JP3008392B2 - Optical disk molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk molding machine for molding an optical disk such as a mini disk which is a disk-shaped optical record carrier.

[0002]

2. Description of the Related Art Conventionally, as a molding apparatus for molding an optical disk such as a compact disk, which is a resin disk-shaped optical record carrier, for example, the one described in Japanese Patent Publication No. 62-45809 is known. I have. In the molding apparatus described in this publication, a mold composed of a set of a fixed mold and a movable mold is attached to one molding machine to mold one optical disk. An optical disk as a product has an opening in the center, but the optical disk is initially formed in a mold in a shape in which the opening is closed.
The opening hole is formed by punching with a punch provided on the movable mold side. The driving source of the punch is
Although a cylinder device is used, this cylinder device is provided on the movable mold side. Further, after punching with a punch, the resin and the molded optical disk in the opening hole portion are stepwise protruded from the movable mold side and released from the movable mold side by a protruding pin and a protruding collar provided on the movable mold side as the mold is opened. I have to. The drive source for the ejection pin and the ejection collar is a mold clamping cylinder device of a molding machine.

[0003]

However, in the above-mentioned conventional molding apparatus, one optical disk is molded at one time by one molding machine, that is, since one optical disk is formed, the productivity is low. . Therefore, in order to enhance the productivity, for example, as described in Japanese Patent Application Laid-Open No. 63-270112, it is conceivable to employ a multi-cavity method. By the way, optical discs are required to have high precision, for example, including a stamper which is a plate for transferring information to be recorded onto an optical disc to be molded, including a stamper which is a plate for fixing the fixed type and the movable type. High precision is required. However, if a plurality of cavities are formed by a set of a fixed mold and a movable mold for multi-cavity production, in addition to attaching the fixed mold and the movable mold to the molding machine, each of the fixed mold and the movable mold is also required. Accurate setting of the positional relationship between the plurality of cavities is required, and alignment of the fixed mold side and the movable mold side for each cavity becomes troublesome. At the same time, the maintenance of the stamper becomes troublesome.

In the case of multi-cavity molding, a runner is required to branch the flow of the molten resin from one nozzle of the molding machine to each of a plurality of cavities formed between the fixed mold and the movable mold. Become. If this runner is a cold runner, the resin solidified in the runner after one molding cannot be reused, but if the number of samples is increased, for example, four, the overall length of the runner becomes longer. Resin waste increases. Therefore, in order to eliminate waste of the resin, it is desirable to adopt a hot runner method in which the resin in the runner is always kept in a molten state, as described in Japanese Patent Application Laid-Open No. 63-270112.

[0005] Even when the hot runner method is adopted, if the gate from the runner to the cavity is located as a direct gate at the periphery of the opening and the opening is formed simultaneously with the filling of the cavity with the resin,
Since the gates are unevenly distributed, the optical characteristics of the molded optical disk deteriorate. To avoid this, the gate should also be a disk gate at the position that will be the opening hole,
It is better to cut the optical disk and the resin in the opening hole portion at this gate position.

The molding apparatus described in Japanese Patent Application Laid-Open No. 63-270112 employs a configuration in which a fixed nest and a movable nest are divided for each cavity, but the fixed nest is attached to a fixed mold plate. A configuration is adopted in which it is fitted and fixed in the formed opening and directly connected to the manifold. Therefore, there is a problem that the holding of the fixed side insert itself is uncertain because the manifold is movable for gate cutting.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and in an optical disc molding machine, it is possible to perform multi-cavity molding by a hot runner method, and to provide a fixed mold side and a movable mold side for each cavity. An object of the present invention is to make it possible to accurately and easily perform the centering of a hot runner and to easily install a manifold and a gate cut mechanism for a hot runner.

