Electrode cap and welding device

Abstract

The embodiment of the utility model provides an electrode cap and a welding device. The electrode cap comprises an inner electrode layer, at least two outer electrode layers and an insulating part; the outer electrode layers are annularly arranged on the periphery of the inner electrode layer, and the at least two outer electrode layers are arranged at intervals in the radial direction of the electrode cap; the insulating part is arranged between the adjacent outer electrode layers, and the insulating part is arranged between one outer electrode layer closest to the inner electrode layer and the inner electrode layer.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of welding technology, and more specifically, relate to an electrode cap and a welding device. Background Art

[0002] With the rapid development of my country's automobile industry, more and more lightweight materials such as aluminum alloy are used to achieve automobile safety and reduce energy consumption. For example, the four doors and two covers in the body structure are the outer covering parts of the automobile body, and the appearance quality and matching clearance need to be guaranteed.

[0003] In the production process of the vehicle body exterior covering parts, after the inner and outer panels are hemmed, they are usually fixed by a reasonable welding method to avoid the inner and outer panels from moving and causing dimensional deviation. However, aluminum alloy has a low melting point, low hardness, and a large expansion coefficient. In addition, there is a dense oxide film on the surface. The use of traditional resistance spot welding is prone to indentation, uneven surface and other appearance quality problems, especially indentation and deformation near the welding point, which directly affects the appearance quality of the whole vehicle.

[0004] In view of this, it is necessary to provide a new technical solution to solve the above technical problems. Utility Model Content

[0005] The purpose of this application is to provide a new technical solution for an electrode cap and a welding device.

[0006] In a first aspect, an embodiment of the present application provides an electrode cap. The electrode cap comprises: an inner electrode layer, at least two outer electrode layers and an insulating portion;

[0007] The outer electrode layer is arranged around the outer periphery of the inner electrode layer, and at least two outer electrode layers are arranged at intervals in the radial direction of the electrode cap;

[0008] The insulating portion is disposed between adjacent outer electrode layers, and the insulating portion is disposed between an outer electrode layer closest to the inner electrode layer and the inner electrode layer.

[0009] Optionally, an end surface of the insulating portion, an end surface of the inner electrode layer, and an end surface of the outer electrode layer are flush.

[0010] Optionally, the thickness of the insulating portion is d1, the diameter of the inner electrode layer is d2, and d2 is 1 to 1.5 times of d1.

[0011] Optionally, at least two of the outer electrode layers include a first electrode portion and a second electrode portion, the axial dimension of the first electrode portion is smaller than the axial dimension of the second electrode portion, and the second electrode portion is closer to the inner electrode layer than the first electrode portion.

[0012] Optionally, the insulating part is made of ceramic or plastic.

[0013] In a second aspect, an embodiment of the present application further provides a welding device. The welding device comprises the electrode cap, the inner electrode rod and the outer electrode rod as described in the first aspect, wherein the inner electrode rod and the outer electrode rod are arranged in a nested manner;

[0014] One end of the outer electrode rod is connected to at least two of the outer electrode layers;

[0015] One end of the inner electrode rod is connected to the inner electrode layer.

[0016] Optionally, the inner electrode rod comprises an electrode rod body, an electrode rod sleeve, an elastic component and an insulating gasket;

[0017] The outer end surface of the electrode rod sleeve is connected to the inner electrode layer;

[0018] The insulating gasket is arranged on the inner end surface of the electrode rod sleeve, at least part of the electrode rod body is located in the electrode rod sleeve, one end of the elastic component is connected to the electrode rod body, and the other end is connected to the insulating gasket.

[0019] Optionally, at least two of the outer electrode layers include a first electrode portion and a second electrode portion, the axial dimension of the first electrode portion is smaller than the axial dimension of the second electrode portion, and the second electrode portion is closer to the inner electrode layer than the first electrode portion;

[0020] One end of the outer electrode rod is connected to the first electrode portion.

[0021] Optionally, the applied electrode pressure range of the welding device is 2.5KN to 5KN; and / or the current range of the welding device is 20KA to 45KA.

[0022] Optionally, the welding device further comprises a welding platform, and the welding platform is used to support the parts to be welded.

[0023] According to an embodiment of the present application, an electrode cap is provided, which includes an inner electrode layer, multiple outer electrode layers and an insulating part arranged between adjacent electrode layers. The multiple insulating layers are beneficial to breaking the oxide film on the surface of the aluminum alloy material, improving the welding stability and enhancing the appearance quality of the welded parts.

[0024] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0026] Figure 1 Shown is a schematic structural diagram of a welding device provided in an embodiment of the present application.

[0027] Figure 2 Shown is a schematic structural diagram of an electrode cap provided in an embodiment of the present application.

[0028] Figure 3 Shown is a top view of the electrode cap provided in an embodiment of the present application.

[0029] Figure 4 The figure shows a schematic diagram of the structure of the welding device provided in the embodiment of the present application for welding a part to be processed. Figure 1

[0030] Figure 5 The figure shows a schematic diagram of the structure of the welding device provided in the embodiment of the present application for welding a part to be processed. Figure 2 .

[0031] Description of reference numerals:

[0032] 1. Inner electrode layer;

[0033] 2. external electrode layer; 21. first external electrode layer; 22. second external electrode layer; 23. first electrode portion; 24. second electrode portion;

[0034] 3. Insulation part;

[0035] 4. inner electrode rod; 41. electrode rod body; 42. electrode rod sleeve; 43. elastic component; 44. insulating gasket;

[0036] 5. External electrode rod;

[0037] 61. Inner panel; 62. Outer panel;

[0038] 7. Welding platform;

[0039] 8. Molten core. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0041] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0042] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0043] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0044] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0045] A first aspect of an embodiment of the present application provides an electrode cap. The improved electrode cap is applied to a single-sided spot welding machine to improve welding stability and enhance the appearance quality of the welded parts during welding.

[0046] Reference Figure 1 The electrode cap comprises: an inner electrode layer 1, at least two outer electrode layers 2 and an insulating portion 3;

[0047] The outer electrode layer 2 is arranged around the outer periphery of the inner electrode layer 1, and at least two outer electrode layers 2 are arranged at intervals in the radial direction of the electrode cap;

[0048] The insulating portion 3 is disposed between adjacent outer electrode layers 2 , and the insulating portion 3 is disposed between an outer electrode layer 2 closest to the inner electrode layer 1 and the inner electrode layer 1 .

[0049] In the embodiment of the present application, according to the positional relationship between the inner electrode layer 1 and the outer electrode layer 2 in the electrode cap (the inner electrode layer 1 and the outer electrode layer 2 are located on the same side), it can be clearly seen that the electrode cap is mainly used in a welding device for single-sided spot welding, for example, the electrode cap can be used in a single-sided spot welding machine.

[0050] Specifically, refer to Figure 1-Figure 3 The electrode cap includes an inner electrode layer 1 and an outer electrode layer 2. For example, the inner electrode layer 1 may be a positive electrode, and the outer electrode layer 2 may be a negative electrode.

[0051] The electrode cap includes an inner electrode layer 1, and the inner electrode layer 1 is provided as a single layer, thereby ensuring the reliability of welding of the electrode cap during the welding process.

[0052] The electrode cap includes at least two outer electrode layers 2, which are arranged around the outer periphery of the inner electrode layer 1, and at least two outer electrode layers 2 are arranged at intervals in the radial direction of the electrode cap, so that the electrode cap is a multi-layer design. Figure 3From the top view of the electrode cap, it can be seen that the end face of the electrode cap is a multi-ring structure. For example, the electrode cap includes a first outer electrode layer 21 and a second outer electrode layer 22, the second outer electrode layer 22 is sleeved outside the inner electrode layer 1, and the first outer electrode layer 21 is sleeved outside the second outer electrode layer 22, so that the electrode cap is a multi-layer structure.

