JPH0638096Y2 - Optical element molding equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a molding apparatus for an optical element that press-molds a glass material that has been softened by heating with a pair of molding dies, and particularly, aligns the molding die and the glass material. The present invention also relates to a molding apparatus for an optical element that can be pressure-molded.

[Conventional technology]

Conventionally, as an apparatus for forming an optical glass product such as a lens by inserting and placing a heat-softened glass material between an upper mold and a lower mold, an optical glass product such as a lens is disclosed in, for example, JP-A-60-11864.
It is disclosed in Japanese Patent Publication No. 1 and Japanese Patent Laid-Open No. 64-24029.

The device disclosed in Japanese Patent Application Laid-Open No. 60-118641 is a ring-shaped conveying member in which an upper die and a lower die are slidably and coaxially opposed to each other in a sleeve, and a glass material is placed and supported. After placing the sleeve between the upper die and the lower die through the sleeve loading port, lower and raise the upper die and lower die, press the glass material while placing it on the ring-shaped conveying member, and form the press lens. To do.

The apparatus disclosed in JP-A-64-24029 is such that a collar that holds a conveying member on which a glass material is placed at the time of pressure molding is slidably fitted to the outer peripheral portions of the upper mold and the lower mold, respectively. It is constructed integrally with the elastic body, and the glass material is placed on the conveying member and positioned between the upper and lower molds, and then the lower mold is lifted to clamp the conveying member with both collars and the glass is used with the lower mold. The optical element is pressure-molded by pushing up the material and separating it from the glass material mounting surface of the conveying member.

[Problems to be solved by the device]

However, the conventional device has the following problems.

That is, in the apparatus disclosed in JP-A-60-118641, since the glass material is pressure-molded by the upper mold and the lower mold in a state where the glass material is placed in the ring-shaped conveying member, the conveying member is not limited to the upper and lower molds. There is a problem in that it is necessary to insert and arrange them while accurately positioning between them, and if the insertion arrangement is not correct, both the upper and lower molds and the conveying member come into contact with each other during pressure molding, and the mold and the conveying member are damaged. .

On the other hand, in the device of Japanese Patent Laid-Open No. 64-24029, a clearance is required to be provided between the collar and the mold in order to slidably fit the collar to the mold. When the carrying member is held by the collar during the pressure forming, the carrying member moves horizontally, and there is a problem that the axis of the mold and the glass material are displaced. Further, since the collar is attached to the mold by the elastic support, there is a problem that the collar is inclined in the clearance area when the conveying member is held, and it is difficult to perform highly accurate molding.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to prevent positional deviation between the mold and the conveying member and the glass material, prevent damage to the mold and the conveying member, and prevent the mold and the conveying member from being damaged. An object of the present invention is to provide a molding device for an optical element that can prevent misalignment with (glass material).

[Means for Solving the Problems]

In order to solve the above-mentioned problems, in a molding device for an optical element of the present invention, a heat-softened glass material is placed in a glass conveying member, and comprises an upper mold and a lower mold which are coaxially opposed to each other. In an optical element molding apparatus that press-molds with a molding die, an outer diameter portion for fitting with the cylindrical portion formed in the glass conveying member to align the lower die with the glass conveying member is formed. A centering member having a tapered portion for guiding the outer diameter portion into the cylindrical portion is formed at the tip of the outer diameter portion, and is provided around the lower die.

[Action]

According to the method for forming an optical element having the above-described configuration, when the glass material placed in the glass conveying member is pressed by the upper die and the lower die, the core is placed inside the cylindrical portion formed in the glass conveying member as the lower die is raised. The centering member is guided and inserted into the tapered portion, the outer diameter portion of the centering member and the cylindrical portion are fitted, and the lower die and the glass conveying member are centered and positioned.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a vertical cross-sectional view of a main part showing a first embodiment of an optical element molding apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes a transfer arm for holding a glass transfer member (hereinafter, referred to as a transfer member) 3 on which a glass material 2 is placed and transferring it between an upper die 4 and a lower die 5. A through hole 6 for holding the conveying member 3 is provided at the tip of the
Has been drilled. The through hole 6 is formed with a receiving portion 7 which is a stepped portion for holding (locking) the transport member 3 in the upper opening thereof. The transfer arm 1 is movable in a direction orthogonal to the axes of the upper and lower molds 4 and 5.

