Electric field auxiliary welding tool and welding equipment

Abstract

The utility model provides an electric field auxiliary welding tool which comprises a welding pressure head piece, the welding pressure head piece comprises a first end and a second end which are oppositely arranged, the first end is used for acting on a busbar workpiece, the second end is used for being close to a laser element, and the welding pressure head piece is further provided with a welding through hole penetrating from the first end to the second end. Laser emitted by the laser element passes through the through hole; and the two electric connecting parts are both installed on the welding pressure head piece, the two electric connecting parts are both used for abutting against the busbar workpiece at the first end to form electric contact, and when the two electric connecting parts are in a power-on state, current can flow through the area, matched with the first end, of the busbar workpiece to generate an electric field. Meanwhile, the utility model further discloses welding equipment applying the electric field auxiliary welding tool, the flowing state of a molten pool can be more effectively changed or controlled, and the technical problem that welding slag is prone to splashing in the existing bus-bar and battery cell positive and negative pole laser welding process is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of welding, in particular to an electric field assisted welding tool and welding equipment. Background Art

[0002] As the market demand for power batteries continues to grow, higher requirements are being placed on lithium battery performance, process technology, and production efficiency. Laser welding technology is often used in the production of battery modules and battery packs. For example, laser welding is used to weld the busbars (aluminum bars) in battery modules / battery packs to the positive and negative terminals of the battery cells.

[0003] In the related technology, a welding pressure head is usually configured during the laser welding process. You can refer to the authorization announcement number CN220196615U published on December 19, 2023, which is a tool for laser welding of square battery modules. The tool includes a bus and a welding pressure head, wherein the bus is arranged on the battery cell and on the positive and negative poles of the battery cell. One end of the welding pressure head is abutted on the bus, and the other end is arranged on the laser nozzle. The bus includes a substrate and several welding holes, wherein the substrate is abutted on the positive and negative poles of the battery cell; the welding holes are opened on the substrate, and the welding holes correspond one-to-one to the poles of the battery cell. The welding holes are used to position the welding pressure head. In this way, during welding, positioning can be achieved by cooperating with the bus bar and the welding pressure head to avoid sliding or dislocation of the welding pressure head, improve welding accuracy, and enhance the stability of the battery module.

[0004] However, welding slag is easily splashed during the rapid laser welding process, which requires that the welding slag be completely removed after the laser welding is completed to avoid the risk of short circuit of the battery module / battery pack caused by welding slag deposition. This makes the production process of battery modules / battery packs more complicated. Utility Model Content

[0005] The embodiments of the present utility model provide an electric field assisted welding tool and welding equipment, which can more effectively change or control the flow state of the molten pool, thereby enhancing the effective utilization of laser energy and improving processing efficiency, and improving the technical problem of easy splashing of welding slag during the existing laser welding process of the bus and the positive and negative poles of the battery cell.

[0006] In a first aspect, an embodiment of the present invention provides an electric field assisted welding tool, comprising:

[0007] a welding pressing head, the welding pressing head comprising a first end and a second end disposed opposite to each other, the first end being used to act on the busbar workpiece, the second end being used to be close to the laser element, the welding pressing head further comprising a welding through hole extending from the first end to the second end for passage of the laser beam emitted by the laser element; and

[0008] Two electrical connecting parts, both of which are installed on the welding pressure head, and both of which are used to abut against the busbar workpiece to form electrical contact, and when the two electrical connecting parts are powered on, they can allow current to flow through the area where the busbar workpiece cooperates with the first end to generate an electric field.

[0009] In one embodiment, in a radial direction of the welding through hole, the two electrical connection portions are respectively located on two opposite sides of a central axis of the welding through hole.

[0010] In one embodiment, an end portion of the electrical connection portion close to the first end protrudes from an end surface of the first end for abutting against the busbar workpiece.

[0011] In one embodiment, the electrical connection portion includes a current probe and an electrode wire terminal fixedly connected to the current probe, the current probe is distributed along the central axis of the welding through hole, and the current probe is fixedly connected to the welding pressure head component, and the current probe extends out of the welding pressure head component at one end away from the electrode wire terminal.

