JPS63242439A - Production of mold for investment casting - Google Patents
Production of mold for investment castingInfo
- Publication number
- JPS63242439A JPS63242439A JP62076293A JP7629387A JPS63242439A JP S63242439 A JPS63242439 A JP S63242439A JP 62076293 A JP62076293 A JP 62076293A JP 7629387 A JP7629387 A JP 7629387A JP S63242439 A JPS63242439 A JP S63242439A
- Authority
- JP
- Japan
- Prior art keywords
- core
- mold
- slurry
- binder
- coating layer
- 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.)
- Granted
Links
- 238000005495 investment casting Methods 0.000 title claims abstract description 11
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- 239000011230 binding agent Substances 0.000 claims abstract description 41
- 239000011247 coating layer Substances 0.000 claims abstract description 28
- 239000000463 material Substances 0.000 claims abstract description 27
- 239000010410 layer Substances 0.000 claims abstract description 23
- 239000002002 slurry Substances 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 12
- 238000001035 drying Methods 0.000 claims abstract description 9
- 238000011049 filling Methods 0.000 claims abstract description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 42
- 238000000034 method Methods 0.000 claims description 22
- 239000004576 sand Substances 0.000 claims description 19
- 239000000377 silicon dioxide Substances 0.000 claims description 9
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 9
- 239000004115 Sodium Silicate Substances 0.000 claims description 8
- 238000010304 firing Methods 0.000 claims description 8
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 8
- 239000011248 coating agent Substances 0.000 claims description 5
- 238000000576 coating method Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 238000007581 slurry coating method Methods 0.000 claims description 5
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 4
- 239000008119 colloidal silica Substances 0.000 claims description 3
- 235000019795 sodium metasilicate Nutrition 0.000 claims description 3
- 239000008187 granular material Substances 0.000 claims 1
- 238000005266 casting Methods 0.000 abstract description 4
- 239000000919 ceramic Substances 0.000 abstract description 3
- 239000001993 wax Substances 0.000 description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004898 kneading Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910052845 zircon Inorganic materials 0.000 description 3
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 235000013312 flour Nutrition 0.000 description 2
- 239000005350 fused silica glass Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000012188 paraffin wax Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229920006328 Styrofoam Polymers 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 239000008261 styrofoam Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、中子を用いたインベストメント鋳造用鋳型の
製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an investment casting mold using a core.
（発明の背景）
インベストメント鋳造に用いるセラミック中子は表面の
十分な平滑さと、ろう模型の射出成形に耐えるに充分な
強度と、焼成あるいは注湯時に酎えうる高い熱間強度と
を備えることが求められる。そこで従来は骨材にアルミ
ナ、ジルコン、溶融シリカ等を用いて中子を成形し、こ
の中子を単独で焼成、焼結していた。このため中子の生
産性が悪く寸法精度も悪くなり、特に大型のものでは希
望の精度を出すのが非常に困難で高価でもあった。(Background of the Invention) Ceramic cores used for investment casting must have a sufficiently smooth surface, sufficient strength to withstand injection molding of wax models, and high hot strength that can be obtained during firing or pouring. Desired. Therefore, in the past, a core was formed using alumina, zircon, fused silica, etc. as aggregate, and this core was fired and sintered alone. For this reason, the productivity of the core was poor and the dimensional accuracy was poor, and it was extremely difficult and expensive to achieve the desired precision, especially for large cores.
また特に焼結による中子は崩壊性が悪く、物理的な振動
や衝撃で中子を除去するのは不可能であり、中子の除去
工程が面倒で能率の悪いものになっていた。Furthermore, the sintered core has particularly poor collapsibility, making it impossible to remove the core by physical vibration or impact, making the core removal process troublesome and inefficient.
さらにこのように焼結を必要とする中子では、焼結が困
難な骨材例えば安価なけい砂等は使用できなかった。Furthermore, in cores that require sintering, aggregates that are difficult to sinter, such as inexpensive silica sand, cannot be used.
