JP7066533B2 - Glass lens molding mold - Google Patents

Description

The present invention relates to a molding die for molding a glass lens.

In the manufacture of glass lenses, a method of shaping the glass as a material into a rough shape and then finishing it by grinding or polishing has been conventionally used. In recent years, a method of manufacturing a glass lens without grinding or polishing by pressing and molding a glass in a heated and softened state with a molding die (hereinafter referred to as a molding die) has also been put into practical use. (For example, Patent Document 1). By molding using such a molding mold, it has become possible to mass-produce not only spherical lenses but also aspherical lenses having complicated shapes and the like at low cost.

In press molding, the surface shape (molding surface) of the molding die is transferred to the object to be molded, so that the accuracy of the molding die is extremely demanded. For example, the molding die is required to have high rigidity and heat resistance so as not to cause deformation due to a load acting at the time of pressing or heating. It is also necessary for the molding die to have an appropriate coefficient of thermal expansion with respect to the object to be molded in order to prevent the object to be molded from sticking to the mold and cracking of the object to be molded.

Molds made of metal, ceramics, or the like are widely used to satisfy the above conditions. However, it is costly and time-consuming to individually manufacture such a molding die by cutting or the like while suppressing variations in accuracy. In particular, in the case of mass production of glass lenses for optical instruments, many molding dies are required. As a countermeasure, a technique using a glass molding die has been proposed (for example, Patent Documents 2 and 3).

Specifically, a master mold (master mold) having a reference molding surface is prepared, and the glass material for the molding mold softened by heating is pressed and molded by the master mold to transfer the molding surface of the master mold. A glass molding die (hereinafter referred to as a glass molding die) can be obtained. The glass molding mold has the advantages that mass production is easy once a high-precision master mold is manufactured, and the degree of freedom in shape setting is high.

Japanese Unexamined Patent Publication No. 6-127956 Japanese Patent No. 2616964 Japanese Unexamined Patent Publication No. 2-102136

As a problem of glass molding dies, it may be difficult to secure heat resistance when molding at high temperature is repeated and impact resistance against external impact compared to metal or ceramic molding dies, so it is durable. Improvement of sex was desired. As a countermeasure, in Patent Document 3, a bonded body made of a metal or ceramics having a thermal expansion coefficient (linear expansion coefficient) substantially equal to that of the material glass constituting the glass molding mold is joined to the glass molding mold and integrated. ing.

However, in the configuration of joining a bonded body made of another material to a glass molding die, the thermal expansion coefficient of the bonded body is required to be the same as that of the glass molding die, so that the degree of freedom in material selection is low. .. In addition, it is difficult to completely match the coefficient of thermal expansion of the glass molding mold and the joint body, so if heating is performed in a state where they are integrated in the joint, stress will be applied to each other's joints due to the difference in the coefficient of thermal expansion. That is inevitable. Furthermore, when integrating the glass mold and the joint, the central axis of the glass mold (the optical axis of the lens molded by the glass mold) and the central axis of the joint match with high accuracy. It is necessary to make it difficult to manufacture, and it takes time and cost.

Patent Document 1 describes a technique for forming a molding die by combining a cavity die having a cavity surface for molding a glass lens and a mold made of a material having a coefficient of linear expansion smaller than that of the cavity die. The mold is formed with a hole having a conical trapezoidal cross section whose diameter gradually increases toward the tip end side (the side having the molding surface) of the cavity die, and this hole is fitted to the cavity die. The inner peripheral surface of the hole of the mold and the peripheral surface of the cavity die are tapered surfaces that polymerize in a state where they can be slidably contacted with each other. Can be prevented. However, since the cavity die and the mold are not joined, the cavity die may fall off from the mold with the molding mold separated, which is not practical.

The present invention has been made in view of such problems, and an object of the present invention is to provide a glass lens molding mold having excellent productivity, durability, high accuracy, and practicality.

INDUSTRIAL APPLICABILITY In a glass lens molding mold that press-molds a glass lens, the present invention has a body mold having an internal space extending in the mold moving direction and a body mold that is movably inserted into the internal space of the body mold in the mold moving direction and is one end in the mold moving direction. Molded to form one lens surface of a glass lens, consisting of a metal or ceramic mold base material having a contact portion on the base material side and glass having a glass transition temperature higher than that of the glass to be molded, which is the material of the glass lens. A glass molding mold having a surface and a mold-side contact portion that faces the opposite side of the molding surface in the mold moving direction and can be brought into contact with the base material-side contact portion, and faces the molding surface of the glass molding mold. It has a second molding surface that forms the other lens surface of the glass lens, and includes a glass molding mold and an opposed mold that can move relative to the mold moving direction. At least one of the base material side contact portion and the mold side contact portion has a centering surface that is a part of a conical surface centered on an axis extending in the mold moving direction, and the base material side contact portion and the mold side. The contact of the abutting portion holds the glass molding mold in a fixed position with respect to the mold base material in the mold moving direction and the direction perpendicular to the mold moving direction. Further, the glass molding mold has a regulated surface around the molding surface, and the inside of the body mold has a regulating surface facing the regulated surface in the direction of mold movement, so that the regulated surface comes into contact with the regulated surface. This limits the amount of movement of the glass molding mold with respect to the body mold in the direction of separating the mold side contact portion from the base material side contact portion.

It is preferable that the regulated surface and the regulated surface each consist of a part of a conical surface whose central axis is common to the centering surface. This makes it possible to improve the stability of the glass molding mold with respect to the mold base material in a state where the regulated surface and the regulated surface are in contact with each other.

The regulated surface and the regulated surface are set so as to be separated from each other in a state where the glass lens is press-molded between the molded surface and the second molded surface. As a result, the regulated surface and the regulated surface do not affect the position accuracy of the glass molding die and the facing die during press molding.

The facing mold can be composed of a second mold base material made of metal or ceramics and a second glass molding mold made of glass having a glass transition temperature higher than that of the glass to be molded, which is the material of the glass lens. The second mold base material is movably inserted into the internal space of the body mold in the mold moving direction, and has a second base material side contact portion at one end in the mold moving direction. The second glass molding die is a second mold that faces the second molding surface in the direction opposite to the second molding surface in the mold moving direction and can be brought into contact with and separated from the second base material side contact portion. It has a side contact portion. At least one of the second base material side contact portion and the second mold side contact portion has a centering surface that is a part of the conical surface centered on the axis, and is on the second base material side. The contact between the abutting portion and the abutting portion on the second mold side holds the second glass molding mold in a fixed position with respect to the second mold base material in the mold moving direction and the direction perpendicular to the mold moving direction. ..

