JP2521732B2 - Rolling method for re-rolling between running rolls of tandem rolling mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a running roll changing method of a tandem rolling mill for changing rolls without stopping rolling, and particularly to minimizing off gauge and reducing changing time. Suitable for reducing.

[Prior Art] Conventionally, as a running roll changing method of a tandem mill for changing rolls without stopping rolling, Japanese Patent Publication No. 53-34
The one described in Japanese Patent No. 582 is known. According to this, the rolling speed is reduced before roll change, the front and rear tensions of the stand relating to roll change are matched, and the rear change stand is then separated from the rolling, and at the same time, the rolling reduction ratio of the remaining stands is reduced. The number of rolls is increased so that the rolls can be exchanged without stopping the rolling, and the finished plate thickness is to be obtained.

[Problems to be solved by the invention]

However, in the above-mentioned conventional technique, no consideration has been given to the off-gauge of the rolled material during roll reassembling and the time required for reassembling.

That is, according to the above-mentioned conventional method, before changing the rolls during running, the rolling speed is lowered and the value of the tension is changed to equalize the front tension and the rear tension, and then the rolls of the rearrangement stand are opened. At the same time, since the rolling reduction of the remaining stands is changed, there is a problem that the original rolling schedule must be disengaged during this operation, and the rolling state must be transited at a low speed for a long time.

Further, since the plate thickness change caused by the roll opening of the reassembling stand is not corrected at all, that is, it is not corrected by the synchronous operation of the rolling reduction ratio of the other stands, the plate thickness accuracy is There was a problem that the consideration for continuing stable rolling was lacking, such as bad and deterioration of the plate shape.

An object of the present invention is to solve the above conventional problems,
In other words, it is an object of the present invention to provide a method for changing the running rolls of a tandem rolling mill, which can prevent the occurrence of a strip thickness off gauge during a transition during the changing of running rolls.

[Means for solving problems]

The present invention, in order to achieve the above object, a method of recombining running rolls, predetermining a rolling schedule during recomposition by a non-recombinant stand other than the stand used for roll recomposition, and based on a roll recomposition command. Virtually set a reclassification point on the material to be rolled, and track the progress position of the virtual set reclassification point obtained by the rotation signal of the roll while correcting it by the roll diameter and the advance rate, and set the virtual setting. When the reclassification point reaches the non-recombined stand, the reduction position of the non-recombined stand is changed to the reduction position during recomposition based on the rolling schedule, and the recomposition point is adjacent to the upstream side of the non-recombined stand. When the rolling speed of the non-recombined stand is changed to a value during recomposition based on the rolling schedule, and when the virtually set recombining point reaches the stand for recombining rolls, the roll While opening the roll of the stand used for the reshuffling, changing the rolling speed of the non-recombined stand adjacent to the upstream side of the stand used for the reshuffling of the roll to a value during the reshuffling based on the rolling schedule. It is configured to include.

In addition, when opening the roll of the rearrangement stand,
In order to equalize the front and rear tensions of the stand, it is desirable to correct the rolling speed of the non-recombined stand adjacent to the stand and on the upstream side.

Further, in the present invention, it is not necessary to particularly lower the entire rolling speed during the reassembling, but it is desirable to lower it in view of work safety such as reassembling work.

[Action]

With such a configuration, the other non-recombined stands except the recombined stand are corrected to rolling schedules being recombined one after another as the virtual recombined point progresses, and the recombined stand becomes the virtual recombined point. Will be released when it reaches directly below. Therefore, the material to be rolled behind the virtual reassignment point as a boundary is uniformly rolled according to the rolling schedule during the reassignment. Then, on the exit side of the final stand, the plate thickness of the rolled material is maintained at a predetermined plate thickness regardless of before and after the virtual reassembling point, and the occurrence of off gauge during transition of reassembling is prevented. Become.

Further, when the roll of the reassembling stand is opened, just before the material to be rolled and the roll are separated, that is, by equalizing the front tension and the rear tension at the same time as the roll opening operation,
It is possible to reduce the shock caused by the sudden change in the tension due to the roll opening, and to shorten the time required to open the roll.

Note that the procedure for causing the reassembling stand to participate in rolling after the roll reassembling is possible by performing the same operation as above in the opposite direction.

〔Example〕

 Hereinafter, the present invention will be described based on examples.

FIG. 1 shows an overall system configuration diagram of a tandem rolling mill according to an embodiment to which the present invention is applied. As shown in the figure, this embodiment has five rolling stands 1 to 5. The bridle roll 6 arranged on the upstream side of the No. 1 stand 1 and the pulse generators PLGs 10 to 15 for detecting the rotation speed of the rolls are attached to the stands 1 to 5, respectively. Also, No. 1 to No. 5 stands 1 to 5
The roll positioning devices RPC21 to 25 and the roll speed control devices ASR31 to 35, respectively, are provided for adjusting the roll reduction position by positioning the rolls of the corresponding stands and controlling the rotation speed of the rolls. It has become. The rotation speed signals detected by the pulse generators PLGs 10 to 14 are tracking counters 40, respectively.
Has been entered in ~ 44. Each tracking counter 40-44
Corrects the rotation speed signal based on the roll diameter, the advance rate, etc., and thereby tracks the advancing position of the virtual recombining point set on the material to be rolled.

Using the embodiment configured in this way, the operation will be described by taking as an example the case where the rolls of the No. 3 stand 3 are rearranged between runs. When a rearrangement command is input to the tracking counter 40 according to the operator's instruction, a virtual rearrangement point is set on the material to be rolled located at the predetermined position of the bridle roll 6 at that time, and this is used as a reference. Tracking counter 40
Is started. The tracking counter 40 corrects the output pulse as a rotation speed signal input from the PLG 10 with the roll diameter of the bridle roll 6 and the advance rate to track the progress of the virtual recombining point. The tracking counter which is spaced a distance l ₁ between the bridle roll 6 and No.1 stand 1 is preset to 40, the virtual reclassifications point No.1 stand 1 when the count value matches the l ₁ Upon recognizing that it has reached the position immediately below, the count-up signal is output to the RPC 21 and the tracking counter 41 to be reset.

When the count-up signal is applied from the tracking counter 40, the RPC 21 changes the roll reduction position of the No. 1 stand 1 based on a predetermined rolling schedule during recomposition, as shown in FIG. To do. As a result, the material to be rolled after the virtual reassignment point is rolled by the No. 1 stand 1 based on the rolling schedule being reassigned.

On the other hand, the tracking counter 41 is activated at the same time when the count-up signal of the tracking counter 40 is input, counts the output pulses according to the rotation speed output from the PLG 11, and sets the preset No. 1 stand 1 And No.2
When the count value corresponding to the separation distance l _{2 from the} stand 2 is reached, a count-up signal is output to the ASR 31 of the No. 1 stand 1, the RPC 22 and the tracking counter 42 of the No. 2 stand 2. As a result, similarly to the case of the No. 1 stand 1, the rolling position of the No. 2 stand 2 is changed to the rolling position during the roll rearrangement, as shown in FIG. At the same time, the ASR31 changes the rolling speed of the No. 1 stand 1 to the rolling speed during the rearrangement.

Similarly, the tracking counter 42 tracks the position of the virtual shuffle point between the No. 2 stand 2 and the No. 3 stand 3, and the virtual shuffle point reaches directly below the No. 3 stand 3. Sometimes a count-up signal is output. This count-up signal is output to the ASR 32 related to No. 2 stand 2 and the RPC 23 related to No. 3 stand 3.

When the count-up signal is input to the RPC23 of the No.3 stand 3 which is the rearrangement stand, the RPC23 opens the roll and at the same time outputs the speed correction signal to the ASR32 and 33 by the rolling position signal, and the No.2 stand 2 The tension between the stands (rear tension) between the No. 3 stand 3 and the No. 3 stand 3 is
o.4 Control the tension between stands (front tension) between stands 4 to be equal. The front or rear tensions are controlled based on the values detected by the tension detecting devices provided between the corresponding stands. Further, it goes without saying that the target value of the tension control is set based on the rolling schedule being recombined. Further, the influence of the tension variation on the upstream stand due to the tension control is performed through the tension control circuit of a normal tandem rolling mill.

The tracking of the virtual reassignment point between No. 3 stand 3 and No. 4 stand 4 cannot be performed by the tracking counter 43 because the No. 3 stand 3 is opened, so No. 2
The tracking counter 42 associated with the stand 2 is used. That is, the tracking counter 42 is restarted immediately after counting up the number of pulses corresponding to l ₃ , and counts the number of pulses corresponding to the separation distance l ₄ between the No. 3 stand 3 and the No. 4 stand 4, The recount up signal is output to the ASR 32 related to the recount up No. 2 stand 2, and at the same time, the recount up signal is output to the RPC 24 and the tracking counter 44 related to the No. 4 stand 4. As a result, the rolling speed of the No. 2 stand 2 is corrected again, and at the same time, the rolling position of the No. 4 stand 4 is changed to the value being reassembled. On the other hand, the tracking counter 44 tracks the virtual reassignment point and outputs a count-up signal to the ASR 34 associated with No. 4 stand 4 and the RPC 25 associated with No. 5 stand 5 when the count value matches l ₅ . As a result, the rolling speed of the No. 4 stand is changed to the value being recombined, and the rolling position of the No. 5 stand is changed to the value being recombined.

As described above, according to the present embodiment, by adopting such a configuration, the other non-recombinant stands except the recombining stand are rolled during the recombining with the next one as the virtual recombining point progresses. Since the reassembling stand is opened when the virtual reassembling point reaches directly below, the material to be rolled is uniformly rolled at the virtual reassembling point according to the rolling schedule being reconstructed. Will be. Then, on the exit side of the final stand, the plate thickness of the material to be rolled will be maintained at a predetermined plate thickness regardless of before and after the virtual reassembling point, and the occurrence of off-gauge during the reassembling transition will be prevented. .

Further, when the roll of the reassembling stand is opened, the front tension and the rear tension are made equal until immediately before the material to be rolled and the roll are separated from each other, that is, at the same time when the roll is opened. The shock can be reduced and the time required for opening the roll can be shortened.

Note that the procedure for causing the reassembling stand to participate in rolling after the roll reassembling is possible by performing the same operation as above in the opposite direction.

〔The invention's effect〕

As described above, according to the present invention, it is possible to prevent the occurrence of the sheet thickness off gauge at the time of transition during the reassembling during the roll reassembling during the reassembling of the rolls without stopping the rolling. Therefore, there is an effect that the rolling efficiency can be improved and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an embodiment apparatus to which the present invention is applied, and FIG. 2 is a diagram for explaining the operation of the present invention. 1-5 ... Rolling stand, 6 ... Bridle roll, 10
〜15 …… Pulse generator, 21〜25 …… Roll positioning device, 31〜35 …… Roll speed controller, 40〜44 …… Tracking counter.

Claims (2)

(57) [Claims] 1. A rolling schedule during recomposition by a non-recombined stand other than a stand used for recomposing rolls is preliminarily determined, and a recombining point is virtually set on a material to be rolled based on a roll recomposing command, and rolls are set. Roll diameter of the advancing position of the virtually set reclassification point obtained by the rotation signal of
Tracking while correcting by the advanced rate, when the virtually set recombining point reaches the non-recombining stand, the rolling position of the non-recombining stand is changed to the rolling position during recombining based on the rolling schedule. While changing the rolling speed of the non-recombinant stand adjacent to the upstream side of the non-recombinant stand to a value during recomposition based on the rolling schedule, the virtually set recombining point is the recomposition of the roll. When reaching the stand to be served, the roll of the stand to be used for recombining the roll is opened and the rolling speed of the non-recombined stand adjacent to the upstream side of the stand to be used for recomposing the roll is set based on the rolling schedule. A method for re-rolling running rolls of a tandem rolling mill, comprising changing to a value being changed. 2. When the roll of the reassembling stand is opened, the rolling speed of the non-recombining stand adjacent to the stand and the upstream side is corrected so as to equalize the front and rear tensions of the stand. A running roll reassembling method for a tandem rolling mill according to claim 1.