JP2000225641A - Extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extruder with reliable machine protection by quickly detecting overload during the operation followed by controlling of the machine. SOLUTION: This extruder 100 detects distortional displacement of a screw axis 32 during the operation to control a controller 200. The distodional displacement of a screw axis 32 is detected by combining a driving member revolution sensor 111 and a screw axis revolution sensor 112, or by combining the driving member revolution sensor 111 and a screw axis revolution sensor, and by detecting the revolution differential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruder, and more particularly, to an extruder, which has mechanical properties so that a material can be sufficiently kneaded while maintaining a sufficient extruding speed, and which has a screw during kneading. The present invention relates to an extruder provided with overload protection means for quickly detecting the generated overload.

[0002]

2. Description of the Related Art Conventionally, an extruder has been known in which a thermoplastic resin is heated and melted in a cylinder, kneaded with a screw, extruded, and a molded product is continuously obtained.

FIG. 7 is a configuration diagram showing a conventional extruder. In this extruder 10, a screw 30 is rotatably disposed in a cylindrical cylinder 20 in which a heater or a heat medium is circulated and heated. A die can be attached to the opening on the tip side of the cylinder 20. Screw 30
Is directly connected to the screw drive shaft 31 and is connected via a gear box 52 to a transmission shaft 51 which is connected to the motor shaft 42 of the drive motor 41 via a coupling 70.
Therefore, the driving force is transmitted to the screw 30 from the driving motor 41 via the gears 53 and 54 of the gear box 52, and the screw 30 is driven and rotated.

In the gear box 52, a drive gear 53 fixed to the transmission shaft 51 and a transmission gear 54 fixed to the screw drive shaft 31 mesh with each other. On the material supply side of the screw 30, a solid resin raw material is supplied into the cylinder 20 by a feeder 62 that is rotated by a driving force of a feeder motor 61. While the solid thermoplastic resin supplied into the cylinder 20 by the feeder 62 is conveyed through the cylinder 20 from the material supply side of the screw 30 to the distal end with the rotation of the screw 30, the cylinder 20 and the screw 30 Are melted and kneaded in cooperation with each other, and are continuously extruded from the opening at the tip of the cylinder 20. The extruded resin continuously passes through a die (not shown) and is formed into molded products having various cross-sectional shapes.

[0005]

In such an extruder, how efficiently the rotating screw melts the material,
The quality of the extruder is determined by whether it can be transported to the die while kneading. In particular, in an extruder capable of obtaining a high throughput, it is required that the screw be rotated at a high speed and that the driving torque of the screw be large.

However, in the conventional extruder, even if an attempt is made to reduce the molding cost by increasing the extrusion speed, high-speed operation cannot be performed due to insufficient mechanical properties, and the material is sufficiently melted and kneaded to obtain high-quality molding. In order to obtain a product, the extrusion speed must be reduced by reducing the rotation speed of the screw, and there is a problem that the molding cost increases.

Further, in such an extruder, the friction between the screw 30 and the cylinder 20 rapidly increases due to foreign matter mixing, excessive supply of material, operating conditions, and the like during operation, and an excessive torque is generated. May cause equipment destruction. Therefore, the extruder is provided with a protection means against such an overload.

As a conventional overload protection, for example, a method is provided in which a mechanical slip clutch is provided between the motor shaft 42 of the drive motor 41 and the transmission shaft 51, and when the torque is exceeded, the clutch is slipped to a set torque or less. is there. Further, a method of stopping the drive motor 41 by detecting an overload current, a method of coupling the gearbox 52 and the drive motor 41
There are known a method in which a strain gauge is installed at 0 and the drive motor 41 is stopped by the occurrence of distortion, a method in which a shear pin is provided in the coupling 70 between the gear box 52 and the drive motor 41, and the like.

However, in the conventional overload protection, an overload current of the drive motor is detected, or a sensor or a mechanical torque cut-off means is provided immediately before the drive motor to detect a load near the drive motor. Therefore, there is a detection delay from the occurrence of an overload to the detection, and there is a problem that it is not sufficient for protection of a device, such as a screw or a gear box, which is operating at a high speed and which is far from the drive motor. Was.

