Fire alarm

Abstract

To provide a fire alarm device capable of reducing a diameter, suppressing generation of unexpected sounds due to vibration of a linear conductor when a fire is detected and a speaker sounds and coming-off or shifting of the linear conductor due to the sound of the speaker, and improving assemblability during manufacturing.SOLUTION: A smoke sensor 1, which is a fire alarm device, includes a main body base 11 having a peripheral wall 115 and a flange portion 114 therearound and a linear conductor 142 installed at a flange portion 114 along the peripheral wall 115. The main body base 11 has a component accommodating wall 113 protruding from the peripheral wall 115. The component accommodating wall 113 that accommodates a speaker 13 inside has a recess 113b on the flange portion 114 side and a part of the linear conductor 142 is accommodated in the recess 113b.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a fire alarm.

Background Art

[0002] Patent Document 1 describes a wireless fire detector equipped with an antenna. In Patent Document 1, the antenna is arranged along the inside of the main body cover. The antenna is a linear conductor. Patent Document 2 also describes a wireless fire detector. In Patent Document 2, the antenna and the conductor are arranged along the inside of the main body cover. The antenna and the conductor are linear conductors. The fire detector of Patent Document 2 is equipped with a speaker and emits an alarm sound during a fire, and is a kind of fire alarm.

[0003] FIG. 1 shows the inside of a conventional smoke detector as described in Patent Document 2. FIG. 1 is a view from below with the smoke detector 9, which is a fire alarm, installed on the ceiling and with the main body cover at the bottom of the smoke detector 9 and the smoke intake cover inside it removed. When viewed from below, a circuit board 92 and a circular speaker 93 are attached to the main body base 91. The main body base 91 is also provided with a trapezoidal smoke detection part 911 for detecting smoke, a rectangular battery housing part 912 for housing a battery on the back side of the main body base 91 as viewed from the drawing, and a circumferential component housing wall 913 for housing the speaker 93. The circuit board 92 is arranged avoiding the smoke detection part 911, the battery housing part 912, the component housing wall 913, etc. of the main body base 91. Also, a linear conductor 941 and a linear conductor 942 are connected to the circuit board 92. The linear conductor 942 is arranged along the outer circumference of the flange part 914 of the main body base 91 on the surface close to the circuit board 92 and is placed on a plurality of wire placement protrusions 915 protruding from the flange part 914.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a linear conductor is arranged at a position close to the circuit board as in the conventional example, the linear conductor is arranged outside the speaker connected to the circuit board. Therefore, the diameter of the fire alarm becomes large. In addition, there is a possibility that the linear conductor vibrates when the speaker sounds, generating an unexpected sound, and there is a risk that the linear conductor may shift or become detached due to the vibration when the speaker sounds. The present invention solves the above problems.

Means for Solving the Problems

[0006] A fire alarm according to an embodiment of the present invention includes a main body base having a peripheral wall and a flange portion around it, and a linear conductor installed on the flange portion along the peripheral wall, the main body base has a component housing wall protruding from the peripheral wall, and the component housing wall for housing a speaker inside has a recess on the side of the flange portion, and a part of the linear conductor is housed in the recess.

Effects of the Invention

[0007] In the present invention, since the component housing wall protruding from the peripheral wall of the main body base has a recess and the linear conductor is housed in the recess, the diameter of the fire alarm can be reduced. In addition, by housing the linear conductor in the recess, it is possible to suppress the occurrence of an unexpected sound due to the vibration of the linear conductor when the fire is detected and the speaker sounds, and the detachment or displacement of the linear conductor due to the sound of the speaker. Furthermore, by housing the linear conductor in the recess, the position of the linear conductor is easily determined, and the assemblability in manufacturing the fire alarm is improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0009] Smoke detectors etc. are often assembled with the bottom side up when installing on the ceiling. In this embodiment, a smoke detector having an alarm sound generation function, which is an example of a fire alarm, will be described in terms of the vertical direction during assembly. The smoke detector 1 of the embodiment has a wireless interlocking device and interlocks with other smoke detectors. When the smoke detector 1 detects smoke during a fire etc., the smoke detector 1 sounds the speaker and transmits a smoke detection signal to other smoke detectors by wireless transmission to sound the speakers of other smoke detectors. Also, the smoke detector 1 receives a smoke detection signal from other smoke detectors and sounds the speaker.

[0010] Figure 2 is an exploded perspective view of the smoke detector 1 of the embodiment seen from diagonally above during assembly. The main body cover 19, which is in the lowest position when installed on the ceiling, is shown at the top. In Figure 2, the main body base 11, the circuit board 12 to which the linear conductors 141 and 142 are connected, the speaker 13, the smoke intake cover 15, and the main body cover 19 are shown in order from the bottom. In Figure 2, the linear conductor 141 is located above the circuit board 12, and the linear conductor 142 is located below the circuit board 12.

[0011] On the main body base 11 shown at the bottom of FIG. 2, a smoke detection unit 111, a battery housing unit 112, and a component housing wall 113 are provided. The smoke detection unit 111 is a place where external smoke is taken in and irradiated with light, and scattered light here is detected to sense smoke. The light emitting element and the light receiving element for detecting the scattered light face an opening provided in the wall of the smoke detection unit 111 and are attached below the circuit board 12. Also, the battery housing unit 112 houses a battery (not shown) on the back side of the main body base 11 in FIG. 2. Further, a switch base 116 protrudes upward from the main body base 11. Near the smoke detection unit 111, a female screw cylinder 117 is provided.

[0012] A peripheral wall 115 is provided in a substantially cylindrical shape around the main body base 11, and a flange portion 114 extends laterally on the outside of the peripheral wall 115. In the flange portion 114, a plurality of columnar protrusions 114a protrude upward with a gap from the peripheral wall 115. Also, a plurality of locking pieces 115a with tapered surfaces facing upward protrude outward from the peripheral wall 115. The peripheral wall 115 has a shape in which the cylinder is partially cut. And near the battery housing unit 112, the peripheral wall 115 is cut to form a wall cutout portion 115b. The flange portion 114 is not provided over the entire circumference, and in the vicinity of the place where the locking piece 115a protrudes outward on the outside of the peripheral wall 115, it has a shape in which an annular plate is partially cut.

[0013] Even outside the wall cutout portion 115b, in the portion of the component housing wall 113, the peripheral wall 115 is not formed. The component housing wall 113 is formed in a substantially cylindrical shape, and a part of it protrudes outward from the nearby peripheral wall 115 to form a protruding portion 113a. Also, a recess 113b for housing the linear conductor 142 is provided below the protruding portion 113a. The flange portion 114 is also cut outside the protruding portion 113a where the component housing wall 113 protrudes and is not formed outside the protruding portion 113a.

[0014] The circuit board 12 shown second from the bottom in FIG. 2 is placed on the main body base 11. In the placed state, the linear conductor 142 located on the lower side of the circuit board 12 passes through the side surface in the short direction of the battery housing portion 112, then through the wall notch portion 115b, bends to the opposite side of the battery housing portion 112, and then extends in an arc along the outer edge of the peripheral wall 115. Then, it passes through the concave portion 113b located below the protruding portion 113a of the component housing wall 113 protruding outward from the peripheral wall 115, and again reaches the vicinity outside the smoke detector 111 along the outer edge of the peripheral wall 115. The arc-shaped portion of the linear conductor 142 is placed on the flange portion 114 and passes through the outside of the peripheral wall 115, inside the protrusion 114a, and inside the concave portion 113b.

[0015] In the smoke detector 1 of the embodiment, a CO sensor 122 and a switch 123 are attached to the circuit board 12. Further, the circuit board 12 is provided with a screw through hole 124 through which a male screw passes when the smoke intake cover 15 is screwed to the main body base 11.

[0016] The linear conductor 141 functions as an antenna. Also, the linear conductor 142 is electrically connected to the ground of the circuit board 12. When the smoke detector 1 performs transmission and reception by wireless communication, the high-frequency potential fluctuation of the linear conductor 141, which is an antenna, with respect to the ground is used. And because the linear conductor 142 is connected to the ground, the area of the ground becomes wider, sufficient transmission radio waves are generated, and the reception sensitivity is increased. Also, when the smoke detector 1 is attached to a ceiling or the like, the linear conductor 141 is at a position away from the ceiling or the like, so in this regard as well, sufficient transmission radio waves are generated and the reception sensitivity is increased. Furthermore, since the linear conductor 141 is arranged at a lateral position opposite to the speaker 13 on the circumference of the smoke detector 1, it is difficult for the sound of the speaker 13 to be transmitted and vibration is less likely to occur. Also, since the linear conductor 142 is housed in the concave portion 113b and vibration is suppressed, it is difficult for the linear conductor 141 to generate vibrations that resonate with the linear conductor 142. Note that although the linear conductor 142 is connected to the ground, it contributes to the transmission and reception of wireless communication and can be said to be a kind of antenna.

[0017] When a fire is detected, the speaker 13 that sounds is housed inside the component housing wall 113 of the main body base 11 with the sounding direction facing upward. The speaker 13 has two connection lines 131. After arranging the circuit board 12 on the main body base 11, the speaker 13 is installed on the component housing wall 113, and the connection lines 131 of the speaker 13 are soldered and connected to the connection terminals 121 of the circuit board 12 for attachment.

[0018] The smoke intake cover 15 described second from the top in FIG. 2 has an insect screen 17 covered and attached by an optical bench cover 18. A plurality of ridges 151 are arranged toward the insect screen 17, and outside air is introduced into the smoke detection unit 111 through the insect screen 17. Also, a light-transmitting switch cover 16 is arranged on the upper part of the smoke intake cover 15. The light-transmitting switch cover 16 is pivotally supported by a switch base 116 of the main body base 11 and installed so as to contact a switch 123 provided on the circuit board 12. The light-transmitting switch cover 16 rotates with the switch base 116 as a fulcrum when pushed, and the switch 123 is pushed. In FIG. 2, a part is hidden by the ridge 151, but screw passing holes 153 are provided near the insect screen 17. Also, a plurality of locking springs 152 are provided around the smoke intake cover 15. The locking springs 152 engage with locking pieces 115a of the main body base 11 to fix the smoke intake cover 15 to the main body base 11. Further, the smoke intake cover 15 is fixed to the main body base 11 by a male screw (not shown) screwed into a female screw cylinder 117 of the main body base 11 through the screw passing holes 153 of the smoke intake cover 15 and the screw passing holes 124 of the circuit board 12.

[0019] The main body cover 19 that becomes the lowermost part when the smoke sensor 1 is installed on the ceiling covers the main body base 11, the circuit board 12, the smoke intake cover 15, etc. The main body cover 19 is fixed by a male screw (not shown) inserted from the lower side of the main body base 11 in FIG. 2. The main body cover 19 is provided with ventilation holes 191 around it, and outside air is taken in from the ventilation holes 191 between a plurality of ridges 151 in the smoke intake cover 15.

[0020] FIG. 3 shows an enlarged view of the vicinity of the protruding portion 113a on the component housing wall 113 of the main body base 11 of the smoke detector 1 as viewed obliquely downward. FIG. 4 shows an enlarged view of the vicinity of the protruding portion 113a of the main body base 11 as further enlarged and viewed obliquely upward. A flange portion 114 protrudes in the circumferential direction from below the peripheral wall 115. Also, a component housing wall 113 protrudes in the circumferential direction from the peripheral wall 115 to form the protruding portion 113a. Below the protruding portion 113a is a concave portion 113b. A linear conductor 142 is sandwiched between the protrusion 114a and the concave portion 113b. The linear conductor 142 is accommodated between the housing wall lower surface 113c, which is the lower surface of the protruding portion 113a of the component housing wall 113, and the flange upper surface 114b, which is the upper surface of the flange portion 114. The linear conductor 142 is blocked and positioned with its inner side by the outer surface of the peripheral wall 115, its outer side by the inner side of the protrusion 114a, its upper side by the housing wall lower surface 113c, and its lower side by the flange upper surface 114b.

[0021] Therefore, the accommodation width d shown in FIGS. 3 and 4, which is the width between the housing wall lower surface 113c and the flange upper surface 114b, is equal to or greater than the diameter φ of the linear conductor 142. However, if the accommodation width d is too large, the linear conductor 142 will not be stable in the concave portion 113b. The relationship between the accommodation width d shown in FIGS. 3 and 4 and the diameter φ of the linear conductor 142 is φ≦d≦1.5φ is preferably satisfied. In the embodiment, the cross-section of the linear conductor 142 is circular. However, when the cross-section of the linear conductor 142 is a shape other than circular, such as rectangular or elliptical, the relationship between the accommodation width d and the vertical height Lh of the linear conductor 142 is Lh≦d≦1.5Lh is preferably satisfied.

