Electrode assembly, welding apparatus and welding method

Abstract

The invention relates to an electrode assembly, welding equipment and a welding method.The electrode assembly is used for being electrically connected with a power supply device of the welding equipment to achieve welding of a first to-be-welded workpiece and a second to-be-welded workpiece, the electrode assembly comprises a heating part, and the heating part can receive power supplied by the power supply device to generate heat; and the heating piece is used for transferring heat generated by the heating piece to the first to-be-welded workpiece and the second to-be-welded workpiece, so that the first to-be-welded workpiece and the second to-be-welded workpiece are welded together. According to the invention, the heating piece is electrified to generate resistance heat, and then the to-be-welded workpiece is heated by the heating piece, so that the local part of the to-be-welded workpiece is heated to a molten or plastic state, and further welding is realized, and therefore, even workpieces (such as workpieces made of copper, silver and the like) with relatively low resistivity can also realize resistance spot welding connection through the resistance spot welding device.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding, and in particular relates to an electrode assembly, welding equipment and a welding method. Background Art

[0002] like Figure 1 As shown, when the welding equipment welds the first workpiece to be welded ① and the second workpiece to be welded ② together by resistance spot welding, it is necessary to first stack the two workpieces to be welded together, and use the two electrodes ③ of the welding equipment to press the two workpieces to be welded from both sides respectively, and then energize the two electrodes ③. At this time, the two electrodes ③ are electrically connected through the first workpiece to be welded ① and the second workpiece to be welded ② to form a loop, so that the current can flow through the first workpiece to be welded ① and the second workpiece to be welded ②, and then the resistance heat generated on the contact surface and adjacent areas of the first workpiece to be welded ① and the second workpiece to be welded ② can locally heat the first workpiece to be welded ① and the second workpiece to be welded ② to a molten or plastic state through the resistance heat, so that the two are connected together.

[0003] In order to heat the first workpiece ① and the second workpiece ② to a molten or plastic state, the first workpiece ① and the second workpiece ② need to generate a large amount of resistance heat, which requires the first workpiece ① and the second workpiece ② to have a large resistance. It is difficult to connect two workpieces with a small resistivity (such as workpieces made of copper, silver, etc.) by resistance spot welding. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to solve the problem that two workpieces to be welded with relatively small resistivity are difficult to connect by resistance spot welding, and to provide an electrode assembly, welding equipment and welding method.

[0005] In order to solve the above problems, on the one hand, the present invention provides an electrode assembly for electrically connecting a power supply device of a welding device to achieve welding of a first workpiece to be welded and a second workpiece to be welded, the electrode assembly comprising a heating element, the heating element being able to receive power from the power supply device to generate heat; the heating element being used to transfer the heat generated by itself to the first workpiece to be welded and the second workpiece to be welded, so that the first workpiece to be welded and the second workpiece to be welded together.

[0006] Optionally, the electrode assembly further includes a thermal insulation connector, one end of which is connected to the heating element, and the other end of which is used to connect to the power supply device.

[0007] Optionally, a mounting hole is provided at one end of the heating element, and the thermal insulation connecting element is installed in the mounting hole.

[0008] Optionally, along the axial direction of the mounting hole, the heating element includes a mounting portion, a main body portion and a contact portion which are connected in sequence, the mounting hole passes through the mounting portion, and the contact portion is used to contact the workpiece to be welded; along the direction from the main body portion to the contact portion, the cross-sectional radius of the contact portion gradually decreases; along the axial direction of the mounting hole, the length of the main body portion is 15mm-20mm.

[0009] Optionally, the thermal insulation connecting element is detachably connected to the heating element.

[0010] Optionally, a connecting hole is provided on the thermal insulation connecting piece, and a cooling system is installed in the connecting hole.

[0011] Optionally, the connection hole penetrates to the surface of the thermal insulation connector close to the heating element.

[0012] Optionally, the material of the heating element includes at least one of tungsten and molybdenum.

