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JPH06226422A - Reduced pressure shell mold casting method - Google Patents

Reduced pressure shell mold casting method

Info

Publication number
JPH06226422A
JPH06226422A JP5015138A JP1513893A JPH06226422A JP H06226422 A JPH06226422 A JP H06226422A JP 5015138 A JP5015138 A JP 5015138A JP 1513893 A JP1513893 A JP 1513893A JP H06226422 A JPH06226422 A JP H06226422A
Authority
JP
Japan
Prior art keywords
self
sprue
molten metal
mold
tube
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
Application number
JP5015138A
Other languages
Japanese (ja)
Other versions
JPH0818122B2 (en
Inventor
Yoshio Takeichi
良生 竹市
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.)
DAIICHI CHUZO KK
Original Assignee
DAIICHI CHUZO KK
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 DAIICHI CHUZO KK filed Critical DAIICHI CHUZO KK
Priority to JP5015138A priority Critical patent/JPH0818122B2/en
Publication of JPH06226422A publication Critical patent/JPH06226422A/en
Publication of JPH0818122B2 publication Critical patent/JPH0818122B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PURPOSE:To make possible a precision casting without the mixing of impurity and deformation and strain by connecting the intramold space in a self-curing and a non-consumable sprue tube with a lost foam sprue tube made of foaming resin and pouring molten metal while reducing the pressure in a molding flask. CONSTITUTION:The self-curing mold 1 composed of a shell mold furan resin or CO2 sand is embedded into the inner part of dry sand 4 or shot balls in the molding flask 3 capable of reducing pressure. Together with this, the intramold space in this self-curing mold 1 and the non-consumable sprue tube 7 are connected with the lost foam sprue tube 5 made of the foaming resin. Then, while reducing the pressure in the molding flask 3 through a gauze pipe 8 for pressure reducing, the molten metal is poured from the upper part of a sprue cup 11. The molten metal reaches the lost foam sprue tube 5 through the non-consumable sprue tube 7, and while melting the lost foam sprue, tube, the molten metal is cast into the intramold space in the self-curing mold 1 from a strainer hole 6. By this method, without wasting much molten metal, the development of shrinkage cavity at the outer part and blow hole, etc., can be prevented.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、シェルモールド鋳造法
と減圧フルモールド鋳造法の長所を組合せた精密鋳造、
高品質大量生産鋳造に適した減圧シェルモールド鋳造法
に関するものである。
BACKGROUND OF THE INVENTION The present invention relates to precision casting which combines the advantages of shell mold casting and vacuum full mold casting.
The present invention relates to a reduced pressure shell mold casting method suitable for high quality mass production casting.

【0002】[0002]

【従来の技術】シェルモールド鋳造法と減圧フルモール
ド鋳造法は、精密鋳造法として従来から知られている。
シェルモールド鋳造法は、周知のように模型の表面にシ
ェルモールド・フラン樹脂又はCO2 砂を塗布して硬化さ
せることによりシェル状の自硬性鋳型を作成し、これを
用いて鋳造する方法である。この方法は多くの鋳造法の
中でも特に寸法精度鋳肌において優れた良品が得られる
こと、スタック法を用いて量産鋳造も可能であること、
鋳型強度もあり複雑形状の鋳造品にも適していること、
このためクランクシャフト等の量産鋳造に採用されてい
ること等の多くの利点をもつ。
2. Description of the Related Art A shell mold casting method and a reduced pressure full mold casting method are conventionally known as precision casting methods.
As is well known, the shell mold casting method is a method in which a shell-shaped self-hardening mold is created by applying shell mold furan resin or CO 2 sand to the surface of a model and curing it, and casting is performed using this. . This method can obtain a good product excellent in dimensional precision casting surface among many casting methods, that mass production casting is also possible using the stack method,
It has mold strength and is suitable for casting products with complicated shapes.
Therefore, it has many advantages such as being used for mass production casting of crankshafts and the like.

