Air outlet structure and piezoelectric air pump with same
By designing staggered inclined sawtooth structures on both sides of the air outlet channel of the pneumatic pump, and utilizing the Coanda effect to form reverse backflow, the problem that mechanical check valves cannot meet high-frequency operation is solved, and the stability and efficiency of the air pump are improved at high frequencies.
Patent Information
- Application Number
- CN202422709763.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-06
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-06
AI Technical Summary
In existing pneumatic pump designs, mechanical check valves cannot meet the requirements of high-frequency operation, leading to problems such as aging and wear and high material requirements.
An inclined sawtooth structure with staggered arrangement on both sides of the air outlet channel is adopted to realize gas wall flow by utilizing the Coanda effect, forming reverse backflow, eliminating the need for a mechanical check valve and improving the response frequency.
It effectively reduces backflow velocity, avoids aging and wear of mechanical check valves, reduces material requirements, increases response frequency, and enhances the stability and efficiency of air pumps.
Smart Images
Figure CN223516345U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a gas pump applied to microelectronic, medical treatment, health care and the like industry, especially to a gas outlet structure and piezoelectric gas pump with the gas outlet structure. BACKGROUND
[0002] It is well known that hypertension has gradually risen to the top of the list of human disease hazards, and how to conveniently and effectively measure and monitor hypertension so as to effectively prevent and treat hypertension has become an important problem for people to fight against hypertension.
[0003] At present, the measurement of blood pressure cannot be separated from the use of a sphygmomanometer, which is a very common instrument for measuring blood pressure.
[0004] Among them, for the sphygmomanometer, the use of a gas pump is indispensable, and the gas pump inflates the air bag to meet the needs of the sphygmomanometer for blood pressure testing. Since the piezoelectric gas pump has the advantages of small noise, small size, small airflow ripple, and stable flow compared to the traditional motor gas pump, it has obvious performance advantages in the application of sphygmomanometers.
[0005] However, the existing piezoelectric gas pump is generally designed as a volumetric reciprocating pump, and a check valve structure needs to be provided at the inlet and outlet of the pump chamber to prevent backflow of the fluid. Since the piezoelectric pump has a high working frequency, especially the piezoelectric pump that needs to be silent, its working frequency is often set to more than 20 kHz. Therefore, the corresponding check valve also needs a corresponding frequency response, and the general traditional mechanical check valve structure cannot meet the requirements.
[0006] Therefore, there is an urgent need for a gas outlet structure and a piezoelectric gas pump with the gas outlet structure to overcome one or more of the above-mentioned defects. SUMMARY
[0007] One purpose of the utility model is to provide a gas outlet structure that cancels the mechanical check valve, avoids the aging loss of the mechanical check valve, and has the advantages of low material requirements and high response frequency.
[0008] Another purpose of the utility model is to provide a piezoelectric gas pump that cancels the mechanical check valve, avoids the aging loss of the mechanical check valve, and has the advantages of low material requirements and high response frequency.
[0009] To achieve the above-mentioned purpose, the air outlet structure comprises a structure main body, an air outlet channel and an external discharge channel provided on the structure main body, and the external discharge channel is communicated with the air outlet channel. Opposite two channel side walls of the air outlet channel are provided with first sawteeth which are staggered and inclined to the direction of the external discharge channel. The first sawteeth on the same channel side wall of the air outlet channel are separated from each other, and the first sawteeth have outward protruding first outer tooth surfaces and inward recessed first inner tooth surfaces. The first outer tooth surface of one first sawtooth and the first inner tooth surface of another first sawtooth together enclose a first rotation cavity.
[0010] Compared with the prior art, the first sawteeth on the opposite two channel side walls of the air outlet channel are staggered and inclined to the direction of the external discharge channel. The first sawteeth on the same channel side wall of the air outlet channel are separated from each other, and the first sawteeth have outward protruding first outer tooth surfaces and inward recessed first inner tooth surfaces. The first outer tooth surface of one first sawtooth and the first inner tooth surface of another first sawtooth together enclose a first rotation cavity. When the gas flows reversely from the external discharge channel to the air outlet channel, according to the Coanda effect, the fluid has a wall attachment effect. Under the wall attachment effect of the gas, the main gas flows along the tooth walls on both sides of the air outlet channel, the gas on one side flows reversely along the air outlet channel, and the gas on the other side enters the first rotation cavity to form a backflow opposite to the reverse flow. The two gas streams interfere with each other to reduce the reverse flow speed. When the reverse gas pressure is greater and the gas flow speed is faster, the reverse resistance is also greater, thereby achieving the purpose of canceling the mechanical check valve, avoiding the aging loss of the mechanical check valve, and having the advantages of low material requirement and high response frequency.
