CN107195850B - An automatic vacuum filling device for electrolyte - Google Patents

Abstract

An automatic vacuum electrolyte filling device comprises a rack main body, a vertical beam, a numerical control platform, a vacuum filling head, a numerical control computer system touch screen, an electrolyte hopper and a battery installation fixture. The bottom end of the vertical beam is vertically connected with the main body of the frame, the battery installation fixture is installed at the top end of the main body of the frame, a battery to be filled is installed on the battery installation fixture, the top end of the vertical beam is connected with a touch screen of a numerical control computer system, one end of a numerical control platform is connected with the vacuum filling head, and the other end of the numerical control platform is connected with an electrolyte hopper. The device adopts a stable and reliable two-dimensional numerical control platform to realize the motion positioning of the filling head, and can automatically complete the filling of the electrolyte with the precision less than 0.5ml according to the size information of the battery pack; the computer system touch screen of the device can input information such as size parameters of the battery pack and the capacity of electrolyte to be filled into the single battery, and the position of each filling port is calculated by adopting a computer.

Description

An automatic vacuum filling device for electrolyte

technical field

The invention belongs to the technical field of electrolyte filling, and relates to an automatic vacuum filling device for electrolyte.

Background technique

With the rapid development of electronic products, batteries play an increasingly important role in life. However, many large-scale manufacturers have low efficiency in producing batteries. Although they have entered the electronic era, numerical control era, and computer era, many products still use the previous manual production method in the production process. Traditional battery production relies on manual filling of electrolyte, which has low production efficiency and low precision, and cannot grasp the capacity and level of filled electrolyte in real time. The battery products produced may be far from meeting the requirements of the international market. Therefore, there is a need for a battery electrolyte automatic filling device, which can automatically realize vacuum filling of the electrolyte, fully realize automation and precision, and can automatically control the liquid level of the electrolyte filled in the battery pack at any time during the processing process. The real-time monitoring and alarming of the remaining electrolyte improves the industrial production efficiency and reduces the production cost.

Contents of the invention

The invention provides an automatic vacuum filling device for electrolyte. The device uses a stable and reliable two-dimensional numerical control platform to realize the movement and positioning of the filling head, and can automatically complete electrolyte filling with an accuracy of less than 0.5ml according to the size information of the battery pack. ; The touch screen of the computer system of the device can input information such as the size parameters of the battery pack and the capacity of the electrolyte to be filled in the single battery, and the computer is used to realize the position calculation of each filling port.

The technical scheme that the present invention takes is:

An automatic vacuum filling device for electrolyte, comprising a frame main body, a vertical beam, a numerical control platform, a vacuum filling head, a touch screen of a numerical control computer system, an electrolyte hopper, and a battery installation jig.

The bottom of the vertical beam is vertically connected with the main body of the frame, the battery installation jig is installed on the top of the main body of the rack, the battery to be filled is installed on the battery installation jig, the top of the vertical beam is connected to the touch screen of the CNC computer system, and one end of the CNC platform is connected to the vacuum filling The other end of the CNC platform is connected to the electrolyte hopper. CNC platform: used to drive the high-precision positioning of the vacuum filling head in the two-dimensional plane, and the precise positioning of the vacuum filling head can be realized by inputting the positioning coordinates.

A high-precision liquid metering control device is installed in the electrolyte hopper, and the high-precision liquid metering control device includes a non-contact liquid sensor, a measuring cup, and a control valve; the measuring cup is connected to the electrolyte hopper through a pipeline provided with a control valve, and the measuring cup is set Non-contact liquid sensor. The upper part of the electrolyte hopper is connected to a negative pressure air pump through a pipeline provided with an air pressure sensor. The non-contact liquid sensor, control valve, air pressure sensor, and negative pressure air pump are all connected to the industrial computer system, and the industrial computer system is connected to the numerical control platform, and the industrial computer system is used to realize: vacuum filling head 4, up and down motion control; Accurate liquid measurement and control; coordinated control of filling and pumping; control of pneumatic device safety and pressure stabilization device.

The vacuum filling head is connected with a miniature explosion-proof low-noise pneumatic control device to realize the up and down movement control of the filling head. The filling process adopts positive air pressure to realize filling the liquid in the measuring cup into the battery to be filled.

The main body of the frame is made of 309 stainless steel, and pulleys are installed at the bottom of the main body of the frame, which can realize mobile production and filling.

The numerical control platform is composed of a vertical axis guide rail, a horizontal axis guide rail, a two-dimensional numerical control platform, and a data line interface; the longitudinal axis guide rail is used to realize the longitudinal movement of the vacuum filling head; the horizontal axis guide rail is used to realize the horizontal movement of the vacuum filling head ; The data line interface is used to realize the communication between the two-dimensional numerical control platform and the computer system.

An automatic vacuum filling device for electrolyte of the present invention has the following technical effects:

1: The frame bed is made of 309 stainless steel with a thickness of 2mm and has the function of explosion-proof and noise-proof. Pulleys are also installed at the bottom of the device, which can realize mobile production and filling.

2: The numerical control platform mainly realizes the high-precision positioning of the filling head in the two-dimensional plane, and only needs to input the positioning coordinates to realize the precise positioning of the filling head. In the present invention, an explosion-proof high-precision two-dimensional numerical control platform is used, and the positioning accuracy is better than 0.1 mm. During use, the coordinate data is input to the platform through a numerical control computer to complete the operation;

3: The high-precision CNC platform is mainly composed of a vertical axis guide rail, a vacuum filling head, a horizontal axis guide rail, a two-dimensional CNC table and a data line interface. The longitudinal axis guide rail mainly realizes the longitudinal movement of the filling head, the horizontal axis guide rail mainly realizes the lateral movement of the filling head, and the data line interface mainly realizes the communication between the two-dimensional numerical control platform and the computer system. The two-dimensional high-precision numerical control platform can drive the vacuum filling head or the battery pack to realize the filling of the electrolyte of each single battery in the battery pack. Large, so it needs a large space for movement, and if the weight of the battery pack is large, it needs to use a hydraulic device to carry it. The hydraulic device is large in size and has shortcomings such as oil pollution. Therefore, this equipment adopts a two-dimensional Movement and up and down motion realize automatic filling of electrolyte.

4: The computer system adopts the industrial computer system, which mainly realizes the two-dimensional high-precision numerical control platform, the up and down movement control of the filling head, the high-precision liquid measurement and control, the coordinated control of filling and pumping, and the control of the safety and voltage stabilizing device of the pneumatic device.

5: The filling head motion control and filling realization device adopts pneumatic control. Since the filling head has a small mass, the pneumatic power used is relatively small. In the present invention, a miniature explosion-proof low-noise pneumatic control device is used to realize the up and down movement control of the filling head , The filling process uses positive air pressure to fill the liquid in the measuring cup into the battery pack.

6: A high-precision liquid metering control device is installed in the electrolyte hopper. Since it is difficult to directly measure the high-precision dynamics of the electrolyte, and the electrolyte is a corrosive liquid, the non-contact liquid level detection can be used in the present invention. Realize high-precision liquid level detection instead of high-precision flow monitoring. The present invention adopts the flow liquid level control system with feedback, as long as the liquid liquid level of the amount is accurately controlled, the volume of the electrolyte solution in the measuring cup can be controlled. This equipment adopts a non-contact liquid sensor with an accuracy of 0.1mm, a measuring cup with a diameter of 60mm and a control valve resistant to strong alkali corrosion.

7: The reason for using the feedback control system is that the liquid level of the electrolyte hopper decreases with the filling process, so the flow rate of the pipeline is also changing, so the outflow volume cannot be directly determined by time control. The device uses the gravity of the fluid to realize the quantitative feeding of the electrolyte hopper to the measuring cup, and the liquid pump is omitted. Because it is difficult to find a liquid pump that is resistant to strong alkali corrosion and does not contaminate the electrolyte with impurities during the wear process in the existing market. In order to completely abandon valves and liquid pumps in the process of electrolyte flow control, this device uses gas pressure to realize fluid flow control.

