Vibratory wave radiation device

Abstract

If a distance between the connecting portion (121) in a direction perpendicular to the reflecting surface portion (130) and the reflecting surface portion (130) is set as TD, an angle formed by an imaginary line (VL) parallel to the reflecting surface portion (130) and the back surface (120b) of the vibrating portion (122) in a longitudinal cross section is set as θ, a shortest distance between the periphery (123) of the back surface (120b) at the front end on the side opposite to the connecting portion (121) of the vibrating portion (122) and the periphery of the reflecting surface portion (130) is set as L, and a wavelength of the vibration wave emitted from the vibrating portion (122) is set as λ, in a range of TD = 0 and 35° ≤ θ ≤ 55°, a relation of 0.78λ ≤ L ≤ 1.19λ or 1.5λ ≤ L ≤ 2.14λ is satisfied.

Description

Technical Field

[0001] This invention relates to a vibration wave radiation device. Background Technology

[0002] As a prior art document disclosing the structure of an ultrasonic transmitter, there is Japanese Patent Application Publication No. 9-327095 (Patent Document 1). The ultrasonic transmitter described in Patent Document 1 includes a vibrator, a conical vibrator, a conical horn, and a base.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-327095 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In order to achieve a large sound pressure output by adjusting the phase of the reflected wave of the ultrasonic wave radiated from the back of the conical vibrator, it is necessary to specify the relationship between the size of the conical vibrator and the size of the reflecting surface, but this relationship is not considered in Patent Document 1.

[0008] The present invention was made in view of the above-mentioned problems, and its object is to provide a vibration wave radiation device capable of generating high sound pressure vibration waves.

[0009] Technical solutions for solving the problem

[0010] The vibration wave radiation device according to the present invention includes an oscillator, a vibrating body, and a reflective surface. The oscillator generates vibration. The vibrating body is connected to the oscillator and has a surface and a back surface located off-center from the oscillator and opposite to the surface. The reflective surface is spaced apart from the back surface of the vibrating body and faces it. The vibrating body includes a connecting portion and a vibrating portion. The connecting portion is connected to the oscillator. The vibrating portion extends from the end of the connecting portion opposite to the oscillator side and extends away from the reflective surface, having the back surface opposite to the reflective surface. In longitudinal section, the vibrating portion extends in a straight line from the connecting portion and has a cylindrical shape. Viewed from a direction perpendicular to the reflective surface, the periphery of the reflective surface is coaxial with the central axis of the vibrating portion and located outside the vibrating portion. If the distance between the connecting part and the reflective surface in the direction perpendicular to the reflective surface is TD, and the angle between the imaginary line parallel to the reflective surface and the back surface of the vibrating part in the above longitudinal section is θ, and the shortest distance between the periphery of the back surface of the vibrating part at the front end opposite to the connecting part and the periphery of the reflective surface is L, and the wavelength of the vibration wave emitted from the vibrating part is λ, then within the range of TD=0 and 35°≤θ≤55°, the relationship 0.78λ≤L≤1.19λ or 1.5λ≤L≤2.14λ is satisfied.

[0011] Invention Effects

[0012] According to the present invention, it is possible to generate vibration waves with high sound pressure. Attached Figure Description

[0013] Figure 1 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 1 of the present invention.

[0014] Figure 2 Viewed from the direction of arrow II Figure 1 A top view of the vibration wave radiation device.

[0015] Figure 3 It is a partial cross-sectional view schematically showing the state in which the phase of the reflected wave of the vibration wave radiated from the back of the vibrating part varies with the size of the reflecting surface.

[0016] Figure 4 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 1 of the present invention.

[0017] Figure 5 This is a graph showing the relationship between the sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 1 of the present invention.

[0018] Figure 6 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 2 of the present invention.

[0019] Figure 7 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 2 of the present invention.

[0020] Figure 8 This is a graph showing the relationship between the sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 2 of the present invention.

[0021] Figure 9 This is a longitudinal sectional view showing the structure of a vibration wave radiation device according to a modified example of Embodiment 2 of the present invention.

[0022] Figure 10 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 3 of the present invention.

[0023] Figure 11 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 3 of the present invention.

[0024] Figure 12This is a graph showing the relationship between the sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 3 of the present invention.

[0025] Figure 13 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 4 of the present invention.

[0026] Figure 14 Viewed from the direction of arrow XIV Figure 13 A top view of the vibration wave radiation device.

[0027] Figure 15 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 4 of the present invention.

[0028] Figure 16 This is a graph showing the relationship between the sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 4 of the present invention. Detailed Implementation

[0029] Hereinafter, the vibration wave radiation device according to various embodiments of the present invention will be described with reference to the accompanying drawings. In the following description of the embodiments, the same or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0030] (Implementation Method 1)

[0031] Figure 1 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 1 of the present invention. Figure 2 Viewed from the direction of arrow II Figure 1 A top view of a vibration wave radiating device. (e.g.) Figure 1 as well as Figure 2 As shown, the vibration wave radiation device 100 according to Embodiment 1 of the present invention includes an oscillator 110, a vibrating body 120, and a reflective surface 130.

[0032] The oscillator 110 vibrates. In this embodiment, the oscillator 110 includes an electromechanical conversion element 111 and a vibration transmission body 112. The electromechanical conversion element 111 is composed of a piezoelectric element, a magnetostrictive element, or an electrostrictive element, etc. The vibration transmission body 112 is made of metal or resin. The oscillator 110 has a cylindrical shape.

[0033] The oscillator 110 is, for example, a Langevin-type oscillator, a monomorph-type oscillator, or a bimorph-type oscillator, in which one or more electromechanical conversion elements and one or more other components are integrally formed.

[0034] The vibrator 120 is connected to the oscillator 110 and has a surface 120f and a back surface 120b located off the oscillator 110 and opposite to the surface 120f. The vibrator 120 includes a connecting portion 121 and a vibrating portion 122.

[0035] The connecting portion 121 is connected to the oscillator 110. In this embodiment, the connecting portion 121 has a cylindrical shape extending in a direction perpendicular to the reflective surface 130. However, the shape of the connecting portion 121 is not limited to a cylindrical shape, and may also be a pin shape or a hemispherical shape, etc.

[0036] The vibrating section 122 extends from the end of the connecting section 121 opposite to the vibrator 110 side and extends away from the reflective surface 130, having a back surface 120b opposite to the reflective surface 130. In longitudinal section, the vibrating section 122 extends in a straight line from the connecting section 121, having a cylindrical shape. That is, the vibrating section 122 has a conical horn shape that is rotationally symmetrical about the central axis C. The periphery 123 of the back surface 120b at the front end of the vibrating section 122 opposite to the connecting section 121 side has an annular shape. Furthermore, the shape of the vibrating section 122 is not limited to a conical horn; it can be any shape that forms an open space for the propagation of vibration waves between the back surface 120b of the vibrating section 122 and the reflective surface 130.

