JP2011053561A - Siren - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a siren which is small and which can emit a megavolume of sound. <P>SOLUTION: The siren has a piezoelectric plate 11 that oscillates by application of a voltage, a vibrating plate 12 that is formed in an approximately dome shape with a bulging portion 121 that bulges toward one face and a flange portion 122 formed at a periphery of the bulging portion 121, and in which the piezoelectric plate 11 is provided so as to cover a concave portion 123 formed at the other face side of the bulging portion 121 and vibration of the piezoelectric plate 11 is transmitted, thereby emitting a sound, and a housing 10 at which the vibrating plate 12 is fixed, and the housing 10 is configured with a cover 14 and a case 15, and the flange portion 122 of the vibrating plate 12 is put between the cover 14 and the case 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a siren.

  Conventionally, a substantially disk-shaped piezoelectric plate that vibrates when a voltage is applied to it, and a substantially dome-shaped bulge that bulges to one side, and its peripheral edge is bonded to the piezoelectric plate to transmit the vibration of the piezoelectric plate. There is provided a siren including a diaphragm that vibrates and emits sound, and a housing to which the piezoelectric plate and the diaphragm are attached and to which the peripheral portion of the piezoelectric plate is fixed (see, for example, Patent Document 1).

  The siren is used, for example, as a vehicle-mounted siren for a vehicle antitheft device or the like, and when an abnormality or the like occurs in the vehicle, a high-volume alarm sound is issued to notify the abnormality.

  Here, since many of the on-vehicle sirens are often disposed in a limited space such as in a vehicle, downsizing has been desired.

JP-A-7-79496

  However, in general, when the siren size is reduced, the size of the piezoelectric plate and the diaphragm is also reduced, and the sound emitted from the siren is also reduced. Therefore, it is difficult to reduce the size of the siren while maintaining the sound volume.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a siren that is small in size and can emit a large volume.

  The invention of claim 1 is formed in a substantially dome shape from a piezoelectric plate that vibrates when a voltage is applied, a bulging portion that bulges to one surface side, and a collar portion that is formed at the periphery of the bulging portion, A diaphragm in which the piezoelectric plate is covered in a recess formed on the other surface side of the bulging portion and vibration is generated by transmitting vibrations of the piezoelectric plate, and a housing to which the piezoelectric plate and the diaphragm are attached The housing is characterized in that the flange portion of the diaphragm is fixed.

  According to the present invention, the sound pressure can be increased in a siren having a piezoelectric plate. For example, even when the siren is miniaturized by being applied to a vehicle-mounted siren or the like, the conventional loud sound is emitted. be able to.

  According to a second aspect of the present invention, in the first aspect of the present invention, the housing includes a first housing member and a second housing member, and the diaphragm includes the first housing member and the second housing member. And an elastic material is provided between at least one of the first housing member and the diaphragm and between the second housing member and the diaphragm.

  According to the present invention, since the elastic material is interposed between the housing and the diaphragm, it is possible to suppress the vibration of the diaphragm from being attenuated by the holding portion, and it is possible to prevent a decrease in sound pressure. Further, since the vibration of the diaphragm is prevented, the vibration of the diaphragm can be stabilized and the sound pressure can be improved.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the diaphragm has a thickness of 0.2 mm or less.

  According to the present invention, the improvement in sound pressure and the ease of processing can be satisfied at the same time. Furthermore, since it can be formed with a thickness equal to that of a pre-made diaphragm, it is easy to divert pre-made components.

  According to a fourth aspect of the present invention, in the invention according to the third aspect, the diaphragm has a quotient of the diameter of the opening in the bulging portion with respect to the height of the bulging portion is 0.2 or more.

  According to this invention, the improvement of sound pressure and the ease of processing can be satisfied simultaneously.

  As described above, according to the present invention, there is an effect that it is possible to provide a siren that is small in size and can emit a large volume.

The sectional view of the siren in the embodiment of the present invention is shown. (a)-(c) shows the cover of the siren same as the above, (a) is a rear view, (b) is a sectional view, and (c) is a side view. (a)-(c) shows the case of the siren same as the above, (a) is a front view, (b) is a sectional view, and (c) is a side view. (A)-(c) shows the horn member of the siren same as the above, (a) is a rear view, (b) is a sectional view, and (c) shows a side view. The perspective view of the housing cover of the siren same as the above is shown. The relationship figure of the sound pressure with respect to the thickness of the diaphragm of a siren in the same as the above is shown. The relationship figure of the sound pressure with respect to the height ratio (bulging height / bulging part diameter) of the diaphragm of a siren in the same as the above is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
As shown in FIG. 1, the siren in the present embodiment is formed on the piezoelectric plate 11 that vibrates when a voltage is applied, the bulging portion 121 that bulges to the front side, and the periphery of the bulging portion 121. A diaphragm 12 formed in a substantially dome shape from the flange 122 and formed on the piezoelectric plate 11 with a recess 123 formed on the rear surface side of the bulging portion 121, and a housing 10 for housing the piezoelectric plate 11 and the diaphragm 12. And the sound generation unit 1 composed of the horn member 16 fixed to the front surface of the housing 10, the circuit board 2 disposed on the rear surface side of the sound generation unit 1, and a hollow box shape having an open front surface. A housing cover 3 that houses the circuit board 2 and is provided with the sounding unit 1 on the front surface side. In the following description, the vertical direction in FIG.

  The piezoelectric plate 11 is made of a substantially disk-shaped ceramic piezoelectric body, and electrodes (not shown) are provided on both surfaces thereof.

  The diaphragm 12 is made of, for example, a material having a large specific rigidity, such as aluminum, and has a substantially domed shape from a bulging portion 121 that bulges forward and a substantially annular flange portion 122 formed at the periphery of the bulging portion 121. Is formed. The material of the diaphragm 12 may be magnesium, titanium, beryllium, or the like.

  A substantially annular curved portion 122a curved rearward is formed at substantially the center in the radial direction of the flange portion 122, and a substantially annular adhesive portion 122b is formed inside the curved portion 122a. A substantially annular held portion 122c is formed outside 122a. Then, the piezoelectric plate 11 is fixed to the vibration plate 12 by bonding the peripheral portion of the piezoelectric plate 11 to the bonding portion 122b.

  The housing 10 includes a cover 14 provided on the front side of the diaphragm 12 and a case 15 provided on the rear side of the diaphragm 12 and covered with the cover 14.

  As shown in FIGS. 1 and 2, the cover 14 includes a substantially dome-shaped bulged portion 141 provided to face the bulged portion 121 of the diaphragm 12 through the air chamber 13, and a peripheral portion of the bulged portion 141. And a peripheral wall 143 extending substantially perpendicularly to the flange 142 from the periphery of the flange 142. Further, a substantially annular groove 142a is formed on the front surface of the flange 142 along the inner periphery of the flange 142, and the peripheral wall 143 has a plurality of substantially equal intervals along the circumferential direction. A locking hole 143a is formed.

  As shown in FIG. 3, the case 15 is formed in a substantially cylindrical shape with an open front surface, and a locking projection 15 a protrudes outward from the peripheral edge of the opening of the peripheral wall. Then, after the piezoelectric plate 11 and the vibration plate 12 are housed in the case 15, the cover 14 is covered with the opening of the case 15. At that time, the locking projection 15a in the case 15 is locked in the locking hole 143a of the cover 14, whereby the case 15 and the cover 14 are fixed.

  Here, a fitting portion 15 c having a substantially L-shaped cross section is formed on the opening periphery of the case 15, and two grooves 144 a and 144 b having different depths are formed on the periphery of the collar portion 142 of the cover 14. A side-by-side fitting portion 144 is formed. The fitting portion 144 has a groove 144b deeper than the inner groove 144a in parallel with the outside of the groove 144a. When the cover 14 is attached to the case 15, the fitting portion 15c of the case 15 The front end fits into the groove 144b, and the flange 122 of the diaphragm 12 is sandwiched between the bottom of the fitting section groove 15c and the groove 144a together with the roll edge 23, and the diaphragm 12 is nipped and fixed. .

  As shown in FIG. 4, the horn member 16 has a substantially central inner diameter that is the smallest, and is formed in a substantially cylindrical shape whose diameter is expanded from there to the front end side and the rear end side, and both ends are open. A stepped portion 16a having a substantially L-shaped cross section is formed at the rear open end of the horn member 16, and the stepped portion 16a is fitted into the groove 142a of the cover 14, so that the horn member 16 is covered. 14 is fixed. A horn space 17 is formed in a space surrounded by the inner wall of the horn member 16 and the front surface of the bulging portion 141.

  Further, a communication hole 142b is formed on the inner peripheral side of the collar portion 142 in the cover 14, and the air chamber 13 and the horn space 17 communicate with each other through the communication hole 142b.

  Further, a substantially annular flange 161 is formed on the rear end side of the horn member 16, and two substantially annular protrusions 161 a that are substantially perpendicular to the flange 161 are formed on the periphery of the flange 161. 161b are juxtaposed, and a groove 161c is formed between the protrusion 161a and the protrusion 161b.

  The circuit board 3 is provided to face the rear surface of the case 15 and is connected to the electrode of the piezoelectric plate 11 via a wiring (not shown). Here, the wiring is drawn into the case 15 by being arranged along the groove 15b formed from the side surface of the case 15 to the peripheral edge of the opening, and connects the circuit board 3 and the electrode of the piezoelectric plate 11 to each other. To do.

  As shown in FIG. 5, the housing cover 3 is formed in a substantially cylindrical shape having an open front surface, the circuit board 3 is accommodated on the bottom surface side, and the sound generation unit 1 is provided on the opening side. More specifically, the horn member 16 is fixed to the housing cover 3 by fitting the opening peripheral edge portion of the housing cover 3 into the groove portion 161 c of the horn member 16 via the roll edge 24.

