Spot welding electrode structure, resistance welding machine and cavity and plate welding method

Abstract

The invention provides a spot welding electrode structure, a resistance welding machine and a cavity and plate welding method. The spot welding electrode structure comprises a first electrode cap and a second electrode cap. When a to-be-welded plate and a to-be-welded cavity need to be welded and formed, the welding face of the to-be-welded plate is controlled to abut against the welding face of the to-be-welded cavity, a first electrode cap is controlled to abut against the face, away from the welding face, of the to-be-welded plate, and the bottom wall of a containing cavity of a second electrode cap is controlled to abut against the face, away from the welding face, of the to-be-welded cavity. And the side wall of the containing cavity is in limiting fit with the periphery of the to-be-welded cavity, and the first electrode cap and the second electrode cap are in current communication through the to-be-welded plate and the to-be-welded cavity, so that the to-be-welded plate and the to-be-welded cavity are welded and fixed. The spot-welding electrode structure provided by the invention not only can be suitable for welding a flat plate structure with a flat and uniform surface, but also can be suitable for welding a plate with a relatively complex external shape and a cavity body.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy plate welding, and in particular to a spot welding electrode structure, a resistance welding machine, and a cavity and plate welding method. Background Art

[0002] At present, with the rapid development of the automobile industry, lightweighting has become an important trend in automobile design. Aluminum alloy, as a lightweight and high-strength material, has gradually replaced traditional steel and become one of the important materials for automobile manufacturing; the application of aluminum alloy can not only reduce the weight of the car and improve fuel efficiency, but also reduce emissions and meet environmental protection requirements.

[0003] As an efficient welding process, resistance spot welding has been widely used in the welding process of aluminum alloy plates and profiles due to its advantages of low cost, fast speed and high connection strength. Common aluminum alloy materials in automobiles include cavities and plates. The cavity usually has a cavity inside, and the plate is usually a thin plate structure. In existing welding work, it is often necessary to weld the cavity and the plate to fix them into shape.

[0004] However, the existing resistance spot welding machines used on aluminum alloy materials are only suitable for flat plate structures with smooth and uniform welding surfaces. They can achieve good welding fixation between two flat plate parts, but in the process of welding cavities and plates, the existing resistance spot welding machines can neither adapt to the welding of plates or cavities with more complex external shapes, nor ensure that a large welding current is transmitted to the welding surface through the internal cavity of the cavity. As a result, the welding quality of the existing resistance welding machines for cavities and plates with more complex external shapes is poor, and they cannot meet the modern industrial demand for the welding and forming of aluminum alloy cavities and plates. Summary of the invention

[0005] The present invention provides a spot welding electrode structure, a resistance electric welding machine and a method for welding a cavity body and a plate, so as to solve the problem that the resistance spot welding machine in the prior art cannot efficiently weld and fix a cavity body with a cavity inside to a plate body.

[0006] In order to solve the above problems, according to one aspect of the present invention, a spot welding electrode structure is provided, comprising: a first electrode cap and a second electrode cap, the first electrode cap and the second electrode cap are electrically connected to the external electrode respectively; the first electrode cap is used to abut against the plate to be welded, the second electrode cap has a receiving cavity inside, at least a part of the cavity to be welded is arranged in the receiving cavity, and is limitedly matched with the inner wall of the receiving cavity; wherein, when it is necessary to weld the plate to be welded and the cavity to be welded, the welding surface of the plate to be welded is controlled to abut against the welding surface of the cavity to be welded, the first electrode cap abuts against the side of the plate to be welded away from the welding surface, the bottom wall of the receiving cavity of the second electrode cap abuts against the side of the cavity to be welded away from the welding surface, and the side wall of the receiving cavity is limitedly matched with the outer periphery of the cavity to be welded, the first electrode cap and the second electrode cap jointly apply opposite forces so that the welding surface of the plate to be welded and the welding surface of the cavity to be welded are pressed with a set pressure, and the first electrode cap and the second electrode cap are connected by electric current through the plate to be welded and the cavity to be welded, so as to weld and fix the plate to be welded and the cavity to be welded.

[0007] Furthermore, the abutting surface of the first electrode cap for abutting against the plate to be welded is a spherical surface or a plane; the size of the accommodating cavity of the second electrode cap is adapted to the external size of the cavity to be welded.

