JP3188496B2 - Mold for press molding glass lens and molding apparatus using the mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for press molding of a glass lens and a glass lens press molding apparatus using the mold, and more particularly to a reduction in the cooling rate of the mold. It is.

[0002]

2. Description of the Related Art In recent years, as a method of forming a glass lens, there has been a method of processing by polishing finishing which requires a complicated process, a method of plasticizing a preliminarily weighed glass block by an induction heating method using a high frequency or the like, and applying a precision press. Attention has been focused on a method of directly processing a glass lens into a final use shape.

Conventionally, this type of glass lens press molding apparatus is disclosed in Japanese Unexamined Patent Publication No.
There is one having a configuration as disclosed in Japanese Patent No. 170225.

[0004] In such a conventional apparatus of the prior art, a plurality of lenses are simultaneously pressed by the same mold, and a die plate and a heat insulating material arranged on the back side of the mold are used. The mold is cooled by forming an exhaust passage formed of a plurality of flow grooves communicating with the inside of the molding chamber in a radial manner.

[0005]

SUMMARY OF THE INVENTION The above-mentioned prior invention,
It is a very effective means to cool the mold uniformly,
In particular, it is an indispensable technique when molding a large-diameter precision lens.

For mass production of small-diameter precision lenses, which are in high demand, a plurality of cavities are arranged at the outer periphery of the mold, and one cavity is arranged at the center thereof. At present, a large number of individual products are taken.

However, in such multi-cavity glass lens press molding, a method is used in which a heating source is installed on the outer periphery and the temperature of the inner mold is raised. In addition, since it is difficult to control the temperature in the central portion, and very sophisticated and delicate temperature control is required, as shown in FIG. 5, for example, it takes more than four minutes to lower the mold temperature from 600 ° C. to 200 ° C. It takes time.

That is, due to the temperature difference between the outer peripheral portion and the central cavity of the mold, a longer waiting time is required to stabilize the elevated temperature, or the allowable range of the attained temperature is greatly reduced. If the cooling time of the mold in the molding cycle is long, there is a problem that not only the mass productivity is reduced but also the consumption of the inert gas is increased.

The present invention has been made in view of the above circumstances, and aims to make the temperature distribution in the cavity uniform and to reduce the cooling time of the mold after press molding. Accordingly, it is an object of the present invention to provide a glass lens press molding die and a molding device using the die, which can improve mass productivity.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a mold used for glass lens press molding, in which a plurality of cavities are formed on a mold mating surface. And a through hole is formed in the center
And at least one of the mold mating surfaces
A plurality of communication grooves leading to the molding chamber around the mold are formed.
It is characterized in that the.

The present invention also provides a press molding apparatus for a glass lens, wherein a plurality of cavities are formed on a mold mating surface.
With a through hole in the center ,
At least on the other hand, through this through hole, into the molding chamber around the mold
A die having a plurality of communicating grooves formed therein, a die plate provided on the back of the die and having a communication hole communicating with a through hole at the center of the die, and a die plate near the outer periphery of the rear surface of the die plate. A hollow heat insulator in contact with the heat insulator, comprising a support provided on the back surface of the heat insulator and having an inlet for supplying an inert gas to the internal space of the heat insulator, wherein the internal space of the heat insulator is provided via a partition member. The first die plate side space and the second
And the inert gas is separately introduced into these first and second spaces to form the mold,
It is characterized by being configured to be able to exhaust to the outside of the die plate and the heat insulating material.

[0012]

That is, the present invention uses a mold having a plurality of cavities on the outer periphery and a through hole in the center thereof, a die plate provided on the back of the mold, and a mold provided on the die plate. While providing a communication hole communicating with the through hole at the center, a hollow heat insulator is brought into contact with the vicinity of the outer periphery of the rear surface of the die plate, and the internal space of the heat insulator is made the first space.
Into a die plate side space and a second anti-die plate side space, and an inert gas is separately supplied to these first and second spaces so as to be directed to the outside of the mold, die plate and heat insulator. If the inert gas is introduced only into the space on the second side opposite to the die plate at the time of raising the temperature and during the press molding, the heat escaping from the die plate by heat conduction will be discharged by the heat insulator. As a result, more heat is taken away in the vicinity of the outer periphery of the die plate than in the center portion, so that the temperature is lowered. This makes it possible to make the temperature distribution in the radial direction of the die plate uniform.

In addition, when the temperature is lowered, if an inert gas is introduced into both the first and second spaces, the die plate can be rapidly cooled, so that the cooling time after press molding can be reduced. become.

Further, a through hole is provided at the center of the mold, and a communication hole communicating with the through hole is provided in the die plate, so that the mass of the mold is reduced and the inside of the through hole of the mold is reduced. In addition, an inert gas is also introduced, and cooling from the inside of the mold becomes possible, whereby the cooling time of the mold can be further shortened.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings shown in FIGS. 1 to 4. FIG. 1 schematically shows the entire configuration of a glass lens pressing apparatus according to the present invention. In the figure, 1 is a movable plate that can move up and down,
2 is a fixed plate.

A heat-resistant glass tube 3 is installed between the plates 1 and 2 so as to be sealable, and a heat-resistant glass tube 3 forms a molding chamber 4. An induction heating coil 5 is wound around the outer periphery of the glass tube 3.

In the molding chamber 4, the movable plate 1 is vertically movably engaged and has a fixed upper support 7 having an inert gas inlet 6, and the fixed plate 2 is vertically movable movably. Lower supports 9 which are held and have an inert gas inlet 8 face each other in the vertical direction.

The upper and lower heat insulators 10 and 11 are attached to the support members 7 and 9 respectively.
Are mounted with die plates 12 and 13, and the hollow heat insulators 10 and 11 are in contact with the outer periphery of the rear surfaces of the die plates 12 and 13, respectively.

The heat insulators 10 and 11 are connected to first die plate side spaces 10 a and 11 a communicating with inert gas inlets 6 and 8 provided in the upper and lower supports 7 and 9, respectively, and a second counter die plate. The internal space composed of the side spaces 10b and 11b is
The partitioning members 20 and 21 are formed integrally with or separate from the heat insulator.

Also, the first die plate side space 10a,
11a, the inert gas inlet 6 of the supports 7, 9;
The inert gas introduction pipes 23 and 24 passed through from 8 face,
These first and second spaces 10a, 11a, 10b, 1
Inert gas can be separately introduced into 1b.

The upper and lower die plates 12, 1
The upper and lower molds 14 and 15 are supported on the upper and lower molds 3, respectively. The upper and lower molds 14 and 15 have a plurality of sets of cavity dies 16 having a cavity surface corresponding to the upper and lower lens surfaces of the glass lens 30 to be molded. , 17 are fitted and held.

The periphery of the cavity dies 16 and 17 is surrounded by the upper and lower molds 14 and 15, while the back side is surrounded by the upper and lower die plates 12 and 13.

Further, in the drawing, reference numeral 18 denotes an inert gas inlet provided in the movable plate 1 so as to communicate with the inside of the forming chamber 4. From this inlet 18, a solid arrow shown in FIG. As shown by, the cooling operation is performed by supplying an inert gas into the molding chamber 4, and the inert gas introduced into the molding chamber 4 is opened to the fixed plate 2. The air is exhausted from the exhaust port 19 that has been exhausted.

The inert gas inlets 6 and 8 provided in the upper and lower supports 7 and 9 respectively have second anti-die plate side spaces 10b and 11b at the time of temperature rise and during press molding.
In addition, an inert gas is positively introduced, so that the vicinity of the outer periphery of the die plates 12 and 13 can be actively cooled through the heat insulators 10 and 11.

This second space 10b opposite to the die plate side,
The inert gas introduced into the heat insulator 11 b
The air is exhausted into the molding chamber 4 through exhaust ports 25 and 26 opened to the side of the mold 1.

On the other hand, the inert gas introduction pipes 23, 2 inserted through the inert gas introduction ports 6, 8 of the upper and lower supports 7, 9 respectively.
The inert gas introduced into the first die plate-side spaces 10a and 11a through the air purifier 4 is mainly intended for purging the air before the temperature rise, and also at the time of the temperature decrease and after the pressure molding. With the introduction of the inert gas into the anti-die plate side spaces 10b, 11b, the first die plate side spaces 10a, 10b,
The die plates 12, 13 and the dies 14, 15 can be cooled in a short time by introducing an inert gas into 1a.

Thus, the first of the heat insulators 10, 11
The inert gas introduced into the spaces 10a and 11a of FIG.
As shown in the figure, the heat insulators 10, 11 and the die plate 12,
An exhaust passage composed of a plurality of communication grooves 27 and 28 which are formed radially in the molding chamber 4 on at least one of the contact surfaces 13 (in the illustrated embodiment, on the side of the heat insulators 10 and 11). It is designed to be exhausted.

Further, through holes 14a, 15a are provided in the center of the upper and lower molds 14, 15, and the upper and lower die plates 12, 1 are provided in the through holes 14a, 15a.
The communication holes 12a and 13a provided in the central portion of No. 3 are formed so as to communicate with each other.

Further, as shown in FIG. 3, a plurality of communication grooves 29 extending radially from the through hole 15a are formed in one or both of the upper and lower molds 14, 15, and these communication grooves 29 are formed. The groove 29 forms an exhaust passage communicating with the inside of the molding chamber 4, and allows the inert gas introduced into the first spaces 10 a, 11 a of the heat insulators 10, 11 to flow into the central portions of the die plates 12, 13. Communication holes 12a provided,
Air is exhausted into the molding chamber 4 through the through holes 14a and 15a of the mold 13 and the molds 14 and 15.

