Large-specification wire rod tail ring shape control method

Abstract

The invention relates to a large-specification wire rod tail ring shape control method, and belongs to the technical field of high-speed wire rod production methods. According to the technical scheme, when the speed of the tail portion is increased, synchronous speed increasing of a silking machine and a pinch roll is changed into asynchronous speed increasing control, and lagging speed increasing of the silking machine is adopted; when the speed of the rolled piece starts to rise stably, the silking machine rises synchronously; the air-cooling roller way stops running when spinning is performed for the last number of circles, so that the tail coils fall to one position of the air-cooling roller way in a concentrated manner; and after the rolled piece is separated from the pinch roll and the silking machine, the pinch roll and the silking machine return to normal speeds, the air cooling roller way returns to normal operation, and next steel is prepared for silking. The device has the beneficial effects that the regular forming of the tail ring of the large-specification special steel wire is realized, the impact on equipment caused by the acceleration of a reducing and sizing unit is avoided, and two flexibly adjustable parameters can be suitable for the ring shape adjustment of products with various specifications, steel types and spinning temperatures.

Description

Technical Field

[0001] The invention relates to a method for controlling the coil shape of a large-size wire tail, and belongs to the technical field of high-speed wire production methods. Background Art

[0002] The product specifications of a typical advanced high-speed wire production line range from Φ5mm to Φ28mm. In order to ensure that the tail of the wire can be smoothly spun after leaving the last stand rolling mill, and obtain a standardized coil shape for subsequent collection and packaging, a pinch roller is installed in front of the wire laying machine. When the tail of the wire leaves the last stand rolling mill and loses the forward momentum, the rotating pinch roller clamps the rolled piece, so that the tail of the rolled piece moves forward at a certain speed. At this time, the speed of the wire laying machine automatically matches it, so that the tail of the wire can be smoothly spun.

[0003] Since the tail of the wire rod completely relies on inertia to form and spit out the wire in the spinning tube after leaving the pinch roller, the tail speed increase method is adopted for large-size products to increase the kinetic energy of the tail of the wire rod, so that the tail end has enough inertia to form and spit out smoothly in the spinning tube after leaving the pinch roller. The tail speed increase is achieved by clamping the rolled piece with the front pinch roller of the spinning machine to increase the speed. In this process, the spinning machine and the pinch roller speed up synchronously to ensure that the coil shape remains unchanged.

[0004] For large-size special steel wires of Φ16mm-Φ28mm, due to its low spinning temperature, small friction coefficient on the wire surface, high alloy content, and large deformation resistance in the spinning tube at a low temperature, and due to its heavy weight, large friction between the rolled piece and the steel passage. The combined effect of the above factors leads to the phenomenon that the actual speed of the wire is instantaneously low in the initial stage of speed increase when the tail speed is increased only by the pinch roller. At this time, the linear speed of the rolled piece is lower than the linear speed of the spinning machine, resulting in a small circle in the spinning, which has an adverse effect on subsequent collection and packaging.

[0005] Another problem with large-sized tail rings is that there are several loose rings at the tail. Due to the large diameter, after cooling on the air cooling line, the ring shape is fixed and it is difficult to regularize it again during subsequent collection and packaging, resulting in a fan-shaped distribution of the tail rings, affecting the packaging quality.

[0006] Patents CN 117299787 A and CN 103372565 B disclose a method for optimizing the speed increase of the tail of medium and large-sized wire rods, which solves this problem by increasing the speed of the pinch rollers and the sizing machine at the same time. In this method, the speed of the tail sizing machine unit of each steel bar will rise and fall rapidly once, which has an adverse effect on the life of the motor, gears and bearings, and no solution is proposed for the loose coils at the tail. Summary of the invention

[0007] The purpose of the present invention is to provide a method for controlling the coil shape of the tail of a large-sized wire rod. The method solves the problem of small coils by changing the synchronous speed increase of the original laying machine and the pinch roller to an asynchronous speed increase, and solves the problem of loose coils at the tail by pausing the air-cooled roller at the tail of the laying, thereby achieving regular shaping of the tail coils of large-sized special steel wire rods, avoiding the impact on the equipment caused by the speed increase of the sizing unit, and two flexibly adjustable parameters can be applied to the coil shape adjustment of products of various specifications, steel grades, and laying temperatures, effectively solving the above-mentioned problems existing in the background technology.

