JP3368308B2 - Disc 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 a disk molding machine for molding a disk such as an optical disk using a resin injection molding method.

[0002]

2. Description of the Related Art When molding an optical disk, it is common to use an injection molding method for molding a product by injecting a resin into a cavity in a mold in terms of both productivity and cost. FIG. 1 shows a conventional disk molding machine using such an injection molding method (for example, JP-A-1-176536).
2 is a perspective view of the mold 1. FIG. The mold 1 has a structure in which two mold pieces 1a and 1b are combined, and a cavity 2 for manufacturing a product (optical disk) in the center.
have. Further, a resin injection port 3 for injecting a resin as a material is opened on a side surface of the mold 1. The resin injection port 3 and the cavity 2 are communicated with each other, and the communication passage is narrowed on the resin injection port 3 side and widened on the cavity 2 side by the guide member 4. A stamper 5 for transferring the recording surface to the disk substrate is supported and fixed to the inner wall surface of the mold 1 by a stamper retainer 6.

Further, between the guide member 4 on the inner wall surface of the mold 1 and the stamper retainer 6 is the tip of the air supply pipe 11 of the air blow circuit 10 for separating the product from the inner wall of the mold 1. The air outlet 12 is open. Air supply pipe 11
Is extended to the outside of the mold 1, and its base end is connected to an air blow source 13 that stores pressurized air. A valve is installed in the middle of the air supply pipe 11 in order from the air blow source 13.
14, pressure regulator 15, valve 16, flow regulator 17, solenoid valve 18,
It is provided as a constituent member of the air blow circuit 10.

In the disk molding machine having such a structure, resin is injected from the injection machine (not shown) into the cavity 2 through the resin injection port 3 to mold the optical disk. After the molding, the air blow circuit 10 blows pressurized air onto the inner wall surface of the mold 1 to separate the product from the inner wall of the mold 1.

FIG. 3 is a schematic view showing the structure of another conventional disk molding machine using the injection molding method. In FIG. 3, the parts having the same numbers as those in FIG. 1 described above indicate the same members. In this conventional disk molding machine shown in FIG. 3, in addition to the air blow circuit 10 in the above-mentioned conventional example, a mold 1 is used.
A decompression circuit 20 for decompressing the inside is provided, and an exhaust port 22 which is a tip of an exhaust pipe 21 of the decompression circuit 20 opens at the outer end of the cavity 2. A base end of the exhaust pipe 21 is connected to a decompression pump 23 as a decompression source, and an electromagnetic valve 24 is provided as a constituent member of the decompression circuit 20 in the middle of the exhaust pipe 21. This decompression circuit 20 has a mold 1 (cavity 2).
It is provided for decompressing the inside of the mold 1 for the purpose of speeding up the filling of the resin into the inside or for sucking the gas generated from the injected resin. When the resin is injected into the cavity 2, the decompression circuit 20 is activated, and when the molding of the product is completed, the air blow circuit 10 is activated.

[0006]

While a resin is injected into a cavity of a mold to manufacture a product, a mold clamping force is applied to the mold to close the mold. When the output becomes large or the mold clamping force fluctuates and decreases, the mold may open a little. In such a case, the product has a small degree of freedom in the mold (cavity), the product repeatedly contacts the inner wall surface of the mold, and in the case of an optical disc, the groove or pit has two degrees of freedom. Defects observed as hitting occur. Particularly in the case of an optical disc, since there is a portion for managing disc information in the inner peripheral portion of the recording area, such double striking is not allowed.

When a conventional disk molding machine is used to mold an optical disk by changing molding conditions such as resin injection speed and injection amount, resin melting temperature, mold clamping force, etc. The above-mentioned double strike occurs in%. Even with a conventional disk molding machine, it is possible to mold a non-defective product without double pressing if the range of molding conditions is narrowed, but there is a problem in that the molding conditions must be finely adjusted. Therefore, there is a demand for development of a disk molding machine capable of molding a non-defective product that does not have double punching under a wide range of molding conditions.

The present invention has been made in view of the above circumstances, and it is possible to suppress the degree of freedom of the product by closely contacting the product with the inner wall surface of the mold during molding, and to strike the groove or pit twice. It is an object of the present invention to provide a disk molding machine that can prevent and improve the yield rate.

