JP2006142563A - Mold for molding disc substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding a disc substrate capable of preventing the occurrence of vertical burr in the outer peripheral end part of the disc substrate and adjustable so as not to damage a constituent member for molding the outer peripheral end part of the disc substrate. <P>SOLUTION: In the mold composed of a fixed mold and a movable mold and molding the disc substrate by a cavity C, which is formed inclusive of the fixed mirror surface plate 16 of the mirror surface plates respectively provided to the opposed surfaces of the fixed mold and the movable mold, the stamper 40 provided to the movable mirror surface plate 24 and an outer peripheral stamper holder 33 for holding the stamper 40 to the movable mirror surface plate 24, a plurality of gap adjusting means 49 for uniforming the gap A between the first end surface 43 on the side of the cavity C of the outer peripheral stamper holder 33 and the first step part 42 of the fixed mirror surface plate 16 over the whole periphery is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mold for molding a disk substrate that can be adjusted so as not to generate vertical burrs at the outer peripheral edge of the disk substrate.

  There is Patent Document 1 as a patent document relating to an optical disk substrate molding die in which burrs at the outer peripheral edge of the non-recording surface of the molded substrate are reduced as much as possible, and the repair and replacement work of the ring in contact with the outer peripheral edge is simplified. The technique of Patent Document 1 is provided with a fixed mirror plate outer ring having end surface protrusions formed at positions where it is fitted to the fixed mirror plate and in contact with the outer peripheral edge of the non-recording surface, and covers the outer surface of the fixed mirror plate outer ring. In this configuration, an outer peripheral ring that presses the outer peripheral surface of the stamper against the movable specular plate is provided, and the hardness of the fixed specular plate outer ring is set lower than the hardness of the fixed specular plate and the hardness of the outer peripheral ring. With this configuration, the fixed mirror plate outer ring is easily fitted with the outer ring, and burrs at the outer peripheral edge of the molded substrate are reduced. However, the outer ring of the fixed mirror plate is forcibly fitted to the outer ring to maintain the core, so there is a part that slides strongly, and the hardness of the outer ring of the fixed mirror plate is lower than that of the outer ring. There is a problem that not only the face plate outer ring is warped and the frequency of replacement thereof becomes extremely high, but also the iron powder generated by the warpage is mixed into the molded substrate to make the disk substrate defective.

Further, there is a technique disclosed in Patent Document 2 that prevents galling of the outer peripheral ring with the fixed mold and extends the life of the stamper. The technique of Patent Document 2 includes a fixed-side mold, a movable-side mold disposed to face the fixed-side mold, and an outer peripheral ring for attaching a stamper on the surface of the movable-side mold. An optical disk substrate is manufactured by injection molding by injecting molten plastic into the center of the cavity formed between the mold and the stamper. The outer ring and fixed side mounted on the movable mold In order to perform centering when the mold is clamped, an automatic centering adjustment mechanism that automatically adjusts the centering is provided on the outer ring side. The technique of Patent Document 2 is based on the premise that the outer ring is partially in contact with and slides on the fixed mold, as in Patent Document 1, and there is no galling of the outer ring with the fixed mold. It cannot be solved sufficiently. Further, according to Patent Document 2, since the outer ring and the fixed mold are in contact with each other and slide, the gap between the outer ring and the fixed mold is not uniform, and the outer peripheral edge of the optical disk substrate In some cases, large vertical burrs are generated.
JP-A-4-368645 (page 1-3, Fig. 1) Japanese Unexamined Patent Publication No. 6-190876 (page 1-3, FIG. 1-2)

  The present invention has been made to solve the above-described problems, and can prevent vertical burrs from being generated at the outer peripheral edge of the disk substrate, and can also damage the components forming the outer peripheral edge of the disk substrate. It is an object of the present invention to provide a mold for forming a disk substrate that can be adjusted so as not to cause damage.

  That is, the invention of claim 1 comprises a fixed mold and a movable mold, and is provided on any one of the mirror plates provided on the opposing surfaces thereof and on the other mirror plate of the mirror plates. In a mold for forming a disk substrate by a cavity formed including a stamper and an outer periphery stamper holder that holds the stamper on the other mirror plate, a cavity side end surface of the outer periphery stamper holder and the one mirror plate The present invention relates to a disk substrate molding die characterized by comprising a plurality of gap adjusting means for making the gap with the step portion uniform over the entire circumference.

