TWI515053B - Control apparatus for hot rolling line - Google Patents

Description

Control device for hot rolling production line

The present invention relates to a control device for a hot calendering line.

As a control device for the hot rolling line, it has been proposed to set the target temperature on the input side of the finishing mill, and to consider the temperature history and the speed pattern of the rolled material to change the setting of the rolling speed or the thickness of the roughened piece. Value. According to this control device, the temperature of the rolled material can be controlled to the target temperature on the output side of the finishing mill (for example, see Patent Document 1).

(Patent Document 1) Japanese Patent No. 4079098

However, when the continuous pressure delay is controlled by the control device, when the rolling speed on the output side of the finishing mill is fixed in consideration of the safety of the rolling in the variation of the thickness between the running, on the output side of the finishing mill, There is a case where the temperature of the rolled material after the thickness of the sheet cannot be changed is within the allowable range.

The present invention has been developed in order to solve the above-described problems, and an object of the present invention is to provide a control device for a hot rolling line which can reduce the rolling speed on the output side of the finishing mill during the change of the thickness of the running floor. The output side of the finishing mill controls the temperature of the rolled material after the thickness is changed within an allowable range.

The control device for the hot rolling line of the present invention includes a speed mode determining unit, and the leading material on the front end side of the rolled material becomes desired The temperature of the desired material determines the rolling speed mode when the preceding material passes through the finishing mill; the tracking portion grasps the position of the rolling material; the speed monitoring unit monitors the actual speed of the rolling material; and the speed change amount calculating unit The setting value of the rolling speed at the end portion of the preceding material and the setting value of the rolling speed at the end portion of the trailing material on the rear end side of the rolling material and the actual speed of the preceding material, the front end portion of the preceding material The temperature change amount of the end portion after the advance material is calculated in a desired range on the output side of the finishing mill; and the travel changing unit changes the end portion after the advance material is changed according to the speed change amount After the rolling speed in the finish rolling mill is fixed, the setting of the roll gap of the finishing mill and the setting of the tension between the rolls are changed so as to correspond to the desired thickness of the finishing material. The setting of the board thickness change during walking.

According to the present invention, the temperature of the rolled material after the thickness of the finishing mill can be controlled within the allowable range on the output side of the finishing mill while the rolling speed on the output side of the finishing mill during the change in the thickness of the running machine is fixed.

The embodiment for carrying out the invention will be described with reference to the drawings. In the drawings, the same reference numerals are given to the same or corresponding parts, and the repeated description is appropriately simplified or omitted.

Embodiment 1.

Fig. 1 is a configuration diagram of a hot rolling production line controlled by a control device for a hot rolling production line according to Embodiment 1 of the present invention.

In the upper part (a) of Fig. 1, 1 is a heating furnace. On the output side of the heating furnace 1, a roughing mill calender group 2 is disposed. On the output side of the roughing mill calender group 2, a finishing mill calender group 3 is disposed. Usually, the finishing mill calender group 3 has 5 to 7 finishing mills. On the output side of the finishing mill calender group 3, a coiler 4 is disposed. A cutter 5 is disposed between the finishing mill calender group 3 and the coiler 4.

Between the roughing mill press group 2 and the finishing mill extension group 3, the roughing mill output side thermometer 6 is disposed near the output side of the roughing mill calender group 2. Between the finishing mill calender group 3 and the cutter 5, a finishing mill output side thermometer 7 is disposed in the vicinity of the output side of the finishing mill calender group 3. An organic inter-stage sprayer 8 is disposed between each finishing stand of the finishing mill calender group 3.

In the hot calendering line, iron or non-ferrous flat steel slabs are withdrawn from the heating furnace 1. The flat steel blank is calendered to the target intermediate rolled sheet thickness by the roughing mill calender group 2. Thereafter, the rolled material is conveyed to the input side of the finishing mill calender group 3. Thereafter, the calendered material is calendered to a desired product sheet thickness using a finishing mill. Thereafter, the rolled material is taken up into a coil shape by the coiler 4.