[0013] In order to solve the above problems, on the other hand, the present invention provides a welding device, including a power supply device and an electrode assembly as described in any one of the above, wherein the electrode assembly is electrically connected to the power supply device.

[0014] Optionally, the welding equipment includes two electrode assemblies, which are respectively a first electrode assembly and a second electrode assembly; the first electrode assembly, the first workpiece to be welded, the second workpiece to be welded and the second electrode assembly are arranged in sequence; the first electrode assembly and the second electrode assembly are arranged opposite to each other.

[0015] Optionally, the melting point of the heating element of the first electrode assembly is higher than the melting point of the first workpiece to be welded, and the melting point of the heating element of the first electrode assembly is higher than the melting point of the second workpiece to be welded; the melting point of the heating element of the second electrode assembly is higher than the melting point of the first workpiece to be welded, and the melting point of the heating element of the second electrode assembly is higher than the melting point of the second workpiece to be welded.

[0016] Optionally, the resistance of the heating element of the first electrode assembly is greater than the resistance of the first workpiece to be welded, and the resistance of the heating element of the first electrode assembly is greater than the resistance of the second workpiece to be welded; the resistance of the heating element of the second electrode assembly is greater than the resistance of the first workpiece to be welded, and the resistance of the heating element of the second electrode assembly is greater than the resistance of the second workpiece to be welded.

[0017] In order to solve the above problems, the present invention also provides a welding method, comprising: using an electrode assembly to press against a first workpiece to be welded and a second workpiece to be welded that are stacked together; energizing a heating element of the electrode assembly to enable the heating element to generate heat to heat the first workpiece to be welded and the second workpiece to be welded, so that the first workpiece to be welded and the second workpiece to be welded are welded together.

[0018] In the electrode assembly, welding equipment and welding method provided in the embodiments of the present invention, the heating element is energized to generate resistance heat, and then the workpiece to be welded is heated by the heating element, so that the workpiece to be welded is locally heated to a molten or plastic state, thereby achieving welding. Compared with the prior art, this embodiment can achieve resistance spot welding without the workpiece to be welded generating resistance heat, so that even workpieces with a relatively low resistivity (such as workpieces made of copper, silver, etc.) can be connected by resistance spot welding through this embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the state of resistance spot welding in the prior art;

[0020] Figure 2 It is a schematic diagram of the state of resistance spot welding provided by one embodiment of the present invention.

[0021] The reference numerals in the specification are as follows:

[0022] 100, welding equipment; 200, first workpiece to be welded; 300, second workpiece to be welded;

[0023] 10. electrode assembly; 20. cooling system;

[0024] 1. Heating element; 1a. First heating element; 1b. Second heating element; 11. Mounting hole; 12. Mounting portion; 13. Main body; 14. Contact portion;

[0025] 2. Thermal insulation connector; 21. Connecting hole. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] like Figure 2As shown, in one embodiment, the welding device 100 is used to realize the welding of the first workpiece 200 to be welded and the second workpiece 300 to be welded. The welding device 100 includes a power supply device and an electrode assembly 10, wherein the power supply device is electrically connected to the electrode assembly 10. When working, the electrode assembly 10 is used to contact the workpiece to be welded, and the power supply device can supply power to the electrode assembly 10, so that the electrode assembly 10 can be used for welding. In addition, the welding device 100 is mainly used to perform resistance spot welding on the workpieces to be welded. When working, the first workpiece 200 to be welded and the second workpiece 300 to be welded are stacked together, and the electrode assembly 10 presses the first workpiece 200 to be welded and the second workpiece 300 to be welded together.

[0028] like Figure 2 As shown, the welding device 100 generally includes two electrode assemblies 10, which are a first electrode assembly 10a and a second electrode assembly 10b. When working, the first electrode assembly 10a and the second electrode assembly 10b clamp and press two workpieces to be welded.

[0029] like Figure 2 As shown, in one embodiment, the electrode assembly 10 includes a heating element 1, which can receive power from a power supply device to generate heat. When working, the heating element 1 is used to transfer the heat generated by itself to the first workpiece 200 to be welded and the second workpiece 300 to be welded, so that the first workpiece 200 to be welded and the second workpiece 300 to be welded are welded together.

