A magnetic particle flaw detection probe for deep hole inner wall flaw detection

Abstract

This invention relates to the field of deep hole internal wall flaw detection equipment, specifically to a magnetic particle flaw detection probe for deep hole internal wall flaw detection. The probe includes a central column with a supply channel for introducing magnetic suspension fluid at its center. A ring-shaped negative pressure return cavity is located near the outer periphery of the central column. An excitation assembly is fixedly connected to the front end of the inner side of the central column. Several return grooves communicating with the negative pressure return cavity are located on the outer side of the central column. A nozzle module is rotatably connected to the outlet end of the supply channel. Several elastic petal modules, arranged in a circumferential array and opening to guide residual fluid into the return grooves, are movably connected to the front end of the outer side of the central column. This invention integrates a front-end central camera and a camera ring embedded in the outer wall of the central column, respectively acquiring axial images of the bottom of the blind hole and circumferential ring-shaped magnetic particle distribution images of the corresponding area of ​​the excitation assembly, forming a dual-dimensional imaging coverage of axial bottom view + circumferential ring-shaped image, thus solving the problem of blind zone limitations of a single camera.

Description

Technical Field

[0001] This invention relates to the field of deep hole internal wall flaw detection equipment, specifically to a magnetic particle flaw detection probe for deep hole internal wall flaw detection. Background Technology

[0002] In the fields of military weapon manufacturing and quality inspection of heavy energy equipment, microscopic physical defects (such as metallurgical folds, quenching cracks, rough machining tears, etc.) in the inner wall of deep holes (such as projectile bodies, special seamless steel pipes, aerospace hydraulic actuators, etc.) are the core causes of structural fatigue failure, and need to be accurately characterized through non-destructive testing. Among existing deep-hole internal wall inspection technologies, ultrasonic testing requires acoustic coupling agents and is sensitive to surface roughness, while machine vision can only detect macroscopic open defects; neither can meet the detection requirements for micron-level closed cracks. Magnetic particle testing, with its high sensitivity to surface and near-surface defects, has become a commonly used surface inspection method in the field of special steel pipelines, but it still faces severe challenges in extreme deep-hole environments. First, in the deep hole flaw detection of small-caliber projectiles, in order to meet the magnetomotive force specifications, a sufficiently large excitation component and iron core need to be arranged, occupying more than 80% of the net space of the deep hole cross section. This causes the probe body to block the light path, and the remaining optical slits have insufficient light intake and insufficient depth of field. The fixed mapping area of ​​the reflector is limited, and the probe needs to be rotated frequently to complete the 360° detection, which is inefficient and easily damages the hole wall. Secondly, since blind hole structures such as shells have no drainage channel at the bottom, traditional one-way open-loop spraying causes the magnetic suspension to converge at the bottom, forming a turbid pool that submerges the leakage magnetic field. At the same time, the middle and front sections of the hole wall lack liquid, and the magnetic powder cannot migrate to form an effective magnetic trace. Existing probes lack a closed-loop fluid recovery network, and waste liquid cannot be pumped out in situ, resulting in the bottom defects being missed. In addition, in traditional forward-moving inspection operations, the residual liquid after spraying will flow and splash along the hole wall, continuously contaminating the uninspected inner wall surface, resulting in large background interference of magnetic traces and low defect identification accuracy during subsequent station inspections.

[0003] In view of this, the present invention proposes a magnetic particle inspection probe for deep hole inner wall inspection. Summary of the Invention

[0004] This invention provides a magnetic particle inspection probe for deep hole inner wall flaw detection, which solves the problems in the prior art where the excitation component and iron core occupy too much volume, causing the probe body to block the light path, resulting in low detection efficiency, and the lack of residual liquid recovery structure, which easily leads to missed defects and misjudgments.

[0005] The technical solution of the present invention is as follows: A magnetic particle inspection probe for deep hole internal wall flaw detection includes a central column, a liquid supply channel for introducing magnetic suspension fluid is opened at the center of the central column, a ring-shaped negative pressure reflux cavity is opened inside the central column near the outer periphery, an excitation assembly is fixedly connected to the front end of the inner side of the central column, and a plurality of reflux grooves arranged in a circumferential array and communicating with the negative pressure reflux cavity are opened on the outer side of the central column. A negative pressure interface is opened at one end of the negative pressure reflux cavity, and a negative pressure device is connected to the negative pressure interface through a conduit. The inlet end of the channel is connected to a magnetic suspension supply device via a conduit; the outlet end of the supply channel is rotatably connected to a nozzle module for uniformly spraying the magnetic suspension in the supply channel; the front end of the outer side of the central column is movably connected to an elastic petal module; the inner side of the guide petal is provided with a flow channel, and the end position of the flow channel corresponds to the opening position of the return channel; the elastic petal module contains several guide petals arranged in a circumferential array; when the guide petals are open, the corrugated elastic ring on the inner surface forms a continuous annular collection surface to guide the residual liquid into the return channel.

[0006] In the above scheme, the magnetic suspension is delivered to the nozzle module through the liquid supply channel to achieve uniform spraying. The excitation component generates a magnetic field when energized, causing magnetic powder to be adsorbed at the defects of the hole wall to form magnetic traces. The negative pressure return chamber, together with the return tank, performs directional negative pressure suction and recovery of excess magnetic suspension and residual liquid. The elastic petal module, in the open state, adheres to the hole wall to form a liquid collection barrier, effectively preventing residual liquid from flowing towards the hole opening and contaminating the undetected area, thus realizing an integrated closed-loop operation of spraying, magnetization and recovery.

[0007] The external negative pressure device maintains a continuous negative pressure in the negative pressure return chamber, which creates a directional suction force field at the opening of the return tank. The residual liquid is guided and gathered, and then quickly sucked into the negative pressure return chamber and discharged for recycling. The residual liquid collection rate is improved, and the recycled magnetic suspension can be recycled, reducing the cost of consumables.

[0008] Driven by the elastic connector, the guide petals open outwards, and the corrugated elastic ring stretches synchronously with the opening and closing of the guide petals, forming a complete and closed annular liquid collection funnel. Excess magnetic suspension and residual liquid flowing down the hole wall are blocked and guided by the corrugated elastic ring, and instead flow into the diversion channel and are guided to the precisely aligned return channel opening at the end, blocking the residual liquid from leaking backward along the petal splice seam, effectively preventing waste magnetic suspension from contaminating the untested inner wall surface, and ensuring that the magnetic trace background of subsequent testing stations is clean and interference-free.

