Piezoelectric vibrator and fluid pump

Abstract

The invention relates to the technical field of fluid control, in particular to a piezoelectric vibrator and a fluid pump, the piezoelectric vibrator comprises a flexible supporting plate, a piezoelectric ceramic piece and a frequency adjusting plate, the flexible supporting plate comprises a center vibration part, a flexible hinge part and an edge fixing part, and the piezoelectric ceramic piece and the frequency adjusting plate are arranged on two opposite faces of the center vibration part respectively; the inner edge of the edge fixing part is fixedly connected with the outer edge of the center vibration part through a flexible hinge part, the flexible hinge part is in a closed frame shape, a hole part is formed in the flexible hinge part, and the circle centers of the through holes are all arranged at the center position of the width of the flexible hinge part. According to the piezoelectric vibrator, the frame-shaped flexible hinge is arranged between the center vibration part and the edge fixing part for connection, and the through holes are formed in the frame-shaped flexible hinge in the circumferential direction, so that the connection strength is guaranteed, the center vibration part stably follows the piezoelectric element for high-frequency vibration, and gas circulation of the upper cavity and the lower cavity is guaranteed; therefore, the service life of the fluid pump is effectively prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid control, 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 begun to be explored. Traditional gas delivery methods are limited by problems such as large size, complexity and operability, while piezoelectric micropumps have advantages such as small size, fast response and precise control. For example, micro gas sensors have important applications in environmental monitoring, gas detection and biosensing. However, traditional gas sensors require external devices such as pumps or compressors to supply and remove gas, while piezoelectric micropumps, as a tiny, efficient and integrable gas delivery device, can meet the gas supply requirements of micro gas sensors. In the medical field, gas delivery is an important part of many treatment and diagnosis processes. For example, tiny gas pumps can be used to deliver oxygen, drugs or gas mixtures to the patient's respiratory system. Compared with traditional gas delivery methods, piezoelectric micropumps have the characteristics of small size, fast response and low noise, and can provide more accurate and personalized gas delivery.

[0003] After searching, the patent with publication number CN116677592A discloses a piezoelectric micro pump with high flow rate and lateral air intake, including a sealing layer, an inlet layer, a vibration substrate layer, a shell layer, and a vibration layer fixed on the vibration substrate layer, the vibration substrate layer includes an edge fixing part, an elastic connector and a central vibration part, and the edge of the center hole of the edge fixing part is connected to the outer edge of the central vibration part by an elastic connector. However, in actual use, it is found that the central vibration part fluctuates greatly with the high-frequency vibration generated by the piezoelectric element. The connection strength between the central vibration part and the edge fixing part cannot be guaranteed by only four connection points arranged in the circumferential direction. The central vibration part is easy to break under a large amplitude, thereby affecting the service life of the piezoelectric vibrator and the micro pump. 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 point-connected by a connecting strip and the connection strength is poor, the present invention provides a piezoelectric vibrator and a fluid pump, which are connected by setting a frame-shaped flexible hinge between the central vibrating part and the edge fixing part, and opening a through hole circumferentially on the frame-shaped flexible hinge, which not only ensures the connection strength, 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, wherein the flexible support plate comprises a central vibration part, a flexible hinge part and an edge fixing part, the piezoelectric ceramic sheet and the frequency adjustment plate are respectively arranged on two opposite surfaces of the central vibration part, the inner edge of the edge fixing part and the outer edge of the central vibration part are fixedly connected by the flexible hinge part, the flexible hinge part is in a closed frame shape, and a hole part is provided on the flexible hinge part. The edge fixing part and the central vibration part are connected by the closed frame-shaped flexible hinge part, which effectively reduces the vibration resistance of the edge fixing part to the central vibration part, and can also ensure the connection strength and extend the service life.

[0006] Furthermore, the hole portion includes a plurality of through holes circumferentially arranged on the flexible hinge portion, and 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 provided below the flexible support plate, the first support washer comprises a first outer frame and a plurality of first support portions provided at the inner edge of the first outer frame, the plurality of first support portions are circumferentially provided on the first outer frame at equal intervals, and the first support portions are provided corresponding to the through holes. The hole portion on the flexible support plate is supported from below by the first support portions, so as to reduce the vibration amplitude at the hole portion and reduce the risk of cracking.

[0008] Furthermore, the thickness of the first support portion is greater than the thickness of the first outer frame, the lower surface of the first support portion is flush with the lower surface of the first outer frame, and a step 1 for clamping the edge fixing portion of the flexible support plate is formed on the connecting surface of the first support portion and the first outer frame. The step 1 facilitates the coordinated installation of the first support gasket and the flexible support plate.

