A transformer oil tank welding apparatus

Abstract

The application relates to the technical field of welding equipment, and discloses a transformer oil tank welding equipment which comprises a connecting assembly, a welding head and a welding wire. An axially movable sliding seat is arranged in the welding head, a plurality of clamping petals are arranged at the front end of the sliding seat, and the limiting rods outside the clamping petals are matched with the guide cone surfaces in the limiting rings. The clamping petals are folded and contacted with the welding wire when the welding wire is normally fed; when the welding wire is burnt back and fused and adhered with the clamping petals, the subsequent wire feeding thrust drives the sliding seat to move forward through the clamping petals, the clamping petals are released from the radial constraint along the guide cone surfaces and are unfolded outward, and the sliding seat is driven to reset by the elastic element after the welding wire is separated. The connecting rod conveys the protective gas into the protective sleeve, and the gas gap between the clamping petals is synchronously increased when the clamping petals are unfolded, so that the gas more directly flows to the front end of the welding wire. The application can complete mechanical wire release and automatic reset when abnormal adhesion occurs, and can maintain the protective gas coverage of the welding area.

Description

Technical Field

[0001] This application relates to the field of welding equipment technology, specifically to a transformer oil tank welding device. Background Technology

[0002] Transformer tanks are formed by welding multiple metal plates and connecting components. During production, assembly and local spot welding are typically completed first, followed by continuous welding of the joints using gas-shielded welding. To ensure consistency in weld trajectory and welding cycle time, production lines often employ robotic arms to move the welding torch. The welding wire is continuously fed into the torch tip by a wire feeding mechanism and receives welding current through conductive contact components. When continuous welding is required for extended periods, the stability of the wire feeding at the torch tip directly affects whether the tank welding process can proceed continuously. Existing gas-shielded welding torches typically have conductive contact components and shielding gas channels around the welding wire. The conductive contact components transfer the welding current to the welding wire and constrain its feed position, while the shielding gas is delivered to the welding wire tip through internal channels within the torch to provide gas protection for the welding area.

[0003] Chinese invention patent document CN104959715B discloses a conductive tip for arc welding, which includes a conductive tip body and a limiting plate. The conductive tip body has a diamond-shaped through hole for guiding the welding wire, and the limiting plate has a flower-shaped through hole corresponding to the position of the diamond-shaped through hole. The hole shape fits together to maintain multi-point contact between the welding wire and the conductive tip, thereby improving the problem of poor contact between the welding wire and the conductive tip. This solution mainly focuses on improving the guidance of the welding wire and the stability of conductive contact. The conductive tip body is still a fixed wire guide and conductive structure. When the end of the welding wire becomes fused and adhered to the conductive contact position due to abnormal burn-back, it does not have a structure that can use the subsequent wire feeding thrust to displace the conductive contact component and actively release the welding wire.

[0004] During continuous wire feeding, when local welding gaps, tack welded positions, or momentary arc conditions change, a temporary mismatch may occur between wire feeding and melting. This causes the wire tip to burn back into the welding torch and fuse with the conductive contact component at the front end. Fixed conductive contact structures cannot actively release the wire with the wire feeding action after this occurs; continued wire feeding can easily lead to wire jamming, bending, or welding stoppage. Simultaneously, abnormalities in the position and opening of the conductive contact structure will also alter the shielding gas flow space at the front end of the welding torch. Therefore, a transformer tank welding device is needed that can directly utilize the remaining wire feeding thrust under abnormal conditions to release the wire and synchronously adjust the shielding gas flow path at the front end with the release action. Summary of the Invention

[0005] This application provides a transformer tank welding device, which aims to solve the problem that after the welding wire burns back and fuses with the conductive contact component at the front end of the welding torch during continuous welding, the fixed contact structure cannot release the welding wire with the wire feeding action, which easily leads to the interruption of wire feeding, while also taking into account the flow of protective gas at the front end of the welding torch during the wire release state.

