JP2002249327A - Method for forming optical element - Google Patents
Method for forming optical elementInfo
- Publication number
- JP2002249327A JP2002249327A JP2001041924A JP2001041924A JP2002249327A JP 2002249327 A JP2002249327 A JP 2002249327A JP 2001041924 A JP2001041924 A JP 2001041924A JP 2001041924 A JP2001041924 A JP 2001041924A JP 2002249327 A JP2002249327 A JP 2002249327A
- Authority
- JP
- Japan
- Prior art keywords
- glass material
- mold
- pressing
- upper mold
- molding
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
- C03B11/06—Construction of plunger or mould
- C03B11/08—Construction of plunger or mould for making solid articles, e.g. lenses
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/40—Product characteristics
- C03B2215/46—Lenses, e.g. bi-convex
- C03B2215/47—Bi-concave
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/61—Positioning the glass to be pressed with respect to the press dies or press axis
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、加熱されたガラス
素材を、成形型セットを用いて、プレス成形することに
より得られる光学素子の成形方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding an optical element obtained by press-molding a heated glass material using a mold set.
【0002】[0002]
【従来の技術】従来から、研磨工程を必要としないガラ
スレンズの製造方法として、ガラス素材を加熱し、上下
一対の型でプレス成形する方法が行われているが、その
際に、レンズの両面のみならず、外径側面も同時に成形
して、成形後の芯取り工程を省略し、また、レンズ両面
に係わる光軸に対する外径寸法の偏心程度を示す、所
謂、外径偏心精度(同心度)の高いガラス成形品を得る
方法も行われている。2. Description of the Related Art Conventionally, as a method of manufacturing a glass lens which does not require a polishing step, a method of heating a glass material and press-molding the glass material with a pair of upper and lower molds has been used. In addition, the outer diameter side surface is also molded at the same time, so that the centering step after molding is omitted, and the so-called outer diameter eccentricity (concentricity) which indicates the degree of eccentricity of the outer diameter with respect to the optical axis related to both surfaces of the lens. There is also a method for obtaining a glass molded product having a high quality.
【0003】例えば、特開昭62−87425号公報に
は、型閉めした時に形成される、上型、下型および胴型
からなるキャビティ(空間)にて、軟化状態のガラス素
材を加圧するプレス用金型セットにおいて、径の異なる
上下型を使用し、大径側の型の成形面外周部が胴型に突
き当たることで、前記キャビティを形成し、その後、小
径側の型の成形面でガラス素材を加圧し、同心度が良好
で、ばりのないガラスレンズなどの光学素子を成形する
ことが記載されている。For example, Japanese Patent Application Laid-Open No. 62-87425 discloses a press for pressurizing a softened glass material in a cavity (space) formed when a mold is closed and formed by an upper mold, a lower mold and a body mold. In the mold set, the upper and lower dies having different diameters are used, and the molding surface of the large-diameter side abuts against the body mold to form the cavity, and thereafter, the glass is formed on the molding surface of the small-diameter mold. It describes that a material is pressed to form an optical element such as a glass lens having good concentricity and no burrs.
【0004】一方、ガラスレンズを成形する場合、肉厚
精度も、その機能性の上で重要である。そのために、レ
ンズ機能面を転写するための成形面が形成された上下一
対の型が、胴型の貫通穴の両側に摺動自在に挿入される
形で、使用されるプレス成形用金型セット(成形型セッ
ト)において、例えば、上型に、摺動ストロークを規制
する胴型との突き当て部を有し、これにより、ガラス素
材をプレス成形する際の上型のプレス量を規制して、安
定した成形品肉厚を確保することがなされている。On the other hand, when molding a glass lens, the wall thickness accuracy is also important in terms of its functionality. For this purpose, a pair of upper and lower dies having a molding surface for transferring the lens functional surface are slidably inserted into both sides of the through hole of the body die, and a press molding die set to be used. In the (forming mold set), for example, the upper mold has an abutting portion with a barrel mold for regulating a sliding stroke, thereby controlling the amount of press of the upper mold when press-molding a glass material. Therefore, a stable molded product thickness is ensured.
【0005】ただし、この方法では、冷却中にガラス成
形品の収縮で、それに対するプレス圧がかからなくなっ
てしまい、ガラス成形品の形状によっては、光学機能面
にヒケが発生する畏れがある。このため、実質的に押込
み側の規制のない下型を用いて、成形型セットの下側よ
り、冷却中のガラス成形品に補助的に圧力を加える方法
などが案出された。なお、この場合に、型内(キャビテ
ィ内)へのガラス素材の供給や前記型内からのガラス成
形品の取り出しのために、通常、胴型側面に開口部が設
けてある。[0005] However, in this method, due to shrinkage of the glass molded product during cooling, no pressing pressure is applied thereto, and depending on the shape of the glass molded product, sink may occur on the optical function surface. For this reason, a method has been devised in which a lower mold having substantially no restriction on the pushing side is used to supplementarily apply pressure to the glass molded article being cooled from below the mold set. In this case, in order to supply the glass material into the mold (inside the cavity) and take out the glass molded product from the inside of the mold, an opening is usually provided on the side surface of the body mold.
【0006】[0006]
【発明が解決しようとする課題】しかしながら、前記の
ような、ガラス成形品の肉厚精度の良好な方法で、外径
側面も同時に成形しようとする場合、つまり、上型のみ
でガラス素材をプレス変形させる方法では、前述のよう
に、胴型側面に開口部が設けてあり、上型を押し切るこ
とで、上型および下型の各成形面、および側面形成部材
(あるいは胴型)の表面で、キャビティ(空間)を形成
するため、ガラス成形品の形状によっては、上型でガラ
ス素材を押し切る前に、ガラス素材の一部が、前記キャ
ビティからはみ出して、成形品にバリを発生させ、ある
いは上型による押し切りができなくなるという問題点が
残される(図7を参照)。However, in the case where the outer diameter side surface is to be formed simultaneously by the method having good wall thickness accuracy of the glass molded product as described above, that is, the glass material is pressed only by the upper mold. In the method of deforming, as described above, the opening is provided on the side surface of the body die, and the upper die is pushed out so that the molding surfaces of the upper and lower dies and the surface of the side surface forming member (or the body die) are formed. In order to form a cavity (space), depending on the shape of the glass molded product, a part of the glass material may protrude from the cavity before the glass material is pressed off by the upper mold, and generate burrs on the molded product, or There remains a problem that the upper die cannot perform push-off (see FIG. 7).
【0007】そこで、前述の、特開昭62−87425
号公報の発明のように、下型の位置を予め、プレス成形
位置より下げておき、上型が押し切って、密閉空間を形
成した後に、下型をプレス成形位置まで上昇するによ
り、ガラス素材を加圧する方法が検討されたが、この場
合、下型には、摺動ストロークを規制する胴型との突き
当て部が存在しないため、素材容量のバラツキに対応し
て、ガラス成形品の肉厚のバラツキが発生してしまうと
いう問題点があった。[0007] In view of the above, Japanese Patent Application Laid-Open No. 62-87425 describes the above.
As in the invention of Japanese Patent Application Laid-Open Publication No. H10-157, the position of the lower mold is lowered beforehand from the press molding position, and the upper mold is pushed out to form a closed space, and then the lower mold is raised to the press molding position, thereby reducing the glass material. A method of applying pressure was studied, but in this case, the lower mold had no abutting portion with the barrel mold that regulates the sliding stroke. However, there is a problem that the variation occurs.
【0008】そこで、仮に、下型に胴型との突き当て部
を設けた場合、今度は、冷却時に収縮するガラス成形品
へのプレス圧力を加えて置くことができず、ヒケを防止
することができないという問題が生じる。また、下型の
押込み位置を高精度に制御することも考えられるが、サ
イクル的に変化する型温の影響により、プレス軸の寸法
も変化する。このため、数マイクロメートルオーダーで
成形されるガラス成形品について、プレス軸のストロー
クの制御を行うことは現実的ではなく、仮に、できたと
しても、高価な装置が必要となってしまう。[0008] Therefore, if the lower die is provided with an abutting portion with the body die, then it is impossible to apply the pressing pressure to the glass molded product that shrinks at the time of cooling, thereby preventing sinking. The problem that it cannot be done arises. It is also conceivable to control the pressing position of the lower die with high precision, but the size of the press shaft also changes due to the influence of the die temperature that changes in a cycle. For this reason, it is not practical to control the stroke of the press shaft for a glass molded product molded on the order of several micrometers, and even if it could be done, an expensive apparatus would be required.