[0008] The technical solution of the present invention is: a method for controlling the coil shape of a large-sized wire tail, comprising the following steps: Step S1: When the speed of the tail is increased, the speed of the laying head and the pinch roller is changed from synchronous speed increase to asynchronous speed increase control, and the laying head adopts delayed speed increase; Step S2: When the speed of the rolled piece starts to increase steadily, the laying head increases its speed synchronously; Step S3: the air-cooling roller stops running when spinning the last few turns, so that the tail coils fall to one position on the air-cooling roller; Step S4: After the rolled piece is separated from the pinch rollers and the laying head, the pinch rollers and the laying head resume normal speed, and the air-cooled roller table resumes normal operation to prepare for the next steel laying.

[0009] A delay adjustment window is added to the speed control program of the spinning machine and the pinch roller, and the adjustment range of the delay adjustment window is 0-1000 milliseconds.

[0010] In the step S1, a 1# hot metal detector is installed at the outlet of the sizing mill to detect the time when the tail of the rolled piece leaves the sizing mill. When the tail of the rolled piece leaves the sizing mill, the pinch rollers start to increase speed according to the set speed increase slope and maximum speed value. After the pinch rollers start to increase speed, the laying machine increases speed after the speed delay set in the delay adjustment window.

[0011] The speed delay setting of the delay adjustment window matches the coil shape spitted out by the spinning machine at the initial stage of the pinch roller speed increase.

[0012] In step S3, a 2# hot metal detector is installed 16-20 meters in front of the laying head. When the tail of the rolled piece runs to this position, the hot metal detector sends a signal. After a delay of the length set in the delay adjustment window, the air-cooled roller table is suspended, so that the tail coils spit out by the laying head are concentrated at one position of the roller table to avoid the formation of loose coils.

[0013] The length delay set in the delay adjustment window matches the number of coil turns that need to be concentrated.

[0014] In step S4, a 3# hot metal detector is installed in front of the laying head to detect the tail position of the rolled piece.

[0015] The beneficial effects of the present invention are as follows: the problem of small coils is solved by changing the synchronous speed increase of the original laying head and the pinch roller to an asynchronous speed increase, and the problem of loose coils at the tail is solved by pausing the air-cooled roller at the tail of the laying, thereby achieving regular shaping of the tail coils of large-size special steel wires, avoiding the impact on the equipment caused by the speed increase of the diameter identification unit, and the two flexibly adjustable parameters can be applied to the coil shape adjustment of products of various specifications, steel types and laying temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a tail circle type physical picture of the background technology; Figure 3 This is a real picture of the tail ring type of the present invention; In the figure: 1# hot metal detector 1, 2# hot metal detector 2, 3# hot metal detector 3, sizing machine 4, water tank 5, pinch roller and laying head 6, air cooling roller table 7. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] A method for controlling the coil shape of a large-gauge wire tail comprises the following steps: Step S1: When the speed of the tail is increased, the speed of the laying head and the pinch roller is changed from synchronous speed increase to asynchronous speed increase control, and the laying head adopts delayed speed increase; Step S2: When the speed of the rolled piece starts to increase steadily, the laying head increases its speed synchronously; Step S3: the air-cooling roller stops running when spinning the last few turns, so that the tail coils fall to one position on the air-cooling roller; Step S4: After the rolled piece is separated from the pinch rollers and the laying head, the pinch rollers and the laying head resume normal speed, and the air-cooled roller table resumes normal operation to prepare for the next steel laying.

[0019] A delay adjustment window is added to the speed control program of the spinning machine and the pinch roller, and the adjustment range of the delay adjustment window is 0-1000 milliseconds.