[0006] This application discloses a transformer tank welding device, comprising a connecting assembly, a welding head connected to the connecting assembly, and a welding wire threaded within the welding head. The welding head includes a protective sleeve, a connecting rod disposed within the protective sleeve, a sliding seat slidably disposed within the connecting rod, an elastic element connecting the sliding seat and the connecting rod, multiple clamping petals connected to the front end of the sliding seat and distributed around the welding wire, and a limiting ring disposed on the outer periphery of the clamping petals. A limiting rod is provided on the outer side of the clamping petal, and a guide cone surface with a gradually expanding diameter along the welding wire feeding direction is provided on the inner side of the limiting ring. When the clamping petal is constrained by the limiting ring, it retracts and contacts the welding wire. When the welding wire is fused and adhered to the clamping petal and continues to be pushed by the wire feeding force, the welding wire drives the sliding seat forward through the clamping petal, causing the limiting rod to move along the guide cone surface towards the larger diameter side and causing the clamping petal to unfold outward. The elastic element drives the sliding seat to reset after the welding wire is disengaged. The connecting rod is provided with an vent hole communicating with the interior of the protective sleeve, and an vent gap is formed between adjacent clamping petals that increases as the clamping petals unfold.

[0007] Its effect is as follows: During normal operation, the limiting ring restricts the radial position of the clamping petals through the limiting rod, keeping the multiple clamping petals closed and in sliding contact with the welding wire. After fusion adhesion occurs, the original wire feeding force no longer only pushes the welding wire relative to the clamping petals, but is transmitted through the adhesion position to the clamping petals and the sliding seat, causing the sliding seat to move forward along the connecting rod. After the limiting rod moves with the sliding seat towards the large diameter side of the guide cone, the radial constraint on the clamping petals decreases and unfolds outward, the space through which the welding wire passes expands accordingly, and the fusion position is released by radial separation. After the welding wire resumes feeding, the elastic element drives the sliding seat and clamping petals to reset; during the unfolding of the clamping petals, the gas outlet gap between the petals increases synchronously, allowing the shielding gas to form an additional flow path toward the front end of the clamping petals and around the welding wire.

[0008] Preferably, the connecting assembly includes a connecting plate and an insulating sleeve. The connecting plate has multiple connecting holes spaced apart circumferentially and is detachably connected to the end of the robotic arm through the connecting holes. The insulating sleeve is located on the side of the connecting plate near the welding head and is fitted around the outer periphery of the welding head.

[0009] Its effects are as follows: the connecting plate provides a stable installation interface for the welding head and the robotic arm, and the multiple connecting holes facilitate the determination of the installation position; the insulating sleeve separates the conductive part of the welding head from the connection part of the robotic arm, so that the welding head can move with the robotic arm along the position to be welded in the transformer tank.

[0010] Preferably, a sliding cavity extending along the wire feeding direction is formed inside the connecting rod, and the sliding seat includes a guide section located inside the sliding cavity and slidingly engaged therewith in the axial direction, and a mounting section extending from the front end of the connecting rod. Multiple clamping petals are connected to the mounting section, and the welding wire passes through the center of the sliding seat.

[0011] Its effect is that the axial fit between the guide section and the sliding cavity limits the movement direction of the sliding seat, while the installation section arranges the clamping petals at the front end of the connecting rod, so that the axial force generated by the adhesion of the welding wire can be transmitted to the sliding seat more directly, while maintaining the center relationship between the welding wire and the wire release structure.

[0012] Preferably, the elastic element is a tension spring disposed inside the connecting rod, one end of the tension spring is connected to the connecting rod, and the other end is connected to the sliding seat; when the sliding seat moves in the direction of feeding the welding wire, it stretches the tension spring; after the welding wire is disengaged from the clamping petal, the tension spring pulls the sliding seat to move in the opposite direction.

[0013] Its effect is that the forward movement required for wire release is directly triggered by the wire feeding thrust, and the tension spring stores elastic potential energy when the sliding seat moves forward; after the adhesion is released, the elastic element can provide a reverse reset action, so that the welding head returns from the abnormal wire release state to the normal wire feeding state, without the need for a separate reset drive.

[0014] Preferably, four clamping petals are provided, which are distributed at intervals along the circumference of the welding wire. Each clamping petal is a conductive elastic metal sheet. The rear end of each clamping petal is connected to the sliding seat, and the front end forms a free end that can move radially along the welding wire.

[0015] Its effect is that multiple clamping petals can form conductive sliding contact with the welding wire from different positions around the circumference, and the four-petal structure makes the circumferential contact more uniform; the clamping petals themselves are elastic, so that they can generate a radial expansion tendency when the limiting constraint is reduced, thereby converting the axial forward movement into a change in the space through which the welding wire passes.