[0053] An insulating portion 3 is provided between adjacent inner electrode layers 1 and outer electrode layers 2, and an insulating portion 3 is also provided between two adjacent outer electrode layers 2, to ensure that no current short circuit occurs between the electrode layers. The inner electrode layer 1, multiple outer electrode layers 2, and insulating portions 3 between adjacent electrode layers in the electrode cap form a single-sided spot welding electrode structure similar to a "multi-ring type".

[0054] In order to prevent current from flowing directly between different electrode layers, thereby maintaining the independence and accuracy of electrical signals, an insulating portion 3 is provided between adjacent electrode layers. Since the electrode cap includes an inner electrode layer 1 and multiple outer electrode layers 2, the electrode cap also includes multiple layers of insulating portions 3 in its overall structure.

[0055] In a welding device in which the electrode cap is used for single-sided spot welding, the material of the insulating part 3 is usually harder than the welding material (such as aluminum alloy). When the electrode cap includes a multi-layer insulating part 3, the multi-layer insulating part 3 is beneficial for breaking the oxide film on the surface of the aluminum alloy material and improving welding stability and consistency.

[0056] In addition, the electrode cap is used in a single-sided spot welding device, which is mainly used for repair welding of the workpiece to be welded. During welding, most of the heat input of the welding device is concentrated on one side of the electrode cap for single-sided spot welding, and the heat input on the appearance surface of the workpiece to be welded accounts for only a small part, and the heat impact on the appearance surface of the workpiece to be welded is relatively small. Therefore, the appearance surface of the workpiece to be welded is less deformed during welding, which is conducive to improving the appearance quality of the workpiece to be welded.

[0057] Therefore, in an embodiment of the present application, an electrode cap is provided, which includes an inner electrode layer 1, a plurality of outer electrode layers 2, and an insulating portion 3 arranged between adjacent electrode layers. The plurality of insulating layers are beneficial for breaking the oxide film on the surface of the aluminum alloy material, improving the welding stability and enhancing the appearance quality of the welded parts.

[0058] In one embodiment, referring to Figure 2 , the end surface of the insulating portion 3, the end surface of the inner electrode layer 1 and the end surface of the outer electrode layer are flush.

[0059] In this embodiment, the end surface of the insulating portion 3, the end surface of the inner electrode layer 1 and the end surface of the outer electrode layer are flush, wherein the end surface refers to the surface that contacts the workpiece to be welded during the welding process. In this way, the surface of the insulating portion 3 that contacts the workpiece to be welded, the surface of the inner electrode layer 1 that contacts the workpiece to be welded, and the surface of the outer electrode layer that contacts the workpiece to be welded are flush, and the end surface of the electrode cap is a planar multi-ring structure.

[0060] When the electrode cap is used in a single-sided spot welding device, during welding, the end face of the electrode cap acts on the workpiece to be welded, and the surface in the insulating portion 3 that contacts the workpiece to be welded, the surface in the inner electrode layer 1 that contacts the workpiece to be welded, and the surface in the outer electrode layer that contacts the workpiece to be welded act on the surface of the workpiece to be welded with substantially the same force, so that the indentation of the end face of the planar ring electrode on the surface of the workpiece to be welded is shallow, and this position does not affect the appearance quality of the welding. Optionally, the indentation of the end face of the planar ring electrode on the surface of the workpiece to be welded can be controlled within 0.1 mm, which is much smaller than the spot welding indentation of existing aluminum alloys (above 0.5 mm).

[0061] In a specific embodiment, the outer electrode layer 2 is made of chromium zirconium copper electrode, and the outer electrode layer 2 is set as the negative electrode. The inner electrode layer 1 is made of high temperature resistant molybdenum electrode, which can withstand a high temperature of 2000°C, and is set as the positive electrode.

[0062] In one embodiment, referring to Figure 2 The thickness of the insulating portion 3 is d1, the diameter of the inner electrode layer 1 is d2, and d2 is 1 to 1.5 times of d1.

