JP2721593B2 - Injection compression molding equipment - 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 molding apparatus.

[0002]

2. Description of the Related Art Conventionally, plastic lenses formed by injection molding have been used for some sunglasses and reading glasses.
A plastic lens is required as a high-precision optical component, and an injection compression molding method has been provided. In the injection compression molding method, after the injection is completed, the resin is uniformly compressed, the specific volume is reduced, and the molecular orientation is made uniform, thereby reducing the distortion of the residual stress of the molded product. In addition, the shrinkage of the molded product can be reduced to improve dimensional accuracy.

FIG. 2 is a sectional view of a conventional injection compression molding apparatus. In the drawing, 1 is a fixed-side mounting plate, 2 is a fixed-side receiving plate, 3 is a guide pin, 4 is a fixed-side die plate, 5 is a movable-side die plate, 6 is a movable-side receiving plate, 7 is a spacer block, and 8 is a spacer block. It is a movable side mounting plate. 9 and 10 are ejector plates, 11
Is an ejector pin. The ejector pin 11 has a mounting portion disposed between the ejector plates 9 and 10 and is supported by the ejector plates 9 and 10. When the mold is closed, it is brought into contact with the movable-side mounting plate 8, and when the molded product is protruded, it moves by the length of the protrusion.

A nozzle 13 is provided on the side of the fixed side mold plate 4 and the movable side mold plate 5 so as to come into contact with and separate from each other, and a nozzle for injecting the molten resin into the resin space 14 is provided. Is a guide pin for forming the In the injection compression molding apparatus having the above configuration, a first hydraulic cylinder (not shown) is provided above the fixed mounting plate 1, and a second hydraulic cylinder (not shown) is provided above the guide pin 16.
At the time of injection, a low pressure state is maintained only by the second hydraulic cylinder. When the injection is completed, pressure is applied by both the large ram of the first hydraulic cylinder and the second hydraulic cylinder.

When the injection and the holding pressure are completed, the ejector pins 1 and 10 are used to eject the ejector pins 1.
1 is moved so that a molded product in the resin space 14 is protruded.

[0006]

However, in the above-mentioned conventional injection compression molding apparatus, after the injection is completed, the second hydraulic cylinder is operated to compress the resin in the resin space 14; The protruding devices for protruding a later molded product are separately provided and operate independently, which complicates the mechanism.

Further, since the ejector pins 11 project by pressing the sides of the resin space 14, the ejector pins 11 project at multiple points and have poor parallel projection accuracy (straightness). The present invention solves the problems of the conventional injection compression molding apparatus described above,
It is an object of the present invention to provide an injection compression molding device that can simplify a mechanism by integrating a compression device and a protruding device and that can protrude in parallel with a single protruding device to improve accuracy.

[0008]

For this purpose, in an injection compression molding apparatus according to the present invention, a first mold plate, a cavity attached to the first mold plate, and a detachable and opposed facing cavity. A core that forms a space for filling the resin between the cavity and the cavity, a second template to which the core is attached, and the first and second templates relative to each other. Means for moving to

[0009] Further, an injection compression piston, which is provided on one of the first template and the second template so as to be able to contact and separate from the other and presses one of the templates by supplying oil,
Slidably disposed on the inner peripheral side of the injection compression piston,
An ejector rod for moving by hydraulic pressure to protrude one of the cavity and the core; and a means for moving the ejector rod forward and backward. The ejector rod has a large-diameter portion in the injection compression piston. And the small-diameter portion, the large-diameter portion protrudes to form a surface, and the large-diameter portion and the small-diameter portion form an engagement surface.

[0010]

According to the present invention, the first template is provided as described above,
A cavity attached to the first template, a core opposed to the cavity so as to be able to freely contact with and separate from the cavity, and forming a space for filling a resin between the cavity and a core to which the core is attached; 2 template, the first template and the second template.
Means for relatively moving the template.

Therefore, the cavity can be brought into contact with the core by moving one of the first mold plate and the second mold plate, and the resin can be filled in the resin space formed therebetween. An injection / compression piston, which is provided on one of the first template and the second template so as to be able to freely contact and separate from the other, and presses one of the templates by supplying oil; An ejector rod slidably disposed on the inner peripheral side of the piston for moving by hydraulic pressure to protrude one of the cavity and the core. The ejector rod has a large-diameter portion and a small-diameter portion in the injection-compression piston, and the large-diameter portion forms a protruding surface, and also forms an engagement surface between the large-diameter portion and the small-diameter portion. When the piston for injection compression is moved in the compression direction, the ejector rod is moved in the same direction by the engagement surface.

