Ultrasonic nondestructive testing system and method for internal defects of nitrogen spring cylinder body

Abstract

The invention relates to the technical field of ultrasonic detection, and discloses an ultrasonic nondestructive detection system and method for internal defects of a nitrogen spring cylinder. Accurate regulation and control of the smearing amount of the coupling agent are achieved, and dynamic adaptation of the smearing amount is achieved through the design that a large piston and a small piston on a pull rod are matched with an expansion cavity and a shrinkage cavity of a filler pipe, specifically, in the cylinder body side wall smearing stage, the large piston efficiently extrudes the coupling agent and cooperates with cylinder body rotation to ensure circumferential uniform covering, and the coupling foundation of ultrasonic propagation is guaranteed; when the coupling agent reaches the bottom of the cylinder body, the small piston is switched to be matched with the shrinkage cavity, the smearing amount is greatly reduced, the problem of excessive accumulation caused by natural sliding of the coupling agent at the bottom is solved, and defect misjudgment is avoided; by means of the design, it is guaranteed that the coupling agent content of each area meets the detection requirement, it is guaranteed that ultrasonic signal transmission is stable, the detection result is accurate, the using amount of the coupling agent is effectively saved, the detection cost is reduced, meanwhile, pollution of excessive coupling agents to equipment and a cylinder body is reduced, and the cleanliness and efficiency of the detection process are improved.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic testing technology, specifically, it relates to an ultrasonic non-destructive testing system and method for internal defects of nitrogen spring cylinders. Background Technology

[0002] Nitrogen springs, as high-precision elastic elements, are widely used in high-end equipment fields such as automobile manufacturing, aerospace, and precision molds due to their advantages of stable output force, fast response speed, and long service life. The nitrogen spring cylinder body, as a core load-bearing component, directly determines the working performance and operational safety of the nitrogen spring. If defects such as cracks, porosity, or inclusions exist inside the cylinder body, it is highly susceptible to rupture, leakage, and other serious failures under high-pressure nitrogen, leading to equipment downtime or even safety accidents. Therefore, accurate and efficient internal defect detection of nitrogen spring cylinder bodies is a crucial step in ensuring the quality of equipment manufacturing.

[0003] Ultrasonic nondestructive testing (NDT) technology has become one of the mainstream technologies for detecting internal defects in metal components due to its high accuracy, strong penetration, and non-destructive nature. In the ultrasonic testing process, the role of the couplant is crucial. It fills the air gap between the probe and the workpiece surface, reducing energy loss during ultrasonic wave propagation and ensuring efficient penetration and effective reception of defect signals. For workpieces like nitrogen spring cylinders with curved inner walls and relatively closed structures, the uniformity and precision of couplant application directly affect the stability of the detection signal and the accuracy of defect identification.

[0004] Existing ultrasonic non-destructive testing equipment for nitrogen spring cylinders has found that during the couplant application process, sufficient couplant is needed on the cylinder sidewalls to ensure ultrasonic wave propagation. However, due to gravity, the couplant at the bottom of the cylinder tends to slide off and accumulate naturally. Applying a fixed amount of couplant at the bottom can lead to excessive couplant at the bottom, causing signal interference and resulting in misjudgment of defects. In view of this, the present invention is proposed. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows: An ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder includes a worktable, on which a tray is rotatably mounted, and a clamping assembly is provided on the tray for clamping the cylinder. A fixed plate is vertically slidably mounted on the worktable. Two pairs of applicator heads and ultrasonic testing probes are staggered on the fixed plate. A filler tube is also mounted on the worktable. The filler tube is filled with coupling agent. A pull rod is slidably mounted inside the filler tube, and the bottom of the pull rod is mounted on the fixed plate. A large piston and a small piston are vertically mounted on the pull rod. A shrinking cavity is opened on the filler tube, which is adapted to the small piston. An expansion cavity is opened on the side wall of the filler tube. When the fixed plate moves the pull rod downward, the large piston squeezes the coupling agent to apply it to the inner wall of the cylinder. When the applicator head moves to the bottom of the cylinder, the large piston slides inside the expansion cavity, and the small piston slides to connect with the shrinking cavity, reducing the amount of coupling agent. The fixed plate is equipped with a switching assembly including a synchronization arm, the two ends of which are rotatably connected to the applicator head and the ultrasonic detection probe, respectively, and the synchronization arm is in an inclined state.