[0010] The present invention has been made in view of the above problems, and kneads or mixes materials at a sufficient density while maintaining an extrusion speed at or above a certain level to form a high-quality molded product at low cost. It is an object of the present invention to provide an extruder capable of effectively protecting an apparatus by quickly detecting an overload generated in a screw during melting and kneading.

[0011]

According to one aspect of the present invention, there is provided an extruder comprising: a cylinder; a screw rotatably disposed in the cylinder; and a drive for rotating the screw. And a torsion detecting means for detecting a torsional displacement of a screw shaft of the screw when an overload occurs in the rotation of the screw, and a load on the screw based on an output of the torsion detecting means. And / or control means for issuing an alarm.

According to the invention having such a configuration, since the torsional displacement of the screw shaft caused by the overload is directly detected, there is no detection delay from the occurrence of the overload until the detection, and a prompt response is possible. Yes, it is possible to effectively protect devices that are far from the drive motor, such as screws and gearboxes.

The extrusion speed of the material, that is, the extrusion amount per unit time, is determined by the rotation speed of the screw, the torque T transmitted from the driving means, and the distance L between the axes of the screw.
(Which determines the volume in the cylinder). Therefore, as a result of the inventor's creative research, the design mechanical characteristics ML evaluated based on the theoretical torque T that can be transmitted from the driving means to the screw and the axial distance L of the screw are represented by ML = T / L. ^The extruder is designed so that the mechanical characteristics ML in the design are within the range of 27.5 ≦ ML ≦ 40, so that the best extrusion and mixing results can be obtained even for resins having different viscosities. Was found. This result was particularly good when the rotation speed of the screw was relatively high at 100 min ^-1 or more.

Therefore, based on this finding, the extruder according to claim 2 drives a cylinder, two screws rotatably and parallelly arranged in the cylinder, and two screws. In the extruder provided with a driving means for rotating, in the design of the extruder, the theoretical torque T transmitted to the screw by driving the driving means, and the distance L between the axes of the two screws. the mechanical properties ML expressed by T / L ^3, mechanical properties ML on this design, the torque T and the axial distance L on the theoretical to be either in the range of 27.5 ≦ ML ≦ 40 There is a set configuration. According to the invention having such a configuration, it is possible to provide an apparatus capable of satisfactorily kneading and mixing materials with two screws.

The extruder according to claim 3, in an extruder according to claim 2, the extrusion properties of the actual torque Td in the extruder operation when the EL = Td / L ^3, wherein Control means for controlling the driving of the driving means is provided so that the extrusion characteristic EL falls within the range of the designed mechanical characteristic ML. According to such a configuration, the actual torque Td of the driving means varies depending on the type of resin, operating conditions, and the like, but the actual torque Td always satisfies 27.5L ³ ≦ Td ≦ 40L ³ by the control means. By controlling as described above, the mechanical property ML on the design is set to 27.5 ≦ M
L can be maintained in the range of 40 or less, and the molded product can be extruded in the best condition always under stable conditions.

According to a fourth aspect of the present invention, there is provided the extruder according to the third aspect, wherein a torsion detecting means for detecting a torsional displacement of a screw shaft of the screw when a load acts on the rotation of the screw; When an overload occurs in the rotation of the screw, control means for controlling a load on the screw based on an output of the torsion detecting means and / or issuing an alarm is provided. According to the invention having such a configuration, it is possible to detect an overload generated in the screw and quickly respond while constantly extruding the molded article in the best condition, and to perform a quick response by using a drive motor such as a screw or a gear box. It is possible to effectively protect a device in a remote place.

According to a fifth aspect of the present invention, there is provided the extruder according to the first or fourth aspect, wherein the torsion detecting means detects a rotation speed of the screw shaft; A driving unit rotation speed sensor that detects the rotation speed of the transmission gear fixed to the transmission gear, and wherein the control unit determines a difference between the respective rotation speeds detected by the screw shaft rotation speed sensor and the driving unit rotation speed sensor. And performs a control and / or an alarm based on the

According to the invention having such a configuration, as a method for detecting the torsional displacement of the screw shaft, an overload is detected by detecting a difference between the rotation speed of the screw shaft and the rotation speed of the transmission gear driving the screw shaft. Since the overload is detected at a position close to the part where the error occurs, detection delay is small, quick response is possible, and the device can be effectively protected.

