T-shaped joint automatic welding web positioning far-field eddy current probe and detection method thereof

Abstract

The invention provides a T-shaped joint automatic welding web positioning far-field eddy current probe, an excitation unit comprises an auxiliary shielding layer, a magnetism gathering bowl and an excitation coil, a receiving unit comprises a magnetic column, a balance resistor and a receiving coil, the upper end of a probe shell is provided with a signal I / O plug, and the main shielding layer, the auxiliary shielding layer, the magnetism gathering bowl and the excitation coil are sequentially sleeved along the periphery to form an integrated structure. The probe shell is provided with a cavity with an open lower end, the main shielding layer, the auxiliary shielding layer, the magnetism gathering bowl and the exciting coil are combined and arranged in the cavity, the receiving coil is sleeved on the outer side of the magnetic column, the lower end of the main shielding layer is provided with a blind hole, the receiving coil and the magnetic column are combined and arranged in the blind hole, and the balance resistor and the receiving coil are combined to form a bridge circuit structure. The balancing resistors form two bridge arms of the bridge, and the two receiving coils form the other two bridge arms of the bridge; precise positioning of the web plate in the H-shaped steel plate T-shaped joint welding process is achieved, and the technical problem of welding deviation in the H-shaped steel plate automatic welding process is solved.

Description

Technical Field

[0001] This invention relates to the field of T-joint web positioning technology, and in particular to a far-field eddy current probe for automatic welding web positioning of T-joints and its detection method. Background Technology

[0002] H-beams are widely used in modern industry due to their lightweight, high tensile strength, and excellent cross-sectional properties. The automated welding process for H-beams includes plate cutting, component assembly, web positioning, and plate welding. Currently, web positioning is done manually by marking the T-joints at both ends of the assembled component to form a straight line that represents the web's position. Welding is then performed along this marked line. However, due to tolerances in web straightness, weld misalignment occurs during welding. Therefore, a precise positioning method is needed to accurately position the web of the T-joints to improve the welding success rate of the T-joints. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a far-field eddy current probe and its detection method for automatic welding web positioning of T-joints, achieving precise web positioning during the welding of H-beam steel plate T-joints and solving the technical problem of weld misalignment during automatic welding of H-beam steel plates. To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A far-field eddy current probe for automatic welding web positioning using a T-type connector includes a probe housing, a main shielding layer, an excitation unit, and a receiving unit. The excitation unit includes a secondary shielding layer, a magnetic cup, and an excitation coil. The receiving unit includes a magnetic column, balancing resistors, and a receiving coil. The upper end of the probe housing has a signal I / O plug. The main shielding layer, secondary shielding layer, magnetic cup, and excitation coil are sequentially sleeved along the outer periphery to form an integral structure. The probe housing has a cavity with an open lower end. The main shielding layer, secondary shielding layer, magnetic cup, and excitation coil are combined and disposed within the cavity. The receiving coil is sleeved on the outside of the magnetic column. The lower end of the main shielding layer has two centrally symmetrical blind holes. Two receiving coils and two magnetic columns are respectively combined and disposed within the two blind holes. Two balancing resistors and two receiving coils are combined to form a bridge circuit structure. The two balancing resistors form two arms of the bridge circuit, and the two receiving coils form the other two arms of the bridge circuit. Both balancing resistors are disposed within the cavity.

[0004] Furthermore, the probe housing is cylindrical, and the upper end of the probe housing has a circular hole for installing a signal I / O plug.

[0005] Furthermore, the main shielding layer is cylindrical, and an annular groove is provided at the lower part of the main shielding layer. The annular groove divides the lower part of the main shielding layer into an annular region at the edge and a cylindrical region in the middle. The blind holes are symmetrically arranged in the cylindrical region. The excitation unit is fixed in the annular groove, and the receiving unit is fixed in the blind holes.

[0006] Furthermore, the sub-shielding layer is provided with a first U-shaped groove in the circumferential direction, and the sub-shielding layer is embedded in the annular groove through the first U-shaped groove.

[0007] Furthermore, the magnetic bowl is provided with a second U-shaped groove in the circumferential direction, and the magnetic bowl is embedded in the first U-shaped groove through the second U-shaped groove.

