JP2014001086A - Glass gob molding device, method of manufacturing glass gob and method of manufacturing glass optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass gob molding device which is suitable for avoiding a decrease in manufacturing efficiency caused by the time required for press molding.SOLUTION: A glass gob molding device includes: a circulation path; a plurality of transfer tables 104A and others mounted with a glass mold 120Aa and others; a transfer control means which transfers each of the transfer table 104 and others on the circulation path; a plurality of switching connection paths switched and connected at a press position; a position control means which selectively arranges one of the switching connection paths at the press position, and makes the remaining switching connection paths retreat to a retreat position cut off from the circulation path; and a press means which press molds a molten glass gob on the glass mold 120Aa and others at the press position and at the retreat position. The transfer of the transfer table 104A and others to the press position starts simultaneously with the completion of the cast of the molten glass gob, and position control of the switching connection paths by the position control means and the transfer of the transfer table 104A and others by the transfer control means are performed so that the transfer table 104A and others transfer to the press position of which has started, is sent in to the press position substantially without waiting.

Description

  The present invention relates to a glass lump forming apparatus capable of forming a glass lump (glass gob or preform) for precision press molding from molten glass, a production method for producing a glass lump using the apparatus, and the method. The present invention relates to a manufacturing method for manufacturing a glass optical element by reheating and pressing a glass lump.

  2. Description of the Related Art A glass lump forming apparatus that forms a glass lump for precision press molding from molten glass flowing out from a molten glass supply unit is known. A specific configuration of this type of glass lump forming apparatus is described in Patent Document 1, for example.

  The glass lump forming apparatus described in Patent Document 1 receives a predetermined volume of molten glass lump from a molten glass supply unit by a glass mold and press-molds it between the glass mold and the upper mold. The glass lump obtained after press molding is carried out of the glass lump forming apparatus. That is, in the glass lump forming apparatus, the molten glass lump is cast into a glass mold, the cast molten glass lump is press-formed, and the glass lump after press molding is sequentially taken out.

JP 7-69653 A

  The glass lump forming apparatus described in Patent Document 1 temporarily stops the outflow of the molten glass by increasing the pressure in the forming chamber during the press forming of the molten glass lump, and the molten glass to the next glass mold Waiting for a cast of lumps. Therefore, the production efficiency is low, and the number of glass ingots that can be produced per unit time is small. Therefore, it is conceivable to cast the molten glass lump to the next glass mold during press molding. However, as exemplified in Patent Document 1, since this type of glass lump forming apparatus takes more time for press molding than casting, the next glass forming mold can be used even when casting of the molten glass lump is completed. Until the press molding is completed with the press mold, it is not possible to shift to the pressing process, and it is necessary to wait. Therefore, also in this case, the production efficiency is low in the end, and the number of glass lumps that can be produced per unit time cannot be increased so much. Moreover, since the time required for press molding increases as the capacity of the molten glass lump to be cast increases, and the standby time after casting the molten glass lump becomes longer, it is speculated that the production efficiency is significantly reduced.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a glass lump forming apparatus suitable for avoiding a decrease in production efficiency depending on time required for press forming. . Moreover, it is providing the manufacturing method of a glass lump, and the manufacturing method of a glass optical element.

  The glass lump forming apparatus according to one aspect of the present invention is an apparatus that takes time to press-mold the molten glass lump cast to the glass mold, rather than casting the molten glass lump to the glass mold, and the circulation path. A plurality of transfer stands mounted with glass molds, a transfer control means for sequentially and cyclically transferring each of the plurality of transfer stands to a cast position and a press position on the circulation path, and a plurality of switch units connected to be switched at the press position. A switching connection path, a position control means for selectively disposing one of the plurality of switching connection paths on the press position and retreating the remaining switching connection path on a retraction position cut from the circulation path, a press position, and Press means for press-molding the molten glass lump on the glass mold at the retreat position, and simultaneously with the completion of casting of the molten glass lump to the glass mold at the casting position The transfer control means starts the transfer of the transfer table to the press position, and the transfer table is transferred to the press position without waiting so that the transfer table is transferred to the press position. Before reaching the press position, the position control means controls the position of the plurality of switching connection paths, thereby placing the transfer stand at the press position where the press molding of the molten glass gob by the press means is completed, and the transfer control. The means is characterized in that the transfer table arranged at the press position is sent out toward the take-out position on the circulation path.