（発明の目的）
本発明はこのような事情に鑑みなされたものであり、中
子を用いる場合に鋳造製品の中子側の鋳肌を十分滑らか
にし寸法精度を高めることができ、ろう模型の射出成形
時に充分耐え得る低温強度と共に高い熱間強度を有し、
中子単独での焼成が不要で生産性が高く安価でもあり、
物理的手段による崩壊性が良好で中子の除去が容易であ
り、さらに安価なけい砂等の骨材も使用可能となるイン
ベストメント鋳造用鋳型の製造方法を提供することを目
的とする。(Object of the Invention) The present invention was made in view of the above circumstances, and it is possible to sufficiently smooth the casting surface on the core side of a cast product when using a core, improve dimensional accuracy, and improve the dimensional accuracy of a wax model. It has high hot strength as well as low temperature strength that can withstand injection molding,
There is no need to fire the core alone, making it highly productive and inexpensive.
It is an object of the present invention to provide a method for manufacturing a mold for investment casting, which has good disintegrability by physical means, allows easy removal of the core, and allows the use of inexpensive aggregates such as silica sand.
（発明の構成）
本願第１発明によればこの目的は、以下の工程からなる
ことを特徴とするインベストメント鋳造用鋳型の製造方
法：
（ａ）中子型にスラリを流入して中子型内面にスラリの
コーティング層を形成し余分のスラリを排出する工程；
（ｂ）骨材とバインダとの混練物を前記中子型内に充填
する工程；
（ｃ）中子型の外側からマイクロ波誘電加熱によりスラ
リコーティング層と混練物とを加熱乾燥し硬化する工程
；
（ｄ）中子型から中子を取出す工程；
（ｅ）この中子を型内に位置決めしてこの型内に消失模
型材を注入し、中子を鋳ぐるんだ消失模型を形成する工
程；
Ｄ）この消失模型にスラリおよびスタッコ粒を交互に複
数回塗布して耐火物層を形成し乾燥する工程；
（ｇ）消失模型を消失させて鋳型を形成する工程；（ｈ
）中子と耐火物層とを同時に焼成する工程；により達成
される。(Structure of the Invention) According to the first invention of the present application, this object is achieved by a method for manufacturing an investment casting mold, which is characterized by comprising the following steps: (a) Injecting slurry into a core mold to form an inner surface of the core mold. (b) Filling the core mold with a mixture of aggregate and binder; (c) Applying microwave dielectric from the outside of the core mold. A step of drying and curing the slurry coating layer and the kneaded material by heating; (d) A step of taking out the core from the core mold; (e) Positioning the core in the mold and dissolving the model material into the mold. (d) Step of applying slurry and stucco particles alternately to this vanishing model multiple times to form a refractory layer and drying; (g) Vanishing Step of eliminating the model and forming a mold; (h
) Simultaneously firing the core and the refractory layer;
また本願第２発明によればこの同一の目的は、前記第１
発明に、中子型から取出した中子に高温強度の高い高温
用バインダを含浸させた後中子を乾燥する行程を付加す
ることにより達成される。Further, according to the second invention of the present application, this same purpose is achieved by the first invention.
This is achieved by adding to the invention a step of impregnating the core taken out from the core mold with a high-temperature binder having high high-temperature strength and then drying the core.
ここにこの第２発明においては、行程（ｂ）における混
練物としてメタ珪酸ソーダ等の粉末状無機バインダを骨
材にコーティングしてなる乾燥しかつ流動性に優れたコ
ーテツドサンドを用いることができる。Here, in this second invention, dry coated sand with excellent fluidity, which is obtained by coating aggregate with a powdered inorganic binder such as sodium metasilicate, can be used as the kneaded material in step (b). .
（実施例）
第１図は本願第１発明の一実施例の工程流れ図、第２図
はその各工程の説明図である。(Example) FIG. 1 is a process flowchart of an embodiment of the first invention of the present application, and FIG. 2 is an explanatory diagram of each process.
まず誘電加熱しにくい材料で作った中子型１０を用意し
、この型内にスラリ（塗型液）を注入する（第１図、ス
テップＺｏｏ）。このスラリは
エチルシリケート ５０重量％ジルコンフ
ラワー３５０番 ５０重量％などを用いたバインダと
フィシを含有するものが望ましい。スラリを中子型１０
内に注入した後適宜時間経過後に中子型１０を上下逆転
して内部のスラリを排出する（ステップ１０２）、’こ
の結果中子型１０の内面には適宜厚さのスラリのコーテ
ィング層１２が形成される（第２図Ａ）。First, a core mold 10 made of a material that is difficult to dielectrically heat is prepared, and slurry (coating liquid) is poured into this mold (FIG. 1, step Zoo). This slurry preferably contains a binder using 50% by weight of ethyl silicate and 50% by weight of zircon flour No. 350, and the like. Put the slurry into core mold 10
After an appropriate amount of time has elapsed, the core mold 10 is turned upside down and the slurry inside is discharged (step 102).As a result, a coating layer 12 of slurry of an appropriate thickness is formed on the inner surface of the core mold 10. formed (Fig. 2A).