According to the above-mentioned glass lens molding mold of the present invention, the portion having the molding surface for molding the lens surface of the glass lens is a glass molding mold, and the metal or ceramic mold base material that abuts on the glass molding mold is used. It is supported so that it can be moved within the body. Therefore, the glass molding mold can be mass-produced at low cost, and the durability can be improved by the mold base material having excellent heat resistance and impact resistance. Further, since the glass molding mold and the mold base material are not joined and fixed, the relative positions are determined by the contact of the contact portions with each other, so that the load due to the difference in the thermal expansion coefficient between the glass molding mold and the mold base material Highly accurate mold accuracy can be obtained, and the degree of freedom in selecting materials for glass molding molds and mold base materials is high. In addition, since it has a regulated surface and a regulated surface that limit the amount of movement of the glass molding mold in the direction away from the mold base material, it can be handled and operated even though the glass molding mold and the mold base material are not fixed. It is easy and excellent practicality can be obtained.

It is sectional drawing which shows the preparation state of the pressure molding in the glass lens molding die of this embodiment. It is sectional drawing which shows the press molding completion state in a glass lens molding die. It is sectional drawing which shows the process of taking out the glass lens after molding by separating the upper mold unit and the lower mold unit after the press molding is completed.

In the glass lens molding mold 10 of the present embodiment, the upper mold unit 11 and the lower mold unit (opposing mold) 12 are relatively moved along the reference axis (axis) X, and the glass preform which is the glass to be molded before molding is formed. 13 (FIG. 1) is pressed to form a glass lens 14 (FIGS. 2 and 3).

As shown in FIG. 3, the glass lens 14 is an aspherical lens in which both lens surfaces 14a and 14b are aspherical, one lens surface 14a is concave and the other lens surface 14b is convex. Further, an annular edge portion 14c is formed on the peripheral edge of the glass lens 14.

The glass lens molding die 10 includes a body die 20 that guides the upper die unit 11 and the lower die unit 12. The upper mold unit 11 includes an upper mold base material (mold base material) 30 and an upper mold (glass molding mold) 40. The lower mold unit 12 includes a lower mold base material (second mold base material) 50 and a lower mold (second glass molding mold) 60. The upper mold 40 and the lower mold 60 are made of glass satisfying the conditions described later, and the body mold 20, the upper mold base material 30 and the lower mold base material 50 are made of a non-glass material, specifically, silicon carbide ( It is made of ceramics such as SiC) and silicon nitride (Si ₃ N ₄ ), or metals such as cemented carbide.

The reference axis X coincides with the optical axis of the glass lens 14 molded by the glass lens molding die 10. The upper mold 40 and the lower mold 60 are pressed and molded in a state of being positioned (centered) via the upper mold base material 30 and the lower mold base material 50 so that their respective central axes coincide with the reference axis X. The details of this positioning will be described later. In the following description, the direction along the reference axis X is the vertical direction (mold movement direction), and the direction perpendicular to the reference axis X is the radial direction.

The body type 20 is a tubular body that surrounds the reference axis X, and has an internal space S (FIG. 3) penetrating in the vertical direction inside. Inside the body mold 20, an upper inner surface 21 is formed in a predetermined range in the vertical direction from the upper end side, and a lower inner surface 22 is formed in a predetermined range in the vertical direction from the lower end side. The upper inner surface 21 and the lower inner surface 22 are each a cylindrical surface (inner surface of the cylinder) centered on the reference axis X, and the inner diameter of the upper inner surface 21 is larger than the inner diameter of the lower inner surface 22.

Inside the body mold 20, an upper mold restricting surface (regulating surface) 23 is provided between the upper inner surface 21 and the lower inner surface 22. More specifically, the body mold 20 is provided with a protruding portion 24 projecting in the inner diameter direction in a continuous annular shape in the circumferential direction, and an upper mold restricting surface 23 is formed on the protruding portion 24. The upper type regulating surface 23 is a part of a conical surface (inner surface of the cone) centered on the reference axis X, and its diameter decreases as it goes downward. That is, the upper die regulating surface 23 has a tapered shape in which the amount of protrusion toward the inner diameter side increases as the upper inner surface 21 moves downward.

A through hole 25 that penetrates the body mold 20 in the radial direction is formed in the lower end portion (upper portion of the protruding portion 24) of the upper inner surface 21. Further, a through hole 26 that penetrates the body mold 20 in the radial direction is formed in the upper end portion (lower portion of the protruding portion 24) of the lower inner surface 22.

The upper mold base material 30 is inserted into the body mold 20 so as to be movable in the vertical direction. On the outer surface of the upper base material 30, a cylindrical slide guide surface 31 having an outer diameter size corresponding to the inner diameter size of the upper inner surface 21 is formed. Due to the contact between the upper inner surface 21 and the slide guide surface 31, the central axes of the body mold 20 and the upper mold base material 30 coincide with each other. The central axes of the body mold 20 and the upper mold base material 30 coincide with the reference axis X. Further, the slide guide surface 31 is slidably supported in the vertical direction with respect to the upper inner surface 21 without causing tilting or rattling. A rotation restricting structure may be provided between the body mold 20 and the upper mold base material 30 so as to prevent the relative rotation of the body mold 20 and the upper mold base material 30 in the circumferential direction about the reference axis X. ..

The glass lens molding mold 10 includes a driving means 70 for moving the upper mold base material 30 in the vertical direction with respect to the body mold 20, and a driving means 71 for moving the lower mold base material 50 in the vertical direction with respect to the body mold 20. Has.

At the lower end (one end in the mold moving direction) of the upper mold base material 30, a centering surface (base material side contact portion) 32 and a bottom surface 33 are formed. The centering surface 32 is a part of a conical surface (inner surface of the cone) centered on the reference axis X, and its diameter decreases as it advances upward. The bottom surface 33 is a flat surface that closes the upper end of the alignment surface 32. The lower end of the upper base material 30 is a mortar-shaped recess due to the tapered centering surface 32.

The upper base material 30 is formed with a suction hole 34 that penetrates in the vertical direction. The center line of the suction hole 34 substantially coincides with the reference axis X. The lower end of the suction hole 34 opens in the center of the bottom surface 33. The upper end of the suction hole 34 is opened to the upper end surface of the upper base material 30 and is connected to the suction pipe 16 extending from the suction source 15.

Vacuum gas replacement is performed when molding the glass lens molding die 10 in the completed state (FIG. 1). At that time, the suction source 15 is driven to bleed air between the bottom surface 33 of the upper mold base material 30 and the upper surface 44 of the upper mold 40 through the suction pipe 16 and the suction hole 34. Further, using the suction structure from the suction source 15 to the suction hole 34, the upper mold 40 is sucked and held in the recess (the region surrounded by the centering surface 32 and the bottom surface 33) at the lower end of the upper mold base material 30. Force can be applied.

