JPH01280519A - Disk molding mold - Google Patents

Abstract

PURPOSE:To shorten a molding cycle of a disk, by punching the central hole of the disk under a molten state of a resin material injected within a disk molding cavity by an action of a punch cutter ejection device. CONSTITUTION:Simultaneously with completion of injection operation of a resin material 26 injection operation of a punch cutter 32 is performed to its tip side with an ejection cylinder 70, and a cutter part 34 of the punch cutter 32 is rushed into a recessed part 30. Then resin material 26 is cooled and solidified under an ejected state of the punch cutter 32. In other words, the resin material 26 in a cavity 14 and that in a recessed part 30 side are cut apart from each other by the cutter part 34 of the punch cutter 32 and a cutter part 36 of an opening fringe part of the recessed part 30 under a state where the resin material 26 injected in the cavity 14 is molten state. Since the resin material 26 is cooled under this divided state, a disk 48 whose central hole 52 is punched and the central punched part 56 punched through the disk 48, to those of which information of a stamper 46 is transferred, are solidified and molded into separate bodies.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a disk molding mold used for molding disks such as optical disks and magnetic disks, and particularly relates to a technique for shortening the molding cycle.

(Background Art) Disks (disk substrates) such as optical disks and magnetic disks are usually manufactured by injection molding. In the injection molding, -1 is provided with a sprue bushing fitted into the through hole of the stationary side cavity member, and a sprue bush located coaxially with the sprue bush and passing through the movable side cavity member. a punch cutter disposed so as to be movable in the axial direction in a state where the punch cutter The device includes an ejector sleeve and an ejector pin that is disposed so as to be movable in the axial direction while passing through the punch cutter in the axial direction, and the center hole of the disk is punched out by the protruding operation of the punch cutter. On the other hand, a disk molding die is used in which the disk having the punched center hole and the punched portion of the center hole are respectively separated from the movable cavity member by the protruding operation of the ejector sleeve and the ejector pin. ing.

By the way, conventionally, in such a disc molding mold,
After the resin material injected into the disc molding cavity is cooled and solidified, a punch cutter is projected and operated to punch out the center hole of the disc, and the punch cutter is operated to punch out the center hole. Thereafter, the ejector pin and the ejector sleeve are operated to protrude in sequence, and the resin in the center hole punched portion punched out from the disk and the disk in which the center hole is punched out are respectively separated from the movable side cavity member. . To this end, in the past, the key to shortening the disk molding cycle was how to shorten the time required to eject the punch cutter, as well as the time required to eject the ejector pin and ejector sleeve. That was the point.

However, in this way, the time required for ejecting the punch cutter and the time required for ejecting the ejector pin and ejector sleeve are individually reduced.
Conventional methods for shortening the disk molding cycle have limitations in reducing the time required for ejecting them, so the disk molding cycle cannot necessarily be shortened sufficiently. This was a major factor hindering the improvement of molding efficiency.

(Solution B) The present invention was made against the background of the above-mentioned circumstances, and the problem to be solved is to change the molding cycle of the disc from the conventional one in the above-mentioned disc molding mold. The objective is to further improve the disk molding efficiency compared to the conventional method by shortening the length of the disk.

(Solution Means) In order to solve this problem, a disc molding mold according to the present invention is a disc molding mold as described above, in which a sprue bush is provided with a predetermined position that opens into a disc molding cavity at its tip. The punch cutter is arranged in a fixed position relative to the stationary cavity member so as to form a deep recess, and when the punch cutter is in the protruding state, the cutter portion formed on the outer circumferential surface of the punch cutter is inserted into the sprue bush. A punch cutter is arranged so as to penetrate into the recess formed at the tip, and the ejector sleeve and ejector pin are mechanically connected so that the ejector sleeve and the ejector pin move forward and backward as one. Further, the punch cutter is ejected by a punch cutter ejecting means that operates in conjunction with the injection and filling operation of the resin material into the disc molding cavity, and the punch cutter is ejected by the punch cutter ejecting means. According to the present invention, the center hole of the disk is punched out in a molten state of the resin material injected into the disk molding cavity.

(Function) In such a disc molding die, the punch cutter is operated to protrude by the punch cutter ejecting means which is operated to protrude in conjunction with the injection and filling operation of the resin material, and the punch cutter is operated to protrude in conjunction with the injection and filling operation of the resin material. Since the center hole of the disk is punched out, in other words, the center hole of the disk is punched out by the protruding operation of the punch cutter during the cooling and solidification period of the resin material. The time required for the ejection operation of the punch cutter is completely included in the cooling and solidification time of the resin material, and therefore, the disk molding cycle is shortened by the time required for the ejection operation of the punch cutter.

