JP2006247917A - Extrusion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion apparatus capable of suppressing fluctuations in a discharge amount caused by pressure fluctuations and capable of suppressing the scaling-up of its leading end part. <P>SOLUTION: The extrusion apparatus comprises an extruder 2 having a screw 5 for kneading the material charged from a hopper 4 to extrude it, the gear pump 1 provided to the leading end part of the extruder 2, the sun gear 10 provided to the gear pump 1 and rotationally driven in a state that the screw 5 coincides with the axis X of a rotary shaft, and the planetary gear provided to the gear pump 1 to be rotated so as to follow the sun gear 10, and further comprises a first motor 17 for driving the screw 5 and a second motor 14 for driving the sun gear 10. The drive shaft 13 for connecting the sun gear 10 and the second motor 14 is provided in the screw 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an extruder having a screw for kneading and extruding a material charged from a hopper, a gear pump provided at the tip of the extruder, a gear pump, and the screw and the rotational axis coincide with each other. The present invention relates to an extrusion apparatus provided with a main drive element that is rotationally driven in the above state and a sub-drive element that is provided in the gear pump and is rotated by being driven by the main drive element.

  As such an extruding apparatus, for example, an extruding apparatus that extrudes a strip rubber for molding a tire is known (Patent Documents 1 and 2 below). A strip rubber extrusion device disclosed in the following Patent Document 1 includes a hopper for charging a rubber material, an extruder having a screw for kneading the charged rubber material, a gear pump provided on the front end side of the extruder, and a gear pump. And a molding base provided on the rubber extrusion side. By providing the gear pump, the rubber can be further kneaded and measured, so that the amount of rubber extruded from the molding die can be accurately controlled.

  In the case of an extrusion apparatus having this configuration, the rotational axis of the screw and the rotational axis of the gear pump gear are orthogonal to each other and are driven by separate drive systems. A drive motor for rotationally driving the screw is disposed on the rear end side of the screw, and a drive motor for rotationally driving the gear pump is disposed in the vicinity of the gear pump. In addition, by providing separate drive systems, the rotation of the screw can be controlled while keeping the rotation amount of the gear pump constant so that the discharge amount becomes constant. For example, a pressure sensor is provided at the tip of the screw, and the number of rotations of the screw can be controlled based on the detection result of the pressure sensor.

  However, since it becomes necessary to arrange a drive motor in the vicinity of the gear pump, there arises a problem that the size of the tip of the extrusion device becomes large. When a tire is molded by continuously wrapping a strip rubber to be molded around a molding drum, if the size of the tip near the molding drum is increased, the constraint condition when molding is increased and the tire has a desired shape. It is possible that the tire cannot be molded. In addition, when performing multi-layer molding, a plurality of extrusion devices are used. However, when the size of the tip portion is large, there is a problem that the degree of freedom of arrangement of the extrusion devices becomes small.

On the other hand, Patent Document 2 discloses an extrusion device having a different structure even in an extrusion device using the same gear pump. This extrusion apparatus is conceptually shown in FIG. The gear pump 1 in the extrusion apparatus includes a carrier (main drive element) provided on the same drive shaft as the screw 5, a casing with an internal gear in which the main drive element is accommodated, the internal gear and the main drive element. And four planetary gears (sub drive elements) provided between the two. Although the principle of this gear pump 1 is different from that of Patent Document 1, it has a function of measuring and attempts to stabilize the discharge amount.
JP 2004-35838 A JP-T-2004-509787

  However, in the case of Patent Document 2, the carrier and the screw 5 are on the same drive shaft and are driven to rotate by the same drive motor 100. Therefore, the rotational speed of the screw 5 cannot be controlled separately from the carrier, and there arises a problem that the discharge amount also fluctuates when the pressure fluctuates at the tip of the screw 5. For example, the discharge amount fluctuates when the rubber material to be charged is cut for a moment or when rubber materials having different viscosities are continuously charged.

  This invention is made | formed in view of the said situation, The subject is providing the extrusion apparatus which can suppress the fluctuation | variation of the discharge amount by pressure fluctuation | variation, and can suppress the enlargement of an apparatus front-end | tip part.

In order to solve the above problems, the extrusion apparatus according to the present invention is
An extruder having a screw for kneading and extruding the material charged from the hopper;
A gear pump provided at the tip of the extruder;
A main drive element that is provided in a gear pump and is driven to rotate in a state where the screw and the rotation axis coincide with each other;
An extrusion apparatus provided with a sub-drive element provided in the gear pump and rotated by being driven by a main drive element,
A first motor for driving the screw;
A second motor for driving the main drive element;
A drive shaft for connecting the main drive element and the second motor is provided inside the screw.

  The operation and effect of the extrusion apparatus having this configuration will be described. This extrusion apparatus has an extruder having a screw for kneading and extruding the material, and a gear pump disposed at the tip of the extruder. The gear pump includes a main drive element and a sub drive element, and the main drive element and the screw are arranged in a state in which the rotation axes coincide with each other. However, since the first motor for driving the screw and the second motor for driving the main drive element are arranged separately, only the rotation speed of the screw is controlled while keeping the rotation speed of the main drive element constant. It becomes possible. Further, since the drive shaft for driving the main drive element is provided inside the screw, the main drive element and the second motor can be coupled without interfering with the arrangement of the screw. Therefore, it becomes possible to arrange the drive system for driving the main drive element of the gear pump not on the front end portion of the apparatus but on the rear side, and the enlargement of the front end portion can be suppressed. As a result, it is possible to provide an extrusion apparatus that can suppress fluctuations in the discharge amount due to pressure fluctuations and can suppress an increase in the size of the tip of the apparatus.

In the present invention, a pressure sensor provided at the tip of the screw,
It is preferable to include a screw control unit that controls the rotation of the first motor based on the detection result by the pressure sensor.

  By providing a pressure sensor at the tip of the screw, pressure fluctuations in this region can be detected. Based on the detection result of the pressure sensor, the rotational speed of the screw (first motor) can be controlled in a direction to suppress pressure fluctuation.

  Both the first motor and the second motor according to the present invention are preferably arranged on the rear end side of the screw. Thereby, the drive system of a screw and a gear pump can be arrange | positioned at the back of an apparatus, and the enlargement of a front-end | tip part can be suppressed.

  The second motor according to the present invention is preferably disposed on an extension line of the rotational axis of the screw, and the first motor is preferably disposed adjacent to the second motor.

  Since the second motor is disposed on the rotational axis of the screw and disposed on the rear end side of the screw, the drive system of the main drive element can be simplified. Further, by arranging the first motor and the second motor adjacent to each other, the motor can be efficiently arranged without generating a useless space.

  The main drive element according to the present invention is preferably a sun gear, and the auxiliary drive element is preferably a planetary gear meshing with the sun gear. By engaging the sun gear and the planetary gear, the gear teeth can be used to measure and extrude material.

  A preferred embodiment of an extrusion apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a cross-sectional configuration of a rubber extrusion device with a built-in gear pump.

  This rubber extrusion apparatus has a gear pump zone A and a kneading zone B functionally divided. The gear pump zone A is provided with a gear pump 1, and the kneading zone B is provided with an extruder 2. The extruder 2 includes a cylindrical barrel 3 and a hopper 4 disposed on the outer periphery thereof. From the hopper 4, a rubber material is charged by an appropriate method. As the rubber material, for example, general-purpose materials such as natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) can be used.

  A screw 5 for kneading the rubber material introduced from the hopper 4 is provided in the barrel 3 and is driven to rotate about the rotation axis X. While the rubber material is compressed and kneaded between the screw blade 5a formed on the outer periphery of the screw 5 and the inner wall surface 3a, it is pushed forward.

  The gear pump 1 is disposed at the tip of the screw 5, and a sun gear 10 (corresponding to the main drive element) and four planetary gears 11 (corresponding to the sub drive elements) disposed on the outer periphery thereof are provided. . 2A and 2B are cross-sectional views of the gear pump 1 viewed from the front end side, where FIG. 2A is a cross-sectional view taken along the line CC, FIG. 2B is a cross-sectional view taken along the line DD, and FIG. The sun gear 10 is driven to rotate clockwise around the rotation axis X. The gear pump 1 is entirely formed in a casing 12, and the casing 12 is integrally coupled to the barrel 3.

  At a position closest to the screw 5, a supply space 12 a is formed in the casing 12 in the vicinity of a position where the sun gear 10 and the planetary gear 11 are engaged. The rubber material kneaded by the extruder 2 is first supplied to the supply space 12a. The size of the supply space 12a becomes smaller toward the tip side. As shown in (b), the size of the space is almost zero at the intermediate position in the feed direction. Then, further toward the front end side from the intermediate position, the discharge space 12b gradually appears, and as shown in (c), it becomes the largest space at the front end position in the length direction. In (a), the supply space 12 a is formed on the clockwise side of the planetary gear 11, while the discharge space 12 b is formed on the counterclockwise side of the planetary gear 11. Therefore, since the rubber material supplied from the extruder 2 goes from the supply space 12a to the discharge space 12b and passes through the gear teeth during that time, the rubber material is measured and the discharge amount is set accurately. Can do. Further, the sun gear 10 and the planetary gear 11 are constituted by helical gears, and the rubber material can be smoothly moved from the supply space 12a that is shifted in the circumferential direction to the discharge space 12b. The rubber material discharged from the gear pump 1 is extruded from a molding die (not shown).

  The structure of the gear pump 1 is not limited to that shown in FIG. For example, the number of planetary gears 11 and the rotation direction of the sun gear 10 can be appropriately changed. For example, a gear pump as disclosed in Patent Document 2 may be used.

  The sun gear 10 of the gear pump 1 is connected to a drive shaft 13 and is driven by a second motor 14 and a speed reduction mechanism 15 connected to the second motor 14. The drive shaft 13 has the same rotational axis X as that of the screw 5, but the drive shaft 13 and the screw 5 can be driven independently. The drive shaft 13 is disposed through a space formed inside the screw 5. Between the inner wall surface 5 b of the screw 5 and the drive shaft 13, two bearings 16 are provided along the direction of the rotational axis X, whereby the drive shaft 13 is supported in the internal space of the screw 5.

  On the other hand, the screw 5 is driven by a first motor 17 and a speed reduction mechanism 18 connected to the first motor 17. The first motor 17 and the second motor 14 are both disposed on the rear side of the screw 5 and are disposed adjacent to each other. With this arrangement configuration, it is possible to suppress an increase in size on the tip side of the extrusion device. The rotational axis Y of the first motor 17 is set so as to be parallel to the rotational axis X of the second motor 14, thereby realizing a spatially wasteful arrangement configuration.

  The first motor 17 is driven by the first drive circuit 20, and the second motor 14 is driven by the second drive circuit 21. Moreover, the pressure sensor 22 is provided in the front-end | tip part of the screw 5, and the pressure value in this position is monitored. The pressure detection unit 23 detects a pressure value based on the signal detected by the pressure sensor 22. The control unit 24 (corresponding to the screw control unit) gives drive command signals to the first and second drive circuits 20 and 21, and in particular controls the number of rotations of the screw 5 based on the detection result by the pressure sensor 22. . That is, the rotational speed of the screw 5 is controlled so that the discharge amount does not fluctuate when, for example, the rubber material thrown from the hopper 4 is momentarily cut or a rubber material having a different viscosity is thrown. By increasing the rotation speed, it is possible to control the discharge amount in the increasing direction.

  By using the rubber extrusion device according to the present invention, for example, it is possible to manufacture a tire having a desired cross-sectional shape by winding a strip rubber around a molding drum. In this case, since the size of the tip portion can be reduced, the degree of freedom in the arrangement configuration of the entire equipment can be increased.

  FIG. 3 is a diagram illustrating a configuration example when the screw 5 and the gear pump 1 are driven by the common motor 100. In the case of this configuration, the rotation speed of the gear pump and the rotation speed of the screw 5 must always be the same. Therefore, when the pressure fluctuation at the tip of the screw 5 occurs, the rotation speed of the screw 5 is controlled to change the pressure fluctuation. It cannot be suppressed. On the other hand, in the case of this invention, since it can drive separately, the rotation speed of the screw 5 can be controlled independently.

  In addition, two or three or more rubber extrusion devices can be used for multi-layer extrusion, but since the size of the tip of the device is suppressed, a plurality of rubber extrusion devices are placed close to each other. Arrangement is also possible, and the degree of freedom in arrangement can be increased. In addition, since a gear pump is built in, precise shape control can be performed.

<Another embodiment>
The extrusion apparatus according to the present invention can be applied not only to rubber materials but also to resin materials.

Schematic diagram showing the configuration of rubber extrusion equipment Diagram showing the cross-sectional configuration of the gear pump Schematic diagram showing the configuration of a rubber extrusion device according to the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gear pump 2 Extruder 3 Barrel 4 Hopper 5 Screw 10 Sun gear 11 Planetary gear 13 Drive shaft 14 Second motor 17 First motor 22 Pressure sensor 23 Pressure detection part 24 Control part X Rotation axis

Claims (5)

An extruder having a screw for kneading and extruding the material charged from the hopper;
A gear pump provided at the tip of the extruder;
A main drive element that is provided in a gear pump and is driven to rotate in a state where the screw and the rotation axis coincide with each other;
An extrusion apparatus provided with a sub-drive element provided in the gear pump and rotated by being driven by a main drive element,
A first motor for driving the screw;
A second motor for driving the main drive element;
An extrusion apparatus characterized in that a drive shaft for connecting the main drive element and the second motor is provided inside the screw. A pressure sensor provided at the tip of the screw;
The extrusion apparatus according to claim 1, further comprising: a screw control unit that controls rotation of the first motor based on a detection result by the pressure sensor.   The extrusion apparatus according to claim 1 or 2, wherein both the first motor and the second motor are arranged on the rear end side of the screw.   The extrusion apparatus according to claim 3, wherein the second motor is disposed on an extension line of the rotational axis of the screw, and the first motor is disposed adjacent to the second motor. The extrusion device according to any one of claims 1 to 4, wherein the main drive element is a sun gear, and the sub drive element is a planetary gear meshing with the sun gear.

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