JP2006341275A - Rolling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire rolling apparatus which can shorten a waiting time from the passing of the tail end of a wire material in rolling to the supply of the leading end of the next wire material, and can achieve a high operation rate. <P>SOLUTION: When the passing of the tail end of the wire material 12 has been judged by means of a tail end passing judgement means (a drive control means QH8), the drive control means QH8 makes a drive control circuit DH8 stop the supply of a driving current to an electric motor MH8 for driving rolling rolls RH8a, RH8b of a rolling stand SH8 of a first intermediate line 14, and at the same time, the electromagnetic brake is applied to the electric motor MH8 by operating the electromagnetic brake circuit 46 of the drive control circuit DH8. As a result, the rotational speed of the electric motor MH8 is furthermore quickly slowed down compared with natural slowdown. Therefore, in the rolling rolls RH8a, RH8b, the waiting time from the passing of the tail end of the wire material 12 in rolling to the supply of the leading end of the next wire material 12 can be shorten, and the operation rate of the wire rolling apparatus 10 can be increased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling apparatus in which a plurality of pairs of rolling rolls are arranged in series, and more particularly to a technique for shortening the input interval of a material to be rolled that is intermittently supplied to a leading rolling roll.

A plurality of pairs of rolling rolls arranged in series, and a drive control circuit for controlling a drive current of an electric motor that rotationally drives the plurality of pairs of rolling rolls. 2. Description of the Related Art A rolling device of a type that forms a loop of a material to be rolled between predetermined pairs of rolling rolls in the process of rolling the rolled material is known. For example, the rolling apparatus described in patent document 1 or patent document 2 is it.
JP-A-6-277730 JP-A-11-5839

  The rolling apparatus as described above is characterized in that since a loop is formed between predetermined rolling rolls, a good product with high dimensional accuracy can be obtained without being affected by tension or compression force.

  In general, in the rolling apparatus described above, an electric motor that rotationally drives a rolling roll located at the most upstream part among a plurality of pairs of rolling rolls arranged in series is supplied with a driving current at the same time as the end of the material to be rolled passes during rolling. Is stopped, and the rotational speed of the electric motor is reduced by natural deceleration. When the rotational speed of the electric motor is reduced to a preset standby rotational speed, the tip of the next material to be rolled is supplied and rolling is started again.

  By the way, in the above conventional rolling apparatus, the supply of the drive current is stopped at the same time as the end of the material being rolled passes, and the rotation speed of the motor of the rolling roller is started to decrease due to the natural deceleration. For example, it takes about ten and a few seconds until the rotation speed of the electric motor is reduced to the preset standby rotation speed, and the non-rolling time until the supply of the leading end of the next material to be rolled is increased. It was one of the obstacles to increase the operating rate of rolling equipment. The reduction time of the rotation speed of the electric motor is considered to be caused by a large rotational inertial force between the rolling roller and the electric motor connected thereto via a speed reducer.

  The present invention has been made against the background of the above circumstances, and its purpose is to wait until the end of the next rolled material passes after the end of the rolled material being rolled passes. An object of the present invention is to provide a rolling apparatus that can shorten the time and obtain a high operating rate.

  That is, the gist of the invention according to claim 1 includes a plurality of pairs of rolling rolls arranged in series, and a drive control circuit that controls a drive current of an electric motor that rotationally drives the plurality of pairs of rolling rolls. A rolling apparatus of a type that forms a loop of the material to be rolled between a predetermined pair of rolling rolls in the process of rolling the material to be rolled through a plurality of pairs of rolling rolls that are each driven to rotate by an electric motor, ) Provided in a drive control circuit that controls a drive current of an electric motor that rotationally drives a rolling roll that is preset and positioned upstream of the reference rolling roll among the plurality of pairs of rolling rolls, and generates electromagnetic braking on the electric motor (B) rear end passage determining means for determining that the rear end of the material to be rolled has passed through a rolling roll positioned upstream of the reference rolling roll, and (c) When it is determined by the rear end passage determining means that the rear end of the material to be rolled has passed, the drive control circuit stops supplying the drive current to the motor of the rolling roll located on the upstream side, and Drive control means for operating the electromagnetic braking circuit to perform electromagnetic braking of the electric motor.