[0008] Furthermore, the first electrode cap includes a connector and a welding head, the welding head is arranged on the connector, the connector is used to be electrically connected to the external electrode, the connector is a cylindrical structure, and the diameter of the cylindrical structure is in the range of 15mm to 25mm; the welding head is used to abut against the plate to be welded.

[0009] Furthermore, when the abutting surface of the welding head used to abut the plate to be welded is a spherical surface, the arc curvature radius of the spherical surface is in the range of 20mm to 100mm; when the abutting surface of the welding head used to abut the plate to be welded is a plane, the plane is a circular surface, and the diameter of the circular surface is in the range of 4mm to 8mm.

[0010] Furthermore, the total contact area between the inner wall of the accommodating cavity and the cavity to be welded is ≥ 1000mm 2 .

[0011] Furthermore, when the plate to be welded and the cavity to be welded are made of aluminum alloy material, the material used for the first electrode cap and / or the second electrode cap is aluminum oxide copper material.

[0012] According to another aspect of the present invention, a resistance welding machine is provided, which includes the above-mentioned spot welding electrode structure, and also includes a power supply, a first electrode rod and a second electrode rod, the first electrode rod and the second electrode rod are respectively connected to the power supply through a circuit; the first electrode cap has a first mounting hole, at least a portion of the first electrode rod is located in the first mounting hole, and has an interference fit with the first mounting hole; the second electrode cap has a second mounting hole, at least a portion of the second electrode rod is located in the second mounting hole, and has an interference fit with the second mounting hole; wherein, when welding a plate to be welded and a cavity to be welded, the first electrode rod, the first electrode cap, the plate to be welded, the cavity to be welded, the second electrode cap and the second electrode rod are connected in series to conduct the welding current.

[0013] According to another aspect of the present invention, a method for welding a cavity and a plate is provided, and the method for welding a cavity and a plate is applied to the above-mentioned spot welding electrode structure, and the method for welding a cavity and a plate comprises the following steps: an installation step: abutting the welding surface of the plate to be welded with the welding surface of the cavity to be welded, controlling the first electrode cap to abut the side of the plate to be welded away from the welding surface, controlling the bottom wall of the accommodating cavity of the second electrode cap to abut the side of the cavity to be welded away from the welding surface, and the side wall of the accommodating cavity cooperates with the peripheral limit of the cavity to be welded, applying opposite forces to the first electrode cap and the second electrode cap, so that the welding surface of the plate to be welded and the welding surface of the cavity to be welded are pressed with a set pressure; a welding step: adjusting the set The pressure is within the range of 3.0kN to 5.0kN, the current between the first electrode cap and the second electrode cap is adjusted to be within the range of 20kA to 35kA, and the power-on time is within the range of 100ms to 300ms, so as to weld and fix the welding surface of the plate to be welded and the welding surface of the cavity to be welded; maintaining step: after the welding step is completed, adjust the set pressure within the range of 1.0kN to 3.0kN, and maintain the set pressure for a time within the range of 100ms to 300ms to wait for the molten metal at the welding surface to be completely solidified; releasing step: after the maintaining step is completed, adjust the first electrode cap and / or the second electrode cap to release the set pressure to complete a welding of the plate to be welded and the cavity to be welded.

[0014] Furthermore, between the installation step and the welding step, the method for welding the cavity and the plate also includes a preheating step: adjusting the set pressure within the range of 1.0kN to 3.0kN, adjusting the connection current between the first electrode cap and the second electrode cap within the range of 10kA to 20kA, and adjusting the power-on time within the range of 10ms to 100ms, so as to preheat the plate to be welded and the cavity to be welded.

[0015] Furthermore, the plate to be welded is an aluminum alloy plate with a thickness in the range of 1.0 mm to 2.0 mm; the cavity to be welded is an aluminum alloy cavity with a wall thickness in the range of 1.0 mm to 5.0 mm.

