JP4710482B2 - Injection needle, injection needle manufacturing method, and synthetic resin molding manufacturing method - Google Patents

Description

  The present invention relates to an injection needle for injecting a synthetic resin raw material when manufacturing a synthetic resin, a method for manufacturing the injection needle, and a method for manufacturing a synthetic resin molding.

  2. Description of the Related Art Conventionally, a lens manufacturing apparatus that manufactures a lens such as glasses with a synthetic resin is known (see, for example, Patent Document 1).

  The device described in Patent Document 1 is a manufacturing apparatus that manufactures a plastic lens by injecting a raw material of the plastic lens into a molding mold.

  The molding mold used in this manufacturing apparatus has a glass mold with a convex lens molding surface and a glass mold with a concave lens molding surface at a predetermined interval. These glass molds are arranged so as to face each other, and the outer periphery of these glass molds is formed by winding with an adhesive tape.

  Then, an injection hole is provided in the adhesive tape of the molding mold, the molding mold is arranged so that the injection hole is located above, the injection needle is inserted into the injection hole, and the raw material is aligned along the axis of the injection needle. To produce plastic lenses. This injection needle has a structure in which the tip is cut in a direction inclined with respect to the axial center in order to pass through the injection hole of the adhesive tape.

Japanese Patent Laid-Open No. 10-264180 (refer to pages 2 to 7 and FIGS. 1 to 5)

  By the way, in the conventional manufacturing apparatus like patent document 1, in order to insert the injection needle into the injection hole of the adhesive tape, the tip is cut obliquely, and the raw material is the axial direction of the injection needle, that is, the vertical direction. Injected in the direction. However, when the raw material is poured in the vertical direction simply by inserting the injection needle in this way, an air pocket may be formed between the upper end of the convexly curved lens molding surface and the adhesive tape because the raw material has viscosity. There is. When such air pockets become large, not only the appearance of the lens is deteriorated, but also the performance of the lens is lowered, and there is a problem that it must be treated as a defective product.

  An object of the present invention is to provide an injection needle, an injection needle manufacturing method, and a synthetic resin molding manufacturing method that reduce air accumulation.

The injection needle of the present invention is provided such that a tip can be inserted into a cavity formed by winding the outer periphery of a mold having a pair of molding surfaces facing each other with a tape, and a synthetic resin molded product is formed inside the mold. the raw material a injection needle for injecting the injection tip is formed to project from the tubular body for injecting the raw material of the synthetic resin molded product by applying to one of the molding surfaces of the pair of molding surfaces, said injection The distal end portion includes a first side surface provided on the one molding surface side, and a second side surface provided on the other molding surface side so as to face the first side surface, and the second side surface includes The guide piece is formed so as to protrude from the first side surface toward the inside of the mold, and has a guide piece formed at the tip thereof to protrude toward the one molding surface side at a predetermined angle. .

  According to this invention, the injection tip is formed on the injection needle so as to inject the raw material of the synthetic resin molded product against one of the pair of molding surfaces. As a result, the raw material of the synthetic resin molding injected into the mold hits one molding surface and flows on the upper side along the surface of the one molding surface. Therefore, even when the injection into the mold is completed, that is, when the mold is almost filled with the raw material of the synthetic resin molding, the raw material reaches the upper side of the one molding surface and air accumulation is reduced. Therefore, the appearance of the synthetic resin molded product can be improved, and the deterioration in performance and the increase in defect rate can be suppressed.

  According to the present invention, the injection tip portion of the injection needle includes the guide piece that protrudes from the second side surface toward the one molding surface. Thereby, the raw material of the synthetic resin molding can be applied to the guide piece and the injection direction can be easily directed to one molding surface side. Therefore, air accumulation can be easily prevented with a simple configuration, and the defective rate of the synthetic resin molded product to be produced can be reduced, thereby suppressing performance degradation.

  Furthermore, in the injection needle of the present invention, it is preferable that the guide piece is formed by being bent at an inclination angle of 40 ° to 55 ° with respect to the second side surface.

  According to this invention, the guide piece is formed to be inclined at an inclination angle of 40 ° to 55 ° with respect to the second side surface. As a result, the raw material of the synthetic resin molding can be reliably applied to the molding surface and can be pushed upward along the molding surface. In particular, when a mold for molding a lens used in glasses or a camera is used as the synthetic resin molding, the distance between the pair of molding surfaces is a small dimension corresponding to the limited lens thickness. In such a case, if the inclination angle of the guide piece is smaller than 40 °, the injected raw material does not hit one molding surface or hits the lower side of one molding surface. The raw material does not reach the upper end of the molding surface, and there is a risk that the air pocket will increase. Further, when the inclination angle of the guide piece is larger than 55 °, the raw material of the synthetic resin molding is a fluid having viscosity, and since the guide piece is present, the flow of the raw material is hindered and the manufacturability is deteriorated, Cause an error.

