Passive exhaust valve and air pump for sphygmomanometer with same

Abstract

The utility model discloses a passive exhaust valve which comprises a valve body and a valve plate. The valve body is provided with a closed cavity, an air inlet hole, an air outlet hole and an exhaust hole, the valve plate is arranged in the closed cavity to divide the closed cavity into a first cavity and a second cavity, a communicating hole is formed in the valve plate, and the second cavity is communicated with the first cavity through the communicating hole. The first cavity is communicated with the air outlet and the exhaust hole, and the air inlet is communicated with the second cavity; the valve body is provided with a first abutting sealing structure and a second abutting sealing structure. When the valve block abuts against the first abutting sealing structure, the valve block cuts off communication between the air outlet hole and the exhaust hole, and the second abutting sealing structure opens communication between the second cavity and the first cavity. When the valve block abuts against the second abutting sealing structure, the valve block cuts off communication between the second cavity and the first cavity, and the first abutting sealing structure opens communication between the air outlet hole and the exhaust hole. The device has the advantages of small size, simple structure, no need of an external power supply and no electromagnetic interference. In addition, the utility model further discloses an air pump for the sphygmomanometer.

Description

Technical Field

[0001] This utility model relates to the field of blood pressure monitors, and in particular to a passive exhaust valve and an air pump for a blood pressure monitor having the exhaust valve. Background Technology

[0002] As we all know, hypertension has gradually risen to the top of the list of human diseases. How to conveniently and effectively measure and monitor hypertension, so as to effectively prevent and treat hypertension, has become an important issue for people to combat hypertension.

[0003] Currently, the use of a blood pressure monitor is indispensable for measuring blood pressure; it is a very common instrument for measuring blood pressure.

[0004] For blood pressure monitors, the use of an exhaust valve is indispensable. This exhaust valve is generally a solenoid valve, which is complex in structure and large in size. At the same time, it will generate electromagnetic interference when it is working.

[0005] Therefore, there is an urgent need for a passive exhaust valve and a blood pressure monitor pump with the exhaust valve to overcome one or more of the above-mentioned defects. Utility Model Content

[0006] One objective of this invention is to provide a passive exhaust valve that is small in size, simple in structure, requires no external power supply, and is free from electromagnetic interference.

[0007] Another objective of this invention is to provide a blood pressure pump that also has the advantages of the passive exhaust valve.

[0008] To achieve the above objectives, the passive exhaust valve of this utility model includes a valve body and a deformable valve plate. The valve body has a closed cavity, an inlet, an outlet, and an exhaust port; the valve plate is disposed in the closed cavity and sealed to the valve body, dividing the closed cavity into a first cavity and a second cavity separated from each other. The valve plate has a connecting hole, through which the second cavity communicates with the first cavity. The first cavity communicates with both the outlet and the exhaust port, and the inlet communicates with the second cavity. The valve body has a first pressure-sealing structure located in the first cavity and arranged around the outlet, and a first pressure-sealing structure located in the second cavity for opening or blocking the connecting hole. A second pressure-sealing structure with a through hole; when the valve plate deforms and shifts to press against the first pressure-sealing structure, the valve plate cuts off the communication between the outlet hole and the exhaust hole, and the second pressure-sealing structure releases its blockage of the through hole, opening the communication between the second cavity and the first cavity; when the valve plate deforms and shifts to press against the second pressure-sealing structure, the valve plate cuts off the communication between the second cavity and the first cavity, and the first pressure-sealing structure releases its pressure seal against the valve plate, opening the communication between the outlet hole and the exhaust hole.

