JP2011011452A - Mold for molding and method for adjusting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the rotational position of a core block with respect to a cavity block.SOLUTION: The cavity block 28 is formed into a columnar shape having a through-hole part 31 in the center thereof and has a molding plane 54 on the top end face thereof. The core block 29 which is formed into a stepped columnar shape having the molding plane 54 at the tip thereof, is inserted into the through-hole part 31. Key grooves 72, 73 are formed along the radial direction on the back end face 71 of the cavity block 28 on both sides sandwiching the through-hole part 31. Key grooves 68, 69 are formed on the back end face 67 of the fixed-side core block 29. Anyone of a plurality of adjustment keys 74, 76, 81 is inserted into key grooves 68, 69, 72, 73. Each of adjustment keys 74, 76, 81 has one end to be inserted into the key grooves 72, 73 and the other end to be inserted into the key grooves 68, 69 and the other end is fitted to one end at a different angle. The angle of the other end to be fitted to one end is made to correspond to an angle for rotating and adjusting the fixed-side core block 29.

Description

  The present invention relates to a molding die having means for positioning a core block that determines the shape of a part of a molded product with respect to a cavity block that determines the shape of another part, and an adjustment method thereof.

  Conventionally, a diffraction grating optical element used in a pickup unit of a compact disc player is composed of a diffraction grating main body and a holding frame for holding the diffraction grating main body, and is made of a material such as a transparent resin. Made by injection molding. The diffraction grating main body has a diffraction grating surface in which straight grooves are formed at a constant pitch on a flat plate-shaped surface, and a mirror surface on the back surface. The straight grooves are aligned in one direction (lattice direction) with respect to the holding frame. The holding frame is formed with a positioning portion such as a hole or a notch for use in positioning when the diffraction grating optical element is incorporated in an apparatus or the like.

  When making such a diffraction grating optical element by injection molding, in order to mold the grating direction in a fixed direction with respect to the holding frame, the core block that molds the diffraction grating surface is compared with the cavity block that molds the holding frame. Must be accurately positioned in the direction of rotation.

  Therefore, conventionally, as shown in FIG. 23, the rotational position of the core block 2 is positioned with respect to the cavity block 1 by a pair of parallel keys 3. The core block 2 has a front end surface having a molding surface 2a for forming the diffraction grating surface, and a pair of key grooves 2c provided in the radial direction of the rear end surface 2b opposite to the front end surface. The cavity block 1 includes a through-hole portion 1c provided at the center of the rear end surface 1b opposite to the front end surface having the molding surface 1a for molding the holding frame, and key grooves 1d, 1e provided in the radial direction of the rear end surface 1b. I have. The through-hole part 1c has a level | step difference in the inner periphery formed in circular cross section. The core block 2 has a step on the outer periphery formed in a circular cross section, and is inserted into the through hole 1c. The core block 2 is positioned in the rotational direction by inserting the parallel key 3 into the key grooves 2c, 2d, 1d, and 1e, respectively.

  By the way, there is a possibility that the lattice direction with respect to the holding frame is out of alignment due to an error in the dimensional accuracy of the mold or an assembly error. Therefore, it is desired to be able to adjust the rotational position of the core block with respect to the cavity block.

  As a conventional technique for adjusting the rotational position of a mold, it has a core having a mold piece for generating a diffraction grating surface at the tip and a fixed mold for forming a holding frame, and the core is formed in a cylindrical shape. The core is fixed at a predetermined rotational position with respect to the fixed mold by being rotatably attached to the fixed mold and abutting the tip of the screw pin screwed into the fixed mold with the core of the core. A molding die is known that positions the lattice direction at a fixed angle with respect to the holding frame (Patent Document 1).

  In addition, a plurality of positioning holes are provided in a mold insert portion having a molding surface at the tip, and a positioning pin is inserted by selecting one of the holes and the base plate into which the mold insert portion is inserted Resin lens that provides a groove for engaging the positioning pin, determines the rotational position of the mold insert relative to the base plate by engaging the positioning pin and the groove, and adjusts the rotational position by changing the hole for inserting the positioning pin A molding die is known (Patent Document 2).

JP 2002-90518 A (paragraph [0076], FIG. 19) JP 2007-301744 A (paragraph [0023] FIGS. 1 and 2)

  However, in the invention described in Patent Literature 1, since the core is rotated with respect to the fixed mold and then fixed with the screw pin, there is a possibility that the core may shift when the core is fixed with the screw pin. Moreover, in the invention described in Patent Document 2, it is necessary to provide a plurality of holes for positioning in the mold insert portion, which increases the processing cost. In addition, since the plurality of holes are formed at positions evenly allocated in the circumferential direction centering on the mold insert portion, there is a drawback that the rotational position cannot be finely adjusted.

  The present invention has been made in order to solve the above-described problems. A central portion molded at a fixed rotational position with respect to the peripheral portion is formed with respect to the cavity block for forming the peripheral portion of the molded product. Provided is a molding die capable of adjusting the rotational position of a core block to be molded, and an adjustment method thereof.

  In order to achieve the above object, in the molding die of the present invention, the molding surface for molding the peripheral portion of the molded product is formed in a circular cross section at the center of the rear end surface opposite to the front end surface and the front end surface. It has a cavity block with a through-hole part with a step on the inner periphery and a molding surface for forming the central part of the molded product at the tip surface, and is formed in a shape with a step on the outer periphery formed in a circular cross section. A core block inserted into the through-hole portion, a key groove provided in a radial direction on a rear end surface of the cavity block, a key groove provided in a radial direction on a rear end surface of the core block, and the cavity An adjustment key having one end inserted into the key groove of the block and the other end inserted into the key groove of the core block, and using an adjustment key with a different mounting angle of the other end with respect to the one end, Core block It is obtained so as to adjust the rotational position relative to the cavity block.

  The molding die may be a multi-cavity die. In this case, it is preferable that the cavity block and the core block are respectively provided at the same circumferentially-divided position. Further, the cavity block may be configured to be fixed to the mold plate of the molding die, or may be configured to be rotatably inserted into a hole portion of the mold plate and positioned for rotation with a parallel pin or the like. Further, the structure may be such that the rotational position of the cavity block can be adjusted with respect to the template. Further, as the axial positioning means of the core block, a step may be provided on the outer periphery, and this step may be used for axial positioning by contacting the step provided on the inner wall of the through hole portion, or the rear end surface May be fixed to the mounting plate by fastening means such as bolts or screws and positioned in the axial direction with reference to the mounting plate.

  The adjustment key is provided in a posture in which the other end is rotated in the circumferential direction around a virtual center point set on the axis of one end and on the opposite side of the other end with respect to the other end. A plurality of adjustment keys may be used. In this case, it is preferable to provide a key groove on the rear end face of the core block and the cavity block so that they can be respectively inserted into equally divided positions in the circumferential direction.

  Insert a core block having a molding surface at the tip of the center of the molded product into a through-hole formed in a cavity block having a molding surface at the tip of the periphery of the molded product. The reference key groove formed and the key groove formed on the rear end surface of the core block have one end inserted into the key groove of the cavity block and the other end inserted into the key groove of the core block. An adjustment key is inserted into the core block to position the rotational position of the core block relative to the cavity block. A plurality of adjustment keys are prepared by changing the mounting angle of the other end with respect to one end. The attachment angle at the other end corresponds to the angle for adjusting the rotation of the core block. The rotational position of the core block with respect to the cavity block is adjusted by selectively using an adjustment key whose mounting angle at the other end coincides with an angle for rotationally adjusting the core block.

  In the molding die of the present invention, an adjustment key having one end inserted into the key groove of the cavity block and the other end inserted into the key groove of the core block and having the other mounting angle changed with respect to the one end is provided. Since it is selected and used from a plurality, it is possible to accurately adjust the rotation of the cavity block with respect to the core block.

