Cylindrical lithium battery laser welding tool

Abstract

The application relates to the technical field of battery production and manufacturing, and discloses a cylindrical lithium battery laser welding tool, which comprises a welding frame, a telescopic arm is slidably arranged on the outer side of the welding frame, a pressing plate is fixedly arranged at the bottom of the telescopic arm, a load resistor is movably arranged at the bottom of the pressing plate, wires are fixedly arranged at the two ends of the load resistor, and a contact rod is fixedly arranged at the end of each wire, away from the load resistor. The load resistor is connected in series to detect the internal resistance value of the battery plate to determine whether the welding point is false welding. The detection requirement is met, the false welding of the welding point can be more accurately determined, the CCD camera does not need to be continuously shot for a long time, the image quality of the CCD camera is prevented from being affected due to long-time continuous shooting, detection failure is avoided, the service life of the CCD camera is prolonged, and the stability and reliability of the whole lithium battery assembling process are improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery production and manufacturing, and particularly relates to a cylindrical lithium battery laser welding tool. BACKGROUND

[0002] In the core link of industrial production and precise assembly of lithium battery packs, an operator needs to follow strict technical specifications to realize electrical series connection or parallel connection of multiple single battery plates through high-precision battery connecting pieces. In this process, defects of a single welding point may cause safety hazards such as imbalance of internal resistance of the battery pack, local overheating and thermal runaway. In order to ensure that the welding quality meets the standards, a CCD (charge coupled device) industrial camera based on machine vision is generally used for welding point detection on the production line. The system captures key parameters such as welding pool shape, weld width and surface finish through a high-resolution lens, and automatically compares the preset standard with the help of an image processing algorithm to accurately identify defects such as false welding, missed welding and solder splashing.

[0003] However, when the CCD camera is in a long-time continuous shooting mode, the CMOS sensor inside the CCD camera will produce a thermal accumulation effect due to continuous light exposure, which will significantly increase the dark current noise, directly weakening the dynamic range and signal-to-noise ratio of the image. At the same time, high-frequency exposure will cause fatigue deformation of the mechanical shutter or electronic shutter system, causing mechanical failures such as focus drift or shutter jam. The LED ring light source running at a high power for a long time will also produce thermal radiation interference, forming a hot halo effect on the surface of the lens, causing image edge blur and color temperature drift. After the superposition of these factors, not only the service life of the key components of the camera (such as the image sensor and cooling fan) will be shortened, but also the detection system may have an increased misjudgment rate: a welding point that meets the standard may be incorrectly marked as false welding, resulting in unnecessary rework or waste, while a welding point with hidden defects may be missed due to image distortion, affecting production quality and ultimately affecting the quality certification and safety performance of the entire battery pack. SUMMARY

[0004] The application provides a cylindrical lithium battery laser welding tool, which can accurately determine whether a welding point has false welding, avoid the influence of long-time continuous shooting of a CCD camera on image quality and detection errors, prolong the service life of the CCD camera, and improve the stability and reliability of the entire lithium battery assembly process, so as to solve the problem of quality certification and safety performance caused by the increase of the misjudgment rate of the detection system due to long-time continuous shooting of the CCD camera during the production of lithium battery packs.

[0005] In order to achieve the above object, the following technical scheme is adopted: a cylindrical lithium battery laser welding tool, comprising a welding frame, a telescopic arm slidingly installed on the outer side of the welding frame, a pressing plate fixedly installed at the bottom of the telescopic arm, a load resistor movably installed at the bottom of the pressing plate, wires fixedly installed at both ends of the load resistor, contact rods fixedly installed at the ends of the two wires away from the load resistor, the contact rods being in contact with battery connecting pieces after the pressing plate moves downward, the load resistor and the battery plate after welding forming a series circuit, a detection circuit being arranged on the series circuit for detecting the voltage at both ends of the load resistor and the battery plate, a battery plate internal resistance feedback control system being used for judging whether the battery plate internal resistance is abnormal, and if abnormal, a CCD camera being started to detect the welding spot quality.

[0006] Further, one side of the pressing plate is fixedly installed with a connecting plate, and the length of the connecting plate is the same as the distance between the two battery connecting pieces on the battery plate, so as to provide support and protection for one of the wires.

[0007] Further, an installation column is fixedly installed on the inner side wall of the welding hole on the pressing plate, installation grooves are arranged at the bottom of the connecting plate and the installation column, a limiting plate is slidingly installed in the installation grooves, a tension spring is fixedly installed at the bottom of the limiting plate, and the limiting plate and the tension spring are sleeved on the outer side of the contact rod, and the top end of the tension spring is fixedly connected with the inner bottom wall of the installation groove, so as to ensure the stable fit between the contact rod and the battery connecting piece.

[0008] Further, an activity groove is arranged at the bottom of the pressing plate, a connecting column is movably installed in the activity groove, a rotating rod is fixedly installed at the ends of the two connecting columns away from the telescopic arm, a torsion spring is sleeved on the outer side of the rotating rod, fixed rings are fixedly installed at the ends of the two connecting columns close to the telescopic arm, a pressing column is fixedly installed between the two fixed rings, and the load resistor is arranged in the pressing column.

[0009] Further, two slide columns are symmetrically fixedly installed at the top of the end of the pressing plate away from the telescopic arm, a slide rod is slidingly installed at the bottom of the slide column, a spring is fixedly installed between the top end of the slide rod and the inner top wall of the slide column, a stable plate is movably penetrated through the pressing plate and fixedly installed at the bottom end of the slide rod, a limiting groove matched with the stable plate is arranged at the top of the pressing plate, so as to provide a space for the stable plate.

[0010] The present application has the following beneficial effects:

[0011] The cylindrical lithium battery laser welding tool provided by the application is used for welding the battery connecting piece, the pressing plate drives the contact rod to move downward, the contact rod touches the battery connecting piece at both ends of the battery plate, and then the load resistor is connected in series with the battery plate after welding, the voltage division of the load resistor and the electromotive force of the battery plate are measured through the related instrument, the resistance value of the battery plate is deduced combined with the known resistance value of the load resistor, and the standard value is compared, and then it is judged whether the virtual welding occurs, the internal resistance value of the battery plate is detected through the series connection of the load resistor to judge whether the welding point is virtually welded, not only the detection requirement is completed, but also whether the welding point is virtually welded can be more accurately judged, and the CCD camera does not need to be continuously shot for a long time, the image quality of the CCD camera is avoided from being affected due to the long-time continuous shooting, the detection failure is avoided, the service life of the CCD camera is prolonged, and the stability and reliability of the whole lithium battery assembly process are improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only belong to the embodiments of the application, and the drawings provided by the application can also be obtained by the ordinary skilled in the art without any creative effort:

[0013] Figure 1 It is a three-dimensional structural schematic diagram of the application;

[0014] Figure 2 It is a bottom view structural schematic diagram of the welding frame and the pressing plate of the application;

[0015] Figure 3 It is a structural schematic diagram of the wire, the rotating rod and the pressing column of the application;

[0016] Figure 4 It is a partial side view sectional structural schematic diagram of the connecting plate of the application;

[0017] Figure 5 It is a structural schematic diagram of the telescopic arm, the pressing plate and the sliding column of the application.

[0018] In the drawings: 1, welding frame; 2, telescopic arm; 3, pressing plate; 4, connecting plate; 5, wire; 6, contact rod; 7, mounting column; 8, mounting groove; 9, limiting plate; 10, tension spring; 11, movable groove; 12, connecting column; 13, rotating rod; 14, torsional spring; 15, fixed ring; 16, pressing column; 17, sliding column; 18, sliding rod; 19, stabilizing plate; 20, limiting groove. DETAILED DESCRIPTION

[0019] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those ordinarily skilled in the art without creative work fall within the scope of the present application.

