WO2019235443A1

WO2019235443A1 - Mold for molding glass lens

Info

Publication number: WO2019235443A1
Application number: PCT/JP2019/022039
Authority: WO
Inventors: 藤本　忠幸
Original assignee: Hoya株式会社
Priority date: 2018-06-04
Filing date: 2019-06-03
Publication date: 2019-12-12
Also published as: CN112218832B; CN112218832A; JP7066533B2; CN115806380A; JP2019210176A

Abstract

A mold for molding a glass lens, said mold comprising: a drum mold; a mold base material that is inserted into the drum mold in a movable state along the moving direction of the mold and has a base material-side contact part at one end thereof; a molding mold formed of glass that has a molding surface for forming one lens surface of the glass lens and a mold-side contact part attachable to and detachable from the base material-side contact part; and an opposite mold that has a second molding surface for forming the other lens surface of the glass lens. The base material-side contact part and/or the mold-side contact part have an aligning surface constituting a part of a conical surface, said conical surface centering on an axis which extends in the moving direction of the mold. By bringing the base material-side contact part into contact with the mold-side contact part, the molding mold formed of glass is held at a definite position in the moving direction of the mold and the direction perpendicular to the moving direction of the mold relative to the mold base material. By bringing a regulated surface provided around the molding surface of the molding mold formed of glass into contact with a regulating surface within the drum mold, the moving amount of the molding mold formed of glass relative to the drum mold in a direction of separating the mold-side contact part from the base material-side contact part is restricted.

Description

Glass lens mold

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

In the production of glass lenses, a method in which a glass as a raw material is roughly shaped and then finished by grinding or polishing is conventionally used. In recent years, a method of producing a glass lens without performing grinding or polishing by performing press molding with a molding die (hereinafter referred to as a molding die) on glass that has been softened by heating has been put into practical use. (For example, Patent Document 1). By molding using such a mold, not only spherical lenses but also aspherical lenses with complicated shapes can be produced in large quantities at low cost.

In press molding, since the surface shape (molding surface) of the molding die is transferred to the molding object, the accuracy of the molding die is extremely demanded. For example, the mold is required to have high rigidity and heat resistance so as not to cause deformation caused by a load or heating that acts during pressing. In addition, in order to prevent sticking of the molding object to the molding die and cracking of the molding object, it is necessary that the molding die have an appropriate coefficient of thermal expansion with respect to the molding object.

Molds made of metal, ceramics, etc. are widely used to satisfy the above conditions. However, it is costly and troublesome to individually manufacture such a mold by cutting or the like while suppressing variation in accuracy. In particular, when mass-producing glass lenses for optical equipment, a large number of molds are required. As a countermeasure, a technique using a glass mold has been proposed (for example, Patent Documents 2 and 3).

Specifically, a master mold (mother mold) having a standard molding surface is prepared, and a molding glass material softened by heating is press-molded with the master mold, thereby transferring the molding surface of the master mold. A glass mold (hereinafter referred to as a glass mold) is obtained. Glass molds have the advantage that once a high-precision master mold is manufactured, mass production is easy and the degree of freedom of shape setting is high.

Japanese Patent Laid-Open No. 6-127756 Japanese Patent No. 2616964 Japanese Patent Laid-Open No. 2-102136

As a problem with glass molds, it may be difficult to ensure heat resistance when repeatedly molding at high temperatures and impact resistance against external impacts compared to metal and ceramic molds. Improvement of the property was desired. As a countermeasure against this, in Patent Document 3, a joined body made of a metal or ceramic having substantially the same coefficient of thermal expansion (linear expansion coefficient) as that of the glass material constituting the glass mold is joined and integrated with the glass mold. ing.

However, the structure for joining a joined body made of another material to a glass mold requires a thermal expansion coefficient of the joined body equal to that of the glass mold, so that the degree of freedom in material selection is low. . In addition, since it is difficult to make the thermal expansion coefficients of the glass mold and the joined body completely coincide with each other, if the heating is performed in an integrated state by joining, stress is applied to the joint portions due to the difference in the thermal expansion coefficient. It is inevitable. Furthermore, when integrating the glass mold and the joined body, the central axis of the glass mold (the optical axis of the lens molded by the glass mold) and the center axis of the joined body are matched 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 mold by combining a cavity die having a cavity surface for molding a glass lens and a mold made of a material having a smaller linear expansion coefficient than the cavity die. The die is formed with a frustoconical hole whose diameter gradually increases as it goes to the tip side (the side having the molding surface) of the cavity die, and the hole is fitted into the cavity die. The inner peripheral surface of the mold hole and the peripheral surface of the cavity die are tapered surfaces that can overlap with each other, and the center axis of the cavity die and the mold is shifted in the overlapping state of the tapered surfaces. Can be prevented. However, since the cavity die and the mold are not joined, the cavity die may drop off from the mold in a state where the mold is separated, and the practicality is low.

