JP3454530B2 - Glass optical element molding apparatus and molding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element molding apparatus and a molding method for press-molding a glass material softened by heating.

[0002]

2. Description of the Related Art Conventionally, as a molding apparatus for press-molding a glass material which has been softened by heating, for example, JP-A-64-5633 is used.
There is an invention described in Japanese Patent No. 2 publication. The above-mentioned invention is configured such that a glass material is filled in a mold and a body mold to be integrated into a mold block, and a weight is arranged on the mold of the mold block so that force is applied in the molding direction. ing.

Another molding apparatus is, for example, the invention described in Japanese Patent Laid-Open No. 2-225325. In the above invention, the press shaft to which the mold is fixed is held in the housing so as to be slidable in the axial direction via a bearing, and can be lifted and lowered via a drive air cylinder. The glass material is configured so that a force is applied in the molding direction.

[0004]

However, the above-mentioned respective prior arts have the following problems. That is, JP-A-64
In the invention described in Japanese Laid-Open Patent Publication No. 56332, a molding block is formed by filling glass into a molding die and a body die, and by placing a weight on the molding die, the molding block is pressed in the molding direction. is there. Therefore, the force applied in the molding direction can be changed by changing the weight.

However, in order to change the force applied in the molding direction, a weight corresponding to the set weight must be prepared for each molding block. Therefore, although there is no problem when mass-producing a small number of types of lenses, when molding a large number of types of lenses, the types and amounts of weights to be prepared increase, and the workability is significantly deteriorated due to the preparation for molding. .

Further, when molding a small-diameter lens, it must be molded with a minute pressing force. However,
In the invention described in JP-A-64-56332,
It is difficult to realize a minute pressing force due to the weight of the mold itself.

In the invention described in Japanese Patent Application Laid-Open No. 2-225325, which is an apparatus capable of molding various kinds of lenses with good workability, it is difficult to apply a minute force in the molding direction. Further, as shown in the embodiment, the bearing supporting the press shaft for applying a force in the molding direction is separated from the heat source so as to ensure the sliding accuracy in the axial direction. Therefore, the press shaft becomes long and the weight of the press shaft itself increases. Therefore, the press shaft raised by the driving air cylinder is
An inertial force is generated due to the increased weight, and the impact force at the moment when the mold comes into contact with the glass material is large. For the above reasons, it is difficult to apply a minute force in the molding direction with the device configuration disclosed in the invention described in JP-A-2-225325.

Therefore, the present invention has been developed in view of the problems in the above-mentioned respective prior arts, and can deal with various kinds of optical element moldings and can provide a small load necessary for obtaining a precise transfer with a small diameter lens. It is an object of the present invention to provide a glass optical element molding apparatus and a molding method capable of adding a glass.

[0009]

The present invention provides a glass optical element molding apparatus for molding a desired optical element by pressing an optical material that has been heated and softened by a pair of molding dies opposed to each other. A main shaft portion that supports one of the pair of molding dies and is movable back and forth in the axial direction, and a weight balancer that is provided on the main shaft portion and that adds a molding load to the weight that cancels the weight of the main shaft portion, And a speed controller for controlling the speed of the main shaft portion that slides by the weight balancer.

Further, in a glass optical element molding method for pressing a heat-softened optical material by a pair of molding dies opposed to each other to mold a desired optical element, one of the pair of molding dies is used. It has a weight balancer that supports the shaft and is movable back and forth in the axial direction, and adds a molding load to the weight that cancels the weight of the main shaft.While controlling the speed, the main shaft slides to contact the optical material. After that, the optical material is pressed by the weight balancer.

Further, in a glass optical element molding apparatus for pressing a heat-softened optical material by a pair of molding dies opposed to each other to mold a desired optical element, one of the pair of molding dies is used. A main shaft part that supports the main shaft part and is movable back and forth in the axial direction; a pneumatic cylinder that is fixed to the molding apparatus main body and is connected to the main shaft part through a wire; and the main shaft part that slides by the pneumatic cylinder. And a speed controller for controlling the speed of the.

