JPH078408B2 - Core sand mold manufacturing method - Google Patents
Core sand mold manufacturing methodInfo
- Publication number
- JPH078408B2 JPH078408B2 JP10976787A JP10976787A JPH078408B2 JP H078408 B2 JPH078408 B2 JP H078408B2 JP 10976787 A JP10976787 A JP 10976787A JP 10976787 A JP10976787 A JP 10976787A JP H078408 B2 JPH078408 B2 JP H078408B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- sand mold
- sand
- resin
- core sand
- 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 - Lifetime
Links
- 239000004576 sand Substances 0.000 title claims description 44
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- 239000007849 furan resin Substances 0.000 claims description 12
- 239000005011 phenolic resin Substances 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 239000011347 resin Substances 0.000 claims description 10
- 229920005989 resin Polymers 0.000 claims description 10
- 239000003513 alkali Substances 0.000 claims description 8
- 239000011230 binding agent Substances 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 4
- 150000002148 esters Chemical class 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 238000007493 shaping process Methods 0.000 claims 1
- 238000000034 method Methods 0.000 description 17
- 238000005266 casting Methods 0.000 description 14
- 238000000465 moulding Methods 0.000 description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical compound OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 description 3
- 229910001208 Crucible steel Inorganic materials 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 230000008094 contradictory effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- JIRHAGAOHOYLNO-UHFFFAOYSA-N (3-cyclopentyloxy-4-methoxyphenyl)methanol Chemical compound COC1=CC=C(CO)C=C1OC1CCCC1 JIRHAGAOHOYLNO-UHFFFAOYSA-N 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- -1 formic acid ester Chemical class 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000004848 polyfunctional curative Substances 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Mold Materials And Core Materials (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、鋳鋼品や鋳造品製作のための鋳物砂型の製造
方法に関し、特にフラン樹脂粘結剤を用いた主型砂型と
組み合わせて使用する中子砂型の製造方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for producing a casting sand mold for producing a cast steel product or a cast product, and in particular used in combination with a main mold sand mold using a furan resin binder. The present invention relates to a method for manufacturing a core sand mold.
第２図及び第３図に、従来のフラン樹脂造型プロセスで
の鋳型製造方法を示す。2 and 3 show a mold manufacturing method in a conventional furan resin molding process.
第２図においては、フラン樹脂造型プロセスで製作され
た主型砂型１に、フラン樹脂造型プロセスで製作された
中子砂型５が納められて、製品４を作るための空間３が
形成される。この第２図（ａ）の鋳型に鋳込んで第２図
（ｂ）に示す製品４を製作した場合、鋳物欠陥であるク
ラツク６やプロホール７が発生し易い。In FIG. 2, the core sand mold 5 manufactured by the furan resin molding process is accommodated in the main mold sand mold 1 manufactured by the furan resin molding process, and the space 3 for making the product 4 is formed. When the product 4 shown in FIG. 2 (b) is manufactured by casting in the mold of FIG. 2 (a), cracks 6 and pro holes 7 which are casting defects are likely to occur.
また、第３図において、フラン樹脂造型プロセスで製作
された主型砂型１に、水ガラス系の無機自硬タイプのダ
イヤル造型プロセスで製作された中子砂型８が納められ
て、製品４を作るための空間３が形成されている。この
第３図（ａ）の鋳型に鋳込んで第３図（ｂ）に示す製品
４を製作した場合、鋳物欠陥の発生は少ないが、中子砂
型８の崩壊性が悪い。Further, in FIG. 3, a core sand mold 8 manufactured by a water glass-based inorganic self-hardening dial molding process is housed in a main mold sand mold 1 manufactured by a furan resin molding process to make a product 4. A space 3 for forming is formed. When the product 4 shown in FIG. 3 (b) is manufactured by casting in the mold of FIG. 3 (a), casting defects are less likely to occur, but the core sand mold 8 has poor collapsibility.
ところで、溶湯の凝固にともなう収縮時に鋳型が収縮す
る性質を「なりより性」というが、一般に無機粘結剤を
用いる造型プロセスでは、なりより性が優れているが、
中子砂型として用いる場合には上記のように崩壊性が悪
く、また、一般に有機系粘結剤を用いる造型プロセスで
は崩壊性が良好であるがなりより性が劣つている。By the way, the property that the mold shrinks at the time of shrinkage with solidification of the molten metal is called "nariyori", but in the molding process using an inorganic binder, the property is much better,
When it is used as a core sand mold, the disintegration property is poor as described above, and in general, in the molding process using an organic binder, the disintegration property is good but the property is inferior.
