CN107117796B - Press-molding die and method for manufacturing optical element - Google Patents
Press-molding die and method for manufacturing optical element Download PDFInfo
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- CN107117796B CN107117796B CN201710086021.3A CN201710086021A CN107117796B CN 107117796 B CN107117796 B CN 107117796B CN 201710086021 A CN201710086021 A CN 201710086021A CN 107117796 B CN107117796 B CN 107117796B
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- die
- molding
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- mold
- optical element
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
- C03B11/06—Construction of plunger or mould
- C03B11/08—Construction of plunger or mould for making solid articles, e.g. lenses
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
- C03B11/12—Cooling, heating, or insulating the plunger, the mould, or the glass-pressing machine; cooling or heating of the glass in the mould
- C03B11/122—Heating
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/40—Product characteristics
- C03B2215/46—Lenses, e.g. bi-convex
- C03B2215/48—Convex-concave
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
Abstract
Provided are a press-forming die and a method for manufacturing an optical element, wherein when the optical element is formed by using the press-forming die having an upper die, a lower die and a die case, the optical element can be manufactured with high forming precision while preventing the optical material from moving laterally. A press-molding die (1) is used for molding a glass lens, and comprises: a lower mold (4) having a molding surface (16A) for molding the lower surface of the glass lens and facing upward; an upper mold (2) having a molding surface (12A) facing downward so as to face the molding surface (16A) of the lower mold (4) for molding the upper surface of the glass lens; and a cylindrical 2 nd mold sleeve (8) having a restraining part (18) for restraining the side part of the glass lens on the inner peripheral side during pressing, wherein the restraining part (18) of the 2 nd mold sleeve (8) has: a 1 st lower surface (20) formed to face the lower mold (4); and a 2 nd lower surface (22) formed below the 1 st lower surface (20) and facing the lower mold (4).
Description
Technical Field
The present invention relates to a press-forming die and a method for manufacturing an optical element, and more particularly to a press-forming die having an upper die, a lower die, and a die case, and a method for manufacturing an optical element using the press-forming die.
Background
Conventionally, as a method for manufacturing an optical element such as a glass lens, a method of forming the optical element using a press-molding die having: a lower die having a molding surface for molding a lower surface of the optical element and facing upward; and an upper mold having a molding surface for molding an upper surface of the optical element and directed downward. The glass material such as a preform is placed on the molding surface of the lower mold, and the upper mold is lowered downward to press the glass material, whereby the molding surfaces of the upper mold and the lower mold are transferred to the upper and lower surfaces of the glass material, and an optical element such as a glass lens can be manufactured.
However, when the glass lens is molded by using such a press-molding die, if the upper die is pressed, the glass material moves in the lateral direction, and the optical surface of the molded glass lens is displaced, and thus sufficient molding accuracy cannot be obtained. On the other hand, as described in, for example, patent document 1 (japanese patent application laid-open No. 2005-336050), a press-forming die is proposed which has an annular surface formed on an inner peripheral surface of a die case so as to extend downward as a circular truncated cone (circular truncated cone). Fig. 6 is a vertical sectional view showing a press-forming die used in the related art, in which a circular truncated cone surface expanding downward is formed in a die case. As shown in fig. 6, the press-molding die 301 includes: a 1 st die case 306 surrounding the upper die 302, the lower die 304, the upper die 302, and the lower die 306; and a 2 nd die case 308 disposed within the 1 st die case 306. A circular truncated cone annular surface 308A extending downward is formed on the inner peripheral surface of the 2 nd die sleeve 308. According to the press-forming die 301, when the upper die 302 is pressed downward, the glass material spreads in the outer circumferential direction, and the circular truncated cone annular surface 308A is pressed by the peripheral edge portion of the glass material, so that the glass material can be prevented from moving in the lateral direction.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2005-336050
Disclosure of Invention
Problems to be solved by the invention
When the glass lens is molded by using the press-molding die having the circular truncated cone-shaped annular surface as described above, the glass material shrinks more greatly than the metal material constituting the press-molding die when the press-molding die is cooled while the glass material is pressed. Therefore, as shown in fig. 7, a frictional force F is generated between the circular truncated cone annular surface 308A and the peripheral edge portion of the glass material 310 in contact with the circular truncated cone annular surface 308A. When a large frictional force F acts on the peripheral edge portion of the glass material 310 from the circular truncated cone annular surface 308A during shrinkage of the glass material, the glass material 310 shrinks unevenly, and the molding accuracy of the optical element is degraded. In order to reduce the friction between the glass material and the frustoconical ring surface, the surface of the frustoconical ring surface 308A is coated so that the friction with the glass material 310 is reduced. However, even if such coating is performed, if a large number of optical elements are continuously manufactured, the coating peels off, and the molding accuracy of the optical elements is degraded.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a press-forming die capable of preventing an optical material from moving laterally and manufacturing an optical element with high molding accuracy when the optical element is molded by using the press-forming die having an upper die, a lower die, and a die sleeve.
