EP0073294B1 - Procédé de fabrication d'un moule carapace - Google Patents

Procédé de fabrication d'un moule carapace Download PDF

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Publication number
EP0073294B1
EP0073294B1 EP82104085A EP82104085A EP0073294B1 EP 0073294 B1 EP0073294 B1 EP 0073294B1 EP 82104085 A EP82104085 A EP 82104085A EP 82104085 A EP82104085 A EP 82104085A EP 0073294 B1 EP0073294 B1 EP 0073294B1
Authority
EP
European Patent Office
Prior art keywords
mold
molding material
manufacturing
set forth
shell
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP82104085A
Other languages
German (de)
English (en)
Other versions
EP0073294A3 (en
EP0073294A2 (fr
Inventor
Shigefumi Nagano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Pipe Fitting Mfg Co Ltd
Original Assignee
Nippon Kokan Pipe Fitting Mfg Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Kokan Pipe Fitting Mfg Co Ltd filed Critical Nippon Kokan Pipe Fitting Mfg Co Ltd
Publication of EP0073294A2 publication Critical patent/EP0073294A2/fr
Publication of EP0073294A3 publication Critical patent/EP0073294A3/en
Application granted granted Critical
Publication of EP0073294B1 publication Critical patent/EP0073294B1/fr
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C13/00—Moulding machines for making moulds or cores of particular shapes
    • B22C13/08—Moulding machines for making moulds or cores of particular shapes for shell moulds or shell cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/003—Pressing by means acting upon the material via flexible mould wall parts, e.g. by means of inflatable cores, isostatic presses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/006—Pressing by atmospheric pressure, as a result of vacuum generation or by gas or liquid pressure acting directly upon the material, e.g. jets of compressed air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B7/00—Moulds; Cores; Mandrels
    • B28B7/34—Moulds, cores, or mandrels of special material, e.g. destructible materials
    • B28B7/346—Manufacture of moulds