[0012] In one embodiment, the current probe includes an electrode connection portion, an electrode probe body, and an electrode probe head movably connected to the electrode probe body. The electrode probe body is inserted into the electrode assembly hole of the welding pressure head, and the electrode connection portion is fixedly connected to the electrode wire terminal.

[0013] In one embodiment, an electrode elastic member is provided between the electrode probe body and the electrode probe head, one end of the electrode elastic member abuts against the electrode probe body, and the other end of the electrode elastic member abuts against the electrode probe head.

[0014] In one embodiment, the electric field assisted welding tool further includes a wiring insulation pad, which is arranged between the welding pressure head and the electrode wiring portion of the current probe.

[0015] In one embodiment, the electric field assisted welding tool further includes an insulating bushing, which is sleeved between the electrode probe body and the electrode assembly hole.

[0016] In one embodiment, the electric field assisted welding tool further includes a pressure head insulator, which is fixedly connected to the welding pressure head component and is used to keep the welding pressure head component and the busbar workpiece insulated.

[0017] In a second aspect, an embodiment of the present invention provides a welding device, comprising the above-mentioned electric field assisted welding tool and a laser element, wherein the laser element is provided at the second end of the welding pressure head of the electric field assisted welding tool.

[0018] Beneficial effects of the embodiments of the present utility model:

[0019] By providing two electrical connections on the welding head, electromagnetic attraction is generated in the weld pool where the welding hole of the welding head is projected onto the busbar workpiece. This enhances the laser absorption rate of laser energy, increasing the penetration depth and achieving the goal of welding with lower power. It also suppresses weld pool oscillation, thereby improving the technical problem of spattering during laser welding. At the same time, it also improves the processing efficiency of laser welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a three-dimensional schematic diagram of an electric field assisted welding tool provided by an embodiment of the present utility model;

[0022] Figure 2 This is an exploded structural diagram of an electric field assisted welding tool provided in an embodiment of the present utility model;

[0023] Figure 3 This is an assembly structure diagram of an electric field assisted welding tool provided in an embodiment of the present utility model;

[0024] Figure 4 This is a partial assembly diagram of the electric field assisted welding tool provided in an embodiment of the present utility model;

[0025] Figure 5 This is a schematic diagram of the use of the electric field assisted welding tool provided in an embodiment of the present utility model.

[0026] Icons: 1-electrical connection part, 11-current probe, 111-electrode wiring part, 112-electrode probe body, 113-electrode probe head, 114-electrode elastic part, 12-electrode wire terminal, 3-welding pressure head, 31-welding through hole, 32-electrode assembly hole, 33-first end, 34-pressure head body, 35-welding fixing seat, 36-assembly fixing hole, 37-second end, 4-wiring insulation pad, 5-insulating bushing, 6-pressure head insulator, 7-busbar workpiece, 8-pole workpiece. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0028] Please combine the specific Figures 1 to 5 As shown, the present invention provides an electric field assisted welding tool, including a welding pressure head 3 and two electrical connection parts 1, wherein one electrical connection part 1 is defined as a positive electrode probe and the other electrical connection part 1 is defined as a negative electrode probe. The welding pressure head 3 includes a pressure head body 34 and a welding fixing seat 35. The welding fixing seat 35 is integrally formed with the pressure head body 34, but is not limited to being integrally formed. The welding fixing seat 35 can also be welded to the pressure head body 34. The welding fixing seat 35 is provided with an assembly fixing hole 36, which is used to assemble fasteners (such as bolts, screws, etc.).

[0029] For example, please refer to Figures 1 to 3 As shown, the aforementioned welding ram 3 further includes a first end 33 and a second end 37 disposed opposite each other. The first end 33 is configured to act on the busbar workpiece 7, and the second end 37 is configured to approach the laser element. The welding ram 3 also includes a welding through-hole 31 extending from the first end 33 to the second end 37. Specifically, the welding through-hole 31 extends through the ram body 34 along the centerline thereof to allow the laser beam emitted by the laser element to pass through. When the ram body 34 of the welding ram 3 is pressed against the busbar workpiece 7, the high-energy-density laser beam can pass through the welding through-hole 31 to radiate and heat the busbar workpiece 7.

