TWI624670B - Insulation monitoring device of rolled material conveying part - Google Patents

Abstract

The insulation monitoring device of the rolling material conveying unit of the present invention includes a terminal box for manual measurement, and constitutes a first voltage dividing circuit, and the first voltage dividing circuit includes induction heating disposed on the heating rolled material. The insulation resistance of the insulating transfer portion before and after the device serves as one of the resistors for dividing the voltage of the power supply for measurement; and the automatic measurement circuit constitutes a second voltage dividing circuit, and the second voltage dividing circuit is provided by the foregoing The insulation resistance is one of the resistors that divide the voltage of the power supply for measurement. Thereby, the insulation state of the insulating conveying portion is monitored safely and accurately.

Description

Insulation monitoring device for rolling material conveying unit

The present invention relates to an insulation monitoring device for a rolled material conveying portion.

Generally, in the hot rolling mill production line, the rolled product is heated to a temperature at which rolling can be carried out by a heating furnace, and is formed into a slab by rough rolling of a rough rolling mill. Further, the slab is further sent to the finishing rolling mill, whereby a product formed into a desired thickness is obtained.

In the hot rolling line as described above, the temperature drop occurs before the slab reaches the finishing pass. In this regard, an induction heating device is provided for the purpose of raising the temperature of the slab or maintaining the uniform temperature. For example, since the temperatures of both end portions in the width direction of the slab are particularly likely to be lowered, an edge heater for raising the temperature of both end portions in the width direction of the slab is provided.

For example, an induction heating device is disposed at both ends of the slab as an edge heater. The magnetic flux generated by the heating coil of the induction heating device is interlinked with the slab to generate an eddy current, and the slab is heated by the Joule heat caused by the eddy current.

At this time, the eddy current generated in the slab becomes the shaft current and It is transferred from the slab to the table roll and flows to the ground. When the slab is in stable contact with the conveying roller, there is no particular problem, and the contact between the slab and the conveying roller may be unstable due to the up and down vibration during the conveyance of the slab, the distortion of the slab itself, and the like. At this time, there is a problem that the slab and the conveying roller form a crater due to the discharge of the slab at the moment of leaving the conveying roller. For such a problem, for example, a proposal of Patent Document 1 has been proposed.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-286248

If the conveying roller is in an insulated state, the generation of the shaft current can be suppressed. Therefore, it is effective to monitor the insulation state of the conveying roller daily or periodically.

It is difficult to maintain the insulation of the conveying roller constantly due to the slab scale, the rust-removing water falling, and the hot and humid environment of the rolling line. Although it is necessary to periodically remove rust, dust, and the like, if the insulation state of the conveying roller is checked daily or periodically, the tendency of the insulation to be reduced can be grasped, and the conveying roller of the maintenance object can be made bright. According to the embodiment described below, an insulation monitoring device is provided to safely and accurately monitor the insulation state of such a conveying roller (insulation conveying portion).

According to an aspect of the present invention, a rolled material is provided The insulation monitoring device of the delivery unit includes a terminal box for manual measurement, and constitutes a first voltage dividing circuit, and the first voltage dividing circuit includes an insulating transmission disposed before the induction heating device for heating the rolled material The insulation resistance of the portion is one of the resistors for dividing the voltage of the power supply for measurement; and the automatic measurement circuit constitutes a second voltage divider circuit, and the second voltage divider circuit includes the insulation resistance as a quantity One of the resistors for measuring the voltage division of the power supply voltage.

The frequency of inspection cleaning and the amount of work around the insulating conveyance unit can be efficiently calculated.

1‧‧‧ bearing

2‧‧‧Insulation board

3‧‧‧Rolling material (slab)

4‧‧‧Conveying roller

5‧‧‧Manual measuring terminal box

6‧‧‧Tester

7‧‧‧Measurement terminals

8‧‧‧ analog input unit

9‧‧‧Control Department

10‧‧‧Induction heating device

11‧‧‧ display device

13a‧‧‧Rolling material detection sensor

13b‧‧‧Rolling material detection sensor

14‧‧‧Measurement roller

20a‧‧‧Transport Department

20b‧‧‧Transportation Department

21‧‧‧Support Department

50‧‧‧Automatic measurement circuit

90‧‧‧Wiring

I1‧‧‧ Current

R1‧‧‧ resistance

R3‧‧‧ resistance

Rn‧‧‧resistance

R2‧‧‧Insulation resistance

SW1‧‧‧ connection point (switch)

SW2‧‧‧ connection point (switch)

SW3‧‧‧ connection point (switch)

V _DC ‧‧‧Power supply voltage

Vn‧‧‧ voltage

Fig. 1 is a schematic view showing the configuration of an insulation monitoring device of an embodiment.

Fig. 2 is a schematic view of an insulating conveying unit.

Fig. 3 is a schematic view showing the connection between the manual measurement terminal box and the insulating transfer portion in the embodiment.

Fig. 4 is a circuit diagram showing the concept of an automatic measuring circuit of the embodiment.

Fig. 5 is a schematic view showing the configuration of an insulation monitoring device of the embodiment.

Figure 6 is a schematic view of the rolling stock transfer line.

Figure 7 is a schematic diagram of the rolling stock transfer line.

Fig. 8 is a table showing the conditions for performing the insulation monitoring measurement of the embodiment.

Fig. 9 is a graph showing a data processing example of the insulation monitoring measurement data of the embodiment.

Fig. 1 is a schematic view showing the configuration of an insulation monitoring device of an embodiment.

The insulation monitoring device according to the embodiment includes a manual measurement terminal box 5 and an automatic measurement circuit 50. As will be described later, the manual measurement terminal box 5 constitutes a first voltage dividing circuit, and the automatic measuring circuit 50 constitutes a second voltage dividing circuit.

Fig. 7 is a schematic view showing a rolling stock conveying line of the embodiment.

Fig. 7 shows a transfer line between a rough rolling mill and a finishing mill, for example, in a hot rolling line. The rolled material (slab) 3 which has been subjected to the rough rolling is conveyed to the plurality of insulating conveyance portions 20a and the plurality of conveyance portions 20b from right to left in Fig. 7 .

An induction heating device 10 is disposed on the transfer line. For example, two induction heating devices 10 are shown in FIG. The induction heating device 10 heats both ends of the rolled material (slab) 3 in the width direction (the depth direction of the paper surface).

The plurality of insulating conveying portions 20a and the plurality of conveying portions 20b include a plurality of insulating conveying portions 20a disposed before and after the induction heating device 10 (upstream side and downstream side in the conveying direction). In Fig. 7, for example, five insulating conveying portions 20a are disposed in front of and behind the induction heating device 10.

Fig. 2 is a schematic view of the insulating conveying unit 20a.

The insulating conveying unit 20a includes a conveying roller 4, a bearing 1 that rotatably supports the conveying roller 4, and a support portion 21 that supports the bearing 1 on the ground. The plurality of conveying rollers 4 are separated from each other and arranged in the conveying direction of the rolled web 3.

The conveying roller 4, the bearing 1, and the support portion 21 are made of metal which is suitable for conveying the sufficient strength of the rolled and rolled material 3. The insulating plate 2 is sandwiched in the support portion 21. The insulating plate 2 insulates the ground from the conveying roller 4.

Both ends of one transport roller 4 are supported on the ground via the bearing 1 and the support portion 21, respectively. Each of the support portions 21 at both ends of the conveying roller 4 has an insulating plate 2 interposed therebetween. In the region other than the front and rear regions of the induction heating device 10, there is no concern that the shaft current is generated. As shown in Fig. 7, the conveying portion 20b not having the insulating plate 2 is disposed in the region where the shaftless current is generated.

Fig. 3 is a schematic view showing the connection between the terminal box 5 for manual measurement and the insulating transfer portion 20a.

