Welding equipment and welding method for cylindrical battery

Abstract

The invention relates to the technical field of battery manufacturing, in particular to welding equipment and a welding method for a cylindrical battery, and aims to solve the problem that in the prior art, metal particles generated by welding in a roll core cannot be removed under the condition that the welding strength is guaranteed. In order to achieve the purpose, the dust extraction system for cylindrical battery welding comprises a welding assembly, and the welding assembly is provided with a welding needle; the dust extraction assembly is connected with the welding assembly and provided with a dust extraction pipeline, and the dust extraction pipeline is arranged on the welding needle in a sleeving mode; wherein the welding pin extends into the cylindrical battery from a roll core of the cylindrical battery to weld a collector plate and a pole of the cylindrical battery, and the dust extraction pipeline sleeved on the welding pin is used for absorbing impurities generated in the welding process. Therefore, when the collector plate and the pole of the cylindrical battery are welded, the welding equipment can directly suck away metal particles generated by welding from the dust suction pipeline from the welding position of the collector plate and the pole, and the existing problems are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and particularly provides a welding device and a welding method for cylindrical batteries. Background Art

[0002] With the rapid development of the new energy vehicle industry, the market demand for lithium batteries has also shown an explosive growth. As the only power source of new energy vehicles, the safety and reliability of lithium batteries largely determine the performance of new energy vehicles. As a relatively common type of lithium battery, cylindrical batteries obtain electric energy through charging and provide electric energy to the object through discharging according to the usage requirements. They can be quickly charged and discharged in a short time and have the advantages of high charging efficiency and large output power.

[0003] Currently, the current collector plate under the cylindrical battery core and the pole column are usually welded by ultrasonic welding. During welding, the welding needle of the ultrasonic welding device penetrates into the battery core and contacts the current collector plate. The ultrasonic welding host starts welding, and the electric energy is converted into mechanical energy to generate low-amplitude mechanical vibration. Within the set welding time, the mechanical vibration is transmitted to the contact area between the current collector plate and the pole column, generating heat, causing the metal material to melt, and forming a weld after cooling.

[0004] Due to the existing cylindrical battery structure design (considering capacity, etc.), the inner diameter of the battery core is not designed to be very large, and at the same time, the depth of the battery core is relatively large. And under the condition of meeting the welding requirements, the diameter of the welding needle is not too small. As a result, there is not much space between the welding needle and the inside of the battery core to add a relatively complex dust extraction device. However, during the ultrasonic welding of the current collector plate under the cylindrical battery core and the pole column, if the device has no dust extraction function, the metal particles generated during welding will splash, easily causing the diaphragm of the battery core to be penetrated and damaged by the splashing metal particles. At the same time, these metal particles and other impurities also remain inside the battery core. After injection of the electrolyte, the diaphragm of the battery core may also be damaged secondarily, resulting in safety problems of the battery. In the prior art, in order to reduce the metal particles generated by welding, methods such as reducing the welding power are often used, but the welding strength is not very high in this case. Therefore, how to remove the metal particles generated by welding inside the battery core while ensuring the welding strength has become an urgent technical problem in this field.

[0005] In view of this, the field needs a new welding device and welding method for cylindrical batteries to solve the existing problems. Summary of the Invention

[0006] The present invention aims to solve the above technical problems, that is, to solve the problem that in the prior art, it is impossible to remove the metal particles generated by welding inside the battery core while ensuring the welding strength.

[0007] In a first aspect, the present invention provides a welding device for cylindrical batteries, comprising: a welding assembly having a welding needle; a dust extraction assembly connected to the welding assembly, the dust extraction assembly having a dust extraction pipeline sleeved on the welding needle; wherein, the welding needle extends into the cylindrical battery from the wound core to weld the current collector plate and the pole of the cylindrical battery, and the dust extraction pipeline sleeved on the welding needle is used to absorb impurities generated during the welding process.

[0008] In a specific embodiment of the above welding device for cylindrical batteries, the welding assembly includes a first driving member connected to the welding needle, and the first driving member can drive the welding needle to reciprocate in a first direction.