【0009】また、このように、ガラス素材のプレス成
形を行う前に、ガラス素材を載せた下型を上下方向に移
動する場合、その移動時の振動などにより、下型上のガ
ラス素材が位置ずれてしまう場合がある。もし、位置ず
れを起こすと、密閉空間を構成する側面形成部材の表面
で、プレスされたガラス素材の周囲の動きを抑制し、位
置ずれを修正するとしても、通常のプレス時のガラス粘
度では、位置ずれが完全に修正されることはなく、ずれ
た方にバリなどが発生して、成形に支障をきたすなどの
問題も生じた。In addition, when the lower mold on which the glass material is placed is moved up and down before press molding of the glass material, the glass material on the lower mold is moved due to vibration during the movement. It may shift. If misalignment occurs, on the surface of the side surface forming member constituting the closed space, the movement around the pressed glass material is suppressed, and even if the misalignment is corrected, the glass viscosity during normal pressing, The misalignment was not completely corrected, and burrs and the like were generated on the misaligned side, causing problems such as hindrance to molding.
【0010】本発明は、上記事情に基づいてなされたも
ので、レンズなどの光学素子の両光学機能面に対向する
上下型の成形面とともに、側面形成部材(あるいは胴
型)の表面で、光学素子の外径側面も同時に成形する光
学素子の成形方法において、プレス成形時に、ガラス素
材が型に対して、位置ずれしたり、キャビティ外にはみ
出したりすることがなく、かつ、ガラス成形品の肉厚精
度が良好な光学素子の成形方法を提供することを目的と
する。The present invention has been made on the basis of the above circumstances, and includes an upper surface and a lower surface of a side surface forming member (or a torso type), together with upper and lower mold surfaces facing both optical functional surfaces of an optical element such as a lens. In the molding method of an optical element, which simultaneously molds the outer diameter side surface of the element, the glass material does not displace with respect to the mold at the time of press molding, does not protrude out of the cavity, and the thickness of the glass molded product. An object of the present invention is to provide a method for molding an optical element having good thickness accuracy.
【0011】[0011]
【課題を解決するための手段】(第1の発明)上記目的
を達成するため、本発明では、上型が下降を終了した時
点で、上型、下型の各成形面および側面形成部材の表面
で密閉空間を形成するように、前記上型、下型および側
面形成部材を含む成形型セットを制御して、下型に置か
れた変形可能な加熱ガラス素材を押圧する光学素子の成
形方法において、プレス開始時にまず上型を下降させ、
該上型により前記密閉空間が形成される前にガラス素材
の押圧を開始するが、上型の下降が終了した時点ではガ
ラス素材がまだ変形途中であり、その後、下型を上昇さ
せてガラス素材を押圧し、前記密閉空間内での成形に必
要な残りの変形を完了させることを特徴とする。Means for Solving the Problems (First Invention) In order to achieve the above object, according to the present invention, when the upper mold has finished descending, the molding surfaces of the upper mold and the lower mold and the side surface forming member are formed. An optical element molding method for controlling a mold set including the upper mold, the lower mold, and the side surface forming member so as to form a closed space on the surface, and pressing a deformable heated glass material placed on the lower mold. At the beginning of press, lower the upper die first,
Pressing of the glass material is started before the closed space is formed by the upper mold, but when the lowering of the upper mold is completed, the glass material is still being deformed, and then the lower mold is raised to raise the glass material. To complete the remaining deformation required for molding in the closed space.
【0012】これにより、上型が押し切った時点で形成
される密閉空間は、ガラス素材(成形品)の容量よりも
大きく、ガラスが密閉空間に充填しきっていないため、
ガラス素材の外径が側面形成部材の内径に到達する前
に、密閉空間を形成することが可能となる。また、上型
が押し切った時点で形成される密閉空間の中心高さは、
ガラス素材の厚みよりも小さいため、下型が上昇する前
に、ガラス素材が上下型によって、既に挟まれた状態と
なる。さらに、プレス成形によるガラス素材の変形を、
下型で行う変形以外は、押し切り規制のある上型で行う
ことができる。Thus, the sealed space formed when the upper mold is pushed out is larger than the capacity of the glass material (molded product), and the glass is not completely filled in the sealed space.
The sealed space can be formed before the outer diameter of the glass material reaches the inner diameter of the side surface forming member. Also, the center height of the closed space formed when the upper mold is pushed out,
Since the thickness is smaller than the thickness of the glass material, the glass material is already sandwiched between the upper and lower molds before the lower mold rises. Furthermore, deformation of glass material by press molding,
Except for the deformation performed by the lower die, the upper die having push-off regulation can be performed.
【0013】(第2の発明)また、本発明では、前記発
明の成形方法において、上型でガラス素材を押圧開始す
る時の型温をTu とした時、下型での、押圧開始時の型
の温度TL が、TU−15℃<TL ≦TU であることを
特徴とする。[0013] (second invention) In the present invention, in the molding method of the invention, when the mold temperature at the start pressing the glass material with upper die and a T u, in the lower mold, at the start of pressing temperature T L of the mold, characterized in that a T U -15 ℃ <T L ≦ T U.
【0014】これにより、第1の発明において、下型で
のガラス素材の押圧変形を、より変形が容易な温度範囲
で行うことができる。Thus, in the first aspect of the invention, the pressing and deformation of the glass material with the lower mold can be performed in a temperature range where the deformation is easier.
【0015】(第3の発明)また、本発明では、前記発
明の成形方法において、プレス工程で型の温度を一定に
したまま、上型および下型によるガラス素材の押圧を順
次行い、かつ、プレス工程における下型でのガラス素材
の押圧状態を一旦解除した後に、冷却工程に移り、その
後、型の温度が、プレス工程より15℃以上低くなった
時点で、再度、下型による押圧を行うことを特徴とす
る。(Third invention) In the present invention, in the molding method of the invention, the glass material is sequentially pressed by the upper mold and the lower mold while keeping the temperature of the mold in the pressing step, and After the pressing state of the glass material in the lower mold in the pressing step is once released, the process moves to the cooling step, and then, when the temperature of the mold becomes lower than the pressing step by 15 ° C. or more, the lower mold is pressed again. It is characterized by the following.
【0016】これにより、第1の発明において、下型で
のガラス素材の押圧変形を、必要以上に行うことなく、
かつ冷却中のガラス成形品に補助的にプレス圧を加え続
けることができる。Thus, in the first aspect of the present invention, the pressing and deformation of the glass material with the lower mold can be performed without performing more than necessary.
In addition, the pressing pressure can be continuously applied to the cooled glass molded product.
【0017】(第4の発明)更に、本発明では、前記成
形型セットにおいて、前記密閉空間での上型の押圧によ
る変形後で、ガラス素材の外径が、側面形成部材の内径
以下に留まるように、上型押圧時の下型高さの位置が調
整されていることを特徴とする。(Fourth Invention) Further, in the present invention, in the molding die set, the outer diameter of the glass material remains below the inner diameter of the side surface forming member after the deformation due to the pressing of the upper die in the closed space. As described above, the position of the lower mold height when the upper mold is pressed is adjusted.
【0018】これにより、第1〜3の発明において、上
型押し切り時に密閉空間が形成される状態を維持したま
ま、上型が押し切った時点で形成される密閉空間の中心
高さを変化させることができ、上型が押し切る前に変形
したガラス素材が、側面形成部材の内径より外側にはみ
出さないように、上型によるガラス素材変形量を調整す
ることができる。According to the first to third aspects of the present invention, the height of the center of the sealed space formed when the upper mold is pushed out is changed while maintaining the state in which the sealed space is formed when the upper mold is pushed out. The amount of glass material deformation by the upper mold can be adjusted so that the glass material deformed before the upper mold is pushed off does not protrude outside the inner diameter of the side surface forming member.
【0019】[0019]
【発明の実施の形態】図1〜図3は、本発明の光学素子
の成形方法を、その実施形態において説明するための、
成形型セットの縦断面図であり、図4はそのプロセスを
示すグラフである。また、図5は本発明の他の実施形態
での成形型セットの縦断面図であり、図6はそのプロセ
スを示すグラフである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show a molding method of an optical element according to the present invention.
FIG. 4 is a longitudinal sectional view of a mold set, and FIG. 4 is a graph showing the process. FIG. 5 is a vertical sectional view of a mold set according to another embodiment of the present invention, and FIG. 6 is a graph showing the process.
