Piezoelectric sounder

Abstract

The present invention provides a piezoelectric sound-generating body. The piezoelectric sound-generating body (10) comprises: a piezoelectric vibration piece (20); a housing (50) in which the piezoelectric vibration piece (20) is housed; a cover-shaped substrate (40) mounted on the housing (50) and forming a housing space for the piezoelectric vibration piece (20) together with the housing (50); and conductive terminals (60, 70) electrically connected to the piezoelectric vibration piece (20). The conductive terminals (60, 70) comprise a front end portion (62, 72) for elastically pressing the piezoelectric vibration piece (20) toward the housing side and a terminal body (68, 78) connected to the front end portion (62, 72). At least a portion of the terminal body (68, 78) is embedded in the cover-shaped substrate (40) and fixed. According to the present invention, the piezoelectric vibration piece in the piezoelectric sound-generating body can be made to vibrate sufficiently.

Description

Technical Field

[0001] The present invention relates to a piezoelectric sound-generating body that generates sound by vibrating a piezoelectric vibrating piece. Background Art

[0002] A piezoelectric sound-generating body generates sound by applying an electrical signal to a piezoelectric vibrating reed housed in a housing, causing the reed to vibrate. In Patent Document 1, terminals for applying electrical signals to the piezoelectric vibrating reed are fixed to the housing, and the periphery of the piezoelectric vibrating reed is bonded to the housing using a silicone adhesive or the like.

[0003] However, in this structure where the terminals are fixed to the housing and the periphery of the piezoelectric vibrating reed is bonded to the housing using a silicone adhesive or the like, there is a problem of excessively restricting the vibration of the piezoelectric vibrating reed, potentially reducing sound pressure and quality. Furthermore, the work involved in bonding the periphery of the piezoelectric vibrating reed is complex.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-23697. Summary of the Invention

[0007] Problems to be solved by the invention

[0008] The present invention has been developed in view of such actual circumstances, and an object of the present invention is to provide a piezoelectric sound-generating body that can be expected to have improved sound pressure and / or sound quality and that can be easily manufactured.

[0009] Technical means to solve the problem

[0010] In order to achieve the above-mentioned object, the piezoelectric sound-generating body of the present invention has:

[0011] Piezoelectric vibrating piece;

[0012] a housing for accommodating the piezoelectric vibrating piece;

[0013] a cover-shaped substrate mounted on the housing and forming a storage space for the piezoelectric vibrating piece together with the housing; and

[0014] a conductive terminal electrically connected to the piezoelectric vibrating piece,

[0015] The conductive terminal includes: a front end portion that elastically presses the piezoelectric vibrating piece toward the housing; and a terminal body connected to the front end portion.

[0016] At least a portion of the terminal body is embedded in the lid-shaped substrate and fixed thereto.

[0017] In the piezoelectric sound-generating device of the present invention, the piezoelectric vibrating reed is elastically pressed by the tip of a conductive terminal partially embedded in a cover-like substrate. When the piezoelectric sound-generating device is mounted on a circuit board, for example, the outer surface of the cover-like substrate on the mounting side is vertically downward. As a result, the piezoelectric vibrating reed is elastically retained against the housing by the tip of the conductive terminal within the housing space. This allows the piezoelectric vibrating reed to be housed within the housing simply by attaching the cover-like substrate to the housing, without the use of adhesives or the like. This significantly simplifies the manufacture of the piezoelectric sound-generating device.

[0018] In addition, in the piezoelectric sound-generating body of the present invention, the periphery of the piezoelectric vibrating piece is not fixed by adhesives or the like. Therefore, when an electrical signal (for example, a periodic voltage signal) is applied to the piezoelectric vibrating piece, the piezoelectric vibrating piece is not restricted by adhesives or the like and can vibrate freely, thereby improving the sound pressure and / or sound quality.

[0019] In addition, the conductive terminal body is partially embedded in the cover-shaped substrate, so the conductive terminal does not wobble and can be stably fixed to the cover-shaped substrate. In addition, the resistance to external impact is enhanced, which also improves the durability of the product.

[0020] The front end portion preferably includes an inclined portion extending from the terminal body toward the outer edge of the lid-shaped substrate and inclined toward the piezoelectric vibrating reed. This inclined portion, tilted toward the piezoelectric vibrating reed, allows the front end portion to elastically press the piezoelectric vibrating reed toward the housing with a constant force, thereby retaining it. As a result, electrical signals can be stably supplied from the conductive terminal to the piezoelectric vibrating reed, and even when the piezoelectric vibrating reed vibrates within the housing, the piezoelectric vibrating reed can be elastically retained within the housing.

[0021] Preferably, the lid substrate includes a through-hole extending from the outside of the lid substrate to the housing space, and the front end portion extends from the lid substrate and is disposed within the through-hole. By disposing the front end portion within the through-hole, after the conductive terminal and the lid substrate are integrally formed, the front end portion can be easily bent toward the housing through the through-hole. Furthermore, after the lid substrate is mounted in the housing, the through-hole allows for easy confirmation of proper connection between the front end portion and the piezoelectric vibrating reed.

[0022] Preferably, the cover-like substrate has a groove portion extending from the through-hole toward the outer edge of the cover-like substrate, connecting the interior of the through-hole with the exterior of the housing. There is a case where the piezoelectric sound-generating body of the present invention is surface-mounted on a circuit board, etc., such that the outer surface of the cover-like substrate faces the surface of the circuit board, etc. In this case, the through-hole of the cover-like substrate is covered by the surface of the circuit board, etc. However, the through-hole is connected to the outside from the outer surface of the side wall of the housing through the groove portion, so that the groove portion and the through-hole serve as an exhaust port to the storage space inside the housing, which helps to improve the sound pressure and / or sound quality of the sound generated by the vibration of the piezoelectric vibrating piece.

[0023] Preferably, the through-holes comprise at least one pair of through-holes that communicate with each other within the housing space. By allowing the through-holes, which function as exhaust ports, to communicate with each other within the housing space, the sound pressure and / or sound quality of the sound generated by the vibration of the piezoelectric vibrating piece are improved. Furthermore, since the through-holes communicate with the exterior from the sidewall of the housing via the respective grooves, the structure facilitates surface mounting of the piezoelectric sounding element.

[0024] The position of the sound-releasing hole connecting from the storage space to the outside of the shell is not particularly limited, but it is preferably formed on the side surface of the outer wall of the shell. By forming the sound-releasing hole on the side surface of the outer wall of the shell, there is no need to provide a sound-releasing hole on the upper surface of the outer wall of the shell. Therefore, by sucking the upper surface of the outer wall of the shell with a suction nozzle, the piezoelectric sound-generating body can be easily picked up and easily installed on a printed circuit board, etc. In addition, after the piezoelectric sound-generating body is installed, a large sound pressure can be obtained even if there is an obstacle above the upper surface of the outer wall of the shell. In addition, by forming the sound-releasing hole on the side surface of the outer wall of the shell, when the piezoelectric sound-generating body is surface-mounted on a circuit board, etc., it is difficult for garbage and the like to enter the interior of the shell, thereby reducing the deterioration of the sound.

[0025] Preferably, the front end portion extends toward the outer wall side surface of the housing opposite to the outer wall side surface in which the sound emission hole is formed. Furthermore, preferably, the outer wall side surface forming the groove portion extending from the through hole serving as the exhaust port is opposite to the outer wall side surface in which the sound emission hole is formed. This configuration contributes to improving the sound pressure and / or sound quality of the sound generated by the vibration of the piezoelectric vibrating reed.

[0026] Preferably, the terminal body has:

[0027] an inner portion connected to the front end portion and substantially parallel to the piezoelectric vibrating piece;

[0028] an outer portion that is substantially parallel to the inner portion and is disposed at a different level than the inner portion; and

[0029] An intermediate portion is located between the inner portion and the outer portion.

