JPH0342965B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for continuously monitoring eccentricity of a coil unwinding or winding reel of a rolling mill or the like.

<Prior art> In general, when the eccentricity of the reel for unwinding or winding a coil in rolling equipment increases, tension fluctuations occur during rolling, and this can cause crimping defects in, for example, temper rolling mills. or a defective coil winding shape may occur. Therefore, it is important to manage the amount of reel eccentricity.

A conventional method for managing reel eccentricity will be explained with reference to FIG. A dial gauge 1 is installed on the gear box 14 of the coil unwinding or winding device 3.
6 is fixed via a fixing support 15, and the tip of the spindle of the dial gauge 16 is brought into contact with the body surface of the reel 4. The value indicated on the dial gauge when the tip of the spindle is brought into contact with the reel 4 is taken as the reference value. Then, the reel 4 is rotated once and the range of the indicated value of the dial gauge is recorded. As shown in FIG. 6, such measurements are carried out by moving the dial gauge 16 several times in the axial direction of the reel and at several locations as indicated by the arrows. The difference between these measured values and the reference value is determined, and the eccentricity of the reel is mechanically adjusted so that the maximum or minimum value falls within a control value determined empirically in advance.

<Problems to be Solved by the Invention> However, with the above conventional management method, it is not possible to measure the amount of reel eccentricity during actual operation, and it is difficult to measure reel eccentricity with respect to the reel rotation speed during actual operation under load. It is not possible to control the core amount, but only the reel eccentricity when rotating at extremely low speeds with no load.

SUMMARY OF THE INVENTION Therefore, the present invention aims to eliminate the drawbacks of the above-mentioned conventional methods and provide a method and apparatus capable of continuously monitoring the dynamic eccentricity of a reel during actual operation.

<Means for Solving the Problems> A method for continuously monitoring the amount of reel eccentricity in a coil unwinding reel or a take-up reel according to the first invention comprises a coil unwinding reel equipped with a generator or an electric motor. In a method for continuously monitoring the amount of reel eccentricity of a winding reel for a coil, the generator current or motor load current is continuously measured and stored, and the generator current or motor load is measured for each reel rotation time. The current fluctuation range, which is the difference between the highest and lowest current values, is determined, and this current fluctuation range is compared with a predetermined control upper limit value, and an alarm is issued when the upper limit value is exceeded. This is a characteristic feature.

Further, the continuous monitoring device for the amount of reel eccentricity in the rewinding or take-up reel of a coil according to the second invention includes a current detector and a rotation detector of a generator of the unwinding reel or a motor of the take-up reel; A storage/arithmetic device that receives the output signals of the current detector and rotation detector, stores the current value for each rotation time of the reel, and calculates a current fluctuation width that is the difference between the maximum value and the minimum value of the current value. a setting device for automatically inputting a control upper limit value of the difference between the maximum value and the minimum value of the current per rotation time of the reel, and a comparator for comparing the control upper limit value with the current fluctuation width;
It consists of an alarm circuit that receives the signal from this comparator and issues an alarm.

<Function> FIG. 4 shows the time course of the reel eccentricity measured by the method shown in FIG. 2.

That is, as shown in FIG. 2, in a temper rolling mill 1 equipped with bridle rolls 22 at the front and rear, a metal strip is rolled while unwinding a coil 5 held by an unwinding reel 4 of a coil unwinding device 3. 6 is rolled, and the amount of displacement of the barrel surface of the unwinding reel 4 is determined by rolling the gear box 1.
4 is detected by a displacement sensor 17 fixedly supported by a fixed support (not shown), the displacement signal is amplified by an amplifier firer 18, and a recording type 19 is detected.
The horizontal axis represents time, and the vertical axis represents displacement.

The steep portion of the displacement amount of the reel body surface in FIG. 4 is an output generated due to the shape of the reel, that is, the presence of the space 21 between the segments 20 shown in FIG. 3.
Further, the eccentricity of the reel is the difference between the maximum value and the minimum value at the flat portion of the displacement curve within one rotation time of the reel in FIG.

