JPS6039456B2 - Forced cooling mold for semi-continuous casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to forced cooling molds for semi-continuous casting of metals, and in particular to forced cooling molds for hot-top casting of aluminum and its alloys.

The present invention is based on the patent application No. 51-896 filed by the present applicant.
2bi No. 53-15222 (Japanese Unexamined Patent Publication No. 53-15222), "Metal semi-continuous casting method and apparatus", Hakama Akira Sho 52-29328 (Japanese Patent Publication No. 53-11473), "Metal semi-continuous casting apparatus", and Special Sardine No. 53-36041 (Japanese Unexamined Patent Publication No. 54-1283
No. 434) relates to an improvement of a forced cooling mold in a "continuous metal casting apparatus".

In the continuous casting of metals, it is important to provide a lubricant (so-called template agent) at the contact interface between the forced cooling mold and the molten metal, and in the continuous casting of aluminum and its alloys (hereinafter simply referred to as aluminum), A liquid lubricant, for example an oil such as castor oil, must be used to supply the liquid lubricant evenly and continuously over the entire inner circumference of the forced cooling mold.

Therefore, the shape of the liquid lubricant discharge port and the supply flow path are also mentioned in the above-mentioned prior application. First, in the forced cooling mold for a metal semi-continuous casting machine proposed by Tokusei in 1989-8962, a large number of holes are provided at constant intervals around the entire circumference on the inner surface of the mold to serve as discharge ports for liquid lubricant. There is.

In this case, the hole diameter of these liquid lubricant supply holes is 0.5 ribs (diameter) and the number of holes is 100 (specification, page 17, 19
(line 1), and drilling these holes takes a very long time. Therefore, the reason why the hole diameter was set to 0.5 was that while increasing the hole diameter makes processing easier, it also increases the possibility of molten metal being inserted. This phenomenon occurs and becomes thicker, but processing becomes difficult (
This is because the drill is easy to break).
Note that the phenomenon of molten metal penetration is that the molten metal enters the hole, and as a result, it sticks to the surface of the ingot being cast, causing surface defects such as eaves. Such hole-type forced cooling molds have the advantage that the amount of lubricant discharged is almost the same in all molds, and there is little variation, but once molten metal has been inserted, it is difficult to repair the holes. Therefore, Japanese Patent Application No. 52-29328 proposed a forced cooling mold in which a liquid lubricant supply hole was provided on the upper surface of the forced cooling mold rather than on the inner surface to prevent the phenomenon of molten metal pouring.

In this case, the lubricant flows out to the inner surface of the mold through a slit between the upper surface of the forced cooling mold and a metal melt receiving tank made of an insulating refractory provided above the forced cooling mold.
Even if the molten metal is able to circulate, the lubricating oil is significantly absorbed by the heat insulating refractories (headers) that make up the molten metal receiving tank, shortening the life of the metal receiving tank. Furthermore, in Japanese Patent Application No. 53-36041 filed by the present applicant, a forced cooling mold is divided into two parts (a mold body and an annular member), and a gap is formed in a part of their mating surfaces, that is, a liquid lubricant is provided. A supply channel for the agent is formed. In this case, the manufacturing process of the mold is significantly simpler than in the case described above. The lubricant discharge port is a single slit that extends around the entire circumference of the mold, but the width of this slit varies from forced cooling mold to forced cooling mold due to dimensional errors during mold manufacturing, resulting in variations in the amount of lubricant discharged. There are also variations. Furthermore, the slit width is small, about 0.02 to 0.2 ribs, and it is desirable that the parenthesized slit outlet be close to the inner edge of the upper surface of the forced cooling mold. If a village were to be stamped, part of the slit would become blocked and repair would be difficult.
If the lubricant remains partially blocked, the lubricant will not be supplied uniformly and the surface skin of the ingot will become rough (so-called twitchy skin occurs). It is an object of the present invention to provide an improved forced cooling mold which does not have the disadvantages of the forced cooling molds for semi-continuous casting of secondary vessels described above.

