JPH03187931A - Press-forming apparatus for glass - Google Patents

Abstract

PURPOSE:To save energy consumption by selecting a path extending from an inert gas supplying source through a closed space to the outer atmosphere until the air in the closed space is practically substituted with hot inert gas and selecting a circulation path after the substitution with the hot inert gas. CONSTITUTION:When the oxygen concentration in a molding chamber 5 is decreased below a level not to cause the deterioration of the mold and the glass material 17, a change-over valve 14 is turned 90 deg. clockwise and a change- over valve 15 is turned 90 deg. anticlockwise. After the above change-over procedure, the inert gas in the molding chamber 5 is passed through a feed pump 13, a circulation path 16 and a heater 12 and circulated as hot inert gas to heat a glass material 17 to a temperature above the softening point. The consumption of the inert gas and the energy for heating the gas can be saved by the above process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a press molding apparatus for glass, and particularly to a press molding apparatus suitably used for molding optical parts such as lenses.

[Conventional technology]

In press molding of glass lenses and the like, in order to prevent deterioration of molds and glass materials heated to high temperatures due to oxygen, press molding is performed by heating under an inert gas atmosphere. It accommodates a press molding mold filled with glass material to form a sealed space, allows heated inert gas to flow through the sealed space, and pressurizes the mold in the sealed space. This can be carried out using a press molding apparatus using a molding chamber structure that can be used.

[Problem to be solved by the invention]

When performing glass press molding using a press molding device such as the one described above, in order to press smoothly and accurately to obtain a good molded product and to minimize mold deterioration, it is necessary to
A heated inert gas must be circulated through the closed molding chamber until the pressing is completed. Therefore, the conventional press molding apparatus has a problem in that it consumes a large amount of inert gas such as N2 and energy for heating it.

The present invention has been made to solve this problem, and aims to provide a glass press molding device that can reduce the consumption of inert gas and heating energy, and can easily automate the process. .

[Means to solve the problem]

The present invention includes a gas supply path for feeding an inert gas from an inert gas supply source through a heating device to an enclosing wall that forms a sealed space by accommodating a press molding die into which a glass material is charged, and a gas supply path for supplying inert gas from an inert gas supply source through a heating device. In a glass press molding apparatus that uses a molding chamber structure that is connected to a gas exhaust path that discharges the gas to the outside through a pump and that can heat and press the mold in a closed space, the gas supply path is inert. The path from the gas supply source to the heating device and the gas exhaust path from the pump to the outside, from the inert gas supply source to the outside via the closed space, and the pump from the closed space.

The glass press molding apparatus is characterized in that the heating device is selectively connected to the circulation path returning to the closed space through the heating device, and this configuration achieves the above object.

[Effect]

That is, in the press molding apparatus of the present invention, until air is replaced with heated inert gas in the closed space housing the press mold into which the glass material is charged, air is supplied from the inert gas supply source through the closed space. It is possible to select a route leading to the outside, and then select a circulation route after the sealed space has been substantially replaced with heated inert gas, saving consumption of inert gas and the energy used to heat it. Moreover, the hot pressing process can be easily automated by performing the above-mentioned selection change based on the oxygen concentration information in the closed space or the elapsed time information from the timer.

〔Example〕

The present invention will be explained below using illustrated examples.

FIG. 1 is a schematic configuration diagram showing an example of the press molding apparatus of the present invention, and in the figure, l denotes an upward fixing surface, 3 2 a downward fixing surface, 3 an upper molding chamber structure fixed to the downward fixing surface 2, 4 is an annular horizontal wall portion 4a and a mirror horizontal wall portion 4
b, the lower surface around the hole of the annular horizontal wall portion 4a and the mirror horizontal wall portion 4b
A bellows 4C made of nickel alloy or the like is joined to the peripheral edge of the upper surface and connects the two, and a mirror horizontal wall in which a mold can be placed on the tip surface passing through a hole in the annular horizontal wall 4a. The lower molding chamber structure consists of a pressurizing body part 4d integrally provided with part 4b, and 5 is raised by being pushed against the lower surface of mirror horizontal wall part 4b by the head 7a of plunger 7 which is moved up and down by a hydraulic piston or the like. The annular horizontal wall portion 4 of the lower molding chamber structure 4
8 and 9 are gas cylinders provided on the ceiling wall of the upper molding chamber structure 3; The introduction passage and the gas discharge passage, IO, are used to efficiently and uniformly transfer the high temperature inert gas sent into the molding chamber 5 by the gas introduction passage 8 to the mold placed on the pressurizing body 4d of the lower molding chamber structure 4. These are guide vanes attached to the inner surface of the ceiling wall of the upper molding chamber structure 3 that guide the mold to be heated and guide the gas that heated the mold to the suction port of the gas discharge passage 9.

11 is an inert gas supply source such as N2, 12 is a heating device, 1
3 is an air supply pump; 14 is an opening/closing passage from the inert gas supply source 11 to the heating device 12 and a circuit from the circulation path 16 to the heating device 12;
15 is a switching valve that switches between opening and closing a passage from the air supply pump 13 to the outside and opening and closing a passage from the air supply pump 13 to the circulation path 16. It is.

Press molding of glass in this press molding apparatus is performed as follows.

When the plunger 7 is lowered and the lower surface of the annular horizontal wall 4a of the lower molding chamber structure 4 rests on the upward fixed surface l, it is stopped, and in this state, the pressurizing body 4 with the molding chamber 5 opened
Upper and lower molds 18 and 19 with glass material 17 poured onto d
A mold consisting of is placed.

