JP2003019734A - Mold for molding disk and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the attaching state of a stamper to a stamper attaching surface from becoming bad and to also prevent the generation of molding failure. SOLUTION: The mold for molding the disk has a first mirror surface plate, a second mirror surface plate arranged in opposed relation to the first mirror surface plate and having the stamper attaching surface 56S and the stamper 37 attached to the stamper attaching surface 56S. Surface processing is applied to the stamper attaching surface 56S and a modified part AR having hardness higher than that of the matrix of the second mirror surface plate is formed over a predetermined range from the stamper attaching surface 56S. In this case, since surface processing is applied to the stamper attaching surface 56S and the modified part AR is formed, the stamper attaching surface 56S is not locally abraded even if impurities or the like are come into direct contact with the stamper attaching surface 56S. Accordingly, the stamper 37 can be stably supported by the second mirror surface plate.

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 and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a resin as a molding material supplied into a heating cylinder is melted,
The cavity is formed in the disk molding die, and the resin is filled (solidified) and solidified to mold a disk as a molded product.

The disk molding die is composed of a fixed side assembly and a movable side assembly. The movable side assembly is brought into contact with and separated from the fixed side assembly by a mold clamping device, and the mold is closed, the mold is clamped and the mold is clamped. You can open it. Then, the stamper is detachably attached to the disk plate of the movable side assembly, and when the cavity space is filled with the resin, the irregularities formed as the information processing surface on the stamper are transferred to the resin.

FIG. 2 is a sectional view of a conventional disk molding die, and FIG. 3 is a sectional view showing a main part of the conventional disk molding die.

In the figure, reference numeral 12 is a fixed side assembly attached to a fixed platen (not shown). The fixed side assembly 12 includes a base plate 15 and the base plate 1.
5, a disc plate 16 attached to the disc 5, a cavity ring 17 attached to the outer periphery of the disc plate 16 to form the outer peripheral edge of the disc, the disc plate 16
A sprue bush 24 and the like arranged so as to face the through hole 18 of the base plate 15 is provided at the center of the.

At the center of the sprue bush 24, a sprue 26 for passing a resin (not shown) injected from an injection nozzle of an injection device (not shown) is formed. The front end (the left end in FIG. 2) of the sprue bush 24 is disposed so as to face the cavity C, and the die 28
Is formed.

Reference numeral 32 designates a movable side assembly attached to a movable platen (not shown). The movable side assembly 32 extends through the base plate 35, the disc plate 36 fixed to the base plate 35, and the base plate 35 and the disc plate 36.
Cut punch 48 having a shape corresponding to the die 28
Consists of. In order to move the cut punch 48 back and forth (move in the left-right direction in FIG. 2), the base plate 35
A cylinder 44 is formed in the cylinder 44, and a piston 51 integrally formed with the cut punch 48 is arranged in the cylinder 44 so as to be movable back and forth, and an oil (not shown) is provided behind the piston 51 (to the left in FIG. 2). A chamber is formed. Further, a cut punch return spring (not shown) is arranged in front of the piston 51 (right side in FIG. 2), and the cut punch return spring biases the piston 51 rearward.

A stamper 37 is attached via a hard layer 39 to the front end face (right end face in FIGS. 2 and 3) of the disc plate 36, which faces the disc plate 16, that is, the stamper attachment face 36S. The hard layer 39 is formed by coating the stamper mounting surface 36S with a material having hardness and wear resistance higher than that of the material forming the disk plate 36 (Patent No. 252).
No. 1258).

The stamper 37 is provided with concavities and convexities as an information processing surface so as to face the disk plate 16. Further, a mold clamping device (not shown) is arranged behind the movable platen. By operating the mold clamping device and advancing and retracting the movable platen, it is possible to perform mold closing, mold clamping and mold opening of the disk molding mold.

In the disk molding die having the above structure,
After the mold is closed by operating the mold clamping device and the mold is clamped, when the resin is injected from the injection nozzle, the resin is filled into the cavity space C through the sprue 26 and solidified. At this time, the unevenness of the stamper 37 is transferred to the resin, and a molded substrate (not shown) is formed in the cavity C. Then, when the piston 51 is advanced (moved to the right in FIG. 2) by supplying oil to the oil chamber, the cut punch 48 is advanced and enters the die 28. As a result, the molded substrate is perforated to form a disk.