一方中子の主原料として、骨材と、低温粘結力の大きい
無機バインダと、高温強度の高い高温用バインダとを混
練しておく（ステップ１０４）。On the other hand, as main raw materials for the core, aggregate, an inorganic binder with high low-temperature caking strength, and a high-temperature binder with high high-temperature strength are kneaded (step 104).
骨材としては例えば、
けい砂 ９０重量％
シリカフラワー １０重量％
を混合して用いる。ここにけい砂はＪＩＳ規格Ｇ５９０
１ （１９５４）の規定による７号程度の粒度のものが
望ましい。As the aggregate, for example, a mixture of 90% by weight of silica sand and 10% by weight of silica flour is used. The silica sand here is JIS standard G590.
1 (1954) with a particle size of approximately No. 7 is preferable.
無機バインダとしては珪酸ソーダ（水ガラス）の３号程
度のものを用い、これは中子の低温時の強度を確保し中
子を速やかに硬化させる作用を持つものである。高温用
バインダとしてはエチルシリケートやコロイダルシリカ
が用いられる。この高温用バインダは中子の高温時の強
度を確保する作用を持つものである。一般に無機バイン
ダとしての珪酸ソーダは２００℃を超えると粘結力が急
激に低下するが、高温用バインダはこの無機バインダの
粘結力の低下を補って高温時の強度を向上させるもので
ある。As the inorganic binder, approximately No. 3 sodium silicate (water glass) is used, which has the effect of ensuring the strength of the core at low temperatures and quickly hardening the core. Ethyl silicate and colloidal silica are used as the high temperature binder. This high-temperature binder has the effect of ensuring the strength of the core at high temperatures. Generally, the cohesive strength of sodium silicate as an inorganic binder rapidly decreases when the temperature exceeds 200°C, but a high-temperature binder compensates for this decrease in the cohesive strength of the inorganic binder and improves the strength at high temperatures.
これら無機バインダと高温用バインダとは例えば５０重
量％づつ程度の割合で予め混合され、この混合液を骨材
に少量づつ加えながら混練する。The inorganic binder and the high-temperature binder are mixed in advance at a ratio of about 50% by weight, for example, and the mixed solution is added to the aggregate little by little while kneading.
この混合液は全体重量の８％程度まで混入できるが、４
％位とするのが望ましい。高温用バインダの混合量は中
子の寸法、重量が大きくなるにつれて増大させて、高温
時の中子の強度増加を図るべきであるが、中子の崩壊性
を考慮してできるだけ少ない混合量とするのが望ましい
。This mixed liquid can be mixed up to about 8% of the total weight, but
It is desirable to set it to %. The amount of high-temperature binder mixed should be increased as the size and weight of the core increases to increase the strength of the core at high temperatures, but the amount mixed should be as small as possible considering the disintegration of the core. It is desirable to do so.
なおこの混練は、室温２０℃、湿度５５％の雰囲気中で
２０分程度行うが、混練後は直ちに密封する。これは珪
酸ソーダが大気中の炭酸ガスによって硬化する性質を持
つため、これにより混練物が硬化するのを防ぐためであ
る。このように混練した原料（混練物）はスラリのコー
ティング層１２を形成した中子型１０内に充填される（
ステップ１０４、第２図Ｂ）。This kneading is carried out for about 20 minutes in an atmosphere with a room temperature of 20° C. and a humidity of 55%, but the container is sealed immediately after kneading. This is to prevent the kneaded material from hardening because sodium silicate has the property of being hardened by carbon dioxide gas in the atmosphere. The raw materials (kneaded material) kneaded in this way are filled into the core mold 10 on which the slurry coating layer 12 is formed (
Step 104, FIG. 2B).
