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 device, heat dissipation system and control method TECHNICAL FIELD

[0001] The present disclosure relates to, but is not limited to, the technical field of heat dissipation, and in particular to a heat dissipation structure, an electronic device, a heat dissipation system and a control method. BACKGROUND

[0002] With the gradual improvement of the performance of electronic products, the power consumption of electronic products is also gradually increasing, and the heat dissipation problem is also gradually increasing. Most of the energy consumption of electronic products is ultimately dissipated in the form of heat. At present, the existing electronic products are mostly dissipated by improving the convective heat transfer efficiency, that is, by adding a fan to realize heat dissipation. However, the commonly used axial fan occupies a large space and has a large noise, and is not suitable in many cases, such as mobile phones and televisions, which have limited space. These devices have heat dissipation problems.

[0003] SUMMARY

[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 heat dissipation structure provided by the embodiments of the present disclosure comprises a heat dissipation cavity, a piezoelectric fan and a wind 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 a cavity wall of the heat dissipation cavity and close to the air inlet, and the other end extends to the air outlet.

[0008] The wind guide mechanism is located between the piezoelectric fan and the air outlet, and is arranged to guide the airflow to the air outlet.

[0009] The piezoelectric fan comprises a power-on state and a power-off state. In the power-on state, the end of the piezoelectric fan close to the air outlet swings to generate airflow to the wind guide mechanism.

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

[0011] The piezoelectric fan comprises a fan body and a piezoelectric mechanism, the fan body extends in 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, and the second direction is perpendicular to the first direction.

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

[0014] In some example 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 on one side of the fan body in the second direction, the fan body being fixed on the cavity wall of the heat dissipation cavity through the fixing block.

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

[0016] In some example embodiments, the cavity wall of the heat dissipation cavity comprises a top wall and a bottom wall arranged in the second direction;

[0017] The bottom wall comprises a first inclined surface, the first inclined surface being located between the air inlet and the air outlet, the first inclined surface being arranged to extend in the first direction and tilt towards the side of the second direction, the spacing of the top wall and the first inclined surface in the second direction being arranged to linearly increase from the air inlet to the air outlet;

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

[0019] In some example embodiments, the cavity wall of the heat dissipation cavity comprises a top wall and a bottom wall arranged in the second direction;

[0020] The fan body is arranged to be fixed on the top wall, and in the energized state, the fan body is arranged to swing towards the side close to the bottom wall.

[0021] Alternatively, the fan body is arranged to be fixed on the bottom wall, and in the energized state, the fan body is arranged to swing towards the side close to the top wall.

[0022] In some example embodiments, the fan body is arranged in a plate shape, and the thickness of the fan body is arranged to be greater than 100 microns.

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

[0024] In some example embodiments, the swing amplitude of the fan body in the second direction is greater than 20 microns.

[0025] In some example embodiments, the extension length of the piezoelectric fan in the first direction is arranged to be not greater than 20 millimeters.

[0026] In some example embodiments, the oscillation frequency of the fan body in the powered state is set to a first order resonance frequency or a multi-order resonance frequency.

[0027] In some example embodiments, the material of the fan body comprises metal or ceramic, the piezoelectric mechanism is attached to the fan body, and the piezoelectric mechanism is set to be glued or directly sintered on the fan body.

[0028] In some example embodiments, the air guide mechanism comprises a plurality of air guide plates, the air guide plates are set to extend in the first direction, and the plurality of air guide plates are arranged in a third direction, which is perpendicular to the first direction and the second direction.

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

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

[0031] In some example embodiments, the air duct comprises a middle part, which 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 set to be linearly narrowed from the end close to the piezoelectric fan to the middle part.

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

[0034] In some example embodiments, a base and an upper cover are further included, the base is provided with an open end, the upper cover is set to cover the open end, 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 example embodiments, a plurality of piezoelectric fans are provided, and the plurality of piezoelectric fans are arranged in a third direction, which is perpendicular to the first direction and the second direction.

[0037] The electronic device provided by the embodiments of the present disclosure comprises the heat dissipation structure, the heat generating device, the heat conduction mechanism, and the heat sink, the heat conduction mechanism is connected to the heat generating device and the heat sink at two ends, and the air outlet of the heat dissipation structure is arranged corresponding to the heat sink.

[0038] The embodiment of the present disclosure provides a heat dissipation system, wherein the heat dissipation system comprises a control module, a detection module and the heat dissipation structure mentioned above, the control module is electrically connected with the detection module and the heat dissipation structure respectively.

[0039] The detection module is arranged to obtain detection data, and the detection data at least comprises an air volume of the heat dissipation structure and a temperature of the heating device.

[0040] The control module is arranged to control a swing frequency of the piezoelectric fan.

