Cold machining device for back gouging of weld joints in pipe

Abstract

The cold machining device for back gouging of the weld joint in the pipe is particularly suitable for efficiently removing a boss and a bottom layer weld bead in the pipe after a U-shaped groove is welded. The device comprises a main shaft, two center supporting structures with spherical bearings, a supporting and locking structure, a feeding assembly, a tool rest assembly and a rotating assembly, all the parts work cooperatively, and the main shaft and the tool rest assembly conduct axial feeding while conducting rotary cutting. The center supporting structure has an automatic aligning function and adapts to pipeline deformation or installation errors; the upper and lower symmetrical tool rests are matched with the adjustable tool, and cutting balance and adaptability are ensured. The device replaces a traditional manual polishing or hot machining technology through a cold machining mode, effectively avoids a heat affected zone, improves the welding seam quality consistency and the joint mechanical property, is particularly suitable for back gouging operation of inner holes of small and medium-caliber pipelines with limited space, has the advantage of being high in machining efficiency, and is suitable for popularization and application. And a key matching technical support is provided for a U-shaped groove high-quality welding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe welding processing, in particular to a cold processing device for pipe welding root cleaning. BACKGROUND

[0002] In engineering applications such as power, petrochemical, nuclear energy, shipbuilding, and high-temperature and high-pressure fluid transportation, the butt welding quality of thick-walled high-pressure pipes is a key factor to ensure the structural integrity and operational safety of the system. To improve the strength, metal fusion quality, and fatigue resistance of the welded joint, as shown in the prior art, a U-shaped groove is widely used in the butt welding of thick-walled pipes. This groove form has the advantages of small groove angle, less filler metal, and concentrated heat-affected zone, which can effectively control the welding stress deformation and improve the welding quality. Figure 10

[0003] In the U-shaped groove welding process, manual backing welding is usually used to preliminarily fuse the groove bevel to ensure root penetration and good forming. However, due to the difficulty in accurately controlling the heat input of manual welding, it is easy to cause uneven structure, coarse grains, local overheating, slag inclusion, incomplete fusion, porosity, and other defects in the bottom area of the weld, which not only reduces the mechanical properties of the welded joint, but also may become a crack source during service, seriously affecting the service life and safety of the pipe system.

[0004] To solve the above problems, a "pre-reserved inner boss" process scheme as shown in the prior art is generally used in engineering practice: that is, a boss with an inner diameter slightly smaller than the inner diameter of the base material is pre-processed at the end of the pipe hole, and the root defects of the backing layer weld are limited within the boss. After welding, the entire boss and the backing layer covered by it are removed by mechanical processing or cold grinding, so as to eliminate the coarse grain area and potential defects and obtain a high-quality weld cross section. Figure 11 However, the existing boss root cleaning process still relies on manual polishing or inefficient tools, and has three major limitations: first, the efficiency is extremely low, the labor intensity is large, the processing consistency is poor, and it is difficult to meet the batch engineering demand; second, in space-limited scenarios such as heat exchangers, nuclear island pipes, and boiler water walls, the tool cannot be operated deeply, and the quality is difficult to guarantee; third, there is a lack of special cold processing equipment, and the hot processing method is easy to cause thermal damage to the base material. Therefore, the development of an inner hole weld root cleaning device with compact structure, suitable for narrow space, and capable of realizing efficient cold processing has become a core requirement for realizing the high-quality welding process chain of the U-shaped groove.

[0005] SUMMARY

[0006] In view of the shortcomings of the prior art described above, the purpose of the present application is to provide a cold processing device for pipe welding root cleaning to solve the problems of low efficiency, space limitation, and easy thermal damage to the base material in the prior art. ​​

[0007] To achieve the above object and other related objects, the present application provides the following technical solutions. The cold processing device for pipe internal weld root cleaning comprises a main shaft, two center support structures for penetrating the main shaft, each of which comprises a spherical bearing with automatic alignment function to adapt to the axis deviation caused by installation error or pipe deformation, a support locking structure sleeved on the outer periphery of the main shaft and matched with the center support structure to realize quick assembly and stable connection between the center support structure and the main shaft, a feeding assembly for driving the main shaft to generate axial feeding movement, a tool holder assembly fixedly arranged on the main shaft and located between the two center support structures, and a rotating assembly for driving the main shaft to rotate, thereby realizing the rotary cutting movement of the tool holder assembly; the feeding assembly and the rotating assembly can work cooperatively to drive the main shaft and the tool holder assembly to simultaneously perform rotary and axial feeding movement.

