JPS6235853B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hopper device suitable for molding thin-walled cylindrical molds that are difficult to mold using molding sand containing a gas-hardening binder. Conventionally, when molds are made using foundry sand containing a gas-hardening binder, these foundry sands have poor fluidity due to the gas-hardening binder, making it difficult to keep the foundry sand in the desired state. Currently, most of the filling is done manually.
There were various problems, including forcing workers to perform harsh labor. The present invention has been developed in view of the above circumstances, and it is possible to quickly and efficiently distribute molding sand containing a gas-curing binder to every corner of the flask without bothering the operator. It is an object of the present invention to provide a hopper device that can be reliably filled.

The configuration of the present invention will be explained below based on examples. Reference numeral 1 denotes a model stand which is equipped with a decompression chamber 2 inside and has a plurality of ventilation holes 3 annularly spaced at approximately equal intervals to communicate with the decompression chamber 1 on the top surface. 1, a cylindrical model 5 having a configuration in which a large-diameter cylindrical member 4 and a small-diameter cylindrical member 4a are arranged concentrically is placed with its cavity portion 6 positioned in the ventilation hole 3.

7 is a hopper device detachably placed on the upper surface of the cylindrical model 5;
is a cylindrical member whose outer diameter is approximately equal to the outer diameter of the large-diameter cylindrical member 4 in the cylindrical model 5, and a truncated conical cylinder whose lower end diameter is approximately equal to the inner diameter of the small-diameter cylindrical member 4a in the cylindrical model 5. An annular hopper 12 with the members disposed concentrically and with an annular opening defined by the lower edges of both as an ejection port 12a, and an upper surface of which is hermetically fixed to the ejection port 12a of the annular hopper 12. It also comprises an annular frame 11 whose lower surface can be brought into airtight contact with the upper surface of the cylindrical model 5 and which has a decompression chamber 8 inside. A plurality of ventilation holes 10 communicating with the decompression chamber 8 are bored on the lower surface of the annular frame 11 at approximately equal intervals along the annular frame 11. It is designed to communicate with the upper end opening of the cavity part 6.

Reference numeral 9 denotes a molding sand supply pipe that vertically penetrates the annular frame 11. A plurality of the supply pipes 9 are arranged at approximately equal intervals along the annular frame 11, and the upper end opening is connected to the annular hopper. 12, and its lower end opening faces the discharge port 12a of the cylindrical model 5.
It is designed to face the upper end opening of the cavity part 6 at. Inside the annular hopper 12,
Foundry sand 13 containing a gas-curing binder is stored.

Decompression chambers 2 and 8 of the model stand 1 and the annular frame 11
One end of flexible branch pipes 14, 15 is connected to the side wall to communicate with the decompression chambers 2, 8, and the other end of the branch pipes 14, 15 is connected to a vacuum (not shown) via an on-off valve 16. It is connected to the main pipe 17 which is connected to the pump, and when the vacuum pump operates,
Negative pressure is applied within the reduced pressure chambers 2 and 8.

With this structure, the cylindrical model 5 is placed on the top surface of the model stand 1 with the cavity part 6 positioned in the ventilation hole 3, and the hopper device 7 storing the molding sand 13 is placed on the top surface of the cylindrical model 5 to place the casting. In the state shown in FIG. 1 in which the lower end opening of the sand supply pipe 9 and the ventilation hole 10 are positioned in the cavity 6, the on-off valve 1
6 is opened and a vacuum pump (not shown) is activated, the cavity part 6 of the cylindrical model 5 is connected to the model stand 1, the decompression chambers 2 and 8 of the hopper device 7, and the ventilation holes 3 and 10.
The molding sand 13 in the hopper 12 is
is instantly sucked and filled into every corner of the cavity 6 through the molding sand supply pipe 9. Thereafter, the hopper device 7 is removed from the upper surface of the cylindrical model 5, and a hardening gas is passed into the molding sand 13 in the cavity portion 6 to harden the molding sand. Next, a mold release operation is performed to take out the hardened mold, and the above operation is repeated thereafter.

In addition, when filling the molding sand 13 into the cavity part 6, in the above embodiment, the cavity part 6 is filled with molding sand 13.
Negative pressure was applied from both the top and bottom of the
Of course, either the lower surface or the upper surface may be used.

In short, the present invention provides a top surface of an annular frame that is provided with a vacuum chamber inside, has a plurality of ventilation holes communicating with the vacuum chamber on the bottom surface, and has a plurality of molding sand supply pipes that vertically penetrate the vacuum chamber. In addition, the discharge port of the annular hopper that stores the molding sand is positioned and connected, so that the molding sand can be sufficiently filled to every corner of the cavity without bothering the operator, creating a good cylindrical mold. It has excellent effects such as being able to efficiently produce products, and its contribution to this type of industry is extremely significant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. 8: Decompression chamber, 9: Foundry sand supply pipe, 10: Vent hole, 11: Annular frame, 12: Annular hopper, 12
a: Outlet.

Claims (1)

[Claims] 1 A hopper device 7 that is detachably placed on the upper surface of a cylindrical model 5 in which a large-diameter cylindrical member 4 and a small-diameter cylindrical member 4a are arranged concentrically, and the gap between them is used as a molding cavity part 6. A cylindrical member whose diameter is approximately equal to the outer diameter of the large-diameter cylindrical member 4 and a frusto-conical cylindrical member whose lower end diameter is approximately equal to the inner diameter of the small-diameter cylindrical member 4a are arranged concentrically. The annular hopper 12 is arranged so that the annular opening defined by the lower edges of both is the outlet 12a, and the upper surface is hermetically fixed to the outlet 12a of the annular hopper 12, and the lower surface is the annular hopper 12 of the cylindrical model 5. It consists of an annular frame 11 that can be brought into airtight contact with the upper surface and has a decompression chamber 8 inside, and a cavity part 6 of the cylindrical model 5 that communicates with the decompression chamber 8 on the lower surface of the annular frame 11. A plurality of ventilation holes 10 are bored at approximately equal intervals so as to be able to communicate with each other, and the upper end thereof is open to the discharge port 12a of the annular hopper 12, and the lower end thereof is openable to the cavity portion 6 of the cylindrical model 5. A plurality of molding sand supply pipes 9 are disposed at approximately equal intervals through the annular frame 11, communicate with the decompression chamber 8 on the wall surface of the annular frame 11, and an on-off valve 16 and a vacuum pump are sequentially connected. The hopper device is characterized by: