A pump and valve integrated machine that can actively regulate pressure

Abstract

This application discloses an integrated pump and valve unit capable of actively adjusting pressure, relating to the field of air pump and valve technology. It includes a monitoring component, a diaphragm air pump, a motor, and an outlet adapter and a pressure regulating solenoid valve arranged parallel to each other at the outlet end of the diaphragm air pump. The bottom of the pressure regulating solenoid valve is connected to the pressure relief slot of the diaphragm air pump. A stationary iron core and a moving iron core are axially arranged on the inner side of the valve tube of the pressure regulating solenoid valve, connected by a spring. A coil for driving the moving iron core is provided on the outer side of the pressure regulating solenoid valve. The technical advantages of this application are: by integrating the pressure regulating solenoid valve, pressure sensor, and outlet adapter, the pressure sensor selects the pressure adjustment period, and the solenoid valve intervenes during the pressure adjustment period to achieve selective pressure relief of the diaphragm air pump; through the combined arrangement of the stationary iron core, moving iron core, and spring, and utilizing the electromagnetic drive of the coil, the stationary iron core dynamically seals the pressure relief circuit of the pressure relief slot, which can block backflow and complete pressure stabilization and boosting when the air pump outlet pressure is insufficient.

Description

Technical Field

[0001] This application relates to the field of air pump valve technology, and in particular to a pump valve integrated machine that can actively adjust pressure. Background Technology

[0002] Diaphragm air pumps, as a commonly used positive displacement pneumatic conveying device, rely on the reciprocating deformation of the diaphragm to change the internal volume of the cavity. With the help of inlet and outlet check valves, they can realize the continuous intake and pressurized discharge of gas. They are compact in structure, stable in operation, and highly adaptable. They are widely used in gas turbine supporting pneumatic control, industrial automation pneumatic circuits, fluid pressurization and conveying, etc., to meet the needs of various equipment for stable gas supply and pressure regulation.

[0003] Patent application number CN201821781378.X discloses an electric air pump with a pressure relief mechanism. The outer casing is equipped with a pressure relief mechanism, which includes a pressure relief port and a pressure relief valve located on the pressure relief port. When the internal air pressure value of the outer casing is greater than a certain air pressure value, the internal air pressure pushes the pressure relief valve outward to open the pressure relief port and release the internal gas from the pressure relief port. However, the pressure relief mechanism has a single control method, and the solenoid valve is a simple on / off control, which does not have the ability to selectively and segmentedly relieve pressure. The pressure setting mode is fixed and cannot achieve controllable selective pressure relief based on dynamic pressure. Summary of the Invention

[0004] This device provides a pump and valve integrated unit that can actively adjust pressure, and the specific implementation method is as follows: A pump and valve integrated machine capable of actively regulating pressure includes: Diaphragm air pump and motor for driving the diaphragm air pump; An outlet adapter and a pressure regulating solenoid valve are arranged side by side at the outlet end of the diaphragm air pump. The bottom of the pressure regulating solenoid valve is connected to the pressure relief slot of the diaphragm air pump. The pressure regulating solenoid valve has a stationary iron core and a moving iron core axially arranged on the inner side of the valve tube, which are connected by a spring. The outer side of the pressure regulating solenoid valve has a coil for driving the moving iron core to make axial displacement. The monitoring component, whose pressure sensor probe is inserted into the inside of the outlet adapter, is used to monitor the insufficient outlet pressure of the diaphragm air pump. When the outlet pressure is insufficient, the coil is energized and drives the stationary iron core to move down and block the return channel of the pressure relief slot, so as to achieve system pressure increase; When the outlet pressure reaches the standard, the coil is de-energized, the moving iron core is reset, and the stationary iron core works in conjunction with the spring to perform normal pressure relief on the return channel of the pressure relief slot.

