JP2002361688A - Mold for molding disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of a longitudinal burr at an outer peripheral edge of a disc board by suppressing occurrence of a scuff between a cavity ring and a disc plate. SOLUTION: A mold for molding the disc comprises a first support plate, a first mirror surface platen, a second support plate, a second mirror surface platen, the cavity ring 37 arranged movably to the second mirror surface platen, and an energizing means for energizing the ring 37 toward the first mirror surface platen. A hardness of an outer peripheral surface opposed to the ring 37 of the second mirror surface platen is made different from that of the inner peripheral surface opposed to the second mirror surface platen of the ring 37. Even when the ring 37 is contacted with the second mirror surface platen, occurrence of a slip and occurrence of scuff can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk molding die.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine for molding a disk substrate, a resin melted in a heating cylinder is filled in a cavity space in a disk molding die, and the resin is melted in the cavity space. Then, the resin is cooled and solidified to obtain a disk substrate.

For this purpose, the injection molding machine comprises a disk molding die comprising a fixed mold assembly and a movable mold assembly, an injection device for filling the cavity with the resin, and A mold clamping device is provided for moving the movable mold assembly toward and away from the fixed mold assembly.
Then, the movable mold assembly is moved forward and backward by the mold clamping device, and the mold of the disk molding mold is closed, the mold is opened and the mold is opened. When the mold is clamped, the disk plate of the fixed mold assembly is closed. A cavity space is formed between the movable mold assembly and the disk plate of the movable mold assembly.

[0004] The injection device includes a heating cylinder, an injection nozzle attached to a front end of the heating cylinder, and a screw rotatably and advancing and retracting in the heating cylinder.

In the measuring step, the screw is rotated, the resin is melted and stored in front of the screw, and accordingly, the screw is retracted. During this time, the disk closing mold is closed. And mold clamping is performed. Subsequently, in the injection step, the screw is advanced, and the resin stored in front of the screw is injected from the injection nozzle and is filled in the cavity space. Then, in the cooling step, the resin in the cavity space is cooled, a hole is formed, and a disk substrate is formed. Subsequently, the mold is opened, and the disk substrate is taken out.

A stamper for forming irregularities on the information surface of the disk substrate is mounted on the fixed disk plate, and a cavity ring is mounted on the movable disk plate. A periphery is formed. In the mold clamping state, a slight first clearance in the axial direction is provided between the cavity ring and the stamper so that air in the cavity space can be released as the cavity space is filled with resin. Is formed.

In the injection step, when the pressure of the resin in the cavity space, that is, the mold internal pressure increases as the resin is filled into the cavity space, the fixed-side disk plate and the movable-side disk are increased. In the parting plane between the plates, 100
Then, in the cooling step, when the resin in the cavity space is cooled and contracted in the cooling step, when the pressure in the mold is lowered, the space between the disk plates is gradually closed.

In order to prevent the resin in the cavity space from flowing out of the outer peripheral edge with the opening between the disk plates and to prevent the generation of lateral burrs, the cavity ring is fixed to the shaft ring. The movable plate is movably disposed in the direction with respect to the movable disk plate, and is urged toward the fixed disk plate. Therefore, as the space between the disk plates is opened, the cavity ring moves to the fixed disk plate side, and the first clearance is kept constant.

[0009]

However, in the conventional disk molding die, when the cavity ring moves with respect to the movable disk plate, the cavity ring is not necessarily moved in the axial direction of the disk plate. However, it does not always move in parallel, and for example, when it hits a disk plate, galling occurs.

Therefore, a predetermined second clearance is formed in the radial direction between the cavity ring and the disk plate so as to prevent the cavity ring from hitting the disk plate as the cavity ring moves. I have.

However, when a second clearance is formed between the cavity ring and the disk plate, the resin flows in the axial direction through the second clearance as the resin is filled, and as a result, the disk Vertical burrs are generated on the outer peripheral edge of the substrate.

The present invention solves the problems of the conventional disk molding die described above, suppresses the occurrence of galling between the cavity ring and the disk plate, and forms vertical burrs on the outer peripheral edge of the disk substrate. It is an object of the present invention to provide a disk molding die capable of suppressing generation of the disk.

[0013]

For this purpose, in the disk molding die of the present invention, a first support plate,
A first mirror plate attached to the first support plate, a second support plate, a second mirror plate attached to the second support plate, and an outer peripheral edge of the second mirror plate A cavity ring movably disposed with respect to a second mirror surface plate;
And a biasing means for biasing the mirror toward the mirror-finished disk.

