JPH01201038A - Optical element manufacturing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to press molding of optical elements, and is capable of continuously manufacturing high-precision optical surfaces f-, which require post-processing after press molding. The present invention relates to an optical element mounting device.

(Prior art) In recent years, optical elements with high-precision optical surfaces that do not require post-processing such as grinding and polishing have been developed by press-molding optical element materials placed in molds with a predetermined surface accuracy. A method for molding has been developed.

An optical element molding method using such a press molding method and suitable for continuous molding of optical elements is disclosed in, for example, Japanese Patent Laid-Open No. 59
As shown in Japanese Patent Application Laid-Open No. 150728 or JP-A No. 61-26528, a material for molding an optical element is housed and placed in a mold, and the material is held in the mold while being connected to a heating section and molding. The molding material is sequentially introduced into a molding chamber that has a molding section and a cooling section, and the molding material and the molding die are heated and softened in the heating section to a temperature that can be molded, and then pressed in the molding section, and then pressed in the cooling section. This process includes the steps of cooling the molding material until it reaches a glass transition point while maintaining the current state of the mold, and then removing the molded product from the mold.

(Problems to be Solved by the Invention) However, during such a process, during the process in which the material for molding the element is heated to a temperature at which it can be molded to 0T,
The molding material is in contact with the surface of the mold within the mold, or
Or, because they are in close proximity, there is a problem in that the molding material reacts with the surface of the mold and the surface of the mold is attacked. In particular, when the molding material for an optical element is a lead-containing glass material, even if the distance between the glass material and the mold surface is in a non-contact state of about 1 inch, the lead components in the glass material will appear on the mold surface after heating. As a result, the surface of the mold is rapidly attacked and the surface precision of the mold is significantly reduced.

In order to solve these problems, Kibori et al. heated the molding die and the molding material in a separated state, and transferred the molding material to the mold during press molding. By doing so, it is possible to prevent erosion by the glass component of the mold, maintain the durability and surface precision of the mold, and create an optical element manufacturing waveform that allows high-precision optical elements to be manufactured continuously and before production. I have already proposed this.

The present invention relates to this manufacturing equipment δ. l: In the device described above, the mounting table on which the molding material and molding die are placed may vary in width due to thermal expansion during heating, and may not be transferred to the predetermined transfer position. . When such a situation occurs, the molding material is press-molded without being accurately transferred to the mold, resulting in the inconvenience that a highly accurate molded product cannot be obtained.

Book 9. The invention was developed in order to eliminate such inconveniences, and the purpose is to provide an optical element manufacturing apparatus that can accurately transfer the 4N mounting table to the transfer position of the molding material and perform press molding. shall be.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the optical element manufacturing apparatus of the present invention separates a material for molding an optical element from a mold for press-molding the material. An optical element manufacturing apparatus in which a plurality of mounting tables to be placed are transferred to a heating process, a pressing process, and a post-processing process, and when press-molding is performed in the pressing process, the material is transferred to the mold for press-molding, A first conveying means for sequentially extruding and conveying the alignment to the heating step and the pressing step, and a second conveying means for drawing out and conveying the optical element press-molded in the pressing step to the next step, The second conveying means moves the placing table in the opposite direction to the drawing direction of the stage when the first conveying means conveys the table and the table to the material transfer position. It is characterized in that positioning is performed by

(Function) In the optical element manufacturing apparatus of the present invention, the plurality of mounting tables on which the optical element molding materials and molding molds are placed are first passed through a heating process by the first conveying means.
Due to the tensioning of l11, the width of the i&mounting table varies, and the break is transferred to a state where the table is deviated from the predetermined transfer position. When a plurality of mounting tables are arranged, this variation in the width of each mounting table results in large fluctuations across the arrayed mounting tables, making it impossible to transfer the molding material accurately. Therefore, in the present invention, such a deviation of the mounting table from a predetermined position is corrected by moving the transporting means of tjS2 having a pull-out operation in a direction opposite to the pull-out direction to align it with the predetermined position.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of the p section of an embodiment of the present apparatus, showing a press molding process and a drawer cylinder which is a conveyance means to the next process in the entire optical element manufacturing apparatus shown in FIG. 4 below. FIG. 2 is a plan view showing the operating state of the drawer cylinder shown in FIG. 1, and FIG. 3 is a perspective view showing the configuration of the tip portion of the drawer cylinder.
FIG. 4 is a plan view of part a showing the entire apparatus of this embodiment.

