JP2003245960A - Mold assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a molding cycle by effectively cooling a sprue. <P>SOLUTION: A pipe 92 is folded back to form an outward passage 93 and a return passage 94 in parallel and a folded back part 95 is positioned on the side of the gate 86 of a sprue bush 8 to spirally wind the pipe 92 from the gate 86 toward the opposite side of the gate 86. Accordingly, cooling water supplied to a temperature regulation passage 91 spirally advances not only toward the gate 86 through the outward passage 93 of the pipe 92 but also toward the opposite side of the gate 86 from the folded back part 95 through the return passage 94 to uniformly and rapidly cool the resin in the sprue 10 as a whole. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die apparatus. In a molding die apparatus used for injection molding of an optical disk or the like, a fixed mold provided with a sprue bush and a movable mold provided opposite to the fixed mold are closed. Then, a product cavity is formed between the fixed mold and the movable mold, and a molten thermoplastic resin as a molding material injected from a nozzle of the injection molding machine is filled in the product cavity, and the resin in the product cavity is solidified. After that, the fixed mold and the movable mold are opened to take out the molded optical disk or the like. In the fixed type and the movable type, a temperature control passage through which cooling water passes is provided for cooling and solidifying a molten thermoplastic resin filled in a product cavity or a sprue. [0003] Japanese Unexamined Patent Application Publication No. Hei 1 (1994) -107, discloses a fixed type in which a temperature control passage is provided along the sprue to cool and solidify the molten thermoplastic resin filled in the sprue.
This is known as a mold apparatus disclosed in Japanese Patent No. 159221. Since this mold device has a cylindrical cooling path formed almost all around the sprue, there is a problem that it is difficult to flow cooling water and to effectively cool the resin in the gate. An object of the present invention is to solve such a problem, and an object of the present invention is to provide a molding die apparatus capable of effectively cooling a sprue and increasing a molding cycle. According to a first aspect of the present invention, there is provided a fixed type provided with a sprue bush and a movable type provided opposed to the fixed type. In the molding die apparatus provided with a temperature control passage in the sprue bush, the temperature control passage is formed by turning a pipe to form a forward path and a return path that are parallel to each other, and the folded part is positioned on a gate side of the sprue bush. The pipe is spirally wound from the gate side of the sprue bush toward the opposite side of the gate. According to the structure of the first aspect, the temperature adjusting fluid spirals on the outward path of the pipe toward the gate side so as to surround the sprue, and passes through the return path of the pipe via the turn-back portion. The sprue is cooled effectively by spiraling around the sprue towards the opposite side of the sprue. An embodiment of the molding apparatus according to the present invention will be described below with reference to FIGS. 1
Is a fixed mold, and 2 is a movable mold. The fixed mold 1 and the movable mold 2, which are molds, move in the vertical direction in the figure (the mold opening and closing direction) to open and close. To form. The fixed mold 1 includes a fixed mold plate 6 and a fixed mounting plate 7 fixed to a surface of the fixed mold plate 6 opposite to the movable mold 2 (upper surface in the drawing). I have.
The fixed side mounting plate 7 is mounted on a fixed side platen of an injection molding machine (not shown). A sprue bush 8 to which a nozzle of an injection molding machine is connected is fixed to a central portion of the fixed-side mounting plate 7 by a bolt 9. The inside of the sprue bush 8 is a sprue 10 which is a material passage, but penetrates through the fixed side mounting plate 7 and protrudes toward the fixed side mold plate 6 side. Further, a locate ring 11 is fixed to a surface of the sprue bush 8 on the side opposite to the movable mold 2 by bolts 12. The fixed-side mold plate 6 includes a cavity block 17 as a cavity forming member fixed to the fixed-side mounting plate 7 by bolts 16 so as to be detachable, and a fixed side located on the outer peripheral side of the cavity block 17. Mounting plate 7
And a positioning ring 19 fixed by bolts 18. The cavity block 17 forms the product cavity 3. In addition, the positioning ring 19
Has a tapered surface 21 whose inner diameter increases toward the movable mold 2 on the inner peripheral surface of the movable mold 2 side. further,
A step 22 is formed on the outer periphery of the cavity block 17 on the movable mold 2 side.
