JPH03232727A - Production unit for glass optical part - Google Patents

Abstract

PURPOSE:To enable continuous production of the subject optical part while forcing molten glass to flow down using a simple-constitution apparatus by making plural press units having mold members mutually approaching and separating on a horizontal shaft hold on a rotary holder. CONSTITUTION:In the case cylinders 29 and 30 are at retreated positions while a pair of mold members 16 and 17 are in an open state as shown in (a) of the figure, molten glass is forced to flow down through a nozzle. When passage of the molten glass between the mold members 16 and 17 is detected, the cylinders 29 and 30 go ahead. And the mold members 16 and 17 approach to a prescribed distance as shown in (b) of the figure and pressing is carried out to cut the molten glass at a suitable timing. A holding plate 13 is then rotated by a motor 14 and the mold members 16 and 17 are moved to a specified position. The molding is then cooled while keeping the pressing state.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an apparatus for manufacturing glass optical components, and in particular, the present invention relates to an apparatus for manufacturing glass optical components, and in particular, it continuously produces optical components by pressing mold members from both sides of glass in a molten state while flowing down. The present invention relates to a device for obtaining parts.

[Prior Art and Problems to be Solved by the Invention] Methods for obtaining optical components from glass materials by press molding include the so-called reheat press method and the direct press method.

In the above-mentioned reheat press method, a glass blank having a shape similar to that of the final molded product is first formed, then the blank is placed in a molding device, heated and pressurized, and then formed by the mold members of the molding device. Obtain a final molded product that corresponds to the shape of the cavity.

In the above-mentioned direct press method, molten glass is introduced into a mold device and pressurized to directly obtain a final molded product corresponding to the shape of a cavity formed by a mold member of the mold device.

By the way, since it is preferable that the glass blank used in the reheat pressing method has a certain degree of shape accuracy and surface accuracy, the glass blank may be ground and polished to obtain a blank with a predetermined accuracy. However, since this requires time and effort for grinding and polishing, the above-mentioned direct press method is sometimes used to manufacture the above-mentioned glass blank.

As a direct press method, for example, Japanese Patent Application Laid-Open No. 63-2
As described in Japanese Patent Publication No. 48727 and Japanese Unexamined Patent Publication No. 1-133948, while the molten glass is flowing down from a nozzle, a pair of mold members for forming the glass are horizontally opposed from both sides of the molten glass. There is a method in which a molded product of a predetermined shape is obtained by sandwiching the glass and cooling and hardening the glass in the cavity thus formed. In this method, a ring-shaped cutting member is placed around the outer periphery of the optical surface molding surface of one mold member, and is moved forward at the same time as or after the mold member advances to cut and remove the protruding glass. An optical component having a desired shape is formed. According to this method, an optical component can be obtained without leaving cutting marks of flowing molten glass on the optical surface, which is preferable.

However, in conventional apparatuses using this press method, press forming is performed using a press device fixed directly below the glass outflow nozzle, so there is a limit to the improvement in press efficiency. That is, the molten glass supply capacity per unit time generally far exceeds the press capacity of the press machine per unit time, and as a result, there is a disadvantage that the glass supply speed must be kept low to match the press capacity of the press machine. there were.

Therefore, in order to improve the press efficiency, it is desired to increase the press capacity. For this reason, it has been proposed in the past, for example, to use a plurality of press devices and alternately supply the glass from the glass outflow nozzles.

However, in this method, the press equipment itself is moved in order to supply molten glass alternately, so this movement takes time, there is a limit to the improvement of press efficiency, and there is a risk that the maximum capacity for supplying molten glass cannot be adequately met. There is. Further, according to this method, since a plurality of press devices are used, there is a problem that the installation space becomes large.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an optical component manufacturing apparatus using a direct press method, which can obtain high press efficiency with a simple apparatus configuration.

[Means for Solving the Problems] According to the present invention, the above object is achieved by: a press comprising two forming mold members arranged opposite each other on a horizontal axis so as to be close to each other and separated from each other to form a pair; A plurality of sets of units are provided, and each press unit is provided with a first driving means for moving two mold members closer to each other and separated from each other, and the plurality of sets of press units are held by a press unit holder. The holding body is rotatably or rotatably supported around a central horizontal axis equidistant from the plurality of sets of press units, and means for driving the rotation or rotation of the holding body is provided. and
Furthermore, a molten glass outflow nozzle is disposed above a first specific position in the movement path of rotation or rotation of the plurality of press units about the central horizontal axis, and a molten glass outflow nozzle is disposed below the nozzle. There is a way to disconnect! A manufacturing device for glass optical components, characterized in that:

is provided.

In the present invention, three or more sets of the above-mentioned press units are provided, and for each press unit, the pressing process is performed at a first specific position on the above-mentioned rotational or rotational movement path, and the pressing process is performed at a second specific position on the above-mentioned movement path. There is a configuration in which a cooling process is performed at a third specific position on the movement path, and a molded glass optical component removal process is performed at a third specific position on the movement path.

In the present invention, there is a mode in which the first specific position is set between an uppermost position in the movement path of rotation or rotation of the plurality of press units and a position rotated by 90 degrees from the uppermost position. .

In the present invention, in each of the press units, a second drive means is provided, independently of the first drive means, for moving one of the two mold members of the pair toward and away from the other. There is a form in which there is.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view showing a schematic configuration of an embodiment of an optical element manufacturing apparatus according to the present invention.

In FIG. 1, reference numeral 1.4 denotes a mold set including a pair of molding mold members arranged opposite each other so as to be close to and separated from each other on the horizontal axis r. Each mold set includes drive means for moving the mold member in the direction of the horizontal axis r1. The mold set 1.4 constitutes a first press unit. The illustrated position B of this press unit is a first specific position, and the pressing process is performed here.

2.5 is a set of mold sets equivalent to the set of mold sets 1 and 4 described above, and the set of mold sets 2 and 5 constitutes a second set of press units. Here, the two forming mold members forming a pair are arranged opposite to each other on the horizontal axis r2 so as to be able to approach and separate from each other. The illustrated position C of this press unit is a second specific position, where the cooling process is performed.

3.6 is a set of mold sets equivalent to the set of mold sets 1 and 4 described above, and the 3rd set of press units is constituted by the 60 sets of mold sets 3. Here, the two forming mold members forming a pair are arranged opposite to each other on the horizontal axis r so as to be able to approach and separate from each other. The illustrated position D of this press unit,
is the third specific position, where the molded glass optical component removal process is performed.

The mold sets 1, 2.3 and the mold set 4°5.6 are each held by a holding plate 13. These two holding plates have three rods 12 parallel to each other.
, which constitutes a press unit holder. And each of the above-mentioned holding plates 13
are each supported by a support member 15 so as to be rotatable in the E direction around the central horizontal axis R. 14 is a motor for driving this rotation. The above three horizontal axes r+,
rx and rs are equidistant from the central horizontal axis R, and are arranged at positions rotated by 120 degrees from each other around the central horizontal axis.

Further, 7 is a molten glass outflow nozzle connected to a glass melting device (not shown), and 8 is molten glass flowing out from the nozzle. Moreover, 10 is a shear for cutting the above-mentioned molten outflow glass immediately below the above-mentioned nozzle 7.

9 is a molded glass optical component, and 11 is a shooter for recovering the molded glass optical component.

FIG. 2 is a sectional view showing a more detailed mechanism of the apparatus of the above embodiment. In this figure, two sets of press units in different states (11 openings) are shown.

In FIG. 2, reference numerals 12, 13, 14, and 15 indicate the same members as in FIG. 1 above.

A shows the press unit in the first state, and mouth shows the press unit in the second state. All of the three sets of press units described above can take these states.

16 is a first mold member, and 20 is a support rod thereof. The support rod is supported by a bearing 25 and is moved horizontally by an auxiliary cylinder 28. The auxiliary cylinder is mounted and fixed to member 24. A ring member 18 is disposed around the outer periphery of the first mold member 16, and the ring member is supported by a support member 22, which is fixed to the mounting member 24. The mounting member is moved horizontally by a main cylinder 30, which is fixed to the holding plate 13. Reference numeral 26 denotes a bearing for the support member 22, and the bearing is attached to the rod 12.

On the other hand, 17 is a second mold member, and 21 is a support rod thereof. The support rod is attached and fixed to the member 23. A ring member 19 is arranged around the outer periphery of the second mold member 17, and the ring member is fixed to the mounting member 23. The mounting member is moved horizontally by a main cylinder 29, which is fixed to the holding plate 13. Reference numeral 27 designates a bearing for the mounting member 23, which is attached to the rod 1.
It is attached to 2.

The main cylinders 29, 30 constitute the first drive means, and the auxiliary cylinder 28 constitutes the second drive means.

Although not shown, each mold member 16, 17 includes a heater and a thermocouple for temperature measurement.

Using these, each mold member 16 is controlled by a control device (not shown).
．． 17 temperature controls are performed.

Next, the operation of the apparatus of this embodiment will be explained.

First, at the first specific position B in FIG. 1, as shown in A in FIG.
are all in the retracted position, and the pair of mold members 16 and 17 are in an open state.

In this state, molten glass 8 is caused to flow down from nozzle 7.

