JP2006232635A - Device for forming thermoplastic member and method for forming the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for forming thermoplastic members where, in mold forming for thermoplastic members such as optical stocks, forming can be simultaneously performed to many members, and also, uniform heating and the increase of a cooling speed can be realized. <P>SOLUTION: The device is composed of a first die 1 as a pressing member and a second die 2 provided with a plurality of molds 9, and in which the molds 9 are pressed, and thermoplastic members placed in the molds 9 are formed, and the molds 9 are arranged in the shape of a concentric circle at equal intervals in the second die 2. The second die 2 is provided with heat sources 6, 7 for uniformly heating the plurality of molds 9. The heat sources 6, 7 are provided at least on either the central part of the second die 2 or the outer circumference of the outside of the second die 2. The second die 2 is provided with cooling passages 20, 21 of uniformly cooling the molds 9. The cooling passages 20, 21 are provided in the shape of a concentric circle among the molds 9 or at the parts on the sides inner than the molds 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding apparatus for a thermoplastic member such as an optical material and a molding method thereof, and more specifically, a thermoplastic member such as an optical lens formed of glass or plastic of a digital camera, a projector or the like by molding. The present invention relates to a molding apparatus and a molding method for a thermoplastic member to be manufactured.

  2. Description of the Related Art Conventionally, when manufacturing a relatively small diameter aspherical lens or the like, a mold for putting an optical material in a mold and pressurizing and molding the mold is known. In the molding of such an optical element, there has been a molding method for molding an optical material softened by heating and then cooling it to obtain an optical element, and a molding apparatus for carrying it out. In this case, the optical material is molded by setting a plurality of sets of molds composed of the upper core mold and the lower core mold in the same molding apparatus.

JP-A-9-77520 (2nd page-4th page, FIG. 4)

  In the molding of the conventional optical element, the temperature difference between the outer peripheral portion and the central portion becomes significant at the mold arrangement position during heating, and the glass viscosity may vary between the molds. In some cases, it may be difficult to give a uniform pressing force during molding. In addition, even during cooling, the temperature difference between the outer periphery and the vicinity of the center becomes significant at the position where the mold is placed, and there may be variations in glass viscosity between the molds. It might be difficult to give. In addition, the mold has poor maintenance.

  The present invention has been made to solve the above-described problems. In molding a thermoplastic member such as an optical material, a large number can be simultaneously molded, and uniform heating and cooling can be speeded up. An object of the present invention is to provide a molding apparatus and a molding method for a thermoplastic member.

  The thermoplastic member molding apparatus according to the present invention includes a first mold that is a pressing member, and a thermoplastic that includes a plurality of molds and the mold is pressed by the first mold and placed in the mold. It consists of a second mold in which members are molded, and the molds are arranged concentrically and at equal intervals in the second mold. For this reason, a plurality of thermoplastic members can be simultaneously molded by a plurality of molds, heat can be uniformly applied to the thermoplastic members in the mold during heating, and further, in the mold during cooling. The thermoplastic member can be cooled uniformly. Moreover, the maintenance of the mold can be easily performed.

  In the thermoplastic member molding apparatus according to the present invention, a heat source for uniformly heating the plurality of molds is provided on the second mold. For this reason, heat can be uniformly applied to the thermoplastic member in the mold during heating.

  In the thermoplastic member molding apparatus according to the present invention, the heat source is provided in at least one of a central portion of the second mold and an outer periphery of the second mold. For this reason, heat can be uniformly applied to the thermoplastic member in the mold during heating, and uniform pressing force is applied to the mold without variation in the viscosity of the thermoplastic member between the molds. be able to.

  In the thermoplastic member molding apparatus according to the present invention, the heat source is provided concentrically near the center of the second die, and is an outer portion of the concentric circle where the die is disposed. Concentric circles are provided between the molds. For this reason, heat can be uniformly applied to the thermoplastic member in the mold during heating, and uniform pressing force is applied to the mold without variation in the viscosity of the thermoplastic member between the molds. be able to.

