JPS6393418A - Automatic reduction gear for rolling mill - Google Patents

Abstract

PURPOSE:To automatically perform a speed reduction with high accuracy at the time of rolling a defect point by decelerating so that a target speed is obtained through a speed control means based on a bit of positional information of a stock to be rolled to be decelerated and a bit of information of target rolling speed after decelerated, furthermore, providing a means to correct the speed reduction rate. CONSTITUTION:On a reversible rolling mill, a position storing means 10 for the stock to be rolled, a target speed storing means 11 after decelerating, a speed correcting means 13 are provided. In confronting to coincidence of the position information from the position storing means 10 and the stock to be rolled to be decelerated, the rolling speed is reduced to be the target speed of the target speed storing means 11 through the speed control means 12. At the time of decelerating, the real speed reduction rate is corrected to become the target rate of speed reduction through the speed control means 13. By this apparatus, the speed reduction can always be finished at the time of reaching the defect point of the rolling material on the rolling stand.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an automatic speed reduction device for a rolling mill, and particularly relates to an improvement in an automatic speed reduction device for a rolling mill that controls the speed reduction of a reversible rolling mill based on positional information of a rolled material.

[Conventional technology]

When a material to be rolled containing defects in the material caused by welding points, previous processing, etc. is rolled at high speed by a cold rolling mill, inconveniences such as breakage of the material called so-called plate breakage may occur. In addition, in a reversible cold rolling mill, the rolling mill is alternately
The material to be rolled is reciprocated by reversing the rolling direction and gradually rolled to a desired thickness. In such reversible rolling, for example, in the first pass, the operator manually uses the rolling instruction sheet attached to the coil of each rolled material to place the point corresponding to the defective point in the material immediately before it is bitten by the stand. The rolling mill is slowed down. In addition, in the winding machine on the exit side of the rolling mill, when the defective point is wound around the winding machine, the operator inserts a marking paper or the like between the coils to mark the deceleration point for the next pass. However, this method has a problem in that it requires an operator to operate the rolling mill and an operator to sandwich the paper between the coils. Another problem is that it is extremely dangerous to manually insert paper marks into the coils. On the other hand, for example, in Japanese Patent Application Laid-Open No. 54-83659, position information of the rolled material whose rolling speed should be reduced is stored,
Based on this stored position information, the coiled position of the rolled material to be decelerated is calculated according to the elongation of the rolled material due to the rolling reduction rate in the rolling stand, and this calculation result and the position of the rolled material to be rolled are calculated. An automatic speed reduction device has been proposed that reduces the speed of a mill motor that drives a rolling stand in response to the coincidence of the rolling stand. In such an automatic deceleration device, a method of registering the position on the coil of the portion to be decelerated on the second bus in the first pass will be explained. First, the number of revolutions of the work roll is determined by a counter that detects the number of revolutions of the work roll, and the length Ll of the coil after one pass rolling is calculated from this number of revolutions, the advance rate, and the diameter of the work roll. Furthermore, each time a defective point on the coil reaches the rolling stand, the current length of the coil from the tip of the coil to the defective point, 121, is stored in the memory using a push button switch. In this way, the position (deceleration point) on the coil of the part to be decelerated on the next bus is memorized. Next, a method for controlling the deceleration of the rolling speed corresponding to the deceleration point in the next pass will be explained. First, the coil length Ll after the first pass rolling and the length 1 from the tip of the coil at the deceleration point are determined by using the rolling reduction ratio of the second pass, and the plate length L1' jump 1' after the two-pass rolling. Convert to . During the second bus rolling, the rolling direction is opposite to that during the first pass rolling, so the length from the tip of the coil to the deceleration point of the second pass is LL'-J21'. From this value LL'-J21', the rolling length of the second pass, which is determined from the work roll rotation speed, work roll diameter, and advancement rate in the second pass, is subtracted. Further, the length of the coil required to complete deceleration by the time the deceleration point reaches the rolling stand is determined from the deceleration rate of the rolling stand. Next, the coil length required to complete this deceleration is compared with the above-mentioned subtraction result. In this comparison, when the two match,
Outputs a deceleration command to the work roll drive unit. In this way, deceleration control in the second pass is performed. Therefore, the automatic speed reduction device in the above proposal can automatically reduce speed when rolling the material to be rolled at defective points, save labor, and eliminate the dangerous work of sandwiching marking paper, etc. be able to.

[Problems to be solved by the invention]

However, since the automatic speed reducer does not have the ability to set the speed of the material to be rolled after deceleration, the defective point is always rolled at a constant speed regardless of the size of the defective point. Therefore, it is not possible to set the rolling speed according to the state of the defective point, which may result in excessive or insufficient deceleration. In addition, in order to ensure that the deceleration occurs when the defective point reaches the rolling stand, the deceleration rate calculated to calculate the deceleration distance must be the worst value of the fluctuations in the deceleration rate of the actual work roll drive motor, that is, the lowest. It is necessary to use a deceleration rate. Therefore, if the actual deceleration rate is higher than the calculated deceleration rate,
Rolling is started at a low speed from before the defect point. Therefore, since parts that do not require low speed rolling are also low speed rolled, there is a problem that work efficiency is reduced.

OBJECT OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is capable of accurately finishing deceleration at a pre-registered position at which the rolled material should be decelerated, and It is an object of the present invention to provide an automatic speed reduction device for a rolling mill that can arbitrarily set the speed in advance, eliminate excessive deceleration and insufficient deceleration, and perform appropriate deceleration.

[Means to solve the problem]

The present invention is an automatic reduction device for a rolling mill that controls the reduction of the rolling speed of a reversible rolling mill based on information on the position of the material to be rolled, as shown in Fig. 1. -0, a target speed storage means 11 for storing the target speed after deceleration, and a position from the position storage means 10.
a speed control means 12 that decelerates the rolling speed to a target speed of the target speed storage means 11 in response to coincidence of the 1'i information and the position of the rolled material to be decelerated; The above object is achieved by including a speed correction means 13 that corrects the deceleration rate of the actual rolling speed so that it becomes the target deceleration rate during deceleration by the control means 12.

[Effect]

