WO2002051608A1

WO2002051608A1 - Metal mold device for forming optical disk

Info

Publication number: WO2002051608A1
Application number: PCT/JP2001/011362
Authority: WO
Inventors: Toshihiro Chihara; Yoshihiro Horikawa
Original assignee: Mitsubishi Materials Corporation
Priority date: 2000-12-25
Filing date: 2001-12-25
Publication date: 2002-07-04
Also published as: KR20030060117A; CN1491150A; TW537959B; JP2002192587A

Abstract

A metal mold device for forming an optical disk capable of uniformizing a metal mold temperature around a product cavity so that the dimensional accuracy of an optical disk can be increased, comprising a cavity block and a core block installed opposedly to the cavity block, wherein the product cavity is formed between the cavity block and the core block, a temperature adjusting flow passage allowing coolant to flow therein is provided in the cavity block and the core block, and a distance from the surface of the product cavity to a communication passage part of the product cavity is increased in the communication passage par for lowering the cooling capacity for each unit area the temperature adjusting flow passage, whereby the cooling capacity can be lowered by increasing a heat conductive distance to optimally adjust the surface temperature of the product cavity.

Description

Description Optical Disc Molding Device Background of the Invention

1. Field of application of the invention

The present invention relates to a mold device for molding an optical disk such as a CD (compact disk) and a DVD (digital video disk).

2. Description of the prior art

In an optical disk, its substrate is generally injection-molded with resin. In this molding, the fixed mold and the movable mold respectively attached to the fixed plate and the movable plate of the injection molding machine are closed to form a product cavity between the fixed mold and the movable mold, and the product is injected from the nozzle of the injection molding machine. The molten thermoplastic resin, which is the molding material, is filled into the product cavity, and the resin in the product cavity, that is, the optical disk is solidified in a mold adjusted to a predetermined low temperature, that is, the fixed mold and the movable mold. Open and take out the molded optical disk. In addition, the mold is provided with a temperature control flow path through which a cooling liquid is passed, in order to keep the product capacity in the mold at a predetermined low temperature.

By the way, high dimensional accuracy is required in optical disk molding, but as mentioned above, during molding, molten resin is injected into product cavities, filled at high speed, and adjusted to a predetermined low temperature by a coolant. Since the mold is cooled and solidified by the mold, the thickness may not be able to be accurately maintained due to shrinkage of the resin during the cooling. This is because the temperature control channel and the surface of the product cavity are all formed at the same distance in the conventional mold device, and the temperature control on the surface of the product cavity may be insufficient. This is due to uneven temperature distribution on the surface of the product cavity. In such a mold device, the cooling capacity per unit area of the product cavity is higher than the average, for example, in places where the temperature control flow path is dense, so it is necessary to lower the cooling capacity per unit area of the product cavity. There is. On the other hand, in locations where the temperature control flow path is sparse, the cooling capacity per unit area of the product cavity is lower than the average, so cooling per unit area of the product cavity You need to increase your ability. There is a need for improved temperature control in such locations where the mold temperature is not uniform.

The present invention is intended to solve such a problem, and it is possible to optimize a mold temperature around a product cavity, and as a result, to improve an optical disc's dimensional accuracy and the like. An object is to provide a molding die apparatus. Summary of the Invention

The present invention has a mold having a fixed mold and a movable mold provided to face the fixed mold, and a product cavity is formed between the fixed mold and the movable mold. In a mold device for molding optical discs with a temperature control flow path through which heat flows, the distance from the surface of the product cavity to the temperature control flow path should be reduced at locations where the cooling capacity per unit area of the product cavity by the temperature control flow path is reduced. It is characterized in that the distance from the surface of the product capital to the temperature control channel is shortened where it is longer or where the cooling capacity per unit area of the product cavity by the temperature control channel is increased.

This configuration optimizes the temperature distribution of the product cavity by adjusting the cooling capacity of the location where the cooling capacity per unit area of the product cavity is increased or decreased by the temperature control flow path, and the dimensional accuracy of the optical disc Etc. can be improved.

