Ultrasonic assisted underwater arc welding device and method

Abstract

The present invention discloses an ultrasonic-assisted underwater arc welding device and method, comprising a welding gun, a coupler and an ultrasonic-assisted device. The welding gun comprises a first barrel, a second barrel and a connecting piece, a conductive nozzle is installed at the end of the second barrel, and the connecting piece is fixed between the first barrel and the second barrel to conduct the current of the first barrel to the second barrel. The coupler is an insulator and connects the first barrel and the second barrel, and the welding wire extends from the conductive nozzle to the welding point after passing through the first barrel, the coupler and the second barrel. The ultrasonic-assisted device of the present invention passes through the coupler and abuts against the welding wire, and directly controls the arc and the molten droplet by vibrating the welding wire, thereby improving the stability and quality of underwater welding.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater welding, and in particular relates to an ultrasonic-assisted underwater arc welding device and method. Background Art

[0002] The development of marine resources, the construction of cross-sea transportation facilities, ships and marine equipment, and national defense construction have greatly accelerated the demand for offshore engineering structures / marine engineering structures, and welding on-site underwater has become a general trend. Compared with underwater welding processes such as dry welding, which require the construction of drainage facilities to seal the welding area, underwater wet welding directly strikes the arc underwater, using the heating of the welding wire core components to generate gas and the gasification of water to form dynamic bubbles that cover the arc and maintain arc burning. This process has significant cost and adaptability advantages, and has relatively the best application prospects in the context of large-scale applications.

[0003] However, in this welding process, the welding wire and the workpiece are directly placed in water, and the arc burning and the transition of the filler material to the weld (molten droplet transition) are mainly formed by the continuous thermal decomposition, evaporation or reaction of the flux core gasifier and water. Affected by the unstable existence and constantly changing morphology of the bubbles, the conductive position, voltage and current of the arc are unstable, and there is frequent arc extinction. When the bubbles float up, necking may occur, and then the floating gas and the newly generated gas group below are separated and continue to float up, leaving a smaller new bubble covering the arc and the molten droplet. The necking and separation process may lead to the unstable existence of the arc. Due to the influence of airflow and other resistances, the molten droplets are transferred in the form of large droplet repulsion or irregular short-circuit transition. The molten droplet size is large and the frequency is low. The falling trajectory presents a random and non-axial shape, resulting in unstable droplet transition, a lot of spatter, and asymmetric and uneven welds. The microstructure and properties of the weld and heat-affected zone deviate from expectations, affecting the welding quality.

[0004] The molten droplets in underwater wet welding are mainly repelled by the drag force of the gas in the bubble and the arc force, which makes it difficult for them to fall freely, and they are forced to grow to a larger size or even repelled from the axis of the welding wire. Patent No. CN202310120306.X discloses an ultrasonic-assisted underwater laser-FCAW composite wet welding device, which uses the ultrasonic radiation force generated by the ultrasonic auxiliary mechanism to act on the bubbles on the surface of the welding workpiece, delay the bubble floating time, reduce the bubble floating frequency, and at the same time weaken the repulsive effect of the bubble buoyancy on the molten droplet transition, thereby improving the quality of the welded joint. However, when ultrasonic vibration propagates across the medium, if the acoustic properties (acoustic impedance or sound velocity) of the media on both sides of the interface differ too much, most of the ultrasound will be reflected (ultrasonic propagation formula), so the above technology only propagates ultrasound in the water body, and can only indirectly regulate the arc and molten droplets in the bubble, and cannot achieve direct regulation of the molten droplets. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned technologies, the present invention provides an ultrasonic-assisted underwater arc welding device and method, which couples ultrasonic vibration to the welding wire for the first time, propagates ultrasonic vibration and energy with the help of the welding wire, and makes the ultrasound cross the gas-water heterogeneous interface based on solid-state conduction, directly acts on the inside of the bubble of underwater wet welding, and directly regulates the arc and the droplet. Compared with the prior art that acts on the bubble with ultrasound, the stability of the arc and the droplet transition is indirectly improved. The ultrasonic vibration of the present invention directly passes through the bubble through the welding wire to act on the arc and the droplet, so as to directly regulate the stability of the arc and the posture of the droplet, the welding stability is higher, the weld is more uniform and consistent, there are fewer defects, and the underwater welding quality is improved.

[0006] The present invention is achieved through the following technical solutions:

[0007] An ultrasonic-assisted underwater arc welding device comprises a welding gun, a coupler and an ultrasonic-assisted device. The welding gun comprises a first barrel, a second barrel and a connecting piece, a conductive nozzle is installed at the end of the second barrel, and the connecting piece is fixed between the first barrel and the second barrel to conduct the current of the first barrel to the second barrel. The coupler is an insulator and connects the first barrel and the second barrel, and the welding wire extends from the conductive nozzle to the welding point after passing through the first barrel, the coupler and the second barrel. The ultrasonic-assisted device passes through the coupler and abuts against the welding wire, and directly controls the arc and the molten droplet by vibrating the welding wire, thereby improving the stability and quality of underwater welding.

[0008] Furthermore, a wire feeding mechanism is provided at the head end of the first gun barrel, and the wire feeding mechanism provides power for the welding wire to move in the welding gun, and the moving path of the welding wire in the welding gun is straight or curved;

[0009] When the moving path of the welding wire in the welding gun is in a curved shape, the first barrel, the second barrel and / or the coupler are in a curved shape, and the ultrasonic auxiliary device is arranged tangent to the welding wire to provide ultrasonic vibration of the welding wire in the axial direction of the welding wire. During the welding operation, the end of the welding wire points to the molten droplet, that is, the vibration direction of the end of the welding wire points to the molten droplet, so that the ultrasonic vibration effect of the welding wire on the molten droplet can be maximized, thereby improving the control ability of the ultrasonic vibration on the molten droplet.

[0010] Furthermore, a bubble cover is installed on the periphery of the second gun barrel, and the bubble cover is concavely arranged toward the conductive nozzle to slow down the rising speed of the bubble, weaken the repulsive effect of the bubble buoyancy on the molten droplet transition, and slow down the arc instability caused by necking during bubble rising, thereby improving the quality of the welding weld.

[0011] Furthermore, a second ultrasonic auxiliary device is installed on one side of the welding gun, and the ultrasonic vibration generated by the second ultrasonic auxiliary device acts on the bubbles on the surface of the welding workpiece to delay the time for the bubbles to float up. During the welding process, the ultrasonic radiation force generated by the second ultrasonic auxiliary device acts on the bubbles on the surface of the welding workpiece, delaying the time for the bubbles to float up, reducing the frequency of the bubbles to float up, and at the same time weakening the repulsive effect of the bubble buoyancy on the droplet transfer, slowing down the arc instability caused by the necking during the bubble floating period, thereby improving the quality of the welding weld.

[0012] Furthermore, waterproof shells are provided on the outer sides of the ultrasonic auxiliary device and the second ultrasonic auxiliary device to achieve deep water welding at a depth of 20m-100m.

[0013] Further, the welding parameters of the welding gun are: welding arc voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, welding wire diameter: 1mm-2mm, wire feeding speed 2.5m / min-8.5m / min;

[0014] The welding parameters of the ultrasonic assisted device are: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W, ultrasonic amplitude: 2μm-5μm;

[0015] The operating environment of the welding gun is: water depth 0-100m, water flow speed 0-1m / .

[0016] Furthermore, a mounting hole is provided on the coupler, the ultrasonic auxiliary device passes through the mounting hole and abuts against the welding wire, a sealing sleeve is provided outside the mounting hole, and the sealing sleeve is sealed and connected to the outer wall of the ultrasonic auxiliary device to prevent water from entering the coupler through the gap between the ultrasonic auxiliary device and the mounting hole of the coupler.

[0017] An ultrasonic assisted underwater arc welding method comprises the following steps:

[0018] Step 1: Install the ultrasonic auxiliary device, and pass the ultrasonic auxiliary device through the coupler to abut against the welding wire;

[0019] Step 2: Adjust the distance between the welding gun and the welding workpiece so that the vertical distance between the conductive nozzle and the welding workpiece is in the range of 10mm-35mm;

[0020] Step 3: Start the ultrasonic auxiliary device, and adjust the welding parameters of the ultrasonic auxiliary device as follows: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W, ultrasonic amplitude: 2μm-5μm;

[0021] Step 4: After the ultrasonic auxiliary device works stably, turn on the welding power supply and adjust the welding parameters of the welding gun as follows: welding arc voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, wire feeding speed 2.5m / min-8.5m / min;

[0022] Step 5: After welding is completed, turn off the welding power supply and ultrasonic auxiliary device in sequence.

[0023] Furthermore, step 1 also includes: installing a second ultrasonic auxiliary device on one side of the welding gun;

[0024] Step 2 also includes: adjusting the position of the second ultrasonic auxiliary device, turning on the welding power supply, placing the second ultrasonic auxiliary device against the bubble generated by welding, turning off the welding power supply, and completing the position adjustment of the second ultrasonic auxiliary device.

[0025] Furthermore, in step 1, the ultrasonic auxiliary device passes through the mounting hole of the coupler, and then a sealing sleeve is used to seal the gap between the ultrasonic auxiliary device and the mounting hole.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention assembles an ultrasonic vibration device and a welding gun to achieve ultrasonic vibration coupling into the welding wire, uses the welding wire to propagate ultrasound and serve as an acoustic emission end, and realizes a compact integrated ultrasonic-assisted underwater wet welding device. The welding gun has good accessibility and is suitable for various joint forms and welding structures;

[0028] 2. The ultrasonic auxiliary device is directly in contact with the welding wire. The welding wire passes through the bubble at the welding point and acts on the arc and molten droplets in the bubble, realizing for the first time the direct regulation of the molten droplets and arc plasma in the bubble by ultrasound. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A connection diagram for illustrating an exemplary embodiment of an ultrasonic-assisted underwater arc welding device in the present invention;

[0030] Figure 2 A schematic structural diagram for illustrating an exemplary embodiment of an ultrasonic-assisted underwater arc welding device in the present invention;

[0031] Figure 3 A connection diagram for illustrating another exemplary embodiment of an ultrasonic-assisted underwater arc welding device in the present invention;

[0032] Figure 4 A schematic structural diagram for illustrating another exemplary embodiment of an ultrasonic-assisted underwater arc welding device in the present invention;

[0033] Figure 5 A front view for illustrating a schematic embodiment of an ultrasonic-assisted underwater arc welding device according to the present invention;

[0034] Figure 6 To illustrate Figure 5 A partial enlarged schematic diagram in the middle.

[0035] List of parts and reference numerals:

[0036] 1. Welding gun; 11. First barrel; 12. Second barrel; 13. Connecting vessel; 14. Bubble cover; 2. Coupler; 21. Sealing sleeve; 3. Ultrasonic auxiliary device; 4. Conductive nozzle; 5. Second ultrasonic auxiliary device; 6. Welding wire; 7. Molten drop; 8. Bubble; 9. Welding workpiece; 10. Electric arc. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that the directional terms such as left, right, up, down, front and back in the embodiments of the present invention are merely relative concepts or are based on the normal use state of the product, that is, the direction of movement of the product, and should not be considered as limiting.

[0039] In addition, it should be noted that the dynamic terms such as "relative motion" mentioned in the embodiments of the present invention refer not only to changes in position, but also to movements such as rotation and rolling in which there is no relative change in position but a change in state.

[0040] Finally, it should be noted that when a component is referred to as being "located" or "set on" another component, it can be on the other component or there can be an intermediate component at the same time. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or there can be an intermediate component at the same time.

[0041] Current problems with underwater wet welding: The welding process is unstable due to the cooling, low viscosity, and good fluidity of water. During the welding process, the shape of the bubbles 8 is uncertain and changes at a high speed, which can easily cause the arc 10 to be extinguished by water. The molten droplets 7 are difficult to transition normally due to the air flow resistance, forming irregular molten droplets 7 that are much larger than those in land welding, or falling in unexpected directions, and even forming splashes. The above characteristics can lead to a significant deterioration in weld formation, thereby affecting joint performance.

[0042] What you need to know is:

[0043] 1. Effect of ultrasound on arc 10 during underwater (wet) welding:

[0044] a. Improvement of bubble stability indirectly improves arc 10 stability Mechanism: Underwater wet welding relies on bubbles 8 to isolate arc 10 from water to continue welding. The bursting of bubbles 8 during underwater wet welding will cause arc 10 to extinguish. Applying ultrasound to bubbles 8 will improve the stability of bubbles 8, thereby indirectly improving the stability of arc 10 and reducing the arc extinguishing rate.

[0045] b. The restraining effect of ultrasound on the arc 10 when it acts directly on the arc 10: If ultrasound can be directly transmitted and act on the arc 10, as has been proven in terrestrial welding technology, or if ultrasound is directly transmitted into the bubble 8 through the welding wire through the present technology, the density of the arc 10 plasma can be increased, and the current density of the arc 10 can be increased, so that the heat generated by the arc 10 is relatively concentrated, the stability of the arc 10 is increased, and the gasification ability of the core components and the water body is enhanced, that is, the arc 10 is not easy to extinguish, and the conductive position of the arc 10 is more stable.

