JP2003291179A - Mold device for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold device for molding which can mold a molding by uniforming a thickness. <P>SOLUTION: In a movable mold 2, a core block 46 is fitted to a movable side receiving plate 42. In a fixed mold 1, a cavity block 17 is fitted to a fixed side fitting plate 7. An air ejection cavity insert 62 is fitted to the axial center Z of the core block 46 through steps 61A and 62A. A clearance L formed between the fitting plate 42 corresponding to the space between the axial center side 3A of the product cavity 3 and its peripheral side 3B and the core block 46. Even when a resin flows into the product cavity 3 to expand the vicinity of the axial center Z in the product cavity 3, the expansion is prevented by the fitting of the steps 61A and 62A. On the axial center side 3A of the product cavity, the core block 46 retreats toward the clearance L by the pressure of the resin to increase the distance of the product cavity in the place. The thickness of the molding can be equalized by forming the distance of the axial center side 3A and the distance of the peripheral side in the product cavity 3 to be the same. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die device for molding a thin plate such as an optical disk.

[0002]

Many of the molding die devices used for injection molding of optical disks and the like are mounted on a mold clamping device of a toggle type injection molding machine to perform molding.
The mold clamping device of the toggle type injection molding machine is fixed on a base frame 101 as shown in FIG. 3, a fixed plate 103 to which a fixed mold 102 is attached, and a ring attached to one end of the base frame 101 so as to be movable back and forth. Housing 104 and fixed plate 1
03 and the tie bar 105 that penetrates the four corners of the link housing 104
And a movable plate 107 that is engaged with the tie bar 105 so as to be movable opposite to the fixed plate 103 and that attaches the movable mold 106, and a link that is elastically attached between the movable plate 107 and the link housing 104. It comprises a toggle mechanism 108 and a support member 110 attached to the lower part of the movable plate 107 and attached with a rear roller 109 before rotationally moving on the base frame 101.

Then, the fixed mold 102 and the movable mold 106 provided so as to face the fixed mold 102 are closed to form a product cavity between the fixed mold 102 and the movable mold 106, and the nozzle of the injection molding machine is used. A molten thermoplastic resin, which is a molding material injected from 111, is filled in the product cavity, and after the resin in the product cavity is solidified, the fixed mold 102 and the movable mold 106
The mold is opened and the molded optical disk or the like is taken out.

By the way, when the molding die device is attached to the mold clamping device of the toggle type injection molding machine in this way, and after the mold is closed, the molding material is injected from the nozzle 111 into the thin plate-shaped product cavity, originally, the periphery of the product is closed. The axial cavity side of the product cavity, which is kept at the same distance as the section, expands due to the injection resin pressure, and as shown by the solid line in Fig. 4, the axial center side thickness (almost 579 µm) and the peripheral side thickness of the molded product. (Almost 572μ
There was a risk that m) would be different. Particularly, when the molding die device is attached to the mold clamping device of the toggle type injection molding machine, the toggle mechanism pushes the outer side of the movable plate 107, and the fixed plate 103 serves to escape the injection nozzle 111 of the molding machine. Since there is a large hole 112 in the center, it has been found that the influence of the deflection due to the injection resin pressure in the peripheral portion of the product cavity is smaller than that on the axial side of the product cavity. If the thickness of the molded product varies as described above, inconveniences such as the fact that the focal length of the laser is not fixed in the optical disk occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a molding die device capable of forming a molded product with a uniform thickness.

[0006]

According to a first aspect of the present invention, there is provided a movable die and a fixed die, wherein the movable die has a movable side die plate main body on a movable side attachment plate, and the movable die is In a molding die device for forming a thin plate-shaped product cavity between a fixed mold and a movable mold, the movable side insert is locked to the shaft center of the movable mold plate body, and the shaft center side of the product cavity and its In the molding die device, a gap is formed between the movable side mounting plate and the movable side mold plate body corresponding to the peripheral side.

According to the structure of claim 1, even when the axial center side of the product cavity is widened by the resin pressure during injection,
Since the movable-side insert is locked to the axis of the movable-side mold plate body, the expansion can be suppressed, and the movable-side mold plate body can also be retracted and formed by the gap due to the resin pressure.

According to a second aspect of the present invention, in the surface of the movable-side mold plate body facing the movable-side mounting plate, the facing surface of the product cavity corresponding to the axial center side and the peripheral side thereof is formed. The molding die apparatus according to claim 1, wherein the gap is formed by making the thickness smaller than the thickness of the facing surface corresponding to the peripheral side.

