JPH09155913A - Twin-screw extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recombine nozzle mechanisms under the state that the relative position of an injection unit to a molder main body, which is a heavy part, is kept unchanged without being dismounted for multifunctionalizing an extruder in the twin-screw extruder having a first injection unit connecting through a first runner block to one injection head and a second injection unit connecting through a second runner block to the injection head. SOLUTION: In a twin-screw extruder, under the state that the relative position among a first injection unit 3, a second injection unit 4 and an injection head 5 arranged on a travelling stand is kept unchanged, by shutting off the resin paths of the injection head 5 from a first and a second runner blocks communicating the resin paths of both the injection units 3 and 4 with the resin path of the injection head 5, the multifunctionalization is relized through the attaching and detaching and exchange between a first nozzle unit 8 and a second nozzle unit 9 respectively equipped with single nozzles 22 and 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multifunctional twin-screw injection molding machine capable of sandwich molding (two-layer molding), two-color molding and single molding with one injection molding machine.

[0002]

2. Description of the Related Art Conventionally, an injection molding machine capable of sandwich molding (two-layer molding) in which two types of injection units mounted on a biaxial injection molding machine are connected and integrated with an injection head through a runner block, and Various injection molding machines capable of two-color molding in which a nozzle unit is connected to each type of injection unit are provided and known.

A conventional example of such a twin-screw injection molding machine is shown in FIG. As shown in FIG. 5, the first ejection unit 3, the second ejection unit 4, and the ejection head 5 are arranged at fixed positions on a moving table (not shown), and the heads 11 and 12 of both ejection units 3 and 4 are disposed. The screw 13,
14 is inserted, and resin passages 11a and 12a and connection surfaces 11b and 12b are formed at the tip end portions.

A nozzle 16 is screwed on the tip of the valve body 15 of the injection head 5, and a cylindrical outer plunger 17 is disposed concentrically within the shaft center. The outer plunger 17 has a shaft. Inner plungers 18 are slidably inserted in the core holes, respectively.

An outer resin passage 19 communicating with the second injection unit 4 is formed between the inner peripheral surface of the valve body 15 and the outer peripheral surface of the outer plunger 17, and the inner peripheral surface of the outer plunger 17 and the inner plunger 18 are connected to each other. In between
An inner resin passage 19 ′ communicating with the first injection unit 3 is formed.

Further, valve seats are formed on the inner peripheral tip of the valve body 15 and the outer peripheral tip of the outer plunger 17 so as to be in contact with each other, and the valve seats are in contact with each other at the inner peripheral tip of the outer plunger 17 and the outer peripheral tip of the inner plunger 18. Each resin passage is opened and closed by the reciprocating operation of a hydraulic cylinder (not shown).

The first injection unit 3 and the second injection unit 4 are connected to an injection head 5 via a first runner block 6 and a second runner block 7. Both runner blocks 6 and 7 are provided with resin passages 6a and 7a. The resin passage 11a of the first injection unit 3 and the resin passage 15a of the valve body 15 are communicated with each other by the resin passage 6a of the first runner block 6. The resin passage 12a of the second injection unit 4 and the resin passage 15b of the valve body 15 communicate with each other through the resin passage 7a of the second runner block 7.

In the twin-screw injection molding machine configured as described above, various ones in which two types of injection units are connected to one injection head are provided (Japanese Patent Publication No. 60-5912).
9, Japanese Patent Publication No. 4-78451, etc.), and detailed description of the operation thereof will be omitted.

Further, in a two-color injection molding machine in which nozzle units are connected to two types of injection units, respectively, replaceable nozzles (T type) are connected, and single molding, two-color molding and sandwich molding are possible. As such a multifunctional twin-screw injection molding machine, there are those disclosed in Japanese Patent Publication No. 4-78450 and JP-A-6-23794.

[0010]

DISCLOSURE OF THE INVENTION In a twin-screw injection molding machine capable of sandwich molding (two-layer molding) with two injection units in the prior art and one injection head, both injection units are used for two-color molding. After removing the connected runner block and injection head, each nozzle unit was exchanged and connected at the tip of both injection units.

In the replacement work, there are incidental works including attachment / detachment of the heating means of the injection head. Since the injection head is heavy, it is a work using another lifting means, and the nozzle head is also used. It is necessary to align the holding means and the injection port, and in the return work as well, fixing the injection head, mounting the heating means, and fixing the nozzle unit require replacement work by many people (multiple people). There was a problem that the performance was poor and the cost increased.

According to the present invention, in the above-mentioned twin-screw injection molding machine, the nozzle mechanism is rearranged to be multifunctional while the relative position between the injection head and the injection unit is maintained without removing the heavy injection head. .

[0013]

Biaxial injection molding with one injection head having a first injection unit connected via a first runner block and a second injection unit connected via a second runner block. In order to solve the above problems in a machine, the present invention provides a twin-screw injection molding machine having the following structure.

First of all, the resin passages of both the injection units and the injection heads are connected in a state where the relative positions of the first injection unit and the second injection unit arranged on the moving table and the injection head are held. The first runner block and the second runner block are cut off from the resin passage between the injection head, and the first nozzle unit and the second nozzle unit having a single nozzle are attached / detached / replaced to / from the runner block. It is a twin-screw injection molding machine with a structure that enables dual-layer molding), two-color molding, and single molding (multifunctional).

A biaxial injection molding machine having an original structure in which the first injection unit and the second injection unit and the injection head are connected by a detachable first runner block and a second runner block and arranged and fixed on a movable table. The injection molding operation in this state is the same as the conventional one, and the description thereof is omitted.

Next, when performing two-color molding with this twin-screw injection molding machine, after removing both runner blocks, the first nozzle unit and the second nozzle unit, which block the resin passage from the injection head, are assembled. The resin plasticized by both injection units is introduced into the resin passages of the nozzle units connected to each injection unit, and the nozzles attached to the tips of both nozzle units contact the mold inlet part as the moving table advances. The plasticized resin is contacted and injected into the mold to form a product.

In the above-described twin-screw injection molding machine according to the present invention, sandwich molding is carried out by attaching / detaching / replacing either one of the two runner blocks connecting the injection unit and the injection head, and the nozzle unit. Dual-layer molding), two-color molding, and single molding (multifunctional) may be possible.

As described above, after removing either the first or second runner block, by assembling the first or second nozzle unit, which blocks the resin passage from the injection head, the two injection molding units are plasticized. The resin to be converted is introduced into the resin passage of the nozzle unit connected to one side, and the other is introduced into the resin passage of the injection head through the resin passage of the runner block, and the gold is generated by the advance of the moving table. The product is molded by being injected into the mold from the nozzle attached to the tip of the nozzle unit that contacts the mold inlet and the nozzle of the injection head.

Next, another aspect of the present invention is a second injection unit that has one injection head connected through a first runner block and a second injection unit connected through a second runner block to one injection head. In order to solve the above-mentioned problems in the axial injection molding machine, a biaxial injection molding machine having the following structure is provided.

In a state where the relative positions of the first injection unit and the second injection unit and the injection head arranged on the movable table are maintained, the resin of the injection head is used instead of the first runner block and the second runner block. The structure is such that the first nozzle unit and the second nozzle unit each having a passage switching means and having a single nozzle are assembled, and the resin passage communicating with both injection units is switched to the tip end portion of both nozzle units or the injection head side. The twin-screw injection molding machine has a structure that enables dual-use molding (two-layer molding), two-color molding, and single molding (multifunction).

When the twin-screw injection molding machine having this structure is used, both runner blocks are replaced with a first nozzle unit and a second nozzle unit having a resin passage switching means, and the resin passages of both nozzle units are on the injection head side. The resin that is plasticized in the injection unit by being communicated with the resin passage of is introduced into the resin passage of the injection head through the resin passage of each nozzle unit, and by opening and closing the valve of the injection head, The product is molded by being injected into the mold from a nozzle that abuts the mold inlet portion from the forward movement.

Further, by blocking the resin passages of both nozzle units and the resin passage of the injection head, the resin plasticized in both injection molding units is introduced into the resin passages of the respective nozzle units, and the moving base is moved. Is advanced, the product is molded by being injected into the mold from the nozzle of the nozzle unit that comes into contact with the mold inlet portion.

In this twin-screw injection molding machine, a nozzle unit equipped with a resin passage switching means for the injection head and having a single nozzle is connected to one of the injection units, and the other injection unit is connected by a runner block. With the structure, the resin passage switching means on the nozzle unit side switches the resin passage communicating with the injection unit to the tip end portion of the nozzle unit or the injection head side, so that sandwich molding (two-layer molding), two-color molding, or single molding can be performed. It may be configured so that it can be used in combination (multifunctional).

In such a multi-functional type, by replacing with a nozzle unit provided with a resin passage switching means on either side of both runner blocks,
The resin plasticized in the injection unit communicating with the runner block is introduced into the resin passage of the injection head, and the resin plasticized in the injection unit communicating with the nozzle unit is switched to the resin passage of the injection head or the nozzle unit. The product is molded by being injected into the mold from the nozzle of the injection head or nozzle unit which is introduced to the tip side of the mold and abuts on the mold entrance portion as the moving table advances.

In any of the twin-screw injection molding machines according to the present invention described above, a heat insulating material is sandwiched between the connecting portions of the nozzle unit (two types) and the injection head to heat the nozzle unit and the injection head at different heating temperatures. It is preferable to be able to set and adjust independently. When the structure in which the heat insulating material is provided in the connecting portion between the nozzle unit and the injection head in this way, when the plasticized resin does not flow to the nozzle unit and the injection head side, the heating temperature is lowered and the resin remaining in the resin passage Is prevented from deteriorating.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a twin-screw injection molding machine according to the present invention will be specifically described with reference to the embodiments shown in FIGS. In the following embodiments, the same components as those of the conventional device shown in FIG. 5 are designated by the same reference numerals for simplification of description.

(First Embodiment) First, a biaxial injection molding machine according to the first embodiment shown in FIG. 1 will be described.
In this embodiment, the first runner block 6 and the second runner block 7 connected to the first injection unit 3 and the second injection unit 4 in FIG. 5 are replaced with the first nozzle unit 8 and the second injection unit 9 in FIG. By attaching / detaching / removing, sandwich molding and two-color molding can be performed. The sandwich molding is similar to the conventional example shown in FIG. 5, and the description of the structure and operation is omitted.

In the case of two-color molding, the first runner block 6 and the second runner block 7 in FIG. 5 are removed from the connecting portions of the injection units 3 and 4 and the injection head 5, and as shown in FIG. The first nozzle unit 8 and the second nozzle unit 9 are assembled and replaced.

Both nozzle units 8 and 9 are composed of nozzle blocks 20 and 21 and nozzles 22 and 23, and resin passages 20a and 21a communicating with the resin passages 11a and 12a of both injection units are provided inside the nozzle blocks 20 and 21. The nozzles 22 and 23 are screwed on the tip side.

Incidentally, resin passages 22a and 23a are provided at the axial centers of the nozzles 22 and 23, and the nozzle block 2
0 and 21 resin passages 20a and 21a are connected. Further, a flange portion (not shown) is provided at a connecting portion between the nozzle units 8 and 9 and the injection head 5, and the resin passages 15a and 15b of the injection head 5 are cut off, and a heat insulating material 24 is provided at the connecting portion. It is a sandwiched structure.

After removing both runner blocks 6 and 7 shown in FIG. 5, both nozzle units 8 and 9 as shown in FIG.
In the assembled state, the resin plasticized by the screws 13 and 14 of both injection units 3 and 4 is discharged from the respective resin passages 11a and 12a to both nozzle units 8 and
9 are introduced into the resin passages 20a, 21a, and the nozzles 22,
23 through the resin passages 22a and 23a.
The product is molded by being injected into the mold from the injection ports 22b and 23b of 23.

Although the injection head 5 does not operate in this state, the plasticized resin remaining in the injection head 5 in the previous step is kept at a temperature lower than the molding temperature and maintained without deterioration. Further, the heat from the nozzle units 8 and 9 is blocked by the heat insulating material 24 and the injection head 5 is not heated.

(Second Embodiment) Next, a biaxial injection molding machine according to a second embodiment shown in FIG. 2 will be described.
FIG. 2 is a top cross-sectional view showing the nozzle mechanism in this embodiment, and the difference from the first embodiment will be described.

In this embodiment, the first runner block 6 or the second runner block 7 connected to the first injection unit 3 or the second injection unit 4 shown in FIG. By detaching and replacing either the nozzle unit 8 or the second nozzle unit 9, sandwich molding and two-color molding can be performed.

In the case of two-color molding, as shown in FIG. 2, the first runner block 6 connected to the first injection unit 3 and the injection head 5 is removed and the first nozzle unit 8 is assembled and replaced. In this state, the resin plasticized by the screw 13 of the first injection unit 3 passes from the resin passage 11a to the resin passage 20 of the first nozzle unit 8.
a to 22a.

The resin plasticized by the screw 14 of the second injection unit 4 is introduced from the resin passage 12a into the outer resin passage 19 of the injection head 5 through the resin passage 7a of the second runner block 7. These plasticized resins come into contact with the mold inlet part by the advancement of a moving table (not shown), and the injection ports 22b and 16b of both nozzles 22 and 16 are made.
The product is molded by being injected into the mold.