本発明は、上記問題点を解消し、クラツクやブロホール
の発生を回避し、なりより性と崩壊性がいずれも良好な
造型プロセスを用いた中子砂型の製造方法を提供しよう
とするものである。The present invention is intended to solve the above problems, to avoid the generation of cracks and brohols, and to provide a method for producing a core sand mold using a molding process in which both the bending property and the disintegration property are good. .
本発明は、粘結剤としてフラン樹脂を含有する主型砂型
と組み合わせて使用する中子砂型の製造方法において、
砂に対して0.9〜1.9重量％のアルカリフエノール樹脂を
粘結剤として、かつ、該樹脂に対して15〜31重量％のエ
ステルを硬化剤として配合して造形した後200℃以下で
乾燥することを特徴とする中子砂型の製造方法である。The present invention, in a method for producing a core sand mold used in combination with a main sand mold containing a furan resin as a binder,
Drying at 200 ° C or less after blending 0.9 to 1.9% by weight of alkaline phenol resin as a binder with respect to sand and 15 to 31% by weight of ester as a curing agent with respect to the resin Is a method for manufacturing a core sand mold.
従来使用されているフラン樹脂造型プロセスでは尿素を
含むフルフリルアルコール系の樹脂を用い、キシレンス
ルホン酸系の硬化剤を使用するために樹脂中の窒素が鋳
鋼ではブロホールとなり、硬化剤中の硫黄がクラツクの
原因となるが、本発明の中子砂型は窒素や硫黄を含まな
いアルカリフエノール樹脂とエステル系の硬化剤を用い
るために、ブロホールやクラツクを発生することはな
い。また、一般的に相反する性状と考えられていたなり
より性と崩壊性を、アルカリフエノール樹脂の選択によ
り同時満すことが可能となつた。In the conventional furan resin molding process, a furfuryl alcohol-based resin containing urea is used.Since a xylene sulfonic acid-based curing agent is used, nitrogen in the resin becomes a brohol in cast steel, and sulfur in the curing agent is changed. Although it causes cracks, the core sand mold of the present invention does not generate brohol or cracks because it uses an alkali phenol resin containing no nitrogen or sulfur and an ester type curing agent. In addition, it was possible to simultaneously satisfy the rather contradictory properties and disintegration properties that were generally considered to be contradictory properties, by selecting an alkali phenol resin.
また、砂の再使用に関しては、フラン樹脂を用いた鋳型
では再生率が約95％と高いのに対して、フエノール樹脂
では約80％であることから、使用量の多い主型砂型にフ
ラン樹脂を使用し、中子砂型にフエノール樹脂を用いる
こととした。Regarding the reuse of sand, the rate of regeneration is about 95% for molds using furan resin, whereas it is about 80% for phenol resin. Was used, and a phenol resin was used for the core sand mold.
次に、アルカリフエノール樹脂と硬化剤の添加量につい
て説明する。鋳型は鋳造作業に適した強度を必要とす
る。そこで、鋳物砂試験法として一般的に使用される
「24H抗圧力」を強度の指標として用い、上記添加量と
の関係を調べた。Next, the addition amounts of the alkali phenol resin and the curing agent will be described. The mold should have sufficient strength for the casting operation. Therefore, using the "24H coercive pressure" generally used as a casting sand test method as an index of strength, the relationship with the above-mentioned addition amount was investigated.
なお、「24H抗圧力」とは混練した砂を50φ×80の型に
入れて24時間放置した後の強度をいい、「24H抗圧力」
と最も関係の深い樹脂の添加量との関係で言えば、添加
量が少なければ鋳型の強度が低下して運搬時にクラツク
が発生する。また、添加量が多くなれば強度は向上する
ものの、表面にザラツキ状態が発生する。そこで、上記
条件を考慮して、本発明では気温30℃における24H抗圧
力が20〜40kg/cm2となる範囲をそれぞれの添加量とし
た。In addition, "24H coercive pressure" means the strength after putting kneaded sand in a 50φ x 80 mold and leaving it for 24 hours.
In terms of the relationship with the most closely related resin addition amount, if the addition amount is small, the strength of the mold decreases and cracking occurs during transportation. Further, if the amount of addition is large, the strength is improved, but a rough state occurs on the surface. Therefore, in consideration of the above conditions, in the present invention, the range of 24H coercive pressure at an air temperature of 30 ° C. of 20 to 40 kg / cm 2 was set as each addition amount.
