Lithium battery welding equipment and welding method

Abstract

The present invention belongs to the technical field of lithium battery processing, and specifically relates to a lithium battery welding device and a welding method, comprising a positioning base, an outer cover is fixed on the positioning base, a three-axis motion guide rail is arranged in the outer cover, a laser welding head is arranged on the three-axis motion guide rail, a lithium battery pack is arranged on the positioning base, a connecting piece is arranged on the electrode of the lithium battery pack, and also comprises: a flattening mechanism, the flattening mechanism comprises a pressing plate fixed on the three-axis motion guide rail, the bottom of the pressing plate is movably connected with the top of the connecting piece, and a first contact sensor is arranged on the three-axis motion guide rail; by arranging the flattening mechanism, during the welding process, the pressing plate fixes the connecting piece, and the driving member drives the pressure roller to move through the U-shaped frame to flatten the connecting piece, thereby increasing the contact area between the connecting piece and the lithium battery electrode, thereby improving the welding quality between the connecting piece and the lithium battery electrode, and reducing the generation of resistance at the connection.

Description

Technical Field

[0001] The invention belongs to the field of lithium battery processing, and specifically relates to lithium battery welding equipment and a welding method. Background Art

[0002] Lithium battery is a rechargeable battery that can be charged and discharged repeatedly. It is often used in various portable electronic devices and new energy vehicles. The lithium battery in the new energy vehicle field is powered by a battery pack formed by multiple lithium batteries connected in series. The lithium batteries are first assembled into a lithium battery pack, and then a connecting piece is placed between the electrodes of two adjacent lithium batteries. The connecting piece can be made of conductive polymer. After the whole connecting piece is produced, it needs to be cut into connecting pieces of corresponding sizes. The lithium battery packs are connected in series, and the connecting pieces are connected to the electrodes of the lithium batteries by laser welding.

[0003] A patent document with publication number CN117182309B discloses a large-capacity lithium battery laser welding equipment, which transports the lithium battery to the specified position through a conveying module, and the cylinder drives the positioning wheel frame to move upward on both sides of the lithium battery. The positioning wheel frame positions the lithium battery, and the pressing frame and the limiting clamp block move on the surface of the connecting piece to limit and fix the connecting piece. The welding mechanism welds and fixes the connecting piece to the lithium battery electrode.

[0004] In the above scheme, the connecting piece is positioned and fixed by the pressing frame and the limiting clamp block. When the connecting piece is made of conductive polymer, due to the soft texture of the conductive polymer, the edge position of the connecting piece after cutting will be deformed downward. After the connecting piece is placed on the electrode, the middle will bulge upward, and a gap will be generated between the connecting piece and the electrode of the lithium battery. The pressing frame is only pressed on the top of the connecting piece, and the contact area between the pressing frame and the connecting piece is small. The pressing frame cannot press the connecting piece flat. During laser welding, due to the gap between the connecting piece and the electrode, after the energy of laser welding is transferred to the connecting piece, the energy cannot be transferred from the connecting piece to the electrode of the lithium battery in time, resulting in the inability of laser welding to fuse the connecting piece and the electrode of the lithium battery together. The welding point area between the connecting piece and the lithium battery is small, the welding quality is low, and the resistance during current transmission is increased. For this reason, the present invention provides a lithium battery welding device and a welding method. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a lithium battery welding device described in the present invention comprises a positioning base, an outer cover is fixed on the positioning base, a three-axis motion guide rail is arranged in the outer cover, a laser welding head is arranged on the three-axis motion guide rail, a lithium battery pack is arranged on the positioning base, and a connecting piece is arranged on the electrode of the lithium battery pack, and further comprises:

[0007] A flattening mechanism, the flattening mechanism comprises a pressing plate fixed on a three-axis motion guide rail, the bottom of the pressing plate is movably connected to the top of the connecting piece, a first contact sensor is arranged on the three-axis motion guide rail, a flattening assembly is arranged in the pressing plate, the flattening assembly comprises a driving member embedded in the pressing plate, a U-shaped frame movably connected to the pressing plate is fixed to the output end of the driving member, a pressing roller and a locking assembly are arranged in the U-shaped frame, and the pressing roller is used to flatten the connecting piece on the lithium battery pack;

[0008] The detection component includes a second contact sensor fixed in the U-shaped frame, which is used to detect whether the connecting piece on the lithium battery pack is flattened.

[0009] Preferably, a connecting block is movably connected inside the U-shaped frame, the connecting block is rotatably connected to the pressure roller via a round rod, and a spring fixedly connected to the inner wall of the U-shaped frame is fixed on the connecting block.

[0010] Preferably, a guide rod fixed to the inner wall of the U-shaped frame is movably inserted into the connecting block, and the guide rod is used to improve the stability of the connecting block in the vertical direction.

[0011] Preferably, the locking assembly includes a block movably connected in a U-shaped frame, a plug block fixed on the surface of the block and clamped in a groove of the connecting block, a first guide rod and a second guide rod fixed in the pressure plate, the second guide rod inserted in the U-shaped frame and resting against the surface of the block.

[0012] Preferably, a T-shaped slider movably connected to the U-shaped frame is fixed at the bottom of the block, and the T-shaped slider is used to improve the stability of the block during horizontal movement.

[0013] Preferably, the moving distance of the block is greater than the depth of the plug-in block inserted into the groove of the connecting block, thereby ensuring that the plug-in block can be completely disengaged from the groove of the connecting block.

[0014] Preferably, the detection component also includes an audible and visual alarm fixed on the pressure plate, a rotating shaft is fixed in the U-shaped frame, a bent rod is rotatably connected in the U-shaped frame via the rotating shaft, the curved end of the bent rod is movably connected to the side plate of the connecting block, and a tension spring connected to the inner wall of the pressure plate is fixed on the top of the bent rod.

[0015] Preferably, the rotating axis is located at one-third of the curved end of the bent rod.

[0016] A lithium battery welding method, which uses the lithium battery welding equipment described above, comprises the following steps:

[0017] Step 1: Place the lithium battery pack on the positioning base, and place the connecting piece on the electrode of the lithium battery pack;

[0018] Step 2: Use the positioning base to drive the lithium battery pack to move below the three-axis motion guide rail, and use the positioning base to position the lithium battery pack;

[0019] Step 3: Start the three-axis motion guide rail, which drives the laser welding head to move directly above the connecting piece;

[0020] Step 4: The three-axis motion guide rail triggers the flattening component to flatten the connecting piece, and the detection component detects whether the connecting piece is flattened;

[0021] Step 5: When the detection component detects that the connecting piece has been flattened, the laser welding head is started to weld the connecting piece and the electrode of the lithium battery pack; when the detection component detects that the connecting piece is not flattened, step 4 is repeated until the connecting piece is flattened;

[0022] Step 6: The three-axis motion guide rail drives the flattening mechanism to move upward, and the positioning base releases the positioning of the lithium battery pack. The positioning base drives the lithium battery pack to move right out of the outer cover, and the lithium battery pack is removed.

[0023] Preferably, the three-axis motion guide rail triggers the first contact sensor when moving downward, and the flattening assembly is started through the first contact sensor.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The lithium battery welding equipment and welding method described in the present invention, by setting a flattening mechanism, during the welding process, the pressure plate fixes the connecting piece, and the driving member drives the pressure roller to move through the U-shaped frame to flatten the connecting piece, thereby increasing the contact area between the connecting piece and the lithium battery electrode, thereby improving the welding quality between the connecting piece and the lithium battery electrode and reducing the generation of resistance at the connection.

[0026] 2. The lithium battery welding equipment and welding method described in the present invention detect the flatness of the connecting piece by setting a second contact sensor and an audible and visual alarm, and cooperating with the second contact sensor and a pressure roller, thereby reducing the possibility of the connecting piece bulging again due to plasticity, thereby further improving the welding quality.

[0027] 3. A lithium battery welding device and welding method described in the present invention, by setting a bending rod, the connecting block triggers the second contact sensor through the bending rod, the connecting block moves upward a short distance to drive one end of the bending rod to move upward a distance, the bending rod rotates, and the other end of the bending rod will move downward a larger distance, by enlarging the moving distance, thereby improving the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 It is a schematic diagram of the overall structure;

[0030] Figure 2 It is a schematic diagram of the internal structure of the outer cover;

[0031] Figure 3 It is a schematic diagram of the structure of the three-axis motion guide rail and the flattening mechanism;

[0032] Figure 4 It is a schematic diagram of the structure at the U-shaped frame;