The upper stage (a) of Fig. 1 shows a case where a series of leading material 9a and trailing material 9b are continuously rolled. That is, the front end side of the rolled material is the leading material 9a. The end side of the calendered material is the trailing material 9b. In this case, the roller gap of the finishing stand and the tension between the rolls can be changed during rolling. As a result, on the output side of the finishing mill calender group 3, the sheet thickness can be changed in the leading material 9a and the trailing material 9b.

Thereafter, the preceding material 9a is wound into a coil shape in one of the coilers 4. Thereafter, the cutter 5 is used to cut the periphery of the thickness change portion of the leading material 9a and the trailing material 9b without reducing the yield as much as possible. Thereafter, the trailing material 9b is wound into a coil shape on the other side of the coiler 4.

The middle section (b) of Fig. 1 is provided with a hot rolling line having a continuous casting apparatus 10. The continuous casting apparatus 10 extracts long flat steel embryos. The long flat steel germline is continuously calendered in a hot calendering line.

The lower stage (c) of Fig. 1 is provided with a hot rolling line having the joining device 11. The joining device 11 is disposed on the input side of the finishing mill calender group 3. The joining apparatus 11 is a joining of a calendering material that is calendered to the intermediate rolled sheet thickness. As a result, a series of calendering materials can be continuously calendered using the finishing mill calender group 3.

Next, the control device of the hot rolling production line will be described.

Fig. 2 is a block diagram showing a control device of the hot rolling line of the first embodiment of the present invention.

As shown in FIG. 2, the control device includes a setting calculation unit 12, a preceding material setting storage unit 13, a speed mode determination unit 14, a subsequent material setting storage unit 15, a travel changing unit 16, a tracking unit 17, and a speed monitoring unit 18. The speed change amount calculation unit 19 and the speed change timing (timing) determination unit 20.

The setting calculation unit 12 has a working condition such as a target thickness of a rolling material on the output side of the finishing mill calender group 3 and a target temperature (FDT (Finishing Delivery Temperature) target value), and uses a model. At least at the end, the central portion, and the rear end portion of the rolling material, the function of the schedule is determined. For example, in order to The target plate thickness is obtained on the output side of the finishing mill calender group 3, and the roll gap of the finishing stand or the tension between the rolls is determined. Further, on the output side of the finishing mill calender group 3, the rolling speed at which the rolling material passes through the finishing mill calender group 3, the flow rate between the inter-machine sprayers 8, and the like are determined so that the temperature of the rolled material becomes the FDT target value. At this time, the rolling speed is determined so as not to exceed the limit value of the rolling torque.

The preceding material setting storage unit 13 has a function of storing each set value of the preceding material 9a calculated by the setting calculating unit 12 in advance, and sending each set value to the hot rolling production line at a predetermined timing.

The speed mode determining unit 14 has a function of determining the speed mode of the entire length of the rolled material of the preceding material 9a based on the rolling speed and the working condition calculated by the setting calculating unit 12.

The trailing material setting storage unit 15 has a function of storing each set value of the trailing material 9b calculated by the setting calculation unit 12.

The travel changing unit 16 has a set value of the preceding material 9a stored in the preceding material setting storage unit 13 and a set value of the subsequent material 9b stored in the subsequent material setting storage unit 15, thereby determining the rolling in the finishing mill. The output side of the cluster 3 functions as a set value of the roller gap of the finishing stand and the tension between the rolls required for changing the thickness of the running floor.

The tracking unit 17 has a function of performing tracking tracking in which the position of the rolled material is accurately grasped in the hot rolling production line.

The speed monitoring unit 18 has a speed calculated by sequentially monitoring a pulse signal from an encoder generated from the number of rotations of the roller of the finishing mill or a rolling material directly measured from an ultrasonic velocity meter or the like. The function of speed.

The speed change amount calculation unit 19 has the end portion 9a after the actual temperature (FDT actual value) of the end portion before the trailing material 9b on the output side of the finishing mill calender group 3 is within the allowable range. The most appropriate speed change function. Specifically, the speed change amount calculation unit 19 stores the set value of the rolling speed at the end portion of the leading material 9a stored in the preceding material setting storage unit 13 and stores it in the front end of the trailing material 9b of the trailing material setting storage unit 15. The set value of the rolling speed of the portion and the actual speed of the leading material 9a at the current time monitored by the speed monitoring unit 18 are used to calculate the optimum speed change amount.

