Resistance welding jig and method for cylindrical batteries

Abstract

The present application provides a resistance welding jig and method for cylindrical batteries. The resistance welding jig includes a welding pin, a positioning member and an adaptive elastic member. The welding pin is used to pass through the through hole of the winding core to perform resistance welding on the welding part, and an assembly structure is provided on the welding pin; the positioning member is used to be positioned on the cylindrical battery, and a guide structure is provided on the positioning member, and the guide structure is used for the welding pin to pass through to guide the welding pin; the adaptive elastic member is arranged between the assembly structure and the positioning member; when the resistance welding jig is assembled on the cylindrical battery, the adaptive elastic member makes the welding pin free, and the welding pin is in a vertical state by the positioning of the positioning member and the guidance of the guide structure. When the welding pin is pressed, the adaptive elastic member is compressed, so that the welding pin vertically drops to contact with the welding part. The present application can ensure that the welding pin remains in a vertical state during resistance welding.

Description

Technical Field

[0001] The present application relates to the technical field of cylindrical batteries, and in particular to a resistance welding jig and method for cylindrical batteries. Background Art

[0002] At present, lithium-ion / sodium-ion cylindrical batteries have gradually become mainstream products in the new energy industry due to their high energy density, good capacity consistency, and support for high-rate charging and discharging. More and more manufacturers continue to pursue high stability and high production capacity of cylindrical battery performance. However, there are currently the following common problems:

[0003] In order to increase the production capacity of cylindrical power batteries, the shell bottom (and the collector plate) resistance welding structure is generally preferred. However, (the automatic line generally inserts the pins first, and then welds one by one) the welding pins are generally not perpendicular to the shell bottom, so only round-headed structured welding pins can be used. The welding area is small, and when the vehicle is loaded and vibrated (the larger winding core inside jumps), it directly impacts the welding position, which is easy to fall off, resulting in the risk of open circuit failure of the battery. In addition, the round-headed structured welding pin has a small welding area and cannot meet the use requirements of high-rate charging and discharging of power batteries, or (due to the small resistance welding area) the battery temperature rise is large, which brings safety risks to the battery. Summary of the invention

[0004] The purpose of the present application is to provide a resistance welding jig and method for cylindrical batteries, which can solve the technical problem that the welding needle is not vertical during resistance welding.

[0005] In order to achieve the above-mentioned object, the present application provides a resistance welding jig for a cylindrical battery, which is used to perform resistance welding on a portion to be welded at the bottom of the cylindrical battery, wherein the portion to be welded corresponds to a winding core through hole of the cylindrical battery, and the resistance welding jig comprises:

[0006] A welding needle, the welding needle is used to pass through the through hole of the winding core to perform resistance welding on the to-be-welded portion, and the welding needle is provided with an assembly structure;

[0007] A positioning member, the positioning member is used to be positioned on the cylindrical battery, the positioning member is provided with a guide structure, the guide structure is used for the welding needle to pass through so as to guide the welding needle;

[0008] An adaptive elastic member, wherein the adaptive elastic member is arranged between the assembly structure and the positioning member;

[0009] When the resistance welding jig is assembled on the cylindrical battery, the adaptive elastic member allows the welding needle to be in a free state. With the positioning of the positioning member and the guidance of the guide structure, the welding needle is in a vertical state. When the welding needle is pressed, the adaptive elastic member is compressed, causing the welding needle to drop vertically to contact the part to be welded.

[0010] Optionally, the head of the welding needle forms a welding plane for contacting the plane of the area to be welded.

[0011] Optionally, the positioning member is configured to be positioned at an open end of a housing of a cylindrical battery.

[0012] Optionally, a positioning anti-deviation groove is formed on the positioning member, and the positioning member is positioned at the opening end of the shell through the positioning anti-deviation groove.

[0013] Optionally, the positioning anti-deviation groove includes two guide surfaces and a groove bottom plane located on both sides thereof, the guide surfaces are used to guide the opening end of the shell into the positioning anti-deviation groove, and the groove bottom plane is used to adapt to the end surface of the opening end of the shell.

