JP3343370B2 - Injection compression device - 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 compression device.

[0002]

2. Description of the Related Art Conventionally, a resin heated and fluidized in a heating cylinder is filled into a mold at a high pressure and cooled therein.
In an injection molding machine which solidifies and then opens a mold to take out a molded product, a screw is disposed in a heating cylinder so as to be rotatable and advanceable and retractable. The resin accumulated in front of the screw inside is injected from an injection nozzle and is filled in a cavity of a mold.

[0003] In molding precision products such as lenses and CDs, an injection compression device is provided.
The pressure of the resin filled in the cavity of the mold is forcibly increased at a predetermined timing to spread the resin all over the cavity and to supply the insufficient resin due to shrinkage during the cooling process. . 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-side mounting plate attached to the fixed platen 11, 1
Reference numeral 3 denotes a fixed mold attached to the fixed-side attachment plate 12;
Reference numeral 4 denotes a movable platen provided to face the fixed platen 11, reference numeral 15 denotes an injection compression block fixed to the movable platen 14, reference numeral 16 denotes a cylinder chamber formed in the injection compression block 15, and reference numeral 17 denotes a cylinder chamber. An injection compression piston slidably disposed inside the piston 16.

The injection compression piston 17 has a large diameter portion 17a,
The cylinder chamber 16 has a middle diameter portion 17b and a small diameter portion 17c, and has a shape such that the injection compression piston 17 can slide back and forth. Reference numeral 19 denotes an oil chamber formed behind the large-diameter portion 17a of the injection compression piston 17 (to the left in the figure). An oil path (not shown) is connected to the oil chamber 19, and oil is supplied through the oil path. By supplying oil to the chamber 19, the injection compression piston 17 can be moved forward (to the right in the figure).

Reference numeral 21 denotes a movable mounting plate attached to the injection compression block 15, 22 denotes a spacer block attached to the movable mounting plate 21, 23 denotes a receiving plate, and 24 denotes a movable plate attached to the receiving plate 23. It is a mold. 26 is an ejector plate. The ejector plate 26 includes:
Each of the injection compression piston 17 and the ejector rod 27 is disposed so as to be in contact with the front end face thereof, and when oil is supplied to the oil chamber 19, the ejector pin driving device 28 When activated, it is pushed via the ejector rod 27 and moves forward. An ejector pin 31, a sprue lock pin 32 and a compression core 33 protrude from the front end face of the ejector plate 26, and a cavity 35 is formed between the compression core 33 and the fixed mold 13.

[0007] The numeral 37 denotes the molten resin,
Injection device for filling the inside, 38 is a sprue bush, 3
9 is a return pin. In the above-described injection compression apparatus, after the mold clamping step is completed, the cavity 35 is filled with a resin, and then the injection compression block 15 is cooled in a cooling step of cooling to a temperature at which a molded product can be taken out.
Oil is supplied to the oil chamber 19 in the inside,
Moves forward, and the compression core 3 moves through the ejector plate 26.
3 is moved forward by pressing, and the resin filled in the cavity 35 is pressed.

In this manner, the resin is compressed by an amount corresponding to the amount of shrinkage of the resin in the cooling step, thereby improving the surface accuracy of the molded product.

[0009]

However, in the conventional injection compression apparatus, since the resin is compressed only from one side, uniform compression is not performed when the molded article is thick. That is, although the pressure is likely to increase in the portion of the resin near the compression surface, the pressure is difficult to be transmitted as the distance from the compression surface increases, and the pressure gradient becomes large. Therefore, compressive strain occurs, and the dimensional accuracy and surface accuracy of the molded product cannot be sufficiently improved.

The present invention solves the above-mentioned problems of the conventional injection compression apparatus, and sufficiently improves the dimensional accuracy and surface accuracy of a molded product without generating compression distortion even when the molded product is thick. It is an object of the present invention to provide an injection compression device that can be operated.

[0011]

For this purpose, in the injection compression apparatus of the present invention, a stationary platen, a first injection compression block attached to the stationary platen, and a stationary platen attached to the first injection compression block. A mold and the first
A first injection compression piston slidably disposed in the injection compression block, means for moving the first injection compression piston, and a first compression core that moves with the movement of the first injection compression piston. A movable platen, a second injection compression block attached to the movable platen, a movable mold attached to the second injection compression block and contacting and separating from the fixed mold to form a cavity; An ejector plate movably disposed between the injection compression block and the movable mold, and a second ejector plate slidably disposed in the second injection compression block and slidably contacting the ejector plate. (2) an injection compression piston, means for moving the second injection compression piston, and attached to the ejector plate to move with the movement of the second injection compression piston. And has a second compressed core approaching and moving away from said first compressed core and an ejector rod disposed freely in contact with the ejector plate.