The speed change timing determining unit 20 has a function of determining the most appropriate timing when the rolling speed is changed based on the speed change amount calculated by the speed change amount calculating unit 19.

Next, a method of determining the FPC (Flying Product Change) point at which the change in the thickness of the floor is started will be described using FIG.

Fig. 3 is a view for explaining parameters required when the control device for the hot rolling production line according to the first embodiment of the present invention changes the thickness of the running between the steps.

In Fig. 3, A is a set calculation point at the end of the trailing material 9b. L _bef (m) is the length of the leading material 93 on the output side of the finishing mill calender group 3. L _B (m) is the distance required to change the thickness of the floor between walks. L _C (m) is the margin distance. The distance L _B and the margin distance L _C required for the change in the thickness of the walk between the walks are defined as the distance on the output side of the finish rolling mill group 3 by the layer value of each plate thickness.

When the mass of the leading material 9a is M (kg), the target width of the leading material 9a is w (m), the target thickness of the leading material 9a is h ₁ (m), and the trailing material 9b is used. When the target thickness is h ₂ (m) and the density of the rolled material is ρ (kg/m ³ ), the length L _{bef of the} leading material 9a is calculated by the following formula (1).

When the thickness of the intermediate rolling stock which is the target value of the thickness of the input side of the finishing mill calender group 3 is H (m), the length L _H (m) of the leading material 9a on the input side of the finishing mill calender group 3 It is calculated by the following formula (2).

At this time, on the input side of the finishing mill group 3, the length L _HC (m) of the rolled material from the front end of the preceding material 9a to the FPC point is calculated by the following formula (3).

Next, a method of determining the speed change amount and a method of correcting the rolling speed mode will be described using FIG.

Fig. 4 is a view for explaining a speed pattern calculated by the control device of the hot rolling line of the first embodiment of the present invention. The horizontal axis of Fig. 4 is time. The vertical axis of Fig. 4 is the rolling speed.

21 is the calendering speed mode at the time of the previous setting calculation. 22 is the rolling speed of the end portion of the leading material 9a calculated by the setting calculation unit 12. 23 is the rolling speed of the end portion of the trailing material 9b calculated by the setting calculation unit 12. The actual speed at which the 24 system changes in order to achieve the FDT target value. 25 is the rolling speed of the current time point. Δv is the speed change amount. S _tail is the time required for the speed change. 26 is the calendering speed mode after the change.

When the set value (m/s) of the rolling speed 22 at the end portion of the leading material 9a is set to v _tail ^bef , and the set value (m/s) of the rolling speed 23 at the end portion of the trailing material 9b is set to v _head ^Aft , when the rolling speed 25 (m/s) at the current time is v ^act and the gain (gain) is α , the speed change amount Δv (m/s) is expressed by the following formula (4). Calculation. At this time, the adjustment gain α is set in advance as a working condition.

[Expression 4] Δ v = ( v _head ^aft - v _tail ^bef ) + α ( v _tail ^bef - v ^act ) (4)

Next, a limit check of the rolling speed changed by the speed change amount Δv is performed. Specifically, it is determined whether or not the following formula (5) holds, based on the rolling speed allowable upper limit value v _max . At this time, the rolling speed allowable upper limit value _vmax is determined in advance as the layer table value distinguished for each plate thickness.

[Expression 5] v _max <Δ v + v _tail ^bef (5)

When the equation (5) is satisfied, the speed change amount Δv can be corrected by the following formula (6).

[Expression 6] Δ v = v _max - v _tail ^bef (6)

Further, calendering speed v _min allowable limit value as a reference, and determined the following equation (7) is established. In this case, the lower limit of the allowable rolling speed v _min, lines can be determined in advance as table values do not distinguish between the thickness of each layer.

[Expression 7] v _min >△ v + v _head ^aft (7)

When the expression (7) is satisfied, the speed change amount Δv can be corrected by the following formula (8).

[Expression 8] Δ v = v _min - v _head ^aft (8)

Next, in order to prevent a sudden increase in speed, the limit check of the speed change amount Δv itself is performed. Specifically, the speed change amount allowable upper limit value Δv _max and the speed change amount allowable lower limit value Δv _{min are used} as a reference, and it is determined whether or not the following formula (9) holds. In this case, the speed change amount allowable upper limit value Δv _max and the speed change amount allowable lower limit value Δv _min can be determined in advance as the layer table value for each plate thickness.

Second, calculate the time s _tail required for the speed change. Specifically, when the acceleration rate (m/s ² ) is a _tail and the remaining time (s) is χ _tail , the time s _tail required for the speed change is calculated by the following formula (10). . At this time, the acceleration rate a _tail and the margin time χ _tail can be determined in advance as the layer table value for each board thickness distinction.

[Expression 10]

The calendering speed mode is corrected based on the above calculation results. Specifically, in order to maintain the stability of rolling during the change in the thickness of the road between the steps, the change of the rolling speed mode is started before the change in the thickness of the running floor is earlier than before the time S _tail required for the speed change. As a result, the changed rolling speed mode 26 is fixed until the change in the thickness of the running floor is started.

Next, the speed change timing distance will be described using FIG.

Fig. 5 is a view for explaining the timing at which the speed of the control device of the hot rolling production line according to the first embodiment of the present invention is changed.

The F1 system is disposed on the finishing stand closest to the side of the roughing mill calender group 2. B is the FPC point. C is the cutting point of the leading material 9a and the trailing material 9b. D is a set calculation point at the end of the trailing material 9b. E is the speed change timing point.

L _RDT-F1 is the distance between the roughing mill output side thermometer 6 and the finishing stand F1. L _FPC is the distance between the FPC point B and the cut point C. The L _aft ^head is the distance between the cut point C and the setting point D of the end portion of the trailing material 9b. L _spt is the distance between the FPC point B and the speed change timing point E. L _chspt is the speed change timing distance.

The distance L _RDT-F1 is determined in advance by the configuration of the rolling mill. Usually, since the distance L _RDT-F1 is 20 m or more, there is a sufficient distance for the change in the rolling speed.

The distance F _{FPC is such} that the target thickness of the leading material 9a is h ₁ , the target thickness of the trailing material 9b is h ₂ , the intermediate rolled thickness is H, and the thickness of the running board is changed. When the distance is set to L _B and the remaining distance is set to L _C , it is calculated by the following formula (11).

The distance from the L _aft ^head can be predetermined as a layer value depending on the thickness of the plate.

The distance L _spt is calculated by the following formula (12) when the current rolling speed is v ^act , the acceleration rate is a _tail , and the time required for the speed change is s _tail .

The speed change timing distance L _chspt is expressed as the distance from the finishing mill point F1 when the set calculation point D of the front end material 9b reaches the roughing mill output side thermometer 6 . Specifically, the speed change timing distance L _chspt is calculated by the following formula (13).

[Expression 13] L _chspt = L _{RDT-F 1} -( L _aft ^head + L _FPC + L _spt ) (13)

Next, the operation of the control device will be described using FIG.

Fig. 6 is a flow chart for explaining the operation of the control device for the hot rolling line of the first embodiment of the present invention.

First, in step S1, the length of the rolled material, the cutting point, and the FPC point are determined in advance before the leading material 9a is taken out from the heating furnace 1. It Then, the process proceeds to step S2, and the leading material 9a is taken out from the heating furnace 1. At this time, the setting calculation unit 12 must perform at least one setting calculation of the preceding material 9a and the subsequent material 9b.

Thereafter, the process proceeds to step S3, and the front end portion of the preceding material 9a reaches the roughing mill output side thermometer 6. At this time, the setting calculation unit 12 may perform the setting calculation of the preceding material 9a again based on the actual temperature of the front end portion of the preceding material 9a measured by the roughing mill output side thermometer 6.

Thereafter, the process proceeds to step S4, and the front end portion of the preceding material 9a reaches the finishing mill output side thermometer 7. After arrival, the calendering speed is corrected based on the error between the actual FDT value and the FDT target value. As a result, the temperature of the leading material 9a is maintained at the FDT target value on the output side of the finishing mill calender group 3.

