JP3857041B2 - Optical disc molding die for injection molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc molding die for an injection molding machine.
[0002]
[Prior art]
A conventional optical disk molding die for an injection molding machine will be described with reference to FIG.
[0003]
In the figure, 10 is a fixed side receiving plate, 11 is a fixed side unit, 12 is an inlay portion, 13 is a movable side unit, 14 is a movable side mounting plate, 15 is a gate cutting punch, and 16 is a stamper. The fixed side unit 11 and the movable side unit 13 are installed independently by the number of the optical discs, and are fixed to the fixed side receiving plate 10 and the movable side mounting plate 14, respectively.
[0004]
[Problems to be solved by the invention]
In the structure of the conventional optical disk molding die for an injection molding machine shown in FIG. 2, the amount of thermal expansion between the fixed side receiving plate 13 and the movable side mounting plate 17 differs depending on the temperature difference between the upper die and the lower die during molding. Deviation occurs in the pitch between the fixed side unit 14 and the movable side unit 16, which causes damage to the mold due to galling in the inlay portion 15 during mold clamping. Further, due to the pitch deviation between the fixed side unit 14 and the movable side unit 16, there is a deviation between the pit shape for reading the recording signal provided in the upper die stamper 19 and the inner diameter of the disc by the lower die gate cut punch 18. A core is formed, which causes deterioration of the disk quality. An object of the present invention is to prevent the above-described mold breakage and the occurrence of pit-shaped eccentricity in a single disk.
[0005]
[Means for Solving the Problems]
In order to solve this problem, according to the present invention, the outer peripheral portion of the movable side unit is engaged with a clamp, the vertical movement of the movable side unit is restricted by the clamp, and the horizontal direction is between the movable side unit and the clamp. It is designed to move within the horizontal clearance range.
[0006]
According to the present invention, the movable unit can move in the horizontal direction even when the upper mold is heated and a pitch shift due to a thermal expansion difference occurs between the fixed unit and the movable unit. Due to this action, the movable side unit can follow the fixed side unit and determine its position, so that it is possible to prevent the mold from being damaged due to galling of the inlay portion. In addition, since there is no misalignment between the upper die stamper and the lower die gate cut punch, there is no eccentricity between the pit shape for reading the recorded signal on the disc single plate and the inner diameter of the gate cut punch, which improves the disc quality. Can be improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is an optical disc molding die for an injection molding machine in which the movable side unit is positioned with respect to the fixed side unit by the inlay portion when the mold is clamped, and the fixed side unit and the fixed side unit are mounted. a stamper, and a fixed-side mold plate and a sprue bushing provided on the central portion of the fixed unit, and the movable unit, a clamp for engaging wearing outer peripheral portion of the movable unit, the center of the movable unit and a gate cutting punch provided with a movable side mold plate having a, between the movable unit and the clamping, which is characterized in that a clearance to permit horizontal movement of the movable unit Even when the upper mold is heated and a pitch shift occurs due to thermal expansion difference between the fixed unit and the movable unit, the movable unit can move in the horizontal direction. Therefore, the movable side unit is adjusted to the position of the fixed side unit by the action of the spigot part during mold clamping, so that the position of the lower die is determined by following the amount of thermal expansion of the upper die at any temperature state. It can prevent damage due to galling of the mold caused by misalignment due to the difference in thermal expansion between the upper mold and the lower mold. Furthermore, the upper mold stamper and the lower mold gate cut punch Therefore, there is no eccentricity between the pit shape for reading the record of the disk single plate and the inner diameter of the gate cut punching, and the disk quality can be improved.
[0008]
The invention described in claim 2 is characterized in that a stepped portion is provided on the outer peripheral portion of the movable side unit, and a clamp is engaged with the stepped portion, and has the same action as the invention described in claim 1.
[0009]
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
(Embodiment)
