JPH03216920A - Control device for metallic wire coating equipment - Google Patents

Abstract

PURPOSE:To improve the yield of a metallic wire coating process by obtaining real time information on various parameters on the basis of measured amount, the parameters of which are so-called process constants, especially during a start-up period in which the initial speed of a takeup machine is raised to a specified value. CONSTITUTION:A parameter monitoring means monitors even during the start-up period of a metallic wire coating equipment by calculating the changes in parameters related to the physical property values of an insulator composition from the detected values of the outer diameter and the capacitance of the insulator composition and the response characteristic of the equipment. Then a setting value correction means corrects the operation amount on the basis of the changes in the monitored parameters. At the same time, a resin temperature control means controls the heating temperature of the insulator composition according to the estimated foaming rate. Because the optimum correction of the operation amount of the equipment is possible in this way even during the start-up period, the outer diameter and the capacitance of the insulator composition becomes on gauge immediately after the start-up period of the equipment during which the takeup speed of the takeup machine reaches a specified value. Thus the yield of the process is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a metal wire coating equipment for manufacturing a coated wire by coating a metal wire with an insulating composition made of a foamed metal resin, and more specifically relates to relates to a control device for adjusting the finished outer diameter and capacitance of the coated wire with high precision. [Prior Art] The coated wire manufactured by the above-mentioned metal wire coating equipment is used as a communication means of telephone equipment and for general electrical equipment, but its electrical characteristics include capacitance (μF /
m) and the finished dimensions of the outer diameter (μm) are required to be highly accurate.

On the other hand, from the viewpoint of productivity, a high withdrawal speed of coated wire is required, and 20% per minute is required in a short time even during start-up.
Start up to a take-up speed of 00m or more? It is required that the finished outside diameter and capacitance of the coated wire fall within the allowable accuracy immediately after startup. A wire sheathing facility (1111) is shown in FIG. 1 as an example of the metal wire sheathing facility described above. The core wire 4a is supplied to the annealer 1l and annealed.Meanwhile, a polyethylene resin, which is an example of a synthetic resin, and an organic foaming agent are supplied to an extruder 3, and a screw installed in a cylinder (not shown) of the extruder 3 is supplied. (not shown) is press-fitted into the crosshead 3a at the tip of the cylinder.
It is heated to a predetermined temperature that is higher than the decomposition temperature of the organic blowing agent by a heater (indicated by Hl in FIG. 2) disposed at a. Furthermore, the core wire 4a maintained at an appropriate temperature is guided to the crosshead 3. The polyethylene resin is coated along the inner shape of the wire to form a covered wire 4. Then, the covered wire 4 is picked up in the pulling direction (arrow F) by a subsequent pulling machine 9, immersed in water in a water cooling tank 6, cooled and solidified, and then its capacitance is measured by a capacitance meter. Ru. Next, the outer diameter of the M electric wire 4 is measured by an outer diameter meter 8.

Therefore, in the electric wire coating equipment 1, the screw rotation speed, etc. of the extruder 3 have conventionally been controlled in proportion to the take-up speed V of the take-off machine 9 in order to obtain the desired capacitance and outer diameter. The capacitance of the covered wire 4 was adjusted based on the measured value by using the mobile cooling tank 5 and moving the water cooling tank 6 in the taking direction. That is, by changing the distance between the crosshead 3a and the water cooling tank 6, the time from coating the polyethylene resin to cooling solidification can be adjusted, and by controlling the degree of foaming of the polyethylene resin, the adjustment can be made. It will be done. Further, the outer diameter of the covered wire 4 was adjusted by manually changing the screw rotation speed of the extruder 3 and the set temperature of the extruder 3 based on the actual measurement value.

The graph in FIG. 7 shows the results of controlling the finished outer diameter D and capacitance C of the coated wire 4 using the conventional control device for the wire sheathing installation II. According to this, the screw rotation speed N of the extruder 3 is not controlled when the equipment is started up. Then, the finished outer diameter D and the capacitance 1
The value of c is not yet in an on-gauge state when the above-mentioned Yumitori speed V reaches the steady state level v0, but shows a behavior in which it settles down to the target value after a while from that point. (Problem to be Solved by the Invention) However, in the conventional control as described above, when the mobile cooling tank 5 is moved, it is natural that the capacitance changes, but at the same time, the outer diameter also changes. Therefore, it is not possible to control the capacitance and the outer diameter D at the same time.Furthermore, such adjustment of the characteristics of the covered wire 4 is done manually, but originally human judgment was based on experience. However, it is not possible to accurately recognize the state of the process and perform it in real time and comprehensively.Therefore, it has been extremely difficult to independently control the capacitance and outer diameter. In particular, it was not possible to start up the equipment while controlling all the characteristics of the covering voltage vA4, and the characteristics had to be adjusted after startup.Therefore, at the time of startup, the characteristics were within the allowable range. It took a long time to reach on-gauge, resulting in poor yield.