The lower base material 50 has a large diameter portion 51 and a small diameter portion 52 having a smaller diameter than the large diameter portion 51 and projecting upward from the large diameter portion 51. The large diameter portion 51 has substantially the same outer diameter size as the body type 20. On the outer surface of the small diameter portion 52, a cylindrical slide guide surface 53 having an outer diameter size corresponding to the inner diameter size of the lower inner surface 22 of the body mold 20 is formed.

The lower mold base material 50 can insert and remove the small diameter portion 52 from below with respect to the body mold 20. In the inserted state of the small diameter portion 52 with respect to the body mold 20, the concentricity between the body mold 20 and the lower mold base material 50 is maintained by the contact between the lower inner surface 22 and the slide guide surface 53 (center of the lower mold base material 50). The axis coincides with the reference axis X). Further, the slide guide surface 53 is slidably supported in the vertical direction with respect to the lower inner surface 22 without causing inclination or rattling. A rotation restricting structure may be provided between the body mold 20 and the lower mold base material 50 so as to prevent the relative rotation of the body mold 20 and the lower mold base material 50 in the circumferential direction about the reference axis X. ..

When the lower end of the body die 20 abuts on the large diameter portion 51, the maximum insertion amount of the small diameter portion 52 with respect to the body die 20 is determined (see FIGS. 1 and 2). In this maximum insertion state, the upper end of the small diameter portion 52 is located below the through hole 26. That is, the through hole 26 and the through hole 25 above it are not blocked by the lower base material 50.

At the upper end (one end in the mold moving direction) of the lower mold base material 50, a centering surface (second base material side contact portion) 54, a recess 55, and an inner peripheral surface 56 are formed. The centering surface 54 is a part of a conical surface (inner surface of the cone) centered on the reference axis X, and its diameter decreases as it goes downward. The recess 55 is recessed further downward from the center of the alignment surface 54. The inner peripheral surface 56 is a cylindrical surface (inner surface of the cylinder) centered on the reference axis X, and projects upward from the upper end edge of the alignment surface 54. The upper end of the lower base material 50 is a mortar-shaped recess including a tapered centering surface 54 on the inner surface.

The lower base material 50 is formed with a suction hole 57 that penetrates in the vertical direction. The center line of the suction hole 57 substantially coincides with the reference axis X. The upper end of the suction hole 57 opens in the center of the bottom surface of the recess 55, and the lower end of the suction hole 57 is connected to the suction pipe 18 extending from the suction source 17.

At the time of vacuum gas replacement in the completed state (FIG. 1) of the glass lens molding mold 10, the suction source 17 is driven, and the recess 55 and the lower mold 60 of the lower mold base material 50 are driven through the suction pipe 18 and the suction hole 57. Bleed the air between and. Further, using the suction structure from the suction source 17 to the suction hole 57, the lower mold 60 is attracted to the upper end portion of the small diameter portion 52 (the concave portion surrounded by the centering surface 54, the recess 55 and the inner peripheral surface 56). The suction force to hold can be applied.

The upper mold 40 and the lower mold 60 have a molding surface 41 and a molding surface (second molding surface) 61 on the sides facing each other. In the upper mold 40, the side having the molding surface 41 is the front surface side, and the opposite side is the back surface side. Similarly, in the lower mold 60, the side having the molding surface 61 is the front surface side, and the opposite side is the back surface side. The molding surface 41 and the molding surface 61 are aspherical surfaces having a shape corresponding to one lens surface 14a and the other lens surface 14b of the glass lens 14, respectively. The molded surface 61 has a cylindrical surface portion corresponding to the edge portion 14c on the peripheral edge of the concave surface portion corresponding to the convex surface shape of the lens surface 14b. The present invention can also be applied to molding a glass lens having a form other than the illustrated glass lens 14, and the shapes of the molding surface 41 and the molding surface 61 are appropriately set according to the lens shape.

A coating layer (not shown) may be formed on the molding surface 41 or the molding surface 61. The coating layer is made of a carbon film or the like, and has an effect of suppressing fusion of the glass to be molded constituting the glass lens 14. The coating layer may have a single-layer structure, or a multi-layer structure coating layer having a different composition may be provided. Alternatively, a configuration in which the molding surface 41 or the molding surface 61 is exposed without the coating layer can be selected.

On the surface side of the upper mold 40, a regulated surface 42 is formed around the molding surface 41. The regulated surface 42 is a part of a conical surface (outer surface of the cone) centered on the reference axis X, and its diameter decreases as it goes downward. An annular step portion 43 centered on the reference axis X is formed between the molding surface 41 and the regulated surface 42.

On the back surface side of the upper mold 40, an upper surface 44 located on the back side of the molding surface 41 and a centering surface (mold side contact portion) 45 located on the back side of the regulated surface 42 are formed. The centering surface 45 is a part of a conical surface (outer surface of the cone) centered on the reference axis X, and its diameter decreases as it goes upward. The alignment surface 45 is a part of the same conical surface (equal apex angle) as the alignment surface 32 of the upper base material 30.

Further, the upper mold 40 is formed with a cylindrical outer peripheral surface 46 between the regulated surface 42 and the centering surface 45. The outer diameter size of the outer peripheral surface 46 is smaller than the inner diameter size of the upper inner surface 21 of the body mold 20, and the outer peripheral surface 46 is radially separated from the upper inner surface 21 in the positioning state of the upper mold 40 described later.

The position of the upper mold 40 with respect to the upper mold base material 30 is determined by bringing the alignment surface 45 into contact with the alignment surface 32. The alignment surface 32 and the alignment surface 45 are conical tapered surfaces that can be surface-contacted with each other, and abut each other in a state where their central axes (straight lines extending in the height direction of the cone and passing through the apex) coincide with each other. By this contact, the position of the upper mold 40 in the vertical direction with respect to the upper mold base material 30 is determined, and the position of the upper mold 40 in the radial direction about the reference axis X is also determined. Then, when the upper mold 40 is positioned by the contact between the alignment surface 32 and the alignment surface 45 with the upper mold base material 30 housed in the body mold 20, the upper mold base material 30 and the upper mold 40 are respectively positioned. The central axis of is aligned with the reference axis X. That is, the upper mold 40 is properly aligned with the body mold 20 and the upper mold base material 30, and the reference axis X passes through the center of the molding surface 41.

In the positioning state of the upper die 40 in which the alignment surface 32 and the alignment surface 45 are in contact with each other, there is a vertical gap between the bottom surface 33 and the top surface 44. Further, in the positioning state, there is a radial gap between the upper inner surface 21 and the outer peripheral surface 46. As a result, only the alignment surface 32 is directly in contact with the upper die 40 for positioning, and the portion other than the alignment surface 32 does not interfere with the positioning of the upper die 40.

