KR102361080B1 - A mold device for form injection molding - Google Patents

Abstract

The present invention proposes a simple mold apparatus capable of performing foam injection molding. The moving-side mold of the present invention includes a moving-side fixed plate 10, a moving-side fixed plate 12 supported on the moving-side fixed plate 10, and a core pocket 14 connected to the moving-side fixed plate 12 at regular intervals. , a core 30 capable of only linear reciprocating motion from the inside of the moving side fixing plate 12 and the core pocket 14 toward the stationary side, a servomotor and a gear train for linearly reciprocating the core 30 . And the fixed-side mold is supported on the inside of the fixed-side fixed plate 20, the fixed-side fixed plate 22 supported by the fixed-side fixed plate 20, and the fixed-side fixed plate 22, and forms a cavity like the pocket 30. and a template 24 for forming it. When the central axis of the driven gear 36 rotates by driving the servo motor, the inner threaded portion 28 interlocks with the spiral groove 30a to bring the core 30 close to and spaced apart from the template 24 . Enables foam injection.

Description

A mold device for form injection molding

The present invention relates to a mold apparatus for foam injection molding, and more particularly, to a mold apparatus for foam injection molding configured to enable control of foam injection molding with a simple configuration using a servo motor.

Foam injection is performed by filling the cavity of the mold with the molten resin to be foamed and then precisely controlling the movable mold during the foaming process. In order to produce such a foamed product, it is necessary to use a core-back injection molding machine capable of ultra-precise mold opening/closing control. And the core-back operation is possible with an electric injection molding machine and a special injection molding machine with a core-back function.

In the case of electric injection molding machines, the opening and closing of the clamping part can be precisely controlled by servomotor control, but there is a limit to the clamping force, so the range of options is narrow, and there is a disadvantage that it is quite expensive compared to general hydraulic injection molding machines. And since the ultra-precision core-back injection molding machine is also quite expensive, it is inevitably economically burdensome. In the case of a general general-purpose hydraulic injection molding machine, the core-back operation can be implemented by modifying the operation program and adding a sensor, but there is a disadvantage in that the precision of mold opening and closing is significantly lowered.

An object of the present invention is to enable foam molding using a general general-purpose injection molding machine. This can be said to mean that the core-back operation can be performed through the addition of the simplest configuration, so that the operation reliability can be sufficiently secured while being economically advantageous.

The moving-side mold of the present invention includes a moving-side fixed plate, a moving-side fixed plate supported by the moving-side fixed plate, a core pocket connected to the moving-side fixed at regular intervals, and a straight line from the inside of the moving-side fixed plate and the core pocket toward the fixed side. It includes a core capable of only reciprocating motion and a linear driving means for linearly reciprocating the core. The fixed-side mold includes a fixed-side fixed plate, a fixed-side fixed plate supported by the fixed-side fixed plate, and a template that is supported inside the fixed-side fixed plate and forms a cavity like a pocket. Here, by the linear driving means, foam injection is possible as the core approaches or moves away from the template.

And according to the embodiment of the linear driving means, it includes a servomotor, a driving gear rotating by the servomotor, a driven gear rotating in mesh with the driving gear, and a central shaft supported by the center of the driven gear. And the outer end of the central shaft is inserted and supported in the support groove of the moving side support, and the inner end of the central shaft is formed with a screw thread and screwed into the spiral groove on the outside of the core. can reciprocate in a straight line.

According to another embodiment of the present invention, the core pocket includes a base, a movable side support, and an edge portion supporting only a linear reciprocating motion in a state in which the core is inserted therein. A protruding portion extending toward the core pocket is formed on the edge portion of the template, and a coupling groove to which the projecting portion is coupled is formed at the edge portion of the core pocket.

According to the present invention having the configuration as described above, it can be seen that the pocket is installed in the moving side mold, and the pocket is configured to be linearly moved by the servo motor and the gear train. When these pockets form one surface of the cavity, the foaming process can be smoothly performed by moving (retreating) outward during the foaming process. According to the present invention as described above, the advantage of enabling foam injection while having the simplest configuration can be expected.

1 is an exemplary cross-sectional view showing a state in which the core of the present invention is advanced in a closed state.
Figure 2 is an exemplary cross-sectional view showing a state in which the core is retracted in the state in which the mold apparatus of the present invention is closed.
Figure 3 is a process example showing the foam injection process using the mold apparatus of the present invention by way of example.

Next, based on the embodiment shown in the drawings, the present invention will be looked at more closely.

Fig. 1 shows a state in which the mold is closed (mold closing), and Fig. 2 shows a state in which the core is advanced (moved into the cavity) in a state in which the mold is closed. As can be seen from this reference, the moving side (mold) of the present invention includes a moving side fixing plate 10 and a moving side support 12 installed on the moving side fixed plate 10 . And a core pocket 14 is connected to the moving side support 12, and this core pocket 14 is connected to the moving side support 12 in a part. Except for this connected part, a certain space is formed between them, have.

Gear groups 32 and 34 and a servomotor 31 are installed in a space formed in a portion between the moving side support 12 and the core pocket 14 . The drive gear 32 provided on the output shaft of the servomotor 31 is provided in a meshed state with the driven gear 34 . And it is designed to rotate like the central shaft 36 of the driven gear 34, the end (end toward the fixed side) of this central shaft 36 is provided with a threaded portion 18 with a threaded thread.