[0006] In a preferred embodiment of the present invention, four support legs are installed at the bottom of the workbench, and pads are rotatably installed at the bottom of the four support legs. The pads are in the form of protrusions. A bracket is installed on the workbench. The bracket is arched. A controller is also installed on the workbench. A reinforcing rib is installed at the bent position of the bracket. The reinforcing rib is triangular.

[0007] In a preferred embodiment of the present invention, a shifting motor is installed on the workbench, the shifting motor is electrically connected to the controller, the output end of the shifting motor is connected to the tray, the clamping assembly includes three pairs of opposing sliding clamps, a slider is installed at the bottom of the clamp, the slider is slidably disposed in a groove opened on the tray, a fixing block is installed on the tray, a threaded rod is screwed onto the fixing block, and the end of the threaded rod is rotatably connected to the side wall of the clamp.

[0008] In a preferred embodiment of the present invention, a support plate is screwed onto the tray, the support plate is supported at the bottom of the cylinder, and the support plate is used to adjust the vertical position of the cylinder so that the end of the cylinder is in contact with the applicator head.

[0009] In a preferred embodiment of the present invention, a lifting electric push rod is installed on the bracket, and the lifting electric push rod is electrically connected to the controller. The output rod of the lifting electric push rod passes through the bracket, and an arched frame is installed at the end of the output rod of the lifting electric push rod. A fixing plate is installed at the bottom of the arched frame, and the outer shell of the packing tube is connected to the bracket.

[0010] In a preferred embodiment of the present invention, the coating head housing is equipped with a connecting pipe, the connecting pipe is rotatably connected to the synchronous arm, a flexible hose is installed at the end of the connecting pipe, the end of the flexible hose is connected to the filler tube, the filler tube has a filler port located below the large piston, and a cover plate is installed on the filler port by bolts.

[0011] In a preferred embodiment of the present invention, the controller is electrically connected to the ultrasonic detection probe. The ultrasonic detection probe housing is equipped with a synchronizing rod, which is rotatably connected to a synchronizing arm. A sliding plate is mounted on the synchronizing rod. A through groove is provided at the bottom of the fixing plate, which is slidably connected to the sliding plate. A sliding rod is installed through the sliding plate, with both ends of the sliding rod connected to the through groove. A limit spring is sleeved on the sliding rod, with one end of the limit spring engaged on the sliding plate and the other end engaged on the side wall of the through groove.

[0012] In a preferred embodiment of the present invention, a drive motor is mounted on the fixed plate, a synchronous shaft is mounted on the output rod of the drive motor, the end of the synchronous shaft passes through the fixed plate, a cam is mounted on the end of the synchronous shaft, a push rod is mounted on the side wall of the connecting pipe, a ball is mounted on the end of the push rod, and the side wall of the ball is slidably connected to the side wall of the cam.

[0013] In a preferred embodiment of the present invention, a sealing plug is slidably disposed inside the connecting tube. When the applicator head approaches the fixed plate, the sealing plug seals the end of the hose. An insert rod is installed on the sealing plug. The insert rod is movably inserted into the connecting tube. A fixed seat is installed at the end of the insert rod. The end of the fixed seat is installed on the fixed plate.

[0014] An ultrasonic non-destructive testing method for internal defects in a nitrogen spring cylinder body, comprising the following steps: Step 1: Place the cylinder to be tested on the tray, rotate the threaded rod of the fixing block, push the clamping plate along the slide groove to clamp the cylinder to achieve radial positioning, rotate the bearing plate to adjust the height of the cylinder so that its end fits the application head; Step 2: The controller commands the lifting electric push rod to move, which drives the arched frame, the fixing plate and the applicator head to extend into the cylinder. The fixing plate moves down and drives the pull rod to slide. The large piston squeezes the coupling agent through the hose to the applicator head. At the same time, the shifting motor drives the cylinder to rotate, so that the coupling agent is evenly covered in the circumference. When the applicator head reaches the bottom of the cylinder, the small piston cooperates with the shrinking cavity to reduce the amount of coupling agent squeezed out and prevent accumulation. Step 3: The controller controls the drive motor to run, which pushes the push rod through the synchronous shaft and cam, causing the coating head to retract. Through the synchronous arm linkage, the ultrasonic detection probe is made to fit against the inner wall of the cylinder, while the sealing plug seals the end of the hose.

