JP2003095675A - Apparatus for molding glass element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for molding a glass element in which it is possible to seal a molding chamber even at a molding temperature of 1,000 deg.C or higher for molding quartz glass or the like. SOLUTION: In the apparatus for molding the glass element, a glass material 35 is placed between a pair of openable molds that can abut to each other in the molding chamber 17; the molds and the glass material 35 are heated with infrared lamps 20; and the glass element is molded by pressing the glass material 35. The apparatus for molding the glass element comprises the molding chamber 17 that is constructed to be a closed space by a transparent quartz tube 16 and plates provided at the top and bottom thereof, seal members 30 and 31 mounted on the plates for sealing between the plates and the transparent quartz tube 16, and masking shields 40 and 41, each placed at the top and bottom of the infrared lamps 20 placed around the transparent quartz tube 16, for shielding radiation heat to the seal members 30 and 31, wherein air is forced to flow to the outer peripheral surface of the transparent quartz tube 16 between the masking shields 40 and 41 and the plates to cool it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding device for glass elements such as glass lenses and prisms, and in particular, a glass material is arranged between a pair of openable and closable molds which can be in contact with each other. The present invention relates to a glass element molding apparatus for molding a glass element by heating a glass material and pressing the glass material.

[0002]

2. Description of the Related Art The production of glass elements such as glass lenses, which require high precision, is accomplished by grinding and polishing a glass material formed by molding molten glass into a shape close to the final molded product, and by melting glass in the same manner. Is roughly divided into two types, one is a glass material that is molded into a weight and a shape according to the final molded product, and the other is finished by reheat pressing with a precision mold.

Manufacturing by grinding and polishing requires more than a dozen steps to form a curved surface, and a large amount of glass grinding powder harmful to the operator is generated. It has a drawback that it is difficult to manufacture a large number of glass elements having a surface with the same accuracy.

On the other hand, the reheat press is a method of transferring the shape of a mold to a glass material to form a glass element, and therefore the step required for curved surface forming is only one step of press forming and is clean. It has an advantage that it can be manufactured in an environment, and that once the mold is manufactured, a large number of glass elements can be manufactured according to the accuracy of the mold.

When the glass material is heated by using the infrared lamp, it is necessary to cool the infrared lamp itself in order to protect the infrared lamp from heat generation of the infrared lamp itself. Therefore, place the infrared lamp outside the molding chamber,
It is effective to make the mold and the infrared lamp thermally independent. To place the infrared lamp outside the molding chamber,
It is necessary for the molding chamber to transmit infrared rays, and conventionally quartz glass having a high infrared transmittance is used.

Further, in order to prevent the oxidation of the mold made of metal or the like, it is necessary to eliminate oxygen around the mold. Therefore, the mold and the glass material should be confined in the molding chamber and the molding chamber should be filled with an inert gas. A method of purging oxygen or a method of evacuating the molding chamber is used.

However, since it is difficult to manufacture the entire molding chamber from quartz glass, the side surface portion of the mold and the glass material that irradiates infrared rays is covered with a quartz glass tube, and the portion not irradiated with infrared rays is made of metal or the like. We are making a molding room. O-rings are used to seal the space between the quartz glass and the metal in order to increase the degree of tightness in the molding chamber.

[0008]

When molding a glass material that requires a high molding temperature, such as quartz glass, the molding temperature becomes about 1350 ° C to 1600 ° C, and the quartz glass tube is also air-cooled. However, some of them are heated to a temperature of 500 ° C. or higher. Therefore, the heat transfer from the quartz glass tube also heats the O-ring in contact with the quartz glass tube. Further, since the infrared rays reach the O-ring while reflecting in the quartz glass, even if the infrared lamp is installed at a place separated from the O-ring, it is heated. Further, the O-ring is directly heated by the radiant heat of the infrared lamp. Therefore, it is necessary to use an expensive heat-resistant material for the O-ring, but the life is still short,
There was a problem that it had to be replaced frequently, which was disadvantageous in terms of cost.

It is an object of the present invention to use 10 such as quartz glass.
An object of the present invention is to provide a glass element molding apparatus capable of sealing a molding chamber for a long period of time even at a molding temperature of 00 ° C. or higher.

[0010]

In order to achieve the above-mentioned object, according to claim 1 of the present invention, a glass material is arranged between a pair of openable and closable molds capable of abutting each other in a molding chamber, A glass element molding apparatus for molding a glass element by heating the mold and the glass material with an infrared lamp to press the glass material, and a space closed by a transparent quartz tube and plates provided above and below the transparent quartz tube. And a sealing member installed on the plate, which seals between the plate and the transparent quartz tube to prevent air from flowing into the molding chamber. Shielding plates arranged above and below the arranged infrared lamps to shield radiant heat to the sealing member, and cooling means for forcibly flowing air to the outer peripheral surface of the transparent quartz tube between the shielding plate and the plate for cooling. When It was characterized in that it has. As described above, since the shielding plates for shielding the radiant heat to the seal member are provided above and below the infrared lamp and the vicinity of the installation position of the seal member is cooled, the life of the seal member is extended and the number of replacements is reduced. .

