Acoustic emission device for monitoring defects of cold-rolled sheet on line and use method of acoustic emission device

Abstract

The invention discloses an acoustic emission device for monitoring defects of a cold-rolled sheet on line and a use method thereof, and relates to a device for monitoring defects of a cold-rolled sheet on line and a use method thereof. The invention aims to solve the technical problem that online real-time monitoring cannot be carried out in the current sheet cold rolling process. Through acquisition of signals of the acoustic emission piezoelectric sensor and real-time analysis of the controller, the positions and types of the defects of the cold-rolled sheet can be accurately positioned and recognized, nondestructive testing is achieved, the displacement speed of the acoustic emission piezoelectric sensor is required to be the same as that of the sheet, missing acquisition of defect signals in part of the rolling process can be avoided, and the detection accuracy is improved. And online monitoring of the whole cold rolling process can be realized. The controller can control the motor and the roller to stop cold rolling after defects are recognized, so that defective products and waste of further machining are avoided; the production efficiency can be improved, the application range is wide, the cold rolling process is monitored on line, and the product quality can be improved.

Description

Technical Field

[0001] The invention relates to a device for online monitoring of cold-rolled thin plate defects and a use method thereof. Background Art

[0002] Cold-rolled thin plates are widely used in aerospace, precision instruments, electronic equipment and other fields. Their high strength, high precision and excellent surface quality make them ideal materials for the production of key components such as aircraft fuselages, spacecraft shells, precision electronic components and high-performance structural parts. The thin plate cold rolling process is achieved by using roller pressure to cause permanent deformation of the metal at room temperature. It usually includes multiple rolling processes to gradually reduce the thickness of the plate, improve its mechanical properties and surface quality, and achieve precise control of the plate thickness, excellent surface finish and uniform organizational structure, thereby meeting the strict requirements of the high-end manufacturing field. In addition, this process can also be combined with multi-layer composite and diffusion bonding technology to manufacture multi-layer composite structural parts, which has broad application and development prospects.

[0003] However, there are still some problems in the production process and quality control of the sheet cold rolling forming process, one of the main problems is the uncontrollability of the cold rolling process. The traditional sheet cold rolling process monitoring method, due to the process characteristics of the sheet continuously feeding into the roll during the cold rolling process, often uses speed sensors and vibration sensors, etc. The monitoring target is generally the output shaft of the cold rolling mill or the working roll of the cold rolling mill, but this forming process data collection and indirect monitoring method based on cold rolling equipment has the following problems: it is impossible to directly identify defects such as pitting, inclusions, penetration cracks, edge cracks, tensile cracks and discontinuous points and lines that appear in the sheet forming process; the small geometric defects that appear in the sheet deformation process have a very weak effect on the data collected by the speed or vibration sensor, and the quality of the cold rolled sheet still depends on the subsequent non-destructive testing for evaluation; the monitoring method that does not directly act on the cold rolled sheet is greatly affected by external factors, and the monitoring priority for the stable operation of the cold rolling equipment is higher than the appearance and evolution of sheet defects. For example, the abnormal source of vibration data may come from roll imbalance, bearing damage, roll damage, mechanical looseness, etc., thereby covering up the key information of the cold rolled sheet defects.

[0004] In summary, the existing thin plate cold rolling monitoring methods still have certain limitations. Therefore, developing a method that can monitor the plastic deformation process of thin plates in real time during cold rolling, and overcome the many deficiencies in the existing technology, so that the data collection sensor device directly acts on the thin plate material itself, and realizes the real-time evaluation of the overall quality of the thin plate and the online identification of defects and the analysis of their causes, has become an urgent problem to be solved in the industrial application of this field. Summary of the invention

[0005] The present invention aims to solve the technical problem that the current cold rolling process of thin plates cannot be monitored online in real time, and provides an acoustic emission device for online monitoring of defects of cold rolled thin plates and a method for using the device.