[0022] On the upper surface of the flange portion 114, a plurality of protrusions 114a are provided. As shown in FIGS. 3 and 4, the flange portion 114 has protrusions 114a on both sides of the recess 113b along the periphery, and the linear conductor 142 is substantially fixed by the protrusions 114a and the recess 113b. On both sides of the recess 113b, the linear conductor 142 is sandwiched between the side surface of the peripheral wall 115 of the protrusion 114a, the upper surface 114b of the flange, and the outer surface of the peripheral wall 115. In the recess 113b, the linear conductor 142 is pressed upward by the lower surface 113c of the housing wall and is substantially fixed.

[0023] The protrusion 114a shown in FIGS. 3 and 4 has a distance w from the outer surface of the peripheral wall 115. The distance w also needs to be equal to or greater than the diameter φ of the linear conductor 142, but if it is too large, the linear conductor 142 will not be stable. The relationship between the distance w and the diameter φ of the linear conductor 142 is φ≦w≦1.5φ is preferably. In addition, when the cross-section of the linear conductor 142 is a shape other than circular, such as rectangular or elliptical, the relationship between the distance w and the lateral width Lw of the linear conductor 142 is Lw≦w≦1.5Lw is preferably.

[0024] Also, the protrusion 114a shown in FIGS. 3 and 4 has a height h from the upper surface 114b of the flange. If the height h is at least half of the diameter φ, the linear conductor 142 with a circular cross-section is not easily detached when placed on the upper surface 114b of the flange. Also, if the height h is too large, it is difficult to accommodate the linear conductor 142 in the recess 113b during assembly. The relationship between the height h and the diameter φ of the linear conductor 142 is 0.5φ≦h≦φ is preferably. In addition, when the cross-section of the linear conductor 142 is a shape other than circular, such as rectangular or elliptical, the relationship between the height h and the vertical height Lh of the linear conductor 142 is 0.5Lh≦h≦Lh is preferably.

[0025] As shown in FIGS. 2 to 4, on the outer side of the upper part of the peripheral wall 115 in the main body base 11, locking pieces 115a having an upwardly tapered surface are provided. A plurality of locking pieces 115a project outward from the peripheral wall 115 and lock the locking spring 152 of the smoke intake cover 15 to lock the smoke intake cover 15 to the main body base 11. The locking spring 152 is formed in a frame shape, and the locking piece 115a enters the frame and the lower surface of the locking piece 115a is hung on the frame and locked. Since the locking piece 115a has a tapered surface, when the linear conductor 142 is covered from above and moved to the upper surface of the flange 114b during the assembly of the smoke detector 1, the locking piece 115a temporarily pushes the linear conductor 142 outward, so it does not become an obstacle to assembly. Together with the linear conductor 141, the linear conductor 142 is formed of a metal wire having a certain degree of elasticity.

[0026] FIG. 5 shows a top view of the concave portion 113b with the linear conductor 142 accommodated therein. FIG. 5 is an enlarged view of the vicinity of the component housing wall 113 in a situation where the circuit board 12 connected to the linear conductor 142 is installed on the main body base 11. The linear conductor 142 is sandwiched between the outer surface of the peripheral wall 115 and the protrusion 114a provided on the flange portion 114. Further, a part of the linear conductor 142 placed on the upper surface of the flange 114b is located below the protruding portion 113a of the component housing wall 113, and in FIG. 5 viewed from above, the portion located below is hidden. Also, the linear conductor 142 is located below the locking piece 115a, but during assembly, the locking piece 115a having a tapered surface temporarily pushes the linear conductor 142 outward, so it does not become an obstacle.

[0027] Furthermore, as shown in FIG. 3, the lower surface of the locking piece 115a is at a position higher than the lower surface of the housing wall 113c. Therefore, when removing the linear conductor 142 from the concave portion 113b, the linear conductor 142 can be expanded and temporarily moved from the concave portion 113b to the lower surface of the locking piece 115a and the lower surface of the housing wall 113c. Then, if the linear conductor 142 is further expanded to overcome the locking piece 115a, the linear conductor 142 is removed. Since it is not necessary to overcome the concave portion 113b and the locking piece 115a at the same time during removal, the removal can be easily performed.

[0028] As shown in FIG. 5, inside the protruding portion 113a of the component housing wall 113, a stepped portion 113d protrudes upward. Due to the presence of the stepped portion 113d inside the component housing wall 113, even though there is a depression due to the outer concave portion 113b, the lower part of the protruding portion 113a does not become thin. And since the stepped portion 113d makes the component housing wall 113 have a strong structure, even when the speaker 13 sounds at a high volume, vibration is less likely to occur in the component housing wall 113. Since the speaker 13 has a structure with a narrowed lower part, even with the stepped portion 113d, it does not become an obstacle when the speaker 13 is housed and installed in the component housing wall 113.

[0029] Next, the process of assembling the smoke detector 1 will be described. As shown in FIG. 2, linear conductors 141 and 142 are connected to the circuit board 12. Then, the circuit board 12 is fitted into the main body base 11. At this time, with the contact point of the circuit board 12 as the base end, the linear conductor 142 extends outward along the short side surface of the battery housing portion 112, bends through the wall notch portion 115b, and goes to the opposite side of the battery housing portion 112 outside the peripheral wall 115. And the linear conductor 142 extends in an arc shape along the outside of the peripheral wall 115. When attaching the linear conductor 142 to the main body base 11, when the linear conductor 142 is pushed downward toward the main body base 11 side, the arc-shaped portion of the linear conductor 142 expands and gets over the locking piece 115a of the peripheral wall 115. And the arc-shaped portion that returns to its original shape by elasticity contacts the outer surface of the peripheral wall 115 inside the protrusion 114a. Further, when the operator presses down the linear conductor 142 with a finger outside the component housing wall 113, the linear conductor 142 is housed in the lower concave portion 113b of the component housing wall 113 and contacts the flange upper surface 114b. Since the linear conductor 142 has a certain degree of elasticity, when it is housed in the concave portion 113b, the linear conductor 142 and the circuit board 12 are in a semi-fixed state.

[0030] Next, place the speaker 13 inside the component storage wall 113, and solder the connection wire 131 to the connection terminal 121 of the circuit board 12 shown in FIG. 5. At this time, the linear conductor 142 is in a semi-fixed state due to the recess 113b of the component storage wall 113. Therefore, the circuit board 12 connected by the linear conductor 142 does not move much even without being screwed, and the soldering operation can be efficiently performed. In this way, the presence of the recess 113b makes it possible to improve the assemblability.

[0031] FIG. 6 shows a top view of the state where the soldering of the speaker 13 is completed. The linear conductor 142 has the connection point 125 of the circuit board 12 as its base end. Then, it extends linearly outward on the side surface of the battery storage portion 112, bends outward through the wall notch portion 115b, and bends to the opposite side of the battery storage portion 112 outside the peripheral wall 115. Then, it extends in an arc shape along the outer surface of the peripheral wall 115. In FIG. 6, from the arc end 142a to the tip 142t is an arc, forming an arc portion. And the center m of the protrusion 113a and the recess 113b is located slightly on the tip 142t side from the center of the arc portion. The center m of the protrusion 113a and the recess 113b is preferably located in the range from the center, which is the 1 / 2 position from the arc end 142a to the tip 142t side in the arc portion formed by the linear conductor 142, to the 1 / 4 position from the center to the tip 142t side. By setting such a position, the linear conductor 142 can be efficiently fixed so that it is difficult to move. Also, when the speaker 13 sounds, the vibration on the tip 142t side of the linear conductor 142 is also efficiently suppressed.

[0032] During assembly, place the smoke intake cover 15 shown in FIG. 2 on top of the state shown in FIG. 6. At this time, the linear conductor 141 is led out from the notch 154 of the smoke intake cover 15 shown in FIG. 2 to the upper side of the smoke intake cover 15 and arranged. Then, insert a male screw into the screw through-hole 153 of the smoke intake cover 15 and screw it into the female screw cylinder 117 of the main body base 11 through the screw through-hole 124 of the circuit board 12. Thereby, the smoke intake cover 15 is fixed to the main body base 11 with the circuit board 12 sandwiched therebetween. Also, a translucent switch cover 16 is placed on the switch base 116 and the switch 123 that protrude above the smoke intake cover 15. Then, cover and fix the main body cover 19, and the smoke detector 1 is assembled.

[0033] The smoke detector 1 of this embodiment has not only a smoke sensing sensor but also a CO sensor 122. Therefore, the number of circuits to be mounted increases and the area of the circuit board 12 becomes larger. Also, since it is necessary to increase the battery capacity due to multifunctionalization, the battery housing portion 112 is also large. Even in such a smoke detector 1 which is a fire alarm, an increase in diameter can be suppressed.

