JPH07291639A - Production of optical glass element - Google Patents
Production of optical glass elementInfo
- Publication number
- JPH07291639A JPH07291639A JP8023894A JP8023894A JPH07291639A JP H07291639 A JPH07291639 A JP H07291639A JP 8023894 A JP8023894 A JP 8023894A JP 8023894 A JP8023894 A JP 8023894A JP H07291639 A JPH07291639 A JP H07291639A
- Authority
- JP
- Japan
- Prior art keywords
- gob
- mold
- optical glass
- glass
- receiving
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B40/00—Preventing adhesion between glass and glass or between glass and the means used to shape it, hold it or support it
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B7/00—Distributors for the molten glass; Means for taking-off charges of molten glass; Producing the gob, e.g. controlling the gob shape, weight or delivery tact
- C03B7/14—Transferring molten glass or gobs to glass blowing or pressing machines
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Surface Treatment Of Glass (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は光学ガラス素子の製造方
法に関し、特に溶融ガラスからプレス成形までを一貫し
て行う方法において用いられる光学ガラス予備成形体
(以下、ガラスゴブと称する)を受ける表面の清浄なゴ
ブ受け型を所定回数の成形後新たに(間欠的に)供給す
る方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an optical glass element, and more particularly to a surface of a surface for receiving an optical glass preform (hereinafter referred to as a glass gob) used in a method for continuously performing from molten glass to press molding. The present invention relates to a method for newly (intermittently) supplying a clean gob receiving mold after molding a predetermined number of times.
【0002】[0002]
【従来の技術】従来、カメラやビデオ、あるいはCDな
どに用いられる光学ガラス素子は、ダイレクト・プレス
法による成形により、あるいは丸棒からの切り出しによ
り得られたガラスを研磨加工し、球形状や成形品類似形
状に研磨して、これを加熱成形することにより製造され
ていた。2. Description of the Related Art Conventionally, an optical glass element used for a camera, a video, a CD or the like has a spherical shape or a molded shape obtained by polishing a glass obtained by molding by a direct press method or cutting out from a round bar. It was manufactured by grinding into a shape similar to the product and then heat-molding this.
【0003】しかしながらこれらの方法ではガラス素材
の研磨コストが高く、また一度冷却して研磨したガラス
を室温から再加熱して成形するため製品を得るための時
間が非常に長いという欠点があった。However, these methods have the drawbacks that the cost for polishing the glass material is high and that the glass once cooled and polished is reheated from room temperature to be molded, so that the time for obtaining the product is very long.
【0004】このような欠点を解決すべく、最近加工工
程を含まず溶融ガラスから連続して光学ガラス素子を得
るプロセス(以下、ダイレクトモールド法と称する)に
より製品を得る試みが提案されている。例えば、特公平
4−16414号公報には大気雰囲気中でノズルより溶
融ガラスを自然滴下させ、これを成形用の下型で受けて
直ちに上型でプレス成形する方法が開示されている。ま
た、特開平4−77320号公報には第1の型で大気中
で溶融ガラスを受け、第2の型で非酸化性雰囲気中で加
熱プレス成形する方法が開示されている。In order to solve such a drawback, recently, an attempt has been proposed to obtain a product by a process (hereinafter referred to as a direct molding method) for continuously obtaining an optical glass element from a molten glass without including a processing step. For example, Japanese Patent Publication No. 4-16414 discloses a method in which molten glass is naturally dropped from a nozzle in an air atmosphere, received by a lower mold for molding, and immediately press-molded by an upper mold. Further, Japanese Patent Application Laid-Open No. 4-77320 discloses a method in which a first mold receives molten glass in the air, and a second mold performs hot press molding in a non-oxidizing atmosphere.
【0005】[0005]
【発明が解決しようとしている課題】しかしながら上記
のようなダイレクトモールド法においては、以下に示す
問題点がある。However, the above direct molding method has the following problems.
【0006】即ち、溶融ガラスを受ける受け型のガラス
−型接触面の近傍での受け型の表面にはガラスゴブの温
度が高いためガラスの揮発成分が付着し、ガラスゴブを
数十回受けることにより細粒状のガラス揮発物が堆積
し、ガラス揮発物の付着したガラスゴブを成形すると成
形品表面にキズ状の曇りが発生して不良品となる。That is, since the temperature of the glass gob is high in the vicinity of the glass-mold contact surface of the glass mold that receives the molten glass, the volatile components of the glass adhere to the surface of the glass gob. When granular glass volatiles are deposited and a glass gob to which the glass volatiles are attached is molded, scratches are generated on the surface of the molded product, resulting in a defective product.
【0007】前記特公平4−16414号公報に記載の
方法は、大気雰囲気中でガラスをオリフィスから落下さ
せる際、オリフィス出口と受け型との距離を3m程度と
することにより受け型と接触する時のガラスの表面温度
をガラス軟化点より低下させて受け型へのガラス揮発物
の付着量の低減が図られている。According to the method disclosed in Japanese Patent Publication No. 4-16414, when the glass is dropped from the orifice in the atmosphere, the glass is brought into contact with the receiving die by setting the distance between the orifice outlet and the receiving die to be about 3 m. The glass surface temperature is lowered below the glass softening point to reduce the amount of glass volatiles attached to the receiving mold.
【0008】しかしながら、ガラス軟化点より低温でも
ガラスの揮発物は受け型に少量ずつ堆積し、特にこの方
法ではオリフィス出口と受との距離が長いために、ガラ
スゴブの受け型に落下する位置のばらつきが大きいため
受け型上に堆積したガラス揮発物がガラスゴブに付着す
る確率が高く、かつ受け型を精密成形型と兼用している
ため精密成形後不良品が多く発生する。However, even at a temperature lower than the glass softening point, glass volatiles are deposited little by little on the receiving mold. In particular, in this method, the distance between the orifice outlet and the receiving container is long, so that the position of the glass gob falling on the receiving mold varies. Is large, the glass volatiles deposited on the receiving die have a high probability of adhering to the glass gob, and since the receiving die is also used as the precision forming die, many defective products occur after the precision forming.
