Piezoelectric vibration plate and piezoelectric sound generating component

Abstract

The piezoelectric vibration plate (11) comprises a conductive base (100) having a central portion (110) and a peripheral portion (120) located around the central portion (110), and a piezoelectric body (150) arranged at the central portion (110). When a voltage is applied to the piezoelectric body (150), the central portion (110) performs bending vibration and reciprocates on both sides of the thickness direction of the base (100). The base (100) is provided with at least one through portion (130) located between the central portion (110) and the peripheral portion (120), and at least one connecting portion (140) connecting the central portion (110) and the peripheral portion (120). The at least one connecting portion (140) is arranged at a position farthest from the center of the central portion (110) of the base (100) where the displacement during bending vibration is the largest.

Description

Technical Field

[0001] The present invention relates to a piezoelectric vibration plate and a piezoelectric sound producing component. Background Art

[0002] Piezoelectric sound generating components are widely used as piezoelectric buzzers or piezoelectric receivers for generating alarm sounds and operating sounds in electronic devices, home appliances, mobile phones, etc. Such piezoelectric sound generating components are required to have good acoustic conversion efficiency.

[0003] For example, Patent Document 1 discloses a piezoelectric vibration plate as follows: a vibration plate is formed by electrically and mechanically joining a rectangular piezoelectric plate to a metal plate face to face, a slit is provided to surround an area where the metal plate joins the piezoelectric plate, four connecting portions connecting the portion surrounded by the slit with a portion outside the slit are provided at positions equidistant from both ends in the length direction of the portion surrounded by the slit, and the connecting portions are provided at positions approximately 1 / 6 of the length from both ends in the length direction of the portion surrounded by the slit.

[0004] In addition, Patent Document 2 discloses a piezoelectric speaker comprising a piezoelectric body, a metal vibration plate having a vibration plate portion which is mounted on a frame and constitutes a piezoelectric vibrator together with the piezoelectric body, and an elastic supporting portion which elastically supports the vibration plate portion, wherein a damping material is loaded between the vibration plate portion of the metal vibration plate and the frame, and the piezoelectric speaker is constructed so that the damping material is formed by a portion of a polymer film adhered to the metal vibration plate.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 11-355892

[0006] Patent Document 2: Japanese Patent Application Publication No. 2006-287968

[0007] However, in the piezoelectric diaphragm of Patent Document 1, the connection portion is provided at a position relatively close to the vibration center, and the diaphragm may not be sufficiently displaced, and good acoustic conversion efficiency may not be obtained. In addition, in the piezoelectric speaker of Patent Document 2, the frequency characteristics are flattened and the deformation component is reduced by providing a damping material filled in a plurality of slit-shaped holes located at the outer edge of the diaphragm portion and the flexure arm portion, but according to the configuration of Patent Document 2, the bending vibration of the diaphragm portion may be absorbed by the damping material. As a result, the displacement of the diaphragm portion may be reduced, and the acoustic conversion efficiency may deteriorate. Summary of the invention

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a piezoelectric diaphragm and a piezoelectric sound generating component that can obtain good acoustic conversion efficiency.

[0009] A piezoelectric vibration plate on one side of the present invention comprises a conductive base having a central portion and a peripheral portion located around the central portion, and a piezoelectric body portion arranged at the central portion. When a voltage is applied to the piezoelectric body portion, the central portion performs bending vibration and reciprocates on both sides of the thickness direction of the base. The base portion is provided with at least one through portion located between the central portion and the peripheral portion, and at least one connecting portion connecting the central portion and the peripheral portion. The at least one connecting portion is arranged at a position farthest from the center of the central portion of the base where the displacement during bending vibration is the largest.

[0010] According to the present invention, a piezoelectric diaphragm and a piezoelectric sound generating component capable of obtaining good acoustic conversion efficiency can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an overall view of the piezoelectric sound generating component according to the first embodiment.

[0012] Figure 2 It is an exploded perspective view of the piezoelectric sound generating component according to the first embodiment.

[0013] Figure 3 It is a diagram for explaining the structure of the piezoelectric vibration plate according to the first embodiment.

[0014] Figure 4A yes Figure 2 IVA-IVA line cross-sectional view of the piezoelectric vibration plate.

[0015] Figure 4B It is a schematic diagram of the displacement distribution of the piezoelectric vibration plate according to the first embodiment at the time of maximum displacement.

[0016] Figure 5 It is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric diaphragm according to the first embodiment.

[0017] Figure 6 It is a diagram for explaining the structure of a sealing material in the piezoelectric vibration plate according to the second embodiment.

[0018] Figure 7 It is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric diaphragm according to the second embodiment.

[0019] Fig. 8A This is a diagram for explaining the state of the on-off valve when the central portion of the piezoelectric vibration plate according to the third embodiment is not displaced.

[0020] Figure 8B It is a diagram for explaining the state of the on-off valve when the central portion of the piezoelectric vibration plate according to the third embodiment undergoes a first displacement.

[0021] Figure 8CIt is a diagram for explaining the state of the on-off valve when the central portion of the piezoelectric vibration plate according to the third embodiment undergoes the second displacement.

[0022] Fig. 9 It is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric diaphragm according to the third embodiment.

[0023] Fig. 10A It is a diagram for explaining a modified example of the base portion of the piezoelectric vibration plate.

[0024] Fig. 10B It is a diagram for explaining a modified example of the base portion of the piezoelectric vibration plate.

[0025] Fig. 10C It is a diagram for explaining a modified example of the base portion of the piezoelectric vibration plate.

[0026] Fig.11A It is a diagram for explaining a modified example of the through portion and the connecting portion of the piezoelectric vibration plate.

[0027] Fig. 11B It is a diagram for explaining a modified example of the through portion and the connecting portion of the piezoelectric vibration plate.

[0028] Fig. 11C It is a diagram for explaining a modified example of the through portion and the connecting portion of the piezoelectric vibration plate. DETAILED DESCRIPTION

[0029] The following is an explanation of the embodiments of the present invention. In the following drawings, the same or similar reference numerals are used to represent the same or similar components. The drawings are for illustration only, and the size and shape of each part are schematic and should not be understood as limiting the technical scope of the present invention to the embodiments.

[0030] [First embodiment]

[0031] <Piezoelectric sounding component 1>

[0032] First, refer to Figure 1 as well as Figure 2 , the piezoelectric sound generating component 1 of the first embodiment is described. Here, Figure 1 is an overall view of a piezoelectric sound producing component 1 according to the first embodiment. Figure 2 FIG. 1 is an exploded perspective view of the piezoelectric sound generating component 1 according to the first embodiment. Figure 1 as well as Figure 2 In the drawings, the configuration necessary for explaining at least a part of the characteristics of the structure of the piezoelectric sound generating component 1 is extracted and described, but this does not prevent the piezoelectric sound generating component 1 from having configurations not shown.

