JPS58175217A - Extrusion line control system for foamable insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extrusion lie/control method for foam insulated wire,
In particular, it relates to an extrusion line control system for this type of electric wire, where control variables such as the outer diameter and capacitance of the extrusion-coated foam insulation are multivariable.

In general, for communication cables, due to the requirement of electrical characteristics to reduce transmission loss, capacitance It (C)
Therefore, an insulator with a small dielectric constant is extruded and coated onto the conductor. The insulator also needs to support the cable. For this reason, the insulation of communication cables,
Expanded polyethylene (PEF), which is polyethylene with a large number of bubbles, is often used.

The 1° extrusion line for foamed insulated wires using foamed insulated polyolefin resin such as polyethylene is
As shown in the figure. In this line 1o, the conductor rough wire 11 pulled out from the stack 10a is passed through the wire drawing machine 12 to the core wire 1.
3, and annealed in an electric current annealing type annealer 14.

Next, the core wire 13 is guided through a first dancer 15 to a preheater 16, preferably of an induction heating type, and then continuously supplied to an extruder 17. Preheater 16 is core a1
By heating 3, uniform foaming is produced and the adhesion between the insulator and the core wire is improved. Further, a foamed insulating composition containing a polyolefin resin and an organic foaming agent is supplied from a popper 18 to the extruder, and a cylinder 19
The cross head 21 is fixed by the screw 2o provided inside.
(Figures 3-4). The screw is rotated by a motor 22, and a cylinder heater 23 divided into cylinder heater parts 23-1 to 23-4 is provided on the outer periphery of the cylinder. Rotation of screw 2o, heating of 7 cylinder heater 23 and cross head 21)
(The foaming agent is decomposed by the heating of the cross-head heater 24 composed of the cross-head heater parts 24-1 and 24-2 at a temperature of +ff- or above, and the foamed insulating composition is heated in the 90' direction from the crosshead constriction section 25. Switch and nipple 26
is extrusion coated onto core #s13.

Here, when the foaming gas in the foamed insulation material, which was loaded with high pressure in the extruder 17, is extruded into the atmosphere, it is released from the high pressure and expands in the resin, and the pressure in the foamed foam is reduced to atmospheric pressure. It becomes maximum when it becomes equal to . When this foamed insulator is cooled, the pressure within the foam decreases, and it tends to shrink.

For this purpose, a movable cooler 27 is provided in the extrusion line. This cooling section comprises, for example, a water tank 29 as shown in FIGS. 1 and 2, in which a movable water tank 2B is slidably provided at the front stage. The movement distance of the moving water tank 28 from the crosshead 21, especially the nipple 26 is adjusted to suppress the growth of chemical foam from the outer periphery by water cooling, and at the same time, a barrier wall is formed on the outer peripheral surface of the resin to prevent foaming from the inside. This requires the degree of foaming of the foaming gas in the foamed insulation to be adjusted and thus controlled to obtain its desired outer diameter and capacitance.

Note that the cooler 27 does not need to be movable, and may be replaced with a type that allows the amount of water, water temperature, etc. to be changed, for example.

An outer diameter measuring device 30 and a capacitance measuring device 31 for measuring the outer diameter and capacitance are provided on the line 1o, respectively. The measuring device 3o is M501 manufactured by Anritsu Electric Co., Ltd.
This is a B-type laser outer diameter measuring device with an accuracy of ±1 μm.

In addition, the measuring device 31 is manufactured by Bucks, High Wyc, UK.
OMBE KI-700CGA manufactured by BETA (Sen f
-KG500) with an accuracy of ±0.1 PF/m5
The electrostatic field 1 (PF/m) of the electric wire can be measured.

In addition to the above-mentioned both-side regulators, the extruder 1T is provided with a cylinder thermometer TMi~4, and a crosshead 2
1 is provided with a resin thermometer TM5, a crosshead thermometer TM6, and a resin pressure gauge (CZ-IP type manufactured by Rika Kogyo Co., Ltd.) PM.

The foam insulated wire is taken off by a take-off machine 32, passed through a second dancer 33, and wound onto a drum by a take-up machine 34.

As is clear from the above explanation, in the production of foam insulated wires, the outer diameter of '''*m (, D) and the electrostatic field it (C) of the insulator are uniform in the longitudinal direction of the wire. There must be.