【0020】(第1の実施形態)図1において、成形型
セットの外殻部を構成する胴型4には、この胴型4の中
心軸を中心にして、胴型内を上下に連通するように、そ
の上下端に貫通穴が形成されている。これら上下の貫通
穴の内、上側の貫通穴には、円柱状に形成された上型部
材1が上下方向に沿って摺動可能で、挿脱自在な状態で
嵌合されている。(First Embodiment) In FIG. 1, a body die 4 constituting an outer shell of a molding die set communicates with the inside of the body die up and down around the center axis of the body die 4. Thus, through holes are formed at the upper and lower ends. Of the upper and lower through holes, the upper die member 1 formed in a columnar shape is fitted in the upper through hole in a vertically slidable and slidable manner.
【0021】上型部材1の上端部には、円板状のフラン
ジ部1cが形成されている。そして、このフランジ部1
cの下面がスペーサ11を介して胴型4の上面に上方か
ら当接することにより、上型部材1は、それ以上、下方
に移動することを阻止され、下方へのプレスストローク
が規定されている。ただし、後述のように、上型部材1
が側面形成部材3と当接する場合には、この当接より、
上型部材1の、下方へのプレスストロークを規定するこ
とができる。その場合は、フランジ部1cによる上型部
材1の下方へのプレスストスロークの規定は、補助的な
ものとなる。At the upper end of the upper die member 1, a disk-shaped flange portion 1c is formed. And this flange part 1
When the lower surface of c is in contact with the upper surface of the barrel mold 4 from above via the spacer 11, the upper mold member 1 is prevented from moving further downward, and the downward press stroke is defined. . However, as described later, the upper mold member 1
Abuts on the side surface forming member 3 from this abutment.
The downward press stroke of the upper mold member 1 can be defined. In such a case, the provision of the press stroke below the upper die member 1 by the flange portion 1c is auxiliary.
【0022】なお、どちらを補助的な方法とするかは設
計者の意図にもよるが、今回は、上型部材1と側面形成
部材3とが、より密着する方法である、後者による方法
とした。It should be noted that which of the auxiliary methods depends on the intention of the designer, but this time, the upper mold member 1 and the side surface forming member 3 are more closely contacted with each other. did.
【0023】また、上型部材1の下面中央には、ガラス
素材6を押圧して、その表面に所望の形状を転写して、
ガラス成形品である光学素子の光学機能面を形成するた
めの成形面1aが形成されている。さらに、上型部材1
の下面外周部には、上型部材1が押し切った際に、側面
形成部材3の上端周縁と当接して、下型部材2、側面形
成部材3とともに密閉空間を形成させ、また、上型部材
1と側面形成部材3の軸ずれを修正するために、後述す
るような、傾斜した当接面1bが形成されている。Further, a glass material 6 is pressed at the center of the lower surface of the upper mold member 1 to transfer a desired shape to the surface thereof.
A molding surface 1a for forming an optical function surface of an optical element which is a glass molded product is formed. Further, the upper mold member 1
When the upper die member 1 is pushed out, the upper die member comes into contact with the upper peripheral edge of the side surface forming member 3 to form a closed space together with the lower die member 2 and the side surface forming member 3. An inclined contact surface 1b, as described later, is formed to correct the axial deviation between the first and side surface forming members 3.
【0024】なお、上型部材1の上方には、ガラス素材
6に印加するプレス圧を発生させるための、駆動源及び
プレス圧を伝える上軸など(いずれも図示せず)が配置
されており、この駆動源が、上軸を介して下方に向けて
押し出し動作されることにより、ガラス素材6にプレス
圧が印加されるようになっている。A drive source for generating a press pressure applied to the glass material 6 and an upper shaft for transmitting the press pressure (both not shown) are disposed above the upper mold member 1. When the drive source is pushed downward via the upper shaft, a pressing pressure is applied to the glass material 6.
【0025】また、胴型4の上部には、上型部材1を加
熱するためのヒータ7が内設され、上型部材1には、成
形面1a近傍の温度を測定するためのセンサー(図示せ
ず)が設置されており、さらに、N2 ガス供給源よりN
2 噴出管を通して(いずれも図示せず)、上型部材1を
冷却するようにしてある。A heater 7 for heating the upper mold member 1 is provided in the upper part of the body mold 4, and a sensor for measuring the temperature near the molding surface 1a (see FIG. (Not shown), and N 2 gas supply source
The upper mold member 1 is cooled through two jet pipes (both not shown).
【0026】一方、胴型4の下側の貫通穴には、リング
状に形成された側面形成部材3が、嵌合した状態で挿装
されており、さらに、側面形成部材3の中心軸を中心と
して形成された貫通穴には、円柱状に形成された下型部
材2が、上下方向に沿って摺動可能に挿入された状態
で、嵌合されている。また、側面形成部材3の上面に
は、前述のように、上型部材1の当接面1bに当接する
ための当接面3bが形成されている。On the other hand, a ring-shaped side surface forming member 3 is inserted into the lower through hole of the body mold 4 in a fitted state. A lower mold member 2 formed in a columnar shape is fitted into the through hole formed as the center while being slidably inserted in the vertical direction. Further, on the upper surface of the side surface forming member 3, as described above, the contact surface 3b for contacting the contact surface 1b of the upper die member 1 is formed.
【0027】下型部材2の下面は、胴型4が載置されて
いる支持基板5の上面に、スペーサ12を介して当接し
ていて、この支持基板5により、上型部材1からガラス
素材6を介して、下型部材2に伝達される下方へのプレ
ス圧を受けるように構成されている。また、下型部材2
の上面には、ガラス素材6の下面に所望の形状を転写し
て、成形される光学素子の光学機能面を形成するための
成形面2aが形成されている。なお、成形品16の厚み
は、前述のように、上型部材1が側面形成部材3に当接
することにより規定され、成形する毎に成形品16の厚
みが変化しないようになされている。The lower surface of the lower mold member 2 is in contact with the upper surface of a support substrate 5 on which the body mold 4 is mounted via a spacer 12. It is configured to receive a downward pressing pressure transmitted to the lower mold member 2 via the lower die member 6. Also, the lower mold member 2
A molding surface 2a for transferring a desired shape to the lower surface of the glass material 6 to form an optical functional surface of an optical element to be molded is formed on the upper surface of the glass material 6. As described above, the thickness of the molded product 16 is defined by the contact of the upper die member 1 with the side surface forming member 3 so that the thickness of the molded product 16 does not change every time molding is performed.
【0028】また、この実施の形態では、上型部材の当
接面1bと側面形成部材3の当接面3bとは、それぞれ
の中心軸に対して精度良く、かつ、対称な形状に形成さ
れていて、お互いが密着できる形状となっている。例え
ば、ここでは、当接面1bが上型部材1の成形面1aの
延長で凸面となっており、当接面3bも実質的に同じ曲
率の凹面となっているが、当接面1bがテーパー面であ
れば、当接面3bも実質的に同じ傾斜のテーパー面とし
てもよい。さらに、上型部材1と側面形成部材3の軸ず
れが問題とならないような時には、当接面1bと当接面
3bが軸線方向と直交する水平面であって、互いに当接
するようにしてもよい。Further, in this embodiment, the contact surface 1b of the upper mold member and the contact surface 3b of the side surface forming member 3 are formed in symmetrical shapes with high precision with respect to their respective central axes. So that they can be in close contact with each other. For example, here, the contact surface 1b is a convex surface as an extension of the molding surface 1a of the upper mold member 1, and the contact surface 3b is also a concave surface having substantially the same curvature. If it is a tapered surface, the contact surface 3b may be a tapered surface having substantially the same inclination. Furthermore, when the axial displacement between the upper mold member 1 and the side surface forming member 3 does not cause a problem, the contact surface 1b and the contact surface 3b may be a horizontal plane orthogonal to the axial direction, and may contact each other. .
【0029】また、下型部材2の下部には、駆動源とこ
れに接続した下軸(何れも図示せず)が設置されてお
り、この下軸が上方に向けて押し出し動作することによ
り、支持基板5の貫通穴5aを通り、スペーサ12を介
して、下型部材2の下面に作用する。このスペーサ12
は、上型部材1が押し切った時点で形成される密閉空間
の中心高さを変えて、この時のガラス素材6の変形量を
調整するとともに、最終形状の成形品16の厚みを調整
するものであり、この密閉空間の中心高さが、ガラス素
材6の厚みよりも小さく、最終形状の成形品16の厚み
よりも大きくなるようにしておく。A drive source and a lower shaft (both not shown) connected to the drive source are installed below the lower die member 2. The lower shaft is pushed upward to perform a pushing operation. It passes through the through hole 5 a of the support substrate 5 and acts on the lower surface of the lower mold member 2 via the spacer 12. This spacer 12
Is to change the height of the center of the closed space formed when the upper mold member 1 is pushed out, to adjust the deformation amount of the glass material 6 at this time, and to adjust the thickness of the molded product 16 having the final shape. The height of the center of this closed space is set to be smaller than the thickness of the glass material 6 and larger than the thickness of the molded article 16 having the final shape.
