JPH04239610A - Method of controlling change in molding speed of calender - Google Patents

Abstract

PURPOSE:To prevent the variation of bank quantity at the time of mold speed change and thereby perform molding steadily in a calender for molding a sheet or film of plastic or rubber. CONSTITUTION:A molding material 3 extruded from an extruder 32 is molded into a sheet shape via a kneading roll knife device 12, swing conveyor 2, calender 4, take-off roll 5, and cooling roll 7. When the molding speed setting value is varied by a molding speed setting device 40, a calculating control device 28 acts to control the knife width of a knife device 9 and also acts to gradually change the cutting width of a molding material 3 until it is accord with further molding speed. Furthermore, the calculating control device serves to gradually change the molding speed of the calender 4 while awaiting the cutting width changed part of the molding material 3' to reach the bank 4' via the swing conveyor 2.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a control method for changing the forming speed in a calendar for forming a sheet-like or film-like member by rolling a forming material supplied from a material feeding device. This prevents fluctuations and enables stable molding.

0002

[Prior Art] A calender for forming sheets or films of rubber, plastic, etc. is usually constructed by combining three to four rolls in parallel, and rolls the material two or three times continuously to form sheets or films. to form.

[0003] In the calender, it is necessary to pay attention to the bank amount, that is, the amount of material accumulated between the rolls. In other words, if the bank amount is too large (the bank is thick), there is a risk that air will be drawn in and cause a flaw called a skip.
Since the bank does not rotate smoothly, the kneading of the material becomes uneven, resulting in uneven quality. On the other hand, if the bank amount is too small (the bank is too thin), problems such as the sheet or film being cut or thickness fluctuations increasing may occur.

[0004] Conventionally, in order to prevent this, the bank amount of the first bank was detected by a bank sensor such as a television camera, and the supply amount of the material supply device was feedback-controlled so as to maintain this at a predetermined value.

[0005]

[Problems to be Solved by the Invention] In the conventional control method, the supply amount of the material supply device is changed after detecting a change in the bank amount, so when the distance from the material supply device to the calendar is long, Even if the material supply device detects a change in the bank amount and immediately changes the supply amount, it takes time for the changed portion of the supply amount to reach the calendar, and it takes time for the bank amount to be corrected. It required For this reason, especially when changing the molding speed of the calender, the bank amount fluctuated greatly, making stable production impossible.

The present invention solves the problems in the conventional techniques and provides a method for controlling the change in the molding speed of a calendar, which prevents fluctuations in the bank amount when changing the molding speed of the calender and stabilizes production. This is what we are trying to provide.

[0007]

[Means for Solving the Problems] The present invention provides a calendar that rolls molding material supplied from a material supply device to form a sheet-like or film-like member. The material supply amount of the device is gradually changed to an amount commensurate with the changed molding speed setting value, and from the time when the changed part of this material supply amount approximately reaches the calendar, the rate of change in the material supply amount is This method is characterized in that the molding speed of the calender is changed by the rate of change.

[0008]

[Operation] According to the present invention, when the molding speed setting value is changed, the material supply amount of the material supply device is gradually changed to an amount commensurate with the changed molding speed setting value, and the material supply amount is changed. Since the calender forming speed is changed at a rate of change commensurate with the rate of change in the amount of material supplied from the point at which the changed part almost reaches the calender, the amount of material supplied to the bank and the amount of material consumed from the bank are Almost balanced, transient fluctuations in bank amount when changing molding speed are prevented, and stable production can be achieved.

[0009]

[Embodiments] Examples of the present invention will be described below.

(Embodiment 1) An embodiment of the present invention is shown in FIG. The material supply device 1 extrudes a molding material 3 from an extruder 32 and supplies it to a pair of kneading rolls 8 and 8' via a feed conveyor 33. The kneading rolls 8, 8' are rotated by the drive of the motor 34 with opposing portions facing downward, kneading the molding material 3 supplied above between the kneading rolls 8, 8' and extruding it downward. The molding material 3' that has been extruded downward is wound around the kneading roll 8, and is again wound around the kneading roll 8,
It is returned to the upper part between 8'.

