KR970000374B1 - Wire rod dividing method in wire rod mill - Google Patents

Abstract

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Description

[Name of invention]

Wire Rod Splitting Method in Wire Rolling Equipment

[Brief Description of Drawings]

1 is a flow chart for explaining the procedure of the wire splitting method in the preferred wire rolling equipment according to the present invention.

2 is a diagram for explaining a concrete wire splitting state and a rolling speed control system in this wire splitting method.

3 is a diagram for explaining a modification of the rolling speed control in this wire rod dividing method.

4 is a diagram for explaining a control means for pitch time or pitch distance between a tail end of a preceding wire and a front end of a subsequent wire.

5 is a block diagram showing a looper, a kicker, and a motion control system between the rolling mills.

6 is a view for explaining the operation control system of the kicker.

7 is a block diagram showing a speed control system for each rolling stand.

8 is a diagram for explaining a general wire rod rolling equipment and a conventional wire rod dividing means.

Detailed description of the invention

[Technical Field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for splitting wire rods in wire rod rolling equipment used when wire rods (bare steel) produced in wire rod rolling equipment are divided on a rolling line to produce a plurality of wire rod coils from one steel strip (billet).

[Background]

In recent years, from the standpoint of focusing on the productivity of wire rod rolling equipment, the weight (single weight) of the material to be rolled is suddenly increased in size (for example, 700kg → 1000kg → 2000kg), and it is small by the user. Heavy wire coils may be required. In order to manufacture the wire rod coil in the small stage, 1) rolling is performed from the billet in the small stage required by the user, or 2) the wire rod is divided into a wire rod in the small stage required during the rolling process.

In the former (1), in order to use the billet in the small stage, productivity and yield due to the increase of handling operation according to the increase of the number of billets, the cutting off of the defective part at the rear end, and the loss of energy in the heating furnace, etc. In order to cause the deterioration of, conventionally, the equipment as shown in FIG. 8 that can realize the latter means is used.

In FIG. 8, 1 is a heating furnace for heating a billet, 2 is a rough rolling train for rolling the heated billet, 3 is a rolled wire rod, and 4 is a cut of the wire 3 in the rough rolling train 2. First flying shears (driving shears), 5, 6 are first and second intermediate rolling trains, and 7 is a first capable of cutting wire 3 from the second intermediate rolling mill 6, respectively. 2, 8 is the finishing line of the winding machine line 9 or the finishing rolling line 10, 14 is the looping layer 15 and the conveyor ( It is a coil collector part which receives and winds the wire rod 3 from the finishing rolling sequence 13 through 16).

The case of manufacturing two bundles of 1-ton wire rod coils from 2 tons billets by the installation of the structure mentioned above is demonstrated, for example. In the case of using the winding machine line 9, the billet heated by the heating furnace 1 is rolled by the rolling column 2, 5, 6, and the obtained wire rod 3 is wound on the winding machine line 9 by the V selector 8. ), While measuring the length of the wire rod, the winding of the preceding material of the wire rod 3 is first performed in the first winding machine 11. When the intermediate point of the winding wire based on the result of the length measurement reaches the second flying shear 7, the flying shear 7 cuts and splits the wire 3 and winds up the first winding machine. The second winding machine 12 is rolled at (11), and the subsequent material of the wire rod 3 is wound by the second winding machine 12. As a result, one tonne of wire rod coil is produced from two tonnes of billets. At this time, the maximum linear velocity of the wire rod 3 in rolling differs depending on the equipment specification, but is generally about 20 m / sec because the wire diameter is relatively large.

In addition, in the case of using a finishing rolling line (generally a type directly connected with a block mill and a direct heat treatment apparatus) 10 in order to manufacture a coil having a relatively small wire diameter, the rolling columns (2, 5, 6) are used as described above. After the wire rod 3 rolled by the wire is transferred from the V selector 8 to the finish rolling sequence 13 and finish rolling is performed, the coil collector portion 14 is passed through the roof layer 15 and the conveyor 16. Is transferred to. In the coil collector unit 14, the wire rod 3 for two tons is received in a coil state, and the wire rod coil is cut and divided by one ton in the coil collector unit 14. At this time, the maximum speed of the wire rod 3 in rolling is approximately 100 m / sec.

