WO2009131168A1 - Press forming device for optical element - Google Patents

Abstract

A press forming device for an optical element for forming an optical element by pressing a glass material between a plurality of upper dies and a plurality of lower dies forming pairs with the upper dies, the device comprising a means for imparting a pressure to the plurality of lower dies, a body mold into which the plurality of pairs of upper dies are inserted from above and the plurality of pairs of lower dies are inserted from below and which guides the relative position of the upper and lower dies, a pressure generating means for pressing the body mold upward, and an upper die pressure distribution means for pressing each upper die downward as the body mold is moved upward by a pressing force generated by the pressure generation means and applying a pressure independently to each upper die, characterized in that the upper die pressure distribution means; comprises an upper cylinder receiving a load by a pressure acting on an upper die, and an upper rocking member arranged to be able to rock on a fulcrum and having one end abutting on the upper end of the upper die and the other end coupled with the upper cylinder; regulates a pressure being applied from the upper cylinder to each upper die through the upper rocking member in a process for moving the body mold upward by the pressure generation means; and presses the lower die upward by the means for imparting a pressure to the lower dies.

Description

Optical element press molding equipment

The present invention relates to an optical element press molding apparatus, and more particularly to an optical element press molding apparatus used for press molding a highly accurate optical element such as an aspheric lens.

In recent years, attention has been paid to a precision press molding method in which an optical glass element such as a glass lens is press-molded and used as it is without polishing the molding surface. Usually, this type of molding uses a molding die (upper die, lower die) that slides against the barrel die within the barrel die, and the glass material in a softened state is placed between the upper die and the lower die. An optical element press molding apparatus is used that is pressed to form an optical functional surface corresponding to the molding surface of a mold on a glass material. What is important here is that, when the product is relatively small, if a single press molding machine is used to mold with a set of molds, the productivity is low. Therefore, a method has been proposed in which a plurality of dies are mounted on a single press molding machine and a plurality of optical elements are produced simultaneously (see Japanese Patent No. 2815037).

When pressurizing a plurality of molds simultaneously, it is necessary to devise to obtain an optical element with high molding accuracy. As this method, the first method is to press a plurality of molds using a pressing member such as a flat plate fixed to a single pressing shaft perpendicular to the sliding direction of the mold. With this method, the strokes of all the molds are determined based on the mold having the shortest stroke among a plurality of molds. For this reason, in order to mold optical elements that require wall thickness and surface tilt accuracy in units of microns, the dimensions of each mold, the dimensions of the pressing member, and the pressing member so that all strokes are within the standard. It is necessary to fully manage the mounting and pressurization inclination, the wear of the contact part with the pressing member mold, and the deformation, but it is almost impossible to control under the molding conditions of several hundred degrees Celsius, including the deformation of the molding machine. Close to. Therefore, it is necessary to apply the upper die, which is a molding die, to the barrel die, and to guarantee the accuracy as described above with the accuracy of the upper die, the barrel die, and other component members.

However, in the pressurizing method as described above, since the stroke is the same for all the molds, it is almost impossible to always push all the molds for the same reason as described above. A method of applying pressure with a certain degree of freedom so as to follow the stroke without fixing the pressing member is also conceivable. However, when simultaneously pressing a plurality of dies, particularly four or more dies. If all the mold heights are not on the same plane, all the molds cannot be pushed.

In addition, the pressing start position and the molding speed (glass deformation speed) differ between molds due to variations in the dimensions of the molding material and subtle temperature differences between the molds during pressing. Frequently, the member is pressurized while being tilted with respect to the sliding direction of the mold. For this reason, the pressing force acts in directions other than the sliding direction of the mold, and the mold tends to be galled or damaged. Further, the contact portion between the mold and the pressing member is always rubbed and easily worn. In this state, the wear becomes intense, and as a result of the wear, a vicious circle is repeated in which mold galling and breakage are further promoted.

In the above molding apparatus, it is necessary to heat and cool the body mold, the upper mold, and the lower mold at a considerably high and low temperature difference in order to control the temperature of the glass material in the press molding process. Therefore, the body mold, the upper mold, and the lower mold are made of materials having substantially the same thermal expansion coefficient, and a clearance is provided to ensure sliding of the upper mold and the lower mold with respect to the cylinder mold.

For this reason, for example, when a glass material is pressed between the lower mold by lowering the upper mold, if the pressing pressure is not applied to the center of the upper mold, the upper mold is slid in the barrel mold. The glass material cannot be press-molded in a state where the molding surfaces of the upper mold and the lower mold correspond to each other correctly. Further, in an extreme case, galling occurs between the body mold and the upper mold, and the upper mold cannot be completely closed with respect to the body mold, and normal pressing cannot be performed. In other words, as a result, the center of the optical function surface of the molded optical element does not coincide with the optical axis. Also, when pulling up the upper mold to remove the molded product from the mold, if the lifting force is off the center of the upper mold, the upper mold is tilted and the upper mold and the upper mold are galling, and the upper mold is opened and closed. Can not be. In such a molding apparatus, the clearance of the sliding part between the body mold and the upper mold is as small as 10 μm or less under the conditions of actual use. The environment is prone to occur.

There is a molding apparatus described in Japanese Patent No. 2815037 as an example in which the above-mentioned drawbacks of the prior art are solved to some extent. In the molding apparatus disclosed in Japanese Patent No. 2815037, even if the die height during pressurization is different by stacking and arranging a plurality of disc springs between a press shaft that applies press pressure to the upper die and the upper die. By absorbing the difference in height by the deformation of the disc spring, the pressing pressure is uniformly applied to each die.

However, the molding apparatus disclosed in Japanese Patent No. 2815037 has a problem that the disc spring is exposed to a high temperature and sags because the disc spring is located near the upper die.

Also, in order to make up for this drawback, it is necessary to cool the disc spring part with water, but a new problem arises that the member becomes larger and complicated due to water cooling.

Furthermore, since the water-cooled member contacts the upper mold at the time of molding, there is also a drawback that the temperature of the upper mold rapidly decreases and the temperature of the molded glass becomes unstable.

Also, since multiple upper molds and lower molds are set in one body mold for the purpose of cost reduction, it is economically impossible to increase the distance between each mold set. For this reason, the distance between each set of molds is usually a few tens of millimeters at most, and it is necessary to provide a disc spring on each of the shafts corresponding to this distance. Usually, the pressure required for press molding of glass is around 4.9 kN with a φ18 mold, so the strength of the spring used for the disc spring needs to be 4.9 kN or more. There is usually no 4.9 kN wound spring that fits in a space of a few dozen millimeters.

Therefore, in Japanese Patent No. 2815037, a disc spring is used. However, if the disc spring has a capacity of 4.9 kN in a narrow space, it is necessary to stack a plurality of disc springs in large quantities. There is a problem that the length of the molding apparatus becomes very long and the molding apparatus becomes large.

Also, if the size of the lens to be pressed changes from the original schedule and the press pressure needs to be changed significantly, it is necessary to change the spring constant by replacing the disc spring. It takes a lot of labor and labor to disassemble the parts and replace the disc spring inside. Thus, the molding apparatus disclosed in Japanese Patent No. 2815037 still has the above-described problems.

In Japanese Patent No. 2815037, there is no description of pressure distribution when the lower die slides and presses within the body die, and it is assumed that the mechanism does not perform pressure distribution when pressing with the lower die.

In view of the above circumstances, an object of the present invention is to provide an optical element press molding apparatus that solves the above-described problems.

In the first embodiment of the present invention, an optical element press molding apparatus for molding an optical element by pressing a glass material between a plurality of upper molds and a plurality of lower molds paired with the upper mold, Lower mold pressure applying means for applying pressure to a plurality of lower molds, the plurality of pairs of upper molds are inserted from above, the plurality of pairs of lower molds are inserted from below, and the relative positions of the upper mold and the lower molds A cylinder mold for guiding the cylinder mold, pressure generating means for pressing the cylinder mold upward, and pressing the upper molds downward as the cylinder mold is moved upward by the pressing force of the pressure generating means. And an upper mold pressure distribution means for applying pressure to each upper mold independently, the upper mold pressure distribution means comprising an upper cylinder for receiving a load due to pressure acting on the upper mold, and a fulcrum And one end is in contact with the upper end of the upper mold. An upper swinging member having the other end connected to the upper cylinder, and in the process of moving the barrel mold upward by the pressure generating means, the upper swinging member is attached to each upper mold via the upper swinging member. The above problem is solved by adjusting the pressure and pressing the lower mold upward by the lower mold pressure applying means.
In the second embodiment of the present invention, the press molding apparatus according to the first embodiment includes a housing that accommodates at least the upper mold, the lower mold, and the body mold, and the upper cylinder and the The upper swinging member is disposed on the upper surface of the casing, thereby solving the above-described problem.
In the third embodiment of the present invention, in the press molding apparatus according to the first or second embodiment, the lower mold pressure applying means moves the barrel mold upward by a pressing force by the pressure generating means. Accordingly, the above problems are solved by pressing the plurality of lower molds upward.
In the fourth embodiment of the present invention, the press molding apparatus according to the third embodiment includes a lower cylinder that receives a load due to pressure acting on the lower mold, and a lower cylinder pressure applying means via a fulcrum. A lower swinging member disposed at one end in contact with the lower end of the lower mold and connected at the other end to the lower cylinder. The lower swinging member is centered on the fulcrum. The above-mentioned problem is solved by adjusting the pressure applied to each lower mold by the lower cylinder by swinging in the vertical direction.
5th Embodiment of this invention WHEREIN: The said press molding apparatus in the said any one of the 1st thru | or 4th embodiment is a process with respect to the said cylinder mold in the process of moving up the said cylinder mold with the pressing force by the said pressure generation means. A plurality of alignment means for aligning the position of the upper mold, and each of the plurality of alignment means is configured to press the upper mold with respect to the movement axis of the upper mold when the upper mold is pressed upward. A spherical bearing capable of rotating the upper mold so as to coincide with the axis, and an upper mold support member formed so as to support the outer side of the spherical bearing and separating the spherical bearing by the upward pressing operation; By solving this problem, the above-described problems are solved.
In the sixth embodiment of the present invention, in the press molding apparatus according to any one of the first to fifth embodiments, the upper mold pressure distribution means connects the fulcrum to the longitudinal direction of the upper swing member. The position is variable, and the above-described problem is solved by adjusting the pressure acting on the upper mold according to the ratio between the connection position of the fulcrum and the total length of the upper swing member.
In the seventh embodiment of the present invention, in the press molding apparatus according to the fourth embodiment, the lower mold pressure applying means can change the connecting position of the fulcrum with respect to the longitudinal direction of the lower swing member. The above-described problem is solved by adjusting the pressure acting on the lower mold according to the ratio between the connection position of the fulcrum and the total length of the lower swing member.
In the eighth embodiment of the present invention, in the press molding apparatus according to any one of the first to fifth embodiments, the upper die pressure distribution means can change a filling pressure in the upper cylinder, The above problem is solved by adjusting the pressure acting on the upper mold by the filling pressure.
In the ninth embodiment of the present invention, in the press molding apparatus according to the fourth embodiment, the lower mold pressure applying means can change a filling pressure in the lower cylinder, and the lower pressure is changed by the filling pressure. The said subject is solved by adjusting the pressure which acts on a type | mold.
In the tenth embodiment of the present invention, in the press molding apparatus according to any one of the first, second, and eighth embodiments, the upper cylinder is an air cylinder filled with a gas of a predetermined pressure. The problem is solved by being.
In the eleventh embodiment of the present invention, in the press molding apparatus according to the fourth or ninth embodiment, the lower cylinder is an air cylinder filled with a gas having a predetermined pressure. To solve.
In a twelfth embodiment of the present invention, the press molding apparatus according to any one of the first to eleventh embodiments is inserted between the upper mold and the lower mold before pressing, and the lower side A centering member that centers the position of the glass material placed on the center of the lower mold from both sides, and the centering member lowers the body mold after pressing the glass material to form an optical element. At the same time, the above-mentioned problem is solved by pressing the peripheral edge of the optical element downward.
In a thirteenth embodiment of the present invention, the press molding apparatus according to any one of the first to twelfth embodiments moves the inside of the casing to move the glass material into the lower mold in the barrel mold. A suction hand that is placed on the molding surface and takes out the pressed optical element from the barrel mold, a hand holding mechanism that holds the suction hand in a horizontal state, and the suction hand is driven via the hand holding mechanism The hand holding mechanism solves the above-described problem by holding the suction hand by a plurality of elastic rubber members.
In the fourteenth embodiment of the present invention, the press molding apparatus according to any one of the first to twelfth embodiments moves the inside of the casing to move the glass material into the lower mold in the barrel mold. A suction hand that is placed on the molding surface and takes out the pressed optical element from the barrel mold, a hand holding mechanism that holds the suction hand in a horizontal state, and the suction hand is driven via the hand holding mechanism And the hand holding mechanism is guided in a vertical direction by a linear guide to solve the above-described problem.

According to the present invention, the pressure on each upper mold by the upper cylinder is adjusted via the upper swing member in the process of moving the barrel mold upward by the pressure generating means, and the lower mold is pressed upward by the lower mold pressure applying means. Therefore, it is possible to reduce the pressure acting on the upper cylinder by reducing the pressure acting on the upper cylinder as compared with the conventional one in which a plurality of disc springs are stacked, and to reduce the size of the upper cylinder, and to eliminate the need for a cooling mechanism for water cooling. No measures are taken to prevent corrosion of the mold in case of leakage.

In addition, by adjusting the pressure of the upper cylinder, it is possible to easily cope with changes in the applied pressure with respect to the upper die, and the pressure is higher than in the case where the number of disc springs is changed as in the prior art. Easy to change.

Further, since there is an insulator means for transmitting the pressure of the upper die to the cylinder via a swinging member that swings around a fulcrum, the barrel die having a plurality of guide holes is slid with respect to the plurality of upper molds. When operating and press-molding glass material, all upper molds can be pushed completely, and due to variations in the dimensions of the molding material, subtle temperature differences between the molds during pressing, etc. Even if the pressure start position and molding speed (glass deformation speed) differ between the molds, it can be easily adjusted to cope with these, so the accuracy of the molded product is improved and productivity is improved. Many effects can be obtained.

According to the optical element press molding apparatus according to the present invention, since the aligning means is provided, when simultaneously performing press molding with a plurality of upper molds and lower molds, a force applied to the upper mold is always applied to each upper mold Can be made to act toward the center of the axis of movement of the body mold when pushing up the body mold, there is no trouble such as galling, and the optical function surface is accurately positioned with respect to the optical axis. Therefore, it is possible to efficiently manufacture a highly accurate optical element.

It is a figure which shows the whole structure of the press molding apparatus of this Embodiment. 3 is a block diagram showing a configuration of a control system of the press forming apparatus 10. FIG. FIG. 19 is a diagram showing procedures 1 to 19 of each step performed in the press molding apparatus 10. FIG. 3 is a diagram showing procedures 20 to 32 of each step performed in the press molding apparatus 10. 2 is a longitudinal sectional view showing the configuration of a molding die unit 40, an alignment means 90, and an upper mold pressure distribution means 100. FIG. It is the figure which looked at the internal structure of the molding space 42c of the trunk | drum 42 from upper direction. 4 is an enlarged longitudinal sectional view showing the configuration of the alignment means 90. FIG. It is a longitudinal cross-sectional view which shows the press molding state which the cylinder mold moved up. 3 is a perspective view showing a configuration of an in-furnace hand mechanism 50. FIG. It is a side view which shows the horizontal holding mechanism 56 of the in-furnace hand mechanism 50. It is a figure which shows the suction piping path | route connected to each suction pad 53. FIG. It is a front view which expands and shows the structure of the lower mold | type pressure provision means 370. FIG. 4 is a plan view showing a state before the operation of the centering / scraper mechanism 60. FIG. It is a side view which shows the state before operation | movement of the centering scraper mechanism 60. FIG. FIG. 6 is a plan view showing a state in which the centering / scraper mechanism 60 is operating. It is a side view which shows the state in operation | movement of the centering scraper mechanism. 5 is a plan view showing a centering operation of the centering / scraper mechanism 60. FIG. It is a longitudinal cross-sectional view which expands and shows the state of the glass raw material before the centering operation | movement of the centering / scraper mechanism 60. FIG. It is a longitudinal cross-sectional view which expands and shows the state of the glass raw material after the centering operation | movement of the centering / scraper mechanism 60. 4 is a plan view showing a state before the operation of the heater unit 70. FIG. FIG. 6 is a plan view showing a state in which the heater unit 70 is operating. It is a longitudinal cross-sectional view which expands and shows the state which heats a glass raw material with the heater unit. It is a longitudinal cross-sectional view which expands and shows the state which press-molds the heated glass raw material. It is a longitudinal cross-sectional view which expands and shows the state which inserted the insertion lever 700 of the centering scraper mechanism 60 above the glass raw material. FIG. 6 is an enlarged longitudinal sectional view showing a state in which a glass material is separated from an upper mold 46 by lowering an insertion lever 700 of the centering / scraper mechanism 60. 6 is a longitudinal sectional view showing a modification of the upper die pressure distribution means 100. FIG. It is a side view which shows the modification 1 of the adsorption | suction hand 52 of the in-furnace hand mechanism 50. FIG. It is a top view which shows the modification 1 of the adsorption | suction hand 52 of the in-furnace hand mechanism 50. FIG. It is a side view which shows the modification 2 of the adsorption | suction hand 52 of the in-furnace hand mechanism 50. FIG. It is a top view which shows the modification 2 of the adsorption | suction hand 52 of the in-furnace hand mechanism 50. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating an overall configuration of a press molding apparatus according to an embodiment. As shown in FIG. 1, a press molding apparatus 10 includes a vacuum chamber (housing) 20 for molding an optical element, a stocker chamber for supplying a glass material to the vacuum chamber 20 and taking out the molded optical element. 30.

The vacuum chamber 20 includes a molding die unit 40, an in-furnace hand mechanism 50 for taking in a glass material and taking out the molded optical element, centering of the glass material carried in the molding die unit 40, and an optical element. A centering and scraper mechanism 60 for separating the glass material from the upper mold and a heater unit 70 for heating the glass material before molding.

The vacuum chamber 20 is supported by the vacuum chamber base 22, and the vacuum chamber base 22 includes pressure generating means 80 that presses the body mold 42 and the lower mold 44 of the molding die unit 40 upward, and an upper mold. An aligning means 90 for aligning the axis and an upper mold pressure distributing means (upper mold pressure adjusting mechanism) 100 for distributing the pressure of the upper mold 46 at the time of molding are provided.

The pressure generating means 80 has a booster cylinder 81 supported by a support base 82 fixed to the lower surface of the vacuum chamber 20. A lifting drive shaft 84 that moves up and down by the pressure of the booster cylinder 81 is connected to a lifting base 43 that supports the body mold 42 via a support member 85, and a lower mold pressure applying means 370 is mounted on the lifting base 43. ing.

The stocker chamber 30 also includes a pallet table 110 on which a glass material is placed, a SCARA robot 120 that sucks and transfers the glass material on the pallet table 110, and a glass material and an optical element for loading and unloading. It has a replacement chamber 130, a shifter moving means 150 that moves the shifter 140 of the replacement chamber 130, and a gate valve 160 that opens and closes the communication path 132 that communicates between the replacement chamber 130 and the vacuum chamber 20. Further, a vacuum pump unit 170 is provided below the stocker chamber frame 32 that supports the stocker chamber 30, and a filter unit 180 that supplies clean air to the stocker chamber 30 is provided on the upper surface of the stocker chamber 30. Yes.

The vacuum chamber 20 is connected to an air pipe 190 for supplying high-pressure air, a nitrogen pipe 200 for supplying nitrogen gas, a cooling nitrogen pipe 210, and a vacuum pipe 220 for sucking air by vacuum, and is connected to a stocker. An air pipe 190 and a vacuum pipe 220 for supplying high-pressure air are connected to the chamber 30.

And, in the air pipe 190, solenoid valves V21 to V25 for controlling the supply of high-pressure air are arranged. The nitrogen pipe 200 is provided with an electromagnetic valve V14 that controls the supply of nitrogen gas, and the cooling nitrogen pipe 210 is provided with electromagnetic valves V19 and V20 that control the supply of cooling nitrogen. The vacuum piping 220 is provided with solenoid valves V1 to V9, V11 to V16, V18, and V26. The electromagnetic valve V10 is provided in a pipe line 136 that bypasses between the vacuum chamber 20 and the replacement chamber 130, and equalizes the pressure in the vacuum chamber 20 and the pressure in the replacement chamber 130 by opening the valve.

