JPH0622727B2 - Run-out table on the exit side of hot finishing mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transport table for transporting a hot steel strip or a steel plate by a group of rollers, and particularly to a hot steel strip rolled by a hot finish rolling mill or The present invention relates to a run-out table that sends a steel plate to a winder.

[Conventional technology]

For example, in the run-out table, the rollers are arranged over 100 to 200 m, and cooling water is stripped (rolled steel plate) between the rollers above and below the roller row.
Nozzles for spraying or jetting are arranged in the width direction of the steel strip, and the rolled steel strip rolled by the hot finish rolling mill is cooled and sent to the winder.

In the hot finishing mill that sends out the rolled steel strip, in order to obtain good metallurgical properties of the rolled steel sheet, it is necessary to roll it at a temperature higher than a predetermined value, and as a result, it is sent to the run-out table. The temperature of the rolled steel strip is relatively high. The delivery speed is also relatively high, for example, a high speed of around 10 m / sec. At the run-out table, the rolled steel strip is cooled to a relatively low winding temperature below a predetermined value, reaches a winding machine (coiler), and is wound therein.

Therefore, the conveying speed of the rolled steel strip on the run-out table is a high value of, for example, about 10 m / sec, and the minimum thickness of the rolled steel strip is about 1 mm, so that the so-called stiffness at a relatively thin thickness causes the fly to fly. Wing (a phenomenon in which the tip floats up and rises) or accordion-like waviness is likely to occur.

If the conveying speed of the hot strip is too fast, as shown in Fig. 11 and, if the tip of the hot strip rises once (), the floating amount increases as the strip advances. (), And then it warps (), and the winder winds the steel strip in the folded state, or sometimes it cannot be wound. Therefore, after the tip of the hot-rolled steel strip has passed the final stand of the hot finish rolling mill, until the winding on the winder, and after the rear end of the steel strip has passed the final stand, the tension of the steel strip is almost free. Since it will be in a state, it was unavoidable to reduce the transport speed. Also, when the tension of the steel strip is almost free, the shape of the steel strip will be disturbed by the accordion-like waveform, and if the shape is disturbed, the cooling water and its flow on each part of the steel strip will be uniform. As a result, temperature unevenness occurs and uniform quality cannot be ensured. Further, as the thickness of the steel strip becomes thinner, the tip portion of the strip becomes more likely to float up, which is accompanied by a failure, such as folding or improper winding on a pinch roll, and a decrease in yield.

Such floating of steel strips, especially instability due to floating phenomenon of ultra-thin materials on the run-out table, has been an obstacle to production.

Therefore, in the prior art, firstly, an attempt was made to dispose a linear motor between the rollers (Japanese Patent Publication No. 51-41988), and secondly.
Attempts to dispose electromagnets between rollers (Japanese Patent Publication No.
Third, there is proposed an attempt to dispose an electromagnet roll (Japanese Patent Laid-Open No. 54-77262).

[Problems to be Solved by the Invention]

In either case, since the linear motor and the electromagnet need to apply a strong electromagnetic force to the rolled steel sheet, the rolled steel sheet has a relatively large iron core (magnetic core), resulting in high cost.

In the former two cases, the arrangement of cooling nozzles between most of the rolls of the run-out table becomes complicated or difficult, and the electromagnets placed between the rolls rather than on the transport rolls where the absorption of the steel strip is originally desired. Since it occurs concentratedly on the upper part, only the part of the generated suction force that acts on the transport roll is effective. Due to such a reduction in the efficiency of the suction force and the local concentration force, it is not possible to expect uniformity in the width direction.

In the former third party, there are many failures because a current is passed through the electromagnet in the conveyance roll, which is a rotating body, through a slip ring or a rotary transformer, and there is a problem in terms of maintenance. Furthermore, the former third party (Japanese Patent Laid-Open No. 54-77262)
As shown in FIGS. 8 and 10, the direction of the electromagnet in the magnet roll of the former third party is always the same as the original desired shape, that is, as shown in FIG. 12 of this specification. The uniform force is not generated in the direction of the plate and the width of the plate, but it is the direction of the roll axis of the magnet roll, or the direction changes with the rotation. Furthermore, there are great restrictions in terms of dimensions and environment. .

What is common to all three of the above-mentioned prior arts is that if the iron cores of the linear motor and electromagnet are made small, the electromagnetic force applied to the hot steel strip will be too small to provide sufficient effect. Since the magnetic force is inversely proportional to the power of the gap, once the tip of the hot steel strip rises,
A large lift is applied to the tip of the hot steel strip, increasing the distance (gap) between the hot steel strip and the linear motor or electromagnet.
These magnetic forces can no longer pull down the hot strip.

The present invention has a relatively high suction force to the transport roll of the hot steel strip that is relatively high, and a high concentrated suction force to the axial center of the transport roll of the hot steel strip, An object of the present invention is to provide a run-out table which is relatively evenly distributed in the width direction of the hot strip.

[Means for Solving the Problems]

In the present invention, the magnetic material roller that conveys the hot-rolled steel strip in the Y-direction and extends in the X-direction is shared by the iron core of the electromagnet, and the rolled steel strip is attracted by the magnetic material roller to the magnetic material roller (Z-direction). In order to apply a magnetic force to the magnetic field, an electric coil having one to several tens of coils for each unit of the magnetic roller with one or more of the magnetic rollers as one unit, with the direction Z as the coil central axis. It is intended to solve the above-mentioned problems by rotating the.

A specific means is a plurality of hot-rolled steel strips having a length equal to or greater than the width of the steel strip at predetermined intervals in the transport direction Y and having a rotation axis in a direction X orthogonal to the transport direction Y. Individual magnetic transport rolls; an electric coil that orbits the transport rolls of each unit, with one or more of the transport rolls as one unit, with the direction Z orthogonal to the directions X and Y as the coil center axis. Drive means for rotating the transport roll in the transport direction of the hot-rolled steel strip; and energizing means for supplying a current to the electric coil.

Particularly when the carrier roll is made of a ferromagnetic material, it cannot be said that the driving means is indispensable for the carrier roll. Specifically, a clutch, that is, power transmission, is provided between the carrier roll and the driving means. It is also preferable to use a freely controllable means.

