Battery sealing nail welding method and welding auxiliary tool

Abstract

The invention relates to the technical field of power batteries, and discloses a battery sealing nail welding method and an auxiliary welding tool. The battery sealing nail welding method comprises the following steps that a battery is fixed, a sealing nail is placed into a liquid injection hole of the battery, then the sealing nail is pressed tightly, and a to-be-welded area of the sealing nail is exposed; spot welding is carried out on a to-be-welded area of the sealing nail to form an even number of spot welding marks, every two spot welding marks are symmetrical relative to the center of the sealing nail, all the spot welding marks are provided with at least one symmetrical line, full welding is carried out with a point A and a point B which are arranged at an interval on the symmetrical line as full welding starting points, and two sections of full welding marks are formed. And the two sections of full-length welding marks cover the spot welding marks, and the two sections of full-length welding marks are in butt joint end to end to form a closed loop. According to the invention, the welding stress can be effectively released, the phenomena of overlarge tilting of the sealing nail, poor welding and poor sealing performance caused by a gap between the sealing nail and the battery top cover are prevented, and the welding efficiency and the welding quality are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power batteries, and in particular relates to a battery sealing nail welding method and a welding auxiliary tooling. Background Art

[0002] Laser welding of sealing pins is the last welding process in the assembly of metal shell batteries, and the welding quality is of vital importance. During the laser welding of the sealing pins, there is a gap between the sealing pins and the injection hole. On the one hand, the gap comes from the assembly of the sealing pins and the injection hole. Affected by the flatness of the sealing pins and the surrounding areas of the injection hole, the sealing pins are pressed by the pressing pin mechanism and are in a pressed state, which leads to uneven force. On the other hand, the gap comes from spot welding. As the heat input increases, the molten pool changes rapidly, causing local warping and an increase in the gap between the end face of the sealing pin and the end face of the injection hole. After the spot welding of the sealing pins is completed, continuous laser welding will result in incomplete penetration and blown welds. The sealing performance of the sealing pins is poor after welding. Welding defects directly lead to the scrapping of the battery, which will cause waste of materials, manpower and other costs. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a battery sealing nail welding method and a welding auxiliary tooling, which can improve the sealing nail welding yield and sealing performance.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] On the one hand, a battery sealing nail welding method is provided, comprising the following steps:

[0006] Fix the battery, put the sealing pin into the injection hole of the battery, and then press the sealing pin tightly, so that the area to be welded of the sealing pin is exposed;

[0007] Spot welding is performed on the area to be welded of the sealing pin to form an even number of spot welding marks, where every two spot welding marks are symmetrical with respect to the center of the sealing pin, and all the spot welding marks have at least one symmetry line, and full welding is performed with two spaced-apart points A and B on the symmetry line as full welding starting points to form two sections of full welding marks, and the two sections of the full welding marks cover the spot welding marks, and the two sections of the full welding marks are butted end to end to form a closed loop.

[0008] As a further solution of the battery sealing nail welding method, when spot welding the sealing nail, a welding spot is determined and then spot welding is performed. After a spot welding mark is formed, the next welding spot that is centrally symmetrical with the spot welding mark is welded.

[0009] As a further solution of the battery sealing nail welding method, when spot welding the sealing nail, after determining two centrally symmetrical welding points, the two welding points are spot welded simultaneously.

[0010] As a further solution of the battery sealing nail welding method, the number of the spot welding marks is at least four.

[0011] As a further solution of the battery sealing pin welding method, before the sealing pin is placed in the liquid injection hole of the battery, a closed-loop contour line with the center of the circle of the sealing pin as the center is drawn on the end face of the sealing pin facing away from the liquid injection hole, an even number of centrally symmetrical welding points and a symmetry line that makes all the welding points symmetrical are drawn at intervals on the closed-loop contour line, and the closed-loop contour line is divided into two symmetrical semi-closed-loop contour lines through the symmetry line, and the intersection points of the symmetry line and the closed-loop contour line are the point A and the point B.