【0009】またオリフィス出口と受け型までの距離を
長くとる結果、装置全体が大型化し付帯設備を含めた総
設備費が高くなり、そのために製造する光学素子のコス
トが高くなるという欠点がある。Further, as a result of increasing the distance between the orifice outlet and the receiving die, there is a drawback that the entire apparatus becomes large and the total equipment cost including the auxiliary equipment becomes high, and thus the cost of the optical element to be manufactured becomes high.
【0010】一方、前記特開平4−77320号公報に
記載の方法は、ガラスを大気中で加熱していない第1の
型で受けた後、直ちに非酸化性雰囲気中に導入し第2の
型に移して成形するものである。On the other hand, in the method described in the above-mentioned Japanese Patent Application Laid-Open No. 4-77320, after the glass is received by the first mold which is not heated in the atmosphere, it is immediately introduced into the non-oxidizing atmosphere and the second mold. It is transferred to and molded.
【0011】しかしながらこの方法でも第1の型が高温
のガラスを受けることは避けられず、連続して使用する
と型表面にガラスからの揮発物が堆積し、ガラスゴブ表
面に付着して精密成形後不良品が多く発生する。However, even with this method, it is unavoidable that the first mold receives high temperature glass, and if it is used continuously, volatiles from the glass will be deposited on the surface of the mold and adhere to the surface of the glass gob to cause imperfections after precision molding. A lot of good products occur.
【0012】本発明の目的は、従来技術の問題点に鑑み
て、ダイレクトモールド法において表面の清浄なガラス
ゴブを連続的に得ることによって、表面の良好な光学ガ
ラス素子を効率的に製造することのできる方法を提供す
ることである。In view of the problems of the prior art, it is an object of the present invention to efficiently produce an optical glass element having a good surface by continuously obtaining a glass gob having a clean surface in the direct molding method. It is to provide a possible method.
【0013】[0013]
【課題を解決するための手段】上記目的を達成する本発
明は、ガラスゴブを受けるゴブ受け型を複数個用意し、
洗浄,乾燥して間欠的に交換して供給する工程、該ゴブ
受け型を反転させてガラスゴブを精密成形型に落下させ
る工程、精密成形型に載置されたガラスゴブをプレス成
形して光学ガラス素子を得る工程を有してなる光学ガラ
ス素子の製造方法である。The present invention for achieving the above object provides a plurality of gob receiving molds for receiving glass gobs,
Washing, drying and intermittently replacing and supplying, a step of reversing the gob receiving mold to drop the glass gob into a precision molding die, a glass gob placed on the precision molding die by press molding, and an optical glass element A method for producing an optical glass element, which comprises the step of obtaining
【0014】また、本発明は、ゴブ受け型の洗浄方法と
して酸またはアルカリの水溶液及びまたは水を用い、洗
浄液に超音波振動を付加することを含むものである。Further, the present invention includes, as a gob-receiving type cleaning method, using an aqueous solution of acid or alkali and / or water and applying ultrasonic vibration to the cleaning solution.
【0015】また、本発明は、ゴブ受け型の乾燥方法と
して有機溶媒置換及びまたは熱風を用いることを含むも
のである。Further, the present invention includes the use of organic solvent substitution and / or hot air as a gob-receiving type drying method.
【0016】また、本発明は、少なくとも前記精密成形
型上に載置されたガラスゴブをプレス成形して光学ガラ
ス素子を得る工程を非酸化性雰囲気中で実施することを
含むものである。The present invention also includes at least the step of press-molding a glass gob placed on the precision mold to obtain an optical glass element in a non-oxidizing atmosphere.
【0017】本発明においてはゴブ受け型に付着するガ
ラス揮発物によるガラスゴブの汚染を防ぐために、おお
むね20回ガラスゴブを受けたゴブ受け型を自動的に新
しいゴブ受け型と交換するために、複数個のゴブ受け型
を用意し、汚れたゴブ受け型を次々と洗浄,乾燥するこ
とにより表面の清浄なゴブ受け型に復帰させて繰り返し
使用する方法により、連続的に精密成形型に表面の清浄
なガラスゴブを供給して、一貫したプロセスにより連続
して表面良好な光学ガラス素子を得ることができる。In the present invention, in order to prevent the glass gob from being contaminated by the glass volatiles adhering to the gob receiving mold, a plurality of gob receiving molds which have received the glass gob about 20 times are automatically replaced with a new gob receiving mold. Prepare a gob receiving mold of No. 2, and wash and dry the dirty gob receiving mold one after another to return to a gob receiving mold with a clean surface, and then use it repeatedly to continuously clean the precision mold with a clean surface. A glass gob can be fed to continuously obtain good surface optical glass elements by a consistent process.
【0018】[0018]
【実施例】以下、本発明の好適な実施例を、添付図面を
参照して詳細に説明する。図1には、本発明に使用した
ゴブ受け型の自動交換機構及び洗浄・乾燥機構が示され
ている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a gob receiving type automatic changing mechanism and a cleaning / drying mechanism used in the present invention.