[0063] In this embodiment, the dimensional relationship between the insulating portion 3 of the electrode cap and the inner electrode layer 1 is defined, and this dimensional relationship directly affects the performance and safety of the electrode cap.

[0064] The thickness d1 of the insulating portion 3 determines the ability of the electrode cap to prevent current leakage and short circuit, while the diameter d2 of the inner electrode layer 1 is related to the efficiency and stability of electrical signal transmission. If d1 is too small, the insulation effect may be insufficient, which may easily lead to current leakage or short circuit, thereby reducing the safety of the electrode cap. If d2 is too large relative to d1, the path of electrical signal transmission may be too long or dispersed, resulting in signal loss or distortion, affecting the performance of the electrode cap.

[0065] Therefore, setting d2 to 1 to 1.5 times of d1 is a reasonable range, which can ensure sufficient insulation effect and ensure the efficiency and stability of electrical signal transmission. This design allows the electrode cap to maintain high performance while also having high safety.

[0066] In one embodiment, referring to Figure 1 and Figure 2At least two of the outer electrode layers 2 include a first electrode portion 23 and a second electrode portion 24 , the axial dimension of the first electrode portion 23 is smaller than the axial dimension of the second electrode portion 24 , and the second electrode portion 24 is closer to the inner electrode layer 1 than the first electrode portion 23 .

[0067] In this embodiment, at least two outer electrode layers 2 and the insulating portion 3 between at least two outer electrode layers 2 are taken as a whole, and the whole is divided into a first electrode portion 23 and a second electrode portion 24, and the two portions are different in the axial size of the electrode cap, wherein the axial size of the first electrode portion 23 is smaller than that of the second electrode portion 24. In addition, the second electrode portion 24 is closer to the inner electrode layer 1 than the first electrode portion 23.

[0068] Since the second electrode portion 24 is closer to the inner electrode layer 1, it can more effectively form electric field coupling with the inner electrode layer 1 and optimize the electric field distribution, which helps to improve the electrical performance of the electrode cap, such as conductive efficiency and signal quality.

[0069] In addition, dividing the outer electrode layer 2 into two electrode parts of different sizes can reduce the current density of the second electrode part 24 (close to the inner electrode layer 1), which helps to reduce heat generation and electrode wear, thereby increasing the service life of the electrode cap.

[0070] In addition, in a welding device that uses the electrode cap for single-sided spot welding, the outer electrode rod 5 of the welding device is connected to the first electrode portion 23, and the inner electrode rod 4 of the welding device is connected to the inner electrode layer 1. Since the first electrode portion 23 is relatively far away from the inner electrode layer 1, there is a spacing distance between the outer electrode rod 5 and the inner electrode rod 4, and the two will not be close to each other, thereby avoiding accidental contact between the two and causing a short circuit.

[0071] In a specific embodiment, referring to Figure 2 The diameter of the electrode cap is d3, and d3 satisfies: 8mm<d3<20mm.

[0072] In this embodiment, the selection of the diameter range of the electrode cap is generally based on the requirements and limitations of the actual application. A smaller diameter may be suitable for scenarios with smaller hemming or rolling dimensions, while a larger diameter may be suitable for scenarios requiring a larger contact area or a higher current capacity.

[0073] It should be noted that this diameter range is not absolute. In practical applications, it needs to be designed and optimized according to specific circumstances.

[0074] In one embodiment, the insulating part 3 is made of ceramic or plastic.

[0075] In this embodiment, ceramics have the advantages of high melting point, high hardness, high wear resistance, oxidation resistance, etc. These characteristics enable ceramics to effectively prevent current leakage and short circuit in the insulating portion 3 of the electrode cap, ensuring the safety and stability of the electrode cap. Plastics have the advantages of light weight, easy processing, and low cost. Using plastic materials in the insulating portion 3 of the electrode cap can reduce production costs and improve production efficiency. At the same time, some plastic materials also have good insulation properties and high temperature resistance, which can meet the use requirements of the electrode cap under specific working conditions.

