JP2007264996A - Fire alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve reduction of the number of components, reduction of assembling man-hours, and miniaturization/thinning, and to efficiently perform sound output. <P>SOLUTION: This fire alarm has an alarm body 2 comprising a cover 4 bored with a sound hole 4a and a main body 3 mutually fastened to the cover 4, and having a fire detection part 6 sensing at least smoke, heat or the like to detect a fire and a sound structure part 9 raising an alarm when abnormality is detected thereinside, and is installed on a ceiling or a wall face. In the fire alarm, the sound structure part 9 comprises: a piezoelectric oscillation plate 14; a first tube-like part 4b covering the circumference of the sound hole 4a such that a peripheral part of the piezoelectric oscillation plate 14 can abut, and projecting to the inner face of the cover 4; and a second tube-like part 3c sandwiching and fixing the peripheral part of the piezoelectric oscillation plate 14 in cooperation with the first tube-like part 4b of the cover 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fire alarm installed in a detached house, and more particularly, to a fire alarm capable of efficiently outputting sound, which can reduce the number of parts, reduce the number of assembly steps, and can be reduced in size and thickness.

  This type of fire alarm, that is, a fire alarm installed in a detached house, is detachably attached to a fixing means such as a base that is attached to the ceiling or wall surface, and is detachably attached to the fixing means. And an alarm body that issues an alarm when an abnormality is detected. Furthermore, the alarm main body is composed of a cover and a main body, which are fastened to each other by screws or the like.

  In such a case, in order to reduce the cost and size, it is preferable to use a piezoelectric buzzer using a piezoelectric diaphragm rather than an alarm output by a speaker. Therefore, for example, a fire alarm device has been proposed in which a smoke detector is mounted and a piezoelectric buzzer is placed on a circuit board provided on the main body side, thereby reducing the size and thickness and further reducing the cost. (For example, refer to Patent Document 1).

  By the way, in this arrangement in which the piezoelectric buzzer is superimposed on the circuit board, the piezoelectric buzzer is disposed on the main body side of the alarm device main body and the piezoelectric vibration plate having an acoustic hole. And an acoustic box that forms an acoustic space, and this acoustic box is attached to the main body side with a buzzer fixing screw through a packing. In addition, acoustic holes are respectively provided in the circuit board and the cover so as to be opposed to the acoustic holes of the acoustic box, thereby constituting the acoustic structure of the alarm device.

JP 2006-40212 A

  However, in the case where the piezoelectric buzzer is provided on the main body side so as to overlap the circuit board, the sound generated by the piezoelectric diaphragm passes from the acoustic space in the acoustic box to the acoustic hole and from there the acoustic of the circuit board. It passes through the hole and propagates through the space in the cover of the alarm body, and is output to the outside through the acoustic hole of the cover. For this reason, there is inevitably a gap between the piezoelectric diaphragm and the acoustic hole of the cover, and the sound pressure actually output from the acoustic hole of the cover is lost, which is not efficient.

  In addition, a piezoelectric diaphragm, an acoustic box, packing, a buzzer fixing screw, and the like are necessary, and the number of parts is large, and assembly work is complicated.

  The technical problem of the present invention is to reduce the number of parts, reduce the number of assembly steps, reduce the size and thickness, and enable efficient sound output.

  The fire alarm device according to the present invention has the following configuration. In other words, it consists of a cover with an acoustic hole and a body that is fastened to this cover, and fires when an abnormality is detected when a fire detection unit detects a fire by detecting smoke or heat at least inside. In a fire alarm provided on a ceiling or wall surface with an alarm body having an acoustic structure, the acoustic structure can be contacted with a piezoelectric diaphragm and a peripheral portion of the piezoelectric diaphragm. A first cylindrical part that covers the periphery and projects from the inner surface of the cover, and a second cylindrical part that cooperates with the first cylindrical part of the cover and clamps and fixes the periphery of the piezoelectric diaphragm. It is a thing.

  The second cylindrical portion protrudes from the main body, and the first cylindrical portion and the second cylindrical portion sandwich and fix the piezoelectric diaphragm using the fastening force when the main body and the cover are fastened. To do.

  In addition, an outer cylindrical portion that houses the piezoelectric diaphragm and covers the holding portion by the first and second cylindrical portions is provided outside the first cylindrical portion of the cover or outside the second cylindrical portion. It is a thing.