[0009] Compared with existing technologies, this design utilizes a valve plate located within a closed cavity and sealed to the valve body. The valve plate divides the closed cavity into a first cavity and a second cavity, separated from each other. A connecting hole is provided on the valve plate, allowing the second cavity to connect with the first cavity via the connecting hole. The first cavity is connected to both the air outlet and the exhaust port, while the air inlet connects to the second cavity. The valve body is equipped with a first pressure-sealing structure located in the first cavity and surrounding the air outlet, and a second pressure-sealing structure located in the second cavity and used to open or block the connecting hole. Therefore, during inflation, as external gas enters the second cavity through the air inlet, the pressure in the second cavity becomes greater than that in the first cavity. This causes the valve plate to deform and shift to a position where it presses against the first pressure-sealing structure, thus cutting off the connection between the exhaust port and the air outlet. The second pressure-sealing structure, by disengaging from the pressure seal with the valve plate, opens the connection between the second chamber and the first chamber. This allows gas entering the second chamber through the inlet to pass through the connecting hole and the first chamber sequentially before exiting through the outlet, achieving the purpose of inflation. Simultaneously, during the exhaust process, because external gas is stopped from entering the second chamber through the inlet, the air pressure in the first chamber becomes greater than that in the second chamber. This causes the valve plate to deform and shift to a position where it presses against the first pressure-sealing structure, thus cutting off the connection between the second and first chambers. Meanwhile, the first pressure-sealing structure, by disengaging from the pressure seal with the valve plate, opens the connection between the outlet and the exhaust hole. This allows gas inside the bladder to exit through the outlet and the first chamber via the exhaust hole, achieving the purpose of exhaust.

[0010] Therefore, the passive exhaust valve of this utility model uses the air pressure difference in the chamber to control the opening and closing of the valve plate, change the air path connection channel, and realize the inflation or deflation control of the target capsule. It has the advantages of small size, simple structure, no need for external power supply and no electromagnetic interference.

[0011] Preferably, the valve body is further provided with an exhaust flow obstruction channel, and the exhaust port is connected to the first cavity through the exhaust flow obstruction channel.

[0012] Preferably, the two opposite flow channel sidewalls of the exhaust flow obstruction channel have serrations that are staggered from each other and protrude obliquely into the exhaust flow obstruction channel in a direction close to the first cavity.

[0013] Preferably, the serrations on the same flow channel sidewall of the exhaust flow obstruction channel are multiple and spaced apart from each other; the serrations have outwardly protruding convex tooth surfaces and inwardly concave tooth surfaces; in two adjacent serrations on the same flow channel sidewall of the exhaust flow obstruction channel, the outwardly protruding tooth surface of one serration and the inwardly concave tooth surface of the other serration together enclose a swirling cavity.

[0014] Preferably, the cyclone cavity is arc-shaped.

[0015] Preferably, the convex tooth surface has a slope.

[0016] Preferably, the valve body includes an upper cover and a lower cover assembled together, and the outer edge of the valve plate is sealed between the upper cover and the lower cover; the exhaust port, the air outlet and the first cavity are opened in the upper cover, the first pressure sealing structure is located in the upper cover, the air inlet and the second cavity are opened in the lower cover, and the second pressure sealing structure is located in the lower cover.

[0017] Preferably, the air outlet includes, in sequence along the direction away from the first cavity, a first frustum hole, a first cylindrical hole, a second frustum hole, and a second cylindrical hole. The first frustum hole, the first cylindrical hole, the second frustum hole, and the second cylindrical hole are arranged coaxially. The diameter of the second cylindrical hole is larger than the diameter of the first cylindrical hole. The upper bases of both the first frustum hole and the second frustum hole face the first cylindrical hole.

[0018] To achieve the above objectives, the air pump for the blood pressure monitor of this utility model includes a pump body and the aforementioned passive exhaust valve. The valve body is assembled and connected to the pump body, and the pump body delivers gas into the air inlet.

