JP4346624B2 - Method for producing glass molded body and method for producing optical element - Google Patents

Description

  The present invention relates to a method for continuously producing a glass molded body from molten glass, and a method for producing an optical element by precision press-molding a glass molded body obtained by the method.

A glass precision press molding method is known as a method for mass-producing an optical element that takes time and effort for processing an aspheric lens with high productivity. This method is a method of processing the molding surface of a press mold with high accuracy, press-molding a glass material called a preform in a heated state, forming the entire shape of the glass, and accurately transferring the molding surface to the glass. It is.
The preform is manufactured using glass that satisfies optical characteristics required for an optical element. As a preform manufacturing method, molten glass is poured into a mold and molded, and the resulting molded body is cut, ground and polished, and a molten glass lump corresponding to one preform is separated from the molten glass flowing out. In addition, there is a method of forming into a preform in the process of cooling the obtained molten glass lump. The latter method has an advantage that a preform can be directly produced from molten glass. Such a method is disclosed in, for example, Patent Document 1.
JP 2003-40632 A

  The method of directly forming a preform from a molten glass lump is excellent in mass productivity. However, as the demand for optical elements such as lenses mounted in digital imaging devices and mobile phones in recent years has increased, preforms have been formed. It is demanded to further improve the mass productivity.

  For this purpose, it is desired to separate the molten glass ingots from the continuously flowing molten glass and to shorten the separation interval to increase the throughput. The molten glass lump separated one after another is sequentially formed into a glass molded body by a plurality of circulating molds. At this time, a plurality of molds are arranged at predetermined intervals on the circumference of the turntable. A plurality of molds are sequentially moved to a fixed stop position in synchronization by rotating the table with an index that alternately repeats rotation and stop at a constant angle.

  It is desirable to supply the molten glass to the mold and take out the glass molded body from the mold. However, since the mold is moving in synchronization, the mold is moved to the mold. The supply of molten glass and the removal of the glass molded body from the mold must be performed simultaneously.

  When taking out the glass molding from the mold on the turntable using the robot, the manipulator of the robot performs the following operations until the next mold is transported to the take-out position, that is, (1) being stopped. (2) holding the molded body, (3) taking out the molded body before the mold starts moving, (4) transferring the molded body to the next step, (5) The operation of releasing the holding of the molded body and (6) returning to the initial position for the next removal must be terminated.

  However, when the separation interval of the molten glass lump is further shortened in order to increase the throughput, the operation times of the above (1) to (6) for taking out the formed body are relatively compared with the separation interval of the molten glass lump. Since it becomes long, the operation of the robot will not be in time for taking out the next molded body. As described above, there is a problem that the step of taking out the glass molded body becomes a rate-determining method and the speeding up of the entire manufacturing process of the molded body is limited.

  The present invention has been made in order to solve the above-mentioned problems. From the glass molded body obtained by the method and the method for producing a glass molded body, the production speed of the glass molded body is increased and the mass productivity is improved. An object is to provide a method of manufacturing an optical element.

  In order to solve the above-mentioned problems, the present inventors diligently examined. In the manufacturing process of the glass molded body, after applying the wind pressure to the obtained glass molded body and blowing it away from the mold, a specific treatment was applied to the blown molded body. It has been found that the time required for taking out the glass molded body can be shortened by sucking and accommodating the obtained glass molded body, and the present invention has been completed based on this finding.

That is, the present invention
(1) A method for producing a glass molded body by molding a molten glass lump in a cooling process,
One after another beat drop a molten glass gob having a same mass from molten glass continuously flows out of the nozzle,
Circulating and using a plurality of molds that move synchronously to mold the molten glass lump to obtain a glass molded body of 30 mg or less ,
A method for producing a glass molded body, characterized in that wind pressure is applied to the obtained glass molded body and blown off from a mold, and the blown molded body is accommodated in a liquid,
(2) the glass melt gob while molding the glass shaped material of a spherical, glass molded body according to the above (1), wherein the blow off from the mold by submerge the airflow on the lower side of the glass shaped material Manufacturing method,
( 3 ) A method for producing a glass molded body by molding a molten glass lump in the cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
Wind pressure is applied to the obtained glass molded body and blown off from the mold, the blown molded body is received by a bowl-shaped passage having a recess, cooled while moving in the depression, and the bowl-shaped passage is placed on a horizontal surface. In contrast, it is arranged so as to have an inclination angle, and by adjusting the inclination angle, the movement speed of the glass molded body moving through the bowl-shaped passage is adjusted, and the glass molded body is prevented from cracking due to heat shock. A method for producing a glass molded article,
( 4 ) The method for producing a glass molded body according to ( 3 ) above, wherein the glass molded body cooled while moving in the recess of the bowl-shaped passage is contained in a liquid.
( 5 ) A method for producing a glass molded body by molding a molten glass lump in a cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
A method for producing a glass molded body, which is characterized by sucking and containing the obtained glass molded body,
( 6 ) A method for producing a glass molded body by molding a molten glass lump in the cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
A method for producing a glass molded body characterized in that wind pressure is applied to the obtained glass molded body and blown off from a mold, and the blown-off molded body is sucked and accommodated, and ( 7 ) above (1) to ( 6 ) manufactures Riga lath shaped body by the method according to any one of, there is provided a method of manufacturing an optical element characterized by precision press molding the resulting glass shaped body.

  According to the present invention, it is possible to provide a method for producing a glass molded body in which the production speed of the glass molded body is increased and mass productivity is improved, and a method for producing an optical element from the glass molded body obtained by the method. Can do.