  Further, a substantially cylindrical connector portion 3a is provided on the rear surface of the housing cover 3. The rear surface of the housing cover 3 is inserted into the connector portion 3a and one end projects into the connector portion 3a. A plurality of terminals 18 whose ends protrude into the housing cover 3 are disposed. And the terminal 18 which protrudes in the housing cover 3 is connected to the circuit board 2 via the wiring etc. which are not shown in figure.

  Further, from the outer peripheral surface of the housing cover 3, a bracket connection portion 31 having a substantially L-shaped cross section with a notch 31 a formed at the tip is extended. On the other hand, a substantially L-shaped bracket 19 is attached to the vehicle body to which the siren is attached, and a screw 21 inserted through the insertion hole 19a drilled in the bracket 19 and the notch 41a is screwed into the nut 22. When the housing cover 3 and the bracket 19 are fastened together, the siren is fixed to the vehicle body.

  An external connector (not shown) is connected to the connector portion 3 a of the housing cover 3, and a notification signal input from an external device or the like via the external connector is input to the circuit board 2 via the terminal 18. When the notification signal is input, the circuit board 2 outputs a voltage signal to the piezoelectric plate 11, and the piezoelectric plate 11 to which the voltage signal is input vibrates. Subsequently, the vibration of the piezoelectric plate 11 is transmitted to the vibration plate 12, and the vibration plate 12 is also vibrated and a sound is emitted from the vibration plate 12.

  The siren of the present embodiment having the above-described configuration is different in structure from the conventional siren that fixes the piezoelectric element to the housing, and the flange portion 122 of the substantially dome-shaped diaphragm 12 to which the piezoelectric plate 11 is bonded is fixed to the housing 10. As a result, the amplitude of the diaphragm 12 becomes larger than the conventional one, and the sound pressure can be improved. Therefore, even when the siren of this embodiment is downsized to be used as a vehicle-mounted siren, notification can be performed with the same high volume as before.

  Further, the sound emitted from the diaphragm 12 propagates from the air chamber 13 to the horn space 17 through the communication hole 142b. Here, the Helmholtz resonator is formed by the air chamber 13 and the communication hole 142b, and the sound pressure of the sound emitted from the diaphragm 14 is increased by the Helmholtz resonator. Further, the sound pressure of the sound whose sound pressure has been increased by the Helmholtz resonator is further increased by the horn space 17.

  Furthermore, since the cover 14 serves as both the components of the Helmholtz resonator and the horn, the number of components can be reduced, the space for component placement can be reduced, and the siren can be miniaturized. That is, in the present invention, the siren can be reduced in size while improving the sound pressure.

  Further, since the flange portion 122 of the diaphragm 12 is sandwiched between the cover 14 and the case 15 via the roll edge 23, the vibration of the diaphragm 12 can be prevented from being attenuated at the sandwiched portion. Furthermore, since it is possible to suppress rolling of the diaphragm 12 due to vibration generated when a siren is provided in a vehicle, for example, the diaphragm 12 can be vibrated stably, and sound pressure can be reduced. Can be improved.

  In general, as shown in FIG. 6, the diaphragm 12 formed in a substantially dome shape can emit a sound having a larger sound pressure as the thickness thereof is thinner. Therefore, in this embodiment, the diaphragm 12 is formed of an aluminum plate having a thickness of 0.2 mm or less that can sufficiently obtain sound pressure and can be easily processed. Moreover, since the said thickness is the thickness used by the existing diaphragm, there exists a merit that it is easy to divert an existing component.

  Furthermore, as shown in FIG. 3, when the thickness of the diaphragm 12 is 0.1 mm, the quotient of the diameter of the opening of the bulging portion 121 relative to the bulging height of the diaphragm 12 is 0.24. Maximum sound pressure can be obtained. Therefore, when the thickness of the diaphragm 12 is set to 0.1 mm, the sound pressure is further improved by setting the bulge height and the diameter so that the quotient value is approximately 0.24. be able to.

DESCRIPTION OF SYMBOLS 10 Housing 11 Piezoelectric plate 12 Diaphragm 14 Cover 15 Case 23 Roll edge (elastic material)
121 bulging portion 122 ridge portion 123 concave portion

Claims (4)

A piezoelectric plate that vibrates when a voltage is applied;
It is formed in a substantially dome shape from a bulging portion that bulges to one side and a flange formed on the periphery of the bulging portion, and the piezoelectric plate is covered in a recess formed on the other side of the bulging portion. A vibration plate that vibrates by transmitting vibrations of the piezoelectric plate and generates sound,
A siren comprising: a housing having fixing means for fixing a collar portion of the diaphragm. The housing is composed of a first housing member and a second housing member,
The fixing means has a configuration in which the first housing member and the second housing member sandwich the flange portion of the diaphragm, the first housing member and the diaphragm, and the second housing member. The siren according to claim 1, wherein an elastic material is provided on at least one of the diaphragm and the diaphragm.   The siren according to claim 1 or 2, wherein the diaphragm has a thickness of 0.2 mm or less. The siren according to any one of claims 1 to 3, wherein the diaphragm has a quotient of a diameter of an opening in the bulging portion with respect to a height dimension of the bulging portion.

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