Thereafter, the process proceeds to step S5, and the end portion of the trailing material 9b is taken out from the heating furnace 1. At this time, the setting calculation unit 12 performs the setting calculation of the trailing material 9b again. The result of the setting calculation is stored in the trailing material setting storage unit 15. Further, the speed change amount calculation unit 19 calculates the speed change amount Δv.

Thereafter, the process proceeds to step S6, and the end portion of the trailing material 9b reaches the roughing mill output side thermometer 6. At this time, the setting calculation unit 12 performs the setting calculation of the trailing material 9b again based on the actual temperature of the end portion of the trailing material 9b measured by the roughing mill output side thermometer 6. At this time, the speed change amount calculation unit 19 calculates the speed change amount Δv again.

Thereafter, the process proceeds to step S7, and the speed change timing determining unit 20 calculates the speed change timing distance _Lchspt . The speed change timing distance L _chspt is sent to the travel changing unit 16.

Thereafter, the process proceeds to step S8, and the tracking unit 17 grasps that the speed change time point E has reached the finishing stand F1. At this time, the travel changing unit 16 starts the change of the rolling speed.

Thereafter, the process proceeds to step S9, and the change in the rolling speed is completed. Thereafter, the tracking unit 17 grasps that the FPC point B has reached the finishing stand F1. At this time, the walking change unit 16 starts the change in the thickness between the steps. As a result, the thickness of the rolled material is changed on the output side of the finishing mill calender group 3.

Thereafter, the process proceeds to step S10, and the tracking unit 17 grasps that the cutting point C has reached the cutting machine 5. At this time, the cutter 5 cuts the rolled material at the cutting point C.

Next, the temperature control history of the rolled material when the rolling speed is changed by the control device will be described using Fig. 7 .

Fig. 7 is a timing chart for explaining the temperature control history of the rolled material by the control device of the hot rolling line of the first embodiment of the present invention.

In Fig. 7, 27 is the calendering speed. 28 is the FDT target value. 29 is the allowable upper limit of the FDT. 30 is the allowable lower limit of FDT. 31 is the actual value of FDT.

As shown in Fig. 7, in the initial state, the rolling speed 27 is fixed. As a result, the FDT actual value 31 is consistent with the FDT target value 28. Thereafter, the change of the rolling speed 27 is started. As a result, the FDT actual value 31 will rise. Thereafter, the rolling speed 27 becomes fixed. After that, the board thickness change was started. As a result, the FDT actual value 31 will fall without exceeding the FDT allowable upper limit value 29.

After that, the board thickness change is completed. As a result, the actual value of FDT will change. It is fixed without falling below the FDT allowable lower limit. When the trailing material 9b is Dcon (Down coileron: when it reaches the coiler), the rolling speed 27 is restarted again, and as a result, the FDT actual value 31 coincides with the FDT target value 28.

According to the first embodiment described above, the rolling speed of the end portion of the preceding material 9a can be changed and the rolling speed of the leading material 9a can be changed to the desired range after the material 9b on the output side of the finishing mill calender group 3 is set. After fixing, the thickness of the board between the walks is changed. Therefore, the temperature of the trailing material 9b can be controlled within the allowable range on the output side of the finishing mill while fixing the rolling speed on the output side of the finishing mill during the change of the thickness of the running board. As a result, the quality of the entire length of the rolled material can be ensured.

Further, by appropriately setting the speed change timing distance L _chspt , the length of the FDT actual value deviated from the FDT target value can be shortened at the end portion of the preceding material 9a.

Further, there is a case where the order of step S4 and step S5 of Fig. 6 is changed by the length of the rolled material. However, even if the order is changed, there is no impact.

Embodiment 2.

Fig. 8 is a block diagram showing the main part of a control device for a hot rolling production line according to a second embodiment of the present invention. The same or equivalent portions as those in the first embodiment are denoted by the same reference numerals and will not be described.

As shown in FIG. 8, the control device includes a deviation calculating unit 32, a DB (Dead Band) unit 33, a control amount calculating unit 34, an actuator output determining unit 35, and a limiting unit 36.