[0009] In a specific embodiment of the above welding device for cylindrical batteries, the dust extraction assembly further includes: a negative pressure source for providing negative pressure to the dust extraction system; a three-way adapter that divides the dust extraction pipeline into a first pipeline section and a second pipeline section; one end of the first pipeline section is connected to the negative pressure source, and the other end is connected to the first end of the three-way adapter, one end of the second pipeline section is connected to the third end of the three-way adapter, and the other end extends into the welding area between the current collector plate and the pole; the welding needle enters from the second end of the three-way adapter, passes through the third end of the three-way adapter and enters the interior of the second pipeline section, and extends into the welding area between the current collector plate and the pole together with the second pipeline section.

[0010] In a specific embodiment of the above welding device for cylindrical batteries, the welding assembly further includes a welding bracket, the welding needle is fixedly arranged on the welding bracket, and the welding bracket can move along the axial direction of the cylindrical battery; the dust extraction assembly further includes a connecting member, a first clamping block and a second clamping block, the first clamping block and the second clamping block are respectively arranged on both sides of the three-way adapter and can clamp and fix the three-way adapter from both sides, and one end of the connecting member is connected to the welding bracket, and the other end is connected to the first clamping block and / or the second clamping block.

[0011] In a specific embodiment of the above welding device for cylindrical batteries, a second driving member is arranged on the welding bracket, the second driving member can move relative to the welding bracket along the first direction of the cylindrical battery, and the connecting member is fixedly connected to the second driving member.

[0012] In a specific embodiment of the above welding device for cylindrical batteries, a switch valve is arranged on the dust extraction pipeline to control the on / off of the dust extraction pipeline, and / or, a speed regulating valve is arranged on the dust extraction pipeline to adjust the flow rate of the air flow in the dust extraction pipeline.

[0013] In the above specific implementation manner of the welding device for cylindrical batteries, an air pipe joint is provided at the first end of the three-way adapter. A first sealing ring is provided at the connection between the air pipe joint and the first end of the three-way adapter. The first pipe section is connected to the first end of the three-way adapter through the air pipe joint.

[0014] In the above specific implementation manner of the welding device for cylindrical batteries, a second sealing ring is provided between the second pipe section and the third end of the three-way adapter. The second pipe section and the third end of the three-way adapter are fixed by fastening screws.

[0015] In the above specific implementation manner of the welding device for cylindrical batteries, a third sealing ring is provided between the welding needle and the second end of the three-way adapter. A sealing ring cover plate for fixing the third sealing ring is further provided at the second end of the three-way adapter. The third sealing ring is made of silicone material or fluororubber material.

[0016] In the above specific implementation manner of the welding device for cylindrical batteries, the negative pressure source is a dust collector or a vacuum pump and a filter, and / or, the second driving member is one of a slide cylinder, a hydraulic cylinder, and a ball screw, and / or, the material of the dust extraction pipeline and the three-way adapter is anti-static PEEK or anti-static POM.

[0017] The present invention also provides a welding method for cylindrical batteries, including the welding device for cylindrical batteries according to any one of the above technical solutions. The welding method includes: determining that the cylindrical battery is fixedly installed in place; controlling the welding needle of the welding assembly to penetrate into the core of the cylindrical battery to weld the pole column and the current collector core; determining that the welding is completed; controlling the dust extraction assembly to extract dust from the welding part of the pole column and the current collector.

[0018] The technical effect of the present invention is that by sleeving the dust extraction pipeline outside the welding needle and extending it into the welding part of the current collector and the pole column together with the welding needle, when welding the current collector and the pole column, the dust extraction assembly of the present invention can timely extract the metal particles generated during the welding process from the welding part through the dust extraction pipeline, which not only ensures the welding strength but also avoids the splashing of the metal particles generated during welding, causing the core diaphragm to be penetrated and damaged by the splashed metal particles, and these metal particles and other impurities also remain inside the core. After injection, it may cause secondary damage to the core diaphragm, resulting in safety problems of the battery and other situations. It solves the problem in the prior art that it is impossible to remove the metal particles generated by welding inside the core while ensuring the welding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following describes the preferred embodiments of the present invention with reference to the drawings, in which:

[0020] Figure 1 In an embodiment of the present invention, it is a schematic diagram of the overall structure of a cylindrical battery, a welding assembly, and a dust extraction assembly;

[0021] Figure 2 In an embodiment of the present invention, it is a front view of the connection relationship between the welding assembly and the dust extraction assembly;

[0022] Figure 3 In an embodiment of the present invention, it is a sectional view of the welding assembly and the dust extraction assembly;

[0023] Figure 4 In an embodiment of the present invention, it is a connection relationship diagram of a tracheal joint, a welding needle, and a second pipe section with the first end, the second end, and the third end of a three-way adapter respectively;

[0024] Figure 5 In an embodiment of the present invention, it is a partially enlarged view of the positional relationship between the welding needle and the second pipe section inside the cylindrical battery;

[0025] Figure 6 In an embodiment of the present invention, it is a schematic diagram of the structure of the welding needle and the second pipe section inside the three-way adapter;

[0026] Figure 7 In an embodiment of the present invention, it is a schematic diagram of a negative pressure source, a first pipe section, and a valve on the first pipe section;

[0027] Figure 8 In an embodiment of the present invention, it is a flowchart of a welding method for a cylindrical battery;

[0028] Figure 9 In another embodiment of the present invention, it is a flowchart of a welding method for a cylindrical battery.

[0029] List of reference numerals:

[0030] 1. Welding assembly;

[0031] 1-1. Welding needle; 1-2. Welding bracket;

[0032] 2. Dust extraction assembly;

[0033] 2-1. Connector; 2-2. First clamping block; 2-3. Second clamping block; 2-4. Third sealing ring; 2-5. Tracheal joint; 2-6. Three-way adapter; 2-61. First end; 2-62. Second end; 2-63. Third end; 2-7. Second sealing ring; 2-8. Second pipe section; 2-9. Fastening screw; 2-10. Second driving member; 2-11. Sealing ring cover plate; 2-12. Negative pressure source; 2-13. First pipe section; 2-14. Switch valve; 2-15. Speed control valve;

[0034] 3. Fixing mechanism;

[0035] 4. Cylindrical battery;

[0036] 4-1. Core; 4-2. Current collector plate; 4-3. Terminal post. Specific embodiments

[0037] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0038] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] First, the problems existing in the welding process of the existing cylindrical battery will be described.

[0041] Due to the existing cylindrical battery structure design (taking into account capacity, etc.), the inner diameter of the core will not be designed to be very large, and the core depth is relatively large; and the diameter of the welding needle will not be too small while meeting the welding requirements; thus, there is not much space between the welding needle and the inside of the core to add a more complex dust extraction device. However, during the ultrasonic welding of the collector plate and the pole under the cylindrical battery core, if the equipment does not have a dust extraction function, the metal particles generated during welding will splash, which can easily cause the core diaphragm to be penetrated and damaged by the splashed metal particles; at the same time, these metal particles and other impurities also remain inside the core. After injection, the core diaphragm may also be damaged for the second time, causing safety problems for the battery. In order to reduce the metal particles generated by welding in the prior art, methods such as reducing the welding power are often used. In this way, the welding strength will not be very large, which will cause the stability of the battery structure to deteriorate and reduce the service life of the battery. Therefore, how to remove the metal particles generated by welding inside the core while ensuring the welding strength has become a technical problem that needs to be solved urgently in this field.

[0042] like Figures 1-7 As shown, the fixing mechanism 3 is arranged at the bottom, and the cylindrical battery 4 is placed on the fixing mechanism 3. The cylindrical battery 4 includes a winding core 4-1, a current collecting plate 4-2 and a pole 4-3. The welding mentioned in the present invention is to weld the connection between the current collecting plate 4-2 and the pole 4-3. The welding assembly 1 is at the top, and the welding assembly 1 includes a welding needle 1-1, a welding bracket 1-2 and a first driving member (not shown in the figure). The welding needle 1-1 is fixedly arranged on the welding bracket 1-2. The welding bracket 1-2 can be driven by the first driving member along a first direction (i.e. Figure 1 The axial direction of the cylindrical battery 4 (as indicated by the middle arrow) moves back and forth up and down, so that the welding needle 1-1 can be driven by the welding bracket 1-2 to extend into the winding core 4-1 of the cylindrical battery 4 and weld the connection between the collecting plate 4-2 and the pole 4-3.

[0043] In order to solve the problem in the prior art that metal particles generated by welding inside the winding core 4-1 cannot be removed while ensuring welding strength, the present invention proposes a dust extraction component 2 for welding cylindrical batteries 4, and the dust extraction component 2 includes:

[0044] Negative pressure source 2-12, used to provide negative pressure for the dust extraction component 2, the negative pressure source 2-12 can be a dust collector or a vacuum pump with a filter, etc.;

[0045] The dust extraction pipeline includes a first pipeline section 2-13 and a second pipeline section 2-8. The first pipeline section 2-13 and the second pipeline section 2-8 are connected at a tee adapter 2-6 provided on the dust extraction pipeline. One end of the first pipeline section 2-13 is connected to a negative pressure source 2-12, and the other end is connected to the first end 2-61 of the tee adapter 2-6. One end of the second pipeline section 2-8 is connected to the third end 2-63 of the tee adapter 2-6, and the other end extends through the core 4-1 of the cylindrical battery 4 to the welding joint of the current collector plate 4-2 and the terminal 4-3. The welding needle 1-1 enters from the second end 2-62 of the tee adapter 2-6, passes through the third end 2-63 of the tee adapter 2-6 and enters the interior of the second pipeline section 2-8, and extends to the welding joint of the current collector plate 4-2 and the terminal 4-3 together with the second pipeline section 2-8. There is a gap between the inner side wall of the second pipeline section 2-8 and the welding needle 1-1, and there is a gap between the outer side wall of the second pipeline section 2-8 and the core 4-1.

[0046] A connecting piece 2-1, a first clamping block 2-2 and a second clamping block 2-3. The first clamping block 2-2 and the second clamping block 2-3 are respectively arranged on both sides of the tee adapter 2-6 and can clamp and fix the tee adapter 2-6 from both sides. One end of the connecting piece 2-1 is connected to the welding bracket 1-2, and the other end is connected to the first clamping block 2-2, so as to realize the connection between the tee adapter 2-6 and the welding bracket 1-2. In addition, the other end of the connecting piece 2-1 can also be connected to the second clamping block 2-3, or connected to both the first clamping block 2-2 and the second clamping block 2-3 at the same time, as long as the connection between the welding bracket 1-2 and the tee adapter 2-6 can be realized.

[0047] A switching valve 2-14 and a speed regulating valve 2-15. The switching valve 2-14 and the speed regulating valve 2-15 are both arranged on the first pipeline section 2-13. The switching valve 2-14 can be a solenoid valve for controlling the on-off of the dust extraction pipeline, and the speed regulating valve 2-15 is used to adjust the flow rate of the air flow in the dust extraction pipeline. In addition, the switching valve 2-14 and the speed regulating valve 2-15 can also be arranged on the second pipeline section 2-8, as long as the corresponding functions can be realized.

[0048] In the case of adopting the above-mentioned implementation manner, during the welding process of the cylindrical battery 4, first, the welding bracket 1-2 is controlled to move towards the welding position, simultaneously driving the welding needle 1-1, the tee adapter 2-6, and the second pipe section 2-8 connected to the tee adapter 2-6 to move towards the welding position until the welding needle 1-1 contacts the welding position. At this time, there is still a certain gap between the end of the second pipe section 2-8 and the welding position for ventilation. Then, the negative pressure source 2-12 and the switch valve 2-14 are opened, and air enters the welding position of the current collector plate 4-2 and the pole 4-3 from the outside through the gap between the outer sidewall of the second pipe section 2-8 and the battery core 4-1, and passes through the gap between the end of the second pipe section 2-8 and the welding position into the gap between the inner sidewall of the second pipe section 2-8 and the welding needle 1-1. Then, it passes through the second pipe section 2-8, enters the tee adapter 2-6 through the third end 2-63 of the tee adapter 2-6, and then enters the first pipe section 2-13 through the first end 2-61 of the tee adapter 2-6, and is then extracted by the negative pressure source 2-12. During this process, when the air flows through the welding position, it can take away the metal particles at the welding position, thereby realizing the cleaning of the metal particles at the welding position. In addition, if it is found that the dust extraction force is insufficient during the dust extraction process, the dust extraction force in the dust extraction pipeline can also be adjusted by the speed control valve 2-15 to meet the dust extraction requirements. In addition, the materials of the dust extraction pipeline and the tee adapter 2-6 can be selected as anti-static PEEK or anti-static POM.

[0049] The advantages of the above-mentioned implementation manner are as follows: By setting the tee adapter 2-6 on the dust extraction pipeline, the scheme of arranging the welding needle 1-1 inside the second pipe section 2-8 is realized, so that the metal particles generated during the welding process can be extracted through the gap between the inner sidewall of the second pipe section 2-8 and the welding needle 1-1. At the same time, since the space inside the core 4-1 is relatively small, it is not easy to implement the scheme of arranging the dust extraction pipeline side by side beside the welding needle 1-1. However, the nested setting method proposed in this scheme can significantly reduce the space occupied by the dust extraction pipeline, so there is no need to reduce the generation of metal particles by reducing the welding power as in the prior art. Furthermore, on the premise of ensuring the welding strength, the metal particles generated during the welding inside the core 4-1 are removed, solving the existing problems.

[0050] In the foregoing implementation manner, it is mentioned that the welding needle 1-1 and the second pipe section 2-8 can be moved to the welding position together through the welding bracket 1-2, thereby realizing dust extraction while welding. However, the metal particles generated during the welding process may be squeezed between the welding needle 1-1 and the current collector plate 4-2 and cannot be extracted. Therefore, as Figure 2As shown, in a preferred embodiment, a second driving member 2-10 is provided on the welding bracket 1-2. The second driving member 2-10 can move relative to the welding bracket 1-2 along the axial direction of the cylindrical battery 4. The connecting member 2-1 is fixedly connected to the second driving member 2-10. The second driving member 2-10 can be one of a slide cylinder, a hydraulic cylinder, and a ball screw.

[0051] In the case of adopting the above embodiment, since a second driving member 2-10 is separately provided for the dust extraction assembly 2, on the one hand, the welding bracket 1-2 can transport the welding needle 1-1 and the dust extraction assembly 2 to the first position together, and then the second driving member 2-10 can separately transport the dust extraction assembly 2 to the second position to achieve the functions of rough positioning and fine positioning; on the other hand, after welding is completed, the welding bracket 1-2 can be controlled to move the welding needle 1-1 and the second pipe section 2-8 upward by a certain distance to make the metal particles extruded between the welding needle 1-1 and the current collector plate 4-2 fall off, and then the second driving member 2-10 can be controlled to move the second pipe section 2-8 downward to the welding position to further process the fallen metal particles, improving the dust extraction effect of the dust extraction assembly 2.

[0052] In addition, when using the negative pressure source 2-12 for dust extraction, the airtightness requirement for the pipeline is relatively high. Therefore, as Figure 3 、 Figure 6 shown, in a preferred embodiment, an air pipe joint 2-5 is provided at the first end 2-61 of the three-way adapter 2-6. A first sealing ring (not shown in the figure) is provided at the connection between the air pipe joint 2-5 and the first end 2-61 of the three-way adapter 2-6. The first pipe section 2-13 is connected to the first end 2-61 of the three-way adapter 2-6 through the air pipe joint 2-5. A second sealing ring 2-7 is provided between the second pipe section 2-8 and the third end 2-63 of the three-way adapter 2-6. The second pipe section 2-8 and the third end 2-63 of the three-way adapter 2-6 are fixed by fastening screws 2-9. A third sealing ring 2-4 is provided between the welding needle 1-1 and the second end 2-62 of the three-way adapter 2-6. A sealing ring cover plate 2-11 for fixing the third sealing ring 2-4 is also provided at the second end 2-62 of the three-way adapter 2-6. The third sealing ring 2-4 is made of silica gel material or fluororubber material.

[0053] The advantages of the above-described embodiments are as follows: By providing the first sealing ring, the second sealing ring 2-7, and the third sealing ring 2-4, the sealing between the tee adapter 2-6 and the first pipe section 2-13, the second pipe section 2-8, and the welding needle 1-1 is achieved, thereby ensuring the airtightness of the dust extraction pipeline. Additionally, as mentioned in the background art, the current collector plate 4-2 and the pole 4-3 below the cylindrical battery 4 core 4-1 are usually ultrasonically welded. The principle of ultrasonic welding is to convert electrical energy into mechanical energy and generate low-amplitude mechanical vibrations. That is, the welding efficiency of the welding needle 1-1 is related to the vibration condition of the welding needle 1-1. Therefore, in order to avoid the excessive contact between the third sealing ring 2-4 and the welding needle 1-1 from affecting the welding efficiency of the welding needle 1-1, in this embodiment, the third sealing ring 2-4 is preferably made of a relatively soft silicone material or fluororubber material. In addition, those skilled in the art can also select other relatively soft materials as the third sealing ring 2-4.

