JP3157594B2 - Optical element molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for producing an optical element having high precision by press molding.

[0002]

2. Description of the Related Art Conventionally, there is an invention described in Japanese Patent Application Laid-Open No. 2-133328, for example, with respect to a mold release after pressing.
In the above invention, a cooling gas discharge pipe is provided in a molding chamber, and a cooling gas is blown to a glass material or a carrier during press molding to improve the releasability of the glass material and a molding die.

[0003]

However, a cooling mechanism using a cooling gas of a glass material or a carrier for reducing the molding force between the temperature of the mold and the temperature of the glass material to cause a large fluctuation or to reduce the releasing force. If the failure does not occur, the optical contact phenomenon between the surface of the molding die and the optical element causes a release force several times larger than usual between the molding die and the optical element. This more than usual release force has an adverse effect such as causing a positional shift in the support state between the molding die and the holding shaft.

[0004] Accordingly, the release force is one important parameter for judging the quality of the molded state. However, in the above-mentioned prior art apparatus, at present, a mechanism for detecting the release force and a mechanism for determining whether the release force is good or not are not provided. For this reason, there was a problem that much manpower was required for management of a molding state.

Accordingly, the present invention has been developed in view of such a problem, and a detection mechanism for detecting a release force is provided on a holding shaft supporting a movable mold, and the release force is detected. An object of the present invention is to provide an optical element molding apparatus capable of automatically monitoring and managing the state of a molding process by installing a judgment apparatus for judging pass / fail.

[0006]

SUMMARY OF THE INVENTION The present invention provides an optical element having a mold for pressing a heat-softened glass material, a holding shaft for supporting the mold, and driving means for moving the holding shaft forward and backward. In the molding apparatus, a detecting means for detecting a releasing force after the pressing step is interposed between the holding shaft and the driving means, and a separating means for judging whether the releasing force detected by the detecting means is good or not. This is configured by providing a mold force determining means.

[0007]

According to the present invention, the release force generated by the optical contact between the molding die and the optical element is detected by a detection mechanism provided on the holding shaft, and the release force generated by the judgment device is determined to be a normal value or an abnormal value. By determining whether the value is a value for each molding, the state of the molding quality is monitored and managed.

[0008]

[Embodiment 1] FIG. 1 is a schematic sectional view showing a part of this embodiment. A sliding hole 2 penetrates into the upper portion of the base 1,
The holding shaft 5 holding the movable mold 4 at the upper end is slidably moved up and down via the ball retainer 3. A guide shaft support 6 is fixed to the center of the base 1, and a nut 9 is movably held on the support 6 via two guide shafts 7 and a ball bush 8. The nut 9 is rotated by a pulse motor 11 installed on the upper part of the support base 6, and is driven up and down by a ball screw 12.

A cylinder 14 is connected to a lower portion of the nut 9 via a cut flange 13, and the cylinder 14 is connected by a connecting member 15 to a distal end of a connecting member 16 fixedly projecting from the lower end of the holding shaft 5. A strain gauge type load cell 23 is provided between the holding shaft 5 holding the movable mold 22 and the connecting member 16 connecting the driving unit.

An analog signal from the load cell 23 is digitized by an analog / digital converter 24 installed outside the molding machine, and is input to a computer 26 via an interface board 25. Computer 2
Signal lines are connected from 6 to the CPU 27 of the control unit of the molding machine via the interface board 25.

In the molding apparatus having the above structure, the carrier 18 on which the glass material 17 is placed is carried into the molding chamber 20 by the transfer arm 19 and positioned between the upper and lower molding dies 21 and 22. When the loading of the glass material 17 is completed, the ball screw 12 is rotated by the pulse motor 11, and the nut 9 and the cylinder 14 connected to the nut 9 are raised along the guide shaft 7. Accordingly, the holding shaft 5 connected by the connecting member 16 is also pulled up, and the glass material 17 is pressed.

After the glass material 17 or the carrier 18 is cooled by discharging a cooling gas from a cooling gas discharge pipe 35 installed in the molding chamber 20 after the pressure molding, the holding shaft is rotated by the above-described pulse motor 11 rotating in the reverse direction. Reduce 5 At this time, the release force generated by the optical contact between the upper and lower molds 21 and 22 and the optical element is reduced by the holding shaft 5.
The analog signal detected by the load cell 23 installed in the interface board is converted to a digital signal by the analog / digital converter 24, and the interface board 25
Is taken into the computer 26 via the. The computer 26 determines whether the taken-in release force data is a normal value or an abnormal value. The result of the determination is determined by the C of the control unit of the molding apparatus through the interface board 25 for each molding.
Output to PU27.