【0003】ところが、シェルモールド鋳造法は溶湯の
凝固過程において生ずる外部引け巣や気泡等を防止する
ために大きな押湯溜、揚がり等を設ける必要があり、多
大なむだ湯が生じること、また鋳造後の後処理工程が煩
雑であること等のために生産性の点でマイナスとなって
いるのが現状である。
However, in the shell mold casting method, it is necessary to provide a large feeder pool, frying and the like in order to prevent external shrinkage cavities and bubbles generated during the solidification process of the molten metal. The current situation is that productivity is negative due to complicated post-treatment processes.

【0004】一方、減圧フルモールド鋳造法は発泡ポリ
スチレン、発泡ポリウレタン等の発泡性樹脂からなる消
失性模型を減圧可能な枠内の乾燥砂やショットボール中
に埋設し、枠内を減圧したまま溶湯を注湯して消失性模
型と溶湯とを置換する方法である。この方法は上記した
ような欠点はないが、消失性模型の全体を消失させるた
めにススや発泡性樹脂の未消失残渣が鋳造品内に混入
し、品質不良を引き起こす原因となることがある。また
この方法は消失性模型の強度が低いために大型品となる
と変形・歪を生ずるおそれがある。
On the other hand, in the reduced pressure full mold casting method, an extinguishing model made of a foaming resin such as expanded polystyrene or polyurethane is buried in dry sand or shot balls in a depressurizable frame, and the molten metal is depressurized in the frame. It is a method of pouring molten metal to replace the extinction model and the molten metal. Although this method does not have the above-mentioned drawbacks, soot and undisappeared residues of the foaming resin may be mixed into the cast product to cause the disappearance of the entire extinction model, which may cause quality defects. Further, in this method, since the extinguishing model has low strength, it may be deformed or distorted in a large-sized product.

【0005】[0005]

【発明が解決しようとする課題】本発明は上記した従来
の問題点を解決し、多くのむだ湯を生ずることなく外部
引け巣や気泡等を防止することができ、また鋳造後の後
処理工程を削減することができ、更に未消失残渣による
品質不良や変形・歪を防止することができる生産性に優
れた鋳造法を提供するために完成されたものである。
DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems and can prevent external shrinkage cavities and bubbles without generating a large amount of waste water, and a post-treatment step after casting. The present invention has been completed to provide a casting method with excellent productivity that can reduce the number of defects and prevent quality defects and deformation / distortion due to undisappeared residues.

【0006】[0006]

【課題を解決するための手段】上記の課題を解決するた
めになされた本発明の減圧シェルモールド鋳造法は、減
圧可能な枠内に、シェルモールド・フラン樹脂又はCO2
砂からなる自硬性鋳型を埋設するとともに、発泡性樹脂
からなる消失性湯口管によってこの自硬性鋳型の型内空
間と非消失性湯口管とを接続し、枠内を減圧しながら溶
湯を注湯することを特徴とするものである。
The pressure-reducing shell mold casting method of the present invention, which has been made to solve the above-mentioned problems, uses a shell mold furan resin or CO 2 in a frame capable of reducing pressure.
While embedding a self-hardening mold made of sand, a disappearing spout pipe made of foaming resin is used to connect the internal space of this self-hardening mold to a non-dissipative spout pipe, and pouring molten metal while decompressing the inside of the frame. It is characterized by doing.

【0007】[0007]

【実施例】以下に本発明を実施例とともに更に詳細に説
明する。実施例はルーツ型真空ポンプのロータを本発明
の減圧シェルモールド鋳造法により鋳造する例を示すも
のである。まず図1に示すように、シェルモールド・フ
ラン樹脂又はCO2 砂によって自硬性鋳型1を作成する。
図中、1aは中心軸となる部分、1bはルーツ型の羽根部
分、1cは羽根中空部分であり、ハッチングを施した部分
が鋳型である。
EXAMPLES The present invention will be described in more detail below with reference to examples. The embodiment shows an example of casting a rotor of a roots type vacuum pump by the reduced pressure shell mold casting method of the present invention. First, as shown in FIG. 1, a self-hardening mold 1 is prepared from shell mold furan resin or CO 2 sand.
In the figure, 1a is a central axis portion, 1b is a roots type blade portion, 1c is a blade hollow portion, and a hatched portion is a mold.

