JPH0832353B2 - Hollow core molding method - Google Patents
Hollow core molding methodInfo
- Publication number
- JPH0832353B2 JPH0832353B2 JP18065590A JP18065590A JPH0832353B2 JP H0832353 B2 JPH0832353 B2 JP H0832353B2 JP 18065590 A JP18065590 A JP 18065590A JP 18065590 A JP18065590 A JP 18065590A JP H0832353 B2 JPH0832353 B2 JP H0832353B2
- Authority
- JP
- Japan
- Prior art keywords
- core
- hollow
- hollow core
- sand
- molding method
- 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
Landscapes
- 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、中空部を有する鋳物用中子に適用される中
空中子成形法に関し、特に、コールドボックス法や自硬
性鋳型などを使用した中空中子の成形に適した方法に関
する。Description: TECHNICAL FIELD The present invention relates to a hollow core molding method applied to a casting core having a hollow portion, and particularly to a hollow core molding method using a cold box method or a self-hardening mold. A method suitable for molding a child.
従来の技術 鋳物に中空部を作る目的で主型の所定の位置に配設さ
れる中子は、中子自身の軽量化や鋳込時に発生するガス
対策などを考慮して、中空形状とするのが一般的であ
る。2. Description of the Related Art Cores that are placed at predetermined positions in the main mold for the purpose of making hollow parts in castings are made hollow in consideration of weight reduction of the core itself and measures against gas generated during casting. Is common.
そこで、従来の中空中子成形法を第４図及び第５図に
基づいて簡単に説明する。第４図はマンドレル（入子中
子）を使用した成形法を示しており、中子型の所定の位
置にマンドレル９をセットして砂づめ造型後、中空中子
１からマンドレル９を引き抜いて中空部２を形成するも
のである。また、第５図は、シェルモールド法による中
空中子成形法を示しており、加熱した中子型５′にシェ
ル砂を吹き込み、一定時間経過後に中子型を反転して内
部に残った未硬化部分の砂10を排出することにより、こ
のシェル砂の存在した部分が中空中子１の中空部２とな
るものである。Therefore, the conventional hollow core molding method will be briefly described with reference to FIGS. 4 and 5. FIG. 4 shows a molding method using a mandrel (nesting core). The mandrel 9 is set at a predetermined position of the core mold, sand-molded, and then the mandrel 9 is pulled out from the hollow core 1. The hollow portion 2 is formed. Further, FIG. 5 shows a hollow core molding method by a shell molding method, in which shell sand is blown into a heated core mold 5 ', and after a lapse of a certain time, the core mold is inverted to leave the inner core. By discharging the sand 10 of the hardened portion, the portion where the shell sand was present becomes the hollow portion 2 of the hollow core 1.
発明が解決しようとする課題 ところで、前述した従来の中空中子成形法は、いずれ
も次のような問題点を有している。DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, each of the conventional hollow core molding methods described above has the following problems.
すなわち、マンドレルを引き抜いて中空部を形成する
第１従来例の場合は、これを適用できる中子の形状に制
限を受け、たとえば第１図に示す如く、マンドレルの抜
き穴を十分に確保できない形状や複雑な形状のものに適
用するのは困難であった。このため、第１従来例の中空
中子成形法を適用できない場合には、第２従来例に示し
た如く、シェルモールド法による反転落下方式で中空中
子を造形していた。しかしながら、この反転落下方式に
よる中空中子の造形は、コールドボックス法や自硬性鋳
型などを使用した場合には適用することができなかっ
た。That is, in the case of the first conventional example in which the mandrel is pulled out to form the hollow portion, the shape of the core to which this can be applied is limited, and for example, as shown in FIG. It was difficult to apply it to those with complicated shapes. For this reason, when the hollow core molding method of the first conventional example cannot be applied, the hollow core is molded by the reverse dropping method by the shell mold method as shown in the second conventional example. However, the hollow core molding by the reversal drop method cannot be applied when a cold box method or a self-hardening mold is used.