[0054] In addition, the present invention also provides a welding method for welding a cylindrical battery 4, as Figure 8 shown, the welding method includes:

[0055] SA. Determine that the cylindrical battery is fixedly installed in place;

[0056] SB. Control the welding needle of the welding assembly to penetrate into the core of the cylindrical battery to weld the pole and the current collector plate core;

[0057] SC. Determine that the welding is completed;

[0058] SD. Control the dust extraction assembly to extract dust from the welding area of the pole and the current collector plate.

[0059] The advantages of the above-described embodiments are as follows: By providing the dust extraction assembly 2, after the welding assembly 1 completes the welding of the pole 4-3 and the current collector plate 4-2, the metal particles generated at the welding area can be directly extracted, solving the problem in the prior art that it is impossible to remove the metal particles generated due to welding inside the core while ensuring the welding strength.

[0060] Furthermore, the present invention also provides a welding method for welding a cylindrical battery 4, as Figures 1-7 、 Figure 9 shown, including: a cylindrical battery 4, the cylindrical battery 4 including a core 4-1, a current collector plate 4-2, and a pole 4-3; a welding assembly 1, including a welding needle 1-1, the welding needle 1-1 being able to extend into the core 4-1 of the cylindrical battery 4 to weld the current collector plate 4-2 and the pole 4-3;

[0061] The dust extraction assembly 2 includes: a negative pressure source 2-12 for providing negative pressure for the dust extraction assembly 2; a dust extraction pipeline, one end of which is communicated with the negative pressure source 2-12, and the other end is sleeved outside the welding needle 1-1, extends into the welding part of the current collector plate 4-2 and the pole column 4-3 through the core 4-1 of the cylindrical battery 4. There is a gap between the inner side wall of the dust extraction pipeline and the welding needle 1-1, so that impurities generated during the welding process can be drawn away from the dust extraction pipeline through this gap; a tee adapter 2-6 is arranged on the dust extraction pipeline, and the tee adapter 2-6 divides the dust extraction pipeline into a first pipeline section 2-13 and a second pipeline section 2-8; one end of the first pipeline section 2-13 is communicated with the negative pressure source 2-12, and the other end is communicated with the first end 2-61 of the tee adapter 2-6. One end of the second pipeline section 2-8 is communicated with the third end 2-63 of the tee adapter 2-6, and the other end extends into the welding part of the current collector plate 4-2 and the pole column 4-3; the welding assembly 1 further includes a welding bracket 1-2, one end of the welding needle 1-1 is fixedly arranged on the welding bracket 1-2, and the other end enters from the second end 2-62 of the tee adapter 2-6, passes through the third end 2-63 of the tee adapter 2-6 and enters the inside of the second pipeline section 2-8, and extends into the welding part of the current collector plate 4-2 and the pole column 4-3 together with the second pipeline section 2-8. The welding bracket 1-2 can move along the axial direction of the cylindrical battery 4, and a second driving member 2-10 is arranged on the welding bracket 1-2, and the second driving member 2-10 can move along the axial direction of the cylindrical battery 4 relative to the welding bracket 1-2; the dust extraction assembly 2 further includes a connecting member 2-1, a first clamping block 2-2 and a second clamping block 2-3. The first clamping block 2-2 and the second clamping block 2-3 are respectively arranged on both sides of the tee adapter 2-6 and can clamp and fix the tee adapter 2-6 from both sides. One end of the connecting member 2-1 is fixedly connected with the second driving member 2-10, and the other end is connected with the first clamping block 2-2; a switch valve 2-14 is arranged on the dust extraction pipeline for controlling the on-off of the dust extraction pipeline.