Here, preferably, the temperature control flow path is formed in a groove shape, and the distance is a distance between the bottom surface of the groove-shaped temperature control flow path and the surface of the product cavity.

According to this configuration, the mold is cooled by flowing the coolant through the groove-shaped temperature control flow path. In addition, since the temperature control channel is groove-shaped, the distance can be easily and accurately set.

• More preferably, a plurality of temperature control flow paths are formed so as to be concentric with the product cavity, and a communication path connecting the temperature control flow path part located inside and the temperature control flow path part located outside is formed. In the passage section, the distance is increased.

According to this configuration, the distance from the surface of the product cavity to the temperature control flow path is long in the communication path portion where the cooling capacity per unit area is to be reduced. As a result, the adverse effect caused by excessive cooling in the communication path can be solved. More preferably, the distance is shortened on the outer peripheral side of the product cavity.

According to this configuration, the distance from the surface of the product cavity to the temperature control flow path becomes shorter on the outer peripheral side of the product capital, which is a place where a large amount of heat is radiated. As a result, the temperature distribution in the product cavity with a large heat dissipation can be set uniformly. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of a mold device for molding an optical disc, showing a first embodiment of the present invention.

FIG. 2 is a plan view of a main part of the optical disk molding die apparatus shown in FIG.

FIG. 3 is a cross-sectional view of the optical disk molding die apparatus shown in FIG.

FIG. 4 is a sectional view of a mold device for molding an optical disk, showing a second embodiment of the present invention.

FIG. 5 is a plan view of a main part of the optical disk molding die device shown in FIG. Preferred embodiment

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 3 show a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a fixed type, 2 denotes a movable type, and a mold body. The fixed type 1 and the movable type 2 (Opening / closing direction) to open and close, and when the mold is closed, two product cavities 3 forming an optical disc are formed between each other.

The fixed mold 1 includes a fixed-side mold plate 4 as a base, and a fixed-side receiving plate 5 fixed to a surface of the fixed-side mold plate 4 opposite to the movable mold 2 (upper surface in the drawing) and acting as a base. And Further, cold sprue bushes 6 corresponding to the product cavities 3 are fixed to the fixed-side receiving plate 5. The head 7 of the cold sprue bush 6 fits into a recess 8 formed in the fixed-side receiving plate 5 and has a cylindrical projection 9 on the fixed-side mold plate 4 side. The part 9 extends from the stationary receiving plate 5 to the stationary template 4 further. Also, cold spruce bush 6 The head 7 is provided with a material supply nozzle 10. Further, a cold sprue 112 is formed in the cold sprue bush 6, which is a material passage from the bottom surface of the head 7 to which the raw material supply nozzle 10 is connected to the tip end surface of the protrusion 9. The cold sprue 12 has a tapered shape whose diameter increases toward the product cavity 3, and communicates with the product cavity 3. Reference numeral 13 denotes a recess formed in the head 7 and into which the raw material supply nozzle 10 is inserted.

The fixed mold plate 4 includes a positioning frame 14 fixed to the surface of the fixed mold plate 2 on the movable mold 2 side, and a cap that is fitted inside the positioning frame 14 and serves as a capty forming member. It is composed of a Viti block 15. The cavity block 15 forms the product capacities 3, and an annular outer stamper retainer 16 is detachably attached to the outer periphery of the cavity block 15, and the inner periphery of the cavity block 15 is formed. A cylindrical inner stamper retainer 17 is detachably attached to the portion. These stamper retainers 16 and Π are used to detachably hold the stampers forming the optical disk group and land on the cavity block 15. An intermediate cylinder 18 is fitted into the inner stamper retainer 17 penetrating the cavity block 15, and the projecting portion 9 of the cold sprue bush 6 is fitted into the intermediate cylinder 18. I agree. The inner peripheral stamper retainer 17 and the intermediate cylinder 18 form a part of the product cavity 3. Further, a temperature control passage 19 through which coolant such as water (temperature control fluid) passes is formed in the cavity block 15. The movable die 2 includes a movable mounting plate 20 mounted on a fixed platen of the injection molding machine, a movable receiving plate 21 fixed to a surface of the movable mounting plate 20 on the fixed die 1 side, and a movable receiving plate 21. A movable mold plate 22 fixed to the surface of the plate 21 on the fixed mold 1 side. The movable-side mold plate 22 includes a positioning frame 23 fixed to the surface of the movable-side receiving plate 21 on the fixed mold 1 side, and a core block 24 fitted inside the positioning frame 23 and acting as a cavity forming member. It is composed of The core blocks 24 form the above-mentioned product cavities 3, respectively, and the positioning frame 23 is tapered into the positioning frame of the fixed mold 1. In the core block 24, a temperature control passage 25 for passing the cooling liquid is formed.