本発明は、上記の事情に鑑みてなされたもので、その
目的とするところは、中子の形状にとらわれることなく
コールドボックス法や自硬性鋳型を使用して中空中子の
造形ができる中空中子成形法を提供することである。The present invention has been made in view of the above circumstances, and an object thereof is to form a hollow core using the cold box method or a self-hardening mold without being restricted by the shape of the core. It is to provide a child molding method.
課題を解決するための手段 本発明は、前述の課題を解決するもので、中子型の所
定の位置に発泡樹脂製の模型を配設した後砂づめをし、
該砂に含まれる硬化剤中の石油系溶剤と発泡樹脂との反
応によって、前記模型を収縮させて中子の中空部を形成
したことを特徴とする中空中子成形法である。Means for Solving the Problems The present invention is to solve the above-mentioned problems, and after arranging a model made of a foamed resin at a predetermined position of the core mold, sand-stuck,
The hollow core molding method is characterized in that the model is contracted to form a hollow portion of a core by a reaction between a petroleum solvent in a curing agent contained in the sand and a foaming resin.
作用 前述の手段によれば、中空中子の中空部に相当する位
置に発泡樹脂製の模型を配設して砂づめをするので、こ
の砂に含まれている硬化剤中の石油系溶剤と発泡樹脂と
が反応し、発泡樹脂性の模型が収縮して中子に中空部が
形成される。Action According to the above-mentioned means, since the foam resin model is arranged at a position corresponding to the hollow portion of the hollow core for sand filling, the petroleum solvent in the curing agent contained in the sand The foamed resin reacts with each other, and the foamed resin model contracts to form a hollow portion in the core.
実施例 本発明による中空中子成形法の一実施例を第１図ない
し第3c図に基づいて説明する。第１図及び第２図は中空
中子の中空部形成を説明するための断面図、第3a図ない
し第3c図はコールドボックス法による中空中子の造型手
順を示す図である。EXAMPLE An example of the hollow core molding method according to the present invention will be described with reference to FIGS. 1 to 3c. 1 and 2 are cross-sectional views for explaining the formation of the hollow portion of the hollow core, and FIGS. 3a to 3c are views showing the procedure for molding the hollow core by the cold box method.
鋳物に中空部を形成する中子は、軽量化やガス抜き対
策などのため中空形状のものが採用されている。この中
空中子１をコールドボックス法で造型する場合、最初に
中空中子１の中空部２に相当する形状の模型３を、発泡
ポリスチレンや発泡ポリメタクリルなどの発泡樹脂で製
作する。発泡樹脂は非常に軽く（たとえば、発泡ポリス
チレンの比重は0.02〜0.04）、かつ加工性も良好であ
る。次に、製作された発泡樹脂製の模型３を、心金４を
支持部材として中子型５の所定の位置に配設する。この
後、中子型５に砂づめをするが、この砂づめは、吹込式
造型機６を使用してもよいし、あるいは手込め造型でも
よい。なお、コールドボックス法で使用される砂７は、
けい砂に硬化剤（粘結剤）としてフェノールレジンとポ
リイソシアネート（M.D.I.）とが適量加えられて混合さ
れたものである。こうして砂づめが完了した後、模型３
の外周部に造型された中空中子１にトリエチルアミンな
どのアミンガスを吹き込むことにより、該アミンガスが
砂７の硬化剤と反応して中空中子１は瞬間的に硬化す
る。なお、硬化が完了した後には反応の終ったガス及び
未反応のガスを空気により排出し、排気浄化槽８に導い
て浄化する。As a core for forming a hollow portion in a casting, a hollow-shaped core is adopted in order to reduce the weight and prevent degassing. When molding the hollow core 1 by the cold box method, first, the model 3 having a shape corresponding to the hollow portion 2 of the hollow core 1 is manufactured from a foamed resin such as expanded polystyrene or expanded polymethacryl. The foamed resin is very light (for example, the specific gravity of expanded polystyrene is 0.02 to 0.04) and has good processability. Next, the produced foamed resin model 3 is arranged at a predetermined position of the core mold 5 with the mandrel 4 as a supporting member. After that, the core mold 5 is sand-filled, and this sand-filling may be performed by using a blow-in molding machine 6 or by hand-filling molding. The sand 7 used in the cold box method is
Phenolic resin and a polyisocyanate (MDI) as a curing agent (binding agent) are added to silica sand in appropriate amounts and mixed. After sanding is completed in this way, model 3
By blowing an amine gas such as triethylamine into the hollow core 1 molded on the outer peripheral portion of the hollow core 1, the amine core reacts with the curing agent of the sand 7 and the hollow core 1 is instantaneously cured. After the curing is completed, the reacted gas and the unreacted gas are discharged by air and guided to the exhaust gas purification tank 8 for purification.
