JP2009242186A - Glass forming unit, spherical glass gob production device, and spherical glass gob production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass forming unit and a spherical glass gob production device by which production cost and environmental load can be reduced and glass gobs can be improved in sphericity. <P>SOLUTION: The spherical glass gob production device 10 includes the glass forming unit and a molten glass feed unit 50. The glass forming unit includes forming dies 20 for forming spherical glass gobs from molten glass fed from the molten glass feed unit 50 and a vibration part 30 for vibrating the forming dies 20. Each forming die 20 has a recessed portion which has a partially spherical bottom and receives molten glass, wherein the recessed portion preferably has a maximum depth ≥1.5 times the curvature radius of the bottom. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for manufacturing spherical glass, and more particularly to a glass forming apparatus, a spherical glass lump manufacturing apparatus, and a spherical glass lump manufacturing method.

  Conventionally, a preform formed into an optical element or the like has been manufactured by grinding and polishing a cut piece of a glass block into a spherical shape. However, in such a method, grinding and polishing are very expensive, and a large amount of glass waste is generated, so that the burden on the environment is large.

Therefore, a technique for producing a glass lump by using a molding die having a substantially spherical recess and dropping and cooling molten glass into the recess that ejects gas has been developed (see, for example, Patent Document 1). According to this technique, a glass lump having a shape corresponding to the recess is naturally formed, so that the burden of grinding and polishing is reduced. For this reason, the manufacturing cost and the burden on the environment can be reduced.
JP-A-2-14839

  However, in the technique shown in Patent Document 1, in the dropped molten glass, the surface that contacts the recess has a shape along the recess, and the surface that does not contact the recess becomes flat due to the gravity of the molten glass. Moreover, according to the method described in Patent Document 1, depending on the size and shape of the molten glass to be dropped, the molten glass is difficult to rotate and it is difficult to make a spherical preform. For this reason, the molten glass to be produced has an asymmetric and distorted shape and has a low sphericity.

  The present invention has been made in view of the above circumstances, a glass forming apparatus, a spherical glass lump manufacturing apparatus, and a spherical glass lump that can reduce the manufacturing cost and the burden on the environment and improve the sphericity of the glass lump. An object is to provide a manufacturing method.

  The inventors of the present invention have found that the molten glass dropped on the mold is rotated and spheroidized by vibrating the mold, and the present invention has been completed. Specifically, the present invention provides the following.

  (1) A glass forming apparatus comprising a forming die for forming a spherical glass lump from molten glass, and vibration means for vibrating the forming die.

  (2) The mold has a concave portion that has a partially spherical bottom and receives molten glass, and the maximum depth of the concave is 1.5 times or more the curvature radius of the bottom (1). Glass forming equipment.

  (3) The glass forming apparatus according to (2), wherein the concave portion is formed of a porous material.

  (4) The glass forming apparatus according to (3), further comprising gas supply means for supplying gas to the recess and ejecting the gas from the porous portion.

(5) A plurality of the molds are provided,
The glass forming apparatus further comprises moving means for sequentially moving the mold from a molten glass receiving position to a spherical glass lump derivation position,
The glass forming apparatus according to any one of (1) to (4), wherein the vibration means vibrates the forming die downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position.

  (6) The glass forming device according to (5), wherein the vibration means is fixed at a position where vibration energy can be conducted to the forming mold moved downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position. apparatus.

  (7) A spherical glass lump manufacturing apparatus comprising: the glass forming apparatus according to any one of (1) to (6); and a molten glass supply apparatus that supplies molten glass to the mold.

  (8) An optical element manufacturing apparatus comprising: the spherical glass lump manufacturing apparatus according to (7); and a precision press molding apparatus that performs precision press molding of the spherical glass lump manufactured by the spherical glass lump manufacturing apparatus.

(9) A spherical glass lump manufacturing method for manufacturing a spherical glass lump from molten glass,
A method for producing a spherical glass lump comprising a vibration step of vibrating a mold for forming a spherical glass lump from molten glass.