[0020] In the step S1, a 1# hot metal detector is installed at the outlet of the sizing mill to detect the time when the tail of the rolled piece leaves the sizing mill. When the tail of the rolled piece leaves the sizing mill, the pinch rollers start to increase speed according to the set speed increase slope and maximum speed value. After the pinch rollers start to increase speed, the laying machine increases speed after the speed delay set in the delay adjustment window.

[0021] The speed delay setting of the delay adjustment window matches the coil shape spitted out by the spinning machine at the initial stage of the pinch roller speed increase.

[0022] In step S3, a 2# hot metal detector is installed 16-20 meters in front of the laying head. When the tail of the rolled piece runs to this position, the hot metal detector sends a signal. After a delay of the length set in the delay adjustment window, the air-cooled roller table is suspended, so that the tail coils spit out by the laying head are concentrated at one position of the roller table to avoid the formation of loose coils.

[0023] The length delay set in the delay adjustment window matches the number of coil turns that need to be concentrated.

[0024] In step S4, a 3# hot metal detector is installed in front of the laying head to detect the tail position of the rolled piece.

[0025] In practical applications, a delay adjustment window is added to the speed control program of the laying head and the pinch roller, and the time adjustment range is: 0-1000 milliseconds, and this time is defined as T1.

[0026] A 1# hot metal detector is installed at the exit of the sizing mill to detect the time when the tail of the rolled piece leaves the sizing mill. When the tail of the rolled piece leaves the sizing mill, this moment is defined as T0, and the pinch roller of the laying head begins to increase speed according to the set speed increase slope and maximum speed value.

[0027] After the speed of the spouting machine's pinch rollers begins to increase, after a delay of T1, the spouting machine begins to increase speed according to the set speed increase slope, so the time when the speed of the spouting machine begins to increase is T0+T1.

[0028] At this time, the actual speed of the rolled piece can be kept consistent with the linear speed of the pinch roller rotation and the linear speed of the spinning machine, thus eliminating the small spinning circle at the tail caused by the low actual linear speed of the rolled piece due to inertia and resistance in the initial stage of the rolled piece speed increase.

[0029] A 2# hot metal detector is installed 16-20 meters in front of the spinning machine. When the tail of the rolled piece runs to this point, the hot metal detector sends a signal. After a delay T2, the air-cooled roller stops running, so that the last 3-5 turns of the tail spitted out by the spinning machine are concentrated in one position of the roller to avoid the formation of loose turns.

[0030] By adjusting the delay length, the number of wire coils that fall in the end can be accurately controlled. The delay length T2 is automatically calculated by the control degree according to the number of coils that need to be concentrated. The calculation method is as follows: The diameter of the spinning disk is 1020mm, and the length of the wire for one spinning circle is: 3.14*1.02=3.2 (meters).

[0031] If you want the last N turns of wire to fall onto the air-cooled roller for collection, the total length of the wire L is: L = 3.2*N (meters) Assuming that the distance between 2# heat detection and spinning machine is 16 meters, then T2 = (16-L) / V (seconds) V is the linear speed of the pinch roller (m / s).

[0032] A 3# hot metal detector is installed in front of the laying head to detect the position of the tail of the rolled piece. When the tail is separated from the laying head, the pinch roller and the laying head resume their initial speed, and at the same time the air-cooled roller resumes normal speed to prepare for rolling the next piece of steel. Example

[0033] Taking Φ22mm bearing steel wire as an example, combined with Figure 1 , explain the specific implementation methods.

[0034] The normal rolling speed of this specification wire is 12m / s, and the tail is accelerated to 28m / s to ensure smooth spinning of the tail of the wire. During normal rolling, the outlet speed of the sizing unit is 12m / s, the idling speed of the laying machine pinch roller is 12.6m / s (speed leading rate 5%), and the line speed of the laying machine is 13.2m / s (speed leading rate 10%).

[0035] Install 1# hot metal detector 1-5 meters in front of the sizing mill, install 2# hot metal detector 16 meters away from the pinch roller, and install 3# hot metal detector in front of the pinch roller of the spinning machine.

[0036] When the 1# hot metal detector changes from the steel-containing state to the steel-free state, the pinch roller starts to increase its speed according to the set slope.

