JPH11326147A - Roller table equipment diagnosis method and equipment diagnosis device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To accurately diagnose an operating condition of a drive motor or a mechanical drive system of a roller table without incurring facility costs so that an abnormality can be reliably detected. SOLUTION: A current signal of a motor driving a roll is captured one by one, and a starting state detecting unit for detecting a starting current and a starting time immediately after operation, a detection of a current value in a stable period, and a calculation of a vibration cycle and an amplitude of the current. It has a current change detection mechanism composed of a roll eccentricity detection unit, and by sequentially switching each detection unit according to the operation signal of the motor, the operation state of the current change of the motor from operation start to stop A roller table equipment diagnosis apparatus characterized in that the roller table is continuously diagnosed according to the conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive motor for a roller table group for transporting a steel material or the like in the iron and steel industry by driving a cylindrical roll by an electric motor, a method for diagnosing equipment of a mechanical drive system, and an equipment diagnosis apparatus.

[0002]

2. Description of the Related Art As a conventional method for diagnosing equipment abnormality of an industrial machine, various types of detectors are installed at a plurality of locations to be diagnosed, and signals obtained from the detectors are processed to detect and diagnose the abnormality. There was a way to do that. For example, bearing failure (damage of bearing, seizure, eccentricity of load rotating body, etc.)
There has been a method in which a vibration detector is installed on a bearing part to diagnose the abnormality, and the abnormality is diagnosed based on the behavior of the vibration frequency and the amplitude. Also, a method of taking out the current of the drive motor in place of a large number of equipment diagnostic detectors, determining the maximum value, minimum value, average value, and the like of the current value and comparing it with a preset value to determine an abnormality. Alternatively, there is a method of detecting a change rate of a current and comparing it with a preset value to determine an abnormality.

[0003] In such a method, Japanese Unexamined Patent Application Publication No. 52-143856, which detects an abnormality by correcting the current value under no load by the number of revolutions of the motor, and frequency analysis or position analysis of the AC current waveform of the motor. JP-A-61-15147, JP-A-61-1514
78, JP-A-61-151479, and JP-A-61-186870 and JP-A-61-186871, in which the unbalance rate of the phase and amplitude of a current waveform is determined and an abnormality is diagnosed. A method of detecting an abnormality by detecting the current of the motor driving the motor and comparing the obtained current value with a fixed upper limit and a lower limit set value, and an abnormal value comparison diagnosis, and the latest moving average value and deviation value of the current signal Japanese Patent Publication No. 6-95059 discloses a method of determining an abnormality by a relative value comparison diagnosis based on the results of aging based on the results. Japanese Patent Application Laid-Open No. 7-194186 discloses that current signals of at least two electric motors having the same driving conditions are extracted, and a difference between the detected currents is compared with a reference value and a reference time to determine an abnormality. Have been.

[0004]

However, according to the conventional method, in the conventional equipment diagnosis in which various detectors are installed, the detectors are directly installed at the locations to be diagnosed. Since the detector is installed on site,
An enormous amount of labor was required for maintenance of the detector, and it was difficult to maintain the detection accuracy constant.

Japanese Patent Application Laid-Open No. 52-143856 discloses a method of diagnosing the load current of a motor for driving a machine, which requires an expensive rotation detector for diagnosing equipment abnormality. Is also necessary. Also, JP-A-61-151477 and JP-A-61-1
51478, JP-A-61-151479, JP-A-61-151479
186870, JP-A-61-186871,
This is an effective means for diagnosis when the motor alone is operated alone, but when the motor is connected to a load such as a reduction gear or a bearing, the AC waveform of the load current is diagnosed using a high-speed sampling mechanism. However, there is a problem that even a current change and a phase change in an unusual state are detected as abnormal, and the device becomes very expensive because of having a high-speed sampling mechanism.

