Vacuumizing air pressure type lithium battery liquid injection mechanism

Abstract

The invention relates to the technical field of lithium battery liquid injection, and particularly discloses a vacuumizing air pressure type lithium battery liquid injection mechanism which comprises a rack, a liquid injection system, a vacuum system, a lithium battery conveying system and a control system, the liquid injection system comprises a buffer cup arranged on the rack in a reciprocating motion mode, the buffer cup is provided with a containing cavity for containing electrolyte and a liquid injection needle communicated with the containing cavity, and the lithium battery conveying system is used for conveying an external lithium battery to the liquid injection system to be used in cooperation with the buffer cup; the liquid injection system comprises a first pipe body communicated to the containing cavity and an electrolyte storage tank communicated with the first pipe body, the vacuum system comprises a second pipe body arranged in the buffer cup in a reciprocating motion mode and a vacuum pump communicated with the second pipe body, and the second pipe body is coaxially aligned with a liquid injection hole of the lithium battery through a liquid injection needle; the vacuum pump forms a vacuum cavity in the lithium battery through the second pipe body; the vacuum pump is in electric signal connection with the control system, and the control system is used for controlling the vacuum pump to vacuumize the liquid injection cavity before liquid injection and to be closed after liquid injection is completed.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery liquid injection, and in particular discloses a vacuum pneumatic lithium battery liquid injection mechanism. Background Art

[0002] In the manufacturing process of lithium batteries, liquid injection is one of the key processes, and its quality directly affects battery performance and safety. Traditional liquid injection mechanisms mostly use open liquid injection methods, and the electrolyte is easy to volatilize or leak, resulting in unstable liquid injection volume (the error is usually more than ±5%). Existing vacuum liquid injection equipment is difficult to form a stable high vacuum environment (usually below -80kPa) inside the lithium battery, resulting in uneven electrolyte penetration; liquid injection, wiping, and refilling processes mostly rely on manual operations, with low efficiency and poor consistency; there is a lack of a reliable sealing structure between the liquid injection needle and the liquid injection hole, which is easy to cause electrolyte overflow or contamination. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a vacuum pneumatic lithium battery injection mechanism to solve the above technical problems.

[0004] To achieve the above-mentioned purpose, the present invention provides a vacuum pneumatic lithium battery injection mechanism, comprising a frame, an injection system, a vacuum system, a lithium battery conveying system and a control system; the injection system comprises a buffer cup reciprocatingly arranged on the frame, the buffer cup having a receiving chamber for receiving electrolyte and an injection needle connected to the receiving chamber, and the lithium battery conveying system is used to convey external lithium batteries to the injection system for use in conjunction with the buffer cup;

[0005] The liquid injection system includes a first tube body connected to the accommodating cavity of the buffer cup and an electrolyte storage tank connected to the first tube body, the vacuum system includes a second tube body reciprocatingly arranged in the buffer cup and a vacuum pump connected to the second tube body, the second tube body is coaxially aligned with the liquid injection hole of the lithium battery via the liquid injection needle, and the vacuum pump forms a vacuum chamber inside the lithium battery through the second tube body;

[0006] The vacuum pump is connected to the control system by electrical signals, and the control system is used to control the vacuum pump to evacuate the injection cavity before injection and to shut down after injection is completed.

[0007] Furthermore, the liquid injection system also includes a protective component, and a liquid inlet is provided at one end of the cache cup away from the lithium battery. The protective component includes a first plate body arranged on a frame, a protective ring arranged on an outer wall of the cache cup, a first elastic member arranged between the protective ring and the first plate body, and a first driving member for driving the protective ring to reciprocate relative to the cache cup. In a non-liquid injection state, the protective ring covers the liquid inlet. During liquid injection, the first driving member drives the protective ring to move to expose the liquid inlet. The protective component also includes a second driving member connected to the first tube body. When the liquid inlet is exposed, the second driving member drives the first tube body to enter the liquid inlet for liquid injection.

[0008] Furthermore, the output end of the vacuum pump has a vacuum suction nozzle, and the vacuum system also includes a third driving component connected to the vacuum suction nozzle, and the third driving component is used to drive the vacuum suction nozzle to cooperate with the second tube body in a coaxial seal so that the vacuum pump can vacuum the inner cavity of the lithium battery.