【0030】このようにして、上下から押圧された成形
品16は、一定の厚みも維持する。このためには、バリ
発生を回避する意味でも、光学機能面を転写する範囲外
で、側面形成部材3の表面と各成形面1a、2aとが接
するコーナー部分に、ガラス素材6の分量誤差を吸収す
る空隙が残される工夫が必要である(図示せず)。Thus, the molded product 16 pressed from above and below maintains a constant thickness. For this reason, even in the sense of avoiding the occurrence of burrs, the amount error of the glass material 6 is reduced at a corner portion where the surface of the side surface forming member 3 and each molding surface 1a, 2a are in contact with each other outside the range where the optical function surface is transferred. It is necessary to devise a way to leave a gap to be absorbed (not shown).
【0031】また、胴型4あるいは側面形成部材3と当
接することで下方へのプレスストロークが規定されてい
る上型部材1でガラス素材6を押圧変形する方が、胴型
4あるいは側面形成部材3との当接部を実質的に持たな
い下型部材2でガラス素材6を押圧変形するより、成形
品16の厚みバラツキを少なくできるため、下型部材2
での押圧変形量をできるだけ少なくする方がよく、その
ためには、上型部材1で押し切った時点で、ガラス素材
6がはみ出すことなく、密閉空間を形成できる最大の、
上型部材1での変形量となるように設定することが望ま
しい。その目安としては、上型部材1の押圧による変形
後のガラス素材6の外径が、側面形成部材3の内径よ
り、若干小さくなるように設定する(図2を参照)。It is more preferable to press and deform the glass material 6 with the upper mold member 1 whose downward press stroke is defined by coming into contact with the body mold 4 or the side surface forming member 3. The thickness variation of the molded product 16 can be reduced as compared with the case where the glass material 6 is pressed and deformed by the lower mold member 2 having substantially no contact portion with the lower mold member 3.
It is better to reduce the amount of deformation by pressing as much as possible. For that purpose, when the glass material 6 is pushed out by the upper mold member 1, the maximum that can form a closed space without protruding the glass material 6 is obtained.
It is desirable to set such that the deformation amount of the upper mold member 1 is obtained. As a guide, the outer diameter of the glass material 6 after being deformed by the pressing of the upper mold member 1 is set to be slightly smaller than the inner diameter of the side surface forming member 3 (see FIG. 2).
【0032】なお、下型部材2の下部の駆動源は、プレ
ス工程で上型部材1がガラス素材6を押圧変形させた後
に、プレス圧を下型部材2に印加して、ガラス素材6を
押圧変形させるためのものであり、また、押圧変形動作
が終了した後の冷却過程においても、プレス圧を下型部
材2に印加して、成形品16の面や形状が崩れるのを防
止するためのものである。The drive source below the lower mold member 2 applies a pressing pressure to the lower mold member 2 after the upper mold member 1 presses and deforms the glass material 6 in the pressing step, and In order to prevent the surface and shape of the molded product 16 from being deformed, the pressing force is applied to the lower mold member 2 even in a cooling process after the pressing deformation operation is completed. belongs to.
【0033】また、胴型4の下部には、下型部材2およ
び側面形成部材3を加熱するためのヒータ8が内設さ
れ、下型部材2には、成形面2a近傍の温度を測定する
ためのセンサー(図示せず)が設置されており、さら
に、N2 ガス供給源よりN2 噴出管(何れも図示せず)
を通して下型部材2を冷却するようにしてある。A heater 8 for heating the lower mold member 2 and the side surface forming member 3 is provided below the body mold 4, and the temperature of the lower mold member 2 near the molding surface 2a is measured. (Not shown) are installed, and an N 2 ejection pipe (neither is shown) from a N 2 gas supply source.
To cool the lower mold member 2.
【0034】胴型4の側面には、開口部4aが形成され
ており、この開口部4aより搬送部材(例えば、真空吸
着ハンド:図示せず)を介して、成形型内へのガラス素
材6の供給や、成形品16の成形型外への搬出を行う。
また、この開口部4aより加熱部材(図示せず)が挿入
され、ガラス素材6の加熱を行う。An opening 4a is formed in a side surface of the body mold 4, and the glass material 6 is introduced into the molding die from the opening 4a via a conveying member (for example, a vacuum suction hand: not shown). Is supplied and the molded product 16 is carried out of the molding die.
A heating member (not shown) is inserted through the opening 4 a to heat the glass material 6.
【0035】なお、前述の胴型4に内設されたヒータ
7、8は、それぞれ独立した温度調節機(図示せず)に
接続され、それぞれ、上型部材1および下型部材2に設
置されたセンサーにより検出された温度に基づいて制御
される。The heaters 7 and 8 provided in the body mold 4 are connected to independent temperature controllers (not shown), and are installed on the upper mold member 1 and the lower mold member 2, respectively. The temperature is controlled based on the temperature detected by the sensor.
【0036】次に、上記のように構成された成形型を用
いて、レンズを成形する手順について説明する。まず、
上型部材1側の駆動源を引き込み動作させて、上型部材
1を胴型4に対して上方にスライドさせ、下型部材2か
ら逃がしておく。この状態において、胴型4の開口部4
aより、前記搬送部材を介して、ガラス素材6を下型部
材2の成形面2a上に供給する。なお、上型部材1およ
び下型部材2は、所定の成形条件に対応した温度に調整
されている。Next, a procedure for molding a lens using the molding die configured as described above will be described. First,
The drive source on the upper mold member 1 side is pulled in, and the upper mold member 1 is slid upward with respect to the body mold 4 to escape from the lower mold member 2. In this state, the opening 4
a, the glass material 6 is supplied onto the molding surface 2a of the lower mold member 2 via the conveying member. The upper mold member 1 and the lower mold member 2 are adjusted to a temperature corresponding to a predetermined molding condition.
【0037】ガラス素材6が下型部材2の成形面2a上
に供給されると、胴型4の開口部4aより前記加熱部材
が挿入され、ガラス素材6の加熱を行う。なお、ガラス
素材6は、型外であらかじめ加熱され、これを型内に供
給してもよい。When the glass material 6 is supplied onto the molding surface 2 a of the lower mold member 2, the heating member is inserted through the opening 4 a of the body mold 4 to heat the glass material 6. Note that the glass material 6 may be heated in advance outside the mold and supplied into the mold.
【0038】上型部材1、下型部材2及びガラス素材6
が所定の温度に到達すると、前記加熱部材が胴型4の外
側に退避し、直ちに、上型部材1側の駆動源を押し出し
動作させて、密閉空間を形成する前に、ガラス素材6の
上面に、上型部材1の成形面1aを当接させ、ガラス素
材6にプレス圧を印加させて、押圧成形を行う。Upper mold member 1, Lower mold member 2, and glass material 6
When the temperature reaches a predetermined temperature, the heating member retracts to the outside of the barrel mold 4 and immediately pushes out the drive source on the upper mold member 1 side to form an enclosed space. Then, the molding surface 1a of the upper mold member 1 is brought into contact with the glass material 6, and a press pressure is applied to the glass material 6 to perform press molding.
【0039】上型部材1の当接面1bが側面形成部材3
の当接面3bに当接し、上型部材1と側面形成部材3と
の軸ずれが修正される時、下型部材2、側面形成部材3
とにより密閉空間を形成するとともに、上型部材1によ
る、ガラス素材6の変形動作が終了する。The contact surface 1b of the upper mold member 1 is
When the axial displacement between the upper mold member 1 and the side surface forming member 3 is corrected by contacting the contact surface 3b, the lower mold member 2 and the side surface forming member 3
Thus, a sealed space is formed, and the deformation operation of the glass material 6 by the upper mold member 1 is completed.
【0040】次に、下型部材2側の駆動源を押し出し動
作させて、下型部材2の成形面2aからガラス素材6の
下面にプレス圧を印加させ、密閉空間内にて、変形途中
であったガラス素材6の押圧を、一定時間行い、その
後、変形動作を完了した時点で、ガラス素材6の下面側
のプレス圧を一旦解除する。この時、下型部材2の成形
面2aがガラス素材6の下面に接触する程度のごく小さ
な圧力をかけておいてもよい。Next, the drive source on the lower mold member 2 side is pushed out to apply a pressing pressure from the molding surface 2a of the lower mold member 2 to the lower surface of the glass material 6, and in the enclosed space, during the deformation. Pressing of the existing glass material 6 is performed for a certain period of time, and thereafter, when the deformation operation is completed, the pressing pressure on the lower surface side of the glass material 6 is temporarily released. At this time, a very small pressure may be applied so that the molding surface 2a of the lower mold member 2 contacts the lower surface of the glass material 6.
