Multi-vibrator coordinated piezoelectric fan heat dissipation device

Abstract

The utility model discloses a kind of piezoelectric fan heat dissipation devices of multiple vibrator cooperation. The device adopts the modularization closed cavity structure formed by bottom plate, middle frame and cover plate, and its core is that piezoelectric vibrator array consisting of at least two piezoelectric vibrators is integrated in cavity, and flow channel structure is integrally designed with one of rear of vibrator free end. By the systematic collaborative optimization to the key geometric parameters of piezoelectric vibrator array, and in combination with the flow channel with the functions of current collection, flow guide and current convergence, the independent pulsating air current generated by multiple vibrators is efficiently integrated into a uniform and stable concentrated jet. The scheme effectively breaks through the performance bottleneck of single vibrator, and in extremely limited space, simultaneously realizes the significant improvement of heat dissipation air volume, air quality and energy efficiency, especially suitable for high-end compact electronic equipment.

Description

Technical Field

[0001] This utility model relates to the technical field of fluid transport and heat dissipation devices, specifically a multi-oscillator coordinated piezoelectric fan heat dissipation device. Background Technology

[0002] As smart terminal devices continue to evolve towards higher performance and thinner designs, their internal space is becoming increasingly compact, making thermal design a key factor affecting device performance and stability. In products such as smartphones, smart glasses, AR / VR devices, and ultra-thin laptops, traditional axial fans are unsuitable due to their size, thickness, and electromagnetic interference issues, while passive cooling solutions are gradually approaching their thermal limits when facing transient high power consumption. Therefore, the industry urgently needs an active cooling technology that can be embedded in millimeter-level spaces and combines low power consumption with quiet operation.

[0003] Piezoelectric fans, as fluid-driven devices based on the inverse piezoelectric effect, propel airflow through the high-frequency, low-amplitude vibration of piezoelectric oscillators. Due to their advantages such as thinness, lack of electromagnetic interference, and low energy consumption, they have received widespread attention in recent years. Currently, a typical implementation employs a double piezoelectric crystal cantilever beam structure. This structure generates bending vibrations under AC signal drive, thereby achieving the fan function.

[0004] However, existing piezoelectric fan solutions still have several obvious limitations: First, the air volume output of a single-oscillator structure is limited, making it difficult to meet the continuously increasing heat dissipation requirements; second, when multiple oscillators are simply arranged in parallel, airflow interference is easily generated, making it impossible to effectively form a synergistic enhancement effect; more importantly, existing solutions lack effective organization and guidance of the airflow generated by the oscillators, resulting in turbulent and significant pulsation of the output airflow and low energy utilization efficiency; in addition, traditional piezoelectric fans usually lack modular design when integrating the whole machine, posing challenges to installation positioning accuracy and structural reliability, which is not conducive to modern automated production.

[0005] In summary, existing piezoelectric fan technology still has significant shortcomings in terms of airflow organization, space utilization, and integration when addressing the heat dissipation needs of next-generation electronic devices. There is an urgent need for a systematic solution that can achieve efficient airflow integration, a compact structure, and is easy to mass-produce. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a multi-oscillator coordinated piezoelectric fan heat dissipation device.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] A multi-vibrator coordinated piezoelectric fan cooling device includes a base plate, a middle frame, a piezoelectric vibrator array, and a cover plate. The base plate serves as the core structural component and aerodynamic foundation. The middle frame is fixed to the base plate and has at least two vibrator mounting positions. The piezoelectric vibrator array consists of at least two piezoelectric vibrators, with one end of each vibrator fixed to a mounting position and the other end free. The cover plate covers the middle frame and, together with the base plate, forms a sealed cavity encapsulating the piezoelectric vibrator array. The base plate, middle frame, and cover plate are fixed together by methods such as adhesive bonding, welding, thermosetting, or interference fit. The device also includes an electrical connection structure for transmitting drive signals to the piezoelectric vibrator array. The core of this invention lies in the fact that a dedicated flow channel structure is integrated behind the free end of the piezoelectric vibrator array within the sealed cavity. The flow channel structure consists of the shape of the sealed cavity and guide fins disposed within the sealed cavity. This flow channel structure is used to integrate and guide the airflow generated by the coordinated vibration of multiple piezoelectric vibrators, thereby solving the problems of limited airflow and turbulent airflow of a single vibrator, and enabling the heat dissipation device to output a cooling airflow with a large volume, uniform stability, and concentrated direction.

