JP2721716B2 - Reversible cold rolling method and equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reversible cold rolling method and equipment, and more particularly to a reversible cold rolling method and equipment suitable for rolling special steel such as stainless steel. .

[Conventional technology]

Conventional cold-rolling equipment for metal strips is limited to one-stand unidirectional rolling, one-stand reversible rolling, or one-way rolling of a tandem mill. In the case of ordinary steel sheets, tandem mills for mass production are the mainstream, and the necessary thickness reduction is usually obtained in 4 to 6 stands, and the equipment cost and production volume are balanced. However, when rolling a stainless steel plate, the required thickness is usually reduced by 6 if a tandem mill is used.
Since ~ 8 passes are required, 6 ~ 8 stands are required, and the investment scale becomes too large. For this reason, the number of stainless steel cold rolling equipment is expected to be several hundred in the world, both large and small. However, there is only one tandem mill with four stands, and all others have one stand. Reversible rolling equipment.

In addition, an example in which the stainless steel cold rolling equipment is constituted by a tandem mill is described in, for example, "118th / 119th Nishiyama Memorial Technical Course-Recent Advances in Stainless Steel Manufacturing Technology" and the like. In the case of a single reversible rolling mill with one stand, various actual machines can be seen as products.

[Problems to be solved by the invention]

However, when a stainless steel plate is rolled by this conventional reversible cold rolling equipment, there are the following problems.

(1) In the reversible type, two winding / unwinding machines are installed before and after the rolling stand, and installation of these winding / unwinding machines requires large equipment costs. Particularly in the case of stainless steel rolling, the strip tension becomes strong, so that two electric motors for the winding / unwinding machine having output equal to or higher than that of the main motor for the rolling mill are required. Furthermore, if the rolling speed is to be increased in order to increase production, the electric motor for the winding / unwinding machine must increase the power in proportion to the rolling speed. Expenses are expensive. That is, an increase in the amount of rolling per equipment cost cannot be expected, and it is difficult to improve production efficiency.

(2) Since stainless steel sheets have severe surface quality,
Paper is inserted between the layers of the strip wound on the unwinding machine to prevent scratching. The paper is wound up and unwound in each rolling pass, and is disposable. Cost is a cause of high rolling costs.

An object of the present invention is to provide a reversible cold rolling method and a facility capable of increasing a rolling amount per facility cost and reducing a rolling cost.

[Means for solving the problem]

According to the present invention, for the above purpose, in a reversible cold rolling method using at least first and second two rolling stands, a service that does not roll at least one of the leading end and the trailing end of the rolling strip. Installing a rolling coil connected to a tail, unwinding the rolling coil and performing rolling at the first and second rolling stands, and a joint portion of the service tail with a rolling strip is formed of a first rolling stand. Releasing the rolling reduction of the first rolling stand when it reaches the entry side, wherein the second rolling stand continues rolling until the joint is near the entry side of the second rolling stand, Stopping the driving, then performing the reverse pass by reversing the roll driving direction of the second rolling stand, after the joining portion has come out on the reverse pass of the first rolling stand. Applying a roll pressure of the first rolling stand, it resumes reversible cold rolling method of rolling of the first rolling stand is provided.

Here, preferably, a looper means is provided between the first and second rolling stands, and a strip is supplied to the second rolling stand by the looper means when the roll pressure of the first rolling stand is released. When the rolling pressure of the first rolling stand is reduced, the looper means accumulates the strips sent from the second rolling stand in a reverse pass.

The drive of the winding / unwinding device adjacent to the first rolling stand is stopped when the rolling reduction of the first rolling stand is released and at the time of rolling down the roll, and at least during that time, the second
The supply of the strips to the rolling stand and the accumulation of the strips sent out in the reverse pass may be performed by looper means provided between the first and second rolling stands. At this time, preferably, the roll driving of the first rolling stand is stopped at the time of releasing the rolling reduction of the first rolling stand and at the time of rolling down.

According to the present invention, in order to achieve the above object, at least first and second rolling stands, and first and second rolling stands installed before and after the first and second rolling stands. There is provided a reversible cold rolling facility comprising a take-up / unwinding device and a looper means installed between the first and second rolling stands and capable of accumulating and discharging a rolled strip.