【0041】また、下型部材2によるガラス素材6の押
圧時間は、密閉空間内にガラスが完全に充填するよりも
短くなるように設定する。つまり、密閉空間の容量がガ
ラス素材6の容量より若干大きくなるところで、下型部
材2による押し込みを停止させる。即ち、この時の成形
品の厚みが所望の寸法となるように、ガラス素材6の容
量をあらかじめ調整しておく。なお、上型部材1でのガ
ラス素材6の変形動作終了の確認は、前記上軸の動きを
センサーで検知することで、行う。The pressing time of the glass material 6 by the lower mold member 2 is set so as to be shorter than the time when the glass is completely filled in the closed space. That is, when the capacity of the sealed space becomes slightly larger than the capacity of the glass material 6, the pushing by the lower mold member 2 is stopped. That is, the capacity of the glass material 6 is adjusted in advance so that the thickness of the molded product at this time becomes a desired dimension. The end of the deformation operation of the glass material 6 in the upper die member 1 is confirmed by detecting the movement of the upper shaft with a sensor.
【0042】その後、冷却工程に移り、上型部材1と下
型部材2はそれぞれN2 噴出管(図示せず)を通して供
給されるN2 ガスによって冷却が促進される。そして、
型がプレス変形時より15℃より低い所定の温度まで冷
却されたとき、成形品16の面形状が崩れないように、
再度下型部材2側の駆動源を押し出し動作させ、下型部
材2により成形品16の下方から圧力を印加する。その
まま冷却を続け、さらに所定の温度まで到達したとき
に、下型部材2側の駆動源を引き込み動作させて、下型
部材2による圧力を解除する。Thereafter, the process proceeds to a cooling step, in which the upper mold member 1 and the lower mold member 2 are each cooled by N 2 gas supplied through an N 2 jet pipe (not shown). And
When the mold is cooled to a predetermined temperature lower than 15 ° C. than at the time of press deformation, so that the surface shape of the molded product 16 does not collapse,
The drive source on the lower mold member 2 side is again pushed out, and pressure is applied from below the molded product 16 by the lower mold member 2. The cooling is continued as it is, and when the temperature reaches a predetermined temperature, the drive source of the lower mold member 2 is pulled in to release the pressure by the lower mold member 2.
【0043】その後、さらに冷却を行い、所定の温度ま
で到達したときに、上型部材1側の駆動源を引き込み動
作させて、上型部材1を上方に移動させ、搬送部材(図
示せず)を介して、成形品16を胴型4の開口部4aよ
り外部に取り出させる。この時、再度、下型部材2側の
駆動源を押し出し動作させて、下型を上昇させ、側面形
成部材3に対して成形品16を突き出し、成形品16を
取り出させてもよい。Thereafter, further cooling is performed, and when the temperature reaches a predetermined temperature, the drive source of the upper mold member 1 is pulled in to move the upper mold member 1 upward, and a transport member (not shown) The molded product 16 is taken out from the opening 4a of the body mold 4 through. At this time, the lower die 2 may be again pushed out by operating the drive source on the side of the lower die member 2 to raise the lower die, and the molded product 16 may be protruded from the side surface forming member 3 to take out the molded product 16.
【0044】次に、カメラに使用されるレンズを例に詳
細な成形条件の説明を行うことにする。ガラス素材は、
図1に示すような、外径φ:11mm、中心肉厚:6.
5mmの形状で、ランタン系ガラス(屈折率1.68、
アッベ数54.9、転移点562℃)を使用し、下面側
凹非球面(近似R30mm)、上面側凹R30で外径
φ:15mm、中心肉厚:1.5mmの両凹レンズを成
形する。Next, the molding conditions will be described in detail using a lens used in a camera as an example. The glass material is
Outer diameter φ: 11 mm, center thickness: 6, as shown in FIG.
5 mm shape, lanthanum glass (refractive index 1.68,
Using an Abbe number of 54.9 and a transition point of 562 ° C.), a biconcave lens having an outer diameter φ of 15 mm and a center thickness of 1.5 mm is formed with a lower concave aspheric surface (approximately R30 mm) and an upper concave R30.
【0045】まず、上型部材1および下型部材2の温度
が530℃(1014.9 ポアズ相当)のときにガラス素
材6を投入し、前述のように、加熱部材によりガラス素
材6の加熱を行う。この状態で上型部材1および下型部
材2の温度が625℃(10 9.0 ポアズ相当)になり、
かつガラス素材6の温度も625℃(109.0 ポアズ相
当)になった時点で、上型部材1側の駆動源を3100
N(ニュートン)の力で押し出し動作(プレス動作)を
開始し、上型部材1により、ガラス素材6の全変形量の
ほぼ90%の量を押込んだ時点で(前述のように、下型
部材2側のスペーサ12の厚みは調整してある)、上型
部材1の当接面1bが側面形成部材3の当接面3bに突
き当たり、この突き当てにより下型部材2、側面形成部
材3とともに密閉空間を形成して、上型の押し込み動作
が終了するが、ガラス素材6の側面はまだ側面形成部材
3の内径には接していない。また、突き当てた状態の上
型部材1の圧力はそのまま保持しておく(図2の状
態)。First, the temperature of the upper mold member 1 and the lower mold member 2
Is 530 ° C (1014.9 Poise)
Material 6 is charged, and the glass member is heated by the heating member as described above.
The material 6 is heated. In this state, the upper mold member 1 and the lower mold portion
The temperature of material 2 is 625 ° C (10 9.0 Poise equivalent)
The temperature of the glass material 6 is also 625 ° C. (109.0 Poise phase
At this point, the drive source on the upper mold member 1 side is changed to 3100
Extrusion operation (press operation) with N (Newton) force
Starting, the upper mold member 1 determines the total deformation amount of the glass material 6.
At the point when almost 90% of the amount is pushed (as described above, the lower mold
The thickness of the spacer 12 on the member 2 side is adjusted), the upper die
The contact surface 1b of the member 1 projects from the contact surface 3b of the side surface forming member 3.
The lower die member 2 and the side surface forming portion
Forming a closed space with the material 3 and pushing the upper mold
Is finished, but the side of the glass material 6 is still a side forming member
3 does not touch the inner diameter. Also, on the bumped state
The pressure of the mold member 1 is kept as it is (as shown in FIG. 2).
state).
【0046】そして、上軸の動きが毎秒1μm(マイク
ロメートル)以下となった時点をセンサーで感知して、
上型の押し込み動作終了とみなし、次に、上型部材1お
よび下型部材2の温度を変えることなく、下型部材2側
の駆動源を2200N(ニュートン)の力で押し出し動
作させて、下型部材2によりガラス素材6に変形を加
え、全変形量の残りほぼ10%の量を数秒間かけて押し
込む(図3の状態)。The sensor detects when the movement of the upper axis becomes 1 μm (micrometer) or less per second,
The pushing operation of the upper mold member is considered to be completed, and then the drive source of the lower mold member 2 is pushed out with a force of 2200 N (Newton) without changing the temperatures of the upper mold member 1 and the lower mold member 2, and The glass material 6 is deformed by the mold member 2, and the remaining amount of about 10% of the total deformation is pushed in over several seconds (the state of FIG. 3).
【0047】その後、下型部材2側の駆動源の圧力を下
げ、下型部材2によるガラス素材6への実質的な圧力を
解除して、冷却工程へ移行する。冷却を開始して、まず
605℃(1010.0ポアズ相当)になった時点で、上型
部材1にかかる圧力をそのままとし、下型部材2によ
り、成形品16に2200N(ニュートン)の力を加え
る。次に、この状態のまま冷却を続け、540℃(10
14.1 ポアズ相当)になった時点で下型部材2の圧力も
解除する。その後、530℃(1014.9 ポアズ相当)
まで冷却し、上型部材1を上昇させて型を開き、成形品
16の取出しを行う。Thereafter, the pressure of the drive source on the lower mold member 2 side is reduced, the substantial pressure on the glass material 6 by the lower mold member 2 is released, and the process proceeds to a cooling step. When cooling is started, first, when the temperature reaches 605 ° C. (equivalent to 10 10.0 poise), the pressure applied to the upper mold member 1 is kept as it is, and a force of 2200 N (Newton) is applied to the molded product 16 by the lower mold member 2. . Next, cooling is continued in this state, and the temperature is kept at 540 ° C. (10 ° C.).
When the pressure reaches 14.1 poise, the pressure of the lower mold member 2 is also released. Then 530 ° C (equivalent to 10 14.9 poise)
Then, the upper mold member 1 is raised to open the mold, and the molded product 16 is taken out.