[0019] Preferably, the pump body is provided with a first pump chamber, a second pump chamber, a first one-way flow channel, a second one-way flow channel, a first inlet flow channel, a second inlet flow channel, a first air inlet, and a second air inlet. The first air inlet is connected to the air inlet of the first pump chamber through the first inlet flow channel. The first pump chamber is connected to the air inlet through the first one-way flow channel. The second air inlet is connected to the air inlet of the second pump chamber through the second inlet flow channel. The second pump chamber is connected to the air inlet through the second one-way flow channel. Attached Figure Description

[0020] Figure 1 This is a plan view of a blood pressure monitor air pump with the passive exhaust valve of this utility model.

[0021] Figure 2 It is along Figure 1 Internal view of the section cut by line segment AA.

[0022] Figure 3 It is along Figure 1 Internal view of the section cut by line segment BB.

[0023] Figure 4 Is Figure 2 The image shows the state of the capsule being inflated.

[0024] Figure 5 Is Figure 2 The diagram shows the process of releasing gas from the capsule.

[0025] Figure 6 This is a perspective view of the passive exhaust valve of this utility model.

[0026] Figure 7 yes Figure 6 The diagram shown is an exploded 3D view of a passive exhaust valve.

[0027] Figure 8 yes Figure 7 A three-dimensional exploded view from another angle.

[0028] Figure 9 yes Figure 8 Plan view of the lower cover and valve plate after they are hidden.

[0029] Figure 10 yes Figure 6 A plan view after being cut by the left and right planes passing through the center line of the vent.

[0030] Figure 11 Is Figure 10 The diagram shows the state of the valve plate deforming and displacing to form a pressure seal with the first pressure sealing structure.

[0031] Figure 12 Is Figure 10 The diagram shows the state of the valve plate deforming and displacing to form a pressure seal with the second pressure sealing structure. Detailed Implementation

[0032] To explain the technical content and structural features of this utility model in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0033] Please see Figures 1 to 5 The air pump 100 for a blood pressure monitor of this invention includes a passive exhaust valve 10 and a pump body 20. The pump body 20 is assembled and connected to the valve body 10 so that the pump body 20 and the valve body 10 are assembled together. Additionally, the pump body 20 also delivers gas into the air inlet 112 described below to meet subsequent needs. Optionally, in... Figures 2 to 5 As an example, the pump body 20 is provided with a first pump chamber 21, a second pump chamber 22, a first one-way flow channel 23, a second one-way flow channel 24, a first inlet flow channel 25, a second inlet flow channel 26, a first air inlet 27, and a second air inlet 28. The first air inlet 27 is connected to the air inlet 211 of the first pump chamber 21 via the first inlet flow channel 25, so as to meet the need for gas entering the first air inlet 27 from the outside to flow into the first pump chamber 21 along the first inlet flow channel 25. The first pump chamber 21 is connected to the first pump chamber 22 via the first one-way flow channel 23, a second one-way flow channel 24, a first inlet flow channel 25, a second inlet flow channel 26, a first air inlet 27, and a second air inlet 28. The flow channel 23 is connected to the air inlet 112 to prevent the gas in the air inlet 112 from flowing back into the first pump chamber 21; the second air inlet 28 is connected to the air inlet 221 of the second pump chamber 22 via the second air inlet flow channel 26 to meet the requirement that the gas entering the second air inlet 28 from the outside flows into the second pump chamber 22 along the second air inlet flow channel 26; the second pump chamber 22 is connected to the air inlet 112 via the second one-way flow channel 26 to prevent the gas in the air inlet 112 from flowing back into the second pump chamber 22. Furthermore, by utilizing the design of "the pump body 20 having a first pump chamber 21, a second pump chamber 22, a first one-way flow channel 23, a second one-way flow channel 24, a first air intake channel 25, a second air intake channel 26, a first air inlet 27, and a second air inlet 28", the pump body 20 can achieve the purpose of air intake through the air inlet 112 twice in one cycle. For example, the first pump chamber 21 completes the inflation of the first half of the cycle, and the second pump chamber 22 completes the inflation of the second half of the cycle, thus improving the inflation efficiency.