[0008]

In order to achieve the above object, the present invention provides an optical disk molding machine for molding an optical disk having an opening hole at the center thereof. A fixed plate to which the fixed die is attached among the fixed die and the movable die, a movable plate to which the movable die can be attached so as to be able to approach and separate from the fixed plate, and inject molten resin provided on the fixed plate side. The fixed plate is composed of a fixed plate body and a fixed-side mounting board fixed to the fixed plate body via a spacer block, and the movable plate is fixed to the movable plate body and the movable plate body. And a runner for branching the flow of the molten resin from the nozzle to each of the plurality of cavities. A manifold having a heater for keeping the resin in a molten state is provided between the fixed plate body, the spacer block, and the fixed-side mounting substrate, and a primary gate which is communicated with the runner and is opened and closed by a valve, and a drive source for driving the valve Is provided on the fixed platen side, and a secondary gate for communicating the primary gate to the cavity is provided on the fixed mold, and a gate cutting mechanism for cutting the optical disk formed by the secondary gate and the resin in the opening portion. A drive source for a protruding mechanism for releasing the molded optical disk and the resin of the opening portion from the movable mold side is provided on the movable board side, and the fixed-side mounting board and the movable side are provided. A plurality of sets of fixed molds and movable molds each forming one cavity can be independently attached to the mounting board.

[0009]

In the optical disk molding machine of the present invention, when molding an optical disk, a plurality of sets of fixed molds and movable molds are independently mounted on a fixed-side mounting board of a fixed board and a movable-side mounting board of a movable board. Then, the fixed platen and the movable platen are brought closer to each other, the fixed die and the movable die are clamped, and one cavity in the shape of an optical disc is formed between the plurality of sets of the fixed die and the movable die, respectively. After opening the primary gate on the fixed board side, molten resin is injected from a nozzle on the fixed board side. The flow of the molten resin from this nozzle branches into each cavity in a runner in a manifold provided between the fixed plate body of the fixed plate, the spacer block and the fixed-side mounting substrate, and the primary gate and Resin is filled through the secondary gates. After that, the primary gate is closed by the valve and the gate cut mechanism driven by the drive source on the movable platen side, the secondary gate from the runner to the cavity, the formed optical disk and the opening hole at the center of this optical disk Part of the resin is cut off. Then, the fixed board and the movable board are separated from each other,
The fixed mold and the movable mold are opened.Accordingly, by the protrusion mechanism driven by the drive source on the movable platen side,
The resin in the opening portion is released from the movable die side, and the molded optical disk is released from the movable die side. Thereafter, mold clamping is performed again, and the above molding cycle is repeated. During this time, the resin in the runner is kept in a molten state by heating the heater of the manifold.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the optical disk molding machine of the present invention will be described below with reference to the drawings. In the following description, the upper and lower sides in FIGS. FIG. 4 shows a mini disc 1 which is a kind of optical disc to be molded. This mini disk 1
Has a circular opening 2 in the center. The outer diameter of the mini-disc 1 is 64 mm.

The molding machine has a fixed platen 11 and a movable platen 12, as shown in FIGS. For example, this movable board
Numeral 12 is driven by a hydraulic cylinder device (not shown), and moves toward and away from the fixed platen 11.
The fixed platen 11 includes a fixed platen body 13 and a fixed-side mounting board 15 fixed to the lower side of the fixed platen body 13 via a spacer block 14. There is a nozzle 16 provided at the end of a heating cylinder containing a screw (not shown) for injecting molten resin. On the other hand, the movable platen 12 has a movable platen body 17 and a movable-side mounting board 18 fixed above the movable platen body 17.

The fixed platen 11 has a fixed plate body 13.
A manifold 21 is provided between the spacer block 14 and the fixed-side mounting board 15. This manifold 21
Inside, a runner 22 is formed. This runner 22
Has four outlets 22b that are branched twice from one inlet 22a. Although not shown, the manifold 21 has a built-in heater. A sprue bush 23 is connected to an inlet 22a of the manifold 21. This sprue bush 23
Is a sprue 24 to which the nozzle 16 is connected, and the inside is a sprue 24 communicating with the inside of the inlet 22a. A band heater 25 is provided on the outer peripheral side of the sprue bush 23. Also, the fixed-side mounting board
Below the 15, four gate bushes 26 are provided. These gate bushes 26 have primary gates 27 composed of direct gates at the tips protruding downward from the fixed-side mounting board 15. Also, the fixed-side mounting board
Inside 15, four valve casings 28 are embedded and fixed. Each of these valve casings 28 has a lower part fitted in the gate bush 26,
The upper surface is connected to the manifold 21, and the inside communicates with each outlet 22 b of the runner 22 of the manifold 21. Note that a band heater 29 is built in the valve casing 28. In each of the valve casings 28, a valve 30 including a needle pin for opening and closing the primary gate 27 is supported so as to be vertically movable.
On the other hand, four hydraulic cylinder devices 31 which are driving sources of the valve 30 are provided in the fixed platen body 13.
Each valve 30 penetrating the manifold 21 is connected to a piston 32 that moves up and down of the hydraulic cylinder device 31.