[0030] By having such a terminal main body structure, the cover-shaped substrate and the conductive terminal can be easily integrally molded by, for example, insert molding or the like.

[0031] The intermediate portion can be connected to the inner and outer portions in a stepped manner, but is preferably connected at an angle. By tilting the intermediate portion, the inner portion of the terminal body is easily embedded in the center of the thickness of the cover substrate, while the outer portion of the terminal body is easily exposed on the same plane as the outer surface of the cover substrate. Furthermore, by exposing only the outer portion outside the cover substrate, connection to pads on a circuit board is facilitated, facilitating surface mounting.

[0032] Preferably, the inner portion and the middle portion are embedded in the lid substrate, and a portion of the outer portion near the middle portion may also be embedded in the lid substrate. However, preferably, the outer surface of the outer portion is exposed to the outside of the lid substrate. In this case, connection to a pad on a circuit board or the like is facilitated, and surface mounting is facilitated.

[0033] The inner portion preferably has a reinforcement portion for enhancing fixation to the cover-like substrate. The reinforcement portion is preferably a hole, but may also be a concave-convex portion. Providing the reinforcement portion on the inner portion improves the bonding strength between the terminal body and the cover-like substrate when the inner portion and the interior of the cover-like substrate are integrally formed by insert molding or the like.

[0034] Preferably, the inner portion has a heat conduction mitigation portion that mitigates heat conduction to the front end portion. The heat conduction mitigation portion is not particularly limited, and for example, a cutout may be provided near the boundary between the inner portion and the front end portion, or a detour may be provided in the path for heat transfer from the outer portion to the front end portion. By providing the heat conduction mitigation portion in the inner portion, heat generated in the outer portion during installation, etc., is less likely to be transferred to the front end portion. It is important to maintain elasticity (spring characteristics) at the front end portion so that the front end portion presses the piezoelectric vibrating piece toward the housing side with a substantially constant force. In order to prevent the spring characteristics at the front end portion from changing, it is preferable not to transfer high heat to the front end portion.

[0035] Preferably, the conductive terminal includes a retaining portion that extends from the cover-shaped substrate at a position different from the front end and is connected to the outer portion of the terminal body, and the retaining portion engages with the housing. Engaging the retaining portion with the housing improves operability when attaching the cover-shaped substrate to the housing.

[0036] Preferably, the retaining portion includes a bent piece that bends toward the housing, and the bending direction of the bent piece is substantially consistent with the direction in which the front end portion of the conductive terminal elastically presses the piezoelectric vibrating piece. When the piezoelectric sound-generating body of the present invention is surface-mounted on, for example, a circuit board, it can be configured so that the outer surface of the cover-shaped substrate faces the surface of the circuit board. Therefore, a solder fillet is formed on the outer surface of the bent piece that bends toward the housing, which aligns with the pad portion of the circuit board, making it easy to confirm the connection. In addition, the stepped portion of the housing suppresses the piezoelectric vibrating piece, and the connection is made using the elastic pressure of the front end portion of the elastic conductive terminal, thereby ensuring a reliable connection between the front end portion of the conductive terminal and the electrode of the piezoelectric vibrating piece.

[0037] Preferably, the outer periphery of the cover-shaped substrate has at least one engaging protrusion for engaging with the housing, and the housing has at least one engaging recess corresponding to the shape of the engaging protrusion. By so configuring, the cover-shaped substrate can be easily positioned and engaged with the housing.

[0038] Preferably, the lid-shaped substrate has a plurality of outer corners, and the engaging protrusion protruding outward on the same plane as the lid-shaped substrate is formed at at least one of the outer corners. Furthermore, preferably, engaging protrusions are formed at each of the four outer corners of the lid-shaped substrate.

[0039] Preferably, the bottom surface and the side surface of the joint recess are fused together with the joint protrusion. By abutting a heating fixture against the boundary of the joint protrusion and the joint recess from the outer surface of the lid-shaped substrate, the joint recess and the joint protrusion can be easily thermally welded.

[0040] Preferably, the piezoelectric vibrating reed is arranged within the storage space so as to divide the storage space into a first space and a second space, the volume of the first space being larger than the volume of the second space, and the tip of the conductive terminal is arranged within the second space. The first space serves as a primary echo space for sound generated by the vibration of the piezoelectric vibrating reed, and sound of a predetermined frequency is emitted from the sound emission hole. The second space serves as a secondary echo space for sound generated by the vibration of the piezoelectric vibrating reed. The tip of the conductive terminal is arranged in the second space.

[0041] Preferably, the piezoelectric vibrating reed is placed on a stepped portion formed on the inner wall of the housing, dividing the storage space into a first space and a second space. This configuration allows the piezoelectric vibrating reed to be easily attached to the housing with the opening of the housing facing upward during installation. Furthermore, the spaces formed above and below the piezoelectric vibrating reed allow the reed to vibrate fully, facilitating the production of desired sounds.

[0042] Preferably, the cover-shaped substrate includes a stopper protrusion that restricts movement of the piezoelectric vibrating piece toward the conductive terminal. The stopper protrusion may also be formed on the inner surface of the cover-shaped substrate in a manner corresponding to the shape of the outer periphery of the piezoelectric vibrating piece. When surface-mounting the piezoelectric sound-generating body onto a circuit board, etc., the cover-shaped substrate is positioned downwardly to mount the piezoelectric sound-generating body onto the circuit board, etc. However, the piezoelectric vibrating piece may deviate toward the conductive terminal due to its own weight or external impact. The stopper protrusion prevents the piezoelectric vibrating piece from excessively deviating toward the conductive terminal, thereby improving impact resistance. Furthermore, the presence of the stopper protrusion prevents excessive deformation of the front end, facilitating the maintenance of its elasticity.

[0043] The front end portion may also have a substantially hemispherical contact convex portion that contacts the piezoelectric vibrating piece. This allows the contact convex portion to reliably contact the piezoelectric vibrating piece, effectively preventing contact failure. The piezoelectric vibrating piece may also be disc-shaped. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1A This is a schematic perspective view of a piezoelectric sound-generating body according to one embodiment of the present invention.

[0045] Figure 1B This is a schematic perspective view of the piezoelectric sound-generating body in FIG. 1 , which is turned upside down.

[0046] Figure 2A yes Figure 1A The exploded perspective view of the piezoelectric sound generator is shown.

[0047] Figure 2B yes Figure 1B The exploded perspective view of the piezoelectric sound generator is shown.

[0048] Figure 3 Yes Figure 2B A perspective view of the shell portion of the piezoelectric sound generator is shown.

[0049] Figure 4 It is along Figure 2B A cross-sectional view of the lid-shaped substrate of the piezoelectric sound-generating body taken along line IV-IV is shown.

[0050] Figure 5A It is along Figure 2B A cross-sectional view of the housing of the piezoelectric sound-generating body and the piezoelectric vibrating piece taken along line VA-VA is shown.

[0051] Figure 5B It is along Figure 2B A cross-sectional view of the housing of the piezoelectric sound-generating body and the piezoelectric vibrating piece taken along the VB-VB line is shown.

[0052] Figure 5C yes Figure 2BAn enlarged cross-sectional view of the piezoelectric vibrating piece of the piezoelectric sound-generating body shown.