It is a perspective view which shows the diffraction grating optical element shape | molded with the metal mold | die of this invention. It is sectional drawing which shows the metal mold | die for the state of the mold closed. It is sectional drawing which shows the metal mold | die for the state of the state which opened the type | mold. It is a perspective view which shows the molded product taken out from the metal mold | die for shaping | molding. It is a disassembled perspective view which shows a stationary-side template, a stationary-side cavity block, and a stationary-side core block. It is sectional drawing which cut | disconnected the fixed side template, the fixed side cavity block, and the fixed side core block along the gate direction (AA line shown in FIG. 9). It is sectional drawing which cut | disconnected the fixed side template, the fixed side cavity block, and the fixed side core block along the orthogonal direction (BB line shown in FIG. 9) with respect to the gate direction. It is a disassembled perspective view which shows the hole provided in the stationary side template, the stationary side cavity block, the stationary side core block, a pair of key member, and a parallel pin. It is a top view which shows the state which integrated the hole provided in the stationary side template, the stationary side cavity block, the stationary side core block, a pair of key member, and a parallel pin. It is a top view which shows the adjustment key which carries out rotation adjustment of the fixed side core block counterclockwise with respect to a fixed side cavity block. It is a top view which shows the fixed side cavity block which performed rotation adjustment of the fixed side core block using the adjustment key demonstrated in FIG. It is a top view which shows the adjustment key which carries out rotation adjustment of the fixed side core block clockwise with respect to a fixed side cavity block. It is a top view which shows the stationary-side cavity block which performed rotation adjustment of the stationary-side core block using the adjustment key demonstrated in FIG. It is a disassembled perspective view which shows another embodiment which adjusted the rotation position with respect to the hole of a stationary-side cavity block using a pair of contact member in addition to a parallel pin. It is a top view which shows the stationary-side cavity block of embodiment described in FIG. It is sectional drawing cut | disconnected along the EE line described in FIG. It is explanatory drawing which shows the pair of contact member which adjusts so that a stationary-side cavity block may shift | deviate clockwise with respect to a hole part. It is a top view which shows the state which adjusted the rotation position of the stationary side cavity block using a pair of contact member demonstrated in FIG. It is explanatory drawing which shows the pair of contact member adjusted so that a stationary-side cavity block may shift | deviate counterclockwise with respect to a hole. It is a top view which shows the state which adjusted the rotation position of the stationary-side cavity block using a pair of contact member demonstrated in FIG. It is a disassembled perspective view which shows other embodiment using the adjustment member which provided the pair of contact member integrally. It is a top view which shows the state which adjusted the rotation position of the stationary side cavity block using the adjustment member demonstrated in FIG. It is a disassembled perspective view which shows the principal part of the metal mold | die of the prior art which inserts a parallel key and positions the rotation position of the core block with respect to a cavity block.

  As shown in FIG. 1, the diffraction grating optical element 10 is made of a transparent resin material by injection molding. The diffraction grating optical element 10 is provided with a recess 12 that is lowered by one step on the surface of a disk-shaped substrate, and a diffraction grating 13 is formed on the bottom surface of the recess 12. The edge portion 14 surrounding the recess 12 is formed with semicircular cutout portions 15 and 16 on both sides in the radial direction. The pair of notches 15 and 16 are used for positioning when incorporated in an optical pickup device, for example. The diffraction grating 13 is formed in a direction in which the grating direction is constant with respect to an axis passing through the centers of the pair of notches 15 and 16, for example, in an orthogonal direction. Reference numeral 17 denotes a gate mark, and the pair of cutout portions 15 and 16 are on an axis having a fixed angle with respect to the gate direction communicating with the cavity of the molding die for molding the optical element, for example, on an axis that is orthogonal Is formed.

  As shown in FIGS. 2 and 3, the molding die 20 for molding the diffraction grating optical element 10 includes a fixed side die 21 and a movable side die 22. The stationary mold 21 is attached to a stationary platen (not shown) of a mold clamping device (not shown) of the injection molding apparatus. The movable mold 22 is attached to a movable platen (not shown) of a mold clamping device (not shown) of an injection molding apparatus via an extrusion pin drive mechanism (not shown). The fixed-side mold 21 and the movable-side mold 22 are guided by a guide pin (not shown) during the mold clamping operation to move, so that the movable-side mold 22 moves to the closed position, and the fixed-side mold 21 and Combine with each other.

  The fixed-side mold 21 includes a fixed-side mounting plate 23, a fixed-side receiving plate 26, a fixed-side mold plate 27, a plurality of fixed-side cavity blocks 28, and a plurality of fixed-side core blocks 29. The fixed side receiving plate 26 is fixed to the fixed side mounting plate 23, and the fixed side mold plate 27 is fixed to the fixed side receiving plate 26. The fixed-side mold plate 27 is provided with a plurality of through-hole portions 30 penetrating in the opening / closing direction of the mold, and the fixed-side cavity block 28 is fitted in each through-hole portion 30. The fixed-side core block 29 is fitted into a through-hole portion 31 provided at the center of each fixed-side cavity block 28. The fixed-side cavity block 28 and the fixed-side core block 29 define the upper half of the cavity 32 that is a space for producing the product portion (diffraction grating optical element) 10.

  Each fixed-side cavity block 28 and each fixed-side core block 29 each have a shape having a step on the outer periphery formed in a circular cross section. The through-hole portion 30 and the through-hole portion 31 have a shape having a step on the inner periphery formed in a circular cross section. Each fixed-side core block 29 is fixed to the fixed-side receiving plate 26 by connecting bolts 33. The fixed side core block 29 and the fixed side cavity block 28 have a fixed side receiving plate 26 attached to the back (rear end surface), and the fixing side receiving plate 26 has a mounting surface 34 to prevent the fixed side receiving plate 26 from coming off from the fixed side mold plate 27. Has been made. The fixed side mounting plate 23 is mounted on a fixed side platen (not shown) of the mold clamping device.