[0006] The acoustic emission device for online monitoring of cold-rolled sheet defects of the present invention is composed of a rolling roller 1, a rolling mill frame 2, an acoustic emission piezoelectric sensor 3, a controller 4, a preamplifier 5, a transmission belt 6, a displacement sensor 7, a motor 8, a support roller 10, a housing 12, a driving roller 13 and a driven roller 14; the above components are all existing equipment on the market;

[0007] A support roller 10 and a rolling roller 1 are arranged at the upper part of the inner cavity of the rolling mill frame 2, and the rolling roller 1 is located below the support roller 10 and the two are in a rolling connection relationship; the lower part and the upper part of the inner cavity of the rolling mill frame 2 are symmetrical structures, and a support roller 10 and a rolling roller 1 are also arranged, and a gap is left between the two rolling rollers 1;

[0008] The shell 12 is fixed on the outer wall of the rolling mill frame 2, and the bottom of the shell 12 is an open structure. A horizontally placed conveyor belt 6 is arranged in the inner cavity of the shell 12, and a plurality of acoustic emission piezoelectric sensors 3 are evenly fixed on the outer wall of the conveyor belt 6. The sensing surface of the acoustic emission piezoelectric sensor 3 is arranged in a direction away from the conveyor belt 6, and the sensing surface of the acoustic emission piezoelectric sensor 3 located below the conveyor belt 6 is at the same height as the gap between the two rollers 1; a driving roller 13 and a driven roller 14 are respectively arranged at both ends of the conveyor belt 6, and the driving roller 13 and the driven roller 14 are both engaged with the conveyor belt 6, and one end of the driving roller 13 is connected to the power output end of the motor 8, and the motor 8 is arranged on the outer wall of the shell 12;

[0009] The displacement sensor 7 is arranged on the outer wall of the rolling mill frame 2 and is located on the same side of the rolling mill frame 2 as the housing 12. The sensing surface of the displacement sensor 7 is located below and the height of the sensing surface is higher than the gap between the two rollers 1.

[0010] The signal output end of the acoustic emission piezoelectric sensor 3 is connected to the preamplifier 5 and the signal input end of the controller 4 in sequence; the signal output end of the displacement sensor 7 is connected to the signal input end of the controller 4; the signal output end of the controller 4 is connected to the signal input end of the motor 8.

[0011] The rolling mill frame 2 of the present invention contains existing structures required for cold rolling. Some structures are not mentioned in the text and are not the inventive points of the present invention, so they will not be introduced in more detail.

[0012] The use method and working principle of the acoustic emission device for online monitoring of cold-rolled sheet defects of the present invention are as follows:

[0013] The rolled metal sheet 9 is cut to a suitable size, and then the sheet 9 is placed between two rollers 1, and the sensing surface of the acoustic emission piezoelectric sensor 3 located below the conveyor belt 6 is attached to the upper surface of the sheet 9, and a gap is left between the sensing surface of the displacement sensor 7 and the upper surface of the sheet 9; then the roller 1 is started to start cold rolling the sheet 10, and at the same time, the motor 8 is started through the controller 4 to rotate the active roller 13 to drive the conveyor belt 6 to work, and the acoustic emission piezoelectric sensor 3 starts to move along the conveyor belt 6, and the displacement speed and displacement direction of the acoustic emission piezoelectric sensor 3 are the same as those of the sheet 9;

[0014] The plastic deformation signal generated in the cold rolling stage is transmitted to the preamplifier 5 through multiple acoustic emission piezoelectric sensors 3, and then received by the controller 4; the displacement sensor 7 also transmits the displacement of the plate 9 to the controller 4; after receiving various signals, the controller 4 performs signal processing, analysis and regulation, and when a defect is identified through the linear displacement rate algorithm and the signal defect recognition algorithm, the cold rolling is stopped or the defect is accurately located by controlling the motor 8 and the roller 1; at the end of the cold rolling, the roller 1 is turned off first, then the displacement sensor 7 and the acoustic emission piezoelectric sensor 3 are turned off, and finally the controller 4 is turned off to take out the cold-rolled plate 9.

[0015] The present invention adopts the above-mentioned acoustic emission device for online monitoring of defects in cold-rolled thin plates and its use method. Through the collection of signals from the acoustic emission piezoelectric sensor 3 and real-time analysis by the controller 4, the position and type of defects in the cold-rolled thin plates can be accurately located and identified to achieve non-destructive testing. It requires that the displacement speed of the acoustic emission piezoelectric sensor 3 is the same as the displacement speed of the plate 9, which can avoid missing defect signals in part of the rolling process and achieve online monitoring of the entire cold rolling process.