The conveying member 3 is formed in a substantially ring shape (or a cylindrical shape), and a flange portion 8 for engaging with the receiving portion 7 is formed on the outer upper portion thereof. The outer diameter of the transport member 3 is formed to be slightly smaller than the inner diameter of the through hole 6 so that a gap 9 is formed between the through holes 6 when the transport member 3 is held by the transport arm 1. On the other hand, a storage portion 10 for the glass material 2 is provided on the upper inside of the conveying member 3. At the lower part of the storage portion 10, a mounting portion 11 including a step portion is formed for mounting the glass material 2, and the mounting portion 11 has a diameter larger than the outer diameter of the lower die 5. Further, a cylindrical portion 12 for aligning with the lower die 5 is formed on the lower inside of the conveying member 3.

The upper die 4 and the lower die 5 are coaxially opposed to each other, and molding surfaces 4a and 5a having a shape corresponding to a desired optical element shape are formed on respective opposing surfaces of the upper die 4 and the lower die 5. . The upper die 4 and the lower die 5 are connected to a drive device (not shown) so that they can move toward and away from each other.

A ring-shaped centering ring 15 is attached to the lower die 5. The centering ring 15 is movable in the axial direction with respect to the lower mold 5 at room temperature, and is made of a material having the same or different thermal expansion coefficient as that of the lower mold so as to be integrated with the lower mold 5 at the temperature at the time of press molding. At the same time, the outer diameter portion 16 is fitted to the inner peripheral surface of the cylindrical portion 12 of the conveying member 3. Further, a taper portion 17 is formed at the tip of the centering ring 15 for absorbing the positional deviation of the axis of the conveying member 3 and the lower die 5 and facilitating the fitting of the cylindrical portion 12. .

Next, the operation of the optical element molding apparatus configured as described above will be described.

First, the glass material 2 is placed on the carrying member 3 and held in the through hole 6 of the carrying arm 1. Then, the transport member 3 is heated, and after the transport member 3 is heated to a predetermined temperature, the transport arm 1 is moved to dispose the transport member 3 on the axis of the upper die 4 and the lower die 5.

The lower die 5 integrated with the centering ring 15 is raised in association with the arrangement of the transport member 3. As the lower die 5 rises, the tip of the tapered portion 17 of the centering ring 15 is moved to the conveying member 3.
The centering ring 15 is inserted into the cylindrical portion 12 together with the lower die 5 while being in contact with the lower end of the inner circumference of the cylindrical portion 12. At the time of this insertion, the outer diameter portion 16 of the centering ring 15 and the inner peripheral surface of the cylindrical portion 12 are fitted to each other, and as shown in FIG.
(Glass material 2) is centered. After that, the lower mold 5 is further raised, and is pressed into a desired shape by the molding surfaces 4a, 5a by the molding surfaces 4a, 5a.

According to the present embodiment, when the positioning stopper for arranging the conveying member 3 at the molding position between the upper and lower molds 4 and 5 is displaced due to wear, or when the glass material 2 is heated and softened, the conveying arm is moved. When 1 was moved between the upper and lower molds 4 and 5 before reaching the predetermined temperature, the predetermined deformation due to thermal expansion of the transfer arm 1 was not obtained, and the transfer member 3 was not transferred to the molding position. Even in this case, since the taper 17 is formed at the tip of the centering ring 15, it is possible to absorb the molding position deviation of the conveying member 3.

(Second Embodiment) FIG. 3 shows a second embodiment of an optical element molding apparatus according to the present invention. FIG. 3A is a vertical sectional view of a molding die, and FIG. 3B is an enlarged sectional view of an essential part. It is a figure.