  The first to fourth methods for producing a glass molded body according to the present invention are different in steps after the molten glass lump is formed into a glass molded body, but are common up to the process of forming the molten glass lump into a glass molded body. ing. For this reason, the matter common to the manufacturing method of the 1st-4th glass molded object of this invention is demonstrated first.

  The manufacturing method of the 1st-4th glass molded object of this invention is a method of shape | molding a molten glass lump in a cooling process, and manufacturing a glass molded object, Comprising: The same mass melts from the molten glass which flows out continuously. The glass lump is separated one after another, and a plurality of molds moving synchronously are circulated to form the molten glass lump to obtain a glass molded body.

  First, a glass raw material prepared so as to obtain a target glass composition is introduced into a melting vessel, heated, melted, clarified and homogenized to obtain a molten glass. Then, the molten glass is guided from the pipe attached to the melting vessel at a constant flow rate at a temperature at which the glass does not devitrify, and continuously flows out from the pipe outlet. In order to obtain a glass molded body with a constant mass, current is passed through platinum or a platinum alloy constituting the pipe to generate Joule heat to heat the pipe, the pipe is heated by a high frequency induction heating method, It is preferable to maintain a constant flow rate of molten glass per unit time by heating the surface and controlling the temperature.

  Below the pipe, an apparatus in which a plurality of molds that move in synchronization is arranged. A typical example of such a device is a turntable, which will be described below on the assumption that the turntable is used.

  As shown in FIG. 1, the respective molds 2 are arranged at equal intervals on the circumference around the rotation axis of the turntable 1, and the respective molds 2 are synchronized by rotating the index of the turntable 1. To the corresponding stopping position. In the turntable 1 shown in FIG. 1, a total of 24 molding dies 2 are arranged and used in a circulating manner.

  One of the stopping positions is allocated to the casting position, and the pipe outlet is located above the mold 2 that stops at the casting position.

  As an example of a method for supplying molten glass lump to the mold 2, the mold 2 located below the pipe outlet is raised and brought close to the pipe outlet, and the lower end of the molten glass flowing out from the outlet is supported. Next, a method of supplying the molten glass ingot to the mold by separating the molten glass by rapidly dropping the mold. This method is preferably performed while the mold is stationary. According to this method, it is possible to obtain a molten glass lump having a larger mass (for example, about 300 to 1500 mg) and a relatively large size than the molten glass lump naturally dropped from the pipe outlet. In order to increase the mass accuracy of the glass molded body, before starting the mass production of the glass molded body 3, the distance between the pipe outlet and each mold 2 when the mold 2 is raised is adjusted to be equal. Is preferred. In the above example, the mold 2 itself is used as a receiving member. However, a molten glass lump can be separated using a separately provided receiving member and then supplied to the mold.

Moreover, the method of naturally dripping a molten glass from a pipe outlet to the shaping | molding die 2 and obtaining a molten glass lump can also be mentioned, The glass molded object 3 obtained by shape | molding the molten glass lump obtained by this method is a shaping | molding. The size is suitable for blowing (or sucking) from the mold 2 (for example, about 50 to 500 mg). Since the weight of the naturally dripped molten glass lump is proportional to the diameter of the pipe outlet, the outlet diameter is selected in accordance with the weight of the obtained molded body. The molten glass lump that drops spontaneously may be dropped directly on the mold, or may be supplied to the mold 2 after being brought into contact with the receiving member once. Further, the glass flow may be temporarily supported by the receiving member and then dropped before being cut and separated from the molten glass flow.

  In this way, the molten glass lump is supplied to the mold 2 at the casting position of the turntable 1, but the mold 2 to which the molten glass lump is supplied is unloaded from the casting position by the rotation of the turntable and molded in an empty state. Mold 2 is carried into the casting position. The mold 2 on which the molten glass lump is placed forms the molten glass lump into the glass molded body 3 while repeatedly moving and stopping.

  Examples of the method for obtaining the glass molded body 3 from the molten glass lump include the following first to third molding methods.

  The first forming method is a method in which gas is blown from a forming die, an upward wind pressure is applied to the glass lump, and the glass lump is floated on the forming die to form, and in this method, The surface becomes a free surface.

  In the second molding method, gas is blown out from the recess of the mold and an upward wind pressure is applied to the glass block. In this method, the shape of the recess of the mold 2 is substantially inverted conical (the horizontal cross section of the recess of the mold). Means a shape in which the diameter of the circle increases from bottom to top (toward the gas ejection direction), as shown in FIG. 2 (a), from bottom to top ( (Toward the gas ejection direction) (preferably a substantially trumpet shape in which the increasing rate of the diameter of the circle increases). The gas outlet is provided at the bottom of the substantially inverted conical recess. In this method, when the glass lump is lowered toward the lower part of the recess, it rises due to a strong upward wind pressure, and when the glass lump is raised, the wind pressure is decreased and lowered so that it moves up and down in the recess. The glass lump is rotated at random by this vertical movement, and is formed into a spherical glass molded body 3.

  The opening angle θ of the inverted conical recess is preferably about 45 to 15 °. Within this angle range, the recess shape has a shape from the bottom upward (as shown in FIG. 2B). It may have a shape in which the increase rate of the diameter of the circle decreases (toward the ejection direction). Moreover, as shown in FIG.2 (c), the recessed part shape may have roundness in the gas jet nozzle vicinity. On the other hand, in order to apply wind pressure to the glass molded body 3 so as to be easily blown away, as shown in FIGS. 2A to 2C, the upper end of the inverted conical recess is rounded and the surface of the rounded portion is mirror-polished. It is preferable. This is because if there is an edge at the upper end of the recess, a spherical glass molded body will hit the edge and scratches will easily occur. Moreover, in order to stabilize the taking-out direction of the glass molded object 3, you may form a guide groove in the upper end of an inverted conical recessed part. The gas flow rate supplied to the mold 2 is selected so that the molten glass lump is rotated at a high speed while the molten glass lump is substantially in a floating state. Just choose.