  The invention according to claim 2 is characterized in that the electromagnetic braking circuit of the invention according to claim 1 shorts the terminals of the electric motor via a predetermined load.

  In the invention according to claim 3, the drive control means of the invention according to claim 1 or 2 reduces the rotational speed of the electric motor of the rolling roll located on the upstream side up to a preset standby rotational speed. It is characterized by being.

  Further, the invention according to claim 4 is the invention according to claim 3, wherein (a) a new roll is added to the pair of rolling rolls positioned in the most upstream part of the plurality of pairs of rolling rolls arranged in series. (B) determining that the rotational speed of the motor of the rolling roll located on the upstream side has decreased to the standby rotational speed, and immediately adding a new material to the rolled material supply apparatus. It further includes supply control means for supplying the material to be rolled to a pair of rolling rolls positioned at the most upstream part.

  Further, the invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein a loop of a material to be rolled is formed between the reference rolling roll and the rolling roll located on the upstream side. A loop forming device is provided, and the drive control means increases the rotation speed of the electric motor of the rolling roll located on the upstream side according to the loop forming device forming a loop at the tip of the material to be rolled. It is a thing to let it be.

  According to the first aspect of the present invention, when it is determined by the rear end passage determining means that the rear end of the material to be rolled has passed, the rolling that is positioned on the upstream side in the drive control circuit by the drive control means. Since the supply of the drive current to the motor of the roll is stopped and at the same time the electromagnetic braking circuit is operated to perform the electromagnetic braking of the motor, the rotation speed of the motor can be reduced more quickly than natural deceleration. In the upstream rolling roll, the waiting time from when the end of the material to be rolled during rolling passes until the end of the next material to be rolled can be shortened, and the operating rate of the rolling apparatus is increased.

  In addition, according to the invention according to claim 2, the electromagnetic braking circuit is configured to be relatively simple because the terminal of the electric motor is short-circuited via a predetermined load. Also, it can be easily attached.

  Further, according to the invention according to claim 3, the drive control means reduces the rotational speed of the motor of the rolling roll located on the upstream side up to a preset standby rotational speed. The tip of the material to be rolled is not damaged and is easily bitten between the rolling rolls.

  Moreover, according to the invention which concerns on Claim 4, (a) The to-be-rolled body which supplies a new to-be-rolled material to a pair of rolling roll located in the most upstream part among the several pairs of rolling rolls arrange | positioned in series And (b) determining that the rotation speed of the motor of the rolling roll located on the upstream side has decreased to the standby rotation speed, and immediately adding a new material to be rolled to the material to be rolled to the rolling material supply device. Supply control means for supplying to a pair of rolling rolls located in the upstream portion, and in the upstream rolling roll, after the end of the rolling material being rolled passes, the tip of the next rolling material The waiting time until charging is reduced, and the tip of the material to be rolled is supplied quickly without wasting time, so that the operating rate of the rolling apparatus is further increased.

  According to the invention of claim 5, a loop forming device is provided for forming a loop of the material to be rolled between the reference rolling roll and the rolling roll located on the upstream side, and the drive control means Is to increase the rotational speed of the electric motor of the rolling roll located on the upstream side according to the fact that the tip of the material to be rolled is formed by the loop forming device to form a loop. In the roll, there is no influence of tension or compression force, and a good product with high dimensional accuracy can be obtained.

  Hereinafter, a wire rod rolling device 10 according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram for explaining the overall configuration of the wire rod rolling device 10. In FIG. 1, rolling stands Sn (n is an integer larger than 1) having a plurality of pairs of rolling rolls RVna and RVnb or RHna and RHnb are arranged in series, and the cross-sectional area is increased in the process of passing the wire 12 in order. The rolling process is performed so as to be sequentially reduced to a desired diameter. The wire rod rolling device 10 includes, in order from the upstream side, a first intermediate row 14, a second intermediate row 16, a first play finishing mill (PFM) 18, a second play finishing mill (PFM) 20, a reducing mill ( RM) 22 and a sizing mill (SM, finishing mill) 24. They all have one or more rolling stands SV and SH alternately. In FIG. 1, a vertical stand SV shown in a rectangle is one in which rolling rolls RVna and RVnb are arranged around a vertical axis, and the cross section of the wire 12 is, for example, an ellipse having a long axis in the thrust direction. Roll. The horizontal stand SH shown in the upper and lower two circles is one in which the rolling rolls RHna and RHnb are arranged around the horizontal axis, and is rolled, for example, so that the cross section of the wire 12 becomes circular.

