A method for preventing strip edge running

Abstract

The present application relates to a method for preventing strip edge running, which checks raw material before entering the machine to prevent edge running accidents caused by edge defects of the raw material; detects edge defects of the raw material strip before edge cutting through the setting of a grating detection device to discover and take speed reduction and early warning measures in advance, ensure timely discovery and treatment of edge running accidents, shorten downtime caused by edge running accidents and improve production efficiency; and ensures stable running state of the strip before edge cutting through the setting of a press roller to avoid edge running accidents caused by strip jumping during edge cutting.

Description

Technical Field

[0001] This invention relates to the field of cold-rolled strip steel production technology, and in particular to a method for preventing strip steel from running off the edges. Background Technology

[0002] Cold-rolled strip steel is an important type of steel, widely used in industries such as automobiles, shipbuilding, aerospace, and machinery. Cold-rolled strip steel uses hot-rolled plates as raw material, and its production process includes pickling and rolling, continuous annealing, hot-dip galvanizing, coating, leveling, cross-cutting, slitting, and rewinding. The pickling and rolling, continuous annealing, cross-cutting, and rewinding processes all include edge trimming.

[0003] The purpose of strip trimming is to give the cold-rolled intermediate products a predetermined size to facilitate subsequent production, ensuring that the cold-rolled products are dimensionally accurate, neat, and aesthetically pleasing. For example... Figure 1 , Figure 2 As shown, under normal circumstances, the waste edges cut off by the edge trimming shear 2 on the strip steel 1 are fed into the edge breaking shear 4 via waste edge chutes 3 set on both sides of the strip steel production line. The edge breaking shear 4 cuts the waste edges into fragments of about 20cm in length and collects them into the waste edge hopper 5. In actual production, due to defects such as edge gaps and cambers in the raw materials, as well as vibrations during edge cutting by the edge breaking shear, the cut waste edges often cannot be smoothly fed into the waste edge chute, causing edge slippage accidents. After an edge slippage accident occurs, the machine needs to be stopped and manually handled by the operator. The downtime for handling this is relatively long, affecting strip steel production and posing safety hazards. Summary of the Invention

[0004] This invention provides a method to prevent strip steel from running off the edge. By taking measures such as raw material inspection, grating detection and early warning, and setting pressure rollers, the method can effectively prevent strip steel from running off the edge, ensure the smooth operation of the cold rolling production line, and improve production efficiency.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] 1. A method for preventing strip steel from running off-edge, comprising the following steps:

[0007] 1) Before the steel coil is loaded onto the machine, manually inspect the two sides of the steel coil. Raw steel coils with cracks or edge gaps will not be loaded onto the machine.

[0008] 2) Before the steel coil is loaded onto the machine, manually check whether the outer ring and the core of the steel coil are misaligned. If there is misalignment, it means that there is a sickle bend at the head and tail of the strip. For raw steel coils with misaligned outer rings, increase the number of cuts when cutting the head at the preparation station to remove the sickle bend at the head. For raw steel coils with misaligned cores, increase the number of cuts at the tail before welding them to the next steel coil to remove the sickle bend at the tail.

[0009] 3) After the steel coil is cut at the preparation station, measure the strip width to ensure that the width of the raw strip is 20-30mm wider than the strip width after cutting.

[0010] 4) Along the strip's moving direction, a grating detection device is installed 4-6m upstream of the edge-cutting shear. The grating detection device has grating probes positioned above each of the corresponding two sides of the strip to detect any notches or camber defects. The spacing between the two grating probes is automatically adjusted according to the strip width. When a defect is detected, the grating detection device sends a signal to the computer control system in the main control room, displaying an audible and visual alarm on the main control interface. Simultaneously, the computer control system sends a signal to the strip transmission system, automatically reducing the strip's speed as it passes through the edge-cutting shear. Upon receiving the alarm, operators closely monitor the strip's edge-cutting status and immediately stop the strip if any edge slippage is detected. After the defective section of the strip passes through the edge-cutting shear, the strip switches back to normal production speed.

[0011] 5) Along the direction of strip movement, a pressure roller device is installed 0.8 to 1.2m downstream of the edge cutting shear. The pressure roller device consists of a pressure roller and a cylinder. The roller shafts at both ends of the pressure roller are connected to the corresponding cylinders. During edge cutting, the cylinder drives the pressure roller to move down and press the strip tight to prevent edge running accidents caused by the vibration of the edge cutting shear. When not cutting the edge, the pressure roller does not contact the strip.