Therefore, the object of the present invention is a metal wire of 17 m!
Various parameters, which are the so-called process constants of the process, are grasped in real time based on the above-mentioned measured quantities, especially at the time of startup to increase the speed of the pulling machine from the initial speed to a predetermined speed, and the set values of the manipulated variables are set according to the parameters. It is an object of the present invention to provide a control device for metal wire coating equipment that improves yield and has high control responsiveness during steady state by optimally resetting.

(Means for Solving the Problems) In order to achieve the above object, the main means adopted by the present invention is to supply an insulating composition made of a foamed synthetic resin to an extruder, and to continuously supply the insulating composition to the extruder. control of the metal wire coating equipment, in which the insulating composition is coated by extrusion at a temperature higher than the foaming temperature of the synthetic resin on the metal wire supplied to the insulator composition, and then cooled and solidified in a cooler, and the outer diameter and capacitance of the insulating composition are controlled to predetermined values; In the apparatus, a parameter monitoring means for calculating and monitoring changes in parameters related to physical property values of the insulating composition and response physical properties of the equipment from detected values of the outer diameter and capacitance of the insulating composition at that time; a set value modifying means for modifying a set value of the operation amount of the equipment based on a change in the parameter monitored by the parameter monitoring means; This is a control device for metal wire coating equipment, comprising a resin temperature control means for heating and controlling the temperature of a body composition. (Function) According to the present invention, even when starting up the metal wire coating equipment,
A parameter monitoring means calculates and monitors changes in parameters related to physical property values of the insulator composition and response characteristics of the equipment from the detected values of the outer diameter and capacitance of the insulator composition. Subsequently, the setting correction means corrects the operation amount of the equipment, such as the setting value of the extruder's screener rotation speed, etc., based on the changes in the monitored parameters. At the same time, the resin temperature control means adjusts the outer diameter of the insulating composition according to the estimated foaming rate and heats the temperature of the insulating composition so as to maintain the control 11 on the safe side. Control. In this way, the device of the present invention can grasp parameters that are process constants in real time based on the measured amount of insulating composition even when the device is started up, and can optimally correct the operating amount of the device. Immediately after startup when the take-up speed reaches a predetermined speed, the outer diameter and capacitance of the insulator composition become on-gauge within the permissible range. Thereby, the yield can be improved. Further, the device of the present invention can follow even if the start-up speed is increased, so that the start-up time can be shortened.

(Examples) Hereinafter, examples embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention. Here, FIG. 1 is a block diagram showing a wire coating equipment according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control system by a control device of the wire covering equipment, and FIG. 3 is a block diagram showing the amount of parameter correction. Fig. 4 is a flowchart showing a processing procedure by the parameter monitoring means of the control device, and Fig. 5 is a control example of the control device in which the screw rotation speed of the extruder is feedback-controlled based on the control device. Fig. 6 is a flowchart showing the processing procedure according to the method, and Fig. 6 is a graph showing the behavior of the operating factors and control factors of the wire coating equipment. In the following description, the same reference numerals will be used for elements common to the wire sheathing equipment 1 shown in FIG. 1 described in the prior art section, and the description thereof will be omitted. Furthermore, the following examples are merely specific examples of the present invention, and are not intended to limit the technical scope of the present invention.