According to a sixth aspect of the present invention, in the extruder according to the first or fourth aspect, the torsion detecting means is provided in the cylinder and detects a rotational speed of the screw. And a drive unit rotation speed sensor that detects the rotation speed of the transmission gear fixed to the screw shaft, and wherein the control unit controls each rotation detected by the screw rotation speed sensor and the drive unit rotation speed sensor. The control and / or the alarm is performed based on the speed difference.

According to the invention having such a configuration, as a method of detecting the torsional displacement of the screw shaft, an overload is detected by detecting a difference between the rotation speed of the screw itself and the rotation speed of the transmission gear driving the screw. Since the overload is detected at the portion where the occurrence occurs, there is no delay in detection, prompt response is possible, and the device can be effectively protected.

The extruder according to claim 7 is the extruder according to claims 1 to 6
In the extruder according to any one of, the control means,
The supply amount of the resin raw material into the cylinder is controlled. According to the invention having such a configuration, by detecting the overload quickly, the supply of the raw material is controlled, and the overload can be eliminated.

The invention described in claim 8 is the first invention.
7. The extruder according to any one of the above-described items 6, wherein the control means controls the rotation speed of the screw while keeping the supply amount of the resin raw material into the cylinder constant. According to this configuration, by detecting the overload quickly,
The overload can be eliminated by controlling the rotation speed of the screw.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the extruder according to the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing a first embodiment of an extruder according to the present invention. The basic configuration of the extruder 100 is the same as the conventional extruder shown in FIG. That is, a cylindrical cylinder 2 in which a heater or a heating medium is circulated and heated.
The screw 30 is rotatably disposed in the center.
The opening on the distal end side of the cylinder 20 has a flange shape so that a die (not shown) can be mounted. The rotation speed of the screw 30 is changed by a driving force of a driving motor 41 as a driving unit via a gear box 52, and the screw 30 is driven to rotate. The driving force of the driving motor 41 is transmitted from the motor shaft 42 of the driving motor 41 to the transmission shaft 51 via the coupling 70, and from the transmission shaft 51, the driving gear 53 in the gear box 52 fixed to the transmission shaft 51. The power is transmitted to the screw drive shaft 31 fixed to the transmission gear 54 via a transmission gear 54 meshing with the driving gear 53.

The screw drive shaft 31 is
Shaft portion 30a except for the fin of the screw 30
And the screw drive shaft 3 directly connected to the shaft portion 30a.
1 constitutes the screw shaft 32. Screw 3
On the material supply side of No. 0, a solid resin raw material is supplied into the cylinder 20 by a feeder 62 which is rotated by a driving force of a feeder motor 61.

The solid thermoplastic resin supplied into the cylinder 20 by the feeder 62 is conveyed through the cylinder 20 from the material supply side of the screw 30 to the tip side with the rotation of the screw 30, and the solid thermoplastic resin is supplied to the cylinder 20. It is melted and kneaded by the cooperation of the screw 30 and is continuously extruded in a molten state from the opening at the tip of the cylinder 20. When a die (not shown) is mounted, the extruded resin continuously passes through the die to form extruded products having various cross-sectional shapes.

In such an extruder, the friction between the screw 30 and the cylinder 20 rapidly increases due to foreign matter mixing, excessive supply of material, operating conditions, and the like, resulting in excessive torque and destruction of the apparatus. There are cases. for that reason,
The extruder 100 of this embodiment is provided with an overload protection means capable of quickly detecting and responding to such an overload.

The overload protection means includes a screw shaft 32
The drive unit rotation speed sensor 111 detects the rotation speed of the transmission gear 54 fixed to the screw drive shaft 31, and the screw shaft rotation detects the rotation speed of the screw drive shaft 31 as torsion detection means for detecting the torsional displacement of the screw drive shaft 31. A speed sensor 112, a controller 200 as a control means for controlling the load on the screw 30 based on the output of these torsion detecting means and / or issuing an alarm, and an alarm 12 for issuing an alarm under the control of the controller 200
0 and so on.

