JP2915775B2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a resin heated and melted in a heating cylinder is filled in a cavity of a mold, and cooled in the cavity.
After solidification, the mold is opened and the molded product is taken out. When molding a precise molded product such as a lens, a CD, or a disk base such as an optical disk, an injection compression device is provided on a movable platen of an injection molding machine, and the cavity is filled by operating the injection compression device. The resin pressure is forcibly increased at a predetermined timing to spread the resin all over the cavity and to compensate for the shrinkage of the resin during the cooling step.

[0003] One-piece injection molding is performed, and one molded article is formed in one injection molding cycle. FIG. 2 is a sectional view of a conventional injection compression device.
In the drawing, reference numeral 11 denotes a fixed platen, 12 denotes a fixed type attached to the fixed platen 11, 13 denotes a movable platen disposed to face the fixed platen 11, and 14 denotes a compression block fixed to the movable platen 13. Reference numerals 15 and 15 denote injection compression pistons which are disposed in an injection compression cylinder chamber 16 formed in the compression block 14 so as to be able to move forward and backward.

The injection compression piston 15 has a large diameter portion 15a,
The injection compression cylinder chamber 16 has a middle diameter portion 15b and a small diameter portion 15c, and has a shape corresponding to the injection compression piston 15 so that the injection compression piston 15 can move forward and backward. An oil chamber 17 is formed in the injection compression cylinder chamber 16 behind the large-diameter portion 15a of the injection compression piston 15 (to the left in the drawing). You can move forward (moving to the right in the figure).

[0005] A compression core 21 is disposed in front of the injection compression piston 15 (to the right in the figure) so as to be freely contactable therewith.
To move forward (moving rightward in the figure). Then, a cavity 23 is formed between the compression core 21 and the fixed mold 12. Further, a compression core support block 25 is fixed to the compression block 14, and
It is arranged so that it can come and go freely. The compressed core support block 2
Reference numeral 5 designates a moving stroke of the movable platen 13, and when the movable platen 13 is advanced (moved rightward in the drawing) during the mold closing step, the fixed mold 12 comes into contact with the compression core support block 25. As a result, the movable platen 13 Is stopped. The movable core 30 is constituted by the compression core 21 and the compression core support block 25.

[0006] Even after the fixed mold 12 comes into contact with the compressed core support block 25, the compressed core 21 can be advanced by supplying oil to the oil chamber 17. An injection device 27 fills the cavity 23 with the resin melted by the heating cylinder, a sprue bush 28, an ejector rod 29, and an ejector plate and an ejector pin (not shown) are provided on the ejector rod 29. Is established. The ejector pin is disposed with the tip thereof facing the cavity 23 through the compression core 21 so that the molded product can be pushed down when the ejector pin advances.

In the injection molding machine having the above structure, when a predetermined time has elapsed after the completion of the mold clamping step, oil is supplied to the oil chamber 17 and the injection compression piston 15 is advanced. Then, when the injection compression piston 15 comes into contact with the compression core 21, thereafter, the compression core 21 is pressed and advanced to press the resin in the cavity 23. Therefore, a compression allowance a is formed between the contact portion between the compression core 21 and the fixed mold 12 before moving forward.

[0008]

However, in the above-described conventional injection molding machine, injection molding is performed by taking one piece, and one molded article is molded in one injection molding cycle. Therefore, injection molding by multi-cavity cannot be performed. The present invention is to solve the problems of the conventional injection molding machine and to provide an injection molding machine which can perform injection molding by single-piece molding and can also perform injection molding by multi-piece molding. Aim.

[0009]

To this end, an injection molding machine according to the present invention has a fixed platen and a movable platen opposed to the fixed platen and capable of moving forward and backward. A fixed mold is attached to the fixed platen, and a movable mold is attached to the movable platen.

The movable die has an integral compression block detachably mounted on the movable platen, and a plurality of compression blocks disposed opposite to the fixed die to form a cavity between the fixed die and the fixed die. And a compression core. Each of the compression cores has a punching die, and the fixed die has a receiving die corresponding to each of the punching dies.