According to this structure, the thickness of the facing surface corresponding to the axial center side of the product cavity and the peripheral side thereof is smaller than the thickness of the facing surface corresponding to the peripheral side. The movable mold plate body can be retracted and molded by the resin pressure due to the gap formed in this way.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in one embodiment of FIGS. 1 and 2, a molding die device is attached to a mold clamping device of a toggle type injection molding machine to perform molding, and 1 is a fixed mold and 2 is a mold.
Is a movable type, and these fixed type 1 and movable type 2 which are mold bodies
Move to each other to open and close, and when the mold is closed, the product cavity 3
Are formed between each other. This product cavity 3
By this, a disk-shaped thin plate-shaped molded product such as an optical disc having a thickness of 0.6 mm or less is molded.

The fixed mold 1 comprises a fixed side mold plate 6 and a fixed side mounting plate 7 fixed to the surface of the fixed side mold plate 6 opposite to the movable mold 2. The fixed-side mounting plate 7 is attached to the fixed platen (fixed-side platen) 103 of the mold clamping device of the toggle-type injection molding machine. A sprue bush 8 to which the nozzle of the injection molding machine is connected is fixed by a bolt 9 to the central portion of the fixed-side mounting plate 7. The sprue bush 8 has a sprue 10 as a material passage inside, but penetrates through the fixed side mounting plate 7 and projects toward the fixed side template 6. Further, a locate ring 11 is fixed by a bolt 12 to the surface of the sprue bush 8 opposite to the movable die 2.

The fixed-side mold plate 6 is detachably fixed to the fixed-side mounting plate 7 by a bolt 16 as a fixing means, and a cavity block 17 as a fixed-side mold plate body, and an outer peripheral side of the cavity block 17. Positioning ring 19 positioned and fixed to the fixed side mounting plate 7 by bolts 18
It consists of

The positioning ring 19 is a movable die 2.
The inner peripheral surface of the side portion has a tapered surface 21 whose diameter increases toward the movable die 2 side. Further, a step portion 22 is formed on the outer peripheral portion of the cavity block 17 on the movable die 2 side, and an annular adjuster ring 23 is fitted in the step portion 22 and fixed by a bolt 24. ing. On the other hand, a substantially cylindrical inner peripheral stamper retainer 26 is fitted and fixed in the through hole 25 formed in the central portion of the cavity block 17. A stamper 27 for transferring stored information to an optical disc is detachably attached to the cavity block 17,
The inner peripheral stamper retainer 26 retains the inner peripheral portion of the stamper 27. The sprue bush 8 is fitted in a cylindrical inner peripheral stamper retainer 26. And
A concave portion 28 is formed on the tip surface of the sprue bush 8 on the movable die 2 side.

Further, in the cavity block 17,
A temperature control passage 31 is formed surrounding the product cavity 3 for passing a temperature control fluid such as cooling water. Also,
A temperature adjusting passage 32 communicating with the temperature adjusting passage 31 is formed in the fixed side mounting plate 7. Further, an O-ring 33 for preventing the temperature control fluid from leaking is mounted between the cavity block 17 and the fixed side mounting plate 7 so as to surround the temperature control passages 31, 32.

The movable mold 2 includes a movable side mold plate 41, a movable side receiving plate 42 fixed to a surface of the movable side mold plate 41 opposite to the fixed mold 1, and a movable side receiving plate 42 as a movable side mounting plate. A movable side mounting plate 44 fixed by a bolt 43 is provided on the surface of the side receiving plate 42 opposite to the fixed die 1. The movable side attachment plate 44 is attached to the movable plate (movable side platen) 107 of the mold clamping device of the toggle type injection molding machine. The movable side mold plate 41 includes a core block 46 as a movable side mold plate body fixed to the movable side receiving plate 42 by a bolt 45, and a movable side receiving plate 42 located on the outer peripheral side of the core block 46. It comprises a positioning ring 48 fixed by bolts 47. In addition, the positioning ring 48
Has a tapered surface 50 with which the tapered surface 21 of the positioning ring 19 on the fixed mold 1 side abuts when the mold is closed.

A step 51 is formed on the outer periphery of the fixed block 1 side of the core block 46.
An annular outer ring 52 is fitted in the step portion 51 so as to be slidable within a predetermined range in the mold opening / closing direction. In addition, 53
Are bolts for preventing the outer peripheral ring 52 from coming off. Also,
The outer peripheral ring 52 is urged toward the fixed mold 1 by a spring 55. The outer peripheral ring 52 abuts the adjuster ring 23 on the fixed mold 1 side when the mold is closed. A cavity forming portion 56 is formed on the inner peripheral portion of the outer peripheral ring 52 so as to closely face the stamper 27 and form the outer peripheral surface of the optical disc. A gap is formed between the cavity forming portion 56 and the cavity block 17 with the outer peripheral ring 52 abutting the adjuster ring 23. Further, a gap is formed between the inner peripheral surface of the outer peripheral ring 52 and the stepped portion 51 of the core block 46. These gaps act as gas vents when the resin is filled in the product cavity 3.