A knife device 9 is arranged outside the kneading roll 8 to adjust the amount of molding material 3' supplied. The knife device 9 is constructed as shown in plan view in FIG. In FIG. 2, 10 is a screw disposed parallel to the axis of the kneading roll 8, 11 is a guide rod disposed parallel to the screw 10, and 12 is a screw to which the screw 10 is screwed, and the guide rod 11 penetrates therethrough. a movable knife which is movable along the guide rod 11 and whose tip is disposed in approximately contact with the surface of the one kneading roll 8;
13 is a fixed knife 31 attached to the guide rod 11
14 is a variable speed motor (such as an inverter motor) connected to the screw 10 via a coupling 15, and 35 is a variable speed motor (such as an inverter motor) that determines the position of the knife 12 from the amount of rotation of the motor 14 (i.e., the knife width). 13) is a position detector such as an encoder for detecting.

In this knife device 9, a motor 14 is driven by a command from an arithmetic and control unit 28 (FIG. 1) to be described later, a screw 10 rotates a predetermined number of times, and a movable knife 12 moves along a guide rod 11 to a fixed knife 30. , 31 to adjust the knife width 13 between the fixed knife 31 and the fixed knife 31. As a result, the kneading roll 8 is wound around the kneading roll 8, and the kneading roll 8,
A portion of the material 3 being returned to the upper part between 8' is cut out by the knife width 13 by the movable knife 12 and the fixed knife 31, and the amount of material supplied is adjusted.

Molding material 3 cut out by knife device 9
' is supplied to the swing conveyor 2 in FIG. The swing conveyor 2 is driven by a motor 54 to convey the molding material 3'.
This is a device for conveying the molding material 3' to the bank 4' of the calender 4, and the upper end swings back and forth in the width direction at a predetermined period with its lower end as a fulcrum, thereby uniformly distributing the molding material 3' in the width direction of the bank 4'. supply The conveyor conveyance speed by the motor 54 is set to a value approximately equal to the roll surface speed of the kneading roll 8 by the motor 34.

[0014] The calender 4 forms the material 3' supplied from the swing conveyor 2 using the roll gap of each calender roll to produce a sheet material 6.

The sheet material 6 formed by the calender 4 is pulled out by a take-off roll 5 driven by a motor 110, and is stretched due to the speed difference between the calender roll 4 and the take-off roll 5. This stretched sheet material 6' is then cooled by a cooling roll 7 driven by a motor 112 and guided to the outside to become a product.

The bank amount in the bank 4' of the calendar 4 is detected by a bank sensor 37 such as a television camera, and the bank amount detection signal 38 is sent to the arithmetic and control unit 28.

A speed detector 52 (such as a tacho generator) detects the rotation of the final stage roll drive motor 50 of the calendar 4 as a molding speed, and its molding speed detection signal 24 is fed back to the calendar molding speed control device 42. At the same time, it is also input to the arithmetic and control unit 28.

Further, the speed of the take-off line such as the take-off roll 5 and the cooling roll 7 is controlled by the tacho generator 1.
14, 116 and the take-off line speed control device 10
0, and is always operated at a constant speed ratio relative to the calendar speed signal 102 based on the draw ratio, that is, the stretching ratio set by the draw setting device 103.

Furthermore, the cooling roll speed signal 101 is inputted to the arithmetic and control unit 28 as the forming speed of the product sheet, and the cooling roll speed/calendar roll speed (=draw ratio) is always actually measured on-line.

A sheet thickness detector 17 and a sheet width detector 16 are provided downstream of the take-off roll 5 to detect the thickness and width of the sheet 6'. Then, the sheet thickness detection signal 23 and the sheet width detection signal 22 are sent to the arithmetic and control device 28. In addition, kneading rolls 8, 8'
is provided with a roll gap detector 19 for detecting the roll gap, and outputs a roll gap detection signal 2.
5 is sent to the arithmetic and control unit. In addition, the speed detector 20 (
A tacho generator, etc.) detects the rotation speed of the kneading roll 8, and the roll speed detection signal 26 is sent to the arithmetic and control unit 28. Further, a knife width detection signal 36 output from the position detector 35 is sent to the arithmetic and control unit 28.