The hardness of the outer peripheral surface of the second mirror disk facing the cavity ring is different from the hardness of the inner peripheral surface of the cavity ring facing the second mirror disk.

In another disk molding die of the present invention, the outer peripheral surface of the second mirror disk is further coated with a coating layer made of a material having high hardness.

In still another disk molding die of the present invention, a coating layer made of a material having high hardness is coated on the inner peripheral surface of the cavity ring.

In still another disk molding die according to the present invention, an outer peripheral surface of the second mirror surface disk is further coated with a coating layer made of a material having low hardness.

In still another disk molding die according to the present invention, the inner peripheral surface of the cavity ring is further coated with a coating layer made of a material having low hardness.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a main part of a disk molding die according to an embodiment of the present invention, and FIG. 2 is a sectional view of a disk molding die according to an embodiment of the present invention.

In FIG. 1, reference numeral 12 denotes a fixed-side mold assembly which is mounted on a fixed platen (not shown) by a bolt (not shown) via a mounting plate 13. The mold assembly 12 comprises a first support plate. A base plate 15, a disk plate 16 as a first mirror surface disk attached to the base plate 15 by bolts (not shown), and disposed in the base plate 15 so as to face a fixed platen side. And a sprue bushing 24 arranged adjacent to the locate ring 23. A die 28 is formed at the front end (left end in FIG. 2) of the sprue bush 24 so as to face the cavity space C. The die 28 is communicated with the die 28 and serves as a molding material injected from an injection nozzle of an injection device (not shown). A sprue 26 for passing resin is formed. The injection device includes a heating cylinder (not shown), an injection nozzle attached to a front end of the heating cylinder, and a screw rotatably and advancing and retracting in the heating cylinder.

A stamper 61 for forming irregularities on the information surface of the disk substrate is provided on the disk plate 16.
A stamper pressing bush 1 for pressing an inner peripheral edge of the stamper 61 is provided radially outward of a front half portion (a left half portion in FIG. 2) of the sprue bush 24.
4 are provided. The mold assembly 12 is also provided with an air probe (not shown) and the like.

An annular abutment ring 18 is attached to the outer peripheral edge of the disk plate 16 by bolts b1, and an annular first guide ring 19 is provided radially outward from the disk plate 16 and the abutment ring 18. It is attached to the base plate 15.

On the other hand, reference numeral 32 denotes a movable mold assembly which is attached to a movable platen (not shown) by bolts (not shown). The mold assembly 32 is attached to the base plate 35 and the base plate 35 by bolts b2. Intermediate plate 4 as second support plate
0, a disk plate 36 as a second mirror surface plate attached to the intermediate plate 40 by bolts b3, a cylinder disposed in the base plate 35 so as to face a movable platen, and attached to the intermediate plate 40 by bolts b4. And a cut punch 48 which is advanced and retracted (moves in the left-right direction in FIG. 2) along the cylinder 44 and has a front end (right end in FIG. 2) having a shape corresponding to the die 28.

The outer peripheral edge of the disk plate 36 is movable with respect to the disk plate 36 and
The annular cavity ring 3 is opposed to the abutment ring 18.
A ring-shaped second guide ring 38 is attached to the intermediate plate 40 so as to face the first guide ring 19 radially outward from the disk plate 36 and the cavity ring 37. The cavity ring 37 is attached to a rod 41 by a bolt b5, and is disposed movably with respect to the intermediate plate 40 via the rod 41. Reference numeral 39 denotes a cavity ring retainer attached to the second guide ring 38 by a bolt (not shown).
Numeral 9 is engaged with the outer peripheral edge of the cavity ring 37. The cavity ring 37 is provided on the disk plate 3.
6 is projected from the front end face (the right end face in FIG. 2),
The inner peripheral surface of the cavity ring 37 forms the outer peripheral edge of the disk substrate.

In the cylinder 44, a flange 51 formed integrally with the cut punch 48 is disposed so as to be able to advance and retreat, and a rear end (left end in FIG. 2) 5 of the flange 51 is provided.
1a is received by the cylinder 44. A cut-punch return spring 52 is provided in front of the flange 51 (to the right in FIG. 2), and the flange 51 is urged rearward by the cut-punch return spring 52.

A disk forming die is constituted by the die assemblies 12 and 32. A mold clamping device (not shown) is provided to move the die assembly 32 toward and away from the die assembly 12. Is done. By driving the mold clamping cylinder of the mold clamping device and moving the mold assembly 32 forward and backward, the mold closing, mold closing and mold opening of the disk forming mold can be performed. The cavity space C is formed between 16 and 36.

