Automatic centering and assembling device for cylindrical battery pole group and working method of automatic centering and assembling device

Abstract

The invention relates to the technical field of lithium battery production equipment, in particular to an automatic centering assembly device for a cylindrical battery pole group and a working method of the automatic centering assembly device. The centering assembly device comprises a bearing structure, a magnetic suspension mechanism and a mechanical clamping mechanism. The bearing structure comprises a lapping plate, a mounting plate and a placing platform which are sequentially arranged in parallel; the magnetic suspension mechanism comprises a first electromagnet, a second electromagnet, a negative pole adsorption block and an iron core which are mounted between the lapping plate and the mounting plate, the first electromagnet and the second electromagnet realize non-contact suspension of the pole group, and the iron core and the negative pole adsorption block form rigid locking; the mechanical clamping mechanism comprises positioning blocks symmetrically arranged on the two sides of the containing platform, the positioning blocks are connected to the two-way driving mechanism, and opening and closing of the V-shaped positioning blocks are controlled through synchronous reverse movement of the two-way driving mechanism. By means of the centering mechanism, the problems that an existing mechanical clamping type centering mechanism is damaged in contact, insufficient in precision, low in efficiency, uneven in clamping force distribution and the like are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery production equipment, in particular to a cylindrical battery pole group automatic centering assembly device and a working method thereof. BACKGROUND

[0002] In the production process of cylindrical batteries, the centering assembly of the pole group is one of the key processes, which aims to ensure that the pole group is in the preset center position during assembly, providing a precise basis for subsequent welding, packaging and other processes, and directly affecting the performance, safety and service life of the battery.

[0003] At present, the centering assembly of the pole group of the cylindrical battery is mainly completed by a mechanical clamping mechanism, typically using a V-shaped block or a three-jaw chuck for positioning. Its core components include mechanical clamping components such as V-shaped blocks and three-jaw chucks, driving components such as servo motors and screw mechanisms, and some devices are also equipped with visual detection systems as an auxiliary. When working, the servo motor drives the screw mechanism to close the clamping jaw to clamp the pole group radially to achieve centering. The visual detection system is used in some advanced devices to assist positioning, but the core centering action is still completed by a pure mechanical structure, i.e. the pole group is adjusted to the center position by mechanical clamping.

[0004] The above existing technology has the following problems:

[0005] Firstly, the existing mechanical clamping mechanism adopts a rigid clamping method, which can easily cause wrinkles or scratches on ultra-thin pole pieces, especially copper foil or aluminum foil with a thickness of less than 50μm, affecting the quality of the pole group. Secondly, the pure mechanical structure is limited by transmission backlash and elastic deformation, and the centering accuracy is difficult to break through ±0.02mm, which is difficult to meet the assembly requirements of high energy density batteries such as 4680 specification batteries. In addition, visual detection and mechanical adjustment are performed in steps, resulting in a slow closed-loop response speed usually exceeding 200ms, which affects production efficiency. At the same time, the single V-shaped block clamping force is unevenly distributed, which is difficult to adapt to the ovality deviation of the pole group, further affecting the centering effect and the stability of the pole group. SUMMARY

[0006] In view of the deficiencies of the existing technology, the purpose of the embodiments of the present application is to provide a cylindrical battery pole group automatic centering assembly device. The present application aims to solve the problems of contact damage, insufficient accuracy, low efficiency and uneven clamping force distribution of the existing mechanical clamping type centering mechanism. By adopting a combination of magnetic suspension adjustment and mechanical clamping mechanism, the present application realizes non-contact precise positioning of the pole group and stability of the final assembly, improves the centering accuracy and assembly efficiency of the pole group, reduces the damage rate of ultra-thin pole pieces, and at the same time adapts to the assembly requirements of pole groups of different specifications, especially large size pole groups, providing protection for efficient and high quality production of cylindrical batteries.

[0007] To achieve the above object, the embodiment of the present application provides the technical scheme as follows.

[0008] The cylindrical battery pole group automatic centering assembly device comprises a bearing structure, a magnetic suspension mechanism and a mechanical clamping mechanism.

[0009] Optionally, the first electromagnet and the second electromagnet are both provided with a plurality of annular arrays, the first electromagnet is fixed to the top surface of the lap joint plate, and the second electromagnet is fixed to the bottom surface of the mounting plate.

[0010] Optionally, the positioning block is connected to the bidirectional driving mechanism, and the opening and closing of the V-shaped positioning block are controlled through synchronous reverse movement of the bidirectional driving mechanism.

[0011] Optionally, the bearing structure further comprises a mounting platform and a first electric telescopic rod, the mounting platform is located at the bottom of the lap joint plate, and the first electric telescopic rod is arranged between the mounting platform and the lap joint plate.

[0012] Optionally, the visual detection system comprises support rods supported around the mounting platform, second electric telescopic rods mounted at the top ends of the support rods, rotating mechanisms arranged at the output ends of the second electric telescopic rods, and cameras carried on the rotating mechanisms.

[0013] The embodiment of the present application further provides a working method of the cylindrical battery pole group automatic centering assembly device as described above, comprising:

[0014] The magnetic suspension mechanism is controlled to be powered on, so that the pole group is suspended in contactless manner above the placement platform;

[0015] Obtaining the position and angle deviation of the pole group through visual scanning;

[0016] Adjusting the electromagnetic field distribution of the magnetic suspension mechanism according to the deviation parameters, and performing radial position compensation and tangential angle compensation on the pole group;

[0017] When the pose of the pole group reaches a set threshold, the positioning blocks of the mechanical clamping mechanism are synchronously closed to contactively clamp the pole group.