Further, a concave portion formed so as to penetrate the surface of the core block 46 on the side of the fixed mold 1 at the central axis Z which is the central portion.
An air blowing insert 62, which is a substantially annular movable insert, is fitted and fixed in 61. The core block is provided in the gap between the air blow-out insert 62 and the inner peripheral surface of the recess 61.
An air passage 64 formed in the movable plate 46 and the movable side receiving plate 42 communicates with each other. Then, a stepped portion 62A which is a locking receiving portion formed so that the tip has a small diameter is formed on the tip end side of the air blowing insert 62, that is, on the peripheral surface on the fixed die 1 side, while the tip end side of the recess 61 is formed. Is formed with a stepped portion 61A as a locking portion so that the fixed mold 1 side has a smaller diameter. The stepped portion 61A is locked to the stepped portion 62A, and the axial center Z side of the core block 46 is fixed. There is.

Then, a gap L is formed between the movable side receiving plate 42 and the core block 46. The gap L is a peripheral side 3B opposite to the axial center side 3A of the product cavity 3.
Is not formed in each of the parts corresponding to, and is formed between the axial side 3A and the peripheral side 3B.
Is formed so as to be gradually larger from a portion corresponding to the peripheral side 3B so that the maximum axial distance is the maximum, and the axial side 3A of the core block 46 faces the movable side receiving plate 42. The gap L is formed so as to recede from the one side 3B. That is, in the core block 46, an opposing surface with the flat cavity surface 46B as a reference
In the thicknesses A and B up to 46A, the thickness A of the axial center side 3A is formed smaller than the thickness B of the peripheral side 3B in advance (A <
B). This gap L corresponds to the difference in thickness in FIG.
That is, if the difference in thickness in FIG. 4 is 7 μm, the interval L may be set to about 7 μm, but as described later, considering the elastic deformation of the core block 46 due to the resin pressure, it is 1 with respect to the difference in thickness. -4 times, preferably 2-3 times (14-2
1 μm).

Further, a substantially cylindrical protruding sleeve 66 is fitted in the air blowing inlet 62 so as to be slidable within a predetermined range in the mold opening / closing direction. This protruding sleeve 66
Is a movable side receiving plate that penetrates the core block 46 and has one end side movable.
Although it is located inside 42, a slide bearing 67 is interposed between the movable side receiving plate 42 and the movable side receiving plate 42. Further, the protruding sleeve 66 is biased by the spring 68 toward the side opposite to the fixed mold 1. 69 is the protruding sleeve 66
Is a regulation plate fixed in the movable side receiving plate 42 for regulating the sliding range of the.

A substantially cylindrical gate cut sleeve 71 is fitted in the protruding sleeve 66 so as to be slidable within a predetermined range in the mold opening / closing direction. The gate cut sleeve 71 penetrates the protrusion sleeve 66 and the regulation plate 69, but a slide bearing 72 is interposed between the gate cut sleeve 71 and the protrusion sleeve 66. A flange portion 73 formed at one end of the gate cut sleeve 71 is located closer to the movable side mounting plate 44 than the regulation plate 69. Further, the gate cut sleeve 71 is biased by the spring 74 toward the side opposite to the fixed mold 1.

A projecting plate 76 is supported on the movable side mounting plate 44 so as to be slidable in a predetermined range in the mold opening / closing direction. The protruding plate 76 is urged by a spring 77 toward the side opposite to the fixed mold 1. And the protruding plate
A protruding pin 78 fixed to 76 is slidably fitted in the gate cut sleeve 71. Further, the interlocking pin 79 fixed to the protruding plate 76 penetrates the flange portion 73 of the gate cut sleeve 71 and the restriction plate 69 and abuts against the protruding sleeve 66. Further, a receiving portion 80 integrally provided on the flange portion 73 of the gate cut sleeve 71 slidably penetrates the protruding plate 76.

Further, in the core block 46, a temperature control passage 81 for passing a temperature control fluid such as cooling water is formed. Further, a temperature adjusting passage 82 communicating with the temperature adjusting passage 81 is formed in the movable side receiving plate 42. Furthermore, the temperature control passages 81, 82 are surrounded by a core block.
An O-ring 83 for preventing the temperature control fluid from leaking is attached between the movable support plate 42 and the movable support plate 42.

