Piezoelectric vibrator and fluid pump

Abstract

The present invention relates to the field of fluid control technology, and in particular to a piezoelectric vibrator and a fluid pump, comprising a flexible support plate, a piezoelectric ceramic sheet, and a frequency adjustment plate, wherein the flexible support plate comprises a central vibrating portion, a flexible hinge portion, and an edge fixing portion, wherein the piezoelectric ceramic sheet and the frequency adjustment plate are respectively arranged on two opposite surfaces of the central vibrating portion, wherein the inner edge of the edge fixing portion and the outer edge of the central vibrating portion are fixedly connected by a flexible hinge portion, wherein the flexible hinge portion is in the shape of a closed frame, and a hole portion is provided on the flexible hinge portion, wherein the centers of the plurality of through holes are all placed at the center position of the width of the flexible hinge portion. The piezoelectric vibrator is connected by providing a frame-shaped flexible hinge between the central vibrating portion and the edge fixing portion, and a through hole is provided circumferentially on the frame-shaped flexible hinge, which not only ensures the connection strength and enables the central vibrating portion to stably follow the high-frequency vibration of the piezoelectric element, but also ensures the gas circulation between the upper and lower cavities, thereby effectively improving the service life of the fluid pump.

Description

Technical Field

[0001] The present invention relates to the field of fluid control technology, and in particular to a piezoelectric vibrator and a fluid pump. Background Art

[0002] With the development of microfluidics technology, new methods and devices for microfluidic control have been explored. Traditional gas delivery methods are limited by bulk, complexity, and operability. Piezoelectric micropumps, with their advantages of small size, fast response, and precise control, have important applications in fields such as environmental monitoring, gas detection, and biosensing. However, traditional gas sensors require external devices such as pumps or compressors to supply and remove gas. Piezoelectric micropumps, as tiny, efficient, and integrable gas delivery devices, can meet the gas supply requirements of micro gas sensors. In the medical field, gas delivery is a critical step in many treatment and diagnostic procedures. For example, tiny gas pumps can be used to deliver oxygen, drugs, or gas mixtures to a patient's respiratory system. Compared with traditional gas delivery methods, piezoelectric micropumps offer advantages such as small size, fast response, and low noise, and can provide more precise and personalized gas delivery.

[0003] A search revealed patent publication number CN116677592A, which discloses a high-flow, side-inlet piezoelectric micropump. The micropump comprises a sequentially stacked sealing layer, an inlet layer, a vibration substrate layer, a housing layer, and a vibration layer secured to the vibration substrate layer. The vibration substrate layer comprises an edge fixing portion, an elastic connector, and a central vibration portion. The edge of the central hole in the edge fixing portion is connected to the outer edge of the central vibration portion via an elastic connector. However, in actual use, it has been found that the central vibration portion experiences significant fluctuations in response to the high-frequency vibrations generated by the piezoelectric element. The four circumferential connection points alone clearly cannot guarantee the connection strength between the central vibration portion and the edge fixing portion. The central vibration portion can easily break at high amplitudes, thus affecting the service life of the piezoelectric vibrator and the micropump. Summary of the Invention

[0004] In order to solve the problem that the central vibrating part and the edge fixing part of the existing piezoelectric vibrator are only connected by point through a connecting strip, resulting in poor connection strength, the present invention provides a piezoelectric vibrator and a fluid pump, which are connected by arranging a frame-shaped flexible hinge between the central vibrating part and the edge fixing part, and a through hole is opened circumferentially on the frame-shaped flexible hinge, which not only ensures the connection strength and enables the central vibrating part to stably follow the high-frequency vibration of the piezoelectric element, but also ensures the gas circulation in the upper and lower cavities.

