JP5362386B2 - Gate cutting method and lens receiving jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately cut a gate in a simple method. <P>SOLUTION: A control section 33 controls the drive of a receiving jig movement mechanism 30 to move a receiving jig 29 slightly in the A direction so that the flange 21 peripheral surface 22 of a lens 12 is caught surely by a catching surface 38. By catching the peripheral surface 22 of the flange 21 on the catching surface 38, the position of the lens 12 is fixed, and the gate 17 is arranged in the A direction. The control section 33 controls the drive of the receiving jig movement mechanism 30 and controls the drive of a cutter movement mechanism 32 while giving a tensile stress smaller than its tensile strength to the gate 17 to move the receiving jig 29 in the A direction, so that a cutter 31 is moved in the arrow direction to cut the gate 17. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a gate cutting method for cutting a gate portion of a molded product, and a lens receiving jig for placing a lens when the gate portion is cut.

  Plastic lenses used for cameras and the like are produced by injection molding using a mold. In injection molding, a molten plastic material injected from a nozzle of an injection molding machine flows into a space (cavity) for molding a lens through a spool bush and a runner of a mold. The inlet (gate) to the cavity is a restricted gate that is narrower than the runner in terms of preventing backflow and lens separation.

  The injection-molded product is composed of spool bush portions, runner portions, gate portions, and lenses corresponding to the spool bush, runner, and gate, respectively. The lens is cut off by cutting the gate portion while holding the lens with a jig after molding the molded product (see, for example, Patent Document 1).

  On the lens cut off from the runner part, a gate mark remains on the cut surface obtained by cutting the gate part. This gate trace has an adverse effect when the lens is incorporated into an optical instrument. For this reason, the lens may be formed into a D-shape with a part of the outer peripheral surface cut out in consideration of the remaining gate trace. If the lens is formed in a D-shape, the gate mark is stored in the cutout range, and the lens can be accurately incorporated into the optical apparatus even if the gate mark remains.

Japanese Patent Application Laid-Open No. 08-025429

  However, even with a lens molded in a D-shape, the cutout range will be small if the diameter is small. Therefore, the gate part is accurately cut in order to fit the gate trace in the cutout range. It is necessary to reduce the trace. In addition, with the spread of compact cameras and camera-equipped mobile phones, the demand for plastic lenses having a small diameter of about 2 mm to 8 mm is increasing, so that a large amount of gate portions can be accurately cut in a short time. It is strongly desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a gate cutting method capable of accurately cutting a gate portion while being a simple method, and a lens receiving jig used in this method.

To achieve the above object, the gate cut method of the present invention, the gate cut method product unit through a gate portion is cut the gate portion of the injection molded article molded in the runner portion, receives the product portion It is mounted on a mounting surface of a jig, is a curved surface formed on the receiving jig and along the outer peripheral surface of the product portion, and the gate portion is placed when the product portion is mounted on the mounting surface. The product part and the runner part are moved away from each other in a state where the outer peripheral surface of the product part is hooked on the hooking surfaces located on both sides of the sandwiched part and the outer peripheral surface of the product part is hooked on the hooking surface. The gate part is cut by a cutter while pulling the gate part in a direction.

In the lens receiving jig of the present invention, the mounting surface on which the lens of the injection molded product in which the lens is formed on the runner portion via the gate portion is placed, and the lens and the runner portion are moved away from each other. A hooking surface for hooking the outer peripheral surface of the lens placed on the mounting surface when pulling the gate portion, the hooking surface is a curved surface along the outer peripheral surface of the lens, When the lens is placed on the placement surface, the lens is located on both sides of the gate portion .

Further, the side sandwiching the gate portion of the hook surface contiguous to the opposite side, Rukoto comprises a first guide surface for guiding said lens to said hooking surface is preferred.

Furthermore, it is preferable that the hooking surface and the first guide surface are smoothly continuous with each other .

Moreover, it is preferable that said 1st guide surface is a plane and the said mounting surface is a fan shape enclosed by the said hooking surface and said 1st guide surface .

Furthermore, the angle at which the mounting surface spreads is preferably 40 ° ± 20 ° .

The diameter of the lens is preferably 2mm or more 8mm or less.

Furthermore, it is preferable that the height of the hooking surface and the first guide surface is substantially the same as the thickness of the outer peripheral portion of the lens .

Moreover, it is preferable to provide the 2nd guide surface which continues above the said 1st guide surface and guides the said lens to the said mounting surface .

Furthermore, it is preferable that a concave portion for preventing buffering with the lens surface of the lens is formed on the mounting surface .

  According to the gate cutting method and the lens receiving jig of the present invention, the direction of the gate portion is surely orthogonal to the cutting direction of the cutter by setting the tension direction of the gate portion and the cutting direction of the cutter to be orthogonal to each other. The gate portion can be cut with high accuracy while being a simple method.

It is a front view which shows the gate cut apparatus which set the injection molded product. It is a top view which shows the gate cut apparatus which set the injection molded product. (A) is a top view which shows a lens receiving jig, (B) is sectional drawing which shows the IIIB-IIIB cross section in (A). It is a perspective view which shows a lens receiving jig. It is a perspective view which shows the lens receiving jig at the time of mounting the lens shape | molded by the runner part. It is a perspective view which shows the lens receiving jig of the state which mounted the lens shape | molded by the runner part. It is a perspective view which shows the lens receiving jig | tool at the time of cutting a gate part. It is a perspective view which shows the lens receiving jig of the state which mounted the lens cut | disconnected from the runner part.

  A gate cut device 11 shown in FIGS. 1 and 2 is used to separate the lens 12 from an injection molded product 13 in which a plurality of lenses (product parts) 12 are molded. The injection-molded product 13 is made of a transparent plastic molded by injection molding using a mold, and has a cylindrical rim having a diameter larger than that of the spool bush portion 14 in the middle of the cylindrical spool bush portion 14. Part 15 is molded. A lens 12 is molded through a gate portion 17 at the tip of each of the four runner portions 16 extending radially from the rim portion 15 at a pitch of 90 °. The gate portion 17 is formed so as to be parallel to the longitudinal direction of the runner portion 16.

  Each lens 12 includes a main body portion 20 having lens surfaces 18 and 19 and a flange portion 21 formed on the outer peripheral edge of the main body portion 20, and a portion of the outer peripheral surface 22 of the flange portion 21 is cut away. It is molded into a letter shape. A gate portion 17 is formed on the cut-out surface 23 cut out at a part of the outer peripheral surface 22. Each lens 12 is used as a part of a photographing lens incorporated in a camera-equipped mobile phone, and each diameter is equal to each other and is preferably 2 mm or more and 8 mm or less.

  The gate cut device 11 is provided with a holding base 25 that rotatably holds the injection molded product 13 at the lower end of the spool bush portion 14, a rotating mechanism 26 that rotates the holding base 25, and a holding base 25 that can be moved up and down. An elevating plate 27 and an elevating mechanism 28 for elevating the elevating plate 27 are provided.

  Further, the gate cut device 11 has a lens 12 placed thereon, a direction in which the placed lens 12 is moved away from the runner portion 16 and the opposite direction thereof (the left-right direction in FIGS. 1 and 2, that is, the A direction and the B direction). ) And a receiving jig moving mechanism 30 for moving the receiving jig 29 in the A direction and the B direction.

  Furthermore, the gate cutting device 11 includes a metal cutter 31 that cuts the gate portion 17 at the base on the lens 12 side, a direction orthogonal to the A direction (see FIG. 7), and the opposite direction. A cutter moving mechanism 32 that moves the cutter 31 and a control unit 33 that controls driving of the mechanisms 26, 28, 30, and 32 are provided. The elevating plate 27, the receiving jig 29, and the cutter 31 are each attached to a support base (not shown).

  The receiving jig 29 shown in FIGS. 3 (A), 3 (B) and 4 is made of mirror-finished stainless steel and includes a receiving portion 36 for receiving the lens 12. The receiving portion 36 is placed on the placing surface 37 when the lens 12 is placed on the flange portion 21 and the receiving jig 29 moves in the A direction (see FIGS. 1 and 2). The hooking surface 38 on which the outer peripheral surface 22 of the flange portion 21 of the lens 12 is hooked and the lens 12 mounted on the mounting surface 37 are guided to the hooking surface 38 when the receiving jig 29 moves in the A direction. The first guide surface 39 and the second guide surface 40 that guides the lens 12 to the mounting surface 37 when the lens 12 is mounted on the mounting surface 37.

  The hooking surface 38 is a curved surface along the outer peripheral surface 22 of the flange portion 21, and both sides sandwiching the gate portion 17 formed so as to be continuous with the lens 12 when the lens 12 is placed on the placement surface 37. It is formed perpendicular to the mounting surface 37 so as to be located in each of the above. The first guide surface 39 is a flat surface, and is formed perpendicular to the placement surface 37 so as to smoothly continue to the opposite side of the hooking surface 38 to the side sandwiching the gate portion 17. Each hook surface 38 and each first guide surface 39 are formed so that the height thereof is the same as the thickness of the flange portion 21 of the lens 12 (the outer peripheral portion of the lens 12).

  The mounting surface 37 has a fan shape surrounded by the hooking surfaces 38 and the first guide surfaces 39, and a concave portion 41 cut out in a fan shape is formed at the center thereof. The angle R1 of the mounting surface 37 spreading in a fan shape is preferably 40 ° ± 20 °, more preferably 30 ° ± 10 °, and most preferably 30 °. The angle R2 of the concave portion 41 spreading in a fan shape is preferably 10 ° ± 5 °, and more preferably 10 °. In this embodiment, the lens surface 19 on the side to be placed on the placement surface 37 is not a convex surface, but the lens surface 19 may be a convex surface. In this case, the concave portion 41 has the lens surface 19 and the placement surface 37. And prevent buffering.

  The second guide surface 40 is formed as an inclined surface so as to be continuous above each hooking surface 38 and each first guide surface 39.

  Next, a processing procedure of the gate cut device 11 shown in FIGS. 1 and 2 will be described. The injection-molded product 13 injection-molded with a mold is conveyed to the gate cut device 11 by a conveyance arm (not shown). The injection-molded product 13 conveyed to the gate cut device 11 is held at the lower end of the spool bushing portion 14 by the holding stand 25 and is run by the runner portion 16 by a runner holding portion (not shown) provided on the holding stand 25. Retained. At this time, the control unit 33 controls the elevating mechanism 28 so that the height of the elevating plate 27 is the height at which the lens 12 is separated from the receiving jig 29.

  The control unit 33 controls the drive of the rotation mechanism 26 to rotate the injection molded product 13 by rotating the holding base 25 so that any lens 12 is positioned directly above the receiving jig 29. And the control part 33 controls the drive of the raising / lowering mechanism 28, and descends the raising / lowering board 27 so that the lens 12 may be mounted in the receiving jig 29 (refer FIG. 5). The lens 12 is mounted on the mounting surface 37 by the flange portion 21.

  The control unit 33 controls the driving of the receiving jig moving mechanism 30 to slightly move the receiving jig 29 in the A direction so that the outer peripheral surface 22 of the flange portion 21 of the lens 12 is reliably hooked on the hooking surface 38. (See FIG. 6). When the outer peripheral surface 22 of the flange portion 21 is reliably hooked to the hooking surface 38, the position of the lens 12 is fixed and the gate portion 17 is along the A direction.

  The control unit 33 controls the driving of the receiving jig moving mechanism 30 to move the cutter while applying a tensile stress smaller than the tensile strength to the gate unit 17 so as to move the receiving jig 29 in the A direction. The gate of the gate 17 is cut by moving the cutter 31 in the direction of the arrow by controlling the driving of the mechanism 32 (see FIG. 7). When the gate portion 17 is cut, the lens 12 is separated from the runner portion 16 (see FIG. 8). The lens 12 separated from the runner portion 16 is recovered by a recovery mechanism (not shown). The lens 12 collected by the collection mechanism is subjected to predetermined post-processing and finished as a product.