ここで、気温30℃における24H抗圧力の下限を20kg/cm2
とした理由は、冬期にはこの半分の強度となることが考
えられ、その10kg/cm2という強度が砂型から模型を抜き
取るための不可欠な条件となるためである。また、上限
については、これ以上の強度では鋳込前の鋳型乾燥によ
り、未反応の樹脂の硬化反応が促進されて、過硬化（15
0kg/cm2以上）となるだけである。特に、夏期に気温が3
0℃以上に上がる場合には混練後の砂の可使時間が短か
くなるために（約５〜10分程度）造型作業の途中で硬化
し始め、鋳型のボロつきや強度不足になるためである。Here, the lower limit of the 24H coercive pressure at an air temperature of 30 ° C is set to 20 kg / cm 2
The reason is that the strength is considered to be half this in winter, and the strength of 10 kg / cm 2 is an indispensable condition for removing the model from the sand mold. Regarding the upper limit, if the strength is higher than this, the curing reaction of the unreacted resin is promoted by the mold drying before casting, and the overcuring (15
0kg / cm 2 or more). Especially in summer, the temperature is 3
If the temperature rises above 0 ° C, the pot life of the sand after kneading will become short (about 5 to 10 minutes) and it will begin to harden during the molding process, causing the mold to become fragile and lacking in strength. is there.
ところで、24H抗圧力と添加量の関係を調べる実験は、
まず、新砂に粘結剤としてアルカリフエノール樹脂を、
また、硬化剤としてギ酸エステルを添加して30℃で混練
し24時間後の強度を調べた。第４図及び第５図に実験結
果を示す。なお、第４図は硬化剤を15〜31wt％の範囲の
中で一定として樹脂の添加量を変えて得たものであり、
第５図は樹脂の添加量を対砂比1.5wt％で一定にして硬
化剤を変化させて求めたデータである。両図より明らか
なように、気温30℃における24H抗圧力が20〜40kg/cm2
となる範囲はアルカリフエノール樹脂の対砂比について
は0.9〜1.9wt％であり、エステル硬化剤の対樹脂比につ
いては15〜31wt％であつた。By the way, in the experiment to investigate the relationship between 24H coercive pressure and the amount added,
First of all, an alkaline phenol resin as a binder is added to fresh sand.
Further, formic acid ester was added as a curing agent, and the mixture was kneaded at 30 ° C. and the strength after 24 hours was examined. Experimental results are shown in FIGS. 4 and 5. Incidentally, FIG. 4 is obtained by changing the addition amount of the resin while keeping the curing agent constant within the range of 15 to 31 wt%,
FIG. 5 shows data obtained by changing the curing agent while keeping the amount of resin added at a constant sand-to-sand ratio of 1.5 wt%. As is clear from both figures, the 24H coercive pressure at an air temperature of 30 ° C is 20 to 40 kg / cm 2
The range was from 0.9 to 1.9 wt% for the alkali phenol resin to sand ratio and from 15 to 31 wt% for the ester curing agent to resin ratio.
また、造型プロセスにおける鋳型の乾燥、予熱温度を20
0℃以下とした理由はこの温度以上となるとなりより性
が小さくなり適当でなくなるためである。In addition, the mold drying and preheating temperature in the molding process are set to 20
The reason why the temperature is 0 ° C. or lower is that when the temperature is higher than this temperature, the property becomes smaller and it becomes unsuitable.
以下、本発明の方法に基づき、半円筒状製品を製作する
例を第１図により説明する。第１図（ａ）は鋳込前、同
（ｂ）は鋳込後の状態を示す。上記のように、フラン樹
脂造型プロセスにより製造した主型砂型１にアルカリフ
エノール樹脂造型プロセスによる中子砂型２を納めて空
間３を形成する。この際、中子砂型２を製作するには、
次の事項に注意を要する。An example of producing a semi-cylindrical product based on the method of the present invention will be described below with reference to FIG. FIG. 1 (a) shows a state before casting, and FIG. 1 (b) shows a state after casting. As described above, the space 3 is formed by accommodating the core sand mold 2 by the alkali phenol resin molding process in the main mold sand mold 1 manufactured by the furan resin molding process. At this time, to make the core sand mold 2,
Pay attention to the following matters.
（１） 硬化後の砂強度が不足気味（従来法に比べ、約
20〜30％ダウン）の場合には、砂かみ対策を採る。（例
えば、堰先にジルコン砂やクロマト砂を使用し、アルコ
ール塗型の多用をさける。） （２） アルコールによつて硬化後の砂が軟化するた
め、アルコール塗型を使用した後は、ある程度の保持時
間を設け、すぐに運搬しない。(1) The sand strength after hardening seems to be insufficient (compared to the conventional method,
In the case of 20-30% down), take measures against sand bite. (For example, zircon sand or chromatographic sand is used for the weir, avoiding heavy use of alcohol coating type.) (2) Alcohol coating type is used to soften the sand after curing There is a holding time, and do not transport immediately.
