JP2005336050A - Molding die for glass lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding die for a glass lens providing a good optical face. <P>SOLUTION: The molding die to mold the glass lens by heating and pressurizing a set lens glass material is composed of a tube-like lower guiding pattern having a first annular wall to define a first inner aperture, in which a first contact surface is formed on the first annular wall, a second contact surface having a second annular wall to define a second inner aperture so that it can perform the relative displacement opposite to the upper end of the lower guiding pattern, in which a second annular wall is thrust corresponding to the first contact surface, a tube-like upper guiding pattern in which a norm part having a truncated cone annular face spread out from the inner periphery of the second inner aperture side to the second contact surface is formed, a female mold inserted to the first inner aperture of the lower guiding pattern, in which the first surface is formed on the glass material pressurized end and a cope inserted to the second inner aperture of the upper guiding pattern so that it can slide between the proximal position spaced in a predetermined distance from the female mold upper part to the female mold, in which the second face is formed on the opposite glass material pressurized end. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding die used for molding an optical lens or the like.

  1 and 2 are cross-sectional views schematically showing a mold used when molding a general optical glass lens. The mold 9 has a substantially cylindrical guide mold 91 in which an inner hole 910 is defined, and has a surface 92a having a predetermined shape to be one of cavities described later, and a collar portion 92b projects in a radial direction from a lower end portion. A lower mold 92 is inserted, and an upper mold 93 having a surface 92a and a surface 93a having a predetermined shape which is the other of the cavity and having a flange portion 93b projecting radially from the upper end portion is inserted. A lens glass material 94 is set on the lower die 92 in the formed cavity 95, the lower die 92 is fixed together with the guide die 11, they are heated, and the upper die 93 is pushed in. Subsequently, the glass lens 96 is shape | molded by passing through cooling of a post process. The lower end portion of the upper die 93 is guided when the upper die 93 is pushed in, because the portion where the surface 93a is formed is smaller in diameter than the main body portion of the upper die 93 to form an annular stepped portion 93c. It is possible to avoid a damage to the outer peripheral surface of the surface 93a, which is a male surface, by forming a refuge on the upper side of the mold 91, for example.

  However, when the glass lens 96 is manufactured by the mold 9 having such a configuration, as shown in FIGS. 2 and 3, the center portion 963 is pushed by the surface 93a of the upper die 93, but the outer peripheral portion 961 is Depending on how much the lens glass material 94 is filled in the cavity 95, it cannot be limited only by the surface 93a of the upper mold 93. There is a problem that the surface accuracy of the lens surface is lowered due to biting and the like, and the yield of a lens having finally sufficient performance is low.

  Furthermore, as shown in FIG. 4, when the lens glass material 94 is set on the upper mold 93 or the lower mold 92 in the cavity 95 so as to deviate from the central axis, as shown in FIG. In addition, the optical surface of the molded lens 97 is also greatly deviated, and there is a problem in that sufficient accuracy cannot be finally obtained for the lens.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a glass lens mold that provides a good optical surface.

  In order to achieve the above object, a glass lens molding die of the present invention is a molding die for molding a glass lens by heating and pressurizing a set lens glass material, and defines a first inner hole. A cylindrical lower guide mold having one annular wall and having a first contact surface formed on the first annular wall, and a second inner hole so as to be movable relative to the upper end of the lower guide mold A second annular wall defining a first contact surface corresponding to the first contact surface and an inner peripheral surface on the second inner hole side. A glass material pressurizing end is inserted into a cylindrical upper guide type in which a reference portion having a circular truncated conical ring surface is formed so as to go to the second contact surface and a first inner hole of the lower guide type And is inserted into the second inner hole of the upper guide type so as to be slidable between the lower mold and a position close to the lower mold from above the lower mold. The upper die is formed by an upper die having a second surface formed on the pressing end of the child material, the first contact surface of the lower guide die and the second contact surface of the upper guide die are brought into contact with each other. The cavity is formed by the first surface of the lower mold, the second surface of the upper mold, and the circular truncated cone surface of the reference portion by being moved to the close position. Configured to be able to.