After the ejector rod is moved and ejected, and the ejector rod is retracted,
The injection compression piston can be simultaneously retracted by the engagement surface.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an enlarged view of a main part of the injection compression molding apparatus of the present invention, FIG. 3 is a schematic view of the injection compression molding apparatus of the present invention, and FIG. 4 is a sectional view of a mold. In the figure, 21 is a fixed side mounting plate, 22 is a fixed side receiving plate, 23 is a fixed side mold plate,
Reference numeral 24 denotes a movable mold plate arranged opposite to the fixed mold plate 23, 25 designates a movable receiving plate, and 26 is arranged to be able to advance and retreat with respect to the fixed attachment plate 21 via a rod 27. It is a movable side mounting plate.

The rod 27 penetrates through the fixed mounting plate 21 and is connected to a hydraulic cylinder 28. When the hydraulic cylinder 28 is operated, the movable mounting plate 26, the movable receiving plate 25, and the movable mold plate 24 are moved. To move up and down. When the movable mold plate 24 comes into contact with the fixed mold plate 23 and mold clamping is performed, the nozzle 20 horizontally moves from above the movable mount plate 26, and the two mold plates 23,
The resin is filled in the resin space between 24.

An injection compression device 30 is provided between the fixed side mounting plate 21 and the movable side mounting plate 26 for holding the resin pressure in the resin space when the injection is completed. Fixed. Next, the injection compression device 3
0 will be described. In FIG. 1, reference numeral 21 denotes a fixed-side mounting plate, on which the mounting support 3 is mounted.
1 is attached. The mounting support 31 has a sliding hole 33 for an injection compression piston 32. The injection compression piston 32 includes a large-diameter cylindrical portion 34,
A small-diameter cylindrical portion 35 and a piston portion 36 formed between the two cylindrical portions 34, 35 allow the small-diameter cylindrical portion 35 to slide in the sliding hole 33.

An oil passage 38 for supplying oil for urging the injection compression piston 32 upward is formed in the mounting support 31, and when oil is supplied to the oil passage 38, the piston portion 36 Moves upward, and the large-diameter cylindrical portion 34
Presses the fixed-side receiving plate 22 and the fixed-side mold plate 23.
Due to this pressing force, the resin pressure in the resin space between the two mold plates 23 and 24 increases.

A hole 40 surrounding the large-diameter cylindrical portion 34 and a stamping block 42 forming a cylinder chamber 41 surrounding the piston portion 36 are fixed to the mounting support 31, and the large-diameter cylindrical portion 34 is fixed. Moves inside the hole 40, and the piston portion 36 slides in the cylinder chamber 41. Also,
The axial dimension of the piston portion 36 is smaller than the axial dimension of the cylinder chamber 41, and the difference a between the two is the stamp stroke.

An ejector rod 45 is slidably disposed inside the injection / compression piston 32 having the above configuration, and a hydraulic ejector mechanism 46 is disposed below the ejector rod 45. The ejector rod 45 is driven by a hydraulic ejector mechanism 46 and moves by a distance b.
The distance b is an ejector stroke. The ejector rod 45 has a large-diameter portion 47 from the large-diameter cylindrical portion 34 to the piston portion 36 and a small-diameter portion 48 from the piston portion 36 to the small-diameter cylindrical portion 35. 32, the slidability is improved.

As described above, the stamping block 4
An injection compression piston 32 is incorporated in an intermediate portion between 2 and the mounting support 31, and an ejector rod 45 that is also used for injection compression is built in the injection compression piston 32. The compression surface and the protruding surface of the ejector rod 45 are flush with the punch surface at the return position, so that the parallelism and the straightness can be maintained with high accuracy.

The injection compression piston 32 has a large compression force close to the mold clamping force, and the return also serves as the return of the hydraulic ejector mechanism 46. The ejector rod 45 is protruded when the molded product is taken out, and the ejected robot takes out the molded product. The ejector rod 45 forms an engagement surface 49 between the large diameter portion 47 and the small diameter portion 48. That is, when the injection compression piston 32 moves upward, the ejector rod 45
When the ejector rod 45 is retracted, the injection compression piston 32 is similarly retracted by the engagement surface 49. Therefore, when the ejector rod 45 is returned after removing the molded product, the injection compression piston 32 also returns together.

