JPH069734Y2 - Holding furnace of pressure casting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a molten metal holding furnace of a pressure casting machine used for producing a light alloy casting product.

[Prior Art] The entire structure of a conventional pressure casting machine is as shown in FIG.
The mold 25, the sleeve 23, the plunger 24, the first molten metal supply pipe 26, the second molten metal supply pipe 27, the electromagnetic pump 22, and the holding furnace 20.

To perform casting with this pressure casting machine, first, the holding furnace
Put molten metal 21 in 20 and apply air pressure to this holding furnace 20,
Then, the electromagnetic pump 22 is operated, the molten metal 21 in the holding furnace 20 is fed into the sleeve 23 through the second molten metal supply pipe 27 and the first molten metal supply pipe 26, and then the plunger 24 is operated to move the mold. The molten metal 21 is fed into the inside of 25 to cast the product.

[Problems to be Solved by the Invention] However, the pressure casting machine having such a configuration has the following problems.

(B) When the amount of the molten metal 21 in the holding furnace 20 changes, the molten metal supply pressure to the second molten metal supply pipe 27 naturally changes, so that the amount of the molten metal fed from the electromagnetic pump 22 to the sleeve 23 is not stable.

(B) Even when air is mixed in the molten metal 21, the electromagnetic pump 22 controls the amount of molten metal supplied by the driving time, so the amount of molten metal supplied to the sleeve 23 is insufficient. Will occur.

(C) As a result of these, it was unavoidable that defective casting products were generated due to excess and deficiency of molten metal supply.

The present invention makes it possible to always supply molten metal at a constant pressure from the holding furnace to the electromagnetic pump, and prevent air from entering the molten metal in the molten metal, thereby efficiently supplying casting products with few defective products. An object of the present invention is to provide a holding furnace for a pressure casting machine.

[Means for Solving the Problems] In order to achieve the above object, the holding furnace of the pressure casting machine of the present invention comprises the following.

In a holding furnace of a pressure casting machine having a furnace wall structure consisting of a refractory brick coated with casters on the inside, a heat insulating material wrapping the outer side of the fire resistant brick, and a steel skin wrapping the outer side of the heat insulating material: In the lower part of the furnace, they are connected to each other, but in the upper part of the furnace, they are separated by a partition wall into a pressure chamber and a constant molten metal surface chamber; In the furnace wall portion where the side furnace wall intersects, extending between the iron shell and the refractory bricks, one end is airtightly attached to the iron shell and the other end is airtightly attached to the refractory brick; The holding furnace structure of the pressure casting machine.

[Operation] In the holding furnace of the pressure casting machine according to the present invention described above, the holding furnace is separated into a pressure chamber and a constant temperature surface chamber, and the air pressure in the pressure chamber is controlled to melt the molten metal in the constant temperature surface chamber. Since the surface can always be kept constant, the molten metal pressure and amount supplied to the electromagnetic pump are stable.

Further, since the furnace wall in the part separated into the pressure chamber and the constant temperature surface chamber is completely air-shielded, it is possible to prevent air from mixing and flowing with the molten metal from the pressure chamber side to the constant temperature surface chamber side. ,
The molten metal containing air is no longer fed into the sleeve.

[Embodiment] A preferred embodiment of a holding furnace of a pressure casting machine according to the present invention will be described below with reference to FIGS. 1, 2, and 3.

FIG. 1 shows a cross section of a holding furnace of a pressure casting machine according to the present invention. In FIG. 1, 6 is a refractory brick of a furnace wall of the holding furnace. The overall shape is determined. Inside the layer of the refractory brick 6, casters 5 for increasing heat resistance and airtightness are applied with a constant thickness. The outside of the refractory brick 6 is covered with a heat insulating material 7. Reference numeral 8 denotes an iron skin that wraps the outside of the heat insulating material 7. The iron skin 8 reinforces and protects the layer of the refractory brick 6 through the heat insulating material 7, and constitutes the outermost portion of the furnace wall of the holding furnace. There is.

Reference numeral 2 denotes a partition wall of the holding furnace, and the partition wall 2 partitions the interior of the holding furnace into a constant molten metal surface chamber 1 and a pressure chamber 3. However, the constant bath surface chamber 1 and the pressure chamber 3 are connected to each other in the lower part of the holding furnace. The pressure chamber 3 exerts a pressure on the upper surface of the molten metal inside thereof to raise the liquid level of the molten metal inside the constant temperature surface chamber 1 to a constant level, and thereby keeps the liquid level of the constant temperature surface chamber 1 constant at all times. Have.

A molten metal supply pipe 13 for feeding the molten metal to a plunger (not shown in FIG. 1 but having the same structure as FIG. 4) of a casting machine is provided at the bottom of the molten metal level chamber 1 of the holding furnace. The molten metal can be supplied to the plunger of the casting machine by the electromagnetic pump 14.

In FIG. 1, a furnace wall portion C (furnace wall portion C) at a portion where a furnace wall portion A on the pressure chamber 3 side and a furnace wall portion B on the constant hot water surface chamber 1 side intersect with each other.
Includes both the furnace bottom wall and the furnace side wall), as shown in FIG. 2, the refractory brick 6 and the iron shell 8 are blocked by a blocking plate 9 for blocking the communication of air, Air passes through the heat insulating material 7 (the heat insulating material 7 is made of a material that allows air to pass through) from the furnace wall portion A on the pressure chamber 3 side to the constant hot water level chamber 1
The air is shut off so that it does not leak to the side wall B of the furnace. The blocking plate 9 extends between the iron skin 8 and the refractory brick 6, and one end thereof is welded to the iron skin 8 (the weld portion is denoted by a reference numeral
11), and optionally the weld 11 is further sealed with an air sealant. The other end of the blocking plate 9 is fitted into a groove formed in the refractory brick 6 and is sealed by an air sealing material 10. Therefore, the air from the pressure chamber 3 does not enter the constant bath surface chamber 1 through the wall of the holding furnace.

Reference numeral 4 denotes a furnace lid, which has airtightness and is firmly connected to the holding furnace main body portion by bolts or the like. Although not shown, the pressure chamber 3 controls the molten metal surface of the constant molten metal surface chamber 1, so that the air whose pressure is controlled by the pressure servo system is supplied from the upper part of the furnace.

FIG. 3 shows an example of an air blocking structure different from the example of FIG. 2, in which the bent portion 12 bent to the heat insulating material 7 side is bent in the iron shell 8 so as to further block the air and prevent it from entering. It is provided.

Next, the operation will be described. First by the electromagnetic pump 14
In order to accurately and accurately supply a constant amount of molten metal to a plunger of a casting machine, which is not shown in the figure, the distance H between the molten metal surface of the constant molten metal surface chamber 1 and the molten metal supply pipe 13 must be constant. Therefore, it is necessary that air does not enter the constant hot water surface room 1. Of these, in order to secure a certain level H
When a change from the target constant level occurs on the molten metal surface, a signal is immediately fed back, and an air flow control valve provided in an air supply circuit (not shown) that sends air to the air chamber 3a above the pressure chamber 3. (Not shown) operates to constantly control the pressure applied to the air chamber 3a so as to ensure a constant molten metal level in the constant molten metal level chamber 1.

In the conventional furnace wall structure, the only leakage of air from the pressure chamber 3 to the side of the constant temperature surface chamber 1 is the leakage of air through the permeable heat insulating material of the furnace wall. Since the plate 9 has a complete air shut-off structure, air leaking through the heat insulating material 7 on the furnace wall is completely prevented.

The holding furnace as described above is particularly suitable for a pressure casting machine for manufacturing a light alloy automobile wheel.

[Advantages of the Invention] According to the holding furnace of the pressure casting machine configured as described above, the level of the molten metal of the holding furnace to be supplied is always kept constant by the constant molten metal level chamber 1, and the furnace of the holding furnace is maintained. Since the wall is equipped with a blocking plate that blocks air leakage from the pressurizing chamber side A to the constant temperature side chamber side B, a constant amount of molten metal is constantly applied to the plunger of the casting machine without mixing air. It is possible to obtain a high-quality cast product that can be supplied and does not cause defective products due to excess or deficiency of hot water or air mixing.

[Brief description of drawings]

FIG. 1 is a sectional view of a holding furnace of a pressure casting machine according to an embodiment of the present invention, and FIG. 2 is a structure for shutting off air leakage from the pressure chamber side to the constant temperature side chamber side of the holding furnace wall. Fig. 1 near the
Fig. 3 is a partial sectional view taken along line II-II, Fig. 3 is a partial sectional view in the vicinity of an air leak shutoff structure according to another example different from Fig. 2, and Fig. 4 is a general sectional view of a conventional holding furnace and a casting machine. Fig. 1 …… Constant bath room 2 …… Partition wall 3 …… Pressure chamber 5 …… Caster 6 …… Fireproof brick 7 …… Heat-resistant material 8 …… Steel skin 9 …… Shutdown plate

Claims (1)

[Scope of utility model registration request] 1. A refractory brick coated with casters on the inside,
In a holding furnace of a pressure casting machine having a furnace wall structure composed of a heat insulating material wrapping the outside of the refractory brick, and a steel skin wrapping the outside of the heat insulating material: the holding furnace is a furnace which communicates with each other in the lower part of the furnace The upper part is separated into a pressure chamber and a constant hot water surface chamber which are separated from each other by a partition wall; of the furnace walls, at least the furnace wall portion where the pressure chamber side furnace wall and the constant hot water chamber side furnace wall intersect A shield plate extending between the iron skin and the refractory brick and having one end airtightly attached to the iron skin and the other end airtightly attached to the refractory brick. Holding furnace of pressure casting machine.