[0012] As a further solution of the battery sealing nail welding method, the closed-loop contour line is a regular symmetrical figure.

[0013] On the other hand, a welding auxiliary tooling for the battery sealing nail welding method is provided, comprising a base and a clamping mechanism and a pressing mechanism arranged on the base, wherein the clamping mechanism comprises a clamp and a first driving component, the first driving component is connected to the clamp and is used to drive the clamp to fix the battery; the pressing mechanism comprises a pressing block and a second driving component, the second driving component is connected to the pressing block and is used to drive the pressing block to press the sealing nail into the injection hole of the battery;

[0014] When the pressing block presses the sealing pin, the area to be welded of the sealing pin is exposed from the pressing block.

[0015] As a further solution of the welding auxiliary tooling, the pressing block is provided with an avoidance hole facing the sealing pin along its thickness direction, and when the pressing block presses the sealing pin, the area of ​​the sealing pin to be welded is exposed from the avoidance hole.

[0016] As a further solution of the welding auxiliary tooling, the clamp includes a fixed part and a movable part, the fixed part and the movable part are arranged at intervals along the X direction, the fixed part is fixed on the base, and a receiving groove for placing the battery is provided on the side of the fixed part facing the movable part, the first driving component is installed on the base and is transmission-connected to the movable part, and the first driving component can drive the movable part to move toward the fixed part to fix the battery in the receiving groove.

[0017] As a further solution of the welding auxiliary tooling, the second driving assembly is installed on a side of the fixed part away from the movable part, the pressing block is located above the accommodating groove, and the second driving assembly can drive the pressing block to move up and down.

[0018] Beneficial effects:

[0019] After the battery is fixed and the sealing nail is compressed by the present invention, spot welding is first performed in a centrally symmetrical manner, and after the spot welding is completed, two-stage full welding is performed, and the two-stage full welding marks are butted end to end to form a closed loop, thereby realizing the welding of the sealing nail. The use of this welding method can effectively release welding stress, prevent the sealing nail from tilting too much, causing poor welding, and poor sealing performance due to the gap between the sealing nail and the battery top cover at the end face of the injection hole, thereby improving welding efficiency and welding quality.

[0020] The present invention utilizes welding auxiliary tooling to achieve battery fixation and sealing pin compression. When the pressing block presses the sealing pin, the area to be welded of the sealing pin can be completely exposed, so that the pressing block can compress the sealing pin throughout the process of spot welding and full welding of the sealing pin, thereby preventing the sealing pin from partially warping too much during the welding process and affecting the welding yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0022] Figure 1 It is a structural schematic diagram of the welding auxiliary tooling described in an embodiment of the present invention.

[0023] Figure 2 It is a schematic side view of the structure of the welding auxiliary tooling according to an embodiment of the present invention.

[0024] Figure 3 It is a structural schematic diagram of the clamping mechanism described in an embodiment of the present invention.

[0025] Figure 4 It is a structural schematic diagram of a battery placed in a receiving groove of a welding auxiliary tooling according to an embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of the closed-loop contour line, welding points and symmetry lines drawn on the sealing pin described in the embodiment of the present invention.

[0027] Figure 6 It is a schematic diagram of the full welding direction of two sections of the sealing pin after spot welding according to an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the sealing pin after it is fully welded according to an embodiment of the present invention.

[0029] Figures 1 to 7 middle:

[0030] 100, base;

[0031] 200, clamping mechanism; 210, clamp; 211, fixed portion; 212, movable portion; 213, receiving groove; 220, first driving assembly; 221, first cylinder; 222, first piston rod; 230, first guide portion;

[0032] 300, clamping mechanism; 310, pressing block; 311, avoidance hole; 320, second driving assembly; 321, linear motor; 322, output shaft; 330, third guide portion; 340, intermediate connecting member; 341, first connecting portion; 342, second connecting portion; 343, fifth guide portion; 344, sixth guide portion; 350, fourth guide portion;

[0033] 400, second guide portion;

[0034] 10. Battery; 11. Top cover; 20. Sealing nail;

[0035] 1. Closed-loop contour line; 2a-2d, welding point; 3. Symmetry line; 4a-4d, spot welding mark; 5. Full welding mark. DETAILED DESCRIPTION

[0036] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of 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.