[0033] The piezoelectric sound generating component 1 of the first embodiment includes a piezoelectric vibration part 10, a lower case 20 supporting the piezoelectric vibration part 10 from the back side, and an upper case 30 pressing the piezoelectric vibration part 10 from the front side. When the piezoelectric sound generating component 1 is viewed from above along the thickness direction of the piezoelectric sound generating component 1, the piezoelectric vibration part 10, the lower case 20, and the upper case 30 are squares whose outer edges are of the same size. In addition, in the piezoelectric vibration part 10, the lower case 20, and the upper case 30, mounting pins and mounting holes for mounting are provided at respective corners and at positions corresponding to each other.

[0034] In the following description, the configurations of the piezoelectric sound generating component 1 are described with reference to the XYZ axis direction, where the thickness direction of the piezoelectric sound generating component 1 is the "Z axis direction", the direction of one side of the square of the piezoelectric sound generating component 1 is the "X axis direction", and the direction of the other side of the square of the piezoelectric sound generating component 1 is the "Y axis direction". The surface on the positive Z axis side of each configuration is the "front surface", and the surface on the negative Z axis side of each configuration is the "back surface". In addition, unless otherwise specified, "viewed from above" means the case where the configurations are viewed from above along the thickness direction (Z axis direction) of the piezoelectric sound generating component 1 (each configuration). In addition, the shapes of the piezoelectric vibration portion 10, the lower case 20, and the upper case 30 when viewed from above are referred to as the "top view shape" of these configurations. In addition, the state where the piezoelectric vibration portion 10, the lower case 20, and the upper case 30 are assembled to configure the piezoelectric sound generating component 1 is sometimes referred to as the "assembled state".

[0035] The piezoelectric vibration portion 10 is plate-shaped and includes a piezoelectric vibration plate 11, a spacer 12, and a terminal portion 13. The piezoelectric vibration portion 10 is configured so that the piezoelectric vibration plate 11, the spacer 12, and the terminal portion 13 are stacked in this order in the positive direction of the Z axis. In addition, in a plan view, the piezoelectric vibration plate 11, the spacer 12, and the terminal portion 13 are squares whose outer edges are the same size.

[0036] The piezoelectric vibration plate 11 is in the shape of a thin plate. The piezoelectric vibration plate 11 includes a base 100 and a piezoelectric body 150 provided on the central side of the surface of the base 100. In addition, the piezoelectric vibration plate 11 includes two mounting terminals 113 provided side by side along one side of the base 100. The mounting terminal 113 is an example of an input / output terminal, and is electrically connected to a mounting substrate (not shown) to supply input / output signals supplied from the mounting substrate to the piezoelectric body 150 of the piezoelectric vibration plate 11.

[0037] In the piezoelectric vibration plate 11 of the first embodiment, when a voltage is applied to the piezoelectric body 150 in the assembled state, the piezoelectric vibration plate 11 performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. In addition, the details of each structure of the piezoelectric vibration plate 11 will be described later. In addition, in the following description, the description related to the mounting terminal 113 in the piezoelectric vibration plate 11 is omitted, and the piezoelectric vibration plate 11 is described as having only the base 100 and the piezoelectric body 150.

[0038] The spacer 12 is frame-shaped, and the inner peripheral surface of the frame is formed into a square shape larger than the piezoelectric body 150 in a top view. In addition, the spacer 12 is made of an insulating material such as LCP (liquid crystal polymer). The spacer 12 connects the piezoelectric vibration plate 11 and the terminal portion 13 in an insulated manner and adjusts the interval between the piezoelectric vibration plate 11 and the terminal portion 13 in the Z-axis direction.

[0039] The terminal portion 13 is frame-shaped, and the inner peripheral surface of the frame is formed in a square shape larger than the piezoelectric body portion 150 in a top view. For example, the terminal portion 13 is formed by plating iron, brass, etc. with Ni (nickel), Cu (copper), or Au (gold). In addition, the terminal portion 13 has a frame 131, a terminal 132 provided at a corner of the inner edge of the frame 131, and two mounting terminals 133 provided side by side on one side of the frame 131.

[0040] The inner peripheral surface of the frame 131 is formed in a square shape in a plan view that is larger than the piezoelectric body 150. The frame 131 supports the terminal 132 and the mounting terminal 133 and electrically connects the two.

[0041] The terminal 132 is an electrical contact with the piezoelectric vibration plate 11, and extends toward the inside of the frame 131 and toward the piezoelectric body 150 side, that is, toward the positive direction of the X axis and toward the negative direction of the Z axis, so that in the assembled state, it can contact the piezoelectric body 150 of the piezoelectric vibration plate 11. In addition, although the electrical contact is at this one position in the first embodiment, the connection position and the number are not limited.

[0042] The mounting terminal 133 is an example of an input / output terminal, is electrically connected to a mounting substrate (not shown), and supplies an input / output signal supplied from the mounting substrate to the piezoelectric body portion 150 of the piezoelectric vibration plate 11 via the terminal 132 .

[0043] The lower case 20 is an example of a case portion, and is in a box shape with an opening formed on the side in contact with the piezoelectric vibration plate 11 of the piezoelectric vibration portion 10. The lower case 20 is formed of an insulating material such as LCP (liquid crystal polymer). The lower case 20 has a bottom portion 21, a side wall portion 22 formed to protrude from the outer edge of the bottom portion 21, and two vents 25 formed on opposite sides of the bottom portion 21.

[0044] The end surface of the side wall portion 22 on the opening side constitutes a mounting surface 23 that contacts the piezoelectric vibration plate 11 during assembly. In addition, the bottom surface portion 21 and the inner surface of the side wall portion 22 constitute a concave inner surface 24 of the lower housing 20. The vent 25 is a structure for reducing air resistance in the space between the lower housing 20 and the mounting substrate when the piezoelectric sound generating component 1 is mounted on the mounting substrate.

[0045] The upper case 30 is an example of a case portion, and is in a box shape with an opening formed on the side in contact with the terminal portion 13 of the piezoelectric vibrating portion 10. The upper case 30 is formed of an insulating material such as LCP (liquid crystal polymer). The upper case 30 has a top portion 31, a side wall portion 32 formed to protrude from the outer edge of the top portion 31, and a sound emission hole 35 formed on one side of the top portion 31.

[0046] The end surface of the side wall portion 32 on the opening side constitutes a mounting surface 33 that contacts the terminal portion 13 during assembly. In addition, the top surface portion 31 and the inner surface of the side wall portion 32 constitute a concave inner surface 34 of the upper case 30. The sound emission hole 35 is a structure for transmitting the sound generated by the vibration of the piezoelectric vibration plate 11 of the piezoelectric vibration portion 10 to the outside of the lower case 20 and the upper case 30.