According to this embodiment, it is possible to capture the state of the release force in a time-sequential manner, make various judgments by a computer, and leave the release force data in a recording device of the computer. There is an effect that can be.

[0014]

[Embodiment 2] FIG. 2 is a schematic sectional view showing a part of this embodiment. A shaft 29 is vertically provided at the lower end of the holding shaft 5 in the vertical direction of the axis. A plate 28 having a hole through which the shaft 29 penetrates is fixed to the connecting member 15, and an electric micrometer (differential transformer type displacement meter) 33 is held at a distal end thereof. The holding shaft 5 is formed by passing a shaft 29 through a hole of the plate 28.
8 supported. An end plate 31 is provided at the tip of the shaft 29, and a spring 30 is provided on the outer periphery of the shaft 29 between the end plate 31 and the plate 28.

At the end of the end plate 31, on the same axis as the electric micrometer 33, there is provided a micrometer head 32 capable of moving the end 34 on the axis. A signal line from the electric micrometer 33 is connected to a control CPU 27 of the molding apparatus via an amplifier 36 and a comparator 37. The configuration other than the above is the same as that of the first embodiment, and the same reference numerals are given and the description is omitted.

In the molding apparatus having the above configuration, the carrier 18 on which the glass material 17 is placed is carried into the molding chamber 20 by the transfer arm 19 and is positioned between the upper and lower molding dies 21 and 22. When the loading of the glass material 17 is completed, the ball screw 12 is rotated by the pulse motor 11, and the nut 9 and the cylinder 14 connected to the nut 9 are raised along the guide shaft 7. Accordingly, the holding shaft 5 supported by the plate 28 is also pulled up, and the glass material 17 is pressed.

After the glass material or the carrier is cooled by discharging the cooling gas from the cooling gas discharge pipe 35 installed in the molding chamber 20 after the pressure molding, the plate 28 is rotated by the above-mentioned pulse motor 11 to rotate in reverse. Pull down. As the plate 28 descends, the distance between the electric micrometer 33 and the micrometer head 32 also changes (shrinks). At this time, the holding shaft 5 is provided with the upper and lower molding dies 21 and 22.
The molded position is maintained by the force generated by the optical contact between the optical element and the optical element.

When the plate 28 is lowered, the spring 30
Is contracted, and the force for pushing down the holding shaft 5 increases. When the pressing force is larger than the optical contact force, the mold is opened.

The change in the distance between the electric micrometer 33 and the micrometer head 32 is detected by the electric micrometer 33 and transmitted to the comparator 37 via the amplifier 36. The comparator 37 compares the previously recorded normal value with the transmitted value to determine the quality, and outputs information to the control CPU of the molding apparatus.

According to this embodiment, since the detection mechanism is a simple mechanism, the equipment cost can be reduced.

[0021]

As described above, according to the optical element molding apparatus of the present invention, it is possible to automatically monitor and manage the release force, which is a criterion for judging the quality in the molded state. Therefore, it is possible to quickly and accurately know the occurrence of a defective product, the damage of the mold, and the like. Therefore, it is possible to prevent a large amount of defective products from being produced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a cross section of a part showing a first embodiment.

FIG. 2 is a schematic configuration diagram in which a part of the second embodiment is shown in section.

[Explanation of symbols]

 Reference Signs List 1 base 4 movable mold 5 holding shaft 6 guide shaft support 7 guide shaft 9 nut 11 pulse motor 12 ball screw 14 cylinder 15 connecting member 16 connecting member 17 glass material 18 carrier 19 transport arm 20 molding chamber 21 upper molding die 22 lower Mold 23 Load cell 24 Analog / Digital converter 25 Interface board 26 Computer 27 CPU 28 Plate 29 Shaft 32 Micrometer head 33 Electric micrometer 35 Cooling gas discharge pipe 36 Amplifier 37 Comparator

Claims (1)

(57) [Claims] 1. An optical element molding apparatus comprising: a molding die for pressing a heat-softened glass material; a holding shaft for supporting the molding die; and driving means for moving the holding shaft forward and backward. A detecting means for detecting a releasing force after the pressing step is interposed between the driving means and the driving means, and a releasing force determining means for determining whether the releasing force detected by the detecting means is good or not. A molding device for an optical element, characterized in that: