JP2001010829A - Apparatus for press molding glass and its operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time required for raising and dropping a temperature in a chamber before and after a maintenance and checking operation in a press molding apparatus and to improve the productivity of press molding. SOLUTION: This press molding apparatus 10 is equipped with a heating chamber 20 provided with a glass heating means 22 for heating a glass material G, a molding chamber 30 provided with a pressing means 33 for press molding the heated glass material and a mold heating means 34 for heating the molding mold of the pressing means, a route 40 to connect the heating chamber 20 to the molding chamber 30, a shutter which 41 is opened so as to transport the glass material through the route 40 and, in carrying out an operation in the molding chamber 30, is closed so as to make a gas change impossible in the heating chamber 20 and the molding chamber 30 and an opening and closing door 35 for operation installed in the molding chamber 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press forming apparatus for glass for optics and the like and a working method thereof, and more particularly to a press forming apparatus capable of shortening the time required for replacing and maintaining a press forming die and the like. Regarding the working method.

[0002]

2. Description of the Related Art In recent years, a press forming apparatus for forming a high-precision optical lens which does not require polishing after pressing has been actively developed. In this type of press forming apparatus, a glass preform, that is, a glass material preformed for press forming, is preheated to about the glass transition point by a resistance heating device using a resistor or the like, and separately,
It is pressed with a mold heated by a high-frequency induction heating device or the like to form a desired optical glass shape.

In order to maintain high surface accuracy of optical glass in press molding, it is important to perform high-level maintenance and management especially on the molding surface of a molding die. Since the mold is heated to a high temperature prior to pressing, the molding surface is exposed to the risk that the surface accuracy is reduced due to oxidation. Therefore, conventionally, in a chamber gas-exchanged to a non-oxidizing gas such as nitrogen gas, heating and pressing the glass preform,
Widely used.

[0004] However, even in such a non-oxidizing gas atmosphere, by repeatedly performing pressing,
Since the surface accuracy of the molding surface may be reduced, glass may adhere to the surface, or parts may be damaged, workers access the chamber regularly (for example, once every few days), It is necessary to perform maintenance and inspection.

In a conventional press forming apparatus of this kind,
When the maintenance and inspection of the mold is required, the operator performs the following procedure. (1) Turn off the power to the heating device for the mold and the glass, and wait until the temperature in the chamber decreases. (2) When the temperature in the chamber becomes close to room temperature,
Open the door provided in the chamber and access the inside to perform necessary maintenance or inspection. (3) Close the door, exhaust the air in the chamber,
Fill with non-oxidizing gas. (4) The molding device and the heating device for the glass are relayed, and the temperature of these and the inside of the chamber are waited for to rise to a predetermined temperature. (5) Supply the glass preform into the chamber and restart press molding.

[0006]

However, after maintenance or inspection, it takes a considerable amount of time to raise the temperature of each heating device and the inside of the chamber to a predetermined temperature. Since the maintenance or inspection work needs to be performed periodically, the required time hinders an improvement in press molding productivity. Particularly, as a heating device for the glass preform, resistance heating using a resistor is usually employed, and particularly, it takes time to raise and lower the temperature.

Accordingly, an object of the present invention is to provide a press forming apparatus and a press forming apparatus capable of improving the press forming productivity by shortening the time required for lowering and raising the temperature in the chamber before and after the maintenance or inspection work. It is to provide a maintenance method.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a forming apparatus for forming a glass by pressing a glass material. The molding apparatus of the present invention is a hermetic heating chamber which is brought into a non-oxidizing gas atmosphere during press molding, and at least inside thereof, a glass heating means for heating the glass material to soften it to a predetermined viscosity. A first transporting means for transporting the glass material, loading means for loading the glass material into the heating chamber while maintaining a non-oxidizing gas atmosphere in the heating chamber, A pressurizing unit provided with a forming die for pressing the conveyed glass material to form a predetermined optical glass shape by pressurizing the conveyed glass material at least in an airtight forming chamber to be oxidized gas atmosphere; A mold heating means for heating the mold to a predetermined temperature, and a second conveying means for taking out the pressed glass from the mold and conveying the same, and a non-oxidizing gas in the molding chamber. An unloading unit that enables the glass to be unloaded outside the forming chamber while maintaining the atmosphere, and the heating chamber and the forming chamber communicate with each other, and the first transfer unit transfers the glass material in the heating chamber into the forming chamber. When the glass material in the heating chamber is conveyed into the molding chamber by the first conveying means, the passage is opened to enable the glass material to be conveyed through the passage. Along with
When working in the molding chamber, a shutter that is closed to disable gas exchange between the heating chamber and the molding chamber, and when working in the molding chamber, an operator enters the molding chamber. An opening / closing door provided in the molding chamber which is opened for access.