[0009] Furthermore, the lithium battery conveying system includes a fourth driving member arranged on the frame, and a carrying rack reciprocatingly arranged on the frame for accommodating external lithium batteries. The fourth driving member is connected to the carrying rack and is used to drive the carrying rack to reciprocate relative to the injection system. The moving direction of the carrying rack and the moving direction of the cache cup are arranged to cross each other.

[0010] Furthermore, a sealing gasket is provided at one end of the injection needle close to the injection hole, and the injection needle is fastened to the injection hole via the sealing gasket. The injection system also includes an injection drive plate, a fourth drive member connected to the injection drive plate, a fastening ring arranged at the bottom of the buffer cup, and a second elastic member arranged between the fastening ring and the injection drive plate. The fourth drive member is used to drive the injection drive plate to reciprocate, and the injection drive plate is linked to the cache cup via the second elastic member and the fastening ring to allow the injection needle to be elastically inserted into the injection hole of the lithium battery.

[0011] Furthermore, the liquid injection system is provided with multiple groups, and the multiple groups of liquid injection systems are arranged at intervals along the length direction of the frame. The supporting material rack is provided with multiple partitions, and the multiple partitions divide the internal space of the supporting material rack into multiple temporary storage chambers for storing external lithium batteries. The number of the temporary storage chambers is consistent with the number of cache cups of the liquid injection system.

[0012] Furthermore, the first driving member and the second driving member are both cylinders driven by compressed air, and the input ends of the first driving member and the second driving member are connected to the air compression assembly. The frame is also provided with a solenoid valve, and the first driving member and the second driving member are connected to the control system via the solenoid valve via electrical signals. The control system regulates the flow direction of the compressed air generated by the air compression assembly via the solenoid valve to sequentially link the first driving member and the second driving member to complete the lifting and lowering of the protective ring and the extension and retraction of the first tube body.

[0013] Furthermore, a pressure sensor is provided on the inner wall of the second tube body, and the pressure sensor is electrically connected to the control system for real-time monitoring of the vacuum degree of the inner cavity of the lithium battery and feeding back to the control system. The control system dynamically adjusts the operating power of the vacuum pump according to the vacuum degree signal of the inner cavity of the lithium battery fed back by the pressure sensor.

[0014] Furthermore, a limit block is provided in the accommodating cavity of the cache cup, a stop ring is provided at one end of the second tube body close to the limit block, a limit cylinder connected to the accommodating cavity of the cache cup is installed on the limit block, the second tube body is penetrated into the limit cylinder, the limit block and the accommodating cavity of the cache cup, a third elastic member is provided between the stop ring and the limit block, the third driving member drives the vacuum suction nozzle to reciprocate and cooperate with the coaxial seal of the second tube body, and the second tube body reciprocates relative to the cache cup with the help of the action force of the third driving member and the elastic action force of the third elastic member.

[0015] Furthermore, the injection system also includes an injection pump and an injection valve, the injection valve is connected to the control system via an electrical signal, the injection valve is connected between the electrolyte storage tank and the first tube body, the injection valve has an inlet, an outlet and an exhaust port, the inlet is connected to the electrolyte storage tank via the injection pump, the outlet is connected to the first tube body via a pipeline, and the control system adjusts the flow rate of the electrolyte output by the injection pump to the first tube body via the injection valve.

[0016] Furthermore, a sealing ring is provided on the outer wall of the vacuum nozzle, a spiral air guide groove is provided on the outer wall of the sealing ring, and the outer diameter of the sealing ring is larger than the inner diameter of the second tube body and smaller than the outer diameter of the second tube body.

[0017] Furthermore, the lithium battery filling mechanism also includes a filling hole wiping system, which includes a wiping assembly, a positioning sensing device and a fifth driving member arranged on a frame for driving the wiping assembly to move back and forth; the wiping assembly, the fifth driving member and the positioning sensing device are all connected to the control system by electrical signals, the positioning sensing device is used to detect the position of the filling hole of the lithium battery after the filling operation, and the control system is used to control the wiping unit to spray the wiping medium onto the surface of the filling hole and control the fifth driving member to drive the wiping unit to perform a wiping operation on the filling hole.

[0018] Furthermore, the lithium battery filling mechanism also includes an automatic filling system, which includes a transmission track arranged on a frame, a loading frame slidably arranged on the transmission track, a weighing assembly arranged at the bottom of the transmission track, and a filling assembly used in conjunction with the loading frame. The loading frame is used to transfer the lithium battery processed by the filling system to the weighing assembly, and the weighing assembly detects the weight data of the lithium battery after filling and uploads it to the control system. The control system determines whether the injection amount meets the standard based on the preset weight ratio of the lithium battery after filling. If not, the loading frame picks up the lithium battery to the filling assembly, and the control system regulates the filling assembly to fill the lithium battery that does not meet the standard.

