JP4347629B2 - Glass element molding equipment - Google Patents

Description

  The present invention relates to a molding device for glass elements such as optical lenses. More specifically, the present invention relates to a glass element molding apparatus capable of molding a glass element in a short time by heating and pressurizing a glass material loaded in a molding die by a heat conduction method in one stage and cooling it.

  When manufacturing glass elements such as optical lenses, prisms, and mirrors, a glass material is filled into a pair of upper and lower molding dies (hereinafter referred to as dies), heated and pressurized, and then cooled. It is common to form by. The method of heating the mold filled with the glass material at that time is a heater in which a heating block (heater) embedded in a metal block is brought into contact with the mold and heated by heat conduction from the heater block. There are known a block heating method (see Patent Document 1 and the like), a method in which an infrared lamp is used as a heat source, heating by radiant heat from the lamp (see Patent Document 2 and the like), and a method of heating by a high frequency induction heating method. Among these heating methods, the heater block heating method transfers the heat from the heater to the mold by heat conduction by directly contacting the mold and the heater block, so the mold surface is more uniform than by the infrared lamp method In general, it is generally used because it is less complicated to consider the location of the lamp depending on the shape of the mold as in the infrared lamp method, and to replace the lamp with a special one. This is a typical heating method.

  By the way, the vicinity of the molding part of the mold of the conventional glass element molding apparatus adopting this heater block heating method has a structure as exemplified in FIG. That is, in the molding chamber 102 surrounded by the outer wall 107 inside the apparatus, the piston in the press cylinder 105 was driven to move the press drive shaft 106 upward and placed on the heater block 104b. The mold 101 is pressed against the heater block 104a, and a pair of heater blocks 104a and 104b (104b also serves as a stage on which the mold 101 is placed) in a high temperature state in which the heaters 103a and 103b are embedded, respectively. After heating and pressurizing the mold 101 in a state where it is sandwiched from both the upper and lower directions, the energization to the heaters 103a and 103b is stopped and left as it is, or waiting for cooling while ventilating a gas such as an inert gas. After that, the mold 101 was taken out from the molding chamber 102.

  Thus, in the conventional glass element molding apparatus adopting the heater block heating method, the heater block is first heated to a temperature at which press molding can be performed by the built-in heater, and then the mold that is in direct contact with the heater block is used. After heating and pressurizing, it was cooled by leaving it as it was, so the heating and cooling speed of the heater block with a relatively large heat capacity could not be increased, and a considerable time was required for heating and cooling the mold. However, the productivity of the glass element has been reduced. In order to solve such a problem, as seen in Patent Document 1, a plurality of stages are provided to divide the process into a heating block, a molding block, and a cooling block, and the heating block maintains the heater block at a constant temperature. In addition, proposals have been made to shorten the time required for heating and cooling the mold by sequentially transporting the mold loaded with the glass material to each block, thereby increasing the production efficiency.

  However, when a plurality of stages are provided in this way, the number of operating parts increases, and the volume of the molding chamber increases. For example, when molding is performed with the molding chamber in a reduced pressure state, it takes time to reduce the pressure. Have On the other hand, in a heating type glass element molding apparatus using an infrared lamp as a heat source, a proposal has been made in which a molding chamber is a single stage (see Patent Document 3, etc.), but conventionally a heater block in which the volume of the molding chamber is relatively large. An example employed in a glass element molding apparatus employing a heating method is not known.

JP-A-4-164826 JP-A-5-186230 JP 2003-137562 A

  The present invention has been made in view of the problems of the glass element forming apparatus by the heater block heating method using the above-described heat conduction, and the heating and cooling process is more than the case where the conventional apparatus is used. It is an object of the present invention to provide a glass element forming apparatus that employs a heater block heating method that can be shortened and that can produce glass elements more efficiently.

  The present inventors have intensively studied the heating mechanism in the glass element molding apparatus adopting the heater block heating method that transfers the heat from the heater to the mold by heat conduction, and is filled with the glass material used for heating and pressurization. The portion that directly presses the molded mold and the heater are separated, and these can be moved independently of each other, and the mold and the mold are pressed directly according to each manufacturing process at the time of manufacturing the glass element. The above object can be achieved by a mechanism that can arbitrarily change the distance between the portion and the heater.