The above-mentioned glass material includes a glass preform in which glass is formed into a predetermined shape in advance, and a glass knot obtained by cutting molten glass or further adjusting the viscosity and shape.

In this case, it is preferable that the shutter thermally shuts off the heating chamber and the molding chamber when working in the molding chamber.

Further, it is preferable that the shutter is a gate valve provided with an airtight member around the shutter.

Further, it is preferable that the mold heating means heats the mold by high-frequency induction heating.

Preferably, the glass heating means heats the glass material by resistance heating using a resistor.

[0014] Further, it is preferable that the opening / closing door is provided with a window made of a light-transmitting member which allows the inside of the molding chamber to be visually recognized.

The present invention also relates to a working method in a press forming apparatus. That is, a heating chamber for heating a glass material supplied from the outside to soften the glass material to a predetermined viscosity, and a molding chamber for pressing the glass material with a heated mold to form a predetermined glass shape. And a shutter for opening and closing a passage that allows the glass material to be conveyed from the heating chamber to the molding chamber, and an opening / closing door for accessing the molding chamber. A step of stopping supply and conveyance of the glass material, a step of closing the shutter to shut off the heating chamber and the molding chamber so that gas cannot be exchanged, a step of lowering the ambient temperature in the molding chamber, and To allow operation in the molding chamber by opening the opening.

Here, the "work" in the molding chamber is:
Includes maintenance and inspection work to repair, replace, or inspect various devices and parts installed in the molding room.

Further, after the operation in the molding chamber is completed,
Closing the opening / closing door and exchanging gas in the molding chamber with a non-oxidizing gas atmosphere, heating the molding die to a predetermined temperature, opening the shutter, supplying and transporting the glass material; And a step of restarting the process.

Further, it is preferable that the shutter thermally shuts off the heating chamber and the molding chamber when working in the molding chamber.

Preferably, the mold is heated by high-frequency induction heating.

Further, it is preferable that the glass material is heated by resistance heating by a resistor in the heating chamber.

Further, it is preferable that the molding die is provided with a carbon-based thin film on a molding surface thereof.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic plan sectional view of a press forming apparatus according to one embodiment of the present invention. As shown in the figure,
The press forming apparatus 10 according to the present embodiment includes a heating chamber 20 and a forming chamber 30. The heating chamber 20 and the molding chamber 30 are communicated with each other through a passage 40, and the heating chamber 20, the molding chamber 30, and the passage 40 form one closed space that is isolated from the outside. The outer wall of the closed space is formed by stainless steel or other members, and the airtightness can be ensured by the sealing material. The sealed space formed by the heating chamber 20, the forming chamber 30, and the passage 40 is set to a non-oxidizing gas atmosphere when forming the optical glass. That is, the air in the space is exhausted by a gas exchange device (not shown), and the space is filled with a non-oxidizing gas. Nitrogen gas is preferably used as the non-oxidizing gas.

The heating chamber 20 is an area for preheating the supplied glass preform G prior to pressing, and includes a glass heating device 22 and a handler for supplying the glass preform (hereinafter referred to as a supply handler). 23). Further, a carry-in section 21 for supplying the glass preform G from the outside into the heating chamber 20 is provided. The carry-in section 21 is provided with a carry-in chamber (not shown) for carrying the glass preform while maintaining the airtightness. The carry-in section 21 carries the glass preform supplied from the outside into the carry-in chamber, and supplies the inside with a non-oxidizing gas. After filling, the glass preform is sequentially carried into the inside by opening the door on the heating chamber 20 side.

