JPS61119557A - Emergency stop controller in strip taking-up machine - Google Patents

Abstract

PURPOSE:To prevent the destruction of the coil winding form and the breakage of product due to the friction between layers by controlling the regenerative current by calculating the stop time on the basis of the inertia value due to the weight of the coil in winding operation, number of revolution of a motor, and a voltage when emergency brake is applied. CONSTITUTION:A set-value varying signal on a line 11 is introduced into a control current value setting varying circuit 10 by pushing-down an emergency stop button 12, and the regenerative current I of an inverter-side thyristor 5b is brake-applied on the basis of the control current (i) which is supplied from the circuit 11 and varies in real time. In other words, on emergency brake application which is regenerated as the function of the inertia energy, the electric current I which flows in the inverter- side thyristor 5b is controlled in correspondence with the inertia value DG<2>. Said inertia value DG<2> is calculated in a control-current value calculation processor 9, and in the conversion between the inertia value DG<2> and the control current value (i), the inertia value GD<2> which is calculated in the reference to the memory table installed into the apparatus 9 is searched as parameters, and the apparatus 9 renews the old electric current value (i) by sending a new electric current value (i) into the circuit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an emergency stop control device that can prevent damage to a coil during emergency braking of a strip winder for winding metal strip or the like in a rolling system.

[Conventional technology]

In rolling systems for sheet steel, it is common to wind the rolled sheet as a coil using a metal strip winder. In addition, in subsequent various processing lines such as annealing and plating, the strip coil is unwound and subjected to predetermined processing, and then wound up again using a winding machine.

If such a processing line encounters a problem, for example, the strip breaks, it is necessary to put the system under emergency braking to quickly stop the strip winder.

Emergency braking of a strip winding machine is performed by regenerating the inertial energy associated with the motor, the winding shaft or mandrel of the winding machine, and the wound coil during regenerative braking via a separately excited inverter connected in antiparallel. However, if it takes
Conventionally, regenerative braking has been performed with a constant regenerative current.

In other words, the motor stop time T due to this type of regenerative braking
: CD ”-・Motor, mandrel, coil 1tff
Inertia value N based on i ・---m=-・Motor rotation speed (=mandrel rotation speed) ■ −・−−−−− Motor terminal voltage I −−−−
--- Regenerative current K --- As a constant number, it is determined by the following formula, namely: The deceleration time was "CD".

It was determined by N and ■.

[Problem that the invention seeks to solve]

However, when regenerative braking is performed using such a conventional method, if the weight and diameter of the wound coil are large, the coil has a large inertial energy, so if the drill is stopped rapidly, the coil winding may be distorted or the coil may be stripped. The product itself has a greater tendency to rub between the coil and the mandrel or between each layer, causing scratches, which is a problem in terms of quality control of the product.

[Purpose of the invention]

This invention was made in view of the above-mentioned problems, and its purpose is to provide an emergency stop control device that provides a winder with a stop time commensurate with the inertial energy during emergency braking, and that does not adversely affect the product. is to provide.

[Means for solving problems]

In an emergency stop control device that performs regenerative braking by controlling a DC motor mechanically interlocked with a strip winding machine via a separately excited inverter connected in antiparallel, the inertia value of the DC motor and the strip coil being wound is Calculate,
an arithmetic processing unit that searches a regenerative current control value for obtaining an optimal stop time by referring to a built-in conversion storage table from this calculated value; and an arithmetic processing unit that updates and stores the control value from the arithmetic processing unit;
It is characterized by comprising a circuit that sends the stored control value to a circuit that controls the separately excited inverter.

[Effect]

By suitably configuring the invention, during emergency braking of the metal strip winding machine, the current inertia value,
In other words, it is possible to control the stopping time appropriately according to the amount of inertia energy caused by the weight of the coil that has already been wound and its rotational speed, and the optimum stopping time can be controlled according to the weight of the strip coil and the coil diameter at that time. Settings can be made sequentially in real time.

As a result, when the weight and coil diameter of the strip coil are small, the control is performed according to a correspondingly short stop time, and when the weight and coil diameter of the strip coil are large or become large, the control is made faster overall with a correspondingly longer stop time. It is possible to realize a control that can stop the winding and make an early emergency stop without causing the winding to collapse.

〔Example〕

The accompanying drawings show the overall configuration of a cold rolling system to which the emergency stop control method for a metal strip winder according to the present invention is applied, and in the drawings, reference numeral 1 indicates a metal strip to be wound after rolling, 2 is a DC motor (hereinafter simply referred to as a motor), 3 is a mantle-rel of a winder mechanically linked to the output shaft of motor 2, 3a is a coil wound on the mandrel, and 4 is a three-phase power supply , 5 is a converter-side thyristor 5a that acts to supply drive current to the motor 2 during winding, and an inverter-side thyristor 5b that acts to regenerate the electromotive force of the motor 2, which becomes a generator during braking, in inverse parallel. 6 is a current detector that receives a detected current from a current transformer CT that detects the current flowing into the SIRISK control unit 5 during winding; 7 is a connection between the output of the current detector 6 and the line 8; A differential amplifier (op-amp) 9 which receives a current command as an input and obtains an output proportional to the difference between the inputs, will be described in detail later, but is ①.