[0034] Combined Figures 10 to 12As an example, the passive exhaust valve 10 includes a valve body 11 and a deformable valve plate 12. The valve body 11 has a closed cavity 111, an inlet 112, an outlet 113, and an exhaust port 114. The valve plate 12 is disposed in the closed cavity 111 and is sealed to the valve body 11, dividing the closed cavity 111 into a first cavity 1111 and a second cavity 1112 that are separated from each other. The valve plate 12 has a connecting hole 121. As an example, the connecting hole 121 is a circular hole to facilitate the manufacturing and processing of the valve plate 12. Obviously, depending on actual needs, the connecting hole 121 can also be a hole of other shapes, so it is not considered... Figure 7 and Figure 8 As shown, the second chamber 1112 is connected to the first chamber 1111 via a connecting hole 121. The first chamber 1111 is connected to the air outlet 113 and the exhaust hole 114, respectively. The air inlet 112 is connected to the second chamber 1112. The valve body 11 is provided with a first pressure sealing structure 13 located in the first chamber 1111 and arranged around the air outlet 113 (see...). Figure 8 ) and a second pressure sealing structure 14 located in the second cavity 1112 and used to open or block the connecting hole 121 (see Figure 7 ).

[0035] Therefore, when the valve plate 12 deforms and shifts to press against the first pressure sealing structure 13, the valve plate 12 cuts off the communication between the vent hole 113 and the exhaust hole 114, and the second pressure sealing structure 14 disengages from blocking the connecting hole 121, opening the communication between the second chamber 1112 and the first chamber 1111. (See the attached diagram.) Figure 11 As shown, the purpose is to allow the gas entering the second chamber 1112 through the air inlet 112 to enter the first chamber 1111 through the connecting hole 121, and then flow into the bladder 200 along the air outlet 113, so as to inflate the bladder 200.

[0036] Simultaneously, when the valve plate 12 deforms and shifts to press against the second pressure sealing structure 14, the valve plate 12 cuts off the communication between the second chamber 1112 and the first chamber 1111. The first pressure sealing structure 13 disengages from the pressure seal with the valve plate 12 and opens the communication between the vent hole 113 and the exhaust hole 114, as shown in Figure 12. This allows the gas inside the bladder 200 to enter the first chamber 111 through the vent hole 113 and then be discharged outward through the exhaust hole 114. More specifically, as follows:

[0037] like Figure 8 As shown, as an example, the first pressure-sealing structure 13 is a circular structure, which facilitates the processing and manufacturing of the first pressure-sealing structure 13 and also facilitates the pressure-sealing fit between the first pressure-sealing structure 13 and the valve plate 12; obviously, depending on actual needs, the shape of the first pressure-sealing structure 13 can also be other, so it is not considered... Figure 8 The above is for reference only. Additionally, regarding... Figure 7 In this example, the second pressure-sealing structure 14 is a frustum structure, which facilitates its manufacturing and also ensures a proper pressure-sealing fit between the valve plate 12 and the second pressure-sealing structure 14. Obviously, the shape of the second pressure-sealing structure 14 can be other than that required, so it is not specified here. Figure 7 The above is the limit.

[0038] like Figures 9 to 10 As shown, as an example, the valve body 11 is also provided with an exhaust flow obstruction channel 15, and the exhaust port 114 is connected to the first chamber 1111 through the exhaust flow obstruction channel 15; therefore, by means of the exhaust flow obstruction channel 15, the exhaust velocity can be reduced, effectively suppressing the high-velocity airflow generated during high-pressure exhaust and preventing the valve plate 12 from whistling. Specifically, in Figure 9 In the example, the two flow channel sidewalls of the exhaust flow obstruction channel 15 (e.g., but not limited to) Figure 9 The upper and lower flow channel sidewalls shown have serrations 15a that are staggered and protrude into the exhaust flow obstruction channel 15 at an angle toward the first cavity 1111. This design can further reduce the exhaust velocity and more effectively suppress the whistling of the valve plate 12 caused by the high-velocity airflow during high-pressure exhaust. More specifically, in Figure 9 In this example, the serrations 15a on the same flow channel sidewall of the exhaust flow obstruction channel 15 are multiple serrations spaced apart from each other, such as, but not limited to, those mentioned above. Figure 9 The two or three serrations shown have outwardly convex tooth surfaces 151 and inwardly concave tooth surfaces 152. In two adjacent serrations 15a on the same flow channel sidewall of the exhaust flow obstruction channel 15, the outwardly convex tooth surface 151 of one serration 15a and the inwardly concave tooth surface 152 of the other serration 15a together enclose a swirling cavity 153. Optionally, as an example, the swirling cavity 153 is arc-shaped, and the outwardly convex tooth surface 151 has a slope. The purpose of this design is... The process is as follows: When gas flows from the first chamber 1111 to the exhaust port 114, according to the Coanda effect, the fluid has a wall-attaching effect. Under this effect, the main gas flows along the toothed walls on both sides of the exhaust obstruction channel 15. One side of the gas flows towards the exhaust port 114, while the other side enters the vortex chamber 153, forming a backflow opposite to the exhaust flow direction. The two gas streams interfere with each other, reducing the exhaust velocity. The greater the exhaust pressure and the faster the airflow velocity, the greater the reverse resistance. Therefore, this process minimizes the whistling sound generated by the valve plate 12 due to the high-velocity airflow during high-pressure exhaust.

[0039] like Figures 2 to 8 ,as well as Figures 10 to 12As shown, as an example, the valve body 11 includes an upper cover 11a and a lower cover 11b assembled together. The outer edge 122 of the valve plate 12 is sealed between the upper cover 11a and the lower cover 11b. This design facilitates the assembly operation between the valve body 11 and the valve plate 12. When the valve body 11 includes the upper cover 11a and the lower cover 11b, the exhaust port 114, the air outlet 113, and the first cavity 1111 are opened in the upper cover 11a. The first pressure sealing structure 13 is located in the upper cover 11a. The air inlet 112 and the second cavity 1112 are opened in the lower cover 11b. The second pressure sealing structure 14 is located in the lower cover 11b. For example, both the upper cover 11a and the lower cover 11b can be obtained by plastic injection molding; the valve plate 12 can be made of materials such as rubber and silicone to give the valve plate 12 good elasticity; obviously, depending on actual needs, the materials of the valve plate 12, the upper cover 11a and the lower cover 11b can also be other.

[0040] like Figures 2 to 5 ,as well as Figures 10 to 12 As shown in the figure, as an example, the air outlet 113 sequentially includes a first frustum hole 1131, a first cylindrical hole 1132, a second frustum hole 1133, and a second cylindrical hole 1134 along the direction away from the first cavity 1111. The first frustum hole 1131, the first cylindrical hole 1132, the second frustum hole 1133, and the second cylindrical hole 1134 are arranged coaxially. The diameter of the second cylindrical hole 1134 is larger than the diameter of the first cylindrical hole 1132. The upper bottoms of both the first frustum hole 1131 and the second frustum hole 1133 face the first cylindrical hole 1132. This allows the gas in the first cavity 1111 to be obstructed and accelerated during its entry into the bladder 200, thereby ensuring that the gas is evenly filled into the bladder 200 and reducing airflow fluctuations.

[0041] Combination Figure 4 and Figure 5 The following explains the filling and venting process:

[0042] During inflation, the pump body 20 draws in gas from the outside and pumps it out, allowing it to flow into the second chamber 1112 of the valve body 11. As the pressure in the second chamber 1112 of the valve body 11 increases, the valve plate 12 deforms and shifts upward under pressure to the position of the first pressure-sealing structure 13. This allows the gas in the second chamber 1112 to flow from the connecting hole 121 of the valve plate 12 and the first chamber 1111 into the vent hole 113, thus inflating the bladder 200. (See attached diagram.) Figure 4 As shown.