Further, the seal member is preferably an O-ring made of either fluorine or silicon.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG. In FIG. 1, the frame 1
A drive device (die opening / closing device) 8 such as a screw jack which uses the servo motor 8a as a drive source and converts the rotational motion of the servo motor 8a into a linear motion thrust is attached to the lower part of the. A moving shaft 9 is attached to the drive device 8 via a load detection device 8b. A lower die assembly 11 including a die plate 12, a lower die 13 and a moving die 14 is attached to the upper end of the moving shaft 9 via a heat insulating cylinder 10 made of ceramic.

An upper end of a fixed shaft 2 is attached to an upper portion of the frame 1, and a lower end of the fixed shaft 2 is composed of a die plate 5, an upper die 6 and a fixed die 7 via a ceramic heat insulating cylinder 3. The upper mold assembly 4 is attached.

A bracket 15 which is vertically moved by a driving device (not shown) is movably engaged with the fixed shaft 2, and a transparent quartz tube 16 surrounding the molds 6 and 13 is attached to the bracket 15 by an O-ring 30. Is attached through. The lower end of the transparent quartz tube 16 abuts on the upper surface of the mounting seat 1b via an O-ring 31 to form an airtight molding chamber 17 around the molds 6 and 13. A water cooling pipe (not shown) is built in the bracket 15 and the mounting seat 1b to cool the sealing O-rings 30 and 31.

Further, the transparent quartz tube 1 is attached to the bracket 15.
A lamp unit 19 for surrounding the periphery of 6 and heating the molds 6, 13 and the glass material 35 is attached.
The lamp unit 19 includes an infrared lamp 20, a reflection mirror 21 arranged behind the infrared lamp 20, and a water cooling pipe (not shown) for cooling the reflection mirror 21.

The fixed chamber 2 and the movable shaft 9 are provided with a molding chamber 1
Gas supply paths 22 and 23 for supplying an inert gas are provided in order to create an inert gas atmosphere in 7 and to cool the molds 6 and 13. Further, the mounting seat 1b is provided with an exhaust port 24 for exhausting air and an inert gas from the molding chamber 17.

Shielding plates 40 and 41 for shielding the radiant heat to the O-rings 30 and 31 are installed above and below the lamp unit 19 arranged around the transparent quartz tube 16 with a slight gap on the transparent quartz tube 16 side. .

In the upper spacer 27, a plurality of air supply passages 28 for the quartz tube cooling air 32 are provided in the circumferential direction near the upper flange portions of the bracket 15 and the transparent quartz tube 16 which are in contact with the O-ring 30. Provided and lower spacer 37
The O-ring 31 of the mounting seat 1b and the transparent quartz tube 16.
The quartz tube cooling air 3
3, a plurality of air supply passages 38 are provided in the circumferential direction. Further, the upper and lower spacers 27, 37 are provided with exhaust ports 29, 39 for exhausting air, respectively.

Reference numeral 26 is a control device, which is a load detecting device 8b.
And the output of the temperature detecting thermocouple 25 attached to the lower mold assembly 11, and the servo motor 8a is driven by these outputs and a program given separately, to detect the speed, position, and position of the moving shaft 9. The press force is controlled and the output of the lamp unit 19 and the supply of the inert gas are controlled to perform desired molding.

Next, the operation of this apparatus and the method for molding a glass element according to the present invention will be described. The glass material 35 is placed on the lower mold 13 in a state where the moving shaft 9 is lowered, the molding chamber 17 is formed by the transparent quartz tube 16, and the supply path 22,
An inert gas is supplied from 23 to make the inside of the molding chamber 17 an inert gas atmosphere, and the lamp unit 19 heats the molds 6, 13 and the glass material 35.

When the temperature of the molds 6 and 13 is stabilized at a preset press temperature, the moving shaft 9 is raised to completely close the molds 6 and 13 to perform pressing. The moving shaft 9 is moved up and down in a state where the servo motor 8a is driven by a program input to the control device 26 and the speed, position and pressing force are controlled.

Next, the output of the lamp unit 19 is reduced and the supply amount of the inert gas from the supply paths 22 and 23 is controlled to lower the temperature of the molds 6 and 13 with a predetermined temperature gradient.
Although the process shifts to the cooling process, the pressing force by the moving shaft 9 is controlled and the pressing is continued during this cooling process.

