JPH04331725A - Method for releasing glass lens from mold - Google Patents

Abstract

PURPOSE:To provide a method for releasing a glass lens from a forming mold in which transfer with a high accuracy is obtained without providing a temperature distribution onto the forming mold surface. CONSTITUTION:The subject method is a method for forming a glass lens 3 by press forming a previously heated and softened glass material with a top force 1 and a bottom force 2. In the aforementioned method, the outer peripheral surface of the lens 3 to be formed is formed with a pair of the top and the bottom forming forces, oppositely arranged on the same axial line and having a squeeze-out part for the excessive glass material or the forming surface of a vertically movable mold releasing sleeve 6, fitted and formed on the outer periphery of either of the top force 1 and the bottom force 2 in the forming mold. Thereby, a flange part for releasing the lens 3 to be formed from the forming mold is integrally formed on the outer periphery of the lens 3 to be formed on the outside of an effective diameter of the lens 3 to be formed with the pair of the top and the bottom forming forces and the forming surface of the mold releasing sleeve 6. A pressure is simultaneously applied from the top surface of the flange part for the aforementioned mold releasing to release the glass lens 3 from the forming mold.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold release method for releasing a molded article formed by press molding an optical element such as a glass lens from a mold.

0002

[Prior Art] Recently, a document disclosing a method for releasing a molded article formed by press molding an optical element such as a glass lens from a mold is published in Japanese Patent Laid-Open No. 63-15.
There is a publication No. 6022. In the mold release method disclosed in this publication, a conduit is provided that is opened at a portion other than the molding surface that forms the optically functional surface, and high-pressure gas is supplied to this conduit to release the molded product adhering to the mold. This is a technique that is similar to molding.

[0003] In the technique disclosed in the above-mentioned publication, since an open conduit is provided in the mold at a portion other than the molding surface that forms the optically effective surface, the temperature around the conduit becomes low. Therefore, there was a problem in that uniform shrinkage of the glass material during press molding was prevented, making it difficult to obtain precise transferability.

0004

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is aimed at obtaining high transfer accuracy in precise press molding without providing temperature distribution on the mold surface. It is an object of the present invention to provide a method for releasing a glass lens made from a mold.

[0005]

[Means and effects for solving the problems] The present invention provides a glass lens forming method in which heat-softened glass material is press-molded using a pair of molds, in which excess glass material protrudes from oppositely arranged glass materials on the same axis. By forming the outer circumferential surface of the lens to be molded with the molding surface of the molding die having a molding die having a part and the molding surface of a mold release sleeve that is configured to fit around the outer periphery of one of the molding molds of the pair of molding molds, the effective The release flange part of the lens to be molded is integrally molded on the outer periphery of the lens to be molded using the molding surface of the mold and release sleeve outside the diameter, and pressure is applied from the upper surface of the release flange part to release the glass from the mold. This is a method of releasing a glass lens from a mold.

[0006]

[Embodiment 1] An embodiment of the glass lens mold release method of the present invention will be explained based on the drawings. FIG. 1 is a sectional view from the front showing essential parts of Example 1 of the mold release method for glass lenses of the present invention. FIG. 2 is an operational cross-sectional view of essential parts showing a mold release state that has been moved from the state of FIG. 1. FIG. 3 is an operational sectional view of essential parts showing a mold release state by a mold release method different from the mold release state of FIG. 2.

Reference numerals 1 and 2 shown in FIG. 1 are an upper mold and a lower mold formed into a cylindrical shape for press-molding the molded biconvex glass lens 3, and configured to move up and down on the same axis. . Opposing surfaces of the upper mold 1 and the lower mold 2 each have molding surfaces 4 and 5 formed to have a desired mirror finish for press molding the glass lens 3.