First, the configuration of the apparatus of this embodiment will be explained based on these figures.

As shown in FIG. 1, the overall configuration of this device is as follows: a material intake chamber 1, a heating section 2, a material transfer section 3. It consists of a press section 5, an annealing section 6, and a molded product removal chamber 7. The material intake chamber 1, the heating section 2, the material transfer section 3, and the press section 5 are located in the same line (hereinafter, this line is referred to as the forming line 4).
, an annealing section 6 is arranged in parallel with the molding line.

A first transfer chamber 21 is constructed near the heating section 20, and an L material intake chamber 1 is provided in the first transfer chamber 21.

Further, a second transfer chamber 22 is configured near the outlet of the press 8B5, and a third transfer chamber 23 is configured at the entrance 11 of the slow cooling section 6, and these second and third transfer chambers are connected to the transfer path. They are connected by 25.

Further, a fourth transfer chamber 24 is constructed near the outlet of the slow cooling section 6, and this fourth transfer chamber 24 is provided with a moved molded product take-out chamber 7, and the transfer chamber 24 of :j54 and the above-mentioned It is connected to the first transfer chamber 21 through a feeding path 26 . With such a configuration, the present molding apparatus has a molding chamber 59 that forms a continuous circulation path.

Reference numeral 11 denotes a pallet to which the molding chamber 59 is transferred, and on the pallet 11, a material mounting table 12, an upper mold 13 and a lower mold 14 for press molding are arranged at a constant interval. There is. The press molding surfaces of the upper mold 13 and the upper mold 14 have mirror surfaces 13a for molding optical element functional surfaces, respectively.
14a is applied. As shown in FIG. 1, the valley 21 has a notch 30 on the side of the pallet that comes into contact with an adjacent pallet. When pallet 11 is heated, it transfers heat to adjacent pallets, but due to differences in contact conditions, each pallet experiences a partially uneven temperature rise. Each pallet may be non-uniform or have local variations. The cutout portion 30 is formed by reducing the contact area of the adjacent pallet (partial pallet) 1.
It acts to suppress the influence of temperature change in step 1.

The first transfer chamber 21 is provided with an extrusion cylinder 51 (A
I) is provided, and the pallet 11 is moved to the press section 5 by this extrusion cylinder. The second transfer chamber 22 is provided with a drawer cylinder 52 (referred to as B2) and an extrusion cylinder 53 (referred to as A2), and the pallet 11 moved to the press section 5 by the drawer cylinder 52 is transferred to the second transfer chamber. The pallet (11) pulled out into the second transfer chamber 22 and moved to the second transfer chamber by the extrusion cylinder 53 is pushed out to the third transfer chamber 23. The third transfer chamber 23 is provided with an extrusion cylinder/der 54 (referred to as A3), and the pallet (11) transferred to the transfer chamber 23 of the section 3 by this extrusion cylinder is delivered to just before the fourth transfer chamber 24. Being pushed. The fourth transfer chamber 24 includes a drawer cylinder 55 (referred to as B4) and a pusher cylinder 56.
(designated A4) is provided, and the valley tray 11 that has been moved to just before the fourth transfer chamber 24 by the drawer cylinder 55 is pulled out to the fourth transfer chamber 24, and the extrusion cylinder 56 The pallet 11 moved to the transfer chamber 24 of No. 4 is pushed out again to the first transfer chamber 21. In this way, the pallet 11 is transferred to each process by the extrusion or pull-out operation of these cylinders, and is transferred to the molding chamber 5 of this device.
Move within 9. The pallet 11 is placed on a rail (not shown) provided in the molding chamber 59, and is moved on the rail L by pushing out or pulling out each cylinder.