[0015] Step 4: The controller adjusts the lifting electric push rod to drive the ultrasonic detection probe to scan up and down, and the synchronous shifting motor drives the cylinder to rotate, so as to achieve full-range detection without blind spots; Step 5: After the test is completed, the controller resets each component, and after adding coupling agent, the entire equipment is reset and ready for the next test.

[0016] Compared with the prior art, the present invention has the following advantages: This invention achieves precise control of the amount of coupling agent applied. Through the adaptive design of large and small pistons on the pull rod and the expansion and contraction cavities of the packing tube, the application amount is dynamically adjusted: During the application stage on the cylinder sidewall, the large piston efficiently squeezes the coupling agent, and the cylinder rotation ensures uniform circumferential coverage, guaranteeing the coupling foundation for ultrasonic propagation; upon reaching the bottom of the cylinder, the small piston and contraction cavity work together to significantly reduce the application amount, minimizing excessive accumulation at the bottom due to natural slippage of the coupling agent, and avoiding misjudgments of defects. This design ensures that the coupling agent content in each area is adapted to the testing requirements, guaranteeing stable ultrasonic signal transmission and accurate test results, while effectively saving coupling agent usage, reducing testing costs, and minimizing contamination of the equipment and cylinder by excessive coupling agent, thus improving the cleanliness and efficiency of the testing process.

[0017] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0018] In the attached diagram: Figure 1 A three-dimensional diagram of an ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder. Figure 2 A 3D diagram of the tray of an ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder; Figure 3 A local ultrasonic non-destructive testing system for internal defects of nitrogen spring cylinders Figure 1 ; Figure 4 A local ultrasonic non-destructive testing system for internal defects of nitrogen spring cylinders Figure 2 ; Figure 5 A cross-sectional view of the packing tube in an ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder. Figure 6 A bottom view of the mounting plate of an ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder. Figure 7 A local ultrasonic non-destructive testing system for internal defects of nitrogen spring cylinders Figure 3 ; Figure 8 This is a cross-sectional view of the fixed plate of an ultrasonic non-destructive testing system for internal defects in a nitrogen spring cylinder.

[0019] In the diagram: 1. Workbench; 11. Support leg; 111. Pad; 12. Controller; 13. Tray; 131. Shift motor; 132. Clamping plate; 133. Slider; 134. Slide groove; 135. Threaded rod; 136. Fixing block; 137. Bearing plate; 14. Bracket; 141. Reinforcing rib; 2. Fixed plate; 21. Lifting electric push rod; 211. Arched frame; 212. Protective cover; 22. Application head; 221. Connecting pipe; 222. Hose; 23. Filler tube; 231. Filler inlet; 232. Expansion cavity; 233. Reduction cavity; 24. Pull rod; 241. Large piston; 242. Small piston; 25. Ultrasonic detection probe; 251. Synchronizing rod; 252. Slide plate; 253. Through groove; 254. Slide rod; 255. Limiting spring; 3. Cam; 31. Drive motor; 311. Synchronous shaft; 32. Push rod; 321. Ball bearing; 322. Synchronous arm; 33. Sealing plug; 331. Insert rod; 332. Fixing seat. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention.

[0021] Example 1: like Figures 1 to 8 As shown, an ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder includes a worktable 1, a tray 13 rotatably mounted on the worktable 1, a clamping assembly on the tray 13, and the clamping assembly is used to clamp the cylinder. A fixed plate 2 is vertically slidably mounted on the workbench 1. Two pairs of applicator heads 22 and ultrasonic testing probes 25 are staggered on the fixed plate 2. A filler tube 23 is also mounted on the workbench 1. The filler tube 23 is filled with coupling agent. A pull rod 24 is slidably mounted inside the filler tube 23, and the bottom of the pull rod 24 is mounted on the fixed plate 2. A large piston 241 and a small piston 242 are vertically mounted on the pull rod 24. A shrinkage cavity 233 is opened on the filler tube 23. The shrinkage cavity 233 is adapted to the small piston 242. An expansion cavity 232 is opened on the side wall of the filler tube 23. When the fixed plate 2 moves the pull rod 24 downward, the large piston 241 squeezes the coupling agent to apply it to the inner wall of the cylinder. When the applicator head 22 moves to the bottom of the cylinder, the large piston 241 is slidably positioned inside the expansion cavity 232, and the small piston 242 is slidably connected to the shrinkage cavity 233 to reduce the content of coupling agent. The fixed plate 2 is equipped with a switching assembly including a synchronization arm 322. The two ends of the synchronization arm 322 are rotatably connected to the applicator head 22 and the ultrasonic detection probe 25, respectively, and the synchronization arm 322 is in an inclined state.