[0011] Preferably, the external discharge channel comprises a first circular cone cavity, a first cylindrical cavity and a second circular cone cavity in sequence along a first direction, the first cylindrical cavity is communicated with the cavity top of both the first circular cone cavity and the second circular cone cavity, the cavity diameter of the first cylindrical cavity is smaller than the cavity bottom size of both the first circular cone cavity and the second circular cone cavity, and a cone body protruding into the second circular cone cavity and matched with the second circular cone cavity is arranged on the structure main body.
[0012] Preferably, the side wall surface of the cone body is matched with the side cavity wall surface of the second circular cone cavity, and the air outlet channel penetrates the side wall surface of the cone body or the side cavity wall surface of the second circular cone cavity.
[0013] To achieve the above object, the piezoelectric air pump comprises a vibrator and the aforementioned air outlet structure. A cavity is formed in the structure body, the vibrator is horizontally arranged in the cavity and is in sealed connection with the structure body, the vibrator divides the cavity into a first pump chamber and a second pump chamber, and the first pump chamber and the second pump chamber are in communication with the air outlet channel and the external discharge channel through the air outlet channel.
[0014] Preferably, the air outlet channel is arranged in two opposite positions with the external discharge channel as the center, one of the air outlet channels is in communication with the external discharge channel and the exhaust port of the first pump chamber, and the other air outlet channel is in communication with the external discharge channel and the exhaust port of the second pump chamber.
[0015] Preferably, the structure body is further provided with air inlet channels in communication with the first pump chamber and the second pump chamber, respectively, and the opposite two channel side walls of the air inlet channel are provided with second sawteeth arranged staggeredly and protruding obliquely in the air inlet channel towards the outlet of the air inlet channel.
[0016] Preferably, the second sawteeth arranged on the same channel side wall of the air inlet channel are arranged in plurality and are spaced apart from each other, the second sawteeth are provided with a second outward protruding tooth surface and a second inward recessed tooth surface, and the second outward protruding tooth surface of one of the second sawteeth and the second inward recessed tooth surface of the other second sawteeth together enclose a second spiral cavity.
[0017] Preferably, the vibrator comprises a vibrating plate and a piezoelectric ceramic sheet, the vibrating plate comprises an outer connecting portion for sealed connection with the structure body, a flat portion surrounded by the outer connecting portion, and a corrugated suspension portion connected between the flat portion and the outer connecting portion, and the piezoelectric ceramic sheet is fixed to the flat portion.
[0018] Preferably, the structure body comprises, in sequence along the first direction, a cover body, a first cover plate, a hollow middle plate and a second cover plate fixed together in stack, the vibrator is clamped between the middle plate and the second cover plate in sealed fit, the external discharge channel penetrates through the cover body, the air inlet channel and the air outlet channel are jointly enclosed by the cover body and the first cover plate, the first pump chamber is jointly enclosed by the first cover plate, the middle plate and the vibrator, the second pump chamber is jointly enclosed by the vibrator and the second cover plate, the exhaust port and the air inlet port of the first pump chamber are both located on the middle plate, and the exhaust port and the air inlet port of the second pump chamber are both located on the second cover plate.
[0019] Preferably, the structure body comprises, in sequence along the first direction, a cover, a first cover plate, a first end cover, a hollow first middle plate, a hollow second middle plate, a second end cover and a second cover plate fixed together in layers; the vibrator is clamped in sealing fit in the first middle plate and the second middle plate; the air outlet channel penetrates through the cover, the air outlet channel is enclosed by the cover and the first cover plate, the air inlet channel connected with the first pump chamber is enclosed by the first cover plate and the first end cover, the air inlet channel connected with the second pump chamber is enclosed by the second end cover and the second cover plate; the first pump chamber is enclosed by the first end cover, the first middle plate and the vibrator, the second pump chamber is enclosed by the vibrator, the second middle plate and the second end cover; the air inlet of the first pump chamber is located on the first end cover, the air outlet of the first pump chamber is located on the first middle plate; the air inlet of the second pump chamber is located on the second end cover, and the air outlet of the second pump chamber is located on the second middle plate. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a perspective view of a piezoelectric air pump with the air outlet structure of the first embodiment of the present application.
[0021] Figure 2 is Figure 1 a perspective exploded view of the piezoelectric air pump shown in Fig. 1.
[0022] Figure 3 is Figure 2 a perspective exploded view from another angle.
[0023] Figure 4 is Figure 1 a plan view of the piezoelectric air pump shown in Fig. 1, viewed in the direction indicated by arrow A.
[0024] Figure 5 is Figure 4 an internal view along the B-B line in Fig. 1, with the vibrator in the initial position.
[0025] Figure 6 is Figure 5 a state diagram showing the vibrator deformed in the direction of reducing the volume of the first pump chamber to the first limit position, based on Fig. 2.
[0026] Figure 7 is Figure 5 a state diagram showing the vibrator deformed in the direction of reducing the volume of the second pump chamber to the second limit position, based on Fig. 3.
[0027] Figure 8 is Figure 4 an internal view along the C-C line in Fig. 1, with the vibrator in the initial position.
[0028] Figure 9Is Figure 8 Based on this, a state diagram is shown when the vibrator reduces the volume of the first pump chamber and the directional deformation displacement reaches the first limit position.
[0029] Figure 10 Is Figure 8 Based on this, a state diagram is shown when the vibrator deforms and displaces in the direction of reducing the volume of the second pump chamber to the second limit position.
[0030] Figure 11 yes Figure 3 The diagram shows a plan view of the cover in the pneumatic pump.
[0031] Figure 12 yes Figure 11 Enlarged view of section F in the middle.
[0032] Figure 13 yes Figure 11 A magnified view of section G in the middle.
[0033] Figure 14 This is a perspective view of a pneumatic pump having the air outlet structure of the second embodiment of this utility model.
[0034] Figure 15 yes Figure 14 The diagram shown is an exploded 3D view of the pneumatic pump.
[0035] Figure 16 yes Figure 15 A three-dimensional exploded view from another angle.
[0036] Figure 17 yes Figure 14 The diagram shows a plan view of the pneumatic pump viewed in the direction indicated by arrow A.
[0037] Figure 18 It is along Figure 17 Internal view of the vibrator when cut along the FF line and in its initial position.
[0038] Figure 19 It is along Figure 17 Internal view with the vibrator in its initial position, cut along the GG line. Detailed Implementation
[0039] 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.
[0040] Please see Figure 1 As an example, the piezoelectric pump 1000 having the gas outlet structure 100 of the first embodiment can be applied to a blood pressure monitor to pump gas into the air bladder of the blood pressure monitor.
[0041] Combined Figure 5 andFigure 8 The piezoelectric pump 1000 comprises the vibrator 200 and the gas outlet structure 100 of the first embodiment. The gas outlet structure 100 of the first embodiment comprises the structure body 10 and the gas outlet passage 20 and the exhaust passage 30 formed on the structure body 10. The exhaust passage 30 is communicated with the gas outlet passage 20 to meet the requirement that the gas in the first pump chamber 51 and the second pump chamber 52 described below enters the exhaust passage 30 through the gas outlet passage 20. Alternatively, in Figure 5 and Figure 8 , as an example, the exhaust passage 30 comprises the first circular conical cavity 31, the first cylindrical cavity 32 and the second circular conical cavity 33 in sequence in the first direction (see the arrow A), and alternatively, in Figure 5 , as an example, the center lines of the first circular conical cavity 31, the first cylindrical cavity 32 and the second circular conical cavity 33 coincide, and the coincided center line can be seen in the center line in Figure 5 . Obviously, according to actual requirements, the center line relationship of the first circular conical cavity 31, the first cylindrical cavity 32 and the second circular conical cavity 33 can also be other, and is not limited to Figure 5 . In addition, the first cylindrical cavity 32 is communicated with the cavity top 311 (331) of the first circular conical cavity 31 and the second circular conical cavity 33 respectively, and the cavity diameter of the first cylindrical cavity 32 is smaller than the size of the cavity bottom 312 (332) of the first circular conical cavity 31 and the second circular conical cavity 33. This design makes the gas entering the exhaust passage 30 from the gas outlet passage 20 into the gas of high inertia and high flow rate and then pumped out. In addition, the structure body 10 is provided with the cone 40 protruding into the second circular conical cavity 33 and matched with the second circular conical cavity 33, and alternatively, in Figure 5 , as an example, the center line of the cone 40 also coincides with the center line of the second circular conical cavity 33, and the coincided center line can be seen in the center line in Figure 5 . In addition, the cavity 50 is formed in the structure body 10.
[0042] In combination with Figure 11 and Figure 12 , the first sawtooth 21 is arranged on the opposite two passage side walls of the gas outlet passage 20 and protrudes into the gas outlet passage 20 in the direction close to the exhaust passage 30. The first sawtooth 21 on the same passage side wall of the gas outlet passage 20 is separated from each other, for example, but not limited to two or three as shown in Figure 12 . The first sawtooth 21 has the first outward protruding tooth surface 211 and the first inward recessed tooth surface 212. In the adjacent two first sawteeth 21 on the same passage side wall of the gas outlet passage 20, the first outward protruding tooth surface 211 of one first sawtooth 21 and the first inward recessed tooth surface 212 of the other first sawtooth 21 jointly enclose a first convolution cavity 213, and alternatively, in Figure 12In the embodiment, as an example, the first rotary chamber 213 is arc-shaped, and the first outer convex tooth surface 211 has a slope to obtain a more effective backflow suppression effect.
[0043] The vibrator 200 is horizontally arranged in the cavity 50 and is sealingly connected with the structure body 10 to prevent leakage between the vibrator 200 and the structure body 10; the vibrator 200 divides the cavity 50 into the first pump chamber 51 and the second pump chamber 52, and each of the first pump chamber 51 and the second pump chamber 52 is communicated with the exhaust passage 30 by means of the air outlet passage 20; in this way, the piezoelectric pump 1000 can complete twice gas suction and twice gas pumping in one working cycle, greatly improving the pumping efficiency and the exhaust flow to adapt to large flow occasions; in addition, the piezoelectric pump 1000 is smaller in size under the condition of the same flow. More specifically, as follows:
[0044] As shown in Figure 8 to Figure 10 , as an example, the side wall surface 41 of the cone 40 is fitted with the side cavity wall surface 331 of the second circular cone cavity 33; in addition, as shown in Figure 5 to Figure 7 , as an example, the air outlet passage 20 also penetrates the side cavity wall surface 333 of the second circular cone cavity 33, that is, in the side cavity wall surface 333 of the second circular cone cavity 33, except the position penetrated by the air outlet passage 20, the remaining position is fitted with the side wall surface 41 of the cone 40; obviously, according to actual needs, the air outlet passage 20 can also penetrate the side wall surface 41 of the cone 40, so it is not limited to be shown in Figure 5 to Figure 7 .
[0045] As shown in Figure 3 , Figure 5 to Figure 7 , and Figure 11 , as an example, the air outlet passage 20 is arranged opposite to the exhaust passage 30, one air outlet passage 20 is communicated with the exhaust passage 30 and the exhaust port 511 of the first pump chamber 51, and the other air outlet passage 20 is communicated with the exhaust passage 30 and the exhaust port 521 of the second pump chamber 52.
[0046] As shown in Figure 1 to Figure 2 , and Figure 8 to Figure 11 , as an example, the structure body 10 is further provided with the air inlet passage 60 communicated with the first pump chamber 51 and the second pump chamber 52, respectively, and the opposite two passage side walls of the air inlet passage 60 have the second sawtooth 62 arranged staggered with each other and protruding in the air inlet passage 60 in the direction of the outlet 61 of the air inlet passage 60, the second sawtooth 62 located on the same passage side wall of the air inlet passage 60 is a plurality of, for example, but not limited to two or three as shown in Figure 13 ; in addition, as shown in Figure 11 and Figure 13In the embodiment, as an example, the second sawtooth 62 has a second outward convex tooth surface 621 and a second inward concave tooth surface 622; in the adjacent two second sawtooth 62 of the same channel side wall of the air inlet channel 60, the second outward convex tooth surface 621 of one second sawtooth 62 and the second inward concave tooth surface 622 of the other second sawtooth 62 jointly enclose a second rotation cavity 623; the purpose of such design is that when the gas in the first pump chamber 51 and the second pump chamber 52 flows reversely to the air inlet channel 60, according to the Coanda effect, the fluid has a wall attachment effect, under the wall attachment effect of the gas, the main gas flows along the tooth wall on both sides of the air inlet channel 60, the gas on one side flows reversely to the air inlet channel 60, and the gas on the other side enters the second rotation cavity 623 to form a backflow opposite to the reverse flow, the two gases interfere with each other, and the state is shown in Figure 13 The dashed arrow shown in the figure indicates that the reverse flow speed is reduced; when the reverse gas pressure is greater and the gas flow speed is faster, the reverse resistance is also greater; therefore, the air inlet channel 60 effectively hinders the gas in the first pump chamber 51 and the second pump chamber 52 from flowing reversely to the outside through the air inlet channel 60, so that the mechanical check valve is cancelled on the air inlet side through the air inlet channel 60 designed in this way. Specifically, as shown in Figure 13 In the embodiment, as an example, the second rotation cavity 623 is arc-shaped, and the second outward convex tooth surface 621 has a slope to obtain a better