  According to one aspect of the present invention, after the molten glass lump has been cast, the transfer stage can be quickly transferred to the pressing process without waiting in the casting process, resulting in a decrease in production efficiency depending on the time required for press molding. Can be avoided. In addition, since the time required for press molding can be sufficiently secured without being affected by the casting time of the molten glass lump, the press means for performing press molding can be kept in contact with the molten glass lump for a long time. Heat can be taken away from the glass lump. Therefore, after separating the pressing means from the glass lump, it is possible to suppress deformation of the surface formed by the internal heat of the glass lump, and as a result, the glass lump can be formed with high molding accuracy. . Moreover, it is thought that the higher the production efficiency is obtained, the larger the capacity of the glass block to be formed (the longer the press forming takes).

  For example, the position control means returns the transfer table retracted to the retracted position to the press position at a timing until the press molding of the molten glass gob by the pressing means is completed. In this case, the transfer control means sends the transfer table toward the take-out position on the circulation path at the same time as the press molding is completed on the transfer table returned to the press position.

  The pressing means may be configured to be provided for each of the plurality of switching connection paths. In this case, the switching connection path is moved integrally with the corresponding press means to each position of the press position and the retracted position.

  A pair of glass molds may be mounted on the transfer table. In this case, the molten glass lump is sequentially cast with respect to the pair of glass molds at the casting position. The transfer control means starts the transfer of the transfer table to the press position at the same time as the casting of the molten glass block to the pair of glass molds at the cast position is completed.

  Moreover, the manufacturing method of the glass lump which concerns on one form of this invention is a method of shape | molding a glass lump using said glass lump shaping | molding apparatus, the process of casting a molten glass lump with respect to a glass shaping | molding die, and glass A step of press-molding the molten glass ingot cast into the mold, and at the same time as the casting of the molten glass ingot to the glass mold at the casting position is completed, the transfer of the transfer table to the press position is started, and the press By controlling the positions of a plurality of switching connection paths before the transfer table reaches the press position so that the transfer table that has started transfer to the position can be transferred to the press position without waiting. The transfer stand that completes the press molding of the molten glass gob by the pressing means is arranged at the press position, and the transfer stand arranged at the press position is sent toward the take-out position on the circulation path. That.

  Moreover, the manufacturing method of the glass optical element which concerns on one form of this invention was introduce | transduced into the predetermined press-molding die, the process of introducing the glass lump manufactured using said manufacturing method into a predetermined press-molding die The method includes a step of precision press molding in a state where the glass lump is softened, and a step of taking out the precision press-molded glass optical element from the press mold.

  Moreover, the manufacturing method of the glass optical element which concerns on one form of this invention was introduce | transduced into the predetermined press-molding die, the process of introducing the glass lump manufactured using said manufacturing method into a predetermined press-molding die A glass optical element having a final shape is formed by press-molding a glass lump in a softened state to form an intermediate having a shape that approximates a predetermined final shape, and at least polishing the formed intermediate. Obtaining.

  According to the glass lump forming apparatus according to one aspect of the present invention, a glass lump forming apparatus suitable for avoiding a decrease in production efficiency depending on the time required for press forming is provided. Further, a glass lump manufacturing method capable of avoiding a decrease in production efficiency depending on the time required for press molding, and a glass optical element with high accuracy can be manufactured using the glass lump manufactured by the method. A manufacturing method is provided.

It is a figure showing the whole glass lump forming device composition concerning an embodiment of the present invention. It is the upper side figure and sectional drawing of the transfer stand arrange | positioned on the circulation path of the glass lump shaping | molding apparatus which concerns on embodiment of this invention. It is an explanatory assistance figure which assists description of the manufacturing method of the glass lump for precision press molding by the glass lump shaping | molding apparatus which concerns on embodiment of this invention. It is a figure which shows the timing chart of manufacture of the glass lump in each transfer stand which concerns on embodiment of this invention. It is a schematic diagram explaining arrangement | positioning of each transfer stand in the casting process and press process of embodiment of this invention.

  Hereinafter, a glass lump forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an overall configuration of a glass lump forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the glass lump forming apparatus 1 includes an annular circulation path 102, a plurality of transfer tables 104 (three in this embodiment), a molten glass supply unit 106, an upper mold 108 for pressing, and a heating furnace 110. (110a, 110b), a controller 112, a slide table 114, a table driving mechanism 116, and a take-out means 118.

  2A and 2B are a top view and a cross-sectional view of the transfer table 104 disposed on the circulation path 102, respectively. As shown in FIG. 2, the circulation path 102 has a configuration in which two types of rails having different widths are stacked, and includes a main guide rail 102a on the lower side and a rack rail 102b on the upper side.