[0005] The present invention provides a piezoelectric vibrator comprising a flexible support plate, a piezoelectric ceramic sheet, and a frequency adjustment plate. The flexible support plate comprises a central vibrating portion, a flexible hinge portion, and an edge fixing portion. The piezoelectric ceramic sheet and the frequency adjustment plate are respectively disposed on two opposing surfaces of the central vibrating portion. The inner edge of the edge fixing portion and the outer edge of the central vibrating portion are fixedly connected via a flexible hinge portion. The flexible hinge portion is in the shape of a closed frame and has a hole formed therein. The closed frame-shaped flexible hinge portion connects the edge fixing portion and the central vibrating portion, effectively reducing the vibration resistance of the edge fixing portion to the central vibrating portion while ensuring connection strength and extending service life.

[0006] Furthermore, the hole portion includes a plurality of through holes circumferentially arranged on the flexible hinge portion, the centers of the plurality of through holes are all located at the center of the width of the flexible hinge portion. The through holes are opened at the center of the hinge portion so that the hinge portions on both sides of the through holes are evenly stressed.

[0007] Furthermore, a first support washer is disposed beneath the flexible support plate. The first support washer comprises a first outer frame and a plurality of first support portions disposed at the inner edge of the first outer frame. The plurality of first support portions are circumferentially arranged on the first outer frame at equal intervals, and the first support portions are disposed corresponding to the through-holes. The first support portions support the holes in the flexible support plate from below, reducing the vibration amplitude at the holes and thereby minimizing the risk of cracking.

[0008] Furthermore, the thickness of the first support portion is greater than that of the first outer frame, and the lower surface of the first support portion is flush with the lower surface of the first outer frame. A step 1 is formed on the connecting surface between the first support portion and the first outer frame for receiving the edge fixing portion of the flexible support plate. Step 1 facilitates the mating installation of the first support washer and the flexible support plate.

[0009] Furthermore, a second support washer is disposed above the flexible support plate. The second support washer comprises a second outer frame and a plurality of second support portions disposed on the inner edge of the second outer frame. The plurality of second support portions are circumferentially arranged at equal intervals on the second outer frame, and the second support portions are disposed corresponding to the through-holes. The second support portions support the holes in the flexible support plate from above, further reducing the vibration amplitude at the holes and minimizing the risk of cracking.

[0010] Furthermore, the thickness of the second support portion is greater than that of the second outer frame, and the upper surface of the second support portion is flush with the upper surface of the second outer frame. A second step is formed on the connecting surface of the second support portion and the second outer frame for receiving the edge fixing portion of the flexible support plate. This second step facilitates the mating installation of the second support washer and the flexible support plate.

[0011] Furthermore, the first and second support portions are square, trapezoidal, or semicircular in shape, and each has a clearance hole opposite the through hole. The width of the first and second support portions is greater than half the width of the flexible hinge portion, but less than the width of the flexible hinge portion. By providing support portions of specific dimensions, the holes in the flexible support plate are supported while ensuring that the flexible hinge portion follows the normal fluctuations of the piezoelectric element.

[0012] A fluid pump includes a pump body and a piezoelectric vibrator. While ensuring the amplitude of the piezoelectric vibrator, the connection strength of the vibrator is increased, which can extend the service life of the pump body to a certain extent.

[0013] Furthermore, the pump body includes a bottom shell and an upper cover. The upper surface of the bottom shell is provided with a mounting ring groove that can accommodate the first outer frame, the edge fixing portion, and the second outer frame. The lower surface of the upper cover is provided with a mounting boss that matches the mounting ring groove, thereby confining the first outer frame, the edge fixing portion, and the second outer frame between the bottom shell and the upper cover. The flexible support plate is disposed within the pump body via the edge fixing portion and divides the interior of the pump body into an upper cavity and a lower cavity. The upper and lower cavities are connected via a hole in the flexible hinge portion. The piezoelectric vibrator and the upper and lower washers are fixed within the pump body through the cooperation of the mounting ring groove and the mounting boss.

[0014] Furthermore, the upper cover has a fluid outlet connected to the upper cavity, and the bottom shell has a fluid inlet connected to the lower cavity. Both the fluid outlet and the fluid inlet are equipped with one-way valves. The vibration of the piezoelectric vibrator changes the volume of the upper and lower cavities, thereby achieving fluid intake and discharge.