Further, Japanese Patent Publication No. 6-95059 discloses that
In the absolute value comparison diagnosis that compares the current value of the motor that drives the mechanical system with the upper limit value of about 80% and the lower limit value of about 20% of the rated current of the motor, the range of the current change that is determined to be normal is the rated range. Since the current is as wide as 20% to 80%, a slight increase in current due to lack of lubricating oil in reduction gears and bearings is buried in the load current and cannot be detected. In addition, if the upper and lower limits are narrowed, There is a problem that a current change under a normal load state is erroneously detected as an abnormality. Also, in the relative value comparison diagnosis, a certain number of data (the number of data L = 0 in the above-described conventional invention) is used for moving average of the latest current value.
３０T, sampling time ΔT = 6 seconds or less), which means that the time for detecting an abnormality is delayed by L × ΔT ÷ 2, and in order to prevent detection delay, the number of data L or the sampling time It is necessary to reduce ΔT, but if this value is reduced, the moving average value and the deviation value approach the obtained current value infinitely, so that there is a problem that an abnormality cannot be detected, and furthermore, an abnormal phenomenon of equipment When the current gradually increases or decreases over a long period of time (for example, load increase due to reduction of lubricating oil or grease of reduction gears and bearings), comparison based on the results of aging based on deviation values is performed. However, there is a problem that it cannot be detected, so that the above-mentioned conventional invention cannot exhibit the effect, and cannot be said to be a highly useful diagnostic method.

Further, according to the method disclosed in Japanese Patent Application Laid-Open No. 7-194186, diagnosis cannot be made unless the same specifications and operating conditions are used, and an abnormality is determined based on a current difference between at least two drive motors. There is a problem that it is not possible to determine which one is abnormal even when a current difference occurs.

Further, in any of the above-mentioned methods, a great deal of labor is required to determine a reference value for judging an abnormality. For example, in the method of diagnosing by the load current of the motor driving the roller, having various roller lengths and roller diameters, the behavior due to the abnormality of the roller table composed of various devices is simply the maximum value of the load current value, It is difficult to diagnose with the minimum and average values, and it is important to determine the reference value for abnormality determination that matches the equipment situation in order to increase the diagnostic accuracy. Based on the specifications and test report of the motor, set it relatively high or low and run for several days to check the situation, gradually change the reference value to lower or higher, change the situation further, etc. There is a problem that it takes a lot of time and effort to repeat trial and error.

[0009]

The gist of the present invention is as follows. (1) In a roller table group that conveys steel and the like by driving a cylindrical roll by an electric motor, a starting state detecting unit that captures a current signal of the electric motor that drives the roll one by one and detects a starting current and a starting time immediately after the operation. And a current change detection mechanism configured by a roll eccentricity detection unit that detects a current value in a stable period and calculates a vibration cycle and amplitude of the current, and sequentially switches each detection unit according to an operation signal of the electric motor. A roller table equipment diagnosis apparatus characterized in that the behavior of a change in current of a motor is continuously diagnosed in accordance with the operation state from the start to the stop of the operation of the motor. (2) In a roller table group for conveying steel materials by driving a cylindrical roll by an electric motor, a current signal of the electric motor for driving the roll was captured one by one, and obtained by a starting state detecting unit and a roll eccentricity detecting unit. Roller table equipment diagnosis characterized by having an abnormality determination generation unit that accumulates past detection results, obtains a standard deviation from past measurement values, and automatically determines a reference value for determining abnormality of the roller table equipment. apparatus. (3) A current signal of the motor immediately after driving the roller table by the starting state detection unit of (1) is captured by an operation signal, and the current signal reaches a maximum value at that time and reaches a rated current determined by the specification of the driving motor. By measuring the startup time, which is the time, and comparing these measured values with the abnormality determination reference value determined by the abnormality determination generation unit, it is possible to diagnose the equipment failure of the coupling, reduction gear and roll bearing from the motor alone. A feature of the roller table equipment diagnosis method. (4) When the motor driving the rolls by the roll eccentricity detection unit has started up, the current signal of the motor is set to a maximum current value in a predetermined period during a stable period in which no load is placed on the roller table and no load is present. Measure the minimum current value and average current value,
By comparing these measured values with the abnormality determination reference value determined by the abnormality determination generation unit, it is possible to diagnose the equipment abnormality of the coupling of the electric motor, the reduction gear and the bearing of the belt drive pulley, and the equipment diagnosis of the belt conveyor. Method. (5) The pulsating current of the load current of the driving motor when the roll is eccentric in the roll eccentricity detection unit is used to remove the noise by the filter unit, and the current change after the noise is removed is reduced to zero by the peak-to-peak detection unit. By detecting the current difference and time between the following two points and calculating the pulsation period and amplitude of the current in the calculation unit, and comparing the calculated value with the abnormality determination reference value determined by the roller table specifications (roll rotation speed, roll diameter, etc.). A method for diagnosing the equipment of a roller table, comprising diagnosing presence / absence and size of roll eccentricity.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention relates to a roller 1 for conveying a steel material, a bearing 2 for supporting the roller 1 and a speed reducer 3 as shown in FIGS. And the current signal 6 of the drive motor 4 of the roller table group 5 having a configuration driven by the drive motor 4 is captured one by one, and the current change behavior causes the motor 4 to reduce the equipment abnormality of the reduction gear 3 and the bearing 2 of the roller 1. In addition, there are provided a roller table equipment diagnosis method and a roller table diagnosis apparatus 7 characterized by diagnosing the presence / absence of roll eccentricity and the amount of eccentricity based on the oscillation cycle and amplitude of current.