  According to a second aspect of the present invention, in the first aspect, the gap adjusting means presses the outer peripheral surface of the outer peripheral stamper holder to move the outer peripheral stamper holder toward the surface of the stamper. Related to the mold.

  According to a third aspect of the present invention, in the second aspect, the gap adjusting means includes an adjusting screw provided in a direction orthogonal to the surface of the stamper, a tapered portion provided at a tip of the adjusting screw, and an outer periphery of the outer peripheral stamper holder. The present invention relates to a disk substrate molding die comprising a pressing member that contacts a surface and moves in the direction of the surface of the stamper.

  The invention of claim 1 comprises a fixed mold and a movable mold, and any one of the mirror plates provided on the opposing surfaces thereof, and a stamper provided on the other mirror plate of the mirror plates. And a mold for forming a disk substrate by a cavity formed including a peripheral stamper holder that holds the stamper on the other mirror plate, a cavity side end surface of the peripheral stamper holder and a step portion of the one mirror plate Therefore, the disk substrate molding die does not generate vertical burrs at the outer peripheral edge of the disk substrate. In addition, it is possible to make adjustments so as not to damage the constituent members forming the outer peripheral end of the disk substrate.

  According to a second aspect of the present invention, in the first aspect, the gap adjusting means presses the outer peripheral surface of the outer peripheral stamper holder to move the outer peripheral stamper holder in the surface direction of the stamper. The gap between the cavity-side end surface of the holder and the step portion of the one specular plate can be effectively made uniform over the entire circumference.

  According to a third aspect of the present invention, in the second aspect, the gap adjusting means includes an adjusting screw provided in a direction orthogonal to the surface of the stamper, a tapered portion provided at a tip of the adjusting screw, and an outer periphery of the outer peripheral stamper holder. Since the pressing member moves in the surface direction of the stamper in contact with the surface, the gap can be adjusted easily and precisely.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part of a disk substrate molding die embodying the present invention. FIG. 2 is an enlarged partial sectional view in which a gap adjusting means is provided at an outer peripheral position of an outer peripheral stamper holder different from the cross sectional position shown in FIG. 3 is a perspective view of the disk substrate, and FIG. 4 is a longitudinal sectional view of the disk substrate.

  As shown in FIG. 1, the disk substrate molding die includes a fixed die 10 and a movable die 20. The fixed mold 10 is positioned by a locate ring 12 via a heat insulating plate 11 and attached to a fixed plate of an injection molding machine (not shown). The fixed mold 10 includes a fixed mold plate 14 in which the locating ring 12 and the sprue bush 13 are inserted into the center hole, a gate insert 17 in which a small diameter portion of the sprue bush 13 is externally fitted, and a large diameter portion of the gate insert 17 outside. A fixed back plate 15 fixed to the fixed mold plate 14, a fixed mirror plate 16 externally fitted to the fixed mold plate 14 through a small diameter portion of the gate insert 17, and a fixed mold plate 14 is fixed to the outer peripheral portion of the movable mold 20 so as to make contact with the movable outer peripheral ring 39 and is fixed to the outer peripheral portion of the fixed mold plate 14. It consists of a guide pin 23 that penetrates.

  The movable mold 20 is configured such that a movable mold plate 26 a to which the movable mold plate 26 is fixed is attached to a movable plate of an injection molding machine (not shown), and can be separated from, approached and pressed against the fixed mold 10. The movable mold 20 has a movable mirror plate 24 fixed to the movable mold plate 26 via a movable back plate 25 so as to face the fixed mirror plate 16, and a surface of the movable mirror plate 24 facing the fixed mirror plate 16. A stamper 40 provided to transfer the signal surface 4 to the disk substrate 1, an outer periphery stamper holder 33 provided at the outer peripheral end of the movable mirror plate 24 to hold the stamper 40 on the surface of the movable mirror plate 24, and an outer stamper holder A support ring 34 that engages with an engagement step portion 51 provided on the outer periphery of 33 and presses and fixes the outer periphery stamper holder 33 against the movable mirror plate 24; and a support ring 34 that is detachable from the support ring 34; When engaged, a lock pin 36 that pulls the support ring 34 toward the movable mirror plate 24, a spring 37 that pulls the lock pin 36, and the lock pin 36 is driven against the spring force of the spring 37. A piston 38 for releasing engagement with the holding ring 34, a movable outer ring 39 that comes into contact with the fixed outer ring 19 when the movable mold 20 is aligned with the fixed mold 10, and the movable mold 20 are fixed molds. The ball guide 22 guides the guide pin 23 through the sleeve 21 when the mold is matched with the mold 10, and the movable mirror plate 24, the movable back plate 25, and the movable mirror plate so as to be coaxial with the center hole of the fixed mirror plate 16. An ejector 30 that sequentially fits out, including a male cutter 31 that fits a protruding pin 32 provided on its central axis into a central hole provided through the mold plate 26, a fixing sleeve 29, an inner peripheral stamper holder 28, an inner It comprises driving means 27 for driving the circumferential stamper holder 28 so as to be inserted and removed.

  As shown in FIG. 2, the fixed mirror plate 16 is a thick disc, and has a first step portion 42 and a second step portion 18 at the outer peripheral end on the side facing the movable mirror plate 24, and is movable. On the opposite side of the surface facing the mirror plate 24, there is an annular groove for circulating a heat medium for controlling the temperature of the fixed mirror plate 16. The movable mirror plate 24 is a thick disk, and has a mounting step 50 at the outer peripheral end on the side facing the fixed mirror plate 16, and the movable mirror on the opposite side of the surface facing the fixed mirror plate 16. It has an annular groove for circulating a heat medium for controlling the temperature of the face plate 24. A stamper 40 is placed on the surface of the movable mirror plate 24 facing the fixed mirror plate 16. The outer circumferential stamper holder 33 is an annular member having a substantially letter-shaped cross section, and has an engaging step portion 51 having the same shape as the mounting step portion 50 of the movable mirror plate 24 on the surface of the movable mirror plate 24. When the engaging step portion 51 is inserted into the mounting step portion 50, the surface of the projecting portion 56 projecting to the inner peripheral side of the outer peripheral stamper holder 33 on the movable mirror plate 24 side is several tens of microns on the surface of the stamper 40. The counters face each other with a gap between the meters, and the outer periphery of the stamper 40 is held on the surface of the movable mirror plate 24. The inner peripheral portion of the stamper 40 is held by a collar provided at the end of the inner peripheral stamper holder 28.

  The inner peripheral side end surfaces of the projecting portion 56 of the outer peripheral stamper holder 33 are formed on the first end surface 43 and the second end surface 44 having shapes corresponding to the first step portion 42 and the second step portion 18 of the fixed mirror plate 16, respectively. ing. The two corresponding surfaces are configured to expand outward at an angle of several degrees with respect to the vertical line on the surface of the stamper 40 in order to facilitate fitting during mold matching. That is, when the fixed outer ring 19 and the movable outer ring 39 are brought into contact with each other and the mold matching is sufficiently performed, the first step portion 42 and the first end face 43 face each other with a gap A within 20 micrometers. The second step portion 18 and the second end face 44 are designed to face each other with a gap B within 10 micrometers. The gap B between the second step portion 18 and the second end surface 44 is formed to be narrower by about 5 micrometers than the gap A between the first step portion 42 and the first end surface 43, and the fixed mirror plate 16 is the outer stamper. Guidance is made to enter the holder 33.

  1 and 2 show a state where the fixed mirror plate 16 enters the outer peripheral stamper holder 33 and the fixed mold 10 and the movable mold 20 are matched with each other. At this time, the surface of the fixed mirror plate 16, the surface of the stamper 40, the first end surface 43 of the outer peripheral stamper holder 33, the end surface of the gate insert 17, the end surface of the inner peripheral stamper holder 28, the end surface of the fixing sleeve 29, the end surface of the ejector 30, A cavity C is formed by the end face of the oscutter 31 and the end face of the protruding pin 32. The cavity C is filled with molten resin from the sprue bush 13 to mold the disk substrate 1 and the center opening 2 is perforated by the male cutter 31 and the gate insert 17 in the mold.

  As shown in FIG. 2, an engagement step portion 51 having an outer peripheral surface 52 is formed on the outer peripheral portion of the outer peripheral stamper holder 33 on the movable mirror plate 24 side. The engagement step portion 51 engages with the support ring 34 and receives a force from the support ring 34 toward the movable mirror plate 24 in the direction orthogonal to the surface of the stamper 40. Six clearance adjustment means 49 are provided on the surface of the support ring 34 on the fixed mirror plate 16 side at equal circumferential angles. Further, the support ring 34 has a plurality of through holes 35 (see FIG. 1) in a direction perpendicular to the surface of the stamper 40 at circumferential angle positions different from the gap adjusting means 49. The shape of the through-hole 35 is such that the large-diameter hole through which the head 57 expanded at the tip of the lock pin 36 penetrates and the small-diameter hole into which the small-diameter shaft portion 58 adjacent to the head 57 is inserted are not confined. It is a ball shape that is smoothly continuous in the circumferential direction.