  The third molding method is a method in which a molten glass lump on a molding die is press-molded with an opposing mold facing the molding die.

  After forming by the above first to third forming methods, it is preferable to take out the target glass molded body from the mold at the stage where it is cooled to such an extent that it is not deformed by the force at the time of taking out.

Next, the manufacturing method of each glass molded body is demonstrated.
The first method for producing a glass molded body is characterized in that wind pressure is applied to the obtained glass molded body and blown off from a mold, and the blown molded body is accommodated in a liquid.
Hereinafter, the manufacturing method of a 1st glass molded object is demonstrated based on drawing.

FIG. 3 shows a glass molded body 3 produced from a molten glass lump using the second molding method. The spherical glass molded body 3 before being taken out is in a floating state by an air flow injected from the bottom of the mold 2. Therefore, as shown in FIG. 4, the glass molded body 3 can be blown off from the molding die 2 if the airflow ejected from the gas injection device 4 is squeezed into the lower side of the spherical glass molded body 3. At this time, the spherical glass molded body 3 can be landed in the intended direction and distance by finely adjusting the direction and strength of the airflow injected from the gas injection device 4.

  Further, as shown in FIG. 5, when an air flow having a large flow velocity is passed from the gas injection device 4 above the mold 2, the upper part of the spherical glass molded body 3 becomes negative pressure and the spherical glass molded body 3 is moved upward. The spherical glass molded body 3 that has jumped out in the direction can be blown off in the direction of the airflow ejected from the gas injection device 4.

  The gas injection device 4 may be used in combination with the suction nozzle 5. For example, as shown in FIG. 6, by generating a negative pressure inside the suction nozzle 5 installed on the mold 2, the spherical glass molded body 3 is sucked and raised, and the horizontal direction is adjusted in accordance with the timing. The spherical glass molded body 3 may be taken out by applying wind pressure from the gas injection device 4. Further, as shown in FIG. 7, if the flow velocity of the air flow ejected from the concave portion of the mold 2 is increased to raise the spherical glass molded body 3, and the wind pressure from the gas injection device 4 is applied from the lateral direction, the spherical glass molded body is applied. 3 can be taken out.

  In this way, by blowing off the obtained glass molded body from the mold, the separation interval of the molten glass lump is further shortened, and even if the throughput is improved, the process of taking out the glass molded body becomes rate-limiting. Therefore, it is possible to realize a high speed of the entire manufacturing process of the molded body. Further, since the molded body is blown away by non-contact means, if the molded body is blown away using a clean gas, it is possible to prevent the dust in the working environment from being fused to the glass surface when the molded body is taken out. it can.

  As shown in FIG. 8, the glass molded body 3 blown off by applying wind pressure is accommodated in the liquid 6. As the liquid 6 containing the glass molded body 3, a low boiling point liquid such as pure water, ethanol or ether, a liquefied gas such as liquid nitrogen, or the like can be used.

  By dropping the glass molded body into the liquid, the glass molded body can be accommodated without giving an impact, the cooling of the glass molded body can be promoted, and further, by contacting with the collection container Occurrence of dirt on the glass molded body can be prevented.

  In the case of producing a spherical glass molded body, a method of cooling a molten glass lump directly into a liquid and making it spherical by the surface tension of the glass is also conceivable. However, in this method, when trying to obtain a glass molded product with a high sphericity, only a small-capacity glass molded product can be obtained, and when the viscosity of the molten glass is too low, The molten glass lump may be deformed by the impact at the time of dropping, and the sphericity of the obtained glass molded body may be deteriorated. Furthermore, depending on the volume of the molten glass lump, the glass temperature at the time of liquid entry, the type of liquid, and the temperature of the liquid, the glass lump may be broken by a heat shock at the time of liquid entry.

According to the first method for producing a glass molded body of the present invention, since a molten glass lump is molded on a mold and taken out, it is possible to obtain a spherical glass molded body of 100 mg or more that cannot be spheroidized only by surface tension. It becomes possible. In addition, when the glass molded body spheroidized by the mold is cooled to at least the softening temperature or lower on the mold and taken out, the sphericity of the glass molded body is reduced due to the impact of dropping on the liquid. Can be prevented. Furthermore, if the glass is sufficiently cooled and the temperature of the glass at the time of taking out is lowered, there is no concern that the glass molded body will break due to heat shock at the time of liquid entry. However, when the molding efficiency is increased to the limit (when the separation interval of the molten glass lump is shortened), it is difficult to lower the temperature of the glass molded body. In such a case, it is desirable to use a liquid having a low boiling point such as alcohol, a liquid heated to the vicinity of the boiling point, or a boiling liquid as the liquid to which the glass molded body is dropped. When such a liquid is used, the liquid around the glass molded body is boiled by the heat of the glass, and the glass molded body is wrapped in the gas phase almost simultaneously with the liquid entering, so that the heat shock can be mitigated. However, if the temperature of the glass molded body at the time of entering the liquid can be sufficiently lowered, it is possible to prevent cracking due to heat shock even with pure water or ethanol that is easy to handle. Further, since the gas phase around the liquid or the glass molded body becomes a cushion, even if the glass molded bodies are in contact with each other or collide with each other as shown in FIG. 8, the possibility that the glass molded body is scratched is low. Become.