[0009] Preferably, the nozzle module includes a nozzle, one end of which is fixedly connected to a hollow rotating shaft. The inlet end of the hollow rotating shaft is rotatably connected to the inner wall of the liquid supply channel and communicates with the inside of the liquid supply channel. The inner wall of the nozzle is provided with a spiral groove, and the side wall of the nozzle is provided with a plurality of spirally distributed spray holes. The front end of the nozzle is fixedly connected to a central camera for capturing images of the bottom of the blind hole. The outer wall of the nozzle is movably connected to two baffle assemblies symmetrically distributed along the center line of the nozzle.

[0010] In the above scheme, when the magnetic suspension flows through the spiral grooves on the inner wall of the nozzle, the flow direction is forcibly rewritten as a tangential motion along the spiral line, generating a continuously rotating swirling pressurization component. The rotating magnetic suspension is emitted in multiple layers from several spirally distributed spray holes, forming a spiral ribbon-like liquid curtain covering the entire inner wall at the bottom of the blind hole. At the same time, when the magnetic suspension is ejected tangentially from the spray hole, it applies an asymmetrical tangential reaction force to the inner wall of the nozzle, driving the nozzle and the hollow rotating shaft to passively rotate around the outlet end of the liquid supply channel. This causes the spray pattern to continuously sweep and refresh at the bottom of the hole, eliminating the problems of local overspray accumulation and dry spots on the opposite side that are prone to occur in fixed spray holes. This ensures that the magnetic suspension adheres to the hole wall with a uniform thin liquid film, which is beneficial to improving the uniformity of spray coverage.

[0011] Preferably, when the nozzle is in the liquid spraying state, the two baffle assemblies are in the closed state; when the central camera is in the shooting state, the two baffle assemblies are in the open state.

[0012] In the above solution, the baffle assembly can be closed during the spraying stage to form a flow guiding and protective structure, preventing the magnetic suspension droplets from splashing or adhering to the lens surface of the central camera, thus avoiding lens contamination and blurred imaging; during the shooting stage, the baffle assembly can be opened to remove the obstruction of the field of view, ensuring that the central camera can capture a clear and complete image of the bottom of the blind hole; by switching between the two states, the operational requirements of high-pressure spraying are met, and the clarity of optical imaging is ensured, eliminating the cost of consumables such as frequent manual wiping of the lens or use of disposable protective covers.

[0013] Preferably, a camera ring is embedded in the outer wall of the central column. The camera ring includes several miniature imaging modules embedded in the outer wall of the central column in a circular array. The optical main axis of each camera is inclined towards the front of the probe, and the angle between the main axis of the central column and the main axis is between 20° and 40°.

[0014] In the above scheme, the camera ring can collect the circumferential magnetic powder distribution of the hole wall in the corresponding area of ​​the excitation component, forming a two-dimensional imaging coverage of axial bottom view + circumferential ring with the central camera at the front end. This allows the magnetic powder stripes of transverse cracks and circumferential defects to be captured in a fully expanded form, improving the sensitivity and accuracy of defect identification and providing complete input data for subsequent automatic image algorithm defect classification. At the same time, the embedded layout does not increase the outer diameter of the probe, and can adapt to the flaw detection requirements of small-diameter deep holes.

[0015] Each camera is tilted so that its field of view is focused on the annular magnetized sensitive area of ​​the hole wall to be tested after the front spray, without being blocked by the open guide petals.

[0016] Preferably, the baffle assembly includes an arc-shaped baffle, one end of which is fixedly connected to a connecting block, the connecting block being rotatably connected to a nozzle, and an electric push rod hinged to the inner wall of the arc-shaped baffle, the end of the electric push rod away from the arc-shaped baffle being hinged to the outer wall of the nozzle.

[0017] In the above solution, the arc-shaped baffle can be driven to rotate around the hinge axis of the connecting block by the extension and retraction of the electric push rod, realizing the rapid switching between closed protection and open viewing state. The control method is simple and reliable, allowing the same workstation to simultaneously accommodate the two conflicting functional requirements of high-pressure spraying and precision optical imaging. The smooth arc shape of the arc-shaped baffle can guide the flow along the direction of liquid flow in the closed state, reducing the occurrence of stagnant water zones and preventing magnetic suspension liquid from accumulating and dripping at the baffle to contaminate the lens, further improving the protective effect.

[0018] Preferably, the elastic petal module includes a support fixedly connected to the outer wall of the central column, a guide petal rotatably connected to the outer side of the support, and an elastic connector that applies elastic force to the guide petal on the inner side of the support.

[0019] In the above scheme, the guide petals open outward under the drive of the elastic connector, and the corrugated elastic ring stretches synchronously with the opening and closing of the guide petals to form a complete and closed annular liquid collection funnel.

[0020] Preferably, the elastic connector includes a sleeve rotatably connected to the inner wall of the support, one end of the sleeve is inserted with a rod, the end of the rod away from the sleeve is hinged to the middle of the guide petals, a slider is slidably connected to the inner side of the sleeve, one side of the slider is fixedly connected to the rod, and a compression spring is sleeved on the inner side of the sleeve, with both ends of the compression spring abutting against the slider and the inner wall of the sleeve, respectively.

[0021] In the above scheme, the compression spring applies a constant radial elastic force to the guide petals through the transmission chain of the slider and the insertion rod, so that the guide petals can automatically adjust the opening angle according to the change of the aperture. Faced with the unavoidable non-roundness of the inner wall of the deep hole due to casting tolerance, taper, and local expansion and contraction, the guide petals can automatically compensate and fit tightly. It will not cause the probe to jam due to rigid support, nor will it cause residual liquid leakage due to poor fit. It can adapt to the deep hole detection needs of different inner diameters and tapers. At the same time, the guide petals can scrape the hole wall simultaneously during the probe's advance and retreat, removing residual magnetic suspension and impurities, and achieving hole wall cleaning while performing flaw detection.

[0022] Preferably, the corrugated elastic ring is formed by the inner surfaces of multiple guide petals being fixedly connected together. The corrugated elastic ring is an elastic support with circumferential corrugations or folds. The corrugated elastic ring unfolds and is tensioned on the inner wall of the deep hole as the guide petals open, and folds and contracts as the guide petals close, so as to form a complete annular collection surface after the guide petals open to fully collect residual liquid.

[0023] In the above scheme, the circumferential corrugated or pleated structure provides the corrugated elastic ring with sufficient redundant stretching. When the guide petals open, the corrugation can absorb the circumferential displacement, preventing the ring from tearing due to excessive stretching or stress relaxation, thus ensuring the long-term stability of the sealing structure. The corrugated elastic ring stretches or contracts synchronously with the opening and closing of the guide petals, so that after all the guide petals open, a continuous and complete annular liquid collection funnel is formed, improving the collection efficiency of residual liquid.