【0019】また図2には、ガラスゴブが精密成形室内
でプレス成形される工程が示されている。オリフィス1
から流出された溶融ガラスはゴブ受け型2によって受け
られ、ガラスゴブ3として保持される。この時ゴブ受け
型2が室温に保たれていると、ガラスゴブの下面は急激
に温度低下を起こし、収縮によって引けや襞を生じるた
め、このまま精密成形工程に進む場合に光学ガラス素子
に欠陥が生じることが多くなる。このため本発明では図
1に示すように、受け型の温度調節が行なえるように、
受け型の底部にヒーター4を挿入した機構が設けられ
る。ここで、ヒーターは通常500℃程度の加熱が可能
なカートリッジヒーターを使用し、このヒーターを挿入
する部材5としては、熱伝導率が高く耐熱性の良い耐熱
合金などを用いる。Further, FIG. 2 shows a step in which the glass gob is press-molded in the precision molding chamber. Orifice 1
The molten glass flowing out of the glass is received by the gob receiving mold 2 and held as the glass gob 3. At this time, if the gob receiving mold 2 is kept at room temperature, the temperature of the lower surface of the glass gob suddenly drops, and shrinkage or folds occur due to shrinkage, so that a defect occurs in the optical glass element when proceeding to the precision molding step as it is. More often. Therefore, in the present invention, as shown in FIG.
A mechanism in which the heater 4 is inserted in the bottom of the receiving mold is provided. Here, the heater is usually a cartridge heater capable of heating at about 500 ° C., and the member 5 into which the heater is inserted is made of a heat-resistant alloy having a high thermal conductivity and a high heat resistance.
【0020】またこのゴブ受け型には、回転可能な機構
6が設けられており、それを反転させ、同時にシャッタ
ー7を開くことにより、ガラスゴブを精密成形室8内に
落下させ、予めその下に位置した精密成形用下型9の上
に受けるのである。Further, this gob receiving mold is provided with a rotatable mechanism 6, which is turned upside down and at the same time, the shutter 7 is opened to drop the glass gob into the precision molding chamber 8 and under it. It is received on the positioned precision molding lower die 9.
【0021】またこのゴブ受け型はヒーター挿入部材5
及び回転可能な機構6と一体化して構成されており、回
転可能な支柱10に対して対称となるように左右一対、
合計2組設けられている。The gob receiving type is a heater insertion member 5
And a rotatable mechanism 6, which are integrated with each other.
There are two sets in total.
【0022】次にこのゴブ受け型の洗浄・乾燥機構につ
いて説明する。Next, the cleaning / drying mechanism of the gob receiving type will be described.
【0023】所定回数使用されガラス揮発物の付着した
ゴブ受け型は、支柱10を180度回転させて新しいゴ
ブ受け型と交換され、連続してガラスゴブを受けること
が可能となるよう構成されている。The gob receiving mold, which has been used a predetermined number of times and has glass volatiles attached, is replaced with a new gob receiving mold by rotating the column 10 by 180 degrees so that it is possible to continuously receive the glass gob. .
【0024】使用済のゴブ受け型は、交換後直ちにオー
トハンド11によりヒーター挿入部材から取り出され、
まず超音波洗浄槽1内に移送される。The used gob receiving mold is taken out from the heater insertion member by the auto hand 11 immediately after replacement,
First, it is transferred into the ultrasonic cleaning tank 1.
【0025】超音波洗浄槽1内には、予め所定の濃度に
調製された酸またはアルカリの水溶液、または純水がゴ
ブ受け型洗浄に充分な量満たされており、受け型表面に
付着したガラス揮発物が完全に溶解除去されるまで、所
定時間超音波洗浄が行なわれる。The ultrasonic cleaning tank 1 is filled with an aqueous solution of an acid or an alkali or a pure water, which is prepared in advance to a predetermined concentration, in an amount sufficient for the gob receiving type cleaning, and the glass adhered to the receiving type surface. Ultrasonic cleaning is performed for a predetermined time until the volatile substances are completely dissolved and removed.
【0026】次にゴブ受け型はオートハンドにより超音
波洗浄槽2内に移送される。超音波洗浄槽2内には純水
が満たされており、超音波洗浄槽1で酸またはアルカリ
の水溶液を用いた場合ゴブ受け型に付着した酸またはア
ルカリ或はガラス揮発物の溶解物を除去するために、所
定時間超音波洗浄が行なわれる。Next, the gob receiving mold is transferred into the ultrasonic cleaning tank 2 by an automatic hand. The ultrasonic cleaning tank 2 is filled with pure water, and when an aqueous solution of acid or alkali is used in the ultrasonic cleaning tank 1, the dissolved matter of acid, alkali or glass volatiles attached to the gob receiver is removed. To this end, ultrasonic cleaning is performed for a predetermined time.
【0027】次にゴブ受け型はオートハンドにより有機
溶媒槽内に移送される。Next, the gob receiving mold is transferred into the organic solvent tank by an auto hand.
【0028】有機溶媒槽内には前工程でゴブ受け型に付
着した水分を有機溶媒に置換するために充分な量のイソ
プロピルアルコール等の溶媒が満たされており、所定時
間溶媒置換が行なわれる。The organic solvent tank is filled with a sufficient amount of solvent such as isopropyl alcohol for replacing the water adhering to the gob receiving mold with the organic solvent in the previous step, and the solvent replacement is carried out for a predetermined time.
【0029】次にゴブ受け型は熱風をパージする機構
(図示せず)を備えた乾燥室内へ移送される。熱風には
前工程で使用した有機溶媒の揮発温度以上に熱せられた
気体を用いることが望ましく、通常は90℃以上の空気
を用いれば良い。Next, the gob receiving mold is transferred into a drying chamber equipped with a mechanism (not shown) for purging hot air. As the hot air, it is desirable to use a gas heated to a temperature equal to or higher than the volatilization temperature of the organic solvent used in the previous step, and air having a temperature of 90 ° C. or higher is usually used.
