An eddy current flaw detector probe

Abstract

The utility model provides a kind of eddy flaw detection probe, belong to eddy flaw detection probe technical field, the eddy flaw detection probe includes probe shell, coil assembly and positioning assembly, the probe shell is cylindrical structure, and the one end of probe shell is equipped with open end face, and the other end of probe shell is equipped with closed end face;The coil assembly is arranged inside probe shell, and coil assembly includes annular coil framework and excitation coil wound on annular coil framework, and the geometric center axis of annular coil framework coincides with the geometric center axis of probe shell;The positioning assembly is arranged at the open end face of probe shell;It can solve the problem that the eddy flaw detection probe in prior art is contacted with the surface of the workpiece to be detected, due to the unreasonable structure design of contact part, leading to the frictional resistance of probe when moving on the surface of workpiece, it is difficult to move smoothly, and the unstable contact state leads to the posture of probe to be easily deviated, the precision and efficiency of eddy flaw detection are affected.

Description

Technical Field

[0001] This utility model belongs to the field of eddy current flaw detection probe technology, specifically, it relates to an eddy current flaw detection probe. Background Technology

[0002] Eddy current testing is a non-destructive testing method for conductive materials that utilizes the principle of electromagnetic induction. It is widely used in aerospace, petrochemical, power energy, and machinery manufacturing industries to detect surface and near-surface defects such as cracks, porosity, and inclusions in metal workpieces. The eddy current probe, as the core component of eddy current testing equipment, directly affects the accuracy and efficiency of the test. Existing eddy current probes typically employ a cylindrical or square shell structure with an internal excitation coil, and the probe tip directly contacts the surface of the workpiece. In practical applications, operators need to hold the probe and move it across the workpiece surface for scanning. The contact tip of existing probes usually uses a planar or large-radius arc surface structure, resulting in a large contact area between the probe and the workpiece surface. This generates significant frictional resistance during testing, making smooth probe movement difficult and requiring operators to apply considerable force, increasing the labor intensity of the testing operation. Furthermore, due to the large contact area and improper contact method, the probe is prone to attitude deviation during movement, affecting the relative positional relationship between the excitation coil and the workpiece, leading to unstable test data and increased errors. Especially when inspecting workpieces with curved shapes or uneven surfaces, the flat or large arc contact ends of existing probes cannot adapt well to the shape changes of the workpiece surface, which easily leads to poor contact or unstable contact conditions, seriously affecting the accuracy and reliability of flaw detection. Utility Model Content

[0003] In view of this, the present invention provides an eddy current flaw detection probe, which can solve the problems of existing eddy current flaw detection probes when in contact with the surface of the workpiece. Due to unreasonable structural design of the contact part, the contact area between the probe and the workpiece surface is too large or the contact method is inappropriate. This results in high frictional resistance when the probe moves on the workpiece surface, making it difficult to move smoothly. At the same time, the unstable contact state causes the probe posture to easily deviate, affecting the accuracy and efficiency of eddy current flaw detection. In particular, when detecting workpieces with different curvatures or surface conditions, the probe has poor adaptability and cannot guarantee stable and reliable detection results.

[0004] This utility model is implemented as follows:

[0005] This utility model provides an eddy current flaw detection probe, comprising a probe housing, a coil assembly, and a positioning assembly. The probe housing has a cylindrical structure, with an open end face at one end and a closed end face at the other end. The coil assembly is disposed inside the probe housing and includes an annular coil skeleton and an excitation coil wound on the annular coil skeleton. The geometric center axis of the annular coil skeleton coincides with the geometric center axis of the probe housing. The positioning assembly is disposed at the open end face of the probe housing and includes a positioning seat and a contact boss fixedly connected to the positioning seat. The positioning seat has an annular structure and is threadedly connected to the open end face of the probe housing. The contact boss extends from the inner circumferential surface of the positioning seat toward the geometric center axis of the probe housing, and the end surface of the contact boss is spherical. When the eddy current flaw detection probe contacts the surface of the workpiece being inspected, the spherical end of the contact boss makes point contact or line contact with the surface of the workpiece being inspected.