However, in order to handle the divided wire rod coil in the coil collector portion 14 installed at the final position of the equipment, it is necessary to reliably separate the coils. Therefore, a special device as the coil collector portion 14, namely a coil cutting function, is required. Since the coil collector part 14 provided with this is required, not only installation cost becomes expensive, but also complexity arises in operation of such installation. Also, in the case of using the finishing rolling line 10, it is possible to roll using the billet in the small step required by the user, but in this case, the increase or decrease of the handing operation due to the increase in the number of billets as described above. Cut off of the defective part of a stage and the fall of productivity and yield by energy loss etc. in a heating furnace cannot be avoided.

Therefore, the present invention has been made to solve the above problems, so that the material to be rolled in the production of the wire rod by using the wire rolling equipment can be cut and divided to any weight without impairing the productivity of the equipment. It is an object of the present invention to provide a wire splitting method in wire rod rolling equipment.

[Initiation of invention]

The present invention adjusts the rolling speed by the upstream rolling mill or the downstream rolling mill at the cutting position of the wire rod after cutting by the flying shear of the wire rod, so as to be upstream from the preceding wire rod downstream of the cutting position and the cutting position. A relative speed difference is given to the subsequent wire on the side, so that there is an appropriate gap between the preceding wire and the subsequent wire. According to this fact, even when the finishing rolling line is used on the downstream side, the wire rod coils can be reliably separated from each other, so that the divided wire coil can be easily handled without having a special function in the coil collector portion. Moreover, this invention is provided with the looper for forming a suitable loop in mutual wire of the rolling mill of a wire rod rolling installation, and the kicker which displaces a wire rod toward the looper, and the front end of a wire rod is predetermined position upstream rather than a kicker. And the rolling speed of the wire rod is integrated until the kicker is operated, and the integral value is stored as the kicker operation timing reference value, and the subsequent wire rod after cutting by the flying shear reaches the predetermined position. By integrating the rolling speed of the wire rod, when the integral value for the subsequent wire rod is the kicker operation timing reference value, the kicker is operated to ouster the subsequent wire rod to the looper.

At this time, the integral value corresponds to the traveling distance of the preceding wire rod or the subsequent wire rod at the predetermined position. That is, the kicker is operated by detecting the timing at which the subsequent wire has advanced to the predetermined position with respect to the kicker. Therefore, even if any speed difference is given between the preceding wire and the subsequent wire, the kicker is always operated at the optimum timing. Can be.

In addition, the present invention includes a looper for forming a suitable loop in the wire of the rolling mill of the wire rod rolling equipment, and a loop amount control system for outputting the speed correction value of the rolling mill to keep the loop amount of the wire in the looper constant. , The speed correction value from the loop amount control system is calculated independently of the split speed command value at the time of giving a relative speed difference to the preceding wire and the subsequent wire, and is output to the rolling mill. Due to this fact, the multiplication of the predetermined deceleration rate is not performed for the speed correction value from the loop amount control system at the time of calculating the split speed command value, and the loop amount can be corrected in a short time and the loop amount control can be stably performed. have.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION In order to demonstrate this invention in detail, the best form (henceforth an Example) for implementing this invention is demonstrated according to attached drawing.

The overall basic configuration of the wire rolling equipment to which the method of the embodiment of the present invention is applied is almost the same as the equipment shown in FIG. 8, but in this embodiment, the detailed parts thereof, that is, the looper kicker between the rolling stand (rolling machine) and The operation control system is configured as shown in FIG. 5, while the speed control system of each rolling stand is configured as shown in FIG. In addition, in the present embodiment, the finish rolling line 10 side is selected in particular, and as shown in FIG. 2, it is arranged between the rough rolling train 2 and the first intermediate rolling train 5. When the wire rod 3 is cut by the first flying shear 4, the method of the present invention is applied. In addition, as shown in FIG. 2, in this embodiment, the rough rolling train 2 is comprised by the 1st rolling stand (not shown)-the 8th rolling stand ST8, and the cutting position of the wire rod 3 is shown. The first intermediate rolling train 5 has at least a ninth rolling stand ST9 to an eleventh rolling stand ST11, while being a rolling train on the upstream side with respect to the arrangement position of the flying shear 4; And the rolling sequence on the downstream side with respect to the cutting position of the wire rod 3.

Therefore, the basic operation of the wire dividing method in the present embodiment will be described with reference to FIG.

