A kind of cavitation jet polishing device and method for blind hole inner surface step effect

Abstract

This invention discloses a cavitation jet polishing device and method for addressing the stepped effect on the inner surface of blind holes. The device includes a polishing chamber, a spiral polishing mechanism, a power chamber, a bidirectional impeller, and a hollow shaft. One end of the hollow shaft extends into the polishing chamber, and the other end passes through the power chamber and extends into the abrasive liquid tank. A flow channel is provided inside the hollow shaft. The polishing chamber has an inlet hole and an outlet hole at its top and bottom, respectively. The polishing chamber has a fixing fixture for holding the blind hole workpiece. The spiral polishing mechanism includes a main shaft and a spiral flow channel, and several cavitation nozzles are provided on the spiral flow channel. The center of the bidirectional impeller is fixedly connected to the hollow shaft. Several first high-pressure nozzles are provided above the power chamber, and second high-pressure nozzles are provided on both sides of the power chamber. This invention polishes the inner surface of blind holes using a cavitation rotating jet generated by the cavitation nozzles. A miniature ultrasonic sensor detects the quality of the inner surface. When a stepped effect is detected on the inner surface of the blind hole, multiple polishing operations are performed to improve the polishing quality.

Description

Technical Field

[0001] This invention relates to the field of fluid polishing technology in surface treatment, specifically a cavitation jet polishing device and method for the step effect on the inner surface of blind holes. Background Technology

[0002] With the continuous development of science and technology and manufacturing, the functional requirements for complex hole-shaped parts widely used in aerospace, biomedicine, and automotive industries are becoming increasingly stringent. However, traditional processing methods are insufficient for manufacturing these structurally complex parts. Additive manufacturing technology, also known as 3D printing, provides a novel solution for producing complex-shaped hole-shaped functional parts by printing metal powder layer by layer, thanks to its speed, flexibility, and high customizability, thus attracting widespread attention and application. However, with the widespread application of additive manufacturing technology, some of its shortcomings have gradually become apparent. One of the most prominent issues is the step effect that increases surface roughness caused by additive manufacturing.

[0003] The step effect refers to the phenomenon in additive manufacturing, particularly when forming curved or inclined surfaces. Due to the layered nature of the processing technology, the finished part cannot achieve a smooth surface, resulting in a stepped appearance at the edges of adjacent layers. This directly leads to a high surface roughness, severely impacting the part's functionality and reliability, and has thus become a critical problem that urgently needs to be solved in the field of additive manufacturing.

[0004] Against this backdrop, post-processing of the inner surface of blind holes is a significant technical challenge, not only due to the step effect in additive manufacturing, but also because addressing the quality of the bottom surface is a difficult problem. To improve the high roughness of the inner surface of additively manufactured blind hole components caused by the step effect, which severely impacts their functionality, many scholars have proposed pre-processing methods such as optimizing design models, changing the forming direction, and reducing the step size of each layer during forming. However, their effectiveness, efficiency, and cost are unsatisfactory. Therefore, post-processing the inner surface of complex functional blind hole cavities prepared by additive manufacturing, and seeking methods to solve the step effect and improve their inner surface quality, is an effective way to enhance their service performance and is currently a research hotspot and a technical bottleneck that urgently needs to be addressed. Summary of the Invention

[0005] To address the defect of a stepped effect on the inner surface of blind holes in existing additively manufactured parts, this invention provides a cavitation jet polishing device and method to address this stepped effect. This invention polishes the inner surface of the blind hole using a cavitation rotating jet generated by a cavitation nozzle. A miniature ultrasonic sensor detects the surface quality; if a stepped effect is still detected, multiple polishing cycles are performed to improve the polishing quality.

[0006] The technical solution adopted in this invention is:

[0007] A cavitation jet polishing device for the stepped effect on the inner surface of blind holes includes a polishing chamber, a spiral polishing mechanism located in the polishing chamber, a power chamber, a bidirectional impeller, and a hollow shaft. One end of the hollow shaft extends into the polishing chamber, and the other end passes through the power chamber and extends outward into the abrasive liquid tank. A third unidirectional hydraulic pump connected to the control center is provided between the hollow shaft and the abrasive liquid tank. A flow channel for the flow of abrasive liquid is provided inside the hollow shaft.

[0008] The polishing chamber is provided with an inlet hole and an outlet hole that are connected to the abrasive liquid tank at the top and bottom, respectively. The pipeline connecting the inlet hole and the abrasive liquid tank is equipped with a first one-way hydraulic pump. The polishing chamber has a fixed fixture for holding blind hole workpieces. The spiral polishing mechanism includes a main shaft located at the center of rotation and a spiral flow channel spirally wound around the outside of the main shaft. The main shaft is threaded on a hollow shaft. The spiral flow channel is provided with an abrasive liquid flow channel that is connected to the flow channel inside the hollow shaft. Several cavitation nozzles are provided on the outer circumference of the spiral flow channel.

[0009] Multiple first high-pressure nozzles are installed above the power chamber, each equipped with an infrared receiving module. Second high-pressure nozzles are installed at both ends of the power chamber. Both the first and second high-pressure nozzles are connected to a water tank via pipelines, and these pipelines are equipped with bidirectional hydraulic pumps that are connected to the control center. First and second signal-triggered water outlets are installed below the power chamber. The bidirectional impeller is located inside the power chamber and fixed on a hollow shaft. A first infrared emitter is installed on the side of the bidirectional impeller closer to the polishing chamber, and a second infrared emitter is installed on the side of the bidirectional impeller farther from the polishing chamber.

[0010] The system includes a first high-pressure nozzle, a second high-pressure nozzle, a first infrared emitter, a second infrared emitter, a first signal-triggered water outlet, a second signal-triggered water outlet, and a first unidirectional hydraulic pump connected to the control center via signal connection.

[0011] Furthermore, the polishing chamber also includes a cavitation polishing disc mounted at the end of a hollow shaft. The cavitation polishing disc comprises a base disc and a rotating disc rotatably connected to the base disc. A baffle and an electromagnetic baffle are mounted on the base disc. A rotating plate is fixedly connected to the circumference of the rotating disc, positioned between the baffle and the electromagnetic baffle. A spring is positioned between the rotating plate and the baffle, with both sides of the spring fixed to the rotating plate and the baffle respectively. The electromagnetic baffle is connected to the control center signal. The rotating plate is made of ferromagnetic material; when energized, the electromagnetic baffle can attract the rotating plate, which in turn drives the rotating disc. The base disk has a hollow externally threaded tube extending outward from the center of the side away from the rotating disk. The hollow shaft has an internal thread at one end that extends into the polishing chamber. The cavitation polishing disc is threaded onto one end of the hollow shaft. The base disk has a spray hole that communicates with the cavity inside the hollow externally threaded tube. The rotating disk has a tapered hole. When the electromagnetic baffle and the rotating plate are in contact, the spray hole and the tapered hole communicate with each other. Several time-delay pressure sensors are evenly arranged on the edge of the end face of the base disk near the rotating disk to detect whether they are in contact with the bottom surface of the blind hole workpiece.

[0012] Furthermore, a three-position four-way solenoid valve connected to the control center is installed on the pipeline between the liquid outlet below the polishing chamber and the abrasive liquid tank. The liquid outlet is connected to the inlet of the three-position four-way solenoid valve through the pipeline. A filter is installed on the pipeline between the liquid outlet and the inlet of the three-position four-way solenoid valve. The first and second outlets of the three-position four-way solenoid valve are both connected to the abrasive liquid tank through pipelines. A second one-way hydraulic pump is installed on the pipeline between the second outlet of the three-position four-way solenoid valve and the abrasive liquid tank.

[0013] A two-position four-way solenoid directional valve connected to the control center is installed between the power chamber and the water tank. The first high-pressure nozzle and the second high-pressure nozzle on the power chamber are both connected to the first medium outlet of the two-position four-way solenoid directional valve. The medium inlet of the two-position four-way solenoid directional valve is connected to the water tank through a pipeline. A bidirectional hydraulic pump is located on the pipeline between the medium inlet of the two-position four-way solenoid directional valve and the water tank. The first signal trigger water outlet and the second signal trigger water outlet below the power chamber are both connected to the second medium outlet of the two-position four-way solenoid directional valve. The discharge port of the two-position four-way solenoid directional valve is connected to the water tank through a pipeline.

[0014] Furthermore, one end of the spiral flow channel is fixed to the main shaft at the fixed connection, and the inner flow channel of the spiral flow channel is connected to the inner flow channel of the hollow shaft at the fixed connection; an adjustment hook is fixedly provided at the other end of the spiral flow channel, and several adjustment protrusions with different distances from the fixed connection and in cooperation with the adjustment hook are provided on the main shaft at positions corresponding to the adjustment hook; the spiral flow channel is made of spring steel; the adjustment protrusions and the adjustment hook adopt an interference fit; a miniature ultrasonic sensor for detecting the surface quality of blind holes is provided on the spiral polishing mechanism.

[0015] Furthermore, the conical hole is frustum-shaped, with the small end of the conical hole located close to the base disk and the diameter of the small end of the conical hole being equal to the diameter of the spray hole; the outer surface material of the delayed pressure sensor is polytetrafluoroethylene.

[0016] Furthermore, the polishing chamber includes a left polishing chamber and a right polishing chamber located on the left and right sides, and the left and right polishing chambers are detachably connected by a sealing groove; the spindle is installed on the hollow shaft by a threaded connection; the hollow shaft and the central axis of the spindle are collinear;

[0017] The power chamber includes a central main cavity, an upper cavity located above and outside the main cavity, side cavities located on the left and right sides of the main cavity and connected to the upper cavity, and a lower cavity located below and outside the main cavity. The upper cavity and side cavities are not directly connected to the lower cavity. A first high-pressure nozzle is located between the main cavity and the upper cavity, and a second high-pressure nozzle is located between the main cavity and the side cavities. A water inlet is provided on the upper cavity to receive water flow from the water tank pump. A first signal-triggered water outlet and a second signal-triggered water outlet are both located between the main cavity and the lower cavity. A water outlet is provided on the lower cavity to discharge water into the water tank.

[0018] Furthermore, a first sealed bearing is provided between the hollow shaft and the right cavity of the polishing chamber, and a first sealing ring is provided between the first sealed bearing and the right cavity of the polishing chamber; a second sealed bearing is provided between the hollow shaft and the power chamber; and a second sealing ring is provided between the second sealed bearing and the power chamber; the power chamber is fixedly mounted on the bracket.

[0019] Furthermore, a rolling bearing is installed at the center of the rotating disk, and a bolt passes through the inner ring of the rolling bearing and is threadedly connected to the base disk. The bolt head size is larger than the inner ring size of the rolling bearing, thereby realizing the rotational connection between the rotating disk and the base disk; the cavitation polishing disk is collinear with the central axis of the hollow shaft.

[0020] A cavitation jet polishing method for addressing the step effect on the inner surface of blind holes using the aforementioned cavitation jet polishing apparatus includes the following steps:

[0021] After the blind hole workpiece is clamped in the polishing chamber and the polishing chamber is assembled, the control center controls the first one-way hydraulic pump to start and controls the three-position four-way solenoid valve to be closed. The abrasive liquid in the abrasive liquid tank is pumped into the polishing chamber by the first one-way hydraulic pump. After the polishing chamber is full of abrasive liquid, the control center controls the third one-way hydraulic pump to start. The abrasive liquid in the abrasive liquid tank is pumped into the hollow shaft by the third one-way hydraulic pump and delivered to the spiral polishing mechanism. At the same time, the control center controls the inlet and the first outlet of the three-position four-way solenoid valve to connect, forming a closed loop of abrasive liquid tank-first one-way hydraulic pump-polishing chamber-filter-three-position four-way solenoid valve-abrasive liquid tank.

[0022] The control center controls the two-position four-way solenoid directional valve to the left position, so that the first medium outlet of the two-position four-way solenoid directional valve is connected to the medium inlet, and the second medium outlet of the two-position four-way solenoid directional valve is connected to the discharge port; the control center controls the bidirectional hydraulic pump to open, and at the same time opens the second high-pressure nozzle at the end away from the polishing chamber, so that the water in the water tank flows into the main cavity of the power chamber from the end away from the polishing chamber. The water flow impacts and pushes the bidirectional impeller to move towards the side closer to the polishing chamber, thereby driving the spiral polishing mechanism and the cavitation polishing disc to move towards the bottom of the blind hole workpiece;

[0023] During the movement of the spiral polishing mechanism, the miniature ultrasonic sensor on the spiral polishing mechanism continuously emits sound waves to detect whether there is a step effect on the inner surface of the blind hole. When the control center receives the signal that the miniature ultrasonic sensor first detects the step effect, the control center controls the second signal trigger water outlet located on the side closer to the polishing chamber to open. The control center controls the second infrared transmitter located on the side farther from the polishing chamber to open. The second infrared transmitter emits infrared signals in real time. The control center controls the first high-pressure nozzle corresponding to the infrared receiving module that receives the infrared signal to open, that is, the first high-pressure nozzle facing the bidirectional impeller to open. As the bidirectional impeller moves towards the side closer to the polishing chamber, the first high-pressure nozzle opens in sequence towards the side closer to the polishing chamber. The rotation of the bidirectional impeller drives the spiral polishing mechanism and the cavitation polishing disc to rotate. The cavitation rotating jet generated by the abrasive liquid at the cavitation nozzle polishes the inner surface of the blind hole.

[0024] When the delayed pressure sensor detects contact with the bottom surface of the blind hole, the control center controls the electromagnetic baffle to be energized, the rotating plate is attached to the electromagnetic baffle, the spray hole and the conical hole are connected, and the abrasive liquid generates a cavitation rotating jet at the conical hole to polish the bottom surface of the blind hole.

[0025] After the set time is reached, the control center controls the closing of the second high-pressure nozzle that is farthest from the polishing chamber, the opening of the second high-pressure nozzle that is closest to the polishing chamber, the closing of the second infrared emitter and the second signal trigger water outlet, and the opening of the first infrared emitter and the first signal trigger water outlet located on the side away from the polishing chamber, so that the bidirectional impeller moves and rotates to the side away from the polishing chamber, and performs secondary repolishing on the inner surface of the blind hole.

[0026] The miniature ultrasonic sensor continuously monitors the quality of the inner surface of the blind hole. If the inner surface quality is still defective, the bidirectional impeller movement direction is changed to repeat the above polishing steps to polish the inner surface of the blind hole. If the inner surface of the blind hole is detected to be smooth and fine, after the spiral polishing mechanism moves to the outside of the blind hole workpiece, the abrasive liquid in the polishing chamber and the water in the power chamber are discharged and recycled, and then all devices are turned off.

[0027] Furthermore, the blind hole workpiece is clamped and positioned inside the left cavity of the polishing chamber using a fixing fixture. The hollow shaft is inserted into the polishing chamber near the blind hole workpiece. The spiral polishing mechanism and the cavitation polishing disc are then installed onto the hollow shaft via threaded connection. Finally, the left cavity and the right cavity of the polishing chamber are connected through a sealing groove, thus assembling the polishing chamber.

[0028] The control center shuts down the first and third unidirectional hydraulic pumps, connects the inlet and second outlet of the three-position four-way solenoid valve, and opens the second unidirectional hydraulic pump. Residual abrasive fluid in the polishing chamber is sequentially cleaned and recycled via the polishing chamber, filter, three-position four-way solenoid valve, second unidirectional hydraulic pump, and abrasive fluid tank. The control center also opens the first and second signal-triggered water outlets, places the two-position four-way solenoid valve in the right position, connects the second medium outlet and medium inlet of the two-position four-way solenoid valve, and changes the delivery direction of the bidirectional hydraulic pump, allowing water from the outlet below the power chamber to be delivered to the water tank. This allows water in the power chamber to flow back into the water tank, thus discharging and recycling the abrasive fluid from the polishing chamber and the water from the power chamber.

[0029] The beneficial effects of this invention are:

[0030] This invention polishes the inner surface of blind holes by using a cavitation rotating jet generated by a cavitation nozzle, and sets a miniature ultrasonic sensor at one end of the spiral polishing mechanism to detect the quality of the inner surface of the blind holes. It can detect whether the inner surface of the blind holes has a step effect. When the step effect is detected, multiple polishing is performed to improve the polishing quality and avoid over-polishing or under-polishing. This can improve the material removal rate of the step effect on the inner surface of blind holes.

[0031] This invention enables the reciprocating and rotating motion of the spiral polishing mechanism and the cavitation polishing disc by using a bidirectional impeller driven by water flow, making the motion more uniform and stable, thereby ensuring the uniformity of polishing; and in conjunction with the first infrared emitter and the second infrared emitter, it can also locate the position of the bidirectional impeller in real time.

[0032] In this invention, when the delayed pressure sensor contacts the bottom surface of the blind hole, the electromagnetic baffle is energized to attract the rotating plate. The conical hole and the spray hole connect to form a simple cavitation nozzle, creating a cavitation rotating jet to polish the bottom surface of the blind hole. Furthermore, due to the delayed characteristic of the delayed pressure sensor, the cavitation polishing disc can remain stably on the bottom surface of the blind hole, thus avoiding factors that could cause the cavitation polishing disc to tilt. The outer surface material of the delayed pressure sensor is made of polytetrafluoroethylene (PTFE). PTFE has a very low coefficient of friction and high stability, which reduces the impact of the rotating delayed pressure sensor on the surface of the blind hole when it contacts the bottom surface.

[0033] In this invention, the pitch can be changed by adjusting the installation position of the pitch adjustment hook to cope with the step effect of different pitch lengths, thus improving the adaptability of the device. The spiral flow channel structure in this invention also helps to effectively discharge polishing waste residue, thereby preventing waste from accumulating and clogging in the holes, and avoiding surface scratches and secondary damage. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the cavitation jet polishing device for the step effect inside blind holes as described in this invention.

[0035] Figure 2 This is a schematic diagram of the spiral polishing mechanism described in this invention.

[0036] Figure 3 This is a front view of the spiral polishing mechanism described in this invention.

[0037] Figure 4 This is an axial view of the spiral polishing mechanism described in this invention.

[0038] Figure 5 This is a three-dimensional schematic diagram of the initial state of the cavitation polishing disk described in this invention.

[0039] Figure 6 For the present invention Figure 5 Top view of the hollow polishing disc.

[0040] Figure 7 This is a cross-sectional view of the cavitation polishing disc of the present invention when the electromagnetic baffle is activated, at which time the spray hole and the conical hole are connected.

[0041] Figure 8 For the present invention Figure 1 Sectional view of AA.

[0042] Figure 9 This is a three-dimensional schematic diagram of the bidirectional impeller described in this invention.