The arrangement of the electric coil is preferably close to the periphery of the transfer roll so as not to cause an obstacle. Specifically, when the main part of the electric coil is located between the transfer rolls, the cooling water injection nozzle is provided. Between the outer peripheral surface of the carrier roll and the plane formed by connecting the central axes of the carrier roll and the lower surface of the hot-rolled steel strip, and arranged at a predetermined distance or more from the cooling water jet nozzle.

Further, the electric coil preferably has at least one circumference around the transport roll of each unit and has an insulating and waterproof structure.

Direct current is desirable for the current flowing through the electric coil, but it is not always necessary to stick to it, and alternating current may be used, and if it is desired to apply a propulsive force in the conveying direction to the steel strip by the magnetic force of the electric coil, a multiphase such as three-phase Let's interact. And, as a preferable form, the body portion of the transport roll is made to have a laminated structure of electromagnetic steel sheets or a steel ring having a width of 50 mm or less with a thin insulating layer.

When the propelling force in the carrying direction is applied to the steel strip by the magnetic force of the electric coil, the driving means for the carrying roll can be omitted. When the electric coil is energized with alternating current, it is appropriate to use the transport roll having the special structure as described above.

[Action]

As described above, the basic configuration of the present invention is
The electric coils of the above-mentioned number of units of the transport rolls (magnetic rollers) are installed on the table in an orbiting manner, and the electric coils can be easily installed in a small space. Installation is very easy. Moreover, since an additional iron core is not required, the implementation cost is extremely low. Since the magnetic roller has a width wider than the entire width of the rolled steel strip, by energizing the electric coil, a strong magnetic force can be uniformly applied to the entire width of the rolled steel strip,
In addition to preventing the rolled steel strip from floating, it has the action of pulling it down even if it slightly floats.

The operation will be described with reference to FIG. 11. As shown in (b) of FIG. 11, even if the leading end of the rolled steel strip is once lifted, when an electric current is passed through the electric coil, a small air gap is generated. Since a large electromagnetic attraction force acts on the rolls of, the flattening from the part with a small air gap gradually progresses as the rolled steel strip progresses, and as shown in Fig. 11 (b),
, And the flattening of the leading edge.

As described above, according to the present invention, in the run-out table on the rear surface of the hot finish rolling mill, as shown in FIG. In addition to pulling back the floating of the steel strip, a large driving force can be applied from the roll to the flattened rolled steel strip, and the tension is almost free before the tip of the steel strip reaches the winder. However, it is possible to exert a tentative force to smooth the progress of the steel strip, stabilize the shape, and further improve the speed of the steel strip. At first glance, it seems that making this original desired shape can be easily done by applying electromagnetic force, and the reality is that there are rather severe restrictions.

Because the transport roll is a rotating body, it is not easy to make good use of it, and in the run-out table, there is a water cooling device with upper and lower nozzles and a roller apron between each roll, and they are It is an essential facility for production and cannot be easily changed. Furthermore, as mentioned above, the run-out table is a place where the steel strip runs around at a high speed of about 10 m / sec, so maintenance is an important evaluation, as in the third party (Japanese Patent Laid-Open No. 54-77262). It is clear that the use of such slip rings is not practical.

The present invention solves a severe problem with the simple structure as described above, and the existing run-out table is used almost as it is, and insulation is prevented for each number of units of the transport roll. The main part of a set of electric coils wound with one to several tens of processed electric wires is arranged in a narrow space in the immediate vicinity of the transfer roll so as not to interfere with the surrounding facilities. is there. By doing so, there is no change in the rotating part, and since the electric equipment is externally attached, it is possible to easily provide a power source capacity corresponding to the required suction force. Speaking dare to say, the point to be changed in the existing equipment is that the roller apron is currently a magnetic body (made of cast iron etc.), so it is desirable to replace it with a non-magnetic material (particularly fine ceramics is preferable).

Now, as shown in FIG. 2c, it is desirable that the position of the electric coil that circulates the transport roll of each unit is closer to the transport roll, because the magnitude of the generated electromagnetic force is larger, but instead, the trouble occurs. It tends to occur, considering the compatibility with the surrounding equipment, etc., between the cooling water injection nozzle and the outer peripheral surface of the transport roll in the horizontal direction, and in the vertical direction, a plane connecting the central axes of the transport rolls. It is good to make it almost parallel to the axial direction of the carrier roll through the area made between the bottom surface of the steel strip and the rolled steel strip, and to separate it from the nozzle by a predetermined distance or more so that it does not directly hit the cooling water from the cooling water jet nozzle. Was found as a result of various examinations.

A main part occupying 50% or more of the cross-sectional area of the electric coil may be arranged in the area.

Next, regarding the winding method of the electric wire of the electric coil, at least one round is made around the transport roll of each unit, and the electric wire has an insulating structure such as an insulating coating, and the cooling water is applied. It is desirable to have a waterproof structure so that it can be used. The electromagnetic force generated from the electric coil is almost proportional to the square product of the number of windings of the electric wire and the value of the electric current flowing through the electric wire. Therefore, these may be determined according to the value of the required attractive force.

The electric current to be passed through the electric coil is desirable because the direct current can generate a large force with a smaller value, but sometimes the three-phase alternating current may be passed as it is, especially the electromagnetic force (moving magnetic field) in the traveling direction of the steel strip.
If you want to expect, you have to interact.

The body of the transfer roll is a magnetic material, and must be a ferromagnetic material such as steel or a paramagnetic material such as chrome stainless steel.

Therefore, a general-purpose transport roll generally used in the run-out table on the exit side of the hot finisher can be used as it is. Furthermore, as a result of investigating a method of improving the generation efficiency of the electromagnetic force by devising this transport roll, it was found that the cause of lowering the efficiency is due to the eddy current generated in the roll body. Therefore, it is best from an efficient point of view that the body portion of the transport roll is formed by punching a disk shape from an electromagnetic steel sheet having an insulating coating and laminating it. However, since this electromagnetic steel sheet roll is too expensive, as a result of various studies on methods that achieve both value and efficiency, a ring was cut into a roll body with a predetermined width in the axial direction of the roll, and a thin insulating layer was formed between the rings. It has been found out that it is desirable to use the transport roll shown in FIG. This is because most of the eddy current can be suppressed, and it has been confirmed experimentally.

It has also been confirmed that the same effect can be obtained by providing a void layer instead of the insulating layer.

