JPS63123528A - Tension controller - 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] [Field of Industrial Application] The present invention relates to a tension control device for a steel strip in a processing line such as a rolling mill, and particularly to a tension control device for a steel strip between a bridle roll and a winding or unwinding reel. This invention relates to a tension control device suitable for absorbing.

[Conventional technology]

A starting end or a terminal end of the rolling apparatus is equipped with a reel that continuously winds up or unwinds the steel strip via a bridle roll that controls the speed of the steel strip. Tension fluctuations occur in the steel strip between the bridle roll and the reel due to various external factors. Since this tension fluctuation has a large effect on the quality of the steel strip product, it is necessary to absorb it by some means.

As a means for absorbing this tension fluctuation, a control device is known that applies forcing when the fluctuation factor is acceleration or deceleration of the speed of the steel strip, for example (see, for example, Japanese Patent Laid-Open No. 49-31565).

[Problem that the invention seeks to solve]

In conventional control devices, the reel current (torque) command is an open-loop control command, and it is difficult to compensate if a calculation error occurs or a disturbance occurs when the carousel reel revolves. , a tension fluctuation that cannot be ignored will occur. This tension fluctuation causes meandering of the steel strip and poor tightening of the reel, which leads to a deterioration in quality. Examples of this calculation error include a slip in the detection roller when detecting the reel rotation speed, which causes errors in the coil diameter calculation (used for GD calculation), and errors in the initial data used for calculation. This calculation error results in incorrect current commands during acceleration and deceleration, which causes tension fluctuations.

Therefore, an object of the present invention is to provide a tension control device that can reliably and accurately absorb tension fluctuations in a steel strip.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a tension control mechanism that controls the tension of the steel strip between a bridle roll that is driven by an electric motor and controls the speed of the steel strip, and a reel that unwinds or winds up the steel strip. The control device is characterized in that it includes a current detector that detects the load current of the electric motor, and a reel control device that applies torque to the reel that is proportional to the amount of change in the detected current.

This system focuses on the fact that fluctuations in the tension of the steel strip directly appear as changes in the load current of the bridle roll drive motor, and detects changes in this load current and feeds the corresponding torque back to the reel. It is.

[Effect]

According to the above configuration of the present invention, when tension fluctuation occurs in the steel strip, the load current of the drive motor of the bridle roll changes immediately due to this fluctuation. This current change is detected by a current detector, and the reel output torque is feedback-controlled by the reel control device based on the detected current.
As a result, tension fluctuations are absorbed.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings.

T! A first embodiment of the present invention is shown in FIG. 1 of the JJL paper. As shown in FIG. 1, a bridle roll 2 is placed at the end of a processing line such as a rolling mill.

The steel strip 1 is wound onto a reel 3 via this bridle roll 2 while its running speed is controlled.

The bridle roll 2 is driven by an electric motor 4. The electric motor 4 is a speed control device based on the speed master command 6 given from the outside! ! 5, the speed is controlled to a constant speed. A current detector 11 is inserted into the main circuit of the motor 4 to detect the current flowing therein, that is, the load current.

The reel 3 is driven by an electric motor 17. The electric motor 4 is
Torque control is performed by the current control device 8 based on the sum of the current master command (or torque command) 9 given from the outside and the feedback signal from the reel control bag fit (details will be described later) according to the present invention. , controlled by a current proportional to the tension acting on the steel strip 1 between the bridle roll 2 and the reel 3.

Next, a reel control device according to the present invention will be explained.

First, the load current of the electric motor 4 of the bridle roll 2 is detected by the current detector 11. This detected value passes through gate A12 at a specified timing.

It is stored in the memory 13 as a reference value. The difference between this memory value and the actual detected value is calculated by the gain circuit 14. It is given as an additional command to the current control circuit 8 of the reel 3 which passes through the gate B15. The above difference becomes the change in load current of the bridle roll. The memory control circuit 16 controls the gate A12 and supplies the memory 13 with a current that serves as a reference for the bridle roll 2.
It also controls the gate B 15 to output a deviation signal to the reel 3. The compensation circuit 17 compensates the stored reference value so that changes in the current necessary to drive the bridle roll 2 during acceleration or deceleration of the bridle roll 2 are not mistaken for fluctuations due to external factors.