  In the injection needle of the present invention, the guide piece has a length of a perpendicular line dropped from the tip thereof onto the extended surface of the second side surface, and is a distance between the first side surface and the second side surface. It is preferably formed so as to be 0.6 times to 1.0 times.

  According to the present invention, the distance from the tip of the guide piece to the second side surface is formed to be 0.6 to 1.0 times the distance between the first side surface and the second side surface. . Here, when the distance from the tip of the guide piece to the second side surface is smaller than 0.6 times the distance between the first side surface and the second side surface, it is possible to change the injection direction of the raw material with the guide piece. It becomes difficult, and the undiluted solution flows down as it is without hitting one of the molding surfaces. On the other hand, if the distance from the tip of the guide piece to the second side surface is larger than 1.0 times the distance between the first side surface and the second side surface, there is a possibility that an air pocket may be formed on the lower side of the guide piece. Because the tip of the guide piece protrudes from the first side to one molding surface side, when the injection needle is pulled out from the mold after the raw material is injected, the raw material of the synthetic resin molded product is scraped off, and bubbles may be generated. There is a risk that the appearance will be deteriorated. On the other hand, when the distance from the tip of the guide piece to the second side surface is 0.6 to 1.0 times the distance between the first side surface and the second side surface, synthetic resin molding It is possible to favorably guide the raw material of the product to the one molding surface side, and to prevent the occurrence of air pockets.

  In the injection needle manufacturing method for manufacturing the injection needle of the present invention, one side surface of the cylindrical main body having a pair of side surfaces facing each other is formed to protrude from the other side surface, and the tip of the one side surface is formed. The guide piece is formed by bending the second side face by a predetermined angle.

  According to this invention, one side surface of the cylindrical main body is formed so as to protrude from the other side surface, and the leading end of the one side surface thus formed is bent to the other side surface by a predetermined angle to thereby guide the guide piece. Forming. Thereby, it becomes possible to manufacture the injection needle provided with the guide piece easily by a simple process.

Further, the synthetic resin molded product manufacturing method of the present invention, a pair of synthetic resin molded product manufacturing method by inserting an injection needle into a mold having a molding surface for injecting raw material of synthetic resin molded material, which are opposite to each other, wherein The injection needle is formed such that an injection tip portion for injecting a raw material of the synthetic resin molded product against one molding surface of the pair of molding surfaces is projected from the cylindrical body, and the injection tip portion is formed of the one of the molding surfaces. A first side surface provided on the molding surface side; and a second side surface provided on the other molding surface side so as to face the first side surface, wherein the second side surface is formed from the first side surface. A guide piece that is formed to protrude toward the inner side of the mold and that protrudes at a predetermined angle toward the one molding surface side at the tip, and is formed on one molding surface of the pair of molding surfaces. Against the raw material at least diagonally And butterflies.

According to this invention, the raw material is applied to one of the molding surfaces at least obliquely, whereby a part of the raw material is swept upward along the molding surface. Accordingly, even in the raw material injection stage, the raw material reaches the upper end of one of the molding surfaces, and the amount of air pool can be reduced. Accordingly, it is possible to prevent the performance of the synthetic resin molded product from being deteriorated and the appearance from being deteriorated, and to reduce the defect rate.
Moreover, according to this invention, the injection | pouring front-end | tip part of the injection needle is provided with the guide piece which protrudes toward one molding surface from a 2nd side surface. Thereby, the raw material of the synthetic resin molding can be applied to the guide piece and the injection direction can be easily directed to one molding surface side. Therefore, air accumulation can be easily prevented with a simple configuration, and the defective rate of the synthetic resin molded product to be produced can be reduced, thereby suppressing performance degradation.

[Configuration of lens manufacturing equipment]
Hereinafter, a lens manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view schematically showing a schematic configuration of a lens manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an outline of a molding mold for a plastic lens using a tape molding method. FIG. 3 is a perspective view schematically showing an injection tip portion of the injection needle. FIG. 4 is a side view of the injection tip of the injection needle. FIG. 5 is a cross-sectional view of the injection tip of the injection needle. FIG. 6 is a schematic view schematically showing the vicinity of an injection needle when a synthetic resin raw material is injected into a molding mold, (A) is a sectional view at the start of injection of the synthetic resin raw material, and (B) is a synthetic resin. Sectional drawing at the time of completion | finish of injection | pouring of a raw material, (C) is the top view which looked at the molding mold at the time of completion | finish of synthetic resin injection | pouring from the upper direction.