8: Using gas pressure to realize the flow control principle of the fluid is as follows: 1) Using the negative pressure air pump to control the air pressure in the upper part of the electrolyte hopper can realize the flow and stop of the fluid; 2) High precision pressure sensor and negative pressure air pump 3) If it is necessary to add electrolyte to the measuring cup, reduce the negative air pressure in the upper part of the hopper. When increasing the flow rate, you can gradually reduce the negative pressure until the negative pressure is zero. At this time, the flow rate is the largest. ; 4) When the liquid level in the measuring cup reaches the designed liquid level, the negative pressure can be gradually increased, thereby reducing the flow until the fluid stops flowing; 5) The detection and control of the liquid level and the detection and control of the negative pressure constitute a typical The closed-loop control system adopts the closed-loop liquid level control algorithm to accurately control the liquid level of the measuring cup, so as to accurately obtain the volume of the electrolyte; 6) This equipment has very low requirements for negative pressure, which can be completed by using a vacuum pump with a small power; 7 ) Through precise pressure control, the flow rate of the electrolyte vector cup can be controlled, so as to achieve precise liquid level control, which also realizes precise volume control of the electrolyte; 8) The highest and lowest liquid level warning lines are the automatic liquid level detection of the equipment Realize that if the liquid exceeds the warning level, the alarm will be automatically eliminated after the alarm is resolved; 9) The staff can set the position of the alarm line by themselves.

Description of drawings

Fig. 1 is the overall structure diagram of the present invention.

Fig. 2 is a control substructure diagram of the industrial computer system of the present invention.

Fig. 3 is a structural diagram of the two-dimensional high-precision numerical control platform of the present invention.

Fig. 4 is a principle diagram of liquid filling of the pneumatic device of the present invention.

Fig. 5 is a principle diagram of fluid flow control using gas pressure in the present invention.

Fig. 6 is a state diagram of fluid flow control using gas pressure in the present invention.

Figure 7 is a closed-loop control structure diagram.

Fig. 8 is a diagram of the liquid level control system of the water tank.

Detailed ways

As shown in Figure 1, an automatic electrolyte vacuum filling device includes a frame body 1, a vertical beam 2, a numerical control platform 3, a vacuum filling head 4, a touch screen of a numerical control computer system 5, an electrolyte hopper 6, and a battery installation card Tool 7. The bottom of the vertical beam 2 is vertically connected with the frame main body 1, the battery installation jig 7 is installed on the top of the rack main body 1, the battery to be filled 8 is installed on the battery installation jig 7, and the top of the vertical beam 2 is connected to the touch screen 5 of the numerical control computer system , one end of the numerical control platform 3 is connected to the vacuum filling head 4 , and the other end of the numerical control platform 3 is connected to the electrolyte hopper 6 . The numerical control platform 3 is used to drive the high-precision positioning of the vacuum filling head 4 in the two-dimensional plane, and the precise positioning of the vacuum filling head 4 can be realized by inputting positioning coordinates.

A high-precision liquid metering control device is installed in the electrolyte hopper 6, and the high-precision liquid metering control device includes a non-contact liquid sensor 9, a measuring cup 10, and a control valve. The measuring cup 10 is connected to the electrolyte hopper 6 through a pipeline provided with a control valve, and a non-contact liquid sensor 9 is arranged in the measuring cup 10 . The upper part of the electrolyte hopper 6 is connected to a negative pressure air pump 12 through a pipeline provided with an air pressure sensor 11 . The non-contact liquid sensor 9, the control valve, the air pressure sensor 11, and the negative pressure air pump 12 are all connected to the industrial computer system, and the control substructure diagram of the industrial computer system is as shown in Figure 2. The industrial computer system is connected to the numerical control platform 3, and the industrial computer system It is used to realize: vacuum filling head 4, up and down motion control; high-precision liquid measurement and control; filling and pumping coordination control; pneumatic device safety voltage stabilizing device control.

The vacuum filling head 4 is connected to a miniature explosion-proof low-noise pneumatic control device. In the present invention, the piston air motor of the 8AM1 model is selected to realize the up and down motion control of the filling head. The filling process adopts positive air pressure to realize the measurement cup The liquid in 10 is injected in the battery 8 to be filled.