Further, instead of detaching and replacing the first nozzle unit 8 and the first runner block 6 connected to the first injection unit 3 and the injection head 5 of FIG. 5 described above, as shown in FIG. The second runner block 7 that connects the second injection unit 4 of FIG. 5 to the injection head 5 can also be attached / detached / replaced with the first nozzle unit 9 of FIG. 1, and the assembled state is the case of FIG. The description is omitted because it is almost symmetrical.

(Third Embodiment) Next, a biaxial injection molding machine according to a third embodiment shown in FIG. 3 will be described. In this embodiment, the first runner block 6 and the second runner block 7 in FIG.
The biaxial injection molding machine is equipped with the first and second nozzle units 32. In FIG. 3, the first injection unit 3, the second injection unit 4, and the injection head 5 have the same structure and arrangement as those of the first embodiment, and therefore their explanations are omitted.

The first nozzle unit 31 is composed of a nozzle block 33 and a nozzle 22, and the nozzle block 3
Inside the 3, resin passages 33a, 33b, 33c are provided in a T shape, and a hole 33d for inserting the resin passage switching means 35 is provided at the center where the resin passages intersect. The switching means 35 is a cylinder and is T-shaped at the center in the longitudinal direction.
A V-shaped resin passage 35a is formed, inserted into the hole 33d, and rotatably mounted by a mounting means (not shown).

The second nozzle unit 32 is also composed of a nozzle block 34 and a nozzle 23, and resin passages 34a, 34b, 34c are provided in a T shape inside the nozzle block 34, and the center where the resin passages intersect. There is provided a hole 34d into which the resin passage switching means 36 is inserted.

The switching means 36 is cylindrical and has a T-shaped resin passage 36a formed at the center in the longitudinal direction. The switching means 36 is inserted into the hole 34d and is rotatably mounted by a mounting means (not shown). Further, both nozzle units 31, 32 are connected to each other by providing a flange portion (not shown) at the connecting portion with the injection head 5, and the heat insulating material 24 is sandwiched at the connecting portion with the injection head 5.

In the twin-screw injection molding machine assembled as shown in FIG. 3, the screw 13 of the first injection unit 3 is used.
The resin plasticized by is introduced from the resin passage 11a into the resin passage 33a of the first nozzle unit 31 and into the resin passage 33b of the switching means 35 (state shown in the drawing) into the resin passage 33b, and the resin of the nozzle 22 The product is molded through the resin passage 22a through the injection port 22b into the mold.

By rotating the switching means 35 to the right by 90 ° from the illustrated state, the resin passage 35a connects 33a and 33c, and the resin passage 33b is blocked. The plasticized resin is introduced from the resin passage 33c into the inner resin passage 19 'through the resin passage 15a of the injection head 5, and is injected into the mold from the injection port 16b of the nozzle 16 to mold the product.

The resin plasticized by the screw 14 of the second injection unit 4 passes through the resin passage 12a, the resin passage 34a of the second nozzle unit 32, and the resin passage 36a of the switching means 36 (state shown). Is introduced into the resin passage 34b through the resin passage 23a of the nozzle 23 and injected into the mold through the injection port 23b to form a product.

By rotating the switching means 36 to the left by 90 ° from the illustrated state, the resin passage 36a communicates with 34a and 34c and the resin passage 34b is blocked. The plasticized resin is introduced from the resin passage 34c into the outer resin passage 19 through the resin passage 15b of the injection head 5 and is injected into the mold through the injection port 16b of the nozzle 16 to form a product.

(Fourth Embodiment) Next, a biaxial injection molding machine according to a fourth embodiment shown in FIG. 4 will be described.
In this embodiment, the first nozzle unit 31 or the second nozzle unit 32 in the third embodiment is attached to either one side of the injection units 3 and 4, and the second injection unit is attached to the other side of the injection unit. The biaxial injection molding machine is equipped with the runner block 7 or the first runner block 6.

FIG. 4 shows a state in which the first nozzle unit 31 is mounted on the first injection unit 3 side and the second runner block 7 is mounted on the second injection unit 4 side, which is symmetrical to this. The second nozzle unit 32 is provided on the second injection unit 4 side, and the first runner block 6 is provided on the first injection unit 3 side.
It is also possible to attach.

The first injection unit 3, the second injection unit 4, the injection head 5, the first nozzle unit 31, and the second nozzle unit 32 are the third embodiment, and the first runner block 6 and the second runner block 7 are the same. Since the structure (arrangement) and operation are the same as those of the first embodiment, description thereof will be omitted.