[0024] Simultaneously, when the probe moves axially or experiences slight operational vibrations, the corrugated elastic ring will generate micro-elastic vibrations, causing the residual liquid adhering to the ring surface to flow inward in a directional manner. This, combined with the overall conical liquid collection structure, accelerates the flow of residual liquid into the drainage trough, ultimately ensuring precise drainage into the return trough for recycling. This effectively prevents residual liquid from accumulating on the ring surface, reduces the risk of residual liquid leaking backward and contaminating the undetected inner wall, and further improves the efficiency and reliability of closed-loop residual liquid recycling.

[0025] Preferably, the outer edge of the corrugated elastic ring is provided with an elastic sealing lip, which is made of an elastomer material and has a thickness greater than the body thickness of the corrugated elastic ring.

[0026] In the above scheme, the thicker elastic sealing lip can generate a greater amount of elastic deformation under radial extrusion force, forming a wide interference contact band for smooth inner walls, resulting in better sealing effect; for inner walls with helical rifling or annular grooves, the elastic sealing lip can be pressed into the groove under the combined action of its own elasticity and radial thrust, forming a conformal filling sealing effect, blocking the path of residual liquid leakage backward along the gap between the edge and the inner wall, and adapting to more types of deep hole inner wall flaw detection needs.

[0027] Meanwhile, the corrugated elastic ring with circumferential corrugation structure can form a buffer layer with elastic damping between the guide petals and the inner wall of the deep hole. The radial supporting force of the guide petals is gradually buffered and dissipated by the corrugated structure, and then evenly applied to the hole wall through the elastic sealing lip. This can absorb the radial movement and impact force generated during the probe's advance and retreat, reduce the hard force transmission between the rigid structure and the hole wall, and avoid secondary damage such as scratches and indentations on the high-precision inner surface, thus forming a reliable flexible protection for the precision-machined inner wall of the deep hole.

[0028] In addition, the elastic sealing lip made of elastomer material is soft and can evenly distribute the radial support force of the guide petals on the contact surface of the hole wall, avoiding local stress concentration at the edge of the rigid petals that could damage the thin-walled hole wall; when the probe moves axially, the elastic sealing lip can form a flexible scraping edge, removing residual magnetic suspension and fine impurities without damaging the inner wall surface, thus achieving both cleaning effect and inner wall protection.

[0029] Preferably, multiple groups of guide petals evenly distributed in a circular array together constitute a multi-support radial elastic support structure, forming a stable circumferential support for the central column.

[0030] In the above scheme, the guide petals form a multi-point radial elastic support when they are attached to the hole wall, which effectively counteracts the radial shaking and positional displacement generated during the probe operation, ensures that the circumferential distance between the camera ring and the hole wall to be inspected is consistent, eliminates the problems of imaging blur and field of view displacement caused by probe shaking and eccentricity, and improves the shooting accuracy of circumferential magnetic particle images and the accuracy of defect identification.

[0031] The beneficial effects of this invention are as follows: 1. This invention creates a spiral groove and spirally distributed spray holes on the inner wall of the nozzle, which causes the magnetic suspension to form a swirling pressurization when it flows through. The fluid reaction force drives the nozzle to rotate, achieving a spiral band-like coverage of the magnetic suspension on the inner wall of the blind hole without dead angles. This solves the problems of local overspray accumulation and dry spots caused by traditional unidirectional spraying, ensuring that the magnetic suspension adheres to the hole wall in a uniform thin film, while saving the amount of magnetic suspension used.

[0032] 2. This invention uses an elastic connector with a compression spring to drive the guide petals, allowing them to automatically adjust their opening angle according to changes in the aperture. Combined with a corrugated elastic ring, this forms a completely closed liquid collection funnel, solving the problem of residual liquid leakage caused by the rigid structure of traditional probes easily jamming or poor fit. It adapts to deep holes with different inner diameters, roundness, and taper, improving the residual liquid collection rate. With a backward-moving detection logic from deep to shallow, the corrugated elastic ring can completely stop the residual liquid flowing towards the aperture, preventing waste magnetic suspension from contaminating the undetected inner wall surface and ensuring a clean and interference-free magnetic background for subsequent detection stations. This effectively prevents waste magnetic suspension from contaminating undetected areas. Simultaneously, the guide petals can scrape the aperture wall during probe advance and retreat, removing residual magnetic suspension and impurities, achieving aperture wall cleaning during flaw detection.

[0033] 3. This invention integrates a front-end central camera and a camera ring embedded in the outer wall of the central column. It respectively acquires the axial image of the bottom of the blind hole and the circumferential ring magnetic powder distribution image of the corresponding area of ​​the excitation component, forming a two-dimensional imaging coverage of axial bottom view + circumferential ring. This solves the limitation of blind zone of single camera view, and allows the magnetic powder stripes of transverse cracks and circumferential defects to be captured in a fully expanded form, improving the recognition sensitivity and providing complete input data for defect classification of subsequent automatic image algorithms. At the same time, the circumferential elastic support formed by the guide petals can stabilize the probe posture, ensure the constant distance between the camera ring and the hole wall, eliminate imaging distortion caused by jitter and eccentricity, and further improve the shooting accuracy of circumferential imaging.

[0034] 4. This invention uses an electric push rod to drive the arc-shaped baffle to switch between closed protection and open viewing states: during the spraying stage, the baffle closes to form an arc-shaped guide shroud, blocking magnetic suspension droplets from contaminating the lens; during the shooting stage, the baffle opens to remove the obstruction, ensuring that the central camera obtains an unobstructed field of view. This solves the problem of conflict between high-pressure spraying and precision optical imaging functions. The central camera only needs to open the window intermittently to complete the acquisition, which helps to reduce image distortion and eliminates the cost of consumables such as frequent manual wiping or disposable lens caps. Attached Figure Description

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] Figure 1 This is a schematic diagram of the structure of a magnetic particle inspection probe for deep hole internal wall inspection according to the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a magnetic particle inspection probe for deep hole internal wall inspection according to the present invention. Figure 2 ; Figure 3 This is an anatomical diagram of a magnetic particle inspection probe for deep hole internal wall inspection according to the present invention. Figure 4 This is a cross-sectional view of the central column of the present invention; Figure 5 This is a schematic diagram of the nozzle module of the present invention; Figure 6 This is a schematic diagram of the baffle assembly of the present invention; Figure 7 This is a schematic diagram of the elastic petal module of the present invention; Figure 8 This is a schematic diagram of the structure of the elastic connector of the present invention; Figure 9 This is a schematic diagram of the unfolded state of the corrugated elastic ring of the present invention; Figure 10 This is a schematic diagram of the structure of a single flow-guiding petal of the present invention.

