Vacuum sealing equipment and method capable of adapting to high-altitude environment

Abstract

The invention provides vacuum sealing equipment capable of adapting to a high-altitude environment, which comprises a sealing machine body provided with a vacuum chamber and a vacuum module comprising a vacuum pump communicated with the vacuum chamber, the vacuum pump comprises a driving motor, and the driving motor drives the sealing machine body to rotate. The driving motor is used for driving the vacuum pump to vacuumize an object to be sealed in the vacuum chamber; the control module comprises a control unit and a rotating speed detection unit electrically connected with the control unit, the rotating speed detection unit calculates the real-time rotating speed of the driving motor based on the pulse signal time, and the control unit is used for judging the vacuum degree condition in the vacuum chamber according to the real-time rotating speed of the driving motor. And the vacuumizing time of the vacuum pump is timely adjusted.

Description

Technical Field

[0001] The present invention relates to a vacuum sealing device and method adaptable to high altitude environments, and is applied to the field of vacuum sealing. Background Art

[0002] A vacuum sealer is a device used for vacuum packaging items. It can automatically complete operations such as evacuating air from the packaging bag and sealing, effectively maintaining the freshness of the items, preventing oxidation and spoilage.

[0003] Existing vacuum sealers generally use mechanical pressure sensors or digital pressure sensors, which can accurately measure the pressure in the vacuum chamber. However, the atmospheric pressure is relatively low in high altitude areas, and the pressure difference between the external air pressure and the air pressure in the vacuum chamber is large. Therefore, using traditional pressure sensors will result in large measurement errors, and further lead to the situation that the vacuum sealer fails to fully evacuate the air when working in high altitude areas. In view of the above problems, the present invention designs a vacuum sealing device and method adaptable to high altitude environments. Summary of the Invention

[0004] The present invention provides a vacuum sealing device and method adaptable to high altitude environments, which can effectively solve the above problems.

[0005] The present invention is implemented as follows: A vacuum sealing device adaptable to high altitude environments includes: A sealer body having a vacuum chamber, and A vacuum module including a vacuum pump communicated with the vacuum chamber. The vacuum pump includes a driving motor, and the driving motor is used to drive the vacuum pump to perform a vacuum pumping operation on the items to be sealed disposed in the vacuum chamber; A control module including a control unit and a rotation speed detection unit electrically connected to the control unit. The rotation speed detection unit calculates the real-time rotation speed of the driving motor based on the pulse signal time, and the control unit is used to judge the vacuum degree situation in the vacuum chamber according to the real-time rotation speed of the driving motor and timely adjust the vacuum pumping time of the vacuum pump.

[0006] As a further improvement, the rotation speed detection unit is a Hall sensor, a permanent magnet is installed on the rotating part of the driving motor, and the distance between the permanent magnet and the Hall sensor is 1 - 5 mm.

[0007] As a further improvement, the control module further includes a pressure sensing unit installed in the vacuum chamber. The pressure sensor is electrically connected to the control unit. The pressure sensing unit is a digital pressure sensor, and the digital pressure sensor is used to detect the pressure value in the vacuum chamber.

[0008] As a further improvement, the control module further includes a temperature sensing unit installed in the vacuum chamber, and the temperature sensing unit is used to detect the temperature in the vacuum chamber.

[0009] As a further improvement, it further includes a bag mouth heat sealing module, and the bag mouth heat sealing module is used to seal the item to be sealed.

[0010] A vacuum sealing method adaptable to high altitude environments includes the following steps: S1: The control unit initializes and loads the vacuum degree - rotation speed calibration curve under standard atmospheric pressure; S2: Place the item to be sealed into the vacuum chamber of the vacuum sealing device, preset the vacuum pumping time, and start the vacuum sealing device to start the vacuum pumping operation; S3: The rotation speed monitoring unit monitors the motor rotation speed in real time, compares the real - time monitored rotation speed of the driving motor with the vacuum degree - rotation speed calibration curve, and determines whether the target vacuum degree is reached; S4: If the real - time monitored rotation speed of the driving motor fits the vacuum degree - rotation speed calibration curve, it is determined that the target vacuum degree is reached. After the preset vacuum pumping time, stop the vacuum pumping operation. If there is a deviation between the real - time monitored rotation speed of the driving motor and the vacuum degree - rotation speed calibration curve, it is determined that the target vacuum degree is not reached, and extend the vacuum pumping time until it fits and then stop the vacuum pumping operation.