[0037] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, if the terms "upper", "lower", "left", "right" and other directions or positional relationships appear, they are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, if the terms "first", "second", etc. appear, they are only used to distinguish in the description and have no special meaning.

[0040] The battery sealing nail welding method of this embodiment includes the following steps:

[0041] Fix the battery, put the sealing pin into the battery's injection hole, press the sealing pin tightly, and expose the area of ​​the sealing pin to be welded;

[0042] Spot welding is performed on the area to be welded of the sealing pin to form an even number of spot welding marks, where every two spot welding marks are symmetrical with respect to the center of the sealing pin, and all the spot welding marks have at least one symmetry line, and full welding is performed using two spaced-apart points A and B on the symmetry line as full welding starting points to form two sections of full welding marks, and the two sections of full welding marks cover all the spot welding marks, and the two sections of full welding marks are butted end to end to form a closed loop.

[0043] In this embodiment, the battery is first fixed, and then the sealing pin is pressed against the liquid injection hole of the battery, and spot welding is performed at a position symmetrical to the center of the sealing pin. Then, two points spaced apart on the symmetry line of the spot welding mark are used as the starting point for full welding, and full welding is performed along two semi-closed loop paths to form two sections of full welding marks that are butted end to end to form a closed loop. The welding stress can be effectively released, and the sealing pin can be prevented from being excessively lifted, poorly welded, and having poor sealing performance due to the gap between the sealing pin and the battery top cover, thereby improving the welding efficiency and welding quality.

[0044] Optionally, when spot welding the sealing pin, spot welding is performed after a welding spot is determined. After the spot welding mark is formed, the next welding spot that is centrally symmetrical with the spot welding mark is welded, thereby forming two spot welding marks that are centrally symmetrical with respect to the sealing pin. The spot welding of the remaining welding spots is continued according to this step until the spot welding of all welding spots is completed.

[0045] Furthermore, when spot welding the sealing pin, after determining two centrally symmetrical welding points, spot welding is performed on the two welding points at the same time, thereby forming two centrally symmetrical spot welding marks relative to the sealing pin, and spot welding of the remaining welding points is continued according to this step until spot welding of all welding points is completed. The spot welding sequence of this embodiment can further prevent the sealing pin from tilting too much and causing poor welding due to the gap between the sealing pin and the battery top cover near the injection hole.

[0046] In this embodiment, the number of spot welding marks is at least four, such as four, six or eight, etc., which can be determined according to the size of the sealing pin to avoid excessive local warping of the sealing pin.

[0047] Furthermore, before the sealing pin is placed in the liquid injection hole of the battery, a closed-loop contour line with the center of the sealing pin as the center is drawn on the end face of the sealing pin facing away from the liquid injection hole, an even number of centrally symmetrical welding points and a symmetry line that makes all the welding points symmetrical are drawn at intervals on the closed-loop contour line, and the closed-loop contour line is divided into two symmetrical semi-closed-loop contour lines through the symmetry line, and the intersection points of the symmetry line and the closed-loop contour line are point A and point B.

[0048] In this embodiment, a closed-loop contour line and spot welding points can be first drawn in the area to be welded of the sealing pin according to the size of the sealing pin, and the starting positions of the two sections of full welding can be determined by drawing symmetry lines, so as to provide a welding reference for subsequent spot welding and full welding positions, and can effectively improve the efficiency of spot welding and full welding, and avoid deviations in the welding position and poor welding, resulting in poor sealing of the injection hole.