Next, the manufacturing method of the 2nd glass molded object is demonstrated.
In the second method for producing a glass molded body, wind pressure is applied to the obtained glass molded body and blown off from a mold, and the blown molded body is received by a bowl-shaped passage having a recess, and cooled while moving in the recess. It is characterized by this.

  In the second method for producing a glass molded body, the method of applying wind pressure to the glass molded body and blowing it away from the mold is the same as that described in the description of the method for producing the first glass molded body.

  When the molding efficiency of the glass molded body is increased to the limit (when the separation interval of the molten glass lump is shortened), the glass cooling body temperature at the time of take-out rises slightly because the cooling time of the glass is shortened, Dust in the environment tends to be burned onto the surface of the glass molded body. Moreover, when the temperature of the glass molded body is high, the problem of cracking due to heat shock tends to occur. Furthermore, since the glass molded body blown off by applying wind pressure flies at a high speed, if it is recovered as it is, it may collide with the collection container or the previously extracted glass molded body and scratch the surface of the glass molded body.

  In order to solve the above problems, in the second method for producing a glass molded body of the present invention, as shown in FIG. 9, the glass molded body 3 blown off by wind pressure is received by a bowl-shaped passage 8 having a recess 7, The glass molded body 3 is cooled while moving in the recess.

  The bowl-shaped passage 8 is preferably wide so that the landing area of the glass molded body 3 can be increased. Further, for example, as shown in FIG. 9, the spherical glass molded body 3 can be rolled in the longitudinal direction of the bowl-shaped passage 8 by arranging the bowl-shaped passage 8 so as to have an inclination angle with respect to the horizontal plane. The glass molded body 3 can be moved in the intended direction from the landing point. The moving speed of the glass molded body 3 can be adjusted by the inclination angle of the bowl-shaped passage 8, and the moving speed is sufficiently decelerated, and the cooling time of the spherical glass molded body 3 is sufficiently secured to lower its temperature. It is desirable. As a result, it is possible to prevent the above-described seizure of dust on the glass molded body and cracking of the glass molded body due to collision and heat shock while shortening the time for taking out the glass molded body.

  The recess 7 of the bowl-shaped passage preferably has a U-shaped or V-shaped cross section when viewed from the longitudinal direction of the bowl-shaped passage. Moreover, the bowl-shaped channel | path may have a ceiling part as needed, In this case, a tubular channel | path will be provided with a bowl-shaped channel | path and a ceiling part.

  When the bowl-shaped passage having the recess has the above shape, the moving direction and moving speed of the glass molded body can be stabilized even if the landing position of the glass molded body is somewhat inaccurate. Further, the passage does not need to be linear, and by making it a curve, a spiral or the like, it is possible to increase the moving distance and effectively reduce the moving speed to further promote the cooling of the glass.

When the glass molded body 3 moves in the recess 7 of the bowl-shaped passage, there is a possibility that the spherical glass molded body 3 will be seized by dust adhering to the surface of the recess. Accordingly, it is preferable to form a gas cushion by blowing clean gas onto the surface of the recess 7 of the bowl-shaped passage or jetting gas from the surface of the recess 7 of the bowl-shaped passage. Moreover, it is preferable to produce the surface of the recessed part 7 of a bowl-shaped channel | path with soft materials, such as a heat resistant resin and a graphite, and to prevent the seizure and damage in the glass molded object 3.

  The glass molded body 3 is accommodated in the container 9 or the like after moving through the bowl-shaped passage 8. In this case, from the viewpoint of preventing breakage and seizure in the glass molded body, the surface of the container 9 is also preferably formed of a soft material, and it is preferable that gas is ejected from the surface of the container 9 to form an air cushion. .

  In addition, it is preferable to increase the floating gas flow rate of the glass molded body to be passed through the mold and sufficiently reduce the temperature of the glass or preheat the container to prevent cracking of the glass due to heat shock at the time of contact with the container. . However, when the obtained glass molded body is a spherical glass molded body of 20 mg or less, the glass is hardly cracked because the cooling rate is high and it is resistant to heat shock.

  As shown in FIG. 10, the glass molded body cooled while moving in the recess 7 of the bowl-shaped passage 8 is preferably accommodated in the liquid 6 in the container 9.

  By dropping the glass molded body into the liquid, the glass molded body can be accommodated without giving an impact, the cooling of the glass molded body can be promoted, and further, by contacting with the collection container Occurrence of dirt on the glass molded body can be prevented.

  As described above, in the method in which the glass molded body 3 is put into the liquid 6 without passing through the bowl-shaped passage 8, when the molding efficiency is increased to the limit (when the separation interval of the molten glass lump is minimized), the mold 2 The cooling time above cannot be taken sufficiently, and the glass molded body 3 may be cracked by heat shock when the liquid 6 is charged.

However, in the second method for producing a glass molded body of the present invention, the glass molded body 3 taken out from the mold is cooled while being moved in the concave portion of the bowl-shaped passage 8. The temperature of the glass molded body 3 decreases, and the cooling time of the glass molded body 3 can be extended by the time for moving the bowl-shaped passage 8. For this reason, it becomes possible to accommodate the glass molded body 3 without performing special measures such as making the liquid 6 specific.
As the liquid 6, a low boiling point liquid such as pure water, ethanol or ether, a liquefied gas such as liquid nitrogen, or the like can be used.