An abutment ring 26 is fitted around the outer periphery of the core block 24. This thrust The contact ring 26 abuts the outer stamper holder 16 on the fixed mold 1 side when the mold is closed, and forms the outer peripheral surface of the product cavity 3.

Further, a cylindrical air outlet / inlet 27 is fixed to the inner peripheral portion of the core block 24 in a penetrating state, and a cylindrical protruding sleeve 28 is provided on the inner peripheral side of the air outlet / inlet 27. It is slidably fitted within a predetermined range along the opening and closing direction of the mold. A cylindrical gate cut sleeve 29 is slidably fitted to the inner peripheral side of the protruding sleeve 28 within a predetermined range along the opening / closing direction of the mold, and inside the gate cut sleeve 29, The protruding pin 30 is slidably fitted in a predetermined range along the opening and closing direction of the mold. The protruding sleeve 28 and the gate cut sleeve 29 are respectively urged to the opposite sides of the fixed mold 1.

The gate cut sleeve 29 has a receiving portion 31 protruding from the movable-side mounting plate 20. When the receiving portion 31 is pressed by a pressing rod (not shown) provided in the injection molding machine, the gate cut sleeve 29 moves to the fixed mold 1 side. The protruding pin 30 is fixed to a protruding plate 32 provided in the movable-side mounting plate 20. When the ejection plate 32 is pushed by another pushing rod '(not shown) provided in the injection molding machine, the ejection pin 30 moves to the fixed mold 1 side. Further, an interlocking pin (not shown) fixed to the protruding plate 32 pushes the protruding sleeve 28, so that the protruding sleeve 28 moves to the fixed mold 1 side.

The gate cut sleeve 29 is removably fitted in the intermediate cylinder 18 of the fixed mold 1 to form an opening located at the center of the optical disc. Therefore, the protruding sleeve 28 and the air blowing insert 27 located on the outer peripheral side of the gate cut sleeve 29 form a part of the product capital 3. Also, between the outer peripheral portion of the distal end surface of the protrusion 9 provided on the cold sprue bush 6 on the fixed die 1 side and the outer peripheral portion of the distal end surface of the gate cut sleeve 29 on the movable die 2 side, A gate 34 is formed to allow the cold sprue 1 1 2 to communicate with the product cavity 3.

The temperature control passages 19A, 19B have first to third temperature control passages 19A and 19B, each of which has a substantially C-shaped plane centered on the center axis X of the product cavity 3 and gradually increases in diameter. , 19 C are provided concentrically. At the beginning of the first temperature control passage 19 A, Through a temperature control fluid supply passage (not shown), a supply inlet 36 for a coolant W as a temperature control fluid is provided, and at the end thereof, it is located outside toward the side opposite to the center axis X. A first communication path portion 19D communicating with the start end of the second temperature control passage portion 19B is provided. Further, at the end of the second temperature control passage portion 19B, a second communication passage portion communicating with the start end of the third temperature control passage portion 19C located outside toward the side opposite to the center axis X is provided. In addition to the outlet 19E, an outlet 37 for discharging the coolant W is provided at the end of the third temperature control passage 19C. The discharge outlet 37 is connected to a temperature control fluid discharge passage (not shown). The first to third temperature control passage portions 19A, 19B, 19C and the first and second communication passage portions 19C, 19E are formed in a groove shape from a surface opposite to the product cavity 3 by a cutting device 35 such as a ball end. It is formed.