[0016] The technical scheme of the present invention is applied, and the present invention provides a spot welding electrode structure, comprising: a first electrode cap and a second electrode cap, the first electrode cap and the second electrode cap are electrically connected to the external electrode respectively; the first electrode cap is used to abut against the plate to be welded, and the second electrode cap has a receiving cavity inside, at least a part of the cavity to be welded is arranged in the receiving cavity, and is limitedly matched with the inner wall of the receiving cavity; wherein, when it is necessary to weld the plate to be welded and the cavity to be welded, the welding surface of the plate to be welded is controlled to abut against the welding surface of the cavity to be welded, the first electrode cap abuts against the side of the plate to be welded away from the welding surface, the bottom wall of the receiving cavity of the second electrode cap abuts against the side of the cavity to be welded away from the welding surface, and the side wall of the receiving cavity is limitedly matched with the outer periphery of the cavity to be welded, the first electrode cap and the second electrode cap jointly apply opposite forces so that the welding surface of the plate to be welded and the welding surface of the cavity to be welded are pressed with a set pressure, and the first electrode cap and the second electrode cap are connected by electric current through the plate to be welded and the cavity to be welded, so as to weld and fix the plate to be welded and the cavity to be welded.

[0017] The spot welding electrode structure proposed in the present invention realizes efficient welding of the plate to be welded and the cavity to be welded by setting the first electrode cap and the second electrode cap to work together; by setting the second electrode cap to have a accommodating cavity inside, at least a part of the cavity to be welded is arranged in the accommodating cavity, and cooperates with the inner wall limit of the accommodating cavity, so that the spot welding electrode structure proposed in the present invention can be not only suitable for flat plate structures with flat and uniform welding surfaces, but also suitable for welding plates and cavities with more complex external shapes. The setting of the accommodating cavity can ensure that a large welding current is transmitted to the welding surface through the internal cavity of the cavity, thereby ensuring that the resistance welding machine using the spot welding electrode structure proposed in the present invention has high welding quality for the cavity and the plate with more complex external shapes, and can effectively meet the use requirements of modern industry for the welding and forming of aluminum alloy cavities and plates in actual use; the spot welding electrode structure proposed in the present invention has a simple structure and low cost, is easy to assemble and subsequently maintain, and can be combined with the cavity and plate welding method in the subsequent process, has the advantages of simple process, low equipment cost, strong applicability, high welding quality, high welding efficiency, etc., and is suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A partial structural schematic diagram of the spot welding electrode structure provided by the first embodiment of the present invention during welding is shown;

[0020] Figure 2A partial structural schematic diagram of a spot welding electrode structure provided by the second embodiment of the present invention during welding is shown;

[0021] Figure 3 A schematic diagram of a part of the structure of the spot welding electrode structure provided by the third embodiment of the present invention during welding is shown;

[0022] Figure 4 A schematic diagram of a weld at a welding surface position of a plate to be welded and a cavity to be welded provided by an embodiment of the present invention after welding is completed is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. First electrode cap; 11. Connector; 12. Welding head;

[0025] 20. Second electrode cap; 21. Accommodating cavity;

[0026] 30. Plates to be welded;

[0027] 40. Cavity to be welded. DETAILED DESCRIPTION

[0028] 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, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0029] like Figures 1 to 4As shown, an embodiment of the present invention provides a spot welding electrode structure, including: a first electrode cap 10 and a second electrode cap 20, the first electrode cap 10 and the second electrode cap 20 are electrically connected to the external electrode respectively; the first electrode cap 10 is used to abut against the plate 30 to be welded, the second electrode cap 20 has a receiving cavity 21 inside, at least a part of the cavity 40 to be welded is arranged in the receiving cavity 21, and is limitedly matched with the inner wall of the receiving cavity 21; wherein, when it is necessary to weld the plate 30 to be welded and the cavity 40 to be welded, the welding surface of the plate 30 to be welded is controlled to abut against the welding surface of the cavity 40 to be welded, and the first electrode cap 10 is used to abut against the plate 30 to be welded, and the second electrode cap 20 has a receiving cavity 21 inside, and at least a part of the cavity 40 to be welded is arranged in the receiving cavity 21, and is limitedly matched with the inner wall of the receiving cavity 21; wherein, when it is necessary to weld the plate 30 to be welded and the cavity 40 to be welded, the welding surface of the plate 30 to be welded is controlled to abut against the welding surface of the cavity 40 to be welded, and the first electrode cap 10 is used to abut against the plate 30 to be welded, and the second electrode cap 20 is used to abut against the external electrode respectively; The pole cap 10 abuts against the side of the plate 30 to be welded which is away from the welding surface, the bottom wall of the accommodating cavity 21 of the second electrode cap 20 abuts against the side of the cavity 40 to be welded which is away from the welding surface, and the side wall of the accommodating cavity 21 cooperates with the outer peripheral limit of the cavity 40 to be welded, the first electrode cap 10 and the second electrode cap 20 jointly apply opposite forces to press the welding surface of the plate 30 to be welded and the welding surface of the cavity 40 to be welded at a set pressure, the first electrode cap 10 and the second electrode cap 20 are connected by electric current through the plate 30 to be welded and the cavity 40 to be welded, so as to weld and fix the plate 30 to be welded and the cavity 40 to be welded.

[0030] The spot welding electrode structure proposed in the present invention realizes efficient welding of the plate 30 to be welded and the cavity 40 to be welded by setting the first electrode cap 10 and the second electrode cap 20 to work together; by setting the second electrode cap 20 to have a receiving cavity 21 inside, at least a part of the cavity 40 to be welded is set in the receiving cavity 21, and the receiving cavity 21 is limited with the inner wall of the receiving cavity 21, so that the spot welding electrode structure proposed in the present invention can be applied not only to flat plate structures with smooth and uniform welding surfaces, but also to the welding of plates and cavities with relatively complex external shapes, and the setting of the receiving cavity 21 can ensure a large The welding current is transmitted to the welding surface through the internal cavity of the cavity, thereby ensuring that the resistance welding machine using the spot welding electrode structure proposed in the present invention has high welding quality for the cavity and the plate with a relatively complex external shape, and can effectively meet the modern industrial demand for the welding and forming of aluminum alloy cavities and plates in actual use; the spot welding electrode structure proposed in the present invention has a simple structure and low cost, is easy to assemble and subsequently maintain, and can be combined with the cavity and plate welding method subsequently, and has the advantages of simple process, low equipment cost, strong applicability, high welding quality, high welding efficiency, etc., and is suitable for large-scale promotion and use.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, the abutting surface of the first electrode cap 10 for abutting against the plate 30 to be welded is a spherical surface or a plane; the size of the accommodating cavity 21 of the second electrode cap 20 is adapted to the external size of the cavity 40 to be welded.

[0032] By setting the abutting surface of the first electrode cap 10 to be spherical or flat, the first electrode cap 10 can determine a more suitable contact mode according to the surface characteristics of different plates 30 to be welded. The spherical surface can adapt to curved surfaces, while the flat surface is more suitable for flat plates, which makes the welding process more flexible and improves the adaptability to various plates 30 to be welded. By setting the size of the accommodating cavity 21 of the second electrode cap 20 to match the external size of the cavity 40 to be welded, it is ensured that the second electrode cap 20 is in good contact with the cavity 40 to be welded, avoiding ineffective loss of current during welding, and ensuring welding efficiency and stability of welding points.

[0033] like Figure 1 , Figure 2 and Figure 3 As shown, the first electrode cap 10 includes a connector 11 and a welding head 12. The welding head 12 is arranged on the connector 11. The connector 11 is used to be electrically connected to an external electrode. The connector 11 is a cylindrical structure with a diameter in the range of 15 mm to 25 mm. The welding head 12 is used to abut against the plate 30 to be welded.

[0034] By providing the connector 11 and the welding head 12, a stable current channel and welding contact point are provided. The connector 11 with a cylindrical structure has a certain mechanical strength, which ensures the structural stability and conductive performance of the first electrode cap 10. The welding head 12 contacts the plate 30 to be welded and can effectively transmit current and pressure, thereby forming a high-quality weld.

[0035] Optionally, when the abutting surface of the welding head 12 used to abut the plate 30 to be welded is a spherical surface, the arc curvature radius of the spherical surface is in the range of 20mm to 100mm; when the abutting surface of the welding head 12 used to abut the plate 30 to be welded is a plane, the plane is a circular surface, and the diameter of the circular surface is in the range of 4mm to 8mm.

[0036] By designing the curvature radius and size of the abutting surface of the welding joint 12, the contact area and pressure distribution of the welding point can be adjusted, ensuring heat concentration and optimization of current distribution during the welding process, thereby reducing welding defects (such as spatter and unfused defects) and improving welding quality and efficiency.

[0037] Specifically, the total contact area between the inner wall of the accommodating cavity 21 and the cavity 40 to be welded is ≥ 1000 mm 2 .

[0038] By setting the contact area between the inner wall of the accommodating cavity 21 and the cavity 40 to be welded, a larger contact area is ensured, which is conducive to the uniform distribution of current and the effective transfer of heat, avoiding deformation and welding defects caused by local overheating, and improving the controllability of the welding process and the consistency of welding quality.

[0039] Optionally, when the plate 30 to be welded and the cavity 40 to be welded are made of aluminum alloy material, the material used for the first electrode cap 10 and / or the second electrode cap 20 is aluminum oxide copper material.

[0040] Using alumina copper material as the material of the electrode cap not only has good electrical conductivity and thermal conductivity, but also can increase the service life of the electrode, reduce electrode wear during welding, and reduce equipment maintenance costs; at the same time, the high hardness and wear resistance of alumina copper material also ensure the structural integrity of the electrode cap under high voltage and the stability of current transmission.

[0041] In a specific embodiment of the present invention, copper or copper alloy material can be used as the material of the first electrode cap 10 and the second electrode cap 20, which not only ensures good electrical conductivity and thermal conductivity, but also extends the service life of the electrode; in addition, it can also be combined with the existing preheating, dynamic current adjustment and ultrasonic detection system to further ensure the controllability of the welding process and the consistency of the welding results, providing technical guarantee for the high-quality welding of the aluminum alloy material cavity 40 to be welded and the plate 30 to be welded.

[0042] The present invention also provides a resistance welding machine, which includes the above-mentioned spot welding electrode structure, and also includes a power supply, a first electrode rod and a second electrode rod, the first electrode rod and the second electrode rod are respectively connected to the power supply through a circuit; a first electrode cap 10 has a first mounting hole, at least a portion of the first electrode rod is located in the first mounting hole, and has an interference fit with the first mounting hole; a second electrode cap 20 has a second mounting hole, at least a portion of the second electrode rod is located in the second mounting hole, and has an interference fit with the second mounting hole; wherein, when welding a plate 30 to be welded and a cavity 40 to be welded, the first electrode rod, the first electrode cap 10, the plate 30 to be welded, the cavity 40 to be welded, the second electrode cap 20 and the second electrode rod are connected in series to conduct welding current.

[0043] The resistance welding machine proposed in the present invention includes the above-mentioned spot welding electrode structure. By setting a power supply, a first electrode rod and a second electrode rod in series connection, the resistance welding machine can accurately control the welding current and pressure and optimize the welding parameters, thereby improving the welding efficiency while ensuring the welding quality; by setting an interference fit installation method, a stable connection between the electrode cap and the electrode rod is ensured, loosening and current loss during welding are reduced, and the electrode cap is prevented from sticking to the welding workpiece after welding is completed.

[0044] The present invention also provides a cavity and plate welding method, which is applied to the above-mentioned spot welding electrode structure, and the cavity and plate welding method comprises the following steps: installation step: abutting the welding surface of the plate 30 to be welded with the welding surface of the cavity 40 to be welded, controlling the first electrode cap 10 to abut against the side of the plate 30 to be welded away from the welding surface, controlling the bottom wall of the accommodating cavity 21 of the second electrode cap 20 to abut against the side of the cavity 40 to be welded away from the welding surface, and the side wall of the accommodating cavity 21 cooperates with the outer peripheral limit of the cavity 40 to be welded, applying opposite forces to the first electrode cap 10 and the second electrode cap 20, so that the welding surface of the plate 30 to be welded and the welding surface of the cavity 40 to be welded are pressed with a set pressure; welding step: adjusting the set pressure The set pressure is within the range of 3.0kN to 5.0kN, the current between the first electrode cap 10 and the second electrode cap 20 is adjusted to be within the range of 20kA to 35kA, and the power-on time is within the range of 100ms to 300ms, so as to weld and fix the welding surface of the plate 30 to be welded and the welding surface of the cavity 40 to be welded; maintenance step: after the welding step is completed, adjust the set pressure within the range of 1.0kN to 3.0kN, and maintain the set pressure for a time within the range of 100ms to 300ms to wait for the molten metal at the welding surface to be completely solidified; release step: after the maintenance step is completed, adjust the first electrode cap 10 and / or the second electrode cap 20 to release the set pressure to complete a welding of the plate 30 to be welded and the cavity 40 to be welded.