[0037] The vibrator 120 may be made of metals such as aluminum alloy, stainless steel, nickel alloy or copper alloy, or resin. The vibrator 120 may be integrally formed of the same material as the components constituting the oscillator 110 or the reflector 130, or it may be other components connected to the components constituting the oscillator 110 or the reflector 130.

[0038] The reflective surface 130 is positioned opposite the back surface 120b of the vibrator 120, with a gap between them. In this embodiment, the reflective surface 130 is the surface of the vibrator 120 side of the oscillator 110. Alternatively, the reflective surface 130 may be constructed from a different component than the oscillator 110. In this case, the material of the reflective surface 130 may be, for example, a metal such as aluminum alloy, stainless steel, nickel alloy, or copper alloy, or resin.

[0039] like Figure 2 As shown, when viewed from a direction perpendicular to the reflective surface 130, the periphery of the reflective surface 130 is a circle located coaxially with the central axis C of the vibrating part 122 and outside the vibrating part 122. That is, the radius of the periphery of the reflective surface 130 is larger than the radius of the periphery of the vibrating part 122. Furthermore, when viewed from a direction perpendicular to the reflective surface 130, the periphery of the reflective surface 130 is not limited to a circle.

[0040] Here, the mechanism by which the sound pressure of the vibration wave radiated from the vibration wave radiating device 100 varies according to the relationship between the size of the vibrating part 122 and the size of the reflecting part 130 will be explained.

[0041] Figure 3 It is a partial cross-sectional view schematically showing the state in which the phase of the reflected wave of the vibration wave radiated from the back of the vibrating part varies with the size of the reflecting surface.

[0042] like Figure 3 As shown, if the vibrating body 120 vibrates, the vibrating part 122 shakes as indicated by arrow 1. Consequently, from the surface 120f of the vibrating part 122... Figure 3 The upper part of the vibration wave U1 radiates from the back side 120b of the vibration unit 122 towards... Figure 3 The vibration wave U2 radiates from below. Vibration wave U2 is reflected at the reflecting surface 130° and directed towards... Figure 3 It spreads upwards.

[0043] Assuming that the radius of the periphery of the reflective surface 130 is smaller than the radius of the periphery of the vibrating part 122, the vibration wave U2 cannot be reflected by the reflective surface 130 and directed towards... Figure 3 It spreads fully above.

[0044] On the other hand, when the radius of the periphery of the reflective surface 130 is larger than the radius of the periphery of the vibrating part 122, a shift occurs in the phase of the reflected wave based on the distance from the vibration wave U2 to the reflective surface 130. Figure 3 The reflected waves U3 and U5 shown are in phase with the vibration wave U1, while the reflected wave U4 is out of phase with the vibration wave U1. Due to the interference between these reflected waves, sometimes the reflected waves do not... Figure 3 The sound waves propagate sufficiently above the vibration wave radiating device. That is, in order to increase the sound pressure of the vibration wave radiated from the vibration wave radiating device, the size of the reflective surface 130 needs to be appropriately set according to the size of the vibration part 122.

[0045] Specifically, if the position of the periphery of the reflective surface 130 is set to S1, the sound pressure of the vibration wave radiated from the vibration wave radiating device can be increased by the reflected wave U3. If the position of the periphery of the reflective surface 130 is set to S2, the vibration wave radiated from the vibration wave radiating device is weakened due to the addition of the reflected wave U4, and the sound pressure of the vibration wave cannot be increased. If the position of the periphery of the reflective surface 130 is set to S3, the sound pressure of the vibration wave radiated from the vibration wave radiating device can be increased by the addition of the reflected wave U5. In this way, as the reflective surface 130 becomes larger, regions that mutually reinforce and mutually weaken the vibration waves are alternately generated.

[0046] The following describes the simulation analysis results using the finite element method related to the vibration wave radiation device according to Embodiment 1 of the present invention. In the following simulation analysis, the speed of sound in air is set to 340 m / s.

[0047] Figure 4 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 1 of the present invention. Figure 4 In the longitudinal section shown, the direction parallel to the reflective surface 130 is designated as the X-axis direction, and the direction perpendicular to the reflective surface 130 is designated as the Y-axis direction.

[0048] The radius of the oscillator 110, i.e., the radius of the periphery of the reflective surface 130, is set as R1. The radius of the inner side of the connecting part 121 is set as R2. The radius of the periphery of the back surface 120b at the front end of the vibrating part 122 is set as R3.

[0049] The thickness of the electromechanical conversion element 111 is defined as T1. The thickness of the vibration transmission body 112 is defined as T2. The height of the connecting part 121 is defined as T3. The height of the back surface 120b of the vibration part 122 in the Y-axis direction is defined as T4.

[0050] The thickness of the connecting portion 121 is set to W1. The width of the back surface 120b of the vibrating portion 122 in the X-axis direction is set to W2. The thickness of the vibrating portion 122 is set to W3. The distance in the X-axis direction between the periphery 123 of the back surface 120b of the vibrating portion 122 at the front end opposite to the connecting portion 121 and the periphery of the reflective surface 130 is set to W4.

[0051] The dimension of the gap between the connecting part 121 and the reflective surface 130 in the Y-axis direction is set as TD. Figure 4 In the longitudinal section shown, the angle between the imaginary line VL parallel to the reflective surface 130 and the back surface 120b of the vibrating part 122 is defined as θ. The shortest distance between the periphery 123 of the back surface 120b at the front end of the vibrating part 122 opposite to the connecting part 121 and the periphery of the reflective surface 130 is defined as L. The wavelength of the vibration wave emitted from the vibrating part 122 is defined as λ.

[0052] Using R1 as a parameter, simulation analysis was conducted for cases where TD = 0 and angle θ is 35°, 45°, and 55° within the range of 5.4mm ≤ R1 ≤ 15mm (0mm ≤ W4 ≤ 7mm).

[0053] Regarding other dimensions, let R2 = 3.5mm, R3 = 5.6mm, T1 = 0.4mm, T2 = 13mm, W1 = 0.6mm, W2 = 1.5mm, and W3 = 0.6mm. Let T3 + T4 = 2.2mm, and adjust the values ​​of T3 and T4 appropriately according to the angle θ. Furthermore, for example, R2 can also be 0mm or more and 10mm or less. T1 can also be 0.1mm or more and 5mm or less. T2 can also be 0.1mm or more and 30mm or less. T3 can also be 0mm or more and 15mm or less. T4 can also be 0.2mm or more and 10mm or less. W1 can also be 0.1mm or more and 10mm or less. W2 can also be 0.2mm or more and 10mm or less. W3 can also be 0.1mm or more and 5mm or less. The shortest distance (T3+T4) between the periphery 123 of the back surface 120b of the vibrating part 122 on the front end opposite to the connecting part 121 and the reflective surface 130 preferably satisfies the relationship 0.5λ≤T3+T4≤0.9λ.

[0054] A piezoelectric element is used as the electromechanical conversion element 111. The vibration transmitter 112 and the vibrator 120 are each made of aluminum alloy (A7075).

[0055] A voltage of 2Vpp with a frequency of 114kHz (λ=2.98mm) was applied to the piezoelectric element to drive the oscillator 110. In the vibration wave radiation device according to Embodiment 1 of the present invention, the maximum sound pressure of the vibration wave at a position 50mm away from the front end of the vibrator 120 in the Y-axis direction before driving was calculated on the central axis C.

[0056] Figure 5 This is a graph showing the relationship between sound pressure per unit vibration velocity and the shortest distance L in a simulation analysis of the vibration wave radiation device according to Embodiment 1 of the present invention. Figure 5 In the figure, the vertical axis shows the sound pressure per unit vibration velocity (Pa / (m / s)), and the horizontal axis shows the shortest distance L (mm).

[0057] like Figure 5 As shown, for any value of angle θ, such as 35°, 45°, and 55°, the sound pressure per unit vibration velocity varies periodically with respect to the shortest distance L. This is because the interference state between reflected waves varies depending on the size of the reflective surface 130. To increase the sound pressure per unit vibration velocity, the following condition is preferably satisfied.

[0058] When the angle θ = 35°, it is preferable to satisfy the relationship 0.75λ ≤ L ≤ 1.19λ or 1.47λ ≤ L. Furthermore, it is more preferable to satisfy the relationship 1.65λ ≤ L ≤ 1.96λ or 2.14λ ≤ L.

[0059] When the angle θ = 45°, it is preferable to satisfy the relationship 0.78λ ≤ L ≤ 1.3λ or 1.5λ ≤ L. Furthermore, it is more preferable to satisfy the relationship 0.84λ ≤ L ≤ 1.19λ or 1.65λ ≤ L ≤ 1.89λ.

[0060] When the angle θ = 55°, it is preferable to satisfy the relationship 0.74λ ≤ L ≤ 2.14λ. Furthermore, it is more preferable to satisfy the relationship 0.75λ ≤ L ≤ 2.08λ.

[0061] Based on the simulation analysis results above, in the vibration wave radiation device according to Embodiment 1 of the present invention, in order to increase the sound pressure per unit vibration velocity, within the range of TD=0 and 35°≤θ≤55°, it is preferable to satisfy the relationship 0.78λ≤L≤1.19λ or 1.5λ≤L≤2.14λ. Furthermore, from the viewpoint of suppressing the enlargement of the vibration wave radiation device, within the range of TD==0 and 35°≤θ≤55°, it is preferable to satisfy the relationship 0.78λ≤L≤1.19λ or 1.5λ≤L≤2λ.

[0062] (Implementation Method 2)

[0063] Hereinafter, the vibration wave radiation device according to Embodiment 2 of the present invention will be described with reference to the figures. The vibration wave radiation device according to Embodiment 2 of the present invention differs from the vibration wave radiation device 100 according to Embodiment 1 of the present invention mainly in the structure of the oscillator and the vibrating body. Therefore, the same structure as that of the vibration wave radiation device 100 according to Embodiment 1 of the present invention will not be described again.

[0064] Figure 6 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 2 of the present invention. Figure 6 As shown, the vibration wave radiation device 200 according to Embodiment 2 of the present invention includes an oscillator 210, a vibrating body 220, and a reflective surface 230.

[0065] In this embodiment, the oscillator 210 includes a first electromechanical conversion element 211, a second electromechanical conversion element 212, a first vibration transmitter 213, a second vibration transmitter 214, a third vibration transmitter 215, and a support body 216. The oscillator 210 is a so-called Langevin-type oscillator. The oscillator 210 has a generally cylindrical shape. The support body 216 protrudes from the outer peripheral surface of the oscillator 210 in the shape of a circular plate. In addition, the support body 216 only needs to protrude from the outer peripheral surface of the oscillator 210, and its shape is not limited to a circular plate. Furthermore, the support body 216 is not limited to protruding from the entire circumference of the outer periphery of the oscillator 210, but may also protrude from a portion of the outer periphery of the oscillator 210.

[0066] On one surface of the support 216, a first electromechanical conversion element 211, a first vibration transmitter 213, and a third vibration transmitter 215 are stacked sequentially. On the other surface of the support 216, a second electromechanical conversion element 212 and a second vibration transmitter 214 are stacked sequentially.

[0067] The first electromechanical conversion element 211 and the second electromechanical conversion element 212 are each composed of a piezoelectric element, a magnetostrictive element, or an electrostrictive element, etc. The first vibration transmitter 213, the second vibration transmitter 214, and the third vibration transmitter 215 are each composed of metal or resin. The support body 216 is composed of metal or resin.

[0068] The vibrator 220 is connected to the oscillator 210 and has a surface 220f and a back surface 220b located off the oscillator 210 and opposite to the surface 220f. The vibrator 220 includes a connecting portion 221 and a vibrating portion 222.

[0069] The connecting portion 221 is connected to the oscillator 210. In this embodiment, the connecting portion 221 has a cylindrical shape extending in a direction perpendicular to the reflective surface 230. However, the shape of the connecting portion 221 is not limited to a cylindrical shape, and may also be a pin shape or a hemispherical shape, etc.

[0070] The vibrating portion 222 extends from the end of the connecting portion 221 opposite to the vibrator 210 side and extends away from the reflective surface 230, having a back surface 220b opposite to the reflective surface 230. In longitudinal section, the vibrating portion 222 expands in a convex arc or elliptical arc shape from the connecting portion 221 towards the surface 220f side, having a cylindrical shape. That is, the vibrating portion 222 has a trumpet shape that is rotationally symmetrical about the central axis C. The periphery 223 of the back surface 220b at the front end of the vibrating portion 222 opposite to the connecting portion 221 side has an annular shape. Furthermore, the shape of the vibrating portion 222 is not limited to a trumpet shape; it can be any shape that forms an open space for the propagation of vibration waves between the back surface 220b of the vibrating portion 222 and the reflective surface 230.

[0071] The vibrator 220 can be made of metals such as aluminum alloy, stainless steel, nickel alloy or copper alloy, or resin. The vibrator 220 can be integrally formed of the same material as the components constituting the oscillator 210 or the reflector 230, or it can be other components connected to the components constituting the oscillator 210 or the reflector 230.

[0072] The reflective surface 230 is positioned opposite the back surface 220b of the vibrator 220, with a gap between them. In this embodiment, the reflective surface 230 is the surface of the vibrator 220 side of the oscillator 210. Alternatively, the reflective surface 230 may be constructed from a different component than the oscillator 210. In this case, the material of the reflective surface 230 may be, for example, a metal such as aluminum alloy, stainless steel, nickel alloy, or copper alloy, or resin.

[0073] Viewed from a direction perpendicular to the reflective surface 230, the periphery of the reflective surface 230 is a circle located coaxially with the central axis C of the vibrating part 222 and outside the vibrating part 222. That is, the radius of the periphery of the reflective surface 230 is larger than the radius of the periphery of the vibrating part 222. Furthermore, viewed from a direction perpendicular to the reflective surface 230, the periphery of the reflective surface 230 is not limited to a circle.

[0074] The following describes the simulation analysis results using the finite element method related to the vibration wave radiation device according to Embodiment 2 of the present invention.

[0075] Figure 7 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 2 of the present invention. Figure 7 In the longitudinal section shown, the direction parallel to the reflective surface 230 is defined as the X-axis direction, and the direction perpendicular to the reflective surface 230 is defined as the Y-axis direction.

[0076] The radius of the oscillator 210, i.e., the radius of the periphery of the reflector 230, is set as R1. The radius of the inner side of the connecting part 221 is set as R2. The radius of the periphery of the back surface 220b at the front end of the vibrating part 222 is set as R3. The radius of the periphery of the support 216 is set as R4.

[0077] The thickness of the oscillator 210 is defined as T10. The thickness of the second vibration transmitter 214 is defined as T11. The thickness of the second electromechanical conversion element 212 is defined as T12. The thickness of the support 216 is defined as T13. The thickness of the first electromechanical conversion element 211 is defined as T14. The thickness of the first vibration transmitter 213 is defined as T15. The thickness of the third vibration transmitter 215 is defined as T16.

[0078] The height of the connecting part 221 is set to T3. The height of the back surface 220b of the vibrating part 222 in the Y-axis direction is set to T4.

[0079] The thickness of the connecting portion 221 is set to W1. The width of the back surface 220b of the vibrating portion 222 in the X-axis direction is set to W2. The thickness of the vibrating portion 222 is set to W3. The distance in the X-axis direction between the periphery 223 of the back surface 220b of the vibrating portion 222 at the front end opposite to the connecting portion 221 and the periphery of the reflective surface 230 is set to W4.

[0080] The dimension of the gap between the connecting part 221 and the reflective surface 230 in the Y-axis direction is set as TD. Figure 7 In the longitudinal section shown, the angle between the imaginary line VL parallel to the reflective surface 230 and the straight line CL connecting the front end and root of the back surface 220b of the vibrating part 222 is defined as θ. Figure 7 The aspect ratio of the back surface 220b of the vibrating part 222 in the longitudinal section shown is set to AR. Furthermore, the relationship AR = W² / T⁴ is satisfied. The shortest distance between the periphery 223 of the back surface 220b at the front end of the vibrating part 222 opposite to the connecting part 221 and the periphery of the reflecting surface 230 is set to L. The wavelength of the vibration wave emitted from the vibrating part 222 is set to λ.

[0081] Using R1 as a parameter, simulation analysis was conducted for the cases where TD = 0 and T4 is 0.5mm, 0.75mm, 1mm, 1.6mm, and 1.79mm, within the range of 5.7mm ≤ R1 ≤ 13mm (0mm ≤ W4 ≤ 7.3mm).

[0082] Regarding the other dimensions, let R2 = 3.5mm, R3 = 5.7mm, R4 = R1 + 2mm, T11 = 5mm, T12 = 0.4mm, T13 = 0.5mm, T14 = 0.4mm, T15 = 5mm, T16 = 1mm, W1 = 0.6mm, W2 = 1.6mm, and W3 = 0.6mm. Let T3 + T4 = 1.8mm, and adjust the value of T3 accordingly based on the value of T4. When T4 changes from 0.5mm to 1.79mm, the angle θ changes from 17.4° to 48.2°.

[0083] Furthermore, for example, R2 can be 0 mm or more and 10 mm or less. T11 can be 0.1 mm or more and 30 mm or less. T12 can be 0.1 mm or more and 5 mm or less. T13 can be 0.1 mm or more and 5 mm or less. T14 can be 0.1 mm or more and 5 mm or less. T15 can be 0.1 mm or more and 30 mm or less. T16 can be 0.1 mm or more and 5 mm or less. T3 can be 0 mm or more and 15 mm or less. T4 can be 0.2 mm or more and 10 mm or less. W1 can be 0.1 mm or more and 10 mm or less. W2 can be 0.2 mm or more and 10 mm or less. W3 can be 0.1 mm or more and 5 mm or less. The shortest distance (T3+T4) between the periphery 223 of the back surface 220b of the vibrating part 222 on the front end opposite to the connecting part 221 and the reflective surface 230 preferably satisfies 0.5λ≤T3+T4≤0.9λ.

[0084] Piezoelectric elements are used as the first electromechanical conversion element 211 and the second electromechanical conversion element 212, respectively. The first vibration transmitter 213, the second vibration transmitter 214, and the support 216 are each made of nickel alloy (42Ni). The third vibration transmitter 215 and the vibrator 220 are each made of aluminum alloy (A7075).

[0085] A voltage of 2Vpp with a frequency of 114.1kHz (λ=2.98mm) was applied to the piezoelectric element to drive the oscillator 210. In the vibration wave radiation device according to Embodiment 2 of the present invention, the maximum sound pressure of the vibration wave at a position 50mm away from the front end of the vibrator 220 in the Y-axis direction before driving was calculated on the central axis C.

[0086] Figure 8 This is a graph showing the relationship between sound pressure per unit vibration velocity and the shortest distance L in a simulation analysis of the vibration wave radiation device according to Embodiment 2 of the present invention. Figure 8 In the figure, the vertical axis shows the sound pressure per unit vibration velocity (Pa / (m / s)), and the horizontal axis shows the shortest distance L (mm).

[0087] like Figure 8 As shown, for any value of T4 from 0.5 mm to 1.79 mm, the sound pressure per unit vibration velocity varies periodically with respect to the shortest distance L. To increase the sound pressure per unit vibration velocity, the following condition is preferably satisfied.

[0088] When T4 is 1 mm or more and 1.79 mm or less, it is preferable to satisfy the relationship 0.63λ≤L.

[0089] When T4 is 1.79 mm, it is preferable to satisfy the relationship 0.68λ≤L≤1.15λ or 1.38λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.68λ≤L≤1.03λ, 1.5λ≤L≤1.88λ, or 2.26λ≤L.

[0090] When T4 is 1.6 mm, it is preferable to satisfy the relationships 0.68λ≤L≤1.03λ, 1.5λ≤L≤1.88λ, or 2.26λ≤L.

[0091] When T4 is 1 mm, it is preferable to satisfy the relationship 0.63λ≤L≤2λ or 2.26λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.68λ≤L≤1.03λ or 1.5λ≤L≤1.75λ.

[0092] When T4 is 0.75 mm, it is preferable to satisfy the relationship 0.6λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.63λ≤L≤2λ.

[0093] When T4 is 0.5 mm, it is preferable to satisfy the relationship 0.83λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.92λ≤L≤1.26λ or 1.75λ≤L.

[0094] Based on the simulation analysis results above, in the vibration wave radiation device according to Embodiment 2 of the present invention, in order to increase the sound pressure per unit vibration velocity, within the range of TD = 0 and 0.9 ≤ AR ≤ 3.2, it is preferable to satisfy the relationship 0.83λ ≤ L. Furthermore, from the viewpoint of suppressing the enlargement of the vibration wave radiation device, within the range of TD = 0 and 0.9 ≤ AR ≤ 3.2, it is preferable to satisfy the relationship 0.83λ ≤ L ≤ 2λ.

[0095] Alternatively, the vibration wave radiation device can also be housed within the casing. Figure 9 This is a longitudinal sectional view showing the structure of a vibration wave radiation device according to a modified embodiment 2 of the present invention. Figure 9 As shown, the vibration wave radiation device 200a according to the modified embodiment 2 of the present invention further includes a housing 240, an electrode 250, and wiring 260.

[0096] The housing 240 houses an oscillator 210, a vibrating body 220, and a reflective surface 230. The top surface of the housing 240 is open. Alternatively, the top surface of the housing 240 may be covered by a mesh structure through which vibration waves can be transmitted. An electrode 250 extends outward from the bottom of the housing 240. The electrode 250 is electrically connected to the oscillator 210 via wiring 260. This modified structure can also be applied to vibration wave radiating devices according to other embodiments.

[0097] (Implementation Method 3)

[0098] Hereinafter, the vibration wave radiation device according to Embodiment 3 of the present invention will be described with reference to the figures. The vibration wave radiation device according to Embodiment 3 of the present invention mainly differs from the vibration wave radiation device 100 according to Embodiment 1 of the present invention in the structures of the oscillator and the reflector. Therefore, the structures that are the same as those of the vibration wave radiation device 100 according to Embodiment 1 of the present invention will not be described again.

[0099] Figure 10 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 3 of the present invention. Figure 10 As shown, the vibration wave radiation device 300 according to Embodiment 3 of the present invention includes an oscillator 310, a vibrating body 120, and a reflective surface 330.

[0100] In this embodiment, the oscillator 310 includes an electromechanical conversion element 311 and a vibration transmission element 312. The vibration transmission element 312 is made of metal or resin. The oscillator 310 has a cylindrical shape.

[0101] The reflective surface 330 is positioned opposite the back surface 120b of the vibrator 120, with a gap between them. In this embodiment, the reflective surface 330 is the surface of the plate 340 on the vibrator 120 side, which is a component different from the oscillator 310. The plate 340 has an annular shape and is coaxially configured with the oscillator 310, thereby surrounding the oscillator 310. The plate 340 and the oscillator 310 can be either connected to or separated from each other. The material of the plate 340 can be, for example, a metal such as aluminum alloy, stainless steel, nickel alloy, or copper alloy, or resin.

[0102] Viewed from a direction perpendicular to the reflective surface 330, the periphery of the reflective surface 330 is a circle located coaxially with the central axis C of the vibrating part 122 and outside the vibrating part 122. That is, the radius of the periphery of the reflective surface 330 is larger than the radius of the periphery of the vibrating part 122. In addition, viewed from a direction perpendicular to the reflective surface 330, the periphery of the reflective surface 330 is not limited to a circle.

[0103] The following describes the simulation analysis results using the finite element method related to the vibration wave radiation device according to Embodiment 3 of the present invention.

[0104] Figure 11 This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 3 of the present invention. Figure 11 In the longitudinal section shown, the direction parallel to the reflective surface 330 is defined as the X-axis direction, and the direction perpendicular to the reflective surface 330 is defined as the Y-axis direction.

[0105] The radius of the oscillator 310 is set to R1. The radius of the inner side of the connecting part 121 is set to R2. The radius of the periphery of the back surface 120b at the front end of the vibrating part 122 is set to R3. The radius of the periphery of the reflective surface 330 is set to R4.

[0106] The thickness of the electromechanical conversion element 311 is defined as T1. The thickness of the vibration transmission body 312 is defined as T2. The height of the connecting part 121 is defined as T3. The height of the back surface 120b of the vibration part 122 in the Y-axis direction is defined as T4. The thickness of the plate 340 is defined as T5.

[0107] The thickness of the connecting portion 121 is set to W1. The width of the back surface 120b of the vibrating portion 122 in the X-axis direction is set to W2. The thickness of the vibrating portion 122 is set to W3. The distance in the X-axis direction between the periphery 123 of the back surface 120b of the vibrating portion 122 at the front end opposite to the connecting portion 121 and the periphery of the reflective surface 330 is set to W4.

[0108] The dimension of the gap between the connecting part 121 and the reflective surface 330 in the Y-axis direction is set as TD. Figure 11 In the longitudinal section shown, the angle between the imaginary line VL parallel to the reflective surface 330 and the back surface 120b of the vibrating part 122 is defined as θ. The shortest distance between the periphery 123 of the back surface 120b at the front end of the vibrating part 122 opposite to the connecting part 121 and the periphery of the reflective surface 330 is defined as L. The wavelength of the vibration wave emitted from the vibrating part 122 is defined as λ.

[0109] Using R4 and TD as parameters, simulation analysis was conducted for cases where TD is 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.9mm, and 1.1mm, within the range of 5.4mm≤R4≤15mm (0mm≤W4≤7mm).

[0110] Regarding other dimensions, let R1 = 4.1mm, R2 = 3.5mm, R3 = 5.6mm, T1 = 0.4mm, T2 = 7.6mm, T3 = 0.1mm, T4 = 1.5mm, T5 = 1mm, W1 = 0.6mm, W2 = 1.5mm, and W3 = 0.6mm. Let angle θ be 45°. The shortest distance (T3 + T4 + TD) between the periphery 123 of the back surface 120b of the vibrating part 122 at the front end opposite to the connecting part 121 and the reflective surface 330 preferably satisfies 0.5λ ≤ T3 + T4 + TD ≤ 0.9λ.