[0005] Based on the above technical solution, the pressure relief slot is a tubular structure, and its opening is engaged with the yoke of the pressure regulating solenoid valve. The coil of the pressure regulating solenoid valve is controlled by the control board. The pressure regulating solenoid valve, pressure sensor and air outlet adapter are integrated and arranged. The pressure sensor selects the pressure adjustment period. The solenoid valve intervenes during the pressure adjustment period to achieve selective pressure relief of the diaphragm air pump. The coil enables the static iron core to dynamically block the pressure relief circuit in the pressure relief slot, which can increase the pressure when the air pump outlet pressure is insufficient. In the initial stage of operation, the diaphragm air pump is filled with air through airflow. During the filling process, the coil of the pressure regulating solenoid valve is not energized, and the pressure gradually increases. When the pressure exceeds the pressure that the spring can withstand, the stationary iron core of the pressure regulating solenoid valve rises, and the gas enters the pressure relief outlet from the pressure relief inlet to stabilize the pressure of the diaphragm air pump. When the pressure sensor detects the internal pressure value of the outlet adapter, it energizes the coil of the pressure regulating solenoid valve. The moving iron core moves downward and attracts the stationary iron core, generating downward pressure. The pressure relief outlet is blocked by the stationary iron core of the pressure regulating solenoid valve, and the diaphragm air pump cannot relieve pressure, thus achieving the function of stabilizing and increasing the pressure of the diaphragm air pump.

[0006] Preferably, the monitoring component is fixedly installed on the side of the air outlet adapter, and it also includes a control board electrically connected to the pressure sensor.

[0007] Preferably, the upper and lower ends of the valve tube are respectively provided with a first mounting plate and a second mounting plate, and the coil is wrapped around the outside of the valve tube, with its two ends abutting against the first mounting plate and the second mounting plate respectively.

[0008] Preferably, the first mounting plate and the second mounting plate are connected to the control plate via a C-shaped bracket, and the control plate is clamped and limited between the C-shaped bracket and the air outlet adapter.

[0009] Preferably, the pressure relief slot is provided with a pressure relief inlet and a pressure relief outlet in parallel, with one end of the two connected to the air delivery chamber of the diaphragm air pump, and the other end of the two connected to the bottom of the valve pipe.

[0010] Preferably, the first mounting plate and the second mounting plate are connected to the C-shaped bracket via pins.

[0011] Preferably, the bottom of the stationary iron core is provided with a plug that is crimped to cover the pressure relief inlet and pressure relief outlet.

[0012] Based on the above technical solution, the C-shaped bracket and the control board can be welded together, and a pressure sensor can be welded to the other side of the control board. Through the linkage between the control board, the pressure sensor, and the solenoid valve, when the coil is not energized, the pressure relief effect of the air delivery chamber is achieved by means of the elasticity of the static iron core and the spring. The pressure sensor can be used to set the pressure trigger value and select the pressure relief pressure.

[0013] Preferably, the diaphragm air pump includes a power chamber and an air delivery chamber; the top of the air delivery chamber is provided with an air outlet connected to the air outlet adapter, and the air delivery chamber is provided with an air inlet pipe connected downwards.

[0014] Preferably, the power chamber is provided with a piston port that communicates with the air supply chamber, and a piston is provided on the piston port; the motor is axially located at the bottom of the power chamber, and its output end is provided with an eccentric wheel, which is connected to the piston through a swing arm.

[0015] Based on the above technical solution, the motor at the bottom of the air pump is a brushed motor, the air inlet pipe is arranged parallel to the diaphragm air pump, and the inlet of the air inlet pipe is located at the tail of the diaphragm air pump.

[0016] In summary, this application includes the following beneficial technical effects: 1. This invention integrates a pressure regulating solenoid valve, a pressure sensor, and an outlet adapter. By using the pressure sensor to select the pressure adjustment period, the solenoid valve intervenes during the pressure adjustment period to achieve selective pressure relief of the diaphragm air pump. 2. This invention achieves automatic pressure relief of the air delivery chamber by means of the coordinated operation of the control board, pressure sensor and solenoid valve, when the coil is not energized, relying on the elastic action of the stationary iron core and spring; at the same time, the pressure sensor can be used to customize the pressure trigger threshold, so as to achieve flexible selection of the pressure relief pressure. 3. The present invention has a simple structure. By combining a stationary iron core, a moving iron core and a spring, and using the electromagnetic drive of the coil, the stationary iron core dynamically blocks the pressure relief circuit of the pressure relief slot. This can block backflow and achieve pressure stabilization and boosting when the air pump outlet pressure is insufficient. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a front view structural diagram of the present invention; Figure 3 This is an exploded structural diagram of the present invention; Figure 4 This is a schematic diagram of the pressure regulating solenoid valve in this invention. Figure 1 ; Figure 5 This is a cross-sectional view of the pressure regulating solenoid valve in this invention. Figure 1 ; Figure 6 This is a schematic diagram of the pressure regulating solenoid valve in this invention. Figure 2 ; Figure 7 This is a schematic diagram of the pressure regulating solenoid valve in this invention. Figure 3 ; Figure 8 This is an exploded structural diagram of the pressure regulating solenoid valve in this invention; Figure 9 This is a schematic diagram of the pressure regulating solenoid valve in this invention. Figure 4 ; Figure 10 This is a cross-sectional schematic diagram of the diaphragm air pump structure in this invention. Figure 1 ; Figure 11 This is a cross-sectional schematic diagram of the diaphragm air pump structure in this invention. Figure 2 ; Figure 12 This is a cross-sectional view of the pressure regulating solenoid valve in this invention. Figure 2 ; Figure 13 This is a schematic diagram of the structure when the present invention is applied.