Further, exhaust solenoid valves V17 and V27 are connected to the side wall and the bottom of the vacuum chamber 20, respectively. Each of the solenoid valves V1 to V27 is formed of, for example, a normally closed two-port two-position valve that opens by excitation of a solenoid and closes by demagnetization of the solenoid.

Also, below the vacuum chamber 20, a lifter unit 250 that lifts the glass material carried into the vacuum chamber 20 and an adsorption control unit 260 that performs vacuum suction to the adsorption hand 52 of the in-furnace hand mechanism 50 are arranged. Has been.

The press molding apparatus 10 is configured to perform press molding by loading a glass material (glass blank) into the molding die unit 40 and pushing up the body die 42 by the pressure generating means 80. The press molding is preferably performed in an inert gas atmosphere by filling the inside of the vacuum chamber 20 having an airtight structure with an inert gas such as nitrogen gas.

FIG. 2 is a block diagram showing the configuration of the control system of the press molding apparatus 10. As shown in FIG. 2, the control device 300 of the press molding apparatus 10 includes the above-mentioned in-furnace hand mechanism 50, centering / scraper mechanism 60, heater unit 70, pressure generating means 80, upper mold pressure distributing means 100, SCARA robot. 120, the vacuum pump unit 170 and the high pressure air solenoid valves V21 to V25, the vacuum solenoid valves V1 to V16, V18 and V26, and the exhaust solenoid valves V17 and V27 are controlled.

In addition to the above, the control device 300 includes a high-pressure air supply unit 310, a gate valve opening / closing mechanism 320, a replacement chamber pressure adjustment unit 330, a chamber internal pressure adjustment unit 340, a nitrogen supply unit 350, a nitrogen cooling unit 360, a lower mold pressure. The giving means 370 is controlled.

The high-pressure air supply unit 310 has an air compressor and supplies high-pressure air to the air pipe 190. The gate valve opening / closing mechanism 320 includes an air cylinder 322 that drives the gate valve 160 to move up and open the communication passage 132 of the replacement chamber 130 when high-pressure air is supplied by opening the electromagnetic valve V21.

Further, the replacement chamber pressure adjusting unit 330 introduces the vacuum generated by the vacuum pump unit 170 by opening the electromagnetic valve V9 into the replacement chamber 130, and operates so that air does not enter the chamber 20 when the glass material is carried in. To do.

The nitrogen supply unit 350 supplies nitrogen gas into the chamber 20 by opening the electromagnetic valve V14 when the glass material is press-molded.

The nitrogen cooling unit 360 supplies low-temperature nitrogen gas that cools the upper mold and the lower mold of the molding mold unit 40 by opening the electromagnetic valves V19 and V20 when the glass material is press-molded.

The lower mold pressure applying means 370 is composed of a lower mold pressure adjusting mechanism that pressurizes each lower mold 44 upward when the body mold 42 is moved upward by the pressure generated by the pressure generating means 80 to perform press molding. As will be described later, the lower mold pressure applying means 370 has a lower lever means and a lower cylinder made of an air cylinder, and the air pressure is generated so as to generate pressurization corresponding to the pressure acting on the lower mold 44. Be controlled.

FIGS. 3A and 3B are diagrams showing the procedure of each process performed in the press molding apparatus 10. Here, a method of manufacturing an optical element will be described with reference to FIGS. 3A and 3B. In the last final process, the horizontal moving table 152 of the shifter moving means 150 moves to open the replacement chamber 130, and the shifter 140 is moved from the vacuum chamber 20 to the replacement chamber 130 by the air cylinder 154 of the shifter moving means 150. I am letting.

In the procedure 1 shown in FIG. 3A, the replacement chamber 130 is closed by the shifter moving means 150. Next, the vacuum pump unit 170 is started, and the electromagnetic valve V9 is opened to evacuate the vacuum chamber 20 through the replacement chamber 130.

In step 2, nitrogen gas is supplied into the vacuum chamber 20 that is evacuated by opening the solenoid valve V14. The gate valve 160 is closed to block between the replacement chamber 130 and the vacuum chamber 20.

In step 3, the pallet 112 on which a plurality of glass materials are placed is carried into the pallet stand 110 in the stocker chamber 30. This pallet loading may be performed simultaneously with the procedure 2.

In step 4, the SCARA robot 120 in the stocker chamber 30 is driven to move the vacuum chuck 122 onto the pallet 112, and the electromagnetic valve 11 is opened to adsorb the glass material on the pallet 112.

In step 5, the replacement chamber 130 is opened and the arm 124 of the SCARA robot 120 is turned to move the vacuum chuck 122 above the shifter 140 housed in the replacement chamber 130. Then, the electromagnetic valve V11 is closed to release the suction by the vacuum chuck 122, and the glass material is placed at predetermined positions (four locations in the present embodiment) on the shifter 140.

In step 6, the replacement chamber 130 is sealed, the solenoid valve V9 is opened, and the replacement chamber 130 is evacuated. Next, the solenoid valve V10 is opened to introduce nitrogen in the vacuum chamber 20 into the replacement chamber 130, to replace the replacement chamber 130 with nitrogen, and to equalize the pressure in the vacuum chamber 20 and the pressure in the replacement chamber 130. To do.

In step 7, the solenoid valve V21 is opened and the gate valve 160 is opened by supplying air pressure. Next, the horizontal moving table 152 and the air cylinder 154 of the shifter moving means 150 are operated to move the shifter 140 horizontally into the vacuum chamber 20.

In step 8, the in-furnace hand mechanism 50 is driven to move the suction hand 52 above the shifter 140. The suction hand 52 is provided with four suction pads, and simultaneously sucks the four glass materials on the shifter 140 by opening the electromagnetic valves V1 to V4. At this time, the lifter unit 250 is driven by opening the electromagnetic valve V25, and the shifter 140 is raised so that the glass material of the shifter 140 approaches the suction hand 52.

In step 9, the cylinder mold 42 is moved up by the pressure-increasing cylinder 81 of the pressure generating means 80, and the height position of the side opening of the cylinder mold 42 is adjusted to an optimum position for the suction hand 52 to be inserted. Further, when the suction hand 52 is inserted into the body mold 42, the glass material sucked on the lower surface side of the suction hand 52 is at a height position suitable for placing on the upper end of each lower mold. The height of the body mold 42 is adjusted.

In the procedure 10, the suction hands 52 of the in-furnace hand mechanism 50 inserted into the body mold 42 are closed by the electromagnetic valves V1 to V4 to release the suction to the four glass materials. Thereby, each glass material carried in by the suction hand 52 is placed on the lower mold 44 in the body mold 42. At this time, the upper mold 46 and the lower mold 44 are preheated to a temperature of about 10 ¹⁶ dPa · s, for example, in terms of glass viscosity.

In step 11, the suction hand 52 of the in-furnace hand mechanism 50 is returned to the shifter 140 side.

In step 12, the solenoid valves V15, V16, V26 are opened, and the centering / scraper mechanism 60 is inserted into the body mold 42 of the molding die unit 40 from the side and placed on the lower mold 44. The placement position of each glass material is centered on the center (on the axis) of the lower mold 44.

In step 13, the centering / scraper mechanism 60 is detached from the molding die unit 40.

In step 14, the electromagnetic valve V18 is opened, and the heater unit 70 whose heating temperature is set to 900 ° C. is inserted into the body mold 42 of the molding die unit 40 from the side, and the lower mold 44 is attached to the lower mold 44. The mounted glass material is heated. The body mold 42 is heated by another heating means, and the lower mold 44 and the upper mold 46 are indirectly heated by heat conduction from the body mold 42.

In step 15, when the viscosity of the glass material heated by the heater unit 70 becomes, for example, 10 ⁷ dPa · s, the heating by the heater unit 70 is stopped and the heater unit 70 is detached from the body mold of the molding die unit 40.

In step 16, the pressure-increasing cylinder 81 of the pressure generating means 80 is operated to raise the body mold 42 and the lower mold 44 of the molding die unit 40. Thereby, the glass material is pressed between the upper mold 46 and the lower mold 44. The upper mold 46 is supported by a spherical bearing of the alignment means 90 so as to be aligned with respect to the vertical axis.

In step 17, during the pressing step, the axis of the upper mold 46 is aligned by the spherical bearing of the aligning means 90 so that it matches the axis of the lower mold 44.

In step 18, the glass material is pressed between the lower mold 44 and the upper mold 46 for a predetermined time to be molded into an optical element (aspheric lens).

In step 19, the press pressure is transmitted to the upper air cylinder 104 via the upper lever means 102 of the upper die pressure distribution means 100, and a compression load acts on the air cylinder 104, and the upper pressure is increased by an increase in air pressure in the upper air cylinder 104. The pressure in the mold 46 is buffered. Further, the air pressure in the upper air cylinder 104 is controlled in accordance with the increase / decrease of the press pressure with respect to the upper mold 46 by switching the three-way valve V30. In addition, the press pressure of the booster cylinder 81 that presses the body mold 42 upward is controlled to be constant.

3B, the solenoid valves V19 and V20 are opened, cooling nitrogen is supplied to the lower mold 44 and the upper mold 46, and the optical element molded together with the lower mold 44 and the upper mold 46 is cooled.

In step 21, since the glass material contracts due to cooling and the pressure applied to the glass material is released, the lower cylinder 44 of the lower mold pressure applying unit 370 (see FIG. 10) is operated to slightly raise the lower mold 44. . Thereby, the shape of the optical element can be stabilized.

In step 22, the solenoid valves V15, V16, V26 are opened, and the centering / scraper mechanism 60 is inserted into the body mold 42 of the molding die unit 40 from the side. At this time, the insertion height position of the centering / scraper mechanism 60 is set above the peripheral edge of the optical element.

In step 23, when the temperature of the lower mold 44 and the upper mold 46 is lowered to a predetermined temperature, the lower cylinder 610 (see FIG. 10) of the lower mold pressure applying means 370 is operated to move the lower mold 44 of the mold unit 40 for molding. Lower.

In step 24, the booster cylinder 81 of the pressure generating means 80 is operated to lower the body mold 42 and the centering / scraper mechanism 60. Accordingly, the lower mold 44 is separated from the upper mold 46, and the optical element (molded product) attached to the upper mold 46 is separated from the upper mold 46 by the centering / scraper mechanism 60 and placed on the lower mold 44.

In step 25, the centering / scraper mechanism 60 is detached from the molding die unit 40.

