A roof welding system and a roof welding method thereof

Abstract

The application provides a top cover welding system and a top cover welding method thereof. The top cover welding system comprises a conveying device arranged between multiple processing stations and used for delivering workpieces to be processed from an upstream processing station to a downstream processing station in a preset direction; and multiple welding heads respectively arranged on the processing stations, each welding head being capable of completing welding of a partial weld along a preset welding track, and all the welding heads being capable of completing welding of all the welds. The welding method comprises the following steps: S10, sequentially feeding multiple workpieces to be processed into the top cover welding system; and S20, sequentially passing each workpiece to be processed through the multiple processing stations and completing welding of corresponding partial welds at each processing station, and when the workpiece to be processed passes through all the processing stations, welding of all the welds is completed. The top cover welding system and the top cover welding method thereof effectively solve the problems of slow welding speed and low efficiency of the battery top cover in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery production and manufacturing, in particular to a top cover welding system and a top cover welding method thereof. BACKGROUND

[0002] Batteries are widely used in today's technology products as a portable source of electrical energy. To protect the battery cell, the device using the battery and the user using the device, the battery cell is usually sealed and stored in a metal shell.

[0003] One of the current assembly methods is to place the cell in an open shell, then cover the top cover at the open place of the shell and weld the top cover at the open place of the shell to achieve the sealing effect. Usually in the welding process, the shell, the cell and the top cover remain stationary, and the welding equipment moves along the weld between the shell and the top cover, so that the welding head continuously completes the entire welding track.

[0004] The above welding method takes a long time to process a single workpiece, and the processing efficiency is low. Especially at the junction of two angled planes, due to factors such as hardware direction, acceleration and deceleration, too high welding speed may result in reduced weld quality, affecting product yield. SUMMARY

[0005] The present application aims to provide a top cover welding system and a top cover welding method thereof to solve the problem of slow welding speed and low efficiency of the battery top cover in the prior art.

[0006] In order to solve the above problems, the top cover welding system of the present application can weld the top cover of the workpiece on the shell of the workpiece, and the top cover and the shell have a weld therebetween. The top cover welding system specifically comprises: a conveying device arranged between a plurality of processing stations, for conveying the workpiece to be processed from an upstream processing station to a downstream processing station in a predetermined direction; a plurality of welding heads arranged on each processing station, each welding head being capable of completing the welding of part of the weld along a predetermined welding track, and all welding heads being capable of completing the welding of the entire weld.

[0007] Further, the welding track of part or all of the welding heads is greater than the length of the corresponding part of the weld, so that the two adjacent welding tracks partially overlap.

[0008] Further, the weld joint comprises first, second, third and fourth sections which are connected in sequence, wherein the first and third sections are oppositely arranged, the second section is connected at the tail end of the first section and the head end of the third section, and the fourth section is connected at the tail end of the third section and the head end of the first section; the plurality of welding heads comprises first, second, third and fourth welding heads, the first welding head is used for welding the first section, the second welding head is located downstream of the first welding head and is used for welding the third section, the third welding head is arranged downstream of the second welding head and is used for welding the second section, and the fourth welding head is arranged downstream of the second welding head and is used for welding the fourth section.

[0009] Further, the fourth welding head is arranged downstream of the third welding head.

[0010] Further, the third and fourth welding heads are arranged at the same station and are spaced apart by a preset distance, and the workpiece can pass between the third and fourth welding heads, so that the third and fourth welding heads can simultaneously weld the second and fourth sections.

[0011] Further, the roof welding system further comprises a turning device arranged between the second and third welding heads, so that the second section is directed towards the third welding head and the fourth section is directed towards the fourth welding head.

[0012] Further, the roof welding system further comprises first and second lasers, the first laser is connected to the first and third welding heads, and the second laser is connected to the second and fourth welding heads, and the first and second lasers are both time-and-light-sharing lasers.

[0013] Further, the third and fourth welding heads are both swing welding heads.

