JPH07118997B2 - Mold for information recording disk - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for an information recording disk such as an optical disc.

[0002]

2. Description of the Related Art In a molding die of this type, the outer peripheral surface of a stamper disposed on the cavity surface of the mold is pressed by an outer peripheral holder fitted inside the cavity recess.

This outer peripheral holder is of a donut shape whose inner peripheral edge forms the outer peripheral edge of the cavity, and it is desirable that the outer peripheral holder is assembled with extremely high precision concentricity in order to maintain the circularity of the molded disc. It is rare.

For this reason, the outer peripheral holder is fitted in the recess with a fine clearance set between the outer peripheral holder and the inner peripheral edge of the recess, and is bolted at a plurality of positions to be fixed to the mold. .

[0005]

The problem with such a molding die is that there is a very small difference between the inner diameter of the recess on the die side and the outer diameter of the outer peripheral holder, so there is a clearance for fitting there. However, even if it is set, it takes a lot of time to attach and detach the outer peripheral holder when the stamper is replaced, and it is difficult to position the outer holder after fitting.

[0006] Particularly, when heating due to temperature control, it becomes more difficult to attach / detach. Therefore, conventionally, the outer peripheral holder was assembled by setting a dimension that compromises the assembly accuracy and the operability during replacement.

The present invention has been conceived in order to solve the above-mentioned conventional problems, and its purpose is to provide a stamper having a new structure in which attachment / detachment and positioning of the outer peripheral holder can be easily performed by an extremely simple means. It is to provide a peripheral presser foot.

[0008]

SUMMARY OF THE INVENTION According to the present invention according to the above object, an outer peripheral surface of a stamper disposed on a cavity surface is pressed while being fitted into an outer side of a cavity for recess provided in a mold, and the inner surface of the stamper is pressed. The peripheral edge is provided with a donut-shaped outer peripheral holder that forms the outer peripheral edge of the cavity, and a plurality of notched step portions of a required length are provided at regular intervals at the same position on the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess, A fine fitting clearance provided between the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess by the notch step portion is formed into an operating clearance having a width larger than the fitting clearance. Especially.

Another feature is that the corners of the notched step portion are chamfered.

[0010]

[Operation] In the above-mentioned configuration, the concave and convex edges are formed by the notched step portions provided at the same position, and when the notched step portions are alternately positioned, the fine fitting clearance becomes the operation clearance having a wider width than that. However, when the operating clearances are laterally displaced by the rotation of the outer peripheral holder so as to be aligned, the convex portions between the notch step portions are located opposite to each other, and the outer peripheral holder is placed under the fine fitting clearance in the recess. It will fit.

Therefore, the outer peripheral holder is fitted and taken out with the convex portion of the outer peripheral holder positioned in the notch step portion of the inner peripheral edge of the recess, and the positioning for mounting is performed by rotating the outer peripheral holder. This can be performed by arranging the convex portions so as to face each other, and since the fitting of both the convex portions is performed under a fine fitting clearance, the accuracy can be sufficiently maintained. Further, the chamfering of the corners of the notch step allows the outer holder to rotate smoothly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 1 in the drawing denotes a mirror block having a circular plane shape, which is mounted on a holding board 3 on a back plate 2. A cavity 4 is formed on the front side of the mirror block 1 by the holding board 3 (see FIG. 3).

A sprue bush 5 and an inner peripheral holder 7 of a stamper 6 which is in contact with the cavity surface are concentrically fitted in the center of the mirror block 1.

Inside the outside of the recess 4, the stamper 6 is provided.
The outer peripheral surface of the cavity is pressed and the outer peripheral edge of the doughnut-shaped outer peripheral edge of the cavity 8 forms a fine fitting clearance (0.005 mm or less) with the inner peripheral edge of the recess. Yes, it is fixed to the mirror block 3 by bolts 10 provided at a plurality of locations.

The outer peripheral edge of the outer peripheral holder 9 and the recess 4
At the same position on the inner peripheral edge of the plurality of cutout steps 1
1 and 12 are provided at regular intervals, so that FIG.
Also, as shown in FIG. 4, the outer peripheral edge of the outer peripheral holder 9 and the inner peripheral edge of the recess 4 are respectively formed into concave and convex edges, and the notch steps 11 and 12 are different from the outer peripheral edge of the outer peripheral holder 9 depending on their mutual positions. The fitting clearances provided between the inner peripheral edge of the recess and the fitting clearances are a plurality of operation clearances 13 having a width larger than the fitting clearances.

In the illustrated example, the notch step portions 11 and 12 are provided at eight locations in the circumferential direction at equal intervals with a horizontal width of 25 °, and the notch step serving as the operation clearance 13 is 0 on one side. It is formed to a depth of about 1 to 0.05 mm.