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

[0010] Furthermore, the thickness of the second support portion is greater than the thickness of the second outer frame, the upper surface of the second support portion is flush with the upper surface of the second outer frame, and a second step for clamping the edge fixing portion of the flexible support plate is formed on the connecting surface of the second support portion and the second outer frame. The second step facilitates the coordinated installation of the second support washer and the flexible support plate.

[0011] Furthermore, the first support part and the second support part are square, trapezoidal or semicircular, and are provided with avoidance holes opposite to the through holes, and the widths of the first support part and the second support part are greater than half of the width of the flexible hinge part, and smaller than the width of the flexible hinge part. By setting the support part of a specific size, it is possible to support the hole portion of the flexible support plate and ensure that the flexible hinge part follows the normal fluctuation 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 plane of the bottom shell is provided with an installation ring groove that can accommodate the first outer frame, the edge fixing part and the second outer frame, the lower plane of the upper cover is provided with an installation boss that matches the installation ring groove, the first outer frame, the edge fixing part and the second outer frame are restricted between the bottom shell and the upper cover, the flexible support plate is arranged in the pump body through the edge fixing part, and the inside of the pump body is divided into an upper cavity and a lower cavity, and the upper cavity and the lower cavity are connected through the hole on the flexible hinge part. Through the cooperation of the installation ring groove and the installation boss, the piezoelectric vibrator and the upper and lower washers are fixed in the pump body.

[0014] Furthermore, the upper cover is provided with a fluid outlet connected to the upper cavity, the bottom shell is provided with a fluid inlet connected to the lower cavity, and both the fluid outlet and the fluid inlet are provided with a one-way valve. The volume of the upper cavity and the lower cavity is changed by the vibration of the piezoelectric vibrator to achieve fluid suction and discharge.

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

[0016] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementations of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. Figure 1 It is the assembly diagram of the piezoelectric vibrator; Figure 2 This is an exploded diagram of a piezoelectric vibrator; Figure 3 It is a schematic diagram of the upper surface of the piezoelectric vibrator and the supporting washer; Figure 4 is a schematic diagram of the lower surface of the piezoelectric vibrator and the supporting washer; Figure 5 is a schematic diagram of the cooperation between the flexible support plate and the support parts of different shapes; Figure 6 is a first angle schematic diagram of the bottom shell and the upper cover; Figure 7 is a second angle schematic diagram of the bottom shell and the upper cover; Figure 8 It is a schematic diagram of the external structure of the pump body; Fig. 9 It is a schematic diagram of the internal structure of the pump body; Fig.10 yes Fig. 9 A in the enlarged view; 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 sheet, 3. frequency adjustment plate, 4. first support gasket, 41. first outer frame, 42. first support part, 43. step one, 5. second support gasket, 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

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0018] 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 through the flexible hinge part 12. The flexible hinge part 12 is in a closed frame shape, and a hole part 121 is opened on the flexible hinge part 12.

[0019] The edge fixing part 13 is fixedly installed in the pump body 6. The edge fixing part 13 does not vibrate during operation. The edge fixing part 13 is made of stainless steel. The piezoelectric ceramic piece 2 is installed at the central position of the central vibration part 11. The central vibration part 11 will produce high-frequency vibration with the piezoelectric ceramic piece 2 and present a bending state. The central vibration part 11 is set to correspond to the shape of the piezoelectric ceramic piece 2 and is not limited to a square, a regular polygon, a rectangle or a circle. The flexible hinge part 12 is set to a corresponding frame shape according to the shape of the central vibration part 11. The frame-shaped connection replaces the traditional point-to-point connection method to improve the connection strength between the central vibration part 11 and the edge fixing part 13 while reducing the constraint of the central vibration part 11 by the edge fixing part 13. The flexible hinge is generally metal, but can also be non-metallic, so that the central vibration part 11 can vibrate up and down with the piezoelectric ceramic piece 2. A piezoelectric ceramic sheet 2 is bonded to one side of the central vibration 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 vibration 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 into the piezoelectric ceramic sheet 2, the piezoelectric ceramic sheet 2 drives the central vibration 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.

[0020] The hole portion 121 includes a plurality of 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 sheet 2 is installed. Specifically, the centers of the plurality of 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 sheet 2. The evenly arranged through holes help to achieve even circulation of the fluid in the pump body 6, further improving the working efficiency and stability of the fluid pump.

[0021] like Figure 3 and 4 As shown, the core of the 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 arranged under the flexible support plate 1, and the first support washer 4 includes a first outer frame 41 and a plurality of first support portions 42 arranged at the inner edge of the first outer frame 41, and the plurality of first support portions 42 are arranged circumferentially on the first outer frame 41 at equal intervals, and the first support portions 42 are arranged corresponding to the through hole. The first outer frame 41 is used to fix the first support portion 42, and the first support portion 42 supports the through hole of the flexible hinge portion 12 from the bottom, which reduces the vibration amplitude of the flexible hinge at the through hole to a certain extent, thereby improving the fatigue strength, reducing the risk of cracking at the opening, and extending the service life of the vibrator.