[0016] The present invention has the following beneficial effects:

[0017] 1. The present invention can accurately locate and identify the position and type of defects in the cold-rolled sheet process by collecting and analyzing the signals of the acoustic emission piezoelectric sensor 3, thereby realizing non-destructive monitoring in the cold-rolling process;

[0018] 2. The present invention receives and processes signals in real time through the controller 4, can monitor the position of defects in real time, and can distinguish the types of defects to achieve high-precision online monitoring, and provide early warning of defects in the cold rolling process;

[0019] 3. The present invention can control the motor 8 and the roller 1 to stop cold rolling after identifying defects through the controller 4 to avoid the production of defective products and waste of further processing;

[0020] 4. The present invention can improve production efficiency, has a wide range of applications, and can monitor the cold rolling process online, which is beneficial to improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of an acoustic emission device for online monitoring of defects of cold-rolled thin plates according to a specific implementation mode 1;

[0022] Figure 2 It is a schematic plan view of an acoustic emission device for online monitoring of defects of cold-rolled thin plates according to a first specific implementation mode;

[0023] Figure 3 for Figure 1 A partial enlarged schematic diagram of . DETAILED DESCRIPTION

[0024] Specific implementation method 1: This implementation method is an acoustic emission device for online monitoring of defects in cold-rolled thin plates, such as Figure 1-Figure 3 As shown, it is specifically composed of a rolling roller 1, a rolling mill frame 2, an acoustic emission piezoelectric sensor 3, a controller 4, a preamplifier 5, a transmission belt 6, a displacement sensor 7, a motor 8, a support roller 10, a housing 12, a driving roller 13 and a driven roller 14;

[0025] A support roller 10 and a rolling roller 1 are arranged at the upper part of the inner cavity of the rolling mill frame 2, and the rolling roller 1 is located below the support roller 10 and the two are in a rolling connection relationship; the lower part and the upper part of the inner cavity of the rolling mill frame 2 are symmetrical structures, and a support roller 10 and a rolling roller 1 are also arranged, and a gap is left between the two rolling rollers 1;

[0026] The shell 12 is fixed on the outer wall of the rolling mill frame 2, and the bottom of the shell 12 is an open structure. A horizontally placed conveyor belt 6 is arranged in the inner cavity of the shell 12, and a plurality of acoustic emission piezoelectric sensors 3 are evenly fixed on the outer wall of the conveyor belt 6. The sensing surface of the acoustic emission piezoelectric sensor 3 is arranged in a direction away from the conveyor belt 6, and the sensing surface of the acoustic emission piezoelectric sensor 3 located below the conveyor belt 6 is at the same height as the gap between the two rollers 1; a driving roller 13 and a driven roller 14 are respectively arranged at both ends of the conveyor belt 6, and the driving roller 13 and the driven roller 14 are both engaged with the conveyor belt 6, and one end of the driving roller 13 is connected to the power output end of the motor 8, and the motor 8 is arranged on the outer wall of the shell 12;

[0027] The displacement sensor 7 is arranged on the outer wall of the rolling mill frame 2 and is located on the same side of the rolling mill frame 2 as the housing 12. The sensing surface of the displacement sensor 7 is located below and the height of the sensing surface is higher than the gap between the two rollers 1.

[0028] The signal output end of the acoustic emission piezoelectric sensor 3 is connected to the preamplifier 5 and the signal input end of the controller 4 in sequence; the signal output end of the displacement sensor 7 is connected to the signal input end of the controller 4; the signal output end of the controller 4 is connected to the signal input end of the motor 8.

[0029] Specific implementation method 2: This implementation method is different from the specific implementation method 1 in that the motor 8 is a servo motor. The rest is the same as the specific implementation method 1.

[0030] Specific embodiment 3: This embodiment is different from specific embodiment 1 or 2 in that the roller 1 is driven by a servo motor, and the signal input end of the servo motor is connected to the signal output end of the controller 4. Other aspects are the same as specific embodiment 1 or 2.

[0031] Specific embodiment 4: This embodiment is different from specific embodiments 1 to 3 in that the controller 4, preamplifier 5, displacement sensor 7 and housing 12 are all fixed to the outer wall of the rolling mill frame 2 through a bracket 11. The rest is the same as specific embodiments 1 to 3.