[0008] Furthermore, the excitation coil is a hollow solenoid coil, and the excitation coil is embedded in the second U-shaped groove.

[0009] Furthermore, the magnetic post is cylindrical, and its height is less than the depth of the blind hole.

[0010] Furthermore, the receiving coil is a hollow solenoid coil, and the height of the receiving coil is lower than the height of the magnetic post.

[0011] A detection method based on a far-field eddy current probe for automatic welding web positioning of the T-joint includes the following steps: Step S1) Connect the probe to the far-field eddy current detection device; Step S2) Place the probe on the surface of the wing plate 1001 of the T-shaped structural member 10 to be positioned, keeping the center line of the blind hole 202 perpendicular to the extension direction of the web plate 1002 of the T-shaped structural member 10. Step S3) Move the probe along a direction perpendicular to the extension of the web 1002, while maintaining good coupling between the probe and the surface of the wing plate 1001. Step S4) The excitation unit generates a low-frequency electromagnetic field that penetrates into the T-shaped structure 10. The magnetic bowl 4 confines the excitation magnetic field to the vicinity of the excitation coil 5. The main shielding layer 2 and the secondary shielding layer 3 prevent the excitation magnetic field from spreading to the surrounding area and being picked up by the receiving coil 7. When the excitation coil 5 comes into contact with the T-shaped structure 10 to be positioned, the excitation magnetic field is introduced into the T-shaped structure 10. (Step S5) The receiving unit receives the secondary magnetic field passing through the wing plate 1001 twice. The secondary magnetic field induces a magnetic field much stronger than its own strength in the magnetic column 6. The induced magnetic field generates an induced electromotive force in the excitation coil 5. When the induced electromotive forces in the two receiving coils 7 are equal, the bridge output voltage... V0=0, When the induced electromotive forces in the two receiving coils 7 are not equal, the bridge output voltage... V0≠0, The location of the probe is determined by analyzing the changes in V0. Step S6) Observe the change of V0 during the movement of the probe. When V0 reaches a minimum value, the probe is located directly above the web 1002, and the center line of the probe coincides with the center line of the web 1002. Step S7) Repeat steps S1 to S6 at different positions along the extension direction of the web 1002, and connect the points located each time to locate the accurate position of the web 1002.

[0012] Compared with the prior art, the present invention has the following technical effects: This invention provides an excitation / receiving unit mounting slot and mounting hole at the bottom of the probe. The excitation / receiving unit is located in the coil mounting slot and mounting hole. The receiving coil is connected by a bridge structure. The two receiving coils are placed on the surface of the component to be tested. By analyzing the voltage amplitude change of the eddy current signal impedance diagram, the internal structure of the component is determined, achieving precise positioning of the web of the T-joint, solving the technical problem of welding deviation during the automatic welding of T-joints, and improving the welding formation rate of H-plates. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the disassembled structure of the probe of the present invention; Figure 2 This is a schematic cross-sectional view of the probe of the present invention; Figure 3 This is a cross-sectional view of the detection process of the probe of the present invention; Figure 4 This is a circuit diagram of the receiving unit of the present invention; Figure 5 This is a diagram showing the positioning signals of the web plate of the present invention.

[0014] Figure label: 1. Probe housing; 2. Main shielding layer; 3. Secondary shielding layer; 4. Magnetizing cup; 5. Excitation coil. 6. Magnetic post, 7. Receiver coil, 8. Signal I / O connector, 9. Balancing resistor, 10. T-type structural component. 101 round hole, 102 cavity, 201 Annular groove, 202 Blind hole 301 First U-shaped groove, 401 Second U-shaped groove. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] This embodiment discloses a far-field eddy current probe for automatic welding web positioning of T-joints, such as... Figure 1 As shown, the device includes a probe housing 1, a main shielding layer 2, an excitation unit, and a receiving unit. The probe housing 1 is made of aluminum alloy. The excitation unit includes a secondary shielding layer 3, a magnetic cup 4, and an excitation coil 5. The receiving unit includes a magnetic column 6, a balancing resistor 9, and a receiving coil 7.

[0017] like Figure 2 As shown, the upper end of the probe housing 1 is provided with a signal I / O plug 8. The probe housing 1 is cylindrical, and the upper end of the probe housing 1 is provided with a circular hole 101 for installing the signal I / O plug 8. The diameter ∅1 of the circular hole 101 matches the diameter ∅2 of the I / O plug 8.