[0019] The vacuum pneumatic lithium battery injection mechanism realizes efficient injection of lithium batteries through the coordinated work of the injection system, vacuum system, lithium battery conveying system and control system. The buffer cup in the injection system contains electrolyte and is connected to the injection hole of the lithium battery through the injection needle. The vacuum system uses a vacuum pump to form a vacuum chamber inside the lithium battery so as to evacuate the vacuum before injection to improve the wettability of the electrolyte. During injection, the control system controls the injection valve to open, and the electrolyte is transported from the electrolyte storage tank to the buffer cup through the injection pump and injected into the lithium battery through the injection needle. After the injection is completed, the vacuum pump is turned off, the injection valve is closed, and the injection process is completed. The protective component covers the liquid inlet when it is not injected. During injection, the first driving member drives the protective ring to move to expose the liquid inlet, and then the second driving member drives the first tube body liquid inlet to start injection, ensuring the safety and sealing of the injection process. The lithium battery conveying system accurately transports the lithium battery to the injection position through the carrying rack and the fourth driving member, and is used in conjunction with the injection system. The filling hole wiping system wipes the filling hole after the filling is completed to ensure the cleanliness of the filling hole. The automatic filling system fills the lithium battery with liquid that does not meet the filling volume standard to ensure the accuracy of the filling volume.

[0020] The beneficial effects of the present invention are as follows: the interior of the lithium battery is evacuated by the vacuum system before liquid injection, thereby improving the wettability of the electrolyte, ensuring that the electrolyte fully infiltrates the positive and negative electrode materials and the diaphragm inside the battery cell, and improving the battery performance and capacity; the protective component in the liquid injection system covers the liquid inlet when not injected, preventing electrolyte leakage and external impurities from entering, thereby ensuring the safety and sealing of the liquid injection process; through the high-precision weighing component and the micro-liquid replenishment pump, the injection amount error is controlled within ±0.5%, significantly improving the battery consistency; the fully automated design shortens the single injection cycle to less than 30 seconds, and the production efficiency is increased by more than 40%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the liquid injection mechanism of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the lithium battery delivery system of the present invention;

[0023] Figure 3 It is a partial structural schematic diagram of the protection component of the present invention;

[0024] Figure 4 It is a partial structural schematic diagram of the liquid injection mechanism of the present invention;

[0025] Figure 5 It is a structural schematic diagram of the vacuum system of the present invention;

[0026] Figure 6 It is a schematic diagram of the structure of the buffer cup of the present invention;

[0027] Figure 7 It is a schematic cross-sectional structural diagram of the buffer cup of the present invention;

[0028] Figure 8 It is a structural schematic diagram of the fluid infusion system of the present invention;

[0029] Fig. 9 It is a structural schematic diagram of the liquid injection hole wiping system of the present invention.

[0030] Reference numerals include:

[0031] 1. Frame; 2. Liquid injection system; 3. Vacuum system; 4. Lithium battery conveying system; 5. Control system; 6. Liquid injection hole wiping system; 7. Liquid replenishing system; 61. Wiping assembly; 611. Nozzle cylinder; 612. Cleaning nozzle; 613. Rotating cylinder; 614. Wiping head; 62. Positioning sensing device; 63. Sixth driving member; 71. Transmission track; 72. Loading frame; 73. Weighing assembly; 74. Liquid replenishing assembly; 21. Buffer cup; 201. Liquid injection pump; 202. Liquid injection valve; 210. Liquid inlet; 211. Accommodating chamber; 212. Liquid injection needle; 213. Sealing pad; 214. Limit block; 215. Limit cylinder ; 216, third elastic member; 220, driving side plate; 22, first tube body; 23, electrolyte storage tank; 24, protective assembly; 241, first plate body; 242, protective ring; 243, first elastic member; 244, first driving member; 245, second driving member; 25, fifth driving member; 26, liquid injection driving plate; 27, fastening ring; 28, second elastic member; 29, solenoid valve; 31, second tube body; 311, stop ring; 32, vacuum pump; 321, vacuum nozzle; 3211, sealing ring; 322, third driving member; 41, fourth driving member; 42, material carrier; 421, partition; 422, temporary storage chamber. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0033] See also Figures 1 to 9 As shown, a vacuum pneumatic lithium battery injection mechanism of the present invention comprises a frame 1, an injection system 2, a vacuum system 3, a lithium battery conveying system 4 and a control system 5; the injection system 2 comprises a buffer cup 21 arranged on the frame 1 for reciprocating movement through the injection driving plate 26 and the fourth driving member 41, the buffer cup 21 has a receiving cavity 211 for receiving electrolyte, and an injection needle 212 connected to the receiving cavity 211 is arranged at the bottom of the buffer cup 21, and the lithium battery conveying system 4 is used to convey external lithium batteries to the injection system 2 for use with the buffer cup 21; the lithium battery conveying system 4 drives the carrying material rack 42 to reciprocate by a combination of a cylinder and a slide rail slider, and its moving direction is perpendicular to the moving direction of the injection driving plate 26. The lithium battery conveying system 4 is equipped with a laser positioning sensor and a material picking manipulator, the material picking manipulator is used to pick up the lithium battery of the previous step to the carrying material rack 42, and the laser positioning sensor is used to detect whether the injection needle 212 and the injection hole are accurately aligned.

