KR20000043874A - Device and method for preventing cold roller from chattering - Google Patents

Abstract

PURPOSE: A device and a method are provided to detect a chattering situation and find the cause by converting the control signal and the vibration signals of a roller to synchronized signal frequency. CONSTITUTION: Coil information(32), a control signal(31) and the vibration signal of a roller are input to a data collecting system(27). The system senses and stores an actual measurement of eight channels in the control signal and the effective measurement and the converted measurement of six channels in the vibration signal. Then, the system monitors if velocity of a signal process is regular. When relative change degree is larger than the set velocity, an alarm is generated, and the system calculates and stores all channels of the control signal and the vibration signal. When the signal is two times larger than an average value and high frequency signal is generated while alarming, the system reduces velocity of the signal process by switching an automatic velocity decrease mode on.

Description

Cold rolling machine chatter prevention device and method

The present invention relates to a cold rolling mill chattering prevention device and method, in particular, in the cluster type 20-stage cold rolling mill, which is a rolling mill of high grade steel such as stainless steel, whether or not chattering occurs when chattering occurs due to vibration of the rolling mill. And a method for diagnosing the cause and cause of chattering by converting the digital signal processing to the simultaneous signal frequency conversion of vibration signals, input / output tension, input / output thickness, input / output thickness, rolling force, and motor current. It is about.

The chattering of the conventional rolling mill is caused by the vibration of the work roll being transmitted to the support bearing of the work roll, the work roll fixing mechanism, the stand frame, etc., and when the progress measurement value exceeds a certain level, the characteristic of the rolling mill is analyzed by analyzing the frequency characteristic of the signal. It is known that it prevents chattering when the component appears, but chattering in cluster type 20 stage cold rolling mill which rolls high hardness products at high speed is not only vibration in rolling mill but also Chattering occurs due to complex factors such as fluctuations in outgoing tension and fluctuations in pressing force, and when chattering occurs, the chattering signal can be seen through the vibration signal as well as the operation signal. In addition, when performing frequency analysis of the signal, as shown in the conventional system of FIG. 2, only a channel having a large vibration level is analyzed for frequency, and when performing a frequency analysis on signals of other channels, it is about 5 In addition to the delay of a second, when there are many monitoring channels, it takes time in proportion to the number of channels, which makes it impossible to verify by comparing the signals between channels. In addition, data management is performed irrespective of rolling speed or coil information, so that not only the verification after chattering occurs, but also the reason for the information of the coils that were not detected due to the weak chattering signal in the coil with the non-measurable chatter mark. There is a problem that cannot be known.

The present invention is to solve the above problems, by using two built-in digital signal processor of eight channels at the same time without using a frequency conversion analyzer and a channel selector for frequency conversion of the external one-channel signal of 16 channels at the same time To improve the chattering prediction rate by analyzing the vibration signal and the operation signal at the same time, extract the frequency component according to the speed through the rolling speed signal, and manage the data based on the coil information. The purpose is to verify the reliability of the chattering and to provide information such as the cause of the plate breaking caused by the operation signal.

The above-mentioned object consists of a work roll, a first support roll supporting a work roll, a second support roll supporting a first support roll, and a backup roll supporting a second support roll to roll a coil passing between the work rolls. In the cold rolling mill, a plurality of vibration sensors installed in the cold rolling mill, a vibration signal amplifier for amplifying a signal input from the vibration sensor, a vibration sensor signal extraction unit for extracting a signal from the vibration sensor, the cold A rolling mill control signal extracting unit for extracting measured values of signals acting when controlling the rolling mill, a coil information extracting unit for receiving information on the coil, the coil information sunrise unit, the rolling mill control signal extracting unit, A data collection system receiving respective data from the vibration sensor signal extracting unit, and data input from the data collection system It is achieved by a cold rolling machine chattering prevention device comprising a data analysis system for predicting chattering, storing data and analyzing the cause through.

In addition, the above object is to prevent the chattering occurring on the surface of the coil passing through the cold rolling mill in the method of preventing chattering, the coil information is input to the data collection system, the rolling mill control signal and vibration signal to the data collection system The input step, monitoring and storing the measured values of 8 channels of control signals, calculating and detecting and storing the signal effective and strain values of the 6 vibration signals, comparing the speed is constant, and the relative rate of change It generates an alarm for the signal when it is loud, and simultaneously calculates and stores 8 channels of the control signal and 8 channels of the vibration signal; Requesting speed reduction when a high frequency signal set to the cheter frequency is generated and an automatic speed reduction mode is activated. Cold rolling mill chatter, comprising a step of including in the ring is achieved by prevention.

1 is a view showing the structure of a chattering prevention device in a cluster type 20 stage cold rolling mill.

2 is a diagram illustrating an existing system and a proposed system in a signal collection method.

Figure 3 is a view showing the overall structure of the chattering prevention device in a cluster type 20 stage cold rolling mill.

4 is a flowchart of a chattering prevention method according to the present invention;

<Description of the symbols for the main parts of the drawings>

1: working roll 2: first supporting roll

3: second support roll 5: backup roll

6: vibration acceleration sensor 7: work roll support

8: cold rolled coil 9: lower cluster

10: upper cluster 11: rolling mill housing

12: Entry upper spindle 13: Exit upper spindle

14: entry lower spindle 15: exit lower spindle

16: gearbox 17: coupling

18: motor 19: vibration signal amplifier

20: cable for receiving vibration signal 21: cable for receiving control signal

22: digital signal processing means for control signals

23: digital signal processing means for the vibration signal

24: means for Ethernet communication

25: Ethernet communication board for receiving coil information

26: Ethernet cable 27: Data acquisition system

28: Ethernet Cable 29: Data Analysis System

1 is a view showing the structure of a chattering prevention device in a cluster type 20 stage cold rolling mill, FIG. 2 is a diagram showing an existing system and a proposed system in a signal collection method, and FIG. 3 is a chatter in a cluster type 20 stage cold rolling mill. It is a figure which shows the whole structure of a ring prevention apparatus, and FIG. 4 is a flowchart of the chattering prevention method by this invention.

As shown in FIG. 1, the apparatus of the present invention includes a vibration sensor signal extractor 30 provided in each part of the rolling mill, a mill control signal extractor 31 for extracting measured values of signals acting when controlling the mill, and one coil. Coil information extraction unit 32 for drawing the coil number, steel grade, etc., vibration signal, rolling mill control signal, data collection system 27 for receiving coil information, foresee chattering through collected data, and stores data It consists of a data analysis system 29 for analyzing the cause.

In the detailed view of FIG. 3, the cluster type 20 stage cold rolling mill is composed of 10 rolls of upper and lower sides. Each roll has one work roll (1) for rolling the coil, two first support rolls (2) for supporting the work roll, three second support rolls (4) for supporting the first support roll, and second It consists of four backup rolls (5) supporting the support roll, the second support roll is connected to the drive motor to drive, the other rolls, etc. are non-driven roll. The vibration sensor 6 uses the safety type acceleration sensor to support the work roll support 7 of the rolling mill, the first support roll support, the upper cluster 10, the lower cluster 9, the one lower spindle 14 and the exit lower spindle. (15) was installed in the vertical direction, and because the signal from the rolling mill is weak, the signal was amplified by 10 times using the vibration signal amplifier 19. As shown in the proposed system of FIG. 2, the amplified signal is inputted to digital signal processing means (board: 23) for vibration signal at the same time to perform signal processing.

On the other hand, the data acquisition system 27 is composed of a digital signal processing means 22 for control signals, a digital signal processing means 23 for vibration signals, an Ethernet communication means 24, and an Ethernet communication means 25 for receiving coil information. The rolling mill control signal is input to the digital signal processing means for the control signal through the cable 21. The vibration signal is also input to the digital signal processing means 23 for the vibration signal. In addition, the coil information is input to the Ethernet communication means 25 for receiving coil information through the cable 26. The rolling mill control signals are rolling speed signal, landing tension signal, landing tension signal, rolling force signal, landing thickness signal, exit thickness signal, rolling mill motor current signal, roll gap signal. Coil information is coil number, steel grade, surface finish, material thickness, material width, preprocess, and total pass.

The digital signal processing means (board: 23) for the vibration signal acquires 5,120 data per second for each channel of the input vibration signal, and displays the effective values, peak-to-peak, crest factor, and power spectrum as shown in Equations (1) to (4). Calculate

RMS = SQRT [(∑ _{t = 1, T} X (t) * X (t)) / T] ..... (1)

Peak to Peak = Sampling Maximum-Sampling Minimum ....... (2)

Crest Factor = Peak to Peak / (2 * Effective Value) ........ (3)

Power spectrum = ∑ _{n = 0, N-1} [x (n) * e ^ {-j2πkn / N}] ...... (4)

The following is about the control signal of the rolling mill. The measured value of the signal controlled by the rolling mill is directly extracted from the electrical chamber, and an isolator is installed on one side to prevent problems such as voltage drop when the analog signals are drawn in parallel. Signals such as rolling speed, entry / exit tension, entry / exit thickness, rolling force, rolling mill motor current, and roll gage are simultaneously input to the control signal digital signal processing means (board: 22) to perform signal processing. The control signal inputted to the digital signal processing means (board) 22 for the control signal is converted into corresponding engineering units for each channel, and 5,120 data sets are acquired to calculate a power spectrum as shown in Equation (4). .

In addition, coil information such as coil number, steel grade, surface finish, material thickness, material width, front process, total path, etc. is received by Ethernet communication means 25 for receiving coil information once and manages data.

The collected data is sent to the data analysis system 29 by Ethernet communication in real time.

In the data analysis system 29, the received data is monitored in real time through a schedule configured for the operating environment, and a harmonic component of the component set as the chatter frequency or a value exceeding an alarm level set value weighted according to the rolling speed is vibrated. When a signal or control signal is received, a message to reduce the speed is displayed on the screen. Through this message, the operator executes the automatic speed reduction mode to cope with chattering and sudden abnormality. In addition, it works at different speeds during several passes in one coil, so when the working speed is kept constant for 10 seconds, the power spectrum is stored and used for investigation of the cause of the abnormality. When all the information is stored and it is a problem within 10 days after work, it is configured to know which of the vibration and the control signal through the stored data.

According to the present invention, in the cluster type 20 stage cold rolling mill, which is a rolling mill of high grade steel such as stainless steel, it prevents chattering caused by rolling mill vibration and chattering caused by sudden change of control signal, When there is a problem, it is not only caused by some cause but also by the stored signal to ensure the reliability of the rolled product and increase the line speed to contribute to productivity improvement.

Claims (3)

In a cold rolling mill for rolling a coil passing between the work rolls, consisting of a work roll, a first support roll supporting a work roll, a second support roll supporting a first support roll, and a backup roll supporting a second support roll , A plurality of vibration sensors installed in the cold rolling mill, A vibration signal amplifier for amplifying a signal input from the vibration sensor; A vibration sensor signal extracting unit for extracting a signal from the vibration sensor; A rolling mill control signal drawing unit for drawing out measured values of signals acting when controlling the cold rolling mill; A coil information extracting unit receiving information about the coil; A data acquisition system receiving respective data from the coil information sunrise unit, the rolling mill control signal extractor, and the vibration sensor signal extractor; And a data analysis system for predicting chattering through data input from the data collection system, storing data, and analyzing the cause. The method of claim 1, The data collection system Digital signal processing means for a control signal for processing a signal input from the rolling mill control signal extracting unit; Digital signal processing means for the vibration signal for processing the signal input from the vibration sensor signal extraction unit; Ethernet communication means for receiving coil information for processing information input from the coil information extracting unit; Cold rolling mill chattering prevention device comprising an Ethernet communication means for communication between the data collection system and the data analysis system. In the chattering prevention method, to prevent chattering occurring on the surface of the coil passing through the cold rolling mill, The coil information is input to the data collection system; A mill control signal and a vibration signal are input to the data collection system; Monitoring and storing the measured values of the control signal 8 channels, calculating and detecting the signal effective values and the strain values of the 6 vibration signal channels, and comparing the speeds with each other; Generating an alarm for the signal when the relative change rate according to the speed is large, and simultaneously calculating and storing 8 control signals and 8 vibration signals; Requesting a speed reduction when the signal at the time of alarm occurrence is greater than twice the average value and when a high frequency signal set to the chetter frequency among control and vibration signals is generated; Cold rolling mill chattering prevention method comprising the step of operating the automatic speed reduction mode.