[0053] Explanation of symbols

[0054] 10…Piezoelectric sounder

[0055] 20…Piezoelectric vibrating piece

[0056] 22…Piezoelectric element

[0057] 22a…first electrode

[0058] 22b…second electrode

[0059] 23… Adhesive

[0060] 24…Vibration plate

[0061] 40…lid-shaped substrate

[0062] 41a…External surface of the mounting side

[0063] 41b…Inner surface

[0064] 41c…outer rim

[0065] 42…sound hole

[0066] 43a, 43b...through holes

[0067] 46…joining convex part

[0068] 47a, 47b...groove

[0069] 48…Sound-discharging side convex part

[0070] 49…Stop protrusion

[0071] 50…housing

[0072] 51…Shell step

[0073] 51a ... Step portion outer peripheral wall

[0074] 52…Bottom

[0075] 52a…Inside wall surface

[0076] 53…Side of the outer wall of the shell

[0077] 53a…first recess

[0078] 53b…Second recess

[0079] 54a…Install the opposite side outer surface

[0080] 54b…Outer surface of the mounting side

[0081] 55…Storage space

[0082] 55a…First Space

[0083] 55b…Second Space

[0084] 56…joint recess

[0085] 59a…Universal incision

[0086] 59b…side incision for sound release

[0087] 60, 70...conductive terminals

[0088] 62, 72…front end

[0089] 62a, 72a…Terminal inclined portion

[0090] 62b, 72b...contact convex portion

[0091] 64, 74…maintenance

[0092] 68, 78…Terminal body

[0093] 68a, 78a…Inner part

[0094] 68b, 78b…middle part

[0095] 68c, 78c…outer side

[0096] 68d, 78d…Reinforced hole (reinforced portion)

[0097] 68e, 78e…heat conduction mitigation unit DETAILED DESCRIPTION

[0098] The present invention will be described below based on the embodiments shown in the accompanying drawings. In the accompanying drawings, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the side opposite to the direction of the arrow of the Z-axis is the mounting surface side.

[0099] like Figure 1A and Figure 1B As shown, the piezoelectric sound-generating body 10 according to one embodiment of the present invention includes a piezoelectric vibrating piece 20, a lid-shaped substrate 40, and a case 50. First, the piezoelectric vibrating piece 20 will be described.

[0100] (Piezoelectric Vibration Plate)

[0101] like Figure 2A and Figure 2B As shown in FIG. 1 , the piezoelectric vibrating piece 20 includes a flat vibrating piece 24. A flat piezoelectric element 22 having an outer diameter smaller than that of the vibrating piece 24 is fixed to one surface of the vibrating piece 24 along the Z axis. Figure 5C As shown, a first electrode 22a and a second electrode 22b are formed on the surface and the back of the piezoelectric element 22, respectively. Figure 2B As shown, the first electrode 22a has an outer diameter slightly smaller than that of the piezoelectric element 22 and is formed in a film shape so as to cover the center portion of the surface of the piezoelectric element 22. Figure 2B Although not visible in the figure, a second electrode 22a is formed on the back of the piezoelectric element 22 in the same manner as the first electrode 22a. Figure 5C The second electrode 22b is shown.

[0102] like Figure 5C As shown, the back surface of the piezoelectric element 22 is bonded to the surface of the vibrating piece 24, for example, using an adhesive 23. The adhesive 23 can also penetrate between the second electrode 22b and the piezoelectric element 24, ensuring electrical continuity between the second electrode 22b and the vibrating piece 24. Furthermore, the adhesive 23 can also be a conductive adhesive. Alternatively, the piezoelectric vibrating piece 20 can be formed by directly stacking the second electrode 22b, the piezoelectric element 22, and the first electrode 22a on the vibrating piece 24 in this order, using a thin film method or other method.

[0103] Furthermore, the piezoelectric element 22 need not necessarily be provided with the second electrode 22b; it is sufficient as long as the back surface of the piezoelectric element 22 is directly or indirectly electrically connected to the vibrating plate 24. The vibrating plate 24 may be connected to the back surface of the piezoelectric element 22 via the second electrode 22b, or it may be connected to the back surface of the piezoelectric element 22 without the second electrode 22b. In either case, the vibrating plate 24 functions as the electrode on the other side of the piezoelectric element 22 that forms a pair with the first electrode 22a.

[0104] The vibrating piece 24 is insulated from the first electrode 22a. A voltage is applied as an electrical signal to the piezoelectric element 22 via the vibrating piece 24 and the first electrode 22a, causing the piezoelectric element 22 to expand and contract at a predetermined frequency. As the piezoelectric element 22 expands and contracts, the vibrating piece 20 vibrates in the Z-axis direction, generating sound.

[0105] The material of the piezoelectric element 22 is not particularly limited as long as it is a piezoelectric material, but may be composed of, for example, ferroelectric ceramics such as PZT (lead zirconate titanate) and PT (lead titanate), or crystal. The material of the vibrating piece 24 is also not particularly limited, but may be made of, for example, metal materials such as brass, Ni alloy, and stainless steel. The first electrode 22a and the second electrode 22b may be composed of, for example, a sintered electrode film of Ag paste, but are not limited to this.

[0106] The shapes of the vibration piece 24 and the piezoelectric element 22 are not particularly limited, but they usually have a concentric circular structure on the XY plane. On the XY plane, the piezoelectric element 22 is located approximately in the center of the vibration piece 24. The outer diameter of the vibration piece 24 is not particularly limited, but it is usually about 6 to 20 mm. In addition, the thickness of the vibration piece 24 (thickness in the Z direction) is not particularly limited, but it is usually about 30 to 150 μm. The outer diameter of the piezoelectric element 22 is not particularly limited, but it is usually about 4 to 18 mm. In addition, the thickness of the piezoelectric element 22 (thickness in the Z direction) is not particularly limited, but it is usually about 30 to 150 μm. The thickness of the electrodes 22a and 22b (thickness in the Z direction) is not particularly limited, but it is usually about 5 to 15 μm.

[0107] (Casing and Cover Substrate)

[0108] Next, the housing 50 and the cover substrate 40 will be described. First, the housing 50 will be described. Figure 3 As shown, the housing 50 has a substantially rectangular box shape with a predetermined height H. Figure 5B As shown, the installation opposite side outer surface 54a of the housing 50 has a substantially flat outer surface without large grooves or recesses, etc. In addition, some grooves and concave-convex portions, etc. may also be formed on the installation opposite side outer surface 54a, but a through hole penetrating the surface back side is preferably not formed.

[0109] The height H0 of the housing 50 is Figure 1A The thickness of the piezoelectric sound-generating body 10 shown is generally uniform, preferably about 2.8 to 3.0 mm. Figure 3 The X-axis length and Y-axis length of the housing 50 shown are also the same as Figure 1A The lengths of the piezoelectric sound-generating body 10 shown are approximately the same, and are preferably approximately 11.8 to 12.2 mm.

[0110] like Figure 3 As shown in FIG. 5 , a substantially cylindrical storage space 55 is formed in the center of the XY plane of the mounting side outer surface 54 b of the housing 50 . Figure 5B As shown, the depth H1 from the mounting side outer surface 54b to the bottom surface 52 of the storage space 55 is smaller than the height H0 of the shell 50, and is determined to be able to fully ensure the thickness of the shell 50 from the bottom surface 52 to the mounting opposite side outer surface 54a of the shell 50 in terms of strength.

[0111] like Figure 3 As shown, the inner wall surface 52a of the housing 50 is formed with a groove for placing the sound source in the circumferential direction of the storage space 55, except for the sound-emitting side cutout 59b described later. Figure 5A The outer periphery of the piezoelectric vibrating piece 20 is formed by a housing step 51. Figure 3 (exist Figure 1B 、 Figure 2B 、 Figure 5A and Figure 5B Similarly, in FIG5 , the outer surface 54 a of the housing 50 on the opposite side of the mounting side is arranged to face vertically downward along the Z axis.