[0047] In the piezoelectric sound generating component 1 of the first embodiment, the piezoelectric vibration part 10 is sandwiched and fixed between the lower case 20 and the upper case 30 by being placed so as to cover the opening of the lower case 20 and the opening of the upper case 30 is covered toward the piezoelectric vibration part 10. In addition, in the assembled state, an acoustic space D is formed between the inner surface 24 of the lower case 20 and the piezoelectric vibration plate 11 of the piezoelectric vibration part 10 (see Figure 4A ), an acoustic space U is formed between the inner surface 34 of the upper housing 30 and the piezoelectric vibration plate 11 of the piezoelectric vibration portion 10 (refer to Figure 4A ). In this way, in the piezoelectric sounding component 1, if an AC voltage is applied to the piezoelectric body 150 of the piezoelectric vibration part 10 via the mounting terminals 133 and 113 as input and output terminals, the base 100 (central portion 110 described later) of the piezoelectric vibration part 10 flexurally vibrates in the acoustic space D and the acoustic space U and reciprocates on both sides in the thickness direction of the base 100 to produce sound. In addition, the sound produced is transmitted to the outside of the lower shell 20 and the upper shell 30 via the sound emitting hole 35 and the vent 25.

[0048] <Piezoelectric vibration plate 11>

[0049] Next, refer to Figure 3 The structure of the piezoelectric vibration plate 11 of the first embodiment will be described in more detail. Figure 3 It is a diagram for explaining the structure of the piezoelectric vibration plate 11 according to the first embodiment.

[0050] In order to improve the displacement of the base 100 of such a piezoelectric vibration plate 11, it is considered to add a slit to the base 100. On the other hand, due to the addition of the slit, when the base 100 vibrates, the air on both sides of the thickness direction of the base 100 convects through the slit. Due to the convection of the air, the piezoelectric vibration plate 11 cannot make a sound. In addition, in order to solve the problem of air convection caused by the slit, it is considered to seal the slit. However, there is a possibility that the vibration of the base 100 is hindered by the sealing material, the structure of the base 100 is complicated, and there is a possibility that good acoustic conversion efficiency cannot be obtained.

[0051] On the other hand, the piezoelectric sound generating member 1 or the piezoelectric diaphragm 11 according to the first embodiment can obtain good acoustic conversion efficiency by using the base 100 having a simple structure as described later.

[0052] The piezoelectric diaphragm 11 of the first embodiment includes a base portion 100 and a piezoelectric body portion 150 electrically and mechanically bonded to the base portion 100 at the center of the upper surface of the base portion 100 .

[0053] The base 100 is a thin plate member with a thickness of 0.05 mm and a square shape with each side having a length of 18 mm in a plan view. The base 100 is made of a material having good electrical conductivity and spring elasticity, such as a metal such as 42 alloy with an elastic modulus of 1 GPa or more.

[0054] The base 100 includes a central portion 110, a peripheral portion 120 located around the central portion 110, a through portion 130 located between the central portion 110 and the peripheral portion 120, and a connecting portion 140 connecting the central portion 110 and the peripheral portion 120. The central portion 110, the peripheral portion 120, and the connecting portion 140 are integrally formed. In other words, the central portion 110 and the peripheral portion 120 are partially separated by the through portion 130 provided around the central portion 110.

[0055] The central portion 110 is joined face-to-face with the piezoelectric body 150 to form a portion that performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. In addition, the top view shape of the central portion 110 is formed in a square that is larger than the top view shape of the piezoelectric body 150 and smaller than the top view shapes of the inner surface 24 of the lower shell 20 and the inner surface 34 of the upper shell 30. In this way, the central portion 110 can ensure the area for holding the piezoelectric body 150 and its own vibration area, and can vibrate without colliding with the lower shell 20 and the upper shell 30.

[0056] The peripheral portion 120 is a portion that contacts and is clamped by the lower shell 20 and the upper shell 30 when the lower shell 20 and the upper shell 30 are mounted on the piezoelectric vibration portion 10 by bonding, fitting, riveting, etc. Therefore, the peripheral portion 120 is a portion that hardly vibrates relative to the central portion 110. In addition, the peripheral portion 120 is a frame-shaped member, and the outer edge and the inner edge are both square in top view.

[0057] The through portion 130 is slit-shaped when viewed from above. Figure 3 In the example shown, the slit-shaped through-portion 130 has an isosceles trapezoidal shape when one side in the long-side direction is the base. In the first embodiment, four through-portions 130 are provided between the central portion 110 and the peripheral portion 120. These isosceles trapezoidal through-portions 130 are provided at equal intervals so that their bases are parallel to the four sides of the central portion 110, and the upper base faces the central portion 110 side and the lower base faces the peripheral portion 120 side.

[0058] In addition, Figure 3 In the example shown, in the through-portion 130 of the isosceles trapezoidal shape, the internal angles of the two ends of the lower base are, for example, 45°. Thus, the portion between the two legs of the adjacent through-portion 130, i.e., the connecting portion 140 described later, can connect the corner of the central portion 110 and the internal angle of the peripheral portion 120. In addition, the height of the isosceles trapezoidal shape, i.e., the slit width (width in the short side direction) of the through-portion 130, is, for example, greater than 0 mm and less than 0.1 mm. By adopting the through-portion 130 having such a thin slit width, when the central portion 110 vibrates, the convection of air located on both sides of the thickness direction of the central portion 110 can be suppressed.

[0059] The connecting portion 140 is a structure that electrically connects the central portion 110 and the peripheral portion 120 and supports the central portion 110 separated from the peripheral portion 120 by the through portion 130. In the first embodiment, the connecting portion 140 is a portion between the central portion 110 and the peripheral portion 120 that is not penetrated by the through portion 130. In other words, the connecting portion 140 is a portion that connects two adjacent through portions 130. Therefore, in the first embodiment, four connecting portions 140 are formed. These connecting portions 140 correspond to the arrangement and shape of the four through portions 130, and are formed between the central portion 110 and the peripheral portion 120 to connect the four corners of the central portion 110 and the four inner corners of the peripheral portion 120, respectively. In addition, since the top view shape of the central portion 110 is a square, these connecting portions 140 are arranged at the position farthest from the center of the central portion 110. That is, the connecting portion 140 is arranged at a position where the influence of the vibration of the central portion 110 is the least.

[0060] The piezoelectric body 150 is, for example, a thin plate member with a thickness of about 0.1 mm, and is a square with each side having a length of 13 mm when viewed from above. The piezoelectric body 150 is made of piezoelectric ceramics such as PZT. In addition, NiCu electrodes (not shown) are formed on the surface and back of the piezoelectric body 150, respectively. The back electrode is face-to-face bonded to the central portion 110 and electrically connected.

[0061] <Flexural Vibration of the Piezoelectric Vibration Plate 11 >

[0062] Next, refer to Figure 2 to Figure 5 , the bending vibration of the piezoelectric vibration plate 11 of the first embodiment is described. In addition, in the following description, the relationship between the bending vibration and the structure of the through-portion 130 is described after the overall picture of the bending vibration of the piezoelectric vibration plate 11 and the relationship between the bending vibration and the structure of the connecting portion 140 are described. Here, Figure 4A as well as Figure 4B 1 is a diagram for explaining the displacement of the piezoelectric vibration plate 11 according to the first embodiment. Specifically, Figure 4A yes Figure 2 A cross-sectional view of the piezoelectric vibration plate 11 taken along the line IVA-IVA, Figure 4B is a schematic diagram of the displacement distribution in the case of the maximum displacement of the piezoelectric vibration plate 11. Figure 4B In the example, the vibration intensity of the parts with the same concentration is the same. Figure 5 This is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric diaphragm 11 according to the first embodiment, where the vertical axis represents the sound pressure (dB) and the horizontal axis represents the frequency (kHz).