Definitions

  • the present invention relates to a method of manufacturing a shell mold as referred to in the preamble of claim 1.
  • a method of manufacturing a shell mold in which a preheated mold is charged with molding material, such as silica sand mixed with phenolic resin as a caking agent, the molding material is solidified along the forming surface of the mold, the mold is turned over to shake off the excessive molding material and then heated to solidify the shell-shape molding material sticked to the mold, thereby to form a shell, and the shell is finally taken out from the mold, whereby a shell mold is produced.
  • molding material such as silica sand mixed with phenolic resin as a caking agent
  • the expansion and/or contraction of the metal mold reduce the dimensional precision of a shell mold, and energy consumption is disadvantageously increased.
  • uneven thickness of the metal mold results in uneven heat capacity thereof, which easily causes the shell thickness to become uneven.
  • the molding material is limited to phenolic resin or the like, which can be heatingly solidified, with a narrow range of choice as to a caking agent.
  • the use of expensive molding material is unavoidable.
  • a method of manufacturing a shell mold of the type referred to in the preamble of claim 1 is known by AT ⁇ B ⁇ 338448, which describes a mold, having a predetermined forming surface, against which sheet material is pressingly held by negative pressure. As soon as the sheet material is firmly held at the forming surface a special flask is placed on top of it and covered by an additional cover sheet. A suction box surrounding the flask is used to hold the forming material and the sheet material in place. After the flask has been turned upside down the sheet material is dissolved and afterwards solidified to finish the shell mold.
  • This method is very complicated and expensive, since it needs two suction boxes and a large amount of forming material as well as a sheet material soluble in a solvent.
  • the forming material has to be solidified along the sheet material in a rather particular process.
  • the shell mold should be suitable for. a convenient use of a wooden, gypsum or resin mold, which are more economical than a metal mold and capable of being easily manufactured in a short period of time even if its shape is complicated, thus enabling to economically manufacture a shell mold in prompt response to an order received.
  • the method of the invention advantageously provides a shell mold in which a mold is not deformed, i.e., expanded and contracted around solidification of molding material due to heat, therefore precision of the shell mold is greatly improved. Thereby a shell mold can be formed which has a substantial uniform thickness without the occurrence of any peel-back.
  • a mold 1 horizontally held under a mold 1 is an elastic member in the sheet or film form, for example a vinyl sheet 2. Fire-resisting granular molding material 3 is suitably put on this vinyl sheet 2.
  • the mold 1 comprises a hollow suction box 4 having an air intake port 4a connected to a suction means such as a vacuum pump (not shown), a pattern plate 5 having a pattern 5a of predetermined shape and disposed below the suction box 4, and an outer frame 6 surrounding the circumference of the pattern plate 5.
  • the pattern plate 5 has therein a suitable number of suction holes 7 which open in the forming surface 5b of the pattern plate 5 and communicate with the inside of the suction box 4. As shown in Fig. 5, each of the suction holes 7 has a filter 8 made of a net member or the like to prevent the molding material from entering into the hole 7.
  • the outer frame 6 has in the entire lower periphery thereof a suction groove 9a and a suitable number of air holes 9b which open in the suction groove 9a and communicate with the inside of the suction box 4.
  • the vinyl sheet 2 has a circumference suitably larger than that of the outer frame 6 of the mold 1.
  • the molding material 3 is put on the vinyl sheet 2 at the center portion thereof such that the circumference of the molding material 3 put on the vinyl sheet 2 is suitably smaller than the inner circumference of the outer frame 6.
  • the molding material 3 put on the vinyl sheet 2 has a substantially uniform thickness.
  • the molding material 3 is constituted by silica sand to which 2 to 7% of sodium silicate is added as a caking agent. Such molding material 3 is adapted to be solidified by passing carbonic acid gas through the molding material 3 in an ambient temperature. As necessary, facing sand 3a may be put on the surface of the molding material 3 in order to obtain a good mold surface, as shown in Fig. 1
  • the mold 1 is lowered such that the lower end of the outer frame 6 of the mold 1 comes in contact with that peripheral portion 2a of the vinyl sheet 2 on which the molding material 3 is not put.
  • the pressure in the suction box 4 is reduced by operating the suction means (not shown) connected to the air intake port 4.
  • the peripheral portion 2a of the vinyl sheet 2 is held against the lower end of the outer frame 6 by a suction force acting on the suction groove 9a through the air holes 9b.
  • a negative pressure is then produced in the space surrounded by the vinyl sheet 2 and the mold 1, through the suction holes 7.
  • the molding material 3 is formed into a shell shape along the forming surface 5b of the mold 1. Namely, since a negative pressure is produced at the side of the molding material 3 on the vinyl sheet 2, the vinyl sheet 2 is extendingly pressed toward the forming surface 5b by the outside pressure.
  • the molding material 3 is then pressingly held and formed by the mold 1 and the vinyl sheet 2 as shown in Fig. 2. In this step, the molding material 3 is compressingly formed into a shell shape having a substantially uniform thickness along the forming surface 5b.
  • the mold 1 With the molding material 3 maintained as it is, the mold 1 is turned over as shown in Fig. 3. Carbonic acid gas then passes through the molding material 3 by a suitable means. At this time, a shock or vibration may be applied to the molding material 3 by a vibrator or the like (not shown) such that the molding material 3 is further uniformly or evenly distributed.
  • the shell is taken out from the mold 1 by a suitable means (not shown) and the vinyl sheet 2 is taken off from the shell, so that a desired shell mold 3' is obtained. It is to be noted that the vinyl sheet 2 may be taken off before carbonic acid gas passes through the molding material 3.
  • the molding material 3 is solidified as pressingly held and formed into a shell shape along the forming surface 5b, by the mold 1 and the vinyl sheet 2.
  • Such solidification is made according to the C0 2 process above-mentioned which requires no heating step. This eliminates the necessity of using an expensive metal mold difficult to manufacture, as the mold 1 and in particular the pattern 5a of complicated shape. That is, there may be used an economical wooden, gypsum or resin mold easy to manufacture.
  • the mold 1 may be economically manufactured in a short period of time, thus presenting an advantage that a prompt action can be taken when an order is received.
  • the mold 1 since it is not required to heat the mold 1, the mold 1 is not deformed, i.e., neither expanded nor contracted. Thus, precision of the shell mold 3' may be greatly improved.
  • the mold surface 3'a of the shell mold 3' may be made fine, thereby to improve the mold surface.
  • solidification of the molding material 3 may be made according to various methods to be applied in an ambient temperature, such as a cold box process.
  • an ambient temperature such as a cold box process.
  • sodium silicate there may be suitably used other inorganic or organic caking agents.
  • molding material formed by silica sand mixed with 2 to 7% of sodium silicate or 1 to 3% of a water solution of starch is pressingly held and formed into a shell shape in the same manner as above-mentioned.
  • the mold 1 may be heated within limits not thermally prejudiciary to the mold 1. Namely, the molding material 3 may be solidified by suitable means either in a cold atmosphere or a warm atmosphere, dependent on the characteristics of the mold 1. However, it is a matter of course that the foregoing does not prohibit the use of a metal mold.
  • the mold 1 With the molding material 3 pressingly held and formed into a shell by the mold 1 and the vinyl sheet 2, the mold 1 is turned over and the molding material 3 is solidified. Therefore, a dense shell having a uniform thickness may be formed and no peel-back takes place.
  • the molding material 3 is not required to be heated to a high temperature, but may be solidified in a cold or warm atmosphere. Therefore, gas is not generated, or even if generated, the amount is extremely small, and no operations in a high temperature are required, thus presenting an advantage in view of environmental sanitation. Even if gas should be generated, such gas may be quickly eliminated from the air intake port 4a of the suction box 4 through the suction holes 7.
  • vinyl sheet 2 is used as the elastic member in the embodiment discussed hereinbefore, an elastic sheet or film for example a rubber sheet may also be used.
  • the molding material 3 is not limited to silica sand mixed with sodium silicate or a water solution of starch to be solidified according to the C0 2 process or the like, but can be suitably selected dependent on a selected solidification process.
  • the number of the pattern plates is not limited to one as done in the embodiment shown in Fig. 1, but a plurality of pattern plates may be disposed. ' Thus, various kinds of shell molds can be conveniently manufactured at the same time.
  • the molding material 3 is solidified after the mold 1 has been turned over
  • the molding material may be solidified in the step shown in Fig. 2 before the mold 1 is turned over.
  • a shell removing agent may be suitably applied to the forming surface 5b of the mold 1.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Casting Devices For Molds (AREA)
  • Mold Materials And Core Materials (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Claims (20)