[0014] Optionally, the guiding surface is an inclined surface.

[0015] Optionally, the positioning member is formed with a through hole, and the guide structure is installed in the through hole;

[0016] The soldering needle passes through the through hole and the guide structure.

[0017] Optionally, the guide structure is a ball guide sleeve.

[0018] Optionally, the upper end of the adaptive elastic member is fixed to the assembly structure, and the lower end of the adaptive elastic member is fixed to the positioning member.

[0019] In order to achieve the above-mentioned object, the present application also provides a resistance welding method for a cylindrical battery, characterized in that the resistance welding method is performed using the resistance welding jig as described above, and the resistance welding method comprises:

[0020] Assembling the resistance welding jig to the cylindrical battery, wherein the positioning member is positioned on the cylindrical battery, the welding needle penetrates the winding core through hole and is in a free state, and the welding needle is in a vertical state by the positioning of the positioning member and the guidance of the guide structure;

[0021] The welding needle is pressed down, the adaptive elastic member is compressed, and the welding needle is vertically dropped under the guidance of the guide structure until it contacts the part to be welded, so as to perform resistance welding.

[0022] The present application utilizes a resistance welding jig to perform resistance welding on the to-be-welded portion of a cylindrical battery. When the resistance welding jig is assembled to the cylindrical battery, the welding needle penetrates into the through hole of the winding core and is in a free state due to the setting of the adaptive elastic member. The welding needle is in a vertical state by the positioning of the positioning member and the guidance of the guide structure. Then the welding needle can be pressed down, the adaptive elastic member is compressed, and the welding needle is vertically lowered under the guidance of the guide structure to contact the to-be-welded portion for resistance welding. The present application can ensure that the welding needle remains in a vertical state during resistance welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of a resistance welding jig for cylindrical batteries according to an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the three-dimensional structure of the resistance welding fixture for cylindrical batteries from another perspective according to an embodiment of the present application.

[0025] Figure 3 It is a schematic diagram of the three-dimensional structure of the welding pin according to the embodiment of the present application.

[0026] Figure 4 It is a schematic diagram of the three-dimensional structure of the welding needle in another perspective of the embodiment of the present application.

[0027] Figure 5 It is a schematic diagram of the cross-sectional structure of the resistance welding fixture of the embodiment of the present application assembled to the cylindrical battery. DETAILED DESCRIPTION

[0028] In order to explain the technical content, structural features, and achieved effects of the present application in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0030] See also Figures 1 to 5 The embodiment of the present application discloses a resistance welding jig for a cylindrical battery, which is used for resistance welding of a to-be-welded portion located at the bottom of the cylindrical battery 1, and the to-be-welded portion corresponds to the winding core through hole 111 of the cylindrical battery 1. Specifically, a shell 12 is sleeved on the outer side of the winding core 11 of the cylindrical battery 1, and a current collecting plate 13 is provided between the bottom wall 121 of the shell 12 and the winding core 11. The to-be-welded portion refers to: the position where the current collecting plate 13 and the bottom wall 121 of the shell 12 need to be welded.

[0031] The resistance welding fixture comprises: a welding needle 20 , a positioning member 30 and an adaptive elastic member 40 .

[0032] The welding needle 20 is used to pass through the winding core through hole 111 to perform resistance welding on the welding position to be welded, and an assembly structure 50 is provided on the welding needle 20. Specifically, the assembly structure 50 is a fastener assembled on the welding needle 20.

[0033] It should be noted that the welding needle 20 is not limited to completely passing through the winding core through hole 111. For example, the collecting plate 13 may be formed with a protrusion extending upward to the bottom of the winding core through hole 111. In this case, the welding needle 20 does not completely pass through the winding core through hole 111.