Made of 309 stainless steel, pulleys are installed at the bottom of the frame main body 1, which can realize mobile production and filling. The structural diagram of the two-dimensional high-precision numerical control platform is shown in Figure 3. The numerical control platform 3 is composed of a vertical axis guide rail 3.1, a horizontal axis guide rail 3.2, a two-dimensional numerical control table 3.3, and a data line interface 3.4; the longitudinal axis guide rail 3.1 is used to realize The vacuum filling head 4 moves vertically; the horizontal axis guide rail 3.2 is used to realize the horizontal movement of the vacuum filling head 4; the data line interface 3.4 is used to realize the communication between the two-dimensional numerical control table 3.3 and the computer system. The two-dimensional high-precision numerical control platform can drive the vacuum filling head or the battery pack to realize the filling of the electrolyte of each single battery in the battery pack, but if the movement of the battery pack is used to realize it, due to the large size of the battery pack, Therefore, a larger movement space is required, and if the weight of the battery pack is large, a hydraulic device is required to carry it. The hydraulic device is large in size and has shortcomings such as oil pollution. Therefore, this equipment adopts the two-dimensional movement and control of the filling head. Up and down movement realizes automatic filling of electrolyte.

An automatic vacuum filling equipment for electrolyte of the present invention, the principle diagram of the liquid filling of the air pressure device is shown in Figure 4 . Figure (a) is the process of electrolyte hopper filling the measuring cup with electrolyte. When the liquid level in the measuring cup reaches the designed liquid level, the fluid stops flowing; pressure, the piston moves downward, and the liquid in the measuring cup is injected into the battery; in figure (c), when the liquid in the measuring cup is filled into the battery, the positive pressure is gradually reduced, and the piston moves upward; in figure (d), until the positive pressure Reduced to a minimum value, when the piston moves to the top, the system is ready to enter the electrolyte hopper to fill the measuring cup and enter the cycle.

The invention is an automatic vacuum filling equipment for electrolyte, which utilizes the gas pressure fluid flow control principle as shown in Figures 5 and 6. Because the electrolyte is highly corrosive, general valves and liquid pumps cannot control its flow, and the impurities brought by corrosion will pollute the electrolyte. The negative pressure air pump 12 is used to control the flow of the fluid.

Figure (a) is the process of filling the electrolyte hopper to the precise measuring cup through the negative pressure air pump; in figure (b), when the system issues a command to fill the measuring cup, the negative pressure above the electrolyte hopper is increased by the negative pressure air pump , the electrolyte in the electrolyte hopper flows into the measuring cup through the pipeline; in figure (c), the negative pressure above the electrolyte hopper continues to increase through the negative pressure air pump, and the electrolyte hopper continues to inject the electrolyte into the measuring cup until the set In figure (d), when the electrolyte in the measuring cup is filled to the set level, the negative pressure is reduced by the negative pressure air pump, and the electrolyte hopper stops filling the vector cup with electrolyte.

An automatic vacuum filling method for electrolyte, which uses a miniature explosion-proof low-noise pneumatic control device to realize the up and down movement control of the vacuum filling head 4, and uses positive air pressure in the filling process to realize filling the liquid in the measuring cup 10 to be added In note battery 8. The gravity of the fluid is used to realize the quantitative feeding of the electrolyte hopper 6 to the measuring cup 10, and the gas pressure is used to control the flow of the fluid.

An electrolyte automatic vacuum filling method,

1), the negative pressure air pump 12 is used to control the air pressure of the upper part of the electrolyte hopper 6 to realize the flow and stop of the fluid;

2), adopt air pressure sensor 11 and negative pressure air pump 12, realize the precise control of air pressure in the upper half of electrolyte hopper 6; During the flow rate, the negative pressure can be gradually reduced until the negative pressure is zero, and the flow rate is the largest at this time;

When the liquid level in the measuring cup 10 reaches the designed liquid level, the negative pressure can be gradually increased, thereby reducing the flow rate until the fluid stops flowing;

3), the detection and control of the liquid level and the detection and control of the negative pressure constitute a typical closed-loop control system, using a closed liquid level control algorithm to accurately control the liquid level of the measuring cup 10, thereby accurately obtaining the volume of the electrolyte; through Accurate pressure control can control the flow rate of the electrolyte vector cup 10 , thereby realizing precise liquid level control, and also realizing accurate volume control of the electrolyte.