[0012] 6) Automatic control is achieved through the weld seam tracking system of the cold rolling mill. When the weld seam between the previous and next steel coils reaches a position 4 to 6 meters upstream of the edge trimmer, the strip steel automatically slows down to prevent edge slippage accidents when the weld seam passes through the edge trimmer at high speed.

[0013] Furthermore, the grating detection device consists of a grating frame, a grating probe, and a probe moving mechanism; the grating frame is located above the strip moving path, the grating probe is installed at the bottom of the grating frame, and the probe moving mechanism is a screw drive mechanism used to drive the grating probe to move longitudinally relative to or opposite to each other along the grating frame; the control end of the probe moving mechanism is connected to the computer control system in the main control room.

[0014] Furthermore, the bottom surface of the grating probe is 200-240 mm higher than the upper surface of the strip steel.

[0015] Furthermore, a rubber lining is provided on the outer side of the pressure roller; the control end of the cylinder is connected to the computer control system in the main control room.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1) Inspect the raw materials before loading them onto the machine to prevent edge defects from causing edge running accidents;

[0018] 2) Install a grating detection device to detect edge defects of the raw strip steel before trimming, so as to detect them in advance and take measures such as speed reduction and early warning, ensure timely detection and handling of edge running accidents, shorten downtime caused by edge running accidents, and improve production efficiency.

[0019] 3) Set pressure rollers to ensure stable operation of the strip before edge trimming and avoid edge running accidents caused by strip jumping during edge trimming. Attached Figure Description

[0020] Figure 1 This is a top view of the strip cut edge described in this invention.

[0021] Figure 2 yes Figure 1 Front view.

[0022] Figure 3 This is a schematic diagram of the setting state of the grating detection device described in this invention.

[0023] Figure 4 yes Figure 3 Side view.

[0024] Figure 5 This is a schematic diagram of the pressure roller setting state according to the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the pressure roller described in this invention.

[0026] In the diagram: 1. Strip steel 2. Trimming shear 3. Scrap edge chute 4. Edge breaking shear 5. Scrap edge hopper 6. Grating frame 7. Grating probe 8. Strip steel conveyor roller 9. Pressure roller 10. Cylinder Detailed Implementation

[0027] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0028] The method for preventing strip steel from running off-edge according to the present invention includes the following process:

[0029] 1) Before the steel coil is loaded onto the machine, manually inspect the two sides of the steel coil. Raw steel coils with cracks or edge gaps will not be loaded onto the machine.

[0030] 2) Before the steel coil is loaded onto the machine, manually check whether the outer ring and the core of the steel coil are misaligned. If there is misalignment, it means that there is a sickle bend at the head and tail of the strip. For raw steel coils with misaligned outer rings, increase the number of cuts when cutting the head at the preparation station to remove the sickle bend at the head. For raw steel coils with misaligned cores, increase the number of cuts at the tail before welding them to the next steel coil to remove the sickle bend at the tail.

[0031] 3) After the steel coil is cut at the preparation station, measure the strip width to ensure that the width of the raw strip is 20-30mm wider than the strip width after cutting.

[0032] 4) Install a grating detection device 4-6m upstream of the shear along the strip movement direction, such as... Figure 3 , Figure 4 As shown, the grating detection device has grating probes 7 installed above the two sides of the corresponding strip 1 to detect whether there are gaps or camber defects on both sides of the strip 1. The spacing between the two grating probes 7 can be automatically adjusted according to the width of the strip 1. When a defect is detected, the grating detection device sends a signal to the computer control system in the main control room. At the same time, an audible and visual alarm is displayed on the main control interface. Simultaneously, the computer control system sends a signal to the strip transmission system to automatically reduce the running speed of the strip when passing through the edge trimmer. After receiving the alarm, the operator closely monitors the edge trimming status of the strip. If edge slippage is detected, the strip operation is stopped immediately. After the defective part of the strip passes through the edge trimmer, the strip switches back to normal production speed.

