Piezoelectric Vibration Device

Abstract

To provide a piezoelectric vibration device.SOLUTION: A piezoelectric vibration device includes a rigid structure having a first surface and a second surface opposed to the first surface, and a piezoelectric ceramic body adhered to the second surface of the rigid structure by an adhesive. The piezoelectric ceramic body is provided with at least one hole. By adjusting a shape or size of the hole, an amplitude of the first surface is increased, and an area of the hole of the piezoelectric ceramic body is 50% or less of total area of an area of a bonding surface between the piezoelectric ceramic body and the rigid structure and an area of the hole.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a piezoelectric vibration device, and more particularly to a piezoelectric vibration device in which a piezoelectric ceramic body has a hole, the piezoelectric ceramic body having at least one hole, and by adjusting the shape or size of the hole, the amplitude of the piezoelectric vibration device formed by the piezoelectric ceramic body and the rigid structure is improved. [Background technology]

[0002] Since piezoelectric materials have the special properties of positive and inverse piezoelectric effects, they can realize the mutual conversion of electrical energy and mechanical energy. If a DC electric field in the same direction as the polarization direction is applied to both ends of a piezoelectric body after polarization, the polarization strength increases and the distance between the positive and negative charges increases, so that the piezoelectric body can be stretched along the polarization direction, and the deformation amount of the material also changes according to the magnitude of the electric field. Conversely, if a DC electric field opposite to the polarization direction is applied, the piezoelectric body can be contracted along the polarization direction. In addition, when an AC electric field is applied, the deformation direction of the piezoelectric body changes with the change in the polarity of the AC electric field. Therefore, this effect is to convert electrical energy into mechanical energy. Take the inverse piezoelectric effect as an example, it can convert an electronic signal input to a piezoelectric material into a mechanical displacement of the piezoelectric material or generate ultrasonic waves. Such properties can be applied to various products that need to generate high-power or low-power vibration, displacement, output, and atomization, such as sensors, actuators, oscillators, vibration dampers, sprayers, ultrasonic cleaners, etc.

[0003] In the above applications, the resonant frequency of the piezoelectric material must be matched with the vibration frequency of the structure to be vibrated, so that the optimal vibration effect can be achieved. In this regard, since different structures' shapes and sizes may have different application frequencies, how to provide a simple method for matching the piezoelectric material with the resonant structure is something that those skilled in the art need to continue to research and develop. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a new piezoelectric vibration device, characterized in that the piezoelectric ceramic body has holes, which allows the resonant frequency of the piezoelectric ceramic body to match the vibration frequency of a resonant rigid structure, thereby increasing the amplitude and vibration efficiency of the device. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a piezoelectric vibration device, which includes a rigid structure having a first surface and a second surface opposite to the first surface, and a piezoelectric ceramic body bonded to the second surface of the rigid structure by an adhesive, wherein the piezoelectric ceramic body has at least one hole, and the amplitude of the first surface is improved by adjusting the shape or size of the hole, and the area of ​​the hole in the piezoelectric ceramic body is 50% or less of the total area of ​​the bonding surface between the piezoelectric ceramic body and the rigid structure and the area of ​​the hole.

[0006] According to another aspect of the present invention, there is provided a piezoelectric vibration device having holes, the holes in the piezoelectric ceramic body being circular, triangular, rectangular or polygonal.

[0007] According to another aspect of the invention, a piezoelectric vibration device is provided having a rigid structure, the rigid structure being cylindrical, prismatic, pyramidal or of other shape.

[0008] According to another aspect of the present invention, there is provided a piezoelectric vibration device having a rigid structure, the rigid structure being a horn structure, and the first surface being in the shape of a plane, an inclined surface, a spherical surface, or the like.

[0009] According to another aspect of the present invention, there is provided a piezoelectric vibration device having a piezoelectric ceramic body, the piezoelectric ceramic body being constructed by stacking a plurality of piezoelectric ceramic sheets, at least one of which has a hole.