[0063] <Relationship between flexural vibration and the structure of the connecting portion 140>

[0064] First, the overall picture of the bending vibration of the piezoelectric vibration plate 11 and the relationship between the bending vibration and the structure of the connecting portion 140 are described. Figure 4A As shown by the dotted line, when a voltage is applied to the piezoelectric body 150, the central portion 110 performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. That is, the central portion 110 repeatedly displaces toward the lower case 20 side and toward the upper case 30 side.

[0065] In the following, for convenience of description, the displacement of the central portion 110 of the piezoelectric vibration plate 11 toward the lower case 20 is referred to as “first displacement”, and the displacement of the central portion 110 of the piezoelectric vibration plate 11 toward the upper case 30 is referred to as “second displacement”.

[0066] Generally speaking, vibration spreads in a circular shape from the vibration center toward the periphery, and the farther away from the vibration center, the weaker the vibration. In the piezoelectric vibration plate 11 of the first embodiment, the piezoelectric body 150 is bonded to the central portion of the central portion 110, so the center of the top view of the central portion 110 becomes the vibration center of the central portion 110. Figure 4B As shown in FIG. 1 , when the vibration of the central portion 110 is the strongest, the central portion of the central portion 110 bulges higher (in the case of the second displacement) or sinks lower (in the case of the first displacement) than other portions, that is, the displacement of the central portion is the largest. On the other hand, the vibration of the central portion 110 becomes weaker as it spreads from the center of the central portion 110 toward the peripheral side, and the displacement of the corresponding portion gradually decreases.

[0067] In addition, the planar shape of the central portion 110 of the first embodiment is a square, so the four corners of the central portion 110 are located at the farthest positions from the center (vibration center) of the central portion 110. Figure 4B As shown in FIG. 1 , the corners of the central portion 110 are in a state of almost no vibration like the peripheral portion 120. Furthermore, the connecting portion 140, which is provided at a position farther from the vibration center than the corners of the central portion 110, is less affected by the vibration than the corners of the central portion 110, and thus is in a state of almost no vibration like the corners of the central portion 110 and the peripheral portion 120.

[0068] In this way, by arranging the connecting portion 140 at the position farthest from the center of the central portion 110, even if the central portion of the central portion 110 vibrates with a large displacement, the connecting portion 140 is hardly affected by the vibration, and the occurrence of problems such as fatigue damage such as fracture caused by deformation can be suppressed, and the durability of the piezoelectric vibration plate 11 can be improved. In addition, since the connecting portion 140 hardly vibrates, the strength is sufficient even if a connecting portion 140 with a narrow width is used. By making the connecting portion 140 thinner, the length of the long side direction of the through portion 130 can be sufficiently ensured, and the obstruction to the vibration of the central portion 110 can be further reduced. In this way, the displacement (vibration) of the central portion 110 can be improved, and the piezoelectric vibration plate 11 can obtain a better acoustic conversion efficiency.

[0069] In other words, by arranging the connection portion 140 at the position farthest from the center of the central portion 110 , it is possible to improve the durability of the piezoelectric diaphragm 11 and obtain good acoustic conversion efficiency.

[0070] <Relationship between flexural vibration and the structure of the penetration portion 130 >

[0071] Next, the relationship between the bending vibration of the piezoelectric vibration plate 11 and the structure of the through-portion 130 is described. In the piezoelectric vibration portion 10 (piezoelectric vibration plate 11), air exists in the through-portion 130 located between the central portion 110 and the peripheral portion 120. Under normal temperature and pressure conditions (normal conditions), air is a substance with a relatively low viscosity, and its viscosity μ is approximately 0.018 mPa·s. In addition, when the central portion 110 is not performing bending vibration, the air existing in the through-portion 130 is air with a relatively low viscosity in a normal state. Therefore, such air with a relatively low viscosity simply flows out of the through-portion 130 and flows toward the acoustic space D or the acoustic space U due to changes in the states (for example, pressure, etc.) of the acoustic space D and the acoustic space U.

[0072] On the other hand, when the central portion 110 located on one side of the through-portion 130 is subjected to bending vibration relative to the peripheral portion 120 located on the other side of the through-portion 130 and fixed by the lower shell 20 and the upper shell 30, a shear stress (friction stress) τ is generated in the air existing in the through-portion 130. In addition, in this case, the actual viscosity μ of the air hardly changes, but due to the high friction stress τ, the air is difficult to flow relative to the slit wall surface of the through-portion 130. As a result, it can be considered that the air existing in the through-portion 130 has the same characteristics as a substance with a high viscosity. That is, in this case, the air existing in the through-portion 130 has characteristics similar to those of a substance with a high viscosity.

[0073] Hereinafter, the characteristics of such air existing in the through-portion 130 will be described in detail using the following formula (1). In addition, in the present embodiment, "τ" involved in the following formula (1) refers to friction stress (shear stress), specifically, it refers to the friction stress of the air existing in the through-portion 130 relative to the slit wall surface of the through-portion 130. "F" refers to force, specifically, it refers to the force generated between the air existing in the through-portion 130 and the slit wall surface of the through-portion 130. "S" refers to the cross-sectional area of ​​the through-portion 130. "μ" refers to a proportionality coefficient, which represents the viscosity of the air existing in the through-portion 130. In addition, in the case of air, if it is within the range of the normal state, the value of μ hardly changes. "U" refers to the relative speed, specifically, it refers to the relative speed when the central portion 110 is subjected to bending vibration relative to the peripheral portion 120 fixed by the lower shell 20 and the upper shell 30. "h" refers to the slit width of the through-portion 130.

[0074] τ=F / S=μ*U / h···············(1)

[0075] Moreover, according to formula (1), when the proportional coefficient μ is constant, if the relative speed U of the central portion 110 relative to the peripheral portion 120 and the slit width h of the through portion 130 are relatively large, the friction stress τ is relatively large. In the present embodiment, the relative speed U of the central portion 110 relative to the peripheral portion 120 is a high speed in the range of about 2 kHz to 10 kHz. In addition, the slit width h of the through portion 130 is a relatively small size that is larger than 0 mm and less than 0.1 mm. Therefore, the U / h ratio of the present embodiment becomes a very high value. Therefore, if such a central portion 110 that performs bending vibration and a through portion 130 having a smaller slit width are used, a relatively large friction stress τ can be obtained.