[0016] Preferably, the limiting rods on the outer side of each clamping petal are correspondingly set to the clamping petal, the limiting ring is fixed inside the front end of the protective sleeve, and each limiting rod protrudes in a direction away from the welding wire axis and slides against the inner wall of the limiting ring.

[0017] Its effect is that the limiting rod, as the force transmission part between the clamping petal and the limiting ring, moves axially synchronously with the clamping petal; the limiting ring remains fixed, thereby enabling the axial displacement of the sliding seat to control the closing or opening of the clamping petal through the relative position change of the limiting rod and the limiting ring.

[0018] Preferably, the limiting ring has a central through hole coaxial with the welding wire, and a guide cone surface is formed on the inner wall of the central through hole, with the small diameter side of the guide cone surface facing the connecting rod and the large diameter side facing the front end of the protective sleeve; when the sliding seat moves forward, the limiting rod moves from the small diameter side to the large diameter side, and the maximum movement position of the limiting rod is located inside the large diameter end of the guide cone surface.

[0019] Its effect is that the small diameter side forms a strong radial restriction on the limiting rod under normal wire feeding conditions. As the limiting rod moves towards the large diameter side, its available radial space gradually increases, and the clamping petals can unfold smoothly. The maximum movement position is still within the range of the guide cone surface, which can maintain the cooperation relationship between the limiting rod and the limiting ring, and facilitate subsequent reverse reset.

[0020] Preferably, a protective air channel is formed inside the connecting rod, and multiple air outlets are provided and distributed at intervals along the circumference of the connecting rod; an air guiding space is formed between the inner wall of the protective sleeve and the outer wall of the connecting rod, and the multiple air outlets are respectively connected to the protective air channel and the air guiding space.

[0021] Its effect is that after the protective gas is delivered from inside the connecting rod to the front, it can enter the gas guiding space inside the protective sleeve through multiple circumferentially distributed gas outlets, and be distributed to the front end of the welding wire from the gas guiding space, thus avoiding the protective gas from entering the front end area from only a single circumferential position.

[0022] Preferably, the protective air channel is connected to the moving space of the sliding seat, and a ventilation gap extending along the axial direction of the connecting rod is formed between the outer periphery of the sliding seat and the inner wall of the connecting rod. The ventilation gap is connected to the air outlet, and the sliding seat remains offset from the inner end of the air outlet during its moving stroke.

[0023] Its effect is that the ventilation gap between the sliding seat and the connecting rod provides a continuous flow path for the protective gas to bypass the sliding seat, and the vent avoids the movement coverage area of ​​the sliding seat. As the sliding seat moves from the initial position to the release position, the protective gas can still continuously enter the air guiding space of the protective sleeve through the vent from the inside of the connecting rod.

[0024] Preferably, a first venting gap is formed between the inner wall of the limiting ring and the outer side of the clamping petal, and a second venting gap is formed between two adjacent clamping petals. The gas guiding space is connected to the first venting gap and the second venting gap respectively. When the clamping petal switches from the retracted state to the unfolded state, the flow area of ​​the second venting gap increases, so that the protective gas can be discharged to the front end of the clamping petal and around the welding wire through the second venting gap.

[0025] Its effects are as follows: when the clamping petals retract, the shielding gas can flow forward mainly along the outer periphery of the clamping petals; after the clamping petals unfold due to adhesion triggering, the second gas outlet gap between the petals increases, allowing the shielding gas to obtain a more direct flow path toward the front end of the clamping petals and around the welding wire. This helps maintain the shielding gas coverage in the wire release area and helps reduce the possibility of molten metal continuing to spread to the surface of the clamping petals and re-adheding. The fusion connection already formed between the welding wire and the clamping petals is still released by the mechanical separation effect generated by the unfolding of the clamping petals.

[0026] By adopting the above technical solution, the beneficial effects of this application are as follows: 1. This application uses the wire feeding force that still exists after the welding wire is abnormally stuck as the triggering force for the wire release action. The welding wire drives the sliding seat to move forward through the clamping petals. After the limiting rod moves along the guide cone to the large diameter side, it releases the radial constraint on the clamping petals, so that multiple clamping petals unfold outward and expand the space through which the welding wire passes. This forms a direct force chain from abnormal sticking to mechanical wire release, reducing the situation of stopping the machine and disassembling the welding gun due to wire jamming.