[0032] Specific embodiment 5: This embodiment is different from specific embodiment 4 in that one end of the driven roller 14 is disposed on the side wall of the housing 12 and is in a sliding relationship with the side wall of the housing 12. The rest is the same as specific embodiment 4.

[0033] Specific implementation example 6: This implementation example is different from specific implementation example 5 in that: the controller 4 includes an instruction receiving unit and a signal processing and analysis unit; the instruction receiving unit has a built-in linear displacement rate algorithm, and the signal analysis unit has a built-in defect recognition algorithm. Other aspects are the same as specific implementation example 5.

[0034] Specific implementation example 7: This implementation example is different from specific implementation example 6 in that the displacement sensor 7 is an infrared displacement sensor. The rest is the same as specific implementation example 6.

[0035] Specific implementation eight: This implementation is a method for using the acoustic emission device for online monitoring of cold-rolled sheet defects in specific implementation one, and the specific process is as follows:

[0036] The rolled metal sheet 9 is cut to a suitable size, and then the sheet 9 is placed between two rollers 1, and the sensing surface of the acoustic emission piezoelectric sensor 3 located below the conveyor belt 6 is attached to the upper surface of the sheet 9, and a gap is left between the sensing surface of the displacement sensor 7 and the upper surface of the sheet 9; then the roller 1 is started to start cold rolling the sheet 10, and at the same time, the motor 8 is started through the controller 4 to rotate the active roller 13 to drive the conveyor belt 6 to work, and the acoustic emission piezoelectric sensor 3 starts to move along the conveyor belt 6, and the displacement speed and displacement direction of the acoustic emission piezoelectric sensor 3 are the same as those of the sheet 9;

[0037] The plastic deformation signal generated in the cold rolling stage is transmitted to the preamplifier 5 through multiple acoustic emission piezoelectric sensors 3, and then received by the controller 4; the displacement sensor 7 also transmits the displacement of the plate 9 to the controller 4; after receiving various signals, the controller 4 performs signal processing, analysis and regulation, and when a defect is identified through the linear displacement rate algorithm and the signal defect recognition algorithm, the cold rolling is stopped or the defect is accurately located by controlling the motor 8 and the roller 1; at the end of the cold rolling, the roller 1 is turned off first, then the displacement sensor 7 and the acoustic emission piezoelectric sensor 3 are turned off, and finally the controller 4 is turned off to take out the cold-rolled plate 9.

[0038] This embodiment adopts the above-mentioned acoustic emission device for online monitoring of defects in cold-rolled thin plates and its use method. Through the acquisition of the signal of the acoustic emission piezoelectric sensor 3 and the real-time analysis of the controller 4, the position and type of defects in the cold-rolled thin plates can be accurately located and identified to achieve non-destructive testing. It requires that the displacement speed of the acoustic emission piezoelectric sensor 3 is the same as the displacement speed of the plate 9, which can avoid the omission of defect signals in part of the rolling process and realize online monitoring of the entire cold rolling process.

[0039] This embodiment has the following beneficial effects:

[0040] 1. This embodiment can accurately locate and identify the position and type of defects in the cold-rolled sheet process through the collection and analysis of the acoustic emission piezoelectric sensor 3 signal, thereby realizing non-destructive monitoring of the cold-rolling process;

[0041] 2. This embodiment can monitor the position of defects in real time and distinguish the types of defects by receiving and processing signals in real time through the controller 4, so as to realize high-precision online monitoring and provide early warning for defects in the cold rolling process;

[0042] 3. In this embodiment, the controller 4 can control the motor 8 and the roller 1 to stop cold rolling after identifying the defect to avoid the production of defective products and waste of further processing;

[0043] 4. This implementation method can improve production efficiency, has a wide range of applications, and can monitor the cold rolling process online, which is beneficial to improving product quality.