[0041] The embodiment of the present disclosure provides a control method applied to the heat dissipation system mentioned above, wherein the control method comprises the following steps.

[0042] The control module controls the piezoelectric fan to be turned on and swing at a first preset frequency.

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

[0044] In some example embodiments, the heat dissipation structure comprises a plurality of piezoelectric fans, and the control method further comprises the following steps.

[0045] After the control module controls the piezoelectric fan to swing at the second preset frequency, when the detection module detects that the temperature of the heating device reaches a preset temperature, the control module controls a preset number of piezoelectric fans to be turned off.

[0046] Other aspects can become apparent from a review of the drawings and detailed description.

[0047] SUMMARY

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

[0049] Fig. 1 is a first schematic view of a heat dissipation structure in the example embodiment;

[0050] Fig. 2 is a partial cross-sectional view of the heat dissipation structure in Fig. 1;

[0051] Fig. 3 is a cross-sectional schematic view of a heat dissipation structure in the example embodiment;

[0052] Fig. 4 is a second schematic view of a heat dissipation structure in the example embodiment;

[0053] Fig. 5 is a disassembled schematic view of the heat dissipation structure in Fig. 1;

[0054] Fig. 6 is a schematic diagram of a piezoelectric fan installation in the present exemplary embodiment;

[0055] Fig. 7 is a schematic diagram of a power-off state of the piezoelectric fan of Fig. 6;

[0056] Fig. 8 is a schematic diagram of a first power-on state of the piezoelectric fan of Fig. 6;

[0057] Fig. 9 is a schematic diagram of a second power-on state of the piezoelectric fan of Fig. 6;

[0058] Fig. 10 is a schematic diagram of a first-order resonance mode of a piezoelectric fan in the present exemplary embodiment;

[0059] Fig. 11 is a schematic diagram of a second-order resonance mode of another piezoelectric fan in the present exemplary embodiment;

[0060] Fig. 12 is a schematic diagram of a third-order resonance mode of another piezoelectric fan in the present exemplary embodiment;

[0061] Fig. 13 is a schematic diagram of a partial view of a heat dissipation structure in the present exemplary embodiment;

[0062] Fig. 14 is a schematic diagram of a partial view of another heat dissipation structure in the present exemplary embodiment;

[0063] Fig. 15 is a schematic diagram of a partial view of another heat dissipation structure in the present exemplary embodiment;

[0064] Fig. 16 is a schematic diagram of another heat dissipation structure in the present exemplary embodiment;

[0065] Fig. 17 is a schematic diagram of another heat dissipation structure in the present exemplary embodiment;

[0066] Fig. 18 is a schematic diagram of another heat dissipation structure in the present exemplary embodiment;

[0067] Fig. 19 is a schematic diagram of an electronic device in the present exemplary embodiment;

[0068] Fig. 20 is a schematic diagram of a heat dissipation system in the present exemplary embodiment;

[0069] Fig. 21 is a schematic diagram of a control method in the present exemplary embodiment.

[0070] Explanation of Reference Signs:

[0071] 1 - upper cover; 2 - base; 3 - heat dissipation cavity;

[0072] 4 - piezoelectric fan; 5 - air guide mechanism; 6 - bottom 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 deflector; 15 - air duct;

[0076] 16 - fan body; 17 - piezoelectric mechanism; 18 - fixed 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 - heat generating device;

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

[0081] 31 - detection module; 32 - power module.

[0082] Detailed description

[0083] To make the objectives, technical solutions and advantages of the present disclosure clearer, below the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the embodiments can be implemented in a variety of different forms. One skilled in the art can easily understand that the means and content can be changed into various forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the content described in the following embodiments. The embodiments in the present disclosure and the features in the embodiments can be combined with each other as long as there is no conflict.

[0084] The proportions of the drawings in the present disclosure can be used as a reference in the actual process, but are not limited thereto. For example, the width-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 also not limited to the number shown in the drawings. The drawings described in the present disclosure are only schematic diagrams, and one embodiment of the present disclosure is not limited to the shapes or values shown in the drawings.

[0085] In the present specification, ordinal terms, such as "first", "second", and "third", are used to avoid confusion among constituent elements and are not intended to constitute limitation in terms of numbers.

[0086] In the present specification, words of apositional relationship or positional relationship such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are used to describe the positional relationship of the constituent elements with reference to the drawings for the convenience of the present specification and simplification of the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting on the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the direction in which each constituent element is described. Therefore, it is not limited to the words described in the specification, and can be appropriately changed according to the situation.

[0087] In the present specification, unless explicitly specified and limited otherwise, the terms "mount", "connected", and "linked" are to be interpreted broadly. For example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection via an intermediate element, or communication inside two elements. The specific meaning of the above terms in the present disclosure can be understood by those skilled in the art according to the specific circumstances.