[0014] The application further provides a roof welding method of the roof welding system, the welding method comprising the following steps:

[0015] S10: sequentially feeding a plurality of workpieces to be processed into the roof welding system;

[0016] S20: sequentially passing each workpiece to be processed through a plurality of stations, and respectively completing welding of corresponding parts of the weld joint at each station, and when the workpiece to be processed passes through all the stations, welding of all the weld joints is completed.

[0017] Further, the step S20 specifically comprises:

[0018] S21: the first welding head welds the first section of the weld joint, and the completed workpiece is transferred to the second welding head;

[0019] S22: the second welding head welds the third section of the weld joint, and the completed workpiece is transferred to the third welding head;

[0020] S24: The third welding head welds the second segment of welds, and the finished workpiece is passed to the next process.

[0021] Further, step S24 specifically includes: the third welding head welds the second segment of welds, and the fourth welding head welds the fourth segment of welds, and the finished workpiece is passed to the next process.

[0022] In some embodiments, step S24 specifically includes: the third welding head welds the second segment of welds, and the finished workpiece is passed to the fourth welding head, and step S20 further includes: S25: the fourth welding head welds the fourth segment of welds, and the finished workpiece is passed to the next process.

[0023] Further, when multiple workpieces to be processed enter the top cover welding system, the workpiece to be processed later is completed with the welding process of step S24 during the passing process of step S21.

[0024] Further, between step S22 and step S24, there is further a step S23: rotating the workpiece.

[0025] The embodiments of the present application have the following beneficial effects:

[0026] The top cover welding system splits the welding track, divides the whole into parts, splits the traditional whole complex welding track into multiple independent welding tracks, and respectively processes in multiple workstations. Although the process of each workpiece is increased, the next workpiece to be processed can be processed in the previous workstation at the same time, so that multiple workpieces to be processed on the whole production line form a kind of dynamic synchronous welding in multiple workstations, which greatly improves the product production efficiency. On the other hand, the whole welding track is split and processed in different workstations, which helps to optimize the characteristics and needs of different tracks, so that the top cover welding system can improve the processing speed while ensuring product yield, and further improve the product processing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0028] Among them:

[0029] Figure 1 Fig. 1 shows the welding structure of the battery to be processed by the top cover welding system of the present application; and

[0030] Figure 2 A flow chart of the top cover welding system of the present application is shown.

[0031] The above figures contain the following reference numerals:

[0032] 21, first welding head; 22, second welding head; 23, third welding head; 24, fourth welding head; 31, first laser; 32, second laser; 40, welding seam; 41, first section; 42, second section; 43, third section; 44, fourth section; 51, first welding track; 52, second welding track; 53, third welding track; 54, fourth welding track. DETAILED DESCRIPTION

[0033] For the purpose of promoting an understanding of the present application, the present application will be described in greater detail below with reference to the illustrative drawings. The present application is illustrated by a preferred embodiment. However, the present application can be realized in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0034] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. The terms "vertical", "horizontal", "left", "right", and the like as used herein are for the purpose of illustration only.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] The top cover welding system of the present embodiment will be described below with reference to a battery being processed. The battery to be processed has a shell with an open end and a top cover capable of covering the opening. The battery is sealed and assembled by placing the battery cell in the shell and welding the top cover to the opening of the shell. The top cover welding system of the present embodiment is capable of welding the top cover of a workpiece to the shell of the workpiece along a welding seam between the top cover and the shell, thereby completing the sealing and assembling work.

[0037] As shown in FIG. 1, the top cover welding system of the present embodiment includes a welding head 20, a laser 30, and a control system 10. The welding head 20 is capable of welding the top cover of a workpiece to the shell of the workpiece along a welding seam between the top cover and the shell. The laser 30 is capable of generating a laser beam to melt the welding seam. The control system 10 is capable of controlling the welding head 20 and the laser 30. Figure 1As shown, the battery weld seam 40 to be processed in the embodiment is in the shape of a whole rectangle, which is split into the first segment 41, the second segment 42, the third segment 43 and the fourth segment 44 in a head-to-tail manner, wherein the first segment 41 and the third segment 43 are oppositely arranged, the second segment 42 is connected to the tail end of the first segment 41 and the head end of the third segment 42, and the fourth segment 44 is connected to the tail end of the third segment 43 and the head end of the first segment 41.