First, set the rolling speed, the presence or absence of splitting, and the pitch time (distance) (steps S1 to S3), and the pitch-to-pitch distance C (coil to coil; required) between the preceding wire 3a and the subsequent wire 3b. Corresponding to the space | interval d), the acceleration-deceleration rates (alpha), (beta), and the deceleration ratio k of the upstream rolling sequence, ie, rough rolling sequence 2, are set (step S4). The acceleration / deceleration rates α and β are determined by the capacity of the drive motor of each rolling mill (rolling stand), and the subsequent wire 3b of the wire rod 3 cut by the flying shear 4 is followed by the next rolling stand ST9. Acceleration / deceleration ratios (α, β) and reduction ratios (k) are set so that the rolling speed is synchronized until the transfer (insertion) is carried out. Here, the speed of the subsequent wire 3b is faster than the rolling speed of the next rolling stand ST9. At this time, a compression action occurs on the subsequent wire 3b, while when the speed of the subsequent wire 3b is lower than the rolling speed of the next rolling stand ST9, a sudden tensile action occurs on the subsequent wire 3b. In order to synchronize the speed of the tip of 3b) with the speed of the next rolling stand ST9, the acceleration / deceleration rates α and β and the reduction ratio k are set. In addition, in this step S4, the setting method of the acceleration / deceleration rates (alpha), (beta) and the deceleration ratio k is mentioned later for an example.

Subsequently, the dividing number of one billet is set (step S5), the length of the rolled wire rod 3 is measured (step S6), and when the length measurement result is the length according to the set dividing number (step S7), The first flying shear 4 is activated (step S8). In response to this, when the cutting motion is detected by the flying shear 4 (step S9), the rough rolling train 2 is decelerated (step S10).

That is, as shown in FIG. 2, after cutting by the flying shear 4 of the wire rod 3, the rolling speed of the rough rolling train 2 is set in step S4 with respect to the cutting position of the wire rod 3. FIG. By decelerating at the deceleration rate β and the deceleration rate k and maintaining the rolling speed of the first intermediate rolling train 5 as it is, the lead wire 3a downstream of the cutting position and the cutting position The upstream subsequent wire 3b is given a relative speed difference ΔV as shown in FIG. 2, so that an appropriate distance d between the preceding wire 3a and the subsequent wire 3b (e.g., About 7m).

During the deceleration of the rough rolling sequence 2, the position of the leading end of the subsequent wire 3b is detected by constant tracking (step S11), and as described above, a suitable interval between the preceding wire 3a and the subsequent wire 3b. It is determined whether (d) has risen (step S12). When only the proper interval d is lifted, the rolling speed is increased when the tip of the subsequent wire 3b reaches the next rolling stand (the first rolling stand of the intermediate rolling train 5) ST9. As synchronized with the rolling speed of the rolling stand ST9, the rolling speed of the rough rolling train 2 is accelerated to the acceleration rate α set in step S4 (step S13).

When it is judged that cutting by the number of divisions set for one billet has been performed (step S14), the wire rod dividing method by the above steps S6 to S13 is terminated.

As described above, according to the wire division method in the wire rod rolling equipment of the present embodiment, when the wire rod 3 is cut by the flying shear 4, the preceding wire 3a on the downstream side of the cutting position and the subsequent wire rod on the upstream side ( By allowing a proper distance d between the 3b), even when the finishing rolling line (see numeral 10 in Fig. 8) is used on the downstream side, the wire collector coils are reliably separated from each other. The divided wire rod coil can be easily handled without imparting a special function to the reference numeral 14 of FIG. 8. Therefore, by using the finishing rolling line, it is possible to cut and divide the billet at any weight without damaging the productivity of the equipment and at a low equipment cost.

In the present invention, in the wire rolling equipment, the reversing control is adopted for the rolling motor, but the retardation control is performed by setting the deceleration rate so that the reduction torque of the crude rolling train 2 is less than or equal to the rolling torque. It is also possible to easily perform full-speed control at low cost without using the

In addition, in the above embodiment, when the wire rod 3 is transmitted by the first flying shear 4, a method of accelerating and decelerating the upstream rolling train (rough rolling train 2) is applied. (In the case of accelerating and decelerating the first intermediate rolling train 5, or the first intermediate rolling train 5 and the second intermediate rolling train 6, the method of the present invention can be applied in the same manner. Since the control may become unstable in order to simultaneously accelerate and decelerate the rolling stand on the downstream side including the loop control, the application of the method maintains the speed of the first intermediate rolling train 5 and the rough rolling train 2 In the case where the wire rod 3 is cut by the second flying shear 7, the method of the present invention can be applied in almost the same way. Upstream, including loop control Since the control may become unstable in order to accelerate and decelerate the rod simultaneously, if the application position of the method is selected from the first flying shear 4 and the second flying shear 7, the first flying shear 4 is used. This is preferred.

