Oscillator for micro piezoelectric pump

Abstract

The utility model relates to a vibrator for a micro piezoelectric pump, which belongs to the technical field of piezoelectric pump drivers and solves the problems of insufficient structural strength, higher failure rate and complicated manufacturing process of the piezoelectric pump drivers in the prior art. The fixing plate comprises a circular reinforcing part located in the center and an elastic fixing frame surrounding the reinforcing part, and the fixing plate is of an integrated structure. Wherein the reinforcing part comprises a mounting surface and a resonant surface which are opposite to each other, and the elastic fixing frame is provided with a mounting part for embedded mounting; the piezoelectric element is fixedly mounted on the mounting surface of the reinforcing part; when the vibrator works, the piezoelectric element is electrified to generate radial expansion and contraction, so that the vibrator is switched between the following two states: in a first state, when the piezoelectric element contracts, the reinforcing part is driven to protrude upwards, and the elastic fixing frame is bent downwards; in the second state, when the piezoelectric element stretches, the reinforcing part is driven to sink downwards, and the elastic fixing frame is bent upwards.

Description

Technical Field

[0001] The utility model relates to the technical field of piezoelectric pump drivers, and particularly relates to an oscillator for a micro piezoelectric pump. Background Art

[0002] As a micro device with strong coupling of multiple disciplines such as cross materials, structures, fluids, electronics, and processes, the micro piezoelectric pump has the advantages of small size, low power consumption, high specific back pressure, large specific flow rate, high-speed response, high flow accuracy, etc. It has a wide application space in the fields of medical devices and semiconductor thermal management, and is particularly suitable for the applications of wearable and portable medical devices and ultra-thin micro-space heat dissipation management applications.

[0003] The core component in the micro piezoelectric pump is the oscillator. When the piezoelectric pump works, the reciprocating vibration of the piezoelectric oscillator causes the periodic change of the pump cavity volume, and the change of the volume causes the change of the pressure in the pump cavity, thereby controlling the opening and closing of the valve.

[0004] In the existing micro piezoelectric pump, the oscillator and the side wall are of an integrated structure, which is not suitable for the multi-layer stacking assembly process. In addition, due to the large difference in thickness between the side wall of the oscillator and the internal structure, multiple etching processes are required to form the shape. The processing technology is complex, and it is difficult to control the etching depth and the dimensional accuracy of the vibrating part structure. During the operation of the micro piezoelectric pump, the oscillator is in a vibrating state for a long time, and the structural strength of the oscillator is difficult to meet the requirements, prone to fatigue damage, with a high failure rate, thus affecting the service life of the micro piezoelectric pump and the products using it.

[0005] Therefore, there is a need in this technical field for an oscillator for a micro piezoelectric pump that provides an improved high-frequency vibration effect, enhanced structural strength, good adaptability, a wide range of applications, and is convenient for simplifying the process flow and mass production. Summary of the Utility Model

[0006] In order to solve the above problems, according to an embodiment of the present utility model, an oscillator for a micro piezoelectric pump is provided, including:

[0007] A fixing plate, which includes a circular reinforcing part at the center and an elastic fixing frame surrounding the reinforcing part, and the fixing plate is of an integrated structure;

[0008] Wherein, the reinforcing part includes opposite mounting surfaces and resonant surfaces, and the elastic fixing frame has a mounting part for fitting installation; and

[0009] A piezoelectric element, which is fixedly installed on the mounting surface of the reinforcing part;

[0010] When the oscillator works, the piezoelectric element is energized to generate radial expansion and contraction, causing the oscillator to switch between the following two states:

[0011] In the first state, when the piezoelectric element contracts, it drives the reinforcing part to bulge upward and the elastic fixing frame to bend downward;

[0012] In the second state, when the piezoelectric element expands, it drives the reinforcing part to sink downward and the elastic fixing frame to bend upward.

[0013] Optionally, the resonant surface of the reinforcing part has a circular boss, and the diameter of the circular boss is smaller than the diameter of the reinforcing part.

[0014] Optionally, the elastic fixing frame is an octagonal structure, including:

[0015] Four connecting parts, which are evenly distributed at equal intervals around the reinforcing part and extend radially outward from the outer edge of the reinforcing part;

[0016] Four side beams, which extend in a direction perpendicular to the radial direction of the reinforcing part at the ends of the connecting parts far from the reinforcing part; and

[0017] Four diagonal beams, which obliquely cut and connect with the side beams, and the extension parts of the diagonal beams extending outward from the connection positions with the side beams form the mounting parts;

[0018] Wherein the width of the diagonal beam is greater than the width of the side beam.