In the control device 2 of the electric wire sheathing equipment 1 according to this embodiment, as shown in FIG.
. , take-up speed ■, 6f+ foaming rate P of polyethylene resin
0 is given to the meter electronics device 13, which has the outer diameter D. ．． Depending on the take-up speed Vret, the manipulated variables such as screw rotation speed N, take-up speed V, and mobile cooling tank 5 are determined.
The amount of movement l is determined by the motor M for driving the screw of the extruder 3.
1. Motor M2 for driving the mobile cooling tank. It is output to Moke M3 for driving the take-up machine 9. The control device 2 then measures the measured quantities, such as capacitance C°, outer diameter D°, etc. of the covered wire 4. Control is performed by incorporating the screw rotation speed N° and take-up speed V°, and the amount of correction of the set value of the manipulated variable is ΔN1 Δ! ．．
ΔV is calculated and the original set values of screw rotation speed N, take-up speed V. In addition to the moving distance Ml, new set values are output to the motors M+, M3, and M2, respectively. Further, to the heater H, a correction amount Δθ related to the temperature of the crosshead 3a of the extruder 3 is added to the original set temperature θ.

A specific example of the apparatus of this embodiment will be explained below.

Generally, the screw rotation speed N of the extruder 3 at time t
(t) is expressed by the following equation (1), where V(1) is the collection speed by the collection machine 9. π...(1) D0 - Target finished outer diameter P. =Target foaming rate d - Target core wire diameter α2 is the viscosity coefficient of the resin and the propulsion flow coefficient of the screw. It is a function of the differential pressure in the metering zone, etc. π Here, if A1 is set, A is a parameter determined by the temperature of the extruder 34α2, the differential pressure in the metering zone, etc. Since these values can be determined empirically, if the value of the parameter A is determined in advance, the target finished outer diameter D0, the target core wire diameter d
．． It can be seen that the screw rotation speed N (t) and the take-up speed v (t) are in a proportional relationship, with the target foaming rate P0 being a proportional constant. On the other hand, since the parameter A is a parameter that includes physical property values, it varies not only depending on the physical properties of the resin but also depending on the environmental temperature and pressure conditions.
Therefore, even if the setting conditions for the equipment are the same, it is determined that the parameter A will change until the equipment becomes sufficiently stable.

Now, at [time], the meter and electrical equipment 13
Assume that the take-up speed v (t) and the screw rotation speed N(1) are output from . As a result, the pulling machine 9 starts driving, and the covered electric wire 4 is pulled in the pulling direction (arrow F). Therefore, the coating voltage &lI4 is changed from time t to T0
Seconds later, the capacitance C° is measured by a capacitance meter, and T seconds after time t, the finished outer diameter D′ is measured.
That is, at time @1, the core wire 4a is coated with polyethylene resin in the extruder 3 to form the covered wire 4, and at time t
+T0, the capacitance C''' of the covered wire 4 changes at time t
+T, its finished outer diameter D° is measured. Therefore, the delay time caused by the difference in measurement time is corrected, and as described below, the core wire 4 is transferred from the extruder 3 to the core wire 4 at time t.
The foaming rate Pt of the polyethylene resin coated on a must be estimated.

First, the well-known Wagner's formula is shown in the following equation (2). Here, C - capacitance D - finished outer diameter d - core wire diameter P - foaming rate BS (P) dielectric constant of polyethylene resin at foaming rate P F - Farasod On the other hand, the dielectric constant in formula (2) Es (p) is the following (3)
It is expressed by the formula. c+eP Here, E5 (0) - relative dielectric constant a=2Es (0)+1 b1~2 (Es (0) c=2Es (0)+1 e=Es (0) -1.

Note that the dielectric constant Es(0) is a specific value, and is approximately 2.3 here.

Therefore, in order to obtain the estimated foaming rate P't at time t, the finished outer diameter D''1*Tl and the capacitance C',. Es
(P), the dielectric constant ES (P
) to (3), the corresponding estimated foaming rate P is uniquely determined by equation (3).
″, can be calculated.

Substituting the estimated foaming rate P' into equation (1) again, and assuming that the actually measured screw rotation speed and take-up speed at time E are N' (t) and v (t), respectively, the following (
4) An equation is derived.

N"(t)=A'((D'L.TI)"
-d")X(1p't)v'(t)...(4)
Here, the set value constant K = N (t)/v (t
), the actual measured value constant K' - N'' (t)/v
'(t) and Equation (5) below is derived.

That is, K = A- (D."d") (1-P.)
K' = A' ・ ((D” t.t+)!
-dx )x (1-P"L), A'/A= (K'/K)(D6"-d")(1
-PG )/i([o't.y+)"-a" )(t
-p”t)]...(5) This indicates the parameter ratio of the actual measurement base to the setting base, and the parameter ratio A'
/A determines the correction amount ΔN for resetting the screw rotation speed N (t) to an appropriate value. The correction amount ΔN is expressed by the following equation (6).