[0111] A piezoelectric element is used as the electromechanical conversion element 311. The vibration transmitter 312 and the vibrator 120 are each made of aluminum alloy (A7075). The plate 340 is made of ABS resin. The plate 340 and the vibrator 310 are slightly separated from each other, so that the plate 340 does not vibrate.

[0112] A voltage of 2Vpp with a frequency of 116.6kHz (λ=3.01mm) was applied to the piezoelectric element to drive the oscillator 310. In the vibration wave radiation device according to Embodiment 3 of the present invention, the maximum sound pressure of the vibration wave at a position 50mm away from the front end of the vibrator 120 in the Y-axis direction before driving was calculated on the central axis C.

[0113] Figure 12 This is a graph showing the relationship between sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 3 of the present invention. Figure 12 In the figure, the vertical axis shows the sound pressure per unit vibration velocity (Pa / (m / s)), and the horizontal axis shows the shortest distance L (mm).

[0114] like Figure 12 As shown, for any value of TD from 0.1 mm to 1.1 mm, the sound pressure per unit vibration velocity varies periodically with respect to the shortest distance L. To increase the sound pressure per unit vibration velocity, the following condition is preferably satisfied.

[0115] When TD is 0.1 mm, it is preferable to satisfy the relationship 1.01λ≤L≤1.3λ or 1.81λ≤L≤2.07λ.

[0116] When TD is 0.3 mm, it is preferable to satisfy the relationship 0.85λ≤L≤1.28λ or 1.64λ≤L≤2.16λ. Furthermore, it is more preferable to satisfy the relationship 1λ≤L≤1.16λ or 1.83λ≤L≤1.9λ.

[0117] When TD is 0.5 mm, it is preferable to satisfy the relationship 0.8λ≤L≤1.31λ or 1.55λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.87λ≤L≤1.2λ or 1.67λ≤L≤1.99λ.

[0118] When TD is 0.7 mm, it is preferable to satisfy the relationship 0.79λ≤L≤1.3λ or 1.52λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.86λ≤L≤1.19λ or 1.7λ≤L≤2.01λ.

[0119] When TD is 0.9 mm, it is preferable to satisfy the relationships 0.86λ≤L≤1.25λ, 1.56λ≤L≤2.04λ, or 2.36λ≤L.

[0120] When TD is 1.1 mm, it is preferable to satisfy the relationship 0.93λ≤L≤1.15λ or 1.66λ≤L≤1.83λ.

[0121] Based on the simulation analysis results above, in the vibration wave radiation device involved in Embodiment 3 of the present invention, in order to increase the sound pressure per unit vibration velocity, within the range of θ=45° and 0.1≤TD≤1.1, it is preferable to satisfy the relationship of 1.01λ≤L≤1.15λ or 1.81λ≤L≤1.83λ.

[0122] (Implementation Method 4)

[0123] Hereinafter, the vibration wave radiation device according to Embodiment 4 of the present invention will be described with reference to the figures. The vibration wave radiation device according to Embodiment 4 of the present invention differs from the vibration wave radiation device 300 according to Embodiment 3 of the present invention mainly in the structure of the vibrating body and the reflective surface, so the same structure as the vibration wave radiation device 300 according to Embodiment 3 of the present invention will not be described again.

[0124] Figure 13 This is a longitudinal sectional view showing the structure of the vibration wave radiation device according to Embodiment 4 of the present invention. Figure 14 Viewed from the direction of arrow XIV Figure 13 A top view of a vibration wave radiating device. (e.g.) Figure 13 as well as Figure 14 As shown, the vibration wave radiation device 400 according to Embodiment 4 of the present invention includes an oscillator 410, a vibrating body 420, and a reflective surface 430.

[0125] In this embodiment, the oscillator 410 includes an electromechanical conversion element 411 and a vibration transmission element 412. The oscillator 410 has a quadrangular prism shape.

[0126] The vibrator 420 is connected to the oscillator 410 and has a surface 420f and a back surface 420b located off the oscillator 410 and opposite to the surface 420f. The vibrator 420 includes a connecting portion 421 and a pair of vibrating portions 422.

[0127] The connecting portion 421 is connected to the oscillator 410. In this embodiment, the connecting portion 421 has the shape of a pair of plates that extend in a direction perpendicular to the reflective surface 430 and are spaced apart from each other. However, the shape of the connecting portion 421 is not limited to a pair of plates, and may also be a single plate.

[0128] A pair of vibrating parts 422 separate from each other at the ends of the connecting part 421 opposite to the vibrator 410 side and extend away from the reflective surface 430, having a back surface 420b opposite to the reflective surface 430. The pair of vibrating parts 422 are inclined in longitudinal section and extend such that they separate from each other from the connecting part 421, located in positions that are linearly symmetrical about each other with respect to the central axis C. Figure 14 As shown, when viewed from a direction perpendicular to the reflective surface 430, the pair of vibrating parts 422 have a rectangular shape arranged with gaps between them. That is, the pair of vibrating parts 422 have a rectangular plate shape that is inclined to each other with gaps between them.

[0129] The edges 423 of the back surface 420b at the front end of the pair of vibrating parts 422, opposite to the side of the connecting part 421, extend in two straight lines. In addition, the shape of the pair of vibrating parts 422 is not limited to a pair of rectangular plates, as long as it forms an open space for the propagation of vibration waves between the back surface 420b of the pair of vibrating parts 422 and the reflective surface 430.

[0130] The vibrator 420 may be made of metals such as aluminum alloy, stainless steel, nickel alloy or copper alloy, or resin. The vibrator 420 may be integrally formed of the same material as the components constituting the oscillator 410 or the reflector 430, or it may be other components connected to the components constituting the oscillator 410 or the reflector 430.

[0131] The reflective surface 430 is positioned opposite the back surface 420b of the vibrator 420, with a gap between them. In this embodiment, the reflective surface 430 is the surface of the vibrator 420 side of a pair of plates 440, which are components distinct from the oscillator 410. Each of the plates 440 has a rectangular shape. The plates 440 are configured to sandwich the oscillator 410 between them. The plates 440 and the oscillator 410 can be either connected to or separated from each other. The materials of the plates 440 can be, for example, metals such as aluminum alloy, stainless steel, nickel alloy, or copper alloy, or resin.

