JPH04450B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method and apparatus for molding a framed lens, and more particularly to a method for molding a glass lens having a plastic lens frame, etc., and a molding apparatus used in the method. (Mold) related.

Conventional technology and problems Conventionally, in order to manufacture glass lenses with plastic frames and barrels, so-called framed lenses, a lump of softened glass is divided into an upper mold (movable mold) and a lower mold (fixed mold). A glass lens is preformed by pressure molding using a lens molding mold consisting of a mold, and then this glass lens is placed in a frame molding mold comprising a fixed mold and a movable mold, and the peripheral part of the glass lens is injected. It is integrally molded with a molded plastic mirror frame.

However, in the case of using the above method, steps such as taking out the glass lens from the lens molding mold, cleaning the glass lens, transporting the glass lens to the frame molding mold, and storing the glass lens are required, and the manufacturing process In addition, there is a problem that the glass lens may be damaged during the transportation process or the storage process, or there is a problem that the accuracy of centering the glass lens with respect to the frame molding die is decreased.

Furthermore, as a molding device (mold) used in the above method, one described in Japanese Patent Publication No. 14126/1982 is known.

This molding device manufactures a so-called framed lens in which a plastic lens frame 2 is integrally molded around the outer periphery of a glass lens 1. As shown in FIG.
A hole 5 is provided in the template 3 that passes perpendicularly to the land 4, and a fixed lens holder 6 is inserted into the hole 5.
A fixed mold 7 for frame forming into which is fitted, two template plates 8,
9, and a bottomed hole 11 perpendicular to the land 10 that collides with the land 4 of the fixed mold 7 for frame forming is bored therein, and a glass lens is inserted into the bottomed hole 11 together with the fixed lens holder 6. It consists of a frame-forming movable mold 13 into which a movable lens holder 12 for bell-clamping (automatic centering) 1 is slidably inserted while resiliently biasing it toward a land 10.

In order to manufacture a framed lens using the above-mentioned molding device, first, the glass lens 1, which has been molded in advance by a separate lens molding device, is placed on the fixed lens holder 6, and then bell-clamped by the movable lens holder 6. Center and position. Next, the hole 5 of the template 3, the fixed lens holder 6, the bottomed hole 11 of the template 9, and the movable lens holder 1.
When plastic is injection molded into the space (cavity) 14 formed by the lens 2 and the glass lens 1, a lens with a frame is completed.

In FIG. 1, reference numeral 15 is a spring that elastically biases the movable lens holder 12, and reference numeral 16 is a lens holding pin movably inserted into the center of the movable lens holder 12.
7, it is elastically biased in the same direction as the movable lens holder 12. Further, 18 is a runner provided on the lands 4 and 10 of the fixed and movable molds 7 and 13 for frame forming, and is used to connect the cavity 1 through the gate 19.
It is connected to 4. Furthermore, 20 is an ejector pin fitted into the fixed lens holder 6, and this ejector pin 20 is interlocked and connected to a return pin 21 slidably fitted into the template 3 via plates 22 and 23. It is.

However, since the above-mentioned molding device automatically centers the glass lens 1 which has been molded in advance by a separate lens molding device by fixing it and sandwiching it between the movable lens holders 6 and 12, the effective diameter of the glass lens 1 is fixed. There is a risk of scratches, etc. on the lenses, and since the bell clamp method is used for centering, lenses that are difficult to center, that is, the so-called Z
There are problems such as it cannot be applied to lenses with low values.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a method and apparatus for molding a framed lens that can manufacture various types of high-quality framed lenses in a small number of steps.

Structure of the Invention The present invention has been made to achieve the above-mentioned object, and the first invention provides a glass glass having a protrusion on the outer periphery of the effective diameter portion by pressure-molding a lump of softened glass using a lens molding die. While molding the lens, the lens mold and the glass lens are cooled to a predetermined temperature while the glass lens is held between the glass molds, and then the lens mold and the glass lens are cooled to a predetermined temperature. Plastic is injection molded using a frame molding die that forms the cavity, and the plastic frame is integrally molded with the flange.

Further, the second invention provides a fixed mold for lens molding and a movable mold in which a land surrounding the cavity is formed into a small width and a tapered surface is continuously provided on the outer periphery of the land, which are arranged oppositely on the same axis, and the fixed mold for lens molding is arranged oppositely on the same axis. , a pair of frame molding molds having a land provided with a concave portion around the movable mold that engages with a half of the outer periphery of each mold, and a cavity formed by surrounding each mold in the concave portion; They are arranged facing each other so that they can approach and leave at right angles to the moving direction of the movable mold for molding.
A glass lens with a rim formed by a fixed and movable mold for lens molding is molded integrally with the rim using a pair of frame molding molds without removing it from the fixed and movable mold for lens molding. This is how it was done.