reverse flow resistance effect. In addition, as shown in Figure 3 and Figure 8 to Figure 11 In the embodiment, as an example, the air inlet channel 60 is arranged in pairs with the exhaust channel 30 as the center, so that the air inlet 512 of the first pump chamber 51 is communicated with the outside through one air inlet channel 60, and the air inlet 522 of the second pump chamber 52 is communicated with the outside through the other air inlet channel 60; obviously, according to actual needs, the number of the air inlet channel 60 can also be other, and is not limited to Figure 3 and Figure 8 to Figure 11 In the embodiment, as an example, the air inlet channel 60 is arranged in pairs with the exhaust channel 30 as the center, so that the air inlet 512 of the first pump chamber 51 is communicated with the outside through one air inlet channel 60, and the air inlet 522 of the second pump chamber 52 is communicated with the outside through the other air inlet channel 60; obviously, according to actual needs, the number of the air inlet channel 60 can also be other, and is not limited to
[0047] As shown in Figure 2 to Figure 3 , and Figure 5 to Figure 10As shown, as an example, the vibrator 200 includes a vibrating plate 210 and a piezoelectric ceramic sheet 220. The vibrating plate 210 includes an outer connecting portion 211 for sealing connection with the main body structure 10, a flat portion 212 surrounded by the outer connecting portion 211, and a corrugated suspension portion 213 connecting the flat portion 212 and the outer connecting portion 211. The piezoelectric ceramic sheet 220 is fixed at the flat portion 212. Therefore, the stability of the piezoelectric ceramic sheet 220 fixed to the vibrating plate 210 is improved by means of the flat portion 212. For example, the piezoelectric ceramic sheet 220 can be glued to the flat portion 212. In addition, the corrugated suspension portion 213 can withstand a large deformation displacement. Specifically, as an example, the vibrating plate 210 can be made of copper alloys such as phosphor bronze, beryllium copper, or stainless steel, which are conductive metals with good elasticity. The two end faces of the piezoelectric ceramic sheet 220 are two electrodes. The vibrating plate 210 serves as one electrode of the piezoelectric ceramic sheet 220, and an electrode lug 221 is welded to the other side of the piezoelectric ceramic sheet 220 and led out to the outside. This electrode lug 221 can be made of a conductive metal material. Additionally, the external connection portion 211 of the vibrating plate 210 is provided with an external lug 214. Therefore, when an alternating voltage is applied to the electrode lug 221 and the external lug 214, the piezoelectric ceramic sheet 220 undergoes stretching and contraction deformation due to the inverse piezoelectric effect, thereby driving the vibrator 200 to... Figure 5 to Figure 10 The vibrating plate 210 vibrates up and down. More specifically, the corrugated suspension part 213 of the vibrating plate 210 can be made by stamping, but is not limited to this.
[0048] like Figure 1 to Figure 3 ,as well as Figure 5 to Figure 10 As shown, as an example, the main structure 10 sequentially comprises a cover 11, a first cover plate 12, a hollow middle plate 13, and a second cover plate 14, which are stacked and fixed together along a first direction. The vibrator 200 is sealed between the middle plate 13 and the second cover plate 14; an external discharge channel 30 penetrates the cover 11 to facilitate the manufacturing and processing of the external discharge channel 30 on the cover 11; a cone 40 is located on the first cover plate 12, optionally... Figure 5 to Figure 10 In the example shown, the cone 40 and the first cover plate 12 are integrally formed; obviously, depending on actual needs, the two can also be fixed together by assembly, so it is not considered that... Figure 5 to Figure 10 The diagram shows only the limited extent of the information provided. Both the intake passage 60 and the exhaust passage 20 are enclosed by the cover 11 and the first cover plate 12 to facilitate the manufacturing and processing of both. Optionally, [the diagram could be inserted here]. Figure 3In the embodiment, as an example, the air inlet channel 60 and the air outlet channel 20 are both formed on the cover body 11 and face the first cover plate 12, the first cover plate 12 closes the open places of both the air inlet channel 60 and the air outlet channel 20 facing the first cover plate 12, so as to facilitate the formation of the air inlet channel 60 and the air outlet channel 20 on the structure main body 10. The first pump chamber 51 is surrounded by the first cover plate 12, the middle plate 13 and the vibrator 200, and the air outlet 511 and the air inlet 512 of the first pump chamber 51 are both located on the middle plate 13. The second pump chamber 52 is surrounded by the vibrator 200 and the second cover plate 14, and the air outlet 521 and the air inlet 522 of the second pump chamber 52 are both located on the second cover plate 14. Specifically, the middle plate 13 can be a plastic piece, so as to be formed by injection molding and have insulation performance, for isolating the electrical connection between the electrode lug 221 and the vibrating plate 210; the cover body 11, the first cover plate 12 and the second cover plate 14 can be plastic pieces, such as PPS fiber or nylon fiber, so as to be formed by injection molding.