[0043] In the diagram, 1. Left chamber of polishing chamber, 2. Blind hole workpiece, 3. Cavitation polishing disc, 301. Nozzle, 302. Tapered hole, 303. Delayed pressure sensor, 304. Rotating disc, 305. Base disc, 306. Baffle, 307. Spring, 308. Rotating plate, 309. Electromagnetic baffle, 310. Rolling bearing, 311. Bolt, 312. Hollow external threaded pipe, 313. Third sealing ring, 4. Fixing fixture, 5. Miniature ultrasonic sensor, 6. Spiral polishing mechanism, 61. Main shaft, 62. Adjustable distance protrusion, 63. Adjustable distance hook, 64. Spiral flow channel, 65. Cavitation nozzle, 66. Fixed connection, 7. Right chamber of polishing chamber, 8. First sealing ring, 9. First sealing bearing, 10. Power chamber, 101. Main cavity, 102. 103. Upper cavity; 104. Side cavity; 105. Lower cavity; 11. First infrared emitter; 12. Bidirectional impeller; 131. First high-pressure nozzle; 132. Second high-pressure nozzle; 14. Second infrared emitter; 15. Second sealing ring; 16. Second sealed bearing; 17. Hollow shaft; 18. First signal-triggered water outlet; 19. Second signal-triggered water outlet; 20. First unidirectional hydraulic pump; 21. Abrasive fluid tank; 22. Agitator; 23. Second unidirectional hydraulic pump; 24. Three-position four-way solenoid directional valve; 25. Filter; 26. Control center; 27. Water tank; 28. Bidirectional hydraulic pump; 29. ​​Two-position four-way solenoid directional valve; 30. Third unidirectional hydraulic pump; 31. Support. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0045] Figure 1This is a specific embodiment of the cavitation jet polishing device for the stepped effect on the inner surface of blind holes according to the present invention. It includes a polishing module, a power module, and a hollow shaft 17, which is used to link the polishing module and the power module. The main structure of the polishing module is a polishing chamber, which includes a left polishing chamber 1 and a right polishing chamber 7 located on the left and right sides, respectively. The left polishing chamber 1 and the right polishing chamber 7 are detachably connected by sealing grooves. The sealing grooves on both the left and right polishing chambers include protruding and recessed portions, and the protruding portion of one of the left and right polishing chambers 1 and the recessed portion of the other engage to achieve a detachable connection, facilitating the installation and removal of workpieces and polishing tools. A sealing ring is fitted around the outer ring of the groove between the left and right polishing chambers 1 and 7 for secondary sealing to prevent abrasive fluid leakage. The polishing chamber is equipped with a fixing fixture 4, a cavitation polishing disc 3, and a spiral polishing mechanism 6. The fixing fixture 4 is used to clamp and fix the blind hole workpiece 2. The cavitation polishing disc 3 is used to polish the bottom surface of the blind hole of the blind hole workpiece 2. The spiral polishing mechanism 6 is used to polish the side surface of the blind hole of the blind hole workpiece 2. A hollow shaft 17 is provided at the end of the polishing chamber away from the blind hole workpiece 2. The hollow shaft 17 extends through the inner wall of the polishing chamber to the outside. The cavitation polishing disc 3 and the spiral polishing mechanism 6 are both mounted on the hollow shaft 17. The maximum outer diameter of the cavitation polishing disc 3 is smaller than the diameter of the blind hole of the blind hole workpiece 2, that is, there is a gap between the cavitation polishing disc 3 and the inner wall of the blind hole of the blind hole workpiece 2, so that the cavitation polishing disc 3 can be inserted into the blind hole for polishing. The maximum outer dimension of the spiral polishing mechanism 6 in the diameter direction is smaller than the diameter of the blind hole of the blind hole workpiece 2, that is, there is a gap between the spiral polishing mechanism 6 and the inner wall of the blind hole of the blind hole workpiece 2, so that the spiral polishing mechanism 6 can be inserted into the blind hole for polishing. The maximum external dimension of the spiral polishing mechanism 6 in the diameter direction is smaller than the maximum outer diameter of the cavitation polishing disk 3.

[0046] like Figures 2-4As shown, the spiral polishing mechanism 6 includes a main shaft 61 located at the center of rotation and a spiral flow channel 64 spirally arranged around the outside of the main shaft 61. The spiral flow channel 64 has a hollow structure and contains channels for the flow of abrasive fluid. One end of the spiral flow channel 64 is fixed to the main shaft 61. Specifically, the spiral flow channel 64 is fixed to the main shaft 61 at a fixed connection 66. The other end of the spiral flow channel 64 is fixedly provided with an adjusting hook 63. According to the axial length of the spiral flow channel 64, several adjusting protrusions 62 with different distances from the fixed connection 66 are provided on the main shaft 61 at positions corresponding to the adjusting hook 63. The adjusting protrusions 62 and the adjusting hook 63 are configured to cooperate. When the adjusting hook 63 is installed on the adjusting protrusions 62 at different positions, the pitch of the spiral flow channel 64 is also different. Therefore, the pitch can be changed by adjusting the installation position of the adjusting hook 63 to cope with the step effect of different pitch lengths. Specifically, the adjusting protrusion 62 and the adjusting hook 63 are fitted with an interference fit, meaning the diameter of the adjusting protrusion 62 is slightly larger than the inner diameter of the adjusting hook 63. This prevents the adjusting hook 63 from detaching itself after being installed on the adjusting protrusion 62. Especially during the rotation of the spiral polishing mechanism 6, the detachment of the adjusting hook 63 would cause the unfixed end of the spiral flow channel 64 to swing in the direction of centrifugal force, affecting the polishing effect and potentially damaging the inner wall of the blind hole. Before installing the blind hole workpiece 2, the step size of the step effect on the blind hole workpiece 2 can be detected. A fiber optic microscope can be used to detect the step size of the step effect on the inner surface of the blind hole workpiece 2. Based on the detected step size, the installation position of the adjusting hook 63 is adjusted, thereby adjusting the pitch of the spiral flow channel 64. The spiral flow channel 64 is made of spring steel to allow for deformation and good resilience, facilitating pitch adjustment. Furthermore, the adjustable hook 63's open design allows for deformation and good resilience, making it easy to replace the adjustable protrusion 62 at different positions. This avoids the inconvenience of disassembling the adjustable hook 63 when the adjustable protrusion 62 and the adjustable hook 63 are in an interference fit, which could result in insufficient elastic deformation and recovery. Several cavitation nozzles 65, communicating with the internal flow channels of the spiral flow channel 64, are arranged on its outer circumference. Specifically, four cavitation nozzles 65 are evenly distributed per revolution of the spiral flow channel 64. The abrasive fluid inside the spiral flow channel 64 generates cavitation collapse shock waves through the cavitation nozzles 65, synergistically removing surface defects with the abrasive particles. Waste residue from polishing is discharged from the hole as the spiral flow channel 64 rotates.

[0047] The main spindle 61 has a hollow structure and is fixedly mounted on the hollow shaft 17 or detachably mounted on the hollow shaft 17. In this embodiment, the main spindle 61 has an internal thread, and the hollow shaft 17 has an external thread at the mounting position of the main spindle 61. The main spindle 61 is mounted on the hollow shaft 17 by a threaded connection. The hollow shaft 17 passes through the main spindle 61 and the hollow shaft 17 and the main spindle 61 are coaxial, that is, the central axes of the hollow shaft 17 and the main spindle 61 are collinear. This ensures that when the hollow shaft 17 drives the spiral polishing mechanism 6 to rotate, the spiral polishing mechanism 6 will not rotate eccentrically, thus avoiding damage to the inner surface of the blind hole caused by the eccentric rotation of the spiral polishing mechanism 6. The hollow shaft 17 has a channel for conveying abrasive fluid. The spiral flow channel 64 and the main shaft 61 have a connecting port at the fixed connection 66 to connect the internal channel of the hollow shaft 17 and the internal flow channel of the spiral flow channel 64. This allows the abrasive fluid in the hollow shaft 17 to be conveyed through this connecting port to the spiral flow channel 64, and then to the cavitation nozzle 65, where a cavitation jet is formed. A miniature ultrasonic sensor 5 is installed on the spiral polishing mechanism 6 near the cavitation polishing disk 3. The miniature ultrasonic sensor 5 can detect whether there is a step effect in the blind hole of the blind hole workpiece 2. When the sound wave emitted by the miniature ultrasonic sensor 5 on the spiral polishing mechanism 6 first detects the step effect in the blind hole, cavitation jet polishing of the blind hole begins. The miniature ultrasonic sensor evaluates the surface quality of the blind hole by detecting the ultrasonic echo data emitted to the inner surface, thereby detecting whether the inner surface of the blind hole has a step effect. The miniature ultrasonic sensor 5 is connected to the control center via signal. The miniature ultrasonic sensor 5 transmits the stepped effect detected on the inner surface of the blind hole to the control center 26 via signal. The control center 26 issues commands to control the corresponding devices and parts based on the stepped effect on the inner surface of the blind hole.

[0048] like Figures 5-7 As shown, the cavitation polishing disc 3 has an outwardly protruding hollow external threaded tube 312 on the side near the spiral polishing mechanism 6. The end of the hollow shaft 17 extending into the polishing chamber has an internal thread. The cavitation polishing disc 3 is threadedly connected to one end of the hollow shaft 17 through the hollow external threaded tube 312, allowing the cavitation polishing disc 3 to be installed at the end of the hollow shaft 17. Simultaneously, the internal cavity of the hollow external threaded tube 312 communicates with the internal channel of the hollow shaft 17. The cavitation polishing disc 3 and the hollow shaft 17 are coaxially arranged, meaning that the central axes of the cavitation polishing disc 3, the hollow shaft 17, and the main shaft 61 are collinear. This also ensures that the cavitation polishing disc 3 will not rotate eccentrically when the hollow shaft 17 drives it to rotate, preventing damage to the inner surface of the blind hole caused by eccentric rotation. A third sealing ring 313 is provided at the threaded connection between the cavitation polishing disc 3 and the hollow shaft 17 to prevent leakage of abrasive fluid at this connection.

[0049] The cavitation polishing disc 3 includes a rotating disc 304 on the side away from the hollow shaft 17 and a base disc 305 on the side closer to the hollow shaft 17. The rotating disc 304 and the base disc 305 are connected in a rotatable manner. Specifically, a rolling bearing 310 is mounted at the center of the rotating disc 304. A bolt 311 passes through the inner ring of the rolling bearing 310 and is threadedly connected to the base disc 305. The head size of the bolt 311 is larger than the inner ring size of the rolling bearing 310, thus enabling the rotating disc 304 to be rotatably mounted on the base disc 305. In this way, the rotating disc 304 can rotate around its central axis via the rolling bearing 310. The rotating disc 304 is provided with several axially penetrating tapered holes 302. The tapered holes 302 are frustum-shaped, with the larger end of the tapered hole 302 located at the end away from the base disc 305, and the smaller end of the tapered hole 302 located at the end closer to the base disc 305. The base disk 305 has two layers. The side of the base disk 305 near the hollow external threaded tube 312 is a liquid storage chamber that communicates with the internal cavity of the hollow external threaded tube 312. The hollow external threaded tube 312 is fixed on the base disk 305, so that the abrasive fluid in the hollow shaft 17 can be transported to the liquid storage chamber of the base disk 305 through the internal cavity of the hollow external threaded tube 312. The side of the base disk 305 near the rotating disk 304 is provided with a spray hole 301 that communicates with the liquid storage chamber. That is, the abrasive fluid in the hollow shaft 17 can flow through the internal cavity of the hollow external threaded tube 312 and the liquid storage chamber in sequence to the spray hole 301.

[0050] The diameter of the rotating disk 304 is smaller than the diameter of the base disk 305. A baffle 306 and an electromagnetic baffle 309 are disposed on the edge of one end face of the base disk 305 near the rotating disk 304. Gaps are maintained between the baffle 306 and the rotating disk 304, and between the electromagnetic baffle 309 and the rotating disk 304. That is, the baffle 306 and the electromagnetic baffle 309 are located outside the rotating disk 304. Therefore, when the rotating disk 304 rotates, there is no resistance generated between the baffle 306 and the electromagnetic baffle 309 and the rotating disk 304 due to contact; that is, the baffle 306 and the electromagnetic baffle 309 do not interfere with the rotational movement of the rotating disk 304. A certain distance is maintained between the baffle 306 and the electromagnetic baffle 309. The electromagnetic baffle 309 generates magnetism when energized and does not possess magnetism when not energized. A rotating plate 308 is fixedly connected to the circumference of the rotating disk 304, and a gap is left between the rotating plate 308 and the base disk 305 so that no resistance is generated between the rotating plate 308 and the base disk 305 when the rotating disk 304 rotates. The rotating plate 308 is disposed between the baffle 306 and the electromagnetic baffle 309, and the rotating plate 308 and the baffle 306 are connected by a spring 307, that is, the two ends of the spring 307 are fixedly installed on the rotating plate 308 and the baffle 306 respectively. The rotating plate 308 is made of a ferromagnetic material, which can be one of iron, cobalt, or nickel. When the electromagnetic baffle 309 is energized and generates magnetism, it can attract the rotating plate 308, so that the rotating plate 308 drives the rotating disk 304 to rotate as a whole by a certain angle. The number of nozzles 301 and conical holes 302 are equal. In this embodiment, there are eight nozzles 301 and eight conical holes 302. The diameter of the small end of the conical hole 302 is equal to the diameter of the nozzle 301, so that when the rotating plate 308 is attached to the electromagnetic baffle 309, the small end of the conical hole 302 on the rotating disk 304 coincides and connects with the nozzle 301 on the base disk 305. When the electromagnetic baffle 309 is energized, the rotating plate 308 is attracted to the electromagnetic baffle 309, and the rotating disk 304 rotates, which in turn drives the conical hole 302 on it to rotate. When the rotating plate 308 is attached to the electromagnetic baffle 309, the nozzles 301 and conical holes 302 are aligned and connected, forming a simple cavitation nozzle. The abrasive liquid can flow from the nozzle 301 to the conical hole 302, and then a cavitation jet is formed at the point where the conical hole 302 is formed to polish the bottom of the blind hole of the blind hole workpiece 2. When the electromagnetic baffle 309 is not energized, the rotating plate 308 is reset under the action of the spring 307. At this time, the nozzle 301 and the conical hole 302 are misaligned and not connected, and the rotating disk 304 is in a closed state. That is, when the rotating plate 308 is in the initial state, the included angle between the rotating plate 308 and the electromagnetic baffle 309 is the same as the misalignment angle between the nozzle 301 and the conical hole 302.

[0051] Several delayed pressure sensors 303 are evenly arranged on the edge of one end face of the base disk 305 near the rotating disk 304. In this embodiment, four delayed pressure sensors 303 are evenly arranged, and a certain distance is left between the delayed pressure sensors 303 and the circumferential surface of the rotating disk 304 to avoid the delayed pressure sensors 303 affecting the rotation of the rotating disk 304. The delayed pressure sensors 303 are not located between the baffle 306 and the electromagnetic baffle 309, that is, the delayed pressure sensors 303 are located outside the range of motion of the rotating plate 308 and the spring 307 to avoid the delayed pressure sensors 303 affecting the movement of the rotating plate 308 and the operation of the spring 307. The delayed pressure sensors 303 protrude from the rotating disk 304, so that when the cavitation polishing disk 3 moves towards the bottom surface of the blind hole of the blind hole workpiece 2, the delayed pressure sensors 303 contact the bottom surface of the blind hole first. The time-delay pressure sensor 303 and the control center 26 are connected via a signal. When the time-delay pressure sensor 303 contacts the bottom surface of the blind hole, it sends a signal to the control center 26 after a set delay time. The control center 26 then sends a control command to the electromagnetic baffle 309, causing the electromagnetic baffle 309 to be energized and generate magnetism to attract the rotating plate 308, thereby performing cavitation jet polishing on the bottom of the blind hole. Because the time-delay pressure sensor 303 is set with a delay time, if the cavitation polishing disk 3 is tilted to a certain extent, the forward-tilted end will reach the bottom surface of the blind hole before the backward-tilted end. Due to the limitation of the bottom surface of the blind hole, the forward-tilted end will not move after reaching the bottom surface of the blind hole. The time-delay pressure sensor 303 provides a delay effect, allowing the forward-tilted end to wait for the backward-tilted end to reach the bottom surface of the blind hole, thus ensuring that the cavitation polishing disk 3 can remain stably on the bottom surface of the blind hole, thereby avoiding factors that may cause the cavitation polishing disk 3 to tilt. The outer surface material of the time-delay pressure sensor 303 is polytetrafluoroethylene (PTFE). PTFE has a very low coefficient of friction, strong stability, and a long service life. When the time-delay pressure sensor 303 comes into contact with the bottom surface of the blind hole, the cavitation polishing disk 3 will still rotate with the time-delay pressure sensor 303. By using a material with a very low coefficient of friction and strong stability to contact the bottom surface of the blind hole, the impact of the rotating time-delay pressure sensor 303 on the surface of the bottom surface of the blind hole can be reduced. During the polishing process of the cavitation polishing disc 3 on the bottom surface of the blind hole, the single polishing time of the cavitation polishing disc 3 can be set in the control center 26. When this set time is reached, the control center 26 can control the cavitation polishing disc 3 to move away from the bottom of the blind hole. When the delayed pressure sensor 303 does not contact the bottom surface of the blind hole, the delayed pressure sensor 303 stops sending signals to the control center 26. At this time, the control center 26 sends a control command to the electromagnetic baffle 309, so that the electromagnetic baffle 309 is de-energized and no longer generates magnetism. Under the action of the spring 307, the rotating plate 308 is reset, so that the small end of the conical hole 302 on the rotating disc 304 is no longer connected to the spray hole 301 on the base disc 305, that is, the cavitation polishing disc 3 stops polishing the bottom surface of the blind hole.