[0046] 2. Effect of underwater (wet) welding ultrasound on molten droplet 7:

[0047] Changing the magnitude of the force acting on the droplet 7 will affect the transition mechanism of the droplet 7:

[0048] a. Reduce the surface tension of the molten drop 7 (indirectly): The volume of the arc 10 airbag (bubble 8) is affected to change the magnitude of the force acting on the molten drop 7, thereby affecting the transition of the molten drop 7. Specifically, the acoustic radiation force compresses the bubble 8, and the rise is slow, the heat taken away by the bubble 8 is reduced, the molten drop 7 is overheated, the surface temperature of the molten drop 7 rises slightly, and the surface tension of the molten drop 7 is reduced. The surface tension is the force that inhibits the transition of the molten drop 7, so when the surface tension is reduced, the transition of the molten drop 7 becomes easier, the short-circuit transition ratio of the molten drop 7 is reduced, and the transition of the molten drop 7 is more stable.

[0049] b. Reduce the drag force of the bubble 8 on the molten drop 7 (indirectly): The gas drag force generated by the dynamic floating of the bubble 8 on the molten drop 7 and the buoyancy generated by the bubble 8 itself will hinder the transition of the molten drop 7. Under the action of ultrasound, the motion state of the bubble 8 changes, and its hindering effect on the transition of the molten drop 7 is weakened. Therefore, the molten drop 7 can easily transition freely from the arc 10 space, making it easier to form a drop-shaped repulsive transition process, and the short-circuit process is not easy to occur, so the short-circuit ratio is reduced.

[0050] c. The above two types of effects a. and b. mainly indirectly affect the molten droplet 7 by means of complex changes in the behavior of the bubble 8, and the significance and stability of the effect are limited. If ultrasound can be directly transmitted and acted on the arc 10, as has been proven in welding technology on land, or if ultrasound is directly transmitted into the bubble 8 through the welding wire through this technology, the acoustic radiation force in the ultrasonic field can be used as a promoting force for the molten droplet to separate from the welding wire at a suitable distance, thereby increasing the transition frequency, reducing the molten droplets that are too large or short-circuited, and improving the quality of weld formation. This effect directly applies force to the molten droplet 7, and the effect is more controllable and stable.

[0051] Usually the reflected wave sound pressure P r The incident wave sound pressure P The ratio of 0 is called the sound pressure reflectivity r , the transmitted wave sound pressure P t and P The ratio of 0 is called sound pressure transmittance t When the ultrasonic wave is incident vertically on the interface, r and t The mathematical expression is:

[0052]

[0053]

[0054] Where: Z 1 is the acoustic impedance of the first medium; Z 2 is the acoustic impedance of the second medium.

[0055] In order to study the energy relationship between reflected waves and transmitted waves, the acoustic intensity reflectivity is introduced. R Sound intensity transmittance T Two quantities. R is the reflected wave intensity ( I r ) and the incident wave intensity ( I 0) ratio; T is the transmitted wave intensity ( I t ) and the incident wave intensity ( I 0).

[0056]

[0057]

[0058] It can be seen from the above formula that when the acoustic impedance of the media on both sides of the interface differs too much, most of the vertically incident ultrasonic energy will be reflected, and the transmitted sound intensity will be extremely low. If factors such as waveform conversion and critical angle at oblique incidence are considered, the transmitted sound intensity will be even lower.

[0059] The acoustic impedance of water at room temperature is 1.48×10 6 kg / (m 2 ·s), while the acoustic impedance of air is only 4×10 2 kg / (m 2 ·s), a difference of more than 3000 times. When sound waves are incident on the interface between water and air, only less than 0.1% of the sound energy can pass through the water-air interface.

[0060] Although the arc 10 bubble 8 is rich in H and other elements, which is different from the composition of air, its acoustic impedance is still much smaller than that of water. When the ultrasonic transmitter is located in water, most of the ultrasonic energy cannot enter the bubble 8.