  In FIG. 1, reference numeral 100 denotes a lens manufacturing apparatus as a synthetic resin molding manufacturing apparatus. The lens manufacturing apparatus 100 is an apparatus that manufactures plastic lenses used for glasses, telescopes, camera lenses, and the like. In addition, although demonstrated using the lens manufacturing apparatus 100 which manufactures a plastic lens as one embodiment of this invention, this invention may be applied to the synthetic resin manufacturing apparatus which manufactures another synthetic resin molding. The lens manufacturing apparatus 100 includes a molding mold installation unit 10, a raw material supply suction unit 20, a control device 30, a suction raw material storage unit 40, and a raw material supply device 50.

  A plurality of mold holding portions 11 are disposed in the molding mold setting portion 10, and a molding mold 12 as a mold is held by these mold holding portions 11.

  The molding mold 12 includes a convex lens molding surface 13 as one molding surface having a convex surface on one side and a concave mold as the other molding surface having a concave surface on one side. Lens molding surface 14. In this molding mold 12, the convex surface of the convex lens molding surface 13 and the concave surface of the concave lens molding surface 14 are arranged to face each other at a predetermined interval, and the outer periphery of these lens molding surfaces 13, 14. The adhesive tape 15 is wound around the entire circumference of the surface. A cavity 16 is formed in a space surrounded by the pair of lens molding surfaces 13 and 14 and the adhesive tape 15.

  In addition, an injection port (not shown) for injecting a molten synthetic resin that is a raw material of at least one plastic lens is formed in a part of the adhesive tape 15. The injection port may be formed after the molding mold 12 is held by the mold holding unit 11 and attached to the molding mold installation unit 10, and is formed on a part of the adhesive tape 15 when the molding mold 12 is molded. It may be formed by drilling. The diameter of the injection port is not particularly limited, but may be any size as long as the injection needle can be inserted according to the diameter of the tip of the injection needle.

  The raw material supply / suction unit 20 injects a molten synthetic resin (hereinafter referred to as a synthetic resin raw material), which is a raw material of the plastic lens, into the cavity 16 of the molding mold 12 installed in the molding mold installation unit 10. The raw material supply / suction unit 20 sucks and removes the synthetic resin raw material overflowing from the injection port of the molding mold 12. The raw material supply / suction unit 20 is attached to the lens manufacturing apparatus 100 so as to be movable back and forth with respect to the molding mold 12. The raw material supply / suction unit 20 includes a supply unit main body 21, an injector 22 in the supply unit main body 21, and a suction unit 23 that sucks the synthetic resin raw material overflowing from the molding mold 12. As a synthetic resin raw material used in this embodiment, for example, a polymerizable composition containing a polythiol compound having two or more mercapto groups and a compound having a functional group that reacts with a mercapto group in the molecule is polymerized and cured. A plastic lens substrate can be used.

  The supply unit main body 21 is connected to the raw material supply device 50 and guides the synthetic resin raw material introduced from the raw material supply device 50 to the injector 22. The injector 22 includes an injection needle 25 that can be inserted into the injection port of the molding mold 12, and injects the synthetic resin material sent from the supply unit main body 21 into the molding mold 12. A detailed description of the injection needle 25 will be described later.

  The suction portion 23 is formed in a tubular shape, and is provided so that the tip of the tube is positioned in the vicinity of the injection port. The suction unit 23 is connected to the suction raw material storage unit 40, sucks the synthetic resin raw material overflowing from the inlet, and sends it out to the suction raw material storage unit 40.

  The control device 30 is connected to the supply unit main body 21 and the measurement station 31. The measurement station 31 measures the supply amount of the synthetic resin raw material supplied from the raw material supply device 50 and the suction amount of the synthetic resin raw material sucked by the suction unit 23, and sends a signal based on the measured value to the control device 30. input. And the control apparatus 30 adjusts the injection quantity of the synthetic resin raw material inject | poured into the injector 22 from the supply part main body 21 based on the signal input from the measurement station 31. FIG.

  Further, when the molding mold 12 is installed in the molding mold installation unit 10, the control device 30 advances and retracts the raw material supply / suction unit 20 with respect to the molding mold 12, and inserts the injection needle 25 into the molding mold 12. Insert into the entrance. Furthermore, when the suction amount of the synthetic resin raw material in the suction unit 23 exceeds a predetermined value, the control device 30 moves the raw material supply suction unit 20 in a direction away from the injection port based on the signal input from the measurement station 31. In addition, the supply amount of the synthetic resin raw material introduced into the injection unit 22 is reduced or stopped.