Next, the structure of the drawer cylinder 52 around the h3d material transfer section 3 and press section 5 will be explained with reference to FIG. 1.

Piston row and door 3 provided in the drawer cylinder 52
A hook piece 32 as shown in FIG. 3 is attached to the tip of 1. The piston rod 31 is the drawer cylinder 5
The rod is configured to reciprocate about 2 and rotate the rod. With this configuration, in order to pull out the pallet 11 after press forming by the drawer cylinder 52 into the transfer chamber 22, the piston rod 31 is rotated to the P position, the hook piece 32 is turned sideways, and the pallet 11 in the press section 5 is pulled out. The lower part is moved in the opposite direction to the drawing direction, and this movement is stopped when the hook piece 32 reaches the gap 30 between the pallet 11 in the press section 5 and the pallet 11 adjacent to the pallet 11. , then piston rod 3
1, the hook piece 32 is turned upside down, the hook piece hooks the side of the pallet 11, and the piston rod 31 is moved in the drawing direction.

The operation of aligning the repalette 11 with the drawer cylinder 52 operating in this manner will be described with reference to FIG. 2.

The A-A” line in Figure 2 is the transfer part 3 of pallet) 11.
Indicates the center of the transfer position in 1, for example, pallet 11.
This corresponds to the center position of the automatic hand when the automatic hand device is used to transfer the automatic hand. The line BB' is the center line of the pallet 11, and corresponds to a line connecting the centers of the material ti table 12 and the lower part 514 placed on the pallet.

In FIG. 2(a), the pallet in the press section 5 is Pl, the pallet in the transfer section 3 is P2, and the pallet following the transfer section is P3...Φ.

As shown in FIG. 2(a), after the press forming is completed, the hook piece 32 of the piston rod 31 is hooked on the notch 30 on the rear side of the Pi by the above-mentioned operation and pulled out in the drawing direction (second (b)), at this time, the transfer of the material 15 in the material transfer section 3 has been completed. When this pulled out pallet (PI) moves to the transfer chamber 22, the piston rod 36 of the extrusion cylinder 51
is pressed against the side of pallet (11) at the rearmost end of the molding line 4 and extruded. As a result, a plurality of The pallets are pushed out in a concentric manner, and the first pallet P2 (the material transfer has already been completed as described in h) moves to the press section, and the pallet P3 following this pallet P2 moves to the material transfer section 3. At this time, Figure 2 (c
), the pallet 11 at the rearmost end of the molding line 4
The center position IB-B' of the valley 2 pallet P3 which has been moved to the material transfer section 3 due to thermal expansion generated in each pallet from P3 to the pallet P3 of the material transfer section 3) and the center of the material transfer section 3 An error occurs in the position fiA-A'. Therefore, the hook piece 32 at the tip of the piston rod 31 of the drawer cylinder 52
When the rod 31 is rotated to an inverted state, the rod 31 is moved in the opposite direction to the drawing direction and applied to the front side of the pallet P2, and the drawer cylinder 52 is operated with a constant stroke in the direction opposite to the drawing direction. Pallet P3 is aligned at a predetermined transfer position. In order to perform such alignment, the stroke in the opposite direction to the drawing direction of the cylinder 52 is made so that the center position 2tB-B' of the pallet at the transfer position is the center position A of the auto hand.
- Set 5 to match A'.

In the above-mentioned positioning operation, when aligning with the drawer cylinder 52, there is only one pallet P2 between the pallet 11 in the transfer section 3 and the piston rod 31 of the drawer cylinder 52. ) It is possible to accurately align the valley two points P3 without being significantly affected by the thermal expansion of P2.

Here, the operation timing of each extrusion cylinder and drawer cylinder will be explained in detail with reference to Fig. 1θ and Fig. 11.

Fig. 1θ is a schematic diagram of Fig. 4 and shows the operation control means for the pushing and drawing means in the present device, and Fig. 11 is a diagram showing a timing chart of the pushing and drawing means shown in Fig. 1O. be.