  The movable mold 22 also has the same configuration as the fixed mold 21 described above. That is, it is composed of a movable side receiving plate 35, a movable side mold plate 36, a plurality of movable side cavity blocks 37, and a plurality of movable side core blocks 38. The movable side mold plate 36 is fixed to the movable side receiving plate 35. Each movable-side cavity block 37 is fitted into each movable-side through-hole 39 provided at a position facing each through-hole 30 in the movable-side template 36, and each movable-side core block 38 is The movable side cavity block 37 is fitted into a movable side through hole 40 provided at the center.

  The movable side cavity block 37 and the movable side core block 38 define the lower half of the cavity 32. Each movable-side cavity block 37 and each movable-side core block 38 have the same stepped columnar shape as the fixed side, and each movable-side core block 38 is fixed to the movable-side receiving plate 35 by a connecting bolt 41. ing. A reference surface 42 of the movable side receiving plate 35 is attached behind each movable side core block 38 and each movable side cavity block 37 (rear end surface). A push pin drive mechanism (not shown) is built behind the movable side receiving plate 35, and a movable side mounting plate (not shown) is attached to the back thereof. This movable side mounting plate is attached to a movable side platen (not shown) of the mold clamping device.

  The runner 43 and the gate 44 are formed between the template plates 27 and 36 on the fixed side and the movable side, and between the cavity blocks 28 and 37 on the fixed side and the movable side. In a state where the nozzle 45 at the tip of the injection cylinder is in contact with the sprue bush 46, the molten resin is injected into the cavity 32 communicating with the sprue 47, the runner 43, and the gate 44. Thereafter, after the mold is cooled and the molded product is solidified, when the movable mold 22 is moved to the open position, the molded article leaves the fixed mold 21 while being in contact with the movable mold 22. Thereafter, the molded product is extruded from the movable mold 22 by the extrusion of the extrusion pin 48. The runner 43 is a spoke-shaped isometric runner. For example, in the case of an eight-piece die, as shown in FIG. 4, the sprue portion 49, the eight runner portions 50, the gate portion 53, and eight pieces. The molded product 51 in which the product part 10 is integrated is taken out from the molding die 20. Thereafter, the diffraction grating optical element 10 is obtained by performing a process of cutting the product portion 10 from the gate portion 53.

  As shown in FIG. 5, the fixed-side mold plate 27 is provided with through-hole portions 30 at eight divided positions on the same circumference on a reference surface 52 that contacts the mounting surface 34 of the fixed-side receiving plate 26. . A set of a fixed cavity block 28 and a fixed core block 29 is set in each through hole 30. As shown in FIGS. 6 and 7, at the tip of the fixed-side cavity block 28, the gate 44 and a part forming part of the runner 43 and the upper half of the edge part 14 including the notches 15 and 16 are provided. A molding surface 54 to be molded is formed. A molding surface 55 for molding the recess 12 including the diffraction grating 13 is formed at the tip of the fixed-side core block 29.

  Note that the movable-side mold plate 36, the movable-side cavity block 37, and the movable-side core block 38 on the movable side have the same configuration as that of the fixed side described above. The difference is that at the tip of the movable side cavity block 37, there is a portion that forms the gate 44 and the remainder of the runner 43 and a molding surface 56 that molds the lower half of the edge portion 14 including the notches 15 and 16. There is a point that is formed and a molding surface 57 that molds the back surface of the recess 12 is formed at the tip of the movable side core block 38, but basically the fixed side with respect to the parting surface PL. Since the configuration is the same as the upside down configuration, only the fixed side will be described below, and the description on the movable side will be omitted.

  As shown in FIG. 8, the fixed-side cavity block 28 has a small-diameter front end portion 60 having a molding surface 54 and a rear-end portion 61 having a larger diameter than that. The rear end 61 is formed with a D surface 62 in which a part of the outer periphery is cut. The through hole 30 provided in the fixed side mold plate 27 includes a front end hole 64 into which the front end 60 is fitted, and a rear end hole 65 into which the rear end 61 is inserted. A D surface 66 is formed on a part of the inner periphery. When the fixed side cavity block 28 is inserted into the through hole 30 with the D surfaces 62 and 66 aligned, the runner 43 of the fixed side cavity block 28 is positioned by positioning the fixed side cavity block 28 in the circumferential direction with respect to the through hole 30. , And the gate 44 coincides with the runner 43 of the fixed-side template 27.