[0037] In the diagram: 1. Central column; 11. Liquid supply channel; 12. Negative pressure reflux chamber; 13. Negative pressure interface; 14. Excitation assembly; 15. Reflux groove; 16. Camera ring; 2. Nozzle module; 21. Nozzle; 22. Hollow rotating shaft; 23. Spiral groove; 24. Spray hole; 25. Central camera; 26. Baffle assembly; 261. Arc baffle; 262. Connecting block; 263. Electric push rod; 3. Elastic petal module; 31. Support; 32. Guide petal; 33. Drainage groove; 34. Elastic connector; 341. Sleeve; 342. Insert rod; 343. Slider; 344. Compression spring; 4. Corrugated elastic ring; 41. Elastic sealing lip. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] In this invention, the front end refers to the end of the probe that faces the bottom of the hole when it is inserted into the deep hole, and the rear end refers to the end that faces the opening / external control system.

[0040] like Figures 1 to 10 As shown in the figure, this embodiment proposes a magnetic particle inspection probe for deep hole inner wall inspection, including a central column 1. A liquid supply channel 11 for introducing magnetic suspension is opened at the center of the central column 1. An annular negative pressure return cavity 12 is opened inside the central column 1 near the outer periphery. A negative pressure interface 13 is opened at one end of the negative pressure return cavity 12. A negative pressure device is connected to the negative pressure interface 13 through a conduit. A magnetic suspension supply device is connected to the inlet end of the liquid supply channel 11 through a conduit.

[0041] An excitation assembly 14 is fixedly connected to the front end of the inner side of the central column 1. Several return channels 15 arranged in a circular array and communicating with the negative pressure return cavity 12 are opened on the outer side of the central column 1. A nozzle module 2 for uniformly spraying the magnetic suspension liquid in the liquid supply channel 11 is rotatably connected to the outlet end of the liquid supply channel 11. An elastic petal module 3 is movably connected to the front end of the outer side of the central column 1. The elastic petal module 3 includes several guide petals 32 arranged in a circular array. A guide channel 33 is opened on the inner side of the guide petal 32. The end position of the guide channel 33 corresponds to the opening position of the return channel 15. When the guide petal 32 is in the open state, the corrugated elastic ring 4 on the inner surface forms a continuous annular collection surface that can guide the residual liquid into the return channel 15.

[0042] In this embodiment, the magnetic suspension is pumped into the supply channel 11 by the magnetic suspension supply device. The magnetic suspension enters the nozzle module 2 through the outlet end of the supply channel 11. After forming a swirling flow through the spiral groove 23, it is evenly sprayed out from the spray hole 24 to the inner wall of the blind hole. The excitation component 14 generates a magnetic field when energized, causing magnetic powder to be adsorbed at the defects in the hole wall. The external negative pressure device maintains negative pressure in the negative pressure return chamber 12 through the negative pressure interface 13. After the guide petals 32 open, the corrugated elastic ring 4 on the inner surface forms a continuous annular collection surface, which guides the excess magnetic suspension and residual liquid into the diversion groove 33. The liquid is then drawn into the negative pressure return chamber 12 through the return groove 15 and finally discharged and recycled through the negative pressure interface 13. The central camera 25 captures the bottom image of the hole when the baffle component 26 opens, and the camera ring 16 simultaneously collects the circumferential magnetic powder distribution in the corresponding area of ​​the excitation component 14.

[0043] In this design, the swirling jet design of nozzle module 2 enables the magnetic suspension to form a seamless coverage on the orifice wall, avoiding local accumulation or missed spraying and ensuring consistent sensitivity of magnetic particle testing. The annular negative pressure structure of negative pressure return chamber 12 and return groove 15 enables directional recovery of residual liquid, improving the collection rate and preventing magnetic suspension from contaminating untested areas. At the same time, recovering the magnetic suspension reduces consumable costs. The elastic petal module 3 provides radial adaptive elasticity, and the guide petals 32 can automatically adjust the opening angle according to the orifice diameter change to adapt to deep holes with different inner diameters, avoiding jamming or poor fit. The arc-shaped baffle 261 of baffle assembly 26 closes to protect the central camera 25 during liquid spraying and opens during shooting to ensure a clear field of view.

[0044] As a specific embodiment of the present invention, refer to Figure 5The nozzle module 2 includes a nozzle 21. A hollow rotating shaft 22 is fixedly connected to one end of the nozzle 21. The inlet end of the hollow rotating shaft 22 is rotatably connected to the inner wall of the liquid supply channel 11 and communicates with the inside of the liquid supply channel 11. A spiral groove 23 is opened on the inner wall of the nozzle 21. Several spirally distributed spray holes 24 are opened on the side wall of the nozzle 21. The hole axis of the spray holes 24 is radially offset relative to the nozzle 21 and arranged tangentially along the spiral groove 23. A central camera 25 for capturing the bottom of the blind hole is fixedly connected to the front end of the nozzle 21. Two baffle assemblies 26 are movably connected to the outer wall of the nozzle 21 and are symmetrically distributed along the center line of the nozzle 21. When the nozzle 21 is spraying liquid, the two baffle assemblies 26 are in a closed state; when the central camera 25 is capturing images, the two baffle assemblies 26 are in an open state.

[0045] In this embodiment, after the magnetic suspension liquid supply device pumps the magnetic suspension liquid into the supply channel 11, the magnetic suspension liquid enters the nozzle 21 through the hollow rotating shaft 22. When flowing through the spiral groove 23 on the inner wall of the nozzle 21, the flow direction of the liquid is forcibly rewritten to tangential motion along the spiral line, generating a continuously rotating swirling pressurization component. The rotating magnetic suspension liquid is emitted in multiple layers from several spirally distributed spray holes 24 on the side wall, forming a spiral ribbon-like liquid curtain covering the entire inner wall at the bottom of the blind hole, ensuring that the magnetic suspension liquid wets the inspection area at the bottom of the hole without dead angles. At the same time, when the magnetic suspension liquid is tangentially ejected from the spray hole 24, it applies an asymmetrical tangential reaction force to the inner wall of the nozzle 21. The resultant torque of this reaction force drives the nozzle 21 together with the hollow rotating shaft 22 to passively rotate around the outlet end of the supply channel 11, so that the spray pattern is continuously swept and refreshed at the bottom of the hole, further enhancing the uniformity of coverage.

