JP2009242141A - Regenerating method of mold and regenerated mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily regenerate a mold, which has been worn, with a proper clearance. <P>SOLUTION: When the mold for molding a lens which is provided with a molding surface for forming an optical surface of the glass lens, a pair of cores each having a coating film formed at least on a molding surface and a drum mold sliding on the cores is repeatedly used to form a fresh coating film, the inner surface of the drum mold or the side surface of a base material 31 of a core is worn. In the base material 31 having the worn side surface, the coating film is removed while a cutting worked layer 32 on which an optical surface shape of a lens to be molded is accurately formed is left. An oxidation preventive film 43 to compensate for the wear of the base material 31 is formed on the molding surface of the cutting worked layer 32 and the worn side surface of the base material 31 to have a thickness to become D1 diameter before the wear as a regenerating coating film in the base material 31 on which the coating film is removed. A mold releasing film 38 is formed on the oxidation preventing film 43 to become a regenerated core. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for regenerating a lens molding die worn by continuous use and a regenerated die, and more particularly, a method for regenerating a mold and a regenerating die for re-forming a coating film covering the mold. Regarding type.

  Conventional molds for press molding glass lenses include cemented carbides mainly composed of tungsten carbide (WC) and cermets composed mainly of titanium carbide (TiC) and titanium nitride (TiN). Used as a material. Since these mold base materials have extremely high hardness, the grinding process takes a long time, and the cost of the mold has increased. Moreover, in grinding, it may be difficult to process with desired accuracy depending on the surface shape of the optical surface. For this reason, the lens mold is provided with a cutting layer on the base material that is easier to process than the base material, and the cutting layer is cut with a desired accuracy to form the optical surface of the lens. The molding surface.

  In addition, various coating films are provided on the molding surface. For example, in press molding of a glass lens, a glass material is heated by heating the mold to a high temperature of about 400 degrees or higher, and therefore, if the base material or the cutting layer is exposed on the surface of the mold, it is oxidized. . For this reason, an antioxidant film is provided on the molding surface. Further, since the mold presses the glass material at a high temperature as described above, the molding surface and the glass material are fused, and thus a release film is provided to facilitate the peeling of the lens from the mold.

In the mold for lens molding, the dimensional tolerance on the molding surface is on the order of several μm, and the surface roughness of the molding surface is required to be 10 to 20 nm or less in Ra. The various coating films provided on the base material as described above deteriorate and cause surface roughness, partial peeling, and the like, making it impossible to use the mold. For this reason, the mold that has been molded a predetermined number of times is reused by removing the deteriorated coating film by etching and re-depositing the film (Patent Documents 1 and 2).
JP-A-5-32424 JP-A-6-40729

  Molds that are reused by re-coating a coating film are repeatedly molded with tens of thousands to hundreds of thousands of shots on the same base material, but a pair of cores that press the glass material and positioning the cores In the case of a mold composed of a body mold, it is not only the coating film that covers the molding surface that is deteriorated by repeated film formation, but the base material itself is worn on the sides of the core and body mold that slide together. .

  The coating film can be regenerated relatively easily if it is re-formed, but since the base material is made of cemented carbide, it is difficult to repair it if it wears out. If it is worn away, it must be disposed of.

  In addition, although the mold base material is made with a predetermined dimensional accuracy, depending on the combination of the core and the body mold, the clearance may be too small and workability may deteriorate. For this reason, it may be necessary to select the combination of the core and the body mold so that the insertion and removal can be performed smoothly and the relative positional deviation between both optical surfaces of the molded lens is within a predetermined range.

  The present invention has been made in view of the above-described problems, and easily regenerates a mold in which a base material is worn, and regenerates the mold easily adjusting the clearance, and this method. The purpose is to provide a reclaimed mold.

  The mold regeneration method of the present invention includes a pair of cores provided with a molding surface for molding an optical surface of a glass lens, a coating film formed on at least the molding surface, and a barrel mold that slides on the cores. A method for regenerating a lens molding die comprising: once removing the coating film, at least one of the sliding surfaces on which the core and the barrel mold slide has a predetermined diameter after the film formation. The mold is regenerated by forming the same regenerative coating film as the reclaimed coating film.