[0033] 5) Install a pressure roller device 0.8–1.2 m downstream of the shear along the strip's movement direction, such as... Figure 5 , Figure 6 As shown, the pressure roller device consists of a pressure roller 9 and a cylinder 10. The roller shafts at both ends of the pressure roller 9 are connected to the corresponding cylinders 10. When cutting the edge, the cylinder 10 drives the pressure roller 9 to move down and press the strip 1 tightly to prevent the strip from jumping due to the vibration of the edge shear and causing the edge to run away. When not cutting the edge, the pressure roller does not contact the strip.

[0034] 6) Automatic control is achieved through the weld seam tracking system of the cold rolling mill. When the weld seam between the previous and next steel coils reaches a position 4 to 6 meters upstream of the edge trimmer, the strip steel automatically slows down to prevent edge slippage accidents when the weld seam passes through the edge trimmer at high speed.

[0035] Furthermore, the grating detection device consists of a grating frame, a grating probe, and a probe moving mechanism; the grating frame is located above the strip moving path, the grating probe is installed at the bottom of the grating frame, and the probe moving mechanism is a screw drive mechanism used to drive the grating probe to move longitudinally relative to or opposite to each other along the grating frame; the control end of the probe moving mechanism is connected to the computer control system in the main control room.

[0036] Furthermore, the bottom surface of the grating probe is 200-240 mm higher than the upper surface of the strip steel.

[0037] Furthermore, a rubber lining is provided on the outer side of the pressure roller; the control end of the cylinder is connected to the computer control system in the main control room.

[0038] The following embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0039]

Example

[0040] In this embodiment, the following technical measures are adopted to prevent the strip from running off the edge:

[0041] I. The cold rolling mill strictly controls the raw materials.

[0042] 1. Before loading the steel coil onto the machine, carefully inspect both sides of the steel coil. Raw materials with cracks or gaps on the edges should not be loaded onto the machine.

[0043] 2. Before loading the steel coils onto the machine, check if the outer ring and core of the coils are misaligned. If misalignment is found, it indicates that there is a camber at the beginning and end of the strip. For raw steel coils with misaligned outer rings, increase the number of cuts during the head-cutting process at the preparation station to ensure the removal of the camber at the strip head. For raw steel coils with misaligned cores, increase the number of cuts at the tail before welding them to the next coil to ensure the removal of the camber at the strip tail.

[0044] 3. After the steel coil is cut at the preparation station, the strip width is measured with a tape measure to ensure that the incoming material width is 20mm greater than the cut edge width. In this embodiment, the production plan requires the steel plate width after cutting to be 1254mm, so the incoming material width cannot be less than 1274mm.

[0045] II. Grating detection.

[0046] In the cold rolling mill, the strip steel is conveyed by strip steel conveying roller 8. In this embodiment, a grating detection device is installed 6m upstream of the edge trimming shear to detect notches and camber defects on both sides of the strip steel. In this embodiment, the bottom surface of the two grating probes is 220mm higher than the upper surface of the strip steel, and the two grating probes are respectively positioned directly above the two sides of the strip steel.

[0047] The two grating probes can automatically adjust their spacing according to the set trimming width. In this embodiment, the raw material width is 1274mm; the width of the strip after trimming is set to 1254mm, so the distance between the two grating probes is automatically adjusted to 1252mm.

[0048] In this embodiment, there is a notch larger than 2mm on the left side of the strip. When the strip segment with the notch runs under the grating probe, it is detected by the grating probe on the left and the signal is transmitted to the computer control system in the main control room. At the same time, an audible and visual alarm is displayed on the operation interface. Simultaneously, the computer control system sends a signal to the strip transmission system, and the transmission system automatically reduces the running speed of the strip when passing through the edge shear.

[0049] Upon receiving the alarm, operators closely monitor the strip edge cutting status. If edge slippage is detected, strip operation can be stopped immediately and the issue addressed promptly. This avoids edge slippage accidents caused by edge defects during high-speed strip operation and significantly reduces the time required to handle such incidents. In this embodiment, strip speed was reduced using edge cutting shears, and no edge slippage accident occurred.

[0050] After the strip with a notch is cut by the edge trimmer, the operator switches the strip running speed back to the original high-speed running state.

[0051] 3. Use pressure rollers to stabilize the strip steel.

[0052] In this embodiment, a pressure roller device is installed 1m downstream of the cutting edge shear. The pressure roller is 800mm long, has an outer diameter of 170mm, and has a 20mm thick rubber lining on its outer side.

