JP2007131489A - Apparatus for molding glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for molding glass, which is capable of efficiently, rapidly and uniformly heating a mold. <P>SOLUTION: In the apparatus for molding glass, the inside of a molding chamber 8 is filled with an inert gas, and then after filling an IN port load lock chamber 12 with the inert gas, a mold set 15 provided in the IN port load lock chamber 12 is taken into the chamber 8 from the IN port load lock chamber 12 by using an IN port table 9. The mold set 15 is heated to 640°C by heat transfer from a sheathed heater 1a and radiant heat from an infrared lamp heater 22 in a heating zone, and a glass workpiece in the mold set 15 is pressed and molded in a press zone. At that time, a temperature is kept by a sheathed heater 2a of a plate 2 and a sheathed heater 5a of a plate 5 in the press zone. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a glass molding apparatus that heats and softens an optical glass material such as an aspheric glass lens represented by a digital camera or the like and press-molds it.

  In a glass forming apparatus, a mold set is heated, press-formed, cooled and sequentially conveyed to each process area to form a desired glass element.

  In the heating process in this glass forming apparatus, the mold set and the glass material are heated by sandwiching the mold set with heating plates arranged in the vertical direction of the mold set (for example, Patent Document 1).

  However, the conventional heating apparatus has the following problems by bringing the heated plate into contact with the mold set.

1. Since the mold and the glass material are heated by heat transfer from the heating plate through the upper and lower surfaces of the mold, the heating efficiency is poor and the time required for heating is required.

2. Since heat is transferred from the upper and lower surfaces of the mold, the upper and lower temperatures of the mold are high, and the temperature at the center of the mold is low. It was not secured.

3. Since the heating method is inefficient, in the case of a molded product having a relatively large size (for example, a diameter of 40 mm or more), there is a case where it cannot be molded due to insufficient heating.

4). Since the upper and lower molds are fitted to the body mold on the sleeve, if the heating plate is pressed from the top when the glass material is not sufficiently softened, the mold molding surface may be damaged or the glass material may be broken. It was.

5. Since the temperature adjustment is performed via a heating plate, it is difficult to adjust the temperature of the mold set.

6). In the case of the conventional heating plate, since the rate of temperature rise is slow and the response is poor, it is necessary to keep heating during idling of the apparatus, which is disadvantageous for energy saving.

Some furnaces are heated in a non-contact manner, but since the entire furnace is heated, the thermal efficiency is poor. Furthermore, since there is no cooling process, the temperature of the mold is not sufficiently lowered when it is taken out from the furnace, the mold may be oxidized and deteriorated, and an additional cooling time is required (for example, patents). Reference 2).
Japanese Patent Laid-Open No. 62-292629 JP-A-5-339018

  As described above, there is a problem in that the efficiency of heating the mold set is poor, the heating rate is slow, and the glass material is not heated uniformly.

  An object of the present invention is to provide a glass molding apparatus capable of efficiently heating a mold and heating uniformly at a high speed.

  The glass molding apparatus of the present invention is a glass molding apparatus for molding a mold set in which a glass material is placed between an upper mold and a lower mold by heating and pressurizing the mold, in which the glass material is placed. It is moved to the vicinity surrounding the set and includes heating means for heating in a non-contact manner.

  The glass forming apparatus of the present invention can realize heating with high power saving and high accuracy, and stably and highly accurately form a large lens or a complicated lens having a difficult shape. Therefore, it is possible to reduce the damage of the mold as compared with the conventional case.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a glass forming apparatus for forming an optical glass element according to the present invention. That is, the glass forming apparatus includes a forming chamber 8, an IN port load lock chamber (replacement chamber) 12, an OUT port load lock chamber (replacement chamber) 13, a vacuum pump 30, and a nitrogen gas supply unit 40. . In this embodiment, nitrogen gas is used as an inert gas.

  Inside the molding chamber 8 are a plate 1 and an infrared lamp heater unit 4 that form a heating zone, plates 2 and 5 that form a press zone, plates 3 and 6 that form a cooling zone, and an IN port table that forms an intake zone. 9 and an OUT port table 10 forming a take-out zone.

  The plate 1 provided in the heating zone incorporates a heating sheath heater 1a, and the infrared lamp heater unit 4 includes three infrared lamp heaters 22 processed into an arc shape, which will be described in detail later. Further, the infrared lamp heater unit 4 is provided with an air cylinder 7a in the upper part, and is configured to be movable up and down. The infrared lamp heater unit 4 is lowered and the mold set 15 placed on the plate 1 is heated in a non-contact manner. At this time, the mold set 15 is adjusted to a desired temperature by a thermocouple (not shown) provided on the plate 1 and the infrared lamp heater unit 4 and a control device (not shown).

  In this heating zone, the glass material inserted into the mold set 15 is heated until it has a desired viscosity capable of being press-molded in the subsequent press zone.

  The plate 5 provided in the press zone is provided with an air cylinder 7b in the upper part and is configured to be movable up and down. The pressing process is performed by lowering the plate 5 and pressurizing the mold set 15 placed on the plate 2. The plates 2 and 5 are provided with sheath heaters 2a and 5a and a thermocouple (not shown), respectively, and are adjusted to a desired temperature by a control device (not shown).

  The press zone presses the mold set 15 by the air cylinder 7b while keeping the heated mold set 15 and the glass material at a desired temperature, thereby pressing and deforming the glass material to obtain a desired surface shape. To form.

  In the cooling zone, plates 3 and 6 are provided. The plate 6 is provided with an air cylinder 7c in an upper portion thereof and can be moved up and down. The cooling process is processed by lowering the plate 6 and bringing it into contact (pressurization) with the mold set 15 placed on the plate 3.

  In addition, a heater may be similarly provided in the plates 3 and 6 in the cooling zone, or water cooling may be achieved.

  The IN port table 9 is provided with a table elevating cylinder 11a at the lower part, and is configured to be able to move up and down. The IN port table 9 moves up and down to convey the mold set 15 placed on the table from the IN port load lock chamber 12 into the molding chamber 8. Although the table elevating cylinder 11a is provided as an actuator, another actuator such as an electric actuator may be used.

  The OUT port table 10 is provided with a table elevating cylinder 11b at the lower part, and is configured to be able to move up and down. The OUT port table 10 moves up and down to convey the mold set 15 placed on the table from the molding chamber 8 to the OUT port load lock chamber 13. Although the table elevating cylinder 11b is provided as an actuator, another actuator such as an electric actuator may be used.

  The IN port load lock chamber 12 has a lid-like configuration. When the IN port table 9 is raised to form the bottom side of the IN port load lock chamber 12, the mold set 15 is placed. At that time, the inside of the IN port load lock chamber 12 is replaced with nitrogen gas, and the IN port table 9 is lowered and transported into the molding chamber 8 replaced with nitrogen gas.

  The OUT port load lock chamber 13 has a lid-like configuration. When the mold set 15 is placed on the OUT port table 10, the OUT port table 10 is raised to form the bottom side of the OUT port load lock chamber 13 that is replaced with nitrogen gas. Thereafter, the lid-shaped OUT port load lock chamber 13 is opened, and the mold set 15 is taken out.

  In the figure, one heating zone, one pressing zone, and one cooling zone are provided. However, a plurality of zones may be provided in consideration of molding tact and the like.

  FIG. 2 shows an example of a transport device that transports the mold set 15 in the molding chamber 8 between each table and each plate. The example shown in FIG. 2 shows a state in which the inside of the molding chamber 8 is viewed from above, and has a configuration using a robot arm. In the figure, a mold transport unit 51 for transporting from the intake zone to the heating zone, a mold transport unit 52 for transporting from the heating zone to the press zone, a mold transport unit 53 for transporting from the press zone to the cooling zone, and a removal zone from the cooling zone. It is comprised from the metal mold | die conveyance unit 54 conveyed to.

  Here, although the conveyance unit is arrange | positioned between each zone, you may share several conveyance unit by one. In addition, if the IN port table 9 and the OUT port table 10 in the lowered state are arranged so that the upper surfaces of the lower plates 1, 2, and 3 of each zone are on the same horizontal plane, the mold set 15 is moved horizontally. The transport unit has only a simple mechanism with a low degree of freedom.

  FIG. 3 shows a cross section of the mold set 15. The mold set 15 includes an upper mold 16 having guide holes and a lower mold 18 having guide pins 17. A glass material 19 is placed between the upper mold 16 and the lower mold 18. This glass material 19 is heated and press-molded as a mold set 15 in the molding chamber 8.