By the way, as the cavity space C is filled with the resin, gas contained in the resin, fine solid impurities, etc. are generated and enter between the stamper 37 and the hard layer 39. , The stamper mounting surface 36S is a hard layer 39
Since it is covered with, the impurities and the like do not come into direct contact with the stamper mounting surface 36S. Therefore,
Since the stamper mounting surface 36S is not locally worn, the stamper 37 can be stably supported by the disc plate 36.

Although the impurities and the like that have entered between the stamper 37 and the hard layer 39 locally wear the rear end surface 37S of the stamper 37, the stamper 37 periodically forms a predetermined number of disks. Since it is designed to be replaced, it is not necessary to form a hard layer on the rear end surface 37S.

[0013]

However, in the above-described conventional disk molding die, since the material forming the hard layer 39 is different from the material forming the disc plate 36, the hard layer 39 is locally peeled off. May be separated. In that case, the peeled portion and the non-peeled portion not only form irregularities on the surface of the hard layer 39, but also in the peeled portion, the stamper mounting surface 36S is exposed and worn by impurities or the like. . Further, as unevenness is formed on the surface of the hard layer 39,
Impurities and the like that enter between the stamper 37 and the hard layer 39 are further increased, and the wear of the rear end surface 37S is promoted.

Therefore, the mounting state of the stamper 37 on the stamper mounting surface 36S is deteriorated, resulting in defective molding.
The yield of discs will be poor.

The present invention solves the above-mentioned problems of the conventional disk molding die and prevents the mounting state of the stamper from being deteriorated on the stamper mounting surface, thus preventing defective molding. It is an object of the present invention to provide a disk molding die that can be prevented and can improve the yield of molded products, and a method for manufacturing the same.

[0016]

Therefore, in the disk molding die of the present invention, the first mirror surface plate and the first mirror surface plate are provided.
And a second mirror surface plate that is provided so as to face the mirror surface plate and has a stamper mounting surface, and a stamper that is mounted on the stamper mounting surface.

Then, the stamper mounting surface is subjected to a surface treatment so as to cover a predetermined range from the stamper mounting surface.
A modified portion having a hardness higher than that of the base material of the second mirror surface plate is formed.

In another disk molding die of the present invention, the surface processing is precision shot peening.

In the method for manufacturing a disk molding die of the present invention, the stamper mounting surface of the second mirror surface plate, which is disposed so as to face the first mirror surface plate, is mirror-finished, and the mirror-finishing is performed. After the stamper mounting surface is subjected to surface treatment,
The hardness is 2nd over the specified range from the stamper mounting surface.
A modified portion higher than the base material of the mirror surface plate is formed, and the stamper is attached to the stamper attachment surface after the surface processing.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described 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. 4 is a sectional view of a disk molding die according to an embodiment of the present invention.

In the figure, 12 is a fixed side assembly attached to a fixed platen (not shown). The fixed side assembly 12 includes a base plate 15 and the base plate 1.
5, a disc plate 16 as a first mirror surface plate, a cavity ring 17 attached to the outer periphery of the disc plate 16 for forming an outer peripheral edge of a disc as a molded product, and a center of the disc plate 16 The base plate 15 is provided with a sprue bush 24 and the like arranged to face the through hole 18.

At the center of the sprue bush 24, a sprue 26 for passing a resin (not shown) as a molding material injected from an injection nozzle of an injection device (not shown) is formed. Further, the front end (the left end in FIG. 4) of the sprue bush 24 is disposed so as to face the cavity C, and a die 28 is formed.

Reference numeral 32 denotes a movable side assembly attached to a movable platen (not shown). The movable side assembly 32 penetrates the base plate 35, a disk plate 56 that is fixed to the base plate 35, and is disposed so as to face the disk plate 16 as a second mirror surface plate, and the base plate 35 and the disk plate 56. And a cut punch 48 having a shape corresponding to that of the die 28. A cylinder 44 is formed in the base plate 35 for moving the cut punch 48 forward and backward (moving to the left and right in FIG. 4).
A piston 51, which is integrally formed with the cut punch 48, is provided therein so as to be able to move forward and backward, and an oil chamber (not shown) is formed behind the piston 51 (to the left in FIG. 4). Further, a cut punch return spring (not shown) is arranged in front of the piston 51 (right side in FIG. 4), and the cut punch return spring biases the piston 51 rearward.