The correction amount ΔN of the screw rotation speed (1) is, as shown in the block diagram of FIG.
ft) is given positive feedback. At this time, since the amount of positive feedback is held (0th order), equation (6) uses the Laplace operator S based on Laplace transform, (where A'/All is the transfer function G and K/S is the transfer function This leads to equation (7) where G2 is assumed. This equation (7) naturally holds true when the mobile cooling tank 5 is not moving, but it also holds true even when the mobile cooling tank 5 moves. This will be explained below.

Here, it is assumed that when the mobile cooling tank 5 moves by a moving distance Δl, the foaming rate of the polyethylene resin changes by ΔP″, and the finished outer diameter changes by ΔD°. Since the mass of the resin is conserved, that is, the total differential of the formula ((o゜)z -d")(1-P') becomes 0, so the formula δf((D")"-a")( 1-P")l=0 is given, and from this, ((D")"-d")ΔP゜+2D"(1-P")ΔD". =0 relationship is derived.

That is, the parameter ratio A/A' when the mobile cooling tank 5 moves by a moving distance Δ2 is expressed by the following equation (8), A/A' =
(K' /K)- (Do"-d") (1-PG
/ ( ((D”−ΔD゜,)!1d!}X (1−
(P" - ΔP"I)} = (K' /K)
・(poz-a”)(t-po)/(((D”
)"-d") (1-P")+δ (((D
” )Z −d” )(IP” )l)1(K'/K
)-(Do”d”)(t-p.)/(((D”
)"-d")(1-P'))...(8).

Therefore, the parameter ratio A'/A is equal to
It is unrelated to the movement of , and is a function of the finished outer diameter D° and the foaming rate P° estimated from the actual measurements. As a result, the above equation (7) holds true regardless of the movement of the mobile cooling tank 5. Therefore, in the present embodiment, the parameter ratio A'/A, which changes from moment to moment, is monitored, and the set value is optimized based on the parameter ratio A'/A at that time.

Furthermore, since the actual measured values include unavoidable errors, the actual measured values are sampled n times and the value of the variance ratio calculated at this time is (A' / A) = N = 1..., n). . Furthermore, among the parameter ratios (A'/A)i, the maximum value MAX ((A'/A)i(i=i...n))
and minimum value MIN((A'/A)=, (i=1,・
・・・． n)} was removed as a countermeasure for errors related to the actual measured values. In this way, if the parameter ratios excluding the maximum and minimum values are ai, . . . am-2, the following equation (9) can be obtained.

That is, when actually correcting the set value, the average parameter ratio A'/A obtained from equation (9) is given to equation (6) described above. At this time, the parameter ratio (
The constant K shown in equation (5) used when calculating A'/A)i has a value of O≦K≦1. Note that if the constant K is set to 0, the control method will be the same as before. The processing procedure for appropriately correcting the set values for the process while accurately monitoring the process parameters from time to time will be described below with reference to the flowchart of FIG. 4.

First, a sampling start time for sampling the parameter ratio (A'/A)i is set (S1
). Usually, the sampling start time is when the core wire 4 is coated with polyethylene resin. Therefore, the finished dimension D'''a and capacitance C゜,.a of the covered wire 4 are actually measured, and the parameter ratio (A'/A) at time t is determined via the estimated foaming rate P''. (S2), and the calculation of the parameter ratio (A'/A) is repeatedly executed n times at predetermined time intervals.

Then, the average parameter ratio (A'/A)b before the set value is corrected is determined from the n parameter ratios (A'/A)i determined in step S2 (S3). This reduces the error in the sampled parameter ratio (A'/A) as described above. Therefore, based on the average parameter ratio (TfA)b, for example, a correction amount ΔN of the screw rotation speed N set in the extruder 3 is calculated, and the correction amount ΔN is positively fed back to the original setting value. (S4
) Then, in order to track the change in the parameter due to the process behavior after the setting value modification, the parameter ratio (A'/A).
is repeatedly calculated for a predetermined time T (S5), and the average parameter ratio (A'/A)a at that time is calculated as a value based on the control result after setting correction (S6).

Subsequently, in step S7, it is determined whether or not there is an effect of correcting the set value by positive feedback of the correction amount ΔN. That is,
Absolute value of parameter correction amount before setting value correction + (A' /
A) The value of b - tl and the absolute value of the parameter correction amount after correction {](A'/A) a-1l are compared. At this time, the set offset value μ is set for the amount of variation correction after the correction. is taken into account.