  The transfer table 104 includes a carriage plate 104a on which a pair of glass molds 120 are mounted. Two pairs of wheels 104b incorporating a bearing and one pinion 104c are attached to the lower surface side of the carriage plate 104a. The carriage plate 104a is connected to the main guide rail 102a through two pairs of wheels 104b so as to be able to travel. The pinion 104c is meshed with the side surface (rack) of the rack rail 102b. The controller 112 can independently drive and control the pinion drive unit 104 d installed on the transfer table 104 for each transfer table 104.

  When the pinion 104c rotates under the control of the pinion drive unit 104d by the controller 112, the rotational force is converted into a motion along the rack rail 102b. Following this movement, each of the two pairs of wheels 104b rolls on the side surface of the main guide rail 102a, so that the carriage plate 104a (transfer table 104) travels on the circulation path 102. A traveling system of the carriage plate 104a on the circulation path 102 using the wheels 104b can be constructed by using, for example, an “ASK rolling guide system” (registered trademark) manufactured by ASK. For the sake of clarity, the connection between the controller 112 and the pinion drive unit 104d of each transfer table 104 is omitted.

[Manufacture of glass lump]
FIG. 3A and FIG. 3B are explanatory auxiliary diagrams for assisting in the description of the method for producing a glass lump for precision press molding by the glass lump forming apparatus 1. FIG. 3A is an explanatory auxiliary diagram of the casting process, and FIG. 3B is an explanatory auxiliary diagram of the pressing process. The transfer table 104 is circulated and transferred in the clockwise direction in the circulation path 102 as indicated by an arrow in FIG.

<Casting process>
In manufacturing the glass lump, the transfer table 104 is transferred to the cast position Pc on the circulation path 102. More specifically, the transfer table 104 is transferred such that the glass mold 120 (reference numeral 120A) on the downstream (right) side of the pair of glass molds stops at the cast position Pc. An outflow nozzle 106a at the tip of the molten glass supply unit 106 is disposed immediately above the glass mold 120 stopped at the casting position Pc. Here, the upper part of the molten glass supply unit 106 communicates with a stirring tank, a clarification tank, and a glass melting tank, which are not shown. As a result, molten, clarified, and homogenized molten glass is continuously supplied to the molten glass supply unit 106. From the outflow nozzle 106a, the clarified and homogenized molten glass continuously flows out at a constant speed.

  An elevator 122 that moves the glass mold 120 in the vertical direction is installed below the glass mold 120 that remains at the casting position Pc. The elevator 122 includes a push-up shaft body 122a that pushes up the sliding shaft body 120a that supports the glass mold 120 from the lower surface, and a lift motor (not shown) that moves the push-up shaft body 122a up and down in the vertical direction. When the glass mold 120 is transferred to the casting position Pc, the elevator 122 raises the push-up shaft body 122a and pushes up the sliding shaft body 120a, thereby raising the glass mold 120 to a position close to the outflow nozzle 106a. .

  The elevator 122 receives the tip of the molten glass flow that the glass forming mold 120 raised to the position close to the outflow nozzle 106a flows out of the outflow nozzle 106a, and pushes the shaft 122a up at a timing when the molten glass flow reaches a predetermined capacity. Make a sudden drop. As a result, the glass mold 120 (and the sliding shaft 120a) descends at a speed faster than the outflow speed of the molten glass flow, and a predetermined volume of the molten glass lump is separated from the molten glass flow (down cutting method). . The method for casting the molten glass lump onto the glass mold 120 is not limited to the descent cutting method described here, but may be another method such as a method of dropping the molten glass lump with its own weight from the outflow nozzle 106a (drop cutting method). The method may be adopted.

  Next, the transfer table 104 is transferred by a predetermined distance so that the upstream (left) glass mold 120 (reference numeral 120B) of the pair of glass molds stops at the cast position Pc. The time required for this predetermined distance transfer is, for example, 0.4 s. Similarly, a predetermined volume of molten glass ingot is cast to the upstream glass forming die 120B. In this way, a predetermined volume of molten glass lump is cast one after another to each glass mold 120 of the transfer table 104 that is sequentially transferred to the cast position Pc.

  Note that gas (for example, air or nitrogen) supplied from a gas supply unit (not shown) is ejected from the glass mold 120. Therefore, the molten glass lump floats from the glass mold 120 due to the gas jet pressure during the manufacturing process, and the occurrence of molding defects due to contact with the glass mold 120 is suppressed.

<Pressing process>
The transfer table 104 is transferred to the press position Pp on the circulation path 102 at the same time as the casting of the molten glass block with respect to the pair of glass molds 120 is completed. The time required for the transfer stage 104 to be transferred from the cast position Pc to the press position Pp is, for example, 1.2 s (the time required to replace the glass mold at the cast position Pc with the next glass mold = 0.4 s, The time required for the transfer table 104 sent from the cast position Pc to reach the press position Pp with the replacement of the glass mold is 0.8 s). An upper die for pressing 108 is installed immediately above each glass forming die 120 of the transfer table 104 transferred to the press position Pp. The molten glass lump in each glass forming die 120 is press-formed into a predetermined shape between the glass forming die 120 and the upper die 108 for pressing. At this time, since each molten glass lump has a different elapsed time after being cast into the glass mold 120, the glass glass mold 120 </ b> A that is first on the downstream side is equalized so that the elapsed time after the casting is equalized. Then, press molding is started with the upper mold 108 for pressing one of the molten glass ingots, and then the elapsed time after casting becomes equal to the molten glass ingot in the downstream glass forming die 120A. Press molding with the other upper mold 108 for press is performed on the molten glass ingot in the glass mold 120B. By varying the timing of press molding in this way, it is possible to mold the molten glass ingots cast in the two glass molds with the same accuracy.

<Takeout process>
The transfer table 104 is sent out from the press position Pp when the press molding of the molten glass ingots in the pair of glass forming dies 120 is completed. The transfer table 104 sent out from the press position Pp is transferred through a tunnel-shaped heating furnace 110 a installed so as to cover a part of the circulation path 102. The glass lump in each glass mold 120 of the transfer table 104 is gradually cooled in the heating furnace 110a managed with a predetermined temperature profile. Next, the glass block is transferred to the take-out position Pt on the circulation path 102 while being sufficiently cooled in the heating furnace 110a. At the take-out position Pt, two glass lumps in each glass forming die 120 are simultaneously blown off by a blow-out gas from the take-out means 118 to a glass lumps recovery unit (not shown). The glass lump that has been blown away is collected by the glass lump collection unit without causing scratches due to contact with each other. The transfer table 104 is transferred to the heating furnace 110b after the glass lump is taken out. In the heating furnace 110b, the temperature of the glass mold 120 is adjusted to a temperature suitable for forming a glass lump. Thus, in each glass forming die 120, casting of the molten glass lump, press forming of the molten glass lump, cooling of the glass lump, and take-out of the glass lump are sequentially performed. Each glass mold 120 is returned to the casting step after temperature adjustment by the heating furnace 110b, and is used in a circulating manner. When the glass lump to be molded has a large capacity and the glass lump transferred to the takeout position Pt is not sufficiently cooled, the glass lump formed in the downstream glass forming mold 120A is first taken out, Next, the glass lump formed in the upstream glass forming mold 120B may be taken out. Further, the take-out position Pt may be shifted to the left side (more downstream side) in FIG. 1 in order to ensure sufficient time for cooling the two glass blocks. Moreover, since it becomes difficult to blow off by blowing gas, so that the capacity | capacitance (weight) of the glass lump to shape | mold is large, you may take out glass lump from each glass shaping | molding die with a suction pad instead of blowing gas.

[Manufacture of glass optical elements]
The glass block formed by the glass block forming apparatus 1 is introduced into a press forming die (not shown) having a forming surface, heated and softened together with the press forming die, and precision press-molded in the softened state and then pressed. The surface shape of the molding surface is transferred to a softened glass lump. Next, the glass lump introduced into the press mold is cooled in a state where the glass lump is pressed in the press mold, or in a state where the molding surface is in contact with the glass lump, and is reduced to a predetermined temperature (for example, a glass transition temperature) or less. Then, it is taken out from the press mold. Thereby, the glass optical element (for example, aspherical lens) to which the molding surface shape was transferred is obtained. The aspherical lens manufactured in this way is subjected to various grinding / polishing processes such as centering and chamfering processes, and various coatings such as dyeing processes, antireflection films, and UV cuts, if necessary. Thus, a glass optical element is obtained. In addition to the above-described embodiment in which a glass lump is introduced into a mold and heated and softened together with the press mold, the glass lump is heated in advance and introduced into the mold in a softened state, followed by precision press molding. You can also.