このように混練物１４を充填した状態の中子型は第２図
（ｃ）に示すように電極１６ａ、１６ｂ間に置かれ、こ
れら電極１６に交流電源１８により高周波交流電圧が印
加される。すなわち誘電加熱が行われる（ステップ１０
６）。この誘電加熱により中子型１０内の層１２と充填
された混練物１４とが共に加熱され、これらに含まれる
水分が水蒸気となって中子型１０外へ出てゆく。この高
温の水蒸気が混練物１４を通る時に、けい砂などの骨材
の表面をコーティングする珪酸ソーダを溶解し、乾燥硬
化させる。この結果混練物１４とコーティング層１２と
は一体化して硬化し、十分な低温強度が得られる。The core mold filled with the kneaded material 14 in this manner is placed between the electrodes 16a and 16b as shown in FIG. 2(c), and a high frequency AC voltage is applied to these electrodes 16 by the AC power source 18. That is, dielectric heating is performed (step 10
6). By this dielectric heating, the layer 12 in the core mold 10 and the filled kneaded material 14 are heated together, and the water contained therein turns into water vapor and flows out of the core mold 10. When this high-temperature steam passes through the kneaded material 14, it dissolves the sodium silicate that coats the surface of the aggregate such as silica sand, and causes it to dry and harden. As a result, the kneaded material 14 and the coating layer 12 are integrated and cured, and sufficient low-temperature strength is obtained.
このように誘電加熱した後中子型ｌＯを分割して型ばら
しすれば（ステップ１０８）、表面にスラリのコーティ
ング層１２を有する中子２０が得られる。If the core mold 1O is divided and demolded after dielectric heating in this manner (step 108), a core 20 having a slurry coating layer 12 on its surface is obtained.
次にこのようにして得た中子２０にパラフィンワックス
を塗布する（ステップ１１０、第２図Ｄ）。この塗布は
８０〜９０’Ｃで溶融したパラフィンワックス中にコー
ティング層１２付きの中子２０を１０分程度浸漬するこ
とにより行う。この結果コーティング層１２の表面にワ
ックス層２２が形成され、コーティング層１２の砂落ち
が防止される。また中子２０の強度を増大させ中子の移
送中における破損を防止すると共に、中子保存中に中子
が吸湿するのを防止できる。この中子２０は金型２４内
に固定され、この金型２４内にワックスや発泡スチロー
ルなどの消失模型材料を射出して消失模型２４を成形す
る（ステップ１１２、第２図Ｅ）。このように中子２０
を鋳ぐるんだ状態の消失模型２６の外側には、耐火物が
コーティングされる。すなわちスラリ槽に浸漬して（ス
テップ１１４）スタッコ粒を振りかける（ステップ１１
６）工程を複数回繰り返し、所定厚さの耐火物層２８を
形成する（第２図Ｆ）。そしてこの耐火物層２８を十分
に乾燥させた後（ステップ１１８）、消失模型２１を脱
ろうして（ステップ１２０）さらに焼成する（ステップ
１２２）。脱ろうにより中子２０のワックス層２２も消
失し、中子２０の表面にはコーティング層１２が現れる
。この焼成によって外側の耐火物層２８と共に、内側の
ワックス層２２を除去した中子２０も同時に焼成される
。この結果中子２０、コーティング層１２を含むセラミ
ックシェル鋳型３０が出来上がる（第２図Ｆ）。Next, paraffin wax is applied to the core 20 thus obtained (step 110, FIG. 2D). This coating is carried out by immersing the core 20 with the coating layer 12 in paraffin wax melted at 80 to 90'C for about 10 minutes. As a result, a wax layer 22 is formed on the surface of the coating layer 12, thereby preventing sand from falling off the coating layer 12. In addition, the strength of the core 20 can be increased to prevent the core from being damaged during transport, and the core can be prevented from absorbing moisture during storage. The core 20 is fixed in a mold 24, and a vanishing model material such as wax or styrofoam is injected into the mold 24 to form the vanishing model 24 (step 112, FIG. 2E). In this way, the core 20
The outside of the vanishing model 26 in which it is cast is coated with a refractory material. That is, it is immersed in a slurry bath (step 114) and sprinkled with stucco particles (step 11).
