Ultrasonic nondestructive testing system and method for internal defects of outer cylinder of hydraulic support

Abstract

The present invention belongs to the technical field of ultrasonic nondestructive testing, and relates to an ultrasonic nondestructive testing system and method for internal defects of the outer cylinder of a hydraulic support. The ultrasonic nondestructive testing system includes a front support assembly, an intermediate transmission assembly, a rear support assembly, and a detection assembly of modular design; the intermediate transmission assembly is arranged between the front support assembly and the rear support assembly, the detection device is arranged on the intermediate transmission assembly, the circumferential stepper motor is used to drive the intermediate transmission assembly to rotate circumferentially, the axial stepper motor controls the movement of the transmission base on the intermediate transmission assembly, the transmission base is provided with an ultrasonic probe detection assembly, and two stepper motors control the movement of the ultrasonic probe to complete the detection of the outer cylinder of the hydraulic support. The modular concept is adopted to avoid interference between the various components, and to facilitate the improvement and upgrading of the equipment in the future; the position of the small disc base is controlled by rotating the nut, so as to realize different opening and closing angles of the support legs in the support assembly, and realize the detection of hydraulic cylinders of different diameters.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic nondestructive testing, and in particular relates to an ultrasonic nondestructive testing system and method for internal defects of an outer cylinder of a hydraulic support. Background Art

[0002] As the main energy source in my country, coal will remain the stabilizer and ballast of my country's energy security for a long period of time in the future. Therefore, it is very important to ensure the high yield, high efficiency and safe production of coal. Coal mining machinery plays an important role in achieving high yield, high efficiency and comprehensive mechanized coal mining.

[0003] The hydraulic support has the characteristics of large support area, high strength and high working pressure. It can effectively support and control the roof of the working face, provide safe working space for workers to operate and fully-mechanized mining equipment to operate, and is one of the main equipment of fully-mechanized mining working face. As the main load-bearing component, the outer cylinder of the hydraulic support is very easy to expand its internal congenital defects under the action of external periodic pressure. In severe cases, it will cause the cylinder weld to crack and even cause the cylinder to explode, affecting the support characteristics and bringing safety hazards. In order to ensure the reliability of the hydraulic support, it is necessary to test the hydraulic support cylinder.

[0004] Ultrasonic testing is currently the most widely used non-destructive testing method and has been widely used in all walks of life. The outer cylinder of the hydraulic support works in a dusty and humid environment all year round. The anti-rust paint on the surface falls off, and the rust causes the surface to be uneven. In addition, the external force damage and structural deformation make the surface uneven. If the ultrasonic probe is arranged on the outer surface, it is difficult for the ultrasonic wave and the outer surface of the cylinder to couple well, which affects the incident effect of the ultrasonic wave and the detection result is inaccurate. Therefore, the ultrasonic probe can only be placed inside the cylinder body and the detection is carried out from the inner surface of the cylinder body. At present, most manual A-type ultrasonic flaw detectors are used for the detection of the outer cylinder of the hydraulic support. This detection method has problems such as low detection efficiency and detection accuracy, poor repeatability and reliability, and no records. In addition, the detection results are affected by the subjective factors of the detection personnel, which may lead to problems such as missed detection. Therefore, an ultrasonic non-destructive detection system for internal defects of the outer cylinder of the hydraulic support is invented to realize the automation and visualization of detection. Summary of the invention

[0005] The technical problems to be solved by the present invention are:

[0006] The present invention provides an ultrasonic nondestructive detection system for internal defects of the outer cylinder of a hydraulic support, which is used to solve the difficult problem of quality detection of the outer cylinder of a hydraulic support, overcome the shortcomings and deficiencies of the manual ultrasonic A-scan detection method, improve the reliability and efficiency of ultrasonic detection, realize the digitization, automation and visualization of cylinder detection, ensure the reliability and safety of the operation of the hydraulic support, and further ensure the safety and normal production of the coal mine.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A system for ultrasonic nondestructive testing of internal defects of an outer cylinder of a hydraulic support, the system comprising a front support assembly, an intermediate transmission assembly, a rear support assembly and a detection assembly of modular design; the front support assembly and the rear support assembly have the same overall structure and are symmetrically mounted at both axial ends of the intermediate transmission assembly to support the intermediate transmission assembly; the detection assembly is fixedly mounted on the intermediate transmission assembly, and is driven and controlled by a driving module to perform linear motion or rotational motion to complete the detection of the outer cylinder of the hydraulic support.