  Since the rear end portion 61 having the D surface 62 and the rear end hole portion 65 having the D surface 66 are fitted with medium accuracy, the center of the through hole portion 30 is shown in detail in FIG. There is a slight backlash in the circumferential direction. The fixed-side cavity block 28 rotates in the circumferential direction within the range of the play.

  On the other hand, the fixed-side core block 29 is set so as to be rotatable in the circumferential direction with respect to a stepped through-hole portion 31 provided in the fixed-side cavity block 28. Therefore, it is necessary to position the fixed-side core block 29 in the circumferential direction with high accuracy with respect to the fixed-side cavity block 28. Therefore, a pair of key grooves 68 and 69 are formed on the fixed-side core block 29 on the rear end surface 67 opposite to the molding surface 55. The pair of key grooves 68 and 69 are provided on both sides of the threaded portion 70 into which the connecting bolt 33 is screwed, and are formed in a certain direction, for example, an orthogonal direction with respect to the molding surface 55.

  On the other hand, in the fixed-side cavity block 28, key grooves 72 and 73 are formed on the rear end surface 71 opposite to the molding surface 54 in the radial direction, that is, on both sides of the through-hole portion 31. The pair of key grooves 72 and 73 are formed in a certain direction, for example, an orthogonal direction with respect to the gate direction. The fixed-side core block 29 is fitted into the fixed-side cavity block 28 and the fixed-side core block 29 is rotated to a rotational position where the key grooves 72 and 73 coincide with the key grooves 68 and 69, and then a pair of adjustment keys 74 are pressed. It fits in the key grooves 72, 73, 68, 69, respectively. When fitted, both sides in the width direction of the pair of adjustment keys 74 are in surface contact with only the inner walls on both sides in the width direction of the key grooves 72, 73, 68, 69. Thereby, the rotational position of the fixed-side core block 29 is positioned with high accuracy with respect to the fixed-side cavity block 28. By this positioning, the lattice direction can be adjusted to a certain direction with respect to the edge portion 14. There are two rotational positions where the key grooves 72 and 73 coincide with the key grooves 68 and 69, but the orientation of the diffraction grating 13 formed by the molding surface 55 with respect to the key grooves 68 and 69 is orthogonal to the key grooves 68 and 69 at either position. Any position is acceptable.

  Further, it is necessary to position the rotation of the fixed-side cavity block 28 within the play with high accuracy. Therefore, a first straight groove 77 is formed along the radial direction on the rear end surface 71 of the fixed-side cavity block 28. The first linear groove 77 has a U-shaped cross section and is a reference groove for determining the rotational position of the fixed cavity block 28. For example, the groove direction is a fixed direction with respect to the molding surface 54. For example, it is formed in a direction parallel to the gate direction. The through hole 30 is also formed with a second straight groove 78 having a U-shaped cross section. The second linear groove 78 is formed such that the groove direction coincides with a fixed direction with respect to the fixed-side template 27, for example, the gate direction.

  When the fixed-side cavity block 28 is inserted into the through-hole portion 30 in a posture in which the D surfaces 62 and 66 are aligned with each other, the directions of the first and second linear grooves 77 and 78 are substantially on the axis passing through the center of the through-hole portion 30. Match. Thereafter, parallel pins 80 having a circular cross section are inserted into the first and second linear grooves 77 and 78, so that both sides in the radial direction abut only on both side inner walls in the width direction of the first and second linear grooves 77 and 78. . This contact is a line contact. Thereby, positioning within the play can be performed with high accuracy. The parallel pin 80 may be a stepped parallel pin. In this case, the first and second linear grooves 77 and 78 may have different groove widths in accordance with the diameters of the stepped parallel pins.

  By the way, there is a possibility that the grating direction of the diffraction grating 13 with respect to the edge portion 14 is out of shape due to a processing error of the mold and an error in assembly. Therefore, by changing the adjustment key 74, the rotational position of the fixed core block 29 relative to the fixed cavity block 28 can be adjusted.

  As shown in FIG. 9, the adjustment key 74 described above has one end 74a inserted into the key grooves 72 and 73 of the fixed-side cavity block and the other end 74b inserted into the key grooves 68 and 69 of the fixed-side core block 29. The one end 74a and the other end 74b have the same width as the key grooves 68, 69, 72, 73 and have the same shape as the parallel keys arranged in a straight line. When the two adjustment keys 74 are inserted into the key grooves 68, 69, 72, and 73, the rotation position of the fixed core block 29 with respect to the fixed cavity block 28 is changed so that the key grooves 68, 69, 72, and 73 pass through the through-hole portion 31. The rotation position is aligned in the radial direction, that is, a reference rotation position set in advance (rotation position with an adjustment angle of “0” degrees).