  The suction raw material storage unit 40 includes a storage unit 41 that stores the synthetic resin raw material sucked by the suction unit 23, and a lid 42 that is provided in the storage unit 41. The saving part 41 has an opening partly, and a lid part 42 is provided in the opening part. And the inside of the storage part 41 is sealed by this lid part 42. Further, the lid portion 42 is formed with two window portions that communicate the inside and the outside of the saving portion 41, one of these window portions being connected to the suction portion 23, and the other window portion A pump pipe 43 is inserted through the pipe. This pump pipe 43 is connected to a vacuum pump (not shown), and the inside of the storage part 41 is evacuated by this vacuum pump, so that the suction part 23 can remove the synthetic resin material overflowing from the injection port with a predetermined suction force. Suction. In addition, the raw material of the plastic lens stored in the storage unit 41 may be dissolved and reused, or may be discarded.

  The raw material supply device 50 is connected to the supply unit main body 21 and supplies a molten synthetic resin raw material to be a raw material for the plastic lens. The raw material supply device 50 may be configured to adjust the supply amount of the plastic lens raw material supplied by the raw material supply suction unit 20 under the control of the control device 30. Further, the raw material supply device 50 may be configured to always supply the synthetic resin raw material to the raw material supply suction unit 20 at a constant pressure and adjust the supply amount of the synthetic resin raw material in the supply unit main body 21.

[Configuration of injection needle]
Next, the injection needle 25 provided in the injector 22 of the raw material supply / suction unit 20 will be described with reference to FIGS.

  The injection needle 25 is attached to the injector 22 and is provided so that the tip side can be inserted into the injection port at a position facing the molding mold 12. The injection needle 25 includes a cylindrical main body 251 whose base end on the injector side is attached to the injector 22, and a synthetic resin material is placed in the cavity 16 of the molding mold 12 at the distal end of the cylindrical main body 251. An injection tip portion 26 for injection is formed. In addition, as shown in FIGS. 3 to 5, the cylindrical main body 251 is formed in a substantially rectangular cross section in the present embodiment.

  The injection tip portion 26 is formed continuously with the cylindrical main body 251, and has a smaller cross-sectional area perpendicular to the axial direction than the cylindrical main body 251. The injection tip 26 is formed in a substantially rectangular shape, and has a convex facing surface 261A as a first side facing the convex lens molding surface 13 of the molding mold 12, and a concave lens molding surface of the molding mold 12. 14, and a concave facing surface 261 </ b> B as a second side surface facing to 14. The injection tip 26 is formed such that the concave facing surface 261B protrudes toward the cavity 16 from the convex facing surface 261A. An injection opening 262 that is inclined with respect to the axis of the injection needle 25 is formed at the tip of the injection tip 26 on the cavity 16 side from the tip of the convex facing surface 261A toward the tip of the concave facing surface 261B. Has been. In the present embodiment, the inclination angle θ2 of the injection opening 262 with respect to the convex facing surface 261A is set to 30 °, but is not particularly limited to this, and can be set to any angle. is there.

  A guide piece 263 that is inclined at a predetermined inclination angle θ1 with respect to the extended surface of the concave facing surface 261B and protrudes toward the cavity 16 is formed at the tip of the concave facing surface 261B. When the synthetic resin raw material is introduced from the injector 22 into the injection needle 25 and the synthetic resin raw material is discharged from the injection opening 262, the guide piece 263 causes the synthetic resin raw material to be removed from the convex lens molding surface 13. Guide to be injected towards the side. The inclination angle θ1 formed by the guide piece 263 and the concave facing surface 261B is preferably set to 40 ° to 55 °. If the inclination angle is within this range, the synthetic resin discharged from the injection opening 262 is used. The raw material can be guided to the side surface of the convex lens molding surface 13. Here, when the inclination angle θ1 with respect to the concave facing surface 261B of the guide piece 263 is smaller than 40 °, the synthetic resin raw material released from the injection opening 262 cannot reach the side surface of the convex lens molding surface 13 and is vertical. Since it is discharged in the direction, there is a possibility that an air pocket may be formed between the convex lens molding surface 13 and the adhesive tape 15 that can be placed on the upper end side of the molding mold. Further, when the inclination angle θ1 is larger than 55 °, it is difficult to secure the flow rate of the synthetic resin material discharged from the injection opening 262, and an error may be output at the measurement station 31. On the other hand, when the inclination angle θ1 of the guide piece 263 with respect to the concave facing surface 261B is 40 ° to 55 °, the synthetic resin raw material discharged from the injection opening 262 as shown in FIG. Is guided to the convex lens molding surface 13 by the guide piece 263, is pushed down to the adhesive tape 15 at the upper end along the convex lens molding surface 13, and then flows downward.