The supply handler 23 conveys the glass preform G carried in from the carry-in section 21 to a heating area by the glass heating device 22, and further conveys the heated glass preform to the molding chamber 30. The supply handler 23 has a floating plate 25 at the end of the arm 24, and holds the glass preform while floating on it. In the embodiment, the driving unit 23a fixed in the heating chamber 20
An arm 24 having a floating dish 25 is horizontally supported, and the arm 24 is rotated in a horizontal direction at a rotation angle of about 90 ° C. Further, the arm 24 is configured to be able to move back and forth in the radial direction with the drive unit 23a as a center.
The held glass preform can be transported to the molding chamber 30. Details of the supply handler 23 and the floating plate 25 will be described later.

The glass heating device 22 is for heating the supplied glass preform G to a temperature corresponding to a predetermined viscosity. In order to stably raise the temperature of the glass preform to a certain temperature, it is preferable to use a heating device by resistance heating using a resistance element. As shown in the figure, the glass heating device 22 is installed along the movement trajectory of the glass preform held on the arm 24, and therefore, heats the glass preform while the glass preform is being conveyed by the arm 24. Can be. However, the arm 24 may be stopped on the glass heating device 22 for a predetermined time to heat the glass. These items are determined according to the time required for heating the target glass.

On the other hand, the molding chamber 30 presses the glass preform G preheated in the heating chamber 20 to form a glass having a desired shape (hereinafter referred to as an optical glass G).
Where the pressing device 3 is formed.
3 and a handler for carrying out the optical glass (hereinafter, referred to as a carry-out handler 32). Further, an unloading section 31 for unloading the press-formed optical glass to the outside is provided. The unloading section 31 includes an unillustrated unloading chamber filled with a non-oxidizing gas to unload the optical glass to the outside while maintaining the airtightness of the molding chamber 30. The optical glass delivered from the carry-out handler 32 is once carried into the carry-out chamber and then carried out.

The pressing device 33 receives the glass preform conveyed from the heating chamber 20 by the supply handler 23, and presses it to form an optical glass having a desired shape. As will be described later, the press device 33 includes a molding die including an upper die and a lower die, and presses the glass preform supplied therebetween by using the molding surfaces. A mold heating device 34 for heating the mold is provided around the mold. A preferred embodiment of the mold heating device 34 is of a heating type using high frequency induction. Prior to pressing of the glass preform, the mold is heated by the mold heating device 34 to maintain a predetermined temperature. The temperature of the mold during pressing may be approximately the same as or lower than the temperature of the preheated glass preform. Details of the mold and the mold heating device in the embodiment will be described later.

The unloading handler 32 transfers the optical glass pressed by the pressing device 33 to the unloading section 31. The carry-out handler 32 has a suction pad 32c at the tip of an arm 32b rotatably supported by the drive unit 32a. The suction pad 32c vacuum-adsorbs the optical glass on the lower mold of the molding die and enables the carry-out handler 32 to convey the optical glass. The optical glass sucked by the rotation of the arm 32b is conveyed below the unloading section 31, and
It is placed on lifting means (not shown) installed here. After the arm 32b is retracted, the elevating means is raised, and the optical glass is delivered to the carry-out section 31.

The molding chamber 30 has a door 3 on its front side.
5 is provided. The opening / closing door 35 allows an operator to access the inside of the molding chamber during maintenance and inspection of the press molding apparatus. A seal member 35a is provided around the opening / closing door 35, and airtightness in the molding chamber 30 is ensured when the opening / closing door 35 is closed at the time of pressing. The opening / closing door 35 also has a window 35b made of glass (for example, quartz glass).
From here, the state of press molding can be visually recognized from the outside.

In the present embodiment, the heating chamber 20 and the molding chamber 30 are connected by a passage 40. The passage 40 enables the supply handler 23 to transfer the glass preform from the heating chamber 20 to the molding chamber 30 and also allows gas exchange between the two chambers. Thereby, at the time of press molding, the pressure, gas concentration, and temperature of the heating chamber 20 and the molding chamber 30 are made substantially constant.