[0112] like Figure 5B As shown, the housing step 51 is located at a position that is a predetermined height h0 higher than the bottom surface 52 and is parallel to the bottom surface 52. The piezoelectric vibrating reed 20 is mounted on the housing step 51, with the vibrating reed 24 disposed on the housing step 51. A step outer peripheral wall 51a is formed around the housing step 51 to surround the piezoelectric vibrating reed 20. By arranging the outer peripheral edge of the piezoelectric vibrating reed on the housing step 51, the housing space 55 of the housing 50 is divided into a first space 55a located near the bottom surface 52 and a second space 55b located near the mounting side outer surface 54b.

[0113] Furthermore, the predetermined height h0 of the step portion 51 is preferably greater than half the depth H1 of the bottom surface 52 of the storage space 55, and h0 / H1 is preferably between 0.5 and 0.8. By setting this numerical range, the volume of the first space 55a of the storage space 55, which is defined by the diaphragm 20, can be made sufficiently larger than the volume of the second space 55b. As a result, the sound pressure and / or sound quality of the piezoelectric sound-generating body 10 can be improved.

[0114] In addition, if Figure 3 As shown, first recesses 53a, 53a are formed on both sides of the mounting side outer surface 54b of the housing 50 along the Z axis, which is opposite to the mounting side outer surface 54a. The depth of these recesses 53a, 53a along the Z axis is preferably Figure 2B The thickness of the outer portions 68c and 78c of the conductive terminals 60 and 70, described later, is shown. Furthermore, recesses 53b and 53b corresponding to these recesses 53a and 53a are formed on the outer side of the housing 50. The retaining portions 64 and 74 of the conductive terminals 60 and 70 can engage with these recesses 53b and 53b. The depth of these recesses 53b and 53b along the Y-axis is approximately the same as the depth of the recesses 53a and 53a along the Z-axis.

[0115] like Figure 3 As shown, a communication cutout 59a and a sound-discharging cutout 59b are formed on both sides of the mounting side outer surface 54b of the housing 50 along the X axis. The width of the communication cutout 59a along the Y axis is such that the width of the sound-discharging cutout 59b formed on the mounting side outer surface 54b is such that the width of the sound-discharging cutout 59a is such that the width of the sound-discharging cutout Figure 2B The width of the pair of grooves 47a and 47b on the mounting side outer surface 41a of the cover substrate 40 shown in FIG. The depth of the connecting cutout 59a along the Z axis is the same as the depth of the pair of grooves 47a and 47b along the Z axis. In the assembled state (refer to FIG. Figure 1B ), the bottom surface of the connecting cutout 59a and the bottom surfaces of the grooves 47a and 47b are in the same plane.

[0116] like Figure 5B As shown, the bottom surface of the sound-emitting-side cutout 59b is located a predetermined height h1 lower than the housing step 51 along the Z-axis. Therefore, in this embodiment, a sound-emitting hole 42 is formed on the side of the piezoelectric sound-generating body 10, specifically, at the center of the housing outer wall side surface 53 along the X-axis in the Y-axis direction. This hole communicates primarily with the first space 55a of the housing 55 from the outside of the housing 50. The height h1 of the sound-emitting hole 42 communicating with the first space 55a is preferably smaller than the height h0 of the step, but h0 = h1 may be sufficient depending on the nature of the sound being produced.

[0117] Sound hole 42 Figure 1B As shown, the sound-emitting side protrusion 48 of the cover substrate 40 is fitted into the sound-emitting side cutout 59b of the housing 50. The width of the sound-emitting side cutout 59b in the Y-axis direction is preferably slightly larger than the width of the sound-emitting side protrusion 48 in the Y-axis direction. Figure 5B The height h3 of the sound emitting hole 42 shown is determined by the content of the sound to be generated by the piezoelectric sound generating body 10 .

[0118] The content of sound refers to the sound pressure and quality of the sound, and also includes the pitch and / or frequency of the sound. Factors that determine the content of the sound regarding the sound emission hole 42 include, among other factors, the width w1 in the X-axis direction from the housing outer wall side surface 53 to the stepped portion outer peripheral wall 51a, and the width w2 in the X-axis direction of the housing stepped portion 51.

[0119] The height h3 of the sound hole is as follows Figure 5B As shown, it can be defined as the height from the bottom surface of the notch 59b in the Z-axis direction to the bottom surface of the engagement recess 56 in the Z-axis direction. The height h3 of the sound emission hole can be defined as the height obtained by adding the height h1 of the sound emission hole 42 communicating with the first space 55a to the height h2 of the sound emission hole 42 capable of communicating with the second space 55b.

[0120] Engagement recess 56 such as Figure 2B As shown, in this embodiment, the four corners of the mounting-side outer surface 54b of the housing 50 are formed so as to extend outward in a convex shape from the stepped outer peripheral wall 51a. The depth of the bottom surface of each engaging recess 56 along the Z axis is preferably equal to the thickness (along the Z axis) of the lid-like substrate 40, that is, the same as the thickness (along the Z axis) of the engaging protrusions 46 formed at the four corners of the lid-like substrate 40. However, the depth may be slightly smaller or larger than the thickness of the engaging protrusions 46.

[0121] However, the depth of the bottom surface of each engaging recess 56 along the Z axis is determined so that Figure 4 The inner surface 41b of the cover substrate 40 is not shown. Figure 2B The electrodes 22a of the piezoelectric element 22 are shown in contact. Figure 4 The outer periphery of the inner surface 41b of the cover-shaped substrate 40 shown in the figure is provided with a stopper protrusion 49 protruding from the opposite side along the Z-axis. Figure 2B The piezoelectric vibrating piece 20 may move in the Z-axis direction as shown, and may also come into contact with the vibrating piece 24 .

[0122] In addition, the depth of the bottom surface of each engaging recess 56 along the Z axis is determined to ensure that it can be aligned with the bottom surface of the engaging recess 56. Figure 5B The height h2 of the sound emitting hole 42 that can communicate with the second space 55b is the same as the height h2 of the sound emitting hole 42 that can communicate with the second space 55b. Figure 4 The heights of the second spaces 55b corresponding to the gaps between the inner surfaces 41b of the lid substrate 40 shown in the figure in the Z-axis direction are consistent.

[0123] In the present embodiment, the housing 50 is made of a thermoplastic resin such as a liquid crystal polymer resin, a polybutylene terephthalate resin, a polyphenylene sulfide resin, a polyetheretherketone resin, or a fluororesin.

[0124] The cover substrate 40, described later, may be made of the same material as the housing 50, or may be made of a different material. In this embodiment, since the cover substrate 40 and the conductive terminals 60, 70, etc., such as metal terminals, are insert-molded, the cover substrate 40 is preferably made of a thermoplastic resin that is easily insert-molded.

[0125] Next, the lid-shaped substrate 40 will be mainly described. Figure 2B As shown, the cover-shaped substrate 40 is composed of a generally square flat plate having a thickness approximately corresponding to the depth of the bonding recess 56 formed in the housing 50. The four corners of the substrate 40 are integrally formed with the substrate 40 with bonding protrusions 46 having a planar shape corresponding to the planar shape of the bonding recess 56 (a plane parallel to the X-axis-Y-axis plane).

[0126] Furthermore, a sound-emitting protrusion 48 is formed on the outer edge of the lid-shaped base plate 40 so as to protrude along the X-axis at a position corresponding to the sound-emitting notch 59b formed in the housing 50. As previously described, the sound-emitting protrusion 48 engages with the opening of the sound-emitting notch 59b and, together with the sound-emitting notch 59b, forms the sound-emitting hole 42.

