JP2009203084A - Lens molding apparatus - Google Patents

Abstract

A lens molding apparatus capable of efficiently producing a high-precision molded lens using a single unit molding die composed of an upper mold, a lower mold, and a body mold.
A lens molding apparatus according to the present invention includes a lower mold 41 having transfer surfaces 41a and 42a for transferring an optical surface shape, and arranged such that the transfer surfaces 41a and 42a face each other on the same axis. An upper mold 42 is provided. A first body mold 43 having a through hole 43a in which a lower mold 41 and an upper mold 42 are inserted to form a molding space between the transfer surfaces 41a and 42a; a second body mold 48 including the first body mold 43; A body mold holder 49 that holds the second body mold 48, and a body mold slide mechanism 50 that allows the body mold holder 49 to move in the same direction as the opening and closing direction of the upper mold 42. The lens is molded in a state where the second body mold 48 is held by the body mold holder 49.
[Selection] Figure 3

Description

  The present invention relates to a lens molding apparatus that molds a glass or resin lens used for a camera-equipped mobile phone or various optical devices.

  Conventionally, press molding of a glass or resin lens is performed by using, for example, a molding die composed of an upper die, a lower die, and a barrel die, and an optical material is set in the molding die and the temperature is raised to a molding temperature. This is done by applying pressure. In this molding method, a molding lens is manufactured by sequentially circulating a plurality of molding molds to a plurality of stations such as a preform supply station, a molding station, and a molded lens take-out station. There is a method of feeding, molding, and taking out a preform by using a molding die of one unit installed on the upper and lower sides or a barrel mold at that position.

The former method is excellent in mass productivity and has an advantage that a lens can be manufactured at a low cost. However, since a plurality of molding dies are used, individual differences are likely to occur, and it is not suitable for molding a lens that requires high accuracy. In addition, as is known from Patent Document 1, a station for taking out a molded lens, and a station in which a preform is installed on a lower mold and combined with the upper mold and the barrel mold are required. In the latter method, since only one unit mold is used, high-precision lens molding without individual differences is possible. However, the molded lens can be taken out and the upper mold, lower mold and body mold can be combined. In particular, when applying a mold structure in which the upper and lower molds are positioned by abutting the molds on both end faces of the second body mold as described in Patent Document 2, after molding, The robot arm needs a complicated mechanism for disassembling the mold assembly, such as holding the barrel mold, separating it from the mold and placing it in a predetermined place, and then taking out the lens, and it takes a long tact time.
JP 2006-036592 A JP 2002-029763 A

  However, if the lower mold is simply lowered as in Patent Document 1 when the molded lens is taken out, the molded lens may bite into the inner wall of the barrel mold and remain inside the barrel mold. To prevent the lens from remaining inside the barrel mold, it is effective to raise the upper mold and push the molded lens to the lower mold using air or a robot arm. However, the movement mechanism is required for both of them, the structure becomes complicated, and the tact time becomes long, so that it is not suitable for efficient production.

  The present invention has been made in view of the above circumstances, and an object thereof is to efficiently manufacture a high-precision molded lens using a single unit molding die including an upper die, a lower die, and a barrel die. Is to be able to.

  The lens molding apparatus according to the present invention receives the upper mold and the lower mold from above and below the through hole formed in the body mold, and applies the preform on the transfer surface formed on the opposing surface of the upper mold and the lower mold. Press to mold the lens. A barrel mold holder that holds the barrel mold and moves the barrel mold in the direction of the central axis of the through hole, and a molded lens that remains in the lower mold after the upper mold is retracted upward from the barrel mold after molding And a body-type slide mechanism that moves the body-type holder upward so that it is exposed.

  The trunk mold includes a first trunk mold in which the through hole is formed, and a cylindrical second trunk mold that is held so as to wrap around the first trunk mold and is held by the trunk mold holder. The two-body mold is made of a material having a larger coefficient of thermal expansion than the first cylinder mold, and a positioning surface formed integrally with the upper mold and the lower mold is brought into contact with each end face of the second cylinder mold. The upper mold and the lower mold are positioned.

