JPH0777644B2 - Tandem cold rolling method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tandem cold rolling method for continuously rolling metal strips having different surface textures.

[Conventional technology]

In the conventional cold rolling method, when producing strips having different surface textures, a rolling unit of several hundred tons to several thousand tons called a rolling schedule is provided, and the required surface texture is obtained by rearranging the rolling rolls for each rolling unit. Had rolled the strip.

Regarding the reassembling work of this rolling roll,
There is a method as described in the publication.

In such a conventional method, when it is desired to manufacture strips having different surface textures in a short time in order to set a rolling schedule, the rolls must be changed. Therefore, rolling was interrupted during the reassembling work, and the waiting time inevitably became long in the manufacturing process. Also, in the event of an urgent need to produce a strip of a given surface texture, the default rolling unit must be split unless the required surface texture fits the rolling unit currently in operation. However, the rolling roll reassembling time increased and the rolling roll usage efficiency decreased.

As a method for alleviating such a problem, the conventional method has been to reduce the time required for roll replacement as much as possible. For example, speeding up the operating speed of equipment, adoption of a recombination method with a plate instead of the reclamation method without a plate (saving time for cutting and reconnecting a plate), detachment of a rolling mill while continuing rolling (Japanese Patent Publication No. 53- See No. 34582).

[Problems to be solved by the invention]

However, in such a conventional method, the time required for roll reshuffling is reduced, but if the rolling unit is made extremely small, the number of rolls used is significantly increased, and even if it is reduced, it is not a long time. Therefore, the fundamental solution to the problem that the production efficiency decreases unless a certain rolling unit is observed cannot be expected.

Therefore, the present invention does not significantly reduce the operating rate of the rolling mill and the efficiency of use of the rolling rolls even when the rolling unit is made extremely small, thereby realizing the frequent change of the product surface in the small rolling unit. To aim.

[Means for solving problems]

In order to achieve this object, the tandem cold rolling method of the first invention of the present application provides a final rolling stand at a surface texture changing point when continuously stripping strips having different surface textures by a tandem cold rolling mill. With the rolling rolls in the open state, the required amount of rolling is performed with the rolling rolls of the stand in front of the final rolling stand in this state, during which the rolling rolls of the final rolling stand are recombined with rolling rolls having different surface textures, and then At the point where the surface texture is changed, the rolling roll of the final rolling stand is transferred to the used state and rolling is performed, and this procedure is repeated to finally change the rolling state to the original rolling roll.

Further, the tandem cold rolling method of the second invention of the present application, when continuously cold-rolling strips having different surface textures by a tandem cold rolling mill, at the point of changing the surface texture, rolling of the stand before the final stand is performed. The rolling roll of the final rolling stand having a surface different from the roll is opened, and in this state, rolling is performed by the rolling roll of the stand before the final rolling stand, and the rolling roll of the final rolling stand at the next surface texture change point. It is characterized by shifting to the use state.

In any of the first and second aspects of the present invention, the operation of bringing the rolling roll into the open state or the use state is performed during rolling without stopping the rolling mill, thereby shortening the stop time of the final tund and rolling. The efficiency of can be improved.

In addition, in the present invention, the “used state” refers to a state in which rolling is actually performed using a rolling roll.

[Action]

FIG. 1 shows a reassembling procedure according to the first invention of the present application in the case where a plurality of roll reassembling is continued as the rolling progresses for each rolling unit.

In FIG. 1, the rolling roll of the final rolling stand is opened in step 1, and while rolling in this state, the rolling roll of the final rolling stand is used in combination with the rolling roll having different surface texture in steps 3 and 4. After performing the predetermined amount of rolling shown in step 5 in the state, the rolling state of the original rolling roll held on the roll changing device is changed again in steps 6 to 8. By doing so, the roll rearrangement procedure becomes a little complicated, but it is possible to improve the product making function of the tandem rolling mill.

Since the surface texture of the cold-rolled strip is usually determined by the surface texture of the rolling roll of the final stand, if only the rolling roll of the final stand is changed as in the present invention, the rolling rolls of other rolling stands are It is possible to change the surface texture of the strip while remaining the same.

By the way, when rolling without using the rolling roll of the final stand, the surface texture of the strip is determined by the surface texture of the rolling roll of the stand immediately before,
From the standpoint of rolling performance, bright rolls that are finished to be smooth by grinding are usually used as the rolls of the stands other than the final stand, so that the strip has a bright surface finish. Therefore, in the rolling method of the present invention, a bright finish strip is rolled between rolling units that require different surface textures, but one of the adjacent rolling units is bright finish as in the case of FIG. If you do not cause problems. Further, in such a case, a method of inserting a strip that requires bright finish between rolling units and opening and changing the last stand rolling roll in the rolling can be adopted.

The roll changing procedure in the first method of the present invention is the same as the roll changing procedure in the conventional method in that roll changing is performed for each rolling unit. It does not have the following features. That is, the amount of rolling by the same roll is increased because the roll is reused, and the use efficiency of the roll does not decrease even if the rolling unit is reduced for different surface textures. Further, since the rolling rolls in the final stand are exchanged during the rolling of the bright finish material, even if the rolling unit is reduced in order to make different surface textures, there is no increase in the downtime of the rolling mill due to the exchange of the rolling rolls.

In addition, in the method of the first invention of the present application, when the roll is released or returned to the use state, for example, Japanese Patent Publication No. 53-34582.
By using the plate thickness changing method between running shown in the publication, the procedure of FIG. 1 can be performed without stopping the rolling mill, and the above effect can be further increased.

The method of the second invention of the present application is to achieve a similar effect with a smaller number of steps, although there are some restrictions in application, with some modifications made to the method of the first invention. The procedure is shown in FIG. In Fig. 2, the rough surface roll of the final rolling stand is opened in step 2, and the material rolled in this state is rolled by the rolling roll (bright surface) of the rolling stand immediately before the final stand. Bright finish. After the rolling of the bright finish material is completed, the rough surface roll of the final stand is returned by step 4, and the rough surface finish material rolling is performed.

The characteristic of the method of the second invention is that, under the condition that the rolling roll is changed in the conventional method, the operational flexibility of the tandem rolling mill is utilized to avoid the roll change, The final stand rolls are turned on and off, and the pass schedule of the tandem mill is changed accordingly or according to the material while the finishing surface is being changed according to the use. By doing so, the so-called degree of freedom in operation of the tandem rolling mill is greatly improved, and it becomes possible to operate the rolling mill with an excellent product making function.

When using the above method, the bright finish material is rolled with one less mill stand. Therefore, the rolling capacity of the tandem rolling mill (input side plate thickness /
It is possible to perform rolling only within a range of rolling capacity E ₁ which is smaller than E ₀ and not E ₀ . Therefore, it is necessary to plan a rolling unit consisting only of the material rolled in the E ₁ range in advance. In the cold rolling process, the elongation ratio (inlet plate thickness / outlet plate thickness) e of the material is in a wide range of 2 to 10, and it is possible to plan the rolling unit as described above. Of course, it is necessary to roll the material satisfying the condition of E ≧ e> E ₁ within a long period of time. Therefore, not all the rolled materials can be rolled using the method of the second invention of the present application. It is possible to achieve sufficient effects by appropriately planning the unit.

〔Example〕

An apparatus for carrying out the method of the present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 3 is a drawing showing a state in which the rolling rolls of the final stand are reassembled. In the figure, 1 is a rolled material, and 7 to 10 are first to fourth stands, respectively. In the figure, the rolling rolls 3A, 3B of the final stand are supported by the chocks 4A, 4B having wheels 5A, 5B, and in the rearranged state, the chocks 4A, 4B are on rails 6A, 6B. Chock 4A, 4B
Are paired up and down, but the upper and lower chocks 4A, 4B are not connected to each other, so they can run on different rails and be pulled out of the rolling mill. At this time, since there is no interference with the rolled material 1, it is possible to continue rolling with the other rolling stands 7 to 10 even during the reassembling of the rolling rolls 3A and 3B. In FIG. 3, 2A and 2B are auxiliary rolls of the final stand.

In order to apply the method of the present invention, it is necessary to be a rolling mill equipped with a roll changing device having such characteristics, a so-called roll changing device with a plate.

In the rolling method of the present invention, it is necessary to perform rolling without using the rolling roll of the final stand, for which the rolling mill drive electric system is designed to be drivable with the final stand separated. Must be However, it is easy to design in this way or add such a function.

Next, FIG. 4 shows a final rolling stand and its reassembling device, FIG. 4 (a) is a front view, and FIG. 4 (b) is a schematic plan view. In these drawings, 11 is a final rolling stand, and 12 is a driving device for the rolling rolls 3A and 3B. On the side of the final rolling stand 11, a rolling roll changing carriage 14 is arranged so as to be able to move forward and backward by a carriage traveling cylinder 16, and a rolling roll changing frame 15 provided with a rail is provided on the same carriage 14. Has been. Then, the frame 15 is equipped with standby rolling rolls 13A and 13B.

In FIG. 4, when the rolling rolls 3A and 3B are to be replaced, the upper and lower rolls 3A and 3B are separately run on the rails on the frame 15 and pulled out on the reassembling carriage 14, and the horizontal direction is applied at that position. After performing a shift operation to replace the other rolling rolls 13A and 13B, the rolling rolls 13A and 13B are inserted again into the housing of the rolling stand 11. Further, explaining with the plan view of FIG. 2B, the rolling rolls 3A, 3A pulled out from the rolling stand 11 are shown.
B (hereinafter referred to as roll A) is the frame 1 on the reassembling carriage 14
It is placed in the first position a ₁ of 5. Next, by the shift operation for one position, the roll A moves to the first auxiliary position a ₄ , but at the same time, another rolling roll 13 placed at the second position a ₂
A, 13B (hereinafter referred to as roll B) moves to the first position a ₁ ,
It is ready to be inserted and is inserted. In the next roll change after the material to be rolled by the rolling roll B is finished, the rolling roll B is retracted by the same operation as described above,
The rolling roll A is inserted again. Frame on rearrangement trolley 14
The third position a ₃ of 15 is used as a preparation position for an unused rolling roll. In the event that a roll change suddenly becomes necessary due to a rolling accident, a shift operation is performed so that the spare roll prepared in advance at the third position a ₃ comes to the first position a ₁ , and then the rolling stand 11 To insert.

The apparatus shown in FIG. 4 makes it possible to hold both the rolls to be reused (either the rolling rolls A or B) and the spare rolls on the reassembling device, which is an indispensable spare in the rolling operation. It is possible to more effectively carry out the method of the first invention of the present application while keeping the roll in the ready state.

In the case of a manufacturing schedule in which rolling units of bright finish and rough surface finish are alternately processed, the conventional method, the rolling units are subdivided, and the first method or the second method of the present invention is applied. An example is shown in the table. In the table, according to the conventional method, the rolling rolls are replaced when the surface roughness causes a limit (1000 ton processing) or when the rolling unit is changed.

Next, when the first method of the present invention is carried out, the number of roll changes is significantly increased because the rolling unit is small, but the stop time per roll is shortened. Decreases.

Next, when the second method of the present invention is carried out, the rolling rolls of the final stand are not used in most cases in the case of bright finish rolling, and the number of reassembling of the final stand rolling rolls is rough. It is characterized by the fact that the surface roll roughens only to the limit, and it greatly reduces, and the total stop time also becomes small.

(Effects of the Invention) As described above, in the present invention, when continuously cold-rolling strips having different surface properties by the tandem cold rolling mill, the rolling roll of the final rolling stand at the surface property change point is used. Perform the required amount of rolling in an open state, during which the rolling rolls of the final rolling stand are replaced with rolling rolls having different surface textures, or the rolling rolls are left in a standby state, and the next surface texture change point Therefore, the original rolling roll is used and rolled. Therefore, a strip having a desired surface texture can be continuously rolled using the same rolling mill. Therefore, it is possible to carry out production under a production schedule in which the rolling unit is made smaller without lowering the usage efficiency of the rolling mill, and the production period increase due to waiting for the rolling unit is reduced by 1/10 (2500 Tons / 250 tons).

Further, by performing the operation of bringing the rolling rolls into the open state or the used state during rolling without stopping the rolling mill, the down time of the rolling stand can be further reduced, and the effect of application is further enhanced.

Incidentally, in the conventional method, the rolling roll was pulled out of the rolling mill after being used up to the limit of wear or fatigue of the surface and then ground, whereas by applying the present invention, even during roll rearrangement. By continuing the rolling and substantially avoiding the loss due to the roll changing time, there is an effect that the roll changing can be frequently performed and the same roll can be reused several times.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a roll reassembling method of a first invention of the present application, FIG. 2 is an explanatory diagram showing a roll reassembling method of a second invention of the present application, and FIG. 3 is a method of implementing the present invention. FIG. 4 is a view showing the state of rearrangement of the rolling rolls of the final stand of the tandem rolling mill in the above apparatus, and FIG. 4 is a drawing showing the configuration of the final rolling stand of the tandem rolling mill in the apparatus for carrying out the method of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Bunichiro Chikazawa 1-1-1, Edamitsu, Hachiman-ku, Kitakyushu, Kitakyushu, Fukuoka Inside Nippon Steel & Co., Ltd. Hachiman Works (72) Inventor, Akira Ishihara, Hachiman, Kitakyushu, Fukuoka 1-1-1, Emitsu, Higashi-ku, Nippon Steel Co., Ltd.

Claims (4)

[Claims] 1. When the strips having different surface properties are continuously cold-rolled by a tandem cold rolling mill, the rolling rolls of the final rolling stand are opened at a point where the surface properties are changed, and in this state, before the final rolling stand. The required amount of rolling is performed with the rolling rolls of the stand, during which the rolling rolls of the final rolling stand are recombined with rolling rolls having different surface textures, and the rolling rolls of the final rolling stand are used at the next surface texture change point. And rolling it,
A tandem cold rolling method characterized by repeating this procedure and finally changing to the rolling state of the original rolling roll. 2. The tandem cold rolling method according to claim 1, wherein the operation of bringing the rolling roll into the open state or the used state is performed during rolling without stopping the rolling mill. 3. A tandem cold rolling mill continuously cold-rolls strips having different surface textures, and at the time of changing the surface textures, a final rolling stand having a surface different from that of the rolling roll of the stand before the final stand. It is characterized in that the rolling roll is in an open state, rolling is performed by the rolling roll of the stand before the final rolling stand in this state, and the rolling roll of the final rolling stand is moved to the use state at the next surface texture change point. Tandem cold rolling method. 4. The tandem cold rolling method according to claim 3, wherein the operation of bringing the rolling roll into an open state or a used state is performed during rolling without stopping the rolling mill.