[0127] The mounting-side outer surface 41a of the lid-shaped substrate 40, including the engagement protrusion 46 and the sound-emitting protrusion 48, is flat. However, through-holes 43a and 43b are formed on the mounting-side outer surface 41a, located opposite the sound-emitting protrusion 48 along the X-axis. These through-holes 43a and 43b are offset from each other along the X-axis and the Y-axis. These through-holes 43a and 43b extend from the mounting-side outer surface 41a to the inner surface 41b. Furthermore, grooves 47a and 47b are formed on the mounting-side outer surface 41a, extending along the X-axis from the through-holes 43a and 43b toward the outer edge 41c of the lid-shaped substrate.

[0128] The through-hole 43a on one side and the groove 47a on the other side have the same width in the Y-axis direction and are arranged in a straight line along the X-axis. The through-hole 43a connects from the mounting-side outer surface 41a to the inner surface 41b, but the groove 47a is a stepped portion recessed at a predetermined depth along the Z-axis from the mounting-side outer surface 41a, and does not penetrate the front or back surface. Similarly, the through-hole 43b and the groove 47b on the other side have the same width in the Y-axis direction and are arranged in a straight line along the X-axis. The through-hole 43b connects from the mounting-side outer surface 41a to the inner surface 41b, but the groove 47b is a stepped portion recessed at a predetermined depth along the Z-axis from the mounting-side outer surface 41a, and does not penetrate the front or back surface.

[0129] The through-holes 43a and 43b have approximately the same width in the Y-axis direction, and their opening areas are preferably also approximately the same, but may differ. One through-hole 43a is located closer to the center of the substrate 40 along the X-axis than the through-hole 43b. The tip 62 of the conductive terminal 60 disposed within the through-hole 43a contacts and electrically connects to the first electrode 22a of the piezoelectric vibrating piece 20. The other through-hole 43b is located closer to the outer edge 41c of the substrate 40 along the X-axis than the through-hole 43a. The tip 72 of the conductive terminal 70 disposed within the through-hole 43b contacts and electrically connects to the vibrating piece 24 of the piezoelectric vibrating piece 20.

[0130] A sound-emitting-side protrusion 48 is provided between through-holes 43a and 43b along the Y-axis. The groove depths of grooves 47a and 47b are preferably the same, but may be different. Furthermore, since through-holes 43a and 43b are positioned differently along the X-axis, the lengths of grooves 47a and 47b along the X-axis are naturally different.

[0131] These grooves 43a and 43b are preferably provided, but at least one (or both) of them may be absent. Furthermore, at least one (or both) of these grooves 43a and 43b may be a through-hole continuous with the corresponding through-hole 43a or 43b. As previously described, these grooves 43a and 43b are connected to the communication notch 59a formed in the housing 50.

[0132] like Figure 2A and Figure 4 As shown, a circular stopper protrusion 49 is formed on the inner surface 41b near the outer periphery of the lid-shaped substrate 40, protruding along the Z axis. The tip of the stopper protrusion 49 along the Z axis is preferably rounded and tapered, so that it can contact the surface near the outer periphery of the piezoelectric vibrating piece 20 in the assembled state.

[0133] like Figure 4 As shown, a portion of conductive terminals 60 and 70 is embedded in the cover-shaped substrate 40. Conductive terminals 60 and 70 are formed from a conductive material, such as stainless steel, phosphor bronze, or a Ni alloy. In particular, a plated film may be formed on the surface of the conductive terminals 60 and 70 exposed from the substrate 40 to improve bonding properties with solder, etc. The plated film may have a base metal such as Ni, Cu, or Cr, and a surface metal such as Sn, Au, or Cu. Of course, a plated film may also be formed on the surface of the conductive terminals 60 and 70 embedded within the substrate.

[0134] Each conductive terminal 60, 70 comprises a terminal body 68, 78, a front end portion 62, 72, and a retaining portion 64, 74, respectively, formed by bending a continuous conductive sheet. Each terminal body 68, 78 comprises a continuous inner portion 68a, 78a, an intermediate portion 68b, 78b, and an outer portion 68c, 78c, respectively. The inner portion 68a, 78a and the outer portion 68c, 78c are arranged parallel to the X-Y axis plane and at different height differences.

[0135] Each intermediate portion 68c, 78c is inclined relative to the respective inner portions 68a, 78a and outer portions 68c, 78c. The outer ends of the inner portions 68a, 78a and the inner ends of the outer portions 68c, 78c are connected by intermediate portions 68b, 78b. The inner portions 68a, 78a are embedded in the center of the thickness direction of the lid substrate 40, while the intermediate portions 68b, 78b are embedded in the lid substrate 40 at an angle, thereby stably securing the conductive terminals 60, 70 to the lid substrate 40. Furthermore, the outer surfaces of the outer portions 68c, 78c are flush with the mounting side outer surface 41a.

[0136] like Figure 2A and Figure 2B As shown, reinforcement holes 68d and 78d are formed in the inner portions 68a and 78a. Furthermore, a cutout is formed in the inner portions 68a and 78a near the boundary between the inner portions 68a and 78a and the front end portions 62 and 72. The cutout narrows the width of the inner portions 68a and 78a along the X-axis, thereby narrowing the heat conduction path and forming heat conduction mitigation portions 68e and 78e in the inner portions 68a and 78a.

[0137] In addition, the outer portions 68c and 78c protrude outward from the edge of the substrate 40 along the Y axis, and the holding portions 64 and 74 are formed on the outer sides of the outer portions 68c and 78c, and are bent along the Z axis toward the housing 50. A gap is formed between the holding portions 64 and 74 and the outer peripheral surface of the substrate 40, and a member corresponding to the substrate 40 is inserted into the gap. Figure 2B The step portion outer peripheral wall 51a shown corresponds to the first recess 53a and the second recess 53b formed in the housing 50. As a result, the holding portions 64 and 74 are engaged with the second recess 53b of the housing 50, respectively.

[0138] Near the inner ends of the inner portions 68a and 78a along the Y axis, the respective tip portions 62 and 72 are integrally connected so as to extend outward along the X axis (into the respective through-holes 43a and 43b) from the substrate 40. The tip portions 62 and 72 extend from the inner side surfaces of the through-holes 43a and 43b, which are approximately perpendicular to the X axis, toward the outer edge 41c of the substrate 40 where the grooves 47a and 47b are formed.

[0139] The front end portions 62 and 72 each have a terminal inclined portion 62a or 72a that is inclined from the inner side surface of the through-holes 43a or 43b, which is approximately perpendicular to the X-axis, toward the piezoelectric vibrating piece 20. Each terminal inclined portion 62a or 72a can be formed by bending the front end portion 62 or 72 within the through-holes 43a or 43b toward the piezoelectric vibrating piece 20 after insert molding the conductive terminals 60 or 70 with the substrate 40. A contact protrusion 62b or 72b that protrudes in a substantially hemispherical shape toward the piezoelectric vibrating piece 20 may also be formed at the front end of the front end portion 62 or 72.

[0140] like Figure 4 As shown, the front end of one end portion 72 is preferably bent and tilted more strongly in the direction away from the inner surface 41b than the front end of the other end portion 62. This is to allow the front end portion 72 to press and contact the inner surface 41b with elastic force. Figure 5C The tip portion 62 and 72 are pressed against the surface of the vibrating piece 24 of the piezoelectric vibrating piece 20 by elastic force and brought into contact with the surface of the first electrode 22a of the piezoelectric vibrating piece 20. In this way, the tip portions 62 and 72 are electrically connected to the piezoelectric vibrating piece 20.

[0141] (Regarding the manufacturing method)

[0142] The lid substrate 40, the housing 50, and the piezoelectric vibrating piece 20 are assembled, for example, as follows. Figure 5A As shown, when the outer surface 54a of the housing 50 on the opposite side of the housing 50 faces vertically downward (in the direction of the arrow on the Z axis) and the opening of the storage space 55 of the housing 50 faces upward (in the opposite direction of the arrow on the Z axis), the piezoelectric vibrating piece 20 is installed inside the housing 50. Specifically, Figure 2BAs shown, first, the piezoelectric vibrating piece 20 is placed on the case step portion 51 with the piezoelectric element 22 facing upward.