[0033] Figure 5 It is a schematic diagram of the structure of the driving part;

[0034] Figure 6 It is a schematic diagram of the overall structure of the U-shaped frame;

[0035] Figure 7 2. It is a schematic diagram of the structure of the first guide rod and the second guide rod;

[0036] Figure 8 It is a schematic diagram of the structure at the plug-in block;

[0037] Fig. 9 Schematic diagram of the structure at the guide rod;

[0038] Fig.10 It is a schematic diagram of the structure at the T-shaped slider;

[0039] Fig.11 It is a schematic diagram of the structure at the block;

[0040] In the figure: 1. positioning base; 2. outer cover; 3. lithium battery pack; 4. three-axis motion guide rail; 5. laser welding head; 6. flattening mechanism; 61. pressure plate; 62. first contact sensor; 63. flattening assembly; 631. driving member; 632. U-shaped frame; 633. connecting block; 634. pressure roller; 635. guide rod; 636. spring; 64. locking assembly; 641. block; 642. plug block; 643. T-shaped slider; 644. first guide rod; 645. second guide rod; 7. detection assembly; 71. bending rod; 72. tension spring; 73. second contact sensor; 74. sound and light alarm; 75. rotating shaft; 8. connecting piece. DETAILED DESCRIPTION

[0041] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0042] Embodiment 1

[0043] like Figure 1-11 As shown, a lithium battery welding device described in an embodiment of the present invention includes a positioning base 1, an outer cover 2 is fixed on the positioning base 1, the positioning base 1 is composed of a base, a conveying module, a cylinder and a positioning wheel frame, the base plays a role of supporting on the ground, the conveying module is used to move the lithium battery group 3, wherein the conveying module is composed of a reduction motor, a conveyor belt and rollers, the lithium battery group 3 is placed on the belt supported by the rollers, the connecting piece 8 is placed above the electrodes of two adjacent lithium batteries in the lithium battery group 3, the connecting piece 8 forms a series circuit with the lithium battery group 3, the reduction motor drives the rollers to rotate, the rollers drive the belts to rotate, the belts will drive the lithium battery group 3 to move, when the lithium battery group 3 moves to the specified position, the cylinder drives the positioning wheel frame to move upward, the rollers on the positioning wheel frame will be clamped on the surface of the lithium battery group 3 , the roller positions the lithium battery pack 3, a three-axis motion guide rail 4 is arranged in the outer cover 2, the three-axis motion guide rail 4 can move in the XYZ axis direction, the three-axis motion guide rail 4 is divided into an X-axis guide rail, a Y-axis guide rail and a Z-axis guide rail, and the X-axis guide rail, the Y-axis guide rail and the Z-axis guide rail are all connected by a servo motor drive, and the three-axis motion guide rail 4 drives the laser welding head 5 to move and position, and the laser welding head 5 is used in conjunction with the welding machine. When the three-axis motion guide rail 4 drives the laser welding head 5 to move above the connecting piece 8, the laser welding head 5 emits a laser beam to act on the connecting piece 8 to realize the welding connection between the connecting piece 8 and the electrode of the lithium battery pack 3, the three-axis motion guide rail 4 is provided with a laser welding head 5, the positioning base 1 is provided with a lithium battery pack 3, and the electrode of the lithium battery pack 3 is provided with a connecting piece 8, and also includes:

[0044] The flattening mechanism 6 includes a pressing plate 61 fixed on the three-axis motion guide rail 4, and the bottom of the pressing plate 61 is movably connected to the top of the connecting piece 8. When the pressing plate 61 is in use, the pressing plate 61 is pressed on both sides of the upper surface of the connecting piece 8 to prevent the pressing plate 61 from affecting the welding of the connecting piece 8. There are four connecting rods in total, and the pressing plate 61 is fixed horizontally by the connecting rods. A through hole is provided on the pressing plate 61, and the position of the through hole corresponds to the position of the connecting piece 8. A first contact sensor 62 is provided on the three-axis motion guide rail 4, and the first contact sensor 62 is located on the surface of the Z-axis guide moving part of the three-axis motion guide rail 4. When the three-axis motion guide rail 4 is in use, the X-axis guide of the three-axis motion guide rail 4 contacts the first contact sensor 62 and continues to move downward. When the X-axis guide is out of contact with the first contact sensor 62, the X-axis guide is out of contact with the first contact sensor 62. At the moment when the first contact sensor 62 is touched, the first contact sensor 62 will issue a command, and the first contact sensor 62 will start the driving member 631 in the flattening mechanism 6. The pressing plate 61 is provided with a flattening assembly 63. The flattening assembly 63 includes a driving member 631 embedded in the pressing plate 61. The driving member 631 can be an electric push rod, etc. The driving member 631 drives the U-shaped frame 632, and the U-shaped frame 632 drives the pressure roller 634 to move. The pressure roller 634 rolls on the surface of the connecting piece 8, and the connecting piece 8 is flattened by the pressure roller 634. The output end of the driving member 631 is fixed with a U-shaped frame 632 movably connected to the pressing plate 61, and the U-shaped frame 632 is provided with a pressure roller 634 and a locking assembly 64. The pressure roller 634 is used to flatten the connecting piece 8 on the lithium battery pack 3;

[0045] Detection component 7, detection component 7 includes a second contact sensor 73 fixed in the U-shaped frame 632, which is used to detect whether the connecting piece 8 on the lithium battery pack 3 is flattened. The three-axis motion guide rail 4 drives the laser welding head 5 to move downward, and the X-axis guide rail in the three-axis motion guide rail 4 moves downward to trigger the first contact sensor 62. The first contact sensor 62 sends a command to start the flattening mechanism 6. The X-axis guide rail and the Y-axis guide rail in the three-axis motion guide rail 4 move vertically through the Z-axis guide rail. The X-axis guide rail and the Y-axis guide rail of the three-axis motion guide rail 4 also drive the laser welding head in the horizontal direction 5 is moved horizontally, and the laser welding head 5 is moved just above the connecting piece 8. When the detection component 7 detects that the connecting piece 8 is flat, the laser welding head 5 emits a laser beam to weld the connecting piece 8 to the electrode of the lithium battery pack 3. After the welding of multiple connecting pieces 8 is completed, the Z-axis guide rail in the three-axis motion guide rail 4 drives the pressing plate 61 to move upward, and the cylinder drives the positioning wheel frame to move downward and separate from the lithium battery pack 3. The reduction motor is started, the reduction motor drives the roller to rotate, the roller drives the belt to rotate, and the belt conveys the lithium battery pack 3 to the right, and the lithium battery pack 3 is taken down.

[0046] Specifically, the connecting piece 8 can be flattened by the flattening component 63 in the flattening mechanism 6. After the connecting piece 8 is flattened, the flattened connecting piece 8 is inspected by the detection component 7. When the connecting piece 8 bulges again due to plasticity, it can be detected by the detection component 7. After detecting that the connecting piece 8 is not flat, the flattening component 63 can be started again, and the flattening component 63 flattens the connecting piece again.

[0047] like Figure 4 , Figure 5 , Figure 6 , Fig. 9 , Fig.10 and Fig.11 As shown, a connecting block 633 is movably connected inside the U-shaped frame 632 , and the connecting block 633 is rotatably connected to the pressure roller 634 via a round rod. A spring 636 fixedly connected to the inner wall of the U-shaped frame 632 is fixed on the connecting block 633 .

[0048] Specifically, the connecting block 633 moves up and down in the vertical direction, the round rod is vertically arranged between the connecting block 633, and the pressure roller 634 is in a horizontal state when fixed. Only when the pressure roller 634 is in a horizontal state can the connecting piece 8 be flattened. When the locking assembly 64 on the side of the connecting block 633 is unlocked, the connecting block 633 can move upward. After the connecting block 633 moves upward, the connecting block 633 is reset by its own gravity and the elastic force of the spring 636.

[0049] like Figure 4 , Figure 5 , Figure 6 , Fig. 9 , Fig.10 and Fig.11 As shown, a guide rod 635 fixed to the inner wall of the U-shaped frame 632 is movably inserted into the connecting block 633 , and the guide rod 635 is used to improve the stability of the connecting block 633 moving in the vertical direction.

[0050] Specifically, the guide rod 635 is vertically arranged, and the bottom of the guide rod 635 is inserted into the guide hole at the top of the connecting block 633. The connecting block 633 will be positioned by the guide rod 635 during the upward movement, so as to avoid the connecting block 633 from being displaced in the horizontal direction and avoiding the connecting block 633 from being stuck.

