JPH09150209A - Method for grinding roll by on-line roll grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision of an ORG grinding and relax an rolling restraint in the shifting of rolling width by obtaining the ORG grinding efficiency to change a pushing force setting or a gain setting for the succeeding grinding and executing the grinding of an objective profile. SOLUTION: A profile arithmetic paer 3 calculates the profile of a roll based on a measuring signal from an on-line profile meter. A grinding deviation arithmetic part 4 compares the calculated profile and an already inputted target profile to calculate the deviation, and a necessary grinding quantity and the grinding efficiency are calculated at each head. An on-line roll grinding device control mechanism 5 decides the grinding quantity for the following grinding taking into consideration of the necessary grinding quantity and the grinding efficiency obtd. by the grinding deviation arithmetic part 4, and this command value is outputted. Each grinding command value adjusted through a grinding efficiency adjusting part 6 at each head is transferred to each grinding head and the pushing force is changed to execute the grinding into the objective profile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the grinding of work rolls of rolling rolls by means of an online roll grinder (online roll grinder, hereinafter simply referred to as ORG) installed in a rolling mill in the rolling of hot rolled or cold rolled steel sheet. The present invention relates to a grinding control method capable of accurately grinding a target profile to obtain a desired roll shape.

[0002]

2. Description of the Related Art Generally, in a rolling roll used for rolling a steel sheet, only a portion corresponding to the steel sheet passing portion is worn and a step is formed between the steel sheet non-passing portion and the non-steel passing portion. When this step progresses, the thickness deviation of the steel plate cross section becomes large, or when rolling the wide steel plate next to the narrow steel plate, the cross section of the steel plate becomes a cat-ear shape, which deviates from the product quality standard. And reduce the product yield. Therefore, there is an inconvenience that the rolling order and the rolling length have to be restricted in the rolling of the actual machine. As a result, it is difficult to realize rolling in which the order of tapping is the rolling order and the width can be reversed, that is, so-called schedule-free rolling.

Conventionally, in order to solve such a problem,
It has been attempted to install a roll grinding device in a rolling mill and grind the roll during rolling or during unrolling between rolling to eliminate the above-mentioned wear step. In particular, recently, an online roll grinder has been proposed in which a disk-shaped rotary grindstone is directly pressed onto the surface of a roll to be ground so that the rotary grindstone can traverse in the roll axial direction. For example,
JP-A-6-190410 and JP-A-6-30461
Japanese Unexamined Patent Publication No. 4 discloses the ORG device itself and its control method.

Further, in order to use the above-mentioned ORG in a suitable state, it is important to accurately grasp the current profile of the roll to be ground, and therefore, even in the conventional case, as disclosed in Japanese Patent Publication No. 3-17283. There are known roll profile measurement methods using various ultrasonic waves, an online profile meter for inputting measured values from a contact type or non-contact type profile sensor such as Japanese Patent Publication No. 6-59487, and calculating the profile.

Further, Japanese Patent Laid-Open No. 6-63616 also proposes a rolling mill in which an ORG and a roll profilometer are integrally formed in order to accurately measure the profile of a rolling roll.

[0006]

However, in the related art, the ORG and the on-line profilometer are separately disclosed, and there are few examples in which they are rationally combined. Further, even in the technique disclosed in Japanese Patent Laid-Open No. 6-63616 in which an ORG and a roll profile meter are integrated, the difference between the target roll profile and the measured roll profile is compensated by changing the pressing force. When grinding, various factors such as
A target grinding amount cannot be obtained in many cases due to reasons such as clogging of the grindstone and variations in accuracy. In other words, in conventional grinding, since the grinding efficiency up to that point was not considered at all, the originally required pressing force could not be set, and the target profile could never be reached. Become.

The present invention has been made to solve the above-mentioned problems of the prior art. When grinding an ORG, the grinding amount is determined in consideration of the grinding efficiency up to that time, thereby improving the grinding accuracy. The objective is to increase the amount of low-crown material incorporated and achieve schedule-free performance while improving. The low crown material here means
The plate thickness deviation between the plate center part and the plate edge part does not exceed about 50 μm.