(10) The mold includes a concave portion having a partially spherical bottom portion that receives molten glass, and the maximum depth of the concave portion is 1.5 times or more the curvature radius of the bottom portion,
The said method is a spherical glass lump manufacturing method as described in (9) which has a supply process which supplies a molten glass to the said recessed part.

  (11) The spherical glass lump manufacturing method according to (10), wherein the concave portion is formed of a porous material.

  (12) The spherical glass lump manufacturing method according to (11), further comprising a gas ejection step of supplying gas to the recess and ejecting the gas from the porous portion.

(13) A plurality of the molds are provided, and further includes a moving step of sequentially moving from the molten glass receiving position to the spherical glass lump derivation position,
The spherical glass lump manufacturing method according to any one of (9) to (12), wherein the vibration step is performed downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position.

  (14) The spherical glass according to (13), wherein the vibration source of vibration is fixed at a position where vibration energy can be conducted to the mold moved downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position. Mass production method.

  (15) A method for producing an optical element, comprising subjecting a spherical glass mass produced by the spherical glass mass production method according to any one of (9) to (14) to precision press molding.

(16) A mold for molding a spherical glass lump from molten glass,
A mold having a concave part having a partially spherical bottom and receiving molten glass, wherein the maximum depth of the concave part is at least 1.5 times the radius of curvature of the bottom.

  (17) The mold according to (16), wherein the concave portion is formed of a porous material.

  (18) The mold according to (17), further comprising gas supply means for supplying gas to the recess and ejecting the gas from the porous portion.

  According to the present invention, since the mold vibrates, the molten glass lump received in the mold is randomly rotated and spheroidized. Therefore, the sphericity of the glass lump can be improved, and the burden of grinding and polishing for spheroidization is reduced, so that the manufacturing cost and the burden on the environment can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the modified example other than the embodiment, the same reference numerals are given to those common to the embodiment, and the description thereof is omitted. In addition, in this specification, when there are a plurality of constituent elements, subscripts such as “a” to “g” may be added (for example, the mold 20a) or may be described without adding subscripts as a generic name ( For example, there may be a mold 20).

  FIG. 1 is a schematic configuration diagram of a spherical glass lump manufacturing apparatus 10 according to an embodiment of the present invention. FIG. 2 is a side view of the spherical glass lump manufacturing apparatus 10 of FIG. 1 viewed from the P direction. FIG. 3 is a cross-sectional view of the mold 20 of FIG. 1 in a cross section passing through the central axis of the recess 22.

  The spherical glass lump manufacturing apparatus 10 according to the present embodiment includes a molding die 20, a vibrating unit 30 as a vibrating unit, a moving unit 40 as a moving unit, and a molten glass supply device 50. Among these, the shaping | molding die 20 and the vibration part 30 comprise a glass forming apparatus, and the glass forming apparatus which concerns on this embodiment is further provided with the moving part 40. FIG. Each component will be described in detail below.

[Molding mold]
The mold 20 forms a spherical glass lump from molten glass. As shown in FIG. 3, the mold 20 includes a recess 22 that receives the molten glass from the molten glass supply device 50. The concave portion 22 has a partially spherical bottom portion 221, which is connected to the side portion 223 and eventually reaches the surface of the mold 20. The boundary between the bottom part 221 and the side part 223 is preferably smooth in that the molten glass lump can be smoothly rotated in the concave part 22 described later. That is, in the present embodiment, there are some corners at the boundary, but it is preferable that the boundary is formed of a curved surface.

  If there is a portion of the molten glass block MG received in the recess 22 that protrudes from the recess 22 to the outside (upward in FIG. 3), the portion is cooled much more rapidly than the other portions. Then, since the density of the molten glass lump MG becomes uneven, smooth rotation can be inhibited. Therefore, it is desirable that the recess 22 is sufficiently deep so that the molten glass lump MG does not protrude outside.