[0076] In this way, when the central portion 110 is subjected to bending vibration at high speed relative to the fixed peripheral portion 120, a large friction stress τ is generated in the air existing in the through portion 130 having a small slit width. Moreover, due to the large friction stress τ, it is difficult for the air to flow relative to the slit wall surface of the through portion 130. In other words, the air existing in the through portion 130 is difficult to flow out of the through portion 130 because it can be regarded as a substance with high viscosity (similar to the characteristics of high viscosity). As a result, the air existing in the through portion 130 can play an effect of hindering the convection of the air existing in the acoustic space U and the acoustic space D located on both sides of the through portion 130. That is, the air located in the acoustic space D hardly flows into the acoustic space U through the through portion 130, and the air located in the acoustic space U hardly flows into the acoustic space D through the through portion 130.

[0077] In addition, if the slit width of the through portion 130 is further described in detail, Figure 5 As shown, in the low frequency domain of 0.55kHz to 0.6kHz, the peak of the sound pressure appears when the slit width of the through portion 130 is set to 0.108mm or less, compared with the case where the slit width is set to 0.400mm. Specifically, if the slit width of the through portion 130 is set to 0.108mm, a high sound pressure of 60.1dB can be obtained. In addition, if the slit width of the through portion 130 is set to 0.040mm or less, a high sound pressure of about 70dB can be obtained. And, if the slit width of the through portion 130 is set to 0.013mm, a high sound pressure of about 75dB can be obtained. In other words, if the slit width of the through portion 130 is set to 0.1mm or less, a high sound pressure higher than 60dB can be obtained in the low frequency domain of 0.55kHz to 0.6kHz, and a good acoustic conversion efficiency can be obtained.

[0078] In contrast, when the slit width of the through portion 130 is set to 0.400 mm, the peak of the sound pressure does not clearly appear in the low frequency range of 0.55 kHz to 0.6 kHz. In addition, the highest sound pressure in this case is about 47 dB, which is about 78% of the case where the slit width of the through portion 130 is 0.108 mm. In other words, when the slit width of the through portion 130 is set to 0.400 mm, a high sound pressure cannot be obtained.

[0079] In this way, by making the slit width of the through-portion 130 less than 0.1 mm, even if the through-portion 130 is not sealed, it is possible to suppress the convection of the air in the acoustic space D and the air in the acoustic space U through the through-portion 130 when the base 100 vibrates. As a result, the range of the separation portion between the central portion 110 and the peripheral portion 120 can be expanded, and the obstruction of the vibration of the central portion 110 by the connection between the central portion 110 and the peripheral portion 120 can be further reduced. In this way, the displacement (vibration) of the central portion 110 can be improved, and the piezoelectric vibration plate 11 can obtain a better acoustic conversion efficiency. In addition, in this case, the structure of the base 100 of the piezoelectric vibration plate 11 is simple, and it is possible to reduce the manufacturing cost and improve the productivity.

[0080] In other words, by setting the slit width of the through-portion 130 to 0.1 mm or less, good acoustic conversion efficiency can be obtained even when the piezoelectric diaphragm 11 having a simple structure is used.

[0081] As described above, by adopting the connecting portion 140 and the through portion 130 of the first embodiment, it is possible to obtain the piezoelectric diaphragm 11 having high durability and good acoustic conversion efficiency even with a simple configuration.

[0082] [Second embodiment]

[0083] Next, refer to Figure 6 as well as Figure 7 The structure of the piezoelectric vibration plate 11 of the second embodiment will be described in detail. Figure 6 1 is a diagram for explaining the structure of a sealing material 200 for sealing the through portion 130 of the piezoelectric vibration plate 11 according to the second embodiment. Figure 7 This is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric diaphragm 11 according to the second embodiment, where the vertical axis represents the sound pressure (dB) and the horizontal axis represents the frequency (kHz).

[0084] The second embodiment is different from the first embodiment in that it focuses on the case where the convection of air is restricted by providing a restriction portion in the through-portion 130, and adopts an embodiment of a sealing material 200 that seals the through-portion 130. In addition, in the second embodiment, the description of the same matters as the first embodiment is omitted, and only the different points, that is, the structure and effects of the sealing material 200 are described. In particular, the same effects brought about by the same structure are not mentioned.

[0085] The through portion 130 of the second embodiment has a sealing material 200. In addition, in the second embodiment, the through portion 130 and the connecting portion 140 may also be different from the through portion 130 and the connecting portion 140 of the first embodiment. Specifically, the width of the through portion 130 of the second embodiment does not need to be less than 0.1 mm as in the first embodiment, and any width can be selected according to actual requirements. Here, the width of the through portion 130 is 0.4 mm. In addition, the connecting portion 140 of the second embodiment does not need to be arranged at the position farthest from the center of the central portion 110 as in the first embodiment, and any arrangement position can be selected according to actual requirements.

[0086] The sealing material 200 is an example of a restricting portion, and is made of an elastic material such as resin that can be elastically deformed. In the second embodiment, the sealing material 200 is embedded in the through-portion 130 to seal the entire through-portion 130 .

[0087] In this way, the through-portion 130 of the base 100 is sealed by the sealing material 200, so that the acoustic space D and the acoustic space U become completely independent spaces. In other words, the through-portion 130, which is the connection path between the air in the acoustic space D and the air in the acoustic space U, is closed by the sealing of the sealing material 200. Therefore, even if the base 100 vibrates, the air in the acoustic space D and the air in the acoustic space U do not convect.

[0088] In addition, the sealing material 200 is a material that can be elastically deformed, and elastically deforms with the displacement caused by the vibration of the central part 110. Therefore, even if the central part 110 and the peripheral part 120 are connected via the sealing material 200, the vibration of the central part 110 is hardly hindered by the sealing material 200. Therefore, the central part 110 can be displaced to a large extent, and good acoustic conversion efficiency can be achieved. In addition, the connecting part 140 is reinforced by the surrounding sealing material 200, so the durability and stability of the piezoelectric vibration plate 11 can be improved.

[0089] And, if Figure 7As shown, when the sealing material 200 is used, the peak of the sound pressure appears in the low frequency range of 0.55kHz to 0.6kHz. In this case, a high sound pressure of about 69dB can be obtained, and a good acoustic conversion efficiency can be obtained.

[0090] As described above, by using the sealing material 200 of the second embodiment, the durability and stability of the piezoelectric diaphragm 11 can be improved, and good acoustic conversion efficiency can be obtained.

[0091] [Third Embodiment]

[0092] Next, referring to FIG. 8 and Fig. 9 The structure of the piezoelectric vibration plate 11 of the third embodiment will be described in detail. Figure 8A to Figure 8C 1 is a diagram for explaining the configuration of the on-off valve 300 provided in the through portion 130 of the piezoelectric vibration plate 11 according to the third embodiment. Specifically, Fig. 8A 1 is a diagram showing the state of the on-off valve 300 when the central portion 110 is not displaced. Figure 8B 1 is a diagram showing the state of the on-off valve 300 when the central portion 110 is subjected to the first displacement. Figure 8C 3 is a diagram showing the state of the on-off valve 300 when the central portion 110 performs the second displacement. Fig. 9 This is a diagram for explaining the sound pressure frequency characteristics of the piezoelectric vibration plate 11 of the third embodiment, with the vertical axis representing the sound pressure (dB) and the horizontal axis representing the frequency (kHz). In addition, in the following description, the description is centered on the situation when the central part 110 performs the first displacement. The situation when the central part 110 performs the second displacement is only opposite to the situation of the first displacement, and the principle is the same, so the description is simplified here.