[0061] In the background technology, the prior art changes the magnitude of the force on the molten droplet 7 by applying ultrasonic vibration to the air bubble 8 in the water body, thereby affecting the transition mechanism of the molten droplet 7, and indirectly controls the shape of the molten droplet 7 by regulating the motion posture of the air bubble 8. However, when the ultrasonic vibration enters the air bubble 8 from the water body, that is, when the sound wave crosses the water-air interface, only less than 0.3% of the sound energy can directly act on the molten droplet 7, and this sound energy is far from achieving the effect of directly regulating the molten droplet 7 and the arc 10. Therefore, the prior art can only regulate the posture of the air bubble 8 through ultrasonic vibration, thereby indirectly changing the behavior of the molten droplet 7 and the arc 10, and cannot directly regulate the molten droplet 7 and the arc 10.

[0062] Among them, it should be emphasized that, since the volume of the bubble 8 itself is relatively small, and the arc 10 in the bubble 8 will occupy most of the volume of the bubble 8, the temperature of the arc 10 can reach tens of thousands of K (degrees Kelvin), and the ultrasonic auxiliary device 3 cannot directly pass through the bubble 8 to act on the molten drop 7 and the arc 10. Therefore, the existing ultrasonic auxiliary device 3 can only act in the water body near the bubble 8 to play a role in regulating the bubble 8. If the tip of the ultrasonic auxiliary device 3 is extended through the bubble 8 into the vicinity of the molten drop 7, the tip of the ultrasonic auxiliary device 3 will be quickly destroyed by the arc 10. Therefore, the present invention realizes direct regulation of the molten drop 7 and the arc 10 inside the bubble 8 by applying the ultrasonic auxiliary device 3 to the welding wire 6 and using the welding wire 6 to conduct ultrasound to the inside of the bubble 8.

[0063] like Figures 1 to 6The ultrasonic assisted underwater arc 10 welding device shown in the figure comprises a welding gun 1, a coupler 2 and an ultrasonic assisted device 3. The welding gun 1 comprises a first barrel 11, a second barrel 12 and a connecting piece 13, a conductive nozzle 4 is installed at the end of the second barrel 12, and the connecting piece 13 is fixed between the first barrel 11 and the second barrel 12 to conduct the current of the first barrel 11 to the second barrel 12. The coupler 2 is an insulator and connects the first barrel 11 and the second barrel 12. The welding wire 6 passes through the first barrel 11, the coupler 2 and the second barrel 12 and then extends from the conductive nozzle 4 to the welding point. The ultrasonic assisted device 3 passes through the coupler 2 and abuts against the welding wire 6, so as to vibrate the welding wire 6 to realize direct regulation of the molten droplet 7 and the arc 10, thereby improving the stability and quality of underwater welding.

[0064] In one embodiment, when the present invention is used for welding, the ultrasonic auxiliary device 3 passes through the coupler 2 and abuts against the welding wire 6 to transfer ultrasonic energy to the welding wire 6. When welding the workpiece, the tip of the welding wire 6 is located inside the bubble 8, and the tip of the welding wire 6 vibrates to transfer ultrasonic energy to the molten droplet 7, thereby directly regulating the state of the arc 10 and the molten droplet 7. The frequency of the ultrasonic auxiliary device 3 and the distance between the welding wire tip and the ultrasonic auxiliary device are adjusted (by replacing the second barrel 12 of different sizes and adjusting the dry extension length of the welding wire), so that the molten droplet 7 can smoothly transition under the action of ultrasonic energy, the arc 10 is more stable, and it is less likely to extinguish, so that the welding state is smoother and smoother.

[0065] The welding wire 6 extending out of the conductive nozzle 4 carries relatively high ultrasonic energy, so that the welding wire 6 also has the effect of suppressing the bubbles 8 from floating up, thereby slowing down the floating speed of the bubbles 8 .

[0066] Preferably, a wire feeding mechanism is further provided at the head end of the first gun barrel 11, and the wire feeding mechanism provides power for the welding wire 6 to move in the welding gun 1, and the moving path of the welding wire 6 in the welding gun is straight or curved;

[0067] When the moving path of the welding wire 6 in the welding gun 1 is in a curved shape, the first barrel 11, the second barrel 12 and / or the coupler 2 are in a curved shape, and the ultrasonic auxiliary device 3 is arranged tangent to the welding wire 6 to provide ultrasonic vibration of the welding wire 6 in the axial direction of the welding wire 6. During the welding operation, the end of the welding wire 6 points to the arc 10 and the molten droplet 7, that is, the vibration direction of the end of the welding wire points to the molten droplet 7, so that the ultrasonic vibration effect of the welding wire on the molten droplet can be maximized, and the control ability of the ultrasonic vibration on the arc 10 and the molten droplet 7 is improved.