In the glass optical element molding method of pressing a heat-softened optical material by a pair of molding dies opposed to each other to mold a desired optical element, one of the pair of molding dies is used. It is equipped with a pneumatic cylinder that applies a tensile load equivalent to the weight of the main shaft and the forming load to the main shaft that supports the optical axis and is capable of moving back and forth in the axial direction. And the optical material is pressed by the pneumatic cylinder.

FIG. 1 is a conceptual diagram showing the present invention. The upper mold 7 and the lower mold 3 for molding the optical material 1 are arranged to face each other. The lower die 3 is mounted on the upper end of a vertically movable main spindle 11, and at the lower part of the main spindle 11, a speed controller 17 that suppresses acceleration (inertial force) when the main spindle 11 rises and a balancer 13 that determines the pressure. Is provided.

In the molding method using the apparatus having the above structure, first, the optical material 1 heated to a predetermined temperature is conveyed between the upper mold 7 and the lower mold 3. Next, the lower mold 3 is raised while being controlled by the speed controller 17, and the optical material 1 is molded. At that time, the lower mold 3 placed on the main shaft 11 which is raised at a constant speed by the speed controller 17 comes into contact with the optical material 1 with a low impact, and then the weight is set by the balancer 13 so that a minute molding pressure is applied. A minute molding pressure is applied.

[0015]

[Embodiment 1] FIG. 2 is a partial sectional side view showing an apparatus used in this embodiment. In this embodiment, a weight is used as the weight balancer. The molding chamber 18 includes an upper base 10, a lower base 6, and a cover 15. The plate-shaped upper base 10 has a hole in the center thereof, and the upper die support 9 is fitted and fixed in the hole.

The columnar upper die support 9 has a screw at its end, and fixes the upper die 7 via an upper die retainer 8. Lower mold 3
Like the upper die 7, is fixed to the lower die support 5 via the lower die presser 4. The lower die support 5 is fitted and fixed to the main shaft 11. The lower base 6 has a hole in the center thereof so that the main shaft 11 can be loosely fitted thereto, and is installed on the mount 20. A main bearing 16 is fixed to a lower end surface portion of the main shaft 11, an arm 21 is fixed to the main bearing 16 by passing a pin 24 through the central portion and the main bearing 16, and the arm 21 is fixed around the pin 24. It is configured to

A support board 23 is fixed on a speed controller 17 (for example, a pneumatic cylinder), and an L-shaped angle 12 is erected on the side surface of the support board 23.
The step portion 16a of the main bearing 16 and the protruding portion of the angle 12 are in a position where they can come into contact with each other. The main shaft 11 is guided by a bearing 14 and is configured to be capable of moving in the up and down directions in conjunction with the speed controller 17.

The balancer 13 includes a weight 13a and a wire 1
3b and a pulley 13c, each of which is symmetrically suspended around the main shaft 11. Wire 1
3b has screw parts (not shown) at both ends, one end is fixed to the arm 21, and the other end is fixed to the weight 13a.
It is suspended via a pulley 13c. In addition, pulley 13c
Is fixed to the frame 20 of the molding machine body. Hereinafter, the main shaft 11, the lower die 3, the lower die presser 4, the lower die support 5, the main bearing 1
6, the arm 21 and the pin 24 are collectively referred to as a main shaft portion. Here, the weight of the weight 13a has a relationship of the weight of the main shaft portion + the molding pressure weight.

In the molding method using the apparatus having the above-mentioned structure, first, the optical material 1 placed on the barrel mold 2 is heated to the softening point or above in a heating furnace (not shown) provided in the vicinity of the molding chamber 18. Heat to. Next, the optical material 1 and the barrel die 2 are conveyed by a conveying member (not shown) between the upper die 7 and the lower die 3 heated near the transition point of the optical material 1.

After that, although the main shaft portion is raised by the driving of the speed controller 17, the weight of the weight 13a is set to be heavier than the weight of the main shaft portion by the molding pressure, and the angle 12 and the step portion 16a of the main bearing 16 are set. Are in contact with each other, and the ascending speed of the speed controller 17 is set to be slower than the ascending speed of the spindle part by the weight 13a, so that the ascending speed of the spindle part 11 becomes the same as the ascending speed of the speed controller 17. Become.

Next, the main shaft portion stops when it rises to a position where the optical material 1 is press-molded. At this time, the rise of the speed controller 17 is stopped at a position where the angle 12 and the step portion 16a of the main bearing 16 are separated from each other and the main bearing 16 and the support board 23 are not in contact with each other as shown in FIG. It is set by a sensor (not shown).

When the lower die 3 and the optical material 1 are brought into contact with each other, a large weight of the main shaft portion is canceled by the weight 13a and only the pressurizing weight is added, and the inertia force is small and the contact is made with a low impact. . Then, the molding pressure added to the weight 13a is applied to the lower mold 3, and the optically functional surface is precisely transferred to the heated and softened optical material 1.

According to the present embodiment, since the weight of the weight 13a is set to the weight of the main shaft portion + the molding pressure weight, the speed controller 17 is driven to raise the main shaft portion at a constant speed, and the optical material 1 When it comes into contact with, the inertia force of only the molding pressure weight is applied, and the lower mold 3 has a low impact and the lower mold 3 is made of the optical material 1.
To contact. After that, since the set molding pressure is applied to the lower mold 3, even a lens with a small diameter or thin wall that may be cracked by excessive pressure can be pressed with low impact and low pressure without breaking, and the optical function of the lower mold 3 The surface is precisely transferred to the optical material 1. Further, by changing only the weight of the weight 13a, various molding pressures can be set, and it is possible to cope with various optical element moldings with extremely high workability.

Although the weight of the weight 13a is set to the weight of the main shaft portion + the molding pressure weight, the weights of the optical material 1 and the barrel die 2 are actually added at the time of molding. By taking the weight of 2 into consideration and setting the weight of the weight 13a to the weight of the main shaft portion, the optical material 1 and the body mold 2 plus the molding pressure weight, a more precise molding pressure can be set.

[0025]

[Embodiment 2] FIG. 3 is a partial sectional side view showing an apparatus used in this embodiment. In the present embodiment, the same components as those in the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted. Only different portions will be described.

The basic structure is the same as that of the first embodiment,
A sensor 25 is installed at the lower end of the main shaft 11.
Further, the main bearing 16 fixed to the lower end surface of the main shaft 11 has an arm 21 fixed around a pin 24. The arm 21 is suspended by a pulley 13c fixed to the frame 20. A load cell 27 is fixed to the lower side of the main bearing 16, and a main shaft actuating member 26 having a step is fixed to the lower end surface of the load cell 27.

An L-shaped angle 12 is erected on the side surface of a support board 23 supported by the speed controller 17,
The protruding portion of the angle 12 has a form capable of contacting the stepped portion of the main shaft operating member 26, and the main shaft 11 is supported by the speed controller 17 in this state. Further, a roller 35 is installed on the arm 21 and a stopper 28 is installed at a symmetrical position of the roller 35.

The upper end of the housing 19 which guides the vertical movement of the main shaft 11 by the bearing 14 is fixed to the lower base 6, and the lower end is fixed to the stationary platen 33. A through hole for the main shaft 11 is opened in the center of the fixed plate 33. A guide 36 is provided on the lower surface of the fixed plate 33, and the guide 36
A stopper 29 is engaged with this so as to be slidable in the horizontal direction. The stopper 29 is formed with a tapered surface 29 a that comes into contact with the roller 35 of the arm 21. Further, a driving device 30 such as a pneumatic cylinder is fixedly installed on the lower surface of the stationary platen 33, and the support shaft of the driving device 30 is a stopper 29.
And is configured to be able to move the stopper 29. Further, a stopper 29 is provided on the lower surface of the fixed plate 33.
A stopper adjusting table 31 for controlling the position of is installed.

At the symmetrical position of the stopper 29 on the lower surface of the fixed plate 33, a hard material (for example, a super hard material) which is not deformed even when the stopper 28 provided on the arm 21 receives an impact.
The stopper receiver 32 is installed. Further, a controller 34 for controlling the timing of driving the driving device 30 by receiving a signal from the sensor 25 installed on the side surface of the main bearing 16 is provided. Hereinafter, the main shaft 11, the lower mold 3, the lower mold retainer 4, the lower mold support 5, the main bearing 16, the arm 21, the pin 24, the roller 35 and the stopper 28 are collectively referred to as a main shaft portion. Where the weight 13a
Is related to the weight of the main shaft portion + the weight of the molding pressure.

In the molding method using the apparatus having the above construction, first, the optical material 1 placed on the barrel mold 2 is heated to a softening point or higher in a heating furnace (not shown) provided in the vicinity of the molding chamber 18. Heat to. Next, the optical material 1 and the barrel die 2 are conveyed by a conveying member (not shown) between the upper die 7 and the lower die 3 heated near the transition point of the optical material 1.

Thereafter, the main shaft portion is raised by driving the speed controller 17, and the optical material 1 is press-molded by the molding surfaces of the upper mold 7 and the lower mold 3. At that time, the weight 13a
Is set to be heavier by the molding pressure than the total weight of the main shaft portion. Therefore, the angle 12 and the step portion 16a of the main bearing 16 are set.
Are in contact with each other, and the ascending speed of the speed controller 17 is set to be slower than the ascending speed of the weight 13a.
It rises at the same speed as 7. At this time, the pressing pressure is monitored by the load cell 27.

Therefore, the distance between the upper mold 7 and the lower mold 3 is set so that the inner wall of the optical material 1 is desired in advance by the roller 35.
And the stopper 28 so that when the lower die 3 and the main shaft portion are lifted, the roller 35 causes the stopper 2 to move.
9, the stopper 28 comes into contact with the stopper receiver 32, so that the lifting of the main shaft portion is stopped. Further, since the arm 21 can rotate around the pin 24,
The force generated when stopping the rise of the main shaft is the roller 35
And the stopper 28 are generated at the same time, and are installed symmetrically with respect to the center of the main shaft 11, so that no moment is generated on the main shaft 11.

Further, the sensor 25 senses the moment when the raising of the main shaft portion is stopped by the roller 35 and the stopper 28, and the controller 34 receives the signal and operates the drive device 30 at a predetermined timing. The sensor 25
For example, an approach switch is used, the roller 35 is the stopper 29, and the stopper 28 is the stopper receiver 32.
The position of the sensor 25 such as the height is adjusted so that the signal from the sensor 25 is output at the position where the sensor 25 comes into contact with.

Since the stopper 29 and the roller 35 are supported by a ball bearing or the like, the stopper 29 can be moved in the horizontal direction with a comparatively small force even if the stopper 29 and the roller 35 receive a force generated at the time of stopping due to the rising of the main shaft portion. There is. Therefore, the stopper 29 can easily move in the horizontal direction in synchronization with the movement of the driving device 30 without any time delay. Then, in the process in which the pressed optical material 1 is cooled and solidified and contracts, the drive device controlled by the controller 34 so that the stopper 29 can be removed not too early or too late from the time when the sensor 25 detects it. The stopper 29 is horizontally moved by 30 and is removed. As a result, the optical material 1 is pressed, and pressure is applied during contraction.

According to this embodiment, the space between the upper die 7 and the lower die 3 is adjusted so that the inner wall of the optical material 1 has a desired thickness, and the main shaft portion having a small inertial force In the process of the optical material 1 pressed by a low impact cooling and solidifying as well as shrinking, the sensor 25 detects the moment when the rising of the main shaft part stops, so that the stopper 29 can be removed at neither too fast nor too late timing. By providing the controller 34 and the drive device 30 in the above, the molded optical element can secure the accuracy of the inside thickness and prevent the sink of the surface. In particular, in the case where the optical material 1 is a material having a flat surface or a spherical surface, it is possible to perform molding with extremely good medium precision and transferability in molding with a large glass deformation amount for obtaining a desired lens shape.

[0036]

[Embodiment 3] FIG. 4 is a partial sectional side view showing an apparatus used in this embodiment. The present embodiment is different in that the weight 13a and the pulley 13c are eliminated as the weight balancer in the first embodiment, and a pneumatic cylinder is used instead, and the other configuration is made up of the same component parts. The same numbers are given to the parts and the description thereof is omitted.

In this embodiment, one end of the wire 13b is fixed to the arm 21 installed on the main shaft 11, and the other end is fixed to the pneumatic cylinder 13d. The pneumatic cylinder 13d is fixed symmetrically around the main shaft 11 to a member (not shown) such as a reinforcing plate that is coupled and held to the gantry 20. Hereinafter, the main shaft 11, the lower die 3, the lower die presser 4, the lower die support 5, the main bearing 1
6, the arm 21 and the pin 24 are collectively referred to as a main shaft portion.