[0088] In the present specification, "electrically connected" includes the case where the constituent elements are connected together through an element having some electrical effect. The element having some electrical effect is not particularly limited as long as it can perform the transmission and reception of electrical signals between the connected constituent elements. Examples of the element having some electrical effect include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, other elements having various functions, and the like.

[0089] In the present specification, "parallel" means a state in which the angle formed by two straight lines is -10° or more and 10° or less, and thus also includes a state in which the angle is -5° or more and 5° or less. In addition, "perpendicular" means a state in which the angle formed by two straight lines is 80° or more and 100° or less, and thus also includes a state in which the angle is 85° or more and 95° or less.

[0090] In the present specification, "film" and "layer" can be interchanged. For example, "conductive layer" can be changed to "conductive film". Similarly, "insulating film" can be changed to "insulating layer".

[0091] The triangle, rectangle, trapezoid, pentagon or hexagon in the specification is not strictly, which can be approximate triangle, rectangle, trapezoid, pentagon or hexagon, and there can be some small deformation caused by tolerance, corner, arc edge and deformation.

[0092] The "about" in the embodiments of the present disclosure refers to not strictly limited boundaries, allowing values within the process and measurement error range.

[0093] At present, the energy consumption of electronic equipment is mainly in the form of heat dissipation, and the related electronic equipment is mainly based on natural convection heat exchange. However, the heat exchange efficiency of natural convection heat exchange is very low, and the heat that can be taken away is very limited. In the case of constant heat dissipation area, more heat can only be transferred by improving the heat exchange coefficient and the temperature difference. Improving the temperature difference will seriously affect the service life of electronic consumer goods, so the air cooling scheme of improving the heat exchange coefficient becomes the main solution to convective heat dissipation. The applicant found that the additional fan can realize the discharge of heat, however, the size of the conventional axial fan product is too large, in the thickness direction, the minimum is also 5 millimeters, for many ultra-thin electronic products, it is impossible to provide such a large thickness size for the installation of the fan; the conventional axial fan is also loud, the existence of rotating parts makes it produce a large noise when running at high load, which will affect the quiet environment or involve sound information. Therefore, the current mainstream fan is not suitable for small space devices such as mobile phones and televisions, and mobile phones and televisions cannot be cooled by adding conventional fans, and poor heat dissipation has become a major problem for such devices. Poor heat dissipation will directly affect the operation of the device, and even cause damage to the device, which will also directly affect the user experience.

[0094] Fig. 1 is a first schematic view of a heat dissipation structure in the present exemplary embodiment, Fig. 2 is a partial sectional view of the heat dissipation structure in Fig. 1, and Fig. 3 is a sectional schematic view of a heat dissipation structure in the present exemplary embodiment. The present exemplary embodiment provides a heat dissipation structure, as shown in Figs. 1 to 3, which can include a heat dissipation cavity 3, and a piezoelectric fan 4 and a wind guide mechanism 5 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 can be arranged on the cavity wall of the heat dissipation cavity 3 and close to the air inlet 10, and the other end of the piezoelectric fan 4 extends to the air outlet 11. The wind guide mechanism 5 can be located between the piezoelectric fan 4 and the air outlet 11, and the wind guide mechanism 5 can guide the airflow to the air outlet 11. The piezoelectric fan 4 can include a power-on state and a power-off state, and in the power-on state, the end of the piezoelectric fan 4 close to the air outlet 11 can swing, thereby generating airflow flowing to the wind guide mechanism 5. Thus, the heat dissipation structure of the present example can utilize the resonance of the piezoelectric fan 4 to increase the air flow rate and improve the heat dissipation effect, and the piezoelectric fan 4 occupies a small space and has excellent noise control, which is suitable for small space devices such as mobile phones, televisions and notebooks.