As described above, the upper mold unit 11 is composed of the upper mold base material 30 made of non-glass (made of metal or ceramics) and the upper mold 40 made of glass. The upper mold 40 is a part of the upper mold unit 11 including a molding surface 41 for molding the glass lens 14, and the upper mold base material 30 which is the other part has heat resistance and impact resistance as compared with glass. It is made of metal or ceramics with excellent properties. In particular, since the upper mold base material 30 is a portion that slides with respect to the body mold 20 and receives a pressing force from the outside during press molding described later, it is formed of a metal or ceramics having excellent mechanical strength. This is effective, and the use of the upper mold base material 30 contributes to ensuring the accuracy of the upper mold unit 11.

The upper mold 40 can be made into a small and simple shape specialized for the molding surface 41 and its surroundings, and is easy to manufacture. More specifically, the upper mold 40 surrounds the molded surface 41 and the upper surface 44 located on the front and back sides with a conical regulated surface 42, a centering surface 45, and a cylindrical outer peripheral surface 46, and is formed into a convex lens. It has a similar simple cross-sectional shape. Further, the wall thickness of the upper mold 40 from the molding surface 41 to the upper surface 44 is about a fraction of the size of the entire upper mold unit 11 in the vertical direction. Therefore, the amount of glass constituting the upper mold 40 can be reduced, and the cost can be suppressed when manufacturing the upper mold 40. Further, when the upper mold 40 is manufactured, the shrinkage of the glass due to cooling after molding is small, and it is easy to control the quality.

The upper mold base material 30 and the upper mold 40 are not fixed to each other by adhesion or the like, and are configured to position the upper mold 40 by contact between the alignment surface 32 and the alignment surface 45 which can be brought into contact with each other. Therefore, even if the coefficients of thermal expansion of the materials constituting the upper mold base material 30 and the upper mold 40 are different to some extent, excessive stress is unlikely to be applied to the boundary (contact) portion between the upper mold base material 30 and the upper mold 40. That is, the allowable range of the coefficient of thermal expansion of the materials constituting the upper mold base material 30 and the upper mold 40 is wider than that of the configuration in which the upper mold base material 30 and the upper mold 40 are relatively fixed, and the material can be selected. The degree of freedom is improved.

The upper mold 40 is located below the upper mold base material 30, and the centering surface 32 and the centering surface 45 are conical surfaces whose diameters increase as they go downward. Therefore, the upper mold base material 30 does not limit the movement of the upper mold 40 downward (in the direction in which the alignment surface 45 is separated from the alignment surface 32).

The upper mold restricting surface 23 provided on the body mold 20 limits the amount of movement of the upper mold 40 downward. That is, the upper mold 40 is prevented from falling off downward. The upper mold restricting surface 23 is provided at a position facing the regulated surface 42 of the upper mold 40 in the vertical direction, and when the upper mold 40 moves downward in the body mold 20, the regulated surface 42 is regulated by the upper mold. It abuts on the surface 23 (FIG. 3). The molding surface 41 and the stepped portion 43 of the upper mold 40 have a diameter that allows them to pass through the inside of the upper mold restricting surface 23, and can project downward from the protruding portion 24 (see FIGS. 2 and 3).

An annular protrusion 62 is formed on the surface side of the lower mold 60 so as to project upward from the peripheral edge of the molding surface 61. When the upper die 40 and the lower die 60 are brought close to each other in the vertical direction, the step portion 43 of the upper die 40 can enter the inside of the annular protrusion 62 (see FIG. 2).

A alignment surface (second mold side contact portion) 63 is formed on the back surface side of the lower mold 60. The centering surface 63 is a part of a conical surface (outer surface of the cone) centered on the reference axis X, and its diameter decreases as it goes downward. The alignment surface 63 is a part of the same conical surface (equal apex angle) as the alignment surface 54 of the lower base material 50.

The lower mold 60 further has an outer peripheral surface 64 protruding upward from the peripheral edge of the alignment surface 63. The outer peripheral surface 64 is a cylindrical surface centered on the reference axis X, and is continuous up to the position of the annular protrusion 62. The area between the centering surface 63 and the outer peripheral surface 64 has a curved surface shape that curves gently.

The position of the lower mold 60 with respect to the lower mold base material 50 is determined by bringing the alignment surface 63 into contact with the alignment surface 54. The alignment surface 54 and the alignment surface 63 are conical tapered surfaces that can be surface-contacted with each other, and abut each other in a state where their central axes (straight lines extending in the height direction of the cone and passing through the apex) coincide with each other. As a result, the position of the lower mold 60 in the vertical direction is determined with respect to the lower mold base material 50, and the position of the lower mold 60 in the radial direction about the reference axis X is also determined. Then, when the small diameter portion 52 of the lower mold base material 50 is inserted into the body mold 20 (FIGS. 1 and 2), the lower mold 60 is positioned by the contact between the alignment surface 54 and the alignment surface 63. The central axes of the lower mold base material 50 and the lower mold 60 coincide with the reference axis X. That is, the lower mold 60 is properly aligned with the body mold 20 and the lower mold base material 50, and the reference axis X passes through the center of the molding surface 61.

In the positioning state of the lower mold 60 in which the alignment surface 54 and the alignment surface 63 are in contact with each other, there is a radial gap between the inner peripheral surface 56 and the outer peripheral surface 64. As a result, only the alignment surface 54 is directly in contact with the lower mold 60 for positioning, and the portion other than the alignment surface 54 does not interfere with the positioning of the lower mold 60.

Similar to the upper mold unit 11, the lower mold unit 12 is composed of a lower mold base material 50 made of non-glass (made of metal or ceramics) and a lower mold 60 made of glass. The lower mold 60 is a part of the lower mold unit 12 including a molding surface 61 for molding the glass lens 14, and the lower mold base material 50, which is the other part, has heat resistance and impact resistance as compared with glass. It is made of metal or ceramics with excellent properties. In particular, since the lower mold base material 50 is a portion that slides with respect to the body mold 20 and receives a pressing force from the outside during press molding described later, it is formed of a metal or ceramics having excellent mechanical strength. This is effective, and the use of the lower mold base material 50 contributes to ensuring the accuracy of the lower mold unit 12.

The lower mold 60 can be made into a small and simple shape specialized for the molding surface 61 and its surroundings, and is easy to manufacture. More specifically, the lower mold 60 has a simple cross-sectional shape similar to a concave lens in which the molding surface 61 and the centering surface 45 are located on the front and back sides. Further, the wall thickness of the lower mold 60 in the vertical direction is about a fraction of the size of the entire lower mold unit 12 in the vertical direction. Therefore, the amount of glass constituting the lower mold 60 can be reduced, and the cost can be suppressed when manufacturing the lower mold 60. Further, when the lower mold 60 is manufactured, the shrinkage of the glass due to cooling after molding is small, and it is easy to control the quality.

