JPS63242856A - Acceleration/deceleration control device for strip processing line - Google Patents

Abstract

PURPOSE:To utilize the effective torque of a motor to the maximum and control the optimum acceleration/deceleration rate by calculating the acceleration/ deceleration time in response to the difference between the necessary torque for a strip and the effective torque and setting the acceleration/deceleration rate in response to this acceleration/deceleration time. CONSTITUTION:When the tensile force is set based on the material, thickness, and width of a strip 30 and the line speed is set by a line speed setter 2, the actual reel coil diameter is recognized, and the torque necessary for the acceleration or deceleration and the effective torque of a motor are calculated. Next, the acceleration/deceleration time and the acceleration/deceleration rate of a payoff reel 16 and a bridle roll 17 respectively in response to the line speed and the torque are calculated, and a smaller value of either one is given to a speed directing unit 1 as the acceleration/deceleration rate. Accordingly, the strip 30 can be controlled at the acceleration/deceleration rate in response to the shortest acceleration/deceleration time, the time loss at acceleration/ deceleration is eliminated, and the loop quantity in a looper 31 facility can be reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to motor control for steel plants.

In particular, an acceleration/deceleration control device for a strip processing line suitable for controlling the speed of a strip wound on a reel by tension.

[Conventional technology]

Conventionally, a steel strip is fed into the line using a payoff reel, and the leading and trailing ends of the strip are processed using a shear, then welded to other strips using a welding machine, and the line is operated continuously at the line speed determined by the pre-drill roll. Various acceleration/deceleration control methods are used in strip processing lines to ensure strips of the required length, but it is common to control the acceleration/deceleration rate at a constant rate or by changing the settings of the operating system. It is. (Unexamined Japanese Patent Publication No. 51-
27626 and JP-A-53-47780) The acceleration/deceleration rate of line speed should be reflected in the planning stage to determine the motor from the forcing torque required for acceleration/deceleration time based on the maximum tension and maximum line speed. However, since the detailed specifications of the plant are not complete at that point, the acceleration/deceleration time is currently determined only after the detailed specifications have been decided. In the conventional method, the acceleration/deceleration time is controlled to be constant based on the maximum tension and the maximum line speed, that is, the acceleration/deceleration rate shown in the following formula is controlled to be constant.

a = Vmax, /T.

α: Acceleration/deceleration rate Vmax, : Maximum line speed mpm To: Time from maximum line speed to stop (acceleration/deceleration time) sec.

The advantage of controlling α to be constant is that the logic of the control device is simple.

However, in recent years, with the advancement of automation, the idea of improving cycle time and stop time accuracy to save product yield has come into focus.

The purpose of the present invention is to calculate the effective torque of the motor by calculating the actual tension of the strip, which varies greatly depending on the material, thickness, and width of the strip, and the required torque, which is determined by the reel tension value and coil diameter. An object of the present invention is to provide an acceleration/deceleration control device for a strip processing line that can be used to the maximum extent and control the optimum acceleration/deceleration rate.

[Means for solving problems]

An object of the present invention is to accelerate or decelerate the line speed of a strip in a strip processing line, which is equipped with a reel for feeding the strip into the line, a roll for determining the line speed of the line, and a looper for ensuring the required length of the strip. The acceleration/deceleration control device calculates the acceleration/deceleration time corresponding to the difference between the effective torque and the required torque obtained from the set tension of the strip, the moment of inertia of the reel, and the line speed, and calculates the acceleration/deceleration time corresponding to this acceleration/deceleration time. This is achieved by providing an acceleration/deceleration control device for a strip processing line, which is characterized by being provided with an acceleration/deceleration control mechanism that sets the acceleration/deceleration rate of the line.

[Effect]

According to the present invention, when an operator presets the set tension and line speed in the control device based on the material, thickness, width, etc. of the strip, the actual reel coil diameter is recognized and the torque required for acceleration/deceleration is determined. and the effective torque of the motor, and then calculate the acceleration/deceleration time and acceleration/deceleration rate of the payoff reel and priddle roll corresponding to the line speed and these torques, and the smaller value of the two is determined as the acceleration/deceleration rate. given to the command device.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 10.

As shown in FIG. 1, Nα1 and Nα2 payoff reels 16 feed the steel strip 30 into the line.
Then, the tip and rear ends of the strip 3o are processed with the shear 19, and welded with the strip 30 from Nα2 using the welding machine 2o.
The line speed determined by the priddle roll 17 is adjusted to the input equipment (
The line speed of the equipment from the payoff reel to the looper is continuously operated as a standard, and the looper equipment 18 is provided with a strip 30 of the required length for continuous operation of the central equipment during the welding process on the input side to maintain the line speed. In an acceleration/deceleration control device for a processing line that accelerates/decelerates, strip 3
The acceleration/deceleration time is calculated according to the difference between the effective torque and the required torque obtained from the respective values of the set tension of 0, the moment of inertia of the reel, and the line speed, and the acceleration/deceleration rate of the line is calculated according to this acceleration/deceleration time. This configuration includes an acceleration/deceleration control mechanism for setting.