In step 26, the suction hand 52 of the in-furnace hand mechanism 50 is inserted into the body mold 42 of the molding die unit 40, and the body mold 42 is moved up and down by the pressure-increasing cylinder 81 of the pressure generating means 80. The height position is adjusted to an optimal position for sucking the pressed optical element. Next, the electromagnetic valves V 1 to V 4 are opened, and the four optical elements that are press-molded are sucked to the suction pads 53 of the suction hand 52. Then, the suction hand 52 is moved to the shifter 140 side. When the electromagnetic valve 25 is opened, the lifter unit 250 is driven to bring the upper surface of the shifter 140 closer to the optical element sucked by the suction hand 52.

In step 27, the electromagnetic valves V1 to V4 are closed to release the adsorption to the four optical elements.
Accordingly, each optical element transferred by the suction hand 52 is placed on the shifter 140.

In step 28, the shifter 140 is slid by the air cylinder 154 of the shifter moving means 150 and returned to the replacement chamber 130, and the gate valve 160 is closed to block the communication path 132 between the replacement chamber 130 and the vacuum chamber 20. To do.

In step 29, the replacement chamber 130 is opened and air is introduced into the replacement chamber 130.

In step 30, the SCARA robot 120 is driven to move the vacuum chuck 122 above the shifter 140 in the replacement chamber 130, and the electromagnetic valve V11 is opened, so that the four optical elements (molded products) on the shifter 140 are opened. Adsorbed by the vacuum chuck 122.

In step 31, the SCARA robot 120 is driven to move the vacuum chuck 122 above the pallet 112, the electromagnetic valve V <b> 11 is closed to release the adsorption to each optical element, and each optical element is placed on the pallet 112. To do. This completes the press molding manufacturing process of the optical element by the press molding apparatus 10. In the press molding apparatus 10, it is possible to efficiently mass-produce optical elements by repeating the above steps 1 to 31.

Next, the structure of each part of the press molding apparatus 10 which press-molds an optical element as mentioned above is demonstrated.
[Configuration of Mold Unit 40 for Molding]
FIG. 4 is a longitudinal sectional view showing the configuration of the molding die unit 40, the alignment means 90, and the upper mold pressure distribution means 100. As shown in FIG. 4, the molding die unit 40 is configured to guide the lower die 44 and the upper die 46 by the body die 42. The body mold 42 has four lower guide holes 42a through which four lower molds 44 are inserted, and four upper guide holes 42b through which four upper molds 46 are inserted. Further, the body mold 42 is provided with a molding space 42c into which the upper end (lower molding part) 44a of the lower mold 44 and the lower end (upper molding part) 46a of the upper mold 46 are inserted at the center. The molding space 42c communicates with 42d that opens on the left and right side surfaces of the body mold 42. The suction hand 52 or the heater unit 70 of the in-furnace hand mechanism 50 is inserted from the left opening 42d, and the centering is performed from the right opening 42d. -The scraper mechanism 60 is inserted.

As shown in FIG. 5, the lower guide hole 42 a and the upper guide hole 42 b of the body mold 42 are arranged in parallel in the X and Y directions, and are arranged so as to be symmetrical in any direction from the axis. ing. As a result, the four lower molds 44 and the upper mold 46 each conduct heat uniformly generated during press molding, and variations in each mold due to temperature are suppressed.

Further, a cooling groove 48 for allowing cooling nitrogen gas to pass therethrough is provided on the upper and lower surfaces of the body mold 42. At the time of press molding, the cylinder die 42 is cooled by supplying cooling nitrogen gas to the cooling groove 48.

Referring back to FIG. The lower mold 44 is obtained by processing a round bar made of a cemented carbide, and has a molding recess for pressing an optical element on an upper end 44a. The glass material (for example, glass ball) described above is placed in the molding recess. In addition, the shape of the concave portion for molding is processed into an R shape corresponding to the surface shape of the aspheric lens to be molded.

The lower mold 44 has a large-diameter portion 44b protruding in the radial direction at the lower portion.

A heat insulating material 438 and a bottom plate 439 are laminated on the upper portion of the barrel base plate 437 disposed below the barrel mold 42, and the barrel mold 42 is fastened on the bottom plate 439. Further, the bottom plate 439 is provided with a groove (hidden in FIG. 4 and not visible) for allowing the nitrogen gas to escape when the cooling nitrogen gas flows.

A notch 42h is formed in the bottom 42g of the body mold 42, and a spacer member 400 is disposed in the notch 42h. Each lower mold 44 is placed on each spacer member 400. Each spacer member 400 adjusts variation in dimensional accuracy in the axial direction of each lower mold 44. That is, the spacer member 400 is in contact with the lower surface of the large-diameter portion 44b of each lower mold 44, and is configured such that the molding surface height of each lower mold 44 matches.

Four through holes 603a are formed in the bottom plate 20a of the vacuum chamber 20, and each lower mold pressure rod 602 is inserted into each through hole 603a. Each lower mold pressure rod 602 is pressurized upward by lower mold pressure applying means 370 (see FIG. 10) disposed on the lower surface side of the bottom plate 20a of the vacuum chamber 20 during press molding.

On the other hand, a passage 49 for supplying cooling nitrogen gas to the cooling groove 48 is provided in the center of the body-type base plate 437, the heat insulating material 438, and the bottom plate 439. A nitrogen supply pipe 435 that supplies cooling nitrogen gas is connected to the passage 49, and an electromagnetic valve V <b> 19 is disposed in the nitrogen supply pipe 435.

A cooling groove 48 is also provided on the upper surface of the body mold 42 that guides the upper mold 46. The cooling groove 48 is supplied with cooling nitrogen gas from a nitrogen supply pipe 436, and the nitrogen supply pipe 436. Is provided with a solenoid valve V20. Therefore, the body mold 42 is cooled by supplying the cooling nitrogen gas to the cooling grooves 40 formed on the upper and lower surfaces.
[Configuration of alignment means 90]
Next, the configuration of the alignment means 90 of the upper mold 46 will be described with reference to FIG.

As shown in FIG. 6, the alignment means 90 includes a spherical bearing 92 that supports the upper end of the upper mold 46 so as to freely swing, and a bearing holding member 94 that holds the outer periphery of the spherical bearing 92. The bearing holding member 94 is placed on a suspension member 312 having a peripheral edge portion 94 a suspended from the top plate 20 b of the vacuum chamber 20.

The upper mold 46 is obtained by processing a round bar made of cemented carbide, and has a molding recess or molding projection for pressing the optical element at the lower end 46a. In addition, the shape of the molding concave portion and the molding convex portion is processed into a curved surface shape corresponding to the surface shape of the aspheric lens to be molded.

Further, in the upper mold 46, a large diameter portion 46b protrudes in the radial direction in the vicinity of the upper end, and a lower portion 46c extending below the large diameter portion 46b is inserted into the upper guide hole 42b of the trunk mold 42. The upper mold 46 has an upper portion 46d extending above the large-diameter portion 46b. The upper portion 46d is inserted into the spherical bearing 92 and is held so as to be swingable in any direction.

Furthermore, a stopper ring 47 that prevents the spherical bearing 92 from falling off is engaged with the outer periphery of the upper portion 46d of the upper mold 46. In addition, a rivet-shaped pressure transmission member 49 having a head having a diameter larger than the outer diameter of the upper portion 46d is inserted into the shaft hole 46e opened at the upper end of the upper portion 46d of the upper mold 46. The pressure transmission member 49 is made of a cemented carbide and receives a load on the upper die 46, so that it is periodically replaced before being deformed or worn.

The spherical bearing 92 includes a sphere (inner ring) 95 that fits on the outer periphery of the upper portion 46 d of the upper mold 46, and a sphere receiving portion (outer ring) 96 having a spherical concave portion on which the outer periphery of the sphere 95 slides. The spherical body 95 is in sliding contact with the spherical concave portion of the spherical body receiving portion 96 without any gap, and sliding resistance is reduced.
Therefore, for example, when the axis of the upper mold 46 is shifted with respect to the upper guide hole 42b of the body mold 42, when the lower force 46c of the upper mold 46 acts on the upper mold 46 in the radial direction, the sphere 95 is loaded. Rotate in a small direction.

Thereby, the upper mold 46 can perform the alignment operation so that the axis coincides with the axis of the upper guide hole 42b of the body mold 42. In FIG. 6, the upper mold 46 on the left shows a state during the alignment operation inclined at an angle θ with respect to the axis, and the upper mold 46 on the right shows a state where the alignment is completed.

Further, since the spherical surface of the spherical body 95 and the spherical concave portion of the spherical body receiving portion 96 are in sliding contact with each other, the spherical body 95 can be rotated in any direction.

FIG. 7 is a longitudinal sectional view showing a press-molded state in which the body mold is moved up. As shown in FIG. 7, the upper mold 46 has a circular cross section, and a pressure transmission member 49 is attached to the upper end 46 d of the upper mold 46. When the body mold 42 is raised, the upper mold 46 is centered on the head of the pressure transmission member 49. It comes to receive press pressure.

The suspension member 312 is a member for suspending the bearing holding member 94 in the vacuum chamber 20, and the lower end hook portion 312 a is engaged with a peripheral portion 94 a protruding like a bowl from the outer periphery of the bearing holding member 94, The upper end hook portion 312 b is configured to be able to engage with a support member 303 attached to the top plate 20 b of the vacuum chamber 20. The support member 303 is omitted in FIG.

At the time of press molding, the body mold 42 is moved upward by the pressing force of the pressure increasing cylinder 81 of the pressure generating means 80, and the upper end 44a of the lower mold 44 is in contact with the lower end 46a of the upper mold 46. The glass material is pressurized by lifting it slightly (for example, several mm). At this time, since the bearing holding member 94 (upper mold support member) is also moved upward, the peripheral edge portion 94a of the bearing holding member 94 is spaced above the lower end hook portion 312a. Thereby, it changes to the state where the restraint with respect to the spherical bearing 92 is released, and a free operation state in which the alignment operation between the sphere 95 and the sphere receiver 96 is not hindered.

Further, the pressure that presses the upper die 46 is received by the annular spacer 91 interposed between the upper surface 42f of the body die 42 and the large-diameter portion 46b of the upper die 46, so that it is screwed into the upper end of the upper die 46. The pressure is transmitted to the upper mold pressure rod 302 that contacts the head of the pressure transmission member 49. Therefore, the spherical bearing 92 is configured such that no press pressure acts on it.

In this state, if the axis of the upper mold 46 is displaced with respect to the upper guide hole 42b of the body mold 42, a smooth alignment operation can be performed by the rotation of the spherical bearing 92. In this manner, the bearing holding member 94 is free to move by the aligning action of the spherical bearing 92 when the body mold 42 moves up and down, so that the inclination with respect to the axis is automatically corrected according to the movement of the body mold 42. it can. Accordingly, when the body mold 42 is moved up and down, it is possible to prevent the upper mold 46 from being inclined with respect to the axis of the body mold 42 and to prevent “galling” when the body mold 42 is slid.

Further, after the upper die 46 is held by the suspension member 312, the body die 42 is lowered and the molded product is taken out, and then the glass material G is again placed on each lower die 44 and pressure-molded again. In this case, the body mold 42 is raised with the upper mold 46 held by the suspension member 312. As a result, the body mold 42 is raised through the bearing holding member 94 and the spherical bearing 92 while the guide hole is in sliding contact with the upper mold 46 as a guide. At this time, the upper mold 46 does not operate, and is almost fixed in place. In this case, it is necessary to slide and move the barrel die 42 without causing “galling” between the four upper dies 46 and the barrel die 42, but this is possible by the action of the spherical bearing 92 described above.

When the body mold 42 is pulled down, the upper mold 46 keeps the horizontal plane with respect to the axis orthogonal to each other by the bearing holding member 94 and the spherical bearing 92. When the body mold 42 is raised from this state, the upper mold 46, the bearing holding member 94, and the spherical bearing 92 are held substantially in place by their own weight, and the above-described orthogonal state is maintained when the body mold 42 is raised. It can prevent galling.
In this way, the suspension member 312 is suspended so that at least the pressing force parallel to the sliding surface with the body die 42 acts at the center of the upper die 46 and the pulling force acts at the center of the upper die 46. Since the bearing holding member 94 to be supported is configured to be interlocked via the spherical bearing 92 of the alignment means 90, when the glass material G is press-molded, and the molded optical element molded product is released. At this time, the force of the upper and lower body members applied to the upper die 46 can always be caused to pass through the center of the upper die 46, and the optical functional surface is accurately positioned with respect to the optical axis. High optical elements can be manufactured efficiently.
[Configuration of Upper Mold Pressure Distribution Unit (Upper Mold Pressure Adjustment Mechanism) 100]
Next, the structure of the upper mold | type pressure distribution means 100 is demonstrated with reference to FIG. The upper mold pressure distribution means 100 is a pressure adjustment mechanism for the upper mold 46 provided on the upper surface of the top plate 20 b of the vacuum chamber 20, and has four upper lever means 102 arranged corresponding to each of the upper molds 46. And four upper cylinders 104. In FIG. 4, two are shown.

The upper lever means 102 includes an upper fulcrum member 105 that is fastened to the top plate 20b of the vacuum chamber 20 by a bolt or the like, and an upper swing member 106 that is connected to the upper end of the upper fulcrum member 105 via a connecting pin 105a. Has been. The upper fulcrum member 105 is slidably fastened to the attachment member 108 on the upper surface of the top plate 20b. Therefore, by changing the insertion position of the connecting pin 105a with respect to the plurality of holes 106a provided in the upper swinging member 106 and changing the fastening position of the upper fulcrum member 105 with respect to the mounting member 108, the pressure of the upper lever means 102 is changed. Can be adjusted.

The upper mold pressure rod 302 extending in the vertical direction so as to penetrate the top plate 20 b of the vacuum chamber 20 has an upper end connected to one end of the upper swinging member 106 via a connection pin 109. The other end of the upper swinging member 106 is connected to the piston rod 104 a of the upper cylinder 104 through a connecting pin 107. Therefore, when the upper mold 46 is pressed upward during the press molding described above, the pressure due to the upward movement is transmitted to the upper swing member 106 via the upper mold pressure rod 302, and the upper fulcrum member 105 is centered. The upper swing member 106 swings to drive the piston rod 104a of the upper cylinder 104 in the compression direction.

The upper cylinder 104 is an air cylinder, and the cylinder is filled with high-pressure air. Therefore, when a compressive load is applied to the piston rod 104a, the piston rod 104a slides downward, and the pressure by which the air is compressed and pushes the piston rod 104a upward increases. This pressure is increased by a ratio corresponding to each distance of the connecting pins 107, 105a, 109 determined by the connecting position of the upper swing member 106 and the upper fulcrum member 105.

Therefore, the pressure generated in the upper cylinder 104 is increased by the upper lever means 102 and transmitted to the upper mold 46 via the upper mold pressure rod 302. As a result, the upper die 46 receives pressure pressed upward by the lower die 44 and is pressed downward by the pressure generated in the upper cylinder 104, and is held in a stable state in which the pressures in both directions are balanced. Therefore, the glass material press-formed between the lower mold 44 and the upper mold 46 is pressed in a state in which the glass material is in close contact with the surfaces of the upper end 44a of the lower mold 44 and the lower end 46a of the upper mold 46, and the upper end 44a It is molded into an aspheric lens according to the space shape formed between the lower end 46a.

In this case, it is desirable that the pressing force of the pressure generating means 80 (for example, the total load is 19.6 kN) is applied to each upper mold 46 equally so that a load of 4.9 kN is applied to each upper mold 46. If there is a variation in the distribution load, the quality of the four molded products (optical elements) (for example, variation in lens thickness due to pressing, variation in shape and accuracy) is affected. In addition, there are naturally variations in the dimensions of the four lower molds 44, the upper mold 46, the upper mold pressure rod 302, and the like, so that there is a difference in the pressing stroke of each mold due to the pressing force of the pressure generating means 80. Arise.

In order to mold a high-precision optical element by heating the glass material, it is necessary to apply a high pressure (3.92 to 5.88 kN) to each upper mold 46. Further, in an apparatus of a method of repeating a process of heating a glass material to a predetermined temperature (400 to 800 ° C.) in a mold, pressing and then taking out the molded product (optical element), the molded product, mold member, barrel Since it is required to shorten the heating-cooling-heating cycle in order to repeat heating and cooling of the mold and the like, it is necessary to reduce the heat capacity of the entire mold apparatus, and therefore it is necessary to reduce the size of the apparatus.

Further, in the apparatus of the embodiment, in order to obtain the same molded product, for example, a lens having the same thickness, by using the four mold members, the upper mold 46 is formed by the upper mold pressure rod 302 and the rising barrel mold 42 shown in FIG. , The upper surface 42f of the body mold 42 is pressed against the lower end surface of the large-diameter portion 46b of the upper mold 46 through the spacer 91, and the moving position of the body mold 42 is restricted, so that the wall thickness of the molded product Is determined.

In other words, it is a necessary condition for obtaining the thickness dimensions of the four molded products that the upper surfaces 42f of all the barrel dies 42 abut against the four upper dies 46 via the spacers 91. For this purpose, a pressing force is applied independently to each of the four upper molds 46, and the upper surface 42 f of the barrel mold 42 completely abuts on each upper mold 46, and a sufficient pressing force is applied to the upper mold 46. There is a need.

In the present embodiment, the pressure generated by the upper cylinder 104 disposed on the top plate 20b of the vacuum chamber 20 is increased by the upper insulator means 102 to cause the upper mold 46 to act on the upper mold 46. A sufficient pressing force against the upper mold 46 can be obtained. Further, in the upper mold pressure distribution means 100, the vacuum chamber 20 can be reduced in size by disposing the upper cylinder 104 outside the vacuum chamber 20, and the upper cylinder 104 can be obtained by using the upper insulator means 102. The size of the device itself can be reduced.

In the present embodiment, the configuration in which the air cylinder is applied to the upper cylinder 104 has been described as an example. However, the present invention is not limited to this, and a cylinder device that fills a gas other than air may be used. A pressure means (such as an accumulator) may be provided.

When a pressing force is applied to the body mold 42 from the pressure increasing cylinder 81 of the pressure generating means 80, press molding is started between the lower mold 44 and the upper mold 46 that rise together with the body mold 42. By this pressing operation, the upper die pressure rod 302 is pushed up through the upper die 46 and one end of the swing member 106 of the upper lever means 102 is pushed up. Thereby, the upper cylinder 104 is compressed.

As the press progresses, the upper die 46 moves while slidingly contacting the guide holes 42b of the barrel die 42, and until the spacer 91 placed on the upper surface 42f of the barrel die 42 contacts the large diameter portion 46b of the upper die 46. The mold 2 is moved. Here, in each of the four mold sets, when the spacers 91 are in contact with the large diameter portions 46b of the three upper molds 46, the spacers 91 are disposed on the large diameter portions 46b of the other upper molds 46. Let's consider the state in which does not contact. In this case, the spacer 91 can be pressed against the non-contact upper die 46 by compressing the upper cylinder 104 via the upper die pressure rod 302 by the pressure from the pressure generating means 80. As a result, all the positions of the four upper molds 46 can always be secured at a fixed position, so that the thickness of all the molded products can be maintained.

Next, a specific example of the upper die pressure distribution means 100 will be described. When an air cylinder having a maximum load of 568 N is used as the upper cylinder 104, the position of the upper fulcrum member 105 that supports the swing member 106 is the ratio of the distance to the upper mold pressure rod 302 and the distance to the upper cylinder 104. Will be described in a configuration in which the members are assembled so as to be 1:10. As a result, a pressure adjusting mechanism that can withstand a load that is ten times the maximum load of the upper cylinder 104 (5.68 kN in this case) can be configured based on the principle of the lever. By assembling the four pieces so as to correspond to each upper mold 46, a pressure adjusting mechanism for taking four pieces is completed (withstands up to 22.7 kN at the total pressure). Therefore, compared with the molding apparatus disclosed in Japanese Patent No. 2815037 in which a disc spring is incorporated in the vacuum chamber 20, there is no need for a large amount of disc springs, so there is no need for spring adjustment work, and it is installed outside the vacuum chamber 20. As a result, there is enough space and the design becomes easy.

Further, unlike the conventional device using the disc spring, it is not necessary to cool the upper cylinder 104, so that it is not necessary to provide piping for supplying cooling water. That is, in this embodiment, it is not necessary to provide a cooling mechanism for cooling the upper cylinder 104, and corrosion prevention of the upper die 46 and the lower die 44 made of cemented carbide when cooling water leaks, etc. There is no need to take any measures.