[0021] The calender molding speed setting device 40 is composed of a volume control, etc., and the molding speed is set by an operator's operation. The molding speed setting signal 41 is then sent to the arithmetic and control unit 28. Based on this molding speed setting signal 41, the arithmetic and control unit 28 outputs a molding speed command signal 43 as described later. This forming speed command signal 43 is sent to the calender forming speed control device 42, and the drive motor 50 of the final stage roll of the calender 4 is driven. The rotation of the drive motor 50 of this final stage roll is detected by a speed detector 52, and the roll speed is feedback-controlled so that it matches the forming speed command. Further, the upstream rolls are also controlled in proportion to the speed of this final stage roll.

The arithmetic and control unit 28 outputs a knife width command signal 29 corresponding to the amount of material supplied. This knife width command signal 29 is input to the variable speed motor control device 44, and the knife drive motor 14 is driven. motor 14
The rotation amount, that is, the knife width 13, is detected by the position detector 35, and feedback control is performed so that it matches the knife width command.

Reference numeral 45 is a push button for acceleration/deceleration compensation control which is used when the control device according to the present invention fails and becomes unusable, and when pressed, the molding speed change control according to the present invention is canceled. That is, the relay 54 is energized, the switches 54a and 54b are turned off, and the switches 54a' and 54a are turned off.
4b' is turned on, the molding speed setting signal 41 is directly sent to the calender molding speed controller 42, and the molding speed setting signal 41 is sent directly to the calender molding speed controller 42.
The molding speed of the calendar 4 is controlled in direct conjunction with the setting operation of 0.

Control by the arithmetic and control unit 28 will be explained with reference to FIG. The arithmetic and control unit 28 performs a constant cycle T1.
The calendar forming speed setting signal 41 is read every second. If the speed setting value is not changed, the speed setting value is maintained at a predetermined value in accordance with the detection signal 38 of the bank amount (bank height, bank width, etc.) detected by the bank sensor 37 every T2 seconds. A knife width command signal 29 is sent to perform feedback control to control the position of the movable knife 12, that is, the width of the molding material 3' supplied to the calendar 4 (=knife width 13).

[0025] The operator operates the calender forming speed setting device 40.
When the molding speed set value 41 read at a constant cycle T1 seconds is changed by operating T1, the arithmetic control unit 28 temporarily suspends feedback control and performs acceleration/deceleration compensation control (molding speed change control) according to the present invention. Start. That is,
Drive the motor 14 so as to simultaneously satisfy the following conditions (a) and (b), control the knife width 13, and control the material supply amount (a) Before acceleration/deceleration compensation control, speed detector 52 The amount of change in the knife width 13 that is proportional to the difference V2 - V1' between the molding speed detection value V1' detected at 1 and the newly read molding speed set value V2 is given by equation (1). Amount of change in knife width 13 = [width of sheet 6' x sheet 6'
Thickness x (V2 - V1')
× draw ratio] ÷ [molding material 3'
Thickness x kneading roll 8
speed〕
…(1)(
(b) When changing the calender forming speed, the change rate A of the calender forming speed is determined in advance, and the change rate B of the knife width 13 (proportional to the change rate of the supply amount of the molding material 3' cut out by the knife device 9). , the rate of change in calendering speed A
is given by equation (2) so that it becomes a value corresponding to . Change rate B of knife width 13 = [width of sheet 6' x sheet 6
′ thickness × draw ratio] ÷
[Thickness of molding material 3' x speed of kneading roll 8] x A

...(2) After starting the change control of the knife width 13 so as to simultaneously satisfy the conditions (a) and (b) above, the starting point is the calendar 4.
The expected time Td until reaching the knife width is determined in advance from the length of the swing conveyor 2 and its speed (approximately equal to the speed of the kneading roll 8), and the time from the start of the knife width change control is measured. From the time when the expected time Td is reached, the molding speed of the calendar 4 is changed at the predetermined rate of change A to a new set value V2. Then, when the calendar molding speed V2' increases to the molding speed V2 set by the molding speed setting device 40, the acceleration/deceleration compensation control is terminated, and T2
Returning to the feedback control by the bank sensor 37 every second.

