JP3166567B2 - Multi-material molding block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-material molding block capable of performing single molding, twin molding, sandwich molding and the like while using a single molding machine.

[0002]

2. Description of the Related Art Conventionally, one spool provided with two sets of injection units and combined (mixing nozzle) as a concentric annular multiple pipe in the middle of a nozzle portion by one mold clamping device is used. A co-injection injection molding machine (FIG. 8) in which two types of molten resin are sequentially injected by the two sets of injection units while being brought into contact with a mold having the same.
(1)) Alternatively, two sets of injection units are clamped by one mold clamping device, and two types of molten resin are placed in a mold having a spool facing each injection unit. A compound type having a combination of a so-called twin nozzle and a mixing nozzle, in which two colors are injection-molded by a nozzle portion arranged in a mold adjacent to a cavity portion after alternately injecting by an injection unit. A multilayer injection molding machine (FIG. 8 (2)) is known.

[0003]

However, in the case of the co-injection injection molding machine described above (FIG. 8A), since different resins are sequentially used for the outer layer and the inner layer, the spool and the runner are used. If the part is always in a hot state, the residual resin at the previous shot and the new resin at the next shot are easily mixed, and it is difficult to obtain a desired molded product.

For this reason, if the resin remaining on the spool or the runner portion is taken out as a burr at the time of taking out a molded product for each molded product, the occurrence of defective molded products due to the mixture of different kinds of resins as described above is prevented. Although possible, there was a problem that the product yield was reduced.

On the other hand, a composite type multi-layer molding machine (FIG. 8 (2))
Constitutes a so-called mixing nozzle portion in which a concentric multiple pipe is disposed in the mold adjacent to the mold cavity portion, and until a different kind of resin is injected and filled into the cavity portion. Since the resin passes through separate runner sections, the resin remaining on the heated spool and the runner section is easily used effectively in the next shot, but a fixed plate having a spool opposed to a plurality of injection units, There has been a problem that the injection molding machine needs to be largely remodeled, for example, by replacing it with a fixed mold or by changing the arrangement of the injection unit itself.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a multi-material molding block having a mixing nozzle or a twin nozzle between a fixed mold and an injection unit. It is an object of the present invention to shorten the replacement time by minimizing the replacement part by arranging the two injection devices in an eight-letter shape.

[0007]

In order to achieve the above-mentioned object, according to the present invention, there is provided a semiconductor device having a fixed die opposed to a fixed platen.
Is used for an injection molding machine that co-injects two or more types of resin by arranging the injection unit slidably back and forth, and a plurality of resin passages communicating between the fixed mold and the injection unit.
A multi-material molding block formed by a plastic,
By replacing a part of several blocks, the various
The structure can be changed to either a mixing nozzle structure in which the resin paths to be co-injected into the material molding block are merged in the middle or a twin nozzle structure in which the resin paths to be co-injected are independent.

[0008]

[Action] After completing the molding of a multilayer molded product (sandwich molding) with a front material and a backing material using a twin nozzle, the outer layer
In order to form a twin molded product having an inner layer, the molding is performed by replacing the mixing nozzle with the mixing nozzle. These molded products are the second block of the multi-material molding block interposed between the fixed mold and the injection unit. By simply exchanging blocks other than the above, it is possible to handle multilayer and multi-stage molding,
Efficient co-injection molding can be performed.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a multi-material molding block according to an embodiment of the present invention.

FIG. 1 is a partially cutaway front view of an injection molding machine according to the present invention, and FIGS. 2 to 4 are operation explanatory diagrams showing movements of a needle valve and a shaft off valve when a mixing nozzle is used. FIG. 5 is a cut-away plan view of a multi-material forming block when a twin nozzle is used, FIG. 6 is an operation explanatory view showing a molding state of a molded article having an outer layer and an inner layer using a mixing nozzle, and FIG. Surface material using
It is operation | movement explanatory drawing which shows the molding state of the molded article with a backing material.

First, an injection apparatus using the multi-material molding block according to the present invention will be described.

Reference numeral 5 denotes a fixing plate of a mold clamping device (not shown) provided on the left side (front side) of the head 3 of the injection molding machine 1 in the figure. The fixed platen 5 has an opening 6 of a predetermined size. In this opening 6, a multi-material molding block 10 interposed between a fixed die 7 and the injection unit 2 moves back and forth on a support base 8. It is arranged freely.

The injection unit 2 is composed of two injection units (2A, 2B), and is installed so that the injection unit 2 is formed in an octagonal shape as shown in FIG. 2, and the injection units (2A, 2B) Is the moving table 11 (11A, 11
B) Each of the hydraulic cylinders (4A,
4B) or other appropriate means.
B) is provided so as to be slidable back and forth between a position in contact with the contact portion 13 of the multi-material molding block 10 and a position separated therefrom. Further, the movable table 11 (11A, 11B) and the multi-material molding block 10 are arranged on the common movable table 11, and the tip contact portions of the mixing nozzle 35 and the twin nozzle 36 contact the spool 14 of the fixed mold 7. It can slide back and forth by a dedicated hydraulic cylinder 4 (4A, 4B) so that it can touch.

