Narrow-gap weld joint welding device and welding method thereof

Abstract

The narrow-gap weld joint welding device comprises a welding power source, a wire feeder, a welding gun and a mechanical stirring device, the wire feeder is located above the welding gun, the positive electrode of the welding power source is connected with a welding wire in the welding gun, the negative electrode of the welding power source is connected with base metal, and the mechanical stirring device is located in front of the welding gun and comprises a gear motor, an eccentric wheel and a stirring rod. The outer surface of a stirring head of the stirring rod is provided with spiral protrusions and grooves which extend in the axial direction and are arranged at intervals, the upper end of the stirring rod and an output shaft of the gear motor are eccentrically connected with the eccentric wheel, and the included angle theta formed by the stirring rod and the welding gun in the extending direction of the welding seam ranges from 20 degrees to 50 degrees. The purpose of stirring the welding pool in the welding process is achieved through the stirring head with the spiral protrusions and the grooves which extend in the axial direction and are arranged at intervals, meanwhile, the stirring range of the stirring head is expanded through the design of the eccentric wheel, electric arc heat can be efficiently transmitted to the side wall, and therefore the welding seam quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and particularly to a narrow-gap weld welding device and a welding method thereof. Background Art

[0002] Narrow-gap gas metal arc welding is an efficient welding method specifically used for welding thick-wall structures. Its main feature is that by reducing the designed gap of the welding joint, the amount of filler material used and the welding time are significantly reduced, thereby improving the welding efficiency and economic benefits. The narrow-gap gas metal arc welding technology utilizes the concentrated heating characteristic of the arc in a narrow space, making the welding process more precise and controllable. In addition, since the heat input during the welding process is effectively controlled, the possibility of welding deformation is reduced, and at the same time, the quality and appearance of the weld are also improved.

[0003] However, in practical applications, especially in the micro-spacing welding scenario, there is a common problem with existing welding devices: the lack of effective agitation of the molten pool. This problem leads to the difficulty of the arc to directly and effectively heat the side walls, thereby affecting the welding quality. Specifically, due to the uneven distribution of arc energy, the area near the center of the welding torch is sufficiently heated, while the side walls on both sides often do not receive enough heat. This phenomenon is extremely likely to cause a series of welding quality problems, among which the most prominent is the side wall lack of fusion defect. Side wall lack of fusion not only weakens the mechanical properties of the weld, but may also cause serious problems such as cracks in the weld during use, greatly affecting the safety and reliability of the welded structure.

[0004] To solve the above problems, the usual approach is to use a mechanical stirrer to enhance the agitation effect of the molten pool. However, the conventional stirrer design is not suitable for the micro-spacing welding environment. On the one hand, due to the extremely limited space in micro-spacing welding, conventional-sized stirrers are difficult to operate flexibly in a narrow space; on the other hand, even if the stirrer can be applied to the micro-spacing welding environment, its agitation range is mainly limited around the end of the stirrer, and it is impossible to achieve effective agitation of the entire molten pool, especially the heating of the side wall part is still insufficient. Therefore, how to design a new method or device that can not only adapt to the micro-spacing welding environment but also effectively enhance the overall agitation effect of the molten pool, especially the side wall part, has become an urgent problem to be solved currently. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a narrow-gap weld welding device and a welding method, which use a stirring head with helical protrusions and grooves extending axially and arranged alternately to achieve the purpose of agitating the molten pool during the welding process. At the same time, through the design of an eccentric wheel, the agitation range of the stirring head is expanded, enabling the arc heat to be efficiently transferred to the side walls, thereby improving the weld quality.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A narrow-gap weld welding device includes a welding power source, a wire feeder, a welding torch, and a mechanical stirring device. The wire feeder is located above the welding torch and is used to feed the welding wire into the welding torch. The positive electrode of the welding power source is connected to the welding wire in the welding torch, and the negative electrode of the welding power source is connected to the base material. The mechanical stirring device is located in front of the welding torch and includes a reduction motor, an eccentric wheel, and a stirring rod. The stirring head of the stirring rod has spiral protrusions and grooves that extend axially and are arranged alternately on the outer surface. The upper end of the stirring rod and the output shaft of the reduction motor are eccentrically connected to the eccentric wheel. The stirring rod forms an angle θ of 20° to 50° with the welding torch in the extension direction of the weld. The reduction motor is connected to a stirring power source.