In addition, in the above embodiment, the case where the speed adjustment of each rolling sequence 2 and 5 is performed by using the position of the flying shear 4 as a reference position has been described. However, the position of any rolling stand (rolling mill) constituting each rolling sequence is described. The speed may be adjusted on the basis of. Since the position of the flying shears 4 and 7 is referred to as the reference position or the position of any rolling stand as the reference position is influenced by the equipment specifications. In the application of the method of the present invention, if the distance between the rolling sequences before and after is sufficient, the positions of the flying shears 4 and 7 may be used as reference positions.

In addition, in the above embodiment, the case in which the gap between the preceding wire 3a and the subsequent wire 3b is spaced apart by decelerating and accelerating the upstream rolling train (crude rolling train 2) is described. Even if the first intermediate rolling train 5 is accelerated and decelerated, or as shown in FIG. 3, the deceleration and acceleration of the upstream rolling train (rolling stand ST8) and the downstream rolling train (rolling stand ST9, Even if the acceleration / deceleration of ST10) are combined, the same effects as in the above embodiment can be obtained.

4 shows the pattern of the exit speed N ₈ of the rolling stand ST8 in particular with respect to the control means of the interval d between the preceding wire 3a and the subsequent wire 3b. It demonstrates and demonstrates. Also, in _Fig. 4, N _8TOP is the maximum rotational speed of the rolling stand ST8, kN ₈ is the speed after deceleration, td is the deceleration time from speed N ₈ to kN ₈ , tc is the constant running time at speed N ₈ , ta Is the acceleration time from the speed kN ₈ to N ₈ , and Ta is the acceleration timing from the start of deceleration to the start of acceleration.

The pitch time Td of the wire rod between the preceding wire rod 3a and the subsequent wire rod 3b is expressed by the following equation (1).

Td = d / N ₈ = (L1-L2) / N ₈ . … … … … … … … … … … … … … … … … … … … … (One)

However, L1 is the moving distance of the preceding wire 3a, L2 is the moving distance of the tip of the subsequent wire 3b, and is represented by the following equations (2, 3), respectively.

L 1 = N ₈ (td + tc + ta)... … … … … … … … … … … … … … … … … … … … … … … (2)

L 2 = (N ₈ + kN ₈ ) (td + ta) / 2 + kN ₈ . … … … … … … … … … … … … … … … (3)

Therefore, considering the acceleration timing Ta and Ta = td = tc and substituting the equations (2) and (3) into (1), the following equation (4) is obtained.

Ta = Td / (1-k) + (td-ta) / 2... … … … … … … … … … … … … … … … … … … … (4)

That is, when k, α, β determined by testing by rolling schedule are tabulated, and the operator sets the pitch time Td between wire rods, the acceleration timing Ta is calculated by the above equation (4) to obtain the inter-wire rods. It is possible to control the pitch time Td, that is, the distance d between the wire rods.

Next, the example (step S4 of FIG. 1) which calculates these acceleration-deceleration rates (alpha), (beta) and the reduction ratio k by calculation is demonstrated.

In the rough rolling train 2 of the wire rod rolling equipment utilizing the control of the distance between the wires d, the irreversible thyristor is left as it is in order to reduce the cost of the retrofit of the equipment (in the present invention in all sizes). In order to apply the division control by means of the embodiment, only the rolling stands ST9 and ST10 are retrofitted to the reversible thyristor; the reversible thyristor can be rapidly decelerated, and it cannot decelerate to a deceleration rate that requires a deceleration torque above the rolling torque. Therefore, the load torque of each rolling stand ST1 to ST8 in each rolling stand ST1 to ST8 in the rough rolling train 2 is measured, and the possible reduction rate of each stand is calculated, and the minimum reduction rate is among them. Is determined as the deceleration rate of the whole rolling stand. In addition, the load torques of the rough rolling train 2 and the rolling stands ST9 and ST10 are measured to calculate the possible acceleration rates of the respective rolling stands (to prevent the rolling torque and the acceleration torque from exceeding a predetermined torque). Among them, the minimum acceleration rate is determined as the acceleration rate of the whole rolling stand. If the deceleration rate and acceleration rate determined in this way are β and α, respectively, equation (3) is modified as follows.

L2 = (N ₈ + kN ₈ ) [(N ₈ -kN ₈ ) / β + (N ₈ -kN ₈ ) / α] + kN ₈ · tc

= (N ₈ + kN ₈ ) [(N ₈ -kN ₈ ) / β + (N ₈ -kN ₈ ) / α]

+ kN8 [Td / (1-k)-{(N ₈ -kN ₈ ) / β + (N ₈ -kN ₈ ) / α} / 2]

= N ₈ ² (1-k) (1 / β + 1 / α) / 2 + N ₈ Td · k / (1-k). … … … … … … … … … (5)

As shown in FIG. 4, since L2 is the travel distance of the front end of the subsequent wire 3b, that is, the exit length of the rolling stand ST8 immediately preceding the rolling stand ST11 in the flying shear 4, L2, β Since, α and N ₈ are already known, the predetermined reduction ratio k can be obtained from the above expression (5).

However, in the wire division method shown in FIGS. 1 to 4, a speed difference ΔV must be provided between the preceding wire 3a and the subsequent wire 3b, and a rapid deceleration command is output to the subsequent wire 3b. And rolling is performed by the reduced rolling speed. For this reason, if the looper kickers described later in FIG. 5 are provided between the rolling stands, the kickers are operated at the same timing as the preceding wires, and the wire rods are evicted. It may cause a misunderstanding. That is, the operation timing of the kicker is considerably different from that of the preceding wire 3a and the subsequent wire 3b, and the timing cannot be adjusted well in timing control. Even if the kick timing is too early, rolling of the wire rod 3 does not go well and leads to a miss roll.

In this embodiment, as shown in FIG. 5, an operation control system for the kicker for the subsequent wire 3b is provided.

In Fig. 5, 17 is a looper, which serves to form a suitable loop on the wire rods 3 of the rolling stands ST _i and ST _{i + 1} , and 18 to this looper 17. A kicker for kicking the wire rod 3 toward the front side, 19 is a HMD (Hot Metal Detector) disposed at a predetermined position upstream of the kicker 18 and detecting the arrival of the wire rod 3, 20 is an air cylinder (not shown). A kicker control device for controlling the ejection operation of the kicker 18 through a), 21 is a pulse generator for detecting the rotational speed (N _i ) (rolling speed) of the rolling stand (ST _i ), 22a is a timing setting for the preceding wire rod It is a timing which operates based on time T set by the operator in the machine 22c, and this timing 22a is the position of the HMD 19 in which the front-end | tip of the preceding wire 3a is rolled at the normal rolling speed. To reach the start of the ejection operation by the kicker 18 (see Fig. 6; command after detection of the HMD 19). Set by the setter 22c at the time until the eviction timing, which is operated upon receiving the on signal from the HMD 19 to output the eviction instruction of the preceding wire 3a by the kicker 18. will be. 22b is the time T set by the setter 22c and the delay time? T 'set by the operator from the delayed time setter 22d (see FIG. 6; Operation is performed when the ON signal from the HMD 19 is received at a timing at which the time T = Δt 'obtained by adding the operation delay time of the kicker control device 20) is added by the adder 22d.

23 is the pulse generator 21 while the detection signal of the tip of the wire rod 3 (leading wire rod 3a) is received by the HMD 19 and the start time T + Δt 'by the timing 22b elapses. Is an integrator that integrates the rotational speed N _i from the above, and the timing 22 and the integrator 23 of the wire rod 3 (leading wire rod 3a) rolled at a normal rolling speed at the start of rolling. It only works for the tip. 24 is a hold circuit 24 which stores the integral value by the integrator 23 as the kicker operation timing reference value D ₀ .

In addition, 25 is an integral of the rotation speed N _i from the pulse generator 21 when the operation completion signal from the flying shear 4 and the detection signal by the HMD 19 at the tip of the subsequent wire 3b after the cutting are received. The starting integrator, 26, calculates and compensates the operation delay from the command extraction timing of 18 to the actual extraction timing based on the rotation speed N _i , the acceleration rate α, and the kicker operation delay time Δt. 27 is an adder for adding an integral value from the integrator 25 and an operation delay from the kicker operation delay compensation calculation unit 26, and 28 is a reference value stored in the hold circuit 24 (D _0). Is compared with the value from the adder 27, and outputs an operation command to the kicker control device 20 when the value from the adder 27 becomes the reference value D ₀ .