  In the fire alarm according to the present invention, the acoustic structure portion is a first cylindrical shape that covers the acoustic hole and protrudes from the inner surface of the cover so that the piezoelectric diaphragm and the peripheral portion of the piezoelectric diaphragm can come into contact with each other. Part and the second cylindrical part that clamps and fixes the peripheral part of the piezoelectric diaphragm in cooperation with the first cylindrical part of the cover, so that the number of parts can be reduced and the number of assembly steps can be reduced. Reduction can be achieved, and the size and thickness can be reduced. In addition, since the piezoelectric diaphragm is directly fixed to the cover by the first and second cylindrical portions that hold the piezoelectric diaphragm and integrated, the vibration can be transmitted to the cover. For this reason, it becomes possible to output sound efficiently by utilizing resonance. Furthermore, as the number of parts is reduced, the number of noise sources is reduced, and a clearer sound can be output. Furthermore, since the piezoelectric diaphragm is disposed on the cover side, the distance between the piezoelectric diaphragm and the acoustic hole is shortened, and loss of sound pressure output from the acoustic hole can be reduced.

  The second cylindrical portion protrudes from the main body, and the first cylindrical portion and the second cylindrical portion sandwich and fix the piezoelectric diaphragm using the fastening force when the main body and the cover are fastened. Therefore, the assembling property is improved.

  In addition, an outer cylindrical portion that accommodates the piezoelectric diaphragm and covers the holding portion by the first and second cylindrical portions is provided outside the first cylindrical portion or the second cylindrical portion of the cover. Therefore, the installation part of the piezoelectric diaphragm has a double cylinder configuration, and the outer diaphragm can guide the piezoelectric diaphragm to the installation part. For this reason, the positioning of the piezoelectric diaphragm is facilitated, and the assemblability is further improved.

The present invention will be described below with reference to illustrated embodiments.
1 is a front view showing a fire alarm according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is a rear view showing a cover of the main body of the alarm device, FIG. 5 is a rear view showing a state where the circuit board and the piezoelectric diaphragm are installed on the cover, FIG. 6 is a front view showing the main body of the alarm device main body, FIG. Is a rear view of the main body, and FIG. 8 is a rear view of the main body of the alarm device formed by assembling the cover and the main body.

  The fire alarm device of the present embodiment is composed of a base 1 as a fixing means installed on a ceiling or a wall surface, and an alarm device body 2 whose back side is formed so that a twist lock can be fitted to the base 1, and further the alarm device body. 2 includes a main body 3 and a cover 4 in which an acoustic hole 4a is formed, and the main body 3 and the cover 4 are fastened to each other by a plurality of screws 5.

  More specifically, the twist lock fitting portion includes a cylindrical portion 1a provided on the base 1, a cylindrical portion 3a provided on the main body 3 so as to be fitted inside the cylindrical portion 1a, and a main body 3. A blade portion 3b that is formed to extend inward from the cylindrical portion 3a that is formed, and a blade that is formed to extend outward from the second tube portion 1b provided on the inner side of the cylindrical portion 1a of the base 1 in a substantially L-shaped cross section. A blade receiving portion (not shown) for receiving the portion 3b, the cylindrical portions 3a and 1a are fitted in a state where the blade portion 3b and the blade receiving portion are shifted in the circumferential direction, and the blade portion 3b By rotating the main body 3 relative to the base 1 in the direction in which the blade receiving portion is engaged, the main body 3, that is, the alarm main body 2 can be twist-locked to the base 1, and the procedure reverse to that described above. The main body 3, that is, the alarm main body 2 can be removed from the base 1. There.

  The alarm device body 2 is provided with a smoke sensor as a fire detection unit 6 for detecting smoke by detecting smoke or heat, a circuit board 7 inside, an indicator lamp 8 for displaying a fire, An acoustic structure 9 for notifying a fire, a switch 11 and a battery 12 are provided.

  The switch 11 is externally operated by a push button 13 installed on the front surface of the cover 4, and the operation of the switch 11 by the push button 13 can stop an alarm sound in the event of a fire. Inspection is now possible.

  The acoustic structure 9 includes a piezoelectric diaphragm 14 and a first tubular portion 4b that covers the acoustic hole 4a and protrudes from the inner surface (rear surface) of the cover 4 so that the peripheral edge of the piezoelectric diaphragm 14 can come into contact therewith. The first cylindrical portion 4b of the cover 4 includes a second cylindrical portion 3c protruding from the front of the main body 3 so as to be able to hold the peripheral edge of the piezoelectric diaphragm 14 in cooperation with the first cylindrical portion 4b. The cylindrical portion 4b and the second cylindrical portion 3c are configured to clamp and fix the piezoelectric diaphragm 14 using a fastening force at the time of fastening by the screw 5 of the main body 3 and the cover 4.