[0030] That is, in this embodiment, the heating element 1 is energized to generate resistance heat, and then the workpiece to be welded is heated by the heating element 1, so that the part of the workpiece to be welded is heated to a molten or plastic state, thereby achieving welding. In the prior art, the workpiece to be welded is energized to generate resistance heat by the workpiece to be welded, thereby heating the part of the workpiece to be welded to a molten or plastic state. Compared with the prior art, the present embodiment can achieve resistance spot welding without the workpiece to be welded generating resistance heat, so that even workpieces with a relatively low resistivity (such as workpieces made of copper, silver, etc.) can be connected by resistance spot welding through the equipment of this embodiment.

[0031] like Figure 2 As shown, in one embodiment, the electrode assembly 10 also includes a thermal insulation connector 2, one end of the thermal insulation connector 2 is connected to the heating element 1, and the other end of the thermal insulation connector 2 is used to connect the power supply device. The thermal insulation connector 2 is used to electrically connect the heating element 1 to the power supply device and to provide thermal insulation to prevent the heat of the heating element 1 from being transferred to the power supply device.

[0032] The heat-insulating connector 2 may be a metal part, and a connection structure is provided on the heat-insulating connector 2 to install a cooling system 20. The cooling system 20 can cool the heat-insulating connector 2, thereby preventing the heat of the heating element 1 from being transferred to the power supply device through the heat-insulating connector 2, thereby achieving heat insulation. Of course, in other embodiments, the heat-insulating connector 2 may also be made of a heat-insulating conductive material.

[0033] like Figure 2 As shown, in one embodiment, the connection structure is a connection hole 21 provided on the heat-insulating connection member 2, and the connection hole 21 is used to install the cooling system 20. The cooling system 20 may be a liquid cooling system.

[0034] In one embodiment, the connection hole 21 penetrates to the surface of the thermal insulation connector 2 close to the heating element 1, so that the cooling system 20 can be installed at a position where the thermal insulation connector 2 is closer to the heating element 1 to improve the cooling effect on the thermal insulation connector 2 and avoid softening of the connection area between the thermal insulation connector 2 and the heating element 1.

[0035] In one embodiment, the heat insulating connector 2 is detachably connected to the heating element 1. When the heating element 1 is damaged, only the heating element 1 needs to be replaced, thereby reducing the use cost.

[0036] In one embodiment, the heat-insulating connector 2 can be an electrode rod, and the heating element 1 can be an electrode cap. The heat-insulating connector 2 can use an existing electrode rod, and the heating element 1 is an electrode cap made of special materials to generate a lot of heat after power is turned on.

[0037] In one embodiment, the material of the heating element 1 includes at least one of tungsten and molybdenum. The material of the heating element 1 can be a single metal or an alloy. In addition, in other embodiments, the heating element 1 can also be made of non-metallic materials.

[0038] like Figure 2 As shown, in one embodiment, a mounting hole 11 is provided at one end of the heating element 1, and the heat-insulating connector 2 is installed in the mounting hole 11. The heat-insulating connector 2 and the mounting hole 11 may be interference fit. In addition, the heat-insulating connector 2 and the heating element 1 may also be matched in other ways, wherein the matching method of the heat-insulating connector 2 and the heating element 1 may be the same as the matching method of the electrode rod and the electrode cap in the prior art.

[0039] like Figure 2As shown, in one embodiment, along the axial direction of the mounting hole 11, the heating element 1 includes a mounting portion 12, a main body portion 13 and a contact portion 14 connected in sequence, the mounting hole 11 passes through the mounting portion 12, and the contact portion 14 is used to contact the workpiece to be welded; along the direction from the main body portion 13 to the contact portion 14, the cross-sectional radius of the contact portion 14 gradually decreases; along the axial direction of the mounting hole 11, the length L of the main body portion 13 is 15mm-20mm. This arrangement can increase the distance between the workpiece to be welded and the cooling system 20, and improve the heating effect of the heating element 1 on the workpiece to be welded. Preferably, the length of the main body portion 13 is 18mm.