Claims

1. An acoustic emission device for online monitoring of cold-rolled sheet defects, characterized in that The acoustic emission device for online monitoring of cold-rolled sheet defects is composed of a rolling roller (1), a rolling mill frame (2), an acoustic emission piezoelectric sensor (3), a controller (4), a preamplifier (5), a transmission belt (6), a displacement sensor (7), a motor (8), a support roller (10), a housing (12), a driving roller (13) and a driven roller (14); A support roller (10) and a rolling roller (1) are arranged at the upper part of the inner cavity of the rolling mill frame (2), and the rolling roller (1) is located below the support roller (10) and the two are in a rolling connection relationship; the lower part and the upper part of the inner cavity of the rolling mill frame (2) are symmetrical structures, and are also provided with a support roller (10) and a rolling roller (1), and a gap is left between the two rolling rollers (1); The shell (12) is fixed on the outer wall of the rolling mill frame (2), the bottom of the shell (12) is an open structure, a horizontally placed transfer belt (6) is arranged in the inner cavity of the shell (12), a plurality of acoustic emission piezoelectric sensors (3) are evenly fixed on the outer wall of the transfer belt (6), the sensing surface of the acoustic emission piezoelectric sensor (3) is arranged in a direction away from the transfer belt (6), and the sensing surface of the acoustic emission piezoelectric sensor (3) located below the transfer belt (6) is at the same height as the gap between the two rollers (1); a driving roller (13) and a driven roller (14) are respectively arranged at the two ends of the transfer belt (6), the driving roller (13) and the driven roller (14) are both engaged with the transfer belt (6), one end of the driving roller (13) is connected to the power output end of the motor (8), and the motor (8) is arranged on the outer wall of the shell (12); The displacement sensor (7) is arranged on the outer wall of the rolling mill frame (2) and is located on the same side of the rolling mill frame (2) as the outer shell (12); the sensing surface of the displacement sensor (7) is located at the bottom and the height of the sensing surface is higher than the gap between the two rollers (1); The signal output end of the acoustic emission piezoelectric sensor (3) is connected to the preamplifier (5) and the signal input end of the controller (4) in sequence; the signal output end of the displacement sensor (7) is connected to the signal input end of the controller (4); and the signal output end of the controller (4) is connected to the signal input end of the motor (8).

2. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1 is characterized in that The motor (8) is a servo motor.

3. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1 is characterized in that The roller (1) is driven by a servo motor, and the signal input end of the servo motor is connected to the signal output end of the controller (4).

4. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1 is characterized in that The controller (4), preamplifier (5), displacement sensor (7) and housing (12) are all fixed on the outer wall of the rolling mill frame (2) via a bracket (11).

5. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1, characterized in that One end of the driven roller (14) is arranged on the side wall of the housing (12) and is in a sliding relationship with the side wall of the housing (12).

6. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1, characterized in that The controller (4) comprises an instruction receiving unit and a signal processing and analysis unit; the instruction receiving unit has a built-in linear displacement rate algorithm, and the signal analysis unit has a built-in defect recognition algorithm.

7. The acoustic emission device for online monitoring of cold-rolled sheet defects according to claim 1 is characterized in that The displacement sensor (7) is an infrared displacement sensor.

8. The method for using the acoustic emission device for online monitoring of cold-rolled sheet defects as claimed in claim 1, characterized in that The method of using the acoustic emission device for online monitoring of cold-rolled sheet defects is as follows: The rolled metal plate (9) is cut into a suitable size, and then the plate (9) is placed between two rollers (1), and the sensing surface of the acoustic emission piezoelectric sensor (3) located below the conveyor belt (6) is attached to the upper surface of the plate (9), and a gap is left between the sensing surface of the displacement sensor (7) and the upper surface of the plate (9); then the rollers (1) are started to start cold rolling the plate (10), and at the same time, the motor (8) is started through the controller (4) to rotate the active roller (13) to drive the conveyor belt (6), and the acoustic emission piezoelectric sensor (3) starts to move along the conveyor belt (6), and the displacement speed and displacement direction of the acoustic emission piezoelectric sensor (3) are the same as those of the plate (9); The plastic deformation signal generated in the cold rolling stage is transmitted to the preamplifier (5) through multiple acoustic emission piezoelectric sensors (3), and then received by the controller (4); the displacement sensor (7) also transmits the displacement of the plate (9) to the controller (4); the controller (4) performs signal processing analysis and regulation after receiving various signals, and when a defect is identified through a linear displacement rate algorithm and a signal defect recognition algorithm, the cold rolling is stopped or the defect is accurately located by controlling the motor (8) and the roller (1); at the end of the cold rolling, the roller (1) is first turned off, then the displacement sensor (7) and the acoustic emission piezoelectric sensor (3) are turned off, and finally the controller (4) is turned off to take out the cold rolled plate (9).

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