[0034] The positioning member 30 is used to be positioned on the cylindrical battery 1 . A guide structure 60 is provided on the positioning member 30 . The guide structure 60 is used for allowing the welding needle 20 to pass through so as to guide the welding needle 20 .

[0035] The adaptive elastic member 40 is disposed between the assembly structure 50 and the positioning member 30 . The adaptive elastic member 40 is located at a side of the positioning member 30 away from the winding core 11 .

[0036] When the resistance welding jig is assembled on the cylindrical battery 1, the adaptive elastic member 40 makes the welding needle 20 free, that is, when the welding needle 20 passes through the winding core through hole 111 and the positioning member 30 is positioned on the cylindrical battery 1, the adaptive elastic member 40 makes the welding needle 20 in a free state (a suspended state spaced from the welding position), preferably, a small space is formed between the welding needle 20 and the welding position. By the positioning of the positioning member 30 and the guidance of the guide structure 60, the welding needle 20 is in a vertical state.

[0037] When the welding needle 20 is pressed, the adaptive elastic member 40 is compressed, so that the welding needle 20 moves downward to contact the welding position. During the process of the welding needle 20 descending, due to the guidance of the guide structure 60, the welding needle 20 can vertically descend to contact the welding position.

[0038] Specifically, the upper end of the adaptive elastic member 40 is fixed to the assembly structure 50, and the lower end of the adaptive elastic member 40 is fixed to the positioning member 30. Before the resistance welding jig is used, it is assembled as a whole, and after the welding needle 20 passes through the guide structure 60, the upper and lower ends of the adaptive elastic member 40 are fixed to the assembly structure 50 and the positioning member 30 respectively. When the resistance welding jig is used for resistance welding, the resistance welding jig is assembled as a whole to the cylindrical battery 1, wherein the welding needle 20 first penetrates the winding core through hole 111, and then the positioning member 30 is positioned on the cylindrical battery 1. Of course, the present application is not limited to the resistance welding jig being assembled as a whole before use.

[0039] Specifically, the adaptive elastic member 40 is a spring.

[0040] It can be understood that the cylindrical battery 1 on which the resistance welding jig of the present application is assembled is a cylindrical battery 1 that has not completed the final assembly, and the welding needle 20 can pass through the winding core through hole 111. Specifically, the cylindrical battery 1 at this time includes a winding core 11, a shell 12 sleeved on the outside of the winding core 11, and a current collecting plate 13 arranged between the winding core 11 and the bottom wall 121 of the shell 12, and the opening end 122 of the shell 12 has not yet been assembled with a cover.

[0041] The present application uses a resistance welding jig to perform resistance welding on the to-be-welded portion of the cylindrical battery 1. When the resistance welding jig is assembled to the cylindrical battery 1, the welding needle 20 penetrates the winding core through hole 111 and is in a free state due to the setting of the adaptive elastic member 40. The welding needle 20 is in a vertical state by the positioning of the positioning member 30 and the guidance of the guide structure 60. Then the welding needle 20 can be pressed down, the adaptive elastic member 40 is compressed, and the welding needle 20 is vertically lowered under the guidance of the guide structure 60 to contact the to-be-welded portion for resistance welding. The present application can ensure that the welding needle 20 remains in a vertical state during resistance welding.

[0042] Specifically, the head of the welding needle 20 forms a welding plane 21 for contacting the plane of the part to be welded. Since the present application can ensure that the welding needle 20 remains vertical during resistance welding, when the welding plane 21 is formed on the head of the welding needle 20, it can contact the plane of the part to be welded, and compared with the round head structure, a larger welding area can be achieved, which is conducive to solving technical problems such as the welding position being easy to fall off due to the small welding area, the inability to meet the use requirements of the cylindrical battery 1 for high-rate charging and discharging, or the large temperature rise of the cylindrical battery 1.

[0043] Specifically, the tail of the solder pin 20 forms a tail plane 22 .

[0044] In some embodiments, the positioning member 30 is configured to be positioned at the open end 122 of the housing 12 of the cylindrical battery 1 .