  FIG. 4 shows the configuration of the infrared lamp heater unit 4 in detail. The infrared lamp heater unit 4 has three infrared lamp heaters 22 processed in an arc shape arranged in a vertical arrangement. A reflection mirror 23 is provided on the outer periphery of the infrared lamp heater 22. The reflecting mirror is plated with gold in consideration of the reflected light rate of radiant heat.

  Further, a thermocouple 24 supported by a spring 25 is provided on the upper portion of the infrared lamp heater unit 4 so that the tip of the thermocouple 24 contacts the mold set 15 when the infrared lamp heater unit 4 is lowered. Has been. When the tip of the thermocouple 24 comes into contact with the mold set 15, the glass material in the mold set 15 comes into contact with the upper part of the mold set 15 without being softened. It is supported by the spring 25 so that a strong force is not generated and the molding surface is not damaged. Further, the spring 25 is configured to absorb some variation in height of the mold set 15.

  The mold set 15 is adjusted to a desired temperature by a control device (not shown) using the thermocouple 24 and a thermocouple (not shown) provided on the plate 1. That is, the mold set 15 conveyed to the heating zone is surrounded by the lower plate 1 and the infrared lamp heater unit 4 and is heated by heat transfer from the lower part and by radiant heat from the outer peripheral part and the upper part.

  The non-contact heating means using the infrared lamp heater 22 shown in FIG. 4 is based on radiation of a resistance heating device. As such a resistance heating device, a heating wire such as a SiC (silicon carbide) heater, a carbon heater, or a nichrome wire may be used.

  Moreover, although the infrared lamp heater unit 4 is arrange | positioned at the outer peripheral part of the metal mold | die set 15, you may make it arrange | position at an upper part or an outer peripheral part and an upper part.

  Next, the operation of the glass forming apparatus of the present invention in such a configuration will be described.

  First, using an optical glass (material) having a yield point of 650 ° C., an optical lens having a diameter of 30 mm is molded using the mold set 15 at a temperature of 640 ° C. and a pressing force of 12 kN. In the following description, it is assumed that a glass material is placed on the mold set 15 in advance.

  In FIG. 1, the glass forming apparatus fills the molding chamber 8 with an inert gas, and fills the IN port load lock chamber 12 with an inert gas in a mold set 15 placed in the IN port load lock chamber 12. Thereafter, the IN port table 9 is used to take the IN port load lock chamber 12 into the molding chamber 8.

  The mold set 15 on the IN port table 9 in the intake zone is transported by the mold transport unit 51 to the plate 1 in the heating zone.

  The mold set 15 on the plate 1 is heated by heat transfer from the sheath heater 1 a and radiant heat from the infrared lamp heater 22.

  The mold set 15 heated to a temperature of 640 ° C. is transported to the plate 2 in the press zone by the mold transport unit 52.

  The mold set 15 on the plate 2 is pressed by the plate 5 lowered by the air cylinder 7b, and the glass material in the mold set 15 is press-molded. In the press zone, the temperature of the mold set 15 is maintained by the sheath heater 2 a of the plate 2 and the sheath heater 5 a of the plate 5.

  The mold set 15 on the plate 2 after press molding is transported to the plate 3 in the cooling zone by the mold transport unit 53 and cooled.

  The mold set 15 on the cooled plate 3 is transferred to the OUT port table 10 in the take-out zone by the mold transfer unit 53.

  The glass molded mold set 15 is transferred from the molding chamber 8 to the OUT port load lock chamber 13 filled with an inert gas on the OUT port table 10, and the OUT port load lock chamber 13 is opened and taken out.

  As a result of performing the above-described operation with the same power consumption as before, it was possible to heat the mold set 15 substantially uniformly in 60% of the heating time compared to the conventional glass forming apparatus.

  In addition, the heating variation of the mold set 15 also had an error of about ± 5 ° C. in the conventional glass forming apparatus, but the glass forming apparatus of the present invention can be suppressed to about ± 1 ° C. As a result, the variation in accuracy of the glass molded product was stabilized.

  Further, in the conventional glass forming apparatus, the molding surface of the mold set 15 is sometimes damaged, but in this embodiment, the molding surface is not damaged.

  FIG. 5 shows a configuration example of heating using the high frequency induction coil 61 instead of the infrared lamp heater 22 in the heating zone.

  As shown in the figure, an eddy current is generated near the surface of the mold set 15 by passing an alternating current through the high frequency induction coil 61 in the unit 60, and the mold set 15 is heated by Joule heat. In this configuration, the mold set 15 must be a conductor. In this way, the mold set 15 is heated, and the glass material inserted into the mold set 15 is indirectly heated.

  FIG. 6 shows a configuration example in which a heating device from the side surface is added in the press zone.

  As shown in the figure, a unit 70 having a plate 75 provided with a sheath heater 75a, an infrared lamp heater 72, and a reflection mirror 73 is configured. The unit 70 and the plate 2 provided with the sheath heater 2a constitute a press zone. With such a configuration, the mold set 15 can be heated from the side surface even in the press zone. The plate 75 of the unit 70 presses the mold set 15 by the air cylinder 7b as shown in FIG.

  As described above, according to the embodiment of the present invention, it is possible to realize power saving and highly accurate heating.

  In addition, it has become possible to stably and accurately mold large lenses or lenses having complicated shapes that have been difficult to mold.

  In addition, it is possible to reduce the damage to the mold as compared with the prior art.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

Schematic which shows schematic structure of the glass forming apparatus which shape | molds the optical glass element which concerns on this invention. The figure which shows the example of the conveyance means which conveys the metal mold | die group in a molding chamber between each table and each plate. The figure which shows the cross section of a metal mold set. The figure which shows the structure of an infrared lamp heater unit in detail. The figure which shows the structural example of the heating using a high frequency induction coil. The figure which shows the structural example which added the heating apparatus from the side in a press zone.

Explanation of symbols

  1, 2, 3, 5, 6, 75 ... plate, 4 ... infrared lamp heater unit, 7a, 7b, 7c ... air cylinder, 8 ... molding chamber, 9 ... IN port table, 10 ... OUT port table, 11a, 11b Table lifting cylinder, 12 IN port load lock chamber, 13 OUT port load lock chamber, 15 Mold set, 16 Upper mold, 17 Guide pin, 18 Lower mold, 19 Glass material, 20 Open / close actuator, 22, 72 ... Infrared lamp heater, 23, 73 ... Reflection mirror, 30 ... Vacuum pump, 40 ... Nitrogen gas supply unit, 51, 52, 53, 54 ... Mold transfer unit, 60, 70 ... unit, 61 ... High frequency induction coil.

Claims (8)

In a glass molding apparatus that molds a mold set in which a glass material is placed between an upper mold and a lower mold by heating and pressing,
A glass forming apparatus comprising heating means that is moved in the vicinity of a mold set on which the glass material is placed and heats in a non-contact manner.   The glass molding apparatus according to claim 1, wherein the mold set on which the glass material is placed is further placed on a plate provided with a heater and heated by heat transfer.   The mold set on which the glass material is placed is characterized in that the heating power is controlled by adjusting the power supplied to the heating means according to the measurement result of the surface temperature of the mold set. Or the glass forming apparatus described in 2.   The said heating means provided the non-contact heater in the outer peripheral part or upper part of the metal mold | die set | placed with the said glass raw material, or the outer peripheral part and upper part, The Claim 1 or 2 or 3 characterized by the above-mentioned. Glass forming equipment.   4. The glass forming apparatus according to claim 1, wherein the heating means performs radiant heating using an infrared lamp heater disposed on an outer peripheral portion of a mold set on which the glass material is placed. .   4. The glass forming apparatus according to claim 1, wherein the heating means performs radiant heating using a resistance heating apparatus disposed on an outer peripheral portion of a mold set on which the glass material is placed. .   The said heating means performs high frequency induction heating using the high frequency induction coil arrange | positioned in the outer peripheral part centering on the metal mold | die group in which the said glass raw material was set | placed, The claim 1 or 2 or 3 characterized by the above-mentioned. Glass forming equipment.   The said heating means is arrange | positioned in the outer peripheral part of the metal mold | die group in which the said glass raw material was set | placed, and performs radiant heating using the resistance heating apparatus comprised by the cylindrical shape, The said 1 or 2 or 3 characterized by the above-mentioned. The glass forming apparatus described in 1.

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