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

The present invention relates to a glass lens mold that press-molds a glass lens, a body mold having an internal space extending in the mold movement direction, and an end of the mold movement direction that is inserted into the internal space of the cylinder mold so as to be movable in the mold movement direction. A mold base made of a metal or ceramic having a base-side abutting portion and a glass having a glass transition temperature higher than that of the glass to be molded, which is a glass lens material, and forming one lens surface of the glass lens A glass mold having a surface and a mold side abutting portion that is opposite to the molding surface in the direction of movement of the mold and can be contacted and separated from the base material side abutting portion, and facing the molding surface of the glass mold And a second molding surface that forms the other lens surface of the glass lens, and a glass molding die and an opposing die that can be relatively moved in the mold movement direction. At least one of the substrate-side contact portion and the mold-side contact portion has a centering surface that is a part of a conical surface centering on an axis extending in the mold movement direction, and the substrate-side contact portion and the mold side The glass mold is held at a fixed position in the mold moving direction and in the direction perpendicular to the mold moving direction with respect to the mold substrate by the contact of the contact portion. Further, the glass mold has a regulated surface around the molding surface, and the body mold has a regulating surface facing the regulated surface in the mold moving direction, and the regulated surface abuts against the regulating surface. This restricts the amount of movement of the glass mold relative to the body mold in the direction of separating the mold side contact part from the substrate side contact part.

It is preferable that each of the regulating surface and the regulated surface is composed of a part of a conical surface having a central axis common to the alignment surface. Thereby, the stability of the glass mold with respect to the mold substrate can be enhanced in a state where the regulating surface and the regulated surface are in contact with each other.

In the state in which the glass lens is press-molded between the molding surface and the second molding surface, the regulated surface and the regulating surface are set apart from each other. Thus, the regulating surface and the regulated surface do not affect the positional accuracy of the glass mold and the opposed mold during press molding.

The facing mold can be constituted by a second mold base made of metal or ceramics and a second glass mold made of glass having a glass transition temperature higher than that of the glass to be molded which is a material of the glass lens. The second mold base is inserted into the interior space of the body mold so as to be movable in the mold movement direction, and has a second base-side contact portion at one end in the mold movement direction. The second glass mold is a second mold that can be moved toward and away from the second base surface side contact portion, facing the second molding surface and the second molding surface in the mold moving direction. And a side abutting portion. At least one of the second base-side contact portion and the second die-side contact portion has a centering surface that is a part of a conical surface with the axis as the center, and the second base material The second glass mold is held at a fixed position in the mold moving direction and in the direction perpendicular to the mold moving direction with respect to the second mold base by the contact between the side contact portion and the second mold side contact portion. To do.

According to the glass lens mold of the present invention described above, a portion having a molding surface for molding the lens surface of the glass lens is a glass mold, and a metal or ceramic mold base that is in contact with the glass mold is provided. It is movably supported in the body mold. Therefore, the glass mold can be mass-produced at low cost, and the durability can be improved by the mold base having excellent heat resistance and impact resistance. In addition, the glass mold and the mold base are not bonded and fixed, but the relative position is determined by the contact of the mutual abutting portions. Therefore, the load due to the difference in thermal expansion coefficient between the glass mold and the mold base is determined. In addition to being able to obtain high-precision mold accuracy, there is a high degree of freedom in selecting materials for glass molds and mold bases. In addition, since it has a regulating surface and a regulated surface that limit the amount of movement of the glass mold in the direction away from the mold base, it can be handled and operated while the glass mold and mold base are not fixed. It is easy and excellent practicality can be obtained.

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

A glass lens mold 10 of the present embodiment is a glass preform that is a glass to be molded before molding by relatively moving an upper mold unit 11 and a lower mold unit (opposing mold) 12 along a reference axis (axis line) X. The glass lens 14 (FIGS. 2 and 3) is molded by pressing 13 (FIG. 1).

As shown in FIG. 3, the glass lens 14 is an aspherical lens in which both

lens surfaces

14a and 14b are aspherical, with one lens surface 14a being concave and the other lens surface 14b being convex. An annular edge portion 14 c is formed on the periphery of the glass lens 14.

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

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

The barrel mold 20 is a cylindrical body surrounding the reference axis X, and has an internal space S (FIG. 3) penetrating in the vertical direction. 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 the predetermined range in the vertical direction from the lower end side. Each of the upper inner surface 21 and the lower inner surface 22 is a cylindrical surface (cylindrical inner surface) 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 barrel mold 20, an upper mold regulating 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 projecting portion 24 projecting in the inner diameter direction in an annular shape continuously in the circumferential direction, and an upper mold regulating surface 23 is formed on the projecting portion 24. The upper die restricting surface 23 is a part of a conical surface (conical inner surface) centered on the reference axis X, and the diameter decreases as it proceeds downward. That is, the upper mold restricting surface 23 has a tapered shape that increases the protruding amount toward the inner diameter side as it moves away from the upper inner surface 21.

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

The upper mold base 30 is inserted into the body mold 20 so as to be movable in the vertical direction. 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 on the outer surface of the upper mold base 30. Due to the contact between the upper inner surface 21 and the slide guide surface 31, the center axes of the body mold 20 and the upper mold substrate 30 coincide with each other. The central axes of the body mold 20 and the upper mold base 30 coincide with the reference axis X. In addition, the slide guide surface 31 is supported so as to be slidable in the vertical direction with respect to the upper inner surface 21 without causing inclination or rattling. A rotation restricting structure may be provided between the body mold 20 and the upper mold base 30 so as to prevent relative rotation of the body mold 20 and the upper mold base 30 in the circumferential direction around the reference axis X. .