[0011] As a further improvement, the vacuum degree - rotation speed calibration curve is N(P)= · , where, is the no - load rotation speed, is the air extraction resistance coefficient, is the load characteristic coefficient, and P is the absolute pressure value.

[0012] As a further improvement, comparing the real - time monitored rotation speed of the driving motor with the vacuum degree - rotation speed calibration curve to determine whether the target vacuum degree is reached further includes: S31: Calibrate the vacuum degree - rotation speed calibration curve through the pressure sensing unit and the temperature sensing unit.

[0013] As a further improvement, calibrating the vacuum degree - rotation speed calibration curve through the pressure sensing unit and the temperature sensing unit includes: S311: The control unit synchronously collects the real - time rotation speed, absolute pressure value, and temperature data of the driving motor; S312: Filter out the noise from the real - time rotation speed, absolute pressure value, and temperature data of the driving motor: S313: Use the nonlinear least - squares method to update the calibration curve parameters in real time, including the following steps: = ( ) Wherein: = is the parameter vector; = is the regression vector, is the actual measured value of the parameter, is the Kalman gain matrix; S314: Add a temperature compensation term to the calibration curve to correct the temperature drift of the pressure sensor and the motor efficiency: ·

[0014] Wherein: is the reference temperature; is the temperature coefficient; S315: Calculate the mean absolute error (MEA) and the coefficient of determination ( ), and make a judgment according to the qualified standard: Mean absolute error: MEA= ; Coefficient of determination: =1

[0015] The qualified standard is MEA < 50 RPM, > 0.95.

[0016] As a further improvement, the vacuum sealing method further includes: S5: Heat-seal the article to be tested through the bag mouth heat-sealing module.

[0017] The beneficial effects of the present invention are: (1) By monitoring the real-time speed of the drive motor through the control module and judging the negative pressure situation in the vacuum chamber according to the real-time speed of the drive motor, and dynamically adjusting the vacuum pumping time, the present invention solves the measurement error problem of the traditional pressure sensor caused by low air pressure at high altitudes.

[0018] (2) The vacuum degree - rotation speed calibration curve under standard atmospheric pressure is obtained through experiments. The actual rotation speed of the drive motor is detected by the rotation speed detection unit. By comparing the real - time monitored rotation speed of the drive motor with the vacuum degree - rotation speed calibration curve, it is judged whether the target vacuum degree is reached. If the real - time monitored rotation speed of the drive motor fits the vacuum degree - rotation speed calibration curve, it is determined that the target vacuum degree is reached, and the vacuum pumping operation is stopped after a preset vacuum pumping time. If there is a deviation between the real - time monitored rotation speed of the drive motor and the vacuum degree - rotation speed calibration curve, it is determined that the target vacuum degree is not up to standard, and the vacuum pumping time is extended until the fitting is completed and then the vacuum pumping operation is stopped. Through this method, the vacuum state in the vacuum chamber can be accurately obtained, and further, the vacuum sealer can completely evacuate the items to be sealed.

[0019] (3) Since the vacuum degree - rotation speed calibration curve is affected by manufacturing tolerances, mechanical wear, and environmental changes, which may lead to errors, the pressure value and temperature value in the vacuum chamber are detected by the pressure sensing unit and the temperature sensing unit. The calibration curve parameters are updated in real - time using the non - linear least - squares method, and the mean absolute error (MEA) and the coefficient of determination ( ) are calculated, and the inspection is carried out according to the qualified standard. Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0021] Figure 1 is the structural schematic diagram provided by the embodiment of the present invention.

[0022] Figure 2 is the installation structural schematic diagram of the pressure sensing unit and the temperature sensing unit provided by the embodiment of the present invention.