FIG. 1 shows an optical disk molding die for an injection molding machine according to the present invention, showing the structure of a multi-cavity molding die. FIG. 1 shows an embodiment using a two-cavity molding die. In FIG. 1, 1 is a movable unit, 1 a is a locking step provided on the outer periphery of the movable unit 1, 2 is a clamp that engages with the locking step 1 a, and 3 is a lock of the movable unit 1. Clearance between the stop step 1a and the clamp 2, 4 is a movable side mounting plate, 5 is an inlay portion for aligning the movable side unit 1 with the fixed side unit 6 during mold clamping, 6 is a fixed side unit, 7 is a fixed side receiving plate, 8 is a gate cut punch, 9 is a stamper, 10 is a sprue bush provided at the center of the fixed side unit 6, 11 is a movable side template, and 12 is a fixed side template.
[0010]
In the present embodiment, a locking step 1 a is provided on the outer peripheral portion of the movable unit 1, the clamp 2 is engaged with the locking step 1 a, and the movable unit 1 is engaged with the clamp 2. In addition, a clearance 3 is provided between the locking step portion 1a of the movable side unit 1 and the clamp 2 so that the movable side unit 1 can be moved in the horizontal direction.
[0011]
The clearance 3 between the movable side unit 1 and the clamp 2 is 0.02 mm to 0.03 mm. With this clearance 3, the movable side unit 1 is horizontally controlled on the movable side mounting plate 4 while its vertical position is restricted. Can move. Therefore, even if the upper die is heated by the hot runner system and a temperature difference occurs between the lower die and the movable side unit 1 and the fixed side unit 6 have a pitch shift due to a difference in thermal expansion, the movable side unit 1 remains horizontal. Since it can move in the direction, the movable side unit 1 can follow the fixed side unit 6 to determine the position by the action of the spigot part 5 at the time of mold clamping. Thereby, the metal mold | die damage by the caulking of the inlay part 5 can be prevented. Further, since the positional deviation between the upper die stamper 9 and the lower die gate cutting punch 8 is eliminated, there is no eccentricity between the pit shape for reading the recording signal on the single disk and the gate cut punching inner diameter. Quality can be improved.
[0012]
In the above-described embodiment, the movable unit 1 is provided with the locking step 1a. However, the present invention is not limited to this configuration, and the movable unit 1 can move in the horizontal direction with the clamp 2 engaged. Any shape can be used.
[0013]
【The invention's effect】
According to the present invention, even if the upper die is heated by the hot runner and a temperature difference occurs between the lower die and the pitch deviation due to the thermal expansion difference occurs between the movable side unit and the fixed side unit, the movable side unit remains horizontal. Since the movable side unit can follow the fixed side unit by the action of the spigot part when clamping the mold, the mold can be prevented from being damaged due to galling of the spigot part. Also, since there is no misalignment between the upper stamper and the lower gate cut punch, there is no eccentricity between the pit shape for reading the recorded signal on the single disk and the gate cut punching inner diameter, and the disc quality It has the effect which can improve.
[Brief description of the drawings]
FIG. 1 is a view showing the structure of a two-piece molding die in an optical disc molding die for an injection molding machine according to the present invention.
FIG. 2 is a view showing the structure of a conventional optical disk molding die for an injection molding machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Movable unit 1a Locking step part 2 Clamp 3 Clearance 4 Movable side mounting plate 5 Inlay part 6 Fixed side unit 7 Fixed side receiving plate 8 Gate cut punch 9 Stamper 10 Sprue bush 11 Movable side template 12 Fixed side type Plate 13 Fixed side receiving plate 14 Fixed side unit 15 Inlay portion 16 Movable side unit 17 Movable side mounting plate 18 Gate cut punch 19 Stamper 20 Sprue bush

Claims (2)

In an optical disc molding die for an injection molding machine in which the movable unit is positioned with respect to the fixed side unit by the inlay part when clamping the mold, provided at the fixed side unit, the stamper mounted on the fixed side unit, and the central part of the fixed side unit a fixed-side mold plate and a sprue bushing has, and the movable unit, a clamp for engaging wearing outer peripheral portion of the movable unit, the movable side and a gate cut punch provided in the center of the movable unit and a template, between the movable unit and the clamping, injection molding machine for optical discs forming mold, characterized in that a clearance to permit horizontal movement of the movable unit.   2. The optical disk molding die for an injection molding machine according to claim 1, wherein a step portion is provided on an outer peripheral portion of the movable side unit, and a clamp is engaged with the step portion.

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