The compression block includes a plurality of injection compression cylinder chambers, and an injection compression piston arranged to be able to move forward and backward in the injection compression cylinder chamber. An ejector pin arranged with the cut punch piston to be advanced and the tip facing each cavity penetrates. In another injection molding machine of the present invention, there is provided a control servo valve for independently controlling the supply of oil to the oil chambers of the respective injection compression cylinder chambers.

[0012] In still another injection molding machine of the present invention,
The movable platen includes one injection compression cylinder chamber, and an injection compression piston disposed to be able to move forward and backward in the injection compression cylinder chamber. In still another injection molding machine according to the present invention, the compression block includes a cut punch cylinder chamber corresponding to each punching die, and the cut punch piston is disposed in the cut punch cylinder chamber so as to be able to advance and retreat.

[0013] In still another injection molding machine of the present invention,
The compression block includes an ejector cylinder chamber corresponding to each ejector pin, and the ejector piston is disposed in the ejector cylinder chamber so as to be able to advance and retreat.

[0014]

According to the present invention, as described above, in an injection molding machine, a fixed platen,
And a movable platen arranged to be movable forward and backward.
A fixed mold is attached to the fixed platen, and a movable mold is attached to the movable platen.

In this case, the mold can be closed, clamped and opened by moving the movable platen forward and backward. The movable die has a compression block of an integral structure detachably mounted on the movable platen, and a plurality of compression cores disposed opposite to the fixed die to form a cavity between the fixed die and the fixed die. Consisting of

Each of the compression cores has a punching die, and the fixed die has a receiving die corresponding to each of the punching dies. Further, the compression block includes a plurality of injection compression cylinder chambers, and an injection compression piston disposed so as to be able to advance and retreat in the injection compression cylinder chamber, and the injection compression piston is cut to advance the punching die when moving forward. Ejector pins arranged with the punch piston and the tip facing each cavity penetrate.

In this case, the compression core can be advanced by supplying oil to the oil chamber of the injection compression cylinder chamber. The compression block is removed from the movable platen when performing injection molding by single-piece molding, and the compression block is attached to the movable platen when performing injection molding by multiple-piece molding. In another injection molding machine of the present invention, there is provided a control servo valve for independently controlling the supply of oil to the oil chambers of the respective injection compression cylinder chambers. In this case, the timing for advancing the compression core can be set independently for each cavity.

In still another injection molding machine of the present invention,
The movable platen includes one injection compression cylinder chamber, and an injection compression piston disposed to be able to move forward and backward in the injection compression cylinder chamber. Therefore, when performing injection molding by taking one piece, the compression core is advanced by advancing the injection compression piston. In still another injection molding machine according to the present invention, the compression block includes a cut punch cylinder chamber corresponding to each punching die, and the cut punch piston is disposed in the cut punch cylinder chamber so as to be able to advance and retreat.

In this case, the punching die can be advanced by supplying oil to the oil chamber of the cut punch cylinder chamber. In still another injection molding machine of the present invention,
The compression block includes an ejector cylinder chamber corresponding to each ejector pin, and the ejector piston is disposed in the ejector cylinder chamber so as to be able to advance and retreat.

In this case, the ejector pin can be advanced by supplying oil to the oil chamber of the ejector cylinder chamber.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a front view of the injection molding machine in the embodiment of the present invention, FIG. 4 is a plan view of the injection molding machine in the embodiment of the present invention, and FIG. 5 is a side view of the injection molding machine in the embodiment of the present invention. In this embodiment, an injection molding machine for molding a disk substrate as a molded product will be described.

As shown in the figure, a fixed platen 35 is fixed to a base 36, and a toggle support 38 is disposed on the base 36 at a predetermined distance from the fixed platen 35. The fixed platen 35 and the toggle support 38 are 4
They are connected by four tie bars 40 arranged at the corners. Further, a movable platen 43 is disposed to face the fixed platen 35 and to be able to move forward and backward along the tie bar 40. The fixed platen 35 is provided with a fixed type (not shown),
A movable mold comprising a compression core 4 and a compression core (not shown) is attached, and by moving the movable platen 43 forward and backward, the fixed mold and the movable mold are brought into contact with and separated from each other, and the mold can be closed, clamped and opened.

