JPH05269822A - Automatic control method and device for extruder - Google Patents

Abstract

PURPOSE:To provide automatic control method and device, capable of effecting necessary conditions correctly and quickly without any trouble upon starting and stopping an extruder and the circumferential devices thereof. CONSTITUTION:The starting and stopping of an extruder are controlled automatically by a method wherein the output signals of the positions of the levels of materials, which are outputted by respective level sensors L2, L3, L4, L5, L6 provided on the material outlet passages 6 of a main hopper 3, a sub-hopper 4, the hopper 51 of a feeder 5 and the feeder 5 respectively, the output signal of the number of rotation of a screw, which is outputted by a screw tachometer, and the current output signal of a main motor, which is outputted by a main motor ammeter 12, are sent into a controller while the opening and closing operations of respective hoppers, the operation of the feeder and the rotary operation of the screw are controlled by the controller in accordance with respective specified data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and apparatus for starting and stopping an extruder accurately and without trouble without relying on human experience or intuition.

[0002]

2. Description of the Related Art As an extruder, as shown in FIG.
A screw extruder and its peripheral devices are one of the typical examples. This extrusion device relates to sheet extrusion, and the raw material A in the main hopper 3a is the screw feeder 5a.
A fixed amount is supplied near the base of the screw 2a via. The supplied raw material A is heated, melted and transported by the extruder 1a and extruded in a sheet shape through the mold 7a,
After passing through the take-up machine 8a, it is taken up by the take-up machine 9a. 10a is a heat medium circulating tank for adjusting the temperature of the screw 2a, 13a is an oil pump of oil for lubricating gears in the gear box, and 14a is heat for adjusting the temperature of the barrel of the extruder 1a. It is a medium circulation tank.

[0003]

When starting or stopping such an extruder, a large number of man-hours and work proficiency are required. For example, at the time of starting, the screw, the screw of the feeder, the oil pump that lubricates the gear box, the start of the heat medium circulator for adjusting the temperature of the screw and barrel, the opening of the valve of the hopper, etc. or the input of raw materials and purging material It is very difficult to determine the order, timing, etc., etc. In order to complete such work accurately, quickly, and without trouble, it was necessary to arrange a skilled worker around the extruder for a long time. Especially when chemical reactions take place in the extruder, as seen in recent reactive processing, the peripheral equipment of the extruder becomes very complicated, and the operations involved in starting and stopping these equipment are Increasingly complex, and the demands on skilled workers are increasing.

It is an object of the present invention to avoid the problem of sticking by a skilled person as described above, and to start and stop an extruder accurately, quickly and without trouble and without increasing man-hours.

[0005]

SUMMARY OF THE INVENTION An automatic extruder control method according to the present invention is designed to control the level position of a raw material by each level sensor provided in each of a main hopper, a sub hopper, a hopper of a feeder and a raw material outlet passage of a feeder. The output signal, the output signal of the rotation speed by the screw tachometer, and the current output signal of the main motor by the main motor ammeter are sent to the controller, and the controller opens and closes each hopper according to each specified data, the feeder operation,
It is characterized in that the screw rotation operation is controlled to start or stop the extruder.

Further, the automatic controller of the extruder of the present invention is
The main hopper and the sub hopper are provided with their raw material outlets facing the hopper of the feeder, and in the extrusion device in which the raw material outlet passage of the feeder is connected to the raw material supply port of the extruder, the main hopper, the sub hopper, and the feeder A level sensor is provided in each of the raw material outlet passages of the hopper and the feeder, a screw rotation sensor and a current detection sensor of the main motor are provided, and
Receive the output signal of the level position of the raw material by the level sensor, the output signal of the rotation speed by the screw rotation sensor, the current output signal of the main motor by the current sensor of the main motor, open and close operation of each hopper according to each designated data, It is characterized by having a controller for controlling the feeder operation and the screw rotation operation.

In the present invention, the designated data is determined based on the standardization of the work created by referring to the data such as the work of the expert. In addition, it is preferable to provide the main hopper at two positions above and below the opening / closing valve of the main hopper, since the presence / absence of the raw material can be accurately confirmed, and it is preferable to provide level sensors also in the hopper of the feeder.

