JP4114445B2 - Casting machine mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a casting machine mold used for a casting machine in which casting molds are connected in an endless track shape and continuously cooled and peeled from receiving molten metal, and particularly, the cooling efficiency of the casting mold is advantageously improved. Is.
[0002]
[Prior art]
When casting molten metal into a predetermined shape, place the mold in an endless track, pour the molten metal while continuously rotating it, cool it with water, etc., then cool the solidified metal from the mold A casting machine that peels and discharges is used. A typical example of such a casting machine is a casting machine in which hot metal is solidified to form a mold.
[0003]
The basic structure of such a casting machine is shown in FIG.
In this type of casting machine, the mold 1 is arranged in an endless track shape, and this is continuously rotated, and the molten metal 2 tilts the container 3, so that the mold 1 of the casting machine is passed through the rod 4. It is structured to be cast inside. The mold 1 is cooled while being carried by the rotation of the endless track, and the molten metal 2 in the mold is solidified. Usually, cooling water 6 is sprayed from above the mold 1 by the water cooling nozzle 5 in the middle of transfer to enhance cooling and promote solidification of the metal. When the mold 1 moves to the lower surface of the endless track at the end of the endless track, the solidified metal 2 'in the mold is peeled off from the mold and stored in the bag 7 or the like disposed below.
After that, the mold 1 moves in the opposite direction on the lower surface of the endless track, and is dried by the drying burner 8 or the like, and then goes around the upper surface of the endless track and receives the molten metal 2 pouring again.
[0004]
In a casting machine having such a structure, the molten metal cast into the mold is cooled by cooling by conduction heat transfer to the mold and by radiation to the atmosphere, convection heat transfer and heat removal by evaporation of sprayed cooling water, etc. And solidify. Among them, the conduction heat transfer to the mold is an important cooling means because of its large heat transfer coefficient.
[0005]
By the way, in such a casting machine, since the molten metal is poured into the mold a plurality of times until one batch of molten metal is cast, the mold is repeatedly heated and cooled by pouring. However, the mold temperature gradually increases during the cycle. When the temperature of the mold becomes high, there is a problem that the cooling of the molten metal is slowed down. However, when the mold temperature when the solidified metal peels from the mold becomes high, there arises a problem that peeling becomes difficult.
[0006]
Accordingly, it is desirable to enhance mold cooling during the mold temperature cycle during casting.
For example, for the purpose of enhancing the cooling of the mold, a special mold is proposed in which grid-like protrusions are arranged on the entire outer surface of the bottom of the mold (see, for example, Patent Document 1).
In this mold, a plurality of vertical protrusions and horizontal protrusions are arranged in a lattice pattern on the outer surface of the bottom, and when the thickness of the protrusion is t and the protrusion height from the outer surface of the mold is h, t / h = By considering the relationship between the mold thickness T and the projection thickness t as T / t = 1.0 to 2.5, the mold weight, material cost, thermal strain and cooling effect are taken into consideration. .
[0007]
However, this technique reduces the weight of the mold, increases the surface area by installing protrusions, and promotes the cooling of the mold while receiving molten metal by utilizing the effect as a rib, and improves the mechanical strength. The height h of the projection is 0.7 to 3.3 times as high as the thickness T of the bottom surface of the mold.
For this reason, the thermal stress applied to the protrusions is large as the mold is heated and cooled, and since the protrusions themselves have a lattice shape, the thermal stress applied to the intersection of the lattices is also large, so that the protrusions are deformed, etc. This technology is generally not widely used.
[0008]
[Patent Document 1]
JP-A-52-53725 (Claims, FIGS. 1 to 3)
[0009]
[Problems to be solved by the invention]
The present invention advantageously solves the above-mentioned problems, and the cooling efficiency of the mold is effective in the temperature cycle during casting without the risk of deformation due to thermal stress accompanying the temperature rise and cooling of the mold. It is an object of the present invention to propose a casting machine mold in which the solidified metal is easily separated from the mold by improving the efficiency of the casting machine.
[0010]
[Means for Solving the Problems]
That is, the present invention relates to a mold used in a casting machine that continuously connects a mold in an endless track shape and continuously cools and peels off the molten metal while rotating the endless track. On the back side of the casting surface that accepts water, surface irregularities are provided that undulate along the longitudinal direction of the mold, and side weirs are provided extending from the side surfaces of the mold. Is a casting machine mold characterized by forming.
[0011]
In the present invention, the height difference of the surface irregularities described above is preferably about 10 to 50 mm.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 2 schematically shows a preferred example of a casting machine mold according to the present invention. FIG. 4A shows a cross section along the longitudinal direction of the mold, and FIG. 4B shows a cross section along the width direction of the mold. Reference numeral 9 in the figure is a wave shape along the longitudinal direction of the mold. The surface irregularities formed on the surface and 10 are side weirs extending from the side surface of the mold.
[0013]
As shown in the figure, in the mold of the present invention, a wavy surface irregularity is provided on the back surface of the casting surface of the mold, and a side weir is provided. Therefore, if the mold moves to the lower surface of the endless track of the casting machine after the solidified metal is peeled from the mold, the mold is inverted and the back surface on which the wavy surface irregularities and side weirs are formed faces upward. It will be transported in the state.
[0014]
At this time, while the water cooling nozzle is present in the upper part of the casting machine, the cooling water flowing down the upper mold gap flows down on the reverse side of the mold in the inverted state. Cooling water accumulates in a recess formed by the side weir. The surface of the mold absorbs the sensible heat of the molten metal while the molten metal is received and cooled, and the temperature rises to about 400 to 600 ° C. Therefore, the cooling water stored in this depression is boiling Evaporate.
[0015]
In conventional molds with a flat back surface, cooling of the mold back surface was caused by the flow of cooling water at the position where the cooling water flowed from above, which contributed to cooling of the mold. When removed from the mold, the heat removal by the cooling water on the back of the mold immediately stopped.
On the other hand, in the present invention, since the recess formed by the corrugated surface irregularities and the side weir is provided on the back surface of the mold, the area where the cooling water flows down from above after the solidified metal is peeled from the mold is provided. While moving, the cooling water is stored in the recess, and the stored cooling water evaporates even after passing the cooling water flow area, thereby promoting the cooling of the mold.
[0016]
At this time, if there is too much cooling water stored in the depression, the molten metal leaks downward from the mold and flows down when the mold is further transferred and moved below the position where the molten metal is poured again. In this case, there is a risk of causing a steam explosion, but in this respect, the amount of water stored on the back of the mold can be controlled to an appropriate amount by setting the difference in level of the surface unevenness to about 10 to 50 mm. , Can avoid such danger.
[0017]
As described above, in the present invention, the wavy surface irregularities are provided on the entire back surface of the mold, and the depression is formed by this and the side weir extending from the side surface of the mold. Can do.
In the case of a conventional mold having a grid-like projection on the back of the mold, if the cooling water flows down when the mold is transferred in an inverted state, the cooling water is stored only in the center of the mold, and the surrounding area is cooled. Since there is no water and the thickness of the protrusions is relatively thin, thermal strain was likely to occur on the back of the mold. Since the mold can be cooled by one-way heat transfer from the mold to the mold surface, it is not easily deformed by thermal strain.
[0018]
【Example】
The hot metal was received from the hot metal ladle using a mold according to the present invention having the shape shown in FIG. 3 (difference in level of wavy surface irregularities: 40 mm) and a conventional mold with a flat mold back surface. The casting machine was 25m long and the cooling water sprinkling area was 12m.
Casting was performed under the above conditions, and after the mold was rotated three cycles, the surface temperature of the casting surface of the mold immediately before pouring the molten iron was measured with an infrared thermometer.
[0019]
As a result, the conventional mold with a flat back surface had a surface temperature of 87 ° C., whereas the mold having the back structure according to the present invention was much lower at 37 ° C.
For this reason, when the conventional mold was used, it was not possible to completely peel off in the peeling area of the casting machine. In the mold of the present invention, no such peeling failure occurred.
[0020]
【The invention's effect】
Thus, according to the present invention, the temperature rise of the casting machine mold can be effectively suppressed, and the mold temperature at the time of peeling of the solidified metal can be kept low, which facilitates the peeling of the solidified metal from the mold. .
In addition, according to the present invention, since the entire mold back can be cooled uniformly, the heat conduction in the mold becomes one direction, and the thermal strain in the mold is alleviated. As a result, the life of the mold can be improved.
Furthermore, according to the present invention, by appropriately adjusting the depth of the recess on the back surface of the mold, the mold is suitably cooled, and the cooling water remains on the back surface of the mold and prevents a steam explosion from occurring. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a basic structure of a casting machine.
FIG. 2 is a schematic view showing a preferred example of a casting machine mold according to the present invention.
FIG. 3 is a view showing the shape of a casting machine mold according to the present invention used in Examples.
[Explanation of symbols]
1 Mold 2 Molten metal 3 Container 4 樋 5 Water-cooled nozzle 6 Cooling water 7 Bag 8 Dry burner 9 Wavy surface irregularities
10 side weir

Claims (2)

A mold used in a casting machine that continuously cools and peels molten metal from receiving a molten metal while the mold is connected in an endless track shape and rotating the endless track, and has a casting surface that receives the molten metal. The back surface is provided with surface irregularities that undulate along the longitudinal direction of the mold, and is provided with side weirs extending from the side surfaces of the mold, and these surface irregularities and side weirs form depressions for storing cooling water. And casting machine mold. 2. The casting machine mold according to claim 1, wherein the height difference of the surface irregularities is 10 to 50 mm.

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