In order to control the payoff reel at a constant tension, ACR
(AUTOMATIC CURRENT REGULAT
The electric motor 15 is controlled by the OR) control 11 and the thyristor converter 14. Nα1 and Nα2 payoff reels 16
are used alternately, so they are switched by the switch 10 according to the current command.

The current command for ACR~ is a combination of the following two.

1) Tension current command according to the set tension 42) Acceleration/deceleration forcing current command 5 Acceleration/deceleration current, that is, forcing current, changes depending on the moment of inertia GDz of the reel coil, the reel coil diameter, etc., so these can be set as payoffs. This is done by reel coil diameter calculation 6 and the above 1) and 2) are combined by adder 9.

The control of the priddle roll 17 is performed using ASR (AUTOMATIC5PEED) in order to keep the line speed constant.
REGULATOR) control 12 and thyristor converter 14
The electric motor 15 is controlled by.

The incoming line speed is set by the line speed setting device 2 and becomes an ASR command via the speed command device 1.

The position of the looper 31 is controlled to control the loop amount while keeping the tension constant. The looper tension current command 7 and the looper forcing current command 8 are converted to AC via an adder 9.
This becomes an R command.

In conventional control, the speed command device 1 controls the line speed setting at a constant rate, and the forcing of the payoff reel 16 and looper 31 is also calculated based on this constant acceleration/deceleration rate and commands the forcing current. However, in the present invention, in order to minimize the acceleration/deceleration time of the entry side equipment, the moment of inertia GD2. Calculate the acceleration/deceleration rate for uniform speed from the reel coil diameter and looper tension.

First, the tension setting of the strip will be explained with reference to FIGS. 3 to 7.

As shown in FIG. 3, the payoff reel tension, that is, the tension between the payoff reel and the priddle roll, is expressed with the board thickness as the horizontal axis and the board width as a parameter. As can be seen from this figure, the maximum tension (hmax, ) is the maximum tension T xmax at the maximum board width, and the tension tends to be determined based on a constant unit tension.

Similarly, FIG. 4 shows looper tension.

The tension borne by the pridle roll is the difference between the tension of the payoff reel and the looper, and this is shown in FIG.

Next, the required torque according to the tension is expressed by the following formula, which is illustrated in FIG. 6.

τT=T X (D/ 2) X (1/ Or) τT
: Tension torque T converted to motor shaft: Tension D = Diameter Gr: Reduction ratio On the other hand, motor torque τN, tension torque τT.

The following formula holds true between acceleration/deceleration forcing torque τF and friction torque B.

τF=τ, −(ττ± τ) This relationship is shown in FIG. As can be seen from this figure, the difference between the tension actually set with respect to the maximum tension torque becomes the forcing torque, and if this is used effectively, the shortest acceleration/deceleration time can be achieved.

The conventional method uses Tlmax in Fig. 3 and Tx in Fig. 4.
The acceleration/deceleration rate is determined based on max.

Next, the acceleration/deceleration control mechanism will be explained with reference to FIG. Calculate the payoff reel coil diameter by recognizing the moment of inertia GD6
Accordingly, the line speeds are input from the line speed setter 2 to the acceleration/deceleration rate setter 3, and acceleration/deceleration rate signals are given to the speed command device 1 so as to achieve the shortest acceleration/deceleration time for uniform speed.

Summarizing the above, the calculation process of the present invention will be explained with reference to FIG.

First, as a basic calculation, the rotational speed of the payoff reel and the priddle roll is determined. When accelerating, find the rotation speed from the target line speed or maximum line speed.

NP: Payoff reel rotation speed NB Nibrill roll rotation speed Grp: Payoff reel reduction ratio (fixed value) Gra Nibridle roll reduction ratio (fixed value) DP: Payoff reel coil diameter DB Nibrill 1 roll diameter (fixed value) Here, VE,
DP is variable data and is obtained from the line speed setting device 2 and payoff reel coil diameter calculation 6 shown in FIG.

Next, calculate the required torque for the set tension.

X 1 /G rB □, T = payoff reel tension torque τBT nibride roll tension torque TL nil-par tension On the other hand, the effective torque of the payoff reel and priddle roll motors is calculated by the following formula.

τPM: Payoff reel motor effective 1 - 18M nib bridle roll motor effective torque KWp: Includes overload capacity at payoff reel motor KW (fixed value) KWn Includes overload capacity at nib bridle roll motor KW (fixed value) However, When Np and NB are less than the rated rotation speed of the motor, use the rated rotation speed.