[0006] The technical advantages of the eddy current flaw detection probe provided by this utility model are as follows: By aligning the geometric center axis of the annular coil skeleton of the coil assembly with the geometric center axis of the probe housing, the symmetry and uniformity of the electromagnetic field distribution generated by the excitation coil are ensured, thereby improving the detection accuracy of eddy current flaw detection; by setting a contact boss with a spherical end on the positioning assembly, point contact or line contact can be achieved when the probe contacts the surface of the workpiece being inspected, reducing the contact area, reducing frictional resistance, and facilitating smooth movement of the probe on the workpiece surface. At the same time, the spherical end can adapt to workpiece surfaces with different curvatures, improving the applicability and detection flexibility of the probe.

[0007] Based on the above technical solution, the eddy current flaw detection probe of this utility model can be further improved as follows:

[0008] Wherein, the extension length of the contact boss along the radial direction of the probe housing is greater than the thickness of the positioning seat along the radial direction of the probe housing.

[0009] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by making the radial extension length of the contact boss along the probe housing greater than the radial thickness of the positioning seat along the probe housing, the contact boss can extend fully towards the center of the probe. Thus, when the probe contacts the workpiece, the spherical end of the contact boss can contact the workpiece surface first, avoiding interference between other parts of the positioning seat and the workpiece surface. This ensures that the spherical end of the contact boss is the main contact part, guarantees a stable contact state between the probe and the workpiece, and improves the accuracy of the probe position during the detection process.

[0010] Furthermore, an annular gap is formed between the inner circumferential surface of the annular coil skeleton and the inner circumferential surface of the probe housing, and the radial width of the annular gap remains consistent along the axial direction of the probe housing.

[0011] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by forming an annular gap with a radial width that is consistent along the axial direction between the inner circumferential surface of the annular coil frame and the inner circumferential surface of the probe housing, a uniform heat dissipation space is provided between the coil frame and the housing. This allows the heat generated when the excitation coil is working to be uniformly conducted to the probe housing and dissipated outward through the annular gap, avoiding the occurrence of local overheating, ensuring the stability of the coil assembly under long-term working conditions, extending the service life of the probe, and at the same time, the uniform gap also facilitates the assembly and maintenance of the probe.

[0012] Furthermore, the radius of curvature of the spherical end of the contact boss is smaller than the radius of curvature of the outer circumferential surface of the probe housing.

[0013] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by making the radius of curvature of the spherical end of the contact boss smaller than the radius of curvature of the outer circumferential surface of the probe housing, the end of the contact boss has a smaller contact area and higher local stiffness. When the probe moves on the workpiece surface, the spherical end with a smaller radius of curvature can be more accurately positioned at a specific location on the workpiece surface, reducing the positional offset caused by excessive contact area, improving the spatial resolution of flaw detection, and enabling the probe to more accurately detect the location and range of minute defects on the workpiece surface.

[0014] Furthermore, three contact bosses are evenly distributed along the circumferential direction on the inner circumferential surface of the positioning seat, and the spherical ends of the three contact bosses are located on the same circumference.

[0015] The beneficial effects of the above-mentioned improvement scheme are as follows: by uniformly distributing three contact bosses along the circumferential direction on the inner circumferential surface of the positioning seat, and ensuring that the spherical ends of the three contact bosses are located on the same circumference, a stable three-point support structure is formed. When the probe contacts the workpiece surface, the three contact bosses can simultaneously contact the workpiece surface, forming a stable support plane. This avoids the probe from tilting or shaking during the detection process, ensures a stable relative positional relationship between the probe and the workpiece surface, and improves the reliability and repeatability of the detection data.

[0016] Furthermore, the inner circumferential surface of the positioning seat between two adjacent contact bosses is arc-shaped concave, and the radius of curvature of the arc-shaped concave is greater than the radius of curvature of other parts of the inner circumferential surface of the positioning seat.