On the other hand, in the movable board main body 17, four hydraulic cylinder devices 36, which are driving sources of the protruding mechanism, are provided at positions facing the respective primary gates 27, respectively. Each of these hydraulic cylinder devices 36 has a piston 37 that moves up and down within a predetermined range by hydraulic pressure.
Also, in the movable-side mounting board 18 of the movable platen 12, four hydraulic cylinder devices that are coaxially located with the hydraulic cylinder devices 36 and are driving sources of the gate cutting mechanism, respectively.
41 are provided respectively. Each of these hydraulic cylinder devices 41 has a piston 42 that moves up and down within a predetermined range by hydraulic pressure. At the same time, a housing is provided below the hydraulic cylinder device 41 in the movable-side mounting board 18.
43 are provided, and the lower flange portion 45 of the transmission rod 44 protruding into the housing 43 is fitted to be vertically slidable within a predetermined range. These projecting transmission rods 44 are urged downward by a spring 46 mounted between the flange portion 45 and the upper surface in the housing 43. It is pushed up by the piston 37 of the cylinder device 36. At the same time, the projecting transmission rod 44 penetrates the piston 42 of the hydraulic cylinder device 41 slidably in the up-down direction.

On the fixed-side mounting board 15, four fixed dies 51 are independently mounted on the lower surface side, while on the movable-side mounting board 18, four movable dies 52 are mounted on the upper surface side. It can be installed independently. Each of the four sets of the fixed mold 51 and the movable mold 52 forms one cavity 53 having the shape of the mini disc 1 at the time of mold clamping. As shown in FIG. 3, each of the fixed dies 51 is movable by a guide pin 54 such as a tapered pin.
Fixed side mounting board with bolt 55
It is fixed at 15. Although not shown, the mounting of each movable mold 52 to the movable-side mounting board 18 is the same.

Each of the fixed molds 51 is provided with a first fixed mold member 56a which abuts on the movable mold 52 at the time of mold clamping, and a second fixed mold member fixed above the first fixed mold member 56a. 56b. An outer peripheral bush 57 is vertically fixed through the center of the first fixed member 56a, and an inner peripheral bush 58 penetrates through the outer peripheral bush 57. The inside of the inner peripheral bush 58 is a sprue 59 communicating with the primary gate 27 of the fixed platen 11. Then, between the bushes 57, 58 and the movable mold 52 during mold clamping,
A secondary gate 60 composed of a disk gate for connecting the sprue 59 to the cavity 53 is formed. Further, located at the lower part of the outer periphery of the outer peripheral bush 57,
An inner peripheral stamper retainer 61 is detachably fixed in the first fixed mold member 56a. On the other hand, the first fixed member 56
An outer peripheral stamper retainer 62 is detachably fixed to the outer peripheral portion of the lower surface of a. These stamper retainers 61 and 62 are configured to detachably fix a stamper facing the cavity 53 to the lower surface of the first fixed mold member 56a. Note that a cooling water channel 63 and an air vent channel 64 are also formed in the first fixed member 56a.