[0022] like Figures 1 to 8 As shown in the specific embodiment, four support legs 11 are installed at the bottom of the workbench 1, and pads 111 are rotatably installed at the bottom of the four support legs 11. The pads 111 are in a boss state. A bracket 14 is installed on the workbench 1. The bracket 14 is arched. A controller 12 is also installed on the workbench 1. Reinforcing ribs 141 are installed at the bent positions of the bracket 14. The reinforcing ribs 141 are triangular. The support legs 11 and pads 111 at the bottom of the workbench 1 improve the stability of the equipment placement. The arched bracket 14 and the triangular reinforcing ribs 141 enhance the structural load-bearing strength. Together with the controller 12, centralized control of various components is achieved, improving the overall structural reliability and ease of operation of the equipment.

[0023] like Figures 1 to 8 As shown, a shifting motor 131 is further installed on the workbench 1. The shifting motor 131 is electrically connected to the controller 12, and its output end is connected to the tray 13. The clamping assembly includes three pairs of opposing sliding clamping plates 132. A slider 133 is installed at the bottom of the clamping plate 132. The slider 133 is slidably disposed in a groove 134 opened on the tray 13. A fixing block 136 is installed on the tray 13, and a threaded rod 135 is screwed onto the fixing block 136. The end of the threaded rod 135 is rotatably connected to the side wall of the clamping plate 132. The shifting motor 131 on the workbench 1 drives the tray 13 to rotate. With the clamping structure of the three pairs of clamping plates 132, sliders 133, grooves 134, and threaded rods 135, precise radial positioning of cylinders of different specifications can be achieved. The controller 12 can synchronously control the rotation of the tray 13 to ensure the uniformity of coupling agent application and the comprehensiveness of testing.

[0024] like Figures 1 to 8 As shown, a support plate 137 is further installed on the tray 13 via threads. The support plate 137 supports the bottom of the cylinder and is used to adjust the vertical position of the cylinder so that the end of the cylinder is in close contact with the application head 22. By connecting the support plate 137 to the tray 13 via threads, the vertical height of the cylinder can be flexibly adjusted to ensure precise contact between the end of the cylinder and the application head 22, avoiding waste of coupling agent or insufficient application due to application gaps, and improving the accuracy of the initial position of the coupling agent application.

[0025] Example 2: The difference between the above embodiments and this embodiment is that: Figures 1 to 8As shown, a lifting electric push rod 21 is installed on the bracket 14, and the lifting electric push rod 21 is electrically connected to the controller 12. The output rod of the lifting electric push rod 21 passes through the bracket 14, and an arched frame 211 is installed at the end of the output rod of the lifting electric push rod 211. A fixed plate 2 is installed at the bottom of the arched frame 211, and the outer shell of the packing tube 23 is connected to the bracket 14. The lifting electric push rod 21 and the arched frame 211 on the bracket 14 drive the fixed plate 2 to rise and fall, and with the help of the controller 12, automatic control is achieved, improving the stability and accuracy of the rise and fall of the fixed plate 2. At the same time, the packing tube 23 is fixed to the bracket 14 to ensure the stability of the coupling agent delivery process, further improving the automation level of the equipment.

[0026] like Figures 1 to 8 As shown in the specific embodiment, the coating head 22 has a connecting pipe 221 installed on its outer shell. The connecting pipe 221 is rotatably connected to the synchronous arm 322. A flexible hose 222 is installed at the end of the connecting pipe 221, and the end of the flexible hose 222 is connected to the filler tube 23. The filler tube 23 has a filler port 231 located below the large piston 241, and a cover plate is bolted to the filler port 231. The flexible connection between the coating head 22 and the filler tube 23 is achieved through the connecting pipe 221 and the flexible hose 222, which is suitable for the lifting and switching movements of the coating head 22. The filler port 231 and the cover plate facilitate the replenishment of coupling agent, improve the convenience of equipment maintenance, and ensure the continuity of coupling agent supply.