[0009] A further technical solution of the present invention is that the front bracket assembly includes: a large disc base, a small disc base, a bracket leg, a roller, a connecting rod, a trapezoidal screw, a screw nut, and a nut seat; the large disc base is circumferentially equipped with a plurality of bracket legs, the inner ends of the bracket legs are connected to the large disc base, and the outer ends of the bracket legs are equipped with rollers, which are connected to one end of the connecting rod near the inner ends of the bracket legs, and the other end of the connecting rod is connected to the small disc base; the trapezoidal screw passes through the small disc base and cooperates with the central threaded hole of the large disc base, and the small disc base is sleeved on the trapezoidal screw to form a clearance fit, the screw nut and the trapezoidal screw are adapted and abutted against the outer end of the small disc base, which is limited by the screw nut, and the nut seat is fixed to one end of the trapezoidal screw, and a threaded hole is reserved on the right side of the nut seat; adjusting the screw nut pushes the small disc base to move along the trapezoidal screw, thereby adjusting the opening and closing angles of the bracket legs to adapt to hydraulic support outer cylinders of different diameters.

[0010] A further technical solution of the present invention is: the intermediate transmission assembly includes: a fixed base, a synchronous belt, a driving module, a pulley, a sliding rod, a transmission base, an axial motor base, a circumferential motor base, and a fastener; wherein the fixed base includes a left fixed base and a right fixed base; the left fixed base and the right fixed base are connected by a sliding rod; the driving module includes an axial motor and a circumferential motor, the circumferential motor base is connected to the nut seat of the front bracket assembly by screws, the circumferential motor is fixedly installed on the circumferential motor base, and the output shaft of the circumferential motor is connected to the left fixed base by key fitting;

[0011] The axial motor base is fixed on the left fixed base, the axial motor is fixedly installed on the axial motor base, a left pulley is installed on the output shaft of the axial motor, and a right pulley is installed on the right fixed base, the left pulley and the right pulley have the same parameters, and the synchronous belt is sleeved on the left pulley and the right pulley; the transmission base is sleeved on the sliding rod, and the synchronous belt is fixed to the transmission base by fasteners, and the axial motor drives the transmission base to move through the pulley and the synchronous belt; the right fixed base is connected to the rear bracket assembly through a rolling bearing.

[0012] A further technical solution of the present invention is: the circumferential motor and the axial motor are stepper motors, and the axis of the circumferential motor is arranged to coincide with the central axis of the outer cylinder of the hydraulic support.

[0013] A further technical solution of the present invention is: the system also includes: a stepper motor controller, which is used to control the step length, speed and rotation angle of the circumferential motor and the axial motor.

[0014] A further technical solution of the present invention is: the detection component includes an ultrasonic probe and a telescopic rod, the telescopic rod is vertically fixed to the center position of the transmission base, the top of the telescopic rod is connected to the ultrasonic probe, and the ultrasonic probe moves axially and circumferentially around the central axis of the outer cylinder of the hydraulic support along with the transmission base.

[0015] A further technical solution of the present invention is that the left end of the trapezoidal screw in the rear bracket assembly can be interference-fitted with the rolling bearing arranged in the right fixed base after processing.

[0016] A further technical solution of the present invention is: the number of the support legs is three, the three support legs are evenly distributed along the circumference of the outer edge of the large disc base, and a 60-degree bend angle is set at the end of one-third of the support legs.

[0017] A further technical solution of the present invention is that the ultrasonic probe is an ultrasonic water spray probe.