[0023] Figure 3 is the structural decomposition schematic diagram provided by the embodiment of the present invention.

[0024] Figure 4 is the flow chart provided by the embodiment of the present invention.

[0025] The reference signs in the drawings are as follows: 10, sealer body; 11, upper cover; 12, fuselage; 13, vacuum chamber; 20, vacuum module; 21, vacuum pump; 22, drive motor; 30, control module; 31, control unit; 32, rotation speed detection unit; 33, pressure sensing unit; 34, temperature sensing unit; 40. Bag mouth heat-sealing module. Specific embodiments

[0026] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0028] Refer to Figures 1 - 3 As shown, a vacuum sealing device adaptable to high-altitude environments includes: a sealing machine body 10, including an upper cover 11 and a fuselage 12. When the upper cover 11 and the fuselage 12 are fastened, there is a vacuum chamber 13, and a vacuum module 20, including a vacuum pump 21 communicating with the vacuum chamber 13. The vacuum pump 21 includes a drive motor 22, and the drive motor 22 is used to drive the vacuum pump 21 to perform a vacuum pumping operation on the articles to be sealed disposed in the vacuum chamber 13. It further includes a bag mouth heat-sealing module 40, which is used to seal the articles to be sealed after the vacuum pumping operation; A control module 30, including a control unit 31 and a rotational speed detection unit 32 electrically connected to the control unit 31. The rotational speed detection unit 32 calculates the real-time rotational speed of the drive motor 22 based on the pulse signal time, and the control unit 31 is used to judge the vacuum degree in the vacuum chamber 13 according to the real-time rotational speed of the drive motor 22 and timely adjust the vacuum pumping time of the vacuum pump 21.

[0029] The rotational speed detection unit 32 is a Hall sensor. A permanent magnet is installed on the rotating part of the drive motor 22. A permanent magnet (such as a neodymium magnet) is installed on the rotating part (such as the shaft or coupling) of the drive motor 22 to ensure that a fixed number of magnetic field changes are generated per revolution. The distance between the permanent magnet and the Hall sensor is 1 - 5 mm. In this embodiment, a switch-type Hall sensor (such as A3144) is fixed at a position close to the magnet, and the distance is controlled within 1 - 5 mm to ensure that the magnetic field change can be reliably detected. The Hall sensor outputs a pulse signal, and the control unit 31 (MCU) captures the time interval of the pulse rising edge. The calculation formula is: Rotational speed (RPM) =

[0030] As a further improvement, the control module 30 further includes a pressure sensing unit 33 installed in the vacuum chamber 13. The pressure sensor is electrically connected to the control unit 31. The pressure sensing unit 33 is a digital pressure sensor, and the digital pressure sensor is used to detect the pressure value in the vacuum chamber 13. The control module 30 further includes a temperature sensing unit 34 installed in the vacuum chamber 13, and the temperature sensing unit 34 is used to detect the temperature in the vacuum chamber 13.

[0031] Referring to Figure 4 shown, a vacuum sealing method adaptable to high altitude environments includes the following steps: S1: The control unit 31 initializes and loads the vacuum degree - rotational speed calibration curve under standard atmospheric pressure; S2: Place the item to be sealed into the vacuum chamber 13 of the vacuum sealing device, preset the vacuum pumping time, and start the vacuum sealing device to start the vacuum pumping operation; S3: Real-time monitor the motor speed through the rotational speed monitoring unit, compare the real-time monitored rotational speed of the drive motor 22 with the vacuum degree - rotational speed calibration curve, and determine whether the target vacuum degree is reached; S4: If the real-time monitored rotational speed of the drive motor 22 fits the vacuum degree - rotational speed calibration curve, it is determined that the target vacuum degree is reached, and the vacuum pumping operation is stopped after the preset vacuum pumping time. If there is a deviation in the fitting of the real-time monitored rotational speed of the drive motor 22 and the vacuum degree - rotational speed calibration curve, it is determined that the target vacuum degree is not reached, and the vacuum pumping time is extended until the fitting is completed and then the vacuum pumping operation is stopped; S5: Heat-seal the item to be tested through the bag mouth heat-sealing module 40.

