Weak magnetic detection device for butt weld

Abstract

The utility model discloses a weak magnetic detection device for a butt weld, which belongs to the technical field of weak magnetic detection, and comprises five magnetic sensors, a positioning module, a bottom plate and a shell, the positioning module comprises a non-magnetic rotary encoder, a single wheel and a universal driving shaft, the single wheel is connected with the rotary encoder through the universal driving shaft, and the universal driving shaft is connected with the bottom plate. The bottom plate is provided with a welding seam channel matched with a butt welding seam in size to ensure that the probe moves horizontally in the welding seam direction, the movable connecting rod is connected with the positioning module through a bearing, the shell and the bottom plate are connected to form a closed structure, the magnetic sensors and the positioning module are contained in the shell, and the magnetic sensors are arranged in a double-layer array mode. Four magnetic sensors are arranged on the lower layer, and one magnetic sensor is arranged on the upper layer, so that the problems of inaccurate defect position positioning, unstable probe movement caused by weld reinforcement, susceptibility to interference of weak magnetic detection signals and the like when the existing weak magnetic detection equipment is used for detecting butt welds are solved.

Description

Technical Field

[0001] This utility model relates to the field of weak magnetic field detection technology, and in particular to a weak magnetic field detection device for butt welds. Background Technology

[0002] Non-destructive testing (NDT) is a non-destructive testing method that uses physical or chemical means and modern technology and equipment to inspect and test the internal and surface structure, properties, and state of a specimen. Weak magnetic field testing technology is based on the natural Earth's magnetic field. When a material has defects, its crystal or molecular structure changes, causing a change in the arrangement of electrons around the atomic nucleus, which in turn spontaneously generates a weak magnetic field. Weak magnetic field NDT technology uses a high-sensitivity magnetic sensor to detect magnetic anomalies caused by the combined effect of external magnetization and the spontaneous magnetic field of defects. It is a passive testing technology. In areas without defects on the workpiece surface, the detected magnetic field changes smoothly. In areas with defects on or near the surface, the magnetic induction intensity becomes abnormal. The original signal curve shows a smooth curve in areas without defects and a sharp peak in areas with defects.

[0003] Welding is a commonly used method for connection and sealing. Welds may contain defects such as pores and cracks, which can seriously endanger structural safety. Therefore, it is necessary to inspect the quality of welds regularly. Weak magnetic detection is an important weld inspection method that can effectively detect weld cracks and pore defects. However, current weak magnetic detection equipment has problems such as inaccurate defect location, unstable probe movement due to weld reinforcement, and susceptibility to interference when inspecting butt welds.

[0004] To address this, a weak magnetic field detection device for butt welds is proposed. Utility Model Content

[0005] The purpose of this invention is to provide a weak magnetic field detection device for butt welds, which can solve the problems of inaccurate defect location positioning, unstable probe movement due to weld reinforcement height, and easy interference of weak magnetic field detection signals in existing weak magnetic field detection equipment when detecting butt welds.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a weak magnetic detection device for butt welds, comprising five magnetic sensors, a positioning module, a base plate, and a housing. The positioning module includes a non-magnetic rotary encoder, a single wheel, and a linkage shaft. The single wheel is connected to the rotary encoder via the linkage shaft. The base plate is provided with a weld channel that matches the size of the butt weld to ensure that the probe moves horizontally along the weld direction. A movable connecting rod and a stainless steel spring are also included. The movable connecting rod is connected to the positioning module via a bearing. The housing is connected to the base plate to form a closed structure, and the magnetic sensors and the positioning module are housed inside.

[0007] Preferably, the magnetic sensor is arranged in a dual-layer array, with four magnetic sensors in the lower layer and one magnetic sensor in the upper layer. By differentially processing the detection signals of the lower and upper layers, jitter interference is eliminated and defect signals are retained.

[0008] Preferably, the non-magnetic rotary encoder is made of non-magnetic material, and the single wheel rotates synchronously with the rotary encoder through a linkage shaft.

[0009] Preferably, the weld channel of the base plate is designed according to the dimensions of the butt weld reinforcement height not exceeding 4mm and the reinforcement width not exceeding 20mm, to ensure that the probe does not come into contact with the weld when it moves.

[0010] Preferably, the movable connecting rod is fixed in the mounting hole of the base plate by the connecting rod fastening cap, and the compression of the stainless steel spring is adjustable, so that the lower edge of the single wheel is tangent to the lower surface of the base plate, maintaining the probe horizontally.

[0011] Preferably, the differential signal of the magnetic sensor is further processed by a self-differential algorithm to generate a self-differential curve, which is then combined with a preset threshold to identify defect signals and locate defect positions in real time.

[0012] Preferably, the outer shell and the base plate are connected by screws, and the outer shell integrates an aviation connector and a switch. The signal communicates with the host computer through the aviation connector cable. The overall structure is made of lightweight non-ferromagnetic material.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This application adds a positioning module and uses a combination of a rotary encoder and a single wheel to record the position of the magnetic sensor in real time, achieving accurate positioning of defect signals. The shape design takes into account the spatial characteristics of the butt weld, and the base plate has a reserved weld passage. During the inspection, the probe does not contact the weld, ensuring a stable inspection process. It can meet the inspection requirements of butt welds with a weld height of no more than 4mm and a weld width of no more than 20mm. The magnetic sensor adopts a double-layer differential design to effectively eliminate interference signals and improve detection accuracy. The device has a compact structure, small size, light weight, low cost, easy disassembly and assembly, easy portability, and simple operation. The materials used are non-ferromagnetic materials such as stainless steel and polymer materials to avoid interference with the detection signal. Attached Figure Description

[0015] Figure 1 This is an overall structural diagram of the weak magnetic field detection device for butt welds of this utility model;

[0016] Figure 2 This is a three-dimensional structural diagram of the internal structure of the shell in this utility model;

[0017] Figure 3 This is a graph showing the signal curve of the magnetic sensor in this invention.

[0018] Figure 4 This is a differential curve diagram of the magnetic sensor in this utility model;

[0019] Figure 5 This is a graph showing the signal curve of the magnetic sensor in this invention.

[0020] Figure 6 This is a differential curve diagram of the magnetic sensor in this utility model;

[0021] Figure 7 This is a diagram showing the self-differential curve of the magnetic sensor in this invention.

[0022] Figure 8 This is a bottom structural diagram of the present invention;

[0023] Figure 9 This is an overall cross-sectional view of the present invention.

[0024] In the diagram, 1. Magnetic sensor; 2. Positioning module; 201. Non-magnetic rotary encoder; 202. Single wheel; 203. Linkage shaft; 3. Base plate; 4. Bearing; 5. Stainless steel spring; 6. Movable connecting rod; 7. Connecting rod fastening cap; 8. Housing; 9. Switch; 10. Attachment connector. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figure 1-9 The present invention provides the following technical solution:

[0027] A weak magnetic detection device for butt welds includes five magnetic sensors 1, a positioning module 2, a base plate 3, and a housing 8. The positioning module 2 includes a non-magnetic rotary encoder 201, a single wheel 202, and a linkage shaft 203. The single wheel 202 is connected to the rotary encoder through the linkage shaft 203. The base plate 3 is provided with a weld channel that matches the size of the butt weld to ensure that the probe moves horizontally along the weld direction. There is also a movable link 6 and a stainless steel spring 5. The movable link 6 is connected to the positioning module 2 through a bearing 4. The housing 8 is connected to the base plate 3 to form a closed structure, and the magnetic sensors 1 and the positioning module 2 are housed inside.