[0009] As a further improvement of this utility model, the flow channel structure includes a collection area, a guide area, and a convergence area connected in sequence; the width of the collection area is greater than or equal to the width of the piezoelectric vibrator array, used to collect the airflow from each piezoelectric vibrator; at least two guide fins are provided in the guide area, the guide fins divide the guide area into multiple independent sub-channels, used to sort out the turbulent airflow from multiple piezoelectric vibrators, making their flow direction tend to be consistent, so as to improve the output air volume and air pressure; the convergence area is used to smoothly output the sorted airflow in the form of a concentrated jet, preferably, the number of independent sub-channels is at least equal to the number of piezoelectric vibrators.

[0010] As a further improvement of this utility model, the width of the flow guiding area gradually narrows along the airflow direction to form a converging channel. Preferably, the sidewall of the flow guiding area is composed of the inner sidewall of the middle frame, which gradually thickens along the airflow direction. The multiple flow guiding fins are parallel to each other and reach the full height of the sealed cavity, dividing the flow guiding area into multiple parallel independent sub-channels. Preferably, the flow guiding fins are fixed to the base plate by welding.

[0011] As a further improvement of this utility model, the piezoelectric oscillator is a double piezoelectric wafer cantilever beam structure, including an intermediate passive layer and an upper piezoelectric material layer and a lower piezoelectric material layer attached to its upper and lower surfaces. The upper and lower piezoelectric material layers are made of piezoelectric materials with inverse piezoelectric effect.

[0012] In a key optimization design, the thickness of the intermediate passive layer is less than or equal to the thickness of the single-sided piezoelectric material layer. By appropriately reducing the thickness of the intermediate passive layer, the bending stiffness of the entire composite beam is effectively reduced, thereby achieving a larger vibration amplitude under the same driving voltage and directly improving the fan capacity and heat dissipation efficiency of the single vibrator. Preferably, one end of the intermediate passive layer is provided with a positioning protrusion, which cooperates with the vibrator mounting position of the middle frame to install and fix the piezoelectric vibrator to the middle frame, and is fixed by means of gluing, welding, interference fit, etc.

[0013] As a further improvement of this utility model, the key geometric parameters of the piezoelectric vibrator array have been synergistically optimized. Preferably, the ratio of the vibrator length L of the piezoelectric vibrator to the total length of the heat dissipation device is 42.6% to 51.6%. Preferably, the ratio of the spacing D between adjacent piezoelectric vibrators to the vibrator length L, D / L, is 0.09 to 0.15. Preferably, the ratio of the spacing D between adjacent piezoelectric vibrators to the vibrator width W, D / W, is 1 to 1.5.

[0014] As a further improvement of this utility model, the width W of the piezoelectric vibrator is configured to adapt to the overall thickness H_total of the heat dissipation device, so as to achieve the maximum effective working area within an extremely thin space.

[0015] As a further improvement of this utility model, the cover plate is provided with a plurality of ventilation openings for air intake. The shape and layout of the ventilation openings are configured to provide sufficient air intake flow while ensuring the structural rigidity of the cover plate, such as regular shapes like elongated strips or elliptical shapes.

[0016] The beneficial effects of this utility model are:

[0017] This invention, employing the aforementioned technical solution, utilizes a modular sealed cavity structure comprised of a base plate, middle frame, and cover plate. By collaboratively optimizing key parameters such as the spacing, length, and width of multiple piezoelectric vibrators within the sealed cavity, the resulting multiple airflows can be efficiently captured and integrated by the integrated flow channel structure at the tail end of the heat dissipation device. This design combines the optimization of vibrator parameters with the guiding effect of the flow channel, transforming the originally independent and chaotic reciprocating pulsating airflow from multiple vibrators into a concentrated jet with significantly increased airflow and uniform stability. This achieves a significant increase in heat dissipation airflow and a fundamental improvement in airflow quality within a limited space. Its compact modular design greatly enhances spatial adaptability, perfectly meeting the heat dissipation requirements of ultra-thin devices. Furthermore, because this invention can accept in-phase or out-of-phase drive signals from the controller, it can flexibly adjust its operating state according to different scenarios, achieving a balance between high performance and low noise. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is an exploded view of the present invention.