6) Repeat the process multiple times to form a refractory layer 28 of a predetermined thickness (FIG. 2F). After this refractory layer 28 is sufficiently dried (step 118), the disappearing model 21 is dewaxed (step 120) and further fired (step 122). By dewaxing, the wax layer 22 of the core 20 also disappears, and the coating layer 12 appears on the surface of the core 20. By this firing, the core 20 from which the inner wax layer 22 has been removed is simultaneously fired together with the outer refractory layer 28. As a result, a ceramic shell mold 30 including a core 20 and a coating layer 12 is completed (FIG. 2F).
次にこの鋳型３０内、すなわち耐火物層２８とコーティ
ング層１２とで挟まれる間隙に金属溶湯が注湯される（
ステップ１２４）。そして冷却後型ばらしされ（ステッ
プ１２６）、中子２０とコーティング層１２が除去され
る（ステップ１２８）。この中子２０およびコーティン
グ層１２の除去は、例えば振動や衝票などの物理的手段
により中子の大部分を除去し、残部を溶融苛性ソーダに
浸漬してこれを溶融することにより行われる。この結果
製品３２が完成する（第２図Ｇ）。特に中子２０は予め
焼結するものではないから、中子の崩壊性が良好である
。Next, molten metal is poured into the mold 30, that is, into the gap between the refractory layer 28 and the coating layer 12.
Step 124). After cooling, the mold is demolded (step 126), and the core 20 and coating layer 12 are removed (step 128). The core 20 and the coating layer 12 are removed by, for example, removing most of the core by physical means such as vibration or stamping, and immersing the remainder in molten caustic soda to melt it. As a result, a product 32 is completed (FIG. 2G). In particular, since the core 20 is not sintered in advance, the core has good collapsibility.
この第１発明に用いる骨材、バインダ等は前記実施例に
限られるものではないのは勿論である。It goes without saying that the aggregate, binder, etc. used in the first invention are not limited to those in the embodiments described above.
例えば骨材としてはけい砂に代えてアルミナ、溶融シリ
カ、ジルコン、溶融ムライトなどを用いることが可能で
ある。またこの骨材に混練する無機バインダとしては燐
酸セメント等も使用可能である。For example, instead of silica sand, alumina, fused silica, zircon, fused mullite, etc. can be used as the aggregate. Also, phosphoric acid cement or the like can be used as an inorganic binder to be mixed into this aggregate.
第３図は本願第２発明の一実施例の行程流れ図である。FIG. 3 is a process flowchart of an embodiment of the second invention of the present application.
この実施例は前記第１図の実施例におけるステップ１０
８の後に、高温用バインダを含浸する工程１３２を付加
したものである。このステップ１３２において含浸する
高温用バインダとしてはエチルシリケートやコロイダル
シリカが使用可能である。本実施例ではこのように中子
に高温用バインダを含浸させるので混練物には高温用バ
インダを必ずしも混入しておく必要がない。This embodiment corresponds to step 10 in the embodiment of FIG.
After step 8, a step 132 of impregnating a high temperature binder is added. As the high temperature binder impregnated in step 132, ethyl silicate or colloidal silica can be used. In this embodiment, since the core is impregnated with the high-temperature binder as described above, it is not necessary to mix the high-temperature binder into the kneaded material.
従って例えばメタ珪酸ソーダ等の粉末状無機バインダを
けい砂等の骨材にコーティングしてなる無機バインダコ
ーテツドサンドをステップ（ｂ）における混練物として
用いることが可能となる。このコーテツドサンドは、誘
電加熱によりコーティング層から発生する高温の水蒸気
がこのコーテツドサンドを通過することにより硬化する
。このコーテツドサンドは乾燥した流動性に富むものあ
るためいわゆる乾式流動成形が可能となり、中子の型内
の混練物（コーテツドサンド）の充填性が良く中子の寸
法精度を一層高めることが可能となる。Therefore, it is possible to use an inorganic binder coated sand obtained by coating an aggregate such as silica sand with a powdered inorganic binder such as sodium metasilicate as the kneaded material in step (b). This coated sand is hardened by passing high temperature water vapor generated from the coating layer through the coated sand by dielectric heating. Since this coated sand is dry and highly fluid, so-called dry flow molding is possible, and the kneaded material (coated sand) in the core mold has good filling properties and can further improve the dimensional accuracy of the core. It becomes possible.