[0018] The main shielding layer 2, the secondary shielding layer 3, the magnetic cup 4, and the excitation coil 5 are sequentially connected along the outer periphery to form an integral structure. The probe housing 1 has a cylindrical space cavity 102 with an open lower end. The main shielding layer 2, the secondary shielding layer 3, the magnetic cup 4, and the excitation coil 5 are combined and arranged in the cavity 102. A gap is left between the outer wall of the main shielding layer 2 and the inner wall of the probe housing 1 for circuit wiring and glue injection.

[0019] The main shielding layer 2 is made of copper, which has high electrical conductivity and excellent magnetic field shielding performance. The main shielding layer 2 is cylindrical. The lower part of the main shielding layer 2 is provided with an annular groove 201 with a width w0=10mm. The annular groove 201 divides the lower part of the main shielding layer 2 into an edge annular region and a central cylindrical region. The width of the edge annular region is w1=3mm, and the diameter of the cylindrical region is ∅3=40mm. Two blind holes 202 are symmetrically arranged in the cylindrical region. The depth h1 of the annular groove 201 is equal to the depth h2 of the blind hole 202. The diameter of the blind hole 202 is ∅4=10mm, and the center distance between the two blind holes is d=12mm. The excitation unit is fixed in the annular groove 201, and the receiving unit is fixed in the blind hole 202.

[0020] Sub-shielding layer 3 is made of aluminum alloy, such as Figure 2 As shown, the sub-shielding layer 3 has a first U-shaped groove 301 in the circumferential direction with a wall thickness of 2mm. The sub-shielding layer 3 is embedded in the annular groove 201 through the first U-shaped groove. A gap of 0.5mm is left between the inner wall of the annular groove 201 and the outer wall of the sub-shielding layer 3. During the installation process, the lower end face of the sub-shielding layer 3 is kept flush with the lower end face of the main shielding layer 2. AB glue is poured into the gap for fixation. When the excitation magnetic field passes through the sub-shielding layer 3, eddy currents will be formed in the sub-shielding layer. The eddy currents generate a secondary magnetic field opposite to the direction of the excitation magnetic field, which hinders the diffusion of the excitation magnetic field to the surrounding area.

[0021] The magnetic bowl 4 is made of ferrite material with high magnetic permeability. The magnetic bowl 4 has a second U-shaped groove 401 with a wall thickness of 1mm along the circumference. The magnetic bowl 4 is embedded in the first U-shaped groove 301 through the second U-shaped groove 401. A gap of 0.5mm is left between the inner wall of the first U-shaped groove 301 and the outer wall of the second U-shaped groove 401. During the installation process, the lower end face of the magnetic bowl 4 is kept flush with the lower end face of the main shielding layer 2. AB glue is poured into the gap for fixation.

[0022] The magnetic bowl 4 forms a U-shaped structure that encloses the excitation coil 5. When the magnetic field generated by the excitation coil 5 spreads to the surroundings, the magnetic bowl 4 can concentrate the excitation magnetic field in the U-shaped structure and guide the excitation magnetic field into the T-shaped structure 10 from the bottom of the magnetic bowl 4.

[0023] The excitation coil 5 is a hollow solenoid coil. The wire currently used for the excitation coil 5 is 0.05mm diameter enameled copper wire with a wall thickness of 1mm. The excitation coil 5 is embedded in the second U-shaped groove 401, with a 0.5mm gap between the excitation coil 5 and the second U-shaped groove 401. During installation, the lower end face of the excitation coil 5 is kept flush with the lower end face of the main shielding layer 2. AB glue is poured into the gap for fixation. The number of coil turns can be adjusted according to the required excitation magnetic field strength.

[0024] Two receiving coils 7 and two magnetic pillars 6 are respectively arranged in two blind holes 202. During installation, the lower end face of the excitation receiving coil 7 and the magnetic pillar 6 is kept flush with the lower end face of the main shielding layer 2.

[0025] The magnetic column 6 is made of high permeability silicon steel. When an external magnetic field passes through the magnetic column, an induced magnetic field with a strength much greater than the initial magnetic field can be generated inside the magnetic column. The magnetic column 6 is a solid cylindrical structure with a diameter of 7mm. The height of the magnetic column 6 is less than the depth of the blind hole 202.