[0045] The cavity and plate welding method proposed in the present invention can effectively weld the cavity 40 to be welded and the plate 30 to be welded together by setting parameter ranges such as welding pressure, current intensity and power-on time, and ensures the formation of weld points through precise control of welding parameters; at the same time, the maintenance step and the release step further improve the consistency of welding quality and the cooling effect after welding, reduce stress concentration and deformation, and improve the reliability and aesthetics of the welded structure.

[0046] Optionally, between the installation step and the welding step, the cavity and plate welding method also includes a preheating step: adjusting the set pressure within the range of 1.0kN to 3.0kN, adjusting the connecting current between the first electrode cap 10 and the second electrode cap 20 within the range of 10kA to 20kA, and adjusting the power-on time within the range of 10ms to 100ms to preheat the plate 30 to be welded and the cavity 40 to be welded.

[0047] By performing a preheating step before welding, the parts to be welded can be heated evenly, reducing the thermal shock during welding and the possibility of spatter during welding. At the same time, preheating can promote the fluidity of the metal, which is beneficial to the concentration of heat at the weld point, which is beneficial to the formation of the weld point, and improves the welding quality and the stability of the welding process.

[0048] Specifically, the plate 30 to be welded is an aluminum alloy plate with a thickness in the range of 1.0 mm to 2.0 mm; the cavity 40 to be welded is an aluminum alloy cavity with a wall thickness in the range of 1.0 mm to 5.0 mm.

[0049] By defining the materials and thicknesses of the plate 30 to be welded and the cavity 40 to be welded, the preferred applicable range of the welding method is further clarified. For the thickness ranges of the aluminum alloy materials defined above, the method of the present invention can provide preferred welding parameter settings, ensuring welding quality and efficiency. At the same time, it also provides guidance for subsequent production and maintenance, avoiding welding defects (such as spatter, cracks, and lack of fusion, etc.) caused by different material characteristics or thicknesses.

[0050] It should be noted that: Figure 1 FIG. shows a partial structural schematic diagram of the spot welding electrode structure provided in Embodiment 1 of the present invention when welding the plate 30 to be welded and the "square-shaped" cavity 40 to be welded; Figure 2 FIG. shows a partial structural schematic diagram of the spot welding electrode structure provided in Embodiment 2 of the present invention when welding the plate 30 to be welded and the "horizontal rectangle-shaped" cavity 40 to be welded; Figure 3 FIG. shows a partial structural schematic diagram of the spot welding electrode structure provided in Embodiment 3 of the present invention when welding the plate 30 to be welded and the "elliptical" cavity 40 to be welded; Figure 4 FIG. shows a weld seam schematic diagram at the welding surface position after welding the plate 30 to be welded and the cavity 40 to be welded provided in the embodiment of the present invention. It can be clearly seen from Figure 4 that when applying the structure and method proposed by the present invention to weld the cavity 40 to be welded with a wall thickness of 3.08 mm and the plate 30 to be welded with a thickness of 1.05 mm, the formed weld seam has high quality and no defects, and the size of the solder joint is 4.73 mm, meeting the actual welding quality and strength requirements.

[0051] In a specific embodiment of the present invention, the plate 30 to be welded is an aluminum alloy plate, and the cavity 40 to be welded is an aluminum alloy cavity. The data such as the grades, thicknesses, relevant welding parameters, and result remarks of the two are shown in Table 1 below:

[0052] Table 1

[0053]

[0054]

[0055] The 7 comparative examples in Table 1 above are welded using existing resistance welding machines, so as to facilitate comparison with the actual effects of the present invention. Based on the data in Table 1 above, it can be seen that the present invention significantly improves the welding quality and efficiency by optimizing the design of the first electrode cap 10 and the second electrode cap 20 and the limitation of welding parameters. The specially designed second electrode cap 20 can distribute pressure and current more evenly, avoiding deformation of the cavity 40 to be welded and burn-through of the plate 30 to be welded. At the same time, the second electrode cap 20 with a large fitting area helps to improve the stability of the molten core. The method of the present invention also provides guidance for subsequent production and maintenance, avoiding welding defects (such as splashing, cracks and unfused defects) caused by different material properties or thicknesses.