  Furthermore, the length dimension b of the perpendicular from the leading end of the guide piece 263 to the inner peripheral extension surface of the concave facing surface 261B and the inner peripheral surface of the convex facing surface 261A at the injection leading end 26 to the concave facing surface 261B. The guide piece 263 is formed so that the ratio (b / a) to the distance dimension a to the inner peripheral surface is 0.6 to 1.0, that is, the distance dimension b is 0. It is preferable that the guide piece 263 is formed to be 6 to 1.0 times. Here, when the ratio (b / a) of the length dimension b and the length dimension a is smaller than 0.6, the induction of the synthetic resin raw material released from the injection opening 262 becomes insufficient, and the synthetic resin The raw material does not reach the convex lens molding surface 13 and flows down in the vertical direction. Further, when the ratio (b / a) is larger than 1.0, the guide piece 263 is too long, the flow of the synthetic resin raw material to the lower side is hindered, and bubbles are formed in the lower part of the guide piece 263. There is a risk that. In addition, when the molding mold 12 is filled with the synthetic resin raw material and the injection needle 25 is extracted to the outside, if the guide piece 263 protrudes more toward the convex lens molding surface 13 than the convex facing surface 261A, There is also a risk of scraping out the synthetic resin raw material. On the other hand, when the guide piece 263 is formed so that the ratio (b / a) is 0.6 to 1.0, the synthetic resin raw material is guided to the convex lens molding surface 13 to form the convex lens. After being pushed down along the surface 13 to the adhesive tape 15 at the upper end, it flows down and no bubbles are generated below the guide piece 263.

[Production method of injection needle]
A method for manufacturing the injection needle 25 as described above will be described with reference to FIG. 7A and 7B are diagrams showing a manufacturing process of the injection needle, where FIG. 7A is a cross-sectional view before cutting the tip of the injection needle, FIG. 7B is a cross-sectional view after cutting the tip of the injection needle, and FIG. FIG.

  In FIG. 7, in order to create the injection needle 25 as described above, first, the concave facing surface 261B is formed on the tip of the cylindrical injection tip 26 having a substantially rectangular cross section as shown in FIG. The projection is cut from the convex facing surface 261A and the inclination angle θ2 between the convex facing surface 261A and the opening surface of the injection opening 262 is 30 °. At this time, the injection tip 26 is cut so that the guide piece 263 protrudes by a predetermined dimension from the boundary between the concave facing surface 261B and the injection opening 262.

Next, the guide piece 263 is bent toward the convex facing surface 261A so that the inclination angle θ1 with the concave facing surface 261B is 40 ° to 55 °.
Then, the length dimension a of the convex facing surface 261A and the concave facing surface 261B of the injection tip portion 26 and the length dimension b of the perpendicular dropped from the tip of the guide piece 263 to the extended surface of the concave facing surface 261B. The tip of the guide piece 263 is cut so that the length ratio (b / a) is 0.6 to 1.0. Thus, the injection needle 25 having the injection tip portion 26 is formed.

[Operation of lens manufacturing equipment]
Next, injection of the synthetic resin raw material in the operation of the lens manufacturing apparatus 100 will be described with reference to FIG.

  When the molding mold 12 is installed in the molding mold installation unit 10 of the lens manufacturing apparatus 100, the injection port forming apparatus (not shown) of the lens manufacturing apparatus 100 opens the injection port at a position facing the injection needle 25 of the injector 22. Form. And the control apparatus 30 moves the raw material supply suction part 20 with respect to the injection port of this shaping | molding mold 12, and inserts the injection needle 25 in an injection port.

  Thereafter, the synthetic resin raw material is supplied from the raw material supply device 50 to the supply unit main body 21 and injected from the injection needle 25 into the cavity 16 of the molding mold 12. At this time, since the synthetic resin raw material is injected toward the convex lens molding surface 13 as shown in FIG. 6A by the guide piece 263 of the injection needle 25, an adhesive tape is formed along the convex lens molding surface 13. After being pushed down to 15, it flows down to the lower side. Thereby, the synthetic resin raw material is also poured into the gap at the boundary between the convex lens molding surface 13 of the molding mold 12 and the adhesive tape 15 as shown in FIGS. 6B and 6C.

[Effects of lens manufacturing equipment]
In the lens manufacturing apparatus 100 of the above-described embodiment as described above, the injection tip portion 26 for injecting the synthetic resin material onto the injection needle 25 against the convex lens molding surface 13 is formed. For this reason, the synthetic resin raw material injected into the molding mold 12 hits the convex lens molding surface 13 and can be swept upward along the surface. Therefore, at the stage where the synthetic resin raw material injection into the molding mold 12 is completed, the synthetic resin raw material reaches the gap at the boundary with the adhesive tape 15 at the upper end of the convex lens molding surface 13, thereby reducing air accumulation. Therefore, the appearance of the lens can be improved, the performance of the lens can be prevented from being lowered, and the defective rate can be reduced.