1. Procédé de fabrication d'un moule carapace comprenant les opérations consistant à approcher un moule (1) comportant une surface en forme prédéterminée (5b) d'une matière à mouler (3) avec un organe en forme de feuille ou de pellicule (2), à créer une pression négative dans un espace compris entre le moule (1) et l'organe (2) pour maintenir et mettre en forme par pression la matière à mouler (3) contre la surface en forme (5b), à solidifier la matière à mouler (3) par un procédé approprié et à la sortir du moule, caractérisé en ce que l'organe (2) en forme de feuille ou de pellicule est un organe élastique, que la matière à mouler (3) est déposée sur ledit organe élasque (2) de telle façon qu'elle ait une épaisseur appropriée, que le moule (1) est approché de la matière à mouler (3) par le haut, que la partie périphérique (2a) de l'organe élastique (2) est maintenue contre le moule (1) par ladite pression négative, et que la totalité de la matière à mouler (3) et de l'organe élastique (2) sont déformés pour leur donner la forme d'une carapace (3') épousant la forme de la surface en forme (5b).
2. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que la matière à mouler (3) est solidifiée dans une atmosphère froide ou chaude par le procédé au C02 ou le procédé à boîte froide.
3. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que la matière à mouler (3) est du sable siliceux mélangé à une petite quantité de silicate de soude servant d'agent agglomérant et que ladite matière à mouler est solidifiée en y faisant passer du gaz carbonique.
4. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que la matière à mouler (3) est du sable siliceux mélangé à une petite quantité de silicate de soude servant d'agent agglomérant et qu'après avoir été mise sous la forme d'une carapace (3') par application d'une pression, ladite matière à mouler est solidifiée en y faisant passer de l'air chaud.
5. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que la matière à mouler (3) utilisée est du sable siliceux mélangé à une petite quantité d'une solution aqueuse d'amidon servant d'agent agglomérant et qu'après avoir été mise sous la forme d'une carapace (3') par application d'une pression, ladite matière à mouler est solidifiée en y faisant passer de l'air chaud.
6. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que du sable pour couche de contact (3a) est déposé sur la surface de la matière à mouler (3) déposée elle-même sur l'organe élastique (2), ladite couche de sable de contact ayant une épaisseur pratiquement uniforme.
7. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que le moule (1) comprend une boîte à dépression (4) munie d'un raccord d'aspiration (4a) raccordé à un moyen d'aspiration tel qu'une pompe à vide, une plaque modèle (5a) de forme prédéterminée et disposée sous ladite boîte à dépression et un cadre extérieur (6) entourant la périphérie de ladite plaque modèle sous la boîte à dépression.
8. Procédé de fabrication d'un moule carapace selon la revendication 7, caractérisé en ce que le moule (1) et la plaque modèle (5) comportent un certain nombre de trous d'aspiration (7) qui débouchent dans la surface en forme (5a) à une extrémité et dans la boîte à dépression (4) à l'autre extrémité.
9. Procédé de fabrication d'un moule carapace selon la revendication 8, caractérisé en ce que chacun des trous d'aspiration (7) de la plaque modèle (5) montée dans le moule (1) est muni d'un filtre (8) pour empêcher la matière à mouler (3) de pénétrer dans ce trou.
10. Procédé de fabrication d'un moule carapace selon la revendication 9, caractérisé en ce que le cadre extérieur (6) du moule (1) comporte une gorge d'aspiration (9a) à sa partie périphérique inférieure et un certain nombre de trous de passage d'air (9b) qui débouchent dans ladite gorge à une extrémité et dans la boîte à dépression (4) à l'autre extrémité.
11. Procédé de fabrication d'un moule carapace selon la revendication 7, caractérisé en ce que le moule (1) porte un certain nombre de plaques modèle (5).
12. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que l'organe élastique (2) est une feuille de vinyle.
13. Procédé de fabrication d'un moule carapace selon la revendication 10 ou 12, caractérisé en ce que l'organe élastique (2) a une périphérie (2a) plus grande que celle du cadre extérieur (6) du moule (1).
14. Procédé de fabrication d'un moule carapace selon la revendication 13, caractérisé en ce que la matière à mouler (3) est déposée sur l'organe élastique (2), au centre de celui-ci, dans une zone plus petite que la périphérie intérieure du cadre extérieur (6) du moule (1), ladite matière à mouler formant une couche d'épaisseur pratiquement uniforme.
15. Procédé de fabrication d'un moule carapace selon la revendication 14, caractérisé en ce que l'organe élastique (2) est maintenu horizontal ou presque horizontal.
16. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que le moule (1) est retourné avant que la matière à mouler (3) soit solidifiée.
17. Procédé de fabrication d'un moule carapace selon la revendication 16, caractérisé en ce que des chocs ou des vibrations sont appliqués à la matière à mouler (3) avant qu'elle soit solidifiée.
18. Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce que l'organe élastique (2) est enlevé après que la matière à mouler (3) ait été solidifiée.
19. Procédé de fabrication d'un moule carapace selon la revendication 2, caractérisé en ce que le moule (1) est un moule en bois, en plâtre ou en résine ou un autre moule non métallique.
20 Procédé de fabrication d'un moule carapace selon la revendication 1, caractérisé en ce qu'un agent de démoulage approprié est appliqué sur la surface en forme (5b) du moule (1).
EP82104085A 1981-08-25 1982-05-11 Procédé de fabrication d'un moule carapace Expired EP0073294B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP133096/81 1981-08-25
JP13309681A JPS5835041A (ja) 1981-08-25 1981-08-25 シエル鋳型の製造方法