[0049] Optionally, the closed-loop contour line is a regular symmetrical shape, such as a circle, an ellipse, a rectangle, a square or a hexagon, etc., to meet the need for symmetry of the welding point.

[0050] In this embodiment, the battery is a square battery or a cylindrical battery. The battery shell is a metal shell. When the sealing pin is pressed tightly in the injection hole, laser welding of the sealing pin can achieve welding and fixing of the sealing pin and the battery shell at the end face of the injection hole.

[0051] Of course, the battery sealing nail welding process in this embodiment is not limited to the sealing of the liquid injection hole, but is also applicable to the sealing of other similar holes that are not used for liquid injection.

[0052] This embodiment also provides a welding auxiliary tooling for the above-mentioned battery sealing nail welding method, such as Figures 1 to 4 As shown, the welding auxiliary tooling includes a base 100 and a clamping mechanism 200 and a pressing mechanism 300 arranged on the base 100. The clamping mechanism 200 includes a clamp 210 and a first driving component 220. The first driving component 220 is connected to the clamp 210 and is used to drive the clamp 210 to fix the battery 10; the pressing mechanism 300 includes a pressing block 310 and a second driving component 320. The second driving component 320 is connected to the pressing block 310 and is used to drive the pressing block 310 to press the sealing nail 20 into the injection hole of the battery 10; when the pressing block 310 presses the sealing nail 20, the area to be welded of the sealing nail 20 is exposed to the pressing block 310.

[0053] In conventional sealing pin welding auxiliary tooling, when the pressure block presses the sealing pin, only the spot welding position of the sealing pin is exposed, and the full welding position is blocked by the pressure block. Therefore, when using conventional sealing pin welding auxiliary tooling, after the spot welding is completed, the pressure block needs to be removed before full welding. At this time, due to the partial lifting of the sealing pin, partial poor welding may occur during full welding, which affects the sealing of the battery.

[0054] In the present embodiment, when the pressing block 310 presses the sealing pin 20, the area to be welded on the sealing pin 20 including the spot welding position and the full welding position is all exposed to the pressing block 310. Therefore, during the spot welding and full welding process, the pressing block 310 presses the sealing pin 20 throughout the whole process, which can avoid the gap between the sealing pin 20 and the top cover 11 of the battery 10 being too large to affect the welding effect.

[0055] In order to fully expose the area to be welded of the sealing pin 20 , in this embodiment, an avoidance hole 311 facing the sealing pin 20 is set through the pressing block 310 along its thickness direction. When the pressing block 310 presses the sealing pin 20 , the area to be welded of the sealing pin 20 is exposed in the avoidance hole 311 .

[0056] Optionally, the shape of the avoidance hole 311 can be circular, elliptical, oblong, rectangular or hexagonal, etc. Specifically, the shape of the avoidance hole 311 is consistent with the shape of the closed-loop contour line pre-drawn on the sealing pin 20, and the size of the avoidance hole 311 is slightly larger than the closed-loop contour line to facilitate welding of the sealing pin 20.

[0057] Furthermore, the clamp 210 includes a fixed portion 211 and a movable portion 212, and the fixed portion 211 and the movable portion 212 are arranged at intervals along the X direction. The fixed portion 211 is fixed on the base 100, and a receiving groove 213 for placing the battery 10 is provided on the side of the fixed portion 211 facing the movable portion 212. The first driving component 220 is installed on the base 100 and is transmission-connected to the movable portion 212. The first driving component 220 can drive the movable portion 212 to move toward the fixed portion 211 to fix the battery 10 in the receiving groove 213.

[0058] In this embodiment, the receiving groove 213 is arranged on the fixed part 211. After the battery 10 is placed in the receiving groove 213, the first driving component 220 drives the movable part 212 to move toward the fixed part 211, so that the movable part 212 abuts against the fixed part 211, and the battery 10 can be fixed in the receiving groove 213.