  In addition, the injection distal end portion 26 is inclined at a predetermined angle θ1 with respect to the concave facing surface 261B at the distal end of the concave facing surface 261B formed to protrude toward the cavity 16 from the convex facing surface 261A. A guide piece 263 is formed. For this reason, the synthetic resin raw material introduced into the injector 22 can be poured into the direction of the convex lens molding surface 13 obliquely while being applied to the guide piece 263. Therefore, the synthetic resin raw material can be easily applied to the convex lens molding surface 13 obliquely with the injection needle 25 having a simple structure and pushed upward along the surface, thereby preventing air accumulation.

  Further, the guide piece 263 is formed to be inclined at an inclination angle of 40 ° to 55 ° with respect to the concave facing surface 261B. For this reason, it is possible to more reliably apply the synthetic resin raw material to the convex lens molding surface 13 and push it upward along the molding surface, thereby more reliably reducing the defect rate.

  Then, the ratio of the distance b from the leading end of the guide piece 263 to the concave facing surface 261B and the distance a between the opposing inner peripheral surfaces of the convex facing surface 261A and the concave facing surface 261B of the injection leading end portion 26. It is formed so that (b / a) is 0.6 to 1.0. For this reason, the synthetic resin raw material can be favorably guided to the convex lens molding surface 13 side by the guide piece 263, and the occurrence of air pockets can be satisfactorily prevented.

  The injection needle 25 injects a synthetic resin raw material so as to be obliquely applied to the convex lens molding surface 13 that is convexly curved toward the concave lens molding surface 14 side. When such a convex lens molding surface 13 is used, the synthetic resin material having viscosity is difficult to reach especially in the gap at the boundary with the adhesive tape 15 at the upper end portion, and an air pocket is generated and cheap. However, as in the present embodiment, By using the injection needle 25, the synthetic resin raw material can be applied obliquely to the surface of the convex lens molding surface 13 as described above. Then, the synthetic resin raw material hitting the surface of the convex lens molding surface 13 is pushed upward along the surface of the convex lens molding surface 13 and then flows downward. Therefore, the synthetic resin raw material can be reached even by pushing the synthetic resin material into the gap between the convex lens molding surface 13 and the adhesive tape 15 at the upper end of the molding mold 12, and an air pocket generated at the upper end of the molding mold is generated. The amount can be phenomenon.

  When the injection needle 25 as described above is manufactured, the concave facing surface 261B of the injection tip portion 26 is formed so as to protrude toward the cavity 16 from the convex facing surface 261A, and this concave facing surface 261B is formed. The guide piece 263 is formed by inclining the front end of the guide plate 261 at a predetermined angle toward the convex facing surface 261A. For this reason, the injection | pouring front-end | tip part 26 which has the induction | guidance | derivation piece 263 at the front-end | tip of the injection | pouring needle 25 can be easily produced with a simple process, and the injection | pouring needle | hook 25 with favorable productivity also can be provided cheaply.

[Other embodiments]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  For example, in the embodiment described above, the injection tip portion 26 in which the guide piece 263 is formed at the tip of the injection needle 25 is provided, but the present invention is not limited to this. For example, the tip of the injection needle 25 may be formed in a cylindrical shape with a closed bottom, and an opening may be formed on the side surface of the cylinder facing the convex lens molding surface 13. Even in such a configuration, the synthetic resin raw material can be applied so as to be applied to the convex lens molding surface 13.

  Alternatively, a conventional injection needle having an opening in the axial direction of the tip may be inserted at least obliquely from the injection port of the molding mold 12 toward the convex lens molding surface 13. Even with such a configuration, the synthetic resin raw material can be applied at least obliquely to the convex lens molding surface 13, and the synthetic resin raw material is spaced along the surface of the convex lens molding surface 13 with the upper adhesive tape 15. It is possible to prevent air accumulation by flushing away.

  Moreover, in the said embodiment, although the cylindrical main body 251 showed the example formed in the cross-sectional rectangle, it may be formed in other shapes, such as circular cross-section and cross-sectional ellipse, for example. In addition, although the injection tip portion 26 is also formed to have a substantially rectangular cross section, it may be formed to have a circular cross section, for example. Even in this case, the side surface of the injection tip 26 facing the concave lens molding surface 14 is protruded toward the cavity 16 rather than the side surface facing the convex lens molding surface 13, and the tip is directed toward the convex lens molding surface 13. In this way, it is possible to obtain an effect of preventing air accumulation well as in the above embodiment.