[0056] In summary, the present invention provides a spot welding electrode structure, a resistance welding machine, and a method for welding a cavity and a plate. The spot welding electrode structure proposed in the present invention realizes efficient welding of a plate 30 to be welded and a cavity 40 to be welded by setting a first electrode cap 10 and a second electrode cap 20 to cooperate with each other; by setting a receiving cavity 21 inside the second electrode cap 20, at least a part of the cavity 40 to be welded is set in the receiving cavity 21, and cooperates with the inner wall of the receiving cavity 21, so that the spot welding electrode structure proposed in the present invention can be applied not only to flat plate structures with smooth and uniform welding surfaces, but also to plates and cavities with relatively complex external shapes. For welding, the setting of the accommodating cavity 21 can ensure that a larger welding current is transmitted to the welding surface through the internal cavity of the cavity body, thereby ensuring that the resistance welding machine using the spot welding electrode structure proposed in the present invention has high welding quality for the cavity body and the plate with a relatively complex external shape, and can effectively meet the modern industrial demand for the welding and forming of aluminum alloy cavities and plates in actual use; the spot welding electrode structure proposed in the present invention has a simple structure and low cost, is easy to assemble and subsequently maintain, and can be combined with the cavity body and plate welding method subsequently, and has the advantages of simple process, low equipment cost, strong applicability, high welding quality, high welding efficiency, etc., and is suitable for large-scale promotion and use.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0059] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0060] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0061] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A spot welding electrode structure, characterized in that: include: A first electrode cap (10) and a second electrode cap (20), wherein the first electrode cap (10) and the second electrode cap (20) are electrically connected to external electrodes respectively; the first electrode cap (10) is used to abut against a plate (30) to be welded, and the second electrode cap (20) has an accommodating cavity (21) inside, and at least a portion of a cavity (40) to be welded is arranged in the accommodating cavity (21) and is limitedly matched with an inner wall of the accommodating cavity (21); wherein, when the plate (30) to be welded and the cavity (40) to be welded need to be welded, the welding surface of the plate (30) to be welded is controlled to abut against the welding surface of the cavity (40) to be welded, and the first electrode cap (10) and the plate (30) to be welded are away from each other. The first electrode cap (10) and the second electrode cap (20) are connected to each other by a current through the plate (30) to be welded and the cavity (40) to be welded, and the bottom wall of the accommodating cavity (21) of the second electrode cap (20) is connected to the side of the cavity (40) to be welded away from the welding surface, and the side wall of the accommodating cavity (21) is matched with the outer periphery of the cavity (40) to be welded, and the first electrode cap (10) and the second electrode cap (20) jointly apply forces in opposite directions so that the welding surface of the plate (30) to be welded and the welding surface of the cavity (40) to be welded are pressed at a set pressure, and the first electrode cap (10) and the second electrode cap (20) are connected by current through the plate (30) to be welded and the cavity (40) to be welded, so as to weld and fix the plate (30) to be welded and the cavity (40) to be welded.

2. The spot welding electrode structure according to claim 1, characterized in that: The abutting surface of the first electrode cap (10) for abutting against the plate (30) to be welded is a spherical surface or a plane surface; the size of the accommodating cavity (21) of the second electrode cap (20) is adapted to the external size of the cavity (40) to be welded.

3. The spot welding electrode structure according to claim 2, characterized in that: The first electrode cap (10) comprises a connector (11) and a welding head (12); the welding head (12) is arranged on the connector (11); the connector (11) is used for electrically connecting to an external electrode; the connector (11) is a cylindrical structure; the diameter of the cylindrical structure is in the range of 15 mm to 25 mm; the welding head (12) is used for abutting against the plate (30) to be welded.

