An unmanned battery acid adding machine and acid adding method

Abstract

The invention discloses an unmanned acid adding machine and acid adding method for batteries, comprising a vacuuming part, an acid adding part, an acid storage part, and an acid adding pot connected to the battery; the acid adding part is connected to a lifting mechanism for driving, so that the acid adding part enters and seals the mouth of the acid adding pot after descending, and moves away from the mouth of the acid adding pot after ascending; the acid adding part is connected to the acid storage part through an acid inlet pipe with a valve, and a plurality of acid injection pipes with flush outlets are arranged on the acid adding part, and the acid injection pipes enter the acid adding pot after the acid adding part seals the mouth of the acid adding pot. The device completes vacuuming, acid injection, quantitative and acid adding processes simultaneously, thereby shortening the acid adding time.

Description

Technical Field

[0001] The invention relates to the field of battery manufacturing and processing, in particular to an unmanned battery acid adding machine and an acid adding method. Background Art

[0002] Lead-acid batteries are composed of a shell, positive and negative plates, separators, sulfuric acid electrolyte and terminal columns. Among them, sulfuric acid electrolyte acts as an inter-ion conductor and reactive substance during the charge and discharge process of lead-acid batteries. Studies have shown that key parameters such as the open circuit voltage, battery capacity, charge and discharge capacity, and cycle life of batteries are directly related to the concentration and amount of sulfuric acid electrolyte. It can be said that sulfuric acid is the "blood" of lead-acid batteries and plays a vital role in the performance of batteries.

[0003] In the traditional negative pressure acid adding process, the acid adding pot is manually fixed on the acid adding port of the battery, and then placed under the acid adding machine to carry out vacuuming, acid injection, and acid adding processes in sequence. Since the amount of acid injected is determined by the acid adding machine, and the air tightness of the acid adding pot and the acid adding machine accessories are different, the amount of acid added to each cell will be inconsistent, resulting in a series of problems such as poor charging consistency of each cell of the battery, insufficient capacity, local heating during use, and expansion and deformation. Traditional negative pressure acid adding generally requires multiple steps of acid injection, vacuuming, and acid adding. The operation process and pipelines are complicated. An operator can only add acid to two batteries at the same time, which is inefficient. In addition, during the existing acid adding process, the operator is exposed to sulfuric acid and acid mist for a long time, which can easily cause skin allergies, respiratory corrosion and other problems, posing great safety and environmental risks.

[0004] Chinese document CN201711153657 discloses a battery acid adding machine and acid adding method, which puts the battery group into a vacuum chamber for unified acid adding, reduces the sealing requirements of the acid adding pot group, and solves the problem of inconsistent acid adding amount in a single cell. However, the acid adding machine and the corresponding acid adding method disclosed in the patent have high requirements for the sealing of the vacuum chamber, and the number of acid adding batteries is limited by the volume of the vacuum chamber. At the same time, the acid adding process is cumbersome, and it is necessary to go through the steps of installing the acid adding pot group, placing the battery, vacuuming, adding acid, releasing the vacuum, and removing the battery. The production efficiency is not high, and it is difficult to achieve large-scale production. Summary of the invention

[0005] In view of this, it is necessary to provide an unmanned battery acid adding machine and acid adding method with consistent acid adding and high production efficiency.

[0006] In order to solve the above technical problems, a technical solution of the present invention is: an unmanned acid adding machine for batteries, comprising a vacuum pumping part, an acid adding part, an acid storage part, and an acid adding pot connected to the battery;

[0007] The acid adding part is connected to a lifting mechanism so that the acid adding part enters and seals the mouth of the acid adding pot after descending, and moves away from the mouth of the acid adding pot after ascending; the acid adding part is connected to the acid storage part through an acid inlet pipe with a valve, and a plurality of acid injection pipes with flush outlets are arranged on the acid adding part, and the acid injection pipes enter the acid adding pot after the acid adding part seals the mouth of the acid adding pot;

[0008] The vacuum pumping part is connected to the acid storage part through a reflux pipe with a valve. A plurality of negative pressure suction pipes with flush outlets are arranged on the vacuum pumping part. The negative pressure suction pipes enter into the acid adding pot after the acid adding part seals the mouth of the acid adding pot. The vacuum pumping part evacuates the acid adding part and the acid adding pot through the negative pressure suction pipes, and draws the acid liquid that does not pass through the outlet of the negative pressure suction pipes and transports it to the acid storage part through the reflux pipe, so that the liquid levels in the acid adding pots are the same.