[0020] Referring to Figures 1 to 5 A cylindrical lithium battery laser welding tool includes a welding frame 1, a telescopic arm 2 is slidingly installed outside the welding frame 1, a pressing plate 3 is fixedly installed at the bottom of the telescopic arm 2, the telescopic arm 2 is driven by a control system to move the pressing plate 3 downward during welding, the pressing plate 3 is first pressed on the surface of a battery connecting piece to limit the battery connecting piece, then a laser beam is emitted by a laser welding device to weld the welding point, a load resistor is movably installed at the bottom of the pressing plate 3, wires 5 are fixedly installed at both ends of the load resistor, a contact rod 6 is fixedly installed at the end of each wire 5 away from the load resistor, a connecting plate 4 is fixedly installed on one side of the pressing plate 3, the length of the connecting plate 4 is the same as the distance between the positive and negative electrodes on the same battery plate, the connecting plate 4 is used to electrically connect the positive and negative electrodes of the same battery plate and to provide support and protection for one of the wires 5, a mounting column 7 is fixedly installed on the inner side wall of a welding hole in the pressing plate 3, mounting grooves 8 are formed at the bottom of the connecting plate 4 and the mounting column 7, a limiting plate 9 is slidingly installed in the mounting groove 8, a tension spring 10 is fixedly installed at the bottom of the limiting plate 9, the limiting plate 9 and the tension spring 10 are sleeved on the outer side of the contact rod 6, the top end of the tension spring 10 is fixedly connected with the inner bottom wall of the mounting groove 8, under the action of the tension spring 10, the limiting plate 9 is pulled to the inner bottom wall of the mounting groove 8, and the bottom end of the contact rod 6 is also placed outside the mounting groove 8, when the battery connecting piece is welded, after the welding on one side is completed, the integrated system controls the welding frame 1, the telescopic arm 2 and the pressing plate 3 to move to the other side (for example, the positive electrode side of the battery plate), the telescopic arm 2 is driven by the control system to move the pressing plate 3 downward, the pressing plate 3 is first pressed on the surface of the battery connecting piece to limit the battery connecting piece, then a laser beam is emitted by a laser welding device to weld the welding point, and the above steps are repeated. Figure 1For example, when welding, the battery connecting piece on the surface of the end of the battery plate away from the pressing plate 3 is welded first, that is, the side welded first, at this time the connecting plate 4 is in a suspended state, so it will not affect the stability of the battery connecting piece, and after welding, it is moved to above the battery connecting piece close to the pressing plate 3, with the downward movement of the pressing plate 3, the contact rod 6 also contacts the battery connecting piece, when the bottom wall of the pressing plate 3 is attached to the battery connecting piece, the contact rod 6 is also extruded and slides to the inside of the mounting groove 8, the tension spring 10 is stretched, but under the action of the tension of the tension spring 10, during the gradual upward movement of the pressing plate 3 after the welding is completed, the contact rod 6 can still contact the surface of the battery connecting piece, thereby connecting the load resistance in series with the battery plate after welding, and the voltage division of the load resistance and the electromotive force of the battery plate are measured by the related instruments, combined with the known resistance value of the load resistance, the internal resistance value of the battery plate is deduced, if it is higher than the internal resistance value when welding without virtual welding, it indicates that the welding point on the battery plate may have a virtual welding situation, at this time, the CCD camera is used for shooting verification, if it is confirmed as virtual welding, relevant maintenance treatment is carried out, the internal resistance value of the battery plate is detected by connecting the load resistance in series to judge whether it is virtual welding, not only the detection requirement is completed, but also the CCD camera does not need to be continuously shot for a long time, reducing the hardware loss and overheating problem caused by continuous high-frequency shooting of the CCD camera, significantly prolonging the service life of the CCD camera.

[0021] The bottom of the pressing plate 3 is provided with a movable groove 11, the connecting column 12 is movably installed in the inside of the movable groove 11, the two connecting columns 12 are commonly fixedly installed with the rotating rod 13 away from one end of the telescopic arm 2, the torsional spring 14 is sleeved on the outside of the rotating rod 13, the two connecting columns 12 are fixedly installed with the fixed ring 15 close to one end of the telescopic arm 2, the two fixed rings 15 are commonly fixedly installed with the pressing column 16, and the load resistance is arranged in the inside of the pressing column 16, the wires 5 at both ends of the load resistance are respectively installed to the inside of the rotating rod 13 through the inside of the corresponding connecting column 12, and then are respectively installed to the inside of the mounting column 7 or the connecting plate 4 after penetrating through the rotating rod 13, thereby when the load resistance rotates with the pressing column 16, the related wires 5 will not be affected by the telescopic movement to affect the welding process, under the action of the torsional spring 14, when the pressing plate 3 moves downward, the inclined connecting column 12 makes the pressing column 16 first contact the surface of the battery connecting piece, with the continuous downward movement of the pressing plate 3, the connecting column 12 and the pressing column 16 rotate around the rotating rod 13, the pressing column 16 slides on the surface of the battery connecting piece, until the connecting column 12 and the pressing column 16 are pressed to the inside of the movable groove 11, through the pressing of the battery connecting piece by the pressing column 16, the probability of the gap between the battery connecting piece and the battery plate is further reduced, thereby the probability of the virtual welding of the welding point is reduced, and the welding quality is improved.

[0022] Two slide posts 17 are symmetrically and fixedly installed at the top of the end of the pressing plate 3 away from the telescopic arm 2, the bottom of the slide post 17 is slidably installed with a slide rod 18, the top end of the slide rod 18 and the inner top wall of the slide post 17 are jointly and fixedly installed with a spring, the bottom end of the slide rod 18 is movably penetrated through the pressing plate 3 and fixedly installed with a stabilizing plate 19, the top of the pressing plate 3 is provided with a limiting groove 20 matched with the stabilizing plate 19, when the pressing plate 3 is not lowered, the elastic force of the spring makes the stabilizing plate 19 below the pressing column 16, when the pressing plate 3 is lowered, the stabilizing plate 19 is first attached to the battery connecting piece to limit the battery connecting piece, preventing the battery connecting piece from deviating when the pressing column 16 slides on the surface of the battery connecting piece, with the continuous lowering of the pressing plate 3, the spring is compressed, the slide rod 18 gradually slides upwards, and finally the stabilizing plate 19 is pressed into the limiting groove 20 without affecting the normal pressing and limiting of the pressing plate 3.

[0023] Working principle:

[0024] When welding, the control system operates the telescopic arm 2 to drive the pressing plate 3 to lower, the pressing plate 3 is first pressed on the surface of the battery connecting piece to limit it, and then the laser welding device emits a laser beam to weld the welding point, when the pressing plate 3 is lowered, the stabilizing plate 19 is first attached to the battery connecting piece to limit the battery connecting piece, then the pressing column 16 is in contact with the surface of the battery connecting piece, with the continuous lowering of the pressing plate 3, the pressing column 16 slides on the surface of the battery connecting piece until the connecting column 12 and the pressing column 16 are pressed into the activity groove 11, by pressing the battery connecting piece by the pressing column 16, the probability of the gap between the battery connecting piece and the battery plate is further reduced;