[0059] The shape of the receiving groove 213 matches the shape of the battery 10. The shape of the receiving groove 213 matches the shape of the square battery. The notch of the receiving groove 213 faces the movable part 212, and the side of the receiving groove 213 along the Y direction and the upper end along the Z direction are open structures. In this embodiment, by designing the side of the receiving groove 213 along the Y direction as an open structure, it is convenient to take and put the battery 10; by making the upper end of the receiving groove 213 along the Z direction an open structure, the top cover 11 of the battery 10 can be exposed, which is convenient for the pressing block 310 to press the sealing nail 20. The X direction, the Y direction, and the Z direction are perpendicular to each other.

[0060] Of course, for cylindrical batteries, the shape of the receiving groove 213 can also be designed to be similar to a cylindrical structure, and the details are not repeated here.

[0061] In this embodiment, the second driving assembly 320 is installed on the side of the fixed portion 211 away from the movable portion 212, and the pressing block 310 is located above the accommodating groove 213 along the Z direction and facing the sealing pin 20. The second driving assembly 320 can drive the pressing block 310 to move up and down.

[0062] After the battery 10 is placed in the receiving groove 213 and fixed by the clamp 210, the sealing nail 20 is placed in the injection hole, and then the second driving component 320 drives the pressing block 310 to move downward to press the sealing nail 20 on the top cover 11 of the battery 10. When the welding is completed, the second driving component 320 drives the pressing block 310 to move upward, and the welded battery 10 can be removed.

[0063] For example, Figure 1 As shown, the clamping mechanism 200 also includes a first guide portion 230, which is arranged at the bottom of the movable portion 212, and a second guide portion 400 is provided on the base 100 to cooperate with the first guide portion 230, and the length of the second guide portion 400 extends along the X direction. Among them, the first guide portion 230 is a slider, and the slider has a slide groove whose length extends along the X direction, and the second guide portion 400 is a slide rail whose length extends along the X direction. The slide rail is fixed on the base 100, and the first driving assembly 220 can drive the movable portion 212 to drive the slider to move along the slide rail. In other embodiments, the first guide portion 230 can also be designed as a slide rail, and the second guide portion 400 can be designed as a slider, and the guiding cooperation in the X direction can also be achieved.

[0064] Optionally, the first drive component 220 of the present embodiment includes a first cylinder 221 and a first piston rod 222, the first cylinder 221 is fixed on the base 100, and the first cylinder 221 is connected to the movable part 212 through the first piston rod 222; or, in other embodiments, the first drive component 220 includes a hydraulic cylinder and a piston rod, the hydraulic cylinder is fixed on the base 100, and the hydraulic cylinder is connected to the movable part 212 through the piston rod; or, the first drive component 220 can also be a linear motor and an output shaft, the linear motor is connected to the movable part 212 through the output shaft, and so on.

[0065] For example, Figure 2 and Figure 3 As shown, the clamping mechanism 300 further includes a third guide portion 330, an intermediate connector 340 and a fourth guide portion 350. The third guide portion 330 is connected to the pressing block 310 through the intermediate connector 340. The second driving assembly 320 is in transmission connection with the intermediate connector 340. The fourth guide portion 350 is provided on the side of the fixed portion 211 away from the movable portion 212 and is guided and matched with the third guide portion 330. The length of the fourth guide portion 350 extends along the Z direction. The third guide portion 330 is a slider having a slide groove extending along the Z direction. The fourth guide portion 350 is a slide rail extending along the Z direction. The slide rail is fixed on the side of the fixed portion 211 away from the movable portion 212. The second driving assembly 320 can drive the intermediate connector 340 to drive the third guide portion 330 and the pressing block 310 to move along the slide rail. In other embodiments, the third guide portion 330 can also be designed as a slide rail and the fourth guide portion 350 can be designed as a slider, and the guiding match in the Z direction can also be achieved.