The lower mold base material 50 and the lower mold 60 are not fixed to each other by adhesion or the like, and are configured to position the lower mold 60 by contact between the alignment surface 54 and the alignment surface 63 that can be brought into contact with each other. Therefore, even if the coefficients of thermal expansion of the materials constituting the lower mold base material 50 and the lower mold 60 are different to some extent, excessive stress is unlikely to be applied to the boundary (contact) portion between the lower mold base material 50 and the lower mold 60. That is, the allowable range of the coefficient of thermal expansion of the materials constituting the lower mold base 50 and the lower mold 60 is wider than that of the configuration in which the lower mold base material 50 and the lower mold 60 are relatively fixed, and the material can be selected. The degree of freedom is improved.

A heater (not shown) is provided on the outside of the body type 20. When the glass lens 14 is press-molded, the inside of the body mold 20 is heated by a heater to a molding temperature at which the glass preform 13 (glass to be molded) softens.

Although not shown, the upper mold 40 and the lower mold 60 are manufactured by pressure molding using a master mold (master mold). A master mold for manufacturing the upper mold 40 and the lower mold 60 is prepared separately. These master molds are made of metal, ceramics, or the like, and have a molding surface 41 and a reference molding surface that is the basis of the molding surface 61. By pressing a glass material for molding that has been softened by heating (glass that satisfies each condition described later and is different from the glass to be formed for the glass lens 14) on the reference molding surface of each master mold. The upper mold 40 and the lower mold 60 to which the reference molding surface is transferred as the molding surface 41 or the molding surface 61 are molded.

The upper mold 40 and the lower mold 60 are each made of a glass material satisfying the following conditions.
(1) Young's modulus is 85 GPa or more.
(2) The glass transition temperature (Tg) is 650 ° C or higher.
(3) The average coefficient of thermal expansion (α100-300) of 100 ° C to 300 ° C is 30 × ^10-7 / ° C to 80 × ^10-7 / ° C.

The condition (1) is related to the rigidity of the upper die 40 and the lower die 60. If the upper mold 40 and the lower mold 60 are bent during press molding, the shapes of the molding surfaces 41 and 61 are not maintained, which affects the molding accuracy of the glass lens 14. When the Young's modulus is 85 GPa or more, even if a predetermined pressing force is applied during molding of the glass lens 14, it is possible to prevent the upper mold 40 and the lower mold 60 from bending due to the load, and the accuracy of the molded surfaces 41 and 61 is not impaired. Can be molded.

The condition (2) is related to the influence of heating during molding on the upper mold 40 and the lower mold 60. The glass with a higher glass transition point than the glass to be molded, which is the material of the glass lens 14, is used as the material for the upper mold 40 and the lower mold 60, and is lower than the glass transition point of the glass for the upper mold 40 and the lower mold 60. By setting the temperature to the molding temperature, it is possible to soften only the glass to be molded without softening the upper mold 40 and the lower mold 60.

More specifically, when the glass transition temperature of the glass which is the material of the upper mold 40 and the lower mold 60 is Tg (A) and the glass transition temperature of the glass to be molded which is the material of the glass lens 14 is Tg (B), Tg. (A) -Tg (B) ≥ 30 ° C. Further, Tg (A) −Tg (B) ≧ 50 ° C. is preferable, and Tg (A) −Tg (B) ≧ 100 ° C. is more preferable.

For example, among the glass materials for glass mold lenses manufactured by the applicant, the one having the highest glass transition point is 612 ° C. (glass material name M-TAFD305). Therefore, by satisfying the condition (2), it is possible to set the molding temperature effective for various glasses to be molded while preventing thermal deformation of the upper mold 40 and the lower mold 60.

Condition (3) is a condition for appropriately managing the difference in the coefficient of thermal expansion between the upper mold 40 or the lower mold 60 and the glass to be molded to prevent the glass to be molded from sticking or cracking and performing good molding. Is. If the coefficient of thermal expansion of the upper mold 40 and the lower mold 60 is too large with respect to the glass to be molded, the glass to be molded tends to crack during molding. Further, if the difference in the coefficient of thermal expansion between the upper mold 40 or the lower mold 60 and the glass to be molded is too small, the glass to be molded tends to stick to the upper mold 40 or the lower mold 60.

More specifically, the average coefficient of thermal expansion (100 ° C. to 300 ° C.) of the glass that is the material of the upper mold 40 and the lower mold 60 is α (A), and the average coefficient of thermal expansion (the average thermal expansion coefficient) of the glass to be molded that is the material of the glass lens 14. When α (B) is defined as (100 ° C to 300 ° C), α (A) −α (B) is preferably +20 to −120. Further, α (A) −α (B) is preferably +10 to −120, and α (A) −α (B) is more preferably 0 to −100. Most of the glass materials for glass mold lenses have α (B) of around 70 to 90, and by satisfying the condition (3), the effect of preventing the glass to be molded from cracking and sticking to the upper mold 40 and the lower mold 60. Is obtained.

The condition (3) is also related to the moldability when the upper mold 40 and the lower mold 60 are press-molded by the master mold. As an example, when a master mold is formed using silicon carbide (SiC) as a main material, the average coefficient of thermal expansion (100 ° C to 300 ° C) of silicon carbide is about 40 × ^10-7 / ° C. The upper mold 40 and the lower mold 60 made of glass can be obtained by satisfactorily molding the glass material for a molding mold. In particular, by satisfying the lower limit of the condition (3), the coefficient of thermal expansion of the master mold does not become relatively excessive, and cracks can be less likely to occur during the manufacture of the upper mold 40 and the lower mold 60.

For example, according to the following raw material composition, it is possible to obtain a glass material for molding that satisfies the conditions (1), (2) and (3).
50-75% SiO ₂ in mol% display,
Al ₂ O ₃ 0-5%,
ZnO is 0-5%,
Na ₂ O and K ₂ O in total 3-15%,
MgO, CaO, SrO and BaO total 14-35%,
ZrO ₂ , TiO ₂ , La ₂ O ₃ , Y ₂ O ₃ , Yb ₂ O ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ and HfO ₂ in total 2-9%,
Including
A glass having a molar ratio {(MgO + CaO) / (MgO + CaO + SrO + BaO)} in the range of 0.85 to 1 and a molar ratio { _{Al2O 3 /} (MgO + CaO)} in the range of 0 to 0.30.