The sprue 10 on the fixed die 1 side is provided between the outer peripheral portion of the tip surface of the sprue bush 8 on the fixed die 1 side and the outer circumferential portion of the gate cut sleeve 71 on the movable die 2 side.
Is formed so as to communicate with the product cavity 3. Further, by fitting the gate cut sleeve 71 into the recess 28 of the sprue bush 8, the resin as the molding material in the sprue 10 and the resin in the product cavity 3, that is, the optical disc are cut at the gate 86, and the center of the optical disc is cut. The opening hole of the part is formed. Therefore, in the fixed mold 1, in addition to the cavity block 17, the optical disk is formed by the inner peripheral stamper retainer 26 and the outer peripheral portion of the tip end surface of the sprue bush 8. In addition, in the movable die 2, in addition to the core block 46 and the outer peripheral ring 52, the air blowing insert 62
The ejection sleeve 66 forms an optical disk.

Next, the molding of the optical disk will be described. At the time of this molding, first, the fixed mold 1 and the movable mold 2 are closed, and a product cavity 3 is formed between the fixed mold 1 and the movable mold 2. In the state where the mold is closed in this way, the outer peripheral ring 52 of the movable mold 2 has the adjuster ring 23 of the fixed mold 1.
In addition, the tapered surfaces 21 and 50 of the positioning rings 19 and 48 of the fixed die 1 and the movable die 2 are fitted to each other by taper. Then, the molten thermoplastic resin, which is a thermoplastic molding material, is injected from the nozzle of the injection molding machine into the sprue 10. This resin flows from the sprue 10 through the gate 86 into the product cavity 3. At this time, the space between the product cavities 3 on the axial center Z side of the product cavity 3 tends to widen due to the injected resin pressure, but in the vicinity of the axial center Z, the step portion 61A is locked to the step portion 62A, and the core Block Z axis Z
Since the side is fixed, it does not spread greatly,
On the peripheral side 3B, the core block 46 is pressed by the resin pressure.
Is pressed, and as a result, the axial center side 3 of the core block 46 is
Since the space between A and the peripheral side 3B retracts against the elastic force of the core block 46 and the facing surface 46A contacts the movable side mounting plate 42, the product cavity between the axial side 3A and the peripheral portion 3B side. The interval of 3 widens. Therefore, when the resin flows into the product cavity 3, the resin pressure causes the resin to be molded in a state where the space between the axial center side 3A and the peripheral portion 3B side of the product cavity 3 is widened, and the thickness as shown by the one-dot chain line in FIG. It is possible to mold a molded product having substantially the same shape on both the axial side 3A and the peripheral side 3B.

After that, the receiving portion 80 of the gate cut sleeve 71 is pushed toward the fixed mold 1 by a pressing rod (not shown) provided on the injection molding machine side, so that the gate cut sleeve 71 is fixed. It moves to the side and fits into the recess 28 of the sprue bush 8 of the fixed mold 1.
As a result, at the gate 86, the resin in the sprue 10 and the resin in the product cavity 3, that is, the optical disk, are cut off.

After the resin in the product cavity 3 is cooled and solidified, the fixed mold 1 and the movable mold 2 are opened.
With this mold opening, the molded optical disc and sprue
The resin solidified within 10 first separates from the fixed mold 1. Then, the push rod (not shown) provided on the injection molding machine side pushes the eject plate 7 toward the fixed mold 1, whereby the eject pin 78 moves to the fixed mold 1 side together with the eject plate 76, and the sprue 10 The resin solidified inside is ejected and released from the movable mold 2. Further, when pushed by the interlocking pin 79 fixed to the push-out plate 76, the push-out sleeve 66 moves to the fixed mold 1 side, and the inner peripheral portion of the optical disk is projected and released from the movable mold 2. Then, the released optical disc is taken out by a take-out robot (not shown). Then, the mold is closed again and the above molding cycle is repeated.

As described above, in the above embodiment, the movable die 2 and the fixed die 1 are provided, and the movable die 2 is the movable side receiving plate.
The core block 46 is provided at 42, the fixed mold 1 is provided with the cavity block 17 at the fixed side mounting plate 7, and the air blow-out insert 62 is provided at the axial center Z of the core block 46 as a stepped portion.
In a molding die device which is provided so as to be locked via 61A and 62A and forms a thin plate-shaped product cavity 3 between the core block 46 and the cavity block 17 when the mold is closed, the axis of the product cavity 3 The movable side receiving plate 42 and the core block 46 corresponding to between the side 3A and its peripheral side 3B.
By forming the gap L between the product cavity 3 and the resin, even if the resin flows into the product cavity 3 and the vicinity of the axis Z in the product cavity 3 tries to expand, it is blocked by the locking of the stepped portions 61A and 62A, and On the axial center side 3A of the outer product cavity, the core block 46 recedes to the gap L side due to the resin pressure, and the interval of the product cavity 3 at the location is widened, so that the axial center side 3A of the product cavity 3 becomes smaller. It is possible to form the molded article with the same thickness by forming the same interval on the peripheral side 3B.