[0008] Further, the outer edge of the spiral protrusion at the stirring head is spindle-shaped. The edge of the spiral protrusion in the middle of the stirring head protrudes from the outer circumferential surface of the stirring rod, and the spiral protrusions, grooves, and the outer circumferential surface of the stirring rod are smoothly transitioned at the upper end of the stirring head.

[0009] Further, the eccentricity between the stirring rod and the output shaft of the reduction motor is 1 to 8 mm.

[0010] Further, the rotational speed adjustment range of the reduction motor is 0 to 500 rmp.

[0011] Further, the material of the stirring rod and the stirring head is one of tungsten, vanadium, and ceramic.

[0012] Further, a gas passage for introducing a shielding gas is provided inside the welding torch. One end of the gas passage is connected to a gas source, and the other end is connected to a shielding gas nozzle provided at the output end of the welding torch.

[0013] A welding method using the narrow-gap weld welding device according to any one of the above, includes the following steps:

[0014] S1: Fix the base material on a movable work platform, and then move the welding torch to directly above the groove between the base materials. Connect one end of the positive electrode of the welding power source to the welding wire in the welding torch, and connect one end of the negative electrode of the welding power source to the base material. Eccentrically connect the upper end of the stirring rod and the output shaft of the reduction motor to the eccentric wheel.

[0015] S2: Determine the current magnitude to be output by the welding power source during welding, the shielding gas flow rate output by the welding torch, the rotational speed of the reduction motor, and the moving speed of the work platform.

[0016] S3: Start the welding power source and the work platform, start the welding torch to generate a welding arc, the wire feeder feeds the welding wire to the welding torch and starts welding, and a weld pool is formed on the surface of the base material.

[0017] S4: Move the stirring rod so that the stirring head extends into the welding pool, and the stirring rod forms an angle θ of 20° to 50° with respect to the welding torch in the extending direction of the groove. Then start the reduction motor to stir the welding pool.

[0018] S5: After the groove welding is completed, turn off the welding power supply, the working platform, the welding torch and the reduction motor. After the base material cools down to room temperature, take it out to complete the welding.

[0019] Further, in step S2, the moving speed of the working platform is 2 - 5 mm / s.

[0020] Further, the distance from the output end of the welding torch to the surface of the groove is 6 - 10 mm; the shielding gas in the welding torch is nitrogen or helium, and its gas flow rate during operation is 10 - 20 L / min.

[0021] Further, the stirring head is immersed in the welding pool by 0.5 - 2 mm.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. The present invention uses the spiral protrusions and grooves on the stirring head to stir the molten metal in the welding pool, forming a spiral convection field near the stirring head, which helps to evenly distribute the arc heat, reduces the occurrence of sidewall lack of fusion defects, and effectively reduces the probability of porosity. At the same time, the unique eccentric wheel design further expands the stirring range of the stirring head, ensuring that the arc heat can be more evenly transmitted to the entire welding pool, thereby achieving an efficient and uniform heating effect. The synergistic effect of the two can greatly improve the quality and reliability of the weld.

[0024] 2. The diameter of the stirring rod in the present invention is only 0.5 - 1.5 mm, and the eccentricity between the stirring rod and the output shaft of the reduction motor is only 1 - 8 mm, which makes this device very suitable for the micro-spacing welding environment with extremely limited space. At the same time, by designing the angle between the stirring rod and the welding torch to be 20° - 50° and setting the speed adjustment range of the reduction motor to 0 - 500 rmp, it can adapt to different welding conditions and requirements.

[0025] 3. The present invention selects one of tungsten, vanadium, and ceramics as the material of the stirring rod and the stirring head, which can maintain a stable and efficient operating state under extreme working conditions, thereby further improving the overall performance and service life of the device. Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of the narrow-gap weld welding device described in the present invention.

[0027] Figure 2 It is a schematic structural diagram of the mechanical stirring device described in the present invention.