Since the inert gas flows from the inert gas inlet 18 into the molding chamber 4 during the glass lens molding cycle, the heat insulators 10 and 11 are cooled by the inert gas. And these are die plate 1
It acts as a heat dissipating member for the vicinity of the outer circumferences of the die plates 2 and 13, thereby making it possible to make the temperature distribution in the radial direction of the die plates 12 and 13 uniform.

The inert gas introduced into the first spaces 10 a, 11 a of the heat insulators 10, 11 communicates with the communication holes 12 a, 13 provided in the center of the die plates 12, 13.
a and the through-holes 14a, 15a of the dies 14, 15 and the communication groove 29 are exhausted to the inside of the molding chamber 4, so that the center of the dies 14, 15 after press molding is not good. It is efficiently cooled by the active gas, thereby reducing the time required to lower the mold temperature from 600 ° C. to 200 ° C., for example, as shown in FIG. 4 by about 45 seconds as compared with the conventional one shown in FIG. I do.

[0032]

As is apparent from the above description, the present invention uses a mold having a plurality of cavities on the outer periphery and a through hole in the center thereof, and a die plate on the back of the mold. The die plate is provided with a communication hole communicating with the through-hole at the center of the mold, and a hollow heat insulator is brought into contact with the outer periphery of the rear surface of the die plate, and the internal space of the heat insulator is made the first space. Die plate side space and the second
Of the first die and the second die
Inert gas is separately supplied from the outside of the molding chamber to the space of the molding chamber, and the inert gas is exhausted to the inside of the molding chamber, that is, to the outside of the mold, the die plate, and the heat insulator. If an inert gas is introduced only into the space on the second side opposite to the die plate during press molding, the heat escaping from the die plate by heat conduction can be removed by the heat insulator, and the heat near the outer periphery of the die plate is reduced. The temperature is lowered by being more deprived than at the center side, whereby the temperature distribution in the radial direction of the die plate can be made uniform.

In addition, when the temperature is lowered, if an inert gas is introduced into both the first and second spaces, the die plate can be rapidly cooled, so that the cooling time after press molding can be shortened. .

Further, a through hole is provided at the center of the mold, and a communication hole communicating with the through hole is provided in the die plate, so that the mass of the mold can be reduced and the mold can be reduced. Inert gas is also introduced into the through hole,
Cooling from the inside of the mold can be performed, whereby the cooling time of the mold can be further shortened, and mass productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a glass lens press forming apparatus according to the present invention.

FIG. 2 is a transverse sectional view taken along the line AA of FIG.

FIG. 3 is a transverse sectional view taken along the line BB of FIG. 1;

FIG. 4 is an explanatory diagram showing a temperature drop characteristic of a mold temperature according to the present invention.

FIG. 5 is an explanatory view showing a temperature drop characteristic of a conventional mold temperature.

[Explanation of symbols]

4: molding chamber, 5: induction heating coil, 7, 9: support,
6,8 ... inert gas inlet, 10,11 ... heat insulator, 10
a, 11a: space on the first die plate side, 10b, 11
b: space on the second side opposite to the die plate, 12, 13: die plate, 12a, 13a: communication hole, 14, 15: mold,
14a, 15a: through hole, 16, 17: cavity die, 20, 21: partition member, 23, 24: inert gas introduction pipe, 25, 26: exhaust port, 27, 28: exhaust passage (communication groove), 29 ... Exhaust passage (communication groove), 30 ... Glass lens.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C03B 11/08 C03B 11/12

Claims (2)

(57) [Claims] A plurality of cavities are formed on a mold mating surface.
And a through hole is formed in the center , so that at least
On the other hand, the through hole leads to the molding chamber around the mold.
A plurality of communication grooves formed in the glass lens press molding die. 2. A press molding apparatus for a glass lens, wherein a plurality of cavities are formed in a mold-matching surface , a through hole is formed in a central portion, and at least one of the mold-matching surfaces is formed with a plurality of cavities.
Multiple communication from the through hole of the mold to the molding chamber around the mold
A die provided with a groove , a die plate provided on the back of the die and having a communication hole communicating with a through hole at the center of the die, and a hollow heat insulating member in contact with an outer periphery of the back of the die plate. And a support provided on the back of the heat insulator and having an inlet for supplying an inert gas to the internal space of the heat insulator. The internal space of the heat insulator is provided with a first member via a partition member. A die plate side space and a second anti-die plate side space are defined and inert gas is separately introduced into these first and second spaces and directed toward the outside of the mold, die plate and heat insulating material. A glass lens press forming apparatus characterized by being configured to be able to exhaust.