JPS6140731B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a process line with a looper.

In a process line, for example, a continuous annealing line for steel strips, a center section, that is, a loop car at the entrance and exit of the furnace, is installed at the entrance and exit of the furnace so that the threading speed in the annealing furnace can be maintained at a constant rate. A looper such as a loop tower or a loop tower will be installed.

Among these, in the vertical looper, steel strips are alternately stretched between a group of rollers fixed and pivoted on the upper part of the structure and a group of rollers pivoted on a carriage that can move up and down with respect to the roller group. In combination with a bridle roller that controls the speed of the steel plate, the storage amount of the steel strip in the looper, that is, the loop capacity, is adjusted by moving the carriage up and down.

During steady operation, both the inlet and outlet sections are operated at the same threading speed as the center section, and at this time, the carriages of the inlet and outlet loopers stand still at a constant level, and this stationary position is Often called sync position. The synchronization position of the carriage corresponds to the maximum storage amount on the input side and, conversely, the minimum storage amount on the output side, and is located at a low level and a high level, respectively.

However, in the past, this synchronization position was set at a specific position, so if, for example, the maximum storage capacity included a part of the steel strip with a poor shape, it would cause meandering, which could sometimes cause the strip to come off the roll and break. , since the length of one pass is often 15 to 20 m, if not that long, the contact between adjacent steel strips causes scratches, which causes a decrease in yield. During continuous annealing, the temperature is 100 to 120℃, and the suitable coiling temperature for this steel strip is 40℃ for the next step of temper rolling.
If the storage amount of the looper is too small even though the temperature is 50 to 70℃ to maintain the appropriate temperature, the cooling effect of the atmosphere may not be fully utilized.Differences in temperature also affect the temperature, so I am dissatisfied with the matching.

Of course, it is possible to operate the steel strip out of the synchronized position, but in that case, it is necessary to constantly monitor and adjust the speed of the steel strip in the sections before and after the looper, which is extremely troublesome in terms of operation.

This invention is a result of development to particularly advantageously solve the problems in the prior art.In particular, the synchronization position of the looper carriage can be arbitrarily set to be variable, and the actual position relative to the set value can be changed. By detecting the deviation and controlling the acceleration/deceleration of the bridle roller, stable operation in the above-mentioned type of process line is realized.

FIG. 1 shows an example of an embodiment in which the present invention is applied to an entrance looper of a continuous annealing furnace.

In the figure, a is a continuous annealing furnace, l is a looper on the entry side, b is a bridle roller, and the looper l consists of a fixed pivot roller group r _u and a movable pivot roller group r _e on a carriage c. .

Here, the vertical position of the carriage c is monitored by the detector 1, the pulse oscillator 2 oscillates a pulse corresponding to the position of the carriage c, and the detection signal A is sent through the counter 3, and the synchronized position setting device 4 is made arbitrarily variable. The speed of the bridle is changed based on the deviation signal A-B after comparing it with the set value B in the comparator circuit 5. When A-B=0, the output of the function generator 7 is 1, that is, the bridle rotates according to the command from the main speed generator (MRH) 8. When A-B>0, the output of the function generator 7 becomes 1 or more, and that value is multiplied by the output of the main speed generator (MRH) 8 in a multiplier 9, causing the bridle to rotate faster. The opposite is true when A-B<0. In the illustrated example, the output of function generator 7 is 1.2 or
The reason why it is saturated at 0.8 is to prevent the speed from changing too rapidly.

On the other hand, the detected voltage D proportional to the actual speed of the bridle roller b by the tacho generator 10,
By comparing the voltage command C with the comparison circuit 11 and sending the deviation signal C-D to the speed regulator ASR12, the output of the thyristor 14 is adjusted by the gate pulse generator 13 via the current regulator ACR12'. , accelerates and decelerates the rotational speed of the bridle motor 15, and thus controls the synchronous position of the carriage c.

As described above, according to the present invention, it is possible to arbitrarily and variably adjust the required storage amount in the looper to easily and appropriately avoid process disadvantages resulting from excessive or insufficient storage, and to achieve stable Operation can be realized.

[Brief explanation of the drawing]

The figure is an explanatory diagram illustrating the application of an embodiment of the present invention to a continuous annealing furnace entry side looper.

Claims (1)

[Claims] 1. For a process line that includes a looper in which steel strips are alternately stretched between a group of fixedly pivoted rollers and a group of rollers that are pivoted on a carriage that can be raised and lowered relative to the roller group, A method of operating a process line with a looper, which consists of detecting the synchronized sheet threading position, comparing it with an arbitrarily variable setting value, determining the deviation from it, and controlling the acceleration/deceleration of the bridle rollers before and after the looper based on this deviation.