Means for solving the problems
The press-forming die of the present invention is used for forming an optical element, and includes: a lower die having a molding surface for molding a lower surface of the optical element and facing upward; an upper mold having a molding surface for molding an upper surface of the optical element and directed downward so as to face the molding surface of the lower mold; and a cylindrical die sleeve having a restraining portion that restrains a side portion of the optical element on an inner peripheral side at the time of pressing, wherein the restraining portion of the die sleeve has: a 1 st surface formed to face the lower mold; and a 2 nd surface formed below the 1 st surface and facing the lower mold.
According to the present invention having the above configuration, since the 1 st surface and the 2 nd surface formed below the 1 st surface are provided in the constraining portion of the die case, the 1 st surface and the 2 nd surface are brought into contact with the upper surface of the outer peripheral edge of the optical material at the time of press forming. This can restrain the optical material from moving laterally during press molding. Further, since the 2 nd surface is provided below the 1 st surface, the portion of the optical material contacting the 1 st surface is thicker than the portion contacting the 2 nd surface, and the shrinkage in the thickness direction during cooling is also increased. Therefore, when cooled, only the 2 nd surface comes into contact with the optical material, and the 1 st surface is separated from the optical material. Thus, even if the optical element shrinks in the radial direction when cooled, the frictional force between the optical element and the constraining portion of the die case is very small, and the optical element can be manufactured with high molding accuracy.
The method for manufacturing an optical element of the present invention is characterized by comprising the steps of: a disposing step of disposing an optical material between an upper die and a lower die of the press-molding die; a heating step of heating the press-molding die provided with the optical material; and a press forming step of applying a press pressure to the heated press forming die to press form the optical material.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to provide a press-forming die capable of preventing an optical material from moving laterally and manufacturing an optical element with high molding accuracy when the optical element is molded by using the press-forming die having an upper die, a lower die, and a die case.
Drawings
Fig. 1 is a vertical sectional view showing a press-forming die according to embodiment 1 of the present invention.
Fig. 2 is an enlarged vertical sectional view showing a vicinity of a constraining portion of a 2 nd mold sleeve in the production of a glass lens using the press-molding die according to embodiment 1.
Fig. 3 is a vertical sectional view showing a press-forming die according to embodiment 2 of the present invention.
Fig. 4 is a vertical sectional view showing a press-forming die according to embodiment 3 of the present invention.
Fig. 5 is a graph showing thickness errors with respect to design values in comparative examples and examples.
Fig. 6 is a vertical sectional view showing a press-forming die in which a circular truncated cone surface expanding downward is formed in a die case, which has been used conventionally.
Fig. 7 is an enlarged vertical sectional view showing the vicinity of a circular truncated cone surface in a press forming die used in the related art.
Description of the reference symbols
1: punching and forming a die;
2: an upper die;
4: a lower die;
6: 1, a die sleeve;
8: a 2 nd die sleeve;
10: a base;
12: a molding section;
12A: molding surface;
14: a base;
16: a molding section;
16A: molding surface;
18: a restraint section;
19: 1 st cylindrical part;
20: 1, lower surface;
22: a 2 nd lower surface;
24: a 2 nd cylindrical part;
101: punching and forming a die;
108: a 2 nd die sleeve;
118: a restraint section;
119: 1 st cylindrical part;
120: 1, lower surface;
121: a 2 nd cylindrical part;
122: a 2 nd lower surface;
124: a 3 rd cylindrical part;
201: punching and forming a die;
208: a 2 nd die sleeve;
218: a restraint section;
219: 1 st cylindrical part;
220: 1, lower surface;
221: a 2 nd cylindrical part;
222: a 2 nd lower surface;
224: a 3 rd cylindrical part.
Detailed Description
The following describes in detail a 1 st embodiment of a press mold according to the present invention with reference to the drawings.
Fig. 1 is a vertical sectional view showing a press-forming die according to embodiment 1 of the present invention. As shown in the drawing, a press-forming die 1 of the present embodiment includes: an upper mold 2 having a molding surface 12A corresponding to an upper surface of the optical element at a lower portion thereof; a lower mold 4 having a molding surface 16A corresponding to a lower surface of the optical element at an upper portion thereof; a 1 st die case 6 (outer die case) provided on the outer peripheries of the upper die 2 and the lower die 4; and a 2 nd die sleeve 8 (inner die sleeve) which is provided on the outer periphery of the upper die and inside the 1 st die sleeve 6, and has a restraining portion 18 which restrains the side portion of the glass material. The press-molding die 1 of the present embodiment is used to manufacture a meniscus lens having a convex one surface and a concave other surface.