なおこの第２発明において、低温用バインダと高温用バ
インダとを骨材に混練した混練物を用いることは勿論可
能であり、本第２発明はこれを包含する。この場合には
中子の熱間強度が一層向上する効果がある。In this second invention, it is of course possible to use a kneaded material in which a low-temperature binder and a high-temperature binder are kneaded into aggregate, and the second invention includes this. In this case, the hot strength of the core is further improved.
以りの各実施例ではワックスを塗布するステップ１１０
を有するので、このワックス層がコーティング層および
中子の強度を増大させ、中子を移送時に痛めるおそれが
なくなる。また中子の保存中に中子が水分を吸収して中
子焼成時に中子が破損するなどの不都合を防止できる。Each of the following embodiments includes step 110 of applying wax.
This wax layer increases the strength of the coating layer and the core, eliminating the risk of damaging the core during transportation. Further, it is possible to prevent inconveniences such as the core absorbing moisture during storage and being damaged during core firing.
しかし本発明はこのステップ１１０を省いても所期の目
的は達成可能である。However, in the present invention, the intended purpose can be achieved even if this step 110 is omitted.
（発明の効果）
以上のように本願の第１発明は、中子型に予めスラリの
コーティング層を形成した後この中子型内に骨材とバイ
ンダとの混練物を充填し、これを誘電加熱することによ
りコーティング層と混練物とを一度に硬化させるもので
あるから、中子の肌を滑らかにでき、中子の寸法精度を
高くすることができる。また中子は外側の鋳型と共に焼
成されるから、中子単独での焼成、焼結が不要となり。(Effects of the Invention) As described above, the first invention of the present application is to form a coating layer of slurry on a core mold in advance, fill the core mold with a kneaded mixture of aggregate and a binder, and apply the dielectric material to the core mold. Since the coating layer and the kneaded material are cured at once by heating, the skin of the core can be made smooth and the dimensional accuracy of the core can be increased. Additionally, since the core is fired together with the outer mold, there is no need to fire or sinter the core alone.
生産工程が単純で生産性向上とコスト低下が可能になる
。さらに焼成に併う中子の熱ひずみが少なくなるために
寸法精度は一層向上し中子の崩壊性が良好となり中子の
除去が容易になる。特に鋳型を形成する耐火物層と同質
の材料を中子に使用すれば、中子と耐火物層との熱膨張
などのコントロールが容易であり、大型の鋳造に好適な
ものになる。The production process is simple, making it possible to improve productivity and reduce costs. Furthermore, since thermal distortion of the core during firing is reduced, dimensional accuracy is further improved, the core has good collapsibility, and removal of the core is facilitated. In particular, if the same material as the refractory layer forming the mold is used for the core, thermal expansion between the core and the refractory layer can be easily controlled, making it suitable for large-scale casting.
またコーティング層が中子素体の表面を滑らかにし、鋳
造製品の中子側の表面が荒れるのを防止できる。またこ
のコーティング層は溶湯と中子とのモールトリアクショ
ンを抑制し製品表面の荒れを防止する働きをする。さら
に鋳型の焼成時あるいは注湯時に中子が高温になった際
にも、このコーティング層は中子の熱間強度を一層増大
させているので破損しにくく、鋳造歩止まりが一層向上
する。In addition, the coating layer smoothes the surface of the core body and prevents the surface of the core side of the cast product from becoming rough. This coating layer also suppresses the mold reaction between the molten metal and the core and prevents the surface of the product from becoming rough. Furthermore, even when the core reaches a high temperature during firing or pouring of the mold, this coating layer further increases the hot strength of the core, making it less likely to be damaged, further improving the casting yield.
第２発明によれば、高温用バインダを含浸させることに
より中子強度を一層向上させると共に、混練物に高温用
バインダを混入するのを省いたり流動性に富む無機バイ
ンダコーテツドサンドの使用も可能となる。特にコーテ
ツドサンドを用いる場合には中子型内へのコーテツドサ
ンドの充填性が良くなり、中子の寸法精度も一層向上す
る。According to the second invention, the strength of the core is further improved by impregnating it with a high-temperature binder, and it is also possible to omit mixing the high-temperature binder into the kneaded material and to use inorganic binder-coated sand with high fluidity. becomes. In particular, when coated sand is used, the filling properties of the coated sand into the core mold are improved, and the dimensional accuracy of the core is further improved.