[0038] As shown in Figure 1 and Figure 2 The top cover welding system in the embodiment includes a conveying device (not shown in the figure) and four welding heads, wherein the conveying device is arranged between each processing station and is used to deliver the batteries from the upstream processing station to the downstream processing station in a preset direction. The four welding heads are respectively arranged in the corresponding processing stations, and each welding head can complete the welding of a partial weld seam along a respective preset welding track, and all the welding heads can complete the welding of the entire weld seam.

[0039] As shown in detail in Figure 2 The four welding heads are respectively the first welding head 21, the second welding head 22, the third welding head 23 and the fourth welding head 24. The first welding head 21 is used to weld the first segment 41. The second welding head 22 is located downstream of the first welding head 21 and is used to weld the third segment 43. The third welding head 23 is arranged downstream of the second welding head 22 and is used to weld the second segment 42. The fourth welding head 24 is arranged downstream of the second welding head 22 and is used to weld the fourth segment 44.

[0040] Figure 2 The batteries are transported by the conveying device in the direction M from left to right. a-g are schematic positions of the battery workpieces on the conveying device at each time according to the time T. A-E are five battery workpieces entering the top cover welding system in sequence. H is the spacing distance between adjacent two battery workpieces. The dashed line on the battery workpiece is a schematic of an un-welded weld seam, and the solid line is a schematic of a welded weld seam.

[0041] As shown in

[0042] a-b shows that the battery A completes the welding of the first segment 41 at the processing station where the first welding head 21 is located and moves out of the processing station under the driving of the conveying device. The battery B is ready to enter the welding process under the driving of the conveying device.

[0043] b-c shows that the battery A approaches the processing station where the second welding head 22 is located, and the battery B approaches the processing station where the first welding head 21 is located.

[0044] c-d show that the battery A completes the welding of the third section 43 in the processing station where the second welding head 22 is located and moves out of the processing station under the driving of the conveying device, the battery B completes the welding of the first section 41 in the processing station where the first welding head 21 is located and moves out of the processing station under the driving of the conveying device, and the battery C is ready to enter the welding process under the driving of the conveying device;

[0045] d-e show that the battery A completes the welding of the second section 42 and the fourth section 44 in the processing station where the third welding head 23 and the fourth welding head 24 are located and moves out of the processing station under the driving of the conveying device, the battery B approaches the processing station where the second welding head 22 is located, and the battery C approaches the processing station where the first welding head 21 is located;

[0046] e-f show that the battery A completes the welding of the weld 40 and exits the welding process, the battery B completes the welding of the third section 43 in the processing station where the second welding head 22 is located and moves out of the processing station under the driving of the conveying device, the battery C completes the welding of the first section 41 in the processing station where the first welding head 21 is located and moves out of the processing station under the driving of the conveying device, and the battery D is ready to enter the welding process under the driving of the conveying device;

[0047] f-g show that the battery B completes the welding of the second section 42 and the fourth section 44 in the processing station where the third welding head 23 and the fourth welding head 24 are located and moves out of the processing station under the driving of the conveying device, the battery C approaches the processing station where the second welding head 22 is located, and the battery D approaches the processing station where the first welding head 21 is located;

[0048] The subsequent battery E and other battery workpieces complete the welding work of the weld 40 in accordance with the above process.

[0049] By applying the technical solution of the embodiment, the top cover welding system splits the welding track, splits the traditional complete and complex welding track into multiple independent welding tracks, and respectively performs work in multiple stations. Although the process of each battery is increased, the next battery to be processed can be processed in the previous station at the same time, so that multiple batteries to be processed on the entire assembly line form a dynamic synchronous welding in multiple stations, that is, the processing time of the previous battery partially overlaps with the processing time of the next battery, without waiting for the complete welding of a battery before starting the welding work of the next battery, thereby avoiding the long processing time of a single battery in a station and reducing the running speed of the entire assembly line, and greatly improving the product production efficiency as a whole. On the other hand, splitting the complete welding track for processing in different stations helps to optimize the characteristics and needs of different tracks, so that the top cover welding system can improve the processing speed while ensuring the product yield, and further improve the product processing efficiency.

[0050] For example Figure 1The first segment 41 and the third segment 43 are straight lines. Although the welding distance is relatively long, the welding difficulty is relatively small. Under the premise of ensuring the welding effect, the welding speed can be increased and the welding time can be shortened. Figure 1 The second section 42 and the fourth section 44 contain two plane transitions forming a radius (R-angle). Although the welding difficulty is relatively high, the welding distance is relatively short. Slightly reducing the welding speed can still achieve a high welding effect in a shorter processing time.

[0051] To ensure the overall sealing effect of weld 40, such as Figure 1 As illustrated, in the top cover welding system of this embodiment, the length of the first welding trajectory 51 corresponding to the first welding head 21 is equivalent to the length of the first segment 41, and the length of the third welding trajectory 53 corresponding to the second welding head 22 is equivalent to the length of the third segment 43. The length of the second welding trajectory 52 corresponding to the third welding head 23 is greater than the length of the second segment 42, causing the second welding trajectory 52 and the first welding trajectory 51 to partially overlap, and the second welding trajectory 52 and the third welding trajectory 53 to partially overlap; similarly, the length of the fourth welding trajectory 54 corresponding to the fourth welding head 24 is greater than the length of the fourth segment 44, causing the fourth welding trajectory 54 and the first welding trajectory 51 to partially overlap, and the fourth welding trajectory 54 and the third welding trajectory 53 to partially overlap. The overlapping portion effectively avoids gaps caused by incomplete welding at the joint of the welding trajectories, which would affect the overall sealing effect of the battery.

[0052] In other embodiments not shown in the figures, the top cover welding system can process batteries or workpieces of other specifications and shapes, and can also adaptively adjust the length of the weld trajectory of each welding head to facilitate the adaptive allocation of processing time for each part of the weld, or adaptively adjust the distribution of overlapping parts of the weld on the workpiece.

[0053] It is understood that the top cover welding system of this embodiment divides the weld into four parts and configures four welding heads according to the shape structure of the rectangular battery. In other embodiments not shown in the figure, the number of welding heads and the number of weld divisions should be adaptively adjusted according to the shape characteristics of the workpiece to be processed, and should not be limited to four.

[0054] Preferably, in this embodiment, the third welding head 23 and the fourth welding head 24 are both oscillating welding heads. The welding method of galvanometer scanning flying welding can effectively solve the problems of slow welding speed and low welding quality of R-angle.

[0055] like Figure 2 As shown, in the top cover welding system of this embodiment, the third welding head 23 and the fourth welding head 24 are arranged at the same station and spaced apart by a preset distance (due to the limitations of the plan view, the third welding head 23 and the fourth welding head 24 do not overlap). Figure 2(For illustration only) The battery can pass between the third welding head 23 and the fourth welding head 24. In this way, when the battery passes through this station, the third welding head 23 and the fourth welding head 24 can simultaneously weld the second segment 42 and the fourth segment 44 from both sides of the battery, so that the second welding trajectory 52 connects between the first welding trajectory 51 and the third welding trajectory 53, and the fourth welding trajectory 54 connects between the first welding trajectory 51 and the third welding trajectory 53, so that the four welding trajectories completely cover the weld 40, achieving a seal.

