JPH06206732A - Apparatus for forming glass lens - Google Patents

Abstract

PURPOSE:To carry out the automatic and accurate positioning of an upper mold and a lower mold of a forming mold independent of the accuracy of the molding machine itself. CONSTITUTION:A pair of guide pin G and tapered pin T oppositely positioned at the diagonal positions of a die set 50 for fitting and supporting a lower mold 30 are made to be insertable into a guide hole GH and a tapered hole TH positioned at the corresponding positions on a die set 40 for fitting and supporting an upper mold 20. Glass placed between the upper mold and the lower mold is heated in a state to loosely engage the guide hole GH with the guide pin G before lowering the upper mold 20 and, thereafter, the lowering of the upper mold 20 is restarted to effect the complete engagement of the tapered hole TH with the tapered pin T and form a formed lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for pressing a glass lens, and more particularly to an improvement of a molding apparatus for pressing an optical glass lens which requires high precision by a high frequency induction heating method. Is.

[0002]

2. Description of the Related Art In a conventional glass lens press molding apparatus, a mold fixing method is used in which a molding die is directly fixed to a molding machine, and the molding die itself is placed so as to be movable to regulate the positions of upper and lower molding surfaces. In addition, there is a carrier moving method in which a blank material and molded lenses are fed and discharged by using a carrier for a mold fixing type molding machine.

As a method of high-frequency induction heating, a molding die is made of a material suitable for induction heating and is placed directly on the molding die, or a member supporting the periphery of the molding die and the molding die is guided. The type of heating the forming die indirectly by heating has been adopted.

Further, as a method of heating the periphery of the molding die with an induction heating coil, as shown in FIG.
Is placed on the outer periphery of the molding die supports 4 and 5 to which the upper die 2 and the lower die 3 of a plurality of molding dies are attached, and the whole is heated, or as shown in FIG. A method has been adopted in which each mold is individually wound with a wire and induction heating is performed by each heating coil 6.

[0005]

However, the mold fixing method is
Since the molding machine itself aligns the upper and lower molds, a high-precision molding machine is required, and the position adjustments of the upper and lower molds are required each time the mold is replaced. When a medium trouble occurs, there is a drawback that the work must be interrupted for a long time.

Further, in the mold moving method, since the upper mold and the lower mold are aligned with each other by the molding mold itself, high machining precision of the molding mold is required, and the structure becomes complicated, so that the cost becomes high and there is a problem in durability. In addition, the carrier method requires some precise alignment between the carrier and the molding die, and there are some problems to be solved, such as the possibility of malfunction during feeding and discharging.

On the other hand, when the molding die is directly heated by the high frequency induction heating method, it is necessary to form the molding die by a material suitable for high frequency induction heating, and the mold material is restricted, and the molding die is indirectly heated. Has a problem in that heating efficiency is poor because the heating body needs high processing accuracy because the heating body supports the molding die and the heating body is in direct contact with the molding machine.

Also, the above-mentioned drawing as an example of arrangement of heating coils.
The layout shown in Fig. 11 has a large temperature difference between the central part and the outer peripheral part of the sleeve, which makes it difficult to obtain a homogeneous molded product due to a large temperature gradient in the cavity. Since the coil length for winding each of the forming dies 7 and 8 located at the winding start and the winding end of the heating coil 6 is longer than the length of the coil for winding the other forming dies (shown by a chain line), the heat quantity However, there is also a problem in that there is an imbalance and the quality of molded products varies.

As a result of solving these problems and improving the present invention, it is possible to easily mold a mold and efficiently and evenly heat it by a high frequency induction heating method to stably mold a high quality lens. It is an object of the present invention to provide a molding device for a glass lens that enables the above.

[0010]

The above object is to provide a glass lens molding apparatus for supporting an upper die and a lower die of a molding die on a press molding machine through upper and lower die sets, respectively. A glass lens, wherein a position regulating member that engages with each other is provided in the die set, and the positions of the upper die and the lower die of the molding die are adjusted by the engagement of the position regulating member during the molding process. And a glass lens molding apparatus using a high-frequency induction heating method, a sleeve-shaped heating member formed of a material having a high high-frequency induction heating property on either the upper mold or the lower mold of the molding die. A glass lens molding apparatus, which supports a member and directly or indirectly heats the upper mold and the lower mold of the molding mold through the heating member,
And a glass lens molding apparatus using a high-frequency induction heating method, a plurality of molding dies are arranged such that their centers occupy symmetrical positions on a concentric circle centered on the axis of the molding machine, and the plurality of molding dies are formed. This is achieved by a glass lens molding apparatus, characterized in that the working die is continuously wound by a single high-frequency induction heating coil that goes around the concentric circle.