[Action]

In the reversible cold rolling method and equipment of the present invention configured as described above, since reversible cold rolling is performed using at least two rolling stands, at least two reversing cold rolling operations are performed by one pass and one winding operation. One pass rolling is possible,
In the case of two rolling stands, the rolling efficiency is doubled. On the other hand, the number of motors for driving the rolling mill and for the winding / unwinding machine is reduced from the conventional three to only four. The rolling amount per unit, that is, the production efficiency becomes 1.5 times. Also,
Since two pass rollings are performed in one winding operation, the strip becomes thinner than before, and the output of the winding / unwinding machine can be reduced.

Further, since two pass rollings are possible, the number of windings is at least halved, the amount of paper used is halved, and the rolling cost is reduced.

In the reversible cold rolling method of the present invention,
In the pass rolling from the rolling stand to the second rolling stand, the rolling of the second rolling stand is continued until the joining portion between the rolling strip and the service tail is near the entry side of the second rolling stand. The joint is the first
The rolling unrolled portion of the rolling coil can be extremely shortened by applying the roll reduction of the first rolling stand after exiting the exit side of the rolling stand, so that the unrolled portion of the rolling coil can be extremely shortened. Improvement can be realized at the same time.

A looper means is provided between the first and second rolling stands, and the roll is released and accumulated by the looper means when the roll of the first rolling stand is released, and when the roll is released, the stripper is released. In addition, it is possible to absorb the fluctuation of the tension at the time of rolling down the roll, thereby enabling stable rolling.

Also, by installing a looper means between the first and second rolling stands, the drive of the winding / unwinding device and the first rolling stand can be performed when the rolling reduction of the first rolling stand is released and when the rolling is reduced. Can be stopped, so that the release of the roll pressure during rolling and the deterioration of the plate shape due to the roll pressure can be prevented.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a reversible cold rolling facility according to one embodiment of the present invention. In this embodiment, two rolling stands are used, but three or more rolling stands may be used. .

In FIG. 1, reference numerals 1 and 2 denote two rolling stands of a No. 1 stand and a No. 2 stand, respectively. Before and after the two rolling stands 1 and 2, winding of a strip 3 of rolling coils 3A and 3B is performed. An inlet reel 4 and an outlet reel 5 for taking and unwinding are installed, and two rolling stands 1 and 2
A looper device 6 between which the strip 3 can be accumulated and discharged.
Is installed.

Non-rolled service tails 7 (see FIGS. 2 and 3) are connected to both ends of the strip 4 forming the rolling coils 3A and 3B, and the service tails 7 are provided on the entry reel 4 and the exit reel 5, respectively. It is wound on the innermost layer of the rolling coils 3A and 3B. The direction of the strip 3 of the rolled coil 3A unwound from the entry side reel 4 is changed by the deflorer 8, and rolling is performed in the No. 1 stand 1. N
In the present embodiment, the type of the stand 1 is a six-high rolling mill in which the roll 1a is opened and closed, that is, the roll reduction is released or the roll reduction is performed by the hydraulic reduction device 9. However, this may be a cluster mill typified by a Sendzimer mill. However, in order to perform the rapid opening and closing of the roll 1a required when the strip 3 and the service tail 7 pass through the joint when the rolling is stopped, it is preferable that the rolling-down device 9 is of a hydraulic type.

The rolled strip 3 passed through the No. 1 stand 1 passes through a looper device 6. Although there are various types of the looper device 6, an electric type, a multi-line type, or the like may be used as long as the strip 3 can be accumulated and released in a state where tension is applied to the strip 3. In this embodiment, a hydraulic cylinder 10 is used as an actuator, and the roller 11 is moved up and down by driving the hydraulic cylinder 10 to accumulate and discharge the strip 3. A tension meter roller 12 and a roller 13 are provided before and after the roller 11 for changing directions. It is preferable that the number of rollers in contact with the rolled strip 3 is as small as possible. In this embodiment, one roller 12 also serves as a tension meter roller and is used as a detector of strip tension between the stands 1 and 2.

The strip 3 is further rolled at the No. 2 stand 2, the direction of the strip 3 is changed by the deflorer 15, and the strip 3 is wound around the outlet reel 5. The No. 2 stand 2 is configured similarly to the No. 1 stand 1 and includes a hydraulic pressure reducing device 14 for opening and closing the roll 2a.

When the first rolling pass from No. 1 stand 1 to No. 2 stand 2 is completed, a reverse pass rolling from No. 2 stand 2 to No. 1 stand 1 is performed. After being performed, the entire strip, including the service tail 7, is preferably coiled on the outgoing reel 5 or the incoming reel 4.
Wound on 3B or 3A and paid out.

Although the loading of the material coil may be performed by the entrance reel 4,
In order to pass the next material coil during the payout process of the coil 3A by the entry reel 4, and to improve the operation rate,
No.1 stand 1 with special payoff reel 16 as shown
It is preferable to install as close as possible.

Note that the roller of the looper device 6 is used when passing the coil tip.
11 is sufficiently raised so that a sufficient gap is formed between the lower surface thereof and the upper surfaces of the tension meter roller 12 and the roller 13 so that the coil tip can pass without being bent or stuck. is required.

Next, a rolling method according to an embodiment of the present invention using the reversible cold rolling equipment of FIG. 1 will be described with reference to FIGS. 2 and 3. FIG.

First, as shown in FIG. 2 (a), the strip 3 of the coil 3A is unwound from the entrance reel 4, and the No. 1 stand 1 and
Roll the right pass at No.2 stand 2. At this time, the roll 11 of the looper device 6 is held at the illustrated raised position.
Rolling of right pass progresses, strip 3 and service tail 7
When the junction with the roller reaches the vicinity where it is unwound from the entry side reel 4, the hydraulic cylinder 10 (see FIG. 1) of the looper device 6 is driven to lower the roll 11 as shown in FIG. 2 (b). When the joint starts and reaches the vicinity of the entry side of the No. 1 stand 1, the roll 11 of the looper device 6 as shown in FIG.
Complete the descent.

No. 1 stand 1 roll is the joint of service tail 7
When reaching the entrance point 1a, as shown in FIG. 2 (d),
The roll drive of the No. 1 stand 1 is stopped, the unwinding of the entry side reel 4 is stopped at the same time, and the roll pressure of the No. 1 stand 1 is rapidly released. At the same time, the looper device 6
The hydraulic cylinder 10 is driven to start raising the roll 11. That is, at this time, the looper device 6
The strip 3 is supplied to the No. 2 stand 2 which continues rolling by discharging the strip 3 while controlling the tension.

Thereafter, when the gap between the rolls 1a of the No. 1 stand 1 is opened until the joining portion of the service tail 7 and the service tail 7 can pass without being rolled, as shown in FIG. Unwinding is resumed, and the service tail 7 is sent out from the entry side reel 4. At this time, the roll 1a of the No. 1 stand 1
It is desirable to keep the wheel idle so as not to damage it. At this time, the looper device 6 fixes the position of the roll 11, and controls the tension of the strip 3 supplied to the No. 2 stand 2 by controlling the drive of the entry reel 4.

When the joint of the service tail 7 reaches the entry side of the No. 2 stand 2, as shown in FIG.
Also stop and stop the line temporarily.

Next, the direction of the pass is reversed, and rolling starts in the left pass as shown in FIG. 3 (a). At this time, the outgoing reel 4 applies the tension of the outflow of the No. 2 stand 2. The roller 11 of the looper device 6 remains fixed at the raised position. The joint of the service tail 7 passes through the No. 1 stand 1 and FIG. 3 (b)
When the roll 1a exits as shown in FIG. 6, the entry reel 4 stops. At the same time, the lowering of the rollers 11 of the looper device 6 is started, and the strips 3 sent out from the No. 2 stand 2 are accumulated while controlling the tension. At this time, the rolling of the roll 1a of the No. 1 stand 1 is started. No.1 stand 1
Is completed, the entry side reel 4 and the No. 1 stand 1 are driven as shown in FIG. 3 (c).
At this time, at the same time, the roller 11 of the looper device 6 is raised again, and the accumulated strip is gradually discharged to prepare for the next right pass rolling. When the roller 11 returns to the initial raised position as shown in FIG.

Next, effects of the rolling equipment and the rolling method according to the present embodiment will be described.

First, the basis of the above-mentioned rolling equipment and rolling method is that the number of rolling stands of the reversible cold rolling equipment is two. As a result, two passes can be rolled by one pass and one winding operation, and the rolling efficiency is doubled.
On the other hand, when the cost of equipment is simplified for comparison with motors, in the conventional one-stand reversible type, one motor (mill motor) for driving the rolling mill and two motors (reel motor) for the entry and exit reels are used. In this embodiment, the number of motors for driving the rolling mill is two, and the number of motors for the entrance reel and the exit reel is two. That is, while the rolling amount index per facility cost is 1/3 in the past, 2/4 = 1/2 in the present embodiment, and the rolling amount per facility cost, that is, the rolling efficiency is 1.5 times. Become. In this embodiment, two pass rollings are performed, and the thickness of the strip becomes thinner than before, so that the motor for the winding / unwinding machine can have a smaller output than before, and further reduction in equipment cost can be achieved. It is possible.

In addition, since at least two pass rolling is possible by one winding operation, the number of windings is reduced by at least half,
The amount of paper used is halved, and the rolling cost can be reduced.

Further, according to the rolling method of the present embodiment, the following effects can be further obtained.

The basic advantages of having two rolling stands in a reversible inter-rolling plant are as described above. However, despite these advantages, a two-stand reversible rolling method has not been put to practical use. The reason is that it is extremely difficult to perform the rolling itself by the conventional rolling method. Hereinafter, this will be described with reference to FIG.

When stainless steel rolling is performed in a reversible manner, the leading and trailing ends of the rolling coil are not separated from the reel, so that an unrolled portion remains, and only that portion does not become a product. Since expensive materials would increase the cost, as described above, it is common to join a non-rolling substitute strip called the service tail 7 to the product coil, split this from the coil after rolling, and use it repeatedly. It is.

FIG. 4 shows a state where reversible rolling is performed by a conventional rolling method using a two-stand reversible rolling facility. In this conventional method, when the service tail 7 comes to the entrance side of the No. 1 stand 1, rolling is stopped, and the process proceeds to a reverse pass. At this time, the following problem occurs.

(1) Assuming that the first rolling is completed in FIG. 4 (a), the strip portion on the left side of the No. 1 stand 1 has the thickness h0 of the raw material, and the No. 1 stand 1 and the No. 2 stand 2
In the period L, since the sheet is rolled once, the plate thickness becomes h1, and since the right side of the No. 2 stand 2 is rolled twice, it becomes h2. Next, as shown in FIG. 4 (B), when the rolling in the reverse pass proceeds a little, there is a portion of the plate thickness h2 which has been rolled twice on the right side of the No. 2 stand 2, and the right portion between the L portions Is rolled three times to a sheet thickness of h3. However, No.1
Since the left side of the stand 1 is rolled only twice, it has a thickness of h2 ', which is obtained by further rolling the thickness of h3.
(Not shown). Naturally, it is impossible to reduce the thickness from h1 to h4 by one rolling. Therefore, the strip between L is off-gauge, ie, wasted.

(2) Even if the strip between L can be made to be on-gauge by any method, the roll mark of the No. 2 stand 2 at the time of stoppage is a defective portion due to the strip.

(3) During the reverse pass rolling, the thickness of the entrance side of No. 1 stand 1 changes suddenly.
Variations in the rolling load of one stand 1 induce disturbances in the plate shape and the like, which increases the risk of plate breakage and squeezing, which is a problem as a practical machine.

The rolling method of the present embodiment solves all the disadvantages described above and makes full use of the features of two stands, that is, reversible tandem rolling.