[0046] The spiral groove 23 of this design transforms ordinary axial laminar flow into swirling flow with circumferential velocity. Without the need for external driving components, it naturally achieves the rotational uniformity of nozzle 21 by utilizing the fluid reaction torque, eliminating the problems of local overspray accumulation and side leakage dry spots that are prone to occur in fixed nozzles. The swirling pressurization effect also slightly increases the outlet range and spreading tension, allowing the magnetic suspension to adhere to the vertical or inverted deep hole wall as a thinner, more uniform liquid film.

[0047] As a specific embodiment of the present invention, refer to Figure 4 A camera ring 16 is embedded in the outer wall of the central column 1. The camera ring 16 is set in a forward tilted position, and its field of view points to the circumferential hole wall detection zone corresponding to the excitation component 14.

[0048] In this embodiment, after the probe is positioned against the wall and the guide petals 32 are opened and stabilized, the central camera 25 captures the axial image of the bottom of the hole from the front view direction. At the same time, the camera ring 16, which is embedded in the outer wall of the central column 1 and corresponds to the circumferential position of the excitation component 14, provides a lateral / oblique circumferential field of view for the same transverse circumferential ...

[0049] This design overcomes the limitations of existing technologies where the front-end center camera 25 can only capture images from above or directly in front, resulting in blind spots. The side-view information provided by the camera ring 16 allows the magnetic powder stripes of such defects to be captured in a fully expanded form, improving recognition sensitivity. The embedded layout does not increase the outer diameter of the probe, but achieves dimensional expansion of visual information within the limited internal space, providing complete input data for subsequent automatic image algorithm defect classification.

[0050] The camera ring 16 contains several miniature imaging modules embedded in the outer wall of the central column 1 in a circular array. The optical main axis of each camera is tilted towards the front of the probe, and the angle between it and the main axis of the central column 1 is precisely limited to 20° to 40°, so that its field of view is focused on the annular magnetized sensitive area of ​​the hole wall to be tested after the front spray, and is not blocked by the open guide petals 32.

[0051] The central camera 25 is equipped with illumination sources around its periphery and the imaging side of the camera ring 16, which are used to provide uniform illumination for the area of ​​the hole wall and bottom to be inspected, thereby improving the imaging contrast and recognition clarity of the magnetic traces of defects.

[0052] As a specific embodiment of the present invention, refer to Figure 6 The baffle assembly 26 includes an arc-shaped baffle 261. A connecting block 262 is fixedly connected to one end of the arc-shaped baffle 261. The connecting block 262 is rotatably connected to the nozzle 21. An electric push rod 263 is hinged to the inner wall of the arc-shaped baffle 261. The end of the electric push rod 263 away from the arc-shaped baffle 261 is hinged to the outer wall of the nozzle 21.

[0053] In this embodiment, during the magnetic suspension spraying state, the electric push rod 263 is in its retracted stroke, pulling the arc-shaped baffle 261 inward around the hinge axis of the connecting block 262. The two arc-shaped baffles 261 are spliced ​​together to form a complete arc-shaped cover that is fastened to the front end of the nozzle 21. Its smooth arc shape guides the flow along the liquid flow direction without producing obvious stagnant water areas. At the same time, it shields the central camera 25 on the leeward side, preventing magnetic suspension droplets from splashing or dripping and directly adhering to the lens surface. When the spraying is completed and the bottom image of the hole needs to be captured in this detection step, the electric push rod 263 extends and pushes the arc-shaped baffle 261 to open outward, removing the mechanical obstruction of the field of view in front of the central camera 25. The central camera 25 obtains an unobstructed direct field of view to capture the image of magnetic powder accumulation at the bottom of the blind hole. Before the probe begins to retract after the image is captured, the baffle assembly 26 closes and locks again, protecting the central camera 25 from secondary contamination throughout the retraction process when passing through the wet wall area.

[0054] The closed protection-opening hard switching logic driven by the electric push rod 263 in this design enables the same workstation to simultaneously meet the two contradictory functional requirements of high-pressure spraying and precision optical imaging. The central camera 25 only needs to open the window intermittently to complete the acquisition during the entire round trip operation, eliminating the cost of consumables such as frequent manual wiping or disposable lens caps.

[0055] The aforementioned structure of the central camera 25 with the protection of the openable and closable arc-shaped baffle 261 can be adapted to both blind holes and through holes, which are deep holes to be inspected, without the need to modify the probe body structure.

[0056] In blind hole inspection, the central camera 25 faces the bottom end face of the blind hole and can completely capture the axial defect distribution image of the bottom end face of the hole. Together with the circumferential camera ring 16, it can achieve full coverage inspection of the bottom end face of the hole and the hole wall ring.

[0057] In through-hole inspection, the working mode can be flexibly switched according to the inspection requirements: when only defects on the inner wall of the through hole need to be inspected, the central camera 25 remains in a non-working state, the arc baffle 261 is closed throughout to protect the lens, and the continuous scanning of the entire inner wall of the hole is completed solely by the circumferentially arranged camera ring 16, minimizing the risk of magnetic suspension contamination; when defects on both ends of the through hole need to be inspected simultaneously, the arc baffle 261 opens when the probe reaches the end of the through hole, the central camera 25 acquires the axial image of the end face, and the middle inner wall section is still inspected independently by the camera ring 16; the two hole types share the same probe main structure, improving the versatility and applicability of the working conditions, and reducing the equipment investment cost for different hole types.

[0058] The power supply and signal cables of the excitation assembly 14, camera ring 16, central camera 25 and electric push rod 263 are led out through the axial sealed wiring hole opened inside the central column 1 to the tail of the probe, and connected to the external control and image acquisition system through the sealed electrical connector.

[0059] As a specific embodiment of the present invention, refer to Figures 1 to 4 , Figures 7 to 10 The elastic petal module 3 includes a support 31 fixedly connected to the outer wall of the central column 1. A flow guide petal 32 is rotatably connected to the outer side of the support 31. A flow guide groove 33 is opened on the inner side of the flow guide petal 32. The end position of the flow guide groove 33 corresponds to the opening position of the return groove 15. A circumferentially continuous corrugated elastic ring 4 is fixedly connected to the inner surface of multiple flow guide petals 32. The corrugated elastic ring 4 is an elastic support with circumferential corrugations or pleats. An elastic sealing lip 41 is fixedly provided on the outer edge of the corrugated elastic ring 4 (i.e., the side close to the inner wall of the deep hole). The elastic sealing lip 41 is made of an elastomer material (such as fluororubber, silicone rubber or polyurethane rubber) with a hardness range of 50HA to 80HA, and its thickness is greater than the body thickness of the corrugated elastic ring 4 to provide sufficient compression deformation allowance.