ところで、発泡ポリスチレンなどの発泡樹脂は、コー
ルドボックス法で使用される砂に含まれている硬化剤中
の石油系溶剤と反応して収縮する性質を有している。こ
のため、中子型５に砂づめがなされると、発泡樹脂製の
模型３は砂７と接触し、該砂に含まれている石油系溶剤
との反応によってゆっくりと収縮する。そして、第１図
に示す如く、模型３の外周で瞬間的に硬化した砂７に囲
まれている模型３の収縮が完了すると、第２図に示す如
く、模型３の存在した位置に中空部２が形成される。こ
の後、心金４を抜き取って中空中子１の造型が完了す
る。この時、収縮した模型３′が中空部に残されるが、
中空中子１の軽量化やガス抜きに支障をきたすことはな
い。また、模型３の収縮を促進したい場合には、模型３
と一体の中空中子１を80〜120℃程度に熱すると効果的
である。By the way, a foamed resin such as expanded polystyrene has a property of shrinking by reacting with a petroleum solvent in a curing agent contained in sand used in the cold box method. Therefore, when the core mold 5 is sand-filled, the foamed resin model 3 comes into contact with the sand 7 and slowly contracts due to the reaction with the petroleum solvent contained in the sand 7. Then, as shown in FIG. 1, when the shrinkage of the model 3 surrounded by the sand 7 that has been momentarily hardened on the outer periphery of the model 3 is completed, as shown in FIG. 2 is formed. After this, the mandrel 4 is removed to complete the molding of the hollow core 1. At this time, the contracted model 3'is left in the hollow part,
The hollow core 1 does not hinder the weight reduction and the degassing. If you want to accelerate the contraction of the model 3,
It is effective to heat the hollow core 1 integrated with the above to about 80 to 120 ° C.
上述したような中空中子成形法を採用すると、所望の
形状の中空部に合わせて発泡樹脂製の模型を作り、中子
型内で該模型の外周に吹き込んだ砂を硬化させた後、石
油系溶剤と反応した模型が収縮して中空部を形成するの
で、中空部の形状が複雑な中空中子や、あるいは、マン
ドレルの抜き穴を確保できないような形状の中空中子で
あっても、中子や中空部の形状にとらわれることなく、
コールドボックス法による中子成形を容易に実施するこ
とができる。When the hollow core molding method as described above is adopted, a model made of foamed resin is made in accordance with the hollow part of a desired shape, and after sand blown to the outer periphery of the model is cured in the core mold, oil Since the model that has reacted with the system solvent shrinks to form a hollow portion, the hollow core has a complicated shape of the hollow portion, or even a hollow core having a shape such that the mandrel holes cannot be secured. Regardless of the shape of the core or hollow part,
Core molding by the cold box method can be easily carried out.