In the present invention, the passage 40 is provided with an airtight valve 41. The airtight valve 41, when closed, prevents the gas exchange between the heating chamber 20 and the molding chamber 30. The hermetic valve 41 is completely opened at the time of press molding, but is closed at the time of maintenance or inspection of the inside of the molding chamber 30 by an operator, and maintains the gas state of the heating chamber 20 side. The details of the airtight valve 41 will be described later.

FIG. 2 is a sectional view showing a forming die and a mold heating device in the press device 33. As shown in the figure, a molding die 50 includes upper and lower mother dies 51a, 5a, 5a formed in a cylindrical shape.
1b, upper mold 53a, lower mold 53b and upper and lower sleeves 5
2a and 52b. Opposite surfaces of the upper mold and the lower mold are molding surfaces 54a and 54b designed in accordance with the spherical surface of the optical glass to be molded. The glass preform G supplied by the supply handler 23 is placed on the lower mold surface 54b as shown in the figure, and is pressed by lowering the upper mold surface 54a. In a preferred embodiment, the upper mold 53a and the lower mold 53b are made of silicon carbide and have a formation surface coated with a hard carbon film. The sleeve 52a provided around the upper mold 53a is made up of the upper mold 53a and the mother mold 51a.
It is movable vertically. When the press, that is, when the upper mold 53a approaches the lower mold 53b, the upper sleeve 52a and the lower sleeve 52b come into contact with each other, the upper sleeve 52a is lifted upward, and the upper mold surface 54a advances toward the lower mold 53b. Enable. by this,
The molding surface 54a of the upper mold is located in the lower sleeve 52b in a state where the glass preform G is completely pressed.
A portion of this sleeve is located around the upper and lower mold surfaces 54 and defines the periphery of the optical glass from which it is molded. That is, the diameter of the optical glass is determined by the portion of the sleeve. Note that the upper and lower mother dies 51 are provided with guide pins 55a and corresponding holes 55b on their opposing surfaces to ensure the positioning of the molding dies during pressing. In a preferred embodiment, the sleeve is silicon carbide;
Each matrix is a tungsten alloy.

An induction heating coil 56 constituting a mold heating device is disposed around the molding die. The molding die 50 is heated to a predetermined temperature by the induction heating coil 56. That is, the mother die 51 constituting the outer surface of the molding die 50 is directly induction-heated by the induction heating coil 56, and the upper die 53a, the lower die 53b, and the sleeves 52a, 52b are indirectly transferred by heat conduction from the mother die. Heated. In one embodiment, the mold 50 is heated by the induction heating coil 56 to a predetermined temperature, for example, a temperature lower than the supplied glass preform (equivalent temperature required to obtain a viscosity of 10 ⁸ to 10 ¹² poise). After preheating, the glass preform G is received and pressed.

FIG. 3 is a plan view showing the tip of the arm of the supply handler 23 installed in the heating chamber 20 and a sectional view taken along line AA. At the end of the arm 24 of the supply handler, a floating plate 25 for holding the glass preform G is provided. The floating plate 25 has a mortar-shaped receiving portion 26 for holding the glass preform G. A non-oxidizing gas supplied through the arm 24 is supplied into the receiving portion, and the pressure of the gas causes the glass preform G to be conveyed while slightly floating in the receiving portion.

Here, the arm 24 and the floating plate 25
Are configured to be dividable in the width direction. Hereinafter, these are referred to as arm divided bodies 24a and 24b and floating dish divided bodies 25a and 25b. When the arm split bodies 24a, 24b are opened mutually by a drive mechanism (not shown) in the drive unit 23a, the floating dish split bodies 25a, 25b are also opened mutually, whereby the glass preform G in the receiving part 26 is It falls down from the floating plate 25. At a position where the floating plate 25 is located between the molds of the press device, the arm divided body 24
By opening a and 24b, the delivery of the glass preform from the supply handler 23 to the lower mold of the press device 33 is completed. In addition, as a material of the floating plate 25, a material obtained by converting the surface of high-density carbon into glassy carbon can be used.