[0010] In order to make the above-mentioned features and advantages of the present invention more apparent, the present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view of a piezoelectric vibration device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of a rigid structure according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a side view of a piezoelectric ceramic body according to an embodiment of the present invention. [Figure 4] FIG. 2 is a curve diagram of vibration frequency versus z-axis amplitude in a piezoelectric vibration device having no holes in a piezoelectric ceramic body according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a curve diagram of vibration frequency versus z-axis amplitude in a piezoelectric vibration device having a hole in a piezoelectric ceramic body according to an embodiment of the present invention. [Figure 6] FIG. 11 is a perspective view of a piezoelectric vibration device according to another embodiment of the present invention. [Figure 7] FIG. 13 is a perspective view of a piezoelectric vibration device according to another embodiment of the present invention. [Figure 8] FIG. 13 is a perspective view of a piezoelectric vibration device according to another embodiment of the present invention. [Figure 9] FIG. 13 is a perspective view of a piezoelectric vibration device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that such embodiments are merely examples and do not limit the present invention.

[0013] First, refer to FIG. 1, which is a perspective view of a piezoelectric vibration device 100 according to an embodiment of the present invention. The piezoelectric vibration device 100 according to the present invention is generally composed of a rigid structure 101 and a piezoelectric ceramic body 103, of which, also referring to FIG. 2, the rigid structure 101 may be a cylindrical body, which has a first surface 101a and a second surface 101b facing each other across the body of the rigid structure 101. In addition, in an embodiment of the present invention, the piezoelectric ceramic body 103 may be disk-shaped and bonded to the second surface 101b of the rigid structure 101 by an adhesive 105. In which, the piezoelectric ceramic body 103 has a hole 107, and the outer surface exposed from the piezoelectric ceramic body 103 extends to an inner surface in contact with the rigid structure 101.

[0014] In other embodiments, the rigid structure 101 may be a prism, such as, but not limited to, a rectangular prism, a pentagonal prism, or a hexagonal prism. The shape of the piezoelectric ceramic body 103 generally corresponds to the shape of the second surface 101b of the rigid structure 101, and may be, but not limited to, a square or a polygon. The vibration frequency of the rigid structure 101 varies according to its different shape and size. The shape of the hole 107 may be, but not limited to, a circle, a triangle, a square, or a polygon. In the present invention, the hole 107 can be adjusted to make the first surface of the piezoelectric vibration device formed by the piezoelectric ceramic body 103 and the rigid structure 101 reach the maximum amplitude. Details of this part will be described in the following embodiments.

[0015] 1 and 2 again, the rigid structure 101 may be a horn structure, and the piezoelectric ceramic body 103 may further include a positive electrode 113a and a negative electrode 113b, which are respectively located on opposite sides of the piezoelectric ceramic sheet 103, and may be connected to an external power source, for example, an AC power source, by a conductor.

[0016] In actual operation, the AC current flowing through the piezoelectric ceramic body 103 constantly causes mechanical deformation such as expansion and contraction in the piezoelectric ceramic body 103 due to the inverse piezoelectric effect, thus making the piezoelectric ceramic body 103 generate high-frequency vibration in the z-axis direction, thereby causing the rigid structure 101 to generate vibration in the z-axis direction. Such vibration can have many effects together with other external devices connected thereto, such as vibrating liquid in contact with the piezoelectric vibration device 100 to wash items, vibrating and atomizing liquid to generate mist, generating vibration to precisely control the displacement of items, generating corresponding vibration for damping, generating vibration for material provision and material selection, etc.

[0017] In terms of material, the material of the rigid structure 101 can be metal, engineering plastic or ceramic, for example, metal materials such as aluminum, titanium, stainless steel, etc., or ceramic materials such as silicon carbide, silicon nitride, aluminum oxide, etc. The material of the piezoelectric ceramic body 103 can be a lead-containing piezoelectric material such as Pb(ZrTi)O3, PbTiO3, etc., or a lead-free piezoelectric material such as BaTiO3, (NaK)NbO3, etc. In another embodiment, as shown in FIG. 3, the piezoelectric ceramic body 103 can be composed of a plurality of stacked piezoelectric ceramic sheets 103a, at least one of which requires a hole. The design of the laminated multi-layered laminated sheets 103a can reduce the driving voltage required for the piezoelectric ceramic body 10.