[0021] Figure 3 This is a three-dimensional view of the piezoelectric vibrator of this utility model.

[0022] Figure 4 for Figure 3 Enlarged view of point A.

[0023] Figure 5 This is a simulation diagram of the airflow trajectory of this utility model.

[0024] The numbers in the diagram represent: 1. Base plate, 2. Middle frame, 3. Piezoelectric vibrator array, 4. Cover plate, 5. Vibrator mounting position, 6. Piezoelectric vibrator, 7. Middle passive layer, 8. Upper piezoelectric material layer, 9. Lower piezoelectric material layer, 10. Current collection area, 11. Current guiding area, 12. Current converging area, 13. Current guiding fin. Detailed Implementation

[0025] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] See Embodiment 1 of this utility model. Figures 1 to 5 :

[0029] This embodiment is used to provide detailed support for a multi-oscillator coordinated piezoelectric fan cooling device.

[0030] The device includes a base plate 1, a middle frame 2, a piezoelectric vibrator array 3, and a cover plate 4. Specifically, the base plate 1 serves as the core structural component and pneumatic foundation of the entire device. The middle frame 2 is fixed to the base plate 1 by adhesive bonding. The middle frame 2 has multiple vibrator mounting positions 5 and integrates an electrical connection structure (e.g., an FPC flexible circuit board). This electrical connection structure is configured to receive high-frequency AC drive signals from an external controller and can transmit signals of different phases (in-phase or out-of-phase signals), thereby enabling the piezoelectric vibrator array 3 to operate in multiple cooperative modes (e.g., in-phase mode with high wind pressure or out-of-phase mode with low noise). The piezoelectric vibrator array 3 consists of multiple piezoelectric vibrators 6. One end of each piezoelectric vibrator 6 is fixed to a vibrator mounting position 5, and the other end is a free end. In this embodiment, the piezoelectric vibrators 6 are installed vertically, and the number of piezoelectric vibrators 6 and vibrator mounting positions 5 is the same—eight in total—with adjacent vibrators arranged parallel to each other. The cover plate 4 covers the middle frame 2 and together with the base plate 1 forms a sealed cavity, encapsulating the piezoelectric vibrator array 3 within it. To ensure airtightness, the joint surfaces between the base plate 1, the middle frame 2, and the cover plate 4 are fixed by adhesive bonding, and sealant is applied to the joint surfaces to prevent airflow leakage and ensure that all driven air can be effectively output through the designed flow channels.

[0031] Within the sealed cavity, a flow channel structure is provided behind the free ends of each piezoelectric vibrator 6 in the piezoelectric vibrator array 3. The flow channel structure comprises a cavity space enclosed by the base plate 1, the middle frame 2, and the cover plate 4, and guide fins 13 disposed within this space. This flow channel structure is used to integrate and guide the airflow generated by the piezoelectric vibrator array 3. The guide fins 13 are fixed to the base plate 1 by welding.

[0032] The flow channel structure includes a sequentially connected flow collection zone 10, a flow guiding zone 11, and a convergence zone 12. The width of the flow collection zone 10 is greater than the width of the piezoelectric vibrator array 3, used to gather the airflow from each piezoelectric vibrator 6. The flow guiding zone 11 is provided with multiple flow guiding fins 13, which divide the flow guiding zone 11 into multiple independent sub-channels, used to manage the turbulent airflow from the multiple piezoelectric vibrators 6, making their flow direction more consistent, thereby improving the output airflow and air pressure. The convergence zone 12 is used to output the managed airflow in the form of a concentrated jet. (See reference...) Figure 5 This flow channel structure effectively suppresses the lateral flow and secondary eddies that may be generated during the convergence process of the airflow, ensuring that the airflow remains in a laminar state during acceleration, and making the velocity distribution on the airflow cross section more uniform.

