JPH01172230A - Formation device for optical element - Google Patents

Abstract

PURPOSE:To improve the efficiency of formation work of the title product by providing a cooling chamber for a object to be formed and disposing the cooling unit for a metallic die body in the inner part of the chamber. CONSTITUTION:The cooling chamber 3 enclosed with a frame body 4 is provided on a base plate 1 and a forming chamber 5 supported with supporting pillars 2' is disposed in the upper part of the cooling chamber. A metallic die body 12 is set on a supporting plate 14 which is supported so as to be vertically moved by the cylinder shaft 13 of a cylinder 19. After the cooling chamber 3 and the forming chamber 5 are substituted with inert gas, the object (a) to be formed set in the die 12 is heated by a heater 19 and formed by the cylinder 19. After the object (a) is solidified, the metallic die 12 is descended to the cooling chamber 3, and the object (a) is swiftly cooled by the cooling water in a water passage 25. The forming time for the object (a) is shortened because the cooling unit is disposed in the lower part of the cooling chamber 3 to carry out quick cooling. Consequently, the efficiency of forming work for the product is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves heat-softening and pressure-molding a molded object, which is a material for an optical element, and then cooling it in a vacuum or an inert gas atmosphere. The present invention relates to an optical element molding machine for producing optical elements.

[Conventional technology]

For example, as described in Japanese Unexamined Patent Publication No. 61-44721, there is a structure in which a cooling chamber is provided next to the heating and pressurizing chamber, and the press-formed object is naturally cooled in the cooling chamber.

In addition, as a device for forced cooling of the molded object, JP-A-62-
There is one in which a mold body is provided with a cavity for the circulation of a cooling medium, as described in Japanese Patent No. 191128.

[Problem that the invention seeks to solve]

In the conventional method that uses natural cooling, the temperature of the mold body rises to 400°C to 700°C during molding of the workpiece, and it is clear that it takes a considerable amount of time to naturally cool it. The disadvantage is that it is not possible to mold optical elements efficiently.

In addition, although it is noteworthy that the mold body has a cavity and a cooling medium is injected into the cavity for cooling, it is necessary to note that Not only does the mold itself have to be made larger, but the heat capacity increases during heating and pressurization in the pre-cooling stage, which inevitably lengthens the heating time. It is fully predicted that the boiling temperature of the medium or the heating temperature of the mold body will not be constant during pressurization).

The present invention was devised with the intention of eliminating the drawbacks of such conventional examples and shortening the molding time of optical elements. [Means for solving the problems] A molded object placed in a mold body. A cooling chamber for cooling the molded object in a vacuum or inert gas atmosphere is provided below the molding chamber in which the molding chamber heats and pressurizes the mold, and the mold is placed on a pedestal or a pedestal in the cooling chamber. A cooling device for the mold body is installed near the mold body, which simplifies the operation of moving the mold body between the molding chamber and the cooling chamber. This is to accelerate the cooling of the mold body.

〔Example〕

The drawings show an embodiment of the optical element molding machine according to the present invention, in which 1 shows a base placed on a support 2, and 3 shows a cooling chamber surrounded by a frame 4 placed on the base 1. , cooling chamber 3
There is provided a molding chamber 5 supported by columns 2' erected on the base 1, and the molding chamber 5 is surrounded by a heat insulating material 6 and separated from the cooling chamber 3. A pressure receiving block 7 is provided in the upper part of the molding chamber 5 to protrude downward, a holding cylinder 8 is provided directly below the pressure receiving block 7 along the axis, and a heater surrounded by a heat insulating material 9 is provided inside the holding cylinder 8. 10 are arranged vertically along the axis.

Reference numeral 11 denotes a communication hole between the molding chamber 5 and the cooling chamber 3, and the communication hole 11 is provided directly below the pressure receiving block 7 and in the bottom plate 6' constituting the molding chamber 5.

Reference numeral 12 denotes a mold body that enters and exits the cooling chamber 3 and the molding chamber 5 through this communication hole 11. The mold body 12 is removably placed on a support plate 14 placed on the cylinder shaft 13, and the body cylinder 15 and a pair of upper and lower molds 16 and 17 that sandwich the molded object a.

The cylinder shaft 13 is mounted on a support stand 18 provided on the base 11.
It is led out from the cooling chamber 3 through the cooling chamber 3 and connected to the cylinder 19.