[0076] It should be noted that in harsh environments such as high temperature and high pressure, ceramic materials may be more suitable as the insulating material 3; while in some applications with higher cost requirements, plastic materials may be more advantageous.

[0077] It should be noted that the material of the insulating part 3 includes ceramics and plastics but is not limited to ceramics and plastics and may also be other insulating materials.

[0078] Optionally, the melting point of the material of the insulating portion 3 is above 1000° C. to ensure that the insulating material does not melt during single-sided spot welding.

[0079] A second aspect of the present application provides a welding device. Figure 1 , Figure 4 and Figure 5 The welding device includes the electrode cap, inner electrode rod 4 and outer electrode rod 5 mentioned above, and the inner electrode rod 4 and the outer electrode rod 5 are nested; one end of the outer electrode rod 5 is connected to at least two of the outer electrode layers 2; one end of the inner electrode rod 4 is connected to the inner electrode layer 1.

[0080] Specifically, the electrode cap is used in a welding device, and the welding device can realize single-sided spot welding. For example, the welding device is used to weld the hemming or rolling of inner and outer plates. That is, the welding device is usually used as a device for repair welding process.

[0081] The structure of the electrode cap end face (a flat multi-ring structure) combined with the characteristics of single-sided spot welding (heat energy is mainly concentrated on the electrode cap end face during single-sided spot welding, and the appearance surface of the welded part receives less heat input), enables the welding device to weld the welded part with a shallow surface indentation, which does not affect the appearance quality. For example, the welding device can be used to weld the outer cover of a vehicle.

[0082] In this embodiment, the design of the welding device takes into account the effective conduction of current, the independence of electrical signals and the actual requirements of welding work. The nested arrangement of the inner electrode rod 4 and the outer electrode rod 5, as well as the multi-layer structure design of the electrode cap, ensures the stability and reliability of the welding process, while improving the welding efficiency and quality.

[0083] In one embodiment, referring to Figure 1 , Figure 4 and Figure 5 The inner electrode rod 4 includes an electrode rod body 41, an electrode rod sleeve 42, an elastic component 43 and an insulating gasket 44;

[0084] The outer end surface of the electrode rod sleeve 42 is connected to the inner electrode layer 1;

[0085] The insulating gasket 44 is arranged on the inner end surface of the electrode rod sleeve 42 , and at least part of the electrode rod body 41 is located in the electrode rod sleeve 42 . One end of the elastic component 43 is connected to the electrode rod body 41 , and the other end is connected to the insulating gasket 44 .

[0086] In this embodiment, the inner electrode rod 4 includes an electrode plate body, an electrode rod sleeve 42, an elastic component 43 and an insulating gasket 44. The inner electrode layer 1 is connected to the outer end surface of the electrode rod sleeve 42. At least part of the electrode plate body is located in the electrode rod sleeve 42. The electrode plate body is located on one side of the electrode rod sleeve 42 and is connected to the elastic component 43. The other end of the elastic component 43 is connected to the insulating gasket 44. In this way, the elastic component 43 can be prevented from being energized. In addition, under the elastic effect of the elastic component 43, the electrode plate body can ensure that the inner electrode layer 1 and the inner electrode rod 4 sleeve are closely attached to each other, thereby ensuring the path of the welding current.

[0087] The electrode rod body 41 and the electrode rod sleeve 42 must be made of conductive materials, so that during the actual welding process, the electrode rod body 41 can conduct the current to the electrode rod sleeve 42 and then to the inner electrode layer 1, ensuring the conduction of the welding current.

[0088] It should be noted that, during the welding process, in order to ensure the contact reliability between the inner electrode rod 4 and the inner electrode cap, this embodiment provides a preferred structure of the inner electrode rod 4, and those skilled in the art can adjust the structure of the inner electrode rod 4 according to actual needs and in combination with the specific structure of the electrode cap.

