JPH0596311A - Roll recombination method - Google Patents

Abstract

PURPOSE:To provide a roll recombination method which does not sacrifice a rolled stock. CONSTITUTION:When a 1st starting point arrives at a prescribed position before an i-th(i=1,...n) rolling mill, only a set value of speed of the i-th rolled stock is changed by a 1st step from a 1st schedule to a 3rd schedule. When the 1st starting point arrives at the 1st rolling mill, the set values of rolling reduction and tension of the i-th rolling mill are changed by a 2nd step from the 1st schedule to the 3rd schedule and simultaneously, each set value of a (i-1)th rolling mill is changed from the 3rd schedule to the 2nd schdule. After this process is repeated, each set value of the n-th rolling mill is changed from the 3rd schedule to the 2nd schedule, each of the set values of all rolling mills is made the 2nd schedule to simplify the change of the roll.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll changing method for changing rolls during rolling of a rolled material by a continuous rolling mill.

[0002]

2. Description of the Related Art Generally, a continuous cold rolling mill (hereinafter also referred to as a tandem mill) comprises a plurality of rolling mills (hereinafter also referred to as stands) obtained by reducing a predetermined plate thickness. This rolling mill is widely used because its initial investment amount is higher than that of the reversing single rolling mill but the production amount is large.
Especially recently, there are two payoff reels for inserting coils on the entry side of the tandem mill, and a welding machine for welding rolled material is provided between the payoff reel and the tandem mill.
Further, a complete continuous rolling type cold tandem mill, which is provided with a facility for storing rolled material called a looper that keeps the tandem mill side in a normal rolling state during welding by this welding machine, is widely used.

In such a tandem mill, when a roll is damaged due to plate breakage of a strip as a rolled material, when roll wear reaches a prescribed value due to deterioration of the roll surface condition, and when rolling from a wide width to a narrow width. In the case of changing to a wider width after one cycle of the process, it is necessary to change the rolling rolls. Conventionally, this roll change is difficult to set the roll gap between the rolling rolls after the new roll is inserted if the rolled material remains in the tandem mill, so after cutting the strip and removing this strip from the rolling mill, Either the roll was changed or the rolling mill was stopped with the strip still inserted.

[0004]

As described above, in the conventional roll changing method, there is a problem that a part of the rolled material has to be sacrificed every time changing the roll.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a roll changing method which does not sacrifice rolled material.

[0006]

The roll reassembling method according to the present invention is carried out by rolling the first to nth rolling mills arranged in tandem and the nth rolling mill which is the final rolling mill. In a rolling facility equipped with a winder for winding rolled material, a rolling schedule in which the delivery side plate thickness of the rolling mill at the final stage becomes a predetermined plate thickness using the n rolling mills As a schedule, using n-1 rolling mills excluding rolling mills having work rolls to be replaced, a rolling schedule is set such that the exit side strip thickness of the final stage rolling mill becomes the predetermined strip thickness. 2 schedule, an intermediate schedule between the first schedule and the second schedule is the third schedule, and the point of the position of the rolled material for starting the transition from the first schedule to the second schedule The first When the starting point is set and the point at a certain position of the rolled material for starting the transition from the second schedule to the first schedule is set as the second starting point, 1) i-th rolling (i = 1, ... N) A first step of changing only the speed set value of the i-th rolling mill from the first schedule to the third schedule when the first start point reaches a predetermined position in front of the rolling mill, 2) When the first starting point reaches the i-th rolling mill, the set values of the reduction amount and the tension of the i-th rolling mill are set to the first value.
Second step of changing each set value of the (i-1) th rolling mill from the third schedule to the second schedule while changing the schedule of No. 1 to the third schedule, and 3) the nth rolling mill. After repeating the first and second steps until each set value of No. 3 becomes the third schedule, each set value of the nth rolling mill is changed when the first start point reaches the winder. The third step of changing to the second schedule, and 4) cutting the rolling mill having the work rolls to be exchanged from the rolled material, exchanging the work rolls, and after the exchange, the roll gap of the rolling mill. And a fourth step of setting the speed setting to a predetermined value, 5) When the second start point reaches a predetermined position before the i-th rolling mill, only the speed setting value of the i-th rolling mill is set. From the second schedule to the third 5) the change to a tool, and 6) when the second starting point reaches the i-th rolling mill, the rolling reduction amount and the tension set value of the i-th rolling mill are changed from the second schedule to the third schedule. 6th step of changing each set value of the i-1th rolling mill from the 3rd schedule to the 1st schedule while changing to the schedule, and 7) each set value of the nth rolling mill is set to the 3rd After repeating the fifth and sixth steps until the schedule becomes, each set value of the nth rolling mill is changed to the first schedule when the second starting point reaches the winder. And a seventh step.

