Automatic welding bottoming local inner protection device and method

Abstract

The invention provides an automatic welding bottoming local inner protection device and method, the protection device comprises a supporting mechanism and an argon filling mechanism, the supporting mechanism comprises an adjustable lifting support, and the argon filling mechanism is arranged on the adjustable lifting support. The adjustable lifting support is of a multi-stage shear fork type structure, the multi-stage shear fork type structure is connected with two center transverse rods, the two center transverse rods are in threaded connection with the same hollow lead screw, the hollow lead screw is connected with a gear motor, one center transverse rod is fixed to the gear motor, and the other center transverse rod can horizontally move along the hollow lead screw. The adjustable lifting support is adopted in the supporting mechanism, the supporting mechanism is suitable for supporting of different pipe diameters by adjusting the height of the adjustable lifting support, and the problem that an existing argon filling device is single in applicability is solved. According to the argon filling mechanism, the tumbler principle is adopted, torsion is fully released through a balance weight, a positioning bearing and a follow-up rotating bearing, the protective cover is always located at the fixed position, the stable and balanced state of the protective cover is kept, and the welding seam is continuously protected.

Description

Technical Field

[0001] This invention belongs to the field of automatic argon arc welding technology, specifically relating to an automatic welding root pass local internal protection device and method. Background Technology

[0002] When using automated TIG welding to weld pipes made of austenitic stainless steel, nickel-based alloys, medium- and high-alloy heat-resistant steel, and titanium alloys, the high alloy content necessitates internal argon purging protection during the root pass to prevent oxidation of the weld. Traditional protection methods use water-soluble paper, cardboard, sponge board, or rubber sheeting to create a gas chamber, but these methods are inefficient and require a long preparation time to reach welding conditions. Especially when welding chromium-molybdenum heat-resistant steel requiring high preheating temperatures, avoiding the high-temperature preheating zone increases the gas chamber volume, consuming large amounts of argon and significantly extending the purging time, resulting in substantial waste of materials and personnel. Using high-temperature resistant materials or specialized argon purging devices for sealing is difficult to remove for long pipe sections. All of these factors significantly limit the efficiency advantages of automated welding.

[0003] When welding standards are high and quality control is stringent, conventional argon purging methods are no longer sufficient for the root pass welding of automated welding systems. This is especially true for important high-temperature nickel-based alloys, duplex stainless steels, titanium alloys, and other pipelines with stringent corrosion resistance requirements, where the back weld and heat-affected zone must be silver-white or golden-yellow in color. Existing argon purging methods or devices have large gas chamber volumes and low internal air removal efficiency. Even with extended purging times, it is difficult to fully achieve the required color, resulting in a significant waste of argon gas.

[0004] Therefore, researching local internal protection devices for the root pass of automated pipeline welding and overcoming the bottleneck of argon purging protection is essential to better leverage the efficiency advantages of automated welding. This is especially important given the shortage of welders and rising labor costs.

[0005] During automatic argon arc welding for the root pass, the pipe rotates while the welding torch remains stationary. Only by continuously providing local protection to the internal weld seam and heat-affected zone at the flat welding position can the welding quality be guaranteed.

[0006] The technical solution disclosed in Invention Patent 202110212628.8, an automatic tungsten inert gas (TIG) welding protection device for titanium pipes, includes a cover, a gas pipe, a drag cover clamping plate, and an automatic welding gun fixing clamp. Multiple covers are sequentially hinged to form a drag cover. An elastic element is provided between the cover at one end and the drag cover clamping plate. The drag cover clamping plate has a groove, and each cover is connected to a gas pipe, which passes through the groove of the drag cover clamping plate and connects to an argon gas source. The drag cover clamping plate is connected to the automatic welding gun fixing clamp to fix the automatic welding gun tube. This patent ensures the continuity and effectiveness of weld gas protection during continuous welding of titanium pipes. By setting a groove on the drag cover clamping plate, the gas pipe moves with the cover as it moves, maintaining gas supply.

[0007] However, when the tube rotates, the argon filling device (the back argon filling device integrated with the mouthpiece) of the above-mentioned patent has a complex structure, large size, high cost, and a single applicable range of pipe diameters. Each type of pipe inner diameter requires a set of devices, and it is difficult to remove it from the inside when the pipeline is very long or has a large curvature. Summary of the Invention

[0008] The purpose of this invention is to provide an automatic welding root pass local protection device to overcome the above-mentioned technical problems existing in the prior art.