In the schematic diagram of the wooden δ shown in FIG. 1θ, the symbols Al-A4 and Bl-B4 are given to each of the extrusion cylinders and drawer cylinders. In addition, V1 to V4 in the figure are pressure regulating valves that are connected to the above-mentioned extrusion cylinders and drawer cylinders to control the pressure in these cylinders, and these valves are connected to the controller 〇. ~C4 indicates a control signal sent to each valve. Also, in the timing chart shown in FIG. The timing of operation is indicated. A required number of barrels 11 are arranged in advance in the molding line 4 and slow cooling section 6 in the molding chamber 59. For convenience of explanation, it is assumed that the molding material 15 has already been supplied to each of these pallets, and in the following explanation IJJ, molding operations such as transferring the molding material and press forming are omitted.

First, the drawer cylinder 52 (B2) is operated to move the pallet 11, which has been press-formed in the press section 5, to the second transfer chamber 22 (To~T1)0.Then, the extrusion cylinder 51 (AI) is operated. At the same time, the pallet 11 at the head of the molding line 4 is moved to the press section 5, and at the same time, the extrusion cylinder 53 (A2) is activated to
The pallet 1 that has been moved to the third transfer chamber 22 is pushed out to the third transfer chamber 23 (TI-72), in this way,
By operating the extrusion cylinders 51 and 53 (AI, A2) at the same time, the molded product 18 that has been press-molded can be quickly transferred to the annealing section 6, thereby shortening the entire manufacturing time. Also, at this time, the second transfer chamber 22 becomes empty and can be prepared for the next step of drawing out the drawing cylinder 52 (B2). After moving the pallet 11 at the head of the forming line 4 to the press section 5, as described above, the pallet 11 moved to the material transfer section 3 is moved to the L
The pallet 11 in the material transfer section 3 is moved by moving the drawer cylinder 52 (B2) in the opposite direction to the drawer direction.
At the same time, the pallet 1 that has been moved to the third transfer chamber 23 is pushed out and transferred to the fourth transfer chamber 24 by the extrusion cylinder 54 (A3).
The pallets extruded in the direction of and already arranged in the slow cooling section 6)1
1 to just in front of the fourth transfer chamber 24 (
T2 to T3), furthermore, this extrusion cylinder 54 (A
3) At the same time as the extrusion operation, the extrusion cylinder 56 (A4
) to push out the pallet 11, which has already been moved to the fourth transfer chamber 24, to the first transfer chamber 21 (T2~
T3)0 Next, the drawer cylinder 55 (B4) is operated to pull out the first pallet (11) that has moved to just before the fourth transfer chamber 24 to this fourth transfer chamber (T3-T
4), as mentioned above, the extrusion cylinder 54.55 (
By operating A3 and A4) at the same time, the fourth transfer chamber becomes empty and the drawer cylinder 55 is quickly operated, shortening the residence time of the molded product in the annealing section 6 and shortening the entire manufacturing time.

Thus, the pallet 11 is moved into the molding chamber 59 by the above-described operation.
can move within.

In addition, the taking in of the molding material 15 and the taking out of the molded product 18 are carried out after the leading pallet 1 of the slow cooling section 6 is pulled out to the fourth transfer chamber 24 by the drawer cylinder 55 (B4) and then transferred to the extruder cylinder 56 (A4). The molded product 18 is taken out before the extrusion operation (T4-T2), and then the pallet is extruded into the first transfer chamber 21 by the extrusion cylinder 56 (A4).
The raw material 15 is taken in until the extrusion operation in I) (T3 to TI).

Next, each part of the molding chamber 59 will be explained.

Heating section 2, material transfer F! A heater 57 is provided in the furnace body corresponding to &3 and the press section 5, and a heater 58 is provided in the furnace body corresponding to the slow cooling section 6. Each of these heaters is used for heating the material 15 and slowly cooling the molded product 18 after pressing.