The drive unit rotational speed sensor 111 is disposed in the gear box 52 and detects the rotational speed of the transmission gear 54 disposed in the gear box 52, so that it is not affected by oil, for example. A digital type such as a magnetic encoder can be used.
2 is also arranged in the gear box 52,
For example, a digital type using a magnetic encoder or the like can be used. Note that an optical encoder can also be used. As an analog type, a synchro utilizing an electromagnetic induction phenomenon between coils or a resolver can be used.

As shown in FIG. 2, the controller 200 includes a converter 210 for converting a pulse output or an AC voltage of the drive unit rotational speed sensor 111 and the screw shaft rotational speed sensor 112 into a DC voltage, respectively.
Comparator 2 for comparing the DC voltage output from 10
20, an alarm device 120 for receiving an output of the comparator 220 and issuing an alarm, a feeder motor 61, and a control unit 230 for controlling the drive motor 41.

If the friction between the screw 30 and the cylinder 20 becomes abnormally high due to foreign matter being mixed in or excessive supply of material inside the cylinder 20, the screw 30 whose rotation is suppressed by the friction with the cylinder 20 is removed. A large torsional force is applied to the screw shaft 32 by the transmission gear 54 that is forcibly rotated, and a torsional displacement occurs. Therefore, the transmission gear 54 and the screw drive shaft 3 to which the transmission gear 54 is fixed and which is directly connected to the screw 30.
1 is displaced. This displacement appears as a difference between the rotation speed of the transmission gear 54 and the rotation speed of the screw drive shaft 31.

Therefore, if the difference between the rotation speed of the transmission gear 54 detected by the drive unit rotation speed sensor 111 and the rotation speed of the screw drive shaft 31 detected by the screw shaft rotation speed sensor 112 is detected, the screw shaft 32 Can be detected. The difference between the rotation speeds is detected by the comparator 220 as a difference between the DC voltages, and the control unit 230 performs various controls based on the difference between the rotation speeds.

For the control by the control unit 230, for example, a difference between the rotational speeds at which the control is started is set in advance as a set value, and a difference between the rotational speeds indicating the maximum allowable torsional displacement is set as an upper limit value. Screw drive shaft 31 and transmission gear 5
When the rotation speed difference of No. 4 becomes equal to or greater than the set value, the control unit 230 issues an alarm from the alarm device 120, for example, to notify the operator that an overload has occurred. The operator takes necessary measures based on the warning.

The control unit 230 also reduces the rotation speed of the feeder motor 61 to reduce the amount of material supplied to the cylinder 20 or automatically drives the drive motor 41 while maintaining the supply amount constant. The rotation speed of the screw 30 is adjusted by raising and lowering the rotation speed of the screw 30 by a method set in advance, and the control of reducing the load on the screw 30 is performed. Further, when the difference between the rotation speeds exceeds the upper limit value, control for stopping the drive motor 41 is performed.

An example of such control by the control unit 230 will be described with reference to the flowchart of FIG. First,
In step 301, a difference between the rotation speeds output from the comparator 220 is detected. Next, in step 302, it is determined whether or not the difference between the rotation speeds exceeds a set value. If not, the operation of detecting the difference in rotation speed is continued. If it exceeds the set value, step 303
To determine whether the value exceeds the upper limit. If it exceeds the upper limit, the drive motor 41 is stopped at step 304 and the control is terminated.

On the other hand, if it does not exceed the upper limit, in step 305, a buzzer is first sounded to notify the operator that an overload has occurred. Also, in step 306,
The rotation of the feeder motor 61 is reduced to reduce the amount of raw material supplied to reduce the load. Further, in step 307, a difference in rotation speed after the reduction of the raw material supply amount is detected, and in step 308, it is determined whether the difference in rotation speed exceeds a set value. If so,
Returning to step 303, it is determined whether the value exceeds the upper limit value. If not, the warning by the buzzer and the adjustment of the feeder amount are continued. When the overload is eliminated by the adjustment of the feeder amount and the difference between the rotation speeds becomes smaller than the set value, the control is ended. If the overload also increases and exceeds the upper limit value due to the adjustment of the feeder amount, step 304 is executed.
To stop the drive motor 42.