[0019] Optionally, each diagonal beam has two extension parts, each extension part is in the shape of an oblique angle, and a thickening part is formed at the end of the extension part, and the thickness of the thickening part is greater than the thickness of the rest of the diagonal beam.

[0020] Optionally, the connecting part is in an arc shape, trapezoidal shape or triangular shape extending between the middle positions of the reinforcing part and the side beam.

[0021] Optionally, four spaced-apart hollow spaces are formed between the reinforcing part, the connecting part, the side beam and the diagonal beam of the fixing plate.

[0022] Optionally, the piezoelectric element and the fixing plate are fixedly assembled by high-temperature bonding.

[0023] Optionally, the fixing plate is made of stainless steel or carbon fiber composite material.

[0024] Optionally, the thickness of the reinforcing part is in the range of 0.20 mm to 0.35 mm, and the thickness of the piezoelectric element is in the range of 0.10 mm to 0.20 mm.

[0025] Optionally, the connecting part is in a hyperbolic shape, circular shape, elliptical shape or convex shape extending between the middle positions of the reinforcing part and the side beam.

[0026] An oscillator for a micro piezoelectric pump provided by the utility model causes periodic changes in the volume of the pump chamber through reciprocating vibration, and the change in volume causes a change in the pressure in the pump chamber, thereby controlling the opening and closing of the valve.

[0027] Compared with the prior art, the oscillator for a micro piezoelectric pump provided by the embodiment of the utility model has at least the following beneficial effects:

[0028] 1. The reinforcing part of the fixing plate of the oscillator and the elastic fixing frame are of an integral structure and can be integrally formed. Not only is the process simpler, but the processing efficiency is higher.

[0029] 2. The assembly structure of the oscillator composed of the fixing plate and the piezoelectric element is more suitable for the bonding process with other components of the micro piezoelectric pump and can be bonded in multiple layers at one time, which is beneficial to further reducing the overall volume of the oscillator and improving the device integration under the condition of meeting the oscillator performance.

[0030] 3. After installation, through the structure of the elastic fixing frame of the fixing plate, four triangular vacant areas outside the hypotenuse are obtained as invalid areas. The invalid area is very small, thus ensuring a large effective vibration area and meeting the high performance of the oscillator.

[0031] 4. The structure of the elastic fixing frame of the fixing plate makes full use of the characteristics of high elastic modulus and low density of composite materials such as carbon fiber, achieving a high resonance frequency on an extremely thin material, making the pump body thinner and lighter in weight.

[0032] 5. The fixing plate of the oscillator includes an extension part for installation, which can be assembled with another independent outer frame structure, so that it can be applied to piezoelectric pumps with different shapes, and has better adaptability. And because the oscillator and the outer frame are manufactured separately, their respective processing processes are simpler, and different materials can be used respectively, which is more beneficial to their different structural strength requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. By referring to the drawings, the features and advantages of the present utility model can be more clearly understood. The drawings are schematic and should not be construed as any limitation to the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a top view of an oscillator for a micro piezoelectric pump provided by an embodiment of the present utility model.

[0035] Figure 2 It is a bottom view of the oscillator for a micro piezoelectric pump provided by the embodiment of the present utility model.

[0036] Figure 3 An isometric view of the vibrator for a micro piezoelectric pump provided for the embodiment of the present utility model.

[0037] Reference numerals:

[0038] 1 - Vibrator;

[0039] 10 - Piezoelectric element;

[0040] 20 - Fixed plate;

[0041] 30 - Reinforcing portion;

[0042] 32 - Mounting surface;

[0043] 34 - Resonant surface;

[0044] 36 - Circular boss;

[0045] 40 - Elastic fixing bracket;

[0046] 42 - Connecting portion;

[0047] 44 - Side beam;

[0048] 46 - Diagonal beam;

[0049] 48 - Extension portion;

[0050] 49 - Thickening portion;

[0051] 50 - Hollow space. Detailed implementation manners

[0052] In order to more clearly understand the above objects, features and advantages of the present utility model, the present utility model will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present utility model and the features in the embodiments can be combined with each other.

[0053] In the following description, many specific details are set forth to fully understand the present utility model, but the present utility model can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present utility model is not limited by the specific embodiments disclosed below.