[0018] Explanation of reference numerals in the attached figures: 1. Motor; 2. Diaphragm air pump; 3. Air outlet adapter; 4. Pressure regulating solenoid valve; 5. Monitoring component; 6. C-shaped bracket; 7. Eccentric wheel; 8. Swing arm; 9. Piston; 10. Mounting bracket; 11. Air tube; 12. Airbag. 201. Air outlet; 202. Pressure relief groove; 203. Power chamber; 204. Piston port; 205. Air inlet pipe; 206. Air delivery chamber. 2021, pressure relief inlet; 2022, pressure relief outlet. 401. First mounting plate; 402. Pin; 403. Valve pipe; 404. Coil; 405. Plug; 406. Second mounting plate; 407. Stationary iron core; 408. Moving iron core; 409. Spring. 501. Control board; 502. Pressure sensor. Detailed Implementation

[0019] The specific embodiments of the present invention are described below with reference to the accompanying drawings and examples: It should be noted that the structures, proportions, sizes, etc. illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification, so that those skilled in the art can understand and read them, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0020] Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0021] The following is in conjunction with the appendix Figure 1-13 This application will be described in further detail.

[0022] This application discloses a pump and valve integrated machine that can actively adjust pressure.

[0023] Example 1

[0024] Reference Figures 1 to 12 This embodiment discloses a pump and valve integrated machine that can actively adjust pressure, including a monitoring component 5, an air outlet adapter 3, a pressure regulating solenoid valve 4, a diaphragm air pump 2, and a motor 1 for driving the diaphragm air pump 2. The air outlet adapter 3 and the pressure regulating solenoid valve 4 are arranged side by side at the air outlet end of the diaphragm air pump 2, and the bottom of the pressure regulating solenoid valve 4 is connected to the pressure relief slot 202 of the diaphragm air pump 2.

[0025] Reference Figures 6 to 8 and Figure 12 The pressure regulating solenoid valve 4 has a stationary iron core 407 and a moving iron core 408 axially arranged on the inner side of the valve pipe 403, which are connected by a spring 409. A coil 404 is provided on the outer side of the pressure regulating solenoid valve 4 to drive the moving iron core 408 to axial displacement. When the outlet pressure is insufficient, the coil 404 is energized, causing the stationary iron core 407 to move downwards and block the return flow channel of the pressure relief slot 202, thereby increasing the system pressure. When the outlet pressure reaches the target, the coil 404 is de-energized, the moving iron core 408 returns to its original position, and the stationary iron core 407, in conjunction with the spring 409, performs normal pressure relief on the return flow channel of the pressure relief slot 202. When the coil 404 is energized, the downward electromagnetic attraction force on the moving iron core 408 is greater than the restoring force of the spring 409.

[0026] Reference Figures 2 to 8 The probe end of the pressure sensor 502 in the monitoring component 5 is inserted into the inside of the air outlet adapter 3. The monitoring component 5 is used to monitor the insufficient air outlet pressure of the diaphragm air pump 2. In this structure, the monitoring component 5 is fixedly installed on the side of the air outlet adapter 3. It also includes a control board 501. The signal input terminal of the control board 501 is electrically connected to the pressure sensor 502, and the signal output terminal of the control board 501 is electrically connected to the motor 1 and the coil 404.

[0027] Reference Figures 6 to 9 The valve tube 403 has a first mounting plate 401 and a second mounting plate 406 at its upper and lower ends, respectively. The coil 404 is arranged around the outside of the valve tube 403, and its two ends abut against the first mounting plate 401 and the second mounting plate 406, respectively. In this structure, the first mounting plate 401 and the second mounting plate 406 are connected to the control plate 501 through the C-shaped bracket 6, and the control plate 501 is clamped and limited between the C-shaped bracket 6 and the air outlet adapter 3. In this structure, the first mounting plate 401 and the second mounting plate 406 are connected to the C-shaped bracket 6 through the pin 402.

[0028] Example 2

[0029] Reference Figures 1 to 11This embodiment discloses a pump and valve integrated machine that can actively adjust pressure, including a monitoring component 5, an air outlet adapter 3, a pressure regulating solenoid valve 4, a diaphragm air pump 2, and a motor 1; the air outlet adapter 3 and the pressure regulating solenoid valve 4 are arranged side by side at the air outlet end of the diaphragm air pump 2, and the bottom of the pressure regulating solenoid valve 4 is connected to the pressure relief slot 202 of the diaphragm air pump 2. In this structure, the monitoring component 5, the air outlet adapter 3, and the pressure regulating solenoid valve 4 are integrated into one unit, and the diaphragm air pump 2 includes a power chamber 203 and an air delivery chamber 206; The top of the air supply chamber 206 is provided with an air outlet 201 connected to the air outlet adapter 3, and the air supply chamber 206 is connected to the air inlet pipe 205 downward. In this structure, the pressure relief slot 202 is provided with a pressure relief inlet 2021 and a pressure relief outlet 2022 in parallel, and one end of the two is connected to the air supply chamber 206 of the diaphragm air pump 2, and the other end of the two is connected to the bottom of the valve pipe 403; the bottom of the stationary iron core 407 is provided with a plug 405 that is pressed and covers the pressure relief inlet 2021 and the pressure relief outlet 2022.

[0030] Reference Figures 10 to 11 The power chamber 203 is provided with a piston port 204 communicating with the air supply chamber 206. An intake valve is provided between the air supply chamber 206 and the intake pipe 205, and an exhaust valve is provided between the air supply chamber 206 and the exhaust port 201. A piston 9 is provided on the piston port 204. The motor 1 is axially located at the bottom of the power chamber 203, and its output end is provided with an eccentric wheel 7. The eccentric wheel 7 is linked to the piston 9 through a swing arm 8. A stationary iron core 407 is axially provided on the inner side of the valve tube 403 of the pressure regulating solenoid valve 4. The moving iron core 408 and the moving iron core 408 are connected by a spring 409. The outer side of the pressure regulating solenoid valve 4 is provided with a coil 404 for driving the moving iron core 408 to make axial displacement. In this structure, the motor 1 drives the eccentric wheel 7 to rotate. The eccentric wheel 7 drives the piston 9 to reciprocate at the piston port 204 through the swing arm 8. When the swing arm 8 drives the piston 9 to move downward, the intake valve plate opens and the exhaust valve plate closes. When the swing arm 8 drives the piston 9 to move upward, the intake valve plate closes and the exhaust valve plate opens.

[0031] The specific implementation process is as follows: when the motor 1 is turned on, the air delivery chamber 206 of the diaphragm air pump 2 performs air delivery operation; the external airflow enters the air delivery chamber 206 through the air inlet pipe 205, and then inflates the outside through the air outlet 201 and the air outlet adapter 3. During this period, coil 404 is not energized. As the pressure in gas delivery chamber 206 gradually increases, exceeding the elastic force of spring 409, stationary iron core 407 is lifted upward, and gas is depressurized from the return channel of pressure relief slot 202, thereby stabilizing the pressure of diaphragm air pump 2. When the pressure sensor 502 detects insufficient pressure in the outlet adapter 3, the coil 404 is energized, and the moving iron core 408 is pressed axially downward. At the same time, the moving iron core 408 causes the stationary iron core 407 to be forcibly pressed down to block the return channel of the pressure relief slot 202, and pressure relief is no longer carried out. The gas is pressurized in the gas delivery chamber 206, and the outlet pressure continues to rise. The outlet pressure changes according to the energization time of the coil 404. The longer the energization time, the higher the outlet pressure. Once the pressure sensor 502 detects that the pressure inside the air outlet adapter 3 has stabilized, the coil 404 is de-energized, the moving iron core 408 is reset, and the spring 409 and the stationary iron core 407 continue to perform the pressure relief operation in the return channel of the pressure relief slot 202.