[0018] Optionally, the adjusting magnetic suspension mechanism comprises: generating a lateral fine-tuning force in the radial direction by independently controlling the current difference of the annular array electromagnetic units; and generating a rotation torque to correct the circumferential angle deviation of the pole group through the tangential electromagnetic field.

[0019] Optionally, the visual scanning comprises: controlling the camera to descend to a preset height along the Z axis; driving the camera to rotate around the pole group to perform spiral trajectory scanning; and outputting the six-degree-of-freedom pose deviation parameters of the pole group based on laser triangulation and image processing algorithms.

[0020] Optionally, the control of the closure of the V-shaped positioning blocks comprises: dynamically adjusting the closure displacement according to a preset clamping force model; and correcting the clamping force in real time through the feedback data of the clamping force sensor to ensure that the roundness error does not exceed a set threshold.

[0021] Optionally, the pose deviation parameters, the electromagnetic field adjustment, and the mechanical clamping action form a closed-loop control, and the closed-loop response time is less than a set threshold.

[0022] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0023] 1. In the centering assembly device, the lap plates, mounting plates and placement platforms of the bearing structure are arranged in parallel, providing a stable spatial layout basis for the magnetic suspension mechanism and the mechanical clamping mechanism. The first electromagnet and the second electromagnet of the magnetic suspension mechanism realize the non-contact suspension of the pole group through the electromagnetic field effect, avoiding the contact damage of the ultra-thin pole piece caused by directly using the traditional mechanical rigid clamping, and solving the problem of contact damage risk. The rigid locking formed by the iron core and the negative adsorption block can fix the structure in the non-working state, prevent loosening and reduce energy consumption. The symmetrical positioning blocks of the mechanical clamping mechanism cooperate with the bidirectional driving mechanism to realize symmetrical clamping through synchronous reverse motion, reducing the uneven stress of unilateral clamping. Combined with the non-contact positioning of the magnetic suspension mechanism, the centering accuracy breaks through the limitation of ±0.02mm of the traditional mechanical structure, and the adjustment time is shortened, solving the problem of low efficiency. The three work together to realize non-contact precise positioning and ensure assembly stability through mechanical clamping, which is especially suitable for the assembly of ultra-thin pole pieces and high-energy-density batteries.

[0024] 2. By combining magnetic suspension adjustment with mechanical clamping mechanism, both non-contact precise positioning of pole group and stability of final assembly are realized, by electromagnetic-mechanical cooperative control mode, the centering accuracy of pole group is improved, which is especially suitable for assembly requirements of various cylindrical batteries. By adopting segmented clamping design, the shape characteristics of pole groups of different specifications can be automatically adapted, and uniform distribution of clamping force is ensured. The integrated visual detection system and magnetic suspension mechanism form a quick response closed loop, improving assembly efficiency, and special materials and surface treatment processes are used for key components, effectively prolonging the service life of the equipment. The whole system has intelligent identification and automatic adjustment functions, and can realize overall quality control of the production process, while ensuring assembly accuracy, improving product yield and production efficiency, and providing reliable protection for the production of cylindrical batteries.

[0025] 3. In the suspension stage, the electromagnetic system completes the coarse positioning of the pole group, and the visual system scans the position of the tab in real time, then the mechanical clamping starts pre-clamping at the end of the suspension adjustment, the two time overlaps, the contact stress is eliminated in the suspension stage, and only fine adjustment of clamping force is needed in the mechanical stage, avoiding the risk of wrinkles caused by rigid contact in the whole process of traditional scheme.

[0026] 4. Compared with uneven distribution of clamping force of single V-shaped block, it is difficult to adapt to the ovality deviation, the present application solves the problem of uneven distribution of clamping force by three-point support of double V-shaped block and elastic placement pad.

[0027] 5. The current difference of the annular array electromagnetic unit can generate different lateral forces in the radial direction, realize fine adjustment of the X / Y direction of the pole group, and the adjustment resolution can reach 0.5 mu m, which can accurately compensate for small position deviation. The tangential electromagnetic field can generate a rotating torque to correct the circumferential angle deviation of the pole group, ensure the accuracy of the tab position, and provide convenience for subsequent welding and other processes. Through the PID control algorithm, the height deviation can be quickly responded, the static error can be eliminated and the oscillation can be suppressed, so that the pole group can remain stable in the suspended state, avoiding the adjustment lag and overshoot problems caused by rigid contact in the traditional mechanical adjustment, and further improving the centering accuracy and stability.

[0028] The advantages of the additional aspects of the present application will be given in the following description, some of which will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings. In addition, the sizes or distances between each other are exaggerated for showing the positions of the components, and the schematic diagram is only used for illustration.

[0030] Figure 1 is the overall schematic diagram of the device provided by the embodiment of the application;

[0031] Figure 2 is the lower side schematic diagram of the lap joint plate provided by the embodiment of the application;

[0032] Figure 3 is the arrangement schematic diagram between the lap joint plate and the mounting plate provided by the embodiment of the application;

[0033] Figure 4 is the schematic diagram of the magnetic suspension mechanism provided by the embodiment of the application;

[0034] Figure 5 is the schematic diagram of the mechanical clamping mechanism provided by the embodiment of the application;

[0035] In the figure: 1, mounting platform; 2, first electric telescopic rod; 3, lap joint plate; 4, first electromagnet; 5, negative adsorption block; 6, iron core; 7, mounting plate; 8, second electromagnet; 9, assembly box; 10, servo motor; 11, driving rod; 12, reversible screw rod; 13, threaded sleeve ring; 14, V-shaped positioning block; 15, placement platform; 16, sliding frame; 17, placement pad; 18, support rod; 19, second electric telescopic rod; 20, fixed clamping block; 21, camera; 22, controller. DETAILED DESCRIPTION

[0036] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs. Furthermore, it should be understood that the use of the terms "include", "includes" and / or "comprise", "comprises" and / or "comprising" in this specification indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Example 1

[0038] As shown in Figure 1 , Figure 2 , the embodiment proposes a cylindrical battery pole group automatic centering assembly device, which comprises a bearing structure, a magnetic suspension mechanism and a mechanical clamping mechanism; as shown in Figure 3 , the bearing structure comprises a lap joint plate 3, a mounting plate 7 and a placement platform 15 arranged in parallel in sequence; as shown in Figure 4 , the magnetic suspension mechanism comprises a first electromagnet 4, a second electromagnet 8, a negative adsorption block 5 and an iron core 6 mounted between the lap joint plate 3 and the mounting plate 7, the first electromagnet 4 and the second electromagnet 8 realize non-contact suspension of the pole group, and the iron core 6 and the negative adsorption block 5 form a rigid lock; as shown in Figure 5As shown, the mechanical clamping mechanism includes positioning blocks symmetrically arranged on both sides of the placement platform 15, which are connected to a bidirectional driving mechanism. The opening and closing of the V-shaped positioning block 14 are controlled by the synchronous reverse movement of the bidirectional driving mechanism.

[0039] The bearing structure provides a stable foundation support for the entire device. The lap plate 3, mounting plate 7, and placement platform 15 are arranged in parallel in sequence, forming a stable space frame that ensures the stability of the pole group during assembly. The magnetic suspension mechanism uses electromagnetic principles to achieve non-contact suspension of the pole group. The interaction between the first electromagnet 4 and the second electromagnet 8 generates a suspension force, allowing the pole group to be stably suspended above the placement platform 15, avoiding the risk of contact damage to the pole pieces caused by traditional mechanical clamping methods. At the same time, the cooperation of the negative electrode adsorption block 5 and the iron core 6 forms a rigid lock in the power-off state, improving the structural stability of the device in the non-working state. The mechanical clamping mechanism controls the opening and closing of the V-shaped positioning block 14 through the bidirectional driving mechanism, achieving precise clamping of the pole group. Through the cooperation of the bearing structure, magnetic suspension mechanism, and mechanical clamping mechanism, the problems of pole piece damage, insufficient centering accuracy, and low production efficiency in the traditional mechanical clamping mechanism during centering assembly are solved.

[0040] The first electromagnet 4 and the second electromagnet 8 are arranged in a ring array, the first electromagnet 4 is fixed to the top surface of the lap plate 3, and the second electromagnet 8 is fixed to the bottom surface of the mounting plate 7; the negative electrode adsorption block 5 is fixed to the four corners of the top surface of the lap plate 3, and the iron core 6 is fixed to the four corners of the bottom surface of the mounting plate 7.

[0041] As shown in Figure 4 The first electromagnet 4 and the second electromagnet 8 are arranged in a ring array, making the electromagnetic field more uniformly distributed around the pole group, and the resultant force can more accurately balance the gravity of the pole group, improving the stability of the suspension and reducing the shaking during the suspension process; the first electromagnet 4 and the second electromagnet 8 are fixed to the top surface of the lap plate 3 and the bottom surface of the mounting plate 7, respectively, and the positions correspond, ensuring the effective action of the magnetic field force and enhancing the accuracy of the suspension control. The negative electrode adsorption block 5 and the iron core 6 are fixed to the four corners, and in the non-working state, the adsorption force of the iron core 6 and the negative electrode adsorption block 5 can be evenly distributed at the four corners of the structure, ensuring the stability of the rigid lock and avoiding structural deformation caused by excessive local stress.

[0042] The positioning block is connected to a bidirectional driving mechanism, and the opening and closing of the V-shaped positioning block 14 are controlled through synchronous reverse movement of the bidirectional driving mechanism; the bidirectional driving mechanism comprises a servo motor 10, a positive and negative rotation screw rod 12 and a threaded sleeve ring 13; the servo motor 10 is connected to the positive and negative rotation screw rod 12 through a driving rod 11, and the rotation directions of the two ends of the positive and negative rotation screw rod 12 are opposite; the threaded sleeve ring 13 is threadedly installed at the two ends of the positive and negative rotation screw rod 12, and the top end is fixedly connected to the V-shaped positioning block 14; the bottom of the V-shaped positioning block 14 is matched with a sliding frame 16 fixed to a placement platform 15 through a sliding block.

[0043] The servo motor 10 is directly connected to the positive and negative rotation screw rod 12 through the driving rod 11, which improves the accuracy of power transmission; the rotation directions of the two ends of the positive and negative rotation screw rod 12 are opposite, so that the threaded sleeve ring 13 can drive the V-shaped positioning block 14 to move synchronously and reversely, thereby ensuring the symmetry of the clamping action on both sides and avoiding the deviation caused by unilateral movement lag. The threaded sleeve ring 13 is fixedly connected to the V-shaped positioning block 14, and the sliding block at the bottom of the V-shaped positioning block 14 is matched with the sliding frame 16, which limits the movement trajectory of the V-shaped positioning block 14, so that it only slides in a linear direction, reduces the lateral deviation error, and improves the accuracy of clamping and positioning.

[0044] The bearing structure further comprises a mounting platform 1 and a first electric telescopic rod 2, the mounting platform 1 is located at the bottom of the lap plate 3, and the first electric telescopic rod 2 is arranged between the mounting platform 1 and the lap plate 3.

[0045] The mounting platform 1 is located at the bottom of the lap plate 3 and serves as a basic bearing component of the entire device, providing a stable reference surface for the components above, such as the lap plate 3 and the mounting plate 7. The first electric telescopic rod 2 is arranged between the mounting platform 1 and the lap plate 3, and the first electric telescopic rod 2 adjusts the height of the lap plate 3, providing a stable initial condition for the subsequent PID control of the magnetic suspension mechanism.

[0046] The automatic centering assembly device further comprises a visual detection system and a controller 22, the visual detection system comprises a support rod 18 supported around the mounting platform 1, a second electric telescopic rod 19 mounted at the top end of the support rod 18, a rotating mechanism arranged at the output end of the second electric telescopic rod 19, and a camera 21 carried on the rotating mechanism, the camera 21 is used for scanning the position of the pole group, and the controller 22 is electrically connected with the magnetic suspension mechanism, the mechanical clamping mechanism and the camera 21 respectively, and is used for coordinating the suspension positioning and the mechanical clamping action.

[0047] The support rod 18 is supported around the mounting platform 1, which ensures the stable installation of the visual detection component and ensures the trajectory accuracy of the camera 21 during scanning. The second electric telescopic rod 19 can drive the camera 21 to ascend and descend along the Z axis, and the rotating mechanism drives the camera 21 to rotate around the pole group, and the two cooperate to realize spiral trajectory scanning, which can comprehensively obtain the pose information of the pole group, avoid scanning dead angles, and improve the integrity of the deviation detection. The deviation data obtained by the camera 21 is transmitted to the controller 22 in real time, and the controller 22 coordinates the actions of the magnetic suspension mechanism and the mechanical clamping mechanism, so that the electromagnetic adjustment of the magnetic suspension and the position adjustment of the mechanical clamping are linked to realize closed-loop control, shorten the closed-loop response time, solve the low efficiency problem caused by the step-by-step traditional visual detection and mechanical adjustment, and improve the centering accuracy.

[0048] Specifically, the top of the mounting platform 1 is fixedly connected with a plurality of first electric telescopic rods 2, and the middle of the top of the mounting platform 1 is fixedly connected with a controller 22; the output end of the first electric telescopic rod 2 is fixedly connected with a lap plate 3, the top of the lap plate 3 is fixedly connected with a plurality of first electromagnets 4 arranged in a ring shape and a plurality of negative adsorption blocks 5, the first electromagnet 4 adopts a 12-group neodymium-iron-boron permanent magnet and electromagnetic coil composite structure, the top of the negative adsorption block 5 is lapped with an iron core 6, the inner wall of the iron core 6 is electrically connected with an electric connector, the top of the iron core 6 is fixedly installed at the bottom of a mounting plate 7, the bottom of the mounting plate 7 is also fixedly connected with a plurality of second electromagnets 8 arranged in a ring shape, and the positions of the first electromagnet 4 and the second electromagnet 8 correspond to each other.

[0049] Through the setting of the mounting platform 1, the first electric telescopic rod 2, the controller 22, the lap plate 3, the first electromagnet 4, the negative adsorption block 5, the iron core 6, the mounting plate 7 and the second electromagnet 8, when in use, the mounting platform 1 serves as the bearing basis of the whole system, the levelness thereof is precisely calibrated, the precision is ≤0.02mm / m, and a reference surface is provided for subsequent precise centering; the first electric telescopic rod 2 is symmetrically arranged at the four corners of the platform, synchronous lifting is realized through the instruction of the controller 22, the stroke is 100mm, the repeat positioning accuracy is ±0.01mm, and the lap plate 3 connected with the output end of the first electric telescopic rod 2 constitutes the lower support surface of the magnetic suspension mechanism; the first electromagnet 4 arranged in a ring shape on the lap plate 3 and the second electromagnet 8 at the bottom of the mounting plate 7 jointly form a closed-loop magnetic field system.

[0050] The negative adsorption block 5 adopts a silicon steel sheet lamination structure, the iron core 6 adopts a permalloy material, the negative adsorption block 5 and the iron core 6 constitute a magnetic circuit conduction component, contactless suspension is realized in the working state, the rigid locking anti-looseness structure is prevented in the non-working state through the iron core 6-negative adsorption block 5, pure repulsive force suspension needs continuous energy consumption, and the anti-vibration ability is poor, the suction force locking can maintain stability when powered off in standby mode, and the energy consumption is reduced.

[0051] When the electric appliance supplies electricity to the iron core 6, the iron core 6 forms a positive magnetic suction block, generates an adsorption force of ≥50N with the negative adsorption block 5, rigidly fixes the lap plate 3 and the mounting plate 7 in a non-working state, and avoids structural looseness during transportation or standby.

[0052] The top of the mounting plate 7 is fixedly connected with an assembly box 9, the inner wall of the assembly box 9 is fixedly connected with a servo motor 10, the output end of the servo motor 10 is provided with a driving rod 11, the front end of the driving rod 11 is fixedly connected with a positive and negative rotation screw rod 12, the rotation directions of the threads at both ends of the positive and negative rotation screw rod 12 are opposite, and the surface of the positive and negative rotation screw rod 12 is threadedly provided with a threaded sleeve ring 13 at both ends, and the top end of the threaded sleeve ring 13 is fixedly connected with a V-shaped positioning block 14.