FIG. 4 shows an embodiment of an airtight valve 41 installed on a passage 40 communicating the heating chamber 20 and the molding chamber 30. In the figure, the airtight valve 41 includes a cylinder 42 operated by air pressure, and the passage 40 is opened or closed by a shield 43 operated by the cylinder 42. Around the shield 43,
The sealing member 43a is provided, so that gas cannot be exchanged between the heating chamber 20 and the molding chamber 30 when the shield 43 is closed. In a preferred embodiment, the shield 43 is made of a material having high oxidation resistance, such as aluminum or stainless steel, and more preferably, this can minimize the heat exchange between the heating chamber 20 and the forming chamber 30. Use a material or structure. Those skilled in the art will understand what airtight valves that can be used in the present invention.

Next, the procedure of forming optical glass by the press forming apparatus 10 will be described. In the description, FIG. 1 and FIG. 5 are referred to. FIG. 5 is a flowchart showing a procedure for forming the optical glass. In the press forming apparatus 10, the glass preform G is sequentially supplied into the apparatus from the carry-in section 21, and the optical glass is continuously press-formed. Here, attention is paid to the forming of one optical glass. The procedure will be described.

Prior to molding, the gas in the heating chamber 20 and the gas in the molding chamber 30 are exchanged for a non-oxidizing gas. In an embodiment, the non-oxidizing gas is constantly supplied into the room and maintained at a positive pressure. In this non-oxidizing gas atmosphere, the glass heating device 22 and the mold heating device 34 are energized and maintained at a predetermined temperature. In this state, the airtight valve 41 on the passage is open.

In the first step, the glass preform G is supplied into the heating chamber 20 (501). Specifically, the glass preform G is first placed in the carry-in room of the carry-in section 21, and after being evacuated and replaced with gas, is supplied into the heating chamber 20. When supplying the glass preform, the arm 24 of the supply handler 23 is located below the loading section 21, and the glass preform from the loading chamber is placed on the floating plate 25 of the supply handler 23.

Upon receiving the glass preform G, the supply handler 23 immediately rotates its arm and moves the floating plate 25 onto the glass heating device 22. Here, the non-oxidizing gas is jetted from below the floating plate 25, so that the glass preform is heated and softened while floating on the floating plate 25 (502). The glass preform is heated for a predetermined time, and the temperature is 10 ⁶ to 10 ⁸
When the temperature reaches the temperature corresponding to the viscosity of the poise, the supply handler 23 is driven to place the glass preform in the molding chamber 3.
0 on the lower die of the press device 33 (50
3). That is, the arm 24 is further rotated from the heating position, and stopped when the floating plate 25 comes to a position facing the passage 40, and then the arm 24 is extended to extend the floating plate 25 between the molds of the press device 33. Further, the arm split body 24
a, 24b are opened and the glass preform G on the floating plate 25 is dropped onto the lower mold. Then, the supply handler 23
Moves the arm back to the initial position,
And waits to receive the next glass preform.

When the glass preform is supplied,
The temperature of the mold 50 is preheated to a temperature corresponding to a viscosity of 10 ⁸ to 10 ¹² poise by induction heating by the mold heating device 34. As shown in FIG.
Is supplied with the glass preform G, and the arm is
As soon as it is retracted outside 0, the lower mold 53b is raised,
The glass preform G is pressed with the upper mold 53a, and a desired optical glass is formed (504). Simultaneously with the rise of the lower mold 53b, the mold heating device 34 is turned off, and a non-oxidizing gas is flown into the mold and blown from the outside, thereby cooling the mold ( 50
5). Then, when the temperature of the mold falls below the glass transition point, the lower mold 53b is lowered to enable the optical glass to be carried out.

Next, the optical glass on the lower mold is conveyed to the unloading section 31 by the unloading handler 32 (506). That is, as shown in FIG. 1, the carry-out handler 32 is driven, the arm 32b is rotated, and the suction pad 32c at the tip is moved to the lower mold. The optical glass G on the lower mold is sucked by the suction pad 32c, the arm 32b is rotated, and the arm 32b is conveyed to the lifting / lowering means below the unloading section 31.
Release the adsorption of c and pass the optical glass onto the elevating means.
The optical glass is carried out of the molding chamber 30 via the carrying-out chamber of the carrying-out section 31 by moving up the elevating means (507). The mold heating device 34 is energized immediately after the optical glass is carried out of the lower mold, and heats the mold to a predetermined temperature in preparation for the next press molding. By performing the above procedure continuously, the optical glass is efficiently produced.