[Specific timing chart of glass lump production]
By the way, according to the conventional technical common sense, since the press molding of the molten glass lump is a process that takes more time than casting, also in this embodiment, after the casting of the molten glass lump to the glass mold 120 is completed, the transfer table 104 Seems to be unable to be transferred to the press process immediately. However, the glass lump forming apparatus 1 of the present embodiment operates as described below to transfer the transfer table 104 to the press position Pp at the same time as the casting of the molten glass lump to the glass mold 120 is completed. Can do. That is, in the present embodiment, the waiting time of the transfer table 104 after casting the molten glass lump can be substantially eliminated regardless of the time required for press forming, and the reduction in production efficiency depending on the time required for press forming is avoided. It is done. In addition, since the time required for press molding can be sufficiently secured without being affected by the casting time of the molten glass lump, the upper mold 108 for pressing can be kept in contact with the molten glass lump for a long time. You can take enough heat from the mass. Therefore, after the upper mold 108 for press is released from the glass lump, it is possible to suppress the deformation of the surface formed by the internal heat of the glass lump. As a result, the glass lump is formed with high molding accuracy. can do. Moreover, it is thought that the higher the production efficiency is obtained, the larger the capacity of the glass block to be formed (the longer the press forming takes).

  FIG. 4 is a diagram showing a timing chart for manufacturing a glass lump on each transfer table 104. FIG. 5 is a schematic diagram for explaining the arrangement of the transfer tables 104 in the casting process and the pressing process. 4 and 5, the three transfer tables 104 are denoted by reference numerals 104A, 104B, and 104C for convenience of explanation. Also, reference numerals 120Aa and 120Ba are attached to the downstream and upstream glass molds of the transfer table 104A, respectively, and reference numerals 120Ab and 120Bb are attached to the downstream and upstream glass molds of the transfer table 104B, respectively. Reference numerals 120Ac and 120Bc are assigned to the glass molds on the downstream side and the upstream side of the transfer table 104C, respectively.

  As shown in FIG. 4, the transfer table 104A is transferred from a predetermined position on the circulation path 102 and stops at a position (cast position Pc) where the glass forming mold 120Aa comes directly under the outflow nozzle 106a (FIG. 5 ( a)). Next, the molten glass lump is cast on the glass mold 120Aa transferred to the casting position Pc. After the casting table 104A is cast to the glass mold 120Aa, the transfer table 104A is transferred to and stopped at a position (cast position Pc) where the glass mold 120Ab comes directly under the outflow nozzle 106a. Similarly to the glass mold 120Aa, the molten glass lump is cast on the glass mold 120Ab. In this embodiment, the time taken to cast the molten glass gob to each glass mold 120 is 8.0 s, and the time taken to replace the glass mold at the cast position Pc (glass molding inserted at the cast position Pc) The time required for the mold to change from the glass forming mold 120A to 120B of the same transfer stand and the time required to change from the glass forming mold 120B to the next transfer stand 120A) is 0.4 s.

  A slide table 114 is installed at a position subsequent to the cast position Pc. A plurality of (two in the present embodiment) switching connection paths 132 and 134 arranged in parallel are laid on the slide table 114. The slide table 114 can slide in the arrow X1 direction or the arrow X2 direction according to the drive control of the table drive mechanism 116 by the controller 112. When the slide table 114 slides in the arrow X1 direction or the arrow X2 direction, one of the switching connection paths 132 and 134 is inserted into the press position Pp on the circulation path 102 and the other is cut off from the circulation path 102. Retreated to position Pe. In FIG. 1, the retracted position Pe is inside the circulation path 102 and indicates the retracted position of the switching connection path 134. The retraction position Pe of the switching connection path 132 is outside the circulation path 102, but is not shown here.

  Initially, the switching connection path 132 is inserted at the press position Pp, and the transfer table 104 is not disposed on any of the switching connection paths 132 and 134. Therefore, the transfer table 104A starts to be transferred to the press position Pp at the same time as the casting of the molten glass lump to the glass mold 120Ba is completed. As described above, for example, after 1.2 s, the press position Pp (switch connection path 132) To reach and stop. The transfer table 104B is moved from a predetermined position on the circulation path 102 at the same time when the transfer table 104A starts to be transferred to the press position Pp, and the glass mold 120Ab is located immediately below the outflow nozzle 106a (cast position Pc). ) (See FIG. 5B). As described above, the time taken at this time is 0.4 s taken to replace the glass mold at the cast position Pc.

  Above the switching connection path 132, a pair of upper molds for pressing 108 that move integrally with the switching connection path 132 is installed. When the transfer platform 104A stops at the press position Pp (switching connection path 132), one of the pair of upper press molds 108 installed above the switching connection path 132 descends, and the molten glass lump in the glass forming mold 120Aa. Press. Further, the other upper mold 108 for pressing is lowered at a predetermined time difference, and the molten glass lump in the glass forming mold 120Ba is pressed. In the present embodiment, when the time required for press molding by the glass mold 120 and the upper mold 108 for press is 10.0 s, the above-mentioned predetermined time difference in the present embodiment is to the molten glass lump in the glass mold 120Aa. 8.4 s after the start of the press.