[0027] like Figures 1 to 8 As shown, the controller 12 is further electrically connected to the ultrasonic detection probe 25. The ultrasonic detection probe 25 has a synchronizing rod 251 installed on its housing. The synchronizing rod 251 is rotatably connected to the synchronizing arm 322. A sliding plate 252 is installed on the synchronizing rod 251. A through groove 253 is opened at the bottom of the fixing plate 2. The through groove 253 is slidably connected to the sliding plate 252. A sliding rod 254 is installed through the sliding plate 252. Both ends of the sliding rod 254 are connected to the through groove 253. A limit spring 255 is sleeved on the sliding rod 254. One end of the limit spring 255 is engaged with the sliding plate 252, and the other end of the limit spring 255 is engaged with the side wall of the through groove 253. By linking the synchronous rod 251 and synchronous arm 322 of the ultrasonic detection probe 25, and with the cooperation of the slide plate 252, through groove 253, slide bar 254 and other structures, the ultrasonic detection probe 25 can be ensured to fit tightly with the inner wall of the cylinder, thereby improving the stability and accuracy of the detection signal. Furthermore, the controller 12 enables the electrical control coordination of the detection probe, thereby improving the level of automation.

[0028] Example 3: The difference between the above embodiments and this embodiment is that: Figures 1 to 8As shown, a drive motor 31 is mounted on the fixed plate 2. A synchronous shaft 311 is mounted on the output rod of the drive motor 31. The end of the synchronous shaft 311 passes through the fixed plate 2, and a cam 3 is mounted on the end of the synchronous shaft 311. A push rod 32 is mounted on the side wall of the connecting tube 221, and a ball bearing 321 is mounted on the end of the push rod 32. The side wall of the ball bearing 321 is slidably connected to the side wall of the cam 3. Through the drive motor 31, synchronous shaft 311, and cam 3 on the fixed plate 2, in conjunction with the push rod 32 and ball bearing 321 of the connecting tube 221, the automatic retraction drive of the applicator head 22 is realized. The ball bearing 321 reduces sliding friction, improves drive stability and component lifespan, and ensures the precise and efficient switching action between the applicator head 22 and the ultrasonic detection probe 25.

[0029] like Figures 1 to 8 As shown, in a specific embodiment, a sealing plug 33 is slidably disposed inside the connecting tube 221. When the applicator head 22 approaches the side of the fixing plate 2, the sealing plug 33 seals the end of the hose 222. An insert rod 331 is installed on the sealing plug 33, and the insert rod 331 is movably inserted into the connecting tube 221. A fixing seat 332 is installed at the end of the insert rod 331, and the end of the fixing seat 332 is installed on the fixing plate 2. Through the sealing plug 33 in the connecting tube 221, the insert rod 331, and the fixing seat 332 on the fixing plate 2, the end of the hose 222 can be automatically sealed after the applicator head 222 retracts, avoiding continuous outflow of coupling agent that would cause waste and pollution, and improving the environmental friendliness and economy of the equipment.

[0030] This invention also discloses an ultrasonic non-destructive testing method for internal defects in a nitrogen spring cylinder, the steps of which are as follows: Step 1: Place the cylinder to be tested on the tray 13, rotate the threaded rod 135 of the fixing block 136, push the clamping plate 132 along the slide groove 134 to clamp the cylinder to achieve radial positioning, rotate the bearing plate 137 to adjust the height of the cylinder so that its end fits the applicator head 22. Step 2: The controller 12 commands the lifting electric push rod 21 to move, which drives the arch frame 211, the fixing plate 2 and the applicator head 22 to extend into the cylinder. The fixing plate 2 moves down and drives the pull rod 24 to slide. The large piston 241 squeezes the coupling agent through the hose 222 to the applicator head 22. At the same time, the shifting motor 131 is controlled to drive the cylinder to rotate, so that the coupling agent is evenly covered in the circumference. When the applicator head 22 reaches the bottom of the cylinder, the small piston 242 cooperates with the shrinking cavity 233 to reduce the amount of coupling agent squeezed out and prevent accumulation. Step 3: The controller 12 controls the drive motor 31 to run, and pushes the push rod 32 through the synchronous shaft 311 and cam 3, which drives the application head 22 to retract. Through the synchronous arm 322, the ultrasonic detection probe 25 is made to fit against the inner wall of the cylinder, and at the same time the sealing plug 33 seals the end of the hose 222. Step 4: The controller 12 adjusts the lifting electric push rod 21 to drive the ultrasonic detection probe 25 to scan up and down, and the synchronous shifting motor 131 drives the cylinder to rotate, so as to achieve full-range detection without blind spots. Step 5: After the test is completed, the controller 12 controls the reset of each component, and after adding coupling agent, the overall equipment is reset and ready for the next test.

[0031] The implementation principle of the ultrasonic non-destructive testing system for internal defects of nitrogen spring cylinders according to the present invention is as follows: Before testing, the nitrogen spring cylinder to be tested is placed on the tray 13. The cylinder is stably positioned by the clamping assembly. In specific operation, the threaded rod 135 of the fixing block 136 on the tray 13 is rotated to push the clamping plate 132 to slide towards each other along the slide groove 134 on the tray 13. The three pairs of clamping plates 132 are used to clamp the cylinder from the periphery to ensure accurate radial positioning of the cylinder. Then, according to the actual height of the cylinder, the vertical position is adjusted by rotating the bearing plate 137 threaded on the tray 13 to make the end of the cylinder fit precisely with the application head 22, preparing for subsequent application of coupling agent and testing. At this time, the controller 12 is in standby mode and the initial position of each component is reset.

[0032] After the test is started, the controller 12 issues a command to control the lifting electric push rod 21 on the bracket 14 to move, causing the arched frame 211 and the fixed plate 2 connected at the bottom to move vertically downward, thereby causing the applicator head 22 on the fixed plate 2 to extend into the inner wall of the cylinder. During this process, since the bottom of the pull rod 24 is installed on the fixed plate 2, the downward movement of the fixed plate 2 will simultaneously drive the pull rod 24 to slide along the inside of the filler tube 23. The large piston 241 on the pull rod 24 will then squeeze the coupling agent in the filler tube 23 downward. The coupling agent is delivered to the applicator head 22 through the hose 222 and is evenly applied to the inner wall of the cylinder. At the same time, the controller 12 controls the operation of the shifting motor 131, which drives the tray 13 and the clamped and fixed cylinder to rotate slowly, so that the coupling agent can be evenly covered along the circumference of the inner wall of the cylinder. As the fixed plate 2 continues to move downwards until the applicator head 22 reaches the bottom of the cylinder, the large piston 241 on the pull rod 24 slides into the expansion cavity 232 on the side wall of the filler tube 23. At this time, the small piston 242 and the contraction cavity 233 on the filler tube 23 form a sliding fit. Since the cross-section of the contraction cavity 233 is smaller than that of the expansion cavity 232, and the small piston 242 is adapted to the contraction cavity 233, the amount of coupling agent extruded is significantly reduced. This design can effectively avoid the problem of excessive local accumulation caused by the natural sliding of coupling agent at the bottom of the cylinder, ensure that the coupling agent content at the bottom of the cylinder is adapted to other areas, and ensure the accuracy of subsequent ultrasonic testing.

[0033] After the coupling agent is applied, the switching component starts to switch the working state of the applicator head 22 and the ultrasonic detection probe 25. The controller 12 controls the drive motor 31 on the fixed plate 2 to operate. The output rod of the drive motor 31 drives the synchronous shaft 311 and the cam 3 at the end to rotate. The side wall of the cam 3 slides into contact with the ball bearing 321 at the end of the push rod 32, pushing the push rod 32 to retract the connecting tube 221 and the applicator head 22 towards the side closer to the fixed plate 2. At the same time, since the two ends of the synchronous arm 322 are rotatably connected to the applicator head 22 and the ultrasonic detection probe 25 respectively, and the synchronous arm 322 is initially in an inclined state, the retraction action of the applicator head 22, through the linkage of the synchronous arm 322, drives the ultrasonic detection probe 25 to move synchronously towards the inner wall of the cylinder. When the applicator head 22 is fully retracted to a position that does not affect the detection, the ultrasonic detection probe 25 is in close contact with the inner wall of the cylinder. During this process, the sealing plug 33 inside the connecting tube 221 moves synchronously with the retraction of the applicator head 22, and finally forms a seal on the end of the hose 222, preventing the coupling agent in the filler tube 23 from continuously flowing out and causing waste and pollution.