[0089] In a specific embodiment, the outer electrode layer 2 and the outer electrode rod 5 are directly connected by threads, or they can be connected in a nested manner to enhance the stability of the connection between the two.

[0090] In one embodiment, referring to Figure 1 and Figure 4 , at least two of the outer electrode layers 2 include a first electrode portion 23 and a second electrode portion 24, the axial dimension of the first electrode portion 23 is smaller than the axial dimension of the second electrode portion 24, and the second electrode portion 24 is closer to the inner electrode layer 1 than the first electrode portion 23;

[0091] One end of the outer electrode rod 5 is connected to the first electrode portion 23 .

[0092] In this embodiment, the outer electrode rod 5 of the welding device is connected to the first electrode portion 23, and the inner electrode rod 4 of the welding device is connected to the inner electrode layer 1. Since the first electrode portion 23 is relatively far away from the inner electrode layer 1, there is a spacing distance between the outer electrode rod 5 and the inner electrode rod 4, and the two are not close to each other, thereby avoiding accidental contact between the two and causing a short circuit.

[0093] In one embodiment, the applied electrode pressure of the welding device is in the range of 2.5 KN to 5 KN; and / or the current of the welding device is in the range of 20 KA to 45 KA.

[0094] In this embodiment, the setting range of the electrode pressure is 2.5KN (kilonewton) to 5KN. The selection of this range is usually based on factors such as the type and thickness of the welding material, the required welding quality, etc. Appropriate electrode pressure can ensure good contact between the electrode and the workpiece, promote uniform distribution of current, and thus obtain a high-quality weld joint.

[0095] In addition, the current range is set from 20KA (kiloamperes) to 45KA. The selection of this range also depends on factors such as the type, thickness, and welding speed of the welding material. A higher current can speed up the welding speed, but it may also cause overheating in the welding area, causing the material to burn through or deform. Therefore, it is necessary to select the appropriate current value according to the specific situation.

[0096] It should be noted that these two parameters (electrode pressure and current) are interrelated during the welding process. In actual operation, the operator needs to reasonably set and adjust these two parameters based on factors such as the characteristics of the welding material, welding requirements, and equipment performance.

[0097] In a specific embodiment, the welding device is used to weld the hemming of the outer covering, and the outer covering includes an inner plate 61 and an outer plate 62. The inner plate 61 and the outer plate 62 are both made of aluminum alloy, the thickness of the outer plate 62 is generally 0.65mm to 1mm, and the thickness of the inner plate 61 is generally above 1mm. The welding device combines the thickness of the inner plate 61 and the outer plate 62, and adopts the above-defined electrode pressure and current, which can achieve the inner and outer plate welding, avoid the misalignment of the inner and outer plates, and ensure the appearance quality of the aluminum alloy outer covering.

[0098] In a specific embodiment, referring to Figure 5 The welding device further comprises a welding platform 7, and the welding platform 7 is used to support the parts to be welded.

[0099] In this embodiment, the welding platform 7 is mainly used to support the workpiece to be welded, ensuring that the workpiece can maintain a stable position during the welding process.

[0100] For example, the welding device is used to weld the outer cover of an aluminum alloy vehicle body, which can significantly improve the indentation and welding deformation problems of the outer cover after spot welding. The outer plate 62 acted upon by the welding platform 7 has basically no indentation, and the outer plate 62 acted upon by the end face of the flat multi-ring electrode has a shallow indentation, which can be controlled within 0.1 mm, and this position does not affect the appearance quality of the welding.

[0101] In a specific embodiment, referring to Figure 5 When the welding device is used to weld the outer covering of the vehicle body, the welding current is 30KA, and the applied electrode pressure range is 4KN. After the end face of the electrode cap presses the inner and outer plate edge structure, the current flows from the inner electrode layer 1 (positive electrode) to the outer electrode layer 2 (negative electrode), and Joule heat is generated through resistance heating, thereby forming a flat or wavy weld core 8.