On the other hand, FIG. 5 shows the time course of the reel generator current value measured and recorded at the same timing as the displacement meter output in FIG. 4.

As can be seen from Figures 4 and 5, as the flat part of the displacement curve in Figure 4 becomes higher, the reel generator current value also increases, and the maximum and minimum values of the flat part of the displacement curve increase. There is a correlation between the difference, that is, the amount of eccentricity of the reel, and the difference between the maximum and minimum values of the generator current within one reel rotation time, that is, the fluctuation range of the generator current, and the larger the amount of eccentricity of the reel, the more The fluctuation range of the generator current also increases. This is because the greater the eccentricity of the reel, the greater the tension acting on the metal strip 6 between the bride roll 23 (if there is no bride roll 23, the work rolls 2b, 2b of the rolling mill 1) and the unwinding reel 4. It is thought that the fluctuation becomes large, and therefore the fluctuation of the rotational torque acting on the unwinding reel 4 from the metal band plate 6 becomes large, and the fluctuation of the generator current of the reel 4 increases in accordance with the fluctuation range of this rotational torque.

Although not shown, the relationship between the reel eccentricity of the unwinding reel 4 and the generator current as described above is related to the eccentricity of the take-up reel and the variation in the load current of the take-up reel motor. Regarding the space between
Even if the current is positive or negative, it exists in the same way.

From the above, the generator current of the unwinding reel of a coil equipped with a generator or the motor load current of the winding reel of a coil equipped with an electric motor is continuously measured and stored, and the reel generator current for each rotation of the reel is calculated. Alternatively, by determining the difference between the maximum value of the motor load current, that is, the current fluctuation width, and comparing this current fluctuation width with a predetermined control upper limit value, the eccentricity of the coil unwinding or winding reel can be adjusted during load operation. By being able to continuously monitor the current fluctuation range and issuing an alarm when the current fluctuation range exceeds the upper limit, you can know when the reel eccentricity has become excessive.
By stopping the operation of the equipment and mechanically adjusting the eccentricity of the reel, it is possible to always keep the above current within the control range.

<Example> Next, as an example of the present invention, a specific configuration of a continuous monitoring device for eccentricity of a coil rewinding reel will be explained based on the block diagram of FIG.

In the figure, 1 is, for example, a 4-high rolling mill, and 2
a and 2b are a backup roll and a work roll, respectively. 3 is an unwinding device for the coil 5 for supplying the metal strip 6 to the rolling mill 1, and 4 is an unwinding reel that holds and rotates the coil 5. 7
is a generator connected to the reel 4 for applying tension to the metal strip 6 between the work roll 2b of the rolling mill 1 and the coil 5. 8 is a generator current detector, and 9 is a rotation detector of the generator. 10 is the current detector 8 and rotation detector 9
This is a storage/arithmetic device that receives an output signal from the generator, stores the generator current for each rotation of the reel 4, and calculates the difference between the highest current value and the lowest current value, that is, the current fluctuation width during that time. Reference numeral 11 denotes a setting device for inputting the control upper limit value of the variation width of the generator current in advance, and 12 indicates the control upper limit value set and inputted by the setting device 11 and the generator current variation width outputted from the storage/arithmetic device 10. The comparator outputs an alarm signal to the alarm circuit 13 when the latter exceeds the former.

With the above configuration, it is possible to constantly measure and monitor the variation range of the generator current for each reel rotation time according to the amount of eccentricity of the unwinding reel 4 during operation, and this value is set in advance by the setting device 11. An alarm will be issued if the specified control limit is exceeded.
It is known that the amount of reel eccentricity has become excessive, and it has become possible to bring the amount of eccentricity back within the control range by mechanical adjustment, and the occurrence of crimping defects on the metal strip 6 due to excessive reel eccentricity. It becomes possible to prevent defects in the winding shape.

