Shearing control method for preventing short end from being sheared by flying shear before high-speed wire finishing

Abstract

The present application relates to the field of wire rod rolling, and particularly relates to a shearing control method for controlling a flying shear not to cut a short head before high wire finish rolling. The method comprises the following steps: when detecting that a wire rod moves to a distance of n1 from the flying shear, performing peak speed adjustment on a shearing blade of the flying shear, so that the shearing blade of the flying shear approaches a specified position as much as possible at a T1 moment; when detecting that the wire rod moves to a distance of n2 from the flying shear, recording a T2 moment; recording a standard period s0 as a period in which the shearing blade reaches a zero position at a T4 moment; recording a T3 moment as a moment corresponding to a starting position of a turner in the standard period s0; recording a T3' moment as a moment corresponding to a last starting position of the turner before the T4 moment, and the period in which the starting position is located is an mth period of the flying shear; if T3-T3'> (L1-L2) / V, controlling the turner to start in an m+1th period of the flying shear, otherwise, controlling the turner to start in the mth period of the flying shear. The present application can ensure that the flying shear does not produce short head shearing before finish rolling in the case of fluctuation of shearing blade position pre-adjustment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wire rod rolling, in particular to a shearing control method for controlling the fly shear before high wire rod finishing rolling to not cut short head. BACKGROUND

[0002] The fly shear before finishing rolling is one of the most important devices in high speed wire rod production. Here, the Morgan 5th generation device in a certain high speed wire rod plant is taken as an example. The fly shear before the finishing rolling mill is No. 3 fly shear. The main function of No. 3 fly shear is to cut the head and tail of red steel before entering the finishing rolling mill, and to cut the material and send it to the scrap shear for scrap when the finishing rolling fails, so as to avoid a large amount of steel storage damage to the equipment.

[0003] After the No. 3 fly shear cuts the short head, the short head remains in the steel passing groove, and the subsequent short head is brought into the rolling mill or the pipe and is blocked, which will cause a large amount of steel storage, and has a great influence on production. The No. 3 fly shear cuts the short head, which is based on the Morgan No. 3 fly shear of a certain high speed wire rod plant. The fly shear is a continuous fly shear, and a shear blade is provided on the fly wheel. The width of the shear blade is 4 cm, and the shear blade is located in the middle of the steel passing groove and the scrap groove. The red steel does not contact the shear blade at the steel passing position and the scrap position. There is a turner in front of the shear blade to control the swing of the steel between the steel passing position and the scrap position. The cutting is completed in the swing process. The head and tail after cutting will enter the scrap shear along the scrap groove.

[0004] The Morgan No. 3 fly shear is controlled by two thermal detectors. The first one is used for pre-positioning of the shear blade. The second one is used for controlling the delay action of the turner. The calculated speed of the fly shear is the actual rolling speed of the sampled front stand. After sampling is completed, the delay action of the turner is controlled according to the length of the cut head and the cooperation time of the turner. According to incomplete statistics, since the production of a certain high speed wire rod plant, there have been more than one hundred steel storages caused by short head in more than ten years.

[0005] As can be seen from the above, in order to cut well, the fly shear must be cooperated by the position of the shear blade and the turner. The turner can be used to adjust the position of the shear blade, but if the position of the shear blade is not suitable, the turner cannot complete the cutting under the condition of ensuring the length of the cut head, at this time, there is a risk of short head. Sometimes there is some deviation in the pre-adjustment position of the shear blade, and various mechanical characteristics and slight changes in transmission capacity also have some influence on it. Therefore, in this case, it is necessary to control the fly shear to not cut short head through control means. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the defects of the prior art, and to provide a shearing control method for controlling the fly shear before high wire rod finishing rolling to not cut short head, which can ensure that the fly shear before finishing rolling does not produce short head cutting under the condition that the pre-adjustment position of the shear blade fluctuates.