The upper die 2 has: a base 10 formed in a cylindrical shape and a molding portion 12 protruding downward from a lower portion of the base 10. The molding portion 12 is cylindrical with a smaller diameter than the base portion 10, and a convex molding surface 12A corresponding to the concave surface of the manufactured glass lens (optical element) is formed on the lower surface.
The lower die 4 has: a base portion 14 formed in a cylindrical shape, and a molding portion 16 projecting upward from an upper portion of the base portion 14. The molding portion 16 is cylindrical with a smaller diameter than the base portion 14, and a concave molding surface 16A corresponding to the convex surface of the glass lens to be manufactured is formed on the upper surface.
The 1 st die case 6 is formed of a member formed in a substantially cylindrical shape. The inner diameter of the 1 st die case 6 is equal to the outer diameter of the base 10 of the upper die 2. The upper die 2 is inserted into the 1 st die case 6 from above. The inner diameter of the lower portion of the 1 st die case 6 is formed to be substantially equal to the outer diameter of the molding portion 16 of the lower die 4. The molding portion 16 of the lower die 4 is inserted into the 1 st die case 6 from below, and the lower end portion of the 1 st die case 6 abuts against the upper surface of the peripheral edge portion of the base portion 14 of the lower die 4.
The 2 nd die sleeve 8 is annular, and the outer peripheral surface of the 2 nd die sleeve is cylindrical surface-shaped. Further, a 1 st cylindrical portion 19, a 1 st lower surface 20, a 2 nd lower surface 22, and a 2 nd cylindrical portion 24 are continuously formed from above on the inner periphery of the 2 nd die sleeve 8. The 1 st cylindrical portion 19 is cylindrical and extends in the vertical direction. The inner diameter of the 1 st cylindrical portion 19 is substantially equal to the outer diameter of the molding portion 12 of the upper mold 2. The 1 st lower surface 20 is formed as a circular truncated cone surface extending downward, and the 1 st lower surface 20 faces obliquely downward toward the center of the press mold 1. The 2 nd lower surface 22 is an annular surface centered on the central axis (indicated by a chain line in the drawing) of the press mold 1, and is perpendicular to the central axis of the press mold 1. The No. 2 lower surface 22 was mirror-finished, and the FCVA film was coated. The 2 nd cylindrical portion 24 has a cylindrical surface shape. The surface area of the 2 nd lower surface 22 is preferably smaller than the surface area of the 1 st lower surface 20, and more preferably, the projected area of the 2 nd lower surface 22 in the central axis direction of the press-forming die 1 is smaller than the projected area of the 1 st lower surface 20 in the central axis direction of the press-forming die 1. In the present embodiment, the constraining section 18 of the 2 nd die set 8 is constituted by the 1 st lower surface 20, the 2 nd lower surface 22, and the 2 nd cylindrical section 24 of the 2 nd die set 8.
The 2 nd die set 8 is disposed above the molding portion 16 of the lower die 4 and on the outer periphery of the molding portion 12 of the upper die 2 inside the 1 st die set 6, and the molding portion 12 of the upper die 2 is inserted inside. In a state where the press forming die 1 is assembled, a lower peripheral edge portion of the base portion 10 of the upper die 2 abuts on an upper surface of the 2 nd die case 8. In a state where the press-forming die 1 is assembled, the central axes of the upper die 2, the lower die 4, the 1 st die case 6, and the 2 nd die case 8 are aligned. In fig. 1, the bottom of the 2 nd die case 8 is in contact with the upper surface of the lower die 4, but the pressing is started from a state of being separated during the pressing.
Fig. 2 is an enlarged vertical sectional view showing the vicinity of the constraining section 8 of the 2 nd mold sleeve in the production of a glass lens using the press-molding die of embodiment 1. In the production of a glass lens, a glass material 26 such as a preform is placed on the molding surface 16A of the lower mold 4 with the upper mold 2 and the 2 nd mold sleeve 8 removed. And the 2 nd die set 8 is disposed in the 1 st die set 6, and then the upper die 2 is disposed in the 1 st die set 6. Thereby, the press-molding die 1 in which the glass material 26 is arranged is heated to a temperature equal to or higher than the sag point of the glass.
When the glass material 26 is sufficiently heated to a temperature equal to or higher than the glass sagging point, the upper mold 2 is pressed downward by a press device such as a hydraulic actuator while supporting the lower mold 4. By pressing the upper die 2 downward, the upper die 2 and the 2 nd die set 8 are lowered while the central axes of the upper die 2 and the 2 nd die set 8 are kept aligned with the central axis of the lower die 4 by the 1 st die set 6.
When the upper mold 2 is lowered, first, the central portion of the molding surface 12A of the upper mold 2 abuts on the upper surface of the glass material 26. Then, the upper mold 2 is lowered, whereby the glass material 26 is crushed and spread laterally. At this time, as shown in fig. 2, the 2 nd lower surface 22 of the 2 nd die case 8 is abutted on the peripheral edge portion of the upper surface of the glass material 26, and the 1 st lower surface 20 is abutted inside the portion of the upper surface of the glass material 26 abutted on the 2 nd lower surface 22. Thereby, the lateral movement of the glass material 26 is reliably prevented. In this state, the upper mold 2 is further pressed until the upper surface of the upper mold 2 abuts against the upper surface of the 1 st die case 6, whereby the molding surfaces 12A, 16A of the upper mold 2 and the lower mold 4 are transferred to the upper and lower surfaces of the glass material 26. At this time, although the inner portion of the 2 nd lower surface 22 of the glass material 26 (the portion below the 1 st lower surface 20) is moved upward, it does not necessarily come into contact with the entire 1 st lower surface 20, and a gap is formed between the upper portion of the 1 st lower surface 20 and the glass material 26. Thus, by forming a gap between the upper portion of the 1 st lower surface 20 and the glass material 26, it is possible to absorb the variation in volume of the glass material 26.
Then, the press-forming die 1 is cooled while the upper die 2 is under the press pressure. At this time, the portion of the glass material 26 abutting the 1 st lower surface 20 is thicker than the portion abutting the 2 nd lower surface 22. Therefore, the portion of the glass material 26 abutting the 1 st lower surface 20 and the portion abutting the 2 nd lower surface 22 are greatly contracted in the thickness direction. Since a pressing pressure is applied to the upper mold 2 during cooling, the 2 nd lower surface 22 is kept in contact with the upper surface of the glass material 26, but the glass material 26 is separated from the 1 st lower surface 20. Further, assuming that the glass material 26 is separated from the 1 st lower surface 20, the pressing pressure acting between the glass material 26 and the 1 st lower surface 20 is also very small.
When the glass material 26 contracts, the outer peripheral portion of the glass material 26 moves toward the radial center. At this time, a frictional force acts between the upper surface of the outer peripheral portion of the glass material 26 and the 2 nd lower surface 22 of the 2 nd die case 8. However, according to the present embodiment, as described above, the 1 st lower surface 20 is separated from the glass material 26, or the pressing pressure acting between the glass material 26 and the 1 st lower surface 20 is very small, and therefore the frictional force acting in the radial direction between the glass material 26 and the constraining portion 18 of the 2 nd die case 8 is very small. Therefore, the glass material 26 is uniformly shrunk in the radial direction.
As described above, according to the present embodiment, the 1 st lower surface 20 and the 2 nd lower surface 22 are brought into contact with the upper surface of the outer peripheral edge of the glass material 26 during press forming. This can restrain the glass material 26 from moving laterally during press molding. Further, according to the present embodiment, the 1 st lower surface 20 is separated from the upper surface of the glass material 26 during cooling. Accordingly, even if the glass material 26 shrinks when the glass material 26 is cooled, a frictional force is generated only between the 2 nd lower surface 22 and the glass material 26, and the frictional force acting in the radial direction of the glass material 26 from the constraining section 18 is extremely small, and a glass lens can be manufactured with high molding accuracy.
Further, according to the present embodiment, the surface area of the 2 nd lower surface 22 is smaller than the surface area of the 1 st lower surface 20. This can further reduce the frictional force between the 2 nd lower surface 22 and the glass material 26 during cooling.
Further, according to the present embodiment, by providing the 1 st lower surface 20, a gap is generated between the glass material 26 and the 1 st lower surface 20 thereunder, whereby a volume error of the glass material 26 can be absorbed.
The press-forming die according to embodiment 2 of the present invention will be described below. The same components as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
Fig. 3 is a vertical sectional view showing a press-forming die according to embodiment 2 of the present invention. As shown in the drawing, the press-forming die 101 of the present embodiment includes: an upper mold 2 having a molding surface 12A corresponding to an upper surface of the optical element at a lower portion thereof; a lower mold 4 having a molding surface 16A corresponding to a lower surface of the optical element at an upper portion thereof; a 1 st die case 6 provided on the outer peripheries of the upper die 2 and the lower die 4; and a 2 nd die case 108 which is provided on the outer periphery of the upper die and inside the 1 st die case 6 and has a restraining portion 118 for restraining the glass material as will be described later. The upper die 2, the lower die 4, and the 1 st die case 6 have the same configuration as that of embodiment 1, and detailed description thereof is omitted.