[0051] like Figure 4 , Figure 7 , Figure 8 and Fig.11 As shown, the locking assembly 64 includes a block 641 movably connected in the U-shaped frame 632, a plug block 642 fixed on the surface of the block 641 and clamped in the groove of the connecting block 633, a first guide rod 644 and a second guide rod 645 fixed in the pressure plate 61, and the second guide rod 645 is inserted in the U-shaped frame 632 and rests on the surface of the block 641.

[0052] Specifically, after the plug block 642 is clamped in the groove of the connecting block 633, the connecting block 633 is in a locked state. At this time, the connecting block 633 cannot move up and down in the vertical direction. The pressure roller 634 on the connecting block 633 flattens the connecting piece 8 while moving on the connecting piece 8; after the plug block 642 is separated from the groove of the connecting block 633, the connecting block 633 is in an unlocked state. The connecting block 633 can move up and down in the vertical direction. The pressure roller 634 on the connecting block 633 cooperates with the detection component 7 to detect whether the connecting piece 8 is flat. The locking component 64 adopts a mechanical structure to realize the locking of the connecting block 633. The laser beam emitted by the laser welding head 5 welds the connecting piece 8 to the electrode of the lithium battery pack 3, and heat radiation will be generated at the welding place. If a solenoid valve or other technology is used to replace the locking component 64, the heat radiation will act on the surface of the solenoid valve, and the heat radiation will damage the solenoid valve. The solenoid valve is easy to be damaged during use. The use of a small mechanical structure to realize the locking function is simpler, and the heat radiation cannot cause damage to the mechanical structure, thereby increasing the overall durability during use.

[0053] like Fig.10 and Fig.11 As shown, a T-shaped slider 643 movably connected to the U-shaped frame 632 is fixed at the bottom of the block 641, and the T-shaped slider 643 is used to improve the stability of the block 641 during horizontal movement.

[0054] Specifically, the T-shaped slider 643 slides in the U-shaped frame 632. The T-shaped slider 643 can only move in the horizontal direction, and the T-shaped slider 643 cannot move in the vertical direction. The T-shaped slider 643 guides the block 641 so that the block 641 will not get stuck during horizontal movement. When the block 641 is subjected to a force in the vertical direction, the T-shaped slider 643 can also share a part of the force in the vertical direction, so that the block 641 will not break easily during use, and the block 641 will be more firmly used, thereby increasing the durability of the block 641 during use.

[0055] like Figure 4 , Figure 7 , Figure 8 and Fig.11 As shown, the moving distance of the block 641 is greater than the depth of the insert block 642 inserted into the groove of the connecting block 633 , ensuring that the insert block 642 can be completely disengaged from the groove of the connecting block 633 .

[0056] Specifically, the block 641 drives the plug block 642 to move, the length of the plug block 642 is adapted to the depth of the groove of the connecting block 633, and the size of the plug block 642 is also adapted to the groove of the connecting block 633. After the plug block 642 is inserted into the groove of the connecting block 633, the connecting block 633 cannot move up and down, thereby improving the stability of the connecting block 633 after being locked, so that the pressure roller 634 connected to the connecting block 633 can achieve a better flattening effect when flattening the connecting sheet 8.

[0057] like Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 and Fig.11 As shown, the detection component 7 also includes a sound and light alarm 74 fixed on the pressure plate 61, a rotating shaft 75 is fixed in the U-shaped frame 632, a bending rod 71 is rotatably connected to the U-shaped frame 632 through the rotating shaft 75, the curved end of the bending rod 71 is movably connected to the side plate of the connecting block 633, and a tension spring 72 connected to the inner wall of the pressure plate 61 is fixed on the top of the bending rod 71.

[0058] Specifically, when the long side of the bent rod 71 contacts the second contact sensor 73, the second contact sensor 73 issues an instruction, and the second contact sensor 73 will control the sound and light alarm 74 to sound an alarm, and the second contact sensor 73 will also issue an instruction to reset the flattening component 63 and start it again until the connecting piece 8 is flattened, wherein the bent rod 71 rotates through the rotating shaft 75. After the rotating shaft 75 rotates, it is reset by the tension of the tension spring 72. The tension of the tension spring 72 is greater than the gravity of the bent rod 71, thereby avoiding the situation where the tension spring 72 cannot reset the bent rod 71.