[0060] An elastic connector 34 is provided on the inner side of the support 31 to apply elastic force to the guide petals 32. The elastic connector 34 includes a sleeve 341 that is rotatably connected to the inner wall of the support 31. One end of the sleeve 341 is inserted with a rod 342. The end of the rod 342 away from the sleeve 341 is hinged to the middle of the guide petals 32. A slider 343 is slidably connected to the inner side of the sleeve 341. One side of the slider 343 is fixedly connected to the rod 342. A compression spring 344 is sleeved on the inner side of the sleeve 341. The two ends of the compression spring 344 abut against the slider 343 and the inner wall of the sleeve 341, respectively. In this embodiment, it should be noted that, Figures 1 to 4 The corrugated elastic ring 4 is shown as partially disconnected or separated. This is only a partial omission in the drawing to make it easier to clearly show the internal structure of the guide petals 32, and is not a limitation on the actual structure of the corrugated elastic ring 4.

[0061] The corrugated elastic ring 4 is not an ordinary soft film, but an accordion-style elastic support ring with circumferential corrugations or pleats. Its corrugations extend continuously along the circumference of the central column 1. This corrugated structure provides sufficient folding and expansion margin in the circumferential direction, so that the corrugated elastic ring 4 can freely extend or retract with the opening and closing of the guide petals 32. At the same time, the corrugated structure provides sufficient support stiffness in the radial direction from the central column 1 to the inner wall of the deep hole, so that the corrugated elastic ring 4 itself has the ability to resist pressure and transmit force.

[0062] In actual working conditions (such as) Figure 9 As shown, when the guide petals 32 open and adhere to the inner wall of the blind hole under the drive of the elastic connector 34, the corrugated elastic ring 4 on its inner surface is stretched and unfolded accordingly, and its edge is tightly attached to the inner wall, filling the circumferential gap between the probe and the inner wall of the deep hole, forming a continuous and complete annular liquid collection surface.

[0063] As the probe advances from the opening of the deep hole to the bottom, the outer edge of the corrugated elastic ring 4, fixed inside the guide petal 32, first contacts the inner wall of the deep hole. When the hole diameter is slightly smaller than the opening outer diameter of the guide petal 32, the hole wall applies a radial inward thrust to the elastic sealing lip 41, and through the corrugated elastic ring 4, drives the guide petal 32 to retract inward around the support 31. At this time, the insertion rod 342 is pushed into the sleeve 341, and the slider 343 slides along the inner wall of the sleeve 341 and compresses the compression spring 344 to accumulate elastic potential energy. When the probe continues to penetrate to the target detection section or the hole diameter expands locally to release the constraint, the compression spring 344 releases the accumulated rebound force, and through the transmission chain of the slider 343 and the insertion rod 342, pushes the guide petal 32 outward. The guide petal 32, as a supporting skeleton, expands the corrugated elastic ring 4 until the elastic sealing lip 41 is tightly pressed against the inner wall of the deep hole under constant elastic force.

[0064] During this process, the entire corrugated elastic ring 4 unfolds or folds synchronously with the opening and closing angle of the guide petals 32. The elastic sealing lip 41 on its outer edge always maintains dynamic sealing contact with the hole wall, forming a continuous and complete annular closed barrier. Because the corrugated elastic ring 4 has radial support stiffness, it helps to reduce the risk of collapse or rollover under the impact of high-pressure magnetic suspension spray and residual liquid flow. The drainage grooves 33 on the inner side of all guide petals 32 face the same direction to form a stable annular liquid collection funnel shape. Excess magnetic suspension and residual liquid flowing after flaw detection flow down the hole wall and are blocked by the elastic sealing lip 41 and the corrugated elastic ring 4. They cannot continue to contaminate the uninspected inner wall and instead flow into the drainage groove 33 and are guided along the groove to the precisely aligned return groove 15 opening at the end.

[0065] When the probe retracts to detect the inner wall of the deep hole, the guide petals 32 remain attached to the wall under the elastic force of the elastic connector 34, and the elastic sealing lip 41 on the outer edge of the corrugated elastic ring 4 is subjected to radial compression.

[0066] For smooth, grooveless inner walls, the elastic sealing lip 41 undergoes uniform elastic compression under positive pressure, and its outer surface forms a wide interference contact band with the smooth inner wall. The high resilience of the elastomer seals the gap between adjacent guide petals 32, preventing residual liquid from leaking along the petal splice seam.

[0067] For inner wall conditions with helical rifling or annular grooves, when the elastic sealing lip 41 moves to the position of the groove (corrugation) of the rifling, under the combined action of its own elastic restoring force and the continuous radial thrust provided by the compression spring 344, the thicker lip body undergoes directional shear deformation and is pressed into the groove, forming a filling and sealing effect similar to an elastic insert. When the elastic sealing lip 41 moves to the position of the protrusion of the rifling, it returns to the compression sealing state. Through the adaptive conformal deformation of the elastic sealing lip 41 on the uneven rifling surface, combined with the circumferential tension provided by the corrugated elastic ring 4, the corrugated elastic ring 4 can form a continuous and closed liquid collection surface in the entire circumference, regardless of whether there is a helical groove or annular groove on the inner wall. The elastic sealing lip 41 can prevent residual liquid from leaking backward along the gap between the edge and the inner wall, ensuring that the inner wall of the undetected area is not contaminated by the magnetic suspension liquid.

[0068] In this design, the elastic connector 34 provides the guide petals 32 with continuous radial conforming capability, and transmits the elastic force to the elastic sealing lip 41 through the corrugated elastic ring 4. This allows the elastic sealing lip 41 to adaptively fit the irregular contours of the inner wall of the deep hole to be tested, such as casting tolerances, taper, local expansion and contraction diameters, and rifling concavity and convexity. It will not cause the probe to jam due to rigid support, nor will it leak due to poor fit. At the same time, the elastic sealing lip 41 is made of elastomeric material, and its flexible contact with the hole wall can avoid rigid scraping damage to the high-precision inner surface. The precise alignment design of the ends of the drainage channel 33 and the return channel 15 transforms the disordered flow of waste liquid into a directional converging recovery flow, improving the residual liquid collection rate and effectively preventing the waste magnetic suspension from flowing towards the hole opening and contaminating the clean inner wall behind the guide petals 32 that has not been tested. Combined with the backward detection process from deep to shallow, it can ensure that the hole wall of each detection station is in a clean state before spraying, eliminating residual liquid background interference and improving the accuracy of defect identification.