[0028] In this embodiment: When the detection device is working, the single wheel 202 drives the non-magnetic rotary encoder 201 to rotate synchronously through the linkage shaft 203 during the detection movement. The rotary encoder records the rotation information in real time, thereby obtaining the position information of the probe. The weld channel on the base plate 3 matches the size of the butt weld, ensuring that the probe can move horizontally along the weld direction, so that the magnetic sensor 1 can stably detect the weld. The movable link 6 and the stainless steel spring 5 work together. During detection, the single wheel 202 contacts the workpiece being tested. When the single wheel 202 is subjected to pressure and rises, it drives the positioning module 2 to move through the movable link 6 and the bearing 4. The stainless steel spring 5 plays a role in buffering and maintaining stability, ensuring that the positioning module 2 and the magnetic sensor 1 work stably. The outer shell 8 and the base plate 3 form a closed structure to protect the internal magnetic sensor 1 and positioning module 2 and reduce external interference.

[0029] Specifically, such as Figure 2 As shown, the magnetic sensor 1 has a dual-layer array layout, with four magnetic sensors 1 in the lower layer and one magnetic sensor 1 in the upper layer. By differentially processing the detection signals of the lower and upper layers, jitter interference is eliminated and defect signals are retained.

[0030] In this embodiment: when the probe shakes during the detection process, the detection curves of the upper and lower layers of the magnetic sensor 1 in the dual-layer array layout will change synchronously. When passing through the weld defect, the lower layer magnetic sensor 1, which is closer to the detection surface, detects a stronger defect signal, while the upper layer magnetic sensor 1 detects a relatively weaker defect signal. By performing differential calculation on the data of the upper and lower layers of sensors, the interference signal caused by the probe shaking can be effectively removed, and the defect signal can be retained, thereby improving the detection accuracy and detecting weld defects more accurately.

[0031] Specifically, such as Figure 2 As shown, the non-magnetic rotary encoder 201 is made of non-magnetic material, and the single wheel 202 rotates synchronously with the rotary encoder through the linkage shaft 203.

[0032] In this embodiment: the non-magnetic rotary encoder 201 is made of non-magnetic material, which avoids interference with the weak magnetic detection signal. During the detection process, the single wheel 202 rolls as the detection device moves on the weld seam, and drives the rotary encoder to rotate synchronously through the linkage shaft 203. The rotary encoder converts the rotation of the single wheel 202 into an electrical signal, accurately records the position change of the probe, and provides accurate position information for the subsequent positioning of defect signals.

[0033] Specifically, such as Figure 2 As shown, the weld channel of the base plate 3 is designed according to the dimensions of the butt weld reinforcement height not exceeding 4mm and the reinforcement width not exceeding 20mm, to ensure that the probe does not come into contact with the weld when it moves.

[0034] In this embodiment, the weld channel of the base plate 3 is designed according to the dimensions of the butt weld reinforcement height not exceeding 4mm and the reinforcement width not exceeding 20mm. During the inspection, this size design ensures that the probe will not come into contact with the weld during the movement along the weld direction. This avoids the obstruction of probe movement caused by the unevenness of the weld surface, prevents the probe from tilting or shaking and affecting the inspection results, and ensures that the magnetic sensor 1 is always in a suitable inspection position directly above the weld, maintaining a stable inspection environment and improving the accuracy and stability of the inspection.

[0035] Specifically, such as Figure 2 As shown, the movable connecting rod 6 is fixed in the mounting hole of the base plate 3 by the connecting rod fastening cap 7, and the compression of the stainless steel spring 5 is adjustable, so that the lower edge of the single wheel 202 is tangent to the lower surface of the base plate 3, maintaining the probe horizontal.

[0036] In this embodiment, the movable link 6 is fixed in the mounting hole of the base plate 3 by the link fastening cap 7, which ensures the relative fixation of the position of the movable link 6 while allowing it to move within a certain range. The compression of the stainless steel spring 5 is adjustable. During detection, when the single wheel 202 contacts the workpiece being tested and is subjected to pressure, the stainless steel spring 5 is compressed, the movable link 6 rotates upward, and drives the single wheel 202 to rise. By adjusting the spring compression, the lower edge of the single wheel 202 is made tangent to the lower surface of the base plate 3, thereby maintaining the horizontal movement of the probe and ensuring the accuracy of the detection by the magnetic sensor 1.