なお、上記実施例は、本発明による中空中子成形法を
コールドボックス法に適用した場合を示して説明した
が、本発明は、コールドボックス法の他にも、石油系溶
剤を含んだ砂を使用する自硬性鋳型などにも適用可能な
ことは言うまでもない。Although the above examples have been described by showing the case where the hollow core molding method according to the present invention is applied to the cold box method, the present invention, in addition to the cold box method, sand containing a petroleum solvent is used. It goes without saying that it can also be applied to the self-hardening mold used.
発明の効果 前述した本発明によれば、コールドボックス法や自硬
性鋳型で所望の形状の中空部を形成できるようになり、
成形可能な中空中子の形状及びその成形法選択の自由度
が増す。従って、所望の形状の中空中子を、その形状、
精度及びコストなどの優劣を考慮し、最適の成形法を採
用して造形することができるようになる。Effects of the Invention According to the present invention described above, it becomes possible to form a hollow portion having a desired shape by a cold box method or a self-hardening mold,
The degree of freedom in selecting the shape of the moldable hollow core and its molding method is increased. Therefore, the hollow core of the desired shape,
In consideration of advantages and disadvantages such as accuracy and cost, it becomes possible to adopt an optimum molding method for modeling.
図面は本発明による中空中子成形法の一実施例を示すも
ので、第１図及び第２図は中空中子の中空部形成を説明
するための図であって、第１図は中空部形成前の断面
図、第２図は中空部形成後の断面図、第3a図ないし第3c
図はコールドボックス法による中空中子の造型手順を示
す図、第４図及び第５図は従来例を示す図である。 １……中空中子、２……中空部、３……模型、４……心
金、５……中空型、６……吸込式造型機、７……砂、８
……排気浄化槽、９……マンドレル。The drawings show an embodiment of the hollow core molding method according to the present invention. FIGS. 1 and 2 are views for explaining the formation of the hollow portion of the hollow core, and FIG. 1 is the hollow portion. Sectional view before formation, FIG. 2 is sectional view after formation of the hollow portion, FIGS. 3a to 3c
The figure shows a procedure for molding a hollow core by the cold box method, and FIGS. 4 and 5 show conventional examples. 1 ... Hollow core, 2 ... Hollow part, 3 ... Model, 4 ... Mandrel, 5 ... Hollow mold, 6 ... Suction molding machine, 7 ... Sand, 8
…… Exhaust gas septic tank, 9 …… Mandrel.
Claims (1)
配設した後砂づめをし、該砂に含まれる硬化剤中の石油
系溶剤と発泡樹脂との反応によって、前記模型を収縮さ
せて中子の中空部を形成したことを特徴とする中空中子
成形法。1. A model made of foamed resin is arranged at a predetermined position of a core mold, and then sand-filled, and the model is produced by reacting a petroleum solvent in a curing agent contained in the sand with a foamed resin. A hollow core molding method, characterized in that the hollow core of the core is formed by shrinking the core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18065590A JPH0832353B2 (en) | 1990-07-10 | 1990-07-10 | Hollow core molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18065590A JPH0832353B2 (en) | 1990-07-10 | 1990-07-10 | Hollow core molding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0471752A JPH0471752A (en) | 1992-03-06 |
| JPH0832353B2 true JPH0832353B2 (en) | 1996-03-29 |
Family
ID=16087001
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18065590A Expired - Lifetime JPH0832353B2 (en) | 1990-07-10 | 1990-07-10 | Hollow core molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0832353B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104190872A (en) * | 2014-09-12 | 2014-12-10 | 苏州明志科技有限公司 | Material-saving sand core and sand core making method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8091608B2 (en) * | 2009-05-15 | 2012-01-10 | GM Global Technology Operations LLC | Method of forming a hollow sand core |
-
1990
- 1990-07-10 JP JP18065590A patent/JPH0832353B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104190872A (en) * | 2014-09-12 | 2014-12-10 | 苏州明志科技有限公司 | Material-saving sand core and sand core making method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0471752A (en) | 1992-03-06 |
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