[0034] During the ultrasonic testing phase, the controller 12 precisely controls the lifting electric push rod 21 to slowly move the fixed plate 2 upward, allowing the ultrasonic testing probe 25 to scan smoothly along the vertical direction of the cylinder inner wall. Simultaneously, the shifting motor 131 continuously drives the tray 13 and the cylinder to rotate at a uniform speed. Together, they achieve a comprehensive, blind-spot-free scanning test of the cylinder inner wall across its entire circumference and length. Specifically, the controller 12 outputs an excitation electrical signal to the ultrasonic testing probe 25. The piezoelectric crystal inside the ultrasonic testing probe 25 converts the electrical signal into high-frequency mechanical vibration (i.e., ultrasonic waves), which is then vertically emitted to the cylinder inner wall. Since the coupling agent is uniformly filled between the probe and the cylinder wall, the air gap effectively eliminates the obstruction to ultrasonic wave propagation, allowing the ultrasonic waves to efficiently penetrate the cylinder wall. When ultrasonic waves encounter defects (such as cracks, pores, inclusions, etc.) while propagating inside the cylinder, the difference in acoustic impedance between the defect and the cylinder substrate will cause some ultrasonic waves to be reflected, refracted, or scattered. The reflected ultrasonic waves are received by the ultrasonic detection probe 25 and converted back into electrical signals. After the defect signal is processed by the signal processing module (including amplification, filtering, detection, etc.) inside the controller 12, it is converted into a recognizable digital signal or analog signal curve.

[0035] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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. An ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder, comprising a worktable (1), characterized in that: A tray (13) is rotatably mounted on the workbench (1), and a clamping assembly is provided on the tray (13), which is used to clamp the cylinder body; A fixed plate (2) is vertically slidably mounted on the workbench (1). Two pairs of applicator heads (22) and ultrasonic testing probes (25) are staggered on the fixed plate (2). A filler tube (23) is also mounted on the workbench (1). The filler tube (23) is filled with coupling agent. A pull rod (24) is slidably mounted inside the filler tube (23). The bottom of the pull rod (24) is mounted on the fixed plate (2). A large piston (241) and a small piston (242) are vertically mounted on the pull rod (24). The filler tube ( 23) A shrinking cavity (233) is provided on the upper part, the shrinking cavity (233) is adapted to the small piston (242), and an expansion cavity (232) is provided on the side wall of the packing tube (23). When the fixed plate (2) drives the pull rod (24) to move down, the large piston (241) squeezes the coupling agent to be applied to the inner wall of the cylinder. When the application head (22) moves to the bottom of the cylinder, the large piston (241) is slidably placed inside the expansion cavity (232), and the small piston (242) is slidably connected to the shrinking cavity (233) to reduce the content of coupling agent. The fixed plate (2) is equipped with a switching component including a synchronization arm (322). The two ends of the synchronization arm (322) are rotatably connected to the applicator (22) and the ultrasonic detection probe (25) respectively, and the synchronization arm (322) is in an inclined state.

2. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 1, characterized in that, The workbench (1) is equipped with four support legs (11) at the bottom. The four support legs (11) are rotatably mounted with pads (111) at the bottom. The pads (111) are in a boss state. The workbench (1) is equipped with a bracket (14) which is arched. The workbench (1) is also equipped with a controller (12). The bracket (14) is equipped with a reinforcing rib (141) at the bend position. The reinforcing rib (141) is triangular.

3. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 2, characterized in that, A shift motor (131) is installed on the workbench (1). The shift motor (131) is electrically connected to the controller (12). The output end of the shift motor (131) is connected to the tray (13). The clamping assembly includes three pairs of opposing sliding clamps (132). A slider (133) is installed at the bottom of the clamp (132). The slider (133) is slidably disposed in a groove (134) opened on the tray (13). A fixing block (136) is installed on the tray (13). A threaded rod (135) is screwed onto the fixing block (136), and the end of the threaded rod (135) is rotatably connected to the side wall of the clamp (132).

4. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 1, characterized in that, A support plate (137) is screwed onto the tray (13). The support plate (137) is supported at the bottom of the cylinder and is used to adjust the vertical position of the cylinder so that the end of the cylinder is in contact with the applicator (22).

5. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 2, characterized in that, The bracket (14) is equipped with a lifting electric push rod (21), and the lifting electric push rod (21) is electrically connected to the controller (12). The output rod of the lifting electric push rod (21) passes through the bracket (14), and an arched frame (211) is installed at the end of the output rod of the lifting electric push rod (21). A fixing plate (2) is installed at the bottom of the arched frame (211), and the outer shell of the filler tube (23) is connected to the bracket (14).

6. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 1, characterized in that, The coating head (22) is equipped with a connecting pipe (221) on its outer shell. The connecting pipe (221) is rotatably connected to the synchronous arm (322). A flexible hose (222) is installed at the end of the connecting pipe (221). The end of the flexible hose (222) is connected to the filler tube (23). A filler port (231) is opened on the filler tube (23). The filler port (231) is located below the large piston (241), and a cover plate is installed on the filler port (231) by bolts.

7. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 2, characterized in that, The controller (12) is electrically connected to the ultrasonic detection probe (25). The ultrasonic detection probe (25) has a synchronizing rod (251) installed on its outer shell. The synchronizing rod (251) is rotatably connected to the synchronizing arm (322). A sliding plate (252) is installed on the synchronizing rod (251). A through groove (253) is opened at the bottom of the fixing plate (2). The through groove (253) is slidably connected to the sliding plate (252). A sliding rod (254) is installed through the sliding plate (252). Both ends of the sliding rod (254) are connected to the through groove (253). A limiting spring (255) is sleeved on the sliding rod (254). One end of the limiting spring (255) is engaged on the sliding plate (252), and the other end of the limiting spring (255) is engaged on the side wall of the through groove (253).

8. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 6, characterized in that, A drive motor (31) is installed on the fixed plate (2). A synchronous shaft (311) is installed on the output rod of the drive motor (31). The end of the synchronous shaft (311) passes through the fixed plate (2). A cam (3) is installed at the end of the synchronous shaft (311). A push rod (32) is installed on the side wall of the connecting pipe (221). A ball (321) is installed at the end of the push rod (32). The side wall of the ball (321) is slidably connected to the side wall of the cam (3).

9. The ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder according to claim 6, characterized in that, A sealing plug (33) is slidably disposed inside the connecting tube (221). When the applicator head (22) approaches the side of the fixing plate (2), the sealing plug (33) seals the end of the hose (222). A plug rod (331) is installed on the sealing plug (33). The plug rod (331) is movably inserted into the connecting tube (221). A fixing seat (332) is installed at the end of the plug rod (331). The end of the fixing seat (332) is installed on the fixing plate (2).

10. A method for ultrasonic non-destructive testing of internal defects in a nitrogen spring cylinder, characterized in that, An ultrasonic non-destructive testing system for internal defects of a nitrogen spring cylinder, as described in any one of claims 1 to 9, comprises the following steps: Step 1: Place the cylinder to be tested on the tray (13), rotate the threaded rod (135) of the fixing block (136), push the clamping plate (132) along the slide groove (134) to clamp the cylinder to achieve radial positioning, rotate the bearing plate (137) to adjust the height of the cylinder so that its end fits the applicator head (22). Step 2: The controller (12) commands the lifting electric push rod (21) to move, which drives the arch frame (211), the fixing plate (2) and the applicator head (22) to extend into the cylinder. The fixing plate (2) moves down and drives the pull rod (24) to slide. The large piston (241) squeezes the coupling agent through the hose (222) to the applicator head (22). The shifting motor (131) is controlled to drive the cylinder to rotate, so that the coupling agent is evenly covered in the circumference. When the applicator head (22) reaches the bottom of the cylinder, the small piston (242) cooperates with the shrinking cavity (233) to reduce the amount of coupling agent squeezed out and prevent accumulation. Step 3: The controller (12) controls the drive motor (31) to run, and pushes the push rod (32) through the synchronous shaft (311) and cam (3), which drives the coating head (22) to retract. Through the synchronous arm (322), the ultrasonic detection probe (25) is made to fit against the inner wall of the cylinder, and at the same time the sealing plug (33) seals the end of the hose (222). Step 4: The controller (12) adjusts the lifting electric push rod (21) to drive the ultrasonic detection probe (25) to scan up and down, and the synchronous shifting motor (131) drives the cylinder to rotate, so as to achieve full-range detection without dead angles; Step 5: After the test is completed, the controller (12) controls each component to reset, and after adding coupling agent, the equipment is reset as a whole, waiting for the next test.

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