[0093] The third embodiment is the same as the second embodiment, and focuses on the situation that the convection of air is restricted by providing a restriction portion in the through-hole 130. The third embodiment is different from the second embodiment in that the third embodiment adopts an opening and closing valve 300 instead of the sealing material 200 adopted in the second embodiment. In addition, in the third embodiment, the description of the same matters as the first and second embodiments is omitted, and only the different points, that is, the structure and effect of the opening and closing valve 300 are described. In particular, the same effect brought about by the same structure is not mentioned.

[0094] In the third embodiment, the through portion 130 and the connecting portion 140 may also be different from the through portion 130 and the connecting portion 140 of the first embodiment. Specifically, the width of the through portion 130 of the third embodiment does not need to be less than 0.1 mm as in the first embodiment, and any width can be selected according to actual requirements. Here, the width of the through portion 130 is 0.4 mm. In addition, the connecting portion 140 of the third embodiment does not need to be arranged at the position farthest from the center of the central portion 110 as in the first embodiment, and any configuration position can be selected according to actual requirements. In addition, although the through portion 130 of the third embodiment is configured to have the same width as the through portion 130 of the second embodiment, it can also be configured to have a width different from the through portion 130 of the second embodiment.

[0095] The on-off valve 300 is an example of a restricting portion, and is formed of an elastic material such as a resin film. In addition, the on-off valve 300 includes a first valve 310 and a second valve 320. When the piezoelectric vibration plate 11 is not vibrating, that is, the central portion 110 is not displaced, as shown in FIG. Fig. 8A As shown in the figure, the first valve 310 is provided to cover the first opening 130a on the acoustic space D side of the through portion 130, and the second valve 320 is provided to cover the second opening 130b on the acoustic space U side of the through portion 130. In addition, the first valve 310 and the second valve 320 are configured to open and close the first opening 130a and the second opening 130b of the through portion 130 by the bending vibration of the piezoelectric vibration plate 11.

[0096] When the central portion 110 performs the first displacement, as shown in FIG. Figure 8B As shown, the pressure Pd of the air in the acoustic space D increases, and the pressure Pu of the air in the acoustic space U decreases. Moreover, the first valve 310 is pressed to the back of the base 100 by the increased pressure Pd, thereby covering the first opening 130a of the through-portion 130 on the acoustic space D side. On the other hand, the second valve 320 is in a state of opening the second opening 130b of the through-portion 130 on the acoustic space U side due to the reduction in the pressing force due to the reduced pressure Pu and the traction due to the first displacement of the central portion 110.

[0097] Thus, in the first displacement state of the central portion 110, the first valve 310 closes the first opening 130a of the through-portion 130 on the acoustic space D side, and the second valve 320 opens the second opening 130b of the through-portion 130 on the acoustic space U side. Since the first opening 130a of the through-portion 130 of the base 100 is closed by the first valve 310, the acoustic space D and the acoustic space U become completely independent spaces. In other words, the through-portion 130, which is the connecting path of the air in the acoustic space D and the air in the acoustic space U, is closed by the first valve 310. Therefore, even if the base 100 vibrates, the air in the acoustic space D and the air in the acoustic space U do not convect.

[0098] In addition, when the central portion 110 performs a second displacement, as shown in FIG. Figure 8C As shown, the second valve 320 closes the second opening 130b of the through-portion 130 on the acoustic space U side, and the first valve 310 opens the first opening 130a of the through-portion 130 on the acoustic space D side. Since the second opening 130b of the through-portion 130 of the base 100 is closed by the second valve 320, even if the base 100 vibrates, the air in the acoustic space U and the air in the acoustic space D do not convect.

[0099] And, if Fig. 9 As shown, when the on-off valve 300 is used, the peak of the sound pressure appears in the low frequency range of 0.55kHz to 0.6kHz. In this case, a high sound pressure of about 68dB can be obtained, and a good acoustic conversion efficiency can be obtained.

[0100] In this way, by adopting the on-off valve 300 that can open and close the through-portion 130, the convection of the air in the acoustic space D and the air in the acoustic space U can be reliably suppressed, and by maintaining the separation between the central portion 110 and the peripheral portion 120, the obstruction of the vibration of the central portion 110 caused by the connection between the central portion 110 and the peripheral portion 120 can be further reduced. In this way, the displacement (vibration) of the central portion 110 is improved, and the piezoelectric vibration plate 11 can obtain good acoustic conversion efficiency. In addition, in this case, since the on-off valve 300 is composed of a thin film, the structure of the base 100 of the piezoelectric vibration plate 11 is simple, and it is possible to reduce manufacturing costs and improve productivity.

[0101] As described above, by adopting the on-off valve 300 of the third embodiment, it is possible to obtain the piezoelectric diaphragm 11 having excellent acoustic conversion efficiency even with a simple configuration.

[0102] In the above, exemplary embodiments of the present invention have been described.

[0103] In a piezoelectric vibration plate 11 of an embodiment of the present invention, there is provided a conductive base 100 having a central portion 110 and a peripheral portion 120 located around the central portion 110, and a piezoelectric body portion 150 provided at the central portion 110. When a voltage is applied to the piezoelectric body portion 150, the central portion 110 performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. The base 100 is provided with at least one through portion 130 located between the central portion 110 and the peripheral portion 120, and at least one connecting portion 140 connecting the central portion 110 and the peripheral portion 120. The at least one connecting portion 140 is arranged at a position farthest from the center of the central portion 110 of the base 100 where the displacement during bending vibration is the largest.

[0104] According to the above configuration, it is possible to improve the durability of the piezoelectric diaphragm and obtain good acoustic conversion efficiency.

[0105] Furthermore, in the above configuration, at least one through portion 130 is in the shape of a slit.

[0106] According to the above configuration, the displacement property of the piezoelectric diaphragm is improved, and thus good acoustic conversion efficiency can be obtained.

[0107] In the above-described configuration, the slit width of the slit-shaped through portion 130 is larger than 0 mm and is equal to or smaller than 0.1 mm.

[0108] According to the above configuration, it is possible to improve the durability of the piezoelectric diaphragm and obtain good acoustic conversion efficiency using a simple configuration.

[0109] In addition, in the piezoelectric vibration plate 11 of other embodiments of the present invention, the through portion 130 has a limiting portion, which limits the air located on the first side in the thickness direction of the base 100 from flowing into the second side in the thickness direction through the through portion 130, and the air located on the second side in the thickness direction from flowing into the first side through the through portion 130.

[0110] According to the above configuration, the influence of air convection is reduced, thereby achieving good acoustic conversion efficiency.

[0111] In the above configuration, the restricting portion is the sealing material 200 that seals at least a portion of at least one through portion 130 and is elastically deformed.