  Further, outside the first cylindrical portion 4b of the cover 4, the first and second cylindrical portions 4b, 4b, which accommodate a piezoelectric diaphragm 14 higher than the protruding height of the first cylindrical portion 4b, The outer cylinder part 4c which covers the holding part by 3c is provided, the installation part of the piezoelectric diaphragm 14 has a double cylinder structure, and the piezoelectric diaphragm 14 can be guided to the installation part by the outer cylinder part 4c. It is like that.

  Further, notches 4d and 3d are formed at positions where the outer cylindrical portion 4c of the cover 4 and the second cylindrical portion 3c of the main body 3 coincide with each other in the circumferential direction at the time of fastening, and the notches 4d and 3d are respectively formed. The lead wire 14a of the piezoelectric diaphragm 14 is drawn out from the above.

  In addition, a plurality of locking claws 4 e for positioning the circuit board 7 on a plane are provided on the inner surface (rear face) of the cover 4, and the circuit board 7 is provided on the front surface of the main body 3. A plurality of substrate holders 3e are provided to protrude.

  In addition, vertical grooves 4f for circumferential alignment with the main body 3 are formed at two locations on the inner surface of the peripheral wall of the cover 4, and penetrate into the vertical grooves 4f of the cover 4 at two locations on the outer peripheral surface of the main body 3. Possible projections 3f are formed.

  A power supply unit (not shown) that is mounted on the circuit board 7 and supplies power from the battery 12 to the piezoelectric diaphragm 14 is provided with a pulse current converter for vibrating the piezoelectric diaphragm 14. The pulse frequency is set so that the piezoelectric diaphragm 14 vibrates in the resonance frequency band of the natural frequency of the alarm body 2, particularly the cover 4. For this reason, the alarm is sounded by the resonance of the cover 4 to which the vibration of the piezoelectric diaphragm 14 is directly transmitted, and the sound can be output efficiently.

  Next, a procedure for assembling the fire alarm device of the present embodiment and installing it on the ceiling or wall surface will be described. Here, it is assumed that the lead wire 14 a of the piezoelectric diaphragm 14 is already connected to the circuit board 7. First, the base 1 is installed on the ceiling or wall where the base 1 is to be attached. Next, the circuit board 7 on which the fire detection unit 6 and the like are mounted is installed on the engaging claw 4e on the back side of the cover 4, and the piezoelectric diaphragm 14 is connected to the lead tube 14a in the outer cylinder part 4c of the cover 4. It fits so that it may become upper, and is mounted on the 1st cylindrical part 4b, and the lead wire 14a is pulled out of the cylindrical part from the notch 4d of the outer cylindrical part 4c. Thereby, the circuit board 7 and the piezoelectric diaphragm 14 are positioned as shown in FIG.

  Next, the vertical grooves 4f on the peripheral wall on the back side of the cover 4 and the projections 3f on the peripheral wall of the main body 3 are aligned, and the front side of the main body 3 is fitted on the back side of the cover 4 so that these are engaged. Then, the screw 5 is screwed into the first screwed portion 4g of the cover 4 from the second screwed portion 3g side of the main body 3 and tightened to fasten and fix the main body 3 and the cover 4 to each other. As shown in FIG. As a result, the circuit board 7 is pressed from the back side by the board presser 3e in the alarm device body 2 and pressed and fixed to the locking claw 4e of the cover 4, and the piezoelectric diaphragm 14 is fixed to the outer cylinder part. Within 4c, the peripheral part is clamped and fixed by the first cylindrical part 4b on the cover 4 side and the second cylindrical part 3c on the main body 3 side. Next, in the alarm device body 2 assembled in this manner, a connector (not shown) of the battery 12 provided on the back side and a connector (not shown) of the circuit board 7 are connected.

  Thereafter, the cylindrical portion 3a of the main body 3 is fitted to the cylindrical portion 1a on the base 1 side while the main body 3, that is, the blade portion 3b of the alarm device main body 2 and the blade receiving portion of the base 1 are shifted in the circumferential direction. The alarm body 2 is rotated relative to the base 1 in the direction in which the blade portion 3b and the blade receiving portion are engaged. Thereby, the alarm device body 2 is twist-locked to the base 1 and the installation of the fire alarm device is completed.