The smaller the predetermined width of the ring, the higher the efficiency but the cost. Therefore, from the viewpoint of this efficiency, 50 mm is considered to be the limit, and the lower limit is the thickness of the electrical steel sheet, that is, about 0.2 mm. And, when using the electromagnetic steel roll,
Since the transmission between the transport rolls and the steel plate is increased, the drive device is no longer required and can be omitted.

Therefore, an electric motor, which is a driving device, can be omitted for every other transport roll, or a clutch can be provided between the transport roll and the motor to reduce the moment of inertia so that the rolls are driven only when necessary. Good. Of course, it is possible to take the plunge and omit all motors.

In the aspect in which the electric coil is wound around the transport rolls, since one or more transport rolls are wound as one unit around the roll, the mode in which the electric coils are wound around each transport roll, two adjacent rolls are provided.
There is a mode in which one transport roll is set as one unit and two transport rolls are circulated by one electric coil, one transport roll is set as one unit, and two transport rolls are set as one unit.

As shown in FIG. 2b, the method of passing a current through the electric coil (arrangement of magnetic poles of the generated magnetic field) is such that the upper portion of the carrier roll in contact with the steel strip is alternately distributed to the N pole and the S pole every unit. Is the principle. In principle, the number of electric coils is the minimum number =
Although it is 1, a plurality is required in practice, and industrially,
It is usually 10 or more in consideration of changes in the temperature distribution of the steel strip.

Further, although the cooling water jet nozzle is almost provided between the transfer rolls, it is not necessarily installed or is not installed and used in the intermediate zone, the temperature measurement position and the zone immediately before the winder. Is common. Therefore, most run-out tables have no water injection zone.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 shows a side surface of a run-out table 2 which is a first embodiment of the present invention. The rolled steel strip sent from the hot finish rolling mill 1 is sent to the winder 3 by the run-out table 2 and wound into a coil by the winder 3. In the run-out table 2, the electric coils 20 _{1 to} 20 _n are arranged on the magnetic body rollers 2 ₁ to 2 _n , respectively.

The arrangement of such electrical coil 20 ₁ relative to magnetic roller 2 _1, etc. shown in Figure 2a.

The long side of the electric coil 20 ₁ is the axial direction X of the magnetic roller 2 _1.
It extends, away from the side surface of the roller 2 _1. Short side of the electrical coil 20 ₁ extends parallel to the end faces of the roller 2 _1, apart from the end face. Some of the upper peripheral surface of the roller 2 ₁ protrudes slightly upward from the electrical coil 20 _1.

When energizing the electrical coil 20 _1, the upper peripheral surface of the roller 2 _1, electrical coil 20 ₁ portion protruding slightly above the becomes N pole (or S pole), the side peripheral surface most protruding lower If there is a rolled steel strip above the roller 2 ₁ (S pole, etc.) (N pole), this is the electric coil 20 on the upper peripheral surface of the roller 2 _1.
It is sucked into a portion that protrudes slightly above ₁ . In the case of the present embodiment, as shown in FIG. 2b, the N pole and the S pole are alternately arranged on the upper side of every other transport roll. Electric coils 20 ₂ to 2 for each of the other magnetic material rollers 2 ₂ to 2 _n
The relationship of 0 _{n is} the same as above.

FIG. 2c shows an enlarged view of the arrangement around the transport roll. The diameter of the transport roll is 300 mm, the pitch between the rolls is 420 mm, and there is a cooling water jet nozzle 25 in the center between the rolls. The cooling water is jetted onto the rolled steel strip from below to cool the water at the same time. Is ejected from the roll cooling water header. The electric coil 20 has a cooling water jet nozzle 10 in the horizontal direction.
Make sure that the cooling water does not come into direct contact with it at a distance of 10 mm, and at a position more than 10 mm away from the outer surface of the transport roll 2 and in the vertical direction, below the steel strip and above the line connecting the central axes of the transport rolls. The condition is to place the main part. In this example, the vertical direction is 100 mm above the line connecting the center axes of the transfer rolls, and 10 mm downward, and the horizontal direction is 20 mm to 50 mm below the center between the transfer rolls and 20 mm above the line.
The shape of the upper surface is mm, and a waterproof insulating plate 21 made of stainless steel is provided on the upper surface. Further, the electric coil 20 has a waterproof structure as a whole with a waterproof coating 22, and the insulating structure corresponds to a structure in which each electric wire is covered. With the above arrangement, the electric coil could be arranged with almost no modification of the existing carrier roll equipment.

Based on the arrangement of FIG. 2c, the run-out table of the present invention was designed as follows. Targeting a steel strip of 1.2 mm, which is the minimum thickness for transporting the run-out table, we took a high-speed video of the lifting phenomenon of the steel strip and analyzed the behavior. It was found that the spacing was less than 100 mm, and the estimated lift due to air resistance was less than 30 kg / m ² .

Therefore, as the most severe conditions, Fig. 13 shows the results of studying various design conditions for generating an absorbing force due to an electromagnetic force of 30 kg / m ² when the air gap is 100 mm by nonlinear FEM calculation. Calculation conditions are electric coil cross section 2620mm
² , current capacity 20 kw / roll, coil current = DC, coil space factor = 1.

From FIG. 13, it was found that the coil current density should be 4 A / mm ² or less in order to satisfy the above design conditions.
Therefore, the normal current coil may be within the range of the conventional product, and the normal current coil is about 2 A / mm ² , and a maximum current of 4 A / mm ² may be applied.

The electric coil is placed on 20 continuous transfer rolls, and the rising current of the electric coil is increased from zero to the maximum rated value while the rising condition of the steel strip is filmed by a high-speed video (VTR). , Evaluated, run out
It was confirmed that the accordion state of the steel strip disappeared as the applied current increased at the coil installation position on the table.

Referring again to FIG. ₁ , each of the magnetic material rollers 2 ₁ to 2 _n causes the rolled steel strip to be directed from the rolling mill 1 to the winder 3 (clockwise direction) by each of the electric motors 30 ₁ to 30 _n. Drive to rotate. In this embodiment, when the rolling controller 40 is engaged with the end of the rolled steel strip,
A lock-on pulse P ₀ is generated in response to an increase in the detection signal level of the load cell 1 _s for rolling load detection, and
One rotation pulse P _s is generated for each rotation of the work roll by a predetermined small angle. The motor controller 50 calculates the rolling speed from the synchronous pulse Ps, and rotationally energizes the motors 20 _{1 to} 20 _n at a speed (peripheral speed) slightly higher than the rolling speed.