[0049] It should be noted that, when the structure main body 10 sequentially comprises the cover body 11, the first cover plate 12, the hollow middle plate 13 and the second cover plate 14 fixed together in layers along the first direction, correspondingly, the outer connecting part 211 of the vibrating plate 210 is sealingly clamped between the middle plate 13 and the second cover plate 14.
[0050] In combination Figure 1 to Figure 13 The working of the piezoelectric air pump 1000 will be described as follows:
[0051] In the process of the deformation displacement of the vibrator 200 towards the direction of reducing the volume of the first pump chamber 51 (i.e. in the process of the first half cycle), the deformed vibrator 200 reduces the volume of the first pump chamber 51, so that the gas in the first pump chamber 51 flows into the external discharge channel 30 through the air outlet channel 20 corresponding to the first pump chamber 51 (for example, but not limited to the left air outlet channel in Figure 6 , so that the gas entering the external discharge channel 30 is converted into high-inertia and high-flow-rate gas, which is pumped out to the air bag of the sphygmomanometer, and the flow direction of the gas is shown by the dashed line in Figure 6 . At the same time, in the first half cycle, the volume of the second pump chamber 52 is expanded to form a negative pressure, so that the external gas enters the second pump chamber 52 through the air inlet channel 60, and the flow direction of the gas is shown by the dashed line in Figure 9 .
[0052] In the process of the deformation displacement of the vibrator 200 towards the direction of reducing the volume of the second pump chamber 52 (i.e. in the process of the second half cycle), the deformed vibrator 200 reduces the volume of the second pump chamber 52, so that the gas in the second pump chamber 52 flows into the external discharge channel 30 through the air outlet channel 20 corresponding to the second pump chamber 52 (for example, but not limited to the right air outlet channel in Figure 6into the outlet passage 30, so that the gas entering the outlet passage 30 is converted into high-inertia, high-flow-rate gas, which is pumped out to the airbag of the sphygmomanometer, and the flow direction of the gas is shown by the dotted line in Fig. 2. Figure 7 Meanwhile, in the first half cycle, the volume of the first pump chamber 51 is expanded to form a negative pressure, so that the ambient gas enters the first pump chamber 51 through the inlet passage 60, and the flow direction of the gas is shown by the dotted line in Fig. 2. Figure 10
[0053] Please refer to Figure 14 to Figure 19 The piezoelectric gas pump 1000' with the gas outlet structure 100' of the second embodiment has basically the same structure as the piezoelectric gas pump 1000 with the gas outlet structure 100 of the first embodiment, and the difference is as follows:
[0054] (1) In the piezoelectric gas pump 1000', the structure body 10' contains, in the first direction, the cover 11', the first cover plate 12', the first end cover 13', the hollow first middle plate 14', the hollow second middle plate 15', the second end cover 16', and the second cover plate 17' stacked and fixed together in sequence; the vibrator 210 is clamped and fixed in a sealing fit in the first middle plate 14' and the second middle plate 15'; correspondingly, the outlet passage 30 penetrates through the cover 11', the gas outlet passage 20 is enclosed by the cover 11' and the first cover plate 12', and the cone 40 is located on the first cover plate 12'; the inlet passage 60 connected to the first pump chamber 51 is enclosed by the first cover plate 12' and the first end cover 13', and the inlet passage 60 connected to the second pump chamber 52 is enclosed by the second end cover 16' and the second cover plate 17'; the first pump chamber 51 is enclosed by the first end cover 13', the first middle plate 14', and the vibrator 200, the gas inlet 512 of the first pump chamber 51 is located on the first end cover 13', and the gas outlet 511 of the first pump chamber 51 is located on the first middle plate 14'; the second pump chamber 52 is enclosed by the vibrator 200, the second middle plate 15', and the second end cover 16', the gas inlet 522 of the second pump chamber 52 is located on the second end cover 16', and the gas outlet 521 of the second pump chamber 52 is located on the second middle plate 15'. Specifically, in the piezoelectric gas pump 1000', the second middle plate 15' is a metal piece, so that the second middle plate 15' has good heat dissipation performance to dissipate heat outward; alternatively, in the piezoelectric gas pump 1000', as an example, the second middle plate 15' is arranged outwardly protruding relative to the cover 11', the first cover plate 12', the first end cover 13', the first middle plate 14', the second end cover 16', and the second cover plate 17', so as to obtain better heat dissipation effect. Figure 14
[0055] In the piezoelectric air pump 1000, the structure body 10 comprises, in sequence along the first direction, the cover 11, the first cover plate 12, the hollow middle plate 13 and the second cover plate 14 which are fixed together in layers. The vibrator 200 is clamped between the middle plate 13 and the second cover plate 14 in a sealing fit. The outer discharge passage 30 penetrates the cover 11. The cone 40 is located on the first cover plate 12. The air inlet passage 60 and the air outlet passage 20 are jointly enclosed by the cover 11 and the first cover plate 12. The first pump chamber 51 is jointly enclosed by the first cover plate 12, the middle plate 13 and the vibrator 200. The air outlet port 511 and the air inlet port 512 of the first pump chamber 51 are both located on the middle plate 13. The second pump chamber 52 is jointly enclosed by the vibrator 200 and the second cover plate 14. The air outlet port 521 and the air inlet port 522 of the second pump chamber 52 are both located on the second cover plate 14.
[0056] (2) In the piezoelectric air pump 1000`, the structure body 10` is further provided with the outer inlet passage 70. Correspondingly, the outer inlet passage 70 is in communication with the air inlet passage 60.
[0057] In the piezoelectric air pump 1000, the air inlet passage 60 is directly exposed to the outside, so the structure body 10 is not provided with the outer inlet passage 70.
[0058] In addition to the above differences, the other two are the same, so here is not repeated.
[0059] Compared with the prior art, by means of the first sawtooth 21 which is arranged on the opposite two passage side walls of the air outlet passage 20 and protrudes in the air outlet passage 20 in the direction of approaching the outer discharge passage 30, the first sawtooth 21 on the same passage side wall of the air outlet passage 20 is arranged in a plurality of positions which are spaced from each other, the first sawtooth 21 has the first outward protruding tooth surface 211 and the first inward recessed tooth surface 212, and in the adjacent two first sawteeth 21 on the same passage side wall of the air outlet passage 20, the first outward protruding tooth surface 211 of one first sawtooth 21 and the first inward recessed tooth surface 212 of the other first sawtooth 21 jointly enclose a first rotation cavity 213, the design is to, when the gas flows reversely from the outer discharge passage 30 to the air outlet passage 20, according to the Coanda effect, the fluid has the wall attachment effect, under the wall attachment effect of the gas, the main gas flows along the tooth wall on both sides of the air outlet passage 20, the gas on one side flows reversely along the air outlet passage 20, and the gas on the other side enters the first rotation cavity 213 to form the reverse flow which is opposite to the reverse flow, the two gases interfere with each other to reduce the reverse flow speed. When the reverse flow pressure is greater and the gas flow speed is faster, the reverse resistance is also greater, so that the purpose of “canceling the mechanical check valve, avoiding the aging loss of the mechanical check valve and the low requirement for the material, and also having the advantage of high response frequency” is achieved.
[0060] It should be noted that the direction indicated by the arrow A in the drawing is the first direction, and the direction perpendicular to the first direction is the horizontal direction; in addition, the air inlet channel 60 and the air outlet channel 20 also extend along the horizontal direction. In addition, in the Figure 5 to Figure 10 As an example, the outer exhaust channel 30 can also include a second cylindrical cavity 34 in communication with the first circular cavity 31, the second cylindrical cavity 34 and the first cylindrical cavity 32 are arranged back to center with the first circular cavity 31, and the cavity diameter of the second cylindrical cavity 34 is greater than that of the first cylindrical cavity 32; obviously, according to actual needs, the second cylindrical cavity 34 can be deleted, so it is not limited to be shown. Figure 5 to Figure 10
[0061] The above only discloses the preferred embodiment of the present application, and cannot limit the scope of the present application, so equivalent changes made according to the claims of the present application all belong to the scope covered by the present application.
Claims
1. An air outlet structure comprising a structure body, an air outlet passage and an exhaust passage formed in the structure body, wherein the exhaust passage communicates with the air outlet passage, characterized in that, The opposite two channel side walls of the air outlet channel have first sawteeth arranged staggeredly and protruding obliquely in the air outlet channel towards the direction close to the air outlet channel, the first sawteeth on the same channel side wall of the air outlet channel are multiple and spaced apart from each other, and the first sawteeth have outward protruding first outer tooth surfaces and inward recessed first inner tooth surfaces; in the adjacent two first sawteeth on the same channel side wall of the air outlet channel, the first outer tooth surface of one first sawtooth and the first inner tooth surface of the other first sawtooth jointly enclose a first rotation cavity.
