JPS6239062B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a mold and an apparatus therefor.

In recent years, the same applicant as the present application has applied for and published an innovative method for molding a mold. The molding method is as disclosed in Japanese Patent Application Laid-Open No. 54-38220, after casting molding sand is put into a casting flask combined with a model plate with exhaust holes, compressed air is applied to the surface of the molding sand. By letting the molding sand flow through the molding sand and discharging it from the exhaust hole of the model plate, the molding sand is densely packed, and then the molding sand is squeezed.
This is a molding method capable of molding a mold having sufficient hardness for a model plate having a model part with a high height and a complicated shape, without having to sand the molding sand.

By the way, in this molding method, depending on the pressure of the compressed air applied to the surface of the molding sand and the pressure of the compressed air discharged from the model board,
It depends on the quality of the molding condition. Therefore, in order to apply optimal compressed air with stable pressure to the foundry sand, consideration should be given to the capacity of the compressor, the capacity of the receiver tank, the diameter of the piping, etc. Also,
The compressed air discharged from the model board must be controlled, resulting in problems such as a complicated design of the device and an increase in the cost of associated equipment.

The present invention was made in view of the above circumstances, and
Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

Reference numeral 1 denotes a model plate having a predetermined model part 2 on its upper surface and a hollow chamber 3 formed in its lower part, and is placed on a table 5' which is raised and lowered by an upward cylinder 5 installed on a base 4. The upper surface of the model plate 1 has a plurality of exhaust holes 6 that reach the hollow chamber 3.
A vent plug (not shown) is fitted into the exhaust holes 6, 6. Further, the hollow chamber 3 of the model plate 1 is communicated with the atmosphere via a pipe 7 and an on-off valve 8. Further, above the model plate 1, a casting flask 9 is arranged which is placed on a conveyor (not shown) and can be moved and raised, and above the casting flask 9, a filling frame 10 which is suspended so as to be able to rise and fall is arranged. has been done. A cover member 11 that airtightly covers the upper end opening of the filling frame 10 is disposed above the filling frame 10 so as to be horizontally movable via a traveling truck (not shown). A squeeze plate 13 is provided within the cover member 11 so as to be movable up and down via a downward cylinder 12 provided on the cover member 11. Further, the inside of the cover member 11 is connected to a compressed air source (not shown) via a pipe 15 with an on-off valve 14. Reference numeral 16 denotes a ceiling portion of the base 4, and a molding sand inlet 17 is provided at a position directly above the filling frame 10 in the ceiling portion 16.
is formed.

Next, the operation of the device configured as described above will be explained. The model plate 1 is expanded by the extension of the cylinder 5.
is raised to a required height, and the casting flask 9 and filling flask 10, which have been moved onto the model plate 1 by a conveyor (not shown), are overlapped. (The cover member 11 is
(removed from position 7) Under this condition, normal green molding sand is supplied into the flask 9 and the filling frame 10 from the input port 17. Subsequently, after moving the cover member 11 above the filling frame 10, the cylinder 5 is further extended to raise the filling frame 10, the model plate 1, etc., and the cover member 11 is loaded on the filling frame 10. At the same time, the cover member 11 is brought into contact with the ceiling part 16 of the base 4, and the cover member 10, the flask 9, etc. are attached to the ceiling part 16.
and the model plate 1 to the state shown in the figure. Next, the on-off valve 8 is closed and the on-off valve 1 is closed.
4 was opened and compressed air was supplied into the airtight chamber 30 defined by the model plate 1, casting flask 9, filling frame 10, and cover member 11, and the pressure inside the airtight chamber 30 reached 5 kg/cm ² At this point, the on-off valve 14 is closed. After that, when the on-off valve 8 is opened, the compressed air in the airtight chamber 30 passes through the molding sand, the exhaust holes 6, 6, the hollow chamber 3, the piping 7, the on-off valve 8, etc. in this order, and is discharged into the atmosphere. As a result of the compressed air flowing through the molding sand, the molding sand is appropriately moved and densely packed along the surface of the model board 1. After the discharge of the compressed air is completed, the squeeze plate 13 is lowered by the extension operation of the cylinder 12 to squeeze the foundry sand, and after the squeezing is completed, the squeeze plate 13 is raised by the contraction operation of the cylinder 12. Next, the flask 9, model plate 1, etc. are lowered by the shortening operation of the cylinder 5, and the cover member 11, the filling frame 10, and the flask 9 are separated from each other, and the mold is removed, thereby completing one cycle. The mold made in this way had a hardness of over 80 degrees.

In addition, in the above-mentioned embodiment, the hollow chamber 3 is connected to the model plate 1.
However, it may be formed by a model plate and a table 5 to which the model plate is attached.
Moreover, the filling frame 10 may be omitted. The volume of the cover member 11 was set to be 1/3 or more of the entire airtight chamber 30 so that the amount of compressed air stored therein would not be insufficient.

As is clear from the above description, the present invention involves filling a molding flask combined with a model plate with molding sand, covering the upper surface of the molding sand with a cover member to form an airtight chamber, and removing the molding sand from the cover member. Compressed air is supplied to the airtight chamber, and when the compressed air reaches a predetermined pressure, the compressed air in the airtight chamber is discharged from the model plate to create a flow of compressed air in the molding sand in the direction of the model plate. Since the sand is pre-compressed and then the foundry sand is squeezed to form a mold, the compressed air supplied to the airtight chamber is stored, the pressure is adjusted to a predetermined pressure, and then applied to the foundry sand. Therefore, by temporally separating the supply air and exhaust air for the compressed air applied to the foundry sand, it is possible to remove the relationship between the supply air from molding performance, and reduce the compressor capacity, receiver tank capacity, and piping. This provides an excellent effect of being able to accurately mold a desired mold without considering the diameter or the like.

[Brief explanation of the drawing]

The drawing is a partially cutaway front view showing an embodiment of the present invention. 1: Model board, 3: Hollow chamber, 6: Exhaust hole, 8: Open/close valve, 11: Cover member, 13: Squeeze plate, 3
0: Airtight room.

Claims (1)

[Scope of Claims] 1. A casting flask combined with a model plate is filled with molding sand, and a cover member is placed over the upper surface of the molding sand to form an airtight chamber by the model plate, the flask, and the cover member. , supplying and filling the airtight chamber with compressed air from the cover member, and when the compressed air reaches a predetermined pressure, exhausting the compressed air in the airtight chamber from the model plate to compress it into the molding sand in the direction of the model plate. The method is characterized by creating an air flow to pre-compress the molding sand near the model plate to a high density, and then pressing a squeeze plate against the molding sand from above the flask to squeeze the entire molding sand. A mold making method. 2. A model plate is arranged so as to be movable up and down, and has a hollow chamber inside that communicates with the atmosphere through an on-off valve, and has a plurality of exhaust holes communicating with the hollow chamber from the surface. A mold making device characterized in that a cover member having a built-in squeeze plate is arranged so as to be horizontally movable relative to a model plate.