When the mold is clamped, the driving cylinder (not shown) is driven to advance the flange 51 (FIG. 2).
Is moved to the right) of the cut punch 48.
Is advanced and enters the die 28. As a result, the resin in the cavity space C can be perforated. An ejector bush 62 for projecting the disk substrate is provided radially outward in a front half portion (right half portion in FIG. 2) of the cut punch 48, and is disposed radially outward from the ejector bush 62. An air probe 47 is provided for blowing compressed air to the disk substrate to release the disk substrate from the disk plate 36. An ejector pin (not shown) and the like are also provided on the mold assembly 32.

First and second temperature control channels 93 and 94 are formed in the disk plates 16 and 36, respectively.
By supplying a temperature control medium such as water, oil, or air to the second temperature control channels 93, 94, the disk plate 16,
36 is cooled.

Further, between the cavity ring 37 and the stamper 61, a slight first axial direction is set so that the air in the cavity space C can be released with the filling of the resin into the cavity space C. 1 clearance δ1 is formed.

In the measuring step, the screw is rotated, the resin is melted and stored in front of the screw, and accordingly, the screw is retracted. During this time, the mold of the disk forming mold is closed. And mold clamping is performed. Subsequently, in the injection step, the screw is advanced, and the resin stored in front of the screw is injected from the injection nozzle and is filled in the cavity C. Then, in the cooling step, the resin in the cavity space C is cooled, drilling is performed, and the disk substrate is formed. Subsequently, the mold is opened, and the disk substrate is taken out.

Next, the operation of the disk molding die having the above configuration will be described.

In the injection step, when the mold cavity pressure in the cavity space C increases with the filling of the cavity space C with the resin, the disk plates 16, 36 are located on the parting surface between the disk plates 16, 36. Between 10
When the resin in the cavity space C is cooled and contracted in the cooling step, the inner pressure of the mold is reduced.
36 gradually closes.

In order to prevent the resin in the cavity space C from flowing out of the outer peripheral edge as the space between the disk plates 16 and 36 is opened, and to prevent the occurrence of lateral burrs, A ring 37 is disposed movably with respect to the disk plate 36 in the axial direction, and is urged toward the disk plate 16. A rod 41 is attached to the cavity ring 37,
A spring 63 as an urging means is brought into contact with the rod 41. Therefore, each of the disk plates 16, 3
With the opening of the gap 6, the cavity ring 37 is moved toward the disk plate 16 by the urging force of the spring 63, and the cavity ring 37 and the abutment ring 18 are brought into contact with each other, so that the first clearance δ1 Is kept constant.

When the cavity ring 37 moves with respect to the disk plate 36, the cavity ring 37 does not always move in parallel with the axial direction of the disk plate 36.
If it hits, it will bite. As a result, if the cavity ring 37 hits the disk plate 36 and galling occurs, the cavity ring 37 cannot be moved smoothly.

Therefore, titanium nitride (TiN) and DL are applied to the outer peripheral surface of the disk plate 36 facing the cavity ring 37 (hereinafter referred to as the “disk plate outer peripheral surface”).
A coating layer 66 made of a material having high hardness such as C is coated, and the hardness of the outer peripheral surface of the disk plate is an inner peripheral surface of the cavity ring 37 facing the disk plate 36 (hereinafter, referred to as “inner peripheral surface of the cavity ring”). ) Higher than the hardness.

As described above, since the hardness of the outer peripheral surface of the disk plate and the hardness of the inner peripheral surface of the cavity ring are made different from each other, even if the cavity ring 37 hits the disk plate 36, slippage and galling are suppressed. can do. Therefore, the cavity ring 37 can be moved smoothly.

Moreover, since galling is suppressed even when the cavity ring 37 hits the disk plate 36, the second clearance δ2 formed in the radial direction between the cavity ring 37 and the disk plate 36 is reduced.
Can be reduced. Accordingly, the amount of the resin flowing out in the axial direction through the second clearance δ2 with the filling of the resin can be reduced, so that the generation of vertical burrs on the outer peripheral edge of the disk substrate can be suppressed. it can.

When the cavity ring 37 is frequently galled, the cavity ring 37 can be easily replaced. When the disk plate 36 is frequently galled, the coating layer 66 can be easily replaced again. Since it can be coated, repair is very simple.

In particular, when molding a high-density disk substrate such as a DVD-R or the like, the temperature of the disk molding die and the temperature of the resin during molding are high, and the mold clamping force generated by the mold clamping device is low. Even when the height is high, it is possible to suppress the occurrence of vertical burrs.