[0053] The top of the assembly box 9 is fixedly connected with a placement platform 15, and the top of the placement platform 15 is arranged at the bottom of the V-shaped positioning block 14, both sides of the bottom of the V-shaped positioning block 14 are fixedly connected with sliding blocks, the sliding blocks are slidingly installed in a sliding frame 16, and the sliding frame 16 is fixedly connected to the inner wall of the assembly box 9. The top of the placement platform 15 is fixedly connected with a placement pad 17.

[0054] Through the arrangement of the mounting plate 7, the assembly box 9, the servo motor 10, the driving rod 11, the positive and negative rotation screw rod 12, the threaded sleeve ring 13, the V-shaped positioning block 14, the placement platform 15, the sliding frame 16 and the placement pad 17, when in use, the mounting plate 7 serves as a bearing base of a mechanical clamping mechanism, the bottom of the mounting plate 7 is rigidly connected with the iron core 6 of the magnetic suspension mechanism, and the overall structural stability is ensured; the assembly box 9 is fixed to the top of the mounting plate 7 and serves as a sealed protective shell of a driving system, and the servo motor 10 arranged inside is directly connected with the positive and negative rotation screw rod 12 through the driving rod 11.

[0055] The servo motor 10 can adopt Yaskawa Sigma-7 series, 200W, is provided with a 17-bit absolute value encoder, the positive and negative rotation screw rod 12 is designed in double-thread, the lead is 4mm and the pitch is 2mm. The threaded sleeve ring 13 is made of bronze graphite composite material, the friction coefficient is <0.08. The opening angle of the V-shaped positioning block 14 is 110°±5°, the surface is plated with hard chromium, the gap of the sliding frame 16 is 0.005mm, is coated with a molybdenum disulfide lubricating layer, and the placement pad 17 is made of polyurethane material, the Shore hardness is 70A, and the friction coefficient μ is ≥0.6.

[0056] The four corners of the surface of the mounting platform 1 are fixedly connected with support rods 18, the top end of the support rod 18 is inserted with a second electric telescopic rod 19, the output end of the second electric telescopic rod 19 is fixedly connected with a fixed clamping block 20, the inner wall of the fixed clamping block 20 is rotatably installed with a camera 21, one side of the fixed clamping block 20 is fixedly connected with a driving mechanism, and the output end of the driving mechanism is fixedly connected to one side of the camera 21. The stroke of the second electric telescopic rod 19 is 150 mm, and the repeat positioning accuracy is ±0.005 mm.

[0057] Through the setting of the support rod 18, the second electric telescopic rod 19, the fixed clamping block 20 and the camera 21, when in use, the support rod 18 serves as the support structure of the visual detection system, and is vertically fixed at the four corners of the mounting platform 1. The parallelism error of each column is ensured to be ≤0.01 mm through milling processing, so as to provide a stable motion reference for the camera 21; the second electric telescopic rod 19 is inserted into the top end of the support rod 18 through a flange connector, the fixed clamping block 20 installed at the output end of the second electric telescopic rod 19 adopts a split design, the built-in worm and gear mechanism drives the camera 21 to realize accurate deflection of ±30°, the transmission ratio of the worm and gear mechanism is 30:1, and the deflection angle resolution is 0.1°. The high-precision camera 21 is equipped with a telecentric lens and a ring-shaped LED fill light, and through the linkage of the Z-direction lifting of the second electric telescopic rod 19 and the rotation of the fixed clamping block 20, the polar group can be scanned in full circumferential direction without dead angle. The high-precision camera 21 adopts the CV-X200 series of Keyence, with 5 million pixels, a telecentric lens with a distortion rate of <0.1%, a ring-shaped LED fill light with a color temperature of 6000K, and a minimum focusing distance of scanning of 50 mm.

[0058] Embodiment 2

[0059] The embodiment provides a working method of the cylindrical battery polar group automatic centering assembly device as described in Embodiment 1, which comprises the following steps:

[0060] Initialization preparation: the controller cuts off the core suction force, releases the structural locking, and lifts the lap plate to the working height by the first electric telescopic rod.

[0061] Polar group feeding: the mechanical arm places the polar group on the placement pad, and the V-shaped positioning block is in the open state.

[0062] Suspension coarse adjustment: the first electromagnet and the second electromagnet are electrified to generate a balanced repulsive force to make the polar group suspended, the visual system rapidly scans globally, and the initial deviation of the polar group is detected.

[0063] Visual fine measurement and electromagnetic fine adjustment: the camera spirally scans around the polar group, and the ICP algorithm outputs the freedom deviation parameters.

[0064] Controller adjusts the current of the electromagnetic coil: corrects the position deviation by the radial current difference, generates a torque to rotate the polar group by the tangential coil, and compensates the tab angle.

[0065] Mechanical fine locking: After suspension positioning, the servo motor drives the forward and reverse screw, and the double V-shaped block synchronously closes to the light contact state. The clamping force sensor feedbacks the data, dynamically adjusts the closing distance to ensure the roundness.

[0066] Assembly handover: The controller confirms the centering completion, the second electric telescopic rod lowers the camera to avoid, the overall mechanism is transferred to the next station, and the electromagnetic system is powered off. The suction system enables the locking structure.

[0067] Controlling the magnetic suspension mechanism to be powered on makes the pole group contactless suspension, avoiding contact damage in the initial stage of mechanical clamping from the source, especially protecting ultra-thin pole pieces with a thickness of less than 50 μm. Through visual scanning, the deviation is obtained to provide accurate basis for subsequent adjustment, avoiding the waste of efficiency caused by blind adjustment. According to the deviation, the electromagnetic field distribution is adjusted to realize radial and tangential compensation, which can correct the position and angle deviation of the pole group, ensuring that the pole group can achieve high centering accuracy in the suspended state. When the pole group pose meets the standard, mechanical clamping is performed, at which time mechanical clamping only serves as locking rather than correction, reducing the intervention of mechanical force on the pole group and reducing the risk of contact damage. Magnetic suspension and mechanical clamping work together to improve the centering accuracy, reduce the damage rate, shorten the overall centering time, and solve the multiple problems of damage, accuracy and efficiency in traditional methods.

[0068] Adjusting the magnetic suspension mechanism includes generating a lateral fine adjustment force in the radial direction by independently controlling the current difference of the annular array electromagnetic unit, and generating a rotating torque to correct the circumferential angle deviation of the pole group by the tangential electromagnetic field.

[0069] When the system is powered on, the first electromagnet generates an upward attractive force with a maximum magnetic field strength of 0.4 T, and the second electromagnet generates a cooperative repulsive force. The resultant force of the two is accurately balanced by the pole group gravity through the PID control algorithm, with a typical value of 0.49 N ± 0.05 N, realizing the contactless suspension of the pole group. Specifically: set the target suspension height ht = 1.0 mm, detect the real-time height hc, calculate the height error e = ht - hc, and PID calculates the current adjustment amount: P = Kp * e, which quickly responds to the height deviation; I = Ki * ∫edt, which eliminates static errors such as pole group weight fluctuations; D = Kd * de / dt, which suppresses oscillation such as external vibration. The output current Iout = I0 + (P + I + D), where I0 is the initial balance current, Kp = 2.5: the current increases by 250 mA for every 0.1 mm increase in height deviation, Ki = 0.8: the current increases by 800 mA for every 1 mm·s of cumulative height error, and Kd = 1.2: the current increases by 120 mA for every 0.1 mm / s of height change rate.

[0070] When the device is in transport or standby state, the iron core 6 is powered to become a "positive magnetic suction block", which generates a strong adsorption force of ≥50N with the negative adsorption block 5, rigidly fixing the lap plate 3 and the mounting plate 7; when working, the iron core 6 is powered off to release the adsorption force, so that the lap plate 3 and the mounting plate 7 are disconnected rigidly, thereby avoiding interference with the magnetic suspension fine adjustment. If the lap plate 3 and the mounting plate 7 are rigidly locked, the fine adjustment force of the electromagnetic coil cannot be transmitted to the pole group, and the suspension adjustment function fails.

[0071] When working, the power is turned off to release the fixation, at which time the first electromagnet and the second electromagnet enter the precise regulation mode, and by independently adjusting the current difference of the 4-quadrant electromagnetic coil, for example, increasing the left coil current by 10% while decreasing the right side by 10%, a lateral fine adjustment force of 0.1-0.3N can be generated in the radial direction, realizing an adjustment range of ±0.5mm in the X / Y direction of the pole group, with a resolution of 0.5μm. Further, an additional winding arranged in the tangential direction of the electromagnet generates a rotating torque after being powered, compensating for the circumferential angular deviation of the top lug of the pole group, ensuring the alignment of the subsequent welding station. The auxiliary coil arranged in the tangential direction generates a rotating torque based on the torque formula τ=nIBLr, which compensates for the angular deviation of the lug, where n: number of turns, I: tangential coil current, B: magnetic induction intensity of the radial main magnetic field, L: effective length, r: pole group radius, deviation ±0.01°.

[0072] This magnetic suspension mechanism and the subsequent mechanical clamping mechanism form a two-stage centering system of "first suspension coarse adjustment - then mechanical fine locking". Before mechanical clamping, the magnetic suspension has positioned the pole group within an error range of ±0.005mm, and the V-shaped block only applies a maintenance force, and the final accuracy is guaranteed by the suspension system, and the mechanical module only "locks" but does not "correct". Compared with the traditional pure mechanical clamping scheme, not only is the contact stress caused by the pole piece wrinkle eliminated, and the damage rate is reduced from 0.8% to 0.02%, but also the comprehensive centering accuracy is improved to ±0.005mm through electromagnetic-mechanical cooperative control, which is especially suitable for ultra-thin pole piece assembly scenarios with a thickness of <50μm.

[0073] The visual scanning includes: controlling the camera to descend to a preset height along the Z axis; driving the camera to rotate around the pole group to perform spiral trajectory scanning; based on laser triangulation and image processing algorithm, outputting six-degree-of-freedom pose deviation parameters of the pole group.

[0074] The camera is controlled to descend along the Z-axis to a preset height, which can ensure clear focusing during scanning and reduce deviation detection errors caused by image blur. The camera is driven to rotate around the pole group to perform spiral trajectory scanning, which can cover the full circumferential surface of the pole group and avoid information omission caused by local scanning, and can accurately capture the position information of the pole lug. Based on the laser triangulation and image processing algorithm, three-dimensional point cloud data of the pole group can be obtained, and the six-degree-of-freedom pose deviation is calculated by the improved ICP algorithm, so that the deviation detection accuracy reaches X / Y / Z three-axis ±0.003mm and rotation around Z-axis ±0.01°, which provides high-precision parameters for magnetic suspension adjustment and mechanical clamping, solves the problem of insufficient accuracy of traditional visual detection, and ensures the accuracy of subsequent adjustment.

[0075] During work, the controller first controls the second electric telescopic rod to descend to a preset height, for example, 20mm from the upper surface of the pole group, and then starts the camera for the first global positioning, which takes 0.3s. The image processing algorithm is used to identify the edge of the pole group and the position of the pole lug. Here, existing technologies are used, such as image acquisition, preprocessing, edge detection based on OpenCV, template matching, and output of position deviation. When the detected deviation exceeds the threshold value, which is ±0.05mm by default, the system drives the camera to rotate and scan around the pole group at a speed of 10° / s, and the fixed clamping block is embedded with a worm gear set with a transmission ratio of 30:1 to drive the camera to deflect. The second electric telescopic rod drives the camera to ascend and descend, and combined with rotation, it realizes a spiral scanning trajectory to cover the full surface of the pole group. In addition, the camera bottom is integrated with a laser triangulation module, which obtains three-dimensional point cloud data. Combined with the improved ICP algorithm, the transformation matrix of the actual pose of the pole group and the theoretical pose is calculated. The steps of the improved ICP algorithm include:

[0076] Initial pose estimation: generate an initial transformation matrix based on the visual template matching result;

[0077] Point cloud preprocessing: reduce sampling through voxel filtering and remove background point cloud based on height threshold;

[0078] Feature weighting: assign a weight coefficient ω=2.0 to the point cloud in the pole lug area and ω=0.8 to the non-pole lug area;

[0079] Iterative optimization: use KD tree to accelerate corresponding point search, solve the optimal transformation with a weighted least squares objective function, and then update it using the Levenberg-Marquardt algorithm;

[0080] Convergence criterion: terminate when the displacement change Δerror of the transformation matrix is less than 0.001mm or the iteration count is greater than 50 times.

[0081] The final output includes six-degree-of-freedom correction parameters of X / Y / Z three-axis displacement deviation and rotation deviation around the Z axis, the X / Y / Z three-axis displacement deviation is ±0.003 mm, and the rotation deviation around the Z axis is ±0.01°, these data are fed back to the controller in real time through industrial Ethernet (EtherCAT protocol) for dynamically adjusting the working parameters of the magnetic suspension mechanism and the mechanical clamping mechanism, including the magnetic suspension quadrant coil current, the control of the radial / tangential force, and the target position of the mechanical clamping V-shaped block and the clamping force.

[0082] The cooperation of the visual detection system and the mechanical structure shortens the response time of the closed-loop control of the pole group centering process to 80 ms, improves the precision by 5 times compared with the traditional photoelectric sensor scheme, and can ensure that stable images with a signal-to-noise ratio of >40 dB are obtained on pole groups with different surface characteristics, such as copper foil / aluminum foil, through an adaptive illumination adjustment algorithm I=K∫(ΔE)dt, wherein I is the illumination intensity, K is the illumination intensity adjustment coefficient, and ΔE is the image gray variance, thereby finally realizing a 99.98% accuracy of the pole lug position recognition.

[0083] The control of the V-shaped positioning block closing includes dynamically adjusting the closing displacement according to a preset clamping force model, and correcting the clamping force in real time through feedback data of the clamping force sensor to ensure that the roundness error does not exceed the set threshold.

[0084] The dynamic adjustment of the closing displacement according to the preset clamping force model can automatically match the appropriate clamping force for different specifications of the pole group, especially for ultra-thin pole pieces, to avoid deformation of the pole piece caused by excessive clamping force or loosening of the pole group caused by insufficient clamping force. The real-time correction of the clamping force through the feedback data of the clamping force sensor can dynamically compensate for the possible roundness deviation of the pole group to ensure that the roundness error of the pole group is within the set range.

[0085] When the controller issues an instruction, the servo motor drives the forward and reverse screw rod to rotate, driving the two threaded sleeves to move synchronously and reversely, and the movement precision can reach ±0.005 mm; the V-shaped positioning block connected to the top of the threaded sleeve moves linearly on the placement platform through the cooperation of the bottom sliding block and the sliding frame; the placement platform serves as the direct bearing surface of the pole group, and the placement pad arranged on the surface provides buffer protection and prevents the pole group from sliding through the high friction coefficient; when the system is working, the servo motor drives the forward and reverse screw rod to rotate, causing the two V-shaped positioning blocks to move towards each other along the sliding frame track, thereby implementing three-point contact clamping of the pole group from the diameter direction, wherein the two V-shaped blocks and the placement pad constitute the third supporting point, and the clamping force is automatically adjusted through a preset clamping force control algorithm, and the target clamping force F=KΔx, wherein K is the stiffness coefficient 5 N / mm, and Δx is the deviation value of the actual displacement of the V-shaped positioning block from the target position.

[0086] Both ensure that the roundness error of the pole group is less than or equal to 0.01 mm, and avoid deformation of the pole piece caused by overpressure; the mechanical clamping mechanism cooperates with the aforementioned magnetic suspension mechanism to complete coarse positioning within a range of ±0.5 mm, and the V-shaped positioning block implements final precise clamping, and the cooperation of the two shortens the overall centering time to within 0.5 seconds, and improves the repeat positioning accuracy of the center position of the pole group to ±0.003 mm, especially when dealing with large-size battery pole groups such as 21700, for example, a diameter of 21 mm and a height of 70 mm, the uniformity deviation of the clamping force can still be kept less than 2%, which is better than the ±5% fluctuation level of the traditional single V-shaped block structure.

[0087] The pose deviation parameter forms a closed-loop control with the electromagnetic field adjustment and the mechanical clamping action, and the closed-loop response time is less than a set threshold. The pose deviation parameter forms a closed-loop control with the electromagnetic field adjustment and the mechanical clamping action, so that the actions of each link can be dynamically adjusted according to the real-time deviation, avoiding the decline in centering accuracy caused by accumulated errors in open-loop control. The closed-loop response time is less than a set threshold, which is obviously improved compared with the response speed of traditional step-by-step control, shortens the centering time of a single pole group, and improves the production efficiency.

[0088] Although the specific embodiments of the present application are described above in combination with the drawings, it is not a limitation on the protection scope of the present application, and those skilled in the art should understand that various modifications or deformations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. An automatic alignment and assembly device for cylindrical battery electrode packs, characterized in that: This includes the load-bearing structure, the magnetic levitation mechanism, and the mechanical clamping mechanism; The load-bearing structure includes an overlapping plate, a mounting plate, and a placement platform arranged in parallel in sequence. The magnetic levitation mechanism includes a first electromagnet, a second electromagnet, a negative electrode adsorption block, and an iron core installed between the overlapping plate and the mounting plate. The first electromagnet and the second electromagnet achieve contactless levitation of the pole group, and the iron core and the negative electrode adsorption block form a rigid lock. The mechanical clamping mechanism includes positioning blocks symmetrically arranged on both sides of the placement platform. The positioning blocks are connected to a bidirectional drive mechanism, and the opening and closing of the V-shaped positioning blocks are controlled by the synchronous reverse movement of the bidirectional drive mechanism.

2. The automatic alignment and assembly device for cylindrical battery electrode packs as described in claim 1, characterized in that: The first electromagnet and the second electromagnet each have multiple electromagnets arranged in a ring array. The first electromagnet is fixed to the top surface of the overlapping plate, and the second electromagnet is fixed to the bottom surface of the mounting plate. The negative electrode adsorption block is fixed to the four corners of the top surface of the overlapping plate, and the iron core is fixed to the four corners of the bottom surface of the mounting plate.

3. The automatic alignment and assembly device for cylindrical battery electrode packs as described in claim 1, characterized in that: The positioning block is connected to the bidirectional drive mechanism, and the opening and closing of the V-shaped positioning block is controlled by the synchronous reverse motion of the bidirectional drive mechanism. The bidirectional drive mechanism includes a servo motor, a forward and reverse lead screw, and a threaded collar. The servo motor is connected to the forward and reverse lead screw through a drive rod, and the two ends of the forward and reverse lead screw have opposite rotation directions. The threaded collar is threaded onto both ends of the forward and reverse lead screw, and the top end is fixedly connected to the V-shaped positioning block. The bottom of the V-shaped positioning block cooperates with the sliding frame fixed to the placement platform through a sliding block.

4. The automatic alignment and assembly device for cylindrical battery electrode packs as described in claim 1, characterized in that: The supporting structure also includes an installation platform and a first electric telescopic rod. The installation platform is located at the bottom of the overlapping plate, and the first electric telescopic rod is disposed between the installation platform and the overlapping plate.

5. The automatic alignment and assembly device for cylindrical battery electrode packs as described in claim 4, characterized in that: It also includes a vision inspection system and a controller. The vision inspection system includes support rods supporting the installation platform, a second electric telescopic rod installed at the top of the support rods, a rotating mechanism set at the output end of the second electric telescopic rod, and a camera mounted on the rotating mechanism. The camera is used to scan the pole group's pose. The controller is electrically connected to the magnetic levitation mechanism, the mechanical clamping mechanism, and the camera, respectively, and is used to coordinate the levitation positioning and mechanical clamping actions.

6. A method for operating the automatic alignment and assembly device for cylindrical battery electrode packs as described in any one of claims 1-5, characterized in that: include: Powering on the magnetic levitation mechanism allows the pole group to levitate without contact above the placement platform; The position and angular deviation of the pole group are obtained through visual scanning; The electromagnetic field distribution of the magnetic levitation mechanism is adjusted according to the deviation parameters, and radial position compensation and tangential angle compensation are performed on the pole group. When the pole group's position reaches the set threshold, the positioning block of the mechanical clamping mechanism closes synchronously to clamp the pole group in contact.

7. The working method as described in claim 6, characterized in that: The adjustment of the magnetic levitation mechanism includes: generating a lateral fine-tuning force in the radial direction by independently controlling the current difference of the annular array electromagnetic units; and generating a rotational torque by generating a tangential electromagnetic field to correct the circumferential angle offset of the pole group.

8. The working method as described in claim 6, characterized in that: Visual scanning includes: controlling the camera to descend along the Z-axis to a preset height; driving the camera to rotate around the pole group to perform a spiral trajectory scan; and outputting the six-degree-of-freedom pose deviation parameters of the pole group based on laser triangulation and image processing algorithms.

9. The working method as described in claim 6, characterized in that: Controlling the closing of the V-shaped positioning block includes: dynamically adjusting the closing displacement according to the preset clamping force model; and correcting the clamping force in real time through feedback data from the clamping force sensor to ensure that the roundness error does not exceed the set threshold.

10. The working method as described in claim 6, characterized in that: The positional deviation parameter, electromagnetic field adjustment, and mechanical clamping action form a closed-loop control, and the closed-loop response time is less than the set threshold.

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