FIG. 3 shows the configuration of the roller table diagnostic device 7. The current of the electric motor 4 that drives the roller 1 is detected by the current detector 10, and the current signal 6 from the current detector 10 is input to the roller table diagnostic device 7. The operation signal 11 of the drive motor 4 is also input to the roller table diagnosis device 7 and used as a start command for equipment diagnosis. As for the input current signal 6, the operation signal 11 is input to the diagnostic condition processing unit 17, where a start command for equipment diagnosis is output, and the starting state detecting unit 18 first reaches the starting current value and the rated current of the drive motor 4. The start time up to is calculated, and one is sent to the abnormality determination processing unit 15 and the other is sent to the abnormality determination value generation unit 19 to accumulate data, and is transmitted to the abnormality determination value generation unit 19 based on the accumulated past data. Then, a standard deviation value is calculated to create a judgment reference value, and the result is sent to the abnormality judgment processing unit 15 and compared with a signal from the activation state detection unit 18 to determine whether the operation is normal or abnormal. When the determination is completed, the diagnostic condition processing unit 1
7 outputs a diagnosis start command to the roll eccentricity detection unit 20 to perform the next diagnosis.

The roll eccentricity detecting section 20 includes a filter processing section 12, a peak-to-peak detecting section 13 and a cycle / amplitude calculating section 14, and the driving motor 4 is stable in a no-load state during a stable period. The average current of the current signal 6 at
The maximum value and the minimum value are calculated, the cycle and the amplitude of the current waveform are calculated by a method described later, and the abnormality determination processing unit 15 compares the current value with the abnormality determination value set in advance by the setting monitoring device 9 to perform the abnormality determination.

The result of the abnormality determination processing section 15 is output from the transmission processing section 16 to the setting monitor 9 as an external device via the transmission line 8. Here, the setting monitoring device 9 inputs a judgment reference value and sets a diagnosis condition (diagnosis cycle, diagnosis range, diagnosis method, abnormality judgment value, etc.) for each current signal to the diagnosis condition processing unit 15. A general-purpose computer or control device may be used as long as it has a function of displaying and storing diagnostic results, and a general-purpose serial or parallel transmission or high-performance network may be used for the transmission line 8. Well, they belong to the free design scope of the present invention.