In the first to third temperature control passages 19A, 19B, and 19C, where the cooling capacity per unit area of the product cavity 3 in the cavity block 15 is an average, the surface 3A of the product cavity is The distance A, which is the depth to the bottom of the temperature control passages 19A, 19B, and 19C, is the same. On the other hand, in the first communication passage 19D, where the cooling capacity per unit area of the product cavity 3 by the temperature control flow path 19 needs to be reduced, the surface 3A of the product cavity and the first connection The distance B to the bottom of the passage 19D is longer than the distance A. Note that, of the first temperature control passage portion {9}, the distance Β is longer than the distance において also at a portion located near the first communication passage portion 19D. Similarly, it is necessary to lower the cooling capacity per unit area of the product capacities 3 by the temperature control flow passages 19, between the product cavity surface 3A and the bottom surface of the second communication passage 19E. The distance B is also longer than the distance A, and the distance B is longer than the distance A also in a portion of the second temperature control passage portion 19B that is located near the second communication passage portion 19E. The adjustment of the distances A and B is performed during machining by the cutting device 35. That is, the temperature control passage 19 corresponding to the distance B is

The range indicated by arrows L and L 'in 2 and 3 is obtained.

Similarly, in the core block 24, the temperature control passage 25 has a substantially C-shaped flat surface from the inside to the outside with the center axis X of the product cavity 3 as the center.

1-3 temperature control passages 25A, 25B, 25C are provided concentrically. At the beginning of the first temperature control passage 25A, an inlet 38 for supplying the coolant W is provided, and at the end, A first communication passage portion 25D is provided, which is opposite to the center axis X and communicates with the start end of the second temperature control passage portion 25B. Further, a second communication passage 25E is provided at the end of the second temperature control passage portion 25B toward the side opposite to the central axis X and communicates with the start end of the third temperature control passage 25C. At the end of the third temperature control passage 25C, an outlet 39 for discharging the coolant W is provided. The distance A ′, which is the depth between the surface 3B of the product cavity in the core block 24 and the bottom surface of the first to third temperature control passages 25A, 25B, 25C, is Both are the same. On the other hand, the distance B ′ between the surface 3B of the product cavity and the bottom surface of the first communication passage 25D is longer than the distance A. The distance B ′ is longer than the distance A ′ even in a portion of the first temperature control passage portion 25A that is located near the first communication passage portion 25D. Similarly, the distance B ′ between the surface 3B of the product cavity and the tip of the second communication passage 25E is longer than the distance A ′, and the second temperature control passage 25B has the second distance B ′. The distance B ′ is longer than the distance A ′ even at a position that is located near the communication passage 25E.

Next, a method of molding an optical disk using the mold apparatus will be described. At the time of molding, first, the fixed mold 1 and the movable mold 2 are closed, and two product cavities 3 are formed between the fixed mold 1 and the movable mold 2. With the mold closed, the abutment ring 26 of the movable die 2 abuts the outer stamper retainer 16 of the fixed die 1 and the positioning frames 14 of the fixed die 1 and the movable die 2 23 are tapered into each other. Then, a molten thermoplastic resin, which is a thermoplastic molding material, is injected from an injection molding machine. The resin flows from the nozzle 10 through the cold sprue 12 sequentially, and flows into the product cavity 3 from the gate 34.

After the resin is filled into the product cavity 3, the receiving part 31 of the gate cut sleeve 29 is pushed toward the fixed mold 1 by a pressing rod (not shown) provided on the injection molding machine side. The sleeve 29 moves to the fixed mold 1 side and fits in the intermediate cylinder 18 of the fixed mold 1. Thereby, at the gate 34, the resin in the cold sprue 12 and the resin in the product cavity 3, that is, the optical disk are cut.

