Heat dissipation structure, electronic device, heat dissipation system, and control method

Abstract

A heat dissipation structure, an electronic device, a heat dissipation system and a control method. The heat dissipation structure comprises a heat dissipation cavity (3), and a piezoelectric fan (4) and an air guide mechanism (5) which are located in the heat dissipation cavity (3), wherein the heat dissipation cavity (3) has an air inlet (10) and an air outlet (11); one end of the piezoelectric fan (4) is arranged on a cavity wall of the heat dissipation cavity (3) and is close to the air inlet (10), and the other end thereof extends to the air outlet (11); the air guide mechanism (5) is located between the piezoelectric fan (4) and the air outlet (11), and the air guide mechanism (5) is configured to guide an airflow to flow to the air outlet (11); and the piezoelectric fan (4) has a power-on state and a power-off state, and when in the power-on state, the end of the piezoelectric fan (4) close to the air outlet (11) swings, so as to generate an airflow flowing to the air guide mechanism (5). By means of the heat dissipation structure of the present example, local air can be rapidly compressed, such that a jet flow is formed; and a high-speed flow field can be achieved, thereby realizing efficient heat dissipation.

Description

Heat dissipation structure, electronic equipment, heat dissipation system and control method Technical Field

[0001] The present disclosure relates to, but is not limited to, the field of heat dissipation technology, and in particular to a heat dissipation structure, electronic equipment, a heat dissipation system, and a control method. Background Art

[0002] As the performance of electronic products gradually improves, their power consumption also increases, which in turn leads to the problem of heat dissipation. Most of the energy consumed by electronic products is ultimately dissipated as heat. Currently, existing electronic products mostly dissipate heat by improving the efficiency of convective heat transfer, that is, by adding fans to achieve heat dissipation. However, commonly used axial flow fans take up a lot of space and are noisy, making them unsuitable in many situations, such as mobile phones and televisions, where space is limited and these devices have heat dissipation issues.

[0003] Summary of the Invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] The embodiment of the present disclosure provides a heat dissipation structure, which includes a heat dissipation cavity, and a piezoelectric fan and an air guide mechanism located in the heat dissipation cavity;

[0006] The heat dissipation cavity has an air inlet and an air outlet;

[0007] One end of the piezoelectric fan is arranged on the cavity wall of the heat dissipation cavity and close to the air inlet, and the other end extends toward the air outlet;

[0008] The air guide mechanism is located between the piezoelectric fan and the air outlet, and the air guide mechanism is configured to guide airflow toward the air outlet;

[0009] The piezoelectric fan includes a power-on state and a power-off state. In the power-on state, the piezoelectric fan swings at one end close to the air outlet to generate an air flow toward the air guide mechanism.

[0010] In some exemplary embodiments, the air outlet is located at one end of the heat dissipation cavity in the first direction;

[0011] The piezoelectric fan comprises a fan body and a piezoelectric mechanism, wherein the fan body extends along the first direction and the piezoelectric mechanism is attached to the fan body;

[0012] In the power-on state, the fan body swings in a second direction, which is perpendicular to the first direction.

[0013] In some exemplary embodiments, one end of the fan body away from the air outlet is fixed to the cavity wall of the heat dissipation cavity, and the other end is suspended in the air to form a cantilever structure.

[0014] In some exemplary embodiments, the piezoelectric fan further comprises a fixing block, the fixing block being located at one end of the fan body close to the air inlet and at one side of the fan body in the second direction, the fan body being fixed to the cavity wall of the heat dissipation cavity through the fixing block;

[0015] The piezoelectric mechanism is located on a side of the fan body away from the fixing block in the second direction.

[0016] In some exemplary embodiments, the cavity wall of the heat dissipation cavity includes a top wall and a bottom wall spaced apart in the second direction;

[0017] The bottom wall includes a first inclined surface, the first inclined surface is located between the air inlet and the air outlet, the first inclined surface is configured to extend along the first direction and be inclined toward one side of the second direction, and the distance between the top wall and the first inclined surface in the second direction is configured to increase linearly from the air inlet to the air outlet;

[0018] One end of the fan body is fixed to an end of the first inclined surface close to the air inlet.

[0019] In some exemplary embodiments, the cavity wall of the heat dissipation cavity includes a top wall and a bottom wall spaced apart in the second direction;

[0020] The fan body is configured to be fixed on the top wall, and when powered on, the fan body is configured to swing toward a side close to the bottom wall;

[0021] Alternatively, the fan body is configured to be fixed on the bottom wall, and in a power-on state, the fan body is configured to swing toward a side close to the top wall.

[0022] In some exemplary embodiments, the fan body is configured to be plate-shaped, and the thickness of the fan body is configured to be greater than 100 microns;

[0023] The piezoelectric mechanism is configured to be in a plate shape, and the thickness of the piezoelectric mechanism is configured to be greater than 100 microns.

[0024] In some exemplary embodiments, the fan body swings in the second direction with an amplitude greater than 20 micrometers.

[0025] In some exemplary embodiments, an extension length of the piezoelectric fan in the first direction is set to be no greater than 20 mm.

[0026] In some exemplary embodiments, in a power-on state, the oscillation frequency of the fan body is set to a first-order resonant frequency or a multi-order resonant frequency.

[0027] In some exemplary embodiments, the fan body is made of metal or ceramic, the piezoelectric mechanism is bonded to the fan body, and the piezoelectric mechanism is configured to be glued or directly sintered on the fan body.

[0028] In some exemplary embodiments, the air guide mechanism includes a plurality of air guide plates, the air guide plates are arranged to extend along the first direction, and the plurality of air guide plates are spaced apart in a third direction, and the third direction is perpendicular to the first direction and the second direction;

[0029] An air duct extending along the first direction is formed between adjacent air guide plates.

[0030] In some exemplary embodiments, the width of the air duct in the third direction is configured to be linearly narrowed from an end close to the piezoelectric fan to an end close to the air outlet.

[0031] In some exemplary embodiments, the air duct includes a middle portion, and the middle portion is located in the center of the air duct in the first direction;

[0032] The width of the air duct in the third direction is configured to be linearly narrowed from one end close to the piezoelectric fan to the middle portion;

[0033] And / or, the width of the air duct in the third direction is configured to be linearly narrowed from one end close to the air outlet toward the middle portion.

[0034] In some exemplary embodiments, the invention further comprises a base and an upper cover, wherein the base is provided with an opening, the upper cover is configured to cover the opening, and the base and the upper cover enclose the heat dissipation cavity;

[0035] The air inlet is arranged at one end of the base or the upper cover in the first direction, and the air outlet is arranged at the other end of the base in the second direction.

[0036] In some exemplary embodiments, a plurality of the piezoelectric fans are provided, and the plurality of piezoelectric fans are spaced apart in a third direction, where the third direction is perpendicular to the first direction and the second direction.

[0037] An embodiment of the present disclosure provides an electronic device, which includes the above-mentioned heat dissipation structure, as well as a heating device, a heat conduction mechanism and a radiator. The two ends of the heat conduction mechanism are respectively connected to the heating device and the radiator, and the air outlet of the heat dissipation structure is arranged corresponding to the radiator.

[0038] An embodiment of the present disclosure provides a heat dissipation system, which includes a control module, a detection module and the above-mentioned heat dissipation structure, wherein the control module is electrically connected to the detection module and the heat dissipation structure respectively;

[0039] The detection module is configured to obtain detection data, wherein the detection data at least includes the air output of the heat dissipation structure and the temperature of the heating device;

[0040] The control module is configured to control the oscillation frequency of the piezoelectric fan.

[0041] The present disclosure provides a control method, which is applied to the above-mentioned heat dissipation system, and includes:

[0042] The control module controls the piezoelectric fan to turn on and swing at a first preset frequency;

[0043] When the detection module detects that a first preset condition is met, the control module controls the piezoelectric fan to swing at a second preset frequency. The first preset condition includes the temperature of the heating device and the air output of the heat dissipation structure.

[0044] In some exemplary embodiments, the heat dissipation structure includes a plurality of piezoelectric fans, and the control method further includes:

[0045] After the control module controls the piezoelectric fans to swing at a second preset frequency, the detection module detects that the temperature of the heating element reaches a preset temperature, and the control module controls to turn off a preset number of piezoelectric fans.

[0046] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description.

[0047] Summary of the Figures

[0048] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation to the technical solution of the present disclosure.

[0049] FIG1 is a first schematic diagram of a heat dissipation structure in this exemplary embodiment;

[0050] FIG2 is a partial cross-sectional view of the heat dissipation structure in FIG1 ;

[0051] FIG3 is a schematic cross-sectional view of a heat dissipation structure in this exemplary embodiment;

[0052] FIG4 is a second schematic diagram of a heat dissipation structure in this exemplary embodiment;

[0053] FIG5 is a schematic diagram of the disassembly of the heat dissipation structure in FIG1 ;

[0054] FIG6 is a schematic diagram of the installation of a piezoelectric fan in this exemplary embodiment;

[0055] FIG7 is a schematic diagram of the piezoelectric fan in FIG6 in a power-off state;

[0056] FIG8 is a first schematic diagram of the piezoelectric fan in FIG6 in a power-on state;

[0057] FIG9 is a second schematic diagram of the piezoelectric fan in FIG6 in a power-on state;

[0058] FIG10 is a schematic diagram of a first-order resonance state of a piezoelectric fan according to this exemplary embodiment;

[0059] FIG11 is a schematic diagram of a second-order resonance state of another piezoelectric fan according to this exemplary embodiment;

[0060] FIG12 is a schematic diagram of a third-order resonance state of another piezoelectric fan according to this exemplary embodiment;

[0061] FIG13 is a partial schematic diagram of a heat dissipation structure of this exemplary embodiment;

[0062] FIG14 is a partial schematic diagram of another heat dissipation structure of this exemplary embodiment;

[0063] FIG15 is a partial schematic diagram of another heat dissipation structure of this exemplary embodiment;

[0064] FIG16 is a schematic diagram of another heat dissipation structure of this exemplary embodiment;

[0065] FIG17 is a schematic diagram of another heat dissipation structure of this exemplary embodiment;

[0066] FIG18 is a schematic diagram of another heat dissipation structure of this exemplary embodiment;

[0067] FIG19 is a schematic diagram of an electronic device according to this exemplary embodiment;

[0068] FIG20 is a schematic diagram of a heat dissipation system according to this exemplary embodiment;

[0069] FIG21 is a schematic diagram of a control method of this exemplary embodiment.

[0070] Description of the accompanying drawings:

[0071] 1-Upper cover; 2-Base; 3-Heat dissipation cavity;

[0072] 4-piezoelectric fan; 5-air guide mechanism; 6-base plate;

[0073] 7-first side wall; 8-second side wall; 9-opening;

[0074] 10-air inlet; 11-air outlet; 12-first opening;

[0075] 13-second opening; 14-air guide plate; 15-air duct;

[0076] 16- fan body; 17- piezoelectric mechanism; 18- fixing block;

[0077] 19-top wall; 20-bottom wall; 21-first cavity;

[0078] 22-second cavity; 23-first space; 24-first inclined surface;

[0079] 25-middle part; 26-heat dissipation structure; 27-heating device;

[0080] 28-heat conduction mechanism; 29-heat sink; 30-control module;

[0081] 31-Detection module; 32-Power module.

[0082] Details

[0083] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the embodiments can be implemented in a variety of different forms. A person of ordinary skill in the art can easily understand the fact that the methods and contents can be transformed into various forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other.

[0084] The scale of the figures in this disclosure can be used as a reference in actual processes, but is not limited to this. For example, the width-to-length ratio of the channel, the thickness and spacing of each film layer, and the width and spacing of each signal line can be adjusted according to actual needs. The number of pixels in the heat dissipation structure and the number of sub-pixels in each pixel are not limited to the numbers shown in the figures. The figures described in this disclosure are only structural schematics, and one embodiment of the present disclosure is not limited to the shapes or values ​​shown in the figures.

[0085] In this specification, ordinal numbers such as “first”, “second” and “third” are provided to avoid confusion among constituent elements, and are not intended to limit the number.

[0086] In this specification, for convenience, words and phrases indicating orientation or positional relationships, such as "middle," "upper," "lower," "front," "back," "vertical," "horizontal," "top," "bottom," "inside," and "outside," are used to illustrate the positional relationships of constituent elements with reference to the accompanying drawings. This is merely for the purpose of facilitating the description of this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present disclosure. The positional relationships of constituent elements may be appropriately changed depending on the direction in which each constituent element is described. Therefore, the present disclosure is not limited to the words and phrases described in the specification and may be appropriately replaced according to the circumstances.

[0087] In this specification, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct connections, indirect connections through intermediaries, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0088] In this specification, "electrically connected" includes components connected together via an element having some electrical function. There are no particular limitations on the "element having some electrical function" as long as it enables the transfer of electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other components with various functions.

[0089] In this specification, "parallel" refers to a state where the angle formed by two straight lines is greater than -10° and less than 10°, and thus also includes a state where the angle is greater than -5° and less than 5°. Furthermore, "perpendicular" refers to a state where the angle formed by two straight lines is greater than 80° and less than 100°, and thus also includes a state where the angle is greater than 85° and less than 95°.

[0090] In this specification, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may be replaced with "conductive film." Similarly, "insulating film" may be replaced with "insulating layer."

[0091] The triangles, rectangles, trapezoids, pentagons or hexagons in this specification are not in the strict sense, but may be approximate triangles, rectangles, trapezoids, pentagons or hexagons, etc. There may be some small deformations caused by tolerances, and there may be chamfers, arc edges and deformations.

[0092] The term "about" in the embodiments of the present disclosure does not strictly define the limits and allows for numerical values ​​within the range of process and measurement errors.

[0093] Currently, energy consumed by electronic devices is primarily dissipated as heat. These electronic devices primarily rely on natural convection for heat transfer. However, natural convection has very low heat transfer efficiency and can only remove a very limited amount of heat. Given a constant heat dissipation area, increasing heat transfer can only be achieved by increasing the heat transfer coefficient and increasing the temperature difference. Increasing the temperature difference significantly impacts the lifespan of consumer electronics, so air cooling, which improves the heat transfer coefficient, has become the primary convection cooling solution. Applicants have discovered that adding a fan can dissipate heat. However, conventional axial fans are too large, requiring a minimum thickness of 5 mm. Many ultra-thin electronic products lack the necessary thickness to accommodate such fans. Conventional axial fans are also noisy, and the presence of rotating components creates significant noise during high-load operation, which can impact quiet environments or applications involving audio information. Consequently, current mainstream fans are unsuitable for devices with small footprints, such as mobile phones and televisions. These devices cannot be cooled by conventional fans, making heat dissipation a major issue for these devices. Poor heat dissipation can directly impact device operation, even causing damage, and negatively impacting user experience.

[0094] FIG1 is a first schematic diagram of a heat dissipation structure according to an exemplary embodiment. FIG2 is a partial cross-sectional view of the heat dissipation structure in FIG1 . FIG3 is a schematic cross-sectional view of a heat dissipation structure according to an exemplary embodiment. This exemplary embodiment provides a heat dissipation structure. As shown in FIG1 to FIG3 , the heat dissipation structure may include a heat dissipation cavity 3, a piezoelectric fan 4 located within the heat dissipation cavity 3, and an air guide mechanism 5. The heat dissipation cavity 3 has an air inlet 10 and an air outlet 11. One end of the piezoelectric fan 4 may be disposed on the cavity wall of the heat dissipation cavity 3 near the air inlet 10, and the other end of the piezoelectric fan 4 extends toward the air outlet 11. The air guide mechanism 5 may be located between the piezoelectric fan 4 and the air outlet 11 and may guide airflow toward the air outlet 11. The piezoelectric fan 4 may have an energized state and an energized state. In the energized state, the end of the piezoelectric fan 4 near the air outlet 11 may swing, thereby generating airflow toward the air guide mechanism 5. Therefore, the heat dissipation structure of this example can utilize the resonance of the piezoelectric fan 4 to increase the air flow rate and improve the heat dissipation effect. Moreover, the piezoelectric fan 4 occupies a small space and has excellent noise control, and is suitable for devices with small spaces such as mobile phones, televisions, and notebooks.

[0095] Figure 4 is a second schematic diagram of a heat dissipation structure in this exemplary embodiment, Figure 5 is a schematic diagram of the disassembled heat dissipation structure in Figure 1, and Figure 6 is a schematic diagram of the installation of the piezoelectric fan in this exemplary embodiment. In some exemplary embodiments, as shown in Figures 1 to 6, the heat dissipation structure may include a base 2 and an upper cover 1, the base 2 may be groove-shaped, and an opening 9 is formed on the base 2, the upper cover 1 may be flat, and the outer contour of the upper cover 1 may be consistent with the size of the opening 9, and the upper cover 1 may be installed corresponding to the opening 9, thereby covering the opening 9, thereby, the base 2 and the upper cover 1 form a heat dissipation cavity 3. The base 2 may include a bottom plate 6, a first side plate 7, and a second side plate 8. The bottom plate 6 may be perpendicular to the second direction and may be a rectangular plate. The first side plate 7 and the second side plate 8 are respectively located at the two ends of the bottom plate 6 in the third direction and are located on the same side of the bottom plate 6 in the second direction. The first side plate 7 and the second side plate 8 may both be perpendicular to the bottom plate 6. The first side plate 7 and the second side plate 8 may both extend along the first direction. The first side plate 7 and the second side plate 8 form an opening 9 on the side away from the bottom plate 6. The second direction and the third direction are both perpendicular to the first direction, and the second direction is perpendicular to the third direction. The base 2 has a first opening 12 and a second opening 13 at both ends of the first direction, respectively, for connecting the heat dissipation chamber 3 to the outside world. The first opening 12 constitutes an air inlet 10, and the second opening 13 constitutes an air outlet 11, so that the air inlet 10 and the air outlet 11 are respectively located at the two ends of the heat dissipation chamber 3 in the first direction. The end surface of the bottom plate 6 facing the upper cover 1 forms the bottom wall 20 of the heat dissipation cavity 3, and the end surface of the upper cover 1 facing the bottom plate 6 forms the top wall 19 of the heat dissipation cavity 3. The bottom wall 20 and the top wall 19 both serve as cavity walls of the heat dissipation cavity 3, and the bottom wall 20 and the top wall 19 are spaced apart in the second direction. Furthermore, the heat dissipation cavity 3 can be divided into a first cavity 21 and a second cavity 22, which are arranged sequentially in the first direction. The air guide mechanism 5 can be located in the second cavity 22, and the piezoelectric fan 4 can be located in the first cavity 21.