Next, when the drive motor 4 is operated, the current signal 6 and the operation signal 11 are input to the roller table diagnostic device 7, and the starting current waveform at this time is as shown in FIG. 18 and the activation state detection unit 1
At step 8, the starting current Is and the starting time Ts are measured. The starting current Is is the maximum current value immediately after starting, and is the driving motor 4
Connected to the load (reducer 3, bearing 2, roller 1
And the like, and is uniquely determined by the inherent electric characteristics of the drive motor 4, so that the starting current Is
By diagnosing the value of (1), diagnosis of the electric motor alone (diagnosis of abnormality such as disconnection or short circuit of the primary winding or the secondary winding) becomes possible.

After the start current Is flows, the current decreases in accordance with the load condition in addition to the characteristics of the drive motor 4, and the start time Ts until the drive motor 4 reaches the rated current It.
Is measured. Since the start-up time Ts changes depending on the state of the load, it is possible to catch an abnormality on the load side at the start-up time by diagnosing the start-up time Ts. For example, when the shaft of the roller 1 is broken or the like, the load on the drive motor 4 is reduced, so that the start-up time is shortened as Ts'. For example, the startup time becomes longer as Ts "because the load on the drive motor 4 increases. The values (the startup current Is and the startup time Ts) measured by the startup state detector 18 are sent to the abnormality determination processor 15. The determination is made by comparing a normal or abnormal state with a determination reference value determined by an abnormality determination value generation unit 19 described later.

The running state detecting unit 1 receives the operation signal 11 and
When the abnormality determination processing unit 15 completes the determination of the measurement signal at 8, the diagnosis condition processing unit 17 determines a predetermined delay time Td.
(This processing is completed by the detection unit 18 from the conduction state of the operation signal 11 until the current signal 6 reaches the rated current It of the drive motor 4, but the current in the no-load state of the drive motor 4 is the rated current. (It is provided because it is much smaller than It. Usually, it is preferably 1 to 10 seconds.) After that, a diagnosis start command is sent to the roll eccentricity detection unit 20. With this signal, in the roll eccentricity detection unit 20, the current waveform in which the current signal 6 is stabilized is input to the filter processing unit 12 as shown in FIG. At this time, since the current signal 6 contains external noise and the like, the filter processing is performed by the filter processing unit 12 at a preset frequency f [Hz], and the current signal 6 has a predetermined constant value. The maximum value Imax, the minimum value Imin, and the average value Iave of the cycle (usually 2 to 4 seconds) are calculated. Frequency f [Hz] to be filtered
Can be easily obtained by the following equation using the rotation speed N [rpm] of the roller 1. f [Hz] = (N [rpm] / 60) ± α (1)

Here, α is for performing a filtering process by giving a certain width to the obtained frequency f. The grease and lubricating oil of the bearing 2 supporting the roller 1 and the speed reducer 3 are used. This is provided because the rotation speed of the drive motor 4 fluctuates when the load on the drive motor 4 increases due to the shortage, and is usually provided at about 20% of the obtained frequency f.
Good to be. As a result, the result of removing noise included in the current signal 6 is sent to the peak-to-peak detection unit 13 as shown in FIG.

On the other hand, since the average value Iave obtained at a constant period with respect to the current signal 6 is a stable current which is not affected by the load fluctuation due to the steel material to be conveyed, the average value Iave is diagnosed to determine the operating state. Of the load (the reduction gear 3, the bearing 2, the roller 1, etc.) including the drive motor 4 in the above. For example, when the axis of the roller 1 is broken, the load on the drive motor 4 is reduced, so that the average value I
The value of ave decreases, and the average value Iave increases due to an increase in load due to a shortage of lubricating oil and grease in the reduction gear 3 and the bearing 2. The values (maximum value Imax, minimum value Imin, average value Iave) measured by the filter processing unit 12 are determined by the abnormality determination processing unit 15 as to whether they are normal or abnormal.
The determination is made by comparing with a determination reference value determined by an abnormality determination value generator 19 described later.