[0059] like Figure 4 , Fig. 9 and Fig.11 As shown, the rotating shaft 75 is located at one-third of the curved end of the bending rod 71.

[0060] Specifically, after the rotating shaft 75 is located at one-third of the bending rod 71, when the short side of the bending rod 71 moves upward a short distance, the long side of the bending rod 71 will move downward twice the distance. When the protrusion on the connecting piece 8 is small, the smaller protrusion will be magnified through the bending rod 71 to better judge the amplitude of the protrusion.

[0061] Embodiment 2

[0062] A lithium battery welding method, which uses the lithium battery welding equipment described above, comprises the following steps:

[0063] Step 1: The lithium battery pack 3 is placed on the positioning base 1, and the connecting piece 8 is placed on the electrode of the lithium battery pack 3;

[0064] Step 2: The lithium battery pack 3 is driven to move to the bottom of the three-axis motion guide rail 4 by the positioning base 1, and the lithium battery pack 3 is positioned by the positioning base 1;

[0065] Step 3: Start the three-axis motion guide rail 4, and the three-axis motion guide rail 4 drives the laser welding head 5 to move to the top of the connecting piece 8;

[0066] Step 4: The three-axis motion guide rail 4 triggers the flattening component 63 to flatten the connecting piece 8, and the detection component 7 detects whether the connecting piece 8 is flattened;

[0067] Step 5: When the detection component 7 detects that the connecting piece 8 has been flattened, the laser welding head 5 is started to weld the connecting piece 8 and the electrode of the lithium battery pack 3; when the detection component 7 detects that the connecting piece 8 has not been flattened, step 4 is repeated until the connecting piece 8 is flattened;

[0068] Step 6: The three-axis motion guide rail 4 drives the flattening mechanism 6 to move upward, and the positioning base 1 releases the positioning of the lithium battery pack 3. The positioning base 1 drives the lithium battery pack 3 to move rightward out of the outer cover 2, and the lithium battery pack 3 is removed.

[0069] The three-axis motion guide rail 4 triggers the first contact sensor 62 when moving downward, and the flattening component 63 is started through the first contact sensor 62 .

[0070] Specifically, the connecting piece 8 is pressed and fixed by the pressing plate 61, and the flattening component 63 flattens the connecting piece 8, so that the welding quality of the connecting piece 8 is higher after welding. The detection component 7 performs flatness detection on the flattened connecting piece 8 to prevent the connecting piece 8 from bulging again due to plasticity, thereby increasing the contact area of ​​the connecting piece 8 during welding, improving the quality after welding, and reducing the resistance of current flow at the welding point.

[0071] Working principle: place the connecting piece 8 on the electrode surface of the lithium battery pack 3, place the lithium battery pack 3 on the conveying module of the positioning base 1, drive the lithium battery pack 3 to move through the conveying module, after the lithium battery moves into the outer cover 2, start the cylinder on the positioning base 1, the cylinder drives the positioning wheel frame to move upward, the positioning wheel frame is clamped on the surface of the lithium battery through the roller, and the lithium battery is limited, and the three-axis motion guide rail 4 is started. The three-axis motion guide rail 4 drives the laser welding head 5 to move, so that the laser welding head 5 is positioned above the connecting piece 8, and the Y-axis guide rail of the three-axis motion guide rail 4 moves downward, first contacting the first contact sensor 62, when the Y-axis guide rail of the three-axis motion guide rail 4 moves downward and leaves the first contact sensor 62, the pressing plate 61 just presses on the connecting piece 8 on the lithium battery pack 3, and the connecting piece 8 is fixed by the pressing plate 61, and then the first contact sensor 62 will issue an instruction, and the first contact sensor 62 will start the driving member 631, and the driving member 631 drives the U-shaped frame 632 to move, and the U-shaped frame 632 drives the pressure roller 634 to move through the connecting block 633 and the round rod. The pressure roller 634 rolls on the surface of the connecting piece 8, and the upward protrusion of the connecting piece 8 is flattened by the rolling of the pressure roller 634. When the pressure roller 634 completes the rolling of the connecting piece 8, the first guide rod 644 will be inserted into the U-shaped frame 632 and contact with the block 641. The first guide rod 644 will be against the surface of the block 641, and the block 641 will stop moving. , but the U-shaped frame 632 continues to move, the block 641 will drive the insert block 642 to move out of the groove of the connecting block 633, the T-shaped slider 643 at the bottom of the block 641 will slide in the U-shaped frame 632, and the connecting block 633 will be unlocked. At this time, the driving member 631 extends the maximum stroke, and the driving member 631 will drive the U-shaped frame 632 to return. The U-shaped frame 632 will drive the pressure roller 634 to move again through the connecting block 633 and the round rod, and the pressure roller 634 rolls on the surface of the connecting piece 8;

