KR970002823Y1 - Detection device of edge heater bar wave - Google Patents

Abstract

None.

Description

Bar wave detection device for edge heater of finishing mill

1 is a working situation diagram showing a state where a bar (material) collides with an edge heater inductor of a conventional finishing rolling apparatus.

2 is a working situation diagram showing the bar wave detection apparatus according to the present invention to the edge heater inductor of FIG.

3 is a detailed view of a bar wave detection device according to the present invention.

4 is a detailed circuit diagram of an amplifier circuit included in the bar wave detection device of the present invention.

5 is an operation flowchart of the bar wave detection device of the present invention.

* Explanation of symbols for main parts of the drawings

1: ground sensor 5: spring

11 bar (material) 13: upper inductor

14 lower inductor 15 air cylinder

16: buggy 17: upstream of the bar

18 bar wave 12A bar wave detection device

12B: Amplification Circuit 12C: PLC

The present invention relates to a bar wave detection device which is mounted on an inductor to protect an inductor of a bar edge heater, which is one of the fever rolling facilities of a steel mill in a hot rolling mill. It is used in an induction heating device installed to compensate for temperature drop and improve the flowability of the finishing rolling process and the product quality.

One induction heating device as described above is provided at the work side and the drive side, respectively, and four inductor devices are provided at the work side and four at the drive side. It is installed in the bar through the gap between the inductor and the bar gap 25mm, the thickness of the bar 30mm, the bar running speed 90m / min (normal working conditions in the rolling mill process) is capable of heating up to 60 ℃.

In the conventional induction heating apparatus, the bar etch heater heating principle is that when an alternating current passes through a heating coil installed in an inductor, an overcurrent is induced inside the object to be heated, and Joule heat is generated by the induction current. The bar (material) is configured to be heated.

The heating effect varies depending on the gap between the inductor and the bar of the induction heater, and the larger the gap, the smaller the temperature rise effect, and the smaller the gap, the greater the temperature rise effect. The gap between the bar and the inductor is used in a state of 20 mm in consideration of collision between the and inductor.

In addition, the drive of the baggage, which can control the position according to the width of the bar, can be moved forward and backward by using the AC motor, and the gap-open and gap-close of the inductor are operated by the air-cylinder. All of these controls are controlled by PLC (Programmable Logic Control), but when the upper part of the bar (material) is generated upward or the middle wave of the bar is intermittently generated, the bar (material) and the inductor collide, resulting in damage to the inductor. And there have been frequent cases of insulation damage, but there was no way to prevent it.

In order to prevent the inductor and the bar from colliding with the bar edge heater when the top of the bar is upward, the bar is preheated in the inductor gap-open state 3 mm before entering the edge heater, and the top of the bar passes through the inductor completely. After that, the inductor is closed by the air cylinder so that it is normally heated.

However, when the inductor is open in the case of a high upward occurrence of the bar, even though the inductor is open (303 mm from the ruler table to the upper inductor face and 273 mm in consideration of the bar thickness of 30 mm), the inductor and the bar upper part collide with each other and the inductor is broken Is generated.

In addition, the inductor is in the gap-closed state and the wave is generated in the middle of the bar during the normal heating (25 mm gap between the inductor and the bar) (bar state after the rough rolling is wave-like) and the inductor Is frequently collided and the inductor breaks and the insulation is damaged, resulting in a poor product quality due to the inability to use the edge heater.

Accordingly, an object of the present invention is to provide a bar wave detection device for preventing a bar collision between the inductor and the bar in the heating of the bar edge heater, an apparatus equipped with a sensor that can detect the wave in the upper and middle of the bar When the sensor is in operation, the inductor heating is stopped, the inductor is gap-opened and the buggy is evacuated to the rear from the heating position to prevent collision with bars and inductors to prevent inductor damage and This is to prevent failure in advance.

Hereinafter, a bar wave detection device of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a state where an edge heater inductor of a conventional finishing rolling device collides with a bar (material) that proceeds in a gap-closed state. It means a normal heating state, and a gap-open state means a state in which the inductor stops heating with respect to the progressing bar.

Reference numeral 11 denotes a bar, and an arrow marked on the bar 11 indicates the direction of travel of the bar (material). The bar 11 advances in the direction of the arrow by the roller table 19 at a normal traveling speed of 90 mpm.

As shown in the drawing, an induction heating device for improving the mail flowability and product quality of the finishing rolling process by compensating for the temperature drop of the edge portion of the bar (material) 11 subjected to the rough rolling process in a steel mill hot rolling mill. The edge heaters are provided at the work side and the drive side end, respectively.

The edge heater has two upper inductors 13 and two lower inductors 14 on the wit side, which can directly generate magnetic flux to heat the material, and the four inductors 13 on the drive side as well. , 14).

It also includes an air cylinder 15 for lifting and gap-closing the upper inductor 13 of its edge heaters, where the inductors 13 and 14 always heat the edge of the bar to heat the edge of the bar. And a trolley 16 capable of moving forward and backward for automatic position control according to the width.