On the other hand, the movable mold 52 includes a first movable mold member 71 which abuts against the fixed mold 51 during mold clamping, and a second movable mold member fixed below the first movable mold member 71. 72,
A third movable mold member 73 fixed below the second movable mold member 72, and a fourth movable mold member 74 fixed below the third movable mold member 73 are provided. I have. A bush 75 penetrates vertically through the center of the first movable member 71. Further, a cooling water passage 76 is formed in the first movable member 71. The bush of the third movable member 73, the second movable member 72, and the first movable member 71
A protruding sleeve pin 81 is slidably penetrated in 75 in the vertical direction. The protruding sleeve pin 81 protrudes around the opening 2 of the mini disk 1
The mini disc 1 is released from the movable mold 52 side. Then, the protruding sleeve pin 81 abuts on a position where the flange portion 82 formed on the lower portion abuts on the upper surface of the fourth movable member 74 and a downward step surface 83 formed in the third movable member 73. It can move up and down between positions. With this, the protruding sleeve pin 81
Is urged downward by a spring 84 mounted between the flange portion 82 and the second movable member 72. In the fourth movable member 74 and the protruding sleeve pin 81, a first gate cutting sleeve pin 86 and a second gate fitted on the outer peripheral upper portion of the first gate cutting sleeve pin 86 are provided. A cutting sleeve pin 87 penetrates slidably in the vertical direction. These gate cutting sleeve pins 86, 87
When the first gate cutting sleeve pin 86 is pushed up by the piston 42 of the hydraulic cylinder device 41 provided on the movable platen 12, the mini disk 1 formed by the secondary gate 60 and the resin in the opening 2 are formed. Is to cut off. The gate cutting sleeve pins 86 and 87 are
The projection 89 is urged downward with respect to the protruding sleeve pin 81, but a flange portion 89 formed below the first gate cutting sleeve pin 86 has an upward step surface formed in the fourth movable mold member 74. By hitting 90, downward movement is regulated. Further, a protruding pin 91 penetrates through the first gate cutting sleeve pin 86 so as to be vertically slidable. This protruding pin
The protrusion 91 is pushed up by the projecting transmission rod 44 on the movable platen 12 so as to pierce the resin in the opening 2 portion cut from the molded mini-disc 1 and move it to the movable mold.
The mold is released from the 52 side. And the protruding pin
91 is urged downward by a spring 92, but the downward movement is restricted by the flange portion 93 formed at the lower portion abutting against the upward step surface 90 in the fourth movable member 74. It has become so.

Next, the operation of the above configuration will be described. When molding the mini-disc 1, four fixed dies 51 are attached to the fixed platen 11 of the molding machine,
Four movable dies 52 are attached to the movable platen 12 of the molding machine. The four sets of the fixed mold 51 and the movable mold 52 are attached to the fixed board 11 and the movable board 12 independently of each other. Then, move the movable plate 12 close to the fixed plate 11, and move the fixed
52 and clamp each. In this state, each set of fixed molds 51
One cavity 53 is formed between the movable mold 52 and the movable mold 52. Then, the valve 30 is raised by driving the hydraulic cylinder device 31, the primary gate 27 is opened, and then the molten resin is injected from the nozzle 16 on the fixed platen 11 side. The molten resin injected from the nozzle 16 is supplied to a sprue 24, a runner 22 in a manifold 21, a valve casing 28,
The water flows from the secondary gate 60 into the cavity 53 through the primary gate 27 and the sprue 59 in the fixed mold 51 sequentially. At this time, the flow of the molten resin flows through the manifold on the fixed platen 11 side.
The runners 22 in the 21 branch from one nozzle 16 to each of the four cavities 53. After the filling of the resin into the cavity 53 is completed, the valve 30 is lowered by driving the hydraulic cylinder device 31, and the primary gate 27 is closed by the valve 30. Thereafter, the hydraulic cylinder device 41 in the movable-side mounting board 18 is pressurized to raise the piston 42. When the piston 42 rises in this way, the piston 42 pushes up the gate cutting sleeve pins 86, 87 of the movable mold 52, and the gate cutting sleeve pins 86, 87 which rise against the bias of the spring 88, At the secondary gate 60, the mini-disc 1
And the resin in the opening 2 are cut off. Next, the movable plate 12 is separated from the fixed plate 11 so that the fixed mold 51 and the movable mold 52 are separated.
And open the mold. When the mold opening progresses to some extent, the hydraulic cylinder device 36 in the movable platen body 17 is pressurized to raise the piston 37. When the piston 37 rises in this way, the projecting transmission rod 44 in the movable-side mounting board 18 is pushed up by the piston 37, and this projecting transmission rod
44 rises against the bias of spring 46. When the projecting transmission rod 44 rises in this way, the projecting pin 91 is pushed up by the projecting transmission rod 44, and the projecting pin 91 that rises against the bias of the spring 92 causes the opening hole 2.
Part of the resin is protruded and separates from the movable mold 52 side. Then, when the projecting pin 91 rises to some extent, the flange portion 93 of the projecting pin 91 comes to push up the projecting sleeve pin 81, and is formed by the projecting sleeve pin 81 which rises against the bias of the spring 88. The mini disc 1 is protruded and separates from the movable mold 52 side.