Here, if the amount of parameter modification before the modification is smaller than the parameter modification amount after modification, it is considered that there was no effect of modifying the set value due to the influence of noise, etc., and the number of samplings is increased to 2n times in step S8. The parameter ratio (A'/A)i is sampled again. From the average parameter ratio (A'/A) calculated based on this sampling result, the re-correction amount Δ of the screw rotation speed N is calculated.
N, is obtained (39-SIO). Here, the ΔN,
is the previous correction amount ΔN and the direction of each correction vector,
That is, the positive and negative signs are checked (Sll). Therefore, if the direction of each correction vector is different, it is determined that the influence of noise etc. can be eliminated by increasing the number of samplings, and the positive feedback amount is obtained by adding the re-correction amount ΔN to the screw rotation speed N, which is the set value. is given (S12).
On the other hand, if the corrected hectares are in the same direction, it is determined that the setting value correction has no effect, and the correction amount ΔN is canceled (Sl3).

By the way, when it is determined in step S7 that the correction of the setting value in step S4 was effective, a positive feedback amount of correction amount ΔN is continuously given to the screw rotation speed N as in step S4 (Sl /I).

In this way, the moment-by-moment change in parameter A is accurately grasped, and the set value of the manipulated variable is appropriately corrected based on it.

Here, since the parameter A is accurately grasped and appropriately corrected, if the target foaming rate P0 of the polyethylene resin and the actually measured foaming rate P゜, match, the actually measured covered wire Finished outer diameter of 4 D゜゜, l
will match the target finished outer diameter D0. However, at this time, the heating temperature θ of the polyethylene resin must be set to an appropriate temperature. This is because, if the heating temperature θ is too high, the polyethylene resin will over-foam, making control by movement of the mobile cooling tank 5 impossible. Furthermore, it takes a long time to cool the polyethylene resin, which hinders the production of coated wires 4 of stable quality. By setting the heating temperature θ to an appropriate temperature, the parameter 8, especially the parameter related to the physical property value of the polyethylene resin, becomes a unique value. In order to accurately set the temperature θ to an appropriate temperature, a processing step is provided to correct the temperature from a lower value on the safe side to an appropriate temperature based on the foaming rate P° estimated at each time point. Moreover, in the apparatus of this embodiment, when the wire sheathing WI1 is in the middle of being started up, the foaming rate P@, is identified at each point in time during the start-up in order to improve the yield of the covered wire 4. ing. In this state, the mobile cooling tank 5 is in its original position and has not yet been controlled. Figure 5 shows the procedure for correcting the heating temperature θ of polyethylene resin as described above. Here, the heating temperature θ is controlled using the heater H1 disposed at the crosshead 3a, which has the smallest response delay. The heating temperature θ is corrected according to the deviation P'' - P0 of the estimated foaming rate P'' from the target foaming rate P0. That is, the heating temperature θ is equal to the deviation P°-P. Threshold value δ1 and threshold value δk (however, δ1 minus δ2) set for
are compared in steps S20 and S24, and if the deviation P''tPo is between the respective darkness values, i.e.
If Po-δ2≦Pa,≦P0+δ1, the heating temperature θ is determined to be appropriate, and the temperature of the crosshead 3a is not changed and the set temperature at that time is maintained (32B), while P "c<Pa-δ," it is determined that the set temperature of the crosshead 3a is low, and the set temperature is adjusted by the correction amount Δ based on the following equation (10).
The value is corrected and set higher by θ (S21 to S23).

Δθ - μ direct ω-I (p0-p”.) (10) Here, μ1 is the gain. Also, ω is the sensitivity of the foaming rate to temperature, and the sensitivity at the target heating temperature θ. ω is defined as the following equation.

On the other hand, if P″,>P0+δ is small, it is determined that there is a high risk of over-foaming of the polyethylene resin, and the set heating temperature is corrected as soon as possible based on the following equation (11). (325-S27).