Conventionally, a given capacitance and outer diameter are obtained.

When controlling the extrusion of the sea urchin extrusion line 10,
In the line system, the rotation speed of the screw 20 of the extruder 17, the voltage applied to the preheater 16, etc. were controlled in proportion to the take-up speed of the take-off machine 32, that is, the line speed.

Further, the capacitance (C) was controlled by moving the moving water tank 28. The outer diameter (D) was adjusted manually. However, when adjusting the outer diameter manually (also by changing the extruder screw rotation speed and extruder temperature), the outer diameter could only be adjusted empirically. Of course, if you move the mobile aquarium, the capacitance will change, but in that case, the outer diameter will also change at the same time, so even if you can control the capacitance, you cannot control the outer diameter. The diameter varies from the desired value.As a result, it has been extremely difficult to independently control the capacitance and outer diameter to produce a wire of constant high quality.

In short, in the extruder line, when the extrusion temperature of the extruder is constant, reducing the screw rotation or increasing the line speed will reduce the wire outer diameter, and when the extrusion temperature increases, the foaming rate will increase. On the other hand, as the outer diameter increases and the line speed increases, the time interval in the cooling and solidification trench after extrusion becomes shorter, and foaming stops early and the foaming rate decreases? As shown, there is a deep relationship between each factor, and it is necessary to stably control the outer diameter and capacitance (foaming rate) while taking these interrelationships into consideration.

That is, a large number of controls (in the case of this embodiment, the outer diameter D of one wire)
, the capacitance of the insulator ftc).
and the display temperatures C3 and C4 of cylinder thermometers TM3 and TM4.
, the displayed temperature C6 of the crosshead thermometer TM5, the displayed temperature C5 of the resin thermometer TM5, the displayed pressure P of the resin pressure gauge PM
al is a large number of manipulated variables (in the case of this example, screw 2
0 rotation speed, applied voltage to preheater 16, applied voltage to cylinder heaters 23-3 and 23-4, and cross-head heater 24-
In control (multivariable control) when any of the applied voltages 1 and 2 or the amount of movement of the moving water tank 28 from the crosshead is operated (multivariable control), each control amount is determined to be the desired value by measuring the measured amount. It has been extremely difficult in the prior art to simultaneously and automatically control the respective manipulated variables so that the value of .

In addition, due to the correlation between the controlled variable and manipulated variable of multiple variables, a control method that relies on each pair of controlled variable and manipulated variable alone cannot quickly deal with disturbances, has poor stability of the controlled variable, and has poor response. It had the disadvantage of being inferior in gender.

Furthermore, in these 9 methods, the capacitance C and outer diameter are not controlled according to the line speed, so the product becomes scrap until the line speed reaches a steady state, and furthermore, the product becomes scrap until the line speed reaches a steady state. However, since C and D do not remain at a constant value until the resin temperature rises, the product during this time also becomes waste, resulting in a poor production yield.

Therefore, the main object of the present invention is to perform multivariable control of a foam insulated wire extrusion line using the detection elements of Measurement 1, including control variables of wire outer diameter, capacitance, and line speed.
Extrusion line control for foam insulated wire that improves production yield by simultaneously and automatically controlling the operating variables of the extruder, preheater, and cooler so that each controlled variable reaches the desired value (set target value) The purpose is to provide a method.

Another object of the present invention is to provide a side fence means in which stability and/or responsiveness are further improved in such a system, and which can quickly cope with disturbances.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The extrusion line control system for foam insulated wires according to the present invention will be described in detail below with reference to the drawings in an embodiment in which it is applied to an extrusion line shown in FIGS. 1 and 2.

In the control method shown in FIG. 5, the controlled variables (outer radius and capacitance C) of the wire extruded from the foam insulated wire extruder line 10, which is the controlled object, and the state variables that affect the controlled variables (cylinder temperatures C3 and C4, crosshead temperature C6, resin temperature C3, and resin pressure P), a plurality of manipulated variables (rotational speed of screw 2o, Preheater 16
(the voltage of the cylinder heaters 23-3 and 23-4, the voltage of the cross-head heaters 24-1 and 24-2, and the moving distance of the moving water tank 28 from the crosshead in the cooler 27), the control amount The purpose is to control the manipulated variable so that it is adjusted to the target. Note that YLSO represents the input of the line speed to be set.