[0008] To achieve the above technical solutions, the main shaft is positioned and supported on both sides of the pipe internal weld by the two center support structures, the automatic alignment function of the spherical bearing compensates for the axis deviation caused by installation error or pipe deformation, the rotating assembly drives the main shaft to rotate at high speed, the tool holder assembly is driven to rotate synchronously to realize the cutting action, the feeding assembly pushes the main shaft to move axially, the tool holder assembly is axially fed along the weld root, and the two work cooperatively to complete the continuous and stable cold cutting and root cleaning operation, and the support locking structure guarantees the stable connection between the center support structure and the main shaft to avoid displacement deviation during the machining process.

[0009] The cold processing cutting method avoids the heat influence of hot processing on the base material, eliminates potential defects such as heat deformation and micro-cracks, and improves the mechanical properties of the welded joint; the self-adaptive alignment of the spherical bearing and the double support point support design of the two center support structures ensure the machining precision and stability in a narrow space, solve the problems of low efficiency and poor consistency of traditional manual polishing, and realize automatic root cleaning through the cooperative work of the feeding assembly and the rotating assembly, which is especially suitable for the root cleaning scene of the internal hole weld of small and medium diameter pipes with an inner diameter less than 400 mm; the device cuts through the special cold processing tool, can effectively remove the coarse grain area and possible defects in the backing weld, and can ensure the roundness and surface finish of the machining area, thereby significantly improving the consistency and reliability of the welded joint.

[0010] In an embodiment of the present application, the center support structure comprises a spherical bearing sleeved on the main shaft, a bearing seat for embedding the spherical bearing, a support frame fixed on the bearing seat through a plurality of fastening screws, a plurality of adjusting screws uniformly arranged along the circumference of the support frame, and a top block arranged at the end of the adjusting screw and used for pressing against the inner wall of the pipe.

[0011] The center support structure realizes stable positioning of the device in the pipe by the circumferentially distributed adjusting screw rods pressing the top block against the inner wall of the pipe. The spherical bearing is embedded in the bearing seat and is sleeved on the main shaft. When the pipe has axis offset or installation error, the automatic alignment function of the spherical bearing enables the main shaft to maintain coaxiality with the center of the weld. Meanwhile, the center fine adjustment screw is added between the support frame and the spherical bearing, and the extension amount of the center fine adjustment screw is manually adjusted to finely adjust the installation position of the spherical bearing, thereby ensuring the coaxiality of the main shaft and the pipe axis. The radial displacement of the top block is accurately controlled by rotating the adjusting screw rod, thereby ensuring the adaptability of the device in different pipe diameters. The fastening connection of the bearing seat and the support frame and the cooperation of the support locking structure and the main shaft further enhance the overall rigidity and ensure the stability of the main shaft during cutting.

[0012] In an embodiment of the present application, the feeding assembly comprises a front support plate, a rear support plate, a ball screw parallel to the main shaft and connected between the front support plate and the rear support plate, a screw nut sleeved on the ball screw, and a feeding drive assembly arranged at one end of the ball screw close to the rear support plate. The feeding drive assembly comprises a feeding motor and a right-angle speed reducer matched with the feeding motor. The screw nut is provided with the rotating assembly, and the feeding motor drives the ball screw to rotate through the right-angle speed reducer, so that the screw nut drives the rotating assembly and the main shaft to move axially along the ball screw.

[0013] The feeding assembly forms a stable frame through the front support plate and the rear support plate, the ball screw is parallel to the main shaft, the feeding motor drives the ball screw to rotate through the right-angle speed reducer, and the screw nut sleeved on the ball screw is axially displaced. Since the rotating assembly is fixed to the screw nut, the movement of the screw nut drives the rotating assembly and the main shaft to move synchronously axially along the ball screw, so that the tool holder assembly is axially fed along the weld while being rotated and cut, the root depth and the feeding speed are accurately controlled, and the root of the weld is uniformly and continuously removed. In the feeding assembly, the right-angle speed reducer matches the rotation speed and torque of the feeding motor and the ball screw, so that the main shaft and the tool holder assembly have sufficient driving force when being axially fed, especially when processing thick-walled pipe welds or hard slag, so that feeding jamming caused by insufficient torque can be avoided. At the same time, the 90° turning function of the right-angle speed reducer adapts to the compact layout of the device, so that the motor output shaft and the ball screw axis are perpendicular and staggered, the limited installation space in the pipe is saved, and the stable connection of the feeding transmission chain is ensured.

[0014] In an embodiment of the present application, the rotating assembly comprises a motor support plate fixed on the screw nut, a rotating motor arranged on the motor support plate, a planetary reducer arranged at the output end of the rotating motor, and a connecting sleeve sleeved on the main shaft; the output end of the planetary reducer is fixed with the connecting sleeve through a connecting screw; the main shaft and the main shaft connecting sleeve are axially and radially locked by a knock pin screw and a self-locking nut; the rotating motor drives the main shaft to rotate through the planetary reducer, and realizes the cutting rotary motion of the tool holder assembly.