  In the thermoplastic member molding apparatus according to the present invention, a cooling channel for uniformly cooling the mold is provided in the second mold. For this reason, the thermoplastic member in a metal mold | die can be cooled uniformly at the time of cooling.

  In the thermoplastic member molding apparatus according to the present invention, the cooling flow path is provided concentrically between the molds and inside the molds. For this reason, the thermoplastic member in the mold can be uniformly cooled during cooling, and the thermoplastic member can be uniformly cooled without variation in the cooling rate of the thermoplastic member between the molds. Can do.

  The thermoplastic member molding apparatus according to the present invention includes a mold cooling channel for uniformly cooling the mold in the mold, and the mold cooling channel communicated with the cooling channel. It is. For this reason, the speed which cools the thermoplastic member in a metal mold | die can be made quick.

  The method for molding a thermoplastic member according to the present invention includes placing a thermoplastic member in a plurality of molds arranged on the same circumference of the second mold according to any one of the above, and uniformly molding the mold. After being heated, it is pressed and then cooled more uniformly. For this reason, heat can be uniformly applied to the thermoplastic member in the mold during heating, and the thermoplastic member in the mold can be uniformly cooled during cooling.

[Embodiment 1]
FIG. 1 is a schematic explanatory diagram of an optical element molding apparatus according to Embodiment 1 of the present invention, FIG. 2 is an exploded perspective view of a main part of the optical element molding apparatus, and FIG. 3 is a plan view of the main part of FIG. 4 is a cross-sectional view taken along the line AA in FIG. A molding apparatus for an optical lens, for example, an optical element, includes an upper mold 1 and a lower mold 2. The upper mold 1 is a pressing plate that is driven up and down by a hydraulic mechanism (not shown), and the lower mold 2 has a revolver shape. It is comprised by the mother die 3 and the lower plate 4 attached to the lower part. A heater insertion hole 5 is provided in the center of the mother die 3 and a heater 6 is inserted therein. An infrared lamp 7 is provided on the outer periphery of the mother die 3, and a heating method using an external / internal combination method is adopted. Has been.

  Around the heater insertion hole 5 located in the center, a plurality of mold insertion holes 8 are arranged uniformly at regular intervals concentrically with the heater insertion hole 5, and inside the mold insertion hole 8 is a cylinder. A metal mold 9 is inserted. As described above, the optical element molding apparatus includes a plurality of molds 9 concentrically so as to improve the manufacturing efficiency of the optical elements so that a plurality of optical elements can be molded simultaneously. Between the molds 9 arranged concentrically, a first cooling flow path 20 is provided along a concentric circle a of these molds 9, and a concentric circle is formed around the heater insertion hole 5 on the inner peripheral side thereof. The second cooling flow passages 21 are arranged so as to correspond to the first cooling holes 20, that is, the corresponding cooling holes are positioned on the same straight line passing through the heater insertion hole 5. Yes.

Each of the mold insertion holes 8 is constituted by a core upper mold 11 having a female recess 10 that forms the upper surface of the lens and a core lower mold 13 having a female recess 12 that forms the lower surface of the lens. A mold 9 is inserted and supported by the lower plate 4. Both the core upper mold 11 and the core lower mold 13 are made of a material having predetermined heat resistance and strength, for example, hard metal. The core upper mold 11 receives pressure in the direction of the arrow shown in FIG. 1 by the upper mold 1 which is a pressing plate that is driven up and down by a hydraulic mechanism.

  As shown in FIG. 5 (only the cooling flow path is shown), the first and second cooling flow paths 20 and 21 are formed in a cylindrical shape in the vertical direction of the mother die 3. The lower plate 4 is formed with coolant introduction holes 22 in the vertical direction along the outer periphery of the heater 5, and further, groove portions 23 corresponding to the coolant introduction holes 22 are formed along the surface of the mother die 3 side. The groove 23 communicates with the lower portions of the first and second cooling channels 20 and 21. As shown in FIGS. 6 and 7, the first cooling flow path 20 is provided with mold communication holes 20 a and 20 b formed in the lateral direction communicating with the corresponding mold insertion holes 8 on the left and right sides. The mold 9 is cooled through the mold cooling passages 24 a and 24 b provided in the mold 9 inserted into the mold insertion hole 8.