[0052] The polishing chamber is equipped with an upper inlet and a lower outlet, both communicating with the abrasive slurry tank 21. In this embodiment, both the inlet and outlet are located in the right cavity 7 of the polishing chamber. The inlet is connected to the abrasive slurry tank 21 via a pipeline. A first one-way hydraulic pump 20 is installed between the inlet and the tank 21 to pump the abrasive slurry in the tank 21 to the inlet, and then deliver it into the polishing chamber. The first one-way hydraulic pump 20 is signal-connected to the control center 26, which can send control signals to control the opening and closing of the first one-way hydraulic pump 20. The outlet is connected to the inlet of the three-position four-way solenoid valve 24 via a pipeline. A filter 25 is installed on the pipeline between the outlet and the inlet of the three-position four-way solenoid valve 24. The filter 25 is used to filter the abrasive fluid flowing out of the polishing chamber for easy recycling. The first and second outlets of the three-position four-way solenoid valve 24 are both connected to the abrasive fluid tank via pipelines. A second one-way hydraulic pump 23 is installed on the pipeline between the second outlet of the three-position four-way solenoid valve 24 and the abrasive fluid tank. The second one-way hydraulic pump 23 can provide pump pressure to deliver the abrasive fluid in the polishing chamber to the abrasive fluid tank 21. The three-position four-way solenoid valve 24 and the second one-way hydraulic pump 23 are both signal-connected to the control center 26. The control center 26 can send control signals to control the connection status of the three-position four-way solenoid valve 24 and the opening and closing of the second one-way hydraulic pump 23. When the inlet and first outlet of the three-position four-way solenoid valve 24 are connected and the first one-way hydraulic pump 20 is turned on, a closed-loop flow is formed from the abrasive fluid tank 21 to the first one-way hydraulic pump 20, the polishing chamber, the filter 25, the three-position four-way solenoid valve 24, and the abrasive fluid tank 21. When the inlet and second outlet of the three-position four-way solenoid valve 24 are connected, the first one-way hydraulic pump 20 is turned off, and the second one-way hydraulic pump 23 is turned on, the residual abrasive fluid in the polishing chamber is cleaned and recovered sequentially through the polishing chamber, the filter 25, the three-position four-way solenoid valve 24, the second one-way hydraulic pump 23, and the abrasive fluid tank 21. An agitator 22 is installed inside the abrasive fluid tank 21 to stir the abrasive fluid in the tank 21 evenly. Figure 1 In this embodiment, the inlet of the three-position four-way solenoid valve 24 is port P, the first outlet is port A, and the second outlet is port B.

[0053] The hollow shaft 17 extends out of the polishing chamber at one end away from the cavitation polishing disc 3. In this embodiment, the hollow shaft 17 extends out of the right cavity 7 of the polishing chamber. A first sealing bearing 9 is provided between the hollow shaft 17 and the right cavity 7 of the polishing chamber. Specifically, the right cavity 7 of the polishing chamber has a mounting hole for installing the first sealing bearing 9. The hollow shaft 17 and the inner ring of the first sealing bearing 9 are sealed together and can slide back and forth, thereby enabling the hollow shaft 17 to rotate relative to the polishing chamber. A sealing ring is provided between the hollow shaft 17 and the inner ring of the first sealing bearing 9 to seal the two. A first sealing ring 8 is provided between the first sealing bearing 9 and the right cavity 7 of the polishing chamber for secondary sealing.

[0054] The right side of the polishing module is equipped with a power module, which provides power for the movement and rotation of the cavitation polishing disc 3 and the spiral polishing mechanism 6. The main structure of the power module is a power chamber 10. One end of the hollow shaft 17 extends out of the polishing chamber and axially passes through the power chamber 10. A second sealed bearing 16 is provided between the hollow shaft 17 and the power chamber 10. Specifically, mounting holes for installing the second sealed bearing 16 are provided on both sides of the power chamber 10. The hollow shaft 17 and the inner ring of the second sealed bearing 16 are sealed together and can slide back and forth, thereby enabling the hollow shaft 17 to rotate relative to the power chamber 10. A sealing ring is provided between the hollow shaft 17 and the inner ring of the second sealed bearing 16 to seal the two. A second sealing ring 15 is provided between the second sealed bearing 16 and the power chamber 10 for secondary sealing.

[0055] The hollow shaft 17 passes through the power chamber 10 and connects to the abrasive fluid tank 21. The hollow shaft 17 can extend into the abrasive fluid tank 21 after passing through the power chamber 10, or it can connect to the abrasive fluid tank 21 through a pipe after passing through the power chamber 10. A third one-way hydraulic pump 30 is provided to provide pump pressure on the extension of the hollow shaft 17 outside the power chamber 10 or on the pipe between the hollow shaft 17 and the abrasive fluid tank 21. When the third one-way hydraulic pump 30 is turned on, it can transport the abrasive fluid in the abrasive fluid tank 21 to the hollow shaft 17. The third one-way hydraulic pump 30 is connected to the control center 26 by signal, and the control center 26 can send control signals to control the opening and closing of the third one-way hydraulic pump 30.

[0056] The power compartment 10 is fixedly mounted on the bracket 31, such as Figure 8As shown, the power chamber 10 includes a central main cavity 101, an upper cavity 102 located above and outside the main cavity 101, side cavities 103 located on the left and right sides of the main cavity 101 and connected to the upper cavity 102, and a lower cavity 104 located below and outside the main cavity 101. The upper cavity 102 and the side cavities 103 are not directly connected to the lower cavity 104. The upper cavity 102 is provided with a water inlet for receiving water pumped from the water tank 27. Specifically, the water inlet is connected to the first medium outlet of the two-position four-way solenoid valve 29. The medium inlet of the two-position four-way solenoid valve 29 is connected to the water tank 27 through a pipeline. A bidirectional hydraulic pump 28 is installed on the pipeline between the medium inlet of the two-position four-way solenoid valve 29 and the water tank 27 to provide pumping power when transporting water. A row of first high-pressure nozzles 131 arranged axially is disposed between the main cavity 101 and the upper cavity 102. The first high-pressure nozzles 131 can connect the main cavity 101 and the upper cavity 102, spraying water from the upper cavity 102 into the main cavity 101 in the form of a high-pressure water jet. Second high-pressure nozzles 132 are disposed between the main cavity 101 and the side cavities 103 on both sides. The second high-pressure nozzles 132 can connect the main cavity 101 and the side cavities 103, spraying water from the side cavities 103 into the main cavity 101 in the form of a high-pressure water jet. The upper cavity 102 and the side cavities 103 can then transport water from the water tank 27 to the first high-pressure nozzles 131 and the second high-pressure nozzles 132, thus connecting the first high-pressure nozzles 131 and the second high-pressure nozzles 132 to the water tank 27. Both the first high-pressure nozzle 131 and the second high-pressure nozzle 132 are equipped with miniature solenoid valves that can control their on / off states. These miniature solenoid valves are signal-connected to the control center 26. The control center 26 issues commands to the miniature solenoid valves on the first high-pressure nozzle 131 and / or the second high-pressure nozzle 132 to control their on / off states based on the stepped effect of the inner surface of the blind hole detected by the miniature ultrasonic sensor 5. A first signal-triggered water outlet 18 and a second signal-triggered water outlet 19 are provided between the main cavity 101 and the lower cavity 104. The first signal-triggered water outlet 18 and the second signal-triggered water outlet 19 are located at opposite ends of the power chamber 10 in the axial direction. The first signal-triggered water outlet 18 is located on the side of the power chamber 10 away from the polishing chamber, and the second signal-triggered water outlet 19 is located on the side closer to the polishing chamber. That is, in this embodiment, the first signal-triggered water outlet 18 is located on the right side of the power chamber 10, and the second signal-triggered water outlet 19 is located on the left side of the power chamber 10.Both the first signal-triggered water outlet 18 and the second signal-triggered water outlet 19 can connect to the main cavity 101 and the lower cavity 104, draining water from the main cavity 101 into the lower cavity 104. Each of the first and second signal-triggered water outlets 18 and 19 is equipped with a miniature solenoid valve for controlling their on / off state. These miniature solenoid valves are connected to the control center 26, which can send control signals to open and close the miniature solenoid valves on the first and / or second signal-triggered water outlets 18 and 19, thereby controlling their on / off state. The lower cavity 104 has a water outlet for draining water into the water tank 27. Specifically, this water outlet is connected to the second medium outlet of a two-position four-way solenoid valve 29, and the discharge port of the two-position four-way solenoid valve 29 is connected to the water tank 27 via a pipe. Both the two-position four-way solenoid directional valve 29 and the bidirectional hydraulic pump 28 are signal-connected to the control center 26. The control center 26 can send control signals to control the connection status of the two-position four-way solenoid directional valve 29 and the opening, closing, and conveying direction of the bidirectional hydraulic pump 28. When the two-position four-way solenoid directional valve 29 is in the left position, the first medium outlet of the two-position four-way solenoid directional valve 29 is connected to the medium inlet, and the second medium outlet of the two-position four-way solenoid directional valve 29 is connected to the discharge port. At this time, the water outlet below the power chamber 10 is connected to the water tank 27. The bidirectional hydraulic pump 28 is started and its conveying direction is controlled, so that the bidirectional hydraulic pump 28 conveys water from the water tank 27 to the water inlet above the power chamber 10. When the two-position four-way solenoid directional valve 29 is in the right position, the second medium outlet of the two-position four-way solenoid directional valve 29 is connected to the medium inlet. At this time, the conveying direction of the bidirectional hydraulic pump 28 is changed, so that the water from the water outlet below the power chamber 10 is conveyed to the water tank 27. Figure 1 In this embodiment, the medium inlet of the two-position four-way solenoid valve 29 is port P, the first medium outlet is port A, the second medium outlet is port B, and the discharge port is port O.