[0015] The beneficial effects of the present invention are:

[0016] The present invention provides a piezoelectric vibrator and a fluid pump, which are connected by arranging a flexible hinge part in the shape of a closed frame between a central vibrating part and an edge fixing part, and a through hole connecting the upper and lower cavities is opened circumferentially on the flexible hinge, which not only ensures the connection strength of the vibrator, so that the central vibrating part stably follows the high-frequency vibration of the piezoelectric element, but also ensures the gas circulation in the upper and lower cavities; by adding gaskets on the upper and lower sides of the flexible support plate, the support part of the inner edge of the gasket is used to support the position near the hole part on the flexible hinge part, so as to reduce the amplitude near the hole part, thereby reducing the risk of cracking of the hole part under high-frequency vibration, and extending the service life of the vibrator and the pump body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0018] Figure 1 This is the assembly diagram of the piezoelectric vibrator;

[0019] Figure 2 This is an exploded diagram of a piezoelectric vibrator;

[0020] Figure 3 It is a schematic diagram of the upper surface of the piezoelectric vibrator and the supporting washer;

[0021] Figure 4 It is a schematic diagram of the bottom surface of the piezoelectric vibrator and the supporting washer;

[0022] Figure 5 Schematic diagram of the coordination between the flexible support plate and support parts of different shapes;

[0023] Figure 6 It is a schematic diagram of the bottom shell and the upper cover from the first angle;

[0024] Figure 7 This is a second angle diagram of the bottom shell and the upper cover;

[0025] Figure 8 It is a schematic diagram of the external structure of the pump body;

[0026] Figure 9 It is a schematic diagram of the internal structure of the pump body;

[0027] Figure 10 yes Figure 9 A magnified view of point A in the figure;

[0028] In the figure, 1. flexible support plate, 11. central vibration part, 12. flexible hinge part, 121. hole part, 122. avoidance hole, 13. edge fixing part, 2. piezoelectric ceramic piece, 3. frequency adjustment plate, 4. first support washer, 41. first outer frame, 42. first support part, 43. step one, 5. second support washer, 51. second outer frame, 52. second support part, 53. step two, 6. pump body, 61. upper cover, 611. mounting boss, 612. fluid outlet, 62. bottom shell, 621. mounting ring groove, 622. fluid inlet, 63. one-way valve, 64. upper cavity, 65. lower cavity. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] In order to ensure the connection strength between the central vibrating part 11 and the edge fixing part 13 while reducing the vibration resistance of the edge fixing part 13 to the central vibrating part 11, a piezoelectric vibrator is designed, such as Figure 1 and 2 As shown, it includes a flexible support plate 1, a piezoelectric ceramic piece 2 and a frequency adjustment plate 3. The flexible support plate 1 includes a central vibration part 11, a flexible hinge part 12 and an edge fixing part 13. The piezoelectric ceramic piece 2 and the frequency adjustment plate 3 are respectively arranged on two opposite surfaces of the central vibration part 11. The inner edge of the edge fixing part 13 and the outer edge of the central vibration part 11 are fixedly connected by the flexible hinge part 12. The flexible hinge part 12 is in a closed frame shape and has a hole 121.

[0031] The edge fixing portion 13 is fixedly mounted within the pump body 6. During operation, the edge fixing portion 13 does not vibrate. The edge fixing portion 13 is made of stainless steel. The piezoelectric ceramic disc 2 is mounted at the center of the central vibrating portion 11. The central vibrating portion 11 will generate high-frequency vibrations along with the piezoelectric ceramic disc 2, thereby exhibiting a curved state. The central vibrating portion 11 is configured to correspond to the shape of the piezoelectric ceramic disc 2 and is not limited to a square, regular polygon, rectangle, or circle. The flexible hinge portion 12 is configured to form a corresponding frame shape according to the shape of the central vibrating portion 11. The frame-shaped connection replaces the traditional point-to-point connection method, thereby increasing the connection strength between the central vibrating portion 11 and the edge fixing portion 13 while reducing the constraint of the central vibrating portion 11 by the edge fixing portion 13. The flexible hinge is generally made of metal, but can also be non-metallic, so that the central vibrating portion 11 can vibrate up and down along with the piezoelectric ceramic disc 2. A piezoelectric ceramic sheet 2 is bonded to one side of the central vibrating part 11, and a frequency adjustment plate 3 is bonded to the other side. The piezoelectric ceramic sheet 2 and the frequency adjustment plate 3 are both adapted to the shape of the central vibrating part 11. The frequency adjustment plate 3 is used to adjust the vibration frequency, form piezoelectric ceramic stress, and prevent it from being damaged. When alternating current is passed through the piezoelectric ceramic sheet 2, the piezoelectric ceramic sheet 2 drives the central vibrating part 11 to generate high-frequency vibration, thereby presenting a continuous bending state, thereby changing the volume of the upper cavity 64 and the lower cavity 65 in the pump body 6, thereby realizing the suction and discharge of the fluid.