[0009] Furthermore, the acid adding part is arranged above an assembly line, and the acid adding pot is arranged on the storage battery transported through the assembly line.

[0010] Furthermore, the acid adding part includes a vacuum chamber, an acid storage chamber and a sealing gasket for sealing the mouth of the acid adding pot. The acid injection tube passes through the sealing gasket and is connected to the acid storage chamber. The negative pressure suction tube passes through the sealing gasket and is connected to the vacuum chamber. After the acid adding part seals the mouth of the acid adding pot, there is at least one acid injection tube and at least one negative pressure suction tube in the acid adding pot.

[0011] Furthermore, the acid storage part includes an acid storage tank, and the acid inlet pipe connects the acid storage cavity and the acid storage tank.

[0012] Furthermore, the vacuum pumping part includes an acid return tank, which is connected to the vacuum pump through a vacuum pumping pipe with a valve, the reflux pipe connects the acid return tank and the acid storage tank, and the acid return tank is connected to the vacuum chamber through an acid return vacuum pipe.

[0013] Furthermore, the upper inlet of the acid injection tube is located at the upper part of the acid storage chamber, and the upper inlet of the negative pressure suction tube is located at the upper part of the vacuum chamber.

[0014] Furthermore, the bottom outlet of the acid return vacuum pipe is located at the bottom of the acid return tank, and the bottom inlet of the vacuum pipe is located at the upper part of the acid return tank.

[0015] Furthermore, the assembly line is a roller conveyor belt, and guide plates for guiding and limiting the batteries are arranged on both sides of the assembly line. The assembly line is also provided with limiting rods for stopping and fixing the batteries.

[0016] Furthermore, a bracket for fixing a lifting mechanism is provided on the assembly line, and the lifting mechanism is a cylinder. A guide column for guiding the lifting and lowering of the acid adding part is also provided on the bracket.

[0017] Furthermore, a negative pressure sensor is provided on the acid return vacuum tube.

[0018] In order to solve the above technical problems, another technical solution of the present invention is: a method for acid adding by an unmanned acid adding machine for batteries as described above, which is carried out according to the following steps:

[0019] S1: After the acid adding pot is installed on the battery, it is placed together on an assembly line, and after being transported to a predetermined position, it is stopped and fixed;

[0020] S2: driving the acid adding part to descend through the lifting mechanism and seal the mouth of the acid adding pot, so that at least one acid injection tube and at least one negative pressure suction tube enter the acid adding pot at the same time;

[0021] S3: Close the valves on the reflux pipe and the acid inlet pipe, and the vacuum pumping unit vacuumizes the acid adding unit, the acid adding pot and the battery through the negative pressure suction pipe;

[0022] S4: After the vacuum is completed, the valve on the acid inlet pipe is opened. Under the action of negative pressure, the acid in the acid storage part enters the acid adding part along the acid inlet pipe, and then is injected into the acid adding pot through the acid injection pipe, so that the acid level in the acid adding pot is higher than the bottom outlet of the negative pressure suction pipe;

[0023] S5: The vacuum pumping unit extracts the acid liquid in the acid adding pot that is higher than the bottom outlet of the negative pressure suction pipe, so that the liquid level in all acid adding pots is equal. After the acid addition is completed, the valve of the acid inlet pipe is closed, the vacuum pumping is stopped, and the valve on the reflux pipe is opened to allow the acid liquid in the vacuum pumping unit to flow back to the acid storage unit;

[0024] S6: The lifting mechanism drives the acid adding part to rise and leave the acid adding pot, and the assembly line transports the acid adding pot and the battery away, and then repeats the above steps.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Improve the consistency of acid addition in each cell of the lead-acid battery: vacuuming, acid injection, acid addition and quantitative addition are completed simultaneously. The amount of acid in each cell of the lead-acid battery is determined by the negative pressure pipette. The acid level in each cell of the battery pack is consistent, ensuring that the amount of acid added to each cell of the battery pack is consistent, thereby improving the charging consistency and life of the battery pack.