2. The air outlet structure according to claim 1, characterized in that, The air outlet channel sequentially comprises a first circular cone cavity, a first circular cylinder cavity and a second circular cone cavity along a first direction, the first circular cylinder cavity is in communication with the cavity top of both the first circular cone cavity and the second circular cone cavity, the cavity diameter of the first circular cylinder cavity is smaller than the size of the cavity bottom of both the first circular cone cavity and the second circular cone cavity, and the structure body is provided with a cone protruding into and cooperating with the second circular cone cavity.
3. The air outlet structure according to claim 2, characterized in that, The side wall surface of the cone is fitted with the side cavity wall surface of the second circular cone cavity, and the air outlet channel further penetrates the side wall surface of the cone or the side cavity wall surface of the second circular cone cavity.
4. A piezoelectric pump comprising a vibrator, characterized by The piezoelectric air pump further comprises the air outlet structure according to any one of claims 1 to 3, a cavity is formed in the structure body, the vibrator is transversely arranged in the cavity and is in sealed connection with the structure body, the vibrator divides the cavity into a first pump chamber and a second pump chamber, and the first pump chamber and the second pump chamber are in communication with the air outlet channel through the air outlet channel.
5. The piezoelectric gas pump according to claim 4, wherein, The air outlet channel is oppositely arranged with respect to the air outlet channel, one air outlet channel is in communication with the air outlet channel and the exhaust port of the first pump chamber, and the other air outlet channel is in communication with the air outlet channel and the exhaust port of the second pump chamber.
6. The piezoelectric gas pump according to claim 4, wherein The structure body is further provided with an air inlet channel in communication with the first pump chamber and the second pump chamber, respectively, and the opposite two channel side walls of the air inlet channel have second sawteeth arranged staggeredly and protruding obliquely in the air inlet channel towards the direction close to the outlet of the air inlet channel.
7. The piezoelectric gas pump according to claim 6, characterized in that The second sawteeth on the same channel side wall of the air inlet channel are multiple and spaced apart from each other, and the second sawteeth have outward protruding second outer tooth surfaces and inward recessed second inner tooth surfaces; in the adjacent two second sawteeth on the same channel side wall of the air inlet channel, the second outer tooth surface of one second sawtooth and the second inner tooth surface of the other second sawtooth jointly enclose a second rotation cavity.
8. The piezoelectric gas pump according to claim 4, wherein, The vibrator comprises a vibrating plate and a piezoelectric ceramic sheet, the vibrating plate comprises an outer connecting part for sealed connection with the structure body, a flat part surrounded by the outer connecting part, and a corrugated suspension part connected between the flat part and the outer connecting part, and the piezoelectric ceramic sheet is fixed to the flat part.
9. The piezoelectric gas pump according to claim 6, wherein The structural body comprises, in sequence along the first direction, a cover, a first cover plate, a hollow middle plate, and a second cover plate fixed together in layers, and the vibrator is clamped between the middle plate and the second cover plate in sealing fit; the air outlet channel penetrates through the cover, the air inlet channel and the air outlet channel are jointly enclosed by the cover and the first cover plate; the first pump chamber is jointly enclosed by the first cover plate, the middle plate, and the vibrator, and the second pump chamber is jointly enclosed by the vibrator and the second cover plate; the air inlet and the air outlet of the first pump chamber are located on the middle plate, and the air inlet and the air outlet of the second pump chamber are located on the second cover plate.
10. The piezoelectric gas pump according to claim 6, wherein The structural body comprises, in sequence along the first direction, a cover, a first cover plate, a first end cover, a hollow first middle plate, a hollow second middle plate, a second end cover, and a second cover plate fixed together in layers; the vibrator is clamped between the first middle plate and the second middle plate in sealing fit; the air outlet channel penetrates through the cover, and the air outlet channel is jointly enclosed by the cover and the first cover plate; the air inlet channel connected with the first pump chamber is jointly enclosed by the first cover plate and the first end cover, and the air inlet channel connected with the second pump chamber is jointly enclosed by the second end cover and the second cover plate; the first pump chamber is jointly enclosed by the first end cover, the first middle plate, and the vibrator, and the second pump chamber is jointly enclosed by the vibrator, the second middle plate, and the second end cover; the air inlet of the first pump chamber is located on the first end cover, and the air outlet of the first pump chamber is located on the first middle plate; the air inlet of the second pump chamber is located on the second end cover, and the air outlet of the second pump chamber is located on the second middle plate.