However, it could not be prevented that the intermittent upward portion 17 of the bar 11 and the wave portion 18 of the intermediate portion collide with the inductor 13 of the edge heater.

Therefore, in order to prevent the above problems, as shown in FIG. 2, the wave detection device 12A having the ground sensor 1 according to the present invention in the upper inductor 13 is a work shaft edge heater. And inductors of the drive side edge heaters, respectively. The bar wave detection device 12A is shown in more detail in FIG.

In Fig. 3, reference numeral 12A denoted as a whole is a bar wave detection device, 1 is a ground sensor, 2 is a frame, 3 is a conduit, 4 is a wire, and 5 is a spring.

When the wave of the bar is touched by the spring 5, it is sensed by the ground sensor 1, and the detected signal is transmitted to the amplifying circuit 12B of FIG. 2 through the wire 4, and the amplifying circuit 12B. Signal is amplified by the PLC to the programmable logic control (12C) to direct the proper command of the edge heater. The bar wave detection device has a height of 950 mm and a length of 185 mm.

Referring back to FIG. 2, the work detection device 12A mounted on each inductor of the work side and the drive side respectively has the end of the spring 5 of the ground sensor 1 facing the top inductor 13 of the edge heater. If the upper part 17 of the bar 11 is generated after the rough rolling process or the wave 18 is generated in the middle of the bar after the rough rolling process, the waved part is the spring of the ground sensor 1. Touched by (5), the sensed signal is transmitted to the amplifying circuit 12B through a cable therein, and the amplified signal through the amplifying circuit is again a programmable logic control (PLC) that controls all operations of the edge heater. 12C).

Upon receiving the signal, the PLC 12C immediately gives an open command to the inductor air cylinder 15 of the edge heater to gap-open the inductor gap, and at the same time, a reverse command is given to the bogie 16 to back the bogie 16. To evacuate to the home position and check whether the ground sensor 1 continues to be operated or released from the PLC 12C. Is released, the collision of the inductor 13 of the bar 11 is prevented by returning to the position before the trolley 16 is evacuated, that is, returning to heating heating and starting heating again.

4 is a detailed circuit diagram of the amplifier circuit 12B included in the bar wave detection apparatus 12A according to the present invention, and the amplifier circuit 12B includes a power unit 21, a controller 22, and a power supply abnormality detector 23. ) And a cable disconnection check unit 24.

The power unit 21 of the amplifying circuit 12B is a circuit for obtaining the DC voltages 12V and 24V for the amplifying circuit 12B. A commercial AC voltage 110V is applied to the transformer to provide four diodes and two constant voltages. Obtain the DC voltage (24V, 12V1, 12V2) through the IC.

Since the power unit 21 detects the ground and operates the circuit, the power unit 21 is insulated by a transformer in consideration of the insulation of other equipment. In addition, the DC power supply 12 may be prevented from malfunctioning due to chattering and dropping of the power, which may occur when the relay RY-1 in the control unit 22 of the amplifying circuit 12B operates. The bolts were used separated by 24 bolts.

The control unit 22 of the amplifying circuit 12B uses the DC voltage obtained from the power unit 21. As shown in the figure, since the ruler table 19 for transferring the bar (material) is grounded, the bar on the ruler table is also grounded. At this time, when the bar is in contact with the spring 5 of the ground sensor 1 in progress, the ground current is transmitted through the cable connected inside the bar wave detection device 12A (the transistor of the control unit 22 of the amplification circuit 12B). TR1), and the base potential of the transistor becomes negative (-).

Therefore, the transistor TR1 is turned off and a positive potential is applied to the base of the transistor TR2 through the resistor R5, so that the transistor TR2 is turned on so that the relay RY-1 is turned on. ) Is operated and the wave detection signal is provided to the PLC 12C in accordance with the operation of the relay RY-1.

The power supply abnormality detection unit 23 of the amplification circuit 12B cannot use the wave detection device of the bar when the power supply in the amplification circuit occurs and the circuit does not operate. Therefore, the DC power supply 12 volts (V) and 24 volts ( To detect V) DC12V; This circuit is designed so that PLC 12C can know when any one of 24VDC power supply is abnormal.

12V1 power source that matches DC 12V power supply and DC 24V power supply to 12V is applied to relay RY-2 through diodes D3 and D4. When turned off, the DC 12v2 power is continuously applied through the diode D3, and the power applied to the transistor TR4 through the resistor R10 is turned off, so that the transistor TR4 is turned off, and the resistor R9 and Transistor TR5 is turned on via diode D6.

Therefore, the signal sensed from the ground sensor 1 is safely transmitted to the PLC 12C by operating the relay RY-2. In addition, when the power supply is turned off due to the abnormality of the DC 12V2 power supply, the DC12V1 power supply is continuously applied through the diode D4, and the power supply being applied to the transistor TR3 through the resistor R6 is turned off, so that the transistor TR3 is turned on. It is turned off and transistor TR5 is turned on through resistor R8 and diode D5.