In this embodiment, the outer peripheral surface of the disk plate is coated with a coating layer 66 made of a material having a high hardness so that the hardness of the outer peripheral surface of the disk plate and the hardness of the inner peripheral surface of the cavity ring are made different. However, by coating the inner peripheral surface of the cavity ring with a coating layer made of a material having high hardness, the hardness of the outer peripheral surface of the disk plate can be made different from the hardness of the inner peripheral surface of the cavity ring. Further, the outer peripheral surface of the disk plate is coated with a coating layer made of a material having low hardness such as tin (tin) or lead, or the inner peripheral surface of the cavity ring is coated with a coating layer made of a material having low hardness. Thereby, the hardness of the outer peripheral surface of the disk plate and the hardness of the inner peripheral surface of the cavity ring can be made different.

Further, by coating the outer peripheral surface of the disk plate and the inner peripheral surface of the cavity ring with coating layers made of materials having different hardnesses, the hardness of the outer peripheral surface of the disk plate is made different from the hardness of the inner peripheral surface of the cavity ring. You can also.

In the above-described embodiment, the stamper 61 is provided on the disk plate 16 and the cavity ring 37 is provided on the disk plate 36. However, the cavity ring is provided on the disk plate 16, and the disk plate 3 is provided with the cavity ring 37.
6, a stamper can be provided.

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.

[0045]

As described above in detail, according to the present invention, in the disk molding die, the first support plate and the first mirror plate attached to the first support plate are provided. A second support plate, a second mirror surface plate attached to the second support plate, and an outer peripheral edge of the second mirror surface plate movably disposed with respect to the second mirror surface disk. And a biasing means for biasing the cavity ring toward the first mirror plate.

The hardness of the outer peripheral surface of the second mirror disk facing the cavity ring is different from the hardness of the inner peripheral surface of the cavity ring facing the second mirror disk.

In this case, since the hardness of the outer peripheral surface of the second mirror surface disk and the hardness of the inner peripheral surface of the cavity ring are made different, slippage occurs even when the cavity ring hits the second mirror surface disk. The occurrence of galling can be suppressed. Therefore, the cavity ring can be moved smoothly.

Further, the clearance formed in the radial direction between the cavity ring and the second mirror surface disk can be reduced.
The amount of the molding material flowing out in the axial direction via the clearance can be reduced. Therefore, generation of vertical burrs on the outer peripheral edge of the disk substrate can be suppressed.

In another disk molding die of the present invention, the outer peripheral surface of the second mirror surface disk is further coated with a coating layer made of a material having high hardness.

In this case, if the cavity ring frequently seizes, the cavity ring can be easily replaced. If the second mirror surface frequently seizes, the coating layer can be easily replaced again. Since it can be coated, repair is very simple.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of a disk molding die according to an embodiment of the present invention.

FIG. 2 is a sectional view of a disk molding die according to the embodiment of the present invention.

[Explanation of symbols]

 12, 32 Mold assembly 15 Base plate 16, 36 Disk plate 37 Cavity ring 40 Intermediate plate 63 Spring 66 Coating layer

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroyuki Sawaishi 731, Naganumahara-cho, Inage-ku, Chiba-shi, Chiba F-term (reference) in Chiba Works, Sumitomo Heavy Industries, Ltd. 4F202 AD27 AF16 AH38 AH79 CA11 CB01 CK06 CK42

Claims (5)

[Claims] (A) a first support plate; and (b) a first mirror plate attached to the first support plate.
(C) a second support plate; (d) a second mirror surface disk attached to the second support plate; and (e) a second mirror surface disk at an outer peripheral edge of the second mirror surface disk. And (g) biasing means for biasing the cavity ring toward the first mirror surface disk, and (g) the second mirror surface disk. Wherein the hardness of the outer peripheral surface of the cavity ring facing the cavity ring differs from the hardness of the inner peripheral surface of the cavity ring facing the second mirror surface disk. 2. The disk molding die according to claim 1, wherein the outer peripheral surface of the second mirror surface disk is coated with a coating layer made of a material having high hardness. 3. A coating layer made of a material having high hardness is coated on the inner peripheral surface of the cavity ring.
2. The disk molding die according to 1. 4. The disk molding die according to claim 1, wherein a coating layer made of a material having a low hardness is coated on an outer peripheral surface of said second mirror disk. 5. A coating layer made of a material having low hardness is coated on an inner peripheral surface of the cavity ring.
2. The disk molding die according to 1.