  The regeneration coating film is formed on the sliding surface of the core.

  The coating film is formed on the sliding surface of the body mold.

  The regeneration coating film is formed to a thickness that compensates for wear of the core.

  The regeneration coating film may be formed to a thickness that compensates for wear of the body mold.

  The regeneration coating film may be formed to a thickness that compensates for wear of the core and wear of the body mold.

  Further, the coating film is provided by laminating a plurality of layers having different purposes of use, and the regeneration coating film is made of a film made of the same material as any one of the plurality of layers. It is characterized by.

  The regeneration coating film is made of titanium aluminum nitride.

  The reproduction mold of the present invention includes a pair of cores provided with a molding surface for molding the optical surface of a glass lens, a coating film formed on at least the molding surface, and a barrel mold that slides on the core. A regeneration mold obtained by forming the coating film on a lens molding mold and regenerating the mold, and is provided after removing the coating film, and at least a sliding surface on which the core and the barrel mold slide. One of them is characterized by including a coating film for regeneration that is the same as the coating film that regenerates the diameter after film formation to a predetermined dimension.

  The regeneration coating film is provided on the sliding surface of the core.

  Further, the coating film is provided on the sliding surface of the body mold.

  The regeneration coating film is provided with a thickness that compensates for wear of the core.

  The regeneration coating film is provided with a thickness that compensates for wear of the body mold.

  Further, the regeneration coating film is provided with a thickness that compensates for wear of the core and wear of the body mold.

  Further, the coating film is provided by laminating a plurality of layers having different purposes of use, and the regeneration coating film is made of a film made of the same material as any one of the plurality of layers. It is characterized by.

  The regeneration coating film is made of titanium aluminum nitride.

  According to the present invention, it is possible to easily regenerate a mold having a worn base material with an appropriate clearance.

  As shown in FIG. 1, a glass lens molding die 11 is a die that presses a preform 12 while heating and molds it into a lens, and includes a core 15 and a trunk die 16.

  The core 15 includes a pair of upper and lower upper molds 17 and 18 that are arranged to face each other. The upper die 17 is provided so as to be movable along the pressing direction (vertical direction), and a molding surface 21 that forms one optical surface of a lens to be molded is provided on the lower surface facing the lower die 18. The lower mold 18 is fixedly disposed at the time of molding the lens, and a molding surface 22 that forms the other optical surface of the lens to be molded is provided on the upper surface facing the upper mold 17. Further, both the upper die 17 and the lower die 18 are provided in a cylindrical shape whose diameter changes in two steps along the pressing direction, and when the tip having a small diameter is inserted into the body die 16, the diameter is large. The root portion hits the trunk mold 16.

  The body mold 16 is provided in a cylindrical shape having an inner diameter substantially equal to the diameters of the upper mold 17 and the lower mold 18 so that the upper mold 17 and the lower mold 18 can freely slide. In addition, the upper mold 17 and the lower mold 18 can be freely inserted and removed. The body mold 16 is fitted into the lower mold 18 so as to be covered from the lower end side when the lens is molded by the mold 11, and then the preform 12 is placed on the molding surface 21 of the lower mold 18 and then the upper end side. The upper die 17 is inserted. When the upper mold 17 and the lower mold 18 are thus inserted into the body mold 16, the horizontal movement of the upper mold 17 and the lower mold 18 is limited, and the molding surface 21 of the upper mold 17 and the molding surface 22 of the lower mold 18 are limited. Are centered with a predetermined accuracy. Further, when the upper mold 17 and the lower mold 18 are inserted into the body mold 16, the movement of the upper mold 17 in the pressing direction is restricted by the base portions of the upper mold 17 and the lower mold 18 abutting against the body mold 16. The

  As shown in FIG. 2A, the upper mold 17 includes a base material 31, a cutting layer 32 provided on the base material 31, and a coating film 33 provided on the cutting layer 32. The base material 31 is made of a cemented carbide obtained by mixing and sintering tungsten carbide and cobalt, and a temporary molding surface 34 is provided at the tip. The temporary molding surface 34 has a curved shape according to the rough curved shape of the surface shape of the lens to be molded.