[0037] Specifically, such as Figure 5 , Figure 6 and 7 As shown, the differential signal of magnetic sensor 1 is further processed by a self-differential algorithm to generate a self-differential curve, which is then combined with a preset threshold to identify defect signals and locate defect positions in real time.

[0038] In this embodiment: After differential de-jittering by two magnetic sensors, one in front and one behind, the two magnetic sensors are then differentially differentiated to obtain the differential signals of the two sensors. This differential signal is then self-differentialized. The processed differential signal is used to generate a self-differential curve by subtracting the data of the previous sampling point from the data of the next sampling point. In the defect-free area, the self-differential signal fluctuates slightly around 0 and is close to the horizontal axis. When passing through the weld defect, the self-differential signal will move away from the horizontal axis and fluctuate significantly. The self-differential curve is compared with a preset threshold. If the self-differential data exceeds the threshold, it is determined that a defect signal has been detected. Combined with the position information recorded by the rotary encoder, the defect location is accurately located.

[0039] Specifically, such as Figure 1 As shown, the outer shell 8 is connected to the base plate 3 by screws. The outer shell 8 integrates the aviation connector 10 and the switch 9. The signal communicates with the host computer through the aviation connector cable. The overall structure is made of lightweight non-ferromagnetic material.

[0040] In this embodiment, the outer shell 8 and the base plate 3 are connected by screws. This connection method facilitates the assembly and disassembly of the device. The internal components include a female connector 10 and a switch 9. The switch 9 is used to control signal acquisition. The excitation lines and signal lines of the magnetic sensor 1 and the non-magnetic rotary encoder 201 are connected to the female connector 10. The device communicates with the host computer through the female connector and transmits the detection data to the host computer for analysis and processing. The overall structure is made of lightweight non-ferromagnetic material, which reduces the weight of the device, making it easy to carry and operate. At the same time, it avoids interference from ferromagnetic materials on weak magnetic detection signals, ensuring the accuracy of the detection results.

[0041] Working Principle: First, the inspector connects the outer shell 8 of the inspection device to the base plate 3 with screws to form a closed structure, encapsulating components such as the magnetic sensor 1 and the positioning module 2 inside to protect them from external interference. Simultaneously, the integrated female connector 10 inside the device is connected to the host computer via an aviation connector cable. Switch 9 is then turned on to complete the communication connection between the inspection device and the host computer, preparing for the inspection work. During inspection, the device is placed at the butt weld to be inspected, aligning the weld channel on the base plate 3, which matches the dimensions of the butt weld, with the weld channel designed to ensure the weld reinforcement height is no more than 4mm and the reinforcement width is no more than 20mm. This ensures that the probe does not contact the weld when moving along the weld direction, avoiding interference from uneven weld surfaces. The probe moves smoothly and horizontally. During the movement of the device, the single wheel 202 rolls on the workpiece surface, driving the non-magnetic rotary encoder 201 to rotate synchronously via the linkage shaft 203. Since the non-magnetic rotary encoder 201 is made of non-magnetic material, it will not interfere with the weak magnetic detection signal. It converts the rotation of the single wheel 202 into an electrical signal, recording the probe's position information in real time, providing basic data for subsequent defect location. The movable connecting rod 6 is connected to the positioning module 2 via the bearing 4 and fixed in the mounting hole of the base plate 3 by the connecting rod fastening cap 7. One end of the stainless steel spring 5 is connected to the movable connecting rod 6, and the other end is connected to the outer shell 8. When the single wheel 202 is subjected to pressure and rises, the movable connecting rod 6 rotates around the bearing 4, and the stainless steel spring 5... The compression of the stainless steel spring 5 allows the lower edge of the single wheel 202 to be tangent to the lower surface of the base plate 3, maintaining the probe's horizontal position during detection and ensuring accuracy. The magnetic sensor 1 uses a double-layer array layout, with four magnetic sensors 1 in the lower layer and one magnetic sensor 1 in the upper layer. During detection, if the probe shakes, the detection curves of the upper and lower layer sensors will change synchronously. When passing through a weld defect, the lower layer magnetic sensor 1, which is closer to the weld, detects a stronger defect signal, while the upper layer magnetic sensor 1 detects a relatively weaker signal. By performing differential calculations on the data collected by the upper and lower layer sensors, interference signals caused by non-defect factors such as probe shaking can be removed, retaining the true defect signal. The signal is further processed using a differential algorithm, which generates a differential curve by subtracting the data from the previous sampling point from the data from the next sampling point. In the defect-free area of ​​the weld, the differential signal fluctuates slightly around 0. When a defect is detected in the weld, the differential signal deviates significantly from 0. A threshold is preset in the host computer, and the generated differential curve is compared with this threshold. If the differential data exceeds the threshold, a defect signal is detected. Combined with the position information recorded by the non-magnetic rotary encoder 201, the location of the defect in the weld can be located in real time and accurately. The detection data is transmitted to the host computer via a cable, facilitating analysis and judgment by the inspection personnel, ultimately achieving efficient detection and location of defects in the butt weld.