Publications (3)

Publication Number Publication Date
EP0073294A2 EP0073294A2 (fr) 1983-03-09
EP0073294A3 EP0073294A3 (en) 1983-07-27
EP0073294B1 true EP0073294B1 (fr) 1986-08-13

Family

ID=15096735

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82104085A Expired EP0073294B1 (fr) 1981-08-25 1982-05-11 Procédé de fabrication d'un moule carapace

Country Status (3)

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EP (1) EP0073294B1 (fr)
JP (1) JPS5835041A (fr)
DE (1) DE3272547D1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2566687B1 (fr) * 1984-06-27 1986-08-22 Air Liquide Dispositif de fabrication de moules ou de noyaux de moulage congeles
CN101837429B (zh) * 2010-05-31 2012-07-04 齐齐哈尔轨道交通装备有限责任公司 二氧化碳硬化水玻璃砂铁模射砂造型方法
JP2016131996A (ja) * 2015-01-19 2016-07-25 ヨシワ工業株式会社 鋳型

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD93227A (fr) *
JPS5035484B1 (fr) * 1971-06-25 1975-11-17
DE2352492B2 (de) * 1973-10-19 1977-08-25 Wittmoser, Adalbert, Prof Dr-Ing, 6840 Lampertheim Verfahren zur herstellung von durch unterdruck stabilisierten, hohlen giessformen
JPS5093821A (fr) * 1973-12-25 1975-07-26
DE2407878C2 (de) * 1974-02-19 1975-12-18 Heinrich Wagner, Maschinenfabrik, 5928 Laasphe Kastenlose Gießform
JPS5160629A (en) * 1974-11-22 1976-05-26 Mitsubishi Heavy Ind Ltd Genatsuzokeiigatano seisakuhoho
GB1533481A (en) * 1975-02-18 1978-11-29 Asahi Glass Co Ltd Method and apparatus for moulding cementitious material
DE2508276A1 (de) * 1975-02-26 1976-09-02 Buderus Eisenwerk Giessform und verfahren zu ihrer herstellung
JPS5289522A (en) * 1976-01-23 1977-07-27 Mitsubishi Heavy Ind Ltd Mold manufacturing method
DE2833999C2 (de) * 1978-08-03 1981-11-19 Eugen Dipl.-Ing. 8871 Burtenbach Bühler Verfahren und Vorrichtung zur Herstellung von Gießformen und -kernen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GIEBEREI-LEXIKON, 1978, FACHVERLAG SCHIELE & SCHÖN, Markgrafenstrasse 11, D-100 Berlin 61, pages 818-821 *

Also Published As

Publication number Publication date
JPH0153143B2 (fr) 1989-11-13
JPS5835041A (ja) 1983-03-01
DE3272547D1 (en) 1986-09-18
EP0073294A3 (en) 1983-07-27
EP0073294A2 (fr) 1983-03-09

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