[0072] When the connecting piece 8 is flattened by the pressure roller 634 and the connecting piece 8 does not bulge again due to plasticity, the pressure roller 634 will not move upwards while rolling on the connecting piece 8, and the pressure roller 634 will not drive the connecting block 633 to move upwards through the round rod, and the flat plate on the side of the connecting block 633 will not drive the bending rod 71 in the detection mechanism to rotate. If the bending rod 71 does not rotate, it will not contact the second contact sensor 73, and the second contact sensor 73 will not be triggered, which means that the connecting piece 8 is in a flat state.

[0073] When the connecting piece 8 is rolled flat by the pressure roller 634, the connecting piece 8 bulges upward again due to plasticity. At this time, after the pressure roller 634 contacts the bulging position of the connecting piece 8, the pressure roller 634 will drive the round rod to move upward, and the round rod will drive the connecting block 633 to move upward. The connecting block 633 will drive one end of the bent rod 71 to tilt upward through the flat plate on the side. The bent rod 71 rotates through the rotating shaft 75, and the other end of the bent rod 71 will move downward, and the bent rod 71 will contact the second contact sensor 73. The second contact sensor 73 will move upward. 3 issues a command, and the sound and light alarm 74 receives the command, and the sound and light alarm 74 will sound an alarm, indicating that the connecting piece 8 has a protrusion, and the central control system will receive the command of the second contact sensor 73, and will issue a command. When the driving member 631 retracts to the bottom, the driving member 631 will drive the U-shaped frame 632 to move again, and the pressure roller 634 will roll the connecting piece 8 again. The driving member 631 continues to drive the U-shaped frame 632 to move. When the pressure roller 634 moves out of the protruding position of the connecting piece 8, the spring 63 6 will drive the connecting block 633 to move downward and reset, and when the connecting block 633 moves up and down in the vertical direction, the connecting block 633 is guided by the guide rod 635, and the connecting block 633 is more stable in the vertical movement, and the bending rod 71 will be reset by the tension spring 72. When the driving member 631 is about to retract to the bottom, the second guide rod 645 is located in the U-shaped frame 632, and the second guide rod 645 will contact the block 641, and the second guide rod 645 will be against the surface of the block 641, and the U-shaped frame 632 continues to When the connecting block 633 is driven to move, the connecting block 633 contacts the plug block 642, and the connecting block 633 is sleeved on the surface of the plug block 642 through the side groove. After that, the connecting block 633 will not be able to move up and down in the vertical direction, and the connecting block 633 is in a locked state. At this time, the driving member 631 is started again, and the driving member 631 drives the U-shaped frame 632 to move toward the connecting piece 8 again. The flattening mechanism 6 and the detection component 7 will flatten and detect the connecting piece 8 again until the connecting piece 8 is flat;

[0074] After the connecting piece 8 is rolled flat, the laser welding head 5 is started, and the connecting piece 8 and the electrode of the lithium battery pack 3 are welded through the laser welding head 5. The soot generated during welding will be sucked outward through the exhaust fan on the outer cover 2. After the welding is completed, the three-axis motion guide rail 4 drives the laser welding head 5 to reset upward, and the pressure plate 61 is separated from the surface of the connecting piece 8. The cylinder in the positioning base 1 is started, and the cylinder drives the positioning wheel frame to move downward. After the positioning wheel frame is separated from the lithium battery pack 3, the conveying module on the positioning base 1 is started to move the lithium battery pack 3 out, remove the lithium battery pack 3, and then place a new lithium battery pack 3 on the positioning base 1, and repeat the above steps.