[0045] Specifically, a positioning anti-deviation groove 31 is formed on the positioning member 30, and the positioning member 30 is positioned at the open end 122 of the housing 12 through the positioning anti-deviation groove 31. That is, all or part of the open end 122 of the housing 12 will enter the positioning anti-deviation groove 31, and the positioning member 30 is positioned by the cooperation of the positioning anti-deviation groove 31 and the open end 122 of the housing 12, thereby realizing the positioning of the positioning member 30, and then realizing the positioning of the guide structure 60. When the guide structure 60 realizes the positioning, the welding needle 20 can be kept vertical under the guiding effect of the guide structure 60.

[0046] More specifically, the positioning anti-deviation groove 31 includes two guide surfaces 311 and a groove bottom plane 312 located on both sides thereof, the guide surface 311 is used to guide the open end 122 of the housing 12 to enter the positioning anti-deviation groove 31, and the groove bottom plane 312 is used to adapt to the end surface of the open end 122 of the housing 12, that is, the width of the groove bottom plane 312 is substantially the same as the width of the end surface of the open end 122 of the housing 12, and when the two cooperate, they can play a role of limiting. Of course, when the positioning anti-deviation groove 31 is provided with two guide surfaces 311 and a groove bottom plane 312, the guide surface 311 is not necessarily directly connected to the groove bottom plane 312, for example, the two guide surfaces 311 can be respectively connected to two vertical surfaces, and the two vertical surfaces are respectively connected to the two ends of the groove bottom plane 312, and the two vertical surfaces and the groove bottom plane 312 are defined as a vertical groove having a width equal to the open end 122 of the housing 12.

[0047] Furthermore, the guide surface 311 is an inclined surface, but is not limited thereto.

[0048] In some embodiments, the positioning member 30 is formed with a through hole 32, and the guide structure 60 is installed in the through hole 32; the soldering pin 20 passes through the through hole 32 and the guide structure 60. In order to facilitate the formation of the through hole 32 in which the guide structure 60 can be installed, the positioning member 30 can include two parts, and the guide structure 60 can be first assembled in one part, and then assembled in the other part.

[0049] It is understandable that the present application does not limit the specific form of the positioning member 30, as long as it can be positioned on the cylindrical battery 1 and when positioned on the cylindrical battery 1, the positioning of the guide structure 60 can be achieved, thereby allowing the welding needle 20 to be in a vertical state.

[0050] In some embodiments, the guide structure 60 is a ball guide bushing, but is not limited thereto.

[0051] To facilitate understanding of the present application, the specific use process is described below using the examples shown in the drawings of the present application as an example, which should not be regarded as limiting the present application.

[0052] First, the solder pin 20 is inserted into the winding core through hole 111 .

[0053] Next, the positioning member 30 is positioned based on the cooperation between the positioning anti-deviation groove 31 and the open end 122 of the shell 12 . When the positioning member 30 is positioned, the suspended welding needle 20 is in a vertical state under the guidance of the guide structure 60 .

[0054] Next, the welding equipment presses down the tail of the welding needle 20 to compress the adaptive elastic member 40 , and the welding needle 20 is precisely guided by the guide structure 60 to vertically descend, and resistance welding is performed on the collecting plate 13 and the bottom wall 121 of the shell 12 .

[0055] After welding is completed, the tail of the welding needle 20 is clamped and taken out, and the adaptive elastic member 40 is adaptively restored.

[0056] Please combine Figures 1 to 5 The present application also discloses a resistance welding method for a cylindrical battery 1, the resistance welding method is performed using the resistance welding jig as described above, and the resistance welding method includes:

[0057] Assemble the resistance welding jig to the cylindrical battery 1, wherein the positioning member 30 is positioned on the cylindrical battery 1, and the welding needle 20 penetrates the winding core through hole 111 and is in a free state. With the positioning of the positioning member 30 and the guidance of the guide structure 60, the welding needle 20 is in a vertical state;

[0058] The welding needle 20 is pressed down, the adaptive elastic member 40 is compressed, and the welding needle 20 is vertically lowered under the guidance of the guide structure 60 until it contacts the position to be welded, and resistance welding is performed.