The electric coil controller 70 controls the lock-on pulse P _0.
The periodic pulse Ps is counted from the
The electric conduction start timing and the electric conduction end timing of each of 0 _{1 to} 20 _n are calculated, and the electric coils 20 _{1 to} 20 _n are calculated.
Control each energization.

The winder controller 60 counts the synchronization pulse Ps based on the lock-on pulse P ₀ , calculates the arrival timing of the leading end of the rolled steel strip, and controls the winding of the incoming rolled steel strip.

FIG. 3 shows the configuration of the electric coil controller 70.
To explain this, the DC output ends of the coil power supply circuit 72S for rectifying the single-phase alternating current to direct current, electrical coil 20 ₁ to 20
_A switch circuit 71 (switch circuits 1 to n) is interposed between each of the _n , and these switch circuits turn on the electric coil when an ON instruction signal (high level 1) arrives. Connected to the DC output terminal.

The winding direction of each of the electric coils 20 _{1 to} 20 _n and the energization direction of each of the switches 71 are set so that adjacent magnetic rollers generate magnetic fluxes of opposite polarities, as shown in FIG. 2b. There is. This is, electrical coil ₂₀ 1 to
This is to limit the range of the magnetic field generated by 20 _n to the very vicinity of the table 2. If, the magnetic roller ₂ 1 to
_If all 2 _n are set to have the same polarity, the whole of the rollers 2 ₁ to 2 _n constitutes one core (only one pole),
This is because the magnetic field due to these extends to a range far away from the table 2, and the influence of the magnetic field on other devices becomes large.

The latch circuit 73 gives an energization instruction signal (high level 1) to each of the switch circuits 1 to n of the switch circuit 71. Each latch of the latch circuit 73 is set by the output pulse (high level 1) of each gate element of the AND gate circuit 74 and outputs the energization instruction signal (S _{1 to} S _n = 1), and each of the AND gate circuit 75 outputs. It is reset by the output pulse (high level 1) of the gate element to erase the energization instruction signal (outputs low level 0).

To the AND gate circuit 75, a decoder 76 gives an electric coil (gate element) selection signal, and a microprocessor (hereinafter referred to as CPU) 78 gives a set pulse (energization instruction signal) Ss. In the AND gate circuit 74,
Decoder 77 gives an electric coil selection signal, and CPU
Reference numeral 78 gives a reset pulse (non-energization instruction signal) Rs. These decoders 76 and 77 have a CPU 78.
Gives the electric coil selection signal (i).

For example, CPU 78 specifies a electrical coil 20 _1,
When the code indicating the numeral 1 is given to the decoder 76 and the set pulse Ss is output, the gate element 1 of the AND gate circuit 74 outputs one pulse, the first latch of the latch circuit 73 is set, and the energization signal ( S ₁ = 1) is output,
The first switch circuit 71 (switch circuit 1) is turned on to energize the electric coil 20 ₁ . Accordingly, the magnetic flux shown in FIG. 2b (dashed line) flows through the magnetic roller 2 _1, are temporarily attracted to the roller 2 ₁ of the roller 2 ₁ if there is a rolled steel strip nearby. CPU78 is the electric coil 2
When the decoder 77 is supplied with a code indicating the numeral 1 designating 0 ₁ and the reset pulse R _s is output, the gate element 1 of the AND gate circuit 75 outputs one pulse, and the first latch of the latch circuit 73 is output. Is reset to output a de-energization signal (S ₁ = 0), the first switch circuit 71 (switch circuit 1) is turned off, and the electric coil 20 ₁ is turned off.
There will be de-energized, the magnetic roller 2 ₁ becomes de-energized.

The lock-on pulse P is applied to the input port St of the CPU 78.
₀ is applied, and the synchronizing pulse Ps is applied to the interrupt input port INTs. The CPU 78 uses the lock-on pulse P
_The synchronization pulse Ps is counted from ₀ as a base point, and in this embodiment, the electric coils 20 ₁ to 20 _1- at the timing shown in FIG.
20 _n controls energization / de-energization (1/0 of signals S _{1 to} S _n ). In addition, in FIG. 5, the distance data L _{1 to} L _n are
The count value of the synchronization pulse Ps corresponding to the distance (L ₁ ) between the rolling mill 1 and the roller 20 ₁ and the distance between other rollers (L _{2 to} L _n ), which is written in the internal ROM of the CPU 78. Is.

The control operation of the CPU 78 is shown in FIG. 4a. When power is supplied (step 1: the word step is omitted hereinafter in parentheses), the CPU 78 sets the input / output port to the signal level in the standby state, the internal register, the counter,
Clear the timer etc. and set the data in the standby state (2). Then, the interruption is permitted (3). With this permission, the CPU 78 thereafter executes the interrupt processing shown in FIG. 4b every time when one pulse of the synchronization pulse Ps arrives.

Explaining the interrupt processing shown in FIG. 4b, the synchronization pulse Ps
When the time comes, the CPU 78 proceeds to the interrupt INTs (20), updates the content of the register PCR to a value indicating one larger value (21), and returns to the main routine (Fig. 4a).
By this interrupt processing, the synchronization pulse Ps is counted,
The count value is written in the register PCR.

Referring again to FIG. 4a, the control operation of the CPU 78 will be described.

(1) Timing monitoring: When the lock-on pulse P ₀ arrives, the CPU 78 indicates that the content i of the data read address register i (which is set to 0 at the initialization of step 2) is incremented by 1 (i. = 1) is updated (4,5) and the register PCR is cleared (6). As a result, the count (register PCR) of the synchronization pulse Ps by the interrupt INTs (20) is initialized (counted up from 0).

That is, the count for determining the timing of energizing / de-energizing the electric coil is started when the lock-on pulse P ₀ arrives.

After that, set the count value (contents of the register PCR) to data L
₁ (i = 1) (8, 9), when the count value becomes L ₁ , the content i (i =
1) is updated to a value indicating one larger number (i = 2) (4,5), and the register PCR is cleared (6). Similarly, when the count value PCR becomes the data Li, i is updated by 1 and the register PCR is cleared.

