JPS60196215A - Method for controlling tension of rolling material - Google Patents

Abstract

PURPOSE:To prevent drawing down and slip of a rolling material by performing tracking with the hardness change rate of the rolling material detected on the inlet side of the line as information, calculating the hardness change rate between the respective stands and correcting the target value of the tension between the stands. CONSTITUTION:A hardness change rate is detected for each information segment of the unit length of a rolling material on the inlet side of the rolling line and tracking is performed up to the final stand in accordance with such information. The representative hardnes change rate of the rolling material passing between the respective stands is calculated in accordance with the tracking information. The target value of the reference tension between the stands set between the respective stands is corrected with respect to the change rate. The roll speed and roll gap are further adjusted and corrected according to the corrected target tension value. The target tension value between the stands is thus automatically corrected in accordance with the change components occurring in skid marks, etc. and the sharp decrease in rolling load is prevented.

Description

[Detailed description of the invention] The present invention relates to a tension control method for a tandem rolling mill.

Tension control of rolled material in cold rolling line has conventionally been carried out by changing the roll speed of the busy rolling mill, roll speed, etc. so that the tension of the rolled material is equal to a preset basic tension or within a predetermined tension control range. Constant tension control or constant tension limit control is used to control the opening.

The hardness of a hot-rolled original plate (hot coil) is not necessarily constant over its entire length, and some hardness changes occur due to differences in carden equivalent, skid marks, etc. Figure 1 (
, ), the tension T, rolling load P, and exit plate thickness fluctuate (decrease) as shown by solid lines. When this tension fluctuation occurs,
In the case of constant tension or constant limit control as described above, the tension control system works in the direction of increasing the tension of the rolled material, reducing the roll speed si or opening the roll opening C2 as shown by the chain line in Fig. 1. invite However, reducing the roll speed S1 works in the direction of making the plate thickness thinner, and opening the rolls further reduces the rolling load, and in extreme cases, it causes narrowing of the rolled material and slits f-f. There is.

The present invention was made in view of the above-mentioned conventional problems, and detects the amount of change in hardness of each certain length of the rolled material at the entry side of the rolling line and tracks the rolled material up to the final stand. Then, the reference tension target value is corrected between each stand based on the amount of change in hardness, and the tension at the above rolling yield is adjusted according to the roll speed or roll opening degree to enable appropriate rolling. By adopting a configuration that controls the rolling material, even if the rolling roll bites into areas with hardness changes due to skid marks, etc., the rolling material can be narrowed down, prevent slips, and ensure stable operation of the rolling line. The purpose of this invention is to provide a method for controlling tension in materials.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 2, 1, 2. ..., l are the first stand, second stand, ... of the cold rolling line, respectively.
. . . is the first stand, and the central stand is a pivot stand, each of which is equipped with a rolling roll speed control device 1S, 28°...iS, a rolling reduction control device 1C12C, . . . ..LC and load cells IL, 2L, . . . iL are provided. I
X, 3X, ... iX is a thickness meter (X-ray thickness meter),
2T, 3T.

....iT is a tension detector.

Reference numeral 10 denotes an original plate hardness change detection unit, which includes a thickness gauge 1 on the entry side.
a plate thickness tracking section 10A consisting of N' storage sections in which 1/N' of the path between the X-first stands is one information section;
While the rolled material passes under the surface of the first stand by 1/N of the path between the first and second stands, the amount of change in hardness of the passed portion is calculated and supplied to the hardness tracking information processing unit 20. It also includes a calculation section 10B. While the rolled material passes directly under the thickness gauge 1X on the entrance side, the thickness deviation from the thickness gauge is calculated from the memory section of the first section 11 to the memory section of the second section 21 as shown in FIG. 3(a)K. Then, the rolled material is tracked sequentially to the storage section of the N1 category. The hardness change calculation section 10B includes the output P1 of the load cell 1L that detects the rolling load of the first stand, the output ΔHi of the N1 section of the plate thickness tracking section 104, the roll opening G1 of @1 stand, and the output P1 of the load cell 1L that detects the rolling load of the first stand. The output Tfl of the tension detector 2T that detects the front tension, that is, the tension between the first and second stands is sampled at a predetermined period, and the following equation (11
-1, (1) -2, calculate the hardness change amount ΔQn.

(1-2) PI rolling load Ql deformation resistance H, entrance side plate thickness hl exit side plate thickness Tf, front actual tension G, roll opening M1 mil constant (subscript is stand number) ΔXllXll stand entrance side X-ray plate thickness deviation output Tx Transfer time S laglas operator This plate thickness hardness change amount ΔQn is the rolling material between the 1st and 2nd stands, the 2nd and 3rd stands... 1-1-i
As the progress is made between t stands, the 1st-g2 stand tracking information processing section 200, @2-3rd stand tracking information processing section 300... t-1st - ith stand tracking information processing section 200, @2-3rd stand tracking information processing section 300...
The information is sequentially transferred to the stand tracking information processing unit i00. Note that the information on each stand-to-stand path is divided into N sections as shown in FIG. 3(b), similar to the thickness gauge 1X-first stand path. Ti? The information processing section 200 has N storage sections whose information sections are the first section 12, the second section 22, . . ., the N2 section shown in FIG. 1 section 12, 2nd section 22... Original plate hardness change amount ΔQll, ΔQ of the rolled material portion passing through the N2 section
12...ΔQin (1=2) is written.

101 is an inter-stand representative hardness change calculation unit, m
l-1-First stand tracking information processing unit 100 also changes original plate hardness ΔQil, ΔQi2...ΔQ
in is taken in at predetermined time intervals, and the inter-stand representative hardness h minimization amount ΔQ(i) is calculated based on the following equation (2).

i02 is a tension target value calculation unit, which determines whether or not the representative hardness change amount between stands ΔQ(i) is within a preset hardness change limit value ±ΔQ(i)o circle, and determines whether or not it is within the limit range. If it is outside the hardness change limit ±ΔQ(i)o, the standard tension target value TF(i) (limit width: ±αi) is output, but if it is outside the hardness change limit ±ΔQ(i)o, the following formula (3) is output. Corrected tension target value Tf(i) (however, limit width: ±β
i) is calculated and output.

'ff(i)=TF(1)+ΔT(i)xWxHi(3
) However, W: plate thickness, Hl: plate thickness, ΔT(i) is the unit tension change amount, and the calculation method will be described later.

In i03, the actual tension value Tfi and the reference tension target value TF(1
) or the corrected tension target value Tf(i), and outputs the deviation δ direct i) as is, but if the above tension target value plus mint value (Tf(1)+β) is shown in Fig. 4(,). When the tension target value permissible band shown in FIG.

Reference numeral 104 denotes an operation system switching unit (switch switch) which, when receiving a lowering operation priority command +Yi (described later) from the monitor part 105 (excluding the monitor part 105), switches the output of the tension target value filter part [03]. When the pressure control device IC receives a speed operation priority command ~Y1, which will be described later, the output of the tension target value filter section 103 is input to the speed control device IS, i.
lS... (if upstream from the pivot stand), or speed control device i+Is, l+2S...
...(If downstream from the pivot stand) Input "1"
-ru.

This monitor part 1o5 (excluding monitor part 105) is the rolling load of the first stand.

The actual tension force and operation output between the +-1st and i-th stands are monitored, and if the rolling load matches or exceeds the rolling load allowable band value Bi, and if the tension matches or exceeds the tension allowable band value 41, the rolling Mode switching command +Mi for switching from the first mode to the second mode shown in FIG. A mode return command for returning the operation mode from the second mode to the first mode when the rolling load is within the rolling load allowable band, the tension is within the tension allowable band, and the operating method can be returned to a non-saturated value. -Mi is sent to the operating system switching unit 304.

The monitor part 1o5 (excluding the monitor part 105) also receives the above-mentioned reduction operation priority command 10Y which instructs which control system, the reduction control system or the speed control system, is to execute tension control.
i, the above speed operation priority command -yt is sent to the operation system switching unit 104
and is sent to the tension control target value calculation unit i02.

The tension control target value calculation unit i02 calculates the above equation (3), but (a) when receiving the reduction operation priority command, calculates the unit tension ΔT(1)w according to (4) 2 below.

ΔT(i)=αIx(ΔQ(i)−ΔQ(1)O)+α
o(4)(b) If a speed operation priority command is received, ΔT(1) is calculated according to the following equation (5).

ΔT(+)=α2x(ΔQ(i))−Δ(Q(t)o)
4-αo(5) However, α. , α1, α2...The tension correction system monitor part 105 monitors the rolling load of the first stand 1, unlike the other monitor parts.

K is a coefficient multiplier which converts the output of the PI controller p1c into coefficients and inputs the result to the speed control device 1S of the first stand.

Next, the operation of this device will be explained.

The reference tension target TF(1) between each stand is set in advance for the rolled material to be rolled.

When the rolled material passes directly under one stand roll, the hardness change amount ΔQn is calculated and tracked by the original plate hardness change amount detection unit 10 for each information segment of 1/H of the pass between the first box and the two stands. That is, as the rolled material portion having the amount of change in hardness ΔQn moves between the first and second stands from the first section to the N2th section, the contents of the storage section corresponding to each section are sequentially rewritten, and during that time, the contents of the storage section corresponding to each section are rewritten at predetermined intervals. , the inter-stand representative hardness change amount calculation unit 201 is the hardness tracking information processing unit 200
Read the hardness change amount ΔQ2n from the representative hardness change amount ΔQ
Calculate (2) ・ This representative hardness change amount ΔQ (2) is the change amount limit + ΔQ
(2). If it is within the range, the tension target value calculation unit 203 outputs the reference tension target value TF(2), and if the reduction control system is currently selected, the reduction control device 2C of the second stand 2 will output the reference tension target value TF(2). In response to the tension target value 'l''F(2), the second
Controls the roll opening of the stand.