In order to move the movable platen 43 forward and backward, a toggle mechanism 45 is provided between the movable platen 43 and the toggle support 38. The toggle mechanism 45 is extended and contracted by a drive device (not shown) such as a hydraulic cylinder and an electric motor. The compression block 44 has an injection compression cylinder chamber (not shown), and an injection compression piston is disposed in the injection compression cylinder chamber so as to be able to advance and retreat. The compression core is provided in front of the injection compression piston, and a cavity (not shown) is formed between the compression core and the fixed die.

In this embodiment, injection molding can be performed by taking four pieces, and the compression block 44 has four injection compression cylinder chambers. Accordingly, four control servo valves 52 are disposed on the side of the compression block 44 via the oil supply block 51 so that the oil can be independently supplied to the oil chambers of the respective injection compression cylinder chambers. Is done. In this case, the control servo valve 52
Thus, the supply of oil to the oil chamber of each injection compression cylinder chamber can be controlled.

When a disk base is formed, a through hole is formed at the center of the disk base. for that reason,
A punching die (not shown) is provided on the compression core such that the tip thereof faces the cavity so as to be able to advance and retreat. On the other hand, a receiving die (not shown) corresponding to the punching die is provided in the fixed die. A cut punch cylinder chamber (not shown) is provided in the compression block 44, and a cut punch piston is provided in the cut punch cylinder chamber so as to be able to advance and retreat. The punching die can be advanced by advancing the cut punch piston, and the through hole can be punched. In addition, four cut punch piston control valves 50 are provided on the movable platen 43 so that oil can be independently supplied to the oil chamber of the cut punch cylinder chamber. in this case,
The supply of oil to the oil chamber of each cut punch cylinder chamber can be controlled by the cut punch piston control valve 50.

Next, the injection compression device will be described. FIG. 1 is a partial sectional view of an injection compression apparatus according to an embodiment of the present invention, FIG. 6 is a side view of the injection compression apparatus according to an embodiment of the present invention, and FIG. 7 is a front view of the injection compression apparatus according to the embodiment of the present invention. . As shown in the figure, a compression block 44 is disposed in front of the movable platen 43 (below in FIG. 1).
A control servo valve 52 is disposed on the side of the compression block 44 via an oil supply block 51.

The compression block 44 includes a movable platen 4
3, a cut punch piston accommodating member 56 fixed to the front (lower in FIG. 1) end surface of the spacer 55, and a front (see FIG. 1) of the cut punch piston accommodating member 56. An injection compression piston accommodating member 57 fixed to the lower end surface.

The spacer 55 has a concave portion opened rearward (upward in FIG. 1), and the ejector plate accommodating chamber 60 is formed by closing the concave portion with the movable platen 43. An ejector plate 62 is disposed in the ejector plate housing chamber 60 so as to be able to move forward and backward. The ejector plate 62 has four recesses 63 that open forward (downward in FIG. 1) at four locations. By embedding a pressing member 64 in the recesses 63, the ejector pins 66
Is to be fixed.

To this end, a flange 67 is formed at the rear (upper in FIG. 1) end of the ejector pin 66, and the pressing member 64 presses the flange 67 against the ejector plate 62. The holding member 64
Is fixed to the ejector plate 62 by bolts 68. Further, in front of the ejector pin 66 (below in FIG. 1), another ejector pin disposed in a compression core (not shown) is disposed.
An ejector cylinder chamber (not shown) is formed in the movable platen 43 behind (upper in FIG. 1). An ejector piston is disposed in the ejector cylinder chamber, and the ejector piston is supplied by supplying oil to an oil chamber formed behind the ejector piston.
And an ejector rod (not shown) connected to the ejector piston is advanced. Then, as the ejector rod advances, the ejector plate 6
2. The disk base (not shown) can be pushed down by the advance of the ejector pin 66 and the other ejector pins in the compression core.