The 2 nd die sleeve 108 is annular and has a cylindrical outer peripheral surface. Further, a 1 st cylindrical portion 119, a 1 st lower surface 120, a 2 nd cylindrical portion 121, a 2 nd lower surface 122, and a 3 rd cylindrical portion 124 are continuously formed from above on the inner periphery of the 2 nd die sleeve 108. The 1 st cylinder portion 119 has a cylindrical surface shape and extends in the vertical direction. The inner diameter of the 1 st cylindrical portion 119 is substantially equal to the outer diameter of the molding portion 12 of the upper die 2. The 1 st lower surface 120 is formed so as to face obliquely downward toward the center of the press mold 101 and has a circular truncated cone-shaped surface. The 2 nd cylindrical portion 121 has a cylindrical surface shape and extends in the vertical direction. The inner diameter of the 2 nd cylindrical portion 121 is larger than the 1 st cylindrical portion 119 and smaller than the 3 rd cylindrical portion 124. The 2 nd lower surface 122 is an annular surface centered on the central axis (indicated by a chain line in the drawing) of the press mold 101, and is perpendicular to the central axis of the press mold 101. The No. 2 lower surface 122 is mirror-finished and coated with an FCVA film. The 3 rd cylindrical portion 124 has a cylindrical surface shape.
The surface area of the 2 nd lower surface 122 is preferably smaller than the surface area of the 1 st lower surface 120, and more preferably, the projected area of the 2 nd lower surface 122 in the central axis direction of the press mold 101 is smaller than the projected area of the 1 st lower surface 120 in the central axis direction of the press mold 101. In the present embodiment, the constraining portion 118 of the 2 nd die 108 is constituted by the 1 st lower surface 120, the 2 nd cylindrical portion 121, the 2 nd lower surface 122, and the 3 rd cylindrical portion 124 of the 2 nd die 108.
The 2 nd die set 108 is disposed above the molding portion 16 of the lower die 4 and on the outer periphery of the molding portion 12 of the upper die 2 inside the 1 st die set 6, and the molding portion 12 of the upper die 2 is inserted inside the 1 st cylindrical portion 119. In a state where the press forming die 101 is assembled, the lower peripheral edge portion of the base portion 10 of the upper die 2 abuts against the upper surface of the 2 nd die case 8. When the press-forming die 101 is assembled, the central axes of the upper die 2, the lower die 4, the 1 st die case 6, and the 2 nd die case 108 are aligned. Fig. 3 shows a state where the bottom of the 2 nd die case 108 is in contact with the upper surface of the lower die 4, but the pressing is started from a state where it is separated during the pressing.
The same operational advantages as those of the press mold 1 according to embodiment 1 are obtained by the press mold 101 according to embodiment 2.
That is, when the upper mold 2 is lowered during press forming, the glass material is crushed and spread laterally. At this time, the 2 nd lower surface 122 of the 2 nd die case 108 is abutted on the peripheral edge portion of the upper surface of the glass material, and the 1 st lower surface 120 is abutted on the inner side of the portion of the upper surface of the glass material abutted with the 2 nd lower surface 122. Thereby, the glass material can be restrained from moving laterally.
Further, since the portion of the glass material in contact with the 1 st lower surface 120 is thicker than the portion in contact with the 2 nd lower surface 122, the portion in contact with the 1 st lower surface 120 contracts more in the thickness direction during cooling than the portion in contact with the 2 nd lower surface 122. Since the pressing pressure is applied to the upper mold 2 during cooling, only the 2 nd lower surface 122 comes into contact with the glass material, and the 1 st lower surface 120 is separated from the glass material. Thus, even if the glass material shrinks in the radial direction during cooling, a frictional force is generated only between the 2 nd lower surface 122 and the glass material, and the frictional force acting on the glass material is very small, so that the glass lens can be manufactured with high molding accuracy.
Further, according to the present embodiment, the surface area of the 2 nd lower surface 122 is smaller than the surface area of the 1 st lower surface 120. This reduces the frictional force between the 2 nd lower surface 122 and the glass material during cooling.
Further, according to the present embodiment, by providing the 1 st lower surface 120, a gap is generated between the glass material and the 1 st lower surface 120 thereunder, whereby a volume error of the glass material can be absorbed.
In the present embodiment, the case where the 2 nd lower surface 122 is parallel to a plane perpendicular to the central axis of the press mold 101 is described, but the present invention is not limited thereto, and the 2 nd lower surface 122 may be formed so as to be directed obliquely downward toward the center of the press mold 101. When the 1 st lower surface 120 and the 2 nd lower surface 122 are formed so as to face obliquely downward toward the center of the press mold 101 in this manner, it is preferable that the angle of the 2 nd lower surface 122 with respect to the direction perpendicular to the center axis of the press mold 101 (i.e., the angle of the 2 nd lower surface 122 with respect to the left-right direction in fig. 3) be smaller than the angle of the 1 st lower surface 120 with respect to the direction perpendicular to the center axis of the press mold 101. Preferably, the angle of the 1 st lower surface 120 with respect to the direction perpendicular to the central axis of the press mold 101 is 30 ° or less, and the angle of the 2 nd lower surface 122 with respect to the direction perpendicular to the central axis of the press mold 101 is 10 ° or less.