  When the fixed-side core block 29 is rotationally adjusted counterclockwise by the angle α with respect to the fixed-side cavity block 28, an adjustment key 76 as shown in FIG. 10 is used. The adjustment key 76 has one end 76 a inserted into the key grooves 72 and 73 of the fixed side cavity block and the other end 76 b inserted into the key grooves 68 and 69 of the fixed side core block 29. The one end 76 a and the other end 76 b have a prismatic shape with the same width as the key grooves 72 and 73. The other end 76b is provided on the central axis 82 of the one end 76a and at a position rotated by an angle α in the counterclockwise direction around the virtual center point 79 on the side where the other end 76b is provided with respect to the one end 76a. It has been. The virtual center point 79 corresponds to the center of the fixed-side core block 29 (the center of the through-hole portion 31). When the two adjustment keys 76 are used and inserted into the key grooves 68, 69, 72, 73, the other end 76 b fixes the fixed core block 29 to the fixed cavity block 28 on the fixed side, as shown in FIG. The core block 29 is positioned at a position rotated counterclockwise by the angle α around the center 79 of the core block 29.

  Conversely, when the fixed-side core block 29 is rotationally adjusted with respect to the fixed-side cavity block 28 by an angle β in the clockwise direction, an adjustment key 81 shown in FIG. 12 is used. The adjustment key 81 has one end 81a inserted into the key grooves 72 and 73 of the fixed side cavity block and the other end 81b inserted into the key grooves 68 and 69 of the fixed side core block 29. The other end 81 b has a prismatic shape with the same width as the width of the key grooves 72 and 73. The other end 81b rotates on the central axis 82 of the one end 81a and counterclockwise about the virtual center point 79 on the side where the other end 81b is provided with respect to the one end 81a by an angle β. When the two adjustment keys 81 are used and inserted into the key grooves 68, 69, 72, 73, the other end 81b is fixed to the fixed-side cavity block 28 on the fixed-side core block 29 as shown in FIG. The core block 29 is positioned at a position rotated clockwise about the center 79 of the core block 29 by an angle β.

  In this way, a plurality of adjustment keys 74, 76, 81 that manage the attachment angles of the other ends 76b, 81b with respect to the one ends 76a, 81a are prepared, and an adjustment member is alternatively selected according to a desired rotation angle. Thus, the rotational position of the fixed-side core block 29 relative to the fixed-side cavity block 28 can be adjusted with high accuracy.

  By the way, there is a problem in the product due to the processing error of the mold and the error in assembly, and there is a case where it is desired to adjust the rotational position of the fixed side cavity block 28 with respect to the through hole 30. In this case, as shown in FIGS. 14 to 16, a parallel pin 80 having a cylindrical shape and two contact members 84 and 85 having a prismatic shape are used. On the other hand, a recess 86 that is partially connected to the outer periphery of the outline and a pair of key groove portions 87 and 88 that extend linearly from both sides of the recess 86 are formed at the opening of the through hole 30. Yes.

  The other end 80 b of the parallel pin 80 is inserted into the recess 86 with play in the circumferential direction centering on the through hole 30. The pair of key groove portions 87 and 88 are formed with the same groove width as that of the pair of contact members 84 and 85, and are orthogonal to the groove direction of the first linear groove 77 (the axial direction of the parallel pin 80). Is formed in the direction.

  One end 80 a of the parallel pin 80 is inserted into the first linear groove 77, and both sides in the radial direction are in line contact with both walls of the first linear groove 77. One end 84 a of the contact member 84 is inserted into the key groove portion 87 and contacts the groove end inner wall 87 a, and the other end 84 b contacts the other end 80 b of the parallel pin 80. The contact member 85 has one end 85 a inserted into the key groove portion 88 to contact the groove end inner wall 88 a, and the other end 84 b opposite to the position where the contact member 84 contacts the other end 80 b of the parallel pin 80. Abut on the side position. As shown in detail in FIG. 16, the positions of the parallel pins 80 with which the contact members 84 and 85 are in contact are on both sides in the radial direction. The pair of contact members 84 and 85 may be cylindrical.

  The pair of key groove portions 87 and 88 are determined to have a constant length C up to the groove end inner walls 87a and 88a on both sides along the groove direction. The pair of abutting members 84 and 85 have both ends 84a and 85a parallel to each other, and the abutting members 84 and 85 described in FIGS. 14 to 16 have the same axial length D. It is made. For this reason, when a pair of contact members 84 and 85 having the same length D is used, the rotational position of the fixed-side cavity block 28 with respect to the through hole 30 is such that the shaft 91 of the parallel pin 80 and the grooves of the key grooves 87 and 88 are aligned. The rotation position coincides with the orthogonal axis 90 orthogonal to the axis 92 along the direction, that is, a preset reference rotation position (rotation position with an adjustment angle of “0” degree).