[0030] In this embodiment, please refer to Figure 1 and Figure 3As shown, the two electrical connectors 1 extend along the extension direction of the welding through-hole 31, are arranged opposite each other, and are parallel to the central axis of the welding through-hole 31. Both electrical connectors 1 are mounted on the welding pressure head 3. In other embodiments, one of the two electrical connectors 1 may be parallel to the central axis of the welding through-hole 31, while the other may be inclined relative to the central axis of the welding through-hole 31. Alternatively, both electrical connectors 1 may be inclined relative to the central axis of the welding through-hole 31.

[0031] The core solution of this embodiment is that both electrical connectors 1 are used to abut against the busbar workpiece 7 to form electrical contact, and when the two electrical connectors 1 are energized, current can flow through the area where the busbar workpiece 7 and the first end 33 of the welding pressure head 3 cooperate to generate an electric field. That is, when the two electrical connectors 1 are energized, current can flow through the welding through-hole 31 and the weld pool projected on the busbar workpiece 7 and generate electromagnetic attraction in the weld pool. During this process, the pressure head body 34 of the welding pressure head 3 presses against the busbar workpiece 7, and the busbar workpiece 7 will be tightly attached to the pole workpiece. At this time, the two electrical connectors 1 also abut against the busbar workpiece 7. Then, when the two electrical connectors 1 are energized, current will flow from the positive electrode probe through the weld pool projected on the busbar workpiece 7 by the welding through-hole 31 and flow to the negative electrode probe.

[0032] In this way, the current generates perpendicular current lines in the weld pool toward the area through which the current flows, and a radial electromagnetic force pointing inward, that is, an electric field. This electromagnetic attraction is proportional to the square of the current density. At the same time, due to the huge difference in volume between the two electrical connectors 1 and the busbar workpiece 7, the current lines diverge rapidly in a small area between the end of the electrical connector 1 and the busbar workpiece 7, that is, the current distribution in the weld pool is extremely uneven. Therefore, a pressure difference caused by the additional current is formed in the weld pool. In other words, this uneven current distribution not only generates radial electromagnetic forces, but also axial electromagnetic forces from high current density areas to low current density areas. The electromagnetic attraction generated in the weld pool will change the flow state of the weld pool and the heat exchange conditions of the weld pool. Its electromagnetic effect can also have a reducing effect on the plasma induced by the laser beam.

[0033] Therefore, during the laser welding process, the electromagnetic effect of the additional current is utilized to achieve the following: without increasing the heat input, the effective utilization rate / laser absorption rate of the laser energy is enhanced mainly by changing the flow state and heat exchange conditions of the welding pool. This not only increases the penetration depth and achieves the purpose of welding with less power, but also suppresses the oscillation of the welding pool, thereby effectively reducing the problem of slag splashing during laser welding and improving the stability of the welding process. At the same time, it can also improve the processing efficiency of laser welding and control the formation of the weld. During the laser welding process, when the welding pressure head 3 presses the busbar workpiece 7, the two electrical connectors 1 automatically abut against the busbar workpiece 7. After power is turned on, an electric field / electromagnetic attraction can be generated in the welding pool without the need for additional manipulation of the two electrical connectors 1. The method is simple and easy to implement.

[0034] In addition, since the electromagnetic effect of the electric field can produce a stirring effect on the welding pool, the pores in the welding pool will be effectively removed, thereby refining the weld structure and achieving the unexpected effect of improving the weld strength.

[0035] It can be understood that the end portion of the electrical connection portion 1 close to the first end 33 of the welding pressure head 3 protrudes from the end surface of the first end 33 of the welding pressure head 3 to ensure that it can stably abut against the busbar workpiece 7.

[0036] To facilitate rapid and accurate positioning during welding and further improve the laser welding efficiency of the busbar workpiece 7 and the pole workpiece, the two electrical connection portions 1 are located on opposite sides of the central axis of the welding through hole 31 in the radial direction of the welding through hole 31 .