However, if the representative hardness change amount ΔQ(1) exceeds the change amount limiter ΔQ(1)o, the tension target value calculation unit 20
3 calculates and outputs the corrected tension target value 'l''f(2),
Thereafter, the rolling control device 2C of the second stand 2 receives this corrected tension target value 'l''f(2), and the tension of the rolled material is adjusted to Tf.
(2) Correct the roll opening so that it falls within the range of β2.

The representative hardness change amount ΔQ(2) is the change amount limit ±ΔQ(2
). When the tension target value calculation unit 203 returns to the inner state, the output of the tension target value calculation section 203 is switched to the reference tension target value TF(2).

Similarly, the tension between the 1-1 and 1-1 stands is determined by controlling the roll opening degree of the downstream stand, that is, the first stand, by the output of the tension filter section 103. However, regarding the first stand 1, in order to properly feed the rolled material to the line even when the priority is given to the rolling operation, the speed control device 1S has a control amount that is proportional to the control amount of the rolling control device 2C of the second stand. is given.

Further, for example, when the actual rolling load P3 of the third stand where the amount of hardness fluctuation decreases significantly and falls below the lower limit value -B of the rolling load allowable band, the monitor part 305 generates a mode switching command, and this Therefore, the operating system switching unit 304 is switched, and the corrected tension target value Tf(3) is input to the speed control device 1S of the first stand 1 and the second speed control device 2S, and the roll speeds of both stands are adjusted to a predetermined ratio. After that, tension control is performed by the speed control system of each stand on the upstream side (the first stand and the second stand) when the rolling load falls within the load tolerance band.

As a result, IJ bumps and shape deterioration of the rolled material due to a decrease in rolling load can be prevented.

The above description has been made regarding the tension control when the reduction operation priority command is given, but when the speed operation priority command is given, the tension control is performed by the speed control system. In this case, when the actual tension reaches the lower limit of the tension allowable band value, the corrected tension target is fixed and the monitor part i05 issues a mode switching command.
is switched, the corrected tension target value Tf(1) is given to the lowering control device of the first stand 1, and the tension control is switched to the lowering control system. Therefore, large tension fluctuations are prevented.

As described above, according to the present invention, the tension target value is not fixed but variable, and the amount of change in hardness from the reference hardness of the rolled material is detected at the line entry side, and this is tracked for the rolled material, and between each stand. Since the tension target value is corrected in accordance with the amount of change in hardness, even if rolled material with skid marks enters the line, the tension target value between each stand will not change due to skid marks, etc. The teeth are automatically corrected according to changes in hardness, preventing a sudden reduction in the rolling load applied to the rolled material, preventing the rolling material from narrowing down and slipping, and reducing tension fluctuations and plate thickness fluctuations. Stable operation can be achieved with less control than before.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the problems of the conventional tension control method, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a diagram for explaining the information trunking mode in the above embodiment. Figure 4 shows the operation of the above example of ability F! 11'
Figure 5 is a U mode table. i...Rolling stand IS...Speed side extension 11 device E+ IC/rolling down control device IX-Thickness 51 1T...Tension tension device 10-Original plate f...! Degree change detection part 10A... Plate thickness l - Racking certificate 10B - A 1 History J Bending change (Oil material H'r, l5100
...Tracking information processing section 11 section 10'l - representative between stands (fJ+1i massification"rjhhγflsi02, tension target 4M calculation section 103, tension target value filter section) 04...operation system switching section i05, monitor part 9 , ゛1 Applicant: Kobe R4J Co., Ltd.'')! Attorney Tsuji Kobayashi + A----------1-- (b) 10B-m--1-1-1-ゝ1N Procedural amendment (method) July 2nd, 1980 Patent Office Mr. Commissioner 1. Indication of the case Patent Application No. 49264 of 1982 2. Name of the invention Method for controlling tension of rolled material 3. Person making the amendment Relation to the case Patent applicant";l1llfi:'i:,i
,':l゛°l'1l(Jtll!lliselfi+i1personNo.252'(no2(riby1additionaladdress1-3-18υ-4Wakihama-cho,Chuo-ku,Kobe,Agent[shares]105 AddressTokyo 2-2-20, Nishi-Shimbashi, Miyakominato-ku, is corrected to read, ``No. 5 and 1 is a mode chart.''

Claims (1)

[Claims] (1) When controlling the rolling machine roll speed and roll opening degree of a cold rolling line to control the tension of the running rolled material to the tension target value, the unit length of the running rolled material is determined at the line entry side. Sequentially detecting the amount of change in hardness of the rolled material for each information section as one information section, tracking the amount of change in hardness as tracking information for the rolled material up to the final stand,
Between each stand, the inter-stand representative hardness change amount is calculated based on the above-mentioned tracking information, and the inter-stand standard tension target value set in advance is corrected in accordance with the inter-stand representative hardness change amount, and appropriate rolling is performed. A method for controlling the tension of a rolled material, characterized in that the tension of the rolled material is controlled to the corrected tension target value by a roll speed or a roll opening that enables