With the operation control system having such a configuration, when the tip of the preceding wire 3a reaches the HMD 19 at a predetermined position upstream from the kicker 18, it receives heat from the wire 3a and receives the HMD ( 19) is detected. The detection signal from the HMD 19 is output to the timing 22b and the integrator 23, until the kicker 18 is actually operated at the leading end indication point of the preceding substrate 3a (time T = Δt ' ), The rotation speed N _i from the pulse generator 21 corresponding to the rolling speed of the preceding wire 3a is integrated in the integrator 23, and the integrated value is a hold circuit (K0) as the kicker operation timing reference value D ₀ . Is remembered in 24). The integral time set at the timing 22b is determined by adding the time T set by the operator in advance and the operation delay time Δt '(schedule) of the air cylinder or the like which controls the operation of the kicker 18. It is.

After the end of the integration of the leading wire 3a to the tip, the wire 3 is divided into the leading wire 3a and the subsequent wire 3b in the cutting by the flying shear 4, and the flying shear 4 at this time When the operation completion signal of and the detection signal from the HMD 19 outputted by detecting the arrival of the position of the HMD 19 at the tip of the subsequent wire rod 3b are obtained, the subsequent wire rod from the tip detection time of the subsequent wire rod 3b is obtained. The rotation speed N _i from the pulse generator 21 corresponding to the rolling speed of (3b) is integrated in the integrator 25. The integral value (see the sixth time) of the operation delay integral from the kicker operation delay compensation calculation unit 26 is added to the integral value from the integrator 25. As a result, the operation delay of the air cylinder for driving the kicker 18 can be absorbed.

The integral value (calculation result from the adder 27) for the subsequent wire 3b and the kicker operation timing reference value D ₀ from the hold circuit 24 are compared by the comparing section 28, and these are compared. At the same time, an operation command is output from the comparator 28 to the kicker control device 20, and the kicker 18 evicts the subsequent wire 3b to the looper 17 side. 17, a suitable loop can be formed in the subsequent wire 3b.

At this time, each value in the integrator 23 and the adder 27 corresponds to the travel distance of the wire rods 3a and 3b from the position of the HMD 19. That is, the operation of the kicker 18 is performed by detecting the timing at which the subsequent wire 3b has advanced to the predetermined position with respect to the kicker 18. Therefore, the kicker 18 can be operated between the preceding wire 3a and the subsequent wire 3b. Even if one speed difference DELTA V is provided, it is possible to always operate the kicker 18 at the optimum timing. Therefore, according to the wire division method of the present embodiment having the operation control system as shown in FIG. 5, the operator sets the time T, Δt 'at the timings 22a and 22b only for the preceding wire 3a. It is good to carry out only, and setting of the subsequent wire 3b is unnecessary, so that stable wire rolling and splitting operation can be established without causing a mistake by simple operation.

In addition, in this embodiment, the positions of the HMDs (thermal steel detectors) 19 are set to each other between the rolling stands ST _i and ST _{i + 1.} However, the rolling stand ST _{i- which} does not show the HMD 19 is shown. _When set between ₁ and ST _i , the speed of the rolling stand ST _i-1 is integrated.

On the other hand, in order to realize stable rolling, as shown in FIGS. 5 and 7, in the roofer 17 provided between the rolling stands, the roof height (loop amount) of the wire rods 3 between the rolling stands is kept constant. It is necessary to do In order to make the loop height constant, a loop amount control system is usually provided which corrects the speed of each rolling stand in accordance with the roof height.

In the above wire splitting method, each rolling stand is decelerated by applying a speed difference (ΔV) to the preceding wire 3a and the subsequent wire 3b, but at this time, the speed command value to each rolling stand and the loop It is common to output the speed correction value from both control systems and the sum multiplied by the deceleration rate in turn to each rolling stand as a split speed command value for giving a speed difference (ΔV). That is, since the speed reduction value is also multiplied by the speed correction value for maintaining the amount of loops, a shortage is generated in the amount of loop correction between the old rolling stands, which requires time for loop correction and stable control cannot be performed. It will interfere with maintenance.

Thus, in this embodiment, the speed control system of each rolling stand as shown in FIG.

In Fig. 7, 29 is an MRH (Master RHeostat) for setting the speed of the whole rolling stand according to the steel grade, size, etc., and this MRH 29 is used when the speed of all the rolling stands are changed at the same time, and the signal of the percentage (%) is shown. Will be output as 30 is SSRH (Stand Speed RHeostat) which sets the speed in each rolling stand with respect to MRH 29 and outputs it as a signal of ratio (%), so that manual intervention etc. may be made in this part of SSRH 30. It is.