[0017] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by setting an arc-shaped recess with a large radius of curvature on the inner circumferential surface of the positioning seat between two adjacent contact bosses, a space is provided to accommodate any protrusions or uneven areas that may exist on the surface of the workpiece being inspected. This avoids interference between the inner circumferential surface of the positioning seat and the non-contact boss area of ​​the workpiece surface, ensuring that only the spherical end of the contact boss contacts the workpiece surface. This prevents probe posture deviation caused by other parts of the positioning seat contacting the workpiece, and ensures that the probe can maintain the correct detection posture under various workpiece surface conditions.

[0018] Furthermore, the closed end face of the probe housing is provided with a wire through hole, through which the lead wire of the excitation coil passes and connects to the external circuit. The geometric center of the wire through hole is offset from the geometric center axis of the probe housing.

[0019] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by setting a wire through hole with the geometric center offset from the geometric center axis of the probe housing on the closed end face, the lead wire of the excitation coil can be led out from the side of the probe instead of from the center position, which avoids the influence of the wire on the electromagnetic field distribution in the central area of ​​the probe. At the same time, the off-center wire arrangement facilitates the bending and fixing of the wire, reduces the risk of fatigue fracture caused by repeated bending of the wire during the use of the probe, and improves the reliability and durability of the probe.

[0020] Furthermore, the probe housing is made of a non-magnetic metallic material.

[0021] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by using non-magnetic metal materials to make the probe housing, the interference and shielding effect of the housing material on the electromagnetic field generated by the coil assembly are avoided, ensuring that the eddy current generated by the excitation coil can effectively penetrate the housing and generate induced current in the workpiece being inspected, thereby improving the sensitivity and accuracy of flaw detection. At the same time, non-magnetic metal materials have good mechanical strength and corrosion resistance, providing reliable protection for the coil assembly and extending the service life of the probe.

[0022] Furthermore, the annular coil frame is a hollow circular structure, and the axial length of the annular coil frame is less than the axial length of the probe housing cavity.

[0023] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by designing the ring coil skeleton as a hollow ring structure and making its axial length less than the axial length of the probe housing cavity, the overall weight of the probe is reduced while ensuring that the coil skeleton has sufficient mechanical strength, thereby reducing the fatigue of operators during long-term testing operations. At the same time, the hollow structure provides additional heat dissipation channels inside the coil skeleton, further improving the heat dissipation performance of the probe and ensuring the temperature stability of the probe under high frequency and long-term working conditions.

[0024] Furthermore, the outer circumferential surface of the positioning seat is provided with several anti-slip ridges extending along the axial direction, and the radial height of the anti-slip ridges is evenly distributed along the axial direction.

[0025] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by setting several anti-slip ridges that extend axially and are evenly distributed radially in the axial direction on the outer circumferential surface of the positioning seat, the friction between the outer surface of the positioning seat and the operator's fingers is increased, which makes it easier for the operator to apply sufficient torque when installing and disassembling the positioning seat, avoiding slippage caused by the smooth surface of the positioning seat. At the same time, the even distribution of anti-slip ridges ensures the comfort of holding the seat and improves the convenience of probe assembly and maintenance.

[0026] Compared with existing technologies, the beneficial effects of the eddy current flaw detection probe provided by this utility model are as follows: This utility model achieves point or line contact between the probe and the workpiece surface by setting a positioning assembly including a positioning seat and a contact boss on the open end face of the probe housing, and designing the contact boss as a spherical end, effectively reducing the contact area and frictional resistance, allowing the probe to move smoothly on the workpiece surface and improving the efficiency of the inspection operation; by aligning the geometric center axis of the coil assembly with the geometric center axis of the probe housing, the symmetry and uniformity of the electromagnetic field distribution are ensured, improving the accuracy of flaw detection; by uniformly distributing three contact bosses along the circumferential direction on the positioning seat, a stable three-point support structure is formed, avoiding… This invention eliminates the tilting and shaking of the probe during the inspection process, ensuring the stability of the probe's posture. By setting arc-shaped recesses between the contact bosses, it provides space to accommodate uneven areas on the workpiece surface, allowing the probe to adapt to workpieces with different surface conditions and improving its applicability. Using a non-magnetic metal material for the probe housing avoids interference with the electromagnetic field, ensuring the sensitivity of the flaw detection. Optimizing the gap design between the ring coil frame and the probe housing improves the probe's heat dissipation performance, ensuring its stability during long-term operation. Compared with existing technologies, this eddy current flaw detection probe has the advantages of high detection accuracy, flexible movement, stable posture, wide applicability, and high reliability. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of an eddy current flaw detection probe.

[0029] Figure 2 This is a structural diagram of the positioning component;

[0030] Figure 3 This is a schematic diagram of the coil assembly.

[0031] The attached diagram lists the components represented by each number as follows:

[0032] 10. Probe housing; 20. Coil assembly; 21. Ring coil frame; 22. Excitation coil; 30. Positioning assembly; 31. Positioning seat; 32. Contact boss. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0034] like Figure 1-3 The diagram shows a schematic of the structure of an eddy current flaw detection probe provided by this utility model. The probe includes a probe housing 10, a coil assembly 20, and a positioning assembly 30. The probe housing is cylindrical, with an open end face at one end and a closed end face at the other. The coil assembly is located inside the probe housing and includes an annular coil frame 21 and an excitation coil 22 wound around the annular coil frame. The geometric center axis of the annular coil frame coincides with the geometric center axis of the probe housing. The positioning assembly is located at the open end face of the probe housing and includes a positioning seat 31 and a contact boss 32 fixedly connected to the positioning seat. The positioning seat has an annular structure and is threadedly connected to the open end face of the probe housing. The contact boss extends from the inner circumferential surface of the positioning seat towards the geometric center axis of the probe housing. The end surface of the contact boss is spherical. When the eddy current flaw detection probe contacts the surface of the workpiece being tested, the spherical end of the contact boss makes point or line contact with the surface of the workpiece.

[0035] In the above technical solution, the extension length of the contact boss along the radial direction of the probe housing is greater than the thickness of the positioning seat along the radial direction of the probe housing.

[0036] Furthermore, in the above technical solution, an annular gap is formed between the inner circumferential surface of the annular coil skeleton and the inner circumferential surface of the probe housing, and the radial width of the annular gap remains consistent along the axial direction of the probe housing.

[0037] Furthermore, in the above technical solution, the radius of curvature of the spherical end of the contact boss is smaller than the radius of curvature of the outer circumferential surface of the probe housing.

[0038] Furthermore, in the above technical solution, three contact bosses are evenly distributed along the circumferential direction on the inner circumferential surface of the positioning seat, and the spherical ends of the three contact bosses are located on the same circumference.

[0039] Furthermore, in the above technical solution, the inner circumferential surface of the positioning seat between two adjacent contact bosses is an arc-shaped depression, and the radius of curvature of the arc-shaped depression is greater than the radius of curvature of other parts of the inner circumferential surface of the positioning seat.

[0040] Furthermore, in the above technical solution, a wire through hole is provided on the closed end face of the probe housing, and the lead wire of the excitation coil passes through the wire through hole to connect with the external circuit. The geometric center of the wire through hole is offset from the geometric center axis of the probe housing.

[0041] Furthermore, in the above technical solution, the probe housing is made of a non-magnetic metal material.

[0042] Furthermore, in the above technical solution, the ring coil frame is a hollow circular ring structure, and the axial length of the ring coil frame is less than the axial length of the probe housing cavity.

[0043] Furthermore, in the above technical solution, the outer circumferential surface of the positioning seat is provided with several anti-slip ridges extending along the axial direction, and the radial height of the anti-slip ridges is evenly distributed along the axial direction.