[0056] To facilitate the welding operations of the third welding head 23 and the fourth welding head 24 and the spatial arrangement of various mechanisms in the top cover welding system, the top cover welding system of this embodiment also includes a steering device (not shown in the figure). The steering device is located between the second welding head 22 and the third welding head 23, so that the second segment 42 faces the third welding head 23 and the fourth segment 44 faces the fourth welding head 24.

[0057] Depending on the needs of subsequent processes, the top cover welding system of this embodiment may also be equipped with a steering device downstream of the fourth welding head 24, so that the welded battery returns to the direction before welding, or rotates to the direction that meets the subsequent processing requirements, so as to improve processing efficiency.

[0058] like Figure 2 As shown, the top cover welding system of this embodiment also includes a first laser 31 and a second laser 32. The first laser 31 is connected to the first welding head 21 and the third welding head 23, and the second laser 32 is connected to the second welding head 22 and the fourth welding head 24. Both the first laser 31 and the second laser 32 are time-division multiplexing lasers. The time-division multiplexing laser can emit laser light continuously and, as needed, direct it to one of the two welding heads. Connecting the first welding head 21 and the third welding head 23 at two different workstations to the first laser 31 simultaneously can effectively reduce the number of lasers. Furthermore, the laser orientation can be designed according to the working cycles of the first welding head 21 and the third welding head 23, utilizing the idle time of one to emit laser light to the other, reducing the idle time of the lasers and improving their utilization efficiency. The operation of the second laser 32 is similar to that of the first laser 31 and will not be described further.

[0059] As described above in the process flow description, Figure 2The process shown in the middle of d-e is the process that battery A exits and moves away from the processing station where the second welding head 22 is located, battery B approaches the processing station where the second welding head 22 is located, and battery C approaches the processing station where the first welding head 21 is located. During the time consumed in the above process, the first welding head 21 and the second welding head 22 are not working, battery A has just completed the welding of the third section 43, and batteries B and C have not entered the processing station. The top cover welding method of the embodiment utilizes the idle time to adjust the light paths of the first laser 31 and the second laser 32 to the third welding head 23 and the fourth welding head 24, and completes the welding work of the second section 42 and the fourth section 44. Thus, the utilization rate of the laser is improved, and the start-stop times of the laser are reduced. Moreover, the welding work of the second section 42 and the fourth section 44 can be completed in the idle time of the first welding head 21 and the second welding head 22 by adjusting the interval distance H, the conveying speed, and the welding speed, so as to avoid conflicts between the welding heads and ensure smooth operation of the top cover welding system.

[0060] In other embodiments of the top cover welding system not shown in the figure, if limited by space or structure, the third welding head and the fourth welding head cannot be arranged in the same station to weld the battery workpiece at the same time, and the fourth welding head can also be arranged downstream of the third welding head, that is, the four welding heads are arranged in sequence along the conveying direction of the battery, so that the second section and the fourth section of the same battery are welded in two stations respectively. The above structure can achieve the same welding effect, but may affect the overall welding time of a single battery.

[0061] The application also provides a top cover welding method that can be implemented by the above top cover welding system, comprising the following steps:

[0062] S10: sequentially feeding a plurality of workpieces to be processed into the top cover welding system;

[0063] S20: sequentially passing each workpiece to be processed through a plurality of stations, and respectively completing the welding of the corresponding partial welds at each station, and when the workpiece to be processed passes through all the stations, the welding of all the welds is completed.

[0064] Figure 2 The battery is transported by the conveying device in the direction M from left to right, a-g are the position diagrams of the battery workpiece at each time on the conveying device in the order of time T, A-E are five battery workpieces that sequentially enter the top cover welding system, H is the interval distance between adjacent two battery workpieces, and the dashed line in the battery workpiece schematically shows the un-welded weld, and the solid line schematically shows the welded weld.

