JP2001079646A - Method for finishing sand mold for casting and automatic mold shaping apparatus for sand mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for change of a squeeze head for each product and to mechanize the finishing work by fitting a sprue sleeve shorter than a molding flask height at the position of the sprue, filling molding sand into the molding flask, making it hard with a squeeze head, flatly scraping the molding sand to the upper end of the sprue sleeve, exposing the sprue sleeve and setting a sprue cup. SOLUTION: For example, a pattern 13 is set in the molding flask 11 and the molding sand 14 is filled. The sprue 15 is formed on the pattern 13 and the sprue sleeve 16 shorter than the height of the molding flask 11, is inserted into the outer periphery of the sprue 15. Successively, a sand mold is fitted to a pressing compressor to squeeze and harden the molding sand 4 with the squeeze head 21. The upper end surface of the sprue sleeve 16 is burried into the molding sand 14, and not broken with the squeeze head 21. Successively, the sprue position is decided and the molding sand 14 is scraped with a cutting tool fitted to a manipulator to expose the upper end surface of the sprue sleeve 16, and the sprue cup is fitted to the tip part of the sprue sleeve 16 with the manipulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sand mold used for casting a cast product, and more particularly to a method for treating a gate portion and an automatic sand molding apparatus which enable labor saving and further automation of sand molding. About.

[0002]

2. Description of the Related Art A sand mold of a casting product is prepared by placing a casting frame on a surface plate on which a model such as a wooden mold is placed, filling a gap in a mold with casting sand, and attaching the mold to a pressure compressor. It can be manufactured by a method of compacting molding sand with a squeeze head. According to this conventional method, a hole for pouring a molten metal (molten iron or the like) at the time of casting is also formed on the model, and a gate sleeve for preventing the wall of the gate from being collapsed when the molten metal is poured is previously provided at the gate portion of the model. It is fitted to.

Since the sprue sleeve is made of earthenware or formed by hardening sand, the sprue sleeve is not damaged when the casting sand filled in the casting frame is compacted with a squeeze head. Use a squeeze head. In addition, since the position of the gate differs for each casting product, in a mass production line in which many types of products flow in a mixed manner, each time the type of product changes, it has to be replaced with a squeeze head having an appropriate recess position. Instead of exchanging the squeeze head itself, there is a type in which a number of detachable frames are provided on the lower surface of the squeeze head, and the frame corresponding to the sprue portion is removed to compress the squeeze head.

FIG. 6 is a partial cross-sectional view showing a conventional example of a mold making apparatus in which the position of a gate is adjusted by a top to perform pressure compression. Place a wooden model or a plastic model with a sprue slave fitted in the sprue on the surface plate,
Fill with molding sand mixed with various binders in a flask. Next, pressure compression is performed using a squeeze head from which a frame corresponding to a gate is removed in advance. At the end of the sprue sleeve, a wide spout cup must be installed to make it easier to pour the molten metal.However, the contact surface between the sprue cup and the sand mold surface adheres so that the molten metal does not leak from the bottom of the installed sprue cup. You need to be.

[0005] However, in the sand mold compacted by the conventional method, the molding sand around the sprue sleeve is not compacted, the surface has irregularities, and the state differs depending on the sand mold. Therefore, as shown in FIG. 7, in response to the change in the sand mold, a finishing operation of collecting casting sand from the periphery around the gate sleeve, compacting the sand, flattening the surface, and placing the gate cup thereon is performed. You. Finally, after the sand is sufficiently hardened, the model is extracted, a coating agent is applied, and the upper and lower dies are clamped together to form a casting mold.