[0049]

As described above, according to the twin-screw injection molding machine of the present invention, two sets of the injection unit and one injection head mounted and fixed on the moving base of the conventional twin-screw injection molding machine are provided. The structure is such that two sets of the injection unit and one injection head are connected while the related positions are held, and the runner block and the nozzle unit can be attached / detached / replaced (claims 1 and 2). By combining them, sandwich molding (two-layer molding), two-color molding, and single molding (multifunctional) are possible.

Further, according to the present invention, in place of the runner block, the structure for assembling the nozzle unit equipped with the resin passage switching means and provided with the single nozzle (claims 3 and 4), the resin passage by the switching means is used. By switching, sandwich molding (two-layer molding), two-color molding, and single molding (multifunctional) are possible.

Further, according to the present invention, in which the heat insulating material is sandwiched between the runner block or the connecting portion between the nozzle unit and the injection head, the heating temperatures of the nozzle unit and the injection head are independently set and adjusted. As a result, the unused injection head can be kept at a temperature lower than the molding temperature and the deterioration of the resin can be prevented.

As described above, in the twin-screw injection molding machine according to the present invention, the number of parts to be detached / replaced for multi-functionality is reduced and the weight is reduced. It became unnecessary to use it and was able to improve safety.

[Brief description of the drawings]

FIG. 1 is a top cross-sectional view showing a nozzle mechanism in a biaxial injection molding machine according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional top view showing a nozzle mechanism in a biaxial injection molding machine according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional top view showing a nozzle mechanism in a twin-screw injection molding machine according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional top view showing a nozzle mechanism in a biaxial injection molding machine according to a fourth embodiment of the present invention.

FIG. 5 is a top sectional view showing a nozzle mechanism in a conventional twin-screw injection molding machine.

[Explanation of symbols]

 3 1st injection unit 4 2nd injection unit 5 Injection head 6 1st runner block 7 2nd runner block 8,31 1st nozzle unit 9,32 2nd nozzle unit 11,12 head 13,14 Screw 19 Outer resin passage 19 'Inner resin passage 22,23 Nozzle 24 Heat insulating material 20,21,33,34 Nozzle block 35,36 Switching means

Front Page Continuation (72) Kenichi Terao Inventor Kenichi Terao 1 at 60 Kutane, Iwatsuka-cho, Nakamura-ku, Nagoya

Claims (5)

[Claims] 1. A twin-screw injection molding machine having a first injection unit connected via a first runner block and a second injection unit connected via a second runner block to one injection head. The first runner block communicating the resin passages of both the injection units and the injection heads in a state where the relative positions of the first injection unit and the second injection unit arranged on the table and the injection head are held. And sandwich molding (two-layer molding) by shutting off the resin passage between the second runner block and the injection head and attaching / detaching and replacing the first nozzle unit and the second nozzle unit having a single nozzle and the runner block. A twin-screw injection molding machine characterized by enabling dual-color molding and single molding (multi-function). 2. Sandwich molding (two-layer molding), two-color molding by attaching / detaching / replacing either one of the runner blocks and the nozzle unit of the two runner blocks connecting the both injection units and the injection head. The twin-screw injection molding machine according to claim 1, which can be used for both molding and single molding (multifunctional). 3. A twin-screw injection molding machine having a first injection unit connected via a first runner block and a second injection unit connected via a second runner block to one injection head. With the relative positions of the first injection unit and the second injection unit arranged on a table and the injection head being maintained, the resin passages of the both injection units and the injection head are connected to the first runner block and the first runner block. In place of the two-runner block, a structure in which a first nozzle unit and a second nozzle unit having a resin passage switching means for the same injection head and having a single nozzle is assembled, and a resin passage communicating with both the injection units is formed in the nozzle. By switching to the tip of the unit or the injection head side, sandwich molding (two-layer molding), two-color molding, single molding A twin-screw injection molding machine characterized in that it can be used for multiple purposes (multi-function). 4. The nozzle unit is connected to one of the injection units, and the other injection unit has a connection structure by the runner block, and is connected to the injection unit by a resin passage switching unit on the nozzle unit side. Connect the communicating resin passage to the tip of the nozzle unit,
4. The twin-screw injection molding machine according to claim 3, wherein sandwich molding (two-layer molding), two-color molding, and single molding can be combined by switching to the injection head side. 5. The heating temperature of the nozzle unit and the injection head can be independently set and adjusted by sandwiching a heat insulating material in the connecting portion between the nozzle unit and the injection head. The twin-screw injection molding machine described in any one of the above.