With such a setting, the convex portion 4 between the notch steps is formed.
Since the widths of a and 9a are smaller than that of the notched step portions 11 and 12, when the mutual positions are laterally displaced, as shown in FIG.
The notch step portions 11 and 12 are alternately located within the width of the notch step portion, and a series of operating clearances 13 due to the notch step are formed therein.

Since this operating clearance 13 is significantly larger than the above-mentioned fitting clearance preset between the inner peripheral edge of the recess and the outer peripheral edge of the holder, the large operating clearance 13 is utilized to allow the outer peripheral holder 9 to move. It can be attached and detached.

In order to perform this positioning efficiently and with high accuracy, the positioning mark 14 is previously formed at the center of the protrusions 4a and 9a on the recess side and the outer peripheral holder side and on the center of the notch step 12 on the adjacent recess side. , 15 and 16 are applied, and this positioning mark is preferably used as a reference.

When the outer peripheral holder 9 is fitted, the convex portion 9a of the outer peripheral holder 9 is positioned in the notch 12 on the concave side and fitted into the recess, and then the outer peripheral holder 9 is rotated to position the positioning mark. Projection 9a up to the point where 14 and 15 coincide
Can be shifted to the side, so that the bolt holes 17 and 18 formed in the holding board 3 and the outer peripheral holder 9 are aligned with each other.
The position may be fixed by the bolt 10.

Further, due to the operation clearance 13, the position of the outer peripheral holder 9 is displaced when it is fitted, and the convex portions 4a, 9a are formed.
When the outer holder 9 turns into the notched step portions 11 and 12, the corners are difficult to turn when the outer peripheral holder 9 turns, but if the corners are chamfered in advance, such a problem can be easily solved. can do.

The chamfering of the corners is not limited to both sides, and as shown in FIG. 6, it is only necessary to chamfer the corners 11a and 12a on the sides which abut against each other by rotation. It is possible to smoothly rotate the 9 to the fixed position.

For removal, after removing the bolt 10, the outer peripheral holder 9 is rotated until the positioning mark 15 coincides with the positioning mark 16 on the recess side, and the convex portion 9a is laterally displaced. Of course, since the notch step portions 11 and 12 are alternately connected to each other and a series of operation clearances 13 are formed by the notch steps, the operation clearances 13 can be used to easily take out.

[0024]

As described above, according to the present invention, a fine fit is provided between the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess at the same position on the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess. A cutout step portion is formed which makes the combined clearance as a plurality of operation clearances having a width larger than the fitting clearance, and the operation clearance generated when the cutout step portions are alternately positioned is used to remove the outer peripheral holder. Since the attachment / detachment can be performed, the attachment / detachment work can be performed more easily than when the attachment / detachment is performed under a fine fitting clearance.

Moreover, since the positioning accuracy can be set by excluding the operability, it is not necessary to set a compromise dimension between the assembling accuracy and the operability at the time of replacement, so that the outer peripheral holder is assembled. Was there. The positioning accuracy is improved as compared with the conventional one.

Further, since it is only necessary to provide the notched step portions on the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess, the structure is not particularly complicated, and no special operation is required for attachment / detachment and positioning. Also, it has the feature that the attachment and detachment of the outer peripheral holder can be completed in a shorter time than before.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of a molding die for an information recording disk provided with a stamper outer peripheral presser according to the present invention.

FIG. 2 is a plan view of the above.

FIG. 3 is a plan view of a molding die for an information recording disc excluding an outer peripheral holder.

FIG. 4 is a plan view of an outer circumference holder.

FIG. 5 is a partial plan view showing a mounted state of an outer peripheral holder.

FIG. 6 is a partial plan view showing a mounted state when a corner is chamfered.

[Explanation of symbols]

 1 Mirror Block 2 Back Plate 3 Holding Plate 4 Cavity Forming Recess 5 Sprue Bushing 6 Stamper 7 Stamper Inner Holder 8 Cavity 9 Outer Holder 10 Bolt 11 Outer Holder Side Notch Step 12 Notch Step Notch Part 13 Operation clearance 14, 15, 16 Positioning mark

Claims (2)

[Claims] 1. A donut shape in which the outer peripheral surface of a stamper disposed on the cavity surface is fitted into the outer side of a cavity recess provided in a mold and the inner peripheral edge forms the outer peripheral edge of the cavity. An outer peripheral holder is provided, and a plurality of notched step portions having a required length are provided at regular intervals at the same position on the outer peripheral edge of the outer peripheral holder and the inner peripheral edge of the recess, and the notched step portions form a concave portion with the outer peripheral edge of the outer peripheral holder. A molding die for an information recording disk, characterized in that a fine fitting clearance provided between the inner peripheral edge and the inner peripheral edge is formed in an operation clearance having a width larger than the fitting clearance. 2. The molding die for an information recording disk according to claim 1, wherein the corner of the notch step portion is chamfered.