The terminal box 5 for manual measurement includes a tester 6 and a plurality of measurement terminals 7. Alternatively, the tester 6 may not be standing in the terminal box 5 for manual measurement, and may be transported to the terminal box 5 for manual measurement when measured by the measurer.

The conveying area of the rolled web 3 is a dangerous area, so a safe passage is provided. The terminal box 5 for manual measurement is disposed at a place away from the transport area, for example, in the vicinity of a safety passage or a safety passage.

The wiring 90 is connected to the insulating conveyance portion 20a so as to bridge the insulating plate 2 of the support portion 21 of the bearing 1. This wiring 90 is laid down to the manual measurement terminal box 5 and connected to the measurement terminal 7. correspond A plurality of measurement terminals 7 are provided at a portion where the insulation measurement is to be performed (a plurality of insulating plate installation portions). The plurality of measurement terminals 7 electrically connected to the plurality of insulating conveyance portions 20a are collected in the manual measurement terminal box 5 provided at a place away from the conveyance region. The measurer uses the tester 6 instead of the manual measurement terminal box 5 to perform insulation measurement. Even when the rolled web 3 is transported, the measurer can safely measure the insulation.

The terminal box 5 for manual measurement constitutes a first voltage dividing circuit, and the first voltage dividing circuit includes: a power supply for measurement (battery inside the tester 6); and a power supply voltage of the first voltage dividing circuit The divided resistor (resistance inside the tester 6) and the insulation resistance of the insulating transfer portion 20a.

Fig. 4 is a circuit diagram showing the concept of the automatic measuring circuit 50.

The automatic measurement circuit 50 follows the circuit of a general analog tester. This is because the tester is generally used in the case of manual measurement, and it is preferable that the measurer can manage and evaluate the measured value from the same viewpoint whether it is manual measurement or automatic measurement. .

Here, the resistance measurement using the tester is briefly described. The voltage is measured by using a dry battery inside the tester to pass a current through a multiplying resistor inside the tester and flowing through the voltage dividing circuit of the measuring object, and displays a voltage corresponding to the current flowing through the multiplying resistor inside the tester. The meter operates according to the current generated corresponding to the voltage and the resistance inside the tester, and corresponds to the current, and displays the value of the Ω number.

Fig. 5 is a schematic view showing the insulation monitoring device after the manual measurement terminal box 5 is removed from Fig. 1.

The automatic measuring circuit 50 constitutes a second voltage dividing circuit, and the second voltage dividing circuit includes: a measuring power source (DC power source); a resistor R1 that separates the power source voltage V _DC of the measuring power source and the insulation The insulation resistance R2 of the conveying portion 20a; and the analog input unit 8. The insulation monitoring device further includes a control unit 9 and a display device 11.

Here, the current flowing through the terminal connected to the analog input unit 8 in the second voltage dividing circuit is set to I1, the voltage of the terminal is set to Vn, and the resistance value of the terminal is set to Rn, and the analog input unit is used. When the internal resistance of 8 is set to R3, the following equation holds. However, in general, since the resistance value R3 of the analog input unit 8 is very high, in the calculation formula, even if it is ignored, it does not have much influence.

I1=V _DC /(R1+Rn)

Rn=R2×R3/(R2+R3)... is set as a synthetic resistor for easy calculation

I1=Vn/Rn

Vn/Rn=V _DC /(R1+Rn)

Vn × (R1 + Rn) = V _DC × Rn

Rn=Vn/(V _DC -Vn)×R1...insulation resistance value including the internal resistance of the analog input unit 8

R2 = 1 / (1/Rn-1 / R3) ... does not contain the insulation resistance value of the internal resistance of the analog input unit 8

The control unit 9 calculates the resistance value Rn based on the voltage Vn input to the analog input unit 8 in the automatic measuring circuit 50 and the above-described calculation formula Vn/(V _{DC -} Vn) × R1. The control unit 9 can output the calculated value as the insulation resistance value of the insulation state of the insulating transfer unit 20a to the display device 11 (display screen).