Is fitted with an annular outer stamper retainer 23
Fixed by 24. On the other hand, a substantially cylindrical inner peripheral stamper retainer 26 is fitted and fixed in a through hole 25 formed in the center of the cavity block 17. A stamper 27 for transferring stored information to an optical disk is detachably mounted on the cavity block 17, but the outer stamper holder 23 is provided with a stamper.
Hold the outer periphery of 27, and press the inner stamper holder 26 with the stamper
It holds down the inner circumference of 27. The sprue bush 8 is fitted in a cylindrical inner peripheral stamper retainer 26. A concave portion 28 is formed in the end surface of the sprue bush 8 on the movable mold 2 side. In the cavity block 17,
A temperature control passage 31 is formed around the product cavity 3 for passing a temperature control fluid such as cooling water. Also,
A temperature control passage 32 communicating with the temperature control passage 31 is formed in the fixed-side mounting plate 7. Further, an O-ring 33 is mounted between the cavity block 17 and the fixed-side mounting plate 7 so as to surround the temperature control passages 31 and 32 to prevent leakage of the temperature control fluid. The movable mold 2 includes a movable mold plate 41, a movable receiving plate 42 fixed to a surface (a lower surface in the drawing) of the movable mold plate 41 opposite to the fixed mold 1. Movable support plate
A movable side mounting plate 44 fixed by bolts 43 is provided on the surface of the side opposite to the fixed mold 1 in 42. The movable mounting plate 44 is mounted on a movable platen of an injection molding machine. The movable side mold plate 41 includes a core block 46 as a cavity forming member fixed to the movable side receiving plate 42 by bolts 45, and a bolt 47 attached to the movable side receiving plate 42 located on the outer peripheral side of the core block 46. And a positioning ring 48 fixed by the The core block 46 forms the product cavity 3. The positioning ring 48 has a tapered surface 50 with which the tapered surface 21 of the positioning ring 19 on the fixed die 1 abuts when the mold is closed. A step 51 is formed on the outer periphery of the portion of the core block 46 on the fixed mold 1 side.
An annular outer ring 52 is fitted to the step portion 51 so as to be slidable in a predetermined range in the mold opening and closing direction. Note that 53
Are bolts for retaining the outer ring 52. Also,
The outer peripheral ring 52 is urged toward the fixed die 1 by a spring 55. The outer peripheral ring 52 abuts against the outer peripheral stamper holder 23 on the fixed mold 1 side when the mold is closed. In addition, a cavity forming portion 56 that forms the outer peripheral surface of the optical disk is formed in the inner peripheral portion of the outer peripheral ring 52 in close proximity to the stamper 27. Note that a gap is formed between the cavity forming portion 56 and the cavity block 17 in a state where the outer peripheral ring 52 abuts the outer peripheral stamper retainer 23. Further, a gap is also formed between the inner peripheral surface of the outer peripheral ring 52 and the step portion 51 of the core block 46. These gaps act as gas vents when filling the product cavity 3 with resin. A substantially annular air blowing / inserting member 62 is fitted into a concave portion 61 formed on the surface of the core block 46 at the center of the fixed mold 1 and fixed by bolts 63. . In the gap between the air blowing insert 62 and the inner peripheral surface of the concave portion 61, the core block 46 and the movable side receiving plate 42 are provided.
An air passage 64 formed therein communicates. A substantially cylindrical protruding sleeve 66 is slidably fitted in the air blowing insert 62 in a predetermined range in the mold opening and closing direction. This overhanging sleeve 66
Is a movable side receiving plate that passes through the core block 46 and has one end side.