  In FIG. 1, a stand SH18 located at the end of the reducing mill (RM) 22 functions as a reference stand of this embodiment, and the rotational speeds of the rolling rolls RH18a and RH18b of the reference stand are set as described later. As a reference, the rotational speed of the rolling rolls RHna and RHnb (n <18) on the upstream side is corrected and controlled.

  Since the rolling stands SV and SH constituting the wire rod rolling device 10 are configured in the same manner, the upstream portion of the wire rod rolling device 10, for example, the configuration of the rolling stand SH8 belonging to the first intermediate row 14 is represented. This will be described with reference to FIG. The stand SH8 includes a pair of rolling rolls RH8a and RH8b provided so as to be able to rotate the pair of rolling rolls RH8a and RH8b around a horizontal axis, not shown. The pair of rolling rolls RH8a and RH8b are operatively connected to each other via a pair of synchronous gears AH8a and AH8b so that their rotation directions are opposite but their rotations are synchronized. One synchronous gear AH8a of the pair of synchronous gears AH8a and AH8b is connected to the electric motor MH8 via a pinion gear PH8 fixed to the output shaft TH8 of the electric motor (mil motor) MH8, and a pair of rolling rolls RH8a and RH8b. The motor MH8 is rotationally driven. The one synchronous gear AH8a and the pinion gear PH8 meshing with it constitute a reduction gear GH8. The wire 12 is plastically deformed so as to follow the cross-sectional shape of the forming grooves FH8a and FH8b formed on the outer peripheral surfaces thereof by being pinched between the pair of rolling rolls RH8a and RH8b.

  FIG. 3 is a diagram for explaining an electrical configuration centering on the rolling stands SV8 and SH8 belonging to the first intermediate row 14, which is a main part of the electronic control device 28 provided in the wire rod rolling device 10. FIG. The electronic control unit 28 is constituted by a so-called microcomputer that processes an input signal in accordance with a program stored in advance, for example. In FIG. 3, the electric current MV8 of the rolling stand SV8 and the electric motor MH8 of the rolling stand SH8 are controlled by the drive control circuit DV8 and the drive control circuit DH8 so that the rotation speed is controlled. Since the drive control circuit DV8 and the drive control circuit DH8 are configured similarly, the drive control circuit DH8 will be described below as a representative.

  As shown in FIG. 4, in the drive control circuit DH8, a thyristor 32 and a breaker 34 are inserted in series in a closed circuit of the power supply 30 and the electric motor MH8. The thyristor 32 controls the drive current supplied from the power supply 30 to the electric motor MH8. The breaker 34 is a switching device that is opened when an overcurrent occurs. This electric motor MH8 is provided with another closed circuit. In this other closed circuit, an emergency switch 36 and a first resistor 38 are provided in series, and the emergency switch 36 includes a braking switch 40, a detection / protection circuit connected in series to each other. 42 and the second resistor 44 are provided in parallel. The motor MH8 is composed of, for example, a DC motor. When the driving current is supplied to a rotor terminal and the driving current is not supplied, the emergency switch 36 or the brake switch 40 is closed. As a result, electromagnetic braking, that is, regenerative braking is generated. In this embodiment, the brake switch 40, the first resistor 38, and the second resistor 44 constitute an electromagnetic brake circuit 46.

  Returning to FIG. 3, the rolling stand SV8 and the rolling stand SH8 are provided with rotational speed detectors BV8 and BH8 for detecting the rotational speeds of the electric motors MV8 and MH8. Further, between the rolling stand SV8 and the subsequent rolling stand SH8, and between the rolling stand SH8 and the subsequent rolling stand SV9, a pair of fulcrum rollers EV8a and EV8b, EH8a and EH8b, and a kicking roller JV8 and JH8 and loop height detectors KV8 and KH8 are provided, respectively, so that the loop (sag) of the wire 12 is appropriately formed. In this embodiment, the fulcrum rollers EV8a and EV8b, EH8a and EH8b, kicking rollers JV8 and JH8, loop height detectors KV8 and KH8, and the like constitute a loop forming device 48.

  The target loop height setters LV8 and LH8 include a target loop height HmV8 between the rolling stand SV8 and the subsequent rolling stand SH8, and a target loop height between the rolling stand SH8 and the subsequent rolling stand SV9. HmH8 is set according to the manual operation. The comparison means NV8 and NH8 include the target loop height HmV8 and target loop height HmH8 set by the target loop height setters LV8 and LH8, and the actual loop height detected by the loop height detectors KV8 and KH8. Differences ΔHV8 (= HmH8−HV8) and ΔHH8 (= HmH8−HH8) between HV8 and loop height HH8 are calculated.

  In the rolling stand SH8, the drive control means QH8 is configured so that the rotational speed of the rolling rolls RH8a and RH8b is set to the standby rotational speed Nw commanded for each stand from the rotational speed setter 50 in consideration of the area reduction rate of each stand. The drive control circuit DH8 is controlled so that the target value Nt (= Nw × RR) corrected by the increase correction value indicating the increase ratio RR (1 ≧ 0) output from the drive control means at the subsequent stage (not shown) is obtained. . The increase correction value is a value RR obtained by dividing the actual rotation speed of the preceding stage roll by the rotation speed before correction in order to enable stable rolling over the entire rolling line, and is calculated for each preceding stage stand. Is done. In the reference stand SH18, since the rolling rolls RH18a and RH18b are rotated at the rotation speed commanded from the rotation speed setting device 50, the increase ratio RR is 1. The reason why the increase ratio RR becomes 1> 0 as the rolling stand is on the upstream side is mainly due to the formation of loops.

  At the same time, the drive control means QH8 corrects the rotation speeds of the rolling rolls RH8a and RH8b so that the difference ΔHH8 is eliminated. For example, when the loop height between the rolling stand SH8 and the subsequent rolling stand SV9 becomes high and the difference ΔHH8 becomes negative, the rolling roll RH8a of the rolling stand SH8 so that the difference ΔHH8 becomes zero. Then, a rotational speed correction value ΔNA for increasing the rotational speed of RH8b is determined, and the target value Nt is corrected by the rotational speed correction value ΔNA. Eventually, the drive control means QH8 controls the drive control circuit DH8 so that the rotation speeds of the rolling rolls RH8a and RH8b become the corrected target value Nt ′ (= Nw × RR + ΔNA). Then, the drive control means QH8 calculates the increase ratio RR in the rolling stand SH8 by dividing the actual rotation speed of the rolling rolls RH8a and RH8b by the standby rotation speed Nw commanded from the rotation speed setter 50. The correction value is supplied to the drive control means QV8 of the upstream rolling stand SV8.

  By the control by the drive control means QH8, the rotational speed of the rolling rolls RH8a and RH8b of the rolling stand SH8, that is, the rotational speed of the electric motor MH8, the tip of the wire 12 passes through each rolling stand of the rolling device 10 as shown in FIG. At the same time, as the loop is formed, the standby rotation speed Nw is sequentially increased, and becomes substantially constant when reaching a predetermined rolling rotation. When the rotation speed of the electric motor MH8 becomes constant, it means that the tip of the wire 12 has reached the rolling stand SH18 which is a reference stand. Thereafter, the constant value is continued until the end of the wire 12 passes.

  In the rolling stand SH8, when the rear end (terminal) of the wire 12 passes, a phenomenon occurs in which the rotational speed of the rolling rolls RH8a and RH8b, that is, the rotational speed of the electric motor MH8 temporarily increases. Since the drive control means QH8 determines that the end of the wire 12 has passed based on the change in the rotation speed of the electric motor MH8, it also functions as a rear end passage determination means. The drive control means QH8 determines that the end of the wire 12 has passed based on the change in the rotational speed of the electric motor MH8, stops the rotational driving of the electric motor MH8, and at the same time the rotational speed of the electric motor MH8 becomes the standby rotational speed Nw. The drive control circuit DH8 is controlled so as to rapidly decrease until the motor MH8 is electromagnetically braked. That is, in the drive control circuit DH8 of FIG. 4, the drive current supplied from the thyristor 32 to the electric motor MH8 is made zero, and at the same time, the braking switch 40 is closed to generate electromagnetic braking, that is, regenerative braking. In FIG. 5, t1 indicates the passage determination time point of the end of the wire 12. After the time point t1, the alternate long and short dash line indicates the rotational speed during the electromagnetic braking, and the solid line indicates the rotational speed by the conventional natural deceleration.

  Also in the rolling stand SV8 adjacent to the upstream side of the rolling stand SH8, the drive control means QV8 operates in the same manner as the drive control means QH8. That is, the drive control means QV8 drives the standby rotation speed Nw commanded for each stand from the rotation speed setting device 50 in consideration of the area reduction rate of each stand, with the rotation speed of the rolling rolls RV8a and RV8b being driven in the subsequent stage. In order to calculate the value Nt (= Nw × RR) corrected by the increase correction value indicating the increase ratio RR (1 ≧ 0) output from the control means QH8, and to set the loop height to the target loop height HmH8. The corrected target value Nt ′ (= Nw × RR + ΔNA) is calculated by correcting the value Nt with the rotational speed correction value ΔNA of the rotation speed, and the rotational speeds of the rolling rolls RV8a and RV8b are set to the corrected target value Nt ′. Thus, the drive control circuit DV8 is controlled. Further, the drive control means QV8 determines that the end of the wire 12 has passed based on the change in the rotational speed of the electric motor MV8, stops the rotational driving of the electric motor MV8, and at the same time the rotational speed of the electric motor MV8 becomes the standby rotational speed. The drive control circuit DV8 is controlled so as to rapidly decrease to Nw, and electromagnetic braking is generated in the electric motor MV8.

  A wire supply device 54 for supplying the wire 12 to the first intermediate row 14 one by one in accordance with a command from the electronic control device 28 is provided in the preceding stage of the first intermediate row 14. In this wire rod supply device 54, the wire rod 12 rolled to a predetermined size by another rolling device is prepared. The supply control means 52 is detected by the rotational speed detector BH8 that the rotational speed of the rolling stand located on the upstream side of the rolling apparatus 10, for example, in this embodiment, the rotational speed of the electric motor MH8 of the rolling stand SH8 has decreased to the standby rotational speed Nw. A determination is made based on the actual rotational speed, and the new wire 12 is immediately supplied to the wire supply device 54 to the pair of rolling rolls of the rolling stand SV7 located at the most upstream part.

  As described above, according to the present embodiment, when it is determined by the rear end passage determining means (drive control means QH8) that the rear end of the wire 12 has passed, the drive control means QH8 causes the drive control circuit DH8 to The supply of drive current to the electric motor MH8 that drives the rolling rolls RH8a and RH8b of the rolling stand SH8 in the first intermediate row 14 is stopped, and at the same time, the electromagnetic braking circuit 46 of the drive control circuit DH8 is operated to Since the braking is performed, the rotational speed of the electric motor MH8 is quickly reduced as compared with natural deceleration. Therefore, in the rolling rolls RH8a and RH8b, after the end of the wire 12 being rolled passes, The waiting time until the tip is inserted can be shortened, and the operating rate of the wire rod rolling device 10 is increased.

  6 and 7 show the results of experiments conducted by the present inventors under the same conditions except for the braking conditions. FIG. 6 shows a state in which the rotational speed of the motor MH8 is reduced when the motor MH8 is not electromagnetically braked and is naturally decelerated. In this case, the natural deceleration time from the end of the wire 12 to the standby rotational speed Nw is 11 .5 seconds were required. On the other hand, FIG. 7 shows a state in which the rotational speed of the electric motor MH8 is lowered when electromagnetic braking is performed. In this case, the electromagnetic braking time from the end of the wire 12 to the standby rotational speed Nw is 2.9. Second was needed. Once the rotational speed of the electric motor MH8 is reduced to the standby rotational speed Nw, the tip of the next wire 12 can be bitten without any trouble. Therefore, as shown in FIG. The time can be greatly reduced. In this experimental example, it is possible to shorten 8.6 seconds per piece. Therefore, when 1000 rolls are performed per day, operation of 8600 seconds, that is, 143 minutes can be increased per day.

  Further, according to the present embodiment, the electromagnetic braking circuit 46 of the drive control circuit DH8 shorts the terminals of the electric motor MH8 of the rolling stand SH8 via the first resistor 38 and the second resistor 44. Since it is relatively simple, it can be easily attached to conventional equipment.

  Further, according to the present embodiment, the drive control means QH8 reduces the rotation speed of the electric motor MH8 that drives the rolling rolls RH8a and RH8b of the rolling stand SH8 in the first intermediate row 14 to a preset standby rotation speed Nw. Since it is a thing, the front-end | tip of the next wire 12 is not damaged, but is easily bite between rolling rolls RH8a and RH8b.

  In addition, according to the present embodiment, a new wire rod 12 is fed to the pair of rolling rolls of the rolling stand SV7 located at the most upstream part of the plurality of pairs of rolling rolls arranged in series in the wire rod rolling mill 10. 54, it is determined that the rotational speed of the motor MH8 that drives the rolling rolls RH8a and RH8b of the rolling stand SH8 located upstream of the rolling apparatus 10 has decreased to the standby rotational speed Nw. And further includes supply control means 52 for supplying the wire rod 12 to the pair of rolling rolls of the rolling stand SV7. Therefore, in the rolling roll SH8 positioned at the upstream portion of the wire rod rolling mill 10, the end of the wire rod 12 being rolled. The waiting time from when the wire passes until the next tip of the wire 12 is thrown in can be shortened, and the tip of the wire 12 can be provided quickly without wasting time. Since the operating rate of the wire rolling apparatus 10 is further improved.

  Further, according to the present embodiment, the loop forming device 48 for forming a loop of the wire 12 is provided between the reference rolling stand SH18 and the rolling stand SH8 positioned at the upstream portion of the wire rod rolling device 10, and the driving The control means QH8 increases the rotation speed of the electric motor MH8 of the rolling roll SH8 located in the upstream portion of the rolling device 10 in accordance with the loop forming device 48 forming a loop at the tip of the wire 12. For this reason, in the rolling roll SH8 on the side positioned in the upstream portion, a good product having no dimensional accuracy and high dimensional accuracy can be obtained.

  As mentioned above, although this invention was demonstrated based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the supply control unit 52 indicates that the rotation speed of the electric motor MH8 of the rolling stand located on the upstream side of the wire rod rolling apparatus 10, for example, the rolling stand SH8 in this embodiment, has decreased to the standby rotation speed Nw. Judgment was made based on the actual rotational speed detected by the rotational speed detector BH8, and the new wire 12 was immediately supplied to the pair of rolling rolls of the rolling stand SV7 located at the most upstream part by the wire supply device 54. However, it may be determined that the rotational speed of the electric motor of the rolling stand SV7 located at the most upstream part of the first intermediate row 14 has decreased to the standby rotational speed Nw. Since it is a relatively short time, the rotational speed of the motor of any rolling stand in the first intermediate row 14 may be used.

  In the above-described embodiment, the electric motor MH8 is a DC motor that supplies a drive current to the rotor. The electromagnetic control circuit 46 performs electromagnetic braking by short-circuiting the terminal of the electric motor MH8 via a predetermined load. However, an AC motor that supplies a drive current to the stator may be used as the electric motor MH8. In this case, the electromagnetic control circuit 46 can generate electromagnetic braking by supplying a direct current to the electromagnetic control circuit 46 in a fixed state.

  In the above-described embodiment, the rear end passage determining means (drive control means QH8) has determined that the rear end of the wire 12 has passed based on the change in the rotational speed of the electric motor MH8. In order to determine or detect the passage of the rear end, other determination means such as a photoelectric sensor, an electromagnetic sensor, and an ultrasonic sensor may be used.

  In addition, the rolling device 10 of the above-described embodiment includes a first intermediate row 14, a second intermediate row 16, a first play finishing mill (PFM) 18, a second play finishing mill (PFM) 20, and a reducing mill. (RM) 22 and sizing mill (SM, finishing mill) 24 are provided. However, such a mill (rolling stand) is not necessarily provided. In short, it is only necessary that a plurality of rolling stands are arranged in series.

  Further, in the rolling apparatus 10 of the above-described embodiment, the rolling stand SH18 at the rearmost end of the reducing mill 22 is the reference rolling stand. Or a rolling stand in the sizing mill 24 may be used.