31 is a multiplier that multiplies the signal from the MHR 29 and the signal from the SSRH 30, and 33 receives the multiplication result from the multiplier 31 as the speed command value of the rolling stand, and accelerates to this speed command value. Is a gradient function generator that sets the deceleration pattern from the same speed command value and outputs the speed command value. 34 is a loop sequential signal from the downstream side (a ratio signal given when the speed correction is performed to maintain the loop amount on the downstream side). ) Is a multiplier that multiplies the speed command value from the gradient function generator 33, 35 is an adder that adds the speed command value from the gradient function generator 33 and the multiplication result from the multiplier 34, 36 is a block currently being rolled. The wire splitting speed commander 37 outputs the deceleration command (ratio) based on a predetermined pattern to the subsequent wire 3b after the division when the wire splitting command signal is input to the wire rod splitting command. It is a multiplier which multiplies the deceleration command from the split speed commander 36 with the output from the adder 35 and outputs it as the split speed command value.

In addition, 38 is a loop height detector which detects the loop height (loop amount) of the wire rod 3 in the looper 17, 39 receives the detection signal from this loop height detector 38, and makes a loop height constant. The loop amount control system (LOOP) which calculates and outputs the speed correction value required for holding, 40 calculates the ratio of the speed correction value by dividing the speed compensation value from the loop amount control system 39 by the current speed command value from the multiplier 37. The divider, 41 is an adder which outputs the speed correction value from the loop amount control system 39 and the division speed command value from the multiplier 37 and outputs it as a formal speed command value, and 42 is the ratio of the speed correction value from the divider 40 and An adder which adds a loop sequential signal from the downstream side and outputs it as a loop sequential signal to the upstream side, and 43 denotes a speed of the rolling stand according to the speed command value from the adder 41; It is a thyristor which controls the speed of the moving motor 44. FIG.

The speed correction value output from the loop amount control system 39 is calculated independently of the split speed command value so that the speed control system configured as described above keeps the loop height of the wire rod 3 in the looper 17 constant. Then, the divided speed command value output from the multiplier 37 and the adder 41 are added and output to the thyristor 43.

Therefore, the deceleration rate from the wire division speed command unit 36 is not multiplied by the speed correction value from the loop amount control system 39 at the time of calculation of the split speed command value, and the speed correction value is not affected by the wire division speed command. In the wire splitting method of the present embodiment, even when the rolling stand is decelerated to give a speed difference ΔV to the preceding wire 3a and the subsequent wire 3b, the loop height can be corrected for a short time. The amount of loop control can be stably performed.

Industrial availability

As described above, the wire rod splitting method in the wire rod rolling equipment of the present invention is useful as a means for dividing the wire rod rolled by a rolling sequence of a plurality of rolling mills on a line, and in particular, a plurality of wire rod coils are manufactured from one steel piece. It is suitable for use in installations.

Claims (2)

A looper 17 for forming a suitable loop in the wire rods 3 of the rolling mills ST _i and ST _{i + 1} , and a kicker 18 discharging the wire rod 3 toward the looper 17. And the rolling speed of the wire rod 3 integrated until the tip of the wire rod 3 reaches a predetermined position upstream of the kicker 18 until the kicker 18 operates. The integral value is stored as a kicker operation timing reference value, and the rolling speed of the subsequent wire 3b is integrated from the point when the subsequent wire 3b after cutting by the flying shear 4 reaches the predetermined position. When the integral value for the subsequent wire 3b becomes the kicker operation timing reference value, the kicker is operated to expel the subsequent wire 3b to the looper 17. Wire splitting method. The looper 17 for forming a suitable loop on the wire rod 3 between the rolling mills ST _i and ST _{i + 1} and the loop amount of the wire rod 3 in the looper 17 And a loop amount control system 39 for outputting the speed correction values of the rolling mills ST _i and ST _{i + 1} so as to be kept constant, wherein the speed correction values from the loop amount control system 39 correspond to the preceding wire 3a. The wire rod in the wire rod rolling equipment, characterized in that it is calculated independently of the split speed command value when giving the relative speed difference to the subsequent wire rod 3b and is output to the rolling mills ST _i and ST _{i + 1} . Division method.