Therefore, the signal sensed from the ground sensor 1 is safely transmitted to the PLC 12C while operating the relay RY-2.

The cable disconnection check unit 24 of the amplification circuit 12B has a distance of about 70m between the control unit 22 and the sensor 1, and the abnormality of the bar wave sensor 1 and the cable disconnection are determined. It is configured to be detected. In the operating state, a ground current always flows to some extent through the resistor R1 in the bar wave detection device 12A, and a negative (-) potential is applied to the base of the transistor TR6.

Since the transistor TR6 is a PNP type transistor, the transistor TR6 is turned on, and is turned on because a positive (+) potential of the transistor TR7 is applied to the base.

As a result, the base potential of the transistor TR8 becomes negative (−), so that the relay RY-3 is always in the off state. At this time, when the cable break occurs, the emitter potential of the transistor TR6 is equal to the base potential, and the transistor TR6 is turned off, and the transistor TR7 is also negative because the base potential is negative. Since the potential is negative (-), the transistor TR7 is turned off, and the transistor TR8 is turned on through the resistor R13, so that the relay RY-3 is turned on to determine whether the cable is disconnected. 12C).

5 is an operation flowchart of the bar wave detection device 12A. The bar wave detector 12A first examines the width, thickness, and temperature data of the bar (material) and sends it to the PLC 12C, which controls all operations of the edge heater, and the heating position of the bogie 16 and the gap of the inductor. And the heating voltage is set up in the calculator in step 31.

After all the data has been set up, a signal to the PLC 12C is sent to the edge heater in step 32. Next, in step 33 it signals that the bar (material) has entered the edge heater.

The bar wave detection sensor then operates to detect the top upward or wave of the bar in step 34. In this case, if the bar top upward or wave is detected in step 34, go to step 35 to check whether the inductor gap-crossing is performed. If the bar top upward or wave is not detected, proceed to step 42 and proceed to the normal edge. Perform a heating operation of the heater.

If the bar top up and wave was detected in step 34, proceed to step 35 to see if the current inductor gap-closed. If gap-closed, there is a risk of collision between the bar and the inductor that proceeds to step 36 where the inductor gap-command is given.

On the other hand, if the inductor is not in the gap-close state, the flow proceeds directly to step 37 to issue an inductor heating stop command. Thereafter, the process proceeds to step 38 to issue a bogie stand position evacuation command so that the bogie is evacuated to the stand-by position.

Then, the process proceeds to step 39, which is a check lock step, and after checking the operation of the wave detection device after the truck arrives in the standby position, if there is no error, the truck moves to the heating position. Wait

Thereafter, the flow advances to step 40 to move the bogie 16 to the heating position so that the bogie checks for the completion of the bogie heating position in step 41 and the inductor gap-closes after the bogie waiting position arrives in step 42. At the same time heating starts, and at step 43 ends.

The effect of the configuration and operation as described above can protect the inductor of the bar edge heater, which is an ever-rolling mill in a hot-rolled steel mill, to prevent damage to the inductor, prevent damage to the insulation, and improve the operation rate of the edge heater. .

Claims (1)

In the edge heater for compensating for the temperature drop of the bar (material) edge portion through the rough rolling process, including an inductor for heating the material by inducing overcurrent inside the object to be heated through the alternating current to the heating coil installed therein, Mounted on the upper inductor 13 of the bar edge heater, the end of the spring is adjusted to the same height as the surface of the upper inductor 13 of the edge heater to the top 17 of the bar 11 after the rough rolling process A ground sensor (1) for detecting a portion where an upward direction is generated or where a wave (18) is generated in the middle portion of the bar (11). Power circuit 21 for providing DC voltages 12V and 24V to the circuit 12B for receiving and amplifying a wave signal sensed by the ground sensor 1 through a cable therein, the ground sensor Connected to (1) and coupled to the control unit 22 and the power unit 21 for receiving the wave detection signal when the bar 11 is in contact with the spring 5 of the ground sensor 1 in progress. The ground sensor 1 is coupled to the power supply fault detection unit 23 and the ground sensor 1 for safely transmitting the wave detection signal even when an abnormality of one of the DC voltage stones of the power unit 21 occurs. And an amplification circuit 12B including a cable disconnection check unit 24 for detecting an abnormality due to cable disconnection, and a signal amplified by the medium width circuit 12B to receive an inductor air cylinder of an edge heater. 15) Gap-opens the inductor with an open command At the same time, a reverse command is given to the trolley 16 to evacuate the trolley to the standby (home) position and then checked whether the ground sensor 1 continues to operate so that the trolley 16 remains in the standby position, or And a PLC (12C) for restoring the bar (11) and the inductor (13) to return to the starting position of heating, bar wave detection device for the edge heater of the finishing rolling apparatus.