JP3414995B2 - Disk molding die - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk molding die. 2. Description of the Related Art Conventionally, in an injection molding machine for molding a disk, a resin melted in a heating cylinder is filled into a cavity space of a disk molding die.
The disk substrate is formed by cooling. Then, a stamper is provided facing the cavity space, and the irregularities of the stamper are transferred to the information surface of the disk substrate. FIG. 2 is a diagram showing a retracted state of a compression core in a conventional disk molding die, and FIG. 3 is a diagram showing an advanced state of a compression core in a conventional disk molding die.
In the figure, 31 is a fixed platen, 11 is a fixed mold attached to the fixed platen 31, 32 is a movable platen, and 12 is attached to the movable platen 32 so as to be able to advance and retreat with respect to the fixed mold 11 and to make contact therewith. It is a movable mold that is arranged detachably. The movable mold 12 is advanced (moved to the right in the figure) by a mold clamping mechanism (not shown) to close the mold, and a cavity space 15 is formed between the fixed mold 11 and the movable mold 12. You. The mold clamping is performed by applying a mold clamping force to the movable mold 12 by the mold clamping mechanism. In this state, the cavity space 15 is filled with resin, and the compression core 24 of the movable mold 12 is removed. It is advanced and compression takes place. Thereafter, the movable mold 12 is retracted (moved to the left in the figure) by the mold clamping mechanism, whereby the mold is opened and a disc (not shown) is formed. The stationary mold 11 includes a sprue bush 16 for receiving resin injected from an injection nozzle of a heating cylinder (not shown), an annular inner stamper holder 17 disposed on the outer periphery of the sprue bush 16, and an inner stamper holder. It comprises a fixed side guide ring 18 further disposed on the outer periphery of the outer ring 17, an outer ring 19 defining an outer peripheral surface of the cavity space 15, and a stamper 21 attached to the fixed side guide ring 18 by the inner stamper holder 17. The sprue bush 16 includes
The resin injected from the injection nozzle is transferred to the cavity 1
5 is formed. The movable mold 12 is disposed so as to face the fixed-side guide ring 18 and has an annular bottom 26.
And movable plate-like guide ring 2 including a cylindrical portion 27
3, and inside the movable side guide ring 23,
It is composed of a compression core 24 arranged to be able to move forward and backward with respect to the movable side guide ring 23. The compression core 24 protrudes toward the fixed guide ring 18 side, and has a compression protrusion 25, a large diameter portion 34 formed along the inner circumference of the cylindrical portion 27, and an inner circumference of the bottom 26. Is formed along with a small diameter portion 35, and at the center of the compression core 24, a hole 29 for moving a cut punch (not shown) is formed to penetrate in the axial direction. A cylinder space 33 is formed at the center of the movable platen 32 in order to advance and retreat the compression core 24 with respect to the movable side guide ring 23. The compression piston 37 is provided so as to be able to advance and retreat in opposition. When the mold is clamped, the fixed side guide ring 18 and the movable side guide ring 2
A tapered surface S1 is formed on the outer periphery of the fixed-side guide ring 18 and a tapered surface S2 is formed on the inner periphery of the cylindrical portion 27 so that the fixed member 3 and the third member 3 can be joined. Then, a tapered surface S3 is formed on the inner periphery of the outer ring 19, and a tapered surface S4 is formed on the outer periphery of the compression convex portion 25 so that the outer ring 19 and the compression core 24 can be joined together during the compression.
Are respectively formed. In the disk molding die having the above structure,
After the movable mold 12 is advanced, the mold is closed and the mold is clamped, and the cavity space 15 is filled with resin, FIG.
As shown in (2), the compression core 24 is retracted by receiving the pressure of the resin, and is stopped at the rear stop position where the front end surface S5 of the bottom portion 26 and the rear end surface S6 of the large diameter portion 34 abut. Then, at a predetermined timing, as shown in FIG.
When the compression piston 37 is advanced from the retreat limit position by drive means (not shown), the compression core 24 is advanced by the pressing force of the compression piston 37, and the resin in the cavity space 15 is compressed. The rearward stop position of the compression core 24 is set such that the rear end surface S10 of the small diameter portion 35 is ahead of the front end surface S8 of the movable platen 32 by a distance L2. The front end face S7 of the piston 37 is set to be behind the front end face S8 of the movable platen 32 by a distance L1. Next, the disc substrate is formed by cooling the resin in the cavity space 15, and the disc substrate is perforated by advancing the cut punch. Thereafter, when the movable mold 12 is retracted and the mold is opened, the disk can be obtained.