[0132] Viewed from a direction perpendicular to the reflective surface 430, the periphery of the reflective surface 430 is a pair of rectangles that surround a pair of vibrating parts 422 from the outside. Specifically, viewed from a direction perpendicular to the reflective surface 430, the edge 431 of the reflective surface 430 on the side opposite to the vibrator 410 is located outside the edge 423 of the back surface 420b at the front end of each pair of vibrating parts 422.

[0133] The following describes the simulation analysis results using the finite element method related to the vibration wave radiation device according to Embodiment 4 of the present invention.

[0134] Figure 15This is a longitudinal sectional view showing the dimensional conditions of a simulation analysis related to the vibration wave radiation device according to Embodiment 4 of the present invention. Figure 15 In the longitudinal section shown, the direction parallel to the reflective surface 430 is defined as the X-axis direction, and the direction perpendicular to the reflective surface 430 is defined as the Y-axis direction.

[0135] R1 is defined as half the width of the oscillator 410. R2 is defined as the shortest distance in the X-axis direction from the central axis C to the connecting part 421. R3 is defined as the shortest distance in the X-axis direction from the central axis C to the edge 423 of the back surface 420b at the front end of the vibrating part 422. R4 is defined as the shortest distance in the X-axis direction from the central axis C to the edge 431 of the reflective surface 430 on the opposite side to the oscillator 410.

[0136] The thickness of the electromechanical conversion element 411 is defined as T1. The thickness of the vibration transmission body 412 is defined as T2. The height of the connecting part 421 is defined as T3. The height of the back surface 420b of the vibration part 422 in the Y-axis direction is defined as T4. The thickness of the plate 440 is defined as T5.

[0137] The thickness of the connecting portion 421 is set to W1. The width of the back surface 420b of the vibrating portion 422 in the X-axis direction is set to W2. The thickness of the vibrating portion 422 is set to W3. The distance in the X-axis direction between the edge 423 of the back surface 420b of the vibrating portion 422 at the front end opposite to the connecting portion 421 and the edge 431 of the reflective surface 430 opposite to the vibrator 410 is set to W4.

[0138] The dimension of the gap between the connecting part 421 and the reflective surface 430 in the Y-axis direction is set as TD. Figure 15 In the longitudinal section shown, the angle between the imaginary line VL parallel to the reflective surface 430 and the back surface 420b of the vibrating part 422 is defined as θ. The shortest distance between the edge 423 of the back surface 420b at the front end of the vibrating part 422 opposite to the connecting part 421 and the edge 431 of the reflective surface 430 opposite to the oscillator 410 is defined as L. The wavelength of the vibration wave emitted from the vibrating part 422 is defined as λ.

[0139] Using R4 and TD as parameters, simulation analysis was conducted for cases where TD is 1.4mm, 1.6mm, 1.8mm, 2mm, and 2.2mm, within the range of 5.4mm≤R4≤15mm (0mm≤W4≤7mm).

[0140] Regarding the other dimensions, set them as R1 = 4mm, R2 = 3mm, R3 = 5.2mm, T1 = 0.4mm, T2 = 7.6mm, T3 = 0.2mm, T4 = 1.2mm, T5 = 1mm, W1 = 1mm, W2 = 1.2mm, W3 = 1mm. The angle θ is set to 45°. The shape of the vibration wave radiation device 400 is set as... Figure 15 The planar shape shown is a three-dimensional shape extending 16 mm in the depth direction of the paper surface. The shortest distance (T3+T4+TD) between the edge 423 of the back surface 420b at the front end of the vibrating part 422 opposite to the connecting part 421 and the reflective surface 430 preferably satisfies 0.65λ≤T3+T4+TD≤0.74λ.

[0141] A piezoelectric element is used as the electromechanical conversion element 411. The vibration transmitter 412 and the vibrator 420 are each made of aluminum alloy (A7075). The plate 440 is made of ABS resin. The plate 440 and the vibrator 410 are slightly separated from each other, so that the plate 440 does not vibrate.

[0142] A voltage of 2Vpp with a frequency of 79kHz (λ=4.3mm) was applied to the piezoelectric element to drive the oscillator 410. In the vibration wave radiation device according to Embodiment 4 of the present invention, the maximum sound pressure of the vibration wave at a position 50mm away from the front end of the vibrator 420 in the Y-axis direction before driving was calculated on the central axis C.

[0143] Figure 16 This is a graph showing the relationship between sound pressure per unit vibration velocity and the shortest distance L in the simulation analysis of the vibration wave radiation device according to Embodiment 4 of the present invention. Figure 16 In the figure, the vertical axis shows the sound pressure per unit vibration velocity (Pa / (m / s)), and the horizontal axis shows the shortest distance L (mm).

[0144] like Figure 16 As shown, for any value of TD from 1.4 mm to 2.2 mm, the sound pressure per unit vibration velocity varies periodically with respect to the shortest distance L. To increase the sound pressure per unit vibration velocity, the following condition is preferably satisfied.

[0145] When TD is 1.4 mm, it is preferable to satisfy the relationship 0.65λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.8λ≤L≤1.29λ or 1.67λ≤L≤2.05λ.

[0146] When TD is 1.6 mm, it is preferable to satisfy the relationship 0.7λ≤L. Furthermore, it is more preferable to satisfy the relationship 0.81λ≤L≤1.2λ or 1.68λ≤L≤1.89λ.

[0147] When TD is 1.8mm, it is preferable to satisfy the relationship 0.74λ≤L≤1.26λ or 1.54λ≤L.

[0148] With TD values ​​of 2mm and 2.2mm, there is no region where the sound pressure level can be increased.

[0149] Based on the simulation analysis results above, in the vibration wave radiation device according to Embodiment 4 of the present invention, in order to increase the sound pressure per unit vibration velocity, within the range of θ = 45° and 1.4 ≤ TD ≤ 1.8, it is preferable to satisfy the relationship 0.74λ ≤ L ≤ 1.26λ or 1.54λ ≤ L. Furthermore, from the viewpoint of suppressing the enlargement of the vibration wave radiation device, within the range of θ = 45° and 1.4 ≤ TD ≤ 1.8, it is preferable to satisfy the relationship 0.74λ ≤ L ≤ 1.26λ or 1.54λ ≤ L ≤ 2λ.

[0150] In the above description of the embodiments, the combinable structures can also be combined with each other.

[0151] The embodiments disclosed herein should be considered illustrative and not restrictive in all respects. The scope of the invention is set forth not by the foregoing description but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0152] Explanation of reference numerals in the attached figures

[0153] 100, 200, 200a, 300, 400 vibration wave radiation devices; 110, 210, 310, 410 oscillators; 111, 311, 411 electromechanical conversion elements; 112, 312, 412 vibration transmitters; 120, 220, 420 vibrators; 120b, 220b, 420b back faces; 120f, 220f, 420f surfaces; 121, 221, 421 connecting parts; 1 Vibrating parts 22, 222, 422; periphery of 123, 223; reflective surfaces 130, 230, 330, 430; first electromechanical conversion element 211; second electromechanical conversion element 212; first vibration transmitter 213; second vibration transmitter 214; third vibration transmitter 215; support body 216; housing 240; electrode 250; wiring 260; flat plates 340, 440; edges 423, 431.