[0068] In one embodiment, a welding cable is further connected between the first gun barrel and the wire feeding mechanism, and the wire feeding mechanism feeds the welding wire to the first gun barrel through the welding cable.

[0069] In one embodiment, if Figure 3 and Figure 4As shown, the coupler 2 is arranged in a curved shape, and the ultrasonic auxiliary device 3 is arranged tangent to the welding wire 6, so that the ultrasonic auxiliary device 3 transmits ultrasonic vibrations along the extension direction of the welding wire 6 to the welding wire 6, thereby making the vibration direction of the tip of the welding wire 6 point to the molten droplet 7 at the weld.

[0070] In one embodiment, the ultrasonic auxiliary device 3 includes an ultrasonic transducer, and the position where the ultrasonic auxiliary device 3 is coupled to the welding wire 6 is within 20m from the tip of the welding wire 6. At this time, it is necessary to ensure that the output power of the ultrasonic transducer is not less than 25W per meter. When the depth of deep water welding reaches more than 20m, a waterproof shell needs to be installed on the outside of the ultrasonic auxiliary device 3.

[0071] In one embodiment, the first gun barrel 11 is mounted on a wire feeder, which is also provided with a wire feeding pipeline, and the wire feeding pipeline is provided with an opening, and the ultrasonic auxiliary device 3 passes through the opening and abuts against the welding wire 6. The ultrasonic auxiliary device 3 is implemented to regulate the wire feeding behavior behind the wire feeding mechanism.

[0072] Preferably, a bubble cover 14 is installed on the periphery of the second barrel 12, and the bubble cover 14 is recessed toward the conductive nozzle 4 to slow down the rising speed of the bubble 8, reduce the obstruction of the rising airflow of the bubble 8 on the transition of the molten droplet 7, and slow down the adverse effect on the stability of the arc 10 caused by the shrinkage of the bubble 8 and the separation into new and old bubbles, thereby improving the quality of the welding weld.

[0073] In one embodiment, the bubble cover 14 is slidably connected to the second barrel 12, and a locking member is provided between the bubble cover 14 and the second barrel 12. By adjusting the position of the bubble cover 14 relative to the second barrel 12, the distance between the bubble cover 14 and the tip of the welding wire 6 is adjusted to suppress the floating of the bubble 8 and slow down the floating speed of the bubble 8 while ensuring normal welding.

[0074] Preferably, a second ultrasonic auxiliary device 5 is installed on one side of the welding gun 1, and the ultrasonic vibration generated by the second ultrasonic auxiliary device 5 acts on the bubbles 8 on the surface of the welding workpiece 9 to delay the floating time of the bubbles 8. During the welding process, the ultrasonic radiation force generated by the second ultrasonic auxiliary device 5 acts on the bubbles 8 on the surface of the welding workpiece 9, delaying the floating time of the bubbles 8, reducing the floating frequency of the bubbles 8, and at the same time weakening the repulsive effect of the buoyancy of the bubbles 8 on the transition of the molten droplets 7, and slowing down the adverse effects on the stability of the arc 10 caused by the necking and separation of the bubbles 8, thereby improving the quality of the welding weld.

[0075] In one embodiment, in order to further improve the welding quality, a second ultrasonic auxiliary device 5 is also installed on one side of the welding gun 1. The ultrasonic vibration of the second ultrasonic auxiliary device 5 acts on the water near the bubble 8. The ultrasonic radiation force generated by the ultrasonic vibration acts on the bubble 8 above the welding workpiece 9, delaying the time for the bubble 8 to float up. At the same time, the ultrasonic action reduces the floating frequency of the bubble 8, weakens the disturbance of the bubble 8, and causes the arc 10 to fluctuate less, thereby improving the stability of the arc 10. In addition, the repulsive effect of the buoyancy of the bubble 8 on the transition of the molten droplet 7 is weakened, so that the molten droplet 7 transitions in a smooth manner, which is conducive to improving the stability of the welding process. In addition, the acoustic streaming effect generated by the ultrasonic vibration can form a stable beam flow in the water around the welding workpiece 9, which can effectively reduce the influence of the water flow disturbance at the welding workpiece 9 on the welding quality.

[0076] It should be noted that the ultrasonic auxiliary device 3 and the second ultrasonic auxiliary device 5 are both existing structures, and the principle of ultrasound generation and the like will not be described in detail.