Furthermore, the third invention provides a fixed mold for lens molding, in which a land surrounding the cavity is formed with a small width at the center of the bottom of the cavity provided on the land of the fixed mold for frame molding, and a tapered surface is continuously provided on the outer periphery of the land. A movable mold for lens molding, which is erected and faces the fixed mold for lens molding and has a narrow land formed to surround the cavity and has a tapered surface connected to the outer periphery of the land, is disposed on the same axis, and The movable mold for frame molding has a cavity on the land that corresponds to the cavity of the fixed mold for frame molding, and the movable mold for frame molding can be slid freely through a hole perpendicular to the land penetrated through the center of the bottom of the cavity. At the same time, it is elastically biased toward the fixed mold for frame molding and installed, and similarly to the second invention, the glass lens with a rim is attached to the fixed mold for frame molding without taking it out from the movable mold for frame molding. The plastic frame is integrally molded with the flange.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like.

First, in order to manufacture a lens with a frame, the molded glass is heated using a heating means such as a heater.
It is heated to a temperature of 10 ¹⁴ to 10 ¹⁰ poise (this temperature varies depending on the molded glass material; for example, in the case of SFS01, it is 300 to 500°C).

Then, a lump of glass softened to a viscosity of 10 ⁷ to ^{10 5.5} poise is placed in a lens mold, and this is pressure-molded to form a radially protruding flange on the outer periphery of the effective diameter. Form a glass lens with

Thereafter, the glass lens is held between the lens molds and the pressure applied to the glass lens is reduced while the lens mold and the glass lens are heated to the plastic molding temperature (this temperature is determined by the plastic material). For example, in the case of polycarbonate, the temperature is about 100°C.).

Then, the cavity (space) formed by the rim of the glass lens, the lens mold that holds the glass lens, and the frame mold that surrounds the lens mold.
Then, plastic is injection molded and the plastic frame is integrally molded with the rim of the glass lens.

Finally, after lowering the molding temperature of the lens mold, glass lens, frame mold and frame by 2 to 30 degrees Celsius from the plastic molding temperature, support the lens with frame with an ejector pin etc. When the mold is opened and the framed lens is taken out, the framed lens is completed.

2 and 3 are longitudinal and transverse cross-sectional views showing an embodiment of the second invention. In the molding apparatus of this embodiment, a fixed die (lower die) 24 and a movable die ( The upper molds 25 are provided in a cylindrical shape and are arranged facing each other on the same axis. These fixed and movable molds 24 and 25 are connected to respective lands 24 and 25.
semicircular cavities 24b, 25b forming the outer shape of a glass lens to be described later are provided in a, 25a, and lands 24a, 25a surrounding each cavity 24b, 25b are formed with a small width, and the lands 24a, 25a are Linear tapered surfaces 24c and 25c are connected to the outer periphery to form a protruding edge of the glass lens as described later.

On the outer peripheries of the fixed and movable lens molding molds 24 and 25, a pair of frame molding molds 26 and 27 are attached to each other in a direction perpendicular to the moving direction (vertical direction in FIG. 2) of the movable lens molding mold 25. The lands 2 of each frame molding mold 26, 27 are arranged so as to be able to approach and separate.
6a and 27a are fixed and movable molds 2 for lens molding.
A semicircular recess 26b that engages with the outer periphery of 4 and 25,
27b is provided. Then, each recess 26b, 2
7b, cavities 26c and 27c into which plastic is injection molded as described later are formed to surround fixed and movable molds 24 and 25 for lens molding.

The cavities 26c and 27c of the respective frame molding molds 26 and 27 are connected to the runners 26d and 27d provided on the lands 26a and 27a and the gates 26e and 27.
They are connected via e. In addition, the cavities 26c, 27c of each molding mold 26, 27
Two ejector pins 28 and 29 are provided in each of the frame molding molds 26 and 27 so as to be retractable and extend in the same direction as the respective moving directions.

Next, we will discuss the effects of the above configuration in Figures 2 to 7.
This will be explained using the drawings up to the figure.

First, the fixed and movable molds 24 and 25 for lens molding and the molds 26 and 27 for frame molding are opened as shown in FIG. 2, and they are heated in advance to a glass molding temperature and a plastic molding temperature.