4. The spot welding electrode structure according to claim 3, characterized in that: When the abutting surface of the welding head (12) used to abut against the plate (30) to be welded is a spherical surface, the arc curvature radius of the spherical surface is in the range of 20 mm to 100 mm; when the abutting surface of the welding head (12) used to abut against the plate (30) to be welded is a plane, the plane is a circular surface, and the diameter of the circular surface is in the range of 4 mm to 8 mm.

5. The spot welding electrode structure according to claim 1, characterized in that: The total contact area between the inner wall of the accommodating cavity (21) and the cavity (40) to be welded is ≥ 1000 mm 2 .

6. The spot welding electrode structure according to claim 1, characterized in that: When the plate (30) to be welded and the cavity (40) to be welded are made of aluminum alloy material, the material used for the first electrode cap (10) and / or the second electrode cap (20) is aluminum oxide copper material.

7. A resistance welding machine, characterized in that: The resistance welding machine comprises the spot welding electrode structure according to any one of claims 1 to 6, and the resistance welding machine also comprises a power supply, a first electrode rod and a second electrode rod, the first electrode rod and the second electrode rod are respectively connected to the power supply through a circuit; the first electrode cap (10) has a first mounting hole, at least a portion of the first electrode rod is located in the first mounting hole, and is interference fit with the first mounting hole; the second electrode cap (20) has a second mounting hole, at least a portion of the second electrode rod is located in the second mounting hole, and is interference fit with the second mounting hole; wherein, when welding the plate (30) to be welded and the cavity (40) to be welded, the first electrode rod, the first electrode cap (10), the plate (30) to be welded, the cavity (40) to be welded, the second electrode cap (20) and the second electrode rod are connected in series to conduct welding current.

8. A method for welding a cavity and a plate, characterized in that: The cavity and plate welding method is applied to the spot welding electrode structure according to any one of claims 1 to 6, and the cavity and plate welding method comprises the following steps: Installation steps: abutting the welding surface of the plate (30) to be welded with the welding surface of the cavity (40) to be welded, controlling the first electrode cap (10) to abut against the side of the plate (30) to be welded away from the welding surface, controlling the bottom wall of the accommodating cavity (21) of the second electrode cap (20) to abut against the side of the cavity (40) to be welded away from the welding surface, and the side wall of the accommodating cavity (21) is limitedly matched with the outer periphery of the cavity (40) to be welded, applying opposite forces to the first electrode cap (10) and the second electrode cap (20), so that the welding surface of the plate (30) to be welded and the welding surface of the cavity (40) to be welded are pressed at a set pressure; Welding step: adjusting the set pressure within the range of 3.0 kN to 5.0 kN, adjusting the current between the first electrode cap (10) and the second electrode cap (20) within the range of 20 kA to 35 kA, and adjusting the power-on time within the range of 100 ms to 300 ms, so as to weld and fix the welding surface of the plate (30) to be welded and the welding surface of the cavity (40) to be welded; Maintaining step: after the welding step is completed, adjusting the set pressure within the range of 1.0 kN to 3.0 kN, and maintaining the set pressure for a time within the range of 100 ms to 300 ms, so as to wait for the molten metal at the welding surface to completely solidify; Release step: after the maintenance step is completed, the first electrode cap (10) and / or the second electrode cap (20) are adjusted to release the set pressure and complete the welding of the plate (30) to be welded and the cavity (40) to be welded.

9. The method for welding a cavity and a plate according to claim 8, characterized in that: Between the installation step and the welding step, the cavity and plate welding method further comprises a preheating step: adjusting the set pressure within the range of 1.0 kN to 3.0 kN, adjusting the current between the first electrode cap (10) and the second electrode cap (20) within the range of 10 kA to 20 kA, and adjusting the power-on time within the range of 10 ms to 100 ms, so as to preheat the plate (30) to be welded and the cavity (40) to be welded.

10. The method for welding a cavity and a plate according to claim 8, characterized in that: The plate (30) to be welded is an aluminum alloy plate with a thickness in the range of 1.0 mm to 2.0 mm; the cavity (40) to be welded is an aluminum alloy cavity with a wall thickness in the range of 1.0 mm to 5.0 mm.

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