The ejector plate 62 is supported by support pillars 70 disposed at four places of the spacer 55 and is guided and reciprocates. As shown in FIG. 6, the support pillar 70 is provided with each ejector pin 6.
It is arranged between six. A flange 72 is formed at the front (lower in FIG. 1) end of the support pillar 70, and the support pillar 70 is fixed by pressing the flange 72 against the cut punch piston receiving member 56 by the spacer 55. You.

The ejector plate 62 is provided with return springs 73 disposed at four places of the spacer 55.
1 and is always in contact with the movable platen 43. The return spring 73 extends forward (downward in FIG. 1) through the ejector plate 62, and has a forward end fixed to the cut punch piston receiving member 56.
Supported and guided by

The cut punch piston accommodating member 56 has concave portions opened rearward (upward in FIG. 1) at four positions corresponding to the ejector pins 66. The concave portions are closed by spacers 55. By doing so, a cut punch cylinder chamber 76 is formed. A cut punch piston 78 is provided in the cut punch cylinder chamber 76.
Are arranged to be able to advance and retreat.

The cut punch piston 78 has a sleeve shape surrounding the ejector pin 66, and a large diameter portion is disposed in the cut punch cylinder chamber 76 as a piston body and extends rearward (upward in FIG. 1). The small diameter portion penetrates the spacer 55 and the end face faces the ejector plate housing chamber 60, and the end face of the small diameter portion extending forward (downward in FIG. 1) passes through the cut punch piston housing member 56 and the injection compression piston 92 and is compressed. It faces the core, and is disposed in the compression core so as to be able to freely contact and separate from a punching die (not shown).

The cut punch piston 78 is
A first oil chamber 84 is formed in the cut punch cylinder chamber 76 behind the large diameter portion (upper in FIG. 1), and a second oil chamber 85 is formed in front of the large diameter portion (lower in FIG. 1). Therefore, by supplying oil to the first oil chamber 84 via the oil passage 88, the cut punch piston 78 and the punching die can be advanced (moved downward in FIG. 1), and the through hole of the disk base can be punched. Further, by supplying oil to the second oil chamber 85 via the oil passage 89, the cut punch piston 78 and the punching die can be moved backward (moved upward in FIG. 1).

Further, the injection compression piston accommodating member 5
Numeral 7 has concave portions opened rearward (upward in FIG. 1) at four positions corresponding to the ejector pins 66, and the cut-compression-piston accommodating member 56 closes the concave portions so that the injection compression cylinder chamber is closed. 91 are formed. An injection compression piston 92 is provided in the injection compression cylinder chamber 91 so as to be able to advance and retreat.

The injection compression piston 92 has a sleeve shape surrounding a small diameter portion in front of the cut punch piston 78 (downward in FIG. 1), and the large diameter portion is disposed in the injection compression cylinder chamber 91 as a piston body. The end face of the small-diameter portion extending forward (downward in FIG. 1) penetrates the injection compression piston accommodating member 57 and is disposed so as to be able to freely contact and separate from the compression core.

The injection compression piston 92 is located behind the large diameter portion in the injection compression cylinder chamber 91 (FIG. 1).
A first oil chamber 94 is formed above (in FIG. 1), and a second oil chamber 95 is formed in front of the large diameter portion (below in FIG. 1). Accordingly, by supplying oil to the first oil chamber 94 via the oil passage 96, the compression core is advanced, the pressure of the resin in the cavity (not shown) is increased, and the accuracy of the disk base is increased to improve the signal transferability. And the base characteristics such as birefringence can be improved. Further, by supplying oil to the second oil chamber 95 via the oil passage 97, the compression core can be retracted.

As shown in FIG. 7, the movable platen 43 has an injection compression cylinder chamber 80 for performing single-piece injection molding.
An injection compression piston 81 is arranged to be able to move forward and backward. An oil chamber 82 is formed behind the injection compression piston 81 (to the left in FIG. 7). The oil is supplied to the oil chamber 82 to move the injection compression piston 81 forward (to the right in FIG. 7). ).