The glass lens mold 10 includes a drive unit 70 that moves the upper mold base 30 in the vertical direction with respect to the barrel mold 20, and a drive unit 71 that moves the lower mold base material 50 in the vertical direction with respect to the barrel mold 20. Have

A centering surface (base material side contact portion) 32 and a bottom surface 33 are formed at the lower end (one end in the mold movement direction) of the upper mold base material 30. The alignment surface 32 is a part of a conical surface (conical inner surface) centered on the reference axis X, and decreases in diameter as it progresses upward. The bottom surface 33 is a plane that closes the upper end of the alignment surface 32. The lower end of the upper mold base 30 is a mortar-shaped recess formed by a tapered alignment surface 32.

The upper mold base 30 is formed with a suction hole 34 penetrating 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 at the center of the bottom surface 33. The upper end of the suction hole 34 opens to the upper end surface of the upper mold base 30 and is connected to the suction pipe 16 extending from the suction source 15.

Vacuum gas replacement is performed when the glass lens mold 10 is molded in a completed state (FIG. 1). At that time, the suction source 15 is driven to release air between the bottom surface 33 of the upper mold base 30 and the upper surface 44 of the upper mold 40 through the suction pipe 16 and the suction hole 34. Further, by using the suction structure from the suction source 15 to the suction hole 34, the upper mold 40 is sucked and held in the concave portion (the area surrounded by the alignment surface 32 and the bottom surface 33) of the upper mold base 30. Force can be applied.

The lower mold base 50 has a large-diameter portion 51 and a small-diameter portion 52 that has a smaller diameter than the large-diameter portion 51 and protrudes upward from the large-diameter portion 51. The large diameter part 51 has substantially the same outer diameter size as the body mold 20. 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 on the outer surface of the small diameter portion 52.

The lower mold base 50 is capable of inserting and removing the small diameter portion 52 from below with respect to the trunk mold 20. In the inserted state of the small-diameter portion 52 with respect to the trunk mold 20, the concentricity between the trunk mold 20 and the lower mold base 50 is maintained by the contact between the lower inner surface 22 and the slide guide surface 53 (the center of the lower mold base 50). The axis coincides with the reference axis X). In addition, the slide guide surface 53 is supported so as to be slidable 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 50 so as to prevent relative rotation of the body mold 20 and the lower mold base 50 in the circumferential direction around the reference axis X. .

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

A centering surface (second base material side contact portion) 54, a concave portion 55, and an inner peripheral surface 56 are formed at the upper end (one end in the mold movement direction) of the lower die base material 50. The alignment surface 54 is a part of a conical surface (inside the conical surface) centered on the reference axis X, and decreases in diameter as it proceeds 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 (cylindrical inner surface) centered on the reference axis X, and protrudes upward from the upper end edge of the alignment surface 54. The upper end of the lower mold base 50 is a mortar-shaped recess that includes a tapered alignment surface 54 on the inner surface.

The lower mold base 50 is formed with suction holes 57 penetrating 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 of the glass lens mold 10 (FIG. 1), the suction source 17 is driven and the concave portion 55 of the lower mold base 50 and the lower mold 60 are passed through the suction pipe 18 and the suction hole 57. Bleed air between. Further, using the suction structure from the suction source 17 to the suction hole 57, the lower mold 60 is adsorbed to the upper end portion (the concave portion surrounded by the alignment surface 54, the concave portion 55, and the inner peripheral surface 56). A holding suction force 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 opposite sides. In the upper mold 40, the side having the molding surface 41 is the front side, and the opposite side is the back side. Similarly, in the lower mold | type 60, let the side which has the molding surface 61 be a surface side, and let the opposite side be a back surface side. The molding surface 41 and the molding surface 61 are aspheric surfaces having shapes corresponding to the one lens surface 14a and the other lens surface 14b of the glass lens 14, respectively. The molding surface 61 has a cylindrical surface portion corresponding to the edge portion 14c on the periphery of the concave surface portion corresponding to the convex shape of the lens surface 14b. The present invention can also be applied to the molding of glass lenses other than the glass lens 14 shown in the figure, 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 glass to be formed that constitutes the glass lens 14. The coating layer may have a single layer structure, or a coating layer having a multilayer structure composed of different compositions may be provided. Alternatively, a configuration in which the molding surface 41 and the molding surface 61 are exposed without the coating layer can be selected.

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

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

The upper die 40 further has a cylindrical outer peripheral surface 46 formed between the regulated surface 42 and the alignment surface 45. The outer diameter 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 separated from the upper inner surface 21 in the radial direction in the positioning state of the upper mold 40 described later.

The position of the upper mold 40 relative to the upper mold substrate 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 come into surface contact with each other, and abut on each other in a state in which their central axes (straight lines extending in the height direction of the cone and passing through the apex) coincide. With this contact, the position of the upper mold 40 in the vertical direction with respect to the upper mold substrate 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 in a state where the upper mold substrate 30 is housed in the body mold 20, each of the upper mold substrate 30 and the upper mold 40. The central axis of this coincides with the reference axis X. That is, the upper mold 40 is properly aligned with the body mold 20 and the upper mold substrate 30, and the reference axis X passes through the center of the molding surface 41.

In the positioning state of the upper mold 40 where the alignment surface 32 and the alignment surface 45 abut, there is a gap in the vertical direction between the bottom surface 33 and the upper surface 44. Further, in the positioning state, there is a radial gap between the upper inner surface 21 and the outer peripheral surface 46. Thereby, only the alignment surface 32 is positioned by directly contacting the upper die 40, and the portions other than the alignment surface 32 do not hinder the positioning of the upper die 40.

As described above, the upper mold unit 11 is constituted by the upper mold substrate 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 including a molding surface 41 for molding the glass lens 14 in the upper mold unit 11, and the upper mold substrate 30, which is the other part, has heat resistance and impact resistance compared to glass. It is made of metal and ceramics with excellent properties. In particular, the upper mold base 30 is a part that slides with respect to the body mold 20 or receives a pressing force from the outside during press molding, which will be described later, and thus is formed of a metal or ceramic having excellent mechanical strength. This is effective and contributes to ensuring the accuracy of the upper mold unit 11 by using the upper mold substrate 30.

The upper mold 40 can be made into a small and simple shape specialized for the molding surface 41 and its periphery, and is easy to manufacture. More specifically, the upper mold 40 surrounds the molding surface 41 and the upper surface 44 positioned on the front and back sides with a conical regulated surface 42, an alignment surface 45, and a cylindrical outer peripheral surface 46. Similar cross-sectional shape. Further, the 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 size of the upper mold unit 11 in the vertical direction. Therefore, the amount of glass constituting the upper mold 40 is small, and the cost can be suppressed when the upper mold 40 is manufactured. Further, when the upper mold 40 is manufactured, there is little shrinkage of the glass due to cooling after molding, and it is easy to perform accuracy control.

The upper mold base 30 and the upper mold 40 are not fixed to each other by bonding or the like, and are configured so that the upper mold 40 is positioned by contact between the aligning surface 32 and the aligning surface 45 that can be contacted and separated. Therefore, even if the coefficients of thermal expansion of the materials constituting the upper mold base 30 and the upper mold 40 are somewhat different from each other, it is difficult for excessive stress to be applied to the mutual boundary (contact) portion during heating. That is, the allowable range of the coefficient of thermal expansion of each of the materials constituting the upper mold base 30 and the upper mold 40 is wider than the structure in which the upper mold base 30 and the upper mold 40 are relatively fixed, and the selection of the material The degree of freedom is improved.

The upper mold 40 is located below the upper mold substrate 30, and the alignment surface 32 and the alignment surface 45 are conical surfaces that increase in diameter as they progress downward. Therefore, the upper mold base 30 does not restrict 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 barrel mold 20 limits the amount of movement of the upper mold 40 downward. That is, the upper mold 40 is prevented from dropping downward. The upper mold regulating 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 becomes the upper mold regulating surface. It contacts the surface 23 (FIG. 3). The molding surface 41 and the stepped portion 43 of the upper mold 40 have a diameter that can pass through the inside of the upper mold regulating surface 23, and can project downward from the projecting portion 24 (see FIGS. 2 and 3).

On the surface side of the lower mold 60, an annular projecting portion 62 projecting upward from the periphery of the molding surface 61 is formed. When the upper mold 40 and the lower mold 60 are brought close to each other in the vertical direction, the step 43 of the upper mold 40 can enter inside the annular protrusion 62 (see FIG. 2).

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

The lower mold 60 further has an outer peripheral surface 64 that protrudes 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 continues to the position of the annular protrusion 62. A space between the alignment surface 63 and the outer peripheral surface 64 is a curved surface that is gently curved.

The position of the lower mold 60 relative to the lower mold substrate 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 brought into surface contact with each other, and abut on each other in a state in which their respective central axes (straight lines extending in the height direction of the cone and passing through the apex) coincide. Thereby, the position of the lower mold 60 in the vertical direction with respect to the lower mold substrate 50 is determined, and the position of the lower mold 60 in the radial direction about the reference axis X is also determined. Then, when the lower die 60 is positioned by the contact between the alignment surface 54 and the alignment surface 63 with the small-diameter portion 52 of the lower mold substrate 50 inserted into the body mold 20 (FIGS. 1 and 2), The respective center axes of the lower mold base 50 and the lower mold 60 coincide with the reference axis X. That is, the lower mold 60 is properly aligned with respect to the body mold 20 and the lower mold substrate 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 abut, there is a gap in the radial direction between the inner peripheral surface 56 and the outer peripheral surface 64. As a result, only the alignment surface 54 is positioned in direct contact with the lower mold 60, and portions other than the alignment surface 54 do not hinder the positioning of the lower mold 60.

Similarly to the upper mold unit 11, the lower mold unit 12 is constituted by a lower mold substrate 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 including a molding surface 61 for molding the glass lens 14 in the lower mold unit 12, and the lower mold substrate 50, which is the other part, has heat resistance and impact resistance compared to glass. It is made of metal and ceramics with excellent properties. In particular, the lower mold base 50 is a part that slides on the barrel mold 20 and receives external pressing force at the time of press molding, which will be described later. Therefore, the lower mold base 50 is formed of a metal or ceramic having excellent mechanical strength. This is effective and contributes to ensuring the accuracy of the lower mold unit 12 by using the lower mold substrate 50.