  A procedure for attaching the stamper 40 to the surface of the movable mirror plate 24 will be described. The inner peripheral stamper holder 28 removed from the movable mold 20 is passed through the center hole of the stamper 40 so that both are integrated, and the inner peripheral stamper holder 28 is inserted into the outer peripheral portion of the fixed sleeve 29 of the movable mold 20. The driving means 27 is driven to bury the inner peripheral stamper holder 28 and hold the inner peripheral portion of the stamper 40 on the movable mirror plate 24. Next, the piston 38 is driven by air pressure to advance the lock pin 36 against the spring force of the spring 37. The outer periphery stamper holder 33 and the support ring 34 are integrated, and the outer periphery stamper holder 33 is fitted into the movable mirror plate 24 while the head 57 is inserted through the large diameter hole of the through hole 35 of the support ring 34. The support ring 34 is rotated in the direction in which the shaft portion 58 is inserted into the small diameter hole of the through hole 35. The pneumatic pressure that has been driving the piston 38 forward is shut off, the lock pin 36 is retracted by the spring force of the spring 37, and the head 57 is brought into contact with the surface of the support ring 34 on the fixed mirror plate 16 side so that the outer peripheral stamper. The holder 33 is fixed to the movable mirror plate 24.

  As shown in FIG. 2, the gap adjusting means 49 is parallel to the surface of the stamper 40 and the through-holes 55 that radiate through the circumferentially divided six positions of the support ring 34 facing the outer peripheral surface 52 of the outer peripheral stamper holder 33. A screw hole 54 threaded in a direction orthogonal to the surface of the stamper on the surface of the support ring 34 on the fixed mirror plate 16 side and communicated with the through hole 55, and an opening end of the screw hole 54 on the fixed mirror plate 16 side are provided. The concave portion 53, the disc spring 47 loosely fitted in the concave portion 53, the adjusting screw 45 having the tapered portion 46 at the tip, loosely passing through the disc spring 47 and screwed into the screw hole 54, the tapered portion 46 and the outer peripheral surface 52 The pressing member 48 is loosely inserted into the through hole 55 so as to come into contact with the pressing hole 48. The pressing member 48 is preferably a steel ball, but may be another member such as a columnar member. The opening end on the outer peripheral surface 52 side of the through hole 55 is slightly reduced in diameter so that the pressing member 48 does not escape. Since the gap adjusting means 49 has such a configuration, the minute movement in the surface direction of the stamper 40 of the outer periphery stamper holder 33 can be performed precisely and easily. The taper portion 46 of the adjusting screw 45 can move the pressing member 48 more precisely in the surface direction of the stamper 40 as the angle is smaller. Further, the adjusting screw 45 may be configured so as to decenter a portion in contact with the pressing member 48 instead of the tapered portion 46. Furthermore, the disc spring may be another elastic member such as a coil spring, or may be provided with a rotation preventing means for an adjusting screw such as a double nut in addition to or instead of the elastic member.

  Next, an injection molding method of the disk substrate 1 according to the present invention and an adjustment method related thereto will be described. In an injection device (not shown), the raw material resin is melted and plasticized and stored as a molten resin. The molten resin is provided at the tip of the injection device, and the cavity C in a state where the fixed outer ring 19 and the movable outer ring 39 are not in contact with each other and is slightly opened through the nozzle pressed against the sprue bush 13 of the fixed mold 10. Is injected into. The molten resin injected into the cavity C is spread as the movable mold 20 is pressed against the fixed mold 10 at an appropriate time while filling the cavity C with the output of the injection device. The The spread molten resin reaches the first end surface of the outer peripheral stamper holder 33 that is the end of the cavity C. At that time, the gap A (see FIG. 2) is configured to expand outward at an angle of several degrees with respect to the vertical line on the surface of the stamper 40, and is not yet fully aligned. The gap A is larger than the design dimension. For this reason, when the outer peripheral stamper holder 33 and the fixed mirror plate 16 are eccentric from each other due to the assembly clearance or thermal expansion deformation of the both, and the gap A is not uniform over the entire circumference, a position where a large gap is generated. The vertical burrs 3 (refer to FIG. 3) are generated in such a manner that the molten resin enters and the end surface of the disk substrate 1 is extended. This vertical burr 3 causes a problem in appearance or touch when the disk substrate 1 is formed as a CD or DVD disk product.