[0066] Optionally, the second drive assembly 320 of this embodiment includes a linear motor 321 fixed on the fixed part 211 and an output shaft 322 connected to the linear motor 321, the output shaft 322 is connected to the third guide part 330 through an intermediate connecting piece 340, and the output shaft 322 is driven by the linear motor 321 to drive the third guide part 330 and the pressure block 310 to move up and down along the Z direction; in other embodiments, the second drive assembly 320 includes a second cylinder and a second piston rod, the second cylinder is fixed to a side of the fixed part 211 away from the movable part 212, and the second cylinder is connected to the third guide part 330 through the second piston rod; or, in other embodiments, the second drive assembly 320 includes a hydraulic cylinder and a piston rod, the hydraulic cylinder is fixed to a side of the fixed part 211 away from the third guide part 330, and the hydraulic cylinder is connected to the third guide part 330 through the piston rod, and so on.

[0067] Furthermore, if Figure 3As shown, the intermediate connecting member 340 includes a first connecting portion 341, a second connecting portion 342, a fifth guiding portion 343 and a sixth guiding portion 344. The first connecting portion 341 is connected to the second driving assembly 320 and the third guiding portion 330 respectively. The fifth guiding portion 343 is fixed on the side of the first connecting portion 341 facing the movable portion 212. The second connecting portion 342 is connected to the pressing block 310 and the sixth guiding portion 344 respectively. The lengths of the fifth guiding portion 343 and the sixth guiding portion 344 are both extended along the Y direction. The fifth guiding portion 343 and the sixth guiding portion 344 are guided and matched along the Y direction. The X direction, the Y direction and the Z direction are perpendicular to each other. Pushing the second connecting portion 342 along the Y direction can drive the pressing block 310 to move along the Y direction, and adjust the position of the pressing block 310 so that the avoidance hole 311 of the pressing block 310 is directly opposite to the sealing nail 20, and the area to be welded of the sealing nail 20 is completely exposed.

[0068] The fifth guide portion 343 is a slide rail, the length of which extends along the Y direction, and the sixth guide portion 344 is a slider having a slide groove, which slides with the slide rail. In other embodiments, the fifth guide portion 343 can also be designed as a slider having a slide groove, and the sixth guide portion 344 can be designed as a slide rail, which can also achieve position adjustment of the pressing block 310 along the Y direction.

[0069] Next, taking a square battery and a circular closed-loop contour line as an example, the battery sealing nail welding method of this embodiment is further described in detail.

[0070] Step 1: Draw the closed loop contour line 1. Spot welding points 2a-2d and the starting point of full welding: Figure 5 As shown, a circular closed-loop contour line 1 is drawn with the center of the sealing pin (circle) as the center, and then four welding points 2a-2d are drawn on the closed-loop contour line, among which welding point 2a and welding point 2b are centrally symmetrical, and welding point 2c and welding point 2d are centrally symmetrical; a symmetry line 3 is drawn on the closed-loop contour line 1 to make the welding points 2a-2d symmetrical relative to the symmetry line 3, and the two intersection points of the symmetry line 3 and the closed-loop contour line 1 are point A and point B respectively.

[0071] Step 2: Fix the battery 10 (square) and tighten the sealing nail 20: Figure 4 , place the battery 10 in the receiving groove 213 of the fixed part 211, and drive the movable part 212 toward the fixed part 211 through the first driving component 220 to fix the battery 10; then align the sealing nail 20 and place it in the injection hole, and drive the pressing block 310 to move downward through the second driving component 320 until the sealing nail 20 is pressed against the top cover 11 of the battery 10.

[0072] Step 3: Spot welding: Use laser welding according to Figure 5 The spot welding is performed in the order of the welding points 2a-2d shown in the figure, and the welding points 2a-2d are formed in sequence. Figure 6 Spot weld marks 4a-4d are shown.

