JPS6110034A - Glass press lens and pressing machine therefor - Google Patents

Abstract

PURPOSE:When a glass lens is formed by pressing a gob in a compression mold, the periphery of the effective aperture is provided with a part which is regulated by the mold and the rest part which does not undergo any restriction in an open state to keep the thickness of the lens pressed constant. CONSTITUTION:In a glass lens pressing machine, a gap D1 is formed partially along the periphery of the lens openly between male mold 16, female mold 17 and drum mold 18. A lump of softened glass (gob) is pressed with a molding machine consisting of male mold 16, female mold 17 and drum mold 18 to form a lens with a part of the periphery which is regulated by the mold 13 and rest part which is not restricted 14. Thus, glass lenses of constant thickness 11 are formed, even when gobs fluctuate in weights, because excess amounts of gobs are made to flow out of the gap D1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a glass press lens that is molded from a softened glass gob by pressing with a mold, and to an apparatus for molding the same.

(Prior Art) For example, glass press lenses used for eyeglasses, binoculars, etc. are manufactured by flowing molten glass through an outlet and supplying gobs cut into approximately equal weights to a molding device.

FIGS. 1(8) and 2 are sectional views of essential parts showing an example of a conventional glass press lens molding apparatus of this type. In the figure, numeral 1 is a gob of softened glass.

Reference numeral 2 designates an upper die, 6 a lower die, 4 a body die, 5 a push-up rod for pushing up the lower die 3, and 6 a gob shooter for dropping the gob 1 cut into a predetermined amount into the body die 4. The body mold 4 is fixed, and the upper mold 2. Lower mold 3
are arranged so as to be vertically movable on the same central axis. Then, in the state shown in FIG. 1, that is, with the upper die 2 being pulled upward and the lower die 3 being at the lowest position in the body die 4, one gob 1 is inserted into the body die 4 from the gob seater 6. When the gob is dropped, as shown in FIG. 2, the upper die 2 is pushed down and the gob 1 is pressed into a predetermined shape to form a single glass press lens. After the molding process is completed, the upper mold 2 is pulled upward, and then the lower mold 3 is pushed up by the push rod 5, and the gob 1, which has been molded into one glass press lens, is taken out from the body mold 4. It has become.

However, in glass press lenses molded by such conventional molding equipment, variations in the heavy wheels of the gob 1 appear as variations in the wall thickness of the trench press lens, and this affects the optical properties of the lens. It had the serious drawback of affecting the

(Objective) In view of the above-mentioned points, the object of the present invention is to ensure that even if there is variation in the weight of the gob, it does not affect the thickness of the press lens.
The purpose of the present invention is to provide a glass press lens and a molding device for the same.

(About 1jI) In order to achieve the above object, the present invention provides a gap between the upper and lower molds and the body mold of a molding device that does not restrict a part of the body circumference of the glass press lens, and in this empty N part, excess gob is removed. The wall thickness of the glass press lens will be constant after pouring 5Kl,
It is characterized by:

(Example) Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 3 is a cross-sectional view of a glass press lens showing an example @1 of the present invention, and FIG. 4 is a cross-sectional view of a main part of a molding apparatus for molding the glass press lens of FIG. 3. The glass press lens 11 in this embodiment is a biconvex lens with a completely curved surface, and as shown in FIG.
The circumferential surface of the barrel in contact with 2b is a regulated peripheral part 13 whose outer diameter is equal to the effective aperture of the lens 11, and the upper surface 1
The outer diameter of the trunk circumferential surface in contact with 2JI is slightly larger than the outer diameter of the regulated periphery 13 and the open periphery 14 whose outer diameter is not regulated.
It becomes.

On the other hand, the molding device 15 for molding the glass press lens 11 is as shown in FIG. IC, upper mold 16° lower mold 17. The body mold 18 is the upper mold 2 of the molding apparatus shown in FIGS. 1 and 2, respectively. Lower mold 3. It is constructed almost the same as the body type 4, and its function is also almost the same. However, the outer diameter of the upper mold 16 is slightly larger than the inner diameter of the body mold 18, and the lower mold 17 is fitted into the body mold 18 with a sliding nL, and the lowest position of the lower mold 17 is placed in a glass press. The Q gob 11A for the lens 11 is fixed to the body mold 18 so that there is enough space for it to fit properly even if it is inserted into the adjustment mold 18. The body mold 18 and the upper and lower molds 16 and 17 are held within a predetermined eccentricity on the same central axis, and
The distance between the molds 16 and 17 between the lowest press position of the upper mold 16 and the fixed position of the lower mold 17 to the body mold 18 closely matches the thickness of the glass press lens 11 to be processed. It is defined as follows. Furthermore, at the lowest position of the upper mold 16, as shown in FIG.
The upper and lower molds 16, 17 are located within this gap D1.
The gob 11A is shaped like a sail so that the excess amount of the gob 11A pressed by the k is pushed out.