[0018] The embodiment of the present invention also provides a method for ultrasonic nondestructive testing of internal defects of an outer cylinder of a hydraulic support, the steps of which are as follows:

[0019] Step 1: Select the front support assembly, intermediate transmission assembly, rear support assembly and detection assembly of corresponding sizes according to the diameter and axial length of the outer cylinder of the hydraulic support, and then complete the installation of the entire detection system assembly;

[0020] Step 2: After the assembly of the detection component is completed, adjust the position of the screw nut in the front bracket assembly to fix the small disc base, adjust the degree of opening and closing of the bracket legs in the front bracket assembly, and then push the adjusted front bracket assembly into the outer cylinder of the hydraulic bracket; then adjust the length of the telescopic rod on the transmission base, and ensure that the ultrasonic probe reaches a suitable detection position when adjusting the telescopic rod; then adjust the rear bracket assembly to the same opening and closing angle as the front bracket assembly, and push the entire device into the outer cylinder of the hydraulic bracket;

[0021] Step 3: Set the circumferential motor motion control parameters, calculate and process the parameters, send corresponding control commands to the stepper motor controller, control the step length and speed of the circumferential motor, and let the ultrasonic probe rotate clockwise to perform a circle detection. After each circumferential step, the digital ultrasonic flaw detector collects ultrasonic data and transmits the data to the computer;

[0022] Step 4: Set the motion parameters of the axial motor, control the axial motor to move one step through the stepper motor controller, and then keep it still. The circumferential motor controls the probe to rotate counterclockwise for one circle. After each circumferential step, the digital ultrasonic flaw detector collects ultrasonic data and transmits the data to the computer. The axial motor then moves one step.

[0023] Step 5, repeat steps 3 and 4 in a reciprocating cycle until the axial motor controls the ultrasonic probe to move to the end of the outer cylinder of the hydraulic support, completing the detection of the entire outer cylinder of the hydraulic support, and finally generating ultrasonic B and C scanning images by the detection software on the computer.

[0024] Beneficial Effects

[0025] Compared with the prior art, the ultrasonic nondestructive detection system and method for internal defects of the outer cylinder of the hydraulic support proposed in the present invention have the following beneficial effects:

[0026] 1. The ultrasonic nondestructive detection system for internal defects of the outer cylinder of the hydraulic support provided by the present invention adopts a modular concept and independently designs the front and rear support components, the intermediate transmission components, the detection components and the interfaces between them, so as to avoid interference between the components and provide convenience for future improvement and upgrading of the equipment.

[0027] 2. The ultrasonic nondestructive detection system for internal defects of the outer cylinder of a hydraulic support provided by the present invention is provided with a trapezoidal screw and a screw nut to form a threaded fit, and the position of the small disc base is controlled by rotating the screw nut, so as to realize different opening and closing angles of the support legs in the support assembly. The 60-degree bending angle set at the end of the third of the support leg can reduce the length of the entire support assembly in the axial direction. Compared with two support legs of the same length, the support leg with a bending angle can detect pipes of larger sizes, and can realize the detection of the outer cylinders of hydraulic supports with different diameters.

[0028] 3. The ultrasonic nondestructive detection system for internal defects of the outer cylinder of the hydraulic support provided by the present invention uses the front and rear support components as fulcrums at both ends to support the intermediate transmission component. This structural layout can ensure the stability of the detection system during the detection process.

[0029] 4. The ultrasonic nondestructive detection system for internal defects of the outer cylinder of a hydraulic support provided by the present invention comprises two stepper motors, one circumferential motor is used to drive the intermediate transmission assembly to rotate circumferentially, and the other axial motor is used to drive the synchronous belt in the intermediate transmission assembly. The transmission base is fixed on the synchronous belt to realize the axial stepping motion of the transmission base. The stepper motor controller controls the rotation of the two motors to realize the full detection of the cylinder by the probe, avoids the entanglement of the probe, water pipe, etc., and facilitates the detection process.

[0030] 5. The ultrasonic nondestructive testing system for internal defects of the outer cylinder of the hydraulic support provided by the present invention adopts an ultrasonic water spray probe and uses water as a coupling agent, which is more convenient and economical. The ultrasonic probe is located on the telescopic rod to realize ultrasonic B and C scanning imaging. The telescopic rod can be extended and retracted according to the cylinders to be tested with different diameters, ensuring that the ultrasonic probe at the top of the telescopic rod maintains a suitable detection distance with the inner wall of the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope of protection of the present invention.

[0032] Figure 1 It is a structural schematic diagram of an ultrasonic nondestructive detection system for internal defects of an outer cylinder of a hydraulic support of the present invention;

[0033] Figure 2 It is an assembly diagram of a front support component of an ultrasonic nondestructive testing system for internal defects of an outer cylinder of a hydraulic support of the present invention;

[0034] Figure 3 It is a schematic diagram of a large disc base of an ultrasonic nondestructive testing system for internal defects of an outer cylinder of a hydraulic support of the present invention;

[0035] Figure 4 The invention is a local enlargement of an ultrasonic nondestructive detection system for internal defects of an outer cylinder of a hydraulic support. Figure 1 ;

[0036] Figure 5 The invention is a local enlargement of an ultrasonic nondestructive detection system for internal defects of an outer cylinder of a hydraulic support. Figure 2 ;

[0037] Figure 6 It is an assembly diagram of an intermediate transmission component of an ultrasonic nondestructive testing system for internal defects of an outer cylinder of a hydraulic support of the present invention;

[0038] Figure 7 The invention is a local enlargement of an ultrasonic nondestructive detection system for internal defects of an outer cylinder of a hydraulic support. Figure 3 ;

[0039] Figure 8 The invention is a local enlargement of an ultrasonic nondestructive detection system for internal defects of an outer cylinder of a hydraulic support. Figure 4 ;

[0040] Fig. 9 It is an assembly diagram of a rear support component of an ultrasonic nondestructive testing system for internal defects of an outer cylinder of a hydraulic support of the present invention.

[0041] In the figure: 1 roller, 2 bracket leg, 3 connecting rod, 4 small disc base, 5 circumferential motor, 6 fixed base, 7 sliding rod, 8 ultrasonic probe, 9 telescopic rod, 10 transmission base, 11 nut seat, 12 lead screw nut, 13 trapezoidal lead screw, 14 large disc base, 15 synchronous belt, 16 fastener, 17 pulley, 18 axial motor, 19 axial motor base, 20 circumferential motor base, 21 rolling bearing. DETAILED DESCRIPTION

[0042] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] An ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support, such as Figure 1-9 As shown, the system includes a front support assembly, an intermediate transmission assembly, a rear support assembly and a detection assembly.

[0045] The front bracket assembly includes: a large disc base 14, a small disc base 4, a bracket leg 2, a roller 1, a connecting rod 3, a trapezoidal screw 13, a screw nut 12, and a nut seat 11; the intermediate transmission assembly includes: a fixed base 6, a synchronous belt 15, an axial motor 18, a circumferential motor 5, a pulley 17, a sliding rod 7, a transmission base 10, an axial motor base 19, a circumferential motor base 20, and a fastener 16; the detection assembly includes an ultrasonic probe 8 and a telescopic rod 9.

[0046] In the front bracket assembly, the large disc base 14 and the small disc base 4 are connected by a trapezoidal screw 13. The large disc base 14 is fixed together with the trapezoidal screw 13 by threaded cooperation, and the small disc base 4 forms a clearance cooperation with the trapezoidal screw 13. Three bracket legs 2 are installed on the circumference of the large disc base 14. The three bracket legs 2 are connected to the small disc base 4 by connecting rods 3. The small disc base 4 is pushed to move by adjusting the screw nut 12. The position of the small disc base 4 is directly related to the opening angle of the bracket legs 2. When the bracket legs 2 are opened to a suitable angle, the screw nut 12 is adjusted to fix them. The screw nut 12 and the trapezoidal screw 13 are matched and abutted against the outer end of the small disc base 4, which is limited by the screw nut 12. The nut seat 11 is fixed to one end of the trapezoidal screw 13. A threaded hole is reserved on the right side of the nut seat 11, which is convenient for the circumferential motor base 20 to be connected to the nut seat 11 by screws. When the front bracket assembly is connected to the intermediate transmission assembly, the circumferential motor base 20 is first fixed to the nut seat 11, and then the circumferential motor 5 is placed on the circumferential motor base 20; the circumferential motor 5 controls the rotation of the intermediate transmission assembly by key matching. After processing, the trapezoidal screw 13 of the rear bracket assembly can be directly fixed and installed with the rolling bearing 21 in the right fixed base 6, for example, an interference fit can be set.