Next, the manufacturing method of the 3rd glass molded object is demonstrated.
The third method for producing a glass molded body is characterized by sucking and storing the obtained glass molded body.

  As shown in FIG. 11, the suction device 10 capable of sucking the glass molded body 3 into the interior has a suction pipe 13, and a suction port 11 provided at one end of the pipe is provided in the upper part of the mold 2. Then, by generating a negative pressure inside the suction pipe 13, the glass molded body 3 on the mold 2 is sucked and the glass molded body 3 sucked from the other end of the suction pipe 13 is discharged. If the container 9 etc. are installed below the discharge end of the glass molded body 3, the glass molded body 3 can be easily accommodated.

In the example shown in FIG. 11, a decompression device such as a vacuum generator is connected to the opening provided above the container 9, and a negative pressure is applied to the inside of the container 9 and the suction pipe 13 connected to the container 9. By generating, the spherical glass molded body 3 on the molding die 2 can be sucked, and the glass molded body 3 can be accommodated by sequentially discharging the glass molded body 3 into the container 9 through the suction pipe 13. In this case, the ratio between the inner diameter of the suction pipe 13 and the inner diameter of the pipe connecting the decompression device to the container 9 is adjusted in consideration of the volume of the container 9 or the like. The glass molded body 3 accommodated in the container 9 is adjusted by adjusting the distance of the apparatus from the attachment position to the container 9 or by providing a net-like sheet or the like between the container 9 and the decompression apparatus. It is preferable to prevent movement to the side.

  Since the above method does not use a mechanical device that operates at high speed, the glass molded body 3 can be taken out at the same time as the mold 2 moves to the take-out position even when the separation interval of the molten glass lump is short. Become.

  When the glass molded body is sucked, the glass molded body may be damaged due to a collision with the container to be stored or the glass molded body previously stored in the container. Therefore, it is preferable to use a material softer than glass such as heat-resistant resin or graphite for the container, or to form a gas cushion by ejecting gas from the surface of the container that comes into contact with the glass molded body. Further, it is desirable to separate the landing position of the glass molded body and the storage position after landing so that the glass molded body does not collect at the landing position of the container. For example, if a gentle slope is formed between the landing position and the storage position, the spherical glass molded body can be rolled and moved from the landing position to the storage position.

  On the other hand, when the temperature of the glass molded body at the time of taking out is high, the glass may be cracked by heat shock at the time of contact with the container. Therefore, it is preferable to increase the floating gas flow rate of the glass molded body to be passed through the molding die to sufficiently lower the glass temperature or to warm the container in advance. However, when the obtained glass molded body is a spherical glass molded body of 20 mg or less, the glass is hardly cracked because the cooling rate is high and it is resistant to heat shock.

  The sucked glass molded body may be accommodated in a liquid. In this case, the sucked glass molded body may be accommodated in a container previously filled with the liquid. As the liquid used for housing the glass molded body, a low boiling point liquid such as pure water, ethanol or ether, a liquefied gas such as liquid nitrogen, or the like can be used.

  By dropping the sucked glass molded body into the liquid, the glass molded body can be accommodated without giving an impact, the cooling of the glass molded body can be promoted, and the container can be in contact with the container. It is possible to prevent the occurrence of dirt on the glass molded body due to.

Next, the manufacturing method of the 4th glass molded object is demonstrated.
The fourth method for producing a glass molded body is characterized in that wind pressure is applied to the obtained glass molded body and blown off from a mold, and the blown glass molded body is sucked and accommodated.

  As shown in FIGS. 12 (a) and 12 (b), in the fourth method for producing a glass molded body, molten glass is dropped from a pipe outlet 12 to supply a molten glass lump to the mold 2, and the mold It is desirable to form the molten glass lump while the wind pressure is applied on the surface 2. Since the glass molded body 3 formed from a small glass lump obtained by dripping molten glass can be easily blown off from the mold 2 by applying wind pressure, the glass molded body 3 does not touch the glass molded body in a short time. Can be taken out. If the blown-off glass molded body 3 is sucked and accommodated, it can be efficiently recovered without damaging the glass molded body.

As shown in FIGS. 12 (b) and 12 (c), the gas used for blowing off is preferably injected from the gas injection device 4, and is injected along the inner wall of the recess of the mold 2 to form a glass molded body in the recess. 2 is preferably blown off along the inner wall facing the inner wall from which the gas has been injected. It is preferable to arrange a suction device 10 having a suction port 11 in advance at a position where the glass molded body 3 is blown away. A negative pressure is generated inside the suction device 10 and the blown glass molded body 3 is sucked into the suction port. It is preferable to suck into the suction port 11 by a negative pressure near 11 and pass through the pipe connected to the suction port 11 and accommodate in the container 9. In order not to damage the glass molded body 3, the tube and the container 9 are preferably made of a flexible material.

  In the first, second, and fourth glass molded body manufacturing methods, nitrogen gas, air, or the like can be used as the gas used for blowing the glass molded body, but it should be a dry and clear gas. Further, the gas flow rate at the time of blowing off can be appropriately determined in consideration of the mass of the glass molded body, but is preferably about 10 to 50 L / min (liter / min).

  In the first to fourth glass molded body manufacturing methods, only one gas injection device 4 or suction device 10 may be used, or a plurality of gas injection devices 4 may be used. By using a plurality of units, it is possible to further shorten the time for taking out the glass molded body.

  Examples of the glass molded body obtained by the first to fourth glass molded body manufacturing methods of the present invention include a press molding preform which is a glass material for heating and press molding.