[0007] In order to solve the above technical problems, the technical scheme of the present application is: a shearing control method for controlling the flying shear not to cut short head before the high-speed wire finishing rolling, the flying shear is a continuous disc shear, and is used for shearing the wire in the process that the turner is actuated to make the turner guide pipe drive the wire to swing, the method comprises the steps of:

[0008] When the wire is detected to move to a distance of n1 from the flying shear, the shearing blade of the flying shear is subjected to peak speed regulation, so that the shearing blade of the flying shear is as close as possible to the specified position at T1 moment, and when the wire is detected to move to a distance of n2 from the flying shear, the moment is recorded as T2 moment; wherein the specified position is the starting position of the shearing blade to reach the zero position at T4 moment, T4=T2+(n2+L1) / V, L1 is the standard cut length, V is the linear velocity of the wire (5), n2

[0009] The period in which the shearing blade reaches the zero position at T4 moment is recorded as a standard period s0, the moment corresponding to the starting position of the turner in the standard period s0 is recorded as T3 moment, the moment corresponding to the last starting position of the turner before T4 moment is recorded as T3' moment, and the period of the starting position is the mth period of the flying shear; wherein the starting position is the position of the shearing blade when the turner is started from the broken position in cooperation with the flying shear.

[0010] If T3-T3'>(L1-L2) / V, the turner is controlled to be started from the broken position at the starting position of the m+1th period of the flying shear, otherwise, the turner is controlled to be started from the broken position at the starting position of the mth period of the flying shear; wherein L2 is the shortest cut length.

[0011] Further, the peak speed regulation of the flying shear is performed; specifically:

[0012] First, the linear velocity of the shearing blade is uniformly increased from V0 to V1, and then uniformly decreased to V0.

[0013] Further, the T3' moment is determined according to the position of the shearing blade at the T2 moment and the rotating speed of the flying shear.

[0014] Further, the calculation formula of the starting position is:

[0015] a%*s=(C / V0-t1) / (C / V0)*s;

[0016] Wherein, s represents a period of the flying shear, C represents the distance of the shearing blade of the flying shear rotating one period, V0 represents the linear velocity of the shearing blade; t1 represents the time for the turner to swing from the broken position to the shearing position; a%*s represents the starting position.

[0017] Further, n1 is 27m, and n2 is 5.5m.

[0018] Further, L1 is 1.5m, and L2 is 0.7m.

[0019] The application also provides a shearing control method for controlling the non-short-end shearing of a flying shear before high-speed wire finishing rolling, the flying shear being a continuous disc shear used for shearing the wire during the process of swinging the wire by the guide pipe of the turner, the method comprising:

[0020] When the wire is detected to move to a distance n1 from the flying shear, the shearing blade of the flying shear is subjected to peak speed regulation, so that the shearing blade can reach a specified position as much as possible at T1; when the wire is detected to move to a distance n2 from the flying shear, the time is recorded as T2; wherein the specified position is a starting position for the shearing blade to reach zero position at T4, T4=T2+(n2+L1) / V, L1 is the standard cut length, V is the wire speed, n2

[0021] The period in which the shearing blade reaches zero position at T4 is recorded as a standard period s0, and the starting position of the turner in the standard period s0 is recorded as a standard starting position a%*s0; the last starting position of the turner before T4 is recorded as an actual starting position a%*s, and the period in which the actual starting position a%*s is located is the mth period of the flying shear; wherein the starting position is the position of the shearing blade when the turner is started from the broken position in cooperation with the flying shear.

[0022] The wire speed V0 of the shearing blade is equal to the wire speed V of the wire, if the time T3' corresponding to the actual starting position a%*s is earlier than the time T3 corresponding to the standard starting position a%*s0 by more than (L1-L2) / C*t2, the turner is controlled to be started from the broken position at the starting position in the m+1th period of the flying shear, otherwise, the turner is controlled to be started from the broken position at the starting position in the mth period of the flying shear; wherein L2 is the shortest cut length, C is the distance of the shearing blade rotating one period, and t2 is the time length of the shearing blade normally rotating one period without peak speed regulation.

[0023] After the shearing length fluctuation of the flying shear after the pre-adjustment exceeds the acceptable length, the shearing is delayed, so that the situation of the flying shear cutting short end before the finishing rolling is completely eliminated in the case of effective shearing blade position, and the probability of cutting long end is controlled to be infinitely low under the condition of no short end cutting. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a shearing action schematic diagram of the flying shear before the finishing rolling;

[0025] Figure 2 It is a speed change curve diagram of one peak speed regulation of the flying shear;

[0026] Figure 3 It is a matching diagram of the shearing blade position and the turner when T3' time coincides with T3 time;

[0027] Figure 4 The diagram showing the matching of the shear blade position and the deflector at time T3' relative to the forward offset at time T3;

[0028] Figure 5 The diagram showing the matching of the shear blade position at time T3' relative to the time after T3 with the deflector;

[0029] Figure 6 A schematic diagram for setting the upper limit of the forward bias within a standard period;

[0030] Figure 7 This is a flowchart of the shear control method of the present invention;

[0031] In the diagram, 1. Breaking groove; 2. Steel passage groove; 3. Post-shearing triangular plate; 4. Conduit for turning device; 5. Wire; 6. Shear blade;

[0032] Figure 1 (a) is a schematic diagram of the structure of the turning device located at the fracture point; Figure 1 (b) is a schematic diagram of the structure of the turning device located at the steel position. Detailed Implementation

[0033] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0034] like Figure 1 As shown, the flying shear before finishing milling is a continuous disc shear used to cut wire 5 during the process of the deflector guide 4 oscillating the wire 5 as the deflector actuates. The flying shear is controlled by a large motor to continuously rotate the flywheel, and cutting is performed by coordinating the position of the deflector and the position of the shear blade 6. The flying shear's encoder can detect the position in real time. This flying shear only has head-cutting and tail-cutting functions, and the control principles of these two functions are similar. The following description in this patent mainly focuses on head-cutting.

[0035] like Figure 1 As shown, Figure 1is the head control principle of the flying shear, the initial position of the turner is the breaking position, and the turner guide pipe 4 points to the breaking groove 1. If the turner does not act, the wire 5 (red steel) comes and directly enters the breaking shear through the breaking groove 1 for breaking. When the head of the wire 5 (red steel) enters the breaking groove, and the distance between the red steel head position and the shear blade reaches the standard head length L1. The turner quickly swings from the breaking position to the steel passing position. The whole swing action is about 10 cm in the transverse direction. When the turner swings to the middle (shearing position), the shear blade 6 just coincides to cut off the wire 5 (red steel). It should be noted that the red steel does not touch the shear blade 6 in the steel passing position and the breaking position. The flying shear blade rotates one circle for 2.532 meters. The cut-off material head enters the breaking shear along the breaking groove 1, and the following red steel enters the steel passing groove 2 to continue rolling in the subsequent finishing mill. It should be noted that the linear speed of the shear blade 6 is generally equal to the linear speed of the wire 5, of course, it can also be unequal.

[0036] As shown in Figures 2 to 7 A shearing control method for controlling the flying shear of a high-speed wire finishing mill to not cut short heads, the method comprising:

[0037] detecting that the wire 5 moves to a position at a distance n1 from the flying shear, performing peak speed regulation on the shear blade 6 of the flying shear, so that the shear blade 6 of the flying shear is as close as possible to the specified position at T1, detecting that the wire 5 moves to a position at a distance n2 from the flying shear, recorded as T2; wherein the specified position is the starting position of the shear blade 6 to reach the zero position at T4, T4 = T2 + (n2 + L1) / V, L1 is the standard head length, V is the linear speed of the wire (5), n2 < n1, T2 - T1 > 0;

[0038] the period in which the shear blade 6 reaches the zero position at T4 is recorded as the standard period s0, the time corresponding to the starting position of the turner in the standard period s0 is recorded as T3, the time corresponding to the last starting position of the turner before T4 is recorded as T3', and the starting position is in the mth period of the flying shear; wherein the starting position is the position of the shear blade 6 when the turner starts from the breaking position in cooperation with the flying shear;

[0039] if T3 - T3' > (L1 - L2) / V, the turner is controlled to start from the starting position in the m+1th period of the flying shear, otherwise, the turner is controlled to start from the starting position in the mth period of the flying shear; wherein L2 is the minimum head length.

[0040] It should be noted that two thermal detectors are arranged on the production line, and the first thermal detection signal is received, that is, the head end of the wire 5 moves to a position at a distance n1 from the flying shear, and the second thermal detection signal is received, that is, the head end of the wire 5 moves to a position at a distance n2 from the flying shear.