  Further, in the wire rod rolling device 10 of the above-described embodiment, when the drive control means QH8 determines that the rear end of the wire rod 12 has passed, it is driven so that the rotational speed of the electric motor MH8 rapidly decreases to the standby rotational speed Nw. Although the control circuit DH8 is controlled and electromagnetic braking is generated in the electric motor MH8, the passage determination of the rear end of the wire 12 does not necessarily have to be the passage determination in the rolling stand SH8. The passage determination of the drive control means QV8 in the adjacent rolling stand SV8 may be used. Further, the electromagnetic braking to the electric motor MH8 by the drive control means QH8 does not necessarily have to be performed until the rotational speed of the electric motor MH8 reaches the standby rotational speed Nw. The standby rotational speed Nw is used to prevent the rotational speed from overshooting. You may make it carry out to just before it falls.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

It is a figure for demonstrating the whole structure of the wire-rolling apparatus which is one Example of this invention. It is a figure explaining the drive structure of the rolling roller of the rolling stand located in an upstream among the rolling stands of the wire-rolling apparatus of the Example of FIG. It is a block diagram explaining the principal part of the electronic controller provided in the wire-rolling apparatus of the Example of FIG. It is a figure explaining the circuit structure of the drive control circuit provided for every rolling stand in FIG. In the rolling stand of FIG. 2, it is a figure explaining the rotational speed of the rolling roll after biting the front-end | tip of a wire, and after the rear end of a wire passed, respectively. It is a figure which shows the experiment result of this inventor, Comprising: In the rolling stand of FIG. 2, it is a figure explaining the change of the rotational speed of the rolling roll after the rear end of the wire rod in the case where electromagnetic braking is not performed. is there. It is a figure which shows the experimental result of this inventor, Comprising: In the rolling stand of FIG. 2, it is a figure explaining the change of the rotational speed of the rolling roll after the rear end of a wire in the case of performing electromagnetic braking. .

Explanation of symbols

10: Wire rod rolling device (rolling device)
12: Wire rod (rolled material)
46: Electromagnetic braking circuit 48: Loop forming device 52: Supply control means 54: Wire material supply devices RVna, RVnb, RHna, RHnb: Rolling roll MV8, MH8: Electric motor DV8, DH8: Drive control circuit QV8, QH8: Drive control means ( Rear end passage judging means)

Claims (5)

A plurality of pairs of rolling rolls arranged in series; and a drive control circuit for controlling a drive current of an electric motor that rotationally drives the plurality of pairs of rolling rolls. In the process of rolling a rolled material, a rolling device of a type that forms a loop of the material to be rolled between a predetermined pair of rolling rolls,
Provided in a drive control circuit that controls a drive current of an electric motor that rotationally drives a rolling roll that is preset and positioned upstream of the reference rolling roll among the plurality of pairs of rolling rolls, and generates electromagnetic braking in the electric motor An electromagnetic braking circuit for
Rear end passage determining means for determining that the rear end of the material to be rolled has passed through the rolling roll located on the upstream side of the reference rolling roll;
When it is determined by the rear end passage determining means that the rear end of the material to be rolled has passed, the drive control circuit stops supplying the drive current to the motor of the rolling roll located on the upstream side, And a drive control means for operating the electromagnetic braking circuit to perform electromagnetic braking of the electric motor. The rolling device according to claim 1, wherein the electromagnetic braking circuit short-circuits a terminal of the electric motor via a predetermined load. 3. The rolling apparatus according to claim 1, wherein the drive control unit is configured to reduce a rotational speed of an electric motor of a rolling roll located on the upstream side to a preset standby rotational speed. A rolled material supply device that supplies a new rolled material to a pair of rolling rolls located in the most upstream part of the plurality of pairs of rolling rolls arranged in series,
It is determined that the rotational speed of the electric motor of the rolling roll located on the upstream side has decreased to the standby rotational speed, and a new material to be rolled is immediately placed on the material to be rolled material supply device, and a pair of rollings located at the most upstream portion The rolling apparatus according to claim 3, further comprising supply control means for supplying the roll. A loop forming device for forming a loop of the material to be rolled is provided between the reference rolling roll and the rolling roll located on the upstream side,
The drive control means increases the rotation speed of the electric motor of the rolling roll located on the upstream side in accordance with a loop formed at the tip of the material to be rolled by the loop forming device. The rolling apparatus in any one of thru | or 4.

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