[0065] In the figure

[0066] a-b shows: battery A completes the welding of the first segment 41 through the processing station where the first welding head 21 is located and moves out of the processing station under the drive of the conveying device, battery B is ready to enter the welding process under the drive of the conveying device;

[0067] b-c shows: battery A is close to the processing station where the second welding head 22 is located, battery B is close to the processing station where the first welding head 21 is located;

[0068] c-d shows: battery A completes the welding of the third segment 43 through the processing station where the second welding head 22 is located and moves out of the processing station under the drive of the conveying device, battery B completes the welding of the first segment 41 through the processing station where the first welding head 21 is located and moves out of the processing station under the drive of the conveying device, battery C is ready to enter the welding process under the drive of the conveying device;

[0069] d-e shows: battery A completes the welding of the second segment 42 and the fourth segment 44 through the processing station where the third welding head 23 and the fourth welding head 24 are located and moves out of the processing station under the drive of the conveying device, battery B is close to the processing station where the second welding head 22 is located, battery C is close to the processing station where the first welding head 21 is located;

[0070] e-f shows: battery A completes the welding of the weld 40 and exits the welding process, battery B completes the welding of the third segment 43 through the processing station where the second welding head 22 is located and moves out of the processing station under the drive of the conveying device, battery C completes the welding of the first segment 41 through the processing station where the first welding head 21 is located and moves out of the processing station under the drive of the conveying device, battery D is ready to enter the welding process under the drive of the conveying device;

[0071] f-g shows: battery B completes the welding of the second segment 42 and the fourth segment 44 through the processing station where the third welding head 23 and the fourth welding head 24 are located and moves out of the processing station under the drive of the conveying device, battery C is close to the processing station where the second welding head 22 is located, battery D is close to the processing station where the first welding head 21 is located;

[0072] Subsequent battery E and other battery workpieces follow the above process to complete the welding work of the weld 40.

[0073] Referring to the working process of the top cover welding system, the traditional complete complex welding track is split into multiple independent welding tracks by using the above top cover welding method, and is processed in multiple stations. Although the process of each battery is increased, the next battery to be processed can be processed in the previous station at the same time, so that multiple batteries to be processed on the whole assembly line form a dynamic synchronous welding in multiple stations, that is, the processing time of the previous battery partially overlaps with the processing time of the next battery, without waiting for the complete welding of a battery before starting the welding of the next battery, avoiding the long processing time of a single battery in a station, reducing the running speed of the whole assembly line, and greatly improving the product production efficiency. On the other hand, the complete welding track is split and processed in different stations, which is helpful for optimizing the characteristics and needs of different tracks, so that the top cover welding system can improve the processing speed while ensuring the product yield, and further improve the product processing efficiency.

[0074] The step S20 specifically includes the following steps:

[0075] S21: The first welding head welds the first welding seam, and the completed workpiece is transferred to the second welding head;

[0076] S22: The second welding head welds the third welding seam, and the completed workpiece is transferred to the third welding head;

[0077] S24: The third welding head welds the second welding seam, and the fourth welding head welds the fourth welding seam at the same time, and the completed workpiece is transferred to the downstream process.

[0078] The simultaneous welding of the second and fourth segments can shorten the total welding time of a single battery, and further improve the overall processing speed of the assembly line.

[0079] Preferably, when multiple workpieces to be processed enter the top cover welding system, the previous workpiece to be processed completes the welding process of step S24 during the transfer process of step S21.

[0080] As described above for the process flow, Figure 2 The process shown in d-e is the process that battery A exits and moves away from the processing station where the second welding head 22 is located, battery B approaches the processing station where the second welding head 22 is located, and battery C approaches the processing station where the first welding head 21 is located. During the time consumed in the above process, the first welding head 21 and the second welding head 22 are not working, battery A has just completed the welding of the third segment 43, and battery B and battery C have not entered the processing station. The top cover welding method of the present embodiment utilizes this idle time to adjust the optical paths of the first laser 31 and the second laser 32 to the third welding head 23 and the fourth welding head 24, and welds the second segment 42 and the fourth segment 44 of battery A.

[0081] That is, after the battery B completes the welding of the first section, in the process of approaching the second welding head 22, the battery A completes the welding of the second section 42 and the fourth section 44, and the battery C approaches the first welding head 21; after the battery C completes the welding of the first section, in the process of approaching the second welding head 22, the battery B completes the welding of the second section 42 and the fourth section 44, and the battery D approaches the first welding head 21, and so on to form a flow operation. The above process effectively improves the utilization rate of the laser and reduces the start-stop times of the laser.

[0082] And the welding of the second section 42 and the fourth section 44 can be completed in the idle time of the first welding head 21 and the second welding head 22 by adjusting the interval distance H, the conveying speed and the welding speed, so as to avoid conflicts between the welding heads and ensure the smooth operation of the top cover welding system.

[0083] In other embodiments, step S24 can also be: the third welding head welds the second section weld, and delivers the completed workpiece to the fourth welding head; correspondingly, step S20 further includes: S25: the fourth welding head welds the fourth section weld, and delivers the completed workpiece to the downstream process. That is, the four welding heads are arranged in sequence along the conveying direction of the battery, so that the second section and the fourth section of the same battery are welded in two stations respectively. The above structure can achieve the same welding effect, but may affect the overall welding time of a single battery.

[0084] To further improve the flexibility of the top cover welding system, in the top cover welding method of the embodiment, between step S22 and step S24, step S23: rotating the workpiece is further included. Rotating the workpiece can make the four sections of the battery weld substantially uniform, facilitate the directional arrangement of the welding heads in the top cover welding system, simplify the structure of the top cover welding system, and be conducive to improving the welding efficiency and effect of the weld.

[0085] It should be noted that the top cover welding system and the top cover welding method of the embodiment can process not only batteries but also other workpieces suitable for the above processing process, and are not limited to the welding processing of a single product of a battery. Moreover, the weld includes a first section, a second section, a third section and a fourth section connected in a loop, wherein the first section and the third section are oppositely arranged, the second section is connected to the tail end of the first section and the head end of the third section, and the fourth section is connected to the tail end of the third section and the head end of the first section. In different embodiments, the four-section weld can have different welding sequences, including but not limited to the following:

[0086] ① Weld the first section first, then weld the third section, then weld the second section, and finally weld the fourth section;

[0087] ② Weld the first section first, then weld the third section, and finally weld the second section and the fourth section synchronously;

[0088] ③ first joint welding first section, then welding second section, then welding third section, and finally welding fourth section;

[0089] ④ first joint welding first section, then synchronously welding second section and fourth section, and finally welding third section;

[0090] ⑤ first joint welding second section, then welding fourth section, then welding first section, and finally welding third section;

[0091] ⑥ first synchronously welding second section and fourth section, then welding first section, and finally welding third section;

[0092] ⑦ first joint welding second section, then welding first section, then welding fourth section, and finally welding third section;

[0093] ⑧ first joint welding second section, then welding first section, then welding third section, and finally welding fourth section.

[0094] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but it should be considered that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in a contradiction.

[0095] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A roof welding system capable of welding a roof of a workpiece to a shell of the workpiece with a weld joint between the roof and the shell, characterized by, The weld is in the shape of a rectangle as a whole, and the roof welding system comprises: a conveying device arranged between the plurality of processing stations and configured to convey the workpiece to be processed from an upstream processing station to a downstream processing station in a preset direction; a plurality of welding heads arranged at the respective processing stations, each of the welding heads being capable of completing welding of a portion of the weld along a respective preset welding track, and all of the welding heads being capable of completing welding of the entire weld; the weld comprises a first section, a second section, a third section and a fourth section which are connected end to end, wherein the first section and the third section are arranged oppositely, the second section is connected to the tail end of the first section and the head end of the third section, and the fourth section is connected to the tail end of the third section and the head end of the first section, the plurality of welding heads comprises a first welding head, a second welding head, a third welding head and a fourth welding head, the first welding head is configured to weld the first section, the second welding head is arranged downstream of the first welding head and configured to weld the third section, the third welding head is arranged downstream of the second welding head and configured to weld the second section, and the fourth welding head is arranged downstream of the second welding head and configured to weld the fourth section; the first section and the third section are straight lines with relatively long welding distances, and the second section and the fourth section comprise an R angle formed by two planar transitions with relatively short welding distances.

2. The roof welding system of claim 1, wherein, The welding track of part or all of the welding heads is greater than the length of the corresponding portion of the weld, so that two adjacent welding tracks partially overlap.

3. The roof welding system of claim 1, wherein, The fourth welding head is arranged downstream of the third welding head.

4. The roof welding system of claim 1, wherein, The third welding head and the fourth welding head are arranged at the same station and are spaced apart by a preset distance, the workpiece can pass between the third welding head and the fourth welding head, and the third welding head and the fourth welding head can simultaneously weld the second section and the fourth section.

5. The roof welding system of claim 1, wherein, The roof welding system further comprises a turning device arranged between the second welding head and the third welding head, so that the second section is directed towards the third welding head and the fourth section is directed towards the fourth welding head.

6. The roof welding system of claim 1, wherein, The roof welding system further comprises a first laser and a second laser, the first laser is connected to the first welding head and the third welding head, the second laser is connected to the second welding head and the fourth welding head, and the first laser and the second laser are both time and light sharing lasers.

7. The roof welding system of claim 1, wherein, The third welding head and the fourth welding head are both oscillating welding heads.

8. A roof welding method of the roof welding system according to any one of claims 1 to 7, characterized by, The weld is in the shape of a rectangle as a whole, the weld includes first, second, third and fourth sections which are connected in a head-to-tail manner, wherein the first and third sections are oppositely arranged, the second section is connected at the tail end of the first section and the head end of the third section, and the fourth section is connected at the tail end of the third section and the head end of the first section, the plurality of welding heads includes first, second, third and fourth welding heads, the first welding head is used for welding the first section, the second welding head is located downstream of the first welding head and is used for welding the third section, the third welding head is arranged downstream of the second welding head and is used for welding the second section, and the fourth welding head is arranged downstream of the second welding head and is used for welding the fourth section; The first and third sections are straight lines, the welding distance is relatively long, and the second and fourth sections include R angles formed by two plane transitions, and the welding distance is relatively short; The method comprises the following steps: S10: sequentially feeding a plurality of workpieces to be processed into a roof welding system; S20: sequentially passing each workpiece to be processed through a plurality of stations, and respectively completing welding of corresponding partial welds at each station, and when the workpiece to be processed passes through all the stations, welding of all the welds is completed; Step S20 specifically comprises the following steps: S21: the first welding head welds the first section of the weld, and the completed workpiece is transferred to the second welding head; S22: the second welding head welds the third section of the weld, and the completed workpiece is transferred to the third welding head; S24: the third welding head welds the second section of the weld, and the completed workpiece is transferred to the downstream process.

9. The method of welding a roof cap of claim 8, wherein, Step S24 specifically comprises: the third welding head welds the second section of the weld, and the fourth welding head welds the fourth section of the weld at the same time, and the completed workpiece is transferred to the downstream process.

10. The method of welding a roof cap of claim 8, wherein, Step S24 specifically comprises: the third welding head welds the second section of the weld, and the completed workpiece is transferred to the fourth welding head, and step S20 further comprises the following step: S25: the fourth welding head welds the fourth section of the weld, and the completed workpiece is transferred to the downstream process.

11. The method of welding a roof according to any one of claims 8 to 10, wherein, When a plurality of workpieces to be processed enter the roof welding system, the workpiece to be processed in the front is completed in the welding process of step S24 during the transfer process of step S21.

12. The method of welding a roof according to any one of claims 8 to 10, wherein, Step S22 and step S24 further comprise the following step: S23: rotating the workpiece.

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