The method of molding the glass press lens 11 using the molding apparatus 15 of the present invention constructed as described above is almost the same as that of the molding apparatus shown in FIGS.

As described above, even if the weight of the gob IIA varies, the thickness of the molded glass press lens 11 is constant. Therefore, this type of conventional drawback has been successfully solved, and since the regulating peripheral portion 15 of the press lens 11 serves as an accurate point for subsequent processing and assembly of the lens, the processing is completed and the assembled lens is Performance can be further improved.

Further, it can be used for axial positioning of the glass press lens 11 according to the present invention. That is, FIG. 5 shows an example in which the glass press lens 11 is assembled into a lens holding frame by skillfully utilizing the above-mentioned right angle portion. As shown in FIG. 5, the inner surface of the central portion of the lens holding frame 19 has a regulating peripheral portion 13 of the press lens 11.
A fitting part 19a into which the fitting part 1 is fitted is provided.
A circumferential groove 19b into which the release peripheral portion 14 enters is formed near the rear of VCG 9a. And the same circumferential groove '19b
As is well known, the rear part of the lens holder M20 is screwed into the lens holder 5 to fix the press lens 11 to the lens frame 11C. As is clear from this figure, when the regulating peripheral part 15 of the press lens 11 is precisely fitted into the fitting part 19a of the lens holding frame 19, the front surface of the releasing peripheral part 14 of the press lens 11 is the lens holding frame 19. By abutting against the step part of the circumferential groove 19b of the frame 19, the press lens 11
The position in the zero optical axis direction is also precisely determined and the lens 11 is fixed.

FIG. 6 is a sectional view of a glass press lens according to a second embodiment of the present invention, and FIG. 7 is a sectional view of essential parts of a molding apparatus for molding the glass press lens shown in FIG. 6.

The glass press lens 21 in this embodiment is also entirely curved to satisfy optical performance, and is a concave-convex lens with an upper surface 22a having a convex surface and a lower surface 22b having a concave surface. A ring-shaped peripheral wall protruding upward from the peripheral edge of the upper surface 22a serves as an open peripheral portion 24. Book! i! The press lens 21 in the example is
In contrast to the press lens 11 in the previous embodiment in which the variation in the weight of the gob was adjusted by the release peripheral part 14 in the circumferential direction, the adjustment is made by the release peripheral part 24GC facing upward on the circumferential surface. It is.

As shown in FIG. 7, a molding device 25 for molding such a glass press lens 21 includes a fixed cylindrical sub-mold 28, and a body mold 28 which is inserted into the body mold 28 from above so as to be vertically movable. It is constructed of an upper mold 26 having an outer diameter smaller than the inner diameter of the tuning mold 28, and a lower mold 27 that fits into the lower part of the tuning m2B so as to be movable up and down.・Upper nC upper and lower type 26,
27 and the sub-mold 28 are arranged so that their central axes coincide with each other, and are not strictly held within a predetermined eccentricity. Then, the state shown in Figure 7,
That is, the distance between the predetermined position where the upper die 26 is pressed down and the lower die 27 at this time is strictly regulated, and the thickness of the gob 21A formed from this K is constant, and the thickness of the gob 21A formed from this K is constant.
As shown in the figure, the excess amount is the upper mold 26 and! pI type 2
Between 8 and 1! JiD, K seems to be pushed inwards. This extruded ring-shaped protrusion forms the open peripheral portion 24. This open peripheral portion 24 will be ground later. The other functions of the molding device 25 are exactly the same as those of the molding device 15 shown in FIG. 4 above, so a description thereof will be omitted to avoid duplication.

Further, the unique effect of the lens of this second embodiment is that since there is no protruding open peripheral part on the outer periphery of the molded glass press lens 21, there is no need to provide a peripheral groove etc. for this purpose in the lens holding frame. The diameter of the lens holding frame can be reduced accordingly.

In this embodiment, the lower surface 22b of the lens is entirely curved, but if the effective diameter is small, the periphery thereof may be made flat. In addition, the molding device 2 of this m2 embodiment
If the inner surface of the sub-mold 28 at 5k is formed into a loose tapered shape, the mold release operation of the lens becomes easier.

FIG. 8 is a sectional view of a glass press lens according to a third embodiment of the present invention, and FIG. 8 is a sectional view of a main part of a molding apparatus for molding the glass press lens of FIG. 8. The glass press lens 31 of this embodiment is also a fully curved lens that satisfies optical characteristics, and is a biconcave lens with concave upper and lower surfaces 52a and 52b, and a ring-shaped protrusion in the center of the outer surface [the above-mentioned open periphery]. A portion 54 is formed, and its upper and lower surfaces constitute the above-mentioned regulating peripheral portions 55a and 53b. In this way, in this embodiment, the glass press lens 31
By providing the regulating peripheral parts 55a and 55b on the upper and lower sides of the curved part, the press lens 51 can be positioned in the optical axis direction with two contact surfaces with respect to the lens holding frame (not shown). ing.