As a method of measuring the oscillation period of the current waveform, for example, it is general to measure the time between points at which the current signal intersects the average value Iave obtained by the filter processing unit 12, for example. In this method, only the period is obtained, and the amplitude must be obtained by another method. Therefore, in the present invention, as shown in FIG. 4B, the peak-to-peak detecting unit 13 detects a point where the current change ΔI / Δt changes from minus to plus and a point from plus to minus,
The period / amplitude calculator 14 calculates the current difference Ip-p between the two points.
And the time difference Tp are measured at the same time, and the oscillation cycle is calculated as the time difference Tp ×
2 and the amplitude is obtained as the current difference Ip-p. This calculation result (average value Iave, cycle Tp × 2, amplitude Ip-p)
Is sent to the abnormality determination processing section 15 and is compared with a determination reference value Tb determined in advance by the method described below to determine an abnormality. Judgment reference value Tb [s] = (60 / N [rpm]) ± β (2)

Here, .beta. Is used to compare the obtained reference value Tb with a certain width, and this is for avoiding an error caused by the period of taking in the current signal 6 of the drive motor 4. Normally, it is desirable that the period for taking in the current signal 6 be three times or more in the range of 5% to 10% of the obtained reference value Tb. The above formulas (1) and (2) are used by the setting monitoring device 9 to determine the main specifications (rated speed, etc.) of the drive motor 4, the reduction ratio of the speed reducer 3, the outer diameter of the roller 1 and the like. Is input, the setting monitoring device 9 is set in advance.
If the result is sent to the filter processing unit 12 via the transmission processing unit 16 and the diagnosis condition processing unit 17, the processing in the roller table diagnosis device 7 can be reduced.

The eccentricity of the roller 1 means that the center of gravity moves with respect to the center axis of the roll, and when the roll rotates in this state, the current pulsates in the rotation cycle of the roll,
The pulsation amplitude of the current indicates the fluctuation of the load torque due to the eccentric amount of the roll. Therefore, the abnormality determination processing unit 1
In 5, the load current characteristics of the drive motor 4 in consideration of the amount of eccentricity of the roll and the reduction ratio of the speed reducer 3 are created as shown in FIG. 6 and compared with the results obtained by the cycle / amplitude calculation unit 14. This makes it possible to diagnose whether or not the roller 1 is eccentric and the amount of eccentricity. In addition, the diagnosis result is sent to the setting monitoring device 9 via the transmission processing unit 16 and monitored, and particularly, by monitoring the tendency of the amount of change in the eccentric amount, it is effective in determining the roll replacement time and the like. become.

In such an equipment diagnostic apparatus, a method of determining a reference value for judging an abnormality with a value measured and calculated by the activation state detecting unit 18 and the filter processing unit 12 and comparing the values is performed. The setting has a great effect on the diagnostic accuracy, and the determination of the reference value is extremely difficult as described above. In addition, the diagnostic cycle of the roller table diagnostic device 7 (usually 10 ms to 40 ms)
The measured value of the current signal 6 varies.

Therefore, according to the present invention, the activation state detector 18
And the value obtained from the filter processing unit 12 (starting current Is
, The start time Ts, and the average value Iave) of the past n data are collected and stored in the abnormality determination value generation unit 19, and a standard deviation is determined based on the stored data to create a determination standard. For example, in the method of determining the criterion for determining the starting current Is, the past n times (depending on the device configuration of the roller table group 5, the calculation accuracy of the reference value is ensured and the roller table diagnostic device 7 is used).
Starting currents Is (0), Is (1), Is (2),..., Is (n-1),
Is (n) is accumulated, the average value Is (ave) and the standard deviation σ are obtained in the abnormality determination value generation unit 19, and the determination reference values are determined as abnormal values, for example, Is (ave) + 3σ and Is (ave) -3σ. Attention warning (light failure), Is (ave) + 4σ and Is (ave) -4
It is determined as a facility abnormality alarm (major failure) by σ, sent to the abnormality determination processing unit 15, and compared with the measured value Is of the activation state detection unit 18. Here, the average value Is (ave) of 3σ and 4σ is used as a reference, but may be adjusted according to the characteristics of the drive motor 4 and is a free design range of the present invention.