The deviation calculating unit 32 has a function of calculating the deviation between the FDT actual value and the FDT target value with respect to the preceding material 9a. When the FDT actual value is FDT ^act and the FDT target value is FDT ^tar , the deviation ΔT is calculated by the following formula (14).

[Expression 14] △ T = FDT ^act - FDT ^tar (14)

Further, when the end portion of the trailing material 9b reaches the finishing mill output side thermometer 7, the FDT target value is changed to be stored in the trailing material 9b set value storage function.

The DB unit 33 has a function of avoiding excessive control by providing a non-sensing area. The DB unit 33 changes the DB threshold value from the start speed change based on the information from the travel changing unit 16 until the change in the thickness of the walk is completed.

When the FDT allowable upper limit deviation (degC) is ΔT _FD ^UL and the DB upper limit gain is β ^UL , the DB upper limit threshold T _DB ^UL is calculated by the following formula (15). At this time, the DB upper limit is determined in advance by the gain β ^UL to be the layer table value of the plate thickness distinction.

[Expression 15] T _DB ^UL = β ^UL △ T _FD ^UL (15)

When the FDT allowable lower limit deviation (degC) is ΔT _FD ^LL and the DB lower limit gain is β ^LL , the DB lower limit threshold T _DB ^LL is calculated by the following formula (16). At this time, the DB lower limit gain β ^LL can be determined in advance as the layer table value of the board thickness distinction.

[Expression 16] T _DB ^LL = β ^LL △ T _FD ^LL (16)

Therefore, the deviation ΔT is corrected by the following formula (17).

[Expression 17] If T _DB ^LL < △ T < T _DB ^UL , Δ T =0 (17)

The control amount calculation unit 34 has a function of calculating a control change amount of the actuator by applying a PID (Proportional Integral Differential) calculation method or the like based on the corrected deviation ΔT.

The actuator output determination unit 35 has a function of determining the output of the actuator based on the control change amount calculated by the control amount calculation unit 34 and the current output value. The output of the actuator can be determined by operating conditions or mill restrictions. Typically, the output of the actuator is the flow rate or calendering speed of the inter-machine sprayer 8.

The restriction portion 36 has a set value of the end portion of the trailing material 9b of the trailing material setting storage portion 15 in addition to the set value of the advance material 9a itself in consideration of the preceding material setting storage portion 13, and determines the actuator. The function of limiting the range of output.

Next, the case where the output of the actuator is the flow rate of the inter-machine sprayer 8 will be described. In this case, when the flow rate allowable lower limit value (%) of the preceding material 9a is ^Wbef_LL and the flow rate allowable upper limit value (%) of the leading material 9a is ^Wbef_UL , the flow rate W can be obtained by the following (18) to limit. In this case, the flow rate of the first material 9a allowable lower limit value ^W bef_Lt, the flow rate of the first material 9a allowable upper limit ^W bef_UL, lines determined by operating conditions.

[Expression 18] W ^bef_LL < W < W ^bef_UL (18)

In addition, when the set flow rate (%) of the front end portion of the trailing material 9b is W _head ^aft and the flow rate change allowable amount (%) at the end portion of the leading material 9a is ΔW _te , the flow rate W is also (19) to limit. At this time, the set flow rate W _head ^aft at the end of the trailing material 9b is calculated by setting calculation. The flow rate change allowable amount ΔW _te at the end portion of the leading material 9a can be determined in advance as the layer table value for the thickness difference.

[Expression 19] W _head ^aft - △ W _te < W < W _head ^aft + △ W _te (19)

Next, the case where the output of the actuator is the rolling speed will be described. In this case, when the speed allowable lower limit value of the preceding material 9a is ^Vbef_LL and the speed allowable upper limit value of the preceding material 9a is ^Vbef_UL , the rolling speed v is ^expressed by the following formula (20). limit. At this time, the speed of the preceding material 9a allowable lower limit value ^V bef_LL, the speed of the preceding material 9a allowable upper limit of ^V bef_UL, lines determined by operating conditions.

