JPH01166856A - Casting method - Google Patents

Abstract

PURPOSE:To simplify a casting equipment by casting with fixing a cover body to a casting frame after forming a mold and functioning the passage of the cover body as an air vent in the molding machine filling a hardening gas in a casting sand via the passage which is provided on the cover body. CONSTITUTION:A cope fixes a pattern 2 on a plate base 1, surrounding it by a molding flask 3. The casting sand 4 contains a gas hardening hardener and an iron powder 5 reduces the consumption of the casting sand 4. A cover body 6 has a gas passage 61, blowing an amine gas via a gas branch path 62. There is a gas suction path 11 on the plate base 1 and it opens in the casting frame 3 via the gas branch path 12, assisting the hardening of the casting sand 4 by sucking the amine gas. The drag is also formed similarly, made a drag B by reversing and fixing a cope A by placing it thereon. A molten metal receiver 72 is installed on a molten metal pouring cover 7 to pour the molten metal M in a cavity C. The inside of the mold 3 is made a negative pressure via the gas passage 61 to exhaust the reaction gas that the hardener is burnt by its overheating. The casting equipment can thus be simplified because the passage of the cover body functions as an air vent.

Description

[Detailed description of the invention] (Purpose of the invention) [Industrial application field] This invention relates to a casting method.

[Prior art]

Casting requires a mold. In order to manufacture this mold by, for example, a cold box method, the foundry sand is made to contain a gas hardening agent, and the foundry sand is hardened by supplying amine gas.

For this reason, the mold forming apparatus is characterized by an amine gas supply means (Japanese Patent Laid-Open No. 57-75249).

On the other hand, when casting is performed using the mold, the curing agent is overheated and generates a reaction gas. This gas causes casting defects.

For this reason, conventionally, a casting apparatus has been provided with a gas venting means to remove this reaction gas.

[Problems with conventional technology]

However, in the past, the amine gas supply means of the mold forming apparatus and the reaction gas degassing means of the casting apparatus were completely independent, resulting in the disadvantage that the casting equipment became complicated.

(Structure of the Invention) [Means for Solving the Problems] This invention has been made to solve the above-mentioned disadvantages, and has the following structure: placing the model and the flask on a plate stand and arranging the flask to surround the model; covering the surface of the model with molding sand; and sealing the opening of the flask with the lid; In a mold forming apparatus that provides a passage in the lid and fills the molding sand with a hardening gas through the passage, the mold is fixed to the flask after molding, and the lid is attached to the flask. This is a casting method characterized by subjecting the body to casting while remaining fixed.

[Action of the invention]

Since the casting method according to the present invention is configured as described above, the passage of the lid functions as a gas venting passage during casting.

[Description of Embodiments] The present invention will be described in detail below based on FIGS. 1 to 5.

FIGS. 1 and 2 show the process of forming an upper mold for casting.

In FIG. 1, reference numeral 1 indicates a plate stand, and reference numeral 2 indicates an air-permeable model fixed to the plate stand 1. This model 2 has a runner forming part 21. 3 is a casting flask, and the plate stand 1
It is placed in close contact with the This flask 3 surrounds the model 2. 4 is foundry sand, which covers the surface of the model 2. This foundry sand 4 contains a gas hardening agent.

A plurality of iron grains 5 are placed outside the molding sand 4 and packed into the flask 3. The plurality of iron grains 5 are used to reduce the amount of foundry sand 4 used. Reference numeral 6 denotes a lid, which is placed on the flask 3. This lid body 6 is hermetically sealed against the flask 3. 61 is a gas passage;
It is formed in the thick part of the lid body 6. This gas passage 6
Amine gas (corresponding to the "curing gas" of this invention) is blown into 1 through a valve (not shown).

Reference numeral 62, 62, 62 is a gas branch, which is formed in the thick part of the lid 6. These gas branches 62.62.6
2 communicates with the gas passage 61 and opens into the flask 3. Therefore, the pressurized amine gas that has passed through the gas passage 61 is ejected into the flask 3 via this gas branch 62, 62, 62. Then, the ejected amine gas passes between the iron grains 5 and reaches the foundry sand 4.