【0008】次にこの自硬性鋳型1を図2に示すよう
に、減圧可能な枠3内の乾燥砂4やショットボールの内
部に埋設する。5は発泡ポリスチレン、発泡ポリウレタ
ン等の発泡性樹脂からなる消失性湯口管であり、その表
面には塗型剤層2が形成されている。この消失性湯口管
5の先端は自硬性鋳型1の下部に形成されたストレーナ
ホール6に密着されており、またその他端は陶管製湯口
管のような非消失性湯口管7に接続されている。11は非
消失性湯口管7の上端にセットされた湯口カップ、12は
自硬性鋳型1の上端にセットされた押湯カップである。
なお、枠3内には減圧用金網パイプ8が設けられている
とともに、乾燥砂4の表面には減圧シール用のフィルム
9がフィルム保護用蓋10に押さえられてセットされてお
り、枠3内の減圧が確実に行われるようになっている。
Next, as shown in FIG. 2, the self-hardening mold 1 is embedded in the dry sand 4 and the shot ball in the frame 3 capable of depressurizing. Reference numeral 5 denotes a disappearing sprue pipe made of a foaming resin such as expanded polystyrene or expanded polyurethane, and a mold coating agent layer 2 is formed on the surface thereof. The tip of the disappearing spout pipe 5 is in close contact with a strainer hole 6 formed in the lower part of the self-hardening mold 1, and the other end is connected to a non-disappearing spout pipe 7 such as a ceramic pipe spout pipe. There is. Reference numeral 11 is a sprue cup set on the upper end of the non-disappearing sprue pipe 7, and 12 is a feeder cup set on the upper end of the self-hardening mold 1.
A decompression wire netting pipe 8 is provided in the frame 3, and a film 9 for decompression sealing is set on the surface of the dry sand 4 by being pressed by a film protection lid 10. The decompression of is surely performed.

【0009】このようにセットを完了した後、枠3内を
減圧用金網パイプ8によって減圧するとともに、湯口カ
ップ11の上部から図3のように溶湯を注湯する。溶湯は
非消失性湯口管7を介して消失性湯口管5に達し、これ
を消失させながらストレーナホール6から自硬性鋳型1
の型内空間に鋳込まれる。
After the setting is completed in this way, the inside of the frame 3 is depressurized by the depressurizing wire netting pipe 8 and the molten metal is poured from the upper part of the sprue cup 11 as shown in FIG. The molten metal reaches the disappearing spout pipe 5 through the non-disappearing spout pipe 7, and the self-hardening mold 1 is discharged from the strainer hole 6 while disappearing the spout.
It is cast into the mold space.

【0010】このとき消失性湯口管5から少量のスス等
が発生するが、本発明で用いられる消失性湯口管5の発
泡性樹脂の量は従来のフルモールド鋳造法で用いられる
発泡性樹脂の量の1/10〜1/20と非常に少ないためにスス
等の発生量はごく微量であり、減圧用金網パイプ8から
-500mmHg程度の真空で吸引されて外部へ排出される。ま
た残渣、ドロス等は小断面積のストレーナホール6によ
り止められ、型内空間への流入が防止される。このた
め、本発明によれば従来のフルモールド鋳造法で見られ
たような未消失残渣による品質不良を防止することがで
き、低炭素鋼やステンレス鋳鋼に用いても加炭現象を生
ずることがない。
At this time, a small amount of soot or the like is generated from the disappearing spout pipe 5, but the amount of the foaming resin of the disappearing spout pipe 5 used in the present invention is the same as that of the foaming resin used in the conventional full mold casting method. The amount of soot and so on is extremely small because it is 1/10 to 1/20 of the amount.
-Suctioned in a vacuum of about 500 mmHg and discharged to the outside. Further, the residue, dross, etc. are stopped by the strainer hole 6 having a small cross-sectional area, and the inflow into the space inside the mold is prevented. Therefore, according to the present invention, it is possible to prevent quality defects due to undisappeared residues as seen in the conventional full mold casting method, and even when used for low carbon steel or stainless cast steel, a carburization phenomenon may occur. Absent.