Detecting the glass passing between the mold members 16 and 17,
The cylinders 29, 30 are advanced, and the mold members 16, 17 are brought close to a predetermined distance, as shown by the opening in FIG. 2, to perform pressing. In order to obtain a molded product with a predetermined thickness, the stroke of each cylinder can be limited using an appropriate stopper (not shown).

Then, the molten glass 8 is cut by the shear 10 at an appropriate timing.

Next, the motor 14 moves the holding plate 13 once in the E direction.
Rotate 20 degrees and move the mold members 16 and 17 to the position shown in Figure 1 above.
to a specific position C. Here, the molded product is cooled while maintaining the pressed state. Incidentally, by appropriately operating the auxiliary cylinder 28 in this process, it is possible to prevent sink marks from occurring in the molded product.

Next, the motor 14 moves the holding plate 13 once in the E direction.
Rotate 20 degrees and move the mold members 16 and 17 to the position shown in Figure 1 above.
to a specific position. And cylinder 2
8 is released and the cylinders 29 and 30 are retracted to the state shown in FIG. 2A. Here, the protruding amounts of the tips of the rings 18 and 19 from the mold member surface are made different, for example, by making the protruding amount of the left ring 18 thicker, the molded product will adhere to the left mold set. let

Next, the auxiliary cylinder 28 is advanced sufficiently to project the molded product 9 and drop it onto the shooter 1l. In this manner, the auxiliary cylinder 28 performs the two functions of preventing sink marks during the cooling process and ejecting the molded product during the unloading process.

In the taking-out step, after taking out the molded product, the surfaces of the mold members 16 and 17 can be subjected to adhesive leaning by air blowing or the like.

In this embodiment, when the first set of press units is at the first specific position B and performing the pressing process, the second set of press units is at the second specific position C. , the third set of press units
The second and third sets of press units execute the cooling process and the molded glass optical component removal process, respectively.

When the second set of press units is at the first position B and the third set of press units is at the first position B.
The same is true when it is in .

Therefore, in this embodiment, three sets of press units simultaneously perform three types of processes in parallel, and these three sets of press units are moved simultaneously, so there is no need to slow down the flow rate of the molten glass. In addition, the press cycle can be sufficiently accelerated.

Next, the arrangement of the molten glass outflow nozzle 7 in this embodiment will be explained.

FIG. 3 is a diagram showing the arrangement of the molten glass outflow nozzle, and is a diagram seen from direction A in FIG. 1 above.

First of all, from the viewpoint of effective use of the glass and maintenance of molding conditions, it is preferable to arrange the nozzle 7 as close as possible to the mold member at the position where the pressing process is performed, as long as it does not interfere with the movement of the mold set. In this respect, the uppermost mold member position F in FIG. 3 is optimal, with the nozzle at position 7f. Next, since the glass flows down from the nozzle continuously (not intermittently), it is preferable to withdraw the mold member from the nozzle 7 as soon as possible after the pressing process is completed. In this respect, the rightmost mold member position H in FIG. 3, where the relative velocity (especially downward velocity) to the falling molten glass is maximum, is optimal, and at this time the nozzle is at 7.
It is located at h position.

As mentioned above, the above two conditions are contradictory, and therefore, the mold member position where the pressing process is actually performed is a position on the way from the above-mentioned position F to H in FIG. 3, for example, G.
It is preferable that At this time, the nozzle is at the 7g position.

Next, the results of specifically manufacturing a glass optical component using the above-mentioned example apparatus will be shown below.

11 On skin: Optical glass SF8 (Tg=443℃, specific gravity 4゜22)
Using, outer diameter 20 mm, center wall thickness 2.7 mm, edge thickness 1.29 mm, radius of curvature R, = 20 mm, radius of curvature R*
A reheat press preform (lens blank) having a convex meniscus shape of 40 mm was molded.

The mold members 16 and 17 were made of a nickel-based heat-resistant alloy and had a molding surface polished to an optical mirror surface. The ring members 18 and 19 were made of heat-resistant steel, and the amount of protrusion from the molding surface of the mold member was 0.5 mm and 0.3 mm, respectively.

The viscosity of the molten glass flowing down from the nozzle 7 was set to 1046 bores (temperature 815±5°C), and the temperature of the mold members 16 and 17 was controlled at 400°C.

The working pressure of the main cylinders 30 and 29 is 150, respectively.
Kg and 300 Kg, and the operating speed of these cylinders was 200 mm/sec. Further, the operating pressure of the auxiliary cylinder 28 was set to 100 kg, and the operating speed of the cylinder was set to the minimum within the operable range.

The rotation speed when the holding plate 13 was rotated in the E direction by the motor 14 was set to 60 rpm.

In the pressing process, the molten glass 8 was allowed to flow down for about 4 seconds, and the glass was pressed and cut using the shear 10.

Thereafter, the holding plate 13 was rotated 120 degrees, and cooling was performed for about 4 seconds while operating the auxiliary cylinder 28 in the cooling process.

Thereafter, the holding plate 13 is rotated 120 degrees, and the cooling state is maintained for about 2.5 seconds in the removal process, so that the temperature of the molded product 9 becomes almost equal to the mold member temperature, and then the molded product is heated for about 1 second. I took it out. At the time of taking out, the molded product 9 was held in the mold set on the side of the ring member 18 having a large protrusion amount, and was ejected by the advancement of the auxiliary cylinder 28. Immediately thereafter, the surface of the mold member was cleaned by air blowing for about 0.5 seconds.

The thus obtained molded products 9 all had variations within ±0.01 mm with respect to the target center thickness of 2.7 mm, and there were no harmful surface defects on both optical faces and sink marks were within 1 Oum. Therefore, it could be sufficiently used as a preform for reheat press, and furthermore, it could be sufficiently used as an optical lens that does not require much precision.

The molded product 9 obtained as described above has a protruding part around the main part of the optical component, and the protruding part may be removed by an appropriate method and then reheat pressed. Alternatively, heat pressing may be performed as is, and then core removal may be performed.

The present invention is not limited to the above embodiments, and various modifications are possible.

For example, when manufacturing a molded product that does not require very high precision, the number of press units may be two sets (in this case, the press unit holder should not rotate in one direction (the angle may be reversed as appropriate). This makes various wiring and piping easier.

In addition, when manufacturing molded products that require high precision or have a large volume or wall thickness, a longer cooling time is required, but in this case it is recommended to extend the cooling time by using four or more press units. I can do it.

When high surface precision is required, the temperature of the mold member is not kept at a constant value, but is maintained at a temperature higher than the Tg point before pressing, and lowered below the Tg point after pressing to minimize the temperature difference with the glass. be able to.

Furthermore, when manufacturing multiple types of optical components of the same glass type with approximately the same capacity, press units of different types can be attached to the apparatus and molding can be performed in parallel.

[Effects of the Invention] As explained above, according to the present invention, a plurality of press units are held by a press unit holder, and the holder is moved around a central horizontal axis equidistant from the plurality of press units. The molten glass is supported rotatably or rotatably on the press unit, and the molten glass is pressed by flowing out from above a specific position on the movement path of the press unit, so multiple press units perform their respective processes simultaneously, and multiple sets of Since the press units are moved at the same time, the press cycle can be sufficiently accelerated without adjusting the flow rate of the molten glass, and high press efficiency can be obtained with a simple device configuration.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing a schematic configuration of an embodiment of an optical element manufacturing apparatus according to the present invention. FIG. 2 is a sectional view showing a more detailed mechanism of the apparatus of the above embodiment. FIG. 3 is a diagram showing the arrangement of molten glass outflow nozzles. 2.3, 4, 5.6: Mold set, molten glass outflow nozzle, molten glass, molded glass optical parts, : Shear 13: Holding plate, : Motor, 17: Molding mold member, 19: Ring member, auxiliary cylinder , 30: Main cylinder. 1゜7: 8: 9: 0 4 16゜18゜28: 29゜

Claims (4)

[Claims] (1) It is equipped with a plurality of press units including two forming mold members arranged in pairs so as to be close to each other and separated from each other on a horizontal axis, and each press unit includes two forming mold members. A first driving means is provided for moving the press units toward and away from each other, and the plurality of press units are held by a press unit holder, the holder having a central horizontal axis equidistant from the plurality of press units. is rotatably or rotatably supported around the
Means for driving the rotation or rotation of the holder is provided, and means is provided for driving the rotation or rotation of the plurality of press units, and the molten glass is positioned above a first specific position in the movement path of the rotation or rotation of the plurality of press units about the central horizontal axis. 1. An apparatus for producing glass optical components, characterized in that an outflow nozzle is arranged, and a means for cutting outflowing molten glass is arranged below the nozzle. (2) Three or more sets of the above-mentioned press units are provided, and for each press unit, the pressing process is performed at a first specific position on the above-mentioned rotational or rotational movement path, and cooling is performed at a second specific position on the above-mentioned movement path. 2. The glass optical component manufacturing apparatus according to claim 1, wherein the glass optical component manufacturing apparatus performs the molded glass optical component removal step at a third specific position on the movement route. (3) The first specific position is set between an uppermost position in the rotational or rotational movement path of the plurality of press units and a position rotated by an angle of 90 degrees from the uppermost position. A manufacturing apparatus for the glass optical component described above. (4) In each of the press units, a second drive means is provided, independent of the first drive means, for moving one of the two forming mold members of the pair toward and away from the other; The apparatus for manufacturing a glass optical component according to claim 1.