JPH0444297Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a vertical continuous casting device for hollow metal ingots, and has particularly improved measures against leakage of molten metal.
Concerning equipment that ensures operational safety.

(Prior Art) Metal hollow ingots are used directly for pipe products and are important as materials for plastic working of annular body products such as vehicle rims, and are mainly manufactured by vertical continuous casting.

As a specific example of the method, (a)
This is disclosed in Figures 3 and 4 of Japanese Patent Publication No. 102916, or Figures 6 and 7 of Japanese Patent Publication No. 56-46466. That is, a core is held inside a cylindrical mold, and a pedestal that is movably supported rises from below a gap formed between the two, and an annular body fixed to the top of the pedestal rises from below the gap formed between the two. Fitting and sealing the lower part of the gap, molten metal is continuously injected into the gap from above, a solidified shell is formed by primary cooling in the mold, and then the pedestal is continuously lowered. Further, cooling water is directly radiated to the outer peripheral solidified shell below the outside of the mold for secondary cooling and solidification to the inside. When a predetermined long ingot is reached, the injection of molten metal is stopped, the cylindrical mold and core are removed, the pedestal is raised, and the long hollow ingot is taken out.

In the above cases, the cylindrical mold is forcedly cooled with almost no exceptions, but the core is forcedly cooled as in cases (a) and (b), and as shown in Japanese Patent Publication No. 55-42655, the core is forcedly cooled. Types made of refractory materials that do not easily get wet (non-forced cooling type) are also used.

(Problems to be solved by the invention) Among the troubles that occur in the continuous casting of hollow ingots as described above, the most difficult problem is leakage of molten metal during casting, which is the primary cooling in the gap between the cylindrical mold and the core. The thin solidified film that is initially formed on the surface of the molten metal body is in an unstable state, and the volumetric contraction accompanying solidification and the effect of baking on the surface of the mold or core compete, and the balance between these effects becomes unstable. When it collapses, the coagulated film ruptures, and the molten metal leaks out and flows down.

Once this phenomenon occurs, a large amount of heat flow from the molten metal concentrates locally and exceeds the cooling capacity of the mold or core, so that the torn membrane can no longer be healed and the entire amount of molten metal in the mold flows down. If such a situation occurs, the operator immediately stops pouring the molten metal.

The above-mentioned molten metal leakage phenomenon is governed by delicate interface conditions on the walls of the mold or core, and these are also under the influence of multiple factors, so this phenomenon cannot be controlled and the probability of occurrence is low to some extent. The current situation is that it is unavoidable.

By the way, in the case of a solid ingot, the molten metal that flows down due to the above-mentioned molten metal leakage solidifies and adheres to the periphery of the pedestal on the lifting base, and it is relatively easy to peel and remove it. However, in the case of hollow ingots it is quite difficult. That is, the molten metal leaking from the outer periphery of the core accumulates and solidifies inside the pedestal, which is extremely difficult to remove, and in many cases it is necessary to remove the pedestal from the lifting base. Furthermore, the secondary cooling water emitted from the bottom end of the core accumulates inside the pedestal, so if the pedestal is not equipped with a drainage means (device in (a) above) or if a drainage port is not provided at the bottom of the pedestal. (The device in (b) above) is dangerous because an explosive reaction occurs between the molten metal and water.

The present invention was developed in view of the above-mentioned circumstances, and when molten metal leaks from the outer periphery of the core during continuous casting of hollow ingots, it facilitates the removal of the solidified material of the leaked molten metal and removes the molten metal. The aim is to develop a device that can prevent explosions due to contact with water.

(Means for Solving the Problems) To explain the apparatus of the present invention based on the drawings, FIG. 1 shows a hot-top type continuous casting apparatus having a forced cooling core 2. A water-cooled core 2 is held with a gap 3 in between, and a hot top 10 made of a refractory heat insulating material is placed and connected on top of the mold and the core. An annular body 4 at the top of a pedestal 5 fixed on a base 12 directly below the cylindrical mold and connected to a lifting mechanism (not shown)
rises and fits below the gap 3 to seal it,
Then, molten metal is injected from the gutter 11 to fill the gap 3. A solidified shell is formed around the hollow molten metal,
The pedestal 5 descends, the secondary cooling water 13 is directly radiated onto the surface of the solidified shell, and the solidified ingot 14 is supported by the pedestal and continuously descends.

There is a ridge line 9 in the pedestal 5 inside the annular body 4.
Two slopes 7a and 7b are provided, and the lower ends of the slopes are connected to the opening 8 on the side surface of the pedestal 5.
a and 8b, respectively.

FIG. 2 shows another embodiment of the apparatus of the present invention, which is a float-type continuous casting apparatus that maintains the molten metal level within the cylindrical mold 1, and the figure shows the situation at the start of casting. The core 2 is held inside the cylindrical mold 1 with a gap 3 interposed therebetween, and the annular body 4 at the top of the pedestal 5 fits and seals the lower part of the gap 3. in this case,
A slope 7 is formed inside the annular body 4 to pass through the pedestal 5, and the lower end of the slope 7 is connected to an opening 8 on the side surface of the pedestal 5.

In the device of the present invention, the angle of the slope 7 is
The degree to which the flowing molten metal smoothly slides down the slope and is discharged onto the base 12 is selected, and this is adjusted depending on the size of the ingot, the type of alloy, the physical properties of the molten metal, etc., but in general, the degree is 30% relative to the base. degree or more preferably 45
An elevation angle greater than or equal to degrees is chosen. Further, it is desirable that the opening 8 be opened as wide as possible without impairing the strength of the pedestal 5. This is unsuitable because molten metal and water tend to accumulate in an opening that is narrower than the width of the slope. Since steps and irregularities on the slope surface prevent the molten metal and water from sliding down, the connection between the lower end of the slope and the opening on the pedestal side must be configured to be smooth with this point in mind.

It goes without saying that the present invention is suitable as a continuous casting apparatus for not only cylindrical ingots but also hollow ingots of various cross-sections.

(Function) As described above, the device of the present invention penetrates the pedestal inside the annular body that is located at the top of the pedestal and fits into the gap between the cylindrical mold and the core, and makes at least one downward direction. A slope is formed, and the lower end of the slope is connected to the opening on the side of the pedestal, so that molten metal leaking from the outer periphery of the core or cooling water radiated from the lower end of the core accumulates inside the pedestal. It is immediately released onto the base outside the pedestal without any damage.

Although water is leaking onto the base, since there is no standing water, there is no condition for an explosive reaction to occur due to contact with the molten metal, and the solidified material of the molten metal discharged onto the base has good peelability.

(Effects of the invention) As mentioned above, if continuous casting of hollow ingots is performed using the apparatus of the invention, even if there is a leakage of molten metal from the outer periphery of the core or a flow of secondary cooling water radiated from the lower end of the core, Since the molten metal or water is immediately released onto the base without accumulating inside the pedestal, there is no explosion, and it is also easy to peel off and remove the solidified molten metal, ensuring operational safety. This feature also improves work efficiency.

[Brief explanation of the drawing]

Figure 1 shows an example of the device of the present invention, in which two slopes with ridgelines are provided in the pedestal, where a is a longitudinal cross-sectional view of the entire device, and b is a side view of the pedestal portion ( A-A' arrow view in Figure a) and c are cross-sectional views of the pedestal portion (B-B' arrow view in Figure A). Figure 2 shows
Another example of the device of the present invention is a case where one slope is provided in the pedestal, where a is a longitudinal cross-sectional view of the entire device (viewed from arrow B-B' in Figure b), and b is the pedestal portion. It is a cross-sectional view (A-A' arrow view of figure a). 1... Cylindrical mold, 2... Core, 3... Gap, 4
... Annular body, 5 ... pedestal, 7, 7a, 7b ... slope in the pedestal, 8, 8a, 8b ... opening on the side of the pedestal, 9 ... ridge line, 11 ... molten metal injection gutter, 12 …
... Lifting base, 13... Secondary cooling water, 14... Hollow ingot, 15... Molten metal.

Claims (1)

[Claims for Utility Model Registration] 1. A cylindrical mold 1, a core 2 held on the inside thereof with a gap 3 in between, and a pedestal located below the cylindrical mold 1 and supported so as to be movable up and down. 5, and an annular body 4 that fits below and seals the gap 3 at the top of the pedestal 5. A series of hollow ingots characterized in that at least one slope 7 in the direction is formed passing through the pedestal 5, and the lower end of the slope 7 is connected to an opening 8 on the side surface of the pedestal 5. Casting equipment. 2. The hollow casting according to claim 1, wherein the slope 7 is comprised of two slopes 7a and 7b having a ridgeline 9 in the pedestal 5 inside the annular body 4. Continuous ingot casting equipment.