Next, the manufacturing method of the optical element of this invention is demonstrated.
The optical element manufacturing method of the present invention is characterized by precision press-molding the glass molded body manufactured by the first to fourth glass molded body manufacturing methods of the present invention.

  The shape of the glass molded body to be used is desirably determined based on the shape of the target optical element. For example, when molding an optical element having rotational symmetry such as a lens, it is desirable that the shape of the glass molded body used as the preform is also a sphere or a shape having rotational symmetry.

  The glass molded body obtained as described above is precision press-molded to produce an optical element. Known press molding dies and apparatuses used in the precision press molding method and precision press molding can be used. The manufacturing conditions such as molding conditions may be adjusted as appropriate in consideration of the type of glass, the shape and size of the optical element, and the like.

  Examples of the obtained optical element include glass elements constituting an optical instrument, such as optical elements such as lenses, mirrors, gratings, prisms, microlenses, and laminated diffractive optical elements, and preferably lenses. .

Example 1 (Example of manufacturing a glass molded body by the first method for manufacturing a glass molded body)
After cooling and solidifying, a glass lump that becomes a lanthanum borate optical glass having a refractive index (nd) of 1.806 and an Abbe number (νd) of 40.7 is poured into a platinum crucible heated to 1000 ° C. and melted. The solution was clarified and stirred at 1300 ° C. to obtain a uniform glass melt at 1050 ° C.

  Next, a platinum alloy nozzle having an outer diameter of 1.0 mm and a structure in which nitrogen gas can be flowed to the outer periphery of the nozzle tip shown in FIG. 13 is connected to the bottom of the platinum crucible and temperature-controlled at 1000 ° C. Attached. Next, the outflow nozzle portion is heated to 990 ° C. to flow out the molten glass, and by adjusting the flow rate of nitrogen gas flowing to the tip of the nozzle, 28 mg of molten glass is dropped at intervals of 0.5 seconds. Obtained.

On the other hand, as shown in FIG. 1, a total of 24 molding dies 2 were evenly arranged in the vicinity of the circumference of the circular turntable 1. As shown in FIG. 2A, the mold 2 is formed with a substantially trumpet-shaped inverted conical recess (θ = 35 °), which is 1.2 L / L from the hole provided at the bottom of the center of the recess. Minute nitrogen gas was blown out. The mold 2 is moved directly below the outflow nozzle, and a molten glass lump is dripped and inserted into the trumpet-shaped recess. Then, the turntable 1 is immediately index-rotated to the mold 2 at intervals of 0.5 seconds. The chunks were inserted one after another. The molten glass ingot in the mold 2 was rotated at a high speed while being kept in a substantially floating state by the jet gas, and was formed into a spherical glass molded body 3. In order to air-cool the glass molded body 3, 10 L / min of nitrogen gas was sprayed from the upper part of the mold 2 from the stage when the spheroidization was almost completed. At the same time, the flow rate of nitrogen gas flowing from the bottom of the concave portion of the mold 2 was increased to 3.0 L / min to promote cooling of the spherical glass molded body 3.

As shown in FIG. 1, the position where index rotation was performed 21 times from the insertion position (cast position) of the molten glass lump was taken as the glass molding removal position. On the other hand, as shown in FIG.
A container 9 filled with the liquid 6 was disposed at a position where the glass molded body 3 was blown away.

  As shown in FIG. 8, as soon as the molding die 2 arrives, a compressed air flow of 15 L / min is supplied from the gas injection device 4 provided obliquely above the glass molding die 2 at the take-out position of the glass molded body on the turntable. The spherical glass molded body 3 was blown off continuously by spraying toward the substantially trumpet-shaped recess. The glass molded body 3 blown off was dropped into the container 9 filled with the liquid 6 and accommodated.

  As described above, the glass molded body was taken out at intervals of 0.5 seconds, and continuous operation for 10 hours was performed to produce about 70000 28 mg spherical glass molded bodies. After completion of the continuous operation, the spherical glass molded body was pulled up from the liquid and dried to inspect the quality. The glass 6 was obtained by changing the liquid 6 in the container 9 to ethanol, hydrofluoroether, pure water heated to 50 ° C. and liquid nitrogen, respectively, but a spherical product having no problem in quality was obtained. It was.

  Like the glass molded body 3 obtained in the present example, a glass molded body of 30 mg or less has a small heat capacity, so that the cooling rate in the mold 2 is greatly increased. Therefore, the temperature of the glass molded body at the time of taking out can be surely lowered to 60 ° C. or less by sufficient air cooling in the mold 2, so that the bowl-shaped passage is rolled as in Example 2 shown below. No cooling promotion means was required.

Example 2 (Production Example of Glass Molded Body by Second Glass Molded Body Manufacturing Method)
The platinum alloy nozzle of Example 1 was removed, and a platinum alloy nozzle having an outer diameter of 3.7 mm was attached to the tip of a platinum outflow pipe connected to the bottom of the platinum crucible and temperature-controlled at 1000 ° C. The molten glass ingot was dropped at intervals of 0.5 seconds.

  The molten glass lump was spheroidized one after another in the same manner as in Example 1. As shown in FIG. 10, a bowl-shaped passage 8 having a recess 7 having a V-shaped cross section is disposed in advance at a position where the glass molded body 3 is blown away. The concave surface of the bowl-shaped passage 8 is formed of a heat-resistant resin, and the compressed air flow used for blowing the glass molded body is always in a state of blowing onto the passage. Further, as shown in FIG. 10, a container 9 filled with ethanol was disposed below the outlet of the glass molded body in the bowl-shaped passage 8. The bottom of the container 9 was cooled with a cooler or the like, and managed so that the liquid temperature did not rise.