  That is, it is shown in FIG. 6 (BB sectional view of FIG. 3), FIG. 7 (CC sectional view of FIG. 3), FIG. 8, FIG. 9, and FIG. Thus, in the core upper mold 11, the cooling water introduced into the mold 9 from the first cooling passage 20 through the mold communication hole 20 a has an angle of approximately 120 ° C. at the center of the mold 9. Intersect, and then flow outwardly at an angle of approximately 120 ° C. with respect to these passages, and flow out of the mother die 3 through the refrigerant discharge holes 25a provided on the side surfaces of the mother die 3. I have to do it. Similarly, the cooling water introduced into the mold 9 from the first cooling passage 20 intersects the core lower mold 13 so as to form an angle of approximately 120 ° C. at the center of the mold 9. After that, it flows in an outward direction so as to form an angle of about 120 ° C. with respect to these passages, and flows out of the mother die 3 through a refrigerant discharge hole 25b provided in a side surface of the mother die 3.

  Next, press molding of an optical material performed by the optical element molding apparatus configured as described above will be described. First, a plurality of optical materials made of glass, plastic or the like are placed on the female recess 12 of the core lower mold 13 and the master 3 is heated by the heater 6 located inside and the infrared lamp 7 located outside. . At this time, since the plurality of molds 9 are arranged concentrically, heat from the inside or the outside is uniformly applied to the mold 9. When the optical material is glass, for example, heating is performed to such an extent that the glass temperature becomes equal to or higher than the glass transition point. This heating causes the optical material to soften and become plastic. Next, in this state, the upper die 1 as a pressing plate is lowered by the hydraulic mechanism to apply pressure to the lower die 2 to press the optical material. As a result, the optical material is molded into a lens shape between the lower mold 2 and the upper mold 1.

Thereafter, a refrigerant such as N ₂ is introduced into the mother die 3 through the refrigerant introduction hole 22 of the lower plate 4, passes through the groove portion 23 provided in the lower plate 4, and enters the first and second cooling flow paths 20 and 21. Through, move upward and discharge from the top. On the other hand, a part of the refrigerant passing through the first cooling flow path 20 flows laterally through the mold communication holes 20a, 20b to reach the mold cooling flow paths 24a, 24b, and the upper core 11 of the mold 9; The mold cooling channels 24 a and 24 b provided in the core lower mold 13 enter the center and then move outward, and are discharged to the outside through the refrigerant discharge holes 25 a and 25 b provided on the side of the mother die 3. Is done. At this time, since the plurality of molds 9 are arranged concentrically, the refrigerant flowing from the outside or the inside can be made to flow uniformly. In addition, since a plurality of cooling channels are provided in the mother die 3 and the cooling rate of the outer peripheral portion and the central portion of the mother die 3 is made uniform, the optical material in the die 3 can be uniformly cooled. Since the mold cooling flow paths 24a and 24b of the mold 9 are provided at positions opposite to the cooling flow paths in the mother mold 3, and the refrigerant passes through the mold cooling flow paths 24a and 24b, the cooling speed of the mold 9 is increased. can do. Thereafter, the upper die 1 as a pressing plate is raised by a hydraulic mechanism, and the molded optical lens is taken out from the lower core die 13. Since such a molding apparatus is used, the maintainability of the mold 9 is improved. In addition, it can be easily replaced as a single unit.

  In the above description, the transfer surfaces of both the core lower mold 13 and the core upper mold 11 are concave. However, the transfer surface of at least one mold can be a concave or flat surface. By making the transfer surface concave or flat, it is possible to more reliably prevent the occurrence of decentration and thickness deviation and press-mold the optical element. In the above description, the optical element such as glass or plastic is molded. However, the present invention is not limited to glass or plastic, and any other thermoplastic member may be used. .