Next, the movement of signals in this circuit will be explained with reference to FIG.

FIG. 2 is a time chart showing the movement of the signal when the speed of the bridle roll 2 is changed. When the Priddle load current machine is operating at a constant speed N, a constant current flows, and when acceleration/deceleration is performed, a current corresponding to the following equation (1) flows.

375 dt The output of the compensation circuit 17 is calculated by formula (1) above, and is output during acceleration/deceleration.The output is G
Since D'' is constant, it will be a constant value if the acceleration/deceleration rate is constant.

Gate A turns on momentarily Tz seconds after the speed becomes constant.
L. The current value at that time is stored in the memory 13. Gate B is ONL after gate AON, then there is a speed change, and it becomes constant speed again and remains ONL until T1 seconds later. Timings T1 and Tz detect the accurate load current of the bridle roll. Take the time necessary for this. That is, this is the timing for closing the gate B and storing in the memory 13 the load current of the bridle roll in a state where no external deviation signal is input to the reel 3.

Now, 1. For example, if we consider a case where the coil diameter value is incorrect and the forcing amount is small, the deviation output value to reel 3 will be as shown in Figure 2, and the reel will output the necessary regular current command. As a result, the shortage of forcing is covered and tension fluctuations are absorbed.

Next, a case where the present invention is applied to a carousel reel will be explained with reference to FIG. In FIG. 3, parts that overlap with those in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted.

In the carousel roll, the revolving drum 10 holding the two reels 3 and 3' is rotated 1801 times in the direction of the arrow in the figure, the positions of the two reels are switched, and one reel continues to wind and the coil diameter is maximized. When this happens, winding begins on the other reel, making continuous winding possible. As a feature of the Carousel reel, there are 10 revolving drums.
When the steel strip 1 is rotated, the length of the steel strip 1 between the bridle roll 2 and the reel 3 changes (that is, the number of rotations of the reel changes), and the output torque in terms of the steel strip tension of the reel 3 changes. Figure 4 shows the phenomenon in which the tension of the steel strip changes due to this torque fluctuation, and the load current of the priddle is affected. As the position of the reel 3 changes from 00 to 180 m, the length of the steel strip initially becomes shorter. , then becomes longer. The reel output torque first increases and then decreases. Accordingly, the load current of the priddle initially decreases and then increases.A of the reel output torque curve in Figure 1 is the current state, but if a torque equivalent to B is applied to the reel itself, it will eventually fluctuate as shown in C. It can be made into the form of absorption. Here, the curve C becomes the same as the change in the priddle load current.

Note that although curves A, B, and C shown in Figure 4 show static movements, they are actually feedback control, so if a deviation occurs, it operates in the direction of suppressing the deviation, and the apparent torque fluctuation of A is It appears that there is no such thing.

The above method makes it possible to absorb tension fluctuations in the steel strip without making major changes to existing equipment.

Although the take-up reel has been described above, the same applies to the rewind reel.

〔Effect of the invention〕

According to the present invention, the tension fluctuations occurring in the steel strip can be absorbed by changing the torque command of the reel by capturing the tension fluctuations occurring in the steel strip by the load fluctuations of the bridle roll. It is possible to maintain good quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention. Fig. 2 is a timing chart showing the signal timing and signal movement of the present invention, Fig. 3 is a block diagram showing the second embodiment of the invention, and Fig. 4 is reel torque variation and bridle roll load current. It is an explanatory diagram showing the relationship. DESCRIPTION OF SYMBOLS 1... Copper body, 2... Bridle roll, 3... Reel, 4.7... Drive machine, 5... Speed control device, 6
...Speed master, 8...Current control device, 9...
Current master. 10...Revolving drum, 11...Current detector, 12°15...Gate, 13...Memory, 14...Gain. 16...Memory control circuit, 17...Compensation circuit.

Claims (1)

[Claims] 1. A tension control device that controls the tension of the steel strip between a bridle roll that is driven by an electric motor and controls the speed of the steel strip and a reel that unwinds or winds the steel strip. A tension control device comprising: a current detector that detects a load current of the electric motor; and a reel control device that applies a torque to the reel that is proportional to the amount of change in the detected current.