In the present invention, a target rolling speed after deceleration at that position is stored in correspondence with a position on the coil to be decelerated, and the rolling speed is decelerated to the target rolling speed in the next pass of rolling. As a result, depending on the operator's judgment based on the condition of defects, etc., where the rolling speed should be reduced,
The rolling speed after deceleration can be set arbitrarily. Therefore, it is possible to efficiently use the rolling speed for defective points where there is a risk of material breakage, etc., and the rolling speed for checking the state change of the defective points in the next bus. Therefore, necessary and sufficient deceleration control of the rolling speed can be performed in response to the condition of defect points and the like. Further, during deceleration by the speed control means, the deceleration rate of the actual rolling speed is corrected to become the target deceleration rate. This allows the deceleration to be completed exactly when a defective point requiring deceleration comes to the rolling stand. Therefore, there is no need to perform low-speed rolling on an extra section, and deceleration rolling can be performed efficiently. That is, conventionally, the deceleration rate of the mill motor used when determining the plate length required for deceleration was determined by the worst value of the deceleration rate fluctuations of the actual mill motor, that is, the lowest deceleration rate, depending on the rolling material and rolling condition. I try to use it. This is to ensure that deceleration is completed when the defective point reaches the rolling stand. Therefore, deceleration will not be completed beyond the defect point, but on the other hand, if the deceleration rate changes in the direction of increasing, deceleration will be completed with a shorter deceleration distance than the calculated result. . Therefore, in the past, a longer plate length than necessary was rolled at a low speed, making efficient deceleration rolling impossible, but the present invention can solve this problem.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIGS. 2 to 4, the rolled material 1
The method of the present invention is applied to a rolling mill 18 that reversibly rolls 6. In addition, numerals 19 and 20 in the figure are reels for winding and unwinding the material to be rolled 16, 22 is a work roll,
23 indicates a mill motor. As shown in FIG. 1, the automatic speed reduction device of this embodiment includes a position recording means 10, a target speed storage means 11, a speed control means 12, and a speed correction means 13. As shown in FIG. 2, the position storage means 10 includes a pulse oscillator 24 that is linked to the rotation of the reel 19, and a counter 26 that adds the pulses from the pulse oscillator 24 to count the number of rotations of one reel. , determines the start of winding of the rolled material 16 on one reel, and at the start of winding, the pulse counter 26f! : A winding start determination circuit 28 that sets the value to zero, a defect registration button 3o that is pressed by the operator when the defective point of the material to be rolled 16 comes to a predetermined position near the rolling mill 18, and this defect registration button 3o. ．． When the button 3o is turned on, the pulse counter 26
a gate 32 that outputs a count value of , to a turn number corrector 34 to be described later; and a turn number corrector 34 that converts the count value from this gate 32 into the number of turns when the defective point is located at the position of the work roll 22. , and a registration position memory 36 for storing the number of turns from the turn number corrector 34, each having a length of t/4. The winding start determination in the winding start determination circuit 28 is performed based on sequence signals such as rolling direction switching. The target speed storage means 11 includes a speed setter 38 for setting a speed, a deceleration speed registration button 40, and a speed set by the speed setter 38 in a registered speed memory 44 when the deceleration speed registration button 40 is pressed. Gate 4 outputs the speed
2, and a registered speed memory 44 that stores the output value from this gate 42. In addition, as the target speed storage means 11, several types of deceleration speed registration buttons are installed, and by selecting and turning on this registration button, the stored deceleration speed can be changed. Good too. As shown in FIG. 3, the speed control means 12 includes the counter 26 which subtracts the pulse from the pulse oscillator 24 from the number of winding turns of the previous pass and counts the number of turns N remaining on the reel 19 during rewinding. , the reel diameter setting device 46 for setting the reel diameter, the plate thickness setting device 48 for setting the plate thickness IG, and the output signals N, D of the counter 26, the reel diameter setting device 46, and the plate J/Z setting device 48. , a remaining length calculator 50 that calculates the remaining length LR of the rolled material on the reel 19 from IG, and output signals D, IG, of the reel diameter setter 46, plate thickness setter 48, and registered position memory 36, The defective point plate length calculator 52 converts the position (number of turns) of the defective point registered from n to the plate length C from the coil unwinding side end, and the remaining length calculator 50 From the remaining length LR of the rolled material 16, the plate length (from the coil unwinding side end of the defective point obtained by the defective point plate length calculator 52) is subtracted, and the difference LR-
A speed measurement B that detects the rotation speed of the work roll 22 of the rolling mill 18 using a difference calculator 54 that calculates °C and a pulse oscillator 55 and measures the rolling speed of the rolled material 16 from this detected value.
56, this speed measuring device 56, and the registered speed memory 44
, a deceleration-required plate length calculator 60 that calculates the plate length LS of the rolled material 16 necessary to decelerate the material to be rolled 16 from each output signal 0, vl, and a of the deceleration rate memory 58 to the registered speed; A comparator 62 that compares the output signals LR-J2 and LS from the calculators 54 and 60 and outputs a deceleration command for the mill motor 23 to a mill motor drive means 63, which will be described later, when these signals match, and this comparator. Mill motor 1 financial means 63 that drives the mill motor 23 based on a deceleration command from 62