[0034] In the embodiment, as shown in FIGS. 2 to 4, the flange portion 114 is not provided below the protruding portion 113a, but a flange portion may be provided through a gap that becomes a recess below the protruding portion. However, if there is a flange portion, the finger of the operator who pushes the linear conductor during assembly catches on the flange portion, making it difficult to push the linear conductor into the recess. It is easier to push the linear conductor into the recess when there is no flange portion below the protruding portion. In the embodiment, the lower surface of the locking piece 115a is at a position higher than the lower surface of the housing wall 113c. However, they may be at the same height.

[0035] Further, in the embodiment, the recess 113b is recessed from the outer surface of the peripheral wall 115 and has the same outer surface that continues to the lower peripheral wall 118 at the lower part with a smaller radius of the outer surface than the peripheral wall 115. Thereby, a gap is formed between the lower peripheral wall 118 and the linear conductor 142, and it is easy to expand with a finger or the like when removing the linear conductor 142. However, the recess 113b may have the same outer surface continuous from the peripheral wall 115. Also, the outer surface of the peripheral wall 115 and the outer surface of the lower peripheral wall 118 may be continuous cylindrical outer surfaces with the same radius.

[0036] The component housing wall may house components other than the speaker. However, when housing the speaker, it is possible to suppress the occurrence of unexpected sounds due to the vibration of the linear conductor caused by the sounding of the speaker, and the disconnection or displacement of the linear conductor due to the sounding of the speaker. Also, due to the narrowed shape at the rear of the speaker, even if a stepped portion is provided at the end inside the component housing wall, it does not contact the speaker. And the stepped portion can prevent the wall of the recess from becoming thin.

[0037] In the embodiment, the smoke detector is described as an example of the fire alarm, but the present invention can also be used in a wireless fire alarm without a fire detection function. Even in such a fire alarm, when arranging the battery housing part and the component housing wall of the sounding device side by side, the linear conductor is housed in the recess. Also, as a fire alarm having the function of a fire detector, it can also be used in other fire detectors such as a heat detector. Further, the fire detector in the embodiment has a plurality of functions such as a CO sensor and a smoke detection sensor. However, even when giving the function of a fire alarm to a fire detector that does not have a plurality of functions, it can be miniaturized by reducing the diameter using the present embodiment.

[0038] In addition, the specific configuration is not limited to the embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. Also, the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

Description of Symbols

[0039] 1 Smoke detector, 11 Body base, 111 Smoke detection part, 112 Battery housing part, 113 Component housing wall, 113a Protrusion, 113b Recess, 113c Lower surface of the housing wall, 113d Step part, 114 Flange part, 114a Protrusion, 114b Upper surface of the flange, 115 Peripheral wall, 115a Locking piece, 115b Wall notch part, 116 Switch base, 117 Female screw cylinder, 118 Lower peripheral wall 12 Circuit board, 121 Connection terminal, 122 CO sensor, 123 Switch, 124 Screw through hole, 125 Connection point 13 Speaker, 131 Connection wire 141 Linear conductor, 142 Linear conductor, 142a Arc end, 142t Tip 15 Smoke intake cover, 151 Ridge, 152 Locking spring, 153 Screw through hole, 154 Notch 16 Translucent switch cover, 17 Insect screen, 18 Optical bench cover 19 Body cover, 191 Vent hole d Accommodation width, w Distance, h Height, φ Diameter, m Center 9 Smoke detector, 91 Body base, 911 Smoke detection part, 912 Battery housing part, 913 Component housing wall, 914 Flange part, 915 Wire placement protrusion 92 Circuit board, 93 Speaker 941 Linear conductor, 942 Linear conductor

Claims

1. A main body base having a peripheral wall and a flange portion around it, and a linear conductor installed on the flange portion along the peripheral wall, characterized in that: the main body base has a component housing wall protruding from the peripheral wall, the component housing wall for housing a speaker inside has a recess on the side of the flange portion, a part of the linear conductor is housed in the recess, and the fire alarm is characterized by this.

2. The fire alarm according to claim 1, characterized in that the flange portion has protrusions on both sides of the recess, and the linear conductor is clamped between the protrusions and the recess.

3. The fire alarm according to claim 1, characterized in that the center of the recess is located in the range from the center of the arc portion formed by the linear conductor to a position of 1 / 4 toward the tip side from the center.

4. A plurality of locking pieces having tapered surfaces protrude outward from the peripheral wall, and the smoke intake cover is locked by the locking pieces, and the fire alarm according to claim 1 is characterized by this.

5. The fire alarm according to any one of claims 1 to 4, characterized in that it has a function of a fire sensor.

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