【0048】上記のような一連の動作により、レンズの
成形を実際に500ショット行ったところ、面精度はも
ちろん、肉厚のばらつきも10μm(マイクロメート
ル)程度に収まり、良好な精度の成形品を得ることがで
きた。また、ガラス素材6の位置ずれや密閉空間からは
み出すようなこともなく、成形を行うことができた。When a series of operations as described above actually performed 500 shots of the lens, not only the surface accuracy but also the variation in thickness was within about 10 μm (micrometer), and a molded article with good accuracy was obtained. I got it. In addition, molding could be performed without any displacement of the glass material 6 or protruding from the closed space.
【0049】(第2の実施形態)この実施の形態では、
図5において、上型部材21、下型部材22、側面形成
部材23が両凸レンズを成形する形状になっている以
外、型の構成については、第1の実施形態の場合と同様
であるため、その詳細な説明は省略する。(Second Embodiment) In this embodiment,
In FIG. 5, the configuration of the mold is the same as that of the first embodiment, except that the upper mold member 21, the lower mold member 22, and the side surface forming member 23 are shaped to form a biconvex lens. Detailed description is omitted.
【0050】この場合も、上型部材21の当接面21b
は成形面21aから同じ曲率で延長した凹面形状であ
り、これと接する側面形成部材23の当接面23bは同
じ曲率の凸面形状となっていて、当接面21bと当接面
23bとが当接して密着することにより、上型部材21
と側面形成部材23の軸ずれを修正するとともに、上型
部材21、下型部材22、側面形成部材23とで密閉空
間を形成する。Also in this case, the contact surface 21b of the upper mold member 21
Has a concave shape extending at the same curvature from the molding surface 21a, and the contact surface 23b of the side surface forming member 23 in contact therewith has a convex shape with the same curvature, and the contact surface 21b and the contact surface 23b are in contact with each other. The upper and lower members 21
In addition to correcting the axial deviation of the side forming member 23 and the upper forming member 21, the lower forming member 22, and the side forming member 23, a closed space is formed.
【0051】また、下型が凹面形状の場合、下型に置か
れるガラス素材の位置が低くなり、上軸でのガラス素材
の変形量が比較的大きくても、はみ出す割合が低くなる
ため、上型部材21でのガラス素材の変形量が大きくな
るように、下型部材22は、それに対応するスペーサ3
2で、位置調整しておく。Further, when the lower mold has a concave shape, the position of the glass material placed on the lower mold is lowered, and even if the amount of deformation of the glass material on the upper shaft is relatively large, the rate of protrusion is reduced. The lower mold member 22 is attached to the corresponding spacer 3 so that the amount of deformation of the glass material in the mold member 21 increases.
In 2, adjust the position.
【0052】次に、上記のように構成された成形型によ
りレンズを成形する手順について説明する。ガラス素材
を型内に供給し、所定の温度に加熱し、上型部材21で
ガラス素材を押し込み、上型部材21の当接面21bが
側面形成部材23の当接面23bに当接することで、上
型部材21でのガラス素材の変形動作を終了する。以上
は、第1の実施形態と同様である。Next, a procedure for molding a lens using the mold having the above-described configuration will be described. The glass material is supplied into the mold, heated to a predetermined temperature, the glass material is pushed in by the upper mold member 21, and the contact surface 21 b of the upper mold member 21 contacts the contact surface 23 b of the side surface forming member 23. Then, the deformation operation of the glass material in the upper mold member 21 is completed. The above is the same as in the first embodiment.
【0053】その後、冷却を開始し、まず、プレス時の
型の温度から15℃以内の所定の温度となったときに、
下型部材22側の駆動源を押し込み動作させて、下型部
材22に圧力を印加し、ガラス素材の残りの変形量を変
形させて行くが、冷却が進むにつれ、ガラス粘度の上昇
とともにその変形量が減少し、その後は、実質的に保持
するだけの状態となる。After that, cooling is started, and when the temperature of the mold at the time of pressing reaches a predetermined temperature within 15 ° C.
The drive source on the lower mold member 22 side is pushed in to apply pressure to the lower mold member 22 to deform the remaining amount of deformation of the glass material. The amount is reduced, after which it is in a state of substantially only holding.
【0054】つまり、ガラス素材を十分に変形させるに
は、プレス時の型の温度から15℃以内が望ましく、必
要な変形量が小さくてすむ場合は、下型部材22での押
し込みを比較的低い温度から開始する。さらに、冷却中
の、成形品16の面形状の崩れを防ぐために、下型部材
22による変形後の、成形品26への圧力を保持したま
ま冷却を続ける。そして、所定の温度まで到達したとき
に、下型部材22側の駆動源を引き込み動作させて、下
型部材22による圧力を解除する。これ以降の成形品の
取り出しまでの工程は、第1の実施形態の場合と同様で
あるから、その説明は省略する。That is, in order to sufficiently deform the glass material, the temperature is preferably within 15 ° C. from the temperature of the mold at the time of pressing, and when the required amount of deformation is small, the indentation by the lower mold member 22 is relatively low. Start with temperature. Further, in order to prevent the surface shape of the molded product 16 from being collapsed during the cooling, the cooling is continued while maintaining the pressure on the molded product 26 after the deformation by the lower mold member 22. Then, when the temperature reaches a predetermined temperature, the drive source on the lower mold member 22 side is pulled in to release the pressure by the lower mold member 22. The subsequent steps up to the removal of the molded product are the same as those in the first embodiment, and a description thereof will be omitted.
【0055】ここで、また、第1の実施形態と同様、カ
メラに使用されるレンズを例に、詳細な成形条件の説明
を行うことにする。ここでは、第1の実施形態と同様、
ガラス素材に外径φ:10.5mm、中心肉厚:7.0
mmの形状で、重クラウンガラス(屈折率1.58、ア
ッベ数59.4、転移点506℃)を使用し、下面側凸
非球面(近似R18)、上面側凸R:18mmで外径
φ:14mm、中心肉厚:4.0mmの両凸レンズを成
形する。Here, similarly to the first embodiment, the molding conditions will be described in detail using a lens used in a camera as an example. Here, as in the first embodiment,
Outer diameter φ: 10.5 mm, center thickness: 7.0
mm, heavy crown glass (refractive index 1.58, Abbe number 59.4, transition point 506 ° C.), lower convex aspheric surface (approximate R18), upper convex R: 18 mm, outer diameter φ : A biconvex lens having a thickness of 14 mm and a center thickness of 4.0 mm.
【0056】まず、上型部材21および下型部材22の
温度が470℃(1015.2 ポアズ相当)のときにガラ
ス素材を投入し、前述のように加熱部材によりガラス素
材の加熱を行う。そして、この状態で上型部材21およ
び下型部材22の温度が580℃(109.0 ポアズ相
当)になり、かつガラス素材の温度も580℃(109.
0ポアズ相当)になった時点で、上型部材21側の駆動
源を3400N(ニュートン)の力で押し出し動作させ
てプレス動作を開始し、上型部材21によりガラス素材
の全変形量のほぼ95%の量を押込んだ時点で(前述の
ように、下型部材22側のスペーサ32の厚みが調整し
てある)、上型部材21の当接面21bが側面形成部材
23の当接面23bに突き当たり、この突き当てにより
下型部材22、側面形成部材23とともに密閉空間を形
成して、上型の押し込み動作が終了するが、やはり、ガ
ラス素材の側面は、まだ側面形成部材23の内径には接
していない。また、突き当てた状態の上型部材21の圧
力はそのまま保持しておく。First, when the temperature of the upper mold member 21 and the lower mold member 22 is 470 ° C. (corresponding to 10 15.2 poise), a glass material is charged, and the glass material is heated by the heating member as described above. Then, the temperature of the upper mold member 21 and a lower mold member 22 in this state is turned 580 ° C. (10 9.0 poises equivalent), and the temperature of the glass material also 580 ℃ (10 9.
( Equivalent to 0 poise), the driving source on the upper mold member 21 side is pushed out with a force of 3400 N (Newton) to start the pressing operation, and the upper mold member 21 starts the pressing operation. % (When the thickness of the spacer 32 on the lower mold member 22 side is adjusted as described above), the contact surface 21b of the upper mold member 21 is brought into contact with the contact surface of the side surface forming member 23. 23b, and the abutment forms an enclosed space together with the lower mold member 22 and the side surface forming member 23, thereby completing the pushing operation of the upper mold. However, the side surface of the glass material still has the inner diameter of the side surface forming member 23. Not in contact with The pressure of the upper mold member 21 in the abutted state is maintained as it is.