The upper mold 13 and the lower mold 1 are placed in the material transfer section 2 and the molded product removal chamber 7.
Lifting hand 16 for lifting 4 at required intervals
．． 20 (FIGS. 7 and 9), this lifting hand is moved up and down by a lifting means (not shown). Furthermore, the material transfer section 3 is provided with a suction finger 19a (a seventh After the upper mold 13 is once lifted by the operation of the lifting hand 16, the suction hand is activated and the material 15 is transferred to a predetermined position on the lower mold 14. This suction finger 19a is designed to ensure that the material 15 is accurately placed at a predetermined position on the lower die l4 when transferring the material 15 as described above.
It is configured to operate with a constant stroke in which the workpiece 'a mounting table 2 on the pallet 11 and the lower die 14 are accurately translated in parallel by a length of a predetermined interval.

In addition, suction fingers 19b for placing the material 15 on the mounting table 12 and taking out the molded product 18 from the upper mold 14 are provided in the material intake chamber l and the molded product removal chamber 7 (
Figure 9).

The press section 5 is provided with a press rod 17 for pressing the upper mold 13 during press molding (Fig. 8).
.

In this mold δ, the inside of the molding chamber 59 is evacuated and then filled with non-oxidizing gas such as N2 gas to prevent the mold material forming the upper mold 13 and 'jfi 14 from being oxidized at high temperatures. Because it needs to be filled, use the lifting hand 1 above.
6. Suction fingers 19a, 19b and press rod 1
It is necessary to provide sufficient shielding to the sliding portion between the molding chamber 59 and the outer wall of the molding chamber 59.

In addition, in this device, although not shown, the material 1
5 into the material intake chamber 1, it is necessary to provide an atmosphere exchange chamber to prevent outside air from entering the molding chamber 59.

Next, we will discuss the operation of the device configured as described above in the fifth section.
The description will be made according to the order of the press molding steps shown in FIGS.

Figure 5 shows the baren in a state where the material 15 is not placed) 1
1 is shown.

First, as described above, in order to prevent the mold materials of the upper and lower molds 13 and 14 from oxidizing, the inside of the molding chamber 59 is evacuated to I x 10-2 Torr using a vacuum pump (not shown), and then
After filling with N2 gas or other non-oxidizing gas, the heaters 57 and 58 are energized to raise the temperature inside the furnace to a predetermined value. After the temperature has been raised, the material 15 is passed through the atmosphere replacement chamber in the material intake chamber 1, and is placed on the mounting table 12 of the baren 11 in the material intake chamber 1 by the suction fingers 19b, as shown in FIG.

Next, according to the above-mentioned operation timing, the push cylinders 51.53, 54.55 and the draw cylinder 52.
58 is operated to sequentially transport the material 15 from the molded product take-out chamber 7 to the material intake chamber 1, the material 15 is placed on each mounting table 12 in the above-described manner.

While performing such operations, the material 15 supplied to the first pallet 11 and the upper y! When the material 13 and the lower mold 14 are heated to the temperature required for press molding near the material transfer section 3, the material 15 is transferred to the lower mold 14.
At this time, it is desirable that the material 15 and the upper mold 13 and the lower mold 14 be heated to approximately the same temperature. Press molding can be performed under optimal press temperature conditions without changing the temperature of 14. Then, in the material transfer section 3, as shown in FIG. 7, the upper mold 13 is lifted by the lifting hand 16, and then the material 15 is sucked by the suction fingers 19a and transferred onto the lower mold 14. After this, the extrusion cylinder 51 is extruded and the material 1 is
5) is moved to the position of the press section 5. Then, by the above-described operation, the positioning of the barens 11 in the material transfer section 3 is performed.
Next, the lifting hand 16 is removed and the press rod 17 is activated to apply a predetermined press pressure to the upper 5!1
3 to perform press forming on the material 15. Next, the pressing of the press rod 17 is released, and the pallet 11 is pressed while the upper die 13 maintains its state at the time of pressing.
is moved from the press section 5 to the second transfer chamber 22. Furthermore, this pallet 11 is transferred to the third transfer chamber 2 via the transfer path 25.
3) Next, the pallet 1 is moved in the direction of the slow cooling section, but in front of this direction of movement is another pallet 1)
1 are arranged, and as the above-mentioned operation continues, the molded product held in the upper mold 13 and lower fi 14 where the barrels 11 reach the vicinity of the outlet of the slow cooling section 6. 18
passes through an annealing section 6, where it is gradually cooled.