【0030】充分に乾燥されたゴブ受け型は、交換用の
ゴブ受け型として待機した後、オートハンドにより移送
され前記部材5内に装着して繰り返し使用される。The fully dried gob receiving mold is waited as a replacement gob receiving mold, then transferred by an auto hand and mounted in the member 5 for repeated use.
【0031】以上説明した工程で用いられるゴブ受け型
の数量は最低2個以上であり、通常ガラスの硝種によっ
て異なるゴブ受け型の汚れの状況や、ゴブ受けのタクト
との関係で数個〜10個程度使用される。The number of gob receiving molds used in the above-described process is at least two or more, and usually several to 10 depending on the condition of dirt of the gob catching mold which differs depending on the glass type of glass and the tact of the gob catching. Used about individually.
【0032】次に精密成形工程について説明する。Next, the precision molding process will be described.
【0033】精密成形用下型9は、予めシャッター12
のある開口部を通ってベルトコンベア13により成形室
内に順次搬送されていて、そこでまずヒーター14によ
り予備加熱工程を経て、成形温度に近い温度まで予熱さ
れ、そして上述のようにガラスゴブを受けた後で、内蔵
ヒーター15を備えた精密成形用上型16の下に位置さ
れ、次いで上型16が降下して、これによりガラスをプ
レス成形するのである。The lower mold 9 for precision molding has a shutter 12 in advance.
After being sequentially conveyed into the molding chamber by the belt conveyor 13 through an opening having a hole, the heater 14 first performs a preheating process, preheats to a temperature close to the molding temperature, and receives the glass gob as described above. Then, it is positioned below the precision molding upper die 16 having the built-in heater 15, and then the upper die 16 descends, thereby press-molding the glass.
【0034】そして下型9と共に光学ガラス素子(成形
品)はシャッター17のある開口部に至るまで冷却さ
れ、上記開口部を通って成形室外に取り出される。取り
出された光学ガラス素子18は真空チャック方式の吸着
ハンド19により下型9から取り出され、一方下型9は
適当な搬送手段の働きで、コンベアの成形室入口の位置
に戻され、再び成形室8内に移送される。Then, the optical glass element (molded product) together with the lower mold 9 is cooled down to the opening with the shutter 17, and is taken out of the molding chamber through the opening. The taken out optical glass element 18 is taken out from the lower mold 9 by a suction hand 19 of a vacuum chuck system, while the lower mold 9 is returned to the position of the molding chamber inlet of the conveyor by the action of an appropriate conveying means and is again molded into the molding chamber. 8 is transferred.
【0035】なお、成形室8内の雰囲気は、非酸化性の
ガスをガス導入管20より連続的に供給することで与え
られる。また成形室内部を大気圧ないし正圧に保ち、シ
ャッター7,12,17などの開閉操作の際、外部から
酸素を含む大気が導入されるのを防止する。このため、
ガス排出管21は、この時点ではその流れを止められ
る。The atmosphere in the molding chamber 8 is provided by continuously supplying a non-oxidizing gas from the gas introduction pipe 20. Further, the inside of the molding chamber is kept at atmospheric pressure or positive pressure to prevent introduction of the atmosphere containing oxygen from the outside when opening / closing the shutters 7, 12, 17 and the like. For this reason,
The gas discharge pipe 21 has its flow stopped at this point.
【0036】以上のようにして、本発明に関わる成形シ
ステムが連続プロセスの中で実現される。この場合のゴ
ブ受け型の洗浄・乾燥方法について以下の数例にて詳述
するるAs described above, the molding system according to the present invention is realized in a continuous process. The gob-receiving type cleaning / drying method in this case will be described in detail in the following several examples.
【0037】(実施例1)ここでは、ゴブ受け型にガラ
ス状カーボンを使用した。Example 1 Here, glassy carbon was used for the gob receiving mold.
【0038】まずブロック状のガラス状カーボンから切
り出して、30mmφ,6mmt の円板状試料を得た。
然る後、円板の片面の中央部をR:22mm,深さ3m
mに研削加工した後酸化セリウムを用いてR面を鏡面研
磨した。こうして得られたゴブ受け型を耐熱合金で作製
したヒーターブロック内に装着した。First, a block-shaped glassy carbon was cut out to obtain a disk-shaped sample of 30 mmφ and 6 mm t .
After that, the center part of one side of the disk is R: 22 mm, depth 3 m
After grinding to m, the R surface was mirror-polished with cerium oxide. The gob receiving mold thus obtained was mounted in a heater block made of a heat-resistant alloy.
【0039】また、ゴブ受け型からゴブを受ける精密成
形型は下型,上型ともに以下の方法で作製した。Further, the precision molding die for receiving the gob from the gob receiving die was manufactured by the following method for both the lower die and the upper die.
【0040】この成形型の母材には、炭化タングステン
(90wt.%)とコバルト(10wt.%)との超硬
合金を用いる。その形状としては、30mmφ,6mm
t の円板を作製した後、ガラスを成形する面をR:16
mm,深さ2.3mmの形状に研削研磨して、表面粗さ
2nmの鏡面に仕上げる。更に、白金ターゲット上にシ
リコン・チップを載せ、窒素雰囲気下でスパッター法に
より鏡面加工された母材面に、組成(原子%)が白金
(53%)、シリコン+窒素(47%)の白金半導体混
合物を1μmの厚さで形成し、精密成形型とした。A cemented carbide of tungsten carbide (90 wt.%) And cobalt (10 wt.%) Is used as the base material of this mold. The shape is 30mmφ, 6mm
After producing a disk of t , the surface for molding glass is R: 16
mm and depth 2.3 mm are ground and polished to a mirror surface having a surface roughness of 2 nm. Furthermore, a silicon chip is placed on a platinum target, and a platinum semiconductor whose composition (atomic%) is platinum (53%) and silicon + nitrogen (47%) is formed on a base material surface which is mirror-finished by a sputtering method in a nitrogen atmosphere. The mixture was formed to a thickness of 1 μm to obtain a precision mold.
