JPS6341150Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mold for injection compression molding which is simple and economically constructed and which can achieve a high level of surface accuracy without causing sink marks even though the mold is thick, such as a lens or prism.

Conventional injection compression molding molds can be roughly divided into the following two types. The method shown in FIG. 1 will be described as (1), and the method shown in FIG. 2 will be described as (2).

(1) The method shown in Figure 1 will be briefly explained. Either provide a degree between the fixed side mold and the movable side mold, or equip the injection molding machine with a two-stage mold clamping mechanism to perform injection in an incomplete mold clamped state with a compression allowance, and then complete mold clamping. to achieve compression. A mold using degree determination will be explained using FIG. The cavity 1 is formed by a fixed mold 2, a movable mold 3, and a side plate 4. Even in the incomplete mold clamping state where the tensioning device 6 disposed between the fixed mold 2 and the movable mold 3 acts, the side plate 4 is pressed against the fixed mold 2 by the spring 5, so the cavity 1 is sealed. There is. After injection, the adjustment 6 is released and compression is performed. 1st
The left half of the center of the figure shows the operating state of the tension setting 6, and the center right half shows the release and compression state of the tension setting 6.

The disadvantage of this mold, which can be easily understood from FIG. 1, is that the compression direction is limited only to the mold clamping direction.

An even bigger drawback is that it is not possible to use side gates, which are often used in thick-walled molding, because it is necessary to seal the cavity with a side plate, and pinpoint gates cannot suppress sink marks to a satisfactory level. Nor can they be hired. Therefore, it is virtually impossible to produce multiple molded products as is common sense.

(2) The method shown in Figure 2 will be briefly explained. A core is provided that can slide against the template, and compression is achieved by driving the core with hydraulic pressure after injection. A mold for hydraulically driving a core will be described with reference to FIG. The cavity 11 is formed by a fixed mold 7, a movable mold 8, and a slidable core 9. The core 9 is injected with the mold completely closed, and then the core 9 is driven in the direction of arrow A by the hydraulic mechanism 10 to achieve compression.

The disadvantage of this type is that the compression direction is limited to the hydraulic drive direction. Therefore, for example, in the case of compression in a direction perpendicular to the mold clamping direction, it is necessary to arrange a hydraulic mechanism on an extension line of the compression direction, but this is practically impossible due to lack of sufficient space.

Furthermore, incorporating the hydraulic mechanism into the mold itself causes the mold to be larger and more expensive than necessary.

Furthermore, since the size of the hydraulic mechanism that can be built into the mold is limited, the compression area increases in the case of multiple molds, resulting in the problem that the necessary compression force cannot be obtained.

The present invention aims to improve the above-mentioned drawbacks and to provide a practical injection compression mold.

The injection compression molding mold of the present invention includes a movable side mold, a fixed side mounting plate, and a fixed side mold plate provided between the movable side mold and the fixed side mounting plate, which are in contact with or separated from each other. In the injection compression molding mold, the movable side mold has a concave movable side mold stopper gap inserted so that the bottom surface of the collar of a stopper having a collar at an end fixed to the fixed side mounting plate comes into contact with the movable side mold. and a concave sprue portion, a gate portion, and a core portion that are connected to each other, and the fixed side mold plate is further disposed from the collar portion provided so as to correspond to the center of the movable side mold stopper gap. A stopper through hole portion with a small opening area, a hole-shaped sprue portion connected to the sprue portion of the movable side mold, and a concave core that pairs with the core portion of the movable side mold on a surface side in contact with the movable side mold. a spring concave portion housing a spring that maintains a gap between the fixed side mounting plate and the fixed side mounting plate during non-injection compression; and a spring recessed portion that is slidable and communicates with the concave core portion from both sides in contact with the fixed side mounting plate. and a cylinder through hole into which the core is inserted, and the fixed side mounting plate is provided corresponding to the stopper hole into which the stopper is fixed and the spring recess provided in the fixed side template. a mounting plate spring recess; a sprue portion connected to the stationary template;
A recessed portion having a size that allows the core pressing plate to be movable, the core pressing plate having a compression pressing portion that is a surface parallel to the surface in contact with the fixed side template, and an injection pressing portion that is a surface that is recessed from the contacting surface. The core pressing plate is characterized in that compression is performed when the compression pressing part of the core pressing plate comes into contact with the slidable core, and injection can be performed when the injection pressing part comes into contact with the core. The explanation will be based on the embodiments of the present invention shown in FIGS. 3a, b, and c.