[0033] The width of the flow guiding region 11 gradually decreases along the airflow direction (i.e., towards the confluence region 12). The plurality of flow guiding fins 13 are parallel to each other, thereby dividing the flow guiding region 11 into a plurality of parallel independent sub-channels.

[0034] The piezoelectric vibrator 6 is a cantilever beam structure with two piezoelectric wafers. (See also...) Figure 4 It includes an intermediate passive layer 7 and an upper piezoelectric material layer 8 and a lower piezoelectric material layer 9 attached to its upper and lower surfaces. The upper piezoelectric material layer 8 and the lower piezoelectric material layer 9 are made of piezoelectric materials with inverse piezoelectric effect.

[0035] In a preferred embodiment of this invention, the piezoelectric material is a piezoelectric ceramic, such as lead zirconate titanate (PZT). In other embodiments, the piezoelectric material may also be a piezoelectric single crystal (such as PMN-PT) or a piezoelectric polymer (such as PVDF). The intermediate passive layer is composed of a metal (such as phosphor bronze or stainless steel) or a flexible composite material.

[0036] To facilitate installation, positioning, and fixation, the intermediate passive layer 7 has upward and downward extending positioning protrusions at the mounting and fixing end of the piezoelectric vibrator. These positioning protrusions cooperate with corresponding slots on the vibrator mounting position 5 of the middle frame 2, achieving precise pre-positioning and mechanical interlocking of the piezoelectric vibrator 6. Final reinforcement can then be achieved through adhesive bonding or welding to ensure reliable fixation. In this embodiment, the thickness of the intermediate passive layer 7 is 0.06 mm, and the thicknesses of the upper piezoelectric material layer 8 and the lower piezoelectric material layer 9 are both 0.12 mm, meaning the thickness of the intermediate passive layer 7 is less than the thickness of the piezoelectric material layer on each side. This non-uniform thickness design, by thinning the intermediate passive layer 7 while ensuring structural robustness, effectively reduces the bending stiffness of the composite beam, thereby achieving a larger vibration amplitude under the same driving voltage.

[0037] In another feasible solution, the piezoelectric vibrator 6 can also be designed with uniform thickness. For example, its total thickness T is 0.3 mm, with the upper piezoelectric material layer 8, the middle passive layer 7, and the lower piezoelectric material layer 9 all having a thickness of 0.1 mm. This solution has certain advantages in terms of process simplicity.

[0038] The length of the piezoelectric vibrator 6 in this embodiment is optimized. The total length of the device is 45 mm, and the length L of the piezoelectric vibrator 6 is 19.5 mm. Calculations show that the ratio of L to the total length is 43.3%, which falls within the range of 42.6% to 51.6%.

[0039] The spacing of the piezoelectric vibrator array 3 in this embodiment is optimized. The width W of the piezoelectric vibrator 6 is 1.8 mm, and the spacing D between adjacent piezoelectric vibrators 6 is 2.2 mm. The calculated ratio D / L of the spacing D to the vibrator length L is 0.113, which falls within the range of 0.09 to 0.15. Simultaneously, the ratio D / W of the spacing D to the vibrator width W is 1.22, which falls within the range of 1 to 1.5.

[0040] The cover plate 4 has multiple ventilation openings. In a preferred embodiment, the ventilation openings are composed of multiple regular geometric shapes (such as rectangles, circles, ellipses, or squares) arranged in an intermittent array.

[0041] Working principle: An external controller generates a high-frequency AC drive signal, which is applied to the piezoelectric resonator array 3 through the circuit on the middle frame 2. Each piezoelectric resonator 6 undergoes bending vibration using the inverse piezoelectric effect of the piezoelectric material, driving air to enter through the ventilation opening. After flowing through the resonator area, the air is collected in the collector area 10, then rectified by the tapered channel and guide fins 13 in the guide area 11, and finally output as a stable and concentrated jet from the collector area 12, acting on the heat source to achieve efficient heat dissipation. As a complete heat dissipation module, this device is designed to be integrated with the control and temperature detection system on the mainboard of the equipment, thereby achieving flexible and intelligent control of heat dissipation performance at the system level.