According to the extruder 100 of the first embodiment, the transmission gear 5 for transmitting the rotation speed of the screw drive shaft 31 and the driving force fixed to the screw drive shaft 31 is used.
The rotational speed of the screw shaft 32 is detected as the rotational speed of the screw shaft 32. Therefore, in the conventional extruder, the load is detected on the side of the drive motor farthest from the point where the load is generated.
Since the overload occurring at 0 is detected by the displacement at the position closest to the portion where the overload has occurred, there is no delay in the detection from the occurrence of the overload to the detection, and quick control is possible. Yes, screw 30 and gear box 52
For example, a device remote from the drive motor 41 can be protected from overload.

Next, a second embodiment of the extruder of the present invention will be described with reference to FIG. The extruder according to the second embodiment differs from the first embodiment only in the position at which torsional displacement is detected. Therefore, the same components are denoted by the same reference numerals, and only different points will be described.

The extruder 101 has two rotation speed sensors. One is the same transmission gear 54 as in the first embodiment.
And a screw rotation speed sensor 113 provided in the cylinder 20. As the screw rotation speed sensor 113, for example, a viewing window formed of a transparent ceramic such as silicon oxide or aluminum oxide is provided on the cylinder 20 wall, and light is irradiated into the cylinder 20.
A configuration that detects reflection from the fins of the rotating screw 30 or a configuration that detects the top of the rotating screw 30 using an electromagnetic proximity sensor can be adopted.

The controller 200 is the same as that shown in FIG. 2. In the second embodiment, the controller 200 detects the difference between the rotation speed of the screw 30 and the rotation speed of the transmission gear 54 fixed to the screw drive shaft 31. The torsional displacement of the screw shaft 32 is set.

According to such a detection method, the torsional displacement of the screw shaft 32 is controlled by the screw 30 and the gear box 5.
Since the torsional displacement can be detected at the portion where the overload occurs directly by detecting the difference from the rotation speed of the transmission gear 54 in the second gear 2, the first
It is possible to detect overload more quickly than in the embodiment. Therefore, the device can be reliably protected against overload.

In the above description, the rotational speed difference is detected by the two rotational speed sensors to detect the torsional displacement of the screw shaft. For example, a metal wire strain gauge, a piezo element, etc. May be embedded to directly detect the torsion of the screw shaft.

The position of the sensor is not limited to the above embodiment. For example, the torsional displacement of the screw shaft 32 may be detected by a combination of the above-described screw shaft rotation speed sensor 112 and screw rotation speed sensor 113. .

Further, the extruder of the present invention is the same as a normal extruder except for the above-mentioned overload protection means, and is also applicable to a twin-screw extruder in which two screws are arranged in parallel in a cylinder. Applicable.

FIG. 5 shows a third embodiment in which the present invention is applied to a twin-screw extruder.
It is a lineblock diagram of an extruder concerning an embodiment. 5, the same components and members as those of the extruder of FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 5, two screws 30, 30 'are disposed in parallel in a cylinder 20' of an extruder 101 '. The rotation of the rotating shaft 42 caused by the driving of the drive motor 41
The transmission is transmitted to the transmission gear 54 'of the screw 30 via an intermediate gear (not shown). Therefore, in this embodiment, the screw 3
0, 30 'rotate in the same direction. Although not shown, the screws 30, 30 'may be configured to rotate in opposite directions.

As in the first and second embodiments, drive unit rotation speed sensors 111, 111 'for detecting the rotation speeds of the transmission gears 54, 54' fixed to the screw drive shafts 31, 31 ', respectively. And screw drive shafts 31, 3
Screw shaft rotation speed sensors 113 and 113 'for detecting the rotation speed 1' are provided.

From the transmission gears 54, 54 ', the screw 3
The theoretical torque T transmitted to 0, 30 '(hereinafter referred to as the theoretical torque T) can be obtained by detecting the rotational speed of the transmission gears 54, 54'. That is,
The control device 200 uses a known formula, T = 9.55H / n.
(H: motor output (W), n: transmission gears 54, 54 ')
By substituting the rotational speeds detected by the drive unit rotational speed sensors 111 and 111 'into the denominator n of the rotational speed (min ^-1 ), the theoretical torque T [N-m] can be calculated.

