Negative pressure detection method of vacuum sealer

Abstract

The invention discloses a negative pressure detection method for a vacuum sealer, which comprises the following steps: S1, putting an object to be sealed into a vacuum cavity of the vacuum sealer, starting the vacuum sealer, and starting vacuumizing operation; s2, the rotating speed of the motor is monitored in real time through a first monitoring module, and when the negative pressure of the vacuum cavity is increased, the air exhaust resistance is increased, and the rotating speed of the motor is reduced; s3, in the air exhaust process, the control module continuously and jointly controls the first monitoring module, and the negative pressure value in the vacuum cavity is cooperatively calculated based on the numerical change of the rotating speed of the motor; the real-time chamber pressure is displayed through the display module; by monitoring the rotating speed and the current of the motor in real time and cooperatively calculating the negative pressure value in the vacuum cavity, the problems that in the vacuumizing operation of the sealing machine, negative pressure control is unstable, energy consumption is too high, real-time monitoring is lacked, equipment is excessively abraded, and the system adjusting response speed is low are solved. Through the improvements, the packaging quality is improved, the energy consumption is reduced, and the service life of equipment is prolonged.

Description

Technical Field

[0001] The invention discloses a negative pressure detection method for a vacuum sealing machine, belonging to the technical field of vacuum sealing machines. Background Art

[0002] A vacuum sealer is a device used to package items. It mainly creates a vacuum environment by extracting the air from the packaging bag or container, thereby sealing the items. It is widely used in the packaging of food, medicine, electronic products and other items that need to be stored for a long time and are moisture-proof and anti-oxidation.

[0003] Since different packaging items require different vacuum levels, it is difficult to ensure the reliability of each packaging operation without an accurate negative pressure monitoring system. As the negative pressure in the vacuum chamber increases, the air extraction resistance will also increase, causing the motor load to increase. If the current is not adjusted in time, the motor may continue to operate in an inefficient state, increasing energy consumption. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a negative pressure detection method for a vacuum sealing machine to solve the problems of the prior art.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions: A negative pressure detection method for a vacuum sealing machine, comprising the steps of: S1: Place the object to be sealed into the vacuum chamber of the vacuum sealer, start the vacuum sealer, and start the vacuum operation; S2: The motor speed is monitored in real time through the first monitoring module. When the negative pressure in the vacuum chamber increases, the air extraction resistance increases and the motor speed decreases; S3: During the vacuuming process, the control module continuously controls the first monitoring module, and collaboratively calculates the negative pressure value in the vacuum chamber based on the numerical change of the motor speed; and displays the real-time chamber pressure through the display module; S4: When the negative pressure value reaches the preset target value, the control module immediately sends a command to turn off the motor in the vacuum pump and stop the vacuum operation; S5: The sealing machine enters a vacuum state and prepares for the next sealing operation.

[0006] The beneficial effects of the present invention are: The present invention accurately controls the negative pressure in the vacuum chamber by real-time monitoring of the motor speed and current, thereby ensuring the efficiency and stability of the sealing operation. The operation steps include placing the article into the vacuum chamber, starting the equipment to evacuate the vacuum chamber, detecting the change in the motor speed through the first monitoring module, and when the speed drops to a preset value, the control module maintains the efficient operation of the motor by adjusting the current. At the same time, the second monitoring module adjusts the current according to the change in the motor current to ensure that the system maintains efficiency when the negative pressure increases. During the whole process, the system will calculate and display the negative pressure value in the vacuum chamber in real time based on the motor parameters. When the negative pressure reaches the target value, the equipment automatically stops the vacuum operation, enters the vacuum holding state, and finally performs the heat sealing operation. The method realizes automated control, precise negative pressure monitoring, and energy-saving and efficient packaging process, improves the sealing quality and extends the service life of the equipment.

