JPH04270027A - Molding flask - Google Patents

Abstract

PURPOSE:To quickly discharge gas produced with the combustion of a consumable pattern from a mold to an external part. CONSTITUTION:A box type space chamber 4 is provided on the lower part of a box type molding flask 1 opened at the upper part and formed so that a pair of the faced side walls 5 is opened. A gas venting body 6 communicated with the space chamber 4 is erected at the bottom face of a molding flask main body 1. The gas produced with the combustion of the consumable pattern 3 is discharged to the external part from the upper opening part in the molding flask body 1 and also discharged to the external part from the space chamber 4 through the gas venting body 6.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a casting flask used in an investment casting method.

0002

[Prior Art] A casting flask used in the disappearing model casting method has a box-shaped flask body with a number of ventilation holes on the bottom and a wire mesh, and a box body forming a decompression chamber around the outer periphery of the flask. It is set up. The flask body is filled with dry sand that does not contain a binder, and a mold is made by embedding a disappearing model made of foamed resin in the dry sand (for example,
2-5004, Figure 2).

0003

[Problem to be Solved by the Invention] Conventional molds generate a large amount of gas when the disappearing model disappears with the molten metal, so the gas is discharged to the outside through the vent hole in the flask body and through a decompression chamber. However, since the mold uses dry sand that does not contain a binder, the light sand may be engulfed by the gas during degassing and come out of the mold body through the ventilation hole, or when the dry sand is added or when it vibrates. During molding, it spills out of the ventilation holes and accumulates in the vacuum chamber. Therefore, there is a problem that degassing from the decompression chamber becomes worse. Therefore, the present invention has been made to solve this problem, and provides a flask with good degassing.

0004

[Means for Solving the Problems] The flask of the present invention is provided with a void chamber having an opening at the bottom of the flask body, and a gas vent communicating with the void chamber is provided upright on the bottom surface of the flask body. be.

[0005]

[Operation] During pouring, the gas generated within the flask body due to the combustion of the disappearing model moves through the dry sand, passes through the gas vent, is vented into the void chamber, and is then discharged to the outside through the opening of the void chamber. Ru.

[0006]

[Embodiment] Fig. 1 shows an embodiment of the flask according to the present invention, in which a box-shaped flask body 1 with an open top is filled with dry sand 2 containing no binder. A disappearing model 3 made of foamed resin is buried in the area. A box-shaped void chamber 4 is provided in the lower part of the flask body 1, and a pair of opposing side walls 5 are formed to be open. A suitable number of gas vents 6 are erected on the bottom surface of the flask body 1, and the gas vents 6 are formed from a bottomed cylindrical body 6b having a circular tube 6a, and a slit width of 0.5 mm is formed on the top surface of the cylindrical body 6b. A slit vent (not shown) of 1 to 0.2 mm is provided, and the surface of the cylindrical body 6b is formed from a cylindrical mesh of 200 to 400 mesh, and the flask body 1, the bottomed cylindrical body 6b, the cylinder 6a, and the void chamber. 4 are formed so as to communicate with each other. A slit vent (not shown) with a slit width of 0.1 to 0.2 mm and a cylindrical mesh of 200 to 400 mesh do not cause sand spillage and have a good degassing effect.

[0007] Next, an extinguishable model casting method using the flask will be explained. Disappearance model 3 is created by pouring molten metal into the interior of vanishing model 3.
The casting 7 is cast by replacing the molten metal with the molten metal. During this pouring, the gas generated by the combustion of the vanishing model 3 is the dry sand 2
The air moves within the flask body 1 and is discharged to the outside from the upper opening of the flask body 1, and is also vented to the void chamber 4 via the gas vent 6, and then discharged to the outside from the opening of the void chamber 4. This flask prevents the dry sand 2 from leaking from the flask body 1 to the gas evacuator 6 when venting the gas, and also prevents the dry sand 2 from leaking from the flask body 1 to the venting gas 6 during sand injection or molding.
There is no possibility that the gas will leak from the flask body 1 to the venting gas 6.

[0008]

According to the present invention, a void chamber having an opening is provided at the bottom of the flask body, and a gas vent communicating with the void chamber is provided upright on the bottom of the flask body, so that gas can be vented. Since it is carried out quickly and there is no sand leakage, there are no gas defects and it is possible to easily obtain high-precision castings, which greatly contributes to improved productivity.

[Brief explanation of the drawing]

[Fig. 1] Cross-sectional view of a mold using a flask according to the present invention

[Explanation of symbols]

1 Casting flask body 4 Vacancy chamber 6. Gas removal

Claims (1)

[Claims] Claim 1: In a flask with an open top used in the vanishing model casting method, a cavity chamber having an opening is provided at the bottom of the flask body, and a gas vent communicating with the cavity chamber is provided on the bottom of the flask body. A casting flask characterized by the following: