JP3422930B2 - Adjusting method for rolling zero point of sheet rolling mill - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work for adjusting a zero point of a rolling position of a plate rolling machine, which is a preparatory work for rolling a metal plate material such as steel.

[0002]

2. Description of the Related Art One of the important problems in the rolling operation of a metal sheet is to make the elongation rate of the rolled material equal on the working side and the driving side. In the following, the working side and the driving side will be referred to as left and right for the sake of simplicity. If the elongations are not uniform on the left and right, not only the planar shape and dimensional accuracy of the rolled material such as the camber and the plate thickness wedge may be inferior, but also the passing problem such as meandering and tail drawing may occur.

As an operating means for equalizing the left and right elongations, a left-right difference in the rolling position of the rolling mill, that is, a rolling leveling operation is used. Usually, the operation of the rolling leveling, both before the rolling and during the rolling, is almost always done by the operator while carefully observing the rolling operation. It cannot be said that the trouble of passing the strip is sufficiently controlled.

To solve the above-mentioned problem, Japanese Patent Publication No. 58-51771 discloses a technique for performing reduction leveling control based on the ratio of the load cell load of the rolling mill to the sum of the left and right differences.

Further, Japanese Patent Laid-Open No. 59-191510 discloses a technique for operating the reduction leveling by directly detecting the deviation of the rolled material on the rolling mill entrance side, that is, the amount of meandering.

[0006] All of the techniques for exemplifying the left-right difference in the elongation percentage of the rolled material described here are aimed at optimizing the reduction leveling as the control means. This is a technique for controlling the elongation rate of the steel sheet by a reduction leveling operation after a left-right difference occurs, and does not optimize the reduction leveling setting before the start of rolling.

One of the most important factors in setting the reduction leveling before the start of rolling is the zero point adjustment of the reduction position. Usually, in the operation of a strip rolling mill, the zero point adjustment of the rolling position is performed after the rolls are recombined. As this method, after incorporating a new roll, the kiss roll was tightened by operating the reduction device in the roll rotating state, and the measured value of the tightening load by the load cell for rolling load measurement matched the predetermined zero adjustment load. In many cases, a method of setting the time point as the zero point of the rolling position is adopted. At this time, the difference between the left and right reduction positions, that is, the zero point of the reduction leveling is often adjusted at the same time. Regarding the zero point adjustment of the reduction leveling, the method of adjusting the load measured by the rolling load measuring load cell when tightening the kiss roll is adjusted so that it matches the predetermined zero point adjustment load on both the working side and the driving side. There is. Kiss roll tightening means
This means that the upper and lower work rolls are brought into contact with each other in the absence of the rolled material to apply a load between the rolls.

When the zero point adjusting method of the rolling position and the rolling leveling as described above cannot be satisfactorily adjusted, the copper rod or the aluminum plate is tightened by the upper and lower work rolls, and the left and right balance of the thickness of the remaining indentation is used as a reference. In many cases, the zero point correction of the reduction leveling is performed.

[0009]

[Problems to be Solved by the Invention] As described above,
Even if the zero point adjustment method of the rolling position and the rolling leveling is adopted, it is rare that a problem of operation such as meandering or camber occurs due to the fact that the zero point adjustment of the rolling leveling cannot be performed accurately. Absent. At present, the operator judges such an operating condition and adjusts the rolling leveling, but it is not possible to eliminate the troubles such as meandering and camber due to the difference in the elongation rate of the rolled material.

Therefore, the present invention solves the problems of the conventional method relating to the method of adjusting the zero point of the rolling position of the plate rolling machine as described above, and particularly the rolling zero point of the plate rolling machine capable of accurately adjusting the zero point of the rolling leveling. Provide adjustment method.

[0011]

Means for Solving the Problems As a result of thorough investigation and analysis, the present inventors have found that the difference between the rolling loads measured by the load cell of the rolling mill includes the rolling load distribution between the rolled material and the work rolls. In addition to the left-right asymmetry with respect to the mill center, for example, between a work roll and a reinforcing roll in the case of a four-high rolling mill, a work roll and an intermediate roll in the case of a six-high rolling mill,
It was found that the thrust force acting between the intermediate roll and the reinforcing roll in the roll axial direction was included as the largest factor. In addition to these, when tightening the kiss roll such as when adjusting the rolling zero point of the plate rolling machine described above, a thrust force also acts between the upper and lower work rolls, and these thrust forces give an extra moment to the rolls. The distribution of the contact load between the rolls in the axial direction of the roll changes so as to balance with the above, and this finally appears as a disturbance with respect to the left-right difference of the load measured by the rolling load measuring load cell of the rolling mill.

The main cause of the above-mentioned inter-roll thrust force is that the rotational axes of the adjacent rolls contacting each other deviate from the parallel position by a slight gap between the roll chock and the housing window. When an error occurs in the parallelism between the adjacent roll axes in this way, a deviation component in the roll axis direction is generated in the roll peripheral velocity vector of both rolls due to the roll rotation. Will always cause a slip in the roll axis direction. The force generated by such slipping is the thrust force between the rolls, and the force continuously generating the slipping is the thrust reaction force acting from the keeper plate or the like that fixes the roll chock in the axial direction.

As described above, the inter-roll thrust force is generated due to a slight parallelism error between the rotation axes of the adjacent rolls, and therefore its direction and size are generally unknown. It is an unstable thing that can change from moment to moment with change. Therefore, even when performing the reduction zero point adjustment, since the disturbance due to the thrust force between the rolls is mixed in the left-right difference of the rolling cell for measuring the rolling load as described above, the reduction zero point adjustment that separates this influence is performed. I know I need to

[0014]

Therefore, the present invention according to claim 1 is a method of adjusting the zero point of the rolling position of a multi-high rolling mill having four or more stages, in which the rolling position is operated while the roll rotation is stopped, and the kiss roll is tightened. Then, the measured values of the tightening load by the rolling load measuring load cells provided on the working side and the driving side of the rolling mill are respectively determined to be the rolling positions at the time when the predetermined zero adjustment loads are obtained, and the above procedure is rolled. Change the position in the rotation direction by 2 levels or more, and perform the averaging process for the reduction position determined by each tightening work for each of the working side and the driving side, and reduce the obtained average value. The gist is the method of adjusting the rolling zero point of the plate rolling mill that sets the position zero point.

According to a second aspect of the present invention, there is provided a method for adjusting the zero point of the rolling position of a multi-high rolling mill having four or more stages, in which the rolling device is operated while the roll rotation is stopped to tighten the kiss roll. A step of determining the zero point of the left-right difference of the rolling position with reference to the measured tightening load by the rolling load measuring load cells provided on the working side and the driving side of the rolling mill, and the rolling load measuring load cell in the roll rotating state. A method of adjusting the rolling zero point of a plate rolling machine is characterized in that it comprises a step of determining a zero point of the average value of the rolling position on the left and right with reference to the total value of right and left of the rolling mill. Claim 1 corresponds to the first embodiment, and claim 2 corresponds to the second to fifth embodiments.

[0017]

As described above, the thrust force between the rolls is generated as the rolls rotate. Therefore, according to the method of claim 1, since the kiss roll tightening is performed in a state where the roll rotation is stopped, the thrust force between the rolls is not substantially generated, and the rolling position and the rolling position that do not include the disturbance due to the thrust force. It is possible to adjust the zero point of leveling. Further claims
In the first method, the position of the roll in the rotation direction is changed by two levels or more, and the kiss roll tightening is performed. When the position of the roll in the rotation direction is changed in this way, if there is significant eccentricity and a variation similar to this in the roll rotation axis, the reduction position that becomes the predetermined zero point adjustment load will vary according to the amount of eccentricity. . In this way, by averaging the roll-down positions where a predetermined zero-point adjustment load is applied to a plurality of roll positions, it is possible to perform the roll-down position and the zero-point adjustment of the roll leveling that average the effects of roll eccentricity.

[0018]

Further, as the pressure zero point adjustment method according to claim 1, be carried out kiss tightening a roll rotation stop state, the actual rolling state roll rotation stopped state and the roll is rotating, generally, the roll chock The behavior of the bearing part inside is very different. In particular, when an oil film bearing is used for the reinforcing roll, the oil film thickness on the pressure receiving surface of the bearing is extremely small when the roll rotation is stopped.However, when the roll is rotated, the oil film thickness is reduced due to the effect of drawing the lubricating oil accompanying the rotation. Is significantly increased, and the roll opening to be evaluated by the gap between the upper and lower work rolls is changed accordingly. Even if a roller bearing is used, this change occurs although it is small in quantity. In order to consider the change in the roll opening degree due to such roll rotation, in the related art, the zero point adjustment of the rolling position is performed under the roll rotating state, and the above-described problem of the inter-roll thrust force occurs. Of.

However, since the bearings used for the rolling mill rolls have extremely high processing precision, there are few individual differences, and the bearing and the drive side are driven by the above-described changes in the oil film thickness due to roll rotation. It is extremely unlikely that a significant difference will occur with the side. Therefore, in the method according to the second aspect , the roll-to-roll thrust is determined by determining the left-right difference of the reduction position, that is, the zero point of the reduction leveling, from the measured values of the kiss roll tightening load in the roll rotation stopped state by the working-side and driving-side load cells. Corrects the zero point of the rolling leveling without the influence of force, and determines the zero point of the average value of the rolling position on the left and right sides from the total value of the left and right load cells in the roll rotation state, thereby compensating for the above-mentioned characteristic changes of the bearing of the reinforcing roll. It becomes possible to do. That is, when the roll is rotating, thrust force between the rolls is generally applied.Therefore, a significant disturbance occurs in the left-right difference of the load cell load due to the moment acting on the reinforcing roll due to the thrust force. Since the value is determined irrespective of the above moment, the average value of the reduction position irrelevant to the left-right difference of the load cell load, that is, by performing the zero point adjustment of the reduction position in the simultaneous reduction mode on the working side and the drive side, The oil film thickness of the reinforced roll bearing described above can be corrected.

[0021]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 7, there is shown a side surface on a working side of a four-high rolling mill as a rolling mill to which the method of the present invention is applied. Needless to say, the four-high rolling mill is merely an example, and the present invention can be applied to a five-high rolling mill or a six-high rolling mill or more in which an intermediate roll is further added. It is understood by those skilled in the art that the drive side of the rolling mill main body, which is not shown, has substantially the same configuration as the working side.

In FIG. 7, the rolling mill 10 includes work rolls 14a and 14b rotatably supported in the housing 12 via work roll chocks 18a and 18b and reinforcement roll chocks 20a and 20b, and reinforcement rolls 16a and 16a.
It is provided with 16b and constitutes a four-high rolling mill. The housing 12 is provided with a pair of left and right, that is, a working side and a driving side rolling down device 22, and controls the position of the upper reinforcing roll chock 20a via a load cell 24. In FIG. 7, 24 is a rolling load measuring load cell,
Reference numerals 26a and 26b are incremental work roll bending devices, 28a and 28b are decrease work roll bending devices, and 30a and 30b are reinforcing roll balance devices. In the present embodiment, the roll bending device 26
The a, 26b, 28a, 28b and the reinforcing roll balance devices 30a, 30b are hydraulic devices, and as an example, measure the hydraulic pressure in the hydraulic pipe 34 and the hydraulic pipe 34 that supply the hydraulic pressure to the incremental work roll bending device 26a. Although the working roll bending device operating hydraulic pressure measuring device 32 is illustrated, other roll bending devices and roll balance devices are also configured in substantially the same manner.

As another configuration, the present invention is applicable to various types of rolling mills, such as when the rolling load measuring load cell is on the lower side and when the hydraulic pressure reducing device is disposed on the lower side or the upper side. is there.

Next, a method of adjusting the rolling zero point of the sheet rolling mill according to the embodiment of the present invention will be described with reference to FIGS. 1 to 6. First, FIG. 1 is a flowchart showing an algorithm common to the respective embodiments of the method for adjusting the rolling zero point of a strip rolling mill according to the present invention . Normally, the zero-point adjustment of the rolling position is performed after changing the rolls, that is, after changing the work rolls 14a and 14b or the reinforcing rolls 16a and 16b or both rolls. This is because when the used roll is taken out and a new roll is installed, the difference in roll diameter between the old and new rolls appears as an error in the roll opening for the same rolling position. FIG. 1 also shows an example of a method for adjusting the zero point of the rolling position, which is carried out immediately after such roll rearrangement.

First, the work rolls 14a, 14b or the work rolls 14a, 14b and the reinforcing rolls 16a, 1
6b roll rearrangement is executed (step S10).
Next, in a state where the roll rotation is stopped, the pressing device 22 is used to tighten the kiss roll, and the procedure of tightening to a load exceeding a predetermined zero point adjustment load and unloading is repeated several times (step S12). Usually, immediately after the roll is stopped, the oil film introduced during the roll rotation often remains on the pressure receiving surface of the bearing, and the oil film is gradually discharged from the pressure receiving surface for the load after the stop. As a result, the relationship between the rolling position and the load cell load gradually changes. In order to avoid such a transient phenomenon, in the present embodiment, the load up to the load exceeding the predetermined zero adjustment load is repeated several times. By performing such a procedure, the state of the oil film in the bearing is stabilized, and reproducibility can be obtained in the relationship between the rolling position and the load cell load when the roll rotation is stopped. Regarding the number of repetitions of this procedure, it is sufficient to repeat the tightening of the kiss roll while the roll is actually stopped and to find the number of times that the correspondence relationship between the rolling position and the load cell load is reproducible. Specifically, in the case of an oil film bearing, it is often sufficient to carry out it two to three times.

Next, while the roll rotation is stopped, the rolling-down device 22 is operated and tightened until the load measured values by the work-side and drive-side rolling load measuring load cells 12 become predetermined zero-adjustment loads. (Step S14).
As the tightening method at this time, for example, first, while observing the total value of the working side and the driving side of the rolling load measuring load cell 24, tightening is performed in the simultaneous rolling-down mode on the working side and the driving side, and the total value is a predetermined value. After the zero adjustment load is reached, a practical method is to operate the work-side and drive-side reduction positions by the same amount in opposite directions, that is, to adjust the work-side and drive-side load balance in the reduction-leveling operation mode. In order to realize the zero point adjustment load with higher accuracy, it is preferable to repeat these two steps S12 and S14.

As described above, the working side and the driving side are individually adjusted with the load measurement values by the rolling load measuring load cell 24 to the predetermined zero point adjusting load, and the rolling positions at that time are set to the working side and the driving side. The zero point of the rolling position is individually set (step S16). Here, for the predetermined zero point load, it is preferable to adopt the vicinity of the load that is most frequently generated in the actual rolling operation, and normally, this is evenly distributed to the working side and the driving side, and individual targets are set. The value. For example, when the zero-point adjusting load is 1000 t (ton), the target values on the working side and the driving side are 500 t. However, depending on the specifications of the reinforced roll bearing, it may not be possible to load the load frequently generated in the actual rolling operation under the condition where the roll rotation is stopped. In such cases,
The maximum load that does not damage the bearing when stopped is the zero adjustment load.

FIG. 2 is a flow chart showing the algorithm of the method for adjusting the reduction zero point of the strip rolling mill according to the first embodiment of the present invention. As the above-mentioned common algorithm , first, the work rolls 14a, 14b or the work rolls 14 are
Roll rearrangement of a and 14b and reinforcing rolls 16a and 16b is executed (step S20). Next, after the kiss roll tightening for stabilizing the oil film thickness of the reinforcing roll bearing was carried out several times (step S22), the rolling load measurement load cell 24 on the working side and the driving side was used with the roll rotation stopped. The screwing device 22 is operated and tightened until the load measurement values reach the predetermined zero-point adjusting loads, and the rolling-down positions at which the predetermined zero-point adjusting loads are reached are recorded (step S24).

In the first embodiment, the rotational position of the roll is changed and the above operation is repeated a plurality of times. To this end, in step S26, a plurality of predetermined levels of measurement positions, that is, roll rotation positions, for example, the reinforcing roll 1
It is determined whether or not the measurement is completed for all four measurement positions every 90 ° around the rotation axes of 4a and 14b. If not completed, that is, if No in step S26, the routine changes the rotational position of the reinforcing roll (step S28) and returns to step S22. Regarding the change of the rotation position of the reinforcing rolls 16a and 16b at this time, the reinforcing rolls 16a and 16b are changed in the whole measurement.
It is preferable to carry out conditions under which the rotation angle of b changes by at least 180 °, and to carry out kiss roll tightening at as many positions as possible. Further, considering that the positions of the upper and lower reinforcing rolls 16a and 16b gradually shift relative to each other due to the difference in the diameters of the upper and lower reinforcing rolls 16a and 16b, the upper and lower reinforcing rolls 16a and 16b.
It is preferable to measure at different levels of positional relationship. Further, it is preferable to add different levels of the circumferential positions of the work rolls 14a and 14b. However, if the number of condition levels to be measured is too large, the zero adjustment work will take a long time, and the work efficiency will decrease.
Only once, perform thorough measurement in consideration of all of the roll eccentricity factors described above, and from the measurement results, identify the conditions that do not cause a large reduction position fluctuation factor. It is also possible to carry out the kiss roll tightening by omitting the condition.

When the measurement at the predetermined roll rotation position is completed as described above, that is, when the result at step S26 is Yes, the measured values of the rolling-down positions for the measured plurality of roll rotation positions are set for each of the working side and the driving side. The average value of is set as the zero point of each rolling position (step S3).
0). This method of setting the zero point is easy to perform only by software processing, but if there is no such software, kiss roll tightening is performed up to the average value of the actually calculated reduction positions, and There is no problem with the method of clearing the rolling position to zero. Further, in the averaging process of the rolling position, it is convenient to use a simple arithmetic mean, but for example, the average value may be calculated assuming that the measured values are normally distributed, and other The averaging process may be performed after introducing an evaluation standard and performing artificial weighting. In addition to the method of individually averaging the working-side and driving-side rolled-down positions as in the example of FIG. 2, the average value of the rolled-down positions and the left-right difference from the simultaneously measured working-side and driven-side rolled-down positions are measured. That is, the reduction leveling may be calculated, and the average value and the reduction leveling may be separately averaged by different methods.

FIG. 3 is a flow chart showing the algorithm of the method for adjusting the rolling zero point of the strip rolling mill according to the second embodiment of the present invention. In the embodiment of FIG. 3, the algo shown in FIG.
Performed a rhythm (steps S40 to S4
6) After that, the work rolls 14a and 14b and the reinforcing roll 1
6a, 16b are rotated at a predetermined rotation speed, the working side and drive side reduction positions are tightened in the simultaneous reduction mode, and the total value of the load measured values by the rolling load measuring load cell 24 on the work side and the drive side is tightened. Is tightened so as to match the predetermined zero point adjustment load (step S48). Further, the rolling reduction position in a state where the total value of the predetermined zero-point adjustment loads is realized is newly set as the zero point of the rolling reduction position (step S50).

Here, the predetermined roll rotation speed is preferably a value close to the average value of the roll rotation speed when the rolling operation is actually performed. Further, the simultaneous reduction mode is an operation mode in which the left and right reduction positions are changed in the same direction by the same amount while the left-right difference between the reduction positions, that is, the reduction leveling is fixed. As long as the operation is performed in the simultaneous reduction mode, the reduction leveling does not change. Therefore, by performing the above operation, the oil film thickness introduced to the pressure receiving surface of the reinforced roll bearing by the roll rotation is independent of the left-right difference of the load cell load due to the thrust force generated between the rolls due to the roll rotation. The left and right average values, the working side,
The rolling position is corrected evenly on the driving side.

FIG. 4 is a flow chart showing an algorithm of the method for adjusting the rolling zero point of the strip rolling mill according to the third embodiment of the present invention. In the embodiment of FIG. 4, after performing the reduction zero point adjustment of the embodiment shown in FIG. 2 (step S60 to step S70), the work rolls 14a and 14b and the reinforcing rolls 16a and 16b are rotated at a predetermined rotation speed. In this state, the work side and drive side reduction positions are tightened in the simultaneous reduction mode so that the total value of the load measurement values by the work load side and drive side rolling load measurement load cells 24 matches the predetermined zero point adjustment load. Tighten (step S72). Next, the rolling reduction position in a state where the total value of the predetermined zero point adjustment loads is realized is set again as the zero point of the rolling reduction position (step S74).

Here, the predetermined roll rotation speed is preferably a value close to the average value of the roll rotation speed when the rolling operation is actually performed. Further, since the rolling operation in the roll rotating state is performed in the simultaneous rolling mode, the rolling leveling does not change. Therefore, by performing the above-mentioned operation, regardless of the left-right difference of the load cell load due to the thrust force generated between the rolls due to the roll rotation, the load is introduced to the pressure receiving surface of the bearing of the reinforcing rolls 16a and 16b by the roll rotation. The rolling position is corrected evenly on the working side and the driving side by an amount corresponding to the average value of the left and right oil film thicknesses. By the way, when the roll eccentricity exists, the load cell load generated by the kiss roll tightening in the roll rotating state changes with the rotation of the roll, but when the amount of change is large, for example, for several cycles of the load cell load change. The data may be continuously collected, and the reduction position at which the average value becomes a predetermined zero point adjustment load may be searched for in the simultaneous reduction mode.

FIG. 5 is a flow chart showing the algorithm of the method for adjusting the rolling zero point of the strip rolling mill according to the fourth embodiment of the present invention. In the embodiment of FIG. 5, the order of the zero point adjustment of the reduction leveling and the zero point adjustment of the right and left average values of the reduction is switched in the method of adjusting the zero point of the reduction of the embodiment shown in FIG. That is, as shown in FIG. 5, first, the rolls are recombined (step S80), the rolling device is rotated simultaneously in the left-right simultaneous rolling-down mode, and the total value of the load measurement values by the working-side and driving-side rolling load measuring load cells 24 is Tighten it so that it matches the specified zero point adjustment load (step S
82), and the reduction position in that state is set as the reduction zero point (step S84). Next, for the purpose of stopping the roll rotation and stabilizing the lubricating oil film on the pressure receiving surface of the reinforcing roll bearing, the tightening of the kiss roll is repeated several times (step S8).
6) After that, with the roll rotation stopped, the rolling device 22 is operated to tighten the kiss roll until the load measurement values by the rolling cells for measuring the rolling load on the working side and the driving side become the predetermined zero-adjustment loads. Implement (step S88). Then, the left-right difference of the reduction positions, that is, the reduction leveling amount in the state where the predetermined zero-point adjustment load is realized for each of the working side and the driving side is recorded (step S9).
0), the reduction leveling amount is distributed to the working-side reduction position correction amount and the driving-side reduction position correction amount so that the absolute values of the correction amounts become equal, and the zero points of the reduction positions on the working side and the driving side are respectively set. The correction is made by the correction amount and the zero point adjustment of the rolling position is finished (step S92).

According to the method of the fifth embodiment, after the rolls are reassembled, the load is first applied in the state of roll rotation. Therefore, after confirming that the rolls and bearings after the reassembling rotate normally, a full reduction zero point is obtained. Since adjustment can be performed, this is a preferred embodiment in terms of work efficiency.

FIG. 6 is a flow chart showing the algorithm of the method for adjusting the rolling zero point of the strip rolling mill according to the fifth embodiment of the present invention. In the embodiment of FIG. 6, the order of the zero point adjustment of the reduction leveling and the zero point adjustment of the right and left average values of the reduction is switched in the method of adjusting the zero point of the reduction of the embodiment shown in FIG. That is, as shown in FIG. 6, first, the rolls are recombined (step S100), the rolling reduction device is tightened in the left and right simultaneous rolling reduction mode while the rolls are rotated, and the total value of the load measurement values by the load cells 24 for rolling load measurement on the working side and the driving side is Is tightened so as to match the predetermined zero point adjustment load (step S102), and the rolling position in that state is set as the rolling zero point (step S104). Next, for the purpose of stopping the roll rotation and stabilizing the lubricating oil film on the pressure receiving surfaces of the bearings of the reinforcing rolls 16a and 16b, the kiss roll tightening is repeated several times (step S106), and then the roll rotation is stopped and the working side is stopped. And, the kiss roll is tightened by operating the reduction device until the load measurement values by the rolling load measuring load cell 24 on the driving side reach the predetermined zero-point adjusting loads. Then, the left-right difference between the reduction positions, that is, the reduction leveling amount in the state where the predetermined zero-point adjustment load is realized for each of the working side and the driving side is recorded (step S108).

This procedure is repeatedly executed for a plurality of predetermined roll rotation positions, and the average value of the reduction leveling amounts for all the roll position conditions is calculated.
That is, in step S110, it is determined whether or not the measurement has been completed for all of the plurality of predetermined roll rotation positions. If not completed, that is, step S
In the case of No in 110, the routine changes the position of the reinforcing roll in the rotation direction (step S112) and returns to step S106.

When the measurement of the predetermined roll position is completed as described above, that is, in step S110, Ye
In the case of s, the average value of the measured values of the rolling position with respect to the plurality of measured roll positions on the working side and the driving side is set as the zero point of each rolling position (step S114). Next, the average value of the reduction leveling amounts is distributed to the working-side reduction position correction amount and the driving-side reduction position correction amount so that the absolute values of the correction amounts become equal, and the zero points of the reduction positions on the working side and the driving side are distributed. Is corrected by the correction amount, and the zero point adjustment of the rolling position is completed (step S116).

According to the above method, after the rolls are reassembled, the load is first applied in the state of roll rotation. Therefore, after confirming that the rolls and bearings after the reassembling rotate normally, a full-scale rolling zero point adjustment can be performed. Since it can be carried out, it is a preferred embodiment in terms of work efficiency.

In the embodiments shown in FIGS. 3, 4, 5 and 6, kiss roll tightening is performed in a roll rotating state and the total left and right values of the load cell 24 for measuring the rolling load are observed. However, the operation of the reduction position is performed in the simultaneous reduction mode.The purpose of this procedure is to consider the effect of the lubricating oil film thickness on the pressure receiving surface of the reinforced roll bearing, as described above. Temperature changes may have a significant effect.In such a case, it is possible to perform roll zero rotation under load until these temperatures stabilize and then perform zero adjustment of the reduction position. preferable.

Further, in the above description of the embodiment, the example in which the zero point adjustment of the rolling reduction position is performed immediately after the roll reshuffle is described, but the zero point adjustment of the rolling reduction position does not need to be limited to such timing, and for example, the roll is When it is determined that a significant error has occurred in the zero point of the rolling position due to wear and thermal expansion of the rolls, it is also an effective embodiment to carry out without changing the rolls.

[0043]

As described above, according to the present invention, it is possible to perform much more accurate zero-point adjustment of the rolling position as compared with the prior art, and as a result, the frequency of occurrence of meandering or strip running in the rolling operation is significantly reduced. Further, since the camber and the thickness wedge of the rolled material can be significantly reduced, the cost required for rolling and the quality improvement can be achieved at the same time.

[Brief description of drawings]

[1] Each of the pressure zero point adjusting method for a plate rolling mill according to the invention
7 is a flowchart showing an algorithm common to the embodiments .

FIG. 2 is a flow chart of a method of adjusting a rolling zero point of a plate rolling mill according to the first embodiment of the present invention.

FIG. 3 is a flow chart of a method of adjusting a rolling zero point of a plate rolling mill according to a second embodiment of the present invention.

FIG. 4 is a flow chart of a method for adjusting a rolling zero point of a plate rolling mill according to a third embodiment of the present invention.

FIG. 5 is a flow chart of a method of adjusting a rolling zero point of a plate rolling mill according to a fourth embodiment of the present invention.

FIG. 6 is a flow chart of a method of adjusting a rolling zero point of a plate rolling mill according to a fifth embodiment of the present invention.

FIG. 7 is a side view of a four-high rolling mill to which the present invention is applied.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Ota 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Corporation Nagoya Steel Works (72) Inventor Katsuhiko Kawamoto 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Co., Ltd. Nagoya Steel Works (56) Reference JP-A-10-128416 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 37/00-37/78 B21B 31/20

Claims (2)

(57) [Claims] 1. A zero-point adjusting method for a rolling position of a multi-high rolling mill having four or more stages, wherein the rolling position is operated while the roll rotation is stopped to tighten the kiss roll, and the working side and the drive of the rolling mill. Determine the rolling position when the actual measured tightening load by the rolling load measuring load cell reaches the specified zero adjustment load, and change the position in the roll rotation direction by two levels or more by the above procedure. The rolling position determined by each tightening operation is averaged for each of the working side and the driving side, and the average value obtained is used as the zero point of the rolling position. Zero adjustment method. 2. A method for adjusting the zero point of the rolling position of a multi-high rolling mill having four or more stages, wherein the rolling device is operated in a state where the roll rotation is stopped to carry out kiss roll tightening, and the working side and the drive of the rolling mill. Based on the measured tightening load by the rolling load measuring load cell that is deployed on the side, the step of determining the zero point of the left-right difference of the rolling position, and the total value of the left and right rolling load measuring load cells in the roll rotating state as a reference,
And a step of determining a zero point of the left and right average values of the rolling position, the method of adjusting the rolling point of a strip rolling mill.