In addition, the resin in the product cavity 3 is cooled by the coolant supplied from the supply inlets 36 and 38 passing through the temperature control passages 19 and 25. At this time, the temperature control passage 19 is dense and the cooling capacity per unit area of the product cavity 3 is reduced. In the vicinity of the required first and second communication passages 19D and 19E, the distance B between the surface 3A of the product cavity and the tip of the second communication passage 19E is longer than the distance A. As a result, the heat conduction distance becomes longer, and as a result, the cooling capacity at the surface 3 A of the product cavity is reduced accordingly, and the cooling capacity becomes almost the same as other parts. Similarly, the temperature control passage 25 is dense, and the cooling capacity per unit area of the product cavity 3 needs to be reduced. In the vicinity of the first and second communication passages 25D and 25E, the product cavity is located. The distance B 'between the surface 3B of the product and the front end of the second communication path 25E is longer than the distance A'. The cooling capacity is reduced, and the cooling capacity is almost the same as other places.

After the resin in the product cavity 3 has cooled and solidified, the fixed mold 1 and the movable mold 2 are opened. Accordingly, the resin solidified in the molded optical disk and the cold sprue 12 first separates from the fixed mold 1. Next, the ejecting plate 32 is pushed toward the fixed mold 1 by the pushing port (not shown) provided on the injection molding machine side, so that the ejecting pin 30 moves together with the ejecting plate 32 to the fixed mold 1 side. Then, the resin solidified in the cold sprue 12 is protruded and released from the movable mold 2. Further, in conjunction with the protrusion plate 32, the protrusion sleeve 28 moves to the fixed mold 1 side, protrudes the inner peripheral portion of the optical disc, and is released from the movable mold 2. The released optical disk is taken out by a take-out robot (not shown). Thereafter, the mold is closed again and the above molding cycle is repeated.

According to the configuration of the present embodiment, the product block 3 is provided between the cavity block 15 and the core block 24 with the cavity block 15 and the cavity block 24 provided facing the cavity block 15. In the optical disk molding apparatus provided with the temperature control flow paths 19 and 25 through which the cooling liquid W flows through the cavity block 15 and the core block 24, the cooling per unit area of the product cavity 3 by the temperature control flow paths 19 and 25 is performed. In the communication passages 19D, 19E, 25D, and 25E, where the capacity needs to be reduced, the building passages 19D, 19E, 25D, and 25D, from the surface 3A and 3B of the product cavity. By increasing the distances B and B 'up to 25E, the heat conduction distance is lengthened and the cooling capacity is reduced. As a result, the temperature on the surfaces 3A and 3B of the product cavity can be made uniform. Further, the temperature control channels 19, 25 are formed by grooves, and the distances A, B, A ', B' are defined by the bottom surfaces of the groove-shaped temperature control channels 19, 25 and the surfaces 3A, 3B of the product cavities. The distances A, B, A ′, and B ′ can be easily set by the cutting device 35 from the surface on the opposite side of the product cavity 3.

A plurality of temperature control channels 19 and 25 are formed concentrically with the product cavity 3, and the inner temperature control channels 19A, 19B, 25A and 25B and the outer temperature control channels 19B and 19C. , 25B, 25C, the product cavity surface 3A in the communication passage portions 19D, 19E, 25D, 25E by increasing the distances B, B 'in the communication passage portions 19D, 19E, 25D, 25E. , 3B lowers the cooling effect, raises the temperature, makes the surface temperature uniform, and can mold a precise optical disc.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The groove-shaped temperature control flow path 41 provided in the cap 15 has a semicircular shape formed on one surface of the cavity block 15 so as to be concentric with the product cavity 3. The first to third temperature control channels 41A, 41B, and 41C are provided. On the other hand, the other side of the cavity block 15 is provided with semicircular fourth to sixth temperature control channels 41D, 41E, 41F formed concentrically with the product cavity 3. I have it. A cooling liquid supply inlet 42 is connected to the beginning of the first temperature control flow path 41A, and the end of the first temperature control flow path 41A and the second temperature control flow path 41B. Start end, end of second temperature control flow path 41B, start end of third temperature control flow path 41C, end of third temperature control flow path 41C, and fourth temperature control flow path Start end of 41D, end of fourth temperature control channel 41D, start of fifth temperature control channel 41E, start of fifth temperature control channel 41E end of temperature control, and sixth temperature control channel The communication passages 43 are connected to the start end of 41F. In addition, a coolant outlet 44 is connected to the end of the sixth temperature control flow path 41F.