In the molding method using the apparatus having the above-described structure, the pneumatic pressure of the pneumatic cylinder 13d can cancel the weight of the main shaft portion and apply the tensile load to which the molding load is added to the main shaft. Perform with air pressure set. Hereinafter, the operation is similar to that of the first embodiment, and the description of the operation is omitted.

When the weight 13a is used as in each of the above-mentioned embodiments, there is a risk that when the spindle 11 is raised at a high speed and brought into contact with it, a bouncing occurs and the spindle 11 is momentarily pressurized by its weight. is there. According to this embodiment, the pneumatic cylinder 1
By using 3d, the impact and the bounce phenomenon can be prevented, the spindle 11 can be raised with high accuracy, and the contact between the lower die 3 and the optical material 1 and the pressure processing can be performed smoothly even when the molding pressure is low. You can do it. Furthermore, pneumatic cylinder 13d
By using, the weight can be easily set and the workability is significantly improved.

In this embodiment, the speed of the main spindle is controlled by the speed controller as in each of the above embodiments. However, the speed of the main spindle is controlled by controlling the air pressure of the pneumatic cylinder used in this embodiment. It is also possible to control

[0041]

As described above, according to the molding apparatus and the molding method for a glass optical element of the present invention, the weight of the main shaft portion is canceled and only the molding load is applied to the main shaft portion to control the main shaft. By sliding while sliding, the inertial force when the spindle is raised can be made extremely small, and the impact force at the moment when the lower die comes into contact with the heat-softened optical material and presses it can be made extremely small. Therefore,
In molding a lens having a small diameter and a thin wall, cracking or breakage does not occur, and molding with good transferability can be performed. Further, it is extremely easy to set the molding pressure corresponding to the lens shape, and it is possible to extremely efficiently perform the production of various products.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing the present invention.

FIG. 2 is a partial cross-sectional side view showing the first embodiment.

FIG. 3 is a partial cross-sectional side view showing a second embodiment.

FIG. 4 is a partial cross-sectional side view showing a third embodiment.

[Explanation of symbols]

1 Optical material 3 Lower mold 7 Upper mold 11 spindle 13 Balancer 17 Speed controller

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C03B 11/00-11/16

Claims (4)

(57) [Claims] 1. A glass optical element molding apparatus for pressing a heat-softened optical material by a pair of molding dies opposed to each other to mold a desired optical element, wherein one of the pair of molding dies is used. A main shaft part that supports the main shaft part and is movable back and forth in the axial direction; a weight balancer that is provided on the main shaft part and adds a molding load to the weight that cancels the weight of the main shaft part; and the main shaft part that slides by the weight balancer. And a speed controller that controls the speed of the glass optical element. 2. A glass optical element molding method for molding a desired optical element by pressing an optical material that has been heated and softened by a pair of molding dies arranged opposite to each other, wherein one of the pair of molding dies is used. It has a weight balancer that supports the shaft and is movable back and forth in the axial direction, and adds a molding load to the weight that cancels the weight of the main shaft.While controlling the speed, the main shaft slides to contact the optical material. After that, the optical material is pressed by the weight balancer, and a glass optical element molding method. 3. A glass optical element molding apparatus for pressing a heat-softened optical material by a pair of molding dies opposed to each other to mold a desired optical element, wherein one of the pair of molding dies is used. A main shaft part that supports the main shaft part and is movable back and forth in the axial direction; a pneumatic cylinder that is fixed to the molding apparatus main body and is connected to the main shaft part through a wire; and the main shaft part that slides by the pneumatic cylinder. And a speed controller that controls the speed of the glass optical element. 4. A glass optical element molding method for molding a desired optical element by pressing a heat-softened optical material by a pair of molding dies opposed to each other, wherein one of the pair of molding dies is used. It is equipped with a pneumatic cylinder that applies a tensile load equivalent to the weight of the main shaft and the forming load to the main shaft that supports the optical axis and is capable of moving back and forth in the axial direction. A method for molding a glass optical element, which comprises press-molding an optical material with the pneumatic cylinder after bringing the optical material into contact with the glass material.