[0018] Next, reference is made to Figures 4 and 5, which are curve diagrams of the amplitude (meters) in the z-axis direction of the vibration frequency (Hertz) in the cases where the piezoelectric ceramic body 103 of the aforementioned piezoelectric vibration device 100 does not have the hole 107 and has the hole 107 (hole diameter is 2.5 mm), respectively. As can be seen from Figure 4, when the piezoelectric ceramic body 103 does not have the hole 107, the displacement (i.e., amplitude) of the piezoelectric vibration device 100 has a vibration frequency of 1.8x10 5 Hertz and 2.35x10 5Displacement peaks occur in bands of 14 x 10 Hertz, each of which is approximately -7 meters and 20x10 -7 5, when the piezoelectric ceramic body 103 has a central hole 107, the displacement of the piezoelectric vibration device 100 has a vibration frequency of 1.8x10 5 Approximately 80x10 in the Hertz band -7 A displacement peak of 2.35x10 meters occurs, and the original vibration frequency is 2.35x10 5 The displacement peak close to the Hertz band is slightly shifted to 15x10 -7 meters. Comparing these two figures, the feature that the piezoelectric ceramic body 103 has the holes 107 can increase the maximum amplitude of the original piezoelectric vibration device 100 by more than four times, because the presence of the holes 107 allows the resonance frequency of the piezoelectric ceramic body 103 to match the vibration frequency of the rigid structure 101, so that the entire piezoelectric vibration device 100 can reach the optimum vibration. As can be seen, the presence of the holes 107 in the piezoelectric ceramic body 103 can significantly increase the amplitude of the piezoelectric vibration device 100 in the z-axis direction.

[0019] In addition to the characteristics of whether holes exist, the following Tables 1 and 2 show that the size of the hole diameter d of the hole 107 (i.e., the area of ​​the hole) amplifies the axial vibration of the piezoelectric vibration device 100. The piezoelectric vibration device 100 used is the same as that in the above-mentioned embodiment, the applied frequency is set to 180 thousand Hz, and the driving voltage is set to 50 Vpp. As shown in Table 1, if the hole diameter d of the dug hole 107 is 2 mm or more, the amplitude of the device can be significantly increased, and the optimum value is reached when the hole diameter is 4 mm, and the amplification is about 21 times. According to Table 1, the amplification effect is the best when the ratio of the "area of ​​the hole 107 of the piezoelectric ceramic body 103" to the "total area of ​​the bonding surface between the piezoelectric ceramic body 103 and the rigid structure 101 and the area of ​​the hole 107" is 16%. In other experiments, similar amplification results can be obtained for the ratio of the side length of the hole 107 in the piezoelectric ceramic body 103 (ie, the area of ​​the hole) to the side length of the piezoelectric ceramic body 103 itself.

[0020] [Table 1]

[0021] [Table 2] Now, refer to FIG. 6, which is a perspective view of a piezoelectric vibration device 200 in another embodiment of the present invention. The piezoelectric vibration device 200 in this embodiment is mostly the same as the piezoelectric vibration device 100 in the previous embodiment, and the difference is that the piezoelectric ceramic body 203 of the piezoelectric vibration device 200 has a plurality of holes 207, for example, four holes 207, such as a first hole, a second hole, a third hole, and a fourth hole as shown in the figure. These holes 207 extend to an inner plane where the outer plane exposed from the piezoelectric ceramic body 203 contacts the rigid structure 201. The shape of the holes 207 may be, but is not limited to, a circle, a triangle, a square, or a polygon. The piezoelectric ceramic body 203 may be composed of a plurality of piezoelectric ceramic sheets 103a stacked together, as shown in FIG. 3. As in the above-mentioned mechanism, the existence of the plurality of holes 207 can also make the resonance frequency of the piezoelectric ceramic body 203 match the vibration frequency of the rigid structure 201, thereby increasing the amplitude of the piezoelectric vibration device 200. The details of this part will be explained in the following examples.