[0043] During exhaust, the pump body 20 stops working, that is, the vibrator 29 in the pump body 20 stops working, allowing the gas inside the pump body 20 to be discharged to the outside. Due to the pressure release in the second chamber 1112 of the valve body 11, the valve plate 12 is deformed and displaced by the compressed air inside the bladder 200, causing the valve plate 12 to disengage from the pressure seal of the first pressure sealing structure 13, thus allowing the first chamber 1111 to communicate with the bladder 200. Simultaneously, the valve plate 12 deforms and displaces to a position where it presses against the second pressure sealing structure 14, which blocks the communicating hole 121 of the valve plate 12. Therefore, the compressed air inside the bladder 200 flows into the first chamber 1111, then, after being slowed down by the exhaust obstruction channel 15, is discharged to the outside through the exhaust hole 114, as shown in the diagram. Figure 5 As shown. It should be noted that the pump body 20 can be selected as a piezoelectric pump body.

[0044] Compared with the prior art, the valve plate 12 is disposed in the closed cavity 111 and sealed to the valve body 11. The valve plate 12 divides the closed cavity 111 into a first cavity 1111 and a second cavity 1112 that are separated from each other. The valve plate 12 has a connecting hole 121. The second cavity 1112 is connected to the first cavity 1111 through the connecting hole 121. The first cavity 1111 is connected to the air outlet 113 and the air exhaust hole 114 respectively. The air inlet 112 is connected to the second cavity 1112. The valve body 11 is provided with a first pressure sealing structure 13 located in the first cavity 1111 and arranged around the air outlet 113, and a second pressure sealing structure 14 located in the second cavity 1112 and used to open or block the connecting hole 121. In this design, during inflation, external gas enters the second chamber 1112 through the air inlet 112, causing the air pressure in the second chamber 1112 to be greater than that in the first chamber 1111. This causes the valve plate 12 to deform and shift to a position where it presses against the first pressure-sealing structure 13. Consequently, the valve plate 12 cuts off the connection between the exhaust port 114 and the outlet port 113. The second pressure-sealing structure 14, having broken free from the pressure seal with the valve plate 12, opens the connection between the second chamber 1112 and the first chamber 1111. This allows the gas entering the second chamber 1112 through the air inlet 112 to flow out through the outlet port 113 sequentially through the connecting hole 121 and the first chamber 1111, thus achieving the inflation purpose. (See attached diagram). Figure 4As shown; simultaneously, during the exhaust process, because external gas is stopped from entering the second chamber 1112 through the air inlet 112, the air pressure in the first chamber 1111 is greater than that in the second chamber 1112. This causes the valve plate 12 to deform and shift to a position where it presses against the first pressure sealing structure 13, thereby cutting off the connection between the second chamber 1112 and the first chamber 1111. The first pressure sealing structure 13, having disengaged from the pressure seal with the valve plate 12, opens the connection between the air outlet 113 and the exhaust port 114. Thus, the gas inside the bladder 200 is exhausted through the air outlet 113 and the first chamber 1111, and then through the exhaust port 114, achieving the purpose of exhaust. (See the diagram for the state.) Figure 5 As shown. Therefore, the passive exhaust valve 10 of this utility model uses the air pressure difference in the chamber to control the opening and closing of the valve plate 12, change the air path connection channel, and realize the inflation or deflation control of the target bladder 200. It has the advantages of small size, simple structure, no need for external power supply and no electromagnetic interference.

[0045] The above-disclosed examples are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall fall within the scope of the present utility model.