[Embodiment 2]
FIG. 11 is an exploded perspective view of the main part of the optical element molding apparatus according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to FIG. 2 and an identical part, and description is abbreviate | omitted. Each of the mold insertion holes 8 includes a core upper mold 11 having a T-shaped cross section having a female recess 10 that forms the upper surface of the lens, a core barrel 110, and a female recess 12 that forms the lower surface of the lens. A mold 9 constituted by a core lower mold 13 having an inverted T-shaped cross section is inserted and supported by the lower plate 4. The opposing side surfaces of the core upper mold 11 and the core lower mold 13 are reduced in diameter to the same diameter, and a hollow cylindrical core cylinder 110 is inserted into the reduced diameter side surface. The mold shape of the diameter is configured. The core barrel 110 regulates the outer periphery of a plurality of optical materials sandwiched between the female concave portions of the core upper mold 11 and the core lower mold 13. The upper core mold 11, the core cylinder 110, and the lower core mold 13 are all formed of a material having predetermined heat resistance and strength, for example, hard metal.
Other configurations, operations, and effects are substantially the same as those shown in the first embodiment, and thus description thereof is omitted.

[Embodiment 3]
12 is an exploded perspective view of the main part of the optical element molding apparatus according to Embodiment 3 of the present invention, and FIG. 13 is a plan view of the main part of FIG. An optical element molding apparatus includes an upper mold 1 and a lower mold 2. The upper mold 1 is a pressing plate that is driven up and down by a hydraulic mechanism. The lower mold 2 is attached to a revolver-shaped mother mold 3 and a lower portion thereof. The lower plate 4 is used. A plurality of mold insertion holes 8 are concentrically arranged in the mother mold 3 at regular intervals on the concentric circle a, and a cylindrical mold 9 is inserted into the mold insertion hole 8. As described above, the optical element molding apparatus includes a plurality of molds 9 on the concentric circles in order to increase the manufacturing efficiency of the optical elements so that a plurality of optical elements can be molded simultaneously. A first heater insertion hole 50 is concentrically provided in a portion located between the molds 9 in the vicinity of the center portion of the mother die 3, and the heater 6 is inserted therein, and further at a position outside the concentric circle a. A second heater insertion hole 51 is provided on the concentric circle b located between the molds 9 and the heater 6 is inserted.
Between the molds 11 arranged concentrically, a first cooling flow path 20 is provided along the concentric circle a of the mold 9, and further, the first cooling channel 20 is arranged along the concentric circle or at the center on the inner peripheral side thereof. Two cooling channels (not shown) are arranged at regular intervals. The details of the first and second cooling flow paths are substantially the same as those shown in the first embodiment, and a description thereof will be omitted.

  Each of the mold insertion holes 8 includes a mold formed by an upper core mold 11 having a female recess 10 for forming the upper surface of the lens and a lower core mold 13 having a female recess 12 for forming the lower surface of the lens. 9 is inserted. Both the core upper mold 11 and the core lower mold 13 are made of a material having predetermined heat resistance and strength, for example, hard metal. The core upper mold 11 receives pressure in the direction of the arrow shown in FIG. 1 by the upper mold 1 which is a pressing plate that is driven up and down by a hydraulic mechanism.

  Next, press molding of an optical element performed by the optical element molding apparatus configured as described above will be described. First, a plurality of optical materials are placed on the female recess 12 of the core lower mold 13, and the mother mold 3 is heated by the heater 6 located inside. At this time, since the plurality of molds 9 are arranged concentrically, heat from the inside is uniformly applied to the mold 9. When the optical material is, for example, a glass material, the heating is performed to such an extent that the glass temperature is equal to or higher than the glass transition point. This heating causes the optical material to soften and become plastic. Next, in this state, the upper die 1 as a pressing plate is lowered by the hydraulic mechanism to apply pressure to the lower die 2 to press the optical material. As a result, the optical material is molded into a lens shape formed between the lower mold 2 and the upper mold 1.

