Welding device and welding method for branch pipe of plastic inspection shaft

Abstract

The invention discloses a plastic inspection shaft branch pipe welding device and method.The plastic inspection shaft branch pipe welding device comprises a workbench, a shaft fixing unit, a branch pipe clamping unit, a welding unit and a controller, the shaft fixing unit comprises a height adjusting mechanism and a supporting mechanism, and the height adjusting mechanism comprises a guide rod, a vertical lead screw and a lead screw motor; the supporting mechanism comprises a supporting platform and a telescopic supporting assembly. The clamping unit comprises a pipeline clamp; the welding unit comprises a moving mechanism, a rotating mechanism and a welding mechanism positioning mechanism, the welding mechanism comprises a hot melting welding gun, and the positioning mechanism comprises a positioning roller. And the hot melting welding gun capable of adjusting the position and angle of the welding seam and the positioning roller are adopted to weld the branch pipe, so that the branch pipe is accurate in welding control, the welding seam is flat and smooth, the welding efficiency is high, the labor intensity is low, and the high-quality industrial production requirement can be met.

Description

Technical Field

[0001] The invention relates to the technical field of plastic welding, and in particular to a plastic inspection shaft branch pipe welding device and a welding method with accurate positioning and smooth welds. Background Art

[0002] Inspection wells are junctions that connect underground drainage pipes within buildings to the city's underground pipe network. They are usually located at the intersection of drainage pipes, bends, diameter changes, slope changes, and waterfalls. They are also workstations for pipe dredging to facilitate regular inspections, cleaning, and dredging, as well as operations down the well. At present, there are plastic one-piece injection-molded inspection wells and brick-built inspection wells on the market. Among them, plastic inspection wells use special wellbores, which can be cut to the corresponding length according to the on-site burial depth. They are flexible and convenient. The inlet and outlet pipes are connected to the wellbore by hot-melt welding or sealing ring flexible socket-type connection, which can adapt to certain angle changes, are easy to construct, have good sealing performance and prevent leakage, and effectively prevent secondary pollution of groundwater. It is an environmentally friendly and energy-saving building material.

[0003] The welding of plastic inspection well branches is generally done manually with a small hot-melt welding gun. Due to the curved wall of the welding point and the inconsistent size and depth of the weld, manual welding will result in uneven and rough welds and uneven melting of the material. In addition, there is a temperature difference between the welding point at the wellbore opening and the hot-melt adhesive, which will cause the two to not fuse properly or produce bubbles or particles, reducing the welding quality, insufficient branch pipe connection strength, low shear resistance, and poor sealing at the weld. At the same time, manual welding takes a long time, has low efficiency, high labor intensity, and is not suitable for industrial production. Summary of the invention

[0004] The present invention mainly solves the above-mentioned technical problems and provides a plastic inspection shaft branch pipe welding device and welding method with accurate positioning and smooth welds.

[0005] In order to solve the above-mentioned technical problems, the present invention mainly adopts the following technical solutions: The plastic inspection shaft branch pipe welding device of the present invention comprises: A workbench, used to place the shaft fixing unit, branch pipe clamping unit, branch pipe welding unit and inspect the shaft; A shaft fixing unit, used for positioning, clamping and fixing the inspection shaft, comprises a height adjustment mechanism and a support mechanism, wherein the height adjustment mechanism comprises a guide rod, a vertical screw rod and a vertical screw rod motor for driving the vertical screw rod placed on a workbench, and the support mechanism comprises a support platform and a telescopic support assembly placed on the support platform, wherein the support platform is sleeved on the vertical screw rod and rises and falls with the vertical screw rod; A branch pipe clamping unit, used for clamping and fixing the branch pipe, comprises a pipe clamp fixed on the workbench; A branch pipe welding unit for welding a branch pipe, comprising a moving mechanism, a rotating mechanism and a welding mechanism. The moving mechanism includes a longitudinal guide rail fixed on a workbench and a frame placed on the longitudinal guide rail and moving along the longitudinal guide rail. The rotating mechanism includes a circular track placed on the frame and a sliding table placed on the circular track and moving along the circular track. The welding mechanism is fixedly arranged on the sliding table, and the welding mechanism includes a hot melt welding gun. A controller controls the wellbore fixing unit, the branch pipe clamping unit and the branch pipe welding unit, and includes a human-machine interaction interface. The welding device adopts a telescopic support assembly with adjustable height, can position and fix the wellbore as needed, and uses a hot melt welding gun with adjustable weld position and angle to weld the branch pipe, making the branch pipe weld smooth, accurately controlled, with high welding efficiency and low labor intensity, and can meet the industrial production requirements of large quantities and high quality.