[0026] The receiving coil 7 is a hollow solenoid coil. The wire used for the receiving coil 7 is 0.04mm diameter enameled copper wire. The receiving coil 7 is sleeved on the outside of the magnetic post 6. The height of the receiving coil 7 is lower than the height of the magnetic post 6. During installation, a 0.5mm gap is maintained between the outer wall of the receiving coil 7 and the inner wall of the blind hole 202, and a 0.5mm gap is maintained between the inner wall of the receiving coil 7 and the arc surface of the magnetic post 6. The gaps are filled with AB glue for fixation.

[0027] like Figure 3As shown, two balancing resistors 9 and two receiving coils 7 are combined to form a bridge circuit structure. The two balancing resistors 9 form two arms of the bridge, and the two receiving coils 7 form the other two arms of the bridge. Both balancing resistors 9 are set inside the cavity 102. During the detection process, the two receiving coils 7 pick up the secondary magnetic field passing through the wing plate 1001 of the T-shaped structure 10 twice. When the received magnetic field strength of the two receiving coils 7 is equal, the output voltage of the bridge circuit is 0. When the received magnetic field strength of the two receiving coils 7 is not equal, the output voltage of the bridge circuit is not equal to 0. The location where the minimum value of the detection signal appears is the location of the web plate 1002 of the T-shaped structure 10.

[0028] Based on this embodiment, a detection method for a far-field eddy current probe for positioning the web of an automatic welding T-joint is described. (See also...) Figure 4 This includes the following steps: Step S1) Connect the probe to the far-field eddy current detection device; Step S2) Place the probe on the surface of the wing plate 1001 of the T-shaped structural member 10 to be positioned, keeping the center line of the blind hole 202 perpendicular to the extension direction of the web plate 1002 of the T-shaped structural member 10. Step S3) Move the probe along a direction perpendicular to the extension of the web 1002, while maintaining good coupling between the probe and the surface of the wing plate 1001. Step S4) The excitation unit generates a low-frequency electromagnetic field that penetrates into the T-shaped structure 10. The magnetic bowl 4 confines the excitation magnetic field to the vicinity of the excitation coil 5. The main shielding layer 2 and the secondary shielding layer 3 prevent the excitation magnetic field from spreading to the surrounding area and being picked up by the receiving coil 7. When the excitation coil 5 comes into contact with the T-shaped structure 10 to be positioned, the excitation magnetic field is introduced into the T-shaped structure 10. (Step S5) The receiving unit receives the secondary magnetic field passing through the wing plate 1001 twice. The secondary magnetic field induces a magnetic field much stronger than its own strength in the magnetic column 6. The induced magnetic field generates an induced electromotive force in the excitation coil 5. When the induced electromotive forces in the two receiving coils 7 are equal, the bridge output voltage... V0=0, When the induced electromotive forces in the two receiving coils 7 are not equal, the bridge output voltage... V0≠0, The location of the probe is determined by analyzing the changes in V0. Step S6) Observe the change of V0 during the movement of the probe. When V0 reaches a minimum value, the probe is located directly above the web 1002, and the center line of the probe coincides with the center line of the web 1002. Step S7) Repeat steps S1 to S6 at different positions along the extension direction of the web 1002, and connect the points located each time to locate the accurate position of the web 1002.

[0029] For the positioning signal diagram of the web plate 1002 in this embodiment, please refer to [link / reference]. Figure 5 .

[0030] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention specification and drawings, or directly or indirectly applied to other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A T-joint automatic web gap locating far-field eddy current probe characterized by, The probe comprises a probe shell (1), a main shielding layer (2), an excitation unit and a receiving unit, the excitation unit comprises a secondary shielding layer (3), a magnetic concentrating bowl (4) and an excitation coil (5), the receiving unit comprises a magnetic column (6), a balance resistor (9) and a receiving coil (7), the upper end of the probe shell (1) is provided with a signal I / O plug (8), the main shielding layer (2), the secondary shielding layer (3), the magnetic concentrating bowl (4) and the excitation coil (5) are sequentially sleeved along the outer periphery to form an integrated structure, the probe shell (1) is provided with a cavity (102) with an open lower end, the main shielding layer (2), the secondary shielding layer (3), the magnetic concentrating bowl (4) and the excitation coil (5) are combined and arranged in the cavity (102), the receiving coil (7) is sleeved outside the magnetic column (6), the central part of the lower end of the main shielding layer (2) is provided with two center-symmetric blind holes (202), the two receiving coils (7) and the two magnetic columns (6) are combined and arranged in the two blind holes (202) respectively, the two balance resistors (9) and the two receiving coils (7) are combined to form a bridge circuit structure, the two balance resistors (9) form two bridge arms of the bridge, the two receiving coils (7) form the other two bridge arms of the bridge, and the two balance resistors (9) are arranged in the cavity (102).

2. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 1, wherein, The probe shell (1) is in a cylindrical shape, and the upper end of the probe shell (1) is provided with a circular hole (101) for mounting the signal I / O plug (8).

3. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 1, wherein, The main shielding layer (2) is in a cylindrical shape, the lower part of the main shielding layer (2) is provided with an annular groove (201), the annular groove (201) divides the lower part of the main shielding layer (2) into a ring-shaped area with an edge and a cylindrical area in the middle, the blind holes (202) are symmetrically arranged in the cylindrical area, the excitation unit is fixed in the annular groove (201), and the receiving unit is fixed in the blind holes (202).

4. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 3, wherein, The secondary shielding layer (3) is provided with an annular first U-shaped groove (301) in the circumferential direction, and the secondary shielding layer (3) is embedded in the annular groove (201) through the first U-shaped groove.

5. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 4, wherein, The magnetic concentrating bowl (4) is provided with an annular second U-shaped groove (401) in the circumferential direction, and the magnetic concentrating bowl (4) is embedded in the first U-shaped groove (301) through the second U-shaped groove (401).

6. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 5, wherein, The excitation coil (5) is a hollow solenoid coil, and the excitation coil (5) is embedded in the second U-shaped groove (401).

7. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 1, wherein, The magnetic column (6) is in a cylindrical shape, and the height of the magnetic column (6) is less than the depth of the blind hole (202).

8. The T-joint automatic web-stiffening positioning far-field eddy current probe of claim 7, wherein, The receiving coil (7) is a hollow solenoid coil, and the height of the receiving coil (7) is lower than the height of the magnetic column (6).

9. A method of inspecting a T-joint automatic web positioning far field eddy current probe based on any one of claims 1-8, characterized in that, The method comprises the following steps: Step S1) connecting the probe to a far-field eddy current detection device; Step S2) placing the probe on the surface of the wing plate (1001) of the T-shaped structure (10) to be positioned, and keeping the center line of the blind hole (202) perpendicular to the extension direction of the web plate (1002) of the T-shaped structure (10); Step S3) moving the probe in a direction perpendicular to the extension of the web plate (1002), and keeping the probe well coupled with the surface of the wing plate (1001) during the movement. Step S4) The excitation unit generates a low-frequency electromagnetic field to penetrate into the T-shaped structure (10), the magnetic concentrating bowl (4) confines the excitation magnetic field near the excitation coil (5), the main shielding layer (2) and the auxiliary shielding layer (3) prevent the excitation magnetic field from spreading to the surrounding and being picked up by the receiving coil (7), when the excitation coil (5) contacts the T-shaped structure (10) to be positioned, the excitation magnetic field is introduced into the T-shaped structure (10); Step S5) The receiving unit receives the secondary magnetic field twice through the wing plate (1001), the secondary magnetic field induces a magnetic field much larger than its own strength in the magnetic column (6), and the induced magnetic field generates an induced electromotive force in the excitation coil (5), When the induced electromotive forces in the two receiving coils (7) are equal, the output voltage V0 of the bridge is 0, When the induced electromotive forces in the two receiving coils (7) are not equal, the output voltage V0 of the bridge is not 0, The position of the probe is determined by analyzing the change of V0; Step S6) Observe the change of V0 during the movement of the probe, when V0 appears a minimum value, the probe is located directly above the web plate (1002), and the center line of the probe coincides with the center line of the web plate (1002); Step S7) Repeat the above steps S1~S6 at different positions in the extension direction of the web plate (1002), and connect the points positioned each time to locate the accurate position of the web plate (1002).

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