[0037] Set the delay window for the speed increase of the spinning machine to 100 milliseconds, and observe the shape of the rings spit out by the spinning machine at the initial stage of the pinch roller speed increase. If it is too small, increase the delay window to 200 milliseconds. If it is too large, reduce the delay to 50 milliseconds.

[0038] Repeat the above process until a suitable delay value is set so that there is no small or large circle during the entire process of the pinch roller speed increase.

[0039] When the signal of the 3# hot metal detector changes from steel to no steel, it means that the rolled piece has completely passed through the pinch rollers, and the pinch rollers have resumed their initial speed before speeding up, ready to roll the next piece of steel.

[0040] If you want the wire tail to have 4 turns concentrated on the roller, then: The length of 4 turns of wire is: 4*3.2=12.8 meters When the air-cooling roller table starts to pause, the distance between the tail of the wire and the 2# hot metal detector is: 16-12.8=3.2 (meters) The wire speed is 28 m / s at this time. The time from when the 2# hot metal detector detects that there is no steel to when the roller starts to pause is: 3.2 / 28=0.114 (seconds).

[0041] That is, the roller starts to pause after 0.114 seconds after the 2# hot metal detector detects that there is no steel, and the roller stops pausing and resumes moving forward after there is no steel at the 3# hot metal detector.

[0042] Through the above method, the number of circles in which the tail falls can be flexibly adjusted within 0-5 circles.

[0043] When the 3# hot metal detector detects that there is no steel and the tail of the wire has completely left the laying head, the pinch roller and the laying head return to the initial speeds of 12.6m / s and 13.2m / s, and the air-cooled roller resumes normal operation, preparing for the next steel head to be laid.

Claims

1. A method for controlling the coil shape of a large-sized wire tail, characterized in that The following steps are involved: Step S1: When the speed of the tail is increased, the speed of the laying head and the pinch roller is changed from synchronous speed increase to asynchronous speed increase control, and the laying head adopts delayed speed increase; Step S2: When the speed of the rolled piece starts to increase steadily, the laying head increases its speed synchronously; Step S3: the air-cooling roller stops running when spinning the last few turns, so that the tail coils fall to one position on the air-cooling roller; Step S4: After the rolled piece is separated from the pinch rollers and the laying head, the pinch rollers and the laying head resume normal speed, and the air-cooled roller table resumes normal operation to prepare for the next steel laying.

2. A method for controlling the coil shape of a large-sized wire tail according to claim 1, characterized in that: A delay adjustment window is added to the speed control program of the spinning machine and the pinch roller, and the adjustment range of the delay adjustment window is 0-1000 milliseconds.

3. A method for controlling the coil shape of a large-sized wire tail according to claim 1, characterized in that: In the step S1, a 1# hot metal detector is installed at the outlet of the sizing mill to detect the time when the tail of the rolled piece leaves the sizing mill. When the tail of the rolled piece leaves the sizing mill, the pinch rollers start to increase speed according to the set speed increase slope and maximum speed value. After the pinch rollers start to increase speed, the laying machine increases speed after the speed delay set in the delay adjustment window.

4. A method for controlling the coil shape of a large-sized wire tail according to claim 2, characterized in that: The speed delay setting of the delay adjustment window matches the coil shape spitted out by the spinning machine at the initial stage of the pinch roller speed increase.

5. A method for controlling the coil shape of a large-sized wire tail according to claim 1, characterized in that: In step S3, a 2# hot metal detector is installed 16-20 meters in front of the laying head. When the tail of the rolled piece runs to this position, the hot metal detector sends a signal. After a delay of the length set in the delay adjustment window, the air-cooled roller table is suspended, so that the tail coils spit out by the laying head are concentrated at one position of the roller table to avoid the formation of loose coils.

6. A method for controlling the coil shape of a large-sized wire tail according to claim 5, characterized in that: The length delay set in the delay adjustment window matches the number of coil turns that need to be concentrated.

7. A method for controlling the coil shape of a large-size wire tail according to claim 1, characterized in that: In step S4, a 3# hot metal detector is installed in front of the laying head to detect the tail position of the rolled piece.

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