In this way, the pallet 1 has moved to the top position of the slow cooling section 6.
1 is moved to the molded product removal chamber 7.

Next, the lifting hand 20 is operated to remove the upper mold 13, and then the molded product 18 is removed by the suction finger 19b.
Ill be ill. Then, the pallet (11) from which the molded product has been removed is transferred to the lumber intake chamber l via the feeding path 26.
Continuous molded product 1 is made by repeating the two series of operations again.
8 is manufactured.

Theory 1! According to the apparatus according to the embodiment, press molding can be performed by accurately aligning the positional deviation of the pallet 11 caused by thermal expansion before press molding.

Also, the material 15 is placed on the material mounting table 12 until just before press forming]
- and is separated from the upper mold 13 and lower mold 14, so that reaction between the material 15 and the molds 13 and 14 is prevented. Of course, this does not prevent reactions between the material 15 and the molds 13 and 14 from occurring during press molding and subsequent slow cooling, but when the temperature decreases after press molding, no reaction occurs during press molding. First, in combination with the effect of shortening the reaction time mentioned above, this is beneficial for improving the durability of the mold.

Furthermore, since the apparatus of this embodiment is configured to transfer materials on the same pallet, there is no relative change in the positions of the material a, the mounting table 2, and the mold, and the handling of the suction fingers 19 is simplified. Positioning accuracy is easily achieved, and since the suction fingers 19 are heated at the same time as the pallet 11 inside the molding chamber 59, errors in handling positioning accuracy due to 8 expansions are less likely to occur.

Furthermore, according to the apparatus of this embodiment, the durability of the mold is guaranteed as described above, erosion of the molding surface is prevented, and the specularity of the molding surface is maintained for a relatively long period of time. Suitable for continuous production of precision optical elements.

(Effects of Development II) As explained above, according to the present invention, it is possible to accurately align the positional deviation of the AT stand caused by thermal expansion before press forming, and thus press forming can be performed with high precision. Suitable for continuous molding equipment for precision optical elements.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts related to an embodiment of the apparatus of the present invention, showing a press molding process and a drawer cylinder which is a conveyance means to the next process in the entire optical element manufacturing apparatus shown in FIG. 4 below. It is. FIG. 2 is a plan view showing the operating state of the drawer cylinder shown in FIG. 1. FIG. 3 is a perspective view showing the structure of the distal end portion of the drawer cylinder. FIG. 4 is a schematic plan view showing the entire apparatus of this embodiment. 5 to 9 are schematic sectional views of the mounting table in each step of the apparatus shown in FIG. 4. FIG. 10 is a schematic diagram of FIG. 4, showing the operation control means for the pushing and drawing means in the wooden δ. FIG. 11 is a timing chart of the pushing and pulling +41L means shown in FIG. 10. l...Material intake chamber 2...Heating section 3...Material transfer section 4...Molding line 5...Press section 6...Annealing section 11...Pallet 12...Material a1 unit 13...Lη! 14... Lower mold 30... Notch portion 31... Piston rod 32... Hook piece 51.52.54.56... Extrusion cylinder 52.
55... Drawer cylinder 59... Molding chamber

Claims (1)

[Claims] A heating process is performed on a plurality of mounting tables on which a material for molding an optical element and a molding die for press-molding the material are placed in a separated state.
In an optical element manufacturing apparatus, the material is transferred to a press step and a post-processing step, and when press-molded in the press step, the material is transferred to the mold for press molding. a first conveying means for sequentially extruding and conveying the optical element, and a second conveying means for drawing out and conveying the optical element press-molded in the press step to the next step, and the second conveying means When the placing table is transported by the means to the material transfer position, the placing table is moved in a direction opposite to the pull-out direction of the second conveying means to perform positioning. Optical element manufacturing equipment.