[0015] The rotating assembly is fixed on the screw nut through the motor support plate, so that the whole rotating assembly can move along the ball screw shaft. The rotating motor is installed on the motor support plate, and the output end of the rotating motor is connected with the planetary reducer. After the rotation speed is further reduced and the torque is increased through the planetary reducer, the main shaft is connected with the connecting sleeve. The output end of the planetary reducer is fixed with the connecting sleeve through a connecting screw, so as to ensure the stability of power transmission. The main shaft and the connecting sleeve are axially and radially locked by a knock pin screw and a self-locking nut, so as to prevent relative sliding and ensure efficient power transmission. When the rotating motor is started, the main shaft and the tool holder assembly thereon realize accurate and stable cutting rotary motion through the speed reduction and torque increasing effect of the planetary reducer.

[0016] In an embodiment of the present application, the tool holder assembly comprises two groups of tool holders arranged symmetrically above and below, and locking bolts for locking the two groups of tool holders on the outer periphery of the main shaft; the tool holder is vertically provided with a tool groove, and a tool bar is arranged in the tool groove through a plurality of locking screws, and a blade is arranged at the top end of the tool bar.

[0017] The tool holder assembly is clamped and fixed on the outer periphery of the main shaft through the two groups of tool holders arranged symmetrically above and below, so as to ensure synchronous rotation with the main shaft. The tool bar is fastened in the vertical tool groove of the tool holder through the locking screw, and the top blade rotates with the main shaft to realize cutting action. According to the root cleaning depth and profile requirements, the installation position of the tool bar in the tool groove or the replacement of different specifications of blades can be adjusted, so that the blade accurately fits the root excess height of the weld, and under the cooperation of the rotation of the main shaft and the axial feed, the cold cutting removal of the excess part of the weld root is completed. The upper and lower symmetric double tool holder structure enhances the dynamic balance performance in the cutting process, effectively reduces the equipment vibration, and the tool bar is installed in the tool groove through the locking screw, so that the structure is simple, easy to disassemble and assemble, and different specifications of tools can be replaced to adapt to various welding forms and pipe diameter requirements.

[0018] In an embodiment of the present application, a key groove is arranged on the outer wall of the main shaft in the axial direction, and a flat key is arranged in the inner wall of at least one tool holder and matched with the key groove.

[0019] The key groove is arranged on the outer wall of the main shaft along the axial direction, and the flat key is arranged on the inner wall of the tool holder, the flat key is embedded into the key groove when the tool holder is installed on the main shaft, and the circumferential positioning structure is formed.

[0020] In an embodiment of the present application, the support locking structure comprises: a plurality of grooves arranged circumferentially on the bearing seat; a locking sleeve arranged on the outer periphery of the main shaft; a knob plunger inserted into the groove through the locking sleeve; and a clamping screw for fixing the locking sleeve on the bearing seat.

[0021] The support locking structure is achieved by arranging a plurality of grooves circumferentially on the bearing seat, arranging a locking sleeve on the outer periphery of the main shaft, and inserting a knob plunger into the groove to achieve rapid positioning and connection between the bearing seat and the locking sleeve. When the knob plunger is inserted into the corresponding groove, the locking sleeve can be firmly fixed on the bearing seat by the clamping screw, thereby stably locking the entire center support structure on the main shaft. This structure can be adjusted at different positions and quickly assembled and disassembled, facilitating the adjustment of the position of the center support structure according to actual installation requirements.

[0022] In an embodiment of the present application, a guide sleeve is embedded on the motor support plate, and a guide column fixed at one end on the front support plate and at the other end on the rear support plate and parallel to the ball screw is arranged in the guide sleeve.

[0023] The motor support plate is embedded with a guide sleeve, and a guide column parallel to the ball screw is arranged in the guide sleeve, one end of the guide column is fixed on the front support plate, and the other end is fixed on the rear support plate, forming a stable guide structure. When the feed assembly drives the motor support plate and the rotating assembly thereon to move axially along the ball screw, the cooperation of the guide column and the guide sleeve provides accurate linear guidance for the movement process, effectively preventing the rotating assembly from deflecting or shaking during the movement process, and ensuring the stability and guidance accuracy of the spindle feed movement.

[0024] In an embodiment of the present application, the ball screw is provided with a feed hand wheel at one end close to the right-angle speed reducer.

[0025] The feed hand wheel is arranged at one end of the ball screw close to the right-angle speed reducer, allowing the operator to manually rotate the ball screw to adjust the position of the screw nut, thereby driving the rotating assembly and the spindle connected thereto to move axially. This design provides a mechanical backup option for the device, allowing accurate control of the feed amount of the spindle by manual means when there is no power drive or fine adjustment is required.