[0007] By real-time monitoring of the motor speed and current, and collaborative calculation of the negative pressure value in the vacuum chamber, the sealing machine solved the problems of unstable negative pressure control, excessive energy consumption, lack of real-time monitoring, excessive equipment wear, and slow system adjustment response during vacuum operation. These improvements have improved packaging quality, reduced energy consumption, and extended the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 It is a step diagram of a negative pressure detection method of a vacuum sealing machine of the present invention. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0011] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0012] Reference Figure 1 As shown, a negative pressure detection method for a vacuum sealing machine comprises the following steps: S1: Place the object to be sealed into the vacuum chamber of the vacuum sealer, start the vacuum sealer, and start the vacuum operation; S2: monitor the motor speed in real time through the first monitoring module. When the negative pressure of the vacuum chamber increases, the suction resistance increases, and the motor speed is lower than the first preset value, increase the motor speed and restore it to the initial motor speed; S3: During the vacuuming process, the control module continuously controls the first monitoring module, and collaboratively calculates the negative pressure value in the vacuum chamber based on the value change thereof; and displays the real-time chamber pressure through the display module; S4: When the negative pressure value reaches the preset target value, the control module immediately sends a command to turn off the motor in the vacuum pump and stop the vacuum operation; S5: The sealing machine enters a vacuum state and prepares for the next sealing operation.

[0013] By real-time monitoring of the motor speed and current, the negative pressure in the vacuum chamber is accurately controlled to ensure the efficiency and stability of the sealing operation. The operation steps include placing the items in the vacuum chamber, starting the equipment to evacuate, detecting the change in motor speed through the first monitoring module, and when the speed drops to the preset value, the control module maintains the efficient operation of the motor by adjusting the current. At the same time, the second monitoring module adjusts the current according to the change in motor current to ensure that the system maintains efficiency when the negative pressure increases. During the whole process, the system will calculate and display the negative pressure value in the vacuum chamber in real time based on the motor parameters. When the negative pressure reaches the target value, the equipment automatically stops the vacuum operation, enters the vacuum holding state, and finally performs the heat sealing operation. This method realizes automated control, precise negative pressure monitoring, and energy-saving and efficient packaging process, improves the sealing quality and extends the service life of the equipment.

[0014] In step S2, it also includes that when the speed of the motor is lower than the first preset value, the control module adjusts the current through the regulating module; The motor speed is monitored in real time by the first monitoring module, specifically including: The first monitoring module uses a speed sensor to measure the speed of the motor and capture the speed signal of the motor in real time. The speed sensor converts the speed signal into a digital pulse signal and inputs it into the data acquisition module. The data acquisition module is connected to the control module.

[0015] The frequency of data acquisition is set at the millisecond level to ensure that any slight fluctuation in the motor speed can be captured, and the sensor is installed on the shaft of the motor. The speed sensor can use a Hall effect sensor or a photoelectric encoder.

[0016] As the air in the vacuum chamber is gradually pumped out, the air pressure in the chamber decreases and the negative pressure gradually increases. As the air density in the chamber decreases, the resistance to air extraction increases, and the motor needs to overcome greater resistance, which is manifested as an increase in the motor load, resulting in a decrease in motor speed.

[0017] Through the speed data continuously collected by the first monitoring module, the control module can detect the gradual decrease in the motor speed.

[0018] In step S2, when the negative pressure of the vacuum chamber increases, the air extraction resistance increases, and the speed of the motor is lower than the first preset value, the control module adjusts the current through the regulating module, specifically including: The first preset value is the minimum speed of the motor under low load. The algorithm running in the control module will compare the speed data collected in real time with the first preset value. If the current speed is found to be lower than the preset value, it will be considered that the motor load is too large and current adjustment will be performed.

[0019] In step S2, the motor current is monitored by the second monitoring module, and the current is increased to a second preset value by the regulating module to increase the motor speed and restore the motor speed to the initial motor speed; specifically, the following steps are included: The control module starts the PID controller, which calculates the current increment that needs to be adjusted based on the speed drop. The control module sends instructions to the regulation module based on the output of the PID controller to adjust the input current of the motor.

[0020] The regulating module may be a power control module, which increases the power output of the motor by adjusting the current output to the motor.

[0021] The regulating module increases the motor's torque output by increasing the motor's power supply current, thereby offsetting the effect of increased suction resistance and restoring the motor speed to the original set value. At this time, the current increase is usually limited to a second current preset value to prevent the motor from overloading.

[0022] Among them, closed-loop control algorithms such as PID controllers (proportional-integral-differential controllers) are used. For example, the greater the speed drop, the greater the current increment calculated by the PID controller will be to restore the speed as quickly as possible.

[0023] The control module sends instructions to the regulating module according to the output of the PID controller to adjust the input current of the motor. The regulating module can be a power control module, which increases the power output of the motor by adjusting the current output to the motor.