（３） 製品４のような、半円筒状の製品（例えば、タ
ービ車室等）の場合には、長さ（Ｌ）や高さ（Ｈ）方向
に比べ、幅（ｗ）の方向が凝固収縮しにくいため、予め
模型で調整するか、鋳造方案で補正代をつける等の対策
が必要である。但し、円筒状の製品（例えば、弁室等）
については、３方向はすべて同じ収縮量を有するので調
整の必要はない。(3) In the case of a semi-cylindrical product (for example, a turbine compartment) like the product 4, the width (w) direction is more solidified than the length (L) or height (H) direction. Since it does not shrink easily, it is necessary to take measures such as adjusting with a model in advance or adding a compensation allowance in the casting plan. However, cylindrical products (for example, valve chambers)
In regard to (3), all three directions have the same shrinkage amount, and thus no adjustment is necessary.
30mmの薄肉の弁室を本発明の方法により作成した。主型
砂型は再生砂にフラン樹脂を加えて水性系塗型で作つ
た。また、中子砂型は新砂（肌砂‐クロマイト）に対砂
比1.5wt％でアルカリフエノール樹脂を、また対樹脂比3
0wt％で硬化剤を添加し、アルコール系塗型で作成し、1
50℃で10時間鋳型を乾燥した。A thin 30 mm valve chamber was made by the method of the present invention. The main sand mold was made by adding a furan resin to recycled sand and using an aqueous coating mold. In addition, the core sand type is a new sand (skin sand-chromite) with an alkali phenol resin at a sand ratio of 1.5 wt% and a resin ratio of 3
Add a curing agent at 0 wt% and make with an alcohol-based coating type, 1
The mold was dried at 50 ° C for 10 hours.
鋳込みは、SC42（C:0.18％,Si:0.4％,Mn:0.7％）の材料
を1590℃の鋳込温度で行なつた。得られた弁室は上記の
条件で従来のフラン樹脂中子砂型を用いた場合に比較い
てブローホールが30％，クラツクが30％減少した。Casting was performed with SC42 (C: 0.18%, Si: 0.4%, Mn: 0.7%) material at a casting temperature of 1590 ° C. The resulting valve chamber had blowholes reduced by 30% and cracks reduced by 30% compared to the case of using the conventional furan resin core sand mold under the above conditions.
本発明は上記構成を採用することにより、適度の24H抗
圧力を有し、かつ、なりより性が大きく、鋳込後の崩壊
性に優れた中子砂型を得ることができ、該砂型を用いた
鋳物製品は従来品に比してクラツクやブローホールを大
巾に低下させることができた。The present invention, by adopting the above-mentioned constitution, has a proper 24H coercive pressure, and has a greater flexibility, and it is possible to obtain a core sand mold excellent in disintegration after casting, and the sand mold is used. Compared with the conventional products, the cast products that were produced were able to greatly reduce cracks and blowholes.
第１図は、本発明による鋳型製造プロセスを、第２図及
び第３図は、従来の鋳型製造プロセスの説明図である。 第４図は、アルカリフエノール樹脂添加量と24H抗圧力
の関係を示し、第５図は、硬化剤添加量と24Hr抗圧力の
関係を示す。FIG. 1 is a mold manufacturing process according to the present invention, and FIGS. 2 and 3 are explanatory views of a conventional mold manufacturing process. FIG. 4 shows the relationship between the amount of alkali phenol resin added and 24H coercive pressure, and FIG. 5 shows the relationship between the amount of hardener added and 24Hr coercive pressure.
Claims (1)
型と組み合わせて使用する中子砂型の製造方法におい
て、砂に対して0.9〜1.9重量％のアルカリフエノール樹
脂を粘結剤として、かつ、該樹脂に対して15〜31重量％
のエステルを硬化剤として配合して造形した後200℃以
下で乾燥することを特徴とする中子砂型の製造方法。1. A method for producing a core sand mold which is used in combination with a main mold sand mold containing a furan resin as a binder, wherein 0.9 to 1.9% by weight of an alkali phenol resin is used as a binder, and , 15 to 31% by weight with respect to the resin
A method for producing a core sand mold, which comprises blending the ester of 1) as a curing agent, shaping the mixture, and then drying at 200 ° C. or lower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10976787A JPH078408B2 (en) | 1987-05-07 | 1987-05-07 | Core sand mold manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10976787A JPH078408B2 (en) | 1987-05-07 | 1987-05-07 | Core sand mold manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63278637A JPS63278637A (en) | 1988-11-16 |
| JPH078408B2 true JPH078408B2 (en) | 1995-02-01 |
Family
ID=14518713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10976787A Expired - Lifetime JPH078408B2 (en) | 1987-05-07 | 1987-05-07 | Core sand mold manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH078408B2 (en) |
-
1987
- 1987-05-07 JP JP10976787A patent/JPH078408B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63278637A (en) | 1988-11-16 |
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