[0069] Meanwhile, relying on the constant elastic force provided by the compression spring 344, the elastic sealing lip 41 continues to adhere tightly to the inner wall of the deep hole. When the probe moves forward and backward along the axial direction of the hole, the elastic sealing lip 41 can form a flexible scraping action on the surface of the hole wall, uniformly scraping away the residual magnetic suspension and trace impurities attached to the hole wall. The scraped residual liquid flows into the drainage groove 33 inside the guide petal 32 and is eventually recovered along with the residual liquid. The hole wall is cleaned while the flaw detection operation is performed, avoiding interference with subsequent detection after the residual magnetic suspension dries. Moreover, the flexible scraping can effectively reduce scratches or pressure damage to the precision inner wall.

[0070] Moreover, multiple sets of evenly distributed guide petals 32 in a circular array together form a multi-point radial elastic support structure. Together with the flexible contact layer formed by the corrugated elastic ring 4 and the elastic sealing lip 41, it can form a stable and buffering circumferential support for the central column 1, effectively offsetting the radial shaking and positional displacement generated during probe operation, ensuring that the circumferential distance between the camera ring 16 and the wall of the hole to be inspected remains consistent, eliminating imaging blur and field of view displacement caused by probe shaking and eccentricity, and improving the shooting accuracy of circumferential magnetic particle images and the accuracy of defect identification.

[0071] In addition, the corrugated elastic ring 4 and the elastic sealing lip 41 together form a flexible contact layer on the outer periphery of the probe, which can isolate the rigid structure such as the guide petals 32 from direct hard contact with the inner wall of the deep hole. It provides elastic buffer when the probe experiences radial shaking, eccentricity, or jamming, avoiding the rigid structure from scraping or bumping against the high-precision inner surface and preventing secondary damage such as scratches and indentations on the hole wall. The uniform surface contact form can also disperse the radial support stress, avoiding excessive local stress that could cause plastic deformation of the thin-walled deep hole component. While achieving the function of sealing and collecting liquid, it also effectively protects the inner wall of the deep hole.

[0072] When the probe moves axially or experiences slight operational vibrations, the circumferential corrugated structure will simultaneously generate micro-elastic vibrations, causing the residual liquid adhering to the annular surface to flow inward in a directional manner. This, combined with the overall conical liquid collection structure, accelerates the flow of residual liquid into the drainage trough 33, and finally accurately flows into the return trough 15 to complete the recovery. This effectively avoids the residual liquid from accumulating on the annular surface, reduces the risk of residual liquid leaking backward and contaminating the undetected inner wall, and further improves the efficiency and reliability of the closed-loop recovery of residual liquid.

[0073] Overall workflow: First, aim the probe at the deep hole to be tested (such as the bore of a cannonball), and quickly advance it from the hole opening to the bottom of the hole without load. The external magnetic suspension fluid supply device is connected to the inlet of the supply channel 11 through a conduit, and the external negative pressure device is connected to the negative pressure interface 13 through a conduit.

[0074] During the propulsion process, the elastic sealing lip 41 first contacts the hole wall. When the hole diameter is smaller than the outer diameter of the guide petals 32, the hole wall applies a radial inward thrust to the elastic sealing lip 41. This thrust is transmitted to the guide petals 32 through the corrugated elastic ring 4, forcing the guide petals 32 to retract inward around the support 31. The insertion rod 342 is pushed into the sleeve 341, and the slider 343 compresses the compression spring 344 to accumulate elastic force. During this unloaded propulsion stage, the spraying and magnetization operations are not started to avoid the magnetic suspension liquid from contaminating the inner wall in advance.

[0075] After the probe is pushed to the deepest point at the bottom of the blind hole, it stops advancing. The compression spring 344 releases its rebound force, and the guide petals 32 are pushed outward through the transmission chain of the slider 343 and the insertion rod 342. The guide petals 32 act as a support skeleton to open the corrugated elastic ring 4. The corrugated elastic ring 4 drives the elastic sealing lip 41 on its outer edge to unfold outward until the elastic sealing lip 41 is tightly attached to the hole wall under constant elastic force, forming a complete annular liquid collection sealing surface. At this time, the excitation and magnetic suspension spraying steps are performed (same as the subsequent inner wall inspection). Then the electric push rod 263 extends and pushes the arc baffle 261 to open. After the light is applied, the central camera 25 first acquires the axial defect image of the bottom end face of the blind hole to complete the bottom inspection of the hole.

[0076] The probe then employs a backward-retreating operation mode, moving from deep to shallow, and pauses at each target inspection section. The single-station flaw detection operation is completed by following these steps: In the first step, after the workstation is positioned, the compression spring 344 continuously transmits elastic force to the elastic sealing lip 41 through the guide petals 32 and the corrugated elastic ring 4, so that the elastic sealing lip 41 always remains in contact with the hole wall, forming a stable circumferential seal and an annular liquid collection barrier.

[0077] The second step involves the electric push rod 263 retracting, pulling the arc-shaped baffle 261 to close and protect the lens of the central camera 25.

[0078] The third step is to start the magnetic suspension supply equipment. The magnetic suspension enters the nozzle 21 through the supply channel 11, flows through the spiral groove 23 to form a swirling pressurization, and is sprayed out from the spirally distributed spray holes 24 to form a spiral ribbon-shaped uniform liquid curtain on the hole wall of the current station. At the same time, the excitation component 14 is energized to generate a circumferential magnetic field, which causes magnetic powder to be adsorbed at the defects of the hole wall to form magnetic traces.

[0079] In the fourth step, the excess magnetic suspension and residual liquid flowing after flaw detection flow along the hole wall towards the hole opening. They are blocked by the elastic sealing lip 41 and the corrugated elastic ring 4, preventing them from continuing to contaminate the undetected inner wall. Instead, they flow into the drainage groove 33 inside the guide petal 32 and enter the negative pressure return chamber 12 through the precisely aligned return groove 15 at the end. An external negative pressure device draws out the residual liquid through the negative pressure interface 13, achieving closed-loop recycling. During this process, the residual liquid is stopped on the side of the elastic sealing lip 41 near the bottom of the hole and will not contaminate the undetected inner wall behind the elastic sealing lip 41.