[0011]

Embodiments of the present invention will be described with reference to FIGS.

FIG. 1 shows a glass lens molding apparatus according to claim 1 of the present invention. An upper mold 20 and a lower mold 30 of a molding die are inserted through die sets 40 and 50, respectively. The glass which is attached and fixed to the movable plate 60 and the fixed plate 70 and heated and moved by the high-frequency induction heating coil (hereinafter simply referred to as a heating coil) 10 moves and moves the movable plate 60 up and down. The lens is molded by pressing.

As shown in FIG. 2A, the die set 50 has a pair of guide pins G as first restricting members at symmetrical positions sandwiching the molding die, and a pair of second guide members G at positions orthogonal to the pair of guide pins G. A taper pin T is provided, while the die set 40 has a guide hole GH and a taper hole TH at positions corresponding to the guide pins G and the taper pins T.

When glass is supplied and the die set 40 is lowered by the operation of the movable plate 60, the guide hole GH is loosely fitted into the guide pin G to guide the upper die 20 to the lower die 30. In this state, the movable plate 60 is temporarily stopped and temporarily stopped at a position slightly before the abutting position.

In this state, the glass is softened by the heating coil 10 and the descent of the movable plate 60 is resumed, so that FIG.
As shown in FIG. 5, the above-mentioned taper pin T is fitted into the taper hole TH to guide the upper mold 20 to the lower mold 30 with extremely high accuracy.

Therefore, since the position of the upper die 20 of the forming die relative to the lower die 30 can be restricted between the upper and lower die sets 40 and 50, the forming machine itself does not require high precision and the forming die is designed. The degree of freedom is increased, and the cost can be reduced.

It is also possible to mount a plurality of the same molds on the die set 50 and mold a large number of lenses at the same time. In that case, the fitting holes 30 of the die set 50 for supporting the lower mold 30.
As shown in FIG. 3, it is preferable that A is placed in a symmetrical position on a concentric circle centered on the center of the die set 50 in a well-balanced manner, and in order to prevent deformation of the die set 50 due to heating, the radial direction as shown in FIG. It is desirable to provide a water channel C to circulate cooling water to make the temperature distribution uniform, and the same can be said for the die set 40 side on which the upper die 20 is mounted.

Further, the upper and lower die sets 40 and 50 can be diverted as die sets for attaching other types of forming dies by standardizing the fitting holes for attaching the upper die 20 and the lower die 30 to the standard. .

As the material for forming the die set, it is desirable to use a non-magnetic material such as SUS304 in order to improve the heating efficiency of the molding die, while the heating coil 10 is made of an insulating material such as glass epoxy resin. In addition, it shall be fixedly placed on a die set through a material having high heat resistance and moved during feeding and discharging of glass.

FIG. 5 shows an example of how to attach the forming die to the die set, using the lower die 30 as an example.
The height of 30 is adjusted by the heat insulating spacers 31 and 32, and the heat insulating sleeve 33 to be engaged is pressed by the holding plate 35 fixed to the die set 50a by the pressure contact force of the hollow ring 34, so that the die set 50b and the holding plate 35 are pressed. It is sandwiched between and supported by the die set 50.

Each of the heat insulating spacers 31 and 32 and the heat insulating sleeve 33 are made of a heat insulating material such as zirconia in order to improve the heating efficiency of the molding die. , While a copper material is used for the hollow ring 34 to facilitate crimping.

If the engaging portion of the heat insulating sleeve 35 is formed in a U-shape, the pressing plate 35 can be easily attached and detached, and the axis of the mold can be offset by aligning the direction with the upper mold 20 side. Even if it occurs, there is an advantage that it can be offset.

FIG. 6 shows the essential parts of the molding apparatus according to the fourth aspect of the present invention. The upper mold 20 and the lower mold 30 of the molding die are heat insulating spacers 21, 31 and 22 made of the above-mentioned heat insulating material, respectively. It is fixed to upper and lower die sets of a molding machine (not shown) by sandwiching 32 with heat insulating sleeves 23 and 33.

As shown in FIG. 6 (a), the upper die 20 has a groove 20A having a semicircular cross section on the outer peripheral surface, and a ring 80, which is an annular member having a circular cross section, is engaged with the groove 20A.

Before the ring 80 is engaged with the upper die 20, a heating sleeve 81 of a screw member is inserted in advance, and after the ring 80 is engaged, a heating sleeve 82 of a screw member is also screwed into the heating sleeve 81. By sandwiching the ring 80, the heating sleeves 81 and 82 are integrally supported.

Each of the heating sleeves 81 and 82 is made of a material having a high heating property by high frequency induction, and the positional relationship with the upper die 20 is such that a plurality of the grooves 20A are provided and the ring 80 is engaged. Adjusted by selecting position.

Since both of the heating sleeves 81 and 82 are in contact with the upper die 20, they are effectively induction-heated by a high frequency to efficiently heat the upper die 20 to a high temperature state.

The heating sleeve 82 is shown in FIG. 6 (b).
Form a spiral groove 82A on its circumferential surface as shown in
It can also be used to open the inlet pipe P and introduce an inert gas into the cavity to prevent oxidation of the mold and to perform rapid cooling after molding, and the gas is uniformly distributed along the groove inside the cavity. Therefore, the lens surface deformation due to uneven heat is prevented. Further, it is convenient to install the thermocouple TS for temperature control.

As for the temperature control of the molding die when the above heating sleeve is used, as shown in the graph of FIG. 7, the temperature of the molding die is maintained even after the heating sleeve 82 is heated to reach the pressable temperature T1. Temperature T for a certain period of time considering the temperature difference
After 1 is maintained, press working is performed within a time period from t ₂ to t ₃ , and when the detected temperature is sufficiently lowered, the molding die is opened to remove the lens. As a result, the temperature distribution of the mold becomes uniform.

Further, FIG. 8 shows a main part of a molding apparatus according to claim 8, wherein each upper mold 20 of the plurality of molding dies is at a symmetrical position of a peripheral portion of a die set 50A which is a support on the molding machine side. Are arranged so as to occupy each of the upper dies 20, and are wound with a gap provided by each heating coil 101 formed by the high-frequency induction heating coil wire 100 that circulates on the outside of each upper die 20.

By winding the heating coil wire 100 around the outside of each upper die 20, as shown in the drawing, each heating coil 101A for winding the respective upper die 20A and 20B located at the winding start and winding end is shown. Can be made to be exactly equal to the length of each heating coil 101 around which the other upper mold 20 is wound, and as a result, uniform heating of each upper mold 20 can be realized.

As shown in FIG. 9, the heating coil wire 100 has a bracket-shaped support member 102 formed by integrating bolts B with each other.
It is supported and fixed to the die set 50A by being inserted into the elongated hole 102A and sandwiched by the nut N.

Further, since the end portion of the heating coil wire 100 is integrated with the bus bar 110 fixed to the movable plate 60 of the molding machine by welding as shown in FIG. 10, when the bus bar 110 is attached and detached, the heating coil wire 100 is attached. There is no risk of contact failure at the connection between 100 and bus bar 110, or even water leakage when circulating cooling water in the heating coil wire 100, and a feeder F connected to a high frequency power supply is joined. Alternatively, the heating coil can be easily and safely attached to and detached from the molding machine main body simply by separating the heating coil.

It should be noted that each of the above heating coils 101 has a structure shown in FIG.
The short circuit 200 shown in (b) is installed in parallel, and the heating coil 101 is controlled by controlling the variable resistance R or performing ON-OFF control based on the detection result of the temperature sensor S provided in each mold. It is possible to adjust the current value supplied to the.

As a result, the temperature difference between the molding dies is minimized, and the molding of the lens with stable quality is realized.
When we actually conducted a control experiment, we found that at a high-frequency heating temperature of 600 ° C, multiple mold temperatures that initially caused a temperature difference of 50 ° C or more
The temperature difference could be controlled below 0.8 ℃.

As the form of the short circuit 200, a well-known power control system such as a thyristor system is used in addition to the transistor system shown. The short circuit of FIG. 8 (b) is a half-wave control. This is because when the double-wave control is performed, the power supply waveform is greatly distorted and the oscillation of the high frequency power supply is not stable. Can reduce the influence on the power supply waveform by reversing the direction of half-wave control by half.