[0044] The following is a specific embodiment 1 of this utility model: The probe housing of the eddy current flaw detection probe of this embodiment is made of aluminum alloy material through machining. The probe housing has a cylindrical structure with an outer diameter of 18mm, a wall thickness of 2mm, and a total length of 65mm. One end of the probe housing is an open end face, which is flat and perpendicular to the housing axis. The other end is a closed end face, and a wire through hole with a diameter of 3mm is opened on the closed end face at a distance of 4mm from the geometric center axis. The annular coil frame of the coil assembly is injection molded from polyimide plastic material, and has a hollow annular structure with an outer diameter of 14mm, an inner diameter of 8mm, an axial length of 30mm, and a wall thickness of 1.5mm. Spiral grooves are machined on the outer circumferential surface of the annular coil frame. The grooves have a width of 0.8mm, a depth of 0.5mm, and a spacing of 0.3mm between adjacent grooves. The excitation coil uses 0.2mm diameter polyester enameled copper wire, evenly wound 500 turns on a ring-shaped coil skeleton in the spiral direction of the wire groove. Two lead wires of the coil are led out from one end of the coil skeleton, passing through the wire through-hole on the closed end face of the probe housing, and connected to the external eddy current flaw detector. During assembly, the ring-shaped coil skeleton with the excitation coil wound is inserted into the probe housing from the open end. The position of the coil skeleton is adjusted so that its geometric center axis coincides with the geometric center axis of the probe housing. A radially wide annular gap of 1mm is formed between the outer circumferential surface of the coil skeleton and the inner circumferential surface of the probe housing, and this annular gap remains consistent along the axial direction of the probe housing. The positioning seat of the positioning assembly is made of stainless steel and machined into a ring structure with an outer diameter of 22mm, an inner diameter of 12mm, and an axial thickness of 8mm. The inner circumferential surface of the positioning seat extends outward to form an external thread with a pitch of 1.5mm. Three contact bosses are uniformly machined at 120° intervals along the circumferential direction on the inner circumferential surface of the positioning base. Each contact boss extends 5 mm from the inner circumferential surface of the positioning base towards the geometric center axis of the probe housing. The cross-section of the contact boss is rectangular, with a width of 3 mm and a height of 2 mm. The ends of the contact bosses are machined into hemispherical shapes with a radius of curvature of 2 mm. The highest points of the spherical ends of the three contact bosses are located on the same circumference with a diameter of 10 mm. The inner circumferential surface of the positioning base between two adjacent contact bosses is machined into an arc-shaped recess with a radius of curvature of 15 mm. The deepest part of the recess is recessed outward by 1 mm compared to other parts of the inner circumferential surface of the positioning base. Eight anti-slip ridges are machined along the axial direction on the outer circumferential surface of the positioning base. Each anti-slip ridge extends 6 mm along the axial direction and has a radial height of 0.5 mm. The circumferential spacing between adjacent anti-slip ridges is equal. The outer circumference of the open end face of the probe housing is machined with an internal thread that matches the external thread of the positioning seat. The positioning seat is screwed into the open end face of the probe housing, and the positioning component is fixed to the probe housing through the threaded connection.The eddy current flaw detection probe of this embodiment is suitable for detecting cracks and defects on the surface of planar or cylindrical workpieces with a large radius of curvature. In use, the three contact bosses of the probe are placed on the workpiece surface. Since the spherical ends of the contact bosses form point contact with the workpiece surface, the frictional resistance is small when the probe moves on the workpiece surface, and the movement is smooth. The three-point support structure ensures the stability of the probe posture. The electromagnetic field generated by the excitation coil induces eddy currents in the workpiece. When there are defects such as cracks on the workpiece surface, the eddy current distribution changes. By detecting the changes in eddy currents, the defect location can be accurately located. The probe of this embodiment has a simple structure, low manufacturing cost, high detection accuracy, and is easy to operate.

[0045] The following is another specific embodiment 2 of this utility model: Embodiment 2 is based on Embodiment 1, but the radius of curvature of the spherical end of the contact boss is changed from 2mm to 1.5mm, resulting in a smaller radius of curvature at the end of the contact boss. This further reduces the contact area when the probe contacts the workpiece surface, lowering the frictional resistance during probe movement, making it particularly suitable for applications requiring rapid scanning and detection on the workpiece surface. Simultaneously, the number of contact bosses on the inner circumferential surface of the positioning seat is increased from 3 to 4. The four contact bosses are evenly distributed at 90° intervals along the circumference, with the spherical ends of the four contact bosses located on the same circumference, forming a four-point support structure. The radius of curvature of the arc-shaped recess on the inner circumferential surface of the positioning seat between two adjacent contact bosses is adjusted to 18mm, and the recess depth is adjusted to 1.2mm, providing a larger accommodating space for uneven areas on the workpiece surface. Compared with the three-point support, the four-point support structure of this embodiment has higher stability and is particularly suitable for detecting workpieces with poor surface conditions or many protrusions. The four contact points can better adapt to the undulations of the workpiece surface, ensuring that the probe can maintain a stable detection posture under various surface conditions and improving the reliability of detection.

[0046] The following is another specific embodiment 3 of this utility model: Embodiment 3 is based on Embodiment 1, in which thermally conductive silicone is filled into the annular gap between the annular coil frame and the probe housing. The thermally conductive silicone is a silicon-based thermally conductive material with a thermal conductivity of 3 Kelvin per meter, and the filling thickness is 1 mm, consistent with the radial width of the annular gap. The filling of thermally conductive silicone enhances the thermal conductivity between the coil assembly and the probe housing. When the excitation coil generates heat under high-frequency operation, the heat can be quickly conducted to the probe housing through the thermally conductive silicone and dissipated outwards, effectively reducing the operating temperature of the coil assembly and improving the temperature stability and reliability of the probe under long-term continuous operation. Simultaneously, the diameter of the wire through-hole on the closed end face of the probe housing is increased from 3 mm to 4 mm, and a rubber sealing ring is installed at the wire through-hole. The sealing ring is made of nitrile rubber material, with an inner diameter of 3 mm, an outer diameter of 4 mm, and a thickness of 1 mm. The sealing ring is fitted onto the lead wire and embedded in the wire through-hole, sealing the wire through-hole and preventing external dust and moisture from entering the probe housing, improving the probe's protective performance, enabling the probe to adapt to harsher working environments, and extending its service life.

[0047] Specifically, the principle of this invention is as follows: This invention provides a positioning assembly, including a positioning seat and a contact boss, on the open end face of the probe housing. The end of the contact boss is designed in a spherical shape. Utilizing the geometric characteristics of point or line contact formed when a sphere contacts a plane or curved surface, the actual contact area between the probe and the workpiece surface is significantly reduced. Based on the principle that friction is proportional to the contact area, the reduction in contact area directly reduces the frictional resistance of the probe when moving on the workpiece surface, allowing the probe to move easily and smoothly on the workpiece surface, improving the efficiency and comfort of the inspection operation. Simultaneously, the spherical contact end has isotropic contact characteristics, adapting to workpiece surfaces with different curvatures and directions. When the probe contacts a curved workpiece, the spherical end can automatically adjust the contact angle to maintain a stable contact state, avoiding probe posture deviation caused by changes in the workpiece surface shape. By evenly distributing three contact bosses along the circumferential direction on the inner circumferential surface of the positioning base, a geometrically stable three-point support structure is formed. According to geometric principles, three points determine a plane. When the spherical ends of the three contact bosses simultaneously contact the workpiece surface, a stable support plane is formed, effectively preventing probe tilting and wobbling, and ensuring a stable relative positional relationship between the probe and the workpiece surface. By aligning the geometric center axis of the annular coil frame with the geometric center axis of the probe housing, the electromagnetic field generated by the excitation coil is ensured to be axially symmetrically distributed with respect to the probe housing. When the probe is stably placed on the workpiece surface, the symmetrical electromagnetic field can generate uniformly distributed eddy currents in the workpiece, improving the sensitivity and accuracy of flaw detection. By setting arc-shaped recesses between adjacent contact bosses, space is provided to accommodate any protrusions or uneven areas on the workpiece surface, avoiding interference between the non-contact parts of the positioning base and the workpiece surface, ensuring that only the spherical ends of the contact bosses contact the workpiece, and maintaining the correct detection posture of the probe.