[0053] When the strip is being trimmed, the cylinder drives the pressure roller to move down and press down on the upper surface of the strip, thus avoiding the strip running accident caused by the vibration of the shear.

[0054] When edge trimming is not required, the cylinder drives the pressure roller to lift, which does not hinder the normal operation of the strip.

[0055] IV. The weld seam automatically slows down when passing through the shear.

[0056] In the production of cold-rolled strip steel, at the front of the cold rolling mill, a large, high-speed welding machine welds the tail of the previous coil to the head of the next coil together to ensure the continuous operation of the cold rolling mill. This results in a weld seam between the two coils. Because the head and tail of the raw steel coils generally have problems such as width deviations and camber defects, the weld seam is easily damaged by edge slippage during edge trimming.

[0057] In this embodiment, the weld seam tracking system of the cold rolling mill automatically controls the strip speed to decrease when the weld seam is 5m away from the edge shear, so as to avoid the edge running accident when the weld seam passes through the edge shear at high speed.

[0058] After taking the above measures, the cold-rolled strip steel production line in this embodiment reduces the unit downtime caused by edge running accidents by more than 150 hours per year.

[0059] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preventing strip steel edge slippage, wherein the waste edge cut off by the strip steel by the edge trimming shear is guided into the edge cutting shear by waste edge chutes set on both sides of the strip steel production line; characterized in that, The process includes the following: 1) Before the steel coil is loaded onto the machine, the two sides of the steel coil are manually inspected. Raw steel coils with cracks or edge gaps are not loaded onto the machine. 2) Before the steel coil is loaded onto the machine, manually check whether the outer ring and the core of the steel coil are misaligned. If there is misalignment, it means that there is a sickle bend at the head and tail of the strip. For raw steel coils with misaligned outer rings, increase the number of cuts when cutting the head at the preparation station to remove the sickle bend at the head. For raw steel coils with misaligned cores, increase the number of cuts at the tail before welding them to the next steel coil to remove the sickle bend at the tail. 3) After the steel coil is cut at the preparation station, measure the strip width to ensure that the width of the raw strip is 20-30mm wider than the strip width after cutting. 4) A grating detection device is installed 4-6m upstream of the shear along the strip's movement direction. The grating detection device consists of a grating frame, a grating probe, and a probe moving mechanism. The grating frame is positioned above the strip's movement path, the grating probe is installed at the bottom of the grating frame, and the probe moving mechanism is a screw drive mechanism used to drive the grating probe to move longitudinally relative to or opposite to each other along the grating frame. The control end of the probe moving mechanism is connected to the computer control system in the main control room. The grating detection device has grating probes installed above the corresponding two sides of the strip, with the bottom surface of the grating probes 200-240mm higher than the upper surface of the strip. This device is used to detect notches and camber defects on both sides of the strip steel. The spacing between the two grating probes can be automatically adjusted according to the strip steel width. When a defect is detected, the grating detection device sends a signal to the computer control system in the main control room. At the same time, an audible and visual alarm is displayed on the main control interface. Simultaneously, the computer control system sends a signal to the strip steel transmission system to automatically reduce the running speed of the strip steel when passing through the edge trimmer. After receiving the alarm, the operator closely monitors the edge trimming status of the strip steel. If edge slippage is detected, the strip steel operation is immediately stopped. After the defective part of the strip steel passes through the edge trimmer, the strip steel switches back to normal production speed. 5) A pressure roller device is installed 0.8 to 1.2 m downstream of the edge-cutting shear along the strip's movement direction. The pressure roller device consists of a pressure roller and a cylinder. The roller shafts at both ends of the pressure roller are connected to the corresponding cylinders, and a rubber lining is provided on the outside of the pressure roller. The control end of the cylinder is connected to the computer control system in the main control room. During edge cutting, the cylinder drives the pressure roller to move down and press the strip tightly to prevent edge running accidents caused by the strip jumping due to the vibration of the edge-cutting shear. When not cutting the edge, the pressure roller does not contact the strip. 6) Automatic control is achieved through the weld seam tracking system of the cold rolling mill. When the weld seam between the previous and next steel coils reaches a position 4 to 6 meters upstream of the edge cutting shear, the strip steel automatically slows down to avoid edge running accidents when the weld seam passes through the edge cutting shear at high speed.

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