The extrusion rate of the material, that is, the extrusion rate per unit time, depends on the rotation speed of the screws 30, 30 ',
The theoretical torque T transmitted from the transmission gears 54, 54 'and the distance L between the shafts of the screws 30, 30' (this is
Determine the volume within 0 '). Therefore, the mechanical properties ML = T / L ³ [N-mm / mm in design]
³ ] is designed so that the value of 27.5 ≦ ML ≦ 40, and the extrusion characteristics E of the actual extruder 101 are set.
L is defined as EL = Td / L by the torque Td (torque Td detected in the actual extruder 101; hereinafter, referred to as actual torque Td) and the distance L between the shafts of the screws 30, 30 '.
Expressed as ^3, quality and the extrusion rate of the molded article and (extrusion speed) to verify the actual torque Td to be the best by changing the extrusion properties EL variously.

FIG. 6 shows the present invention using screws 30, 3
It is a graph which shows the relationship between the rotation speed of the screw 30,30 ', and the extrusion amount of material when extruding is performed using the extruder whose diameter of 0' is 92 mm. From the graph of FIG.
The rotation speed of the screw 30, 30 '(for example, rotation speed 1
It can be seen that even if the value of 30 min ^-1 ) is the same, when the value of the extrusion characteristic EL is changed, the extrusion amount also changes. As a result of examining the relationship between the rotation speeds of the screws 30, 30 'and the extrusion amount by changing the value of the extrusion characteristic EL variously, 27.5 ≦ EL ≦ 40
The best results were obtained within the range. That is, it was confirmed by verification that the best result could be obtained by controlling the driving of the driving means so that the extrusion characteristic EL in the actual extruder was within the range of the mechanical characteristic ML in design.
In addition, as shown in FIG.
Good results can be obtained even at high speeds where the rotation speed of 0,30 'exceeds 100 min ^-1 , especially 100 min ^-1 to 80 min.
It can be seen that the effect is great in the high speed region of 0 min ^-1 . In addition, the present inventors made the screws 30, 3
The relationship between the rotation speed of the screws 30, 30 'and the amount of material extruded was examined by changing the diameter of 0' variously within the range of 30 mm to 127 mm, and found to be 100 min ^{-1 to} 3000 min ^-1.
In the extremely wide rotation speed region, the same good result as the graph of FIG. 6 was obtained. Also, depending on the type of material, melting temperature, etc., 100 min ^{-1 to} 5000 min ^-1.
In the wider rotation speed range, good results can be obtained.

When the extrusion characteristic EL is smaller than 27.5,
The amount of extrusion per unit time is reduced, and the molding cost of the molded product is increased. Therefore, the actual torque Td transmitted to the screws 30, 30 'is calculated from the rotational speed n of the transmission gears 54, 54', and based on the calculation result, the theoretical torque Td is calculated.
However, the drive of the motor 41 is controlled by the controller 200 so as to be located within the range of 27.5L ³ ≦ T ≦ 40L ³ .

The drive unit rotational speed sensors 111, 11
1 'and screw shaft rotation speed sensors 113, 113'
When the difference between the output results exceeds a predetermined value, the controller 200 determines that an overload has acted on the screws 30, 30 ', and controls the drive of the drive motor 41 or issues an alarm. This is the same as in the previous embodiment. The extruder 101 ′ as described above always extrudes a molded product in the best condition while simultaneously extruding a screw 30, 30 ′.
Swift response is possible by detecting the overload that occurs in

[0053]

As described above, the provision of the torsion detecting means for detecting the torsional displacement of the screw shaft enables the overload during operation to be detected and controlled quickly, thereby ensuring the protection of the device. Can be.

In a twin screw extruder, the extrusion characteristics EL
However, by setting the theoretical torque T and the distance L between the axes so that the designed mechanical properties ML fall within the range of 27.5 ≦ ML ≦ 40, the material can be sufficiently melted while keeping the extrusion speed of the material optimal. The kneaded material can be extruded. In this case, by providing the protection device, the actual torque Td during operation can be reduced without overloading the screw.
It is possible to control so that the theoretical torque T satisfies the condition of 27.5L ³ ≦ T ≦ 40L ³ .

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an extruder according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of control of the extruder according to the present invention.

FIG. 3 is a flowchart illustrating an example of control by a control unit.

FIG. 4 is a configuration diagram showing a second embodiment of the extruder of the present invention.

FIG. 5 is a configuration diagram showing a second embodiment of the extruder of the present invention.

FIG. 6: Rotation speed (rotation speed) of a screw when extruded using an extruder having a screw diameter of 92 mm.
6 is a graph showing the relationship between the amount of material and the amount of material extruded.

FIG. 7 is a configuration diagram showing a configuration of a conventional extruder.

[Explanation of symbols]

 Reference Signs List 10 Extruder 20, 20 'Cylinder 30, 30' Screw 30a, 30a Shaft portion 31, 31 'Screw drive shaft 32, 32' Screw shaft 41 Drive motor 42 Motor shaft 51 Transmission shaft 52 Gear box 53 Drive gear 54, 54 ' Transmission gear 61 Feeder motor 62 Feeder 70 Coupling 101, 101 'Extruder 111 Drive unit rotation speed sensor 112 Screw shaft rotation speed sensor 113 Screw rotation speed sensor 120 Alarm 200 Controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiyuki Takahashi 1-80, Shinmeicho, Saiwai-ku, Kawasaki-shi, Kanagawa Pref. (72) Inventor Toshiyuki Chisaka 1-80 Shinmeicho, Saiwai-ku, Kawasaki-shi, Kanagawa

Claims (8)

[Claims] 1. An extruder comprising a cylinder, a screw rotatably disposed in the cylinder, and a driving unit for driving and rotating the screw, wherein the screw is rotated when a load is applied to the rotation of the screw. Torsion detecting means for detecting the torsional displacement of the screw shaft, and control for controlling the load on the screw based on the output of the torsion detecting means and / or issuing an alarm when the rotation of the screw is overloaded. And an extruder. 2. An extruder comprising: a cylinder; two screws rotatably and parallelly disposed in the cylinder; and a driving means for driving and rotating the two screws, wherein the driving means is driven. The extruder design mechanical characteristics ML are expressed as T / L ³ by the theoretical torque T transmitted to the screw by the above operation and the center distance L between the two screws. Mechanical properties ML
Extruder, wherein the theoretical torque T and the inter-axis distance L are set so as to fall within a range of 27.5 ≦ ML ≦ 40. 3. A extruder according to claim 2, in the case where the extrusion properties by the actual torque Td during the extruder operation and EL = Td / L ^3, the extrusion properties EL is, the design An extruder provided with control means for controlling the driving of the driving means so as to fall within the range of the mechanical characteristics ML. 4. The extruder according to claim 3, wherein a torsion detecting means for detecting a torsional displacement of a screw shaft of the screw when a load acts on the rotation of the screw; An extruder comprising: control means for controlling a load on the screw based on an output of the twist detection means and / or issuing an alarm when the twist occurs. 5. The extruder according to claim 1, wherein the torsion detecting means includes a screw shaft rotation speed sensor for detecting a rotation speed of the screw shaft, and a transmission gear fixed to the screw shaft. A driving unit rotation speed sensor for detecting a rotation speed, wherein the control unit controls and / or issues an alarm based on a difference between the respective rotation speeds detected by the screw shaft rotation speed sensor and the driving unit rotation speed sensor. An extruder. 6. The extruder according to claim 1, wherein the torsion detecting means is provided on the cylinder, and is fixed to the screw shaft and a screw rotation speed sensor for detecting a rotation speed of the screw. A drive unit rotation speed sensor that detects the rotation speed of the transmission gear, wherein the control unit controls and controls based on a difference between the respective rotation speeds detected by the screw rotation speed sensor and the drive unit rotation speed sensor. And / or an extruder that issues an alarm. 7. The extruder according to claim 1, wherein the control unit controls a supply amount of the resin raw material into the cylinder. 8. The extruder according to claim 1, wherein the control means controls the rotation speed of the screw while keeping a supply amount of the resin raw material into the cylinder constant. Extruder.