【0041】また、雰囲気については、溶融ガラスをゴ
ブ受け型で直接受ける工程では大気中で、また精密成形
を行う工程については、成形室内で予め窒素ガスを15
リッター/分でパージして窒素雰囲気となるよう調整し
た。Regarding the atmosphere, in the step of directly receiving the molten glass with the gob-receiving mold, in the atmosphere, and in the step of performing precision molding, nitrogen gas is preliminarily set to 15 in the molding chamber.
The nitrogen atmosphere was adjusted by purging with a liter / minute.
【0042】また、溶融ガラスについては、SK12に
相当する光学特性を有するガラスを用いた。このガラス
は硼珪酸バリウム系のガラス組成を有し、その軟化点温
度は630℃である。このガラスを1200℃で溶融
し、オリフィスから約1.5gの溶融ガラスを、予め4
00℃に温度調節されたガラス状カーボン受け型内へ滴
下した。滴下した溶融ガラスは10秒間受け型内で保持
された後、受け型の反転で、同時に高速開閉シャッター
が開放された開口部から精密成形室内に落下し、コンベ
ア上の予め570℃に加熱均熱化された精密成形用下型
に載せられる。As the molten glass, glass having optical characteristics equivalent to SK12 was used. This glass has a barium borosilicate glass composition, and its softening point temperature is 630 ° C. This glass was melted at 1200 ° C., and about 1.5 g of molten glass was preliminarily mixed with 4
It was dropped into a glassy carbon receiving mold whose temperature was adjusted to 00 ° C. The dropped molten glass is held in the receiving mold for 10 seconds, and then the receiving mold is reversed, and at the same time, it drops into the precision molding chamber through the opening where the high-speed opening / closing shutter is opened, and is heated and preheated to 570 ° C on the conveyor in advance. It is put on the lower mold for precision molding.
【0043】なお、オリフィス先端部からガラス状カー
ボン受け型までの距離は5cm、同じく精密成形用下型
までの距離は25cmとした。The distance from the tip of the orifice to the glassy carbon receiving mold was 5 cm, and the distance to the precision molding lower mold was 25 cm.
【0044】その後、コンベアの動作で下型を予備加熱
工程へ搬送し、570℃の温度で2分間下型と共にガラ
スゴブを加熱した。次にコンベアによってプレス工程へ
ガラスゴブを載せた下型を搬送し、そこで直ちに、予め
570℃に加熱均熱化された上型を用いて、4×106
Paの圧力で2分間プレス成形した。プレス成形時にガ
ラスの温度が一定になるように、上型の内蔵ヒーター及
び下型の下方設置のヒーターを用いて型の温度を制御し
た。その後、成形品(光学ガラス素子)を載せた下型
は、コンベアにより冷却工程へ搬送され2分間自然放冷
され、その後シャッターの高速開放で成形室から外部に
搬出され、吸着ハンドで下型から取り出される。Then, the lower mold was conveyed to the preheating step by the operation of the conveyor, and the glass gob was heated together with the lower mold at a temperature of 570 ° C. for 2 minutes. Next, the lower mold on which the glass gob was placed was conveyed to the pressing step by a conveyor, and immediately there, using an upper mold which had been preheated to 570 ° C., 4 × 10 6 was used.
Press molding was performed at a pressure of Pa for 2 minutes. The temperature of the mold was controlled using an internal heater of the upper mold and a heater installed below the lower mold so that the temperature of the glass was constant during press molding. After that, the lower mold on which the molded product (optical glass element) is placed is conveyed to the cooling step by the conveyor and naturally cooled for 2 minutes, and then discharged from the molding chamber to the outside by the high speed opening of the shutter, and the lower mold is moved by the suction hand. Taken out.
【0045】以上、一連のプロセスに従って成形を実施
した際、ゴブ受け型は3個使用しガラスゴブを20個受
けるごとに新しいものと交換して使用し、合計200個
の光学ガラス素子を作製した。As described above, when molding was carried out according to a series of processes, three gob receiving molds were used, and every time 20 glass gobs were received, they were replaced with new ones to prepare a total of 200 optical glass elements.
【0046】ゴブ受け型の洗浄、溶媒置換方法としては
表1に示す13条件で行い、合計2600個の光学ガラ
ス素子を得た。なお、表1で省いた超音波洗浄槽2の条
件については、純水を使用し25℃,30秒で、また乾
燥室内の条件は空気を使用し90℃,30秒でそれぞれ
13条件について同一方法で行った。The cleaning of the gob-receiving type and the solvent replacement method were carried out under the 13 conditions shown in Table 1 to obtain a total of 2600 optical glass elements. The conditions of the ultrasonic cleaning tank 2 omitted in Table 1 are pure water at 25 ° C. for 30 seconds, and the conditions in the drying chamber are air at 90 ° C. for 30 seconds. Made by way.
【0047】また比較例の実験としては、ゴブ受け型を
交換せず200個のガラスゴブを連続して1個のゴブ受
け型でうけたものをプレス成形して行い、合計200個
の光学ガラス素子を作製した。Further, as an experiment of a comparative example, without changing the gob receiving mold, 200 glass gobs continuously received by one gob receiving mold were press-molded to make a total of 200 optical glass elements. Was produced.