[0008]

A grinding method of the present invention for achieving the above object is to provide roll profile measuring means between stands of continuous steel plate rolling mills, and to provide an ORG in the rolling mill. When grinding the work rolls of the rolling rolls, the initial roll profile is measured by the roll profile measuring means, the amount of roll wear is predicted by the rolling conditions to determine the grinding amount, and the grinding is started. Calculate the grinding efficiency based on the data of machine pressing force and roll speed and the measured value of the roll profile after grinding, and use this grinding efficiency to change the pressing force setting or gain setting at the time of grinding from the next time onward and change the target profile. It is characterized by performing grinding to. It is preferable that the above-described grinding control operation for the target profile is independently performed for each grinding unit installed in at least two or more work rolls.

As described above, the grinding of the rolling roll is to eliminate the wear level difference between the plate passing portion (wearing portion) and the non-passing plate portion (unwearing portion). The amount of wear is predicted based on the initial roll profile measurement value by the profile measuring means and the rolling results up to that time, and the initial grinding amount (specifically, the grindstone pressing force and the grindstone traverse speed) is determined. However, in reality, it is often impossible to grind to a set grinding amount due to clogging of the whetstone or variations in whetstone accuracy. Therefore, the profile of the rolled roll after grinding is measured by the roll profile measuring means, and this difference is compared with the initial profile to detect the difference, and the rolling history (rolling load, roll speed, etc.) from the roll change is detected. , ORG pressing force is taken into consideration to obtain the grinding efficiency α. Then, in the next grinding, the ORG grinding efficiency is used, that is, the pressing force is set so that the grinding efficiency is almost 100%, and the target profile, that is, the grinding in which the wear step is eliminated is executed. This can be expressed as follows. P _β = 1 / α × (1 / M × P _E + P _N ) where P _β : Next pressing force, α: Grinding efficiency α = Actual grinding amount / Target grinding amount M: Online profile measurement cycle P _E : Target grinding ORG pressing force required for grinding of the unachieved grinding amount β against the amount, P _N : Required ORG pressing force estimated from the next strip wear

Further, since the grinding amount and the grinding efficiency are not the same between the upper and lower rolling rolls of the same stand and also in grinding the left and right unworn portions of the same rolling roll, the feedback learning grinding of the present invention described above is performed. Control is
It is desirable to carry out independently for at least two grinding units installed on each rolling roll. In addition, it is preferable that the measurement by the on-line roll profile measuring means can be performed at any time with an arbitrary setting.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows 4Hi (of course, 6Hi may be used).
2 shows an embodiment in which the present invention is applied to work roll grinding of the hot rolling mill. In the figure, DW
_H and DW _L are upper work rolls and lower work rolls for rolling the material S to be rolled, and 1A and 1B are upper working grindings installed in the rolling stand in the vicinity of the rolls for grinding the upper work rolls and the lower work rolls. The head and the lower working grinding head constitute an ORG as will be described later. 2A
Reference numerals 2B and 2B are online profile meters provided corresponding to the respective work rolls, and measure the profile of the work rolls.

Further, 3 is a profile calculator for calculating the profile of the roll based on the measurement signals from the online profile meters 2A and 2B, and 4 is a comparison between the calculated profile and the target profile already input. A grinding deviation calculation unit that calculates the deviation and calculates the required grinding amount and grinding efficiency for each head determines the next grinding amount in consideration of the necessary grinding amount and grinding efficiency obtained by the grinding deviation calculation unit 4. , An online roll grinding device control mechanism for outputting the command value, 6 is a grinding efficiency adjusting unit for each head, and takes into consideration a grinding efficiency coefficient unique to each head, and each grinding command value adjusted through this Is sent to each grinding head, and the pressing force is changed to perform grinding to a target profile. Further, the pressing force gain may be changed instead of the pressing force.

The on-line profile meter may be of any type as long as it can accurately measure the roll profile between rolling stands and online. For example, any measuring means such as a conventionally known measuring means using an ultrasonic range finder or a measuring means using a plurality of distance measuring devices arranged close to the roll surface may be selected.