[0143] Then, if Figure 1B As shown, substrate 40 is mounted in housing 50. At this point, sound-emitting-side protrusion 48 engages with the upper portion of sound-emitting-side notch 59b, and each engaging protrusion 46 engages with each engaging recess. Furthermore, at this point, since the retaining portions 64 and 74 of conductive terminals 60 and 70 have been previously bent along the Z-axis, each retaining portion 64 and 74 engages with the second recess 53b of housing 50 simultaneously with the mounting of substrate 40 in housing 50.

[0144] In addition, before the substrate 40 is installed in the shell 50, the retaining portions 64, 74 of the conductive terminals 60, 70 do not need to be bent along the Z-axis in advance. After the substrate 40 is installed in the shell 50, the retaining portions 64, 74 of the conductive terminals 60, 70 can be bent approximately perpendicularly along the Z-axis relative to the horizontal outer portions 68c, 78c, so as to be engaged with the second recess 53b of the shell 50 by riveting.

[0145] At this time, the lid-shaped substrate 40 is pressed toward the housing 50 so that the tip of the tip portion 72 contacts the vibrating piece 24 of the piezoelectric vibrating piece 20, and the tip of the tip portion 62 contacts the first electrode 22a. Thus, even if the piezoelectric vibrating piece 20 is not fixed to the housing 50 using adhesive or the like, the tip portions 62, 72 of the conductive terminals 60, 70 elastically press the piezoelectric vibrating piece 20 toward the housing 50, thereby being sandwiched and held between the housing 50 and the tip portions 62, 72. Furthermore, whether the tip portions 62, 72 are in contact with the correct position can be confirmed through the through-holes 43a, 43b.

[0146] Therefore, with the lid substrate 40 and the case 50 properly held, the joint recess 56 and the joint projection 46 partially in contact therewith are welded and fixed together using ultrasonic waves or the like, thereby manufacturing the piezoelectric sound-generating body 10 .

[0147] (Summary of Implementation Methods)

[0148] like Figure 1B As shown, in the piezoelectric sound-generating body 10 of this embodiment, the piezoelectric vibrating piece 20 is elastically pressed toward the housing 50 by the front ends 62, 72 of the conductive terminals 60, 70 integrally formed and partially embedded in the lid-like substrate 40, thereby being electrically connected to the front ends 62, 72. When the piezoelectric sound-generating body 10 is mounted on a circuit board, etc., as shown in FIG. Figure 1A As shown, the mounting side outer surface 41a of the lid substrate 40 is positioned vertically downward.

[0149] As a result, the piezoelectric vibrating piece 20 is located in the housing space 55 (see FIG. 1 ) formed inside the case 50 to which the lid-shaped substrate 40 is attached. Figure 3 and Figure 5A ) and is elastically held by the front ends 62 and 72 of the conductive terminals 60 and 70. Therefore, the piezoelectric vibrating reed 20 can be housed inside the housing 50 simply by attaching the lid-shaped substrate 40 to the housing 50 without using an adhesive or the like, significantly facilitating the manufacture of the piezoelectric sound-generating body 10.

[0150] Furthermore, in the piezoelectric sound-generating body 10 of this embodiment, since the periphery of the piezoelectric vibrating piece 20 is not fixed by adhesive or the like, when a periodic voltage signal is applied to the piezoelectric vibrating piece 20 from the conductive terminals 60 and 70, the piezoelectric vibrating piece 20 can vibrate freely without being restricted by adhesive or the like, thereby improving the sound pressure and / or sound quality.

[0151] Furthermore, since the terminal bodies of the conductive terminals 60 and 70 are partially embedded in the lid-like substrate 40, the conductive terminals 60 and 70 do not wobble and are stably fixed to the lid-like substrate 40. Furthermore, the piezoelectric sound-generating body 10 is more resistant to external impacts, thereby improving the durability of the product.

[0152] In addition, if Figure 1B As shown, the front end portions 62 and 72 have inclined portions 62 a and 72 a that extend from the terminal bodies 68 and 78 toward the outer edge of the lid-shaped substrate 40 and are inclined toward the piezoelectric vibrating piece 20. The inclined portions 62 a and 72 a that are inclined toward the piezoelectric vibrating piece 20 allow the front end portions 62 and 72 to elastically press the piezoelectric vibrating piece 20 toward the housing 50 with a constant force and thereby retain it. As a result, electrical signals can be stably supplied from the conductive terminals 60 and 70 to the piezoelectric vibrating piece 20, and even when the piezoelectric vibrating piece 20 vibrates within the housing 50, the piezoelectric vibrating piece 20 can be elastically retained within the housing 50.

[0153] Furthermore, the lid substrate 40 has through-holes 43a and 43b that connect from the outside of the lid substrate 40 to the housing space 55. Tips 62 and 72 extend from the lid substrate 20 into the through-holes 43a and 43b and are disposed within these holes. By disposing the tips 62 and 72 within the through-holes 43a and 43b, after the conductive terminals 60 and 70 are integrally molded with the lid substrate 40, the tips 62 and 72 can be easily bent away from the inner surface 41b of the substrate 40 through the through-holes 43a and 43b. Furthermore, after the lid substrate 40 is mounted on the housing 50, proper connection between the tips 62 and 72 and the piezoelectric vibrating reed 20 can be easily confirmed through the through-holes 43a and 43b.

[0154] In addition, if Figure 1BAs shown, the lid substrate 40 has grooves 47a and 47b extending from through-holes 43a and 43b toward the outer edge of the lid substrate 40, connecting the interiors of the through-holes 43a and 43b with the exterior of the housing 50. The piezoelectric sound-generating body 10 may be surface-mounted on a circuit board (not shown), for example, with the mounting-side outer surface of the lid substrate 40 facing the surface of the circuit board. In this case, the through-holes 43a and 43b of the lid substrate 40 are covered by the surface of the circuit board. However, the through-holes 43a and 43b communicate with the exterior from the outer wall 53 of the housing 50 via the grooves 47a and 47b and the cutout 59a. Therefore, the grooves 47a and 47b and the through-holes 43a and 43b serve as exhaust ports to the housing space 55 within the housing 50, contributing to improvements in the sound pressure and / or sound quality of the sound caused by the vibration of the piezoelectric vibrating reed 20.

[0155] Furthermore, in this embodiment, the through hole is composed of a pair of through holes 43a and 43b. Figure 5B The interior of the second space 55b within the housing space 55 shown is connected. By connecting the through-holes 43a and 43b, which function as exhaust vents, within the housing space, this helps improve the sound pressure and / or sound quality of the sound produced by the vibration of the piezoelectric vibrating piece. Furthermore, since the through-holes 43a and 43b communicate with the exterior from the outer wall side surface 53 of the housing 50 via the grooves 47a and 47b and the cutout 59a, the piezoelectric sound-generating body 10 can be easily surface-mounted.

[0156] Furthermore, in this embodiment, the sound emission hole 42, which connects the housing space 55 to the exterior of the housing 50, can be oriented outward along the Z axis. However, this orientation may be directed outward along the X axis (or outward along the Y axis). Specifically, the sound emission hole 42 is formed on the outer side surface 53 of the housing. Forming the sound emission hole 42 on the outer side surface 53 of the housing 50 eliminates the need for providing a sound emission hole 42 on the outer upper surface 54a of the housing 50. Therefore, by suctioning the outer upper surface 54a of the housing 50 with a nozzle, the piezoelectric sound generator 10 can be easily picked up and easily mounted on a printed circuit board, etc. Furthermore, after mounting the piezoelectric sound generator 10, high sound pressure can be achieved even if there are obstacles above the outer upper surface 54a of the housing 50. Furthermore, forming the sound emission hole 42 on the outer side surface 53 of the housing 50 makes it difficult for debris, etc., to enter the housing 50 through the sound emission hole 42 when the piezoelectric sound generator 10 is surface-mounted on a circuit board, etc., minimizing sound degradation.

[0157] In addition, in this embodiment, Figure 1BAs shown, the front end portions 62 and 72 extend toward the outer wall side surface 53 of the housing 50 opposite to the outer wall side surface 53 where the sound emission hole 42 is formed. Furthermore, the location on the outer wall side surface 53 where the notch 59a communicating with the grooves 47a and 47b from the through-holes 43a and 43b serving as the exhaust port is located opposite to the location on the outer wall side surface 53 where the sound emission hole 42 is formed. This configuration contributes to improving the sound pressure and / or sound quality of the sound generated by the vibration of the piezoelectric vibrating reed.

[0158] In addition, in this embodiment, Figure 4 As shown, the terminal bodies 68 and 78 include inner portions 68a and 78a, outer portions 68c and 78c that are substantially parallel to the inner portions 68a and 78a and are positioned at a different level than the inner portions 68a and 78a, and intermediate portions 68b and 78b located between the inner portions 68a and 78a and the outer portions 68c and 78c. This structure of the terminal bodies 68 and 78 facilitates the integral molding of the cover substrate 40 and the conductive terminals 60 and 70, for example, by insert molding.

[0159] Furthermore, the intermediate portions 68b and 78b can be connected in a stepped manner relative to the inner portions 68a and 78a and the outer portions 68c and 78c, respectively, but are preferably connected at an angle. By tilting the intermediate portions 68b and 78b, the inner portions 68a and 78a of the terminal bodies 68 and 78 are more easily embedded in the center of the thickness direction of the lid substrate 40, while the outer portions 68c and 78c of the terminal bodies 68 and 78 are more easily exposed on the same plane as the mounting-side outer surface 41a of the lid substrate 40. Furthermore, by exposing only the outer portions 68c and 78c of the terminal bodies 68 and 78 outside the lid substrate 40, connection to pads on a circuit board and the like are facilitated, facilitating surface mounting.

[0160] The inner portions 68a, 78a and the middle portions 68b, 78b are embedded in the lid substrate 40, and a portion of the outer portions 68c, 78c near the middle portions 68b, 78b may also be embedded in the lid substrate 40. However, it is preferred that the outer surfaces of the outer portions 68c, 78c be exposed to the outside, approximately flush with the mounting-side outer surface 41a of the lid substrate 40 (or slightly protruding from the outer surface 41a in the Z-axis direction). In this case, connection to pads on a circuit board and the like are facilitated, making surface mounting easier.

[0161] In addition, in this embodiment, the inner side portions 68a and 78a are as follows Figure 1BThe terminal bodies 68 and 78 are shown as reinforcement holes 68d and 78d that serve as reinforcements for securing the terminal bodies 68 and 78 to the lid substrate 40. By providing the reinforcement holes 68d and 78d in the inner portions 68a and 78a, the bonding strength between the terminal bodies 68 and 78 and the lid substrate 40 can be improved when the inner portions 68a and 78a are integrally formed with the interior of the lid substrate 40 by insert molding or the like.

[0162] In this embodiment, the inner portions 68a and 78a include heat-reducing portions 68e and 78e that reduce heat conduction to the front end portions 62 and 72. The heat-reducing portions 68e and 78e may be formed, for example, by providing a cutout near the boundary between the inner portions 68a and 78a and the front end portions 62 and 72, or by providing a detour in the heat transfer path from the outer portions 68c and 78c to the front end portions 62 and 72.

[0163] Providing the heat-conduction mitigating portions 68e and 78e on the inner portions 68 and 78 prevents heat generated on the outer portions 68c and 78c during installation from being transferred to the front end portions 62 and 72. Maintaining the elasticity (spring characteristics) of the front end portions 62 and 72 is important so that the front end portions 62 and 72 press the piezoelectric vibrating piece 20 against the step 51 of the housing 50 with a substantially constant force. To prevent changes in the spring characteristics of the front end portions 62 and 72, it is preferable to prevent high heat from being transferred to the front end portions 62 and 72.

[0164] In this embodiment, the conductive terminals 60 and 70 have retaining portions 64 and 74 that extend from the cover substrate 40 at a position different from the front end portions 62 and 72 and are connected to the outer portions 68c and 78c of the terminal bodies 68 and 78. The retaining portions 64 and 74 engage with the recessed portions 53b and 53b of the housing 50. The engagement of the retaining portions 64 and 74 with the recessed portions 53b and 53b of the housing 50 improves the operability when attaching the cover substrate 40 to the housing 50.

[0165] The retaining portions 64 and 74 have bent tabs that are bent toward the housing 50. The bent direction of the bent tabs generally coincides with the direction in which the front ends 62 and 72 of the conductive terminals 60 and 70 elastically press the piezoelectric vibrating reed 20. When the piezoelectric sound-generating body 20 is surface-mounted on, for example, a circuit board, the mounting-side outer surface 41a of the lid-shaped substrate 40 can be positioned so as to face the surface of the circuit board.

[0166] Therefore, solder fillets are formed on the outer surfaces of the retaining portions 64 and 74, which are bent tabs toward the housing 50, to facilitate connection verification. Furthermore, the stepped portion 51 of the housing 50 restrains the piezoelectric vibrating reed 20, allowing connection to be achieved through the elastic pressure of the front ends 62 and 72 of the resilient conductive terminals 60 and 70. This ensures reliable connection between the front ends 62 and 72 of the resilient conductive terminals 60 and 70 and the electrodes 22a and vibrating reed 24 of the piezoelectric vibrating reed 20. Furthermore, during installation, the piezoelectric vibrating reed 20 is placed on the conductive terminals 60 and 70, and the weight of the piezoelectric vibrating reed 20 also acts on the conductive terminals 60 and 70, ensuring a more reliable connection between the conductive terminals 60 and 70 and the piezoelectric vibrating reed 20.

[0167] like Figure 1B As shown, in this embodiment, the lid-like substrate 40 has at least one engaging protrusion 46 on its outer periphery for engaging with the housing 50, and the housing 50 has at least one engaging recess 56 corresponding in shape to the engaging protrusion 46. This configuration allows the lid-like substrate 40 to be easily positioned and engaged with the housing 50.

[0168] Furthermore, in this embodiment, the lid substrate 40 has a plurality of outer corners, and a bonding protrusion 46 that protrudes outward on the same plane as the lid substrate 40 is formed at at least one of the outer corners. Furthermore, in this embodiment, bonding protrusions 46 are formed at each of the four outer corners of the lid substrate 40.

[0169] like Figure 2B As shown, in this embodiment, the bottom and side surfaces of the joining recess 56 are welded to the joining protrusion 46, but it is sufficient that at least the side surfaces of the joining recess 56 are welded to the joining protrusion 46. For example, by applying a heating jig from the mounting side outer surface 41a of the lid-shaped substrate 40 to the vicinity of the boundary between the joining protrusion 46 and the joining recess 56, the joining recess 56 and the joining protrusion 46 can be easily thermally welded.