[0057] A bidirectional impeller 12 is installed inside the main cavity 101 of the power chamber 10. A gap is left between the bidirectional impeller 12 and the power chamber 10. Specifically, the gap between the bidirectional impeller 12 and the main cavity 101 facilitates the back-and-forth movement and rotation of the bidirectional impeller 12 within the power chamber 10. Simultaneously, the gap between the bidirectional impeller 12 and the main cavity 101 is not too large, reducing the mutual flow of water on both sides of the bidirectional impeller 12 and facilitating the formation of a pressure difference on both sides of the bidirectional impeller 12. When a pressure difference is formed, the bidirectional impeller 12 can move towards the end with lower pressure. The center of the bidirectional impeller 12 is fixedly connected to the hollow shaft 17, thereby realizing the linkage between the bidirectional impeller 12 in the power chamber 10 and the cavitation polishing disc 3 and the spiral polishing mechanism 6 in the polishing chamber. A first infrared emitter 11 is disposed on the side of the bidirectional impeller 12 closest to the polishing chamber, and a second infrared emitter 14 is disposed on the side of the bidirectional impeller 12 furthest from the polishing chamber. In this embodiment, the first infrared emitter 11 and the second infrared emitter 14 are respectively disposed on the left and right sides of the bidirectional impeller 12. Both the first infrared emitter 11 and the second infrared emitter 14 are signal-connected to the control center 26, which can send signals to control the opening and closing of the first infrared emitter 11 and the second infrared emitter 14. When the first infrared emitter 11 or the second infrared emitter 14 is turned on, it emits infrared rays. An infrared receiving module capable of receiving infrared rays is disposed on the first high-pressure nozzle 131, and the infrared receiving module on the first high-pressure nozzle 131 is signal-connected to the control center 26. The control center 26 can determine the position of the bidirectional impeller 12 based on the position of the first high-pressure nozzle 131 corresponding to the infrared receiving module that receives the infrared signal. The control center 26 can also send a control signal to the miniature solenoid valve on the corresponding first high-pressure nozzle 131 to control its on / off state. This ensures that the first high-pressure nozzle 131 facing the bidirectional impeller 12 remains open during its movement. The water sprayed from the first high-pressure nozzle 131 impacts the blades of the bidirectional impeller 12, causing it to rotate. This, in turn, drives the rotation of the cavitation polishing disc 3 and the spiral polishing mechanism 6 within the polishing chamber. The central axes of the bidirectional impeller 12 and the hollow shaft 17 are collinear, meaning they are coaxial. This avoids uneven force on the blades of the bidirectional impeller 12 due to misalignment, thus preventing uneven rotation speed. Coaxiality ensures a more uniform rotation speed for the bidirectional impeller 12, resulting in more uniform polishing of the blind holes. In addition, the water jet pressure from the first high-pressure nozzle 131 and the second high-pressure nozzle 132 can be controlled by controlling the water flow rate, thereby controlling the movement and rotation speed of the bidirectional impeller 12. When the flow rate is kept constant, the bidirectional impeller 12 moves smoothly. Figure 9As shown, the bidirectional impeller 12 has symmetrical blades on both sides, ensuring that the impeller rotates in the same direction when water flows over the blades. A circular connecting plate is located between the blades on both sides of the bidirectional impeller 12 to block the water flow and prevent it from flowing between adjacent blades, thus creating a pressure difference on both sides of the impeller 12. The blades on both sides of the bidirectional impeller 12 and the connecting plate in the middle can be fixedly connected or integrated into one piece.

[0058] The method for polishing the blind hole workpiece 2 using the cavitation jet polishing device for the stepped effect on the inner surface of the blind hole as described in this invention is as follows:

[0059] Before starting work, the blind hole workpiece 2 is first positioned inside the left cavity 1 of the polishing chamber using the fixing fixture 4. The hollow shaft 17 is inserted into the right cavity 7 of the polishing chamber near the blind hole workpiece 2. Specifically, one end of the hollow shaft 17 is installed in the right cavity 7 of the polishing chamber through the first sealing bearing 9, and a first sealing ring 8 is provided between the first sealing bearing 9 and the right cavity 7 of the polishing chamber for secondary sealing. The spiral polishing mechanism 6 and the cavitation polishing disc 3 are then installed onto the hollow shaft 17 by threaded connection. Then, the left cavity 1 and the right cavity 7 of the polishing chamber are connected by a sealing groove, and a sealing ring is provided on the outer ring of the connecting groove for secondary sealing. When connecting the left cavity 1 and the right cavity 7 of the polishing chamber, it is ensured that the cavitation polishing disc 3 is located inside the blind hole of the blind hole workpiece 2. At this time, the spring 307 on the cavitation polishing disc 3 is in its natural state, and the included angle between the rotating plate 308 and the electromagnetic baffle 309 is the same as the misalignment angle between the spray hole 301 and the conical hole 302. The spray hole 301 and the conical hole 302 are not connected. Once preparations are complete, you can begin work.

[0060] When the work begins, the control center 26 sends control signals to the first one-way hydraulic pump 20 and the three-position four-way solenoid valve 24 respectively. The first one-way hydraulic pump 20 is started and the three-position four-way solenoid valve 24 is in the closed state. The first one-way hydraulic pump 20 provides pumping power to pump the abrasive liquid in the abrasive liquid tank 21 into the liquid inlet above the polishing chamber and then into the polishing chamber. After the polishing chamber is filled with abrasive fluid, the control center 26 sends a control signal to the third one-way hydraulic pump 30 to start the third one-way hydraulic pump 30. The third one-way hydraulic pump 30 provides pumping power to pump the abrasive fluid in the abrasive fluid tank 21 into the hollow shaft 17. The abrasive fluid in the hollow shaft 17 is transported to the spiral polishing mechanism 6 through the connecting port on the fixed connection 66. At the same time, the control center 26 sends a control signal to the three-position four-way solenoid valve 24 to connect the inlet and the first outlet of the three-position four-way solenoid valve 24, forming a closed loop flow of abrasive fluid tank 21-first one-way hydraulic pump 20-polishing chamber-filter 25-three-position four-way solenoid valve 24-abrasive fluid tank 21.

[0061] The control center 26 sends a control signal to the two-position four-way solenoid directional valve 29, controlling the two-position four-way solenoid directional valve 29 to be in the left position, the first medium outlet of the two-position four-way solenoid directional valve 29 to be connected to the medium inlet, and the second medium outlet of the two-position four-way solenoid directional valve 29 to be connected to the discharge port. The control center 26 sends a control signal to the bidirectional hydraulic pump 28 to turn it on. The control center 26 also sends a control command to the miniature solenoid valve on the second high-pressure nozzle 132 at the end away from the polishing chamber, that is, to activate the miniature solenoid valve on the rightmost second high-pressure nozzle 132 in this embodiment, so that the second high-pressure nozzle 132 is in the open state. At this time, the bidirectional hydraulic pump 28 pumps the water in the water tank to the upper cavity 102 and the side cavity 103 of the power chamber 10. The water flows from the rightmost second high-pressure nozzle 132 into the right side of the main cavity 101 in the power chamber 10. As the water flow increases, the bidirectional impeller 12 moves to the left under the push of the water flow, thereby driving the spiral polishing mechanism 6 and the cavitation polishing disc 3 to move towards the bottom of the blind hole workpiece 2. During the process of the spiral polishing mechanism 6 and the cavitation polishing disc 3 moving towards the bottom of the blind hole workpiece 2, the second high-pressure nozzle 132 at the end away from the polishing chamber is always in the open state. During the movement of the spiral polishing mechanism 6, the miniature ultrasonic sensor 5 on the spiral polishing mechanism 6 continuously emits sound waves to detect whether there is a step effect on the inner surface of the blind hole. When the control center 26 receives the signal that the miniature ultrasonic sensor 5 has detected the step effect for the first time, the control center 26 sends control signals to the second infrared transmitter 14 on the right side of the bidirectional impeller 12 and the miniature solenoid valve on the second signal-triggered water outlet 19 on the left side, respectively, to control the second infrared transmitter 14 to start and the second signal-triggered water outlet 19 to open; the second infrared transmitter 14 emits infrared signals in real time, and the control center 26 sends control signals to the miniature solenoid valve on the first high-pressure nozzle 131 corresponding to the infrared receiving module that receives the infrared signals. The system controls the first high-pressure nozzle 131 to be in the open state. During the leftward movement of the bidirectional impeller 12, the first high-pressure nozzle 131 facing the bidirectional impeller 12 and the second high-pressure nozzle 132 away from the polishing chamber remain open, allowing the bidirectional impeller 12 to move and rotate simultaneously. The first high-pressure nozzle 131 not facing the bidirectional impeller 12 remains closed, ensuring uniform rotation and movement speed of the bidirectional impeller 12. Specifically, the first high-pressure nozzle 131 opens sequentially to the left, continuously impacting the blades of the bidirectional impeller 12 with water flow, causing the bidirectional impeller 12 to rotate. This, in turn, drives the spiral polishing mechanism 6 and the cavitation polishing disc 3 to rotate. The cavitation rotating jet generated by the cavitation nozzle 65 polishes the inner surface of the blind hole, precisely and efficiently removing surface defects. During the polishing process, waste residue is transported along the rotation direction of the spiral flow channel 64 to the outlet below the polishing chamber. The residue abrasive liquid is filtered by the filter 25 and returned to the abrasive liquid tank 21 for recycling.

[0062] When the cavitation polishing disk 3 moves to the bottom surface of the blind hole, the delayed pressure sensor 303 first contacts the bottom surface of the blind hole. Due to its special delay effect, the entire cavitation polishing disk 3 can be kept stably on the bottom surface of the blind hole, thereby avoiding some factors that may cause the polishing disk to tilt. After a set delay time, the delay pressure sensor 303 sends a signal to the control center 26. The control center 26 sends a control command to the electromagnetic baffle 309, causing the electromagnetic baffle 309 to be energized and generate magnetism to attract the rotating plate 308. When the rotating plate 308 is in contact with the electromagnetic baffle 309, the rotating disk 304 is driven to rotate by the rotating plate 308 to rotate by a certain angle, so that the small end of the conical hole 302 on the rotating disk 304 coincides and connects with the spray hole 301 on the base disk 305, forming a simple cavitation spray hole. The abrasive liquid in the liquid storage chamber on the base disk 305 passes through the simple cavitation nozzle to form a cavitation rotating jet to polish the bottom surface of the blind hole. The generated slag flows out of the polishing chamber from both sides of the polishing disk with the rotation of the spiral flow channel 64.