[0075] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A lithium battery welding device, comprising a positioning base (1), an outer cover (2) fixed on the positioning base (1), a three-axis motion guide rail (4) arranged inside the outer cover (2), a laser welding head (5) arranged on the three-axis motion guide rail (4), a lithium battery pack (3) arranged on the positioning base (1), and a connecting piece (8) arranged on the electrode of the lithium battery pack (3), characterized in that: Also includes: A flattening mechanism (6), the flattening mechanism (6) comprising a pressing plate (61) fixed on a three-axis motion guide rail (4), the bottom of the pressing plate (61) being movably connected to the top of a connecting piece (8), a first contact sensor (62) being provided on the three-axis motion guide rail (4), a flattening assembly (63) being provided in the pressing plate (61), the flattening assembly (63) comprising a driving member (631) embedded in the pressing plate (61), a U-shaped frame (632) movably connected in the pressing plate (61) being fixed at the output end of the driving member (631), a pressing roller (634) and a locking assembly (64) being provided in the U-shaped frame (632), the pressing roller (634) being used for flattening the connecting piece (8) on the lithium battery pack (3); A detection component (7), the detection component (7) comprising a second contact sensor (73) fixed in the U-shaped frame (632) and used for detecting whether the connecting piece (8) on the lithium battery pack (3) is flattened; A connecting block (633) is movably connected inside the U-shaped frame (632), the connecting block (633) is rotatably connected to the pressure roller (634) via a round rod, and a spring (636) fixedly connected to the inner wall of the U-shaped frame (632) is fixed on the connecting block (633); A guide rod (635) fixed to the inner wall of the U-shaped frame (632) is movably plugged into the connecting block (633), and the guide rod (635) is used to improve the stability of the connecting block (633) moving in the vertical direction; The locking assembly (64) comprises a block (641) movably connected in the U-shaped frame (632), an insert block (642) fixed on the surface of the block (641) and clamped in the groove of the connecting block (633), a first guide rod (644) and a second guide rod (645) fixed in the pressure plate (61), the second guide rod (645) inserted in the U-shaped frame (632) and abutting against the surface of the block (641); A T-shaped slider (643) movably connected to the U-shaped frame (632) is fixed at the bottom of the block (641), and the T-shaped slider (643) is used to improve the stability of the block (641) during horizontal movement; The moving distance of the block (641) is greater than the depth of the insertion block (642) inserted into the groove of the connecting block (633), thereby ensuring that the insertion block (642) can be completely disengaged from the groove of the connecting block (633).

2. A lithium battery welding device according to claim 1, characterized in that: The detection assembly (7) also includes an audible and visual alarm (74) fixed on the pressure plate (61); a rotating shaft (75) is fixed inside the U-shaped frame (632); a bent rod (71) is rotatably connected to the U-shaped frame (632) via the rotating shaft (75); a curved end of the bent rod (71) is movably connected to a side plate of the connecting block (633); and a tension spring (72) connected to the inner wall of the pressure plate (61) is fixed to the top of the bent rod (71).

3. A lithium battery welding device according to claim 2, characterized in that: The rotating shaft (75) is located at one third of the curved surface end of the bent rod (71).

4. A lithium battery welding method, the method using a lithium battery welding device according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: placing the lithium battery pack (3) on the positioning base (1), and placing the connecting piece (8) on the electrode of the lithium battery pack (3); Step 2: The lithium battery pack (3) is driven to move to the bottom of the three-axis motion guide rail (4) by the positioning base (1), and the lithium battery pack (3) is positioned by the positioning base (1); Step 3: Start the three-axis motion guide rail (4), and the three-axis motion guide rail (4) drives the laser welding head (5) to move to the top of the connecting piece (8); Step 4: The three-axis motion guide rail (4) triggers the flattening component (63) to flatten the connecting piece (8), and the detection component (7) detects whether the connecting piece (8) is flattened; Step 5: When the detection component (7) detects that the connecting piece (8) has been flattened, the laser welding head (5) is started to weld the connecting piece (8) and the electrode of the lithium battery pack (3); when the detection component (7) detects that the connecting piece (8) has not been flattened, step 4 is repeated until the connecting piece (8) is flattened; Step 6: The three-axis motion guide rail (4) drives the flattening mechanism (6) to move upward, and the positioning base (1) releases the positioning of the lithium battery pack (3). The positioning base (1) drives the lithium battery pack (3) to move rightward out of the outer cover (2), and the lithium battery pack (3) is removed.

5. A lithium battery welding method according to claim 4, characterized in that: The three-axis motion guide rail (4) triggers the first contact sensor (62) when moving downward, and the flattening component (63) is started through the first contact sensor (62).

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