[0170] like Figure 5A As shown, the piezoelectric vibrating reed 20 is arranged within the storage space 55 so as to divide the storage space 55 into a first space 55a and a second space 55b. In this embodiment, the volume of the first space 55a is larger than that of the second space 55b, and the tip portions 62 and 72 of the conductive terminals 60 and 70 are arranged within the second space 55b. The first space 55a serves as the primary echo space for sound generated by the vibration of the piezoelectric vibrating reed 20, emitting sound of a predetermined frequency from the sound emission hole 42. The second space 55b serves as the secondary echo space for sound generated by the vibration of the piezoelectric vibrating reed 20. The tip portions 62 and 72 of the conductive terminals 60 and 70 are arranged in the second space 55b.

[0171] like Figure 5A As shown, the piezoelectric vibrating reed 20 is placed on a stepped portion 51 formed on the inner wall of the housing 50, with the portion being larger than the outer diameter of the inner bottom 52 of the housing 50. This divides the housing space 55 into a first space 55a and a second space 55b. This configuration allows the piezoelectric vibrating reed 20 to be easily attached to the housing 50 by orienting the opening of the housing space 55 upward along the Z-axis. Furthermore, by forming the spaces 55a and 55b above and below the piezoelectric vibrating reed 20, the piezoelectric vibrating reed 20 can vibrate sufficiently, facilitating the production of desired sounds.

[0172] In addition, in this embodiment, Figure 4 As shown, the cover substrate 40 has a limiting Figure 5A The piezoelectric vibrating piece 20 shown in the figure has a stopper protrusion 49 that moves toward the conductive terminals 60 and 70. The stopper protrusion 49 is formed on the inner surface 41b of the lid-shaped substrate 40 so as to correspond to the shape of the outer periphery of the piezoelectric vibrating piece 20.

[0173] When surface-mounting the piezoelectric sound-generating body 20 onto a circuit board or the like, the outer surface 41a of the cover-shaped substrate 40 is positioned downward. However, the piezoelectric vibrating piece 20 can shift toward the conductive terminals 60 and 70 due to its own weight or external impact. In this embodiment, the stopper protrusion 49 prevents the piezoelectric vibrating piece 20 from excessively shifting toward the conductive terminals 60 and 70, thereby improving impact resistance. Furthermore, the presence of the stopper protrusion 49 prevents excessive deformation of the front end portions 62 and 72, maintaining their elasticity.

[0174] In addition, in this embodiment, Figure 4 As shown in FIG. 1 , the front end portions 62 and 72 have substantially hemispherical contact protrusions 62b and 72b. Figure 5A The piezoelectric vibrating piece 20 shown in FIG. 1 is in contact with the piezoelectric vibrating piece 20, which can effectively prevent contact failure, etc. The piezoelectric vibrating piece 20 is usually in the shape of a circular disk, but may also be in the shape of a rectangular disk or a polygonal disk.

[0175] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes can be made within the scope of the present invention.

[0176] For example, the reinforcing holes 68d and 78d serve to reinforce the fixation between the inner portions 68a and 78a of the conductive terminals 60 and 70 and the lid substrate 40, but they do not necessarily need to be holes and may be, for example, concave and convex reinforcing portions.

[0177] In addition, in the above-mentioned embodiment, the front end portions 62 and 72 are in direct contact with the piezoelectric vibrating piece 20 without using solder or conductive paste, and the front end portions 62 and 72 are electrically connected to the piezoelectric vibrating piece 20 by pressing the piezoelectric vibrating piece 20 toward the side of the housing 50. However, solder, conductive paste, etc. can also be used for electrical connection.

Claims

1. A piezoelectric sounding body, characterized in that: have: Piezoelectric vibrating piece; a housing for accommodating the piezoelectric vibrating piece; a cover-shaped substrate mounted on the housing and forming a storage space for the piezoelectric vibrating piece together with the housing; and a conductive terminal electrically connected to the piezoelectric vibrating piece, The conductive terminal has a front end portion that elastically presses the piezoelectric vibrating piece toward the housing; and a terminal body connected to the front end portion, The front end portion has an inclined portion extending from the terminal body toward the outer edge of the lid-shaped substrate and inclined toward the piezoelectric vibrating piece. The tip portion can elastically press and hold the piezoelectric vibrating piece toward the housing with a constant force by utilizing the inclined portion that is inclined toward the piezoelectric vibrating piece. The inclined portion is inclined from an inner side surface perpendicular to the longitudinal direction of the through hole of the lid-shaped substrate toward the piezoelectric vibrating piece. At least a portion of the terminal body is embedded in the lid-shaped substrate and fixed thereto.

2. The piezoelectric sound-generating body according to claim 1, wherein: The through hole communicates with the accommodation space from the outside of the lid-shaped substrate, and the front end portion protrudes from the lid-shaped substrate and is disposed inside the through hole.

3. The piezoelectric sound-generating body according to claim 2, wherein: The lid-shaped substrate has a groove portion extending from the through-hole toward an outer edge of the lid-shaped substrate to connect the interior of the through-hole with the exterior of the housing.

4. The piezoelectric sound-generating body according to claim 3, wherein: The through-holes are composed of at least one pair of through-holes, and the through-holes communicate with each other inside the storage space.

5. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: A sound emission hole is formed on the outer wall side of the housing and communicates from the storage space to the outside of the housing.

6. The piezoelectric sound-generating body according to claim 5, wherein: The front end portion extends toward the outer wall side surface opposite to the outer wall side surface of the housing where the sound emission hole is formed.

7. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The terminal body has: an inner portion connected to the front end portion and parallel to the piezoelectric vibrating piece; an outer portion arranged parallel to the inner portion and positioned at a different level from the inner portion; and An intermediate portion is located between the inner portion and the outer portion.

8. The piezoelectric sound-generating body according to claim 7, wherein: The middle portion is connected to the inner portion and the outer portion, respectively, in a manner inclined relative to the inner portion and the outer portion.

9. The piezoelectric sound-generating body according to claim 7, wherein: The inner portion and the middle portion are embedded in the lid-shaped substrate.

10. The piezoelectric sound-generating body according to claim 7, wherein: The inner portion has a reinforcement portion for reinforcing fixation with the lid-shaped substrate.

11. The piezoelectric sound-generating body according to claim 7, wherein: The inner portion has a heat conduction reduction portion for reducing heat conduction toward the front end portion.

12. The piezoelectric sound-generating body according to claim 7, wherein: The outer portion and the outer surface of the lid-shaped substrate are located in the same plane.

13. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The conductive terminal includes a holding portion connected to the outer side of the terminal body so as to protrude from the cover-shaped substrate at a position different from the front end portion, and the holding portion is engaged with the housing.

14. The piezoelectric sound-generating body according to claim 13, wherein: The holding portion includes a bent piece bent toward the housing, and a bending direction of the bent piece coincides with a direction in which the front end portion of the conductive terminal elastically presses the piezoelectric vibrating piece.

15. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The cover substrate has at least one engaging protrusion on its outer periphery for engaging with the housing. The housing has at least one engaging recess corresponding to a shape of the engaging projection.

16. The piezoelectric sound-generating body according to claim 15, characterized in that: The lid-shaped substrate has a plurality of outer peripheral corner portions, and the engaging protrusion protruding outward on the same plane as the lid-shaped substrate is formed at at least one of the outer peripheral corner portions.

17. The piezoelectric sound-generating body according to claim 15, wherein: The bottom surface and the side surfaces of the engaging recess are welded to the engaging protrusion.

18. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The piezoelectric vibrating piece is arranged inside the housing space so as to divide the housing space into a first space and a second space. The volume of the first space is larger than the volume of the second space, The front end portion of the conductive terminal is disposed inside the second space.

19. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The piezoelectric vibrating reed is placed on a step formed on the inner wall surface of the housing, dividing the housing space into a first space and a second space.

20. The piezoelectric sound-generating body according to claim 1 or 2, characterized in that: The lid-shaped substrate has a stopper protrusion for restricting movement of the piezoelectric vibrating piece toward the conductive terminal.

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