  In the lens molding apparatus according to the present invention, since the body mold is always connected to the body mold holder, the body mold rises only by raising the body mold holder, so that the operation of gripping the body mold by the robot arm is unnecessary. Is easy and the tact time can be shortened. In addition, the thermal expansion coefficient of the second barrel mold is made larger than that of the first barrel mold, and cooling is started after the upper mold and the lower mold are brought into contact with both end faces of the second trunk mold. In addition to improving accuracy and parallel accuracy of the front and back surfaces, it is possible to stably form a lens having high surface accuracy without applying excessive pressure to the lens during cooling.

  As shown in FIG. 1, the lens manufacturing system 15 includes a chamber 11 in which a lens molding device is housed, an accumulation shelf 12, a temporary table 13, and a supply accumulation robot 14. The stacking shelf 12 includes a plurality of shelves, the upper tray includes a preform tray 17 on which a preform 16 which is a glass material before molding is placed, and the lower tray includes a molded lens 18. A lens stacking tray 19 is placed. The temporary table 13 installed between the chamber 11 and the stacking shelf 12 includes a preheating unit 13 a that preheats the preform 16 and a heat removal unit 13 b that removes heat from the molded lens 18.

  The supply and accumulation robot 14 includes a columnar member 21 that moves back and forth with respect to the chamber 11, a beam member 22 that is attached to the columnar member 21 and is movable up and down, and is provided on the beam member 22 along the beam member 22. And an arm part 23 that is movable to the left and right. The arm portion 23 is provided with a suction port 24 that sucks and moves the preform 16 and the lens 18 at the tip thereof.

  The chamber 11 is provided with an opening 26 through which the arm portion 23 enters and exits in the front outer wall surface 11a, and the arm portion 23 is moved in and out by a shutter plate 28 of a shutter device 27 provided in the outer wall surface 11a. Closed. When the shutter plate 28 is closed, the inside of the chamber 11 is filled with an inert gas and oxygen does not enter from the outside of the chamber 11, so that oxidation of the mold can be prevented.

  As shown in FIG. 2, the lens molding apparatus 10 provided in the chamber 11 is provided at the tip of a lower die 31 and a barrel die 40 including a first barrel die 43 and a second barrel die 48. A lower die 41 and an upper die 42 provided at the tip of the upper rod 32. The lower mold 41 and the upper mold 42 have transfer surfaces 41a and 42a for transferring the optical surface shape, and are arranged so that the transfer surfaces 41a and 42a face each other on the same axis. The lower mold 41 and the upper mold 42 are fitted into the through holes 43 a of the first body mold 43 to form a molding space 44 in which the lens 18 is formed. The lower rod 31 and the upper rod 32 are respectively provided with heaters 46 and 47 that heat the upper rod 32, and the heater 47 that heats the upper rod 32 moves up and down together with the upper rod 32.

  As shown in FIG. 3, the trunk mold 40 includes a second trunk mold 48 outside the first trunk mold 43. The first body mold 43 includes a through hole 43a in which the lower mold 41 and the upper mold 42 are closely fitted, and the through hole 43a is processed with high accuracy so that the centers of the lower mold 41 and the upper mold 42 coincide. The lower die 41 and the upper die 42 completely enter the second barrel die 48, and the shoulder portions (positioning surfaces) 31 a and 32 a of the lower rod 31 and the upper rod 32 abut against the second barrel die 48, and the second barrel die 48. Pinch. As a result, the positions of the lower mold 41 and the upper mold 42 are determined, and the interval between the transfer surfaces 41a and 42a is determined. The thermal expansion coefficient of the second body mold 48 is larger than that of the first body mold 43.

  The second body mold 48 is held by a body mold holder 49, and the body mold holder 49 is attached to the body mold slide mechanism 50. The body-type slide mechanism 50 is movable in the same vertical direction as the opening / closing direction of the upper mold 42, whereby the first body mold 43 and the second body mold 48 are moved in the same direction as the opening / closing direction of the upper mold 42. It is possible. The barrel holder 49 holds the second barrel die 48 even during molding.