[0006] The finishing work of flattening the surface and placing the sprue cups needs to be performed flexibly in accordance with the individual sand molds having different spout positions and peripheral conditions. There was nothing else to do by hand. As described above, the replacement of the squeeze head and the finishing process have conventionally been restricted, and it has not been possible to automate the entire process of sand molding.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for eliminating the need for exchanging a squeeze head and enabling mechanization of a finishing operation in a sand molding process. The present invention is to provide an automatic sand mold finishing device used.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for sand-casting a casting according to the present invention comprises providing a sprue sleeve shorter than the height of a flask at a pouring gate, and filling molding sand in the flask. Then, it is compacted with a squeeze head, then flattened to the upper end of the buried sleeve centered around the pouring gate to expose it, and a sprue cup is installed.

According to the sand mold finishing method of the present invention, since the sprue sleeve is lower than the casting frame, the sprue sleeve is protected by the casting sand even when compacted by a squeeze head, thereby avoiding breakage. Therefore, since there is no need to form a concave surface corresponding to the position of the gate on the pressing surface of the squeeze head, there is no need to replace or adjust the position of the frame to be removed, and the same squeeze head can be used at any time. . In addition, since the casting sand around the gate is sufficiently squeezed, if the gate is scraped off with a rotary scraper to expose the gate sleeve, a sufficiently hard flat surface is formed around the gate, If the sprue cup is installed, the position of the sprue cup and the sprue coincide with each other, and the sprue cup is in close contact with the formed flat surface and is stabilized.

[0010] In order to solve the above problems, an automatic sand molding apparatus of the present invention comprises a pressurized compressor having a squeeze head, a manipulator, a manipulator control device, and a gate position determination device, and the squeeze head is cast at the position of the gate. A sprue sleeve shorter than the frame height is erected to compact a sand mold filled with casting sand in a casting frame, and a sprue position determination device determines a sprue position corresponding to the sand mold and generates an instruction signal, and controls the manipulator. The device drives the manipulator equipped with the rotary scraper based on the instruction signal to sharpen the sprue position to expose the upper end of the embedded sprue sleeve, and to flatten the upper end of the sprue sleeve exposing the sprue cup gripped by the manipulator. It is characterized by being installed on a surface.

According to the automatic sand mold making apparatus of the present invention, even when various sand molds are mixed and supplied, the sprue position judging device guides a cutting tool such as a rotary scraper or the like to the position of the sprue based on the information of the sand mold. Since the sluice sleeve is placed by forming a flat surface by digging up to the upper end surface of the mold, the sand mold finishing work, which was difficult in the past, was also automated, eliminating the need for workers' hands, and an automated robot that was robotized throughout the sand molding process. Work becomes possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings. FIG. 1 is a partial sectional view showing a pressurizing and compressing step in an embodiment of the present invention, FIG. 2 is a sectional view showing a state where a gate position is excavated by a rotary scraper, and FIG. FIG. 4 is a sectional view showing a sand mold completed in this embodiment, and FIG. 5 is a block diagram showing a sand mold finishing portion of the automatic sand molding apparatus in the embodiment of the present invention. To facilitate understanding, elements having the same functions are denoted by the same reference numerals in the respective drawings.

FIG. 1 is a drawing showing a state in which a sand is pressed from above a sand mold with a squeeze head to compact molding sand. The sand mold 1 is formed, for example, by placing a model 13 installed on a surface plate 12 in a casting frame 11 surrounding the periphery in a rectangular shape, and filling a gap portion thereof with casting sand 14. A gate section 15 is also formed on the model 13, and a gate sleeve 16 shorter than the height of the casting frame 11 is fitted around the gate section 15.

The sand mold is manufactured by compacting the sand 14 with a squeeze head 21 attached to a pressure compressor (not shown). A top 22 is attached to the entire pressing surface of the squeeze head 21 so that a similar pressing force acts on the entire surface of the casting flask 11.
When pressed and compressed in this manner, the upper surface of the sand mold 1 is entirely hard and flattened. At this time, the sprue sleeve 16
Is buried in the casting sand 14, so that the gate sleeve 16 will not be damaged even if it is compacted with the squeeze head 21 with the top 22 attached at the gate position.

Next, the sand mold 1 whose entire surface is compacted flat in the flask 11 is transported to the position of the manipulator 31 and a sprue cup is attached to the sprue. Manipulator 3
A cutting tool 34 is attached to one end. The cutting tool 34 is, for example, a cutting tool in which a plurality of blades are radially attached to a disk. When the disk is rotated and pressed against the surface of the molding sand, the molding sand is pushed away to form a cylindrical hole having a flat bottom surface. A rotating scraper can be used.

The gate position judging device 33 stores the position of the gate in correspondence with the sand mold which differs for each casting product. When the type of the sand mold and the installed position are known, the gate in the sand mold 1 is determined. The position can be determined and specified by a coordinate value or the like. Therefore, it is possible to easily cope with the case of finishing the gate section for the mixed flow. The manipulator control device 32 drives the manipulator 31 in accordance with the instruction signal from the gate position determining device 33 to move the gripping cutting tool 34 to the gate position, and as shown in FIG. 2, the upper end surface of the gate sleeve 16 is exposed. The casting sand 14 is dug up until it does. The hole that has been dug is a columnar space having a flat circular bottom with a sprue opened at the center and surrounded by a sprue sleeve 16.

Next, as shown in FIG.
In step 1, the sprue cup 17 is pushed into the hole formed in the casting sand 14 to complete the finishing work of the sand molding. The sand mold 1 thus formed is finally pulled out of the model 13 and removed from the casting frame 11 and applied with a mold wash to obtain a finished product as shown in FIG. In the sand mold 1 thus formed, the spout cup 1
Since the bottom surface of 7 is supported by the hard flat surface at the bottom of the hole and is stably in close contact with the tip of the sprue sleeve 16, the molten metal does not leak at the spout cup 17 even when the molten metal is poured. The operation of setting the sprue cup 17 in the hole may be performed by replacing the manipulator holding the cutting tool 34 with the sprue cup 17, or may be performed by a different manipulator.

[0018]

As described above, according to the method for sand-casting a casting and the automatic sand-molding apparatus of the present invention, conventionally, it is necessary to replace a squeeze head or to attach / remove a top for each product, or to process around a sprue. In such a case, automation of the sand mold manufacturing process, which has been difficult due to the need for manual labor, becomes possible, and the productivity of casting manufacturing can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a pressure compression step in an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a state where a gate position is excavated by a rotary scraper in the embodiment.

FIG. 3 is a cross-sectional view showing a state in which a sprue cup is placed on an upper end of a sprue sleeve in the present embodiment.

FIG. 4 is a sectional view showing a completed sand mold in the present embodiment.

FIG. 5 is a block diagram illustrating a sand mold finishing portion of the automatic sand molding device according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a state of sand molding by a conventional molding method.

FIG. 7 is a cross-sectional view showing a state of setting a sprue cup by a conventional mold making method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sand mold 11 Cast frame 12 Surface plate 13 Model 14 Casting sand 15 Sluice 16 Sluice sleeve 17 Sluice cup 21 Squeeze head 22 Top 31 Manipulator 32 Manipulator control device 33 Sluice position judging device 34 Cutting tool

Claims (2)

[Claims] 1. A sprue sleeve shorter than the height of a casting flask is erected at the position of the sprue, filled with casting sand in the casting flask, and compacted with a squeeze head. A method for sand casting a casting, characterized by flattening and exposing, and setting a gate cup. 2. A pressure compressor having a squeeze head, a manipulator, a manipulator control device and a gate position judging device. A squeeze head is used to compact the sand mold filled with the sand mold placed on the surface plate, and the sluice is buried by flattening the sluice position with a rotary scraper attached to the manipulator based on a command from the sluice position determination device. An automatic sand molding apparatus, wherein an upper end of a sleeve is exposed, and a gate cup gripped by a manipulator is set on a flat surface of an upper end of a sprue sleeve.