[0009] Another objective of this invention is to provide an automatic welding root pass local internal protection method that economically, efficiently, and effectively meets the requirements for internal protection during automatic argon arc welding root pass.

[0010] Therefore, the technical solution provided by the present invention is as follows: An automatic welding root pass local internal protection device includes a support mechanism and an argon filling mechanism. The support mechanism includes an adjustable lifting bracket, and the argon filling mechanism is mounted on the adjustable lifting bracket. The adjustable lifting bracket is a multi-stage scissor-type structure. The multi-stage scissor-type structure is connected to two central crossbars. The two central crossbars are threadedly connected to the same hollow screw. The hollow screw is connected to a reduction motor. One of the central crossbars is fixed to the reduction motor, while the other central crossbar can move horizontally along the hollow screw.

[0011] The argon filling mechanism includes a hollow connecting rod, a hollow telescopic rod, and a protective cover connected in sequence. One end of the hollow connecting rod is connected to an argon cylinder. The hollow connecting rod is located inside a hollow lead screw. The hollow connecting rod and the hollow lead screw are connected by a torque release device.

[0012] It also includes a controller, a battery, and a remote controller. The controller and battery are both connected to the geared motor, and the remote controller is used to send signals to the controller to control the forward and reverse rotation of the geared motor.

[0013] The torque release device includes a bearing retainer, a positioning bearing, a follower bearing, and a counterweight. The bearing retainer is connected to the other end of the hollow connecting rod. The counterweight is connected to the bearing retainer. There are two positioning bearings located at both ends inside the hollow lead screw. The follower bearing is nested inside the bearing retainer.

[0014] The protective cover is made of copper plate, and a foamed copper filter screen is installed inside the protective cover. The foamed copper filter screen is connected to the protective cover by threads.

[0015] The counterweight and bearing retainer are connected by a positioning bolt, and the hollow telescopic rod is provided with a positioning bolt.

[0016] The adjustable lifting bracket has eight wheels symmetrically arranged on its upper and lower parts, and the wheel axis is perpendicular to the axis of the argon filling mechanism.

[0017] A method for local internal protection during automatic welding root pass, using an automatic welding root pass local internal protection device, includes the following steps: Step 1) Insert the hollow connecting rod of the argon filling mechanism into the hollow lead screw and positioning bearing of the support mechanism, and connect the end of the hollow connecting rod to the argon cylinder; Step 2) Place the argon filling mechanism inside the pipe, turn on the reduction motor, and raise the adjustable lifting bracket to tighten the inner wall of the pipe; Step 3) Adjust the width of the protective cover to position it at the appropriate center of the weld. Then adjust the height of the hollow telescopic rod to make the protective cover fit the inner wall of the pipe. Then fix the height of the hollow telescopic rod. The next step is to complete the weld assembly. Step 4) Open the argon cylinder, and the automatic welding fixture clamps the pipe and rotates and welds it to achieve automatic welding of the root pass and local internal protection.

[0018] During the rotation of the pipe clamped by the automatic welding fixture, the argon filling device and support mechanism rotate with the pipe. The argon filling mechanism releases the torsional force generated by the pipe rotation through the positioning bearing, the follower bearing and the counterweight, so that the protective cover is stable and balanced and continuously protects the weld.

[0019] The beneficial effects of this invention are: The automatic welding root pass local internal protection device provided by this invention adopts an adjustable lifting bracket as the support mechanism. The hollow screw is driven to rotate forward and backward by a geared motor to adjust the height of the adjustable lifting bracket. It is suitable for supporting different pipe diameters and solves the problem of limited applicability of previous argon filling devices.

[0020] This invention employs the principle of a self-righting toy. When the pipe rotates during the welding process, the torque is fully released through the counterweight, positioning bearing, and follow-rotating bearing, so that the protective cover remains in a fixed position, maintaining its stable balance and continuously protecting the weld.

[0021] The hollow connecting rod of this invention not only connects the various components but also conducts argon gas, eliminating the need for argon hoses and avoiding pipe entanglement during rotation. It also boasts excellent heat resistance, particularly beneficial when welding chromium-molybdenum heat-resistant steel requiring preheating, preventing the burn-out associated with traditional rubber hoses. The hollow lead screw can adjust the height of the support mechanism and connect to the argon filling mechanism via a nested connection. The hollow telescopic rod employs a three-section lifting structure, ensuring a tight seal with a high-temperature resistant sealing ring. It allows for adjustment of the distance between the protective cover and the inner wall of the pipe to accommodate different diameters, offering a wide range of adaptability.