  On the other hand, in the transfer table 104B, the molten glass lump is cast on the glass forming mold 120Ab transferred to the cast position Pc. After the casting table 104B is cast to the glass mold 120Ab, the transfer stage 104B is transported and stopped at a position (cast position Pc) where the glass mold 120Bb comes directly under the outflow nozzle 106a. Similarly to the glass mold 120Ab, the molten glass lump is cast on the glass mold 120Bb. The transfer table 104B starts to be transferred to the press position Pp at the same time as the casting of the molten glass block with respect to the glass mold 120Bb is completed.

  However, at this timing, the press molding process for the molten glass in the glass mold 120Ba is not yet completed in the transfer table 104A (the press molding with the glass mold 120Aa has been completed). Therefore, the slide table 114 is between the time when the transfer table 104A is stopped at the press position Pp (switching connection path 132) and the time when the casting of the molten glass block with respect to the glass molds 120Ab and Bb is completed at the transfer table 104B. Slide in the direction of arrow X1. As a result, the switching connection path 132 where the transfer table 104A is arranged is retracted to the retreat position Pe, and the switching connection path 134 where no transfer table 104 is arranged is inserted into the press position Pp (FIG. 5 (c)). Therefore, the transfer table 104B is transferred to the press position Pp (switching connection path 134) and stopped without substantially waiting after casting of the molten glass lump (see FIG. 5D). Since the slide speed of the slide table 114 is low, even if the glass forming mold 120 is moved or stopped during the press molding process or during the float forming of the molten glass lump, the inertial force or vibration acting on the molten glass lump. There is no possibility that the accuracy of the glass lump is lowered due to the influence of the above.

  In addition to the pair of upper press molds 108 provided above the switching connection path 132, a pair of upper press molds 108 that move integrally with the switching connection path 134 are also installed above the switching connection path 134. Has been. When the transfer platform 104B stops at the press position Pp (switching connection path 134), one of the pair of upper press molds 108 installed above the switching connection path 134 descends, and the molten glass lump in the glass forming mold 120Ab Press. Further, the other upper mold 108 for pressing is lowered at a predetermined time difference, and the molten glass lump in the glass mold 120Bb is pressed. The predetermined time difference is 8.4 seconds after the start of pressing the molten glass ingot in the glass mold 120Ab as described above.

  The slide table 114 can transfer the transfer table 104A to the annular circulation path 102 at the timing when the press forming process for the molten glass in the glass forming mold 120Ba is completed at the transfer table 104A retracted to the retracted position Pe. By the time the press molding process for the molten glass ingot in the glass mold 120Ba is completed, the glass slides in the direction of the arrow X2 and stops at the press position Pp. That is, the transfer stand 104A is inserted at the press position Pp before the press molding process is completed on the switching connection path 132 (during the press molding process), and the press molding is also performed at the retreat position Pe on the switching connection path 134. The transfer table 104B being processed is inserted (see FIG. 5E). At this time, the molten glass lump in the glass forming mold 120Bb of the transfer table 104B is in a state before press forming.

  After returning to the press position Pp, the transfer platform 104A on the switch connection path 132 is sent out from the press position Pp (switch connection path 132) at the same time as the press molding process for the molten glass ingot in the glass mold 120Ba is completed. . The transfer table 104A delivered from the press position Pp is sequentially transferred through the heating furnace 110a, the take-out position Pt, and the heating furnace 110b, and is returned to a predetermined position before the cast position Pc for circulation (see FIG. 5F). ). In FIG. 4, for the sake of convenience, the timing chart for the transfer table 104A (also for the transfer tables 104B and 104C) after being returned to the predetermined position is omitted.