[0009]

DISCLOSURE OF THE INVENTION A disk molding machine according to the present invention is characterized by comprising a pressure reducing circuit for bringing a disk being molded into close contact with a mold. In addition to this decompression circuit, a blow circuit for separating the molded disk from the mold is also provided, and the decompression circuit and the blow circuit are switched so that decompression processing and pressurization processing are switched. Characterize.

[0010]

In the disk molding machine of the present invention, when the mold is closed, that is, during molding, the disk under molding is adsorbed to the inner wall surface of the mold by the action of the decompression circuit so as to be in close contact therewith. Then, the degree of freedom of the disk during molding is lowered, the disk during molding does not repeatedly hit the inner wall surface of the mold, double hitting of the groove or pit is prevented, and the non-defective rate is improved. In addition to the decompression circuit, a blow circuit is provided, and the decompression circuit is activated to start decompression processing from the time when the resin is filled into the mold, and the molding process is completed and the product is taken out of the mold. At this time, the product is easily peeled from the mold by applying a pressure treatment by a blow circuit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments.

(First Embodiment) FIG. 4 is a schematic diagram showing the construction of a first embodiment of the disk molding machine of the present invention, and FIG.
5 is a sectional view taken along line VV of FIG. 4 and 5,
The same parts as those in FIG. 1 are designated by the same reference numerals. 1 is shown in FIG.
The mold has a structure similar to that shown in FIG. 1, has a cavity 2 for molding a product (optical disk) in the center, and has a resin injection port 3 on the side surface. The resin injection port 3 and the cavity 2 are communicated with each other by the guide member 4 so as to widen from the resin injection port 3 side to the cavity 2 side. A stamper 5 is supported and fixed to the inner wall surface of the mold 1 by a stamper retainer 6.

Further, between the guide member 4 on the inner wall surface of the mold 1 and the stamper retainer 6, an opening 32 which is the tip of the air inlet / outlet pipe 31 is provided. The air inlet / outlet pipe 31 is common to the decompression circuit 30, which is a characteristic part of the present invention, and the air blow circuit 10 similar to the conventional example.
From 33, an air discharge pipe 34 of the pressure reducing circuit 30 and an air supply pipe 11 of the air blow circuit 10 are branched. Air exhaust pipe
The base end of 34 is connected to a vacuum pump 35 as a vacuum source. Further, in the middle of the air supply pipe 11, similar to the above-mentioned conventional example, the valve 14, the pressure regulator 15, the valve 16, the flow regulator 1
7, solenoid valve 18 is provided, the base end of which is an air blow source 1
Connected to 3.

The decompression circuit 30 is provided so that the optical disk being molded is brought into close contact with the inner wall surface of the mold 1, while the air blow circuit 10 is similar to the conventional example, in that the product is finished after the formation. It is provided for easy separation from the inner wall surface of the. The decompression process by the decompression circuit 30 and the pressurization process by the air blow circuit 10 are performed by the electromagnetic changeover switch 33.
Can be switched by.

Next, the operation will be described. While applying a predetermined mold clamping force to the mold 1, the resin is injected from the resin injection port 3 into the cavity 2 by using an injection machine (not shown). At this time, from the time when the cavity 2 of the mold 1 is filled with the resin, the electromagnetic changeover switch 33 is switched to the pressure reducing circuit 30 side to drive the pressure reducing pump 35 to start the pressure reducing process. Continue to drive the vacuum pump 35. When the molding process is completed, the mold clamping force is released, the mold 1 is opened, the electromagnetic changeover switch 33 is switched to the air blow circuit 10 side, and the air blow circuit 10 is operated to perform the pressurizing process.
The product is peeled off from the inner wall surface of and the product is taken out from the cavity 2.

In the present embodiment, the cavity 2 of the mold 1 is depressurized during the molding process so that the optical disc in the middle of molding is molded by the mold 1.
Since it is made to stick to the inner wall surface of the mold, even if the mold clamping force or the ejection force of the resin fluctuates and the mold 1 is opened a little, the optical disk being molded is surely adhered to the inner wall surface of the mold 1. Therefore, the stamper 5 is not repeatedly hit by the optical disk being molded, and the groove or pit cannot be hit twice. Also, after molding is completed, the air blow circuit
Since air is sent at 10, the product can be easily peeled from the mold 1.