The molding process of the glass lens 14 by the glass lens molding die 10 having the above configuration will be described. First, the upper mold 40 and the upper mold base material 30 are inserted in this order from above with respect to the internal space S of the body mold 20 by assembling the parts in the preparatory stage. The regulated surface 42 abuts on the upper mold restricting surface 23 in the body mold 20 to prevent the upper mold 40 from falling downward. The alignment surface 32 of the upper mold base material 30 comes into contact with the alignment surface 45 of the upper mold 40, and the downward movement of the upper mold base material 30 is also restricted. Specifically, the upper die unit 11 is in the state shown in FIG. Further, the alignment surface 63 of the lower mold 60 is placed on the alignment surface 54 of the lower mold base material 50.

Since the upper mold regulation surface 23 and the regulated surface 42 are each a part of the conical surface centered on the reference axis X, when the weights of the upper mold 40 and the upper mold base material 30 are added, the upper mold regulation surface 23 The restricted surface 42 is pressed against the surface, and the movement of the upper mold 40 downward is restricted, and the position of the upper mold 40 in the radial direction is also kept constant. Therefore, the position of the upper die 40 in the body die 20 is stable, the upper die 40 is less likely to rattle in the body die 20 due to an external force, and the impact on the upper die 40 can be suppressed.

Subsequently, as shown in FIG. 1, the glass lens molding die 10 is set in the ready state for press molding. Specifically, the glass preform 13 is placed on the molding surface 61 of the lower mold 60, the lower mold base material 50 is moved upward by the driving means 71, and the small diameter portion 52 is inserted from below with respect to the body mold 20. do. When the large diameter portion 51 abuts on the lower end of the body mold 20, further insertion of the small diameter portion 52 is restricted, and the positions of the body mold 20 and the lower mold base material 50 in the vertical direction are determined.

When the small diameter portion 52 of the lower mold base material 50 and the lower mold 60 are inserted into the body mold 20, the glass preform 13 supported on the molding surface 61 comes into contact with the molding surface 41 of the upper mold 40. Since the glass preform 13 has a shape having a larger vertical thickness than the molded glass lens 14, the upper mold 40 and the upper mold 40 are placed while the glass preform 13 is sandwiched between the molding surface 41 and the molding surface 61. The mold base material 30 is pushed upward in the internal space S of the body mold 20. Due to this movement, the regulated surface 42 of the upper die 40 is separated upward from the upper die regulating surface 23 of the body die 20 (see FIG. 1). Further, the alignment surface 45 of the upper mold 40 pushes up the alignment surface 32 of the upper mold base material 30 from below, and a part of the upper mold base material 30 projects upward from the upper end of the body mold 20 (FIG. 1). reference).

In the state where the preparation for press molding is completed as shown in FIG. 1, the alignment surface 32 of the upper die base material 30 and the alignment surface 45 of the upper mold 40 come into contact with each other, and a force due to the weight of the upper mold base material 30 is applied. is recieving. Therefore, the upper mold 40 is centered with respect to the upper mold base material 30 by the centering surfaces 32 and 45, and the central axis of the upper mold 40 is in a state of coincident with the reference axis X. At this stage, the suction source 15 may be driven to suck the upper die 40 to increase the force of bringing the alignment surface 45 into contact with the alignment surface 32.

Further, in the state of FIG. 1, the alignment surface 54 of the lower mold base material 50 and the alignment surface 63 of the lower mold 60 are in contact with each other, and the upper mold base material 30, the upper mold 40, the glass preform 13, and the lower mold 60 are in contact with each other. It is under the force of the weight of. Therefore, the lower mold 60 is centered with respect to the lower mold base material 50 by the centering surfaces 54 and 63, and the central axis of the lower mold 60 is in a state of coincident with the reference axis X. At this stage, the suction source 17 may be driven to suck the lower mold 60 to increase the force of bringing the alignment surface 63 into contact with the alignment surface 54.

Subsequently, with the inside of the body mold 20 heated to a molding temperature at which the glass preform 13 can be molded, the upper mold base material 30 is pressed from above to below by the driving means 70 as shown in FIG. Then, the upper mold 40 is pressed downward through the upper mold base material 30, and the distance between the molding surface 41 of the upper mold 40 and the molding surface 61 of the lower mold 60 is narrowed while deforming the heated glass preform 13. Become.

When the upper die 40 and the lower die 60 approach each other, the empty volume of the internal space S of the body die 20 decreases. At this time, the gas in the internal space S (gas generated during press molding of the glass, etc.) is discharged to the outside through the through holes 25 and 26, and the pressure inside the body mold 20 is adjusted. As shown in FIG. 2, the through hole 25 is formed on the side of the outer peripheral surface 46 of the upper mold 40 that has been moved downward by pressing, and the through hole 26 is formed on the side of the outer peripheral surface 64 of the lower mold 60. ing. Therefore, gas can be reliably discharged from both the region of the upper inner surface 21 in which the upper mold unit 11 is inserted and the region of the lower inner surface 22 in which the lower mold unit 12 is inserted.

When the pressure is applied by the driving means 70, a compressive load acts between the upper mold base material 30 and the lower mold base material 50 to adjust the alignment surfaces 32 and 45 in the upper mold unit 11 and the lower mold unit 12. The pressing force in the vertical direction is increased at each of the core surfaces 54 and 63. As the pressing force increases, the effect of positioning on the upper die 40 and the lower die 60 increases, and the pressing process can be performed while reliably restraining the upper die 40 and the lower die 60 without shifting their positions.

The driving means 70 presses the upper mold base material 30 to a position where the upper end surface of the upper mold base material 30 is flush with the upper end surface of the body mold 20 (FIG. 2). For example, the drive means 70 may be provided with a stopper (not shown) that comes into contact with the upper end surface of the body die 20 and is restricted from moving downward. When the upper mold base material 30 is pressed to the position shown in FIG. 2, the step portion 43 of the upper mold 40 slightly enters the inside of the annular protrusion 62 of the lower mold 60, and the molding surface 41, the molding surface 61, and the annular protrusion The glass lens 14 is formed in the space surrounded by the portion 62. At this time, there is a gap between the regulated surface 42 of the upper mold 40 and the upper mold restricting surface 23 of the body mold 20, and the upper mold 40 is not directly restricted by the body mold 20.

When the pressing process shown in FIG. 2 is completed, the inside of the body mold 20 is lowered to a predetermined temperature lower than the molding temperature to cure the glass lens 14. Subsequently, as shown in FIG. 3, the lower mold base material 50 is moved downward by the driving means 71, and the upper mold 40 and the lower mold 60 are separated in the vertical direction. At this time, by driving the suction source 17 to attract and hold the lower mold 60 on the centering surface 54 side of the lower mold base material 50, the lower mold 60 is attached to the upper mold 40 together with the glass lens 14. Instead, the lower mold 60 can be reliably separated downward. When the separation between the upper mold 40 and the lower mold 60 is completed, the glass lens 14 is removed from the lower mold 60. This completes the glass lens 14 in which the molding surfaces 41 and 61 of the upper mold 40 and the lower mold 60 are transferred as the lens surfaces 14a and 14b.