Here, a block having a structure of the mixing nozzle 35 in the multi-material molding block 10 according to the present invention will be described with reference to FIG. Multi-material molding block 1
Reference numeral 0 denotes a block nozzle 15 that contacts the spool 14 of the fixed mold 7, a tip block 16 that screwably holds the block nozzle 15, a first block 17, and a second block 1.
8. Needle valve 19 and needle valve driving cylinder 2
0.

As described above, at the tip of the multi-material molding block 10, that is, at the portion of the so-called block nozzle 15 and tip block 16, a cylindrical piece 21 is interposed at the tip of the first block 17 to form concentric inner and outer rings. A first injection unit 2A and a second injection unit 2B are formed to form a resin passage.
The molten resin respectively injected from the
7 parts are filled by injection and a molded product with inner and outer layers is
It is designed to be injection molded.

Reference numeral 22 denotes an inside passage, and 23 denotes an outside passage. Inside passage 22 and outside passage 23
Is communicated from the second injection unit 2B to the block nozzle 15 having concentric inner and outer annular resin passages via the second block 18, the first block 17, and the end block 16.

The inner and outer annular resin passages provided in the block nozzle 15 communicate with the outer passage 23 and are located on the outer side. The outer annular passage 25 and the inner passage 22 are located on the inner side. The inner annular passages 24 join together at a distal end port 26 of the blocking nozzle 15 and are connected to a hot runner 27.

A needle valve 19 connected to a needle valve driving cylinder 20 provided at the rear end of the multi-material molding block 10 to move back and forth to open or close the inner annular passage 24 is provided. It is arranged on ten axes.

Reference numeral 28 denotes a shut-off valve 28, which is rotatably disposed on the injection nozzle 12A of the first injection unit 2A and opens and closes a resin passage hole 29 provided in the injection nozzle 12A. Has become.

Next, a multi-material molding block 10 having a twin nozzle 36 for multilayer molding having a front material and a backing material will be described with reference to FIG. Only the parts different from the multi-material block 10 having the mixing nozzle 35 will be described.

An independent so-called twin nozzle 36 is attached to the end of the first block 17. The twin nozzle 36 is connected to the first nozzle 31 communicating with the outer passage 23 and the second nozzle 31 communicating with the inner passage 22. It is composed of a nozzle 32.

The leading end of the first nozzle 31 can be brought into contact with a spool 33A provided at the end of a hot runner 34A drilled in the fixed mold 7, and the leading end of the other second nozzle 32 is also provided. Like the first nozzle 31, the spool 33B provided at the end of the hot runner 34B can be in contact at the same time.

Then, by simply removing the first block 17 from the second block 18 and exchanging the parts incorporated at the tip from the first block 17 as one set, for example, a twin-molded product suitable for the mixing nozzle 35 The transition to a molded product suitable for the nozzle 36 can be performed smoothly.

Although not shown in this embodiment, only the periphery of the resin passage formed in the fixed mold 7 is locally heated while maintaining the two molds 7 and 9 at the solidification temperature of the resin. Although the embodiments have been described as the so-called hot runners 27, 34A, and 34B, the present invention is not limited to this, and the cold runner (the vicinity of the resin passage is not locally heated) by using the multi-material molding block 10 of the present embodiment is also possible. Good.
A sheath heater 40 is disposed around the inner passage 22 and the outer passage 23 formed in the multi-material molding block 10, and the resin passing through the inner and outer passages 22 and 23 is appropriately removed. Heating to a certain temperature.

Next, the operation when the multi-material molding block 10 is used will be described.

First, a case where a molded article having an outer layer and an inner layer is formed using a mixing nozzle is shown in FIGS.
6A and 6B, as shown in FIG. 6A, the stationary mold 7 and the movable mold 7 are fixed by an appropriate mold clamping device (for example, using a direct pressure type or a toggle type). The mold 9 is opened and clamped, and with the shut-off valve 28 opened, the screw of the first injection unit 2A is advanced into the cavity 37 formed between the molds 7 and 9 to make the skin material. Is injected and filled with resin A (FIG. 2, FIG. 6 (1)).

Then, a so-called outer layer is formed by injection-filling the resin A into the cavity 37. When molding a molded product having an outer layer and an inner layer by co-injection, a virgin material is used for the A resin, and a recycled material or a different material or a material having a different grade is used for the B resin that forms the core layer, which is a so-called inner layer. Use it.

Next, the needle valve driving cylinder 20 is driven to retract the needle valve 19 to form a communication passage for the resin between the second injection unit 2B and the cavity 37 (FIG. 3).