[0054] The following will refer to the drawings to detail a vibrator for a micro piezoelectric pump according to an embodiment of the present utility model.

[0055] As Figures 1 to 3As shown, an oscillator 1 for a micro piezoelectric pump provided according to an embodiment of the present utility model includes: a piezoelectric element 10, and a fixing plate 20 for fixing the piezoelectric element 10, wherein the fixing plate 20 includes a reinforcing portion 30 at the center and an elastic fixing frame 40 surrounding the reinforcing portion 30. The fixing plate 20 including the reinforcing portion 30 and the elastic fixing frame 40 is a structure integrally formed from a single piece of material. The piezoelectric element 10 is circular and is fixed to the surface of the reinforcing portion 30. The piezoelectric element 10 is made of ceramic and the thickness can be in the range of 0.10 mm to 0.20 mm. The fixing plate 20 can be made of 430 stainless steel. In this embodiment, the piezoelectric element 10 of the oscillator 1 and the fixing plate 20 can be installed and fixed by means of high-temperature bonding. When the oscillator 1 is applied to a micro piezoelectric pump, the oscillator 1 can be assembled in a suitable outer frame, the elastic fixing frame 40 of the oscillator 1 is assembled with the outer frame, and the outer frame assembled with the oscillator 1 is stacked and combined with other components to form a micro piezoelectric pump. The elastic fixing frame 40 of the oscillator 1 and the outer frame can be assembled using a bonding process.

[0056] As Figure 1 and Figure 2 shown, the reinforcing portion 30 located at the center of the fixing plate 20 is circular and its size is larger than that of the piezoelectric element 10. The thickness of the reinforcing portion 30 can be in the range of 0.20 mm to 0.35 mm. The reinforcing portion 30 may include opposite mounting surfaces 32 and resonant surfaces 34. The mounting surface 32 is a smooth surface for fixing the piezoelectric element 10. In this embodiment, the piezoelectric element 10 can be fixed to the mounting surface 32 of the reinforcing portion 30 by means of high-temperature bonding under high-temperature conditions. The resonant surface 34 can be stepped and has a circular boss 36. Among them, the diameter of the circular boss 36 is smaller than the diameter of the reinforcing portion 30, and the circular boss 36 is coaxial with the reinforcing portion 30. The diameter of the circular boss 36 can be smaller than the diameter of the piezoelectric element 10. The circular boss 36 at the center of the reinforcing portion 30 can cooperate with resonance when the oscillator 1 vibrates, improve the resonance frequency, and achieve a better vibration effect. The reinforcing portion 30 provides a reinforcing effect on the piezoelectric element 10, so that the piezoelectric element 10 can obtain good structural support during vibration work and is not easily damaged. And during the manufacturing process, when high-temperature bonding is performed, the reinforcing portion 30 will be compressed to provide prestress to the piezoelectric element 10, further enhancing its structural strength.

[0057] Reference Figures 1 to 3, the reinforcing portion 30 and the elastic fixing frame 40 of the fixing plate 20 in this embodiment are located in the same plane. The elastic fixing frame 40 forms a generally octagonal structure, including connecting portions 42 that are evenly distributed at equal intervals around the reinforcing portion 30 and extend outward from the outer edge of the reinforcing portion 30, four side beams 44 extending from the ends of the connecting portions 42 away from the reinforcing portion 30, and four diagonal beams 46 that obliquely cut and connect to the four side beams 44. In other words, the four side beams 44 and the four diagonal beams 46 are connected in an alternating manner to form the structure of the octagonal elastic fixing frame 40.

[0058] The connecting portion 42 of the elastic fixing frame 40 in this embodiment can extend from the outer edge of the reinforcing portion 30 to the side beam 44 in a strip shape, or can be in any suitable shape such as an arc, hyperbola, circle, trapezoid, triangle, ellipse, convex drum shape, etc. extending between the middle positions of the reinforcing portion 30 and the side beam 44.

[0059] In this embodiment, each connecting portion 42 is connected to the side beam 44 at its middle position. At the connection of each side beam 44 with the corresponding connecting portion 42, it extends in a direction perpendicular to the radial direction connecting the connection point to the center of the reinforcing portion 30. The four side beams 44 are perpendicular to each other in pairs, and the four side beams 44 have equal lengths and do not contact each other. In other words, the combination of the four side beams 44 is generally in the form of a square frame around the reinforcing portion 30 with the four corners cut off.