  The control unit 33 controls the drive of the lifting mechanism 28 to raise the lifting plate 27 so as to have the height shown in FIG. Thereafter, the control unit 33 controls the driving of the mechanisms 26, 28, 30, and 32 to rotate the injection molded product 13 → place the lens 12 (lower the elevating plate 27) → cut the gate unit 17 → lens. A series of processes of collecting 12 and raising the lifting plate 27 is repeated. By repeating this series of processing, each lens 12 is sequentially separated from the runner portion 16 and finished as a product.

  As described above, since the gate portion 17 is cut while pulling the gate portion 17 in a direction (A direction) in which the lens 12 and the runner portion 16 are separated from each other using the receiving jig 29, the orientation of the gate portion 17 is ensured. The cutting direction of the cutter 31 can be made perpendicular to the cutting direction, and the cutting can be performed with high accuracy while being a simple method.

  In the above embodiment, the receiving jig 29 on which the lens 12 is placed is moved to pull the gate portion 17. However, the holding table 25 that holds the injection molded product 13 at the lower end of the spool bush portion 14 is provided. It is good also as a structure which moves and pulls the gate part 17. FIG. In this case, the gate cut device 11 is provided with a moving mechanism for moving the holding base 25 or the lifting plate 27 in the A direction and the B direction, and the controller 33 controls the driving of the moving mechanism.

11 Gate cut device 12 Lens (Product part)
DESCRIPTION OF SYMBOLS 13 Injection molding 16 Runner part 17 Gate part 18, 19 Lens surface 21 Flange part 22 Outer peripheral surface 23 Notch surface 29 Receiving jig 31 Cutter 36 Receiving part 37 Mounting surface 38 Hooking surface 39 First guide surface 40 Second Guide surface 41 Recess

Claims (10)

In the gate cut method of cutting the gate part of the injection molded product in which the product part is molded to the runner part via the gate part,
Place the product part on the mounting surface of the jig,
A hook formed on the receiving jig and extending along the outer peripheral surface of the product part, and located on both sides of the gate part when the product part is placed on the placement surface. Hook the outer peripheral surface of the product part on the surface,
In a state where the outer peripheral surface of the product part is hooked on the hooking surface, the gate part is cut by a cutter while pulling the gate part in a direction away from the product part and the runner part. Gate cut method. A mounting surface on which the lens of the injection molded product in which the lens is molded to the runner portion via the gate portion is mounted;
A hooking surface for hooking the outer peripheral surface of the lens placed on the mounting surface when pulling the gate portion in a direction to move the lens and the runner portion away from each other;
The hooking surface is a curved surface along the outer peripheral surface of the lens, and is positioned on each of both sides of the gate portion when the lens is placed on the placement surface. Receiving jig. 3. The lens support according to claim 2 , further comprising a first guide surface that is continuous with a side opposite to a side of the hooking surface sandwiching the gate portion and guides the lens to the hooking surface. Ingredients. The lens receiving jig according to claim 3, wherein the hooking surface and the first guide surface are smoothly continuous with each other . The first guide surface is a plane;
The lens receiving jig according to claim 4 , wherein the mounting surface is a fan shape surrounded by the hooking surface and the first guide surface . The lens receiving jig according to claim 5, wherein an angle at which the mounting surface spreads is 40 ° ± 20 ° . The lens receiving jig according to claim 6, wherein a diameter of the lens is 2 mm or more and 8 mm or less . The lens support according to any one of claims 4 to 7, wherein each of the hooking surface and the first guide surface has a height substantially equal to a thickness of an outer peripheral portion of the lens. Ingredients. The lens receiving jig according to any one of claims 4 to 8 , further comprising a second guide surface that is continuous above the first guide surface and guides the lens to the mounting surface. . The lens receiving jig according to any one of claims 2 to 9 , wherein a concave portion for preventing buffering with the lens surface of the lens is formed on the mounting surface .

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