When i reaches n + 1 (the tip of the rolled steel strip reaches the winder 2), i is cleared (14, 5, 6, 7, 1
6) Wait until the lock-on pulse P ₀ arrives again (4). Incidentally, when the count value PCR reaches data Li is a switching timing of the energization / non-energization of electrical coil ₂₀ 1 to 20 _n.

(2) electrical coil ₂₀ 1 to 20 _n of the energization / non-energization control: PCR = _L becomes ₁ (tip of the rolled steel strip came on roller _{2 1)} times, data indicating the i (= 1) The set pulse Ss is output to the decoder 76 (11). As a result, the first gate element 1 of the AND gate circuit 74 outputs the set pulse Ss, and the first gate element 1 of the latch circuit 73
The second latch outputs S ₁ = 1 and the first switch circuit 1 of the switch circuit 71 is turned on, and the electric coil 20
₁ is energized. As a result, the roller 20 ₁ generates a magnetic flux and the rolled steel strip is attracted to the roller 20 ₁ . Then i +
The data indicating 1 (= 2) is given to the decoder 76 and the set pulse Ss is output (12). As a result, the second gate element 2 of the AND gate circuit 74 causes the set pulse S
s is output, and the second latch of the latch circuit 73 is S ₂ =
Outputs 1, the switch circuit 2 of the No. 2 switch circuit 71 is turned on, an electric coil 20 ₂ is also energized. Thus the roller 20 ₂ is also rolled steel strip to generate a magnetic flux is also attracted to the roller 20 _2.

When it becomes PCR = _{L 2;} A (i = 2 when the leading end of the rolled steel strip came on roller _{2 2), i-1 (} = 1) the data indicating given to the decoder 77 reset pulse Rs Is output (13). As a result, the first gate element 1 of the AND gate circuit 75 outputs the reset pulse Rs,
The first latch S ₁ = 0 of the latch circuit 73 is output, the first switch circuit 1 of the switch circuit 71 is turned off, and the energization of the electric coil 20 ₁ is cut off. Thus the suction force by the roller 20 ₁ disappears.

Then, the data showing i + 1 (= 3) is given to the decoder 76, and the set pulse Ss is output (15). As a result, the third gate element 3 of the AND gate circuit 74 outputs the set pulse Ss, the third latch of the latch circuit 73 outputs S ₃ = 1, and the third switch of the switch circuit 71 is output. circuit 3 is turned on, an electric coil 20 ₃ is energized. As a result, the roller 20 ₃ also generates a magnetic flux, and the rolled steel strip is attracted to the rollers 20 ₂ and 20 ₃ .

Similarly, every time PCR = Li is reached (the tip of the rolled steel strip reaches the roller 2i on the downstream side to which electricity is applied first), the tip of the rolled steel strip revolves around the roller 2i _-1 which has already passed. The electric coil 20i _-1 is de-energized, and the electric coil 20i ₊₁ that circulates around the roller 2i ₊₁ on the downstream side of the tip of the rolled steel strip is energized.

(In i = n + 1, the leading end reaches the winder 3 in the rolled steel strip) become PCR = L _{n +1} and, since the electrical coil being energized at that time is only 20 _n, the electrical coil 20 _n De-energize (13, 14) and clear i (5, 6, 7,
16) Next, wait for the lock-on pulse P ₀ to arrive (4).

By the control operation of the CPU 78 described above, the electric coils 20 _{1 to} 20 _n are energized so as to sequentially attract the tips to the rollers 2 ₁ to 2 _n in synchronization with the progress of the tips of the rolled steel strip, When the tip passes, it is de-energized (S
₁ ~S _n = _1/0: reference Figure 5). In this way, only by applying a magnetic attraction force to the tip of the rolled steel strip, the tip is lifted (this is the cause of flying and accordion-like waviness).
Is prevented, and the rolled steel strip does not cause frying or accordion-like waviness.

Since the magnetic attraction force of the above-described aspect acts on the rolled steel strip as a braking force, it is preferable that the magnetic attraction force is as small as possible, but if it is too small, lift-up occurs. Therefore, in the above-described first embodiment, as described above, the magnetic attraction force is applied only to the tip end portion of the rolled steel strip,
The lifting force is prevented and the braking force over the entire rolled steel strip is small.

As mentioned above, in the above-described first embodiment, the roller 2 ₁
Since the winding direction and the energization direction of the electric coil are set so that the magnetic pole polarities alternate between ~ 2 _n in the order of their arrangement, the magnetic field connects the table surface (the apex of the upper peripheral surface of the roller). Line: It extends only to the range very close to the moving surface of the rolled steel strip. Therefore, if the floating of the rolled steel strip becomes large, the suction force acting on it will decrease geometrically. On the other hand, _if all the rollers 2 _{1 to} 2 _n are magnetized to have the same polarity, the entire magnetic field of the rollers 2 ₁ to 2 _n becomes one pole, and the magnetic field extends far in the Z direction perpendicular to the table surface. Also, this causes a magnetic field to reach far in the moving direction Y of the rolled steel strip, and exerts a relatively strong pulling down force even on a steel strip that has risen relatively high, which is effective in returning to the uplift. The magnetic field may adversely affect other devices magnetically.

By the way, if the rising of the tip of the rolled steel strip occurs at a position close to the hot finish rolling mill 1, large frying and accordion-like corrugation are likely to occur, and these adverse effects are great. If floating occurs near the winding machine 3, the leading end of the rolled steel strip may be caught by the winding machine 3 before the frying or accordion-like waviness occurs, or before they are small, which is a harmful effect. Is small.

Therefore, in the second embodiment of the present invention, as shown in FIG.
The site near the rolling mill 1, the three rollers as a unit, placed one electrical coil 20 ₁ to 20 ₄ per one unit per one unit two rollers as a unit in the middle part The electric coils 20 _{5 to} 20 ₁₀ of No. 1 were installed, and one roller was set as one unit, and one electric coil 20 _{1 to} 20 _n was installed per unit in a portion close to the winder 3.

Timings of energization / de-energization of these electric coils 20 _{1 to} 20 _n are shown by S _{1 to} S _n in FIG. The hardware configuration of the electric coil controller (70) of the second embodiment is the same as that shown in FIG. 3, but the contents of the timing data L _{1 to} L _n are different from those of the first embodiment. It's different.

