JPS62241832A - Heating apparatus for optical element - Google Patents

Abstract

PURPOSE:To easily impart optimum temperature distribution to a glass gob in a furnace, by forming an operation port nearly at the center of a furnace and placing a cooling member between the operation port and an opening of the furnace and between a heating element and an optical element transfer means. CONSTITUTION:A furnace 22 is provided with a glass gob-introducing opening 26 and a pressed lens-delivery opening 27 at the lower side wall of the front and rear ends 22a, 22b of the furnace and the furnace 22 contains a heating element 29 and a transfer caterpillar 28 for the introduction and delivery of a glass gob 23 and the pressed lens 24 in the furnace chamber 25. The glass gob 23 supported on the caterpillar 28 is transferred by a transfer arm 9 to a forming apparatus 1 having a pair of molds through an operation port 33 formed at the lower middle part of the side surface 22c of the furnace 22. The pressed lens 24 is transferred by a transfer arm 11 into the furnace chamber 25 through the operation port 33. A cooling member 35 is placed between the heating element 29 and the caterpillar 28 and between the operation port 33 and the inner side surface 22d of the furnace 22 having the opening 27 along the transfer direction (the direction of the arrow A) of the caterpillar 28.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heating device for a glass material in an apparatus for manufacturing an optical element obtained by press-molding a glass material softened by heating using a mold.

[Prior art] As a method for forming optical elements such as lenses and prisms without using grinding or polishing, optical elements are formed by heating and softening a glass material and press-molding it using a pair of molds with high surface precision. There are known ways to obtain it.

In the apparatus used in such a method, the heating apparatus for heating and softening the glass material and the molded lens is disclosed in Japanese Patent Application No. 1988-99363 (Method for Conveying Press Gob and Press Lens and its Equipment 21) filed earlier by the applicant. There is a technique disclosed in , and FIG. 7 shows a schematic configuration of the heating device.

This technology consists of a molding device 1 equipped with a pair of molds, etc., a heating furnace 2 that heats a glass material and an annealing furnace 3 that slowly cools a molded lens that has been subjected to compression molding. It consists of

The heating furnace 2 and the slow cooling furnace 3 can each be provided with one or more heaters and one or more thermocouples as necessary to form an appropriate heat distribution, and can be temperature-controlled via a temperature controller. It is equipped with conveyance caterpillars 4.5 for conveying the molded lens.

Further, the heating furnace 2 and the slow cooling furnace 3 are provided with work ports 6 and 7, and the glass material that has been conveyed through the work port 6 and heated to a predetermined temperature in the heating furnace 2 is moved to a drive bag 8. The glass material conveying arm 9 transfers the molded lens to the molding device 1, and the molded lens is transferred to the molding machine 1 through the working lower. Driving bag 'j from 11! The lens is transferred to the lehr 3 by the arm 11 for conveying the lens linked to the lens 11O, and
The structure is such that the material is transported inside and slowly cooled according to a preset thermal history.

[Problems to be Solved by the Invention] The conventional technology described above includes a heating furnace 2 for heating and softening the glass material and an annealing furnace 3 for slowly cooling the molded lens.
Since these are provided individually, there are problems in that the temperature control device for controlling the temperature inside the furnace becomes complicated, the structure of the furnace becomes large, and the molded lens becomes extremely expensive.

Furthermore, there is a problem in that the overall space required for lens molding becomes large.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a small-sized heating device that has both a heating furnace and a slow cooling furnace.

[Means for Solving the Problems] The present invention provides a heating device comprising a furnace body provided with an optical element conveying means and a heating element at both end openings, in which a working opening is formed approximately in the center of the furnace body, and the working opening is A cooling member is provided between the heating element and the one opening, and between the heating element and the conveying means.

[Function] With the above configuration, it is possible to obtain a heating device that has both a heating furnace and a slow cooling furnace.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

(First Embodiment) FIG. 1 is a sectional view showing a first embodiment of an optical element heating device 21 according to the present invention.

In the figure, 22 is a furnace body made of a refractory material, and this furnace body 22 is used to heat a glass material 23 and slowly cool an optical element (pressed lens) 24 after molding. A furnace chamber 25 is formed. The furnace body 22 is
Side part 22a.

22b (on the left and right sides in the figure) are formed with an opening 26 for carrying in the glass material 23 and an opening 27 for carrying out the press lens 24, respectively. Carrying them into the furnace chamber 25 and carrying them out from the furnace chamber 25 is carried out by a transport caterpillar 28 that supports and transports them.
The configuration is performed via the .

Further, the furnace body 22 serves as the transport direction of the glass material 23 and the like.
At the lower center of the side surface 22c, a glass material 23 supported on a conveying caterpillar 28 is transferred via a conveying arm 9 (see FIG. 7) to a molding fit having a pair of molds (see FIG. 7). In addition, the press lens 24 is transferred to the transport arm 11.
A working opening 33 is formed so that the material can be transferred into the furnace chamber 25 through the pipe (see FIG. 7). A heating element 29 for heating the glass material 23 and slowly cooling the press lens 24 is provided in the upper part of the furnace chamber 25, and a thermocouple 30 is also provided so that the temperature inside the furnace chamber 25 can be controlled by a temperature controller 31. It has become.

Furthermore, the cooling member 35 is transported with the heating element 29 from the opening 33 to the inner surface 22d of the furnace body 22 provided with the transport opening 27 in the transport direction of the heat transport caterpillar 28 (in the direction of arrow A in the figure). The part provided between the caterpillars 28 and where the cooling member 35 is not provided is a heating furnace part,
The furnace body 22 is constructed by using the portion where the cooling member 35 is provided as a slow cooling furnace section.