Next, the procedure of maintenance or inspection of the equipment in the molding chamber 30, particularly the molding die in the press unit 33, performed during the molding of the optical glass will be described.
In the description, FIG. 1 and FIG. 6 are referred to. FIG. 6 is a flowchart showing a procedure of maintenance or inspection work in the molding chamber 30. The molding surface of the molding die needs to be maintained with high precision, but the molding surface is deteriorated or glass adheres by a predetermined number of presses. For this reason, it is necessary to replace the battery periodically. In this case, the worker opens the door 35 to perform the work. In the following, a procedure from stoppage of press molding to maintenance or inspection of the molding chamber and resumption of press molding will be described.

In the first step, the operation of supplying and transporting the glass preform is stopped (601). Specifically, the loading of the glass preform from the loading section 21 is stopped, and the driving of the supply handler 23 and the unloading handler 32 is stopped.
Next, the airtight valve 41 on the passage is closed (602). As a result, gas exchange between the heating chamber 20 and the molding chamber 30 is prohibited. In this state, the mold heating device 34 is turned off,
The temperature in the molding chamber 30 is lowered (603). Since the mold heating device 34 performs heating by high-frequency induction heating,
The temperature in the molding chamber 30 can be lowered to the predetermined temperature in a relatively short time.

When the temperature in the molding chamber 30 reaches room temperature, the opening / closing door 35 is opened, and the operator accesses the interior of the molding chamber 30 and performs necessary maintenance or inspection work including replacement of the molding die ( 604). At the time of maintenance or inspection in the molding chamber, the airtight valve 41 is closed as described above, so there is no need to turn off the glass heating device 22, and the temperature in the heating chamber 20 is maintained at a high temperature. Is done. After the maintenance or inspection work is completed, the opening / closing door 35 is closed, and the airtightness in the molding chamber is maintained again. In this state, the molding chamber 3
The exhaust of the air in the chamber 0 and the introduction of the non-oxidizing gas are performed (605). Subsequently, the mold heating device 34 is energized, and the mold is heated to a predetermined preliminary temperature (606). When the temperatures in the molding die and the molding chamber reach a predetermined temperature, the airtight valve 41 on the passage is opened to allow gas exchange between the molding chamber 30 and the heating chamber 20, and the heating chamber 20 (60)
7). The glass preform is supplied into the heating chamber 20, and press molding is restarted (608). In a conventional press forming apparatus, it takes 4 to 5
While it took time, in one embodiment of the present invention, the work was completed in about 30 minutes.

Next, another embodiment of the present invention will be described. FIG. 7 is a schematic plan sectional view of a press forming apparatus according to another embodiment of the present invention. As in the previous embodiment, the press molding apparatus 70 according to the present embodiment includes a heating chamber 80, a molding chamber 90, and a passage 100 that connects them, and these form a closed space.

In the heating chamber 80, a glass heating device 83 for preheating the glass preform G, and a conveyor 84, a first handler 85, and a conveyer for conveying the glass preform from the carry-in portion 81 to the carry-out portion 82. A second handler 86 is provided. The glass preform G supplied from the loading section 81 is firstly conveyed by the conveyor 84 sequentially.
It is sent to the front of the handler 85. In this embodiment, the glass preform G has a substantially disk shape and is conveyed while being held by a cylindrical work 89. Conveyor 8
4, a resistance heater (not shown) is installed in the preheating zone 87 from the carry-in portion 81 to a position in front of the first handler 85, whereby the conveyed glass preform G is preheated to a predetermined temperature. When the glass preform G comes to a position in front of the first handler 85, the first handler 85 is driven to hold the glass preform G and transport it to the position of the glass heating device 83. The glass heating device 83 is a heating means using a resistance heater, where the glass preform G is rapidly heated to a desired temperature for pressing.