[0034] The injection system 2 includes a first tube body 22 connected to the accommodating chamber 211 of the cache cup 21 and an electrolyte storage tank 23 connected to the first tube body 22. The vacuum system 3 includes a second tube body 31 reciprocatingly arranged in the cache cup 21 and a vacuum pump 32 connected to the second tube body 31. The second tube body 31 is coaxially aligned with the injection hole of the lithium battery via the injection needle 212, and the vacuum pump 32 forms a vacuum chamber inside the lithium battery through the second tube body 31; the first tube body 22 is detachably mounted on a driving side plate 220 obliquely disposed on one side of the frame 1, and the driving side plate 220 is driven by a sixth driving member 63 (pneumatic, that is, the middle part of the driving side plate 220 is connected to the piston rod of a cylinder, and the two sides of the driving side plate 220 are slidably connected to the frame 1 through guide rods).

[0035] The vacuum pump 32 is connected to the control system 5 by electrical signals. The control system 5 is used to control the vacuum pump 32 to evacuate the injection cavity before injection and to shut down after injection.

[0036] The control system 5 is configured to control according to the following timing:

[0037] a) driving the material carrier 42 and the lithium batteries thereon to move to the liquid filling station, i.e., below the buffer cup 21;

[0038] b) driving the buffer cup 21 to move downward so that the injection needle 212 is inserted into the lithium battery injection hole;

[0039] c) controlling the vacuum nozzle 321 to move the second tube body 31 downward and seal the liquid injection hole;

[0040] d) Start the vacuum pump 32 to evacuate to -90 kPa;

[0041] e) driving the protective ring 242 to move downward to expose the liquid inlet 210, and then driving the first tube 22 to be inserted into the liquid injection hole;

[0042] f) controlling the injection pump 201 and the injection valve 202 to open and pressurize the electrolyte in the electrolyte storage tank 23 to inject into the buffer cup 21, and then inject into the inner cavity of the lithium battery through the injection needle 212;

[0043] g) After the injection is completed, turn off the vacuum pump 32 and reset all components.

[0044] Specifically, the injection system 2 also includes a protective component 24, and a liquid inlet 210 is provided at one end of the cache cup 21 away from the lithium battery. The protective component 24 includes a first plate body 241 arranged on the frame 1 (in this embodiment, the first plate body 241 is arranged on the injection drive plate 26), a protective ring 242 arranged on the outer wall of the cache cup 21, a first elastic member 243 arranged between the protective ring 242 and the first plate body 241, and a first driving member 244 for driving the protective ring 242 to reciprocate relative to the cache cup 21.

[0045] The cylinder body of the first driving member 244 is fixed on the frame 1, and its piston rod is connected to the protective ring 242 through a connecting plate. When no liquid is injected, the protective ring 242 covers the liquid inlet 210. When injecting liquid, the first driving member 244 drives the protective ring 242 to move to expose the liquid inlet 210. The protective assembly 24 also includes a second driving member 245 connected to the first tube body 22. When the liquid inlet 210 is exposed, the second driving member 245 drives the first tube body 22 to enter the liquid inlet 210 for injection. The inner wall of the liquid inlet 210 is provided with a conical sealing surface.