At this time, the compression piston 37 is retracted to the retreat limit position. In the disk molding die having the above-described structure, after the cavity space 15 is filled with the resin, the compression piston 37 is advanced at a predetermined timing so that the pressure of the resin in the cavity space 15 is increased. It has become. Therefore, the irregularities of the stamper 21 are well transferred to the information surface of the disk substrate. [0010] However, in the conventional disk molding die, when the compression core 24 is located at the rear stop position and the compression piston 37 is located at the retreat limit position, A gap (gap) of a distance (L1 + L2) is formed between the rear end face S10 of the small diameter portion 35 and the front end face S7 of the compression piston 37. Therefore, when the compression piston 37 is advanced to compress the resin, the timing at which the compression piston 37 starts to advance and the front end surface S
There is a slight time lag between the timing at which the compression core 24 starts moving forward when the rear end face S10 of the small-diameter portion 35 hits. As a result, not only the setting of molding conditions becomes complicated, but also it becomes impossible to obtain a high-density disk with high accuracy. The present invention solves the problem of the conventional disk molding die described above, and provides a time interval between the timing when the compression piston starts to advance and the timing when the compression core actually starts to advance. It is an object of the present invention to provide a disk molding die capable of simplifying setting of molding conditions without causing displacement, and obtaining a high-density disk with high accuracy. [0013] To this end, in the disk molding die of the present invention, a fixed guide ring to which a stamper is attached and a fixed guide ring are disposed so as to face the fixed guide ring. The movable guide ring includes a movable guide ring, and a compression core disposed on an inner peripheral side of the movable guide ring so as to be able to advance and retreat. The movable platen, to which the movable die including the compression core and the movable side guide ring is attached, is provided with a compression piston which is advanced by driving means to advance the compression core. The rear stop position of the compression core and the retreat limit position of the compression piston are as follows:
When the compression core is located at the rear stop position and the compression piston is located at the retreat limit position, the compression core and the compression piston are set to abut on a front side of the front end face of the movable platen. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a retracted state of a compressed core according to an embodiment of the present invention.
FIG. 3 is a diagram showing a forward state of a compression core according to the embodiment of the present invention. In the figure, 31 is a fixed platen, 11 is a fixed mold attached to the fixed platen 31, 32 is a movable platen, and 12 is attached to the movable platen 32 so as to be able to advance and retreat with respect to the fixed mold 11 and to make contact therewith. It is a movable mold that is arranged detachably. The movable mold 12 is advanced (moved to the right in the figure) by a mold clamping mechanism (not shown) to close the mold, and a cavity space 15 is formed between the fixed mold 11 and the movable mold 12. You. The mold clamping is performed by applying a mold clamping force to the movable mold 12 by the mold clamping mechanism. In this state, the cavity space 15 is filled with resin, and the compression core 24 of the movable mold 12 is removed. It is advanced and compression takes place.
Thereafter, the movable mold 12 is retracted (moved to the left in the figure) by the mold clamping mechanism, whereby the mold is opened and a disc (not shown) is formed. The fixed mold 11 includes a sprue bush 16 for receiving resin injected from an injection nozzle of a heating cylinder (not shown), an annular inner stamper holder 17 disposed on the outer periphery of the sprue bush 16, and an inner stamper holder. It comprises a fixed side guide ring 18 further disposed on the outer periphery of the outer ring 17, an outer ring 19 defining an outer peripheral surface of the cavity space 15, and a stamper 21 attached to the fixed side guide ring 18 by the inner stamper holder 17. The sprue bush 16 includes
The resin injected from the injection nozzle is transferred to the cavity 1
5 is formed. The movable mold 12 is disposed so as to face the fixed-side guide ring 18 and has an annular bottom 26.
And movable plate-like guide ring 2 including a cylindrical portion 27
3, and inside the movable side guide ring 23,
It is composed of a compression core 24 arranged to be able to move forward and backward with respect to the movable side guide ring 23. The compression core 24 protrudes toward the fixed guide ring 18 side, and has a compression protrusion 25, a large diameter portion 34 formed along the inner circumference of the cylindrical portion 27, and an inner circumference of the bottom 26. Is formed along with a small diameter portion 35, and at the center of the compression core 24, a hole 29 for moving a cut punch (not shown) is formed to penetrate in the axial direction. A cylinder space 33 is formed in the center of the movable platen 32 in order to advance and retreat the compression core 24 with respect to the movable side guide ring 23. The compression piston 37 is provided so as to be able to advance and retreat in opposition. When the mold is clamped, the fixed side guide ring 18 and the movable side guide ring 2
A tapered surface S1 is formed on the outer periphery of the fixed-side guide ring 18 and a tapered surface S2 is formed on the inner periphery of the cylindrical portion 27 so that the fixed member 3 and the third member 3 can be joined. Then, a tapered surface S3 is formed on the inner periphery of the outer ring 19, and a tapered surface S4 is formed on the outer periphery of the compression convex portion 25 so that the outer ring 19 and the compression core 24 can be joined together during the compression.