[0024] When the regulating module increases the current, the first monitoring module continues to monitor the change in the motor speed. The control module compares the new speed with the initial speed value to ensure that the motor speed has returned to the normal range.

[0025] If the speed still has not recovered, the control module will further adjust the current until the speed reaches the set value or reaches the safety limit of the current.

[0026] To avoid overload or excessive current, the control module is equipped with a safety protection mechanism. If the current exceeds the safety threshold, the system will stop adjusting and issue an alarm.

[0027] It should be emphasized that the first monitoring module needs to use a high-precision speed sensor to ensure that any slight changes in the motor speed can be monitored in real time and accurately. The control module must have high-frequency data acquisition and processing capabilities so that adjustment decisions can be made as soon as the speed drops. The PID controller needs to be carefully tuned to ensure that the current adjustment can quickly and stably restore the motor speed without overshoot or unstable adjustment. The current adjustment should be carried out within a safe range to prevent the motor from being damaged due to overload. Therefore, the system needs to set an upper limit value for the current. Once the current exceeds the preset value, the system will automatically trigger the protection mechanism.

[0028] In step S2, the second monitoring module monitors the working current of the motor in real time through a current sensor. The current sensor is installed on the power line of the motor. The current sensor converts the detected current signal into a readable voltage signal, and converts it into a digital signal through an analog-to-digital converter (ADC) and transmits it to the control module.

[0029] The second monitoring module needs high frequency sampling to track the current fluctuation in real time. The current sensor can be a Hall effect current sensor or a shunt.

[0030] The change in the motor's current directly reflects its load condition. When the vacuum resistance in the vacuum chamber increases, the motor load increases, causing the current to rise. The control module uses the current data collected by the second monitoring module to analyze the motor's load condition in real time.

[0031] When the system starts, a second preset value of current is set. This preset value is based on the normal working load range of the motor to ensure that the current of the motor can support the recovery to the initial speed. The preset value is usually determined by calculation and debugging based on the motor characteristics and the range of variation of the exhaust load.

[0032] In step S2, the second preset value is adjusted in a range of 0.1A-0.3A.

[0033] In the vacuum sealer system, the load change of the motor will cause the current to change. To ensure that the motor can quickly return to the initial speed when the load changes, the system needs to carefully adjust the current. Setting the adjustment range from 0.1A to 0.3A can provide sufficient current adjustment to ensure that the motor can respond accurately under different load conditions.

[0034] Too large an adjustment range may result in excessive current adjustment, which may cause overheating of the motor or excessive wear of mechanical parts. Too small an adjustment range may not be sufficient to cope with large load fluctuations. The range of 0.1A to 0.3A provides a reasonable balance that can effectively adjust the current without threatening the stable operation and safety of the motor.

[0035] If the current adjustment range is too large, the motor may frequently enter an overload state, increase motor wear and shorten its service life. By controlling the adjustment range to 0.1A to 0.3A, overload caused by excessive current increase can be effectively avoided.

[0036] The goal of the PID controller is to restore the motor speed to the target value quickly and smoothly. Setting the current adjustment range between 0.1A and 0.3A allows the PID controller to perform more delicate control during the adjustment process, avoiding excessive (overshoot) or insufficient (slow response) current adjustment. This range can well match the adjustment characteristics of the PID algorithm, making the system respond quickly and stably.

[0037] The adjustment range is between 0.1A and 0.3A, which can quickly adjust the motor current when the load changes, ensuring that the motor can return to the initial speed in a shorter time. This improves the response speed and control accuracy of the system, especially when the pumping resistance changes rapidly.

[0038] Fine current control can prevent the motor from losing more energy due to too high or too low current. Such settings help reduce the motor's operating energy consumption, reduce heat loss and mechanical wear, and thus extend the motor's service life.

[0039] Through a reasonable current adjustment range, the system can better protect the motor from overload and overheating. The control module can accurately adjust the current when the load changes, avoiding damage to the motor and improving the safety and reliability of the overall system.

[0040] Stable and moderate current regulation can reduce the stress on mechanical and electronic components in the system and prevent vibration and shock caused by excessive or unstable current regulation, thereby improving the reliability of the entire system.

[0041] The algorithm in the control module will compare the real-time current data of the second monitoring module with the second preset current value. If the current is not enough to maintain or restore the motor speed, the control module will increase the current output through the adjustment module. In this embodiment, the initial adjustment is 0.1A, and the maximum does not exceed 0.3A each time. The adjustment interval is 1-2S.

[0042] In step S3, after receiving the instruction from the control module, the regulating module increases the power supply current of the motor through the electronic regulator or the power control module. PWM control increases the current output by adjusting the duty cycle of the current, thereby increasing the torque of the motor and restoring the speed of the motor.

[0043] Among them, the electronic regulator can use a pulse width modulator PWM.

[0044] The speed of the motor is closely related to its supply current. By increasing the current, the power output of the motor increases, which can overcome the suction resistance and increase the speed.

[0045] During the current adjustment process, the first monitoring module continuously monitors the speed change of the motor, and the second monitoring module continues to monitor the current change. The control module adjusts the current output according to the real-time feedback until the speed of the motor returns to the initial setting value. If the speed has not recovered after the current is increased, the control module will continue to increase the current until it reaches the upper limit of the safety range.

[0046] During the entire current adjustment process, the control module continuously compares the current motor speed with the initial speed and optimizes the current adjustment accordingly. This process is dynamic, and the control module continuously adjusts the current size according to the real-time operating status of the system. In order to protect the motor and the system, the control module sets a current upper limit protection mechanism. When the current exceeds the set safety threshold (for example, exceeding 80-90% of the rated current of the motor), the system will trigger protection to prevent the motor from overloading and burning.

[0047] It should be emphasized that the second monitoring module needs to use a high-precision and fast-responding current sensor to ensure that current changes can promptly reflect changes in motor load. The regulation of current requires the use of a closed-loop control system (such as PID control) to ensure the smoothness and accuracy of current regulation and prevent over- or under-regulation. The setting of the first preset value of the current must ensure that when the suction resistance increases, the system has sufficient current to increase the motor speed without exceeding the safety range. The recovery of the motor speed depends not only on a single current regulation, but also on the feedback control mechanism. The dynamic adjustment of current and speed is achieved through the joint feedback of the first monitoring module and the second monitoring module.

[0048] In step S3, the first monitoring module continuously monitors the speed of the motor through the speed sensor and sends these data to the control module, and the second monitoring module monitors the real-time current of the motor through the current sensor. The current fluctuates with the change of the motor load, and the current increases when the negative pressure increases. The current change is also sent to the control module in real time. The control module integrates the speed data of the first monitoring module and the current data of the second monitoring module, and obtains the negative pressure value in real time through the negative pressure calculation formula.

[0049] The speed is a direct reflection of the system load. As the negative pressure increases, the motor load increases and the speed decreases. When the speed decreases and the current increases at the same time, it indicates that the negative pressure in the chamber is increasing and the suction resistance is increasing.

[0050] Construction of negative pressure calculation formula: By correlating the negative pressure value (P) in the vacuum chamber with the motor speed (N) and the motor current (I), a negative pressure estimation formula based on the speed and current changes can be constructed.

[0051]

[0052] P: Negative pressure value in the vacuum chamber, indicating the current pressure in the vacuum chamber. The larger the negative pressure value, the higher the vacuum level in the chamber.

[0053] N_0: The weighted average of the initial motor speed, which refers to the motor speed when there is no load (i.e., there is no vacuum in the vacuum chamber or the vacuum resistance is small). This value is used as a benchmark to compare the decrease in motor speed after the negative pressure changes. The weighted average is used to eliminate accidental fluctuations. N: weighted average of the current motor speed Refers to the actual speed of the motor under the current negative pressure state. As the negative pressure in the vacuum chamber increases, the motor needs to overcome more pumping resistance and the speed will decrease. By monitoring the current speed, the negative pressure changes in the chamber can be reflected. Weighted average can filter out the noise caused by instantaneous changes.

[0054] I_0: Weighted average of the motor's initial current The current of the motor under light load or initial state. This value is used as a reference for the current and usually reflects the power consumption of the motor under no negative pressure or light negative pressure.

[0055] I: Weighted average value of the current of the motor The current working current of the motor. As the negative pressure in the vacuum chamber increases, the motor needs more power to overcome the pumping resistance, so the current will rise. This value is time-weighted averaged to eliminate the impact of instantaneous fluctuations and reflect the actual load of the current motor.