【0011】またこの自硬性鋳型1は十分な強度を持つ
ので、実施例のような長尺で大型の鋳造品でも変形・歪
を生ずることがない。更に、本発明では枠3内を減圧し
つつ注湯するため、従来のシェルモールド法のような溶
湯の凝固過程において生ずる外部引け巣や気泡等を防止
するための大きな押湯溜、揚がり等を設ける必要がな
く、むだ湯を大幅に削減することができる。なお、大量
生産のために消失性湯口管5へ消失性模型からなる堰を
多数接続して同時に多数の製品を鋳込むことも可能であ
るから、中型、大型製品においても歩留りの良い鋳造が
可能である。
Further, since the self-hardening mold 1 has sufficient strength, it does not cause deformation or distortion even in a long and large cast product as in the embodiment. Further, in the present invention, the inside of the frame 3 is depressurized while pouring the molten metal, so that a large riser pool, frying, etc. for preventing external shrinkage cavities, bubbles and the like which are generated in the solidification process of the molten metal as in the conventional shell molding method. There is no need to provide it, and waste water can be significantly reduced. For mass production, it is possible to connect many weirs made of fusible models to the fusible sprue pipe 5 and cast many products at the same time. Therefore, it is possible to cast with good yield even for medium-sized and large-sized products. Is.

【0012】このようにして鋳造が完了したら、枠3内
を大気圧に戻して乾燥砂4を流動化させ、自硬性鋳型1
と鋳造品を取り出す。このとき消失性湯口管5は消失し
ているために非消失性湯口管7と自硬性鋳型1とは分離
されており、鋳造後の後処理工程に手数を要しない。
When the casting is completed in this way, the inside of the frame 3 is returned to atmospheric pressure to fluidize the dry sand 4, and the self-hardening mold 1
And take out the casting. At this time, since the disappearing sprue pipe 5 has disappeared, the non-disappearing sprue pipe 7 and the self-hardening mold 1 are separated, and the post-treatment process after casting does not require any trouble.

【0013】[0013]

【発明の効果】以上に説明したように、本発明の減圧シ
ェルモールド鋳造法によれば、小物から大物までスス等
の不純物混入や変形・歪のない精密鋳造が可能である。
また本発明によれば、多くのむだ湯を生ずることなく外
部引け巣や気泡等を防止することができ、また鋳造後の
後処理工程を削減することもできる。このように本発明
は従来のシェルモールド鋳造法と減圧フルモールド鋳造
法の長所を巧みに組合せることにより、安定した大量鋳
造を可能としたものであり、従来の問題点を解決した鋳
造法として、産業の発展に寄与するところは極めて大き
いものである。
As described above, according to the vacuum shell mold casting method of the present invention, it is possible to perform precision casting from small items to large items without inclusion of impurities such as soot and deformation / distortion.
Further, according to the present invention, it is possible to prevent external shrinkage cavities, air bubbles, etc. without producing much waste water, and it is also possible to reduce the post-treatment process after casting. Thus, the present invention enables stable mass casting by skillfully combining the advantages of the conventional shell mold casting method and reduced pressure full mold casting method, and as a casting method that solves the conventional problems. However, the area that contributes to the development of the industry is extremely large.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の実施例に用いられる自硬性鋳型の断面
図である。
FIG. 1 is a cross-sectional view of a self-hardening mold used in an example of the present invention.

【図2】本発明の実施例の工程を示す断面図である。FIG. 2 is a cross-sectional view showing a process of an example of the present invention.

【図3】本発明の実施例の工程を示す断面図である。FIG. 3 is a cross-sectional view showing a process of an example of the present invention.