[0032] Example 3

[0033] Reference Figures 1 to 13 Based on the above embodiments, this embodiment discloses a pump and valve integrated machine that can actively adjust pressure. The pump and valve integrated machine is applied to the air inlet of a massage waist support and also includes a mounting bracket 10. Several airbags 12 are arranged in a matrix on the mounting bracket 10, and each airbag 12 is connected to the air outlet adapter 3 through an air pipe 11.

[0034] Example 4

[0035] Reference Figures 1 to 13 Based on the above embodiments, this embodiment discloses a self-testing method for a pump-valve integrated machine capable of actively adjusting pressure, the specific steps of which are as follows: S100. Self-check whether the pressure sensor 502 is inaccurate by recording time. Under the premise that the coil 404 is not energized and the pressure regulating solenoid valve 4 is under normal pressure relief, record the running time of the diaphragm air pump 2 until the air outlet adapter 3 reaches the first pressure output value of 45Kpa in 10 seconds. S200 and coil 404 are not energized. Diaphragm air pump 2 starts running. The actual running time for air outlet adapter 3 to reach the first pressure output value of 45 kPa is recorded as 9.9 seconds. Comparing 9.9 seconds with 10 seconds, there is a time difference of 0.1 seconds. This is within the allowable error range of ±0.1 seconds, which proves that pressure sensor 502 does not have a misalignment problem. S300. Under the premise that the pressure sensor 502 is not inaccurate, perform a self-check to see if there is a yoke fault in the coil 404. S400 and diaphragm air pump 2 are started and run. The energization time of control coil 404 is 10 seconds. The second pressure output value of air adapter 3 under the set value of 10 seconds of energization is measured in advance, and the time required to reach the second pressure output value of 50Kpa is recorded as 13 seconds. S500 and pressure sensor 502 monitor the pressure output of the air outlet adapter 3 in real time for 13 seconds. If the detection value of pressure sensor 502 for 13 seconds is 40 kPa, which is significantly less than the second pressure output value of 50 kPa, then there is a yoke fault in coil 404.

[0036] The diaphragm air pump 2 is a purchased standard part, and its own damage or malfunction is not within the scope of the self-test function of this application. Moreover, the diaphragm air pump 2 is not prone to damage or malfunction during its service life. This application performs a self-test for whether the pressure sensor 502 is inaccurate by recording time. On the basis that the pressure sensor 502 is normal, the pressure detection of the pressure sensor 502 is used to perform a fault self-test for the coil 404. Since the internal space of the air outlet adapter 3 is limited, it is difficult to integrate other detection elements. Therefore, this application relies on the original pressure sensor 502 body and time difference to realize the fault self-test of the pressure sensor 502.

[0037] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A pump and valve integrated machine capable of actively adjusting pressure, characterized in that, include: Diaphragm air pump (2) and motor (1) for driving the diaphragm air pump (2) to operate; An air outlet adapter (3) and a pressure regulating solenoid valve (4) are arranged side by side at the air outlet end of the diaphragm air pump (2), and the bottom of the pressure regulating solenoid valve (4) is connected to the pressure relief slot (202) of the diaphragm air pump (2). The pressure regulating solenoid valve (4) has a stationary iron core (407) and a moving iron core (408) axially arranged on the inner side of the valve tube (403), which are connected by a spring (409). The outer side of the pressure regulating solenoid valve (4) is provided with a coil (404) for driving the moving iron core (408) to move axially. The monitoring component (5) has its pressure sensor (502) probe end inserted into the inside of the air outlet adapter (3). The monitoring component (5) is used to monitor the insufficient air outlet pressure of the diaphragm air pump (2). When the outlet pressure is insufficient, the coil (404) is energized and drives the stationary iron core (407) to move down and block the return channel of the pressure relief slot (202) to achieve system pressure boost; When the outlet pressure reaches the standard, the coil (404) is de-energized, the moving iron core (408) is reset, and the stationary iron core (407) works in conjunction with the spring (409) to perform normal pressure relief on the return channel of the pressure relief slot (202).