It is composed of. The speed control means 12 also includes a comparator 68 for determining the end of deceleration. After the start of deceleration, the comparator 68 compares the rolling speed 0 from the speed measuring device 56 and the registered speed V1 of the registered speed memory 44 at regular intervals, and when the comparison results in that the two match, The pulse signal causes the mill motor 23 to be driven through the mill motor drive means 63.
At t7 and 7, the holding command is outputted at t7. The reference numeral 64 in the figure indicates a gate that receives the rolling speed immediately before the start of deceleration from the speed measuring device 56 in conjunction with the deceleration command using the pulse signal of the comparator 62. A speed memory is shown that stores the rolling speed taken in from the gate 64. The remaining length calculator 50 calculates the coil remaining length LR based on the relationship of the following equation. LR=π・N (D+ <IG-N)/σ)...(1
) Here, D is the reel diameter, π is the circumferential skewer, IG is the set plate thickness, N is the number of turns, and σ is the occupancy rate of the slip sheet. In addition, the defective point plate length calculator 52 calculates the plate length (from the coil unwinding side end to the defective point) based on the relationship of the following equation. Jl=yr-n (D+ (IG −n ＞/a) −(
2) Here, n indicates the number of turns of the registered defective point. The plate length required for deceleration calculation unit 6o calculates the plate length LS required for deceleration based on the relationship of the following equation. LS=β i (VO2-Vl2)/2a)-
(3) Here, β is the entrance plate speed correction coefficient, ■o is the current rolling speed output from the speed measuring device 56, Vl is the registered speed, and a is the deceleration rate. The correction coefficient β is calculated from the following relationship. β= (1+a) (ho/hi)
-<4) Here, α is the advance rate, ho is the exit side plate thickness,
hi indicates the entrance side plate thickness. As shown in FIG. 4, the speed correction means 3 includes a timer 70 which is started by a pulse signal output from the comparator 62 which starts the deceleration command output, and a timer 70 which measures the speed at regular intervals. A gate 72 outputs the current rolling speed from the device 56 to a comparator 74 (described later), and the deceleration rate memory 58 is calculated from the output signals a, VM, and t of the deceleration rate memory 58, speed memory 66, and multi-timer 70. The predicted rolling speed calculation 376 calculates the predicted rolling speed v' based on the deceleration rate a, and the predicted rolling speed V' from this calculator 76 is compared with the actual measured speed from the speed detector 56 to determine the rolling speed of the mill motor 1. and a comparator 74 for controlling the means 63. The predicted rolling speed calculation unit 76 calculates the predicted rolling speed V' based on the relationship of the following equation. V'=VM-a-t=・(4) Here, VM is the speed before the start of deceleration from the speed memory 66,
a represents the deceleration rate, and t represents the time from the start of deceleration. Next, the operation of this embodiment will be explained. First, a method for registering defective points in the n-th pass will be explained with reference to FIG. Now, the material to be rolled 16 is rolled by rolling 8118 on the reel 1 on the right side of the figure.
It is rolled in the winding direction. At this time, the counter 26 adds up the pulses from the pulse oscillator 24 linked to the rotation of one reel to count the number of rotations of one reel. Depending on the direction of rotation of the reel 19, the counter 26 adds up when the reel 19 rotates in the winding direction, and subtracts when the reel 19 rotates in the unwinding direction. . Further, this counter 26 is cleared to zero at the start of winding by the output of the winding start determination circuit 28. This winding start determination is performed based on sequence signals such as rolling direction switching. The operator presses the defect registration button 30 when the defective point of the rolled material 16 comes to a predetermined position near the rolling mill 18.
This opens the gate 32 and inputs the output value of the pulse counter 26 into the turn number corrector 34.The turn number corrector 34 calculates the number of turns when the defective point is at the position of the work roll 22. Convert. The output value from this turn number corrector 34 is stored in the registered position memory 36. As a result, the position information of the defective point is registered as the number of turns n. Next, by setting an arbitrary speed using the speed setting device 38 and pressing the deceleration speed Ji' registration button 40, the gate 42
, and the speed set by the speed setter 38 is stored in the registered speed memory 44. By repeating the above operations, the position information of a plurality of defective points is registered in the registered position memory 36, and the corresponding deceleration speed is registered in the registered speed memory 44. Next, with reference to FIG. 3, the material to be rolled
A method of starting and ending deceleration when rolling a material 6 in the unwinding direction from the reel 19 on the right side in the figure in the rolling mill 18 will be explained. First, a pulse oscillator 24 linked to the rotation speed of the reel 19
The counter 26 subtracts the pulse from the number of winding turns of the previous pass to count the number of remaining turns of one reel at the time of rewinding. Based on the remaining number of turns N obtained from the counter 26 and the set values IG and D from the plate thickness setter 48 and reel diameter setter 46, the remaining length calculator 50 calculates, based on the above equation (1),
The remaining length LR of the rolled material 16 on the reel 19 is calculated. In addition, the reel diameter setting device 4 is determined by the defective point plate length calculator 52.
6. From each output signal of the number of turns of the plate thickness setter 48 and the registered position memory 36, IG, n, the position of the registered defective point is determined on the coil unwinding side based on the above equation (2). Convert to the length of the board from the end. Further, a difference calculator 54 subtracts the plate length from the tip of the coil at the defective part obtained by the calculator 52 from the remaining length LR of the rolled material obtained from the remaining length calculator 50 to obtain a difference LR. − Find n. Further, the speed measuring device 56, the registered speed memory 44, and the deceleration rate memory 58 are calculated by the deceleration required plate length calculator 60.