[0027] 2. This application uses an elastic element to cooperate with the sliding seat to store reset energy when the sliding seat moves forward to release the wire, and pulls the sliding seat back to the initial position after the welding wire is detached; the limit rod returns from the large diameter side of the guide cone to the small diameter side during the reset process, so that the clamping petals re-close, realizing the continuous connection between the wire release action and the reset action in the same axial motion chain.

[0028] 3. This application uses the cooperation of the limiting rod, the limiting ring and the guide cone surface to convert the axial displacement of the sliding seat into the radial expansion change of the free end of the clamping petal. The clamping petal simultaneously undertakes the conductive sliding contact in the normal state and the wire release function in the abnormal state, reducing the need for additional execution structures for detecting adhesion and actively driving the expansion of the clamping petal.

[0029] 4. In this application, the protective gas channel, the gas outlet, the gas guiding space and the gas outlet gap between the clamping petals are arranged in the same welding head. When the clamping petals switch from the closed state to the open state, the flow area between the petals changes synchronously with the structural state, so that the protective gas can flow more directly to the front end of the clamping petals and around the welding wire, and continue to maintain local protective gas coverage during the mechanical wire release process. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the welding equipment in this application.

[0031] Figure 2 This is a schematic diagram of the installation end of the welding equipment in this application from another perspective.

[0032] Figure 3 This is a schematic diagram of the structure of the front of the welding head after the protective sleeve has been removed in this application.

[0033] Figure 4For this application Figure 3 A magnified structural diagram of point A in the middle.

[0034] Figure 5 This is a schematic diagram of the internal structure of the protective sleeve after it has been cut along the axial direction.

[0035] Figure 6 This is a schematic diagram of the assembly structure of the sliding seat, elastic element, clamping flap and limiting ring of this application.

[0036] Figure 7 This is a schematic diagram of the assembly structure of the connecting rod and the clamping and releasing wire structure of this application.

[0037] Figure 8 This is a front view schematic diagram of the structure when the clamping flap of this application is in the unfolded and releasing state.

[0038] Figure 9 This is a front view structural diagram of the clamping petal in the wire feeding state of this application.

[0039] Figure 10 This is a schematic diagram of the connecting rod, its sliding cavity, and its air outlet in this application.

[0040] Figure label: 1. Connecting plate; 11. Connecting hole; 2. Insulating sleeve; 3. Protective sleeve; 4. Connecting rod; 41. Sliding cavity; 42. Vent hole; 5. Sliding seat; 6. Elastic element; 7. Clamping flap; 71. Limiting rod; 8. Limiting ring; 81. Guide cone surface; 9. Welding wire. Detailed Implementation

[0041] The embodiments of this application will be further described below with reference to the accompanying drawings. These embodiments are used to illustrate the structural relationships and working process of this application and are not intended to impose additional limitations on the scope of protection of this application.

[0042] like Figures 1 to 10 As shown, a transformer tank welding device according to this application includes a connecting assembly, a welding head installed at the front end of the connecting assembly, and a welding wire 9 threaded along the axial direction of the welding head. The connecting assembly is used to mount the welding head at the end of a robotic arm, and the robotic arm drives the welding head to move along the welding position of the transformer tank.

[0043] Under normal conditions, the welding head guides the welding wire 9, conducts electricity, and delivers shielding gas. When the welding wire 9 burns back and sticks, the subsequent wire feeding thrust of the welding wire 9 is transmitted to the sliding seat 5 through the front clamping structure. The axial movement of the sliding seat 5 triggers the clamping petals 7 to unfold, allowing the welding wire 9 to resume feeding. Subsequently, the elastic element 6 completes the reset.

[0044] like Figure 1 and Figure 2As shown, the connecting assembly includes a connecting plate 1 and an insulating sleeve 2. The connecting plate 1 is annular with multiple connecting holes 11 arranged circumferentially. Fasteners fix the connecting plate 1 to the mounting position at the end of the robotic arm through the connecting holes 11. The insulating sleeve 2 is located on the side of the connecting plate 1 facing the welding head and is fitted over the rear of the welding head, thus separating the conductive part of the welding head from the connecting part of the robotic arm.

[0045] like Figure 1 , Figure 2 and Figure 5 As shown, the protective sleeve 3 is connected to the front end of the insulating sleeve 2 and extends along the feeding direction of the welding wire 9. The protective sleeve 3 covers the outer periphery of the connecting rod 4, the sliding seat 5, the clamping petal 7 and the limiting ring 8, and its front end has an opening for the welding wire 9 to extend and for the protective gas to be discharged; an annular gas guiding space is left between the inner wall of the protective sleeve 3 and the outer wall of the connecting rod 4.