  The torso-type slide mechanism 50 includes a fixed portion 52 attached to the inner wall surface 11b on the right side surface of the chamber 11, and a movable portion 53 that is slidably fitted to the fixed portion 52 and moves up and down. The barrel-type holder 49 is attached. The body-type slide mechanism 50 is an apparatus in which, for example, a fixed part 52 includes a pinion gear that is rotated by a driving device such as a motor, and a movable part is provided with a rack gear. Alternatively, a ball screw may be provided instead of the pinion gear, and a nut may be provided instead of the rack gear. Alternatively, a method of sliding the movable part with an electric cylinder may be used.

  Next, the operation of the lens molding apparatus 10 having the above configuration will be described. Returning to FIG. 1, the supply and accumulation robot 20 moves the columnar member 21 and the beam member 22, inserts the arm portion 23 into the upper stage of the accumulation shelf 12, and removes the preform 16 from the preform tray 17 placed there. One is adsorbed by the suction port 24 by sucking air. The adsorbed preform 16 is placed on the preheating part 13a of the temporary table 13, and heated to a predetermined temperature.

  As shown in FIG. 4, with the upper mold 42 retracted upward, the trunk mold holder 49 is lowered and the through hole 43 a of the first trunk mold 43 is fitted with the lower mold 41. At this time, since the lower mold 41 is supported by the copying mechanism, alignment is performed by being guided by the through hole 43a.

  When the shutter plate 28 is raised and the opening 26 is opened, the arm portion 23 adsorbs the preform 16 to the suction port 24 provided at the tip thereof, enters the chamber 11 through the opening 26, and moves into the chamber 11. The reform 16 is placed on the transfer surface 41 a of the lower mold 41. When the preform 16 is set, the arm portion 23 is retracted from the chamber 11, the shutter plate 28 is lowered by the air cylinder 29, and the opening 26 is closed. Subsequently, the upper mold 42 is lowered and fitted into the through-hole 43a, and the preform 16 is pressed between the transfer surface 41a of the lower mold 41 and the transfer surface 42a of the upper mold 42 to mold the lens 18. At this time, since the upper mold 42 is supported by the copying mechanism, the upper mold 42 is guided to the through-hole 43a and alignment is performed.

  After the pressure molding, the lower mold 41, the upper mold 42, and the body mold 40 are removed from heat while maintaining the pressure, so that the molded lens 18 contracts with cooling. At this time, since the second body mold 48 is also contracted, the distance between the lower mold 41 and the upper mold 42 is reduced accordingly. However, since the contraction of the second body mold 48 is large, the mold shape can be continuously transferred to the lens until the cooling is completed. When the heat removal is completed, the upper mold 42 rises again and waits upward.

  On the other hand, while the lens molding apparatus 10 is molding the lens 18, the supply and accumulation robot 20 performs an operation of placing the next preform 16 on the preheating portion 13 a of the temporary table 13. 16 is heated to a predetermined temperature.

  As shown in FIG. 5, when the lens 18 is molded and the upper mold 42 rises and waits upward, the air cylinder 29 moves the shutter plate 28 upward to open the opening 26. When the opening 26 is opened, the arm portion 23 enters the chamber 11 through the opening 26. The arm portion 23 presses the lens 18 formed by inserting the suction port 24 into the center of the first body mold 43. In this state, the movable portion 53 of the trunk slide mechanism 50 is driven slightly upward to move the trunk holder 49. The first body mold 43 is moved by the movement of the body mold holder 49, and the circumferential surface (edge surface) of the lens 18 is peeled from the first body mold 43 (see FIG. 5).

  As shown in FIG. 6, the supply and accumulation robot 20 once moves the arm portion 23 to a position that does not hinder the rise of the barrel holder 49. Thereafter, when the body holder 49 holding the first body mold 43 is raised by the body mold slide mechanism 50, the supply and accumulation robot 20 moves the arm portion 23 to the position directly above the lens 18 and sucks it. The lens 18 is adsorbed by the mouth 24, and the arm portion 23 is pulled out from the chamber 11 while adsorbing the lens 18, and the lens 18 is placed on the heat removal unit 13 b of the temporary table 13. When the lens 18 is placed on the heat removal unit 13 b of the temporary table 13, the sucked air is stopped, but air may be blown in order to reliably separate the lens 18 from the suction port 24.