[0006] Preferably, a positioning ring groove matching the diameter of the inspection wellbore is provided on the workbench. The groove width of the positioning ring groove matches the wall thickness of the inspection wellbore. The lower end of the inspection wellbore is embedded in the positioning ring groove. The axis of the vertical lead screw coincides with the central axis of the positioning ring groove. The above-mentioned guide rod is fixed on the surface of the base and perpendicular to the surface of the base. The above-mentioned support platform is sleeved on the vertical lead screw and the guide rod and rises and falls as the vertical lead screw rotates. The above-mentioned vertical lead screw motor is electrically connected to the above-mentioned controller. The positioning of the inspection wellbore on the workbench adopts the positioning ring groove, combined with a support platform with adjustable height, for double positioning and support, making the positioning and fixing of the inspection wellbore fast and accurate.

[0007] Preferably, the telescopic support assembly includes a plurality of telescopic cylinders and arc-shaped support plates fixed at the ends of the piston rods of the telescopic cylinders. The telescopic cylinders are fixed on the support platform, and the directions of their piston rods radiate outward at equal angles with the center point of the support platform as the center. The above-mentioned telescopic cylinders are constant pressure cylinders. The telescopic cylinders are electrically connected to the controller and connected to an external air source through air pipes. The telescopic length of the piston rods of the telescopic cylinders matches the inner diameter of the inspection wellbore. The support plates fit the inner wall arc surface of the inspection wellbore and adhere to the inner wall surface of the inspection wellbore. The telescopic inner support structure is adopted, combined with the positioning ring groove, to accurately fix the inspection wellbore on the base, with convenient control. The constant pressure cylinders drive the support plates to provide a constant support force to the inner wall of the wellbore, and the clamping is safe, reliable and uniform.

[0008] Preferably, there are four telescopic cylinders, which are evenly distributed in a cross-shaped circle on the support platform. The cross-shaped inner support structure is adopted to realize annular multi-point tensioning support, and the support force is dispersed and uniform.

[0009] Preferably, the support plate is a vacuum suction cup. A vacuum tube is provided on the back of the suction cup and is connected to an external vacuum device through a suction cup control valve. The control valve of the suction cup is electrically connected to the controller. Using a vacuum suction cup as the clamping method between the support end and the inner wall of the wellbore makes the support safer and more reliable and not prone to falling off.

[0010] Preferably, the longitudinal movement mechanism includes a longitudinal guide rail fixed on the workbench, a longitudinal lead screw, a longitudinal lead screw motor, and a frame placed on the longitudinal guide rail. The longitudinal lead screw motor drives the longitudinal lead screw to rotate and drives the frame to move along the longitudinal guide rail. The rotation mechanism includes a servo motor fixed in the center of the frame, a circular track fixed on the frame with the output shaft of the servo motor as the center of the circle, and a slide table sleeved on the circular track and moving along the circular track. A cross bar is fixed on the output shaft of the servo motor, and the inner side of the slide table is fixedly connected to the end of the cross bar. The output shaft of the servo motor drives the cross bar to rotate and drives the slide table to move along the circular track. The welding mechanism includes a transverse guide rail, a transverse lead screw, a transverse lead screw motor, and a welding platform placed on the transverse lead screw and moving along the transverse lead screw. The transverse lead screw and the transverse lead screw motor are fixed on the slide table. The transverse lead screw motor drives the transverse lead screw to rotate, and the direction of the transverse lead screw faces the output shaft of the servo motor. A propulsion cylinder is fixed on the welding platform, a bracket is fixed at the end of the piston rod of the propulsion cylinder, and a hot melt welding gun is fixed on the bracket. The above-mentioned hot melt welding gun is inclined inward, and its head corresponds to the welding area at the connection between the branch pipe and the wellbore opening. The above-mentioned propulsion cylinder is electrically connected to the controller and is connected to an external air source through an air pipe. The hot melt welding gun adopts a multi-directionally controllable movement method to form a multi-loop 360° annular stacked hot melt adhesive weld seam at the curved connection of the branch pipes, ensuring the flatness and smoothness of the weld seam at the connection and good welding tightness.