[0007]

According to the roll reassembling method of the present invention thus constructed, when the first starting point reaches the predetermined position before the i-th rolling mill, the i-th rolling mill is operated by the first step. Only the speed setting value of is changed from the first schedule to the third schedule. Then, when the first starting point reaches the i-th rolling mill, the second step changes the set values of the reduction amount and the tension of the i-th rolling mill from the first schedule to the third schedule. , I-1
The setting values of the rolling mill of No. 3 are changed from the third schedule to the second schedule. By repeating this, each set value of the nth rolling mill becomes the third schedule, and when the first start point reaches the winder, the set value of the nth rolling mill is changed from the third schedule. The schedule is changed to the second schedule. In this way, when each set value of all the rolling mills becomes the second schedule, the rolling load of the rolling mill having the rolls to be replaced becomes substantially zero, and the speed set value thereof is When the rolling mill is other than the first rolling mill, the speed setting value of the former rolling mill is used, and when the rolling mill is the first rolling mill, the speed setting value of the second rolling mill is used. This allows the rolls to be replaced in the well known fourth step. After the replacement, the second schedule is changed to the first schedule by the fifth, sixth, and seventh steps.

As described above, it becomes possible to change the rolls of the rolled material during rolling, and it is possible to prevent the rolled material from being sacrificed.

[0009]

FIG. 1 is a block diagram showing an embodiment of a roll changing method according to the present invention.
And FIG. 3 will be described. FIG. 3 is a block diagram showing the configuration of a continuous rolling mill in which the roll rearrangement method according to the present invention is carried out. This continuous rolling mill consists of five stands. Each stand i (i = a, b, ... D) has a work roll 2i and a reinforcing roll 3 for rolling the rolled material 1.
have i. Each work roll 2i is driven by an electric motor 4i, and this electric motor 4i is controlled by an electric motor controller 6i based on a speed reference (set value) set by the setting computer 12. Also, each work roll 2i
The setting of the roll gap is performed by the hydraulic pressure reduction control device 11i via the hydraulic pressure reduction device 5i based on the set value of the roll gap set by the calculation 12. Further, the lower surface of the upper work roll 2i is performed by the pass line control device 10i through the pass line adjusting device 7i based on the setting signal λi from the computer 12. A tension detector 8a for detecting the tension of the rolled material 1 is provided between the stands.
8b, 8c and 8d are provided.

A rolled material 1 is produced by such a continuous rolling mill.
A case where the work roll 2b is replaced during rolling will be described as an example. The rolling schedule, that is, the reduction amount Si of each stand i, the speed setting value Vi, and the tension setting value Ti are calculated by the setting calculator 12. Now, the rolling schedule for rolling with five stands is A, the rolling schedule for rolling with four stands excluding the No. 2 stand (work roll 2b) is B, and the rolling schedule in between is Let be C. The rolling schedule in the middle is set so as to take a value approximately in the middle of the schedules A and B.

A point at a certain position on the rolled material 1 for starting the transition from the rolling schedule A to the rolling schedule B, that is, the transition starting point is X. This starting point X is N
o. When the predetermined position Yma before the 1st stand a is reached, only the speed setting value of the No. 1 stand is changed from VA _a (A schedule) to VC _a (C schedule), and N
o. The other set values of the 1 stand and the set values of the other stand remain as the schedule A (see FIG. 1 (a)).

That is, the set values of the reduction amount and the tension of the No. 1 stand a are SA _a and TA _a of the A schedule, respectively, and the reduction amounts of the other stands, for example, the second stand b,
The set values of speed and tension are SA _b and V of A schedule, respectively.
A _b and TA _b . The speed change of the roll 2a due to the change of the speed set value is performed by the electric motor control device 6a via the electric motor 4a.

Next, when the transition start point X reaches the No. 1 stand a, only the set values of the reduction amount and the tension of the No. 1 stand a are SA _a and TA of the A schedule, respectively.
_a from the C schedule SC _a, change to TC _a, the set value of the other stand has been left A schedule (Fig. 1
(See (b)). After that, when the transition start point X reaches a predetermined position Y _mb (≠ Y _ma ) before the second stand b,
Only the speed setting value of No. 2 stand b is changed from VA _b of A schedule to VC _b of C schedule, and other setting values of No. 2 stand b and No. 3, 4, 5 stand c,
The set values of d and e are left as the A schedule (Fig. 1
(See (c)). The set value for No. 1 stand is still C schedule.

After that, when the transition start point X reaches the second stand b, the reduction amount, speed, and
The tension of the set value of the C schedule SC _a, VC _a, TC
_a from B schedules SB _a, VB _a, with respectively changed to TB _a, reduction of the second stand b, and tension set values, the A schedule SA _b, from TA _b of C schedule SC _b, TC _b Change to other No. 3, 4, 5
The respective set values of the stands c, d, and e are kept as the A schedule (see FIG. 1D).

Next, when the transition start point X reaches a predetermined position Y _mc (≠ Y _ma , Y _mb ) before the third stand c, N
o. Change only the speed setting value of 3 stand c from VA _{c of} A schedule to VC _c of C schedule (Fig. 2
(See (e)). After that, the transition start point X is the third stand c.
When the value reaches the second schedule b, the setting values of the second stand b are changed from the C schedule to the B schedule, and
The amount of reduction of the stand c and the set values of the tension are set from SA _c and TA _c of the A schedule to SC _c and TC _{c of the} C schedule.
Change to No. 4, 5 stands d and e, and the set values remain as A schedule (see FIG. 2 (f)).

The same steps as described above are repeated until each set value of each stand reaches the B schedule. That is, 1) When the transition start point X reaches a predetermined position Y _mi before the No. i stand, only the speed setting value of the No. i stand is changed from the A schedule to the C schedule, and 2) the above transition start When the point X reaches the No. i stand, the set values of the compression amount and tension of the No. i stand are changed from the A schedule to the C schedule and the No. i stand is changed.
The schedule of each set value of the i-1 stand is changed from the C schedule to the B schedule.

3) When the above steps (1) and (2) are repeated, the transition start point X finally reaches the No. 5 stand e, and each set value of the No. 2 to No. 4 stands. Are all B schedules, and the set values of No. 5 stand e are C schedules.

In general, the rolled material 1 is rolled by the No. 5 stand and then wound by a winder (not shown). Therefore, when the transition start point X reaches the above-mentioned winder, the No. 5 stand is reached. Each setting value of is changed from C schedule to B schedule.

When the setting values of all the stands are changed to the B schedule in this way, the load of the stand having the roll to be exchanged, for example, the second stand, is almost zero, and the work of the second stand is performed. The speed of the roll 2b is the speed of the work roll 2c of the preceding stand. At this time, the roll gap of the No. 2 stand whose rolls should be exchanged is opened by the hydraulic pressure reduction control device 11b through the hydraulic pressure reduction device 5b, and the No. 2 stand by the pass line control device 10b through the pass line adjustment device. By separating the lower surface of the work roll 2b from the rolled material 1, the upper and lower work rolls 2b are trimmed from the rolled material 1.

After that, the rotation of the roll of the No. 2 stand is stopped and the roll is replaced. A method for changing the rolls while the rolled material is passed through is well known, and this well known method may be used.

After the rolls have been replaced, the second stand after the rolls have been recombined is utilized to return from the 4-stand rolling to the 5-stand rolling. In order to return to this five-stand rolling, first, the roll gap of the roll-reassembled stand, for example, the second stand b is set by the hydraulic pressure reduction control device 11b so as to be the output side target thickness of the No. 1 stand a, and at the same time, the predetermined The pass line control device 10b sets the pass line setting value in consideration of the diameters of the upper work roll 2b and the upper reinforcement roll 3b. The speed setting value of the second stand b is the speed setting value of the No. 1 stand a. If the roll-replaced stand is the No. 1 stand, the roll gap of this No. 1 stand is set to the target plate thickness on the entry side of the No. 2 stand, and its speed setting value is No. .2 Be equal to the speed setting of the stand.

A point at a certain position on the rolled material 1 for starting the transition from the rolling schedule B to the rolling schedule A, that is, the transition starting point is Y, and the following steps a) and b) are set as the final stage stand. Repeat until each set value of the stands other than (No. 5 stand) becomes that of the A schedule.

A) When the transition start point Y reaches a predetermined position Z _mi before the No. i stand, only the speed set value of the No. i stand is changed from the B schedule to the C schedule.

B) When the transition start point Y reaches the No. i stand, the set values of the amount of reduction and the tension of the No. i stand are changed from the B schedule to the C schedule, and the No. i-1 stand is changed. Schedule C for each setting
Change from schedule to schedule A.

In this way, after each set value of the last stand becomes the C schedule and each set value of the other stands becomes the A schedule, when the transition start point Y reaches the winding machine, the last stand is set. The schedule of each set value of the stand is changed from the C schedule to the A schedule.

This completes the roll rearrangement.

As described above, according to this embodiment, the following effects can be obtained.

1) It is not necessary to cut the rolled material 1 when changing the rolls, the loss of the rolled material is eliminated, and the operation when changing the set value during running can be stably performed.

2) This eliminates the need for the operator to cut and remove the rolled material.

3) Since the target plate thickness can be obtained without using a stand during roll changing, it is not necessary to stop rolling by changing the roll, and the productivity can be greatly improved as compared with the conventional method.

Each motor 4i (i = a, b, ... E)
Has a large short-time overload capability, so there is no problem in overload operation at the time of roll change described above.

[0032]

According to the present invention, the productivity can be improved as much as possible without sacrificing the rolled material.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an operation of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of the present invention.

FIG. 3 is a block diagram showing the configuration of a specific example of an apparatus for performing the method of the present invention.

Claims (1)

[Claims] 1. A first to nth rolling mills arranged in tandem, and a winder for winding the rolled material rolled by the nth rolling mill which is the final rolling mill. In the rolling facility, a rolling schedule that uses the n rolling mills so that the exit-side rolling thickness of the rolling mill at the final stage becomes a predetermined rolling thickness is the first schedule, and has work rolls to be replaced. A rolling schedule in which n-1 rolling mills other than the rolling mills are used so that the exit side plate thickness of the rolling mill at the final stage becomes the predetermined plate thickness is defined as the second schedule, and the first schedule and the second schedule. The third schedule is an intermediate schedule of the above schedule, and the point at the position of the rolled material for starting the transition from the first schedule to the second schedule is the first start point, and the second schedule From the first suke When the point at a certain position of the rolled material for starting the transition to the joule is set as the second starting point: 1) The first position is set at a predetermined position before the i-th (i = 1, ..., N) rolling mill. When the start point of the rolling mill reaches the first rolling speed setting value of the i-th rolling mill from the first schedule to the third schedule, 2) When the rolling mill reaches the rolling mill, the reduction amount and tension set values of the i-th rolling mill are set to the first rolling amount.
Second step of changing each set value of the (i-1) th rolling mill from the third schedule to the second schedule while changing the schedule of No. 1 to the third schedule, and 3) the nth rolling mill. After repeating the first and second steps until each set value of No. 3 becomes the third schedule, each set value of the nth rolling mill is changed when the first start point reaches the winder. The third step of changing to the second schedule, and 4) cutting the rolling mill having the work rolls to be exchanged from the rolled material, exchanging the work rolls, and after the exchange, the roll gap of the rolling mill. And a fourth step of setting the speed setting to a predetermined value, 5) When the second start point reaches a predetermined position before the i-th rolling mill, only the speed setting value of the i-th rolling mill is set. From the second schedule to the third 5) the change to a tool, and 6) when the second starting point reaches the i-th rolling mill, the rolling reduction amount and the tension set value of the i-th rolling mill are changed from the second schedule to the third schedule. 6th step of changing each set value of the i-1th rolling mill from the 3rd schedule to the 1st schedule while changing to the schedule, and 7) each set value of the nth rolling mill is set to the 3rd After repeating the fifth and sixth steps until the schedule becomes, each set value of the nth rolling mill is changed to the first schedule when the second starting point reaches the winder. A roll rearrangement method comprising: a seventh step.