[0008]

[Function] Level sensors installed in the main hopper, sub hopper, and feeder material outlet passages check the presence or absence of raw material in each hopper, and output a signal to that effect to the controller to specify the presence or absence. Depending on the data, either the automatic start switch or the automatic stop switch will be released or the next step will proceed.

A signal indicating the rotational speed of the screw tachometer is output to the controller, and when the screw rotational speed reaches the set value of the set data, further increase or decrease is stopped. Further, the ammeter of the main motor outputs a signal corresponding to the current value to the controller, and if the value is less than or equal to the lower limit set value set in the designated data, it proceeds to the next step.

[0010]

1 is a schematic view of an extruder and its peripheral equipment according to the present invention. In FIG. 1, 1 is an extruder, 3 is a main hopper, 4 is a sub hopper, 5 is a screw feeder, 7 is a die, 8 is an extruded sheet take-up machine, and 9 is a take-up machine.

In the extruder 1, the temperature of the barrel is adjusted by the heat medium circulated from the circulation tank 14, and the temperature of the screw 2 is circulated from the circulation tank 10. Temperature is adjusted by the medium, and tachometer 11
The rotation speed of the screw is measured by the ammeter, and the current when the screw is rotationally driven is measured by the ammeter 12. Further, 13 is an oil pump for oil that lubricates gears and the like in the gear box.

The main hopper 3 is for supplying the raw material A into the barrel of the extruder 1 through the screw feeder 5, and its supply port 31 is at the screw feeder 5.
Of the level sensor L at the bottom of the hopper 51 and the supply port 31 below the hopper 51.
₃ and L ₂ are arranged. Reference numeral 32 is an open / close valve.

The sub hopper 4 is for supplying the purging material B into the barrel of the extruder 1 through the screw feeder 5, and its supply port 41 is arranged toward the hopper 51 of the screw feeder 5. A level sensor L ₄ is arranged at the bottom of the level sensor. In addition,
Reference numeral 42 is an opening / closing valve.

Further, level sensors L ₅ and L ₆ are respectively provided in the raw material passage 6 between the bottom of the hopper 51 of the screw feeder 5 and the screw feeder and the screw.
Are arranged. The level sensor may be of any type such as torque type, capacitance type, vibration type, ultrasonic type and the like. Also, a screw tachometer,
As for the ammeter of the main motor, any type of ammeter can be used as long as an output corresponding to the rotation speed and the current can be obtained. The raw material A is put into the main hopper 3, and the raw material is quantitatively supplied using this.

The procedure for starting this extruder and its peripheral equipment from a stopped state is as follows. (1) Turn on the automatic start switch (manual operation). (2) Whether or not the raw material A of the main hopper 3 is filled is checked by the level sensor L ₃ and a signal is sent to a computer (not shown). If yes, continue. If no, go back to 1). (3) Whether or not the purging material hopper 10 is filled with the purging material 16 is confirmed by the level sensor L ₄ , and a signal is sent to the computer. If yes, continue. If no, go back to 1). (4) Whether or not the hopper 51 of the screw feeder 5 is empty is checked by the level sensor L ₅ , and a signal is sent to the computer. If empty, a sign is given to move to the next step. (5) The oil pump 13 and the screw 2 are started, and a signal related to current is sent from the main motor to the computer. If this value is less than or equal to the lower limit set value, a signal is sent from the computer and the screw 2 is accelerated. .. (6) When the timer setting time has passed, the screw feeder 5 starts, and then the opening / closing valve 42 of the sub hopper 4
Is opened, and the purging material B starts being charged. (7) When the timer set time has elapsed, it is checked whether or not the purging material B is exhausted by using the level sensor L ₆ , and a signal is sent to the computer. In the case of no supply, the computer issues a command to open the opening / closing valve 32 of the main hopper 3 and to insert the raw material A. (8) Next, when the set time of the timer has passed, the circulation tank 14
Starts and the temperature adjustment of the extruder barrel begins. (9) When the set time of the timer has passed, the circulation tank 10 is started and the temperature adjustment of the screw 2 is started. (10) Next, a signal for increasing the rotation speed of the screw 2 is sent from the computer to start the speed increase. An output corresponding to the number of revolutions is sent from the screw tachometer 11 to a computer, and when the output reaches the upper limit set value, a signal to stop acceleration is issued, and then the take-up machine 8 is started.