Further, in the face 46A of the core block 46 facing the movable side receiving plate 42, the thickness of the face 46A of the product cavity 3 corresponding to between the axial side 3A and the peripheral side 3B thereof. By forming the gap L by making A smaller than the thickness B of the facing surface 46A corresponding to the peripheral side 3B, the core block 46 may be adjusted and manufactured in advance. This makes the facing surface
46A has a predetermined taper, that is, the product cavity 3 has the same displacement as the axial center side 3A of the product cavity 3 at the time of resin inflow.
It is sufficient to form a taper so that the peripheral side 3B in the above can be displaced, and it can be easily manufactured. Moreover, since the core block 46 is processed in advance on the facing surface 46A side, it is not necessary to process it on the cavity surface 46B side.

Further, even in the molding die device in which the fixed mold 1 is attached to the fixed plate of the mold clamping device of the toggle type injection molding machine and the movable mold 2 is attached to the movable plate, the axial center side of the product cavity 3 is provided. It is possible to eliminate the adverse effect at the time of molding of the molding die device attached to the toggle type injection molding machine that 3A is molded thickly.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the present invention. Although the movable side mounting plate and the movable side mold plate body are separately formed in the embodiment to form the movable mold, they may be integrated.

[0031]

According to the first aspect of the present invention, a movable die and a fixed die are provided. The movable die is provided with a movable die plate main body on a movable side attachment plate, and the movable die and the fixed die are closed when the die is closed. In a molding die device for forming a thin plate-shaped product cavity therebetween, a movable-side insert is provided by locking the movable-side mold plate main body to the axial center, and the axial center side of the product cavity and its peripheral side. A molding die device, characterized in that a gap is formed between the movable side mounting plate and the movable side template body corresponding to each other, wherein the movable side nest is locked to the movable side template plate body. The expansion of the space between the product cavities in the vicinity of the axis can be suppressed by further providing the movable side template plate body by retracting due to the gap, and the product cavity corresponding to the product cavity between the axis side and the peripheral side can be prevented. Wider spacing allows for accurate molding

According to a second aspect of the present invention, in the surface of the movable-side mold plate body facing the movable-side mounting plate, the facing surface of the product cavity corresponding to the axial center side and the peripheral side thereof is formed. The molding die apparatus according to claim 1, wherein the gap is formed by making a thickness smaller than a thickness of the facing surface corresponding to the peripheral side, and the molding die device according to claim 1, wherein the gap is formed by retreating in advance. , The movable mold plate body is retracted to widen the space between the axial center side and the peripheral side of the product cavity,
Can be accurately molded.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of the present invention.

FIG. 2 is an overall sectional view showing an embodiment of the present invention.

FIG. 3 is a partially cutaway front view showing a mold clamping device of a toggle type injection molding machine.

FIG. 4 is a graph showing the thickness of a molded product.

[Explanation of symbols]

1 fixed type 2 movable 3 product cavity 3A shaft center side 3B peripheral side 42 Movable side receiving plate (movable side mounting plate) 46 core block (movable-side template body) 61A step (locking part) 62A step (lock receiving part) L gap

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F202 AG19 AH38 AH79 CA11 CB01                       CK42 CK90                 5D121 DD05 DD18

Claims (2)

[Claims] 1. A movable die and a fixed die are provided, wherein the movable die has a movable side attachment plate provided with a movable side die plate body, and
In a molding die device for forming a thin plate-shaped product cavity between the movable mold and the fixed mold when the mold is closed, the movable side insert is locked to the axial center of the movable side mold plate main body, A molding die device, characterized in that a gap is formed between the movable side mounting plate and the movable side mold plate body which correspond between the axial center side of the cavity and the peripheral side thereof. 2. In the surface of the movable-side template body facing the movable-side mounting plate, the thickness of the opposing surface corresponding to the axial center side of the product cavity and the peripheral side thereof is set to the peripheral area. The molding die apparatus according to claim 1, wherein the gap is formed by making the gap smaller than the thickness of the facing surface corresponding to the side.