JPS58109351A - Tension controller - Google Patents

Abstract

PURPOSE:To efficiently utilize the torque of an electric motor, by controlling the field flux and armature current of the motor as functions of the speed of a line and making the field flux large enough to increase the tension of a strip. CONSTITUTION:It is made possible that the field flux and armature current of a DC motor 3 for driving tension bridle rolls 1 are controlled as functions of the speed (v) of a line. Even if the speed (v) of the line is low, the field flux is made large enough to increase the tension T of a strip 2. According to this constitution, the torque of the motor 3 is very efficiently utilized depending on the speed (v) of the line.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement in a tension control device for a tension pry roll lK driving DC motor that applies a predetermined tension to a processing material such as a string material.

TECHNICAL BACKGROUND OF THE INVENTION Conventionally, as a tension control method for a tensile pry roll that applies a predetermined pressure to a processed material such as IJZZO material, the field magnetic flux of a DC motor is fixed and the armature current of the motor is adjusted to the tension. A tension control method is employed to obtain a desired tension by controlling it in proportion to a reference.

This method can be explained using the following formula.

First, the following equation holds true for a DC motor.

τ=[I Xφ×! ...(
1) Here, τ: electric motor torque, Kl: constant.

φ: Field magnetic flux, I: Armature current.

Further, the motor torque τ is expressed by the following equation.

τ=, XTXd... (2) Here, T is the tension applied to the material.

d: Roll diameter of tension pry roll.

K1: Constant.

According to the above equations (1) and (2), the tension T is as follows.

Next, in equation (3), since the roll diameter d of the tension ply roll is constant, by fixing the field magnetic flux φ, the tension force applied to the strip material and the armature current I are proportional. Therefore, a desired tension can be obtained by controlling the electric current I in proportion to the tension reference.

FIG. 1 shows the configuration of a tension control device for a conventional tension pry roll of this type. In the figure, 1 is a tension pry roll for applying a predetermined tension to the strip material 2, 3 is a DC motor for driving the roll 1, 4 is a tension reference device that outputs a tension reference T1 for the strip material 2, and 5 is a line An acceleration/deceleration compensator calculates and outputs the motor torque T2 required during acceleration/deceleration to eliminate tension fluctuations in the strip material 2 due to line acceleration/deceleration; 6 is the output 'rl,' of the tension reference device 4 and the acceleration/deceleration compensator 5; r1
An adder for adding , and an armature current control device 7 for controlling the armature current of the DC motor 3 to a magnitude corresponding to the output of the adder 6 .

In the tension control device having such a configuration, a desired tension is obtained by fixing the field magnetic flux and controlling the armature current so that it is proportional to the tension reference.

Problems with the Background Art The conventional tension control device described above has the following problems. The back electromotive force E of the DC motor is expressed by the following equation.

K=Kl Xφ×ro...
(4) Here, 11: Motor rotation speed.

Kri: Constant.

Further, the rotation speed n of the DC motor 30 for driving the tension pry roll 1 is expressed by the following equation.

a=Y/πd...(5) Here, Yani line speed.

Substituting this equation (5) into equation (4), we get E=Xφ×
τ7 (6) In this equation (6), the field magnetic flux φ is fixed and the roll diameter d of the tension pry roll 1 is constant, so the equation (6) can be expressed as the following equation.

K= to 4 Xν...(7) thisζ
Then, K4 = $Xφ×''-two constants.

πd And, as can be seen from equation (7), the back electromotive force EFi of the DC motor 3 is proportional to the line speed, and the line speed! When becomes the maximum line speed -1X, the back electromotive force E has the maximum value -
1! becomes. This company, line speed! This shows that the electric motor torque is not effectively utilized when the maximum line speed ttt v- is very low. In other words, the maximum torque that an electric motor can produce is:
This is only when the line speed τ reaches the maximum line speed vmax.

OBJECTS OF THE INVENTION The present invention was made in view of the above circumstances, and its purpose is to provide a tension control device that can effectively utilize motor torque in accordance with line speed.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention controls the field magnetic flux and armature current of a DC motor that drives a tension pry roll that applies a predetermined tension to a processing material such as a strip material as a function of line speed. , even when the line speed is low, the field magnetic flux is increased to increase the tension on the strip material.

Examples of the invention An embodiment of the present invention shown in the drawings will be described below.

FIG. 2 shows an example of the configuration of the tension control device according to the present invention.
The parts that are the same as those in FIG.

In the figure, 11 is a field flux reference calculation circuit that calculates the line speed τ and the possible field flux reference φ8, and 12 is a field flux reference calculation circuit that calculates the upper limit of the output φ of the field flux reference calculation circuit 11 to the maximum field The limiter 13 which limits and outputs the magnetic flux φwax is a field current control device that controls the field magnetic flux of the DC motor 3 to a magnitude corresponding to the output φ of the limiter 12. On the other hand, 14 is the above IJ mi, ter 1
A first divider 15 and 16 which divides the output φ of 2 by the maximum field magnetic flux 'm&X and outputs the result are the outputs from the tension reference device 4i and the acceleration/deceleration compensator 5, respectively. and T mushroom respectively by the output KlK of the first divider 14, and the respective outputs of this 0jl12 and the third divider 15 and 16 are divided by the output KlK of the first divider 14, respectively. The husband and wife input power to the adder σ.

