JP2004244243A - Optical device molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device molding machine in which the use quantity of an inert gas is reduced, the oxidation phenomenon of a molding die is remarkably decreased and as a result, a high quality optical device is produced. <P>SOLUTION: In the optical device molding machine provided at least with a molding section provided at least with an inert gas supply means for supplying an inert gas hardly causing at least chemical reaction with the molding die or a glass material at a high temperature and a molding means for applying pressure to the glass material through the molding die while heating the molding die and the glass material and a supply section for supplying the molding die and the glass material to the molding machine, the supply section and the molding section are set so that the pressure of the molding section is relatively made larger. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical element molding machine for manufacturing an optical element used for an optical device or the like by heating and molding a glass base material.
[0002]
[Prior art]
2. Description of the Related Art Instead of manufacturing optical elements such as lenses by polishing or the like, a technique of manufacturing a glass base material heated and softened by an optical element forming machine by glass forming with a forming die has been put to practical use.
[0003]
In a conventional optical element molding machine, an optical element is molded in the following steps. (1) First, a mold and a glass base material are set in an optical element molding machine. (2) The mold and the glass preform are heated, and when the glass preform is softened, the glass preform is pressed onto the mold to transfer the shape of the mold surface of the mold to the glass preform. {Circle around (3)} After the molding, the mold and the glass base material are cooled, the molded optical element is removed from the mold, taken out of the optical element molding machine, and the molding step is completed.
[0004]
In glass molding, metal is generally used as the material of the mold, so when oxygen gas in the atmosphere touches the mold at high temperature, the surface of the mold and the inner wall surface of the sleeve are oxidized. . Hereinafter, a set including a mold, a sleeve, and the like will be referred to as a mold member. In order to prevent this oxidation, in a conventional optical element molding machine, glass molding is performed in a closed container, and a molding die member and a glass base material are set in the closed container in the above (1), The air in the sealed container is replaced with an inert gas so that the atmosphere gas does not contain oxygen gas, and then the process proceeds to the step (2).
[0005]
[Problems to be solved by the invention]
However, the conventional optical element molding machine cannot take out the mold and the optical element from the closed container unless the closed container of the optical element molding machine is once directly opened to the atmosphere in the above (3). Upon release to the atmosphere, the inert gas contained in the sealed container is dissipated and lost. After setting the next glass preform and the molding die member in the closed container again, the inert gas must be supplied again to replace the air in the closed container with the inert gas. That is, every time a new glass preform is formed, a large amount of expensive inert gas is consumed, which increases the forming cost. If the replacement with the inert gas is insufficient, and the replacement of the oxygen inside the molding member with the inert gas is not completely performed, the oxygen remaining inside the molding die oxidizes the molding member. Sometimes happened. When the mold member is oxidized, clouding or the like occurs in the molded optical element, and the quality of the optical element is deteriorated.
[0006]
Therefore, one of the problems has been to increase the degree to which the oxygen has been sufficiently replaced with the inert gas including the inside and details of the mold member in the closed container, that is, to increase the replacement quality.
[0007]
An object of the present invention is to provide an optical element molding apparatus which solves the above-mentioned problems and in which an oxidation phenomenon of a mold member is extremely small, and as a result, a high quality optical element can be produced.
[0008]
[Means for solving the problem]
In order to solve the above problems, the optical element molding machine according to the first aspect of the present invention is an inert gas supply unit that supplies an inert gas that hardly causes at least a chemical reaction with a mold and a glass material at a high temperature, A molding chamber having a molding means for supplying a pressing force to the glass material via the molding die while heating the molding die and the glass material, and a supply chamber for supplying the molding die and the glass material to a molding machine. The supply chamber and the molding chamber are set so that the pressure in the molding chamber is relatively increased.
[0009]
The optical element molding machine according to a second aspect of the present invention is the optical element molding machine according to the first aspect, wherein at least the molding die or the glass material is supplied between the supply chamber and the molding chamber. An optical element molding machine having an isolating means that can be isolated except during transfer from a chamber to the molding chamber.
[0010]
The optical element molding machine according to a third aspect of the present invention is the optical element molding machine according to the first aspect, further comprising an extraction chamber for taking out the glass material molded in the molding chamber and the molding die from the optical element molding machine. Is provided separately from the supply chamber, and the unloading chamber is set at a lower pressure than the molding chamber.
[0011]
The optical element molding machine according to a fourth aspect of the present invention is the optical element molding machine according to the third aspect, wherein at least the transfer of the molding die or the glass material is performed between the molding chamber and the unloading chamber. Is an optical element molding machine provided with an isolating means for enabling isolation between the molding chamber and the unloading chamber.