  Further, in the manufacturing method of the injection needle 25, after the cylindrical injection tip portion 26 is cut at the inclination angle θ2 so as to be in the state shown in FIG. 7B, the convex facing surface 261A and the concave facing surface 261B. And the other two side surfaces forming the injection opening 262 may be formed with a notch on the concave facing surface 261B side. In this case, a notch is provided so as to be inclined with the concave facing surface 261B at an inclination angle θ1, and the guide piece 263 is bent along the notch. In such an injection needle manufacturing method, when the guide piece 263 is bent, the shape of both side ends of the guide piece 263 is not collapsed, and the guide piece 263 that can guide the synthetic resin raw material to the convex lens molding surface 13 more accurately is provided. Can be created.

  Furthermore, in the above-described embodiment, the configuration in which the synthetic resin material is applied at least obliquely to the convex lens molding surface 13 is shown, but the present invention is not limited to this. The convex lens molding surface 13 has been described in the above example in order to achieve a particularly effective effect as described above because air can easily be trapped particularly between the adhesive tape 15. The synthetic resin raw material may be injected so as to be at least obliquely applied to the molding surface of the lens molding surface, the flat lens molding surface, and the molding surface of other synthetic resin moldings.

  In the above embodiment, the example in which the inclination angle θ1 of the guide piece 263 is set to 40 ° to 55 ° has been described, but the angle may be appropriately determined depending on the thickness dimension of the lens. For example, when the thickness dimension of the lens is extremely thin, even if the inclination angle θ1 of the guide piece 263 is 40 °, the synthetic resin raw material strikes the convex lens molding surface 13 from an oblique direction and is swept away from the surface. Can be prevented. In addition, when the lens thickness is thick, the injection speed of the synthetic resin material may be increased to a speed at which the flow of the guide piece 263 is not hindered after the inclination angle θ1 of the guide piece 263 is set to 55 ° or more. Good.

  In addition, the specific structure and procedure for carrying out the present invention can be changed as appropriate to other structures and the like within the scope of achieving the object of the present invention.

  An experiment was conducted to measure the defect rate when a lens was manufactured using the lens manufacturing apparatus 100 of the present invention described in the above embodiment. The inclination angle θ2 of the injection opening 262 of the injection needle 25 with respect to the convex facing surface 261A was 30 °, and the injection rate of the synthetic resin raw material was 4 cc / s. Then, the inclination angle θ1 of the guide piece 263 with respect to the concave facing surface 261B is changed from 30 °, 40 °, 45 °, 48 °, 50 °, 55 °, and 60 ° from the tip of the guide piece 263. When the ratio (b / a) of the distance dimension b to the inner peripheral extension surface of the concave facing surface 261B and the distance dimension a from the convex facing surface 261A to the concave facing surface 261B at the injection tip 26 is changed (b / a) That is, the defect rates were measured for cases where b / a was changed to 0.3, 0.6, 0.9, 1.0, and 1.1. In addition, in the molded lens, if the size of chipping due to air accumulation is 2.0 mm or less in the central direction and 3.0 mm or less in the outer peripheral direction, it is a non-defective product. As the larger one, the defective rate was measured as a defective product.

  FIG. 8 shows the results of Example 1. As shown in FIG. 8, when the inclination angle θ1 is 45 ° to 55 ° and the distance dimension ratio (b / a) is 0.6 to 1.0, the defect rate is 3.0% or less. It was confirmed that In particular, when the inclination angle θ1 with respect to the concave facing surface 261B of the guide piece 263 is 45 ° to 48 ° and the distance dimension ratio (b / a) is 0.6 to 0.9, the defect rate is the lowest and optimal. It was confirmed that the lens could be molded.

  An experiment was conducted to measure the defect rate when a lens was manufactured using the lens manufacturing apparatus 100 of the above embodiment. Similarly to the first embodiment, the inclination angle θ2 of the injection opening 262 of the injection needle 25 with respect to the convex facing surface 261A is 30 °, and the distance dimension b from the tip of the guide piece 263 to the concave facing surface 261B and the concave The ratio (b / a) to the distance dimension a from the side facing surface 261B to the convex facing surface 261A was set to 0.6, and the injection rate of the synthetic resin raw material was 4 cc / s. Then, the base curve of the convex portion of the convex lens molding surface 13 of the molding mold 12 is changed, that is, the bending rate of the molded lens is +3.0 diopter, +1.0 diopter, −0.25 diopter, − The convex lens molding surface 13 is appropriately changed so as to be 6.00 diopter and −9.50 diopter, and the inclination angle θ1 with respect to the concave facing surface 261B of the guide piece 263 is changed in each molding mold 12 to be defective. A rate measurement experiment was conducted. The inclination rate θ1 was set to 30 °, 35 °, 45 °, 48 °, and 50 °, respectively, and the defect rate measurement experiment was performed.