The 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 urged by a spring 68 to the side opposite to the fixed mold 1. 69 is a protruding sleeve 66
Is a restricting plate fixed within the movable-side receiving plate 42 for restricting the sliding range. A substantially cylindrical gate cut sleeve 71 is slidably fitted within the protruding sleeve 66 in a predetermined range in the mold opening and closing direction. The gate cut sleeve 71 penetrates the protrusion sleeve 66 and the restriction plate 69, and a slide bearing 72 is interposed between the gate cut sleeve 71 and the protrusion sleeve 66. A flange 73 formed at one end of the gate cut sleeve 71 is located closer to the movable mounting plate 44 than the regulating plate 69 is. Further, the gate cut sleeve 71 is urged by a spring 74 to the side opposite to the fixed mold 1. A projecting plate 76 is slidably supported by the movable side mounting plate 44 in a predetermined range in the mold opening and closing direction. The projecting plate 76 is urged by a spring 77 to 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, an interlocking pin 79 fixed to the protruding plate 76 penetrates through the flange portion 73 of the gate cut sleeve 71 and the regulating plate 69 and abuts on the protruding sleeve 66. Further, a receiving portion 80 protruding from the flange portion 73 of the gate cut sleeve 71 penetrates the protruding plate 76 slidably. Further, a temperature control passage 81 for passing a temperature control fluid such as cooling water is formed in the core block 46. A temperature control passage 82 communicating with the temperature control passage 81 is formed in the movable receiving plate 42. In addition, core blocks around the temperature control passages 81 and 82
An O-ring 83 is mounted between the movable side receiving plate 42 and the movable side receiving plate 42 to prevent leakage of the temperature adjusting fluid. The sprue 10 on the fixed die 1 side is located between the outer peripheral portion of the distal end surface of the sprue bush 8 on the fixed die 1 side and the outer peripheral portion of the tip end surface of the gate cut sleeve 71 on the movable die 2 side.
Is formed to communicate with the product cavity 3. When the gate cut sleeve 71 is fitted into the concave portion 28 of the sprue bush 8, the resin as the molding material in the sprue 10 and the resin in the product cavity 3, ie, the optical disk, are cut at the gate 86, and the center of the optical disk is cut off. The opening of the portion is formed. Therefore, in the fixed mold 1, an optical disk is formed by the inner peripheral stamper retainer 26 and the outer peripheral portion of the distal end surface of the sprue bush 8 in addition to the cavity block 17. Further, in the movable mold 2, in addition to the core block 46 and the outer peripheral ring 52, an air
The optical disk is formed by the protruding sleeve 66 and the protrusion sleeve 66. The sprue bush 8 is provided with a temperature control passage 91. The temperature control passage 91 includes:
Folding a pipe 92 made of metal or the like and going in parallel 93
And the return path 94, and the sprue bush 8
The sprue bush 8 is formed by spirally winding the pipe 92 from the gate 86 side of the sprue bush 8 toward the opposite side of the gate 86. A supply path 96 provided in the fixed-side mounting plate 7 communicates with an outward path 93 of the pipe 92,
A discharge path 97 provided in the fixed-side mounting plate 7 communicates with the return path 94 of 92. The sprue bush 8
Is composed of a head 98 and a bush body 99 having the sprue 10 on the center axis thereof.