Next, the procedure for stopping the extruder and peripheral equipment from the operating state is as follows. (1) Turn on the automatic stop switch (manual operation). (2) Whether or not the purging material B is filled in the purge hopper ₄ is checked by the level sensor L ₄ ,
A signal is sent to the computer. If yes, continue. (3) Whether or not the raw material A of the main hopper 3 has become empty is checked by the level sensor L ₃ , and a signal is sent to the computer. If yes, the open / close valve 32 of the main hopper 3 is closed. (4) Whether the hopper 51 of the screw feeder 5 and the raw material passage 6 are empty or not is determined by the level sensor L ₅ respectively.
And L ₆ and the signal is sent to the computer. If both are empty, open / close valve 4 of sub hopper 4
2 is opened, and the purging material B starts to be charged. (5) When the timer setting time has passed, the level sensor L ₆ checks again whether the raw material passage 6 between the screw feeder 5 and the screw 2 is empty, and a signal is sent to the computer. If yes, a signal is sent from the computer to stop the circulation tank 10. (6) An output signal corresponding to the magnitude of the current is sent from the main motor ammeter 12 to the computer, and it is checked whether this value has dropped to the lower limit set value. If yes, continue. (7) The rotation speed deceleration signal of the screw 2 is output from the computer, and the rotation of the screw 2 is decelerated. (8) From the screw tachometer 11, an output signal having a magnitude corresponding to the rotation speed of the screw 2 is sent to the computer, and it is checked whether or not the rotation speed has dropped to the lower limit set value. In the case of yes, the circulation tank 14, the screw 2, the oil pump 13, the take-up machine 8, and the take-up machine 9 are stopped. If no, go back to (7).

[0017]

According to the method and apparatus of the present invention, by automatically controlling the operation of starting the extruder and its peripheral devices from the stopped state, or conversely, stopping it from the operating state, this kind of Unmanned work can be achieved and man-hours can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an example apparatus of the present invention relating to starting and stopping an extruder.

FIG. 2 is a schematic view of a device for starting and stopping a conventional extruder.

[Explanation of symbols]

1,1a Extruder 2,2a Screw 3,3a Main hopper 4 Sub hopper 5,5a Screw feeder 7,7a Mold 8,8a Drawer 9,9a Winder 11 Tachometer 12 Ammeter L ₂ , L ₃ , L ₄ , L ₅ , L ₆ Level sensor A Raw material B Purging material C sheet

Claims (2)

[Claims] 1. An output signal of a raw material level position by each level sensor installed in each of a main hopper, a sub hopper, a hopper of a feeder and a raw material outlet passage of a feeder, and an output signal of a rotation speed by a screw tachometer. The main motor current output signal from the main motor ammeter is sent to the controller, and the controller controls the opening and closing operation of each hopper, the feeder operation, and the screw rotation operation to start or stop the extruder according to each specified data. Extruder automatic control method. 2. An extruder in which a main hopper and a sub hopper are provided with their raw material outlets facing the hopper of a feeder, and the raw material outlet passage of the feeder is connected to the raw material supply port of the extruder, the main hopper, Sub hopper,
A level sensor is provided in each of the feeder hopper and the raw material outlet passage of the feeder, a screw rotation sensor and a current detection sensor of the main motor are provided, and the output signal of the raw material level position by the level sensor and the screw rotation sensor are provided. It is equipped with a controller that receives the output signal of the rotation speed and the current output signal of the main motor from the main motor current detection sensor and controls the opening / closing operation of each hopper, the feeder operation, and the screw rotation operation according to each specified data. Extruder automatic control device.