[0112] According to the above configuration, the influence of air convection can be reliably reduced using a simple configuration.

[0113] In the above-mentioned configuration, the sealing material 200 is made of resin.

[0114] According to the above configuration, it is possible to reduce the interference with the displacement of the piezoelectric diaphragm.

[0115] In the piezoelectric vibration plate 11 according to another embodiment of the present invention, the restricting portion is an on-off valve 300 capable of opening and closing at least one through portion 130 .

[0116] According to the above configuration, the displacement performance can be improved and the influence of air convection can be reduced reliably.

[0117] In the above configuration, the on-off valve 300 opens and closes at least one through portion 130 by the bending vibration of the piezoelectric vibration plate 11 .

[0118] According to the above configuration, the influence of air convection can be reliably reduced.

[0119] In addition, in the above-mentioned structure, at least one through portion 130 has an opening located on one side in the thickness direction of the base 100, and another opening located on the other side in the thickness direction of the base 100, and the on-off valve 300 has a first valve 310 provided at one opening, and a second valve 320 provided at the other opening, and when the piezoelectric vibration plate 11 performs the second displacement from one side to the other side, the second valve 320 closes the other opening of the through portion 130, and when the piezoelectric vibration plate 11 performs the first displacement from the other side to the one side, the first valve 310 closes the one opening of the through portion 130.

[0120] According to the above configuration, the displacement performance can be improved with a simple configuration, and the influence of air convection can be reliably reduced.

[0121] In any of the above-mentioned piezoelectric vibration plates 11 , the central portion 110 , the peripheral portion 120 , and the connecting portion 140 are one member, the central portion 110 and the base portion 100 are rectangular in plan view, and the connecting portion 140 is provided at a corner of the central portion 110 .

[0122] According to the above configuration, it is possible to improve vibration symmetry, and to achieve improvements in durability and acoustic conversion efficiency.

[0123] In addition, in another embodiment of the piezoelectric vibration plate 11 of the present invention, there is provided a conductive base 100 having a central portion 110 and a peripheral portion 120 located around the central portion 110, and a piezoelectric body portion 150 provided on the central portion 110. When a voltage is applied to the piezoelectric body portion 150, the central portion 110 performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. The base 100 is provided with at least one through portion 130 located between the central portion 110 and the peripheral portion 120, and at least one connecting portion 140 connecting the central portion 110 and the peripheral portion 120. The at least one through portion 130 is in the shape of a slit having a slit width greater than 0 mm and less than 0.1 mm when the base 100 is viewed from above.

[0124] According to the above configuration, the durability and stability of the piezoelectric diaphragm can be improved, and good acoustic conversion efficiency can be obtained.

[0125] In addition, in another embodiment of the piezoelectric vibration plate 11 of the present invention, there is provided a conductive base 100 having a central portion 110 and a peripheral portion 120 located around the central portion 110, and a piezoelectric body portion 150 provided at the central portion 110. When a voltage is applied to the piezoelectric body portion 150, the central portion 110 performs bending vibration and reciprocates on both sides in the thickness direction of the base 100. The base 100 is provided with at least one through portion 130 located between the central portion 110 and the peripheral portion 120, and at least one connecting portion 140 connecting the central portion 110 and the peripheral portion 120. The at least one through portion 130 has a first valve 310 provided at a first opening 130a located at a first side in the thickness direction of the base 100, and a second valve 320 provided at a second opening 130b located at a second side in the thickness direction of the base 100.

[0126] According to the above configuration, a piezoelectric diaphragm having excellent acoustic conversion efficiency can be obtained using a simple configuration.

[0127] In addition, the piezoelectric sound producing component 1 comprises: a piezoelectric vibration portion 10 having any one of the above-mentioned piezoelectric vibration plates 11, and input / output terminals for applying voltage to the piezoelectric vibration plate 11, namely, mounting terminals 133 and mounting terminals 113; and a lower shell 20 and an upper shell 30, constituting a shell portion for holding the piezoelectric vibration portion 10.

[0128] According to the above configuration, it is possible to improve the durability of the piezoelectric sound generating component and obtain good acoustic conversion efficiency.

[0129] [Modifications]

[0130] The present invention is not limited to the above-mentioned embodiment and can be applied in various modifications. Figures 10A to 11C, a modified example of the present invention is described. Here, Figures 10A to 10C 1 is a diagram for explaining a modified example of the base portion 100 of the piezoelectric vibration plate 11. Figures 11A to 11C These are diagrams for explaining modified examples of the through portion 130 and the connecting portion 140 of the piezoelectric vibration plate 11 .

[0131] In the above embodiment, the base portion 100 and the central portion 110 are described as being square. Figures 10A to 10C As shown, the base portion 100 and the central portion 110 may be configured to have various shapes, such as a rectangle, a hexagon (other polygons), or a circle.

[0132] In addition, in the above embodiment, the base 100 is described as having four through-holes 130, but the number of through-holes 130 is not limited to four. Figures 10A to 10C As shown, there may be two, three, or six. In addition, there may be any number other than these, for example, only one. In the case of having a plurality of through portions 130, these through portions 130 may be arranged at equal intervals or at unequal intervals. However, by arranging a plurality of through portions 130 at equal intervals, the symmetry of the vibration distribution can be improved. In addition, in the case of a rectangular base 100 using two through portions 130, it is preferred that the long side directions of these through portions 130 are formed to be parallel to the long side direction of the base 100. With such a configuration, it is possible to reduce the obstruction to the displacement of the central portion 110.

[0133] In addition, in the above-mentioned embodiment, the top view shape of the through portion 130 is described as an isosceles trapezoidal shape, but the shape of the through portion 130 is not limited to the isosceles trapezoidal shape. Fig. 10C , Figures 11A to 11C As shown, it may be an arc shape, a rectangular shape, an irregular shape, or a combination of shapes. In addition, it may be configured so that the connecting portion 140 also has various shapes according to the shape of these through-portions 130. However, when the central portion 110 is a polygon, in order to reduce the influence of the vibration center from the central portion 110, it is preferred that the connecting portion 140 is arranged around the corner of the central portion 110. In addition, in order to improve the symmetry of the vibration distribution, it is preferred to set the connecting portion 140 at equal intervals.

[0134] Here, yes Fig. 11C The through portion 130 shown in the combined shape is briefly described. Fig. 11C The through portion 130 of the example includes a first through portion 1310 and a second through portion 1320. The first through portion 1310 is substantially V-shaped when viewed from above, and the second through portion 1320 is substantially rectangular when viewed from above. Fig. 11CIn the example shown, the four second through-holes 1320 are provided between the central portion 110 and the peripheral portion 120, and the long-side directions are parallel to the four sides of the central portion 110. The four first through-holes 1310 are provided between the central portion 110 and the peripheral portion 120, at the corners of the central portion 110 and outside the second through-holes 1320. In addition, the length of the long-side direction of the first through-holes 1310 is formed to be longer than the distance between adjacent second through-holes 1320 (the width of the connected portion).