Another object of the present invention is that the manufacturing time is considerably shorter than that of the hole type, the variation in the amount of liquid lubricant discharged from mold to mold is small, and even if there is a dent on the upper surface of the mold, the discharge port To provide a forced cooling mold for semi-continuous casting in which partial blockage does not easily occur.

The forced cooling mold for semi-continuous casting according to the present invention has a supply flow channel that is closed on the inner surface of the forced cooling mold, and a supply flow channel that supplies liquid lubricant to the interface between the water cooling mold and the metal droplet. is formed between the forced cooling mold body and the removable annular part, and the portion near the closing of this supply flow is a groove formed at predetermined intervals in a radial direction from the center of the forced cooling mold over the entire circumference, and This is a forced cooling mold for semi-continuous casting, which is characterized by having a large number of openings.

The grooves described above are formed either in the forced cooling mold body or in the annular part, preferably by knurling, shaving or milling.

The forced cooling mold body is usually made of copper, which has good thermal conductivity, while the annular part may be made of copper or steel for ease of machining.

EMBODIMENT OF THE INVENTION Hereinafter, the aspect of the forced cooling mold for semi-continuous casting based on this invention is demonstrated based on drawing.

FIG. 1 is a perspective view showing a cross section of a forced cooling mold for semi-continuous casting according to a specific example of the present invention, and FIG. 2 is a perspective view of the forced cooling mold of FIG. 1 equipped with a refractory molten metal receiving tank. FIG. 3 is a partial cross-sectional view showing gas passages and liquid lubricant passages within the mold body.

The forced cooling mold for semi-continuous casting according to the present invention has a mold body 1
and an annular member 2, and has a cylindrical shape.

If the ingot to be cast is a round ingot, it has a cylindrical shape (
Fig. 1 shows a part of it), and if it is a rectangular ingot, it will have a rectangular tube shape. Inside the mold body 1, there is an empty arm through which a cooling medium (usually water) 3 flows, and the cooling medium 3 cools the mold body 1 and at the same time is ejected from a spout 4 to an ingot (not shown). to cool down. The casting body 1 is made of a metal that has good thermal conductivity and does not rust, such as copper or aluminum, and the annular member 2 is made of the same metal as the mold body 1 or a general structural rolled steel material that has been subjected to anti-rust treatment. Made. The annular member 2 is tightly fastened to the cast body 1 by a connecting member 5 such as a bolt.
The mold body 1 and the annular member 2 are fabricated and assembled so that a gap 6 is formed as shown in FIGS. 1 and 2 when the mold body 1 and the annular member 2 are fastened together. This gap 6 is a feeding passage for a liquid lubricant, for example, oil such as castor oil, and is closed to the inner surface of the forced cooling mold. According to the present invention, the portion near the opening of the supply channel 6 has a large number of grooves 7 (concave grooves in FIG. 1) in the mold body 1 radially from the center of the forced cooling mold and at predetermined intervals over the entire circumference. A large number of rectangular holes are arranged in a row around the entire circumference on the inner surface of the cooling mold. When such a forced cooling mold is used for making aluminum hot-top hokos, a metal melt receiving tank 8 (FIG. 2) made of a refractory is fixed on top of the mold body 1.