[0056] k_1: coefficient related to the speed change This coefficient determines the degree of influence of speed change on the negative pressure value. It is determined by experiments or theoretical derivation and is related to factors such as the structure of the equipment, the size of the vacuum chamber, and the pumping rate. A larger value of k_1 means that the influence of speed change on negative pressure is more significant.

[0057] k_2: coefficient related to current change This coefficient determines the degree of influence of current change on negative pressure. It is usually measured through experiments and reflects the corresponding relationship between current and negative pressure. A larger value of k_2 means that the influence of current change on negative pressure is greater.

[0058] Assume that the following coefficients are obtained through experiments: ( k_1 = 0.7, {Pa / log(speed)}) ( k_2 = 3.5,{Pa / A}) And the initial parameters of the motor are as follows: Initial speed ( N_0 = 1500, {RPM}) Initial current (I_0 = 1.5,{A}) Under the current negative pressure condition, the actual parameters of the motor are measured: Current speed ( N = 1200, {RPM}) Current (I = 2.0,{A}) Use the weighted average method to process the data (here we assume that the weighted average is equal to the current value) and substitute it into the formula:

[0059] First calculate each part: 1. Speed ​​logarithm:

[0060] 2. Current term:

[0061] Final negative pressure value:

[0062] When the speed (N) decreases, it means that the negative pressure in the chamber is increasing because the motor needs to overcome a greater suction resistance. When the current (I) increases, it also means that the negative pressure is increasing, the motor load becomes larger, and more current is required to maintain operation. Through nonlinear functions and time smoothing, the formula can more accurately reflect the change in negative pressure and avoid errors caused by instantaneous fluctuations.

[0063] The control module displays the calculated negative pressure value to the operator through the display module. The display module can be an LCD display or a digital panel, which displays the real-time vacuum chamber pressure in the form of a graph or a numerical value after receiving the data sent by the control module.

[0064] Among them, the graphical display may be displayed in the form of a pressure curve, historical pressure changes, etc. The digital display directly displays the current chamber negative pressure in a specific pressure value (such as Pascal or Torr).

[0065] The control module needs to run a feedback linkage algorithm to make timely adjustments when the negative pressure changes by combining two sets of monitoring data (speed and current). This joint control algorithm is not only used to calculate the current negative pressure value, but also to dynamically adjust the motor current to keep the motor running under a reasonable load.

[0066] During the air extraction process, if the motor speed or current is detected to have changed dramatically, the control module can dynamically adjust the air extraction power (by controlling the current) while calculating the negative pressure value. This process ensures that the air extraction system can maintain a balance between efficiency and safety.

[0067] In order to ensure the accuracy of the system, the first monitoring module and the second monitoring module need to use high-precision sensors and ensure the real-time and accuracy of the data through high-frequency sampling. Once the control module determines that the current negative pressure value has reached or exceeded the preset target value, the control module immediately takes action and sends a command to shut down the motor in the vacuum pump.

[0068] The control module sends a shutdown command to the motor drive module through a digital signal or a communication protocol (such as Modbus, CAN bus, etc.), and the command content is to immediately stop the operation of the motor.

[0069] When the motor receives a stop command, the drive circuit disconnects the power supply and immediately stops the current supply, causing the motor to gradually decelerate until it stops completely.

[0070] When the motor stops, the control module will confirm that the motor has indeed stopped through the system feedback mechanism. This may be confirmed by: Motor speed feedback: The first monitoring module reports that the speed has returned to zero, indicating that the motor has stopped.

[0071] Current feedback: The second monitoring module detects that the motor current is 0, indicating that no current flows into the motor. In some cases, the negative pressure may fluctuate slightly after the motor stops. The control module monitors the period after the stop to confirm that the negative pressure value remains near the target value. If the negative pressure rises beyond the set tolerance, the system may restart the motor for a short period of time until the negative pressure returns to the target range.

[0072] In order to prevent the frequent starting and stopping of the motor from causing equipment wear, the control module designs a time interval mechanism to ensure that the motor does not restart immediately after stopping unless the negative pressure change exceeds the safety threshold.

[0073] If the negative pressure fails to reach the target value as expected (such as equipment failure or external interference), the control module will trigger an alarm to remind the operator to check the equipment or restart the system.