The outermost third temperature control channel portion 41C and the sixth temperature control channel portion 41F are provided so as to face the outer periphery of the product cavity 3, and The distance C between the bottom surface of the groove forming the flow paths 41C and 41F and the product cavity surface 3A is the other temperature control flow paths 41A, 41B, 41D and 41E. Form The distance between the bottom of the groove and the surface 3A of the product cavity is shorter than D.

Similarly, also in the core block 24, the temperature control flow path 45 is formed by the first to sixth temperature control flow paths 45A, 45B, 45C, 45D, 45E, and 45F. The third outermost temperature control channel portion 45C and the sixth outermost temperature control channel portion 45F are provided so as to face the outer periphery of the product capital 3. The distance E between the tip of the groove forming the flow passages 45C and 45F of No. 6 and the product cavity surface 3B is the same as that of the other temperature control flow passages 45A, 45B, 45D and 45E of the other first, second, fourth and fifth. The distance between the end of the groove and the product cavity surface 3B is shorter than F.

In the second embodiment, the resin in the product cavity 3 filled in the product cavity 3 is cooled by the coolant passing through the temperature control passages 41 and 45. At this time, generally, the heat radiation amount is large on the outer peripheral side of the product cavity 3, and it is necessary to increase the cooling capacity by the coolant. On the other hand, the distances C and E to the product cavity surfaces 3 A and 3 B at the outermost third and sixth temperature control flow passages 41 C, 41 F, 45 C and 45 F are different from other temperature control flow passages. The roads 41A, 41B, 41D, 41E, 45A, 45B, 45D, and 45E are formed shorter than the distances D and F at the roads.

According to the second embodiment, the distance from the surface of the product capital 3 to the temperature control flow path becomes shorter on the outer peripheral side of the product capital 3. As a result, the heat transfer distance of the coolant on the outer peripheral side of the product cavity 3 is shortened, so that the cooling capacity on the outer peripheral side of the product cavity 3 with a large amount of heat dissipation is relatively increased, and the temperature distribution of the product cavity 3 is reduced. It can be set uniformly.

Note that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

Claims

The scope of the claims

1-a mold having a fixed mold and a movable mold provided opposite to the fixed mold, forming a product cavity between the fixed mold and the movable mold, and adding a coolant to the mold. In a mold apparatus for molding an optical disk provided with a temperature-adjusting flow path for flowing, a distance from the surface of the product cavity to the temperature-adjusting flow path at a location where the cooling capacity per unit area of the product cavity by the temperature-adjusting flow path is reduced. The mold apparatus for molding an optical disk, wherein the distance from the surface of the product capital to the temperature control channel is shortened at a portion where the cooling capacity per unit area of the product cavity is increased by the temperature control channel.

2. The optical disc molding metal according to claim 1, wherein the temperature control flow path is formed in a groove shape, and the distance is a distance between a bottom surface of the groove temperature control flow path and a surface of the product capty. Mold device.

3. A plurality of the temperature control flow paths are formed concentrically with the product cavity, and a communication path section that connects the temperature control flow path section located inside and the temperature control flow path section positioned outside is provided. 2. The optical disc molding die according to claim 1, wherein the distance is increased.

4. A plurality of the temperature control flow paths are formed concentrically with the product cavity, and a communication path section that connects the temperature control flow path section located inside and the temperature control flow path section located outside is provided. 3. The optical disc molding die according to claim 2, wherein the distance is increased.

5. The optical disk molding die apparatus according to claim 1, wherein the distance on the outer peripheral side of the product cavity is shortened.

6. The optical disk molding die apparatus according to claim 2, wherein the distance on the outer peripheral side of the product cavity is shortened.

7. The optical disk molding die apparatus according to claim 3, wherein the distance on the outer peripheral side of the product cavity is shortened.

8. The optical disk molding die apparatus according to claim 4, wherein the distance on the outer peripheral side of the product cavity is shortened.