[0096] FIG7 is a schematic diagram of the piezoelectric fan of FIG6 in a power-off state. In some exemplary embodiments, as shown in FIG2 , FIG3 , FIG6 , and FIG7 , the piezoelectric fan 4 may include a fan body 16, a piezoelectric mechanism 17, and a fixing block 18. The fan body 16 extends along a first direction, and the piezoelectric mechanism 17 is attached to the fan body 16. One end of the fan body 16, away from the air outlet 11, is fixed to the wall of the heat dissipation chamber 3, while the other end is suspended in the air, forming a cantilever structure. The fan body 16 is made of metal or ceramic. In this example, the fan body 16 may be made of a metal such as aluminum, stainless steel, or alumina, or ceramic. The fan body 16 is capable of deforming to a certain extent and then returning to its original shape. The fan body 16 is flat and perpendicular to the second direction. In this example, the fan body 16 may be rectangular, but is not limited thereto. The shape of the fan body 16 can be adjusted to the shape of the heat dissipation chamber 3. For example, the fan body 16 may be an umbrella-shaped, trapezoidal, circular, or triangular plate. The thickness of the fan body 16 can be the minimum dimension of the fan body 16 in the second direction, that is, L2, where the value of L2 is greater than 100 microns; the length of the fan body 16 can be the dimension of the fan body 16 in the first direction (L1), and the length of the fan body 16 is not greater than 20 mm. In this example, the dimension of the fan body 16 in the first direction is L1, where L1 = 8 mm, but is not limited to this. For example, L1 can be 10 mm, 12 mm or 6 mm.

[0097] In some exemplary embodiments, as shown in Figures 2, 3, 6 and 7, the fixing block 18 is located at one end of the fan body 16 close to the air inlet 10 and is located on the side of the fan body 16 close to the bottom wall 20 in the second direction. The fixing block 18 can be connected to the fan body 16 and the bottom wall 20 respectively, so that the fan body 16 is fixed to the bottom wall 20 of the heat dissipation cavity 3 through the fixing block 18, so that the end of the fan body 16 away from the fixing block 18 is suspended in the air, and the fan body 16 has a certain deformation recovery ability, so that the end of the fan body 16 away from the fixing block 18 can swing under the action of external force.

[0098] In some exemplary embodiments, as shown in Figures 2, 3, 6, and 7, the piezoelectric mechanism 17 may be plate-shaped, with a thickness (L3) of greater than 100 microns, where the thickness of the piezoelectric mechanism 17 is the minimum dimension of the piezoelectric mechanism 17 in the second direction. The piezoelectric mechanism 17 may be located on a side of the fan body 16 that is away from the fixing block 18 in the second direction, and the area of ​​the piezoelectric mechanism 17 may be smaller than the area of ​​the fan body 16, i.e., the orthographic projection of the piezoelectric mechanism 17 on the bottom wall 20 is completely within the orthographic projection of the fan body 16 on the bottom wall 20. The piezoelectric mechanism 17 may be rectangular, and the piezoelectric mechanism 17 may fully cover the end surface of the fan body 16 away from the fixing block 18 in the third direction. The piezoelectric mechanism 17 may be attached to the fan body 16 and may be connected to the fan body 16 by gluing or direct sintering. The piezoelectric mechanism 17 may include two piezoelectric sheets (not shown) and an intermediate layer (not shown) positioned between the two piezoelectric sheets (not shown). The two piezoelectric sheets (not shown) and the intermediate layer (not shown) may be electrically connected to a power module. The piezoelectric sheets (not shown) may be piezoelectric materials, a class of materials with special properties that enable energy conversion between mechanical stress and voltage. When a voltage is applied to the two piezoelectric sheets (not shown) by the power module, the piezoelectric sheets (not shown) generate mechanical stress and deform, a phenomenon known as the inverse piezoelectric effect. When the two piezoelectric sheets (not shown) deform due to the inverse piezoelectric effect, the piezoelectric mechanism 17 can pull the fan body 16 to undergo the same deformation. Since one end of the fan body 16 is secured by a fixing block 18, the free end of the fan body 16 moves, causing the piezoelectric mechanism 17 to drive the fan body 16 to oscillate. Furthermore, the power module (not shown) can drive the fan body 16 to perform specific movements. Data such as the power supply voltage and voltage conversion speed of the power module (not shown) can directly influence the operating state of the fan body 16.

[0099] FIG8 is a first schematic diagram of the piezoelectric fan of FIG6 in the powered-on state, FIG9 is a second schematic diagram of the piezoelectric fan of FIG6 in the powered-on state, FIG10 is a schematic diagram of the first-order resonance state of one piezoelectric fan of this exemplary embodiment, FIG11 is a schematic diagram of the second-order resonance state of another piezoelectric fan of this exemplary embodiment, and FIG12 is a schematic diagram of the third-order resonance state of yet another piezoelectric fan of this exemplary embodiment. In some exemplary embodiments, as shown in FIG3 , FIG8 , and FIG9 , the power-off state may be the state of the piezoelectric fan when the power module (not shown) stops supplying voltage to the piezoelectric mechanism 17, and the power-on state may be the state of the piezoelectric fan when the power module (not shown) supplies voltage to the piezoelectric mechanism 17. In the power-off state, the fan body 16 remains stationary and is maintained perpendicular to the second direction based on the material hardness. In the power-on state, the power module (not shown) can supply voltage to the piezoelectric mechanism 17, causing the piezoelectric mechanism 17 to deform and pull the fan body 16 to swing, allowing the fan body 16 to swing in the second direction. By adjusting the voltage conversion speed of the power module (not shown in the figure), the swing speed of the fan body 16 can be changed. For example, the faster the voltage conversion speed, the faster the fan body 16 swings. By controlling the supply voltage of the power module (not shown in the figure), the swing amplitude of the fan body 16 can be controlled. For example, the greater the supply voltage of the power module (not shown in the figure), the greater the swing amplitude of the fan body 16. In order to achieve the best fan effect, it is necessary to select piezoelectric mechanisms 17 and fan bodies 16 of appropriate sizes to reach the optimal resonant frequency point of the piezoelectric material, and the working effect of the piezoelectric fan is in the best working state. In this example, the swing amplitude of the fan body 16 in the second direction is L4, where L4 is greater than 20 microns. Combined with the fact that the size of the fan body 16 in the first direction is less than 20 mm, the piezoelectric fan has a first-order resonant frequency as high as possible.

[0100] In some exemplary embodiments, as shown in Figures 3 and 8, the piezoelectric fan 4 is in a first position S1, which is the extreme position of the fan body 16 swinging on the side close to the top wall 19. When in the first position S1, the distance between the fan body 16 and the top wall 19 is the shortest; the swing amplitude of the fan body 16 is L4, which can be the distance in the second direction between the end of the fan body 16 away from the air inlet 10 in the first position S1 and the end of the fan body 16 away from the air inlet 10 in the power-off state. As shown in Figures 3 and 9, the piezoelectric fan 4 is in the second position S2, which is the extreme position of the fan body 16 swinging on the side close to the bottom wall 20. When in the second position S2, the distance between the fan body 16 and the bottom wall 20 is the shortest; in this position, the swing amplitude of the fan body 16 is also L4, and L4 can be the distance in the second direction between the end of the fan body 16 away from the air inlet 10 in the second position S2 and the end of the fan body 16 away from the air inlet 10 in the power-off state; in this position, the space in the heat dissipation cavity 3 between the fan body 16 and the bottom wall 20 is the first space 23. When powered on, the fan body 16 can reciprocate between the first position S1 and the second position S2, wherein the swing frequency of the fan body 16 can be the first-order resonant frequency. As shown in FIG10 , the swing of the fan body 16 is a reciprocating swing in both directions of up and down, but is not limited to this. For example, the swing frequency of the fan body 16 can be the second-order resonant frequency. As shown in FIG11 , the swing of the fan body 16 has two different vibration modes. For another example, the swing frequency of the fan body 16 can be the third-order resonant frequency. As shown in FIG12 , the swing of the fan body 16 has three different vibration modes.

[0101] Figure 13 is a partial schematic diagram of a heat dissipation structure of this exemplary embodiment. In some exemplary embodiments, as shown in Figure 13, the air inlet 10 is not set on the base 2. The air inlet 10 can be set at one end of the upper cover 1 in the first direction, so that the heat dissipation cavity 3 draws in cold air from one side of the upper cover 1.

[0102] FIG14 is a partial schematic diagram of another heat dissipation structure of this exemplary embodiment. Based on the ideal gas formula, the pressure and volume changes in the local enclosed space formed by the piezoelectric fan 4 and the heat dissipation cavity 3 during the swinging process satisfy the following formula 1:

[0103] Wherein, P0 is the initial pressure of the heat dissipation cavity 3, ΔP is the pressure change in the heat dissipation cavity 3, V is the volume of the heat dissipation cavity 3, ΔV is the volume change in the heat dissipation cavity 3, and k is the adiabatic index, which is approximately 1.4.

[0104] Taylor expansion of the right side of Formula 1 can yield Formula 2:

[0105] The amount of volume change (ΔV) can be determined by the swept area of ​​the piezoelectric fan 4 .

[0106] It can be seen that increasing the swept area of ​​the piezoelectric fan 4 (i.e. increasing the swing amplitude of the piezoelectric fan 4) and increasing the compression ratio (i.e. reducing stagnant air) can significantly improve the heat dissipation level of the device. As shown in Figures 2 and 9, for example, the air in the first space 23 is not flowing smoothly or is stagnant, which can act as stagnant air. Therefore, reducing the first space 23 can improve the heat dissipation level of the heat dissipation structure. In some exemplary embodiments, as shown in Figure 14, the bottom wall 20 of the heat dissipation cavity 3 may include a first inclined surface 24, and the first inclined surface 24 is located between the air inlet 10 and the air outlet 11. The first inclined surface 24 can be set to extend along the first direction and be inclined to one side of the second direction. The distance between the top wall 19 and the first inclined surface 24 in the second direction is set to increase linearly from the air inlet 10 to the air outlet 11 on the first defense line, so that the bottom wall 20 forms a sloped structure. One end of the fan body 16 is fixed to the end of the first inclined surface 24 near the air inlet 10. When the piezoelectric fan 4 is pressed down to the second position S2, the second position S2 can be the extreme swing position of the fan body 16 near the bottom wall 20. The space between the piezoelectric fan 4 and the bottom wall 20 is smaller, so that the piezoelectric fan 4 does not accumulate a lot of stagnant air below when pressed down, thereby effectively improving the heat dissipation effect of the heat dissipation structure. At the same time, an air guide mechanism 5 can be provided at the air outlet 11. The air guide mechanism 5 can assist in forming local air compression, increasing the outlet pressure and speed, so that after the air is locally compressed by the piezoelectric fan 4, it forms high-pressure gas and is blown out from the air outlet 11.

[0107] FIG15 is a partial schematic diagram of another heat dissipation structure of this exemplary embodiment. In some exemplary embodiments, as shown in FIG15 , the cavity wall of the heat dissipation cavity 3 may include a top wall 19 and a bottom wall 20 spaced apart in the second direction. The end of the piezoelectric fan 4 near the air inlet 10 is fixed to the bottom wall 20. The piezoelectric fan 4 extends along the first direction and is attached to the bottom wall 20. In the power-off state, the piezoelectric fan 4 remains stationary in the second position S2. In the power-on state, the piezoelectric fan 4 can swing toward the side near the top wall 19 until it reaches the first position S1. The piezoelectric fan 4 can reciprocate between the first position S1 and the second position S2. The first position S1 is the extreme swing position of the piezoelectric fan 4 near the top wall 19. When in the first position S1, the distance between the piezoelectric fan 4 and the top wall 19 is the shortest. The second position S2 is consistent with the position of the piezoelectric fan 4 in the power-off state. Thus, the piezoelectric fan 4 only swings in the second direction in the powered-on state relative to the powered-off state, i.e., a unidirectional swing is adopted to prevent the piezoelectric fan 4 from swinging to the other side, thereby ensuring sufficient compression of the air, simplifying the design, and reducing processing costs. However, this is not limited to the above. For example, the piezoelectric fan 4 may be fixed to the top wall 19 at one end near the air inlet 10, and the piezoelectric fan 4 may extend along the first direction and be attached to the top wall 19. In the powered-off state, the piezoelectric fan 4 remains stationary. In the powered-on state, the piezoelectric fan 4 is configured to swing toward the side near the bottom wall 20, also using a unidirectional swing.

[0108] In some exemplary embodiments, as shown in FIG6 , the air guide mechanism 5 may include a plurality of air guide plates 14 . The air guide plates 14 may be flat plates. The plurality of air guide plates 14 may extend in a first direction. The plurality of air guide plates 14 may be spaced apart in a third direction, such that the plurality of air guide plates 14 are parallel to each other and air ducts 15 are formed between adjacent air guide plates 14 . The air ducts 15 may extend in the first direction, and the plurality of air ducts 15 may be spaced apart in the third direction. As indicated by the dotted arrows, air is drawn into the heat dissipation cavity 3 through the air inlet 10, passes through the piezoelectric fan 4, the air duct 15, and the air outlet 11 in sequence, and flows out of the heat dissipation structure. The air guide mechanism 5 may assist in forming local air compression within the heat dissipation cavity 3, increasing the pressure and velocity at the air outlet 11, so that the air is locally compressed by the piezoelectric fan 4 to form high-pressure gas.

[0109] FIG16 is a schematic diagram of another heat dissipation structure of this exemplary embodiment. In some exemplary embodiments, as shown in FIG16 , the air duct 15 extends along a first direction, and multiple air ducts 15 are spaced apart along a third direction. The width of the air duct 15 in the third direction is L5. L5 linearly narrows in the first direction from the end near the piezoelectric fan 4 to the end near the air outlet 11, forming a trumpet-shaped air duct 15. The size of the air guide plate 14 in the third direction linearly widens from the end near the piezoelectric fan 4 to the end near the air outlet 11, forming a trumpet-shaped air duct 15 between two adjacent air guide plates 14. As shown in FIG8 , because the piezoelectric fan 4 vibrates reciprocatingly, a certain negative pressure is generated when it swings upward to the first position S1. This negative pressure drives the surrounding gas to replenish. Using an asymmetric air duct 15 structure as shown in FIG15 can, to a certain extent, induce the air to be replenished from the air outlet 11 as little as possible, thereby increasing the net air output per unit time.

[0110] FIG17 is a schematic diagram of another heat dissipation structure according to this exemplary embodiment. In some exemplary embodiments, as shown in FIG17 , an air duct 15 extends along a first direction, and multiple air ducts 15 are spaced apart along a third direction. Air duct 15 includes a middle portion 25 located at the center of air duct 15 in the first direction. The width of air duct 15 in the third direction is L5. The value of L5 in the first direction linearly narrows from the end of air duct 15 near piezoelectric fan 4 to middle portion 25. Furthermore, the value of L5 in the first direction linearly narrows from the end of air duct 15 near air outlet 11 to middle portion 25. Thus, air duct 15 employs a Laval tube structure. In the first direction, air duct 15 narrows from the end near piezoelectric fan 4 to middle portion 25, accelerating the airflow. The air duct 15 widens in the first direction from middle portion 25 to the end near air outlet 11, creating an expansion that reduces airflow pressure and helps form a higher-speed jet. Among them, the size of the air guide plate 14 in the third direction is L6, wherein L6 linearly widens from the end close to the piezoelectric fan 4 to the middle part 25 in the first direction, and then linearly narrows from the middle part 25 to the end close to the air outlet 11. Thus, an air duct 15 with a Laval tube structure is formed between two adjacent air guide plates 14.

[0111] In some exemplary embodiments, as shown in Figure 6, the piezoelectric fan 4 can form high-frequency resonance, the resonant frequency of the piezoelectric fan 4 is greater than 15kHz, and the swing amplitude of the piezoelectric fan 4 is greater than 20 microns. Combined with the heat dissipation cavity 3 with an air guide mechanism 5, local air can be quickly compressed to form a jet.

[0112] FIG18 is a schematic diagram of another heat dissipation structure of this exemplary embodiment. In some exemplary embodiments, as shown in FIG18 , a plurality of piezoelectric fans 4 may be provided, and the plurality of piezoelectric fans 4 may be arranged at intervals in the third direction. In this example, the number of piezoelectric fans 4 is three, but is not limited thereto. For example, the number of piezoelectric fans 4 may be two, four, or six, and is not limited to three. In addition, the swing amplitudes and swing frequencies of the plurality of piezoelectric fans 4 are the same, but are not limited thereto. For example, the swing amplitudes of the plurality of piezoelectric fans 4 are different, or the swing frequencies of the plurality of piezoelectric fans 4 are different, or the swing amplitudes and swing frequencies of the plurality of piezoelectric fans 4 are different. Thus, the plurality of piezoelectric fans 4 form a discrete structure, and the wind speed is controlled by controlling the number of piezoelectric fans 4 that are started, thereby rationally regulating the heat dissipation requirements and power consumption.

[0113] FIG19 is a schematic diagram of an electronic device according to this exemplary embodiment. In some exemplary embodiments, as shown in FIG19 , the electronic device may include a heat dissipation structure 26, a heating device 27, a heat conducting mechanism 28, and a heat sink 29. The ends of the heat conducting mechanism 28 may be connected to the heating device 27 and the heat sink 29, respectively. The air outlet 11 of the heat dissipation structure 26 may be positioned corresponding to the heat sink 29 so that air flowing out of the heat dissipation structure 26 can be directly blown onto the heat sink 29. The electronic device may be a mobile phone, tablet computer, television, monitor, laptop computer, navigation system, or other product or component, but this embodiment is not limited thereto. In this example, the electronic device may be a laptop computer, the heating element 27 may be a CPU, the heat conducting mechanism 28 may be a flat heat pipe, and the radiator 29 may be a finned heat sink. The flat heat pipe (heat conducting mechanism 28) is terminated with an integrated finned heat sink (heat sink 29) and a heat dissipation structure 26. The heat dissipation structure 26 is applied to the laptop computer, utilizing the flat heat pipe (heat conducting mechanism 28) to conduct heat from the CPU (heat generating element 27) to a location near the laptop computer's casing. The heat dissipation structure 26 then blows air through the finned heat sink (heat sink 29) to remove the heat from the laptop computer. Compared to conventional axial flow fan solutions, the heat dissipation structure 26 in this example occupies less space and can reduce the thickness of the electronic device. For example, under the condition of natural convection heat dissipation, at room temperature of 20°C, a 14-inch laptop can rely on single-sided heat exchange and an operating power of 20W, and the surface temperature of the laptop is 65.3°C. However, the same laptop adopting the present heat dissipation structure 26 can achieve a convection heat transfer coefficient of 22W / m2 / K, and the surface temperature of the laptop can be reduced to 34.7°C, which shows that the heat dissipation effect is obvious.

[0114] FIG20 is a schematic diagram of a heat dissipation system of this exemplary embodiment. This exemplary embodiment provides a heat dissipation system. As shown in FIG20 , the heat dissipation system may include a control module 30, a detection module 31, and a heat dissipation structure having a piezoelectric fan 4. The control module 30 may be electrically connected to the detection module 31 and the heat dissipation structure, respectively. The detection module 31 may obtain detection data and send the detection data to the control module 30. The detection data at least includes the air output of the heat dissipation structure 26 and the temperature of the heating device. The heat dissipation structure may have a power supply module 32. The piezoelectric fan 4 is powered by the power supply module 32, that is, the power supply module 32 provides voltage to the piezoelectric fan 4. The power supply module 32 may be electrically connected to the control module 30, so that the control module 30 may control the action of the power supply module 32 according to the detection data, thereby controlling the oscillation frequency of the piezoelectric fan 4.

[0115] FIG21 is a schematic diagram of a control method of the present exemplary embodiment. The exemplary embodiment provides a control method, which can be applied to the heat dissipation system shown in FIG20. As shown in FIG21, the control method may include: first, controlling the piezoelectric fan 4 to turn on and swing at a first preset frequency through the control module 30. The detection module 31 can monitor data in real time. When the detection module 31 detects that the first preset condition is met, the control module 30 controls the piezoelectric fan 4 to swing at a second preset frequency. The first preset condition may include the temperature of the heating device and the air output of the heat dissipation structure. Thus, the detection module 31 will detect whether the operating condition of the piezoelectric fan 4 has reached the optimal resonant state and feedback to the control module 30. The control module 30 will control the piezoelectric fan 4 and make small adjustments to the resonant frequency of the piezoelectric fan 4 until the optimal resonant state under the working condition is reached, thereby reducing power consumption.

[0116] In some exemplary embodiments, the heat dissipation structure may include a plurality of piezoelectric fans 4 as shown in FIG17 . As shown in FIG21 , the control method may include that after the control module 30 controls the piezoelectric fan 4 to swing at a second preset frequency, when the detection module 31 detects that the temperature of the heating device reaches a preset temperature, the control module 30 controls the shutdown of a preset number of piezoelectric fans 4. For example, when the detection module 31 detects that the temperature of the heating device reaches 60°C, the control module 30 controls the shutdown of one piezoelectric fan 4. According to the control method of this example, the temperature value of the heating device such as the CPU and the operating mode set by the user (high performance / energy saving / silent, etc.) determine whether to turn on or how many piezoelectric fans 4 to turn on. The control method of this example maintains real-time temperature detection. Once the required temperature value is reached, the number of piezoelectric fans 4 turned on will be balanced to reduce power consumption as much as possible while meeting the temperature.

[0117] In conjunction with the above-described embodiment, the piezoelectric fan 4 in the heat dissipation structure can generate high-frequency resonance. The resonant frequency of the piezoelectric fan 4 is greater than 15kHz, and the swing amplitude of the piezoelectric fan 4 is greater than 20 microns. Combined with the structure of the heat dissipation cavity 3, this can achieve rapid localized air compression, forming a jet. High-frequency resonance is achieved through optimization of the piezoelectric fan 4 and its materials, and high-speed flow is achieved through air duct design, resulting in efficient heat dissipation.

[0118] Although the embodiments disclosed in this disclosure are as described above, the contents described are merely embodiments adopted to facilitate understanding of the disclosure and are not intended to limit the disclosure. Any person skilled in the art to which the disclosure belongs may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope of the disclosure. However, the scope of patent protection of the present invention shall still be based on the scope defined by the appended claims.