  The cutting layer 32 is made of electroless nickel plating that is easier to process than the base material 31, and is formed on the temporary molding surface 34 by masking the surface of the base material 31 except the temporary molding surface 34. . This cutting layer 32 is subjected to precision cutting with a diamond bit, and the optical surface shape of the lens to be molded is precisely formed. As long as there is no significant wear or damage, the cutting layer 32 is not removed when the mold 11 to be described later is regenerated, and the same cutting layer 32 is used before and after the regeneration. If the cutting layer 32 is worn or damaged severely while the mold 11 is regenerated and reused, it is removed when the mold 11 is regenerated and a new cutting process is performed. A layer 32 is provided.

  The coating film 33 is provided on the cutting layer 32 and is formed by laminating a plurality of layers having different purposes of use. The coating film 33 includes two layers of an antioxidant film 37 and a release film 38 from the cutting layer 32 side. The antioxidant film 37 is made of titanium aluminum nitride (titanium nitride aluminum) and is formed on the cutting layer 32. The antioxidant film 37 prevents oxidation of the cutting layer 32 that becomes a high temperature when the preform 12 is heated.

  The release film 38 is made of diamond-like carbon (DLC), is formed on the antioxidant film 37, and prevents the preform 12 (or the lens after molding) from being fused to the antioxidant film 37. Improves mold releasability of the molded lens.

  When the molding of the lens is repeated with the mold 11 configured in this way, the coating film 33 deteriorates such as wear or partial peeling, and the optical surface of the lens to be molded is molded with a desired accuracy. Disappear. For this reason, after the molding of the lens with the mold 11 is repeated several thousand times, the deteriorated coating film 33 is removed by etching or the like, the coating film 33 is formed again, and the mold 11 is regenerated.

  Thus, by re-forming the coating film 33, if the mold 11 is continuously used, the coating film 33 is not only deteriorated but also inserted into the body mold 16 as shown in FIG. The side surface 41 (sliding surface) of the portion is worn, and the tip portion of the upper die 17 having the diameter D1 substantially equal to the inner diameter of the body die 16 is reduced to the diameter D2. For this reason, even if only the coating film 33 on the molding surface 21 of the upper mold 42 with the side surface 41 worn is regenerated, a gap is formed between the body mold 16 and the molding surfaces 21 of the upper mold and the lower mold during molding. , 22 may be displaced.

  Therefore, the regeneration of the upper mold 42 where even the side surface 41 is worn is performed as shown in FIG. First, as shown in FIG. 3A, the coating film 33 is removed and the base material 31 and the cutting layer 32 are exposed in the same manner as when the coating film 33 is regenerated.

  Next, as shown in FIG. 3B, an antioxidant film 43 is formed. At this time, the antioxidant film 43 not only covers the cutting layer 32 but is simultaneously formed on the side surface of the base material 31 that has been worn by sliding against the body mold 16. At this time, the amount of wear of the side surface 41 of the upper mold 42 is measured prior to the regeneration of the mold 11, and the worn side surface 41 is applied to the side surface 41 as a coating film for regeneration that serves both to prevent oxidation and regenerate dimensions. An antioxidant film 43 is formed to a thickness that compensates for the amount of wear and has a diameter D1 before wear.

  As shown in FIG. 3C, when the release film 38 is formed on the upper surface of the antioxidant film 43 that becomes the molding surface 21, the upper mold 42 that slides on the barrel mold 16 and wears the side surface 41 is obtained. The diameter of the portion inserted into the body mold 16 is regenerated as a regenerated upper mold 45 (regenerated mold) equal to the diameter D1 before wear.