[0063] Upon reaching the set time, the control center 26 sends control signals to the miniature solenoid valves on the second high-pressure nozzles 132, the miniature solenoid valves on the first signal-triggered water outlet 18 and the second signal-triggered water outlet 19, the first infrared transmitter 11, and the second infrared transmitter 14 on both sides of the power chamber 10. These signals control the second high-pressure nozzles 132, the second signal-triggered water outlet 19, and the second infrared transmitter 14 on the side of the power chamber 10 away from the polishing chamber to close, and control the second high-pressure nozzles 132, the first signal-triggered water outlet 18, and the first infrared transmitter 11 on the side of the power chamber 10 closer to the polishing chamber to open. Water flows from the second high-pressure nozzle 132 near the polishing chamber into the left side of the main cavity 101 in the power chamber 10. As the water flow increases, the bidirectional impeller 12 moves to the right under the push of the water flow. At the same time, the control center 26 always controls the first high-pressure nozzle 131 facing the bidirectional impeller 12 to open, while the first high-pressure nozzle 131 not facing the bidirectional impeller 12 is in the closed state. That is, the first high-pressure nozzle 131 opens to the right in sequence, and the continuous water flow impacts the blades of the bidirectional impeller 12, causing the bidirectional impeller 12 to drive the spiral polishing mechanism 6 and the cavitation polishing disk 3 to move and rotate in the opposite direction, thus performing secondary repolishing.

[0064] The miniature ultrasonic sensor 5 continuously monitors the surface quality of the blind hole. If the surface quality is still defective, the moving direction of the bidirectional impeller 12 is changed to repeat the above polishing steps to polish the inner surface of the blind hole. The inner surface of the blind hole is polished multiple times until it is detected that there is no step effect on the inner surface of the blind hole and the inner surface of the blind hole is smooth and fine. If the inner surface of the blind hole is detected to be smooth and fine, after the spiral polishing mechanism 6 moves outside the blind hole workpiece 2, the control center 26 sends control signals to the first unidirectional hydraulic pump 20 and the third unidirectional hydraulic pump 30 respectively to control the first unidirectional hydraulic pump 20 and the third unidirectional hydraulic pump 30 to shut down. The control center 26 sends control signals to the three-position four-way solenoid valve 24 and the second unidirectional hydraulic pump 23 respectively to control the inlet and the second outlet of the three-position four-way solenoid valve 24 to connect and the second unidirectional hydraulic pump 23 to open. The residual abrasive liquid in the polishing chamber is cleaned and recovered by passing through the polishing chamber-filter 25-three-position four-way solenoid valve 24-second unidirectional hydraulic pump 23-abrasive liquid tank 21 in sequence. Simultaneously, the control center 26 sends control signals to the miniature solenoid valves, two-position four-way solenoid directional valve 29, and bidirectional hydraulic pump 28 on the first signal-triggered water outlet 18 and the second signal-triggered water outlet 19, controlling them to open the first signal-triggered water outlet 18 and the second signal-triggered water outlet 19, controlling the two-position four-way solenoid directional valve 29 to be in the right position, connecting the second medium outlet and the medium inlet of the two-position four-way solenoid directional valve 29, and controlling the change of the delivery direction of the bidirectional hydraulic pump 28, so that the water from the water outlet below the power chamber 10 is delivered to the water tank 27, thereby causing the water in the power chamber 10 to flow back into the water tank 27. After the recovery of residual abrasive liquid in the polishing chamber and the recovery of water in the power chamber 10 are completed, the control center 26 sends control signals to other opened devices to close all devices, thus completing the polishing of the inner surface and bottom surface of the blind hole of the blind hole workpiece.

[0065] The examples described are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the protection scope of the present invention.

Claims

1. A cavitation jet polishing device for the stepped effect on the inner surface of blind holes, characterized in that: It includes a polishing chamber, a spiral polishing mechanism (6) located inside the polishing chamber, a power chamber (10), a bidirectional impeller (12), and a hollow shaft (17). One end of the hollow shaft (17) extends into the polishing chamber, and the other end passes through the power chamber (10) and extends outward into the abrasive liquid tank (21). A third unidirectional hydraulic pump (30) connected to the control center (26) is provided between the hollow shaft (17) and the abrasive liquid tank (21). A flow channel for the abrasive liquid to flow is provided inside the hollow shaft (17). The polishing chamber is provided with an inlet hole and an outlet hole that are connected to the abrasive liquid tank (21) at the top and bottom respectively. The pipeline connected to the abrasive liquid tank (21) by the inlet hole is provided with a first one-way hydraulic pump (20). The polishing chamber has a fixed clamp (4) for holding the blind hole workpiece (2). The spiral polishing mechanism (6) includes a main shaft (61) located at the center of rotation and a spiral flow channel (64) spirally wound around the outside of the main shaft (61). The main shaft (61) is threaded on the hollow shaft (17). The spiral flow channel (64) is provided with an abrasive liquid flow channel that is connected to the flow channel inside the hollow shaft (17). Several cavitation nozzles (65) are provided on the outer circumference of the spiral flow channel (64). Multiple first high-pressure nozzles (131) are installed above the power chamber (10). Each of the multiple first high-pressure nozzles (131) is equipped with an infrared receiving module. Second high-pressure nozzles (132) are installed at both ends of the power chamber (10). The first high-pressure nozzles (131) and the second high-pressure nozzles (132) are connected to the water tank (27) through pipelines, and the pipelines are equipped with bidirectional hydraulic pumps (28) that are connected to the control center (26) via signals. A first signal trigger water outlet (18) and a second signal trigger water outlet (19) are installed below the power chamber (10). The bidirectional impeller (12) is located inside the power chamber (10) and is fixed on the hollow shaft (17). A first infrared emitter (11) is installed on the side of the bidirectional impeller (12) closer to the polishing chamber, and a second infrared emitter (14) is installed on the side of the bidirectional impeller (12) away from the polishing chamber. The first high-pressure nozzle (131), the second high-pressure nozzle (132), the first infrared emitter (11), the second infrared emitter (14), the first signal-triggered water outlet (18), the second signal-triggered water outlet (19), the first one-way hydraulic pump (20) and the control center (26) are connected by signal. One end of the spiral flow channel (64) is fixed to the main shaft (61) at the fixed connection (66), and the inner flow channel of the spiral flow channel (64) is connected to the inner flow channel of the hollow shaft (17) at the fixed connection (66); the other end of the spiral flow channel (64) is fixedly provided with an adjustment hook (63), and several adjustment protrusions (62) are provided on the main shaft (61) at positions corresponding to the adjustment hook (63), which are at different distances from the fixed connection (66) and cooperate with the adjustment hook (63); the spiral flow channel (64) is made of spring steel; the adjustment protrusions (62) and the adjustment hook (63) are interference fit; a miniature ultrasonic sensor (5) for detecting the surface quality of blind holes is provided on the spiral polishing mechanism (6).

2. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 1, characterized in that, The polishing chamber also contains a cavitation polishing disc (3) mounted on the end of a hollow shaft (17). The cavitation polishing disc (3) includes a base disc (305) and a rotating disc (304) rotatably connected to the base disc (305). A baffle (306) and an electromagnetic baffle (309) are provided on the base disc (305). A rotating plate (308) is fixedly connected to the circumference of the rotating disc (304), and the rotating plate (308) is located between the baffle (306) and the electromagnetic baffle (309). A spring (307) is provided between the rotating plate (308) and the baffle (306), and the two sides of the spring (307) are fixed to the rotating plate (308) and the baffle (306) respectively. The electromagnetic baffle (309) is connected to the control center (26) via a signal. The rotating plate (308) is made of ferromagnetic material. When the electromagnetic baffle (309) is energized, it can attract the rotating plate (308). The plate (308) can drive the rotating disk (304) to rotate; a hollow external threaded tube (312) extending outward is provided on the center of the side of the base disk (305) away from the rotating disk (304), and an internal thread is provided on the end of the hollow shaft (17) that extends into the polishing chamber. The cavitation polishing disk (3) is threaded on one end of the hollow shaft (17); a spray hole (301) communicating with the internal cavity of the hollow external threaded tube (312) is provided in the base disk (305), and a conical hole (302) is provided on the rotating disk (304). When the electromagnetic baffle (309) and the rotating plate (308) are in contact, the spray hole (301) and the conical hole (302) are connected; a number of time-delayed pressure sensors (303) for detecting whether they are in contact with the bottom surface of the blind hole workpiece (2) are uniformly provided on the edge of the end face of the base disk (305) near the rotating disk (304).

3. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 2, characterized in that, A three-position four-way solenoid valve (24) connected to the control center (26) is installed on the pipeline between the liquid outlet below the polishing chamber and the abrasive liquid tank (21). The liquid outlet is connected to the inlet of the three-position four-way solenoid valve (24) through the pipeline. A filter (25) is installed on the pipeline between the liquid outlet and the inlet of the three-position four-way solenoid valve (24). The first outlet and the second outlet of the three-position four-way solenoid valve (24) are both connected to the abrasive liquid tank through the pipeline. A second one-way hydraulic pump (23) is installed on the pipeline between the second outlet of the three-position four-way solenoid valve (24) and the abrasive liquid tank. A two-position four-way solenoid directional valve (29) connected to the control center (26) is installed between the power chamber (10) and the water tank (27). The first high-pressure nozzle (131) and the second high-pressure nozzle (132) on the power chamber (10) are connected to the first medium outlet of the two-position four-way solenoid directional valve (29). The medium inlet of the two-position four-way solenoid directional valve (29) is connected to the water tank (27) through a pipeline. The bidirectional hydraulic pump (28) is located on the pipeline between the medium inlet of the two-position four-way solenoid directional valve (29) and the water tank (27). The first signal trigger water outlet (18) and the second signal trigger water outlet (19) below the power chamber (10) are connected to the second medium outlet of the two-position four-way solenoid directional valve (29). The discharge port of the two-position four-way solenoid directional valve (29) is connected to the water tank (27) through a pipeline.

4. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 3, characterized in that, The conical hole (302) is frustum shaped, with the small end of the conical hole (302) located close to the base disk (305) and the diameter of the small end of the conical hole (302) being equal to the diameter of the nozzle (301); the outer surface material of the time-delay pressure sensor (303) is polytetrafluoroethylene.

5. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 4, characterized in that, The polishing chamber includes a left polishing chamber (1) and a right polishing chamber (7) located on the left and right sides. The left polishing chamber (1) and the right polishing chamber (7) are detachably connected by a sealing slot. The spindle (61) is installed on the hollow shaft (17) by a threaded connection. The central axes of the hollow shaft (17) and the spindle (61) are collinear. The power chamber (10) includes a main cavity (101) located at the center, an upper cavity (102) located above and outside the main cavity (101), side cavities (103) located on the left and right sides of the main cavity (101) and connected to the upper cavity (102), and a lower cavity (104) located below and outside the main cavity (101). The upper cavity (102) and the side cavity (103) are not directly connected to the lower cavity (104). The first high-pressure nozzle (131) is located in the main cavity (101). Between the upper cavity (102) and the side cavity (103), the second high-pressure nozzle (132) is located between the main cavity (101) and the side cavity (103). The upper cavity (102) is provided with a water inlet for receiving the water flow pumped in from the water tank (27). The first signal triggered water outlet (18) and the second signal triggered water outlet (19) are both located between the main cavity (101) and the lower cavity (104). The lower cavity (104) is provided with a water outlet for discharging water into the water tank (27).

6. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 1, characterized in that, A first sealed bearing (9) is provided between the hollow shaft (17) and the right cavity (7) of the polishing chamber, and a first sealing ring (8) is provided between the first sealed bearing (9) and the right cavity (7) of the polishing chamber; a second sealed bearing (16) is provided between the hollow shaft (17) and the power chamber (10); and a second sealing ring (15) is provided between the second sealed bearing (16) and the power chamber (10); the power chamber (10) is fixedly installed on the bracket (31).

7. The cavitation jet polishing apparatus for the stepped effect on the inner surface of blind holes according to claim 2, characterized in that, The rotating disk (304) is equipped with a rolling bearing (310) at its center. A bolt (311) passes through the inner ring of the rolling bearing (310) and is threadedly connected to the base disk (305). The head size of the bolt (311) is larger than the inner ring size of the rolling bearing (310), thereby realizing the rotational connection between the rotating disk (304) and the base disk (305). The cavitation polishing disk (3) is collinear with the central axis of the hollow shaft (17).

8. A cavitation jet polishing method for the stepped effect on the inner surface of blind holes, characterized in that, The polishing process, performed using the cavitation jet polishing apparatus described in claim 5, includes the following steps: After the blind hole workpiece (2) is clamped in the polishing chamber and the polishing chamber is assembled, the control center (26) controls the first one-way hydraulic pump (20) to start and controls the three-position four-way solenoid valve (24) to be closed. The abrasive liquid in the abrasive liquid tank (21) is pumped into the polishing chamber by the first one-way hydraulic pump (20). After the abrasive liquid fills the polishing chamber, the control center (26) controls the third one-way hydraulic pump (30) to start. The abrasive liquid in the abrasive liquid tank (21) is pumped into the hollow shaft (17) by the third one-way hydraulic pump (30) and transported to the spiral polishing mechanism (6). At the same time, the control center (26) controls the inlet and the first outlet of the three-position four-way solenoid valve (24) to connect, forming a closed loop of abrasive liquid tank (21) - first one-way hydraulic pump (20) - polishing chamber - filter (25) - three-position four-way solenoid valve (24) - abrasive liquid tank (21). The control center (26) controls the two-position four-way solenoid directional valve (29) to be in the left position, so that the first medium outlet of the two-position four-way solenoid directional valve (29) is connected to the medium inlet, and the second medium outlet of the two-position four-way solenoid directional valve (29) is connected to the discharge port; the control center (26) controls the bidirectional hydraulic pump (28) to open, and at the same time opens the second high-pressure nozzle (132) at the end away from the polishing chamber, so that the water in the water tank (27) flows into the main cavity (101) of the power chamber (10) from the end away from the polishing chamber. The water flow impacts and pushes the bidirectional impeller (12) to move closer to the polishing chamber, thereby driving the spiral polishing mechanism (6) and the cavitation polishing disc (3) to move towards the bottom of the blind hole workpiece (2); During the movement of the spiral polishing mechanism (6), the miniature ultrasonic sensor (5) on the spiral polishing mechanism (6) continuously emits sound waves to detect whether there is a step effect on the inner surface of the blind hole. When the control center (26) receives the signal that the miniature ultrasonic sensor (5) first detects the step effect, the control center (26) controls the second signal trigger water outlet (19) located on the side closer to the polishing chamber to open, and the control center (26) controls the second infrared emitter (14) located on the side farther from the polishing chamber to open. The second infrared emitter (14) emits infrared signals in real time. The control center (26) controls the first high-pressure nozzle (131) corresponding to the infrared receiving module that receives the infrared signal to open, that is, the first high-pressure nozzle (131) facing the bidirectional impeller (12) opens. As the bidirectional impeller (12) moves closer to the polishing chamber, the first high-pressure nozzle (131) opens sequentially in the direction closer to the polishing chamber. The bidirectional impeller (12) rotates, driving the spiral polishing mechanism (6) and the cavitation polishing disc (3) to rotate. The cavitation rotating jet generated by the abrasive liquid at the cavitation nozzle (65) polishes the inner surface of the blind hole. When the delayed pressure sensor (303) detects contact with the bottom surface of the blind hole, the control center (26) controls the electromagnetic baffle (309) to be energized, the rotating plate (308) is attached to the electromagnetic baffle (309), the spray hole (301) and the conical hole (302) are connected, and the abrasive liquid generates a cavitation rotating jet at the conical hole (302) to polish the bottom surface of the blind hole; After the set time is reached, the control center (26) controls the closing of the second high-pressure nozzle (132) that is furthest from the polishing chamber, and the opening of the second high-pressure nozzle (132) that is closest to the polishing chamber. The second infrared emitter (14) and the second signal trigger water outlet (19) are closed, and the first infrared emitter (11) and the first signal trigger water outlet (18) located on the side away from the polishing chamber are opened, so that the bidirectional impeller (12) moves and rotates to the side away from the polishing chamber, and performs secondary repolishing on the inner surface of the blind hole. The miniature ultrasonic sensor (5) continuously monitors the quality of the inner surface of the blind hole. If the inner surface quality is still defective, the moving direction of the bidirectional impeller (12) is changed to repeat the above polishing steps to polish the inner surface of the blind hole. If the inner surface of the blind hole is detected to be smooth and even, after the spiral polishing mechanism (6) moves to the outside of the blind hole workpiece (2), the abrasive liquid in the polishing chamber and the water in the power chamber (10) are discharged and recycled, and then all devices are turned off.

9. The cavitation jet polishing method for the stepped effect on the inner surface of blind holes according to claim 8, characterized in that, The blind hole workpiece (2) is clamped and positioned inside the left cavity (1) of the polishing chamber by the fixing fixture (4). The hollow shaft (17) is inserted into the polishing chamber close to the blind hole workpiece (2). The spiral polishing mechanism (6) and the cavitation polishing disc (3) are installed on the hollow shaft (17) by threaded connection. Then, the left cavity (1) of the polishing chamber and the right cavity (7) of the polishing chamber are connected by the sealing groove, and the polishing chamber is assembled. The control center (26) controls the first one-way hydraulic pump (20) and the third one-way hydraulic pump (30) to shut down, and controls the inlet and second outlet of the three-position four-way solenoid directional valve (24) to connect, and the second one-way hydraulic pump (23) to open. The residual abrasive liquid in the polishing chamber passes through the polishing chamber-filter (25)-three-position four-way solenoid directional valve (24)-second one-way hydraulic pump (23)-abrasive liquid tank (21) in sequence to clean and recycle the residual abrasive liquid in the polishing chamber; the control center controls the first signal to trigger the water outlet. (18) and the second signal triggers the water outlet (19) to open, control the two-position four-way solenoid valve (29) to be in the right position, connect the second medium outlet and medium inlet of the two-position four-way solenoid valve (29), and control the change of the delivery direction of the bidirectional hydraulic pump (28) so that the water at the water outlet below the power chamber (10) is delivered to the water tank (27), thereby causing the water in the power chamber (10) to flow back to the water tank (27), thereby realizing the discharge and recycling of the abrasive liquid in the polishing chamber and the water in the power chamber (10).

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