Next, the cross section of the mold will be described. FIG.
, 22 is a fixed side receiving plate, 23 is a fixed side template, 24
Denotes a movable mold plate, and 25 denotes a movable receiving plate. Reference numeral 51 denotes a resin space, and the upper cavity 52 and the lower core 5
3 formed. p is a parting surface. 5
Reference numeral 4 denotes an ejector that moves in conjunction with the ejector rod 45, and projects the core 53 and the molded product when the ejector projects.

In the injection compression molding apparatus having the above-described structure, when the hydraulic cylinder 28 operates to move the movable-side mounting plate 26, the movable-side receiving plate 25, and the movable-side mold plate 24 downward, the fixed-side mold plate 23 The movable mold plate 24 contacts the core 53
A resin space 51 is formed between the resin space 51 and the cavity 52. Then, the nozzle 20 moves horizontally from the side of the movable-side mounting plate 26, and the resin is filled in the resin space 51 between the two mold plates 23 and 24 to perform injection.

When the resin that sufficiently fills the resin space 51 is injected, the resin is cooled as it is. Then, oil is supplied to the oil passage 38 at an arbitrary timing from the start of injection to the end of cooling, and the injection compression piston 32 is moved upward. As a result, the ejector 54 moves upward, the pressure of the resin in the resin space 51 increases, and injection compression is performed.

After the resin in the resin space 51 is solidified, the mold is opened, the hydraulic ejector mechanism 46 is operated, the ejector rod 45 and the ejector 54 are ejected, and the core 53 is ejected together with the molded product. . The molded article is taken out by a take-out robot. Thereafter, when the hydraulic ejector mechanism 46 operates to lower the ejector rod 45 and the ejector 54, the injection compression piston 32 also returns at the same time.

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 these are not excluded from the scope of the present invention.

[0026]

As described above in detail, according to the present invention, one of the first template and the second template is disposed so as to be able to freely contact with and separate from one of the first template and the second template. An injection compression piston that presses one of the template plates, and an ejector rod that is slidably disposed on the inner peripheral side of the injection compression piston and that is moved by hydraulic pressure to protrude either the cavity or the core. Means for moving the ejector rod forward and backward. The ejector rod has a large diameter portion and a small diameter portion in the injection compression piston, and the large diameter portion constitutes a protruding surface. An engagement surface is formed between the diameter part and the small diameter part.

Therefore, since the ejector rod has the same wide plane as the injection compression piston, the straightness is excellent, the influence of the eccentric resin pressure is eliminated, and the precision of the molded product is improved. In addition, since the ejector rod is shared between the injection compression and the ejector projection, the translation accuracy is increased, and a highly accurate molded product can be formed.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of an injection compression molding apparatus according to the present invention.

FIG. 2 is a sectional view of a conventional injection compression molding apparatus.

FIG. 3 is a schematic view of an injection compression molding apparatus according to the present invention.

FIG. 4 is a sectional view of a mold.

[Explanation of symbols]

 Reference Signs List 21 fixed-side mounting plate 23 fixed-side template (second template) 24 movable-side template (first template) 31 mounting support 32 injection compression piston 33 sliding hole 34 large-diameter cylindrical portion 35 small-diameter Cylindrical part 36 Piston part 38 Oil passage 41 Cylinder chamber 42 Stamping block 45 Ejector rod 46 Hydraulic ejector mechanism 47 Large diameter part 48 Small diameter part 49 Engagement surface 52 Cavity 53 Core

Claims (1)

(57) [Claims] (A) a first template, (b) a cavity attached to the first template, and (c) a cavity which is disposed so as to be able to freely contact and separate from the cavity and face the cavity. A core forming a resin space for filling resin therebetween, (d) a second template to which the core is attached, and (e) a first template and a second template relative to each other. Means for moving;
(F) an injection-compression piston, which is disposed on one of the first template and the second template so as to be able to freely contact with and separate from the other, and presses one of the templates by supplying oil. E) an ejector rod slidably disposed on the inner peripheral side of the injection compression piston and moved by hydraulic pressure to protrude one of the cavity and the core; and (h) moving the ejector rod forward and backward. Means of
(I) The ejector rod has a large-diameter portion and a small-diameter portion in the injection-compression piston, and the large-diameter portion forms a protruding surface and an engaging surface between the large-diameter portion and the small-diameter portion. An injection compression molding apparatus characterized by the above-mentioned.