[0095] Fig. 4 is a second schematic view of a heat dissipation structure in the present exemplary embodiment, Fig. 5 is a schematic view of the heat dissipation structure in Fig. 1 being split, and Fig. 6 is a schematic view of the installation of a piezoelectric fan in the present exemplary embodiment. In some exemplary embodiments, as shown in Figs. 1 to 6, the heat dissipation structure can include a base 2 and an upper cover 1. The base 2 can be recessed, and an opening 9 can be formed on the base 2. The upper cover 1 can be flat, and the outer contour of the upper cover 1 can be consistent with the size of the opening 9. The upper cover 1 can be installed at the opening 9 correspondingly, thereby covering the opening 9. Thus, the base 2 and the upper cover 1 enclose a heat dissipation cavity 3. The base 2 can include a bottom plate 6, a first side plate 7, and a second side plate 8. The bottom plate 6 can be perpendicular to a second direction, and the bottom plate 6 can be rectangular. The first side plate 7 and the second side plate 8 can be located at both ends of the bottom plate 6 in a third direction and at the same side of the bottom plate 6 in the second direction. The first side plate 7 and the second side plate 8 can both be perpendicular to the bottom plate 6, and the first side plate 7 and the second side plate 8 can both extend along a first direction. The side of the first side plate 7 and the second side plate 8 away from the bottom plate 6 forms the opening 9. 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 is provided with a first opening 12 and a second opening 13 at both ends in the first direction, respectively, to communicate the heat dissipation cavity 3 with the outside. The first opening 12 constitutes an air inlet 10, and the second opening 13 constitutes an air outlet 11. The air inlet 10 and the air outlet 11 are located at both ends of the heat dissipation cavity 3 in the first direction, respectively. The end face of the bottom plate 6 facing the upper cover 1 constitutes a bottom wall 20 of the heat dissipation cavity 3, and the end face of the upper cover 1 facing the bottom plate 6 constitutes a top wall 19 of the heat dissipation cavity 3. The bottom wall 20 and the top wall 19 are both 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. In addition, the heat dissipation cavity 3 can be divided into a first cavity 21 and a second cavity 22. The first cavity 21 and the second cavity 22 are arranged in sequence in the first direction. A wind guide mechanism 5 can be located in the second cavity 22, and a piezoelectric fan 4 can be located in the first cavity 21.

[0096] Figure 7 is a schematic diagram of the piezoelectric fan in the power-off state of Figure 6. In some exemplary embodiments, as shown in Figures 2, 3, 6, and 7, 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 cavity wall of the heat dissipation cavity 3, while the other end is suspended, forming a cantilever structure. The material of the fan body 16 includes metal or ceramic. In this example, the material of the fan body 16 may be aluminum, stainless steel, or other metals, or alumina, or ceramic materials. The fan body 16 can undergo certain deformations and can recover its original shape on its own. 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 to this. The shape of the fan body 16 can be adjusted according to the shape of the heat dissipation cavity 3. For example, the fan body 16 may be umbrella-shaped, trapezoidal, circular, or triangular. The thickness of the fan body 16 can be the minimum dimension of the fan body 16 in the second direction, i.e., L2, where the value of L2 is greater than 100 micrometers; 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 millimeters. In this example, the dimension of the fan body 16 in the first direction is L1, where L1 = 8mm, but it is not limited to this. For example, L1 can be 10mm, 12mm or 6mm.

[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 near the air inlet 10 and on the side of the fan body 16 near 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 by the fixing block 18, so that the end of the fan body 16 away from the fixing block 18 is suspended in the air. The fan body 16 has a certain deformation recovery capability, 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, and its thickness (L3) is set to be greater than 100 micrometers. 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 the side of the fan body 16 away from the fixing block 18 in the second direction. The area of ​​the piezoelectric mechanism 17 is smaller than the area of ​​the fan body 16, that is, the orthographic projection of the piezoelectric mechanism 17 on the bottom wall 20 is completely within the orthographic projection range of the fan body 16 on the bottom wall 20. The piezoelectric mechanism 17 may be rectangular, and it fully covers the end face of the fan body 16 away from the fixing block 18 in the third direction. The piezoelectric mechanism 17 is attached to the fan body 16, and can be connected to the fan body 16 by adhesive bonding or direct sintering. The piezoelectric mechanism 17 may include two piezoelectric plates (not shown) and an intermediate layer (not shown) located between the two piezoelectric plates (not shown). The two piezoelectric plates (not shown) and the intermediate layer (not shown) can be electrically connected to the power module. The piezoelectric plates (not shown) may be made of piezoelectric material, which is a type of material with special functions that can convert energy between mechanical stress and voltage. When the power module applies voltage to the two piezoelectric plates (not shown), the piezoelectric plates (not shown) will generate mechanical stress and deform, which is called the inverse piezoelectric effect. When the two piezoelectric plates (not shown) deform due to the inverse piezoelectric effect, the piezoelectric mechanism 17 can pull the fan body 16 to make the same deformation. Since one end of the fan body 16 is fixed by the fixing block 18, the free end of the fan body 16 will move, thereby forming the piezoelectric mechanism 17 driving the fan body 16 to swing. In addition, the power module (not shown) can drive the fan body 16 to perform specific actions. The power supply voltage, voltage conversion speed, and other data of the power module (not shown) can directly affect the operating state of the fan body 16.