After basic calculations of equations 1), 2), and 3) above, acceleration/deceleration times are calculated using the values.

Tp=GDp"XNp/375X (τpM-(τBT
-τah)) TP: Payoff reel acceleration/deceleration time TB Nibridle roll acceleration/deceleration time GDp": Payoff reel moment of inertia GDB"Nibridle roll inertia moment (fixed value) τPL: Payoff reel friction torque (fixed value approximation) τB: Prydle Roll Friction Torque (Fixed Value Approximation) Here, GDp2 is variable data and is obtained from the payoff reel coil diameter calculation 6 shown in FIG.

Finally, the acceleration/deceleration rate is calculated so that the input equipment is at the same speed and acceleration/deceleration operation is possible. That is, VE/T
By comparing P and VE/TB and applying the smaller one as the acceleration/deceleration rate to the speed command device 1 shown in FIG. 1, the acceleration/deceleration time of the entrance equipment can be minimized.

As shown in FIG. 8, the actual line speed depends on the operating know-how, but when the plate thickness is large, the line speed is low, and when the plate thickness is thin, the line speed is high.

When looking at the tension settings, in general, when the plate thickness is large, the line speed is low and the tension is high. Further, when the plate thickness is thin, the line speed is high and the tension is low, so a significant effect can be expected by applying the present invention.

A specific example of the effect is shown in FIG. 9(a).

The conventional entrance speed command is based on the entrance speed (VE) as shown by the solid line.
), the acceleration/deceleration rate (α0) is constant, but in the present invention, the acceleration/deceleration rate becomes α11 and α1z as shown by the dotted line in FIG. The amount of loop secured in is small. Then stop and weld work (t.

This will give you more time to deal with any troubles that may occur during the (considerable amount of time).

Since the loop amount that decreases is the integral value of the speed difference between VE and Vc, it is the difference between the shaded portions in the figure, and the loop amount can be small. In the calculation example, when the plate thickness becomes thinner, the acceleration/deceleration time can be reduced to 5 seconds or less compared to 10 seconds in the conventional method, and when stopping,
Waiting for startup will significantly reduce time.

Further, an example of the effect when the stopping distance is minimized will be explained with reference to FIG. 10. For example, when detecting the off-gauge of a strip and automatically stopping it and cutting it with a shear, or when detecting a punch hole in a strip and stopping at a predetermined position, the distance (Lo) from the detector to the stop position is constant. be. Therefore, the distance to decelerate and stop after detection is determined by the line speed (VE) and deceleration rate (α).

As shown in FIG. 10(a), in the conventional method, if the distance from deceleration until the car comes to a stop is Ll, then LL<LO
If so, there is no problem, but if Ll>Lo, the stop position will be over. In this case, either return it manually or
), if the speed is reduced in advance and the stopping distance is set to Lz after detection, Lz<Lo. However, by reducing the speed, the loop amount decreases. However, there are some problems, such as whether the position to decelerate can be correctly recognized in advance.

As shown in FIG. 10(C), according to the present invention, the shortest acceleration/deceleration rate is controlled depending on the material, thickness, width, etc. of the slip, so the stopping distance L3 is smaller than Ll. <If it is Lo, there is no problem.

Even in this case, it is possible that La>Lo, but at least the probability of stopping within the stop position is greater than in the conventional system.

〔Effect of the invention〕

According to the present invention, since the strip is controlled at an acceleration/deceleration rate corresponding to the shortest acceleration/deceleration time, loss time during acceleration/deceleration is eliminated and the amount of loops in the looper arrangement is reduced. On the other hand, the stopping position accuracy is improved and the stopping distance is shortened, thereby improving the product yield.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a flowchart showing an embodiment of the invention, and Figs. 3 to 5 show the relationship between strip thickness and tension, using the thickness as a parameter. 6 to 7 are graphs showing the relationship between strip thickness and tension torque using the strip width and coil diameter as parameters. FIG. 8 is a graph showing the relationship between strip thickness and line speed setting. 9-10 are graphs explaining the present invention in detail. 16... Payoff reel (kl, Nα2), 17...
・Pride roll, 30... Strip, 31...
・Looper.

Claims (1)

[Claims] 1. Acceleration/deceleration for accelerating and decelerating the line speed of the strip of a strip processing line, which is equipped with a reel for feeding the strip into the line, a roll for determining the line speed of the line, and a looper for ensuring the required length of the strip. The control device calculates the acceleration/deceleration time corresponding to the difference between the effective torque and the required torque obtained from the set tension of the strip, the moment of inertia of the reel, and the line speed, and calculates the acceleration/deceleration time corresponding to the acceleration/deceleration time. An acceleration/deceleration control device for a strip processing line, characterized by having an acceleration/deceleration control mechanism that sets the acceleration/deceleration rate of the line.