[0046] Specifically, the output end of the vacuum pump 32 has a vacuum suction nozzle 321, and the vacuum system 3 also includes a third driving member 322 connected to the vacuum suction nozzle 321, and the third driving member 322 is used to drive the vacuum suction nozzle 321 to coaxially seal with the second tube body 31 so that the vacuum pump 32 can vacuum the inner cavity of the lithium battery.

[0047] Specifically, a sealing ring 3211 is disposed on the outer wall of the vacuum nozzle 321 , and a spiral air guide groove is disposed on the outer wall of the sealing ring 3211 . The outer diameter of the sealing ring 3211 is larger than the inner diameter of the second tube body 31 and smaller than the outer diameter of the second tube body 31 .

[0048] Specifically, the lithium battery conveying system 4 includes a fourth driving member 41 arranged on the frame 1, and a carrying rack 42 for accommodating external lithium batteries, which is reciprocated by a slide rail slider and is arranged on the frame 1. A plurality of aluminum alloy partitions 421 with adjustable spacing are arranged in the carrying rack 42, which are fixed in the carrying rack 42 by bolts to divide the internal space of the carrying rack 42 into a plurality of temporary storage chambers 422. The fourth driving member 41 is connected to the carrying rack 42 to drive the carrying rack 42 to reciprocate relative to the injection system 2. The moving direction of the carrying rack 42 and the moving direction of the cache cup 21 are arranged to intersect with each other, and an infrared alignment sensor is arranged between the carrying rack 42 and the cache cup 21.

[0049] Specifically, a sealing gasket 213 made of silicone is provided at one end of the injection needle 212 close to the injection hole, and the injection needle 212 is fastened to the injection hole via the sealing gasket 213. The injection system 2 also includes an injection drive plate 26, a fourth drive member 41 connected to the injection drive plate 26, a fastening ring 27 arranged at the bottom of the buffer cup 21, and a second elastic member 28 arranged between the fastening ring 27 and the injection drive plate 26; both sides of the injection drive plate 26 are slidably connected to the frame 1 through guide columns, and the fourth drive member 41 is used to drive the injection drive plate 26 to move up and down, and the injection drive plate 26 is linked to the buffer cup 21 via the second elastic member 28 and the fastening ring 27 so that the injection needle 212 is elastically inserted into the injection hole of the lithium battery.

[0050] Specifically, the injection system 2 is provided with 6 groups, and the 6 groups of injection systems 2 are arranged in parallel along the length direction of the frame 1 with a spacing of 10-15 mm. The number of the temporary storage chambers 422, the number of the cache cups 21 of the injection system 2, the number of the first tube bodies 22, and the number of the second tube bodies 31 are all kept consistent. The 6 first tube bodies 22 can be detachably mounted on the driving side plate 220 and synchronously driven by the second driving member 245.

[0051] Specifically, the first driving member 244 , the second driving member 245 , the third driving member 322 , the fourth driving member 41 , the fifth driving member 25 and the sixth driving member 63 in this embodiment are all cylinders, and are all connected to the control system 5 through a three-position five-way solenoid valve 29 .

[0052] Specifically, a pressure sensor is provided on the inner wall of the second tube body 31, and the pressure sensor is electrically connected to the control system 5 for real-time monitoring of the vacuum degree of the inner cavity of the lithium battery and feeding back to the control system 5. The control system 5 dynamically adjusts the operating power of the vacuum pump 32 according to the vacuum degree signal of the inner cavity of the lithium battery fed back by the pressure sensor.

[0053] The control system 5 is configured as follows: when the vacuum degree of the lithium battery cavity does not reach -80 kPa, the power of the vacuum pump 32 is increased to 120% of the rated power; when the vacuum degree exceeds -95 kPa, the overpressure protection is triggered and the vacuum pump 32 is turned off.

[0054] Specifically, a limit block 214 is provided in the accommodating cavity 211 of the cache cup 21, a stop ring 311 is provided at one end of the second tube body 31 close to the limit block 214, a limit cylinder 215 connected to the accommodating cavity 211 of the cache cup 21 is installed on the limit block 214, the second tube body 31 is passed through the limit cylinder 215, the limit block 214 and the accommodating cavity 211 of the cache cup 21, a third elastic member 216 is provided between the stop ring 311 and the limit block 214, the third driving member 322 drives the vacuum suction nozzle 321 to reciprocate and coaxially seal with the second tube body 31, and the second tube body 31 reciprocates relative to the cache cup 21 with the help of the action force of the third driving member 322 and the elastic action force of the third elastic member 216. In this embodiment, the first elastic member 243, the second elastic member 28, and the third elastic member 216 are all helical compression springs.