[0099] Figure 8 is a first schematic diagram of the energized state of the piezoelectric fan in Figure 6; Figure 9 is a second schematic diagram of the energized state of the piezoelectric fan in Figure 6; Figure 10 is a schematic diagram of the first-order resonance mode of a piezoelectric fan according to this exemplary embodiment; Figure 11 is a schematic diagram of the second-order resonance mode of another piezoelectric fan according to this exemplary embodiment; and Figure 12 is a schematic diagram of the third-order resonance mode of yet another exemplary embodiment. In some exemplary embodiments, as shown in Figures 3, 8, and 9, the power-off state can be the state of the piezoelectric fan when the power module (not shown) stops supplying voltage to the piezoelectric mechanism 17, and the energized state can 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 the fan body 16 remains perpendicular to the second direction according to the material hardness. In the energized 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, and the fan body 16 can swing in the second direction. The oscillation speed of the fan body 16 can be changed by adjusting the voltage conversion speed of the power module (not shown in the figure). For example, the faster the voltage conversion speed, the faster the oscillation speed of the fan body 16. The oscillation amplitude of the fan body 16 can be controlled by controlling the supply voltage of the power module (not shown in the figure). For example, the higher the supply voltage of the power module (not shown in the figure), the larger the oscillation amplitude of the fan body 16. To achieve the best fan effect, it is necessary to select a piezoelectric mechanism 17 and a fan body 16 of appropriate size to reach the optimal resonant frequency point of the piezoelectric material, so that the piezoelectric fan works in its best state. In this example, the oscillation amplitude of the fan body 16 in the second direction is L4, where L4 is greater than 20 micrometers. Combined with the fact that the size of the fan body 16 in the first direction is less than 20 millimeters, the piezoelectric fan has the highest possible first-order resonant frequency.

[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 near 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. The second position S2 is the extreme position of the fan body 16 swinging near 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. 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 of 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. The oscillation frequency of the fan body 16 can be the first-order resonant frequency, as shown in Figure 10. The oscillation of the fan body 16 is a bidirectional reciprocating oscillation, but it is not limited to this. For example, the oscillation frequency of the fan body 16 can be the second-order resonant frequency, as shown in Figure 11. The oscillation of the fan body 16 has two different modes. Or, for example, the oscillation frequency of the fan body 16 can be the third-order resonant frequency, as shown in Figure 12. The oscillation of the fan body 16 has three different 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 provided on the base 2, but the air inlet 10 can be provided 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] Figure 14 is a partial schematic diagram of another heat dissipation structure of this exemplary embodiment. Based on the ideal gas law, the applicant determines that the pressure and volume changes within the partially enclosed space formed by the piezoelectric fan 4 and the heat dissipation cavity 3 during oscillation satisfy the following formula:

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

[0104] Taking the Taylor expansion of the right side of Equation 1, we get Equation 2:

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

[0106] It is known that increasing the sweeping area of ​​the piezoelectric fan 4 (i.e., increasing the oscillation 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, if the airflow in the first space 23 is poor or stagnant, it can be considered 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. The first inclined surface 24 is located between the air inlet 10 and the air outlet 11. The first inclined surface 24 may be configured to extend along a first direction and tilt to one side towards a 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 along the first defense line, so that the bottom wall 20 forms a sloping 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 position of the fan body 16 swinging 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 will not accumulate a lot of stagnant air below when it is 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 the air is locally compressed by the piezoelectric fan 4 to form high-pressure gas, which is blown out from the air outlet 11.

[0107] Figure 15 is a partial schematic diagram of another heat dissipation structure according to this exemplary embodiment. In some exemplary embodiments, as shown in Figure 15, the cavity wall of the heat dissipation cavity 3 may include a top wall 19 and a bottom wall 20 spaced apart in a second direction. One end of the piezoelectric fan 4 near the air inlet 10 is fixed to the bottom wall 20. The piezoelectric fan 4 extends along a first direction and is attached to the bottom wall 20. In the power-off state, the piezoelectric fan 4 remains stationary at the second position S2. In the power-on state, the piezoelectric fan 4 can swing towards 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 position of the piezoelectric fan 4 swinging towards the side near the top wall 19. When the piezoelectric fan 4 is in the first position S1, the distance between the piezoelectric fan 4 and the top wall 19 is the closest. The second position S2 is the same as the position of the piezoelectric fan 4 in the power-off state. Therefore, the oscillation of the piezoelectric fan 4 in the energized state is relative to that in the de-energized state, oscillating only to one side in the second direction, i.e., using a unidirectional oscillation method. This prevents the piezoelectric fan 4 from oscillating to the other side, ensuring sufficient air compression and simplifying the design while reducing manufacturing costs. However, it is not limited to this. For example, one end of the piezoelectric fan 4 near the air inlet 10 may be fixed to the top wall 19, with the piezoelectric fan 4 extending along the first direction and attached to the top wall 19. In the de-energized state, the piezoelectric fan 4 remains stationary, while in the energized state, the piezoelectric fan 4 is set to oscillate towards the side closer to the bottom wall 20, also using a unidirectional oscillation method.

