A piezoelectric fan

Abstract

This invention relates to the field of heat dissipation technology, and more particularly to a piezoelectric fan, comprising: a blowing assembly, the blowing assembly including fan blades and a piezoelectric element disposed on the fan blades, the piezoelectric element being attached to the fan blades for driving the fan blades to reciprocate; and a one-way valve module, disposed in contact with the blowing assembly, including a diaphragm valve that opens in one direction away from the blowing assembly; wherein, the side of the fan blade facing the diaphragm valve has a groove. This invention, by providing a groove on the side of the fan blade facing the diaphragm valve, increases the amplitude of the fan blades, thereby increasing the airflow; furthermore, the groove also improves both the airflow and air pressure. Furthermore, the one-way opening diaphragm valve facing away from the blowing assembly effectively suppresses backflow. Compared with existing technologies, this invention not only effectively controls the airflow direction but also increases the output airflow, thereby improving the overall airflow output and thus enhancing the heat dissipation efficiency of the piezoelectric fan.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology, and more particularly to a piezoelectric fan. Background Technology

[0002] With the increasing miniaturization of electronic devices, the problem of internal heat accumulation has become more and more prominent. Piezoelectric fans, with their obvious advantages of small size and high integration, have gradually become a research hotspot for micro heat sinks. A piezoelectric fan is a fan that works based on the piezoelectric effect. When the piezoelectric element is excited by an electrical signal, it will undergo periodic deformation, which can cause airflow and generate wind. However, existing piezoelectric fans still face many challenges.

[0003] In related technologies, the core components of a piezoelectric fan typically include a piezoelectric element and a vibrating diaphragm that supports the piezoelectric element. The diaphragm is usually designed as a thin sheet or plate structure. The piezoelectric element drives the vibrating diaphragm to reciprocate, thereby achieving airflow.

[0004] However, in order to adapt to the miniaturization of electronic devices, the piezoelectric fan mentioned above needs to sacrifice most of the air volume while ensuring that the piezoelectric fan is small in size. In addition, the hot air recirculation phenomenon is also very obvious during the reciprocating vibration of the diaphragm, which leads to the low heat dissipation efficiency of the fan. Summary of the Invention

[0005] In view of at least one of the above-mentioned technical problems, the present invention provides a piezoelectric fan that employs structural improvements to enhance heat dissipation efficiency.

[0006] According to a first aspect of the present invention, a piezoelectric fan is provided, comprising:

[0007] A blower assembly, comprising a fan blade and a piezoelectric element disposed on the fan blade, the piezoelectric element being attached to the fan blade for driving the fan blade to reciprocate.

[0008] A one-way valve module, which is fitted to the blower assembly, includes a diaphragm valve that opens in one direction away from the blower assembly;

[0009] The fan blade has a groove on the side facing the diaphragm valve.

[0010] In some embodiments of the present invention, the fan blade includes a fixed part and a swinging part, the swinging part is connected to the fixed part and suspended, and the piezoelectric element is attached to the swinging part to drive the swinging part to reciprocate in the thickness direction.

[0011] In some embodiments of the present invention, the groove is disposed on the rocking part, including a flow-damping groove near the suspended end of the rocking part.

[0012] In some embodiments of the present invention, the groove further includes an amplification groove disposed near the fixing portion.

[0013] In some embodiments of the present invention, the one-way valve module further includes an air inlet plate sandwiched between the blower assembly and the diaphragm valve, the air inlet plate having an air inlet groove facing the fan blades.

[0014] In some embodiments of the present invention, the air inlet groove is provided corresponding to the swing part, and the depth of the air inlet groove is adapted to the vibration amplitude of the swing part.

[0015] In some embodiments of the present invention, the air inlet groove also has an air inlet hole, which is disposed opposite to the flow suppression groove.

[0016] In some embodiments of the present invention, the piezoelectric element is a bicrystalline piezoelectric ceramic, which is attached to both sides of the fan blade in the thickness direction. The bicrystalline piezoelectric ceramics have opposite polarities, causing them to stretch and contract in opposite directions under the action of an electric field.

[0017] In some embodiments of the present invention, the one-way valve module further includes a valve cavity plate disposed on the side of the diaphragm valve away from the air intake plate, the holes on the diaphragm valve are staggered with the air intake holes, the diaphragm valve is attached to one side of the air intake plate and can deform in a direction away from the air intake plate under the action of external force, and the valve cavity plate has an air outlet window for airflow to be discharged.

[0018] In some embodiments of the present invention, a jet plate is further included on the side of the valve cavity plate opposite to the diaphragm valve. The jet plate has jet holes corresponding to the air outlet window, and the cross-sectional area of ​​the jet holes is smaller than the cross-sectional area of ​​the air outlet window.

[0019] In some embodiments of the present invention, an outlet plate is further provided on the jet plate away from the one-way valve module, the outlet plate having a lateral outlet groove communicating with the jet hole.

[0020] The beneficial effects of this invention are as follows: By setting a groove on the side of the fan blade facing the diaphragm valve, the thickness of the fan blade is reduced, increasing the amplitude of the fan blade and thus increasing the air volume. On the other hand, the setting of the groove also improves the air volume and air pressure. Furthermore, by setting the diaphragm valve to open in one direction away from the blowing assembly, backflow can be effectively suppressed. Compared with the prior art, it can not only effectively control the airflow direction, but also increase the air volume, thereby improving the overall airflow output and thus improving the heat dissipation efficiency of the piezoelectric fan. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the piezoelectric fan in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the exploded disassembly structure of the piezoelectric fan in an embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional view of the blower assembly and the one-way valve module in an embodiment of the present invention.

[0025] Figure 4 This is a dual-crystal structure of the piezoelectric element in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the operating structure of the piezoelectric element in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the one-way air outlet structure of the one-way valve module in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the exploded disassembly structure of a piezoelectric fan in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1. Blowing assembly; 11. Fan blade; 11a. Fixing part; 11b. Swinging part; 11c. Groove; 11c1. Flow suppression groove; 11c2. Amplifying groove; 12. Piezoelectric element; 2. One-way valve module; 21. Diaphragm valve; 22. Air inlet plate; 22a. Air inlet groove; 22b. Air inlet hole; 23. Valve chamber plate; 23a. Air outlet window; 3. Jet plate; 31. Jet hole; 4. Air outlet plate; 41. Lateral air outlet groove; 5. Support frame; 6. Air inlet cover. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] 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.

[0032] 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 in this specification 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.

[0033] In this embodiment of the invention, by optimizing the fan blade structure and improving the arrangement structure of the piezoelectric element, and then introducing a one-way valve module, the airflow delivery efficiency is improved, the hot air recirculation is reduced, and the heat dissipation capacity is improved. The embodiments of the present invention will be described in detail below.

[0034] like Figures 1 to 7 The piezoelectric fan shown includes a blowing assembly 1 and a one-way valve module 2, specifically as follows: Figure 1 and Figure 2 As shown, the blower assembly 1 includes a fan blade 11 and a piezoelectric element 12 disposed on the fan blade 11. The piezoelectric element 12 is attached to the fan blade 11 and is used to drive the fan blade 11 to reciprocate. It should be noted that, in the embodiments of the present invention, the fan blade 11 can be fixed to a bracket at one end, or it can be integrally formed on a metal sheet. Specifically, it can be adopted as follows: Figure 2 The structure shown suspends one end of the fan blade 11 by creating a C-shaped window on the metal sheet. It should be noted that the fan blade 11 can be single or multiple, depending on the heat dissipation requirements. The piezoelectric element 12 can be a piezoelectric ceramic sheet, which expands and contracts when energized, thus driving the reciprocating oscillation of the fan blade 11 to generate airflow. By using the piezoelectric element 12, a traditional motor is unnecessary, effectively reducing the size of the piezoelectric fan. Please continue to refer to... Figure 2 and Figure 3In an embodiment of the present invention, the one-way valve module 2 is fitted to the blower assembly 1 and includes a diaphragm valve 21 that opens unidirectionally in the direction away from the blower assembly 1. The one-way valve module 2 can take various forms, wherein the opening of the diaphragm valve 21 relies on the air pressure generated when the fan blades 11 fan towards the diaphragm valve 21. The opening of the diaphragm valve 21 can take various forms, such as opening by the oscillation of the valve blades or by changes in the gap between the valve blades and the orifice. In an embodiment of the present invention, to further increase the airflow and reduce backflow, such as... Figure 3 As shown, the fan blade 11 has a groove 11c on the side facing the diaphragm valve 21. Figure 3 As shown, by setting the groove 11c, on the one hand, the air storage capacity at the bottom of the fan blade 11 can be increased, thereby providing a greater wind speed when fanning downwards. On the other hand, by setting the groove 11c, the wind in the groove 11c can also be blocked, reducing the backflow of airflow from the swing end of the fan blade 11, thereby increasing the wind pressure and air volume.

[0035] In the above embodiment, by setting the groove 11c on the side of the fan blade 11 facing the diaphragm valve 21, the thickness of the fan blade 11 is reduced, the amplitude of the fan blade 11 is increased, thereby increasing the air volume. On the other hand, the setting of the groove 11c also improves the air volume and air pressure. Furthermore, by setting the diaphragm valve 21 which opens in one direction away from the blower assembly 1, backflow can be effectively suppressed. Compared with the prior art, it can not only effectively control the airflow direction, but also increase the air volume, thereby improving the overall airflow output and thus improving the heat dissipation efficiency of the piezoelectric fan.

[0036] Furthermore, in the embodiments of this application, please continue to refer to... Figure 1 It also includes a support frame 5 disposed on the side of the blower assembly 1 away from the one-way valve module 2 and an air inlet cover 6 attached to the support frame 5. The thickness of the support frame 5 is not less than the amplitude of one side of the fan blade 11, so as to provide space for the vibration above the fan blade 1. The air inlet cover 6 has an air inlet channel, and those skilled in the art can choose to inlet air from the top or the side as needed. Through the setting of the support frame 5 and the air inlet cover 6, space can be provided for the vibration of the blower assembly 1 and the fan blade 11 can be protected.

[0037] Optionally, in some embodiments of the present invention, the fan blade 11 includes a fixed portion 11a and a swing portion 11b. The swing portion 11b is connected to the fixed portion 11a and suspended. A piezoelectric element 12 is attached to the swing portion 11b to drive the swing portion 11b to reciprocate in the thickness direction. Figure 3 As shown in the embodiment of the present invention, the piezoelectric element 12 is attached to the swing portion 11b of the fan blade 11 near the fixing portion 11a, so as to... Figure 3Taking the piezoelectric element 12 as an example, when the piezoelectric element 12 contracts, its length shortens, causing the fan blade 11 to be subjected to an upward force, which in turn causes the swing portion 11b of the fan blade 11 to tilt upward. When the piezoelectric element 12 extends, the swing portion 11b of the fan blade 11 bends downward. Thus, when the piezoelectric element 12 is repeatedly excited, the fan blade 11 will generate reciprocating vibration. In the embodiment of the present invention, the driving frequency of the fan blade 11 exceeds 20kHz, which is in the ultrasonic stage. It is basically free of noise during operation, eliminating noise pollution and providing a quiet heat dissipation solution.

[0038] Optionally, in embodiments of the present invention, the specific location of the groove 11c is as follows: Figure 3 As shown, a groove 11c is provided on the swing part 11b, including a flow-damping groove 11c1 near the suspended end of the swing part 11b. Here, the flow-damping groove 11c1 refers to the distal end near the swing part 11b, which is the end away from the fixed part 11a, and a step is formed at the distal end. Thus, when the fan blade 11 changes from moving upwards to moving downwards, it can prevent the airflow from flowing out. Figure 3 As shown by the curved arrow, the recirculated gas can form an air curtain, which can further reduce the lateral movement of the airflow along the bottom of the fan blade 11, so that more gas is subjected to the downward pressure of the fan blade 11. This pressure can provide greater wind pressure compared to the structure of the fan blade 11 without the flow suppression groove 11c1, thereby opening the one-way valve module 2 in advance, so that more airflow flows out from the opened diaphragm valve 21.

[0039] Optionally, in an embodiment of the present invention, the groove 11c further includes an amplification groove 11c2 disposed near the fixing part 11a. Here, the amplification groove 11c2 refers to a groove disposed near the fixing part 11a. This type of groove can reduce the rigidity of the fan blade 11, thereby increasing the amplitude of the swinging part 11b during swinging. Of course, it should be noted that the flow-suppressing groove 11c1 disposed near the end of the swinging part 11b also has the effect of increasing the swinging amplitude of the swinging part 11b.

[0040] To further reduce gas recirculation and increase heat dissipation efficiency, such as Figure 2 and Figure 3 As shown, the one-way valve module 2 also includes an air inlet plate 22, which is sandwiched between the blower assembly 1 and the diaphragm valve 21. The air inlet plate 22 has an air inlet groove 22a facing the fan blade 11. It should be noted that, in this embodiment of the invention, the air inlet groove 22a can introduce more gas into the diaphragm valve 21 and also provides a vibratory space for the downward oscillation of the fan blade 11. In this embodiment of the invention, the air inlet groove 22a is correspondingly arranged with the oscillating part 11b, and the depth of the air inlet groove 22a is adapted to the vibration amplitude of the oscillating part 11b. Figure 3As shown, the "corresponding" here refers to the fact that the width of the air intake groove 22a is slightly larger than the width of the swing portion 11b of the fan blade 11. With this structural design, more gas can enter the air intake groove 22a during the downward pressing of the fan blade 11, and then be further compressed by the fan blade 11 within the air intake groove 22a. This compression allows the diaphragm valve 21 to remain open for a longer period, resulting in a larger ventilation volume. Further details can be found by referring to... Figure 3 In an embodiment of the present invention, the air inlet groove 22a also has an air inlet hole 22b, which is arranged opposite to the flow suppression groove 11c1. Here, "opposite" means that when the fan blade 11 is in a horizontal state, the width of the flow suppression groove 11c1 and the arrangement area of ​​the air inlet hole 22b are similar, or the width of the flow suppression groove 11c1 is slightly larger than the overall width of the air inlet hole 22b. With this structural configuration, as mentioned above, the air pressure at the flow suppression groove 11c1 is relatively high. By being arranged opposite to the air inlet hole 22b, a larger airflow can directly enter the air inlet hole 22b to open the diaphragm valve 21. The remaining gas enters the air inlet hole 22b during the mutual compression process between the fan blade 11 and the air inlet groove 22a. Through this configuration, the diaphragm valve 21 can be directly opened by the positive pressure of the flow suppression groove 11c1, and remains open during the subsequent compression process between the fan blade 11 and the air inlet groove 22a, thereby further improving the opening time and air output of the diaphragm valve 21. Furthermore, it should be noted that the one-way valve module 2 not only effectively controls the direction of airflow but also ensures the stability of the airflow. In each cycle, the regularity and continuity of the airflow are enhanced. For example, when the fan blade 11 changes from downward pressure to upward pressure, due to the action of the one-way valve, the gas will not flow back from the air inlet 22b but will be drawn from the outside of the air inlet slot 22a into the space between the fan blade 11 and the air inlet slot 22a. Through this structural design, the fan blade 11 can output airflow more evenly and continuously, reducing airflow fluctuations or instability.

[0041] Optionally, in some embodiments of the present invention, in order to further increase the fan amplitude of the fan blades 11, such as... Figure 4 and Figure 5 As shown, the piezoelectric element 12 is a bicrystalline piezoelectric ceramic, respectively attached to both sides of the fan-shaped plate 11 in the thickness direction. The bicrystalline piezoelectric ceramics have opposite polarities, causing them to expand and contract in opposite directions under the action of an electric field. In embodiments of the present invention, by employing bicrystalline piezoelectric ceramics, such as... Figure 5As shown, when the upper piezoelectric ceramic contracts, the lower piezoelectric ceramic extends, resulting in a greater bending effect on the fan blade 11. Furthermore, in embodiments of the invention, multiple piezoelectric ceramics can be connected in series along the expansion and contraction direction on the same surface of the fan blade 11, or multiple piezoelectric ceramics can be stacked and arranged side-by-side. This structural form can also provide greater mechanical gain, making the total displacement greater than the expansion and contraction displacement of the block, thereby allowing the fan blade 11 to provide a greater oscillation amplitude, and thus increasing the airflow of the piezoelectric fan.

[0042] Regarding the specific structure of the valve plate module, in some embodiments of the present invention, such as... Figure 6 As shown, the one-way valve module 2 also includes a valve chamber plate 23 disposed on the side of the diaphragm valve 21 away from the air intake plate 22. The holes on the diaphragm valve 21 are staggered with the air intake holes 22b. The diaphragm valve 21 is attached to one side of the air intake plate 22 and can deform away from the air intake plate 22 under external force. The valve chamber plate 23 has an air outlet window 23a for airflow discharge. Figure 6 As shown, the holes on the diaphragm valve 21 are staggered with the air inlet 22b, so that when air is introduced into the air inlet 22b under the pressure of the fan blade 11, the diaphragm valve 21 can deform in a direction away from the air inlet plate 22. Figure 6 As shown in the diagram above, the diaphragm valve 21 bends downwards, allowing gas from the inlet port 22b to enter the valve chamber plate 23 and exit through the outlet window 23a. When the fan blade 11 bends upwards, the diaphragm valve 21 returns to its original contact with the bottom of the inlet plate 22, as shown in the diagram. Figure 6 As shown in the figure below, the gas cannot flow in reverse; it should be noted that in the embodiments of the present invention, there are no restrictions on the number, shape and distribution of the orifices on the diaphragm valve 21.

[0043] Optionally, in some embodiments of the present invention, in order to further increase the outlet air flow rate, such as... Figure 7 As shown, it also includes a jet plate 3 attached to the side of the valve chamber plate 23 opposite to the diaphragm valve 21. The jet plate 3 has jet holes 31 corresponding to the air outlet window 23a, and the cross-sectional area of ​​the jet holes 31 is smaller than that of the air outlet window 23a. Of course, it should be noted that, in addition to having a smaller diameter, the jet holes 31 can also be designed as a constricted type, so that the airflow is accelerated as it passes through the jet holes 31, thereby improving the fan's wind speed output and heat dissipation efficiency.

[0044] In the embodiments of the present invention, please continue to refer to Figure 7It also includes an air outlet plate 4 attached to the jet plate 3 away from the one-way valve module 2. The air outlet plate 4 has a side air outlet groove 41 that communicates with the jet hole 31. Here, the side air outlet groove 41 means that the top is open and communicates with the jet hole 31, and the side wall of the air outlet plate 4 is open, so that the airflow can be discharged from the side. With this structural form, the air outlet plate 4 can be directly attached to the heat source, so that the continuous airflow can carry away the heat emitted from the heat source and improve the heat dissipation efficiency.

[0045] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A piezoelectric fan, characterized in that, include: A blower assembly, comprising a fan blade and a piezoelectric element disposed on the fan blade, the piezoelectric element being attached to the fan blade for driving the fan blade to reciprocate. A one-way valve module, which is fitted to the blower assembly, includes a diaphragm valve that opens in one direction away from the blower assembly; The fan blade includes a fixed part and a swinging part. The swinging part is connected to the fixed part and is suspended. The piezoelectric element is attached to the swinging part to drive the swinging part to reciprocate in the thickness direction. The fan blade has a groove on the side facing the diaphragm valve. The groove is disposed on the rocking part and includes a flow-suppressing groove near the suspended end of the rocking part. The one-way valve module also includes an air intake plate sandwiched between the blower assembly and the diaphragm valve. The air intake plate has an air intake groove facing the fan blades. The air intake groove is correspondingly arranged with the swing part. The depth of the air intake groove is adapted to the vibration amplitude of the swing part. The air intake groove also has an air intake hole. The holes on the diaphragm valve are staggered with the air intake holes. The diaphragm valve is attached to one side of the air intake plate and can deform away from the air intake plate under the action of external force. The air inlet and the flow suppression groove are arranged opposite to each other, so that during the downward pressing of the fan blade, the airflow with higher pressure at the flow suppression groove enters the air inlet and opens the diaphragm valve, and the remaining gas enters the air inlet as the fan blade and the air inlet groove approach and squeeze.

2. The piezoelectric fan according to claim 1, characterized in that, The piezoelectric element is a bicrystalline piezoelectric ceramic, which is attached to both sides of the fan blade in the thickness direction. The bicrystalline piezoelectric ceramics have opposite polarities, causing them to expand and contract in opposite directions under the action of an electric field.

3. The piezoelectric fan according to claim 1, characterized in that, The one-way valve module also includes a valve chamber plate disposed on the side of the diaphragm valve away from the air inlet plate, and the valve chamber plate has an air outlet window for airflow to be discharged.

4. The piezoelectric fan according to claim 3, characterized in that, It also includes a jet plate attached to the side of the valve chamber plate opposite to the diaphragm valve, the jet plate having jet holes corresponding to the air outlet window, and the cross-sectional area of ​​the jet holes being smaller than the cross-sectional area of ​​the air outlet window.

5. The piezoelectric fan according to claim 4, characterized in that, It also includes an air outlet plate attached to the jet plate away from the one-way valve module, the air outlet plate having a lateral air outlet groove communicating with the jet hole.

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