In addition, in the device configuration shown in FIG. 1, if 3 is replaced with a coil winding device, 4 is a coil winding reel, 7 is a reel drive motor, and 8 is a load current detector for the reel drive motor, the main text can be used as is. The present invention is constructed as an embodiment of a device for continuously monitoring the amount of eccentricity of a coil winding reel, and the same effect as that of the above-mentioned unwinding device can be expected.

Furthermore, specific examples will be described.

In the temper rolling mill, the eccentricity of the unwinding reel was monitored using a device configured as shown in FIG. In the measurement of the example of the present invention, the thickness was 0.2 mm,
When a 20-ton coil with a width of 1000 mm is unwound at a threading speed of 1000 m/min, the eccentricity of the reel is 0.2 to 1.5 mm, and the corresponding fluctuation range of the reel's generator current is 10 to 60 amperes (A). It was hot.

According to past experience, the eccentricity of the reel is 2.5mm.
If the value exceeds 2.0 mm, crimping flaws were observed in the coil, so we set the upper limit for reel eccentricity control at 2.0 mm
The control upper limit value of the variation width of the generator current was entered into the setting device using linear extrapolation as 60-10/1.5-0.2 x (2.0-1.5) + 60 ≒ 19 + 60 = 79 amperes (A).

After adjusting the eccentricity of the reel to 1.0 mm, which was within the control range, and processing approximately 250,000 tons of coils, the fluctuation range of the generator current exceeded 79 amperes (A) and an alarm was issued. The equipment was shut down and mechanical adjustments were made. At this time, the measured reel eccentricity before adjustment was 2.1 mm.

<Effects of the Invention> As described above, according to the method and apparatus for continuously monitoring the amount of reel eccentricity in a coil unwinding or take-up reel of the present invention, the reel can be monitored dynamically, that is, during actual load operation. It becomes possible to continuously monitor the amount of eccentricity at all times, thereby making it possible to prevent quality defects such as poor coil winding shape and crimping flaws.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the apparatus of the present invention, Fig. 2 is an explanatory diagram of the displacement measurement situation of the unwinding reel during skin pass rolling of a metal strip, and Fig. 3 is a longitudinal section of the unwinding reel. 4 and 5 are graphs showing the displacement amount of the rewinding reel drum surface and the time course of the reel generator current, respectively, due to the extension of the refining pressure of the metal strip. FIG. 6 is an explanatory diagram of a conventional method for measuring the amount of reel eccentricity. 1... Rolling mill, 2a... Backup roll,
2b... Work roll, 3... Coil unwinding device, 4... Coil unwinding reel, 5... Coil, 6... Metal strip plate, 7... Generator, 8...
... Current detector, 9 ... Rotation detector, 10 ... Memory/calculation device, 11 ... Setting device, 12 ... Comparator, 13 ... Alarm circuit.

Claims (1)

[Claims] 1. In a method for continuously monitoring the reel eccentricity of a coil unwinding reel equipped with a generator or a coil winding reel equipped with an electric motor, the generator current or the electric motor load current is Continuously measure and store the current fluctuation width, which is the difference between the maximum and minimum values of the generator current or motor load current for each reel rotation time, and set this current fluctuation width to a predetermined control upper limit value. A method for continuously monitoring the amount of reel eccentricity in a reel for unwinding or winding a coil, characterized in that an alarm is issued when the upper limit value is exceeded. 2. Receiving the output signals of the generator of the unwinding reel or the electric motor of the take-up reel and the current detector and rotation detector, and storing the current value for each rotation time of the reel. and a memory calculation device for calculating a current fluctuation width which is the difference between the maximum value and the minimum value of the current value, and one of the reels.
A setting device for automatically inputting a management upper limit value for the difference between the maximum and minimum current values for each rotation time, a comparator for comparing this management upper limit value with the current fluctuation width, and a signal from this comparator. A continuous monitoring device for the amount of reel eccentricity in a coil rewinding reel or a winding reel, comprising an alarm circuit that issues an alarm in response to the alarm.