[0108] In some exemplary embodiments, as shown in FIG6, the air guiding mechanism 5 may include a plurality of air guiding plates 14. The air guiding plates 14 may be flat, and all of the plurality of air guiding plates 14 may extend along a first direction. The plurality of air guiding plates 14 may be arranged at intervals in a third direction, such that the plurality of air guiding plates 14 are parallel to each other, and an air duct 15 is formed between adjacent air guiding plates 14. The air duct 15 may extend along the first direction, and the plurality of air ducts 15 may be arranged at intervals in a third direction. As shown by the dashed arrow, 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 guiding mechanism 5 may assist in forming local air compression in the heat dissipation cavity 3, increasing the pressure and velocity of the air outlet 11, so that the air is locally compressed by the piezoelectric fan 4 to form high-pressure gas.

[0109] Figure 16 is a schematic diagram of another heat dissipation structure in this example embodiment. In some exemplary embodiments, as shown in Figure 16, the air duct 15 extends along a first direction, and multiple air ducts 15 are arranged at intervals along a third direction. The width of the air duct 15 in the third direction is L5. L5 narrows linearly from the end near the piezoelectric fan 4 to the end near the air outlet 11 in the first direction, making the air duct 15 funnel-shaped. The size of the air guide plate 14 in the third direction widens linearly from the end near the piezoelectric fan 4 to the end near the air outlet 11, making the air duct 15 between two adjacent air guide plates funnel-shaped. As shown in Figure 8, since the vibration of the piezoelectric fan 4 is reciprocating, a certain negative pressure is generated when it swings upward to the first position S1. The negative pressure drives the surrounding gas to replenish the air. By adopting the asymmetrical air duct 15 structure shown in Figure 15, the amount of gas replenished from the air outlet 11 can be minimized to a certain extent, thereby increasing the net air output per unit time.

[0110] Figure 17 is a schematic diagram of another heat dissipation structure in this example embodiment. In some exemplary embodiments, as shown in Figure 17, the air duct 15 extends along a first direction, and multiple air ducts 15 are arranged at intervals along a third direction. The air duct 15 includes a middle portion 25, which is located at the center of the air duct 15 in the first direction. The width of the air duct 15 in the third direction is L5. The value of L5 in the first direction narrows linearly from the end of the air duct 15 near the piezoelectric fan 4 towards the middle portion 25, and the value of L5 in the first direction also narrows linearly from the end of the air duct 15 near the air outlet 11 towards the middle portion 25. Thus, the air duct 15 adopts a Laval tube structure. The air duct 15 narrows from the end near the piezoelectric fan 4 towards the middle portion 25 in the first direction, which accelerates the airflow. The air duct 15 widens from the middle portion 25 towards the end near the air outlet 11 in the first direction, forming an expansion that reduces the pressure on the airflow and helps to form a higher speed jet. The air guide plate 14 has a dimension of L6 in the third direction. L6 is linearly widened from the end near the piezoelectric fan 4 toward the middle part 25 in the first direction, and then linearly narrowed from the middle part 25 toward the end near the air outlet 11. Thus, the air duct 15 of the Laval tube structure is formed between two adjacent air guide plates 14.

[0111] In some exemplary embodiments, as shown in FIG6, the piezoelectric fan 4 can form a high-frequency resonance with a resonant frequency greater than 15kHz and an oscillation amplitude greater than 20 micrometers. Combined with the heat dissipation cavity 3 with the air guiding mechanism 5, local rapid air compression can be achieved to form a jet.

[0112] Figure 18 is a schematic diagram of another heat dissipation structure in this example embodiment. In some exemplary embodiments, as shown in Figure 18, multiple piezoelectric fans 4 may be provided, and the multiple piezoelectric fans 4 may be arranged at intervals in a third direction. In this example, the number of piezoelectric fans 4 is three, but it is not limited to this. For example, the number of piezoelectric fans 4 may be two, four, or six, and is not limited to three. In addition, the oscillation amplitude and oscillation frequency of the multiple piezoelectric fans 4 are the same, but it is not limited to this. For example, the oscillation amplitude of the multiple piezoelectric fans 4 may be different, or the oscillation frequency of the multiple piezoelectric fans 4 may be different, or the oscillation amplitude and oscillation frequency of the multiple piezoelectric fans 4 may be different. Thus, the multiple piezoelectric fans 4 form a discrete structure, and the wind speed is controlled by controlling the number of piezoelectric fans 4 that are activated, so as to reasonably regulate the heat dissipation requirements and power consumption.