The lower mold 60 can be made into a small and simple shape specialized for the molding surface 61 and its periphery, 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 alignment surface 45 are located on the front and back sides. Further, the thickness of the lower die 60 in the vertical direction is about a fraction of the size of the entire size of the lower die unit 12 in the vertical direction. Therefore, the amount of glass constituting the lower mold 60 is small, and the cost can be suppressed when the lower mold 60 is manufactured. Further, when the lower mold 60 is manufactured, there is little shrinkage of the glass due to cooling after molding, and it is easy to perform accuracy control.

The lower mold base 50 and the lower mold 60 are not fixed to each other by bonding or the like, and are configured such that the lower mold 60 is positioned by contact between the aligning surface 54 and the aligning surface 63 that can be contacted and separated. Therefore, even if the thermal expansion coefficients of the materials constituting the lower mold base 50 and the lower mold 60 are somewhat different from each other, it is difficult for excessive stress to be applied to the mutual boundary (contact) portion during heating. That is, compared to a configuration in which the lower mold base 50 and the lower mold 60 are relatively fixed, the allowable range of the coefficient of thermal expansion of the material constituting the lower mold base 50 and the lower mold 60 is wide, and the selection of the material The degree of freedom is improved.

A heater (not shown) is provided outside the barrel mold 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) is softened.

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

Each of the upper mold 40 and the lower mold 60 is made of a glass material that satisfies 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) at 100 ° C. to 300 ° C. is 30 × 10 ⁻⁷ / ° C. to 80 × 10 ⁻⁷ / ° C.

Condition (1) relates to the rigidity of the upper mold 40 and the lower mold 60. If bending occurs in the upper mold 40 or the lower mold 60 during the press molding, the shapes of the molding surfaces 41 and 61 are not maintained, and the molding accuracy for the glass lens 14 is affected. When the Young's modulus is 85 GPa or more, even if a predetermined pressing force is applied when the glass lens 14 is molded, it is possible to prevent the upper mold 40 and the lower mold 60 from being bent by a load, and without impairing the accuracy of the molding surfaces 41 and 61. Can be molded.

Condition (2) relates to the influence on the upper die 40 and the lower die 60 due to heating during molding. The glass having a glass transition point higher than that of the glass to be formed as the material of the glass lens 14 is used as the material of 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, only the glass to be molded can be softened without softening the upper mold 40 and the lower mold 60.

More specifically, when the glass transition temperature of the glass that 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 that 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 glass materials for glass mold lenses manufactured by the applicant, the glass transition point having the highest glass transition temperature 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 controlling the difference in coefficient of thermal expansion between the upper mold 40 or the lower mold 60 and the glass to be molded, and preventing the sticking or cracking of the glass to be molded to perform good molding. It is. If the thermal expansion coefficients of the upper mold 40 and the lower mold 60 are relatively large with respect to the glass to be molded, the glass to be molded is liable to be cracked during molding. If the difference in thermal expansion coefficient between the upper mold 40 or the lower mold 60 and the glass to be molded is too small, the glass to be molded is likely to stick to the upper mold 40 or the lower mold 60.

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

The condition (3) also relates 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 thermal expansion coefficient (100 ° C. to 300 ° C.) of silicon carbide is about 40 × 10 ⁻⁷ / ° C., so that the condition (3) Thus, the glass material for forming mold can be formed well to obtain the upper mold 40 and the lower mold 60 made of glass. In particular, by satisfying the lower limit value of the condition (3), the coefficient of thermal expansion of the master mold does not become excessively large, and cracks can hardly occur when the upper mold 40 and the lower mold 60 are manufactured.

For example, according to the following raw material composition, a glass material for a mold that satisfies the conditions (1), (2), and (3) can be obtained.
50 to 75% of SiO ₂ in terms of mol%,
Al ₂ O ₃ 0-5%,
ZnO 0-5%,
3 to 15% in total of Na ₂ O and K ₂ O,
14 to 35% in total of MgO, CaO, SrO and BaO,
2-9% in total of 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 ,
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 {Al ₂ O ₃ / (MgO + CaO)} in the range of 0 to 0.30.

The molding process of the glass lens 14 by the glass lens mold 10 having the above configuration will be described. First, the upper die 40 and the upper die base material 30 are inserted in this order from the upper side into the internal space S of the body die 20 in component preparation as a preparation stage. The regulated surface 42 comes into contact with the upper mold regulating surface 23 in the trunk mold 20, and the upper mold 40 is prevented from falling off. The alignment surface 32 of the upper mold base 30 abuts against the alignment surface 45 of the upper mold 40, and the upper mold substrate 30 is also restricted from moving downward. Specifically, the upper mold unit 11 is in the state shown in FIG. The alignment surface 63 of the lower mold 60 is placed on the alignment surface 54 of the lower mold substrate 50.