  Further, the transfer table 104C is transferred from a predetermined position on the circulation path 102 at the same time when the transfer table 104B is started to be transferred to the press position Pp (switching connection path 134), and the glass forming mold 120Ac is directly below the outflow nozzle 106a. It stops at the coming position (cast position Pc) (see FIG. 5D). Next, the molten glass lump is cast on the glass mold 120Ac transferred to the casting position Pc. After the molten glass lump is cast onto the glass mold 120Ac, the transfer table 104C is transferred to and stopped at a position (cast position Pc) where the glass mold 120Bc is directly below the outflow nozzle 106a. Similarly to the glass mold 120Ac, the molten glass lump is cast on the glass mold 120Bc. The transfer table 104C starts to be transferred to the press position Pp at the same time as the casting of the molten glass block with respect to the glass mold 120Bc is completed. At this time, at the press position Pp (switching connection path 132), the transfer table 104A has already been sent out (see FIG. 5F). Therefore, the transfer table 104C is transferred to the press position Pp (switching connection path 132) and stopped (see FIG. 5G). When the transfer table 104C stops at the press position Pp (switching connection path 132), one of the pair of upper press molds 108 installed above the switching connection path 132 descends, and the molten glass lump in the glass forming mold 120Ac. Press. Further, the other upper mold 108 for pressing is lowered at the predetermined time difference described above, and the molten glass lump in the glass forming mold 120Bc is pressed.

  The slide table 114 can transfer the transfer table 104B to the annular circulation path 102 at the timing when the press molding process for the molten glass in the glass forming mold 120Bb is completed at the transfer table 104B retracted to the retracted position Pe. By the time the press molding process for the molten glass ingot in the glass mold 120Bb is completed, the glass sheet is slid in the direction of the arrow X1 and stopped at the press position Pp. That is, the transfer stand 104B is inserted into the press position Pp before the press molding process is completed on the switching connection path 134 (during the press molding process), and press molding is also performed on the switching connection path 132 at the retracted position Pe. The transfer table 104C being processed is inserted (see FIG. 5 (h)). At this time, the molten glass lump in the glass forming mold 120Bc of the transfer table 104C is in a state before press forming.

  After the transfer table 104B on the switching connection path 134 is returned to the press position Pp, the press molding process for the molten glass ingot in the glass mold 120Bb is completed, and at the same time, the transfer stage 104B is sent from the press position Pp (switch connection path 134). It is transferred on the circular circulation path 102. The transfer table 104B delivered from the press position Pp is sequentially transferred through the heating furnace 110a, the take-out position Pt, and the heating furnace 110b, and returned to a predetermined position before the cast position Pc for circulation (see FIG. 5 (i)). ).

  The transfer table 104C on the switching connection path 132 is also in the glass mold 120Bc so that the transfer table 104C can be transferred to the annular circulation path 102 at the timing when the press molding process for the molten glass in the glass mold 120Bc is completed. Is returned to the press position Pp by the time the press molding process for the molten glass ingot is completed (not shown in FIGS. 4 and 5, but at this time, the switching connection path 134 has a transfer platform 104A during the press molding process. ), The transfer table 104C is sent out from the press position Pp at the same time as the press molding process for the molten glass ingot in the glass mold 120Bc is completed, and the heating furnace 110a, the takeout position Pt, and the heating furnace 110b are sequentially transferred and circulated. For use, it is returned to a predetermined position before the cast position Pc.

  As described above, when a glass lump is manufactured using the glass lump forming apparatus 1 of the present embodiment, it can be quickly transferred to the pressing step without waiting the transfer table 104 after casting the molten glass lump. A decrease in production efficiency depending on the time required for press molding can be avoided. In addition, since the time required for press molding can be sufficiently secured without being affected by the casting time of the molten glass lump, the upper mold 108 for pressing can be kept in contact with the molten glass lump for a long time. You can take enough heat from the mass. Therefore, after the upper mold 108 for press is released from the glass lump, it is possible to suppress the deformation of the surface formed by the internal heat of the glass lump. As a result, the glass lump is formed with high molding accuracy. can do. Moreover, it is thought that the higher the production efficiency is obtained, the larger the capacity of the glass block to be formed (the longer the press forming takes).

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present application also includes an embodiment that is exemplarily specified in the specification or a combination of obvious embodiments and the like as appropriate.

  For example, in the above, the three transfer stands 104 are illustrated, but in another embodiment, two or four or more may be used. In the above, two switching connection paths are illustrated, but in another embodiment, three or more may be used. The number of transfer tables 104, the number of switching connection paths, and the number of glass molds installed on each transfer table 104 are appropriately set according to the capacity of the glass block to be manufactured, the production quantity per unit time, and the like. For example, each transfer table 104 may be configured to include one glass mold. In this case, after casting the molten glass lump to one glass mold, the transfer table 104 can be transferred to the pressing process without taking time, so the molten glass lump in the cast state is immediately pressed. It is advantageous for molding.