That is, in the present embodiment, in the first rolling pass, as shown in FIG. 2 (f), the joining of the service tail 7 continues rolling without stopping to the entrance side of the No. 2 stand 2, and at this time, As shown in FIGS. 2 (d) and 2 (e), the No. 1 stand 1 controls the roll gap so that the service tail 7 is not rolled, and the tension fluctuation between stands caused by this control is absorbed by the looper device 6. . In the reverse pass rolling, as shown in FIG. 3 (b), after the joining portion of the service tail 7 exits the No. 1 stand 1, the rolling reduction of the No. 1 stand 1 is applied. The accompanying tension fluctuation between the stands is similarly absorbed by the looper device 6.

Therefore, according to the present embodiment, it is possible to perform the rolling up to just before the joint of the service tail 7,
The unrolled portion of the rolled coil can be extremely short, and the yield can be improved.

In addition, the installation of the looper device 6 can absorb the fluctuation of the tension at the time of releasing the roll and reducing the tension at the time of the roll reduction, so that stable rolling can be performed.

In this embodiment, the drive of the entry side reel 4 is stopped as shown in FIGS. 2 (d) and 3 (b) when the roll pressure of the No. 1 stand 1 is released and when the roll pressure is reduced. As described above, since the roll drive of the No. 1 stand is stopped, release of roll reduction during rolling and deterioration of the plate shape due to roll reduction can be prevented, and excellent rolling quality can be provided.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the rolling amount per equipment cost can be increased and production efficiency can be improved, and also the rolling cost can be reduced because the amount of used paper is reduced. Further, since the unrolled portion of the rolled coil can be extremely short, it is possible to simultaneously improve the production efficiency and the yield.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a reversible cold rolling equipment according to one embodiment of the present invention, and FIGS. 2 (a) to (f) show the first reversible cold rolling method according to one embodiment of the present invention. FIGS. 3 (a) to 3 (d) are views showing each step of reverse pass rolling, and FIGS. 4 (a) and 4 (b) are views showing a conventional rolling method. And FIG. DESCRIPTION OF SYMBOLS 1 ... No.1 stand 2 ... No.2 stand 3 ... Rolled strip 4 ... Inlet reel (take-up / unwinding device) 5 ... Outlet reel (take-up / unwinding device) 6 Looper device 7 Service tail

Claims (5)

(57) [Claims] In a reversible cold rolling method using at least first and second two rolling stands, a rolling coil in which a service tail that is not rolled is connected to at least one of a leading end and a trailing end of a rolling strip. Unwinding the rolling coil and performing rolling at the first and second rolling stands, and the joining portion of the service tail with the rolled strip is the first.
Releasing the roll reduction of the first rolling stand when it reaches the entry side of the rolling stand, wherein the second rolling stand continues rolling until the joint is near the entry side of the second rolling stand And then stopping the roll drive, then performing the reverse pass by reversing the roll drive direction of the second rolling stand, and performing the reverse pass after the joining portion comes out on the output side in the reverse pass of the first rolling stand. A reversible cold rolling method, characterized in that the rolling reduction of the first rolling stand is applied and rolling by the first rolling stand is restarted. 2. The reversible cold rolling method according to claim 1, wherein a looper means is provided between said first and second rolling stands, and said looper means is released when said first rolling stand is released from rolling pressure. And supplying the strip to the second rolling stand, and accumulating the strip sent out from the second rolling stand in a reverse pass by the looper means when the roll of the first rolling stand is rolled down. Rolling method. 3. The reversible cold rolling method according to claim 1, wherein the first rolling stand is adjacent to the first rolling stand when the rolling reduction is released and when the rolling is reduced.
Looper means for stopping the operation of the unwinding device, and at least meanwhile, supplying the strip to the second rolling stand and accumulating the strip fed in the reverse pass between the first and second rolling stands. And a reversible cold rolling method. 4. The reversible cold rolling method according to claim 3, wherein the roll drive of the first rolling stand is stopped when the rolling reduction of the first rolling stand is released and when the rolling pressure is reduced. Reversible cold rolling method. 5. At least first and second rolling stands, first and second winding / unwinding devices installed before and after said first and second rolling stands, and said first and second rolling stands.
And a looper means installed between the second rolling stand and capable of accumulating and discharging the rolled strip.