The feature of this embodiment is that the centering ring 20 fitted to the lower mold 5 is used.
The taper portions 21 and 22 are formed in two steps in the axial direction from the tip to the tip. Since the other construction is the same as that of the first embodiment, the same parts are designated by the same reference numerals and the description thereof will be omitted. The illustration will be omitted and the reference numerals of FIG. 1 will be used.

In this embodiment, the transport member 3 is transported to the molding position by the transport arm 1 and the lower die 5 is raised, and first, the transport member 3 is guided by the taper portion 21 at the tip of the centering ring 20, and then the transport member 3 is guided. The lower stage 5 and the conveying member 3 are aligned with each other by being guided to the fitting portion of the centering ring 20 by the second taper portion 22.

Therefore, according to this embodiment, two tapered portions 21 and 22 are formed in the axial direction from the tip of the centering ring 20, and the tapered portion 21 formed at the tip is the second tapered portion. Since the diameter is smaller than 22, it is possible to cope with a large molding position deviation of the conveying member 3 and perform accurate fitting and centering.

(Third Embodiment) FIG. 4 shows a third embodiment of an optical element molding apparatus according to the present invention, and is a longitudinal sectional view of a molding die in the drawing.

The feature of the present embodiment is that the centering ring portion 33, which is composed of a taper portion 31 having the same function as that of the centering ring 15 and a large diameter portion 32 which is fitted with the conveying member 3 to perform centering, is integrated into a lower mold. This is the point that constituted 30. That is, a large-diameter portion 32 having a diameter larger than the outer diameter of the molding surface 30a at a position away from the molding surface 30a of the lower mold 30 by a required length.
Forming a taper part 31 at the tip of the large diameter part 32
30 are made up.

According to this embodiment, the lower die 30 and the conveying member 3 can be fitted and centered as in the first embodiment. Further, since the lower die 30 is configured by integrating the centering ring portion 33, there is no clearance between the lower die 5 and the centering rings 15 and 20 as in the above embodiment, and accurate centering can be performed.

[Effect of device]

According to the optical element molding apparatus of the present invention, when the glass material is pressed by the molding die, the lower die and the glass conveying member can be aligned by the centering member, so that the core of the molding die and the glass material is aligned. It is possible to form a high-precision optical element by taking out. Further, since the tapered portion is formed at the tip of the centering member, when the molding position of the glass conveying member is displaced by the conveying arm, the displacement can be absorbed, and the molding defect and the molding die and the glass due to the displacement can be absorbed. It is possible to prevent damage to both due to contact with the transport member.

[Brief description of drawings]

1 and 2 show a first embodiment of a molding apparatus for an optical element according to the present invention. FIG. 1 is a longitudinal sectional view showing a main part of the molding apparatus, and FIG. 2 is a lower mold and a conveying member. FIG. 3 is a longitudinal sectional view showing a state in which the optical element is fitted and aligned, FIG. 3 shows a second embodiment of an optical element molding apparatus according to the present invention, and FIG. 3a is a vertical section showing a main part of the molding apparatus. FIG. 3 is a plan view showing an enlarged sectional view of an essential part, and FIG. 4 is a longitudinal sectional view of an essential part showing a third embodiment of the optical element molding apparatus according to the present invention. 2 …… Glass material 3 …… Glass conveying member 4 …… Upper mold 5 …… Lower mold 15 …… Centering member 16 …… Outer diameter part 17 …… Tapered part

Claims (1)

[Scope of utility model registration request] 1. A molding apparatus for an optical element, wherein a glass material which has been softened by heating is placed in a glass conveying member, and is press-molded by a molding die composed of an upper mold and a lower mold which are coaxially opposed to each other. The tapered portion for fitting the cylindrical portion formed in the member to form an outer diameter portion for centering the lower die and the glass conveying member and for guiding the outer diameter portion into the cylindrical portion is provided. An optical element molding apparatus, wherein a centering member formed at the tip of the outer diameter portion is provided around the lower mold.