[0062] The welding method includes:

[0063] S1. Control the welding bracket to move a first preset distance along the axial direction of the cylindrical battery towards the direction close to the current collector plate, so that the welding needle contacts the current collector plate and there is a gap between the second pipeline section and the current collector plate;

[0064] S2. Control the welding assembly to weld the current collector plate and the pole column through the welding needle and control the switch valve to open;

[0065] S3. Obtain the welding state of the current collector plate and the pole column and judge whether the welding is completed;

[0066] S4. If the current collector plate and the pole column are welded, control the welding assembly to stop welding the current collector plate and the pole column and control the switch valve to close;

[0067] S5. Control the welding bracket to move axially along the cylindrical battery away from the current collector plate by a second preset distance;

[0068] S6. Control the second driving member to move axially along the cylindrical battery towards the current collector plate so that the distance between the end of the second pipe section and the current collector plate is a third preset distance;

[0069] S7. Control the switching valve to open;

[0070] S8. Obtain the duration of the opening of the switching valve and determine whether it reaches the preset time;

[0071] S9. If the duration of the opening of the switching valve reaches the preset time, control the switching valve to close;

[0072] S10. Control the welding bracket to move axially along the cylindrical battery away from the current collector plate by a fourth preset distance.

[0073] In the case of adopting the above implementation, before starting welding, first control the welding bracket 1-2 to move axially along the cylindrical battery 4 towards the current collector plate 4-2 by a first preset distance, so that the welding needle 1-1 contacts the current collector plate 4-2 and there is a gap between the end of the second pipe section 2-8 and the current collector plate 4-2. Then control the welding assembly 1 to weld the current collector plate 4-2 and the pole 4-3 through the welding needle 1-1 and control the switching valve 2-14 to open to extract dust from the welding area. By obtaining the welding state of the current collector plate 4-2 and the pole 4-3, it is judged whether the welding is completed. If the current collector plate 4-2 and the pole 4-3 are welded, control the welding assembly 1 to stop welding the current collector plate 4-2 and the pole 4-3 and control the switching valve 2-14 to close to stop dust extraction. Thus, the first stage of the welding and dust extraction process is completed. Then control the welding bracket 1-2 to move axially along the cylindrical battery 4 away from the current collector plate 4-2 by a second preset distance, so that the welding needle 1-1 is separated from the current collector plate 4-2 and maintains a certain distance, and at the same time, the metal particles extruded between the welding needle 1-1 and the current collector plate 4-2 are exposed. Then control the second driving member 2-10 to move axially along the cylindrical battery 4 towards the current collector plate 4-2 so that the distance between the end of the second pipe section 2-8 and the current collector plate 4-2 is a third preset distance. Then open the switching valve 2-14 to perform secondary dust extraction on the metal particles at the welding area, obtain and judge whether the duration of the opening of the switching valve 2-14 reaches the preset time. If it reaches the preset time, control the switching valve 2-14 to close. Then control the welding bracket 1-2 to move axially along the cylindrical battery 4 away from the current collector plate 4-2 by a fourth preset distance. Finally, close the welding assembly 1 and the negative pressure source 2-12. Thus, the entire welding and dust extraction process is completed.

[0074] The advantages of the above-described embodiments are as follows: In the first stage of welding dust extraction, dust is extracted through the dust extraction pipeline while welding, and the metal particles generated during the welding process are extracted through the gap between the welding needle 1-1 and the second pipe section 2-8 of the dust extraction pipeline. Since metal particles are also generated between the current collecting plate 4-2 and the welding needle 1-1 during the welding process, and these metal particles are squeezed between the welding needle 1-1 and the current collecting plate 4-2. Therefore, when the first stage of welding dust extraction is completed, there will still be some metal particles that cannot be extracted at the welding point. At this time, the second stage of welding dust extraction is entered. In the second stage of welding dust extraction, the welding needle 1-1 and the second pipe section 2-8 are lifted upward by a certain distance to make the metal particles between the welding needle 1-1 and the current collecting plate 4-2 fall off, and then the second driving member 2-10 lowers the second pipe section 2-8 downward to a certain distance from the welding point to extract the remaining metal particles. Thus, by performing dust extraction twice during the welding process and after welding is completed, thorough removal of the metal particles generated during welding is achieved.

[0075] It should be noted that the above-described embodiments are only used to illustrate the principle of the present invention and are not intended to limit the protection scope of the present invention. Without departing from the principle of the present invention, those skilled in the art can adjust the above structure so that the present invention can be applied to more specific application scenarios.