[0042] Example 2

[0043] As an extended embodiment, at least two piezoelectric elements 6 in the piezoelectric array 3 have different lengths and / or different widths. This design allows the array to cover a wider frequency spectrum, thereby exciting a richer variety of air modes during actuation, which helps to further optimize airflow organization and reduce operating noise at a single frequency.

[0044] As another extended embodiment, more guide fins 13 can be added to the flow channel structure's guide zone 11, or guide fins with a specific inclination angle can be provided. This design can redistribute and shape the airflow for scenarios that require guiding airflow to a specific area or performing more precise flow field control.

[0045] As another extended embodiment, the base plate 1 can be a vapor chamber or a vapor chamber made of a high thermal conductivity metal (such as copper or aluminum alloy). In this embodiment, the flow guide fins 13 are made of metal and integrally connected to the base plate 1 by welding. This structure not only provides flow channel functionality but also greatly enhances the lateral temperature uniformity and passive heat dissipation effect of the entire device, achieving synergy between active and passive heat dissipation.

[0046] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A multi-oscillator coordinated piezoelectric fan heat dissipation device, characterized in that, include: Base plate (1); The middle frame (2) is fixed on the base plate (1), and the middle frame (2) is provided with at least two vibrator mounting positions (5). The piezoelectric vibrator array (3) consists of at least two piezoelectric vibrators (6), one end of each piezoelectric vibrator (6) is fixed to the vibrator mounting position (5), and the other end is a free end; The cover plate (4) covers the middle frame (2) and together with the bottom plate (1) forms a sealed cavity to encapsulate the piezoelectric oscillator array (3) inside; The sealed cavity is provided with a flow channel structure behind the free end of each piezoelectric vibrator (6) in the piezoelectric vibrator array (3). The flow channel structure is used to integrate and guide the airflow generated by the piezoelectric vibrator array (3).

2. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 1, characterized in that: The flow channel structure includes a flow collection area (10), a flow guiding area (11), and a flow convergence area (12) connected in sequence. The width of the collection area (10) is greater than or equal to the width of the piezoelectric vibrator array (3) for collecting airflow from each piezoelectric vibrator (6); At least two guide fins (13) are provided in the flow guiding area (11), and the guide fins (13) divide the flow guiding area (11) into multiple independent sub-channels for sorting and rectifying airflow; The confluence zone (12) is used to output the airflow in the form of a concentrated jet.

3. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 2, characterized in that: The width of the guide zone (11) gradually decreases along the airflow direction; The multiple guide fins (13) are parallel to each other, and the guide fins (13) divide the guide area (11) into multiple parallel independent sub-channels.

4. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 1, characterized in that: The piezoelectric oscillator (6) is a double piezoelectric wafer cantilever beam structure, including an intermediate passive layer (7) and an upper piezoelectric material layer (8) and a lower piezoelectric material layer (9) attached to its upper and lower surfaces. The thickness of the intermediate passive layer (7) is less than or equal to the thickness of the single-sided piezoelectric material layer.

5. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 1, characterized in that: The ratio of the length L of the piezoelectric vibrator (6) to the total length of the heat dissipation device is 42.6% to 51.6%.

6. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 1, characterized in that: In the piezoelectric vibrator array (3), the ratio of the spacing D between adjacent piezoelectric vibrators (6) to the length L of the vibrator, D / L, is 0.09 to 0.

15.

7. A multi-oscillator coordinated piezoelectric fan cooling device according to claim 1 or 6, characterized in that: In the piezoelectric vibrator array (3), the ratio of the spacing D between adjacent piezoelectric vibrators (6) to the width W of the vibrator, D / W, is 1 to 1.

5.

8. The multi-oscillator coordinated piezoelectric fan heat dissipation device according to claim 1, characterized in that: The cover plate (4) has multiple ventilation openings.

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