In addition, in such a disk mold, the ejector sleeve and the ejector pin are moved forward and backward as a unit, so that the movable side cavity member of the disk and its central punched portion is formed by the ejector sleeve and ejector pin. Compared to conventional molds in which the ejector sleeve and ejector pin are ejected and operated in sequence, the ejector sleeve and ejector pin are ejected at the same time, and the time required to eject the ejector sleeve and ejector pin is approximately halved. minutes,
This will shorten the disk molding cycle.

Further, in such a disk molding die, since the sprue bushing is provided in a fixed position relative to the stationary cavity member, the sprue bushing can be attached with an extremely simple structure. Incidentally, in conventional disc molding molds, a central punching operation using a punch cutter was performed after the disc was cooled and solidified, so the punch cutter was retracted by the protruding amount of the punch cutter relative to the stationary cavity member. Therefore, it was necessary to provide a sprue bushing so that the sprue bushing could be mounted, and the structure for mounting the sprue bushing was unavoidably complicated.

(Example) Hereinafter, in order to clarify the present invention more specifically,
One embodiment thereof will be described in detail based on the drawings.

First, in FIG. 1, reference numeral 10 denotes a fixed side mirror plate as a fixed side cavity member, and a disk-shaped disk molding cavity (hereinafter simply referred to as a cavity) between a fixed side mirror plate 10 as a fixed side cavity member and a movable side mirror plate 12 as a movable side cavity member. ) 14, and the fixed mold body 1 is fixed via the back plate 16.
It is fixed at 8. The stationary mold main body 18 is adapted to be attached to a stationary platen (not shown). In this case, the fixed side mirror plate 10° and the back plate 16. The fixed mold body 18 and the like constitute a fixed mold.

Fixed side mirror plate 10. Back plate 16 and fixed mold body 18
A through hole 20 is formed in the through hole 20 to extend concentrically with the cavity 14, and the sprue bush 2 is inserted into the through hole 20 from the fixed mold body 18 side.
2 are arranged.

Then, from the injection nozzle 24 of the injection device to the cavity 14
The resin material 2 is inserted into the sprue bush 22 through the sprue bushing 22.
6 can be ejected.

Here, the sprue bush 22 is fixed to the stationary mold main body 18 at a flange portion 28 formed at its base end, and its distal end surface is a predetermined size larger than the molding surface of the fixed mirror plate 10. It is placed in a retracted position. As a result, a recess 30 having a predetermined depth and opening into the cavity 14 is formed at the tip of the sprue bushing 22. And here, such recess 3
A center hole 52 of a disk 48 (described later) is formed at the opening edge of the disk 48 in cooperation with a cutter portion 34 of a punch cutter 32 (described later).
An annular cutter portion 36 for punching out is formed.

On the other hand, the movable mirror plate 12 that forms the cavity 14 with the fixed mirror plate 10 is fixed to the movable mold body 40 via the back plate 38, and in this movable mold body 40, It is designed to be attached to a movable platen (not shown). Then, the movable mirror plate 12 moves toward and away from the fixed plate by moving the movable plate closer to and away from the fixed plate.
The mold clamping position shown in the figure forms the cavity 14 between the mold opening position and the mold opening position where the cavity 14 is opened. Here, these movable side mirror plate 12. Back plate 38. The movable mold body 40 and the like constitute a movable mold.

Here, the movable side mirror plate 12 and the back plate 38 have through holes 4 passing through them concentrically with the through holes 20.
2 is formed, and an inner stand bar presser 44 is disposed so as to be fitted into this through hole 42. A stamper 46 is disposed, the inner peripheral edge of which is held by the inner stamper holder 44, and the outer periphery of which is held by an outer stamper holder (not shown) for transferring predetermined information onto a disk 48, which will be described later. ing.

Inside the inner stamper holder 44 that holds the inner peripheral edge of the stubber 46, a disk 48, which will be described later, is attached to the stubber 46, that is, on the movable side, in a state where it can move a predetermined distance in the axial direction with respect to the inner stamper holder 44. An ejector sleeve 50 for detaching from the mirror plate 12 is disposed, and on the inner peripheral surface of the ejector sleeve 50, coaxially with the sprue bush 22 and cooperating with the recess 30, there is provided an ejector sleeve 50 which will be described later. The punch cutter 32 for punching a central hole 52 in the disk 48 is slidably fitted therein. Then, by penetrating the punch cutter 32 concentrically and movably in the axial direction, the resin of the center hole punched portion 56 of the disk 48 (to be described later) is removed from the movable side mirror plate 12 (more precisely, from the bond cutter 32). An ejector pin 58 for detachment is provided.

Here, as shown in FIG. 1, the ejector sleeve 50 is integrally connected to the rear end of the ejector pin 58 at its rear end.
8 in the axial direction thereof. Here, with respect to the flange portion 60 provided at the rear end portion of the ejector sleeve 50,
A suitable number of piston rods 64 of ejector cylinders 62 provided in the circumferential direction of the acid ejector sleeve 50 are connected to each other, and the ejector sleeve 50 and the ejector pin 58 are moved to the fixed mold by the protruding operation of the piston rods 64 of the ejector cylinders 62. (Fixed side mirror plate 10) side so that it can be activated. That is, the operation of detaching the disk 48 from the movable side mirror plate 12 by the ejector sleeve 50 and the detachment operation of the central hole punched portion 56 from the movable side mirror plate 12 by the ejector pin 58 are the same as those of the ejector cylinder 62. This is done simultaneously based on the protruding operation of the piston rod 64.

Note that the ejector sleeve 50 and the ejector pin 5
The piston rod 64 of the ejector cylinder 62 is always held at its retracting limit position based on the biasing force of a number of coil springs 66 disposed around the ejector sleeve 50. Only when the is operated to protrude, it is ejected from its retraction limit position toward the fixed mold side.

By the way, the outer diameter of the punch cutter 32 is set to correspond to the inner diameter of the through hole 20 of the fixed side mirror plate 10, and a predetermined length portion of the tip of the outer peripheral surface is defined as a small diameter portion 68. A cutter portion 34 for punching out the central hole 52 of the disk 48 in cooperation with the cutter portion 36 of the recess 30 is formed as a stepped portion between the small diameter portion 68 thereof. The punch cutter 32 is based on its base 02.
．． Due to the protruding cylinder 70 provided in one part, the cutter part 34 on the outer circumferential surface of the cutter part 34 in the recess 30.
6 and a position where the cutter portion 34 protrudes into the recess 30 by a predetermined distance,
As a result, when the protruding cylinder 70 is retracted toward the proximal side, an annular gate 72 is formed between the opening edge of the recess 30 and the opening edge of the recess 30, as shown in FIG. On the other hand, in the state in which it is moved forward toward the tip side, the resin in the recess 30 is separated from the resin in the cavity 14, and a center hole 52 of the disk 48, which will be described later, is punched out.

Here, while the resin material 26 filled into the cavity 14 through the sprue bush 22 and the gate 72 is still in a molten state, that is, before the resin material 26 filled into the cavity 14 is solidified. ,
The protruding cylinder 70 causes the punch cutter 32 to protrude toward its tip. That is, the central hole 52 of the disk 48 is substantially punched out under the molten state of the resin material 26.

Note that, as shown in FIG. 2, the punch cutter 32 is provided with a radial through hole 74 in the middle part in the axial direction, and an ejector pin is provided at the tip side of the through hole 74. It is provided with an insertion hole 78 into which 58 is inserted. As is clear from FIGS. 1 and 3, the ejector pin 58 is connected to the ejector sleeve by a connecting portion 80 disposed within the through hole 74 of the punch cutter 32.
It is integrally connected to 0.

Next, the operation when molding the disk 48 using such a mold will be explained.

That is, in injection molding of the disk 48 using such a mold, first, the ejector sleeve 50 and the ejector pin 58 are held at the rear end limit position by the biasing force of the coil spring 66, and the ejector cylinder 70 is With the punch cutter 32 being retracted to its retracted position (retracted position), the movable platen is moved close to the fixed platen, and the movable die is matched with the fixed die. In other words, the movable mold body 40 is brought into contact with the fixed mold body 18, and as a result, a cavity 14 is formed between the mirror plates 10.12 on the fixed side and the movable side. An annular gate 72 is formed between the opening edge of the recess 30 and the tip of the punch cutter 32 on the movable mold side.

When the mold matching operation is completed, as shown in FIG. A resin material 26 is injected into the cavity 14. Then, at the same time as the injection operation of the resin material 26 is completed, the punch canter 32 is operated to protrude toward the tip side by the ejection cylinder 70, and the cutter portion 34 of the punch cutter 32 is operated as shown in FIG. is forced into the recess 30. The resin material 26 is cooled and solidified under the protruding state of the punch cutter 32.

That is, while the resin material 26 injected into the cavity 14 is still in a molten state, the cutter part 34 of the punch cutter 32 and the cutter part 36 at the opening edge of the recess 30 cut the resin material 26 in the cavity 14. The resin material 26 on the recess 30 side is separated. Then, by cooling the resin material 26 in this divided state, the disk 48 with the center hole 52 punched out, to which the information of the stamper 46 has been transferred, and the center hole punched portion 56 punched out from the disk 48 are separated. It is solidified and molded into separate pieces. Note that the resin material 26 within the recess 30 is compressed by the protruding operation of the punch cutter 32.

After the cooling and solidifying period of the resin material 26 has elapsed, the movable platen is moved away from the fixed platen, the mold is opened, and a disk 48 and a center hole punched portion 56 are formed as shown in FIG. is released from the fixed mirror plate 10.