[0077] Preferably, the outer sides of the ultrasonic auxiliary device 3 and the second ultrasonic auxiliary device 5 are both provided with waterproof shells to achieve deep water welding at a depth of 20m-100m.

[0078] Preferably, the welding parameters of the welding gun 1 are: welding arc 10 voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, welding wire 6 diameter: 1mm-2mm, wire feeding speed 2.5m / min-8.5m / min;

[0079] The welding parameters of the ultrasonic auxiliary device 3 are: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W, ultrasonic amplitude: 2μm-5μm;

[0080] The use environment of the welding gun 1 is: water depth 0-100m, water flow speed 0-1m / .

[0081] Preferably, a mounting hole is opened on the coupler 2, the ultrasonic auxiliary device 3 passes through the mounting hole and abuts against the welding wire 6, a sealing sleeve 21 is provided outside the mounting hole, and the sealing sleeve 21 is sealed and connected to the outer wall of the ultrasonic auxiliary device 3 to prevent water from entering the coupler 2 through the gap between the ultrasonic auxiliary device 3 and the mounting hole of the coupler 2.

[0082] In one embodiment, if Figure 5 As shown, a sealing sleeve 21 is provided between the mounting hole and the ultrasonic auxiliary device 3, one end of the sealing sleeve 21 is wrapped to the outside of the ultrasonic auxiliary device 3 and is sealed with the ultrasonic auxiliary device 3, and the other end of the sealing sleeve 21 is connected to the periphery of the mounting hole and is sealed with the mounting hole. The sealing sleeve 21 is made of waterproof cloth, and the sealing sleeve 21 itself is elastic to reduce the influence of the vibration of the ultrasonic auxiliary device 3 on the housing of the coupler 2.

[0083] It should be noted that the sealing sleeve 21 may not be provided between the mounting hole and the ultrasonic auxiliary device 3. When the sealing sleeve 21 is provided between the mounting hole and the ultrasonic auxiliary device 3, an ultrasonic coupling agent needs to be injected into the coupler 2; when the sealing sleeve 21 is not provided between the mounting hole and the ultrasonic auxiliary device 3, water can be used as an ultrasonic coupling agent.

[0084] An ultrasonic assisted underwater arc welding method comprises the following steps:

[0085] Step 1: Install the ultrasonic auxiliary device 3, and pass the ultrasonic auxiliary device 3 through the coupler 2 to abut against the welding wire 6;

[0086] Step 2: Adjust the distance between the welding gun 1 and the welding workpiece 9 so that the vertical distance between the conductive tip 4 and the welding workpiece 9 is in the range of 10 mm to 35 mm;

[0087] Step 3: Start the ultrasonic auxiliary device 3, and adjust the welding parameters of the ultrasonic auxiliary device 3 to: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W, ultrasonic amplitude: 2μm-5μm;

[0088] Step 4: After the ultrasonic auxiliary device 3 works stably, turn on the welding power supply and adjust the welding parameters of the welding gun 1 as follows: welding arc 10 voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, wire feeding speed 2.5m / min-8.5m / min;

[0089] Step 5: After welding is completed, turn off the welding power supply and the ultrasonic auxiliary device 3 in sequence.

[0090] Preferably, step 1 further includes: installing a second ultrasonic auxiliary device 5 on one side of the welding gun 1;

[0091] Step 2 also includes: adjusting the position of the second ultrasonic auxiliary device 5, turning on the welding power supply, moving the second ultrasonic auxiliary device 5 close to the bubble 8 generated by welding, turning off the welding power supply, and completing the position adjustment of the second ultrasonic auxiliary device 5.

[0092] Preferably, in step 1, the ultrasonic auxiliary device 3 passes through the mounting hole of the coupler 2, and then the sealing sleeve 21 is used to seal the gap between the ultrasonic auxiliary device 3 and the mounting hole.

[0093] When the above-mentioned ultrasonic-assisted underwater arc 10 welding device is used, ultrasonic vibration and energy are transmitted by means of the welding wire 6, and the ultrasound is made to cross the gas-water heterogeneous interface based on solid-state conduction, directly acting on the inside of the bubble 8 of underwater wet welding, and regulating the arc 10 and the molten droplet 7. Compared with the prior art in which ultrasound is applied to the bubble 8, the stability of the transition between the arc 10 and the molten droplet 7 is indirectly improved. The ultrasonic vibration of the present invention directly passes through the bubble 8 through the welding wire 6 to act on the droplet or arc, so as to directly regulate the posture of the droplet, the welding stability is higher, the weld is more flush, and the underwater welding quality is improved.