  As described above, when the upper mold 42 is regenerated, the anti-oxidation film 43 that is normally formed on the molding surface 21 is also provided on the side surface 41 that has been rubbed against the body mold 16 and worn. The clearance when inserted into the is easily adjusted. For this reason, even if the base material 31 is worn, the mold 11 can be easily regenerated with an appropriate clearance. Further, even in a reproduction mold in which the coating film 33 is regenerated repeatedly based on the same base material 31, it is difficult to cause positional deviation between both optical surfaces of the lens to be molded. Further, since the anti-oxidation film 37 that is one of the coating films 33 is provided on the side surface 41, it is easy to perform the process substantially the same as the normal mold 11 regeneration process by simply adjusting the film thickness and the like. The clearance can also be adjusted.

  Moreover, when the antioxidant film | membrane 43 is provided in the side surface 41 of the upper mold | type 42, the slidability of the metal mold | die 11 will improve and a moldability will improve.

  In the embodiment described above, the regeneration of the upper mold 17 will be described as an example. However, the present invention is not limited to this. If the molding is repeated, the lower mold 18 also slides on the body mold 16 and the side surface wears. The mold 17 is also preferably regenerated by forming the antioxidant film 37 on the side surface as described above and adjusting the clearance when inserted into the body mold 16. At this time, when the amount of side wear differs between the upper die 17 and the lower die 18, it is preferable to form a reproduction coating film such as the antioxidant film 43 on each die according to the amount of wear of each die. .

  Further, in the above-described embodiment, the upper die 42 is provided on the side surface 41 of the upper die 42 with an anti-oxidation film 43 having a thickness that compensates for the wear of the side surface 41 of the upper die 42, so Although it reproduces to a dimension, it is not restricted to this, Thickness which measures the amount of wear of the inner surface (sliding surface) of body mold 16 beforehand, and makes up the amount of wear of the inner surface of body mold 16 on the inner surface of body mold 16 Alternatively, a coating film 33 such as an antioxidant film 43 may be formed and regenerated to the dimensions of the body mold 16 before wear. As described above, when the coating film such as the anti-oxidation film 43 is formed on the inner surface of the body mold 16 and the body mold 16 is regenerated to the size before abrasion, the side surface of the core 15 is formed as in the above-described embodiment. However, it is preferable to adjust the clearance between the body mold 16 and the core 15 by forming an anti-oxidation film 43 or the like so as to reproduce the dimensions before each wear.

  Further, in the above-described embodiment, the upper die 42 is provided on the side surface 41 of the upper die 42 with an anti-oxidation film 43 having a thickness that compensates for the wear of the side surface 41 of the upper die 42, so However, the present invention is not limited to this, and the amount of wear on the side surface 41 of the upper die 42 and the amount of wear on the inner surface of the body die 16 are measured in advance prior to the reproduction of the mold 11, so At the same time, the thickness of the upper die 42 is equal to the sum of the amount of wear on the side surface 41 of the upper die 42 and the amount of wear on the inner surface of the die 16 so as to compensate for the wear on the inner surface of the die 16. An antioxidant film 43 may be formed on the side surface 41. As described above, when the antioxidant film 43 is formed so as to compensate for the wear on the inner surface of the body mold 16, the diameter of the upper mold 45 after the reproduction becomes larger than the diameter D 1 of the original upper mold 17. It becomes possible to slide on the barrel mold with an appropriate clearance.

  Further, a regeneration coating film having a thickness corresponding to the amount of wear on the side surface of the core 15 is formed on the inner surface of the body mold 16, and a regeneration coating film having a thickness corresponding to the amount of wear on the inner surface of the body mold 16 is formed on the core. You may form into a film on 15 side surfaces. Further, a regeneration coating film may be formed on the inner surface of the barrel die 16 so as to compensate for the wear amount on the side surface of the core 15 and the wear amount on the inner surface of the barrel die 16.