[0032] In one embodiment, the vacuum degree - rotational speed calibration curve is N(P) = · , where is the no-load rotational speed, is the air extraction resistance coefficient, is the load characteristic coefficient, and P is the absolute pressure value. Since the load of the vacuum pump is inversely proportional to the absolute pressure P in the vacuum chamber. When the vacuum degree increases (P decreases), the gas molecular density decreases, but the turbulence effect and molecular flow resistance increase, resulting in an increase in the motor load and a decrease in the rotational speed N. Therefore, the relationship between the vacuum degree - rotational speed calibration curve is verified through experiments: In this experiment, a vacuum pump with an ultimate vacuum of 0.1 KPa is used, a brushless DC motor with a rated speed of 3000 RPM is used, a Hall sensor of model Allegro A3144 is used, a digital pressure sensor of model Bosch BMP388 (range 0 - 110 kPa) is used, and a temperature sensor of model DS18B20 (-55°C ~ 125°C) is used. First, at standard atmospheric pressure (101.3 kPa), the no-load rotational speed of the motor is recorded , and the vacuum is gradually pumped down to the ultimate pressure (such as 1 kPa) to obtain the following data: Table 1 Absolute Pressure - Measured Rotational Speed Data

[0033] Then, through the linear least squares method for fitting judgment, the sum of the squared residuals between the model predicted value and the measured value is minimized:

[0034] The optimized parameters are = 2980.5 RPM, = 25320.3, = 115.2, α = 0.068 The obtained vacuum degree - rotational speed calibration curve is: N(P) = ·

[0035] The goodness of fit is judged by the coefficient of determination ( ): = 0.992 > 0.95. Therefore, this curve conforms to the functional relationship between the vacuum degree and the real-time rotational speed under standard atmospheric pressure.

[0036] Since the vacuum degree - rotational speed calibration curve is affected by manufacturing tolerances, mechanical wear, and environmental changes, which may lead to errors, the pressure value and temperature value in the vacuum chamber 13 are detected through the pressure sensing unit 33 and the temperature sensing unit 34. The calibration curve parameters are updated in real time using the nonlinear least squares method, and the mean absolute error (MEA) and the coefficient of determination () are calculated, and the inspection is carried out according to the qualified standard. The operation steps are as follows: S31: Calibrate the vacuum degree - rotational speed calibration curve through the pressure sensing unit 33 and the temperature sensing unit 34.

[0037] As a further improvement, calibrating the vacuum degree - rotational speed calibration curve through the pressure sensing unit 33 and the temperature sensing unit 34 includes: S311: The control unit 31 synchronously collects the real - time rotational speed, absolute pressure value, and temperature data of the drive motor 22; S312: Filter out the noise from the real - time rotational speed, absolute pressure value, and temperature data of the drive motor 22: S313: Use the non - linear least - squares method to update the calibration curve parameters in real - time, including the following steps: = ( ) Where: = is the parameter vector; = is the regression vector, is the actual measured value of the parameter, is the Kalman gain matrix; S314: Add a temperature compensation term to the calibration curve to correct the temperature drift of the pressure sensor and the motor efficiency: ·

[0038] Where: is the reference temperature; is the temperature coefficient; S315: Calculate the mean absolute error (MEA) and the coefficient of determination ( ), and make a judgment according to the qualified standard: Mean absolute error: MEA = ; Coefficient of determination: = 1

[0039] The qualified standard is MEA < 50 RPM, > 0.95.

[0040] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A vacuum sealing device adaptable to high altitude environments, characterized in that, Comprising: A sealing machine body, having a vacuum chamber, and A vacuum module, including a vacuum pump communicating with the vacuum chamber, the vacuum pump including a drive motor for driving the vacuum pump to perform a vacuuming operation on the articles to be sealed disposed in the vacuum chamber; A control module, including a control unit and a rotational speed detection unit electrically connected to the control unit, the rotational speed detection unit calculating the real-time rotational speed of the drive motor based on the pulse signal time, and the control unit being used for judging the vacuum degree condition in the vacuum chamber according to the real-time rotational speed of the drive motor and timely adjusting the vacuuming time of the vacuum pump.