When the lower mold 60 moves downward as shown in FIG. 3, the upper mold 40 is not supported from below by the lower mold unit 12. However, when the regulated surface 42 comes into contact with the upper type restricting surface 23 of the body type 20, the amount of downward movement of the upper type 40 in the body type 20 is limited, and the upper type 40 does not fall off. The form as the upper mold unit 11 can be maintained. Therefore, while the upper mold 40 is not fixed to the upper mold base material 30, the upper mold unit 11 can be handled in the same manner as in the case of the integrally structured molding mold, and excellent productivity can be obtained.

When separating the upper mold 40 and the lower mold 60 as shown in FIG. 3, the suction source 15 may be driven to suck and hold the upper mold 40 on the centering surface 32 side of the upper mold base material 30. .. As described above, since the upper die 40 is restricted from moving downward by the upper die regulating surface 23, the upper die 40 does not follow and fall down while being attached to the lower die 60. By adsorbing and holding the upper die base material 30 side, the stability of the upper die 40 is improved and the glass lens 14 can be easily removed from the molding surface 41.

As described above, in the glass lens molding mold 10 of the present embodiment, the upper mold 40 and the lower mold 60 made of glass, and the upper mold base material 30 and the lower mold base material 50 made of a non-glass material such as metal and ceramics are used. Are combined to form an upper mold unit 11 and a lower mold unit 12.

In both the upper mold unit 11 and the lower mold unit 12, the portion that receives the direct positioning with respect to the body mold 20 and the drive load by the drive means 70 and 71 is an upper mold base material having excellent strength, impact resistance, heat resistance, and the like. It is composed of 30 and a lower base material 50. Therefore, even if the glass lens 14 is repeatedly molded, the accuracy is less likely to be out of order, and a high degree of durability can be obtained. On the other hand, the upper mold 40 and the lower mold 60 made of glass are used for the portions having the molding surfaces 41 and 61 and directly involved in the formation of the glass lens 14, and can be mass-produced at low cost.

The upper mold base material 30 and the upper mold 40 are not fixed to each other, but are brought into contact with the tapered alignment surfaces 32 and 45 that are positioned (aligned) according to the load in the vertical direction. Similarly, the lower mold base material 50 and the lower mold 60 are not fixed to each other, but are brought into contact with the tapered alignment surfaces 54 and 63 that are positioned (aligned) according to the load in the vertical direction. Therefore, the load during heating due to the difference in the coefficient of thermal expansion between the upper mold base material 30 and the upper mold 40 and between the lower mold base material 50 and the lower mold 60 is small, and the upper mold unit 11 and the lower mold unit 11 and the lower mold are less burdened. The individual durability of the mold unit 12 is also excellent. Further, since the allowable range of the difference in the coefficient of thermal expansion between the upper mold base material 30 and the lower mold base material 50 with respect to the upper mold 40 and the lower mold 60 is wide, the degree of freedom in selecting the material is increased.

Further, the direction in which the centering surface 32 and the centering surface 45 are separated from each other by the upper die restricting surface 23 provided on the body die 20 with respect to the upper die 40 which is used as a separate body from the upper die base material 30. The amount of movement to is restricted. As a result, even when the lower mold unit 12 is separated, the upper mold 40 can be held on the upper mold unit 11 side, and the next molding step can be executed as it is. Although the structure is such that the upper mold 40 and the lower mold 60 made of glass are not fixed, the operation performed by using the drive means 70 and the drive means 71 is as simple as the case of using the integrally configured molding mold. Since it can be formed, the efficiency of molding is high and complicated control is not required. Further, the contact of the regulated surface 42 with the upper mold restricting surface 23 is configured so as not to occur in the operation when the glass lens 14 is press-molded (see FIG. 2), which does not affect the molding accuracy. not.

As described above, the glass lens molding die 10 of the present embodiment is excellent in productivity, durability, high accuracy, and practicality. However, the present invention is not limited to the above embodiment, and various modifications can be made within the gist of the invention.

For example, in the above embodiment, both the upper mold unit 11 and the lower mold unit 12 are provided with a glass upper mold 40 and a lower mold 60, and a metal or ceramic upper mold base material 30 and a lower mold base material 50. It consists of a combination. Unlike this, for the portion corresponding to the lower mold unit 12, it is possible to select a molding mold having an integrated structure without dividing into two parts. In this case, the integrated molding mold that replaces the lower mold unit 12 may be made of glass or may be made of non-glass such as metal or ceramics.

In the above embodiment, the upper inner surface 21 of the cylinder 20 and the slide guide surface 31 of the upper base material 30, the lower inner surface 22 of the cylinder 20 and the slide guide surface 53 of the lower base material 50 are centered on the reference axis X, respectively. It is a cylindrical surface. However, the upper inner surface 21 and the slide guide surface 31, and the lower inner surface 22 and the slide guide surface 53 move the upper base material 30 and the lower base material 50 up and down with respect to the body mold 20 without causing tilt or rattling, respectively. Various shapes can be selected as long as they are moved relative to each other in the direction. For example, a surface having a cross-sectional shape perpendicular to the reference axis X, such as a polygon or an ellipse, may be used.

When the upper die unit 11 and the lower die unit 12 are separated from each other, the regulating portion (regulating surface) that limits the amount of movement of the upper die 40 downward is a conical surface such as the upper die regulating surface 23. Is preferable. As described above, the configuration in which the conical controlled surface 42 abuts on the conical upper restricted surface 23 is excellent in the stability of the upper die 40 at the time of contact, and the upper die 40 is incompatible. There is little risk of moving easily and colliding with the surroundings and being damaged. Further, since the upper die 40 is supported in the entire circumferential direction, it is difficult for a local load to be applied to the upper die 40.

However, paying attention to the fact that the movement of the upper die 40 is restricted downward, it is possible to select a regulatory surface having a shape other than the upper die regulation surface 23. As an example, the body type 20 can be provided with a flat (staircase) regulation surface perpendicular to the reference axis X.

In addition, instead of the configuration that continues uninterrupted in the circumferential direction centered on the reference axis X as in the upper type regulating surface 23 (protruding portion 24), a regulating portion (regulating surface) partially provided in the circumferential direction is selected. It is also possible to do. For example, if it has a certain length or more in the circumferential direction, it is divided into two places, and if it is short in the circumferential direction, it is divided into three places (or four places) or more, and the part corresponding to the protruding portion 24 is intermittently divided. Can be provided.