Next, the softened glass lump is placed on the fixed mold for lens molding 24, and the movable mold for lens molding 25 is brought close to the fixed mold for lens molding 24,
As shown in FIG. 4, a protruding edge 3 protruding in the radial direction (left-right direction in the figure) on the outer periphery of the effective diameter portion 30a.
A glass lens 30 having a diameter of 0b is formed.

Thereafter, the glass lens 30 is held between the fixed and movable molds 24 and 25 for lens molding, and the fixed and movable molds for lens molding are held while reducing the pressure of the movable mold for lens molding 25 applied to the glass lens 30. 24, 25 and the glass lens 30 are slowly cooled to the plastic molding temperature (20
(approximately 100℃) in about 1 minute. And frame molding mold 2
6 and 27 are closed as shown in FIGS. 5 and 6, plastic is injected into the cavities 26c and 27c, and the lens frame 31 is attached to the glass lens 3.
It is integrally molded with the ridge 30b of 0.

Finally, fixed and movable molds 24 and 25 for lens molding,
The glass lens 30, the frame molding molds 26, 27, and the lens frame 31 are lowered slightly (approximately 20°C) from the plastic molding temperature, and as shown in FIG.
Fixed and movable mold 24 for lens molding while supporting 1
25 and the frame molding molds 26 and 27 are opened and the framed lens is taken out to complete the desired framed lens.

FIG. 8 is a longitudinal sectional view showing an embodiment of the third invention. In the molding apparatus of this embodiment, a circular cavity 32b is concentrically arranged on a land 32a of a cylindrical frame molding fixed mold 32. A circular recess 3 is provided at the center of the bottom of the cavity 32b.
2c is provided. And cavity 32b
As shown in FIG. 9, a cylindrical lens molding fixed mold 33 is inserted into the recess 32c through one end of the lens molding mold 33. It is provided as a land 33a that collides with the movable mold for molding.

The fixed mold 33 for lens molding has its land 33a.
A semicircular spherical cavity 33b forming the outer shape of a glass lens to be described later is provided, and a land 33a surrounding this cavity 33b is formed with a small width, and a linear tapered surface 33c is connected to the outer periphery of the land 33a. There is.

Above the fixed mold 33 for lens molding in FIG. They are arranged facing each other on the same axis so that they can approach and separate from each other. Like the fixed mold 33, the movable mold 34 for lens molding has a hemispherical cavity 34b in its land 34a, and a land 34a surrounding this cavity 34b is formed with a small width, and a straight line is formed on the outer periphery of the land 34a. The tapered surfaces 34c are connected to each other.

The lens molding movable mold 34 includes a cylindrical frame molding movable mold 36 in which a land 36b is provided with a circular cavity 36a corresponding to the cavity 32b of the frame molding fixed mold 32.
A hole 3 perpendicular to the land 36b penetrated through the center of the bottom of the
6c and is slidably fitted.

The frame-forming movable mold 36 has flanges provided at both ends that are locked to the movable base 35 to restrict its movement range, and there is an elastic gap between the movable base 35 and one flange. It is elastically biased in the direction of the frame-forming fixed mold 32 via an elastic force 37 such as a compression coil spring.

Note that the cavities 32b and 36a of the fixed and movable molds 32 and 36 for frame forming are connected to the lands 32a and 36.
Runners 32d and 36d provided in b and gate 32
e and 36e. Furthermore, four ejector pins 38 inserted and extended in the same direction as the moving direction of the movable lens mold 34 and the movable frame mold 36 are inserted into and retracted from the cavity 32b of the fixed mold 32 for frame molding. It has been established.

Further, since this embodiment has substantially the same effect as that of the embodiment of the second invention, the explanation thereof will be omitted.

Furthermore, in the embodiments of the second and third inventions,
Although the case where the glass lens is biconvex has been described, the glass lens is not limited to this shape, and may be, for example, a biconcave lens or other lens shape.

Moreover, what is integrally molded with the protrusion of the glass lens is not limited to the lens frame, but may also be a lens barrel or other items.

Furthermore, the tapered surface of the lens molding die is not limited to a straight line, but may be a convex or concave curved surface.

Effects of the Invention As described above, according to the first invention, compared to the prior art, there is no need to take out the pressure-molded glass lens from the glass lens mold, so the number of man-hours can be significantly reduced. In addition, since the core of the glass lens and plastic frame is determined by the concentricity of the glass mold and the frame mold, it is possible to greatly improve the concentricity of both, and the so-called Z value. Even a glass lens with a low value can be made into a lens with a frame. Furthermore, since there is no bell clamp, there is no risk of damage to the lens surface.