  Furthermore, in the above-described embodiment, when the side surface 41 of the upper mold 42 and the inner surface of the body mold 16 are uniformly worn regardless of the orientation along the pressing direction and the position along the pressing direction, the mold is used. However, the present invention is not limited to this, and the amount of wear on the side surface 41 of the upper mold 42 and the inner surface of the body mold 16 varies depending on the orientation around the press direction and the position along the press direction. If the wear of the mold 42 and the body mold 16 is not uniform, the film thickness of the antioxidant film provided on the side surface 41 of the upper mold 42 and the inner surface of the body mold 16 is changed accordingly, and the film is formed. It is preferable to regenerate the mold by adjusting the clearance.

  In the above-described embodiment, the clearance can be adjusted by providing the cutting layer 32 and the release film 38 on the worn side surface 41 of the base material 31, and among them, the heat resistance and the wear resistance are excellent. Therefore, it is preferable to adjust the clearance by forming only the antioxidant film 37 on the worn side surface 41 of the base material 31 as in the above-described embodiment.

  In the above-described embodiment, in order to form the antioxidant film 37 on the side surface 41 of the worn base material 31, for example, the side surface of the base material 31 is not masked but is formed by sputtering to form the molding surface. A uniform antioxidant film 37 may be formed not only on the substrate 21 but also on the side surface 41 of the base material 31. Moreover, the thickness of the antioxidant film 37 on the molding surface 21 and the side surface 41 are formed by forming the antioxidant film 37 while rotating or moving the upper mold 42 with respect to the scattering direction of the deposited material. The thickness of the upper antioxidant film 37 can be adjusted.

  In the above-described embodiment, the example in which the regeneration process is performed on the upper mold 42 that is worn by continuous use has been described. However, the present invention is not limited thereto, and the coating film 33 is formed on the new upper mold 17 (lower mold 18). When the combination is provided, an anti-oxidation film 37 may be provided in advance on the side surface of the upper die 17 (lower die 18) to adjust the clearance when inserted into the barrel die 16.

  In the above-described embodiment, the antioxidant film 43 formed on the worn side surface 41 is titanium aluminum nitride. However, the material used for the antioxidant film 43 is not limited to this, and other materials having an antioxidant effect. May be used. Further, in the case where a film having excellent heat resistance and wear resistance is used as the coating film 33 in addition to the antioxidant film 37, a base material in which a heat resistant and wear resistant film other than the antioxidant film 43 is worn. The mold 11 may be regenerated by forming a film on the side surface 31.

  In the above-described embodiment, the antioxidant film 43 is formed on the side surface 41 of the upper mold 42 as a regeneration coating film. However, the present invention is not limited to this, and the oxidation film 43 is oxidized similarly to the coating film 33 provided on the molding surface 21. By using both the prevention film and the release film as a coating film for regeneration, and adjusting the thickness of each layer to form a film on the side surface 41 of the upper mold 42, the size of the worn upper mold 42 may be regenerated. In this way, all of the coating film 33 provided on the molding surface 21 is formed as a reproduction coating film, so that the mold 11 can be formed only by adjusting the thickness of each layer of the reproduction coating film. These dimensions can be easily reproduced at the same time. In the above-described embodiment, only the antioxidant film 43 is formed on the side surface 41 of the upper mold 42 as a reproduction coating film. However, the present invention is not limited to this, and the release film 38 is used as the reproduction coating film of the upper mold 42. A film may be formed on the side surface 41.

  In the above-described embodiment, the regeneration coating film (antioxidation film 43) is provided on the worn side surface 41 at the timing when the coating film 33 is formed again on the molding surface 21. However, the present invention is not limited to this. A reproduction coating film may be provided on the side surface 41 in a step different from the coating film 33 on the molding surface 21. However, since the number of steps can be reduced, it is preferable to form the antioxidant film on the side surface 41 at the same time as forming the antioxidant film on the molding surface 21 as in the above-described embodiment.

  In the above-described embodiment, the same coating film 33 as the coating film 33 before the mold 11 regeneration is formed to regenerate the mold. However, the present invention is not limited to this, and coating of different materials and layer structures before and after the regeneration. A film may be provided.

