JPS60223643A - Method and device for molding continuous casting mold - Google Patents

Abstract

PURPOSE:To subject a tubular casting mold to reconditioning and finish molding without using a large-sized vessel and explosives by inserting a mandrel into the used or other tubular casting mold, putting the mold into a vessel filled with a liquid and exerting a high hydrostatic pressure thereto. CONSTITUTION:The mandrel 2 having a desired mold shape is inserted into the used tubular casting mold 1 or roughly molded tubular casting mold and both ends are closed with caps 3. Such assembly is put into the hermetic vessel 7 and is fixed. Water is introduced through an introducing port to fill the inside of the vessel 7 and the air in the vessel 7 is discharged through an air vent hole 12. A valve means is closed to actuate a hydraulic system, thereby transmitting the pressure to the water and maintaining the inside of the vessel 7 under the high pressure. The mold 1 is contracted by the high hydrostatic pressure induced in the vessel 7 so that the inside surface thereof is brought into tight contact with the outside surface of the mandrel 2. The inside of the vessel 7 is evacuated upon completion of the shrinkage and the assembly is taken out of the vessel. The mandrel 2 is removed from the mold 1 and the reconditioned and molded mold is recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for forming a continuous casting mold made of metal, and in particular, to a forming method and an apparatus for forming a continuous casting mold made of metal, particularly for the regeneration of a used tubular mold or for the finishing of a roughly formed tubular mold. The present invention relates to methods and apparatus.

During continuous casting, the inner surface of the tubular mold is damaged by molten metal and solidified metal, and the tubular mold itself is subject to thermal stress,
Irregular deformation occurs due to pulling force, etc., and after repeated use, it eventually becomes unusable.

In order to recycle and use these used molds, we have
A mandrel whose surface has a smooth shape that matches the shape inside the mold is inserted into the mold, explosives are loaded onto the outside surface of the mold, these are immersed in liquid, and the explosives are detonated until the mold is brought into close contact with the mandrel. A method of correcting the shape of the mold and its inner surface by compression has been adopted (see, for example, Japanese Patent Publication No. 5B-51777). However, with this method, there are problems such as environmental problems such as noise caused by the explosion of explosives, the need for specially qualified personnel regarding explosives, and the need for large containers made of high-quality materials that can withstand the vibration waves caused by explosions. be.

On the other hand, for the finishing of rough-formed tubular molds, it is conceivable that the above-mentioned explosive forming may be applied, and it goes without saying that the same problems as in the case of recycling tubular molds exist in this case as well.

The present invention has been made to solve the above problems,
After inserting a mandrel having a smooth shape that matches the desired internal shape of the mold into a used tubular mold or a roughly formed tubular mold, and placing the tubular mold with the mandrel inserted into a container filled with liquid.

It is characterized by applying high hydrostatic pressure to the outer periphery of the tubular mold.

Another object of the present invention is to provide an apparatus for using the above-mentioned mold forming method. Therefore, the forming apparatus of the present invention includes a closed container filled with water, and a high pressure applied to the closed container. Consists of a hydrostatic pressure generator that generates hydrostatic pressure,
The hydrostatic pressure generating device is characterized by having a hydraulic pump, a pressure intensifier, and a converter that converts the hydraulic pressure increased by the pressure intensifier into water pressure.

Next, an embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a longitudinal sectional view showing a state in which a mandrel is inserted into a used tubular mold.

The tubular mold 1 is generally made of copper, and in this embodiment has a bent pipe shape. Preferably, the inner surface of the tubular mold 1 is lined with a wear-resistant metal layer, such as a chrome plating layer.

As a result of using the tubular mold 1 for more than 150 pieces,
The inner surface or lining is worn out and is no longer usable. The mandrel 2 is preferably made of hard metal and its outer surface is machined to exacting tolerances to match the inner surface of the recycled tubular mold. This mandrel 2 is loosely fitted into a tubular mold 1 to be regenerated, and both ends of the mandrel 2 are closed with lids 3, 3. Lid 3
．． 3 has dimensions that match the outer shape of both ends of the tubular mold 1,
A bolt hole is provided in the center. Bolts 4, 4 are inserted into these bolt holes to fix the lids 3, 3 to the mandrel 2, and the edges of the lid 3.3 press and fix both ends of the tubular mold 1. For example, PT on each joint or pedestal part.
An O-ring 5 made of FE (trade name: Teflon) is interposed. Further, air chambers 6 are bored at both ends of the mandrel 2, and the tubular mold 1. When the assembly consisting of mandrel 2 and lid 3 is immersed in liquid, it acts as an escape chamber for residual air.

Next, a closed container for accommodating the above assembly and applying an impact force and a hydrostatic pressure generating device will be described.

FIG. 2 is a longitudinal sectional view showing an example of a closed container, and FIG. 3 is a schematic diagram showing an example of a hydrostatic pressure generating device.

The outer peripheral cell of the airtight container 7 is composed of three cylindrical cell plates 8.8'
, 8'' are formed by shrink-fitting them respectively.The inner wall of the upper and lower ends of the innermost cell plate 8'' has an annular portion side 1
0.10 and mirror plates 9, 9 are each attached with a step difference. Further, an O-ring 11°11 is fitted between the end plates 9, 9 and the cell plate 8'' to keep the container in a sealed state.The upper end plate 9 is provided with an air vent hole 12. It is connected to the valve means 13 to prevent water in the container 7 from spouting out even when pressurized.A supply water inlet 14 and a pressurized water inlet 15 are provided at the lower part of the outer cell of the closed container 7.
are provided with a water supply source (not shown) and hydraulic pressure, respectively.
It communicates with the hydraulic converter 16. The hydraulic pressure-hydraulic converter 16 separates oil and water by an oil-water separation membrane 21, and has a function of converting the hydraulic pressure increased by the hydraulic system into water pressure. The hydraulic system has an oil tank 17. Hydraulic pump 18° pressure accumulator 19. It consists of a pressure intensifier 20 , the discharge side of which is connected to the hydraulic-hydraulic converter 16 .

Next, the operation of the above structure will be explained. First, a mandrel 2 having a shape that matches the shape inside the mold after regeneration is inserted into the used tubular mold 1, and both ends are closed with lids 3, 3, and the above assembly (the (see Figure 1). In addition, tubular mold 1
When the mold has a rectangular cross section, it is preferable to make the mandrel about 0.2% smaller than the finished internal dimensions of the recycled mold in consideration of springback at the corners when pressure is applied.

Next, the assembly is placed in the closed container 7, and the fixed end plate 11 and the annular portion side 10 are attached to the cell plate by appropriate means (not shown). Water is introduced into the closed container 7 through the supply water inlet 14 and filled. At this time, the air inside the container is discharged outside the container through the air vent hole 12. When the air is completely exhausted, the valve means 13 is closed and the hydraulic system is activated. The pressure of the oil increased by the hydraulic system is transferred to water by the hydraulic-hydraulic converter 16 to maintain the inside of the closed container 7 at a high pressure.

Due to the high hydrostatic pressure generated within the closed container, the tubular mold 1 is contracted, and its inner surface is brought into close contact with the outer surface of the mandrel 2. The required hydrostatic pressure may be calculated from fracture mechanics, but it is preferable that the hydrostatic pressure be such that the scratches on the inner surface of the tubular mold are completely compressed. Since the copper of the tubular mold 1 has a hardness of HBO2-100 and a strength of about 2200 kg, a hydrostatic pressure of about 3000 kg is sufficient, but the hydrostatic pressure is not limited thereto and can be selected as appropriate depending on the type of target mold and the degree of wear. can. When shrinking the tube, the inner surface of the mold and mandrel 2
The air existing in the gap between the two is evacuated into the air chamber 6 to prevent scratches caused by residual air. When the tube shrinking step is completed, the pressure inside the closed container is reduced, the end plate 10 is removed, the assembly is taken out, and the mandrel 2 is removed from the tubular mold 1, thereby recovering the regenerated mold. As detailed above, the present invention utilizes hydrostatic pressure compared to the conventional explosive condensation method, which avoids the problem of pollution caused by explosion noise, and also eliminates the generation of shock waves due to explosions, making it possible to reduce airtightness of closed containers. It is possible to significantly reduce the dimensions. -For example, inner diameter 155mm,
When regenerating a tubular mold with an outer diameter of 175 mm and a length of 800 mm, the height is reduced by 1 compared to the explosion tube shrinking method.
1/0. A container that is 1/10th the diameter is sufficient.

Although the above embodiment describes a curved pipe mold, the present invention can be applied to a straight pipe mold as well.
It is possible to directly increase the pressure of water without using the hydraulic system as in the above embodiment, or vice versa, and it is also possible to use only oil, and it goes without saying that this also falls within the technical scope of the present invention. Further, although the above embodiments only refer to the regeneration of used tubular molds, the present invention can be applied as is to finishing of rough-formed tubular molds, and in that case, exactly the same effect can be obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a state in which a mandrel is inserted into a used tubular mold according to the present invention, Fig. 2 is a longitudinal cross-sectional view showing an example of a closed container according to the present invention, and Fig. FIG. 4 is an enlarged sectional view showing the hydraulic-hydraulic converter of FIG. 3. FIG. i ------- One tubular mold 2-1111 Mandrel 3--・-M7・-- Sealed container 8.8', 8''-- Shell plate 9----- End plate 16-・-Hydraulic pressure-hydraulic converter 20
・-・・- Pressure booster Fig. 2 Fig. 1

Claims (1)

[Claims] (1) Insert a mandrel with a smooth shape that matches the desired internal shape of the mold into a used tubular mold or roughly formed tubular mold, and with the mandrel inserted, place the tubular mold into a container filled with liquid. (2) A method for regenerating a continuous casting mold characterized by applying high hydrostatic pressure to the outer periphery of the tubular mold (2) applying high hydrostatic pressure to a closed container filled with water and the open container. A mold for continuous casting, characterized in that the hydrostatic pressure generating device has a hydraulic pump, a pressure intensifier, and a converter that converts the hydraulic pressure increased by the pressure intensifier into water pressure. Molding equipment