[0060] Each diagonal beam 46 of the elastic fixing frame 40 in this embodiment is respectively connected to two adjacent side beams 44. The diagonal beam 46 can have an extension portion 48 extending outward from the connection with the side beam 44. The extension portion 48 forms an oblique angle shape, so that when the fixing plate 20 is assembled with the outer frame, it can be snap-fitted with the corresponding-shaped installation recess in the outer frame and can be kept stable and not easily loosened. At the end portion of the extension portion 48, it can also have a raised thickening portion 49 to strengthen the structural strength of the end. The thickness of the thickening portion 49 is greater than the thickness of the remaining portion of the diagonal beam 46. The thickening portion 49 at the end can enable the fixing plate 20 to have better installation strength in the assembly with the outer frame, and improve the stability and reliability during the installation and use of the component. The diagonal beam 46 is a long strip structure, and its width can be wider than the width of the long strip-shaped side beam 44 to provide reliable support for the side beam 44. The diagonal beam 46 and the side beam 44 can make the oscillator have good overall flatness and is not easy to generate local deformation, which may lead to a decrease in the pump yield.

[0061] As Figure 3As shown, four hollow spaces 50 are formed by enclosing between the reinforcing portion 30 of the fixing plate 20 and the elastic fixing frame 40, thereby providing a passage for the fluid to flow up and down the oscillator 1. After the fixing plate 20 of the oscillator 1 and the outer frame are installed, a triangular hollow space is formed between the outer side of the inclined beam 46 and the outer frame, and this triangular hollow space is an invalid area, which is beneficial to meeting the high performance of the oscillator. In addition, since the inclined beam 46 of the elastic fixing frame 40 has an extension portion 48 extending obliquely outward from the connection with the side beam 44, the inclined beam 46 extends beyond the outer side of the side beam 44 both longitudinally and transversely. Therefore, after being installed with the outer frame, the extension portion 48 of the inclined beam 46 is partially clamped into the installation portion of the outer frame, and the side beam 44 is located inside the outer frame and can have a narrow gap with the outer frame, which is beneficial to the flexibility of the side beam 44 to vibrate with the piezoelectric element 10 and to increase the vibration frequency.

[0062] The working process of the oscillator 1 for the micro piezoelectric pump provided by the above embodiment of the present utility model is as follows: when the piezoelectric element 10 is energized to generate a radial expansion and contraction movement, the reinforcing portion 30 of the fixing plate 20 and the elastic fixing frame 40 are forced to vibrate in a cosine waveform. Among them, when the piezoelectric element 10 contracts, it drives the reinforcing portion 30 to bulge upward and the elastic fixing frame 40 to bend downward; when the piezoelectric element 10 expands, it drives the reinforcing portion 30 to sink downward and the elastic fixing frame 40 to bend upward. Thus, with the change of the bending deformation direction of the reinforcing portion 30 and the elastic fixing frame 40, the reinforcing portion 30 supplements the strength of the piezoelectric element 10 during the vibration process, thereby improving the vibration effect and the resonance frequency.

[0063] The fixing plate 20 of this embodiment enhances the structural support for the piezoelectric element 10 through the structure of the reinforcing portion 30, increases the resonance frequency, realizes a better vibration effect, and provides prestress for the piezoelectric element 10 through the reinforcing portion 30, thereby improving the piezoelectric coefficient. The fixing plate 20 of this embodiment provides good elasticity through the structure of the side beam 44 of the elastic fixing frame 40 and can have a good vibration effect during the vibration of the oscillator 1; through the structure of the inclined beam 46 of the elastic fixing frame 40, it can stably and reliably support the vibration of the oscillator and realize the extended service life of the oscillator 1. In addition, through the structure of the independent fixing plate 20 that can be combined with the outer frame, its manufacturing process is more simplified, the manufacturing process is shortened, the device integration degree is improved, and it has good adaptability. It can be installed and combined with the outer frame with any outer peripheral shape according to needs, meeting the requirements of a wider range of application products.

[0064] According to another embodiment of the present utility model, there is provided an oscillator for a micro piezoelectric pump, including a piezoelectric element and a fixing plate. The structure of this oscillator is the same as that of the oscillator in the above first embodiment, and will not be elaborated here; the difference is that the fixing plate of the oscillator in this other embodiment is cut from a single piece of carbon fiber composite material. Due to the straight long strip structures of the side beams and the diagonal beams of the fixing plate, the high elastic modulus and low density characteristics of the carbon fiber composite material in the fiber length direction can be fully utilized to achieve a relatively high resonance frequency on an extremely thin material, further thinning the volume of the assembled piezoelectric pump.

[0065] According to another embodiment of the present utility model, there is provided an oscillator for a micro piezoelectric pump, including a piezoelectric element and a fixing plate. Among them, the difference in the structure of the oscillator from that of the oscillator in the above first embodiment is that the elastic fixing frame of the fixing plate can also be a generally rectangular structure, and among the four side beams, the length of a pair of opposite side beams serving as the long sides is greater than the length of a pair of opposite side beams serving as the short sides. The reinforcing part in the elastic fixing frame can be oval, and its size matches that of the rectangular elastic fixing frame. Optionally, the reinforcing part in the elastic fixing frame can still be circular, so that the distance between the side beam serving as the long side and the circular reinforcing part is shorter, while the distance between the side beam serving as the short side and the reinforcing part is longer. Therefore, the length of the connecting part between the side beam serving as the long side and the reinforcing part is smaller than the length of the connecting part between the side beam serving as the short side and the reinforcing part.

[0066] All of the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present application, and will not be elaborated one by one here.

[0067] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present utility model.

[0068] The above is only a preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model.

Claims

1. An oscillator for a micro piezoelectric pump, characterized in that, Comprising: A fixing plate, which includes a circular reinforcing portion at the center and an elastic fixing frame surrounding the reinforcing portion, and the fixing plate is of an integral structure; Wherein, the reinforcing portion includes opposite mounting surfaces and a resonant surface, and the elastic fixing frame has a mounting portion for fitting installation; And A piezoelectric element, which is fixedly mounted to the mounting surface of the reinforcing portion; Wherein when the oscillator operates, the piezoelectric element is energized to generate radial expansion and contraction, causing the oscillator to switch between the following two states: A first state, when the piezoelectric element contracts, driving the reinforcing portion to bulge upward and the elastic fixing frame to bend downward; A second state, when the piezoelectric element expands, driving the reinforcing portion to sink downward and the elastic fixing frame to bend upward.

2. The oscillator for a micro piezoelectric pump according to claim 1, wherein: The resonant surface of the reinforcing portion has a circular boss, and the diameter of the circular boss is smaller than the diameter of the reinforcing portion.

3. The oscillator for a micro piezoelectric pump according to claim 1, characterized in that, The elastic fixing frame is of an octagonal structure, including: Four connecting portions, which are evenly distributed at equal intervals around the reinforcing portion and extend radially outward from the outer edge of the reinforcing portion; Four side beams, which extend in a direction perpendicular to the radial direction of the reinforcing portion at the ends of the connecting portions away from the reinforcing portion; and Four diagonal beams, which obliquely cut and connect with the side beams, and the extending portions of the diagonal beams extending outward from the connection points with the side beams form the mounting portions; Wherein the width of the diagonal beams is greater than the width of the side beams.

4. The oscillator for a micro piezoelectric pump according to claim 3, characterized in that, Each diagonal beam has two extending portions, each extending portion is in the shape of an oblique angle, and a thickened portion is formed at the end of the extending portion, and the thickness of the thickened portion is greater than the thickness of the rest of the diagonal beam.

5. The oscillator for a micro piezoelectric pump according to claim 3, characterized in that, The connecting portion is in an arc shape, trapezoidal shape or triangular shape extending between the middle positions of the reinforcing portion and the side beam.

6. The vibrator for a micro piezoelectric pump according to claim 3, characterized in that, Four spaced-apart hollow spaces are formed between the reinforcing portion, the connecting portion, the side beam and the diagonal beam of the fixing plate.

7. The vibrator for a micro piezoelectric pump according to claim 1, characterized in that, The piezoelectric element and the fixing plate are fixedly assembled by high-temperature bonding.

8. The vibrator for a micro piezoelectric pump according to claim 1, characterized in that, The fixing plate is made of stainless steel or carbon fiber composite material.

9. The vibrator for a micro piezoelectric pump according to claim 1, characterized in that, The thickness of the reinforcing portion is in the range of 0.20 mm to 0.35 mm, and the thickness of the piezoelectric element is in the range of 0.10 mm to 0.20 mm.

10. The oscillator for a micro piezoelectric pump according to claim 3, characterized in that, The connecting portion is in a hyperbolic shape, circular shape, elliptical shape or convex shape extending between the middle positions of the reinforcing portion and the side beam.

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