Are spirally wound. Means for communicating the forward path 93 and the supply path 96 of the pipe 92 and the return path 94 and the discharge path 97 of the pipe 92 can be appropriately selected.For example, by dividing the fixed-side mounting plate 7 into upper and lower parts, The supply path 96 and the discharge path 97 can be assembled with one pipe 92 while being integrally formed. Further, the fixed side mounting plate 7 may be formed with a groove for incorporating a pipe forming the supply path 96 and the discharge path 97. Next, molding of the optical disk will be described. During 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 this state, the outer peripheral ring 52 of the movable mold 2 is fixed to the outer periphery
23, and the tapered surfaces 21 and 50 of the positioning rings 19 and 48 of the fixed mold 1 and the movable mold 2 are taperedly fitted to each other. Then, sprue 10 from the nozzle of the injection molding machine
Inject molten thermoplastic resin, which is a thermoplastic molding material. This resin flows from the sprue 10 through the gate 86 into the product cavity 3. After the product cavity 3 has been filled with resin, 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. As a result, the gate cut sleeve 71 moves toward the fixed die 1 and fits into the recess 28 of the sprue bush 8 of the fixed die 1. This allows gate 86
At this time, the resin in the sprue 10 and the resin in the product cavity 3, ie, the optical disk, are cut. The sprue 10 and the product cavity 3
The resin inside is positively cooled by cooling water, which is a temperature adjusting fluid supplied from the supply path 96, being discharged from the discharge path 97 through the temperature control path 91. In this case, the cooling water supplied from the supply path 96 to the temperature control
Along the outward path 93 of the pipe 92 toward the gate 86 side spirally so as to surround the sprue 10, and through the return path 94 of the pipe 92 through the folded portion 95, surround the sprue 10 toward the opposite side of the gate 86. The resin in the sprue 10 is cooled uniformly and quickly as a whole because the resin is discharged from the discharge path 97 by spirally moving. 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 in 10 first leaves the fixed mold 1. Then, when the ejection plate 7 is pushed toward the fixed mold 1 by a pressing rod (not shown) provided on the injection molding machine side, the ejection pin 78 moves together with the ejection plate 76 toward the fixed mold 1 and the sprue 10 is moved. The resin solidified inside is protruded and released from the movable mold 2. The pushing sleeve 66 is pushed by the interlocking pin 79 fixed to the pushing plate 76, so that the pushing sleeve 66 moves to the fixed mold 1 side, and projects the inner peripheral portion of the optical disk to be released from the movable mold 2. Then, 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. As described above, in the present embodiment, the temperature control passage 91 is formed by folding one pipe 92 to form a forward path 93 and a return path 94 which run in parallel, Position the folded part 95 at
Since the pipe 92 is formed by spirally winding the pipe 92 from the gate 86 side of the sprue bush 8 toward the opposite side of the gate 86, the cooling water supplied from the supply path 96 to the temperature control path 91 Of the sprue 10 toward the gate 86 toward the gate 86 side, and a turn 95
Through the return path 94 of the pipe 92 toward the opposite side of the gate 86 spirally to surround the sprue 10 and the discharge path
By discharging from the 97, the resin in the sprue 10 is cooled uniformly and quickly as a whole. Therefore, the molding cycle can be increased. Further, as an effect on the embodiment, since the pipe 92 forming the outward path 93 and the pipe 92 forming the return path 94 come into contact with each other, the cooling water in the return path 94 is cooled by the cooling water in the outward path 93, so that cooling is performed. The effect is enhanced. Further, since the temperature control passage 91 is constituted by a pipe, the processing is easy and the watertightness is good. It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
Although the molded article has been described by taking an optical disk as an example, it can be applied to other various molded articles. According to the first aspect of the present invention, the fluid for temperature adjustment spirals on the outward path of the pipe toward the gate side so as to surround the sprue, and returns to the pipe via the turn-back portion. The sprue is effectively cooled by spiraling through and around the sprue toward the opposite side of the gate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 2 is a sectional view of a main part showing an embodiment of the present invention. FIG. 3 is a perspective view of a temperature control passage showing an embodiment of the present invention. FIG. 4 is a schematic explanatory view showing an embodiment of the present invention. [Description of Signs] 1 Fixed mold 2 Movable mold 3 Product cavity 8 Sprue bush 10 Sprue 86 Gate 91 Temperature control forward path 92 Pipe 93 forward path 94 return path 95 Folded part

Claims (1)

1. A molding die apparatus comprising: a fixed mold provided with a sprue bush; and a movable mold provided opposite to the fixed mold, wherein a temperature control passage is provided in the sprue bush. The temperature control passage is formed by turning a pipe to form a forward path and a return path that are parallel to each other, and the return part is located on the gate side of the sprue bush, and from the gate side of the sprue bush toward the opposite side of the gate. A molding die apparatus formed by spirally winding the pipe.