[0046] Considering the long-term high temperature, welding spatter, and protective gas flow environment at the front of the welding head, the protective sleeve 3 is made of a high-temperature resistant and welding spatter resistant material, and the insulating sleeve 2 is made of a high-temperature resistant insulating material; the connecting rod 4, the sliding seat 5, and the clamping petals 7 are made of metal materials that meet the requirements of conductivity and heat resistance. The sliding mating surfaces of the connecting rod 4 and the sliding seat 5 are kept flat to reduce the resistance when the sliding seat 5 reciprocates and to reduce the possibility of movement jamming caused by welding spatter entering the sliding cavity 41.

[0047] The connecting rod 4 is located inside the protective sleeve 3 and extends along the feeding direction of the welding wire 9. The connecting rod 4 has a hollow structure, and a sliding cavity 41 is formed inside it. The sliding cavity 41 is used to accommodate the sliding seat 5 and limit the axial movement of the sliding seat 5. The front part of the connecting rod 4 is provided with multiple vent holes 42, which are spaced apart around the circumference of the connecting rod 4 and respectively connect the air guiding space inside the connecting rod 4 and the protective sleeve 3.

[0048] In this embodiment, the sliding cavity 41 also constitutes part of the protective gas channel. The portion of the sliding seat 5 located within the sliding cavity 41 is fitted with the inner wall of the sliding cavity 41 with a clearance, forming a continuous venting gap along the axial direction of the connecting rod 4. After the protective gas is input from the rear end of the connecting rod 4, it flows forward through the venting gap and enters the air guiding space within the protective sleeve 3 through the vent 42. The inner end of the vent 42 is located outside the working stroke of the sliding seat 5, ensuring that the vent 42 is not covered when the sliding seat 5 is in its normal position or in the forward release position.

[0049] like Figures 4 to 7As shown, the sliding seat 5 includes a guide section located within the sliding cavity 41 and a mounting section extending from the front end of the connecting rod 4. The outer periphery of the guide section slides axially with the sliding cavity 41 to limit the radial displacement of the sliding seat 5 during movement; the mounting section is located in front of the connecting rod 4 and is used to connect multiple clamping petals 7. The welding wire 9 passes through the middle of the sliding seat 5, maintaining a corresponding center relationship between the welding wire 9, the sliding seat 5, and the front clamping structure.

[0050] like Figure 5 and Figure 6 As shown, the elastic element 6 is located on the side of the sliding seat 5 away from the welding position. In this embodiment, the elastic element 6 is a tension spring, with one end connected to the connecting rod 4 and the other end connected to the sliding seat 5. When the sliding seat 5 moves forward, it stretches the elastic element 6 and stores elastic potential energy; after the forward thrust acting on the sliding seat 5 is released, the elastic element 6 applies a reverse tension force to the sliding seat 5.

[0051] The connecting rod 4, sliding seat 5, and clamping petal 7 maintain a conductive connection. The connecting rod 4 is electrically connected to the output end of the welding power source, allowing the welding current to be transmitted sequentially through the connecting rod 4, sliding seat 5, and clamping petal 7 to the welding wire 9. The protective sleeve 3 maintains insulation or a gap between itself and the aforementioned conductive parts. Thus, under normal wire feeding conditions, the clamping petal 7 forms both the circumferential contact position of the welding wire 9 and the front conductive part for the transmission of welding current to the welding wire 9.

[0052] like Figures 6 to 9 As shown, there are no fewer than three clamping petals 7, which are spaced apart along the circumference of the welding wire 9. In this embodiment, four clamping petals 7 are specifically used. Each clamping petal 7 is formed of a conductive elastic metal sheet, with its rear end fixedly connected to the mounting section of the sliding seat 5, and its front end being a free end that can move radially along the welding wire 9. The free ends of the four clamping petals 7 together form the passage area of ​​the welding wire 9, and the clamping petals 7 have an elastic tendency to expand outward when there is no external radial constraint.