[0094] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An ultrasonically assisted underwater arc welding device, characterized in that: include: A welding gun, the welding gun comprising a first barrel, a second barrel and a connecting piece, a conductive nozzle is installed at the end of the second barrel, and the connecting piece is fixed between the first barrel and the second barrel to conduct the current of the first barrel to the second barrel; A coupler, the coupler is an insulator and is connected to the first barrel and the second barrel, the welding wire passes through the first barrel, the coupler and the second barrel and then extends from the conductive nozzle to the welding point, and an ultrasonic coupling agent is injected into the coupler; An ultrasonic auxiliary device, which passes through the coupler and abuts against the welding wire to vibrate the welding wire to achieve direct regulation of the arc and the molten droplet; A wire feeding mechanism is also provided at the head end of the first gun barrel, and the wire feeding mechanism provides power for the welding wire to move in the welding gun, and the moving path of the welding wire in the welding gun is linear or curved; When the moving path of the welding wire in the welding gun is curved, the first gun barrel, the second gun barrel and / or the coupler are curved, and the ultrasonic auxiliary device is arranged tangentially to the welding wire to provide ultrasonic vibration of the welding wire in the axial direction of the welding wire; The coupler is provided with a mounting hole, the ultrasonic auxiliary device passes through the mounting hole and abuts against the welding wire, a sealing sleeve is provided outside the mounting hole, and the sealing sleeve is sealed and connected to the outer wall of the ultrasonic auxiliary device.

2. The ultrasonic-assisted underwater arc welding device according to claim 1, characterized in that: A bubble cover is installed on the periphery of the second gun barrel, and the bubble cover is concavely arranged toward the conductive nozzle.

3. The ultrasonic-assisted underwater arc welding device according to claim 1, characterized in that: A second ultrasonic auxiliary device is installed on one side of the welding gun. The ultrasonic vibration generated by the second ultrasonic auxiliary device acts on the bubbles on the surface of the welding workpiece to delay the floating time of the bubbles.

4. The ultrasonic-assisted underwater arc welding device according to claim 3, characterized in that: The outer sides of the ultrasonic auxiliary device and the second ultrasonic auxiliary device are both provided with a waterproof shell.

5. The ultrasonic-assisted underwater arc welding device according to claim 1, characterized in that: The welding parameters of the welding gun are: welding arc voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, welding wire diameter: 1mm-2mm, wire feeding speed 2.5m / min-8.5m / min; The welding parameters of the ultrasonic assisted device are: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W; The use environment of the welding gun is: water depth 0-100m.

6. An ultrasonically assisted underwater arc welding method, applied to the ultrasonically assisted underwater arc welding device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Install the ultrasonic auxiliary device, and pass the ultrasonic auxiliary device through the coupler to abut against the welding wire; Step 2: Adjust the distance between the welding gun and the welding workpiece so that the vertical distance between the conductive nozzle and the welding workpiece is in the range of 10mm-35mm; Step 3: Start the ultrasonic auxiliary device, and adjust the welding parameters of the ultrasonic auxiliary device to: ultrasonic frequency: 15kHz-60kHz, ultrasonic power: 100W-600W; Step 4: After the ultrasonic auxiliary device works stably, turn on the welding power supply, and adjust the welding parameters of the welding gun as follows: welding arc voltage: 20V-40V, welding current: 180A-400A, welding speed: 2mm / s-7mm / s, wire feeding speed 2.5m / min-8.5m / min; Step 5: After welding is completed, turn off the welding power supply and ultrasonic auxiliary device in sequence.

7. The ultrasonic-assisted underwater arc welding method according to claim 6, characterized in that: The step 1 also includes: installing a second ultrasonic auxiliary device on one side of the welding gun; The step 2 also includes: adjusting the position of the second ultrasonic auxiliary device, turning on the welding power supply, placing the second ultrasonic auxiliary device against the bubble generated by welding, turning off the welding power supply, and completing the position adjustment of the second ultrasonic auxiliary device.

8. The ultrasonic-assisted underwater arc welding method according to claim 6, characterized in that: In step 1, the ultrasonic auxiliary device passes through the mounting hole of the coupler, and then a sealing sleeve is used to seal the gap between the ultrasonic auxiliary device and the mounting hole.

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