By retreating the first handler 85, the glass preform G heated by the glass heating device 83 is placed on the conveyor 84 again, and is moved to the front of the second handler 86 by the conveyance. Here, the second handler 86 is driven, and the glass preform G is transported into the molding chamber 90 via the passage 100. The second handler 86 also transports the pressed glass (hereinafter, referred to as optical glass) from the molding chamber 90 to the heating chamber 80 and returns the glass onto the conveyor 84. Optical glass G returned
Is conveyed by the conveyer 84 through the slow cooling zone 88 toward the unloading section 82 and is gradually cooled. The optical glass G transported to a position below the unloading unit 82 is sent to the unloading unit 82 by a pickup unit (not shown), and is unloaded to the outside.

On the other hand, in the forming chamber 90, a pressing device 91 for pressing the glass preform G preheated in the heating chamber 80 is installed. FIG. 8 shows a sectional view of a molding die in the press device. In substantially the same manner as in the previous embodiment, the molding die 110 includes upper and lower dies 113a and 111b and upper and lower dies 113b and upper and lower sleeves 112a and 112b in upper and lower mother dies 111a and 111b formed in a cylindrical shape. Is done. Opposite surfaces of the upper mold 113a and the lower mold 113b are molding surfaces 114a and 114b designed according to the spherical surface of the optical glass to be molded. The glass preform G supplied by the second handler 86 is disposed between the upper and lower mold surfaces 114a and 114b as shown in the figure, and is pressed by operating the upper mold 113a and the lower mold 113b. . As in the previous embodiment, a mold heating device 92 based on high-frequency induction heating is installed on the outer periphery of the mold 110, whereby the mold before pressing is preheated to a predetermined temperature. An opening / closing door 93 is also installed in the molding chamber 90, from which maintenance or inspection of the press device 91 is enabled.

As in the previous embodiment, an airtight valve 10 is provided on a passage 100 communicating the heating chamber 80 and the press chamber 90.
1 is installed. The configuration, operation, and function of the hermetic valve 101 are the same as those of the previous embodiment, and thus description thereof is omitted here.

In the press molding apparatus 70 having the above configuration,
When it becomes necessary to maintain or check the press device 91 in the molding chamber, the airtight valve 101 is closed and gas exchange between the heating chamber 80 and the molding chamber 90 is prohibited before this. This ensures the airtightness of the heating chamber 80 even when the opening and closing door 93 is opened for maintenance or inspection. Accordingly, it is not necessary to lower the temperature of the glass heating device 83 in the heating chamber 80 at the time of the maintenance or inspection, and it is possible to reduce the time required for lowering and raising the temperature.

The embodiment of the present invention has been described with reference to the drawings. However, it is apparent that the present invention is not limited to the matters described in the above embodiments, and that changes, improvements, and the like can be made based on the description in the claims. For example, the arrangement and specific configuration of each device in the molding chamber and the heating chamber are not limited to those described in the embodiment. Further, in the present invention, the airtight valve may have a structure in which the shield is moved up and down by another method, for example, manually.

[0053]

As described above, according to the present invention, the time required for lowering and raising the temperature in the chamber before and after the maintenance or inspection work of the press forming apparatus can be shortened, so that the press forming productivity can be reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan sectional view of a press forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a molding die and a mold heating device in the press device.

FIG. 3 is a plan view showing a tip end of an arm of a supply handler installed in a heating chamber and a cross-sectional view taken along line AA.

FIG. 4 is a cross-sectional view showing an embodiment of an airtight valve installed on a passage connecting a heating chamber and a molding chamber.

FIG. 5 is a flowchart showing a procedure for forming an optical glass.

FIG. 6 is a flowchart showing a procedure of maintenance or inspection work in the molding chamber.

FIG. 7 is a schematic plan sectional view of a press forming apparatus according to another embodiment of the present invention.

FIG. 8 is a sectional view of a molding die in the press device of FIG.