[0028] The reference numerals are as follows:

[0029] 1 - welding power source; 2 - wire feeder; 3 - welding torch; 4 - base material; 5 - groove; 6 - stirring rod; 7 - stirring power source; 8 - weld pool; 9 - reduction motor; 10 - eccentric wheel; 11 - stirring head. Detailed implementation manners

[0030] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0031] The narrow-gap weld welding device described in this embodiment includes a welding power source 1, a wire feeder 2, a welding torch 3, and a mechanical stirring device. Figure 1 This is a schematic structural diagram of the narrow-gap weld welding device described in this embodiment.

[0032] The wire feeder 2 is located above the welding torch 3 and is used to feed the welding wire into the welding torch 3. A gas passage for passing a shielding gas is provided inside the welding torch 3. One end of the gas passage is connected to a gas source, and the other end is connected to a shielding gas nozzle provided at the output end of the welding torch 3. The positive electrode of the welding power source 1 is connected to the welding wire in the welding torch 3, and the negative electrode of the welding power source 1 is connected to the base material. The mechanical stirring device is located in front of the welding torch 3 and includes a reduction motor 9, an eccentric wheel 10, and a stirring rod 6. The stirring head 11 of the stirring rod 6 has spirally extending and alternately arranged protrusions and grooves on its outer surface. The outer edge of the spirally extending protrusion at the stirring head 11 is spindle-shaped. The edge of the spirally extending protrusion in the middle of the stirring head 11 protrudes from the outer circumferential surface of the stirring rod 6, and at the upper end of the stirring head 11, the spirally extending protrusions, grooves and the outer circumferential surface of the stirring rod 6 are smoothly transitioned. The materials of the stirring rod 6 and the stirring head 11 are one of tungsten, vanadium, and ceramics. The upper end of the stirring rod 6 and the output shaft of the reduction motor 9 are eccentrically connected to the eccentric wheel 10. The eccentricity between the stirring rod 6 and the output shaft of the reduction motor 9 is 1 - 8 mm. The stirring rod 6 forms an angle θ of 20° - 50° with the welding torch 3 in the extending direction of the weld 5. The reduction motor 9 is connected to the stirring power source 7, and the rotational speed adjustment range of the reduction motor 9 is 0 - 500 rmp. Figure 2 This is a schematic structural diagram of the mechanical stirring device described in this embodiment.

[0033] The welding method using the above narrow-gap weld welding device includes the following steps:

[0034] S1: Fix the base material 4 on a movable working platform, and then move the welding torch 3 to directly above the groove 5 between the base materials; connect one end of the positive electrode of the welding power source 1 to the welding wire in the welding torch 3, and connect one end of the negative electrode of the welding power source 1 to the base material 4; eccentrically connect the upper end of the stirring rod 6 and the output shaft of the reduction motor 9 to the eccentric wheel 10.

[0035] S2: Determine the magnitude of the current that the welding power source 1 should output during welding, the flow rate of the shielding gas output by the welding torch 3, the rotational speed of the reduction motor 9, and the moving speed of the working platform;

[0036] S3: Start the welding power source 1 and the working platform, start the welding torch 3 to generate a welding arc, the wire feeder 2 conveys the welding wire to the welding torch 3 and starts welding, and a weld pool 8 is formed on the surface of the base material 4;

[0037] S4: Move the stirring rod 6 so that the stirring head 11 extends into the weld pool 8, and the stirring rod 6 forms an angle θ of 20° to 50° with respect to the welding torch 3 in the extending direction of the groove 5, and then start the reduction motor 9 to start stirring the weld pool 8;

[0038] S5: After the welding of the groove 5 is completed, turn off the welding power source 1, the working platform, the welding torch 3 and the reduction motor 9, and take out the base material 4 after it cools to room temperature to complete the welding.

[0039] Among them, the moving speed of the working platform is 2 - 5 mm / s, the distance from the output end of the welding torch 3 to the surface of the groove 5 is 6 - 10 mm, the shielding gas in the welding torch 3 is nitrogen or helium, and its gas flow rate during operation is 10 - 20 L / min, and the stirring head 11 is immersed in the weld pool by 0.5 - 2 mm.