[0032] The hole portion 121 includes several through holes circumferentially arranged on the flexible hinge portion 12. The through holes are arranged in an area outside the flexible support plate 1 where the piezoelectric ceramic piece 2 is installed. Specifically, the centers of the several through holes are placed at the center position of the width of the flexible hinge portion 12 to avoid affecting the vibration of the piezoelectric ceramic piece 2. The uniform distribution of the through holes helps to achieve uniform circulation of the fluid in the pump body 6, further improving the working efficiency and stability of the fluid pump.

[0033] like Figure 3 and 4 As shown, the core of this technical solution is that, in order to prevent the flexible hinge at the through-hole from cracking under high-frequency vibration, a first support washer 4 is provided below the flexible support plate 1. The first support washer 4 includes a first outer frame 41 and a plurality of first support portions 42 provided at the inner edge of the first outer frame 41. The plurality of first support portions 42 are circumferentially arranged on the first outer frame 41 at equal intervals, and the first support portions 42 are provided corresponding to the through-holes. The first outer frame 41 is used to fix the first support portions 42, which support the through-hole of the flexible hinge portion 12 from the bottom, thereby reducing the vibration amplitude of the flexible hinge at the through-hole to a certain extent, thereby improving fatigue strength, reducing the risk of cracking at the opening, and extending the service life of the vibrator.

[0034] like Figure 9 and 10 As shown, to facilitate proper assembly, the thickness of the first support portion 42 is greater than that of the first outer frame 41. The lower surface of the first support portion 42 is flush with the lower surface of the first outer frame 41. A step 43 is formed on the connecting surface between the first support portion 42 and the first outer frame 41 for retaining the edge fixing portion 13 of the flexible support plate 1. During installation, the first support washer 4 is first placed within the mounting ring groove 621 of the bottom shell 62. The flexible support plate 1 is then placed above the support washer, so that the edge fixing portion 13 of the flexible support plate 1 is precisely retained on the step 43. At this point, the edge fixing portion 13 is restrained by the step 43 within the mounting ring groove 621, thereby ensuring proper assembly.

[0035] like Figure 3 and 4 As shown, to further prevent the flexible hinge at the through-hole from cracking under high-frequency vibration, a second support washer 5 is also disposed above the flexible support plate 1. The second support washer 5 comprises a second outer frame 51 and a plurality of second support portions 52 disposed at the inner edge of the second outer frame 51. The plurality of second support portions 52 are circumferentially arranged on the second outer frame 51 at equal intervals, and the second support portions 52 are disposed corresponding to the through-holes. The second outer frame 51 is used to secure the second support portions 52. The second support portions 52 and the first support portions 42 respectively support the through-hole of the flexible hinge portion 12 from above and below, significantly reducing the vibration amplitude of the flexible hinge at the through-hole, thereby improving fatigue strength, reducing the risk of cracking at the opening, and extending the service life of the vibrator.