第１図は本願第１発明の一実施例の工程流れ図、第２図
はその各工程の説明図、第３図は本願第２発明の一実施
例の工程流れ図である。
１０・・・中子型、
１２・・・コーティング層。
２２・・・ワックス層、
２６・・・消失模型、
３０・・・鋳型、３２・・・製品。FIG. 1 is a process flowchart of an embodiment of the first invention of the present application, FIG. 2 is an explanatory diagram of each process, and FIG. 3 is a process flowchart of an embodiment of the second invention of the present application. 10... Core mold, 12... Coating layer. 22... Wax layer, 26... Vanishing model, 30... Mold, 32... Product.
Claims (6)
メント鋳造用鋳型の製造方法： （ａ）中子型にスラリを流入して中子型内面にスラリの
コーティング層を形成し余分のスラリを排出する工程； （ｂ）骨材とバインダとの混練物を前記中子型内に充填
する工程； （ｃ）中子型の外側からマイクロ波誘電加熱によりスラ
リコーティング層と混練物とを加熱乾燥し硬化する工程
； （ｄ）中子型から中子を取出す工程； （ｅ）この中子を型内に位置決めしてこの型内に消失模
型材を注入し、中子を鋳ぐるんだ消失模型を形成する工
程； （ｆ）この消失模型にスラリおよびスタッコ粒を交互に
複数回塗布して耐火物層を形成し乾燥する工程； （ｇ）消失模型を消失させて鋳型を形成する工程；（ｈ
）中子と耐火物層とを同時に焼成する工程。(1) A method for manufacturing an investment casting mold, which is characterized by the following steps: (a) Slurry is poured into the core mold to form a coating layer of slurry on the inner surface of the core mold, and excess slurry is discharged. (b) filling the core mold with a kneaded mixture of aggregate and binder; (c) heating and drying the slurry coating layer and the kneaded material by microwave dielectric heating from the outside of the core mold; Hardening process; (d) Process of taking out the core from the core mold; (e) Positioning the core in the mold and injecting the vanishing model material into the mold to create a vanishing model in which the core is cast. (f) Step of forming a refractory layer by applying slurry and stucco granules alternately multiple times on this vanishing model and drying; (g) Forming a mold by vanishing the vanishing model; ( h
) A process of firing the core and the refractory layer at the same time.
の大きい無機バインダと、高温強度の高い高温用バイン
ダとを含むことを特徴とする特許請求の範囲第１項記載
のインベストメント鋳造用鋳型の製造方法。(2) In step (b), the binder includes an inorganic binder with high low-temperature caking strength and a high-temperature binder with high high-temperature strength. manufacturing method.
とすることを特徴とする特許請求の範囲第１項記載のイ
ンベストメント鋳造用鋳型の製造方法。(3) The method for manufacturing an investment casting mold according to claim 1, wherein in step (b), the aggregate is mainly composed of silica sand.
バインダはエチルシリケートおよびコロイダルシリカの
少くとも一方を含むことを特徴とする特許請求の範囲第
２項記載のインベストメント鋳造用鋳型の製造方法。(4) The method for manufacturing an investment casting mold according to claim 2, wherein the inorganic binder contains sodium silicate as a main component, and the high-temperature binder contains at least one of ethyl silicate and colloidal silica.
メント鋳造用鋳型の製造方法： （ａ）中子型にスラリを流入して中子型内面にスラリの
コーティング層を形成し余分のスラリを排出する工程； （ｂ）骨材とバインダとの混練物を前記中子型内に充填
する工程； （ｃ）中子型の外側からマイクロ波誘電加熱によりスラ
リコーティング層と混練物とを加熱乾燥し硬化する工程
； （ｄ）中子型から中子を取出す工程； （ｅ）この中子に高温強度の高い高温用バインダを含浸
させた後乾燥する行程； （ｆ）この中子を型内に位置決めしてこの型内に消失模
型材を注入し、中子を鋳ぐるんだ消失模型を形成する工
程； （ｇ）この消失模型にスラリおよびスタッコ粒を交互に
複数回塗布して耐火物層を形成し乾燥する工程； （ｈ）消失模型を消失させて鋳型を形成する工程；（ｉ
）中子と耐火物層とを同時に焼成する工程。(5) A method for manufacturing an investment casting mold characterized by the following steps: (a) Slurry is poured into the core mold to form a coating layer of slurry on the inner surface of the core mold, and excess slurry is discharged. (b) filling the core mold with a kneaded mixture of aggregate and binder; (c) heating and drying the slurry coating layer and the kneaded material by microwave dielectric heating from the outside of the core mold; Hardening process; (d) Taking out the core from the core mold; (e) Drying after impregnating the core with a high-temperature binder that has high high-temperature strength; (f) Inserting the core into the mold. A process of positioning and injecting the dissipation model material into this mold to form a dissipation model with the core cast around it; (g) applying slurry and stucco particles alternately multiple times to this dissipation model to form a refractory layer; a step of forming and drying; (h) a step of forming a mold by making the disappearing model disappear; (i
) A process of firing the core and the refractory layer at the same time.