  As the contact members 84 and 85, a plurality of types having different lengths D as described above are prepared. Depending on the rotation angle of the fixed cavity block 28 with respect to the through hole 30, the contact members 84 and 85 having different lengths are used on both sides of the parallel pin 80, so that the parallel pin 80 in the recess 86 is formed. Since the abutting position is shifted from the reference rotation position in the clockwise direction or the counterclockwise direction, the rotation position of the fixed-side cavity block 28 with respect to the through-hole portion 30 can be adjusted.

  The contact member 93 shown in FIG. 17 has a length F longer than the length D. The abutting member 94 used as a pair has a length G shorter than the length D. When the abutting member 93 having a length F is inserted into the key groove portion 87 and the abutting member 94 having a length G is inserted into the key groove portion 88, one end 93a of the abutting member 93 is connected to the key groove portion 87 as shown in FIG. One end 94a of the contact member 94 contacts the groove end inner wall 88a. The other ends 93 b and 94 b of the contact members 93 and 94 are in contact with both sides of the other end 80 b of the parallel pin 80. Since the contact member 93 on the counterclockwise direction across the orthogonal shaft 90 is long, the parallel pin 80 rotates around the center 79 of the fixed-side core block 29 from the reference rotation position by the angle α in the clockwise direction. To do. Therefore, the fixed-side cavity block 28 can be rotated to a position that is rotated clockwise by the angle α with respect to the reference rotation position.

  Further, for example, the contact member 95 shown in FIG. 19 has a length H shorter than the length D. The contact member 96 used as a pair has a length I longer than the length D of the contact member 84. When the abutting member 95 having a short length H is inserted into the key groove portion 87 and the abutting member 96 having a long length I is inserted into the key groove portion 88, the other ends 95b of the abutting members 95 and 96 are shown in FIG. 96b abuts on both sides of the other end 80b of the parallel pin 80, and the abutting member 96 on the clockwise side across the orthogonal shaft 90 is long, so that the parallel pin 80 is centered on the center 79 of the fixed-side core block 29. Thus, it rotates by an angle β counterclockwise from the reference rotation position. Therefore, the fixed-side cavity block 28 can be rotated to a position that rotates counterclockwise by the angle β with respect to the reference rotation position.

  As described above, a plurality of contact members 84, 85, 93, 94, 95, and 96 whose lengths are managed are prepared, and a combination of contact members is selectively selected according to a desired rotation angle. Thus, the rotational position of the fixed-side cavity block 28 relative to the through hole 30 can be adjusted with high accuracy. The combinations of the lengths of the contact members 84, 85, 93, 94, 95, and 96 can be derived from the equation shown in [Equation 1], respectively.

[Equation 1]
C = D1 + D2 + (M / Cosθ) + (J × Tanθ)

  Here, θ is a rotation angle (desired adjustment angle) with respect to the reference rotation position, C is the length of the groove end inner walls 87a, 88a on both sides of the key groove portions 87, 88, D1 is the length of one abutting member 84, D2 is the length of the other contact member 85, M is the diameter of the parallel pin 80, and J is the width of the contact members 84 and 85 (the groove width of the key groove portion).

  In the above-described embodiment, the pair of key groove portions 87 and 88 are formed in a direction orthogonal to the first linear groove 77. However, the key groove portions 87 and 88 are not limited to the orthogonal direction and may be formed in the intersecting direction. The contact members 84, 85, 93, 94, 95, 96 include the other ends 84b, 85b, 93b, 94b, 95b, 96b, or both ends 84a, 84b, 85a, 85b, 93a, 93b, 95a, 95b. 96a, 96b may be rounded. The roundness may be formed on a spherical surface or a U-shaped arc surface when viewed from a plane.

  Moreover, you may make a pair of contact members 84 and 85 integrally. In this case, as shown in FIGS. 21 and 22, an adjustment member 98 having a substantially C shape is used. The adjustment member 98 is integrally provided with contact portions 100 and 101 having the same action as the contact members 95 and 96 described in FIGS. 19 and 20 at both ends of the C-shaped open side. It is inserted into a recess 99 provided on the outer periphery of the through hole 30. Both ends 98a, 98b of the adjustment member 98 abut against inner walls 99a, 99b at both ends of the recess 99, and the inner walls 99a, 99b correspond to the groove end inner wall 87a and the groove end inner wall 88a, respectively. By using the abutting portions 100 and 101 having different lengths, the abutting position with respect to the parallel pin 80 inserted between them can be shifted in the recess 99, and thus the abutting portion Even if the adjusting member 98 in which the members 84 and 85 are integrally formed is used, the rotational position of the fixed-side cavity block 28 with respect to the through hole 30 can be adjusted. In this embodiment, since it is not necessary to select each combination of the lengths of the contact members 84, 85, 93, 94, 95, and 96, the adjustment member 98 can be easily selected.