Subsequently, the shut-off valve 28 is rotated,
It is closed (FIG. 4). Then, the second injection unit 2B
The B screw as a core material is injected and filled into the cavity 37 through the inner passage 22 and the hot runner 27 in an appropriate amount (FIG. 6 (2)). Note that the first injection unit 2A and the second injection unit 2B can be simultaneously injected with the shut-off valve 28 kept open.

Thereafter, the shut-off valve 28 is opened, the needle valve 19 is advanced by the driving of the needle valve driving cylinder 20, and the inner annular passage 24 is closed. By advancing the screw and injecting and filling the resin A, the resin B as the core material is sealed by the resin A as the skin material, and a molded article having an outer layer and an inner layer is obtained.

Next, a case of forming a multilayer molded product having a front material and a backing material using the twin nozzle 36 will be described with reference to FIGS. 5 and 7. As shown in FIG.
Similar to the case where the mixing nozzle 35 is used, the fixed mold 7 and the movable mold 9 are closed and clamped by a mold clamping device (not shown).

First, the screw of the first injection unit 2A is advanced into the cavity 37 formed between the two dies 7, 9, and the resin A as the surface material is injected and filled (FIG. 7).
(1)). In the case of molding a molded product having a surface material and a backing material by co-injection, a virgin material is used as the resin A, and a recycled material or a different material or a material having a different grade is used as the backing material.

After injecting and filling an appropriate amount of the resin A as a surface material, the movable mold 9 is minutely opened by a mold clamping device (FIG. 7 (2)).

A resin B as a backing material is injected and filled into the cavity 37 formed between the solidified resin A and the fixed mold 7 (FIG. 7 (3)). 7 and the mold compression is performed.
(4)).

When a molded product having an outer layer or an inner layer or a multilayer molded product having a surface material and a backing material is molded by using the above-described mixing nozzle 35 or twin nozzle 36, the movable die 9 is fixed. The resin A and the resin B are injected while the temperature of the mold 7 is kept at the solidification temperature of the resin from beginning to end.

In this embodiment, a twin-headed nozzle has been described as the twin nozzle 36. However, the present invention is not limited to this, and a twin-nozzle having two or more so-called multi-nozzles can also be used.

[0037]

As is apparent from the above description, according to the present invention, the fixed die opposed to the fixed platen is opposed to the fixed die.
Is used for an injection molding machine that co-injects two or more types of resin by arranging the injection unit slidably back and forth, and a plurality of resin passages communicating between the fixed mold and the injection unit.
A multi-material molding block formed of
By replacing a part of the blocks, the various materials
One unit can be changed to either a mixing nozzle structure where the resin paths co-injected into the molding block merge in the middle or a twin nozzle structure where each resin path co-injected is independent. Efficient co-injection molding can be performed with any mold having a hot runner or a cold runner using the injection molding machine described above.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of an injection molding machine according to the present invention.

FIG. 2 is an operation explanatory view showing movements of a needle valve and a shut-off valve when a mixing nozzle is used.

FIG. 3 is an operation explanatory diagram showing a continuation of the operation in FIG. 2;

FIG. 4 is an operation explanatory diagram showing a continuation of the operation in FIG. 3;

FIG. 5 is a cut-away plan view of a multi-material molding block when a twin nozzle is used.

FIG. 6 is an operation explanatory view showing a molding state of a molded article having an outer layer and an inner layer using a mixing nozzle.

FIG. 7 is an operation explanatory view showing a molding state of a molded article having a front material and a back material using a twin nozzle.

FIG. 8 shows a conventional nozzle for molding a multilayer molded article.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Injection unit 2A 1st injection unit 2B 2nd injection unit 5 Fixed board 7 Fixed mold 9 Movable mold 10 Multi-material molding block 12 (12A, 12B) Injection nozzle 13 Contact part 14, 33A, 33B Spool 15 Blocking nozzle 16 End block 17 First block 18 Second block 19 Needle valve 20 Needle valve driving cylinder 21 Cylindrical piece 22 Inner passage 23 Outer passage 24 Inner annular passage 25 Outer annular passage 26 Tip opening 27 , 34A, 34B Hot runner 28 Shut-off valve 31 First nozzle 32 Second nozzle 35 Mixing nozzle 36 Twin nozzle 37 Cavity

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/24

Claims (1)

(57) [Claims] 1. A fixed die opposed to a fixed die attached to a fixed platen.
Is used for an injection molding machine that co-injects two or more types of resin by arranging the injection unit slidably back and forth, and a plurality of resin passages communicating between the fixed mold and the injection unit.
A multi-material molding block formed of
By replacing a part of the blocks, the various materials
It is characterized in that it can be changed to either a mixing nozzle structure in which the resin paths to be co-injected into the molding block merge on the way or a twin nozzle structure in which each resin path to be co-injected is independent. Multi-material molding block.