The core pocket 14 coupled to the movable side support 12 maintains the state in which the core 30 is accommodated therein. That is, the core pocket 14 includes a base 14a connected to the movable side support 12 and an edge portion 14b that supports only a linear reciprocating motion while the core 30 is inserted therein. are being prepared Since the edge portion 14b is brought into contact with the outer surface of the core 20, the core 30 can be said to be in a regulated state except for linear reciprocating motion. Here, the threaded portion 18 of the central shaft 36 penetrates the core pocket 14 and the end thereof is coupled to the spiral groove 30a outside the core 30 .

And on the inner circumferential surface of the spiral groove 30a formed on the back surface of the core 30 (in the opposite direction to the fixing side), a female thread capable of being screwed with the threaded portion of the central shaft 36 is formed. And since the core 30 is supported so that only linear motion (left and right direction in the drawing) is possible by the rim portion 14b of the core pocket 14, the threaded portion 38 is rotated according to the rotation of the central shaft 36. When rotated, the core 30 has no choice but to linearly move in the left and right directions. The outer side (in the direction of the outer end of the moving side) end of the central shaft 36 is inserted into the support groove 12a of the moving side support 12 , so that rotation by the driven gear 34 can be stably supported. A plurality of springs 18 are interposed between the core 30 and the core pocket 14 to elastically support the core 30 to the fixed side.

Next, the configuration of the fixed side (mold) will be described. On the fixed side, a fixed-side fixed plate 20 and a fixed-side supporter 22 connected to and supported by the fixed-side fixed plate 20 are provided. And a fixed-side template 24 is provided inside the fixed-side support 22 . This fixed-side template 24 forms a cavity substantially like the core 30 described above. A coupling protrusion 24a is formed on the edge of the fixed side template 24, and a coupling groove 14c is formed on the edge of the core pocket 14 corresponding thereto. configured to be combined.

And a device for ejecting the product is provided on the fixed side, for example, the hydraulic cylinder 44, the push plate 46 moving by the hydraulic cylinder 44, and the push plate 46 to eject the product A push bar 48 and the like are installed. Since the device for such an ejection is not substantially directly related to the present invention, a detailed description thereof will be omitted.

Next, an injection process of the apparatus of the present invention will be described with reference to FIG. 3 . 3A shows a state in which injection is in progress in a state in which the mold is substantially closed (mold closed). Such a state can be said to be a state in which the cavity 33 has a predetermined volume before foaming. After the injection is completed in this way, as shown in (b), by the rotation of the servomotor 31, the driving gear 32 and the driven gear 34 are rotated. Therefore, according to the rotation of the central shaft 36, it is molded on the side of the core 30 of the central shaft 36, the threaded portion 38 is also rotated.

According to the rotation of the threaded portion 38 screwed to the spiral groove 30a of the core 30, the core 30 is located inside the core pocket 14 so as not to rotate, so that a linear motion in the left and right direction is performed. will perform In the process (b), since the volume of the cavity 33 must be increased in the process of substantially foaming, the core 30 moves to the left in the drawing (reverses the core) to increase the volume of the cavity 33 .

When the process (b) is completed, it can be said that the foam injection process is substantially completed. And in the process (c), the moving side mold moves and the mold is opened, and in the process (d), the product is ejected. Such (c) and (d) processes can be said to correspond to a conventional one in injection molding using a mold.

According to the present invention as described above, it can be seen that a mold apparatus capable of responding to foaming is proposed by linearly reciprocating the core 30 using the servomotor 31 at regular intervals. It can be said that it is natural that various modifications will be possible within the technical scope of the present invention, and that the protection scope of the present invention should be interpreted based on the description of the claims is also natural for the purpose of the provisions of the Patent Act. can

10 .... Moving side fixing plate
12 ..... Moving side support
14 ..... Core Pocket
14a ..... Bass
14b ..... Border
14c ..... Joining groove
20 ..... Fixed side fixing plate
22 ..... Fixed side support
24 ..... template
24a ..... junction protrusion
30 ..... core
31 ..... Servo motor
32 ..... drive motor
34 ..... driven motor
36 ..... central axis
38 ..... Threaded part

Claims (3)

The moving-side fixed plate 10, the moving-side fixed plate 12 supported by the moving-side fixed plate 10, the core pocket 14 connected to the moving-side fixed plate 12 at regular intervals, and the moving-side fixed plate 12, a moving-side mold including a core 30 capable of only linear reciprocating motion toward the fixed side within the core pocket 14, and a linear driving means for linearly reciprocating the core 30;
A fixed-side fixed plate 20, a fixed-side fixed plate 22 supported by the fixed-side fixed plate 20, and a template 24 supported inside the fixed-side fixed plate 22 and forming a cavity like the core 30 A fixed side mold comprising a; and
a plurality of springs 18 interposed between the core 30 and the core pocket 14 to elastically support the core 30 toward the fixed-side mold side;
The linear driving means includes a servomotor 30, a driving gear 32 rotating by the servomotor, a driven gear 34 rotating in mesh with the driving gear, and a central shaft 36 supported at the center of the driven gear. composed,
The outer end of the central shaft 36 is inserted and supported in the support groove 12a of the moving side support 12 , and the inner end of the central shaft 36 is formed with a threaded portion 38 , and is formed outside the core 30 . It is screwed into the spiral groove 30a, and when the central shaft 36 is rotated by the rotation of the servomotor 30, the core 30 can linearly reciprocate;
The core pocket 14 includes a base 14a, a movable side support 12, and an edge portion 14b that supports only a linear reciprocating motion while the core 30 is inserted therein;
A protruding portion 24a extending toward the core pocket 14 is formed in the edge portion of the template 24, and a coupling groove in which the protruding portion 24a is coupled to the edge portion 14b of the core pocket 14 ( 14c) is a mold device for foam injection molding.






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