[0047] An axial motor 18 is installed on the fixed base 6 at one end of the intermediate transmission assembly. The axial motor 18 drives the synchronous belt 15 to rotate, and the transmission base 10 is fixed on the synchronous belt 15 and is sleeved on the slide bar 7, so that the axial motor 18 drives the synchronous belt 15 to realize the axial movement of the transmission base 10. The transmission base 10 is installed with a telescopic rod 9 of the detection assembly in the center. The telescopic rod 9 stands vertically on the transmission base 10, and an ultrasonic probe 8 is placed on the top of the telescopic rod 9; the front bracket assembly is connected to the intermediate transmission assembly, and the rear bracket assembly is connected to the intermediate transmission assembly through the processed trapezoidal screw 13. The rotation of the two motors drives the ultrasonic probe 8 to reach every place on the inner wall of the cylinder body for detection.

[0048] This detection system adopts a modular concept. The front and rear bracket assemblies and the intermediate transmission assemblies are all independently designed. When faced with hydraulic support outer cylinders of different sizes, it is first necessary to select front and rear bracket assemblies, intermediate transmission assemblies and detection assemblies of different sizes according to the diameter and axial length of the hydraulic support outer cylinder, and then complete the installation of the entire detection assembly.

[0049] After the assembly of the to-be-detected components is completed, adjust the position of the screw nut 12 in the front bracket assembly to fix the small disc base 4, adjust the degree of opening of the bracket legs 2 in the front bracket assembly, and then push the adjusted front bracket assembly into the outer cylinder of the hydraulic bracket. Then adjust the length of the telescopic rod 9 on the transmission base 10. Since the top of the telescopic rod 9 is connected to the ultrasonic probe 8, it is necessary to ensure that the ultrasonic probe 8 reaches the appropriate detection position when adjusting the telescopic rod 9. Then adjust the rear bracket assembly to the same opening and closing angle as the front bracket assembly, and push the entire device into the outer cylinder of the hydraulic bracket.

[0050] After the entire device enters the outer cylinder of the hydraulic support, the movement of the two stepper motors is controlled so that the ultrasonic probe 8 reciprocates in a circumferential and then axial motion mode. That is, the motion control parameters of the circumferential motor 5 are set first, and the parameters are calculated and processed, and the corresponding control commands are sent to the stepper motor controller to control the step length and speed of the circumferential motor 5, so that the probe performs a clockwise detection of a circle. During this process, the axial motor 18 does not move. After completing a circle of detection, the motion parameters of the axial motor 18 are set, and the axial motor 18 is controlled by the stepper motor controller to move a step length, and then the stationary state is maintained. The circumferential motor 5 controls the ultrasonic probe 8 to rotate counterclockwise for one circle, and the axial motor 18 moves a step length again, and reciprocates in this way. When the axial motor 18 controls the ultrasonic probe 8 to move to the end of the outer cylinder of the hydraulic support, the ultrasonic probe 8 completes the detection of the entire outer cylinder of the hydraulic support.

[0051] In ultrasonic imaging, the detection software is developed based on the LabWindows / CVI environment. According to the modular design concept, modules such as sound field simulation, motion control, data acquisition, data processing, ultrasonic scanning imaging, and system management are designed to realize ultrasonic B and C scanning imaging. After adjusting the telescopic rod 9 on the transmission base 10, it is necessary to ensure that the probe on the telescopic rod 9 maintains a suitable measuring distance with the inner wall of the outer cylinder of the hydraulic support. After the entire detection assembly enters the outer cylinder of the hydraulic support, adjust the gain of the digital ultrasonic flaw detector to ensure that the bottom echo wave height reaches 80% of the full screen scale. After adjusting the appropriate gain as the scanning sensitivity, the ultrasonic A scanning signal is measured. After controlling the step length and speed of the circumferential motor 5 to detect the inner wall of the outer cylinder of the hydraulic support in a clockwise circle, the ultrasonic B scanning image is measured. After the ultrasonic probe 8 scans the inner wall of the outer cylinder of the hydraulic support in a circle, the axial motor is controlled to move a step length, and the detection position of the probe on the outer cylinder of the hydraulic support changes at the same time. Then the circumferential motor 5 is controlled to obtain a new circle of B scanning images in the outer cylinder of the hydraulic support in a counterclockwise direction, and the ultrasonic C scanning of the inner wall of the outer cylinder of the hydraulic support is finally completed. By analyzing the ultrasonic C and B scanning images, the location of the defect in the outer cylinder of the hydraulic support is determined.

[0052] The ultrasonic nondestructive testing system of the present application is used to conduct actual experimental operation test on the internal defects of the outer cylinder of the hydraulic support, and the method steps are as follows:

[0053] Step 1: Select different detection components according to the diameter and axial length of the outer cylinder of the hydraulic support, and then complete the installation of the entire detection component;

[0054] Step 2: After the assembly of the detection component is completed, adjust the position of the screw nut 12 in the front bracket assembly to fix the small disc base 4, adjust the opening degree of the bracket leg 2 in the front bracket assembly, and then push the adjusted front bracket assembly into the outer cylinder of the hydraulic bracket; then adjust the length of the telescopic rod 9 on the transmission base 10, and ensure that the ultrasonic probe 8 reaches a suitable detection position when adjusting the telescopic rod 9; then adjust the rear bracket assembly to the same opening and closing angle as the front bracket assembly, and push the entire device into the outer cylinder of the hydraulic bracket;

[0055] Step 3: Set the motion control parameters of the circumferential motor 5, calculate and process the parameters, send corresponding control commands to the stepper motor controller, control the step length and speed of the circumferential motor 5, and let the ultrasonic probe 8 perform a circle detection clockwise. After each circumferential step, the digital ultrasonic flaw detector collects ultrasonic data and transmits the data to the computer.

[0056] Step 4, setting the motion parameters of the axial motor 18, controlling the axial motor 18 to move one step through the stepper motor controller, and then keeping still, the circumferential motor 5 controls the ultrasonic probe 8 to rotate counterclockwise for one circle, and the digital ultrasonic flaw detector collects ultrasonic data once after completing one circumferential step, and transmits the data to the computer, and the axial motor 18 moves another step;

[0057] Step 5, repeat steps 3 and 4, and repeat this process repeatedly. When the axial motor 18 controls the ultrasonic probe 8 to move to the end of the outer cylinder of the hydraulic support, the ultrasonic probe 8 completes the detection of the entire outer cylinder of the hydraulic support, and finally the detection software on the computer generates ultrasonic B and C scanning images.

[0058] The present invention adopts a modular concept to avoid interference between various components, thus facilitating future improvements and upgrades to the equipment. The position of the small disc base is controlled by rotating the screw nut to achieve the opening and closing of the bracket legs in the bracket assembly. Different opening and closing angles can realize the detection of hydraulic cylinders of different diameters, thereby realizing the automation and visualization of internal defect detection of the outer cylinder body.

[0059] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. An ultrasonic nondestructive testing system for internal defects of an outer cylinder of a hydraulic support, characterized by: The ultrasonic nondestructive testing system comprises a front support assembly, an intermediate transmission assembly, a rear support assembly and a detection assembly of modular design; the front support assembly and the rear support assembly have the same overall structure and are symmetrically mounted at both axial ends of the intermediate transmission assembly to support the intermediate transmission assembly; the detection assembly is fixedly mounted on the intermediate transmission assembly, and the detection assembly is driven and controlled by a driving module to perform linear motion or circumferential rotational motion to complete the detection of the outer cylinder of the hydraulic support; The front bracket assembly comprises: a large disc base, a small disc base, a bracket leg, a roller, a connecting rod, a trapezoidal screw, a screw nut, and a nut seat; the large disc base is circumferentially provided with a plurality of bracket legs, the inner ends of the bracket legs are connected to the large disc base, and rollers are installed at the outer ends of the bracket legs, which are connected to one end of the connecting rod near the inner ends of the bracket legs, and the other end of the connecting rod is connected to the small disc base; the trapezoidal screw passes through the small disc base and cooperates with the central threaded hole of the large disc base, and the small disc base is sleeved on the trapezoidal screw to form a clearance fit, and the screw nut and the trapezoidal screw are adapted and abutted against the outer end of the small disc base, which is limited by the screw nut, and the nut seat is fixed to one end of the trapezoidal screw, and a threaded hole is reserved on the right side of the nut seat; adjusting the screw nut pushes the small disc base to move along the trapezoidal screw, thereby adjusting the opening and closing angles of the bracket legs to adapt to the outer cylinder bodies of hydraulic supports of different diameters; The intermediate transmission assembly includes: a fixed base, a synchronous belt, a driving module, a pulley, a sliding rod, a transmission base, an axial motor base, a circumferential motor base, and a fastener; wherein the fixed base includes a left fixed base and a right fixed base; the left fixed base and the right fixed base are connected by a sliding rod; the driving module includes an axial motor and a circumferential motor, the circumferential motor base is connected to the nut seat of the front bracket assembly by screws, the circumferential motor is fixedly installed on the circumferential motor base, and the output shaft of the circumferential motor is connected to the left fixed base by key fitting The side fixed base; the axial motor base is fixed on the left fixed base, the axial motor is fixedly installed on the axial motor base, the output shaft of the axial motor is installed with a left pulley, the right pulley is installed on the right fixed base, the left pulley and the right pulley are selected with the same parameters, the synchronous belt is sleeved on the left pulley and the right pulley; the transmission base is sleeved on the sliding rod, the synchronous belt is fixed to the transmission base by fasteners, and the axial motor drives the transmission base to move through the pulley and the synchronous belt; the right fixed base is connected to the rear bracket assembly through a rolling bearing; The detection assembly comprises an ultrasonic probe and a telescopic rod. The ultrasonic probe is vertically fixed to the center position of the transmission base through the telescopic rod. The ultrasonic probe moves axially and circumferentially around the center axis of the outer cylinder of the hydraulic support along with the transmission base.

2. According to claim 1, the ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support is characterized by: After processing, the left end portion of the trapezoidal screw in the rear bracket assembly is interference-fitted with a rolling bearing arranged in the right fixed base.

3. The ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support according to claim 1 is characterized by: The circumferential motor and the axial motor are stepper motors, and the axis of the circumferential motor is arranged to coincide with the central axis of the outer cylinder of the hydraulic support.

4. The ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support according to claim 3 is characterized by: The system further comprises: a stepper motor controller for controlling the step length, speed and rotation angle of the circumferential motor and the axial motor.

5. The ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support according to claim 1 is characterized by: The number of the support legs is three, and the three support legs are evenly distributed along the circumference of the outer edge of the large disc base, and the end third of the support legs is configured to form a 60-degree bend angle.

6. The ultrasonic nondestructive testing system for internal defects of the outer cylinder of a hydraulic support according to claim 1 is characterized by: The ultrasonic probe is an ultrasonic water jet probe.

7. A method for detecting internal defects of an outer cylinder of a hydraulic support by using an ultrasonic nondestructive detection system according to any one of claims 1 to 6, comprising the following steps: Step 1: Select the front support assembly, intermediate transmission assembly, rear support assembly and detection assembly of corresponding sizes according to the diameter and axial length of the outer cylinder of the hydraulic support, and then complete the installation of the entire detection system assembly; Step 2: After the assembly of the detection component is completed, adjust the position of the screw nut in the front bracket assembly to fix the small disc base, adjust the degree of opening and closing of the bracket legs in the front bracket assembly, and then push the adjusted front bracket assembly into the outer cylinder of the hydraulic bracket; then adjust the length of the telescopic rod on the transmission base, and ensure that the ultrasonic probe reaches a suitable detection position when adjusting the telescopic rod; then adjust the rear bracket assembly to the same opening and closing angle as the front bracket assembly, and push the entire device into the outer cylinder of the hydraulic bracket; Step 3: Set the circumferential motor motion control parameters, calculate and process the parameters, send corresponding control commands to the stepper motor controller, control the step length and speed of the circumferential motor, and let the ultrasonic probe rotate clockwise to perform a circle detection. After each circumferential step, the digital ultrasonic flaw detector collects ultrasonic data and transmits the data to the computer; Step 4: Set the motion parameters of the axial motor, control the axial motor to move one step through the stepper motor controller, and then keep it still. The circumferential motor controls the probe to rotate counterclockwise for one circle. After each circumferential step, the digital ultrasonic flaw detector collects ultrasonic data and transmits the data to the computer. The axial motor then moves one step. Step 5, repeat steps 3 and 4 in a reciprocating cycle until the axial motor controls the ultrasonic probe to move to the end of the outer cylinder of the hydraulic support, completing the detection of the entire outer cylinder of the hydraulic support, and finally generating ultrasonic B and C scanning images by the detection software on the computer.

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