[0022] Tables 3 and 4 below show that the number of holes 207 amplifies the vibration in the z-axis direction of the piezoelectric vibration device 200, and the hole diameters are set to 1 mm and 2 mm, the applied frequency is 180 kHz, and the driving voltage is 50 Vpp. As shown in these tables, the design of multiple holes has the same amplification effect. However, the effect is not as significant as the single hole design in the previous embodiment. In this embodiment, the amplification effect is best when the ratio of "the area of ​​the holes 207 of the piezoelectric ceramic body 203" to "the total area of ​​the bonding surface area of ​​the piezoelectric ceramic body 203 and the rigid structure 201 and the area of ​​the holes 207" is 36.13%. In other experiments, similar amplification results can be obtained for the ratio of the side length of the holes 207 of the piezoelectric ceramic body 203 to the side length of the piezoelectric ceramic body 203.

[0023] [Table 3]

[0024] [Table 4] Reference is now made to Figure 7, which is a perspective view of a piezoelectric vibration device 300 according to another embodiment of the present invention. The piezoelectric vibration device 300 of this embodiment is mostly the same as the piezoelectric vibration device 100 of the first embodiment, except that the rigid structure 301 of the piezoelectric vibration device 300 is not a cylinder but a rectangular prism with a side length of about 10 mm, and the piezoelectric ceramic body 303 is in the form of a square sheet.

[0025] Table 5 below shows whether the holes in the piezoelectric ceramic body 303 have an effect of amplifying the amplitude of the square piezoelectric vibration device 300. As can be seen from Table 5, when the rigid structure 301 of the piezoelectric vibration device 300 is a rectangular column, the holes in the piezoelectric ceramic body 303 also have a significant amplifying effect. Among them, under the condition that the hole diameter of the hole 307 in the piezoelectric ceramic body 303 is 2.5 mm, the displacement amplification in the z-axis direction can reach 1793.33%. On the other hand, under the condition that the hole diameter is 4 mm, the displacement in the z-axis direction is significantly reduced, which indicates that the resonant frequency of the piezoelectric ceramic body 303 is not sufficiently matched with the vibration frequency of the rigid structure 301 in the case of the hole 307 with this hole diameter. Also, as can be seen, the applied frequency of the device in this embodiment is between about 160kHz and 170kHz, which is slightly different from the previous 180kHz, because the shape of the entire piezoelectric vibration device 300 is changed from a cylindrical shape to a rectangular column shape.

[0026] [Table 5] Now, please refer to Fig. 8, which is a perspective view of a piezoelectric vibration device 400 according to another embodiment of the present invention. The piezoelectric vibration device 400 of this embodiment is mostly the same as the piezoelectric vibration device 100 of the first embodiment, but the difference is that the diameter of its rigid structure 401 and piezoelectric ceramic body 403 is smaller, for example, from 10 mm in the first embodiment to 5 mm, so that the overall size of the piezoelectric vibration device 400 is smaller and the aspect ratio is larger.

[0027] The following Table 6 shows how changing the aspect ratio of the piezoelectric vibration device 400 affects the effect of the amplitude. As can be seen from Table 6, in addition to changing the applied frequency and the inherent amplitude by changing the shape and size, the holes 407 of the piezoelectric ceramic body 403 can also bring about obvious amplification effect when the body size is small, and the hole diameters of 1.25mm and 2mm can all reach about 21 times the displacement amplification.

[0028] [Table 6] Finally, reference is made to Figure 9, which is a perspective view of a piezoelectric vibration device 500 according to another embodiment of the present invention. The piezoelectric vibration device 500 of this embodiment is mostly the same as the piezoelectric vibration device 100 of the first embodiment, but the difference is that the diameter of its rigid structure 501 and piezoelectric ceramic body 503 is larger, for example, from 10 mm in the first embodiment to 20 mm, thus making the overall size of the piezoelectric vibration device 500 larger and the aspect ratio smaller.

[0029] Table 7 below shows how the aspect ratio of the piezoelectric vibration device 500 affects the effect of the amplitude. As can be seen from Table 7, in addition to the change in the application frequency and the inherent amplitude due to the change in the shape and size, the hole 507 can also bring about obvious amplification effect when the body size is small, whereby when the hole diameter of the hole 507 of the piezoelectric ceramic body 503 is 2.5mm, the amplification of the z-axis amplitude can reach 261.14%. On the other hand, under the condition that the hole diameter is 4mm, the displacement of the z-axis is significantly reduced, which indicates that the resonant frequency of the piezoelectric ceramic body 503 when the hole diameter of the hole 507 of the piezoelectric ceramic body 503 is 4mm is not sufficiently consistent with the vibration frequency of the rigid structure 501.

[0030] [Table 7] According to the above-mentioned embodiments and the related experimental results, the present invention now provides a new piezoelectric vibration device, the feature of which is that the piezoelectric ceramic body has at least one hole, and by adjusting the shape or size of the hole, the amplitude of the piezoelectric vibration device formed by the piezoelectric ceramic body and the given rigid structure can be greatly improved.

[0031] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and any modifications to the present invention fall within the technical scope of the present invention as long as they do not depart from the spirit of the present invention. [Explanation of symbols]

[0032] 100 Piezoelectric vibration device 101 Rigid structure 101a First surface 101b Second surface 103 Piezoelectric ceramic body 103a Piezoelectric ceramic sheet 105 Adhesive 107 holes 113a Positive electrode 113b negative electrode 200 Piezoelectric Vibration Device 201 Rigid structure 201a First surface 203 Piezoelectric ceramic body 207 holes 300 Piezoelectric Vibration Device 301 Rigid structure 303 Piezoelectric ceramic body 307 holes 400 Piezoelectric Vibration Device 401 Rigid structure 403 Piezoelectric ceramic body 407 holes 500 Piezoelectric Vibration Device 501 Rigid structure 503 Piezoelectric ceramic body 507 holes d Pore diameter D diameter

Claims

1. 1. A method of manufacturing a piezoelectric vibration device, comprising the steps of: providing a rigid structure having a first surface and a second surface opposed to the first surface; and adhering a piezoelectric ceramic body to the second surface of the rigid structure with an adhesive; the first surface is opposite to the second surface in a Z-axis direction; The piezoelectric ceramic body has at least one hole, The direction of the central axis of the hole is the same as the Z-axis direction, Increasing the Z-axis amplitude of the first surface by adjusting the shape or size of the hole; When the piezoelectric ceramic body has only one hole, the ratio of "the area of ​​the hole in the piezoelectric ceramic body" to "the total area of ​​the area of ​​the bonding surface between the piezoelectric ceramic body and the rigid structure and the area of ​​the hole" is 4% to 33.64%, When the piezoelectric ceramic body has a plurality of holes, the ratio of "the area of ​​the holes in the piezoelectric ceramic body" to "the total area of ​​the area of ​​the bonding surface between the piezoelectric ceramic body and the rigid structure and the area of ​​the holes" is 0.5% to 36.13%; the piezoelectric ceramic body is formed by laminating a plurality of piezoelectric ceramic sheets; The method of manufacturing a piezoelectric vibration device, wherein at least one of the plurality of piezoelectric ceramic sheets has the hole therein.

2. A method for manufacturing the piezoelectric vibration device according to claim 1, comprising the steps of: The method for manufacturing a piezoelectric vibration device, wherein the rigid structure is a cylinder, a prism or a pyramid.

3. A method for manufacturing the piezoelectric vibration device according to claim 1, comprising the steps of: The method for manufacturing a piezoelectric vibration device, wherein the holes in the piezoelectric ceramic body are circular, triangular, square or polygonal.

4. A method for manufacturing the piezoelectric vibration device according to claim 1, comprising the steps of: the rigid structure is a horn structure; A method for manufacturing a piezoelectric vibration device, wherein the first surface has a shape of a plane, an inclined surface, or a spherical surface.

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