[0048] During use, the operator first checks that all components of the eddy current flaw detector probe are intact, confirming that the contact bosses of the positioning assembly are clean and undamaged. The probe's lead wires are then connected to the output port of the eddy current flaw detector. The detector is then started and appropriate detection parameters are set. With the positioning assembly end face of the probe facing the workpiece surface, the probe is gently placed on the workpiece surface. At this time, the spherical ends of the three contact bosses on the positioning base will simultaneously contact the workpiece surface, forming a stable three-point support. The operator holds the probe housing and smoothly moves the probe along the predetermined detection path on the workpiece surface. Because the spherical ends of the contact bosses form point or line contact with the workpiece surface, the frictional resistance during probe movement is very small. The operator only needs to apply a slight pushing force to make the probe move smoothly. During movement, the probe housing axis is kept perpendicular to the workpiece surface or at the angle required by the inspection specifications. The eddy current flaw detector will display the signals detected by the probe in real time. When the probe moves to a location on the workpiece surface where a defect exists, the eddy current flaw detector's display screen will show an abnormal signal indication. The operator should focus on inspecting this location, slowly moving the probe to determine the specific range of the defect. After the test is completed, remove the probe from the workpiece surface, turn off the power of the eddy current flaw detector, clean the contact boss surface of the probe, and properly store the probe for future use.

Claims

1. An eddy current flaw detection probe, characterized in that, The device includes a probe housing, a coil assembly, and a positioning assembly. The probe housing is cylindrical with an open end face at one end and a closed end face at the other end. The coil assembly is located inside the probe housing and includes a ring-shaped coil frame and an excitation coil wound around the ring-shaped coil frame. The geometric center axis of the ring-shaped coil frame coincides with the geometric center axis of the probe housing. The positioning assembly is located at the open end face of the probe housing and includes a positioning seat and a contact boss fixedly connected to the positioning seat. The positioning seat is annular and is threadedly connected to the open end face of the probe housing. The contact boss extends from the inner circumferential surface of the positioning seat toward the geometric center axis of the probe housing. The end surface of the contact boss is spherical. When the eddy current flaw detection probe contacts the surface of the workpiece being inspected, the spherical end of the contact boss makes point or line contact with the surface of the workpiece being inspected.

2. The eddy current flaw detection probe according to claim 1, characterized in that, The contact boss extends radially beyond the probe housing, which is greater than the thickness of the positioning seat radially beyond the probe housing.

3. The eddy current flaw detection probe according to claim 2, characterized in that, An annular gap is formed between the inner circumferential surface of the annular coil frame and the inner circumferential surface of the probe housing, and the radial width of the annular gap remains consistent along the axial direction of the probe housing.

4. The eddy current flaw detection probe according to claim 3, characterized in that, The radius of curvature of the spherical end of the contact boss is smaller than the radius of curvature of the outer circumferential surface of the probe housing.

5. An eddy current flaw detection probe according to claim 4, characterized in that, The positioning seat has three contact bosses evenly distributed along the circumferential direction on its inner circumferential surface, and the spherical ends of the three contact bosses are located on the same circumference.

6. The eddy current flaw detection probe according to claim 5, characterized in that, The inner circumferential surface of the positioning seat between two adjacent contact bosses is an arc-shaped depression, and the radius of curvature of the arc-shaped depression is greater than the radius of curvature of other parts of the inner circumferential surface of the positioning seat.

7. An eddy current flaw detection probe according to claim 6, characterized in that, The probe housing has a wire through hole on its closed end face. The lead wire of the excitation coil passes through the wire through hole and is connected to the external circuit. The geometric center of the wire through hole is offset from the geometric center axis of the probe housing.

8. The eddy current flaw detection probe according to claim 7, characterized in that, The probe housing is made of non-magnetic metallic material.

9. An eddy current flaw detection probe according to claim 8, characterized in that, The annular coil frame is a hollow circular structure, and the axial length of the annular coil frame is less than the axial length of the inner cavity of the probe housing.

10. An eddy current flaw detection probe according to claim 9, characterized in that, The outer circumferential surface of the positioning seat is provided with several anti-slip ridges extending along the axial direction, and the radial height of the anti-slip ridges is evenly distributed along the axial direction.

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