JPS62130741A - Forming method for casting mold - Google Patents

Abstract

PURPOSE:To prevent defective molding arising from the defective packing of nonbinding sand and to obtain a defectless casting by adopting a molding method consisting in packing binding sand into the recess of a consumable pattern and solidifying the sand. CONSTITUTION:The binding sand 6 is preliminarily packed into the recess of the consumable pattern 5 having much ruggedness and is solidified to form the entire part of the pattern 5 to the shape to obviate the generation of defective molding (the state having no ruggedness and cavities) prior to molding of the pattern 5 with a vibrating molding machine (not shown). After a molding flask 7 is installed on the molding machine, a sprue clay pipe 2 is inserted to the pattern 5 and while the nonbinding sand 1 is thrown into the pattern, the sand is oscillated by prescribed excitation force, by which the molding is completed. Silica sand is generally used for the sand 1 and the above- mentioned sand 1 compounded with a binder such as furan resin or phenolic resin, curing agent, etc., is used for the sand 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] Unexploded EA relates to a mold making method in which a vibration molding machine is used to cast a disappearing model.

[Conventional technology]

The vanishing model casting method has features such as no need for a core, no casting burrs, and lower casting costs than when using conventional wooden models. In particular, in the vanishing model casting method, in order to further reduce costs, the conventionally used caking sand such as 7 run sand requires expensive equipment such as kneading equipment during molding and sand processing equipment after casting. , the use of caking sand is ``Donuichi'' A vacuum casting method using non-caking sand that does not contain binders or hardeners is being put into practical use. After installing the frame, place the vanishing model in the flask, apply vibration while adding non-caking sand, and mold the mold.
This is a method of casting by keeping this mold under reduced pressure. Note that this casting method also includes a method in which the material is cast in a mold using a vibration molding machine without reducing the pressure.

[Problem that the invention seeks to solve]

In the conventional casting method described above, when molding is performed using an imaging molding machine, the shape of the disappearing model may be affected by filling defects, especially in areas with recesses, resulting in poor shape, insertion of molten metal, joints, etc. The disadvantage was that it was not possible to produce a cast iron.

An object of the present invention is to provide a mold manufacturing method that does not cause molding defects (filling defects) regarding the disappearing model.

[Friendly means of solving problems]

The present invention is a mold making method using a vanishing model, in which the concavities of the model are filled with caking sand in advance and solidified, and then non-caking sand is poured into the surrounding area, and the non-caking sand is filled with a vibration molding machine. This article relates to a mold making method that focuses on filling.

That is, the present invention is particularly useful when molding a foundry model (i.e., vanishing model J) made of polystyrene resin foam, polyolefin thread resin, etc. with non-caking sand, especially when the vanishing model has severely uneven parts. In this case, the recesses are filled with caking sand in advance, and after solidification, vibration modeling is performed using non-caking sand to prevent filling defects.

Hereinafter, the present invention will be explained based on the drawings. FIG. 1 shows an embodiment for explaining the mold making method of the present invention.

j Before molding the vanishing model 5 with severe irregularities using a vibration molding machine (J, not shown), the concave portions of the model 5 are filled with caking sand (sand mixed with a caking agent) 6 and solidified to form the vanishing model. The whole 5 is shaped to avoid molding defects (no unevenness, no wall side).In addition, as a countermeasure for degassing the caking sand 6, it may be molded at the same time as the Saran cord 8.After that, the vibrating molding machine After installing the crusher 7 on top, attach the sprue porcelain pipe 2 to the model 5 above.
is inserted, and the mold is vibrated with a predetermined excitation force while adding non-caking sand 1 to complete mold making.

As the non-caking sand 1 used in the present invention, crushed sand is generally used, and sometimes special sands such as zircon sand, oripin sand, and chromite sand are also used.

Further, as the caking sand to be filled and solidified in advance in the recesses of the vanishing model 5, the above-mentioned non-caking sand mixed with the caking agent shown in the table below is used.

Note (1) Xylene sulfonic acid or para-toluene sulfonic acid (2) Linocure mold (3) Incure mold In Fig. 1, 5 is the runner and 4 is the weir.

〔Effect of the invention〕

According to the present invention, when casting is performed using a mold made by employing a mold making method in which the recesses of the vanishing pattern are filled with caking sand and solidified, a 100% sound casting can be produced.

〔Example〕

The present invention will be described in detail with reference to FIG.

Polystyrene resin foam (density (LO18t/an”
) using a vanishing model 5 with uneven parts [model dimensions:
200W x 200H Product name P-6) (L4wt
Ch/Refined fat, foundry sand = (Freemantle crushed sand, particle size AF8
: b 5) ) was filled and solidified. In addition, in consideration of degassing the flan sand, Saran string 8 (reticular mesh string made of synthetic fiber) was also molded at the same time.On the surface of the casing and model 50,
A highly breathable zircon-based coating mold (trade name: Sairyoku Super 510, manufactured by Okazaki Mining Products) was applied with a brush.

On the vibration molding machine (-J, not shown), cast flask 7 [Dimensions: 50QW
After installing the molding machine (X500H
0ky, the output α was 15kWJ, and the mold making was completed. After that, the upper surface of the mold was covered with a vinyl sheet, the pressure was reduced with a water ring pump (decompression knee 1004 Hf), and the mold was filled with molten cast iron (257% carbon, 2.8% silicon, 2.8% manganese).
15% Magnesium: (L 045%) 1590
-Cast with C. Conventionally, when vibration molding was performed using only non-caking sand, the casting yield was around 98.0%, but by adopting the present invention, the yield was 100%, making it possible to produce sound castings. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.
A) is a side view, and A) in Fig. 1 is a plane view.

Claims (1)

[Claims] In the mold making method using an erasing model, the recesses of the model are filled with caking sand in advance and solidified, then non-caking sand is poured into the surrounding area, and the non-caking sand is filled with a vibration molding machine. Characteristic mold making method.