The line speed YLs as a measured quantity is input to the controller CR, and the controller outputs the screw rotation speed U1 and the breaker voltage U as manipulated variables in accordance with the line speed. Next, the measured quantities Y1 to Yf are multivariably controlled by the CPU to output manipulated quantities U1 to U6.

To explain this in detail with reference to FIG. 6, the control amounts Y1 to Y2
is drawn from the drawing point 35 to the target value YR, ~YR2
36 to obtain the difference between the target value and the control amount.

These differences ε1 and e2 are applied to the calculation element C. Element C provides the manipulated variables U'c, . . . U'c, by linear processing. These manipulated variables are applied to integrators, 11 to I6, respectively, and an integration operation is performed to obtain the quantity U.
It is applied to each manipulated variable U, ~U6 as C1~Uc6.

This quantity Uc is expressed as follows as a result of performing an integral function.

This integral operation includes not only a linear integral function by an integrator but also an operation that includes or is similar to an integral function.

Further, the integral operation may include dynamic compensation.

It should be noted that each element of the calculation element C is calculated based on the optimal control theory and the target value YR using the control object as a model before automatically controlling the foam insulated wire extrusion line 10 as the control object.

Manipulated variable U'C, ~U'c6 when giving ~YR,
, the manipulated variables U1 to U6, and a simulation of the behavior of the controlled variables Y1 to Y2, and are determined most appropriately.

Further, the extraction point 35 is connected to the subtraction point 37 via the feedback element F. As a result, the control a W
Feedback operation is performed by linear processing on the middle 11 constant fLY+~Y7 including k Y l~Y2, and the manipulated variable U, ~
Subtractively applied to U6. This feedback operation may include dynamic compensation. Each element of the feedback output UF is determined in advance by the aforementioned optimal control theory and simulation.

Furthermore, one drawer point 38 is connected to the summing point 37 via a feedforward element N. As a result, a feedforward operation, that is, a proportional operation is performed on the target values YR, to YR2 by linear processing, and is applied additively to the manipulated variables U, -U. This feedforward operation may include dynamic compensation. This is the feedforward output UN.

Each element is also determined in advance by optimal control theory and simulation, as described above.

In this way, as a result of three types of operation inputs being supplied to the manipulated variable U, the manipulated variable U finally becomes as follows.

U=Uc-OF-TO UN When the sum output Uc-UF+TJN supplied to the manipulated variable exceeds a predetermined range, a limiter that stops and corrects the integral operation,...L6 is interposed in each operation line. has been done.

In Figure 6, the part surrounded by the dotted line is TO8BAC made by Tokyo Shibaura Electric Company? /represents a 40-inch CPU, target value YR,
~The input interface of YR2 is the input/output device l10.
-1, the output interface of the manipulated variables U1 to U6 is D
/A conversion input/output device l10-2, control amount Y, ~
Y! Input/output device l for A/D conversion at the input interface to the backward path of the measured quantity Y, -Y7
10-3 is interposed.

The multivariable automatic control system configured as described above operates as follows.

First, the extruder line 10 is operated to control the control amount Y1 to Y2.
The initial value of the integral operation is set according to the measured quantities Y, -Y7 including (FIG. 7). Next, the CPU sets the target value YR,
~YR, Read data of measured quantities Y1 to Y7 including controlled quantities Y and -Y2. The calculation element C1 of the CPU, the feedback element F1, and the feedforward element N each calculate a value expressed by the above-mentioned determinant.

This manipulated variable output needs to be controlled and maintained within a predetermined range. Therefore, it is determined whether each manipulated variable output value is within the range, and if it is within the range, an integral operation is performed, and if it exceeds the range, each limiter L, ~L6 (Figure 7).

In this way, each of the manipulated variables U'c, . . . U'c6 causes the integrators 2, .

If such a function is introduced, even though there is an input operating range as the manipulated variable as in this embodiment, if the integral operation is performed from the start of the operation, the difference between the manipulated variable and the target value will initially be Since ε, .

In this way, the integrator repeats the integration operation until the difference between the target value and the controlled variable becomes zero, forming a control loop so that the controlled variable approaches the target value as much as possible.