In the above embodiment, the upper mold unit 11 provides conical alignment surfaces 32 and 45 on both the upper mold base material 30 and the upper mold 40, and the lower mold unit 12 provides both the lower mold base material 50 and the lower mold 60. Is provided with conical alignment surfaces 53 and 63. As a modification, a conical centering surface is provided only on one of the upper mold base material 30 and the upper mold 40, or one of the lower mold base material 50 and the lower mold 60, and the other side is in contact with a shape other than the conical surface. It is also possible to provide a part. In this case, the contact portion may have a shape in which the radial position is determined when pressed against the conical centering surface, and various shapes can be selected.

In the above embodiment, the inner diameter of the upper inner surface 21 of the body mold 20 is set to be larger than the inner diameter of the lower inner surface 22, but the inner diameter of the lower inner surface 22 is larger than that of the upper inner surface 21, or the upper inner surface 21 and the lower inner surface are larger. It is also possible to adopt a configuration in which the inner diameters of 22 are equal.

In the above embodiment, when the upper mold 40 and the lower mold 60 are brought close to each other (FIG. 2), the upper mold base material 30 is pressed downward by the driving means 70, and the upper mold 40 and the lower mold 60 are separated from each other. In FIG. 3 (FIG. 3), the lower base material 50 is moved downward by the driving means 71. It is also possible to perform the operation of the molding mold in a form different from this.

As a different example of the operation of the molding mold, the lower mold base material 50 and the lower mold 60 may be moved upward after fixing the upper mold base material 30 during the pressing operation from the prepared state of FIG.

As a further different example, the upper mold 40 may be moved upward when the upper mold 40 and the lower mold 60 are separated from each other from the completion of the press molding shown in FIG. In this case, it is possible to select a first form in which an upward moving force is applied to the body mold 20 and a second form in which an upward moving force is applied to the upper mold base material 30.

In the first embodiment in which the body mold 20 is moved upward, the upper mold regulating surface 23 abuts on the regulated surface 42 to transmit an upward moving force to the upper mold 40, and the upper mold 40 to the upper mold base. The upward movement force is transmitted to the material 30. At this time, since the upper die regulating surface 23 and the regulated surface 42 have a conical shape centered on the reference axis X, the upper die 40 is moved upward without being displaced in the radial direction. As a result, the glass lens 14 can be separated upward from the molding surface 61 of the lower mold 60 without applying an unnecessary load.

In the second embodiment in which the upward moving force is applied to the upper mold base material 30, the suction source 15 is driven to suck and hold the upper mold 40 on the centering surface 32 side of the upper mold base material 30. As a result, the upper mold 40 can be surely separated upward without being stuck to the lower mold 60 together with the glass lens 14.

The lower mold 60 of the above embodiment is a type in which the outer peripheral surface of the edge portion 14c is formed by the annular protrusion 62, and the basic shape of the glass lens 14 is completed by one pressing molding. Unlike this, it is also possible to select a molding die having a structure that does not surround the outer peripheral surface of the edge portion 14c (the lower die 60 does not have the annular protrusion 62). In this case, after the press molding, a process is performed to remove the surplus portion protruding from the peripheral edge of the glass lens 14.

10: Glass lens molding mold 11: Upper mold unit 12: Lower mold unit (opposed type)
13: Glass preform 14: Glass lens 14a, 14b: Lens surface 14c: Edge portion 15, 17: Suction source 20: Body type 21: Upper inner surface 22: Lower inner surface 23: Upper mold restricting surface 24: Protruding portion 30: Upper Mold base material (mold base material)
31: Slide guide surface 32: Alignment surface (contact part on the base material side)
33: Bottom surface 34: Suction hole 40: Upper mold (glass molding mold)
41: Molding surface 42: Controlled surface 43: Stepped portion 45: Alignment surface (mold side contact portion)
50: Lower mold base material (second mold base material)
51: Large diameter portion 52: Small diameter portion 53: Slide guide surface 54: Alignment surface (second base material side contact portion)
57: Suction hole 60: Lower mold (second glass molding mold)
61: Molding surface (second molding surface)
62: Circular protrusion 63: Alignment surface (second mold side contact portion)
64: Outer peripheral surface 70, 71: Drive means S: Internal space X: Reference axis (axis line)

Claims (4)

In a glass lens molding mold that press-molds a glass lens,
A body type with an internal space that extends in the direction of mold movement,
A metal or ceramic mold base material that is movably inserted into the internal space of the body mold in the mold movement direction and has a base material side contact portion at one end in the mold movement direction.
It is made of glass having a glass transition temperature higher than that of the glass to be molded, which is the material of the glass lens, and faces the molding surface forming one lens surface of the glass lens and the side opposite to the molding surface in the mold moving direction. A glass molding mold having a mold-side contact portion that can be brought into contact with the base material-side contact portion,
A facing mold having a second molding surface facing the molding surface and forming the other lens surface of the glass lens, and being movable relative to the glass molding mold and the mold moving direction.
Equipped with
At least one of the base material side contact portion and the mold side contact portion has a centering surface that is a part of a conical surface centered on an axis extending in the mold moving direction, and the base material side contact portion. The glass molding mold is held at a fixed position with respect to the mold base material by the contact between the portion and the mold side contact portion in the mold moving direction and the direction perpendicular to the mold moving direction.
The glass molding mold has a regulated surface around the molding surface.
Inside the body mold, a regulating surface facing the regulated surface in the mold moving direction is provided.
The contact of the regulated surface with the regulated surface limits the amount of movement of the glass molding mold with respect to the body mold in the direction of separating the mold side contact portion from the base material side contact portion. A glass lens molding mold featuring. The glass lens molding mold according to claim 1, wherein the regulated surface and the regulated surface are each formed of a part of a conical surface centered on the axis. The glass lens molding die according to claim 1 or 2, wherein the regulated surface and the regulated surface are separated from each other in a state where the glass lens is press-molded between the molded surface and the second molded surface. The facing type is
With a second mold base material made of metal or ceramics, which is movably inserted into the internal space of the body mold in the mold moving direction and has a second base material side contact portion at one end in the mold moving direction. ,
The second base is made of glass having a glass transition temperature higher than that of the glass to be molded, which is the material of the glass lens, and faces the second molding surface and the side opposite to the second molding surface in the mold moving direction. A second glass molding die having a second mold-side abutting portion that can be brought into contact with and detached from the material-side abutting portion,
Equipped with
At least one of the second base material side contact portion and the second mold side contact portion has a centering surface that is a part of a conical surface centered on the axis line, and the second base material has a centering surface. Due to the contact between the side contact portion and the second mold side contact portion, the second glass molding mold is moved to the mold moving direction and the direction perpendicular to the mold moving direction with respect to the second mold base material. The glass lens molding die according to any one of claims 1 to 3, which is held in a fixed position in the above.

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