[0113] Figure 19 is a schematic diagram of an electronic device according to this example embodiment. In some exemplary embodiments, as shown in Figure 19, the electronic device may include a heat dissipation structure 26, a heat-generating device 27, a heat-conducting mechanism 28, and a heat sink 29. The two ends of the heat-conducting mechanism 28 can be connected to the heat-generating device 27 and the heat sink 29, respectively. The air outlet 11 of the heat dissipation structure 26 can be correspondingly provided to the heat sink 29, so that the airflow from the heat dissipation structure 26 can directly blow onto the heat sink 29. The electronic device can be a mobile phone, tablet computer, television, monitor, laptop computer, navigator, or other products or components; this embodiment is not limited to these. In this example, the electronic device can be a laptop computer, the heat-generating device 27 can be a CPU, the heat-conducting mechanism 28 can be a flat heat pipe, and the heat sink 29 can be a finned heat sink. The flat heat pipe (heat-conducting mechanism 28) integrates a finned heat sink (heat sink 29) and a heat dissipation structure 26 at its end. The heat dissipation structure 26, applied to the laptop computer, uses the flat heat pipe (heat-conducting mechanism 28) to conduct heat from the CPU (heat-generating device 27) to a location near the laptop's casing. The heat dissipation structure 26 can also blow air across the finned heat sink (heat sink 29) to remove heat from the laptop. Compared to traditional axial fan solutions, the heat dissipation structure 26 in this example occupies less space, allowing for a reduction in the thickness of the electronic device. For example, under natural convection cooling conditions, at a room temperature of 20℃, a 14-inch laptop can rely on single-sided heat exchange with an operating power of 20W, resulting in a surface temperature of 65.3℃. However, the same laptop using this cooling structure 26 can achieve a convection heat transfer coefficient of 22W / m2 / K, reducing the laptop surface temperature to 34.7℃, demonstrating a significant cooling effect.

[0114] Figure 20 is a schematic diagram of a heat dissipation system according to this exemplary embodiment. As shown in Figure 20, the heat dissipation system may include a control module 30, a detection module 31, and a heat dissipation structure with a piezoelectric fan 4. The control module 30 can be electrically connected to both the detection module 31 and the heat dissipation structure. The detection module 31 can acquire detection data and send it to the control module 30. The detection data includes at least the airflow of the heat dissipation structure 26 and the temperature of the heat-generating device. The heat dissipation structure may have a power module 32, through which the piezoelectric fan 4 is powered. The power module 32 provides voltage to the piezoelectric fan 4. The power module 32 can be electrically connected to the control module 30, allowing the control module 30 to control the operation of the power module 32 based on the detection data, thereby controlling the oscillation frequency of the piezoelectric fan 4.

[0115] Figure 21 is a schematic diagram of a control method according to this exemplary embodiment. The exemplary embodiment provides a control method applicable to the heat dissipation system shown in Figure 20. As shown in Figure 21, the control method may include: first, controlling the piezoelectric fan 4 to turn on and oscillate at a first preset frequency via 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 has been met, the control module 30 controls the piezoelectric fan 4 to oscillate at a second preset frequency. The first preset condition may include the temperature of the heat-generating device and the airflow of the heat dissipation structure. Thus, the detection module 31 detects whether the piezoelectric fan 4 has reached the optimal resonance state and feeds it back to the control module 30. The control module 30 controls the piezoelectric fan 4 and makes small adjustments to its resonance frequency until the optimal resonance state under this condition is reached, thereby reducing power consumption.

[0116] In some exemplary embodiments, the heat dissipation structure may include multiple piezoelectric fans 4 as shown in FIG17. As shown in FIG21, the control method may include, after the control module 30 controls the piezoelectric fans 4 to oscillate at a second preset frequency, when the detection module 31 detects that the temperature of the heat-generating device has reached 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 heat-generating device has reached 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 heat-generating devices such as the CPU and the user-set operating mode (high performance / energy saving / silent, etc.) determine whether to turn on or how many piezoelectric fans 4 are turned on. The control method of this example maintains real-time temperature detection, and once the required temperature value is reached, it balances the number of piezoelectric fans 4 turned on to reduce power consumption as much as possible while meeting the temperature requirements.

[0117] In conjunction with the above embodiments, the piezoelectric fan 4 in the heat dissipation structure can generate high-frequency resonance, with a resonant frequency greater than 15kHz and an oscillation amplitude greater than 20 micrometers. Combined with the structure of the heat dissipation cavity 3, it can achieve rapid local air compression, forming a jet. Through the optimization of the piezoelectric fan 4 and its materials, high-frequency resonance is achieved. Through the airflow design, a high-speed flow field can be realized, achieving efficient heat dissipation.