Although the present embodiment has been described above, the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto and does not depart from the gist thereof. Various modifications can be made within the range.

  For example, in the above embodiment, the mold is described as a mold for molding a diffraction grating optical element. However, the present invention is not limited to this, and for example, an optical element such as a camera or a lens for optical communication is molded. A mold may be used. The molding die of the present invention is not limited to resin molding, but may be employed, for example, as a glass molding die, and may also be employed as an aluminum die casting die. Furthermore, although it is described as an eight-piece mold, it is not limited to an eight-piece mold, and can be applied to a plurality of molds other than eight. Can be adopted. Furthermore, although the core block and the cavity block for transferring the surface on the diffraction grating 13 side are provided in the fixed mold, they may be provided in the movable mold.

  Furthermore, in each said embodiment, although the 2nd linear groove 78 provided in the through-hole part 30 is formed in the direction which corresponds to a gate direction, in this invention, it is not necessary to make it correspond to a gate direction. The second linear groove 78 may be formed in a direction shifted by a certain angle from the center 79 of the fixed-side core block 29 with respect to the gate direction).

  In the above embodiments, only the positioning of the rotational position of the fixed-side core block 29 has been described. However, the present embodiment is not limited to this, and as shown in FIGS. The rotation position of the core block 38 can also be adjusted by inserting the adjustment key 74. Note that the rotation adjustment of the core block is not limited to being performed on both the fixed side and the movable side, but only one of them may be performed.

  Further, in each of the above embodiments, two adjustment keys 74, 76, 81 are used, but three or more may be used, or only one may be used. In the embodiment described with reference to FIG. 8, the fixed-side cavity block 28 is rotatably inserted into the through hole 30 and the rotation is positioned by the parallel pin 80. In the embodiment described with reference to FIGS. The fixed-side cavity block 28 is configured to be adjustable with respect to the through hole 30. However, the present invention is not limited to these embodiments, and the fixed-side cavity block 28 is fixed to the fixed-side mold plate 27. Thus, only the fixed-side core block 29 may be configured to be rotatable.

  In each of the above embodiments, the reinforcing receiving plates 26 and 35 are provided behind the template plates 27 and 36. However, the receiving plates 26 and 35 are omitted, and the template plates 27 and 36 are directly attached to the mounting plate 23. You may attach to.

10 Diffraction grating optical element (Product part)
27 Fixed Side Template 28 Fixed Side Cavity Block 29 Fixed Side Core Block 68, 69 Key Grooves 72, 73 Key Grooves Provided on Fixed Side Cavity Block 74, 76, 81 Adjustment Key

Claims (3)

Cavity block having a front end surface on which a molding surface for molding a peripheral portion of a molded product is formed, and a through-hole portion having a step in the inner periphery formed in a circular cross section at the center of the rear end surface opposite to the front end surface When,
A core block which is formed in a shape having a step on the outer periphery formed in a circular cross section, having a molding surface for molding the central part of the molded product at the tip surface; and
A keyway provided in the radial direction on the rear end face of the cavity block;
A keyway provided in a radial direction on the rear end face of the core block;
An adjustment key having one end inserted into the key groove of the cavity block and the other end inserted into the key groove of the core block;
A molding die, wherein the rotation position of the core block with respect to the cavity block is adjusted by using an adjustment key in which the attachment angle of the other end with respect to the one end is changed.   The adjustment key has a posture in which the other end rotates in a circumferential direction around a virtual center point set on the axis of the one end and opposite to the one end with respect to the one end. The molding die according to claim 1, wherein the molding die is provided. Adjustment of a molding die for inserting a core block having a molding surface at the tip of the center of the molded product into a through-hole formed in a cavity block having a molding surface at the tip of the periphery of the molded product In the method
The reference key groove formed on the rear end face of the cavity block and the key groove formed on the rear end face of the core block, the one end inserted into the key groove of the cavity block, and the key of the core block By inserting an adjustment key into the groove and having the other end inserted therein to position the rotational position of the core block relative to the cavity block, and using an adjustment key with a different attachment angle of the other end relative to the one end A method for adjusting a molding die, wherein a rotational position of the core block with respect to the cavity block is adjusted.

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