This flaw receiving tank 8 stores molten metal and prevents the solidification start surface from varying depending on the amount of poured metal. In addition, the burnt receiving tank 8
The inner circumferential surface of the mold is located inside the inner circumferential surface of the forced cooling mold, and the molten metal receiving tank 8 protrudes inward to form a so-called overhung portion. A gap 9 (FIG. 2) is formed between the molten metal receiving tank 8 and the spherical member 2 so as to introduce gas (for example, air) directly below this overhang portion. This gap 9
is a gas supply channel, which is connected to a gas supply source (not shown) via a gas passage 10 provided in the mold body 1. Further, the lubricant supply channel 6 is in communication with a lubricant supply source (not shown) via a liquid lubricant passage 11 provided in the mold body 1. Furthermore, although these gas passages 10 and liquid lubrication passages 11 are located on the same vertical plane in the partial cross-sectional view of FIG. 2, they are actually on the same plane because a connecting pipe (not shown) is attached to the mold body 1. It's better not to be there. In order to apply gas pressure uniformly to the molten metal, and to discharge the existing agent evenly from the holes in the grooves 7, the gas supply channel 9 must be
The gas flow 10 and the liquid lubricant passage 11 are designed such that the pressure loss in the flow passage connecting these becomes negligible compared to the pressure loss in the liquid lubricant supply flow rate 6. It is desirable to reduce the number of In the forced cooling mold described in connection with FIGS. 1 and 2, in which the leak-prevention ring 12 is arranged at the contact area between the mold body 1 and the annular member 2, the opening of the liquid lubricant supply channel 6 The surrounding area has a large number of concave grooves 7 in the radial direction, and these cores 7 are formed by processing the mold body 1, but the grooves 7 may also be formed in the annular member 2 instead of in the mold body 1. can.

Further, the groove 7 can also be a V-shaped groove, a U-shaped groove, a semicircular groove, etc. when viewed in cross section. Machining methods such as knurling, shaver machining, and milling can be applied to the groove 7. In other words. Knurling is a process in which a knurling jig is pushed onto the mold body 1 while rotating the mold body 1 about its central axis. By attaching the grooves, a large number of grooves can be formed at appropriate intervals in the radial direction from the center of the mold, and grooves can also be formed in the annular part 2 using the same machine. To form a groove with a shaver, set the coin mold body 1 on an indexing table, place it on the table of a shaping machine (shaver), cut the mold body 1 with the reciprocating motion of the cutting tool, and index it. The table can be rotated by a predetermined angle and cutting can be repeated. Furthermore, to form a groove using a vertical milling machine, set the mold body 1 or the annular member 2 on the indexing table, rotate the drill or bottom blade milling cutter, and cut by moving the table. The table can be rotated by a predetermined angle and cutting can be repeated. The above-mentioned processing method is considerably simpler and takes less time than the conventional drilling of multiple holes. Furthermore, if the annular member 2 is manufactured from a general structural rolled steel material (SS material), it can be manufactured more easily and at lower manufacturing cost than when manufactured from copper. Therefore, the forced cooling scale mold for semi-continuous casting according to the present invention can be made more easily than the conventional hole-type forced cooling mold, and the depth of the groove can be machined with high precision. There is no variation in the amount of liquid lubricant discharged as in a cooling mold, and even if there is an embossing, there is no clogging of the discharge port as in the secondary slit type forced cooling mold.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a cross section of a forced cooling mold for semi-continuous casting according to the present invention, and FIG. 2 is a partial sectional view of the forced cooling mold of FIG. 1 equipped with a refractory molten metal receiving tank. be. 1... Mold body, 2... Annular member, 3...
...Cooling medium, 5...Bolts, 6...
...Liquid lubricant supply channel, 7...Groove, 8...
...Kinarashi weld moat receiving tank made of refractory material, 9... Gas supply confluence channel, 12...○ ring. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A forced cooling mold for semi-continuous casting in which a supply channel for supplying a liquid pure lubricant to the interface between the forced cooling mold and the molten metal is opened on the inner surface of the forced cooling mold. A flow path is formed between the forced cooling mold body and a removable annular member, and the portion near the opening of this supply flow path is formed by grooves formed at predetermined intervals from the center of the forced cooling mold in a radial direction and over the entire circumference. A forced cooling mold for semi-continuous casting, characterized in that the opening is a large number of holes. 2. The forced cooling mold for semi-continuous casting according to claim 1, wherein the groove is formed in the forced mold body. 3. The forced cooling mold for semi-continuous casting according to claim 1, wherein the groove is formed in the annular member.