[0027] (2) Improve the service life of the acid dosing machine: The acid inlet pipe and the acid return vacuum pipe are fixed to the acid dosing mold, and there is no need for repeated connection, which avoids the difference in sealing caused by aging of the acid dosing machine, improves the equipment life and reduces costs.

[0028] (3) Improve production efficiency and realize large-scale acid addition: vacuuming, acid injection, acid addition and quantitative addition are completed simultaneously, effectively shortening the acid addition time; the acid addition pot adopts an open-top design, and the acid injection pipe and the negative pressure suction pipe do not need to be precisely aligned, which improves operating efficiency; the acid inlet pipe and the acid return vacuum pipe have simple structures, and multiple acid addition molds can be connected in parallel for continuous operation, realizing large-scale acid addition of batteries and improving process production efficiency;

[0029] (4) Realize unmanned automatic acid addition: Through the coordinated control of the limit device, sensor, solenoid valve and PLC, combined with the acid addition mold of the present invention, the acid addition process can be unmanned, reducing labor costs and safety hazards.

[0030] In order to make the above and other purposes, features and advantages of the present invention more clearly understood, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of the structure of the rack in the embodiment of the present invention.

[0033] Figure 3 It is a structural schematic diagram of the acid adding part, acid return tank, acid storage tank and pipeline in an embodiment of the present invention.

[0034] Figure 4 Schematic diagram of the structure of the acid adding unit in an embodiment of the present invention.

[0035] Figure 5 It is a structural schematic diagram of an acid adding kettle in an embodiment of the present invention.

[0036] In the figure: 1-frame, 11-roller conveyor, 12-guide plate, 13-limiting rod, 14-bracket, 15-cylinder, 16-guide column, 2-acid adding mold, 21-vacuum chamber, 22-negative pressure suction pipe, 23-gap, 24-acid storage chamber, 25-acid injection pipe, 26-sealing pad, 27-fixed plate, 3-acid return tank, 31-reflux pipe, 32-first solenoid valve, 4-acid storage tank, 5-acid inlet main pipe, 51-second solenoid valve, 52-acid inlet branch pipe, 53-third solenoid valve, 6-acid return vacuum pipe, 61-negative pressure sensor, 7-vacuum pipe, 71-fourth solenoid valve, 8-acid adding pot, 9-battery. DETAILED DESCRIPTION

[0037] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0038] like Figure 1 As shown, an unmanned battery acid adding machine includes a frame 1, an acid adding part, a vacuum pumping part, an acid storage part, an acid adding pot 8 and a battery 9.

[0039] like Figure 2As shown, a roller conveyor belt 11 is arranged on the frame 1, and guide plates 12 for guiding the battery 9 and limit rods 13 for stopping and fixing the battery 9 are arranged on both sides of the roller conveyor belt 11, respectively. A bracket 14 spanning the roller conveyor belt 11 is arranged on the frame 1, and a vertical cylinder 15 and a guide column 16 are arranged on the bracket.

[0040] like Figure 3 , 4 As shown, the acid adding part includes a fixed plate 27, a vacuum chamber 21, an acid storage chamber 24 and a sealing gasket 26 (made of acid-resistant rubber or silicone) arranged in sequence from top to bottom. The fixed plate 27 is connected to the piston rod of the cylinder 15 and the guide column 16. The vacuum chamber 21 is connected to a plurality of negative pressure suction pipes 22, which pass through the acid storage chamber 24 and the sealing gasket 26 in sequence. The acid storage chamber 24 is connected to a plurality of acid injection pipes 25, which pass through the sealing gasket 26, so that when the acid adding part is driven by the cylinder 15 to descend and enter and seal the mouth of the acid adding pot 8, an acid injection pipe and a negative pressure suction pipe enter the acid adding pot at the same time.

[0041] The acid storage part includes an acid storage tank 4, and an acid inlet main pipe 5 with a second solenoid valve 51 is arranged at the bottom of the acid storage tank 4. A plurality of acid inlet branch pipes 52 with a third solenoid valve 53 are connected to the acid inlet main pipe 5, and one of the acid inlet branch pipes 52 is connected to the acid storage chamber 24.

[0042] The vacuum pumping part includes an acid return tank 3, which is connected to the vacuum pump through a vacuum pumping pipe 7 with a fourth valve 71. The bottom of the acid return tank 3 is connected to the acid storage tank 4 through a reflux pipe 31 with a first valve 32. The acid return tank 3 is connected to the vacuum chamber 21 through an acid return vacuum pipe 6 with a negative pressure sensor 61.