[0040] The contact portion 14 may be a hemispherical structure, a frustum structure, a pyramid structure, or the like.

[0041] The embodiment of the present invention further provides a welding method, and the welding device 100 achieves welding of the workpiece to be welded by the welding method. The welding method includes:

[0042] Step S1, use the electrode assembly 10 to press the first workpiece 200 and the second workpiece 300 to be welded that are stacked together to make the first workpiece 200 and the second workpiece 300 to be welded contact each other; Step S2, power on the heating element 1 of the electrode assembly 10 to make the heating element 1 generate heat to heat the first workpiece 200 and the second workpiece 300 to be welded, so that the first workpiece 200 and the second workpiece 300 to be welded are welded together.

[0043] like Figure 2 As shown, when the first workpiece to be welded 200 and the second workpiece to be welded 300 are welded by the welding equipment 100, the first electrode assembly 10a, the first workpiece to be welded 200, the second workpiece to be welded 300 and the second electrode assembly 10b are arranged in sequence; the first workpiece to be welded 200 and the second workpiece to be welded 300 are clamped between the first electrode assembly 10a and the second electrode assembly 10b; in addition, the first electrode assembly 10a and the second electrode assembly 10b are arranged opposite to each other.

[0044] The relative arrangement of the first electrode assembly 10a and the second electrode assembly 10b means that the orthographic projection of the area where the first electrode assembly 10a contacts the first workpiece 200 to be welded on the surface of the second workpiece 300 to be welded away from the first workpiece 200 to be welded overlaps at least a part of the area of ​​the second workpiece 300 to be welded for contacting the second electrode assembly 10b. In addition, the heating element 1 of the first electrode assembly 10a is defined as the first heating element 1a, and the heating element 1 of the second electrode assembly 10b is defined as the second heating element 1b. The first heating element 1a contacts the first workpiece 200 to be welded, thereby realizing the contact between the first electrode assembly 10a and the first workpiece 200 to be welded; the second heating element 1b contacts the second workpiece 300 to be welded, thereby realizing the contact between the second electrode assembly 10b and the second workpiece 300 to be welded.

[0045] In addition, during operation, the first electrode assembly 10a contacts the first workpiece to be welded 200 to achieve electrical connection, the second electrode assembly 10b contacts the second workpiece to be welded 300 to achieve electrical connection, and the first workpiece to be welded 200 and the second workpiece to be welded 300 contact to achieve electrical connection, so that the power supply device, the first electrode assembly 10a and the second electrode assembly 10b are connected through the two workpieces to be welded to form a circuit.

[0046] Before step S1, it also includes selecting a suitable heating element 1 to connect with the heat-insulating connector 2, wherein the selection of the heating element 1 is mainly to select the structural shapes of the first heating element 1a and the second heating element 1b, for example, according to different needs, select a heating element 1 with a different shape of the contact portion 14. In addition, the selection of the heating element 1 can refer to the method of selecting a suitable electrode cap during resistance spot welding in the prior art.

[0047] Before step S2, that is, before the heating element 1 is powered on, parameters such as welding power need to be set. These parameters can also be set according to the parameter setting rules for resistance spot welding in the prior art.

[0048] In one embodiment, the melting point of the first heating element 1a is higher than the melting point of the first workpiece 200 to be welded, and the melting point of the first heating element 1a is higher than the melting point of the second workpiece 300 to be welded; the melting point of the second heating element 1b is higher than the melting point of the first workpiece 200 to be welded, and the melting point of the second heating element 1b is higher than the melting point of the second workpiece 300 to be welded. In this way, the heating element 1 can be prevented from being damaged during the welding process. In addition, the melting point of the first heating element 1a and the melting point of the second heating element 1b can be the same, wherein the first heating element 1a and the second heating element 1b can be made of the same material.