Are respectively formed. In the above-described disk molding die,
After the movable mold 12 is advanced, the mold is closed and the mold is closed, and the cavity space 15 is filled with resin, FIG.
As shown in (5), the compression core 24 is retracted by receiving the pressure of the resin, and is stopped at a rear stop position where the front end surface S7 of the compression piston 37 and the rear end surface S10 of the small diameter portion 35 abut. At a predetermined timing, as shown in FIG. 4, when the compression piston 37 is advanced from the retreat limit position by driving means such as a hydraulic device (not shown), the compression core 24 is advanced by the pressing force of the compression piston 37. Then, the resin in the cavity space 15 is compressed. The rearward stop position of the compression core 24 is set such that the rear end surface S10 of the small diameter portion 35 is ahead of the front end surface S8 of the movable platen 32 by a distance L2. The front end face S7 of the piston 37 is set to be ahead of the front end face S8 of the movable platen 32 by a distance L2. Next, the resin in the cavity space 15 is cooled to form a disk substrate, and the disk substrate is punched by advancing the cut punch. Thereafter, when the movable mold 12 is retracted and the mold is opened, the disk can be obtained.
At this time, the compression piston 37 is retracted to the retreat limit position. In the disk molding die having the above-described structure, after the cavity space 15 is filled with the resin, the compression piston 37 is advanced at a predetermined timing so that the pressure of the resin in the cavity space 15 is increased. It has become. Therefore, the irregularities of the stamper 21 are well transferred to the information surface of the disk substrate. By the way, when the compression core 24 is located at the rear stop position and the compression piston 37 is located at the retreat limit position, the rear end surface S1 of the small diameter portion 35
0 and the front end face S7 of the compression piston 37 are brought into contact with each other. Therefore, when the compression core 24 is advanced to compress the resin, there is a time lag between the timing at which the compression piston 37 starts to advance and the timing at which the compression core 24 actually starts to advance. Will not occur. As a result, setting of molding conditions can be simplified, and a high-density disk can be obtained with high accuracy. It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention. As described above in detail, according to the present invention, in a disk molding die, a stationary guide ring to which a stamper is attached and a stationary guide ring opposed to the stationary guide ring. A movable guide ring is provided, and a compression core is provided on the inner peripheral side of the movable guide ring so as to be able to advance and retreat. A movable platen, to which a movable mold including the compression core and the movable side guide ring is attached, is provided with a compression piston which is advanced by driving means to advance the compression core. The rear stop position of the compression core and the retreat limit position of the compression piston are as follows:
When the compression core is located at the rear stop position and the compression piston is located at the retreat limit position, the compression core and the compression piston are set to abut on a front side of the front end face of the movable platen. In this case, when the compression core is located at the rear stop position and the compression piston is located at the retreat limit position, the compression core and the compression piston are brought into contact in front of the front end surface of the movable platen. When the compression piston is advanced to compress the resin, there is no time lag between the timing when the compression piston starts to advance and the timing when the compression core actually starts to advance. As a result, setting of molding conditions can be simplified, and a high-density disk can be obtained with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a retracted state of a compression core according to an embodiment of the present invention. FIG. 2 is a view showing a retracted state of a compressed core in a conventional disk molding die. FIG. 3 is a view showing a state in which a compression core is advanced in a conventional disk molding die. FIG. 4 is a view showing a forward state of a compression core according to the embodiment of the present invention. [Description of Signs] 18 Fixed-side guide ring 21 Stamper 23 Movable-side guide ring 24 Compression core 37 Compression piston

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-198722 (JP, A) JP-A-11-48255 (JP, A) JP-A-8-300419 (JP, A) JP-A-8-300 90613 (JP, A) JP-A-7-329133 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33/30 B29C 45/26

Claims (1)

(57) Claims: (a) a fixed-side guide ring to which a stamper is attached; (b) a movable-side guide ring disposed to face the fixed-side guide ring; (c) which has a compressed core which is disposed retractably on the inner peripheral side of the movable side guide ring, consists of (d) the compressed core and the movable-side guide ring
The movable platen movable mold is attached, is advanced by the drive means, the compression piston to advance the compressed core is disposed, (e) a rearward stop position and the compression piston of the compressed core
The retraction limit position is such that the compression core is located at a rear stop position,
A disk molding die, wherein the compression core and the compression piston are set so as to be brought into contact with the front end face of the movable platen in front of the movable platen when the compression piston is located at the retreat limit position.