As shown in FIG. 10, as soon as the molding die 2 arrives, the glass molding body is taken out from the gas injection device 4 provided obliquely above the glass molding die 2 at a flow rate of 15 L / min. The spherical glass molded body 3 was blown off continuously by spraying toward the concave portion.
The blown-off glass molded body 3 landed on the bowl-shaped passage 8 and slowly rolled in the inclined passage, and then dropped into a container 9 filled with ethanol and accommodated.

  As described above, the glass molded body was taken out at intervals of 0.5 seconds, and continuous operation for 10 hours was performed to produce about 70000 300 mg spherical glass molded bodies. After completion of the continuous operation, the spherical glass molded body was pulled up from ethanol and dried to inspect the quality. As a result, there was no broken glass molded body, and no defects such as surface scratches and foreign matter adhesion were observed.

  Moreover, when the glass molded body was produced by the same method as described above except that the liquid in the container 9 was changed to liquid nitrogen or low-boiling point hydrofluoroether (boiling point 76 ° C.), there was no problem as in the case of ethanol. A spherical glass molded body could be produced. However, in the case of using liquid nitrogen, dew condensation occurs on the surface of the glass molded body after pulling up, so the spherical glass molded body was rinsed with ethanol and then dried.

  Furthermore, when the glass molded body was produced by the same method as described above except that the liquid in the container 9 was changed to pure water at room temperature, the glass molded body was sometimes broken by about 12% by heat shock during liquid entry. It was. However, cracking could be prevented by heating pure water to 80 ° C. or higher. In addition, in order to avoid the surface modification of the glass in hot water, the glass molded object was taken out and dried every 30 minutes. As a result, a spherical glass molded body having no problem in quality was obtained.

Example 3 (Example of manufacturing a glass molded body by the third method for manufacturing a glass molded body)
In the same manner as in Example 1, 28 mg of molten glass was dropped from a platinum alloy nozzle at intervals of 0.5 seconds to obtain a molten glass lump, which was continuously molded on the mold in the same manner as in Example 1. went.

  The obtained glass molded body was taken out using the suction device 10 schematically shown in FIG. That is, first, the suction port 11 of the suction pipe 13 shown in FIG. 11 was placed 1 mm above the take-out position of the turntable shown in FIG. 1 and the other end of the suction pipe 13 was placed above the container 9. The suction pipe 13 and the inner surface of the container 9 are processed with Teflon (registered trademark) that is soft and heat resistant, and the suction pipe 13 has a spherical glass molded body that can move smoothly inside the pipe. Two 80 mm round arc-shaped bent portions were provided.

  As shown in FIG. 11, a vacuum generator was connected to the opening provided above the container 9, and the internal atmosphere of the suction pipe 13 connected to the container 9 and the container 9 was always exhausted to generate a negative pressure. The spherical glass molded body 3 on the mold 2 was sucked by the negative pressure, and the glass molded body 3 was sequentially discharged from the other end of the suction device 10 into the container 9. The negative pressure was adjusted and set within a range in which the glass molded body 3 was reliably sucked and the glass molded body 3 accommodated in the container 9 did not move to the vacuum generator side. A device for controlling the negative pressure as described above may be provided separately.

  By the above method, the glass molded body was continuously accommodated in the container 9 while replacing the container 9 for every 2000 glass molded bodies. The accommodated glass molded body was free from dirt and scratches and had good quality.

  Further, the same method as described above except that the suction port 11 of the suction device 10 is processed into a tapered hole shape (a shape in which the inner diameter increases toward the tip) and the suction port is brought close to a position of 1 mm from the upper surface of the mold. When the glass molded body was prepared and accommodated in the container 9, the accommodated glass molded body was free from dirt and scratches and had good quality.

  Further, the bottom of the container 9 shown in FIG. 11 is inclined from the right side to the left side of the figure (inclination angle 2 °), and the spherical glass molded body discharged into the container 9 is sequentially rolled to the left end of the container 9. Except for increasing the recovery efficiency, a glass molded body was produced by the same method as described above and stored in the container 9. As a result, the stored glass molded body was free from dirt and scratches and had good quality.

   On the other hand, when a glass molded body was prepared in the same manner as described above except that the container 9 was filled with ethanol and stored in the container 9, the stored glass molded body had good quality with no dirt or scratches. Was. In addition, although the ethanol vapor | steam generate | occur | produced in the container 9 is also attracted | sucked by the vacuum generator connected to the opening part of the container 9, the attracted ethanol vapor | steam was liquefied through the cooling pipe and was collect | recovered as ethanol.

Example 4 (Production Example of Glass Molded Body by Fourth Method for Manufacturing Glass Molded Body)
As shown in FIGS. 12 (a) and 12 (b), twelve molds 2 are arranged at equal intervals on the circumference around the rotation axis of the turntable 1, and the respective molds 2 are synchronized. The index rotation angle of the turntable 1 was adjusted so that it could be sequentially transferred to the corresponding stop position. One of the above stopping positions was allocated to the casting position, and the pipe outlet 12 was installed above the mold 2 that stopped at the casting position.

  While the turntable 1 is index-rotated, a molten glass lump is dropped from a pipe outlet 12 onto a mold 2 that remains at a predetermined casting position, and the molten glass lump is floated and rotated by a gas injected from below the mold 2 It was formed into a spherical shape.

  Next, the mold 2 to which the turntable 1 was rotated in the index and the molten glass block was supplied was unloaded from the cast position, and the empty mold 1 was loaded into the cast position. Such an operation was performed at a constant cycle by setting the separation interval of each molten glass ingot to 1.0 second and rotating the turntable 1 with an index.