[Expression 20] v ^bef_LL < v < v ^bef_UL (20)

In addition, when the set speed of the end portion of the trailing material 9b is v _head ^aft (m/s), the speed allowable lower limit change rate is δ ^LL , and the speed allowable upper limit change rate is δ ^UL , the calendering speed is used. v can also be limited by the following formula (21). At this time, the set speed v _head ^aft of the front end portion of the trailing material 9b can be calculated by setting calculation. The speed allowable lower limit change rate δ ^LL and the speed allowable upper limit change rate δ ^UL can be determined in advance as the layer table value of the plate thickness distinction.

[Formula 21] v _head ^aft (1- δ ^LL )< v < v _head ^aft (1+ δ ^UL ) (21)

Next, the temperature control history when the output of the actuator is limited will be described using FIG.

Fig. 9 is a timing chart for explaining the temperature control history of the rolled material by the control device of the hot rolling line of the second embodiment of the present invention.

In Fig. 9, 37 is the calendering speed. 38 is the flow rate of the sprayer 8 between the machines. 39 is the DB upper limit value set by the sum of the FDT target value FDT ^tar and the DB upper limit threshold T _DB ^UL . 40 is the DB lower limit value set by the sum of the FDT target value FDT ^tar and the DB lower limit threshold T _DB ^LL . 41 is the actual value of FDT.

As shown in Fig. 9, the DB upper limit value 39 is increased until the change in the thickness of the running board is started after the start of the change of the rolling speed 37. In this case, when the FDT actual value 41 exceeds the DB upper limit value 39, the deviation ΔT is higher than the DB threshold. Therefore, the actuator output determining unit 35 increases the flow rate 38. As a result, the fluctuation of the actual value 41 of the FDT is suppressed.

Thereafter, the change in the rolling speed is completed, and the change in the thickness between the running starts is started. As a result, the FDT actual value 41 will drop. Therefore, the actuator output determining unit 35 reduces the flow rate 38. As a result, the FDT actual value 41 is consistent with the FDT target value 28 before the trailing material 9b is Dcon.

According to the second embodiment described above, the limit range of the output of the actuator can be set. At this time, the non-sensing area of the DB unit 33 is enlarged. Therefore, the output of the actuator is limited.

When the output of the actuator is set to the inter-machine sprayer 8, the change in the flow rate can be suppressed. As a result, the front end of the trailing material 9b can be suppressed. The case where the actual value of FDT is lowered. Further, it is possible to prevent the rolling of the end portion of the trailing material 9b from becoming unstable. Further, in this case, the rolling speed which is changed so that the temperature of the end portion before the material 9b is changed to the desired range after the output side of the finishing mill calender group 3 can be used.

When the output of the actuator is set to the rolling speed, it is possible to suppress the rolling speed which is changed in such a manner that the temperature of the end portion before the material 9b becomes the desired range after the output side of the finish rolling mill group 3 is Offset situation.

1‧‧‧heating furnace

2‧‧‧Rough rolling mill calender

3‧‧‧ Finishing mill calender

4‧‧‧Winding machine

5‧‧‧Cutting machine

6‧‧‧Roughing mill output side thermometer

7‧‧‧ Finishing mill output side thermometer

8‧‧‧Machine sprayer

9a‧‧‧ Leading materials

9b‧‧‧After materials

10‧‧‧Continuous casting device

11‧‧‧Joining equipment

12‧‧‧Set Calculation Department

13‧‧‧Provisional material setting storage

14‧‧‧Speed Mode Decision Department

15‧‧‧After the material setting storage department

16‧‧‧Travel Change Department

17‧‧‧ Tracking Department

18‧‧‧Speed Monitoring Department

19‧‧‧Speed Change Calculation Department

20‧‧‧Speed Change Timing Decision Department

21, 26‧‧‧Deceleration mode

22, 23, 25, 27, 37 ‧ ‧ calendering speed

24‧‧‧ actual speed

28‧‧‧FDT target value

29‧‧‧FDT allowable upper limit

30‧‧‧FDT allowable lower limit

31‧‧‧FDT actual value

32‧‧‧Deviation Calculation Department

33‧‧‧DB Department

34‧‧‧Control Quantity Calculation Department

35‧‧‧Actuator Output Decision Department

36‧‧‧Restrictions

38‧‧‧ flow

39‧‧‧DB upper limit

40‧‧‧DB lower limit

41‧‧‧FDT actual value

A‧‧‧Set calculation point

B‧‧‧FPC point

C‧‧‧ cut point

D‧‧‧Set calculation points

E‧‧‧Speed change timing point

F1‧‧‧ finishing mill

Fig. 1 (a) to (c) are views showing the configuration of a hot rolling line controlled by a control device for a hot rolling line of the first embodiment of the present invention.