After the molded mini-disc 1 and the resin in the opening 2 are removed, the pressure applied to the hydraulic cylinder devices 36 and 41 is switched, and the spring 4
By the urging of 6, 84, 88, 92, the projecting transmission rod 44, the gate cutting sleeve pins 86, 87, the projecting pins 91, the projecting sleeve pins 81, etc., descend to return to the initial position. At the same time, mold clamping is performed again, and the above molding cycle is repeated. During that time, the resins in the sprue 24, the runner 22 of the manifold 21, and the valve casing 28 are always kept in a molten state by the heating of the heaters 25 and 29. The stamper is replaced every tens of thousands of moldings, for example.

As described above, according to the configuration of the above-described embodiment, four mini-discs 1 can be simultaneously molded in one molding by one molding machine, and the productivity is improved. Since the mini-disc 1 is small, a larger clamping force is not required as compared with, for example, a molding machine for taking one compact disc. Therefore, a molding machine for taking one compact disc can be used as a molding machine for taking four mini discs. Further, since the hot runner method is adopted, waste of resin can be reduced and molding efficiency is increased, even though the entire length of the runner 22 is long due to the four-cavity method. On the other hand, from the fixed platen 11 to the fixed mold 51
The primary gate 27 is a valve gate, whereas the secondary gate 60 to the cavity 53 of the fixed mold 51 and the movable mold 52 is a disc gate that covers the entire circumference of the opening 2 of the mini disc 1. , Mini disk 1 to be molded
The optical characteristics of can be improved. Then, the fixed mold 51 and the movable mold 52 forming the cavity 53 are divided for each cavity 53, and four sets of the fixed mold 51 and the movable mold 52 are provided for the four cavities 53. And movable type
52 can be attached to the fixed-side mounting substrate 15 of the fixed platen 11 and the movable-side mounting substrate 18 of the movable platen 12 independently of each other. Alignment between the movable mold 52 and the movable mold 52 can be performed accurately and easily, and maintenance of the stamper is also facilitated. As a result, a high-precision mini-disc 1 can be obtained. Further, dividing the fixed mold 51 and the movable mold 52 into the respective cavities 53 makes it possible to dispose the manifold 21 having the runner 22 between the fixed plate body 13 of the fixed plate 11 of the molding machine, the spacer block 14, and the fixed-side mounting board 15. Although it was made possible by providing
As described above, the manifold 21 is provided on the fixed platen 11 side of the molding machine, and in addition to the hydraulic cylinder device 36 which is the drive source of the protruding mechanism, the hydraulic cylinder device 41 which is the drive source of the gate cutting mechanism is moved by the movable of the molding machine. The provision on the side of the panel 12 facilitates installation of the manifold 21 and the gate cutting mechanism. At the same time, the weight of the fixed mold 51 and the movable mold 52 can be reduced.

Further, the primary gate 27 on the fixed board 11 side and the secondary gate 60 on the fixed mold 51 are provided as gates, and the primary gate 27 is opened and closed by the valve 30 provided on the fixed board 11 side. For mounting the fixed type 51
30 misalignment does not matter. Therefore, malfunction of the valve 30 and wear of the valve 30 and the primary gate 27 can be prevented.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the embodiment, the four sets of the fixed mold 51 and the movable mold 52 are directly mounted on the fixed board 11 and the movable board 12 of the molding machine, respectively. May be mounted on a fixed platen or a movable platen. Also,
For general use of the molding machine, the drive source of the manifold or the ejection mechanism or the gate cutting mechanism may be freely detachable. Further, although the optical disk of the above embodiment is a mini disk, the present invention can of course be applied to optical disks other than the mini disk.