First, as shown in FIG. 3a, resin is filled into the cavity 12 through the sprue portion 12b and the gate portion 12a in a completely clamped state.
Next, as shown in FIG. 3b, the movable mold 13 is moved back by distance c and temporarily stopped. During this time, the fixed mold plate 14 is pressed against the movable mold 13 by the spring in the spring recess 15a that accommodates the spring 15. At this time, the movable side mold 13 and the fixed side mold plate 14 slide and retreat with respect to the guide pin 17 fixed to the fixed side mounting plate 18, so the movable side mold 13 and the fixed side mold plate 1
4 and the fixed side mounting plate 18 will not be misaligned. Further, the fixed side mold plate 14 has a cylinder through hole 16a connected to the cavity, and a slidable core 16 is provided therein, and the core 16 retreats together with the fixed side mold plate 14. In this state, the fixed side mounting plate 1
A gap C is created between 8 and the stationary template 14. Next, the core pressing plate 20 is driven in the direction of arrow E by the air cylinder 19, so that the bottom of the core 16 is pressed into the compression pressing portion 20-1 of the core pressing plate 20.
Stop the drive at the position where it hits. For this reason, it is necessary that the retraction amount C be larger than the compression allowance B. Next, complete mold clamping is performed again as shown in FIG. 3c. During injection, the core 16 comes into contact with the injection pressing part 20-2 of the core pressing plate 20, and during compression (when re-completely clamping the mold), the core 16 contacts the compression pressing part 20-2 of the core pressing plate 20.
1, the difference in level between the pressing part 20-1 during compression and the pressing part 20-2 during injection becomes the compression allowance B.

Compression is achieved through the above steps. When cooling is completed, the mold is opened, and the stopper 21 fixed to the fixed side mounting plate 18 closes the fixed side mounting plate 18.
The opening amount between the fixed side mold plate 14 and the fixed side mold plate 14 is regulated to D, which is slightly larger than C. (C is shown in Figure 3b.D
is illustrated in Figures 3a and c. ) Therefore, the stationary template 14 will not come off. As the mold opening progresses further, an appropriate gap is created between the stationary mold plate 14 and the movable mold 13, allowing mold release. Moreover, at the time of this mold release, the core pressing plate 20 is returned to its normal position by the air cylinder 19.

Usually the core is fixed to the compression mechanism, but in the present invention it is independent and can be compressed in any direction. Therefore, restrictions on mold design are also greatly reduced.

Furthermore, in the present invention, since the core can be moved with the gap between the stationary side mold plate and the movable side mold plate closed, it is possible to employ a side gate.

Furthermore, in the present invention, the compressive force is obtained from the clamping force of the injection molding machine, so that sufficient compressive force can be obtained even when molding multiple pieces.

Furthermore, since the mold of the present invention does not require any special components, it is possible to obtain an inexpensive mold for injection compression molding.

Furthermore, since the compression mechanism of the mold of the present invention is simple, the size of the mold is almost the same as that of a normal mold.

As explained above, the present invention is an effective invention that can extremely easily realize injection compression molding.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional embodiment (1). 1... Cavity, 2... Fixed side type, 3... Movable side type, 4... Side plate, 5... Spring, 6... Degree determination. FIG. 2 is an explanatory diagram of the conventional embodiment (2). 7... Fixed side type, 8... Movable side type, 9... Core, 10... Hydraulic mechanism, 11... Cavity. Figures 3a, b, and c are diagrams showing embodiments of the present invention. FIG. 3a is a diagram showing a complete mold clamping injection filling state. FIG. 3b is a diagram showing temporary mold opening and movement of the core pressing plate. FIG. 3c is a diagram showing a re-completely clamped and compressed state. 12... Cavity, 13... Movable side mold, 12
a...Gate part, 12b...Sprue part, 14...
... Fixed side mold, 15 ... Spring, 15a ... Spring recess, 16 ... Core, 17 ... Guide pin, 16a
... Cylinder through hole section, 18 ... Fixed side mounting plate,
19...Air cylinder, 20...Core pressing plate, 21...Stopper, 21a...Movable side mold stopper gap, 21b...Stopper through hole, 21c...Stopper hole, 21d...Brim portion.

Claims (1)

[Claims for Utility Model Registration] A movable side mold that is in contact with or separated from each other, a fixed side mounting plate, and a fixed side mold plate provided between the movable side mold and the fixed side mounting plate. In the mold for injection compression molding, the movable side mold has a concave movable side mold stopper gap that is inserted so that the bottom surface of the collar of a stopper having a collar at the end fixed to the fixed side mounting plate comes into contact with the movable side mold. , has a concave sprue portion, a gate portion, and a core portion that are connected to each other, and the fixed side mold plate has an opening from the flange portion provided so as to correspond to the center of the movable side mold stopper gap. A stopper through hole with a small area, a hole-shaped sprue portion connected to the sprue portion of the movable side mold, and a concave core portion that pairs with the core portion of the movable side mold on a surface side in contact with the movable side mold. a spring concave portion housing a spring that maintains a gap between the fixed side mounting plate and the fixed side mounting plate during non-injection compression; and a slidable core that communicates with the concave core portion from both sides in contact with the fixed side mounting plate. and a cylinder through hole into which the stopper is inserted, and the fixed side mounting plate has a stopper hole into which the stopper is fixed, and a mounting plate provided corresponding to a spring recess provided in the fixed side template. a leaf spring recess; a sprue portion that connects with the stationary template;
A recessed portion having a size that allows the core pressing plate to be movable, the core pressing plate having a compression pressing portion that is a surface parallel to the surface in contact with the fixed side template, and an injection pressing portion that is a surface that is recessed from the contacting surface. , An injection compression molding molding die, characterized in that the compression pressing part of the core pressing plate is configured to perform compression when it comes into contact with the slidable core, and to perform injection when the injection pressing part comes into contact with it. Type.