  Here, the diameter of the molten glass lump MG received in the recess 22 basically depends on the tip diameter of the molten glass supply device 50, but the upper limit of the diameter of the molten glass lump MG is limited by the size of the recess 22. . That is, when the bottom 221 is a partial spherical surface having a central angle 2Θ and the radius of curvature is r, the width of the recess 22 is 2rsinΘ (see Fig. 3 (a)), so the upper limit of the diameter of the molten glass block MG is also 2rsinΘ. (See FIG. 3B). For this reason, the maximum depth D of the concave portion 22 only needs to be 2 rsinΘ or more, and is usually preferably 1.5 times or more, more preferably 1.6 times or more, and most preferably 2.0 times the radius of curvature r. It is more than double. Here, the maximum depth of the concave portion 22 refers to the distance between the deepest portion of the bottom portion 221 in the axial direction of the concave portion 22 and the opening formed by the concave portion 22.

  The material of the recess 22 is not particularly limited, and may be porous, carbon, a known metal, or the like. However, the recess 22 in the present embodiment is formed to be porous so as to suppress the high-temperature molten glass lump MG from adhering to the recess 22. In the present embodiment, the inner surface U-shaped porous body 213 is fitted in the recess of the metal base 211 of the mold body, but the entire mold may be a porous body.

  The porous body 213 is communicated with the introduction port 231 through the communication path 233. A gas supply source 23 is connected to the introduction port 231, and compressed gas is introduced from the gas supply source 23 into the introduction port 231. Then, since the compressed gas flows into the porous body 213 through the communication path 233 and is ejected inward of the concave portion 22, adhesion of the molten glass lump MG to the concave portion 22 is further suppressed. The gas supply source 23, the inlet 231 and the communication path 233 described above constitute a gas supply means.

  In the present embodiment, the communication path 233 communicates with the deepest portion of the porous body 213, but is not limited thereto, and may communicate with an arbitrary portion of the porous body 213. Moreover, the part connected to the porous body 213 is not limited to one place, and may be a plurality of places. Thereby, since gas is ejected from many directions, adhesion to the recessed part 22 of molten glass MG can be suppressed more.

  In the present embodiment, an extension part 25 extending in the axial direction of the recess 22 is provided in 21, and the extension part 25 penetrates an installation table 41 described later. The extending portion 25 can contact a vibration portion 30 described below located below the installation table 41, and conducts vibration energy from the vibration portion 30 to 21 when contacting the vibration portion 30.

  In the present embodiment, the extending portion 25 is loosely fitted to and penetrates the installation base 41. For this reason, 21 and the extension part 25 can slide up and down with respect to the installation base 41. Here, although not shown, a ridge is provided on the side surface of the extending portion 25. When the extension portion 25 slides upward, the heel is eventually locked to the installation base 41, so that the extension portion 25 can be prevented from being detached from the installation base 41.

[Moving part]
The moving unit 40 moves the molding die 20 from a molten glass receiving position where the recessed portion 22 receives the molten glass GD from the molten glass supply device 50 to a spherical glass lump derivation position where the glass lump in the recessed portion 22 is derived. Since the mold 20 moves in this way, even if a plurality of molds 20 are provided as described later, there is little need to install a large number of molten glass supply devices 50 and spherical glass lump deriving means. In addition, what is necessary is just to perform the derivation | leading-out of a glass lump in accordance with a conventional method, for example by suction of a glass lump.

  As shown in FIG. 1, the moving unit 40 according to the present embodiment includes a disk-shaped installation table 41, and a rotation shaft 43 is provided at the center of the installation table 41. The rotating shaft 43 is connected to a driving source (not shown) (for example, a motor) and is rotated by the driving force of the driving source. On the other hand, the molding die 20 is installed in the non-center of the installation table 41, and when the rotary shaft 43 rotates, the molding die 20 moves on a circumferential track.