[0012]
An optical element molding machine according to a fifth aspect of the present invention is the optical element molding machine according to the first aspect, wherein the molding die transferred from at least the molding chamber is between the molding chamber and the unloading chamber. And an optical element molding machine having cooling means for cooling the glass material.
[0013]
An optical element molding machine according to a sixth aspect of the present invention is the optical element molding machine according to the first aspect, wherein a transport means for transporting the molding die or the glass material is provided between the supply chamber and the molding chamber. An optical element molding machine comprising a transfer chamber provided.
[0014]
An optical element molding machine according to a seventh aspect of the present invention is the optical element molding machine according to the sixth aspect, wherein the transfer chamber optically forms the molding chamber, the glass material molded in the molding chamber, and the molding die. An optical element molding machine, wherein the optical element molding machine is also located between an unloading chamber to be taken out of the element molding machine and a cooling means for cooling the molding die and the glass material in the transfer chamber.
[0015]
An optical element molding machine according to an eighth aspect of the present invention is the optical element molding machine according to the first aspect, wherein the supply chamber further includes a decompression means capable of decompression after the molding die or the glass material is introduced. An optical element molding machine characterized by being provided.
[0016]
The optical element molding machine according to a ninth aspect of the present invention is the optical element molding machine according to the third aspect, wherein the extraction chamber includes an exhaust unit that exhausts an inert gas supplied from the molding chamber. An optical element molding machine characterized in that:
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
[First embodiment]
FIG. 1 shows an optical element molding machine of the present embodiment, and shows an internal cross-sectional view thereof. FIG. 2 is a plan view showing the transport mechanism 8, FIG. 3 shows a mold assembly 23, and FIG. 4 shows a heating mechanism. An optical element molding machine according to an embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 3, and FIG.
[0018]
In FIG. 1, an optical element molding machine according to an embodiment of the present invention includes a supply chamber 1, an intermediate chamber 2, a molding chamber 3, an extraction chamber 4, transport mechanisms 5, 7, 8, and a molding and transport mechanism 6. I can. In addition, I, II, III, IV, V, V ′, and VI indicate the position of the mold assembly 23.
[0019]
In the supply chamber 1 of the optical element molding machine according to the present embodiment, the position I, the vacuum pump 9 such as a rotary pump, the inert gas introduction unit 10, the pressure gauge 19, the partition valve 47, and the molding assembly 23 are set from outside. And a front door (not shown). The position I is a position where the mold assembly 23 is set from the outside. The valve body is rotated counterclockwise around the opening / closing shaft 53, the partition valve 47 is closed, the mold assembly 23 is set at the position I, the front door is closed, and the supply chamber 1 is closed. By operating the pump 9, the inside of the supply chamber 1 can be brought into a vacuum atmosphere. When the supply chamber 1 reaches a vacuum, the evacuation is stopped, and an inert gas is introduced from the gas introduction unit 10 to make the inside of the supply chamber 1 an inert gas atmosphere and oxygen is eliminated from the mold assembly 23. be able to. Since the pressure of the inert gas in the supply chamber 1 can be measured by the pressure gauge 19, the inside of the supply chamber 1 is adjusted to an inert gas atmosphere of a desired pressure by adjusting the inert gas introduction unit 10. can do. Further, the atmosphere in the supply chamber 1 is replaced with the atmosphere by opening the front door, but since the volume of the supply chamber 1 is small when viewed from the whole molding machine, the consumption of the inert gas can be reduced. . When the transport shaft 38 is raised to transport the mold assembly 23 from the position I to the position II, the valve body is rotated clockwise around the opening / closing shaft 53 to open the partition valve 47.
[0020]
The intermediate chamber 2 of the optical element molding machine according to the present embodiment includes a position II, a position III, a position V ′, a position V, cooling mechanisms 17 and 18, an inert gas introduction unit 11, An inert gas discharge unit 15 and a pressure gauge 20 for measuring the pressure in the intermediate chamber 2 are provided.
[0021]
The position II is a position where the conveying mechanism 8 receives the mold assembly 23 conveyed from the position I in the supply chamber 1 by the elevation of the conveying shaft 38. The position III is a position where the mold assembly 23 transported by the transport mechanism 8 is transferred to the molding and transport mechanism 6. The position V 'is a position where the formed mold assembly 23 is cooled. The position V is a position where the cooling die is completed and the mold assembly 23 transported by the transport mechanism 8 is transferred to the transport mechanism 7.