  According to this configuration, the outer peripheral surface of the entire glass lens formed by the cavity defined by the first surface of the lower mold, the second surface of the upper mold, and the circular truncated cone surface of the reference portion Since the thickness can be reduced, shrinkage distortion due to the difference in thickness in the subsequent cooling process can be suppressed, and deformation of the lens surface can be effectively suppressed. Have

  The first inner hole of the lower guide type has a large diameter part on the upper guide type side and a small diameter part on the side facing the upper guide type, and the first contact surface has the large diameter part and the small diameter part. It is good also as a structure provided between the parts.

  According to this configuration, the sliding distance of the guide mold can be effectively controlled, so that the thickness of the glass lens to be molded can be efficiently controlled.

  Further, the second annular wall of the upper guide type has a small diameter formed corresponding to the large diameter part on the opposite side of the lower guide type and the large diameter part of the first inner hole on the lower guide type side. And the second contact surface may be formed at the lower end of the second annular wall near the small diameter portion.

  According to this configuration, the guide type sliding distance can be controlled more effectively.

  In addition, the second inner hole of the upper guide type includes a first annular surface portion interposed between the first sleeve portion on the side into which the upper die is inserted and the first sleeve portion. The hole diameter of the reference portion that is smaller than the hole diameter of the second sleeve portion with the second annular surface portion interposed between the second sleeve portion that is smaller than the hole diameter of the sleeve portion and the second sleeve portion is the smallest. A reference portion is interposed between the third sleeve portion that is continuous with a certain peripheral edge of the upper end portion and the third sleeve portion so as to rise from the second contact surface in an annular shape to a predetermined height. It is good also as a structure in which the 4th sleeve part which followed the lower end part peripheral edge with the largest hole diameter, and was formed.

  According to this configuration, there is an effect that the sliding distance in the upper guide mold of the upper mold can be effectively controlled.

  Further, the lower die is sized to be fitted into the small diameter portion of the first inner hole of the lower guide type and slightly protrude into the large diameter portion. Thus, when the first and second contact surfaces of the lower and upper guide types come into contact with each other, the lower mold extends into the fourth sleeve portion of the second inner hole of the upper guide type, and the second surface The lower block is formed so as to be in the fourth sleeve portion, and the flange portion that protrudes from the lower end portion of the lower block and whose protruding edge contacts the lower end surface of the first annular wall is formed. Also good.

  According to this configuration, the lower mold has an effect of effectively controlling the thickness of the glass lens by being inserted into the lower guide mold with a predetermined depth and restrained.

  Further, the upper mold has a first insertion portion that is inserted into the first sleeve portion of the second inner hole and contacts the first annular surface portion, and extends from the first insertion portion to extend the second inner portion. A second fitting portion that is fitted into the second sleeve portion of the hole and contacts the second annular surface portion; and a second fitting portion that extends from the second fitting portion and comes to the third sleeve portion of the second inner hole. And an upper block that extends further into the fourth sleeve portion than the third insertion portion so that the second surface faces the first surface at a predetermined interval. It is good also as composition which has.

  According to this configuration, the upper mold has an effect of effectively controlling the thickness of the glass lens by sliding in the upper guide mold and being restrained to a predetermined height position.

  Further, the inner peripheral surface of the upper guide type second annular wall includes a first annular portion defining a third sleeve portion of the second inner hole, and a fourth sleeve portion of the second inner hole. The frustoconical annular surface may be provided between the first annular portion and the second annular portion.

  According to this structure, it has the same effect as the said structure.

  Furthermore, in the molding die of the present invention, the protective film is preferably formed on the inner peripheral surface of the second annular wall of the upper guide mold, preferably with a material having a low coefficient of friction and excellent wear resistance and high temperature oxidation resistance. You may make it the structure covered so that it may reach 1 annular part, a truncated cone ring surface, and a 2nd annular part.