  In the present embodiment, a plurality of molding dies 20 are installed on the installation table 41, and are particularly arranged concentrically and at approximately equal intervals. Thereby, when the rotating shaft 43 rotates, each of the molds 20 sequentially moves and passes through the molten glass receiving position and the spherical glass lump derivation position. For convenience of explanation, reference numerals 20a to 20f are given to molds located downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position at a certain point in time.

  Although the movement form of the mold 20 in this embodiment is not particularly limited, it can be moved at a low speed or in a normal speed state so that the molten glass droplet GD can be reliably received by the recess 22 at the molten glass receiving position. It is preferable to put a stop or slow-down state for a predetermined time between them. Further, the moving unit 40 is not a disk-shaped installation table, but may be a conveyor that can move the mold in an arbitrary direction.

(Vibration part)
The vibration unit 30 vibrates the mold 20. The vibration unit 30 has a vibration source (not shown), and the vibration table 31 is vibrated by the vibration source. The vibration table 31 has an upper surface 313, and the upper surface 313 is disposed below the installation position of the mold 20. One end of the upper surface 313 is connected to the inlet inclined surface 311 and inclined downward, and the other end is connected to the outlet inclined portion 315 and inclined downward.

  The vibration unit 30 vibrates the mold 20 downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position. In this embodiment, it is fixed to a position where vibration energy can be conducted to the moved molds 20b to 20e. Specifically, the inlet inclined surface 311 is positioned immediately after the molten glass receiving position, and the outlet inclined portion 315 is positioned immediately before the spherical glass receiving position. Then, the extended portion 25 of the mold 20 that has passed the molten glass receiving position rides on the inlet inclined surface 311, slides on the upper surface 313, then slides on the outlet inclined portion 315, and reaches the spherical glass receiving position. As a result, only the molds 20b to 20e moved downstream of the molten glass receiving position and upstream of the spherical glass lump deriving position vibrate. The mold may be vibrated only in a part downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position, and conversely, other than downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position. It may span.

  Although the vibration of the vibration part 30 is not specifically limited, It is preferable to move up and down in the direction of gravity in that the rotation of the molten glass lump MG in the recess 22 can be further promoted. Note that the vertical movement in the direction of gravity does not mean that the vibration vector has a component in the vertical direction with respect to the direction of gravity and should not have a component in the other direction.

  It is preferable that the intersecting portion of the entrance inclined surface 311 and the upper surface 313 and the intersecting portion of the upper surface 313 and the exit inclined portion 315 are smooth in that the movement of the mold 20 can be smoothed. In other words, in the present embodiment, there are some corners at the intersection, but it is preferable that the intersection be a curved surface.

[how to use]
Next, the spherical glass lump manufacturing method using the above spherical glass lump manufacturing apparatus 10 will be described.

  First, the drive source is driven, and the movement of the plurality of molds 20 is started through the rotation of the installation table 41. Hereinafter, the molding die 20a will be described as an example. When the molding die 20a moves to the molten glass receiving position, a molten glass droplet GD falls from the tip of the molten glass supply device 50 and is received in the recess 22 (supplying step). In particular, in this embodiment, the recess 22 is formed of a porous material. And since the gas supplied from the gas supply source 23 is ejected from the part of the porous body 213 (gas ejection process), the gas acts on the molten glass lump MG and gradually cools the molten glass lump MG. go.

  Subsequently, the mold 20a that has received the molten glass lump MG is sequentially moved to the spherical glass lump derivation position (moving step). As described above, the vibration part 30 is fixed at a position where vibration energy can be conducted to the mold that has moved downstream of the molten glass receiving position and upstream of the spherical glass lump extraction position. The portion 25a rides on the entrance inclined surface 311 and then slides on the upper surface 313. During this time, vibration energy from the vibration table 31 is conducted to the mold 20a through the extending portion 25a, and the mold 20a is vibrated (vibration process). Then, as shown in FIG. 4, since the direction and force of the jet gas acting on the molten glass lump MG on the concave portion 22 fluctuate, the molten glass lump MG rotates at random and is gradually formed into a substantially spherical shape. Go.