[0022] The protective cover of this invention has an adjustable angle to adapt to changes in the curvature of different pipe diameters, fits the pipe wall better, and expands the application range. The air outlet of the protective cover uses a foamed copper filter screen to make the airflow more uniform and effectively avoid gas turbulence. The protective effect is particularly outstanding when welding heat-sensitive materials such as nickel-based alloys and titanium alloys, avoiding the problem of reduced corrosion resistance caused by poor protection. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of one embodiment of the present invention; Figure 2 This is a schematic diagram of one embodiment of the argon filling mechanism of the present invention; Figure 3 This is a cross-sectional view of one embodiment of the present invention.

[0024] In the diagram: 1. Gear motor; 2. Hollow lead screw; 3. Positioning bearing; 4. Battery; 5. Controller; 6. Remote control; 7. Adjustable lifting bracket; 8. Center crossbar; 9. Wheel; 10. Hollow connecting rod; 11. Counterweight; 12. Rotating bearing; 13. Bearing retainer; 14. Hollow telescopic rod; 15. Protective cover; 16. Foamed copper filter screen; 17. Positioning bolt one; 18. Positioning bolt two. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0026] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0027] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0028] Example 1 The present invention provides an automatic welding root pass local internal protection device, including a support mechanism and an argon filling mechanism. The support mechanism includes an adjustable lifting bracket 7, and the argon filling mechanism is disposed on the adjustable lifting bracket 7. The automatic welding root pass local internal protection device provided by this invention adopts an adjustable lifting bracket 7 as the support mechanism, which is suitable for supporting different pipe diameters and solves the problem of limited applicability of previous argon filling devices.

[0029] Example 2 Based on Example 1, this example provides an automatic welding root pass local internal protection device, such as... Figure 1 As shown, the adjustable lifting bracket 7 is a multi-stage scissor structure. The multi-stage scissor structure is connected to two central crossbars 8. The two central crossbars 8 are threadedly connected to the same hollow screw. The hollow screw is connected to a reduction motor 1. One of the central crossbars 8 is fixed to the reduction motor 1, while the other central crossbar 8 can move horizontally along the hollow screw.

[0030] In this embodiment, the geared motor 1 is a 12-volt dual-shaft worm gear DC geared motor 1, which is bolted to a central crossbar 8. The central crossbar 8 is then connected to a multi-stage scissor-type structure to support the geared motor 1. The adjustable lifting bracket 7 is connected to each other with double-headed rivets, allowing for free movement.

[0031] By rotating the geared motor 1 in both directions, the hollow lead screw is driven to rotate, causing the other central crossbar 8 to move back and forth, thereby realizing the lifting of the multi-stage scissor-type structure and enabling the adjustable lifting bracket 7 to be tightened and loosened within a pipe with a diameter of 300-1000mm.

[0032] Example 3 Based on Example 2, this example provides an automatic welding root pass local internal protection device, such as... Figure 2 As shown, the argon filling mechanism includes a hollow connecting rod 10, a hollow telescopic rod 14, and a protective cover 15 connected in sequence. One end of the hollow connecting rod 10 is connected to an argon cylinder. The hollow connecting rod 10 is located inside a hollow lead screw. The hollow connecting rod 10 and the hollow lead screw are connected by a torque release device.

[0033] The hollow connecting rod 10 is used to connect the various components of the argon filling mechanism and can also serve as a pipeline for conveying argon gas. The hollow connecting rod 10 passes horizontally through the hollow lead screw 2 and two positioning bearings 3 of the support mechanism in a nested manner. The hollow telescopic rod 14 is connected to the hollow connecting rod 10 and the protective cover 15. The hollow telescopic rod 14 has a three-section structure with nested connections and uses a high-temperature resistant sealing ring to ensure its sealing effect. The height of the protective cover 15 can be adjusted by telescopic extension to accommodate weld protection for different pipe diameters. One end of the hollow connecting rod 10 is connected to the argon cylinder, and the other end is connected to the hollow telescopic rod, used to convey argon gas to the protective cover 15.

[0034] Example 4 Based on Embodiment 2, this embodiment provides an automatic welding root pass local internal protection device, which also includes a controller 5, a battery 4 and a remote controller 6. The controller 5 and the battery 4 are both connected to the geared motor 1. The remote controller 6 is used to send signals to the controller 5 to control the geared motor 1 to rotate forward and backward.

[0035] like Figure 1 As shown, in this embodiment, battery 4 is a set of four 12V high-performance DC batteries, providing power to the geared motor 1. Battery 4 is connected to controller 5, forming an integrated control box. Remote controller 6 is wirelessly connected to controller 5, indirectly controlling the geared motor 1. Controller 5 is connected to geared motor 1 and can control the forward and reverse rotation of geared motor 1, thereby controlling the reciprocating movement of the central crossbar 8.

[0036] Example 5 Based on Example 3, this example provides an automatic welding root pass local internal protection device, such as... Figure 3 As shown, the torque release device includes a bearing retainer 13, a positioning bearing 3, a follower bearing 12, and a counterweight 11. The bearing retainer 13 is connected to the other end of the hollow connecting rod 10. The counterweight 11 is connected to the bearing retainer 13. There are two positioning bearings 3, which are located at both ends inside the hollow lead screw. The follower bearing 12 is nested inside the bearing retainer 13.

[0037] There are two positioning bearings 3, connected to the hollow lead screw 2, and located at both ends inside the hollow lead screw 2. Bearing retainers 13 are connected to the hollow connecting rod 10, serving a fixing function. A counterweight 11 is connected to the bearing retainer 13, ensuring that the bearing retainer 13 is always in a vertically upward position. A follower bearing 12 is nested inside the bearing retainer 13, forming a double-safety mechanism with the two positioning bearings 3 inside the hollow lead screw 2 of the support mechanism. When the pipe rotates, the follower bearing 12 ensures that the torque generated by the rotation is fully released, keeping the protective cover 15 in a fixed position on the pipe. This prevents displacement of the protective cover 15 when the pipe rotates, ensuring the normal operation of the protection device.

[0038] Example 6 Based on Embodiment 3, this embodiment provides an automatic welding root pass local internal protection device. The protective cover 15 is a copper plate, and a foamed copper filter 16 is provided inside the protective cover 15. The foamed copper filter 16 is connected to the protective cover 15 by threads.

[0039] In this embodiment, the protective cover 15 is made of 1mm thick copper plate, which provides good heat dissipation under high welding temperatures, preventing the protective cover 15 from deforming due to heat. The foamed copper filter 16 is connected to the protective cover 15, making the airflow more uniform and enhancing the local protection effect.

[0040] Example 7 Based on Embodiment 5, this embodiment provides an automatic welding root pass local internal protection device, wherein the counterweight 11 and the bearing retaining ring 13 are connected by a positioning bolt 17, and the hollow telescopic rod is provided with a positioning bolt 18.

[0041] like Figure 2 As shown, positioning bolt 17 is used to adjust the position of counterweight 11 on bearing retainer 13, thereby changing the angle of protective cover 15; positioning bolt 18 is used to adjust the height of hollow telescopic rod 14 to adapt to different pipe diameters.

[0042] Example 8 Based on Embodiment 1, this embodiment provides an automatic welding root pass local internal protection device. The adjustable lifting bracket 7 is symmetrically provided with eight wheels 9 on its upper and lower parts, and the axial direction of the wheels 9 is perpendicular to the axial direction of the argon filling mechanism.

[0043] After welding is completed, use remote control 6 to reverse the gear motor 1 and release the support mechanism. Figure 1 and Figure 2 As shown, by rotating wheel 9, the automatic welding root pass local protection device can be easily pulled out from inside the pipe.

[0044] Example 9 This embodiment provides a method for local internal protection during automatic welding root pass, including the following steps: Step 1) Insert the hollow connecting rod of the argon filling mechanism into the hollow lead screw and positioning bearing 3 of the support mechanism, and connect the end of the hollow connecting rod to the argon cylinder; Step 2) Place the argon filling mechanism inside the pipe, turn on the reduction motor 1, and raise the adjustable lifting bracket 7 to tighten the inner wall of the pipe; Step 3) Adjust the width of the protective cover 15 to place it at an appropriate position in the center of the weld. Then adjust the height of the hollow telescopic rod 14 so that the protective cover 15 fits against the inner wall of the pipe. Then fix the height of the hollow telescopic rod 14. The next step is to complete the weld assembly. Step 4) Open the argon cylinder, and the automatic welding fixture clamps the pipe and rotates and welds it to achieve automatic welding of the root pass and local internal protection.