[0026] In an embodiment of the present application, the feeding motor and the rotating motor are both electrically connected with the electric control box, an electric control box is electrically connected on the electric control box, operation buttons for adjusting the rotating speed of the rotating assembly and the feeding amount of the feeding assembly are arranged on the electric control box, and a control circuit for receiving the control signal of the electric control box and driving the rotating assembly and the feeding assembly to operate is arranged in the electric control box.

[0027] The above technical solution is realized, the operator sets the rotating speed of the rotating assembly and the feeding amount of the feeding assembly and other parameters through the operation buttons on the electric control box, and the settings are transmitted to the control circuit in the electric control box through the electric control box. After the control circuit analyzes the received signal, it accurately drives the rotating motor to adjust the cutting speed of the tool holder assembly, and controls the feeding motor to realize the axial movement of the spindle, ensuring that the entire cold processing process is efficiently and accurately performed according to the preset parameters.

[0028] As described above, the cold processing device for pipe internal weld root cleaning has the following beneficial effects: mechanical cutting is used instead of hot processing, which completely avoids the generation of heat affected zone (HAZ), eliminates local hardening, micro-cracks or changes in the base material, and guarantees the mechanical properties and long-term service reliability of the welded joint; the overall structure of the device is compact, suitable for the internal working environment of small and medium caliber pipes, and can work stably in limited space, solving the problem of "not going in and difficult to operate" of traditional tools in complex scenes such as heat exchangers and nuclear island pipes; the automatic centering function of the spherical bearing in the center support structure, combined with the double fulcrum positioning design, can adapt to the axis offset caused by installation error or pipe deformation, ensuring the coaxiality of the spindle and the pipe axis, thereby realizing high-precision and high-consistency root cleaning operation; the rotation and feeding motion of the spindle are controlled by two motors respectively, which can realize the reciprocating motion of processing and can adjust the cutting parameters at any time according to the processing difficulty of the weld. The feeding assembly adopts a structure of ball screw plus guide column guide, which is compact in overall structure and minimizes the weight of the equipment while ensuring strength, suitable for manual carrying; a high-rigidity surface-hardened chromium-plated spindle is used, which can be stably installed in the inner hole of the spherical bearing on both sides of the weld, a key groove is processed on the spindle, and the tool holder can be installed at any position on the spindle and positioned and torque is transmitted through a flat key. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The structure of the present application is shown.

[0030] Figure 2 The installation of the present application in the pipe is shown.

[0031] Figure 3 The installation of the spindle and the center support structure in the pipe is shown.

[0032] Figure 4Structure diagram showing the center support structure.

[0033] Figure 5 Connection diagram showing the support locking structure.

[0034] Figure 6 Exploded view diagram showing the feed assembly and the rotation assembly.

[0035] Figure 7 Connection diagram showing the feed assembly and the rotation assembly.

[0036] Figure 8 Structure diagram showing the mounting structure of the tool holder assembly and the main shaft.

[0037] Figure 9 Structure diagram showing the tool holder assembly.

[0038] Figure 10 Structure diagram showing the typical weld structure without weld process improvement.

[0039] Figure 11 Structure diagram showing the weld structure with an inner boss in the weld.

[0040] Element number explanation

[0041] 1. main shaft; 2. spherical bearing; 3. bearing seat; 4. fastening screw; 5. support frame; 6. adjusting screw; 7. top block; 8. front support plate; 9. rear support plate; 10. ball screw; 11. screw nut; 12. feed motor; 13. right-angle speed reducer; 14. motor support plate; 15. rotation motor; 16. planetary speed reducer; 17. connecting sleeve; 18. connecting screw; 19. plug screw; 20. self-locking nut; 21. tool holder; 22. locking bolt; 23. tool groove; 24. locking screw; 25. tool bar; 26. tool blade; 27. key groove; 28. flat key; 29. groove; 30. locking sleeve; 31. knob plunger; 32. set screw; 33. guide sleeve; 34. guide post; 35. feed hand wheel; 36. electric control box; 37. electric control box; 38. center fine adjustment screw. DETAILED DESCRIPTION

[0042] The following specific embodiments illustrate the embodiments of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. It should be noted that the following examples and features in the examples can be combined with each other without conflict.

[0043] Please refer to Figures 1-9The application provides a cold processing device for pipe internal weld root cleaning, which comprises a main shaft 1, two center support structures for penetrating the main shaft 1, each of the center support structures comprising a spherical bearing 2 with automatic alignment function to adapt to axis deviation caused by installation error or pipe deformation, a support locking structure sleeved on the outer periphery of the main shaft 1 and matched with the center support structure to realize quick assembly and stable connection between the center support structure and the main shaft 1, a feeding assembly for driving the main shaft 1 to generate axial feeding movement, a tool holder assembly fixedly arranged on the main shaft 1 and located between the two center support structures, and a rotating assembly for driving the main shaft 1 to rotate, so as to realize rotary cutting movement of the tool holder assembly; the feeding assembly and the rotating assembly can work cooperatively to drive the main shaft 1 and the tool holder assembly to simultaneously generate rotary and axial feeding movement.