  The rotation of the molten glass block MG is preferably performed in a state where the molten glass block MG is floated from the recess 22 by the jetted gas. For this purpose, it is preferable to adjust the gas ejection amount in consideration of the mass of the molten glass block MG, the shape of the recess 22 and the like. In addition, although it is preferable that a floating state is maintained in the whole time between the movement to a spherical glass lump derivation | leading-out position, a non-floating state may exist in part.

  When the extension part 25a of the mold 20a finishes sliding on the outlet inclined part 315, the mold 20a and the vibration part 30 are no longer in contact with each other, so that the vibration of the mold 20a is settled and the vibration process ends. Thereafter, the mold 20a reaches the spherical glass lump derivation position (position of the mold 20f in FIG. 2), and the spherical glass lump molded in the recess 22 is derived. Thus, the vibration process is performed downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position.

  Since the glass lump thus produced has a high sphericity, an excellent optical element can be produced by precision press molding using a known precision press molding apparatus.

[Function and effect]
According to this embodiment, the following effects can be obtained.

  Since the mold 20 vibrates, the molten glass lump MG received in the recess 22 of the mold 20 rotates at random and spheroidizes. Therefore, the sphericity of the glass lump can be improved, and the burden of grinding and polishing for spheroidization is reduced, so that the manufacturing cost and the burden on the environment can be reduced.

  Since the maximum depth D of the recess 22 is 1.5 times or more the radius of curvature r of the bottom 221 of the recess 22, the molten glass lump MG is surrounded by the recess 22, and uneven density is suppressed. Thereby, since smooth rotation is accelerated | stimulated, the sphericity of a glass lump can be improved more.

  Since the concave portion 22 is formed of a porous material and gas can be ejected, adhesion of the molten glass to the concave portion 22 is suppressed, and the purity of the glass lump can be increased.

  Since the gas is ejected to the molten glass lump MG, adhesion of the molten glass to the concave portion 22 is further suppressed, and the purity of the glass lump can be further increased. In addition, since the balance of the force exerted by the ejected gas on the molten glass lump MG is lost due to the vibration of the mold 20 by the vibration unit 30, random rotation of the molten glass lump MG is further promoted. Thereby, the sphericity of a glass lump can be improved more.

  Since a plurality of molds 20 are provided, a large amount of glass lump can be produced. As the number of molding dies 20 increases, the required vibration energy increases, and there is a concern about an increase in manufacturing cost. However, according to this embodiment, only downstream of the molten glass receiving position and upstream of the spherical glass lump deriving position. Since the mold 20 is configured to vibrate, vibration energy is suppressed to the minimum necessary, and the manufacturing cost can be reduced.

  Vibration energy is naturally conducted to the mold 20 moved downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position, and the molten glass lump MG is spheroidized. For this reason, it is not necessary to separately provide a mechanism for moving the vibration unit 30 and a control unit for the mechanism, and the configuration of the apparatus 10 can be simplified.

[Modification]
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention. For example, the following modifications are mentioned.

  FIG. 5 is a cross-sectional view of a spherical glass lump manufacturing apparatus 10A according to a modification of the present invention. This modification is different from the above embodiment in the configuration of the vibration unit 30A.

  That is, the vibration unit 30A includes a plurality of vibration tables 31Aa to 31Ad, and these vibration tables 31Aa to 31Ad include a distance adjusting unit (not shown) that adjusts the distance from the extending portion 25. As a result, the vibration table 31 </ b> A approaches and contacts the extension portion 25 that has passed upstream of the spherical glass lump derivation position, and the vibration energy is conducted to the recess 22 via the extension portion 25. After this state is maintained for a while, when the extension part 25 reaches the position 25e, the vibration table 31A is separated from the extension part 25, and the vibration process ends. The separated vibration table 31A returns again to the position of 31Aa and repeats approaching to the extending portion 25.

It is a whole perspective view of the spherical glass lump manufacturing apparatus concerning one embodiment of the present invention. It is the side view which looked at the spherical glass lump manufacturing apparatus of FIG. 1 from the P direction. It is sectional drawing of the shaping | molding die of FIG. 1 in the cross section which passes along the central axis of a recessed part. It is a notch perspective view of the shaping | molding die which comprises the spherical glass lump manufacturing apparatus of FIG. It is a schematic block diagram of the spherical glass lump manufacturing apparatus which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10A spherical glass lump manufacturing apparatus 20 Mold 213 Porous body 22 Recessed part 221 Bottom part 30, 30A Vibration part (vibration means)
40 Moving part (moving means)
50 Molten glass supply device MG Molten glass lump

Claims (18)

  A glass forming apparatus comprising a forming die for forming a spherical glass lump from molten glass, and vibration means for vibrating the forming die.   2. The glass molding according to claim 1, wherein the mold has a concave portion that has a partially spherical bottom and receives molten glass, and the maximum depth of the concave is 1.5 times or more the radius of curvature of the bottom. apparatus.   The glass forming apparatus according to claim 2, wherein the recess is formed of a porous material.   The glass forming apparatus according to claim 3, further comprising gas supply means for supplying a gas to the recess and ejecting the gas from the porous portion. A plurality of the molds are provided,
The glass forming apparatus further comprises moving means for sequentially moving the mold from a molten glass receiving position to a spherical glass lump derivation position,
5. The glass forming apparatus according to claim 1, wherein the vibration unit vibrates the forming die downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position.   6. The glass forming apparatus according to claim 5, wherein the vibration means is fixed at a position where vibration energy can be conducted to the forming mold moved downstream of the molten glass receiving position and upstream of the spherical glass lump extracting position.   A spherical glass lump manufacturing apparatus comprising: the glass forming apparatus according to claim 1; and a molten glass supply apparatus that supplies molten glass to the mold.   An apparatus for manufacturing an optical element, comprising: the spherical glass lump manufacturing apparatus according to claim 7; and a precision press molding apparatus for precisely press-molding the spherical glass lump manufactured by the spherical glass lump manufacturing apparatus. A spherical glass lump production method for producing a spherical glass lump from molten glass,
A method for producing a spherical glass lump comprising a vibration step of vibrating a mold for forming a spherical glass lump from molten glass. The mold has a concave portion that has a partially spherical bottom and receives molten glass, and the maximum depth of the concave is 1.5 times or more the radius of curvature of the bottom,
The spherical glass lump manufacturing method according to claim 9, wherein the method includes a supplying step of supplying molten glass to the concave portion.   The spherical glass lump manufacturing method according to claim 10, wherein the recess is formed of a porous material.   The spherical glass lump manufacturing method according to claim 11, further comprising a gas ejection step of supplying a gas to the recess and ejecting the gas from the porous portion. A plurality of the molds are provided, and further includes a moving step of sequentially moving from the molten glass receiving position to the spherical glass lump leading position,
The spherical glass lump manufacturing method according to claim 9, wherein the vibration step is performed downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position.   The spherical glass lump manufacturing method according to claim 13, wherein the vibration source of vibration is fixed at a position where vibration energy can be conducted to the mold moved downstream of the molten glass receiving position and upstream of the spherical glass lump derivation position. .   The manufacturing method of the optical element which carries out precision press molding of the spherical glass lump manufactured by the spherical glass lump manufacturing method in any one of Claims 9-14. A mold for molding a spherical glass lump from molten glass,
A mold having a concave part having a partially spherical bottom and receiving molten glass, wherein the maximum depth of the concave part is at least 1.5 times the radius of curvature of the bottom.   The mold according to claim 16, wherein the recess is formed of a porous material.   The mold according to claim 17, further comprising gas supply means for supplying gas to the recess and ejecting the gas from the porous portion.

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