[0036] like Figure 9 and 10As shown, in order to facilitate assembly, the thickness of the second support portion 52 is greater than the thickness of the second outer frame 51, the upper surface of the second support portion 52 is flush with the upper surface of the second outer frame 51, and a step 2 53 is formed on the connecting surface of the second support portion 52 and the second outer frame 51 for clamping the edge fixing portion 13 of the flexible support plate 1. After installing the first support washer 4 and the flexible support plate 1 into the mounting ring groove 621 in sequence, the second support washer 5 is placed above the flexible support plate 1 so that the step 2 53 of the second support washer 5 is clamped at the edge fixing portion 13 on the periphery of the flexible support plate 1. At this time, the step 2 53 of the second support washer 5 cooperates with the step 1 43 of the first support washer 4 to stably restrict the edge fixing portion 13 in the mounting ring groove 621, thereby ensuring the installation stability of the piezoelectric vibrator. Not only that, the edge fixing portion 13 is restricted to the periphery of step 1 43 and step 2 53, which can also reduce the lateral vibration displacement of the flexible support plate 1 to a certain extent. In addition, the uniform force deformation of the frame-shaped flexible hinge portion 12 can ensure that the central vibration portion 11 is always in the middle of the cavity to work, thereby ensuring the stability of the pump body 6.

[0037] like Figure 5 As shown, while providing stable support for the flexible hinge at the through hole, in order not to affect the vibration of the hinge, the first support portion 42 and the second support portion 52 are square, trapezoidal or semicircular, and the width of the first support portion 42 and the second support portion 52 is greater than half the width of the flexible hinge portion 12, and less than the width of the flexible hinge portion 12, so that the support portion does not completely cover the flexible hinge, and while providing support, it does not hinder the vibration of the central vibration portion 11.

[0038] In order to adjust the amplitude of the flexible hinge at the through hole, the thickness of the support part or the distance between the support part and the through hole can be adjusted. The thicker the support part, the greater the restraining resistance to vibration and the smaller the amplitude; the thinner the support part, the smaller the restraining resistance to vibration and the larger the amplitude; the smaller the distance between the support part and the through hole, the greater the restraining resistance to vibration and the smaller the amplitude; the larger the distance between the support part and the through hole, the smaller the restraining resistance to vibration and the larger the amplitude.

[0039] While providing stable support for the flexible hinge at the through hole, in order not to affect the normal circulation of the fluid in the pump body 6, the first support part 42 and the second support part 52 are both provided with avoidance holes 122 opposite to the through hole. The avoidance holes 122 are opened corresponding to the through hole and do not affect the circulation of the fluid between the upper cavity 64 and the lower cavity 65.

[0040] like Figure 6-8As shown, a fluid pump includes a pump body 6 and a piezoelectric vibrator. The pump body 6 includes a bottom shell 62 and an upper cover 61. The upper surface of the bottom shell 62 is provided with a mounting ring groove 621 that can accommodate the first outer frame 41, the edge fixing portion 13 and the second outer frame 51. The lower surface of the upper cover 61 is provided with a mounting boss 611 that is compatible with the mounting ring groove 621, which confines the first outer frame 41, the edge fixing portion 13 and the second outer frame 51 between the bottom shell 62 and the upper cover 61. The flexible support plate 1 is set in the pump body 6 through the edge fixing portion 13, and divides the interior of the pump body 6 into an upper cavity 64 and a lower cavity 65. The upper cavity 64 and the lower cavity 65 are connected through the hole portion 121 on the flexible hinge portion 12.

[0041] Through the cooperation of the mounting boss 611 of the upper cover 61 and the mounting ring groove 621 of the bottom shell 62, the piezoelectric vibrator is stably installed in the pump body 6. The piezoelectric ceramic piece 2 vibrates when energized, changing the volume of the upper cavity 64 and the lower cavity 65 in the pump body 6, thereby realizing the suction and discharge of the fluid.

[0042] The upper cover 61 defines a fluid outlet 612 communicating with the upper chamber 64, and the bottom shell 62 defines a fluid inlet 622 communicating with the lower chamber 65. Both the fluid outlet 612 and the fluid inlet 622 are provided with a one-way valve 63. The one-way valves 63 provided at the fluid outlet 612 and the fluid inlet 622 ensure one-way gas flow, thereby improving the pump's operating efficiency.

[0043] The above description is only illustrative of the present invention and not restrictive. Those skilled in the art will understand that many modifications, changes or equivalents may be made without departing from the spirit and scope defined by the appended claims, but all of them will fall within the scope of protection of the present invention.

Claims

1. A piezoelectric vibrator, characterized in that: The invention comprises a flexible support plate (1), a piezoelectric ceramic piece (2) and a frequency adjustment plate (3), wherein the flexible support plate (1) comprises a central vibration portion (11), a flexible hinge portion (12) and an edge fixing portion (13), the piezoelectric ceramic piece (2) and the frequency adjustment plate (3) are respectively arranged on two opposite surfaces of the central vibration portion (11), the inner edge of the edge fixing portion (13) and the outer edge of the central vibration portion (11) are fixedly connected via the flexible hinge portion (12), the flexible hinge portion (12) is in a closed frame shape, and a hole portion (121) is provided on the flexible hinge portion (12); The hole portion (121) comprises a plurality of through holes circumferentially arranged on the flexible hinge portion (12); A first supporting washer (4) is provided below the flexible supporting plate (1), the first supporting washer (4) comprising a first outer frame (41) and a plurality of first supporting portions (42) provided at the inner edge of the first outer frame (41), the first supporting portions (42) being provided corresponding to the through holes.

2. The piezoelectric vibrator according to claim 1, characterized in that: The thickness of the first support portion (42) is greater than the thickness of the first outer frame (41); the lower surface of the first support portion (42) is flush with the lower surface of the first outer frame (41); and a step (43) for clamping the edge fixing portion (13) of the flexible support plate (1) is formed on the connecting surface between the first support portion (42) and the first outer frame (41).

3. The piezoelectric vibrator according to claim 1, wherein: A second supporting washer (5) is provided above the flexible supporting plate (1), the second supporting washer (5) comprising a second outer frame (51) and a plurality of second supporting portions (52) provided at the inner edge of the second outer frame (51), the plurality of second supporting portions (52) being circumferentially provided at equal intervals on the second outer frame (51), and the second supporting portions (52) being provided corresponding to the through holes.

4. The piezoelectric vibrator according to claim 3, wherein: The thickness of the second support portion (52) is greater than the thickness of the second outer frame (51), the upper surface of the second support portion (52) is flush with the upper surface of the second outer frame (51), and a second step (53) for clamping the edge fixing portion (13) of the flexible support plate (1) is formed on the connecting surface of the second support portion (52) and the second outer frame (51).

5. The piezoelectric vibrator according to claim 3, characterized in that: The first support portion (42) and the second support portion (52) are square, trapezoidal or semicircular, and each of the first support portion (42) and the second support portion (52) is provided with an avoidance hole (122) opposite to the through hole. The width of the first support portion (42) and the second support portion (52) is greater than half the width of the flexible hinge portion (12) and less than the width of the flexible hinge portion (12).

6. A fluid pump, characterized in that: It comprises a pump body (6) and the piezoelectric vibrator according to any one of claims 1 to 5.

7. A fluid pump according to claim 6, characterized in that: The pump body (6) comprises a bottom shell (62) and an upper cover (61); the upper plane of the bottom shell (62) is provided with a mounting ring groove (621) for accommodating the first outer frame (41), the edge fixing portion (13) and the second outer frame (51); the lower plane of the upper cover (61) is provided with a mounting boss (611) adapted to the mounting ring groove (621), so as to restrict the first outer frame (41), the edge fixing portion (13) and the second outer frame (51) between the bottom shell (62) and the upper cover (61); the flexible support plate (1) is arranged in the pump body (6) through the edge fixing portion (13), and divides the interior of the pump body (6) into an upper cavity (64) and a lower cavity (65); the upper cavity (64) and the lower cavity (65) are connected through a hole portion (121) on the flexible hinge portion (12).

8. A fluid pump according to claim 7, characterized in that: The upper cover (61) is provided with a fluid outlet (612) communicating with the upper cavity (64), and the bottom shell (62) is provided with a fluid inlet (622) communicating with the lower cavity (65). Both the fluid outlet (612) and the fluid inlet (622) are provided with a one-way valve (63).

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