[0011] Preferably, the welding unit further includes a positioning mechanism. The positioning mechanism includes a positioning rod and a positioning roller. The rear end of the positioning rod is fixed on the bracket and its direction is consistent with the axial direction of the longitudinal guide rail on the workbench. The positioning roller is fixed at the front end of the positioning rod. The positioning roller abuts against the outer wall surface of the wellbore and rolls along the outer wall surface of the wellbore. The positioning mechanism adopts a constant pressure propulsion method to ensure that the positioning roller can move on the curved barrel wall, driving the welding gun to always maintain a corresponding welding distance and ensuring stable and accurate welding.

[0012] Preferably, the welding unit further includes a hot air mechanism. The hot air mechanism includes a nozzle and an air supply pipe connected to the nozzle. The nozzle is fixed on the bracket and its air outlet is aligned with the above-mentioned welding area. The air supply pipe is externally connected to a hot air source. The hot air mechanism pre-heats the wellbore wall surface in the welding area, reduces the temperature difference between the welding area and the hot melt adhesive, makes the melting of the two uniform, and improves the weld quality.

[0013] A method for welding a plastic inspection wellbore branch pipe is as follows: A1. Input technical parameters such as the wellbore height, wellbore diameter, branch pipe hole diameter, hole elevation, and motor speed of the plastic inspection well to be processed into the human-machine interface of the controller; A2. Insert the lower end of the plastic inspection wellbore to be processed into the annular groove on the workbench; A3. Start the vertical lead screw motor to drive the vertical lead screw to rotate. The support platform rises along the vertical lead screw to the set height. Then continue to start the telescopic cylinder so that the piston rod extends, driving the support plate to translate outward and press-fit against the inner wall of the wellbore to form a cross-shaped inner support structure for the inner wall of the inspection wellbore, completing the fixation of the inspection wellbore; A4. Place the branch pipe on the pipe gripper. According to the size and length of the branch pipe, insert one end of the branch pipe into the interface hole of the inspection wellbore and tighten the pipe gripper to complete the fixation of the branch pipe; A5. Install the hot melt welding gun on the bracket. Adjust the tilt angle of the welding gun according to the hole size on the inspection wellbore so that the gun head of the welding gun is aligned with the welding area at the connection between the branch pipe and the hole; A6. Next, start the longitudinal lead screw motor to drive the longitudinal lead screw to rotate, driving the frame to move forward along the longitudinal guide rail to the designed position. Start the transverse lead screw motor to drive the transverse lead screw to rotate, driving the welding platform to move along the transverse guide rail to the designed position; A7. Next, start the propulsion cylinder. The piston rod of the propulsion cylinder extends and drives the bracket to move forward. The positioning roller moves forward with the bracket and contacts the outer surface of the wellbore. At the same time, the hot melt welding gun and the air nozzle also move forward with the bracket and are aligned with the welding area at the connection between the branch pipe and the hole; A8. Next, the controller sequentially turns on the hot air device and the hot melt welding gun. The air supply pipe blows out hot air through the air nozzle to heat the welding area. The hot melt welding gun starts to send out hot melt adhesive liquid to perform hot melt welding on the welding area at the connection; A9. Next, the controller starts the servo motor to drive the cross bar to rotate. The cross bar drives the sliding table to move along the circular track. At this time, the hot melt welding gun continuously performs hot melt welding on the welding area between the branch pipe and the hole to form an annular hot melt adhesive weld seam. Due to the constant pressure of the propulsion cylinder, the positioning roller always contacts and presses against the curved outer surface of the wellbore along the circumference of the hole, ensuring equidistant hot melt welding of the hot melt welding gun on the welding area; A10. When the first circle of annular hot melt welding is completed, the controller controls the longitudinal lead screw motor to run in reverse, driving the lead screw to rotate in the reverse direction by an angle and driving the frame to retreat according to the design requirements. Then the controller controls the servo motor to run in reverse, moving the hot melt welding gun in the reverse direction and performing the next circle of annular hot melt adhesive welding on the welding area again. In this way, multiple mutually stacked hot melt adhesive weld seams can be formed in the welding area; A11. After the welding is completed, the controller turns off the propulsion cylinder and the hot melt welding gun. The piston rod of the propulsion cylinder retracts and drives the bracket to move backward, exiting the welding operation; A12. Next, the controller closes the telescopic cylinder, and the piston rod of the telescopic cylinder retracts, driving the support plate to retract. At the same time, the controller reversely starts the lead screw motor, and the lead screw rotates reversely to lower the support platform, releasing the support and fixation of the inspection wellbore, and preparing for removing the inspection wellbore and the next hole-opening operation.