Further, according to the second invention, in addition to the effects of the first invention, since the lens molding mold and the frame molding mold are separate, it is possible to increase the thermal energy efficiency required for heating the lens molding mold. , temperature control can be made relatively easy.

Furthermore, according to the third invention, in addition to the effects of the first invention, the movable molds for lens molding and frame molding are coaxial, and only one moving device is required for both.
This has effects such as simplifying the mechanism.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of the prior art, FIG. 2 is a vertical cross-sectional view showing an embodiment of the second invention, FIG. 3 is a cross-sectional view taken along the - line in FIG. 6 and 7 are respectively explanatory diagrams of the operation of FIG. 2, FIG. 8 is a longitudinal cross-sectional view showing an embodiment of the third invention, and FIG. 9 is a diagram showing the fixed mold for frame molding and lens molding. FIG. 24... Fixed mold for lens molding, 24a... Land, 24b... Cavity, 24c... Tapered surface, 25... Movable mold for lens molding, 25a... Land, 25b... Cavity, 25c... Tapered surface, 26, 27... Frame molding mold, 26a, 27
a...Land, 26b, 27b...Recess, 26
c, 27c... Cavity, 30... Glass lens, 30a... Effective diameter section, 30b... Projection, 3
1...Mirror frame, 32...Fixed mold for frame molding, 32a...
...Land, 32b...Cavity, 33...Fixed mold for lens molding, 33a...Land, 33b...
...Cavity, 33c...Tapered surface, 34...
Movable mold for lens molding, 34a...Land, 34b
...Cavity, 34c...Tapered surface, 36...
...Movable mold for frame forming, 36a...Cavity, 3
6b...land, 36c...hole, 37...bullet.

Claims (1)

[Scope of Claims] 1 A glass lens having a protrusion on the outer periphery of the effective diameter portion is formed by pressure-molding a softened glass lump using a lens mold, and this glass lens is held between the glass molds. In this state, the lens molding mold and the glass lens are cooled to a predetermined temperature, and then the plastic is injection molded using a frame molding mold that, together with the lens molding mold, forms a cavity around the ridge. A method for molding a lens with a frame, characterized in that a plastic frame is integrally molded with a rim. 2. The method for molding a framed lens according to claim 1, wherein the cooling to the predetermined temperature is gradual cooling from a glass molding temperature to a plastic molding temperature. 3. A fixed mold for lens molding and a movable mold, each having a narrow land surrounding the cavity and a continuous tapered surface on the outer periphery of the land, are arranged facing each other on the same axis, and a fixed mold and a movable mold for lens molding are arranged facing each other on the same axis. , a movable mold for lens molding is moved between a pair of frame molding molds, each of which has a concave portion in the land that engages with a half of the outer periphery of each mold, and which forms a cavity by surrounding each mold in the concave portion. A molding device for a lens with a frame, characterized in that the lenses are arranged facing each other so as to be able to approach and separate at right angles to the direction. 4. The framed lens molding apparatus according to claim 3, wherein the tapered surface is linear. 5. The framed lens molding apparatus according to claim 3, wherein the tapered surface has a curved shape. 6. The molding apparatus for a lens with a frame according to claim 3, wherein the pair of movable molds for frame molding each has an ejector pin movable in the same direction as the moving direction of the movable molds. 7. A fixed mold for lens molding is erected in the center of the bottom of the cavity provided in the land of the fixed mold for frame molding, in which a land surrounding the cavity is formed with a small width and a tapered surface is continuous on the outer periphery of the land. A movable mold for lens molding is disposed on the same axis, and the movable mold for lens molding has a narrow land formed to surround the cavity facing the fixed mold for molding, and a tapered surface is connected to the outer circumference of the land, and the movable mold for lens molding is arranged on the same axis. A movable mold for frame molding, which has a cavity corresponding to a fixed cavity for frame molding on a land, is slidably fitted through a hole perpendicular to the land penetrating the center of the bottom of the cavity, and A molding device for a lens with a frame, characterized in that the molding device is resiliently biased toward a fixed mold for molding. 8. The framed lens molding apparatus according to claim 7, wherein each of the tapered surfaces is linear. 9. The framed lens molding apparatus according to claim 7, wherein each of the tapered surfaces has a curved shape. 10. Claim 7, wherein the fixed mold for frame molding has an ejector pin that is movable in the same direction as the moving direction of the movable mold for lens molding.
A molding device for a lens with a frame as described in Section 1.