The press-forming die according to embodiment 3 of the present invention will be described below. The same components as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
Fig. 4 is a vertical sectional view showing a press-forming die according to embodiment 3 of the present invention. As shown in the drawing, a press-forming die 201 of the present embodiment includes: an upper mold 2 having a molding surface 12A corresponding to an upper surface of the optical element at a lower portion thereof; a lower mold 4 having a molding surface 16A corresponding to a lower surface of the optical element at an upper portion thereof; a 1 st die case 6 provided on the outer peripheries of the upper die 2 and the lower die 4; and a 2 nd die sleeve 208 provided on the outer periphery of the upper die and inside the 1 st die sleeve 6, and having a constraining portion 218 for constraining the glass material as described later. The upper die 2, the lower die 4, and the 1 st die case 6 have the same configuration as that of embodiment 1, and detailed description thereof is omitted.
The 2 nd die sleeve 208 is annular and has a cylindrical outer peripheral surface. Further, a 1 st cylindrical portion 219, a 1 st lower surface 220, a 2 nd cylindrical portion 221, a 2 nd lower surface 222, and a 3 rd cylindrical portion 224 are continuously formed from above on the inner periphery of the 2 nd die sleeve 208.
The 1 st cylinder part 219 has a cylindrical surface shape and extends in the vertical direction. The inner diameter of the 1 st cylindrical portion 219 is substantially equal to the outer diameter of the molding portion 12 of the upper die 2. The 1 st lower surface 220 is an annular surface centered on the central axis (indicated by a chain line in the drawing) of the press mold 201, and is perpendicular to the central axis of the press mold 201. The outer diameter of the 1 st lower surface 220 is equal to the inner diameter of the 2 nd cylindrical portion 221. The 2 nd cylindrical portion 221 has a cylindrical surface shape and extends in the vertical direction. The inner diameter of the 2 nd cylindrical portion 221 is larger than that of the 1 st cylindrical portion 219 and smaller than that of the 3 rd cylindrical portion 224. The 2 nd lower surface 222 is an annular surface centered on the central axis (indicated by a chain line in the drawing) of the press mold 201, and is perpendicular to the central axis of the press mold 201. The No. 2 lower surface 222 is mirror-finished, and the FCVA film is coated. The 3 rd cylindrical portion 224 has a cylindrical surface shape.
The surface area of the 2 nd lower surface 222 is preferably smaller than the surface area of the 1 st lower surface 220, and more preferably, the projected area of the 2 nd lower surface 222 in the central axis direction of the press-forming die 201 is smaller than the projected area of the 1 st lower surface 220 in the central axis direction of the press-forming die 201. In the present embodiment, the 1 st lower surface 220, the 2 nd cylindrical portion 221, the 2 nd lower surface 222, and the 3 rd cylindrical portion 224 of the 2 nd die holder 208 constitute the constraining portion 218 of the 2 nd die holder 208.
The 2 nd die sleeve 208 is disposed above the molding portion 16 of the lower die 4 and on the outer periphery of the molding portion 12 of the upper die 2 inside the 1 st die sleeve 6, and the molding portion 12 of the upper die 2 is inserted inside the 1 st cylindrical portion 219. In a state where the press-forming die 201 is assembled, the lower peripheral edge portion of the base portion 10 of the upper die 2 abuts on the upper surface of the 2 nd die case 8. In a state where the press-forming die 201 is assembled, the central axes of the upper die 2, the lower die 4, the 1 st die case 6, and the 2 nd die case 208 are aligned. Fig. 4 shows a state where the bottom of the 2 nd die case 208 is in contact with the upper surface of the lower die 4, but the pressing is started from a state where it is separated during the pressing.
The same operational advantages as those of the press mold 1 according to embodiment 1 are obtained by the press mold 201 according to embodiment 3.
That is, when the upper mold 2 is lowered during press forming, the glass material is crushed and spread laterally. At this time, the 2 nd lower surface 222 of the 2 nd die case 208 is abutted on the peripheral edge portion of the upper surface of the glass material, and the 1 st lower surface 220 is abutted on the inner side of the portion of the upper surface of the glass material abutted on the 2 nd lower surface 222. This can reliably restrain the glass material from moving laterally.
Further, since the portion of the glass material in contact with the 1 st lower surface 220 is thicker than the portion in contact with the 2 nd lower surface 222, the portion in contact with the 1 st lower surface 220 contracts more in the thickness direction during cooling than the portion in contact with the 2 nd lower surface 222. Further, since the pressing pressure is applied to the upper mold 2 also during cooling, only the 2 nd lower surface 222 abuts against the glass material, and the 1 st lower surface 220 is separated from the glass material. Accordingly, even if the glass material shrinks in the radial direction during cooling, a frictional force is generated only between the 2 nd lower surface 222 and the glass material, and the frictional force acting on the glass material is extremely small, so that the glass lens can be manufactured with high molding accuracy.