That is, the glass element molding apparatus of the present invention has the following configuration.
(1) A glass element molding apparatus for molding a glass element by heating and pressurizing a glass material loaded in a pair of molding dies composed of an upper mold and a lower mold, and then cooling the glass material, A molding chamber for housing a molding die, a pair of heaters arranged to be movable, and the molding die arranged so as to be movable while being separated from the heaters, directly from above and below. At least a pair of heating press plates that are sandwiched and pressed, and driving means that drives the heater and the heating press plate, and at the time of heating and pressurizing, the heater and the heating press plate, The heater and the heating press plate are moved to positions where the heating press plate and the molding die are in contact with each other, and at the time of cooling, the heater is moved in a direction away from the heating press plate. Glass element molding device being characterized in that as capable of moving.
(2) A bottom surface wall of the molding chamber that dissipates heat from the heating press plate when the heating press plate on which the molding die is placed moves downward and contacts during the cooling. The glass element forming apparatus according to (1), wherein the glass element forming apparatus is provided in a part of the glass element.

  According to the present invention, a heating press that presses a mold by separating a heating press plate that directly contacts and touches the mold and heats and pressurizes the mold and a heater that is a heat source so that each can be moved independently. The heater can be embedded in the press plate that is in direct contact with the mold because the volume of the plate can be reduced and the heater that is waiting in a high temperature state can be brought into contact with the heating press plate in advance to keep it warm. Unlike the conventional device of the same type that presses the mold while energizing the integrated heater block and raising the temperature, the time required for heating the mold in the heating and pressurizing process is shortened. In the cooling process, the heating press plate and the heater that are in direct contact with the mold are separated, and the heater that is in contact with the heating press plate at the time of cooling is immediately moved away from the heating press plate. As a result, the time required to cool the mold is greatly reduced compared with the conventional system, combined with the smaller volume of the part that directly contacts the mold (heating press plate). This increases production efficiency. Furthermore, since the heating / pressurizing process and the cooling process of the mold are performed in one stage, a glass element molding apparatus that saves space as compared with the conventional apparatus of the same type can be provided.

Next, the present invention will be described in more detail with reference to the drawings.
1 to 3 are schematic cross-sectional views illustrating the main part of the apparatus for explaining the operation cycle of the glass element forming apparatus of the present invention. The glass element molding apparatus of this example was fixed to the tip of a heating press plate support cylinder 5a penetrating substantially the center of the upper wall surface in the molding chamber 2 surrounded by the outer wall 10 formed of metal such as stainless steel. The heating press plate 4a made of cemented carbide or the like having good thermal conductivity is suspended and passes through the substantially central portion of the bottom wall surface in the molding chamber 2 so as to face the heating press plate support cylinder 5a. The heating press plate 4b is fixedly disposed on the front end surface of the heat press plate supporting cylinder 5b attached so as to be movable, and the heating press plate support cylinder 5a having the heating press plate 4a fixed on the front end surface is provided in the molding chamber 2. It is arranged in a fixed state on the inner upper wall surface. A heater 3a made of a coiled nichrome wire or the like connected to the heater drive shaft 6a, concentrically with the heating press plate support cylinder 5a, has the same central axis inside the heat press plate support cylinder 5a. Inside the heating press plate support cylinder 5b, the central axis is the same, and the heater 3b connected to the heater drive shaft 6b is arranged in a movable state concentrically with the heating press plate support cylinder 5b. . The heating press plate support cylinders 5a and 5b do not necessarily have to be cylindrical, and if the inside is a hollow cylindrical body that does not hinder the movement of the heaters 3a and 3b that are movably provided on the inside, There is no limitation on the shape of the cylindrical body having a square cross section, for example.

The heating press plate 4a and the heater 3a, and the heating press plate 4b and the heater 3b are separated from each other, and the piston of the heating press plate driving cylinder 9 and the heater driving cylinders 7a and 7b, which are driving means, are hydraulically or compressed air. And a mechanism capable of moving the heating press plate 4b and the heaters 3a and 3b independently of each other by the heating press plate drive shaft 8 and the heater drive shafts 6a and 6b.
Although not shown, the molding chamber 2 is provided with an entrance / exit for the mold 1 and an internal confirmation window, and the entrance / exit of the mold 1, the internal confirmation window and the heating press plate support cylinders 5a, 5b, If the space between the outer wall of the molding chamber 2 is packed with an O-ring, the atmosphere in the molding chamber 2 is not destroyed and the airtightness can be improved. Is connected to a rotary pump or a turbo molecular pump to evacuate the inside of the molding chamber 2 to be in a vacuum or reduced pressure state, or after replacing with an inert gas, the mold 1 is heated to heat the mold. And oxidation of glass components can be prevented.

  In order to manufacture a glass element by the glass element molding apparatus of the present invention, first, as shown in FIG. 1, a hot press plate 4b that serves as a stage for placing the mold 1 filled with a glass material is used. The heaters 3a and 3b are heated to a molding temperature in advance by energization (preparation step).