In such a configuration, the field magnetic flux reference calculation circuit 11 and the limiter 12 calculate the field magnetic flux reference φ, which will be described below. From the above equation (6), the following equation is established.

5 v...(8) Here, K, = Yr, constant.

The field magnetic flux reference calculation circuit 11 calculates the following equation (9).

Finally, in Equation (9), the DC motor 3 can be used with the maximum back electromotive force Em, t, so a field magnetic flux reference φ that can be made stronger than the line speed V is calculated.

In addition, the output φ of the field magnetic flux reference calculation circuit 11 is adjusted by the limiter 12 to increase the maximum field magnetic flux of the DC motor 3,
! The upper limit is limited by .

The relationship between the output φ of the limiter 12 and the line speed τ is shown in Figure 3.

In Fig. 3, at the line speed νl''!!, the field magnetic flux reference φ can be set to the maximum field magnetic flux φm, and the maximum back electromotive force is 8 m1 when the line speed is up to `` '' vrnax.
Therefore, the field magnetic flux reference φ of the above equation (9) is used.

As can be seen from this figure, when the line speed ν is the maximum line speed −ax, the field magnetic flux φ becomes the number φ. Tsutshi,
In the conventional tension control device, the field magnetic flux φ is fixed, so in order to enable the tension pry roll 1 to operate at the maximum line speed t'wax t, the field magnetic flux φ is changed to φ.
・However, with this configuration, the field magnetic flux φ can be increased compared to the conventional tension control device, so (
As seen from equation (1), it is possible to increase the motor torque τ, and as shown from equation (3), it is possible to increase the tension T applied to the string material 2.

On the other hand, if the output φ of the limiter 12 is the field magnetic flux reference,
A field magnetic flux φ can be obtained by the field current control device 13. Further, the divider 14 performs division according to the following equation 01.

Kll”'φ／φmax ”'
αQ Then, the stritz tension reference T, which is the output of the tension reference device 4, is divided into the output K of the divider 14 in the divider 15.
By dividing by ll, the field magnetic flux φ is smaller than φ, and by multiplying it by 1, the tension on a constant strip material 2 is can get. Also, the output T! of the acceleration/deceleration compensator 5! Similarly to the tension reference 'rt, K11K is divided by DTs/Lt in the divider 16. Furthermore, the output Ts/Kt of each divider 15.16
The adder 6 adds t + Ts /Ktt, and the armature current control device 7 controls the armature current I to a magnitude corresponding to the output of the adder 6 to obtain a desired tension.

Therefore, with the above-described configuration, it is possible to control the field magnetic flux and armature current of the DC motor 3 that drives the tension ply roll 1 as a function of the line speed! Even when the line speed ν is low, the field magnetic flux is increased to increase the tension T on the strip material 2, and thus the torque of the motor 3 can be used very effectively in accordance with the line speed ν.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, as described in detail, an extremely reliable tension control device that can effectively utilize electric motor torque in accordance with line speed can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional tension control device, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing an example of the relationship between line speed and field magnetic flux. DESCRIPTION OF SYMBOLS 1... Tension pry roll, 2... Strip material, 3... DC motor, 4... Tension reference device,
5... Acceleration/deceleration compensator, 6... Adder, 1... Armature current control device, 11... Field magnetic flux reference calculation circuit,
12...Limiter, 13...Field current control device,
14.15.16...Divider. Figure 1 Figure 3

Claims (1)

[Claims] A DC motor drives a tension pry roll that applies a predetermined tension to processing materials such as nuts and plastics, a tension reference device outputs a tension reference for the processing material, and a tension reference device calculates the motor torque required during line acceleration and deceleration. an acceleration/deceleration compensator that outputs an acceleration/deceleration compensator, a field magnetic flux standard calculation circuit that calculates a field magnetic flux standard that can be strengthened based on the line speed, the roll diameter of the tension pry roll, and the maximum back electromotive force of the DC motor; A limiter that limits and sets the upper limit of the output of the field magnetic flux reference calculation circuit by the maximum field magnetic flux.
a field current control device that controls the field magnetic flux of the DC motor to a magnitude corresponding to the output of the limiter; and a first field current controller that divides the output of the limiter by the maximum field magnetic flux and outputs the result. a divider, second and third dividers that separately divide the outputs from the tension reference device and the acceleration/deceleration compensator by the outputs of the first divider; and an armature current control device for controlling the armature current of the DC motor to a magnitude corresponding to the addition output of the divider of No. 3.