According to the second embodiment, the roller 2 ₁ to 2 _13, since three adjacent is the same magnetic poles at the same time, because their magnetic flux extends farther (higher) in the Z direction, when high the raised Also pull the rolled steel strip down onto the rollers. Roller 2 _14-
Two of the two adjacent magnetic poles 2 and ₂₄ simultaneously have the same magnetic pole, and even when the floating height is relatively high, the rolled steel strip is pulled down onto the roller. Roller 2 ₂₅ to 2 _n are those adjacent each other since the different magnetic poles to prevent the roller's rolling steel strip from rising. In this way, it is possible to more effectively prevent the rolling and waving of the rolled steel strip in a form in which the influence of a magnetic field far away is avoided as much as possible.

It should be noted that the rollers 2 _{1 to} 21 ₁₃ are provided with one electric coil for every three rollers, but one electric coil is provided for each roller as in the first embodiment, and three adjacent electric coils are provided. The magnetic field generation directions of the three rollers by the electric coil may be set to have the same polarity. Similarly, the roller _{21 14-2 24,} one roller per may be provided one electric coil.

FIG. 7a shows a third embodiment of the present invention. In this third embodiment, the rollers 2 ₁ to 2 _n are used as iron cores of a linear motor to convey and drive the rolled steel strip with a moving magnetic field, and an electric motor for driving rollers (30 ₁ to 30 _n ) is used. Is omitted. That roller ₂ 1 to 20 _n is an idle roller.

In the third embodiment, an electric coil 2 for passing a U-phase current so as to convey a rolled steel strip by a moving magnetic field by a three-phase alternating current.
0 ₁ , 20 ₄ , 20 ₇ , ... Are rollers (2
_{1 to} 2 ₃ ), (2 ₄ to 2 ₆ ), (2 ₇ to 2 ₉ ), ...
The electric coils 20 ₂ , 20 ₅ ,
20 ₈ , ... Are rollers (2 ₂ to 2 ₄ ),
(2 _{5 to} 2 ₇ ), (2 ₈ to 2 ₁₀ ), ...
Electric coils 20 ₃ , 20 ₆ , 20 ₉ , for passing W-phase current
... each roller _{(2 3-2} 5), ₍₂ 6 ~
2 ₈ ), (2 ₉ to 2 ₁₁ ), ...
Each electric coil is installed.

Electric coils 20 ₁ (20i ₊₃ ), 20 ₂ (20i ₊₄ ) and 20 ₃ (20i ₊₅ ; i = 1, 2, 3, ...)
Is one unit for generating a moving magnetic field, and each of these electric coils is a switch circuit 1 ₁ [(1+
i) ₁ ], 1 ₂ [(1 + i) ₂ ], and 1 ₃ [(1+
i) ₃ ], the U-phase output terminal of the three-phase power supply circuit 72M,
It is connected to the V-phase output terminal and the W-phase output terminal. These switch circuits ₁ 1 to 1 ₃ are turned off when the _{S 1} signal _{S 1} is turned on when the 1 is zero. Switch circuit ₍₂ 1 -
2 ₃ ) to (9 _{1 to} 9 ₃ ) are turned on when the signals S _{2 to} S ₉ are 1 and turned off when they are 0.

The hardware configuration of the electric coil controller (70) of the third embodiment is similar to that of the first embodiment shown in FIG. 3, except that the contents of the timing data L _{1 to} L _n and the electric coil are The timing for turning off the power is different from that in the first embodiment. Furthermore, in the third embodiment, the microprocessor 78 has a lock-on pulse P
₀ s and a stripping pulse P ₀ e (a pulse indicating that the tail end of the rolled steel strip has passed through the rolling mill and thus the signal level of the load cell (1 s) has decreased) are given from the rolling controller (40). , The microprocessor (78) responds to the lock-on pulse P ₀ s with signals S ₁ -S as shown in FIG. 7b.
₉ are sequentially set to 1, and the signals S _{1 to} S ₉ are sequentially set to 0 in response to the plate omission pulse P ₀ e.

That is, when the tip of the rolled steel strip is written meshes in hot finish rolling mill _{(1) (P 0 s)} , the switch 1 ₁ to 1 ₃ ON (S
₁ = 1) and the first set of electric coils 20 _{1 to} 20
_{At 3} , a moving magnetic field is generated from the rollers 20 ₁ to 20 ₃ . The tip of the rolled steel strip, and when arriving at the roller 20 ₁ near the suction force to the roller 2 ₁ by the moving magnetic field, the winder 3
Receives the conveyance force toward. When rolled steel strip rides roller 2 ₁ roller 2 ₁ is rotationally driven at the rolling steel strip (idles). That roller 2 ₁ supports a rolled steel strip, are not transported drives the rolled steel strip.

When the leading end of the rolled steel strip reaches the rollers 20 ₂ and further turns on the switch ₂ 1 to 2 _3, further second set of electrical coils ₂₀ 4-20 _6, a moving magnetic field directed from the roller _{2 4} to _{2 6} Occur. The rolled steel strip is composed of rollers 2 ₁ to 2 ₃ and 2
The moving magnetic fields of ₄ to ₂₆ receive the attraction force to the rollers 2 ₁ to 2 ₄ and the conveying force toward the winder 3. The rollers 2 ₁ to 2 ₃ on which the rolled steel strip is mounted are rotationally driven by the rolled steel strip.

When the leading end of the rolled steel strip reaches the roller 20 _5, further turns on the switch ₃ 1 to 3 _3, further in the third set of electrical coils ₂₀ 7-20 _9, a moving magnetic field directed from the roller _{2 7 2 9} Occur. The rolled steel strip is composed of rollers 2 ₁ to 2 ₆ and 2
The traveling magnetic field of _{7-2 9} receives a suction force to the roller ₂ 1 to 2 _6, the conveying force toward the winder 3. Roller 2 ₁ to 2 of rolled steel strip rode ₅ is rotated in the rolling steel strip.

Similarly, as the tip of the rolled steel strip progresses,
, 4th group, ... Switches 4 ₁ to 4 ₃ and 5 ₁ to
5 _3, turn on ..., fourth set, fifth set, ... of the electric coil _{20 10-20 12,} 20 _{13-20 15,}
, To generate a moving magnetic field. The rolled steel strip receives a suction force to the roller and a conveying force to the winder 3 due to the moving magnetic field of the roller. The roller on which the rolled steel strip is mounted is rotationally driven by the rolled steel strip.