[0037] In some embodiments, please refer to Figure 2 and Figure 3 As shown, the electrical connection portion 1 includes a current probe 11 and an electrode wire terminal 12 fixedly connected to the current probe 11, wherein the current probe 11 is distributed along the central axis of the welding through-hole 31 and is fixedly connected to the pressing head body 34 of the welding pressing head 3. The end of the current probe 11 away from the electrode wire terminal 12 extends out of the pressing head body 34 of the welding pressing head 3, so that the end of the current probe 11 away from the electrode wire terminal 12 can abut and contact the busbar workpiece 7 when the pressing head body 34 presses the busbar workpiece 7. The electrode wire terminal 12 is used to electrically connect to an external wire, and the current will flow through the electrode wire terminal 12, the current probe 11, and then be conducted to the busbar workpiece 7.

[0038] In some embodiments, please refer to Figure 2 and Figure 4As shown, the current probe 11 includes an electrode connection portion 111, an electrode probe body 112, and an electrode probe head 113 movably connected to the electrode probe body 112. The pressure head body 34 is provided with an electrode assembly hole 32. Both ends of the electrode assembly hole 32 pass through the pressure head body 34, and the extension direction of the electrode assembly hole 32 is consistent with the central axis direction of the welding through-hole 31. The electrode probe body 112 is inserted into the electrode assembly hole 32 of the welding pressure head component 3, and the electrode connection portion 111 is fixedly connected to the electrode wire terminal 12. It should be noted that the electrode probe head 113 of the current probe 11 at least partially extends out of the electrode assembly hole 32 of the welding pressure head component 3.

[0039] For example, Figure 2 and Figure 4 As shown, the electrode probe body 112 is inserted into the electrode probe head 113, and an electrode elastic member 114 is provided between the electrode probe body 112 and the electrode probe head 113. The electrode elastic member 114 here can be a spring, but is not limited to a spring. It can also be a component made of a material with good elastic properties, such as a silicone sleeve. One end of the electrode elastic member 114 abuts the electrode probe body 112, and the other end of the electrode elastic member 114 abuts the electrode probe head 113. When the electrode probe head 113 is subjected to force, it will contract toward the electrode probe body 112 and simultaneously compress the electrode elastic member 114.

[0040] Furthermore, if Figure 4 As shown, a limiting portion is provided on the electrode probe body 112, and a limiting body is formed by protruding from the inner side wall of the electrode assembly hole 32 toward the inner side thereof. The limiting body and the limiting portion are provided correspondingly, and the electrode probe body 112 is inserted into the electrode assembly hole 32 until the limiting body abuts against the limiting portion, thereby completing the rapid positioning during the initial assembly of the current probe 11. Afterwards, the electrode wiring portion 111 is connected to the electrode wire terminal 12, and the assembly is simple and quick. Moreover, under the action of the electrode wiring portion 111, the electrode probe body 112 will not be separated from the electrode assembly hole 32, thereby achieving the purpose of firmly mounting the current probe 11 on the indenter body 34.

[0041] Such a configuration not only avoids the problem of the electrode probe head 113 and the busbar workpiece 7 being in rigid contact, which could damage the busbar workpiece 7 and the electrode probe head 113 of the current probe 11, but also improves the service life of the electrode probe head 113. At the same time, the electrode probe head 113 can automatically adjust its extension and contraction, thereby automatically eliminating assembly errors of the current probe 11. Furthermore, when the electrode probe head 113 of the current probe 11 abuts the busbar workpiece 7, the electrode elastic member 114 of the current probe 11 is compressed, and the electrode elastic member 114 also simultaneously applies a force to ensure that the electrode probe head 113 is tightly pressed against the busbar workpiece 7, ensuring that the electrode probe head 113 of the current probe 11 is stably abutted against the busbar workpiece 7.

[0042] In order to prevent the current from being conducted from the electrode connection portion 111 of the current probe 11 to the pressure head body 34 of the welding pressure head 3, part of the current is diverted from the pressure head body 34 to the busbar workpiece 7, thereby affecting the electric field generated by the welding pool. The inventors have provided a solution, please refer to the specific solution. Figure 2 and Figure 3 As shown, the electric field assisted welding tool also includes a wiring insulation pad 4, which is made of insulating material. The wiring insulation pad 4 is arranged between the welding pressure head 3 and the electrode wiring part 111 of the current probe 11, thereby effectively blocking the current from flowing from the electrode wiring part 111 to the pressure head body 34 of the welding pressure head 3.