Δθ−μ2ω−′ (P′ −P.)−(1 1) As a matter of course, in the processing procedure for correcting the set heating temperature, 1Δθ1≦θ. Limits (S22, S26) with a constraint of 18 are given. Further, the above-mentioned unique values δ,, δ2μ1, μ2, ω are calculated in advance and stored as a table in the memory (not shown) of the control device 2. The finished outer diameter D of the coated wire 4 is determined by using the control device 2 for wire coating installation Ol1 as described above. Control capacitance C12i
The results are shown in the graph in Figure 6. According to this, the change in the parameter A is monitored even when the equipment is started up until the take-up speed V of the take-off machine 9 is increased to the steady take-up speed v0, and the change in the parameter A is monitored based on the parameter ratio A'/A. It is observed that the screw rotation speed N of the extruder 3 has been modified. At this time, the heating temperature θ of the polyethylene resin is also adjusted to the normal temperature.

As a result, the finished outer diameter D and electrostatic capacity C of the covered wire 4 are determined.
are the respective target values D0 and C. when the equipment reaches a steady state. The on-gauge value is within the permissible range. Therefore, unlike conventional systems, there is no problem that even when the equipment reaches a steady state, the finished outer diameter D and capacitance C do not reach the on-gauge values. Since the apparatus of this embodiment also has excellent responsiveness during start-up, it is possible to increase the number of take-up machines 9 at the time of start-up, and the start-up time can be shortened. the result,
The yield of the covered electric wire 4 is improved.

Furthermore, since changes in the parameter A are regularly monitored, it goes without saying that the finished outer diameter D and capacitance C can be managed with high precision even during regular equipment operation. .

〔Effect of the invention〕

As described above, the present invention supplies an insulating composition made of a foamed synthetic resin to an extruder, and extrudes and coats the metal wire continuously supplied to the extruder at a temperature higher than the foaming temperature of the synthetic resin. In a control device for metal wire coating equipment, which controls the outer diameter and capacitance of the insulator composition to predetermined values, the insulator composition is then cooled and solidified in a cooler, and the physical property values of the insulator composition and the response physical properties of the equipment are controlled. parameter monitoring means for calculating and monitoring changes in parameters related to the outer diameter and capacitance of the insulator composition at that time from detected values of the outer diameter and capacitance of the insulator composition; and operating the equipment based on changes in the parameters monitored by the parameter monitoring means. A setting direct correction means for correcting a set value of the amount, and a resin temperature control means for heating and controlling the temperature of the insulator composition according to the detected value of the outer diameter and capacitance of the insulator composition. Since this is a control device for metal wire coating equipment, it can grasp changes in process parameters in real time based on detected values that serve as control targets, and optimally correct the operating amount of the equipment. Therefore, it is possible to follow the process behavior not only during normal operation but also when starting up the equipment. As a result, the detected value becomes on-gauge immediately after the equipment is started up. As a result, yield is improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a wire coating equipment according to an embodiment of the present invention, Fig. 2 is a block diagram showing a control system by a control device of the same IT line coating equipment, and Fig. 3 is a block diagram showing a control system based on the amount of parameter correction. Fig. 4 is a flowchart showing a processing procedure by the parameter monitoring means of the control device, and Fig. 5 is a block diagram showing a control example in which the screw rotation speed of the extruder is feedback controlled. A graph showing the processing procedure, Fig. 6 is a graph showing the behavior of operating factors and control factors of the wire coating equipment, Fig. 7 is a graph showing the behavior of operating factors and control factors of the wire coating equipment.
The figure is a graph showing the behavior of operating factors and control factors of conventional wire coating equipment, which is an example of the background of the present invention. [Explanation of symbols] 1...Wire coating equipment 3...Extruder 4...Coated wire 6...Water cooling tank 8...Outer diameter make 13...Meter and electrical equipment 2...Control device 3a... Crosshead 5... Mobile cooling tank 7... Capacitance meter 9... Taking machine

Claims (1)

[Claims] (1) An insulating composition made of a foamed synthetic resin is supplied to an extruder, extruded and coated on a metal wire that is continuously supplied to the extruder at a temperature higher than the foaming temperature of the synthetic resin, and then cooled by a cooler. In a control device for metal wire coating equipment that solidifies and controls the outer diameter and capacitance of the insulator composition to predetermined values, A parameter monitoring means that calculates and monitors the detected values of the outer diameter and capacitance of the insulator composition at that time, and corrects the set value of the operation amount of the equipment based on the change in the parameter monitored by the parameter monitoring means. and resin temperature control means for heating and controlling the temperature of the insulator composition according to the detected values of the outer diameter and capacitance of the insulator composition. Control device for wire coating equipment.