[0043] In this embodiment, the bottom outlets of all negative pressure suction pipes 22 are flush with each other to ensure the consistency of the liquid level height in all acid adding pots; the bottom outlets of all acid injection pipes 25 are flush with each other to ensure the consistency of acid injection.

[0044] In this embodiment, the upper inlet of the acid injection pipe 25 is located at the upper part of the acid storage chamber 24, and the upper inlet of the negative pressure suction pipe 22 is located in the vacuum chamber 21. The pipe mouth is located at a high position to prevent the acid from entering the chamber due to back suction. When the upper inlet of the acid injection pipe 25 and the negative pressure suction pipe 22 are against the upper surface of the chamber, a notch 23 is provided on the side wall of the upper inlet of the acid injection pipe 25 and the negative pressure suction pipe 22.

[0045] In this embodiment, there may be multiple acid adding sections on the same roller conveyor belt 11 .

[0046] In this embodiment, Figure 5 As shown, the top of the acid adding pot 8 is an open opening, and the bottom is provided with acid injection holes corresponding to the acid adding holes of the battery 9; the acid adding pot 8 is made of hard plastic material.

[0047] In this embodiment, the acid injection tube 25 is a hard plastic tube; the negative pressure suction tube 22 is a hard plastic tube.

[0048] In this embodiment, the connecting section between the acid inlet branch pipe 52 and the acid storage chamber 24 is a hard metal pipe, and the rest is a soft plastic pipe; the connecting section between the acid return vacuum pipe 6 and the vacuum chamber 21 is a hard metal pipe, and the rest is a soft plastic pipe.

[0049] The above-mentioned battery acid adding method using an unmanned acid adding machine is carried out according to the following steps:

[0050] S1: After the acid adding pot is installed on the battery, it is placed together on an assembly line for transmission. When it reaches the bottom of the acid adding part, it is stopped and fixed after being restricted by the guide plate and the limit rod;

[0051] S2: The cylinder drives the acid adding part to descend and enter the mouth of the acid adding pot. The sealing gasket seals the mouth of the acid adding pot, so that an acid injection tube and a negative pressure suction tube enter the acid adding pot at the same time;

[0052] S3: Open the fourth solenoid valve on the vacuum pipe, close the first valve on the reflux pipe, the second valve on the acid inlet main pipe and the third valve on the acid inlet branch pipe, and start the vacuum pump to vacuum the vacuum chamber, the acid storage chamber, the acid adding pot and the battery through the negative pressure suction pipe;

[0053] S4: After the vacuum degree reaches the specified value, the second valve on the acid inlet main pipe and the third valve on the acid inlet branch pipe are opened. Under the action of negative pressure, the acid in the acid storage part enters the acid storage cavity along the acid inlet main pipe and the acid inlet branch pipe, and then is injected into the acid adding pot through the acid injection pipe, so that the acid level in the acid adding pot is higher than the bottom outlet of the negative pressure suction pipe;

[0054] S5: The vacuum pump extracts the acid liquid in the acid adding pot that is higher than the bottom outlet of the negative pressure suction pipe and sends it to the acid return tank to make the liquid level in all acid adding pots equal. After the acid addition is completed, the second valve on the acid inlet main pipe and the third valve on the acid inlet branch pipe are closed, the vacuum pumping is stopped, and the first valve on the reflux pipe is opened to make the acid liquid in the acid return tank flow back to the acid storage tank;

[0055] S6: The cylinder drives the acid adding part to rise and leave the acid adding pot, and the roller conveyor conveys the acid adding pot and the battery away, and then a new acid adding pot and the battery are moved to the bottom of the acid adding part, and the above steps are repeated.

[0056] Implementation case 1:

[0057] This implementation case is a method of quantitatively adding acid to 4 lead-acid batteries at the same time.

[0058] The bottom of the acid adding part used in this embodiment is provided with 24 acid injection tubes 25 and negative pressure suction tubes 22. The positions of the acid injection tubes 25 and negative pressure suction tubes 22 correspond to each single grid at the bottom of the acid adding pot 8, and one acid injection tube 25 and one negative pressure suction tube 22 will be inserted into the acid adding pot respectively.