[0044] The device positions and supports the main shaft 1 on both sides of the pipe internal weld through the two center support structures, the automatic alignment function of the spherical bearing 2 compensates for the axis deviation caused by installation error or pipe deformation, the rotating assembly drives the main shaft 1 to rotate at high speed, drives the tool holder assembly to synchronously rotate to realize cutting action, and the feeding assembly pushes the main shaft 1 to move axially, so that the tool holder assembly feeds axially along the weld root, and the two work cooperatively to complete continuous and stable cold cutting and root cleaning operation, and the support locking structure guarantees stable connection between the center support structure and the main shaft 1, and avoids displacement deviation in the machining process.

[0045] The cold processing cutting mode avoids the heat influence of hot processing on the base material, eliminates potential defects such as heat deformation and micro cracks, and improves the mechanical properties of the welded joint; the self-adaptive alignment of the spherical bearing 2 and the double support point support design of the two center support structures ensure the machining precision and stability in a narrow space, and solve the problems of low efficiency and poor consistency in traditional manual polishing; the feeding assembly and the rotating assembly work cooperatively to realize automatic root cleaning, and are especially suitable for small and medium diameter pipe internal hole weld root cleaning scenes with an inner diameter less than 400 mm; the device cuts through special cold processing cutters, can effectively remove the coarse grain area and possible defects in the backing weld, can guarantee the roundness and surface smoothness of the machining area, and significantly improves the consistency and reliability of the welded joint.

[0046] The center support structure comprises a spherical bearing 2 sleeved on the main shaft 1, a bearing seat 3 for embedding the spherical bearing 2, a support frame 5 fixed on the bearing seat 3 through a plurality of fastening screws 4, a plurality of adjusting screws 6 evenly arranged in the circumferential direction of the support frame 5, and a top block 7 arranged at the end of the adjusting screw 6 and used for pressing against the inner wall of the pipe.

[0047] The center support structure presses the top block 7 against the inner wall of the pipeline through the circumferentially distributed adjusting screw 6, so as to realize the stable positioning of the device in the pipeline. The spherical bearing 2 is embedded in the bearing seat 3 and is sleeved on the main shaft 1. When the pipeline has axis offset or installation error, the automatic alignment function of the spherical bearing 2 enables the main shaft 1 to still maintain coaxiality with the center of the weld. Meanwhile, the center fine adjustment screw 38 is added between the support frame 5 and the spherical bearing 2, the extension amount of the center fine adjustment screw 38 is adjusted manually, the installation position of the spherical bearing 2 is finely adjusted, and the coaxiality requirement of the main shaft 1 and the pipeline axis is ensured. The radial displacement of the top block 7 is accurately controlled through the rotation of the adjusting screw 6, so as to ensure the adaptability of the device in the pipeline with different diameters. The fastening connection between the bearing seat 3 and the support frame 5 and the cooperation between the support locking structure and the main shaft 1 further enhance the overall rigidity and ensure the stability of the main shaft 1 during cutting.

[0048] The feeding assembly comprises a front support plate 8, a rear support plate 9, a ball screw 10 connected between the front support plate 8 and the rear support plate 9 and arranged in parallel with the main shaft 1, a screw nut 11 sleeved on the ball screw 10, a feeding drive assembly arranged at one end of the ball screw 10 close to the rear support plate 9, the feeding drive assembly comprising a feeding motor 12 and a right-angle speed reducer 13 matched with the feeding motor 12, and the rotating assembly is arranged on the screw nut 11. The feeding motor 12 drives the ball screw 10 to rotate through the right-angle speed reducer 13, so that the screw nut 11 drives the rotating assembly and the main shaft 1 to move axially along the ball screw 10.

[0049] The feeding assembly forms a stable frame through the front support plate 8 and the rear support plate 9, the ball screw 10 is arranged in parallel with the main shaft 1, and the feeding motor 12 drives the ball screw 10 to rotate through the right-angle speed reducer 13, so that the screw nut 11 sleeved on the ball screw 10 generates axial displacement. Since the rotating assembly is fixed to the screw nut 11, the movement of the screw nut 11 drives the rotating assembly and the main shaft 1 to move axially synchronously along the ball screw 10, so as to realize the axial feeding of the tool holder assembly while rotating cutting, accurately control the root depth and the feeding speed, and ensure that the root of the weld is uniformly and continuously removed. In the feeding assembly, the core function of the right-angle speed reducer 13 is to match the rotating speed and torque of the feeding motor 12 and the ball screw 10, so as to ensure that the main shaft 1 and the tool holder assembly have sufficient driving force during axial feeding, especially when processing thick-walled pipeline welds or hard slag, so as to avoid the feeding jam caused by insufficient torque. At the same time, the 90° turning function of the right-angle speed reducer 13 adapts the compact layout of the device, so that the motor output shaft and the ball screw 10 axis are perpendicular and staggered, the limited installation space in the pipeline is saved, and the stable connection of the feeding transmission chain is ensured.

[0050] The rotating assembly comprises a motor support plate 14 fixed on the screw nut 11, a rotating motor 15 arranged on the motor support plate 14, a planetary reducer 16 arranged at the output end of the rotating motor 15, and a connecting sleeve 17 sleeved on the main shaft 1; the output end of the planetary reducer 16 is fixed with the connecting sleeve 17 through a connecting screw 18; the main shaft 1 and the connecting sleeve 17 are axially and radially locked through a knock pin screw 19 and a self-locking nut 20; the rotating motor 15 drives the main shaft 1 to rotate through the planetary reducer 16, and realizes the cutting rotary motion of the tool holder assembly.

[0051] The rotating assembly is fixed on the screw nut 11 through the motor support plate 14, so that the whole rotating assembly can move axially along the ball screw 10 with the screw nut 11. The rotating motor 15 is installed on the motor support plate 14, and the output end thereof is connected with the planetary reducer 16. After the rotating motor 15 is further reduced in speed and increased in torque through the planetary reducer 16, the output end is connected with the main shaft 1 through the connecting sleeve 17. The output end of the planetary reducer 16 is fixed with the connecting sleeve 17 through the connecting screw 18, so as to ensure the stability of power transmission. The main shaft 1 and the connecting sleeve 17 are axially and radially locked through the knock pin screw 19 and the self-locking nut 20, so as to prevent relative sliding and ensure efficient power transmission. When the rotating motor 15 is started, the main shaft 1 and the tool holder assembly thereon realize precise and stable cutting rotary motion through the speed reduction and torque increase of the planetary reducer 16.

[0052] The tool holder assembly comprises two groups of tool holders 21 arranged symmetrically upward and downward, and locking bolts 22 for locking the two groups of tool holders 21 on the outer periphery of the main shaft 1. The tool holder 21 is vertically provided with a tool groove 23, and a tool bar 25 is arranged in the tool groove 23 through a plurality of locking screws 24. The tool bar 25 is provided with a blade 26 at the top end thereof. The tool holder assembly is clamped and fixed to the outer periphery of the main shaft 1 through the two groups of tool holders 21 arranged symmetrically upward and downward, so as to ensure synchronous rotation with the main shaft 1. The tool bar 25 is fastened in the vertical tool groove 23 of the tool holder 21 through the locking screws 24, and the blade 26 at the top end thereof rotates with the main shaft 1 to realize cutting action. According to the root cleaning depth and profile requirements, the installation position of the tool bar 25 in the tool groove 23 or the different specifications of the blade 26 can be adjusted, so that the blade 26 accurately fits the root excess height of the weld, and under the synergistic action of the rotation and axial feeding of the main shaft 1, the cold cutting removal of the excess part of the weld root is completed. The upward and downward symmetric double tool holders 21 structure enhances the dynamic balance performance in the cutting process, effectively reduces the equipment vibration, and the tool bar 25 is installed in the tool groove 23 through the locking screws 24, so as to have simple structure, convenient disassembly and assembly, and facilitate replacement of different specifications of tools to adapt to various welding forms and pipe diameter requirements.

[0053] The outer wall of the main shaft 1 is provided with a key groove 27 in the axial direction, and the inner wall of at least one tool holder 21 is provided with a flat key 28 matched with the key groove 27. In the device, the outer wall of the main shaft 1 is provided with a key groove 27 in the axial direction, and the inner wall of the tool holder 21 is provided with a flat key 28 matched with the key groove 27. When the tool holder 21 is installed on the main shaft 1, the flat key 28 is embedded in the key groove 27 to form a circumferential positioning structure. This structure makes the tool holder 21 and the main shaft 1 rotate synchronously during rotation, preventing the tool holder 21 from slipping or deflecting on the main shaft 1. Combined with the axial fixation of the locking bolt 22, reliable connection of the tool holder 21 on the main shaft 1 can be achieved, ensuring the stability and accuracy of power transmission during cutting.

[0054] The support locking structure includes a plurality of grooves 29 opened in the circumferential direction of the bearing seat 3, a locking sleeve 30 sleeved on the outer circumference of the main shaft 1, a knob plunger 31 inserted into the groove 29 through the locking sleeve 30, and a clamping screw 32 for fixing the locking sleeve 30 on the bearing seat 3.