[0040] The above embodiments are the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Without departing from the essence of the present invention, any obvious improvements, substitutions or variations that those skilled in the art can make all fall within the protection scope of the present invention.

Claims

1. A narrow gap welding device, characterized in that: The invention comprises a welding power source (1), a wire feeder (2), a welding gun (3) and a mechanical stirring device; the wire feeder (2) is located above the welding gun (3) and is used to feed the welding wire into the welding gun (3); the positive electrode of the welding power source (1) is connected to the welding wire in the welding gun (3), and the negative electrode of the welding power source (1) is connected to the base material; the mechanical stirring device is located in front of the welding gun (3), and comprises a reduction motor (9), an eccentric wheel (10) and a stirring rod (6); the stirring head (11) of the stirring rod (6) has a spiral protrusion and groove extending in the axial direction and arranged alternately on the outer surface, and the upper end of the stirring rod (6) and the output shaft of the reduction motor (9) are eccentrically connected to the eccentric wheel (10); the stirring rod (6) forms an angle θ of 20° to 50° with the welding gun (3) in the extension direction of the weld (5); the reduction motor (9) is connected to the stirring power source (7).

2. The welding pool stirring micro-pitch welding device according to claim 1, characterized in that: The outer edge of the spiral protrusion at the stirring head (11) is spindle-shaped, the edge of the spiral protrusion in the middle of the stirring head (11) protrudes from the outer circumferential surface of the stirring rod (6), and the spiral protrusion and the groove at the upper end of the stirring head (11) smoothly transition to the outer circumferential surface of the stirring rod (6).

3. The welding pool stirring micro-pitch welding device according to claim 1, characterized in that: The eccentricity between the stirring rod (6) and the output shaft of the reduction motor (9) is 1 to 8 mm.

4. The welding pool stirring fine pitch welding device according to claim 1, characterized in that: The speed adjustment range of the reduction motor (9) is 0 to 500 rpm.

5. The welding pool stirring micro-pitch welding device according to claim 1, characterized in that: The material of the stirring rod (6) and the stirring head (11) is one of tungsten, vanadium and ceramic.

6. The welding pool stirring micro-pitch welding device according to claim 1, characterized in that: A gas channel for introducing protective gas is provided inside the welding gun (3); one end of the gas channel is connected to a gas source, and the other end is connected to a protective gas nozzle provided at the output end of the welding gun (3).

7. A welding method using the narrow gap welding device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Fix the base material (4) on a movable working platform, then move the welding gun (3) to the position directly above the groove (5) between the base materials; connect the positive end of the welding power source (1) to the welding wire in the welding gun (3), and connect the negative end of the welding power source (1) to the base material (4); eccentrically connect the upper end of the stirring rod (6) and the output shaft of the reduction motor (9) to the eccentric wheel (10); S2: determining the current that the welding power source (1) should output, the flow rate of the shielding gas output by the welding gun (3), the rotation speed of the reduction motor (9), and the moving speed of the working platform during welding; S3: starting the welding power source (1) and the working platform, starting the welding gun (3) to generate a welding arc, the wire feeder (2) feeds the welding wire to the welding gun (3) and starts welding, and a welding pool (8) is formed on the surface of the base material (4); S4: moving the stirring rod (6) so that the stirring head (11) extends into the welding pool (8), and the stirring rod (6) forms an angle θ of 20° to 50° relative to the welding gun (3) in the extension direction of the groove (5), and then starting the reduction motor (9) to start stirring the welding pool (8); S5: After the groove (5) is welded, the welding power source (1), the working platform, the welding gun (3) and the reduction motor (9) are turned off, and the base material (4) is taken out after cooling to room temperature, thereby completing the welding.

8. The welding method according to claim 7, characterized in that: In step S2, the moving speed of the working platform is 2-5 mm / s.

9. The welding method according to claim 7, characterized in that: The distance between the output end of the welding gun (3) and the surface of the groove (5) is 6 to 10 mm; the protective gas in the welding gun (3) is nitrogen or helium, and the gas flow rate during operation is 10 to 20 L / min.

10. The welding method according to claim 7, characterized in that: The stirring head (11) is immersed in the welding pool (8) by 0.5 to 2 mm.

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