By controlling the knife width 13 and the speed of the calendar 4 as described above, it is possible to change the molding speed while keeping the bank amount constant.

Note that when the molding speed is changed, the extrusion amount of the extruder 32 is also changed to a corresponding amount.

The above description has been made regarding the case where the molding speed of the calendar 4 is increased, but the same applies to the case where the molding speed is decreased.

Further, in the above embodiment, a variable speed motor such as an inverter motor is used as the knife width adjustment motor 14, and the calendering speed change rate A is determined first, and the change rate B of the knife width 13 is determined based on this. Although the speed of the knife width adjustment motor 14 was set accordingly, the speed of the knife width adjustment motor 1
4 is a constant speed rather than a variable speed, the rate of change B of the knife width 13 is uniquely determined, so the rate of change A of the calender forming speed is determined in accordance with the rate of change of the knife width 13. You can also do that.

In addition, as described above, the knife width adjustment motor 1
Even when a constant speed motor is used for motor 4, the motor 14 is driven intermittently as shown in FIG.
By controlling the off-time duty, it is also possible to approximately match the knife width change rate B to match the change rate A of the calendering speed.

(Example 2) In the above example, a case was explained in which a mixing mill was used as the material supply device.
The present invention can also be applied to an extruder method. An example of the configuration in the case of an extruder method is shown in FIG. In Figure 5,
The same reference numerals are used for parts common to those in FIG. The extruder 32 constituting the material supply device 1' is rotated by a motor 60. The discharge amount of the extruder 32 is determined by its rotation speed. This rotational speed is detected by a speed detector 62 such as a tacho generator.

The arithmetic and control device 28 outputs a discharge amount command signal 64. This discharge amount command signal 64 is input to the extruder control panel 66 and becomes a rotation speed command signal 69 to drive the extruder motor 60. A rotational speed 68 of the extruder motor 60 is detected by a rotational speed detector 62, and is feedback-controlled so as to match a rotational speed command signal 69.

Control by the arithmetic and control unit 28 in FIG. 5 is as follows. The arithmetic and control unit 28 performs a constant cycle T1.
The calendar forming speed setting signal 41 is read every second. If the speed setting value is not changed, the speed setting value is maintained at a predetermined value in accordance with the detection signal 38 of the bank amount (bank height, bank width, etc.) detected by the bank sensor 37 every T2 seconds. A discharge amount command signal 64 is transmitted to perform feedback control to control the rotational speed of the extruder motor 60, that is, the discharge amount of the molding material 3' supplied to the calender 4.

When the operator operates the molding speed setter 40 to change the molding speed set value 41 read every fixed cycle T1 seconds, the arithmetic and control unit 28 temporarily interrupts the feedback control, and the present invention Start acceleration/deceleration compensation control (molding speed change control). That is, the following (
The motor 60 is driven so as to satisfy the conditions c) and (d) at the same time, and the discharge amount is controlled to control the material supply amount. (c) The speed of the extruder motor 60 is proportional to the difference V2 - V1' between the calender molding speed detection value V1' detected by the speed detector 52 before acceleration/deceleration compensation control and the newly read molding speed set value V2. The amount of change in rotational speed is given by equation (3). Amount of change in rotational speed of extruder motor 60 = [width of sheet 6' x thickness of sheet 6' x
(V2
-V1') x draw ratio] ÷ [extrusion

Discharge amount per unit rotation of machine 32]


... (3) (d) When changing the calendering speed, the rate of change A of the calendering speed is determined in advance, and the rate of change C of the rotational speed of the extruder motor 60 (extruder 3
(proportional to the rate of change in the discharge amount of the molding material 3' discharged from 2) is given by equation (4) so that it becomes a value corresponding to the rate of change A in the calender molding speed. Rate of change in rotational speed of extruder motor 60 C = [Sheet 6'
Width x thickness of sheet 6'
×
Draw ratio] ÷ [unit times of extruder 32