[Explanation of symbols]

 G Glass preform or optical glass 10 Press molding device 20 Heating chamber 21 Loading unit 22 Glass heating device 23 Supply handler 23a Drive unit 24 Arm 24a, 24b Arm split body 25 Floating dishes 25a, 25b Floating dish split body 26 Receiving part 30 Molding Chamber 31 Unloading unit 32 Unloading handler 32a Drive unit 32b Arm 32c Suction pad 33 Press device 34 Heating device 35 Opening and closing door 35a Seal member 35b Window 40 Passage 41 Airtight valve 42 Cylinder 43 Shield 43a Sealing member 50 Mold 51 Sleeve 53a Upper die 53b Lower die 54 Molding surface 55a Guide pin 55b Hole 56 Induction heating coil 70 Press molding device 80 Heating chamber 81 Carry-in part 82 Carry-out part 83 Glass heating device 84 Conveyor 85 First handler 86 Second Handler 87 preheating zone 88 gradually cooling zone 89 work 90 press chamber 90 forming chamber 91 pressing device 92 type heating device 93 door 100 passage 101 airtight valve 110 mold 111 mold 112 sleeve 113a upper die 113b lower die 114 forming surface

Claims (12)

[Claims] 1. A molding apparatus for molding a glass by pressing a glass material, comprising: an airtight heating chamber which is brought into a non-oxidizing gas atmosphere at the time of press molding; A glass heating means for heating and softening the glass material to a predetermined viscosity, and a first conveying means for conveying the glass material, and the glass in the heating chamber while maintaining a non-oxidizing gas atmosphere in the heating chamber. A carrying means capable of carrying a material, and an airtight molding chamber which is brought into a non-oxidizing gas atmosphere at the time of press molding, wherein at least the inside of the glass material is pressed and a predetermined optical material is pressed. Pressing means provided with a forming die for forming a glass shape, die heating means for heating the forming die to a predetermined temperature, and a second transfer for taking out the pressed glass from the forming die and transferring it A conveying means, a discharge means for discharging the glass outside the molding chamber while maintaining the non-oxidizing gas atmosphere in the molding chamber, and a communication between the heating chamber and the molding chamber; A passage through which the glass material in the heating chamber can be conveyed into the molding chamber by the first conveyance means; and a passage when the glass material in the heating chamber is conveyed into the molding chamber by the first conveyance means. A shutter that is opened to allow the transfer of the glass material through the shutter and closed to disable gas exchange between the heating chamber and the molding chamber when working in the molding chamber, A press forming apparatus for glass, comprising: an opening / closing door provided in the molding chamber, which is opened to allow an operator to access the molding chamber when working in the molding chamber. 2. The glass press forming apparatus according to claim 1, wherein the shutter thermally shuts off the heating chamber and the forming chamber when working in the forming chamber. 3. The glass press forming apparatus according to claim 1, wherein the shutter is a gate valve provided with an airtight member around the shutter. 4. The mold heating means for heating the mold by high frequency induction heating.
A press forming apparatus for glass as described in the above. 5. The glass press forming apparatus according to claim 1, wherein the glass heating means heats the glass material by resistance heating by a resistor. 6. The glass press forming apparatus according to claim 1, wherein the opening / closing door includes a window made of a light-transmitting member through which the inside of the forming chamber can be visually recognized. 7. A heating chamber for heating a glass material supplied from the outside to soften it to a predetermined viscosity, and for pressing said glass material with a heated mold to form a predetermined glass shape. A molding chamber, a shutter for opening and closing a passage through which the glass material can be transferred from the heating chamber to the molding chamber, and an opening / closing door for accessing the molding chamber. Stopping the supply and conveyance of the glass material; closing the shutter to shut off the heating chamber and the molding chamber so that gas cannot be exchanged; and lowering the ambient temperature in the molding chamber. A step of opening the opening / closing door to enable work in the forming chamber. 8. After the operation in the molding chamber is completed, a step of closing the opening / closing door and exchanging gas in the molding chamber with a non-oxidizing gas atmosphere, and a step of heating the molding die to a predetermined temperature. The method according to claim 7, further comprising: a step of opening the shutter; and a step of restarting supply and conveyance of the glass material. 9. The working method in the glass press forming apparatus according to claim 7, wherein the shutter thermally shuts off the heating chamber and the forming chamber when working in the forming chamber. . 10. The method according to claim 7, wherein the forming die is heated by high-frequency induction heating. 11. The glass material is heated by resistance heating by a resistor in the heating chamber.
The method for working in a glass press forming apparatus according to 8, 9, or 10. 12. The molding die according to claim 7, wherein the molding surface is provided with a carbon-based thin film.
The method of working in a glass press forming apparatus according to 1, 12, 13 or 14.