Claims

1. A heat dissipation structure, wherein: It includes a heat dissipation cavity, and a piezoelectric fan and an air guide mechanism located in the heat dissipation cavity; The heat dissipation cavity has an air inlet and an air outlet; One end of the piezoelectric fan is arranged on the cavity wall of the heat dissipation cavity and close to the air inlet, and the other end extends toward the air outlet; The air guide mechanism is located between the piezoelectric fan and the air outlet, and the air guide mechanism is configured to guide airflow toward the air outlet; The piezoelectric fan includes a power-on state and a power-off state. In the power-on state, the piezoelectric fan swings at one end close to the air outlet to generate an air flow toward the air guide mechanism.

2. The heat dissipation structure according to claim 1, wherein: The air outlet is located at one end of the heat dissipation cavity in the first direction; The piezoelectric fan comprises a fan body and a piezoelectric mechanism, wherein the fan body extends along the first direction and the piezoelectric mechanism is attached to the fan body; In the power-on state, the fan body swings in a second direction, which is perpendicular to the first direction.

3. The heat dissipation structure according to claim 2, wherein: One end of the fan body away from the air outlet is fixed to the cavity wall of the heat dissipation cavity, and the other end is suspended in the air to form a cantilever structure.

4. The heat dissipation structure according to claim 3, wherein: The piezoelectric fan further includes a fixing block, the fixing block being located at one end of the fan body close to the air inlet and at one side of the fan body in the second direction, the fan body being fixed to the cavity wall of the heat dissipation cavity through the fixing block; The piezoelectric mechanism is located on a side of the fan body away from the fixing block in the second direction.

5. The heat dissipation structure according to claim 3, wherein: The cavity wall of the heat dissipation cavity includes a top wall and a bottom wall spaced apart in the second direction; The bottom wall includes a first inclined surface, the first inclined surface is located between the air inlet and the air outlet, the first inclined surface is configured to extend along the first direction and be inclined toward one side of the second direction, and the distance between the top wall and the first inclined surface in the second direction is configured to increase linearly from the air inlet to the air outlet; One end of the fan body is fixed to an end of the first inclined surface close to the air inlet.

6. The heat dissipation structure according to claim 2, wherein: The cavity wall of the heat dissipation cavity includes a top wall and a bottom wall spaced apart in the second direction; The fan body is configured to be fixed on the top wall, and when powered on, the fan body is configured to swing toward a side close to the bottom wall; Alternatively, the fan body is configured to be fixed on the bottom wall, and in a power-on state, the fan body is configured to swing toward a side close to the top wall.

7. The heat dissipation structure according to claim 2, wherein: The fan body is configured to be plate-shaped, and the thickness of the fan body is configured to be greater than 100 microns; The piezoelectric mechanism is configured to be in a plate shape, and the thickness of the piezoelectric mechanism is configured to be greater than 100 micrometers.

8. The heat dissipation structure according to claim 2, wherein: The fan body swings in the second direction with an amplitude greater than 20 micrometers.

9. The heat dissipation structure according to claim 2, wherein: An extension length of the piezoelectric fan in the first direction is set to be no greater than 20 mm.

10. The heat dissipation structure according to claim 2, wherein: In a power-on state, the oscillation frequency of the fan body is set to a first-order resonance frequency or a multi-order resonance frequency.

11. The heat dissipation structure according to claim 2, wherein: The fan body is made of metal or ceramic. The piezoelectric mechanism is bonded to the fan body and is configured to be glued or directly sintered on the fan body.

12. The heat dissipation structure according to claim 2, wherein: The wind guide mechanism includes a plurality of wind guide plates, the wind guide plates are arranged to extend along the first direction, and the plurality of wind guide plates are spaced apart in a third direction, the third direction being perpendicular to the first direction and the second direction; An air duct extending along the first direction is formed between adjacent air guide plates.

13. The heat dissipation structure according to claim 12, wherein: The width of the air duct in the third direction is configured to linearly narrow from an end close to the piezoelectric fan to an end close to the air outlet.

14. The heat dissipation structure according to claim 12, wherein: The air duct includes a middle portion, and the middle portion is located at the center of the air duct in the first direction; The width of the air duct in the third direction is configured to be linearly narrowed from one end close to the piezoelectric fan to the middle portion; And / or, the width of the air duct in the third direction is configured to be linearly narrowed from one end close to the air outlet toward the middle portion.

15. The heat dissipation structure according to claim 2, further comprising a base and an upper cover, wherein the base is provided with an opening, the upper cover is configured to cover the opening, and the base and the upper cover enclose the heat dissipation cavity; The air inlet is arranged at one end of the base or the upper cover in the first direction, and the air outlet is arranged at the other end of the base in the second direction.

16. The heat dissipation structure according to claim 2, wherein: There are a plurality of piezoelectric fans, and the plurality of piezoelectric fans are arranged at intervals in a third direction, and the third direction is perpendicular to the first direction and the second direction.

17. An electronic device, wherein: It comprises a heat dissipation structure according to any one of claims 1 to 16, as well as a heating device, a heat conducting mechanism and a radiator, wherein the two ends of the heat conducting mechanism are respectively connected to the heating device and the radiator, and the air outlet of the heat dissipation structure is arranged corresponding to the radiator.

18. A heat dissipation system, wherein: comprising a control module, a detection module and a heat dissipation structure according to any one of claims 1 to 16, wherein the control module is electrically connected to the detection module and the heat dissipation structure respectively; The detection module is configured to obtain detection data, wherein the detection data at least includes the air output of the heat dissipation structure and the temperature of the heating device; The control module is configured to control the oscillation frequency of the piezoelectric fan.

19. A control method, applied to the heat dissipation system according to claim 18, wherein: include: The control module controls the piezoelectric fan to turn on and swing at a first preset frequency; When the detection module detects that a first preset condition is met, the control module controls the piezoelectric fan to swing at a second preset frequency. The first preset condition includes the temperature of the heating device and the air output of the heat dissipation structure.

20. The control method according to claim 19, wherein: The heat dissipation structure includes a plurality of piezoelectric fans, and the control method further includes: After the control module controls the piezoelectric fans to swing at a second preset frequency, the detection module detects that the temperature of the heating element reaches a preset temperature, and the control module controls to turn off a preset number of piezoelectric fans.

Images