2. The vacuum sealing device adaptable to high altitude environments according to claim 1, wherein The rotational speed detection unit is a Hall sensor, and a permanent magnet is installed on the rotating part of the drive motor, and the distance between the permanent magnet and the Hall sensor is 1-5 mm.

3. A vacuum sealing device adaptable to high altitude environments according to claim 2, characterized in that, The control module further includes a pressure sensing unit installed in the vacuum chamber, the pressure sensor being electrically connected to the control unit, the pressure sensing unit being a digital pressure sensor for detecting the pressure value in the vacuum chamber.

4. A vacuum sealing device adaptable to high altitude environments according to claim 3, characterized in that, The control module further includes a temperature sensing unit installed in the vacuum chamber, the temperature sensing unit being used for detecting the temperature in the vacuum chamber.

5. The vacuum sealing device adaptable to high altitude environments according to claim 4, characterized in that, Further comprising a bag mouth heat sealing module for sealing the articles to be sealed.

6. A vacuum sealing method adaptable to high altitude environments, comprising a vacuum sealing device adaptable to high altitude environments as described in claim 5, characterized in that, Including the following steps: S1: The control unit initializes and loads the vacuum degree - rotational speed calibration curve under standard atmospheric pressure; S2: Place the articles to be sealed into the vacuum chamber of the vacuum sealing device, preset the vacuuming time, and start the vacuum sealing device to start the vacuuming operation; S3: Real-time monitor the rotational speed of the motor through the rotational speed monitoring unit, compare the real-time monitored rotational speed of the drive motor with the vacuum degree - rotational speed calibration curve, and judge whether the target vacuum degree is reached; S4: If the real-time monitored rotational speed of the drive motor fits the vacuum degree - rotational speed calibration curve, it is determined that the target vacuum degree is reached, and the vacuuming operation is stopped after the preset vacuuming time. If there is a deviation between the real-time monitored rotational speed of the drive motor and the vacuum degree - rotational speed calibration curve fitting, it is determined that the target vacuum degree is not reached, and the vacuuming time is extended until the fitting and then the vacuuming operation is stopped.

7. A vacuum sealing method adaptable to high altitude environments according to claim 6, characterized in that, The vacuum degree - rotation speed calibration curve is N(P) = · , where is the no - load rotation speed, is the air extraction resistance coefficient, is the load characteristic coefficient, and P is the absolute pressure value.

8. A vacuum sealing method adaptable to high altitude environments according to claim 7, characterized in that, Comparing the real-time monitored rotational speed of the drive motor with the vacuum degree - rotational speed calibration curve and judging whether the target vacuum degree is reached further includes: S31: Calibrate the vacuum degree - rotational speed calibration curve through the pressure sensing unit and the temperature sensing unit.

9. A vacuum sealing method adaptable to high altitude environments according to claim 8, characterized in that, Calibrating the vacuum degree - rotational speed calibration curve through the pressure sensing unit and the temperature sensing unit includes: S311: Synchronously collect the real-time rotational speed of the drive motor, the absolute pressure value, and the temperature data through the control unit; S312: Filter the noise of the real-time rotational speed of the drive motor, the absolute pressure value, and the temperature data; S313: Use the nonlinear least squares method to update the calibration curve parameters in real time, including the following steps: = （ ） Wherein: = is the parameter vector; = is the regression vector, is the actual measured value of the parameter, is the Kalman gain matrix; S314: Add a temperature compensation term to the calibration curve to correct the temperature drift of the pressure sensor and the motor efficiency; · Wherein: is the reference temperature; is the temperature coefficient; S315: Calculate the mean absolute error (MEA) and the coefficient of determination ( ), and make a judgment according to the qualified standard: Mean absolute error: MEA= ; Coefficient of determination: =1 Qualified standard: MEA < 50 RPM, > 0.

95.

10. A vacuum sealing method adaptable to high altitude environments according to claim 6, characterized in that, The vacuum sealing method further includes: S5: Heat-seal the articles to be tested through the bag mouth heat sealing module.

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