Furthermore, it is possible to cope with various press pressures only by changing the air pressure supplied to the upper cylinder 104, and there is no need to disassemble and adjust the disc spring portion as in Japanese Patent No. 2815037. By changing the position of the upper fulcrum member 105 instead of changing the air supply pressure to the upper cylinder 104, it is possible to cope with various press pressures, and this method is also easier than in Japanese Patent No. 2815037. Adjustment is possible.

In this state, the thrust of the pressure increasing cylinder 81 of the pressure generating means 80 (total applied pressure applied to the four upper molds 46) was set to 19.6 kN, and the pressure variation between the upper mold pressure rods 302 was measured. It was confirmed that it would fit in the variation of 98N in the range. After that, using a die set in which the height variation up to the spacer 91 is adjusted to within 0.2 mm, the finished size is φ10 mm, the center size is 19.6 kN, which is one of the molding conditions. When a lens for a video camera with a wall thickness of 3.5 mm and a lens surface curvature of 15 and 20 mm was molded, all four molds were completely pushed through without any inconvenience such as galling. Also, the molded product completely matched the cavity space formed by each mold, and a molded product that sufficiently satisfied the thickness accuracy and the allowable value of the optical surface inclination was obtained.
[Configuration of in-furnace hand mechanism 50]
Next, the configuration of the in-furnace hand mechanism 50 will be described with reference to FIGS. 8A and 8B. As shown in FIGS. 8A and 8B, the in-furnace hand mechanism 50 has a horizontal holding mechanism 56 that holds the suction hand 52 horizontally at the tip of the arm 54. The in-furnace hand mechanism 50 has an air cylinder 50a on the top surface of the top plate 20b of the vacuum chamber 20, and the rotary shaft 50b is driven to rotate by the air cylinder 50a. An arm 54 is connected to the lower end of the rotary shaft 50 b, and the suction hand 52 rotates together with the arm 54. Further, the suction hand 52 is provided with four vacuum suction pads 53 on the lower surface side. The interval between the vacuum suction pads 53 is the same as the interval between the lower molds 44.

Further, a pair of positioning holes 51 into which a pair of positioning pins 43 provided in the body mold 42 are fitted is provided on the lower surface of the suction hand 52. By fitting the pair of positioning holes 51 to the pair of positioning pins 43, the four vacuum suction pads 53 are positioned at positions facing the lower molds 44 in the body mold 42.

The horizontal holding mechanism 56 is connected between a pair of plate members 57 connected to side surfaces of the upper base 55a and the intermediate base 55b fixed to the lower surface of the front end of the arm 54, and the intermediate base 55b and the lower base 55c. There are four bolts 58 and four coil springs 59 wound around the outer periphery of each bolt 58. The lower base 55 c is fixed to the base 52 a of the suction hand 52 and is held in a horizontal state by the spring force of the four coil springs 59. The suction hand 52 has a lower base 55c fastened to the upper surface of the base, and is held in a horizontal state together with the lower base 55c.

Further, in the horizontal holding mechanism 56, the intermediate base 55b is horizontally held by a pair of plate members 57, and the lower base 55c is moved in the Z direction and X by the compression deformation of the four coil springs 59 arranged on the lower surface side of the intermediate base 55b. It is held so that it can be displaced around the axis and around the Y axis.

Each bolt 58 passes through the intermediate base 55b and is screwed into the lower base 55c, and the head is larger than the hole diameter of the intermediate base 55b, and is attached so as not to drop off from the intermediate base 55b. Further, when an upward external force acts on the lower base 55c, the bolt 58 operates so as to protrude above the intermediate base 55b, and the coil spring 59 is compressed, so that the lower base 55c can be displaced upward. When the external force disappears, the lower base 55 c returns to the horizontal state by the spring force of each coil spring 59.

Further, when an external force in a tilting direction is applied to the suction hand 52, any of the four bolts 58 protrudes upward from the intermediate base 55b and absorbs the tilt. When the external force disappears, the spring force of the coil spring 59 returns to the original horizontal state, and the suction hand 52 is held horizontally.

Further, an abutting member for regulating the vertical movement amount is disposed between the suction hand 52 and the positioning pin 43. The suction pad 53 is made of a material having low thermal conductivity for the purpose of preventing the molded product from being broken by heat shock, and is made of a heat-resistant material for adsorbing a high-temperature molded product. . One example is polyimide resin.

In addition, the in-furnace hand mechanism 50 is configured such that, while the glass material G is adsorbed to the suction pad 53, the suction pad 53 is moved by the rotation operation of the rotary shaft 50a based on the rotation control of the air cylinder 50b and the barrel-type vertical positioning mechanism. Introduced into the mold 42, and in a state where the molded product is adsorbed by the suction force of the suction pad 53, it is taken out from the cylinder mold 42 by the upward / downward positioning mechanism of the cylinder mold 42 and the rotation of the rotating shaft 50b in the reverse direction. To work.
[Suction piping system of the in-furnace hand mechanism 50]
FIG. 9 is a diagram showing a piping path of the suction control unit 260 connected to each suction pad 53. As shown in FIG. 9, each suction pad 53 is connected to each suction pipe 501 to 504 of the suction control unit 260, and each suction pipe 501 to 504 is connected to two branch pipes 506 and 507. Has been. In each of the suction pipes 501 to 504, pressure sensors 511 to 514 and suction electromagnetic valves V1 to V4 are arranged.

Further, variable throttles 516 and 517 for adjusting the flow rate are arranged in the branch pipes 506 and 507. Further, the nitrogen pipes 521 to 524 are provided with variable throttles 531 to 534 for adjusting the flow rate and electromagnetic valves V5 to V8.

Each suction pad 53 is configured to be able to independently suck or release the suction corresponding to each of the four lower molds 44 by opening the electromagnetic valves V1 to V4. The suction source is a vacuum pump unit 170. is there. The suction pipes 501 to 504 branched from the vacuum pump unit 170 are connected to the suction pads 53, and variable throttles 516 and 517 for adjusting the flow rate at a ratio of one for two of the four suction pipes 501 to 504 are arranged. The suction pressures of the four suction pipes 501 to 504 are controlled semi-independently. Since the four suction pipes 501 to 504 are equipped with the pressure sensors 511 to 514, respectively, the holding pressure can be controlled without any problem even if the suction pressure is semi-independent. In order to break the vacuum for releasing the adsorption force, a mechanism for reverse injection of nitrogen is provided, and variable throttles 531 are provided in the four nitrogen pipes 521 to 524 so that the reverse injection force can be controlled independently in each line. 532, 533, and 534 are arranged, respectively.

Therefore, in the present embodiment, the suction force of each of the four suction pads 53 can be controlled by the variable throttles 516 and 517, and the number of throttles is smaller than when the variable throttles are provided in each of the suction pipes 501 to 504. This is advantageous in terms of cost.
[Configuration of Lower Mold Pressure Applying Unit 370]
FIG. 10 is a diagram showing the configuration of the lower mold pressure applying means (lower mold pressure adjusting mechanism) 370. The lower mold pressure applying means 370 shown in FIG. 10 is provided on the support member 85 that transmits the pressure generated by the pressure increasing cylinder 81 of the pressure generating means 80 to the body mold 42. The support member 85 is formed in a rectangular shape, and includes a lower base 85a to which the raising / lowering drive shaft 84 of the booster cylinder 81 is connected, a support 85b extending above both sides of the lower base 85a, and an upper end of the support 85b. And an upper base 85c connected thereto.

The lower mold pressure applying means 370 includes four lower lever means 600 attached to the lower surface of the upper base 85c of the support member 85 and four lower cylinders 610. Each lower lever means 600 and each lower cylinder 610 are arranged corresponding to each lower mold 44.

The lower lever means 600 includes four lower mold pressure rods 602 that press each lower mold 44 from below, a lower fulcrum member 604 fastened to the lower surface of the upper base 85c, and a connecting pin 604a of the lower fulcrum member 604. The lower swinging member 606 is swingably supported at the center.

The lower fulcrum member 604 is slidably fastened to the attachment member 608 on the lower surface of the upper base 85c. Therefore, the pressure of the lower lever means 600 is changed by changing the insertion position of the connecting pin 604a with respect to the plurality of holes 606a provided in the lower swinging member 606 and changing the fastening position of the lower fulcrum member 604 with respect to the mounting member 608. Can be adjusted.

The lower cylinder 610 is an air cylinder, and the cylinder is filled with high-pressure air. When the compression load is applied to the piston rod 610a, the piston rod 610a slides downward, and the pressure by which the air is compressed and pushes the piston rod 610a upward increases. This pressure is increased by a ratio corresponding to each distance between the connection pins 607 and 604a and the recess 606b determined by the connection position between the lower swing member 606 and the lower fulcrum member 604.

The lower mold pressure rod 602 has a lower end fitted in a recess 606 b provided at one end of the lower swinging member 606. The other end of the lower swing member 606 is connected to the lower end portion of the piston rod 610 a of the lower cylinder 610 via a connecting pin 607.

When the lifting drive shaft 84 of the pressure generating means 80 is pressed upward during the press forming described above, the lower mold pressure applying means 370 is pressed upward together with the support member 85, the lifting base 43, and the body mold 42.

The lower mold pressure applying means 370 increases the pressure applied to the lower cylinder 610 in a state where the lower mold 44 is close to the upper mold 46 by the upward movement of the body mold 42. As a result, the lower cylinder 610 drives the piston rod 610a downward, and moves the lower mold pressure rod 602 upward via the lower swing member 606. The lower mold pressure rod 602 presses the lower mold 44 upward. The pressure due to the upward movement of the lower mold pressure rod 602 becomes the press pressure of the lower mold 44 against the glass material placed between the lower mold 44 and the upper mold 46.

The glass material press-formed between the lower mold 44 and the upper mold 46 is pressed in a state in which the glass material is in close contact with the molding surface of the upper end 44a of the lower mold 44 and the molding surface of the lower end 46a of the upper mold 46 without any gap. The aspherical lens is formed in accordance with the space shape formed between the upper end 44a and the lower end 46a.
[Configuration of Centering / Scraper Mechanism 60]
FIG. 11A is a plan view showing a state before the operation of the centering / scraper mechanism 60. FIG. 11B is a side view showing a state before the operation of the centering / scraper mechanism 60. As shown in FIGS. 11A and 11B, the centering / scraper mechanism 60 supports two sets of insertion portions 710 each having four insertion levers 700 extending in the horizontal direction (Y direction), and the insertion portion 710. In addition, a lever support portion 720 that vibrates each insertion lever 700 in the X direction, a Z-axis drive portion 730 that moves the lever support portion 720 in the Z direction, a moving base 740 that supports the Z-axis driving portion 730, and a moving stand 740 Has a Y-axis direction drive unit 750 that moves the Y-axis direction drive unit 750 and a mounting base 760 that supports the Y-axis direction drive unit 750.