[0053] like Figures 6 to 9 As shown, each clamping petal 7 is provided with a limiting rod 71 on its outer side, and the four limiting rods 71 ​​correspond one-to-one with the four clamping petals 7. The limiting rods 71 ​​protrude in a direction away from the axis of the welding wire 9 and move axially synchronously with the clamping petals 7 and the sliding seat 5. The limiting ring 8 is fixedly installed inside the front end of the protective sleeve 3 and surrounds the multiple clamping petals 7, and its central through hole corresponds to the welding wire 9.

[0054] The inner wall of the central through hole of the limiting ring 8 forms a guide cone surface 81. The guide cone surface 81 gradually transitions from the small diameter side to the large diameter side along the feeding direction of the welding wire 9, with the small diameter side facing the connecting rod 4 and the large diameter side facing the front end of the protective sleeve 3. The outer end of the limiting rod 71 slides against the guide cone surface 81, so the axial position change of the limiting rod 71 on the guide cone surface 81 will change the radial movement space that the clamping petal 7 can obtain.

[0055] like Figure 7 and Figure 9 As shown, when the equipment is in normal wire feeding mode, the sliding seat 5 is in the initial rear position, the elastic element 6 is in an unstretched state, and the limiting rod 71 is located on the small diameter side of the guide cone surface 81. The guide cone surface 81 restricts the clamping petals 7 from expanding outward through the limiting rod 71, so that the free ends of the four clamping petals 7 approach the welding wire 9 and form elastic sliding contact with the welding wire 9. The contact force of the clamping petals 7 on the welding wire 9 allows the welding wire 9 to pass continuously along the axial direction under the action of the wire feeding mechanism.

[0056] During normal welding, the wire feeding mechanism continuously feeds the welding wire 9 forward. The welding wire 9 slides relative to the clamping petal 7. The friction generated by the sliding is insufficient to overcome the reset effect of the elastic element 6 and drive the sliding seat 5 forward. Therefore, the clamping petal 7 remains in a closed state. The welding current is transmitted to the welding wire 9 through the clamping petal 7, while the shielding gas enters the front of the protective sleeve 3 from inside the connecting rod 4 through the vent hole 42.

[0057] When a brief mismatch occurs between the feeding and melting of the welding wire 9, the end of the welding wire 9 may burn back into the welding head, causing the molten metal to fuse and adhere to the front end of one or more clamping petals 7. At this time, the welding wire 9 and the clamping petals 7 change from a normal relative sliding state to a follow-up state that can transmit a larger axial force. The subsequent wire feeding thrust is transmitted from the welding wire 9 to the clamping petals 7, and then from the clamping petals 7 to the sliding seat 5.

[0058] like Figure 4 , Figure 6 and Figure 8 As shown, under the aforementioned wire feeding force, the sliding seat 5 moves along the sliding cavity 41 toward the front end of the protective sleeve 3, while simultaneously stretching the elastic element 6. The clamping petal 7 moves forward synchronously with the sliding seat 5, and each limiting rod 71 moves along the guide cone surface 81 from the small diameter side to the large diameter side, thereby reducing the radial restriction formed by the limiting ring 8 on the limiting rod 71.

[0059] As the limiting rod 71 continues to move towards the larger diameter side, each clamping petal 7 expands outwards due to its own elasticity, and the area through which the welding wire is enclosed by the four free ends expands. Since the multiple clamping petals 7 leave the welding wire 9 in different radial directions, the fusion position between the clamping petals 7 and the welding wire 9 is subjected to radial tension and shearing. When the fusion relationship is broken, the welding wire 9 can move forward relative to the clamping petals 7 again under the action of the wire feeding mechanism.

[0060] The forward movement range of the limiting rod 71 is limited to within the large diameter end of the guide cone surface 81, so that when the clamping petal 7 obtains the required unfolding amount for wire release, the limiting rod 71 still maintains its engagement with the limiting ring 8. After the welding wire 9 is released from the clamping petal 7, the continuous forward force transmitted to the sliding seat 5 through the adhesion position decreases, and the elastic element 6 then pulls the sliding seat 5 to move backward. The limiting rod 71 returns from the large diameter side of the guide cone surface 81 to the small diameter side, and the clamping petal 7 retracts and resumes sliding contact with the welding wire 9.

[0061] like Figure 5 , Figure 7 and Figure 10 As shown, the protective gas is conveyed forward along the inside of the connecting rod 4, and after passing through multiple vent holes 42, it enters the air guiding space between the protective sleeve 3 and the connecting rod 4 and continues to flow towards the front end of the protective sleeve 3. A first air outlet gap is formed between the inner wall of the limiting ring 8 and the outer side of the clamping petals 7, and a second air outlet gap is formed between two adjacent clamping petals 7. Both types of gaps are connected to the air guiding space inside the protective sleeve 3.

[0062] exist Figure 9 In the wire feeding state shown, the second gas outlet gap between adjacent clamping petals 7 is small, and the shielding gas mainly flows along the outer periphery of the clamping petals 7 through the first gas outlet gap to the front end of the welding wire 9. Figure 8 In the unfolded wire release state shown, the clamping petals 7 are separated from each other, which increases the flow area of ​​the second vent gap. The protective gas can also be discharged more directly to the front end of the clamping petal 7 and around the welding wire 9 through the passage formed between the petals.

[0063] The inter-lobe airflow formed after the clamping lobe 7 unfolds is used to maintain the front-end shielding gas coverage in conjunction with the mechanical wire release process, and helps to reduce the possibility of molten metal continuing to spread to the surface of the clamping lobe 7 and re-adhere. This airflow does not act as the main driving force for destroying the fusion connection; the fusion relationship already formed between the welding wire 9 and the clamping lobe 7 is mainly released by the mechanical separation action generated by the radial unfolding of the clamping lobe 7.

[0064] After the clamping petal 7 is reset and retracted under the action of the elastic element 6, the second air outlet gap decreases accordingly, and the main flow path of the protective gas redirects back to the outer periphery of the clamping petal 7. Thus, the front-end protective gas flow path can change with the mechanical state of the clamping petal 7, eliminating the need for a separate gas path switching actuator for the unfolding action of the clamping petal 7.

[0065] Based on the above structure, the working process of this application is as follows: During equipment installation, the connecting assembly is fixed to the end of the robotic arm through the connecting hole 11 on the connecting plate 1. The robotic arm moves the welding head according to the trajectory of the position to be welded in the transformer tank. During normal welding, the wire feeding mechanism continuously pushes the welding wire 9, the clamping petal 7 remains closed and slides in contact with the welding wire 9, the welding current is transmitted to the welding wire 9 through the connecting rod 4, the sliding seat 5 and the clamping petal 7, and the shielding gas is discharged to the front end of the welding wire 9 through the gas outlet 42 and the first gas outlet gap.

[0066] When the welding wire 9 burns back and fuses with the front end of the clamping petal 7, the subsequent wire feeding thrust is transmitted to the sliding seat 5 through the welding wire 9 and the clamping petal 7, causing the sliding seat 5 to move forward and stretch the elastic element 6; the limiting rod 71 moves synchronously from the small diameter side to the large diameter side of the guide cone surface 81, the clamping petal 7 unfolds outward and produces a radial separation effect on the fusion position, and at the same time the second gas outlet gap increases, and the protective gas flows to the wire release area through the inter-petal passage.

[0067] When the welding wire 9 is separated from the clamping petal 7, the welding wire 9 resumes relative sliding, the forward force transmitted to the sliding seat 5 decreases, the elastic element 6 pulls the sliding seat 5 backward, the limiting rod 71 returns to the small diameter side along the guide cone surface 81, the clamping petal 7 retracts, the second gas outlet gap decreases, and the welding head returns to normal wire feeding, electrical conduction and gas supply state.

[0068] This embodiment uses the example of a robotic arm driving a welding head to move along the continuous weld seam of a transformer tank to illustrate the usage process of this application. The specific number of clamping petals 7, the installation form of the connecting components, and the shape of the protective sleeve 3 can be adapted according to the specifications of the welding head, as long as the coordination relationship between the forward movement of the sliding seat 5, the movement of the limiting rod 71 along the guide cone surface 81, and the radial expansion of the clamping petals 7 is maintained.

[0069] The above embodiments are used to illustrate the structural composition and working principle of this application. Without departing from the technical solution disclosed in this application, the conventional size adaptation, connection method adjustment or equivalent replacement of each component can be set according to the assembly conditions of the actual welding equipment.