[0135] According to the combination of the first through-portion 1310 and the second through-portion 1320, the first through-portion 1310 located outside the corner of the central portion 110 can reduce the obstruction of the vibration of the central portion 110 by the connected portion between the adjacent second through-portions 1320 located at the corner. That is, by the combination of the first through-portion 1310 and the second through-portion 1320, the through-portion 130 is provided to surround the central portion 110 on the entire circumference of the outer side of the central portion 110. Thus, it is possible to suppress the obstruction of the vibration of the central portion 110 by the connected portion, that is, a portion between the adjacent second through-portions 1320 of the connecting portion 140, and improve the displacement of the central portion 110. In addition, in this case, the plan view shape of the connecting portion 140 is a substantially V-shaped shape corresponding to the combination of the first through-portion 1310 and the second through-portion 1320. That is, the connecting portion 140 has a portion parallel to the two adjacent sides of the central portion 110. Therefore, the connection portion 140 can be formed longer in the portion around the central portion 110. As a result, the displacement of the central portion 110 can be sufficiently ensured, and the durability of the connection portion 140 can be improved.

[0136] In other words, by using the through portion 130 having a combined shape, it is possible to obtain the base portion 100 of the piezoelectric vibration plate 11 having high durability and good displacement performance.

[0137] Furthermore, in the above embodiment, the central portion 110 , the peripheral portion 120 , and the connecting portion 140 are integrally formed. However, the central portion 110 , the peripheral portion 120 , and the connecting portion 140 may be independently formed.

[0138] In the above embodiment, the sealing material 200 seals the entire through-portion 130, but the sealing material 200 may be configured to seal a portion of the through-portion 130. In addition, the sealing material 200 may be a film.

[0139] In addition, in the above embodiment, the structure of the lower shell 20 and the upper shell 30 composed of LCP (liquid crystal polymer) is described, but the lower shell 20 and the upper shell 30 can also be composed of SPS (syndiotactic polystyrene), PPS (polyphenylene sulfide), PBT (polybutylene terephthalate), etc., or can be composed of ceramics. In addition, the shape of the lower shell 20 and the upper shell 30 is not limited to a square box shape, for example, it can also be a cylindrical shape or a polygonal column shape.

[0140] In addition, each embodiment described above is an embodiment for facilitating the understanding of the present invention, and is not intended to limit the interpretation of the present invention. The present invention can be changed / improved within the scope of its purport, and the present invention also includes its equivalent. That is, as long as the features of the present invention are possessed, the embodiments after the technical personnel in this field appropriately apply design changes to each embodiment are also included in the scope of the present invention. For example, each element and its configuration, material, condition, shape, size, etc. possessed by each embodiment are not limited to the illustrated content and can be appropriately changed. In addition, each embodiment is illustrative, and of course, the replacement or combination of the parts of the composition shown in different embodiments can be performed, and as long as the features of the present invention are included, these embodiments are also included in the scope of the present invention.

[0141] Explanation of the reference numerals: 1… piezoelectric sound-producing component, 10… piezoelectric vibration portion, 20… lower shell, 30… upper shell, 11… piezoelectric vibration plate, 12… insulator, 13… terminal portion, 100… base portion, 110… central portion, 120… peripheral portion, 130… through portion, 140… connecting portion, 150… piezoelectric body portion, 200… sealing material, 300… opening and closing valve, 310… first valve, 320… second valve.

Claims

1. A piezoelectric vibration plate, wherein: A conductive base having a central portion and a peripheral portion located around the central portion, and a piezoelectric body portion provided at the central portion, When a voltage is applied to the piezoelectric body, the central portion performs bending vibration and reciprocates on both sides in the thickness direction of the base. The base is provided with at least one through portion located between the central portion and the peripheral portion, and at least one connecting portion connecting the central portion and the peripheral portion. The at least one connecting portion is arranged at a position farthest from the center of the central portion of the base portion where the displacement is the largest during bending vibration. The at least one through-portion has a limiting portion, which limits the air located on the first side in the thickness direction of the base portion from flowing into the second side in the thickness direction through the through-portion, and the air located on the second side in the thickness direction from flowing into the first side through the through-portion, The restricting portion is an on-off valve capable of opening and closing the at least one through-portion.

2. The piezoelectric vibration plate according to claim 1, wherein The at least one through portion is in a slit shape.

3. The piezoelectric vibration plate according to claim 2, wherein: The slit width of the slit-shaped through portion is larger than 0 mm and is equal to or smaller than 0.1 mm.

4. The piezoelectric vibration plate according to claim 1, wherein The on-off valve opens and closes the at least one through portion by bending vibration of the piezoelectric vibration plate.

5. The piezoelectric vibration plate according to claim 4, wherein The at least one through portion has a first opening located on a first side in a thickness direction of the base portion, and a second opening located on a second side in the thickness direction of the base portion, The on-off valve includes a first valve provided at the first opening and a second valve provided at the second opening. When the piezoelectric vibration plate performs a second displacement from the first side toward the second side, the second valve closes the second opening of the through portion, and when the piezoelectric vibration plate performs a first displacement from the second side toward the first side, the first valve closes the first opening of the through portion.

6. The piezoelectric vibration plate according to any one of claims 1 to 5, wherein: The central portion, the peripheral portion and the connecting portion are one component. The central portion and the base portion are rectangular in plan view. The connecting portion is provided at a corner portion of the central portion.

7. A piezoelectric vibration plate, wherein: A conductive base having a central portion and a peripheral portion located around the central portion, and a piezoelectric body portion provided at the central portion, When a voltage is applied to the piezoelectric body, the central portion performs bending vibration and reciprocates on both sides in the thickness direction of the base. The base is provided with at least one through portion located between the central portion and the peripheral portion, and at least one connecting portion connecting the central portion and the peripheral portion. The at least one through portion is in the shape of a slit having a slit width greater than 0 mm and less than 0.1 mm when viewed from above the base. The at least one through-portion has a limiting portion, which limits the air located on the first side in the thickness direction of the base portion from flowing into the second side in the thickness direction through the through-portion, and the air located on the second side in the thickness direction from flowing into the first side through the through-portion, The restricting portion is an on-off valve capable of opening and closing the at least one through-portion.

8. A piezoelectric vibration plate, wherein: A conductive base having a central portion and a peripheral portion located around the central portion, and a piezoelectric body portion provided at the central portion, When a voltage is applied to the piezoelectric body, the central portion performs bending vibration and reciprocates on both sides in the thickness direction of the base. The base is provided with at least one through portion located between the central portion and the peripheral portion, and at least one connecting portion connecting the central portion and the peripheral portion. The at least one through-portion includes a first valve provided at a first opening located on a first side in a thickness direction of the base portion, and a second valve provided at a second opening located on a second side in the thickness direction of the base portion.

9. A piezoelectric sounding component, wherein: have: A piezoelectric vibration portion comprising the piezoelectric vibration plate according to any one of claims 1 to 8, and an input / output terminal for applying a voltage to the piezoelectric vibration plate; and The housing portion holds the piezoelectric vibrating portion.

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