A molding device 35 for molding such a glass press lens 31 is configured as shown in Figure @9.

That is, the upper mold 56. Lower mold 57. Guide member 58. Lower peripheral regulating member 39. and an upper peripheral regulating member 40.

The guide member 38 has a cylindrical shape and is fixed to an immovable member, and the lower periphery regulating member 39 made of a relatively thin cylinder is slidably fitted into the lower part of the guide member 38. The lower mold 37 is slidably fitted into the lower periphery regulating member 39. Also, guide kidnapping 3
The upper peripheral regulating member 40 made of a relatively thick cylindrical body is slidably located above the inner part 8, and the upper die 36 is slidably fitted into the upper peripheral regulating member 40. are doing. The inner surface of the upper end of the guide member 68 is tapered as shown in the figure so that the upper peripheral regulating member 40 can be easily inserted therein. Further, a glass press lens 61 is provided on the inner surface of the lower end of the upper peripheral regulating member 40.
A step portion 56a is provided so that the upper surface periphery thereof is formed at a right angle. the upper and lower peripheral regulating members 39;
40 and the upper and lower molds 56 and 57 are the center l of the guide member 38
1tlI! The upper and
The intervals when the lower molds 36 and 37 are pressed are also constant. However, at this time, each of the upper and lower peripheral regulating members 59
, 40 are arranged so that each can independently move up and down so that the gap D3 can be changed. These are the restricted peripheral parts 53a, 33b and the open peripheral part 3 of the press lens 31.
This is to enable KaAIJt to be optimal for the lens holding frame (not shown) K.

The operation of the molding device 35 in this embodiment, which is made by $1.
5, but the only difference is that the upper and lower peripheral regulating members 59 and 40 are present. That is, the upper mold 66 and the upper periphery regulating member 40 are pulled upward from the state shown in FIG. The gob 51A is then inserted into the guide member 38 from above while being fixed within the guide member 68. Next, the integrated upper mold 36 and the peripheral regulating member 40 are pushed down, and the integrated lower mold 3
7 and the lower peripheral regulating member 39
People are molded. At this time, the extra gobscape is the gap D8 above.
It bulges inward. After molding, the upper peripheral regulating member 40 first slides upward, and then the upper mold 56 is pulled upward.
From the upper end of the opened guide member 38, move the 31 gobs that have become the glass press lens 31 to the lower periphery mrlJ.
It can be taken out by pushing up with a member 39.

Further, the unique effect of the lens of the third embodiment is that by using the regulating peripheral parts 55a and 55b formed above and below the open periphery @54 on the peripheral surface of the lens 310, the first embodiment') 4(
') and l'J, the glass press lens 31 can be easily positioned in the optical axis direction with respect to the lens holding frame.

(Effects) As explained above, according to the present invention, the variation in lens thickness caused by the variation in the weight of the gob, which conventional glass press lenses of this type had, is eliminated, and The optimum contrast for subsequent lens processing and frame insertion can be obtained at the same time when molding the lens curved surface, and the performance of the lens can be further improved.

In each of the above-mentioned embodiments, both surfaces are curved glass pressed lenses, but it goes without saying that the present invention can also be applied even if one of the surfaces is flat.

[Brief explanation of the drawing]

1st. FIG. 2 is a main part wfrrf1 diagram showing the operation am of a conventional glass press lens molding device, and FIG.
A cross-sectional view of a glass press lens showing the first embodiment of the present invention; FIG. 4 is a cross-sectional view of a main part of a molding apparatus for molding the glass press lens shown in FIG. 3 above; FIG. FIG. 6 is a cross-sectional view of a glass press lens showing a second embodiment of the present invention; FIG. FIG. 8 is a cross-sectional view of a glass press lens showing a third embodiment of the present invention; FIG. 9 is a cross-sectional view of the glass press lens shown in FIG. 8. FIG. 2 is a sectional view of a main part of a molding device that molds a lens. 11.21,31...War glass press lens 13.2
5.53...Regulation peripheral part 14.24, 34...Release peripheral part 15.25.35...Fist glass press lens molding device 16.26.36...Upper mold 17.27 ．57・・・Bottom mold 18, 28・φ・・Body mold Applicant Olympus Optical Industry Co., Ltd. Tsuta 1
Picture horse 5 picture departure 6 ward tsuta picture 8 picture etc.

Claims (2)

[Claims] (1) In a glass press lens formed from a softened glass gob by pressing with a mold, the periphery of the effective aperture has a regulated periphery regulated by the mold and an open periphery that is not regulated. A glass press lens featuring: (2) In a glass press lens device that presses a softened glass gob (gob) with a mold consisting of an upper mold, a lower mold, and a body mold to form a glass press lens, the glass press lens is placed between the upper mold and the body mold. A molding device for a glass press lens, characterized in that a gap for an open peripheral portion is provided that does not restrict a part of the circumference of the glass press lens.