As described above, while the rolled steel strip is on all the rollers 2 ₁ to 2 _n , a three-phase alternating current is applied to all electric coils, and the rolled steel strip on the table moves toward the winder. Is applied to the rolled steel strip toward the winder, and the rolled steel strip is attracted to each of the rollers.

When the tail end of the rolled steel strip passes through the hot finish rolling mill 1, the rolling controller (40) generates a stripping pulse P ₀ e, and in response to this, the microprocessor (78) causes the timing shown in FIG. 7b. Then, the signals S _{1 to} S ₉ are returned to 0. That is, the energization is stopped from the coil group (adjacent three groups) where the tail ends have arrived.

According to the third embodiment, the electric coil is shared by the steel strip conveying means, and the roller driving electric motors (30 ₁ to 30 _n ) are omitted.

FIG. 8a shows a fourth embodiment of the present invention. In the fourth embodiment, the first half of the table is constructed similarly to the second embodiment shown in FIG. 6, and the second half of the table is configured to generate a three-phase magnetic field (similar to the third embodiment, but the roller An electric motor for driving is provided, and driving by a moving magnetic field is performed only at the tip of the rolled steel strip). In FIG. 8b, the switch circuit 1
To 4, shows the generation timing of the signal _S 1 to S ₉ for turning on / off each of the ₍₅ 1 to 5 ₃₎ to ₍₉ 1 to 9 _3).

In the fourth embodiment, similarly to the second embodiment, the electric coils are sequentially turned on and the electric coil passing the leading end is turned off in synchronization with the progress of the rolled steel strip. ,
In the latter half of the table, since the electric coil generates a moving magnetic field, a relatively large conveying force is applied to the tip of the rolled steel strip in addition to the suction force to the roller, and the tip moves to the winder 3. Is smoother, and the effect of preventing the rolled steel strip from rising is further enhanced.

The coil power supply circuit 72S (first, second and fourth embodiments) may be an AC power supply instead of the DC power supply. That is, the electric coil may be AC energized.

As described above, the coil power supply circuit 7 that rectifies alternating current into direct current
When a 2S direct current is applied to the electric coil, the magnetic flux changes in the Z direction at the time of switching from non-energized to energized and at the time of switching from energized to non-energized. In the case of generating a swirling eddy current and energizing the alternating current (the third embodiment shown in FIG. 7a and the eighth embodiment
The latter half of the table of the fourth embodiment shown in the figure is also AC-energized). In response to increase / decrease in magnetic flux due to current increase / decrease while the switch circuit is on, the roller is Generates an eddy current that swirls around a direction. Eddy currents increase the temperature of the rollers and reduce the power input efficiency. In the case of DC energization, the generation of eddy current causes the switching circuit to turn on / off.
Since it is only when switching off, there is no particular effect, but in the case of AC energization, the eddy current is generated continuously because the current level changes continuously, and the effect is large.

Therefore, in a preferred embodiment of the present invention, in order to improve eddy current loss (rise of roller temperature, decrease of power efficiency), the roller is provided with insulating films on the front and back surfaces which have good magnetic characteristics and suppress the generation of eddy current. The formed laminated body of thin electromagnetic steel sheets, that is, a laminated roller is used.

FIG. 9 shows a vertical cross section of an example thereof. In FIG. 9, ring-shaped thin electromagnetic steel plates are pressure-bonded in the thickness direction thereof to the inner wall and both ends of an electromagnetic steel plate cylinder 201 integrated into a thick-walled cylinder,
A resin cylinder 202 with a flange is formed by resin molding, and the hollow roller cylinder (201 + 202) is integrally formed. The shaft body 204 to which the first end plate 204 is fixed is passed through the inner space of the hollow roller cylinder (201 + 202), and the quadrangular tip 203t of the shaft body 204 is located outside the hollow roller cylinder (201 + 202). And protrudes into the square receiving hole of the second end plate 205 with a shaft. First end plate 2
04 and the second end plate 205 are fixed to the flanged resin cylinder 202 of the hollow roller cylinder (201 + 202) with bolts, whereby the hollow roller (201 + 202), the first roller
The end plate 204, the second end plate 205, and the shaft body 203 are integrated to form one laminated roller 2p.

In this laminated roller 2p, the shaft body 203 is a magnetic body, but the magnetic flux passes through the electromagnetic steel plate cylinder 201 surrounding the shaft body 203, and the magnetic flux passing through the shaft body 203 is small. That is, the shaft body 2
Reference numeral 03 is a magnetic steel plate cylinder 201 that is magnetically shielded. Therefore, the eddy current generated in the shaft body 203 is small, and the eddy current loss there is small. In the electromagnetic steel plate cylinder 201, an eddy current that swirls around the Z direction tends to be generated, but since the current cannot flow due to the insulating film between the thin electromagnetic steel plates, the eddy current is a pole in the range of the thickness of each thin electromagnetic steel plate. The current loss is very low and the eddy current loss is extremely small.

Therefore, it is preferable to use a lamination roll 2 _p as roller ₂ 1 to 2 _n, roller ₂ 1 to 2, particularly shown in 7a Figure
_n and, like Figure 8a are shown roller 2 ₁₃ to 2 _n, the electrical coil for energizing AC is preferred to use the installed roller laminating roller 2p. Further, it is preferable to use the laminating roller 2p also for the roller provided with the electric coil for energizing the direct current, if necessary.

〔The invention's effect〕

As described above, in the present invention, the magnetic roller (2 ₁ to 2 _n ) that conveys the hot rolled steel strip (hereinafter, rolled steel strip) in the Y direction and extends in the X direction is shared by the iron core of the electromagnet, and the magnetic material is used. Laura (2
To exert a magnetic force to the rolled steel strip in a direction (Z direction) adsorbed to ₁ to 2 _n) by magnetic roller (2 ₁ to 2 _n), the direction Z as the coil center axis, magnetic roller (2 ₁ ~ 2 _n ) of 1
Since one or more electric coils (20 ₁ , 20 ₂ , 20 ₃ , ...) Are circulated around the magnetic roller of each unit as one unit,
Since the magnetic roller (2 _{1 to} 2 _n ) has a width wider than the entire width of the rolled steel strip, a strong magnetic force can be applied to the rolled steel strip, which prevents the floating of the rolled steel strip from occurring. Pull it down even if it floats a little. Therefore, frying of the rolled steel strip and accordion-like waviness are sufficiently prevented.

