JPH07178713A - Preparation of ceramic and porous mold therefor - Google Patents
Preparation of ceramic and porous mold thereforInfo
- Publication number
- JPH07178713A JPH07178713A JP32478293A JP32478293A JPH07178713A JP H07178713 A JPH07178713 A JP H07178713A JP 32478293 A JP32478293 A JP 32478293A JP 32478293 A JP32478293 A JP 32478293A JP H07178713 A JPH07178713 A JP H07178713A
- Authority
- JP
- Japan
- Prior art keywords
- mold
- die
- water absorption
- absorption rate
- porous
- 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
Landscapes
- Producing Shaped Articles From Materials (AREA)
- Moulds, Cores, Or Mandrels (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、セラミックス、特に頭
頂部が閉止された小径の中空円筒形の中心コア部とこの
中心コア部から半径方向に延長する大径の笠部とを有す
る懸垂碍子および同様のセラミックスの製造方法および
これに用いる多孔質成形型に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceramics, in particular, a suspension insulator having a small-diameter hollow-cylindrical central core portion having a closed top portion and a large-diameter cap portion extending radially from the central core portion. And a method for producing the same ceramics and a porous mold used for the same.
【０００２】[0002]
【従来の技術】従来、上述したように、頭頂部が閉止さ
れた小径の中空円筒形の中心コア部とこのコア部から半
径方向に延長した大形笠部とを有する懸垂碍子等のセラ
ミックス（窯業製品）の製造に際しては、成形すべきセ
ラミックスの外形、すなわち小径中心コア部および大形
笠部の外形にそれぞれ対応する形状の成形型表面を有す
る多孔質の型中央部および型外周部を具える多孔質成形
型を用い、成形型表面に可塑性杯土を押しつけ、例え
ば、成形型表面に沿って成形型内に埋設した多孔チュー
ブを経て、成形型表面全体に負圧を作用させて可塑性杯
土を成形型表面に密着させて正確な形状に成形し、成形
後、成形型表面から加圧空気を噴出させて成形体を離型
して成形型から取出している。2. Description of the Related Art Conventionally, as described above, ceramics such as a suspension insulator having a small-diameter hollow cylindrical central core portion with a closed top portion and a large cap portion extending radially from the core portion ( In the production of ceramic products, a porous mold center and mold outer peripheral part having a mold surface of a shape corresponding to the outer shape of the ceramic to be molded, that is, the outer shape of the small-diameter central core portion and the large cap portion, respectively. Using a porous forming mold, press the plastic clay soil on the surface of the forming mold, and, for example, through a porous tube embedded in the forming mold along the surface of the forming mold, apply a negative pressure to the entire surface of the forming mold to form a plastic cup. The soil is brought into close contact with the surface of the molding die to be molded into an accurate shape, and after molding, pressurized air is ejected from the surface of the molding die to release the molded body from the molding die.
【０００３】しかしながら、上述した従来方法では、成
形型の気孔が多いことによる型強度の低下により成形時
の荷重により生じる型割れ、離型時のエアーブローの空
気圧による成形体表面の変形、エアーブローの空気圧不
足による離型不可能、成形体の小径中心コア部と大径笠
部との境界部分での破断、成形体の頭頂部の浮き上がり
による変形等の問題が生じている。However, in the above-mentioned conventional method, the mold strength is lowered due to the large number of pores in the mold, the mold is cracked by the load during molding, the surface of the molded product is deformed by the air pressure of the air blow at the time of mold release, and the air blow is performed. Since there is insufficient air pressure, the mold release is impossible, breakage occurs at the boundary between the small-diameter central core portion and the large-diameter cap portion, and the top of the molded body is lifted and deformed.
【０００４】[0004]
【発明が解決しようとする課題】本発明の目的は上述し
た問題を解決するよう改良した懸垂碍子その他のセラミ
ックスの製造方法を提供しようとするものである。SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method for producing suspended insulators and other ceramics which solves the above-mentioned problems.
【０００５】本発明の他の目的は、本発明方法を実施す
るために用いる多孔質成形型を提供しようとするもので
ある。Another object of the present invention is to provide a porous mold used for carrying out the method of the present invention.
【０００６】[0006]
【課題を解決するための手段】本発明の第１の要旨によ
れば、頭頂部が閉止された小径の中空円筒形の中心コア
部とこのコア部から半径方向に延長した大径笠部とを有
する懸垂碍子その他同様のセラミックスを前記中心コア
部および大径笠部の外形にそれぞれ対応する形状の成形
型表面を有する型中央部および型外周部を含む型本体を
具える多孔質成形型の成形型表面に可塑性杯土を押し付
けて成形した後、成形型表面から気体を噴出させて成形
体を離型して成形型から取出す懸垂碍子その他同様のセ
ラミックスを製造する方法において、前記型外周部の型
表面側部分の吸水率が前記型中央部の吸水率より高い多
孔質成形型を用いる。According to the first aspect of the present invention, a small-diameter hollow cylindrical central core portion having a closed top portion and a large-diameter cap portion extending radially from the core portion. And a similar ceramics of a porous molding die including a die body including a die central portion and a die outer peripheral portion having a die surface having a shape corresponding to the outer shapes of the central core portion and the large diameter cap portion, respectively. In the method for producing a suspension insulator or other similar ceramics, in which plastic clay is pressed against the surface of a molding die to mold, and then a gas is ejected from the surface of the molding die to separate the molded body from the molding die and the same ceramics is produced. A porous molding die having a higher water absorption rate on the surface side of the mold than the water absorption rate on the center part of the mold is used.