Claims

1. A transformer tank welding device, comprising a connecting assembly, a welding head connected to the connecting assembly, and a welding wire threaded within the welding head, characterized in that, The welding head includes a protective sleeve, a connecting rod disposed within the protective sleeve, a sliding seat slidably disposed within the connecting rod, an elastic element connecting the sliding seat and the connecting rod, multiple clamping petals connected to the front end of the sliding seat and distributed around the welding wire, and a limiting ring disposed on the outer periphery of the clamping petals; a limiting rod is provided on the outer side of the clamping petal, and a guide cone surface that gradually expands in diameter along the direction of welding wire feeding is provided on the inner side of the limiting ring; when the clamping petal is constrained by the limiting ring, it retracts and contacts the welding wire; when the welding wire and the clamping petal are fused and adhered and continue to be pushed by the wire feeding force, the welding wire drives the sliding seat to move forward through the clamping petal, causing the limiting rod to move along the guide cone surface to the larger diameter side and causing the clamping petal to unfold outward; the elastic element drives the sliding seat to reset after the welding wire is disengaged; the connecting rod is provided with an vent hole communicating with the inside of the protective sleeve, and an vent gap that increases as the clamping petal unfolds is formed between adjacent clamping petals.

2. The transformer tank welding equipment according to claim 1, characterized in that, The connecting assembly includes a connecting plate and an insulating sleeve. The connecting plate has multiple connecting holes spaced apart along the circumference and is detachably connected to the end of the robotic arm through the connecting holes. The insulating sleeve is located on the side of the connecting plate near the welding head and is fitted around the outer periphery of the welding head.

3. The transformer tank welding equipment according to claim 1, characterized in that, The connecting rod forms a sliding cavity extending along the wire feeding direction. The sliding seat includes a guide section located in the sliding cavity and slidingly engaged therewith in its axial direction, and a mounting section extending from the front end of the connecting rod. Multiple clamping petals are connected to the mounting section, and the welding wire passes through the center of the sliding seat.

4. The transformer tank welding equipment according to claim 1, characterized in that, The elastic element is a tension spring installed inside the connecting rod. One end of the tension spring is connected to the connecting rod, and the other end is connected to the sliding seat. When the sliding seat moves in the direction of feeding the welding wire, it stretches the tension spring. After the welding wire is released from the clamping petals, the tension spring pulls the sliding seat to move in the opposite direction.

5. The transformer tank welding equipment according to claim 1, characterized in that, The clamping petals are provided in four ways, and the four clamping petals are distributed at intervals along the circumference of the welding wire. Each clamping petal is a conductive elastic metal sheet. The rear end of each clamping petal is connected to the sliding seat, and the front end forms a free end that can move radially along the welding wire.

6. The transformer tank welding equipment according to claim 1, characterized in that, Each clamping petal has a corresponding limiting rod on its outer side. The limiting ring is fixed inside the front end of the protective sleeve. Each limiting rod protrudes in a direction away from the welding wire axis and slides against the inner wall of the limiting ring.

7. The transformer tank welding equipment according to claim 6, characterized in that, The limiting ring has a central through hole coaxial with the welding wire, and a guide cone surface is formed on the inner wall of the central through hole. The small diameter side of the guide cone surface faces the connecting rod, and the large diameter side faces the front end of the protective sleeve. When the sliding seat moves forward, the limiting rod moves from the small diameter side to the large diameter side, and the maximum movement position of the limiting rod is located inside the large diameter end of the guide cone surface.

8. The transformer tank welding equipment according to claim 1, characterized in that, A protective air channel is formed inside the connecting rod, and multiple air outlets are provided and distributed at intervals along the circumference of the connecting rod; an air guiding space is formed between the inner wall of the protective sleeve and the outer wall of the connecting rod, and the multiple air outlets are respectively connected to the protective air channel and the air guiding space.

9. A transformer tank welding device according to claim 8, characterized in that, The protective air channel is connected to the moving space of the sliding seat. A ventilation gap extending along the axial direction of the connecting rod is formed between the outer periphery of the sliding seat and the inner wall of the connecting rod. The ventilation gap is connected to the air outlet, and the sliding seat remains offset from the inner end of the air outlet within its moving stroke.

10. A transformer tank welding device according to claim 8, characterized in that, A first venting gap is formed between the inner wall of the limiting ring and the outer side of the clamping petal, and a second venting gap is formed between two adjacent clamping petals. The air guiding space is connected to the first venting gap and the second venting gap respectively. When the clamping petal switches from the retracted state to the unfolded state, the flow area of ​​the second venting gap increases, so that the protective gas can be discharged to the front end of the clamping petal and around the welding wire through the second venting gap.

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