Thereafter, a refrigerant such as N ₂ is introduced into the mother die 3 through the refrigerant introduction hole 22 of the lower plate 4, and the cooling rate in the mother die 3 is made uniform through a plurality of cooling channels provided in the mother die 3. Thus, the optical material in the mold 9 can be cooled uniformly. In addition, since the mold cooling flow paths 24a and 24b of the mold 9 are provided at positions facing the cooling flow path in the mother mold 3, the coolant passes through the mold cooling flow paths 24a and 24b, so that the cooling speed of the mold 9 is increased. be able to. Thereafter, the upper die 1 as a pressing plate is raised by a hydraulic mechanism, and the molded optical lens is taken out from the lower core die 13. Since such a molding apparatus is used, the maintainability of the mold 9 is improved. In addition, it can be easily replaced as a single unit.

[Embodiment 4]
14 is an exploded perspective view of the main part of the optical element molding apparatus according to Embodiment 4 of the present invention, and FIG. 15 is a sectional view taken along the line DD of FIG. In the fourth embodiment, a molding apparatus for molding an optical element by inserting the mold 9 shown in the second embodiment into the mold insertion hole 8 of the mother mold 3 shown in the third embodiment is shown. It is. Other configurations, operations, and effects are substantially the same as those shown in the third embodiment, and a description thereof will be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic explanatory drawing of the optical element shaping | molding apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is an exploded perspective view of the main part of the optical element molding apparatus according to Embodiment 1; The top view of the principal part of FIG. AA sectional drawing of FIG. Schematic explanatory drawing of the cooling flow path shown in FIG. BB sectional drawing of FIG. CC sectional drawing of FIG. The side view and top view of the upper mold | die of a core of FIG. The top view and side view of the core lower mold | type of FIG. Schematic explanatory drawing of the cooling flow path shown in FIG. The disassembled perspective view of the principal part of the shaping | molding apparatus of the optical element which concerns on Embodiment 2 of this invention. The disassembled perspective view of the principal part of the shaping | molding apparatus of the optical element which concerns on Embodiment 3 of this invention. The top view of the principal part of FIG. The disassembled perspective view of the principal part of the shaping | molding apparatus of the optical element which concerns on Embodiment 4 of this invention. DD sectional drawing of FIG.

Explanation of symbols

1 Upper mold (first mold), 2 Lower mold (second mold), 8 Mold insertion hole, 6 Heater (heat source), 7 Infrared lamp (heat source), 9 Mold, 20 First cooling flow path (Cooling channel), 20a, 20b Mold communication hole (cooling channel), 21 Second cooling channel (cooling channel), 24a, 24b Mold cooling channel, A, B Concentric circles.

Claims (8)

A first mold that is a pressing member and a second mold that includes a plurality of molds and that is molded by pressing the mold by the first mold and placing the thermoplastic member placed in the mold. In the molding device for thermoplastic members,
An apparatus for molding a thermoplastic member, wherein the molds are arranged concentrically and at equal intervals in the second mold.   The apparatus for molding a thermoplastic member according to claim 1, wherein a heat source for uniformly heating the plurality of molds is provided in the second mold.   The thermoplastic member molding apparatus according to claim 2, wherein the heat source is provided in at least one of a central portion of the second mold and an outer periphery of the second mold.   The heat source is provided concentrically in the vicinity of the center of the second mold, and is provided on the outer side of the concentric circle where the mold is disposed and concentrically between the molds. The apparatus for molding a thermoplastic member according to claim 2.   The thermoplastic member molding apparatus according to any one of claims 1 to 4, wherein a cooling channel for uniformly cooling the mold is provided in the second mold.   6. The apparatus for molding a thermoplastic member according to claim 5, wherein the cooling flow path is provided concentrically between the molds and inside the molds.   7. The molding of a thermoplastic member according to claim 6, wherein a mold cooling flow path for uniformly cooling the mold is provided in the mold, and the mold cooling flow path is communicated with the cooling flow path. apparatus. A thermoplastic member is placed in a plurality of molds arranged on the same circumference of the second mold according to any one of claims 1 to 7, and the mold is heated uniformly and then pressed. A method for molding a thermoplastic member, characterized by cooling uniformly.

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