[0059] After installing the open acid adding pot 8 and the battery 9 one by one, they are placed on the tray and then placed on the roller conveyor 11. They reach the bottom of the acid adding part through the guide plate 12 and the limit rod 13. The cylinder is started to push the acid adding part downward so that the sealing pad at the bottom of the acid adding part is tightly fitted and sealed with the top of the acid adding pot. The top of the acid adding pot is open, and the acid injection pipe and the negative pressure suction pipe at the bottom of the acid adding part can be inserted into each single cell of the acid adding pot one by one, without manual precise positioning. Open the fourth solenoid valve, start the vacuum pump, and the inside of the battery, the inner cavity of the acid adding pot, the vacuum cavity in the acid adding part, and the acid storage cavity are connected to form a negative pressure air chamber. When the vacuum degree reaches the specified value, open the second and third solenoid valves, and sulfuric acid is injected from the acid storage tank through the acid inlet main pipe, the acid inlet branch pipe, the acid storage cavity and the acid injection pipe into the inside of the acid adding pot and the battery single cell, and the excess acid is drawn away by the negative pressure suction pipe and enters the acid return tank. The negative pressure straws inserted into the acid adding pot have the same length, which can ensure that the acid levels inside the four batteries and the acid adding pot are at the same height. The battery shell and the acid adding pot are made of hard plastic, and the total internal volume is consistent, so that the acid injection amount of all cells can be determined to be consistent, achieving the purpose of quantitative acid addition. At this point, the battery pack is acid-added, and the vacuum pump is turned off to release the vacuum. The cylinder drives the acid adding part to rise, and the upper limit rod of the roller conveyor belt 11 is lifted, and the battery pack enters the next process with the assembly line. The first solenoid valve on the acid return pipe is opened, and the excess acid returns to the acid storage tank. All the above valves are controlled by solenoid valves, and no manual operation is required. The unmanned acid addition steps are cyclically carried out, which greatly improves the production efficiency of the acid addition process.

[0060] Implementation case 2:

[0061] This implementation case is an unmanned acid adding machine and acid adding method that can quantitatively add acid to 12 lead-acid batteries at the same time.

[0062] This implementation case uses three acid adding parts that are the same as those in the implementation case 1. Each group of acid adding parts is provided with 24 acid injection tubes and negative pressure suction tubes at the bottom. The acid tubes and negative pressure suction tubes are respectively connected to the acid storage chamber and vacuum chamber inside the acid adding part. The three acid adding parts are fixed side by side to form an acid adding part group, and the acid inlet branch pipes and acid return vacuum pipes of the three acid adding parts are respectively connected in parallel. The positions of the acid injection tubes and negative pressure suction tubes correspond one to one with each single grid at the bottom of the acid adding pot, and one sulfuric acid tube and one negative pressure suction tube will be inserted into the acid adding pot respectively. The acid injection process is the same as the above steps.

[0063] It can be seen from the above implementation cases that the device is easy to operate and the acid adding process can be fully automated. The vacuuming, acid injection, acid adding and quantitative steps are completed simultaneously, shortening the acid adding time and improving the process production efficiency. At the same time, multiple acid adding molds are used in parallel to realize matrix-type large-scale unmanned acid adding. A negative pressure suction pipe is provided in the acid adding part. By pumping away excess acid to achieve the quantitative amount of acid addition, the acid addition amount of all cells in the battery pack can be consistent, thereby improving product consistency; the acid inlet branch pipe and the acid return vacuum pipe of the acid adding part are fixed, and there is no need to repeatedly connect, which improves the sealing, reduces aging, and increases the service life of the acid adding machine; the acid adding pot adopts a top opening design, and the acid injection pipe and the negative pressure suction pipe do not need to be precisely aligned, which improves the operating efficiency; the acid inlet branch pipe and the acid return vacuum pipe have a simple structure and can be connected in parallel in multiple ways to realize large-scale batch acid adding and improve the process production efficiency; the assembly line with a limit device can realize unmanned automatic acid adding.