Similarly, for the activation time Ts of the activation state detection unit 18 and the average value Iave of the filter processing unit 12, the standard deviation value is obtained based on the past n data. Values can be created automatically. Here, the number of data stored in the abnormality determination value generation unit 19 has been described as n consecutive data in the past, but the number of data need not always be continuous. This is because, for example, the average value Iave of the stable current under no load condition
When the abnormality determination reference value is determined, assuming that the cycle of taking the current signal 6 into the roller table diagnostic device 7 is 10 ms and the number of data is n = 300, the past actual time referred to for determining the abnormality determination reference value is 3 s. In short, the past operation history is not necessarily referred to, and an effective determination criterion cannot be created. Therefore, the validity is lost as a reference value.

However, the present invention intends to use a statistical method for obtaining a standard deviation which is a variation of the past data obtained by the activation state detecting unit 18 and the filter processing unit 12, so that the obtained past past method is used. If continuous data is considered as a population, it is only necessary to randomly sample n data from the population to obtain a deviation value, and continuous data is not necessarily required. As the specific method, the activation state detection unit 18 and the filter processing unit 1
A method of using the random number generator that randomly generates numbers from 0 to 1 to the data obtained in step 2 and storing the data in the abnormality determination value generation unit 19 only when the value of the random number generator is 0.9 or more Alternatively, there is a method in which a long time timer (for example, 10 to 90 minutes) periodically accumulates in the abnormality judgment value generation unit 19, whereby the judgment reference value is calculated by the number n of data accumulated in the abnormality judgment value generation unit 19. If found, a highly effective reference value with reference to the past long-term operation history can be found. Thereby, the activation state detection unit 18 and the filter processing unit 1
The historical long-term history data obtained in 2 is used as a population,
It is necessary to determine a reference value by trial and error as in the prior art because it is possible to automatically create a judgment reference value by collecting n data from the data and calculating a deviation value that is a variation thereof. Therefore, the determination reference value can be obtained simply and reliably.

As an example of the diagnosis of the roller table according to the present invention, the roll diameter is 350 [mm] and the roll length is 215.
The current signal 6 is extracted by the current detector 10 from the drive motor 4 of the roller table group 5 composed of a plurality of roller tables for driving the roller 1 having a roll speed of 136 [rpm] by the drive motor 4 at 0 [mm]. The current signal 6 and the operation signal 11 are input to the roller table diagnostic device 7 as shown in FIGS. For example, if the eccentricity of the roll is 18
The current signal 6 at the time of [mm] is as shown in FIG. 5, and the filter processing unit 12 calculates the current signal from 1.81 to 2.72 based on the calculation result described above.
[Hz] filter processing to remove noise, and the peak-to-peak detection unit 13 and the cycle / amplitude calculation unit 14
Of 0.42 [sec] and an amplitude of 3.2 [A] are obtained.

The abnormality determination processing unit 15 determines from the characteristic diagram shown in FIG. 6 that the relationship between the roll eccentricity and the load current is predetermined, when the current amplitude is 3.2 [A].
[Mm] can be obtained. This value was almost equivalent to the actually measured value of the roll eccentricity of 18 [mm], and a result having no practical problem was obtained. The vibration cycle is 136 [rpm
When the rotating roll is eccentric, the calculated value is 0.4
It vibrates at 41 [sec], and the method according to the present invention secures sufficient accuracy and makes it possible to diagnose the equipment of the roller table.

[0028]

According to the present invention, a current signal and an operation signal of a driving motor are input, and the motor is diagnosed by a starting current immediately after the operation, and the current is stable in a no-load state after the starting of the motor. Sometimes, by calculating the oscillation cycle and amplitude of the current signal, and comparing it with a determination reference value determined by the roll specification, it is possible to diagnose a plurality of roller tables, and the reference value of the abnormality determination is determined in the past. Automatically created from the operation history data of the above, it can be widely applied to equipment diagnosis of a roller table group for transporting steel materials such as the steel industry. Further, according to the present invention, since the equipment diagnosis can be performed only by the current signal and the operation signal, an expensive detector is not required, and the number of diagnosis targets is further reduced.
By limiting to a point, the processing capability of the diagnostic device can be designed to be low, so that it can be manufactured as a low-cost small diagnostic device, and a portable diagnostic device can be manufactured by using a portable type.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a device configuration of a roller table.

FIG. 2 is a configuration diagram illustrating an example of performing equipment diagnosis of a roller table according to the present invention.

FIG. 3 is a configuration diagram showing an example of a configuration of a roller table diagnostic device according to the present invention.

FIG. 4 is a diagram showing an example of a current waveform for explaining a roller table diagnosis method according to the present invention.

FIG. 5 is a current waveform diagram showing an example of diagnosing roll eccentricity in the embodiment according to the present invention.

FIG. 6 is a graph showing an example of a current amplitude-eccentricity graph created for obtaining a roll eccentricity in an embodiment according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 roller 2 bearing 3 reduction gear 4 drive motor 5 roller table group 6 current signal 7 roller table diagnostic device 8 transmission line 9 setting monitoring device 10 current detector 11 operation signal 12 filter processing unit 13 peak-to-peak detection unit 14 cycle / amplitude Calculation unit 15 Abnormality determination processing unit 16 Transmission processing unit 17 Diagnosis condition processing unit 18 Activation state detection unit 19 Abnormality determination value generation unit 20 Roll eccentricity detection unit

Claims (5)

[Claims] In a roller table group for conveying a steel material by driving a cylindrical roll by an electric motor, a current state of the electric motor for driving the roll is captured one by one, and a starting current and a starting time immediately after the operation are detected. It has a detection unit and a current change detection mechanism composed of a roll eccentricity detection unit that detects the current value in the stable period and calculates the oscillation period and amplitude of the current, and sequentially detects each detection unit according to the operation signal of the electric motor. A roller table equipment diagnosis apparatus characterized in that the roller table is continuously diagnosed by changing over the current change behavior of the motor in accordance with the operation state from the start to the stop of the operation. 2. A roller table group for conveying a steel material by driving a cylindrical roll by an electric motor, wherein a current signal of the electric motor for driving the roll is captured one by one and obtained by a starting state detecting unit and a roll eccentricity detecting unit. Accumulate the obtained past detection results, find the standard deviation from the past measured values, the roller table characterized in that it has an abnormality determination generation unit that automatically determines a reference value to determine the abnormality of the roller table equipment Equipment diagnostic equipment. 3. A current signal of the electric motor immediately after driving the roller table by the starting state detecting unit is captured by an operation signal, and a time required to reach a maximum value of the starting current at that time and a rated current determined by the specification of the driving motor is obtained. By measuring a certain start-up time and comparing these measured values with the abnormality determination reference value determined by the abnormality determination generation unit, it is possible to diagnose the coupling, reduction gear and roll bearing equipment abnormality from the motor alone. Roller table equipment diagnosis method. 4. A motor for driving a roll by a roll eccentricity detection unit, in a stable period in which no load is loaded on a roller table after a motor is completely started, and in which a current signal of the motor is set to a maximum current for a predetermined period. By measuring the value, the minimum current value and the average current value, and comparing these measured values with the abnormality determination reference value determined by the abnormality determination generation unit, coupling of the motor,
A method for diagnosing equipment of a belt conveyor, comprising diagnosing equipment abnormality of a reduction gear and a bearing of a belt drive pulley. 5. A pulsating current of a load current of a drive motor when a roll eccentricity is detected by a roll eccentricity detecting unit. The current difference and time between the two points which become 0 are detected, and the pulsating cycle and amplitude of the current are calculated by the calculating unit, and the pulsating cycle and the amplitude are determined based on the specification of the roller table (roll rotation speed, roll diameter, etc.). A method for diagnosing the equipment of a roller table, characterized by diagnosing the presence and size of roll eccentricity by comparing.