Claims

1. A passive exhaust valve, characterized in that, The valve includes a valve body and a deformable valve plate. The valve body has a closed cavity, an air inlet, an air outlet, and an exhaust port. The valve plate is disposed in the closed cavity and is sealed to the valve body. The valve plate divides the closed cavity into a first cavity and a second cavity that are separated from each other. The valve plate has a connecting hole, through which the second cavity communicates with the first cavity. The first cavity communicates with both the air outlet and the exhaust port. The air inlet communicates with the second cavity. The valve body has a first pressure-sealing structure located in the first cavity and arranged around the air outlet, and a sealing structure located in the second cavity for sealing. A second pressure-sealing structure opens or blocks the connecting hole; when the valve plate deforms and shifts to press against the first pressure-sealing structure, the valve plate cuts off the communication between the air outlet and the exhaust hole, and the second pressure-sealing structure releases its blockage of the connecting hole, opening the communication between the second cavity and the first cavity; when the valve plate deforms and shifts to press against the second pressure-sealing structure, the valve plate cuts off the communication between the second cavity and the first cavity, and the first pressure-sealing structure releases its pressure seal against the valve plate, opening the communication between the air outlet and the exhaust hole.

2. The passive exhaust valve according to claim 1, characterized in that, The valve body is also provided with an exhaust flow obstruction channel, and the exhaust hole is connected to the first cavity through the exhaust flow obstruction channel.

3. The passive exhaust valve according to claim 2, characterized in that, The two opposite flow channels of the exhaust flow obstruction channel have serrations that are staggered from each other and protrude into the exhaust flow obstruction channel at an angle toward the direction of the first cavity.

4. The passive exhaust valve according to claim 3, characterized in that, The serrations on the same flow channel sidewall of the exhaust flow obstruction channel are multiple and spaced apart from each other; the serrations have outwardly protruding convex tooth surfaces and inwardly concave tooth surfaces; in two adjacent serrations on the same flow channel sidewall of the exhaust flow obstruction channel, the outwardly protruding tooth surface of one serration and the inwardly concave tooth surface of the other serration together enclose a swirling cavity.

5. The passive exhaust valve according to claim 4, characterized in that, The cyclone cavity is arc-shaped.

6. The passive exhaust valve according to claim 4, characterized in that, The convex tooth surface has a slope.

7. The passive exhaust valve according to claim 1, characterized in that, The valve body includes an upper cover and a lower cover assembled together, and the outer edge of the valve plate is sealed between the upper cover and the lower cover; the exhaust port, the air outlet and the first cavity are opened in the upper cover, the first pressure sealing structure is located in the upper cover, the air inlet and the second cavity are opened in the lower cover, and the second pressure sealing structure is located in the lower cover.

8. The passive exhaust valve according to claim 1, characterized in that, The air outlet includes, in sequence, a first frustum hole, a first cylindrical hole, a second frustum hole, and a second cylindrical hole along the direction away from the first cavity. The first frustum hole, the first cylindrical hole, the second frustum hole, and the second cylindrical hole are arranged coaxially. The diameter of the second cylindrical hole is larger than the diameter of the first cylindrical hole. The upper bottoms of both the first frustum hole and the second frustum hole face the first cylindrical hole.

9. An air pump for a blood pressure monitor, comprising a pump body, characterized in that, The air pump for the blood pressure monitor further includes a passive exhaust valve according to any one of claims 1 to 8, wherein the valve body is assembled and connected to the pump body, and the pump body delivers gas into the air inlet.

10. The pump body according to claim 9, characterized in that, The pump body is provided with a first pump chamber, a second pump chamber, a first one-way flow channel, a second one-way flow channel, a first inlet flow channel, a second inlet flow channel, a first air inlet, and a second air inlet. The first air inlet is connected to the air inlet of the first pump chamber through the first inlet flow channel. The first pump chamber is connected to the air inlet through the first one-way flow channel. The second air inlet is connected to the air inlet of the second pump chamber through the second inlet flow channel. The second pump chamber is connected to the air inlet through the second one-way flow channel.

Images