Each of the upper mold restricting surface 23 and the regulated surface 42 is a part of a conical surface with the reference axis X as the center. Therefore, when the weight of the upper mold 40 and the upper mold substrate 30 is added, the upper mold restricting surface 23 The regulated surface 42 is pressed against the upper surface, and the downward movement of the upper die 40 is restricted, and the position of the upper die 40 in the radial direction is also kept constant. Therefore, the position of the upper mold 40 in the trunk mold 20 is stabilized, and the upper mold 40 is less likely to rattle in the trunk mold 20 due to external force, and the impact on the upper mold 40 can be suppressed.

Subsequently, as shown in FIG. 1, the glass lens mold 10 is set in a 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 into the body mold 20 from below. To do. When the large-diameter portion 51 comes into contact with the lower end of the trunk mold 20, further insertion of the small-diameter section 52 is restricted, and the positions of the trunk mold 20 and the lower mold substrate 50 in the vertical direction are determined.

When the small-diameter portion 52 of the lower mold base 50 and the lower mold 60 are inserted into the barrel 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 that is thicker in the vertical direction than the glass lens 14 after molding, the glass preform 13 is sandwiched between the molding surface 41 and the molding surface 61 while the upper preform 40 and the upper mold 40 are The mold base 30 is pushed upward in the internal space S of the trunk mold 20. By this movement, the regulated surface 42 of the upper mold 40 is separated upward from the upper mold regulating surface 23 of the trunk mold 20 (see FIG. 1). Further, the alignment surface 45 of the upper mold 40 pushes up the alignment surface 32 of the upper mold substrate 30 from below, and a part of the upper mold substrate 30 protrudes upward from the upper end of the body mold 20 (FIG. 1). reference).

In the state where preparation for press molding is completed as shown in FIG. 1, the alignment surface 32 of the upper mold base 30 and the alignment surface 45 of the upper mold 40 abut, and the force due to the weight of the upper mold substrate 30 is applied. is recieving. Therefore, the upper mold 40 is aligned with respect to the upper mold substrate 30 by the alignment surfaces 32 and 45, and the center axis of the upper mold 40 is in a state where it matches the reference axis X. At this stage, the suction source 15 may be driven to suck the upper die 40, and the force for bringing the alignment surface 45 into contact with the alignment surface 32 may be increased.

Further, in the state of FIG. 1, the alignment surface 54 of the lower mold substrate 50 and the alignment surface 63 of the lower mold 60 are in contact with each other, and the upper mold substrate 30, the upper mold 40, the glass preform 13, and the lower mold 60. The force of the weight of. Therefore, the lower mold 60 is aligned with respect to the lower mold base material 50 by the alignment surfaces 54 and 63, and the center axis of the lower mold 60 is aligned with the reference axis X. At this stage, the suction source 17 may be driven to suck the lower mold 60, and the force for bringing the alignment surface 63 into contact with the alignment surface 54 may be increased.

Subsequently, in the state where the inside of the barrel mold 20 is heated to a molding temperature at which the glass preform 13 can be molded, as shown in FIG. 2, the upper mold base 30 is pressed downward from above by the driving means 70. Then, the upper mold 40 is pressed downward via the upper mold base 30 and the heated glass preform 13 is deformed, and the distance between the molding surface 41 of the upper mold 40 and the molding surface 61 of the lower mold 60 is narrow. Become.

When the upper mold 40 and the lower mold 60 approach each other, the free space in the internal space S of the trunk mold 20 decreases. At this time, the gas in the internal space S (gas generated during the press molding of glass) 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 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 where the upper die unit 11 is inserted and the region of the lower inner surface 22 where the lower die unit 12 is inserted.

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

The driving means 70 presses the upper mold base 30 to a position (FIG. 2) where the upper end face of the upper mold base 30 is flush with the upper end face of the trunk mold 20. For example, the driving means 70 may be provided with a stopper (not shown) that is in contact with the upper end surface of the body mold 20 and receives downward movement restriction. When the upper mold base 30 is pressed to the position of FIG. 2, the step 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 part 62. At this time, there is a gap between the regulated surface 42 of the upper mold 40 and the upper mold regulating surface 23 of the trunk mold 20, and the upper mold 40 is not subjected to direct position regulation by the trunk 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, and the glass lens 14 is cured. Subsequently, as shown in FIG. 3, the lower mold base 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, the lower mold 60 is attached to the upper mold 40 together with the glass lens 14 by driving the suction source 17 to attract and hold the lower mold 60 on the alignment surface 54 side of the lower mold substrate 50. Therefore, 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. Thereby, 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 is completed.

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, since the regulated surface 42 abuts against the upper mold regulating surface 23 of the trunk mold 20, the amount of movement of the upper mold 40 downward in the trunk mold 20 is limited, and the upper mold 40 does not fall off. In addition, the form of the upper mold unit 11 can be maintained. Therefore, the upper mold unit 11 can be handled in the same manner as in the case of the integral structure mold, while the upper mold 40 is not fixed to the upper mold substrate 30, and excellent productivity can be obtained.