The mounting base 760 is fastened to a trunk base plate 437 on which the trunk mold 42 is placed and fixed. In addition, the insertion lever 700 of the insertion portion 710 is inserted into the molding space 42 c of the body mold 42 from the horizontal direction.

A pair of insertion levers 700 arranged in parallel in the Y direction are arranged as a pair, and the lever support portion 720 opens and closes the pair of insertion levers 700 in the proximity direction or the separation direction when centering. Lever driving means for driving is provided. As the lever driving means, an air cylinder driven by air pressure may be used, or a swinging actuator driven by air pressure may be used.

The pair of insertion levers 700 can simultaneously press the glass material placed on the lower mold 44 from both sides by vibrating so as to approach and separate from each other like scissors.

Further, concave portions 700a and 700b corresponding to the diameter of the glass material are provided on the side surfaces of the pair of insertion levers 700 that are close to each other. The distance between the centers of the recesses 700a and 700b is set to the same distance as the distance between the lower molds 44 in the Y direction.

FIG. 12A is a plan view showing the centering / scraper mechanism 60 during operation. FIG. 12B is a side view showing the centering / scraper mechanism 60 during operation. As shown in FIGS. 12A and 12B, the centering / scraper mechanism 60 is mounted on an elevating base 43 that supports the body mold 42, and the height position of the insertion lever 700 with respect to the body mold 42 by the Z-axis drive unit 730. Is adjusted, and the insertion lever 700 is inserted into the molding space 42 c of the body mold 42 by the Y-axis direction drive unit 750.

FIG. 13 is a plan view showing the centering operation of the centering / scraper mechanism 60.
As shown in FIG. 13, when the glass material G is placed on the lower mold 44, each insertion lever 700 is inserted into the molding space 42 c of the trunk mold 42. Then, the recesses 700 a and 700 b of each insertion lever 700 are lowered so as to be positioned on both sides of the glass material G placed on the upper end of the lower mold 44. In this example, the glass material G before pressing is not spherical and is formed in advance in an elliptical shape close to the optical element to be molded, and therefore, it is difficult to roll.

In this insertion state, when each insertion lever 700 is vibrated in the X direction, the recesses 700a and 700b of each insertion lever 700 are repeatedly moved in the proximity direction (closing direction) a plurality of times.
For example, as shown in FIG. 14A, a position (indicated by a solid line) where the glass material G deviates in the radial direction from the center position (indicated by a one-dot chain line) of the forming surface (the forming recess) formed on the upper end 44 a of the lower mold 44. The centering operation in the case of being placed on () will be described. As described above, the recesses 700a and 700b of each insertion lever 700 reciprocate in the X direction to press the outer periphery of the glass material G toward the center. As a result, the glass material G moves to the center of the molding surface (molding recess) formed on the upper end 44a of the lower mold 44 by being pressed by the recesses 700a and 700b of the vibrating insertion levers 700. FIG. 14B shows a state after adjustment in which the glass material G is centered at the center of the molding surface (molding recess) by the reciprocating motion of each of the insertion levers 700.

Accordingly, even when the glass material G is separated from the suction pad 53 and placed on the upper end 44 a of the lower mold 44, the glass material G is inserted in a position shifted from the axis of the lower mold 44. By being simultaneously pressed from both sides by the concave portions 700 a and 700 b of the lever 700, the lever 700 is centered so as to be positioned at the axis of the lower mold 44.
[Configuration of heater unit 70]
FIG. 15A is a plan view showing a state before the heater unit 70 operates. FIG. 15B is a plan view showing the heater unit 70 during operation. As shown in FIG. 15A, the heater unit 70 includes a glass heater 800 and a drive unit 804. The glass heater 800 includes a plurality of cartridge heaters 802 and is connected to an independent temperature controller, and the heating temperature at which the temperature is detected is controlled by a thermocouple 803 inserted into the glass heater 800. The plurality of cartridge heaters 802 are each formed in a cylindrical shape, and are arranged in parallel in the flat heater portion 801 so as to extend in the same direction.

Further, since the glass heater 800 is set to a high temperature (for example, 900 ° C.), it is made of a material that can withstand the high temperature (for example, SKD61, SKD62, Hastelloy, more preferably Ambiloy, cemented carbide).

The driving unit 804 and the heater unit 801 are connected by a connecting unit 805. The drive unit 804 is formed of, for example, an air cylinder, and the glass heater 800 is inserted from the side surface opening 42d of the trunk mold 42 by air pressure supplied by opening the electromagnetic valve V18.

As shown in FIG. 15B, the plurality of cartridge heaters 802 heat the heater unit 801 in a state of being energized and generate heat, and the heater unit 801 maintained at a constant temperature (heating temperature) It is inserted into the molding space 42c.

Here, the operation of the step of heating the glass material G and the step of press molding will be described.

As shown in FIG. 16A, since the glass material G placed on the upper end 44a of the lower mold 44 is located below the heater unit 801, the viscosity of the glass is, for example, 10 by the heat radiated from the heater unit 801. Heated to ⁷ dPa · s.

The heater portion 801 held at 900 ° C. by the cartridge heater 802 is inserted between the lower mold 44 and the glass material G and below the upper mold 46 from the opening 42 d of the body mold 42. The distance between the glass heater 800 and the glass material G can be freely set by adjusting the rising position of the body mold 42. The upper mold 46 and the lower mold 44 are heated to, for example, a glass viscosity of about 10 ⁹ dPa · s by a cartridge heater inserted into the body mold 42. On the other hand, the glass material G is heated by the glass heater 800 to a temperature of, for example, about 10 ⁷ dPa · s in terms of glass viscosity. After the glass material G and the upper mold 46 and the lower mold 44 are heated for a desired time (for example, 90 seconds), the cylinder mechanism 72 (see FIG. 1) of the heater unit 70 is operated to make the glass heater 800 a barrel mold. Pull out from 42.

Thereafter, as shown in FIG. 16B, the body mold 42 is raised by the pressure of the pressure-increasing cylinder 81 of the pressure generating means 80 and press-molded.

After the large-diameter portion 46b of the upper mold 46 is sufficiently in contact with the upper end of the body mold 42 via the spacer 91 (for example, after 10 seconds), a cooling medium (for example, nitrogen gas) is supplied to the cooling groove 48 of the body mold 42. When the glass viscosity is, for example, between about 10 ^10.5 dPa · s and about 10 ¹³ dPa · s, the pressure of the lower cylinder 610 presses the lower mold 44 upward via the lower lever means 600 to lower the lower mold 44. Press pressure is applied (eg 3KN at total pressure).

When the lower mold 44 moves upward together with the body mold 42 by the pressure of the pressure generating means 80 and the glass material G is pressed between the upper end 44a of the lower mold 44 and the lower end 46a of the upper mold 46, the glass material G is formed on the molding surface. It is formed into a shape corresponding to a predetermined shape (for example, an elliptical shape). The upper mold 46 has a small-diameter step 46c formed on the outer periphery of the lower end 46a.

As shown in FIG. 17A, when a predetermined time of press forming for the glass material G elapses, the insertion lever 700 is inserted into the small diameter step 46c formed at the lower end of the upper mold 46 of the centering / scraper mechanism 60 described above. . At this time, the insertion height of the insertion lever 700 is adjusted to the height position of the small-diameter step portion 46c by the Y-axis direction drive unit 750 (see FIG. 12B). Therefore, the insertion lever 700 is inserted at a height that does not contact the glass material G, and is inserted so as not to damage the glass material G.

Further, each insertion lever 700 is driven in the X direction in which a pair of levers are close to each other, and the recesses 700a and 700b are close to the small diameter step 46c. In this insertion state, each insertion lever 700 is not in contact with the peripheral edge portion of the glass material G (optical element) formed in an elliptical shape.

As shown in FIG. 17B, when the barrel mold 42 and the lower mold 44 are lowered and released, the insertion lever 700 of the centering / scraper mechanism 60 mounted on the lifting base 43 is also lowered.
Therefore, the lower surface of the insertion lever 700 comes into contact with the peripheral edge of the molded optical element G and presses the optical element G downward. Since the optical element G is press-molded in the heated state, the optical element G is in close contact with the molding surface of the upper mold 46 and may not be dropped by its own weight alone.

Therefore, when the insertion lever 700 of the centering / scraper mechanism 60 is released from the small-diameter step portion 46c of the upper mold 46, the insertion lever 700 is lowered together with the body mold 42, so that the optical element is placed on the lower mold 44. Can be made. As a result, when the optical element after molding is taken out from the molding space 42 c of the barrel mold 42, the suction hand 52 attached to the tip of the arm 54 is driven into the molding space 42 c of the trunk mold 42 by driving the in-furnace hand mechanism 50. Inserted. Then, after adjusting the height position of the body mold 42 to a position where it is easy to attract according to the height position of the suction hand 52, the electromagnetic valves V1 to V4 are opened, and vacuum pumps are provided to the suction pads 53 of the suction hand 52. The vacuum generated by unit 170 is supplied.

As a result, each suction pad 53 of the suction hand 52 sucks the optical element placed on the lower mold 44, and takes out the optical element formed by the rotation of the arm 54 from the barrel mold 42. Then, the optical element is transferred to the shifter 140 by the operation of the in-furnace hand mechanism 50, and when the optical element moves to a predetermined position on the shifter 140, the suction by the suction pad 53 is released and is placed on the shifter 140. The subsequent optical elements are collected in the replacement chamber 130 together with the shifter 140 by driving the shifter moving means 150, and further transferred to the pallet 112 in the stocker chamber 30 by the collecting operation of the SCARA robot 120.
[Modification]
Here, a modified example will be described. FIG. 18 is a longitudinal sectional view showing a modification of the upper die pressure distribution means 100. As shown in FIG. 18, when the upper cylinder 104 has a long dimension in the vertical direction, the end of the main body 104 b of the upper cylinder 104 is connected to the other end of the upper swing member 106. The piston rod 104 a of the upper cylinder 104 extends downward from the end of the main body 104 b and is fixed to the top plate 20 b of the vacuum chamber 20 by a fixing member 101.