【0057】次に、冷却を開始し、まず570℃(10
9.4 ポアズ相当)になった時点で、上型部材21にかか
る圧力はそのままとし、下型部材22側の駆動源を25
00N(ニュートン)の力で押し出し動作させて、下型
部材22によりガラス素材に変形を加え、全変形量の残
りほぼ5%の量を押し込んで行く(図5の状態)。Next, cooling was started, and first, cooling was performed at 570 ° C. (10 ° C.).
( Equivalent to 9.4 poise), the pressure applied to the upper mold member 21 is kept as it is, and the drive source of the lower mold member 22 is changed to 25
The glass material is deformed by the lower die member 22 by pushing out with a force of 00 N (Newton), and approximately 5% of the total amount of deformation is pushed in (the state of FIG. 5).
【0058】この状態のまま冷却し、560℃(10
9.8 ポアズ相当)を越えて冷えて行くと、だんだんと変
形量は減少する。そして、変形を終了した成形品26を
下型部材22により保持した状態となる。さらに、この
状態のまま冷却を続けて、490℃(1013.5 ポアズ
相当)になった時点で、下型部材22の圧力を解除し、
その後に、470℃(1015.2 ポアズ相当)まで冷却
して成形品26の取り出しを行う。In this state, the system is cooled and cooled to 560 ° C. (10 ° C.).
As it cools beyond 9.8 poise, the amount of deformation gradually decreases. Then, the deformed molded product 26 is held by the lower mold member 22. Further, cooling is continued in this state, and when the temperature reaches 490 ° C. (corresponding to 10 13.5 poise), the pressure of the lower mold member 22 is released,
Thereafter, the molded product 26 is taken out by cooling to 470 ° C. (corresponding to 10 15.2 poise).
【0059】上記のような一連の動作により、レンズの
成形を実際に500ショット行ったところ、面精度はも
ちろん、肉厚のばらつきも8μm(マイクロメートル)
以内に収まっており、良好な精度の成形品を得ることが
できた。また、この場合も、ガラス素材の位置ずれや密
閉空間からのはみ出しもなく、成形することができた。When a series of operations as described above actually performed 500 shots of the lens, not only the surface accuracy but also the thickness variation was 8 μm (micrometer).
Within the range, a molded article with good accuracy could be obtained. Also in this case, molding could be performed without displacement of the glass material or protrusion from the closed space.
【0060】このように、上型部材での変形量が大きく
ても、はみ出すことのない形状の場合は、下型での変形
量を小さくすることにより、肉厚ばらつきについての精
度をさらに向上することができる。As described above, in the case of a shape that does not protrude even if the amount of deformation in the upper mold member is large, the accuracy of thickness variation is further improved by reducing the amount of deformation in the lower mold. be able to.
【0061】(他の実施形態)以上、説明した実施形態
においては、上型部材でガラス素材の変形を終了した時
点での、ガラス素材の外径が、いずれも、側面形成部材
に接触していない例となっているが、これは一つの目安
であり、仮に、ガラス素材が側面形成部材に接触してい
たとしても、密閉空間からガラス素材がはみ出すことな
く変形が終了していれば、本発明の趣旨(技術的範囲)
を逸脱するものではない。従って、形状や成形条件によ
っては、ガラス素材が側面形成部材に接触した状態で、
上型部材でのガラス素材の変形が終了する場合も考えら
れる。(Other Embodiments) In the embodiment described above, the outer diameter of the glass material at the time when the deformation of the glass material by the upper mold member is finished is in contact with the side surface forming member. Although this is not an example, this is only a guide, and even if the glass material is in contact with the side surface forming member, if the glass material has not deformed Purpose of the invention (technical scope)
Does not deviate. Therefore, depending on the shape and molding conditions, in a state where the glass material is in contact with the side surface forming member,
It is also conceivable that the deformation of the glass material in the upper mold member ends.
【0062】また、これら実施形態においては、レンズ
の外径側面を成形するために、いずれも、リング状の側
面形成部材を使用しているが、特に問題がなければ、側
面形成部材の代わりに、胴型の一部にレンズの外径側面
を転写する部分を形成して、成形を行ってもよい。In each of these embodiments, a ring-shaped side surface forming member is used for molding the outer diameter side surface of the lens. However, if there is no particular problem, the side surface forming member is used instead. Alternatively, molding may be performed by forming a portion for transferring the outer diameter side surface of the lens on a part of the body mold.
【0063】これら実施形態においては、いずれも、成
形型について、1個取りの例で説明しているが、もちろ
ん、所謂、多数個取りでも可能であり、また、レンズの
みでなく、プリズムなどの、様々な形状の光学素子に応
用できることは言うまでもない。In each of these embodiments, the molding die is described as a single-piece example. However, it is needless to say that a so-called multi-piece molding is also possible. Needless to say, the present invention can be applied to optical elements having various shapes.
【0064】[0064]
【発明の効果】以上説明したように、第1の発明によれ
ば、まず、上型でプレスを開始し、押し切った時点でガ
ラス素材の変形代を残した状態で密閉空間を形成し、そ
の後下型でプレスすることによりガラス素材の変形を完
了させるようにしたため、簡単なプロセスの変更によ
り、上型によるプレス時の密閉空間からのガラス素材の
はみ出しを防止することができ、まず型に余分な逃げ部
を設ける必要がなくなる。それにより型の余分な加工が
減り、また成形されたレンズの後加工が不要となる。ま
た高価な近似形状のガラス素材を使用する必要がなくな
り、あらゆる形状のガラス素材に適用することができ
る。As described above, according to the first aspect of the present invention, first, the press is started with the upper die, and at the time when the press is completely cut, the sealed space is formed with the deformation allowance of the glass material left. Since the deformation of the glass material is completed by pressing with the lower mold, it is possible to prevent the glass material from protruding from the closed space at the time of pressing by the upper mold by changing the simple process. It is not necessary to provide a relief part. This reduces extra processing of the mold and eliminates the need for post-processing of the molded lens. Further, it is not necessary to use an expensive glass material having an approximate shape, and the present invention can be applied to glass materials having various shapes.
【0065】さらにプレス時の下型動作が原因で起きる
ガラス素材の型に対するずれもなくなり、素材のずれに
より発生する成形品の偏肉(ずれ)不良や、ずれた方に
発生するガラスの過密充填によるバリや融着の発生など
を防止することができる。Further, the displacement of the glass material with respect to the mold caused by the operation of the lower mold at the time of pressing is also eliminated, and the uneven thickness (displacement) of the molded product caused by the displacement of the material and the overfilling of the glass generated in the displaced direction. And the occurrence of burrs and fusion due to the above can be prevented.
【0066】また下型のみでプレスする方法に比べ、一
度、上型で押し切って肉厚を決定した後に、残りの変形
のみを下型で行うため、高価な装置を使用することな
く、肉厚の安定した成形品が得られるなど、その効果は
大きい。Compared to the method of pressing only with the lower mold, the thickness is determined by pushing the upper mold once and then the remaining deformation is performed with the lower mold. Therefore, the thickness is reduced without using an expensive apparatus. The effect is great, for example, a stable molded article can be obtained.
【0067】また、第2の発明によれば、第1の発明に
おいて、下型でガラス素材を押圧開始する時の型の温度
を、上型でのプレス温度と同じか、あるいは低くても1
5℃より小さい温度差の範囲で行うようにしたため、下
型でのガラス素材の押圧変形をより容易な範囲で行うこ
とができるとともに、その変形量を容易に調整すること
ができる。Further, according to the second invention, in the first invention, the temperature of the mold at the time of starting pressing the glass material with the lower mold is equal to or lower than the pressing temperature of the upper mold.
Since the temperature difference is set within a range of less than 5 ° C., the pressing and deformation of the glass material with the lower mold can be performed in an easier range, and the amount of deformation can be easily adjusted.
【0068】また、第3の発明によれば、第1の発明に
おいて、プレス工程で温度を一定にしたまま、上型およ
び下型でのガラス素材の押圧変形を順次行い、下型での
押圧を一旦解除した後に冷却工程に移り、型温がプレス
工程より15℃以上低くなった時点で、再度、下型によ
る押圧を行うようにしたため、下型でのガラス素材の押
圧変形を必要以上に行うことなく、冷却中の、成形品の
面の崩れを防止することができ、肉厚精度と面精度とも
良好な成形品を得ることができる。According to the third invention, in the first invention, while the temperature is kept constant in the pressing step, the pressing and deformation of the glass material in the upper mold and the lower mold are sequentially performed, and the pressing in the lower mold is performed. After the mold is once released, the process moves to the cooling process, and when the mold temperature becomes lower than the press process by 15 ° C. or more, the pressing by the lower mold is performed again. Without performing the process, it is possible to prevent the surface of the molded product from collapsing during cooling, and to obtain a molded product having good wall thickness accuracy and surface accuracy.