(Second Embodiment) FIG. 6 is a schematic view showing the structure of a second embodiment of the disk molding machine of the present invention.
4, the same parts as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. In the second embodiment, the aspirator 36 is used as the pressure reducing source of the pressure reducing circuit 30. Aspirator
36 is connected to the air blow source 13 of the air blow circuit 10 via a supply pipe 37 provided with a valve 38 in the middle. If pressurized air is used as the decompression medium of the aspirator 36,
Since the air blow source 13 of the air blow circuit 10 can be shared as in the configuration shown in FIG. 6, it is possible to add a special device other than the aspirator 36 to the existing air blow circuit 10 and to reduce the pressure reducing circuit. 30 can be configured easily.

Also in the second embodiment, the aspirator 36 of the decompression circuit 30 is driven during the molding of the optical disk to perform the decompression process, and when the molding process is completed, the air blow circuit 10 is operated to switch to the pressure process. The other operations are the same as those in the first embodiment described above, and the description thereof will be omitted.

(Third Embodiment) FIG. 7 is a schematic view showing the structure of a third embodiment of the disk molding machine of the present invention.
4, the same parts as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. In the third embodiment, the electromagnetic changeover switch
In the middle of the exhaust pipe 34 between the 33 and the decompression pump 35, a decompression container
39 are provided. In this embodiment, the decompression circuit 30 includes a decompression container.
Since 39 is provided, the decompression force in the decompression process can be increased, and the adsorption effect of the optical disc during molding can be further improved. In addition, the decompression force can be adjusted by adjusting the volume of the decompression container 39. The operation of the third embodiment is similar to that of the above-described first embodiment, and the description thereof will be omitted.

In the above embodiment, the air inlet / outlet pipe 31
The opening 32 at the tip of the disk is provided near the center of the product, and the groove and pit on the inner peripheral side where the disc management area exists
Although the hitting is mainly prevented, the opening 32 may be provided near the peripheral edge to mainly prevent the hitting twice of the groove and the pit on the outer peripheral side. Further, although pressurized air is used in the blow circuit, nitrogen gas may be used.

[0021]

As described above in detail, since the disk molding machine of the present invention is provided with the pressure reducing circuit for bringing the disk being molded into close contact with the inner wall surface of the mold, delicate molding conditions can be set. Even in the case of not doing so, it is possible to prevent the disk being molded from repeatedly hitting the inner wall surface of the mold, prevent double striking of the groove or pit, and improve the product yield. Also, peel the molded disc from the mold.
Equipped with a blow circuit to separate, decompression circuit and blow circuit
Since it was configured to switch between and,
A series of processes for molding (disc molding by resin injection →
Efficiently removes post-form products from the mold (stamper)
I can.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a conventional disk molding machine.

FIG. 2 is a perspective view of a mold in a disk molding machine.

FIG. 3 is a schematic view showing the configuration of another conventional disk molding machine.

FIG. 4 is a schematic view showing a configuration of a first embodiment of a disk molding machine of the present invention.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a schematic view showing the configuration of a second embodiment of the disk molding machine of the present invention.

FIG. 7 is a schematic view showing the configuration of a third embodiment of the disk molding machine of the present invention.

[Explanation of symbols]

1 mold 2 cavities 3 Resin injection port 5 stampers 10 Air blow circuit 30 Pressure reducing circuit 32 openings 33 Electromagnetic changeover switch 35 vacuum pump 36 Aspirator 39 Decompression container

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-160627 (JP, A) JP-A-3-293107 (JP, A) JP-A-5-212751 (JP, A) Actual Kaihei 4- 60414 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A resin into the mold by an injection molding machine for molding a disc, and decompression circuitry for tightly <br/> wear disc in the compact to the die, the disc after molding The money
A blow circuit for peeling from the mold, the pressure reducing circuit, and
A disk molding machine, comprising: switching means for switching the blow circuit . 2. Attaching a stamper having a transfer pattern
Opening at the tip of the pressure reducing circuit on the inner surface of the mold on the closed side
The molding machine for a disk according to claim 1, further comprising: