of the aluminum by a temperature controller proceeds
Not line the shape of the solidification interface for cooling by heat transfer from the solidifying portion becomes slightly convex toward the traveling direction.

After confirming the solidification of the cooling section, 50 mm / min
Continuous casting was performed while rotating the dummy block and the continuous casting rod according to the spiral shape of the inner wall surface of the mold at a drawing speed of.

FIG. 2 shows a pair of rolls 11 for rotating and drawing.
And continuous casting rod 12 with spiral grooves on the outer wall
The appearance of is shown.

The appearance of the obtained continuous cast rod was a perfect reproduction of a smooth spiral, and there were no defects such as shrinkage cavities inside.

[0025]

As described above, according to the present invention, it is possible to continuously cast a long continuous rod having a helical appearance and having no defect inside, and its industrial value is extremely large.

[0026]

[Brief description of the drawings]

FIG. 1 is a side sectional view at the start of continuous casting by a combined heating and cooling mold apparatus.

FIG. 2 is a side sectional view of a casting apparatus during casting and an external view of a cast continuous casting rod.

[Explanation of symbols]

1. Melt holding furnace 7. Heat insulation part 2. Heater 8. 2. Mold heating heater Melt holding crucible 9. Dummy block 4. Molten aluminum 10. 4. Spiral protrusions on the inner wall of the mold Mold heating section 11. 5. Roller pair for rotary drawing Mold cooling unit 12. Continuous casting rod

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B22D 11/00 B22D 11/04

Claims (3)

(57) [Claims] 1. A continuous casting mold having a polygonal cross section of a mold and a spiral inner wall surface of the mold , or a circular cross section of the mold and having grooves or projections spirally cut on the inner wall surface of the mold, wherein the spiral gradient is reduced. A continuous casting method characterized by continuously obtaining a casting rod having a spiral groove by performing casting while performing combined rotation and drawing. 2. A continuous casting mold is heated by a heater attached to the inside or outside of the continuous casting mold at a temperature higher than the solidification temperature of the metal to be cast. The continuous casting method according to claim 1, wherein a mold having an integral structure or a combination structure cooled to a temperature or lower is used. 3. The continuous casting method according to claim 1 or 2.
A continuous casting apparatus characterized by using: