JPH09271890A - Molten metal pouring hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molten metal pouring hole obtaining good maintenance and repeatedly useable at low cost without entrapping the air, gas, etc., at the time of pouring the molten metal by arranging a fall-down preventing means of a refractory on the surface of a sprue bush covering the surface with the refractory material. SOLUTION: A mold 5 forming mold gap parts 4 communicated with runners is arranged in a charging part 2 arranging the molten metal pouring hole 1. In the charging chamber for reducing pressure casting, the surface of the sprue bush 7 of the molten metal pouring hole 1 is covered with the refractory material 9 and further, the fall-down preventing means 8 of the refractory material is arranged on the surface. As the fall-down preventing means, e.g. gauze, groove having projecting and recessing parts, tapered surface, etc., are desirable. Further, the sprue bush is desirable to constitute with a cylinder and a flange made of non-permeable material. Further, the refractory material is desirable to facilitate formation, repairing, regeneration, etc., by using cold box sand, alumina, ceramic fiber, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouring spout used when a casting is produced by pouring a molten metal into a mold in a gravity casting method, a differential pressure casting method or the like.

[0002]

2. Description of the Related Art The general procedure for making castings is
First, a mold is made using a model, then the molten metal is poured from the pouring port provided in the mold into the cavity part of the mold through a ladle, etc. After cooling, heat treatment, casting finishing etc. After that, the casting is completed. Here, the pouring port is used for pouring the molten metal into the mold efficiently in a short time and producing a sound casting.

The casting method of castings includes a gravity casting method utilizing the self-weight of the molten metal and a differential pressure or vacuum casting method utilizing the pressure difference, but in any case, a pouring port is required in association with the mold. Is.

The simplest pouring port of the gravity casting method is as follows:
There is a method in which the size of the upper part of the sprue located at the upper part of the mold is made larger than the diameter of the spout, and the pouring port is directly provided on the upper part of the mold. In addition, depending on the material of the molten metal, there is also a method of pouring the molten metal by providing a tap hole (including a hook) on the upper part of the mold. This take-up spout is usually made of unglazed earthenware (pole cup) formed of a refractory material, a self-hardening sand mold, or the like, but it is generally disposable.

On the other hand, in the differential pressure or vacuum casting method, the molten metal is generally poured into a mold through a filling pipe (stoke). The filling pipe is made of heat-resistant steel or fire-resistant sialon, or those. It is made of composite materials. Regarding the shape, for example, this disclosure example is shown in the drawing of Japanese Patent Publication No. 6-85990.

FIG. 6 is an example of disclosure disclosed in Japanese Patent Publication No. 6-85990. The mold 30 is arranged at a prescribed position in the loading chamber 31. The inside of the mold 30 is decompressed by a decompression device (not shown) via the connector 32 located above the loading chamber 31 and the conduit 33. As a result, the molten metal 35 in the crucible 34 is decompressed and sucked to the lower end 37 of the opening of the mold 30 via the filling pipe 36, and further guided to the mold cavity 38 to complete the pouring work.

[0007]

There are various problems in such a conventional pouring spout. For example, in the method of directly forming the pouring port on the upper part of the upper mold, when the pouring work is performed at a very high temperature, there is a concern that the refractory degree of the molding material is insufficient. In addition, if there is no room in the height of the mold compared to the size of the cavity in the mold, the pressure due to the flow of molten metal during pouring (insufficient pouring head) will occur and a healthy product will be obtained. Is difficult. As a measure against this, a tap is used, but in many cases it is disposable, which is an economic problem.

Further, the filling pipe made of sintered heat-resistant steel or refractory material used in the differential pressure casting method is expensive, and even if it is repeatedly used, the entire filling pipe has to be discarded at the end. However, depending on how it is used, there are economic doubts, and even when it is disposed of, it must be managed separately depending on its material, which is complicated. Also, care must be taken in the management of sintered products such as sialon so that damage such as cracks does not occur.

The present invention has been made in view of the above-mentioned problems, and there is no entrapment of air, gas, etc. during the pouring work, and only the consumable part of the pouring port is repaired with good workability.
It is to provide a pouring spout that can be recycled and used.

[0010]

In order to solve the above problems, the present inventor analyzed the material and shape of the pouring spout, and in order to make it possible to repeatedly use the sprue at low cost, pouring with a sprue bush made of steel and a refractory material. It was noticed that the sprue was formed and the refractory material did not peel off from the surface of the sprue bush.

First, the pouring spout according to the present invention is a pouring spout in which the surface of the sprue bush is covered with a refractory material, and means for preventing the refractory material from falling off is provided on the surface of the sprue bush. The basic shape of the sprue bush is composed of a cylinder and a flange.
A shape in which a flange is provided on one end surface of the cylinder is desirable.
Also, in the case of the differential pressure casting method, if the pouring port is made of a material having air permeability, when the molten metal is sucked, air or gas penetrates the pouring port and is sucked into the mold together with the molten metal. It may cause the occurrence. Therefore, it is preferable that the gate bush is made of a non-breathable material. The drop-off preventing means is not particularly limited as long as the refractory material does not come off or fall off the surface of the sprue bush.

Next, a wire mesh is used as the fall-out preventing means. The wire mesh is fixed to the surface of the sprue bush by welding or screws. If the wire mesh diameter and mesh size are too fine, it will be difficult for the refractory material to adhere, so the wire mesh should be made a little larger. The use of expanded metal is preferred.

Further, the drop-out preventing means is an uneven groove. Grooves may be formed by welding round iron or square iron on the surface of the sprue bush, but when finishing the sprue bush by machining, it is easier to work with a bite. is there. The groove shape may be a spiral screw shape.

Further, the drop-out preventing means is formed by a tapered surface. The shape of this tapered surface in the differential pressure casting method is that the inner diameter surface of the sprue bush has a large diameter on the side where the flange for mounting the spout is attached to the loading chamber, and conversely the outer diameter surface of the sprue bush has a flange. It is a preferable shape to prevent the refractory material from falling off by forming the side where it is arranged to have a small diameter.

Incidentally, the inner or outer surface of the sprue bush may be further provided with irregularities or screw-like grooves after the taper as described above. The details will not be questioned as long as the refractory material adheres to and can be prevented from falling off.

[0016]

FIG. 1 is a block diagram showing an embodiment of the present invention.
5 will be described in detail, but the present invention is not limited to these.

1 to 5 show an embodiment of the present invention. FIG. 1 is a partial cross-sectional view showing a state in which a pouring spout is attached to a differential pressure casting loading chamber, FIG. 2 is a partial cross-sectional view of a sprue bush provided with a wire mesh, and FIG. 3 is a partial cross-section with a groove. FIG. 4 shows a partial sectional view in which a tapered surface is provided. Further, FIG. 5 is a partial cross-sectional view of a state in which the pouring port is placed on the upper part of the mold for use in the gravity casting method.

[0018]

First Embodiment First, the pouring port 1 is attached to a lower portion 3 of a differential pressure casting loading chamber 2 with a bolt (not shown). Then, a mold 5 having a mold cavity 4 is loaded into the loading chamber 2 via a seal material 6. Pouring spout 1 is sprue bush 7
And a fall prevention means 8 and a refractory material 9. The sprue bush 7 is manufactured by cutting a steel pipe of the cylindrical portion 10, and the flange 11 is integrally formed by cutting a steel plate and welding.
The fall-out prevention means 8 is a wire mesh (expanded metal / XS3
1) After cutting 12 to a specified size, it was fixed to the inner and outer diameter surfaces of the sprue bush 7 by welding. The refractory material 9 was molded using the cold box sand 13. In this state, the pouring port 1 was attached to the lower part 3 of the loading chamber 2 with a bolt, the mold 5 was loaded, and then the pouring port 1 was immersed in the molten metal at 1550 ° C., and the inside of the mold 5 was depressurized to perform the pouring work. . No damage was observed in the pouring spout 1, and since the sprue bush 7 was made of non-breathable steel material, a sound product free from defects such as blow holes was obtained. Further, since the falling prevention means 8 (the wire net 12) is provided on the surface of the sprue bush 7, the pouring spout 1
The refractory material 9 did not peel off or fall off the sprue bush 7 even if vibration, shock, or the like was applied to it. Since cold box sand 13 was used as the refractory material 9, melting damage was partially observed during repeated use, but repair and re-use were possible.

[0019]

[Embodiment 2] Next, as shown in FIG. 3, the drop-out preventing means 8 was formed by the concave and convex grooves 14. After welding and assembling the cylindrical portion 10 and the flange 11 made of steel pipe, a groove having a width of 5 mm and a depth of 2 mm was machined into the inner and outer diameter surfaces of the cylindrical portion 10. Then, the refractory material 9 was covered with the concave and convex grooves 14 to complete the pouring port 1. The refractory material 9 is an amorphous refractory material whose main component is alumina, is stamped, dried, and then, similarly to the first embodiment, the lower portion 3 of the loading chamber 2.
It was arranged in the and the pouring work was carried out. It survived 120 times of repeated pouring work, and the pouring port 1 was sound except for slight melting loss.

[0020]

[Third Embodiment] Next, as shown in FIG. 4, the falling-off preventing means 8 is formed by a tapered surface 15. After welding and assembling the cylindrical portion 10 and the flange 11 made of steel pipe, a taper was machined into a taper on the inner and outer diameter surfaces of the cylindrical portion 10. Inner diameter taper is upper end 1
1/50 so that the 6 side has a larger diameter than the lower end 17 side
Taper. Further, the outer diameter surface is tapered by 1/50 so that the upper end portion 16 side has a smaller diameter than the lower end portion 17 side. Then, the taper surface 15 was covered with the refractory material 9 to complete the pouring port 1. The refractory material 9 was composed of ceramic fibers as a main raw material, and after being molded and dried, the refractory material 9 was placed in the lower portion 3 of the loading chamber 2 in the same manner as in Example 1, and a pouring operation was performed. Withstanding 80 times of repeated pouring work, the pouring spout 1 was sound with no peeling or falling off.

[0021]

[Embodiment 4] FIG. 5 is a partial sectional view of the pouring spout 1 when the pouring spout 1 is placed on the upper part of the mold 5 which is a gravity casting method. The sprue bush 7 is formed so that the upper end 16 of the cylindrical portion 10 has a large diameter and the lower end 17 has a small diameter, and a flange 11 is welded and fixed to the lower end 17. As the fall-off preventing means 8, a plurality of mild steel rods 18 having a diameter of 5 mm were arranged on the inner diameter surface and a part of the outer diameter surface of the cylindrical portion 10 so as to be in a contour line (parallel) with the flange lower surface 19 and welded and fixed. After that, the refractory material 9 was stamped so as to cover the mild steel rod 18 and the flange lower surface 19, and the pouring port 1 was completed. As the refractory material 9, cold box sand similar to that used in Example 1 was used, but repairing and reworking were sufficiently possible because only partial melt damage was observed when the pouring operation was repeated. Next, the refractory material 9 was molded with the same ceramic fiber material as in Example 3, and after drying 1
The pouring work was repeated at 555 ° C. As a result, as in Example 3, the pouring mouth 1 was sound and did not peel off or fall off.

[0022]

The pouring spout of the present invention has a spout made of a steel sprue bush and a refractory material, and is provided with a fall prevention means, so that it can be repeatedly used at a low cost, and the refractory material peels from the spout bush. There is no need to worry about falling out. Moreover, even if a refractory material having a low degree of fire resistance is used, it can be easily repaired and repaired.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a state in which a pouring port of the present invention is attached to a vacuum casting loading chamber.

FIG. 2 is a partial cross-sectional view of a sprue bush having a wire net according to the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a second embodiment of the present invention in which a groove having irregularities is provided.

FIG. 4 is a partial cross-sectional view of a third embodiment of the present invention in which a tapered surface is provided.

FIG. 5 is a partial cross-sectional view of a state in which a pouring port is used in a gravity casting method according to a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view of a state in which a molten metal is vacuum-sucked into a mold using a conventional filling pipe.

[Explanation of symbols]

 1: pouring spout 2: loading tool 3: lower part 4: mold cavity 5: mold 6: sealing material 7: spout bushing 8: fall prevention means 9: refractory material 10: cylindrical part 11: flange 12: wire mesh 13: cold box Sand 14: Uneven groove 15: Tapered surface 16: Upper end 17: Lower end 18: Mild steel rod 19: Flange lower surface

Claims (4)

[Claims] 1. A pouring spout in which the surface of the sprue bush is covered with a refractory material, wherein the spout of the refractory material is provided on the surface of the sprue bush. 2. The pouring spout according to claim 1, wherein the drop-off preventing means is a wire mesh. 3. The pouring spout according to claim 1, wherein the drop-out preventing means is an uneven groove. 4. The pouring spout according to claim 1, wherein the drop-out preventing means is a tapered surface.