  FIG. 9 shows the results of Example 2. As shown in FIG. 9, it was confirmed that the defect rate is less than 1.0% when the inclination angle θ1 of the guide piece 263 is 45 ° to 55 ° corresponding to all the base curves. Further, in the molding mold 12 for molding a lens having a bending rate of −0.25 diopter, −6.00 diopter, and −9.50 diopter, the defect rate is lowered, so that the convex lens It was confirmed that the defect rate can be reduced not only on the molding surface but also on the concave lens molding surface and the planar lens molding surface.

  INDUSTRIAL APPLICABILITY The present invention can be used for a lens used in glasses, a camera, a telescope, a watch, and the like, and an injection needle for injecting a synthetic resin in an apparatus for manufacturing other synthetic resin moldings.

It is a top view which shows typically schematic structure of the lens manufacturing apparatus which concerns on one embodiment of this invention. It is sectional drawing which shows the outline of the mold for plastic lens shaping | molding using the tape mold method. It is a perspective view which shows the outline of the injection | pouring front-end | tip part of an injection needle. It is a side view of the injection | pouring front-end | tip part of an injection needle. It is sectional drawing of the injection | pouring front-end | tip part of an injection needle. It is the schematic which shows typically the injection needle vicinity at the time of inject | pouring the synthetic resin raw material to the molding mold, (A) is sectional drawing at the time of the injection start of a synthetic resin raw material, (B) is completion | finish of injection | pouring of the synthetic resin raw material (C) is the top view which looked at the molding mold at the time of completion | finish of synthetic resin injection | pouring from upper direction. It is a figure which shows the manufacture process of an injection needle, (A) is sectional drawing before injection needle tip cutting | disconnection, (B) is sectional drawing after injection needle tip cutting | disconnection, (C) is sectional drawing after tip shaping | molding of an injection needle. It is. It is a figure which shows the result of Example 1. It is a figure which shows the result of Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Mold for shaping | molding as a type | mold 13 ... Convex-type lens shaping | molding surface as one shaping | molding surface 25 ... Injection | pouring needle 26 ... Injection | pouring front-end | tip part 100 ... Lens manufacturing apparatus 251 ... Cylindrical main body 261A ... Convex facing surface 261B as the first side surface ... Concave facing surface 263 as the second side surface 263 ... Guide piece

Claims (5)

An injection needle for injecting a raw material of a synthetic resin molding into the mold, the tip of the mold having a pair of molding surfaces facing each other is provided in a cavity formed by winding the outer periphery with a tape. Because
An injection tip portion for injecting the raw material of the synthetic resin molding against one molding surface of the pair of molding surfaces is formed to protrude from the cylindrical body ,
The injection tip includes a first side surface provided on the one molding surface side, and a second side surface provided on the other molding surface side to face the first side surface,
The second side surface includes a guide piece formed to protrude from the first side surface toward the inner side of the mold and project at a predetermined angle toward the one molding surface side at the tip. An injection needle characterized by that. The injection needle according to claim 1 ,
The injection needle is formed by bending the guide piece at an inclination angle of 40 ° to 55 ° with respect to the second side surface. The injection needle according to claim 1 or 2 ,
In the guide piece, the length of a perpendicular line dropped from the tip of the guide piece onto the extended surface of the second side surface is 0.6 to 1.0 times the distance between the first side surface and the second side surface. An injection needle characterized by being formed so as to be doubled. A injection needle manufacturing method for manufacturing an injection needle according to any one of claims 1 to 3,
A cylindrical main body having a pair of side surfaces facing each other is formed such that one side surface protrudes from the other side surface, and the leading end of this one side surface is bent to the other side surface by a predetermined angle to form a guide piece. An injection needle manufacturing method characterized by: A synthetic resin molding production method for injecting a raw material of a synthetic resin molding by inserting an injection needle into a mold having a pair of molding surfaces facing each other ,
The injection needle is formed such that an injection tip portion for injecting the raw material of the synthetic resin molded product against one molding surface of the pair of molding surfaces protrudes from the cylindrical body,
The injection tip includes a first side surface provided on the one molding surface side, and a second side surface provided on the other molding surface side to face the first side surface,
The second side surface includes a guide piece formed to protrude from the first side surface toward the inner side of the mold and project at a predetermined angle toward the one molding surface side at the tip. ,
The synthetic resin molded product manufacturing method, wherein the raw material is applied at least obliquely to one molding surface of the pair of molding surfaces.

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