On the other hand, on the transport table (hereinafter, run-out table, for example), the number of electric coils (20 ₁ , 20 ₂ , 20 ₃ , ...) Of the magnetic cola (2 ₁ to 2 _n ) is equal to the number of the units. Only the electric coil (20 ₁ , 20 ₂ , 20 ₃ , ...) can be easily installed in a small space. For example, the cooling nozzle rack can be left as it is, or the nozzle rack can be installed. It's easy. Since no separate iron core is required, the implementation cost is extremely low.

[Brief description of drawings]

FIG. 1 is a side view of the first embodiment of the present invention. FIG. 2a is an enlarged perspective view of the rollers 2 ₁ to ₂₅ shown in FIG. FIG. 2b is an enlarged side view showing the end faces of the rollers 2 ₁ to ₂₅ shown in FIG. FIG. 2c is an enlarged view showing the arrangement near the transport roller. FIG. 3 is a block diagram showing a configuration of the electric coil controller 70 shown in FIG. 4a and 4b are flowcharts showing the control operation of the microprocessor 78 shown in FIG. Figure 5 is provided by the control operation of the microprocessor 78 is a time chart showing the energization / non-energization timing of the electrical coil 20 ₁ to 20 _n shown in Figure 1. 6 is a side view showing the energization / non-energization timing of the electrical coil 20 ₁ to 20 ₁₆ showing main part schematic and the bottom of the second embodiment of the present invention. FIG. 7a is a plan view showing the outline of the main part of the third embodiment of the present invention. FIG. 7b shows the electric coils 20 _{1 to} 20 _{n-2 of} the third embodiment.
It is a time chart showing the energization / de-energization timing of. FIG. 8a is a plan view showing the outline of the main part of the fourth embodiment of the present invention. FIG. 8b shows the electric coils 20 _{1 to} 20 _{n-2 of} the fourth embodiment.
It is a time chart showing the energization / de-energization timing of. FIG. 9 is a vertical sectional view of the laminating roller 2p. FIG. 10 is a cross-sectional view of a carrier roll in which a steel ring having a width of 50 mm or less is laminated on a body part with a laminated structure with a thin insulating layer or a void layer. FIG. 11 is a diagram showing the state of the leading end of a thin steel strip moving on a transport roll. (A) shows a case where a conventional electromagnetic force does not act in a time series order of ,,, and (b). Is the time series when the electromagnetic force of the present invention acts ,,,
It is a figure expressed in order of. FIG. 12 is a conceptual diagram of a run-out table in which the magnitude of the electromagnetic attraction force is added to the equipment in which the electric coil is circulated for each transport roll. FIG. 13 is a graph showing the relationship between the distance between the transport roll around the electric coil and the rolled steel strip, and the electromagnetic attraction force on the rolled steel strip. 1: Hot finish rolling mill 2: Run-out table (conveyance table) 2 ₁ to 2 _n , 2 _p : Magnetic roller (magnetic roller) 20 _{1 to} 20 _n : Electric coil (electric coil) 3: Winding Take-up machine, 30 ₁ to 30 _n : Electric motor (driving means) 40: Rolling controller, 50: Motor controller 60: Winding machine controller, 70: Electric coil controller 71: Switch circuit (energizing means), 72S: DC power supply circuit 72M: 3-phase AC power supply circuit, 73: Latch circuit 74,75: AND gate circuit, 76,77: Decoder 78: Microprocessor

Claims (9)

[Claims] 1. A plurality of hot-rolled steel strips arranged at a predetermined interval in the transport direction Y with a length equal to or greater than the width of the steel strip, and having a rotation axis in a direction X orthogonal to the transport direction Y. A magnetic material-conveying roll; an electric coil that orbits the conveying roll of each unit, with one or more of the conveying rolls as one unit, with a direction Z orthogonal to the directions X and Y as a coil central axis; A run-out table on the delivery side of the hot finish rolling mill, comprising: a drive unit that rotationally drives the transport roll in the transport direction of the rolled steel strip; and an energization unit that applies a current to the electric coil. 2. The run on the delivery side of the hot finish rolling mill according to claim 1, wherein the transport roll is connected to a drive means for rotationally driving it via a clutch.・ Out table. 3. A plurality of hot-rolled steel strips arranged at a predetermined interval in the transport direction Y with a length equal to or greater than the width of the steel strip, and having a rotation axis in a direction X orthogonal to the transport direction Y. A ferromagnetic transport roll; cooling water jet nozzles arranged in the X direction between the transport rolls; one or more of the transport rolls with a direction Z orthogonal to the directions X and Y as a coil central axis. The run-out table on the delivery side of the hot finish rolling mill, comprising: a plurality of electric coils, each of which goes around each of the transport rolls; 4. The cooling water is provided between the transfer rolls and the main part of the electric coil according to any one of claims (1), (2) and (3). In a region formed between the jet nozzle and the outer peripheral surface of the transport roll and between the plane connecting the central axes of the transport rolls and the lower surface of the hot-rolled steel strip, the cooling water jet nozzle and the cooling water jet nozzle are arranged at a predetermined distance or more. Run-out of the hot rolling mill outlet side characterized by
table. 5. A hot finish rolling mill, characterized in that the electric coil according to claim (4) has at least one round of a conveying roll of each unit and has an insulating and waterproof structure. Run-out table on the side. 6. The energizing means causes a direct current to flow through the electric coil, and the energizing means provides the electric coil with a direct current.
The run-out table on the delivery side of the hot finish rolling mill according to any one of the paragraphs (3), (4), and (5). 7. An energizing means causes an alternating current to flow through the electric coil, and the energizing means is characterized in that (1) and (2).
The run-out table on the delivery side of the hot finish rolling mill according to any one of the paragraphs (3), (4), and (5). 8. The invention according to claim 1, wherein the body portion of the transport roll has a laminated structure of electromagnetic steel plates.
The run-out table on the delivery side of the hot finish rolling mill according to any one of (1), (2), (3), (4) and (5). 9. The structure according to claim 1, wherein the body portion of the transport roll has a structure in which steel rings having a width of 50 mm or less are laminated via a thin insulating layer or a void layer. (2)
The run-out table on the delivery side of the hot finish rolling mill according to any one of the items (3) and (3).