ダ等の粉末状無機バインダを骨材にコーティングしてな
る無機バインダコーテッドサンドで形成されていること
を特徴とする特許請求の範囲第５項記載のインベストメ
ント鋳造用鋳型の製造方法。(6) In the step (b), the kneaded material is formed of inorganic binder coated sand obtained by coating aggregate with a powdered inorganic binder such as sodium metasilicate. A method for manufacturing an investment casting mold as described in .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62076293A JPS63242439A (en) | 1987-03-31 | 1987-03-31 | Production of mold for investment casting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62076293A JPS63242439A (en) | 1987-03-31 | 1987-03-31 | Production of mold for investment casting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63242439A true JPS63242439A (en) | 1988-10-07 |
| JPH0262103B2 JPH0262103B2 (en) | 1990-12-21 |
Family
ID=13601298
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62076293A Granted JPS63242439A (en) | 1987-03-31 | 1987-03-31 | Production of mold for investment casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63242439A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6749006B1 (en) | 2000-10-16 | 2004-06-15 | Howmet Research Corporation | Method of making investment casting molds |
| JP2008142777A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Disposable insert, and use thereof in method for manufacturing airfoil |
| JP2008142778A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Composite core die, method of manufacturing thereof and article manufactured therefrom |
| JP2008142779A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Ceramic cores, methods of manufacture thereof and articles manufactured from the same |
| JP2008155284A (en) * | 2006-12-06 | 2008-07-10 | General Electric Co <Ge> | Casting composition for manufacturing metallic casting and method of manufacturing thereof |
| US9863254B2 (en) | 2012-04-23 | 2018-01-09 | General Electric Company | Turbine airfoil with local wall thickness control |
| CN108115093A (en) * | 2017-12-23 | 2018-06-05 | 安徽鑫宏机械有限公司 | A kind of gypsum shell full form casting process based on composite sand mould loam core |
-
1987
- 1987-03-31 JP JP62076293A patent/JPS63242439A/en active Granted
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6749006B1 (en) | 2000-10-16 | 2004-06-15 | Howmet Research Corporation | Method of making investment casting molds |
| JP2008142777A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Disposable insert, and use thereof in method for manufacturing airfoil |
| JP2008142778A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Composite core die, method of manufacturing thereof and article manufactured therefrom |
| JP2008142779A (en) * | 2006-12-06 | 2008-06-26 | General Electric Co <Ge> | Ceramic cores, methods of manufacture thereof and articles manufactured from the same |
| JP2008155284A (en) * | 2006-12-06 | 2008-07-10 | General Electric Co <Ge> | Casting composition for manufacturing metallic casting and method of manufacturing thereof |
| US9566642B2 (en) | 2006-12-06 | 2017-02-14 | General Electric Company | Composite core die, methods of manufacture thereof and articles manufactured therefrom |
| US9863254B2 (en) | 2012-04-23 | 2018-01-09 | General Electric Company | Turbine airfoil with local wall thickness control |
| CN108115093A (en) * | 2017-12-23 | 2018-06-05 | 安徽鑫宏机械有限公司 | A kind of gypsum shell full form casting process based on composite sand mould loam core |
| CN108115093B (en) * | 2017-12-23 | 2019-09-06 | 安徽鑫宏机械有限公司 | A kind of plaster mold shell full form casting process based on composite sand mould loam core |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0262103B2 (en) | 1990-12-21 |
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