[0043] In some embodiments, please refer to Figure 2 and Figure 3 As shown, the electric field assisted welding tooling also includes an insulating bushing 5, which is made of insulating material. The insulating bushing 5 extends along the extension direction of the electrode assembly hole 32. The insulating bushing 5 is sleeved between the electrode probe body 112 and the electrode assembly hole 32. The current flowing through the electrode probe body 112 will not be conducted and diverted to the pressure head body 34 of the welding pressure head part 3, thereby effectively avoiding part of the current from being diverted from the pressure head body 34 to the bus workpiece 7.

[0044] As a preferred method in this embodiment, please refer to Figure 2 and Figure 3 As shown, the electric field-assisted welding tool also includes a pressure head insulator 6. The pressure head insulator 6 is preferably made of ceramic material to ensure its structural strength. The pressure head insulator 6 is fixedly connected to the welding pressure head component 3. The fixed connection here is preferably a bolt connection, and can also be a clamping connection, or a combination of the above two connection methods. The pressure head insulator 6 is used to insulate the welding pressure head component 3 from the busbar workpiece 7. In this way, the risk of the parallel connection of the welding pressure head component 3 disrupting the electric field is effectively avoided.

[0045] Based on the structure and connection relationship of the above-mentioned electric field assisted welding tooling, the inventor also disclosed a welding device, including the above-mentioned electric field assisted welding tooling and a laser element, and the laser element is arranged at the second end 37 of the welding pressure head 3 of the electric field assisted welding tooling.

[0046] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, based on the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. An electric field assisted welding tool, characterized in that: include: a welding pressing head, the welding pressing head comprising a first end and a second end disposed opposite to each other, the first end being used to act on the busbar workpiece, the second end being used to be close to the laser element, the welding pressing head further comprising a welding through hole extending from the first end to the second end for passage of the laser beam emitted by the laser element; and Two electrical connecting parts, both of which are installed on the welding pressure head, and both of which are used to abut against the busbar workpiece to form electrical contact, and when the two electrical connecting parts are powered on, they can allow current to flow through the area where the busbar workpiece cooperates with the first end to generate an electric field.

2. The electric field assisted welding tool according to claim 1, characterized in that: In the radial direction of the welding through hole, the two electrical connection portions are respectively located on two opposite sides of the central axis of the welding through hole.

3. The electric field assisted welding tool according to claim 1 or 2, characterized in that: An end portion of the electrical connection portion close to the first end protrudes from an end surface of the first end and is used for abutting against the busbar workpiece.

4. The electric field assisted welding tool according to claim 3, characterized in that: The electrical connection portion includes a current probe and an electrode wire terminal fixedly connected to the current probe. The current probe is distributed along the central axis of the welding through hole, and the current probe is fixedly connected to the welding pressure head. One end of the current probe away from the electrode wire terminal extends out of the welding pressure head.

5. The electric field assisted welding tool according to claim 4, characterized in that: The current probe includes an electrode connection portion, an electrode probe body, and an electrode probe head movably connected to the electrode probe body. The electrode probe body is inserted into the electrode assembly hole of the welding pressure head, and the electrode connection portion is fixedly connected to the electrode wire terminal.

6. The electric field assisted welding tool according to claim 5, characterized in that: An electrode elastic member is provided between the electrode probe body and the electrode probe head. One end of the electrode elastic member abuts against the electrode probe body, and the other end of the electrode elastic member abuts against the electrode probe head.

7. The electric field assisted welding tool according to claim 5, characterized in that: It also includes a wiring insulation pad, which is arranged between the welding pressure head and the electrode wiring portion of the current probe.

8. The electric field assisted welding tool according to claim 5, 6 or 7, characterized in that: It also includes an insulating bushing, which is sleeved between the electrode probe body and the electrode assembly hole.

9. The electric field assisted welding tool according to claim 1 or 2, characterized in that: It also includes a pressure head insulator, which is fixedly connected to the welding pressure head component and is used to keep the welding pressure head component and the busbar workpiece insulated.

10. A welding device, characterized in that: include: The electric field assisted welding tool according to any one of claims 1 to 9; A laser element is provided at the second end of the welding pressure head of the electric field assisted welding tool.

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