[0022]
The pressure of the intermediate chamber 2 is adjusted to a desired pressure by adjusting the amount of gas introduced from the inert gas introduction unit 11 and the amount of gas discharged from the inert gas discharge unit 15 while measuring the pressure with the pressure gauge 20. can do. The cooling mechanisms 17 and 18 are composed of water-cooled metal blocks, and the transport mechanism 8 places the mold assembly 23 on the cooling mechanism 17, and then raises the cooling mechanism 17 as indicated by an arrow 57, and performs cooling. The mechanisms 17 and 18 are pressed against the upper and lower surfaces of the mold assembly 23 to perform cooling by heat conduction.
[0023]
The molding chamber 3 of the optical element molding machine according to the present embodiment includes the position of the IV, the inert gas introduction section 12, the shaft seal 16, the gas flow path 50, the pressure gauge 21, the heater 24, and the thermocouple 25. The position IV is a position for performing inert gas replacement, heating and molding of the mold assembly 23. By adjusting the inert gas introduction part 12 while measuring the pressure with the pressure gauge 21, the inert gas in the molding chamber 3 can be adjusted to a desired pressure. The gas flow path 50 is a plurality of small holes formed around the shaft seal 16 so as to communicate the molding chamber 3 and the intermediate chamber 2, so that the pressure in the molding chamber 3 does not become excessive, and The number and size of the holes are determined so that the conductance can maintain an appropriate pressure difference. The heater 24 heats the mold assembly 23 at the heating molding position IV while measuring the temperature with the thermocouple 25 to make the glass base material have a viscosity suitable for molding.
[0024]
The take-out chamber 4 of the optical element molding machine of the present embodiment is provided with the position VI, the inert gas introduction part 13, the inert gas discharge part 14, the pressure gauge 22, the partition valve 48, and the mold assembly 23 of the optical element molding machine. It has a front door (not shown) for taking it out. The position VI is a position where the mold assembly 23 transported from the intermediate chamber 2 by the lowering of the transport shaft 40 is held for removal to the outside. In the extraction chamber 4, the valve body is rotated clockwise around the opening / closing axis 54, the partition valve 48 is closed, and the pressure is measured by the pressure gauge 22 while the front door is closed. By adjusting the exhaust pump connected to the inert gas discharge section 14, the inside of the extraction chamber 4 can be set to an inert gas atmosphere of a desired pressure. In addition, by controlling the exhaust pump connected to the inert gas discharge unit 14, the inert gas introduced from the inert gas introduction unit 12 always flows toward the extraction chamber 4. This makes it difficult for oxygen to reach the molding chamber 3 even if the extraction chamber 4 is opened to the atmosphere. It is preferable that the volume of the extraction chamber 4 is made as small as possible to reduce the consumption of the inert gas. When the conveying shaft 40 is lowered to lower the mold assembly 23 from the position V to the position VI, the valve body is rotated counterclockwise around the opening / closing shaft 54 to open the partition valve 48. Is configured.
[0025]
Next, the mold assembly 23 is configured as shown in FIG. Hereinafter, the mold assembly 23 will be described with reference to FIG. The mold assembly 23 includes an upper mold 26, a lower mold 27, a sleeve 28, a glass preform 29, and a carrier 30. The lower mold 27, the glass preform 29, and the upper mold 26 are fitted into the sleeve 28 in this order, and are fitted so that they can move up and down along the inner wall of the sleeve 28. The sleeve 28, the upper mold 26, the glass preform 29, and the lower mold 27 are placed on a carrier 30, and a carrier recess 31 is provided on a side surface of the carrier 30. The transfer recess 31 is used by the transfer mechanism 8 to transfer the mold assembly 23 in the intermediate chamber 2. Further, a thermocouple 25 insertion hole 32 is formed in the upper mold 26, and the temperature of the upper mold 26 can be measured by inserting the thermocouple 25 therein. The lower mold 27 is also provided with an insertion hole similar to that of the upper mold 26 and a through hole communicating with the insertion hole of the carrier 30 and a thermocouple is inserted therein. May be measured.
[0026]
Next, the transport mechanisms 5, 6, 7, and 8 of the optical element molding machine of the present embodiment will be described.
[0027]
FIG. 2 shows a top view of the transport mechanism 8 of the optical element molding machine of the present embodiment. The transport mechanism 8 of the optical element molding machine according to the present embodiment will be described with reference to FIGS.