Next, the plunger 7 is raised so that the upper surface of the annular horizontal wall portion 4a of the lower molding chamber structure 4 comes into pressure contact with the lower end of the side wall of the upper molding chamber structure 3, and the molding chamber 5 as a sealed space is formed. The molding chamber 5 is evacuated. In this case, the switching valve 15 is in the state where the passage to the circulation path 16 is closed between the illustrated discharge passage to the outside, and the switching valve 14 is in the state where the passage from the illustrated inert gas supply source 11 to the heating device 12 is open and the circulation path 16 is closed. The path from the circulation path 16 to the heating device 12 is closed, or the path from the inert gas supply source 11 rotated 90° clockwise from the illustrated state to the heating device 12 is closed, and the path from the circulation path 16 to the heating device 12 is opened. state. Among these, setting the switching valve 14 to the state shown in the figure means that the glass material I7 is kept in the molding chamber 5 even during exhaust.
This is to flow a high temperature inert gas having a softening point or higher, and to turn the switching valve 14 clockwise by 90 degrees is to evacuate the molding chamber 5.

In either case, when the oxygen concentration in the molding chamber 5 falls below a concentration that does not deteriorate the mold or the glass material 17, the switching valve 14 is rotated 90 degrees clockwise from the illustrated state, and the switching valve 15 from the state shown in the figure to the state rotated 90 degrees counterclockwise. This switching point is given by the information from the oxygen concentration sensor or the elapsed time information from the start point of exhaust and high temperature inert gas feeding. After this switching point, the inert gas in the molding chamber 5 is transferred to the air supply pump 13° circulation path 16. The hot inert gas is circulated through the heating device 12 to heat the glass material 17 above its softening point. This saves the consumption of inert gas and the energy for heating it.

In the illustrated apparatus, the steps up to this point are performed while the mold and the pressurizing body portion 4d of the lower molding chamber structure 4 are at a height that does not obstruct the flow of the high-temperature inert gas. Then, when the temperature of the glass material 17 reaches the softening point or higher, the plunger 7 is further raised. As a result, the bellows 4c is compressed, and the upper surface of the upper mold I8 comes into contact with the ceiling wall surface of the upper molding chamber structure 3.
Press molding of the glass material 17 is performed.

When press forming is completed by raising the plunger 7 to a predetermined height or raising the reaction force to the plunger 7 to a predetermined magnitude, the plunger 7 is lowered, the heating device 12 is stopped, and the switching valve 14 and 15 is switched to the state shown, and the mold etc. are cooled with inert gas. Then, before and after the annular horizontal wall portion 4a of the lower molding chamber structure 4 separates from the lower surface of the side wall of the upper molding chamber structure 3, the switching valve 14 is switched from the illustrated state to a state rotated 90' clockwise, and the air supply pump 13 is turned on. Stop. Then, by further lowering the plunger 7 and stopping it when the lower surface of the annular horizontal wall portion 4a comes to rest on the upward fixing surface 1, the mold for which press molding has been completed is taken out, and the mold for the next press molding is inserted. , the same press molding process as before can be repeated.

The press molding apparatus of the present invention is not limited to the above-mentioned example, and the upper and lower molding chamber structures are connected by a tightening means, and the plunger penetrates the ceiling wall or floor wall of the molding chamber and opposes the floor of the molding chamber. Even if the mold is pressed between a wall or a ceiling wall, the gas introduction passage and the gas exhaust passage are provided separately on the ceiling wall and floor wall of the molding room, or are provided so as to penetrate the side wall. Alternatively, an on-off valve may be provided between the molding chamber and the heating device or between the molding chamber and the air pump. Furthermore, the air supply pump is not limited to one that can evacuate the molding chamber, but may also be one that equalizes the pressure on the suction side and the air supply side when stopped.

When such an air supply pump is used, after press molding is completed and the temperature of the mold, etc. falls to a temperature that is less susceptible to deterioration due to oxygen, the annular horizontal wall portion 4a is moved from the lower surface of the side wall of the upper molding chamber structure 3. Even before you leave, the switching valve 14
is rotated 90° clockwise from the illustrated state, the air pump 13 is stopped, and the lower molding chamber structure 4 can be lowered by lowering the plunger 7.

〔Effect of the invention〕

According to the press molding apparatus of the present invention, glass can be press molded without deteriorating the mold or glass due to oxygen and while saving consumption of inert gas and energy for heating it. You can get the effect that you can.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the press molding apparatus of the present invention. ■...Upward fixed surface 2...Downward fixed surface 3...
- Upper molding chamber structure 4... Lower molding chamber structure 5... Molding chamber 6... Sealing material 7... Plunger 9... Gas discharge passage 11... Inert gas supply source 12... Heating device 14.15...Switching valve 17...Glass material 19...Lower die 8...Gas introduction passage lO...Guide vane 13...Air supply pump 16...Circulation path 18...・Upper mold

Claims (1)

[Claims] A gas supply path is provided for supplying inert gas from an inert gas supply source through a heating device to an enclosing wall that accommodates a press-molding mold filled with glass material to form a closed space, and a gas supply path for supplying inert gas from an inert gas supply source through a heating device to the surrounding wall that accommodates a press molding mold filled with glass material, and a gas supply path for supplying inert gas from an inert gas supply source through a heating device to the outside through a pump. In a glass press molding apparatus using a molding chamber structure that is connected to a gas exhaust path for discharging gas to the gas supply path and capable of heating and pressing the mold in a closed space, from the inert gas supply source of the gas supply path between the heating device and the gas exhaust path from the pump to the outside.
A glass press forming apparatus characterized in that a path leading from an inert gas supply source to the outside via a closed space and a circulation path leading from the closed space to the closed space via a pump and a heating device are selectively connected.