The length LS of the rolled material required to reduce the speed to the registered speed from the output signal 0, vl, a is determined based on the above equation (3). Next, the output signal LR-(,LS
are compared by a comparator 62, and when the two match, a pulse signal from the comparator 62 outputs a deceleration command to the mill motor 23 via the mill motor drive means 63. Further, in conjunction with this deceleration command, the gate 64 is opened, the rolling speed of the material to be rolled 16 immediately before the start of deceleration is taken in from the speed measuring device 56, and this rolling speed is assigned to the speed memory 66. After the above operations, deceleration is advanced by deceleration curve correction, which will be described later. The end of deceleration is determined by periodically checking the speed measuring device 5 after starting the yA series.
The comparator 68 compares the output signal vO of 6 with the contents of the speed memory 44 (registered speed Vl) this evening, and when the two match, the mill motor is Output a hold command to 23,
End deceleration. Next, the next control data is read from the registered position memory 36 and the registered speed memory 44 according to the pulse signal of the comparator 68, and deceleration control is performed in the same manner as described above. Next, with reference to FIG. 4, a description will be given of correction of the deceleration curve after the deceleration command is output. First, the timer 70 is activated by a pulse signal output from the comparator 62 that activates the deceleration command output. This timer 70 opens the gate 72 at fixed time intervals after activation,
The current rolling speed from the speed detector 56 is output to the comparator 74. Further, the predicted rolling speed calculator 76 calculates the deceleration rate memory 5.
8. Speed memory 66 and the output signal a of the timer 70
, VM, t is calculated based on the above-mentioned formula (4>). Next, a comparator 74 calculates the predicted rolling speed v' calculated by the calculator 76 and the predicted rolling speed V' obtained by the gate 72. The current rolling speed is compared with the current rolling speed. As a result of this comparison, when the current rolling speed becomes lower than the predicted rolling speed V' by a certain value or more, the comparator 74 outputs a pulse signal to the mill motor drive means 63. A holding command is outputted to the mill motor 23 via the mill motor driving means 63 in response to the pulse signal.This stops the deceleration and maintains the rolling speed.After outputting this holding command, the deceleration as explained in FIG. When the output timing of the command is reached, the deceleration command is output again. By repeating deceleration and holding as described above, the deceleration pattern shown by the broken line A in the figure is created as shown in Figure 5, and the deceleration is The curve is almost the same as the iI! speed curve shown by the solid line B in the figure used to derive the distance. Therefore, by dividing the correction period of the deceleration curve into J divisions, the error in the deceleration completion point is reduced. In the above description, the registration of defective points of the rolled material 16 and the deceleration method are explained only in one direction, but the registration of defective points and the deceleration method in the other direction are not limited to this. The deceleration method can also be implemented in the same way.
Also, the registered position memory 36 and the registered speed memory 44 are installed in 2M1, and depending on the rolling direction, these inputs and outputs are transferred to the registration side shown in the above-mentioned Fig. 2 or to the above-mentioned Fig. 3. By switching to the control side shown, the above operation can be continuously repeated for subsequent buses as well. Furthermore, by setting the contents of the registered position memory 36 to zero, this device can also perform a tail end stop. Effects of the Invention As described above, according to the present invention, deceleration can be accurately terminated with respect to the position of a defective portion of a rolled material registered in advance. In addition, the speed after deceleration can be set in advance, and excessive '/JA speed and insufficient deceleration can be eliminated, and appropriate deceleration can be performed to perform efficient rolling. Has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the gist of the automatic reduction device for a rolling mill according to the present invention, and FIG. 2 includes a partial side view for explaining the defect point registration method in the same embodiment. A block diagram, FIG. 3 is a block diagram including a partial side view for explaining the start and end of deceleration in the same embodiment, and FIG. 4 is a block diagram for explaining deceleration curve correction in the same embodiment. FIG. 5 is a block diagram showing an example of a deceleration pattern in the same embodiment. DESCRIPTION OF SYMBOLS 10... Position storage means, 11... Target speed storage means, 12... Speed control means, 13... Speed correction means, 16... Rolled material, 18... Rolling mill, 1
9.20...Reel, 23...Mill motor, 36...Registered position memory, 14...Registered speed memory, 63...Mill motor drive means.

Claims (1)

[Claims] (1) In an automatic reduction gear of a rolling mill that decelerates and controls the rolling speed of a reversible rolling mill based on information on the position of the rolled material, a position storage means that stores information on the position of the rolled material whose rolling speed should be reduced. and target speed storage means for storing the target speed after deceleration; and in response to coincidence between the position information from the position storage means and the position of the rolled material to be decelerated, the rolling speed is changed to the target speed. A speed control means for decelerating so as to reach the target speed of the storage means, and a speed correction means for correcting the deceleration rate of the actual rolling speed so that it becomes the target deceleration rate when decelerating by the speed control means. An automatic reduction gear for rolling mills featuring: