Friction plug repair welding system

Abstract

The application discloses a friction plug repair welding system, comprising a friction plug repair welding spindle head device with adsorption function and a tool holder, wherein the friction plug repair welding spindle head device comprises a rotary reciprocating oil cylinder, the output shaft of the rotary reciprocating oil cylinder can simultaneously perform axial linear reciprocating motion and rotary motion, and the tool holder is fixed on the output shaft of the rotary reciprocating oil cylinder; the tool holder comprises a tool holder body, a lock nut and a split fastening sleeve; the friction plug repair welding system has high integration and high automation level, can realize integrated operation of defect removal and repair welding of a workpiece to be welded, and can significantly improve the efficiency and reliability of in-situ repair of the workpiece to be welded.

Description

Technical Field

[0001] This invention belongs to the field of friction plug repair welding technology, specifically relating to a friction plug repair welding spindle head device with adsorption function, a method for adjusting the positioning and bonding accuracy of the friction plug repair welding spindle head device, and a friction plug repair welding system. Background Technology

[0002] Rocket propellant tanks are core components of launch vehicles, serving not only as fuel containers for storing propellants such as liquid oxygen and liquid hydrogen, but also as critical load-bearing structures within the rocket body. The structural integrity and sealing performance of rocket propellant tanks have a significant impact on flight safety, and welding defects or service damage are inevitable during manufacturing and service. To ensure the structural integrity and service safety of the propellant tanks, effective repair of localized defects is necessary.

[0003] Friction plug welding, as a solid-state welding process, has the advantages of low heat input, small post-weld deformation, and high degree of automation. It does not require a support structure on the back of the propellant tank, making it particularly suitable for repairing defects in large, thin-walled, hollow structural components such as rocket propellant tanks.

[0004] However, the rocket propellant tank has complex surface curvature variations and irregular welding positions, making it difficult to provide a stable and uniform positioning reference. Due to the influence of the curved surface morphology and spatial attitude, the friction plug welding spindle head is prone to poor local contact or relative slippage with the surface of the workpiece during the welding process. This is not conducive to the stable application of torque and axial load during the welding process, and will affect the stability of the friction plug welding process and the forming quality of the weld joint. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a friction plug welding spindle head device with adsorption function.

[0006] Another objective of this invention is to provide a method for adjusting the positioning and fitting accuracy of a friction plug welding spindle head device.

[0007] Another objective of this invention is to provide a friction plug repair welding system, which has a high degree of integration and automation, and can realize the integrated operation of defect removal and repair welding of the workpiece to be welded, which can significantly improve the efficiency and reliability of in-situ repair of the workpiece to be welded.

[0008] The present invention is achieved through the following technical solution.

[0009] A friction plug welding spindle head device with adsorption function includes: a friction plug welding spindle head and a machine head device. The machine head device includes: a support frame and M vacuum suction cups. The support frame is fixedly mounted to the friction plug welding spindle head. A through hole is formed on the support frame. The through hole is opposite to the position of the friction plug welding spindle head for installing the plug rod.

[0010] M vacuum suction cups are mounted on the support frame. The M vacuum suction cups include: a ring suction cup group and an X-type suction cup group. The ring suction cup group includes M1 vacuum suction cups. The M1 vacuum suction cups of the ring suction cup group are arranged in a circular direction with the center of the through hole as the center.

[0011] The X-type suction cup assembly includes: a first suction cup assembly and a second suction cup assembly. Each of the first and second suction cup assemblies includes M2 vacuum suction cups. The M2 vacuum suction cups in the first suction cup assembly are arranged in an inverted trapezoidal shape. The second suction cup assembly and the first suction cup assembly are symmetrically arranged with the center of the through hole on a horizontal straight line.

[0012] In the above technical solution, the M1 vacuum suction cups of the annular suction cup group are evenly distributed around the through hole, and M1 = 8~16.

[0013] In the above technical solution, M2 = 4~8, and the M2 vacuum suction cups in the first suction cup group are located at the four corners of the inverted trapezoid.

[0014] In the above technical solution, each vacuum suction cup is connected to a vacuum generator, and each vacuum suction cup is equipped with a vacuum sensor for real-time monitoring of the vacuum level.

[0015] In the above technical solution, the support frame includes a suction cup frame and a support frame. The suction cup frame and the friction plug welding spindle head are spaced apart. The suction cup frame is fixed to the friction plug welding spindle head through the support frame. The through hole is located on the suction cup frame, and M vacuum suction cups are all installed on the suction cup frame.

[0016] In the above technical solution, the suction cup holder has a curved surface structure.

[0017] In the above technical solution, M suction cup bases are fixedly mounted on the suction cup frame, and each suction cup base is connected to a vacuum suction cup through a universal joint.

[0018] In the above technical solution, the head assembly also includes: an industrial camera, two small-range laser rangefinders and four large-range laser rangefinders. The industrial camera, two small-range laser rangefinders and four large-range laser rangefinders are all fixed on the side of the suction cup frame away from the friction plug welding spindle head. The two small-range laser rangefinders are fixed on both sides of the through hole with the horizontal straight line where the center of the through hole is located as the axis of symmetry. The four large-range laser rangefinders are arranged in a rectangular array on the suction cup frame.

[0019] In the above technical solution, the distance between each small-range laser range sensor and the center of the through hole is 50~150mm.

[0020] In the above technical solution, a large-range laser ranging sensor is fixedly mounted at each of the four corners of the suction cup holder.

[0021] In the above technical solution, the range of the small-range laser rangefinder is 0.1 to 10 mm, and the range of the large-range laser rangefinder is 40 to 400 mm.

[0022] The method of using the friction plug repair welding spindle head device with adsorption function includes: adsorbing the friction plug repair welding spindle head device onto the outer surface of the workpiece to be welded by the vacuum suction cup of the machine head device, and performing friction plug repair welding.

[0023] A method for adjusting the positioning and fitting accuracy of a friction plug repair welding spindle head device includes the following steps:

[0024] Step 1: Use an industrial camera to capture the outline of the defects on the surface of the workpiece to be welded, and obtain an image of the outline. Extract the pixel coordinates of several feature points of the outline in the pixel coordinate system. Calculate the pixel coordinates of the center of the outline based on the pixel coordinates of the feature points. Convert the pixel coordinates of the center of the outline into the corresponding coordinates in the world coordinate system. The Z-axis direction of the world coordinate system is the same as the normal direction of the center of the defect outline.

[0025] Step 2: Bring the friction plug welding spindle head device with adsorption function close to the workpiece to be welded until the outer surface of the workpiece is within the range of the large-range laser range sensor. Align the center coordinates of the friction plug welding spindle head with the center of the defect contour in the XY plane of the world coordinate system. Calculate the pitch angle of the friction plug welding spindle head device based on the four large-range laser range sensors. and yaw angle Adjust the rotation angle of the friction plug welding spindle head assembly to adjust its pitch angle. and yaw angle To get as close to 0 as possible, so that the axial direction of the friction plug welding spindle head coincides with the normal direction of the center of the defect contour;

[0026] Step 3: Further bring the friction plug welding spindle head device close to the workpiece to be welded and make it fit the outer surface of the workpiece. Make the M vacuum suction cups on the suction cup frame initially fit the outer surface of the workpiece. Start the vacuum generator so that the friction plug welding spindle head device is adsorbed onto the outer surface of the workpiece. Perform the judgment method, which includes the following steps:

[0027] S1, calculate the ranging values ​​of the two small-range laser rangefinders;

[0028] S2, if the distance values ​​of both small-range laser range sensors are less than the distance threshold, the vacuum suction cup is well attached to the outer surface of the workpiece to be welded, and the judgment method ends; if the distance value of any small-range laser range sensor is greater than or equal to the distance threshold, then proceed to S3.

[0029] S3, turn off the vacuum generator, adjust the angle of the friction plug welding spindle head device until γ is close to 0 at its maximum, adjust the friction plug welding spindle head device and then turn on the vacuum generator so that the friction plug welding spindle head device is re-adsorbed onto the outer surface of the workpiece to be welded; repeat S1~S2.

[0030] in, The two small-range laser rangefinders are a first small-range laser rangefinder and a second small-range laser rangefinder. S1 is the ranging value measured by the first small-range laser rangefinder, and S2 is the ranging value measured by the second small-range laser rangefinder. The difference between the ranging values ​​of the two small-range laser rangefinders is given by denoted by denoted by D, which is the installation distance between the two small-range laser rangefinders.

[0031] Step 4: Determine the adsorption state of the individual vacuum suction cup connected to each vacuum sensor: If the vacuum sensor detects that the absolute pressure of the vacuum degree of its corresponding vacuum suction cup is greater than the absolute pressure of the preset vacuum degree, adjust the adsorption angle of the vacuum suction cup until the absolute pressure of the vacuum degree of the vacuum suction cup is less than or equal to the absolute pressure of the preset vacuum degree.

[0032] In S2, the distance threshold is 0.2~1.2mm.

[0033] In step 4, the absolute pressure of the preset vacuum level is 0.3~0.5 bar.

[0034] A friction plug repair welding system includes: a friction plug repair welding spindle head device with adsorption function and a tool holder. The friction plug repair welding spindle head includes: a rotary reciprocating cylinder, the output shaft of which can simultaneously perform axial linear reciprocating motion and rotary motion, and the tool holder is fixedly mounted on the output shaft of the rotary reciprocating cylinder.

[0035] The knife handle includes: the knife handle body, a lock nut, and a separate fastening sleeve, wherein:

[0036] The split fastening sleeve includes two fasteners, each of which includes an arc-shaped fastening part, an upper protrusion and a lower protrusion. The arc-shaped fastening part is a semi-circular arc surface. When the two fasteners are engaged, the arc-shaped fastening parts of the two fasteners form a ring column structure.

[0037] The upper and lower protrusions of each fastener are arranged along the axial direction of the annular structure and fixed to the outer ring surface of the annular structure.

[0038] One end of the tool holder body serves as the first connecting end, which is used to weld the spindle head to the friction plug for fixation. The other end of the tool holder body serves as the second connecting end, which has a blind hole. The shape of the blind hole is adapted to the outer contour of the split fastening sleeve when the two fasteners are engaged. The split fastening sleeve after the two fasteners are engaged is located in the blind hole. The axial length of the split fastening sleeve is adapted to the axial length of the blind hole. The upper and lower protrusions are used to prevent the split fastening sleeve from rotating in the blind hole. The annular columnar structure formed by the arc-shaped fastening parts of the two fasteners has an internal thread. The annular columnar structure is used to accommodate the cutting tool or the stopper bar, and is connected to the cutting tool or the stopper bar through its internal thread.

[0039] The lock nut has a cylindrical cavity inside. One end of the lock nut has an opening, and the other end has a mounting hole. The lock nut fits over the second connecting end of the tool holder body through the opening and is threaded to the second connecting end. The shape of the mounting hole is the same as the cross-sectional shape of the outer contour of the split fastening sleeve when the two fasteners are engaged, and the shape of the mounting hole is slightly larger than the cross-sectional shape of the outer contour of the split fastening sleeve. When the lock nut is rotated until the shape of the mounting hole is opposite to the cross-section of the outer contour of the split fastening sleeve, the split fastening sleeve can pass through the mounting hole of the lock nut. When the lock nut is rotated until the shape of the mounting hole is not opposite to the cross-section of the outer contour of the split fastening sleeve, the lock nut limits the split fastening sleeve to the blind hole.

[0040] In the above technical solution, the annular columnar structure is divided into two sections along its axial direction: one section is a threaded section composed of internal threads, and the other section is a smooth section.

[0041] In the above technical solution, a groove is formed on the bottom of the blind hole. The bottom of the groove is connected to one end of a compression spring, and the other end of the compression spring is connected to a spring washer. When the annular structure contains a cutting tool or a stopper, the compression spring and the spring washer are pressed into the groove, and the compression spring applies a thrust toward the outside of the blind hole to the corresponding cutting tool or stopper through the spring washer.

[0042] The method of using the friction plug repair welding system includes: first, following the "positioning and bonding accuracy adjustment method," and then following the "use of the tool holder in friction plug repair welding." The specific steps for using the tool holder in friction plug repair welding are as follows:

[0043] Step 1: Align the two fasteners so that their arc-shaped fastening parts form a ring-shaped structure. Place the split-type fastening sleeve into the blind hole of the tool holder body. Then tighten the lock nut on the tool holder body. At this time, the shape of the mounting hole is not opposite to the cross-section of the outer contour of the split-type fastening sleeve. The split-type fastening sleeve is limited in the blind hole by the lock nut. Screw the tool into the ring-shaped structure and connect it with the internal thread. The friction plug welding spindle head installs the tool through the tool holder. The friction plug welding spindle head enlarges the hole of the workpiece to be welded through the tool to form a plug hole. After forming the plug hole, rotate the tool and remove the tool from the ring-shaped structure.

[0044] Step 2: Screw the stopper rod into the annular structure and connect it with the internal thread. Use the friction plug welding spindle head with the stopper rod installed to perform friction plug welding on the plug hole. After the friction plug welding is completed, the end of the stopper rod away from the tool holder is now welded to the plug hole. Rotate the lock nut until the shape of the mounting hole is opposite to the cross section of the outer contour of the split fastening sleeve. The friction plug welding spindle head drives the tool holder to move away from the plug hole along its axis. Under the pushing force of the spring washer on the stopper rod, the split fastening sleeve moves out of the blind hole along with the stopper rod through the mounting hole. At this time, the stopper rod is removed from the tool holder body. Separate the two fasteners on the stopper rod directly and remove them from the stopper rod.

[0045] The beneficial effects of this invention are as follows:

[0046] 1. The vacuum suction cups in the friction plug welding spindle head device of this invention, which features an adsorption function, are arranged in a structure of annular suction cup group + X-type suction cup group. This allows the head device to form a reliable adsorption connection with the surface of the workpiece to be welded, achieving integrated fixation of the head device and the workpiece. This facilitates the stable transmission of torque and axial load during the friction plug welding process, reducing welding instability caused by severe vibrations resulting from the contact friction between the plug rod and the workpiece. This improves the stability of the friction plug welding process and the consistency of the weld joint performance. Simultaneously, this method reduces reliance on manual adjustments and complex rigid support structures, significantly improving the feasibility and engineering adaptability of welding operations on complex curved surfaces.

[0047] 2. The positioning and fitting accuracy adjustment method of the friction plug welding spindle head device of this invention reduces the number of alignment steps during friction plug welding, simplifies the operation process, and reduces the impact of manual intervention and human error on welding quality, which is beneficial to improving the positioning efficiency and assembly consistency of friction plug welding. Simultaneously, by maintaining the coaxial consistency between defect removal and friction plug welding processes, the stress distribution and friction stability during welding can be effectively improved, enhancing welding quality and joint reliability, providing strong support for the automation and engineering application of friction plug welding of workpieces. Through the synergistic effect of an industrial camera and a laser rangefinder sensor, combined with robotic arm motion control and vacuum suction cup fixation, automatic defect identification, precise positioning, and reliable adsorption are achieved, significantly improving the accuracy and quality of defect removal and friction plug welding processes.

[0048] 3. The tool holder of this invention has a compact structure and is easy to operate. Through the reasonable structural cooperation between the tool holder body, the split fastening sleeve and the lock nut, high-precision positioning, reliable clamping and quick disassembly of the tool and the stopper are achieved, which can meet the needs of quick interchange of tool and stopper during defect removal and friction plug repair welding.

[0049] This invention relates to a friction plug repair welding system that combines a tool holder and a friction plug repair welding spindle head device with adsorption function. This integrates the two key stages of defect removal and friction plug repair welding into a single system, requiring only one alignment process. This not only saves time, enabling automatic positioning and adsorption fixation in a very short time, but also improves accuracy. The deviation between the rotation center of the rotary reciprocating cylinder and the center of the plug hole can be controlled at the micrometer level, and the angular deviation between the axis of the rotary reciprocating cylinder and the normal to the plug hole is controlled within an extremely small angle range. Under adsorption fixation, the relative displacement between the head device and the outer surface of the workpiece is maintained at the sub-millimeter level. This invention not only significantly improves positioning efficiency and accuracy but also enhances the stability of the friction plug repair welding process and the quality of the welded joint, meeting the engineering repair needs for high precision and high consistency of the workpiece. Attached Figure Description

[0050] Figure 1 This is a left view of the friction plug welding spindle head device with adsorption function of the present invention.

[0051] Figure 2 This is a three-dimensional structural schematic diagram of the friction plug welding spindle head device with adsorption function according to the present invention.

[0052] Figure 3 This is a front view of the friction plug welding spindle head device with adsorption function of the present invention;

[0053] Figure 4 This is a schematic diagram of four light spots projected onto the outer surface of the workpiece to be welded by four large-range laser range sensors (the surface of the workpiece to be welded).

[0054] Figure 5 To calculate the pitch angle middle Measurement diagram;

[0055] Figure 6 To calculate the yaw angle middle Measurement diagram;

[0056] Figure 7 for A schematic diagram of the calculation;

[0057] Figure 8 This is a cross-sectional view of a rotary reciprocating hydraulic cylinder.

[0058] Figure 9 This is a three-dimensional structural diagram of the knife handle of the present invention;

[0059] Figure 10 This is a schematic diagram of the split-type fastening sleeve of the present invention;

[0060] Figure 11 This is a schematic diagram of the assembly of the tool holder body and the split fastening sleeve of the present invention;

[0061] Figure 12 This is a cross-sectional view of the tool holder of the present invention;

[0062] Figure 13 This is a side view of the fastener of the present invention;

[0063] Figure 14 This is a three-dimensional structural diagram of the lock nut of the present invention;

[0064] Figure 15 This is a cross-sectional view of the lock nut of the present invention;

[0065] Figure 16 This is a schematic diagram of the structure of the knife handle body of the present invention;

[0066] Figure 17 This is a schematic diagram of the spindle head repair device for friction plug welding in Comparative Example 1;

[0067] Figure 18 The diagram shows (a) the torque and (b) the axial force of the friction plug welding spindle head during the friction plug welding process using the friction plug welding spindle head device of Embodiment 3 and Comparative Example 1.

[0068] Figure 19 The diagram shows the sampling locations of (a) the metallographic specimen and the tensile specimen in the welded joint specimen, and the structural diagrams of (b) the metallographic specimen and (c) the tensile specimen.

[0069] Figure 20 (a) Metallographic image of the metallographic specimen and (b) Stress-strain curve of the tensile specimen.

[0070] Wherein, 1: tool holder, 1-1: tool holder body, 1-1-1: external thread, 1-2: lock nut, 1-2-1: mounting hole, 1-3: split fastening sleeve, 1-3-1: fastener, 1-3-1-1: internal thread, 1-3-1-2: smooth section, 1-4: spring washer, 1-5: shock-absorbing washer, 1-6: flange;

[0071] 2: Friction plug repair welding spindle head, 2-1: Mandrel, 2-2: Piston rod, 2-3: Housing, 2-4: Ring part, 2-5: First space, 2-6: Second space, 2-7: First oil port, 2-8: Second oil port, 2-9: Bearing, 2-10: Mounting groove, 2-11: Air passage;

[0072] 3: Head assembly; 3-1: Suction cup holder; 3-2: Vacuum suction cup; 3-3: Small-range laser rangefinder sensor; 3-4: Industrial camera; 3-5: Large-range laser rangefinder sensor; 3-6: Support frame. Detailed Implementation

[0073] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0074] Example 1

[0075] A friction plug welding head repair device with adsorption function, such as Figures 1-3 As shown, it includes: a friction plug welding spindle head 2 and a machine head device 3. The friction plug welding spindle head 2 is fixedly mounted to an attitude control component (the attitude control component can be a robotic arm, not shown in the figure). The machine head device 3 includes: a support frame and M vacuum suction cups 3-2 (in this embodiment, M=16). The support frame is fixedly mounted to the friction plug welding spindle head 2. A through hole is formed on the support frame. The through hole is opposite to the position of the friction plug welding spindle head 2 for installing the plug rod (after the plug rod is installed on the friction plug welding spindle head 2, the plug rod can pass through the through hole).

[0076] M vacuum suction cups 3-2 are mounted on the support frame. The M vacuum suction cups 3-2 include: an annular suction cup group and an X-shaped suction cup group. The annular suction cup group includes M1 vacuum suction cups 3-2. The M1 vacuum suction cups 3-2 of the annular suction cup group are arranged in a circumferential direction with the center of the through hole as the center. In this embodiment, M1=8, and the M1 vacuum suction cups 3-2 of the annular suction cup group are evenly distributed around the through hole.

[0077] The X-type suction cup group includes: a first suction cup group and a second suction cup group. Each of the first and second suction cup groups includes M2 vacuum suction cups 3-2. In the first suction cup group, the M2 vacuum suction cups 3-2 are arranged along an inverted trapezoid (an inverted trapezoid is a trapezoid whose upper base is longer than its lower base), M2=4. The M2 vacuum suction cups 3-2 in the first suction cup group are located at the four corners of the inverted trapezoid. The second suction cup group and the first suction cup group are symmetrically arranged with the center of the through hole on a horizontal straight line. The X-type suction cup group can enhance the overall adsorption force and stability of the vacuum suction cups 3-2. The annular suction cup group can form a uniform adsorption force field. When the friction plug welding spindle head device is used to perform friction plug welding on the workpiece to be welded, the annular suction cup group and the X-type suction cup group work together to achieve stable contact between the head device 3 and the outer surface of the workpiece to be welded.

[0078] Each vacuum suction cup 3-2 is connected to a vacuum generator (in this embodiment, every two vacuum suction cups 3-2 share one vacuum generator), and each vacuum suction cup 3-2 is equipped with a vacuum sensor for real-time monitoring of the vacuum level.

[0079] The method of using the friction plug welding spindle head device with adsorption function includes: adsorbing the friction plug welding spindle head device onto the outer surface of the workpiece to be welded by the vacuum suction cup 3-2 of the head device 3, and performing friction plug welding.

[0080] Example 2

[0081] A friction plug welding spindle head device with adsorption function, based on embodiment 1, includes a support frame comprising: a suction cup frame 3-1 and a support frame 3-6. The suction cup frame 3-1 is spaced apart from the friction plug welding spindle head 2. The suction cup frame 3-1 is fixedly mounted to the friction plug welding spindle head 2 through the support frame 3-6. A through hole is located on the suction cup frame 3-1, and M vacuum suction cups 3-2 are all mounted on the suction cup frame 3-1.

[0082] The suction cup holder 3-1 has a curved surface structure. Different suction cup holders 3-1 with different curvature radii can be replaced according to the curvature of the workpiece to be welded, so that the suction cup holder 3-1 matches the workpiece to be welded.

[0083] M suction cup bases are fixed on the suction cup frame 3-1. Each suction cup base is connected to a vacuum suction cup 3-2 through a universal joint. The contact angle between the vacuum suction cup 3-2 and the outer surface of the workpiece to be welded can be adjusted by manually operating the universal joint, so that the vacuum suction cup 3-2 can adapt to the slight differences in the curvature of the workpiece at different positions, thereby improving the contact effect.

[0084] The support frame 3-6 is made of Q345 low-alloy high-strength structural steel. The support frame 3-6 is a truss-type welded structure, which is composed of four transverse beams and several longitudinal reinforcing ribs connected at intersections. The external outline dimensions of the support frame 3-6 are 450mm×420mm×350mm, and the internal cavity dimensions of the support frame 3-6 are 420mm×260mm×200mm (the internal cavity dimensions are the three-dimensional dimensions of the cavity enclosed by the transverse beams and longitudinal reinforcing ribs), which facilitates the loading, unloading and replacement of components such as cutting tools and stoppers.

[0085] Example 3

[0086] A friction plug welding head device with adsorption function, based on Example 2, such as... Figure 2 and Figure 3 As shown, the head assembly 3 also includes: an industrial camera 3-4, two small-range laser rangefinders 3-3 and four large-range laser rangefinders 3-4. The industrial camera 3-4, the two small-range laser rangefinders 3-3 and the four large-range laser rangefinders 3-4 are all fixedly mounted on the side of the suction cup frame 3-1 away from the friction plug welding spindle head 2. Among them, the two small-range laser rangefinders 3-3 are fixedly mounted on both sides of the through hole with the horizontal straight line where the center of the through hole is located as the axis of symmetry. The distance between each small-range laser rangefinder 3-3 and the center of the through hole is 50~150mm, which is 150mm in this embodiment.

[0087] At each of the four corners of the suction cup holder 3-1, a large-range laser range sensor 3-4 is fixedly mounted, and the four large-range laser range sensors 3-4 are arranged in a rectangular array on the suction cup holder 3-1.

[0088] The range of the small-range laser rangefinder 3-3 is 0.1 to 10 mm, and the range of the large-range laser rangefinder 3-4 is 40 to 400 mm.

[0089] Comparative Example 1

[0090] A friction plug welding spindle head device is basically the same as the friction plug welding spindle head device with adsorption function in Example 3. The only difference is that the number of vacuum chucks 3-2 is 4 (M=4). The 4 vacuum chucks 3-2 are arranged in a rectangle and are fixed on the four corners of the chuck frame 3-1 (staggered from the large-range laser range sensor 3-4).

[0091] Example 4

[0092] For curved workpieces to be welded, the positioning and fixing of the friction plug welding spindle head often relies on manual adjustment or rigid support. However, this method is highly dependent on installation accuracy and operator experience. Therefore, this application also designs a method for adjusting the positioning and fitting accuracy of the friction plug welding spindle head device.

[0093] The method for adjusting the positioning and fitting accuracy of the friction plug repair welding spindle head device in Example 3 or Comparative Example 1 includes the following steps:

[0094] Step 1: The contour of the surface defect of the workpiece to be welded is acquired by industrial camera 3-4 (in this embodiment, the field of view of industrial camera 3-4 is the detection area of ​​the surface of the workpiece to be welded, which is 800mm×400mm). The contour image is obtained, and the pixel coordinates of several feature points of the contour in the pixel coordinate system are extracted. The pixel coordinates of the center of the contour are calculated based on the pixel coordinates of the feature points. The pixel coordinates of the center of the contour are converted into the corresponding coordinates in the world coordinate system. The Z-axis direction of the world coordinate system is the same as the normal direction of the center of the defect contour.

[0095] Step 2: Bring the friction plug welding spindle head device with adsorption function close to the workpiece to be welded until the outer surface of the workpiece is within the range of the large-range laser range sensor 3-4. Ensure that the center coordinates (in the world coordinate system) of the friction plug welding spindle head 2 and the center of the defect contour coincide in the XY plane of the world coordinate system (two small-range laser range sensors 3-3 are set along the height direction (vertical direction)). Calculate the pitch angle of the friction plug welding spindle head device based on the four large-range laser range sensors 3-4. and yaw angle Adjust the rotation angle of the friction plug welding spindle head assembly to adjust its pitch angle. and yaw angle To get as close to 0 as possible, so that the axial direction of the friction plug welding spindle head 2 coincides with the normal direction of the center of the contour;

[0096] Step 3: Further bring the friction plug welding spindle head device close to the workpiece to be welded and make it fit the outer surface of the workpiece. Make the M vacuum suction cups 3-2 on the suction cup frame 3-1 initially fit with the outer surface of the workpiece. Start the vacuum generator so that the friction plug welding spindle head device is adsorbed onto the outer surface of the workpiece. Perform the judgment method, which includes the following steps:

[0097] S1, calculate the ranging values ​​of the two small-range laser rangefinders 3-3;

[0098] S2, if the distance values ​​of both small-range laser rangefinders 3-3 are less than the distance threshold (the distance threshold is 0.2~1.2mm, and in this embodiment the distance threshold is 1mm), then the vacuum suction cup 3-2 fits well with the outer surface of the workpiece to be welded, and the judgment method ends; if the distance value of any small-range laser rangefinder 3-3 is greater than or equal to the distance threshold, then proceed according to S3.

[0099] S3, turn off the vacuum generator, adjust the angle of the friction plug welding spindle head device until γ is close to 0 at its maximum, adjust the friction plug welding spindle head device and then turn on the vacuum generator so that the friction plug welding spindle head device is re-adsorbed onto the outer surface of the workpiece to be welded; repeat S1~S2.

[0100] in, ,like Figure 7 As shown, the two small-range laser rangefinders 3-3 are the first and second small-range laser rangefinders, S1 is the ranging value measured by the first small-range laser rangefinder, and S2 is the ranging value measured by the second small-range laser rangefinder. denoted as the difference between the ranging values ​​of the two small-range laser rangefinders 3-3, and D is the installation distance between the two small-range laser rangefinders 3-3.

[0101] Step 4: Based on each vacuum sensor, determine the adsorption state of the individual vacuum suction cup 3-2 connected to it: If the vacuum sensor detects that the absolute pressure of the vacuum degree of its corresponding vacuum suction cup 3-2 is greater than the absolute pressure of the preset vacuum degree (the absolute pressure of the preset vacuum degree is 0.3~0.5 bar, and in this embodiment it is 0.4 bar), then (manually operate the universal joint) adjust the adsorption angle of the vacuum suction cup 3-2 to increase the suction force between the vacuum suction cup 3-2 and the outer surface of the workpiece to be welded, until the absolute pressure of the vacuum degree of the vacuum suction cup 3-2 is less than or equal to the absolute pressure of the preset vacuum degree.

[0102] The positioning and fitting accuracy adjustment method of this invention is used to automatically identify and accurately visually center the defect position. In the subsequent defect removal and friction plug repair welding process, a vacuum suction cup is used to fix the machine head device 3 and the workpiece to be welded into one, so that the positional relationship of the workpiece to be welded relative to the friction plug repair welding spindle head device remains unchanged throughout the defect removal and friction plug repair welding process.

[0103] Example 5

[0104] Based on Example 4, the four large-range laser range sensors 3-4 are a first large-range laser range sensor, a second large-range laser range sensor, a third large-range laser range sensor, and a fourth large-range laser range sensor, as follows: Figure 4 As shown, the four light spots projected onto the outer surface of the workpiece by the first large-range laser range sensor, the second large-range laser range sensor, the third large-range laser range sensor, and the fourth large-range laser range sensor are light spots P1, P2, P3, and P4, respectively. Light spot P1 is located above light spot P3, light spot P2 is located above light spot P4, light spot P1 is located to the left of light spot P2, and light spot P3 is located to the left of light spot P4.

[0105] Calculate pitch angle The method includes the following steps:

[0106] 1) Calculation , and :

[0107] ,like Figure 5 As shown;

[0108] ;

[0109] ;

[0110] ;

[0111] Where L1 is the ranging value measured by the first large-range laser rangefinder, L2 is the ranging value measured by the second large-range laser rangefinder, L3 is the ranging value measured by the third large-range laser rangefinder, and L4 is the ranging value measured by the fourth large-range laser rangefinder. The distance between light spots P1 and P3 is... The distance between light spots P1 and P4 is... The distance between light spots P2 and P3. The distance between light spot P2 and light spot P4;

[0112] 2) Calculate the pitch angle :

[0113] .

[0114] Calculate yaw angle The method includes the following steps:

[0115] 1) Calculation , and :

[0116] ,like Figure 6 As shown;

[0117] ;

[0118] ;

[0119] ;

[0120] Where L1 is the ranging value measured by the first large-range laser rangefinder, L2 is the ranging value measured by the second large-range laser rangefinder, L3 is the ranging value measured by the third large-range laser rangefinder, and L4 is the ranging value measured by the fourth large-range laser rangefinder. The distance between light spots P1 and P2 is... The distance between light spots P1 and P4 is... The distance between light spots P2 and P3. The distance between light spot P3 and light spot P4;

[0121] 2) Calculate the yaw angle :

[0122] .

[0123] Example 6

[0124] In the technical solution of the present invention, the friction plug welding spindle head 2 includes: a rotary reciprocating cylinder, and a tool holder fixed on the output shaft of the rotary reciprocating cylinder; the rotary reciprocating cylinder can be a commercially available product in the prior art, as long as the output shaft of the rotary reciprocating cylinder can perform axial linear reciprocating motion and rotary motion simultaneously.

[0125] In this embodiment, the structure of the rotary reciprocating hydraulic cylinder is as follows: Figure 8As shown, the rotary reciprocating cylinder includes: a spindle 2-1, a piston rod 2-2, and a housing 2-3. A cylindrical cavity is formed inside the housing 2-3. The piston rod 2-2 is located within the cylindrical cavity and is coaxially arranged with it. A closed annular cylindrical space is formed between the piston rod 2-2 and the inner wall of the cylindrical cavity. An annular component 2-4 (integrated with the piston rod 2-2) is connected to the piston rod 2-2 and is coaxially arranged with it. The annular component 2-4 is located within the annular cylindrical space and divides the annular cylindrical space into two non-communicating spaces: a first space 2-5 and a second space 2-6 (both the first space 2-5 and the second space 2-6 are annular). The first space 2-5 corresponds to the housing 2-1. A first oil port 2-7 is formed on the shell 2-3 corresponding to the second space 2-6, and a second oil port 2-8 is formed on the shell 2-3. When a medium is introduced into the first oil port 2-7, the annular member 2-4 moves axially and reduces the volume of the second space 2-6 (increases the volume of the first space 2-5), and the medium in the second space 2-6 is discharged from the second oil port 2-8. Conversely, when a medium is introduced into the second oil port 2-8, the annular member 2-4 moves axially and reduces the volume of the first space 2-5 (increases the volume of the second space 2-6), and the medium in the first space 2-5 is discharged from the first oil port 2-7. During the change in the volume of the first space 2-5 and the second space 2-6, the annular member 2-4 drives the piston rod 2-2 to move axially. A channel with open end faces is formed inside the piston rod 2-2 (the channel axis is the same as the piston rod 2-2 axis). A cylindrical cavity is formed inside the channel. The spindle 2-1 is located inside the cylindrical cavity and is coaxially arranged with it. Two bearings 2-9 are installed between the spindle 2-1 and the inner wall of the cylindrical cavity. One end of the spindle 2-1 serves as the output shaft of the rotary reciprocating cylinder (the output shaft of the rotary reciprocating cylinder has a mounting groove 2-10) and extends out of the piston rod 2-2. The motor is fixedly mounted on the piston rod 2-2, and the motor output shaft is fixedly mounted to the other end of the spindle 2-1. The working principle of the above-mentioned rotary reciprocating cylinder is as follows: The motor output shaft drives the spindle 2-1 to rotate (the piston rod 2-2 does not rotate), thereby realizing the rotational motion of the output shaft of the rotary reciprocating cylinder. At the same time, if the output shaft of the rotary reciprocating cylinder needs to perform axial linear reciprocating motion, the piston rod 2-2 moves along its axial direction and simultaneously drives the spindle 2-1 to perform axial motion by alternately introducing medium into the first oil port 2-7 and the second oil port 2-8.

[0126] like Figure 8 As shown, an air passage 2-11 is formed on the side wall of the cylindrical cavity. This air passage is connected to an external air pump, which can deliver high-pressure gas into the air passage 2-11 to achieve internal protection and prevent metal debris from entering the piston rod 2-2 during defect removal and friction plug repair welding.

[0127] Example 7

[0128] Under current technological conditions, pull-out friction plug repair welding is a solid-state welding process. In this process, the repair welding typically includes two key stages: defect removal and friction plug repair welding. To ensure welding quality, when using conventional machining tools (tools or U-drills) for defect removal, the defect must first be located, and the rotation center of the tool must be precisely aligned with the defect center to ensure that the position and geometric accuracy of the resulting plug hole meet the subsequent repair welding requirements. However, after defect removal, due to local material removal, stress release, and minor deformations caused by the machining process, the formed plug hole will shift in spatial position or orientation relative to the original defect reference. Therefore, after the plug rod is assembled, the relative position between the plug rod and the plug hole needs to be repositioned and aligned to ensure that the rotation center of the plug rod remains highly consistent with the center of the machined plug hole, thus meeting the stringent assembly accuracy requirements of friction plug welding. In the prior art, the alignment processes of the two key stages—defect removal and friction plug repair welding—are usually independent and largely rely on manual visual inspection, experience-based judgment, or simple measurement methods. However, the complex surface curvature of the workpiece to be welded and the limited space for welding positions make it difficult to perform high-precision alignment of the plug hole after defect removal. This process is not only cumbersome and time-consuming, but also highly dependent on the operator's experience. Any deviation in the secondary alignment can easily lead to insufficient coaxiality between the plug rod and the plug hole, resulting in uneven contact, unbalanced load distribution, and unstable friction during welding, thus affecting the weld quality and even causing repair welding failure. This operation method, requiring repeated positioning and multiple manual interventions, severely restricts the efficiency and consistency of pull-out friction plug repair welding in the repair of workpieces.

[0129] Furthermore, stopper rods are typically connected to tool holders via threads. However, this connection method leaves the stopper rod and tool holder still connected after the stopper repair welding is completed. For large workpieces like rocket propellant tanks, effective separation is difficult, posing significant challenges to subsequent processes. To address this, this application designs a tool holder that allows for the sequential mounting of the tool and stopper rod. It also integrates defect removal and friction stopper repair welding processes onto the same rotary reciprocating cylinder, significantly improving repair efficiency and reducing instability caused by equipment switching and repeated clamping.

[0130] like Figures 9-16 As shown, a knife handle includes: a knife handle body 1-1, a lock nut 1-2, and a split-type fastening sleeve 1-3 (the hardness of the knife handle body 1-1, the lock nut 1-2, and the split-type fastening sleeve 1-3 is HRC58~60), wherein:

[0131] like Figure 10As shown, the split fastening sleeve 1-3 includes: two fasteners 1-3-1, each fastener 1-3-1 including an arc-shaped fastening part, an upper protrusion and a lower protrusion. The arc-shaped fastening part is a semi-circular arc surface. When the two fasteners 1-3-1 are engaged, the arc-shaped fastening parts of the two fasteners 1-3-1 form a ring column structure.

[0132] The upper and lower protrusions of each fastener 1-3-1 are arranged along the axial direction of the annular column structure and fixed to the outer ring surface of the annular column structure. Preferably, when the arc-shaped fastening portions of the two fasteners 1-3-1 form an annular column structure, the upper protrusions of the two fasteners 1-3-1 are in contact, and the lower protrusions of the two fasteners 1-3-1 are in contact (in this embodiment, both the upper and lower protrusions are cuboid in shape, the width of both the upper and lower protrusions is 10-12 mm, the height is 5-6 mm, and the surface roughness Ra≤1.6 μm).

[0133] One end of the tool holder body 1-1 serves as the first connecting end, which is used for fixing the spindle head 2 to the friction plug for welding (the first connecting end has a cylindrical structure and is installed in the mounting groove 2-10 formed on the output shaft of the rotary reciprocating cylinder, as shown in the mounting groove 2-10). Figure 8 As shown), the other end of the tool holder body 1-1 serves as the second connecting end, which has a blind hole. The shape of the blind hole matches the outer contour of the split fastening sleeve 1-3 when the two fasteners 1-3-1 are engaged. After the two fasteners 1-3-1 are engaged, the split fastening sleeve 1-3 is located inside the blind hole (when the split fastening sleeve 1-3 is in the blind hole, the two fasteners 1-3-1 are limited by the blind hole and always remain engaged). The axial length of the split fastening sleeve 1-3 matches the axial length of the blind hole, meaning that the split fastening sleeve 1-3 will not move axially in the blind hole after being inserted. The upper and lower protrusions are used to prevent the split fastening sleeve 1-3 from rotating in the blind hole (i.e., the split fastening sleeve 1-3 cannot rotate in the blind hole). Figure 12 and Figure 13 As shown, the annular structure formed by the arc-shaped fastening parts of the two fasteners 1-3-1 has an internal thread 1-3-1-1 inside, and the length of the internal thread 1-3-1-1 is 30-35mm; the annular structure is used to accommodate a cutting tool or a stopper rod, and is connected to the cutting tool or the stopper rod through its internal thread 1-3-1-1.

[0134] like Figure 12 As shown, a groove is formed on the bottom of the blind hole. The bottom of the groove is connected to one end of a compression spring, and the other end of the compression spring is connected to a spring washer 1-4. When the annular structure contains a cutting tool or a stopper, the compression spring and the spring washer 1-4 are pressed into the groove, and the compression spring applies a thrust toward the outside of the blind hole to the corresponding cutting tool or stopper through the spring washer 1-4.

[0135] The lock nut 1-2 has a cylindrical cavity inside, with an opening at one end and a mounting hole 1-2-1 at the other end (as shown). Figure 9 As shown, a shock-absorbing washer 1-5 is installed inside the wall of the mounting hole 1-2-1. The shock-absorbing washer 1-5 is made of a material with shock-absorbing and buffering properties, such as rubber. The shock-absorbing washer 1-5 can effectively absorb the vibration generated during the removal of cutting defects by the tool or the welding process of the stopper rod friction plug, and can also prevent welding defects or equipment damage caused by vibration. The lock nut 1-2 is fitted over the second connecting end of the tool holder body 1-1 through an open end and is threaded to the second connecting end (the second connecting end has an external thread 1-1-1). The shape of the mounting hole 1-2-1 and (two fasteners 1-3) (-1 When mated) The cross-sectional shape of the outer contour of the split fastening sleeve 1-3 is the same, and the shape of the mounting hole 1-2-1 is slightly larger than the cross-sectional shape of the outer contour of the split fastening sleeve 1-3. When the shape of the mounting hole 1-2-1 is aligned with the cross-section of the outer contour of the split fastening sleeve 1-3, the split fastening sleeve 1-3 can pass through the mounting hole 1-2-1 of the lock nut 1-2. When the shape of the mounting hole 1-2-1 is not aligned with the cross-section of the outer contour of the split fastening sleeve 1-3, the lock nut 1-2 limits the split fastening sleeve 1-3 in the blind hole.

[0136] like Figure 13 As shown, the annular structure is divided into two sections along its axial direction: one section is a threaded section consisting of internal threads 1-3-1-1, and the other section is a smooth section 1-3-1-2. The diameter of the smooth section 1-3-1-2 is 32-34 mm, and the surface roughness Ra≤1.6 μm.

[0137] like Figure 12 As shown, a flange 1-6 is fixedly mounted on the first connecting end of the tool holder body 1-1 for welding the spindle head 2 to the friction plug (the flange 1-6 is fixedly mounted to the spindle 2-1 in embodiment 6).

[0138] The specific steps for using a tool holder in friction plug repair welding are as follows:

[0139] Step 1: Align the two fasteners 1-3-1 so that their arc-shaped fastening parts form a ring-shaped structure. Place the split fastening sleeve 1-3 into the blind hole of the tool holder body 1-1. Then, tighten the locking nut 1-2 on the tool holder body 1-1. At this time, the shape of the mounting hole 1-2-1 is not opposite to the cross section of the outer contour of the split fastening sleeve 1-3. The split fastening sleeve 1-3 is limited in the blind hole by the locking nut 1-2. Screw the tool into the ring-shaped structure and thread it with the internal thread 1-3-1-1. The friction plug welding spindle head 2 installs the tool through the tool holder. The friction plug welding spindle head 2 enlarges the hole of the defect of the workpiece to be welded through the tool to form a plug hole. After forming the plug hole, rotate the tool and remove the tool from the ring-shaped structure.

[0140] Step 2: Screw the stopper rod into the annular structure and connect it to the internal thread 1-3-1-1. Use the friction plug welding spindle head 2 with the stopper rod installed to perform friction plug welding on the plug hole. After the friction plug welding is completed, the end of the stopper rod away from the tool holder is now welded onto the plug hole. Rotate the locking nut 1-2 until the shape of the mounting hole 1-2-1 is aligned with the cross-section of the outer contour of the split fastening sleeve 1-3. (Driven by the robotic arm) The friction plug welding spindle head 2 drives the tool holder axially away from the plug hole. During the movement, under the pushing force of the spring washer 1-4 on the stopper rod, the split fastening sleeve 1-3 moves out of the blind hole as the stopper rod passes through the mounting hole 1-2-1. At this time, the stopper rod is removed from the tool holder body 1-1, and the two fasteners 1-3-1 on the stopper rod are directly separated (no force is required, they can be separated directly) and removed from the stopper rod. At this time, the friction plug welding spindle head device is moved away from the plug hole (welded joint) where the stopper rod is welded, and the user has enough space to cut the remaining material of the stopper rod on the plug hole.

[0141] The tool holder of this invention reliably transmits torque and axial force during friction plug repair welding, ensuring stable movement of the plug rod. Simultaneously, after the friction plug repair welding is completed, it enables rapid separation of the plug rod from the tool holder, allowing the friction plug repair welding spindle head device to be promptly removed from the welding area. This significantly improves post-weld working space conditions, freeing the handling of the plug rod on the plug hole from the limitations of the friction plug repair welding spindle head device and its internal space. Users have sufficient space to cut off any remaining plug rod material on the plug hole, reducing the risk of weld joint damage and welding failure. This invention simplifies the post-weld disassembly process, improves operational efficiency, and reduces adverse effects on the weld joint while ensuring the quality of the friction plug repair weld. It provides reliable technical support for the engineering application of friction plug repair welding technology in large workpieces requiring welding.

[0142] Performance testing:

[0143] Install the tool holder on the friction plug welding spindle head device of Example 3 or Comparative Example 1, and then perform the "positioning and fitting accuracy adjustment method" in Example 4, followed by the "use of the tool holder in friction plug welding" (the plug rod material is 2219-T6 aluminum alloy, the workpiece material is 2219-T87 aluminum alloy, and the friction plug welding is a pull-out type). During the friction plug welding process, collect the torque and axial force of the output shaft of the rotary reciprocating cylinder. The results are as follows... Figure 18 (a) and Figure 18 As shown in (b), it can be seen that the friction plug repair welding spindle head device of Example 3 can significantly improve the stability of the rotary reciprocating cylinder during the friction plug repair welding process, significantly reduce the torque fluctuation amplitude, and more fully load the axial force. After the friction plug repair welding is completed, a cuboid-shaped workpiece to be welded is cut as a welding joint sample (the welding joint sample includes the workpiece to be welded and a frustum-shaped plug rod welded in the plug hole), as shown in Figure 3. Figure 19 As shown in (a).

[0144] The welded joint sample was divided into two parts. The first part was cut into a metallographic sample (the cross-sectional length of the metallographic sample was 80 mm and the height was 20 mm, and the cross-section of the metallographic sample was as follows). Figure 19 (as shown in (b)), the second piece is cut into the following pieces: Figure 19 The tensile specimen shown in (c) has a total length of 150 mm, a width of 10 mm for the parallel section, a length of 70 mm for the parallel section, a width of 20 mm for the clamping end, and a fillet radius of 25 mm. Both the tensile specimen and the metallographic specimen contain a stopper rod.

[0145] The metallographic structure of the metallographic specimens was tested according to GB / T 13298-2015 "Methods for Examination of Microstructure of Metals" for morphological comparison. Figure 20 As shown in (a). Figure 20 As shown in (a), in Comparative Example 1, the friction plug is used to repair the spindle head assembly (i.e., Figure 20 In the metallographic specimen obtained by the "four-corner suction cup arrangement" in (a), the stopper rod is deformed and defects appear at the welding interface. In the friction plug repair welding spindle head device of Example 3 (i.e. Figure 20 In the metallographic sample obtained by the "ring + X-type suction cup arrangement" in (a), the forming quality of the welded joint is significantly improved, the stopper rod is not deformed, and the welding interface defects disappear. This proves that compared with the friction plug welding spindle head device of Comparative Example 1, the friction plug welding spindle head device of Embodiment 3 of the present invention can significantly reduce the deformation of the stopper rod caused by welding vibration during the friction plug welding process, and the welding interface defects can be effectively eliminated.

[0146] Tensile specimens are subjected to tension to test their mechanical properties, such as... Figure 20 As shown in (b). Figure 20 As shown in (b), uniaxial tensile tests were conducted on the tensile specimens obtained in Example 3 and Comparative Example 1, respectively, at a tensile speed of 2 mm / min. The tensile strength of the tensile specimen in Example 3 was measured to be close to 350 MPa, and the tensile strength of the tensile specimen in Comparative Example 1 was close to 300 MPa. The tensile strength of the welded joint obtained by using the friction plug welding spindle head device of Example 3 of the present invention is higher, which proves that in the friction plug welding process, the friction plug welding spindle head device of Example 3 of the present invention can provide a stable support reference for the friction plug welding spindle head, making the posture of the friction plug welding spindle head stable, reducing the torque fluctuation amplitude, and making the axial force loading more sufficient and stable. This makes the friction heat generation more sufficient and uniform, further ensuring the close contact between the plug rod and the workpiece to be welded, effectively enhancing the welding heat generation and material flow behavior, and improving the welding effect.

[0147] pass Figure 20As can be seen, the structural arrangement of the annular suction cup group and the X-shaped suction cup group in the friction plug welding spindle head device of the present invention makes the entire suction cup array take the through hole on the support frame as the geometric center, forming a composite structure composed of a central annular distribution and an outer diagonal distribution. This ensures uniform adsorption in the central area of ​​the support frame and expands the overall support range. Specifically, the annular suction cup group can form a continuous and uniform adsorption ring around the through hole, providing a stable connection when the head device 3 adsorbs the outer surface of the workpiece to be welded, ensuring reliable adsorption in the central area; the X-shaped suction cup group extends the adsorption force along the diagonal direction, forming a mechanical support path from the center outward, effectively preventing the head device 3 from slipping, tilting, or locally detaching during friction plug welding or movement. The overall layout of the "ring-shaped suction cup group + X-shaped suction cup group" is symmetrical on the plane, so that the adsorption force vectors of the vacuum suction cups 3-2 are balanced and the resultant force always passes through the central axis of the head device 3, ensuring uniform force and stable posture. At the same time, the distance between the far ends of the vacuum suction cups 3-2 in the X-shaped suction cup group gradually increases, so that the outer edge vacuum suction cups 3-2 form a gradual distribution of density, which better adapts to the curvature changes or slight unevenness of the surface of the workpiece to be welded, and improves the adsorption coverage and adhesion reliability.

[0148] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A friction plug repair welding system, characterized in that, include: A friction plug welding spindle head device and tool holder (1) with adsorption function. The friction plug welding spindle head device includes: a friction plug welding spindle head (2) and a machine head device (3). The machine head device (3) includes: a support frame and M vacuum suction cups (3-2). The support frame is fixedly mounted to the friction plug welding spindle head (2). A through hole is formed on the support frame. The through hole is opposite to the position of the friction plug welding spindle head (2) for installing the plug rod. The M vacuum suction cups (3-2) are mounted on the support frame. The friction plug welding spindle head (2) includes: a rotary reciprocating cylinder, the output shaft of which can simultaneously perform axial linear reciprocating motion and rotary motion, and the tool holder (1) is fixed on the output shaft of the rotary reciprocating cylinder; The knife handle (1) includes: a knife handle body (1-1), a lock nut (1-2), and a split-type fastening sleeve (1-3), wherein: The split-type fastening sleeve (1-3) includes: two fasteners (1-3-1), each fastener (1-3-1) includes an arc-shaped fastening part, an upper protrusion and a lower protrusion. The arc-shaped fastening part is a semi-circular arc surface. When the two fasteners (1-3-1) are engaged, the arc-shaped fastening parts of the two fasteners (1-3-1) form a ring column structure. The upper and lower protrusions of each fastener (1-3-1) are arranged along the axial direction of the annular structure and fixed to the outer ring surface of the annular structure. One end of the tool holder body (1-1) serves as the first connecting end, which is used to fix the spindle head (2) to the friction plug for welding. The other end of the tool holder body (1-1) serves as the second connecting end, which has a blind hole. The shape of the blind hole is compatible with the outer contour of the split fastening sleeve (1-3) when the two fasteners (1-3-1) are engaged. The split fastening sleeve (1-3) after the two fasteners (1-3-1) are engaged is located in the blind hole. The axial length of the split fastening sleeve (1-3) is compatible with the axial length of the blind hole. The upper protrusion and the lower protrusion are used to prevent the split fastening sleeve (1-3) from rotating in the blind hole. The annular column structure formed by the arc-shaped fastening parts of the two fasteners (1-3-1) has an internal thread (1-3-1-1). The annular column structure is used to accommodate the cutting tool or the stopper rod, and is connected to the cutting tool or the stopper rod through its internal thread (1-3-1-1). The lock nut (1-2) has a cylindrical cavity inside. One end of the lock nut (1-2) has an opening, and the other end has a mounting hole (1-2-1). The lock nut (1-2) fits over the second connecting end of the tool holder body (1-1) through the opening and is threaded to the second connecting end. The shape of the mounting hole (1-2-1) is the same as the cross-sectional shape of the outer contour of the split fastening sleeve (1-3) when the two fasteners (1-3-1) are engaged, and the shape of the mounting hole (1-2-1) is different from that of the split fastening sleeve (1-3). 1-3) The cross-sectional shape of the outer contour is slightly larger. When the shape of the rotating lock nut (1-2) to the mounting hole (1-2-1) is opposite to the cross-section of the outer contour of the split fastening sleeve (1-3), the split fastening sleeve (1-3) can pass through the mounting hole (1-2-1) of the lock nut (1-2). When the shape of the rotating lock nut (1-2) to the mounting hole (1-2-1) is not opposite to the cross-section of the outer contour of the split fastening sleeve (1-3), the lock nut (1-2) limits the split fastening sleeve (1-3) in the blind hole.