FIG. 2 is a sectional view showing the cooling member 35, which consists of a stainless steel plate (SUS316 stainless steel plate) 3.
6 is provided with a heat insulating member 37.

In this heating bag 2121, the heating element 29 is
0W infrared heater, optical glass SF8 (transition point 4
A plano-convex lens having a temperature of 43° C. and a softening point of 567° C. was molded. In such a case, the thickness of the slow cooling member 35 is adjusted and the furnace body 2
As shown in FIG. 3, the temperature inside the furnace chamber 25 of No. 2 rises from the carrying-in opening 26, and reaches 570°C at the rear end of the heating furnace, 400°C at the front end of the slow-cooling furnace, and 200°C at the carrying-out opening 27. We were able to obtain an indoor temperature distribution. As a result, the molded press lens 24 was free of distortion and could be used as an optical disk lens.

Note that the shape, size, etc. of the cooling member can be changed to form a specific heat distribution within the furnace chamber 25 depending on the type, size, shape, etc. of the glass material and press lens. , an example is shown in FIGS. 4 and 5.

In FIG. 4, a cooling member 35 is formed by changing the thickness of the heat insulating member 27 and making the side of the carrying-out opening 27 thicker. or,
In FIG. 5, the widths of the heat insulating member 37 and the stainless steel plate 36 are changed, and the cooling member 35 is formed by making the width on the side of the carrying-out opening 27 wider.

Furthermore, although such a cooling member 35 is not shown, it can be implemented simply by using only a stainless steel plate as a shielding plate for heat from the heating element 29.

According to this embodiment, by providing a simple cooling member, it is possible to form a heating furnace section for glass material and a slow cooling furnace section for molded lenses in the same furnace, and it is also possible to easily obtain the optimum indoor temperature distribution for lens molding. can.

(Second Embodiment) FIG. 6 shows a second embodiment of the heating type optical element according to the present invention, showing only the cooling member in the first embodiment, and the other configurations are the same as in the first embodiment. Therefore, it will be omitted.

The cooling member 40 in this embodiment includes a stainless steel tube 42 with a hollow part 41 inside, and a hollow part 41 in one side 43.
It is composed of a thin tube 44 that communicates with the. This thin tube 4
4 is connected to a fluid supply device (not shown), and the cooling member 40 is configured such that a fluid 45 such as water, compressed air, inert gas, etc. can flow through a hollow portion 41 at an arbitrary pressure and flow rate. .

According to this device, by supplying the fluid 45 to the hollow portion 41 from the direction indicated by the arrow through the thin tube 44, the inside of the heating furnace can be cooled to a desired temperature to form a slow cooling furnace.

In this embodiment, 1.5 liters of compressed air is supplied into the hollow part 41.
kg/cm2. 31/min.

It was possible to obtain the same temperature distribution in the furnace as in the first example.

According to this embodiment, it is possible to achieve the same effects as in the first embodiment, and even if there are changes in the glass material, shape, size, etc., it is possible to easily obtain the necessary temperature distribution in the furnace. It is something.

Incidentally, the heating device in the first embodiment and the second embodiment is as follows:
Although shown as a final heating section, if necessary, a final heating section can be newly provided between the work opening and the molding device, and the heating device in this embodiment can be implemented as a configuration that can be used as a preheating device.

[Effects of the Invention] As described below, according to the present invention, it is possible to obtain a heating device for a lens material that includes a heating furnace part in the same furnace body, and to control the temperature inside the furnace in a compact and simple manner. It can be used as a temperature control station.

It is possible to obtain molded lenses of good quality. Furthermore, since the glass material can be supplied to the press molding device for optical materials and the molded lens can be discharged in the same direction, the glass material can be supplied to the molding device and the molded lens can be discharged from multiple directions, reducing takt time. Can be shortened.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the device according to the present invention;
Figure 2 is a cross-sectional view of the cooling member, Figure 3 is a graph showing the temperature distribution inside the furnace, Figure 4 is a cross-sectional view of other cooling members, and Figure 5
This figure is a perspective view of a cooling member different from that shown in FIG. 4, and FIG. 6 is a sectional view of the cooling member in a second embodiment of the apparatus according to the present invention. 21... Optical element heating device 22... Furnace body 25... Furnace chamber 26... Opening for carrying in 27... Opening for carrying out 28... Caterpillars for conveyance 29... 41 Holiday 30 ... Thermocouple 31 ... Temperature controller 33 ... Working port 35.40 ... Cooling member 36 ... Stainless steel plate 41 ... Hollow part 42 ... Stainless steel tube 44 ... Thin tube 45 ... ...Fluid Figure 7 Figure 3 Figure 5 Figure 4 b Figure 6 Procedure correction teeth (method) % formula % 1. Indication of the case 1985 Patent Application No. 80864 2. Name of the invention Optical element Heating device 3, relationship to the amended person case Patent applicant address 2-43-2 Hatagaya, Shibuya-ku, Tokyo Name (037) Olympus Optical Industry Co., Ltd. Representative Toshibe Shimoyama 4, Agent 1988 June 241 Dispatch 8, column for a brief explanation of the drawing of the detailed description subject to amendment

Claims (1)

[Claims] In a heating device consisting of a furnace body having openings formed at both ends and provided with an optical element conveying means and a heating element, a working opening is formed approximately in the center of the furnace body, and a space between the working opening and the one opening is provided. A heating device for an optical element, further comprising: a cooling member provided between the heating element and the conveyance means.