[0025] When welding the first side, the connecting plate 4 is placed outside the battery plate in a suspended state to prevent it from touching the un-welded battery connecting piece and causing it to deviate. After the welding of one side is completed, the integrated system controls the welding frame 1, the telescopic arm 2, the pressing plate 3 and the like to move to the other side. With the downward movement of the pressing plate 3, the contact rod 6 also comes into contact with the battery connecting piece. When the bottom wall of the pressing plate 3 is attached to the battery connecting piece, the contact rod 6 is also pressed and slides to the inside of the mounting groove 8. The tension spring 10 is stretched. However, under the elastic force of the tension spring 10, the contact rod 6 can still be in contact with the surface of the battery connecting piece during the gradual upward movement of the pressing plate 3 after the welding is completed. In this way, the load resistor is connected in series with the battery plate after the welding is completed, and the voltage division of the load resistor and the electromotive force of the battery plate are measured by the related instruments. In combination with the known resistance value of the load resistor, the internal resistance value of the battery plate is derived. If it is higher than the internal resistance value when the welding is normal and there is no false welding, it indicates that the welding point on the battery plate may have false welding. At this time, the CCD camera is used to take a picture to verify it. If it is confirmed as false welding, relevant maintenance treatment is carried out. The internal resistance value of the battery plate is detected by connecting the load resistor in series to determine whether the welding point is false. Not only does it meet the detection requirements, but it can also more accurately determine whether the welding point has false welding. In addition, it does not require long-term continuous shooting of the CCD camera, avoids affecting the image quality of the CCD camera due to long-term continuous shooting, causes detection errors, prolongs the service life of the CCD camera, and improves the stability and reliability of the entire lithium battery assembly process.

[0026] The above description of disclosed embodiments enables one skilled in the art to make or use the application. Various modifications to these embodiments will be obvious to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cylindrical lithium battery laser welding tool, comprising a welding frame (1), a telescopic arm (2) is slidingly installed on the outer side of the welding frame (1), a pressing plate (3) is fixedly installed at the bottom of the telescopic arm (2), characterized in that, Also include the activity installation on the pressing plate (3) load resistance, both ends of the load resistance are fixedly installed with wire (5), both ends of the two wire (5) are fixedly installed with touch rod (6), the touch rod (6) is contacted with the battery connecting piece after the pressing plate (3) moves down, the load resistance and the completed battery plate form a series circuit, the series circuit is provided with the voltage for detecting the load resistance and the battery plate, the battery plate internal resistance feedback control system is used for judging whether the battery plate internal resistance is abnormal according to the known load resistance.

2. The laser welding tool for cylindrical lithium battery according to claim 1, wherein One side of the pressing plate (3) is fixedly installed with the connecting plate (4), and the length of the connecting plate (4) is the same as the distance between the positive and negative poles of the same battery plate, which is used for electrically connecting the positive and negative poles of the same battery plate.

3. The laser welding tool for cylindrical lithium battery according to claim 2, wherein, The inner side wall of the welding hole on the pressing plate (3) is fixedly installed with the mounting column (7), and the bottom of the connecting plate (4) and the mounting column (7) is provided with the mounting groove (8), the inside of the mounting groove (8) is slidably installed with the limiting plate (9), the bottom of the limiting plate (9) is fixedly installed with the tension spring (10), and the limiting plate (9) and the tension spring (10) are sleeved on the outside of the touch rod (6), the top end of the tension spring (10) is fixedly connected with the inner bottom wall of the mounting groove (8), which is used for ensuring the stable fit between the touch rod (6) and the battery connecting piece.

4. The laser welding tool for cylindrical lithium battery according to claim 3, wherein, The bottom of the pressing plate (3) is provided with the movable groove (11), the inside of the movable groove (11) is movably installed with the connecting column (12), the two connecting columns (12) are fixedly installed with the rotating rod (13) away from the telescopic arm (2), the outside of the rotating rod (13) is sleeved with the torsional spring (14), the two connecting columns (12) are fixedly installed with the fixed ring (15) close to the telescopic arm (2), the two fixed rings (15) are fixedly installed with the pressing column (16) between them, and the load resistance is arranged in the pressing column (16).

5. The laser welding tool for cylindrical lithium battery of claim 4, wherein, The top of the pressing plate (3) is symmetrically fixedly installed with two slide columns (17) away from the telescopic arm (2), the bottom of the slide column (17) is slidably installed with the slide rod (18), the top end of the slide rod (18) and the inner top wall of the slide column (17) are fixedly installed with the spring, the bottom end of the slide rod (18) is movably penetrated through the pressing plate (3) and fixedly installed with the stabilizing plate (19), and the top of the pressing plate (3) is provided with the limiting groove (20) matched with the stabilizing plate (19), which is used for providing the stabilizing plate (19) with a mounting space.

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