[0102] The sources of resistance heat mainly lie in three parts. Since the outer plate 62 (0.7 mm) is very thin, after the current flows out from the inner electrode layer 1, a part of it will pass through the contact surface of the inner and outer plates to reach the outer electrode layer 2. This part of the current will generate Joule heat through the contact resistance of the inner and outer plates; another part of the current will pass through the inner plate 62 to reach the outer electrode layer 2. This part of the current density is concentrated at the contact point between the inner electrode layer 1 and the outer plate 62 and its vicinity, which will generate a large amount of resistance heat in this part. This is also the reason why the inner electrode cap chooses a high-temperature resistant molybdenum electrode. Another part of the current is diverted by the outer plate 62 and forms resistance heat through the contact surface of the inner and outer plates. This part of the current is small and the resistance heat generated is limited. The above three parts of resistance heat jointly generate a molten core 8 between the inner and outer plates. The molten core 8 is a flat or wavy molten core 8.

[0103] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0104] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An electrode cap, characterized in that: include: An inner electrode layer (1), at least two outer electrode layers (2) and an insulating portion (3); The outer electrode layer (2) is arranged around the outer periphery of the inner electrode layer (1), and at least two of the outer electrode layers (2) are arranged at intervals in the radial direction of the electrode cap; The insulating portion (3) is provided between adjacent outer electrode layers (2), and the insulating portion (3) is provided between an outer electrode layer (2) closest to the inner electrode layer (1) and the inner electrode layer (1).

2. The electrode cap according to claim 1, characterized in that: The end surface of the insulating portion (3), the end surface of the inner electrode layer (1) and the end surface of the outer electrode layer (2) are flush.

3. The electrode cap according to claim 1, characterized in that: The thickness of the insulating portion (3) is d1, the diameter of the inner electrode layer (1) is d2, and d2 is 1 to 1.5 times of d1.

4. The electrode cap according to claim 1, characterized in that: At least two of the outer electrode layers (2) include a first electrode portion (23) and a second electrode portion (24), wherein the axial dimension of the first electrode portion (23) is smaller than the axial dimension of the second electrode portion (24), and the second electrode portion (24) is closer to the inner electrode layer (1) than the first electrode portion (23).

5. The electrode cap according to claim 1, characterized in that: The insulating part (3) is made of ceramic or plastic.

6. A welding device, characterized in that: The welding device comprises an electrode cap, an inner electrode rod (4) and an outer electrode rod (5) according to any one of claims 1 to 5, wherein the inner electrode rod (4) and the outer electrode rod (5) are arranged in a nested manner; One end of the outer electrode rod (5) is connected to at least two of the outer electrode layers (2); One end of the inner electrode rod (4) is connected to the inner electrode layer (1).

7. The welding device according to claim 6, characterized in that: The inner electrode rod (4) comprises an electrode rod body (41), an electrode rod sleeve (42), an elastic component (43) and an insulating gasket (44); The outer end surface of the electrode rod sleeve (42) is connected to the inner electrode layer (1); The insulating gasket (44) is arranged on the inner end surface of the electrode rod sleeve (42), at least a part of the electrode rod body (41) is located in the electrode rod sleeve (42), one end of the elastic component (43) is connected to the electrode rod body (41), and the other end is connected to the insulating gasket (44).

8. The welding device according to claim 6, characterized in that: At least two of the outer electrode layers (2) include a first electrode portion (23) and a second electrode portion (24), the axial dimension of the first electrode portion (23) is smaller than the axial dimension of the second electrode portion (24), and the second electrode portion (24) is closer to the inner electrode layer (1) than the first electrode portion (23); One end of the outer electrode rod (5) is connected to the first electrode portion (23).

9. The welding device according to claim 6, characterized in that: The applied electrode pressure of the welding device is in the range of 2.5KN to 5KN; and / or The current range of the welding device is 20KA~45KA.

10. The welding device according to claim 6, characterized in that: The welding device further comprises a welding platform (7), wherein the welding platform (7) is used for supporting the parts to be welded.

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