  In the above-described embodiment, the antioxidant film formed on the molding surface 21 is used as a reproduction coating film. However, the present invention is not limited to this, and a film having a material or layer structure different from that of the coating film 33 provided on the molding surface 21. May be formed on the side surface 41 of the upper mold 42 as a recycling coating film to regenerate the mold. However, in the step of forming the coating film 33 on the molding surface 21, the dimensions of the mold can be adjusted at the same time, so that the coating film 33 (or the coating film 33) provided on the molding surface 21 as in the above-described embodiment. It is preferable that a part of the layer is a coating film for regeneration.

It is sectional drawing which shows the structure of a metal mold | die roughly. It is sectional drawing which shows roughly a mode that a lower mold | type structure, and a lower mold | type wear. It is sectional drawing which shows the procedure which reproduces | regenerates the worn lower mold | type.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Mold 12 Preform 15 Core 16 Body type | mold 17,42 Upper mold | type 18 Lower mold | type 21,22 Molding surface 31 Base material 32 Cutting layer 33 Coating film 34 Temporary molding surface 37 Antioxidation film 38 Release film 41 Side surface (sliding) Moving surface)
43 Antioxidation film (recovery coating film)
45 Reproduction upper mold (regeneration mold)

Claims (16)

A method for regenerating a lens molding die comprising a pair of cores provided with a molding surface for molding an optical surface of a glass lens and having a coating film formed on at least the molding surface, and a barrel mold that slides on the core In
A coating film for regeneration that is the same as the coating film that regenerates the diameter after film formation to a predetermined dimension on at least one of the sliding surfaces on which the core and the body mold slide after the coating film is once removed. A method for reclaiming a mold, comprising regenerating the mold by forming a film.   The mold regeneration method according to claim 1, wherein the regeneration coating film is formed on the sliding surface of the core.   3. The mold regeneration method according to claim 1, wherein the coating film is formed on a sliding surface of the barrel mold.   3. The mold regeneration method according to claim 1, wherein the regeneration coating film is formed to a thickness that compensates for wear of the core.   4. The mold regeneration method according to claim 1, wherein the regeneration coating film is formed to a thickness that compensates for wear of the body mold.   4. The mold regeneration method according to claim 1, wherein the regeneration coating film is formed to a thickness that compensates for wear of the core and wear of the body mold.   The coating film is provided by laminating a plurality of layers having different purposes of use, and the regeneration coating film is composed of a film made of the same material as any one of the plurality of layers. The method for reclaiming a mold according to any one of claims 1 to 6, wherein:   The mold regeneration method according to any one of claims 1 to 7, wherein the regeneration coating film is made of titanium aluminum nitride. A lens molding die comprising a molding surface that molds an optical surface of a glass lens, a pair of cores having a coating film formed on at least the molding surface, and a barrel mold that slides on the core, In a reclaim mold that has been regenerated by forming a coating film,
For the same reproduction as the coating film, which is provided after the coating film is removed once, and which regenerates the diameter after film formation to a predetermined dimension on at least one of the sliding surfaces on which the core and the body mold slide. A regeneration mold comprising a coating film.   The regeneration mold according to claim 9, wherein the regeneration coating film is provided on a sliding surface of the core.   The regeneration mold according to claim 9 or 10, wherein the coating film is provided on a sliding surface of the body mold.   The regeneration mold according to claim 9 or 10, wherein the regeneration coating film is provided with a thickness that compensates for wear of the core.   The regeneration mold according to claim 9 or 11, wherein the regeneration coating film is provided with a thickness that compensates for wear of the body mold.   12. The regeneration mold according to claim 9, wherein the regeneration coating film is provided with a thickness that compensates for wear of the core and wear of the body mold.   The coating film is provided by laminating a plurality of layers having different purposes of use, and the regeneration coating film is composed of a film made of the same material as any one of the plurality of layers. The remanufacturing mold according to any one of claims 9 to 14, characterized in that:   The regeneration mold according to any one of claims 9 to 15, wherein the regeneration coating film is made of titanium aluminum nitride.

Images