Further, the control unit 9 can compare the insulation resistance value obtained from the automatic measurement circuit 50 with the management value, and output the comparison result to the display device 11.

Fig. 9 is a graph showing a data processing example of the insulation monitoring measurement data processed by the control unit 9.

Figure 9 shows the time variation of the insulation resistance value. Further, when the insulation resistance value is lower than the management value (threshold value), the display device 11 may output a warning.

In the rolling line, the conveying roller 4 of the insulating conveying portion 20a disposed before and after the induction heating device 10 is generally internally water-cooled. In order to ensure the insulation of the induction heating device 10 belonging to the electric appliance, the outer water for cooling the conveying roller is not interfered with the induction heating device 10. Therefore, the internal water-cooled conveying roller 4 disposed before and after the induction heating device 10 does not obtain the insulation resistance value of the million ohm class required by the general electric appliance, but is several thousand ohms. Therefore, the management value of the above insulation resistance can be set, for example, to 1 kΩ or more and 2 kΩ or less.

Here, as shown in Fig. 6(a), when the rolled product 3 is placed in the state of the transport roller 4 of the measurement target and the other transport roller 4, as shown by the broken line, the plurality of transport rollers are An electrical loop (circuit loop) will be formed between 4. This is the cause of the decrease in the measurement accuracy of the insulation resistance.

Further, when the induction heating device 10 is turned on, the induced current indicated by a broken line in Fig. 6(b) flows to the ground through the rolled web 3.

In other words, when the insulation resistance measurement of the insulating transfer unit 20a is performed, factors such as the induced current during the operation of the induction heating device 10 and the transport roller 4 on which the rolled material 3 is placed are measured, which causes the measurement accuracy to decrease. Interference factor.

In the manual measurement, the measurer visually confirms that the stop of the induction heating device 10 and the state in which the rolled material 3 is not placed on the conveyance roller 4 of the measurement object, and the measurement is performed, and the measurement disturbance can be avoided.

On the other hand, in the measurement using the automatic measuring circuit 50, the state in which the stop of the induction heating device 10 and the conveying roller 4 in which the rolled material 3 is not placed on the measuring object can be set in a logical state, and is reflected in Measurement instructions.

In other words, the control unit 9 performs the state in which the induction heating device 10 is turned off and the state in which the rolled material 3 is not placed on the transport roller 4 of the measurement target, and is executed by the automatic measuring circuit 50. The measurement of the insulation resistance of the insulating transfer portion 20a of the measurement target.

As shown in Fig. 7, in the rolling line, in order to carry out the conveyance control of the rolled material 3, the rolled material detecting sensors 13a and 13b and the measuring roll (pulse counter) 14 are provided. The measuring roller 14 calculates the conveying speed of the rolled web 3. The rolled material detecting sensors 13a, 13b are, for example, a hot metal detector or a thermometer.

In Fig. 7, five insulated conveying rolls (insulating rolls) 4 are exemplified. In addition, No. 1, No. 2, No. 3, No. 4, and No. 5 are sequentially attached to the five insulating rolls 4 from the upstream side in the conveyance direction of the rolled material 3.

Attachment of the insulating roller 4 on the most upstream side indicated as No. 1. Nearly, the rolled material detecting sensor 13a on the inlet side is provided. In the vicinity of the insulating roller 4 on the most downstream side indicated as No. 5, a rolled material detecting sensor 13b on the outlet side is provided. When the rolled material 3 is not placed on each of the five insulating rolls 4, both the rolled material detecting sensor 13a on the inlet side and the rolled material detecting sensor 13b on the outlet side are turned off.

According to the monitoring device using the automatic measuring circuit 50, the control unit 9 outputs a measurement command when it is detected that the rolled material 3 is not placed on the insulating roller 4 to be measured and the induction heating device 10 is not operated. Due to the output of the measurement command, the connection points (switches) SW1, SW2, and SW3 shown in FIG. 5 are turned on, and the automatic resistance measurement of the insulating transfer portion 20a of the measurement target is performed.