[0045] During the rotation of the pipe clamped by the automatic welding fixture, the argon filling device and support mechanism rotate with the pipe. The argon filling mechanism releases the torsional force generated by the pipe rotation through the positioning bearing 3, the follower bearing 12 and the counterweight 11, so that the protective cover 15 is stable and balanced, and continuously protects the weld.

[0046] In summary, the support mechanism of this invention employs an adjustable lifting bracket 7. The hollow lead screw 2 is driven by a reduction motor 1 to rotate forward and backward, adjusting the height of the adjustable lifting bracket 7. This makes it suitable for supporting pipes of different diameters, solving the problem of limited applicability of previous argon filling devices. The argon filling mechanism utilizes a self-righting principle. When the pipe rotates during welding, the torque is fully released through the counterweight 11, positioning bearing 3, and follower bearing 12, ensuring that the protective cover 15 remains in a fixed position, maintaining its stable balance and continuously protecting the weld.

[0047] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. An automatic welding root pass local internal protection device, characterized in that: It includes a support mechanism and an argon filling mechanism. The support mechanism includes an adjustable lifting bracket, and the argon filling mechanism is mounted on the adjustable lifting bracket.

2. The automatic welding root pass local internal protection device according to claim 1, characterized in that: The adjustable lifting bracket is a multi-stage scissor-type structure. The multi-stage scissor-type structure is connected to two central crossbars. The two central crossbars are threadedly connected to the same hollow screw. The hollow screw is connected to a reduction motor. One of the central crossbars is fixed to the reduction motor, while the other central crossbar can move horizontally along the hollow screw.

3. The automatic welding root pass local internal protection device according to claim 2, characterized in that: The argon filling mechanism includes a hollow connecting rod, a hollow telescopic rod, and a protective cover connected in sequence. One end of the hollow connecting rod is connected to an argon cylinder. The hollow connecting rod is located inside a hollow lead screw. The hollow connecting rod and the hollow lead screw are connected by a torque release device.

4. The automatic welding root pass local internal protection device according to claim 2, characterized in that: It also includes a controller, a battery, and a remote controller. The controller and battery are both connected to the geared motor, and the remote controller is used to send signals to the controller to control the forward and reverse rotation of the geared motor.

5. The automatic welding root pass local internal protection device according to claim 3, characterized in that: The torque release device includes a bearing retainer, a positioning bearing, a follower bearing, and a counterweight. The bearing retainer is connected to the other end of the hollow connecting rod. The counterweight is connected to the bearing retainer. There are two positioning bearings located at both ends inside the hollow lead screw. The follower bearing is nested inside the bearing retainer.

6. The automatic welding root pass local internal protection device according to claim 3, characterized in that: The protective cover is made of copper plate, and a foamed copper filter screen is installed inside the protective cover. The foamed copper filter screen is connected to the protective cover by threads.

7. The automatic welding root pass local internal protection device according to claim 5, characterized in that: The counterweight and bearing retainer are connected by a positioning bolt, and the hollow telescopic rod is provided with a positioning bolt.

8. An automatic welding root pass local internal protection device according to any one of claims 1-7, characterized in that: The adjustable lifting bracket has eight wheels symmetrically arranged on its upper and lower parts, and the wheel axis is perpendicular to the axis of the argon filling mechanism.

9. A method for local internal protection during automatic welding root pass, using the local internal protection device for automatic welding root pass as described in claim 5, characterized in that: Includes the following steps: Step 1) Insert the hollow connecting rod of the argon filling mechanism into the hollow lead screw and positioning bearing of the support mechanism, and connect the end of the hollow connecting rod to the argon cylinder; Step 2) Place the argon filling mechanism inside the pipe, turn on the reduction motor, and raise the adjustable lifting bracket to tighten the inner wall of the pipe; Step 3) Adjust the width of the protective cover to position it at the appropriate center of the weld. Then adjust the height of the hollow telescopic rod to make the protective cover fit the inner wall of the pipe. Then fix the height of the hollow telescopic rod. The next step is to complete the weld assembly. Step 4) Open the argon cylinder, and the automatic welding fixture clamps the pipe and rotates and welds it to achieve automatic welding of the root pass and local internal protection.

10. The automatic welding root pass local internal protection method according to claim 9, characterized in that: During the rotation of the pipe clamped by the automatic welding fixture, the argon filling device and support mechanism rotate with the pipe. The argon filling mechanism releases the torsional force generated by the pipe rotation through the positioning bearing, the follower bearing and the counterweight, so that the protective cover is stable and balanced and continuously protects the weld.

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