【０００７】本発明の第２の要旨によれば、頭頂部が閉
止された小径の中空円筒形の中心コア部とこのコア部か
ら半径方向に延長した大径笠部とを有する懸垂碍子その
他同様のセラミックスの外形に対応する形状の成形型表
面を有する型中央部および型外周部を含む型本体を具え
る多孔質成形型において、前記型外周部の型表面側部分
の吸水率が前記型中央部の吸水率より高いことを特徴と
する。According to the second aspect of the present invention, a suspension insulator having a small-diameter hollow cylindrical central core portion having a closed top portion and a large-diameter cap portion extending radially from the core portion, and the like. In a porous mold having a mold body having a mold center portion and a mold outer peripheral portion having a shape corresponding to the outer shape of the ceramics, the water absorption rate of the mold surface side portion of the mold outer peripheral portion is the center of the mold. It is characterized in that it has a higher water absorption than the other parts.
【０００８】本発明によれば、前記型外周部の型表面側
部分の吸水率を好ましくは２０〜３０％とし、前記型中
央部の閉止頭頂部分の吸水率を好ましくは１０〜２０％
とする。According to the present invention, the water absorption rate of the mold surface side portion of the mold outer peripheral portion is preferably 20 to 30%, and the water absorption rate of the closed top portion of the mold central portion is preferably 10 to 20%.
And
【０００９】また、本発明によれば、前記型外周部の型
表面側部分の吸水率Ａと前記型中央部の閉止頭頂部分の
吸水率Ｂとの差Ａ−Ｂを５〜２０％とするのがよい。Further, according to the present invention, the difference A-B between the water absorption rate A at the die surface side portion of the die outer peripheral portion and the water absorption rate B at the closed top portion of the die central portion is set to 5 to 20%. Is good.
【００１０】また、本発明によれば、多孔質成形型の型
中央部および型外周部を含む型本体を石膏、合成樹脂、
多孔質セラミックス、焼結金属およびこれらの混合物の
ような多孔質体で形成することができるが、なかでも石
膏は安価で、補修が容易に可能であるので好ましい。Further, according to the present invention, a mold body including a mold central portion and a mold outer peripheral portion of a porous molding die is made of gypsum, synthetic resin,
It can be formed of a porous material such as porous ceramics, sintered metal, or a mixture thereof, but among them, gypsum is preferable because it is inexpensive and can be easily repaired.
【００１１】合成樹脂材料としては、エポキシ、ウレタ
ン、フェノール、アクリル、シリコンおよび同様の樹脂
が、セラミック材料としては、ムライト、コージェライ
ト、アルミナ、ジルコン、ガラスおよび同様の材料が、
焼結金属材料としては、鉄、銅、ニッケル、ステンレス
鋼、アルミニウム、黄銅および同様の材料が用いられ
る。Synthetic resin materials include epoxy, urethane, phenol, acrylic, silicone and similar resins, and ceramic materials include mullite, cordierite, alumina, zircon, glass and similar materials.
As the sintered metal material, iron, copper, nickel, stainless steel, aluminum, brass and similar materials are used.
【００１２】また、本発明によれば、多孔質成形型の型
中央部の頭頂部分および型外周部の型表面側部分の吸水
率を制御する手段として、多孔質成形型の気孔率を局部
的に変えるのがよい。Further, according to the present invention, the porosity of the porous molding die is locally controlled as a means for controlling the water absorption rate at the top of the center of the porous molding die and the mold surface side portion of the outer periphery of the die. It is better to change to.
【００１３】また、本発明によれば、多孔質成形型の頭
頂部分および型表面側部分の吸水率を相違させる手段と
して、多孔チューブを型外周部の成形型表面のみに沿っ
て型本体内に埋設するのがよい。Further, according to the present invention, as a means for differentiating the water absorption rate between the crown portion and the mold surface side portion of the porous molding die, a porous tube is provided in the mold body along only the molding surface at the outer peripheral portion of the mold. It is better to bury it.