Therefore, when the upper swing member 106 swings around the upper fulcrum member 105, the main body 104b moves up and down relative to the piston rod 104a, and a load is applied to the upper cylinder 104. As a result, the pressure generated in the upper cylinder 104 is applied to the upper mold pressure rod 302 via the upper swing member 106. Therefore, the upper die 46 is buffered with a pressing force from below the lower die 44 by the pressure of the upper cylinder 104 and is given a pressing force against the lower die 44.

In this modification, the operation and effect of the upper pressure distribution means 100 are the same as those shown in FIG.

FIG. 19A is a side view showing Modification 1 of the suction hand 52 of the in-furnace hand mechanism 50. FIG. 19B is a plan view showing Modification 1 of the suction hand 52 of the in-furnace hand mechanism 50. As shown in FIGS. 19A and 19B, the base 52a of the suction hand 52 is held so as to be always kept horizontal by a horizontal holding mechanism 900 disposed between the upper base 55a fixed to the lower surface of the arm 54. Has been. The horizontal holding mechanism 900 is also referred to as a so-called wrist compliance, and includes a central shaft 910 between the upper mounting portion 902 and the lower mounting portion 904, and three elastic members 920 around the center shaft 910 in the circumferential direction. It is arranged at intervals of degrees. The three elastic members 920 are attached such that each lower end is inclined with respect to the central axis 910. Therefore, when the suction hand 52 receives an external force and tilts around the X axis or the Y axis, one of the three elastic members 920 receives a compressive load, and each elastic member 920 has an equal force. Thus, the suction hand 52 can be returned to the direction in which the suction hand 52 is urged, that is, in a horizontal state.

FIG. 20A is a side view showing a second modification of the suction hand 52 of the in-furnace hand mechanism 50. FIG. 20B is a plan view showing Modification Example 2 of the suction hand 52 of the in-furnace hand mechanism 50. As shown in FIG. 20A, the base portion 52a of the suction hand 52 is supported by a linear guide 950 so as to be movable up and down. The linear guide 950 is formed in a U-shape (a shape seen from above) so as to surround the guide rail 952 extending in the vertical direction from the lower surface of the arm 54 and the three surfaces (front and left and right side surfaces) of the guide rail 952. And a slider 954.

The guide rail 952 is provided with Z-axis driving means for driving the slider 954 in the vertical direction. The Z-axis driving means includes, for example, a ball screw or a linear motor, and can be selected as appropriate.

Since the base 52 a of the suction hand 52 is coupled to the slider 954, it can move only in the vertical direction (Z direction) that is the driving direction of the slider 954. Further, the suction hand 52 can be rotated in the horizontal direction by the turning operation of the arm 54.

As shown in FIG. 20B, when the glass material G is attracted to the suction pad 53, the suction hand 52 can be lowered in a horizontal state by lowering the slider 954. It is possible to perform the suction operation so that the positional deviation from G does not occur. Also, since the arm 54 can be raised and lowered, and only the suction hand 52 can be raised and lowered, the suction hand 52 can be quickly raised and lowered to shorten the suction operation time.

According to the present invention, it is possible to provide a mold for optical glass suitable for a precision press molding method excellent in durability and releasability from optical glass. In addition, since various optical elements can be manufactured without being polished after molding by press molding optical glass using this mold, an optical element manufacturing method that is mass-productive and advantageous in terms of cost can be provided. .

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on April 23, 2008 (Japanese Patent Application No. 2008-113006), the contents of which are incorporated herein by reference.

10 Press molding equipment 20 Vacuum chamber (housing)
30 Stocker chamber 40 Mold unit 42 Molding die 42c Molding space 43 Lifting base 44 Lower die 44a Upper end 46 Upper die 46a Lower end 46b Large diameter portion 46c Small diameter step portion 48 Cooling groove 49 Pressure transmission member 50 In-furnace hand mechanism 52 Suction hand 53 Suction pad 60 Centering / scraper mechanism 70 Heater unit 80 Pressure generating means 81 Boosting cylinder 84 Lifting drive shaft 85 Support member 90 Alignment means 91 Spacer 92 Spherical bearing 94 Bearing holding member 94a Peripheral part 100 Upper die pressure distribution means ( Upper mold pressure adjustment mechanism)
102 Upper lever means 104 Upper air cylinder 104a Piston rod 105 Upper fulcrum member 106 Upper rocking member 110 Pallet table 120 SCARA robot 122 Vacuum chuck 130 Replacement chamber 132 Communication path 140 Shifter 150 Shifter moving means 154 Air cylinder 160 Gate valve 170 Vacuum Pump unit 190 Air pipe 200 Nitrogen pipe 210 Cooling nitrogen pipe 220 Vacuum pipe 260 Adsorption control unit 300 Control device 302 Upper mold pressure rod 303 Support member 310 High-pressure air supply unit 312 Suspension member 312b Upper end hook part 312a Lower end hook part 320 Gate valve opening / closing mechanism 330 Replacement chamber pressure adjustment unit 340 Chamber pressure adjustment unit 350 Nitrogen supply unit 360 Nitrogen cooling unit 370 Lower mold pressure applying means (lower mold pressure regulator) )
435 Nitrogen supply pipe 600 Lower insulator means 602 Lower mold pressure rod 604 Lower fulcrum member 606 Lower swing member 608 Mounting member 610 Lower cylinder 610a Piston rod 700 Insert lever 700a, 700b Recess 800 Glass heater 802 Cartridge heater 900 Horizontal holding mechanism 950 Linear guide 952 Guide rail 954 Slider V1 to V27 Solenoid valve

Claims (14)

1. In an optical element press molding apparatus for molding an optical element by pressing a glass material between a plurality of upper molds and a plurality of lower molds paired with the upper mold,
   Lower mold pressure applying means for applying pressure to the plurality of lower molds;
   The plurality of pairs of upper molds are inserted from above, the plurality of pairs of lower molds are inserted from below, and a trunk mold that guides the relative positions of the upper mold and the lower mold,
   Pressure generating means for pressing the barrel mold upward;
   As the body mold is moved upward by the pressing force of the pressure generating means, the upper mold pressure distributing means for pressing each upper mold downward and applying pressure to each upper mold independently. And having
   The upper mold pressure distribution means includes:
   An upper cylinder that receives a load due to pressure acting on the upper mold;
   An upper swinging member that is swingably disposed through a fulcrum, has one end abutting against the upper end of the upper mold, and the other end coupled to the upper cylinder;
   In the process of moving the barrel mold upward by the pressure generating means, the pressure on the upper mold by the upper cylinder is adjusted via the upper swing member, and the lower mold is pressed upward by the lower mold pressure applying means. An optical element press molding apparatus.
2. A housing that houses at least the upper mold, the lower mold, and the trunk mold;
   The optical element press molding apparatus according to claim 1, wherein the upper cylinder and the upper swing member are disposed on an upper surface of the casing.
3. The lower mold pressure applying means presses the plurality of lower molds upward as the body mold is moved upward by the pressing force of the pressure generating means. Optical element press molding equipment.
4. The lower mold pressure applying means includes
   A lower cylinder that receives a load due to pressure acting on the lower mold;
   A lower swinging member that is swingably disposed through a fulcrum, one end of which is in contact with the lower end of the lower mold, and the other end is coupled to the lower cylinder;
   4. The press molding apparatus for an optical element according to claim 3, wherein the lower swing member swings about the fulcrum to adjust the pressure applied to each lower die by the lower cylinder.
5. A plurality of alignment means for aligning the position of the upper mold with respect to the cylinder mold in the process of moving the cylinder mold upward with a pressing force by the pressure generating means;
   Each of the plurality of alignment means includes
   A spherical bearing that allows the upper mold to rotate so that the axis of the upper mold coincides with the axis of movement of the trunk mold when the barrel mold is pressed upward;
   An upper mold support member that is formed to support the outside of the spherical bearing, and from which the spherical bearing is separated by the upward pressing operation;
   The press molding apparatus for an optical element according to claim 1.
6. The upper mold pressure distribution means can change the connection position of the fulcrum with respect to the longitudinal direction of the upper swing member, and acts on the upper mold according to the ratio between the connection position of the fulcrum and the total length of the upper swing member. The press molding apparatus for an optical element according to claim 1, wherein the pressure to be adjusted is adjusted.
7. The lower mold pressure applying means can change the connection position of the fulcrum with respect to the longitudinal direction of the lower swing member, and acts on the lower mold according to the ratio between the connection position of the fulcrum and the total length of the lower swing member. The press forming apparatus for an optical element according to claim 4, wherein the pressure to be adjusted is adjusted.
8. 2. The optical element according to claim 1, wherein the upper die pressure distribution unit is configured such that a filling pressure in the upper cylinder is variable, and a pressure acting on the upper die is adjusted by the filling pressure. Press molding equipment.
9. 5. The optical element according to claim 4, wherein the lower mold pressure applying means is configured such that a filling pressure in the lower cylinder is variable, and a pressure acting on the lower mold is adjusted by the filling pressure. Press molding equipment.
10. 2. The optical element press molding apparatus according to claim 1, wherein the upper cylinder is an air cylinder filled with a gas having a predetermined pressure.
11. 5. The optical element press molding apparatus according to claim 4, wherein the lower cylinder is an air cylinder filled with a gas having a predetermined pressure.
12. A centering member that is inserted between the upper mold and the lower mold before pressing and centers the position of the glass material placed on the lower side from both sides to the center of the lower mold;
    2. The optical element according to claim 1, wherein the centering member lowers the body mold after pressing the glass material to mold the optical element, and presses a peripheral edge of the optical element downward. Press molding equipment.
13. A suction hand for moving the inside of the housing and placing the glass material on the molding surface of the lower mold in the barrel mold, and taking out the optical element after pressing from the barrel mold;
    A hand holding mechanism for holding the suction hand in a horizontal state;
    A drive unit that drives the suction hand via the hand holding mechanism,
    The optical element press molding apparatus according to claim 1, wherein the hand holding mechanism holds the suction hand by a plurality of elastic rubber members.
14. A suction hand for moving the inside of the housing and placing the glass material on the molding surface of the lower mold in the barrel mold, and taking out the optical element after pressing from the barrel mold;
    A hand holding mechanism for holding the suction hand in a horizontal state;
    A drive unit that drives the suction hand via the hand holding mechanism,
    The optical element press molding apparatus according to claim 1, wherein the hand holding mechanism is guided in a vertical direction by a linear guide.

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