[0055] The support locking structure is achieved by opening a plurality of grooves 29 in the circumferential direction of the bearing seat 3, sleeving a locking sleeve 30 on the outer circumference of the main shaft 1, and inserting a knob plunger 31 into the groove 29 to achieve quick positioning and connection between the bearing seat 3 and the locking sleeve 30. After the knob plunger 31 is inserted into the corresponding groove 29, the locking sleeve 30 can be firmly fixed on the bearing seat 3 by the clamping screw 32, thereby stably locking the entire center support structure on the main shaft 1. This structure can be adjusted at different positions and quickly assembled and disassembled, making it convenient to adjust the position of the center support structure according to actual installation needs.

[0056] The motor support plate 14 is embedded with a guide sleeve 33, and a guide column 34 is inserted into the guide sleeve 33, one end of which is fixed on the front support plate 8 and the other end is fixed on the rear support plate 9, and is parallel to the ball screw 10.

[0057] The motor support plate 14 is embedded with a guide sleeve 33, and a guide column 34 is inserted into the guide sleeve 33, one end of which is fixed on the front support plate 8 and the other end is fixed on the rear support plate 9, and is parallel to the ball screw 10. This forms a stable guide structure. When the feed assembly drives the nut 11 to move the motor support plate 14 and the rotating assembly on it along the ball screw 10 in the axial direction, the cooperation of the guide column 34 and the guide sleeve 33 provides accurate linear guidance for the movement process, effectively preventing the rotating assembly from deflecting or shaking during movement, and ensuring the stability and guidance accuracy of the main shaft 1 feed movement.

[0058] The ball screw 10 is provided with a feed hand wheel 35 at one end close to the right-angle speed reducer 13. The feed hand wheel 35 is arranged at one end of the ball screw 10 close to the right-angle speed reducer 13, allowing the operator to manually rotate the ball screw 10 to adjust the position of the screw nut 11, thereby driving the rotary assembly and the spindle 1 connected thereto to move axially. This design provides a mechanical backup option for the device, allowing accurate control of the feed amount of the spindle 1 through manual operation when there is no power drive or when fine adjustment is required.

[0059] The feed motor 12 and the rotary motor 15 are electrically connected with an electric control box 36, and the electric control box 36 is electrically connected with an electric control box 37, which is provided with operation buttons for adjusting the rotating speed of the rotary assembly and the feed amount of the feed assembly. The electric control box 36 is provided with a control circuit for receiving the control signals of the electric control box 37 and driving the rotary assembly and the feed assembly to operate.

[0060] The operator sets the rotating speed of the rotary assembly and the feed amount of the feed assembly through the operation buttons on the electric control box 37. These settings are transmitted to the control circuit in the electric control box 36 through the electric control box 37. After analyzing the received signals, the control circuit accurately drives the rotary motor 15 to adjust the cutting speed of the tool holder assembly, and controls the feed motor 12 to realize the axial movement of the spindle 1, ensuring that the entire cold working process is efficiently and accurately performed according to the preset parameters.

[0061] The present application adopts mechanical cutting instead of hot working, completely avoids the generation of heat affected zone (HAZ), eliminates local hardening, micro-cracks or changes in the microstructure of the base material, and ensures the mechanical properties and long-term service reliability of the welded joint. The overall structure of the device is compact, suitable for the internal working environment of small and medium caliber pipelines, and can work stably in limited space, solving the problem of "difficulty in entering and operating" of traditional tools in complex scenes such as heat exchangers and nuclear island pipelines. The automatic alignment function of the spherical bearing 2 in the center support structure, combined with the double fulcrum positioning design, can adapt to the axis deviation caused by installation errors or pipeline deformation, ensuring the coaxiality of the spindle 1 and the pipeline axis, and realizing high-precision and high-consistency root cleaning operation. The rotation and feed motion of the spindle 1 are controlled by two motors respectively, which can realize reciprocating motion of machining and can adjust the cutting parameters at any time according to the processing difficulty of the weld. The feed assembly adopts the structure of ball screw 10 plus guide column 34, which is compact in overall structure and minimizes the weight of the equipment while ensuring strength, suitable for manual handling. The high-rigidity surface-hardened and chromium-plated spindle 1 can be stably installed in the inner hole of the spherical bearing on both sides of the weld. The spindle 1 is provided with a key groove 27, and the tool holder 21 can be installed at any position on the spindle 1 and positioned and torque-transmitted through a flat key 28.

[0062] The above embodiments merely illustrate the principles of the application and its efficacy, and are not intended to limit the application. All equivalent modifications or changes made by those with ordinary knowledge in the art without departing from the spirit and technical ideas disclosed in the application shall be covered by the claims of the application.

Claims

1. A cold working apparatus for cleaning the root of weld seams inside pipes, characterized in that, include: Main spindle (1); Two central support structures are used to pass through the main shaft (1), each of the central support structures includes a spherical bearing (2) which has an auto-aligning function to accommodate axial offset caused by installation errors or pipe deformation; A support locking structure, which is sleeved on the outer periphery of the main shaft (1) and cooperates with the central support structure, is used to realize the quick assembly and stable connection between the central support structure and the main shaft (1). The feed assembly is used to drive the spindle (1) to generate axial feed motion; The tool holder assembly is fixedly mounted on the spindle (1) and located between the two central support structures; The rotating component drives the spindle (1) to rotate, thereby realizing the rotary cutting motion of the tool holder assembly; The feed assembly and the rotary assembly can work together to drive the spindle (1) and the tool holder assembly to perform rotational and axial feed movements simultaneously.

2. The cold working device for cleaning the root of weld seams inside pipes according to claim 1, characterized in that, The central support structure includes: A spherical bearing (2) is sleeved on the main shaft (1); Bearing housing (3) for mounting the spherical bearing (2); The support frame (5) is fixed to the bearing seat (3) by multiple fastening screws (4); A number of adjusting screws (6) are evenly distributed around the circumference of the support frame (5); The top block (7) is located at the end of the adjusting screw (6) and is used to press against the inner wall of the pipe.

3. The cold working device for cleaning the root of weld seams inside pipes according to claim 1, characterized in that, The feed assembly includes: Front support plate (8), rear support plate (9); A ball screw (10) is connected between the front support plate (8) and the rear support plate (9) and is arranged parallel to the main shaft (1); Screw nut (11) sleeved on the ball screw (10); A feed drive assembly is provided at one end of the ball screw (10) near the rear support plate (9); The feed drive assembly includes a feed motor (12) and a right-angle reducer (13) that is matched with the feed motor (12); The lead screw nut (11) is provided with the rotating component. The feed motor (12) drives the ball screw (10) to rotate through the right angle reducer (13), so that the lead screw nut (11) drives the rotating component and the main shaft (1) to move along the axial direction of the ball screw (10).

4. A cold working device for cleaning the root of weld seams inside pipes according to claim 3, characterized in that, The rotating component includes: A motor support plate (14) fixed on the lead screw nut (11), a rotary motor (15) set on the motor support plate (14), a planetary reducer (16) set at the output end of the rotary motor (15), and a connecting sleeve (17) sleeved on the main shaft (1); The output end of the planetary reducer (16) is fixed to the connecting sleeve (17) by connecting screws (18); The spindle (1) and the spindle connecting sleeve (17) are axially and radially locked together by a plug screw (19) and a self-locking nut (20); The rotary motor (15) drives the spindle (1) to rotate through the planetary reducer (16) and realizes the cutting rotation motion of the tool holder assembly.

5. A cold working device for cleaning the root of weld seams inside pipes according to claim 1, characterized in that, The tool holder assembly includes two sets of tool holders (21) arranged symmetrically at the top and bottom, and locking bolts (22) for locking the two sets of tool holders (21) on the outer periphery of the spindle (1); The tool holder (21) has a vertically oriented tool groove (23), and a tool bar (25) is installed in the tool groove (23) by a number of locking screws (24). A blade (26) is installed at the top of the tool bar (25).

6. A cold working apparatus for cleaning the root of weld seams inside pipes according to claim 5, characterized in that, The outer wall of the spindle (1) is provided with a keyway (27) along the axial direction, and at least one of the tool holders (21) is provided with a flat key (28) that mates with the keyway (27) in the inner wall.

7. A cold working device for cleaning the root of weld seams inside pipes according to claim 2, characterized in that, The support locking structure includes: Several grooves (29) are formed in the circumference of the bearing housing (3); A locking sleeve (30) is fitted around the outer periphery of the main shaft (1); A knob plunger (31) passes through the locking sleeve (30) and is inserted into the groove (29); Set screws (32) are used to secure the locking sleeve (30) to the bearing housing (3).

8. A cold working device for cleaning the root of weld seams inside pipes according to claim 4, characterized in that, The motor support plate (14) is fitted with a guide sleeve (33), and a guide post (34) with one end fixed on the front support plate (8) and the other end fixed on the rear support plate (9) and parallel to the ball screw (10) is inserted through the guide sleeve (33).

9. A cold working device for cleaning the root of weld seams inside pipes according to claim 3, characterized in that, The ball screw (10) is provided with a feed handwheel (35) at one end near the right angle reducer (13).

10. A cold working device for cleaning the root of weld seams inside pipes according to claim 4, characterized in that, The feed motor (12) and the rotary motor (15) are both electrically connected to the electrical control box (36). The electrical control box (36) is electrically connected to an electrical control box (37). The electrical control box (37) is provided with operation buttons for adjusting the rotation speed of the rotary component and the feed amount of the feed component. The electrical control box (36) is provided with a control circuit for receiving control signals from the electrical control box (37) and driving the rotary component and the feed component to run.

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