【0069】また、第4の発明によれば、前記第1〜3
の発明において、上型の押圧による変形後のガラス素材
の外径が、側面形成部材の内径以下となるように上型押
圧時の下型高さの位置を調整するようにしたため、上型
が押し切って密閉空間を形成する前の、ガラス素材が側
面形成部材の内径より外側にはみ出すことによって起き
るバリの発生や、そのバリを挟み込むことで起きる、上
型の押し切り不良による成形品肉厚ばらつき不良を防止
することができる。According to the fourth aspect of the present invention, the first to third aspects are provided.
In the invention of the above, since the outer diameter of the glass material after being deformed by pressing the upper mold, the position of the lower mold height at the time of pressing the upper mold is adjusted so as to be equal to or less than the inner diameter of the side surface forming member. Burrs caused by the glass material protruding outside the inner diameter of the side surface forming member before forming the closed space by pushing it out, and uneven thickness of the molded product due to poor cutting of the upper mold caused by sandwiching the burr Can be prevented.
【図1】本発明の一実施形態である光学素子の成形方法
を示す型の縦断面図であり、ガラス素材を型に供給した
後の、プレス前の工程を示した図である。FIG. 1 is a longitudinal sectional view of a mold showing a molding method of an optical element according to an embodiment of the present invention, showing a process after pressing a glass material into the mold and before pressing.
【図2】本発明の一実施形態である光学素子の成形方法
を示す型の縦断面図であり、上型でのガラス素材を押し
切った状態で示した図である。FIG. 2 is a longitudinal sectional view of a mold showing a method for molding an optical element according to an embodiment of the present invention, and is a view showing a state in which a glass material in an upper mold is pushed out.
【図3】本発明の一実施形態である光学素子の成形方法
を示す型の縦断面図であり、下型での押圧変形動作が終
了した状態を示した図である。FIG. 3 is a longitudinal sectional view of a mold showing a method for molding an optical element according to an embodiment of the present invention, and is a view showing a state where a pressing deformation operation in a lower mold is completed.
【図4】本発明の一実施形態である光学素子の成形方法
を示すプロセス線図である。FIG. 4 is a process diagram showing a method for molding an optical element according to an embodiment of the present invention.
【図5】本発明の他の実施形態である光学素子の成形方
法を示す型の縦断面図であり、下型での押圧変形動作が
終了した状態を示した図である。FIG. 5 is a longitudinal sectional view of a mold showing a method of molding an optical element according to another embodiment of the present invention, and is a view showing a state where a pressing deformation operation with a lower mold has been completed.
【図6】本発明の他の実施形態である光学素子の成形方
法を示すプロセス線図である。FIG. 6 is a process diagram showing a method for molding an optical element according to another embodiment of the present invention.
【図7】従来の方法による光学素子の成形方法を示す型
の縦断面図であり、上型でのガラス素材を押し切った状
態を示した図である。FIG. 7 is a longitudinal sectional view of a mold showing a molding method of an optical element according to a conventional method, and is a view showing a state in which a glass material is pushed off by an upper mold.
1,21 上型部材 2,22 下型部材 1a,2a,21a,22a 成形面 1b,3b,21b,23b 当接部 1c,21c フランジ部 3,23 側面形成部材 4 胴型 4a 開口部 5 支持基板 5a 貫通穴 6,36 ガラス素材 7,8 ヒータ 11,12,14,31,32 スペーサ 16,26 成形品 36a はみ出し部 1,21 Upper mold member 2,22 Lower mold member 1a, 2a, 21a, 22a Molding surface 1b, 3b, 21b, 23b Contact part 1c, 21c Flange part 3,23 Side surface forming member 4 Trunk mold 4a Opening 5 Support Substrate 5a Through hole 6,36 Glass material 7,8 Heater 11,12,14,31,32 Spacer 16,26 Molded product 36a Protruding part
Claims (4)
型の各成形面および側面形成部材の表面で密閉空間を形
成するように、前記上型、下型および側面形成部材を含
む成形型セットを制御して、下型に置かれた変形可能な
加熱ガラス素材を押圧する光学素子の成形方法におい
て、プレス開始時にまず上型を下降させ、該上型により
前記密閉空間が形成される前にガラス素材の押圧を開始
するが、上型の下降が終了した時点ではガラス素材がま
だ変形途中であり、その後、下型を上昇させてガラス素
材を押圧し、前記密閉空間内での成形に必要な残りの変
形を完了させることを特徴とする光学素子の成形方法。When the upper mold has finished descending, the upper mold, the lower mold, and the side face forming member are formed so that a closed space is formed by the molding surfaces of the upper mold and the lower mold and the surfaces of the side face forming members. In the method of molding an optical element for controlling a mold set including a deformable heating glass material placed on a lower mold, the upper mold is first lowered at the start of pressing, and the closed space is formed by the upper mold. Although the pressing of the glass material is started before being performed, the glass material is still deforming at the time when the lowering of the upper mold is completed, and thereafter, the lower mold is raised to press the glass material, and in the closed space, A method for forming an optical element, wherein the remaining deformation required for forming the optical element is completed.
温をTu とした時、下型での押圧開始時の型温度T
L が、TU −15℃<TL ≦TU であることを特徴とす
る請求項1に記載の光学素子の成形方法。2. When the mold temperature at the start pressing the glass material was T u in the upper mold, the mold temperature at the start pressing under type T
L is, molding of an optical element according to claim 1, characterized in that a T U -15 ℃ <T L ≦ T U.
ま、上型および下型によるガラス素材の押圧を順次行
い、かつ、プレス工程における下型でのガラス素材の押
圧状態を一旦解除した後に、冷却工程に移り、その後、
型の温度が、プレス工程より15℃以上低くなった時点
で、再度、下型による押圧を行うことを特徴とする請求
項1に記載の光学素子の成形方法。3. Pressing the glass material by the upper die and the lower die sequentially while keeping the temperature of the die constant in the pressing step, and once releasing the pressing state of the glass material by the lower die in the pressing step. , Moving to the cooling process,
2. The method of molding an optical element according to claim 1, wherein the pressing by the lower mold is performed again when the temperature of the mold becomes lower than the pressing step by 15 [deg.] C. or more.
間での上型の押圧による変形後で、ガラス素材の外径
が、側面形成部材の内径以下に留まるように、上型押圧
時の下型高さの位置が調整されていることを特徴とする
請求項1〜3の何れか1項に記載の光学素子の成形方
法。4. The lower mold during the pressing of the upper mold so that the outer diameter of the glass material remains below the inner diameter of the side surface forming member after the upper mold in the closed space is deformed by the pressing of the upper mold. The method of molding an optical element according to claim 1, wherein a height position is adjusted.
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JP2001041924A JP3825978B2 (en) | 2001-02-19 | 2001-02-19 | Optical element molding method |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006224658A (en) * | 2005-01-19 | 2006-08-31 | Hoya Corp | Manufacturing method of mold press forming die and optical element |
JP2006315877A (en) * | 2005-05-10 | 2006-11-24 | Hoya Corp | Method for producing formed article, and method for producing preform |
CN100348522C (en) * | 2004-11-26 | 2007-11-14 | 亚洲光学股份有限公司 | Glass moulded shaper for positioning nitre materials and bearing glasses |
CN100398473C (en) * | 2004-05-26 | 2008-07-02 | 亚洲光学股份有限公司 | Model forming device and method for optical glass lens |
JP2013253001A (en) * | 2012-06-07 | 2013-12-19 | Canon Inc | Method for manufacturing optical element |
-
2001
- 2001-02-19 JP JP2001041924A patent/JP3825978B2/en not_active Expired - Fee Related
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100398473C (en) * | 2004-05-26 | 2008-07-02 | 亚洲光学股份有限公司 | Model forming device and method for optical glass lens |
CN100348522C (en) * | 2004-11-26 | 2007-11-14 | 亚洲光学股份有限公司 | Glass moulded shaper for positioning nitre materials and bearing glasses |
JP2006224658A (en) * | 2005-01-19 | 2006-08-31 | Hoya Corp | Manufacturing method of mold press forming die and optical element |
JP2006315877A (en) * | 2005-05-10 | 2006-11-24 | Hoya Corp | Method for producing formed article, and method for producing preform |
JP4677279B2 (en) * | 2005-05-10 | 2011-04-27 | Hoya株式会社 | Manufacturing method of molded body |
JP2013253001A (en) * | 2012-06-07 | 2013-12-19 | Canon Inc | Method for manufacturing optical element |
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