[0022] like Fig. 9 and 10As shown, in order to facilitate assembly, 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 connection surface of the first support portion 42 and the first outer frame 41. When installing, first place the first support gasket 4 in the installation ring groove 621 of the bottom shell 62, and then place the flexible support plate 1 on the support gasket, so that the edge fixing portion 13 of the outer periphery of the flexible support plate 1 is just clamped on the step 43 for limiting. At this time, the edge fixing portion 13 is limited by the step 43 in the installation ring groove 621, thereby ensuring that the assembly is in place.

[0023] like Figure 3 and 4 As shown, in order to further prevent the flexible hinge at the through hole from cracking under high-frequency vibration, a second support washer 5 is also arranged above the flexible support plate 1. The second support washer 5 includes a second outer frame 51 and a plurality of second support portions 52 arranged 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 arranged corresponding to the through hole. The second outer frame 51 is used to fix the second support portion 52. The second support portion 52 and the first support portion 42 support the through hole of the flexible hinge portion 12 from above and below, respectively, which greatly reduces 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.

[0024] like Fig. 9 and 10 As 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 53 is formed on the connecting surface between 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 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 of the outer 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 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.

[0025] like Figure 5As 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 of 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.

[0026] 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 restraint resistance to vibration and the smaller the amplitude; the thinner the support part, the smaller the restraint resistance to vibration and the larger the amplitude; the smaller the distance between the support part and the through hole, the greater the restraint resistance to vibration and the smaller the amplitude; the larger the distance between the support part and the through hole, the smaller the restraint resistance to vibration and the larger the amplitude.

[0027] 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, avoidance holes 122 opposite to the through hole are provided on the first support portion 42 and the second support portion 52. The avoidance holes 122 are provided corresponding to the through hole and do not affect the circulation of the fluid between the upper cavity 64 and the lower cavity 65.

[0028] like Figure 6-8 As 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 plane 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 plane of the upper cover 61 is provided with a mounting boss 611 that matches the mounting ring groove 621, and the first outer frame 41, the edge fixing portion 13 and the second outer frame 51 are restricted 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 the interior of the pump body 6 is divided 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.

[0029] Through the cooperation of the mounting boss 611 of the upper cover 61 and the mounting 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 to achieve fluid suction and discharge.

[0030] The upper cover 61 is provided with a fluid outlet 612 communicating with the upper cavity 64, the bottom shell 62 is provided with a fluid inlet 622 communicating with the lower cavity 65, and both the fluid outlet 612 and the fluid inlet 622 are provided with a one-way valve 63. The one-way valve 63 provided at the fluid outlet 612 and the fluid inlet 622 enables one-way flow of gas to improve the working efficiency of the pump.

[0031] The above description is only illustrative rather than restrictive of the present invention. 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 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 sheet (2) and a frequency adjustment plate (3); 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 sheet (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).

2. A piezoelectric vibrator according to claim 1, characterized in that: The hole portion (121) comprises a plurality of through holes circumferentially arranged on the flexible hinge portion (12), and the centers of the plurality of through holes are all located at the center of the width of the flexible hinge portion (12).

3. A piezoelectric vibrator according to claim 2, characterized in that: A first supporting washer (4) is arranged 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) arranged at an inner edge of the first outer frame (41), the plurality of first supporting portions (42) being circumferentially arranged at equal intervals on the first outer frame (41), and the first supporting portions (42) being arranged corresponding to the through holes.

4. A piezoelectric vibrator according to claim 3, 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 an edge fixing portion (13) of the flexible support plate (1) is formed on a connecting surface between the first support portion (42) and the first outer frame (41).

5. A piezoelectric vibrator according to claim 3, characterized in that: A second supporting washer (5) is arranged 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) arranged at an inner edge of the second outer frame (51), the plurality of second supporting portions (52) being circumferentially arranged at equal intervals on the second outer frame (51), and the second supporting portions (52) being arranged corresponding to the through holes.

6. A piezoelectric vibrator according to claim 5, characterized in that: 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).

7. A piezoelectric vibrator according to claim 5, characterized in that: The first support portion (42) and the second support portion (52) are square, trapezoidal or semicircular, and are each provided with an avoidance hole (122) opposite to the through hole, 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).

8. A fluid pump, characterized in that: It comprises a pump body (6) and the piezoelectric vibrator according to any one of claims 1 to 7.

9. A fluid pump according to claim 8, 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 annular groove (621) capable of accommodating a first outer frame (41), an edge fixing portion (13) and a second outer frame (51); the lower plane of the upper cover (61) is provided with a mounting boss (611) matched with the mounting annular 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 via a hole (121) on the flexible hinge portion (12).

10. A fluid pump according to claim 9, 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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