On the other hand, in the plate stand 1, reference numeral 1.1 is a gas suction path, which is formed in the thick part thereof. Further, this gas suction path 11 is connected to gas branch paths 12, 12 . The flask 3 via...
It is open inward. This gas suction path 11 sucks gas in the flask 3, particularly amine gas in the flask 3, and assists in hardening of the molding sand 4. Note that this gas suction and the supply of the amine gas are performed simultaneously, and the amine gas is stopped before the amine gas is supplied.

After the molding sand 4 has hardened, the lid 6 and the plate stand 1 are removed to form the upper mold A in FIG. 2.

FIGS. 3 and 4 show the process of forming a lower die for casting. The lower molding device shown in FIG. 3 is substantially the same as the upper molding device, so a description thereof will be omitted.

After the molding sand 4 is hardened by the mold forming device shown in FIG.
The lower mold B is formed by removing the plate stand 1, and is placed in the state shown in FIG. 4 by inverting it.

In this case, the lid 6 remains fixed to the flask 3.

Then, as shown in FIG. 5, the upper mold A is placed on the lower mold B.
Place and fix. Reference numeral 7 denotes a tilting type pouring lid, which is placed and fixed on the upper mold A. This hot water pouring lid 7 has a hot water lower 1 communicating with a runner (of the upper mold). Reference numeral 72 denotes a hot water tray, which is removably installed on the hot water pouring lid 7. The molten metal M is once taken from the ladle in the horizontal state (rotated 90 degrees to the left from the state shown in the figure), and the molten metal M is poured into the cavity C while rotating to the right.

Reference numeral 6 denotes a lid used when forming the lower mold B, and as described above, it has a gas passage 61 and gas branch paths 62, 62.62.

While creating negative pressure in the flask 3 through this gas passage 61,
Molten metal M is injected into the cavity C through the injection hole 71.

Then, molding sand (forming the mold) is formed by the molten metal M.
The gas curing agent contained in 5 is overheated and combusted to generate a reaction gas, which passes through the gas passage 61 of the lid (when forming the lower mold) 6 and passes through the neutralization device. It is discharged to the outside of the flask 3 through the flask 3.

When the molten metal M in the cavity C solidifies, the suction of the reaction gas is stopped, the pouring lid 7 is removed, and the mold A,
By disintegrating B, a cast product can be obtained.

Further, in this embodiment, the lid body 6 or the plate stand 1 is commonly used in the molding of the upper mold and the lower mold, but it goes without saying that they may be provided separately. Further, a ventilation hole may be provided in the pouring lid.

Furthermore, although a breathable model was used as the model in this example, it does not necessarily have to be breathable.

In this case, there is no need for a ventilation passage at the bottom of the model.

〔Effect of the invention〕

The casting method according to the present invention includes a plate stand, a model, a flask, and a lid, the model and the flask are placed on the plate stand, and the flask is arranged so as to surround the model; In the mold forming apparatus, the surface of the model is covered with molding sand, the opening of the flask is sealed with the lid, a passage is provided in the lid, and the molding sand is filled with a hardening gas through the passage. After forming the mold, the mold is fixed to the flask and the lid is fixed to the flask for casting, so that the passage of the lid functions as a gas vent during casting. It is.

Therefore, if this casting method is used, there is no need to provide a separate degassing path in the casting apparatus, and as a result, the casting equipment becomes simple.

[Brief explanation of the drawing]

The drawings show an embodiment of the casting method according to the invention, Figures 1 and 2 are cross-sectional views showing the casting upper mold forming process; Figures 3 and 4 are cross-sectional views showing the process of forming the lower die for casting; FIG. 5 is a sectional view showing the casting process. 1... Plate stand 2...Model 3... Casting flask 6... Lid body 4... Foundry sand 61... Gas passage (passage) 62... Gas junction (passage) Figure 1 2nd Zu Figure 3 Figure 5

Claims (1)

[Claims] (1), comprising a plate stand, a model, a flask, and a lid, the model and the flask are placed on the plate stand, and the flask is arranged to surround the model; the surface of the model; in the mold forming apparatus, which covers the casting flask with molding sand, seals the opening of the flask with the lid, provides a passage in the lid, and fills the molding sand with a hardening gas through the passage, after forming the mold. . A casting method, characterized in that the mold is fixed to the flask, and the mold is subjected to casting with the lid fixed to the flask.