Green sand mold and its production method, and production method of iron-based casting

Patent metadata

Field	Value
Publication number	US-10946435-B2
Application number	US-201415023845-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Sep 30, 2013
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A green sand mold comprising at least one pair of green sand mold parts each comprising a recess and a mating surface, wherein a cured layer comprising a thermosetting resin as a main component is formed on the recess and mating surface of each green sand mold part, and wherein the cured layer has hardness of 40-98, a thickness of 0.5-6 mm, and gas permeability of 70-150, is produced by applying a curing material comprising the thermosetting resin as a main component and having viscosity of 1-100 mPa·S to the recess and mating surface of each green sand mold part, combining the green sand mold parts, and then heat-hardening the curing material.

First claim

What is claimed is:

1. A method for producing a green sand mold comprising at least one pair of green sand mold parts each comprising a recess and a mating surface, a cured layer comprising a heat hardened thermosetting resin as a main component being formed on the whole of the recess and mating surface of each of the green sand mold parts; and said cured layer having hardness of 40-98 measured by a self-hardening hardness meter NK-009, available from Nakayama Co., Ltd., a thickness of 0.5-6 mm, and gas permeability measured by a rapid method described in Annex 3 of JIS Z 2601 of 70-150, comprising the steps of
applying a curing material consisting of a thermosetting resin and alcohol and having viscosity of 1-100 mPa·S to a recess and a mating surface of each of the green sand mold parts;
combining the green sand mold parts; and then
heat-hardening the curing material at a temperature of 80-180° C.

2. The method for producing the green sand mold according to claim 1 , wherein the amount of the curing material applied is 100-550 g/m 2 .

3. The method for producing the green sand mold according to claim 1 , comprising the steps of
applying a curing material having viscosity of 1-15 mPa·S to a recess and a mating surface of each of the green sand mold parts;
semi-hardening the curing material penetrated into the green sand mold parts;
combining the green sand mold parts; and then
heating the semi-cured layer to form a substantially completely cured layer.

4. The method for producing the green sand mold according to claim 3 , wherein the hardness of the semi-cured layer measured by a self-hardening hardness meter is 30-45.

5. The method for producing the green sand mold according to claim 3 , wherein the thickness of the cured layer is 2.2-6 mm.

6. The method for producing the green sand mold according to claim 3 , wherein said semi-hardening of the curing material is conducted by heating using an incandescent lamp and said heating of the semi-cured layer is conducted by heating using hot air.

7. The method for producing the green sand mold according to claim 3 , wherein said curing material has viscosity of 1-10 mPa·S.

8. The method for producing the green sand mold according to claim 1 , comprising the steps of
applying a curing material having viscosity of 15-100 mPa·S to a recess and a mating surface of each of the green sand mold parts;
combining the green sand mold parts; and then
heat-hardening the curing material to form a substantially completely cured layer.

9. The method for producing a green sand mold according to claim 8 , wherein a curing material layer before the green sand mold parts are combined has hardness measured by a self-hardening hardness meter of 5-30.

10. The method for producing the green sand mold according to claim 8 , wherein the cured layer has a thickness of 0.5-2.2 mm.

Assignees

• Hitachi Metals Ltd

Inventors

• Fukumoto Kentaro

Classifications

• B22C9/02 Primary

  Sand moulds or like moulds for shaped castings · CPC title

• B22C3/00

  Selection of compositions for coating the surfaces of moulds, cores, or patterns · CPC title

• B22D15/00

  Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor · CPC title

• B22C1/22 Primary

  of resins or rosins · CPC title

• B22C9/12

  Treating moulds or cores, e.g. drying, hardening · CPC title