【0048】得られた光学ガラス素子の評価は、その表
面状態を光学顕微鏡,EPMA(電子線プローブ・マイ
クロアナライザー)及びSEMで観察し、表面精度につ
いてはZygo社製のZygo−MARK3を使用し
た。その結果、ゴブ受け型をゴブ受け20個ごとに交換
し、表1に示す13条件で洗浄・乾燥する方法で得られ
た2600個の試料については、すべてについて、その
表面に欠陥を観察することができず、かつ表面精度もニ
ュートン本数にして1.5本以下で、非常に良好な性能
を有する光学ガラス素子を連続して得ることができた。
一方、ゴブ受け型を交換せず200個のガラスゴブを連
続して受けた比較例の場合には、25個目以降のプレス
成形品総てにおいて表面に白い異物が観察され、良好な
光学ガラス素子を得ることができなかった。それらの異
物をEPMAで分析するとガラス組成中に存在するB,
Na,Kが検出され、ガラスゴブにゴブ受け型に堆積し
たガラス揮発物が付着したものと判断された。For the evaluation of the obtained optical glass element, the surface condition was observed with an optical microscope, EPMA (electron probe / microanalyzer) and SEM, and Zygo-MARK3 manufactured by Zygo was used for surface accuracy. As a result, for every 2600 samples obtained by replacing the gob receiving mold with every 20 gob receiving molds and washing and drying under the 13 conditions shown in Table 1, observe defects on the surface. In addition, the surface accuracy was 1.5 or less in Newton number, and it was possible to continuously obtain optical glass elements having very good performance.
On the other hand, in the case of the comparative example in which 200 glass gobs were continuously received without exchanging the gob receiving die, white foreign matter was observed on the surface in all the press-molded products after the 25th glass, and good optical glass elements were obtained. Couldn't get When these foreign substances are analyzed by EPMA, B existing in the glass composition,
Na and K were detected, and it was judged that the glass volatiles deposited in the gob-receiving type adhered to the glass gob.
【0049】[0049]
【表1】 [Table 1]
【0050】(実施例2)ここでは、ゴブ受け型の材料
としてHOPG(highly oriented p
yrolytic graphite:高配向性熱分解
黒鉛)を使用した。この材料は離型性の優れたカーボン
系の中でも特に耐熱性に優れている。(Embodiment 2) Here, a HOPG (highly oriented p-type) is used as a gob receiving type material.
(yrolytic graphite: highly oriented pyrolytic graphite) was used. This material is particularly excellent in heat resistance among carbon-based materials having excellent releasability.
【0051】HOPGは熱CVD法で作製し、等方性黒
鉛をコア部材としてそれにコーティングする方法で使用
した。HOPG was produced by a thermal CVD method and used as a core member coated with isotropic graphite.
【0052】まずブロック状の等方性黒鉛から切り出し
て、30mmφ,6mmt の円板状試料を得た。然る
後、円板の片面の中央部をR:22mm,深さ3mmに
研削加工した後、酸化セリウムを用いてR面を鏡面研磨
した。その後、等方性黒鉛を2400℃に加熱し、市販
のプロパンガスを導入してHOPGコーティングを行
い、膜厚30μmのHOPG層でコア材を完全に被覆し
た。こうして得られたゴブ受け型を耐熱合金で作製した
ヒーターブロック内に装着した。First, a block-shaped isotropic graphite was cut out to obtain a disk-shaped sample of 30 mmφ and 6 mm t . After that, the central portion of one surface of the disk was ground to have R: 22 mm and a depth of 3 mm, and then the R surface was mirror-polished with cerium oxide. Then, the isotropic graphite was heated to 2400 ° C., a commercially available propane gas was introduced to perform HOPG coating, and the core material was completely covered with a HOPG layer having a film thickness of 30 μm. The gob receiving mold thus obtained was mounted in a heater block made of a heat-resistant alloy.
【0053】また、ゴブ受け型からゴブを受ける精密成
形型は下型,上型ともに実施例1と同様のものを使用し
た。As the precision molding die for receiving the gob from the gob receiving die, the same lower and upper molds as in Example 1 were used.
【0054】また、雰囲気については、溶融ガラスをゴ
ブ受け型で直接受ける工程は大気中で、また、精密成形
を行う工程では精密成形室内に予めガス導入管より98
%窒素+2%水素の混合ガスを15リッター/分でパー
ジして雰囲気の調整をした。Regarding the atmosphere, in the step of directly receiving the molten glass with the gob-receiving mold, in the atmosphere, and in the step of performing precision molding, the gas is introduced into the precision molding chamber in advance from the gas introduction pipe.
The atmosphere was adjusted by purging a mixed gas of% nitrogen + 2% hydrogen at 15 liters / minute.
【0055】また、溶融ガラスには、LaK12相当の
光学特性を有するランタン系ガラスを用いた。このガラ
スの軟化点温度は655℃である。このガラスを130
0℃で溶融し、オリフィスから約1.5gの溶融ガラス
を、500℃に予め温度調節されたHOPG受け型へ滴
下した。HOPG受け型のガラスゴブは、10秒間受け
型内で保持された後、受け型の反転で、同時に高速開閉
シャッターが開放された開口部から精密成形室内に落下
し、コンベア上の、予め620℃に加熱均熱化された精
密成形用下型に載せられる。As the molten glass, lanthanum-based glass having optical characteristics equivalent to LaK12 was used. The softening point temperature of this glass is 655 ° C. 130 this glass
It melted at 0 ° C., and about 1.5 g of molten glass was dropped from an orifice into a HOPG receiving mold whose temperature was adjusted to 500 ° C. in advance. The HOPG receiving-type glass gob was held in the receiving mold for 10 seconds, and then when the receiving mold was turned over, it dropped into the precision molding chamber through the opening where the high-speed opening / closing shutter was opened at the same time. It is placed on a precision molding lower mold that has been heated and soaked.
【0056】なお、オリフィス先端部からHOPG受け
型までの距離は5cm、同じく精密成形用下型までの距
離は25cmとした。The distance from the tip of the orifice to the HOPG receiving mold was 5 cm, and the distance to the precision molding lower mold was 25 cm.
【0057】その後、コンベアの動作で下型を予備加熱
工程へ搬送し、620℃の温度で2分間下型と共にガラ
スゴブを加熱した。次にコンベアによってプレス工程へ
ガラスゴブを載せた下型を搬送し、そこで直ちに、予め
620℃に加熱均熱化された上型を用いて、3×106
Paの圧力で2分間プレス成形した。プレス成形時にガ
ラスの温度が一定になるように、上型の内蔵ヒーター及
び下型の下方設置のヒーターを用いて型の温度を制御し
た。その後、成形品(光学ガラス素子)を載せた下型
は、コンベアにより冷却工程へ搬送され2分間自然放冷
され、その後シャッターの高速開放で成形室から外部に
搬出され、吸着ハンドで下型から取り出される。Then, the lower mold was conveyed to the preheating step by the operation of the conveyor, and the glass gob was heated together with the lower mold at a temperature of 620 ° C. for 2 minutes. Next, the lower mold on which the glass gob was placed was conveyed to the pressing step by the conveyer, and immediately there, 3 × 10 6 was used by using the upper mold that had been preheated to 620 ° C.
Press molding was performed at a pressure of Pa for 2 minutes. The temperature of the mold was controlled using an internal heater of the upper mold and a heater installed below the lower mold so that the temperature of the glass was constant during press molding. After that, the lower mold on which the molded product (optical glass element) is placed is conveyed to the cooling step by the conveyor and naturally cooled for 2 minutes, and then discharged from the molding chamber to the outside by the high speed opening of the shutter, and the lower mold is moved by the suction hand. Taken out.
【0058】以上、一連のプロセスに従って成形を実施
した際、ゴブ受け型は3個使用しガラスゴブを20個受
けるごとに新しいものと交換して使用し、合計200個
の光学ガラス素子を作製した。As described above, when molding was carried out according to the series of processes, three gob receiving molds were used, and a new one was used every time 20 glass gobs were received, and a total of 200 optical glass elements were manufactured.
【0059】ゴブ受け型の洗浄、溶融置換方法としては
実施例1と同様に表1に示す13条件で行い、合計26
00個の光学ガラス素子を得た。なお、表1で省いた超
音波洗浄槽2の条件については、純水を使用し25℃,
30秒で、また乾燥室内の条件は空気を使用し90℃,
30秒でそれぞれ13条件について同一方法で行った。As the method of cleaning and melting and replacing the gob-receiving type, the same procedure as in Example 1 was carried out under the 13 conditions shown in Table 1, and a total of 26
00 optical glass elements were obtained. Regarding the conditions of the ultrasonic cleaning tank 2 omitted in Table 1, pure water was used at 25 ° C.
30 seconds, and the conditions in the drying chamber are 90 ° C using air.
The same method was performed for 13 conditions in 30 seconds.
【0060】また比較例の実験としては、ゴブ受け型を
交換せず200個のガラスゴブを連続して1個のゴブ受
け型でうけたものをプレス成形して行い、合計200個
の光学ガラス素子を作製した。Further, as an experiment of a comparative example, without changing the gob receiving mold, 200 glass gobs continuously received by one gob receiving mold were press-molded to make a total of 200 optical glass elements. Was produced.
【0061】得られた光学ガラス素子の評価は、その表
面状態を光学顕微鏡,EPMA(電子線プローブ・マイ
クロアナライザー)及びSEMで観察し、表面精度につ
いてはZygo社製のZygo−MARK3を使用し
た。その結果、ゴブ受け型をゴブ受け20個ごとに交換
し、表1に示す13条件で洗浄・乾燥する方法で得られ
た2600個の試料については、すべてについて、その
表面に欠陥を観察することができず、かつ表面精度もニ
ュートン本数にして1.5本以下で、非常に良好な性能
を有する光学ガラス素子を連続して得ることができた。
一方、ゴブ受け型を交換せず200個のガラスゴブを連
続して受けた比較例の場合には、23個目以降のプレス
成形品総てにおいて表面に白い異物が観察され、良好な
光学ガラス素子を得ることができなかった。それらの異
物をEPMAで分析するとガラス組成中に存在するB,
Naが検出され、ガラスゴブにゴブ受け型に堆積したガ
ラス揮発物が付着したものと判断された。The evaluation of the obtained optical glass element was carried out by observing the surface state with an optical microscope, EPMA (electron probe / microanalyzer) and SEM, and for surface accuracy, Zygo-MARK3 manufactured by Zygo was used. As a result, for every 2600 samples obtained by replacing the gob receiving mold with every 20 gob receiving molds and washing and drying under the 13 conditions shown in Table 1, observe defects on the surface. In addition, the surface accuracy was 1.5 or less in Newton number, and it was possible to continuously obtain optical glass elements having very good performance.
On the other hand, in the case of the comparative example in which 200 glass gobs were continuously received without exchanging the gob receiving die, white foreign matter was observed on the surface in all the press-molded products after the 23rd, and good optical glass elements were obtained. Couldn't get When these foreign substances are analyzed by EPMA, B existing in the glass composition,
Na was detected, and it was determined that the glass volatiles deposited in the gob-receiving mold adhered to the glass gob.
【0062】[0062]
【発明の効果】以上説明したように、本発明の光学ガラ
ス素子の成形システムによれば、汚れたゴブ受け型を次
々と洗浄,乾燥することにより表面の清浄なゴブ受け型
に復帰させて繰り返し使用する方法により、連続的に精
密成形型に表面の清浄なガラスゴブを供給して、一貫し
たプロセスにより連続して表面良好な光学ガラス素子を
得ることができる。かつ、ガラスゴブ温度が高温に保た
れるので成形タクトが短縮でき、製品のコストダウンが
可能となる。As described above, according to the molding system of the optical glass element of the present invention, the dirty gob receiving mold is successively washed and dried to be returned to the gob receiving mold having the clean surface, and the cleaning is repeated. Depending on the method used, a glass gob having a clean surface can be continuously supplied to a precision molding die to continuously obtain an optical glass element having a good surface by a consistent process. Moreover, since the glass gob temperature is maintained at a high temperature, the molding tact can be shortened and the cost of the product can be reduced.