[0014] The beneficial effects of the present invention are as follows: The welding device adopts a telescopic support assembly with adjustable height, which can position and fix the wellbore as needed, and uses a hot melt welding gun and positioning rollers with adjustable weld position and angle to weld the branch pipe, enabling precise control of the branch pipe welding, smooth and flat welds, high welding efficiency, and low labor intensity, and meeting the requirements of high-quality industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention.

[0016] In the figure, 1. Workbench, 2. Inspection wellbore, 21. Branch pipe, 3. Height adjustment mechanism, 31. Guide rod, 32. Vertical lead screw, 33. Vertical lead screw motor, 4. Support mechanism, 41. Support platform, 42. Support assembly, 421. Telescopic cylinder, 422. Support plate, 5. Pipe gripper, 6. Moving mechanism, 61. Longitudinal guide rail, 62. Frame, 63. Longitudinal lead screw, 64. Longitudinal lead screw motor, 7. Rotating mechanism, 71. Circular track, 72. Slide table, 73. Servo motor, 74. Cross bar, 8. Welding mechanism, 81. Hot melt welding gun, 82. Transverse guide rail, 83. Transverse lead screw, 84. Transverse lead screw motor, 85. Welding platform, 86. Pushing cylinder, 9. Positioning mechanism, 91. Positioning rod, 92. Positioning roller. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions of the present invention will be further specifically described below through embodiments in conjunction with the drawings.

[0018] Embodiment: The plastic inspection wellbore branch pipe welding device of this embodiment, as Figure 1 shown, includes: A workbench 1 for placing the wellbore fixing unit, branch pipe clamping unit, branch pipe welding unit, and inspection wellbore 2; The wellbore fixing unit is used to position, clamp and fix the inspection wellbore, and includes a height adjustment mechanism 3 and a support mechanism 4. The height adjustment mechanism includes a guide rod 31 placed on the workbench, a vertical lead screw 32, and a vertical lead screw motor 33 for driving the vertical lead screw. The workbench is designed with a positioning ring groove 11 that matches the diameter of the inspection wellbore, and the groove width of the positioning ring groove matches the wall thickness of the inspection wellbore. The lower end of the inspection wellbore can be embedded in the positioning ring groove. The axis of the above-mentioned vertical lead screw coincides with the central axis of the positioning ring groove. The above-mentioned guide rod is installed on the workbench and perpendicular to the surface of the base. The above-mentioned vertical lead screw motor is electrically connected to the above-mentioned controller and drives the vertical lead screw to rotate; the support mechanism includes a support platform 41 and a telescopic support assembly 42 installed on the support platform. The above-mentioned support platform is sleeved on the vertical lead screw and the guide rod and rises and falls as the vertical lead screw rotates. The above-mentioned telescopic support assembly includes four telescopic cylinders 421 and arc-shaped support plates 422 installed at the ends of the piston rods of the telescopic cylinders. The four telescopic cylinders are installed on the support platform, and the directions of their piston rods are radially distributed in a cross shape with the center point of the support platform as the center. The telescopic cylinders are constant-pressure cylinders, which are electrically connected to the controller and connected to an external air source through an air pipe. The telescopic length of the piston rod of the telescopic cylinder matches the inner diameter of the inspection wellbore, and the arc-shaped support plate matches the inner wall arc surface of the inspection wellbore and fits the inner wall surface of the inspection wellbore; The branch pipe clamping unit is used to clamp and fix the branch pipe 21, and includes a pipe clamp 5 installed on the workbench; The branch pipe welding unit is used to weld the branch pipe, and includes a moving mechanism 6, a rotating mechanism 7, a welding mechanism 8, a positioning mechanism 9 and a hot air mechanism; Among them, the moving mechanism includes a longitudinal guide rail 62, a longitudinal lead screw 63, a longitudinal lead screw motor 64 installed on the workbench, and a frame 61 placed on the longitudinal guide rail. The longitudinal lead screw motor is electrically connected to the controller and drives the longitudinal lead screw to rotate, thereby driving the frame to move along the longitudinal guide rail; Among them, the rotating mechanism includes a servo motor 73 installed in the center of the frame, a cross bar 74 installed on the output shaft of the servo motor, a circular track 71 installed on the frame with the output shaft of the servo motor as the center, and a sliding table 72 sleeved on the circular track and moving along the circular track. The above-mentioned servo motor is electrically connected to the controller. The inner side of the above-mentioned sliding table is connected to the end of the cross bar. The output shaft of the servo motor drives the cross bar to rotate and drives the sliding table to move along the circular track; The welding mechanism includes a transverse guide rod 82, a transverse lead screw 83, a transverse lead screw motor 84, and a welding platform 85 disposed on the transverse lead screw and moving along the transverse lead screw. The above-mentioned transverse lead screw and transverse lead screw motor are fixed on the sliding table. The direction of the transverse lead screw faces the output shaft of the servo motor. The transverse lead screw motor is electrically connected to the controller and drives the transverse lead screw to rotate. A propulsion cylinder 86 is installed on the above-mentioned welding platform. A bracket 87 is installed at the end of the piston rod of the propulsion cylinder. The above-mentioned hot melt welding gun 81 is installed on the bracket. The hot melt welding gun is inclined inward and its head corresponds to the welding area at the connection between the branch pipe and the wellbore opening. The above-mentioned propulsion cylinder is electrically connected to the controller and is connected to an external air source through an air pipe; The positioning mechanism includes a positioning rod 91 and a positioning roller 92. The rear end of the positioning rod is fixed on the bracket and its direction is consistent with the axial direction of the longitudinal guide rail on the workbench. The positioning roller is installed at the front end of the positioning rod. The positioning roller abuts against the outer wall surface of the wellbore and rolls along the outer wall surface of the wellbore; The hot air mechanism includes a nozzle and an air supply pipe connected to the nozzle. The above-mentioned nozzle is installed on the bracket and its air outlet is aligned with the above-mentioned welding area. The above-mentioned air supply pipe is externally connected to a hot air source; The controller controls the wellbore fixing unit, the branch pipe clamping unit, and the branch pipe welding unit, and includes a human-machine interaction interface.

[0019] Welding method based on the above-mentioned welding device: First, insert the lower end of the inspection wellbore into the positioning ring groove on the workbench. Input technical parameters such as the corresponding wellbore height, wellbore diameter, branch pipe opening diameter, opening elevation, motor speed, etc. on the human-machine interface of the controller. Start the device. At this time, the controller first starts the vertical lead screw motor to drive the vertical lead screw to rotate. The support platform moves along the vertical lead screw and rises to the designed height. Open the telescopic cylinder to make the piston rod of the telescopic cylinder extend, push the support plate to move outward and fit and press against the inner wall of the wellbore, forming a cross-shaped internal support structure for the wellbore. Cooperating with the positioning of the lower positioning ring groove, the inspection wellbore is securely fixed on the base; then place the branch pipe on the pipe gripper. According to the size and length of the branch pipe, insert the front end of the branch pipe into the interface opening of the inspection wellbore, and fix the pipe gripper to complete the fixation of the branch pipe; then install the hot melt welding gun on the bracket, and adjust the inclination angle of the welding gun according to the opening size on the inspection wellbore so that the welding gun tip can be aligned with the welding area at the connection between the branch pipe and the opening; next, start the longitudinal lead screw motor and drive the longitudinal lead screw to rotate, driving the frame to move forward along the longitudinal guide rail to the designed position. Start the transverse lead screw motor to drive the transverse lead screw to rotate, driving the welding platform to move along the transverse guide rail to the designed position; start the propulsion cylinder to drive the bracket to move forward. The positioning rollers on the bracket move forward with the bracket and abut against the outer surface of the wellbore. At the same time, the hot melt welding gun and the air nozzle also move forward with the bracket and are aligned with the welding area at the connection between the branch pipe and the opening; next, turn on the hot air device and the hot melt welding gun in sequence. The air supply pipe blows out hot air through the air nozzle to heat the welding area. The hot melt welding gun starts to send out hot melt adhesive liquid to perform hot melt welding on the welding area at the connection. At the same time, the servo motor starts to run, driving the cross bar to rotate. The cross bar drives the slide table to move along the circular track. At this time, the hot melt welding gun continuously performs hot melt welding on the welding area with the rotation and movement of the slide table, forming the first annular hot melt adhesive weld seam. Due to the constant pressure of the propulsion cylinder, the positioning rollers always tightly abut against the curved outer surface of the wellbore opening circumference, ensuring equidistant hot melt welding of the hot melt welding gun on the welding area; when the first annular hot melt weld seam is completed, the longitudinal lead screw motor runs in reverse, driving the longitudinal lead screw to rotate in reverse and driving the frame to retreat a corresponding distance according to the design requirements. If necessary, the transverse lead screw motor can also be started to run and drive the transverse lead screw to rotate, driving the welding platform to retreat or advance along the transverse guide rail to the designed position. Then the servo motor runs in reverse to make the hot melt welding gun rotate and move in reverse to perform the next circle of annular hot melt welding on the welding area, forming the second weld seam that covers or overlaps the first weld seam. In this way, the hot melt welding gun can perform multiple circles of hot melt adhesive welding and form multiple mutually stacked hot melt adhesive weld seams to ensure the welding quality of the weld seams;After the welding is completed, the controller turns off the propulsion cylinder and the hot melt welding gun. The piston rod of the propulsion cylinder retracts and drives the bracket to move backward. The hot melt welding gun withdraws from the welding operation and exits the welding area. At the same time, the piston rod of the telescopic cylinder retracts and drives the support plate to retreat, releasing the internal support of the wellbore wall. The screw motor rotates in reverse and drives the support platform to descend and reset. The inspection wellbore can be removed as needed to prepare for the next welding of the device.;

[0020] In the description of the present invention, the technical terms "upper", "lower", "front", "rear", "left", "right", "longitudinal", "transverse", "inner", "outer", etc. indicating direction or position relationship are based on the direction or position relationship shown in the drawings, and are only for the convenience of describing and understanding the technical solution of the present invention. The above description does not limit the present invention, and the present invention is not limited to the examples described above. Any changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention shall be regarded as the protection scope of the present invention.

Claims

1. A plastic inspection wellbore branch pipe welding device, characterized in that, include: A workbench (1) is used to place a shaft fixing unit, a branch pipe clamping unit, a branch pipe welding unit, and an inspection shaft (2); A shaft fixing unit, used for positioning, clamping and fixing the inspection shaft, comprising a height adjustment mechanism (3) and a support mechanism (4), wherein the height adjustment mechanism comprises a guide rod (31) placed on a workbench, a vertical screw rod (32) and a vertical screw rod motor (33) for driving the vertical screw rod, and the support mechanism comprises a support platform (41) and a telescopic support assembly (42) placed on the support platform, wherein the support platform is sleeved on the vertical screw rod and rises and falls with the vertical screw rod; A branch pipe clamping unit, used for clamping and fixing the branch pipe (21), comprising a pipe clamp (5) fixedly mounted on a workbench; A branch pipe welding unit, used for welding branch pipes, comprises a moving mechanism (6), a rotating mechanism (7) and a welding mechanism (8), wherein the moving mechanism comprises a longitudinal guide rail (61) fixedly mounted on a workbench and a frame (62) mounted on the longitudinal guide rail and moving along the longitudinal guide rail, the rotating mechanism comprises a circular track (71) mounted on the frame and a slide table (72) mounted on the circular track and moving along the circular track, the welding mechanism is fixedly mounted on the slide table, and the welding mechanism comprises a hot melt welding gun (81); The controller controls the wellbore fixing unit, the branch pipe clamping unit and the branch pipe welding unit, including a human-machine interaction interface.

2. The plastic inspection wellbore branch pipe welding device according to claim 1, wherein: The workbench (1) is provided with a positioning ring groove (11) that matches the diameter of the inspection shaft (2), the groove width of the positioning ring groove matches the wall thickness of the inspection shaft, the lower end of the inspection shaft is embedded in the positioning ring groove, the axis of the vertical screw (32) coincides with the center axis of the positioning ring groove, the guide rod (31) is fixed to the base surface and is perpendicular to the base surface, the support platform (41) is sleeved on the vertical screw and the guide rod and rises and falls with the rotation of the vertical screw, and the vertical screw motor (33) is electrically connected to the controller.

3. The plastic inspection wellbore branch pipe welding device according to claim 1 or 2, characterized in that: The telescopic support assembly (42) comprises a plurality of telescopic cylinders (421) and an arc-shaped support plate (422) fixedly mounted on the end of the telescopic cylinder piston rod. The telescopic cylinder is fixedly mounted on the support platform and its piston rod radiates outward at equal angles with the center point of the support platform as the center. The telescopic cylinder is a constant pressure cylinder. The telescopic cylinder is electrically connected to the controller and connected to an external air source through an air pipe. The telescopic length of the telescopic cylinder piston rod matches the inner diameter of the inspection shaft (2). The support plate matches the inner wall arc surface of the inspection shaft and fits the inner wall surface of the inspection shaft.

4. The plastic inspection wellbore branch pipe welding device according to claim 3, characterized in that: The telescopic cylinders (421) are four in number and are evenly distributed on the support platform (41) at equal angles in a cross-circle shape.

5. The plastic inspection wellbore branch pipe welding device according to claim 4, characterized in that: The support plate (422) is a vacuum suction cup, a vacuum tube is provided on the back of the suction cup and is connected to an external vacuum device via a suction cup control valve, and the suction cup control valve is electrically connected to the controller.

6. The plastic inspection wellbore branch pipe welding device according to claim 1, characterized in that: The longitudinal movement mechanism (6) includes a longitudinal guide rail (61) fixed on the workbench, a longitudinal lead screw (63), a longitudinal lead screw motor (64), and a frame (62) placed on the longitudinal guide rail. The longitudinal lead screw motor drives the longitudinal lead screw to rotate and drives the frame to move along the longitudinal guide rail. The rotation mechanism (7) includes a servo motor (73) fixed at the center of the frame, a circular track (71) fixed on the frame with the output shaft of the servo motor as the center of the circle, and a slide table (72) sleeved on the circular track and moving along the circular track. A cross bar (74) is fixed on the output shaft of the servo motor. The inner side of the slide table is fixedly connected to the end of the cross bar. The output shaft of the servo motor drives the cross bar to rotate and drives the slide table to move along the circular track. The welding mechanism (8) includes a transverse guide rail (82), a transverse lead screw (83), a transverse lead screw motor (84), and a welding platform (85) placed on the transverse lead screw and moving along the transverse lead screw. The transverse lead screw and the transverse lead screw motor are fixed on the slide table. The transverse lead screw motor drives the transverse lead screw to rotate. The direction of the transverse lead screw faces the output shaft of the servo motor. A propulsion cylinder (86) is fixed on the welding platform. A bracket (87) is fixed at the end of the piston rod of the propulsion cylinder. A hot melt welding gun (81) is fixed on the bracket. The above-mentioned hot melt welding gun inclines inward and its head corresponds to the welding area at the connection between the branch pipe and the opening of the wellbore. The above-mentioned propulsion cylinder is electrically connected to the controller and is connected to an external air source through an air pipe.

7. The plastic inspection wellbore branch pipe welding device according to claim 6, characterized in that: The branch pipe welding unit further includes a positioning mechanism (9). The positioning mechanism includes a positioning rod (91) and a positioning roller (92). The rear end of the positioning rod is fixed on the bracket (87) and its direction is consistent with the axial direction of the longitudinal guide rail on the workbench. The positioning roller is fixed at the front end of the positioning rod. The positioning roller abuts against the outer wall surface of the wellbore and rolls along the outer wall surface of the wellbore.

8. The plastic inspection wellbore branch pipe welding device according to claim 6 or 7, characterized in that: The branch pipe welding unit further includes a hot air mechanism. The hot air mechanism includes a nozzle and an air supply pipe connected to the nozzle. The nozzle is fixed on the bracket and its air outlet is aligned with the above-mentioned welding area. The air supply pipe is externally connected to a hot air source.

9. A method for welding a branch pipe of a plastic inspection wellbore, the steps are as follows: A1. Input technical parameters such as the wellbore height, wellbore diameter, branch pipe opening diameter, opening elevation, and motor speed of the plastic inspection well to be processed into the human-machine interface of the controller; A2. Insert the lower end of the plastic inspection wellbore to be processed into the annular groove on the workbench; A3. Start the vertical lead screw motor and drive the vertical lead screw to rotate. The support platform rises along the vertical lead screw to the set height. Continue to start the telescopic cylinder to make the piston rod extend, drive the support plate to translate outward and press-fit against the inner wall of the wellbore constantly, forming a cross-shaped inner support structure on the inner wall of the inspection wellbore, and completing the fixation of the inspection wellbore; A4. Place the branch pipe on the pipe gripper. According to the size and length of the branch pipe, insert one end of the branch pipe into the interface opening of the inspection wellbore, and tighten the pipe gripper to complete the fixation of the branch pipe; A5. Install the hot melt welding gun on the bracket. Adjust the inclination angle of the welding gun according to the opening size on the inspection wellbore so that the gun head of the welding gun is aligned with the welding area at the connection between the branch pipe and the opening; A6. Next, start the longitudinal lead screw motor to drive the longitudinal lead screw to rotate, and drive the frame to move forward along the longitudinal guide rail to the designed position. Then start the transverse lead screw motor to drive the transverse lead screw to rotate, and drive the welding platform to move along the transverse guide rail to the designed position; A7. Next, start the propulsion cylinder. The piston rod of the propulsion cylinder extends and drives the bracket to move forward. The positioning roller moves forward with the bracket and contacts the outer surface of the wellbore. At the same time, the hot melt welding gun and the air nozzle also move forward with the bracket and are aligned with the welding area at the connection between the branch pipe and the opening; A8. Next, the controller sequentially turns on the hot air device and the hot melt welding gun. The air supply pipe blows out hot air through the air nozzle to heat the welding area. The hot melt welding gun starts to send out hot melt adhesive liquid to perform hot melt welding on the welding area at the connection; A9. Next, the controller starts the servo motor and drives the cross bar to rotate. The cross bar drives the sliding table to move along the circular track. At this time, the hot melt welding gun continuously performs hot melt welding on the welding area between the branch pipe and the opening to form a circular hot melt adhesive weld. Due to the constant pressure of the propulsion cylinder, the positioning roller always contacts and presses tightly against the curved outer surface of the wellbore along the circumference of the opening, ensuring equidistant hot melt welding of the hot melt welding gun to the welding area; A10. When the first circle of circular hot melt welding is completed, the controller controls the longitudinal lead screw motor to run in reverse, drives the lead screw to rotate in reverse by an angle and drives the frame to retreat according to the design requirements. Then the controller controls the servo motor to run in reverse to move the hot melt welding gun in reverse and perform the next circle of circular hot melt adhesive welding on the welding area again. In this way, multiple mutually stacked hot melt adhesive welds can be formed in the welding area; A11. After the welding is completed, the controller turns off the propulsion cylinder and the hot melt welding gun. The piston rod of the propulsion cylinder retracts and drives the bracket to move backward to withdraw from the welding operation; A12. Next, the controller turns off the telescopic cylinder. The piston rod of the telescopic cylinder retracts and drives the support plate to retract. At the same time, the controller reversely starts the lead screw motor. The lead screw rotates in reverse to lower the support platform, releasing the support and fixation of the inspection wellbore, and making preparations for removing the inspection wellbore and the next opening operation.

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