The closed liquid level control algorithm is used to realize liquid level data detection and liquid level prediction, and the basic function of the liquid level control system is to automatically adjust the liquid level height to the set value by controlling the transmitter after setting the liquid level height; If there is an error in the automatic adjustment, switch to manual adjustment and diagnosis; analyze the system's dynamic performance indicators such as steady-state error, overshoot, and adjustment time through real-time curves,

The closed liquid level control algorithm mainly realizes liquid level data detection and liquid level prediction. The basic function of the liquid level control system is to automatically adjust the liquid level to the set value by controlling the transmitter after setting the liquid level. If there is an error in automatic adjustment, it can be switched to manual adjustment and diagnosis. Real-time curves can be used to analyze dynamic performance indicators such as system steady-state error, overshoot, and adjustment time. The inventive system of the present invention consists of four basic links, namely the controlled object, the measuring and transmitting device, the controller and the actuator. The closed-loop control structure is shown in Figure 7. The water tank liquid level control system can be designed according to the closed-loop control system, and the designed water tank liquid level control system is shown in Figure 8.

In the liquid level control system of the present invention, the single-loop regulation system generally uses one regulator on one regulation object to keep a parameter constant, and the regulator only accepts one measurement signal, and its output only controls one actuator. Computer control is different from traditional analog control. It adopts a sampling control, which can only be calculated and controlled according to the deviation value at the sampling time. Can't output control quantity continuously like analog quantity control to carry out contact control. Therefore, the integral term and differential term in analog quantity control must be discretized. According to the relevant knowledge of digital signal processing, discretization processing: the discrete sampling time KT corresponds to the continuous time (where K is the sampling number, T is the sampling period), and the integral is replaced by the summation, and the differential is replaced by the incremental form. Perform an approximate transformation to get:

In the formula, K is the sampling number, K=0,1,2,3,...; u _k is the input deviation value at the Kth sampling moment; e _k-1 is the K-1th sampling moment K ₁ =K _P T/T ₁ ; K _D is a differential constant; K _D =K _P T _D /T; u ₀ is a control constant. When the sampling period T is small enough, the above calculation results can be accurate enough, and the discrete control process can be approximately regarded as a continuous control process. The above-mentioned process uses all the control quantities, so it is called full-quantity or position-based PID control algorithm. Because it is full output, each output result is related to the past state. The calculation formula accumulates e _k , the workload is heavy and the actual position of the actuator corresponding to the controller output u _k , when the controller fails, if A large change in the output will cause a large change in the actuator, which may cause serious production accidents. Incremental PID means that the output of the digital controller is only the increment △u _k of the control quantity. When the control quantity required by the actuator is increment instead of position, the incremental PID algorithm can be used for control. From formula (1), the output value of the controller at the K-1 sampling moment can be obtained as:

Subtracting and sorting out the two formulas, the incremental PID control algorithm formula can be obtained as:

上式中，△u_k还可以写成下面的形式：In the formula,

In the above formula, △u _k can also be written in the following form:

In the formula, △e _k ＝e _k -e _k-1 ; I＝e _k -2e _k-1 +e _k-2 ＝△e _k -△e _k-2 ; I＝T/T _I ; D＝T _D /T

It can be seen from the above formula that if the computer control system adopts a constant sampling period T, once A, B, and C are determined, as long as the deviation values of the three measurements before and after are used, the control increment can be calculated, which is different from the positional algorithm. Compared with , the amount of calculation is much smaller.

An electrolyte automatic vacuum filling method, comprising the following steps:

1) Turn on the power of the automatic detection device, and display the self-test result on the touch screen. After the self-test is successful, enter the next step. If the self-test is not successful, perform maintenance according to the self-test error message;

2) If there is an alarm for the remaining electrolyte in the hopper, it is necessary to add electrolyte, and the device will automatically cancel the alarm;

3) Manually load the battery pack to be filled;

4) Select the size parameter information of the battery pack to be filled: battery model, external dimension, single battery size and arrangement; if the information of the last filled battery is used, the number will automatically add "1", and the rest select the default value That's it.

5), start the filling process;

6) After the filling is completed, the equipment system automatically saves various information of the battery pack: battery pack information, start and end time of filling; it can be checked through the touch screen. If you want to continue filling the next battery pack, return to 2), otherwise you can choose standby and shutdown.