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An unmanned battery acid adding machine, characterized in that: It includes a vacuuming part, an acid adding part, an acid storage part, and an acid adding pot connected to a storage battery; The acid adding part is connected to a lifting mechanism so that the acid adding part enters and seals the mouth of the acid adding pot after descending, and moves away from the mouth of the acid adding pot after ascending; the acid adding part is connected to the acid storage part through an acid inlet pipe with a valve, and a plurality of acid injection pipes with flush outlets are arranged on the acid adding part, and the acid injection pipes enter the acid adding pot after the acid adding part seals the mouth of the acid adding pot; The vacuuming part is connected to the acid storage part through a reflux pipe with a valve, and a plurality of negative pressure suction pipes with flush outlets are arranged on the vacuuming part. The negative pressure suction pipes enter the acid adding pot after the acid adding part seals the pot mouth of the acid adding pot. The vacuuming part vacuumizes the acid adding part and the acid adding pot through the negative pressure suction pipes, and draws the acid liquid that does not pass through the outlet of the negative pressure suction pipes and transports it to the acid storage part through the reflux pipe, so that the liquid levels in the acid adding pots are the same; The acid adding part comprises a vacuum chamber, an acid storage chamber and a sealing gasket for sealing the mouth of the acid adding pot. The acid injection tube passes through the sealing gasket and is connected to the acid storage chamber. The negative pressure suction tube passes through the sealing gasket and is connected to the vacuum chamber. After the acid adding part seals the mouth of the acid adding pot, there is at least one acid injection tube and at least one negative pressure suction tube in the acid adding pot. The acid storage part includes an acid storage tank, and the acid inlet pipe communicates with the acid storage chamber and the acid storage tank; The vacuum pumping part includes an acid return tank, which is connected to the vacuum pump through a vacuum pumping pipe with a valve, the reflux pipe connects the acid return tank and the acid storage tank, and the acid return tank connects to the vacuum chamber through an acid return vacuum pipe.

2. The unmanned battery acid adding machine according to claim 1, characterized in that: The acid adding part is arranged above an assembly line, and the acid adding pot is arranged on the storage battery transported through the assembly line.

3. The unmanned battery acid adding machine according to claim 1, characterized in that: The upper inlet of the acid injection pipe is located at the upper part of the acid storage cavity, and the upper inlet of the negative pressure suction pipe is located at the upper part of the vacuum cavity.

4. The unmanned battery acid adding machine according to claim 1, characterized in that: The bottom outlet of the acid return vacuum pipe is located at the bottom of the acid return tank, and the bottom inlet of the vacuum pipe is located at the upper part of the acid return tank.

5. The unmanned battery acid adding machine according to claim 2, characterized in that: The assembly line is a roller conveyor belt, and guide plates for guiding and limiting the batteries are arranged on both sides of the assembly line. The assembly line is also provided with limit rods for stopping and fixing the batteries.

6. The unmanned battery acid adding machine according to claim 2, characterized in that: The assembly line is provided with a bracket for fixing a lifting mechanism, the lifting mechanism is a cylinder, and the bracket is also provided with a guide column for guiding the lifting and lowering of the acid adding part.

7. A method for acid adding by an unmanned battery acid adding machine according to any one of claims 1 to 6, characterized in that: Follow these steps: S1: After the acid adding pot is installed on the battery, it is placed together on an assembly line, and after being transported to a predetermined position, it is stopped and fixed; S2: driving the acid adding part to descend through the lifting mechanism and seal the mouth of the acid adding pot, so that at least one acid injection tube and at least one negative pressure suction tube enter the acid adding pot at the same time; S3: Close the valves on the reflux pipe and the acid inlet pipe, and the vacuum pumping unit vacuumizes the acid adding unit, the acid adding pot and the battery through the negative pressure suction pipe; S4: After the vacuum is completed, the valve on the acid inlet pipe is opened. Under the action of negative pressure, the acid in the acid storage part enters the acid adding part along the acid inlet pipe, and then is injected into the acid adding pot through the acid injection pipe, so that the acid level in the acid adding pot is higher than the bottom outlet of the negative pressure suction pipe; S5: The vacuum pumping unit extracts the acid liquid in the acid adding pot that is higher than the bottom outlet of the negative pressure suction pipe, so that the liquid level in all acid adding pots is the same. After the acid addition is completed, the valve of the acid inlet pipe is closed, the vacuum pumping is stopped, and the valve on the reflux pipe is opened to allow the acid liquid in the vacuum pumping unit to flow back to the acid storage unit; S6: The lifting mechanism drives the acid adding part to rise and leave the acid adding pot, and the assembly line transports the acid adding pot and the battery away, and then repeats the above steps.

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