The stamper 37 is directly attached to the front end surface (right end surface in FIGS. 1 and 4) of the disk plate 56 facing the disk plate 16, that is, the stamper mounting surface 56S. The stamper 37 is provided with concavities and convexities as an information processing surface so as to face the disk plate 16. Further, a mold clamping device (not shown) is arranged behind the movable platen. By operating the mold clamping device and advancing and retracting the movable platen, it is possible to perform mold closing, mold clamping and mold opening of the disk molding mold.

In the disk-molding die having the above structure,
After the mold is closed by operating the mold clamping device and the mold is clamped, when the resin is injected from the injection nozzle, the resin is filled into the cavity space C through the sprue 26 and solidified. At this time, the unevenness of the stamper 37 is transferred to the resin, and a molded substrate (not shown) is formed in the cavity C. Then, when the piston 51 is advanced (moved to the right in FIG. 4) by supplying oil to the oil chamber, the cut punch 48 is advanced and enters the die 28. As a result, the molded substrate is perforated to form a disk.

By the way, as the resin is filled in the cavity space C, gas contained in the resin, fine solid impurities and the like are generated and enter between the stamper 37 and the disc plate 56. When the impurities and the like contact the stamper mounting surface 56S and locally wear the stamper mounting surface 56S, the stamper 37 is moved to the disk plate 5
6 makes it impossible to stabilize and support.

Therefore, the stamper mounting surface 56S has a first
The surface finish is mirror finished and the surface roughness is 0.
02 [μm]. Next, precision shot peening (WP) is performed on the stamper mounting surface 56S as a second surface processing.
C) is applied to modify a predetermined range from the stamper mounting surface 56S, for example, a range of several tens [μm]. The modified range, that is, the hardness of the modified portion AR is set higher than the hardness of the base material of the disc plate 56, and
50 [Hv] or more. Further, the toughness of the modified portion AR is also made higher than that of the base material of the disc plate 56.

Therefore, a shot made of a minute spherical object such as alloy steel or carbon steel is directed toward the stamper mounting surface 56S after being mirror-finished by a spraying machine such as a compressed air type or a centrifugal type. Inject and collide. The hardness of the shot is set higher than the hardness of the base material of the disc plate 56. In this case, for example, the particle size of the shot is 40 to 200 [μm], and the injection speed of the shot is 10
It is set to 0 [m / s] or more. In addition, the disc plate 5
6 is made of steel, stainless steel, special steel or the like, and is formed by casting, forging or the like.

The shot bounces after hitting the stamper mounting surface 56S. Then, the speed of the shot after the collision becomes lower than the speed of the shot before the collision, the kinetic energy of the shot becomes small, and the shot energy is converted into thermal energy. Along with this, the portion of the stamper mounting surface 56S that is deformed by the collision is heated, and the base material of the disk plate 56 is heated to a temperature equal to or higher than the transformation point, for example, 870 to 870.
At 900 [° C.], martensite transformation occurs, and a martensite structure of high hardness is formed that is free from tempering deformation, quenching cracking deformation, etc., that is composed of martensite. Further, inside the martensite structure, a substructure having a high hardness and a high toughness, which is a mixture of martensite and bainite while being cooled to room temperature, is formed. Then, inside the lower structure, a quench cracking deformation made of bainite,
A bainite structure free from bending deformation and the like is formed, and the martensite structure is tempered around 400 [° C.] and decomposed to form a secondary troostite structure having high toughness. The modified portion AR is composed of a martensite structure having a high hardness, a lower structure having a high hardness and a high toughness, a bainite structure free from quenching crack deformation, bending deformation and the like, and a secondary troostite structure having a high toughness.

In this case, the surface roughness of the stamper mounting surface 56S becomes about 0.2 [μm] with the precision shot peening, but the stamper mounting surface 56S is
Since it has been mirror-finished in advance, the surface roughness does not locally vary. Therefore, it is possible to prevent the mounting state of the stamper 37 on the stamper mounting surface 56S from being deteriorated.

