JPH0729295B2 - Four-screw extruder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruder for feeding a highly viscous material such as rubber or plastic to a preforming machine such as a pellet molding machine or a sheet molding machine.

[0002]

2. Description of the Related Art Parallel twin-screw extruders and conical twin-screw extruders are well known as conventional extruders. The parallel twin-screw extruder has a small material input port, so the kneader (kneader) is used.
It is necessary to cut the material kneaded in step 1 into small pieces, and then feed the material into the extruder. Further, if the extrusion pressure is increased, the axial length of the rotor becomes long, which is a drawback.

On the other hand, in the conical twin-screw extruder, the material feeding port can be easily made large, so that the material kneaded by the kneader can be fed as it is, and in comparison with that, the cross-sectional area of the extrusion port can be increased. Has a merit that a large extrusion pressure can be obtained without over kneading the material.
However, on the other hand, the axial adjustment of the rotor shaft sensitively affects the depth of engagement between the two-axis rotor and the gap between the rotor and the container, so it is necessary to pay sufficient attention to the adjustment work during assembly. It was

In any of the above-mentioned parallel biaxial type and conical biaxial type, since the rotor shaft is usually a cantilever support on the root side and the rotor tip is a free end, the internal pressure of the material is When the number of rotors increases, the tips of the rotors spread apart from each other, and as a result, it is necessary to provide a gap that anticipates that in order to prevent the rotor tips and the inner wall of the container from getting in contact with each other. There was a problem that there are many invalid spaces that do not work on the.

[0005]

Therefore, the present invention has a large input port through which the material kneaded by the kneader can be input as it is, and moreover, the axial adjustment of the rotor is easier than that of the conical twin-screw extruder. Therefore, it is an object of the present invention to provide a new four-screw extruder in which the tip of the rotor does not expand outward despite the increase in the internal pressure of the material, and therefore the gap between the rotor outer circumference and the inner wall of the container can be kept small.

[0006]

The four-screw extruder of the present invention comprises:
A first rotor having a root portion supported by a bearing, a first screw forming an extrusion adjusting portion formed at a tip portion, and a first blade formed at a central portion for introducing a charging material;
A second rotor having a root portion supported by a bearing, a second screw forming an extrusion adjusting portion together with the first screw formed at a tip portion, and a second blade formed at a central portion for introducing a charging material; A third rotor having a third blade formed outside the first rotor and having a root portion supported by a bearing to cooperate with the first screw to introduce an input material; A fourth rotor on the outer side of the rotor, a root portion of which is supported by a bearing and in which a fourth blade is formed to cooperate with the second screw to introduce a charging material; and the first, second, and third rotors. And driving means for rotationally driving the fourth rotor in a different direction from those adjacent to each other, a material charging port provided above the first, second, third and fourth blades, and the extrusion adjustment. Material provided at the rear of the section It characterized by having an outlet.

[0007]

As shown in FIG. 2, the high-viscosity material charged from the charging port is discharged from between the first rotor 1 and the third rotor 3 and between the second rotor 2 and the fourth rotor 4. It is introduced into the container. Therefore, the first rotor 1 and the second rotor 2 receive a force in a mutually attracting direction due to the internal pressure of the material charged in the blade forming portion in the central portion, and the force is expanded to the tip portion. However, in the extrusion adjusting portions at the tips of the first and second rotors, the internal pressures of the materials between the two screws receive forces in directions in which they separate from each other. As a result, the tip end portions of the first rotor 1 and the second rotor 2 cancel out the attractive force and the separating force, so that they do not distort significantly compared to when there is no load.

In particular, if it is designed so that the attraction of the central portions of the first and second rotors directly below the material inlet is greater than the forces of the tip portions to separate from each other, no load is applied. The tip does not separate from the outside as compared with the time, and the size of the inner wall of the container of the extrusion adjuster can be manufactured without considering the outward spread of the rotor tip. By the way, even if the tip of the rotor receives a bending force inward, the rotation vectors of the contact portions of the first and second screws are in the same direction, so there is no problem even if they abut each other.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a plan view of a container of an embodiment of the present invention cut away, FIG. 2 shows a sectional view taken along line AB of FIG. 1, and FIG.
FIG.