[0041] In one embodiment, the flying shear blade 6 is accelerated; specifically, the linear speed of the blade 6 is first uniformly increased from V0 to V1, and then uniformly decreased to V0.

[0042] Figure 2 is a curve of the actual PDA graph of the flying shear blade 6 acceleration. The above graph is a speed curve of the flying shear acceleration, which is increased from about 10.75 m / s to 12.25 m / s (an example), and then decreased to form a peak acceleration. Figure 2 The following graph is a flying shear cycle. When the wire 5 moves to a distance of n1 from the flying shear, i.e., the first hot detection signal arrives, the position of the blade 6 is random at this time, and the blade 6 needs to be adjusted to the specified position to match the position of the wire 5 (billet) head at this time. Therefore, a peak acceleration is sent in the program. The height of the peak has a range, but each steel is different. The area of the triangle formed by the peak is the adjustment value of the blade angle (position). As can be seen from the curve, due to changes in mechanical properties, transmission capacity, performance, control delay, and many other factors, the actual speed after adjustment cannot be a perfect peak triangle. Therefore, the actual adjustment angle cannot be very accurate, and can only be as close to the specified position as possible. Figure 2 As shown, the peak acceleration time can be 1 s.

[0043] In one embodiment, the time T3' is determined according to the position of the blade 6 at time T2 and the flying shear speed.

[0044] In one embodiment, the calculation formula of the starting position is:

[0045] a% * s = (C / V0-t1) / (C / V0) * s;

[0046] Where s represents a cycle of the flying shear, C represents the distance of the blade 6 in one cycle of the flying shear, V0 represents the linear speed of the blade 6, t1 represents the time for the turner to swing from the breaking position to the shearing position, and a% * s represents the starting position.

[0047] In one embodiment, n1 is 27 m, and n2 is 5.5 m. It should be noted that n2 can also have other values, as long as the value of n2+L1 is the distance of two multiple cycles of the blade 6.

[0048] In one embodiment, L1 is 1.5 m, and L2 is 0.7 m. The value of L1 is 1.5 m, which is the normal cutting length in the field production, and the value of L2 is 0.7 m, which is obtained according to relevant experience of high-speed wire. If the actual cutting length is lower than 0.7 m, there is a risk of short head steel.

[0049] The following will be described in conjunction with the accompanying drawings Figure 3 to the accompanying drawings Figure 6The above-mentioned embodiments are described in detail.

[0050] As Figure 3 shown, Figure 3 is a standard match chart of the turner and the shear blade, that is, the match chart of the shear blade position and the turner when the T3' time coincides with the T3 time. The time between the left and right red lines is the cycle judgment time of the flying shear standard, which is the time for the flying shear to rotate one cycle at the current speed. The standard cycle s0 of the flying shear is represented by the two red lines. The T4 time corresponding to the right red line corresponds to 360° (0°) of the shear blade 6. At this time, the shear blade 6 coincides, and the turner is just in place. The cut length at this time is the set length L1, which is the ideal control state. The actual control state cannot make the shear blade 6 coincide with the T4 time corresponding to the right red line at 360° (0°). The shear blade 6 can cut at the left and right of the T4 time corresponding to the right red line, but the length will increase or decrease accordingly. Figure 3 The sawtooth pattern below represents the angle transformation of the flying shear rotation, which is periodic from 0 to 360 continuous change. At this time, the shear blade 6 is a waveform that has been pre-adjusted by peak speed adjustment. This waveform continues until the cutting is completed. Figure 3 The medium green line is the time corresponding to the start angle (start position) at which the turner actually starts to act. This is a value calculated according to the turning action time and the cut length.

[0051] As Figure 4 shown, Figure 4 is a schematic diagram of the cutting situation under the condition of forward deviation. The best state is to adjust the shear blade coincidence time to the T4 time corresponding to the right red line, but in fact, after adjusting the position, the shear blade deviates to the left (forward deviation), and the shear blade coincidence time deviates to the left. The T3' time corresponding to the start position deviates to the left, and the T3' time corresponding to the start position deviates to the left. At this time, the flying shear will choose to cut at the T3' time corresponding to the start position of the actual cycle in order to ensure cutting. At this time, the T3' time is ahead of the T3 time corresponding to the start position of the standard cycle s0, so the cut length will be shortened.

[0052] As Figure 5 shown, Figure 5This is a diagram illustrating the shearing process with a backward offset. Ideally, the blade overlap time should be adjusted to precisely the T4 time corresponding to the red line on the right. However, in reality, after adjusting the position, there's a rightward offset (backward offset), causing the overlap time to shift to the right. The T3' time corresponding to the starting position is between the two red lines of the standard flying shear cycle s0. To ensure a cut, the flying shear will choose to cut at the T3' time corresponding to the starting position of the actual cycle. At this point, the T3' time lags behind the T3 time corresponding to the starting position of the standard cycle s0, effectively shifting to the right, resulting in a longer cut length. Because the cycle is cyclical... Figure 3 , Figure 4 The green line in the diagram corresponds to the last starting position of the deflector before time T4, so it will never exceed the left and right red lines.

[0053] like Figure 6 As shown, Figure 6 This is a schematic diagram with an added upper limit line for forward deviation based on the standard diagram. This diagram is the focus of this invention. Since this control method is mainly used to prevent short-end cutting, a short end is defined as within 0.7 meters (risk of steel blockage). Therefore, we need to add an upper limit line for forward deviation, i.e., a purplish-red line, between the first red and green lines. When the green line representing time T3' shifts too far to the left (too large a deviation), once it exceeds the purplish-red line, the current shearing cannot be initiated in the current cycle (because the starting point has exceeded the upper limit). This avoids short-end cutting. Our normal cutting length is 1.5m. The minimum allowable shortest end is 0.7m. That is, the maximum deviation cannot exceed 0.8m. The left deviation time corresponding to 0.8m is 0.8 / V, so the time of the upper limit line for forward deviation is T3-0.8 / V. Therefore, if the green line representing time T3' shifts to the left of the upper limit line for forward deviation (purplish-red line), i.e., T3' < T3-0.8 / V, it indicates a short end. The turning device will not be initiated in the current cycle, but will be initiated at the starting position of the next cycle.

[0054] The formula for calculating the upper limit of the forward deviation time is (L1-L2) / V. Since the normal linear velocity V0 of the shear blade 6 is equal to the linear velocity V of the wire 5, when converted to the flying shear cycle, it becomes (L1-L2) / C. (L1-L2) / V and (L1-L2) / C are directly proportional. If the flying shear cycle is used as the unit to determine in which cycle the switching device should be activated, then if the forward deviation exceeds (L1-L2) / C of the flying shear cycle, the switching device should not be activated in the current cycle, but should be activated at the starting position of the next cycle. Otherwise, the switching device should not be activated in the current cycle.

[0055] By automatically calculating the upper limit of the shearing time (the upper limit of the shearing cycle) of the wire with different specifications and different speeds, the position where the upper limit is located, and the situation where the short head appears, the wire is cut again after one more turn to avoid setting a fixed value which can not cut the short head but often cut again after one more turn to cause great loss of the yield. By increasing the difference upper limit, enough space can be left for the shearing cycle. Although the transmission speed cannot be very accurate, the fluctuation range is limited and normally distributed (99.99% of the fluctuation is within 60 cm). Therefore, when the upper limit always leaves enough time and space of (L1-L2) / V (the normal linear speed of the shearing blade 6 V0 is equal to the linear speed of the wire 5 V, corresponding to the flying shear cycle, that is, leaving enough cycle space of (L1-L2) / C), it can ensure that the green line corresponding to the T3' time is later (right) than the purple red corresponding to the front bias upper limit line, and as little as possible to cut, and it can also ensure that the green line corresponding to the T3' time is in front of (left) the purple red corresponding to the front bias upper limit line, and there is no short head.

[0056] A certain steel rolling plant did not have the problem of cutting short head within one year after applying the above control method.

[0057] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and must be determined according to the scope of the claims.