【００１４】[0014]
【作用】本発明によれば、上述したように、型外周部の
型表面側部分の吸水率が型中央部の頭頂部分の吸水率よ
り高い多孔質成形型を用いることによって成形体の離型
時に大径笠部に対して中心コア部に対するよりも多量の
気体が噴出され、これによって、笠部が中心コア部より
先に離型され、これに追従して中心コア部が離型され、
この結果として、成形型から成形体を変形または損傷す
ることなく容易に取出すことができる。According to the present invention, as described above, by using a porous molding die in which the water absorption rate of the die surface side portion of the die outer peripheral portion is higher than the water absorption rate of the crown portion of the die central portion, the molded article is released from the mold. At times, a larger amount of gas is ejected to the large-diameter cap portion than to the central core portion, whereby the cap portion is released before the central core portion, and the central core portion is released accordingly.
As a result, the molded body can be easily taken out from the molding die without being deformed or damaged.
【００１５】[0015]
【実施例】図４は本発明方法により製造されるセラミッ
クスの一例を示し、図示の例は頭頂部１５が閉止された
小径の中空円筒形の中心コア部１６と、この中心コア部
１６から半径方向に延長する大径笠部１７とを有する典
型的懸垂碍子を示す。FIG. 4 shows an example of ceramics produced by the method of the present invention. In the example shown in the figure, a small-diameter hollow cylindrical central core portion 16 with a crown 15 closed, and a radius from the central core portion 16 are shown. 2 illustrates a typical suspension insulator with a large diameter cap 17 extending in the direction.
【００１６】上述した図４に示す懸垂碍子の製造に際し
ては、図１に示す多孔質成形型の成形型表面に可塑性杯
土を押しつけ、成形型表面に負圧を作用させて可塑性杯
土を成形型表面に密着させて成形し、成形後、成形型表
面から加圧空気を噴出させて成形体を離型して成形型か
ら取出す。In the production of the suspension insulator shown in FIG. 4 described above, the plastic clay is pressed against the surface of the mold of the porous mold shown in FIG. 1 and a negative pressure is applied to the surface of the mold to form the plastic clay. Molding is performed in close contact with the mold surface, and after molding, pressurized air is jetted from the mold surface to release the molded body and remove it from the molding die.
【００１７】図１は図４に示した懸垂碍子を成形するた
めに用いられる多孔質石膏型を示し、この多孔質石膏型
は、アルミニウム等の金属で造られた型枠１と、この型
枠１の内面上に流し込み成形された連続気孔を有する多
孔質石膏型本体２とを具え、この型本体２は成形すべき
懸垂碍子の大型笠部１７および小径中心コア部１６の外
形にそれぞれ対応する形状の型表面３および６を有する
多孔質の型外周部型表面側部分７と型中央部８とを有す
る。FIG. 1 shows a porous gypsum mold used to mold the suspended insulator shown in FIG. 4, and this porous gypsum mold is a mold 1 made of metal such as aluminum, and this mold. 1 and a porous gypsum mold body 2 having continuous pores formed on the inner surface of the mold 1. The mold body 2 corresponds to the outer shapes of the large cap portion 17 and the small diameter central core portion 16 of the suspension insulator to be molded, respectively. It has a porous mold outer peripheral portion mold surface side portion 7 having a shaped mold surface 3 and a mold central portion 8.
【００１８】図示の例では型外周部の型表面側部分７の
型表面３に沿ってのみ、例えば、型表面３から約２５ｍ
ｍ離間した位置で多孔質石膏型本体２の内部に多孔チュ
ーブ４が埋設されている。多孔チューブ４としては、例
えば、サイジングチューブと呼ばれるガラス繊維チュー
ブが用いられる。In the illustrated example, only along the mold surface 3 of the mold surface side portion 7 of the mold outer peripheral portion, for example, about 25 m from the mold surface 3.
A porous tube 4 is embedded inside the porous gypsum mold body 2 at a position separated by m. As the porous tube 4, for example, a glass fiber tube called a sizing tube is used.
【００１９】多孔チューブ４は図２に示すように扇風機
のガードのような形状の鉄製の芯材５の外側にスパイラ
ル状に巻付けられており、その両端はビニールチューブ
１０に接続されて型枠１の下端部の接続金具１１に達し
ており、懸垂碍子の成形に際し、接続金具１１を真空源
（図示せず）に接続することによって、多孔チューブ４
を経て型表面３および６に負圧を作用させて可塑性杯土
を型表面３および６に密着させて正確な形状に成形し、
また成形後、接続金具１１を圧縮空気源（図示せず）に
接続することによって、多孔チューブ４を経て型表面３
および６から加圧空気を噴出させて型から成形体を離型
し得るよう構成されている。なお、９は型中央部からの
空気の噴出を防止するため型枠１の下端部の内側に設け
られた非通気性石膏である。As shown in FIG. 2, the perforated tube 4 is spirally wound around an iron core material 5 shaped like a fan guard, and both ends thereof are connected to a vinyl tube 10 to form a frame. 1 reaches the connecting fitting 11 at the lower end of the porous tube 4 by connecting the connecting fitting 11 to a vacuum source (not shown) at the time of forming the suspension insulator.
Negative pressure is applied to the mold surfaces 3 and 6 to bring the plastic clay into close contact with the mold surfaces 3 and 6 to form an accurate shape,
After molding, the connection fitting 11 is connected to a compressed air source (not shown) so that the mold surface 3 passes through the porous tube 4.
And 6 to eject the pressurized air to release the molded body from the mold. In addition, 9 is a non-air-permeable gypsum provided inside the lower end of the mold 1 to prevent air from being blown out from the center of the mold.
【００２０】上述した図示の石膏型では、多孔チューブ
４が型外周部の型表面側部分７の成形型表面３だけに沿
ってこの表面から２５mm離間した位置で多孔質型本体２
の石膏内部に埋設されている。これがため、吸水率を測
定した結果、型外周部７の型表面側部分７で２０〜３０
％の吸水率が、また型中央部８の頭頂部分８ａで１０〜
２０％の吸水率が測定される。しかもこの吸水率を型外
周部の型表面側部分７において型中央部８より大きくす
ることができ、型表面側部分７の吸水率Ａと型中央部の
頭頂部分８ａの吸水率Ｂとの差Ａ−Ｂを５〜２０％とす
ることができる。In the plaster mold shown in the above, the porous mold body 2 has the porous tube 4 along the mold surface 3 of the mold surface side portion 7 of the mold periphery along a distance of 25 mm from this surface.
It is buried inside the plaster. Therefore, as a result of measuring the water absorption rate, the mold outer peripheral portion 7 has a mold surface side portion 7 of 20 to 30.
% Water absorption is 10 to 10 at the crown portion 8a of the mold central portion 8
A water absorption of 20% is measured. Moreover, this water absorption rate can be made larger in the die surface side portion 7 of the die outer peripheral portion than in the die center portion 8, and the difference between the water absorption rate A of the die surface side portion 7 and the water absorption rate B of the crown portion 8a of the die center portion. AB can be 5 to 20%.
【００２１】上述した型表面側部分７の吸水率が３０％
より大きくなると、気孔が多くなるため型外周部の型強
度が低下し、成形時の荷重によって型割れが生じ、ま
た、離型時の噴出空気量が多くなり過ぎる。このため噴
出空気によって成形体が図５にａおよびｂで示すように
変形される問題がある。これに反し、型表面側部分の吸
水率が２０％より低くなると成形体の離型が不可能とな
り、強制的に離型させようとすると図５にＣで示すよう
に成形体の首部が破断する問題が生じる。The water absorption rate of the mold surface side portion 7 is 30%.
If it becomes larger, the number of pores increases and the die strength of the outer peripheral portion of the die lowers, the die cracks due to the load during molding, and the amount of air blown out at the time of demolding becomes too large. Therefore, there is a problem that the molded body is deformed by the jet air as shown by a and b in FIG. On the contrary, when the water absorption rate of the mold surface side portion is lower than 20%, it becomes impossible to release the molded product, and when the mold is forcibly released, the neck portion of the molded product is broken as shown by C in FIG. Problem arises.
【００２２】他方、型中央部８の頭頂部分８ａの吸水率
が２０％より大きくなると噴出空気量が大きくなり過ぎ
て、離型時の噴出空気によって図５にｄで示すように成
形体の頭頂部５が浮き上がり変形するという問題が生じ
る。また、頭頂部分の吸水率が１０％より低くなると、
成形体を離型させることが不可能になる問題の発生が多
くなる。On the other hand, when the water absorption rate of the crown portion 8a of the mold central portion 8 is larger than 20%, the amount of ejected air becomes too large, and the ejected air at the time of releasing the mold causes the head of the molded body to move as shown by d in FIG. There arises a problem that the top portion 5 is lifted and deformed. Also, if the water absorption rate of the crown becomes lower than 10%,
There are many problems that make it impossible to release the molded body.
【００２３】また、型外周部の型表面側部分７と型中央
部８の頭頂部分８ａの吸水率の差を５〜２０％にしない
と離型時の圧力バランスが悪く、やはり成形体が変形す
る問題が生じる。Further, unless the difference in water absorption between the mold surface side portion 7 of the mold outer peripheral portion and the crown portion 8a of the mold central portion 8 is set to 5 to 20%, the pressure balance at the time of mold release is poor and the molded body is also deformed. Problem arises.
【００２４】次に上述した多孔質石膏型の製造方法につ
いて図を参照して説明する。Next, a method for manufacturing the above-mentioned porous gypsum mold will be described with reference to the drawings.
【００２５】先ず、図２に示すように鉄製の芯材５の外
側にサイジングチューブよりなる多孔チューブ４をスパ
イラル状に巻付けることにより所定形状を保持させたも
のを作成する。このように形成した多孔チューブ４を製
造すべき懸垂碍子の外表面に対応する外形を有する内型
１２の外表面から所定寸法、例えば２５ｍｍ離した位置
に図３に示すように、スペーサー１３に上に載置して浮
き上がらせた状態でセットする。なお、これに先立ち、
石膏等よりなる内型１２の外表面上には石鹸水のような
離型材を塗布しておき、注型石膏の半硬化状態での離型
性を良くするものとする。次に、アルミニウム製の型枠
１を内型１２および多孔チューブ４の外側にセットす
る。次に多孔チューブ４の端部に接続されたビニールチ
ューブ１０の先端を型枠１外に引き出し、脱気された石
膏２を型枠１と内型１２との間の間隙に注入する。石膏
は多孔チューブ４がセットされた空間内部を下方より順
次埋めて上昇し、石膏の上面が所定位置まで達したとき
に注入を止め、その上に多孔質石膏とは異なる非通気性
石膏９を注入する。First, as shown in FIG. 2, a perforated tube 4 made of a sizing tube is spirally wound around an outer surface of a core material 5 made of iron to prepare a product having a predetermined shape. The perforated tube 4 thus formed has a predetermined size, for example 25 mm, from the outer surface of the inner mold 12 having an outer shape corresponding to the outer surface of the suspension insulator to be manufactured, and is placed on the spacer 13 as shown in FIG. Place it on and set it up in a floating state. Prior to this,
A mold release material such as soap water is applied on the outer surface of the inner mold 12 made of gypsum or the like to improve the mold releasability of the cast gypsum in the semi-cured state. Next, the mold 1 made of aluminum is set outside the inner mold 12 and the perforated tube 4. Next, the tip of the vinyl tube 10 connected to the end of the porous tube 4 is pulled out of the mold 1, and the degassed gypsum 2 is injected into the gap between the mold 1 and the inner mold 12. Gypsum sequentially fills the inside of the space where the porous tube 4 is set from below and rises, and when the top surface of the gypsum reaches a predetermined position, the injection is stopped, and a non-air-permeable gypsum 9 different from the porous gypsum is placed on it. inject.
【００２６】この状態で室温に静置すると石膏は次第に
硬化するので、半硬化状態となったときに内型１２を離
型し、反転し、図１の状態として図示しない空気圧送装
置上にセットし、圧縮空気源（図示せず）を接続金具１
１に接続し、ビニールチューブ１０を経て多孔チューブ
４の内部に圧縮空気を導入する。圧縮空気の導入は、例
えば０．５〜１．０kg／cm2 で１０分程度、１．５〜
２．０kg／cm 2 で５〜１０分程度、最後に、２．５〜
３．０kg／cm2 と３段階に順次に圧力を高めつつ合計で
約３０〜４０分間にわたって行われる。When the gypsum is gradually left at room temperature in this state,
Since it cures, release the inner mold 12 when it becomes a semi-cured state.
Molded and inverted, pneumatic feeding device not shown in the state of FIG.
Set on the table and connect the compressed air source (not shown) to the fitting 1
1 connected, through a vinyl tube 10 and a perforated tube
Compressed air is introduced into No. 4. Introduction of compressed air is an example
For example, 0.5 to 1.0 kg / cm2About 10 minutes, 1.5 ~
2.0 kg / cm 25 to 10 minutes, and finally 2.5 to
3.0 kg / cm2And increasing the pressure sequentially in 3 steps
It is performed for about 30 to 40 minutes.
【００２７】なお、石膏型脱水後期には空気流量を５０
０リットル／分に調整する。この時、型中央部８の型表
面６に油粘土のかたまりを乗せ、これをピストンで３kg
／cm2 の押圧力で押し付け密封する。In the latter stage of the gypsum type dehydration, the air flow rate is 50
Adjust to 0 liters / minute. At this time, put a mass of oil clay on the mold surface 6 of the mold central portion 8 and use a piston to load 3 kg.
Press with a pressing force of / cm 2 and seal.
【００２８】このようにしてサイジングチューブよりな
る多孔チューブ４内に導入された圧縮空気は繊維状の多
孔チューブ４の外周壁から噴出し、半硬化状態の石膏の
内部に分散する。しかし、型中央部および多孔チューブ
４よりも型枠１の側の部分は型枠１によって密閉されて
いるのに対し、型表面３，６の側は開放されているた
め、噴出空気が型表面３，６の滑らかさを保ったまま型
表面３，６から内部の水分を伴った気泡となって泡出す
る。そしてこのときに、多孔チューブ４より型外周部の
型表面側部分７の石膏に他の部分より多くの気孔を形成
し、この型外周部の型表面側部分７が型中央部８の頭頂
部８ａよりも高い気孔率を持った多孔質石膏となる。圧
縮空気を連続的に送気し、石膏中の水分泡出がほぼ終わ
るまで３０〜４０分間この操作を継続し、この間に注入
石膏を硬化させる。この送気中の石膏硬化に伴って、水
分泡出路が微細な気孔として石膏中に残留し、その後に
赤外線加熱等により石膏の完全硬化を行わせれば、多孔
質の石膏型が形成される。The compressed air thus introduced into the perforated tube 4 made of a sizing tube is blown out from the outer peripheral wall of the fibrous perforated tube 4 and dispersed inside the semi-hardened gypsum. However, while the mold center 1 and the portion on the mold 1 side of the perforated tube 4 are sealed by the mold 1, the mold surfaces 3 and 6 are open, so that the blown air is While maintaining the smoothness of 3, 6, bubbles form bubbles with the moisture inside from the mold surfaces 3, 6. At this time, more pores are formed in the plaster of the die surface side portion 7 of the die outer peripheral portion than the other portions than the porous tube 4, and the die surface side portion 7 of the die outer peripheral portion is the crown portion of the die central portion 8. A porous gypsum having a porosity higher than that of 8a is obtained. Compressed air is continuously fed, and this operation is continued for 30 to 40 minutes until the bubbling of water in the gypsum is almost finished, during which the injected gypsum is hardened. Along with the hardening of the gypsum during the air supply, the water bubble outlets remain in the gypsum as fine pores, and if the gypsum is then completely hardened by infrared heating or the like, a porous gypsum mold is formed.
【００２９】このように構成された本発明の多孔質成形
型は、従来品と同様に懸垂碍子等のセラミックスの成形
型として用いることができる。成形に際して、接続金具
を経て空気を吸引することによって、多孔チューブ４を
通して多孔質成形型の型表面３，６の全体を減圧にし、
成形体を型表面３，６に密着させて正確な形状に成形す
ることができる。また成形体の成形後は、接続金具１１
を経て多孔チューブ４によって多孔質成形型の内部に空
気を吹込めば、石膏型の型表面３，６から空気が噴出し
て成形体を強制的に型表面３，６から容易に離型させる
ことができる。しかも、本発明によれば空気は気孔率、
したがって吸水率の高い型表面側部分から集中的に噴出
するので、例えば、重量の重い碍子の製造にも十分な空
気噴出量が得られるうえ、碍子頭頂部に対する空気噴出
量を低く抑え碍子頭頂部が変形することを防止すること
ができる。The porous molding die of the present invention thus constructed can be used as a molding die for ceramics such as suspension insulators like the conventional products. At the time of molding, air is sucked through the connection fitting to reduce the pressure of the entire mold surfaces 3 and 6 of the porous molding mold through the porous tube 4.
The molded body can be brought into close contact with the mold surfaces 3 and 6 and molded into an accurate shape. After the molded body is molded, the connection fitting 11
If air is blown into the inside of the porous mold by the perforated tube 4 through the air, air is ejected from the mold surfaces 3 and 6 of the plaster mold and the molded body is forcibly released from the mold surfaces 3 and 6 easily. be able to. Moreover, according to the present invention, air has a porosity,
Therefore, since it is intensively ejected from the mold surface side portion having a high water absorption rate, for example, a sufficient air ejection amount can be obtained even in the production of a heavy-weight insulator, and the air ejection amount to the insulator crown is suppressed to a low level. Can be prevented from being deformed.
【００３０】以上に説明したように、本発明のセラミッ
クスの製造方法およびこれに用いられる多孔質成形型
は、例えば、碍子製造に適する気孔率と表面の滑らかさ
をもたせることができ、成形時の内表面部の減圧脱気に
より成形型に沿った正確な成形が可能で、しかも離型時
の内部加圧によるエアーブロー離型により容易に離型を
行うことができる。またこの多孔質成形型は表面の一部
が欠けたりしたような場合にも容易に修復することがで
きるので、製作費のみならずメンテナンス費も安価であ
る。As described above, the method for producing ceramics of the present invention and the porous molding die used therefor can have porosity and surface smoothness suitable for, for example, the production of insulators. Accurate molding along the molding die is possible by depressurizing deaeration of the inner surface portion, and furthermore, demolding can be easily performed by air blow demolding due to internal pressurization at the time of demolding. Further, since this porous mold can be easily repaired even when a part of the surface is chipped, not only the manufacturing cost but also the maintenance cost is low.
【００３１】表１は本発明による多孔質石膏型の吸水率
の範囲を示す比較テストの結果を示す。Table 1 shows the results of a comparative test showing the range of water absorption of the porous gypsum mold according to the present invention.
【表１】 [Table 1]
【００３２】本発明による多孔質石膏型の比較テストで
は、多孔チューブの位置、多孔チューブに導入される圧
縮空気の圧力および時間ならびに油粘土の押圧力を変え
ることによって型外周部の型表面側部分と型中央部の頭
頂部分での吸水率の組合わせを相違させた図１に示す構
造の多孔質石膏型を用い、これらの多孔質石膏型で中心
コア部１６の直径が６０ｍｍ、大径笠部１７の直径が２
５４ｍｍ、高さ１００ｍｍの送電線用懸垂碍子を、アル
ミナ１０〜３５％、長石２０〜３５％および粘土３０〜
４０％の組成のセラミックス材料を用いて多数準備し、
良否を判定した。In the comparative test of the porous gypsum mold according to the present invention, the position of the porous tube, the pressure and time of the compressed air introduced into the porous tube, and the pressing force of the oil clay are changed to change the peripheral portion of the mold surface side. Using a porous gypsum mold having a structure shown in FIG. 1 in which the combination of the water absorption rate at the top of the mold and the top part of the mold is different, the diameter of the central core portion 16 is 60 mm, and the large diameter shade is large. The diameter of the part 17 is 2
54mm, 100mm height suspension pendant for power line, alumina 10-35%, feldspar 20-35% and clay 30-
Prepare a large number of ceramic materials of 40% composition,
The quality was judged.
【００３３】型の吸水率は各型の型表面側部分および頭
頂部分から石膏試料を１５×１５×１５ｍｍ程度の大き
さに切断し、その表面をサンドペーパーで仕上げ、その
試料体を４０〜４５℃の熱風乾燥機にて恒量になるまで
約２４時間乾燥し、次に室温まで冷却した試料体の重量
を計り、乾燥重量を求め、その後試料体を常温水へ投入
し、直ちにそのまま７００ｍｍＨｇ以上で１時間減圧
し、次に試料体を水中より取り出し、ぬれた布で手早く
表面を拭いて水滴を除去したのちその試料体の重量を計
って吸水重量を求め、下記の計算式で吸水率を求めた。The water absorption of the mold was obtained by cutting a plaster sample from the mold surface side portion and the crown portion of each mold into a size of about 15 × 15 × 15 mm, finishing the surface with sandpaper, and measuring the sample body at 40 to 45 mm. Dry for about 24 hours in a hot air dryer at ℃ until constant weight, then weigh the sample cooled to room temperature, determine the dry weight, then put the sample into room temperature water and immediately leave it at 700 mmHg or more. Depressurize for 1 hour, then remove the sample body from water, quickly wipe the surface with a wet cloth to remove water droplets, weigh the sample body to obtain the water absorption weight, and calculate the water absorption rate using the following formula. It was
【数１】 表１中、発生した不良率を％で示し、その総合評価を良
○、稍良△および不良×で示す。[Equation 1] In Table 1, the defective rate that occurred is shown in%, and the comprehensive evaluation thereof is shown as good ◯, good Δ and bad x.
【００３４】[0034]
【発明の効果】本発明によれば、品質の良い懸垂碍子を
極めて高歩留りで製造することができ、不良品の発生を
実質的に零にすることができる。According to the present invention, a high quality suspended insulator can be manufactured with an extremely high yield, and the number of defective products can be substantially reduced to zero.
【図１】本発明の多孔質石膏型の一実施例を示す縦断面
図である。FIG. 1 is a longitudinal sectional view showing an embodiment of a porous gypsum mold of the present invention.
【図２】芯材によって保持された多孔チューブの正面図
である。FIG. 2 is a front view of a perforated tube held by a core material.
【図３】本発明による多孔質石膏型を製造する方法を示
す断面図である。FIG. 3 is a cross-sectional view showing a method for producing a porous gypsum mold according to the present invention.
【図４】本発明により製造されるセラミックスの一例を
その半部を断面として示す正面図である。FIG. 4 is a front view showing an example of a ceramic manufactured according to the present invention with its half section taken as a cross section.
【図５】図４に示した懸垂碍子を従来の多孔質石膏型を
用いて製造する際に生じる変形等の問題の説明図であ
る。FIG. 5 is an explanatory view of a problem such as deformation that occurs when the suspension insulator shown in FIG. 4 is manufactured using a conventional porous gypsum mold.
１ 型枠、２ 多孔質型本体、３ 型表面、４ 多孔チ
ューブ、５ 芯材、６ 型表面、７ 型外周部型表面側
部分、８ 型中央部、８ａ 型中央部頭頂部分、９ 非
通気性石膏、１０ ビニールチューブ、１１ 接続金
具、１２ 内型、１３ スペース、１５ 頭頂部、１６
中心コア部、１７ 大径笠部、1 mold frame, 2 porous mold body, 3 mold surface, 4 porous tube, 5 core material, 6 mold surface, 7 mold outer peripheral mold surface side portion, 8 mold central portion, 8a mold central portion crown portion, 9 non-ventilated Gypsum, 10 vinyl tubes, 11 connection fittings, 12 inner molds, 13 spaces, 15 crowns, 16
Central core part, 17 large diameter cap part,
Claims (6)
心コア部と、このコア部から半径方向に延長した大径笠
部とを有するセラミックスを、前記中心コア部および大
径笠部の外形に対応する形状の成形型表面を有する型中
央部および型外周部を含む型本体を具える多孔質成形型
の前記成形型表面に杯土を押し付けて成形した後、前記
成形型表面から気体を噴出させて成形体を離型するセラ
ミックス製造方法において、 前記多孔質成形型の型本体の吸水率が前記型外周部の表
面側部分において前記型中央部より高い多孔質成形型を
用いるセラミックスの製造方法。1. A ceramic having a small-diameter hollow cylindrical central core portion having a closed top portion and a large-diameter cap portion extending in a radial direction from the core portion, wherein the central core portion and the large-diameter cap portion are formed. Of the porous mold having a mold body having a mold surface having a mold surface of a shape corresponding to the outer shape of In a ceramics manufacturing method of ejecting a gas to release a molded body, a ceramic using a porous molding die in which a water absorption rate of a mold body of the porous molding die is higher in a surface side portion of the die outer peripheral portion than in the center portion of the die. Manufacturing method.
０〜３０％であり、前記型中央部の頭頂部分の吸水率が
１０〜２０％である請求項１記載の方法。2. The water absorption rate of the surface side portion of the die outer peripheral portion is 2
The method according to claim 1, wherein the water absorption rate is 0 to 30% and the water absorption rate of the crown portion of the center of the mold is 10 to 20%.
記型中央部の頭頂部分の吸水率Ｂとの差Ａ−Ｂが５〜２
０％である請求項２記載の方法。3. The difference A-B between the water absorption rate A of the surface side portion of the die outer peripheral portion and the water absorption rate B of the crown portion of the die central portion is 5 to 2
The method according to claim 2, which is 0%.
心コア部とこのコア部から半径方向に拡開した大形笠部
とを有する懸垂碍子その他同様のセラミックスの前記中
心コア部および大径笠部の外形にそれぞれ対応する形状
の成形型表面を有する型中央部および型外周部を含む型
本体を具える多孔質成形型において、前記型外周部の型
表面側部分の吸水率が前記型中央部の吸水率より大きい
セラミックス製造用多孔質成形型。4. A suspension insulator having a small-diameter hollow-cylindrical central core portion whose top is closed and a large cap portion radially expanded from the core portion. In a porous molding die including a die body including a die center portion and a die outer peripheral portion having a die surface having a shape corresponding to the outer shape of the large diameter cap portion, the water absorption rate of the die surface side portion of the die outer peripheral portion is A porous molding die for producing ceramics, which has a higher water absorption rate in the central portion of the die.
０〜３０％であり、前記型中央部の頭頂部分の吸水率が
１０〜２０％である請求項４記載の多孔質成形型。5. The water absorption rate of the mold surface side portion of the mold outer peripheral portion is 2
The porous molding die according to claim 4, which is 0 to 30% and has a water absorption rate of 10 to 20% at the crown portion in the center of the die.
の頭頂部分との吸水率の差が５〜２０％である請求項５
記載の多孔質成形型。6. The difference in water absorption between the surface side portion of the die outer peripheral portion and the crown portion of the die central portion is 5 to 20%.
The described porous mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32478293A JP2736004B2 (en) | 1993-12-22 | 1993-12-22 | Method for producing ceramics and porous mold used therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32478293A JP2736004B2 (en) | 1993-12-22 | 1993-12-22 | Method for producing ceramics and porous mold used therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07178713A true JPH07178713A (en) | 1995-07-18 |
| JP2736004B2 JP2736004B2 (en) | 1998-04-02 |
Family
ID=18169618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32478293A Expired - Lifetime JP2736004B2 (en) | 1993-12-22 | 1993-12-22 | Method for producing ceramics and porous mold used therefor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2736004B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102189592A (en) * | 2010-03-19 | 2011-09-21 | 日本碍子株式会社 | Suspension insulator forming mould |
| CN104070595A (en) * | 2013-03-27 | 2014-10-01 | 日本碍子株式会社 | Die for molding suspension insulator |
| CN104924413A (en) * | 2014-03-20 | 2015-09-23 | 日本碍子株式会社 | Suspension insulator forming mould |
| CN114368057A (en) * | 2022-01-18 | 2022-04-19 | 萍乡市汇能电气有限公司 | Back-blowing type forming die of suspension type ceramic insulator and preparation method thereof |
-
1993
- 1993-12-22 JP JP32478293A patent/JP2736004B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102189592A (en) * | 2010-03-19 | 2011-09-21 | 日本碍子株式会社 | Suspension insulator forming mould |
| JP2011194716A (en) * | 2010-03-19 | 2011-10-06 | Ngk Insulators Ltd | Suspension-type insulator molding die |
| CN102189592B (en) * | 2010-03-19 | 2015-04-01 | 日本碍子株式会社 | Suspension insulator forming mould |
| CN104070595A (en) * | 2013-03-27 | 2014-10-01 | 日本碍子株式会社 | Die for molding suspension insulator |
| JP2014188771A (en) * | 2013-03-27 | 2014-10-06 | Ngk Insulators Ltd | Suspension insulator molding die |
| CN104924413A (en) * | 2014-03-20 | 2015-09-23 | 日本碍子株式会社 | Suspension insulator forming mould |
| JP2015178255A (en) * | 2014-03-20 | 2015-10-08 | 日本碍子株式会社 | Suspension insulator forming die |
| CN104924413B (en) * | 2014-03-20 | 2018-08-24 | 日本碍子株式会社 | Shaping suspension insulator mold |
| CN114368057A (en) * | 2022-01-18 | 2022-04-19 | 萍乡市汇能电气有限公司 | Back-blowing type forming die of suspension type ceramic insulator and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2736004B2 (en) | 1998-04-02 |
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