Claims (9)

1. An automatic vacuum filling device for electrolyte, characterized in that it comprises: frame main body (1), vertical beam (2), numerical control platform (3), vacuum filling head (4), numerical control computer system touch screen (5 ), electrolyte hopper (6), battery installation jig (7); the bottom end of the vertical beam (2) is vertically connected with the frame main body (1), and the battery installation jig (7) is installed on the top of the rack main body (1) , the battery to be filled (8) is installed on the battery installation jig (7), the top of the vertical beam (2) is connected to the touch screen (5) of the numerical control computer system, one end of the numerical control platform (3) is connected to the vacuum filling head (4), and the numerical control The other end of the platform (3) is connected to the electrolyte hopper (6); the numerical control platform (3) is used to drive the high-precision positioning of the vacuum filling head (4) in the two-dimensional plane, and the vacuum filling can be realized by inputting the positioning coordinates Precise positioning of the head (4); A high-precision liquid metering control device is installed in the electrolyte hopper (6), and the high-precision liquid metering control device includes a non-contact liquid sensor (9), a measuring cup (10), and a control valve; The measuring cup (10) is connected to the electrolyte hopper (6) through a pipe provided with a control valve, a non-contact liquid sensor (9) is arranged in the measuring cup (10), and the upper part of the electrolyte hopper (6) passes through a pipe provided with an air pressure sensor (11). The negative pressure air pump (12) is connected with the negative pressure air pump (12); the negative pressure air pump (12) is used to control the air pressure of the upper part of the electrolyte hopper (6), so as to realize the flow and stop of the fluid; the air pressure sensor (11) and the negative pressure air The pump (12) realizes the precise control of the air pressure in the upper part of the electrolyte hopper (6); if it is necessary to fill the electrolyte into the measuring cup (10), the negative pressure of the air in the upper part of the electrolyte hopper (6) can be reduced, and the flow rate can be increased. Gradually reduce the negative pressure until the negative pressure is zero, and the flow is maximum at this time; when the liquid level in the measuring cup (10) is approaching the designed liquid level, the negative pressure can be gradually increased, thereby reducing the flow until the fluid stops flowing; The non-contact liquid sensor (9), control valve, air pressure sensor (11), and negative pressure air pump (12) are all connected to an industrial computer system, and the industrial computer system is connected to a numerical control platform (3); The industrial computer system is used to realize: the up and down movement control of the vacuum filling head (4); high-precision liquid measurement and control; the coordinated control of filling and pumping; and the control of the safety voltage stabilizing device of the pneumatic device. 2. An automatic vacuum filling device for electrolyte according to claim 1, characterized in that: the vacuum filling head (4) is connected to a miniature explosion-proof low-noise pneumatic control device to realize the up and down motion control of the filling head , the filling process adopts positive air pressure to realize filling the liquid in the measuring cup (10) into the battery (8) to be filled. 3. An automatic vacuum filling device for electrolyte according to claim 1, characterized in that: the frame body (1) is made of 309 stainless steel, and pulleys are installed at the bottom of the frame body (1) , which can realize mobile production filling. 4. A kind of electrolyte automatic vacuum filling device according to claim 1, characterized in that: said numerical control platform (3) is composed of vertical axis guide rail (3.1), horizontal axis guide rail (3.2), two-dimensional numerical control table (3.3 ), data line interface (3.4) composition; The longitudinal axis guide rail (3.1) is used to realize the longitudinal movement of the vacuum filling head (4); The horizontal axis guide rail (3.2) is used to realize the lateral movement of the vacuum filling head (4); The data line interface (3.4) is used to realize the communication between the two-dimensional numerical control platform (3.3) and the computer system. 5. adopt the electrolyte automatic vacuum filling method of vacuum filling device as claimed in claim 1, it is characterized in that: adopt miniature explosion-proof low-noise pneumatic control device to realize the up and down motion control of vacuum filling head (4), add The injection process adopts positive air pressure to realize filling the liquid in the measuring cup (10) into the battery (8) to be filled. 6. Adopt the electrolyte automatic vacuum filling method of vacuum filling device as claimed in claim 1, it is characterized in that: utilize the gravity of fluid to realize, the quantitative feeding of electrolyte hopper (6) to measuring cup (10) adopts gas pressure To achieve fluid flow control. 7. adopt the electrolyte automatic vacuum filling method of vacuum filling device as claimed in claim 1, it is characterized in that: 1), the negative pressure air pump (12) is used to control the air pressure of the upper part of the electrolyte hopper (6), so as to realize the flow and stop of the fluid; 2), using the air pressure sensor (11) and the negative pressure air pump (12), to realize the precise control of the air pressure in the upper half of the electrolyte hopper (6); If it is necessary to add electrolyte to the measuring cup (10), lower the air negative pressure on the upper part of the electrolyte hopper (6), and gradually reduce the negative pressure when increasing the flow until the negative pressure is zero, at which time the flow is maximum; When the liquid level in the measuring cup (10) approaches the designed liquid level, the negative pressure can be gradually increased, thereby reducing the flow rate until the fluid stops flowing; 3) The detection and control of the liquid level and the detection and control of the negative pressure constitute a typical closed-loop control system. The closed liquid level control algorithm is used to accurately control the liquid level of the measuring cup (10), thereby accurately obtaining the volume of the electrolyte The flow velocity of the electrolyte vector cup (10) can be controlled through precise pressure control, thereby realizing precise liquid level control and precise volume control of the electrolyte. 8. A method for automatic vacuum filling of electrolyte according to claim 7, characterized in that: the closed liquid level control algorithm is used to realize liquid level data detection and liquid level prediction, and the basic function of the liquid level control system is to set After the liquid level is high, the liquid level is automatically adjusted to the set value by controlling the transmitter; if an error occurs in the automatic adjustment, switch to manual adjustment and diagnosis; analyze the system's steady-state error, overshoot, and Adjusting time and other dynamic performance indicators, the closed liquid level control algorithm is composed of four basic links, namely the controlled object, measuring and transmitting device, controller and actuator; In the liquid level control system, the single-loop regulation system generally uses a regulator on an regulation object to keep a parameter constant, and the regulator only accepts a measurement signal, and its output only controls one actuator; computer control and traditional It is different from the analog quantity control, which adopts a kind of sampling control, which can only be calculated and controlled according to the deviation value at the sampling time; it cannot continuously output the control quantity to carry out contact control like the analog quantity control; therefore, the integral term in the analog quantity control The sum and differential items must be discretized. According to the relevant knowledge of digital signal processing, the discretization process: the discrete sampling time KT corresponds to the continuous time, where K is the sampling number, T is the sampling period, and the integral is replaced by the summation. The incremental form replaces the differential, and an approximate transformation can be performed to obtain:

In the formula, K is the sampling number, K=0,1,2,3,...; u _k is the input deviation value at the Kth sampling moment; e _k-1 is the K-1th sampling moment K ₁ ＝K _P T/T ₁ ; K _D bit differential constant; K _D ＝K _P T _D /T; u ₀ is the control constant. When the sampling period T is small enough, the above calculation results can reach enough Accurate, the discrete control process can be approximately regarded as a continuous control process; the above process uses all control quantities, so it is called a full-scale or position-based PID control algorithm, because it is a full-scale output, so each output result is related to the past state. The calculation formula accumulates e _k , the workload is heavy, and the actual position of the actuator corresponding to the controller output u _k , when the controller fails, if the output changes greatly, it will cause a large change in the actuator, which may Cause serious production accidents; Incremental PID means that the output of the digital controller is only the increment △u _k of the control amount. When the control amount required by the actuator is an increment instead of a position, the incremental PID algorithm can be used. Control; from formula (1), the output value of the controller at the K-1 sampling moment is:

Subtracting and sorting out the two formulas, the incremental PID control algorithm formula can be obtained as:

In the formula,

In the above formula, △u _k can also be written in the following form:

In the formula, △e _k ＝e _k -e _k-1 ; I＝e _k -2e _k-1 +e _k-2 ＝△e _k -△e _k-2 ; I＝T/T _I ; D＝T _D /T. 9. adopt the electrolyte automatic vacuum filling method of vacuum filling device as claimed in claim 1, it is characterized in that comprising the following steps: 1) Turn on the power of the automatic detection device, and display the self-test result on the touch screen. After the self-test is successful, enter the next step. If the self-test is not successful, perform maintenance according to the self-test error message; 2) If there is an alarm for the remaining electrolyte in the hopper, it is necessary to add electrolyte, and the device will automatically cancel the alarm; 3) Manually load the battery pack to be filled; 4) Select the size parameter information of the battery pack to be filled: battery model, external dimension, single battery size and arrangement; if the information of the last filled battery is used, the number will automatically add "1", and the rest select the default value can; 5), start the filling process; 6) After the filling is completed, the equipment system automatically saves the information of the battery pack: battery pack information, filling start and end time; you can check it through the touch screen; if you want to continue filling the next battery pack, return to 2 ), otherwise you can choose Standby and Shutdown.

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