[0012]

[0013]

According to the present invention, as described above, in the injection compression apparatus, the fixed platen, the first injection compression block attached to the fixed platen, and the fixed mold attached to the first injection compression block. A first injection / compression piston slidably disposed in the first injection / compression block; a means for moving the first injection / compression piston; and moving with the movement of the first injection / compression piston. A first compression core, a movable platen, a second injection compression block attached to the movable platen, and a movable mold attached to the second injection compression block and forming a cavity in contact with and separated from the fixed mold. And an ejector plate movably disposed between the second injection compression block and the movable mold, and slidably in the second injection compression block, and A second injection compression piston disposed so as to be in contact with the ejector plate, a means for moving the second injection compression piston, and a second attachment compression piston attached to the ejector plate and moving with the movement of the second injection compression piston. A second compression core that comes into contact with and separates from the first compression core; and an ejector rod that is disposed so as to be in contact with the ejector plate.

[0014]

In this case, the movable platen is moved,
After the fixed mold and the movable mold are brought into contact with each other to perform mold clamping, the cavity is filled with resin. Subsequently, when the molded article is cooled in the cooling step, the resin contracts. At this time, the first and second injection compression pistons are moved,
The first and second compression cores move toward the center.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an injection compression device showing an embodiment of the present invention. In the figure, reference numeral 11 denotes a fixed platen, 51 denotes a first injection compression block fixed to the fixed platen 11, 52 denotes a cylinder chamber formed in the first injection compression block 51, and 53 slides in the cylinder chamber 52. It is a 1st injection compression piston freely arrange | positioned.

Numeral 54 denotes an oil chamber formed in front (to the right in the figure) of the first injection compression piston 53. An oil path (not shown) is connected to the oil chamber 54, and oil is supplied through the oil path. Room 54
The first injection compression piston 53
Can be moved backward (to the left in the figure). Reference numeral 12 denotes a fixed-side mounting plate mounted on the first injection compression block 51, 55 denotes a spacer block mounted on the fixed-side mounting plate 12, and 13 denotes a fixed mold mounted on the spacer block 55.

Reference numeral 57 denotes a first ejector plate. The first ejector plate 57 is connected to a rod 58 extending rearward from the first injection compression piston 53, and is pressed via the first injection compression piston 53 when oil is supplied to the oil chamber 54, and is moved rearward. Moving. A first compression core 61 is provided on the rear end face of the first ejector plate 57 so as to be movable relative to the fixed mold 13.

On the other hand, reference numeral 14 denotes a movable platen provided to face the fixed platen 11, and 65 denotes a movable platen 1
A second injection compression block 66 fixed to 4 is a cylinder chamber formed in the second injection compression block 65, and 67 is a second injection compression piston slidably disposed in the cylinder chamber 66. . The second injection compression piston 67 has a large diameter part 67a, a medium diameter part 67b, and a small diameter part 67c,
The cylinder chamber 66 has a shape such that the second injection compression piston 67 can slide back and forth.

Reference numeral 69 denotes an oil chamber formed behind (to the left of) the large diameter portion 67a of the second injection compression piston 67. An oil passage (not shown) is connected to the oil chamber 69, By supplying the oil to the oil chamber 69 via the passage, the second injection compression piston 67 can be moved forward (to the right in the drawing). Reference numeral 21 denotes a movable mounting plate attached to the second injection compression block 65, 22 denotes a spacer block attached to the movable mounting plate 21, 23 denotes a receiving plate, and 24 denotes a movable metal attached to the receiving plate 23. Type.

Reference numeral 72 denotes a second ejector plate. The second ejector plate 72 is disposed so as to be freely contactable with the respective front end faces of the second injection compression piston 67 and the ejector rod 27, and when the oil is supplied to the oil chamber 69, the second injection compression piston 67. Through and also
When the ejector pin driving device 28 operates, the ejector pin driving device 28 is pressed via the ejector rod 27 and moves forward. The front end face of the second ejector plate 72 includes
The ejector pin 31, the sprue lock pin 32, and the second compression core 73 are arranged to protrude. The second compression core 73
Is disposed so as to be relatively movable with respect to the movable mold 24, between the fixed mold 13 and the movable mold 24, and
A cavity 35 is formed between the second compression core 73 and the first compression core 61.

The numeral 37 designates the molten resin in the cavity 35.
Injection device for filling the inside, 38 is a sprue bush, 3
9 is a return pin. In the injection compression apparatus having the above-described configuration, after the mold clamping step is completed, the cavity is filled with resin, and then the first and second injection compression steps are performed in a cooling step of cooling to a temperature at which a molded product can be taken out. Oil is supplied to the oil chambers 54, 69 in the blocks 51, 65, and the first and second injection compression pistons 53, 67 move toward the center of the injection molding machine, and the first and second ejector plates 5 are moved.
The first and second compression cores 61 and 73 are pressed and moved via the gates 7 and 72, and the resin filled in the cavity 35 is pressed.

In this way, the resin is compressed by an amount corresponding to the amount of shrinkage of the resin in the cooling step, thereby improving the surface accuracy of the molded product. In this case, since the resin is compressed from both sides, the pressure gradient is reduced, and no compression distortion occurs, so that the dimensional accuracy and surface accuracy of the molded product can be sufficiently improved.

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.

[0025]

As described above in detail, according to the present invention, in the injection compression apparatus, the stationary injection platen, the first injection compression block attached to the stationary platen,
A fixed mold attached to the first injection compression block,
A first injection / compression piston slidably disposed in the first injection / compression block, a means for moving the first injection / compression piston, and a first moving / moving member associated with the movement of the first injection / compression piston. A compression core, a movable platen, a second injection compression block attached to the movable platen, and a movable mold attached to the second injection compression block and forming a cavity in contact with and separated from the fixed mold. An ejector plate movably disposed between the second injection compression block and the movable mold, and an ejector plate slidably disposed within the second injection compression block and in contact with the ejector plate. A second injection / compression piston, means for moving the second injection / compression piston, and attached to the ejector plate for moving the second injection / compression piston. Go What has a second compressed core approaching and moving away from said first compressed core and an ejector rod disposed freely in contact with the ejector plate.

[0026]

In this case, the movable platen is moved,
After the fixed mold and the movable mold are brought into contact with each other to perform mold clamping, the cavity is filled with resin. Subsequently, when the molded article is cooled in the cooling step, the resin contracts. At this time, the first and second injection compression pistons are moved,
The first and second compression cores move toward the center. Therefore,
Insufficient resin is replenished due to shrinkage during the cooling step.

Further, since the resin is compressed from both sides, the pressure gradient is reduced, and no compression distortion occurs, and the dimensional accuracy and surface accuracy of the molded product can be sufficiently improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an injection compression device showing an embodiment of the present invention.

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

[Explanation of symbols]

 Reference Signs List 11 fixed platen 13 fixed mold 14 movable platen 24 movable mold 35 cavity 51 first injection compression block 53 first injection compression piston 61 first compression core 65 second injection compression block 67 second injection compression piston 73 second compression core

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-202334 (JP, A) JP-A-57-187231 (JP, A) JP-A-61-125824 (JP, A) JP-A-1- 20113 (JP, A) JP-A-5-301261 (JP, A) JP-A-3-39530 (JP, U) JP-A-4-5301 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/56-45/57 B29C 45/64-45/70

Claims (1)

(57) [Claims] 1. A fixed platen, (b) a first injection compression block attached to the fixed platen, (c) a fixed mold attached to the first injection compression block, and (d) A first injection compression piston slidably disposed in the first injection compression block, (e) means for moving the first injection compression piston, and (f) a movement of the first injection compression piston. (G) a movable platen, (h) a second injection compression block attached to the movable platen, and (i) an attachment to the second injection compression block and the fixing. A movable mold that forms a cavity by coming into contact with and separating from the mold; and (j) a movable mold between the second injection compression block and the movable mold.
There are, an ejector plate which is movably disposed, (k) slidably in the second injection-compression block, or
A second injection compression piston disposed so as to be in contact with the ejector plate ; (l) means for moving the second injection compression piston; and (m) a second injection compression piston attached to the ejector plate. A second compression core that moves with the movement of the piston and comes into contact with and separates from the first compression core ; and (n) is disposed so as to be freely contactable with the ejector plate.
An injection compression device comprising an ejector rod .