[0076] Those skilled in the art can understand that the above-described welding equipment also includes some other well-known structures, such as a processor, a controller, a memory, etc. Among them, the memory includes but is not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory, or registers, etc. The processor includes but is not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. To avoid unnecessarily obscuring the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0077] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A welding device for cylindrical batteries, characterized in that, Comprising: A welding assembly having welding needles; A dust extraction assembly connected to the welding assembly, the dust extraction assembly having a dust extraction pipeline which is sleeved on the welding needles; Wherein, the welding needles extend from the winding core of the cylindrical battery into the current collector plate and the pole of the cylindrical battery for welding, and the dust extraction pipeline sleeved on the welding needles is used to absorb impurities generated during the welding process.

2. The welding device for cylindrical batteries according to claim 1, characterized in that, The welding assembly includes a first driving member connected to the welding needles, and the first driving member can drive the welding needles to reciprocate in a first direction.

3. The welding device for cylindrical batteries according to claim 2, characterized in that, The dust extraction assembly further includes: A negative pressure source for providing negative pressure for the dust extraction system; A three-way adapter which divides the dust extraction pipeline into a first pipeline section and a second pipeline section; One end of the first pipeline section is communicated with the negative pressure source, and the other end is communicated with the first end of the three-way adapter. One end of the second pipeline section is communicated with the third end of the three-way adapter, and the other end extends into the welding area between the current collector plate and the pole; The welding needles enter from the second end of the three-way adapter, pass through the third end of the three-way adapter and enter the interior of the second pipeline section, and extend into the welding area between the current collector plate and the pole together with the second pipeline section.

4. The welding device for cylindrical batteries according to claim 3, characterized in that, The welding assembly further includes a welding bracket, the welding needles are fixedly arranged on the welding bracket, and the welding bracket can move along the first direction of the cylindrical battery; The dust extraction assembly further includes a connecting member, a first clamping block and a second clamping block. The first clamping block and the second clamping block are respectively arranged on both sides of the three-way adapter and can clamp and fix the three-way adapter from both sides. One end of the connecting member is connected to the welding bracket, and the other end is connected to the first clamping block and / or the second clamping block.

5. The welding device for cylindrical batteries according to claim 3, characterized in that, A second driving member is arranged on the welding bracket, and the second driving member can move along the first direction of the cylindrical battery relative to the welding bracket. The connecting member is fixedly connected to the second driving member.

6. The welding device for cylindrical batteries according to any one of claims 1-4, characterized in that, A switching valve is arranged on the dust extraction pipeline for controlling the on / off of the dust extraction pipeline, and / or, A flow control valve is arranged on the dust extraction pipeline for adjusting the flow rate of the air flow in the dust extraction pipeline.

7. The welding device for cylindrical batteries according to any one of claims 3-4, characterized in that, An air pipe joint is arranged at the first end of the three-way adapter, and a first sealing ring is arranged at the connection between the air pipe joint and the first end of the three-way adapter. The first pipeline section is connected to the first end of the three-way adapter through the air pipe joint.

8. The welding device for cylindrical batteries according to any one of claims 3-4, characterized in that, A second sealing ring is arranged between the second pipeline section and the third end of the three-way adapter, and the second pipeline section and the third end of the three-way adapter are fixed by fastening screws.

9. The welding device for cylindrical batteries according to any one of claims 3-4, characterized in that, A third sealing ring is arranged between the welding needles and the second end of the three-way adapter. A sealing ring cover plate for fixing the third sealing ring is further arranged at the second end of the three-way adapter. The third sealing ring is made of silicone material or fluororubber material.

10. The welding device for cylindrical batteries according to claim 5, characterized in that, The negative pressure source is a dust collector or a vacuum pump and a filter, and / or, The second driving member is one of a slide cylinder, a hydraulic cylinder, and a ball screw, and / or, The materials of the dust extraction pipeline and the tee adapter are antistatic PEEK or antistatic POM.

11. A welding method for cylindrical batteries, characterized in that, Including the welding equipment for cylindrical batteries according to any one of claims 1-10, the welding method includes: Determine that the cylindrical battery is fixedly installed in place; Control the welding needle of the welding component to penetrate into the core of the cylindrical battery to weld the pole column and the current collector core; Determine that the welding is completed; Control the dust extraction component to extract dust from the welding area of the pole column and the current collector.

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