[0073] Step 4: Full welding: Take point A and point B as the starting points of the two full welds, and use laser welding (two laser welding guns) to perform full welding in a clockwise direction along the contour lines of the two semicircles at the same time until the two full weld marks are butted end to end to form a closed loop (circular) full weld mark 5 ( Figure 7 ).

[0074] After welding is completed, the second driving assembly 320 drives the pressing block 310 to move upward and the first driving assembly 220 drives the movable portion 212 to move in a direction away from the fixed portion 211; the battery 10 is removed, and the sealing process of the liquid injection hole of the battery 10 is completed.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery sealing nail welding method, characterized in that: The following steps are involved: Fix the battery, put the sealing pin into the injection hole of the battery, and then press the sealing pin tightly, so that the area to be welded of the sealing pin is exposed; Spot welding is performed on the area to be welded of the sealing pin to form an even number of spot welding marks, where every two spot welding marks are symmetrical with respect to the center of the sealing pin, and all the spot welding marks have at least one symmetry line, and full welding is performed with two spaced-apart points A and B on the symmetry line as full welding starting points to form two sections of full welding marks, and the two sections of the full welding marks cover the spot welding marks, and the two sections of the full welding marks are butted end to end to form a closed loop.

2. The battery sealing nail welding method according to claim 1, characterized in that: When spot welding the sealing pin, a welding spot is determined and then spot welding is performed. After a spot welding mark is formed, the next welding spot which is centrally symmetrical with the spot welding mark is welded.

3. The battery sealing nail welding method according to claim 1, characterized in that: When spot welding the sealing pin, after determining two centrally symmetrical welding points, the two welding points are spot welded simultaneously.

4. The battery sealing nail welding method according to claim 1, characterized in that: The number of the spot welding marks is at least four.

5. The battery sealing nail welding method according to any one of claims 1 to 4, characterized in that: Before the sealing pin is placed in the liquid injection hole of the battery, a closed-loop contour line with the center of the sealing pin as the center is drawn on the end surface of the sealing pin away from the liquid injection hole, an even number of centrally symmetrical welding points and a symmetry line that makes all the welding points symmetrical are drawn at intervals on the closed-loop contour line, and the closed-loop contour line is divided into two symmetrical semi-closed-loop contour lines through the symmetry line, and the intersection points of the symmetry line and the closed-loop contour line are the point A and the point B.

6. The battery sealing nail welding method according to claim 5, characterized in that: The closed-loop contour line is a regular symmetrical figure.

7. A welding auxiliary tooling used in the battery sealing nail welding method according to any one of claims 1 to 6, characterized in that: The battery pack includes a base and a clamping mechanism and a pressing mechanism arranged on the base, wherein the clamping mechanism includes a clamp and a first driving component, wherein the first driving component is connected to the clamp and is used to drive the clamp to fix the battery; the pressing mechanism includes a pressing block and a second driving component, wherein the second driving component is connected to the pressing block and is used to drive the pressing block to press the sealing pin into the liquid injection hole of the battery; When the pressing block presses the sealing pin, the area to be welded of the sealing pin is exposed from the pressing block.

8. The welding auxiliary tooling according to claim 7, characterized in that: The pressing block is provided with an avoidance hole facing the sealing pin along the thickness direction thereof. When the pressing block presses the sealing pin, the area to be welded of the sealing pin is exposed from the avoidance hole.

9. The welding auxiliary tooling according to claim 7 or 8, characterized in that: The clamp includes a fixed part and a movable part, the fixed part and the movable part are arranged at intervals along the X direction, the fixed part is fixed on the base, and a receiving groove for placing the battery is provided on the side of the fixed part facing the movable part, the first driving component is installed on the base and is transmission-connected to the movable part, and the first driving component can drive the movable part to move toward the fixed part to fix the battery in the receiving groove.

10. The welding auxiliary tooling according to claim 9, characterized in that: The second driving assembly is installed on a side of the fixed portion away from the movable portion, the pressing block is located above the accommodating groove, and the second driving assembly can drive the pressing block to move up and down.

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