Further, according to the present embodiment, the surface area of the 2 nd lower surface 222 is smaller than the surface area of the 1 st lower surface 220. This reduces the frictional force between the 2 nd lower surface 222 and the glass material during cooling.
Further, according to the present embodiment, by providing the 1 st lower surface 220, a gap is generated between the glass material and the 1 st lower surface 220 thereunder, whereby a volume error of the glass material can be absorbed.
In the present embodiment, the case where the 2 nd lower surface 222 is parallel to a plane perpendicular to the central axis of the press mold 201 is described, but the present invention is not limited thereto, and the 2 nd lower surface 222 may be formed so as to be directed obliquely downward toward the center of the press mold 201.
In addition, in the above embodiments, the case where the glass lens is manufactured by press-molding a glass material has been described as an example, but the present invention is not limited to this, and can be applied to the case where an optical element made of another material such as a plastic lens is press-molded.
Here, the inventors continuously manufactured 30 glass lenses using the press-forming mold (example) according to embodiment 1 described with reference to fig. 1 and the conventional press-forming mold (comparative example) described with reference to fig. 6, measured the thicknesses of three points on the XY axes orthogonal to each other on the manufactured glass lenses, and calculated the error from the design value. Fig. 5 is a graph showing thickness errors with respect to design values in comparative examples and examples. As shown in fig. 5, the press-forming die of the comparative example tends to have a thickness error that increases as the number of presses (shots) increases. In contrast, according to the press-forming die of the embodiment, even if the press is increased, the error from the design value is changed very little. Thus, the present invention confirmed that an optical element with high molding accuracy can be manufactured even when a large number of glass lenses are continuously manufactured.
The invention is summarized below with reference to the appended drawings.
As shown in fig. 1, a press-molding die 1 according to embodiment 1 of the present invention is used for molding a glass lens, and includes: a lower mold 4 having an upward molding surface 16A for molding a lower surface of the glass lens; an upper mold 2 having a molding surface 12A facing downward so as to face the molding surface 16A of the lower mold 4 for molding the upper surface of the glass lens; and a cylindrical 2 nd mold 8 having a constraining section 18 for constraining the side section of the glass lens to the inner peripheral side at the time of pressing, the constraining section 18 of the 2 nd mold 8 having: a 1 st lower surface 20 formed to face the lower mold 4; and a 2 nd lower surface 22 formed below the 1 st lower surface 20 and facing the lower mold 4.
As shown in fig. 3, a press-molding die 101 according to embodiment 2 of the present invention is used for molding a glass lens, and includes: a lower mold 4 having an upward molding surface 16A for molding a lower surface of the glass lens; an upper mold 2 having a molding surface 12A facing downward so as to face the molding surface 16A of the lower mold 4 for molding the upper surface of the glass lens; and a cylindrical 2 nd mold 108 having a constraining section 118 for constraining the side section of the glass lens on the inner peripheral side at the time of pressing, the constraining section 118 of the 2 nd mold 108 having: a 1 st lower surface 120 formed to face the lower mold 4; and a 2 nd lower surface 122 formed below the 1 st lower surface 120 and formed to face the lower mold 4.
As shown in fig. 4, a press-molding die 201 according to embodiment 3 of the present invention is used for molding a glass lens, and includes: a lower mold 4 having an upward molding surface 16A for molding a lower surface of the glass lens; an upper mold 2 having a molding surface 12A facing downward so as to face the molding surface 16A of the lower mold 4 for molding the upper surface of the glass lens; and a cylindrical 2 nd mold 208 having a constraining section 218 for constraining the side section of the glass lens to the inner peripheral side at the time of pressing, the constraining section 218 of the 2 nd mold 208 having: a 1 st lower surface 220 formed to face the lower mold 4; and a 2 nd lower surface 222 formed below the 1 st lower surface 220 and formed to face the lower mold 4.
Claims (8)
1. A press-forming die for forming an optical element, the press-forming die comprising:
a lower die having a molding surface for molding a lower surface of the optical element and facing upward; an upper mold having a molding surface for molding an upper surface of the optical element and directed downward so as to face the molding surface of the lower mold; and a cylindrical die sleeve having a restraining portion for restraining the side portion of the optical element on the inner peripheral side during pressing,
wherein the content of the first and second substances,
the constraining portion of the die case has:
a 1 st surface formed so as to face obliquely downward toward the center of the press mold;
a 2 nd surface which is formed below the 1 st surface, is continuous with the 1 st surface, and is perpendicular to the central axes of the upper die and the lower die; and
and a cylindrical portion formed in a cylindrical surface shape, which is formed below the 2 nd surface and is continuous with the 2 nd surface.