Claims

1. A shearing control method for controlling a flying shear not to cut a short head before finishing of a high line, the flying shear being a continuous flying shear for shearing a wire (5) in a process in which a tumbler guide (4) swings the wire (5) by action of a tumbler, characterized in that the method comprises: detecting that the wire (5) moves to a distance of n1 from the flying shear, and performing a peak speed control of a shear blade (6) of the flying shear so that the shear blade (6) reaches a specified position as close as possible at a time T1, detecting that the wire (5) moves to a distance of n2 from the flying shear at a time T2, wherein the specified position is a start position at which the shear blade (6) reaches a zero position at a time T4, T4 = T2 + (n2 + L1) / V, L1 is a standard cut length, V is a wire speed of the wire (5), n2 < n1, and T2 - T1 > 0; regarding a period in which the shear blade (6) reaches the zero position at the time T4 as a standard period s0, regarding a time corresponding to a start position of the tumbler in the standard period s0 as a time T3, regarding a time corresponding to a last start position of the tumbler before the time T4 as a time T3', and regarding a period in which the start position is located as an mth period of the flying shear, wherein the start position is a position of the shear blade (6) when the tumbler starts from a break position; and if T3 - T3' > (L1 - L2) / V, controlling the tumbler to start from the break position at a start position of an m + 1th period of the flying shear, otherwise, controlling the tumbler to start from the break position at the start position of the mth period of the flying shear, wherein L2 is a minimum cut length.

2. The shearing control method according to claim 1, characterized in that the peak speed control of the flying shear is performed by: first increasing a wire speed of the shear blade (6) from V0 at a constant speed to V1, and then decreasing the wire speed at a constant speed to V0.

3. The shearing control method according to claim 1, characterized in that the time T3' is determined according to a position of the shear blade (6) at the time T2 and a rotation speed of the flying shear.

4. The shearing control method according to claim 1, characterized in that a calculation formula of the start position is: a% * s = (C / V0 - t1) / (C / V0) * s, wherein s represents a period of the flying shear, C represents a distance of the shear blade (6) when the flying shear rotates one period, V0 represents the wire speed of the shear blade (6), t1 represents a time for the tumbler to swing from the break position to a shearing position, and a% * s represents the start position.

5. The shearing control method according to claim 1, characterized in that n1 is 27 m, and n2 is 5.5 m.

6. The shearing control method according to claim 1, characterized in that L1 is 1.5 m, and L2 is 0.7 m.

7. A shearing control method for controlling a flying shear not to cut a short head before finishing of a high line, the flying shear being a continuous flying shear for shearing a wire (5) in a process in which a tumbler guide (4) swings the wire (5) by action of a tumbler, characterized in that the method comprises: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ When the wire rod (5) is detected to move to a distance of n1 from the flying shear, the shear blade (6) of the flying shear is controlled to have a peak speed, so that the shear blade (6) of the flying shear is as close as possible to a specified position at T1; when the wire rod (5) is detected to move to a distance of n2 from the flying shear, the time is recorded as T2; wherein the specified position is a starting position for the shear blade (6) to reach zero position at T4, T4 = T2 + (n2 + L1) / V, L1 is a standard cut length, V is a wire speed of the wire rod (5), n2 < n1, T2-T1>0; A cycle in which the shear blade (6) reaches zero position at T4 is recorded as a standard cycle s0, a starting position of the turner in the standard cycle s0 is recorded as a standard starting position a%*s0; a last starting position of the turner before T4 is recorded as an actual starting position a%*s, and a cycle in which the actual starting position a%*s is located is the mth cycle of the flying shear; wherein the starting position is a position of the shear blade (6) when the turner starts from the broken position; The wire speed V0 of the shear blade (6) is equal to the wire speed V of the wire rod (5), if the actual starting position a%*s corresponds to a time T3' that is ahead of a time T3 corresponding to the standard starting position a%*s0 by more than (L1-L2) / C*t2, the turner is controlled to start from the broken position at a starting position in the m+1th cycle of the flying shear, otherwise, the turner is controlled to start from the broken position at a starting position in the mth cycle of the flying shear; wherein L2 is a shortest cut length, C is a distance of the shear blade (6) rotating one cycle, and t2 is a time length of the shear blade (6) rotating one cycle.

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