[0028]
The transport mechanism 8 of the optical element molding machine according to the present embodiment transports the mold assembly 23 from the position II to the position III, from the position III to the position V ′, and from the position V ′ to the position V. It is configured to be able to. In the position II, the mold assembly 23 conveyed by the conveyance mechanism 5 from the position I can be received. At the position III, the mold assembly 23 can be delivered to the molding and conveying mechanism 6 and the molded mold assembly 23 can be received from the molding and conveying mechanism 6. At the position V ′, the formed mold assembly 23 can be delivered to the cooling mechanism 17 and the cooled mold assembly 23 can be received from the cooling mechanism 17. At the position V, the mold assembly 23 can be delivered to the transport mechanism 7.
[0029]
The transport mechanism 8 of the optical element molding machine of the present embodiment has a main part of the main body provided in the intermediate chamber 2, a ball screw 41, a moving mechanism 43 screwed to the ball screw 41, and a motor 42 for rotating the ball screw 41. And Further, the moving mechanism 43 has a grip portion 44 at a tip end thereof, and the grip portion 44 can be opened and closed in a direction indicated by 45 by an opening / closing mechanism (not shown). The grip 44 has a structure that can be moved by the grip 44 alone in the direction indicated by the arrow 46. FIG. 2 shows the gripping position moved in the direction A. The gripper 44 moves in the direction of A, performs an operation of gripping the mold assembly 23, is conveyed between the positions II to V, moves in the direction of B, and the gripper 44 retracts. However, the moving mechanism 43 can be moved between the positions II to V without interference.
[0030]
A method in which the transport mechanism 8 receives the mold assembly 23 will be described with reference to the following specific examples.
[0031]
At the position II, the transfer mechanism 8 operates as follows, and receives the mold assembly 23 transferred from the supply chamber 1. The moving mechanism 43 opens the grip portion 44, and moves to the position II in a state where the gripping portion 44 is retracted and retracted in the direction B. The mold assembly 23 stands by at the position II as the transport shaft 38 rises. In this state, the gripper 44 is advanced in the direction of A, the gripper 44 is closed, and the conveying dent 31 of the mold assembly 23 is sandwiched to grip the mold assembly 23. Thereafter, the transport shaft 38 can be lowered. FIG. 3 shows this gripping state. The conveyance is performed by rotating the motor 42 while holding the forming die assembly 23 to move the forming die assembly 23 to the left.
[0032]
A method in which the transfer mechanism 8 transfers the mold assembly 23 will be described with reference to the following specific examples.
[0033]
At the position III, the transport mechanism 8 operates as follows, and transfers the mold assembly 23 transported from the supply chamber 1. The moving mechanism 43 closes the grip portion 44 and moves to the position III while gripping the mold assembly 23. At the position III, the conveyed mold assembly 23 is located directly above the top 49 of the forming and conveying mechanism 6. In this state, the gripping portion 44 of the moving mechanism 43 is opened to release the gripping of the molding die assembly 23, and the molding die assembly 23 is placed on the top 49. In this way, the delivery is completed, and then the moving mechanism 43 moves the gripper 44 in the retreating direction B and moves to the next transport position. When the motor 42 is rotated forward, the moving mechanism 43 can be moved leftward, and when rotated reversely, the moving mechanism 43 can be moved rightward.
[0034]
The method of delivering and receiving the mold assembly 23 at other positions V, V ', and the like is substantially the same as the above-described method, and thus the description is omitted.
[0035]
The transport mechanism 5 of the present embodiment includes a transport shaft 38, a guide and seal mechanism 33, and a compressed air cylinder mechanism (not shown). The mold assembly 23 is placed on the top 37 of the transport shaft 38, and the valve body is rotated clockwise around the open / close shaft 53, and the transport shaft 38 is guided and sealed with the partition valve 47 opened. The mold assembly 23 is transported from the position I of the supply chamber 1 to the position II of the intermediate chamber 2 by being raised along the mechanism 33. When the conveyance is completed, the top 37 of the conveyance shaft 38 is returned to the position I.
[0036]
The forming and conveying mechanism 6 of the optical element forming machine of this embodiment includes a shaft 39, a guide mechanism 34, a compressed air cylinder mechanism (not shown), and shaft seals 35 and 16.
[0037]
At the time of conveyance, the shaft 39 on which the mold assembly 23 is placed on the top 49 is transferred from the conveyance mechanism 8 at the position III of the intermediate chamber 2 to the position IV of the molding chamber 3 from the position III. It is raised along the guide mechanism 34 up to. Due to this rise, the thermocouple 25 is inserted into the thermocouple 25 insertion hole 32 of the mold assembly 23, and the temperature during molding can be measured. At this stage, the upper surface of the upper mold 26 has not yet abutted against the abutting surface 51. In this state, the supply of the inert gas and the heating of the mold assembly 23 are performed. When the supply of the inert gas and the heating are completed, the molding is performed.