3, when the upper mold 40 and the lower mold 60 are separated from each other, the suction source 15 may be driven to hold the upper mold 40 on the alignment surface 32 side of the upper mold substrate 30 by suction. . 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 fall down following the state where the upper die 40 is stuck to the lower die 60. By adsorbing and holding to the upper mold base 30 side, the stability of the upper mold 40 is improved and the glass lens 14 can be easily detached from the molding surface 41.

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

Both the upper mold unit 11 and the lower mold unit 12 are directly positioned with respect to the body mold 20 and the portion that receives the driving load by the driving means 70 and 71 is an upper mold base material excellent in strength, impact resistance, heat resistance, etc. 30 and the lower mold substrate 50. For this reason, even when the molding of the glass lens 14 is repeatedly performed, the accuracy is hardly changed, and a high durability can be obtained. On the other hand, the part which has the molding surfaces 41 and 61 and directly participates in the formation of the glass lens 14 uses the upper mold 40 and the lower mold 60 made of glass, and can be mass-produced at low cost.

The upper mold base 30 and the upper mold 40 are not fixed to each other but are brought into contact with tapered alignment surfaces 32 and 45 that perform positioning (alignment) according to the load in the vertical direction. Similarly, the lower mold base 50 and the lower mold 60 are not fixed to each other but are in contact with tapered alignment surfaces 54 and 63 that perform positioning (alignment) according to the load in the vertical direction. Therefore, there is little burden during heating due to the difference in thermal expansion coefficient between the upper mold base 30 and the upper mold 40 and between the lower mold base 50 and the lower mold 60, and the upper mold unit 11 and the lower mold The individual durability of the mold unit 12 is also excellent. Moreover, since the tolerance | permissible_range of the difference of the thermal expansion coefficient of the upper mold | type base material 30 and the lower mold | type base material 50 with respect to the upper mold | type 40 and the lower mold | type 60 is wide, the freedom degree of selection of material becomes high.

Furthermore, the direction in which the alignment surface 32 and the alignment surface 45 are separated by the upper mold regulating surface 23 provided on the body mold 20 with respect to the upper mold 40 used as a separate body with respect to the upper mold substrate 30. The amount of travel to is limited. Thereby, even if 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 process can be performed as it is. Further, while the structure is such that the glass upper mold 40 and the lower mold 60 are not fixed, the operation performed using the driving means 70 and the driving means 71 is as simple as the case of using the integrally formed mold. As a result, the molding process is efficient and no complicated control is required. Further, the contact of the regulated surface 42 with the upper mold regulating surface 23 is configured not to occur during the operation of pressing the glass lens 14 (see FIG. 2), and does not affect the molding accuracy. Absent.

As described above, the glass lens mold 10 of this 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 said embodiment, both the upper mold | type unit 11 and the lower mold | type unit 12 are the upper mold | type 40 and the lower mold | type 60 made from glass, and the upper mold | type base material 30 and the lower mold | type base material 50 which are metal or ceramics. It consists of a combination. In contrast to this, it is also possible to select a molding die having an integral structure without dividing the portion corresponding to the lower die unit 12 into two parts. In this case, the integrated mold that replaces the lower mold unit 12 may be made of glass or non-glass such as metal or ceramics.

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

When the upper mold unit 11 and the lower mold unit 12 are separated from each other, the restriction portion (restriction surface) that restricts the amount of movement of the upper mold 40 downward is a conical surface like the upper mold restriction surface 23. It is preferable. As described above, the configuration in which the conical regulated surface 42 abuts against the conical upper mold regulating surface 23 is excellent in stability of the upper mold 40 at the time of abutment, and the upper mold 40 is not suitable. There is less risk of moving around and colliding with the surroundings and taking damage. Further, since the upper mold 40 is supported in the entire circumferential direction, a local load is hardly applied to the upper mold 40.

However, if attention is paid to the fact that the movement of the upper mold 40 is regulated downward, it is possible to select a regulating surface having a shape other than the upper mold regulating surface 23. As an example, a planar (stepped) regulating surface perpendicular to the reference axis X can be provided on the body mold 20.

In addition, instead of the structure that continues without interruption in the circumferential direction around the reference axis X like the upper mold 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, the portion corresponding to the protruding portion 24 is intermittently divided into two locations if the length is a certain length in the circumferential direction, and three locations (or four locations) if the length is short in the circumferential direction. Can be provided.

In the above embodiment, the upper mold unit 11 is provided with the conical alignment surfaces 32 and 45 on both the upper mold substrate 30 and the upper mold 40, and both the lower mold substrate 50 and the lower mold 60 are provided in the lower mold unit 12. Are provided with conical alignment surfaces 54 and 63. As a modification, a conical alignment surface is provided only on one of the upper mold base 30 and the upper mold 40, or only one of the lower mold base 50 and the lower mold 60, and the other is in contact with a shape other than the conical surface. It is also possible to provide a part. The contact portion in this case may be a shape that can determine the radial position when pressed against the conical alignment 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 larger than the inner diameter of the lower inner surface 22, but the inner surface of the lower inner surface 22 is larger than the upper inner surface 21, It is also possible to adopt a configuration in which the inner diameters of 22 are equal.