Although the impurities and the like contact the rear end surface 37S and locally wear the rear end surface 37S, the stamper 3
No. 7 does not need to be subjected to precision shot peening treatment on the rear end surface 37S because it is regularly replaced when a predetermined number of disks are molded.

As described above, since the stamper mounting surface 56S is subjected to the precision shot peening treatment and the modified portion AR is formed, even if impurities or the like directly contact the stamper mounting surface 56S, the stamper mounting surface 56S is still exposed. It does not wear locally. Therefore, the stamper 37 can be stably supported by the disc plate 56.

Further, since the material forming the reforming portion AR and the material forming the disc plate 56 are the same, the reforming portion AR does not peel off. Therefore, no unevenness is formed on the stamper mounting surface 56S, and the base material of the disc plate 56 is not exposed and worn by impurities or the like. As a result, it is possible to prevent the mounting state of the stamper 37 on the stamper mounting surface 56S from being deteriorated, prevent molding defects from occurring, and improve the disk yield.

Further, since no unevenness is formed on the stamper mounting surface 56S, the stamper 37 and the disc plate 5
It is possible to prevent an increase in the amount of impurities and the like that enter between 6 and 6. Therefore, it is possible to prevent the wear of the rear end surface 37S from proceeding.

In the present embodiment, the stamper 37 is attached to the disk plate 56 on the movable platen side, but the disk plate 16 on the fixed platen side is attached.
A stamper can be attached to.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[0038]

As described above in detail, according to the present invention, in the disk molding die, the first mirror surface plate and the first mirror surface plate are disposed so as to face each other, and the stamper is attached. A second mirror surface plate having a surface and a stamper attached to the stamper attachment surface.

Then, the stamper mounting surface is subjected to a surface treatment so as to cover a predetermined range from the stamper mounting surface.
A modified portion having a hardness higher than that of the base material of the second mirror surface plate is formed.

In this case, since the stamper mounting surface is surface-treated to form the modified portion, the stamper mounting surface is locally worn even if impurities or the like come into direct contact with the stamper mounting surface. There is no such thing. Therefore, the stamper can be stably supported by the second mirror plate.

Further, since the material forming the modified portion and the material forming the second mirror surface plate are the same, the modified portion does not peel off. Therefore, no unevenness is formed on the stamper mounting surface, and the base material of the second mirror plate is not exposed and abraded by impurities or the like. As a result, it is possible to prevent the mounting state of the stamper on the stamper mounting surface from being deteriorated, prevent defective molding from occurring, and improve the yield of molded products.

Further, since no unevenness is formed on the stamper mounting surface, it is possible to prevent an increase in impurities and the like entering between the stamper and the second mirror surface plate. Therefore, it is possible to suppress the wear of the rear end surface of the stamper.

[Brief description of 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 cross-sectional view of a conventional disk molding die.

FIG. 3 is a cross-sectional view showing a main part of a conventional disk molding die.

FIG. 4 is a cross-sectional view of a disk molding die according to the embodiment of the present invention.

[Explanation of symbols]

16,56 disk plate 37 Stamper 56S Stamper mounting surface AR reformer

Continued front page    (72) Inventor Yuichi Inada             1 731 Naganumahara-cho, Inage-ku, Chiba-shi, Chiba               Sumitomo Heavy Industries, Ltd. Chiba Works F term (reference) 4F202 AH38 AH79 CA11 CB01 CK06

Claims (3)

[Claims] 1. (a) a first mirror surface plate, (b) a second mirror surface plate that is disposed so as to face the first mirror surface plate, and has a stamper mounting surface; and (c) the stamper. And a stamper attached to a mounting surface, and (d) the stamper mounting surface is surface-treated to have a hardness higher than that of the base material of the second mirror plate over a predetermined range from the stamper mounting surface. A metal mold for forming a disk, wherein a part is formed. 2. The disk molding die according to claim 1, wherein the surface processing is precision shot peening. 3. A stamper mounting surface of (a) a second mirror surface plate disposed so as to face the first mirror surface plate is mirror-finished, and (b) a stamper mounting after the mirror surface finish is applied. Surface is processed to form a modified portion having hardness higher than that of the base material of the second mirror surface plate over a predetermined range from the stamper mounting surface, and (c) the stamper mounting surface after the surface processing is applied. A method for manufacturing a disk-molding die, characterized in that a stamper is attached to the.