[0038]
In the molding, the transport shaft 39 is further moved upward from the state where the transport is completed, and the upper molding die 26 is abutted against the abutment surface 5. Further, by applying a driving force to move the transport shaft 39 upward, the upper forming die 26 and the lower forming die 27 move relative to the glass base material 29, and the upper forming die 26 and the lower forming die The mold 27 comes into contact with and adheres to the glass base material 29 to form the glass base material 29. When the molding is completed, the top 49 of the transport shaft 39 is lowered to return the mold assembly 23 to the position III.
[0039]
As described above, the molding chamber 3 is provided on the intermediate chamber 2, and the molding and transport mechanism 6 further transports the molding die assembly 23 between the intermediate chamber 2 and the molding chamber 3, and transfers the molding die assembly 23. Since the pressing between the upper mold 26 and the lower mold 27 can be performed by the same member, a space-saving and inexpensive optical element molding machine can be obtained. In addition, in the molding chamber 3, an inert gas is introduced at the time of molding. However, if the inert gas is introduced only in the conventional molding chamber 3, oxygen remains in the molding chamber. However, in the present optical element molding machine, the supply chamber 1 is once evacuated to remove oxygen as much as possible, so that oxidation generated during molding can be prevented as much as possible. .
[0040]
The transport mechanism 7 of the optical element molding machine according to the present embodiment includes a transport shaft 40, a guide mechanism 36, and a compressed air cylinder mechanism (not shown). In the transfer, the valve body is rotated counterclockwise around the opening / closing shaft 54, and is delivered from the transfer mechanism 8 at the position V of the intermediate chamber 2 with the partition valve 48 opened, and is transferred to the top 52. The transport shaft 40 on which the mold assembly 23 is placed is lowered from the position V to the position VI of the unloading chamber 4. When the front door of the extraction chamber 4 is opened, the mold assembly 23 can be removed from the top 52.
[0041]
In the optical element molding machine of the present embodiment, in order to heat and mold the mold assembly 23 under the condition that the active gas such as oxygen is reduced as much as possible, the molding chamber 3 is located between the intermediate chamber 2 and the supply chamber 1. Pressure differences are provided between the intermediate chamber 2 and between the intermediate chamber and the discharge chamber 4. That is, in the optical element molding machine of the present embodiment, for example, when the mold assembly 23 is transported from the supply chamber 1 to the intermediate chamber 2, the amount of active gas such as oxygen flowing from the supply chamber 1 to the intermediate chamber 2 is reduced. For this reason, the pressure in the intermediate chamber 2 is higher than the pressure in the supply chamber 1. The higher the pressure difference between the intermediate chamber 2 and the supply chamber 1 is, the higher the effect of preventing the inflow of the active gas is. However, if the pressure difference is too high, the inert gas blows out when the partition valve 47 is opened, which is not preferable. Also, it is not preferable in that the amount of inert gas dissipated when the front door of the supply chamber 1 is opened to set the mold assembly 23 is increased. This also applies to the case where the mold assembly 23 is taken out to the outside in the take-out chamber 4. Conversely, if the pressure difference is too low, the effect of preventing the inflow of the active gas decreases. A preferable pressure difference is 1 hPa or more and 10 hPa or less. For the same reason, it is preferable that the pressure of the molding chamber 3 be higher than the pressure of the intermediate chamber 2 by 1 hPa to 10 hPa, and the pressure of the intermediate chamber 2 be higher than the pressure of the extraction chamber 4 by 1 hPa to 10 hPa. It is preferred that
[0042]
In addition, partition valves 47 and 48 are provided between the intermediate chamber 2 and the supply chamber 1 and between the intermediate chamber 2 and the take-out chamber 4 to prevent the inert gas existing in the intermediate chamber 2 from being carelessly consumed. ing. In particular, the supply chamber 1 is evacuated to remove oxygen from the mold assembly 23. At that time, wasteful release of the inert gas can be suppressed.
[0043]
With this configuration, the purity of the inert gas in the intermediate chamber 2 is higher than the purity of the inert gas in the supply chamber 1 and the extraction chamber 4, and the purity of the inert gas in the molding chamber 3 is adjusted to the level of the intermediate chamber 2. Can be higher than the purity of the inert gas.
[0044]
The supply chamber 1 and the unloading chamber 4 must be kept at atmospheric pressure when the mold assembly 23 is set and unloaded. For this purpose, it is preferable that the pressure of the inert gas in the supply chamber 1 and the discharge chamber 4 be approximately atmospheric pressure.