[0049] In one embodiment, the resistance of the first heating element 1a is greater than the resistance of the first workpiece 200 to be welded, and the resistance of the first heating element 1a is greater than the resistance of the second workpiece 300 to be welded; the resistance of the second heating element 1b is greater than the resistance of the first workpiece 200 to be welded, and the resistance of the second heating element 1b is greater than the resistance of the second workpiece 300 to be welded. The resistances of the first heating element 1a and the second heating element 1b may be the same, wherein the materials and structures of the two may be the same.

[0050] In addition, the resistance of the first workpiece 200 to be welded refers to the resistance of the portion of the first workpiece 200 to be welded that is opposite to the first electrode assembly 10 a and the second electrode assembly 10 b .

[0051] Assuming that the first area of ​​the first surface of the first workpiece 200 to be welded (i.e., the surface of the first workpiece 200 to be welded facing away from the second workpiece 300 to be welded) is in contact with the first heating element 1a, then the partial structure of the first workpiece 200 to be welded whose orthographic projection on the first surface can overlap with the first area is the partial structure of the first workpiece 200 to be welded that is opposite to the first electrode assembly 10a (this partial structure is defined as the first partial structure).

[0052] In addition, the part of the structure where the orthographic projection of the second heating element 1b in the first area overlaps with the projection of the first part in the first area (this part of the structure is defined as the second part of the structure), wherein the resistance of the second part of the structure is the resistance of the first workpiece to be welded 200. Usually, the second part of the structure is the first part of the structure. Of course, in some scenarios, the second part of the structure may also be just a part of the first part of the structure.

[0053] The resistance of the second workpiece 300 to be welded refers to the resistance of the portion of the second workpiece 300 to be welded that is opposite to the first electrode assembly 10 a and the second electrode assembly 10 b .

[0054] Assuming that the second area of ​​the second surface of the second workpiece to be welded 300 (i.e., the surface of the second workpiece to be welded 300 facing away from the first workpiece to be welded 200) is in contact with the second heating element 1b, then the partial structure of the second workpiece to be welded 300 whose orthographic projection on the second surface can overlap with the second area is the partial structure of the second workpiece to be welded 300 that is opposite to the first electrode assembly 10a (this partial structure is defined as the third partial structure).

[0055] The part of the structure where the orthographic projection of the first heating element 1a in the second area overlaps with the orthographic projection of the third part in the second area (this part of the structure is defined as the fourth part of the structure), wherein the resistance of the fourth part of the structure is the resistance of the second workpiece to be welded 300. Usually, the fourth part of the structure is the third part of the structure. Of course, in some scenarios, the fourth part of the structure may also be just a part of the third part of the structure.

[0056] In addition, during the welding process, the current flows through seven series-connected resistors between the first heating element 1a and the second heating element 1b, which are the resistance R1 of the first heating element 1a, the contact resistance R2 between the first heating element 1a and the first workpiece to be welded 200, the resistance R3 of the first workpiece to be welded 200, the contact resistance R4 between the first workpiece to be welded 200 and the second workpiece to be welded 300, the resistance R5 of the second workpiece to be welded 300, the contact resistance R6 between the second heating element 1b and the second workpiece to be welded 300, and the resistance R7 of the second heating element 1b, wherein R1>R2, R1>R3, R1>R4, R1>R5, R1>R6, R7>R2, R7>R3, R7>R4, R7>R5, R7>R6, R2>R3, R6>R5.

[0057] After power is turned on, R1 and R7 are the largest, so the first heating element 1a and the second heating element 1b generate the most heat. Although R2 and R6 are also large, they will disappear after power is turned on for a period of time. Moreover, the area where the first workpiece 200 to be welded contacts the first heating element 1a is located on the outside, and the heat dissipation is faster, resulting in less heat accumulation, while the area where the first workpiece 200 to be welded contacts the second workpiece 300 to be welded is located on the inside, and the heat dissipation is slower, so the heat accumulation is more. Finally, the area where the first workpiece 200 to be welded contacts the second workpiece 300 to be welded is first heated to a molten or plastic state, and similarly, the area where the second workpiece 300 to be welded contacts the first workpiece 200 to be welded is first heated to a molten or plastic state. When the first workpiece 200 to be welded and the second workpiece 300 to be welded are welded together, the first workpiece 200 to be welded can be prevented from sticking to the first heating element 1a, and the second workpiece 300 to be welded can be prevented from sticking to the second heating element 1b.

[0058] It should be understood that the above-mentioned related designs can also be replaced by other methods, such as:

[0059] In other embodiments, only one of the two electrode assemblies 10 of the welding device 100 has the above-mentioned heating element 1, and the electrode rod of the other one is connected to a common electrode cap.

[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrode assembly, used for electrically connecting a power supply device of a welding device to achieve welding of a first workpiece to be welded and a second workpiece to be welded, characterized in that: The electrode assembly includes a heating element, and the heating element can receive power from the power supply device to generate heat; The heating element is used to transfer the heat generated by the heating element to the first workpiece to be welded and the second workpiece to be welded, so that the first workpiece to be welded and the second workpiece to be welded together.

2. The electrode assembly according to claim 1, characterized in that: The electrode assembly further comprises a heat-insulating connector, one end of which is connected to the heating element, and the other end of which is used to connect to the power supply device.

3. The electrode assembly according to claim 2, characterized in that: A mounting hole is provided at one end of the heating element, and the heat-insulating connecting element is installed in the mounting hole.

4. The electrode assembly according to claim 3, characterized in that: Along the axial direction of the mounting hole, the heating element comprises a mounting portion, a main body portion and a contact portion which are connected in sequence, the mounting hole passes through the mounting portion, and the contact portion is used to contact with a workpiece to be welded; Along the direction from the main body to the contact portion, the cross-sectional radius of the contact portion gradually decreases; Along the axial direction of the mounting hole, the length of the main body is 15 mm-20 mm.

5. The electrode assembly according to claim 2, characterized in that: The heat-insulating connecting element is detachably connected to the heating element.

6. The electrode assembly according to claim 2, characterized in that: The heat-insulating connector is provided with a connecting hole, and the connecting hole is used for installing a cooling system.

7. The electrode assembly according to claim 6, characterized in that: The connection hole penetrates to the surface of the heat-insulating connection member close to the heating member.

8. The electrode assembly according to claim 1, characterized in that: The material of the heating element includes at least one of tungsten and molybdenum.

9. A welding device, characterized in that: It comprises a power supply device and the electrode assembly according to any one of claims 1 to 8, wherein the electrode assembly is electrically connected to the power supply device.

10. The welding device according to claim 9, characterized in that The welding device comprises two electrode assemblies, wherein the two electrode assemblies are respectively a first electrode assembly and a second electrode assembly; The first electrode assembly, the first workpiece to be welded, the second workpiece to be welded, and the second electrode assembly are arranged in sequence; The first electrode assembly is arranged opposite to the second electrode assembly.

11. The welding device according to claim 10, characterized in that The melting point of the heating element of the first electrode assembly is higher than the melting point of the first workpiece to be welded, and the melting point of the heating element of the first electrode assembly is higher than the melting point of the second workpiece to be welded; The melting point of the heating element of the second electrode assembly is higher than the melting point of the first workpiece to be welded, and the melting point of the heating element of the second electrode assembly is higher than the melting point of the second workpiece to be welded.

12. The welding device according to claim 10, characterized in that The resistance of the heating element of the first electrode assembly is greater than the resistance of the first workpiece to be welded, and the resistance of the heating element of the first electrode assembly is greater than the resistance of the second workpiece to be welded; The resistance of the heating element of the second electrode assembly is greater than the resistance of the first workpiece to be welded, and the resistance of the heating element of the second electrode assembly is greater than the resistance of the second workpiece to be welded.

13. A welding method, characterized in that: include: Using the electrode assembly to press the first workpiece to be welded and the second workpiece to be welded which are stacked together; The heating element of the electrode assembly is powered on to generate heat to heat the first workpiece to be welded and the second workpiece to be welded, so that the first workpiece to be welded and the second workpiece to be welded are welded together.

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