[0042] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A weak magnetic field detection device for butt welds, comprising five magnetic sensors (1), a positioning module (2), a base plate (3), and a housing (8), characterized in that: The positioning module (2) includes a non-magnetic rotary encoder (201), a single wheel (202) and a linkage shaft (203). The single wheel (202) is connected to the rotary encoder through the linkage shaft (203). The base plate (3) is provided with a weld channel that matches the size of the butt weld to ensure that the probe moves horizontally along the weld direction. The movable link (6) and stainless steel spring (5) are also included. The movable link (6) is connected to the positioning module (2) through a bearing (4). The outer shell (8) is connected to the base plate (3) to form a closed structure, and the magnetic sensor (1) and the positioning module (2) are housed inside.

2. The weak magnetic field detection device for butt welds according to claim 1, characterized in that: The magnetic sensor (1) is a dual-layer array layout, with four magnetic sensors (1) in the lower layer and one magnetic sensor (1) in the upper layer. By differentially processing the detection signals of the lower and upper layers, jitter interference is eliminated and defect signals are retained.

3. The weak magnetic field detection device for butt welds according to claim 1, characterized in that: The non-magnetic rotary encoder (201) is made of non-magnetic material, and the single wheel (202) rotates synchronously with the rotary encoder through the linkage shaft (203).

4. The weak magnetic field detection device for butt welds according to claim 1, characterized in that: The weld channel of the base plate (3) is designed according to the dimensions of the butt weld reinforcement height not exceeding 4mm and the reinforcement width not exceeding 20mm, to ensure that the probe does not come into contact with the weld when it moves.

5. The weak magnetic field detection device for butt welds according to claim 1, characterized in that: The movable connecting rod (6) is fixed in the mounting hole of the base plate (3) by the connecting rod fastening cap (7), and the compression of the stainless steel spring (5) is adjustable, so that the lower edge of the single wheel (202) is tangent to the lower surface of the base plate (3) to maintain the probe horizontal.

6. The weak magnetic field detection device for butt welds according to claim 2, characterized in that: The differential signal of the magnetic sensor (1) is further processed by the self-differential algorithm to generate a self-differential curve, and combined with a preset threshold to identify the defect signal and locate the defect position in real time.

7. The weak magnetic field detection device for butt welds according to claim 1, characterized in that: The outer shell (8) is connected to the base plate (3) by screws. The outer shell (8) integrates an aviation connector (10) and a switch (9). The signal communicates with the host computer through the aviation connector. The overall structure is made of lightweight non-ferromagnetic material.

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