[0045]
The optical element molding machine of the present embodiment is provided with a pressure controller and a gas flow controller in the inert gas introduction units 10, 11, 12, and 13 for performing the above-described pressure adjustment. The discharge units 14 and 15 are provided with gas flow controllers.
[0046]
In addition, as the inert gas used in the optical element molding machine of the present embodiment, a high-purity nitrogen gas is preferable in terms of the consumption amount, but a high-purity argon, a rare gas such as neon may be used if necessary. .
[0047]
The optical element molding machine of the present embodiment performs molding in the following procedure. Hereinafter, the molding process will be described with reference to FIGS. 1, 2, 3, and 4.
(1) First, the mold member 23 is set at the position I in the supply chamber 1 by hand or by an automatic supply machine.
(2) Next, the supply chamber 1 is evacuated by the vacuum pump 9, and when the vacuum is reached, the evacuation is stopped.
(3) Inert gas is introduced from the inert gas introduction unit 10, the partition valve 47 is opened in a state where the pressure difference with the intermediate chamber 2 is set to a predetermined value, and the transfer mechanism 5 moves the mold assembly 23 to the position I. To the position II, and transfers the mold assembly 23 to the transfer mechanism 8 at the position II. After the transfer, the top 37 of the transport mechanism 5 is returned to the supply chamber, and the partition valve 47 is closed.
(4) The transport mechanism 8 transports the mold assembly 23 to the position III and transfers it to the molding and transport mechanism 6.
(5) The forming / transporting mechanism 6 moves the forming die assembly 23 from the position III to the position IV. At this position, inert gas replacement and heating of the mold assembly 23 are performed, and after the inert gas replacement and heating are completed, molding is performed.
(6) When the molding is completed, the shaft 39 is lowered, and the mold assembly 23 is returned from the position IV to the position III.
(7) The forming and conveying mechanism 6 transfers the forming die assembly 23 to the conveying mechanism 8 at the position III.
(8) The transport mechanism 8 transports the formed mold assembly 23 from the position III to the position V ′.
(9) The transport mechanism 8 transfers the mold assembly 23 to the cooling mechanism 17 at the position V ′, and cools the mold assembly 23 by the cooling mechanisms 17 and 18.
(10) The transport mechanism 8 receives the cooled mold assembly 23 from the cooling mechanism 17 and transports it from the position V ′ to the position V.
(11) The transport mechanism 8 transfers the mold assembly 23 to the transport mechanism 7 at the position V.
(12) The transport mechanism 7 transports the mold assembly 23 from the position V to the position VI while the partition valve 48 is open. After the transfer, the partition valve 48 is closed.
(13) The front door is opened at the position VI, and the mold assembly 23 that has completed the molding process is taken out.
[0048]
As described above, (1) processing at positions I and II, (2) processing at positions III and IV, (3) processing at position V ', (4) processing at positions V and VI Can be performed without interfering with each other. That is, since these four processes can be performed in parallel, the optical element molding machine of the present embodiment can simultaneously process four molding die assemblies in parallel.
[0049]
Therefore, the optical element molding machine of the present embodiment has a large number of productions (high throughput).
[0050]
In addition, the optical element molding machine of the present embodiment does not expose the molding chamber 3 to the atmosphere, but sets the intermediate chamber 2 to a higher pressure than the supply chamber 1 and the extraction chamber 4 without exposing the molding chamber 3 to the atmosphere. And the pressure difference is taken twice. Further, since the supply chamber 1 is once evacuated after setting the mold assembly and an inert gas atmosphere is formed after degassing the active gas such as oxygen, the molding is performed even when the mold assembly is set or taken out. Since the amount of active gas such as oxygen flowing into the inert gas atmosphere in the chamber 3 is extremely small, the upper mold 26 and the lower mold 27 hardly oxidize. Therefore, the optical element formed by the above steps using the optical element forming machine of the present embodiment does not have a cloudy optical surface which is a formed surface.
[0051]
Further, the optical element molding machine of the present embodiment is molded using the molding assembly 23. As can be seen from FIG. 3, since the sleeve 28 has a role of a guide for the molding die 26 in the molding die assembly 23, the inclination of the upper molding die 26 and the lower molding die 27 is small. The molded optical element has less eccentricity than the machine.
[0052]
The optical element molding machine of this embodiment can form a high-quality optical element with no cloudiness and little eccentricity.
[Second embodiment]
The optical element molding machine of the present embodiment will be described with reference to FIG.
[0053]
The optical element molding machine of this embodiment has a configuration in which the vacuum pump 9 is removed from the supply chamber 1 and an inert gas discharge section is newly provided in FIG. The other configurations of the intermediate chamber 2, the molding chamber 3, the unloading chamber 4, the transport mechanism 5, the transport mechanism 6, the transport mechanism 7, and the transport mechanism 8 are the same as those of the first embodiment.
[0054]
In the optical element molding machine according to the present embodiment, in the molding step, in the step (2) in the molding step according to the first embodiment, “Next, the supply chamber 1 is evacuated by the vacuum pump 9 and when the vacuum is reached, Stop exhaust. "The process proceeds to the step (3) and subsequent steps without performing the step. Accordingly, since the amount of the active gas such as oxygen gas in the inert gas atmosphere in the supply chamber 1 in the step (3) is not so small as in the first embodiment, it flows into the molding chamber through the intermediate chamber 2. The amount of the active gas such as oxygen is larger than in the first embodiment.
[0055]
However, the optical element molding machine of the present embodiment can simultaneously process four mold assemblies in parallel. Therefore, the optical element molding machine of the present embodiment has a large number of productions (high throughput).
[0056]
In addition, the optical element molding machine of the present embodiment does not expose the molding chamber 3 to the atmosphere, but sets the intermediate chamber 2 to a higher pressure than the supply chamber 1 and the extraction chamber 4 without exposing the molding chamber 3 to the atmosphere. And the pressure difference is taken twice. Due to the double structure, the amount of the active gas such as oxygen flowing into the inert gas in the molding chamber 3 is small even when the mold assembly is set or taken out. Oxidation hardly occurs, and the optical element molded by using the optical element molding machine of the present embodiment is not as large as that of the first embodiment. However, the molded optical surface has almost no cloud.
[Third embodiment]
The optical element molding machine of the present embodiment will be described with reference to FIG.
[0057]
In FIG. 1, the optical element molding machine of this embodiment removes the vacuum pump 9 from the supply chamber 1 and further removes the molding chamber 3 from the configuration of the second embodiment in which an inert gas discharge part is newly attached. The mold assembly 23 is formed at the position III in the intermediate chamber 2. The optical element molding machine of the present embodiment includes a supply chamber 1, an intermediate chamber 2, and an extraction chamber 3. In order to mold the mold assembly 23 at the position III, the intermediate chamber is provided with a heater for heating the mold assembly 23 and a thermometer for measuring the temperature during molding. Since there is no molding chamber 3, there is no need to convey between the position III and the position IV, and 6 is a pressurizing mechanism for a molding die dedicated to molding.
[0058]
The optical element molding machine of the present embodiment can simultaneously process four molding die assemblies 23 at the same time. Therefore, the optical element molding machine of the present embodiment has a large number of productions (high throughput).
[0059]
Further, in the optical element molding machine of the present embodiment, the intermediate chamber 2 (which performs molding in the present embodiment) is set at a higher pressure than the supply chamber 1 and the extraction chamber 4 without exposing to the atmosphere. During the set and take-out, since the amount of the active gas such as oxygen flowing into the inert gas atmosphere in the intermediate chamber 2 is small, the upper mold 26 and the lower mold 27 are less likely to be oxidized. Although the optical element molded using the optical element molding machine is not the same as that of the second embodiment, the optical surface which is the molded surface has less cloudiness.
[Fourth embodiment]
The optical element molding machine of the present embodiment will be described with reference to FIG.
[0060]
The optical element molding machine of this embodiment is different from the configuration of the second embodiment in which the vacuum pump 9 is removed from the supply chamber 1 and an inert gas discharge part is newly attached in FIG. 4 is removed, and the supply chamber 1 and the intermediate chamber 2 are configured. In the present embodiment, the mold assembly 23 is set at the position I, the inert gas replacement, the heating and the molding are performed at the position II in the intermediate chamber 2, and then the material is transferred again to the position I in the supply chamber 1. , From the position I of the supply chamber 1. In such a configuration, the mold assembly 23 can be transported only by the transport mechanism 5. Therefore, the optical element molding machine of the present embodiment does not have the molding and transport mechanism 6, the transport mechanism 7, and the transport mechanism 8. In order to form the mold assembly 23 at the position II, a heater for heating the mold assembly 23 and a thermometer for measuring the temperature during molding are provided at the position II.
[0061]
In the optical element molding machine of the present embodiment, since the intermediate chamber 2 for molding is not exposed to the atmosphere, but has a higher pressure than the supply chamber 1 for supplying and removing the mold assembly 23, the mold assembly 23 Since the amount of the active gas such as oxygen flowing into the intermediate chamber 2 (forming at the position of II) is small even at the time of setting and taking out, the upper molding die 26 and the lower molding die 27 hardly oxidize. The optical element molded by using the optical element molding machine of the embodiment has almost no clouding on the optical surface which is the molded surface as in the third embodiment.
[0062]
However, since the optical element molding machine of the present embodiment cannot process the mold assembly 23 in parallel, the throughput is not so high, but has a higher throughput than the conventional optical element molding machine.
[0063]
Further, in the optical element molding machines of the first to fourth embodiments, since the molding dies such as the upper molding die 26 and the lower molding die 27 are hardly rusted, the maintenance time for removing rust from the molding dies is reduced. be able to.
[0064]
【The invention's effect】
According to the present invention, a high-purity inert gas atmosphere can be formed around the mold during heating and molding of the mold, so that a high-quality optical element with less oxidation of the mold and less clouding can be formed. can do.
[Brief description of the drawings]
FIG. 1 is a side view showing an optical element molding machine according to a first embodiment of the present invention.
FIG. 2 is a view showing a transport mechanism 8 of the optical element molding machine according to the first to third embodiments of the present invention.
FIG. 3 is a view showing a mold assembly used in an optical element molding machine according to first to fourth embodiments of the present invention.
FIG. 4 is a view around a heater of the optical element molding machine according to the first and second embodiments of the present invention.
[Explanation of symbols]
1 supply room
2 Intermediate room
3 Molding room
4 extraction room
5, 7, 8 transport mechanism
6 Forming and conveying mechanism
9 vacuum pump
10, 11, 12, 13 Inert gas inlet
14, 15 Inert gas discharge section
16, 35 Shaft seal
17, 18 Cooling mechanism
19, 20, 21, 22 Pressure gauge
23 Mold assembly
24 Heater
25 thermocouple
26 Upper mold
27 Lower mold
28 sleeve
29 Glass base material
30 carriage
31 Hollow for transport
32 Insertion hole for thermocouple 25
33, 36 Guide and seal mechanism
34 Guide mechanism
37, 49, 52 Top
38, 40 transport axis
39 axes
41 Ball screw
42 motor
43 Moving mechanism
44 Grip
45 Indicates opening and closing of grip
46 Indicates movement of the gripper 44 to the gripping position A and the retreat position B
47, 48 Partition valve
50 gas flow path
51 contact surface
53, 54 Gate valve opening / closing shaft
55 quartz tube
56 refractories
57 Arrow

Claims (9)

An inert gas supply unit for supplying an inert gas that is unlikely to cause a chemical reaction at least with a molding die or a glass material at a high temperature; and supplying a pressing force to the glass material via the molding die while heating the molding die and the glass material. A molding chamber having molding means, and an optical element molding machine having at least a supply chamber for supplying the molding die and the glass material to the molding machine,
An optical element molding machine wherein the supply chamber and the molding chamber are set so that the pressure in the molding chamber is relatively large. The apparatus according to claim 1, further comprising an isolating means provided between the supply chamber and the molding chamber, the isolation means being capable of isolating at least when the molding die or the glass material is not transferred from the supply chamber to the molding chamber. 2. The optical element molding machine according to 1. Further, an extraction chamber for taking out the glass material and the molding die molded in the molding chamber from the optical element molding machine is provided separately from the supply chamber, and the extraction chamber is set at a lower pressure than the molding chamber. The optical element molding machine according to claim 1, wherein: An isolator between the molding chamber and the unloading chamber is provided, which can isolate the molding chamber and the unloading chamber at least except during transfer of the molding die or the glass material. 4. The optical element molding machine according to 3. The optical element molding machine according to claim 1, further comprising a cooling means for cooling at least the molding die and the glass material transferred from the molding chamber, between the molding chamber and the unloading chamber. 2. The optical element molding machine according to claim 1, wherein a transfer chamber provided with a transfer means for transferring the molding die or the glass material is provided between the supply chamber and the molding chamber. The transfer chamber is also located between the molding chamber and a take-out chamber for taking out the molding material and the molding die from the optical element molding machine in the molding chamber, and the molding die and the glass material are provided in the conveyance chamber. 7. The optical element molding machine according to claim 6, further comprising cooling means for cooling the optical element. The optical element molding machine according to claim 1, wherein the supply chamber further includes a decompression unit capable of reducing the pressure after the molding die or the glass material is introduced. The optical element molding machine according to claim 3, wherein the extraction chamber includes an exhaust unit that exhausts an inert gas supplied from the molding chamber.

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