[0055] Specifically, a bubble detection sensor connected to the control system 5 by electrical signals is provided in the injection needle 212 for detecting bubbles in the electrolyte. The control system 5 is configured to suspend injection and start the exhaust procedure when bubbles are detected.

[0056] Specifically, a magnetic sealing ring is provided on the outer wall of the vacuum nozzle 321, and an electromagnet is embedded on the inner wall of the second tube body 31. When the vacuum nozzle 321 is inserted into the second tube body 31, the electromagnet is energized to generate magnetic attraction, thereby enhancing the sealing effect.

[0057] Specifically, the injection system 2 also includes an injection pump 201 and an injection valve 202, the injection valve 202 is electrically connected to the control system 5, the injection valve 202 is connected between the electrolyte storage tank 23 and the first tube body 22, the injection valve 202 has an inlet 210, an outlet and an exhaust port, the inlet 210 is connected to the electrolyte storage tank 23 via the injection pump 201, and the outlet is connected to the first tube body 22 via a pipeline, and the control system 5 adjusts the flow rate of the electrolyte output by the injection pump 201 to the first tube body 22 via the injection valve 202.

[0058] Specifically, the lithium battery injection mechanism also includes an injection hole wiping system 6, which includes a wiping assembly 61 arranged on the frame 1, a positioning sensing device 62, and a sixth driving member 63 for driving the wiping assembly 61 to move back and forth (the sixth driving member 63 is a combination of a lifting motor and a screw module); the wiping assembly 61 includes a cleaning nozzle 612, which is driven by a nozzle cylinder 611, and its nozzle water inlet is connected to an ethanol spray unit and is arranged on the side of the ultrasonic cleaning head; an industrial camera (not shown in the figure) is used to detect the cleanliness of the injection hole; the control system 5 adjusts the cleaning parameters according to the feedback data of the industrial camera. The wiping assembly 61 also includes a rotating cylinder 613 and a wiping head 614 arranged below the rotating cylinder 613, and the positioning sensing device 62 is arranged on the wiping head 614.

[0059] Specifically, the lithium battery injection mechanism also includes an automatic refilling system 7, which includes a transmission track 71 arranged on the frame 1, a loading frame 72 slidably arranged on the transmission track 71, a weighing component 73 arranged at the bottom of the transmission track 71, and a refilling component 74 used in conjunction with the loading frame 72. The refilling component 74 has a micro-injection pump, which is driven by a mechanical arm to align with the injection hole; the control system 5 is configured to: if insufficient injection volume is detected, control the injection pump to refill at a rate of 0.1 mL / second.

[0060] The following is a further detailed description of the liquid injection mechanism of the present invention in combination with the technical solution of the present invention:

[0061] As shown in the figure, the injection system 2 includes:

[0062] The buffer cup 21 is lifted and lowered vertically along the frame 1 by the injection driving plate 26 and the fourth driving member 41. The volume of the internal accommodating chamber 211 is 950 ml. The bottom of the buffer cup 21 is provided with an injection needle 212, and a silicone sealing pad 213 is embedded at the end of the injection needle 212.

[0063] First tube body 22: one end is connected to the liquid inlet 210 of the buffer cup 21 through a quick-release joint, and the other end is connected to the electrolyte storage tank 23 through a three-way valve;

[0064] The protection assembly 24 includes a protection ring 242 sleeved on the outer wall of the buffer cup 21 . The protection ring 242 is elastically matched with the first plate 241 through a compression spring, and is driven to rise and fall by the first driving member 244 .

[0065] The vacuum system 3 includes:

[0066] The vacuum nozzle 321 has a pressure sensor embedded in its inner wall and a fluororubber sealing ring 3211 on its outer wall, the outer diameter of the ring being Φ1.2 mm (fitting a Φ1 mm injection hole);

[0067] The second tube body 31 has a sealing gasket 213 at the bottom thereof, which is used for sealingly cooperating with the inner wall of the buffer cup 21;

[0068] The third driving member 322 (cylinder) drives the vacuum nozzle 321 to insert into the second tube body 31 and is linked with the control system 5 .

[0069] The lithium battery delivery system 4 includes:

[0070] The material carrier 42 is horizontally moved along the frame 1 by the fourth driving member 41, and is provided with partitions 421 with adjustable spacing inside to form six temporary storage chambers 422;

[0071] Laser alignment sensor: real-time detection of the position deviation between the buffer cup 21 and the lithium battery, with an accuracy of ±0.1mm.