After the mold opening operation is completed, as shown in FIG. 6, the piston rod 64 of the ejector cylinder 62 is operated to protrude, and the ejector sleeve 50 and the ejector pin 50 are integrally attached to their tip sides. Extrusion is activated. In other words, the disk 48 and the central hole punched portion 56 are simultaneously released from the movable mirror plate 12 (more precisely, from the movable mirror plate 12 and the punch cutter 32) by the ejector sleeve 50 and the ejector pin 58. be. And the movable side mirror plate 1
After the center hole punched portion 56 released from the stamper 2 is removed, the disk 48 is taken out by a predetermined take-out device, thereby obtaining a disk 48 having a center hole 52 onto which the information of the stamper 46 has been transferred. be.

In this way, when using the mold of this example,
During the cooling and solidification process when the resin material 26 is still in a molten state,
The punch cutter 32 performs a substantial punching operation of the center hole 52, and when the disk 48 and the center hole punched portion 56 are separated from the movable mirror plate 12, the ejector sleeve 50 and the ejector pin 58 protrude at the same time. It is activated. Therefore, compared to the case of using a conventional mold in which the punching operation of the center hole 52 is performed after the resin material 26 has cooled and solidified, the molding cycle of the disk 48 is shortened by the time required for the ejecting operation of the punch cutter 32. In addition, compared to the case of using a conventional mold in which the ejector sleeve 50 and the ejector pin 58 are sequentially ejected, the time required for ejecting the ejector sleeve 50 and the ejector pin 58 can be approximately halved. Compared to the case of using a conventional mold, the molding cycle for the disk 48 can be significantly shortened and the molding efficiency can be significantly improved.

Further, in such a mold, as described above, the sprue bushing 22 need only be simply fixed to the stationary mold body 18, so there is an advantage that the mounting structure is simple.

Although one embodiment of the present invention has been described above in detail, this is merely an example, and in the above embodiment, the ejector sleeve 50 and the ejector pin 58 are protruded and operated by a mechanical mechanism, etc. Various modifications may be made without departing from the spirit of the present invention.
It goes without saying that the present invention can be implemented with modifications, improvements, etc.

(Effects of the Invention) As explained above, according to the disk molding die according to the present invention, the punch cutter can be ejected during the cooling and solidifying period of the resin material, and the ejector sleeve and ejector pin can be Since the ejecting operations can be performed at the same time and the time required for these ejecting operations can be halved, the molding cycle of the disc can be greatly shortened and the molding efficiency can be significantly improved. Since the sprue bushing can be arranged in a fixed position relative to the stationary cavity member, the arrangement structure of the sprue bush can be significantly simplified.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part for explaining an embodiment of the present invention, and FIG. 3
This figure is also a cross-sectional view showing the connecting portion between the ejector sleeve and the ejector pin of the embodiment device shown in FIG. 1. Figures 4, 5 and 6 are, respectively,
FIG. 2 is a diagram corresponding to FIG. 1 for explaining the operation of the embodiment device of FIG. 1; 10: Fixed side mirror plate (fixed side cavity member) 12: Movable side mirror plate (movable side cavity member) 14: Disc molding cavity 20: Through hole 22 Varnish blue bush 30: Recess 32: Punch cutter 34.36: Cutter part 46: Stamper 48: Disk 50: Ejector sleeve 52: Center hole 56: Center hole punched part 58: Ejector pin 62: Ejector cylinder

Claims (1)

[Scope of Claims] A sprue bushing fitted into a through hole of a fixed cavity member, and a sprue bushing positioned coaxially with the sprue bushing and moving in the axial direction while penetrating the movable cavity member. an ejector sleeve disposed concentrically with the punch cutter on the outside of the punch cutter and movable in the axial direction of the punch cutter; an ejector pin that is disposed so as to be movable in the axial direction while passing through the ejector sleeve, and the ejector sleeve and the ejector In the disk molding die, the disk having the punched center hole and the punched portion of the center hole are respectively separated from the movable cavity member by the protruding operation of the pin, and the sprue bush is attached to the tip of the disk. to form a recess of a predetermined depth that opens into the disc molding cavity.
The punch cutter is disposed in a fixed position relative to the fixed cavity member, and when the punch cutter is in a protruding state, a cutter portion formed on the outer peripheral surface of the punch cutter enters into a recess formed at the tip of the sprue bushing. The punch cutter is arranged so that the ejector sleeve and the ejector pin are mechanically connected so that the ejector sleeve and the ejector pin move forward and backward as a unit, and the punch cutter is The punch cutter is ejected by a punch cutter ejecting means that operates in conjunction with the injection and filling operation of the resin material into the disc molding cavity, and the disk is formed by the ejecting operation of the punch cutter by the punch cutter ejecting means. A mold for forming a disk, characterized in that the center hole of the disk is punched out under a molten state of the resin material injected into the cavity.