2. The pump and valve integrated machine capable of actively adjusting pressure according to claim 1, characterized in that, The monitoring component (5) is fixedly installed on the side of the air outlet adapter (3), and it also includes a control board (501) electrically connected to the pressure sensor (502).

3. The pump and valve integrated machine capable of actively adjusting pressure according to claim 2, characterized in that, The valve tube (403) is provided with a first mounting plate (401) and a second mounting plate (406) at its upper and lower ends, respectively. The coil (404) is arranged around the outside of the valve tube (403), and its two ends abut against the first mounting plate (401) and the second mounting plate (406), respectively.

4. The pump and valve integrated machine capable of actively adjusting pressure according to claim 3, characterized in that, The first mounting plate (401) and the second mounting plate (406) are connected to the control plate (501) via a C-shaped bracket (6), and the control plate (501) is clamped and limited between the C-shaped bracket (6) and the air outlet adapter (3).

5. A pump and valve integrated machine capable of actively adjusting pressure according to claim 4, characterized in that, The pressure relief slot (202) is provided with a pressure relief inlet (2021) and a pressure relief outlet (2022) in parallel, and one end of the two is connected to the air delivery chamber (206) of the diaphragm air pump (2), and the other end of the two is connected to the bottom of the valve pipe (403).

6. The pump and valve integrated machine capable of actively adjusting pressure according to claim 1, characterized in that, The diaphragm air pump (2) includes a power chamber (203) and an air delivery chamber (206). The top of the air supply chamber (206) is provided with an air outlet (201) connected to the air outlet adapter (3), and the air supply chamber (206) is provided with an air inlet pipe (205) connected downwards. The power chamber (203) is provided with a piston port (204) that communicates with the air supply chamber (206), and a piston (9) is provided on the piston port (204). The motor (1) is axially located at the bottom of the power chamber (203), and its output end is provided with an eccentric wheel (7). The eccentric wheel (7) is linked to the piston (9) through a swing arm (8).

7. A pump and valve integrated machine capable of actively adjusting pressure according to claim 5, characterized in that, The first mounting plate (401) and the second mounting plate (406) are connected to the C-shaped bracket (6) via pins (402); The bottom of the stationary iron core (407) is provided with a plug (405) that is pressed and covers the pressure relief inlet (2021) and the pressure relief outlet (2022).

8. The pump and valve integrated machine capable of actively adjusting pressure according to claim 1, characterized in that, When the coil (404) is energized, the downward electromagnetic attraction force on the moving iron core (408) is greater than the restoring force of the spring (409).

9. A pump and valve integrated machine capable of actively adjusting pressure according to any one of claims 1 to 8, characterized in that, The pump and valve integrated unit is used at the air inlet of the massage lumbar support.

10. A pump-valve integrated machine capable of actively adjusting pressure according to any one of claims 1 to 8, characterized in that, The fault detection method for the integrated pump and valve unit includes the following steps: S100. Self-check whether the pressure sensor (502) is inaccurate by recording time. Under the premise that the coil (404) is not energized and the pressure regulating solenoid valve (4) is under normal pressure relief, record the running time T0 from when the diaphragm air pump (2) runs until the air outlet adapter (3) reaches the first pressure output value. S200, the coil (404) is not energized, the diaphragm air pump (2) starts running, and the running time T1 when the air outlet adapter (3) actually reaches the first pressure output value is recorded. T0 is compared with T1. If there is a time difference, it proves that the pressure sensor (502) has an inaccuracy problem. S300. Under the premise that the pressure sensor (502) is not inaccurate, perform a self-test to check whether the coil (404) has a yoke fault. S400, the diaphragm air pump (2) is started and running, the energization time of the coil (404) is controlled to be a fixed value T2, the second pressure output value of the air outlet adapter (3) under the set value T2 energization time is measured in advance, and the time T3 required to reach the second pressure output value is recorded. S500, the pressure sensor (502) monitors the pressure output of the air outlet adapter (3) in real time under time T3. If the detection value of the pressure sensor (502) under time T3 is significantly less than the second pressure output value, then the coil (404) has a yoke iron fault.

Images