  After the glass molded body 3 is cooled and not deformed even when an external force is applied for removal, the glass molded body 3 is shown in FIGS. 12B and 12C at a predetermined removal position shown in FIG. 30 L / min of dry nitrogen gas is injected from the gas injection device 4 along the inner wall of the recess of the mold 2 and the spherical glass molded body 3 in the recess is blown off along the inner wall facing the inner wall from which the gas has been injected. It was. A suction device 10 having a suction port 11 is disposed in advance at a position where the glass molded body 3 is blown away, a negative pressure is generated inside the suction device 10, and the blown glass molded body 3 is placed near the suction port 11. The liquid was sucked into the suction port 11 by negative pressure and transferred to the container 9 through a pipe connected to the suction port 11. Thus, the glass molded body 3 which has come to the take-out position one after another was blown off by the gas injection device 4, sucked by the suction device 10 and transferred to the container 9. In addition, in order not to damage the glass molded body 3, the tube in the suction device 10 was made of Teflon (registered trademark), and the container 9 was made of stainless steel.

  The separation interval of the molten glass ingots in this example was as short as 1.0 second as described above, but could be reliably taken out from each mold 2 without damaging the glass molded body 3.

Example 5 (Production Example of Optical Element)
A glass molded body 3 was produced in the same manner as in Example 4, and an optical element was manufactured using this glass molded body 3 as a precision press-molding preform.

  First, a raw material containing a glass component capable of obtaining desired optical characteristics is weighed, prepared, mixed well, introduced into a melting vessel, heated, melted, clarified, and homogenized to guide the molten glass with a pipe, It flowed out continuously from the pipe outlet 12 shown in FIG. 12, and was formed into a preform made of optical glass by the same method as in Example 3.

Next, each preform was washed and dried, and then a carbon film was coated on the entire surface, heated in a mixed gas atmosphere of nitrogen and hydrogen, and precision press-molded with a press mold to produce an aspheric lens. In this way, various optical elements such as aspherical lenses, spherical lenses, and microlens arrays were mass-produced.

  According to the present invention, it is possible to provide a method for producing a glass molded body in which the production speed of the glass molded body is increased and mass productivity is improved, and a method for producing an optical element from the glass molded body obtained by the method. Can do.

It is a figure which shows one example of the manufacturing apparatus of the glass forming body used by this invention. It is a figure which shows an example of the shaping | molding die used by this invention. It is a figure which shows one example of the preparation methods of a glass molded object. It is a figure which shows one example of the taking-out method of a glass molded object. It is a figure which shows one example of the taking-out method of a glass molded object. It is a figure which shows one example of the taking-out method of a glass molded object. It is a figure which shows one example of the taking-out method of a glass molded object. It is a figure which shows one example of the taking-out and accommodation method of a glass molded object. It is a figure which shows one example of the taking-out and accommodation method of a glass molded object. It is a figure which shows one example of the taking-out and accommodation method of a glass molded object. It is a figure which shows one example of the taking-out and accommodation method of a glass molded object. It is a figure which shows one example of the manufacturing method of a glass forming body. It is a figure which shows the platinum alloy nozzle used in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turntable 2 Mold 3 Glass molded body 4 Gas injection apparatus 5 Suction nozzle 6 Liquid 7 Concave part 8 Saddle-shaped passage 9 Container 10 Suction apparatus 11 Suction port 12 Pipe outlet

Claims (7)

A method for producing a glass molded body by molding a molten glass lump in a cooling process,
One after another beat drop a molten glass gob having a same mass from molten glass continuously flows out of the nozzle,
Circulating and using a plurality of molds that move synchronously to mold the molten glass lump to obtain a glass molded body of 30 mg or less ,
A method for producing a glass molded body comprising applying wind pressure to the obtained glass molded body and blowing the glass molded body out of a mold, and housing the blown molded body in a liquid. The glass melt gob while molding the glass shaped material of spherical, manufacturing method of a glass molded body according to claim 1, characterized in that blow from the mold by submerge the airflow on the lower side of the glass shaped material. A method for producing a glass molded body by molding a molten glass lump in a cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
Wind pressure is applied to the obtained glass molded body and blown off from the mold, the blown molded body is received by a bowl-shaped passage having a recess, cooled while moving in the depression, and the bowl-shaped passage is placed on a horizontal surface. In contrast, it is arranged so as to have an inclination angle, and by adjusting the inclination angle, the movement speed of the glass molded body moving through the bowl-shaped passage is adjusted, and the glass molded body is prevented from cracking due to heat shock. The manufacturing method of the glass forming body characterized. The manufacturing method of the glass forming body of Claim 3 which accommodates the said glass forming body cooled while moving the inside of the recessed part of a bowl-shaped channel | path in a liquid. A method for producing a glass molded body by molding a molten glass lump in a cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
A method for producing a glass molded body, comprising sucking and storing the obtained glass molded body. A method for producing a glass molded body by molding a molten glass lump in a cooling process,
Separate the molten glass lump of the same mass from the continuously flowing molten glass one after another,
Using a plurality of molds that move synchronously to form the molten glass lump to obtain a glass molded body,
A method for producing a glass molded body, comprising applying wind pressure to the obtained glass molded body and blowing the glass molded body out of a mold, and sucking and storing the blown molded body. The method for manufacturing an optical element manufactured method by Riga lath shaped body according to any one of claims 1 to 6, characterized in that the precision press-molding the resulting glass shaped body.

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