  Moreover, in the above, although the manufacturing method of the preform for precision press molding by the glass lump molding apparatus 1 and the precision press molding using the preform shape | molded by the manufacturing method were demonstrated, this invention is limited to this. It is not a thing but a glass blank can also be shape | molded as a glass lump. The glass ball is roughened by various known polishing methods such as barrel polishing and glass optical elements are formed by reheat press molding, and various known roughening methods such as smoothing and CG (curve generator) processing are used. By performing polishing and fine polishing, it can be processed into an optical element such as a spherical lens. In addition, glass gob or preform is reheat press molded after barrel polishing (or without barrel polishing depending on the glass material), and CG polishing is performed on an intermediate body having a shape approximate to the final shape obtained by reheat press molding. A method of obtaining a glass optical element having a final shape by performing polishing such as processing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Glass lump forming apparatus 102 Circulation path 102a Main guide rail 102b Rack rail 104 (104A, 104B, 104C) Transfer stand 104a Carriage plate 104b Wheel 104c Pinion 104d Pinion drive part 106 Molten glass supply part 106a Outflow nozzle 108 Upper mold 110 for press (110a, 110b) Heating furnace 112 Controller 114 Slide table 116 Table drive mechanism 118 Takeout means 120 (120A, 120B) Glass forming mold 120a Sliding shaft body 122 Lifting machine 122a Pushing shaft body 132, 134 Switching connection path

Claims (7)

It is a glass lump molding apparatus for molding a glass lump that takes time to press-mold a molten glass lump cast on the glass mold, rather than casting a molten glass lump against a glass mold,
The circuit,
A plurality of transfer stands equipped with the glass mold,
Transfer control means for transferring each of the plurality of transfer tables sequentially and cyclically to a cast position and a press position on the circulation path;
A plurality of switching connection paths switched and connected at the press position;
Position control means for selectively disposing one of the plurality of switching connection paths on the press position and retracting the remaining switching connection paths on a retracted position cut from the circulation path;
Press means for press-molding a molten glass lump on the glass mold at the press position and the retracted position;
With
At the same time as the casting of the molten glass block to the glass mold at the casting position is completed, the transfer control means starts transferring the transfer table to the press position,
Before the transfer table reaches the press position so that the transfer table that has been transferred to the press position is fed to the press position without waiting,
By controlling the positions of the plurality of switching connection paths by the position control means, a transfer stand for completing the press molding of the molten glass gob by the press means is disposed at the press position, and the transfer control means The glass lump forming apparatus is characterized in that a transfer table arranged at the press position is sent out toward a take-out position on the circulation path. The position control means includes
The transfer table retracted to the retracted position is returned to the press position at the timing until the press molding of the molten glass gob by the pressing means is completed,
The transfer control means includes
The glass lump forming apparatus according to claim 1, wherein simultaneously with completion of the press molding by the transfer table returned to the press position, the transfer table is sent toward a take-out position on the circulation path. The pressing means is provided for each of the plurality of switching connection paths;
The switching connection path is
The glass lump forming apparatus according to claim 1 or 2, wherein the glass lump forming apparatus is moved integrally with the corresponding pressing means at each of the pressing position and the retracted position. The transfer table is mounted with a pair of glass molds,
At the casting position, a molten glass lump is sequentially cast with respect to the pair of glass molds,
The transfer control means includes
4. The transfer of the transfer table to the press position is started simultaneously with the completion of casting of the molten glass gob to the pair of glass molds at the cast position. The glass lump forming device according to one item. A glass lump manufacturing method for forming a glass lump using the glass lump forming apparatus according to any one of claims 1 to 4,
A step of casting a molten glass lump to the glass mold,
A step of press-molding a molten glass lump cast in the glass mold,
Including
At the same time as the casting of the molten glass lump to the glass mold at the casting position is completed, the transfer of the transfer table to the press position is started,
Before the transfer table reaches the press position so that the transfer table that has been transferred to the press position is fed to the press position without waiting,
A transfer stand that completes press forming of the molten glass gob by the press means is arranged at the press position by controlling the positions of the plurality of switching connection paths, and the transfer stand arranged at the press position is circulated in the circulation. A method for producing a glass lump that is sent out toward a take-out position on the road. Introducing a glass lump produced using the production method according to claim 5 into a predetermined press mold;
A step of precision press molding in a softened state of the glass lump introduced into the predetermined press mold,
Taking out the precision press-molded glass optical element from the press mold; and
The manufacturing method of the glass optical element containing this. Introducing a glass lump produced using the production method according to claim 5 into a predetermined press mold;
Press-molding the glass lump introduced into the predetermined press-molding mold in a softened state, and forming an intermediate body having a shape approximating a predetermined final shape;
Obtaining a glass optical element having the final shape by at least polishing the formed intermediate; and
The manufacturing method of the glass optical element containing this.

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