  As described above, the fire alarm of the present embodiment covers the acoustic structure 9 on the inner surface of the cover 4 so as to cover the acoustic hole 4a so that the piezoelectric diaphragm 14 and the peripheral portion of the piezoelectric diaphragm 14 can come into contact with each other. The projecting first tubular portion 4b and the second tubular portion projecting from the main body 3 so as to be able to hold the peripheral edge of the piezoelectric diaphragm 14 in cooperation with the first tubular portion 4b of the cover 4. 3c, and the piezoelectric diaphragm 14 is directly fixed to the cover 4 and the main body 3 by the first and second cylindrical portions 4b and 3c that hold the piezoelectric diaphragm 14, so that they are integrated. The number of parts can be reduced, the number of assembly steps can be reduced, and the size and thickness can be reduced. In addition, since vibration can be transmitted to the cover 4 and the main body 3, it is possible to output sound efficiently by using resonance. Furthermore, as the number of parts is reduced, the number of noise sources is reduced, and a clearer sound can be output. Furthermore, since the piezoelectric diaphragm 14 is disposed on the cover 4 side, the distance between the piezoelectric diaphragm 14 and the acoustic hole 4a is shortened, and the loss of sound pressure output from the acoustic hole 4a can be reduced. . Note that the second cylindrical portion 3c may be formed of a separate member without being provided in the main body 3, and an effect similar to the above can be obtained only by increasing the number of parts by the amount of the second cylindrical portion 3c. It is done.

  In addition, the first cylindrical portion 4b and the second cylindrical portion 3c clamp and fix the piezoelectric diaphragm 14 by using the fastening force at the time of fastening by the screw 5 of the main body 3 and the cover 4, so that the assembly is performed. Improves.

  In addition, the piezoelectric diaphragm 14 is accommodated outside the first cylindrical portion 4b of the cover 4 or outside the second cylindrical portion 3c of the main body 3, and the first and second cylindrical portions 4b and 3c are accommodated. The outer cylinder part 4c which covers the holding part is provided so that the installation part of the piezoelectric diaphragm 14 has a double cylinder structure, and the piezoelectric diaphragm 14 can be guided to the installation part by the outer cylinder part 4c. Therefore, the positioning of the piezoelectric diaphragm 14 is facilitated and the assemblability is further improved.

  Here, the outer cylinder part 4c is provided outside the first cylindrical part 4b of the cover 4, and the piezoelectric diaphragm 14 is positioned so that the installation part of the piezoelectric diaphragm 14 has a double cylinder structure. Although the above description has been given by taking the example of being easily made, the outer cylindrical portion 4c may be installed outside the second cylindrical portion 3c in the main body 3, and even in this case, There exists an effect equivalent to embodiment.

  Here, the base 1 has been described as an example of the fixing means. However, it is only necessary that the alarm device body 2 can be installed on the ceiling or the wall surface by the fixing device. For example, it is provided on the back side (installation surface side) of the alarm device body 2. It may be a locking tool or a mounting screw that is locked in the locking hole.

It is a front view which shows the fire alarm which concerns on one Embodiment of this invention. It is AA arrow sectional drawing of FIG. It is a BB arrow directional cross-sectional view of FIG. It is a rear view which shows the cover of the fire alarm which concerns on one Embodiment of this invention. It is a rear view which shows the state which installed the circuit board and the piezoelectric diaphragm in the cover of the fire alarm which concerns on one Embodiment of this invention. It is a front view which shows the main body of the alarm main body of the fire alarm which concerns on one Embodiment of this invention. It is a rear view which shows the main body of the alarm main body of the fire alarm which concerns on one Embodiment of this invention. It is a rear view of the alarm main body of the fire alarm which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Alarm main body 3 Main body 3c 2nd cylindrical part 3g 2nd screwing part 4 Cover 4a Sound hole 4b 1st cylindrical part 4c Outer cylinder part 4g 1st screwing part 5 Screw 6 Fire detection Part 9 Acoustic structure part 14 Piezoelectric diaphragm

Claims (3)

An acoustic structure comprising a cover with an acoustic hole and a main body fastened to the cover, and detecting a fire by detecting smoke or heat at least inside and an acoustic structure for issuing an alarm when an abnormality is detected In the fire alarm installed on the ceiling and wall,
The acoustic structure
A piezoelectric diaphragm;
A first cylindrical portion that covers the periphery of the acoustic hole and protrudes from the inner surface of the cover so that a peripheral edge portion of the piezoelectric diaphragm can be contacted;
A second cylindrical part that clamps and fixes the peripheral edge of the piezoelectric diaphragm in cooperation with the first cylindrical part of the cover;
A fire alarm characterized by comprising   The second cylindrical portion protrudes from the main body, and the first cylindrical portion and the second cylindrical portion use the fastening force when the main body and the cover are fastened to make the piezoelectric vibration. 2. The fire alarm according to claim 1, wherein the plate is clamped and fixed. An outer cylinder that houses the piezoelectric diaphragm on the outside of the first tubular portion or the outside of the second tubular portion of the cover and covers the holding portion by the first and second tubular portions. The fire alarm according to claim 1, wherein a fire alarm is provided.

Images