Thus, the manipulated variable U U=Uc-UF+UN is calculated and output to the extrusion line 10 as a controlled object.

In this case, the feedback output UF of the feedback element F has the function of stabilizing the inherent characteristics of the control system.

On the other hand, the output UN of the feedforward element N. accelerates its rise so that the control amount Y quickly approaches the target value YR, and has a particularly great effect at the start of operation of the extrusion line. This element N further improves the responsiveness of the control system.

In this way, the manipulated variable U is the extrusion lie/10 as the controlled object.
When the signal is output to , the next sampling is delayed by a predetermined time and the next operation is repeated again.

In the control method of the present invention, the measured quantity, that is, the line speed YLs
According to controller C1 (operated amount U, ~U
In order to generate can have complementary functions, so the capacitance C and the outer radius are controlled to always be constant depending on the line speed. This makes it possible to manufacture wires and cables with constant C and D from the start-up of the line speed, greatly reducing waste during start-up, and producing high-quality foam insulated wires with C and D within the standard. Manufacturing becomes possible.

In the example described above, the case was explained in which there were two controlled variables and target values, six manipulated variables and manipulated variables, and seven measured quantities. A positive integer,
The present invention is equally applicable to cases where n, m≧l).

Furthermore, in the above embodiment, the line speed can be added as one of the manipulated variables.

As is clear from the above examples, according to the present invention,
When the measured quantities including the controlled quantities C and D of the foam insulated wire extrusion line as the controlled object fluctuate due to any of a plurality of manipulated variables, the manipulated variables are adjusted so that the controlled variables are adjusted to their target values. For control, a predetermined manipulated variable is controlled in proportion to the line speed, and an integral action is performed on each manipulated variable obtained from the difference between the controlled variable and the target value, and the integral action is applied to each manipulated variable. Therefore, each manipulated variable performs its function mutually and independently, and even when there is a disturbance, multivariable control is performed so that each controlled variable approaches the target value, and the desired C and D are maintained from the rise of the line speed. It is possible to manufacture high-quality foam insulated wires with

In addition, this control system includes feedforward operation and (
or) by performing a feedbank operation;
Response is improved and stability is increased.

Furthermore, by applying the line speed to the control system, it is possible to manufacture wires with C and D within the specifications even when the line speed increases, preventing the generation of non-standard products, that is, scraps, and improving the -stopping strength. can do.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of an extrusion line for foam insulated wire as a control target, Figures 3 and 4 are partial explanatory diagrams of an extruder installed in the line, and Figures 5 and 6 are explanatory diagrams of a line for extruding foam insulated wires as a control target. A block diagram of the automatic control system to which the invention is applied, FIG. 7 shows an operation flowchart of the system. 10 ・・・・・・・・・Extrusion line Y1~Y2・
...Controlled amount Y, -Y, ...Measurement amount YLs ......Line speed U1 to U6.
...Manipulated amount YR, ~YR2...Target value ε1-ε2...Difference U between control amount and target value! c, ~
U'c6... Operation variable 13... Core wire 16... Preheater 17...
......Extruder 19...Cylinder 20...Screw 21...
・・・・・・Crosshead 28・・・・・・・・・・・・
・Movable coolers 23-3 to 4...Cylinder heaters 24-1 to 2...Crosshead heater Agent Patent attorney Moritani-Yu #77 Amendment to figure procedure (voluntary) Commissioner of the Japan Patent Office Kazu Wakasugi Husband 1. Indication of the case Patent application No. 57-40543 2. Name of the invention Extrusion line control method for foam insulated wire 2.3. Relationship with the case of the person making the amendment Patent applicant Katsuhisa Furuta (and one other person) 4. Agent address: 3-9-5 Kyodo Building, Nihonbashi Honmachi, Chuo-ku, Tokyo 103 (Shinhonmachi serial number, each column and drawing 6, Amendment) Contents (+) Add the following statement between line IO and line 11 on page 24 of the specification 6 ``Below is a specific example of the control method of the present invention. <Specific example> High density polyethylene [Product name: )X Izzex 5300
E, Mitsui Petrochemical, d = 0.95゜M, I
, =o:4]too) and 0.5 parts by weight of a chemical blowing agent azodicarbonamide, a pellet-like composition was prepared consisting of a chemically foamed polyethylene compound. Using an extruder with a cylinder diameter of 65 mm as shown in Figures 1 to 4, initially, each cylinder temperature C1 = 155 °C C2 =
The temperature was raised to 175°C, C3 = 190°C, C4 = 200°C, crosshead humidity C6 = 200°C, and the composition was fed from the hopper 18 to the extruder, and a constant voltage was applied to the preheated temperature of 0. A core wire of 4 φ was continuously fed to the crosshead of the extruder. At this time, resin temperature C3 at the crosshead = 205°C, resin pressure P = 500 kg/a
It was J. Set the target value of the outer diameter of the extrusion coated wire to 0.
．． 580-φ, and the target value of capacitance was set to 300PF/m. Depending on the line speed YLS, controller C
Use R to control the screw rotation speed and preheater voltage, as well as adjust the outer diameter of the wire. Through the preheater applied voltage, extruder screw rotation speed, each cylinder heater voltage, cross eight 1-heater small. Multivariable control is performed at 1f to obtain both of the above target values by manipulating pressure and moving distance of the moving water tank from the crosshead.
1. The results are shown in Figure 8. In the same figure, one of the operating companies according to Con I and Roller CR, that is, the same number of screw rotations, is also shown. ReD#, line speed Y
l-S was changed to I-1, the line speed was made constant at point a, control of the controller CR and CP IJ was started, and the line speed was increased to l2 again at point b. H reaching steady line speed Yr-s o from 0 point
'1. Even in the l; edge section, both the diameter ([]) and electrostatic capacitance 0) could be adjusted to the 11 target value described in i;1, and a foamed polyethylene electric wire with high Il+ quality could be manufactured. ” (2) On page 25, the bottom line “indicates” is corrected to “Figure 8 shows the line speed and setting [ ] standard values according to the method, and their control result values.” (3) In the drawing, Add 8 figures.

Claims (1)

[Claims] 1. A foamed insulating composition containing a polyolefin resin and a blowing agent is supplied to an extruder, and the composition is applied onto a core wire that is continuously fed to the extruder until the blowing agent is decomposed. In an extrusion line control system for foam insulated wire, the outer diameter and capacitance of the foamed insulator are controlled to predetermined values by seeding the extrusion liquid at a temperature higher than that temperature and then passing it through a cooler. a plurality of controlled variables, such as capacitance, and state variables that influence said controlled variables, such as cylinder temperature, crosshead temperature, tree 11 temperature in the head, and resin pressure of the extruder; Quantitative values include the line speed of the extrusion line, the voltage of a break heater provided before the extruder, the screw rotation speed of the extruder, the cylinder heater voltage, the cross-rad heater voltage, and the moving distance of the cooler. In controlling the manipulated variable so that the controlled variable is adjusted to its target value when the controlled variable fluctuates in a predetermined correlation due to a plurality of manipulated variables, Of these, manipulated variables such as screw rotation speed and preheater voltage are controlled in accordance with the line speed, and outputs obtained by performing integral operations on each manipulated variable obtained from the difference between the target value and the controlled variable are calculated as each manipulated variable. An extrusion line control system for foam insulated wire, characterized by: 2. The control method according to claim 1, wherein an output obtained by performing a feedback operation on a plurality of measured quantities including the controlled quantity is applied to the manipulated quantity. 3. The control method according to claim 1 or 2, characterized in that an output obtained by performing a feedforward operation to the target value is applied to the operation lid. 4. Claim 3, characterized in that the integral operation is stopped when the sum output of the output Uc - the output UF + the output UN supplied to the manipulated variable exceeds a predetermined range. Control method described. 5. The control method according to claim 1 or 2, wherein an initial value of the integral operation is set in accordance with the measured quantity. 6. The control method according to claim 1, wherein the manipulated variable and the integral operation are obtained by linear processing. 7. The control method according to claim 1, wherein the manipulated variable includes dynamic compensation. 8. The control method according to claim 2, wherein the feedback operation is obtained by linear processing. 9. The control method according to claim 2, wherein the feedback operation includes dynamic compensation. 10. The feedforward operation is performed by linear processing.
The control method according to claim 3, characterized in that C is obtained. 11. The control method according to claim 3, wherein the feedforward operation includes dynamic compensation.