Reference numeral 40 denotes a tie bar, and reference numeral 99 denotes a pressure sensor for controlling the compression force of the injection compression piston 92. In the injection compression device having the above configuration, the toggle mechanism 45
Is operated to move the movable platen 43 forward (moving downward in FIG. 1) to close and close the mold. Subsequently, after injecting a resin from an injection nozzle (not shown) and filling the cavity, oil is supplied to the first oil chamber 84 through an oil passage 88 to advance the cut punch piston 78 and the punching die, and the disc is moved forward. Punch through through holes in base.

Thereafter, oil is supplied to the first oil chamber 94 via the oil passage 96 to advance the compression core, and increase the pressure of the resin in the cavity. Next, toggle mechanism 4
5, the movable platen 43 is retracted (moved upward in FIG. 1), the mold is opened, and then the ejector piston and ejector rod are advanced. Then, as the ejector rod advances, the ejector plate 62, the ejector pin 66, and another ejector pin disposed in the compression core advance, and push down the disk base.

When performing injection molding by taking one piece, the compression block 44 is removed from the movable platen 43, and the pressure of the resin in the cavity is increased by moving the injection compression piston 81 forward. When performing injection molding by multi-cavity molding, the compression block 44 is attached to the movable platen 43, and the pressure of the resin in the cavity is increased by moving the injection compression piston 92 forward (moving downward in FIG. 1). . In this manner, by attaching and detaching the compression block 44, it is possible to perform injection molding by taking one piece, and also to perform injection molding by taking many pieces. In this case, as the compression block 44 is removed from the movable platen 43, the cut punch piston control valve 50 (FIG. 5) is also removed from the movable platen 43.

Even if a mold clamping device (not shown) having no cut punch function and no injection compression function necessary for molding the disk base is used, the cut punch function or the like can be achieved simply by attaching the compression block 44 to the movable platen 43. An injection compression function can be provided. The first oil chamber 94 and the second oil chamber 94 of each injection compression cylinder chamber 91
The supply of oil to the oil chamber 95 can be controlled independently by the control servo valve 52. Further, the cut punch piston 7 is concentric with the injection compression piston 92.
The supply of oil to the first oil chamber 84 and the second oil chamber 85 of each cut punch cylinder chamber 76 can be independently controlled by the cut punch piston control valve 50. Therefore, the timing of injection compression and punching of the through hole of the disk base can be set independently for each cavity, so that in multi-cavity injection molding, the same molding conditions as in single-cavity injection molding are obtained. It is possible to do.

In this embodiment, the ejector cylinder chamber and the ejector piston are disposed in the movable platen 43, and the ejector plate 62 is moved forward by moving the ejector piston forward. May be disposed in the compression block 44. In this case, the supply of oil to the oil chamber of each ejector cylinder chamber can be controlled independently. Therefore, the timing of protrusion by the ejector pins 66 can be set independently for each cavity.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0045]

As described above in detail, according to the present invention, in an injection molding machine, a fixed platen and a movable platen which is disposed opposite to the fixed platen and is capable of moving forward and backward are provided. Have. A fixed mold is attached to the fixed platen, and a movable mold is attached to the movable platen.

The movable die has an integral compression block detachably mounted on the movable platen, and a plurality of compression blocks disposed opposite to the fixed die to form a cavity between the fixed die and the fixed die. And a compression core. Each of the compression cores has a punching die, and the fixed die has a receiving die corresponding to each of the punching dies.

Further, the compression block includes a plurality of injection compression cylinder chambers and an injection compression piston arranged to be able to move forward and backward in the injection compression cylinder chamber, and the injection compression piston is connected to the punching die when moving forward. An ejector pin arranged with the cut punch piston to be advanced and the tip facing each cavity penetrates. Therefore,
By removing the compression block from the movable platen, one-piece injection molding can be performed,
By attaching the compression block to the movable platen, injection molding by multi-cavity can be performed.

Another injection molding machine of the present invention has a control servo valve for controlling the supply of oil to the oil chambers of the respective injection compression cylinder chambers independently. In this case, the timing for advancing the compression core can be set independently for each cavity. Accordingly, it is possible to determine the same molding conditions as in the injection molding by one-piece molding in the injection molding by multi-piece molding.

In still another injection molding machine of the present invention,
The movable platen includes one injection compression cylinder chamber, and an injection compression piston disposed to be able to move forward and backward in the injection compression cylinder chamber. In the case of performing single injection molding, the compression core is advanced by advancing the injection compression piston. Therefore, a single compression block is not required.

In still another injection molding machine of the present invention,
The compression block has a cut punch cylinder chamber corresponding to each punching die, and the cut punch piston is provided in the cut punch cylinder chamber so as to be able to move forward and backward. In this case, the punching die can be advanced by supplying oil to the oil chamber of the cut punch cylinder chamber, and the through hole can be punched in the molded product.

In still another injection molding machine of the present invention,
The compression block includes an ejector cylinder chamber corresponding to each ejector pin, and the ejector piston is disposed in the ejector cylinder chamber so as to be able to advance and retreat.
In this case, by supplying oil to the oil chamber of the ejector cylinder chamber, the ejector pin can be advanced, and the molded product can be pushed down from the compression core.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an injection compression device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional injection compression device.

FIG. 3 is a front view of the injection molding machine according to the embodiment of the present invention.

FIG. 4 is a plan view of the injection molding machine according to the embodiment of the present invention.

FIG. 5 is a side view of the injection molding machine according to the embodiment of the present invention.

FIG. 6 is a side view of the injection compression device according to the embodiment of the present invention.

FIG. 7 is a front view of the injection compression device according to the embodiment of the present invention.

[Explanation of symbols]

 35 Fixed platen 43 Movable platen 44 Compression block 52 Servo valve for control 66 Ejector pin 76 Cut punch cylinder chamber 78 Cut punch piston 80, 91 Injection compression cylinder chamber 81, 92 Injection compression piston

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Yamaya 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (56) References JP-A-6-304981 (JP, A) JP-A-Hei 5-329897 (JP, A) JP-A-5-305625 (JP, A) JP-A-5-154885 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/56 B29C 45/26 B29C 45/03-45/13 B29C 45/40 B29C 45/64-45/70 B29C 45/82

Claims (5)

(57) [Claims] 1. A fixed platen, (b) a movable platen opposed to the fixed platen and movable back and forth, and (c) a fixed mold attached to the fixed platen. (D) a movable die attached to the movable platen, and (e) the movable die is opposed to the fixed die, which is an integrally configured compression block detachably mounted on the movable platen. And a plurality of compressed cores that form a cavity between the fixed mold and the fixed mold,
(F) each compression core includes a punching die; (g) the stationary mold includes a receiving die corresponding to each of the punching dies;
(H) The compression block includes a plurality of injection compression cylinder chambers, and an injection compression piston arranged to be able to move forward and backward in the injection compression cylinder chamber, and causes the punching die to advance when the injection compression piston advances. An injection molding machine characterized in that an ejector pin disposed with a cut punch piston and a tip facing each cavity penetrates. 2. The injection molding machine according to claim 1, further comprising a control servo valve for independently controlling oil supply to an oil chamber of each of the injection compression cylinder chambers. 3. The injection molding machine according to claim 1, wherein the movable platen includes one injection compression cylinder chamber, and an injection compression piston arranged to be able to move forward and backward in the injection compression cylinder chamber. 4. The apparatus according to claim 1, wherein (a) the compression block includes a cut punch cylinder chamber corresponding to each punching die, and (b) the cut punch piston is disposed in the cut punch cylinder chamber so as to be able to advance and retreat. The injection molding machine as described. (5) The compression block includes an ejector cylinder chamber corresponding to each ejector pin, and (b)
2. The injection molding machine according to claim 1, wherein the ejector piston is provided to be able to advance and retreat in the ejector cylinder chamber.