In the above embodiment, when the upper die 40 and the lower die 60 are pressed close to each other (FIG. 2), the upper die substrate 30 is pushed downward by the driving means 70 and the upper die 40 and the lower die 60 are separated. In FIG. 3, the lower mold base 50 is moved downward by the driving means 71. It is also possible to cause the mold to operate in a different form.

As another example of the operation of the mold, the lower mold base 50 and the lower mold 60 may be moved upward after fixing the upper mold base 30 during the pressing operation from the preparation state of FIG.

As a further different example, the upper die 40 may be moved upward when the upper die 40 and the lower die 60 are separated from each other after the press molding in FIG. In this case, a first mode in which an upward movement force is applied to the body mold 20 and a second mode in which an upward movement force is applied to the upper mold base 30 can be selected.

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 and transmits an upward movement force to the upper mold 40, so that the upper mold 40 An upward movement force is transmitted to the material 30. At this time, since the upper mold regulating surface 23 and the regulated surface 42 have a conical shape centered on the reference axis X, the upper mold 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 mode in which an upward movement force is applied to the upper mold base 30, the suction source 15 is driven to hold the upper mold 40 on the alignment surface 32 side of the upper mold base 30. Accordingly, the upper mold 40 can be reliably separated upward without the upper mold 40 being attached 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 projecting portion 62, and the basic shape of the glass lens 14 is completed by one press molding. Unlike this, it is also possible to select a mold having a structure that does not surround the outer peripheral surface of the edge portion 14c (the lower mold 60 does not include the annular protrusion 62). In this case, after the press molding, a process of removing the surplus portion protruding from the peripheral edge of the glass lens 14 is performed.

INDUSTRIAL APPLICABILITY According to the present invention, a glass lens mold having excellent productivity, durability, high accuracy, and practicality can be obtained, and particularly useful for a manufacturing apparatus that is required to efficiently manufacture many glass lenses. It is.

10: Glass lens mold 11: Upper mold unit 12: Lower mold unit (opposed type)
13: Glass preform 14:

Glass lenses

14a, 14b: Lens surface 14c: Edge portions 15, 17: Suction source 20: Body mold 21: Upper inner surface 22: Lower inner surface 23: Upper mold regulating surface 24: Protrusion 30: Upper Mold substrate (mold substrate)
31: Slide guide surface 32: Alignment surface (base material side contact portion)
33: Bottom surface 34: Suction hole 40: Upper mold (glass mold)
41: Molding surface 42: Restricted surface 43: Step 45: Alignment surface (die side contact portion)
50: Lower mold substrate (second mold substrate)
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 mold)
61: Molding surface (second molding surface)
62: annular protrusion 63: alignment surface (second mold side contact portion)
64: outer peripheral surfaces 70, 71: driving means S: internal space X: reference axis (axis)

Claims

In a glass lens mold for press molding a glass lens,
A trunk mold having an internal space extending in the mold movement direction;
A mold base made of metal or ceramic that is inserted into the inner space of the barrel mold so as to be movable in the mold movement direction, and has a base-side contact portion at one end in the mold movement direction;
The glass lens is made of glass having a glass transition temperature higher than that of the glass to be molded, and a molding surface that forms one lens surface of the glass lens, and the direction of movement of the mold facing away from the molding surface. A glass mold having a mold-side contact portion that can contact and separate from the substrate-side contact portion;
A second molding surface that forms the other lens surface of the glass lens opposite to the molding surface, and a counter mold that is relatively movable in the mold movement direction with the glass molding die;
With
At least one of the substrate-side contact portion and the mold-side contact portion has an alignment surface that is a part of a conical surface with an axis extending in the mold movement direction as the center, and the substrate-side contact Holding the glass molding die in a fixed position in the direction perpendicular to the mold movement direction and the mold movement direction with respect to the mold base by the contact of the part and the mold side contact part,
The glass mold has a regulated surface around the molding surface,
In the body mold, having a regulating surface facing the regulated surface in the mold moving direction,
Limiting the amount of movement of the glass mold relative to the body mold in the direction of separating the mold side contact part from the base material side contact part by the contact of the regulated surface with the regulation surface A glass lens mold characterized by
The glass lens mold according to claim 1, wherein each of the regulating surface and the regulated surface comprises a part of a conical surface centered on the axis.
3. The glass lens according to claim 1, wherein the regulated surface and the regulating surface are spaced apart in a state where the glass lens is press-molded between the molding surface and the second molding surface. Mold.
The facing type is
A second mold base made of metal or ceramics, which is inserted into the inner space of the barrel mold so as to be movable in the mold movement direction, and has a second base-side contact portion at one end in the mold movement direction; ,
The second lens is made of glass having a glass transition temperature higher than that of the glass to be molded, which is a material of the glass lens, and faces the second molding surface and the second molding surface opposite to the second molding surface in the mold moving direction. A second glass mold having a second mold side abutting portion that can contact and separate from the material side abutting portion;
With
At least one of the second base-side contact portion and the second mold-side contact portion has an alignment surface that is a part of a conical surface with the axis as the center, and the second base The second glass mold is placed perpendicular to the mold movement direction and the mold movement direction with respect to the second mold substrate by the contact of the material side contact portion and the second mold side contact portion. The glass lens mold according to claim 1 or 2, wherein the glass lens mold is held at a fixed position in a direction.