[0080] In the fifth step, after spraying and magnetization are completed, the electric push rod 263 extends again, pushing the arc baffle 261 to open. The camera ring 16, which is embedded in the outer wall of the central column 1 and corresponds to the position of the excitation component 14, collects the circumferential ring magnetic powder distribution image of the hole wall at the current workstation.

[0081] After completing the inspection at the current workstation, the probe continues to retreat towards the borehole to the next inspection section, repeating steps one through five until all workstations in the borehole are inspected. After all inspections are completed, the baffle assembly 26 closes again to protect the central camera 25, the probe exits from the borehole, the elastic petal module 3 automatically opens and resets after losing the constraint of the borehole wall, and the elastic sealing lip 41 detaches from the borehole wall, completing a single inspection.

[0082] It should be noted that when the workpiece to be inspected is a through hole, after the probe is inserted, it is quickly advanced to the end without load. Then, the same backward operation mode from deep to shallow is used to inspect each station. If only the defects of the inner wall of the through hole need to be inspected, the central camera 25 remains in a non-working state, and the arc baffle 261 is closed to protect the lens throughout the process. Only the camera ring 16 completes the continuous circumferential scanning of the entire inner wall of the hole. If the defects of the end face of the through hole need to be inspected at the same time, when the probe moves to the end position of the through hole, the arc baffle 261 opens, and the central camera 25 acquires the axial image of the end face. The middle inner wall section is still inspected independently by the camera ring 16. The whole inspection process is compatible with blind hole inspection and does not require adjustment of the core structure of the probe, thus improving practicality and scene adaptability.

[0083] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnetic particle inspection probe for deep hole internal wall flaw detection, comprising a central column (1), characterized in that, The central column (1) has a supply channel (11) for introducing magnetic suspension fluid at its center. A ring-shaped negative pressure return cavity (12) is located near the outer periphery inside the central column (1). An excitation assembly (14) is fixedly connected to the front end of the inner side of the central column (1). Several return grooves (15) arranged in a circular array and communicating with the negative pressure return cavity (12) are located on the outer side of the central column (1). A negative pressure interface (13) is located at one end of the negative pressure return cavity (12) and connected to a negative pressure device. The outlet end of the supply channel (11) is rotatably connected to a useful... The nozzle module (2) that uniformly sprays the magnetic suspension liquid in the liquid supply channel (11) has an elastic petal module (3) movably connected to the front end of the outer side of the central column (1). The elastic petal module (3) includes a number of guide petals (32) arranged in a circular array. The inner side of the guide petal (32) is provided with a diversion groove (33). The end position of the diversion groove (33) corresponds to the opening position of the return groove (15). When the guide petal (32) is open, the corrugated elastic ring (4) on the inner surface forms a continuous annular collection surface to guide the residual liquid into the return groove (15).

2. The magnetic particle inspection probe for deep hole internal wall inspection according to claim 1, characterized in that, The nozzle module (2) includes a nozzle (21), one end of which is fixedly connected to a hollow rotating shaft (22). The inlet end of the hollow rotating shaft (22) is rotatably connected to the inner wall of the liquid supply channel (11) and communicates with the inside of the liquid supply channel (11). The inner wall of the nozzle (21) is provided with a spiral groove (23). The side wall of the nozzle (21) is provided with a plurality of spirally distributed spray holes (24). The hole axis of the spray hole (24) is radially offset relative to the nozzle (21) and arranged tangentially along the spiral groove (23). The front end of the nozzle (21) is fixedly connected to a central camera (25) for capturing the bottom of the blind hole. The outer wall of the nozzle (21) is movably connected to two baffle assemblies (26) symmetrically distributed along the center line of the nozzle (21).

3. A magnetic particle inspection probe for deep hole internal wall flaw detection according to claim 2, characterized in that, When the nozzle (21) is in the liquid spraying state, the two baffle assemblies (26) are in the closed state; when the central camera (25) is in the shooting state, the two baffle assemblies (26) are in the open state.

4. A magnetic particle inspection probe for deep hole internal wall flaw detection according to claim 3, characterized in that, The outer wall of the central column (1) is embedded with a camera ring (16). The camera ring (16) includes several miniature imaging modules that are embedded in the outer wall of the central column (1) in a circular array. The optical main axis of each camera is tilted towards the front of the probe, and the angle between the main axis of the central column (1) and the main axis is between 20° and 40°.

5. A magnetic particle inspection probe for deep hole internal wall inspection according to claim 3, characterized in that, The baffle assembly (26) includes an arc-shaped baffle (261), one end of which is fixedly connected to a connecting block (262), the connecting block (262) being rotatably connected to the nozzle (21), and an electric push rod (263) being hinged to the inner wall of the arc-shaped baffle (261), the end of the electric push rod (263) away from the arc-shaped baffle (261) being hinged to the outer wall of the nozzle (21).

6. A magnetic particle inspection probe for deep hole internal wall inspection according to claim 1, characterized in that, The elastic petal module (3) includes a support (31) fixedly connected to the outer wall of the central column (1), a guide petal (32) is rotatably connected to the outside of the support (31), and an elastic connector (34) is provided on the inside of the support (31) to apply elastic force to the guide petal (32).

7. A magnetic particle inspection probe for deep hole internal wall inspection according to claim 6, characterized in that, The elastic connector (34) includes a sleeve (341) rotatably connected to the inner wall of the support (31). One end of the sleeve (341) is inserted with a rod (342). The end of the rod (342) away from the sleeve (341) is hinged to the middle of the guide petal (32). A slider (343) is slidably connected to the inner side of the sleeve (341). One side of the slider (343) is fixedly connected to the rod (342). A compression spring (344) is sleeved on the inner side of the sleeve (341). The two ends of the compression spring (344) abut against the slider (343) and the inner wall of the sleeve (341), respectively.

8. A magnetic particle inspection probe for deep hole internal wall inspection according to claim 6, characterized in that, The corrugated elastic ring (4) is formed by the inner surfaces of multiple guide petals (32) being fixedly connected together. The corrugated elastic ring (4) is an elastic support with circumferential corrugations or folds. The corrugated elastic ring (4) unfolds and is tensioned on the inner wall of the deep hole as the guide petals (32) open, and folds and contracts as the guide petals (32) close, so as to form a complete annular collection surface to collect residual liquid after the guide petals (32) open.

9. A magnetic particle inspection probe for deep hole internal wall inspection according to claim 8, characterized in that, The outer edge of the corrugated elastic ring (4) is provided with an elastic sealing lip (41), which is made of an elastomer material and its thickness is greater than the thickness of the corrugated elastic ring (4).

Images