【図1】本発明のガラスゴブ受け型の交換及び洗浄・乾
燥機構を示す縦断面図FIG. 1 is a vertical cross-sectional view showing a glass gob receiving mold replacement, cleaning and drying mechanism of the present invention.
【図2】本発明の精密成形プロセスを示す縦断面図FIG. 2 is a vertical sectional view showing a precision molding process of the present invention.
1 オリフィス 2 ゴブ受け型 3 ガラスゴブ 4,14,15 ヒーター 5 ヒーター挿入部材 6 回転可能な機構 7,12,17 シャッター 8 精密成形室 9 精密成形用下型 10 回転可能な支柱 11 オートハンド 13 ベルトコンベア 16 精密成形用上型 18 光学ガラス素子 19 吸着バンド 20 ガス導入管 21 ガス排出管 1 Orifice 2 Gob-receiving type 3 Glass gob 4, 14, 15 Heater 5 Heater insertion member 6 Rotatable mechanism 7, 12, 17 Shutter 8 Precision molding chamber 9 Precision molding lower mold 10 Rotating support 11 Auto hand 13 Belt conveyor 16 Precision Molding Upper Mold 18 Optical Glass Element 19 Adsorption Band 20 Gas Introducing Pipe 21 Gas Exhausting Pipe
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中居 靖行 東京都大田区下丸子3丁目30番2号 キヤ ノン株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuyuki Nakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.
Claims (8)
させて該ガラスをゴブ受け型で受けて光学ガラス予備成
形体を得、次いでこれをプレス成形して光学ガラス素子
を製造する方法において、該ゴブ受け型が複数個用意さ
れておりこれを所定回数の成形後洗浄して交換する工程
を有し、かつ該ゴブ受け型を反転させて該光学ガラス予
備成形体を精密成形型に落下させる工程、次いで該精密
成形型に載置された該光学ガラス予備成形体をプレス成
形して光学ガラス素子を得る工程を有することを特徴と
する光学ガラス素子の製造方法。1. A method for producing an optical glass element by dropping molten glass from an orifice to receive the glass with a gob-receiving mold and then press-molding the glass to produce an optical glass element. A plurality of receiving molds are prepared and have a step of washing and replacing them after molding a predetermined number of times, and a step of reversing the gob receiving mold and dropping the optical glass preform into a precision molding die, Next, a method for producing an optical glass element, comprising a step of press-molding the optical glass preform placed on the precision molding die to obtain an optical glass element.
水溶液を用い、洗浄液に超音波振動を付加することを特
徴とする請求項1に記載の光学ガラス素子の製造方法。2. The method of manufacturing an optical glass element according to claim 1, wherein an acid aqueous solution is used as the gob-receiving type cleaning method, and ultrasonic vibration is applied to the cleaning solution.
カリの水溶液を用い、洗浄液に超音波振動を付加するこ
とを特徴とする請求項1に記載の光学ガラス素子の製造
方法。3. The method for manufacturing an optical glass element according to claim 1, wherein an alkaline aqueous solution is used as the gob-receiving type cleaning method, and ultrasonic vibration is applied to the cleaning solution.
用い、洗浄液に超音波振動を付加することを特徴とする
請求項1に記載の光学ガラス素子の製造方法。4. The method of manufacturing an optical glass element according to claim 1, wherein water is used as the gob-receiving type cleaning method, and ultrasonic vibration is applied to the cleaning solution.
水溶液及び水を用い、洗浄液に超音波振動を付加するこ
とを特徴とする請求項1に記載の光学ガラス素子の製造
方法。5. The method for producing an optical glass element according to claim 1, wherein an acid aqueous solution and water are used as the gob-receiving type cleaning method, and ultrasonic vibration is applied to the cleaning solution.
カリの水溶液及び水を用い、洗浄液に超音波振動を付加
することを特徴とする請求項1に記載の光学ガラス素子
の製造方法。6. The method of manufacturing an optical glass element according to claim 1, wherein an alkaline aqueous solution and water are used as the gob-receiving type cleaning method, and ultrasonic vibration is applied to the cleaning solution.
溶媒置換及び熱風を用いることを特徴とする請求項1に
記載の光学ガラス素子の製造方法。7. The method for producing an optical glass element according to claim 1, wherein an organic solvent substitution and hot air are used as the gob receiving type drying method.
光学ガラス予備成形体をプレス成形して光学ガラス素子
を得る工程を、非酸化性雰囲気中で実施することを特徴
とする請求項1に記載の光学ガラス素子の製造方法。8. The method according to claim 1, wherein at least the step of press-molding the optical glass preform placed on the precision molding die to obtain an optical glass element is performed in a non-oxidizing atmosphere. A method for producing the optical glass element described.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8023894A JPH07291639A (en) | 1994-04-19 | 1994-04-19 | Production of optical glass element |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8023894A JPH07291639A (en) | 1994-04-19 | 1994-04-19 | Production of optical glass element |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH07291639A true JPH07291639A (en) | 1995-11-07 |
Family
ID=13712759
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8023894A Pending JPH07291639A (en) | 1994-04-19 | 1994-04-19 | Production of optical glass element |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH07291639A (en) |
-
1994
- 1994-04-19 JP JP8023894A patent/JPH07291639A/en active Pending
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