[0022]

According to the present invention, in a molding machine for an optical disk for molding an optical disk having an opening hole at the center, comprising a stationary plate to which a stationary die is attached and a movable plate to which a movable die is attached. The movable platen is composed of a fixed platen body and a fixed-side mounting substrate fixed to the fixed platen body via a spacer block. A manifold having a runner from a nozzle on the fixed board to a plurality of cavities is provided between the fixed board main body, the spacer block, and the fixed-side mounting board, and communicates with the runner to drive the primary gate and the valve that is opened and closed by the valve. A drive source is provided on the fixed board side, and a secondary gate that connects the primary gate to the cavity is provided on the fixed mold, and the light molded at the secondary gate position A drive source for a gate cutting mechanism that cuts the disk and the resin in the opening is provided on the movable platen side, and a drive source for a protrusion mechanism that releases the molded optical disk and the resin in the opening from the movable die is used as the drive source. Side, and fixed and movable dies, each forming one cavity, can be mounted on the fixed and fixed mounting boards independently of each other. In addition, the fixed and movable molds can be mounted securely, and the fixed and movable molds can be securely attached. By dividing the fixed and movable molds in each cavity, the center of the fixed mold and movable mold can be aligned for each cavity. And the stamper maintenance is easy, and the molding machine itself has a manifold and gate cutting mechanism. By having a driving source, it is also easily these installation. In addition, a primary gate on the fixed board side and a secondary gate on the fixed board are provided as gates, and the primary gate is configured to be opened and closed by a valve provided on the fixed board side. There is no problem with displacement,
Valve malfunction and wear of the valve and the primary gate can be prevented.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of a disk molding machine according to the present invention.

FIG. 2 is a side view of the whole of the above, and a part thereof is shown in cross section.

FIG. 3 is a front view of the same fixed board side.

FIG. 4 is a perspective view of a mini disc which is an optical disc to be molded.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mini disk (optical disk) 2 Opening hole 11 Fixed board 12 Movable board 13 Fixed board body 14 Spacer block 15 Fixed side mounting board 16 Nozzle 17 Movable board body 18 Moving side mounting board 21 Manifold 22 Runner 27 Primary gate 30 Valve 31 Hydraulic cylinder Device (drive source for valve) 36 Hydraulic cylinder device (drive source for protrusion mechanism) 41 Hydraulic cylinder device (drive source for gate cutting mechanism) 51 Fixed type 52 Movable type 53 Cavity 60 Secondary gate

Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B29L 17:00

Claims (1)

(57) [Claims] An optical disk molding machine for molding an optical disk having an opening hole at a central portion thereof, wherein a fixed die is mounted to a fixed die or a movable die in which a cavity having the shape of the optical disk is formed at the time of mold clamping. A movable plate on which a movable die is attached so as to be able to approach and separate from the fixed plate, and a nozzle provided on the fixed plate side for injecting a molten resin; The movable plate is constituted by a movable plate body and a movable-side fixed substrate fixed to the movable plate body, and the movable plate is provided with a plurality of the nozzles. A manifold having a runner for branching the flow of the molten resin into each of the cavities and having a heater for keeping the resin in the runner in a molten state Provided between the fixed board body, the spacer block and the fixed-side mounting board, a primary gate which is communicated with the runner and is opened and closed by a valve, and a drive source for driving the valve are provided on the fixed board side, A secondary gate for communicating the primary gate to the cavity is provided on the fixed die, and a drive source of a gate cutting mechanism for cutting the optical disk formed by the secondary gate and the resin in the opening portion is provided on the movable platen side. A drive source of a protruding mechanism for releasing the molded optical disk and the resin of the opening hole portion from the movable mold side is provided on the movable platen side, and one cavity is formed in each of the fixed side mounting substrate and the movable side mounting substrate. An optical disc molding machine wherein a plurality of sets of fixed and movable dies can be mounted independently of each other.