JPS5951385B2 - pouring equipment - Google Patents

Description

[Detailed Description of the Invention] This invention provides a mold or ladle with molten metal (hereinafter referred to as molten metal).
This invention relates to a pouring device that pours a fixed amount of hot water.

FIG. 1 shows a conventional pouring device.

In Fig. 1, 1 is a furnace body, 2 is a molten metal, 3 is a tap that communicates with the lower part of the furnace body 1 in a siphon shape, 4 is a nozzle embedded in the tip of the tap 3, and 5 is a thrust device. For example, it is a device such as an electromagnetic pump or a pressurized gas device that pushes up the molten metal 2 to a specified level in the tap 3 and maintains it.

Next, the operation in this conventional example will be explained.

When a mold or ladle (not shown) comes to rest under the nozzle 4,
The thrust device 5 operates, and the molten metal 2 is pushed up from the furnace body 1.
The melt rises into the outlet 3 and flows downward through the hole of the nozzle 4.

This outflow rate is generally called the pouring rate and must be determined to be the optimum value for each mold.

As is well known, the pouring rate Qkg/S is derived from the following formula.

Q=to, d2. v'head■ Here, k is a proportionality constant, d is the diameter of the hole of the nozzle 4 (hereinafter referred to as the aperture), g is the gravitational acceleration, and h is the height of the molten metal above the nozzle 4.

FIG. 2 illustrates this relationship.

When the mold is full, the thrust device 5 is stopped, the molten metal 2 is returned to the furnace body 1, and pouring is stopped.

However, the pouring device configured in this manner has the following drawbacks.

That is, (1) Taking cast iron as an example, if a low pouring rate of 1.5 kg/s or less is required, the accuracy of the pouring amount will deteriorate.

As is clear from Figure 2, the reason for this is that Q cannot be made small unless h and d are made small, but d is a problem due to the adhesion of slag, and the molten metal cools down and forms a solid substance that sticks to the nozzle, causing the nozzle to become unusable. There is a limit due to the problem of blockage, and generally 1
The limit is 6 to 18φ.

Therefore, the city is made smaller, and h is 1d to 1.
．． When it reaches about 5d, the molten metal swirls around the outlet,
Even if h changes dramatically, as can be seen from Figure 2, △Q/△h is a large region, so Q
The rate of change of will become large.

On the other hand, when a high pouring speed of 20 kg/s is required, as can be seen from Figure 2, the effect of increasing Q by increasing h is small because it is a 172nd power curve, and the nozzle diameter d will be made larger.

In fact, a pouring rate of 20 kg/S can only be obtained with a nozzle diameter of 50 mm and 100 mm L7)h.

However, even in this case, since h/d is as low as about 2, the accuracy is poor, and it is difficult to achieve an accuracy of ±5%, let alone ±3%.

In addition, increasing h requires a larger thrust source, which lowers the upper limit of the internal hot water level in the furnace due to the structure of the furnace, requiring an extra structure above the furnace, and in the case of an electromagnetic pump. for,
Since the power source is expensive, the economic burden becomes extremely large. ■ When the nozzle hole becomes worn out and needs to be replaced, the mold is right below it and gets in the way, so the pouring furnace is usually moved.
Move it away from the mold and replace it.

Since it must be moved in this way, a moving device is required.

This invention was made to eliminate these drawbacks; by installing the nozzle horizontally, we succeeded in eliminating eddy currents and significantly improved pouring accuracy at both low and high pouring speeds. The purpose is to obtain a hot-water pouring device.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of the present invention, and the furnace body 1 and thrust device 5 are not shown because they are the same as in FIG. 1.

2 is a molten metal, 3 is a tap, and 4 is a nozzle whose axis is placed horizontally.

With this configuration, the molten metal 2 flows out from the hole of the nozzle 4 at a rate Q shown in the equation below.

Q = k', d2. J toy W (kg/s) h', d
are shown in FIG. 3, and are the nozzle diameter and the hot water level height, respectively.

k' and g are a proportionality constant and gravitational acceleration, respectively.

In this case, since the direction in which the molten metal 2 flows out does not match the direction of gravity, no vortex is generated on the surface of the molten metal.

Furthermore, since Q (kg/s) is determined by h' from the center of the nozzle hole, even if h'/a is about 1, it is possible to pour the metal with very high accuracy.

That is, according to this configuration, in the region of low pouring speed, 0
．． Molten metal can be poured stably even at a rate of about 7 kg/s, and in the high pouring speed range, it can be poured accurately even at a rate of about 30 kg/s.

The accuracy that can be achieved will be between ±3% and 5%. In addition, the nozzle can be replaced even if the mold is directly below it.

In addition, stable pouring is possible even when the hot water surface height h' is low, so the nozzle diameter d can be selected as large as possible, and therefore the passage speed (m/S) in the nozzle hole is small. Become.

This greatly reduces wear of the nozzle material by the molten metal.

In experiments, it was found that the nozzle could last up to 10 shifts, compared to the conventional nozzle that could last only one shift.

This reduction in maintenance costs has a significant economic effect.

In addition, high pouring accuracy also improves yield, and the economic effects of this aspect are immeasurably large.

In this invention, since the nozzle is horizontal, the point at which the molten metal reaches moves at the beginning and end of the outflow, but this can be done by enlarging the sprue of the mold, guiding the melt into the mold with a gutter, etc. It can be dealt with.

However, the embodiment described below is also suitable for a small mold sprue.

FIG. 4 shows another embodiment of the invention.

1°5 is not shown but is the same as in Figure 1, 2, 3°4,
is the same as in FIG. 3, so the explanation will be omitted.

A second nozzle 6 is provided on the outflow side of the nozzle 4 and is perpendicular to the axis, and its diameter is considerably larger than that of the first nozzle 4.

By doing this, the molten metal 2 flowing out at a constant speed from the horizontal nozzle 4 can be made to flow down by vertically changing its direction so as to fit into the narrow sprue of the mold. without making it bigger, and without making it bigger.
You can take full advantage of the excellent effects shown in the diagram.

The diameter of the hole in the nozzle 6 is preferably larger than that of the nozzle 4 so that the molten metal 2 does not bulge thereon.

As described above, according to the present invention, by using an extremely simple configuration in which the nozzle that regulates the pouring speed is installed horizontally, it is possible to achieve a large improvement in performance as described above, and also to have a large economic effect. Obtainable.

It goes without saying that the same effect can be obtained by using a bucket or the like to guide the hot water flowing out from the horizontal nozzle to the mold.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional pouring device, Figure 2 is a diagram showing the relationship between pouring speed, surface height h, and nozzle diameter d.
The figure shows the tap of the pouring device of the present invention, and FIG. 4 shows the tap of the pouring device according to another embodiment of the invention. In the figure, 1 is a furnace body 2, molten metal, 3 is a tap, 4 is a nozzle, 5 is a thrust device, and 6 is a nozzle. Note that the same reference numerals in the drawings indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A furnace body holding molten metal, a tap hole connected to the lower part of the furnace body in a siphon shape, a nozzle provided at the tip of the tap hole, and a furnace body that holds the molten metal in the furnace body. In a pouring device that is equipped with a thrust device that pushes the molten metal up to a certain height inside the tap, and whose pouring speed is determined by the diameter of the nozzle and the height of the molten metal surface inside the tap, the axis of the nozzle is set horizontally. A pouring device characterized in that it is installed with a 2. A furnace body holding molten metal, a tap hole connected in a siphon shape at the bottom of the furnace body, a nozzle provided at the tip of the tap hole, and a nozzle that directs the molten metal in the furnace body to a certain height within the tap hole. In the pouring device, the pouring device is equipped with a thrust device for pushing up the molten metal, and the pouring speed is determined by the aperture of the nozzle and the height of the molten metal level in the tap, the first nozzle for determining the pouring speed into the tap. A pouring device characterized in that a second nozzle for regulating the outflow direction of the molten metal is mounted so that its axis is vertical.