A cylindrical mold release sleeve 6 is fitted onto the outer periphery of the upper mold 1 and configured to slide the upper mold 1 in the vertical direction. A groove-shaped channel 7 is formed on the inner periphery of the lower end of the mold release sleeve 6 to a desired depth, and through which gas such as gas is fed during mold release. That is, the outer diameter surface of the molded lower end surface of the glass lens 3 to be molded is configured to be flush with the lower end surface of the mold release sleeve 6, and the pressure gas to be supplied is set to a depth that uniformly fills the flow path 7. A flow path 7 is formed at the position. Further, a gas jet nozzle 8 is connected to a gas supply means provided outside by forming a hole between the deep portions of the flow path 7 on the outer circumferential surface of the mold release sleeve 6. Further, a molding surface 9 for molding the outer diameter surface of the glass lens 3 to be molded is formed on the inner peripheral surface of the release sleeve 6, that is, on the outer peripheral surface of the flow path 7.

Next, a method of molding and releasing a glass lens 3 using the upper mold 1 and lower mold 2 having the above structure will be explained. First, the upper mold 1 and the lower mold 2 are moved vertically to create a desired interval between the molds, and softened glass that has been heated and softened in advance is supplied onto the molding surface 5 of the lower mold 2 between the intervals. Then, the softened glass is press-molded by moving the upper mold 1 and the lower mold 2. Due to this pressing, the glass lens 3 is molded by the molding surfaces 4 and 5 of the upper mold 1 and the lower mold 2, and the molding surface 9 of the mold release sleeve 6.

Thereafter, the glass lens 3 formed between the upper mold 1 and the lower mold 2 is released. In this case, first, lower mold 2
By moving the glass lens 3 downward, the molding surface 5 of the lower mold 2 and the glass lens 3 are released from the mold. Next, a gas supply device (not shown) is driven to supply N from the gas jet nozzle 8.
2, Inert gas such as Ar2, He2 gas (N2 gas is shown in the figure)
), the gas is ejected from the gas ejection nozzle 8 into the flow path 7 to fill it. The gas in the filled flow path 7 is applied as a pressing force by the upper surface of the excess outer peripheral portion protruding from the outer peripheral edge of the glass lens 3, and the glass lens 3 is released from the molding surface 4 of the upper mold 1. The released glass lens 3 is placed on the left and right sides (Fig. 2
) and is transported to the outside.

In the above embodiment, the molded glass lens 3 is released from the mold by moving the lower mold 2 downward, and then the upper mold 1 is moved upward to release the mold, and at the same time, inert gas is injected from the gas jet nozzle 8. Although the mold is released in the order of ejecting and releasing from the mold release sleeve 6, the order is not limited to the above, and as shown in FIG. 3, the upper mold 1 moves upward and the lower mold 2 moves downward. After the molding surfaces 4 and 5 are released from the molds by simultaneous movement, the gas supply device is driven to jet out inert gas from the gas jet nozzle 8, and the molding surfaces are dropped onto the transport arm 10 and transported to the outside. It's okay.

0012

[Embodiment 2] Embodiment 2 of the present invention will be described based on FIG. FIG. 4 is a sectional view from the front showing a main part of Example 2 of the mold release method for a glass lens of the present invention. In the drawings, the same configurations and members as in the first embodiment are designated by the same reference numerals, and their explanations will be omitted.

As shown in the figure, a cooling device for cooling the excess outer periphery of the molded glass lens 3 is placed around the outer periphery of the lower end of the mold release sleeve 6 which is fitted onto the outer periphery of the upper mold 1. A cooling ring device 12 including a pipe 11 is integrally installed. Although not shown, the base end of the cooling ring device 12 is connected to an external device that supplies a cooling medium such as Freon, and air is sent into the cooling pipe 11 to release the mold release sleeve 6. It is configured to cool the molded glass lens 3 through the lens.

This embodiment with the above configuration is similar to the embodiment 1 described above.
After molding using the same molding method as above, the glass lens 3 is released from the molding surface 4 of the upper mold 1 and the molding surface 5 of the lower mold 2, and then the cooling supply device is driven to supply gas such as fluorocarbon to the cooling ring. 1
By supplying air into the mold release sleeve 6, the mold release sleeve 6 is cooled. This cooling cools the molding surface 9 of the mold release sleeve 6, making it easier to release the glass lens 3 from the molding surface 9, and then the mold is released and then the mold is released by blowing out inert gas. .