1, N, D, d, ! , p as input, calculates the inertia value during braking at regular intervals, and determines the control current value i, which is a function of the regenerative current ■, based on the built-in conversion memory table. The processing device 10 always holds the control current value i from the control current value arithmetic processing device 9, and stores the value updated at each fixed cycle, and during normal braking, a predetermined value is set to keep the regenerative current constant. However, at the time of emergency braking due to an emergency stop command, that is, when a set value change signal on line 11 is sent out, the control current value i stored therein is sent out. At the time of winding, the control current value setting change circuit and current limiter circuit 13 sends out to the next-stage current limiter circuit 13, based on the output of the differential amplifier 7, the motor 2, and during normal braking and emergency braking, the control current value i from the control current value setting change circuit 10 is controlled.
This circuit controls the regenerative current r from the motor 2 as a generator via the ignition circuit 15 and the inverter-side thyristor 5b based on S and i.

Now, here, the winding operation of the metal strip 1 under normal conditions will be briefly explained. The strip 1 is wound onto the mandrel 3 as a coil 3a by the rotation of the motor 2, and the power to the motor 2 is supplied to the differential amplifier 7. Converter side thyristor 5a fired by a control circuit including a current limiter circuit 13 and an ignition circuit 14
The power is supplied from the power source 4 via the power source 4.

On the other hand, assuming here that there are cases where braking is applied in a normal state and cases where braking is applied in an emergency such as a breakage of the metal strip 1, the operation is divided into the following two operation modes. One is that the current command on the line 8 is lowered below a predetermined level, the differential amplifier 7 is disabled, and the current of the inverter side thyristor 5b becomes
This is during normal braking, which corresponds to the conventional system, in which regeneration is performed at a constant current based on the control current value is from the control current value setting change circuit 10, and at other times when the emergency stop button 12 is pressed and the braking is performed on the line 11. The set value change signal is introduced into the control current value setting change circuit 10, and the regenerative current 1 of the inverter side thyristor 5b is braked based on the control current value i that changes in real time from the circuit 10. That is, during emergency braking, which is regenerated as a function of inertial energy.

Next, the operation during emergency braking, which is a subject of the present invention, will be described in detail.

In this embodiment, to point out again, the current I flowing through the inverter-side thyristor 5b during emergency braking is controlled in accordance with the inertia value DC in equation (11), and in the actual coil, D・-・If the outer diameter of the coil is d - the inner diameter of the coil! - the coil width p - the specific gravity, then the inertia value GD" of the coil is GD" = - (D' - d' ”) l -p ---
---1.-(2) Since the mass of the mandrel and the motor is constant, GD'' is shown as a constant value M.

Therefore, equation (1) is: Therefore, assuming that T takes an ideal function value, the current value I is expressed as a function f (i) and can be expanded as shown in the following equation.

I=f(i)=P (GD") As mentioned earlier, the inertia value GD" in the above equation is calculated by the control current value calculation processing device 9 according to a desired equation,
The conversion between the inertia value CD'' and the control current value i is performed by referring to the conversion storage table provided in the device 9, and converting the inertia value GD'' to the control current value i.
Search for as a parameter.

By the way, the control current value i here is the diameter D of the coil sampled at a predetermined period by the control current arithmetic processing device 9.
, the plate width l, the specific gravity p, the motor voltage ■, and the rotation speed N, which are periodically obtained from the inertia value GD2, and the control current value calculation processing device 9 uses this new current value for control. The current value i is sent to the control current value setting change device 10 to update the previously held control current value i.

In this case, by shortening the sampling period,
Continuous control is possible.

Here, the value of the control current value i with respect to the inertia value GD2 is a value obtained from experience or experimentation and is set in advance, but it can also be approximated by a predetermined function. In this case,
The control current value i is determined from the inertia value CD'' by functional calculation.

Further, the control current value setting change circuit 10 is one numerical memory of the digital thyristor device, and serves as an interface connecting the current 9477 circuit 13 and the control current value calculation processing device 9, and at the same time serves as an interface for connecting the current 9477 circuit 13 and the control current value calculation processing device 9. The current limiter circuit 13 has a function of taking in a set value change signal on the line 11 and correcting the set value of the current limiter circuit 13 in real time.

〔Effect of the invention〕

In this invention, the regenerative current is controlled based on the inertia value due to the weight of the wound coil etc. during emergency braking, the rotation speed and voltage of the motor, so the coil is controlled based on the weight of the coil at that time and the coil It is possible to stop at an appropriate stop time calculated in real time corresponding to the diameter. Therefore, it is possible to make an emergency stop at an early stage, and prevent the winding from collapsing.
Rubbing between the strips can be avoided, ensuring good quality.

[Brief explanation of drawings]

The accompanying drawing is an overall configuration diagram of a cold rolling system to which the emergency stop control device for a metal strip winder according to the present invention is applied. 1--Strip, 2--Motor, 3a-
- Coil, 5 - Cyrisk control unit, 9 - Control current value calculation processing device, 10 - Control current value setting change device, 13 - Current limiter circuit.

Claims (1)

[Claims] In an emergency stop control device that performs regenerative braking by controlling a DC motor mechanically interlocked with a strip winding machine via a separately excited inverter connected in antiparallel, the inertia value of the DC motor and the strip coil being wound is Calculate,
an arithmetic processing unit that searches a regenerative current control value for obtaining an optimal stop time by referring to a built-in conversion storage table from this calculated value; and an arithmetic processing unit that updates and stores the control value from the arithmetic processing unit;
An emergency stop control device comprising: a circuit that sends the stored control value to a circuit that controls the separately excited inverter.