Claims

1. A vibration wave radiation device, comprising: An oscillator generates vibration; A vibrating body, connected to the oscillator, has a surface and a back surface located offset from the oscillator and opposite to the surface; and The reflective surface is positioned opposite the back surface of the vibrator, spaced apart. The vibrating body comprises: The connecting part is connected to the oscillator; and The vibrating portion extends from the end of the connecting portion opposite to the oscillator side and extends in a direction away from the reflective surface, having a back surface opposite to the reflective surface. The vibrating part extends in a straight line from the connecting part and extends in a cylindrical shape in the longitudinal section. Viewed from a direction perpendicular to the reflective surface, the periphery of the reflective surface is coaxial with the central axis of the vibrating part and located outside the vibrating part. If the distance between the connecting portion and the reflective surface in the direction perpendicular to the reflective surface is defined as TD, In the longitudinal section, the angle between the imaginary line parallel to the reflective surface and the back surface of the vibrating part is defined as θ. Let L be the shortest distance between the periphery of the back surface and the periphery of the reflective surface at the front end of the vibrating part opposite to the connecting part. Let the wavelength of the vibration wave emitted from the vibrating part be λ, then Within the range of TD = 0 and 35° ≤ θ ≤ 55°, the relationship 0.78λ ≤ L ≤ 1.19λ or 1.5λ ≤ L ≤ 2.14λ is satisfied.

2. The vibration wave radiation device according to claim 1, wherein, Within the range of TD = 0 and 35° ≤ θ ≤ 55°, the relationship 0.78λ ≤ L ≤ 1.19λ or 1.5λ ≤ L ≤ 2λ is satisfied.

3. A vibration wave radiation device, comprising: An oscillator generates vibration; A vibrating body, connected to the oscillator, has a surface and a back surface located offset from the oscillator and opposite to the surface; and The reflective surface is positioned opposite the back surface of the vibrator, spaced apart. The vibrating body comprises: The connecting part is connected to the oscillator; and The vibrating portion extends from the end of the connecting portion opposite to the oscillator side and extends in a direction away from the reflective surface, having a back surface opposite to the reflective surface. The vibrating part extends from the connecting part towards the surface in a convex arc or elliptical arc shape in longitudinal section, and has a cylindrical shape. Viewed from a direction perpendicular to the reflective surface, the periphery of the reflective surface is coaxial with the central axis of the vibrating part and located outside the vibrating part. If the distance between the connecting portion and the reflective surface in the direction perpendicular to the reflective surface is defined as TD, The aspect ratio of the back side of the vibrating part in the longitudinal section is set as AR. Let L be the shortest distance between the periphery of the back surface and the periphery of the reflective surface at the front end of the vibrating part opposite to the connecting part. Let the wavelength of the vibration wave emitted from the vibrating part be λ, then Within the range of TD = 0 and 0.9 ≤ AR ≤ 3.2, the relationship 0.83λ ≤ L is satisfied.

4. The vibration wave radiation device according to claim 3, wherein, Within the range of TD = 0 and 0.9 ≤ AR ≤ 3.2, the relationship 0.83λ ≤ L ≤ 2λ is satisfied.

5. A vibration wave radiation device, comprising: An oscillator generates vibration; A vibrating body, connected to the oscillator, has a surface and a back surface located offset from the oscillator and opposite to the surface; and The reflective surface is positioned opposite the back surface of the vibrator, spaced apart. The vibrating body comprises: The connecting part is connected to the oscillator; and The vibrating portion extends from the end of the connecting portion opposite to the oscillator side and extends in a direction away from the reflective surface, having a back surface opposite to the reflective surface. The vibrating part extends in a straight line from the connecting part and extends in a cylindrical shape in the longitudinal section. Viewed from a direction perpendicular to the reflective surface, the periphery of the reflective surface is coaxial with the central axis of the vibrating part and located outside the vibrating part. If the distance between the connecting portion and the reflective surface in the direction perpendicular to the reflective surface is defined as TD, In the longitudinal section, the angle between the imaginary line parallel to the reflective surface and the back surface of the vibrating part is defined as θ. Let L be the shortest distance between the periphery of the back surface and the periphery of the reflective surface at the front end of the vibrating part opposite to the connecting part. Let the wavelength of the vibration wave emitted from the vibrating part be λ, then Within the range of θ = 45° and 0.1 ≤ TD ≤ 1.1, the relationship 1.01λ ≤ L ≤ 1.15λ or 1.81λ ≤ L ≤ 1.83λ is satisfied.

6. A vibration wave radiation device, comprising: An oscillator generates vibration; A vibrating body, connected to the oscillator, has a surface and a back surface located offset from the oscillator and opposite to the surface; and The reflective surface is positioned opposite the back surface of the vibrator, spaced apart. The vibrating body comprises: The connecting part is connected to the oscillator; and A pair of vibrating parts, separated from each other at the end of the connecting part opposite to the oscillator side and extending away from the reflective surface, have a back surface opposite to the reflective surface. The pair of vibrating parts are inclined and extend in the longitudinal section such that they are separated from each other from the connecting part and are located in positions that are linearly symmetrical about each other with respect to the central axis. Viewed from a direction perpendicular to the reflective surface, the periphery of the reflective surface is a pair of rectangles that respectively surround the pair of vibrating parts from the outside. If the distance between the connecting portion and the reflective surface in the direction perpendicular to the reflective surface is defined as TD, In the longitudinal section, the angle between the imaginary line parallel to the reflective surface and the back surface of the pair of vibrating parts is defined as θ. In the longitudinal section, the shortest distance between the edge of the back surface at the front end of the pair of vibrating parts opposite to the connecting part side and the edge of the reflective surface opposite to the oscillator side is defined as L. If the wavelength of the vibration wave emitted from the pair of vibrating parts is set as λ, then Within the range of θ = 45° and 1.4 ≤ TD ≤ 1.8, the relationship 0.74λ ≤ L ≤ 1.26λ or 1.54λ ≤ L is satisfied.

7. The vibration wave radiation device according to claim 6, wherein, Within the range of θ = 45° and 1.4 ≤ TD ≤ 1.8, the relationship 0.74λ ≤ L ≤ 1.26λ or 1.54λ ≤ L ≤ 2λ is satisfied.

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