Fig. 2 is a block diagram showing a control device of the hot rolling line of the first embodiment of the present invention.

Fig. 3 is a view for explaining parameters required for changing the thickness of the traveling between the control devices of the hot rolling line according to the first embodiment of the present invention.

Fig. 4 is a view for explaining a speed pattern calculated by the control device of the hot rolling line of the first embodiment of the present invention.

Fig. 5 is a view for explaining the timing at which the speed of the control device of the hot rolling production line according to the first embodiment of the present invention is changed.

Fig. 6 is a flow chart for explaining the operation of the control device for the hot rolling line of the first embodiment of the present invention.

Fig. 7 is a timing chart for explaining the temperature control history of the rolled material by the control device of the hot rolling line of the first embodiment of the present invention.

Figure 8 is a control device for the hot rolling production line of the second embodiment of the present invention. The block diagram of the main part.

Fig. 9 is a timing chart for explaining the temperature control history of the rolled material by the control device of the hot rolling line of the second embodiment of the present invention.

12‧‧‧Set Calculation Department

13‧‧‧Provisional material setting storage

14‧‧‧Speed Mode Decision Department

15‧‧‧After the material setting storage department

16‧‧‧Travel Change Department

17‧‧‧ Tracking Department

18‧‧‧Speed Monitoring Department

19‧‧‧Speed Change Calculation Department

20‧‧‧Speed Change Timing Decision Department

Claims (4)

A control device for a hot rolling line, characterized in that the speed mode determining unit is configured to determine a rolling speed mode when the preceding material passes through the finishing mill so that the leading material on the front end side of the rolling material has a desired temperature; The tracking unit grasps the position of the rolling material; the speed monitoring unit monitors the actual speed of the rolling material; and the speed change amount calculating unit sets the setting value of the rolling speed at the end portion of the preceding material and the rear end side of the rolling material. The set value of the rolling speed at the front end of the trailing material and the actual speed of the preceding material are calculated in such a manner that the temperature of the front end portion of the trailing material becomes within a desired range on the output side of the finishing mill. After that, the amount of change in the speed of the end portion and the movement changing unit are fixed after the end portion is changed by the rolling speed at the end of the finishing mill after the advance amount is changed, and the subsequent material is desired. In the manner of thickness, the setting of the roller gap of the aforementioned finishing mill and the foregoing Set tension between the son is changed to correspond to the thickness change between walk setting. The control device for the hot rolling line according to claim 1, further comprising: an actuator output determining unit that has a desired temperature at an end portion of the leading material on the output side of the finishing mill In the internal mode, after the change of the rolling speed when the end portion of the preceding material is passed through the finishing mill, the change is controlled until the change in the thickness of the running board is completed. The amount of control of the actuator that fixes the temperature of the calendering material on the output side of the finishing mill described above. The control device for the hot rolling line according to the second aspect of the invention, further comprising: a deviation calculating unit that calculates a deviation between an actual temperature of the rolling material on the output side of the finishing mill and a target temperature; When the deviation falls within the threshold value, it is assumed that there is no such deviation; the control amount calculation unit calculates the control amount of the actuator based on the deviation; and the restriction unit determines the limitation range of the output of the actuator The DB portion is configured to increase the threshold value after the change of the rolling speed at the end of the preceding material through the finishing mill until the change in the thickness of the running board is completed, and the actuator output determining unit is The control amount of the aforementioned actuator is determined within the control range of the output of the aforementioned actuator. The control device for the hot rolling line according to the second or third aspect of the invention, wherein the actuator output determining unit controls the inter-machine sprayer disposed between the finishing stands constituting the finishing mill The flow rate is used as the control of the aforementioned actuator.