  The first body mold 43 is lowered by the body mold slide mechanism 50 and is fitted to the lower mold 41 to prepare for receiving the preform 16. The arm portion 23 sucks the next preform 16 placed on the preheating portion 13 a of the temporary table 13 through the suction port 24, enters the chamber 11 through the opening 26, and moves the preform 16 to the transfer surface of the lower mold 41. 41a. When the preform 16 is set on the transfer surface 41a, the arm portion 23 is retracted from the chamber 11, and the shutter plate 28 closes the opening 26. In the lens molding apparatus 10, the upper mold 42 is lowered and the lens 18 is molded as described above.

  The arm unit 23 sucks the lens 18 placed on the heat removal unit 13b of the temporary table 13 through the suction port 24, and conveys the lens 18 to the lens stacking tray 19 placed on the lower stage of the stacking shelf 12. The supply and accumulation robot 20 moves the suction port 24 directly above the lens receiving portion 19 a (see FIG. 1) of the lens accumulation tray 19, stops the air, and places the lens 18 on the lens accumulation tray 19. Thereafter, the arm portion 23 is moved to the upper stage of the stacking shelf 12, and one of the preforms 16 is sucked by the suction port 24 from the preform tray 17 placed there, and the preform 16 is heated by the preheating portion of the temporary table 13. 13a. Thereafter, the above molding procedure is repeated, and the preform 16 is sequentially molded into the lens 18.

  The lens stacking tray 19 is transported to the next step when the lens 18 is placed on all of the lens receiving portions 19a provided therein.

  In the above-described embodiment, the body mold is constituted by the first body mold 43 and the second body mold 48. However, the second body mold 48 is not necessarily required, and the body mold holder 49 directly holds the first body mold 43. It is good also as a structure.

  Even if the supply and integration robot 14 has a structure different from that of the embodiment, there is no problem in the lens molding apparatus 10 according to the present invention, and even if a temporary table is not used, there is no problem. Absent.

1 is a perspective view showing an overall configuration of a lens manufacturing system in which a lens molding apparatus according to the present invention is installed. It is a partial cross section figure for demonstrating a shutter apparatus and a lens shaping | molding apparatus. It is a perspective view which shows the structure of a trunk | drum type | mold slide mechanism. It is a partial cross section figure of the chamber for demonstrating the shaping | molding procedure of a lens. It is a partial sectional view of a chamber for explaining movement of a body mold at the time of lens fabrication. It is a partial cross section figure of the chamber for demonstrating the procedure after lens shaping | molding.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens shaping | molding apparatus 11 Chamber 11a Outer wall surface 11b Inner wall surface 14 Supply integrated robot 15 Lens manufacturing system 16 Preform 17 Preform tray 18 Lens 19 Lens integrated tray 23 Arm part 24 Adsorption port 26 Opening 27 Shutter device 28 Shutter plate 31 Lower rod 32 Upper rod 31a, 32a Shoulder (positioning surface)
40 body mold 41 lower mold 41a, 42a transfer surface 42 upper mold 43 first body mold 44 molding space 48 second body mold 49 body mold holder 50 body mold slide mechanism 52 fixed section 53 movable section

Claims (3)

Lens molding for receiving an upper mold and a lower mold from above and below the through-hole formed in the body mold, and molding a lens by pressing a preform with a transfer surface formed on the facing surface of the upper mold and the lower mold. In the device
A barrel holder that holds the barrel mold and moves the barrel mold in the direction of the central axis of the through hole; and
A cylinder-type slide mechanism that moves the cylinder-type holder upward so that the molded lens remaining in the lower mold is exposed after the upper mold is retracted upward from the cylinder mold after molding;
A lens molding apparatus comprising:   The trunk mold includes a first trunk mold in which the through hole is formed, and a cylindrical second trunk mold that is held so as to wrap around the first trunk mold and is held by the trunk mold holder. The lens molding apparatus according to claim 1. The second body mold is made of a material having a larger coefficient of thermal expansion than the first body mold, and a positioning surface formed integrally with the upper mold and the lower mold is applied to each end surface of the second cylinder mold. 3. The lens molding apparatus according to claim 2, wherein the upper mold and the lower mold are positioned in contact with each other.

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