[0118] While the embodiments disclosed herein are as described above, the content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art to which this disclosure pertains may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A heat dissipating structure, wherein, The heat dissipation cavity, a piezoelectric fan and a wind guide mechanism are arranged 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 to the air outlet; The wind guide mechanism is arranged between the piezoelectric fan and the air outlet, and is arranged to guide the airflow to the air outlet; The piezoelectric fan has 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 airflow to the wind 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 a first direction; The piezoelectric fan includes a fan body and a piezoelectric mechanism, the fan body extends in 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, and the second direction 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 on the cavity wall of the heat dissipation cavity, and the other end is suspended 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 is located at one end of the fan body close to the air inlet and on one side of the fan body in the second direction, and the fan body is fixed on the cavity wall of the heat dissipation cavity through the fixing block; The piezoelectric mechanism is located on the 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 arranged 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 arranged to extend in the first direction and tilt to one side in the second direction, and the spacing between the top wall and the first inclined surface in the second direction is arranged to linearly increase from the air inlet to the air outlet; One end of the fan body is fixed on one 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 arranged in the second direction; The fan body is arranged to be fixed on the top wall, and in the power-on state, the fan body is arranged to swing to the side close to the bottom wall; Alternatively, the fan body is arranged to be fixed on the bottom wall, and in the power-on state, the fan body is arranged to swing to the side close to the top wall.

7. The heat dissipating structure according to claim 2, wherein The fan body is arranged in a plate shape, and the thickness of the fan body is greater than 100 microns; The piezoelectric mechanism is arranged in a plate shape, and the thickness of the piezoelectric mechanism is greater than 100 microns.

8. The heat dissipation structure according to claim 2, wherein The swing amplitude of the fan body in the second direction is greater than 20 microns.

9. The heat dissipating structure according to claim 2, wherein, The extension length of the piezoelectric fan in the first direction is not greater than 20 mm.

10. The heat dissipating structure according to claim 2, wherein, In the power-on state, the swing frequency of the fan body is arranged as a first-order resonance frequency or a multi-order resonance frequency.

11. The heat dissipation structure according to claim 2, wherein, The material of the fan body includes metal or ceramic, the piezoelectric mechanism and the fan body are attached, and the piezoelectric mechanism is arranged to be glued or directly sintered on the fan body.

12. The heat dissipating structure according to claim 2, wherein, The air guide mechanism comprises a plurality of air guide plates arranged to extend in the first direction, and the air guide plates are arranged in a third direction perpendicular to the first direction and the second direction. An air duct extending in 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 arranged to be linearly narrowed from the end close to the piezoelectric fan to the end close to the air outlet.

14. The heat dissipation structure according to claim 12, wherein, The air duct comprises a middle part located in the center of the air duct in the first direction. The width of the air duct in the third direction is arranged to be linearly narrowed from the end close to the piezoelectric fan to the middle part. And / or, the width of the air duct in the third direction is arranged to be linearly narrowed from the end close to the air outlet to the middle part.

15. The heat dissipation structure according to claim 2, further comprising a base and an upper cover, the base being provided with an open end, and the upper cover being arranged to cover the open end, the base and the upper cover enclosing 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 dissipating structure according to claim 2, wherein, The piezoelectric fan is provided in a plurality of piezoelectric fans arranged in a third direction perpendicular to the first direction and the second direction.

17. An electronic device, comprising: The heat dissipation structure according to any one of claims 1 to 16, a heat generating device, a heat conducting mechanism and a heat sink, the heat conducting mechanism being connected to the heat generating device and the heat sink at both ends, and the air outlet of the heat dissipation structure being arranged corresponding to the heat sink.

18. A heat dissipation system, wherein, The heat dissipation structure according to any one of claims 1 to 16, a control module and a detection module, the control module being electrically connected to the detection module and the heat dissipation structure. The detection module is arranged to obtain detection data, and the detection data at least includes the air outlet of the heat dissipation structure and the temperature of the heat generating device. The control module is arranged to control the oscillation frequency of the piezoelectric fan.

19. A control method applied to the heat dissipation system according to claim 18, wherein, The control module controls the piezoelectric fan to start and oscillate at a first preset frequency. When the detection module detects that a first preset condition is reached, the control module controls the piezoelectric fan to oscillate at a second preset frequency, and the first preset condition includes the temperature of the heat generating device and the air outlet of the heat dissipation structure. The heat dissipation structure comprises a plurality of piezoelectric fans, and the control method further comprises:

20. The control method according to claim 19, wherein After the control module controls the piezoelectric fan to oscillate at a second preset frequency, the detection module detects that the temperature of the heat generating device reaches a preset temperature, and the control module controls to close a preset number of piezoelectric fans. ​

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