FIG. 2 shows an outline of the ORG, where 1 is O.
RG grinding head unit, 7 is ORG grinding wheel, 8 is O
RG grinding head traverse rail, 9 is a rolling roll as a material to be ground, and 10 is a chock of the rolling roll. At least two grinding head units 1 are arranged for one rolling roll 9 as shown in the drawing, and each of them is independently controllable, that is, the pressing force and the traverse speed can be individually controlled. It has become. The grinding wheel 7 is traversable along the traverse rail 8 (that is, in the roll axis direction),
Further, it is held so as to be able to move back and forth with respect to the roll surface.

[0015]

EXAMPLE FIG. 3 shows an example of a grinding flow chart when the present invention is applied to work roll grinding of a rolling roll, and each step will be described below.

(1) Setting of Roll Profile Measuring Period First, the measuring period (= rolling number) of the online profile meter is set (determination of learning period). (2) Measurement of initial roll profile At the start of grinding by the ORG, the initial roll profile is measured by an online profile meter and initial setting is performed. (3) Calculation of ORG grinding set value and command Calculate the predicted value of roll wear amount according to rolling conditions. The predicted value is commanded to the ORG as a grinding target value. Examples of rolling conditions include rolling load, roll rotation speed, and steel plate size. (4) ORG Grinding ORG grinding is performed, and the profile measurement cycle: M is integrated one by one. (5) M actual result M actual result = setting value (M) is checked, and if NO, the process returns to the above (3). If YES, proceed to the next. (6) Roll profile measurement Re-measure the roll profile with an online profile meter. Here, the roll wear amount a, the thermal crown amount b, and the ORG grinding amounts Cr _{1 to} Cr _n are shown in FIG. (7) Calculation of ORG grinding efficiency Based on the result of (6), the difference between the target value and the actual value of the grinding amount is recognized as the grinding efficiency. This is done for each grinding head. (8) Calculation of ORG grinding command, grinding efficiency is 100% considering the grinding efficiency found in command (7).
Is reflected in the grinding command value. This is done for each grinding head. In this case, the pressing force of the grinding wheel is changed. (9) Determine whether or not to continue ORG grinding. If there is a command value for the grinding end signal, if YES, go to the next step, N
If O, return to (3). Usually, as a command for the grinding end signal, a command for roll replacement or some artificial command can be considered. (10) The ORG grinding is completed.

[0017]

As described above, according to the roll grinding method of the present invention, the grinding efficiency of the ORG which has not been taken into consideration up to now is introduced into the grinding of the next time and thereafter, so that the originally required grinder pressing force is required. Can be set, and online grinding accuracy is improved. As a result, it is possible to alleviate the rolling restriction of rolling width transition and to expand the incorporation of low crown material.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an embodiment in a case where the present invention is applied to work roll grinding of a 4Hi hot rolling mill.

2 is an explanatory plan view showing a specific example of the grinding head in FIG.

FIG. 3 is a grinding flowchart showing an embodiment of a grinding method according to the present invention.

FIG. 4 is a diagram schematically showing a cross section of a rolling roll.

[Explanation of symbols]

1A Upper operation control grinding head 1B Lower operation control grinding head 1 ORG grinding head unit 2 Online profile meter 3 Profile calculation unit 4 Grinding deviation calculation unit 5 Online roll grinding device control mechanism 6 Grinding efficiency adjustment unit 7 ORG Grinding wheel 8 ORG grinding head Traverse rail 9 Rolling roll 10 Roll chock DW _H Upper work roll DW _L Lower work roll S Rolled material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Kimura 1 Nishinosu, Oita City, Oita Prefecture New Nippon Steel Co., Ltd. Oita Steel Co., Ltd.

Claims (2)

[Claims] 1. A roll profile measuring means and an on-line roll grinder are arranged between stands of a continuous steel plate rolling mill or inside the rolling mill, and when the work roll of the rolling roll is ground by the online roll grinder, the roll profile is measured. Measure the initial roll profile by the measuring means, predict the amount of roll wear according to the rolling conditions, determine the amount of grinding, and start grinding. Online roll grinding characterized by determining the grinding efficiency based on the roll profile measurement value and using this grinding efficiency to change the pressing force setting or gain setting for the next and subsequent grindings and perform grinding to the target profile. Machine grinding method. 2. The grinding method according to claim 1, wherein the grinding control operation to the target profile is performed independently for each grinding unit installed in at least two or more work rolls.