  Conventionally, in order to eliminate this vertical burr 3, in a state where the fixed mold 10 and the movable mold 20 are respectively attached to the fixed plate and the movable plate of an injection molding machine (not shown), the fixed plate 14 or the movable plate 26 is pressed by the end face, and the relative position of the opposing surface of the fixed mirror plate 16 and the movable mirror plate 24 is changed. However, in order to implement this, the lower end surface of the fixed mold plate 14 or the movable mold plate 26 must be pressed with a jack, which requires considerable equipment and labor, and the disk substrate 1 is eccentric. The harmful effect of doing.

  On the other hand, the adjusting method by the gap adjusting means 49 of the present invention is extremely easy and precise as follows. When the vertical burr 3 is generated at the outer peripheral end of the molded disk substrate 1, the movable mold 20 is separated from the fixed mold 10 so that the front of the movable mold 20 can be easily expected. Then, the adjusting screw 45 of the gap adjusting means 49 corresponding to the position where the vertical burr 3 is generated is rotated to the right to reduce the interval A at that position. At this time, if necessary, the adjustment screw 45 of the gap adjustment means 49 at the symmetrical position of the gap adjustment means 49 rotated to the right is rotated to the left. If necessary, the gap adjusting means 49 adjacent to the gap adjusting means 49 corresponding to the position where the vertical burr 3 occurs and the gap adjusting means 49 at the symmetrical position are also adjusted as appropriate. When adjusting the gap adjusting means 49, it is preferable that the piston 38 is driven by air pressure to reduce or release the traction force of the lock pin 36 from the viewpoint of facilitating the movement of the outer peripheral stamper holder 33.

  In this way, the outer peripheral stamper holder 33 can be precisely moved minutely in the direction of the surface of the stamper 40 by the gap adjusting means 49, so that the interval A can be easily made uniform over the entire periphery. As a result, it is possible to prevent the vertical burrs 3 from being generated at the outer peripheral end of the disc substrate 1, and the fitting portion between the first step portion 42 and the first end face 43 and the second step portion 18 and the second step. It is possible to effectively prevent curling at the fitting portion with the end face 44.

  In addition, this invention includes what can be implemented in the aspect which added various change, correction, improvement, etc. based on the knowledge of those skilled in the art. In addition, it goes without saying that any of the embodiments to which the above-mentioned changes are added is included in the scope of the present invention as long as it does not depart from the gist of the present invention. For example, in the above embodiment, the stamper 40 is provided on the surface of the movable mirror plate 24, but it is also possible to provide the stamper on the surface of the fixed mirror plate, and it is obvious that the present invention can be applied to such a configuration. is there.

It is a principal part longitudinal cross-sectional view of the metal mold | die for disk substrate shaping which implements this invention. FIG. 2 is an enlarged partial cross-sectional view in which a gap adjusting means is provided at an outer peripheral position of an outer peripheral stamper holder different from the cross-sectional position shown in FIG. 1. It is a perspective view of a disk substrate. It is a longitudinal cross-sectional view of a disk substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc substrate 10 Fixed mold 16 Fixed mirror surface plate 20 Movable mold 24 Movable mirror surface plate 33 Outer periphery stamper holder 34 Support ring 40 Stamper 42 First step part 43 First end surface 45 Adjustment screw 46 Adjustment screw taper part 48 Pressing member 49 Gap adjusting means 52 outer peripheral surface A gap C cavity

Claims (3)

It consists of a fixed mold and a movable mold, and either one of the mirror plates provided on the opposing surfaces thereof, the stamper provided on the other mirror plate of the mirror plates, and the stamper on the other In a mold for molding a disk substrate by a cavity formed including an outer peripheral stamper holder to be held by a mirror plate,
A disk substrate molding die comprising a plurality of gap adjusting means for uniformizing a gap between a cavity side end face of the outer peripheral stamper holder and a step portion of the one mirror plate over the entire circumference.   2. The disk substrate molding die according to claim 1, wherein the gap adjusting means presses the outer peripheral surface of the outer peripheral stamper holder to move the outer peripheral stamper holder toward the surface of the stamper.   The gap adjusting means is in contact with an adjustment screw provided in a direction perpendicular to the surface of the stamper, a tapered portion provided at a tip of the adjustment screw, and an outer peripheral surface of the outer peripheral stamper holder, and in a surface direction of the stamper. The disk substrate molding die according to claim 2, comprising a pressing member that moves.

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