[0074] When the control module detects that the negative pressure value in the vacuum chamber reaches the preset target value, it will calculate the current negative pressure value by linking the data of the first monitoring module and the second monitoring module, and send a command in time to shut down the vacuum pump motor and stop the vacuum operation. This implementation process ensures the efficient operation of the vacuum system, prevents excessive vacuuming, maintains a stable pressure in the chamber, and has a safety protection mechanism to ensure the long-term reliable operation of the equipment.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A negative pressure detection method for a vacuum sealer, characterized in that: Here are the steps: S1: Place the object to be sealed into the vacuum chamber of the vacuum sealer, start the vacuum sealer, and start the vacuum operation; S2: The motor speed is monitored in real time through the first monitoring module. When the negative pressure in the vacuum chamber increases, the air extraction resistance increases and the motor speed decreases; S3: During the vacuuming process, the control module continuously controls the first monitoring module, and collaboratively calculates the negative pressure value in the vacuum chamber based on the numerical change of the motor speed; and displays the real-time chamber pressure through the display module; S4: When the negative pressure value reaches the preset target value, the control module immediately sends a command to turn off the motor in the vacuum pump and stop the vacuum operation; S5: The sealing machine enters a vacuum state and prepares for the next sealing operation.

2. The negative pressure detection method of a vacuum sealer according to claim 1, characterized in that: In step S2, when the speed of the motor is lower than the first preset value, the control module adjusts the current through the regulating module to increase the speed of the motor and restore it to the initial speed of the motor; The motor speed is monitored in real time by the first monitoring module, specifically including: The first monitoring module uses a speed sensor to measure the speed of the motor and capture the speed signal of the motor in real time. The speed sensor converts the speed signal into a digital pulse signal and inputs it into the data acquisition module. The data acquisition module is connected to the control module.

3. The negative pressure detection method of a vacuum sealing machine according to claim 2, characterized in that: In step S2, when the negative pressure of the vacuum chamber increases, the air extraction resistance increases, and the speed of the motor is lower than the first preset value, the control module adjusts the current through the regulating module, specifically including: The first preset value is the minimum speed of the motor under a relatively low load; the algorithm running in the control module compares the speed data collected in real time with the first preset value.

4. The negative pressure detection method of a vacuum sealer according to claim 3, characterized in that: In step S2, it also includes monitoring the motor current through the second monitoring module, and regulating the current through the adjustment module to increase the second preset value, thereby increasing the motor speed and restoring it to the initial motor speed; specifically including: The control module starts the PID controller, which calculates the current increment that needs to be adjusted based on the speed drop. The control module sends instructions to the regulation module based on the output of the PID controller to adjust the input current of the motor.

5. The negative pressure detection method of a vacuum sealer according to claim 4, characterized in that: In step S2, the second monitoring module monitors the working current of the motor in real time through a current sensor; the current sensor is installed on the power line of the motor, and the current sensor converts the detected current signal into a readable voltage signal, and converts it into a digital signal through an analog-to-digital converter (ADC), and transmits it to the control module.

6. The negative pressure detection method of a vacuum sealer according to claim 5, characterized in that: In step S2, the second preset value is adjusted in a range of 0.1A-0.3A.

7. The negative pressure detection method of a vacuum sealer according to claim 6, characterized in that: In step S2, after receiving the instruction from the control module, the regulating module increases the power supply current of the motor through the electronic regulator or the power control module; PWM control increases the current output by adjusting the current duty cycle, thereby increasing the torque of the motor and restoring the speed of the motor.

8. The negative pressure detection method of a vacuum sealer according to claim 1, characterized in that: In step S3, the first monitoring module continuously monitors the speed of the motor through the speed sensor and sends these data to the control module, and the second monitoring module monitors the real-time current of the motor through the current sensor; the current fluctuates as the motor load changes, and the current increases when the negative pressure increases; the current change is also sent to the control module in real time, and the control module integrates the speed data of the first monitoring module and the current data of the second monitoring module, and obtains the negative pressure value in real time through the negative pressure calculation formula.

9. The negative pressure detection method of a vacuum sealer according to claim 1, characterized in that: The negative pressure calculation formula is: , P: negative pressure value in the vacuum chamber, indicating the current pressure in the vacuum chamber, N_0: weighted average value of the initial speed of the motor, N: weighted average value of the current speed of the motor, I_0: weighted average value of the initial current of the motor, I: weighted average value of the current current of the motor, k_1: coefficient related to the speed change, k_2: coefficient related to the current change.

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