  According to this configuration, the glass lens to be molded can be prevented from biting into the upper guide mold, and the glass lens can be easily taken out from the guide mold.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  6A and 6B, reference numeral 100 denotes a molding die for molding the glass lens 80 by heating and pressurizing (pressing) the set lens glass material 70. The upper mold 4 and the lower mold 3 are formed as upper guide molds. 2. Insert into the lower guide mold 1, for example, the lower mold 3 together with the lower guide mold 1 is fixed and the upper mold 4 is moved together with the upper guide mold 2 and the upper guide mold 2 is inserted into the lower guide mold 1 downward. It is the structure which slides.

  The lower guide mold 1 has a substantially cylindrical shape, and a first annular wall 11 defines a first inner hole 12. Further, the first inner hole 12 is formed into an upper large-diameter portion 121 and a lower small-diameter portion 122. For example, the first inner hole 12 is reduced in diameter so that the upper guide mold 2 is inserted and restrained to a predetermined depth. A protruding ring portion 113 having a contact surface 111 is formed.

  The upper guide mold 2 has a substantially cylindrical shape, and the lower end is inserted into the inner hole 12 from the upper end of the lower guide mold 1 so that the upper guide mold 2 can move up and down by a predetermined stroke. And the 2nd annular wall 21 defines the 2nd inner hole 22, and the 2nd annular wall 21 is the 2nd contact surface formed in the lower end part corresponding to the 1st contact surface 111 211 and a reference portion 226 having a funnel-shaped truncated cone ring surface 2111 that protrudes from the inner peripheral surface 212 on the second inner hole 22 side and widens. The second annular wall 21 of the upper guide mold 2 is further formed into an upper large diameter portion 213 and a small diameter portion 214 that can be inserted into the large diameter portion 121 of the lower first inner hole 12. In this example, the second contact surface 211 is provided on the lower end surface of the second annular wall 21 on the small diameter portion 214 side.

  In this example, the inner diameter of the second inner hole 22 of the upper guide mold 2 is reduced from the upper first sleeve portion 221 into which the upper mold 4 is inserted and the inner peripheral surface 212 of the annular wall 21. The second sleeve portion 222 is interposed between the first sleeve portion 221 and the second sleeve portion 222 via the first annular surface portion 223, and the second annular portion 225 is interposed between the second sleeve portion 222 and the second sleeve portion 222. A third sleeve defined by a first annular portion 2112 protruding from the inner peripheral surface 212 of the annular wall 21 and continuous with the upper peripheral edge 2261 which is smaller than the hole diameter of the second sleeve portion 222 and has the smallest hole diameter of the reference portion 226. The second contact surface 211 is defined by the second annular portion 2113 of the inner peripheral surface 212 of the second annular wall 21 via the frustoconical annular surface 2111 between the portion 224 and the third sleeve portion 224. The reference part 226 rises up to a predetermined height from the ring. Pore size and the fourth sleeve portion 227 continuous with the largest lower peripheral edge 2262 is formed. The circular truncated cone surface 2111 of the reference portion 226 is provided between the first annular portion 2112 and the second annular portion 2113 as illustrated.

  The lower die 3 has a configuration in which a first surface 33 serving as a lower surface of the molding cavity is formed at the upper end, and the lower die 3 is slidably inserted into the first inner hole 12 of the lower guide die 1. In this example, the size of the lower die 3 is a size that is fitted into the small diameter portion of the first inner hole of the guide type and slightly protrudes into the large diameter portion. The lower block 31 on the insertion side is inserted and inserted into the small diameter portion 122 of the first inner hole 12 of the lower guide mold 1 and rises to slightly protrude into the large diameter section 121, while the lower and upper guide molds 1. When the two first and second contact surfaces 111 and 211 come into contact with each other, the first surface 33 is configured to be within the fourth sleeve portion 227 of the second inner hole 22 of the upper guide mold 2. The The lower block 31 has a flange portion 32 protruding from the lower portion of the lower block 31 so that the lower block 31 stops when the predetermined height is inserted into the lower guide mold 1, and the protruding edge 322 is the lower end surface of the first annular wall 11. 112 is contacted.

  The upper die 4 is inserted into the second inner hole 22 of the upper guide die 2 and is moved close to the lower die 3 from above the lower die 3 to a predetermined distance (lens thickness) (see FIG. 9). The second surface 45 is formed at the lower end portion to be the upper surface of the molding cavity. In this example, the upper die 4 is further fitted with a first fitting portion 41 fitted into the first sleeve portion 221 of the second inner hole 22 of the upper guide die 2 and in contact with the first annular surface portion 223; From the second insertion portion 42, a second insertion portion 42 that is continuously inserted into the second sleeve portion 222 of the second inner hole 22 and contacts the second annular surface portion 225. Further, the third insertion portion 43 that continues to the third sleeve portion 224 of the second inner hole 22, and the second surface 45 that protrudes from the third insertion portion 43 faces the first surface 33. Thus, the upper block 44 is formed so as to reach the inside of the fourth sleeve portion 227.

  In this example, the second annular wall 21 of the upper guide mold 2 is used in order to reduce the biting of the glass lens to be molded to the upper guide mold 2 and to easily remove the glass lens 80 from the mold. The protective film 23 is formed on the inner peripheral surface 212 of the first annular portion 2112, the truncated cone annular surface 2111, and the second annular member, preferably by a material having a low friction coefficient and excellent wear resistance and high temperature oxidation resistance. It is covered so as to come to the part 2113.

  Next, the operation of the molding die configured as described above will be described.

  As shown in FIG. 6B, on the first surface 33 of the lower mold 3, a lens glass material 70 sized to be heated and filled in a molding cavity described later is placed and inserted into the lower guide mold 1. Then, the upper die 4 is inserted into the upper guide die 2, and the small diameter portion 214 of the upper guide die 2 is inserted into the large diameter portion 121 of the first inner hole 12 of the lower guide die 1 as shown in FIG. The upper mold 4 is brought into contact with the lens glass material 70 set on the surface 33 of the lower mold 3 in the first inner hole 12 together with the upper guide mold 2, and pressed against the lens glass material 70. It is lowered so as to stop at the position (I in FIG. 8) which is located by the lens thickness from the surface 33. As shown in FIGS. 8 and 9, the upper guide mold 2 has a contact surface 211 of the upper guide mold 2 and a contact surface 111 of the small diameter portion 122 of the lower guide mold 1 so as to regulate the effective thickness of the glass lens 80 to be molded. Stopped by contact. At this time, in the upper guide mold 2, the first surface 33 of the upper mold 3 reaches the fourth sleeve portion 227 of the second inner hole 22, and the lower block 31 of the lower mold 3 is the upper guide mold 2. The second annular portion 2113 is lowered so as to reach the inside. At this time, the upper peripheral edge of the lens glass material 70 on the lower die 3 is pressed against the truncated cone ring surface 2111 of the reference portion 226 in the second inner hole 22 of the upper guide die 2. As shown in FIG. 9, while the mold 100 is heated as a whole, the upper block 44 of the upper mold 4 further includes the third sleeve portion 224 in the second inner hole 22 of the upper guide die 2, that is, the first annular portion. The glass lens 80 is pressed downward so as to have an effective thickness. At this time, a sealed cavity 50 for molding a glass lens is defined by the first surface 33, the second surface 45, and the truncated cone ring surface 2111. The lens glass material 70 is pressurized and can be formed into a glass lens 80 having a predetermined shape in the cavity 50. As described above, since the entire periphery of the glass lens 80 can be sealed and molded, the shrinkage distortion of the glass lens whose thickness is biased in the subsequent cooling process can be suppressed, and the deformation of the lens can be suppressed. Can be effectively suppressed.

  Even if the lens glass material 70 is set on the surface 33 of the lower mold 3 so as to be shifted from the central axis of the lower mold 3 as shown in FIG. When the upper die 4 is pressurized as shown in FIG. 11, only a part of the upper peripheral edge of the lens glass material 70 first hits the truncated cone ring surface 2111 of the reference portion 226 as shown in FIG. Then, the lens glass material 70 is placed at a substantially central position of the surface 33 of the lower mold 3, that is, until the entire upper periphery of the lens glass material 70 hits the truncated cone ring surface 2111 (FIG. 12). Then, in the same manner as the above operation, the entire cavity 50 can be finally filled as shown in FIG. Thus, even if the lens glass material 70 is not set in the middle on the surface 33, it can be automatically adjusted so that it is in the middle position.

  According to the molding die of the present invention, when the lens glass material set in the die is heated and pressed, the molding cavity defined by the first and second surfaces and the circular truncated cone is filled. A glass lens is molded. For this reason, glass lenses having different thicknesses at the central portion and the peripheral portion are regulated and molded in a cavity defined by the first and second surfaces and the frustoconical annular surface while being cooled. The shrinkage bias due to shrinkage can be reduced, and the strain due to shrinkage can be made uniform.

  Furthermore, according to the molding die of the present invention, it is possible to automatically adjust the lens glass material so that it is in the middle position without setting the lens glass material in the middle of the cavity. I can make it well. Therefore, productivity can be improved.

The sectional side view which shows schematically the structure of the shaping | molding die of the conventional glass lens. The figure which shows the state at the time of the completion of glass lens shaping | molding of FIG. FIG. 3 is a side sectional view showing the shape of the molded glass lens of FIG. 2. The state when the lens glass material in a mold of FIG. 1 is set deviating from the central axis is shown. The state at the time of completion | finish of shaping | molding of a glass lens is shown with the state of FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view schematically showing a configuration of a glass lens molding die and a lens glass material according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view schematically showing a configuration of a glass lens molding die and a lens glass material according to an embodiment of the present invention. The state 1 when the metal mold | die of FIG. 6 shape | molds a glass lens is shown. The state 2 when the glass lens by the same mold is shape | molded is shown. The state 3 when the glass lens by the same metal mold | die is shown is shown. FIG. 7 shows a state when the lens glass material in the mold of FIG. 6 is set deviating from the central axis. State 1 when a glass lens is molded from the state of FIG. FIG. 11 shows a state 2 when a glass lens is molded.

Explanation of symbols

1. . . Lower guide type 100. . . 10. Molding tool . . First annular wall 111. . . First contact surface 112. . . Lower end surface 113. . . Projection ring 12. . . First inner hole 121. . . Large diameter portion 122. . . Small diameter part 2. . . Upper guide type 21. . . Second annular wall 211. . . Second contact surface 2111. . . Frustum ring surface 2112. . . First annular portion 2113. . . Second annular portion 212. . . Inner peripheral surface 213. . . Large diameter part 214. . . Small diameter portion 22. . . Second inner hole 221. . . First sleeve portion 222. . . Second sleeve portion 223. . . First annular surface portion 224. . . Third sleeve portion 225. . . Second annular surface portion 226. . . Reference section 2262. . . Lower peripheral edge 227. . . Fourth sleeve portion 23. . . 2. Protective film . . Lower mold 31. . . Lower block 32. . . Collar portion 322. . . Protruding edge 33. . . First surface4. . . Upper mold 41. . . First insertion portion 42. . . Second insertion part 43. . . Third insertion part 44. . . Upper block 45. . . Second surface 50. . . Cavity 70. . . Lens glass material 80. . . Glass lens

Claims (9)

A molding die that molds a glass lens by heating and pressurizing the set lens glass material.
A cylindrical lower guide mold having a first annular wall defining a first inner hole, and a first contact surface formed on the first annular wall;
A second annular wall defining a second inner hole so as to be movable relative to the upper end of the lower guide mold, the second annular wall corresponding to the first contact surface; A cylindrical shape having a second contact surface to be abutted and a reference portion having a truncated cone ring surface extending from the inner peripheral surface on the second inner hole side to the second contact surface The upper guide type,
A lower mold that is inserted into the first inner hole of the lower guide mold and has a first surface formed on the glass material pressure end;
The upper guide mold is fitted into the second inner hole so as to be slidable between the lower mold and a position close to the lower mold from above, and a second surface is formed at the opposite glass material pressure end. Consisting of the upper mold formed,
By bringing the first contact surface of the lower guide mold and the second contact surface of the upper guide mold into contact with each other, the upper mold is moved to the close position in the upper guide mold. A glass lens configured to define a cavity for molding a glass lens by the first surface of the mold, the second surface of the upper mold, and the circular truncated cone surface of the reference portion Molding mold. The first inner hole of the lower guide type has a large diameter portion on the upper guide die side and a small diameter portion on the side facing the upper guide die,
The glass lens molding die according to claim 1, wherein the first contact surface is provided between the large diameter portion and the small diameter portion. The upper guide type second annular wall is formed corresponding to a large diameter portion on the opposite side of the lower guide type and a large diameter portion of the first inner hole on the lower guide type side. Having a small diameter portion,
The glass lens molding die according to claim 2, wherein the second contact surface is formed at a lower end of the second annular wall near the small-diameter portion. The second inner hole of the upper guide type is
A first sleeve portion on the side where the upper mold is inserted;
A second sleeve portion that is smaller than the hole diameter of the first sleeve portion with a first annular surface portion interposed between the first sleeve portion and the first sleeve portion;
A third sleeve portion that is continuous with the periphery of the upper end portion having the smallest hole diameter of the reference portion smaller than the hole diameter of the second sleeve portion with a second annular surface portion interposed between the second sleeve portion and the second sleeve portion;
The standard part is interposed between the third sleeve part and the peripheral edge of the lower end part where the hole diameter of the standard part is maximum so as to rise from the second contact surface to a predetermined height in an annular shape. The glass lens molding die according to claim 3, wherein the fourth sleeve portion is formed. The lower mold is
When the first and second contact surfaces of the lower and upper guide types come into contact with each other, they extend into the fourth sleeve portion of the second inner hole of the upper guide type, and the second surface is the fourth surface. A lower block formed so as to be in the sleeve portion of
The glass lens molding die according to claim 4, wherein a flange portion protruding from the lower end portion of the lower block and having a protruding edge that contacts the lower end surface of the first annular wall is formed. The upper mold is
A first insertion portion that is inserted into the first sleeve portion of the second inner hole and contacts the first annular surface portion;
A second fitting portion that extends from the first fitting portion, is fitted into the second sleeve portion of the second inner hole, and contacts the second annular surface portion;
A third insertion portion extending from the second insertion portion and coming to the third sleeve portion of the second inner hole;
An upper block that extends further into the fourth sleeve portion than the third fitting portion is formed so that the second surface faces the first surface with a predetermined interval. Item 6. A mold for molding a glass lens according to Item 5. An inner peripheral surface of the upper guide-type second annular wall includes a first annular portion defining a third sleeve portion of the second inner hole, and a fourth sleeve of the second inner hole. A second annular portion defining a portion,
The glass lens mold according to claim 4, wherein the frustoconical annular surface is provided between the first annular portion and the second annular portion.   A protective film is coated on an inner peripheral surface of the upper guide type second annular wall so as to reach the first annular portion, the truncated cone annular surface, and the second annular portion. Item 8. A glass lens mold according to Item 7. The glass lens mold according to claim 8, wherein the protective film is a material having a low friction coefficient and excellent wear resistance and high-temperature oxidation resistance.

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