【符号の説明】[Explanation of symbols]

1 自硬性鋳型 3 枠 5 消失性湯口管 7 非消失性湯口管 1 Self-hardening mold 3 Frame 5 Disappearing sprue pipe 7 Non-disappearing sprue pipe

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 減圧可能な枠内に、シェルモールド・フ
ラン樹脂又はCO2砂からなる自硬性鋳型を埋設するとと
もに、発泡性樹脂からなる消失性湯口管によってこの自
硬性鋳型の型内空間と非消失性湯口管とを接続し、枠内
を減圧しながら溶湯を注湯することを特徴とする減圧シ
ェルモールド鋳造法。
1. A self-hardening mold made of shell mold furan resin or CO 2 sand is embedded in a depressurizable frame, and a self-hardening mold of the self-hardening mold is formed by a fusible sprue tube made of foaming resin. A reduced pressure shell mold casting method, characterized in that the molten metal is poured while connecting the non-disappearing sprue pipe and depressurizing the inside of the frame.
JP5015138A 1993-02-02 1993-02-02 Vacuum shell mold casting method Expired - Fee Related JPH0818122B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5015138A JPH0818122B2 (en) 1993-02-02 1993-02-02 Vacuum shell mold casting method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5015138A JPH0818122B2 (en) 1993-02-02 1993-02-02 Vacuum shell mold casting method

Publications (2)

Publication Number Publication Date
JPH06226422A true JPH06226422A (en) 1994-08-16
JPH0818122B2 JPH0818122B2 (en) 1996-02-28

Family

ID=11880464

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5015138A Expired - Fee Related JPH0818122B2 (en) 1993-02-02 1993-02-02 Vacuum shell mold casting method

Country Status (1)

Country Link
JP (1) JPH0818122B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6209616B1 (en) * 1997-06-20 2001-04-03 Richard F. Polich Vacuum-assisted, gravity-fed casting apparatus and method
US6886621B1 (en) * 2002-08-29 2005-05-03 Brunswick Corp. Sprue for a lost foam casting system for biasing a directional fill rate from a bottom portion of a metal casting
EP1375029A3 (en) * 2002-04-25 2005-08-31 General Motors Corporation Lost foam casting apparatus for reducing porosity and inclusions in metal castings
US20120097357A1 (en) * 2009-07-31 2012-04-26 Muneyoshi Terashima Casting unit and casting method
KR101523875B1 (en) * 2014-02-24 2015-07-15 (주)씨엠캐스팅테크놀러지 Decompression casting apparatus
CN109226686A (en) * 2018-11-29 2019-01-18 芜湖新兴新材料产业园有限公司 The method of casting scab is prevented in lost foam casting process

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102225462A (en) * 2011-02-23 2011-10-26 谭哲豪 Vacuum casting method for sealing feed port by adopting foam plastic
CN103920852B (en) * 2014-04-30 2015-09-02 三明市毅君机械铸造有限公司 A kind of precision casting process of large foundry goods

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63281757A (en) * 1987-05-14 1988-11-18 Tsuneo Yamashita Reduced pressure casting method using lost form pattern
JPH04270024A (en) * 1990-09-06 1992-09-25 Hitchiner Mfg Co Inc Anti-gravity type injection mold method and device using thinwall shell mold supported by granular material

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63281757A (en) * 1987-05-14 1988-11-18 Tsuneo Yamashita Reduced pressure casting method using lost form pattern
JPH04270024A (en) * 1990-09-06 1992-09-25 Hitchiner Mfg Co Inc Anti-gravity type injection mold method and device using thinwall shell mold supported by granular material

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6209616B1 (en) * 1997-06-20 2001-04-03 Richard F. Polich Vacuum-assisted, gravity-fed casting apparatus and method
EP1375029A3 (en) * 2002-04-25 2005-08-31 General Motors Corporation Lost foam casting apparatus for reducing porosity and inclusions in metal castings
US6886621B1 (en) * 2002-08-29 2005-05-03 Brunswick Corp. Sprue for a lost foam casting system for biasing a directional fill rate from a bottom portion of a metal casting
US20120097357A1 (en) * 2009-07-31 2012-04-26 Muneyoshi Terashima Casting unit and casting method
CN102470424A (en) * 2009-07-31 2012-05-23 森川产业株式会社 Casting unit and casting method
KR101523875B1 (en) * 2014-02-24 2015-07-15 (주)씨엠캐스팅테크놀러지 Decompression casting apparatus
CN109226686A (en) * 2018-11-29 2019-01-18 芜湖新兴新材料产业园有限公司 The method of casting scab is prevented in lost foam casting process

Also Published As

Publication number Publication date
JPH0818122B2 (en) 1996-02-28

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