[0015]

[Embodiment 3] Embodiment 3 of the present invention will be explained based on FIG. FIG. 5 is a sectional view from the front showing essential parts of Example 3 of the glass lens mold release method of the present invention. In the drawings, the same configurations and members as in the first embodiment are denoted by the same reference numerals as in the second embodiment, and the explanation thereof will be omitted.

As shown in the figure, the outer periphery of the lower end of the upper mold 1 is stepped at a position where inert gas can be ejected from the connection port of the gas ejection nozzle 8 when the molded glass lens 3 is released from the mold. A porous ring 14 is formed on the stepped portion 13.
is integrally attached and configured to slide vertically with the inner periphery of the mold release sleeve 6, and the excess outer periphery of the molded glass lens 3 is separated by application of gas jet pressure. Configured to type. The other configurations are the same as those of the first embodiment, and will therefore be omitted.

Note that in the above structure, the porous ring 14
It is made of heat-resistant materials such as alumina and mullite. In addition, the diameter dimension of the press molding surface 4 of the step portion 13 formed on the outer periphery of the upper mold 1 in the above configuration is as follows:
The optical effective diameter dimension of the glass lens 3 to be molded is formed to a dimension.

According to this embodiment having the above-mentioned structure, the molding is carried out using the same molding method as in the first embodiment, and the upper mold 1 is arranged so that the inert gas is jetted from the gas jetting nozzle 8 at the time of mold release.
Since the protruding excess outer circumferential portion of the glass lens 3 molded through the porous ring 14 integrally formed with the glass lens 3 is released from the mold by gas pressure, the outer diameter of the glass lens 3 is not formed to be larger than necessary. It has the advantage that it is not necessary.

[0019]

[Effects of the Invention] According to the present invention with the above configuration and method,
The molded glass lens is released from the mold by applying pressure to the outer diameter edge surface of the glass lens using the gas ejection means of the mold release sleeve provided on the outer periphery of the mold, thereby making the temperature distribution on the mold surface uniform. This has a great effect in that precise transfer can be performed and high-quality optical elements can be molded with high productivity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view from the front showing essential parts of Example 1 of the glass lens mold release method of the present invention.

FIG. 2 is an operational sectional view of essential parts showing a mold release state transitioned from the state of the method shown in FIG. 1;

FIG. 3 is an operational cross-sectional view of essential parts showing a mold release state according to another mold release method, which is different from the mold release state shown in FIG.

FIG. 4 is a sectional view from the front showing essential parts of Example 2 of the glass lens mold release method of the present invention.

FIG. 5 is a cross-sectional view from the front showing essential parts of Example 3 of the glass lens mold release method of the present invention.

[Explanation of symbols]

1 Upper mold 2 Lower mold 3 Glass lens 4,5　Press molding surface 6 Release sleeve 7 Flow path 8 Gas jet nozzle 9 Molding surface 10 Transfer arm 11 Cooling pipe 12 Cooling ring device 13 Stepped section 14 Porous ring

Claims (1)

[Claims] 1. A method for forming a glass lens in which a glass material softened by heating is press-molded using a pair of molds, comprising: a mold which is disposed facing each other on the same axis and has a protruding portion for excess glass material during molding; and the pair of molds. By molding the outer peripheral surface of the lens to be molded with the molding surface of the mold release sleeve that is fitted to the outer periphery of one of the molds, a pair of molds and a mold are formed outside the effective diameter of the lens to be molded. The mold release flange part of the molded lens is integrally molded on the outer periphery of the molded lens on the molding surface of the mold release sleeve, and pressure is applied from the upper surface of the mold release flange part to release the glass lens from the mold. A method for releasing a glass lens.