In the figure, 20 and 20' are thermocouples for measuring the temperature of the upper mold 16 or lower mold 17, 21 is a heat insulating ring, 22 is a connecting pipe connected to a vacuum pump, 23 is a connecting pipe connected to an inert gas cylinder, Each connecting pipe 22, 23 is provided on the base 1 to communicate the cooling chamber 3 with the outside world.

Further, the illustrated reference numeral 24 is an opening/closing door of the cooling chamber 3.

Note that 30.30'' in the figure indicates an engagement gap for the thermocouple 20.20', and 31 indicates an assembly stand for the mold body 12.

Thus, the mold 12 with the molded object a assembled is placed on the supporting plate 14.
The air in each chamber 3.5 is replaced with inert gas using the connecting pipes 22, 23, and electricity is supplied to the heater 10 to heat the heater 10 and operate the cylinder 19. Then, the mold body 12 is inserted into the heater part lO in the molding chamber 5 through the communication hole 11 and heated to a predetermined temperature, and then the cylinder 19 is further actuated to push the mold body 12 up. The upper and lower molds 16 and 17 of the mold body 12 are compressed by the pressure receiving block 7 and the support plate 14, and the molded object a interposed between the upper and lower molds 16 and 17 is deformed into a predetermined shape by this pressing pressure. When the upper mold 16 and the lower mold 17 are deformed along the mold surfaces, the temperature of the heater IO is gradually lowered, and when the molded object a stops flowing and is fixed in a predetermined shape, the cylinder 19 Operate the mold 1
2 is placed on a support stand 18 provided in the cooling chamber 3 and cooled.

(First Example) A first example is shown in FIG. In the first embodiment, a cooling water channel 25 is provided inside the support stand 18, and both ends 25'' and 25' of the cooling water channel 25 are connected to a cooler.

That is, after heating and pressure forming, the mold body 12 placed on the support stand 18 is rapidly heated to a temperature at which the material of the molded object a is not oxidized by the cooling water flowing through the cooling water channel 25 of the support stand 18. After cooling is completed, it is taken out to the outside through the opening/closing door 24.

(Second Embodiment) FIG. 2 shows a second embodiment. In this embodiment, a heat pipe 26 is attached to the support stand 18, and a heat dissipation fin is attached to one end of the heat pipe 26 led out from the support stand.
It is constructed by attaching 7.

In this embodiment, the mold body 12 in a high temperature state is placed on the support base 1.
By being placed on and in contact with the mold body 8 , the heat of the mold body 12 is transferred to the support stand 18 , and the heat transferred to the support stand 1 is radiated by the heat radiation fins 27 via the heat pipe 26 .

According to this second embodiment, efficient heat radiation can be performed without using a medium such as cooling water.

(Third Embodiment) In the third embodiment shown in FIG. After heating and pressure molding, the mold body 12 placed on the support stand 18 is cooled by the cooling medium jetted from the nozzle 28.
Since the mold body 12 is directly cooled by the medium, highly efficient cooling work can be performed.

(Other Examples) Although the first example uses cooling water, cooling air may also be used.

〔Effect of the invention〕

Since the present invention provides a cooling chamber below the molding chamber, the mold body can be easily moved between the compartments by using a cylinder for pressurizing the molded object. That is, unlike the conventional example, a special conveyance device is not required.

In addition, since the cooling chamber is provided with a support for placing the mold body and a cooling device for the mold body is provided, the mold body, that is, the object to be molded, can be rapidly cooled. Molding work for molded products can be carried out efficiently.

[Brief explanation of the drawing]

The drawings show embodiments of the optical element molding machine according to the present invention, and FIG. 1 is a cross-sectional view of the first embodiment, FIG. 2 is a second embodiment, and FIG. 3 is a sectional view of a third embodiment. Further, FIGS. 4A to 4C are sectional views showing each embodiment of the mold body. 3... Cooling chamber 5... Molding chamber 12... Mold body 18... Support stand 25... Cooling channel 27... Radiation fins 28... Injection nozzle Fig. 2 Fig. 30

Claims (1)

[Claims] A cooling chamber for cooling the molded object in a vacuum or inert gas atmosphere is provided at the bottom of the molding chamber where the molded object placed in the mold body is heated and pressurized. An optical element molding machine provided with a cooling device for the mold body placed thereon.