The first rotor 1 and the second rotor 2 are parallel inner biaxial rotors of four-axis rotors which are adjacent to each other, and their roots are supported by bearings 5, 6 and 7, 8. A first blade 9 and a second blade 10 which rotate in mutually different directions are formed in the central portion, and the first screw 11 and the second screw 11 which mesh with each other at the tip end portion thereof to form an extrusion adjusting portion Screw 12 is formed. Third
Rotor 3 is adjacent to the outside of the first rotor 1 and its root part is supported by bearings 13 and 14 and cooperates with the first blade 9 to introduce the material into the container through the inlet. 15 is formed. The fourth rotor 4 is adjacent to the outer side of the second rotor 2 and its root is supported by bearings 16 and 17, and cooperates with the second blade 10 to introduce the material into the container through the inlet. Blade 18 is formed. The roots of the rotors 1, 2, 3, 4 are gears 19, 2
The rotors 0, 21, and 22 are engaged with each other, and are rotationally driven in different directions from the rotors adjacent to each other. One axis of the four-axis rotor, for example, the root portion of the second rotor 2 is engaged with a drive mechanism (not shown) such as a motor and a speed reducer. The container that encloses these four-axis rotors is composed of a fixed container 23 that supports the bearing group of the root part and movable containers 24 and 25 that enclose the central portion and the tip of the rotor shaft, and the movable containers 24 and 25 are slid horizontally if necessary. The rotor and the inner surface of the container can be cleaned by the dynamic displacement. In addition, above the container 24, that is, the first, second, third and fourth blades 9, 10, 1
A material inlet 26 is provided above the containers 5 and 18, and the container 2
5 tip, that is, the first and second screws 11 and 12
A material extrusion port 27 is provided at the tip of the. Container 24
The cross-sectional shape of the tip is a shape in which the left and right ends are semicircular and a rectangle is connected between them so as to accommodate the horizontally arranged four-axis rotors 1, 2, 3, and 4. The cross-sectional shape of the portion of the container 25 that constitutes the extrusion adjusting portion is a parallel biaxial cylinder type that circumscribes the first and second screws 11 and 12 that are horizontally arranged. If necessary, a water passage may be provided inside each of the rotor shafts 1, 2, 3, 4 to allow cooling water to pass therethrough, or a jacket may be provided at the outer circumference of the containers 24 and 25 to allow passage of refrigerant.

[0011]

According to the present invention, since the material feeding port is provided on the side-by-side four-axis rotor, it becomes easier to provide a much larger feeding port than the conventional one, and the large kneader is provided. This makes it possible to accept even kneaded materials as they are.

Also, the charged materials are the first rotor and the third rotor.
Is introduced into the container from between the rotors, and between the second rotor and the fourth rotor, and the internal pressure at the introduction portion increases,
On the other hand, the internal pressure between the first rotor and the second rotor is low, and therefore, the first rotor and the second rotor receive a force in the direction in which the axial distance is shortened. It does not spread despite the increase. Therefore, the gap between the ridges of the rotating rotors 1 and 2 and the inner surface of the container 25 can be kept small, and the extrusion amount can be controlled accurately. In addition, since a force is applied in a direction in which the axial distance between the first rotor and the second rotor is shortened, the pushing screw 1 at the tips of both rotors is
Although the screws 1 and 12 may come into contact with each other, the rotation vectors of the contact portions of both screws are in the same direction and the peripheral velocities are almost the same, so that they are intimately meshed with each other and do not mess up.

[Brief description of drawings]

FIG. 1 is a cutaway plan view of a container according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line AB of FIG.

FIG. 3 is a sectional view taken along line C-D in FIG. 1.

[Explanation of symbols]

 1 ... 1st rotor 2 ... 2nd rotor 3 ... 3rd rotor 4 ... 4th rotor 9 ... 1st blade 10 ... 2nd blade 11 ... 1st screw 12 ... 2nd screw 15 ... 3rd blade 18 ... 4th blade 19 ... Gear 20 ...・ Gear 21 ・ ・ ・ ・ Gear 22 ・ ・ ・ ・ Gear 23, 24, 25 ・ ・ ・ ・ Container 26 ・ ・ ・ ・ Material input port 27 ・ ・ ・ ・ Material extrusion port

Claims (1)

[Claims] 1. A first rotor having a root portion supported by a bearing, a first screw forming an extrusion adjusting portion formed at a tip portion, and a first blade formed at a central portion for introducing a charging material; A second part of which the root part is supported by a bearing and which constitutes an extrusion adjusting part at the tip part together with the first screw.
A second rotor having a second blade formed in the center thereof to introduce a charging material into the central portion, and the first screw having a root portion supported by a bearing outside the first rotor, A third rotor having a third blade that cooperates to introduce the input material, and a second rotor that is outside the second rotor and has a root portion supported by a bearing.
Rotate in a different direction from the fourth rotor formed with the fourth blade for introducing the input material in cooperation with the first screw and the first, second, third and fourth rotors adjacent to each other. A four-screw extruder having driving means for driving, a material input port provided above the first, second, third and fourth blades, and a material discharge port provided behind the extrusion adjusting section. .