[0072] The control system 5 integrates a dynamic power regulation module: the power of the vacuum pump 32 is regulated according to the following formula based on the data of the pressure sensor:

[0073] P=P0×(1+20|ΔP|); wherein P0 is the rated power and ΔP is the vacuum deviation value (kPa); the control system 5 also integrates a closed-loop control module for the injection volume: the weight of the lithium battery after injection is detected by the weighing component 73, and if the deviation exceeds ±0.5%, the refilling procedure is started.

[0074] The workflow of the present invention is:

[0075] The fourth driving member 41 drives the lithium battery on the carrying rack 42 to be transferred to the injection station, and the laser alignment sensor corrects the position deviation to ensure that the injection needle 212 is coaxial with the injection hole;

[0076] The fifth driving member 25 drives the buffer cup 21 to press down so that the injection needle 212 is inserted into the injection hole;

[0077] When not filled with liquid, the protective ring 242 covers the liquid inlet 210 to prevent the electrolyte from volatilizing;

[0078] When injecting liquid, the first driving member 244 pulls down the protective ring 242, and the second driving member 245 drives the first tube body 22 to insert into the liquid inlet 210;

[0079] The third driving member 322 pushes the vacuum nozzle 321 to seal coaxially with the second tube body 31 and presses downward so that the second tube body 31 is connected to the injection hole;

[0080] The vacuum pump 32 is started to quickly evacuate to -90 kPa;

[0081] The pressure sensor feeds back data in real time, and the control system 5 dynamically adjusts the power of the vacuum pump 32;

[0082] After the vacuuming is completed, the three-way valve is opened, and the electrolyte is injected into the lithium battery through the injection needle 212 of the buffer cup 21;

[0083] After the liquid injection is completed, the sixth driving member 63 drives the wiping assembly 61 to ultrasonically clean the liquid injection hole; before ultrasonic cleaning, the control system 5 adjusts the automatic liquid replenishing system 7 to replenish the lithium batteries whose liquid injection does not meet the standard.

[0084] After ultrasonic cleaning, the lithium battery enters the next process.

[0085] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The content of this specification should not be understood as limiting the present invention.

Claims

1. A vacuum pneumatic lithium battery injection mechanism, characterized in that: The invention comprises a frame (1), a liquid injection system (2), a vacuum system (3), a lithium battery conveying system (4) and a control system (5); the liquid injection system (2) comprises a buffer cup (21) arranged on the frame (1) for reciprocating movement, the buffer cup (21) having a receiving chamber (211) for receiving electrolyte and a liquid injection needle (212) connected to the receiving chamber (211); the lithium battery conveying system (4) is used to convey external lithium batteries to the liquid injection system (2) for use in conjunction with the buffer cup (21); The injection system (2) further comprises a first tube body (22) connected to the accommodating chamber (211) and an electrolyte storage tank (23) connected to the first tube body (22); the vacuum system (3) comprises a second tube body (31) reciprocatingly arranged in the buffer cup (21) and a vacuum pump (32) connected to the second tube body (31); the second tube body (31) is coaxially aligned with the injection hole of the lithium battery via the injection needle (212); and the vacuum pump (32) forms a vacuum chamber inside the lithium battery via the second tube body (31); The vacuum pump (32) is connected to the control system (5) via an electrical signal, and the control system (5) is used to control the vacuum pump (32) to evacuate the inner cavity of the lithium battery before liquid injection and to shut down after liquid injection is completed.

2. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: The liquid injection system (2) further comprises a protection component (24); an end of the buffer cup (21) away from the lithium battery is provided with a liquid inlet (210); the protection component (24) comprises a first plate (241) arranged on the frame (1), a protection ring (242) sleeved on the outer wall of the buffer cup (21), a first elastic member (243) arranged between the protection ring (242) and the first plate (241), and a spring for driving the protection ring (242) to move relative to the buffer cup (21). The protective assembly (24) further comprises a first driving member (244) that is movable; when liquid is not injected, the protective ring (242) covers the liquid inlet (210); when liquid is injected, the first driving member (244) drives the protective ring (242) to move to expose the liquid inlet (210); the protective assembly (24) further comprises a second driving member (245) connected to the first tube body (22); when the liquid inlet (210) is exposed, the second driving member (245) drives the first tube body (22) to enter the liquid inlet (210) to inject liquid.

3. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: The output end of the vacuum pump (32) is provided with a vacuum suction nozzle (321), and the vacuum system (3) further comprises a third driving member (322) connected to the vacuum suction nozzle (321), the third driving member (322) being used to drive the vacuum suction nozzle (321) to coaxially seal with the second tube body (31) so that the vacuum pump (32) performs a vacuum process on the inner cavity of the lithium battery.

4. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: The lithium battery conveying system (4) comprises a fourth driving member (41) arranged on the frame (1), and a carrying rack (42) arranged on the frame (1) for accommodating external lithium batteries and reciprocatingly moving. The fourth driving member (41) is connected to the carrying rack (42) and is used to drive the carrying rack (42) to reciprocate relative to the buffer cup (21). The moving direction of the carrying rack (42) and the moving direction of the buffer cup (21) are arranged to intersect with each other.

5. The vacuum pneumatic lithium battery injection mechanism according to claim 4, characterized in that: The liquid injection system (2) is provided with a plurality of groups, and the plurality of liquid injection systems (2) are arranged at intervals along the length direction of the frame (1); a plurality of partitions (421) are provided inside the material carrier (42); the plurality of partitions (421) divide the internal space of the material carrier (42) into a plurality of temporary storage chambers (422) for storing external lithium batteries; the number of the temporary storage chambers (422) is consistent with the number of the buffer cups (21) of the liquid injection system (2).

6. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: A sealing gasket (213) is provided at one end of the injection needle (212) close to the injection hole, and the injection needle (212) is tightly matched with the injection hole via the sealing gasket (213). The injection system (2) also includes an injection drive plate (26), a fifth drive member (25) connected to the injection drive plate (26), a fastening ring (27) arranged at the bottom of the buffer cup (21), and a second elastic member (28) arranged between the fastening ring (27) and the injection drive plate (26). The fifth drive member (25) is used to drive the injection drive plate (26) to reciprocate, and the injection drive plate (26) is linked to the buffer cup (21) via the second elastic member (28) and the fastening ring (27) to move so that the injection needle (212) is elastically inserted into the injection hole of the lithium battery.

7. The vacuum pneumatic lithium battery injection mechanism according to claim 2, characterized in that: The first driving member (244) and the second driving member (245) are both cylinders driven by compressed air. The input ends of the first driving member (244) and the second driving member (245) are connected to air compression components. The injection system (2) also includes a solenoid valve (29). The first driving member (244) and the second driving member (245) are connected to the control system (5) via an electrical signal via the solenoid valve (29). The control system (5) controls the air compression component via the solenoid valve (29) to sequentially link the first driving member (244) and the second driving member (245) to complete the reciprocating movement of the protective ring (242) and the first tube body (22).

8. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: A pressure sensor is provided on the inner wall of the second tube body (31), and the pressure sensor is electrically connected to the control system (5) for real-time monitoring of the vacuum degree of the inner cavity of the lithium battery and feeding back to the control system (5). The control system (5) dynamically adjusts the operating power of the vacuum pump (32) according to the vacuum degree signal of the inner cavity of the lithium battery fed back by the pressure sensor.

9. The vacuum pneumatic lithium battery injection mechanism according to claim 3, characterized in that: A limit block (214) is provided in the receiving chamber (211) of the cache cup (21); a stop ring (311) is provided at one end of the second tube body (31) close to the limit block (214); a limit cylinder (215) connected to the receiving chamber (211) of the cache cup (21) is installed on the limit block (214); the second tube body (31) passes through the limit cylinder (215), the limit block (214) and the receiving chamber (211) of the cache cup (21); a third elastic member (216) is provided between the stop ring (311) and the limit block (214); the third driving member (322) drives the vacuum suction nozzle (321) to reciprocate and coaxially seal with the second tube body (31); the second tube body (31) reciprocates relative to the cache cup (21) with the help of the action force of the third driving member (322) and the elastic action force of the third elastic member (216).

10. The vacuum pneumatic lithium battery injection mechanism according to claim 1, characterized in that: The injection system (2) further comprises an injection pump (201) and an injection valve (202); the injection valve (202) is electrically connected to the control system (5); the injection valve (202) is connected between the electrolyte storage tank (23) and the first tube body (22); the liquid inlet (210) is connected to the electrolyte storage tank (23) via the injection pump (201); the liquid outlet of the injection valve (202) is connected to the first tube body (22) via an external pipeline; the control system (5) adjusts the flow rate of the electrolyte output by the injection pump (201) to the first tube body (22) via the injection valve (202).

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