2. A press-forming die for forming an optical element, the press-forming die comprising:
a lower die having a molding surface for molding a lower surface of the optical element and facing upward; an upper mold having a molding surface for molding an upper surface of the optical element and directed downward so as to face the molding surface of the lower mold; and a cylindrical die sleeve having a restraining portion for restraining the side portion of the optical element on the inner peripheral side during pressing,
wherein the content of the first and second substances,
the constraining portion of the die case has:
a 1 st surface formed to face the lower mold; and
a 2 nd surface formed below the 1 st surface and facing the lower mold,
a cylindrical vertical surface parallel to the central axis of the press-molding die is sandwiched between the 1 st surface and the 2 nd surface,
the 1 st surface and the 2 nd surface are configured to abut against the optical element during pressing.
3. The punch forming mold according to claim 2,
the 1 st surface is formed to face obliquely downward toward the center of the press forming die.
4. The punch forming mold according to claim 2 or 3, wherein,
the 2 nd surface is formed to face obliquely downward toward the center of the press forming die.
5. The punch forming mold according to claim 2,
the 1 st surface and the 2 nd surface are formed to face obliquely downward toward the center of the press molding die,
the angle of the 2 nd surface relative to the direction vertical to the central axis of the punch forming die is smaller than the angle of the 1 st surface relative to the direction vertical to the central axis of the punch forming die.
6. The punch forming mold according to claim 1 or 2, wherein,
the molding surface of the lower die is concave,
the molding surface of the upper die is convex.
7. The punch forming mold according to claim 1 or 2, wherein,
the surface area of the 2 nd surface is smaller than the surface area of the 1 st surface.
8. A method of manufacturing an optical element, the method comprising the steps of:
a disposing step of disposing an optical material between the upper die and the lower die of the press-forming die according to any one of claims 1 to 7;
a heating step of heating the press-molding die provided with the optical material; and
and a stamping forming step, wherein stamping pressure is applied to the heated stamping forming die to stamp the optical material.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016-033077 | 2016-02-24 | ||
| JP2016033077A JP6688630B2 (en) | 2016-02-24 | 2016-02-24 | Press mold and method for manufacturing optical element |
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| CN107117796A CN107117796A (en) | 2017-09-01 |
| CN107117796B true CN107117796B (en) | 2021-06-08 |
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| JP (1) | JP6688630B2 (en) |
| KR (1) | KR20170099768A (en) |
| CN (1) | CN107117796B (en) |
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| JP6583704B2 (en) * | 2014-09-25 | 2019-10-02 | ポーラ化成工業株式会社 | Screening method for pigmentation improvers |
| EP3659592A4 (en) | 2017-07-27 | 2021-05-26 | Korpharm Co., Ltd. | Novel benzylideneacetone derivative and use thereof |
| JP7407528B2 (en) * | 2019-07-05 | 2024-01-04 | Hoya株式会社 | glass lens mold |
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|---|---|---|---|---|
| JPH069231A (en) * | 1992-06-26 | 1994-01-18 | Matsushita Electric Ind Co Ltd | Die for optical glass element and method for forming optical glass element |
| CN1733631A (en) * | 2004-08-02 | 2006-02-15 | 亚洲光学股份有限公司 | Glass mold forming device |
| CN102557394A (en) * | 2010-11-19 | 2012-07-11 | 柯尼卡美能达精密光学株式会社 | Glass optical element and method for manufacturing the same |
| JP2012158490A (en) * | 2011-01-31 | 2012-08-23 | Asahi Glass Co Ltd | Apparatus and method for manufacturing optical element |
| CN104829094A (en) * | 2014-02-10 | 2015-08-12 | Hoya株式会社 | Glass lens mold and glass lens manufacturing method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5458463B2 (en) * | 2006-07-03 | 2014-04-02 | 住友電気工業株式会社 | Manufacturing method of ceramic optical parts |
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- 2017-02-17 CN CN201710086021.3A patent/CN107117796B/en active Active
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH069231A (en) * | 1992-06-26 | 1994-01-18 | Matsushita Electric Ind Co Ltd | Die for optical glass element and method for forming optical glass element |
| CN1733631A (en) * | 2004-08-02 | 2006-02-15 | 亚洲光学股份有限公司 | Glass mold forming device |
| CN102557394A (en) * | 2010-11-19 | 2012-07-11 | 柯尼卡美能达精密光学株式会社 | Glass optical element and method for manufacturing the same |
| JP2012158490A (en) * | 2011-01-31 | 2012-08-23 | Asahi Glass Co Ltd | Apparatus and method for manufacturing optical element |
| CN104829094A (en) * | 2014-02-10 | 2015-08-12 | Hoya株式会社 | Glass lens mold and glass lens manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI713699B (en) | 2020-12-21 |
| CN107117796A (en) | 2017-09-01 |
| JP2017149607A (en) | 2017-08-31 |
| JP6688630B2 (en) | 2020-04-28 |
| TW201733921A (en) | 2017-10-01 |
| KR20170099768A (en) | 2017-09-01 |
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