[0037]

According to the present invention, the position of the molding die can be automatically regulated with high accuracy irrespective of the accuracy of the molding machine body, and the high-frequency induction heating can uniformly and efficiently heat the molding die. As a result, a high quality lens can be stably molded, and a highly versatile glass lens molding device is provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a glass lens molding apparatus of the present invention.

FIG. 2 is a configuration diagram showing a relationship between a molding die and a die set in the apparatus.

FIG. 3 is a perspective view of a die set.

FIG. 4 is a plan view of a die set.

FIG. 5 is a sectional view of a main part of a die set.

FIG. 6 is a configuration diagram showing a relationship between a molding die and a heating sleeve.

FIG. 7 is a graph showing a control temperature of a molding die.

FIG. 8 is a layout diagram and a circuit diagram of a coil for high frequency induction heating.

FIG. 9 is a partial view showing a method of supporting an intermediate portion of a heating coil.

FIG. 10 is a partial view showing a method of supporting an end portion of a heating coil.

FIG. 11 is an explanatory view showing a method for heating a molding die.

FIG. 12 is an explanatory diagram showing a conventional example of a layout of a heating coil.

[Explanation of symbols]

 10, 101, 101A Heating coil 20 Upper mold 30 Lower mold 31,32 Insulation spacer 33 Insulation sleeve 40, 50 Die set 60 Movable plate 80 Ring 81, 82 Heating sleeve 100 Heating coil wire G guide pin GH guide hole T Taper pin TH Taper hole P Inlet tube TS Thermocouple

Claims (12)

[Claims] 1. A glass lens molding apparatus for supporting an upper die and a lower die of a molding die on a press molding machine through upper and lower die sets, respectively, and positions at which the upper and lower die sets are engaged with each other. A glass lens molding apparatus, wherein a regulating member is provided, and the position of the upper die and the lower die of the molding die is adjusted by engagement of the position regulating member in the process of molding. 2. The position restricting member is composed of a cylindrical first restricting member and a tapered second restricting member, and the first and second restricting members are sequentially engaged in a molding process. The glass lens molding apparatus according to claim 1, wherein the position of the molding die is adjusted. 3. The glass lens molding apparatus according to claim 1, wherein both the die set and the position regulating member are made of a non-magnetic material. 4. A glass lens molding apparatus using a high-frequency induction heating method, wherein a sleeve formed of a material having a higher high-frequency induction heating property than either of the upper mold and the lower mold of the molding mold. The heating member in the form of a square, the heating member is not in contact with the support of the molding die,
A glass lens molding apparatus, which directly or indirectly heats the upper mold and the lower mold of the molding mold via the heating member. 5. The heating member is composed of two screw members screwed with each other, and by sandwiching an annular member engaged with the outer peripheral surface of the upper mold or the lower mold of the molding die, The apparatus for molding a glass lens according to claim 4, which is supported by a molding die. 6. The heating member has a spiral groove formed on the inner peripheral surface thereof, and a cooling gas is introduced into the cavity of the molding die through a tube made of a non-magnetic member opening to the groove. The glass lens molding apparatus according to claim 4 or 5, wherein the glass lens molding apparatus is configured as described above. 7. The glass lens molding apparatus according to claim 4, wherein the heating member includes a thermocouple to control the temperature of the molding die. 8. A glass lens molding apparatus using a high frequency induction heating method, wherein a plurality of molding dies are arranged such that their centers occupy symmetrical positions on a concentric circle centered on the axis of the molding machine, A glass lens molding apparatus, wherein a plurality of molding dies are continuously wound by a single high-frequency induction heating coil that circulates outside the concentric circle. 9. The high-frequency induction heating coil is integrally provided with a bolt, and is supported in an elongated hole portion of a heating coil support body by being sandwiched with a nut screwed with the bolt,
9. The glass lens molding device according to claim 8, wherein the glass lens molding device is fixed. 10. A short circuit that is provided in parallel with a part or all of the high-frequency heating coils that circulate around the plurality of forming dies, and detects the value of the current supplied to the high-frequency induction heating coils by detecting the temperature of each of the forming dies. The glass lens molding apparatus according to claim 8 or 9, which is controlled. 11. The glass lens molding apparatus according to claim 10, wherein the variable resistance circuit is a half-wave control circuit, and the direction of the control current is reversed for each mold. 12. The bus bar portion connecting the high-frequency induction heating coil and a feeder connected to a high-frequency power source has an integral structure with the heating coil, and the connection with the feeder can be separated. Item 8. A glass lens molding apparatus according to item 8.