[0059] The present application uses a resistance welding jig to perform resistance welding on the to-be-welded portion of the cylindrical battery 1. When the resistance welding jig is assembled to the cylindrical battery 1, the welding needle 20 penetrates the winding core through hole 111 and is in a free state due to the setting of the adaptive elastic member 40. The welding needle 20 is in a vertical state by the positioning of the positioning member 30 and the guidance of the guide structure 60. Then the welding needle 20 can be pressed down, the adaptive elastic member 40 is compressed, and the welding needle 20 is vertically lowered under the guidance of the guide structure 60 to contact the to-be-welded portion for resistance welding. The present application can ensure that the welding needle 20 remains in a vertical state during resistance welding.

[0060] The above disclosure is only a preferred example of the present application, and its role is to facilitate the technical personnel in this field to understand and implement it. Of course, it cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application still fall within the scope covered by the present application.

Claims

1. A resistance welding jig for a cylindrical battery, used for resistance welding a portion to be welded at the bottom of the cylindrical battery, wherein the portion to be welded corresponds to a through hole of the winding core of the cylindrical battery, and characterized in that: The resistance welding fixture comprises: A welding needle, the welding needle is used to pass through the through hole of the winding core to perform resistance welding on the to-be-welded portion, and the welding needle is provided with an assembly structure; A positioning member, the positioning member is used to be positioned on the cylindrical battery, the positioning member is provided with a guide structure, the guide structure is used for the welding needle to pass through so as to guide the welding needle; An adaptive elastic member, wherein the adaptive elastic member is arranged between the assembly structure and the positioning member; When the resistance welding jig is assembled on the cylindrical battery, the adaptive elastic member makes the welding pin free, and the welding pin is in a vertical state by the positioning of the positioning member and the guidance of the guide structure. When the welding pin is pressed, the adaptive elastic member is compressed, so that the welding pin vertically drops to contact the part to be welded; The positioning member is configured to be positioned at an open end of a housing of a cylindrical battery; A positioning anti-deviation groove is formed on the positioning member, and the positioning member is positioned at the opening end of the housing through the positioning anti-deviation groove; The positioning anti-deviation groove comprises two guide surfaces and a groove bottom plane located on both sides thereof, wherein the guide surfaces are used to guide the opening end of the shell to enter the positioning anti-deviation groove, and the groove bottom plane is used to adapt to the end surface of the opening end of the shell; The upper end of the adaptive elastic member is fixed to the assembly structure, and the lower end of the adaptive elastic member is fixed to the positioning member.

2. The resistance welding jig for cylindrical batteries according to claim 1, characterized in that: The head of the welding needle forms a welding plane for contacting with the plane of the place to be welded.

3. The resistance welding jig for cylindrical batteries according to claim 1, characterized in that: The guiding surface is an inclined surface.

4. The resistance welding jig for cylindrical batteries according to claim 1, characterized in that: The positioning member is formed with a through hole, and the guide structure is installed in the through hole; The soldering needle passes through the through hole and the guide structure.

5. The resistance welding jig for cylindrical batteries according to claim 1 or 4, characterized in that: The guide structure is a ball guide sleeve.

6. A resistance welding method for cylindrical batteries, characterized in that: The resistance welding method is performed using the resistance welding jig according to any one of claims 1 to 5, and the resistance welding method comprises: Assembling the resistance welding jig to the cylindrical battery, wherein the positioning member is positioned on the cylindrical battery, the welding needle penetrates the winding core through hole and is in a free state, and the welding needle is in a vertical state by the positioning of the positioning member and the guidance of the guide structure; The welding needle is pressed down, the adaptive elastic member is compressed, and the welding needle is vertically dropped under the guidance of the guide structure until it contacts the part to be welded, so as to perform resistance welding.

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