When the temperature of the mold 13 has dropped to around the transition temperature, the pressing force of the moving shaft 9 is released, and the mold 13 is released.
When the temperature of the molding chamber 1 further decreases, the molds 6 and 13 are opened and the supply of the inert gas to the molding chamber 54 is stopped,
Open 7 and take out the glass element.

The shield plates 40 and 41 installed above and below the lamp unit 19 shield the radiant heat to the O-rings 30 and 31, suppress the temperature rise of the O-rings 30 and 31 due to the radiant heat, and during the molding of the glass material. , O-rings 30, 31
In order to prevent the temperature from rising, the air supply passage 2 provided near the upper and lower flanges of the bracket 15 and the mounting seat 1b and the transparent quartz tube 16 in contact with the O-rings 30 and 31.
Quartz tube cooling air 32, 33 is forced to flow from 8 and 38 to cool the upper and lower flange portions of the transparent quartz tube 16. The cooled air is exhausted from the exhaust ports 29 and 39.

EXAMPLE Shielding plates 40, 4 installed above and below the lamp unit 19
1 and the quartz tube cooling air 32, 33 to confirm the effect, the test, assuming the molding of quartz glass, the mold 6, 1
3 and the glass material 35 were heated to 1400 ° C., held for 120 seconds, and cooled to 200 ° C. Also,
The O-rings 30 and 31 are made of two types of materials, a white silicon O-ring and a black fluorine O-ring.
Was used with and without.

The test is conducted 200 times, and the appearance of the O-rings 30 and 31 is changed and the molding chamber 17 is changed.
I investigated the occurrence of leaks. FIG. 2 shows the result of the effect test of the quartz tube cooling air according to the present invention.

As shown in FIG. 2, a black fluorine O-ring was used, and smoke was generated and melted 5 times without using the quartz tube cooling air 32, 33. On the other hand, a black fluorine O-ring is used, and the quartz tube cooling air 32, 33 is 200
No abnormalities were found even after repeated use, and the quartz tube cooling air 32,
It was confirmed that there was an effect when 33 was used.

On the other hand, when a white silicon O-ring was used and the quartz tube cooling airs 32 and 33 were not used, a slight discoloration was observed after 100 times, and a discoloration and a leak occurred after 200 times. On the other hand, when the white silicon O-ring is used and the quartz tube cooling airs 32 and 33 are used, no abnormality is observed even after 200 times, and there is an effect when the quartz tube cooling airs 32 and 33 are used. It could be confirmed. From the above test results, it was confirmed that cooling the vicinity of the flange portion of the transparent quartz tube 16 with air is effective regardless of the materials and colors of the O-rings 30 and 31.

[0029]

As described above, according to the present invention, shield plates for shielding the radiant heat to the O-ring are provided above and below the infrared lamp, and the plates and transparent quartz tubes provided above and below the transparent quartz tube are provided. Since the upper and lower flanges that are in contact with the O-ring are forcibly cooled, the life of the O-ring is extended, and the molding chamber is sealed for a long time even at a molding temperature of 1000 ° C or higher like quartz glass. It has become possible to provide a glass element molding apparatus capable of forming the glass element.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a glass element molding apparatus according to the present invention.

FIG. 2 is a view showing a result of an effect test of a quartz tube cooling air according to the present invention.

[Explanation of symbols]

1 frame 1b Mounting seat 2 fixed axis 3, 10 heat insulation tube 4 Upper mold assembly 5, 12 die plate 6 Upper mold 7 Fixed die 8 drive 8a Servo motor 8b load detection device 9 axis of movement 11 Lower mold assembly 13 Lower mold 14 Mobile die 15 bracket 16 Transparent quartz tube 17 Molding room 19 lamp unit 20 infrared lamp 21 reflective mirror 22, 23 gas supply channel 24, 29, 39 exhaust port 25 Thermocouple for temperature detection 26 Control device 27 Upper spacer 28, 38 Air supply path 30, 31 O-ring 32, 33 Quartz tube cooling air 35 glass material 37 Lower spacer 40, 41 Shield plate

Claims (2)

[Claims] 1. A glass element is formed by arranging a glass material between a pair of openable and closable molds that can abut each other in a molding chamber, and heating the mold and the glass material with an infrared lamp to press the glass material. A molding device for a glass element, comprising: a molding chamber configured to be a space closed by a transparent quartz tube and plates provided above and below the transparent quartz tube; and a sealing between the plate and the transparent quartz tube, A seal member installed on the plate for preventing the inflow of air into the molding chamber, and shield plates arranged above and below the infrared lamps arranged around the transparent quartz tube, respectively, for shielding radiant heat to the seal member. A glass element molding apparatus comprising: a cooling unit configured to forcibly flow air to the outer peripheral surface of the transparent quartz tube between the shielding plate and the plate for cooling. 2. The glass element molding apparatus according to claim 1, wherein the seal member is an O-ring made of either a fluorine-based material or a silicon-based material.