  Next, the heater driving cylinders 7a and 7b are operated, and the heater driving shafts 6a and 6b are moved until the heated heaters 3a and 3b come into contact with the heating press plates 4a and 4b, respectively. As shown in FIG. 2, the heating press plate driving cylinder 9 is operated to drive the heating press plate drive shaft 8 and the mold 1 placed on the heating press plate 4b is heated as shown in FIG. By moving the hot press plate 4b (that is, the hot press plate support cylinder 5b) until it abuts against 4a, the mold 1 is heated and pressed while being pressed by the hot press plates 4a and 4b, and this state is maintained for a predetermined time. To do. A thermocouple (not shown) is set on each of the heaters 3a and 3b and the heating press plates 4a and 4b, and the temperatures of the heaters 3a and 3b and the heating press plates 4a and 4b are detected independently. On the other hand, depending on the detected temperature of the hot press plates 4a and 4b, the amount of electricity supplied to the heaters 3a and 3b can be controlled so that the temperature becomes a desired temperature. (Heating / pressurizing process).

  When heating and pressurization are completed by pressing the mold 1 with the heated press plates 4a and 4b for a predetermined time, the energization to the heaters 3a and 3b is stopped, and as shown in FIG. 3, the heater driving cylinder 7a is stopped. 7b, the heater drive shafts 6a, 6b are driven to move the heaters 3a, 3b away from the heating press plates 4a, 4b, respectively, and the heating press plate drive shaft 8 is moved downward to move the mold 1 The mold 1 is naturally cooled by moving away from the heating press plate 4a. At this time, for example, a gas inflow hole (not shown) is provided between the upper and lower wall surfaces in the molding chamber 2 and the heated press plate support cylinders 5a and 5b, and the cooled inert gas or the like is vented from here. A cooling ring 11 made of a metal having good thermal conductivity is disposed at the bottom of the outer wall 10, and the heating press plate support cylinder 5 b is lowered to a position where the heating press plate 4 b comes into contact with the cooling ring 11. In this case, the heat of the heating press plate 4b is radiated to the cooling ring 11 by heat conduction, or instead of providing the cooling ring 11, a metallic pipe is provided and water is circulated therein. For example, it is more preferable to provide a heat dissipating part that can dissipate heat from the heating press plate 4b in order to increase the cooling rate of the mold 1 after heating and pressurization. (Cooling process).

When the mold 1 is cooled to a temperature at which it can be removed, the mold 1 inside the molding chamber 2 is taken out to obtain a molded glass element.
In the above embodiment, the heating press plate support cylinder 5a is fixed to the outer wall 10, and the heating press plate 4b (heating press plate support cylinder 5b) is moved upward by the driving means to heat the molding die 1. -Although the example which pressurizes was illustrated, on the contrary, the heating press board support cylinder 5b is fixed to the outer wall 10, and the heating press board 4a (heating press board support cylinder 5a) is lowered | hung with a drive means, and on the heating press board 4b You may comprise so that the metal mold | die 1 mounted in may be pressed and heated and pressurized.

It is a schematic sectional drawing explaining the state in the preparation stage of shaping | molding in the operation cycle of the glass element shaping | molding apparatus of this invention. It is a schematic sectional drawing explaining the state at the time of a heating and pressurization process in the operation cycle of the glass element shaping | molding apparatus of this invention. It is a schematic sectional drawing explaining the state at the time of a cooling process in the operation cycle of the glass element shaping | molding apparatus of this invention. It is a schematic sectional drawing which illustrates the principal part of the conventional glass element shaping | molding apparatus by a heater block heating system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Molding die 2, 102 ... Molding chamber 3a, 3b, 103a, 103b ... Heater 104a, 104b ... Heater block 4a, 4b ... Heating press plate 5a, 5b ... Heating press plate support Tube 6a, 6b ... Heater drive shaft 7a, 7b ... Heater drive cylinder 8 ... Heat press plate drive shaft 9 ... Heat press plate drive cylinder 10 ... Outer wall 11 ... Cooling ring

Claims (2)

  A glass element molding apparatus for molding a glass element by heating, pressurizing and then cooling a glass material loaded in a pair of molding molds composed of an upper mold and a lower mold. A molding chamber that accommodates the mold, a pair of heaters that are movably disposed, and the molding die that is movably disposed separately from the heaters is sandwiched directly from above and below. At least a pair of heating press plates to be pressed and driving means for driving the heater and the heating press plate are provided, and the heating means, the heating press plate, and the heating press at the time of heating and pressurization by the driving means. The heater and the heating press plate are moved to positions where the plate and the molding die are in contact with each other, and at the time of cooling, the heater is moved in a direction away from at least the heating press plate. Glass element molding device, characterized in that the obtaining manner. A part of the bottom wall of the molding chamber is provided with a heat dissipating part that dissipates heat from the heating press plate when the heating press plate on which the molding die is placed moves downward and comes into contact during the cooling. The glass element forming apparatus according to claim 1, wherein the glass element forming apparatus is provided.

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