Fig. 8 (a) and (b) show the conditions for the execution of the insulation monitoring measurement (conditions of the output measurement command).

Fig. 8(a) shows the common conditions for the five insulating rolls 4.

That is, when the induction heating device 10 is turned off, the rolled material detecting sensor 13a on the inlet side is turned off, and the rolled material detecting sensor 13b on the outlet side is turned off, the five insulating rolls 4 can be turned on. Any one of the insulating rolls 4 outputs a measurement command.

Fig. 8(b) shows a case where conditions are imposed on the respective insulating rolls 4.

In the characteristics of the rolling operation, a plurality of rolled webs (slabs) 3 are usually conveyed one by one without interruption, and thus it is difficult to occur in the case where all of the insulating rolls 4 are not placed on the rolled web 3 .

At this time, the sensors 13a, 13b are detected from the rolled material. And tracking information of the rolled material 3 obtained by the measuring roller 14 to detect which of the insulating rolls 4 that the rolled material 3 is currently traveling to No. 1 to No. 5, for example, can be set to pass through the rolled material 3 The insulating roller 4 on the upstream side sequentially measures the timing.

For example, the turn-off detection of the rolled material detection sensor 13a on the inlet side, the conduction detection of the rolled material detection sensor 13b on the outlet side, and the distance calculation based on the measuring roller 14 can be performed. It is detected that the trailing end of the rolled web 3 has passed through the insulating roll 4 of No. 1. When the detection is passed, the control unit 9 turns on the measurement command for the insulating roller 4 of No. 1.

According to this method, it is not necessary to stop the rolling operation, and the insulation measurement of the insulating roller 4 can be performed even in the rolling operation.

According to the insulation monitoring device and the monitoring method of the embodiment described above, it is possible to grasp the tendency of the insulation resistance of the conveying roller 4 to decrease in the time series by using a very simple device configuration. This can be used for an efficient inspection of the periodic inspection around the conveying roller 4, the frequency of cleaning, and the amount of work. In addition, it is expected to predict the possibility of arc point generation.

The present invention is not limited to the hot rolling extension line in which the edge heater is provided, and is also applicable to equipment equipment, equipment, and the like having elements for measuring and monitoring the insulation resistance.

The embodiments of the present invention have been described in detail, and the embodiments are not intended to limit the scope of the invention. The present invention can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The embodiments and variations thereof are included in the scope and/or gist of the invention, and include the invention described in the scope of the claims. The scope of the etc.

Claims (4)

An insulation monitoring device for a rolling material conveying unit includes a terminal box for manual measurement, which constitutes a first voltage dividing circuit, and the first voltage dividing circuit includes an induction heating device disposed on a heating rolled material The insulation resistance of the insulating transmission portion before and after is one of the resistors for dividing the voltage of the power supply for measurement; the automatic measurement circuit constitutes a second voltage dividing circuit, and the second voltage dividing circuit includes the foregoing insulation resistance a display device that displays an insulation resistance value obtained from the automatic measurement circuit; and a control unit that compares the insulation resistance value with a management value, and The comparison result is output to the aforementioned display device. The insulation monitoring device of the rolling material conveying unit according to the first aspect of the invention, wherein the control unit receives the off state of the induction heating device, and the rolled material is not placed in the measurement. When the object is in the state of the insulating conveyance unit, the measurement of the insulation resistance of the insulating conveyance unit to be measured by the automatic measuring circuit is performed. The insulation monitoring device of the rolling material conveying unit according to the first aspect of the invention, wherein the plurality of measurement terminals connected to the plurality of insulating conveying units are collected in a conveying area provided away from the rolled material. Before the place The terminal box for manual measurement is described. The insulation monitoring device of the rolling material conveying unit according to the first aspect of the invention, wherein the control unit outputs a warning to the display device when the insulation resistance value is lower than the management value.