2. The friction plug repair welding system according to claim 1, characterized in that, A groove is formed at the bottom of the blind hole. The bottom of the groove is connected to one end of a compression spring, and the other end of the compression spring is connected to a spring washer (1-4). When the annular structure contains a cutting tool or a stopper, the compression spring and the spring washer (1-4) are pressed into the groove, and the compression spring applies a thrust toward the outside of the blind hole to the corresponding cutting tool or stopper through the spring washer (1-4).

3. The friction plug repair welding system according to claim 1, characterized in that, M vacuum suction cups (3-2) include: a ring suction cup group and an X-type suction cup group. The ring suction cup group includes M1 vacuum suction cups (3-2). The M1 vacuum suction cups (3-2) of the ring suction cup group are arranged in a circular direction with the center of the through hole as the center. The X-type suction cup group includes: a first suction cup group and a second suction cup group. Each of the first and second suction cup groups includes M2 vacuum suction cups (3-2). The M2 vacuum suction cups (3-2) in the first suction cup group are arranged in an inverted trapezoidal shape. The second suction cup group and the first suction cup group are symmetrically arranged with the center of the through hole on the horizontal straight line. The M1 vacuum suction cups (3-2) of the annular suction cup group are evenly distributed around the through hole.

4. The friction plug repair welding system according to claim 1, characterized in that, Each vacuum suction cup (3-2) is connected to a vacuum generator, and each vacuum suction cup (3-2) is equipped with a vacuum sensor for real-time monitoring of the vacuum level.

5. The friction plug repair welding system according to claim 4, characterized in that, M suction cup bases are fixed on the support frame, and each suction cup base is connected to a vacuum suction cup (3-2) through a universal joint.

6. The friction plug repair welding system according to claim 5, characterized in that, The head assembly (3) also includes an industrial camera (3-4), two small-range laser rangefinders (3-3) and four large-range laser rangefinders (3-5). The industrial camera (3-4), two small-range laser rangefinders (3-3) and four large-range laser rangefinders (3-5) are all fixed on the side of the support frame away from the friction plug welding spindle head (2). Among them, the two small-range laser rangefinders (3-3) are fixed on both sides of the through hole with the horizontal straight line where the center of the through hole is located as the axis of symmetry, and the four large-range laser rangefinders (3-5) are arranged in a rectangular array on the support frame.

7. The friction plug repair welding system according to claim 6, characterized in that, The distance between each small-range laser rangefinder (3-3) and the center of the through hole is 50~150mm.

8. The friction plug repair welding system according to claim 6, characterized in that, At each of the four corners of the support frame, a large-range laser range sensor (3-5) is fixedly mounted.

9. The friction plug repair welding system according to claim 1, characterized in that, The range of the small-range laser rangefinder (3-3) is 0.1 to 10 mm, and the range of the large-range laser rangefinder (3-5) is 40 to 400 mm.

10. The method of using the friction plug repair welding system as described in claim 6, characterized in that, include: First, follow the "Positioning and Fitting Accuracy Adjustment Method," then follow the "Use of the Tool Holder in Friction Plug Repair Welding." The methods for adjusting positioning and fitting accuracy include: Step 1: Use an industrial camera (3-4) to capture the outline of the surface defect of the workpiece to be welded, obtain the image of the outline, extract the pixel coordinates of several feature points of the outline in the pixel coordinate system, calculate the pixel coordinates of the center of the outline based on the pixel coordinates of several feature points, and convert the pixel coordinates of the center of the outline into the corresponding coordinates in the world coordinate system. The Z-axis direction of the world coordinate system is the same as the normal direction of the center of the defect outline. Step 2: Bring the friction plug welding spindle head device close to the workpiece to be welded until the outer surface of the workpiece is within the range of the large-range laser range sensor (3-5). Align the center coordinates of the friction plug welding spindle head (2) with the center of the defect profile in the XY plane of the world coordinate system. Calculate the pitch angle of the friction plug welding spindle head device based on the four large-range laser range sensors (3-5). and yaw angle Adjust the rotation angle of the friction plug welding spindle head assembly to adjust its pitch angle. and yaw angle To the maximum extent possible, the axial direction of the friction plug welding spindle head (2) coincides with the normal direction of the center of the defect profile; Step 3: Further bring the friction plug welding spindle head device close to the workpiece to be welded and make it fit the outer surface of the workpiece. Make the M vacuum chucks (3-2) initially fit with the outer surface of the workpiece. Start the vacuum generator so that the friction plug welding spindle head device is adsorbed on the outer surface of the workpiece. Perform the judgment method, which includes the following steps: S1, calculate the ranging values ​​of the two small-range laser rangefinders (3-3); S2, if the distance values ​​of both small-range laser rangefinders (3-3) are less than the distance threshold, then the vacuum chuck (3-2) fits well with the outer surface of the workpiece to be welded, and the judgment method ends; if the distance value of any small-range laser rangefinder (3-3) is greater than or equal to the distance threshold, then proceed according to S3. S3, turn off the vacuum generator, adjust the angle of the friction plug welding spindle head device until γ is close to 0 at its maximum, adjust the friction plug welding spindle head device and then turn on the vacuum generator so that the friction plug welding spindle head device is re-adsorbed onto the outer surface of the workpiece to be welded; repeat S1~S2. in, , The difference between the ranging values ​​of the two small-range laser rangefinders (3-3) is given by denoted by D, where D is the installation distance between the two small-range laser rangefinders (3-3). Step 4: Based on each vacuum sensor, determine the adsorption state of the individual vacuum suction cup (3-2) connected to it: If the vacuum sensor detects that the absolute pressure of the vacuum degree of its corresponding vacuum suction cup (3-2) is greater than the absolute pressure of the preset vacuum degree, then adjust the adsorption angle of the vacuum suction cup (3-2) until the absolute pressure of the vacuum degree of the vacuum suction cup (3-2) is less than or equal to the absolute pressure of the preset vacuum degree. The specific steps for using a tool holder in friction plug repair welding are as follows: Step 1: Align the two fasteners (1-3-1) so that the arc-shaped fastening parts of the two fasteners (1-3-1) form a ring-shaped structure. Place the split fastening sleeve (1-3) into the blind hole of the tool holder body (1-1). Then tighten the lock nut (1-2) on the tool holder body (1-1). At this time, the shape of the mounting hole (1-2-1) is not opposite to the cross section of the outer contour of the split fastening sleeve (1-3). The split fastening sleeve (1-3) is limited in the blind hole by the lock nut (1-2). Screw the tool into the ring-shaped structure and connect it with the internal thread (1-3-1-1). The friction plug welding spindle head (2) installs the tool through the tool holder (1). The friction plug welding spindle head (2) enlarges the hole of the defect of the workpiece to be welded through the tool to form a plug hole. After forming the plug hole, rotate the tool and take the tool out from the ring-shaped structure. Step 2: Screw the plug rod into the ring-shaped structure and connect it with the internal thread (1-3-1-1). Use the friction plug welding spindle head (2) with the plug rod installed to perform friction plug welding on the plug hole. After the friction plug welding is completed, the end of the plug rod away from the tool holder (1) is now welded to the plug hole. Rotate the lock nut (1-2) until the shape of the mounting hole (1-2-1) is opposite to the cross section of the outer contour of the split fastening sleeve (1-3). The friction plug welding spindle head (2) drives the tool holder (1) to move away from the plug hole along its axis. Under the pushing force of the spring washer (1-4) on the plug rod, the split fastening sleeve (1-3) moves out of the blind hole along with the plug rod through the mounting hole (1-2-1). At this time, the plug rod is removed from the tool holder body (1-1). The two fasteners (1-3-1) on the plug rod are directly separated and removed from the plug rod.

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