Discharge amount per transfer〕×A... (4) Above (
The expected time Td from the start of the control to change the rotational speed of the extruder motor 60 until the starting point reaches the calendar 4 so as to simultaneously satisfy the conditions (c) and (d) is determined by the length of the swing conveyor 2 and Determine the speed in advance from that speed, measure the time after starting control to change the rotational speed of the extruder motor 60, and from the time when this reaches the above-mentioned expected time Td, change the molding speed of the calendar 4 to the new set value V2. When the calender forming speed V2' increases, the acceleration/deceleration compensation control is ended and the feedback control by the bank sensor 37 is returned to every T2 seconds.

By controlling the rotational speed of the extruder motor 60 and the speed of the calendar 4 as described above, the molding speed can be changed while the bank amount is kept constant.

The above description has been made regarding the case where the molding speed of the calendar 4 is increased, but the same applies to the case where the molding speed is decreased.

(Embodiment 3) Although the present invention has been described above as an example in which it is applied to a calender for plastics, it is also possible to apply it to a calender for rubber. An example of the rubber 3 extruded from an extruder 32 is shown in FIG.
is cut from the feed conveyor 33 through kneading rolls 8, 8' into upper strip 3A and lower strip 3B by knives 12A, 12B, and supplied to calenders 4A, 4B via upper bank conveyor 2A and lower bank conveyor 2B, respectively. The molded sheet 6 is then formed with the fabric 6a sandwiched therebetween. When the molding speed set value is changed, the arithmetic and control unit 28 gradually changes the knife width to a value corresponding to the molding speed, and simultaneously changes the widths of the strips 3A and 3B. In addition, this changed part passes through conveyors 2A and 2B, and then the upper and lower banks 4A',
Wait until it reaches 4B' (if the lengths of conveyors 2A and 2B are almost equal, the waiting time will be the same)
Change the molding speed of B. This makes it possible to suppress fluctuations in banks 4A' and 4B' when changing molding speed,
Stable production can be achieved.

[0038]

As explained above, according to the present invention, when the molding speed setting value is changed, the material supply amount of the material supply device is gradually changed to an amount commensurate with the changed molding speed setting value. At the same time, the molding speed of the calendar is changed at a rate of change commensurate with the rate of change in the material supply amount from the point at which the changed portion of the material supply amount approximately reaches the calender, so that the amount of material supplied to the bank is changed. The amount of material consumed from the bank and the amount of material consumed from the bank are almost balanced, and transient fluctuations in the amount of bank when changing the molding speed are prevented, allowing stable production.

[Brief explanation of the drawing]

FIG. 1 is a mechanical diagram and a control block diagram of a calendar 4 and a material supply device 1 showing an embodiment of the present invention.

2 is a plan view of the material supply device 1 of FIG. 1. FIG.

FIG. 3 is a time chart showing control operations by the arithmetic and control device of FIG. 1;

FIG. 4 is a time chart showing another example of driving the knife width adjustment motor 34. FIG.

FIG. 5 is a mechanical diagram and a control block diagram of a calendar 4 and a material supply device 1' showing another embodiment of the present invention.

FIG. 6 is a mechanism diagram and a control block diagram showing an embodiment in which the present invention is applied to a rubber calender.

[Explanation of symbols]

1,1' Material supply device 3,3' Molding material 4 Calendar 6′ sheet 40 Molding speed setting device 41 Molding speed setting signal

Claims (1)

[Claims] Claims: 1. In a calendar that rolls molding material supplied from a material supply device to form a sheet-like or film-like member, when a molding speed setting value is changed, the material supply amount of the material supply device is changed to The molding speed is gradually changed to an amount commensurate with the changed molding speed setting value, and from the time when the changed portion of the material supply amount approximately reaches the calender, the calender molding is performed at a rate of change commensurate with the rate of change in the material supply amount. A method for controlling a change in molding speed of a calendar, characterized by changing the speed.